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CLC621S - CLINICAL CHEMISTRY 2B - 2ND OPP - JANUARY 2025 |
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n Am I B I A u n IVER s ITY
OF SCIEnCE
TECHnOLOGY
Faculty of Health, Natural
Resources and Applied
Sciences
School of Health Sciences
Department of Clinical
Health Sciences
13 Jackson Kaujeua Street
Private Bag 13388
Windhoek
NAMIBIA
T: +264 61 207 2970
F: +264 61 207 9970
E: dchs@nust.na
W: www.nust.na
QUALIFICATION: BACHELOR of MEDICAL LABORATORY SCIENCES
QUALIFICATION CODE: 08BMLS
LEVEL: 6
COURSE: CLINICAL CHEMISTRY 2B
COURSE CODE: CLC621S
DATE: JANUARY 2025
SESSION: 1
DURATION: 3 HOURS
MARKS: 100
SECOND OPPORTUNITY EXAMINATION PAPER
EXAMINER:
MODERATOR:
MR. JAFETIT ILONGA
MRS. FREDRIKAENGELBRECHT
INSTRUCTIONS:
1. Answer all questions on the separate answer sheet.
2. Please write neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
4. No books, notes and other additional aids are allowed.
5. Mark all answers clearly with their respective question numbers.
PERMISSIBLE MATERIALS:
1. Non-Programmable Calculator
This question paper consists of 8 printed pages including this front page.
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SECTION A: MULTIPLE CHOICE
[10 MARKS]
QUESTION 1
[10 MARKS]
Please read each question carefully and select the appropriate letter next to the
corresponding question.
1.1) Kjeldahl's procedure for total protein is based upon the premise that:
(1)
A. Proteins are negatively charged
B. The pKa of proteins is the same
C. The nitrogen content of proteins is constant
D. Proteins have similar tyrosine and tryptophan content
1.2) Upon which principle is the biuret method based?
(1)
A. The reaction of phenolic groups with Cull504
B. Coordinate bonds between Cu+2 and carbonyl and imine groups of peptide bonds.
C. The protein error of indicator effect producing colour when dyes bind protein
D. The reaction of phosphomolybdic acid with protein
1.3} Hyperalbuminemia is caused by:
(1)
A. Dehydration syndromes
B. Liver disease
C. Burns
D. Gastroenteropathy
1.4} Select the protein which migrates in the~ region at pH 8.6 in protein
electrophoresis?
(1)
A. Haptoglobin
B. Orosomucoprotein
C. Antichymotrypsin
D. Transferrin
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1.5) Which of the following conditions is usually associated with an acute inflammatory
pattern?
(1)
A. Myocardial infarction (Ml}
B. Malignancy
C. Rheumatoid arthritis
D. Hepatitis
1.6} Which serum protein should be measured in a patient suspected of having Wilson's
disease?
(1)
A. Hemopexin
B. Alpha'-1 antitrypsin
C. Haptoglobin
D. Ceruloplasmin
1.7) Which of the following affects specific gravity but not osmolality?
(1)
A. Protein
B. Salt
C. Urea
D. Glucose
1.8) Urine with a specific gravity consistently between 1.002 and 1.003 suggests:
(1)
A. Acute glomerulonephritis
B. Renal tubular failure
C. Diabetes insipidus
D. Addison's disease
1.9) A patient's blood gas results are as follows: pH= 7.26, CO2= 2.0 mmol/L, HCO3- = 29
mmol/L. How would these results be classified?
(1)
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
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1.10) Which set of results is indicative of uncompensated respiratory alkalosis?
(1)
A. pH 7.70; HCO3-30 mmol/L; PCO225 mm Hg
B. pH 7.66; HCO3-22 mmol/L; PCO220 mm Hg
C. pH 7.46; HCO3- 38 mmol/L; PCO255 mm Hg
D. pH 7.36; HCO3- 22 mmol/L; PCO238 mm Hg
SECTION B: SHORT AND STRUCTURED QUESTIONS
[30 MARKS]
QUESTION 2
[13 MARKS]
56-year-old female came for a follow-up consultation with a Nephrologist at the Windhoek
Central Hospital. She complained of symptoms, such as tiredness and weakness, which had
developed over a long period. Several years previously she had developed backache due to
lumbar disc prolapse and had habitually consumed large quantities of analgesic tablets. The
patient had already seen the doctor 3 months prior where the doctor performed the tests as
those presented below. Blood was collected at the initial consultation and the findings were
similar 3 months previously at an outpatient clinic visit. Below are the serum and urine
biochemistry results:
Analytes
Sodium
Potassium
Chloride
Bicarbonate
Urea
Creatinine
Calcium
Phosphate
Creatinine
Urine Output
Table 1. Laboratory findings
Serum Chemistry
Results
140 mmol/L
5.5 mmol/L
100 mmol/L
16 mmol/L
33 mmol/L
900 µmol/L
1.9 mmol/L
4.2 mmol/L
Urine Chemistry
4.0 mmol/L
3 L/24 hours
Reference Ranges
136 -145 mmol/L
3.6-5.1 mmol/L
97 -107 mmol/L
22 - 28 mmol/L
1.7 - 6.7 mmol/L
75 - 115 µmol/L
2.1- 2.6 mmol/L
0.8 - 1.4 µmol/L
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2.1) Calculate and interpret the creatinine clearance? Show your calculations.
(5)
2.2) Calculate the patients anion gap and interpret the findings
(3)
2.3) Comment on the plasma bicarbonate concentration result from the laboratory
findings in Table 1?
(2)
2.4) Provide three causes of heavy proteinuria?
(3)
QUESTION 3
[7 MARKS]
3.1) A 24-year-old male is brought to the Casualty Unit of the Medi-Clinic Hospital by
paramedics. The patient was found unconscious on the street and is suspected of
alcohol intoxication by bystanders. Below are the chemistry results shown in Table 2.
Calculate the serum osmolality, determine the osmomal gap, and explain/interpret
the clinical significance of your findings? Show your calculations.
(7)
Analytes
Sodium
Glucose
Urea
Measured osmolality
Table 2. Laboratory findings
Results
135 mmol/L
4.0 mmol/L
6.28 mmol/L
318 mOsm/kg
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QUESTION 4
[10 MARKS]
A 43-year-old woman had a fall at home, multiple fractures were found on X-ray. She had a
5-month history of fatigue and bone pain; however, she did not have other comorbidities.
Chemistry
Reference Ranges
Calcium
2.90 mmol/L
2.2 - 2.6 mmol/L
Creatinine
218 µmol/L
55 - 84 µmol/L
Albumin
31 g/L
35-50 g/L
Haematology: Full Blood Count (Smear Examination)
Erythrocytes: Polychromasia +, Microcytosis +
Leucocytes: Reactive lymphocytes and 31 plasmacytoid cells noted.
Platelets: Mild thrombocytopenia. Manuel platelet estimation: 108 x10E9/L
Table 3. Laboratory findings
4.1} What could be the probable diagnosis (one mark) and explain the biochemical basis
for the symptoms of this clinical condition (four marks)?
(5)
4.2} Illustrate the serum protein electrophoretic pattern observed in the condition
mentioned in 4.1.
(5)
SECTION C: CASE STUDIES
[60 MARKS]
QUESTION 5
[20 MARKS]
A 37-year-old woman presents with complaints of excessive thirst (polydipsia}, excessive
hunger (polyphagia}, and frequent urination (polyuria) at the Outpatient Department of the
Rundu State Hospital. Clinical manifestations include nausea, blurred vision, recurrent skin
infections, numbness or tingling in the hands and feet, as well as sudden weight loss or gain.
The patient's blood and urine biochemical laboratory findings are shown in Table 1.
Analytes
Plasma Glucose
Analytes
Glucose
Table 4. Laboratory findings
Results
10.0 mmol/L
Urinalysis Results
Results
+
Reference Ranges
3.9- 6.1 mmol/L
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5.1) Taking the case and laboratory findings into consideration, what is the most likely
diagnosis (one mark)? Briefly explain the pathophysiology of the condition (three
marks) and conclude by stating other additional laboratory tests or investigation
you would request to confirm the diagnosis (three marks).
(7)
5.2) Explain the biochemical basis of polyphagia and polyuria in relation to the disease? (4)
5.3) What are the laboratory investigations of choice for diagnosing and monitoring
diabetic patients? Motivate your answer.
(6)
5.4) Briefly outline the patient care and management plan for individuals diagnosed with
the condition mentioned in question 5.1.
(3)
QUESTION 6
[20 MARKS]
A 61-year-old man came to the Emergency Centre of Windhoek Central Hospital with
abdominal pain and vomiting that started the night before, along with constipation for the
past week. During the physical examination, he showed signs of numbness and had trouble
moving his arms, especially his hands. The patient's laboratory findings are shown in Table
2.
Analytes
Serum Calcium
Serum Albumin
Serum Alkaline phosphatase
Table 2. Laboratory findings
Results
1.5 mmol/L
35 g/L
453 IU/L
Reference Ranges
2.1- 2.6 mmol/L
35-48 g/L
40-130 IU/L
6.1) What is the most probable diagnosis and list at least six common causes of such a
clinical presentation?
(7)
6.2) State five laboratory tests and briefly explain their clinical significance in confirming
the diagnosis mentioned in question 6.1?
{10)
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6.3} Calculate the corrected calcium and interpret your findings?
(3)
QUESTION 7
[20 MARKS]
A 32-year-old woman admitted at the General Ward of the Oshakati State Hospital
presented with concurrent signs of tiredness and dizziness for two weeks. She was fully alert
and able to speak clearly, with no signs of neurological issues. However, she had noticeable
paleness in her skin and mucous membranes. Peripheral blood smear shows erythrocytes
with marked microcytosis, anisocytosis, and hypochromia. The patient's laboratory findings
are shown in Table 3.
Analytes
Haemoglobin
Red Cell Count
Serum Iron
Total Iron Binding Capacity (TIBC}
Serum Ferritin
Vitamin B12
Folic Acid
Table 3. Laboratory findings
Results
4.6 g/dL
2.8 X 1012/L
0.43 µmol/L
79.0 µmol/L
7.0 µg/L
860.0 pg/L
28.8 ng/L
Reference Ranges
12-16 g/dl
4.0 - 5.0 1012/L
15 - 200 µg/L
39 - 72 µmol/L
15 - 200 µg/L
191- 667 pg/L
4.6 - 18.7 ng/L
7.1) What is the most likely diagnosis, and list five possible causes of this condition?
(6)
7.2} State five biochemical tests that can help confirm the diagnosis mentioned in 7.1,
along with their expected outcomes.
(10}
7.3} Briefly outline the treatment and management plan for patients diagnosed with
the condition mentioned in question 7.1?
(4)
END OF EXAMINATION PAPER
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