MLT EXAM
PSA is a tumor marker associated with tumors of what origin?
Prostate
Two CSF specimens were sent to the Lab with the following results: Tube #1 = 11,200 rbc/µL Tube #2 = 300 rbc/µL The results on these CSF specimens are indicative of: an infection a recent subarachnoid hemorrhage a traumatic tap an old intracranial bleeding episode faulty lab equipment
Traumatic taps are described as spinal fluid taps where blood vessels are pierced with the needle during aspiration, causing a contamination of the spinal fluid sample with blood or bone marrow. Traumatic taps are easily differentiated from true hemmorhages as in traumatic taps, each subsequent container of spinal flui drawn will have a smaller amount of red and white cells present. In a true hemorrhage, the red and white cell counts will remain steady in each subsequent tube of spinal fluid drawn.
Delayed hemolytic transfusion reactions (DHTR) usually occur within which time period? 5 hours after transfusion 24 hours after transfusion 3-10 days after transfusion one year after transfusion
3-10 days after transfusion Delayed hemolytic transfusion reactions (DHTR) are usually caused by a secondary (anamnestic) response. It takes about 3-10 days from the time of transfusion for enough antibody to be produced to cause clinical symptoms.
In order to correctly prepare a 4M solution of NaOH, how many grams need to be added to 200mL of solution? (GMW=40)
32g A general formula employed to determine the weight (in grams) of a substance to use to make a certain volume with a desired normality (or molarity) is as follows: Weight = Normality (or Molarity) x (volume needed ÷ 1000 mL/L) x Gram Equivalent weight/L Then, Weight = 4 (200mL ÷ 1000 mL/L) x 40g/L Weight = 32 grams NaOH (dissolved in 200 mL total volume will make a 4N solution)
How long may blood be stored using CPDA-1 preservative prior to transfusion?
35 days
A 4.0 mg/dl creatinine standard is needed. To prepare 100 ml of the working standard, how much stock standard of 1 mg/ml creatinine is needed?
4mL First the units of the stock standard and working standard must be converted into the same units. Then the following equation may be utilized to determine the answer: volume wanted x desired concentration/stock concentration = vol of stock standard needed
What is the CORRECT blood-to-anticoagulant ratio for coagulations tests? 4:1 5:1 9:1 10:1
9:1
Twelve weeks after onset of the disease, patients with uncomplicated acute hepatitis B usually will demonstrate which of the following in their serum? HBsAg Anti-HTLV Anti-HBe Anti-HIV
Anti-HBe 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.
Which EBV markers would be MOST likely positive for an individual who had infectious mononucleosis 9 years ago? All would still be positive Anti-VCA (IgM) and heterophile Anti-VCA (IgG) and anti-EBNA None of the markers would be positive after 9 years
Anti-VCA (IgG) and anti-EBNA Viral capsid antigen VCA (IgM), VCA (IgG) and D early antigen (EA-D) are used to detect a current or recent infection. VCA (IgG) and Epstein Barr nuclear antigen (EBNA)are used to detect a previous infection. The EBV heterophile antibody titers are highest during the first four weeks of disease, but taper off after the infection has cleared; so it would not be positive in a patient infected 9 years ago.
Patients with antibody to the following antigen are immune to Hepatitis B: Core antigen Surface antigen e antigen Delta antigen
Patients who have antibodies directed against the hepatitis B surface antigen, or anti-HBs, have an immunity to hepatitis B. This is the principle behind hepatitis B vaccinations as proteins associated with the hepatitis B surface antigen are administered to an individual, who then produces an immune response against the surface antigen. The antibodies produced through this process allows for the immunization against the hepatitis B virus.
What is the site used most frequently in the adult patient when performing a bone marrow biopsy?
Posterior iliac crest
Elevation in conjugated bilirubin is most likely to be found in which of the following conditions: Transfusion reactions Erythroblastosis fetalis Cirrhosis of the liver Biliary obstruction
Posthepatic jaundice is the result of bile duct obstruction, not impaired hepatic function. It will result in elevation of direct (conjugated) bilirubin.
Estriol levels in conjunction with hCG and AFP can be obtained during pregnancy to: Assess the risk of Down's syndrome Assess fetomaternal function Assess for multiple gestations Assess for maternal diabetes mellitus
Assess the risk of Down's syndrome 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 genotypes cause beta thalassemia minor? B/B B+/B B0/B B0/B0
B+/B denotes beta thalassemia minor exhibiting partial deletion of one gene locus and B0/B denotes beta thalassemia minor exhibiting total deletion of one gene locus. B/B denotes a normal beta chain genetic component. B0/B0 represents beta thalassemia major, exhibiting total deletion of both gene loci.
A patient has a WBC count of 4,000/mm3, a platelet estimation with 3 bizarre platelets/oil immersion field, hemoglobin, hematocrit, red cell count and indice values are within normal limits. Blue-staining inclusions are seen in the cytoplasm of many neutrophils. These inclusions fit the description of: Auer rods Barr bodies Dohle bodies May-Hegglin bodies
Bizarre platelets are a hallmark feature of May-Hegglin Anomaly. Auer rods are found in myeloblasts, barr bodies are not abnormal and are insignificant, and Dohle bodies are usually found in infectious or inflammatory processes. Since the white cell count is normal, we would not suspect Dohle bodies in this case, even though they can appear very similar to May-Hegglin bodies on a peripheral smear.
Type B blood is found in higher frequency in: Blacks Whites Asians Black and Asians
Black and Asians About 44% of whites are group A and 9% are group B. In Asians, Hispanics, and blacks, the percentage of group A is about 28, and the percentage of group B individuals varies from 16 to 26%.
Which of the following tests detect LTBI: BAMT culture PCR Two-step TST
Both the BAMT (Blood Assay for Mycobacterium tuberculosis) and the two step TST (Tuberculin skin test) detect Latent TB (Tuberculosis) Infection (LTBI).
Which of the following is a selective media recommended for the isolation of Clostridium difficile? Cefoxitin-cycloserine-fructose agar (CCFA) Buffered-charcoal yeast extract(BCYE) agar Kanamycin Vancomycin laked blood (LKV) agar Thiosulphate citrate bile salts sucrose (TCBS) agar.
CCFA
Which of the following CD markers is NOT present on a normal mature T cell? CD20 CD7 CD3 CD5
CD20 is not present on mature T cells. CD20 is expressed by B cells. Normal mature T cells should express CD2, CD3, CD5 and CD7.
A patient is admitted to the hospital with acute chest pain, but which of the following enzymes will be elevated FIRST if the patient had an MI? LD CK AST ALT
CK CK, especially the isoenzyme CK-MB, rise typically within 4-6 hours after a myocardial infarction and stay elevated for days, with a peak at the 24-hour mark post-MI. The FASTEST cardiac enzyme to rise after a mycardial infarction is actually troponin, which can rise within 2 hours of a MI. LD, AST, and ALT can also be elevated after a myocardial infarction, but levels are slower to rise.
Which of the procedures listed below will increase the platelet concentration in the preparation of Platelets? Centrifuge the blood at a low speed, remove the plasma and spin the plasma again at a low speed. Centrifuge the bood at a low speed, remove the plasma and spin the plasma again at a high speed. Centrifuge the blood at a high speed, remove the plasma and spin the plasma again at a high speed. Increase the duration of rotation
Centrifuge the bood at a low speed, remove the plasma and spin the plasma again at a high speed. Preparation of Platelets is a two step process. The whole blood unit should be centrifuged at a low speed on the first spin. The platelets will then remain in the plasma portion of the bag (platelet-rich plasma). The platelet-rich plasma is then centrifuged again at a higher speed, forcing the platelets to the bottom of the container.
Most common methods for measuring bilirubin are based on the reaction of bilirubin with what?
Diazo reagent Diazotized sulfanilic acid (diazo reagent) reacts with bilirubin to produce colored azodipyrroles, which are measured spectrophotometrically.
A monoclonal B-cell population (Kappa or Lambda predominant) with expression of CD19, CD20, CD23, and co-expression of CD5 is consistent with which of the following? A normal B cell Chronic lymphocytic leukemia Mantle cell lymphoma A mature T cell
Chronic lymphocytic leukemia If Kappa or Lambda is predominant and CD5 is co-expressed with CD19 (CD19/CD5 dual positive lymphocyte population), and CD23 is expressed, chronic lymphocytic leukemia is a probable diagnosis. CD19 is normally found on normal B cell populations and CD5 is normally found on mature T cell populations. However, CD5 is present on B cells in B-chronic lymphocytic leukemia or Mantle Cell Lymphoma, both abnormal B cell malignant processes. CD23 expression is not consistent with Mantel cells as shown on the decision tree on the right.
CEA is a tumor marker associated with tumors of what origin?
Colon
An automated method for measuring chloride which generates silver ions in the reaction is called: 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.
Hypochromia can best be described as: Immature red blood cells Abnormal erythropoiesis Increase in nucleated RBCs Decrease in Hgb concentration in RBCs
Decrease in Hgb concentration in RBCs Hypochromia is characterized on the peripheral blood film by an increase in central pallor of red cells. In normal red cells, the area of central pallor is limited to the middle third of the red cell; it is enlarged in hypochromia.
Electrophoretic separation fundamentally relies on: Size differences of molecules Net charge differences of molecules Concentration differences of molecules Shape variations of molecules
Electrophoresis uses an electric field to separate molecules based on differences in net electrical charge. The rate of electrophoretic migration is also dependent on the ionic radius of the molecule, the viscosity of the solution through which it is migrating, the electrical field strength, temperature, and the type of supporting medium used.
A positive RPR test and a negative FTA-ABS test is most likely the result of: Primary syphilis Secondary syphilis Latent syphilis False positive reaction
False positive reaction The FTA-ABS is used to confirm that a positive non-treponemal test like RPR is not the result of a biological false positive, which occur in about 1 to 10 percent of the population.
The National Heart, Lung, and Blood Institute initiated the National Cholesterol Education Program (NCEP) in 1985. The goal was to reduce the number of Americans with elevated cholesterol and thus reduce illnesses and deaths in the United States due to coronary heart disease. Three adult treatment panels have been published since then with clinical practice guidelines for managing cholesterol levels in adults. The most recent panel, Adult Treatment Panel III (ATP III), was published in 2001 and updated in 2004. The NCEP: ATP III also includes criteria for the diagnosis of metabolic syndrome. Select the set of laboratory assays that are utilized in the NCEP: ATP III criteria for metabolic syndrome diagnosis. LDL-C, triglycerides, HDL-C, and fasting blood glucose Fasting blood glucose, triglycerides, insulin, and VLDL Fasting blood glucose, triglycerides, HDL-C Fasting blood glucose, triglycerides, HDL-C, and VLDL
Fasting blood glucose, triglycerides, HDL-C along with waist circumference and blood pressure are the measurements used in the NCEP: ATP III criteria.
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 present in plasma would form a band between the beta and gamma globulins.
What amount of absorbent material must be included between the primary receptacle and secondary packaging for either a category A or category B liquid specimen? At least enough to surround the primary receptacle Enough to completely absorb the specimen if the container leaked or broke Enough to fill the space between the primary receptacle and the secondary container There is no requirement for absorbent material
For liquids, absorbent material must be placed between the primary receptacle and the secondary packaging, and it must be in sufficient quantity to absorb the entire contents of the primary receptacle to prevent compromising the integrity of the outer packaging if breakage or leakage occurs.
Which of the following thyroid function assays is affected least by pregnancy: Total T3 Total T4 Free T4
Free T4 is affected the least by changes in plasma proteins during pregnancy.
What component is indicated for patients who receive directed donations from immediate family members to prevent transfusion-associated graft versus host disease (TA-GVHD)? Irradiated Red Blood Cells Washed Red Blood Cells IgA-deficient products HLA matched products
Gamma-irradiation of blood components containing viable lymphocytes is very effective in preventing TA-GVHD. Irradiation is recommended for all Whole Blood, Red Blood Cell, Platelets, and Granulocyte transfusions to patients at risk. Patients at risk include neonates less than 4 months, patients with an acquired or congenital immunodeficiency, or patients receiving a directed donation from a family member. . Irradiation prevents proliferation of donor lymphocytes with a required dose of 25 Gy to the mid plane of the blood container and a minimun15 Gy elsewhere.
The morphologic characteristic(s) associated with the Chediak-Higashi syndrome is (are): Pale blue cytoplasmic inclusions Giant lysosomal granules Neutrophils with many small granules and vacuoles Nuclear hypo-segmentation
Giant lysosomal granules Giant lysosomal granules are associated with Chediak Higashi syndrome. Pale blue cytoplasmic inclusions are dohle bodies or dohle-like bodies as found in May Hegglin anomaly. Neutrophils with many small granules and vacuoles, also called toxic granulation or toxic vacuolation, are associated with infections. Finally, nuclear hypo-segmentation is associated with Pelger Huet anomaly.
Which of the following hormones stimulates gluconeogenesis, the formation of glucose from noncarbohydrate sources such as amino acids, glycerol, and fatty acids? Insulin Epinephrine Cortisol
Gluconeogenesis is the formation of glucose from noncarbohydrates when carbohydrate intake is absent, a fasting state. The hormone cortisol along with glucagon stimulates this metabolic pathway.
A key laboratory characteristic by which Mycobacterium bovis can be separated from Mycobacterium tuberculosis is: Niacin accumulation when grown on egg based medium Ability to take up iron salts from the culture medium Growth inhibition by thiopine-2-carboxylic acid hydrazide (T2H) Semiquantitative catalase
Growth inhibition by thiopine-2-carboxylic acid hydrazide (T2H) Mycobacterium bovis is selectively inhibited by T2H, a key characteristic by which it can be separated from M. tuberculosis. As part of the M. tuberculosis complex, approximately 30% of M. bovis strains may slowly accumulate niacin; therefore, this is not a differential characteristic. Neither species uptake iron from culture media, a test that distinguishes Mycobacterium fortuitum from all other Mycobacterium species. The semiquantitative catalase reaction is negative for both organisms; therefore, this is not a distinguishing characteristic.
Cryoglobulin testing can be used to: Screen for rheumatoid arthritis Screen for systemic lupus erythematosus (SLE) Help diagnose Raynaud's syndrome Diagnose syphilis
Help diagnose Raynaud's syndrome Cryoglobulin is an abnormal serum protein with a unique ability to precipitate when exposed to cold temperatures. Cryoglobulin is present in Raynaud's syndrome.
In which disorder do neonates demonstrate the presence of Bart's hemoglobin that changes to beta chain tetramers in adults? Alpha thalassemia major Alpha thalassemia minor Hemoglobin H disease Hydrops fetalis
Hemoglobin H disease 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).
Monoclonal antibodies are usually produced by: Cultured T cells Human plasma cells Hybridomas Cytotoxic T cells
Hybridomas Monoclonal antibodies are monospecific antibodies that are the same because they are made by one type of immune cell which are all clones of a unique parent cell, also called a hybrid cell line, which usually arise from a hybridoma. The fusion of a specific antibody-producing lymphocyte with a myeloma cell will multiply to become a source of pure monoclonal antibody.
The primary mechanism responsible for glomerular filtration is: Osmotic gradient Concentration of blood components Rate of blood flow through the kidneys Hydrostatic differential in glomerular tufts
Hydrostatic differential in glomerular tufts The hydrostatic pressure in the capillaries of the glomerular tuft drives the filtrate across their semipermeable membrane. The normal glomerular filtrate is similar in composition to the plasma, with the exception that molecules with a molecular weight of greater than about 15,000 are not filtered.
Which of the following disorders is characterized by increased production of chloride in sweat? Multiple myeloma Hypoparathyoidism Cystic fibrosis Wilson's disease Down Syndrome
In cystic fibrosis, individuals have problems with decreased salt, and hence, water levels in their lung surfactent. They also have problems with salt absorption in the sweat ducts which causes them to produce extremely salty sweat, with a high chloride level. Sweat chloride testing is still the gold standard for screening for cystic fibrosis.
A sample of cerebrospinal fluid is diluted 1:100; the standard 9 squares of a hemocytometer were counted on each side for a total of 18 large squares. Side 1- 186 cells counted Side 2- 184 cells counted total cells = 370 What is the cell count per microliter?
In this example, we would use the standard manual WBC count equation. Cells/µL = # of cells counted x dilution / # of large squares counted x 0.1µL (chamber depth) In this case, Cells/µL = 370 x 100 / 18 x 0.1 Cells/µL = 37000 / 1.8 Cells/µL = 20556 or 2.06 x 10^4
What two glycoproteins are expressed on the surface of influenza A viruses and are used for subtyping of the viruses? Hemagglutinin Glycoprotein120 (gp120) Glycoprotein41 (gp41) Neuraminidase
Influenza A viruses are subtyped based on two glycoprotein spikes expressed on their surfaces: 1) Hemagglutinin (HA) 2) Neuraminidase (NA) Gp120 and gp41 are associated with the human immunodeficiency virus.
Which one of the following conditions is NOT associated with hereditary spherocytosis? Increased osmotic fragility An MCHC greater than 37% Intravascular hemolysis Extravascular hemolysis
Intravascular hemolysis does not occur when a patient is suffering from hereditary spherocytosis. Instead, the spleen and liver often remove the spherocytes from circulation; a process called extravascular hemolysis. In spherocytes, the MCHC is increased due the the decreased surface to volume ratio of the red cell. In addition, spherocytes have an increased osmotic fragility.
A quality control program is to be set up for the following tests: Phenylalanine deaminase (PAD) Indole production Voges-Proskauer (V-P) Which pair of stock culture organisms would be MOST suitable to verify the performance of these three tests? P. vulgaris, Escherichia coli Klebsiella pneumonia, Proteus vulgaris E. coli, Enterobacter aerogenes E. aerogenes, K. pneumonia Bacillus anthracis, Yersinia pestis
Klebsiella pneumonia and Proteus vulgaris would be MOST suitable to verify the performance of these three tests. K. pneumonia = PAD -, indole -, VP + P. vulgaris = PAD +, indole +, VP -
A routine laboratory workup is ordered for an outpatient. The patient's lipid results are as follows: Total cholesterol = 295 mg/dL HDL = 30 mg/dL Triglycerides = 200 mg/dL What is the LDL cholesterol level for this patient?
LDL cholesterol = Total cholesterol - (HDL + (Trig / 5)) In this case, the calculation for LDL would be: LDL cholesterol = 295 mg/dL - (30 mg/dL + (200 mg/dL / 5)) LDL cholesterol = 295 mg/dL - 70 mg/dL = 225 mg/dL
AFP is a tumor marker associated with tumors of what origin?
Liver
The Mycobacterium species capable of growing on modified MacConkey agar (crystal violet removed from the formula is:
Mycobacterium fortuitum The ability to grow on modified MacConkey agar, from which the crystal violet has been removed, is a differential culture medium helpful in separating the rapidly growing M. fortuitum and most strains of M. chelonae (growth) from other Mycobacterium species (no growth). Although about 25% of strains of M. smegmatus can grow on modified MacConkey agar, neither M. avium/intracellulare, M. kansasii, nor M. marinum, have this property.
Which of the following cardiac biomarkers rises within 30 minutes - 4 hours after chest pain, peaks in 2 - 12 hours, and is usually normal within 24 - 36 hours. Cardiac troponins CK-MB Myoglobin
Myoglobin
Normal pH of semen must be a value equal to or greater than which of the following? 5.5 6.5 7.2 8.0
Normal pH of semen is a value greater than 7.2.
The tube to the left is a slant of esculin medium, the tube to the right contains heart infusion broth with 6.5% sodium chloride. The bacterial species characteristically producing the positive reactions seen in each of these tubes is most likely: Staphylococcus aureus Streptococcus bovis Enterococcus faecalis Listeria monocytogenes
Of the bacterial species listed in this exercise, only Enterococcus faecalis hydrolyzes esculin (black color in the medium) and can grow in culture medium containing 6.5% sodium chloride (turbid broth and yellow color). Staphylococcus aureus can grow in 6.5% sodium chloride, but does not hydrolyze esculin. Both Streptococcus bovis and Listeria monocytogenes hydrolyze esculin, but neither will grow in a 6.5% sodium chloride.
What has happened in a titer, if tubes #5-7 show a stronger reaction than tubes #1-4? poor technique postzone reaction prozone reaction equivalence reaction technical error
Prozone reaction By definition, prozone is a phenomena occur in immunological reactions when the concentrations of antibody are so high that the optimum concentration for maximal reaction with antigen is exceeded. Immunological phenomena in the prozone region may show partial or total inhibition. Since this is the case in the question, there is a partial inhibition in tubes 1-4 where the antibody is in higher concentrations causing the prozone effect. In tubes 5-7, the antibody concentration is less, therefore there is no prozone effect and a stronger reaction will then occur in these tubes.
Antibodies in the Rh system typically exhibit which one of the following characteristics? Reacts best at 37ºC and AHG Reacts best at room temperature Shows hemolysis better than agglutination
Rh antibodies typically react the strongest at 37 degree temperatures and during the AHG phase of typing.
Which method remains the "gold standard" for ANA detection? Radioimmunoassay (RIA) Lateral Flow Immunoassay Enzyme Immunoasay (ELISA) Slide-based immunofluorescent assay (IFA) or Colorzyme®
Slide-based ANA tests using HEp-2 or HEp-2000® cells are the gold standard. Dozens of different antibodies can be detected using slide-based assays. Solid phase assays such as bead and ELISA assays lack sensitivity, resulting in an unacceptable number of false negative results. RIAand Lateral flow are not methods used for ANA testing.
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'
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 increased risk.
Deviations from Beer's Law are caused by: very low concentration of absorbing material polychromatic light very high concentrations of substance being measured in a colorimetric reaction stray light
Stray light Beer's law is based on the fact that absorbance is directly proportional to the concentration of a solution. Therefore, stray light can alter the absorbance results in this type of assay.
Which immune elements are involved in a POSITIVE TB skin test? IgE T cells and macrophages Nkcells and IgG antibodies B cells and IgM antibodies Epithelial skin cells
T cells and macrophages When the tuberculosis (TB) skin test is performed, the T-lymphocyte cells with receptor sites for tuberculosis antigens will produce a positive test result. The T-lymphocytes secrete cytokines which attract macrophages to the site of the skin test. Together these cells cause the swelling pattern to occur in the characteristic positive skin test.
Beta HCG is a tumor marker associated with tumors of what origin?
Testicles
The beta hemoglobin chain loci are found on which chromosome? Chromosome 11 Chromosome 16
The beta hemoglobin chain loci are found on chromosome 11, along with delta and gamma. Alpha and zeta hemoglobin loci are found on chromosome 16.
The profusion of tiny microconidia lining up along the hyphae in this photomicrograph is characteristic of which of the following organisms? Epidermophyton floccosum Trichophyton verrucosum Trichophyton rubrum
The correct answer is Trichophyton rubrum. The tiny microconidia are lined up in a "birds on the fence" arrangement along the hyphal strand transversing the field of view (yellow arrows). Two pencil-shaped, smooth walled macroconidia are also seen in the lower left field of view (red arrows). Trichophyton verrucosum may produce microconidia in small quantities. However, they are irregularly arranged with little tendency to line up along the hyphae. Antler hyphae and string bean macroconidia are characteristic of this species. One of the key characteristics in the identification of Epidermophyton floccosum is the inability of this dermatophyte to produce microconidia. Two to four-celled, club-shaped macroconidia are produced, usually in clusters of two or three.
The purpose of C3a, C4a, C5a, the split-products, of the complement cascade is to: bind with specific membrane receptors of lymphocytes and cause release of cytotoxic substances. cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils. bind with membrane receptors of macrophages to facilitate phagocytosis and the removal of debris and foreign substances. regulate and degrade membrane cofactor protein after activation by C3 convertase.
The purpose of C3a, C4a, C5a, the split-products, of the complement cascade is to cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils. C3a, C4a and C5a, bioactive fragments of the complement components C3, C4 and C5, respectively play a key role in mediation of immunologically provoked inflammatory responses. C4a production results from classical pathway activation while, C3a and C5a are produced by the activation of the classical pathway and/or the alternative pathway.
T/F : (1) motility agar (note subsurface flare shown by arrows); (2) esculin hydrolysis (+), and (3) VP (+). The reactions illustrated here are sufficient to rule out Erysipelothrix rhusiopathiae.
True Erysipelothrix rhusiopathiae may have colony and Gram stain features similar to that of Listeria monocytogenes. However, L. monocytogenes is motile (optimum at room temperature or 25C), hydrolyzes esculin (black), and gives a positive VP reaction (red). E. rhusiopathiae is negative for all these tests. E. rhusiopathiae produces H2S in Kligler and Triple Sugar Iron Agar while L. monocytogenes does not.
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) Healthy condition Uncompensated metabolic acidosis Compensated metabolic acidosis Uncompensated respiratory acidosis
Uncompensated metabolic 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.
Isolation and detection of Gardnerella vaginalis from vaginal secretions is improved by which of the following? utilization of human blood agar incubation at 35-37ºC cold enrichment utilization of Thayer-Martin agar
Utilization of human blood agar Human blood agar is an enriched media that supports the growth of Gardnerella vaginalis. The media usually contains 5% human blood without the presence of inhibitors. G. vaginalis produces a characteristic diffuse beta-hemolysis in the presence of human blood, and can therefore be distinguished from other similar-appearing organisms.
The Western Blot Assay is used as a confirmatory test for which of the following: HBsAg CMV Antibody Anti-HCV Anti-HIV-1
Western blot testing is the gold standard for anti-HIV-1 confirmation.
According to the Michaelis-Menton kinetics theory, when a reaction is performed in zero-order kinetics: The substrate concentration is very low and the reaction rate is dependent on the substrate concentration The substrate concentration is in excess and the reaction rate is dependent on the enzyme concentration The enzyme concentration is in excess and the reaction rate is dependent on the substrate concentration The substrate concentration is equal to Km and the reaction rate is dependent on the enzyme concentration
Within the Michaelis-Menton kinetics theory, when a reaction is performed in zero-order kinetics the substrate concentration is in excess and the reaction rate is dependent on the enzyme concentration.
When performing an antibody panel, which one of the following antigens will be rendered inactive by enzyme treatment? anti-Fya anti-Jka anti-E anti-Lua
anti-Fya Duffy antigens are rendered inactive by enzyme treatments since the enzyme will remove the sialic acid from the RBC membrane. This process destroys: M, N, S, s, and Duffy antigens. The process enhances the reactions for Rh, Kidd, Lewis, I, and P antigens.
Mrs. Jones, a diabetic, is admitted to the hospital on November 25th. It appears that she has had an AMI but did not feel the severe chest pain because of diabetic neuropathy. She has not felt well since November 20th and her physician believes she possibly had an AMI on November 20th. Assuming that the infarct was uncomplicated, which of the following cardiac biomarkers would most likely still be elevated and would assist in an AMI diagnosis? Myoglobin Creatine kinase MB (CK-MB) Cardiac troponin I (cTnI) or cardiac troponin T (cTnT)
cTnI and cTnT remain elevated after an AMI for 10-14 days. Myoglobin returns to normal range in 24-36 hours and CK-MB is back to normal range in 48-72 hours.
The Red cell Distribution Width (RDW) in alpha thalassemia is within normal limits usually increased usually decreased dependent upon severity
dependent upon severity The red blood cell distribution width (RDW) increases as the severity of alpha thalassemia increases because of changing MCV as the bone marrow produces smaller cells. In addition, if Hemoglobin H bodies are present, they result in the formation of schiztocytes (RBC fragments) that can have an effect on the MCV and RDW.
Increased concentrations of alpha-fetoprotein (AFP) in adults are MOST characteristically associated with: hepatocellular carcinoma alcoholic cirrhosis chronic active hepatitis multiple myeloma
hepatocellular carcinoma
