STUDENT NO 21123303
33 39 49 33 70 40.9
Thursday, November 3, 2011
immunology course marks 2011
student TEST1 TEST2 PRAC1 PRAC2 Project CM
21110644 54 66 85 70 70 66.25
21001585 58 33 81 47 70 53.5
21001710 50 78 89 90 100 75.25
21141071 59 70 70 80 90 70.2
21008595 77 95 53 82 70 78.85
21108605 55 51 75 47 70 57.1
21008167 55 14 55 83 0 41.4
21014104 42 51 70 85 70 58.15
21014093 55 68 98 88 70 71.8
21001465 50 81 75 77 100 72.1
21113096 19 18 73 20 50 30.05
21103142 42 60 74 73 70 59.65
21123354 38 51 53 68 70 51.85
20908733 43 53 65 60 60 53.55
21107438 50 73 90 93 80 72.35
21141069 41 55 68 63 70 55.45
21120190 50 48 60 47 70 52.45
21014095 63 62 85 87 90 72.3
21014107 71 97 93 93 100 88.3
21004440 69 74 75 70 100 74.65
21009732 54 54 63 63 70 58.3
21014109 56 59 78 78 70 64.9
21005818 70 63 83 80 70 71.35
20902745 36 71 78 80 70 62.8
21108356 60 52 85 90 70 66.85
20906847 58 57 98 77 60 66.75
21130079 40 16 41 43 50 34.4
20936113 70 64 84 93 100 76.75
21109005 22 76 83 60 70 57.85
20905697 34 53 83 55 60 52.8
21123303 33 39 49 33 0 33.9
20907389 39 47 73 60 60 51.75
21111318 57 60 53 63 70 59.5
20900883 52 58 73 70 90 63.45
21013928 74 68 80 95 90 77.85
21103921 49 66 71 47 70 59.2
21017854 57 57 76 63 70 62.05
20907165 21 36 73 37 50 38.6
21014097 55 61 98 53 70 64.45
20903040 50 65 89 50 70 62.35
21008877 52 41 75 83 80 59.6
21104720 51 46 76 73 80 59.45
20900920 35 62 34 8 0 35.4
20920886 47 64 83 53 60 59.7
21110353 31 47 73 67 70 51.4
21139224 49 68 65 43 100 61.3
20924296 40 48 43 70 60 49.35
21011387 51 83 65 67 70 67
21000961 43 41 64 73 70 52.75
21030811 42 61 70 53 70 56.35
21110644 54 66 85 70 70 66.25
21001585 58 33 81 47 70 53.5
21001710 50 78 89 90 100 75.25
21141071 59 70 70 80 90 70.2
21008595 77 95 53 82 70 78.85
21108605 55 51 75 47 70 57.1
21008167 55 14 55 83 0 41.4
21014104 42 51 70 85 70 58.15
21014093 55 68 98 88 70 71.8
21001465 50 81 75 77 100 72.1
21113096 19 18 73 20 50 30.05
21103142 42 60 74 73 70 59.65
21123354 38 51 53 68 70 51.85
20908733 43 53 65 60 60 53.55
21107438 50 73 90 93 80 72.35
21141069 41 55 68 63 70 55.45
21120190 50 48 60 47 70 52.45
21014095 63 62 85 87 90 72.3
21014107 71 97 93 93 100 88.3
21004440 69 74 75 70 100 74.65
21009732 54 54 63 63 70 58.3
21014109 56 59 78 78 70 64.9
21005818 70 63 83 80 70 71.35
20902745 36 71 78 80 70 62.8
21108356 60 52 85 90 70 66.85
20906847 58 57 98 77 60 66.75
21130079 40 16 41 43 50 34.4
20936113 70 64 84 93 100 76.75
21109005 22 76 83 60 70 57.85
20905697 34 53 83 55 60 52.8
21123303 33 39 49 33 0 33.9
20907389 39 47 73 60 60 51.75
21111318 57 60 53 63 70 59.5
20900883 52 58 73 70 90 63.45
21013928 74 68 80 95 90 77.85
21103921 49 66 71 47 70 59.2
21017854 57 57 76 63 70 62.05
20907165 21 36 73 37 50 38.6
21014097 55 61 98 53 70 64.45
20903040 50 65 89 50 70 62.35
21008877 52 41 75 83 80 59.6
21104720 51 46 76 73 80 59.45
20900920 35 62 34 8 0 35.4
20920886 47 64 83 53 60 59.7
21110353 31 47 73 67 70 51.4
21139224 49 68 65 43 100 61.3
20924296 40 48 43 70 60 49.35
21011387 51 83 65 67 70 67
21000961 43 41 64 73 70 52.75
21030811 42 61 70 53 70 56.35
Wednesday, October 26, 2011
Monday, October 24, 2011
Wednesday, October 19, 2011
Functions of HLA antigens
Both MHC class I and II are involved in MHC restriction.
Both MHC class I and II are antigens targeted by the immune response in transplant rejection.
Some terms before we proceed:
Graft rejection refers to the recipients immune response rejecting the donor organ.
GVHD (graft versus host disease) refers to the transplanted organ mounting an immune response to the host's antigens. Sounds strange but GVHD is potentially fatal. That is why identification of Ag and Ab in both the recipient and donor is important.
HLA-A, HLA-B and HLA-DR are the main antigens targeted by the recipient, in graft rejection. If there are incompatibilities with these antigens, the feasibility of a successful transplant is low.
All MHC class II antigens are targets in GVHD.
Histocompatibility testing ideally should identify incompatibilities for both class I and class II. This will reduce the likelihood of both graft rejection and GVHD.
Both MHC class I and II are antigens targeted by the immune response in transplant rejection.
Some terms before we proceed:
Graft rejection refers to the recipients immune response rejecting the donor organ.
GVHD (graft versus host disease) refers to the transplanted organ mounting an immune response to the host's antigens. Sounds strange but GVHD is potentially fatal. That is why identification of Ag and Ab in both the recipient and donor is important.
HLA-A, HLA-B and HLA-DR are the main antigens targeted by the recipient, in graft rejection. If there are incompatibilities with these antigens, the feasibility of a successful transplant is low.
All MHC class II antigens are targets in GVHD.
Histocompatibility testing ideally should identify incompatibilities for both class I and class II. This will reduce the likelihood of both graft rejection and GVHD.
HLA and MHC
MHC is located on the short arm of chromosome 6. This locus codes for the HLA antigens that are found on various cells in the body. There are 3 classes of MHC.
MHC class I are found on platelets and all nucleated cells. examples of MHC class I are HLA-A, HLA-B and HLA-C.
MHC class II are found on macrophages, monocytes and lymphocytes. Examples are HLA-D, HLA-DP, HLA-DQ and HLA-DR.
Examples of MHC class III are C2, C4 and Factor B. (remember complement?)
We need to know the actual structures of MHC class I and II.
For each structure you need to know where antigen binds, and where CD4 or CD8 interacts. Remember that CD4 or CD8 are cell markers and are attached to cells, viz. TH and TC respectively. So do not draw just the cell marker; ensure that you draw the cell as well.
You need to know the names of each domain; these are not interchangeable and you will lose marks if they are labelled incorrectly.
Ag binds between alpha 1 and alpha 2, and CD8 interacts with alpha 3. (MHC class I)
Ag binds between alpha 1 and beta 1, and CD4 interacts with beta 2 (MHC class II)
MHC class I are found on platelets and all nucleated cells. examples of MHC class I are HLA-A, HLA-B and HLA-C.
MHC class II are found on macrophages, monocytes and lymphocytes. Examples are HLA-D, HLA-DP, HLA-DQ and HLA-DR.
Examples of MHC class III are C2, C4 and Factor B. (remember complement?)
We need to know the actual structures of MHC class I and II.
For each structure you need to know where antigen binds, and where CD4 or CD8 interacts. Remember that CD4 or CD8 are cell markers and are attached to cells, viz. TH and TC respectively. So do not draw just the cell marker; ensure that you draw the cell as well.
You need to know the names of each domain; these are not interchangeable and you will lose marks if they are labelled incorrectly.
Ag binds between alpha 1 and alpha 2, and CD8 interacts with alpha 3. (MHC class I)
Ag binds between alpha 1 and beta 1, and CD4 interacts with beta 2 (MHC class II)
Tuesday, October 18, 2011
TERMS in Ag Ab reactions
Titre refers to the concentration of a particular substance in a test tube.It is expressed by inverting the concentration of that substance. If the concentration of glucose is 1/16 in test tube no 4, the titre of test tube no 4 is 16.
A serial dilution is any dilution where the concentration decreases by the same quantity in each successive step.
double dilutions are a series of ½ dilutions. Each successive tube will ½ the amount of the original concentrated solution.
In any serological test done in the lab, we are looking for an unknown using a known. The known are the reagents that we use, usually commercialy available. The unknown is usually in the patients specimen, and can be either antigen or antibody.
Acute phase serum refers to specimen taken during the disease state, used to diagnose the disease.
Convalescent phase serum is taken after the disease has been treated, and can be used to determine if titre has decreased due to effective treatment.
Serum has no clotting factors present; usually specimen taken in brown top blood collection tube (with no anticoagulants)
Plasma has all clotting factors present; usually collected in purple top tube (containing anticoagulants)
Sterility is not an issue in serology as we are looking for presence of Ag or Ab. Any organisms present will not affect the results
Sensitivity refers to the ability of a serologicl test to identify the Ag or Ab in minute amounts. There will not be any false negative results due to the Ag or Ab being present in very small amounts.
Specificity refers to the ability of a serological test to identify the exact Ag or Ab being tested for. There are no cross reactions giving false positive results.
All serological tests have to be controlled. These controls are put up at the same time as the tests, and must give the correct expected readings/results before the test results can be taken as being accurate.Both positive and negative controls are used.
There is increasing automation in serology. Even in tests that are not automated, the equipment used are designed to save time and space. Microtitre plates replace test tubes. Slides with either Ag or Ab absorbed onto their wells save time in processing.Most procedures use very small amounts of substances/reagents. This saves money as reagents are usually very expensive.
Due to the precise and small amounts of reagents used in serological tests, serology requires the lab worker to be accurate and precise in their work. Amounts are not negotiable. any deviation from this will lead to inaccurate results.
A serial dilution is any dilution where the concentration decreases by the same quantity in each successive step.
double dilutions are a series of ½ dilutions. Each successive tube will ½ the amount of the original concentrated solution.
In any serological test done in the lab, we are looking for an unknown using a known. The known are the reagents that we use, usually commercialy available. The unknown is usually in the patients specimen, and can be either antigen or antibody.
Acute phase serum refers to specimen taken during the disease state, used to diagnose the disease.
Convalescent phase serum is taken after the disease has been treated, and can be used to determine if titre has decreased due to effective treatment.
Serum has no clotting factors present; usually specimen taken in brown top blood collection tube (with no anticoagulants)
Plasma has all clotting factors present; usually collected in purple top tube (containing anticoagulants)
Sterility is not an issue in serology as we are looking for presence of Ag or Ab. Any organisms present will not affect the results
Sensitivity refers to the ability of a serologicl test to identify the Ag or Ab in minute amounts. There will not be any false negative results due to the Ag or Ab being present in very small amounts.
Specificity refers to the ability of a serological test to identify the exact Ag or Ab being tested for. There are no cross reactions giving false positive results.
All serological tests have to be controlled. These controls are put up at the same time as the tests, and must give the correct expected readings/results before the test results can be taken as being accurate.Both positive and negative controls are used.
There is increasing automation in serology. Even in tests that are not automated, the equipment used are designed to save time and space. Microtitre plates replace test tubes. Slides with either Ag or Ab absorbed onto their wells save time in processing.Most procedures use very small amounts of substances/reagents. This saves money as reagents are usually very expensive.
Due to the precise and small amounts of reagents used in serological tests, serology requires the lab worker to be accurate and precise in their work. Amounts are not negotiable. any deviation from this will lead to inaccurate results.
co receptors in cell to cell interactions
We have learnt that TH cells express CD4 which interacts with MHC class II expressed by APC's.
There are other co receptors involved in the above interaction.
TH cell -------------- APC
LFA-2 LFA-3
LFA-1 ICAM-1
CD28 B7
TCR+CD4 MHC class II + peptide
The most important interaction is between CD28 and B7
There are other co receptors involved in the above interaction.
TH cell -------------- APC
LFA-2 LFA-3
LFA-1 ICAM-1
CD28 B7
TCR+CD4 MHC class II + peptide
The most important interaction is between CD28 and B7
HIV infection
2 types: HIV-1 and HIV-2.
HIV-1 is more prevalent and largely responsible for the AIDS pandemic
HIV infection takes place or refers to when a person acquires the HIV virus. The initial illnes (which does not appear in all people) is a ild glandular fever like infection. There is a huge rise in virus levels.
The host's immune response controls the infection and there follows an asymptomatic period. This can last for 8-10 years depending on the host's immune status.The virus continues to multiply during this period.The antigenic makeup of the virus changes as the infection proceeds, which hampers the host's immune response to eradicate the infection.
The HIV virus requires both CD4 and either CXCR5 or CCR5 as co receptors for entry into the host's cells. During the asymptomatic period, the co receptor preference changes from CCR5 to CXCR4.
The level of CD4 cells decreases until AIDS develops. AIDS is characterized by infections with opportunistic organisms.
HIV-1 infections have a shorter asymptomatic period, a quicker progression of disease and higher rates of transmission when compared to HIV-2
Most HIV-1 strains use CCR5 as a co receptor and are known as R5 strains. HIV-1 strains that use CXCR4 as a co receptor are known as X4 strains.
There are some individuals who have had repeated exposure to HIV and not become infected. Their CCR5 genes have mutated. People with homozygous mutations express no CCR5 on their cells and are highly resistant to infection. People with heterozygous mutations have increased resistance to HIV.
HIV-1 is more prevalent and largely responsible for the AIDS pandemic
HIV infection takes place or refers to when a person acquires the HIV virus. The initial illnes (which does not appear in all people) is a ild glandular fever like infection. There is a huge rise in virus levels.
The host's immune response controls the infection and there follows an asymptomatic period. This can last for 8-10 years depending on the host's immune status.The virus continues to multiply during this period.The antigenic makeup of the virus changes as the infection proceeds, which hampers the host's immune response to eradicate the infection.
The HIV virus requires both CD4 and either CXCR5 or CCR5 as co receptors for entry into the host's cells. During the asymptomatic period, the co receptor preference changes from CCR5 to CXCR4.
The level of CD4 cells decreases until AIDS develops. AIDS is characterized by infections with opportunistic organisms.
HIV-1 infections have a shorter asymptomatic period, a quicker progression of disease and higher rates of transmission when compared to HIV-2
Most HIV-1 strains use CCR5 as a co receptor and are known as R5 strains. HIV-1 strains that use CXCR4 as a co receptor are known as X4 strains.
There are some individuals who have had repeated exposure to HIV and not become infected. Their CCR5 genes have mutated. People with homozygous mutations express no CCR5 on their cells and are highly resistant to infection. People with heterozygous mutations have increased resistance to HIV.
Thursday, August 11, 2011
overview after lecture one
Hi guys
So I probably left you reeling after such a long lecture; strange terms and a totally different language. Lots to learn and so much expected of you. I hope that everyone stays the duration of the ride, and if anyone is feeling left out or insecure, that they let me know. I can do something. There is always hope, never fear.
Some things i did not tell you. I expect you to re read all that was covered during lectures. I expect you to have a working knowledge at the following lecture of all that was discussed in the previous lecture. Don't know is not an acceptable answer for any question. At least try an answer, any answer. My door is always open for any student who wants to discuss anything. I am being paid to teach you. Make use of me.
Read read and read. Convert statements to drawings and convert drawings to statements. Teach your neighbour or uncle or dog about what you have learnt. If you can teach someone else, then you really know your stuff. This is also good practice for your project.
Enough for now. Exciting stuff awaits. Are you ready???????
So I probably left you reeling after such a long lecture; strange terms and a totally different language. Lots to learn and so much expected of you. I hope that everyone stays the duration of the ride, and if anyone is feeling left out or insecure, that they let me know. I can do something. There is always hope, never fear.
Some things i did not tell you. I expect you to re read all that was covered during lectures. I expect you to have a working knowledge at the following lecture of all that was discussed in the previous lecture. Don't know is not an acceptable answer for any question. At least try an answer, any answer. My door is always open for any student who wants to discuss anything. I am being paid to teach you. Make use of me.
Read read and read. Convert statements to drawings and convert drawings to statements. Teach your neighbour or uncle or dog about what you have learnt. If you can teach someone else, then you really know your stuff. This is also good practice for your project.
Enough for now. Exciting stuff awaits. Are you ready???????
Thursday, August 4, 2011
Something to think about
If you meet a very anxious mom of a young child at the local clinic and, on asking as what the medical problem of her child is, you get told: "She has a temperature", describe clearly what is wrong in that statement.
Sent via my BlackBerry from Vodacom - let your email find you!
Sent via my BlackBerry from Vodacom - let your email find you!
"This e-mail is subject to our Disclaimer, to view click http://www.dut.ac.za"
immunology project 2011
Hi guys
I thought that I should give you a preview of what you will be expected to do in your immunology project this semester. I had another project in mind but due to the lost lecture time, I have had to make changes.
So I hope that all of you are familiar with youtube and have at least watched one video on the site. I also hope that you have access to a cellphone that has video recording capabilities. So you will video yourself describing a concept or procedure relevant to immunology and upload it to YouTube. I will download the video and after watching it, assess it using a rubric that you will be given shortly. So I guess you have to start sharpening your speaking skills and start doing some research. More details about the project will be provided once I see you. Good luck guys!
"This e-mail is subject to our Disclaimer, to view click http://www.dut.ac.za"
the specific immune response
characteristics of the specific immune response
1. specificity
IR is specific for specific Ag or specific component of Ag; epitopes/determinants = portion of Ag recognized by lymphocytes
2. memory
IS remembers Ag; therefore the second response = quicker, more intense
3. self regulation
feedback regulation of IR; normal IR wanes/decreases after time, return to dormant state
4. diversity
lymphocytes can respond to a very large number of Ag
5. distinguish self from non self i.e. recognizes foreign
IS can distinguish between foreign and self Ag (define self Ag)
The specific immune response has 2 components
1. primary IR
2. secondary IR
primary response
This can be illustrated in a graph showing the different stages as described below
specific Ab appear in blood after 3 – 14 days
latent period (lag phase) involves Ag recognition and development of lymphocyte clones
log phase shows a rise in [Ab] logarithmically until it reaches a peak
IgM is the principal Ab synthesized.
decline phase depicts a drop of [Ab] to very low levels
primary response vs secondary response
(Features of secondary IR that are different to primary IR)
1. more rapid than primary response
2. shorter latent period
3. decreased amount of Ag needed to invoke response
4. more Ab produced
5. decline phase is slower
6. predominant Ab is IgG
7. affinity of Ab increases
remember the above differences as we will be doing an in class exercise using this information.
questions for all students (mainstream and extended group)
Classify the following as either specific, non specific, primary, secondary, non immunogenic:
IV injection of penicillin; Anti diarrhoeal tablets; Inflammation; Sore throat
Fever; Sinusitis; Hay fever; WBC; neutrophils; urine; tears; lysozyme; tea; allergy; no symptoms on exposure to German measles; HIV; AIDS; food; lactose in lactose intolerant people;
1. specificity
IR is specific for specific Ag or specific component of Ag; epitopes/determinants = portion of Ag recognized by lymphocytes
2. memory
IS remembers Ag; therefore the second response = quicker, more intense
3. self regulation
feedback regulation of IR; normal IR wanes/decreases after time, return to dormant state
4. diversity
lymphocytes can respond to a very large number of Ag
5. distinguish self from non self i.e. recognizes foreign
IS can distinguish between foreign and self Ag (define self Ag)
The specific immune response has 2 components
1. primary IR
2. secondary IR
primary response
This can be illustrated in a graph showing the different stages as described below
specific Ab appear in blood after 3 – 14 days
latent period (lag phase) involves Ag recognition and development of lymphocyte clones
log phase shows a rise in [Ab] logarithmically until it reaches a peak
IgM is the principal Ab synthesized.
decline phase depicts a drop of [Ab] to very low levels
primary response vs secondary response
(Features of secondary IR that are different to primary IR)
1. more rapid than primary response
2. shorter latent period
3. decreased amount of Ag needed to invoke response
4. more Ab produced
5. decline phase is slower
6. predominant Ab is IgG
7. affinity of Ab increases
remember the above differences as we will be doing an in class exercise using this information.
questions for all students (mainstream and extended group)
Classify the following as either specific, non specific, primary, secondary, non immunogenic:
IV injection of penicillin; Anti diarrhoeal tablets; Inflammation; Sore throat
Fever; Sinusitis; Hay fever; WBC; neutrophils; urine; tears; lysozyme; tea; allergy; no symptoms on exposure to German measles; HIV; AIDS; food; lactose in lactose intolerant people;
Wednesday, August 3, 2011
lock and key mechanism contd
I can see that a few students are having a problem understanding this concept. Unfortunately I cannot add a picture to this blog. However I have asked you to consult with your matric life science notes. Or you can visit your local library and use their school textbooks or you could search the net. Don't be lazy people, use your initiative
http://www.biologyguide.net/unit1/2_enzymes.htm
http://www.chem4kids.com/files/bio_enzymes.html
try the websites above
http://www.biologyguide.net/unit1/2_enzymes.htm
http://www.chem4kids.com/files/bio_enzymes.html
try the websites above
Tuesday, August 2, 2011
APC's
So how many of you read Victorian novels/romances? Yeah I suppose not many of you are readers, right??? Okay so have any of you watched a like really old movie like Gone with the Wind? where debutantes were presented to society as having learnt all the social graces and are ready for marriage. Obviously all the eligible (rich and handsome helps here) bachelors were invited to these occasions. Rather like a cattle sale, I think..... women for sale (marriage) and men (buyers) on the lookout for the best. Sp how far have we come in South Africa with our interpretation of the debs ball??????
These women were presented and the bill paid by rich relatives, usually old dowager ladies.
So anyway the point I am trying to make here:
APC's (Ag presenting cells) are rather like these old ladies. They present Ag to immune cells (or the immune system) for processing. In most cases ( we will do exceptions later on), Ag will not stimulate an immune response without an APC. Now and APC is not a particular type of cell, but rather a function carried out be specific cells. B cells, monocytes, macrophages, phagocytes, neutrophils, dendritic cells all act as APC's.
These women were presented and the bill paid by rich relatives, usually old dowager ladies.
So anyway the point I am trying to make here:
APC's (Ag presenting cells) are rather like these old ladies. They present Ag to immune cells (or the immune system) for processing. In most cases ( we will do exceptions later on), Ag will not stimulate an immune response without an APC. Now and APC is not a particular type of cell, but rather a function carried out be specific cells. B cells, monocytes, macrophages, phagocytes, neutrophils, dendritic cells all act as APC's.
who are you?
Hi
I have noticed that this blog is being viewed by people other than my intended audience. I have no problem with this. However, I would really appreciate you maybe introducing yourself to me and telling me what benefit you are deriving from this blog. I promise to keep all information confidential. Could you also tell me what field you are involved in?
warm regards
Sherlien
I have noticed that this blog is being viewed by people other than my intended audience. I have no problem with this. However, I would really appreciate you maybe introducing yourself to me and telling me what benefit you are deriving from this blog. I promise to keep all information confidential. Could you also tell me what field you are involved in?
warm regards
Sherlien
Monday, August 1, 2011
classification of specific immune responses
they can be divided into active or passive immunity, and natural or artificial immunity.
in active immunity, energy is expended or used up in creating antibodies. In passive immunity, antibodies are "inherited" or sourced from outside the host's immune system. In a natural immune response, things happen as consequences of day to day living. Artificial immunity refers to us forcing something to take place.
examples:
getting the flu, and recovering is active and natural
immunization is active and artificial
placental transfer is passive and natural
administration of antitoxin is artificial and passive
can you justify the above?
what is the difference between immunization and administration of antitoxin?
what is an antitoxin and in what way does it differ from an antibody?
in active immunity, energy is expended or used up in creating antibodies. In passive immunity, antibodies are "inherited" or sourced from outside the host's immune system. In a natural immune response, things happen as consequences of day to day living. Artificial immunity refers to us forcing something to take place.
examples:
getting the flu, and recovering is active and natural
immunization is active and artificial
placental transfer is passive and natural
administration of antitoxin is artificial and passive
can you justify the above?
what is the difference between immunization and administration of antitoxin?
what is an antitoxin and in what way does it differ from an antibody?
FACTORS INFLUENCING IMMUNOGENICITY CHEMICAL NATURE OF IMMUNOGENS
A. Proteins -The vast majority of immunogens are proteins. These may be pure proteins or they may be glycoproteins or lipoproteins. In general, proteins are usually very good immunogens.
B. Polysaccharides - Pure polysaccharides and lipopolysaccharides are good immunogens.
C. Nucleic Acids - Nucleic acids are usually poorly immunogenic. However, they may become immunogenic when single stranded or when complexed with proteins.
D. Lipids - Lipids are non-immunogenic, although they may be haptens.
question
add these differences to the table you created in the previous post.
Write up the answers/table clearly, with your name and reg no, and bring to class when lectures begin, for assessment.
B. Polysaccharides - Pure polysaccharides and lipopolysaccharides are good immunogens.
C. Nucleic Acids - Nucleic acids are usually poorly immunogenic. However, they may become immunogenic when single stranded or when complexed with proteins.
D. Lipids - Lipids are non-immunogenic, although they may be haptens.
question
add these differences to the table you created in the previous post.
Write up the answers/table clearly, with your name and reg no, and bring to class when lectures begin, for assessment.
FACTORS INFLUENCING IMMUNOGENICITY Contribution of the Immunogen
1. Foreignness - The immune system normally discriminates between self and non-self such that only foreign molecules are immunogenic.
2. Size - There is not absolute size above which a substance will be immunogenic. However, the larger the molecule the more immunogenic it is likely to be.
3. Chemical Composition - The more complex the substance is chemically the more immunogenic it will be. The antigenic determinants are created by the primary sequence of residues in the polymer and/or by the secondary, tertiary or quaternary structure of the molecule.
4. Physical form - Particulate antigens are more immunogenic than soluble ones and denatured antigens more immunogenic than the native form.
5. Degradability - Antigens that are easily phagocytosed are generally more immunogenic. This is because for most antigens (T-dependant antigens) the development of an immune response requires that the antigen be phagocytosed, processed and presented to helper T cells by an antigen.
question
tabulate the differences between immunogenic and non immunogenic for each of the factors described above
2. Size - There is not absolute size above which a substance will be immunogenic. However, the larger the molecule the more immunogenic it is likely to be.
3. Chemical Composition - The more complex the substance is chemically the more immunogenic it will be. The antigenic determinants are created by the primary sequence of residues in the polymer and/or by the secondary, tertiary or quaternary structure of the molecule.
4. Physical form - Particulate antigens are more immunogenic than soluble ones and denatured antigens more immunogenic than the native form.
5. Degradability - Antigens that are easily phagocytosed are generally more immunogenic. This is because for most antigens (T-dependant antigens) the development of an immune response requires that the antigen be phagocytosed, processed and presented to helper T cells by an antigen.
question
tabulate the differences between immunogenic and non immunogenic for each of the factors described above
Thursday, July 28, 2011
cell markers
So how do you recognize another DUT student, even if you dont know him/her? Well these days, its easy cos they are probably looking bored, waiting for lectures to start.
Okay so how do you recognize academic staff of the Biomed dept? I suppose because we look like we belong here, and may have a look of authority about us? I'm not actually sure.
The point i am trying to make is that we use non verbal clues to identify other people.
So how do you suppose cells in the body recognise each other? Do you think they carry signs that say: Hello. I am a Tc cell. Who are you? I think noT!!!!!!!!!!!!!
All cells express (important word used here, remember it) cell markers. A cell marker is a structure found on the surface of a cell. It is not part of the cell membrane, so it cannot be drawn as part of the cell membrane. It is like an address for cells. Different cell markers are found on different cells. Cells 'talk' to each other via cell markers.
Now these cell markers do not actually connect with each other, rather they interact with each other, meaning there is a distinct clear space between each cell marker.
now to the drawing: a spherical shape represents cells. Any shape will represent a cell marker, BUT remember the lock and key mechanism thingy!!!
so i want you to draw me 2 cells interacting with each other via cell markers which 'fit' into each other. NB! no contact between the cell markers. Cell markers are structures on the surface of the cells
now label them as follows:
Tc cell expressing CD8
Th cell expressing CD4
so if we had to write down in words what you just drew:
a Tc cell expressing CD8 interacts with CD4 expressed by Th cell.
makes sense??? if it doesnt, let me know please . Enough for today. Rest now
Okay so how do you recognize academic staff of the Biomed dept? I suppose because we look like we belong here, and may have a look of authority about us? I'm not actually sure.
The point i am trying to make is that we use non verbal clues to identify other people.
So how do you suppose cells in the body recognise each other? Do you think they carry signs that say: Hello. I am a Tc cell. Who are you? I think noT!!!!!!!!!!!!!
All cells express (important word used here, remember it) cell markers. A cell marker is a structure found on the surface of a cell. It is not part of the cell membrane, so it cannot be drawn as part of the cell membrane. It is like an address for cells. Different cell markers are found on different cells. Cells 'talk' to each other via cell markers.
Now these cell markers do not actually connect with each other, rather they interact with each other, meaning there is a distinct clear space between each cell marker.
now to the drawing: a spherical shape represents cells. Any shape will represent a cell marker, BUT remember the lock and key mechanism thingy!!!
so i want you to draw me 2 cells interacting with each other via cell markers which 'fit' into each other. NB! no contact between the cell markers. Cell markers are structures on the surface of the cells
now label them as follows:
Tc cell expressing CD8
Th cell expressing CD4
so if we had to write down in words what you just drew:
a Tc cell expressing CD8 interacts with CD4 expressed by Th cell.
makes sense??? if it doesnt, let me know please . Enough for today. Rest now
lock and key mechanism
This may sound familiar to you, I hope. I think you may have done something similar in enzymes in life sciences.
Do you remember how to draw these? I just need you to be able to show me that one shape 'fits' into or is aligned with the other shape.
Try to draw various lock and key mechanism so that you are familiar with the concept. We are going to need it in the next section.
Do you remember how to draw these? I just need you to be able to show me that one shape 'fits' into or is aligned with the other shape.
Try to draw various lock and key mechanism so that you are familiar with the concept. We are going to need it in the next section.
immune cells
The cells involved in the immune response are called immune cells lol. They can be classified into granulocytes and agranulocytes. Granulocytes are so called because they have ___________ and agaranulocytes have no ________.
Examples of granulocytes are neutrophils, basophils, eosinophils. Examples of agranulocytes are lymphocytes, which can be further classified into T cells and B cells.
question: draw simple unlabelled diagrams to show the differences between each type of cell named above
What cell is often called a PMN? And what does PMN stand for?
T cells are involved in cell mediated immunity (CMI) whilst B cells are involved in humoral immunity (HI). Humoral immunity makes use of Ab to eliminate Ag whilst CMI uses cells to kill Ag. There are different types of T cells, Tc Ts Th and NK cells. Tc is a cytotoxic T cell, Ts is a suppressor T cell, Th is a helper T cell and NK is a natural killer cell. A Tc cell kills, a Ts suppresses or stops the IR, a Th is required to start the IR and the NK cell does what it says, it just kills. All it needs is something to kill.
B cells do not produce Ab. B cells differentiate into plasma cells which produce Ab
Examples of granulocytes are neutrophils, basophils, eosinophils. Examples of agranulocytes are lymphocytes, which can be further classified into T cells and B cells.
question: draw simple unlabelled diagrams to show the differences between each type of cell named above
What cell is often called a PMN? And what does PMN stand for?
T cells are involved in cell mediated immunity (CMI) whilst B cells are involved in humoral immunity (HI). Humoral immunity makes use of Ab to eliminate Ag whilst CMI uses cells to kill Ag. There are different types of T cells, Tc Ts Th and NK cells. Tc is a cytotoxic T cell, Ts is a suppressor T cell, Th is a helper T cell and NK is a natural killer cell. A Tc cell kills, a Ts suppresses or stops the IR, a Th is required to start the IR and the NK cell does what it says, it just kills. All it needs is something to kill.
B cells do not produce Ab. B cells differentiate into plasma cells which produce Ab
benefits of normal flora
Normal flora benefits us.Organisms in the gut produce vitamin K, and help digest carbohydrates. Normal flora on the body surface prevent opportunistic infections. When both man and microbe benefit, the relationship is called mutualism. In commensalism, one party benefits and the other does not. Parasitism refers to harm being done to man by microbes.
It must be noted that if normal flora moves out of their normal area of residence, they can cause severe infections. As an example, E coli is supposed to be in the gut area only; if it gets introduced into the urinary tract it can cause a urinary tract infection (UTI).
It must be noted that if normal flora moves out of their normal area of residence, they can cause severe infections. As an example, E coli is supposed to be in the gut area only; if it gets introduced into the urinary tract it can cause a urinary tract infection (UTI).
Tuesday, July 26, 2011
antimicrobial questions
Do a very quick screen of the shelf in you local supermarket and see how many soaps and
dishwashing liquids claim to be antimicrobial. Also read the packaging and see if it describes what ingredients make it antimicrobial.
Do a screen of friends and family to see who uses an antimicrobial product over a regular product. Ask them why and record the answers.
dishwashing liquids claim to be antimicrobial. Also read the packaging and see if it describes what ingredients make it antimicrobial.
Do a screen of friends and family to see who uses an antimicrobial product over a regular product. Ask them why and record the answers.
normal flora
There are places in/on our body where millions of bacteria reside. They bacteria serve no harm and can even benefit us sometimes. These bacteria are called normal flora. The normal flora is different for different parts of the body. There are some sites of the body taht have no normal flora and are therefore sterile. Examples of sterile sites are the eyes, and CSF.
When we do something to displace or kill the normal flora, we set the scene for opportunistic infections.
An example of normal flora in the gut is E coli. As long as E coli remains within the gut, it will cause no problems. However if it gets introduced into another part of the body, it will cause an infection.
Okay lets talk about antimicrobial soaps like Protex and Dettol. By way of comments, how many of you use either one of these soaps?
So these soaps are claimed to be antimicrobial, which means they will kill microbes. But the question that begs to be asked is: why are we killing our normal flora? If we kill the normal flora, we allow opportunistic pathogens to enter and cause disease. So aren't we causing a bigger problem? The manufacturer's justification for using these soaps is that it will kill pathogens. Now i ask you, how often will you come into contact with pathogens in your day to day activities? Hardly ever. The images shown in the tv adverts show exposure to bacteria in soil and on toys, etc. This is absolute rubbish. Whatever bacteria re on the toys and in the soil will not harm you. Unless it's contaminated with faeces, and somehow I don't think you will be touching something that is faecally contaminated.Makes you think.....
When we do something to displace or kill the normal flora, we set the scene for opportunistic infections.
An example of normal flora in the gut is E coli. As long as E coli remains within the gut, it will cause no problems. However if it gets introduced into another part of the body, it will cause an infection.
Okay lets talk about antimicrobial soaps like Protex and Dettol. By way of comments, how many of you use either one of these soaps?
So these soaps are claimed to be antimicrobial, which means they will kill microbes. But the question that begs to be asked is: why are we killing our normal flora? If we kill the normal flora, we allow opportunistic pathogens to enter and cause disease. So aren't we causing a bigger problem? The manufacturer's justification for using these soaps is that it will kill pathogens. Now i ask you, how often will you come into contact with pathogens in your day to day activities? Hardly ever. The images shown in the tv adverts show exposure to bacteria in soil and on toys, etc. This is absolute rubbish. Whatever bacteria re on the toys and in the soil will not harm you. Unless it's contaminated with faeces, and somehow I don't think you will be touching something that is faecally contaminated.Makes you think.....
opportunistic infections/pathogens
When we are prescribed antibiotics, we are trying to kill the pathogen that is causing all our problems. Now there are two types of antibiotics: broad spectrum and narrow spectrum antibiotics. Broad spectrum antibiotics will kill almost all the microbes inside us, whether they are pathogens or not. We all have millions of microbes within us. They exist in our gut, inside our oral cavity, in our ears, etc. These microbes cause us no harm and are supposed to be there.
Narrow spectrum antibiotics will only kill the pathogens.
In order to be prescribed a narrow spectrum antibiotic, the doctor will need to collect a specimen form you and send it to the lab for processing. Only then will he know what antibiotic to prescribe. But in the surgery there is usually no time to do this. So the doctor will usually prescribe a broad spectrum antibiotic. This is where all our troubles begin.
A good doctor will prescribe an antifungal medication at the same time as the broad spectrum antibiotic. When all the microbes are killed, it allows other microbes that usually dont cause disease to cause disease in you. This is called an opportunistic infection. These microbes get an "opportunity" to cause disease. A classic example of an opportunistic pathogen that will cause infection after you taking a broad spectrum antibiotic is Candida albicans which causes thrush. So taking an antifungal tretment with the antibiotic will prevent this opportunistic infection. Another way of preventing thrush is to eat live culture yoghurt every day that you are taking the antibiotic. Live culture yoghurts replace the microbes that are killed. Or you could even take a probiotic which serves the same function as the yoghurt.
A good doctor will tell you this. A "stupid" doctor will not. You end up with another problem whilst trying to solve one problem. Not nice.
Question time: What organisms are found in live culture yoghurts and probiotics?
How many organism are present in each probiotic tablet?
What are the guidlelines for taking probiotics?
Give one example of a broad spectrum and narrow spectrum antibiotic.
Narrow spectrum antibiotics will only kill the pathogens.
In order to be prescribed a narrow spectrum antibiotic, the doctor will need to collect a specimen form you and send it to the lab for processing. Only then will he know what antibiotic to prescribe. But in the surgery there is usually no time to do this. So the doctor will usually prescribe a broad spectrum antibiotic. This is where all our troubles begin.
A good doctor will prescribe an antifungal medication at the same time as the broad spectrum antibiotic. When all the microbes are killed, it allows other microbes that usually dont cause disease to cause disease in you. This is called an opportunistic infection. These microbes get an "opportunity" to cause disease. A classic example of an opportunistic pathogen that will cause infection after you taking a broad spectrum antibiotic is Candida albicans which causes thrush. So taking an antifungal tretment with the antibiotic will prevent this opportunistic infection. Another way of preventing thrush is to eat live culture yoghurt every day that you are taking the antibiotic. Live culture yoghurts replace the microbes that are killed. Or you could even take a probiotic which serves the same function as the yoghurt.
A good doctor will tell you this. A "stupid" doctor will not. You end up with another problem whilst trying to solve one problem. Not nice.
Question time: What organisms are found in live culture yoghurts and probiotics?
How many organism are present in each probiotic tablet?
What are the guidlelines for taking probiotics?
Give one example of a broad spectrum and narrow spectrum antibiotic.
Monday, July 25, 2011
immuno definitions
there are some words you need to become familiar with.
Antigen is foreign to the body, and when introduced into the body, stimulates the production of specific antibodies
Antibodies are produced by the body in response to antigens and are specific to the antigen
Pathogen is a micro organism capable of causing disease in man.
Immunogenic means capable of stimulating an immune response
Non immunogenic obviously means incapable of stimulating an immune response
Specific immune response (SIR) is the immune response developed by us in response to the antigens we are exposed to. Yours is different to mine. His is different to hers.
Non specific immune response (NSIR) is the immune response we are all born with. Everybody's is the same. It includes examples like tears, intact skin, immune cells, etc
Only complete antigens are immunogenic. Incomplete antigens need to be coupled with a carrier protein before it can become immunogenic. A hapten is an incomplete antigen, therefore it is non immunogenic. Examples of haptens are drugs like analgesics, and antibiotics. I think it is a good idea that we don't develop immune reactions to medication, don't you? Imagine if you produced antibodies to medication???? That would be horrific.
So first question:what is an analgesic? a good example please trade names acceptable
some acceptable abbreviations
Antigen = Ag
antibody = Ab
immune response = IR
SIR and NSIR from above
so I have a situation that needs explaining. Comments please after reading
you have probably heard about penicillin allergies? These patients could have a fatal reaction to penicillin. So if penicillin is an antibiotic, and antibiotics are haptens, how is it possible that people can be allergic to it?
that's all for now.
Antigen is foreign to the body, and when introduced into the body, stimulates the production of specific antibodies
Antibodies are produced by the body in response to antigens and are specific to the antigen
Pathogen is a micro organism capable of causing disease in man.
Immunogenic means capable of stimulating an immune response
Non immunogenic obviously means incapable of stimulating an immune response
Specific immune response (SIR) is the immune response developed by us in response to the antigens we are exposed to. Yours is different to mine. His is different to hers.
Non specific immune response (NSIR) is the immune response we are all born with. Everybody's is the same. It includes examples like tears, intact skin, immune cells, etc
Only complete antigens are immunogenic. Incomplete antigens need to be coupled with a carrier protein before it can become immunogenic. A hapten is an incomplete antigen, therefore it is non immunogenic. Examples of haptens are drugs like analgesics, and antibiotics. I think it is a good idea that we don't develop immune reactions to medication, don't you? Imagine if you produced antibodies to medication???? That would be horrific.
So first question:what is an analgesic? a good example please trade names acceptable
some acceptable abbreviations
Antigen = Ag
antibody = Ab
immune response = IR
SIR and NSIR from above
so I have a situation that needs explaining. Comments please after reading
you have probably heard about penicillin allergies? These patients could have a fatal reaction to penicillin. So if penicillin is an antibiotic, and antibiotics are haptens, how is it possible that people can be allergic to it?
that's all for now.
introduction to immunology2 for semester2 2011
hello dear student.
Its sad that we have to 'meet' like this, but we can't always have what we want. And what we need is time, time to complete (well start at least) the syllabus. Many of you have not been taught by me before, so i suppose this is nice way to meet me, and get used to my style of lecturing.
so i usually begin by asking you : why are you studying immunology or of what use is immunology to your daily life?
well immuno is the study of the immune system. Its really impt cos without an immune system, we all would be dead. The immune system comprises many component, viz the immune cells (lymphocytes), antibodies (IgG, etc), complement and cytokines. We will start with immune cells, but not now.
So tell me, when was the last time you went to the doctor for the flu? and he gave you antibiotics, right? Well did you complete the course of antibiotics? Did he tell you how/why he was prescribing antibiotics? What did you do after you began feeling well, say approx 4 days after beginning the course of antibiotics? Did you stop taking them, and keep them for another occasion? Did you think that you could use the antibiotics when you got sick again?
So did you really get better, or did you feel worse after a few days, and when you resumed taking the antibiotics, did it not help? I know you so well!!!!!!!!!!!!!
so here's the thing!
antibiotics are anti bacteria, which means they work against bacteria. The flu is caused by a virus, which means that antibiotics would not work against them. So why on earth are/were you taking antibiotics?
okay let me help you here. The s&s (signs and symptoms) that you wanted treated were all caused by bacteria. The flu virus weakened your immunity, which allowed a secondary bacterial infection to take hold. The yellow phelgm, sore throat, cough, etc al caused by bacteria.
When you take antibiotics for a few days, the exposure kills a percentage of the bacteria. The bacteria not killed survive and develop resistance to the antibiotic. When you resume taking the antibiotics, it is no longer effective. You have in reality created a resistant species of the bacteria. Hmmm not nice. Almost like the way XDR Tb was created, but that story is for another time.
thats all for now.
Its sad that we have to 'meet' like this, but we can't always have what we want. And what we need is time, time to complete (well start at least) the syllabus. Many of you have not been taught by me before, so i suppose this is nice way to meet me, and get used to my style of lecturing.
so i usually begin by asking you : why are you studying immunology or of what use is immunology to your daily life?
well immuno is the study of the immune system. Its really impt cos without an immune system, we all would be dead. The immune system comprises many component, viz the immune cells (lymphocytes), antibodies (IgG, etc), complement and cytokines. We will start with immune cells, but not now.
So tell me, when was the last time you went to the doctor for the flu? and he gave you antibiotics, right? Well did you complete the course of antibiotics? Did he tell you how/why he was prescribing antibiotics? What did you do after you began feeling well, say approx 4 days after beginning the course of antibiotics? Did you stop taking them, and keep them for another occasion? Did you think that you could use the antibiotics when you got sick again?
So did you really get better, or did you feel worse after a few days, and when you resumed taking the antibiotics, did it not help? I know you so well!!!!!!!!!!!!!
so here's the thing!
antibiotics are anti bacteria, which means they work against bacteria. The flu is caused by a virus, which means that antibiotics would not work against them. So why on earth are/were you taking antibiotics?
okay let me help you here. The s&s (signs and symptoms) that you wanted treated were all caused by bacteria. The flu virus weakened your immunity, which allowed a secondary bacterial infection to take hold. The yellow phelgm, sore throat, cough, etc al caused by bacteria.
When you take antibiotics for a few days, the exposure kills a percentage of the bacteria. The bacteria not killed survive and develop resistance to the antibiotic. When you resume taking the antibiotics, it is no longer effective. You have in reality created a resistant species of the bacteria. Hmmm not nice. Almost like the way XDR Tb was created, but that story is for another time.
thats all for now.
Friday, May 20, 2011
chempathexam2
Chemical Pathology 3 Page 2 of 8 June 2008
1.1 Gugu was admitted to the local clinic and it was discovered that her ionised calcium level dropped. Describe the sequence of events that will occur to re establish homeostasis.
[8]
1.2 There are special precautions that must be taken in collection of blood for the measurement of ionised calcium. Discuss these and explain why they are necessary.
[5]
1.3 A report on a male patient read as follows: Calcium : 2.25 mmol/1
Phosphate : 0.98 mmol/1
Magnesium : 0.50 mmol/1
1.3.1 Explain the above results and give the possible diagnosis. [Give reasons for the abnormal result(s)]
[7]
1.3.2 What would the treatment be for the above patient? [1]
[21]
2.1 State whether the following statements are true or false. If false, correct the statement. [f mark for True or False -1 mark for an explanation of the incorrect statement]
2.1.1 In a work flow system, input refers to specimens, request forms and reagents.
2.1.2 For critical care patients, specimens are collected less frequently.
2.1.3 PTH is present in skin and from diet.
2.1.4 One of the causes of hyperphoshatemia is hypothyroidism.
2.1.5 EGTA binds to Mg so that one can measure the calcium content in the patient's sample.
2.1.6 Aldosterone is antagonistic in that it increases serum Mg by promoting excretion by kidney.
2.1.7 Iron transport is via transferrin where each molecule binds two Fe 2
ions.
2.1.8 A fetal lung maturity is when the LSAR may be 1.5, PG positive.
[10]
2.2 How many milliliters of concentrated HN03 are required to prepare 3 L of
0.35 M HN03? [5]
2.3 Determine the molarity, normality, and'}'.(w/v) for a solution containing
40 g of NaCI in 300 mls of distilled water.
[9]
2.4 Convert the following;
155mg/dl glucose solution to millimoles per litre. [5]
2.5 Calculate the recovery of the following Fe sample.
Sample 1: 1.0 ml serum+ 0.2 ml H20
Sample 2: 1.0 ml serum + 0.2 ml 10 J.hTIOI/1 standard
Concentration:
Sample 1
Sample 2
Fe measured
31.0 J.hTIOI/1
32.5 j.hTiol/1
[9]
Additional information:
Molar mass:
K 39
0 16
Cl 35.5 H 1
N 14 Na 23
s 32 c 12
HN03 (sp gr = 1.42 g/mL; assay= 70'ro)
[38]
-------------- •.• - -
Chemical Pathology 3 Page 5 of 8 June 2008
3.1 A 44- year- old white man from Mpumalanga presented with weight loss, lassitude and weakness. His skin appeared bronze, which was unusual as there was little sun during this time of the year. When examined, it appeared that he had hepatosplenomegaly.
Lab results: Urine
Blood glucose (F)
Serum: Iron Transferrin Ferritin
positive for glucose
10.0 mmol/1
50 umol/1
3.33 g/1
2050 ug/1
3.1.1 Explain the results and give a possible diagnosis. Show clearly how you derive at the conclusions. [10]
3.1.2 In cases like these, state what is further done. [1]
3.1.3 Explain all the factors to be taken when iron is measured.
I
[8]
3.2 Make recommendations of how space could be best utilized when designing a laboratory. [10]
[29]
Chemical Pathology 3 Page 6 of 8 June 2008
jJ
4.1.1 Write all the precautions of the globulin test for CSF measurement. [5]
4.1.2 If a blood stained CSF arrives at the Chemical Pathology laboratory what do you do and specify what tests are done?
[3]
4.1.3 What are the reference ranges for CSF protein and glucose? Use current
SI units.
[2]
4.1.4 Describe the significance of CSF glutamine. [1]
4.2.1 Explain the term occult blood, with details of the type of specimen
required for analysis. [3]
4.2.2 Give 3 cases where one can get a positive result. [3]
4.2.3 Explain how one can obtain a false positive result. [1]
4.2.4 Name a type of occult blood test that may be obtained from suppliers I
manufacturers. [1]
4.3 A fluid was received in the laboratory and the requesting doctor had indicated that he wanted to confirm if the fluid was an exudate or transudate. Tabulate the differences so that a diagnosis can be made.
[10] [28]
••
Chemical Pathology 3 Page 7 of 8 June 2008
5.1.1 A 22-year-old Librarian went to her family doctor as she noticed that her skin was becoming moist quite often. She was told by her colleagues that she should visit her doctor as t her eyes seemed to have become more prominent and that she was losing weight. On examination her doctor noted that she had a slightly enlarged thyroid gland.
Blood tests showed the following: TSH < 0.1 mU/L
fT4 33 pmol/1 fT3 8 pmol/1
The scan perform showed an enlarged gland. Autoantibodies to thyroid
peroxidase and thyroglobulin were present in the serum in high titre. Discuss the above case with possible diagnosis.
[6]
5.1.2 Explain what is meant by negative feedback inhibition using thyroid
hormone cis an example. [6]
5.2 Write notes on:
5. .1 Cortisol
5.2.2 Testosterone [10]
5.3 Explain the principle used in RAST technique. [5]
5.4 Assays in an Endocrinology Laboratory are subject to assay robustness.
Heterophile antibodies and the 'hook effect' are just 2 examples that affect assays. Using a hormone as an example comment on these and discuss how they are overcome.
[8] [35]
Chemical Pathology 3 Page 8 of 8 June 2008
>
6.1 A 2 year - old child swallowed some pills that was left open, was seen at the paediatric casualty ward. It was discovered that these were aspirin. Discuss the possible symptoms and treatment. State as well the analysis for salicylate.
[8]
6.2 Differentiate between the following (with regards to pharmacology):
6.2.1 A loading dose and a maintenance dose
6.2.2 First order and zero order kinetics
6.2.3 Intrinsic activity and affinity [6]
6.3. State the class or type of drug, the mode of action and the main toxic effect of three (3) of the following drugs:-
6.3.1 Lidocaine
6.3.2 Chloramphenicol
6.3.3 Digoxin
6.3.4 Carbamaxapine [9]
[23]
Chemical Pathology 3 CPAT 303-2009 mid- year Main exam
A 58-year-old woman was investigated after two episodes of ureteric colic, shown on radiological examination to be due to calcium-containing calculi. She also complained of constipation, although she previously had normal bowel movements, but was otherwise well. No abnormality was found on physical examination.
Investigations
Serum: Calcium Phosphate Total C02
PTH (intact hormone assay)
2.98 mmol/1
0.75 mmol/1
20 mmol/1
155 ng/1
[reference range 10-65 ng/1]
Bone radiographs normal
Serum urea, albumin and alkaline phosphatase : all normal
1.1.1 Provide a diagnosis for the above case giving reasons. [8]
1.1.2 Discuss all the precautions when obtaining specimens for serum and urine calcium.
1.1.3 Discuss the homeostasis of phosphorus.
[9] [9]
1.1.4 Name a method for phosphate determination. Describe the method used.
[4]
[30]
..
Chemical Pathology 3 CPAT 303- 2009 mid- year Main exam
2.1 A 50-year-old man presented with weight Joss and weakness. The time of the year was winter but his skin was noticeably bronzed. On examination, he was found to have hepatosplenomegaly.
Investigations
Urine
Blood sugar
Serum
Iron Transferrin Ferritin
positive for glucose
12 mmol/1
58 .umol/1
2.15 g/1
350o- ,ug/ml
2.1.1 Predict the diagnosis of the patient. Justify your answer with explanations ana show calculations. [8]
2.1.2 Briefly describe the methodology of the three analytes above. [6]
2.1.3 What is transferrin? Explain its significance and give cases where there are elevated results and also cases where its levels are decreased. [10]
[24]
3.1.2 In terms of the workflow process in the laboratory, detail the collection and delivery of specimens in a modern laboratory. [14]
3.2 Provide an explanation I reasons for the following:
3.2.1
3.2.2
3.2.3
3.3.4
3.3.5
Tumor markers are processed in a batch. Two - way traffic of samples and reports. Receptions area should be free of clutter. Bulk of the work is done in the first shift. Transcription mistakes are not allowed.
[10]
[30]
4.1.1 What types of patients are given lithium? Explain its use. [3]
4.1,2 Describe the sample of choice and symptoms of overdose. [3]
4.1.3 Give the reference values and methods of detection. [6]
4.2 There was much media speculation of meningitis in this country as many patients had signs and symptoms of the condition and a few patients died from the illness.
4.2.1 Explain the collection of specimen of choice. [2]
4.2.2Discuss the various tubes taken and the reasons thereof. [4]
4.2.3 Name all the tests done in a Chemical Pathology lab for CSF analysis and explain its significance. [16]
4.3.1 In occult blood analysis discuss the interfering factors that give false
results. [2]
4.3.2 What are the limitations to the sensitivity and specificity of this assay? [2]
[38]
5.1 The thyroid gland is a small tissue situated in the neck just below the larynx (voice box). Its hormones increase the basal metabolic rate - necessary for proper growth and development.
Thyroid ism is a condition that is often not diagnosed by doctors as they seek to find other reasons for symptoms experienced by their patients.
5.1.1 Explain the evaluation of thyroid function. [3]
5.1.2 TSH and T4 are used for diagnosis. Indicate whether these hormones are increased or decreased in the following states:
5.1.2.1 Primary hypofunction
5.1.2.2 Secondary hypofunction
5.1.2.3 Tertiary hypofunction
5.1.2.4 Hyperfunction [8]
5.1.3 Discuss the differences between hypothyroidism and hyperthyroidism.
[12]
5.2 Release of ACTH is regu'lated by corticotrophin releasing factor and results in increased cortisol synthesis. Determine the values of these hormones in the various diseased states.
[6]
[29]
6.1 Give the therapeutic range, toxic level and toxic effects of three (3) of the following drugs:
6.1.1 Digoxin
6.1.2 Phenytoin
6.1.3 Phenobarbitone
6.1.4 Theophylline
[12]
6.2 Explain the methodology of five (5) drugs. [5]
•• ' 6.3 Describe the factors which may affect drug level assays and interpretation.
[7] [24]
1.1 Gugu was admitted to the local clinic and it was discovered that her ionised calcium level dropped. Describe the sequence of events that will occur to re establish homeostasis.
[8]
1.2 There are special precautions that must be taken in collection of blood for the measurement of ionised calcium. Discuss these and explain why they are necessary.
[5]
1.3 A report on a male patient read as follows: Calcium : 2.25 mmol/1
Phosphate : 0.98 mmol/1
Magnesium : 0.50 mmol/1
1.3.1 Explain the above results and give the possible diagnosis. [Give reasons for the abnormal result(s)]
[7]
1.3.2 What would the treatment be for the above patient? [1]
[21]
2.1 State whether the following statements are true or false. If false, correct the statement. [f mark for True or False -1 mark for an explanation of the incorrect statement]
2.1.1 In a work flow system, input refers to specimens, request forms and reagents.
2.1.2 For critical care patients, specimens are collected less frequently.
2.1.3 PTH is present in skin and from diet.
2.1.4 One of the causes of hyperphoshatemia is hypothyroidism.
2.1.5 EGTA binds to Mg so that one can measure the calcium content in the patient's sample.
2.1.6 Aldosterone is antagonistic in that it increases serum Mg by promoting excretion by kidney.
2.1.7 Iron transport is via transferrin where each molecule binds two Fe 2
ions.
2.1.8 A fetal lung maturity is when the LSAR may be 1.5, PG positive.
[10]
2.2 How many milliliters of concentrated HN03 are required to prepare 3 L of
0.35 M HN03? [5]
2.3 Determine the molarity, normality, and'}'.(w/v) for a solution containing
40 g of NaCI in 300 mls of distilled water.
[9]
2.4 Convert the following;
155mg/dl glucose solution to millimoles per litre. [5]
2.5 Calculate the recovery of the following Fe sample.
Sample 1: 1.0 ml serum+ 0.2 ml H20
Sample 2: 1.0 ml serum + 0.2 ml 10 J.hTIOI/1 standard
Concentration:
Sample 1
Sample 2
Fe measured
31.0 J.hTIOI/1
32.5 j.hTiol/1
[9]
Additional information:
Molar mass:
K 39
0 16
Cl 35.5 H 1
N 14 Na 23
s 32 c 12
HN03 (sp gr = 1.42 g/mL; assay= 70'ro)
[38]
-------------- •.• - -
Chemical Pathology 3 Page 5 of 8 June 2008
3.1 A 44- year- old white man from Mpumalanga presented with weight loss, lassitude and weakness. His skin appeared bronze, which was unusual as there was little sun during this time of the year. When examined, it appeared that he had hepatosplenomegaly.
Lab results: Urine
Blood glucose (F)
Serum: Iron Transferrin Ferritin
positive for glucose
10.0 mmol/1
50 umol/1
3.33 g/1
2050 ug/1
3.1.1 Explain the results and give a possible diagnosis. Show clearly how you derive at the conclusions. [10]
3.1.2 In cases like these, state what is further done. [1]
3.1.3 Explain all the factors to be taken when iron is measured.
I
[8]
3.2 Make recommendations of how space could be best utilized when designing a laboratory. [10]
[29]
Chemical Pathology 3 Page 6 of 8 June 2008
jJ
4.1.1 Write all the precautions of the globulin test for CSF measurement. [5]
4.1.2 If a blood stained CSF arrives at the Chemical Pathology laboratory what do you do and specify what tests are done?
[3]
4.1.3 What are the reference ranges for CSF protein and glucose? Use current
SI units.
[2]
4.1.4 Describe the significance of CSF glutamine. [1]
4.2.1 Explain the term occult blood, with details of the type of specimen
required for analysis. [3]
4.2.2 Give 3 cases where one can get a positive result. [3]
4.2.3 Explain how one can obtain a false positive result. [1]
4.2.4 Name a type of occult blood test that may be obtained from suppliers I
manufacturers. [1]
4.3 A fluid was received in the laboratory and the requesting doctor had indicated that he wanted to confirm if the fluid was an exudate or transudate. Tabulate the differences so that a diagnosis can be made.
[10] [28]
••
Chemical Pathology 3 Page 7 of 8 June 2008
5.1.1 A 22-year-old Librarian went to her family doctor as she noticed that her skin was becoming moist quite often. She was told by her colleagues that she should visit her doctor as t her eyes seemed to have become more prominent and that she was losing weight. On examination her doctor noted that she had a slightly enlarged thyroid gland.
Blood tests showed the following: TSH < 0.1 mU/L
fT4 33 pmol/1 fT3 8 pmol/1
The scan perform showed an enlarged gland. Autoantibodies to thyroid
peroxidase and thyroglobulin were present in the serum in high titre. Discuss the above case with possible diagnosis.
[6]
5.1.2 Explain what is meant by negative feedback inhibition using thyroid
hormone cis an example. [6]
5.2 Write notes on:
5. .1 Cortisol
5.2.2 Testosterone [10]
5.3 Explain the principle used in RAST technique. [5]
5.4 Assays in an Endocrinology Laboratory are subject to assay robustness.
Heterophile antibodies and the 'hook effect' are just 2 examples that affect assays. Using a hormone as an example comment on these and discuss how they are overcome.
[8] [35]
Chemical Pathology 3 Page 8 of 8 June 2008
>
6.1 A 2 year - old child swallowed some pills that was left open, was seen at the paediatric casualty ward. It was discovered that these were aspirin. Discuss the possible symptoms and treatment. State as well the analysis for salicylate.
[8]
6.2 Differentiate between the following (with regards to pharmacology):
6.2.1 A loading dose and a maintenance dose
6.2.2 First order and zero order kinetics
6.2.3 Intrinsic activity and affinity [6]
6.3. State the class or type of drug, the mode of action and the main toxic effect of three (3) of the following drugs:-
6.3.1 Lidocaine
6.3.2 Chloramphenicol
6.3.3 Digoxin
6.3.4 Carbamaxapine [9]
[23]
Chemical Pathology 3 CPAT 303-2009 mid- year Main exam
A 58-year-old woman was investigated after two episodes of ureteric colic, shown on radiological examination to be due to calcium-containing calculi. She also complained of constipation, although she previously had normal bowel movements, but was otherwise well. No abnormality was found on physical examination.
Investigations
Serum: Calcium Phosphate Total C02
PTH (intact hormone assay)
2.98 mmol/1
0.75 mmol/1
20 mmol/1
155 ng/1
[reference range 10-65 ng/1]
Bone radiographs normal
Serum urea, albumin and alkaline phosphatase : all normal
1.1.1 Provide a diagnosis for the above case giving reasons. [8]
1.1.2 Discuss all the precautions when obtaining specimens for serum and urine calcium.
1.1.3 Discuss the homeostasis of phosphorus.
[9] [9]
1.1.4 Name a method for phosphate determination. Describe the method used.
[4]
[30]
..
Chemical Pathology 3 CPAT 303- 2009 mid- year Main exam
2.1 A 50-year-old man presented with weight Joss and weakness. The time of the year was winter but his skin was noticeably bronzed. On examination, he was found to have hepatosplenomegaly.
Investigations
Urine
Blood sugar
Serum
Iron Transferrin Ferritin
positive for glucose
12 mmol/1
58 .umol/1
2.15 g/1
350o- ,ug/ml
2.1.1 Predict the diagnosis of the patient. Justify your answer with explanations ana show calculations. [8]
2.1.2 Briefly describe the methodology of the three analytes above. [6]
2.1.3 What is transferrin? Explain its significance and give cases where there are elevated results and also cases where its levels are decreased. [10]
[24]
3.1.2 In terms of the workflow process in the laboratory, detail the collection and delivery of specimens in a modern laboratory. [14]
3.2 Provide an explanation I reasons for the following:
3.2.1
3.2.2
3.2.3
3.3.4
3.3.5
Tumor markers are processed in a batch. Two - way traffic of samples and reports. Receptions area should be free of clutter. Bulk of the work is done in the first shift. Transcription mistakes are not allowed.
[10]
[30]
4.1.1 What types of patients are given lithium? Explain its use. [3]
4.1,2 Describe the sample of choice and symptoms of overdose. [3]
4.1.3 Give the reference values and methods of detection. [6]
4.2 There was much media speculation of meningitis in this country as many patients had signs and symptoms of the condition and a few patients died from the illness.
4.2.1 Explain the collection of specimen of choice. [2]
4.2.2Discuss the various tubes taken and the reasons thereof. [4]
4.2.3 Name all the tests done in a Chemical Pathology lab for CSF analysis and explain its significance. [16]
4.3.1 In occult blood analysis discuss the interfering factors that give false
results. [2]
4.3.2 What are the limitations to the sensitivity and specificity of this assay? [2]
[38]
5.1 The thyroid gland is a small tissue situated in the neck just below the larynx (voice box). Its hormones increase the basal metabolic rate - necessary for proper growth and development.
Thyroid ism is a condition that is often not diagnosed by doctors as they seek to find other reasons for symptoms experienced by their patients.
5.1.1 Explain the evaluation of thyroid function. [3]
5.1.2 TSH and T4 are used for diagnosis. Indicate whether these hormones are increased or decreased in the following states:
5.1.2.1 Primary hypofunction
5.1.2.2 Secondary hypofunction
5.1.2.3 Tertiary hypofunction
5.1.2.4 Hyperfunction [8]
5.1.3 Discuss the differences between hypothyroidism and hyperthyroidism.
[12]
5.2 Release of ACTH is regu'lated by corticotrophin releasing factor and results in increased cortisol synthesis. Determine the values of these hormones in the various diseased states.
[6]
[29]
6.1 Give the therapeutic range, toxic level and toxic effects of three (3) of the following drugs:
6.1.1 Digoxin
6.1.2 Phenytoin
6.1.3 Phenobarbitone
6.1.4 Theophylline
[12]
6.2 Explain the methodology of five (5) drugs. [5]
•• ' 6.3 Describe the factors which may affect drug level assays and interpretation.
[7] [24]
chempathexam1
1. Multiple choices. Show working I explanation and give the correct answer.
1.1 In a spectrophotometric procedure that follows Beer's law, the absorbance of a standard solution of concentration 15 mmol/1 is 0.5 in a 1 em cell. The absorbance of the sample solution is 0.62. What is the concentration?
A. 0.62 mmolll
B. 6.2 mmol/1
C. 12.1 mmol/1
D. 18.6 mmol/1
1.2 How many grams of sulphosalicyclic acid (Mol weight 254g) are required to prepare 1 litre of a 3% solution?
A. 3.0
B. 7.6
c. 30
D. 254
1.3 How many grams of HzS04 are required to prepare 750 ml of a 2M solution?
A. 36.8
B. 73.5
c. 98
D. 147
• 1.4 A batch of test results is out- of- control . What should you do first?
A. Report the results to the physician first, then look for the trouble.
B. Follow the "out- of- control" procedure specified for the test method. C. Repeat the tests with a new lot of standards (calibrators)
D. Repeat the tests with a new lot of reagents.
1.5 How many grams ofNaOH are required to prepare 4 L of a 2M solution?
A. 40
B. 80
c. 160
D. 320
1.6 How many milliliters of concentrated HN03 (sp gr = 1.42 g/ml; assay= 70%) are required to prepare 21of a 0.15 M HN03?
A. 13.3
B. 19.0
c. 38.0
D. 189.0
1.7 An analysis for sodium is performed on an aliquot of a 24 hr urine specimen. A sodium value of 122.5 mmol/1 is read from the instrument. What is the amount of sodium in the 24 hour urine specimen if 1540 ml of urine are collected?
A. 79.5
B. 188.6
C. 1886.5
D. 18.8865
1.8 What is the relative centrifugal force (x g) of a centrifuge operating at 2500 rpm with a •
radius of 10cm? A. 625
B. 699
C. 1250
D. 6988
1.9 What amount ofNaCl is needed to obtain 50 mg Cl?
A. 19.6 mg B. 30.0mg C. 50.0 mg
D. 82.4mg
1.10 Which of the following is an effect of increased PTH secretion?
A. Decreased blood calcium levels
. B. Increased renal reabsorption of phosphate
C. Decreased bone resorption
D. Increased intestinal absorption of calcium
[10x2=20] .
Molecular mass:
H 1 S 32 016 Na 23 Cl 35.5 N 14
2.1 Calculate the amount of chemical you must weigh out to prepare the following: -
2.1.1
2.1.2
2.1.3 [Na23
150 ml of a 0.3 M sodium carbonate.
250 ml of sodium chloride; 500 mmol/1
750 ml of0.83% sodium chloride
C 12 0 16 Cl 35.45 ]
[9]
2.2 In a new lab in eThekwini the QC officer decided to perform a recovery study for Iron using a new methodology. The sample preparations were as follows:
Sample 1: 5.0 ml serum+ 0.5 ml H20
Sample 2: 5.0 m1 serum+ 0.5 ml 75 J.lmoVI Fe Std
Sample 3: 5.0 ml serum+ 0.5 ml100 !lmoVI Fe Std
The concentrations were as follows:
Sample 1
Sample 2
Sample 3
Fe Measured
8 J.liDOI/1
12 J.lmol/1
15 J.lmol/1
2.2.1 Calculate the % recovery for sample 2 and sample 3. [15]
2.2.2 Giving reasons indicate which of the two samples perform better.
[2]
2.3 Discuss the concept of accreditation. [6]
[32)
3.1 Betty is a 42 year- old overweight woman who presented with the complaint of cramps and 'spasms' of both hands. On examination she was found to be severely depressed and she further indicated that she had a thyroidectomy ten years prior. The pertinent biochemical findings were:
Plasma Creatinine Ca
ALP
Alb
85 !-!IDOl/]
1.28 mmol/1
65 U/L
39 g/1
3.1.1 Comment on the results and give possible diagnosis. Discuss all the possible reasons for such results. [6]
3.1.2 Name the various methods for calcium determination. Describe any principle (in detail)
that may be used for calcium determination in a Chern Path lab. [7]
3.1.3 Discuss the homeostasis of calcium. [10]
3.2 Lithium may be administered as lithium carbonate or lithium citrate and is used for the treatment on manic depression -manic depressive psychosis. Overdose may be life threatening.
3.2.1 Explain all the signs and symptoms of lithium toxicity. Indicate what happens after ingestion. [6]
3.2.2 Describe the methods used for lithium detection. [3]
4.1 In a Chemical Pathology laboratory, a CSF is considered a 'Stat' sample.
[32)
4.1.1 Discuss the pathological variation of this fluid, with reference to the macroscopic appearance and colour. [7]
4.1.2 Give the reference range for CSF chloride and explain a case when abnormal.
Name methods used for CSF chloride measurement. [4]
4.2. Fluids are often received in major laboratories. Discuss four (4) of the following fluids:
4.2.1 Amniotic fluid
4.2.2 Sweat
4.2.3 Synovial fluid
4.2.4 Serous fluid
4.2.5 Pleural fluid
4.3 Provide an explanation I reasons for the following:
4.3 .1 A request form is a very important document and must be filled in accurately.
[12]
4.3.2 Labs make booklets that are distributed to areas I sections where blood is taken.
4.3.3 Barcodes must be of good quality.
4.3.4 A hard copy of the results is usually kept in the laboratory.
4.3.5 When designing a lab, it is imperative to look at bench heights.
4.3.6 Tests that are expensive are usually grouped and run as a batch.
4.3.7 Messengers or couriers tend to delay delivery of specimens to the lab.
4.3.8 Qualified medical technologists verify results.
4.3.9 Chemical Pathology labs are mainly automated.
4.3 .10 Medical Technology staff are highly sought after.
[10]
[33]
5.1 A 25 year old woman presented with a moderate painless goitre and difficulty in swallowing. She was anxious and has a noticeable tremor of her fingers. The doctor examined her and indicated that her neck was swelling, was diffuse and tender.
The thyroid results revealed:
rT4 45 nrnol/1
TSH 0.01 miU/1
Antibodies to the thyroid gland were done and came back negative.
5.1.1 Judging from the results, give the clinical picture of the patient. [6]
5.1.2 Discuss the evaluation of thyroid function and some of the typical signs for the above condition. [12]
5.2 Differentiate between the various types of hypothyroidism, explaining the tests used for its diagnosis.
[7]
[25]
6. Recently doctors are increasingly attending to patients who are suspected of taking drugs.
6.1. Describe the rationale that is used for requesting a serum drug assay. [10]
6.2 Discuss the 5 classification of drugs that are frequently encounted in overdose situations. [10]
6.3 There are several factors that influence toxicology. Describe these where if untreated it may be fatal. [6]
6.4 Briefly outline the effects of ingestion of salicylates (aspirin) in overdose cases.
[7]
[33]
1.1 In a spectrophotometric procedure that follows Beer's law, the absorbance of a standard solution of concentration 15 mmol/1 is 0.5 in a 1 em cell. The absorbance of the sample solution is 0.62. What is the concentration?
A. 0.62 mmolll
B. 6.2 mmol/1
C. 12.1 mmol/1
D. 18.6 mmol/1
1.2 How many grams of sulphosalicyclic acid (Mol weight 254g) are required to prepare 1 litre of a 3% solution?
A. 3.0
B. 7.6
c. 30
D. 254
1.3 How many grams of HzS04 are required to prepare 750 ml of a 2M solution?
A. 36.8
B. 73.5
c. 98
D. 147
• 1.4 A batch of test results is out- of- control . What should you do first?
A. Report the results to the physician first, then look for the trouble.
B. Follow the "out- of- control" procedure specified for the test method. C. Repeat the tests with a new lot of standards (calibrators)
D. Repeat the tests with a new lot of reagents.
1.5 How many grams ofNaOH are required to prepare 4 L of a 2M solution?
A. 40
B. 80
c. 160
D. 320
1.6 How many milliliters of concentrated HN03 (sp gr = 1.42 g/ml; assay= 70%) are required to prepare 21of a 0.15 M HN03?
A. 13.3
B. 19.0
c. 38.0
D. 189.0
1.7 An analysis for sodium is performed on an aliquot of a 24 hr urine specimen. A sodium value of 122.5 mmol/1 is read from the instrument. What is the amount of sodium in the 24 hour urine specimen if 1540 ml of urine are collected?
A. 79.5
B. 188.6
C. 1886.5
D. 18.8865
1.8 What is the relative centrifugal force (x g) of a centrifuge operating at 2500 rpm with a •
radius of 10cm? A. 625
B. 699
C. 1250
D. 6988
1.9 What amount ofNaCl is needed to obtain 50 mg Cl?
A. 19.6 mg B. 30.0mg C. 50.0 mg
D. 82.4mg
1.10 Which of the following is an effect of increased PTH secretion?
A. Decreased blood calcium levels
. B. Increased renal reabsorption of phosphate
C. Decreased bone resorption
D. Increased intestinal absorption of calcium
[10x2=20] .
Molecular mass:
H 1 S 32 016 Na 23 Cl 35.5 N 14
2.1 Calculate the amount of chemical you must weigh out to prepare the following: -
2.1.1
2.1.2
2.1.3 [Na23
150 ml of a 0.3 M sodium carbonate.
250 ml of sodium chloride; 500 mmol/1
750 ml of0.83% sodium chloride
C 12 0 16 Cl 35.45 ]
[9]
2.2 In a new lab in eThekwini the QC officer decided to perform a recovery study for Iron using a new methodology. The sample preparations were as follows:
Sample 1: 5.0 ml serum+ 0.5 ml H20
Sample 2: 5.0 m1 serum+ 0.5 ml 75 J.lmoVI Fe Std
Sample 3: 5.0 ml serum+ 0.5 ml100 !lmoVI Fe Std
The concentrations were as follows:
Sample 1
Sample 2
Sample 3
Fe Measured
8 J.liDOI/1
12 J.lmol/1
15 J.lmol/1
2.2.1 Calculate the % recovery for sample 2 and sample 3. [15]
2.2.2 Giving reasons indicate which of the two samples perform better.
[2]
2.3 Discuss the concept of accreditation. [6]
[32)
3.1 Betty is a 42 year- old overweight woman who presented with the complaint of cramps and 'spasms' of both hands. On examination she was found to be severely depressed and she further indicated that she had a thyroidectomy ten years prior. The pertinent biochemical findings were:
Plasma Creatinine Ca
ALP
Alb
85 !-!IDOl/]
1.28 mmol/1
65 U/L
39 g/1
3.1.1 Comment on the results and give possible diagnosis. Discuss all the possible reasons for such results. [6]
3.1.2 Name the various methods for calcium determination. Describe any principle (in detail)
that may be used for calcium determination in a Chern Path lab. [7]
3.1.3 Discuss the homeostasis of calcium. [10]
3.2 Lithium may be administered as lithium carbonate or lithium citrate and is used for the treatment on manic depression -manic depressive psychosis. Overdose may be life threatening.
3.2.1 Explain all the signs and symptoms of lithium toxicity. Indicate what happens after ingestion. [6]
3.2.2 Describe the methods used for lithium detection. [3]
4.1 In a Chemical Pathology laboratory, a CSF is considered a 'Stat' sample.
[32)
4.1.1 Discuss the pathological variation of this fluid, with reference to the macroscopic appearance and colour. [7]
4.1.2 Give the reference range for CSF chloride and explain a case when abnormal.
Name methods used for CSF chloride measurement. [4]
4.2. Fluids are often received in major laboratories. Discuss four (4) of the following fluids:
4.2.1 Amniotic fluid
4.2.2 Sweat
4.2.3 Synovial fluid
4.2.4 Serous fluid
4.2.5 Pleural fluid
4.3 Provide an explanation I reasons for the following:
4.3 .1 A request form is a very important document and must be filled in accurately.
[12]
4.3.2 Labs make booklets that are distributed to areas I sections where blood is taken.
4.3.3 Barcodes must be of good quality.
4.3.4 A hard copy of the results is usually kept in the laboratory.
4.3.5 When designing a lab, it is imperative to look at bench heights.
4.3.6 Tests that are expensive are usually grouped and run as a batch.
4.3.7 Messengers or couriers tend to delay delivery of specimens to the lab.
4.3.8 Qualified medical technologists verify results.
4.3.9 Chemical Pathology labs are mainly automated.
4.3 .10 Medical Technology staff are highly sought after.
[10]
[33]
5.1 A 25 year old woman presented with a moderate painless goitre and difficulty in swallowing. She was anxious and has a noticeable tremor of her fingers. The doctor examined her and indicated that her neck was swelling, was diffuse and tender.
The thyroid results revealed:
rT4 45 nrnol/1
TSH 0.01 miU/1
Antibodies to the thyroid gland were done and came back negative.
5.1.1 Judging from the results, give the clinical picture of the patient. [6]
5.1.2 Discuss the evaluation of thyroid function and some of the typical signs for the above condition. [12]
5.2 Differentiate between the various types of hypothyroidism, explaining the tests used for its diagnosis.
[7]
[25]
6. Recently doctors are increasingly attending to patients who are suspected of taking drugs.
6.1. Describe the rationale that is used for requesting a serum drug assay. [10]
6.2 Discuss the 5 classification of drugs that are frequently encounted in overdose situations. [10]
6.3 There are several factors that influence toxicology. Describe these where if untreated it may be fatal. [6]
6.4 Briefly outline the effects of ingestion of salicylates (aspirin) in overdose cases.
[7]
[33]
Monday, May 9, 2011
tb lab safety rules and regulations
employ all measures to decrease aerosol production
use class 1 or IIA safety cabinet with a negative pressure and external exhaust system
centrifuges must have carrier shields or aerosol free tops
lab personnel must use face masks, gloves, gowns and shoe covers
use a germicide to decontaminate work benches
employees must be screened with PPD and have a chest xray annually
the lab should be separate from other parts of the lab
use class 1 or IIA safety cabinet with a negative pressure and external exhaust system
centrifuges must have carrier shields or aerosol free tops
lab personnel must use face masks, gloves, gowns and shoe covers
use a germicide to decontaminate work benches
employees must be screened with PPD and have a chest xray annually
the lab should be separate from other parts of the lab
Wednesday, April 6, 2011
haem theory test results
Stud No test 1
20601437 45
20609404 58
20618192 57
20712767 46
20720801 38
20800671 84
20800802 75
20801222 86
20801605 55
20801953 61
20802816 56
20802921 81
20805033 55
20810971 68
20813848 68
20819641 61
20823560 66
20900091 60
20900598 68
20901245 58
20901748 71
20902446 67
20902523 50
20904020 73
20904758 85
20905150 60
20905196 64
20905913 82
20908117 51
20909568 70
20913441 70
20924055 44
20924198 55
20601437 45
20609404 58
20618192 57
20712767 46
20720801 38
20800671 84
20800802 75
20801222 86
20801605 55
20801953 61
20802816 56
20802921 81
20805033 55
20810971 68
20813848 68
20819641 61
20823560 66
20900091 60
20900598 68
20901245 58
20901748 71
20902446 67
20902523 50
20904020 73
20904758 85
20905150 60
20905196 64
20905913 82
20908117 51
20909568 70
20913441 70
20924055 44
20924198 55
Monday, March 28, 2011
micro3 2nd theory test comments
Okay this is a work in progress; more comments will follow later.
You really need to read, understand the question and answer accordingly. As an example, question 2 asked for the method of the test used to determine if Corynebacterium diphtheriae produces a toxin. Why would you include the aim/purpose of the test in your
answer? It almost seems like you swotted the answer and then regurgitated it in the paper. Oh and another thing; it is VERY annoying to read through unnecessary stuff before 'finding' the answer I want. And why would you draw the plate? A total waste of time and effort. I didn't even look at it!!
You really need to read, understand the question and answer accordingly. As an example, question 2 asked for the method of the test used to determine if Corynebacterium diphtheriae produces a toxin. Why would you include the aim/purpose of the test in your
answer? It almost seems like you swotted the answer and then regurgitated it in the paper. Oh and another thing; it is VERY annoying to read through unnecessary stuff before 'finding' the answer I want. And why would you draw the plate? A total waste of time and effort. I didn't even look at it!!
Thursday, March 24, 2011
chempath tut6
1.1 A 22-year-old Librarian went to her family doctor as she noticed that her skin was becoming moist quite often. She was told by her colleagues that she should visit her doctor as her eyes seemed to have become more prominent and that she was losing weight. On examination her doctor noted that she had a slightly enlarged thyroid gland.
Blood tests showed the following:
TSH < 0.1 mU/L
fT4 33 pmol/l
fT3 8 pmol/l
The scan perform showed an enlarged gland. Autoantibodies to thyroid peroxidase and thyroglobulin were present in the serum in high titre.
Discuss the above case with possible diagnosis. [6]
1.2 Explain what is meant by negative feedback inhibition using thyroid hormone as an example. [6]
2. Write notes on:
2.1 Cortisol
2.2 Testosterone [10]
3. Explain the principle used in RAST technique. [5]
4. Assays in an Endocrinology Laboratory are subject to assay robustness. Heterophile antibodies and the ‘hook effect’ are just 2 examples that affect assays. Using a hormone as an example comment on these and discuss how they are overcome. [8]
5. hCG is now widely used as a tumour marker as well to check for pregnancy. Discuss the structure of the hormone and name the hormone to which it is similar.
Explain the various tests that are used for its detection.
[8]
6. Discuss congenital adrenal hyperplasia and the tests involved in its detection. [8]
7. What disease does the doctor suspect if there is elevated catecholeamines? Give special precautions (of the patient) prior to the test.
[5]
8. Describe 5 of the following immunochemical techniques:
8.1 Radial Immunodiffusion
8.2 Immunoelectrophoresis :
8.3 Isoelectric focusing (IEF)
8.4 Western blot
8.5 Laurell ‘Rocket’ immunoelectrophoresis
8.6 Immunonephelometry
[10]
9. What are the following acronyms (with regard to radioactivity)?
9.1 R
9.2 RAD
9.3 REM
[3]
10. Write short notes on waste disposal of radioactive material. [7]
Blood tests showed the following:
TSH < 0.1 mU/L
fT4 33 pmol/l
fT3 8 pmol/l
The scan perform showed an enlarged gland. Autoantibodies to thyroid peroxidase and thyroglobulin were present in the serum in high titre.
Discuss the above case with possible diagnosis. [6]
1.2 Explain what is meant by negative feedback inhibition using thyroid hormone as an example. [6]
2. Write notes on:
2.1 Cortisol
2.2 Testosterone [10]
3. Explain the principle used in RAST technique. [5]
4. Assays in an Endocrinology Laboratory are subject to assay robustness. Heterophile antibodies and the ‘hook effect’ are just 2 examples that affect assays. Using a hormone as an example comment on these and discuss how they are overcome. [8]
5. hCG is now widely used as a tumour marker as well to check for pregnancy. Discuss the structure of the hormone and name the hormone to which it is similar.
Explain the various tests that are used for its detection.
[8]
6. Discuss congenital adrenal hyperplasia and the tests involved in its detection. [8]
7. What disease does the doctor suspect if there is elevated catecholeamines? Give special precautions (of the patient) prior to the test.
[5]
8. Describe 5 of the following immunochemical techniques:
8.1 Radial Immunodiffusion
8.2 Immunoelectrophoresis :
8.3 Isoelectric focusing (IEF)
8.4 Western blot
8.5 Laurell ‘Rocket’ immunoelectrophoresis
8.6 Immunonephelometry
[10]
9. What are the following acronyms (with regard to radioactivity)?
9.1 R
9.2 RAD
9.3 REM
[3]
10. Write short notes on waste disposal of radioactive material. [7]
chempath tut5
1. Carol is a 28 – year – old woman, pregnant for the first time, presented at the emergency room in possible labour. She appeared anxious with a pregnancy of unknown duration. Her blood pressure was raised and appeared to gain weight in the last few weeks.
Results:
Blood: Sodium 135 mmol/l
Potassium 3.5 mmol/l
Chloride 100 mmol/l
CO2 25 mmol/l
Urea 2.8 mmol/l
Creatinine 74 umol/l
Urine: glucose + protein 3+
Amniotic fluid: L/S ratio 1.7 PG +
1.1 Judging from the results above, do they reflect a normal pregnancy?
1.2 Comment on the maturity of the foetus.
1.3 Briefly describe the testing for neural tube defect. [14]
2. There was much media speculation of meningitis in this country as many patients had
signs and symptoms of the condition and a few patients died from the illness.
2.1 Explain the collection of specimen of choice. [2]
2.2Discuss the various tubes taken and the reasons thereof. [4]
2.3 Name all the tests done in a Chemical Pathology lab for CSF analysis and
explain the significance of each test. [16]
4 3.1 In occult blood analysis discuss the interfering factors that give false
results. [2]
3.2 What are the limitations to the sensitivity and specificity of this assay? [2]
3.3 Explain the clinical usefulness of a faecal fat test. Note special requirements for the assay. [4]
3.4 Discuss the various methods employed for occult blood analysis. [6]
4.1 Certain requirements must be met for an enzyme to be suitable for EIA.
Discuss. [6]
4.2 Explain how immunonephelometry can be used to measure IgM. [6]
4.3 Differentiate between antigen and antibody detection using the sandwich technique. [6]
5. Dr Peter N is a pathologist who has completed the qualification as an endocrinologist. He wishes to leave the state hospital and open up a RIA laboratory. Name all the requirements that are necessary for this venture. [8]
Results:
Blood: Sodium 135 mmol/l
Potassium 3.5 mmol/l
Chloride 100 mmol/l
CO2 25 mmol/l
Urea 2.8 mmol/l
Creatinine 74 umol/l
Urine: glucose + protein 3+
Amniotic fluid: L/S ratio 1.7 PG +
1.1 Judging from the results above, do they reflect a normal pregnancy?
1.2 Comment on the maturity of the foetus.
1.3 Briefly describe the testing for neural tube defect. [14]
2. There was much media speculation of meningitis in this country as many patients had
signs and symptoms of the condition and a few patients died from the illness.
2.1 Explain the collection of specimen of choice. [2]
2.2Discuss the various tubes taken and the reasons thereof. [4]
2.3 Name all the tests done in a Chemical Pathology lab for CSF analysis and
explain the significance of each test. [16]
4 3.1 In occult blood analysis discuss the interfering factors that give false
results. [2]
3.2 What are the limitations to the sensitivity and specificity of this assay? [2]
3.3 Explain the clinical usefulness of a faecal fat test. Note special requirements for the assay. [4]
3.4 Discuss the various methods employed for occult blood analysis. [6]
4.1 Certain requirements must be met for an enzyme to be suitable for EIA.
Discuss. [6]
4.2 Explain how immunonephelometry can be used to measure IgM. [6]
4.3 Differentiate between antigen and antibody detection using the sandwich technique. [6]
5. Dr Peter N is a pathologist who has completed the qualification as an endocrinologist. He wishes to leave the state hospital and open up a RIA laboratory. Name all the requirements that are necessary for this venture. [8]
chempath tut4
1. Multiple choice: Choose the correct answer.
1.1 Characteristic X-rays are emitted during the nuclear reaction involving:
a. gamma decay
b. electron capture
c. positron decay
d. negatron decay
e. none of the above
1.2 In quantitative immunoassays the single most important factor responsible
for success or failure is:
a. affinity
b. titer
c. monoclonal property
d. antibody absorption
e. specificity
1.3 Which of the following compounds are often monitored by competitive
binding assays?
a. therapeutic drugs
b. protein hormones
c. estrogens
d. antibiotics
e. all of the above
1.4 Elevated T4 and T3 uptake together suggest the likelihood of :
a. hyperthyroidism
b. decreased TBG
c. hypothyroidism
d. decreased TSB
e. None of the above
1.5 TRH is secreted by the :
a. anterior pituitary
b. posterior pituitary
c. adrenal cortex
d. thyroid gland
e. hypothalamus
1.6 Steroid hormones are transported in blood :
a. Covalently bound to protein
b. Are free hormones
c. Non- covalently bound to specific proteins
d. In red blood cells
e. None of the above.
1.7 Which of the following describes the chemical characteristic of an antibody?
a. Carbohydrate
b. protein
c. lipid
d. electrolyte
e. ligand
1.8 Immunonephelometry is based upon the principle that :
a. antigen and antibody form small complexes in antibody excess
b. antigen and antibody form complexes in antigen excess
c. antigen and antibody react to form precipitin line
d. antigen and antibody form large complexes which precipitate
e. antigen and antibody form large lattice structures, which precipitate.
1.9 In double diffusion, immune precipitation reactions occur when two lines cross
each other: the reaction is one of:
a. antigen identity
b. identity
c. partial identity
d. non – identity
e. antibody identity
1.10 Which of the following factors affects antigenicity?
a. chemical nature
b. size
c. conformation
d. genetics
e. all are correct
[10]
2. Write an essay on the steps involved in the practical performance of RIA.
[12]
3. State whether the following statements are true or false. If false give an
explanation.
3.1 Steroid hormones are covalently bound to specific proteins and transported in blood.
3.2 When an antigen and antibody form small complexes in antigen excess, it is based on the principle of immunonephelometry.
3.3 Polyclonal antibodies are predominantly of the IgM type.
3.4 The posterior pituitary is also known as neurohypophysis
[6]
4. Certain requirements must be met for an enzyme to be suitable for EIA.
Discuss. [6]
5. Explain how immunonephelometry can be used to measure IgM. [6]
6. Explain what you would do if placed in the following situation:
Thembi is a patient whose blood sample was taken in the Endocrine clinic a month ago. She apparently phoned the clinic but was closed. Thus she called the laboratory for the result. You happen to answer the phone. You take her details and from the computer there was a TSH result of > 100 umol/l.
[2]
7. Draw a typical RIA graph for which a test like cortisol is plotted. [2]
8. Write short notes on waste disposal of radioactive material. [7]
9. What would the final dilution of serum be if 0.2ml was added to 39.8 ml of distilled water and then 1 ml of this was added to 7 mls of a reagent solution? [5]
10. Explain how you would prepare 40 ml of each of the following standards using a stock solution on 40g/l:
10.1 10 g/l
10.2 4 g/l [4]
1.1 Characteristic X-rays are emitted during the nuclear reaction involving:
a. gamma decay
b. electron capture
c. positron decay
d. negatron decay
e. none of the above
1.2 In quantitative immunoassays the single most important factor responsible
for success or failure is:
a. affinity
b. titer
c. monoclonal property
d. antibody absorption
e. specificity
1.3 Which of the following compounds are often monitored by competitive
binding assays?
a. therapeutic drugs
b. protein hormones
c. estrogens
d. antibiotics
e. all of the above
1.4 Elevated T4 and T3 uptake together suggest the likelihood of :
a. hyperthyroidism
b. decreased TBG
c. hypothyroidism
d. decreased TSB
e. None of the above
1.5 TRH is secreted by the :
a. anterior pituitary
b. posterior pituitary
c. adrenal cortex
d. thyroid gland
e. hypothalamus
1.6 Steroid hormones are transported in blood :
a. Covalently bound to protein
b. Are free hormones
c. Non- covalently bound to specific proteins
d. In red blood cells
e. None of the above.
1.7 Which of the following describes the chemical characteristic of an antibody?
a. Carbohydrate
b. protein
c. lipid
d. electrolyte
e. ligand
1.8 Immunonephelometry is based upon the principle that :
a. antigen and antibody form small complexes in antibody excess
b. antigen and antibody form complexes in antigen excess
c. antigen and antibody react to form precipitin line
d. antigen and antibody form large complexes which precipitate
e. antigen and antibody form large lattice structures, which precipitate.
1.9 In double diffusion, immune precipitation reactions occur when two lines cross
each other: the reaction is one of:
a. antigen identity
b. identity
c. partial identity
d. non – identity
e. antibody identity
1.10 Which of the following factors affects antigenicity?
a. chemical nature
b. size
c. conformation
d. genetics
e. all are correct
[10]
2. Write an essay on the steps involved in the practical performance of RIA.
[12]
3. State whether the following statements are true or false. If false give an
explanation.
3.1 Steroid hormones are covalently bound to specific proteins and transported in blood.
3.2 When an antigen and antibody form small complexes in antigen excess, it is based on the principle of immunonephelometry.
3.3 Polyclonal antibodies are predominantly of the IgM type.
3.4 The posterior pituitary is also known as neurohypophysis
[6]
4. Certain requirements must be met for an enzyme to be suitable for EIA.
Discuss. [6]
5. Explain how immunonephelometry can be used to measure IgM. [6]
6. Explain what you would do if placed in the following situation:
Thembi is a patient whose blood sample was taken in the Endocrine clinic a month ago. She apparently phoned the clinic but was closed. Thus she called the laboratory for the result. You happen to answer the phone. You take her details and from the computer there was a TSH result of > 100 umol/l.
[2]
7. Draw a typical RIA graph for which a test like cortisol is plotted. [2]
8. Write short notes on waste disposal of radioactive material. [7]
9. What would the final dilution of serum be if 0.2ml was added to 39.8 ml of distilled water and then 1 ml of this was added to 7 mls of a reagent solution? [5]
10. Explain how you would prepare 40 ml of each of the following standards using a stock solution on 40g/l:
10.1 10 g/l
10.2 4 g/l [4]
chempath tut3
1.1 Which of the following describes the chemical characteristic of an antibody?
a. carbohydrate
b. lipid
c. protein
d. electrolyte
e. ligand
1.2 Immunonephelometry is based upon the principle that :
a. antigen and antibody form complexes in antigen excess
b. antigen and antibody react to form precipitin line
c. antigen and antibody form small complexes in antibody excess
d. antigen and antibody form large complexes which precipitate
e. antigen and antibody form large lattice structures, which precipitate.
1.3 In double diffusion, immune precipitation reactions occur when two lines cross each other: the reaction is one of:
a. antigen identity
b. identity
c. partial identity
d. antibody identity
e. non – identity
1.4 Which of the following factors affects antigenicity?
a. chemical nature
b. size
c. conformation
d. genetics
e. all are correct
1.5 Laurell ‘ rocket’ immunoelectrophoresis requires :
a. agarose
b. purified antigen
c. ac power supply
d. agarose mixed with antibody
e. none are correct
Page 1 of 4
1.6 Which of the following compounds are not often monitored by competitive binding assays?
a. therapeutic drugs
b. protein hormones
c. estrogens
d. electrolytes
e. antibiotics
1.7 How much CaSO4 (Ca = 40; S = 32; O = 16) should be weighed to prepare one litre of a 0.5 M solution of CaSO4?:
a. 6.8 g
b. 13 g
c. 27.2 g
d. 34 g
e. 68 g
1.8 A tube contains the following:
Serum : 0.25 ml Saline : 0.75 ml Antigen : 1.0 ml
What is the serum dilution?
a. 1:2
b. 1:4
c. 1:7
d. 1:8
e. 1:16
1.9 How many ml of concentrated HCl (specific gravity = 1.2 ; 30 purity) would be needed to prepare one litre of a 4 M solution
( atomic weight H = 1 Cl = 35 )?:
a. 72 ml
b. 86.4 ml
c. 144 ml
d. 200 ml
e. 400 ml
Page 2 of 4
1.10 A crystal scintillation detector is primarily used for detecting radionuclides emitting:
a. positrons
b. gamma rays
c. negatrons
d. X – rays
e. Ultraviolet light
1.11 125I is used as a label because:
a. it has high specific activity
b. it is a high energy emitter
c. it has a long half-life
d. all of the above
e. none of the above.
[11]
2. Write an essay on the steps involved in the practical performance of RIA. Give a full explanation on each step i.e. reasons where possible. [12]
3. Explain the principle used in RAST technique. [4]
4. Describe 5 of the following immunochemical techniques:
4.1 Radial Immunodiffusion
4.2 Immunoelectrophoresis :
4.3 Isoelectric focusing ( IEF )
4.4 Western blot
4.5 Laurell ‘Rocket’ immunoelectrophoresis
4.6 Immunonephelometry
[10]
Page 3 of 4
5. Explain all the requirements for labels in immunoassays. [5]
6. Draw a typical RIA graph for which a test like cortisol is plotted.
[2]
7. Discuss how the entry of radioactivity may be prevented. [6]
8. What are the following acronyms (with regard to radioactivity)?:
8.1 R
8.2 RAD
8.3 REM
[3]
9. Write short notes on waste disposal of radioactive material. [7]
a. carbohydrate
b. lipid
c. protein
d. electrolyte
e. ligand
1.2 Immunonephelometry is based upon the principle that :
a. antigen and antibody form complexes in antigen excess
b. antigen and antibody react to form precipitin line
c. antigen and antibody form small complexes in antibody excess
d. antigen and antibody form large complexes which precipitate
e. antigen and antibody form large lattice structures, which precipitate.
1.3 In double diffusion, immune precipitation reactions occur when two lines cross each other: the reaction is one of:
a. antigen identity
b. identity
c. partial identity
d. antibody identity
e. non – identity
1.4 Which of the following factors affects antigenicity?
a. chemical nature
b. size
c. conformation
d. genetics
e. all are correct
1.5 Laurell ‘ rocket’ immunoelectrophoresis requires :
a. agarose
b. purified antigen
c. ac power supply
d. agarose mixed with antibody
e. none are correct
Page 1 of 4
1.6 Which of the following compounds are not often monitored by competitive binding assays?
a. therapeutic drugs
b. protein hormones
c. estrogens
d. electrolytes
e. antibiotics
1.7 How much CaSO4 (Ca = 40; S = 32; O = 16) should be weighed to prepare one litre of a 0.5 M solution of CaSO4?:
a. 6.8 g
b. 13 g
c. 27.2 g
d. 34 g
e. 68 g
1.8 A tube contains the following:
Serum : 0.25 ml Saline : 0.75 ml Antigen : 1.0 ml
What is the serum dilution?
a. 1:2
b. 1:4
c. 1:7
d. 1:8
e. 1:16
1.9 How many ml of concentrated HCl (specific gravity = 1.2 ; 30 purity) would be needed to prepare one litre of a 4 M solution
( atomic weight H = 1 Cl = 35 )?:
a. 72 ml
b. 86.4 ml
c. 144 ml
d. 200 ml
e. 400 ml
Page 2 of 4
1.10 A crystal scintillation detector is primarily used for detecting radionuclides emitting:
a. positrons
b. gamma rays
c. negatrons
d. X – rays
e. Ultraviolet light
1.11 125I is used as a label because:
a. it has high specific activity
b. it is a high energy emitter
c. it has a long half-life
d. all of the above
e. none of the above.
[11]
2. Write an essay on the steps involved in the practical performance of RIA. Give a full explanation on each step i.e. reasons where possible. [12]
3. Explain the principle used in RAST technique. [4]
4. Describe 5 of the following immunochemical techniques:
4.1 Radial Immunodiffusion
4.2 Immunoelectrophoresis :
4.3 Isoelectric focusing ( IEF )
4.4 Western blot
4.5 Laurell ‘Rocket’ immunoelectrophoresis
4.6 Immunonephelometry
[10]
Page 3 of 4
5. Explain all the requirements for labels in immunoassays. [5]
6. Draw a typical RIA graph for which a test like cortisol is plotted.
[2]
7. Discuss how the entry of radioactivity may be prevented. [6]
8. What are the following acronyms (with regard to radioactivity)?:
8.1 R
8.2 RAD
8.3 REM
[3]
9. Write short notes on waste disposal of radioactive material. [7]
chempath tut2
1.1 How many milliliters of concentrated HNO3 (sp gravity 1.42 g/ml; assay =
85%) are required to prepare 5 litres of 0.5 NO3? [5]
1.2 What amount of NaOH is required to obtain 100 mg of Na? [4]
2. Explain the following statements:
2.1 Foreign antigens and antisera may leave little permanent damage.
2.2 Labels must not be present in body fluids in high concentration.
2.3 The lab may required samples taken from animals.
2.4 The thyroid gland is one organ that is often neglected and is an essential in its numerous functions
2.5 A overproduction of VMA / HMA may be precipitated by tumors [5]
3. Discuss 4 of the listed techniques / assays that may be encountered in immunoassays. Provide full names.
3.1 ELISA
3.2 IRMA
3.3 EMIT
3.4 SLFIA
3.5 FPIA [10]
4. Using GH (Growth hormone) as an example explain the concept of competitive binding. Draw various diagrams to depict various levels of GH.
[15]
5. Discuss the concept of chemiluminescence. Explain the origin and how it may
be eliminated. [3]
6. If you were to establish a lab for RIA state all the necessary precautions you would take to ensure you would obtain the specified license to practice. [7]
7. Catherine is a librarian who went to her GP as she was not her usual self for a number of months. Her weight deteriorated and her eyes began bulging. On examination, her doctor observed that she had a slightly enlarged thyroid gland.
Blood tests showed the following:
TSH < 0.1 mU/L
fT4 33 pmol/l
fT3 12 pmol/l
7.1 Discuss the above case with possible diagnosis. [6]
7.2 Give the possible treatment [1]
8. Castor Semenya made the headlines last year and later the topic was very sensitive due to its very nature. Explain the concept from a molecular level and its implications. [6]
9.1 Differentiate between the drug chemical name, generic and trade name. Give an example [6]
9.2 Briefly explain all the factors which may affect drug level assays and interpretation [7]
85%) are required to prepare 5 litres of 0.5 NO3? [5]
1.2 What amount of NaOH is required to obtain 100 mg of Na? [4]
2. Explain the following statements:
2.1 Foreign antigens and antisera may leave little permanent damage.
2.2 Labels must not be present in body fluids in high concentration.
2.3 The lab may required samples taken from animals.
2.4 The thyroid gland is one organ that is often neglected and is an essential in its numerous functions
2.5 A overproduction of VMA / HMA may be precipitated by tumors [5]
3. Discuss 4 of the listed techniques / assays that may be encountered in immunoassays. Provide full names.
3.1 ELISA
3.2 IRMA
3.3 EMIT
3.4 SLFIA
3.5 FPIA [10]
4. Using GH (Growth hormone) as an example explain the concept of competitive binding. Draw various diagrams to depict various levels of GH.
[15]
5. Discuss the concept of chemiluminescence. Explain the origin and how it may
be eliminated. [3]
6. If you were to establish a lab for RIA state all the necessary precautions you would take to ensure you would obtain the specified license to practice. [7]
7. Catherine is a librarian who went to her GP as she was not her usual self for a number of months. Her weight deteriorated and her eyes began bulging. On examination, her doctor observed that she had a slightly enlarged thyroid gland.
Blood tests showed the following:
TSH < 0.1 mU/L
fT4 33 pmol/l
fT3 12 pmol/l
7.1 Discuss the above case with possible diagnosis. [6]
7.2 Give the possible treatment [1]
8. Castor Semenya made the headlines last year and later the topic was very sensitive due to its very nature. Explain the concept from a molecular level and its implications. [6]
9.1 Differentiate between the drug chemical name, generic and trade name. Give an example [6]
9.2 Briefly explain all the factors which may affect drug level assays and interpretation [7]
chempath tut1
1. Multiple choice: choose the correct answer; showing how you obtained
your answer.
1.1 What is the molarity of a solution that contains 18.7g of KCl in
500 ml?
A. 0.1
B. 0.5
C. 1.0
D. 5.0
1.2 How much 95% alcohol is required to prepare 5 L 70% alcohol?
A. 2.4 L
B 3.5 L
C. 3.7 L
D. 4.4 L
1.3. How many milliliters of concentrated H2SO4 are required to prepare 10L of 0.1 N H2SO4?
A. 1.84
B. 9.20
C. 27.5
D. 54.4
1.4 How many grams of Na0H are required to prepare 2500 mL of a 4 M solution?]
A. 40
B. 100
C. 160
D. 400
1.5 What is the relative centrifugal force of a centrifuge operating at 1500 rpm with a radius of 10 cm?
A. 625
B. 699
C. 252
D. 6988
1.6 Which of the following weighs the most?
A. 0.1 ng
B. 0.01 g
C. 1.0 mg
D. 1000 pg
1.7 What amount of NaCl is needed to obtain 50 mg Cl?
A. 19.6 mg
B. 30.3 mg
C. 50.0 mg
D. 82.4 mg [7 x 3 = 21]
2.1 Explain the term occult blood, with details of the type of specimen
required for analysis. [3]
2.2 Give 3 cases where one can get a positive result. [3]
2.3 Explain how one can obtain a false positive result. [1]
2.4 Name a type of occult blood test that may be obtained from suppliers / manufacturers. [1]
3. Discuss the assessment of foetal maturity and reasons why amniotic fluid is a choice of specimen for analysis. [5]
4. Differentiate between antigen and antibody detection using the sandwich technique. [6]
5. Dr Peter N is a Pathologist who has completed the qualification as an endocrinologist. He wishes to leave the state hospital and open up a RIA laboratory. Name all the requirements that are necessary for this venture. [8]
6. Draw a fully labelled diagram to illustrate a competitive binding assay. [5]
7. With the aid of separate diagrams show how standard curves are generated in a radioimmunoassay and also how patients’ results are obtained from the graph. [12]
8. Explain counting and maintaining consistency in RIA measurements. [6]
9. Describe 5 of the following immunochemical techniques:
9.1 Radial Immunodiffusion
9.2 Immunoelectrophoresis
9.3 Isoelectric focusing ( IEF )
9.4 Western blot
9.5 Laurell ‘Rocket’ immunoelectrophoresis
9.6 Immunonephelometry
[10]
Additional information:
Molar mass:
K 39 Cl 35.5 H 1 S 32 O 16 Na 23
H2SO4 (sp gr = 1.84g/mL; assay = 97%)
your answer.
1.1 What is the molarity of a solution that contains 18.7g of KCl in
500 ml?
A. 0.1
B. 0.5
C. 1.0
D. 5.0
1.2 How much 95% alcohol is required to prepare 5 L 70% alcohol?
A. 2.4 L
B 3.5 L
C. 3.7 L
D. 4.4 L
1.3. How many milliliters of concentrated H2SO4 are required to prepare 10L of 0.1 N H2SO4?
A. 1.84
B. 9.20
C. 27.5
D. 54.4
1.4 How many grams of Na0H are required to prepare 2500 mL of a 4 M solution?]
A. 40
B. 100
C. 160
D. 400
1.5 What is the relative centrifugal force of a centrifuge operating at 1500 rpm with a radius of 10 cm?
A. 625
B. 699
C. 252
D. 6988
1.6 Which of the following weighs the most?
A. 0.1 ng
B. 0.01 g
C. 1.0 mg
D. 1000 pg
1.7 What amount of NaCl is needed to obtain 50 mg Cl?
A. 19.6 mg
B. 30.3 mg
C. 50.0 mg
D. 82.4 mg [7 x 3 = 21]
2.1 Explain the term occult blood, with details of the type of specimen
required for analysis. [3]
2.2 Give 3 cases where one can get a positive result. [3]
2.3 Explain how one can obtain a false positive result. [1]
2.4 Name a type of occult blood test that may be obtained from suppliers / manufacturers. [1]
3. Discuss the assessment of foetal maturity and reasons why amniotic fluid is a choice of specimen for analysis. [5]
4. Differentiate between antigen and antibody detection using the sandwich technique. [6]
5. Dr Peter N is a Pathologist who has completed the qualification as an endocrinologist. He wishes to leave the state hospital and open up a RIA laboratory. Name all the requirements that are necessary for this venture. [8]
6. Draw a fully labelled diagram to illustrate a competitive binding assay. [5]
7. With the aid of separate diagrams show how standard curves are generated in a radioimmunoassay and also how patients’ results are obtained from the graph. [12]
8. Explain counting and maintaining consistency in RIA measurements. [6]
9. Describe 5 of the following immunochemical techniques:
9.1 Radial Immunodiffusion
9.2 Immunoelectrophoresis
9.3 Isoelectric focusing ( IEF )
9.4 Western blot
9.5 Laurell ‘Rocket’ immunoelectrophoresis
9.6 Immunonephelometry
[10]
Additional information:
Molar mass:
K 39 Cl 35.5 H 1 S 32 O 16 Na 23
H2SO4 (sp gr = 1.84g/mL; assay = 97%)
Tuesday, March 22, 2011
stormy clot
This is one of the tests done to identify Clostridium perfringens. A litmus milk is used. Litmus milk is a light purple liquid aliquoted in a bijou bottle. Prior to us for THIS test, sterile rusty nails are put into it. Sterile so that it is not contaminated. Rusty nails so that an anaerobic atmosphere is created. Remember that Clostridium is an aerotolerant anaerobe, i.e. it will not die on exposure to oxygen.
Inoculate the litmus milk with the test organism. Incubate anaerobically at 37 degrees for 18-24 hours. You can use a candle jar.
After incubation, examine for the presence of a stormy clot. I will first describe how the stormy clot is formed, and then describe its appearance.
Lactose in the milk is fermented. Acid and gas are produced. This acid causes coagulation of the casein. Casein combines with the gas to produce the distinctive and characteristic stormy clot.
A stormy clot is the production of whitish cloud like coagulation at the top of the litmus milk. Below that is the paler litmus milk. It is almost like the clouds we see at dusk, large white cumulonimbus clouds above a very pretty pale blue sky.
Inoculate the litmus milk with the test organism. Incubate anaerobically at 37 degrees for 18-24 hours. You can use a candle jar.
After incubation, examine for the presence of a stormy clot. I will first describe how the stormy clot is formed, and then describe its appearance.
Lactose in the milk is fermented. Acid and gas are produced. This acid causes coagulation of the casein. Casein combines with the gas to produce the distinctive and characteristic stormy clot.
A stormy clot is the production of whitish cloud like coagulation at the top of the litmus milk. Below that is the paler litmus milk. It is almost like the clouds we see at dusk, large white cumulonimbus clouds above a very pretty pale blue sky.
comments on micro3 practical test one
I can't decide if I am amused or upset about the stuff you did in your prac test. These are some comments I noted:
Many organisms can grow on SAB. You cannot assume that if there is growth, that it is definitely a yeast
Biochemical tests that you set up must tie in with what you observed in your Gram stain
I have asked repeatedly that you do not describe the colour of the colonies or organisms. It is either Gram positive or negative, or LF or NLF
You need to interpret the results of the biochemical tests as being either positive or negative. At this stage of your studies, you should not be saying/describing the colours seen
MSA cannot be positive or negative. You need to state mannitol fermentation or no mannitol fermentation
LF on MacConkey are large glossy mucoid colonies
Escherichia coli 0157H7 can only be determined by serotyping the E coli. It is not determined by putting up sugars
CTA sugars are not used for GNB identification.
Above all else, please listen to me in lectures, during practical sessions, etc. I am not wasting your time by telling you stuff.
Many organisms can grow on SAB. You cannot assume that if there is growth, that it is definitely a yeast
Biochemical tests that you set up must tie in with what you observed in your Gram stain
I have asked repeatedly that you do not describe the colour of the colonies or organisms. It is either Gram positive or negative, or LF or NLF
You need to interpret the results of the biochemical tests as being either positive or negative. At this stage of your studies, you should not be saying/describing the colours seen
MSA cannot be positive or negative. You need to state mannitol fermentation or no mannitol fermentation
LF on MacConkey are large glossy mucoid colonies
Escherichia coli 0157H7 can only be determined by serotyping the E coli. It is not determined by putting up sugars
CTA sugars are not used for GNB identification.
Above all else, please listen to me in lectures, during practical sessions, etc. I am not wasting your time by telling you stuff.
Wednesday, March 16, 2011
to think about 2 ............
In blood culturing, the machine alerts us when the level of carbon dioxide increases. This indicates that there is most probably multiplication of micro organisms in a particular blood culture bottle.
Suppose the patient's specimen revealed scanty GPC in chains.
Could you offer a reason why a Gram done on the blood culture bottle may show no organisms. Even though the machine sounded an alert.
The acid fast smear shows AFB. Growth on selective agar is negative after 6 weeks.
Suggest a few reasons why this may be.
Suppose the patient's specimen revealed scanty GPC in chains.
Could you offer a reason why a Gram done on the blood culture bottle may show no organisms. Even though the machine sounded an alert.
The acid fast smear shows AFB. Growth on selective agar is negative after 6 weeks.
Suggest a few reasons why this may be.
ELEK test
This test is done to determine if an already isolated and identified Corynebacterium diphtheriae produces toxins.The plate comprises molten agar, rabbit serum (for enrichment) and potassium tellurite. Place a filter paper strip impregnated with antitoxin across the middle of the plate. Allow the filter paper to sink to the bottom of the plate. Let the plate solidify and ensure that it is dry before use.
All inoculations are done at right angles to the long edge of the filter paper. All inoculations are done parallel to each other. Finally ensure that the test organism is next to the positive control. The inoculations are line streaks.
After incubation (18-24 hours at 37 degrees) examine the plate for white lines of precipitation that extend outwards from the line of inoculation/bacterial growth at an angle of 45 degrees. If you inoculated the test next to the positive control, and if the test is positive, you will see a wave like formation.
All inoculations are done at right angles to the long edge of the filter paper. All inoculations are done parallel to each other. Finally ensure that the test organism is next to the positive control. The inoculations are line streaks.
After incubation (18-24 hours at 37 degrees) examine the plate for white lines of precipitation that extend outwards from the line of inoculation/bacterial growth at an angle of 45 degrees. If you inoculated the test next to the positive control, and if the test is positive, you will see a wave like formation.
Nagler plate
This is a test done to determine if Clostridium perfringens produces lecithinase, a toxin.
The agar plate is egg based which provides the lecithin. Its colour is similar to a nutrient agar plate. These plates dont have a long shelf life so are either made up in small quantities of made when required. the plates need to be sealed in plastic bags and refridgerated prior to use. Allow plates to reach room temperature before use.
divide the plate in half using a permanent marker. Name one half as the seeded portion. Seed that half with the lecithinase.
Streak your test organism, positive and negative controls perpendicular to the dividing line, parallel to each other, using a line streak. Ensure that you start streaking from the unseeded half to the seeded half. This is so that no lecithinase is carried over to the unseeded half.
Incubate the plates anaerobically for 18-24 hours at 37 degrees.
When lecithin combines with lecithinase, it produces opalescence, which has a cloudy, milky, opal looking effect. Therefore a positive reaction would be opalescence on the unseeded half, and no opalescence on the seeded half. Very pretty!!in the seeded half, the lecinthinase is neutralised by the antitoxin, thats why no opalescence is seen.
Ensure that before reading your test you read the positive and negative controls.
The agar plate is egg based which provides the lecithin. Its colour is similar to a nutrient agar plate. These plates dont have a long shelf life so are either made up in small quantities of made when required. the plates need to be sealed in plastic bags and refridgerated prior to use. Allow plates to reach room temperature before use.
divide the plate in half using a permanent marker. Name one half as the seeded portion. Seed that half with the lecithinase.
Streak your test organism, positive and negative controls perpendicular to the dividing line, parallel to each other, using a line streak. Ensure that you start streaking from the unseeded half to the seeded half. This is so that no lecithinase is carried over to the unseeded half.
Incubate the plates anaerobically for 18-24 hours at 37 degrees.
When lecithin combines with lecithinase, it produces opalescence, which has a cloudy, milky, opal looking effect. Therefore a positive reaction would be opalescence on the unseeded half, and no opalescence on the seeded half. Very pretty!!in the seeded half, the lecinthinase is neutralised by the antitoxin, thats why no opalescence is seen.
Ensure that before reading your test you read the positive and negative controls.
Monday, March 14, 2011
foundation immunology theory test 1 comments
Hi. These are some comments that i feel compelled to make after marking your scripts and reviewing your answers.
The test comprised just 5 questions. Yes I concede that the question on Ab structure was trickery but that was done deliberately to test your knowledge. You were/are supposed to be aware of the fact that IgM is a pentamer. When I questioned you in class during the practical session, you all agreed that you knew this. But knowing this fact and applying it are two different things.
Question 4 was done very poorly. I really emphasized in class that cells express cell markers. CD1 is a maturation marker and is only expressed by thymocytes. Thymocytes are immature T cells found only in the thymus. Thats 2 marks out of 5. The remaining 3 marks comes from stating that CD25 is only expressed by an activated/stimulated cell; a thymocyte can never be stimulated; therefore the thymocyte can never express CD25.
Your answers told me lots of things. It spoke about cell markers expressing cell markers. It spoke about maturation and lineage markers. But your answers could not make the jump from the theory to the explanation required of you.
Now I believe that many of you are using the same old method of studying that you used last semester and last year, i.e. memorising. I need to tell you that memorising will not work in Immunology. You have to apply your knowledge. Unless you are prepared to change, and unless you do change, you will have a problem in performing well in any assessment.
Please do come see me for any help that I can offer.
The test comprised just 5 questions. Yes I concede that the question on Ab structure was trickery but that was done deliberately to test your knowledge. You were/are supposed to be aware of the fact that IgM is a pentamer. When I questioned you in class during the practical session, you all agreed that you knew this. But knowing this fact and applying it are two different things.
Question 4 was done very poorly. I really emphasized in class that cells express cell markers. CD1 is a maturation marker and is only expressed by thymocytes. Thymocytes are immature T cells found only in the thymus. Thats 2 marks out of 5. The remaining 3 marks comes from stating that CD25 is only expressed by an activated/stimulated cell; a thymocyte can never be stimulated; therefore the thymocyte can never express CD25.
Your answers told me lots of things. It spoke about cell markers expressing cell markers. It spoke about maturation and lineage markers. But your answers could not make the jump from the theory to the explanation required of you.
Now I believe that many of you are using the same old method of studying that you used last semester and last year, i.e. memorising. I need to tell you that memorising will not work in Immunology. You have to apply your knowledge. Unless you are prepared to change, and unless you do change, you will have a problem in performing well in any assessment.
Please do come see me for any help that I can offer.
Monday, March 7, 2011
Foundation Immunology tutorials
I have been asked to post the answers to the tut I have given you. The problem with that, is that you will learn the answers and not know how to approach answering these type of questions. Ideally you should be working out the answers, asking me to have a look at it, and then I would help you in knowing how to approach answering the questions. So I am very hesitant in posting answers.
What I will do, is guide you, on how to attempt the questions, and hopefully, help you understand the questions asked. So here goes:
1. Write 2 sentences to show the relationship between TC, CD4, CD8, MHC class II and APC.
NB! Some components are missing
Your answer should include ONLY 2 sentences, and each sentence should explain one relationship. Remember that cells express cell markers, and that cell markers interact with each other. So your answer should go something like this: ---- cell expressing -------- interacts with ------- expressed by -------
Then blanks will either be the cell type of the cell marker.
You already know that Tc expresses CD8, TH expresses CD4, MHC class II is expressed by APC’s and that MHC class I is expressed by nucleated cells.
So your final answer should be:
TC expressing CD8 interacts with MHC class I expressed by nucleated cells
And vice versa……
2. Supply immunologically sound reasons why booster shots of vaccines are necessary.
This questions relates indirectly to the differences between the primary and secondary IR.
Now booster shots of vaccines are the second and subsequent doses of vaccines. We all know that most vaccines are given more than once. A classic example is measles.
A vaccine is an altered version of the antigen that remains antigenic but is no longer pathogenic. So when it is given twice, it will induce a secondary IR. We know that more Ab are produced in the secondary IR and the Ab produced have a greater affinity. Surely these are good attributes to have. Yes indeed, I want those AB!!!
These are the only questions I expect you to have a problem with. Please see me if you need further help.
What I will do, is guide you, on how to attempt the questions, and hopefully, help you understand the questions asked. So here goes:
1. Write 2 sentences to show the relationship between TC, CD4, CD8, MHC class II and APC.
NB! Some components are missing
Your answer should include ONLY 2 sentences, and each sentence should explain one relationship. Remember that cells express cell markers, and that cell markers interact with each other. So your answer should go something like this: ---- cell expressing -------- interacts with ------- expressed by -------
Then blanks will either be the cell type of the cell marker.
You already know that Tc expresses CD8, TH expresses CD4, MHC class II is expressed by APC’s and that MHC class I is expressed by nucleated cells.
So your final answer should be:
TC expressing CD8 interacts with MHC class I expressed by nucleated cells
And vice versa……
2. Supply immunologically sound reasons why booster shots of vaccines are necessary.
This questions relates indirectly to the differences between the primary and secondary IR.
Now booster shots of vaccines are the second and subsequent doses of vaccines. We all know that most vaccines are given more than once. A classic example is measles.
A vaccine is an altered version of the antigen that remains antigenic but is no longer pathogenic. So when it is given twice, it will induce a secondary IR. We know that more Ab are produced in the secondary IR and the Ab produced have a greater affinity. Surely these are good attributes to have. Yes indeed, I want those AB!!!
These are the only questions I expect you to have a problem with. Please see me if you need further help.
Friday, March 4, 2011
micro3 tut answers
CTA sugars Neisseria
Bulls eye colonies Yersinia enterocolitica
CNA agar Staphylococcus
Sorbitol MacConkey E coli 0157H7
Alkaline peptone water Vibrio
Red colonies with black centres Salmonella
Coag neg MSA neg DNAse neg novobiocin R S saprophyticus
Kauffman White scheme Salmonella
Lancefield grouping Streptococcus
Impetigo S aureus
Bacitracin R halophile S aureus
MRSA S aureus
CAMP reaction with arrowhead haemolysis S agalactiae
Bacitracin S, Beta haemolytic GPC S pyogenes
Draughtsman colonies S pneumoniae
Increased haemolysis in CO2 Streptococcus
R to trimeth and sulphamethoxazole S pyogenes
GN diplococcic Neisseria
Opthalmia neonatorium N gonorrhoeae
Kidney shaped IC to neutrophils Neisseria
Growth on BA/CHOC at room temp, and NA at 37 degrees Non pathogenic Neisseria, i.e. commensals
Anorectal, conjunctival and oropharyngeal specimens N gonorrhoeae
MTM agar Neisseria
NYC agar Neisseria
HUS E coli 0157H7 or EHEC
CIN agar Y enterocolitica
Non motile at 37, motile at room temp Yesrsinia except pestis
Bulls eye colonies Yersinia enterocolitica
CNA agar Staphylococcus
Sorbitol MacConkey E coli 0157H7
Alkaline peptone water Vibrio
Red colonies with black centres Salmonella
Coag neg MSA neg DNAse neg novobiocin R S saprophyticus
Kauffman White scheme Salmonella
Lancefield grouping Streptococcus
Impetigo S aureus
Bacitracin R halophile S aureus
MRSA S aureus
CAMP reaction with arrowhead haemolysis S agalactiae
Bacitracin S, Beta haemolytic GPC S pyogenes
Draughtsman colonies S pneumoniae
Increased haemolysis in CO2 Streptococcus
R to trimeth and sulphamethoxazole S pyogenes
GN diplococcic Neisseria
Opthalmia neonatorium N gonorrhoeae
Kidney shaped IC to neutrophils Neisseria
Growth on BA/CHOC at room temp, and NA at 37 degrees Non pathogenic Neisseria, i.e. commensals
Anorectal, conjunctival and oropharyngeal specimens N gonorrhoeae
MTM agar Neisseria
NYC agar Neisseria
HUS E coli 0157H7 or EHEC
CIN agar Y enterocolitica
Non motile at 37, motile at room temp Yesrsinia except pestis
Thursday, March 3, 2011
haemolytic disease of the newborn (HDN)
This is a disease of the newborn characterised by massive intravascular and extravascular lysis of red blood cells due to a Rhesus incompatibility.
This is what happens in HDN:
PS Please read Rhesus typing first, in order to appreciate this
a mom is Rhesus negative, pregnant with a baby from a Rhesus positive father. In most cases the baby will be Rhesus positive.
The situation i am going to describe is what happens in a normal pregnancy, no trauma, no placenta abruptio, etc
The mom's blood circulates through the baby, and never vice versa
So the D antigen in the baby never comes into contact with the mom'c immune system.
During delivery, when the placenta breaks, there is mixing of the baby's and mom's blood. D from the baby comes into contact with the mom's immune system and she, naturally, produces anti D.
If, at this stage, nothing is done, the antiD will remain in the mom, quietly waiting.....
In the next pregnancy from the same father, mom's blood is circulating through the baby. AntiD from the mom will now agglutinate the D of/in the baby, leading to HDN.
Can you imagine the consequences of this.....this tiny little baby, still in utero, having all or almost all its RBC haemolysed? so is there no hope for little Keith??????
weel if this situation was allowed to develop, doctors can do an exchange transfusion either in utero or after the baby is born. Basically quite dangerous but there have been some successes. The baby's blood is removed, a little at a time, and fresh blood from a donor is transfused into the baby. All sorts of possible transfusion reactions , but that will keep for another post. Ta Ta
This is what happens in HDN:
PS Please read Rhesus typing first, in order to appreciate this
a mom is Rhesus negative, pregnant with a baby from a Rhesus positive father. In most cases the baby will be Rhesus positive.
The situation i am going to describe is what happens in a normal pregnancy, no trauma, no placenta abruptio, etc
The mom's blood circulates through the baby, and never vice versa
So the D antigen in the baby never comes into contact with the mom'c immune system.
During delivery, when the placenta breaks, there is mixing of the baby's and mom's blood. D from the baby comes into contact with the mom's immune system and she, naturally, produces anti D.
If, at this stage, nothing is done, the antiD will remain in the mom, quietly waiting.....
In the next pregnancy from the same father, mom's blood is circulating through the baby. AntiD from the mom will now agglutinate the D of/in the baby, leading to HDN.
Can you imagine the consequences of this.....this tiny little baby, still in utero, having all or almost all its RBC haemolysed? so is there no hope for little Keith??????
weel if this situation was allowed to develop, doctors can do an exchange transfusion either in utero or after the baby is born. Basically quite dangerous but there have been some successes. The baby's blood is removed, a little at a time, and fresh blood from a donor is transfused into the baby. All sorts of possible transfusion reactions , but that will keep for another post. Ta Ta
Chempath test 3
1. Multiple choice: Choose the correct answer; showing how you obtained your answer
1.1 What is the molarity of a solution that contains 18.7g of KCl in 500 ml?
0.1
0.5
1.0
5.0
1.2 How much 95% alcohol is required to prepare 5 L 70% alcohol?
A. 2.4 L
B 3.5 L
3.7 L
4.4 L
How many milliliters of concentrated H2SO4 (100%) are required to prepare 10L of 0.1 M H2SO4?
A. 1.84
9.20
27.5
54.9
In a spectrophotometric procedure that follows Beer’s law, the absorbance of a standard solution of concentration 15 g/L is 0.50 in a 1 cm cell. The absorbance of the sample solution is 0.62. What is the concentration?
0.62 g/L
6.2 mol/L
12.1 g/L
18.6 g/L
1.5 How many grams of Na0H are required to prepare 2500 mL of a 4 M solution?
40
100
160
400
1.6 An isotonic saline solution contains 0.85% NaCl. How many grams of
NaCl are needed to 5 L of this solution?
4.25
8.5
42.5
170
How many milliliters of concentrated HN03 are required to prepare 2 L of 0.15 N HN03?
13.3
19.0
38.0
189.9
An analysis for sodium is performed on an aliquot of a 24- hour urine specimen. A sodium value of 122.5 mmol/l is read from the instrument. What is the amount of sodium in the 24hr urine specimen if 1540 mL of urine are collected?
79.5
188.6
1886.5
18,865
8 x 2 = 16
Additional information: Molar mass:
K 39 Cl 35.5 H 1 S 32 O 16 N 14 Na 23 C 12
2. Grace, a 49 year-old woman was admitted to the Inkosi Albert Luthuli Central Hospital for cataract extraction. Her eyesight was deteriorating but otherwise she was in good health. In 1990 Grace had undergone thyroidectomy for a multinodular goiter. Routine investigations were carried out using a blood sample from the patient.
Tests
Serum
Calcium 1.66 mmol/l
Phosphate 2.65 mmo/l
Albumin 42 g/l
Alkaline phosphatase 65 IU/L
2.1 Comment on the results. [6]
2.2 What was the main clue for the diagnosis apart from the patient’s results? [1]
3. After a phosphorous analysis using the molybdate method without a reducing agent, the following absorbance readings were obtained:-
Standard (1.6 mmol/l) 0.414
Standard 0.418
Normal control 0.380
Serum A 0.678
Serum B 0.350
Urine sample C (diluted 1 in 5) 0.204
(Volume 1567)
Calculate the phosphorus concentration for all specimens/controls.
If the mean target value for the normal control is 1.41 mmol/l and the SD is 0.10; is your batch of results within acceptable limits?
Which of the two serum samples gives an abnormal result? Can you give a possible cause for it?
Describe the principle of the method used.
Discuss all the precautions that must be taken when a serum sample is taken for phosphate determination. [20]
4. A 50-year-old man presented with weight loss and weakness. The time of the year was winter but his skin was noticeably bronzed. On examination, he was found to have hepatosplenomegaly.
Investigations
Urine positive for glucose
Blood sugar 12 mmol/l
Serum
Iron 58 µmol/l
Transferrin 2.15 g/l
Ferritin 3500 µg/ml
4.1 Predict the diagnosis of the patient. Justify your answer with explanations and show calculations. [8]
5. Provide an explanation / reasons for the following:
Tumor markers are processed in a batch.
Two – way traffic of samples and reports.
Receptions area should be free of clutter.
Bulk of the work is done in the first shift.
Transcription mistakes are not allowed.
[10]
6. Complete the following table.
Laboratory markers of iron status in Disease States
Conditions Serum Iron Transferrin Ferritin % Saturation
Malnutrition 6.1 Variable
Malignancy 6.2
Chronic infection 6.3
Viral hepatitis 6.4
Anaemia of chronic disease 6.5 Normal/
Sideroblastic anaemia Normal / 6.6
Iron deficiency 6.7 6.8
Iron poisoning / overdose 6.9
Haematochromatosis 6.10
[10]
7. Make recommendations of how space could be best utilized when designing a laboratory.
[4]
1.1 What is the molarity of a solution that contains 18.7g of KCl in 500 ml?
0.1
0.5
1.0
5.0
1.2 How much 95% alcohol is required to prepare 5 L 70% alcohol?
A. 2.4 L
B 3.5 L
3.7 L
4.4 L
How many milliliters of concentrated H2SO4 (100%) are required to prepare 10L of 0.1 M H2SO4?
A. 1.84
9.20
27.5
54.9
In a spectrophotometric procedure that follows Beer’s law, the absorbance of a standard solution of concentration 15 g/L is 0.50 in a 1 cm cell. The absorbance of the sample solution is 0.62. What is the concentration?
0.62 g/L
6.2 mol/L
12.1 g/L
18.6 g/L
1.5 How many grams of Na0H are required to prepare 2500 mL of a 4 M solution?
40
100
160
400
1.6 An isotonic saline solution contains 0.85% NaCl. How many grams of
NaCl are needed to 5 L of this solution?
4.25
8.5
42.5
170
How many milliliters of concentrated HN03 are required to prepare 2 L of 0.15 N HN03?
13.3
19.0
38.0
189.9
An analysis for sodium is performed on an aliquot of a 24- hour urine specimen. A sodium value of 122.5 mmol/l is read from the instrument. What is the amount of sodium in the 24hr urine specimen if 1540 mL of urine are collected?
79.5
188.6
1886.5
18,865
8 x 2 = 16
Additional information: Molar mass:
K 39 Cl 35.5 H 1 S 32 O 16 N 14 Na 23 C 12
2. Grace, a 49 year-old woman was admitted to the Inkosi Albert Luthuli Central Hospital for cataract extraction. Her eyesight was deteriorating but otherwise she was in good health. In 1990 Grace had undergone thyroidectomy for a multinodular goiter. Routine investigations were carried out using a blood sample from the patient.
Tests
Serum
Calcium 1.66 mmol/l
Phosphate 2.65 mmo/l
Albumin 42 g/l
Alkaline phosphatase 65 IU/L
2.1 Comment on the results. [6]
2.2 What was the main clue for the diagnosis apart from the patient’s results? [1]
3. After a phosphorous analysis using the molybdate method without a reducing agent, the following absorbance readings were obtained:-
Standard (1.6 mmol/l) 0.414
Standard 0.418
Normal control 0.380
Serum A 0.678
Serum B 0.350
Urine sample C (diluted 1 in 5) 0.204
(Volume 1567)
Calculate the phosphorus concentration for all specimens/controls.
If the mean target value for the normal control is 1.41 mmol/l and the SD is 0.10; is your batch of results within acceptable limits?
Which of the two serum samples gives an abnormal result? Can you give a possible cause for it?
Describe the principle of the method used.
Discuss all the precautions that must be taken when a serum sample is taken for phosphate determination. [20]
4. A 50-year-old man presented with weight loss and weakness. The time of the year was winter but his skin was noticeably bronzed. On examination, he was found to have hepatosplenomegaly.
Investigations
Urine positive for glucose
Blood sugar 12 mmol/l
Serum
Iron 58 µmol/l
Transferrin 2.15 g/l
Ferritin 3500 µg/ml
4.1 Predict the diagnosis of the patient. Justify your answer with explanations and show calculations. [8]
5. Provide an explanation / reasons for the following:
Tumor markers are processed in a batch.
Two – way traffic of samples and reports.
Receptions area should be free of clutter.
Bulk of the work is done in the first shift.
Transcription mistakes are not allowed.
[10]
6. Complete the following table.
Laboratory markers of iron status in Disease States
Conditions Serum Iron Transferrin Ferritin % Saturation
Malnutrition 6.1 Variable
Malignancy 6.2
Chronic infection 6.3
Viral hepatitis 6.4
Anaemia of chronic disease 6.5 Normal/
Sideroblastic anaemia Normal / 6.6
Iron deficiency 6.7 6.8
Iron poisoning / overdose 6.9
Haematochromatosis 6.10
[10]
7. Make recommendations of how space could be best utilized when designing a laboratory.
[4]
Chempath test 2
1. State whether the following statements are true or false. If false, correct the statement. [½ mark for True or False – 1 mark for an explanation of the incorrect statement]
In a work flow system, input refers to specimens, request forms and reagents.
For critical care patients, specimens are collected less frequently.
PTH is present in skin and from diet.
One of the causes of hyperphoshatemia is hypothyroidism.
EGTA binds to Mg so that one can measure the calcium content in the patient’s sample.
Aldosterone is antagonistic in that it increases serum Mg by promoting excretion by kidney.
Iron transport is via transferrin where each molecule binds two Fe 2+ ions.
A fetal lung maturity is when the LSAR may be 1.5, PG positive.
[10]
2. Calculate the recovery of the following Fe sample.
Sample 1: 1.0 ml serum + 0.2 ml H2O
Sample 2: 1.0 ml serum + 0.2 ml 10 µmol/l standard
Concentration:
Fe measured
Sample 1 31.0 µmol/l
Sample 2 32.5 µmol/l
[9]
3. Compare diagrams of LSAR in patients with lung maturity and lung immaturity. [6]
4. Write all the precautions of the globulin test for CSF measurement. [4]
5. Compare the laboratory findings of a patient with an exudate to that of another patient with a transudate effusion.
[9]
6. Explain all the factors to be taken when iron is measured. [8]
7. A 21 female with dizzy spells went the local clinic as this was affecting her work at the factory where she was employed. The doctor examined her and had blood samples taken and were sent to the laboratory. A report from the new automated analyser showed the following:
Serum iron: 0.007 mmol/l
7.1 Predict the doctor’s diagnosis based on the result obtained. [3]
7.2 Select the tests that may be done on the above patient. [3]
7.3 Comment on the units of the result. [1]
8. Make recommendations of how space could be best utilized when designing a laboratory. [10]
9. Determine the molarity of a bottle of glacial acetic acid, which has a specific gravity of 1.046 g/ml and a percent assay of 99.2%. [5]
10. A report on a male patient read as follows:
Calcium : 2.25 mmol/l
Phosphate : 0.90 mmol/l
Magnesium : 0.51 mmol/l
10.1 Explain the above results and give the possible diagnosis. [Give reasons for the abnormal result(s)] [7]
10.2 What would the treatment be for the above patient? [1]
[Additional Information: Mass C = 12 H =1 O =12]
In a work flow system, input refers to specimens, request forms and reagents.
For critical care patients, specimens are collected less frequently.
PTH is present in skin and from diet.
One of the causes of hyperphoshatemia is hypothyroidism.
EGTA binds to Mg so that one can measure the calcium content in the patient’s sample.
Aldosterone is antagonistic in that it increases serum Mg by promoting excretion by kidney.
Iron transport is via transferrin where each molecule binds two Fe 2+ ions.
A fetal lung maturity is when the LSAR may be 1.5, PG positive.
[10]
2. Calculate the recovery of the following Fe sample.
Sample 1: 1.0 ml serum + 0.2 ml H2O
Sample 2: 1.0 ml serum + 0.2 ml 10 µmol/l standard
Concentration:
Fe measured
Sample 1 31.0 µmol/l
Sample 2 32.5 µmol/l
[9]
3. Compare diagrams of LSAR in patients with lung maturity and lung immaturity. [6]
4. Write all the precautions of the globulin test for CSF measurement. [4]
5. Compare the laboratory findings of a patient with an exudate to that of another patient with a transudate effusion.
[9]
6. Explain all the factors to be taken when iron is measured. [8]
7. A 21 female with dizzy spells went the local clinic as this was affecting her work at the factory where she was employed. The doctor examined her and had blood samples taken and were sent to the laboratory. A report from the new automated analyser showed the following:
Serum iron: 0.007 mmol/l
7.1 Predict the doctor’s diagnosis based on the result obtained. [3]
7.2 Select the tests that may be done on the above patient. [3]
7.3 Comment on the units of the result. [1]
8. Make recommendations of how space could be best utilized when designing a laboratory. [10]
9. Determine the molarity of a bottle of glacial acetic acid, which has a specific gravity of 1.046 g/ml and a percent assay of 99.2%. [5]
10. A report on a male patient read as follows:
Calcium : 2.25 mmol/l
Phosphate : 0.90 mmol/l
Magnesium : 0.51 mmol/l
10.1 Explain the above results and give the possible diagnosis. [Give reasons for the abnormal result(s)] [7]
10.2 What would the treatment be for the above patient? [1]
[Additional Information: Mass C = 12 H =1 O =12]
chem path test1
Katie is a 35 year old woman with ulcerative colitis presented with diarrhoea and passing blood with her stools. Her HB level was 8.5 g/dl and there was moderate microcytosis and hypochromia. Her plasma iron and ferritin studies revealed:
Plasma
Iron 4 µmol/l
Transferrin 1.5 g/l
% saturation 11.89
Ferritin 33 µg/l
1.1 Comment on the diagnosis of Katie. [7]
Indicate treatment for Katie. [1]
2. The following sets of results were from a 65 year –old woman admitted to the coronary care unit because of chest pain. The ECG and plasma enzyme studies did not reveal a myocardial infarct:
Plasma:
Na 139 mmol/l
K 3.9 mmol/l
Cl 103 mmol/l
HCO3- 25 mmol/l
Urea 6.1 mmol/l
Creat 105 µmol/l
Ca 2.22 mmol/l
PO4 0.86 mmol/l
Mg 0.60 mmol/l
Alb 35 g/l
2.1 Comment on the patient’s results. [10]
Discuss the homeostasis of magnesium. [4]
3. Sharan is a Technologist – in - charge of a private lab. She reports to the lab manager, Tembe who in turn reports to the Pathologist Prof Mokoena. There are 3 qualified Med techs viz. Susan, Prinivan and Dorothy who reports to the QC officer Kinon, Senior med Tech Faizel and senior med Tech Sne’ respectively. Kinon, Faizel and Sne’ reports to Parvathy who is the 2IC. Prinivan’s subordinate is the student med Tech Jabu while the Technician Harry reports to Dorothy. The Technician handles all Peter’s day –to –day matters. Peter is a General assistant. Draw an organogram for this private lab, showing names and titles. [13]
Gives reasons/ explanation of the following:
Patients are bled in a quiet and pleasant area.
“Shute” or vacuum system for specimens.
Urgent specimens are distinguished in the lab
Treatment of Stat samples in a private lab.
Most work is done in the first shift.
Transcription errors are not allowed.[Give an example of an error of this type]
Laboratory staff are always rotated.
Most labs have a 3 way interface system
The two-way traffic in public hospitals has huge benefits.
Card board boxes are not stacked at lab exits.
[10]
Multiple choices. Show working / explanation and give the correct answer.
Calculate the coefficient of variation for a set of data where the mean = 89 mmol/l and the 2 standard deviations = 14.
7.8
7.9
15.7
15.8
A CSF specimen is sent to the lab @ 9 pm for glucose analysis. The specimen is cloudy and appears to contain red blood cells. Which of the following statements is true?
Glucose testing cannot be performed on the specimen
Specimen should be centrifuged and the glucose test run immediately.
Specimen can be refrigerated as received and the glucose run the next day.
Specimen can be frozen as received and the glucose run the next day.
Xanthrochromasia of cerebrospinal fluid may be due to increased levels of which of the following?
Chloride
Protein
Glucose
Magnesium
With the development of fetal lung maturity, which of the following phospholipid concentrations in amniotic fluid significantly and consistently increases?
Sphingomyelin
Phosphatidyl ethanolamine
Phosphatidyl inositol
Phosphatidyl choline
Which of the following is characteristic of an exudates effusion?
Leukocyte count greater than 1000 /µl
Cloudy appearance
Protein concentration less than 3.0 g/dl
Absence of fibrinogen
How many millilitres of concentrated H2SO4 ( sp gravity = 1.84g/ml; assay =97%) are required to prepare 10 L of a 0.1 N H2SO4
1.84
9.20
27.5
54.4
How many grams of NaOH are required to prepare 2500 ml of a 4 M solution?
40
100
160
400
Because of a malfunction, a spectrophotometer is able to show only the percent transmittance (%T) readings on the digital display. Convert 68.0%T to its corresponding absorbance.
0.109
0.168
0.320
0.495
How many grams of a NaOH are required to prepare 500ml of a 0.02N solution?
0.4
0.8
4.0
8.0
How much CaSO4 should be weighed out to prepare one litre of a 0.5 M solution of Ca SO4?
a. 6.8g
b. 0.68g
c. 6800g
d. 68 g
[10 x2 = 20]
6. A lumbar puncture is performed for suspected meningitis.
6.1 Explain the significance of the globulin test in CSF. [2]
6.2 Give the significance of a raised glucose level in CSF. [3]
7. Describe the interfering factors that may give false results in the occult blood test.
[3]
8. With the aid of a diagram show a LSAR chromatography plate indicating a possible
negative and a positive lung maturity. Show calculations of LSAR patterns. [7]
Plasma
Iron 4 µmol/l
Transferrin 1.5 g/l
% saturation 11.89
Ferritin 33 µg/l
1.1 Comment on the diagnosis of Katie. [7]
Indicate treatment for Katie. [1]
2. The following sets of results were from a 65 year –old woman admitted to the coronary care unit because of chest pain. The ECG and plasma enzyme studies did not reveal a myocardial infarct:
Plasma:
Na 139 mmol/l
K 3.9 mmol/l
Cl 103 mmol/l
HCO3- 25 mmol/l
Urea 6.1 mmol/l
Creat 105 µmol/l
Ca 2.22 mmol/l
PO4 0.86 mmol/l
Mg 0.60 mmol/l
Alb 35 g/l
2.1 Comment on the patient’s results. [10]
Discuss the homeostasis of magnesium. [4]
3. Sharan is a Technologist – in - charge of a private lab. She reports to the lab manager, Tembe who in turn reports to the Pathologist Prof Mokoena. There are 3 qualified Med techs viz. Susan, Prinivan and Dorothy who reports to the QC officer Kinon, Senior med Tech Faizel and senior med Tech Sne’ respectively. Kinon, Faizel and Sne’ reports to Parvathy who is the 2IC. Prinivan’s subordinate is the student med Tech Jabu while the Technician Harry reports to Dorothy. The Technician handles all Peter’s day –to –day matters. Peter is a General assistant. Draw an organogram for this private lab, showing names and titles. [13]
Gives reasons/ explanation of the following:
Patients are bled in a quiet and pleasant area.
“Shute” or vacuum system for specimens.
Urgent specimens are distinguished in the lab
Treatment of Stat samples in a private lab.
Most work is done in the first shift.
Transcription errors are not allowed.[Give an example of an error of this type]
Laboratory staff are always rotated.
Most labs have a 3 way interface system
The two-way traffic in public hospitals has huge benefits.
Card board boxes are not stacked at lab exits.
[10]
Multiple choices. Show working / explanation and give the correct answer.
Calculate the coefficient of variation for a set of data where the mean = 89 mmol/l and the 2 standard deviations = 14.
7.8
7.9
15.7
15.8
A CSF specimen is sent to the lab @ 9 pm for glucose analysis. The specimen is cloudy and appears to contain red blood cells. Which of the following statements is true?
Glucose testing cannot be performed on the specimen
Specimen should be centrifuged and the glucose test run immediately.
Specimen can be refrigerated as received and the glucose run the next day.
Specimen can be frozen as received and the glucose run the next day.
Xanthrochromasia of cerebrospinal fluid may be due to increased levels of which of the following?
Chloride
Protein
Glucose
Magnesium
With the development of fetal lung maturity, which of the following phospholipid concentrations in amniotic fluid significantly and consistently increases?
Sphingomyelin
Phosphatidyl ethanolamine
Phosphatidyl inositol
Phosphatidyl choline
Which of the following is characteristic of an exudates effusion?
Leukocyte count greater than 1000 /µl
Cloudy appearance
Protein concentration less than 3.0 g/dl
Absence of fibrinogen
How many millilitres of concentrated H2SO4 ( sp gravity = 1.84g/ml; assay =97%) are required to prepare 10 L of a 0.1 N H2SO4
1.84
9.20
27.5
54.4
How many grams of NaOH are required to prepare 2500 ml of a 4 M solution?
40
100
160
400
Because of a malfunction, a spectrophotometer is able to show only the percent transmittance (%T) readings on the digital display. Convert 68.0%T to its corresponding absorbance.
0.109
0.168
0.320
0.495
How many grams of a NaOH are required to prepare 500ml of a 0.02N solution?
0.4
0.8
4.0
8.0
How much CaSO4 should be weighed out to prepare one litre of a 0.5 M solution of Ca SO4?
a. 6.8g
b. 0.68g
c. 6800g
d. 68 g
[10 x2 = 20]
6. A lumbar puncture is performed for suspected meningitis.
6.1 Explain the significance of the globulin test in CSF. [2]
6.2 Give the significance of a raised glucose level in CSF. [3]
7. Describe the interfering factors that may give false results in the occult blood test.
[3]
8. With the aid of a diagram show a LSAR chromatography plate indicating a possible
negative and a positive lung maturity. Show calculations of LSAR patterns. [7]
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