Clinical Biochem Gi, Htn

Front 1

What is macroamylasemia?

Back 1

Presence of macroamylase in the blood, which is abnormal. It consists of amylase attached to a protein.

Front 2

Conditions associated with macroamylsemia?

Back 2

1. Celiac disease
2. Lymphoma
3. HIV
4. Monoclonal gammopathy
5. RA
6. Ulcerative Collitis

Front 3

In what way does lipase differ from other pancreatic enzymes?

Back 3

Pancreatic lipase is secreted in its final form but only becomes effective in the presence of colipase in the duodenum.

Front 4

Serum levels of lipase are raised in which conditions?

Back 4

1. Pancreatitis (used to diagnose acute pancreatitis)
2. Pancreatic adenocarcinoma

Front 5

Drugs that may increase lipase levels include

Back 5

1. Codeine
2. Indomethacin
3. Morphine

Front 6

Elastase 1 is a useful marker of

Back 6

Pancreatic exocrine function

Front 7

What is the fecal elastase test?

Back 7

1. Used to assess pancreatic exocrine function
2. Preferred over secretin stimulation test. However, it may have problems detecting mild exocrine pancreatic insufficiency

Front 8

Reason for a blood elastase test?

Back 8

Differentiate between acute and chronic pancreatitis

Front 9

Most common causes of pancreatic insufficiency?

Back 9

1. Cystic Fibrosis
2. Shwachman-Diamond Syndrome (SDS)
3. Type 1 DM

Front 10

Symptoms of pancreatic insufficiency?

Back 10

1. Malabsorption and malnutrition
2. Vitamin deficiencies
3. Weight loss (failure to thrive)
4. Steatorrhea

Front 11

Acute pancreatitis mnemonic

Back 11

I GET SMASHED
I - Idiopathic
G - Gall stones
E - Ethanol
T - Traumas
S - Steroids
M - Mumps, Malignancy
A - Auto-immune
S - Scorpion sting
H - Hypercalcemia, Hyperlipidemia
E - ERCP
D - Drugs

Front 12

Gold standard for diagnosing pancreatitis?

Back 12

CT (and abdominal USG).

Note: XR is not recommended

Front 13

Which scoring system is the most predictive of adverse outcomes in acute pancreatitis?

Back 13

- CT Severity Index.
- A CT score >5 is associated with a 15x mortality rate

Front 14

Which H.pylori strains are more dangerous?

Back 14

Strains producing both VacA and CagA cause more intense tissue inflammation and induction of cytokine production. In addition, CagA strains may be associated with a higher frequency of precancerous lesions.

Front 15

Non-invasive tests for H.pylori?

Back 15

1. Urease Breath Test
2. Serological tests - IgG, IgA, IgM
3. PCR (salive or feces)
4. 13C-Bicarbonate in serum
5. 15-NH4 in urine

Front 16

H.pylori test results may be influenced by

Back 16

1. PPIs
2. H2-blockers
3. Antibiotics

Front 17

Diagnostic tests for celiac disease includes

Back 17

1. IgA-tTGA
2. EMA
3. HLA typing
4. Small bowel histology (most specific and sensitive)

Front 18

Role of Peptide YY?

Back 18

Suppress appetite

Front 19

Hormones that may suppress appetite?

Back 19

1. GLP-1
2. Oxyntomodulin
3. Pancreatic polypeptide

Front 20

Role of CCK?

Back 20

1. Stimulate the pancreas to produce the enzymes of pancreatic juice
2. Causes the gallbladder to empty. It also promotes normal cell growth of the pancreas.

Front 21

Most common diagnostic tool for gastritis?

Back 21

Endoscopy with biopsy

Front 22

Other than [the most common diagnostic test for gastritis] the following tests may be ordered

Back 22

1. Contrast XR
2. Hemofec
3. CBC (anemia)
4. H.pylori tests (RUT, Urea breath test)

Front 23

Complications of chronic gastritis?

Back 23

1. Peptid ulcer disease
2. Gastric polyps
3. Tumors (benign and malignant)
4. Atrophic gastritis

Front 24

Most common causes of cirrhosis?

Back 24

1. HepC
2. Alcohol abuse
3. Obesity

Front 25

Test to assess severity of cirrhosis?

Back 25

MELD. Predicts 90-day survival. Scores 6-40; lower is better.

Front 26

MELD measures which three units?

Back 26

1. INR
2. Bilirubin
3. Creatinine

Front 27

What is Alagille syndrome?

Back 27

AD inherited disease: reduced number of bile ducts-->hepatic insufficiency-->necessitates liver transplant

Front 28

Unique symptoms of Alagille syndrome?

Back 28

Other than liver failure:
1. Heart murmur
2. Deep set eyes, small and pointed chin
3. Opaque ring on the eyes
4. Kidney problems (various)
5. Splenomegaly
6. Abnormal carotid arteries

Front 29

To make a diagnosis of Alagille syndrome, a positive liver biopsy and the presence of three of the following symptoms are usually required:

Back 29

1. liver symptoms
2. heart abnormalities or murmurs
3. skeletal abnormalities
4. posterior embryotoxon
5. facial features typical of Alagille syndrome
(6. JAG1/2 mutation)

Front 30

Indications for ambulatory BP measurement?

Back 30

1. Exclude white coat syndrome
2. Diagnose borderline HTN
3. Deciding Tx options in elderly
4. Identify nocturnal HTN
5. Assessing resistant HTN
6. Determine efficacy of a drug
7. Diagnose and treatment of HTN in pregnancy
8. Diagnosing HYPOtension

Front 31

An increase in stroke volume (SV) can be due to?

Back 31

1. Aortic regurgitation
2. Thyrotoxicosis
3. Hyperkinetic heart syndrome
4. Fever
5. Arteriovenous fistula
6. Patent ductus arteriosus

Front 32

Essential hypertension has a strong genetic predisposition. Candidate genes include?

Back 32

Those that regulate:
1. Sympathetic nervous system
2. RAA-system
3. Production of vasodilators (PGs, NO, etc.)

Front 33

Individuals respond differently to sodium. Which groups are more sensitive to sodium?

Back 33

1. Blacks
2. Elderly
3. Diabetics

Front 34

Lifestyle factors that contribute to HTN

Back 34

1. High dietary salt intake
2. Obesity
3. Excess alcohol consumption
4. Low dietary intake of K, Ca, Mg
5. Oral contraceptives
6. Stress

Front 35

Endocrine causes of secondary HTN

Back 35

1. Primary aldosteronism
2. Pheochromocytoma
3. Hypo-/hyperthyroidism
4. Cushing's syndrome
5. Acromegaly
6. Hyperparathyroidism
7. Carcinoid tumors
8. Congenital adrenal hyperplasia

Front 36

Drugs inducing or exacerbating HTN

Back 36

1. NSAIDs
2. Oral contraceptives
3. Sympathomimetics
4. Glucocorticoids
5. Mineralocorticoids
6. Cyclosporine, tacrolimus
7. EPO
8. VEGF inhibitors
9. Some herbal supplements

Front 37

Diagnostic workup of HTN

Back 37

1. Assess risk factors and comorbidities
2. Reveal identifiable causes of HTN
3. Assess presence of target organ damage
4. Conduct Hx and physical exam
5. Obtain lab tests
6. Obtain ECG

Front 38

Routine lab tests for HTN

Back 38

1. ECG
2. Urinalysis
3. CBC, including fasting Glc
4. Serum potassium, calcium
5. Serum creatinine, or GFR
6. BUN
7. Lipid profile, after 9-12 hrs fast

Front 39

In adults, the best equation for estimating glomerular filtration rate (GFR) from serum creatinine is?

Back 39

the isotope dilution mass spectrometry (IDMS)-traceable Modification of Diet in Renal Disease (MDRD) Study equation.

It does not require weight.

Front 40

GFR and creatinine clearance are poorly interfered from serum creatinine alone. Why?

Back 40

Because these are already inversely related to serum creatinine

Front 41

When expressed as an excretion rate (i.e., urine albumin excretion rate [UAER]), this concentration averages?

Back 41

1. 2.6-12.6 μg/min in males
2. 1.1-21.9 μg/min in females.

Front 42

Definition of microalbuminuria?

Back 42

1. 30-300 mg/d
2. 20-200 μg/min

Front 43

RBC casts in the urine indicates?

Back 43

1. Glomerulonephritis
2. Vasculitis
3. Tumors

Front 44

Cellular or granular casts in the urine indicates?

Back 44

Tubular necrosis

Front 45

By how much must the lumen of the main renal arteries decrease by before it is significant?

Back 45

70%

Front 46

Most common causes of renaovascular stenosis?

Back 46

1. Elderly: atherosclerosis
2. Young: fibrous dysplasia

Front 47

Lab findings in renovascular HTN?

Back 47

1. Hypokalemia
2. Proteinuria (nephrotic syndrome, progressive or otherwise unexplained renal failure)
3. Increased serum creatinine
4. Decreased GFR or sudden increase after ACEI or AT1 blockers

Front 48

Investigative test for renal artery stenosis?

Back 48

Captopril challenge test (more useful in adults than children)

Front 49

To get an accurate interpretation of the peripheral renin activity or renin values, it is recommended that?

Back 49

You measure 24-hr urinary sodium excretion

Front 50

There are several ways to measure the plasma renin activity. What are some pros and cons of IRMA and ICMA?

Back 50

1. Immunoradiometric Assay (IRMA). Uses antibodies. Measures the active form of renin, is unaffected by AT plasma levels. Advantageous when measuring renin in patients with heart or liver failure
2. Immunochemiluminometric Assay (ICMA). Also an immuno assay. Is very rapid.

Front 51

Limitations of the captopril challenge test?

Back 51

1. Bilateral RAS patients may be false negative 2. Sodium depletion may give a false positive in patients with primary HTN 3. Negative results do not rule out RVH

Front 52

Lab findings in primary aldosteronism/Conn's syndrome?

Back 52

1. Low plasma renin
2. Hypokalemia

Front 53

Possible screening tests for PA?

Back 53

1. Serum potassium, 24hr urinary potassium
2. Ratio of urinary potassium to serum potassium

Front 54

Differential in hypokalemia?

Back 54

1. PA
2. Pseudoaldosteronism
3. Secondary aldosteronism (malignant HTN)
4. Diuretics
5. Renal disease
6. Cushing's disease
7. RVH

Front 55

Ideal screening test for primary aldosteronism?

Back 55

Combination of increased Aldosterone/renin ratio (ARR) and plasma aldosterone levels >150 pg/mL

Front 56

Tests that confirm primary aldosteronism?

Back 56

1. Captopril challenge test (if ARR >30, is considered positive)
2. IV saline load
3. Oral soduim load
4. Fludrocortisone suppression test

Front 57

What is the difference between Cushing's syndrome and Cushing's disease?

Back 57

Cushing's syndrome refers to the clinical picture of cortisol excess, regardless of the cause. Cushing's disease refers to an excess of ACTH leading to increased adrenal cortex activity.

Front 58

Biochemical features of Cushing's syndrome?

Back 58

1. Excess endogenous cortisol
2. Loss of feedback on the HPA-axis
3. Abnormalities of the circadian rhythm of cortisol secretion

Front 59

Screening tests for Cushing's syndrome?

Back 59

1. Urinary free cortisol (most widely used)
2. Dexamethasone suppression test
3. Overnight test
4. 2-day low dose dexamethasone test
5. Circadian rhythm assessment

Front 60

Tests to differentiate between ACTH dependent and independent forms?

Back 60

1. Plasma ACTH levels
2. 2-day high dose dexamethasone suppression test
3. Metyrapone stimulation test
4. CRH stimulation test

Front 61

Theory behind the dexamethasone test?

Back 61

In normal individuals it will result in suppression of the HPA-axis, and consequently a fall in plasma and urinary free cortisol. The levels remain high in Cushing's syndrome

Front 62

If plasma cortisol levels are high, and ACTH levels are low, this suggests?

Back 62

ACTH-independent cortisol secretion, usually due to a cortisol secreting adrenocortical tumor

Front 63

Which diagnoses should be considered in a patient whose ACTH and cortisol levels are high?

Back 63

1. Cushing's disease
2. Ectopic coricotropin secreting tumor
3. CRH syndrome

Front 64

Dexamethasone suppression test is useless in patients receiving

Back 64

rifampicin

Front 65

How would you differentiate between pituitary and ectopic ACTH secretion?

Back 65

Metyrapone and CRH stimulation, either alone or in combination with dexamethasone. Patients with a pituitary dependent Cushing's disease will have a marked increase in plamsa 11-deoxycortisol.

Front 66

Lab tests used to screen for Pheochromocytoma?

Back 66

24-hr urine:
1. Fractionated metanephrine
2. Catecholamines
3. Vanillylmandelic acid (VMA)

Front 67

Pharmacologic tests for Pheochromocytomas?

Back 67

1. Stimulation test - glucagon
2. Suppression test - clonidine

Front 68

When should T3 and T4 levels be measured?

Back 68

If TSH value is abnormal.

Front 69

Reason for HTN in acromegaly?

Back 69

Occurs in 1/3 of patients with acromegaly, probably as a consequence of sodium retention and ECF expansion caused by excess GH.

Front 70

Most widely used test for Glucocorticoid-Remediable Aldosteronism?

Back 70

Low-dose dexamethasone suppression test