Media Lab
What is the largest protozoan known to infect humans?
B. coli
Which of the following protozoa is the largest?
B. coli
Glycine-HCL/EDTA treatment of red cells can destroy which of the following antigens, allowing for confirmation of a suspected antibody and detecting additional antibodies?
Bg and Kell Glycine-HCL/EDTA treatment of red cells can destroy Bg and Kell system antigens.Glycine-HCL/EDTA treatment does NOT destroy Kidd, Ss, or Duffy system antigens.
vIllustrated in the image to the right is a tube of tryptophane agar with a positive indole reaction, as seen by the red ring at the top of the medium. It is necessary to use xylene extraction and Ehrlich's reagent rather than the conventional Kovac's reagent when detecting indole production by which of the following organisms:
Chryseobacterium (Flavobacterium) meningosepticum
Which one of the following sets of laboratory results is consistent with hemolytic anemia?
Decreased erythrocyte survival; increased catabolism of heme; decreased haptoglobin levels Hemolysis is the process of RBC destruction, which leads to decreased erythrocyte survival. Increased catabolism of heme is also associated with RBC destruction. Haptoglobin is decreased since most of it binds to the free hemoglobin released with a red cell is destroyed.\ Lactate dehydrogenase is elevated as the RBCs are being destroyed during hemolysis. Hemoglobinuria can be present during intravascular hemolysis.
A Rh negative individual has produced an anti-D antibody. Which situation has the ability to stimulate this production of anti-D?
Delivering a Rh positive baby.
Stool is the specimen of choice for the recovery of which of the following parasites?
Diphyllobothrium latum
The laboratory test most commonly used to establish a definitive diagnosis of primary syphilis is:
Direct fluorescent antibody test RPR is screening test
Which of the following amoeba cyst measures around 25 µm?
Entamoeba coli Entamoeba coli is correct. Entamoeba coli cyst measure between 10 - 35 µm. Size is an important parasite-identifying feature. It is especially significant in distinguishing Entamoeba histolytica from Entamoeba hartmanni. The size ranges of these and other amoebae often overlap. Entamoeba hartmanni is incorrect because this amoeba measures less than 10 µm. Entamoeba histolytica is incorrect because this organism because between 10 - 20 µm. Balantidium coli is incorrect because this amoeba measures between 50 - 75 µm.
Charcot-Leyden crystals in stool may be associated with an immune response and are thought to be the breakdown products of:
Eosinophils Charcot-Leyden crystals in stool are thought to be created from damaged eosinophil byproducts. These crystals have a strong association, although they are rare, with parasitic infections or allergic reactions.
The properties of an antibody class are defined by the:
Fc end of molcule
Houseflies are a possible transport host for which of these categories of parasites?
Flagellates and amebae
Which genetic description will NOT contain Bart's hemoglobin at birth ?
Heterozygous alpha thalassemia-2
From the choices listed below, choose the most likely associated bacterial species represented in the image as pink, runny, mucoid colonies at 48 hours incubation on MacConkey (MAC).
Klebsiella pneumoniae
Nitric oxide is associated with the prevention of vaso-occlusion by decreasing cellular adherence to endothelium. Which amino acid is decreased in patients with sickle cell disease and is needed as a substrate to produce nitric oxide?
L-arginine
An 18-year-old female has a CBC performed as part of a routine physical exam. The following results were obtained, and the physician determines she is anemic. After reviewing her CBC results shown below, which of the following would be an appropriate description of the anemia? White blood cells (WBC)5.6 x 109/L 4.0-10.0 x 109/L Red blood cells (RBC) 3.7 x 1012/L 4.2-5.9 x 1012/L Hemoglobin9.9 g/dL 12-16 g/dL Hematocrit 28% 37-48% MCV75 fL 80-100 fL RDW-CV 14% 11.0-15.0%
Microcytic, homogenous cell population The MCV is indicative of microcytosis with MCV=<80fL. The RDW is within normal limits and indicative of a homogenous cell population. If the MCV were >100 fL, this would be indicative of macrocytosis. An RDW that was above reference range would be indicative of a heterogenous cell population.
All of the organisms are listed with a common site of recovery for that parasite, EXCEPT:
Plasmodium falciperum - ocular secretions
The cytochrome oxidase-positive bacterial species that is DNAse negative, ornithine decarboxylase positive, and is associated with gastroenteritis in children after the ingestion of contaminated water is most likely:
Plesiomonas shigelloides
Which of the following parasites is the causative agent of swamp fever?
Schistosoma mansoni egg
All of the following should be done when centrifuging specimens, EXCEPT?
Specimens with anticoagulant should sit for 20 minutes before centrifugation. Specimens with anticoagulants can be spun immediately. There is no reason to delay. Specimens without anticoagulants should sit at least 30 minutes prior to centrifugation to allow for complete clotting of the blood. Proper centrifugation procedure includes making sure all tubes are capped during centrifugation and letting the centrifuge stop completely by itself before opening it.
Contact dermatitis is mediated by:
T lymphocytes Contact dermatitis is an example of a cell-mediated (type IV) hypersensitivity reaction that involves macrophages and T lymphocytes. When an antigen comes in contact with the skin, the antigen is processed by cells in the epidermis and comes in contact with T lymphocytes. T lymphocytes recognize the antigen as foreign and circulate through the bloodstream back to the epidermis. There, they release cytokines that produce an inflammatory response, causing a characteristic rash in the skin called contact dermatitis.
A mother's serologic results are shown above. Her newborn types as group A Rh positive with a (1+) positive direct antiglobulin test (DAT). Which of the following investigative tests would be most useful to resolve the cause of the positive DAT and should be done FIRST?
Test newborn's plasma against group A1 red cells and group O antibody screen cells by IAT.
When is testing for weak D optional (not required)?
Testing for weak D on potential transfusion recipient samples. Testing for weak D on potential transfusion recipient samples is not required. However, some facilities will test for weak D on recipient samples. If the initial testing (immediate spin) is the only testing performed on the weak D individual, they would be considered Rh negative and would receive Rh negative blood. Since recipients who are weak D positive are considered Rh positive, they can receive either Rh positive or Rh negative blood. The AABB Standards requires testing for weak D on donor cells that do not directly agglutinate with anti-D reagents. Weak D testing is also performed cord blood from infants born to Rh negative moms and on Rh immune globulin workups.
Which statement about assays for the antigenic detection of both Clostridium difficile toxins A and B is TRUE?
The antigenic assays give rapid results.
Which of the following factors would least affect an orally administered drug's absorption and/or distribution in the body?
The position of the patient when the drug is taken (sitting vs. standing) The physical position of the patient when the drug is taken (sitting vs. standing) would not affect an orally administered drug's absorption and/or distribution in the body. Regional blood flow will affect drug distribution because the drug is transported in the blood. Reduced area blood flow can be seen in diabetics, and enhanced blood flow can be seen in tumors. Drug kinetics and dispositions change throughout life. In general, the metabolism of drugs is reduced in the elderly. In the diseased gut, an orally administered drug may not be absorbed as expected.
A negative glucose oxidase test and a positive test for reducing sugars in urine indicate:
The presence of a non-glucose reducing sugar such as galactose A negative glucose oxidase test and a positive test for reducing sugars in urine indicate the presence of a non-glucose reducing sugar such as galactose, fructose, glyceraldehyde, etc. This is the reason that certain patient populations such as infants require additional confirmatory sugar testing on their urine samples.
A chemical reaction that is utilized by many different analytical methods involves:
The reduction of NAD to NADH
What is a typical finding for determining the endpoint for the initial or iron-depletion phase of treatment for hereditary hemochromatosis (HH)?
The serum ferritin decreases to between 20 and 50 ng/mL
According to 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
Which marker is most useful for the detection of gestational trophoblastic disease?
hCG (human chorionic gonadotropin)
From the IgG molecule illustration, which region is the heavy chain?
heavy chain is bottom of Y (antibody) and light chain is top of Y
How should an ammonia specimen be transported to prevent alteration of the ammonia level in the blood plasma?
ice slurry The concentration of ammonia is unstable in a blood specimen left at room temperature or above. Therefore, the blood specimen should be placed into an ice slurry immediately after collection and tested as soon as possible. Ammonia is stable for several days if stored at -20° C. It is preferable to place the specimen into an ice slurry, rather than on top of a solid block of ice, so that the entire specimen is in contact with the ice. The specimen does not have to be protected from light.
In a normal CSF the protein concentration as compared to that in the plasma is generally:
less than 1%
What is the approximate percentage of individuals in the US who are heterozygous for HFE mutations for hereditary hemochromatosis?
10% to 12%
The normal Myeloid-to-erythroid ratio (M:E ratio) ranges from:
2:1 to 4:1
What is the increase in the risk for developing antibodies against red cell antigens (RBC alloimmunization) for patients who are characterized as chronically transfused patients?
30% or greater In chronically transfused patients, such as those with thalassemia, autoimmune hemolytic anemia, and sickle cell disease, the risk of developing antibodies against red cell antigens (RBC alloimmunization) increases by 30% or more.
What is the acceptable way to thaw Fresh Frozen Plasma?
37 degrees C water bath Fresh frozen plasma must be thawed at a maximum of 37oC in a water bath or similar FDA-approved equipment that has been validated and is temperature monitored. When using a water bath, the FFP should be wrapped in a plastic liner to prevent contamination of the administration ports. Any other non-approved method is not permitted.
Approximately how many doses are required to obtain a steady-state oscillation allowing for peak and trough levels to be evaluated?
5-7
A standard blood donation of 450-500 mL requires a minimum anticoagulant-preservative solution volume of:
63 mL The minimum volume of 63 mL of anticoagulant-preservative ensures that the donated blood product contains an appropriate anticoagulant-to-blood ratio. 57 mL of anticoagulant-preservative will not allow the donated blood unit to have enough anticoagulant to ensure a proper anticoagulant-to-blood ratio. 70 mL of anticoagulant-preservative is the maximum volume allowed to ensure proper anticoagulant-to-blood ratio. 82 mL of anticoagulant-preservative is too high and will result in an improper anticoagulant-to-blood ratio.
How long are healthy neutrophils expected to reside in the peripheral blood of an adult?
7-8 hours
A reference laboratory has 23,264 hours of total paid labor time. Of this amount, 2781 hours are nonproductive. If your employees work 40-hour work weeks each year, what is the total number of productive full-time equivalents (FTEs) needed to run the laboratory?
9.8 When calculating FTEs, you can divide the number of productive hours by 2080 (the total number of hours worked per year in a 40-hour workweek). In this case: Productive hours = Total hours - nonproductive hours = 20,483 hours PRODUCTIVE FTEs Calculation = 20,483hours paid for labor / 2080 hours per person = 9.8 FTEs Productive FTEs are different than regular FTEs because regular FTEs include non-productive hours, while productive FTEs do not.
What is the approximate volume of spinal fluid in an adult?
90-150 mL The approximate volume of CSF in an adult is 90-150 mL and about 10-60 mL in neonates. The CSF is produced in the choroid plexuses of the lumbar ventricles and the third and fourth ventricles. Adults produce about 20 mL of CSF per hour. The fluid is reabsorbed at the same rate it is produced by the arachnoid granulations/villae back into the blood capillaries.
The ketone component that is measured by the nitroprusside reaction is:
Acetoacetic acid The ketone component that is measured by the nitroprusside reaction is acetoacetic acid. A positive ketone result is demonstrated as a color change from purple to violet. The intensity of the violet color is proportional to the concentration of ketone bodies in the urine.
The characteristics of an acute phase protein include the following EXCEPT:
Acute phase proteins are synthesized slowly in response to tissue injury. 'Acute-phase proteins are synthesized slowly in response to tissue injury is the correct answer. The majority of acute-phase proteins are synthesized rapidly in response to tissue injury, e.g., inflammation, infection, malignant neoplasia, trauma, surgical procedures, or drug responses. Acute-phase proteins have different kinetics and various degrees of increase. The elevation is twofold to five-fold in certain disease states. A group of glycoproteins associated with the acute-phase response is collectively called acute-phase proteins of acute-phase reactants. More than 20 acute-phase proteins have a definable role in inflammation. An acute-phase response is a non-specific indicator of an inflammatory response. C-reactive protein (CRP) is an acute-phase protein. CRP is prominent among the acute-phase proteins because its changes show great sensitivity. Changes in CRP are independent of other laboratory tests, such as the erythrocyte sedimentation rate, and parallel the inflammatory process. CRP returns to lower undetectable levels as inflammation subsides. Laboratory measurement of an acute phase can be used to monitor the progress of therapy in inflammatory diseases. The acute-phase protein, CRP, is used clinically for monitoring infection, autoimmune disorders, and, more recently, healing after a myocardial infarction.
Which of the following enzymes is associated with conditions affecting skeletal muscles?
Aldolase
Which of the following blood tests is used to determine acute pancreatitis?
Amylase
On a quiet evening shift at a small hospital, you encounter a specimen with a positive antibody screen. As per your current laboratory protocol, you check for agglutination at the immediate spin phase of testing; and then again at the antihuman gloubulin (AHG) phase of 37°C. According to your laboratory guidelines, a single homozygous cell may be used to rule out an antibody. Based on the following 3-cell screen performed by tube, which of the following clinically significant antibodies are you unable to rule out?
Anti-Fya, -C, -Lub
Which antibody identified in prenatal specimens is never a cause of hemolytic disease of the fetus and newborn?
Anti-I Anti-I is a common autoantibody that can be found in virtually all sera. It is benign (not associated with in vivo red blood cell destruction). It is usually a weak, naturally occurring, saline-reactive IgM agglutinin. Rh antibodies are primarily IgG and Rh antigens are well developed early in fetal life. While the D antigen is the most immunogenic, c antigen is the next most likely Rh antigen to elicit an immune response, followed by E, C, and e. Rh antibodies formed by the Rh negative pregnant women coat the fetal red blood cells that carry the corresponding antigens. The coated fetal cells are removed from the fetal circulation (hemolytic disease of the fetus and newborn).
Identify the suspicious form (shown in the image) found in a stool specimen, measuring 50 µm.
Ascaris lumbricoides egg
To assess drug concentrations during the trough phase:
Blood should be drawnimmediately before the next dose is given. To assess drug concentrations during the trough phase, blood should be drawn immediately before the next dose is given. If the blood specimen was collected at one or two hours after the administration of an oral dose of the medication, the result would most likely reflect the peak level. If the blood specimen was collected half an hour before the dose is given, it will not be representing the real trough phase.
Which of the following genotypes is found with the highest frequency in the Caucasian population?
CDe/ce The genotype CDe/ce is found in 31% of the Caucasian population. The genotype CDe/cDe is found in 3% of the Caucasian population. The genotype cDE/ce is found in 10% of the Caucasian population. The genotype cDE/cE is found in less than 1% of the Caucasian population.
Different species of Neisseria can be differentiated from each other by:
Carbohydrate utilization Carbohydrate utilization tests are usually employed to identify various Neisseria sp. Rapid carbohydrate testing utilizes a heavy inoculum to determine the organism's ability to ferment glucose, maltose, lactose, sucrose, and fructose within 4 hours. All of the Neisseria species are oxidase positive. It does not differentiate between the various species. The majority of the Neisseria species are catalase positive. A superoxol test utilizing 30% hydrogen peroxide produces weak to strong reactions for the majority of the Neisseria species with only Neisseria elongata being negative. The majority of the Neisseria species are nitrate reduction negative. It is not a useful tool for differentiating the Neisseria species.
This micrograph is most consistent with the cell morphology of:
Corynebacterium diptheriae The morphology of the "diphtheroids" is sometimes described as resembling Chinese or Oriental letters (also described as palisades: cells lying in parallel rows). Although the cells of Bacillus species and Rothia species may on occasion vaguely arrange in an Oriental letter pattern, they are usually straight rods that lie more irregularly. The bacterial cells of Actinomyces species are slender filaments that branch.
Which of the following analytes would be increased due to delay in centrifugation?
Creatinine
The measurement of sodium and chloride in the sweat is the most useful test for the diagnosis of what condition/disease?
Cystic fibrosis
Which of the following phrases best describes a segmented neutrophil?
Cytoplasm appears pink-purple due to small specific granules. duh
Which of the following methods for long-term diabetic monitoring is recommended for patients with sickle cell anemia?
Fructosamine In sickle cell anemia, rapid hemoglobin turnover may be present. HbA1c and other glycosylated hemoglobin assays are not valid in rapid hemoglobin turnover and hemoglobinopathy conditions. Fructosamine measurements are more sensitive than HbA1c in monitoring long term diabetes in patients with such conditions. Fructosamine (also called glycosylated albumin) is formed by the nonenzymatic attachment of glucose to amino groups of proteins other than hemoglobin. Because albumin is the most abundant serum protein whose halflife is about 20 days, the concentration of glycosylated albumin reflects the consumption of glucose over a period of 2-3 weeks. This feature makes fructosamine the test of choice for monitoring diabetic control in patients with hemolytic anemias such as sickle cell anemia, thalassemia, and autoimmune hemolysis.
A key laboratory characteristic by which Mycobacterium bovis can be separated from Mycobacterium tuberculosis is:
Growth inhibition by thiopine-2-carboxylic acid hydrazide (T2H)
5% sheep blood agar will support the growth of most strains of the following organisms, EXCEPT:
Haemophilus spp. 5% sheep blood agar contains protoporphyrin IX, but not NAD (nicotinamide adenine dinucleotide) required by Haemophilus spp. for growth. All of the other organisms listed will grow on sheep blood agar. Haemophilus spp. requires chocolate agar to grow, as it provides hemin (X factor) and NAD (V factor).
The antibody mediator associated with a Type I Hypersensitivity Reaction is:
IgE A Type I Hypersensitivity Reaction is associated with IgE. The mast cell carries high-affinity receptors for the Fc portion of IgE. Allergen-specific IgE, occupying these receptors, induces mast cell degranulation immediately after allergens are encountered. IgM and IgG are not associated with a Type I Hypersensitivity Reaction but can be associated with immune complex Type III Hypersensitivity Reactions. IgG and possibly other immunoglobulins are not associated with a Type I Hypersensitivity Reaction but can be associated with cytotoxic, Type II Hypersensitivity Reactions. IgA is not associated with any Hypersensitivity Reaction. The functional characteristics of IgA are mucosal immunity and defense of external body surfaces.
Which test result will be normal in a patient with dysfibrinogenemia?
Immunologic fibrinogen level
How does hydroxyurea aid in the treatment of sickle cell disease?
Induces increased production of HbF. i knew this answer but google told me wrong Hydroxyurea induces increased production of HbF. Most sickle cell patients who have increased levels of HbF experience milder forms of the disease than do patients with normal or low levels of HbF. Therefore, the focus of molecular treatments for sickle cell disease is to increase fetal hemoglobin (HbF). Anti-inflammatory agents are given to serve as an analgesic in pain management for sickle cell patients. Nitric oxide treatment prevents sickle cells from clumping together. Clotrimazole is an over-the-counter antifungal medication. This drug prevents water loss from the red blood cells, which helps prevent the formation of sickle cells.
Which of the following tests on amniotic fluid would be included when assessing fetal lung maturity:
L/S ratio The correct answer choice here is L/S ratio. The lecithin/sphingomyelin ratio is determined by examining the amniotic fluid of a pregnant mother. Because amniotic fluid is continuously swallowed or inhaled and then replaced or exhaled in uterus the ratio can be measured to determine how much surfactant is in the fetal lungs. This ratio will help determine how well the infant's lungs will perform breathing at birth. Alpha-fetoprotein is used in assessing the potential for genetic disorders. Bilirubin is used in diagnosing the cause of jaundice and other liver problems.Fetal hemoglobin is not used to assess fetal lung maturity.
A beta-hemolytic gram-positive cocci, isolated from the CSF of an infant, grew on sheep blood agar under aerobic conditions and was resistant to a bacitracin disc. Which of the following tests should be performed for the presumptive identification of the organism?
Latex agglutination test
Which of the following species of Mycobacterium might be associated with contamination of the hot water system in large institutions such as hospitals?
M. xenopi
The appropriate media for the isolation of anaerobic bacteria from any source would normally include all of the following except:
MacConkey agar
Which of the following is the first step in the four steps of Koch's postulates?
Observe the same organism in all cases of a given disease
For blood gas analyzers, all of the following technologies are utilized for the measurement of pH EXCEPT:
Optical sensors. Optical sensors (or optodes) are used to measure fluorescence or phosphorescence of organic dyes in CO2, H+, and O2. Macroelectrochemical and microelectrochemical sensors (or electrodes) are used as sensing devices to measure pH, pO2, and pCO2. Ion-selective electrodes fall under the category of electrochemical sensors and are routinely used to measure pH in the blood.
What procedure utilizes leukapheresis to collect the buffy coat from whole blood?
Photopheresis Photopheresis utilizes leukapheresis to collect the buffy coat layer from whole blood. These cells are treated with 8-methoxypsoralen, exposed to ultraviolet A light and then reinfused into the patient. Photopheresis has been shown to be efficacious and has been approved by the Food and Drug Administration for the treatment of cutaneous T-cell lymphoma.
The colonies growing on blood agar, illustrated in the top image, are small, convex, entire, smooth, and light-yellow pigmented. Gram stain revealed short gram-positive bacilli arranged in loose clusters. Key to the identification is the positive lecithinase activity on egg yolk agar (lower image). Catalase and oxidase reactions were found to be positive and acid was produced from most carbohydrates. This is a soil organism occasionally causing nosocomial infections related to exposure to contaminated water. From these observations, select the presumptive identification of this isolate.
Oerskovia xanthineolytica Oerskovia xanthineolytica colonies on blood agar are entire, convex, smooth, yellow pigmented, and non-hemolytic. Observation of gram stains reveal coccoid to short rod-shaped gram-positive bacilli lying singly or in loose clusters. Distinctive is the production of lecithinase observed as areas of clearing around colonies growing on egg yolk agar as illustrated in the lower image. Cellumonas hominis is similar in colony and gram stain appearance to Oerskovia species. Colonies are also smooth, circular, convex, and white during initial growth, but may become yellow pigmented with maturity. Gram stains also reveal short gram-positive bacilli that are more slender than rod-shaped. The lecithinase reaction would be negative. Lactobacillus species colonies on sheep blood agar are gray-white, convex, smooth and non-discriminatory. Observation of light alpha hemolysis would help to make a presumptive identification. Microscopic observation of Gram stains reveal long, slender, gram-positive bacilli arranged in long chains rather than short bacilli in loose clusters. The lecithinase reaction would be negative. Rothia dentrocariosa colonies are pink-gray and often appear heaped and cerebriform, characteristically in a "spoke wheel" pattern, particularly in areas of confluent growth. Gram positive bacilli or cocco-bacilli are observed in diphtheroidal arrangements. The lecithinase reaction would be negative.
Which finding best distinguishes immune hemolytic anemia from other hemolytic anemias?
Positive DAT
When a patient has a bile duct obstruction, the bilirubin test portion of the reagent strip is:
Positive because conjugated bilirubin is present and is excreted by the kidneys. When a patient has a bile duct obstruction, the bilirubin test portion of the reagent strip is positive because conjugated bilirubin is present and is excreted by the kidneys. Unconjugated bilirubin, usually caused by red blood cell breakdown, is not able to be excreted from the kidneys, and will not cause a positive urine bilirubin result.
A liquid ion-exchange membrane electrode using the antibiotic valinomycin is MOST selective for:
Potassium
A flagellar stain would show peritrichous flagella for each of the following organisms except:
Pseudomonas aeruginosa
Which antinuclear antibody (ANA) pattern is seen in the image on the right, which represents the result of an ANA test viewed using fluorescent microscopy? Note: (a) points to the nuclei of interphase cells, the primary consideration for discerning the ANA pattern and (b) indicates a metaphase mitotic cell.
There is no discernable pattern In order for the ANA to be positive, there must be a clearly discernible pattern in the nuclei of the interphase cells. Observing the chromosomal area and cytoplasm of the metaphase cells may assist in the identification of the ANA pattern. The cells on this slide demonstrate weak staining in the nuclei of the interphase (nondividing) cells but no clear pattern. In addition, there is an absence of fluorescence in the chromatin region (center of the nucleus) in the metaphase (dividing) cells. In contrast, a homogeneous pattern would show uniform staining of the nuclei in the interphase cells and the presence of staining in the chromatin of the dividing cells. The centromere pattern is characterized by many discrete speckles in both the nuclei of interphase cells and the chromatin of dividing cells. In the nucleolar pattern, there is prominent staining of the nucleoli in the nuclei of the interphase cells and variable staining in the chromatin of the dividing cells.
Which one of the following statements concerning Vitamin D is correct?
Vitamin D acts as a hormone in calcium regulation. Vit C deficiency is scurvy Vit a aids in optic nerve Vit B6 is an also pyridoxal phosphate
All of the following laboratory tests are used to determine kidney function, EXCEPT?
amylase amylase tests for pancreatitis
Homogentisic acid in urine will cause urine to be which of the following colors?
brown/black homogentisic acid in urine is found in alkaptonuria (inherited amino acid disorder) so those people are lacking an enzyme that can break down that acid
A 1:100 dilution of a patient's peripheral blood was made, and a total of 136 platelets were counted in 5 squares of the RBC area of a Neubauer-ruled hemocytometer. What is the Platelet count? Note: The volume correction factor is 50 µL.
680 x 103/µL The general formula for calculating cellular elements on a Neubauer hemocytometer is as follows: Count = [(Dilution Factor) x (Total cell count in 5 RBC squares] x (Volume Correction Factor) Count = (100 x 136) x 50 = 680,000 or 680 x 103/ µL
The organism Acinetobacter baumannii is known to have caused which of the following outbreaks?
Afghanistan and Iraq U.S. soldiers outbreak
At a minimum, how frequently should an ocular micrometer be calibrated?
After major cleaning of the microscope or replacing objectives and as part of annual maintenance.
VDRL and RPR are examples of which of the following types of test methodologies?
Flocculation Flocculation tests are antigen-antibody tests in which the final product is a precipitin whose visible clumps can be seen either microscopically (VDRL) or macroscopically (RPR). Both VDRL and RPR are serologic screening tests for syphilis. ELISA is an enzyme-linked immunosorbent assay in which an antibody that contains an enzyme gives a visually discerning end product as the enzyme catalyzes a given reaction. Immunofluorescence testing uses immobilized antigens from the test sample and mono- or polyclonal antibodies that bind and fluoresce if antigens are present. Hemagglutination is the clumping of red blood cells.
You are collecting a blood specimen to be used for forensic (legal) alcohol testing. Which of the following must be done before you can start the specimen collection process?
Must inform the patient that the blood about to be collected is for alcohol testing.
Which of the following tests require a 72-hour stool (fecal) collection?
Quantitative fecal fat all of the other choices didn't make sense for a timed test
Which of the following would you find in a primary hyperparathyroidism case?
Elevated serum calcium and decreased serum phosphorus Primary hyperparathyroidism is a disorder of the parathyroid glands where overactive parathyroid glands secrete too much parathyroid hormone (PTH). This excess PTH triggers the release of too much calcium into the bloodstream. The bones may lose calcium, and too much calcium may be absorbed from food. The levels of calcium may increase in the urine, causing kidney stones. PTH also lowers blood phosphorus levels by increasing the excretion of phosphorus in the urine.
A patient has a history of repeated spontaneous abortion. Coagulation studies reveal an elevated APTT, normal PT, normal platelet function, and normal thrombin time. Schistocytes were seen on the peripheral blood smear. Which test should be performed to determine if the patient has lupus anticoagulant?
Platelet neutralization test
The cells in this image are from a bone marrow smear. Identify the cells present in this image:
osteoblast These cells are osteoblasts. An osteoblast is a large cell (up to 30µm) with a low N/C ratio and a small, round nucleus located eccentrically. Often these cells are said to have a comet or tadpole shape and the nucleus may be partially extruded. The blue cytoplasm has a bubbly appearance. Osteoblasts are responsible for the formation, calcification, and maintenance of bone.
A 31-year-old female with a known history of amebiasis, presented to her physician complaining of bloody diarrhea and fever. Previous patient history revealed that she lives in substandard conditions. Parasitic examination of the woman's stool revealed this suspicious form that measures 20 µm. The identification of this form is:
pseudoparasite
In the evaluation of a positive DAT result, all of the below techniques can be used to dissociate the antibody(ies) form the RBCs EXCEPT:
saline replacement
Based on the following choices, which one is the best way to identify microfilariae?
Arrangement of nuclei; presence or absence of a sheath i just guessed with 'sheath' Arrangement of nuclei; presence or absence of a sheath is correct because this is how microfilariae are identified. The microfilariae Wuchereria bancrofti and Onchocerca volvulus belong to the microfilariae and are identified on the basis of the arrangement of the nuclei and the presence or absence of a sheath. Presence or absence of peripheral chromatin; size and location of the karyosome is incorrect because this represents how amoebae are identified such as Entamoeba histolytica, Entamoeba coli, Entamoeba hartmanni, and Iodamoeba butschlii. All of these ameobae contain peripheral chromatin except Iodamoeba.Length of undulating membrane; presence of absence of cytostome is incorrect because this represents flagellates. The flagellates Trichomonas hominis and Trichomonas vaginalis are both only known to exist in the trophozoite form. Trichomonas hominis has a full length undulating membrane and a small cytostome. By contrast, Trichomonas vaginalis has an undulating membrane that only extends one-half the body length and lacks a cytostome.Arrangement of peripheral chromatin; appearance of karyosome is incorrect because this is used to identify amoebas.
The arrangement of erythrocytes on this peripheral blood smear can be associated with each of the following conditions EXCEPT: (picture is rouleaux)
Cold agglutinin disorders The correct response is cold agglutinin disorders. Erythrocyte agglutination (clumping) rather than rouleaux formation appears in these disorders when cold reactive antibodies, most commonly IgM, are circulating in the plasma. Microscopically, cold agglultinin disorders demonstrate large clumps of RBCs in contrast to the branching lines of RBCs seen in this image of rouleaux. The arrangement of the RBCs documented in the photograph is called rouleaux formation. Rouleaux resembles a stack of falling dominoes or coins. RBCs have a net negative charge on the surface of their plasma membranes. This negative charge helps to repel one RBC from another. Rouleaux formation is enhanced when positively charged plasma proteins are increased, particularly fibrinogen and gamma globulin. These positive proteins counteract the repulsive charge between RBCs. Multiple myeloma, chronic inflammatory disorders, and lymphoplasmacytic lymphoma are each responsible for increasing the concentration of these positively charged proteins leading to rouleaux.
What is a human infection caused by flukes called?
Distomiasis Distomiasis is an infection cause by flukes (trematodes). Infections are caused by ingestions of the metacercariae, the second larval stage, from raw or undercooked fish. Laboratory diagnosis of infection is by finding eggs in the feces or sputum. Elephantiasis is a condition caused by the presence of filarial roundworm, Wuchereria bancrofti. This worm lives in the lymphatics of the host, and elephantiasis develops after chronic infection. Accidental human infection from an animal is known as zoonosis. Some animal diseases can be transmitted to humans through bites, contact with a carcass, or an arthropod vector. Diseases include Rabies, Tularemia, and Lyme disease. Swimmer's itch is an allergic reaction caused by the presence of select schistosomes. The schistosomes do not invade and mature in humans; instead it penetrates the skin and dies. The body then develops an allergic reaction.
All of the following represent a 2 week temporary deferral from donating blood or blood products EXCEPT:
German measles (rubella) vaccine
Each of the following organisms may possess extended-spectrum beta-lactamase (ESBL) activity except:
Pseudomonas aeruginosa Pseudomonas aeruginosa is not tested for ESBL production. The organism is typically resistant to ampicillin, cefazolin, and other first and second generations cephalosporins. Escherichia coli, Klebsiella oxytoca, and Proteus mirabilis all can possess ESBL activity. These enzymes have the ability to inactivate penicillins, extended-spectrum cephalosporins and aztreonam. Klebsiella pneumoniae is also a very common organism that can display ESBL activity, and other genera including Salmonella species and Enterobacter species also have been identified with ESBL activity. ESBL enzymatic activity is confirmed in the lab by using clavulinic acid, which inhibits the enzyme activity. The organism is tested typically with cefotaxime and ceftazidime alone and then with each drug plus clavulinic acid. If the organism is resistant without clavulinic acid, but becomes sensitive with the addition of clavulinic acid, the resistance is due to the ESBL enzyme activity. Any identified ESBL organism should be reported resistant to cephalosporins, penicillins, and aztreonam, regardless of test results.
If detected in antibody screen testing, which of the following antibodies is NOT considered clinically significant in prenatal patients?
Anti-Leb Anti-Leb may be detected in antibody screen testing of prenatal patients; however, this antibody is considered clinically insignificant. It is not indicated in causing hemolytic disease of the fetus and newborn (HDFN). Although rarely seen, both anti-M and anti-N can potentially cause mild to moderate HDFN. The most common clinically significant antibodies noted in prenatal patients include the following: anti-Fya, anti-K, anti-D, anti-E, anti-e, anti-C, and anti-c. These IgG antibodies have been determined to cause moderate to severe HDFN.
A variety of additives are used in blood collection tubes. Which of the following additives prevents clotting by inhibiting thrombin and thromboplastin?
Lithium or sodium heparin Lithium/sodium heparin is an additive used to prevent clotting by inhibiting thrombin and thromboplastin. It is found in green and light green tubes.
With which of the following conditions is this suspicious form associated?
The egg pictured is that of Trichuris trichiura, also known as the whipworm, hence the condition name of whipworm infection. The presence of polar plugs on each end, along with the organism's size and oblong shape (football shape) aid in its identification, and make it readily distinguishable from the other helminth eggs. Eggs typically range in size from 50-55 µm by 25 µm.