AMT MT Exam Set 2

All of the following are components of a basic single beam spectrophotometer, except: Beam splitter Cuvette Prism Light source

A beam splitter is employed in a dual-beam spectrophotometer. The spectrophotometer's basic components include light source - monochromator - cuvette - detector - readout. A light source is used to emit light through a sample for measurement in spectrophotometry. The monochromator selects a narrow band of light that can pass through, which will reach the sample cuvette. The detector detects how much light was reflected from or transmitted through the sample. Finally, the intensity of the transmitted light is measured with a photodiode or other light sensor/detector, and the transmittance value for this wavelength is then compared with the transmission through a reference sample, allowing for the readout of the result.

A technologist has 500 µL of serum and needs to make a 1/2 dilution for a glucose determination. How should he/she do it? 500 µL of serum plus 0.5 mL of saline 500 µL of serum plus 1 mL of saline 250 µL of serum plus 500 µL of saline 0.5 mL of serum plus 1.5 mL of saline

A dilution is written as Specimen volume/Total volume, so a 1/2 dilution would be 1 part serum to 2 parts total or an equal volume of diluent. 500 µL is equivalent to 0.5 mL. 500 µL of serum to 1 mL saline would yield a 1/3 dilution. 250 µL of serum to 500 µL of saline would yield a 1/3 dilution. 0.5 mL of serum to 1.5 mL of saline would yield a 1/4 dilution.

What is the identification of this cellular clump found in CSF? Note the presence of many similar-appearing nuclei without distinct lines of demarcation between cells. Cartilage cell Tumor cell clump Ependymal clump Lymphoblast clump

A key feature in identifying ependymal clumps is the presence of many similar-appearing nuclei without distinct lines of demarcation between cells. Basically, this cellular clump appears as one large cell, instead of many individual cells. On the other hand, choroid plexus clumps, mesothelial clumps, and macrophages do not display this "fused" morphology between cells. These types of cell clumps appear as individual cells gathered into a grouping. Cartilage cells usually occur singly. They are medium to large-sized cells with cytoplasm that stain wine red (with deep wine red nucleus). Tumor cells often occur in clumps. Cells in the clump are dissimilar, and some are multinucleated with variations in nuclear size. There are usually no clear spaces between the cells. Lymphoblasts can occur in CSF in acute lymphoblastic leukemia (ALL). They have the characteristics of lymphoblasts seen in blood with basophilic cytoplasm.

Which of the following phrases best describes a segmented neutrophil? Cytoplasm appears pink-purple due to small specific granules. Cytoplasm contains large red-orange granules. Cytoplasm is a pale blue color with a ground glass appearance. Cytoplasm is clear with no granules.

A segmented neutrophil has pink cytoplasm that contains fine specific granules scattered throughout the cell. Additionally, a segmented neutrophil typically displays a nucleus with 3-5 lobes connected by a filament.Cytoplasm contains large red-orange granules is incorrect. This would be a descriptor for an eosinophil. Monocytes are commonly characterized as having cytoplasm that is a pale blue color with a ground-glass appearance.

What is the maximum recommended amount of time a specimen without additive or anticoagulant should be allowed to clot before centrifugation? Two hours 30 minutes Three hours 10 minutes

A specimen without additive or anticoagulant should not be held for more than two hours prior to centrifugation because some of the analyte levels (such as glucose) may be falsely decreased due to cellular consumption or falsely increased (such as potassium) due to hemolysis. It should be allowed to clot for at least 30 minutes prior to centrifugation. Incomplete clotting of the specimen will leave small fibrin residue in the serum, which would interfere with testing or clog the testing instrument probe or tubing.

A 20-year-old female was admitted into the hospital complaining of 10 to 15 bloody mucous stools per day, fever, gastrointestinal disturbances, abdominal pain, and nausea. The preliminary O & P report went out as "Probable Entamoeba histolytica trophozoites and cysts, confirmation pending." What is this patient most likely suffering from? Traveler's diarrhea Extraintestinal amebiasis Intestinal amebiasis Giardiasis

According to the National Institutes of Health (NIH), the following symptoms are closely associated with intestinal amebiasis: Abdominal cramps Fever Diarrhea Vomiting Abdominal tenderness Fatigue Excessive gas Rectal pain while having a bowel movement Unintentional weight loss Bloody stoolsPassage of liquid stools with streaks of bloodPassage of 10 - 20 stools per day

When the body compensates for a respiratory or metabolic disorder, the MAIN goal is to achieve: Correct carbonic acid level since it is the most important system in the body. A normal pH Normal pO2 and pCO2 for normal respiration Correct bicarbonate level since it is the most important system in the body.

Because the body's cellular and metabolic activities are pH-dependent, the body compensates for alkalosis or acidosis of the blood PRIMARILY to regain a normal pH, between 7.35 - 7.45.

What biosafety level (BSL) is required by the Centers for Disease Control and Prevention (CDC) for working with Mycobacterium tuberculosis if there is a possibility that aerosols might be released? BSL-1 BSL-2 BSL-3 BSL-4

Biosafety Level-3 (BSL-3) safety level is recommended by the CDC if it is probable that aerosols might be released. There are four biosafety levels. Risk assessment is an important part of biosafety. The primary risks that determine containment levels are infectivity, the severity of disease, transmissibility, and the nature of the work conducted. In addition, the origin of the microorganism or agent in question and the route of exposure are important. Biosafety Level 3 (BSL-3) builds upon the requirements of BSL-2. Microorganisms that can be encountered in a designated BSL-3 laboratory can be either indigenous or exotic. They can cause serious or potentially lethal diseases through respiratory transmission. One example of a microbe that is typically worked within a BSL-3 laboratory is Mycobacterium tuberculosis. Biosafety Level 1 (BSL-1) is the least hazardous level. The risk of disease in healthy adults presents a minimal potential hazard to staff and the environment. An example of a microorganism typically studied in a BSL-1 laboratory is a nonpathogenic strain of E. coli. Biosafety Level 2 (BSL-2) builds upon BSL-1 requirements. A BSL-2 laboratory poses moderate hazards to laboratory staff and the environment. Encountered microorganisms are typically indigenous and associated with diseases of varying severity. An example of a microorganism is typically worked with at a BSL-2 laboratory is Staphylococcus aureus. Non-aerosol-producing manipulations (eg, preparing direct smears for acid-fast staining when done in conjunction with training and periodic checking of competency) can be performed using SL-2 practices and procedures, containment equipment, and facilities. For example, when working with the Zika virus in the laboratory, Zika virus preparations may be handled under BSL-2 precautions. Laboratories should perform a risk assessment to determine if certain procedures or specimens may require higher levels of biocontainment, e.g., use of a biosafety cabinet for potential aerosol-generating activities or suspicion that the specimen may contain a pathogen that requires BSL-3 precautions. Biosafety Level 4 (BSL-4) builds upon the containment requirements of BSL-3 and is the highest level of biological safety. There are only a small number of BSL-4 labs in the United States and globally. Microorganisms encountered in a BSL-4 lab are dangerous and exotic, posing a high risk of aerosol-transmitted infections. Infections caused by these microbes are frequently fatal and are without treatment or vaccines. Two examples of microbes encountered in a BSL-4 laboratory include Ebola and Marburg viruses.

The impedance principle shown in this illustration is best described by the following statement: Blood cells and platelets are counted by the number of the times they scatter light as they pass in front of a mirror. Blood cells and platelets are counted utilizing a type of diffraction gradient technique. Blood cells and platelets are counted by measuring the drop in transmitted light as they pass through a series of apertures. Blood cells or other particles are counted and sized based on changes in electrical resistance as they pass between two electrodes.

Blood cells or other particles are counted and sized based on changes in electrical resistance as they pass between two electrodes. The Coulter principle, developed by Walter Coulter in the late 1940 and early 1950s used "electrical impedance" to count and size particles. Cells or particles pass through two electrodes interrupting an electrical current. The number of interruptions represents the number of particles and the amount of resistance is proportional to the size of the particle. This principle is currently still being used by many manufacturers. Light scatter techniques can be used to count and categorize cells based on the degree to which light is deflected off particles. When combined with the use of stains, cells can be sorted and further differentiated by RBCs, Reticulocytes, WBC types and Platelets. Light scatter is not used in the Coulter principle for cell counting by electrical impedance. The diffraction gradient technique is not an aspect of the Coulter principle for cell counting by electrical impedance or resistance. Light transmission is not an aspect of the Coulter principle or cell counting by electrical impedance or resistance.

Which is in the correct order from the lowest concentration of H antigen to the highest concentration of H antigen? Bombay, A1B, A1, A2B, B, A2, O A1, O, B, A2, Bombay, A1B, A2B Bombay, O, A1B, A2, A1, B, A2B A1B, A2B, A2, O, B, A1, Bombay

Bombay, A1B, A1, A2B, B, A2, O The H antigen is an essential precursor to the ABO blood group antigens. Individuals with the rare Bombay phenotype (hh) do not express antigen H on their red blood cells; therefore, this type would contain the least amount of H antigen. Those which are type A1B would then have the second to least amount of H antigen since the precursor H antigens have been formed into A1 and B antigens instead. The remaining order of the H concentration from lowest to highest in the blood types given is: A1, A2B, B, A2, and O. O patients produce the most H antigen since they do not convert the H antigen into A or B antigens on their cell surface.

Which Brucella species has positive H2S production and may or may not need CO2 for growth? Brucella canis Brucella suis Brucella melitensis Brucella abortus

Brucella abortus may or may not need CO2 for growth and most strains are positive for H2S production. Brucella canis does not require CO2 for growth and is negative for H2S production. Brucella suis does not require CO2 for growth and can be positive or negative for H2S production. Brucella melitensis does not require CO2 for growth and is negative for H2S production.

Which one of the following antigen markers is BEST associated with stem cells? CD3 CD10 CD18 CD34

CD34, a cell surface marker, is present on undifferentiated, pluripotential hematopoietic stem cells. CD34 is a cell surface glycoprotein and functions as a cell-cell adhesion factor. CD3 is an antigen recognition marker and is present on precursor and mature T cells. CD10 is involved in regulation of B cells and is present on precursor B cells. CD18 is found on granulocytes and monocytes and regulates cell adhesion.

All of the following crystals are found in normal urine, EXCEPT? Triple phosphate Ammonium biurate Calcium oxalate Leucine

Calcium oxalates can be found in normal urine at varying pH levels. Ammonium biurate and triple phosphate can be found in normal alkaline urine. Leucine crystals are always abnormal and can be found in maple syrup urine disease.

A small child has albino characteristics, photophobia, frequent pyogenic infections, and her blood smear shows giant dark granules in her monocytes and granulocytes. What is the probable diagnosis? Pelger-Huet anomaly Alder-Reilly Toxic granulation Chediak-Hegashi syndrome

Chediak-Higashi syndrome is defined as the abnormal fusion of cytoplasmic lysozymes in granulocytes and occasionally monocytes. This condition is associated with albino characteristics, photophobia, and frequent infections (as the granules are dysfunctional and cannot fight infection appropriately). Pelger-Huet anomaly is associated with bi-lobed neutrophils. Alder-Reilly is associated with genetic mucopolysaccharidoses. Patients with mucopolysaccharidoses do not have the lysosomal enzymes necessary to break down mucopolysaccharides; hence dense azurophilic granules, resembling toxic granulation in neutrophils, are seen in all leukocytes. Finally, toxic granulation is associated with an increased amount of granulation inside leukocytes and is most commonly observed in infections and inflammatory conditions.

In blood, bicarbonate leaves the red blood cell and enters the plasma through an exchange mechanism with: Sodium Potassium Chloride Phosphorus

Chloride On the red cell membrane, there is a bicarbonate/chloride exchanger. The exchanger allows for bicarbonate to leave the red cells while chloride is allowed inside. This exchange maintains electroneutrality and is also known as the chloride shift.

A 72-year-old patient has a routine check-up and CBC. The CBC shows a high absolute neutrophil count of 28,000/µl, with slightly elevated bands, a few immature myeloid cells, and slight toxic granulation. Upon further examination of the patient, hepatomegaly and splenomegaly are noted. Because of the splenomegaly and the lack of obvious infection, a bone marrow exam is performed which shows hypercellularity of the granulocytes. Molecular testing yields a CSF3R mutation. The most likely diagnosis is: Pelger-Huet anomaly Chronic Myelogenous Leukemia (CML) Chronic Neutrophilic Leukemia (CNL) Primary Myelofibrosis (PMF)

Chronic Neutrophilic Leukemia (CNL) is a rare myeloproliferative disorder seen in older adults. They typically have high neutrophil counts, although there is not a profound shift to the left. Toxic granulation of the neutrophils can also sometimes be seen. Bone marrow exam is as noted above, but the differential diagnosis is the CSF3R mutation which distinguishes it from both CML and PMF and non-neoplastic disorders such as Pelger-Huet. Pelger-Huet anomaly is a benign condition characterized by bi-lobed neutrophils. CML shows hyperproliferation of the myeloid lines, but molecular analysis yields the bcr/abl translocation. PMF is usually characterized by marrow fibrosis and megakaryocyte proliferation. however, a leukoerythroblastosis can also sometimes be seen. There are a number of mutations associated with PMF, but not CSF3R.

The Clinitest® reaction is based on which of the following principles? Copper reduction Ortho-toluidine oxidation Diazotization of sugars Enzyme reaction

Clinitest® is a reagent tablet that is based on the classic Benedict's copper reduction reaction. It is performed on pediatric specimens in order to check for the presence of reducing substances. This additional step is an easy way of screening for inborn metabolic problems, in particular, galactosemia.

Which of the following parasites have adults forms that are found in the lungs and eggs commonly recovered in sputum samples? Fasciola spp. Clonorchis sinensis Opisthorchis spp. Paragonimus spp.

Correct answer: The only parasite of those listed that is commonly recovered in sputum specimens, is Paragonimus spp. The adult trematode is located in the lungs and the eggs may be found in sputum samples. Fasciola spp., Clonorchis sinensis, and Opisthorchis spp. are liver trematodes with the adults located in the bile ducts and the eggs recovered in feces.

All of the following may be typically recovered in positive blood cultures, EXCEPT? Candida albicans Candida glabrata Candida parapsilosis Cryptococcus neoformans

Cryptococcus neoformans, Candida albicans, Candida glabrata, & Candida parapsilosis all have been recovered from cerebral spinal fluid specimens. Although Candida albicans, Candida tropicalis, & Candida parapsilosis are commonly recovered from blood specimens, Cryptococcus neoformans is more commonly recovered from CSF.

Patients with Cushing's disease typically exhibit: Decreased plasma 17-hydroxysteroid concentration Decreased urinary 17-hydroxysteroid excretion Serum cortisol overproduction Decreased cortisol secretion rate

Cushing's disease is a hormone disorder caused by a pituitary tumor secreting too much adrenocorticotropic hormone (ACTH), which causes the adrenal glands to produce too much cortisol. Serum cortisol may be greater than 15 mg/dL. The serum reference range for cortisol is approximately 0.006 - 0.023 mg/dL, which is usually expressed as 6 - 23 micrograms per deciliter (µg/dL).

What is the most significant cause of decreased haptoglobin levels? Acute infection Intravascular hemolysis Liver disease Myoglobinuria

Decreased haptoglobin levels occur when intravascular hemolysis causes free hemoglobin to be released from damaged red cells. The free hemoglobin then binds to haptoglobin, leaving decreased haptoglobin levels. Hemolysis that occurs during or after blood collection will not affect serum haptoglobin levels. This helps to distinguish between in vivo and in vitro hemolysis.

Serological detection of the Vi antigen aids in the identification of: Escherichia coli Klebsiella species Salmonella Typhi Shigella species

Detection of somatic (O), flagellar (H), and capsular (K) antigens are used in the serologic grouping of Enterobacteriaceae. Many members of this family possess somatic and flagellar antigens, whereas non-motile species lack flagellar antigens. From the organism choices, Salmonella Typhi has the capsular Vi (virulence) antigen, which may mask the presence of the O antigen.

The amount of time it takes for a drug's concentration in the body to decrease by 50% is referred to as? Drug half-life Therapeutic window Pharmacokinetics Pharmacogenomics (Pharmacogenetics)

Drug half-life- The amount of time it takes for a drug's concentration in the body to decrease by 50%. Therapeutic window- The range between a drug's effective dose and its toxic dose. Pharmacokinetics- The study of drug disposition in the body - how and when drugs enter the circulation, how long they stay there, and how they are eliminated. Pharmacogenomics (Pharmacogenetics)- The study of how variations in the human genome affect a given individual's response to medications.

Which of the following blood group antigens are most susceptible to destruction by the action of enzymes? D Jka Lea Fya

Duffy, or Fya and Fyb antigens, are most sensitive to enzyme treatment since they will be destroyed during this process. Enzyme panels can be helpful when multiple antibodies, including Duffy, are present in a patient sample. With the Duffy antigens destroyed, the panel can be performed to identify the remaining antibodies present. Other antigens that are sensitive to enzyme treatment include those of the MNS system and Xga. D, Jka, and Lea are enhanced by enzymes (Rh, Kidd, Lewis, P1, I, and ABO).

Estrogen (ERs) and progesterone (PRs) receptors used as tumor markers are most commonly employed to provide prognostic information about: Breast cancer Uterine cancer Menopause Cervical cancer

ERs and PRs receptors are used as tumor markers for breast 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 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. The organism is also catalase-negative and non-spore-forming. The most likely identification is: Listeria monocytogenes Bacillus anthracis Corynebacterium diphtheriae Erysipelothrix rhusiopathiae

Erysipelothrix rhusiopathiae is associated with vertebrates and invertebrates including fish. It is considered an occupational hazard for fish handlers, farmers, food preparation workers, and others who have direct contact with infected animals or animal products. This organism is characteristically described as a catalase-negative, non-spore-forming bacillus that is capable of producing H2S *********** of the TSI agar. Listeria monocytogenes is a non-spore-forming Gram-positive bacillus but it is differentiated from Erysipelothrix as it is catalase-positive. It is also not able to produce H2S in the but of the TSI agar. Bacillus anthracis is a spore-forming Gram-positive bacillus that differentiates it from Erysipelothrix. It is also associated with soil or various herbivores but not fish. Corynebacterium diphtheriae is a non-spore-forming Gram-positive bacillus that is catalase positive which differentiates it from Erysipelothrix. It is an opportunistic organism that is capable of colonizing the human nasopharynx but it is not associated with handling fish.

What additional fraction would be seen if plasma rather than serum was subjected to electrophoresis: Alpha-1 antitrypsin Alpha-2 macroglobulin Fibrinogen Gamma globulins

Fibrinogen is only found in plasma. It is absent in serum because it is consumed during the clotting process. Fibrinogen present in plasma would form a band between the beta and gamma globulins. Electrophoresis separates the serum proteins into four bands, which from the anodal end are: albumin, alpha, beta, and gamma globulins.

Which of the following is a direct nucleic acid test? Fluorescence polarization immunization (FPI) Polymerase chain reaction (PCR) Fluorescence In Situ Hybridization (FISH) Nucleic acid sequence-based amplification (NASBA)

Fluorescent In Situ Hybridization (FISH) is a direct nucleic acid test that does not use amplification. All the remaining tests listed are amplification methods. FISH uses RNA Northern Blot or DNA Southern Blot techniques to detect targets of interest in cytology/histology specimens or other nucleic acid variations.

Diseases associated with a dysfunction of polymorphonuclear neutrophils (PMNs) include all of the following with the exception of: Chediak-Higashi syndrome (CH) Chronic granulomatous diseases (CGDs) Gaucher 's Disease Myeloperoxidase deficiency (MPO)

Gaucher's disease is a monocyte-macrophage disorder caused by a rare genetic defect. There is a high incidence of this disease in Ashkenazi Jews. There are two types of the disease: neuronopathic and nonneuronopathic, depending on symptoms. The disorder represents a deficiency of B-glucocerebrosidase, the enzyme that normally splits glucose from its parent sphingolipid, glucosylceramide. As a result of this enzyme deficiency, cerebroside accumulates in histiocytes (macrophages). Gaucher cells, typically a large cell with one to three eccentric nuclei and a characteristically wrinkled cytoplasm, are found in the bone marrow, spleen, and other organs of the mononuclear phagocyte system. Gaucher cells are rarely seen in the circulating blood. Chediak-Higashi syndrome is a congenital neutrophil abnormality. Because of an abnormal granulation of neutrophils, it results in a qualitative neutrophil disorder of neutrophils. The neutrophils with giant granules display impaired chemotaxis and delayed killing of ingested bacteria. Chronic granulomatous diseases(CGDs) are congenital neutrophil abnormalities. They are a genetically heterogeneous group of disorders of oxidative metabolism affecting the cascade of events required for H2O2 production by phagocytes during phagocytosis. Life-threatening infections can result. Patients with autosomal-recessive form may have a less severe clinical course than patients with X-linked forms of CGD Myeloperoxidase deficiency is a congenital neutrophil abnormality. Myeloperoxidase is an iron-containing heme protein responsible for the peroxidase activity characteristic of azurophilic granules in neutrophils. Human neutrophils contain many granules of various sizes that are morphologically, biochemically, and functionally distinct. The azurophilic granules normally contain myeloperoxidase. In myeloperoxidase deficiency, the azurophilic granules are present, but myeloperoxidase is decreased or absent. If phagocytes are deficient in myeloperoxidase, the patient's phagocytes manifest a mild-to-moderate defect in bacterial killing and a marked defect in fungal killing in vitro.

The technologist in the urinalysis department received a sample for a microscopic examination. The image to the right shows the microscopic urinalysis. Which of the following conditions below would most closely match this patient's microscopic urinalysis morphology? Diabetes mellitus Glomerulonephritis Yeast infection Pyuria

Glomerulonephritis is a type of kidney disease in which the glomerulus (filters waste and fluids from the blood) is damaged. Damage to the glomeruli causes blood and protein to be lost in the urine. Hence, the image shows the presence of red blood cells. Diabetes mellitus, yeast infections, and pyuria are not associated with red blood cells in the urine.

Which is the first marker (antigen or antibody) which will become positive after exposure to Hepatitis B? HBsAg Anti-HBs Anti-HBe IgG anti-HBc

HBsAg is detectable 2 to 12 weeks post-exposure during the acute stage and becomes undetectable in 12 to 20 weeks after the development of anti-HBsAg. HBeAg appears after the HBsAg and, in recovering patients, disappears before HBsAg. IgM anti-HBc is the first antibody to appear, and it persists for about 6 months.

In the image to the right, small, minute, colonies are growing around a colony of Staphylococcus aureus on sheep blood agar. Which of the following organisms is this a characteristic? Haemophilus influenzae Abiotrophia species Moraxella catarrhalis Haemophilus ducreyi

Haemophilus influenzae is the correct answer. Haemophilus influenzae requires both X (hemin) and V (NAD) factors to grow. The X factor is provided by the blood agar, but since sheep blood agar has NADase, the V factor is broken down; therefore, the Staphylococcus aureus provides the Haemophilus influenzae organism the V factor needed. Hence, the tiny growth around the Staphylococcus aureus colonies. Abiotrophia species is incorrect. Abiotrophia species will not grow on sheep blood agar unless vitamin B6 is provided. Vitamin B6 can be provided either by using blood agar supplemented with vitamin B6 or by placing a pyridoxal disk on sheep blood agar. In addition, this species does not need X or V factors in order to grow. Moraxella catarrhalis is incorrect because Moraxella catarrhalis does not need X or V factors to grow and does not have any fastidious growth requirements. Moraxella catarrhalis can grow on sheep blood agar. Haemophilus ducreyi is incorrect because Haemophilus ducreyi will grow on sheep blood agar as this species only needs X factor to grow.

A 17-year old African-American male had the following laboratory results: Sickle cell screen = positive Hemoglobin Electrophoresis:Hb S = 40%Hb A = 58%HbA2 = 2% Which of the following is the PROBABLE hemoglobin genotype? SS AS SC AC

Hemoglobin AS, or sickle trait, is associated with approximately 60% hemoglobin A and 40% hemoglobin S on hemoglobin electrophoresis, while Hemoglobin SS disease or sickle cell disease is associated with hemoglobin S levels >90%. In hemoglobin SC disease or with a hemoglobin C trait, such as in hemoglobin AC, you would expect to see hemoglobin C levels in the electrophoresis results.

Human chorionic gonadotropin (hCG) is used in the determination of: Liver function Fetal maturity Pregnancy Steroid levels

Human chorionic gonadotropin (hCG) is a hormone produced in pregnancy that is made by the developing embryo and later produced by the placenta. Its role is to maintain progesterone production that is critical for a healthy pregnancy.

Which of the following is responsible for the humoral immune response: Neutrophils Basophils B lymphocytes Monocytes

Humoral immunity involves antibody production. Most B lymphocytes participate in the humoral response through their transformation into plasma cells and secretion of antibodies. Other B cells become long-lived memory cells. Neutrophils are part of cellular immunity. Their major function is phagocytosis and destruction of foreign material and microorganisms. Basophil granules contain histamine, and they play a vital role in allergic reactions and the inflammatory response. Monocytes are phagocytic cells and recognize bacterial pathogens. While monocytes do present antigens to B-lymphocytes to initiate the adaptive immune response, it is the B lymphocyte that is responsible for the antibody production of the humoral immune response.

A patient has an increased RBC count with a decreased Hb and normal Hct. The MCV is microcytic, and the RDW is within normal limits. Many codocytes are present on the peripheral smear. Serum iron is 165 µg/dL (normal = 60 -150 µg/dL), and the TIBC is 230 µg/dL (normal = 250 - 400 µg/dL). Consider the findings on alkaline hemoglobin electrophoresis, which show an increased level of hemoglobin A2 of 5% (normal values are less than 3.5%). What is this patient's most likely diagnosis? Beta thalassemia silent carrier Beta thalassemia minor Beta thalassemia intermedia Beta thalassemia major

In normal adults, the majority of hemoglobin (95% to 97%) is Hemoglobin A, which is composed of two Alpha chains and two Beta chains. Beta thalassemias are a group of genetic disorders resulting in a defect in the synthesis of Beta chains. This defect can manifest as anemia of varying degrees, depending on the inheritance pattern. Beta thalassemia minor occurs when a person inherits a heterozygous Beta-thalassemia mutation. The laboratory findings typically include mild, microcytic, hypochromic anemia, increased target cells (codocytes), and increased levels of Hemoglobin A2. Beta thalassemia silent carrier is when a patient has a very mild Beta mutation and shows no clinical or laboratory evidence of anemia, and has a normal hemoglobin A2 level. Beta thalassemia intermedia is a less severe disorder than Beta thalassemia major and occurs in patients who are homozygous for a combination of less severe Beta globin mutations. In these patients, the degree of anemia varies; however, levels of Hemoglobin A2 remain in the normal range. Beta thalassemia major occurs when a person inherits a homozygous Beta mutation (two identical Beta mutations). These patients have severe, transfusion-dependent anemia. Hemoglobin electrophoresis shows an increase in Hemoglobin F and a lack of Hemoglobin A.

What are the PRIMARY reagents used in the activated partial thromboplastin time (aPTT)? Thromboplastin and sodium chloride Activated partial thromboplastin and potassium Activated partial thromboplastin and calcium Actin and sodium chloride

In the aPTT procedure, measured amounts of activated partial thromboplastin and calcium are used to activate the clotting process and measure the clotting time. Sodium chloride, potassium, and actin are not used for this reaction. Thromboplastin is one of the key reagents in prothrombin time (PT) testing.

A urine specimen was collected at 6:00 a.m. and remained at room temperature until it was received in the laboratory at 3:30 p.m. How may the pH of the specimen be affected by the extended time at room temperature if bacteria are present in the specimen? The pH may become more acidic. The pH may become more alkaline. The pH will become neutral. The pH would probably not be affected.

In this case, the pH may become more alkaline, perhaps above 8.0, if the bacteria in the sample are proliferating during the extended room-temperature wait time.

A physician obtains a peritoneal fluid sample by lavage on a patient who complained of fever and abdominal pain following an automobile accident. The fluid is analyzed in the laboratory. How should the sample shown in the image to the right be reported? Lymphocytes Eosinophils and parasites Mesothelial cells Neutrophils and bacteria

In this image, there are intracellular bacteria inside of the neutrophils, a sign of bacterial infection; therefore, both of these observations should be reported. In addition, extracellular bacteria are also noted in the field. This finding should be included as well. Lymphocytes have round nuclei and may be associated with a viral infection. Eosinophils have large orange granules in the cytoplasm. Mesothelial cells, cells that line the peritoneal cavity, are large and may be multinucleated.

Which of the following methods would be employed to collect sweat for chloride analysis: Electrophoresis Counter electrophoresis Iontophoresis Isoelectric focusing

Iontophoresis is the gold standard for the collection of sweat for sweat chloride analysis. Pilocarpine iontophoresis actually stimulates the production of sweat, which is absorbed within a gauze pad which was previously weighed dry. The sweat sample is weighed to determine how much sweat was collected. Finally, the sweat sample is analyzed for its concentration of chloride. This particular test is utilized very commonly for the screening of cystic fibrosis since these patients typically exhibit higher levels of sweat chloride. In children over the age of 6 months to adults, the reference ranges are: Equal to or less than 39 mmol/L = Cystic Fibrosis is not likely to be present (rules-out CF) 40 - 59 mmol/L = Intermediate Level (Cystic Fibrosis may be present, further testing required) Greater than or equal to 60 mmol/L = Cystic Fibrosis is most likely present

A patient suffering from typical leukemic symptoms presents in the emergency room. Physicians order a spinal tap after noticing possible central nervous system involvement. What are the cells seen in the spinal fluid cytospin preparation? Reactive mesothelial cells Lymphocytes and Blasts Monocytes Reactive Lymphocytes

Lymphocytes and Blasts In this cerebrospinal fluid cytospin, the predominant cell type appears as large cells with irregularly shaped nuclei, prominent nucleoli, and scant cytoplasm. These cells are L2 Lymphoblasts and would be reported as blasts. Examples are indicated by the red arrows. There are also a few normal lymphocytes in this field as well. Examples are indicated by the blue arrows.

The white blood cell that can vary MOST in size and shape on a Wright-stained smear is: Basophil Eosinophil Neutrophil Lymphocyte

Lymphocytes will vary in size and shape more than any white blood cell. A normal small lymphocyte is obvious on a Wright-stained smear. Its nucleus is generally round to oval with dense chromatin, and cytoplasm is scant and stains pale blue. However, large lymphocytes have more abundant cytoplasm and may approach the size of neutrophils. Reactive lymphocytes have an even greater range of morphologic differences; some may even have the characteristics of early cells, including the presence of nucleoli and deeply basophilic cytoplasm.

What are the two polypeptide chains that comprise the LD molecule? M and B L and D H and B M and H

M and H polypeptide chains combine to create 5 arrangements of the major isoenzymes of LD (HHHH, HHHM, HHMM, HMMM, MMMM). M and B are polypeptide chains that are part of the creatine kinase enzyme and make up the major isoenzymes including MM, MB and BB

The measurement of sodium and chloride in the sweat is the most useful test for the diagnosis of what condition/disease? Steatorrhea Direct determination of the exocrine secretory capacity of the pancreas. Cystic fibrosis Zollinger-Ellison syndrome

Measurement of the sodium and chloride concentration in sweat is the most useful test in the diagnosis of cystic fibrosis. Significantly elevated concentrations of both ions occur in more than 99% of affected patients.The definitive test for steatorrhea (failure to digest or absorb fats) is the quantitative fecal fat analysis.The secretin/CCK (cholecystokinin) test is the direct determination of the exocrine secretory capacity of the pancreas.Pancreatic cell tumors, which overproduce gastrin, are called gastrinomas; they cause Zollinger-Ellison syndrome and can be duodenal in origin.

What is the platelet precursor cell found in the bone marrow? Megakaryocyte Megaloblast Myeloblast Pronormoblast

Megakaryocytes are the precursors of platelets. A megaloblast is an abnormally large erythroblast. A myeloblast is a precursor cell in the neutrophilic cell lineage. A pronormoblast is another term for rubriblast and is a precursor cell in the red blood cell lineage.

Illustrated here are colonies growing on Middlebrook 7H10 agar before (lower) and after (upper) exposure to light. Colonies are intermediate between smooth and rough depending on the strain. Prior to light exposure, the colonies are gray-white. Upon exposure to ambient light, visible yellow pigment production is observed as characteristic of one of the "photochromogens", as illustrated in the top composite colony photograph. The acid-fast stain reveals slender acid-fast bacilli with cross banding. Characteristic of this isolate are positive reactions for several biochemical reactions - nitrate reduction, Tween 80 hydrolysis, catalase, and urease. With these observations, select the species name of this isolate. Mycobacterium scrofulaceum Mycobacterium avium-intracellulare Mycobacterium kansasii Mycobacterium fortuitum

Mycobacterium kansasii is the correct response. The conversion from gray-white to distinctly yellow-pigmented colonies upon exposure to ambient light is characteristic of one of the photochromogens. The observation of rod-shaped acid-fast bacilli with cross banding is characteristic of this presumptive identification, supported by the selective positive reactions produced by several of the biochemicals used in the identification of acid-fast bacilli -- nitrate reduction, Tween 80 hydrolysis, catalase, and urease. Mycobacterium scrofulaceum is a Scotochromogenic acid-fast bacillus, where yellow pigmentation of colonies would be observed both prior to and after exposure to ambient light. Acid-fast bacilli are observed in acid-fast stains, but are non-selective. The difference between this species and M. kansasii is that this species has negative biochemical reactions for nitrate reduction and Tween 80 hydrolysis. Mycobacterium avium-intracellulare is a nonphotochromogenic Mycobacteria. Colonies on 7H10 agar vary from smooth to wrinkled and no pigment is produced with or without light. Long, slender acid-fast bacilli with faint cross barring are observed in acid-fast stains. The biochemicals listed as being positive for M. kansasii are negative. Mycobacterium fortuitum is a rapid grower and colonies are never pigmented, even after exposure to light. Rapid growth in culture occurs within 3 - 5 days and is an additional distinguishing characteristic from M. kansasii. Biochemical reactions listed for M. kansasii are also positive for M. fortuitum and are not distinctive.

What is the term used to describe inadequate blood supply that decreases availability of oxygen to the myocardium? Acute myocardial infarction (AMI) Angina Congestive heart failure (CHF) Myocardial ischemia

Myocardial ischemia - an inadequate blood supply that decreases the availability of oxygen. CHF - a clinical syndrome caused by heart disease, represented by abnormal sodium and water retention and breathlessness, usually resulting in edema. AMI - cardiac tissue death (necrosis) due to lack of oxygen caused by obstruction of circulation. Angina - chest pain caused by an inadequate supply of oxygen to heart myocardium.

This foot infection, as illustrated in the upper photograph, was the result of a farmer walking barefoot in soil contaminated with filariform larvae. Based on the morphology of the 50 µm ovum (lower image), select the organism that is the probable cause of this infection. Trichuris trichiura Enterobius vermcularis Necator americanus Ascaris lumbricoides

Necator americanus is the correct response. Humans become infected by direct penetration of hookworm filariform larvae into hair follicles, pores, or skin (upper image) that have come in direct contact with contaminated soil such as the infected feet of barefoot workers, the hands of farmers and miners, or other dirt-contact activities. The 50 µm in diameter ovum as illustrated in the lower photomicrograph has a smooth, thin smooth shell and internal yolk sacks that leave a clear space. Trichuris trichiura is an incorrect response. Human infections with Trichuris result from ingestion of embryonated eggs via hands, food, or drinks that have been contaminated directly by infested soil, or indirectly by playthings, domestic animals, or dust. The ova have a distinctive barrel shape and convex hyaline plugs at each narrow end. Enterobius vermicularis is an incorrect response. Human infections result from finger to mouth transfer of eggs from the peri-anal region of an infected person directly to another person, or from handling infected fomites. Infections also result from ingestion of eggs transferred by contaminated dust, from surfaces such as toilet seats, or by ingestion of contaminated food or water. The ova are oval in outline, have a thin smooth shell, and one side flattened side simulating a deflated football. Ascaris lumbricoides is an incorrect response. Infections are common in children of school age from the hand-to-mouth transmission of infective eggs, or by contact with contaminated soil through sports or playground activities when skin may be directly infected. The ova differ by being oval to spherical with a thick roughened shell covered with an albuminous coat.

Which of the following is a sign of dyserythropoiesis that occurs in Myelodysplastic Syndromes? Oval macrocytes Schistocytes Basophilic stippling Sickle cells

Oval macrocytes along with dimorphic RBC population are features of the dyserythropoiesis that can occur in Myelodysplastic Syndromes. Schistocytes are fragmented RBCs that result from a hemolytic process. Basophilic stippling is found in Sideroblastic Anemia and Lead Poisoning. Sickle cells are only found when Hemoglobin S is present such as in Sickle Cell Anemia.

How does the laboratory immunologic assessment of Waldenstrom's Primary Macroglobulinemia differ from other monoclonal gammopathies? Frequently an increase in IgG, possibly an M spike on serum protein electrophoresis. Overproduction of IgM antibodies. Only kappa or lambda monoclonal light chains or Bence-Jones protein seen on serum protein electrophoresis. Characterized by the presence of monoclonal proteins composed of the heavy chain portion of the immunoglobulin molecule.

Overproduction of IgM antibodies. Waldenstrom's macroglobulinemia (WM) is a B-cell disorder characterized by the infiltration of lymphoplasmacytic cells into bone marrow and the presence of an IgM (19S)monoclonal gammopathy. The basic abnormality in this macroglobulinemia is the uncontrolled proliferation of B lymphocytes and plasma cells. As a result, there is a heavy accumulation of monoclonal IgM in the circulating plasma and plasmacytoid lymphocytes in the bone marrow. In many cases, WM is associated with mixed cryoglobulinemia, which reflects the binding of IgG and IgA antiidiotypic antibodies to the mutant IgM. In a small number of patients, dysplastic tumor cells secrete 7S IgM monomers, ...chains, or other monoclonal immunoglobulins or fragments. But the major IgM production indicates that the immunoglobulin (gene) lesion sometimes degenerates and codes for more than one M component. Serum electrophoresis usually demonstrates the overproduction of IgM antibodies. Diagnosis of WM is made by the demonstration of a homogeneous M component composed of monoclonal IgM. Blood samples are described as having hyperviscosity. In addition, cryoglobulins can be detected in the patient's serum. The characteristics of an increase in IgG with possibly an M spike on serum protein electrophoresis is diagnostic of Multiple Myeloma (MM). MM is the most common form of dysproteinemia. MM is the prototypical monoclonal gammopathy. IgG myeloma is the most common form of MM. In light Chain Disease (LCD), only kappa or lambda monoclonal light chains or Bence-Jones proteins are seen on serum protein electrophoresis. LCD represents about 10% to 15% of monoclonal gammopathies. The presence of monoclonal proteins composed of the heavy chain portion of the immunoglobulin molecule is characteristic of Heavy Chain Disease. This monoclonal gammopathy can display alpha, gamma or Mu forms of the disease.

When iontophoresis is used to collect sweat for chloride analysis, pilocarpine is used to: Clean the skin area Complex with chloride Stimulate nervous system Induce the sweat secretion

Pilocarpine actually stimulates sweat glands, which helps to induce sweat secretion during a sweat chloride test via iontophoresis. Sweat chloride determinations are used in the diagnosis of cystic fibrosis. This measurement is also called the "sweat test". Sweat chloride concentrations =60 mmol/L are indicative of cystic fibrosis.

Which Plasmodium species tends to infect any red blood cell, regardless of the age of the cell? Plasmodium ovale Plasmodium falciparum Plasmodium vivax Plasmodium malariae

Plasmodium falciparum and Plasmodium knowlesi will infect any red cell, at any age. Because of this, heavy infections may result. Plasmodium ovale and Plasmodium vivax tend to infect young red blood cells. Plasmodium malariae tends to infect old red blood cells.

It is important to specify if a blood specimen is a capillary specimen rather than a venous specimen. How will the following laboratory results be affected if a capillary specimen is tested? -Potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. -Potassium, calcium, and total protein are higher in capillary specimens, where glucose is typically lower than in venous blood. -Potassium and total protein are lower in capillary specimens, where glucose and calcium are typically higher than in venous blood. -Potassium and total protein are higher in capillary specimens, where glucose and calcium are typically lower than in venous blood.

Potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. Capillary blood obtained for laboratory testing is significantly different from the usual venous blood tested. It is a mixture of venous, arterial, and capillary blood as well as interstitial and cellular fluids. Because of this mixture, capillary blood more closely resembles arterial rather than venous blood and the reference values will differ. Analytes such as potassium, calcium, and total protein are lower in capillary specimens, where glucose is typically higher than in venous blood. Therefore, it is extremely important a notation is made on the requisition slip to inform the person performing the testing that the blood is capillary and not venous.

Which of the following definitions describes ribonucleic acid (RNA)? A double-stranded polymer that houses genetic information A single-stranded polymer that incorporates uracil instead of thymine All the genes in an organism The genome is organized into discrete elements

RNA is a single-stranded polymer that incorporates uracil instead of thymine. DNA (deoxyribonucleic acid) is in a double helix formation and it has thymine paired with adenine. The genome is considered all the genes in an organism. The genome is organized into discrete elements that are known as chromosomes.

Codocytes (target cells) are an expected finding in all of the following phenotypes of beta thalassemia, EXCEPT? Beta thalassemia minima Beta thalassemia minor Beta thalassemia intermedia Beta thalassemia major

Red blood cell morphology is typically normal in beta thalassemia minima. Target cells are only seen on occasion and therefore would not be an expected finding. Target cells are slightly increased in the minor phenotype, moderately increased in the intermedia phenotype, and markedly increased in the major phenotype.

Which of the following barriers are recommended in microbiology laboratories where manipulation of biosafety level 3 agents (e.g., Mycobacterium tuberculosis) is performed? Manual closing single-door access Positive airflow that moves air out of the laboratory Filtered and recirculated air can enter other lab areas Self-closing double-door access

Self-closing double-door access At biosafety level 3, laboratory manipulations should be performed in a Class I or Class ll BSC. Secondary barriers should include self-closing double-door access and NEGATIVE airflow into the laboratory. Exhausted air must not be recirculated. Air may be high-efficiency particulate air (HEPA) filtered, reconditioned and recirculated within that laboratory area, but never into other laboratory areas.

Which of the following serological tests would be used for the diagnosis of Q-fever? Weil-Felix test Quellung test EIA or indirect immunoflourescence Cold agglutinin test

Serology testing utilizing indirect immunofluorescences or EIA is the most commonly used methodology. IFA is considered the reference method due to its high specificity and sensitivity in both acute and chronic infections. It is also reliable, cost-effective, and easy to perform. The Weil-Felix test detects cross-reacting rickettsia antibodies by using Proteus vulgaris. The Quellung test utilizes antibodies to bind to the bacterial capsule, which can be used to identify serotypes of Streptococcus pneumoniae. Cold agglutinins are autoantibodies that cross-react with red blood cells (RBCs). They cause RBCs to clump together when the person is exposed to cold temperatures and increases the chances of those RBCs getting destroyed.

Which statement best describes small dense LDL particles that can occur in atherogenic dyslipidemia? -Small dense LDL molecules are less atherogenic than larger, less dense, or buoyant LDL particles because they are metabolized faster -Small dense LDL molecules transport more cholesterol and thus are more atherogenic -Small dense LDL molecules are more atherogenic because they can more easily move into the endothelium and vessel wall -Small dense LDL molecules are just as atherogenic as the larger ones

Small dense LDL molecules are more atherogenic because they can more easily move into the endothelium and vessel wall. In excess triglycerides, the triglycerides reduce the amount of cholesterol in LDL particles producing small dense LDL molecules. Because of size and density, these molecules more easily enter damaged endothelium and vessel walls and are more easily incorporated as plaque is formed.

Which of the following is most likely to interact with arterial walls, leading to deposition of cholesterol, and initiating or worsening atherosclerosis? Large buoyant LDL Small dense LDL LDL phenotype 'A' VLDL

Small, dense LDL is most likely to interact with arterial walls, leading to deposition of cholesterol, and initiating or worsening atherosclerosis. Small, dense LDL is associated with more than a three-fold increase in the risk of coronary heart disease. Large, buoyant LDL is less atherogenic than small, dense LDL. The LDL phenotype A is normal. It is the so-called 'B' pattern that is associated with an increased risk of atherosclerosis. VLDL transports endogenous (hepatic-derived) lipids to the peripheral tissues during fasting periods for energy utilization and storage and is not associated with atherosclerotic plaques.

Which of the following sets of results is indicative of stage 3 iron deficiency (iron deficiency anemia)? -Decreased ferritin, normal soluble transferrin receptor (sTfR), slightly increased total iron-binding capacity (TIBC) -Decreased ferritin, increased sTfR, increased TIBC -Decreased ferritin, increased sTfR, decreased TIBC -Increased ferritin, normal sTfR, increased TIBC

Stage 3 iron deficiency, or iron deficiency anemia, presents with a decreased ferritin, increased soluble transferrin receptor (sTfR), decreased serum iron, increased TIBC, and decreased saturation percent. Stage 3 iron deficiency also presents with a decreased hemoglobin in males and females, as well as microcytic, hypochromic red blood cells on the peripheral blood smear. In fact, these are the main laboratory findings routinely seen that separate stage 2 and stage 3 iron deficiency. A decreased ferritin result is one of the first findings in iron deficiency, seen in stage 1. Ferritin is decreased as more stored iron is released for heme synthesis due to decreased iron availability. It is important to remember ferritin is an acute phase reactant and will be increased in inflammatory conditions. Transferrin receptors are found on the outside of cells, which is how iron bound to transferrin is transported into cells. During iron deficiency, there is an overexpression of transferrin receptors, which are eventually cleaved and released into the bloodstream, leading to an increased sTfR. Total iron-binding capacity (TIBC) is an indirect measure of transferrin, representing all available binding sites on transferrin. When low iron levels are detected by hepatocytes, transferrin levels increase, leading to an increased TIBC.

The most frequent cause of bacterial meningitis in adults and in children is: Streptococcus pneumoniae Neisseria meningitidis Haemophilus influenzae Escherichia coli

Streptococcus pneumoniae is the most common cause of meningitis in adults and in children. Neisseria meningitidis causes meningitis in adults and in children, but not as frequently as S. pneumoniae. Haemophilus influenzae and E. coli usually cause meningitis in infants (1 month to 23 months of age). Other organisms can also cause bacterial meningitis, particularly Streptococcus agalactiae, in neonates (less than one-month-old) and infants (1 to 23 months of age), and Listeria monocytogenes in infants and in adults older than 65 years of age.

Large, gray to white, beta-hemolytic colonies were isolated on sheep blood agar from peritoneal fluid. The following biochemicals were performed: Gram Stain: Gram-positive cocci in chains and pairs Catalase: Negative PYR: Positive Bacitracin Sensitive Identify the organism from the choices provided. Alpha hemolytic streptococcus species Streptococcus pneumoniae Streptococcus pyogenes Streptococcus agalactiae

Streptococcus pyogenes is the correct answer because this organism is beta-hemolytic on sheep blood agar, has a gram stain morphology of gram-positive cocci in chains, is catalase-negative, PYR positive, and bacitracin sensitive. This organism is a common etiologic agent of primary peritonitis in children and adults. Primary peritonitis occurs when an infection spreads from the blood and lymph nodes in patients who do not appear to have evidence of an infection. Alpha hemolytic streptococcus species is the incorrect answer because this species is alpha-hemolytic, which rules out this organism as a choice. In addition, this organism is not a common etiologic agent of peritonitis. Streptococcus pneumoniae is an incorrect answer because this organism is alpha-hemolytic and not beta-hemolytic, which rules out this organism. However, Streptococcus pneumoniae is a common cause of primary peritonitis in children and adults. Streptococcus agalactiae is incorrect because this organism is bacitracin resistant and has small, beta-hemolytic colonies on sheep blood agar. This organism typically causes infections in unborn fetuses, which can lead to miscarriages, and to newborns.

All of the following carbohydrates are considered reducing sugars EXCEPT: Lactose Sucrose Glucose Ribose

Sucrose is not a reducing sugar since the anomeric carbon of both monosaccharides (glucose and fructose) are part of the glycosidic bond, preventing the anomeric carbon of fructose (and therefore its ketone group) from being free and reducing other compounds. Lactose, Glucose and Ribose are all reducing sugars since their anomeric carbons and aldehyde groups are all free to reduce other compounds.

Which of the following immunosuppressive drugs below has been associated with thrombus formation in patients with toxic levels? Tacrolimus Cyclosporine Sirolimus Mycophenolic acid

Tacrolimus is a potent immunosuppressive drug that has been shown to cause thrombi formation at levels above the therapeutic range. Cyclosporine, sirolimus, and mycophenolic acid are all immunosuppressive drugs and can cause thrombocytopenia but are not known to cause thrombi formation.

Which of the following tests has been recommended by the FDA to replace the HIV-1 p24 antigen test in the screening of donated blood for infectious diseases? HIV-1 NAT Anti-HIV-1 Anti-HIV-2 HCV NAT

The FDA recommends that HIV-1 nucleic acid testing (NAT) be done in place of HIV-1 p24. Anti-HIV-1 and anti-HIV-2 are still required screening tests. HCV NAT is recommended as part of the battery of tests but is done to detect Hepatitis C Virus.

A lipid panel consists of which of the following tests? -Potassium, Sodium, Chloride, CO2 -AST, ALT, Alkaline Phosphatase, Total Protein, Albumin, Total Bilirubin, Direct Bilirubin -Cholesterol, Lipoprotein, HDL, Triglycerides -Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Calcium, Albumin, Phosphorus

The Lipid Panel consists of Cholesterol, Lipoprotein, HDL, Triglycerides. 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. The Hepatic Function Panel A consists of AST, ALT, Alkaline Phosphatase, Total Protein, Albumin, Total Bilirubin, Direct Bilirubin. The Renal Function Panel consists of Glucose, BUN, Creatinine, Sodium, Potassium, Chloride, CO2, Calcium, Albumin, Phosphorus.

Which of the following factors does not affect the result of the aPTT assay? Factor X Factor IX Factor VIII Factor VII

The aPTT is prolonged secondary to deficiency of factors of the intrinsic pathway, specifically: prekallikrein (Pre-K), high-molecular-weight kininogen (HMWK), Factors XII, XI, IX, VIII, X, V, II, and I. Factor VII is in the extrinsic pathway. Deficiencies of Factor VII would prolong the PT.

In the hemoglobin methodology using potassium ferricyanide the following measurable reaction occurs: Carboxyhemoglobin is formed Iron remains in the ferrous state Ferrous iron is oxidized to ferric iron to form methemoglobin Acid hematin is formed

The correct answer here is ferrous iron is oxidized to ferric iron to form methemoglobin. In an alkaline medium, potassium ferricyanide oxidizes hemoglobin to methemoglobin. Further in the reaction, potassium cyanide produces cyanmethemoglobin, which has a maximum absorbance at 540 nm. Color intensity is proportional to total hemoglobin concentration, which is how the hemoglobin levels are measured. Carboxyhemoglobin is formed when carbon monoxide reacts with hemoglobin, not with potassium ferricyanide. Iron will not remain in the ferrous state but instead will react with the potassium ferricyanide oxidizing to the ferric state. Acid hematin is used in the determination of hemoglobin within a patient but is not formed in this reaction.

How long after collection can a patient's sample be used for compatibility testing? 72 hours 24 hours 96 hours 7 days

The correct answer is 72 hours. Samples used for antibody screening and serological crossmatches must be less than or equal to 72 hours (3 days) old. 7 days is the required retention time of donor and patient samples following transfusion.

Which of the following describes the quality standards that all laboratories must meet to ensure testing accuracy, reliability, and timeliness no matter where a patient sample is tested? Safe Medical Devices Act Health Insurance Portability and Accountability Act Clinical Laboratory Improvement Amendments Occupational Safety and Health Administration

The correct answer is Clinical Laboratory Improvement Amendments (CLIA) In 1988, U.S. Congress passed The Clinical Laboratory Improvement Amendments in order to establish quality standards for all laboratory testing to ensure accuracy, reliability and timeliness of laboratory results regardless of where the patient's specimen was tested. The Safe Medical Devices Act deals with death or serious injury occurring due to a medical device and the reporting of such incidents. The Health Insurance Portability and Accountability Act was developed to make it easier to detect and prosecute fraud and abuse. Occupational Safety and Health Administration is responsible for regulations pertaining to general workplace safety of U.S. workers.

A 32-year-old male was seen in the emergency room with severe gastrointestinal discomfort and occasional vomiting. The patient noted that he first began feeling ill after spending a day at the park swimming and playing volleyball barefooted. Initially he noticed a lesion on his foot, and later developed vague respiratory symptoms. This patient is most likely suffering from a parasitic infection with: Echinococcus granulosus Necator americanus Entamoeba histolytica Trichuris trichuria

The correct answer is Necator americanus. Necator americanus is the only option listed that gains entry to the host by penetrating intact human skin. Ancylostoma duodenale and Strongyloides stercoralis are also able to enter the host by penetrating intact skin and migrate through the body causing respiratory symptoms and eventually intestinal discomfort. Echinococcus granulosus enters the host by ingestion of eggs. The eggs are carried to the liver, lung and/or brain and develop hydatid cysts. Entamoeba histolytica enters the host by ingestion of a mature cyst. Once inside the host, the cyst will multiply by binary fission and the trophozoite emerges. Trichuris trichuria enters the host by ingestion of an embryonated egg from which larvae hatch once they enter the intestine.

"Universal precautions" is an approach to infection control that is designed to reduce the risk of transmission of microorganisms in hospitals and other health care settings. Which of these statements BEST describes the intent of standard precautions? -Once a patient has been diagnosed with a disease that could be transmitted through blood, it is necessary to use personal protective equipment to handle specimens from that patient. -All inpatients and specimens from these patients should be handled using appropriate engineering controls and personal protective equipment. This is not necessary when in contact with outpatients or specimens from these patients as they are obviously healthy. -All blood, tissue, body fluids, secretions (except sweat), and excretions should be considered potentially infectious, and health care workers should use appropriate personal protective equipment and safe work practices when in direct contact with patients or any specimen types. -Personal protective equipment and engineering controls should not be used when handling patient specimens. Using these items could contaminate the patient sample.

The correct answer is all blood, tissue, body fluids, secretions (except sweat), and excretions should be considered potentially infectious, and health care workers should use appropriate personal protective equipment and safe work practices when in direct contact with patients or any specimen types. Universal precautions should be used whenever contact with these substances is anticipated and not just in instances where the presence of the disease has been confirmed. Universal precautions should be observed even in the outpatient setting when patients appear healthy and do not have symptoms of infection. Remember, patients who are infected with organisms such as hepatitis C and HIV can remain symptomless long after initial infection, but the organism can still be transmitted through blood or other body fluids.

Osteomyelitis can only be diagnosed by collection and subsequent culture of a sample collected from which source? Bone CSF Blood Urine

The correct answer is bone. Osteomyelitis is an infection of the bone that is generally associated with local pain and tenderness with a restriction in movement. This condition may be suspected in patients with other septic conditions that exhibit the above symptoms, as it most commonly follows other infections after bacteremic spread. CSF, blood, and urine would not assist in the definitive diagnosis of osteomyelitis.

All of the following descriptions about Pasteurella species are true, EXCEPT: Forms large amounts of indole .Grows well on MacConkey agar. Many infections are caused by domestic animals. P. multocida is the species most frequently isolated from humans.

The correct answer is growing well on MacConkey agar. Pasteurella spp. generally do not grow on MacConkey agar, but generally grow well on sheep blood agar or chocolate agar at 37°C. They are catalase, oxidase, and indole positive. Most infections are caused by dog and cat bites or scratches and are caused by P. multocida.

Each of the following tests is helpful in the species identification of Staphylococcus aureus EXCEPT: Thermostable endonuclease Deoxyribonuclease Modified dimethyl sulfoxide (DMSO) test Tube coagulase test

The correct answer is modified dimethyl sulfoxide (DMSO) test. DMSO is used to react with cell wall constituents to make the bacterial cell-permeable to the diffusion of the oxidase reagent. This test is used to differentiate members of the genus Micrococcus, which are modified oxidase-positive, from the members of the genus Staphylococcus which are negative. Therefore, this test does not distinguish S. aureus from most other staphylococci, all of which are oxidase negative. Staphylococcus aureus, however, does uniquely produce a thermostable endonuclease and deoxyribonuclease. Both of these tests use DNase test medium with toluidine blue O to detect the hydrolysis of DNA by the test organism. The tube coagulase test also is used to separate S. aureus from other coagulase-negative staphylococci.

How is valproic acid (Depakote) administered? IM injection Sublingual Oral preparation IV

The correct answer is oral preparation as the gastrointestinal tract completely and rapidly absorbs valproic acid, so other delivery methods are not as useful for therapy.

Bacterial contamination is MOST likely in which of the following blood products? Packed red blood cells Frozen red blood cells Platelets Fresh frozen plasma

The correct answer is platelets. Bacterial contamination of platelets is most likely because they are stored at room temperature. The estimated rate of bacterial contamination in platelets is around 10%. Bacterial contamination is possible in packed red blood cells stored in the refrigerator, but the estimated rate of bacterial contamination is only around 0.2% Frozen red blood cells are not likely to have bacterial contamination. Fresh frozen plasma is not likely to have bacterial contamination.

What is the correct order of erythrocyte maturaton in the bone marrow? (beginning from the most immature) -Polychromatophilic normoblast, basophilic normoblast, polychromatophilic erythrocyte, orthochromic normoblast, pronormoblast -Orthochromic normoblast, basophilic normoblast, polychromatophilic normoblast, polychromatophilic erythrocyte, pronormoblast -Pronormoblast, basophilic normoblast, polychromatophilic normoblast, orthochromic normoblast, polychromatophilic erythrocyte -Pronormoblast, basophilic normoblast, polychromatophilic erythrocyte, orthochromic normoblast, polychromatophilic normoblast

The correct order of maturation is: pronormoblast, basophilic normoblast, polychromatophilic normoblast, orthochromic normoblast, polychromatophilic erythrocyte. Once the pluripotential stem cell differentiates into the myeloid stem cell, it can differentiate into an erythroblast. The subsequent stages listed are all identifiable on a bone marrow smear. Alternative nomenclature is: rubriblast, prorubricyte, rubricyte, metarubricyte, reticulocyte. The final stage is the mature erythrocyte. The other choices contain the correct names of the stages but they are incorrect order.

A 62-year-old man drank an unknown liquid in a suicide attempt, and his urine contained crystals similar in shape to those shown in this image. This man MOST likely ingested: Methanol Isopropanol Ethylene glycol Ethanol

The crystals that are seen in the urine are monohydrate calcium oxalate crystals. Oxalic acid, a byproduct of ethylene glycol (antifreeze) metabolism, combines with calcium in the body to form monohydrate calcium oxalate crystals, as shown in the accompanying image. Accidental poisoning with ethylene glycol occurs most of the times in young children and pets. This is because it is a sweet tasting compound and if left uncovered in an easily reachable place it can be very tempting to consume.

The infective stage for the majority of all intestinal amebae is the: Trophozoite Cyst Larva Egg

The cyst is the infective stage for most amebae. The cyst is nonfeeding and environmentally resistant. It is the infective stage. Infections are generally caused by ingestion of the cyst stage. The other stage of most amebae is a motile feeding stage called a trophozoite. It reproduces by binary fission. It is not infective. Larva and eggs are not stages associated with the intestinal amebae.

Which of the following macroscopic findings is MOST consistent with the microscopic finding of casts? Specific gravity of 1.005 Positive protein Alkaline pH Clear urine

The following factors promote the formation of casts in the kidney: Larger than normal amounts of plasma proteins entering the tubules Decreased pH Decreased urinary flow rate Increased urine concentration

Which of the following Corynebacterium species is lipophilic? Corynebacterium jeikeium Corynebacterium amycolatum Corynebacterium ulcerans Corynebacterium striatum

The genus Corynebacterium is a large, diverse group of bacteria with approximately 50 clinically significant species. Corynebacteria can be divided into nonlipophilic and lipophilic species. Lipophilic corynebacteria are often considered to be fastidious and grow slowly on culture media, taking up to 48 hours of incubation before growth is detected. Growth is enhanced if lipids are added to the culture medium. The only lipophilic organism in the choices above is Corynebacterium jeikeium. The other three species are nonlipophilic.

What is the half-life for aminoglycoside antibiotics in the blood? 1-2 hours 2-3 hours 3-4 hours 4-5 hours

The half-life of aminoglycosides is roughly 2-3 hours, are bound to plasma proteins, and are eliminated by the kidneys.

What is the most common Rh haplotype among whites? Dce DCe DcE dce

The haplotype DCe is found in 42% of whites,17% of blacks, and 70% of Asians. The haplotype Dce is found in 4% of whites, 44% of blacks, and 3% of Asians. The haplotype DcE is found in 14% of whites, 11% of blacks, and 21% of Asians. The haplotype dce is found in 37% of whites, 26% of blacks, and 3% of Asians.

This suspicious form was found in a stool specimen and measures 54 µm by 32 µm. What is the identification? Taenia egg Echinococcus egg Hymenolepis egg Pseudoparasite

The image shows an egg of Hymenolepis. Hymenolepis eggs have a characteristic embryo in the center with three pairs of hooks. Surrounding the embryo is an embryophore and a capsule. H. diminuta averages 55 by 85 µm and H. nana typically measures 45 by 38 µm in size. Taenia eggs are similar to Hymenolepis as they also have a central embryo with three pairs of hooklets. However, the embryophore of Taenia has radial striations and is typically a yellow/brown color. Additionally, Taenia eggs are smaller, averaging 33 by 23 µm in size. The diagnostic stage of Echinococcus infections is not the egg form, but rather the larval stage. The larval stage is characterized by a hydatid cyst, which is found in infected tissue. Pseudoparasite means a false or fake parasite, such as matter in the sample that resembles a parasite but is not one. Based on the very round edges and visible internal structures, this is an egg, specifically a Hymenolepis egg.

Increases in the MB fraction of CK is associated with: Liver disease Bone disease Kidney failure Myocardial infarction

The isoenzyme CK-MB is fairly cardiac-specific. It is elevated within 6 to 8 hours of myocardial infarction and remains elevated for about 2 to 3 days post-infarction. CK exists in three isoenzymes, besides CK-MB, we have CK-MM associated with a muscle injury and CK-BB associated with brain injury.

Which of the following statements best describes a normal mature erythrocyte? A biconcave disc, 6-8 µm in diameter, that stains pinkish-orange (salmon) in color A biconcave disc, 7 µm in diameter, with a salmon-colored cytoplasm and condensed nucleus A biconcave disc, 6-8 µm in diameter, containing ribosomes and mitochondria A biconcave disc, 7 µm in diameter, responsible for transporting myoglobin

The mature erythrocyte is a biconcave disc that measures about 6-8 µM in diameter. When stained with a Romanowsky stain, erythrocytes appear pink to orange due to hemoglobin, an intracellular acidic protein. The mature erythrocyte does not contain a nucleus. The nucleus is last seen in the orthochromic normoblast. After the nucleus is extruded from the orthochromic normoblast, the cell is known as a reticulocyte. Mature erythrocytes do not contain ribosomes and mitochondria. These are last seen in the reticulocyte and are responsible for producing about 20% of the cell's hemoglobin (about 80% is made during the normoblast stages). Erythrocytes contain hemoglobin, the carrier protein for oxygen in blood and facilitator of carbon dioxide transport. Myoglobin is a carrier protein for oxygen in the muscle.

After the physician orders a follow up for abnormal coagulation screening tests, the laboratorian completes a mixing study with the following results: Initial aPTT result: 98 seconds Initial 1:1 Mix with Normal Pooled Plasma: 28 seconds Incubated 1:1 Mix with Normal Pooled Plasma: 30 seconds Which of the choices below would most likely explain the results for this patient? Immediate-acting coagulation inhibitor Time/temperature-dependent coagulation inhibitor Factor VIII deficiency Factor VII deficiency

The only correct answer of the choices listed above is the presence of a factor VIII deficiency. Factor deficiencies are usually corrected during the mixing study when normal pooled plasma is added to the sample. The normal pooled plasma contains high enough coagulation factors to correct the deficient level in the patient sample, causing a normalized aPTT result. In this case, it could not be a factor VII deficiency, as this coagulation factor is measured in the PT assay alone. There are also no coagulation inhibitors present (either immediate-acting or time/temperature-dependent) as the aPTT mix would not have displayed this correction pattern.

The following is the primary virulence factor produced by Streptococcus pneumoniae that prevents phagocytosis: Streptolysin O Capsule M protein Exfoliative toxin

The polysaccharide capsule produced by Streptococcus pneumoniae and other organisms protects the organism from phagocytosis. This capsule causes the organism to be mucoid and more virulent. Less virulent strains do not produce a capsule. Streptolysin O is a virulence factor for Streptococcus pyogenes. It is also responsible for the beta hemolysis produced by the organism on blood agar along with Streptolysin S. The M Protein is produced by Streptococcus pyogenes and has antiphagocytic properties. It mediates post-streptococcal diseases such as Rheumatic fever and glomerulonephritis. The exfoliative toxin is produced by Staphylococcus aureus. This toxin causes the sloughing of the epidermis, especially in newborns, in an infection disease call Scalded Skin Syndrome (SSS).

Which of the listed fingers should be used for dermal puncture to obtain capillary blood specimens? #1 Thumb or #2 Index finger #2 Index finger or #4 Ring finger #5 Little finger or #2 Index finger #4 Ring finger or #3 Middle finger

The primary sites used to obtain a capillary specimen are the middle (#3) and ring (#4) fingers. The thumb is not used because it is often more calloused and has a pulse. The index finger is often very calloused and may cause more discomfort for the patient. Finally, the fifth or little finger often does not have enough fleshy pad and may lead to possible puncture of the bone.

Which of the following is the principle for the biuret method for total protein analysis? Digestion of protein; measurement of nitrogen content Formation of violet-colored chelate between Cu2+ ions and peptide bonds Globulins are precipitated in high salt concentrations Proteins separated based on electric charge

The principle of the biuret method is the formation of violet-colored chelate between Cu2+ions and peptide bonds.Digestion of protein; measurement of nitrogen content is the principle for the Kjeldahl method for total protein measurement.Globulins are precipitated in high salt concentrations is the principle for salt precipitation and it is considered an albumin method, not a total protein method.Proteins separated based on electric charge describes the principle for electrophoresis.

A secondary immune response is generally associated with which of the following antibodies? IgG IgA IgM IgD

The secondary or anamnestic response has a short lag phase, typically with higher titers than the primary immune response, and IgG predominates. IgA is the immunoglobulin class associated with mucosal immunity. IgM is the immunoglobulin class that predominates in a primary immune response. IgD is involved in the maturation process of B cells, which become immunoglobulin-secreting plasma cells.

All of the following have an impact on electrophoresis techniques in the clinical laboratory EXCEPT? Amount of light present in electrophoresis box Support medium pH Voltage

The type of support media, type of stains used, and voltage settings all impact electrophoresis techniques; however, the amount of light present in an electrophoresis box does not. Support medium can affect the migration of analytes based on the medium's pore size and endosmosis. pH can change the charge of the analyte and thus affect mobility. It can also denature the analyte (protein). Voltage is proportional to the velocity of the analyte migration. Ionic strength, ions present, wattage, current, temperature, and time are other variables that can affect electrophoretic results.

A physician discusses weight with an overweight 60-year-old female at her yearly physical appointment. The female exercises regularly and eats healthy most of the time. The physician suggests she decrease carbohydrate intake and decrease portion size at meals. Review patient vital signs and laboratory assay results to decide if a diagnosis of metabolic syndrome is appropriate using the NCEP: ATP III Diagnostic Criteria shown on the right. Height: 5' 7'Weight: 192 lbsBMI: 30.1Waist Circumference: 37 inchesBlood Pressure: 108/70 Fasting Blood Glucose: 92 mg/dLTotal Cholesterol: 172 mg/dLLDL-C: 112 mg/dLHDL-C: 46 mg/dLTriglycerides: 70 mg/dLhs-CRP: <1.0 mg/L Which of these statements regarding this patient is true? This patient meets the criteria for diagnosis of metabolic syndrome. This patient does not meet the criteria for diagnosis of metabolic syndrome. There is not enough information provided in order to assess such a diagnosis. The patient does not meet the age requirements for assessing the diagnosis of metabolic syndrome.

This patient does not meet the criteria for diagnosis of metabolic syndrome. According to the NCEP: ATP III diagnostic criteria, this patient does not have metabolic syndrome. She has only two parameters outside the criteria limits: waist circumference and HDL-C. She does need to lose weight though because she does seem to have increased upper body fat according to the waist circumference measurement. This may eventually cause an increased triglyceride, increased blood glucose, and/or hypertension and metabolic syndrome diagnosis along with an increased risk for cardiovascular disease.

All of the following would be considered a part of the body's cellular immune system EXCEPT? Macrophages Mast cells Neutrophils Thrombocytes

Thrombocytes, or platelets, are involved with hemostasis, not immunity. Body defense systems include cellular and molecular components. The cellular component includes phagocytic cells, inflammatory mediators, and natural killer cells. The phagocytic cells include neutrophils, monocytes, and macrophages. Cells that release inflammatory mediators include basophils, mast cells, and eosinophils. The molecular component includes complement, acute phase proteins, and cytokines.

Thromboelastography is a point of care test which measures which of the following? The elasticity of the patient's vasculature The entire coagulation status of the patient The ability of platelets to change shape Thromboembolisms in the patient's vessels

Thromboelastography is a point of care test that can assess the entire coagulation status of the patient and gives a functional and holistic perspective of their ability to clot. The elasticity of the patient's vessels is not determined by this test. The ability of platelets to change shape in response to certain stimuli can be reflected in functional platelet tests such as platelet aggregation studies, not thromboelastography. The presence of thromboembolisms in a patient can be detected by assays such as d-dimer.

Which protein is also known as prealbumin because it migrates before albumin in the customary electrophoresis of serum or plasma proteins? Transferrin Transthyretin Retinol-binding protein Fibronectin

Transthyretin is sometimes called thyroxine-binding prealbumin or prealbumin because it migrates ahead of albumin in the customary electrophoresis of serum or plasma proteins. Transthyretin is considered the major transport protein for thyroxine. Transferrin is synthesized in the liver and bands are transports ferric iron. Retinol binding protein has been used in monitoring short-term changes in nutritional status and is considered the major transport protein of vitamin A. Fibronectin is considered the major protein regulating phagocytosis and it is not routinely used as a nutritional marker.

Which one of the following statements about urea is false? It accounts for 75% of nonprotein nitrogen excreted It is elevated in a variety of glomerular, tubular, interstitial, and vascular renal diseases It is decreased in dehydration The serum reference range for normal individuals is 6 to 20 mg/dL when expressed as blood urea nitrogen

Urea is actually increased, not decreased, during bouts of dehydration. Urea accounts for 75% of nonprotein nitrogen excreted by an individual, it is elevated in a variety of glomerular, tubular, interstitial, and vascular renal diseases, and the serum reference range for normal individuals is 6 to 20 mg/dL when expressed as blood urea nitrogen.

Which of the following may cause a false-positive protein reading on a urinalysis dipstick? -Urine pH is between 5.0 and 6.0. -The specimen has been refrigerated. -The urine specimen is highly pigmented. -A urine specimen with low specific gravity.

Urine specimens that are highly pigmented may result in a false-positive protein result. Freshly voided urine should be slightly acidic (pH between 5.0 and 6.0). Acidic urine will not interfere with the protein test. However, a highly buffered alkaline urine may cause a false-positive protein reading by overriding the acid buffer that is part of the protein reagent pad. A refrigerated specimen will not cause a false-positive protein result. It is, however, best practice to allow the urine to warm up to room temperature before testing. A false-positive protein result may occur in samples with high specific gravity, not a low specific gravity.

A quality control program is to be set up for the following tests: Phenylalanine deaminase (PAD)Indole productionVoges-Proskauer (V-P) Which pair of stock culture organisms would be most suitable to verify the performance of these three tests? Proteus vulgaris, Escherichia coli Klebsiella pneumoniae, P. vulgaris E. coli, Enterobacter aerogenes E. aerogenes, K. pneumoniae

When performing quality control, there should always be one organism that is positive for the requested testing and one organism that would be negative. This verifies that both positive and negative results of the testing would be accurate. When looking at the question, the first biochemical that stands out is PAD. PAD is ONLY positive for 3 genera: Proteus, Providencia, or Morganella. Thus, the answer needs to include one of these organisms for the positive control. Narrowing down the choices, that leaves Proteus vulgaris. The best choice then would be Proteus vulgaris (PAD+, indole+, and VP-) and Klebsiella pneumoniae (PAD-, indole-, and VP+), so there is a positive and negative result for each test. Proteus vulgaris and E.coli is not correct because Proteus vulgaris is PAD+, indole+, and VP-. E. coli is PAD-, indole+, and VP-. The indole and VP results are the same for both organisms and do not provide a positive and negative reaction for each. E. coli and Enterobacter aerogenes is not correct because E. coli is PAD-, indole+, and VP-. E. aerogenes is PAD-, indole-, and VP+. The PAD result for both is the same and does not provide a positive and negative reaction for each. E. aerogenes and K. pneumoniae are not correct because K. pneumoniae is PAD-, indole- and VP+. E. aerogenes is PAD-, indole-, and VP+. All results are the same for both organisms and do not provide a positive and negative reaction for each.