PRACTICE QUESTIONS PART 4

Which of the following would NOT be a typical methodology for a clinical chemistry test? 

Immunoturbidimetry

Microscopy

EMIT®

ISE

Microscopy

from abbott guide

How should a laboratory verify the reference range it uses for a particular test? 

Call another laboratory

Use the numbers from a textbook

Test samples from healthy people

Look on a medical internet site

Test samples from healthy people (Study individual)

ESTABLISHING A REFERENCE INTERVAL

A new reference interval is established when there is no existing analyte or methodology in the clinical or reference laboratory with which to conduct comparative studies. It is a costly and labor-intensive study that will involve laboratory resources at all levels and may require from ____ to as many as ≈700 study individuals.

20 study individuals

50 study individuals

100 study individuals

120 study individuals

120 study individuals

VERIFYING a reference interval (transference) is done to confirm the validity of an existing reference interval for an analyte using the same (identical) type of analytic system (method and/or instrument). These are the most common reference interval studies performed in the clinical laboratory and can require as few as ____ study individuals.

20 study individuals

50 study individuals

100 study individuals

120 study individuals

20 study individuals (7th& 9th ed. bishop)

40 in 8th ed.

A Gaussian distribution is usually: 

Rectangular

Bell-shaped

Uniform

Skewed

Bell-shaped

Acceptable limits of a control value must fall: 

Within ±1 standard deviation of the mean

Between 1 and 2 standard deviations of the mean

Within ±2 standard deviations of the mean

Within ±3 standard deviations of the mean

Within ±2 standard deviations of the mean

Feedback

For biological studies, control confidence limits are usually established at ±2 SD. When values fall outside these limits, the procedure is considered out of control.

Two standard deviations (2 SD) from the mean in a normal distribution curve would include: 

99% of all values

95% of all values

75% of all values

68% of all values

95% of all values

OUTSIDE - 5% - 5/100 = 1-20 study individual

Feedback

In the bell-shaped normal curve:
±1 SD includes 68% of all of the values
±2 SD includes 95% of the values
±3 SD includes 99.7% of the values

abbott

Which of the following sets of values for repeat analyses of a QC sample (target value of 50) reflects the best precision? 

50, 51, 52

50, 52, 56

48, 50, 52

44, 50, 53

50, 51, 52 (smallest range)

What is used to zero the spectrophotometer before reading the test sample?

Calibrator

Sample blank

Reagent blank

Standard

Reagent blank

during = sample blank

What is the best way to clean up blood that has dripped on the arm of a phlebotomy chair?

Absorb it with a gauze pad and clean the area with disinfectant. 

Rub it with a damp cloth and wash the area with soap and water.

Wait for it to dry and then scrape it into a biohazard container.

Wipe it with an alcohol pad using an outward circular motion.

Absorb it with a gauze pad and clean the area with disinfectant.

Primary glucoregulatory hormone during FASTING: 

Insulin

Glucagon

Epinephrine

Norepinephrine

Glucagon

Feedback

Primary glucoregulatory hormones: insulin and glucagon.

Primary glucoregulatory hormone during fasting: glucagon.

The primary function of this protein is to maintain the colloidal osmotic pressure in the intravascular and extravascular spaces.

Albumin

Prealbumin

Fibrinogen

Transferrin

Albumin

Which of the following tests is a good marker of nutritional status? 

Immunoglobulin M

Prealbumin

Ceruloplasmin

Lp(a)

Prealbumin - transthyretin

>albumin>fibronectin

The protein present in vaginal secretions that can identify patients who are at risk for preterm delivery is:

Human chorionic gonadotropin

Estrogen

PAMG-1

Fetal fibronectin

Fetal fibronectin

Which test is used as an indicator of congestive heart failure? 

CRP

BNP

Cholesterol

Troponin

BNP

recall: TACO - diagnostic post-pre ratio = 1.5x

Which test is the most specific for myocardial infarction? 

LDH

CK

Troponin

Myoglobin

Troponin

In pesticide poisoning, cholinesterase activity is:

Normal

Decreased

Increased

Variable

Decreased

also dec. in liver dx

An emphysema patient suffering from fluid accumulation in the alveolar spaces is likely to be in what metabolic state?

Respiratory acidosis

Respiratory alkalosis

Metabolic acidosis

Metabolic alkalosis

Respiratory acidosis

Feedback

Reduced lung capacity to eliminate CO2 can cause respiratory acidosis.

The expected blood gas results for a patient in chronic renal failure would match the pattern of:

Metabolic acidosis

Respiratory acidosis

Metabolic alkalosis

Respiratory alkalosis

Metabolic acidosis

Feedback

Reduced excretion of acids due to decreased ammonia formation, decreased Na+- exchange, and decreased GFR.

Severe diarrhea causes: 

Metabolic acidosis

Respiratory acidosis

Metabolic alkalosis

Respiratory alkalosis

Metabolic acidosis

Feedback

Excessive loss of bicarbonate, Na+, and K+ due to diarrhea can cause acidosis.

Prolonged vomiting is associated with: 

Metabolic acidosis

Metabolic alkalosis

Respiratory acidosis

Respiratory alkalosis

Metabolic alkalosis - loss of gastric acids

Feedback

CONDITIONS ASSOCIATED WITH METABOLIC ALKALOSIS

Excessive licorice ingestion
Cushing syndrome
Hyperaldosteronism
Cystic fibrosis
Prolonged vomiting
Pyloric or upper duodenal obstruction

The recommended initial thyroid function test for either a healthy, asymptomatic patient or a patient with symptoms which may be related to a thyroid disorder is:

1/1

Free thyroxine (free T4)

Thyroid-stimulating hormone (TSH)

Total thyroxine (T4)

Triiodothyronine (T3)

Thyroid-stimulating hormone (TSH)

Feedback

TSH is the American Thyroid Association's recommended screening test due to the extreme sensitivity of testing methods for detecting endocrine changes. It is useful for monitoring thyroid therapy and to detect subclinical hypo- or hyperthyroidism.

TSH>T4>T3

If a screening TSH is high, which test is likely to be ordered next? 

Cholesterol

Free T4

Ferritin

Glucose

Free T4

Commonly used methods for thyroid hormone measurement except:

CLIA

EIA

LC-MS

RIA

LC-MS (LIQUID CHROMATOGRAPHY MASS SPECTROPHOTOMETRY)

The thyroid gland contains parafollicular cells (C cells), which secrete: 

Calcitonin

T3

T4

All of these

Calcitonin

Feedback

THYROID GLAND

The follicular cells secrete thyroid hormones.

The thyroid gland also contains parafollicular cells (i.e., C cells), which secrete calcitonin.

Which of the following is both hormone and enzyme?

ADH

Angiotensin

Acetylcholinesterase

Renin

Renin

Endocrine gland that secretes melatonin, which helps to maintain the circadian rhythm and regulates LH and FSH levels.

Adrenal gland

Pancreas

Pineal gland

Pituitary gland

Pineal gland

Feedback

The pineal gland secretes melatonin, which helps to maintain the circadian rhythm and regulates LH and FSH levels. The circadian rhythm is a 24-hour biological clock that is influenced by periods oflight and dark.

Melatonin levels are low during the day because light exposure stops the release of melatonin into the blood, and they are high during dark periods, when the hormone is released. Photoperiods influence sleep patterns. Melatonin is thought to block the secretion of LH and FSH.

PLUMBISM, a deleterious effect of gradual accumulation of ______ in body tissues, as a result of repeated exposure.

Arsenic

Cyanide

Lead

Mercury

Lead

safe concentration of lead = alamin

Hazardous material is literally burned to ashes at temperatures of 870° to 980°C.

Autoclaving

Incineration

Inspissation

Pasteurization

Incineration

Feedback

Incineration is the most common method of treating infectious waste. Hazardous material is literally burned to ashes at temperatures of 870° to 980°C.

Incineration is the safest method to ensure that no infective materials remain in samples or containers when disposed.

Prions, infective proteins, are not eliminated using conventional methods. Therefore incineration is recommended.

A class _______ cabinet is selected if radioisotopes, toxic chemicals, or carcinogens will be used.

BSC Class I

BSC Class IIA

BSC Class IIB

BSC Class III

BSC Class IIB

Agents not known to cause disease in healthy adults: 

Biosafety level I

Biosafety level II

Biosafety level III

Biosafety level IV

Biosafety level I - standard microbiological practice by mahon

Common human pathogens: 

Biosafety level I

Biosafety level II

Biosafety level III

Biosafety level IV

Biosafety level II

Agents that may cause serious or lethal disease via inhalation. Effective treatment available. 

Biosafety level I

Biosafety level II

Biosafety level III

Biosafety level IV

Biosafety level III

Agents that pose high risk of life-threatening disease. May be transmitted by aerosols. No vaccine or therapy. 

Biosafety level I

Biosafety level II

Biosafety level III

Biosafety level IV

Biosafety level IV

Standard microbiological practices: 

BSL 1

BSL 2

BSL 3

BSL 4

BSL 1

Typically lancet-shaped and occurs singly, in pairs, or in short chains: 

Staphylococcus epidermidis

Staphylococcus aureus

Streptococcus pneumoniae

Streptococcus pyogenes

Streptococcus pneumoniae

methgb>biliverdin

Four blood cultures were taken over a 24-hour period from a 20-year-old woman with severe diarrhea. The cultures grew motile (room temperature), gram-negative rods. A urine specimen obtained by catheterization also showed gram-negative rods, 100,000 colonies/mL. Given the following results, which is the most likely organism?

TSI = A/A gas 

Indole = + 

MR = + 

VP = Neg

Citrate = Neg

H2S = Neg 

Urease = Neg 

Lysine decarboxylase = + 

Phenylalanine deaminase = Neg

Proteus vulgaris

Salmonella typhi

Yersinia enterocolitica

Escherichia coli

Escherichia coli

imvic = wink with RIGHT eye

TSI = A/A gas (remember EKE)

A leg culture from a nursing home patient grew gram-negative rods on MacConkey agar as pink to dark pink oxidase-negative colonies. Given the following results, which is the most likely organism? 

TSI = A/A 

VP = + 

Urease = + 

Indole = Neg 

Citrate = + 

Motility = Neg 

MR = Neg 

H2S = Neg 

Antibiotic susceptibility: Resistant to carbenicillin and ampicillin

Serratia marcescens

Proteus vulgaris

Enterobacter cloacae

Klebsiella pneumoniae

Klebsiella pneumoniae

A stool culture from a 30-year-old man suffering from bloody mucoid diarrhea gave the following results on differential enteric media: 

MacConkey agar = clear colonies

XLD agar = clear colonies

Hektoen agar = green colonies

Salmonella–Shigella agar = small, clear colonies 

Which tests are most appropriate for identification of this enteric pathogen? 

TSI, motility, indole, urease, Shigella typing with polyvalent sera

TSI, motility, indole, lysine, Salmonella typing with polyvalent sera

TSI, indole, MR, VP, citrate

TSI, indole, MR, and urease

TSI, motility, indole, urease, Shigella typing with polyvalent sera

All of the following are gram-positive spore-forming bacilli, EXCEPT: 

B. anthracis

B. cereus

B. fragilis

B. subtilis

B. fragilis (Bacteroides)

Routine susceptibility testing is not recommended: *

Mycobacterium avium

Mycobacterium fortuitum

Mycobacterium kansasii

Mycobacterium marinum

Mycobacterium marinum

Feedback

Routine susceptibility testing of M. marinum is not recommended, because isolates are consistently susceptible to rifampin, ethambutol, doxycycline/minocycline, trimethoprim–sulfamethoxazole, and clarithromycin.

The agent of verruga peruana and a septicemic, hemolytic disease known as Oroya fever:  

Bartonella bacilliformis

Bartonella henselae

Klebsiella pneumoniae

Klebsiella granulomatis

Bartonella (rokanimiya old?) bacilliformis

Feedback

B. bacilliformis, the agent of verruga peruana and a septicemic, hemolytic disease known as Oroya fever.

Etiologic agent of granuloma inguinale, or donovanosis, a sexually transmitted disease:

Bartonella bacilliformis

Bartonella henselae

Klebsiella pneumoniae

Klebsiella granulomatis

Klebsiella granulomatis

Feedback

B. bacilliformis, the agent of verruga peruana and a septicemic, hemolytic disease known as Oroya fever.

In general, fungal specimens can be _____  only if processing is delayed. 

Incubated at 37C

Refrigerated at 4C

Frozen at -20C

Frozen at -70C

Refrigerated at 4C (elsevier)

Feedback

Fungal specimen transport:
Sterile, leak-proof container
Dermatologic requires dry container
No transport media
Processed within a few hours

Specimens can be refrigerated at 4 C
○ Only if processing is delayed
○ Blood and cerebrospinal fluid (CSF): 30 to 37 C
○ Dermatologic: 15 to 30 C

Storage for blood and cerebrospinal fluid (CSF) for fungal culture: 

20 to 25C

30 to 37C

4C

-20 C

30 to 37C

Feedback

Fungal specimen transport:
Sterile, leak-proof container
Dermatologic requires dry container
No transport media
Processed within a few hours

Specimens can be refrigerated at 4 C
○ Only if processing is delayed
○ Blood and cerebrospinal fluid (CSF): 30 to 37 C
○ Dermatologic: 15 to 30 C

First step in viral replication: 

Attachment

Penetration

Uncoating

Macromolecular synthesis

Viral assembly

Release

Attachment

Feedback

The six steps of virus replication, called the infectious cycle, proceed as follows:
1. Attachment
2. Penetration
3. Uncoating
4. Macromolecular synthesis
5. Viral assembly
6. Release

Specimens collected for virus isolation should be kept at:

37C

20C

4C

- 20C

4C

At what temperature should clinical specimen suspected of containing viruses be kept for transport that takes days?

37C

4C

-10C

- 70C

- 70C

Which of the following is the specimen of choice for detecting rotavirus? 

Throat swab

Urine sample

Bronchoalveolar wash

Feces sample

Feces sample

Ova recovered from the stool are routinely used to diagnose infections caused by all of the following EXCEPT?

Necator americanus

Ascaris lubricoides

Trichuris trichiura

Strongyloides stercoralis

Strongyloides stercoralis - diagnostic stage = rhabdi larva

First-stage larva of flukes that emerge from the egg in fresh water , equipped with cilia, which aid in movement:  

Cercaria

Metacercaria

Miracidium

Redia

Sporocyst

Miracidium

Fluke(s) associated with CHOLANGIOCARCINOMA 

(cancerous growth in bile duct epithelium):

F. buski

P. westermani

C. sinensis, O. viverrini

S. japonicum

C. sinensis, O. viverrini

An operculated CESTODE egg that can be recovered from human feces is:

Clonorchis sinensis

Diphyllobothrium latum

Paragonimus westermani

Dipylidium caninum

Diphyllobothrium latum

Clonorchis sinensis & Paragonimus westermani are TREMATODES

In a condition resulting from the accidental ingestion of eggs, the human becomes the intermediate rather than the definitive host: 

Trichinosis

Cysticercosis

Ascariasis

Strongyloidiasis

Cysticercosis

T. Solium - CESTODESE

brain, spinal cord and eyes

The organism is transmitted through a bite of the tabinid fly or deer fly of the genus Chrysops.

Brugia malayi

Loa loa

Onchocerca volvulus

Wuchereria bancrofti

Loa loa

The parasite is transmitted by the black fly, Simulium spp.

Brugia malayi

Loa loa

Onchocerca volvulus

Wuchereria bancrofti

Onchocerca volvulus

Number of nucleus (nuclei) of the mature cyst of Iodamoeba bütschlii: 

1

2

3

4

1

Not all stages are seen in peripheral blood smear: 

Plasmodium falciparum

Plasmodium malariae

Plasmodium ovale

Plasmodium vivax

Plasmodium falciparum

Gametocyte in a thin smear showing the membrane of the RBC: 

Plasmodium falciparum

Plasmodium malariae

Plasmodium ovale

Plasmodium vivax

Plasmodium falciparum

Routine method of stool examination primarily useful in the detection of motile trophozoites: 

Direct fecal smear (DFS)

Kato thick smear

Formalin ether/ethyl acetate concentration technique (FECT)

Zinc sulfate flotation technique

Direct fecal smear (DFS)

iodine destroy trophs

Useful in MASS STOOL EXAMINATIONS: *

Direct fecal smear (DFS)

Kato thick smear

Formalin ether/ethyl acetate concentration technique (FECT)

Zinc sulfate flotation technique

Kato thick smear

Higher sensitivity for detection of intestinal parasitic infections among FOOD HANDLERS (and OFWs):

Direct fecal smear

Kato thick smear

Formalin ether concentration technique

Sheather's sugar flotation

Formalin ether concentration technique

Best for recovery of coccidian oocysts, mainly Cryptosporidium, Cyclospora and Cystoisospora (Coccidians):

Formalin ether concentration technique

Zinc sulfate flotation

Brine flotation

Sheather's sugar flotation

Sheather's sugar flotation

Normal urine odor: 

Ammoniacal

Cabbage odor

Fragrant

Mousy

Fragrant - Aromatic

ammoniacal = urea to ammonia, happens during inf.

Leaving a reagent strip in the specimen for too long will:

Cause runover between reagent pads

Alter the color of the specimen

Cause reagents to leach from the pads

Not affect the chemical reactions

Cause reagents to leach from the pads

Feedback

Allowing the strip to remain in the urine for an extended period may cause leaching of reagents from the pads.

Leaving excess urine in the reagent strip after removing it from specimen will: 

Cause runover between reagent pads

Alter the color of the specimen

Cause reagents to leach from the pads

Not affect the chemical reactions

Cause runover between reagent pads

Feedback

Excess urine remaining on the strip after its removal from the specimen can produce a runover between chemicals on adjacent pads, producing distortion of the colors.

Which of the following is soluble in dilute acetic acid?

Bacteria

Yeast

Amorphous phosphates, carbonate

White blood cells

Amorphous phosphates, carbonate

Differentiates WBCs and renal tubular epithelial (RTE) cells:

Sternheimer-Malbin stain

Toluidine blue

Prussian blue

Hansel stain

Toluidine blue - nuclei

A method of measuring specific gravity by measuring the change in the frequency of a sound wave after it enters a solution: 

Urinometry

Oscillation densitometry

Reagent strip

Refractometry

Oscillation (Harmonic) densitometry

A clinically significant squamous epithelial cell is the:

Cuboidal cell

Clue cell

Caudate cell

Columnar cell

Clue cell - G. Vaginalis

Forms of transitional epithelial (urothelial or bladder) cells include all of the following except:

Spherical

Caudate

Convoluted

Polyhedral

Correct answer

Convoluted

These crystals resemble a rectangular plate with a notch in one or more corners:

Bilirubin crystals

Cholesterol crystals

Sulfonamide crystals

Tyrosine crystals

Cholesterol crystals

recall: chole is soluble in = chloroform

Yellow-brown spheres that demonstrate concentric circles and radial striations: 

Bilirubin crystals

Leucine crystals

Tyrosine crystals

Uric acid crystals

Leucine crystals

Hoesch screening test: 

Hemoglobin

Ketone

Porphobilinogen

Urobilinogen

Porphobilinogen

For evaluation of sperm motility, examine _______ sperms per slide and count the percentages of the different motile categories using a manual cell counter. 

10 sperms

20 sperms

100 sperms

200 sperms

200 sperms

Feedback

The percentage of sperm showing actual forward movement can then be estimated after evaluating approximately 20 high-power fields.

An alternate procedure is to examine 200 sperm per slide and count the percentages of the different motile categories using a manual cell counter. Motility is evaluated by both speed and direction.

Grading can be done using a scale of 0 to 4, with 4 indicating rapid, straight-line movement and 0 indicating no movement.

A minimum motility of 50% with a rating of 2.0 after 1 hour is considered normal.

Maximum absorbance of amniotic fluid bilirubin and oxyhemoglobin (interference):

Bilirubin 450 nm, oxyhemoglobin 540 nm

Bilirubin 540 nm, oxyhemoglobin 450 nm

Bilirubin 450 nm, oxyhemoglobin 410 nm

Bilirubin 410 nm, oxyhemoglobin 450 nm

Bilirubin 450 nm, oxyhemoglobin 410 nm

Black pleural fluid:

Hemothorax

Chylous material from thoracic duct leakage

Rupture of amoebic liver abscess

Aspergillus infection

Aspergillus infection

Which cluster of differentiation (CD) marker appears during the first stage of T-cell development and remains present as an identifying marker for T cells? 

CD1

CD2

CD3

CD4 or CD8

CD2

Which cluster of differentiation is MOST SPECIFIC identifying marker for mature T cells? 

CD1

CD2

CD3

CD4 or CD8

CD3

IgM in plasma: 

Monomer

Dimer

Pentamer

Pentamer

IgM on the surface of B cells*

Monomer

Dimer

Pentamer

Monomer

1st Ig to appear on B cell surface = IgM

2nd = IgG

Anti-glomerular basement membrane antibody is most often associated with this condition:

Systemic lupus erythematosus

Celiac disease

Chronic active hepatitis

Goodpasture disease

Goodpasture disease

In chronic active hepatitis, high titers of which of the following antibodies are seen?

Antimitochondrial

Anti-smooth muscle

Anti-DNA

Anti-parietal cell

Anti-smooth muscle

ASMA CA4

In primary biliary cirrhosis, which of the following antibodies is seen in high titers?

Antimitochondrial

Anti-smooth muscle

Anti-DNA

Anti-parietal cell

Antimitochondrial (AMA)

Which serum antibody response usually characterizes the primary (early) stage of syphilis? 

Antibodies against syphilis are undetectable

Detected 1 to 3 weeks after appearance of the primary chancre

Detected in 50% of cases before the primary chancre disappears

Detected within 2 weeks after infection

Detected 1 to 3 weeks after appearance of the primary chancre

Tests to identify infection with HIV fall into which three general classification types of tests? 

Tissue culture, antigen, and antibody tests

Tests for antigens, antibodies, and nucleic acid

DNA probe, DNA amplification, and Western blot tests

ELISA, Western blot, and Southern blot tests

Tests for antigens, antibodies, and nucleic acid

sero central dogma: nucleic acid(early)>ag>ab

Which tests are considered screening tests for HIV? 

ELISA 4th generation, and rapid antibody tests

Immunofluorescence, Western blot, radioimmunoprecipitation assay

Culture, antigen capture assay, DNA amplification

Reverse transcriptase and messenger RNA (mRNA) assay

ELISA 4th generation, and rapid antibody tests

Which tests are considered confirmatory tests for HIV? 

ELISA and rapid antibody tests

Western blot test, HIV-1,2 differentiation assays, and polymerase chain reaction

Culture, antigen capture assay, polymerase chain reaction

Reverse transcriptase and mRNA assay

Western blot test, HIV-1,2 differentiation assays, and polymerase chain reaction

Interpret the following results for HIV infection. 

ELISA: positive

Repeat ELISA: negative

Western blot: no bands 

Positive for HIV

Negative for HIV

Indeterminate

Further testing needed

Negative for HIV

Which of the following is used for the confirmation of infection with HIV-1? 

Western blot (immunoblot) assay

ELISA

Complement fixation

p24 Antigen testing

Western blot (immunoblot) assay

Which technique is used for the confirmation of infection with HIV-1 and HIV-2? 

Western blot (immunoblot) assay

ELISA

FDA-approved NAT

 

p24 Antigen testing

Which of the following tests is currently recommended by the CDC to confirm a positive screening test result for HIV infection?

Rapid test for HIV-1 and HIV-2 antibodies

Western blot

Molecular testing for HIV RNA

HIV viral culture

Rapid test for HIV-1 and HIV-2 antibodies

Feedback

Because of its relative insensitivity, level of technical difficulty, and long turnaround time to obtain results, the Western blot test is inappropriate for use as an initial screen for HIV infection.

For these same reasons, as we previously discussed, the CDC has recommended that the Western blot be replaced with rapid HIV-1/HIV-2 antibody tests as the standard method for confirmation of positive screening results.

Tumor markers found in the circulation are most frequently measured by:

Immunoassays

Thin-layer chromatography

High-pressure liquid chromatography

Colorimetry

Immunoassays