medialab recall -- questions you've missed
How many microns are equivalent to one ocular micrometer unit at 100X given the following information? ocular micrometer units: 50 stage micrometer units: .05 10.8 micron 1.0 micron 0.1 micron 0.01 micron
1.0 micron (number of stage micrometer units X 1000) / (number of ocular micrometer units) Inserting the values given in this question: .05 X 1000 / 50 = 1.0 µm Therefore, each ocular unit = 1.0 µm
How many standard deviations (SD) above and below the mean is accepted as being an appropriate control limit range on a control chart utilizing the Westgard rules: 1 SD 2 SD 3 SD 4 SD
3 SD - 12S and 12.5S is okay in the clinical laboratory, but 13S indicates erroneous behavior of the test system.
A platelet component prepared from a unit of whole blood (random donor platelet) must contain at least how many platelets? 3.8 x 10^10 platelets/unit 4.0 x 10^10 platelets/unit 4.5 x 10^10 platelets/unit 5.5 x 10^10 platelets/unit
5.5 x 10^10 platelets/unit Random donor platelet concentrates typically contains between 5.5 and 8.5 X 10^10 platelets suspended in about 50 mL of plasma. This is approximately 70% of the platelets which were present in the original unit of whole blood collected by the donor.
The most common forms of hereditary sideroblastic anemia (SA) are due to which of the following? A defective X-linked recessive gene. A defective Y-linked dominant gene. An amino acid substitution on the beta chain. An under production of alpha chains.
A defective X-linked recessive gene. Hemoglobinopathies are, in many cases, due to an amino acid substitution. Underproduction of alpha chains occurs in a-thalassemia.
Cooley's anemia is another name for which form of beta thalassemia?
Beta thalassemia major
Increases in blood ammonia levels would be expected in which of the following conditions: Diabetes Obstructive jaundice End stage cirrhosis Myocardial infarction
End stage cirrhosis Ammonia rises in blood when the liver cannot conver ammonia to urea -- such as in end-stage cirrhosis. Ammonia levels can monitor hepatic coma treatment as well.
Illustrated in the upper image is an 8-day-old old green black colony growing on the surface of Sabouraud Dextrose Brain Heart Infusion (SABHI) agar, obtained from a superficial skin lesion characteristic of chromomycosis. The black pigment extends to the reverse side of the colony. The identification can be made by observing the characteristic fruiting body as illustrated in the lower image. What is the most likely identification of this fungi? Exophiala jeanselmei Cladophialophora carrionii Fonsecaea pedrosoi Phialophora verrucosa
Exophiala jeanselmei Exophiala jeanselmei exhibits slow growth and the black pigment on the surface that extends to the reverse of the colony is distinctive for chromomycosis. The dark-staining septate hyphae containing a distinctive conidiophore with a pointed terminal end, giving rise to clusters of elongated pigmented conidia is the exophiala type sporulation characteristic of Exophiala jeanselmei.
Which of the following terms is used to describe the appearance of rod-shaped bacteria? Budding Septate Filamentous Lancet
Filamentous Nocardia are filamentous and they are a GNR. Other terms for bacilli are diphtheroid, pleomorphic, beaded, branched, bipolar, spiral, and fusiform. Budding is associated with yeast (cocci-like). Septate refers to mycological hyphae. Lancet-shaped refers to GPDC seen with S. pneumoniae.
What causes chromoblastomycosis?
Fonsecaea pedrosoi - Conidiophores with denticles (small projections) that bear a SINGLE conidia. Cladophialophora carrionii - Dark-staining elliptical conidia (lemon-shaped) are arranged in long branching chains, each seperated by a "dysjunctor".
Of the following, what is the recommended routine testing to be performed on a newborn of a group B Rh positive female? ABO and Rh testing would routinely be performed in this scenario. ABO, Rh and DAT would routinely be performed in this scenario. ABO, Rh and antibody screening would routinely be performed in this scenario. ABO/Rh, DAT and/or antibody screening are NOT routinely performed in this scenario.
ABO/Rh, DAT and/or antibody screening are NOT routinely performed in this scenario. It is NOT acceptable practice to test newborns of Rh positive women with blood types other than O because ABO HDFN is caused by anti-A, anti-B, and/or anti-A,B from a *group O mother* who gives birth to a *non-O newborn*.
What Gram positive bacilli is positive for urease (of the following)? Lactobacillus species Actinomyces naeslundii Erysipelothrix species Cutibacterium (Propionibacterium) acnes
Actinomyces naeslundii
The serum from a patient of African-American descent is reactive with all screening and panel cells. Which antibody directed to a high incidence antigen is most likely to be present? Anti-Lub Anti-Jk3 Anti-U Anti-Ku
Anti-U The U antigen is located on glycophorin B, a glycoprotein that carries the S, s, and U antigens in the MNS blood group system. Individuals who are U-negative are also S-s- and are of black descent. This phenotype is never found in the white population. The U antigen is present in more than 99% of the population. Anti-Lub is rarely seen because of the high prevalence of the antigen. The presence of anti-Lub is not associated with a specific ethnicity. Individuals who are Jk(a-b-) can make anti-Jk3. The Jk(a-b-) phenotype is most commonly seen in individuals of Polynesian, Filipino, or Chinese descent. Anti-Ku may be found in immunized individuals who have the Kell null (K0) phenotype. The K0 phenotype is not associated with a specific ethnicity.
In most cases of Fanconi anemia, which of the following types of anemia develops? Aplastic Microcytic Hemolytic Drug-induced
Aplastic Fanconi's is a hypoproliferative disorder and 90% of diagnosed persons eventually develop *aplastic anemia*. Pancytopenia is noted around age 5 typically; this disorder is congenital + autosomal recessive. This anemia is NOT microcytic and, in fact, many of these cases present as *macrocytic* or *normocytic*, so microcytic anemia is incorrect.
Which Gram negative organism can produce "gliding motility" on agar plates and is a primary cause of juvenile periodontitis? Eikenella corrodens Aggregatibacter actinomycetemcomitans Capnocytophaga ochracea Fusobacterium nucleatum
Capnocytophaga ochracea Capnocytophaga bacteria generally inhabit the oropharyngeal microbiota -- this species is found in the normal flora of human mouths. Production of substances that inhibit neutrophilic function, proteolytic enzymes + its' unique gliding motility allows it to inhabit the deeper tissues of the oral cavity. Aggregatibacter actinomycetemcomitans do not exhibit gliding motility. Eikenella corrodens is normal oral flora, non-motile, and not incriminated it dental disease. It produces pitting and it is found in human bite infections.
Daily activities by microbiology personnel should be performed to ensure patients receive the best care. All of the following activities should be performed daily EXCEPT? Compare Gram stain reports with what grows in culture to ensure all organisms are recovered Check antimicrobial susceptibility reports to ensure correct drug/organism profiles Check susceptibility reports for multiple-drug-resistant organisms Check to ensure autoverification of results is working correctly
Check to ensure autoverification of results is working correctly This is performed YEARLY. This refers to the release of results by an LIS system *WITHOUT human intervention.*
The arrangement "rouleaux" on a peripheral smear can be associated with each of the following conditions EXCEPT: Multiple myeloma Cold agglutinin disorders Chronic inflammatory disorders Lymphoplasmacytic lymphoma
Cold agglutinin disorders - Clumping occurs with cold reactive antibodies (IgM); these are large clumps rather than branching lines of rouleaux (coin stacking). Rouleaux formation is enhanced when positively charged plasma proteins are increased, particularly fibrinogen and gamma globulin.
Each of the following parasites, whose common names are listed, is associated with intestinal infections, EXCEPT: Whipworm Dwarf tapeworm Malayan filarial worm Pinworm
Malayan filarial worm Brugia malayi, commonly known as the malayan filarial worm, is a tissue roundworm residing in the lymphatics vessels. It is not associated with intestinal infections. Trichuris trichura, commonly known as whipworm is an intestinal nematode. Enterobius vermicularis, commonly known as pinworm is also an intestinal nematode. The dwarf tapeworm, Hymenolepis nana, is an intestinal cestode.
Human dog bite infections may be caused by each of the following bacterial species:
Pasteurella multocida Capnocytophaga cynodegmi Neisseria weaveri The organism Capnocytophaga ochracea is in the oropharynx microbiota of a human -- this would not be involved in a dog bite infection.
Which of the following parasites is the causative agent of swamp fever? Schistosoma mansoni egg Strongyloides stercoralis larva Enterobius vermicularis scolex Taenia saginata scolex
Schistosoma mansoni egg Schistosoma mansoni is the causative agent of swamp fever. The eggs of this organism may be readily identified by their large size and characteristic shape, particularly the presence of a lateral spine located near the posterior end (as seen below). The name schistosome was developed based on the appearance of the adult male that has a genital groove that serves as the receptacle for the female during copulation. S. stercoralis --> threadworm E. vermicularis --> pinworm T. saginata --> beef tapeworm
The qualitative differences between A1 and A2 phenotypes includes all of the following EXCEPT: The formation of anti-A1 in A subgroups. The amount of transferase enzymes. The length of the precursor oligosaccharide chains. The lack of agglutination of patient red cells with anti-A reagent.
The lack of agglutination of patient red cells with anti-A reagent. - Think anti-A1 production; Dolichos biflorus lectin differentiates between the two phenotypes. *A1 patient cells agglutinates with this lectin but NOT with A2 patient cells.*
According to the American Diabetes Association recommendations, which of the following statements is TRUE with regards to the following findings? Fasting glucose = 130 mg/dL 2-hour post prandial glucose = 210 mg/dL The patient may be diagnosed as having diabetes mellitus The patient is diagnosed as having impaired glucose tolerance The patient is diagnosed as having diabetes insipidus The patient is normal
The patient may be diagnosed as having diabetes mellitus In diabetes mellitus, FPG = >126 mg/dL 2h postprandial glucose = >200 mg/dL
Schistosoma mansoni
blood fluke "looks like a chat bubble"
Which cardiac biomarker is a regulator of myocyte contraction? myoglobin cTnT CK-MB isoforms of CK-MB
cTnT --> troponin
Proper storage from granulocyte concentrates is: 1 - 6 degrees Celsius,12 hours -20 degrees Celsius, 48 hours 1 - 6 degrees Celsius, 24 hours 20 - 24 degrees Celsius, 24 hours
20 - 24 degrees Celsius, 24 hours
Which of the following is NOT a cause of death in patients with hereditary hemochromatosis (HH)? Autoimmune disease Hepatocellular carcinoma Cirrhosis Cardiomyopathy
Autoimmune disease Hemochromatosis has no correlation with autoimmune diseases. Autoimmune diseases are due to the production of auto-antibodies. Iron accumulation is damaging to the liver, pituitary, and circulatory system. Death is due to iron overload with organ damage and cirrhosis. The liver is commonly involved and hepatomegaly is usually present. Hepatocellular carcinoma and cirrhosis of the liver are two common causes of death due to excess iron in the liver. Cardiomyopathy is a cause of death which can be due to excess iron present in the heart.
Important applications of polymerase chain reaction (PCR) include the following with the general exception of: Search for mutations with large deletions Amplification of DNA Identification of a target sequence Synthesis of an anti-sense probe
Search for mutations with large deletions This is a weakness of PCR. *Generally, ONLYY short sequences can be amplified. An anti-sense probe synthesis is crucial in PCR as an antisense RNA necessary for nucleic acid extension.
If a commercial lyophilized reagent is diluted using slightly more distilled water than indicated, what type of error will occur? Random error Systematic error Precision error Reagent error
Systematic error The reagent is used CONSISTENTLY in the test system, so an error in adding additional distilled water to a reagent would cause each sample to have an abnormal high or low result is an example of a systematic error. Systematic errors typically cause a trend or shift of results above or below the quality control mean.