Media Lab Exam Simulator - ASCP

What percentage of glycerol is generally used when freezing red cells of rare phenotypes: The correct answer is highlighted below 70 % 40 % 10 % 5 %

40

Hemophilia A, hemophilia B, and Von Willebrand's disease together constitute approximately what percentage of all hereditary coagulation disorders: The correct answer is highlighted below 90% 80% 60% 40%

90

The part of the molecule responsible for differences among immunoglobulin classes is: The correct answer is highlighted below Fc Fab heavy chains light chains Hinge regions

Antibodies are differentiated based on their heavy chains; different heavy chains create different isotypes. Humans have five different isotypes of immunoglobulins.

Which of the following antigens are well developed on fetal cells? The correct answer is highlighted below Lewis ABO Kell

Antigens develop at various rates both in utero and after birth. Kell is an antigen that is well-developed on fetal cells, ABO is slightly weaker, and Lewis is either poorly developed or not present at all on fetal cells.

Type B blood is found in higher frequency in: The correct answer is highlighted below African Americans Caucasians Asians Hispanics

Asians

Dimorphic red cell population

Demonstrates two peaks in the red blood cell histogram. Dimorphic red blood cell populations can be found in conditions/situations such as: red blood cell transfusions, myelodysplasia, refractory anemia with ringed sideroblasts, hemolytic processes involving a reticulocyte response, and when patients are given erythropoietin therapy. It is important to recognize when a population of cells in the peripheral smear is not in context with anticipated laboratory findings and the clinical situation.

The cell diameter of a normal RBC is slightly smaller than the nucleus of a small lymphocyte. The correct answer is highlighted below True False

Normal red blood cells are round, biconcave, and measure about 6-8 µm in diameter. Their size can be compared to the nucleus of a small lymphocyte. This is a good way to estimate RBC shape on a peripheral smear if the MCV is not available.

Which one of the following does NOT have capsular material as a defense mechanism? The correct answer is highlighted below H. influenzae K. pneumoniae N. meningitidis S. aureus S. pneumoniae

S. aur

When given during pregnancy, RhIg may cross the placenta and cause a positive DAT in the newborn. The correct answer is highlighted below True False

true

Which of the following staining methods would you use to demonstrate the metachromatic granules of Corynebacterium diphtheriae: The correct answer is highlighted below Acid fast Gram Trichrome Methylene blue

Methylene blue stain can be used to visualize the metachromatic granules that are characteristic of C. diphtheriae.

Why are small dense LDL molecules more atherogenic? The correct answer is highlighted below Small dense LDL molecules contain less cholesterol and phospholipid Small dense LDL molecules increase the concentration of HDL-C in the blood Small dense LDL molecules increase the concentration of adoponectin and inflammatory cytokines Small dense LDL molecules have greater mobility in the endothelium and arterial wall

Most researchers believe that the small size and increased density of LDL molecules found in atherogenic dyslipidemia enable the molecules to more easily invade the endothelium and arterial wall of vessels.

What is the MOST likely identity of an acid-fast bacilli that showed buff colored, dry, heaped colonies; niacin, nitrate, and urease positive; and took 23 days at 35ºC to grow? The correct answer is highlighted below Mycobacterium avium Mycobacterium kansasii Mycobacterium bovis Mycobacterium tuberculosis Mycobacterium leprae

Mycobacterium tuberculosis

Which one of the following blood group antigens is not expressed, or only weakly expressed on cord blood cells? The correct answer is highlighted below K Jka M Leb ABO

Newborns are phenotypically Le(a-b-)

In a normal CSF the protein concentration as compared to that in the serum is generally: The correct answer is highlighted below Less than 50% Less than 30% Less than 10% Less than 1%

Normal ratio of serum to CSF Protein is about 200 to 1, or less than 1%. Elevation of CSF total protein is a nonspecific finding, but usually indicates some type of disease involving the brain or meninges.

Which disorder exhibits a genetic code that is incompatible with life? The correct answer is highlighted below Heterozygous alpha thalassemia minor Homozygous alpha thalassemia minor Hemoglobin H disease Alpha thalassemia major

Alpha thalassemia major, also known as Hydrops Fetalis, is exhibited when all four alpha chain gene loci are deleted or non-functional. The alpha chain is crucial to the formation of hemoglobin variants that can conduct normal oxygen transport and gas exchange. The genetic code --/-- (alpha thalassemia major) is therefore incompatible with life.

Which of the following media would you use to isolate Francisella tularensis: The correct answer is highlighted below Sheep-blood agar Lowenstein-Jensen media Bordet-Gengou media Cysteine-blood agar

Although cysteine-blood agar was traditionally used, F. tularensis will also grow on commercially available Thayer-Martin and chocolate agar which have been enriched with supplemental nutrients.

What is an appropriate use for molecular (DNA) tests for mutations of the HFE gene, the gene found in the majority of patients diagnosed with hereditary hemochromatosis (HH)? The correct answer is highlighted below testing family members of persons with HH screening of all newborns predicting the severity of iron overload identifying persons with iron overload

An appropriate use for molecular (DNA) tests for HFE mutations is testing family members of persons with HH. Newborn screening for HH is not recommended. The presence of HFE mutations does not detect or predict severity of iron overload.

The organism that is a strict anaerobe, non-motile, gram-negative bacillus, occurring in abscesses and associated with peritonitis is MOST likely: The correct answer is highlighted below Haemophilus Bordetella Bacteroides Brucella

Bacteroides species are the most common isolates of the anaerobic gram-negative bacteria in the clinical laboratory. This family of bacteria is non-motile. Bacteroides are frequently isolated from intraabdominal infections (such as in abscesses) resulting from a tear in the intestinal mucosa. Haemophilus spp. are not strict anaerobes. Bordetella spp. and Brucella spp. are both aerobes.

Based on the following results obtained against a patient's red cells, what will the genotype look like in this example? Anti-C = 4+ Anti-c = 4+ Anti-E = 0 Anti-e = 4+ Anti-D = 0 The correct answer is highlighted below RoRo rr r'r R1R2 ryry

Based on the positive antigen results given, the most likely Fisher-Race phenotype is Cde/cde. It is necessary to convert between Wiener system shorthand nomenclature to Fisher-Race nomenclature in order to make this determination. For example: Wiener Fisher-Race Ro Dce R1 DCe R2 DcE Rz DCE r dce r' dCe r" dcE ry dCE

When given during pregnancy, RhIg may cross the placenta and sensitize fetal D-positive RBCs. The correct answer is highlighted below True False

Because RhIg contains IgG anti-D, it can cross the placenta and sensitize fetal Rh positive red cells. Affected infants may be born with a weakly positive DAT, but significant hemolysis does not occur.

Which of the following methods may be employed to definitively identify Bence-Jones proteins: The correct answer is highlighted below Immunoelectrophoresis Sulfosalicyclic acid precipitation Heat precipitation at 40-60oC Urine dipstick

Bence Jones protein is a protein that is excreted by persons with multiple myeloma, a myeloproliferative disorder of the immunoglobulin-producing plasma cells. The protein, which is markedly elevated in blood serum, is filtered through the kidneys in quantities that exceed the tubular reabsorption capacity. Consequently, it is excreted in the urine. All suspected cases shoud have protein and immunoelectrophoresis performed on both serum and urine.

Which of the following statements are true for the hematopoietic cords? The correct answers are highlighted below hematopoietic cells develop at random locations in the marrow cells adventitial cells provide support for developing hematopoietic cells lymphocytes are not seen in normal marrow fat cells make up 50% of volume in an adult

Both B and D are correct for this question. Adventitial cells provide support for developing hematopoietic cells and the average adult has about 50% fat cells (adipose cells) that make up the volume of their bone marrow.

Which cardiac biomarker is a regulator of myocyte contraction? The correct answer is highlighted below Myoglobin cTnT CK-MB CK-MB isoforms

Both cTnI and cTnT are components of the regulation of myocyte contraction.

Which real-time PCR quantification method is only effective if the amplification efficiency of both target and reference samples are equal? The correct answer is highlighted below Standard Curve Method Comparative Threshold Method

he comparative threshold method or Ct involves comparing the Ct of samples against non-treated RNA samples. The Ct or threshold cycle is the cycle in which the fluorescence crosses the point where enough amplicons have been generated. In order for this method to be effective the amplification efficiency of both target and reference samples needs to be equal, if not the standard curve method should be used.

Which of the following is TRUE of a fully compensated metabolic acidosis? The correct answer is highlighted below pH will be decreased without a decrease in PCO2 pH will be decreased with a decrease in PCO2 pH will be decreased with an increase in PCO2 pH will be normal with a decrease in PCO2 pH will be normal with normal O2

he pH will be normal in a fully compensated form of any alkalsis or acidosis. In this case, the problem is metabolic, meaning a decrease in bicarbonate (alkaline) production which has lead to an acid pH of the blood. To compensate for this, the body uses the respiratory system to decrease the amount of acid, or PCO2 in the system to balance the pH into normal range.

Which of the following cardiovascular risk markers is a more sensitive version of a test that is used to assess inflammation? The correct answer is highlighted below Oxidized-LDL hs-CRP ApoB/ApoA1 LpPLA2

hs-CRP is a more sensitive version of the C-reactive protein (CRP) test, a test that has been used for many years to assess inflammation in settings such as lupus, transplantation, infection, etc.

Hormonal variation throughout the menstrual cycle typically shows: The correct answer is highlighted below an abrupt rise in LH 24-36 hours prior to ovulation progesterone peaking at ovulation then falling estrogen peaking at ovulation then falling

the LH surge is required for ovulation. In fact, 24-36 hours after the Luteinizing Hormone surge, the follicle releases an ovum, which is called ovulation. After ovulation, the corpus luteum produces large amounts of progesterone while estrogen levels are also increased in order to prepare the uterus for a possible pregnancy.

Bacterial colonies often emit distinct odors associated with foods. Match the names of each of the foods listed with its associated bacterial species. Your answers are on the left. The correct answers are on the right and highlighted. Grapes Pseudomonas aeruginosa Popcorn CDC group EF4 Peeled apples Alcaligenes faecalis (odorans) Butterscotch Streptococcus milleri

A colony that produces a distinct fruity odor, often likened to freshly peeled apples, is characteristic of Alcaligenes faecalis (odorans) or Flavobacterium odoratum. The tiny, minute colonies of Streptococcus milleri can be presumptively identified if a distinct butterscotch odor is detected. The odor of Pseudomonas aeruginosa is most commonly referred to as grape-like. The smell of popcorn is most indicative of CDC group EF4.

Oral candidiasis may be directly exacerbated by the habitual ingestion of: The correct answer is highlighted below Tofu Cola Alcohol

A diet high in sugar, particularly sucrose (used in non-diet colas), increases the carriage rate of oral Candida species and aggravates mucosal infection, particularly among those wearing dentures. Alcohol will have no direct effect on candida stomatitis. Tofu and other protein foods will not influence oral candidiasis.

Which of the following tests would be used to directly document the presence of a specific organism in a clinical specimen: The correct answer is highlighted below ELISA test Hemagglutination test Hemagglutination inhibition test Direct fluorescent antibody test

A direct fluorescent antibody test (DFA) can be used, for example, to detect antigens of Legionella, Bordetella, Neisseria, and Treponema in appropriate clinical specimens. However DFA can detect only antigens, not antibodies.

Which of the following may cause a false positive bilirubin result on a urine chemical reagent strip? The correct answer is highlighted below Urobilinogen Presence of nitrites Large doses of chloropromazine Urobilin

A large dose of chloropromazine, also known as Thorazine, may cause a false positive bilirubin result on a urine chemical reagent strip. This may be caused by a lowered urine pH in the presence of this compound.

A reaction is in ____________ kinetics when the reaction rate depends only on enzyme concentration. The correct answer is highlighted below zero order first order second order mixed order none of the above

A reaction is in zero-order kinetics when the reaction rate depends only on enzyme concentration.

The accuracy of an immunoassay is its ability to discriminate between results that are true positives and results that are true negatives. Two parameters of test accuracy are specificity and sensitivity. Which of these statements apply to an immunoassay with high specificity, but low sensitivity? The correct answers are highlighted below Accurately identifies the presence of disease Accurately identifies the absence of disease Has few false-positives Has few false-negatives

A test with high specificity accurately detects the absence of disease. The more specific a test is, the fewer false-positive results will occur. A test with high sensitivity accurately identifies the presence of disease. The more sensitive a test, the fewer false-negative results it produces. In the case stated in this question, the immunoassay has high specificity, so it has few false-positives and will accurately detect those individuals who do not have the disease or condition that is being tested for. However, the test has low sensitivity, so it may not identify all individuals who actually have the disease; it may produce many false-negative results.

Which of the following conditions would NOT be associated with an increased level of alpha-fetoprotein? The correct answer is highlighted below Prostate Cancer Hepatocellular Carcinoma Viral Hepatitis Testicular Tumors Pancreatic Cancer

AFP is not found in increased levels in patients with prostate cancer. PSA, or prostate specific antigen, is commonly used to screen for prostate cancer. Hepatocellular carcinoma, viral hepatitis, testicular tumors, and pancreatic cancer are all associated with increased levels of AFP. In addition, liver cirrhosis and gastric cancers can also have an associated increased AFP level.

An abnormality of which of the following assays would be least likely to be associated with thrombotic tendency: The correct answer is highlighted below AT III Protein C APTT Protein S

APTT is used to evaluate the intrinsic pathway. Deficiencies of Protein C, Protein S, and Antithrombin III all cause hypercoagulability.

Which of the following are useful serological tests to document antecedent Streptococcal infections: The correct answers are highlighted below ASO anti-DNAse M-antigen Hemolysin

ASO (antistreptolysin O titer) and DNAse (antideoxyribonuclease-B titer) are tests that can be used to detect antecedent streptococcal infections. The ASO is usually utilized to determine whether a previous group A Streptococcus infection has caused a poststreptococcal disease, such as rheumatic fever, scarlet fever, or glomerulonephritis. The anti-DNase test is utilized to determine whether a previous infection of group A beta-hemolytic Streptococcus has occured.

Acute phase proteins generally fall into which category? The correct answer is highlighted below Glycoproteins Immunoglobulins Lipoproteins Microglobulins

Acute phase proteins are a large group of glycoproteins found in the blood that are not related to immunoglobulins. Acute-phase proteins are generally a class of glycoproteins whose plasma concentrations increase, known as positive acute-phase proteins, or decrease, known as negative acute-phase proteins, in response to inflammation.

Which adipokine is decreased in obesity, is anti-inflammatory, and increases insulin sensitivity? The correct answer is highlighted below Leptin Resistin TNF-a Adiponectin IL-6 Angiotensinogen

Adiponectin is a protective cytokine. This cytokine is anti-inflammatory and increases insulin sensitivity. Adiponectin is usually decreased in obesity.

Which of the following organisms display the characteristic "Medusa head" on sheep blood agar (SBA) after 18 hours of incubation at 35°C? The correct answer is highlighted below Yersinia pestis Bacillus anthracis Francisella tularensis

After 18 hours of incubation on SBA at 35°C, the slightly undulate margin of B. anthracis may show curling, displaying a so-called "Medusa head" appearance. This characteristic is also described as comma-shaped protrusions. A distinguishing characteristic of Yersinia pestis is its preference and faster growth that occurs at 25°C. At 24 hours of incubation on SBA at 35°C, colonies are only pinpoint and translucent with a gray-white color. F. tularensis can grow poorly or not at all on SBA, producing only tiny, pin-point, translucent colonies at best after 18-24 hours. This organism prefers cystein-enriched media such as chocolate (CHOC), Thayer-Martin (TM), and buffered charcoal-yeast extract (BCYE). It would be difficult to see individual colonies on SBA growth that is less than 24 hours old.

A group A Rh positive infant born to a group O Rh negative woman has a 1+ positive DAT. The mother had a negative antibody screen at delivery and received antenatal RhIg. Which of the following are possible causes of the newborn's positive DAT? The correct answer is highlighted below Anti-A Passive anti-D Antibody to a low frequency antigen All of the above are possible causes None of the above are possible causes

All are possible causes. Anti-A is possible because the mother is group O and the newborn is group A. Passive anti-D is possible because the mother received antenatal RhIg and the infant is D+. An antibody to a low frequency antigen is possible because the mother's antibody screen is negative and antibody screen cells are not usually positive for rare antigens.

Which of the following serological test results may occur in a patient experiencing a hemolytic transfusion reaction due to antibodies such as anti-c and anti-K? (Select all that apply.) The correct answers are highlighted below Patient's antibody strength may initially decrease. Patient may develop a positive DAT with mixed-field agglutination. Patient's antibody becomes undetectable. Patient's antibody increases in titer weeks later.

All are possible. The patient's antibody strength can initially decrease due to adsorbing to transfused antigen-positive donor red cells. This results in a positive DAT with mixed-field agglutination, since only the transfused donor cells are antibody-sensitized. The patient's antibody may even become undetectable at the stage when most of it has adsorbed to the donor cells. Eventually, the patient's antibody increases in strength. This may become apparent weeks later, depending on the relative amount of antibody compared to donor red cells present in the patient's circulation.

The CAMP reaction is most helpful in the identification of beta hemolytic streptococci, group B (shown in the photograph as the arrowhead-shaped zone of hemolysis at the tip of the red arrow). A beta hemolytic gram positive bacillus that produces the rectangular-shaped area of hemolysis as shown by the blue arrow in the photograph is: The correct answer is highlighted below Bacillus cereus Arcanobacterium (Corynebacterium) Listeria monocytogenes Gardnerella vaginalis

All of the species of gram positive bacilli listed in this exercise are beta hemolytic. However, the beta hemolysis of Gardnerella vaginalis is only demonstrated when agar containing human blood is used. However, of all the species listed in this exercise, only Listeria monocytogenes produces the rectangular-shaped zone of accentuated hemolysis in the CAMP test. Because both group B, beta hemolytic streptococci and L. monocytogenes can cause meningitis in neonates and young children, the rectangular shaped positive CAMP reaction may be a helpful clue to the correct identification in cases where the colonial morphology on primary isolation medium and gram stain features are equivocal.

False-positive tests for protein on a urine reagent strip may be caused by: (Choose ALL of the correct answers) The correct answers are highlighted below Bacterial contamination Urine that has remained at room temperature for an extended period of time Alkaline medication Ascorbic acid

Bacterial contamination, urine that has remained at room temperature for an extended period of time, and the presence of alkaline medication are all factors which can cause false positives on the protein pad of a urine reagent strip.

Which one of the following statements is NOT characteristic of the role of C-reactive protein (CRP)? The correct answer is highlighted below Activates complement. Binds with factor H to initiate alternate complement pathway. Exhibits both pro-inflammatory and anti-inflammatory characteristics. Initiates Opsonization.

C-reactive protein, or CRP, can activate complement, exhibit both pro- and anti- inflammatory characteristics, and initiates opsonization. However, CRP does not actually bind with factor H to intiate the alternate complement pathway

Isoenzymes of CK include all of the following except: The correct answer is highlighted below MB MM MBM BB

CPK-BB is found mainly in the brain and lungs. CPK-MB is found mainly in the heart. CPK-MM is found mainly in skeletal muscle. There is no such thing as CK-MBM

Chylomicrons are primarily composed of: The correct answer is highlighted below Cholesterol Triglycerides Phospholipids Proteins

Chylomicrons are synthesized in the intestine. They are responsible for transporting triglycerides from the gut to the rest of the body. They are composed primarily of triglycerides, but also contain small amounts of cholesterol, phopholipid, and proteins in the form of apoproteins. They travel via lymphatics from the gut to the systemic circulation, where they are acted upon by lipoprotein lipases to release glycerol and free fatty acids to the tissues. Apolipoproteins are also removed from the chylomicron, leaving a chylomicron remnant, which is rapidly removed by the liver.

This member of the Enterobacteriaceae was isolated from a stool specimen and gave the following biochemical reactions: TSIA . .. . . . . . .K/A, no gas, no H2S Citrate . . . . . . . Positive Lysine . . . . . . . .Negative Ornithine. . . . . . .Positive Indole. . . . . . . . . Negative This organism agglutinated in Group D Shigella antiserum. Which biochemical result is NOT consistent with this identification? The correct answer is highlighted below TSIA Citrate Lysine Indole

Citrate is the correct answer. Shigella species are all citrate negative. A, C, and D are all consistent with an identification of Shigella sonnei.

Which of the following organisms are gram-positive? The correct answer is highlighted below Neisseria gonorrhoeae Brucella species Clostridium difficile Pseudomonas aeruginosa

Clostridium difficile is a gram-positive, spore-forming bacilli. The remaining organisms will all stain gram-negative on direct smear or smears made from culture.

Beta thalassemia major, is also known as: The correct answer is highlighted below Cooley's anemia sickle cell anemia sickle cell trait pernicious anemia none of the above

Cooley's anemia is a synonym for Beta thalassemia major.

What is the corrected WBC if a differential count shows 20 nucleated erythrocytes per 100 leukocytes and the uncorrected leukocyte count is 12,000/ mm3? The correct answer is highlighted below 1,000/ mm3 2,000/ mm3 10,000/ mm3 12,000/ mm3 14,000/ mm3

Corrected WBC count = uncorrected WBC count x 100 divided by # NRBCs (per 100 WBC) + 100 10,000

Which one of the following organisms is commonly cultured from the nasopharynx of healthy people but is RARELY pathogenic: The correct answer is highlighted below Beta hemolytic streptococci Corynebacterium species Haemophilus influenzae Neisseria meningitidis Staphylococcus aureus

Corynebacterium species is commonly cultured from the nasopharynx of health people but is rarely pathogenic. If a Corynebacterium species is thought to be causing respiratory illness, a throat swab and nasopharyngeal swab are recommended for collection to aid in the identification of this organism.

An automated method for measuring chloride which generates silver ions in the reaction is called: The correct answer is highlighted below Coulometry Potentiometry Chromatography Polarography Densitometry

Coulometry operates on the principle of Faraday's law in which a silver anode releases silver ions (titration) at a constant rate when a constant potential is applied. The silver ions react with chloride in a fixed volume of solution to form silver chloride. The time it takes for the chloride in the unknown solution to react with the silver ions is proportional to the chloride activity in the sample.

All of the following observations are consistent with the laboratory identification of Cryptococcus neoformansexcept: The correct answer is highlighted below Colonies that appear mucoid on primary isolation culture medium Negative urease test Cornmeal agar morphology displaying spherical, irregular cells with no pseudohyphae Presence of capsular material Tan-brown pigment on bird seed agar

Cryptococcus neoformans would produce a rapidly positive urease test. All the remaining observations are consistant with the laboratory identification of C. neoformans. Upon observing mucoid appearing colonies on a primary isolation culture medium, perform a rapid urease test and set up a cornmeal agar preparation. If the urease test is rapidly positive, observe the cornmeal agar morphology. If pseudohyphae are absent, and particularly if the yeast cells are spherical, irregular in size and widely separated (presence of capsular material), inoculate the surface of a bird seed agar plate with a small portion of the unknown colony. If a brown pigment is produced within 48-72 hours, a definitive identification of Cryptococcus neoformans can be made.

The light gray-white, border to border colony extension when recovered in clinical specimen is usually considered as a Zygomycete contaminant. In this exercise the recovery of this fungus may have been involved as a commensal in both skin and internal infections of patients with immune deficiency or who may have received recent chemotherapy or are post-surgery. The identification can be made by observing the fruiting bodies in the lactophenol blue mount illustrated in the photomicrograph to the right. From these observations, select from the multiple choice selections the name of this isolate. The correct answer is highlighted below Circinella species Cunninghamella species Syncephalastrum species Rhizopus species

Cunninghamella sp. is the correct response. The colony is consistent with one of the Zygomycetes. The identification is made by observing one of the fruiting heads as illustrated in the photomicrograph. Observed is a non-septate hypha terminating in a large globose phialide with lateral delicate branches giving rise to columella. Distinctive is the production of small, spherical conidia, called sporangiola, attached in loose clusters to each columella .

The organism pictured below was a Gram-positive rod isolated from a sore on the hand of a fish market employee. It is shown on triple sugar iron agar. What is the most likely identification if it is catalase negative and non-motile? The correct answer is highlighted below Listeria monocytogenes Bacillus anthracis Corynebacterium diphtheriae Erysipelothrix rhuziopathiae

D is the correct answer since Erysipelothrix rhuziopathiae is the only H2S positive, Gram-positive rod listed.

Review the descriptions of molecular testing techniques and select the correct statements. (Choose all that apply) The correct answers are highlighted below Renaturation is the process of converting double-stranded DNA to single strands Denaturation is the process of converting double-stranded DNA to single-stranded DNA Target amplification assays use methods to make more copies of a specific region of DNA In signal amplification methods, the target number increases as the signal is amplified

Denaturation uses processes that make double-stranded DNA single-stranded. Target amplification methods increase copies of target nucleic acid strands. In other amplification methods, target number is not changed; signal or probes are amplified.

For which of these reasons would a molecular method be used to determine a pregnant woman's Rh type? The correct answer is highlighted below To determine if she is homozygous or heterozygous for D To determine if she is Rh negative To differentiate between weak D or partial D

Differentiating between weak D and partial D is useful because women with partial D, but not usually weak D, may make anti-D and should be considered Rh negative for purposes of administering RhIg. Anti-D reagents cannot distinguish between the two D variants.

Which condition is caused by deficient secretion of bilirubin into the bile canaliculi? The correct answer is highlighted below Gilbert's disease neonatal hyperbilirubinemia Dubin-Johnson syndrome Crigler-Najjar syndrome

Dubin-Johnson syndrome is an autosomal recessive disorder that causes an increase of conjugated bilirubin without elevation of liver enzymes (ALT, AST). This condition is associated with a defect in the ability of hepatocytes to secrete conjugated bilirubin into the bile. Gilbert's syndrome causes an otherwise harmless jaundice, which does not require treatment, caused by hyperbilirubinemia. Neonatal hyperbilirubinemia is associated with jaundice and is a condition marked by high levels of bilirubin in the blood. Crigler-Najjar syndrome is associated with increased levels of bilirubin in the blood as the disorder affects the metabolism of bilirubin.

Enterobius vermicularis infection occurs through: The correct answer is highlighted below penetration of larvae through skin penetration of adult through skin an resulting production of larvae ingesting or inhaling ova ingesting a segment of the adult worm

Enterobius vermicularis infection occurs through swallowing ova. Pinworm infections including those caused by Enterobius vermicularis, usually occur due to a fecal-oral route of transmission. According to the CDC, "Eggs are deposited on perianal folds. Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area. Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. Enterobiasis may also be acquired through surfaces in the environment that are contaminated with pinworm eggs (e.g. , curtains, carpeting). Some small number of eggs may become airborne and inhaled. These would be swallowed and follow the same development as ingested eggs. Following ingestion of infective eggs, the larvae hatch in the small intestine and the adults establish themselves in the colon. The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. The life span of the adults is about two months. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area. The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under optimal conditions . Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown."

Estriol levels in conjunction with hCG and AFP can be obtained during pregnancy to: The correct answer is highlighted below Assess the risk of Down's syndrome Assess fetomaternal function Assess for multiple gestations Assess for maternal diabetes mellitus

Estriol "the estrogen of pregnancy" is synthesized by the placenta from precursor substances synthesized in the fetal adrenal, and modified in the fetal liver. Measuring of maternal serum estriol in conjunction with AFP and hCG during the 16th week of pregnancy can be used to help predict the risk of Down's syndrome (Triple Screen), although sometimes only hCG and AFP are used to assess this risk, since the addition of estriol to the screen is only marginally cost effective.

Which of the following Fresh Frozen Plasma ABO types would be suitable for transfusion to an AB negative patient? The correct answer is highlighted below AB negative only. O negative only. AB negative and AB positive only. O negative and O positive only. A or B

FFP should be ABO compatible with the patient's red blood cells. It can be given without regard to Rh type because it does not contain cells.

What weight of H2SO4 is contained in 200 ml of a 4 molar H2SO4 solution? (Atomic weight: H= 1; S = 32; 0 = 16) The correct answer is highlighted below 78.4 gm 156.8 gm 39.2 gm 15.68 gm 84 gm

Feedback x (grams needed) (4 M) (0.2 L) = 98 (formula weight) Therefore: x (grams needed) 0.8 = 98 (formula weight) = 78.4 g Molarity x Molecular Weight x Volume = Grams

Which of the following test results are NOT characteristic of disseminated intravascular coagulation (DIC)? The correct answer is highlighted below Decreased fibrinogen concentration Negative test for fibrin split products Decreased platelet count Prolonged Prothrombin time test

Fibrin split products (FSP) and d-dimers are fragments of protein released from a clot that has been broken down by fibrinolysis. In DIC, the coagulation cascade is triggered abnormally, resulting in the coagulation system being overwhelmed with excessive clotting and fibrinolysis taking place. This process of over clotting and over dissolving creates increased fibrin split products and d-dimers, the opposite of the choice above. Decreased fibrinogen levels, decreased platelet count, and prolonged PT tests are all associated with DIC and the consequences of over clotting and over dissolving.

Which type of electrophoresis is used to separate larger DNA fragments (>50 kb)? The correct answer is highlighted below electroimmunoassay electrophoresis capillary electrophoresis isoelectric focusing pulsed field electrophoresis

Fragments of DNA > 50 kb will not separate in most types of electrophoresis due to their large size. Special techniques are required; pulsed field electrophoresis is one type of electrophoresis that will separate these larger fragments.

One of the BIGGEST problems with isolating Francisella is that these organisms: The correct answer is highlighted below produce wide zones of hemolysis grow so slowly overgrow other organisms produce greenish colonies like E. coli

Francisella is slow growing on primary isolation culture media and produces poorly-staining coccobacilli on Gram stain. Because Francisella tularensis is included on the list of bioterrorism agents, suspicious isolates should be referred immediately to a public health laboratory in lieu of attempting an in-laboratory identification.

Which blood component is the most commonly used component for the replacement of multiple coagulation factor deficiencies in bleeding patients? The correct answer is highlighted below Fresh Frozen Plasma Red Blood Cells Cryoprecipitate Whole Blood

Fresh Frozen Plasma (FFP) is indicated for bleeding patients with multiple coagulation factor deficiencies due to inadequate production, as in liver disease; excessive consumption, as in disseminated intravascular coagulation (DIC); or dilution, as in massive transfusion, generally defined as the replacement of one or more blood volumes in a period of 24 hours or less. FFP is also indicated for non-bleeding patients with multiple deficiencies who are undergoing invasive procedures. FFP is also used for reversal of warfarin therapy in bleeding patients and for patients with congenital factor deficiencies for which no concentrates are available.

he BEST way to thaw Fresh Frozen Plasma is to thaw it by: The correct answer is highlighted below leaving it at room temperature away from agitation refrigerating the FFP on a bottom rack placing the FFP in a 37º C or lower in a water bath placing the FFP in a 121º C or higher in a steam sterilizer

Fresh frozen plasma must be thawed at a maximum of 37oC in a water bath or similar equipment that has been validated and is temperature monitored. When using a water bath, the FFP should be wrapped in a plastic liner. After thawing, it is recommended that the FFP be administered immediately, preferably within 2 hours post-thaw.

Which one of the following fungi is MOST likely to be found as a common saprobe and as a cause of keratitis? The correct answer is highlighted below Sporothrix schenckii Cladosporium Fusarium Alternaria

Fusarium can be found as a common saprobe and as a cause of keratitis. Fusarium colonies are most commonly fast-growing and may or may not have a cottony aerial mycelium. Fusarium typically produce both macroconidia and microconidia from thin phialides. Macroconidia and microconidia are both hyaline. Chlamydoconidia may or may not be present.

Which of the following factors may increase the likelihood of developing an autoimmune disease? (Choose all that apply) The correct answers are highlighted below Genetic predisposition Exposure to a triggering event Low birth weight Gender

Genetic predisposition may make some individuals more susceptible to development of an autoimmune disease. An event that triggers the body to perceive antigens as foreign may also lead to the development of an autoimmune disease. Another factor is gender; women are more likely to develop an autoimmune disease. There is no evidence that low birth weight would lead to development of an autoimmune disorder.

The tubes below are the Hugh and Liefson O/F basal medium with glucose and a pH indicator of bromthymol blue. The image below demonstrates a reaction of: The correct answer is highlighted below Glucose-fermenter Glucose-oxidizer Glucose non-oxidizer Sucrose-fermenter

Glucose non-oxidizer is the correct answer. There is no reaction in the tubes so the organism does not ferment or oxidize glucose. Stays green

he proper storage requirements for granulocyte concentrates is: The correct answer is highlighted below 1 - 6 degrees Celsius, < 12 hours - 20 degrees Celsius, 48 hours 1 - 6 degrees Celsius, < 24 hours 20 - 24 degrees Celsius, < 24 hours

Granulocytes may be stored at 20-24 degrees Celsius for up to 24 hours, but should be transfused as soon as possible.

What is the antigen carried by most strains of Streptococcus anginosus (milleri)? The correct answer is highlighted below A B F G

Group F is the most common Lancefield antigen detected (~47%), associated with S. anginosus (milleri)

How many out of 1,000,000 Caucasians will have the following phenotype: Group 0, K+, Jk(a+) The correct answer is highlighted below 10,000 30,000 100,000 600,000 750,000

Group O blood types comprise about 44% of the caucasian population. Out of 1,000,000 people, this leaves us with about 440,000 people. Approximately 9% of caucasians have the K antigen, leaving us with 39,600 individuals who are group O, K+. Approximately 77% of caucasians are positive for the Jka antigen. 77% of 39,600 individuals leaves us with 30,492 or approximately 30,000 individuals that are group O, K+ and Jk(a+).

Which is the first marker (antigen or antibody) which will become positive after exposure to Hepatitis B: The correct answer is highlighted below HBsAg Anti-Hbs Anti-Hbe Anti-HBc

HBsAg is the first hepatitis antigen to appear after infection. The first antibody produced after infection with HBV is anti-Hbc; used to detectpresent or past infection. Anti-Hbe is present in individuals who have recovered from acute hepatitis B infection. Anti-HBs becomes positive later, during the recovery period.

Why is hereditary hemochromatosis (HH) thought to be underdiagnosed? The correct answers are highlighted below Its early symptoms are nonspecific and vague. It is an extremely rare disease. Physicians and patients may lack knowledge of this disorder. It is a mild disorder and has no severe implications for one's health.

HH is thought to be underdiagnosed because it early symptoms are vague and nonspecific and there is lack of awareness of HH on the part of patients and physicians.

What is the role of microalbuminuria testing? The correct answer is highlighted below Monitor diabetic patient carbohydrate management Detect small-sized urinary albumin molecules in early renal disease Detect small urinary concentrations of albumin before there is irreparable renal damage Diagnose renal failure in a type 1 diabetic patient

HbA1C is the recommended test for monitoring diabetic carbohydrate management. Microalbuminuria, low concentrations of urinary albumin, is measured to detect early renal impairment, at a stage where it is reversible with treatment.

In which of the following conditions is Hgb D elevated? The correct answers are highlighted below Hemoglobin D disease Hemoglobin SD disease Hb D/beta-thalassemia Hemoglobin CD disease Alpha thalassemia

Hemoglobin D is an inherited autosomal recessive variation of Hb A that occurs in the β-globin protein chain of Hb A. The formation of Hb D occurs by substitution of glutamic acid for glutamin at codon 121 of the β-chain. Hemoglobin D disease, also known as Hb DD, occurs when two copies of the Hb D variant gene are inherited. It is also possible to inherit a condition known as Hb D/beta-thalassemia (Hb D/β-thal). Hemoglobin CD disease does not exist and alpha thalassemia would not show an increase in hemoglobin D.

This image depicts a brilliant cresyl blue stained blood smear. Which arrow points to a cell that contains hemoglobin H bodies?

Hemoglobin H bodies precipitate just inside the RBC membrane and are usually lightly colored and evenly distributed around the cell. Normal hemoglobin, or that which has not yet precipitated, remains evenly distributed in the RBC giving it a smooth appearance. Brilliant cresyl blue that is used for this stain also precipitates remnants of RNA (similar to New methylene blue in the reticulocyte stain). These RNA remnants stain darker than Hemoglobin H bodies and are few in number.

The hematology laboratory is experiencing instrument downtime. The laboratory has a back-up method for hemoglobin and hematocrit testing that is being used until the instrument is repaired. The hematologist calls and asks if you can provide any of the red blood cell indices. Which of the indices, if any, can you provide for the hematologist? The correct answer is highlighted below MCV and MCH MCH and MCHC MCH only MCHC only MCV, MCH and MCHC

Hemoglobin and hematocrit are required to calculate the MCHC. Since both of these values are available from the backup instrument, MCHC can be calculated. Red blood cell (RBC) count and hemoglobin are required to calculate the MCH and RBC and hematocrit are required to calculate the MCV. Since RBC count is not available during the downtime, MCH and MCV cannot be calculated.

Which of the following antigen groups is closely related to the ABO antigens on the red cell membrane? The correct answer is highlighted below Rh Kell I, i Duffy

I and i antigens are related biochemically and spatially to the ABH and Lewis antigens on the red cell membrane. Anti-I is usually an autoantibody. It is common as a benign cold autoagglutinin. Strong anti-I is associated with Mycoplasma pneumonia infection, where it may be associated with cold autoimmune hemolytic anemia. Anti-I is characterized by its failure to react with cord red cells. Anti-i generally occurs as a cold reactive IgM antibody in the setting of infectious mononucleosis.

Which adipokine is synthesized and released by adipocytes and many other body cell types, is an inflammatory cytokine that stimulates the liver to produce C-reactive protein (CRP), and is increased in obesity and insulin resistance? The correct answer is highlighted below Leptin IL-6 Adiponectin Angiotensinogen

IL-6

Which of these factors may be deficient if both the PT and aPTT are prolonged? The correct answer is highlighted below Factor II Factor VII Factor VIII Factor XI

If both the PT and aPTT are prolonged, one or more factors in the common pathway may be deficient. Factor II is in the common pathway along with factors I, V, and X. Factors VIII and XI are intrinsic pathway factors. If either of these factors were deficient, the aPTT would be prolonged, but the PT would be normal. Factor VII is monitored by the PT test. If factor VII were deficient, the PT would be prolonged, but the aPTT would be normal.

The rheumatoid factor in rheumatoid arthritis is PRIMARILY which type of immunoglobulin? The correct answer is highlighted below IgM IgA IgG IgE Incomplete

IgM

Which of the following blood group system antibodies is the direct antiglobulin test (DAT) most UNRELIABLE in helping to diagnose hemolytic disease of the fetus and newborn (HDFN)? The correct answer is highlighted below ABO Duffy Kell Kidd Rh

In ABO HDFN, the DAT may be weakly positive or negative, making it an unreliable test. The DAT is usually reliable for antibodies in the other listed blood group systems that cause HDFN.

In which of the following condition(s) would an increased serum osmolality be an expected finding? The correct answers are highlighted below Dehydration Hyponatremia Increased ADH secretion Diabetes Insipidus

In dehydration, the decreased volume of body water causes a subsequent rise in serum osmolality. In diabetes insipidus, renal insensitivity to vasopressin results in the excretion of an increased volume of dilute urine, a decrease in body water, and a rise in serum osmolality. In hyponatremia and when ADH is abnormally secreted, the serum osmolality values can be expected to decrease.

A patient has an initially prolonged PT. After reviewing the patient's case and laboratory findings, the physician administers intravenous vitamin K. The repeat PT results are normal after 24 hours of vitamin K therapy. What clinical condition(s) is/are MOST likely to produce these results? The correct answer is highlighted below Liver disease Inherited Factor X deficiency Obstructive jaundice A, B, and C A and C

In liver disease, vitamin K deficiency results from decreased bile salt synthesis leads to impaired vitamin K absorption and deficiency. In obstructive jaundice, vitamin K deficiency can result from impaired intestinal absorption. Therefore, both A and C are correct. Inherited factor X deficiency does not correct with vitamin K treatment.

During which stage in real-time PCR can the fluorescent signal start to be recorded? The correct answer is highlighted below Plateau stage Exponential stage Leveling stage

In real-time PCR the fluorescent signal is generally too low to detect until after the first couple of cycles. However, detection usually occurs before the end of the exponential stage.

What is the probable identity of an organism isolated from a wound culture that demonstrates the following test results? Phenylalanine Deaminase = negative TSI = A/A gas Citrate = positive Lysine = positive SIM = negative/negative/negative Urea = weakly positive The correct answer is highlighted below Escherichia coli Klebsiella pneumoniae Enterobacter aerogenes Proteus vulgaris Salmonella spp.

In this case, Klebsiella pneumoniae is the best choice:

A 68 year old woman presents with pressure under the lower left ribs from a swollen spleen, but is not complaining of any other symptoms. Her laboratory data showed the following: Hgb = 13.5 g/dL Hct = 40% Platelets = 240 x 109/L WBC count = 46 x 109/L Differential: 45% Neutrophils, 2% Lymphocytes, 6% Eosinophils, 2% Basophils, 35% myelocytes, 10% metamyelocytes LAP score: 11 The correct answer is highlighted below Leukemoid Reaction Chronic Myelogenous Leukemia Acute Myelogenous Leukemia Polycythemia Vera

In this case, the correct answer is Chronic Myelogenous Leukemia, or CML. CML is highly associated with a low LAP score, white blood cell immaturity, and a higher than normal white blood cell count. In the beginning stages of CML, patients often do not display many symptoms which helps to differentiate it from acute leukemias. It could not be a leukemoid reaction due to the low LAP score present. In addition, polycythemia vera can be ruled out with the cell counts shown.

In tissues infected with Histoplasma capsulatum, which of the following is usually true? The correct answer is highlighted below hyphae usually invade blood vessels encapsulated yeast cells are typical conidiophores with metulae and phialides are typical fungus is usually intracellular

In tissues infected with Histoplasma capsulatum, the fungus is usually intracellular. Microscopic morphology of Histoplasma capsulatum can be described as large, round, single-celled macrocondidia with microconidia present on hyphae. According to the CDC, " Histoplasma capsulatum, a dimorphic fungus that causes human disease, is endemic in North and Central America, particularly in the region of the Ohio and Mississippi River valleys. Humans are infected by inhalation of the mycelial fragments and microconidia of the organism."

RhIg prevents anti-D production mainly by clearing antibody-sensitized D-positive rbc from maternal circulation. The correct answer is highlighted below True False

Initially researchers thought that RhIg prevented anti-D production by clearing the infant's D-positive rbc sensitized with maternal anti-D, but we now know this is not true. Currently, the mechanism by which RhIg prevents immunization to the D antigen is poorly defined. However, research shows that it likely involves down-regulation of antigen-specific B cells, ie., the B cells do not differentiate into antibody-excreting plasma cells as they normally would when presented with foreign antigens.

A 56 year old female was taken to the emergency room in a coma by her employer's nurse. She had lost 35 pounds in 3 months; she was always thirsty; drinking a lot of water and running to the bathroom. The following are her laboratory results: Results: (indicates reference range) pH: 7.11 (7.35-7.45) pCO2: 21 mm Hg (35-45 mm Hg) Glucose: 950 mg/dL (60-110 mg/dL) Serum osmolality: 365 mOsm/Kg (275-295 mOsm/Kg) Urine ketone: strongly positive (negative) Urine glucose: strongly positive (negative) What is the MOST likely cause of this patient's symptoms? The correct answer is highlighted below gestational diabetes diabetes insipidus insulin dependent diabetes mellitus type II diabetes mellitus

Insulin dependent diabetes mellitus is associated with a lack of insulin, which leads to increased blood and urine glucose. The classical symptoms of polyuria (frequent urination), polydipsia (increased thirst), polyphagia (increased hunger), and weight loss. Since this patient had not been diagnosed and appears to be poorly controlled, she developed hyperosmotic non-ketotic coma (HONK) which lead to her acidosis and elevated osmolality. The ketones and glucose in the urine indicate that the body is not able to use the glucose present, since there is a lack of insulin, and that the body is using fat for its source of energy instead. Gestational diabetes occurs in pregnant women and would not cause the laboratory results shown here. In addition, gestational diabetes since it would be very unlikely that a 56-year-old would be pregnant. Diabetes insipidus is a condition where the body is unable to reabsorb water in the kidneys. This type of diabetes is associated with an increased thirst and cravings for ice, along with very high volumes of diluted urine. However, diabetes insipidus can be ruled out due to the presence of glucose in the urine. Diabetes insipidus patients usually do not exhibit positive urine glucose results. Those suffering from type II diabetes mellitus do not typically show ketosis. Type II diabetes mellitus is usually not associated with ketonuria or ketoacidosis. Therefore, the best choice in this case is insulin dependent diabetes mellitus.

The lymphokine most important for increased natural killer cell activity and decreased viral replication in cells is: The correct answer is highlighted below Interferon gamma Interleukin 3 Interleukin 4 Interleukin 5

Interferon gamma serves various purposes in immunologic response, including the promotion of natural killer cell activity as well as decreased viral replication by using enzymes to decrease protein replication, both viral or host, inside of the cell.

In order to identify an isolate as Yersinia enterocolitica, it must be lysine-negative and: The correct answer is highlighted below K/A on Kligler's iron agar Agglutinate in O polyvalent antisera Grow on XLD agar as a red colony with black centers Produce gas from glucose

K/A on Kligler's iron agar is the correct answer. Although Yersinia enterocolitica is A/A on TSIA, it ferments sucrose which is not present in Kligler's iron agar. Antisera typing is required to identify Salmonella and Shigella but not Yersinia enterocolitica. Salmonella is a red colony with black centers on XLD. Yersinia enterocolitica is not identified on the basis of gas production.

What would be the logical first step to obtain correct values when the following results were obtained on an electronic particle counter in hematology for an alcoholic patient? WBC 6,500/cu. mm MCV 90.1 fL RBC 4,550,000/cu. mm MCH 39.6 pg HGB 18.0 g/dl MCHC 43.4% HCT 41.5% The correct answer is highlighted below Perform a microhematocrit Check and correct for lipemia Dilute the blood Replace the lysing agent

Lipemia can cause increased hemoglobin results on automated hematology analyzers since the hemoglobin measurement is performed spectrophotometrically. The lipemia in the sample causes a more turbid sample, leading to a falsely high reading during the hemoglobin determination.

Substances found in urinary sediment that are more easily distinguished by use of polarized microscope are: The correct answer is highlighted below WBC RBC Casts Lipids Crystals

Lipids tend to form a "maltese cross" pattern when viewed in polarized light, which helps to differentiate them from other urine microscopic components.

A ten-year-old boy came to a physician's attention because of recent jaundice and icteric sclerae after taking the medication Primaquine before a trip to Africa. The immediate laboratory work revealed: Hct 24%(normal 36%-47%), MCV 79.5 fl (normal 78-95fl),RDW 13%(normal 11.5-15.0%). His blood smear findings are reflected in the images to the right. The upper image is a Wright-Giemsa stained smear while the lower is a supravital-stained smear. Which condition should be considered for this patient when analyzing his symptoms, history, and laboratory results? The correct answer is highlighted below G6PD deficiency Pyruvate kinase deficiency Iron deficiency anemia Megaloblastic anemia

Note particularly the spherocytes in the upper image to the right. Some resemble a half-blister with the other half of the cell containing solidly-staining hemoglobin. These are called eccentrocytes. When present, along with a suspicious patient history, they should trigger an evaluation for G6PD deficiency. Upper image: The blue arrows in the upper photomicrograph are directed toward solid-staining spherocytes in which the cell membrane is beaded by inclusions wrapped within the cell membrane, suggesting the remains of denatured hemoglobin. Included on the smear is a target cell, several acanthocytes, a smudge cell, and a few schistocytes. Lower image: This is a supravital staining of the affected red blood cells, confirming the presence of Heinz bodies, a key diagnostic feature of this condition. Pyruvate kinase deficiency is associated with a normocytic, normochromic anemia with poikilocytosis and anisocytosis, but Heinz bodies are not found in this condition. Iron deficiency anemia is assoicated with a microcytic, hypochromic anemia and is not associated with the presence of Heinz bodies. Finally, megaloblastic anemia is considered a macrocytic, normochromic anemia associated with abnormal red blood cell development. This condition is also not associated with the presence of Heinze body inclusions.

Pheochromocytoma is a tumor of the adrenal medulla that results in elevated urinary levels of all the following EXCEPT: The correct answer is highlighted below Cortisol Free catecholamines Metanephrines Vanillylmandelic acid

Of the choices that are given, cortisol is the only analyte that is not elevated in the urine. Pheochromocytoma is an adrenal or extraadrenal neoplasm that secretes catecholamines. Patients with pheochromocytoma often exhibit persistent and paroxysmal hypertension. The single best screening test is urinary metanephrines. Urinary free catecholamines, and vanillylmandelic acid are also elevated.

Match the names of each of the fungi listed with its appropriate category indicating the degree of pathogenicity. Your answers are on the left. The correct answers are on the right and highlighted. Usually not pathogenic Alternaria species Usually pathogenic Fonsecaea pedrosoi Usually pathogenic Phialophora verrucosa Usually not pathogenic Bipolaris species

Of the fungi listed in this exercise, Fonsecaea pedrosoi and Phialophora verrucosa, each serving as agents of chromomycosis, are generally considered "pathogenic" species. Alternaria species and Bipolaris species are usually not pathogenic, but may cause opportunistic infections in debilitated patients, commonly sinusitis from the inhalation of spore-laden dust; or, subcutaneous mycetomas where spore-infected vegetative material has been traumatically inoculated into the skin.

Which specific terminal sugar causes a red cell to have A antigenic activity? The correct answer is highlighted below Galactose plus glucose Galactose N-acetylgalactosamine Glucose

Once substance H is developed, the addition of the sugar N-acetylgalactosamine to the terminal position of the chain gives the molecule "A" antigenic activity.

Which are true statements regarding hospital-associated methicillin-resistant Staphylococcus aureaus (HA-MRSA) and community-associated MRSA (CA-MRSA)? The correct answer is highlighted below Resistance for both strains is conferred by the mecA gene. HA strains tend to demonstrate resistance to more drug classes than CA strains. CA tends to be associated with the PVL gene and skin and soft tissue infections. All of the above.

PBP2a, which has a reduced binding affinity for beta-lactams, and remains active in cell wall synthesis even in the presence of beta-lactam antibiotics, is coded by the mecA gene. Both HA and CA strains of MRSA possess the mecA gene, although CA strains typically possess a smaller variant of that gene. CA strains may be susceptible to some antibiotics that HA strains are resistant to. CA strains are also associated with the PVL gene, which code for enzymes that produce tissue necrosis and leukocyte destruction.

The growth seen here on PPLO agar is most likely caused by: The correct answer is highlighted below Streptococcus pneumoniae Klebsiella pneumoniae Mycobacterium Mycoplasma

PPLO agar is used for the isolation and cultivation of Mycoplasma species.

Estrogen and progesterone markers are most commonly used to provide prognostic information about: The correct answer is highlighted below Breast cancer Uterine cancer Menopause Cervical cancer

Patients with tumors positive for both estrogen and progesterone receptors tend to respond favorably to hormonal therapy, whereas those without generally do not. Patients with positive estrogen and progesterone receptors also have a somewhat better prognosis.

The term pharmacokinetic BEST describes: The correct answer is highlighted below What the drug does to the body Concentration of drug at its sites of action What the body does to the drug None of the above answers are correct.

Pharmacokinetics describes what the body does to a drug after it has been introduced into the body; specifically describing absorption, distribution, chemical changes, excretion, etc. Pharmacodynamics describes what the drug does to the body in terms of physiological response.

The positive phenylalanine reaction seen in the left tube (green pigmentation in the slant compared to the negative control on the right) may be produced by each of the following bacterial species except: The correct answer is highlighted below Proteus vulgaris Serratia marcescens Morganella morganii Providencia stuartii

Phenylalanine deaminase is a key reaction for the presumptive identification of members of the Proteus/Providencia genera of the Family Enterobacteriaceae. Members of the genus Morganella, formerly classified in the genus Proteus, also possess this capability. Therefore, of the responses in this exercise, only Serratia marcescens does not have the capability of converting phenylalanine to phenylpyruvic acid.

Which of the following conditions would be suggested by a jaundiced patient experiencing a marked rise in alkaline phosphatase, conjugated bilirubin, and a slight rise in ALT: The correct answer is highlighted below Cardiovascular disease Hepatitis Post-hepatic obstruction Renal failure

Post-hepatic obstruction is characterized by a marked increase in alkaline phosphatase, GGT, conjugated bilirubin, as well as other hepatic enzymes. The slight rise of ALT suggests that the issue is not hepatitis. Renal and cardiovascular failure do not match the symptom of jaundice or the abnormal laboratory values.

Pseudomonas aeruginosa is often used as a bacterial species for the quality control of Kligler Iron Agar. The expected reaction is: The correct answer is highlighted below Acid slant/acid deep Alkaline slant/acid deep Alkaline slant/acid deep/H2S Alkaline slant/alkaline deep

Pseudomonas aeruginosa is a nonfermenter; therefore, cannot produce acid from glucose in a fermentative medium. Therefore, there is no change in the KIA tube and both the slant and the deep remain alkaline (red). E. coli, a lactose fermenter, is used as the control organism to visualize the acid slant/acid deep reaction; Shigella flexneri, a non lactose fermenter to visualize the alkaline slant/acid deep reaction, and Salmonella typhimurium is used to detect the alkaline slant/black deep (production of H2S) reaction.

The granular, wrinkled, yellow-pigmented colonies shown in the upper photograph were recovered on chocolate agar after 48 hours of incubation from a respiratory specimen collected from a patient with cystic fibrosis. Note in the lower composite photograph that colonies on the surface of blood agar are flat, granular, and only slightly wrinkled. Colonies are gray white on MacConkey agar indicating lack of pyocyanin production. The spot oxidase test is positive, and nitrates are reduced. With these observations, select from the multiple choices the presumptive identification of this isolate. The correct answer is highlighted below Pseudomonas stutzeri Burkholderia cepacia Comamonas acidovorans Acinetobacter baumannii

Pseudomonas stutzeri is the correct response. Colonies on blood agar are spreading, convex and wrinkled with a yellow-white pigmentation. Colonies on MacConkey agar are gray white characteristic of a non-fermenter and devoid of the green pigmentation indicating lack of pyocyanin production. The gram stain reveals long gram negative bacilli in a picket fence arrangement comparable to P. aeruginosa, with most other biochemical characteristics, including a positive oxidase reaction also being comparable. Characteristic of P. stutzeri is reduction of nitrates with production of gas, and resistance to Polymyxin B. Burkholderia cepacia colonies are relatively small, entire, convex and smooth devoid of "wrinkles", with gray yellow pigmentation. Colonies on MacConkey agar are non-pigmented characteristic of a non-fermenter and negative for pyocyanin production. The oxidase reaction is positive; however, nitrate denitrification is negative and gas is not produced. Comamonas acidovorans colonies are tiny, entire, slightly raised smooth, without "wrinkles", with a light yellow pigmentation. The oxidase test is positive and nitrites are reduced, but without the production of gas. Colonies on MacConkey agar are also tiny and without pigmentation, ruling out pyocyanin production. Gram stains reveal straight and slightly curved gram negative bacilli arranged singly or in pairs. C. acidovorans is classified as an asaccharollytic pseudomonad, with only weak reactions in OF fructose and mannitol fermentation. Acinetobacter baumannii colonies are white, entire, convex and smooth without wrinkles on blood agar. Colonies growing on MacConkey agar are entire, smooth to finely wrinkled, with a light pink pigmentation, devoid of pyocyanin production. The oxidase reaction is negative. Gram stain reveals small, spherical gram-negative bacilli lying singly and in loose clusters, in contrast to the long, narrow, picket fence arrangement of gram negative bacilli characteristic of Pseudomonas species.

Which of the yeasts listed below is known as brewer's or baker's yeast? The correct answer is highlighted below Rhodotorula rubra Cryptococcus albidus Saccharomyces cerevisiae Hansenula anomala

Saccharomyces cerevisiae is known as brewer's or baker's yeast, as it is used in the fermentation stages of beer and bread making. None of the other yeasts that are listed are used in beer or bread making.

Which of the following species of hyaline molds produce conidia in chains? The correct answer is highlighted below Scopulariopsis species Gliocladium species Acremonium species

Scopulariopsis species develop conidia in chains, while the conidia of Gliocladium species and Acremonium species are gathered in tight and loose clusters respectively.

An acid-fast bacillus is isolated and produces an orange pigment when grown in either the light or the dark. Which type of organism has most likely been isolated? The correct answer is highlighted below photochromogen scotochromogen BCG Mycobacterium tuberculosis non-pathogenic

Scotochromogens produce deep yellow to orange pigmented colonies when grown in either the light or dark.

Which of the following best defines "sensitivity": The correct answer is highlighted below The percentage of patients with a disease who will have a positive test The percentage of patients without a disease who will have a negative test The percentage of patients with a disease who will have a negative test The percentage of patients without a disease who will have a positive test

Sensitivity refers to the percentage or fraction of patients with a given disease in a given population who will have a positive test.

Serum calcitonin is typically elevated in which of the following conditions: The correct answer is highlighted below Medullary carcinoma of the thyroid Hyperthyroidism Glioblastoma Adrenal adenoma

Serum calcitonin is normally produced by the C cells of the thyroid. It functions to reduce serum calcium by inhibiting release of calcium from bone. It is a peptide with a molecular weight of 3400, and has a half life of approximately 12 minutes. It is characteristically elevated in medullary carcinoma of the thyroid. Since medullary carcinoma often occurs as an autosomal disorder, family members of patients with this condition should be screened for serum calcitonin.

Among the nonfermenters, the only bacterial species to produce H2S is: The correct answer is highlighted below Chryseomonas luteola Commamonas acidvorans Shewanella putrifaciens Chromobacterium violaceum

Shewanella putrifaciens The combination of a bacterial species that does not change the color of KIA or TSI agar slants but produces H2S is presumptive evidence for Shewanella putrifaciens (formerly in the genus Pseudomonas). None of the other species listed produces H2S. Chryseomonas luteola produces yellow pigmented colonies and will produce a black pigment in esculin agar. Commamonas acidivorans does have one pigment related characteristic, the production of an orange reaction in tryptone broth upon addition of Kovac's reagent, from the production of anthranilic acid rather than indole. The darkly pigmented colonies of Chromobacterium violaceum may have the appearance of H2S production. However, the dark violet black pigment is a dye produced by the organism, and the colonies are pigmented even when growing on culture media devoid of H2S detecting reagents.

The heterozygous state of HbS that is referred to as sickle cell trait contains which of the following hemoglobins in combination with S? The correct answer is highlighted below HbE HbA HbC HbD

Sickle cell trait is HbSA.

A three-year-old boy was brought unconscious to the emergency room. Blood gas results were as follows: pH: 7.07 pCO2: 90 mm Hg HCO3: 23 mEq/L This patient is most likely suffering from: The correct answer is highlighted below Metabolic alkalosis Metabolic acidosis Respiratory acidosis Respiratory alkalosis uncompensated metabolic alkalosis

Since the blood pH is only 7.07, it is acidic. The increased level of pCO2 demonstrates that there is a build up of acid from the respiratory system, while the bicarbonate is within normal range. Therefore, the patient is suffering from respiratory acidosis.

If an Rh group (DCe/dce) man marries an Rh group (dce/dce) woman, what is the probablitiy that their first child will be D-negative? The correct answer is highlighted below 0% 25% 50% 75% 100%

Since the inheritance pattern of the D-antigen is determined equally from the mother's and father's genotypes, the chances of producing a D-negative offspring is 50%. DCe (father) + dce (mother) = D positive dce (father) + dce (mother) = D negative

Bacitracin susceptibility is useful for which two of the following: The correct answers are highlighted below Distinguishing Staphylococci from micrococci Presumptive identification of Group A streptococci Identification of Haemophilus Identification of Neisseria

Staphylococci are resistant to bacitracin while micrococcus are sensitive. Group A beta-hemolytic Streptococci are sensitive to bacitracin, while most other Groups are resistant.

Complete hemolysis of sheep blood agar as demonstrated by the image below would be seen in which of the following catalase-negative isolates? The correct answer is highlighted below Streptococcus pneumoniae Streptococcus pyogenes Staphylococcus aureus Streptococcus agalactiae

Streptococcus pyogenes is the correct answer. Streptococcus pneumoniae is alpha-hemolytic which demonstrate a green area of partial hemolysis around the colonies. Staphylococcus aureus will produce complete hemolysis but is catalase positive. Streptococcus agalactiae is beta-hemolytic but only produces a partial clearing of the red blood cells in sheep blood agar.

The 5' end of a DNA strand ends with a OH group. The correct answer is highlighted below True False

The 5' end of a DNA strand is distinguished by a phosphate while the 3' end is distinguished by a OH group.

The ADA recommends performing an oral glucose tolerance test (OGTT): The correct answer is highlighted below On all individuals who are at increased risk for diabetes. On all children under 5 years old On all pregnant patients None of the above

The ADA recommends regular screening for individuals who are at increased risk for diabetes. OGTT use is discouraged for these individuals unless blood glucose and HbA1C concentrations remain below diagnostic ranges for diabetes but patient displays symptoms of diabetes.

A patient has the following test results: ANA = positive 1:320 RA = positive Complement = decreased The above results would be seen in patients with: The correct answer is highlighted below rheumatic fever rheumatoid arthritis lupus erythematosus glomerulonephritis lyme disease

The ANA test, or anti-nuclear anitbody, is a screening test used to detect lupus erythematosus. In this case the ANA test was positive. The RA test, or rheumatoid factor, screens for the presence of an antibody linked with rheumatoid arthritis and other conditions such as lupus erythematosus. Again, in this case, the RA test was positive. Finally, a decrease in complement proteins indicates that the classic pathway may have been activated resulting in immune complexes, a clinically significant symptom of lupus erythematosus.

Which of the following antibodies is detected primarily in the antiglobulin phase of the crossmatch: The correct answer is highlighted below Anti-Fya Anti-M Anti-B Anti-P1

The Duffy system consists of Fya and Fyb. Antibodies to these antigens are IgG and are detected in the antiglobulin phase. Anti-M, Anti-B and Anti-P1 are typically IgM antibodies and may agglutinate saline suspended cells at room temperature.

Twelve weeks after onset of the disease, patients with uncomplicated acute hepatitis B usually will demonstrate which of the following in their serum? The correct answer is highlighted below HBsAg Anti-HTLV Anti-HBe Anti-HIV

The Hepatitis B e-antigen, or HBeAg is a viral protein associated with HBV infections. Unlike the surface antigen, the e-antigen is found in the blood only when there are viruses also present. Anti-HBe is an antibody produced in response to the Hepatitis B e antigen. In those who have recovered from acute hepatitis B infection, anti-HBe will be present along with anti-HBc and anti-HBs.

Blood samples for complete blood counts are collected on morning rounds and stored in a rack in the phlebotomist's basket. When the phlebotomist delivers the samples to your work station, the cells and plasma in the samples have separated. One of the samples has lipemic plasma. Which of the following parameters may be affected by the lipemia? The correct answer is highlighted below RDW MCV MCHC None of the parameters would be affected

The MCHC may be affected by lipemia as well as hemolysis, and red cell agglutination. The photometric measurement of the hemoglobin may be affected by the lipemia, which would then impact the MCHC calculation. MCV is a measurement of red cell volume and not impacted by lipemia. RDW is a measurement of red cell size and not impacted by lipemia.

Which of the following antibodies can be enhanced using enzyme panels during antibody identification in the blood bank? The correct answers are highlighted below Rh Lewis Kidd Duffy Lutheran Kell

The Rh system antibodies along with Lewis and Kidd blood group antibodies can show an enhanced reaction when analyzed with enzyme treated panels. The antibodies which can be destroyed or weakened by enzyme treated panels are: the MNS group (though s can be variable), Duffy, and Xga.

A patient's electrolyte results are the following: Sodium = 145 mmol/L Chloride = 113 mmol/L Bicarbonate = 24 mmol/L Calculate the anion gap for this patient and choose the correct answer below. The correct answer is highlighted below 32 mmol/L 8 mmol/L 27.7 mmol/L 3.7 mmol/L

The anion gap, which is typically uses to evaluate an instrument's analysis process, is calculated with the following formula: Anion Gap = Sodium - (Chloride + Bicarbonate) In this case, the calculation would be: Anion Gap = 145 - (113 + 24) = 8 mmol/L *Normal Range for Anion Gap = 10-20 mmol/L

What must be true for the antiglobulin phase of the serologic crossmatch to be omitted (i.e., immediate spin crossmatch is done)? The correct answers are highlighted below The antibody screen must be negative. The patient has not been transfused within the past 24 hours. There is no history of detection of unexpected antibodies The blood is needed for surgery

The antiglobulin test may be omitted from the serological crossmatch if the patient's antibody screen is negative and there is no history of detection of unexpected antibodies.

Calcium and phosphorus levels were determined for a 4-year-old patient as follows: Ca - 14mg/dl Phosphorus - 1mg/dl These results are MOST compatible with: The correct answer is highlighted below hyperparathyroidism renal failure rickets hypervitaminosis hypothyroidism

The calcium is elevated (child N = 8.8 - 10.8 mg/dL). The main cause of hypercalcemia is almost always over activity in one or more of the parathyroid glands, which regulate calcium. The phosphorus level is decreased (child N = 3.2 - 5.8 mg/dL). High calcium levels usually result in decreased phosphorus levels. Hypervitaminosis can lead to elevations in calcium, but since this is a child that scenario is not likely.

Calculate the specificity for the following medical research project completed by a manufacturer: Test Results Positive Negative Disease: 984 7 No Disease: 16 873 The correct answer is highlighted below 98.2%. 98.4%. 99.1%. 99.3%. 99.99%

The calculation for specificity is as follows: True negatives / (True negatives + False positives) In this question the calculation is: 873 / (873 + 16) = 0.982 0.982 x 100 = 98.2% specificity

An 8 year old boy underwent a laparotomy for clinical signs and symptoms of acute appendicitis. Instead, the appendix did not appear inflamed, but the mesenteric lymph nodes were enlarged and edematous. The photomicrograph is a close-in H & E section of an area within one of the lymph nodes, showing hyperplasia and focal necrotizing inflammation. The bacterial species most likely causing this reaction is: The correct answer is highlighted below Citrobacter freundii Shigella sonnei Yersinia enterocolitica Enteroinvasive Escherichia coli

The clinical syndrome described in the question is characteristic of the mesenteric adenitis in children and young adults caused by Yersinia enterocolitica and Yersinia pseudotuberculosis. It is not uncommon for this infection to clinically simulate acute appendicitis. The invasive potential of Yersinia species is plasmid-mediated and has been demonstrated in mouse models and in HeLa tissue culture cells (Kay, et al: J Clin Microbiol 17:128-138, 1983). Shigella species and enteroinvasive strains of E. coli can penetrate the intestinal epithelium and reach the lamina propria; however, the infection does not extend into the mesenteric lymph nodes. Citrobacter freundii has not been incriminated in this syndrome.

Which term listed below refers to the procedures that must be followed by a transfusion service when notification is received that a donor of a unit sent to the service now tests positive for an infectious disease? The correct answer is highlighted below A. Lookback B. Retrospective review C. Donor notification

The correct answer is A. Recipients of any products identified in the lookback process must be notified when a donor of a unit that they received now tests positive for an infectious disease. Donor notification includes regulations for notification of donors that they currently test positive for an infectious disease. Retrospective review refers to a review of any previous records.

An 8 year old boy presents with a 2 week history of high fevers and lethargy. He has shown petechiae and bleeding gums for approximately 3 weeks. Upon physical examination, the following was noted: Enlarged cervical lymph nodes, Pale and febrile, Enlarged spleen. His laboratory results were the following: Hgb = 6.3g/dl Hct = 18.9% RBC count = 2.89 x 109/L WBC Count = 96 x 109/L Platelet count = 23 x 109/L Differential: 90% blasts, 5% bands, 5% neutrophils BM aspirate > 90% blasts What is this patient most likely suffering from? The correct answer is highlighted below Polycythemia vera Chronic Leukemia Acute Leukemia Infectious Mononucleosis

The correct answer is acute leukemia. Acute leukemia is associated with bone pain, hepatosplenomegaly, and swollen lymph nodes. In addition, infections (causing fevers) and bleeding are common. A high white blood cell count with many blasts in the peripheral blood and bone marrow, along with a low platelet and rbc count are also highly associated with this condition.

A phlebotomist at a local hospital recently had an accidental needle stick while drawing blood from a patient being treated for acute hepatitis B. Which serological marker from the patient would be of most value to the physician evaluating the phlebotomist's possible infection status? The correct answer is highlighted below Hepatitis B surface Antigen (HBsAg) Hepatitis B e Antigen (HBeAg) Hepatitis B core Antigen (HBcAg) Anti-Hepatitis B e (anti-HBe) IgM Anti-Hepatitis B core (anti-HBc) IgG

The correct response is option B: The Hepatitis B "e" Antigen (HBeAg). This antigen indicates the virus is actively replicating and therefore the patient is very infectious. The hepatitis B "e" antigen is present when the virus is actively replicating. In cases of unintentional needlesticks, infectivity is of highest concern. The risk for infection is greatest during phases of increased HBeAg serology. The Hepatitis B surface antigen is the first detectable marker, but if the patient is known to have Hepatitis B already, it would be relatively unhelpful to confirm the condition with another HBsAG test. The core antigen is not detectable because it is covered by the nuclear envelope. Antibody response patterns would not be very helpful either as the patient has already been diagnosed with acute Hepatitis B. IgG antibodies would indicate recovery, which is not the case for this patient and IgM antibodies indicating a recent or acute infection would only confirm what is already known. Recall, in cases of unintentional needlesticks, infectivity is of highest concern.

Which one of the following proteins in cerebrospinal fluid (CSF) is used to monitor the integrity of the blood-brain barrier? The correct answer is highlighted below albumin prealbumin transferrin IgG total protein Feedback The degree of permeability of the blood-brain barrier is evaluated by measuring the CSF albumin and comparing it with the serum albumin. Albumin is usually used as the reference protein for permeability because ordinarily it is not found to any great extent in the central nervous system.

The degree of permeability of the blood-brain barrier is evaluated by measuring the CSF albumin and comparing it with the serum albumin. Albumin is usually used as the reference protein for permeability because ordinarily it is not found to any great extent in the central nervous system.

A physician needs to prescribe a drug to a patient but the drug has a narrow therapeutic window. He is concerned about possible toxic effects. To assess the upper concentration of such a drug, which time for drawing the specimen do you think makes the most sense? The correct answer is highlighted below Approximately one hour after an oral dose 2-4 hours after an IV injection of a drug Before any drug is given Right before the next dose of the drug is given

The drug should be measured at a time corresponding to the peak concentration (not the trough). One to 2 hours after an oral dose is usually sufficient time for a drug to be absorbed and should correspond to peak concentration. A drug measurement that is taken 2 to 4 hours after an IV injection of the drug will not represent the peak value. A drug that is given via IV enters the circulation immediately, and the peak concentration of the drug would be measured 15 to 30 minutes after the IV injection. A measurement that is taken just before the next dose is given represents the trough value of the drug.

Which of the following Rh antigens is found the highest frequency in the Caucasian population: The correct answer is highlighted below C E c e

The e antigen is present in 98% of the Caucasian population.

An electrolyte panel (lytes, chem-4) consists of: The correct answer is highlighted below Potassium, Sodium, Chloride, Carbon dioxide Potassium, Sodium, Chloride, Glucose Potassium, Sodium, Chloride, Creatinine Potassium, Sodium, Chloride, BUN

The electrolyte panel consists of potassium, sodium, chloride, carbon dioxide. These analytes are also typically ordered within other panels as well, including the basic metabolic and complete metabolic panels.

Which of the following statements is true regarding cardiovascular disease and adipose tissue? The correct answers are highlighted below Inflammatory cytokines, synthesized and released by adipose tissue, contribute to the development of cardiovascular disease A state of abnormal lipids and lipid levels found in metabolic syndrome contribute to the development of cardiovascular disease Obesity in metabolic syndrome contributes to the development of cardiovascular disease by increased synthesis and secretion of adiponectin Increased synthesis and secretion of PAI-1 in metabolic syndrome contributes to cardiovascular disease by increasing blood pressure

The increase in inflammatory cytokines and the abnormal lipids and lipid levels often present in metabolic syndrome increase the risk of cardiovascular disease. Adiponectin is decreased and increases in angiotensinogen lead to hypertension.

A small portion of colonial growth of an unknown bacterial species was inoculated to the surface of a filter paper strip impregnated with cytochrome oxidase reagent (dimethyl-p-phenylenediamine dihydrochloride). The family of bacteria ruled out by the reaction seen in the photograph is the: The correct answer is highlighted below Pasteurellae Neisseriaceae Enterobacteriaceae Pseudomonadaceae

The key biochemical reactions by which the family Enterobacteriaceae can be identified include fermentation of carbohydrates, reduction of nitrates to nitrites and the absence of cytochrome oxidase activity. Some or all of the members of the other family of bacteria listed in this exercise produce cytochrome oxidase. A positive spot oxidase test, therefore, as shown in this photograph, is a helpful initial step in separating these families of bacteria from members of Enterobacteriaceae.

Which is the main limitation of standard PCR that is not a limitation of real-time PCR? The correct answer is highlighted below Requirement of a large initial sample Inability to quantitate DNA product due to endpoint analysis only Ability to detect PCR product during the plateau stage

The main limitation of standard PCR is the inability to quantitate the DNA product due to reliance on endpoint analysis. The final yield of a product is not always equal to the estimated exponential growth per cycle. Therefore, quantitation is not possible with endpoint analysis. Real-time PCR overcame this limitation.

Which type of lipoprotein transports the MAJORITY of cholesterol to cells for steroid hormone synthesis or cell membrane incorporation? The correct answer is highlighted below chylomicrons very low density lipoproteins low density lipoproteins high density lipoproteins

The majority of cholesterol is transported by LDL to the various cells in the body, and the rest is transported by HDL through reverse cholesterol transport for excretion purposes, ultimately through bile or bile salts. VLDL transports endogenous products, whereas chylomicrons transport exogenous (dietary) products."

What condition is indicated by the following blood gas results: Bicarbonate = 32 mmol/L (Normal = 22 - 26 mmol/L); pCO2 = 65 mm Hg (Normal = 35 - 45 mmHg); pH = 7.28 (normal = 7.35 - 7.45) The correct answer is highlighted below Healthy condition Uncompensated metabolic acidosis Compensated metabolic acidosis Uncompensated respiratory acidosis

The normal pH of blood is 7.40. In order for most metabolic processes to take place, the pH must remain within a narrow range close to this value. The range is usually defined in adults as 7.35-7.45. If blood pH falls below 7.35, the blood becomes too acidic (acidosis). If blood rises above 7.45, the blood is too alkaline (alkalosis). As blood pH decreases, the kidneys will retain bicarbonate (HCO3-) from the glomerular filtrate; therefore, bicarbonate is increased. However, in this case, the increased HCO3- could not compensate for the markedly elevated pCO2 (the respiratory component) and the condition that results is uncompensated respiratory acidosis.

An acid-fast bacillus recovered from a post-surgery wound of a young child had the following characteristics: Rapid growth (3-5 days) on blood and chocolate agar nitrate positive; niacin negative urease positive; catalase 25/68ºC positive; iron uptake positive Which of the following is the MOST likely identification? The correct answer is highlighted below M. tuberculosis M. scrofulaceum M. kansasii M. avium-intracellulare M. fortuitum

The organism is M. fortuitum since it demonstrates rapid growth, is nitrate positive, niacin negative, and urease positive, while demonstrating a positive iron uptake test. M. fortuitum is actually the only Mycobacterium species with a positive iron uptake reaction. M. tuberculosis is niacin positive, catalase negative- which rules it out as a possible choice. M. scrofulaceum is nitrate negative which also rules it out. M. kansasii is niacin negative and nitrate positive, but takes 10-20, on average, to grow. M. avium-intracellulare is catalase negative which aids in ruling out this organism as well. M. fortuitum is the only organism that matches the reaction patterns and description shown.

In order to prevent a loss of viability in platelet concentrates during storage the pH must be maintained above: The correct answer is highlighted below 7.5 6.2 5.0 4.5

The proper pH for a unit of platelets must be above 6.2. According to the FDA, accurate pH measurement is time dependent, and samples should be tested within 1 hour of sampling, or as suggested by the manufacturer of the pH measurement system. It is recommended that a pH meter or gas analyzer be routinely used rather than pH (nitrazine) paper. However, if the laboratory chooses to determine pH measurements with nitrazine paper, the selected paper should read in increments of one-tenth units, or it may provide inaccurate measurements. Maintaining proper pH requires at least 35 ml, but preferably 50-70 ml of plasma per platelet unit.

Consider the following set of results from a mixing study of a patient with a suspected coagulopathy. Initial aPTT Immed. aPTT mixing study Incubated aPTT mixing study 86 sec. (normal range 21-34 seconds) 87 sec. 88 sec. Is the aPTT in this case corrected or not corrected? Does this support the presence of a factor deficiency or coagulation inhibitor? The correct answer is highlighted below Corrected, factor deficiency Corrected, coagulation inhibitor Not corrected, factor deficiency Not corrected, coagulation inhibitor

The results above show no correction in the aPTT analysis. This supports the presence of a factor inhibitor since the result did not change with the addition of factors contained in the pooled normal plasma. If this were a factor deficiency problem, we would expect to see a corrected mixing study result.

The nuclear appendage at the tip of the arrow is a normal finding in females but not in males. The correct answer is highlighted below True False

The small drumstick-like nuclear extension (Barr body) marked by the blue arrow is a chromatin mass which may represent a chromosomal remnant. These nuclear appendages are found in normal XX females, but would not be present in normal XY males. If such an appendage is found in a phenotypic male, Klinefelter's syndrome (XXY male) may be identified clinically. The appendage has a "drumstick" morphology.

Extrinsic cell characteristics are reflected by the forward and side scatter on a flow cytometry cytogram. The correct answer is highlighted below True False

The statement is false. Intrinsic cell characteristics (size and granularity) are represented by forward and side scatter. Extrinsic cell characteristics are represented by the fluorescent signal produced as a result of tagged monoclonal antibodies binding to antigens on the cell surface.

Which of the following methods is not a quantitative method for the determination of albumin? The correct answer is highlighted below Serum protein electrophoresis Nephelometry Sulfosalicyclic acid precipitation Colorimetric spectrophotometry

The sulfosalicylic acid method is a semiquantitative method and not a quantitative method. It is also not specific for albumin.

The bacterial species represented by the positive test illustrated in the photograph (CAMP POS) of a 5% sheep blood agar plate cross streaked with a hemolytic strain of Staphylococcus aureus has been associated with each of the following conditions except: The correct answer is highlighted below Toxic shock syndrome Urinary tract infection in pregnant women Osteomyelitis in infant Carcinoma of the colon

The test shown in the photograph is a positive CAMP reaction. The arrow-shaped zone of accentuated beta hemolysis provides a presumptive identification of Streptococcus agalactiae (group B). Of the conditions listed in this exercise, only carcinoma of the colon has no association with group B streptococci (Streptococcus bovis is the streptococcus associated with that condition). Group B streptococci are not uncommonly associated with urinary tract infections during pregnancy (Wood and Dillon, Am J Obstet Gynecol 140:515). A case of toxic shock syndrome caused by group B streptococcus was reported by Schleifert, et al (Clin Infect Dis 17:26-31, 1994). Cases of osteomyelitis have been reported both in children (MS Edwards, et al: J Pediatr 93:578-583, 1978) and in adults (Gordon and Oster: South Med J 77:643-745, 1984).

Which of the following is/are NOT associated with immediate hypersensitivity? The correct answers are highlighted below Hay fever Serum sickness Arthus reaction Anaphylactic shock Tuberculin reaction

The tuberculin reaction is a type of delayed hypersensitivity reaction that appears 48-72 hours after antigen exposure, which is different from an immediate hypersensitivity response, which generally appears within 12 minutes of an antigen challenge. Arthus reactions and serum sickness are classified as a Type III hypersensitivty reactions involving the formation of immune complexes. The other choices above are all associated with immediate hypersensitivity reactions.

Which of the following urine chemical reagent strip tests is based on the Ehrlich-aldehyde reaction? The correct answer is highlighted below pH Protein Glucose Urobilinogen Specific gravity

The urobilinogen urine chemical reagent strip test is based on the Ehrlich-aldehyde reaction. In this test, a pink-red color forms in proportion to the amount of urobilinogen present.

Which of the following statements are TRUE for specific gravity measured by the reagent strip method? (Select ALL that apply) The correct answers are highlighted below The reagent strip method is based on the relationship between ionic concentration and specific gravity. The reagent strip method is based on the fact that light is refracted in proportion to the amount of total solids dissolved in the urine. The reagent strip method is not affected by the presence of x-ray contrast media in the urine specimen. An alkaline pH would not affect the specific gravity result using a reagent strip method.

There are two correct statements listed in the answer choices which accurately describe specific gravity measurements by the reagent strip method. These statements are: The reagent strip method is based on the relationship between ionic concentration and specific gravity. AND The reagent strip method is not affected by the presence of x-ray contrast media in the urine specimen.

patient who has a primarily vegetarian diet will most likely have an acid urine pH. The correct answer is highlighted below True False

This statement is false. A patient who has a primarily vegetarian diet will most likely have an alkaline urine pH. A low-carbohydrate diet as well as the ingestion of citrus fruits can also lead to a more alkaline urine sample.

In which disorder do neonates demonstrate the presence of Bart's hemoglobin that changes to beta chain tetramers in adults? The correct answer is highlighted below Alpha thalassemia major Alpha thalassemia minor Hemoglobin H disease Hydrops fetalis

When insufficient alpha chains are produced, the remaining globin chains often form tetramers. This condition is seen in alpha thalassemia intermedia or Hemoglobin H disease. In neonates the gamma chain is present in high amounts, forming tetramers known as Bart's hemoglobin. As gamma chain production decreases, beta chain production increases. Adults form beta chain tetramers (Hemoglobin H).

The colony in the upper image developed after 4 days of growth on Sabouraud's dextrose agar. Note the extension of the outer margin to the rim of the Petri dish. The lower image is a methylene-blue stained inoculum obtained from the surface of the colony. From these characteristics, select the fungus genus from the multiple choices. The correct answer is highlighted below Fusarium Trichoderma Gliocladium Acremonium

Trichoderma is the intended selection. The border to border extensions of the colony is similar to those of Gliocladium species, except the surface pigmentation is a light yellow green rather than deep green. Microscopically observed are small rather than large dense clusters of spherical conidia, here located at the tips of short conidiophores that are projected laterally from the hyphae. Acremonium colonies are gray to light shades of yellow with a smooth surface and do not extend to the margins of the Petri dish. The Conidia are arranged in loose clusters, each borne at the tip of a long, slender conidiophore ending in a blunt tip. A septum is observed at the base of each conidiophore. Fusarium colonies are cottony or wooly with a distinctive lavender, pink, deep red or magenta coloration. Microscopic Identification is usually made by observing macro-conidia that are long, sickle-shaped, and multi-celled, with transverse septa that separates the cells from one another. Exact focusing on the hilar cell reveals a hair-like ("foot cell") extension. Gliocladium colonies also have a border to border "lawn-like" extension along the Petri dish but with a green pigmentation. Microscopically observed in stained mounts are large clusters of densely packed spherical conidia borne from the tips of fingerlike conidiophores, simulating a penicillus structure.

Which of the following is NOT an expected or common laboratory finding in patients with hereditary hemochromatosis (HH)? The correct answer is highlighted below Elevated hemoglobin and hematocrit Elevated transferrin saturation Presence of HFE mutation Elevated serum ferritin

Typical laboratory findings in HH include elevated transferrin saturation, elevated serum ferritin, and presence of an HFE mutation. Elevated hemoglobin and hematocrit are not typically associated with HH.

When a patient has a bile duct obstruction, the bilirubin test portion of the reagent strip is: The correct answer is highlighted below Negative because unconjugated bilirubin is increased and cannot be excreted by the kidneys. Positive because unconjugated bilirubin is increased and is excreted by the kidneys. Negative because conjugated bilirubin is decreased and cannot be excreted by the kidneys. Positive because conjugated bilirubin is present and is excreted by the kidneys.

When a patient has a bile duct obstruction, the bilirubin test portion of the reagent strip is positive because conjugated bilirubin is present and is excreted by the kidneys. Unconjugated bilirubin, usually caused by red blood cell breakdown, is not able to be excreted from the kidneys, and will not cause a positive urine bilirubin result.

Which of the following casts is characteristically associated with acute pyelonephritis? The correct answer is highlighted below red cell white cell waxy fatty granular

White cell casts are closely associated with acute pyelonephritis since white blood cells are drawn to the infection and inflammation of the kidney (definition of pyelonephritis) and are encased into casts which slough off into the urine. Red cell casts are indicative of glomerular damage and can be seen in various conditions, but most often nephritic syndromes. Fatty casts are most commonly seen in nephrotic syndromes. Granular casts, composed of broken down cells or immunoglobulins, are most commonly associated with chronic renal disease.

Whole blood glucose values are ____________ plasma glucose values. The correct answer is highlighted below Greater than Lower than Equal to

Whole blood glucose values are lower than plasma glucose values. For this reason, point-of-care whole blood glucose meters are programmed to correct the value before presenting the result; therefore, the whole blood glucose meter result correlates to serum or plasma results.

What is the Wright-Giemsa stain used for MOST often in laboratory science? The correct answer is highlighted below peripheral & Cytospin smears bone marrows urinalysis gram stains

Wright-Giemsa stains are commonly used in the hematology laboratory for peripheral and cytospin blood smears to identify and quantitate blood cells.

Codocytes (target cells) are a typical finding in which of the following types of beta thalassemia? The correct answers are highlighted below Beta thalassemia minima Beta thalassemia minor Beta thalassemia intermedia Beta thalassemia major

all but minima

Which Lewis antigen(s) will be exhibited on the red cells of adults who have the Le, Se, and H genes? The correct answer is highlighted below Lea Leb both Lea and Leb neither Lea or Leb Se and H

nheritance of both Le and Se genes produces the Leb antigen on red blood cells. The Se gene codes for the enzyme, a-2-L-fucosyltransferase which adds L-fucose to the type 1 precursor H (type 1). The Le gene codes for another L-fucose which forms the Leb antigen. Some of the precursor chains are not affected by the Se gene and, therefore, form the Lea antigen. Hence, it is possible to see both Lea and Leb in the plasma and secretory fluids. However, only Leb adsorbs onto the red cells of adults (most likely due to competitive binding), causing them to phenotype Le(a-b+).

The most frequent genotype among Rho (D) -negative persons is: The correct answer is highlighted below r' r r' r" rr r'r'

rr is the most frequent genotype among Rh-negative individuals. The genotype symbolized a lack of the D (Rh) gene.