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]

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]