Which of the following cardiovascular risk markers is a more sensitive version of a test that is used to assess inflammation?
hs-CRP is a more sensitive version of the C-reactive protein (CRP) test, a test that has been used for many years to assess inflammation in settings such as lupus, transplantation, infection, etc.
A patient suffering from Celiac disease and Crohn disease (both inflammatory conditions of the GI tract) is given a new oral medication that has a narrow therapeutic window. Which of the following would be true?
An oral medication is never effective for a patient that has these diseases. The drug must be given through IV.
Toxicity in this patient is not likely since most of the drug won't be absorbed.
Therapeutic drug monitoring (TDM) would be helpful to see how much drug has been absorbed.
Serum drug levels obtained 15 minutes after the oral dose should confirm the drug was absorbed.
TDM would be helpful to see how much drug has been absorbed. Blood collection for the TDM test should occur at least one hour after the administration of the oral drug. Measuring the serum level of the drug 15 minutes after the oral dose has been given is not sufficient time to allow for absorption
Celiac disease and Crohn's disease are both inflammatory conditions of the GI tract that can cause decreased absorption. Although an IV drug may be preferred, not all drugs are available as IV solutions; until low absorption is confirmed, an oral drug may be tried.
The patient may or may not have poor absorption, but toxicity could still occur regardless of absorption. For example, toxicity to the GI tract could ensue without the drug ever being absorbed.
What is the role of microalbuminuria testing?
Detect small urinary concentrations of albumin before there is irreparable renal damage. Microalbuminuria, low concentrations of urinary albumin, is measured to detect early renal impairment, at a stage where it is reversible with treatment.
The simplest form of a carbohydrate is a monosaccharide. Which of the following is a monosaccharide?
Glucose is a monosaccharide.
Glycogen is a polysaccharide, which is made up of multiple monosaccharides linked together.
Mucin is a glycoconjugate made up of polysaccharides and proteins.
Which two of the following biomarkers are not specific to cardiac muscle and may be elevated in patients with injury to muscle other than cardiac muscle?
Myoglobin and CK-MB are present in skeletal muscle and can be elevated in injury to these cells. Other causes of increased myoglobin and CK-MB levels include:
Severe injury to skeletal muscle
Extremely difficult breathing (increased use of chest muscles)
Chronic muscle disease
Troponin T and I tests are much more specific to cardiac muscle than myoglobin and CK-MB assays.
A left ventricular dysfunction resulting from aging, hypertension, atherosclerosis or muscle damage from an AMI or repeated AMIs.
Congestive heart failure
Which of the following is the EARLIEST biochemical marker of myocardial infarction?
Myoglobin is found in elevated levels when muscle tissue is damaged but it lacks specificity. It does, however, respond very rapidly after myocardial infarctions and rises within 2 hours, faster than CK, troponin, LD, or AST.
MOST of the carbon dioxide present in the blood is in what form?
Bicarbonate is an important component of our pH buffering system in the body and is the main source of carbon dioxide present in the body.
What condition is most likely when an oligoclonal band is seen in CSF electrophoresis without a corresponding serum peak?
Oligoclonal bands are found in the CSF of most patients with multiple sclerosis.
Patients with Cushing's syndrome would exhibit which of the following?
Decreased plasma 17-hydroxysteroid concentration
Decreased urinary 17-hydroxysteroid excretion
Serum cortisol concentrations greater than 15 mg/dl
Decreased cortisol secretion rate
Decreased ACTH levels
Serum cortisol concentrations greater than 15 mg/dl
Cushing's syndrome is a hormone disorder caused by high levels of cortisol in the blood. The normal range for cortisol levels is between 6 and 23 micrograms per deciliter (mcg/dL), which can be expressed as 0.006 to 0.023 mg/dL. In this case, a cortisol level of 15 mg/dL or 15,000 mcg/dL would be extremely elevated.
A 29-year old pregnant woman had an outpatient glucose tolerance test. The patient was given a 100-gm dose of glucose and the following values were obtained:
Fasting 110 mg/dL
1 hr. 148 mg/dL
2 hr. 175 mg/dL
3 hr. 143 mg/dL
What is the MOST likely interpretation of this glucose tolerance test?
Gestational diabetes mellitus (GDM)
Normal blood values for a 100-gram oral glucose tolerance test used to screen for gestational diabetes are as follows:
Fasting: less than 95 mg/dL
1 hour: less than 180 mg/dL
2 hour: less than 155 mg/dL
3 hour: less than 140 mg/dL
Which one of the following is a TRUE statement concerning alkaline phosphatase?
It is optimally active at pH 5
It is decreased in bone disorders involving the osteoblasts
It is increased in obstructive jaundice
The only correct answer is choice 3, as increased levels of alkaline phosphatase are found in patients suffering from obstructive jaundice. This enzyme is optimally active around a pH of 8.0-8.5 and in increased in bone disorders involving osteoblasts such as Paget's disease.
What is the major action of angiotensin II?
Angiotensin is an oligopeptide in the blood that causes vasoconstriction, increased blood pressure, and release of aldosterone from the adrenals.
Increases in blood ammonia levels would be expected in what condition?
End stage cirrhosis
Blood ammonia levels may be useful in monitoring treatment of hepatic coma.
Acute phase proteins generally fall into which category?
Acute phase proteins are a large group of glycoproteins found in the blood that are not related to immunoglobulins. Acute phase proteins are neither lipoproteins nor macroglobulins.
What substance is conjugated with the "indirect" bilirubin to form "direct" bilirubin?
Indirect bilirubin, also known as unconjugated bilirubin, is conjugated with two molecules of glucuronic acid to form direct, or conjugated bilirubin, which is water-soluble. Ascorbic acid, also known as vitamin C, uric acid, or salicylic acid do not conjugate with bilirubin.
The measurement of 17-ketosteroids in urine is performed to assess PRIMARILY which organ(s)?
Testes and adrenal cortex.
17-ketosteroids are metabolites of testosterone and adrenal steroid hormones. The majority of testosterone is produced in the testes and the adrenal cortex.
Lipemia in a serum sample is most likely caused by an increase in serum levels of what?
Lipemia is generally caused by an increase in VLDL (very low density lipoproteins), which are primarily composed of triglycerides.
Which of the following is used to treat heart failure and abnormal heart rhythms (arrhythmias)?
Which of the following is a bronchodilator used to treat a 39-year-old male asthmatic patient?
Which of the following is used to help prevent seizures?
Which of the following is an antidepressant medication?
Total iron-binding capacity measures the serum iron transporting capacity of what?
Transferrin is a glycoprotein that reversibly binds iron. Total iron binding capacity measures the amount of transferrin that is available to bind with iron in the serum.
60%-75% of the plasma cholesterol is transported by what?
Low density lipoproteins.
VLDL transports endogenous products, whereas chylomicrons transport exogenous (dietary) products. The majority of cholesterol is transported by LDL, and the rest is transported by HDL.
What are the primary reagent components used in the Jaffe reaction?
Saturated picric acid and sodium hydroxide are the main reagents used in the Jaffe reaction for creatinine determination. These chemical components usually cause the creatinine reagent to have a bright yellow color.
Bioavailability of an oral drug refers to what?
The fraction of the drug that is absorbed into systemic circulation.
The bioavailability of a drug is calculated by comparing the area under the plasma concentration-time curve of an equivalent dose of the intravenous form and the oral form of the drug. For oral drugs to be effective, bioavailability typically should be greater than 70%.
The following urine test results were obtained from a 6-month-old African American infant who experiences vomiting and diarrhea after milk ingestion and has failed to gain weight:
Urobilinogen: 0.1 EU/dL
These results suggest what clinically significant condition?
In patients with suspected primary hypothyroidism associated with Hashimoto's thyroiditis, one would expect the following laboratory test results:
T4 ___? TSH ___? TRH stimulation ___?
decreased, increased, increased
In Hashimoto's, antibodies react against proteins in the thyroid gland, causing gradual destruction of the gland itself, and making the gland unable to produce the thyroid hormones the body needs. Therefore the T4 is decreased, but the TSH is increased since the pituitary gland is attempting to stimulate the failing thyroid gland. The TRH stimulation is increased since the pituitary gland is working and is able to produce elevated levels of TSH upon TRH stimulation.
A 70-year-old type 2 diabetic patient is comatose and in the emergency department. Stat blood glucose and serum ketones are ordered.
Blood Glucose 650 mg/dL
Serum Ketones Negative
What is the best conclusion?
The blood glucose value is critical; negative ketones is consistent with type 2 diabetes. An elderly type 2 diabetic patient is at risk for hyperosmolar nonketotic coma and osmolality should be measured.
A positive RPR test and a negative FTA-ABS test is most likely the result of:
False positive reaction
False positive reaction.
The FTA-ABS is used to confirm that a positive non-treponemal test like RPR is not the result of a biological false positive, which occur in about 1 to 10 percent of the population.
When performing an antibody panel, which one of the following antigens will be rendered inactive by enzyme treatment?
Duffy antigens are rendered inactive by enzyme treatments since the enzyme will remove the sialic acid from the RBC membrane. This process destroys: M, N, S, s, and Duffy antigens. The process enhances the reactions for Rh, Kidd, Lewis, I, and P antigens.
A routine laboratory workup is ordered for an outpatient. The patient's lipid results are as follows:
Total cholesterol = 295 mg/dL
HDL = 30 mg/dL
Triglycerides = 200 mg/dL
What is the LDL cholesterol level for this patient?
LDL cholesterol = Total cholesterol - (HDL + (Trig / 5))
In this case, the calculation for LDL would be:
LDL cholesterol = 295 mg/dL - (30 mg/dL + (200 mg/dL / 5))
LDL cholesterol = 295 mg/dL - 70 mg/dL = 225 mg/dL
The erythrocyte inclusions which are thin, red-purple staining strands usually found in figure-eight shapes are called what?
Cabot rings are rare erythrocyte inclusions which are thought to be made of mitotic spindle remnants. The inclusions have a characteristic figure eight shape. This inclusion has been found in various conditions; including severe dyserythropoiesis.
What is the purpose of C3a, C4a, C5a, the split-products, of the complement cascade?
The purpose of C3a, C4a, C5a, the split-products, of the complement cascade is to cause increased vascular permeability, contraction of smooth muscle, and release of histamine from basophils. C3a, C4a and C5a, bioactive fragments of the complement components C3, C4 and C5, respectively play a key role in mediation of immunologically provoked inflammatory responses. C4a production results from classical pathway activation while, C3a and C5a are produced by the activation of the classical pathway and/or the alternative pathway.
Which EBV markers would be MOST likely positive for an individual who had infectious mononucleosis 9 years ago?
Anti-VCA (IgG) and anti-EBNA
What is the maximum interval during which a recipient sample may be used for crossmatching if the patient has been recently transfused, has been pregnant within the past 3 months, or if relevant medical/transfusion history is unknown?
What condition is indicated by the following blood gas results: Bicarbonate = 32 mmol/L (Normal = 22 - 26 mmol/L); pCO2 = 65 mm Hg (Normal = 35 - 45 mmHg); pH = 7.28 (normal = 7.35 - 7.45)
Uncompensated respiratory acidosis
Mrs. Jones, a diabetic, is admitted to the hospital on November 25th. It appears that she has had an AMI but did not feel the severe chest pain because of diabetic neuropathy. She has not felt well since November 20th and her physician believes she possibly had an AMI on November 20th.
Assuming that the infarct was uncomplicated, which of the following cardiac biomarkers would most likely still be elevated and would assist in an AMI diagnosis?
Cardiac troponin I (cTnI) or cardiac troponin T (cTnT)
cTnI and cTnT remain elevated after an AMI for 10-14 days. Myoglobin returns to normal range in 24-36 hours and CK-MB is back to normal range in 48-72 hours.
Which of the following bacterial species characteristically produces positive reaction in both bile esculin and 6.5% NaCl broth?
Of the bacterial species listed in this exercise, only Enterococcus faecalis hydrolyzes esculin (black color in the medium) and can grow in culture medium containing 6.5% sodium chloride (turbid broth and yellow color). Staphylococcus aureus can grow in 6.5% sodium chloride, but does not hydrolyze esculin. Both Streptococcus bovis and Listeria monocytogenes hydrolyze esculin, but neither will grow in a 6.5% sodium chloride.
What is the site used most frequently in the adult patient when performing a bone marrow biopsy?
Iliac crest (posterior)
What is the proper storage temperature for fresh frozen plasma?
FFP must be separated from RBCs and frozen solid at less than or equal to -18 degrees Celsius within 8 hours of collection.
Which method remains the "gold standard" for ANA detection?
Slide-based ANA tests using HEp-2 or HEp-2000® cells are the gold standard. Dozens of different antibodies can be detected using slide-based assays. Solid phase assays such as bead and ELISA assays lack sensitivity, resulting in an unacceptable number of false negative results.
What bacterial species is most likely associated the infectious disease syndrome "Foot rot" or "pitted karyolysis"?
What bacterial species is most likely associated the infectious disease syndrome "Subcutaneous mycetoma"?
What bacterial species is most likely associated the infectious disease syndrome "Food borne enteritis"?
What bacterial species is most likely associated the infectious disease syndrome "Alkaline crusted cystitis"?
What has happened in a titer, if tubes #5-7 show a stronger reaction than tubes #1-4?
By definition, prozone is a phenomena occur in immunological reactions when the concentrations of antibody are so high that the optimum concentration for maximal reaction with antigen is exceeded. Immunological phenomena in the prozone region may show partial or total inhibition. Since this is the case in the question, there is a partial inhibition in tubes 1-4 where the antibody is in higher concentrations causing the prozone effect. In tubes 5-7, the antibody concentration is less, therefore there is no prozone effect and a stronger reaction will then occur in these tubes.
Which genotypes cause beta thalassemia minor?
B+/B and B0/B
B+/B denotes beta thalassemia minor exhibiting partial deletion of one gene locus and B0/B denotes beta thalassemia minor exhibiting total deletion of one gene locus.
B/B denotes a normal beta chain genetic component.
(B0/B0 represents beta thalassemia major, exhibiting total deletion of both gene loci.)
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
Most common methods for measuring bilirubin are based on the reaction of bilirubin with what?
Diazo reagent (diazotized sulfanilic acid)
What is the name of the rapid test often used to differentiate S. pneumoniae from viridans streptococci, in which a drop of 10% deoxycholate is placed on an area of growth?
The bacterial cells of S. pneumoniae are bile soluble, as shown by the disappearance of the colonies in the area where a drop of 10% deoxycholate had been added to the surface of the agar. The colonies of viridans streptococci would remain intact and clearly visible.
What causes polyacrylamide gels to have greater resolution of proteins than agarose gels?
Polyacrylamide gels are composed of layers of polyacrylamides and each layer can be created with a different pore size. These varying pore sizes result in more separated bands after electrophoresis.
What disease or disorder that would most likely cause a positive result for ketones on the urine reagent strip?
What disease or disorder that would most likely cause a positive result for blood on the urine reagent strip?
Renal calculi, glomerular damage, UTI
What disease or disorder that would most likely cause a positive result for bilirubin on the urine reagent strip?
What disease or disorder that would most likely cause a positive result for nitrites on the urine reagent strip?
A key laboratory characteristic by which Mycobacterium bovis can be separated from Mycobacterium tuberculosis is:
Growth inhibition by thiopine-2-carboxylic acid hydrazide (T2H)
A patient is admitted to the hospital with acute chest pain, but which of the following enzymes will be elevated FIRST if the patient had an MI?
CK, especially the isoenzyme CK-MB, rise typically within 4-6 hours after a myocardial infarction and stay elevated for days, with a peak at the 24-hour mark post-MI. The FASTEST cardiac enzyme to rise after a mycardial infarction is actually troponin, which can rise within 2 hours of a MI. LD, AST, and ALT can also be elevated after a myocardial infarction, but levels are slower to rise.
Chryseobacterium is the new genus name for the bacterium formerly called Flavobacterium meningosepticum, an important agent of neonatal mentingitis. What is the biochemical characteristic that is unique for the Family Flavobacteriaceae among the nonfermenters?
What anomaly is characterized by the presence of large, fused granules in the cytoplasm of white blood cells and some tissue cells.
What 3 tests may be used to differentiate Listeria monocytogenes and Erysipelothrix rhusiopathiae?
(1) motility agar (2) esculin hydrolysis and (3) VP (L. monocytogenes is positive for all 3)