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
Thursday, July 28, 2011
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.
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