BOC Questions

How many white blood cells (WBCs) would be considered normal for adult cerebrospinal fluid?

0-5 WBCs/µL

Approximately what percentage of pulmonary emboli originate from deep veins of the legs?

95%

Which of the following statements is true regarding anti-nuclear antibodies?

95% of patients with SLE will test positive for ANAs

What is the minimum volume (milliliters) of Rh positive red blood cells that would be needed to produce anti-D in an Rh negative individual?

< 0.1 mL

What red blood cell component is indicated for patients who receive directed donations from immediate family members to prevent transfusion-associated graft versus host disease (TA-GVHD)?

Irradiated Red Blood Cells

Glucose is considered an aldose because:

It contains a terminal carbonyl group, called an aldehyde group.

The McLeod phenotype is associated with which of the following antigen systems?

Kell

While ABO, Rh, Kell, Duffy, Kidd, SsU are clinically significant, which of the following antibodies generally react at only the Coombs phase (also known as Antihuman Globulin phase)?

Kell, Duffy and Kidd antibodies

The anaerobe producing the double zone of hemolysis, seen in this photograph, can be presumptively identified as Clostridium perfringens. The enzyme producing the outer zone of hemolysis is:

Lecithinase

Bence-Jones proteinuria is associated with all of the following conditions

Macroglobulinemia, multiple myeloma, and amyloidosis

What are the MAIN functions of the distal convoluted tubules?

Maintain water-electrolyte and acid-base balances

Which of the following medications is considered an antineoplastic drug?

Methotrexate

Which of the following organisms is a cause of cutaneous infections?

Nocardia brasiliensis

Which of the following statements regarding the L/S ratio is TRUE?

A ratio of 2:1 or greater usually indicates adequate pulmonary surfactant to prevent respiratory distress syndrome (RDS)

The direct antiglobulin test (DAT) is most unreliable when diagnosing hemolytic disease of the fetus and newborn due to which blood group system?

ABO

A false-negative reaction while performing the DAT technique may be the result of:

AHG addition delayed for 40 or more minutes

Oliguria is usually correlated with:

Acute glomerulonephritis (or occasionally anuria, no urine output)

Which of the following autoantibodies are found in a patient with Hashimotos thyroiditis?

Antithyroid peroxidase (TPO)

The causative agent of infectious mononucleosis attaches to a receptor on which of the following cells?

B lymphocyte

The bacterial species most likely associated with bacillary angiomatosis is:

Bartonella henselae

Cooley's anemia is another name for which form of beta-thalassemia?

Beta thalassemia major

Which is in the correct order from the lowest concentration of H antigen to the highest concentration of H antigen?

Bombay, A1B, A1, A2B, B, A2, O

Which tumor marker is used for colorectal cancer?

CEA

Which of the following is the proper designation for the pluripotential stem cell that is a precursor for both myeloid and lymphoid cell lines?

CFU-S

8-Hydroxyquinoline and Ortho-Cresolphthalein complexone (CPC) reagent is commonly used in the determination of:

Calcium

The purpose of C3a and C5a, the split-products of the complement cascade, is to:

Cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils.

Warfarin-based (coumarin derivative) oral anti-coagulant therapy is commonly monitored with :

PT/INR

All of the following are therapeutic drugs used to treat cardiac disease

Digoxin (used to treat congestive heart failure), Quinidine, and Procainamide (both used to treat cardiac arrhythmias) are common therapeutic cardioactive drugs.

The process of the motion of a liquid when a voltage is applied between the ends of an insulating tube that contains that liquid is known as:

Electroosmosis

Which of the following amoeba is known to have 8 nuclei in the mature cyst form?

Entamoeba coli

After performing an antibody panel and a selected cell panel, you still can't rule out S and Fyb. It appears that the patient has anti-e and anti-Jkb, but they are only reacting microscopically. What technique would be the best way to strengthen the suspected antibodies?

Enzyme panel

A D-test is performed on gram-positive cocci to determine inducible resistance to clindamycin when the isolate is sensitive to clindamycin and resistant to which antibiotic?

Erythromycin

Which of these coagulation factors are referred to as "vitamin-K dependent"?

Factors II, VII, IX, X

Which of these methods measures fetal hemoglobin or D positive red cells or both to evaluate fetomaternal hemorrhage?

Flow cytometry

Acute-phase proteins generally fall into which category?

Glycoproteins

Which of the following blood cell inclusions cannot be detected on a Wright's stained blood smear?

Heinz bodies

Recombinant Factor IX is indicated for which of the following?

Hemophilia B

The Major Histocompatibility Complex (MHC) I genes encode for:

Human Leukocyte Antigens (HLA)-A,B,C

Which of the following is an FDA-approved therapeutic agent for treating sickle cell patients?

Hydroxyurea

Which test result will be normal in a patient with dysfibrinogenemia?

Immunologic fibrinogen level

The biuret reaction for the analysis of serum protein depends on the number of:

Peptide bonds

All of the following tests are useful in the diagnosis of heparin induced thrombocytopenia (HIT)

Platelet aggregometryEnzyme-linked immunosorbant assay (ELISA)Carbon 14 serotonin washed platelet release assay

Hyperacute rejection of a transplanted organ is caused by:

Pre-formed humoral antibodies in a patient

Rothia mucilaginosa is a member of the family Micrococcaceae that has been associated with endocarditis in patients after a cardiac catheterization, as well as intravenous drug users. Which test listed below would be most helpful in making a species identification?

Presence of a capsule

What is the anatomical feature of a tapeworm that possesses both male and female (hermaphroditic) reproductive structures?

Proglottid

All of the following conditions would be associated with an increased level of alpha-fetoprotein, EXCEPT?

Prostate Cancer

Which of the following contributes to specific gravity but does NOT contribute to osmolality?

Protein

Respiratory acidosis is associated with:

Increased pCO2

Which of the following characteristics can be seen in the microcytes present in some hemolytic disorders?

Spherocytosis

In which of the following conditions would one see Pappenheimer bodies on the peripheral blood smear?

Splenectomies

Which organism is associated with sinusitis and otitis and is also considered a leading cause of meningitis with or without bacteremia?

Streptococcus pneumoniae

Which of the following conditions would argue in favor of therapeutic drug monitoring (TDM) for a given drug?

The drug is given chronically.

The qualitative differences between A1 and A2 phenotypes includes all of the following EXCEPT:

The lack of agglutination of patient red cells with anti-A reagent.

Which of the following statements is TRUE for specific gravity measured by the urine chemical reagent strip method?

The urine chemical reagent strip method is not affected by the presence of x-ray contrast media in the urine specimen.

The pI of a protein is 9.2. This protein is placed in an electrical field where a buffer sets the pH at 10.0. Select the correct statement regarding the electrophoretic migration of this protein.

This protein will have a net negative charge and will migrate toward the anode, the positively charged electrode

In healthy individuals, calcitonin is synthesized by which cells in the body?

Thyroid C cells

Acetest® can be used to test for ketones in:

Urine, serum, and whole blood

Which of the following antibiotics does Streptococcus pneumonia still remain sensitive to?

Vancomycin

A hospitalized patient has a decreased serum copper level and increased urine copper level. This is MOST consistent with:

Wilson's disease

MCV = Hct (L/L) x 1000 / RBC count (x1012/L)

Yer

Osmolality = 2 x Na + [Glucose (mg/dL) / 20] + [BUN (mg/dL)/ 3]

Yer

Which cardiac biomarker is a regulator of myocyte contraction?

cTnT

Which tests will be abnormal in a patient with Fibrin Stabilizing factor deficiency?

Both 5 M urea clot solubility test and Factor XIII assay

In the condition kernicterus, the abnormal accumulation of bilirubin occurs in what tissue?

Brain

Which is the most commonly reported organism in cases of laboratory-acquired bacterial infection?

Brucella species

Which of the following microscopic techniques is best suited for direct examination of the infectious agent of syphilis?

Dark-field microscopy

Direct examination of treponemes can be performed by:

Darkfield microscopy examination

(Urine creatinine/plasma creatinine) x (volume / minute) = glomerular filtration rate (mL/min)

Divide by 1440 min

What is the BEST technique for monitoring the severity of hemolytic disease of the fetus and newborn (HDFN)?

Doppler ultrasound

All of the following are true concerning the Erythrocyte Sedimentation Rate (ESR)

ESR can be used to follow the course of a disease Highest ESR values are usually seen in Multiple MyelomaESR values are increased in rheumatoid conditions

Nitric oxide is associated with the prevention of vaso-occlusion by decreasing cellular adherence to endothelium. Which amino acid is decreased in patients with sickle cell disease and is needed as a substrate to produce nitric oxide?

L-arginine

Based on the following genotype (Le) (sese), what would you predict the Lewis antigen phenotypic expression to be?

Le(a+ b-)

What MINIMUM level of a particular factor will cause the aPTT test to become prolonged?

Less than 40%

Abnormal thrombin times (TT) can be caused by all of the following EXCEPT:

Low platelet count

Which of the marrow cells from the list below has highly granular basophilic cytoplasm but does not show nuclear lobules?

Mast cell

Which T lymphocyte expresses the CD8+ marker and acts specifically to kill tumor or virally-infected cells?

T cytotoxic

Which subset of effector lymphocytes is predominantly responsible for regulation of antibody production?

TH2

When a Specked Nuclear Antibody (ANA) pattern is observed, what follow-up test for antibodies related to Systemic Lupus Erythematosus (SLE) is not beneficial?

Testing for antibodies to U1RNP+ and dcSSc

What is the formula for calculating transferrin saturation (TS)?

(Serum iron/TIBC) X 100

Whole blood or red blood cell units will be shipped from the American Red Cross to the transfusion facility. At what temperature should the units be kept during transportation?

1-10 °C

What is the half-life of immunosuppressive drugs cyclosporine and tacrolimus?

10-12 hours

What is the normal ratio of erythroid to myeloid cells found in the normal bone marrow?

1:3

What is the half-life for aminoglycoside antibiotics in the blood?

2-3 hours

How soon must granulocyte concentrates be administered after donation?

24 Hr

What is the lower reference limit for progressive motility of spermatozoa when performing a semen analysis?

32%

Donated red blood cells that contain the anticoagulant CPDA-1 (citrate-phosphate-dextrose-adenine) may be stored up to how many days?

35 days

Serum proteins can be separated by cellulose acetate electrophoresis into how many basic fractions:

5 fractions

Which of the following terms is the external peer-review process that recognizes educational programs that have met established educational standards?

Accreditation

The accuracy of an immunoassay is its ability to discriminate between results that are true positive and results that are true negative. Two parameters of test accuracy are specificity and sensitivity. Which of these statements apply to an immunoassay with high specificity?

Accurately identifies the absence of disease

Raynaud's phenomenon is associated with a deficiency/dysfunction of the complement fraction:

C7

Urine crystals of radiographic contrast media will appear similar to which of the following?

Cholesterol crystals

Which chromosome demonstrates a partial or full gene loci deletion in various forms of beta thalassemia?

Chromosome 11

Which of the following conditions is MOST frequently associated with anti-I?

Cold agglutinin disease

Which of the following crystalline elements are found in acid urine:

Crystals and sediment found in acid urine include cystine, leucine, calcium oxalate, sodium urate, sulfonamide, tyrosine, uric acid, and amorphous urates.

Iontophoresis is a technique used in the diagnosis of:

Cystic fibrosis

The measurement of sodium and chloride in the sweat is the most useful test for the diagnosis of what condition/disease?

Cystic fibrosis

Which of the following hemoglobins is known to migrate with HbS during electrophoresis when an alkaline gel, such as cellulose acetate, is used?

D

A tech is working with a large, spore-forming, Gram-positive bacillus that they believe is Bacillus spp. Which of the following tests could the tech use to ensure this organism is not Bacillus anthracis?

Motility positive

A male patient's urea nitrogen value is 15 mg/dL and his creatinine is 5 mg/dL. If this patient is not undergoing dialysis, what conclusion would you draw from these results?

One of the values is in error

How is valproic acid (Depakote) administered?

Oral preparation

A laboratory test which can detect the specific decrease in the platelet surface membrane receptor glycoprotein Ib and thus lead to a diagnosis of Bernard Soulier Syndrome (BSS) is:

Ristocetin induced platelet aggregation studies

In an emergency release, why do blood bankers seldom encounter patients who have experienced hemolytic transfusion reactions (HTR) from transfusion of uncrossmatched packed RBCs? Select the best response.

The incidence of unexpected red blood cell antibodies is relatively low.

An obese adult with premature arteriosclerosis is seen in the clinic. When her serum is tested no chylomicrons are present, LDL levels are normal, and VLDL levels are increased. There is an increase in triglycerides and a slight increase in cholesterol. Lipoprotein electrophoresis reveals a heavy pre-beta band. She has no skin rash and uric acid is increased. This patient most likely has what type of hyperlipoproteinemia?

Type IV

The type of hypersensitivity reaction associated with macrophage activation, cytokine-mediated inflammation is:

Type IV Cell mediated hypersensitivity (T-cell dependent)

Basophilic stippling is composed of aggregates of ribosomes. Aggregates of iron within erythrocytes are called Pappenheimer bodies. Aggregates of hemoglobin are known as Heinz bodies, which require a supravital stain to observe. Aggregates of DNA found inside an erythrocyte are known as Howell-Jolly bodies.

Yer

The formula for the MCHC is (Hemoglobin (g/dL) / Hematocrit (%)) x 100

Yer

the following are considered a characteristics of paroxysmal cold hemoglobinuria (PCH)

autoantibody class = IgG patient population = children and young adults pathogenesis = following viral infection site of hemolysis = intravascular

Which of the following cardiovascular risk markers is a more sensitive version of a test that is used to assess inflammation?

hs-CRP