Labs Master

Question 0

This antigen hepatitis B antigen is retained in the infected hepatocytes while this antigen is secreted into the blood and is essential for the establishment of persistent infection.

Answer 0

HBcAg

HBeAg

Question 1

Enumerate 5 true liver function tests.

Answer 1

1. Serum albumin
2. Prothrombin time
3. Serum ammonia (high due to defective urea cycle)
4. Aminopyrine breath test (hepatic demethylation)
5. Galactose elimination (IV injection)

Question 2

Stain used to demonstrate copper

Answer 2

Rhodanine for copper

Orcein for copper-associated protein.

Question 3

AFP is non-specific for HCC because it is also elevated in other benign conditions. However, very high levels (>___), are rarely encountered except in HCC.

Answer 3

1000 ng/mL

Question 4

PSA levels

1. Traditional upper limit of normal
2. Level > ___ suggestive of CA

Answer 4

1. 4.0 ng/mL

2. 10

Question 5

Spirochetes may be visualized using ___

Answer 5

Silver stain (ex. Warthin-Starry stain)

Question 6

Syphilis quiz!
Answer either:
A. VDRL/RPR
B. MHA/FTA-ABS
C. Both

1. Remain positive in tertiary syphilis
2. Can be used to monitor response to tx
3. False positive result with collagen vascular diseases
4. Positive by 4 - 6 weeks
5. First test to become positive

Answer 6

A = non-treponemal
B = anti-treponemal

1. B
2. A. Levels of A decline after tx while they remain elevated for B.
3. A. Detects cardiolipin in both spirochete and host tissue
4. C
5. A

Question 7

VDRL and RPR measure antibodies to this antigen present in both host tissues and the treponemal cell wall.

Answer 7

Cardiolipin

Question 8

Causes of false positive VDRLs

Answer 8

Collagen vascular diseases
Drug addiction
Pregnancy
Hypergammaglobulinemia
Lepromatous leprosy

Question 9

Gram stains of purulent exudate in gonorrhea would reveal

Answer 9

Gram negative diplococci within the cytoplasm of neutrophils

Question 10

Diagnosis of Chlamydia infection is best made by:

Answer 10

Nucleic acid amplification tests on voided urine.

Cannot be isolated on conventional culture media

Question 11

A diagnosis of LGV is made by:

Answer 11

Demonstration of the Chlamydia in biopsy sections or smears of exudates

Question 12

Stain used to demonstrate etiologic agent in granuloma inguinale

Answer 12

Giemsa stain
(Minute coccobacilli within vacuoles in macrophages)
or Warthin-Starry (silver) stain

Question 13

Laboratory diagnosis of genital herpes relies on:

Answer 13

Viral culture

Question 14

The average invasive CA found by screening is around ___ in size. How many % are with nodal metastasis?

Answer 14

1 cm.

15%

Question 15

Diffuse axonal injury is characterized by wide and often assymetric distribution of axonal swelling that appears within hours of injury. This is best demonstrated with ____ stains.

Answer 15

Silver stains.

Alternatively, by immunohistochemistry for proteins within axons

Question 16

Cryptococcal meningitis is confirmed by visualization of yeasts in the CSF using ___ and in tissue sections using ____

Answer 16

CSF: India ink

Tissue section: PAS, mucicarmine, silver

Question 17

CSF in multiple sclerosis patients shows ___ protein with and increased proportion of __.

Answer 17

Mildly elevated.

y-globulin

Question 18

Definitive diagnosis of Alzheimer’s disease

Answer 18

Pathologic examination of brain tissue.

Short of this, combination of clinical assessment and modern radiologic methods allows diagnosis in 80-90%.

Question 19

Immunostaining used for tumors arising from Schwann cells

Answer 19

S-100

Question 20

Incubation of pheochromocytoma with __ solution turns the tumor a dark brown color.

Answer 20

Potassium dichromate