The steps in the PCR process are:
1. Denaturation (Turning double stranded DNA into single strands.)
2. Annealing/Hybrization (Attachment of primers to the single DNA strands.)
3. Extension (Creating the complementary strand to produce new double stranded DNA.)
What is the first step of the PCR reaction?
Enterobius vermicularis infection occurs through swallowing ova. Pinworm infections including those caused by Enterobius vermicularis, usually occur due to a fecal-oral route of transmission. According to the CDC, "Eggs are deposited on perianal folds. Self-infection occurs by transferring infective eggs to the mouth with hands that have scratched the perianal area. Person-to-person transmission can also occur through handling of contaminated clothes or bed linens. Enterobiasis may also be acquired through surfaces in the environment that are contaminated with pinworm eggs (e.g. , curtains, carpeting). Some small number of eggs may become airborne and inhaled. These would be swallowed and follow the same development as ingested eggs. Following ingestion of infective eggs, the larvae hatch in the small intestine and the adults establish themselves in the colon. The time interval from ingestion of infective eggs to oviposition by the adult females is about one month. The life span of the adults is about two months. Gravid females migrate nocturnally outside the anus and oviposit while crawling on the skin of the perianal area. The larvae contained inside the eggs develop (the eggs become infective) in 4 to 6 hours under optimal conditions . Retroinfection, or the migration of newly hatched larvae from the anal skin back into the rectum, may occur but the frequency with which this happens is unknown."
Enterobius vermicularis infection occurs through:
Myoglobin release is strongly associated with muscle damage; therfore, it would most closely match a diagnosis of massive muscle trauma in this question.
Myoglobinuria is MOST likely to be noted in urine specimens from patients with which of the following disorders?
PCT usually rises within 3-6 hours of infection. CRP also increases rapidly following infection, but is not as specific for infection as PCT. A rise in CRP could also occur with SIRS. Lactic acid is usually used to detect and monitor impaired circulation and tissue oxygenation in critically ill patients.
Chemistry
Of the three laboratory tests that are listed, which has proven to be most effective for early differentiation of systemic inflammatory response syndrome (SIRS) from sepsis due to its increase following infection and higher specificity?
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.
Blood Bank
What other component(s) can be shipped together with Fresh Frozen Plasma (FFP)?
In the laboratory, surfaces must be disinfected for blood spills. What is the most common disinfectant used?
HCG levels rise rapidly during the first trimester, then the levels start to decline around week 16. The hCG levels slowly decrease and can level off during the remainder of the pregnancy.
The following BEST describes serum hCG levels during pregnancy:
Serum calcitonin is normally produced by the C cells of the thyroid. It functions to reduce serum calcium by inhibiting release of calcium from bone. It is a peptide with a molecular weight of 3400, and has a half life of approximately 12 minutes. It is characteristically elevated in medullary carcinoma of the thyroid. Since medullary carcinoma often occurs as an autosomal disorder, family members of patients with this condition should be screened for serum calcitonin.
Serum calcitonin is typically elevated in which of the following conditions:
Which of the following is a selective media recommended for the isolation of Clostridium difficile?
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.
The Red cell Distribution Width (RDW) in alpha thalassemia is
Streptococcus pyogenes is the correct answer. Streptococcus pneumoniae is alpha-hemolytic which demonstrate a green area of partial hemolysis around the colonies. Staphylococcus aureus will produce complete hemolysis but is catalase positive. Streptococcus agalactiae is beta-hemolytic but only produces a partial clearing of the red blood cells in sheep blood agar.
Complete hemolysis of sheep blood agar as demonstrated by the image below would be seen in which of the following catalase-negative isolates?
The Western Blot Assay is used as a confirmatory test for which of the following:
The intended response is Vitamin B12 and folate deficiencies. Each of these conditions lead to a megaloblastic production of the red blood cells in the bone marrow. Since vitamin B12 and folate are needed in order to produce a synchronous development of the nucleus with the cytoplasm in hematologic cells, oval-macrocytosis often occurs if these nutrients are not in adequate supply within the body. This can also affect neutrophils, allowing for the characteristic hypersegmented nucleus.
The photographic field contains several oval-macrocytes and a hypersegmented neutrophil with greater than 5 nuclear segments. Oval macrocytes are most commonly associated with pernicious anemia and malabsorption syndromes leading to vitamin B12 and folic acid deficiencies.
Clinical information relating to chronic infection, aplastic anemia, and other hematologic maligancies provide the context for the presence of the oval macrocyte.
Macrocytic erythrocytes and hypersegmented neutrophils are not present in thalassemias or in Pelger-Huet anomaly (hyposegmented neutrophils).
Conditions suggested by the macrocytes and the neutrophil in the photograph to the right include which of the following?
Transfusion of red cells of any ABO type other than O to a group O patient is of course likely to cause a hemolytic transfusion reaction.
Which of the following types of packed RBCs could be transfused to a group O patient:
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