ASCP Review
A physician called the microbiology laboratory and asked what he needed to order to diagnose Bordetella pertussis from a child who had what appeared to be having whooping cough. Which of the following should the physician be told to order? Direct fluorescent antibody (DFA) test only Culture only Both direct fluorescent antibody (DFA) test and culture IgG and IgM antibody tests
Both direct fluorescent antibody (DFA) test and culture Both direct fluorescent antibody (DFA) test and culture is the correct answer because the DFA is a rapid test and can provide a faster turn around time; however, the DFA test does have limited sensitivity and variable specificity; therefore, to ensure a more accurate diagnosis, a culture should be performed along with a DFA test from a nasopharyngeal specimen. Direct fluorescent antibody (DFA) test only is incorrect because DFA has limited sensitivity and variable specificity, when used alone to diagnosis a case of Bordetella pertussis. Culture only is incorrect because a culture can take up to 12 days to grow; however, growth can be detected as early as 2-7 days. Culture alone has 100% specificity and 100% sensitivity, but the stage of disease, specimen collection techniques, quantity of specimen obtained, and transportation conditions can all affect the sensitivity of the culture. IgG and IgM antibody tests is incorrect because this method of testing can also take several days depending on if the test is performed in-house or sent out. Serological tests are available; however, the most reliable serological test to diagnose Bordetella pertussis is the pertussis toxin antibody test for acute and convalescent specimens.
Which of the following phenotypes is most indicative of a natural killer (NK) cell? CD2+ CD3+ CD5+ CD7+ CD2+ CD3- CD11b+ CD16+ CD11b+ CD16+ CD33+ CD56- CD19+ CD20+ CD22+ CD57-
CD2+ CD3- CD11b+ CD16+ NK cells express CD2, CD11b, and CD16; NK cells do not express CD3, a T cell marker. Other NK cell markers include CD7, CD56, and CD57. CD2, CD3, CD5, and CD7 are all mature T cell markers. CD2 and CD7 are also NK cell markers; however, NK cells are CD3- and CD5-. Although NK cells express CD11b and CD16, CD33 is expressed by monocytes and other myeloid cells. NK cells are CD56+. CD19, CD20, and CD22 are all B cell markers. NK cells are CD57+
A culture was performed on a stool sample. After growth was obtained on the blood agar plate, the gram stain showed curved gram-negative rods. The oxidase, catalase, and urease were positive. What is the most likely bacterial identification? Helicobacter pylori Campylobacter concisus Helicobacter cinaedi Arcobacter spp.
Helicobacter pylori Identification methods for curved gram-negative rods will include (in this order) oxidase, catalase, and urease. Helicobacter pylori will have the gram stain showing curved gram-negative rods. It will have positive results for oxidase, catalase, and urease. Campylobacter concisus will have the gram stain showing curved gram-negative rods. It will have positive results for oxidase along with a negative catalase result. Helicobacter cinaedi will have the gram stain showing curved gram-negative rods. It will have positive results for oxidase and catalase along with a negative urease test. Arcobacter spp. will have the gram stain showing curved gram-negative rods. It will have positive results for oxidase and catalase along with a negative urease test.
Which of the following is the most common condition associated with a nonmegaloblastic macrocytic anemia? Liver disease Aplastic anemia Chronic blood loss Folic Acid deficiency
Liver disease The most common condition associated with nonmegaloblastic macrocytic anemia is liver disease, including cirrhosis due to alcoholism.While aplastic anemia can appear macrocytic, it is often normocytic.Anemia due to chronic blood loss is typically macrocytic.Folic Acid deficiency can lead to macrocytic anemia but is megaloblastic, not nonmegaloblastic.
Isoenzymes of CK include all of the following EXCEPT: MB MM MBM BB
MBM CK-BB is found mainly in the brain and lungs. CK-MB is found mainly in the heart. CK-MM is found mainly in skeletal muscle. There is no such thing as CK-MBM
Which of the following methods may be used by a laboratory to document and analyze all of the steps that bring a laboratory test result to the customer (eg, physician, nurse, and/or patient)? Root cause analysis Value stream mapping 5S Kaizen workshop
Value Stream Mapping Value stream mapping is a Lean process that can be used by laboratory personnel to document and analyze all of the steps that bring a laboratory test result (product or service) to the customer. Root cause analysis is a method that is used to determine what caused a quality or performance problem for the purpose of correcting the primary cause of the problem. 5S is a Lean quality improvement method that, if followed, will create a safe and efficient work environment. Kaizen workshops are short-term events used to introduce lean tools and techniques.
How does the modified acid-fast stain differ from the conventional acid-fast stain? Heat Detergent Methylene blue Carbolfuchsin
detergent. The modified acid-fast stain (Kinyoun stain) utilizes a surface-active detergent, such as Tegitol, and the conventional acid-fast stain (Ziehl-Neelsen stain) uses heat to penetrate the waxy material of acid-fast bacilli. Both acid-fast stains use carbolfuchsin as the primary stain, acid-alcohol as the decolorizer, and methylene blue as the counterstain. The Kinyoun stain is most commonly used because it does not require the added danger of heat application, but some weakly acid-fast positive organisms may be missed, as the detergent does not allow the carbolfuchsin to penetrate the waxy cell wall as well as heat.
Which of the following tumor markers is associated with testicular cancer? PSA CEA Beta hCG CA-125
beta hCG, or Human chorionic gonadotropin = Testicles PSA, or prostate specific antigen = Prostate CEA, or Carcinoembryonic Antigen = Colon CA-125 = Ovarian tumors
If septic arthritis is suspected, specimens from which of the following normally sterile sites should be collected to detect the microorganism causing the condition? Serous fluid Synovial fluid Cerebrospinal fluid (CSF) Blood
synovial fluid. Synovial fluid is the fluid that gives lubrication to the joint and provides nourishment for articular cartilage. It would likely grow the microorganism causing the septic joint. Serous fluid consists of three fluids: pleural fluid, pericardial fluid and peritoneal fluid. Each fluid is contained in the space between the inner (visceral) and outer (parietal) membranes of the lings, heart and abdomen, respectively. CSF is present in the subarachnoid space and provides cushion for the central nervous tissue. Blood may allow for detection of a microorganism, but it would not be the definitive cause of the septic arthritis.
When collecting routine blood product donations, the venipuncture site is first cleaned with: 70% Isopropyl alcohol 50% Iodine 0.7% Iodophor compound 2% Chlorhexidine
0.7% Iodophor compound A 0.7% iodophor compound is used as the first disinfectant method as it removes surface debris and bacteria and can begin the initial germicidal action on resident skin bacteria. 70% isopropyl alcohol is sufficient to be used in routine venipuncture procedures, but extra germicidal action is needed for resident skin bacteria when collecting blood donations to prevent contamination. 70% isopropyl alcohol should not be used alone or as the first step when preparing a venipuncture site for blood donations. 50% Iodine is not used as an antiseptic as it commonly causes skin irritation. A 10% povidone-iodine solution is used as a secondary antiseptic for blood donation venipunctures, following 0.7% iodophor compound. 2% Chlorhexidine may be used to cleanse the skin in venipunctures for blood donors who are sensitive to the iodophor and povidone-iodine solutions. Venipuncture sites for individuals who are sensitive to iodine-based compounds should then be cleaned with 70% isopropyl alcohol. This process is not typically used as it takes longer to clean the skin and has demonstrated improved germicidal action when compared to the iodophor and povidone-iodine procedure.
With regard to blood cultures, which blood to broth ratio is most conducive to growth? 1 : 1 1 : 2 1 : 10 10 : 1
1: 10 Blood is generally inoculated into broth in a ratio of 1 part blood to 5 to 10 parts broth, to dilute antibacterial activity of serum. However, at least 10 mL up to 30 mL of blood per draw should be obtained. Generally, the greater the volume, the greater the yield of bacterial organisms. This is particularly important in febrile patients with suspected endocarditis, and immunocompromised patients. A 1:1 ratio (one part blood to one part broth) does not dilute the serum sufficiently to dilute or inactivate the antibacterial components of the blood. A 1:2 ratio (one part blood to two parts broth) does not dilute the serum sufficiently to dilute or inactivate the antibacterial components of the blood. A 10:1 ratio (ten parts blood to one part broth) provides a sufficient amount of blood but not enough broth to dilute or inactivate the antibacterial components of the blood.
What is the lower reference limit for progressive motility of spermatozoa when performing a semen analysis? 12% 22% 32% 40%
32% WTO grades sperm motility as progressive motility (PM), nonprogressive motility (NP), and immotility (IM). PM is defined as sperm moving linearly or in a large circle, NP is sperm moving without progression, and IM represents sperm with no movement. The lower reference limit for progressive motility is 32%. The lower reference limit for total motility (progressive + non-progressive) is 40 %.
What is the shelf-life of whole blood collected in CPDA-1? 21 days 28 days 35 days 48 days
35 days Whole blood collected with CPDA-1, or citrate-phosphate-dextrose-adenine, has a storage (shelf) life of 35 days from the date of collection. Whole blood collected with CPD (citrate-phosphate-dextrose), CP2D (citrate-phosphate-dextrose-dextrose), or ACD (acid-citrate-dextrose) has a storage (shelf) life of 21 days from the date of collection.
A unit of leukocyte-reduced red blood cells must retain at least what percentage of red blood cells following leukoreduction? 65% 75% 85% 95%
85% The American Association of Blood Banks (AABB) standards state that a unit of leukocyte-reduced red blood cells must contain at least 85% of the red cells as the original unit. Units containing 65% or 75% of red blood cells would not meet this standard of quality. Units containing 95% of red blood cells exceed the minimum standard, not the minimum percentage required for red blood cells following leukoreduction.
When processing umbilical cord blood samples for hematopoietic progenitor cells (HPC), what tests are performed on both the mother's blood and cord blood? ABO & Rh HIV-1 & HIV-2 HBV & HCV HTLV-I & HTLV-II
ABO & Rh Umbilical cord blood requires special processing. Both the mother's blood sample and the cord blood are tested for ABO and Rh. The maternal sample will have an antibody screen performed along with testing for HIV-1 & HIV-2, HBV & HCV, and HTLV-I & HTLV-II. Also, HBsAg, anti-HBc, and syphilis status is determined. The cord blood is cultured for cytomegalovirus.
Which of the following statements is true regarding anti-nuclear antibodies? They are highly specific for patients with systemic lupus erythematosus 95% of patients with SLE will test positive for ANAs Reactions using HEp-2 cells will demonstrate diffuse, speckled, peripheral and starburst patterns Results are diagnostic with no further testing necessary
ANAs can be found in several conditions including Rheumatoid arthritis, Scleroderma and Sjögren's syndrome. 95% of patients will test positive for ANAs as patients are creating autoantibodies that react to different nuclear, nucleolar and perinuclear antigens like nucleic acids, histones, chromatin and nuclear anti-ribonuclear proteins. While diffuse, specked and peripheral patterns are found in FANA testing with HEp-2 cells there is no pattern identified as starburst. Because there are several other autoimmune conditions that will have positive ANAs further confirmatory testing is required, and usually ELISA testing is performed
The following polypeptide chains are found in normal adult hemoglobin A: Alpha and gamma Alpha and delta Beta and delta Alpha and beta
Alpha and Beta A normal hemoglobin molecule is a tetramer made up of two alpha and two beta chains. A fetal hemoglobin molecule is a tetramer made up of two alpha and two gamma chains. Hemoglobin A2 is a tetramer made up of two alpha and two delta chains. Beta and delta globin genes reside in close proximity on the same arm of chromosome 11. The two do not assort together. However, 2 delta and two alpha globin chains form HbA2. Only a limited amount of delta chain is synthesized, limiting the amount of HbA2. In a normal adult, HbA2 accounts for about 2.5% of total adult hemoglobin.
Which of the following antibiotics inhibits protein synthesis by binding to the 30S ribosomal subunits and provides coverage against Gram positive and Gram negative aerobes? The correct answer is highlighted below Beta-lactams Aminoglycosides Fluoroquinolones Polymyxins
Aminoglycosides is the correct answer because this group of antibiotics inhibits bacterial protein synthesis by irreversibly binding to protein receptors on the 30S ribosomal subunit. Blood levels for this group of antibiotics must be monitored to prevent nephrotoxicity. Examples of antibiotics in this class are gentamicin, tobramycin, amikacin, streptomycin, and kanamycin. Beta-lactams is incorrect because this group inhibits cell wall synthesis by binding enzymes involved in the production of peptidoglycan such as penicillin-binding proteins (PBP). This group provides coverage against both Gram positive and Gram negative bacteria, but can vary depending on each individual antibiotic. Examples of antibiotics in this class is penicillin, ampicillin, and piperacillin. Fluoroquinolones is incorrect because this group inhibits DNA synthesis by binding DNA gyrase and topoisomerase IV. This group has coverage against Gram positive and Gram negative bacteria. Examples of antibiotics in this group are ciprofloxacin, levofloxacin, and ofloxacin. Polymyxins is incorrect because this group disrupts the cell membrane. This group has coverage against Gram negative bacteria only. Examples of antibiotics in this group are polymyxin B and colistin.
All of the following are the reacting substances that may be in the Coombs sera (antihuman globulin) EXCEPT? Monoclonal antibody sources Polyclonal antibody sources Complement antibodies (e.g. anti-C3b) Anti-IgM sources
Anti-IgM sources Two categories of antiglobulin reagents exist: polyspecific and monospecific. The reagents can either be monoclonal antibody products or polyclonal antiserum products. Several reagent preparations are commercially available for polyspecific products derived from either polyclonal or monoclonal antibody sources. Other complement antibodies may also be present, including anti-C3b.IgM is not a reacting substance in Coombs sera.
A gram-negative coccobacillus produces small gray colonies surrounded by a zone of hemolysis on potato-blood-glycerol agar. The organism also grew on chocolate agar, but NOT on sheep blood agar. This is MOST likely to be which organism? Alcaliqenes fecalis Bordetella pertussis Franciscella tularensis Hemophilus influenzae
Bordetella Pertussis In this case, the organism is most likely Bordetella pertussis. This bacterium grows well in glycerin-potato-blood agar, also known as Bordet Gengou agar, which is selective for B. pertussis and B. parapertussis. These organisms show a slower growth pattern, most usually requiring from three to seven days after incubation. The colonies are beta-hemolytic, small and dome-shaped, possessing a gray metallic look, sometimes similar to mercury droplets.
Which of the following is the primary virulence factor in Streptococcus pneumoniae? Lipoteichoic acids Capsular polysaccharide M protein Protein A
Capsular polysaccharide The chief virulence factor for Strep pneumoniae is the production of a polysaccharide capsule that prevents ingestion by phagocytic cells. Enterococcus faecalis has lipoteichoic acids in its cell wall that induces production of tumor necrosis factor and interferon, both of which suppress the immune response. The M protein in the cell wall of Strep pyogenes also inhibits phagocytosis. The Protein A in the cell wall of Staphylococcus aureus also inhibits ingestion by segmented neutrophils but also elicits an immediate and delayed hypersensitivity reaction.
Which of the following can produce indole? Chryseobacterium spp. Sphingomonas paucimobilis Chryseomonas luteola Flavimonas oryzihabitans
Chryseobacterium spp. Among the nonfermentative gram negative bacilli, the only ones capable of producing indole are Chryseobacterium spp., Elizabethkingia meningoseptica, and Empedobacter brevis. The reaction is often weak, requiring extraction with an organic solvent before adding Ehrlich's reagent. All of the other nonfermenters listed in this question are indole negative.
Thymic hypoplasia is a/an: Congenital T-cell disorder Congenital B-cell disorder Acquired T-cell disorder Acquired B-cell disorder
Congenital T- cell disorder Thymic hypoplasia, also known as DiGeorge syndrome or 2211.2 deletion syndrome, is a disorder resulting from a mutation in chromosome 22. This T-cell defect is a congenital anomaly producing faulty embryogenesis of the endodermal derivation of the third and fourth pharyngeal pouches, which results in aplasia of the parathyroid and thymus glands. Bruton's agammaglobulinemia is a classic example of an X-linked congenital B-cell disorder. A variant in the gene coding for the enzyme Bruton tyrosine kinase leads to the arrest of B-cell development at the pre-B cell stage of cellular development. One of the most well-known acquired T-cell disorders is Acquired Immunodeficiency Syndrome (AIDS). The human immunodeficiency virus (HIV) has a marked preference for the CD4+ subset of T-lymphocytes. Multiple conditions can create an acquired B-cell disorder. Autoimmune disorders and Multiple Myeloma are two examples. Other acquired B-cell deficiencies can be related to conditions such as aging and the effect of various medications.
Essential components of compatibility testing include all of the following EXCEPT: Antibody screen on recipient's serum Major crossmatch or computer crossmatch ABO and Rh typing of recipient Direct Antiglobulin Test (DAT)
Direct Antiglobulin Test (DAT) A direct antiglobulin test (DAT) is used to detect in-vivo sensitization of red blood cells with IgG or complement components. Cases in which this test is used include hemolytic disease of the fetus and newborn, hemolytic transfusion reaction, and autoimmune or drug-induced hemolytic anemia. AABB Standards do not require a DAT for pretransfusion testing. Studies have looked into whether or not a routine DAT would benefit patient outcomes and have shown that they do not have a positive impact on the patients. All recipients have compatibility testing, including ABO grouping, Rh typing, antibody screen, and a crossmatch.
The egg is the infective stage of this parasite for humans. What is the identification of this organism? Enterobius vermicularis Taenia solium Trypanosoma cruzi Schistosoma mansoni
Enterobius vermicularis (also known as Pinworm) infects humans after ingestion of eggs. The eggs migrate to the digestive tract, to the small intestine, where they hatch and release larvae. Although Schistosoma mansoni and Taenia solium have eggs in their corresponding life cycles, this form is not the infective stage for human infections. Taenia solium infects humans after ingestion of pork contaminated with cysticercus larva. This larva consists of a scolex surrounded by a thin-walled cyst filled with fluid. The larvae will emerge in the small intestine, mature, and release eggs. Those eggs are consumed by the animal species (pig), in which the larva will deposit in the tissues. Trypanosmoa cruzi does not have an egg stage at all. T. cruzi is a hemoflagellate and requires an arthropod vector (the reduviid bug) for transmission. When the bug bites a human, infective trypomastigotes are deposited next to the bite. Humans will scratch the bite and rub these into the area and into the host. Schistosoma mansoni infection occurs through the water-residing cercaria, which enters the human body by drilling into the skin. They migrate to the bloodstream where they mature and reside in the veins surrounding the intestinal tract. The females lay eggs. The eggs reach water and release the miracidium that must find a snail host to develop into cercaria. The egg is not the infective form for humans.
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 is the correct answer because the RPR (Rapid Plasma Reagin) is a non-treponemal test that can produce false-positive results due to the nonspecific nature of the antigen used. If the RPR was truly reactive due to Treponema pallidum, the FTA-ABS (Fluorescent treponemal antibody absorption test) should be positive. The FTA-ABS is a confirmatory test for syphilis infections. Primary syphilis is incorrect as the RPR and FTA-ABS tests should both be positive during primary infection. Secondary syphilis is incorrect as the RPR and FTA-ABS tests should both be positive during a secondary infection; however, during secondary infections, false negatives can occur with the RPR tests because of prozone (antibody excess). Latent syphilis is incorrect because the RPR and the FTA-ABS test should be positive. If the patient has been treated, the RPR may be non-reactive, but the FTA-ABS would remain positive.
ACTH controls which step of steroid hormone production? First step (cholesterol to cholesterol esters) First step (cholesterol esters to cholesterol) Second step (cholesterol to pregnenolone) Third step (cholesterol esters to pregnenolone)
First step (cholesterol esters to cholesterol) ACTH controls the first step of steroid hormone production, causing cholesterol esters to convert to cholesterol before the subsequent formation of other steroid hormones.
The anemia seen in anemia of chronic disease (also known as anemia of chronic infection) is characterized by low serum iron levels. Which of the following contributes to the low serum iron levels seen in persons with anemia of chronic disease? Decreased erythropoietin Hepcidin Decreased dietary intake Decreased ferritin levels
Hepcidin The correct answer is hepcidin. Decreased serum iron levels seen in anemia of chronic disease are due to increased hepcidin, which is responsible for blocking the release of iron from macrophages. Hepcidin is produced in response to inflammatory cytokines.Erythropoietin (EPO) levels can be decreased in anemia of chronic disease, but the level of EPO would not contribute to the level of serum iron.The dietary intake of iron is not correct. Decreased serum iron levels are due to the role of hepcidin.Ferritin levels in anemia of chronic disease are often increased, not decreased.
All of the following are true about hybridization in PCR procedures, EXCEPT? Hybridization cannot happen between a strand of DNA and a strand of RNA Hybridization is the process of single strands of nucleic acid bonding together to form double strands Hybridization can also be called annealing Complementary bases link together with hydrogen bonds
Hybridization cannot happen between a strand of DNA and a strand of RNA Hybridization or annealing is the process of binding known nucleic acid strands to the unknown for synthetization of complementary strands. This can occur between a strand of DNA and a strand of RNA. Complementary bases link by hydrogen bonds to create the DNA double helix. The process of complementary single strands of DNA to form into double stranded DNA is called hybridization or annealing.
What kind of immunoglobulins are predominantly found in Rh immune globulin? IgM anti-D IgG anti-D IgM anti-A,B IgG anti-A,B
IgG anti-D Rh immune globulin is a solution of concentrated anti-D. It is prepared from pooled human plasma of patients who have been hyperimmunized and contains predominantly IgG anti-D. Because RhIg contains IgG anti-D, it can cross the placenta and sensitize fetal Rh positive red cells. Affected infants may be born with a weakly positive DAT, but significant hemolysis does not occur.
When should blood samples for trough drug levels be collected? 30 minutes after peak levels 45 minutes before the next dose 1-2 hours after the last dose Immediately before the next dose is given
Immediately before the next dose is given The trough drug level is drawn immediately before the next dose is given as the drug level is expected to be the lowest in the body at this point.
Blood culture bottles used in continuous monitoring systems, such as the BacTec, uses resins or charcoal to do which of the following? Inactivates and absorbs out complement Inactivates and absorbs out coagulation factors Inactivates neutrophils and monocytes Inactivates and absorbs out antimicrobial agents
Inactivates and absorbs out antimicrobial agents is the correct answer because resins and charcoal are able to absorb out and inactivate antimicrobial agents, which will enhance the recovery of microorganisms. However, when reading Gram stains from bottles that use charcoal, caution should be used as the charcoal can be misinterpreted as Gram positive cocci.
In theory, how difficult is it to find a compatible blood unit and to identify the antibody in a patient with an antibody to a low-frequency antigen, such as Kpa or Jsa? It is difficult to find compatible blood and difficult to identify the antibody It is difficult to find compatible blood but not difficult to identify the antibody It is not difficult to find compatible blood but difficult to identify the antibody It is not difficult to identify the antibody and not difficult to find compatible blood
It is not difficult to find compatible blood but difficult to identify the antibody Low-frequency antigens are not often found in the population and maybe as rare as <1% of the population. Because of this, it is not difficult to find compatible units for a patient with the corresponding antibody since few people would possess the antigen. However, identifying the antibody would be difficult since the corresponding antigen would not be found on many reagent red cells, making the Rule of Three difficult to accomplish.
In almost all cases of polycythemia vera, which of the following genetic abnormalities is present? Philadelphia chromosome JAK2 mutation BCR/ABL1 t(15:17)(q22;q12)
JAK2 mutation The JAK2 mutation is present in over 95% of cases of polycythemia vera. This mutation causes a mutated tyrosine kinase activator.The Philadelphia chromosome is found in the majority of cases of chronic myelogenous leukemia.BCR/ABL1 is a fusion gene and is associated with the Philadelphia chromosome and chronic myelogenous leukemia.t(15:17)(q22;12) refers to the abnormality found in acute promyelocytic leukemia, also referred to as AML with t(15;17)(q22;12).
Which one of the following procedures is used for the proper preparation of platelet concentrate from random whole-blood donors? Light spin followed by a hard spin Light spin followed by two hard spins Two light spins Hard spin followed by a light spin
Light Spin followed by a hard spin The first step in the preparation of platelets from random whole blood donors is low-speed centrifugation (light spin). This allows the platelets to remain in the plasma portion of the collection container. The plasma (dubbed "platelet-rich plasma") is then centrifuged at a higher velocity (hard spin) that forces the platelets to the bottom of the satellite bag. The platelet-poor plasma is expressed into another container, and the residual platelets that remain in the bag are resuspended in a small volume of plasma.
How are Barr bodies usually classified? Pathological Reactive Non-pathological Atypical
Non-pathological A Barr body is the drumstick-shaped inactive X-chromosome attached to a nuclear lobe of some granulocytes in peripheral blood smears from females. This morphologic change is considered non-pathological.
To determine if xanthochromia is present in a cerebrospinal fluid sample, the sample must be centrifuged within: One hour Two hours Three hours Four hours
One Hour Xanthochromia is the pink, yellowish, or orange discoloration of the CSF mostly due to the presence of RBC degradation. If tubes are left to sit too long, the red cells can lyse causing hemolysis in the tube which can appear similar to xanthochromia.
A white blood cell stained with Wright's stain has the following characteristics: Round eccentric nucleus with clumped chromatin pattern 1:1 nucleus to cytoplasm ratio Basophilic cytoplasm Crescent-shaped clear area next to nucleus What is the MOST likely identification of this cell? Myeloblast Plasma cell Reactive lymphocyte Polychromatic normoblast
Plasma cells, which produce immunoglobulin, characteristically show a "halo" next to the nucleus, which is a crescent-shaped lighter colored region of the cytoplasm. The eccentric nucleus and the 1:1 nucleus to cytoplasm ratio with basophilic cytoplasm are also typical characteristics of plasma cells. Plasma cells are seen most commonly in patients with conditions such as multiple myeloma, plasmacytoma, plasma cell leukemia, Waldenström macroglobulinemia, and malignant neoplasms. The nuclear chromatin of a myeloblast is finely reticular and has one to five nucleoli with a small rim of basophilic cytoplasm. In general, reactive lymphocytes have a lobulated enlarged nucleus and may have clefts or folds. The overall cell size is increased. The chromatin pattern can vary from coarsely granular to fine. The amount of cytoplasm is increased and can range from gray to light blue or an intense blue color. Polychromatic normoblasts or rubricytes are red blood cell precursors. Rubricytes do have a 1:1 nucleus to cytoplasm ratio, but the cytoplasm has a pink color mixed with basophilia.
Donation of which apheresis blood product more than once every four weeks requires monitoring of total plasma protein and antibody levels? Red cell apheresis Platelet pheresis Plasmapheresis Leukapheresis
Plasmapheresis Plasma levels of total protein, IgG, and IgM levels must be monitored every four months in plasmapheresis donors because levels of these and other proteins present in plasma decrease following plasmapheresis. Blood components from red cell apheresis, plateletpheresis, and leukapheresis do not contain enough volume of plasma to necessitate the monitoring of plasma proteins.
The MOST accurate observation about osmotic pressure is that it is: Proportional to concentration of solute particles Equal to number of solvent molecules times a factor Measurable by how much it raises the freezing point of water Directly proportional to the inverse log of solvent molecules
Proportional to concentration of solute particles The osmotic pressure does not depend on the solute type or its molecular size but only on its molar concentration, the concentration of solute particles. There is no factor involved nor inverse log involved in the osmotic pressure in relation to the solvent molecules in the sample. Osmolality is measurable by how much it depresses the freezing point of samples.
Which potent inhibitor of platelet aggregation is released by endothelial cells? Epinephrine Prostacyclin Ristocetin Thromboxane A2
Prostacyclin is produced by endothelial cells and prevents the formation of the platelet plug involved in primary hemostasis by preventing platelet activation and aggregation as well as inducing vasodilation. Epinephrine (agonist used in platelet aggregation studies), ristocetin (agonist used in platelet aggregation studies), and thromboxane A2 (platelet activator) are not produced by the endothelial cells.
What is a corrective action that can be used to obtain a valid platelet count from a patient specimen that exhibits platelet satellitism on the manual differential? Redraw the patient specimen in another EDTA collection tube and wait 20 minutes before sampling. Refrigerate the patient sample for 30 minutes prior to sampling. Invert the EDTA tube several times prior to sampling. Recollect the blood specimen in a blue top tube containing sodium citrate.
Recollect the blood specimen in a blue top tube containing sodium citrate. If platelet satellitism is observed on the peripheral smear, the sample should be recollected using sodium citrate as the anticoagulant. Platelets can then be counted using the automated method. The platelet count from a tube that contains liquid sodium citrate will need to be corrected for the dilutional effect of the citrate; this can be accomplished by multiplying the platelet count that is obtained from the automated analyzer by 1.1. Any suggested remedy that involves the use of EDTA as the anticoagulant will not be effective because the presence of EDTA is causing the satellitism to occur.
The positive square root of the variance of a set of values is called: Median value Mean value Standard deviation Coefficient of variation
Standard Deviation The standard deviation measures the spread of the data about the mean value. It is useful in comparing sets of data that may have the same mean but a different range. The standard deviation is calculated by taking the positive square root of the variance of a set of values.The median value is the central value in a range of numbers.The mean is the average of a group of valuesThe coefficient of variation is a measure of the dispersion of the data points.
What is the principle of the Kleihauer-Betke test? The Kleihauer-Betke test capitalizes on the resistance of fetal hemoglobin to alkaline treatment. The Kleihauer-Betke test capitalizes on the resistance of fetal hemoglobin to acid treatment. The Kleihauer-Betke test capitalizes on the resistance of fetal hemoglobin to enzymatic treatment. The Kleihauer-Betke test capitalizes on the resistance of fetal hemoglobin to radiation treatment.
The Kleihauer-Betke test capitalizes on the resistance of fetal hemoglobin to acid treatment. The Kleihauer-Betke test is based on the principle that red cells containing adult hemoglobin are more susceptible to acid elution than those containing fetal hemoglobin. A thin smear of maternal blood is treated with acid, rinsed, and counterstained. The maternal red cells, predominately adult hemoglobin, appear as pale 'ghost' cells, and the fetal red cells, predominately fetal hemoglobin, are pink. The principle of the Kleihauer-Betke is not based upon fetal hemoglobin resistance to alkaline treatment, enzymatic treatment, or radiation treatment.
How does the modified acid-fast stain differ from the conventional acid-fast stain? Heat Detergent Methylene blue Carbolfuchsin
The correct answer is detergent. The modified acid-fast stain (Kinyoun stain) utilizes a surface-active detergent, such as Tegitol, and the conventional acid-fast stain (Ziehl-Neelsen stain) uses heat to penetrate the waxy material of acid-fast bacilli. Both acid-fast stains use carbolfuchsin as the primary stain, acid-alcohol as the decolorizer, and methylene blue as the counterstain. The Kinyoun stain is most commonly used because it does not require the added danger of heat application, but some weakly acid-fast positive organisms may be missed, as the detergent does not allow the carbolfuchsin to penetrate the waxy cell wall as well as heat.
Fluoroquinolones, such as ciprofloxacin, work by targeting: Penicillin-binding proteins; disrupting bacterial cell wall synthesis Tetrahydrofolate synthesis; preventing bacterial DNA synthesis Topoisomerases, inhibiting bacterial DNA replication 50S ribosomal subunits, inhibiting bacterial protein translation
Topoisomerases Fluoroquinolones target topoisomerases, enzymes that control DNA replication processes. Penicillin and other ß-lactam antibiotics are cell wall synthesis inhibitors which target penicillin-binding proteins. Sulfonamides are DNA synthesis inhibitors which disrupt the folic acid pathway. Protein synthesis inhibitors, such as macrolides, work by binding to 50S ribosomes.
A hospitalized patient has a decreased serum copper level and increased urine copper level. This is MOST consistent with: Wilson's disease Addison's disease Parathyroid disease Not clinically significant
Wilson disease is a rare inherited disorder that causes the body to retain copper. Serum copper is paradoxically low but urine copper is elevated in Wilson's disease. Copper is deposited in tissues such as hepatic parenchymal cells, brain cells, and the periphery of the iris. Symptoms include hepatitis, neurological disorders, and renal tubular dysfunction. Addison's disease is an endocrine disorder where the adrenal glands do not produce enough steroid hormones. Parathyroid disease is categorized as hyper or hypoparathyroidism, which affects parathyroid hormone and calcium levels. Increased urine copper and decreased serum copper are clinically significant findings.
Which of the following steps comes after writing goals in the instructional planning sequence? Writing objectives Conducting lectures or laboratory exercises Evaluating student performance Planning instructional activities
Writing objectives is the next step in the instructional planning sequence. The steps in the instructional planning sequence are as follows: Identify goals, Write objectives, Choose and implement the learning activity, and Design evaluation tool. Conducting lectures or laboratory exercises is the third step in the instructional planning sequence. Evaluating student performance is the fourth and last step in the instructional planning sequence. Planning instructional activities is part of the third step in the instructional planning sequence.
