Clinical Biochem Old Exam Questions

Front 1

It is most important for a screening test to be

Back 1

specific (to rule out the disease)

Front 2

AST/ALT ratio is useful in

Back 2

differentiating between causes of liver damage

Front 3

A decrease in alpha1-fraction of serum protein electrophoresis is found in patients with

Back 3

emphysema pulmonum

Front 4

Which immunoglobulin is not produced by the fetus?

Back 4

IgA

Front 5

Useful markers of cholestasis

Back 5

1. ALP
2. GGT

Front 6

Classical lipid profile in fat fucks?

Back 6

All the parameters except serum HDL level showed significant increase in obese persons while HDL level was significantly decreased

Front 7

Reference range of bilirubin

Back 7

1. 0.1-1.0 mg/dL
2. 1.7-17uM

Front 8

Correct order of proteinogram, electrophoresis

Back 8

Albumin --> alpha --> beta --> gamma

Front 9

Reference range of the immunoglobulins

Back 9

1. IgG: 800-1800 mg/dL
2. IgA: 70-560 mg/dL
3. IgM: 54-220 mg/dL
4. IgE:0.01-0.04 mg/dL
5. IgD: 0.5-3.0 mg/dL

Front 10

Total respiratory distress is defined by which pO2 and pCO2 values?

Back 10

1. pO2 : <60 mmHg
2. pCO2: >45 mmHg

Front 11

LD1 (HHHH) is found in?
LD2 (HHHM) is found in?

Back 11

1. High oxygen demand tissues; heart, brain, RBCs, renal cortex
2. Lungs, pancreas, spleen, lymphocytes

Front 12

Metoclopramide test values

Back 12

Normally induce a 3-6-fold increase in prolactinemia

Front 13

Diagnosis of preeclampsia can be made based on the following criteria

Back 13

1. New-onset of HTN
2. Unexplained proteinuria (>300mg/24hr)
3. Increased aminotransferases
4. Thrombocytopenia

Front 14

Dry stick test measures

Back 14

albumin

Front 15

Characteristic lab findings in polycystic ovarian syndrome (PCOS)

Back 15

1. Increased FSH and LH
2. Insulin resistance

Front 16

Porphyria cutanea tarda will show up as

Back 16

increased levels of uroporphyrin in the urine

Front 17

Reference value of CK-MB

Back 17

0.0-3.0 ng/mL

Front 18

Diagnosis of SLE is based upon

Back 18

1. Clinical criteria
2. Cytopenias
3. Autoantibodies

Front 19

Definition of sensitivity

Back 19

Proportion of all people with disease who test positive, or the probability that a test detects disease when disease is present

TP=TP/(TP+FN)

Front 20

Definition of specificity

Back 20

Proportion of all people without disease who test negative, or the probability that a test indicates non-disease when disease is absent

TN=TN/(TN+FP)

Front 21

Warfarin interferes with which parts of the coagulation cascade?

Back 21

1. Factors II, VII, IX, and X
2. Protein C, S, Z

Front 22

Formula for calculating plasma osmolality?

Back 22

Osm=2Na + Glucose + Urea

or

Osm=2Na + 2K + Glucose + Urea ( all in mmol/L).

Front 23

The most appropriate tumor marker for medullary thyroid carcinoma?

Back 23

Calcitonin

Front 24

Formula for calculating AG?

Back 24

AG=(Na+K+)-(Cl-HCO3); normally 6-18

Front 25

Detection of paraproteinemia

Back 25

electrophoresis

Front 26

The most important innate anticoagulants

Back 26

1. Protein C and S
2. Antithrombin III

Front 27

How much of the total body calcium is exchangeable?

Back 27

0.4-1.0%

Front 28

Hypochloremic or normal AG acidosis is usually caused by

Back 28

GI loss of bicarbonate

Front 29

Heparin is a

Back 29

cofactor of AT III

Front 30

Sed rate (ESR) is useful for detecting and monitoring

Back 30

1. Autoimmune disorders
2. Certain forms of arthritis
3. Inflammatory diseases that cause vague symptoms
4. Tissue death
5. Tuberculosis

Front 31

Stuff that decreases ESR?

Back 31

1. Polycythemia
2. Spherocytosis

Front 32

The M component in protein electrophoresis

Back 32

is an abnormal monoclonal immunoglobulin occurring in the serum in plasma cell dyscrasias, formed by proliferating concentrations of immunoglobulin-producing cells.

Front 33

Basics of the metyrapone test

Back 33

1. Used in diagnosis of adrenal insufficiency
2. Blocks 11b-hydroxylase; decreases cortisol, increases ACTH

Front 34

Different uses of clonidine in diagnosing

Back 34

1. Clonidine stimulation test - pituitary dwarfism; clonidine causes a marked increase in blood levels of GH
2. Clonidine suppression test - pheochromocytoma

Front 35

Emergency lab works done on an unconscious individual should include:

Back 35

1. Urea and electrolytes
2. ABG
3. Glucose

Front 36

Basics of the insulin-induced hypoglycemia test

Back 36

1. Diagnose anterior pituitary function
2. Increased CRH
3. Increased plasma ACTH
4. Increased serum cortisol
5. Increased serum GH
6. Increased prolactin
7. Induction of SNS

Front 37

There are several isoforms of Alkaline Phosphatase (ALP), where are they found?

Back 37

1. Intestines (ALPI)
2. Liver, bones, kidney (ALPL)
3. Placenta (ALPP)

Front 38

Symptoms of hypomagnesemia may mimic those of

Back 38

hypocalcemia

Front 39

Difference in glucose levels in plasma and capillaries?

Back 39

Lower in the capillaries

Front 40

Basics of the Combined Anterior Pituitary Function Test (CAPFT)

Back 40

1. Three hormones are injected as a bolus into the patient's pituitary
2. These three hormones are:
a. Insulin
b. GnRH
c. TRH
3. The parameters measured are:
a. Serum cortisol, GH, and glucose
b. Prolactin and TSH
c. LH and FSH

Front 41

Tests for monitoring the blood coagulation are usually performed in

Back 41

citrated plasma

Front 42

How do you calculate LDL levels?

Back 42

LDL=TCh-HDL-(TG/5)

Front 43

What the fuck is a Tamm-Horsfall Protein?

Back 43

1. The Tamm-Horsfall glycoprotein (THP) also known as uromodulin is a glycoprotein that in humans is encoded by the UMOD gene
2. Up to 150 mg/dL of uromodulin may be excreted in the urine, making it the most abundant protein in normal urine.

Front 44

ADH levels may be increased in which tumor (that is not like totally obvious, duh!)

Back 44

Oat cell carcinoma of lung

Front 45

The pathognomic increase of CK-MB serum levels after MI is

Back 45

1. Start: 3hrs
2. Peak: 12hrs
3. Duration of rise: 2 days

Front 46

The first easy to estimate symptom of DIC development is

Back 46

Platelet count

Front 47

Which markers are used for monitoring of bone resorption?

Back 47

1. Hydroxyproline (not very specific)
2. Pyridinoline (PUD)

Front 48

The ristocetin aggregation test is used for diagnosing

Back 48

von Willebrand disease

Front 49

How much of total Calcium is bound?

Back 49

50%

Front 50

UTIs can be diagnosed using the following urine dip stick tests

Back 50

1. pH
2. Leukocytes
3. Nitrites

Front 51

The primary use of PCR in microbiological diagnostics is to detect

Back 51

foreign genetic material of the pathogen in patient tissues or body fluids

Front 52

A crude measurement of liver's synthetic capacity is the measurement of

Back 52

serum albumin

Front 53

Heparin-AT complexes inactivate

Back 53

1. Thrombin factor (IIa)
2. Factors Xa, IXa, XIa, and XIIa

Front 54

Anti-TSH Receptor Antibodies are useful in diagnosing

Back 54

Grave's disease (aka Morbus Basedov's disease)

Front 55

Composition of CSF

Back 55

1. Less than 5 lymphocytes/uL
2. pH 7,35
3. 65mg/dL glucose
4. 15-50mg/dL proteins
5. Pressure of 80-180mm H2O

Front 56

Measurement of urine glucose concentration by a glucose oxidase/peroxidase reaction may be deceivingly low due to

Back 56

the presence of ascorbic acid in the urine

Front 57

Cytofluorometry techniques are used in lab diagnostics of

Back 57

1. CBC
2. Immuno phenotyping of leukemia/lymphoma
3. Detection of cell receptor defects

Front 58

Serum amylase activity may be elevated in

Back 58

1. Acute pancreatitis
2. DKA
3. Obstructed pancreatic ducts
4. Mumps
5. Parotitis
6. Tumors

Front 59

Van den Bergh reaction measures?

Back 59

Conjugated bilirubin levels in the blood

Principle:
Bilirubin reacts with diazotised sulphanilic acid to produce purple coloured azo bilirubin

Front 60

Apolipoprotein C-II (ApoC II) activates which enzyme?

Back 60

Lipoprotein lipase

CV:
Mutations in this gene cause hyperlipoproteinemia type IB

Front 61

Tests to diagnose acromegaly?

Back 61

1. Serum IGF-1
2. OGTT
3. Random serum GH

Measurement of GH during OGTT with 75g glucose load is the standard method to confirm acromegaly.

Front 62

Normally, glucose control is assessed by HbA1c levels. Why then, would we need other glycated serum proteins (e.g., fructosamines)?

Back 62

1. HbA1c measures up to the last 4 months, and hence would be inaccurate in patients who have undergone recent diet changes, treatment changes, or simply diseases
2. Fructosamines reflect the glucose levels over the last 2-3 weeks

Front 63

Method for sampling ABG?

Back 63

1. Artery; most commonly radial artery, sometimes brachial or femoral
2. Heparin is pre-added to the syringe to prevent coagulation

Front 64

Define isosthenuria

Back 64

The excretion of urine with fixed specific gravity. It may occur in terminal renal disease when the specific gravity reaches that of the glomerular filtrate, 1.010.

Front 65

Basics of AFP

Back 65

1. Glycoprotein produced by the fetal liver and yolk sac
2. Diagnoses: fetal abnormalities, liver disorders, and to monitor GI and gonadal tumors.
3. Not recommended as a screening test

Front 66

The different blots:

1. Northern blot
2. Western blot
3. Southern blot
4. Eastern blot

Back 66

1. Gene expression - RNA (mRNA)
2. Immunoblot - Detect proteins
3. Detect DNA sequences
4. Analyze protein post translational modifications (PTM) such as lipids and glycoconjugates

Front 67

Lipoprotein(a) characteristics

Back 67

1. Structurally similar to tPA; competes with tPA for its binding site
2. Consists of an LDL-like particle
3. Elevates during an acute phase reaction

Front 68

Basics of the Synacthen test (ACTH stimulation test)

Back 68

1. Fast for 8 hrs
2. Begin test no later than 10am, but preferably as close to 7am as possible
3. Inject 250 µg ACTH, wait about an hour
4. In healthy individuals, the cortisol level should double from a baseline of 20-30 µg/dl within 60 minutes
5. In Addison's disease it may reach the 1000s and even 2000s

Front 69

Jaundice predominantly associated with unconjugated hyperbilirubinemia in

Back 69

Gilbert's syndrome

Front 70

Signs of insulin resistance (IR)

Back 70

1. Hyperglycemia
2. Increased serum TG
3. Increased BP
4. Increased pro-inflammatory cytokines

Front 71

Eosinophilia is not normally seen in

Back 71

AIDS

Front 72

What is pyuria?

Back 72

Pus in the urine (WBCs and bacterial cells)

Front 73

Findings in moderate pancreatic insufficiency.

Back 73

1. Abnormal enzyme secretion
2. Abnormal bicarbonate secretion
3 Normal fecal fat determination

Front 74

What is the significance of a hemolyzed serum sample for Alkaline Phosphatase (ALP)?

Back 74

None; hemolysis does not affect ALP

Front 75

What are the most likely causes of increased ALP levels in a pediatric patient?

Back 75

1. Bone disease (bones healing); exclude child abuse
2. Bowel infarction

Front 76

Earliest cardiac marker?
Most sensitive and specific cardiac marker? High sensitivity and early marker?

Back 76

1. Myoglobin (2hrs)
2. Troponins; peak at 12rs
3. Glycogen phosphorylase isoenzyme BB (GPBB); peaks at 7hrs

Front 77

Diagnosis of viral hepatitis is made by

Back 77

1. AST and ALT elevated out of proportion to ALP, usually with hyperbilirubinemia
2. Viral serologic testing
3. PT measurement

Front 78

Which hepatitis strains do not cause chronic hepatitis or cirrhosis?

Back 78

1. HAV
2. HEV

These two strains have no chronic carrier state

Front 79

We have three main isoforms of apolipoprotein E, ApoE-3, ApoE-2 and ApoE-4. What are they implicated in?

Back 79

1.ApoE-3 is considered the "neutral" isoform
2. ApoE-2: Hyperlipoproteinemia III
3. ApoE-4: Alzheimer's and atherosclerosis

Front 80

Hypertriglyceridemia may be a result of

Back 80

1. Low lipoprotein lipase activity
2. Impaired ApoC-II activity
3. Elevated ApoC-III activity

Front 81

Why is TSH measurement better than T4 when testing for hyperthyroidism?

Back 81

Because TSH secretion is very sensitive to T4

Front 82

c-ANCA is associated with

Back 82

Wegener's granulomatosis

Front 83

p-ANCA is associated with

Back 83

1. Microscopic polyangiitis
2. Focal necrotising and crescentic glomerulonephritis

Front 84

Urine analysis is performed routinely in all children under medical check up because

Back 84

it may detect chronic glomerulonephritis, which is the most prevalent chronic renal disease of children

Front 85

Which test is used for monitoring liver insufficiency?

Back 85

1. ALT/AST
2. LDH
3. PT/INR increas

Front 86

Familiar hypercholesterolemia may be associated with

Back 86

1. Lack of apoB100 receptor
2. Impaired apoB100 protein
3. Impaired apoB100 activity

Front 87

Glucose levels measured in capillary blood is

Back 87

lower than in plasma

Front 88

Amount of protein in normal urine should not exceed

Back 88

20-150mg/day

Front 89

Which enzymes are no longer used for diagnosing MI?

Back 89

1. Total CK
2. AST

Front 90

So-called "preventative screening laboratory tests" are performed to detect

Back 90

inborn and acquired features connected with morbidity and mortality

Front 91

GGT characteristics

Back 91

1. Widely distributed in tissues
2. Elevated in cholestasis
3. Affected by alcohol consumption

Front 92

Optimal levels of LDL in healthy adults

Back 92

<2.6mmol/L

Front 93

Which vitamin is involved in homocysteine catabolism?

Back 93

1. Pyridoxime (B6)
2. Folic acid (B9)
3. Cobalamin (B12)

Front 94

Urine strip tests for UTIs are based on detection of

Back 94

1. Nitrates
2. Leukocyte esterase
3. Proteins

Front 95

Earliest specific marker for MI is

Back 95

1. GPBB (peaks at 7hrs, high sensitivity and specificity)
2. TnT (peaks at 12hrs)

Front 96

Biochemical profile of congenital adrenal hyperplasia?

Back 96

1. Low cortisol levels
2. Low aldosterone levels
3. Hyponatremia
4. Hyperkalemia

Front 97

RT-PCR is used for monitoring of interferon gamma therapy of

Back 97

1. HepC
2. CML

Front 98

Characteristics of IL-6

Back 98

1. Both pro-inflammatory and anti-inflammatory
2. Secreted by both T-cells and macrophages

Front 99

New early markers of MI include

Back 99

1. Myosin light chain
2. CRP
3. FA binding proteins

Front 100

Diseases that are accompanied by hyperlipidemia

Back 100

1. Hypothyroidism
2. Nephrotic syndrome
3. Liver cirrhosis

Front 101

Upper limit of TGs for Friedwald's equation for calculating LDL and cholesterol concentrations

Back 101

1. 4.6mmol/L
2. 400mg/dL

Should also not be used when chylomicrons are present or in patients with type III hyperlipoproteinemia

Front 102

Peptide C is a marker of

Back 102

insulin secretion (used to distinguish between diabetes type I and type II)

Front 103

Cholestasis is associated with high levels of

Back 103

bilirubin in the urine

Front 104

Normal amount of cells found in CSF?

Back 104

<5

Front 105

What is GFR?

Back 105

Glomerular filtration rate (GFR) is the volume of fluid (plasma) filtered from the renal glomerular capillaries into the Bowman's capsule per unit time

Front 106

Diagnostic criteria for glucose intolerance?

Back 106

1. Fasting plasma glucose level from 6.1 mmol/l (110 mg/dL) to 6.9 mmol/l (125 mg/dL)
2. two-hour glucose levels of 140 to 199 mg per dL (7.8 to 11.0 mmol) on the 75-g oral glucose tolerance test

Front 107

Stretch of cardiac muscle cells results in the release of?

Back 107

ANP

Front 108

Genetic material of HepC is made up of?

Back 108

ssRNA

Front 109

Hyperinsulinemia is suggested by a serum insulin to serum glucose ratio of

Back 109

> 0.3 uU/mL/(mg/dL)

Front 110

Microalbuminuria is defined as ____ of albumin in the urine

Back 110

30-300 mg/24hr

Front 111

Tubular proteinuria is defined as, and seen in?

Back 111

Definition: LMW Proteins in the urine; less than 150-1500mg/24hrs.

1. Pyelonephritis
2. Fanconi syndrome
3. Medullary cystic disease
4. Heavy metal poisoning

Front 112

Three most common acute complications of diabetes mellitus (DM)?

Back 112

1. DKA
2. Hypoglycemic coma
3. Hyperosmolar non-ketonic coma

Front 113

A GFR estimation is mainly based on? And how is it calculated?

Back 113

1. Creatinine
2. GFR=((U*V)/P) * (A/1.73); U=urine Cr, P=plasma Cr, V=urine flow, A=body surface area.

To summarize, we need:
1. Plasma and urine Cr levels
2. Urine flow (mL/min)
3. Surface area

Front 114

Monitoring of Warfarin and Heparin?

Back 114

1. Warfarin: INR
2. Heparin: aPTT, PTT; in conjunction with PT

Front 115

Reference range for glycated Hb?

Back 115

1. 5.5%-7%
2. >7% points to hyperglycemia in the previous 60 days

Front 116

Commercially available tests for ketone bodies measure

Back 116

acetoacetate

Front 117

Plasma osmolality in:
1. Pre-renal failure
2. Renal failure

Back 117

1. >1.5
2. <1.1; usually due to:
a. Chronic and acute renal failure
b. Potassium depletion
c. Diabetes insipidus (no ADH)

Note: If the polyuria is due to osmotic diuresis, then the U:P ratio will be >1.5

Front 118

AHA and updated NCEP criteria for metabolic syndrome (aka., Reaven's syndrome and polymetabolic syndrome).

Back 118

Three or more of the following:

1. Elevated waist circumference
2. Elevated TG
3. Low HDL
4. High BP
5. >110mg/dL (6.0mmol/L) Glucose

Front 119

WHO definition of metabolic syndrome

Back 119

Either:
1. Impaired Glc regulation or diabetes
2. Insulin resistance
With two or more of the following:
1. High BP
2. High TG
3. Low HDL
Central obesity
4. Microalbuminuria

Front 120

PCR works by amplifying DNA. How can you detect RNA viruses with PCR?

Back 120

Reverse Transcriptase PCR (RT-PCR)