MLT Chemistry/Special Chemistry Quiz Review

The presence of which of the following isoenzymes indicates acute myocardial damage? A) CKMM B) CKMB C) CKBB D) none

B) CKMB The 3 CK isoenzymes are CK1 or CKBB, CK2 or CKMB, and CK3 or CKMM. CKMB is primarily located in myocardial tissue. Damage to the myocardium will cause an elevation of CKMB level.

Cocaine is metabolized to: A) carbamazepine B) codeine C) hydrocodone D) benzoylecgonine

D) benzoylecgonine The primary metabolite of cocaine is benzoylecgonine, which is produced by the liver and eliminated in the urine. Benzoylecgonine is detected in drugs of abuse screens for cocaine.

In the liver, bilirubin is converted to: A)urobilinogen B)urobilin C)bilirubin-albumin complex D) bilirubin diglucuronide

D) bilirubin diglucuronide Hemoglobin released from aged or damaged red blood cells is converted to bile pigment bilirubin by a complex series of reactions. The cells of the reticuloendothelial system, especially in the spleen, liver, and bone marrow, first phagocytize the red cells and then convert the released hemoglobin into bilirubin. The bilirubin is eventually transported from the sxtrahepatic sources as bilirubin-albumin complex into the hepatic sinusoids and then to liver cells. The protein is separated from the complex, and bilirubin is converted into bilirubin diglucuronide.

The identification of Bence Jones protein is best accomplished by: A) a sulfosalicylic acid test B) urine reagent strips C) Immunofixation D) electrophoresis

C) Immunofixation Monoclonal free kappa or lambda light chains.

An asparatate aminotransferase (AST) test is analyzed on a patient sample and the result is below the analytical measurement range (AMR), which for the instrument in this scenario is 4.0-900 U/L. The laboratory director has stated that quantitating AST values that are less than 4 U/L are not clinically useful. How should this patient's results be reported? A) <4.0 U/L B) 4.0 U/L C) unable to report; exceeeds the measurement limit of analyzer D) report the number the instrument provides

A) <4.0 U/L In this case, the AMR is exceeded on the low end. The policy that is dictated by the laboratory director is not attempt to quantitate an exact value if it is less than the lower end of the AMR of 4. The value should be reported as <4.0 U/L. The instrument has reported that the value is below 4.0. Therefore, reporting the result as 4.0 would be incorrect. It is also not correct to state that the value exceeds the measurement limit of the analyzer. This could be interpreted as exceeding the high end of the measurement range, a false assumption that could lead to incorrect patient treatment.

In the Jendrassik-Grof method for the determination of serum bilirubin concentration, quantitation is obtained by measuring the green color of: A)azobilirubin B) bilirubin glucuronide C)urobilin D)urobilinogen

A)azobilirubin In the Jendrassik-Grof method for bilirubin measurement, the addition of caffeine plus diazotized sulfanilic acid and the serum produces azobilirubin. Ascorbic acid, alkaline tartrate and dilute HCl are added to the reaction mixture. The blue-green azobilirubin is measured. Bilirubin glucuronide, urobilin, and urobilinogen are intermediaries in bilirubin metabolism. They are not measured by this method.

How would hemolysis affect a plasma ammonia level? A) increase B) decrease C) no effect

A)increase Erythrocytes contain 2-3 times more ammonia than plasma. If a plasma specimen is hemolyzed, the plasma ammonia level may be slightly increased.

Which CSF results are most consistent with bacterial meningitis? CSF sample Glucose Protein Lactate A. 20mg/dL 50mg/dL increased B. 75mg/dL 20mg/dL increased C 20mg/dL 45mg/dL decreased D 75mg/dL 120mg/dL decreased A. sample A B. sample B C. sample C D. sample D

A. sample A Normal CSF glucose is approximately 60% of plasma glucose. Glucose is decreased in bacterial meningitis, and lactate is produced. Normal protein in CSF is 15-45 mg/dL. Protein is slightly elevated in bacterial meningitis.

A drug has a half-life of 6 hours. If a dose is given every 6 hours, a steady-state drug level would usually be achieved in: A) 3-5 hours B) 10-12 hours C) 24-42 hours D) 48-50 hours

C) 24-42 hours A steady state therapeutic drug level is achieved between 4 and 7 doses. May variables affect when steady state is achieved.

The glycated hemoglobin value represents the integrated values of glucose concentration during the preceding: A)1-3 weeks B)4-5 weeks C) 6-12 weeks D)16-20 weeks

C) 6-12 weeks Hemoglobin A1C, also called glycated hemoglobin, is used to determine how well diabetes is being controlled. HbA1C provides an average of glucose values over a 6-12 week period. For people without diabetes, the normal range for HbA1C is between 4%-6%. The goal for people with diabetes is an HbA1C of <7%. The higher the HbA1C, the higher the risk of developing complications related to diabetes.

When separating serum proteins by cellulose acetate electrophoresis, using Veronal buffer at pH 8.6, beta globulin migrates: A) faster than albumin B) slower than gamma globulin C) faster than gamma globulin D) faster than alpha-2 globulin

C) faster than gamma globulin Protein electrophoresis migration.

Total iron binding capacity measures the serum iron transporting capacity of: A) hemoglobin B) ceruloplasmin C) transferrin D) ferritin

C) transferrin Transport function of transferring

The majority of thyroxine (T4) is converted into the more biologically active hormone: A) thyroglobulin B) thyroid stimulating hormone (TSH) C) triiodothyronine (T3) D) thyrotropin releasing hormone

C) triiodothyronine (T3) 80% of T4 is converted into T3.

An anti-epileptic (or anticonvulsant) used to control seizure disorder is: A) digoxin B) acetaminophen C) lithium D) phenytoin

D) phenytoin Phenytoin (trade name Dilantin) is an anticonvulsant therapeutic drug used to treat seizure disorders.

A hospital technologist is visiting a clinic that has just recently become part of the hospital laboratory's outreach program. The patient samples are processed at the clinic and then sent to the hospital for analysis. Several plasma enzymes results were below the reference range and were questioned by the patients' physicians. All of these patients had their blood collected at this clinic. The technologist observes that the enzyme test are collected using green top tubes containing lithium heparin, as required by the specimen collection guidelines. The specimens are centrifuged within 30 minutes of collection. The plasma is taken off the cells and put into secondary tubes and then placed in the refrigerator if they will be picked up that day, or freezer, if they will be help longer. The clinic is only open three days a week, so specimens not picked up by the courier that day may be picked up until more than 24 hours after the specimen was collected. Which finding could be the cause of the questionable results? A) the use of lithium heparin as the anticoagulant in the blood collection tubes B)centifugation of specimens too soon after collection C)removing the plasma from the cells D)the use of a self-defrosting freezer

D)the use of a self-defrosting freezer The freeze-thaw cycles in self-defrosting freezers can degrade analytes in specimen tubes and cause false low results. The clinic was following the correct procedure by collecting samples into green top tubes containing lithium heparin. Anticoagulated specimens should be centrifuged soon after collection and separated from the cells, either through the use of gel-barrier tubes or separating the plasma into secondary tube. This second option is required if the plasma specimen will be frozen.

A potassium level of 6.8 mmol/L is obtained. Before reporting the results, the first step the MLT should take is to: A)check the serum for hemolysis B)rerun the test C)check the age of the patient D)do nothing, simply report out the result

A)check the serum for hemolysis 98% of the body's potassium is intercellular, therefore hemolysis will cause an increase in serum/plasma K+ levels. When blood sits I spun for as little as two hours, K+ leaks from the red blood cells and serum levels rise dramatically. Platelets also hold K+, so if centrifuging doesn't completely remove platelets an erroneously false high K+ may result.

A serum sample was assayed for bilirubin at 10AM and result was 12mg/dL. The same sample was retested at 3 PM and the result is now 8mg/dL. The most likely explanation for this discrepancy is: A)the reagent had deteriorated B)the sample was exposed to light C)a calculation error in the first assay D)the sample was not refrigerated

B)the sample was exposed to light Bilirubin undergoes oxidation in serum exposed to visible light, resulting in decreased measured bilirubin values.

Which of these statements is true regarding therapeutic drug monitoring (TDM)? A) TDM can be used to detect an interaction between two or more drugs that a patient is taking at the same time B) TDM is of little value for monitoring patient compliance C) TDM results will always be the same for all patients who are taking the same dosage of the same medication D) TDM is no longer necessary if a patient's therapeutic drug test result remains the same for three testing periods

A) TDM can be used to detect an interaction between two or more drugs that a patient is taking at the same time TDM can be used to detect an interaction between two or more drugs that a patient is taking at the same time. TDM can be used to determine patient compliance with taking therapeutic medication. It will indicate if a patient is failing to take the medication as directed. Therapeutic drugs are not necessarily utilized at the same rate by every individual so that drug doses may need to be adjusted on an individual basis; one size does not fit all. TDM will help the physician to determine the correct dosage for each individual. Therapeutic drug responses may not necessarily remain consistent for be same individual throughout the period of time that they are taking the drug. Even if a test result constant for several testing periods, circumstances, such as temporary illness or pregnancy may affect drug distribution, metabolism or elimination. The dose of the therapeutic drug may need to be adjusted in this case, based on the results of the TDM.

A 48 year old woman presents to her primary health care provider with complaints of anxiety and rapid heartbeat. She also states that she that she has been losing weight in recent months, which at first she attributed to the pressures of increased responsibilities with feeding and caring for the animals on the farm after their farmhand quit. After reviewing additional symptoms and history the physician orders a TSH, suspecting hyperthyroidism (thyrotoxicosis). The phlebotomist consults the laboratory's specimen requirement manual and collects a blood sample using a red top tube. A chemiluminescent immunoassay method is used for the test. The result of the TSH is 0.45 uU/mL (reference interval 0.35-4.2 uU/mL), which is higher than expected and does not correlate with the patient's clinical symptoms, medical history, and other testing. The physician requests a recollection and a second test 48 hours later. The test result is again within the laboratory's reference interval for this method. If the patent's diagnosis is hyperthyroidism and the physician is e petting the TSH to be below normal reference range to support this diagnosis, what could explain a TSH that is falsely elevated into normal reference range? A) a heterophile antibody present in the patient's plasma may be interfering with the test B) the assay may be showing a high concentration prozone (hook) effect C) both test were performed incorrectly

A) a heterophile antibody present in the patient's plasma may be interfering with the test The patient stated that she has been tending to the farm animals on a routine basis. Patients who are routinely exposed to animals may be prone to production of heterophile antibodies, which may have the potential to interfere with some TSH immunoassay methods. A high concentration prozone effect is not a consideration in this case. A prozone effect occurs when there is an excess of antigen, or in this case TSH, that causes the antibody reagent to be overwhelmed. This patient has depressed levels of TSH. It is unlikely that operator error is responsible for the falsely elevated test result as two tests on different days were performed.

A critically ill patient becomes comatose. The physician believes the coma is due to hepatic failure. The assay most helpful in this diagnosis is: A) ammonia B) ALT C) AST D) GGT

A) ammonia Hyperammonia to detect encephalopathy.

Which of the following enzymes are used in the diagnosis of acute pancreatitis? A) amylase and lipase B)AST and ALT C)5'-nucleotidase and GGT D)AST and LD

A) amylase and lipase Amylase and lipase are hydrolases involved in the breakdown of starch and glycogen, and lipid metabolism, respectively. Both enzymes are primarily located in the pancreas. Disorders of the pancreas are characterized by elevated levels of the enzyme. 5'-NT, GGT, AST,and LD are elevated in the liver and the hepatobiliary diseases.

An increase in serum acetone is indicative of a defect in the metabolism of: A) carbohydrate B) fat C) urea nitrogen D) uric acid

A) carbohydrate If there is not enough glucose to the cells the body will mobilize fat and protein for energy. Ketone bodies (acetoacetic acid, acetone, and hydroxybutyric acid) are by-products. Elevated ketone levels can be caused by metabolic disorders of carbohydrates (diabetis), starvation, vomiting, and alcoholism.

A cardiac glycoside that is used in treatment of congenital heart failure and arrhythmias by increasing the force and velocity of myocardial contraction is: A) digoxin B) acetaminophen C) lithium D) phenytoin

A) digoxin Digoxin at therapeutic serum level (0.5-1.5 ng/mL) improves cardiac muscle contraction and rhythm.

The osmolality of a urine or serum specimen is measured by a change in the: A) freezing point B) sedimentation point C) midpoint D) osmotic pressure

A) freezing point Osmometry of serum and other body fluids is commonly measured by freezing-point depression, using a freezing point osmometer.

In competitive inhibition of a enzyme reaction: A) inhibitor bonds to the enzyme at the same site as does the substrate B) inhibitor often has a chemical structure different to that of the substrate C) activity of the reaction can be decreased by increasing the concentration of the substance D) activity of the reaction can be increased by decreasing the temperature

A) inhibitor bonds to enzyme at the same site as does the substrate Competitive inhibitors bind at the active site of enzymes and compete with the substance for binding sites.

Which of the following would have the greatest impact on gentamicin test results? A) time of collection in relation to drug dosing B) patient fasting status C) serum or plasma specimen that has been transferred to a transport tube D) patient resting status

A) time of collection in relation to drug dosing The time of collection in relation to drug dosing will impact the test result more than any of the remaining choices that are given. Gentamicin is an antibiotic that is usually given intravenously (IV) or intramuscularly (IM). The clinician may request both a peak and a trough specimen collection to establish or verify the therapeutic range. Lipemia may affect some methods, but fasting is not required. A patient's resting status also does not impact a gentamicin test result. Serum or plasma that has been transferred to transport tube will not impact a gentamicin test result. Serum or plasma that has been transferred to transport tube will impact the results of the gentamicin test. Removing the plasma/serum from the cells is recommended.

Which of the following is useful in the detection and management of carcinoma of the prostate? A) total prostate specific antigen B) prostatic acid phosphatase C) human chorionic gonadotropin D alpha fetoprotein

A) total prostate specific antigen Total PSA along with DRE is the recommended screen for prostate cancer in males over 50 years of age.

Calculate the LDL cholesterol from the following data: Total cholesterol = 200 mg/dL HDL cholesterol = 40 mg/dL Triglyceride = 210 mg/dL A)118 mg/dL B)168 mg/dL C)210 mg/dL D) 237 mg/dL

A)118 mg/dL The Friedewald formula is: LDL cholesterol: = total cholesterol - HDL cholesterol - (triglyceride/5)=200-40-(210/5)=118

Plasma for cortisol determinations were collected at 7 AM, after waking the patient, and at 10PM that evening. The cortisol level of the morning sample was higher than the evening sample. This is consistent with: A)a normal finding B)Cushing syndrome C)Addison disease D)hypopituitarism

A)a normal finding The normal variation of serum cortisol is higher at 8AM than 4PM.

The osmolality of a urine or serum specimen is measured by a change in the liver: A)freezing point B)sedimentation point C)midpoint D) osmotic pressure

A)freezing point Osmolality is a measurement of the total number of particles in a solution. It is also affected by the amount of solvent in the system, hence, it is a good indicator of the level of hydration and can be used to give the water dimension to specific electrolyte analysis. Osmometry is a measurement of osmolality by the freezing point method. Osmometers can be used to measure the osmolality of a sample. The freezing point depression method is the most common used method in laboratories around the world because the technology is very sensitive and accurate.

A patient has the following test results: increased serum calcium levels decreased serum phosphate levels increased levels of parathyroid hormone This patient most likely has: A)hyperparathyroidism B)hypoparathyroidism C)nephrosis D)steatorrhea

A)hyperparathyroidism Hyperparathyroidism is the overproduction by the parathyroid glands of a hormone called parathyroid hormone. Parathyroid glands are four pea-sized glands located just behind the thyroid gland in front of the neck. Parathyroid hormone helps the levels of calcium and phosphorus in the body. Diagnosis most often is made by elevated PTH and calcium levels, while PO4 is decreased.

In pH meter, reference electrolytes may include: A)silver-silver chloride B)quinhydrone C)hydroxide D)hydrogen

A)silver-silver chloride The reference pH electrode is often constructed of Ag and AgCl

The cut off concentration for a particular drug of abuse is 300 ng/mL. Which of these controls would be the BEST choice as a positive control if the patients are being tested for compliance in a drug treatment program? A) a control with a concentration of 290 ng/mL B) a control with a concentration of 380 ng/mL C) control with a concentration of 1000 ng/mL

B) a control with a concentration of 380 ng/mL A control with a concentration of 380 ng/mL would be the best choice because it is near, but above, the cut off concentration which is the medical decision point. The control with the concentration of 290 ng/mL would produce a negative result. The control with a concentration of 1000 ng/mL would also give a positive result, but it is best to choose a control that a closer to the medical decision point. Using a control that is very high is a less rigorous monitor of quality than control that is only slightly elevated above the cut off. If a laboratory performs drugs of abuse screening for possible overdose, a high positive control may also be appropriate.

Cerebrospinal fluid for glucose assay should be: A) refrigerated B) analyzed immediately C) heated to 56 degrees Celsius D)stored at room temperature after centrifugation

B) analyzed immediately CSF fluids are not collected in any type of preservatives, therefore the CSF should be analyzed immediately to minimize the effect of glycolysis on glucose.

A salicylate level is performed to detect toxicity caused by ingestion of excess: A) acetaminophen B) aspirin C) ibuprofen D) pseudoephedrine

B) aspirin Salicylate level are used to determine if aspirin (acetylsalicylic acid) toxicity is present. Toxic serum or plasma levels are generally more than 300 ng/mL. Acetaminophen (Tylenol),ibuprofen (Advil), and pseudoephedrine are non aspirin compounds.

A salicylate level is performed to detect toxicity caused by ingestion of excess: A) acetaminophen B) aspirin C) ibuprofen D) pseudoephedrine

B) aspirin Salicylate levels are used to determine if aspirin (acetylsalicyclic acid) toxicity is present. Toxic serum or plasma levels are generally >300 ug/mL.

Which of the following should be avoided when urine specimens are collected and tested for drugs of abuse? A) testing a random urine specimen rather than a first morning specimen B) collecting urine specimens in containers that have preservatives added C) testing urine specimens within one hour of collection D) using specimens for testing that had previously been frozen

B) collecting urine specimens in containers that have preservatives added Urine preservatives should be avoided as they can interfere with some immunoassay. Urine collected at any time of the day can be used for the test; it does not need to be first morning specimen. A freshly collected specimen is optimal for testing. Urine specimens can be stored at 2-8 degrees Celsius for up to 48 hours prior to testing. If prolonged storage is required, specimens can be frozen and stored at temperatures at or below -20 degrees Celsius. Frozen specimens should be thawed and mixed well before testing.

Measurement of urinary human chorionic gonadotropin (hCG) in men can be used to: A) diagnose hypogonadism B) detect testicular tumors C) assess pituitary function D) detect excessive estrogen secretion

B) detect testicular tumors In addition to detection of pregnancy, hCG is frequently used to detect and monitor germ cell tumors of the testis and ovary. hCG levels are also used to diagnose and monitor gestational trophoblastic disease, such as hydatidiform mole, gestational choriocarcinoma, and placental-site trophoblastic tumor.

A drug must be in which of the following states to have therapeutic effects? A) protein bound B) free, not bound to protein C) protein bound and free drug both produce therapeutic effects

B) free, not bound to protein Only free, unbound drugs are able to bind drug receptors and have therapeutic effects.

Increased synthesis of testosterone would be the result of increased secretion of which of these pituitary hormones? A) thyroid stimulating hormone B) luteinizing hormone (LH) C) prolactin D) adrenocorticotropin hormone (ACTH)

B) luteinizing hormone (LH) LH stimulates the synthesis of testosterone. TSH stimulates the thyroid gland to produce thyroxine (T4) and triiodothyronine (T3). Prolactin does not target a specific organ; it's primary function is to stimulate milk production. ACTH stimulates the synthesis of hormones and hormone precursors of the adrenal cortex.

Which of the following lipid results would be expected to be falsely elevated on a serum specimen from a non-fasting patient? A)cholesterol B)triglyceride C)HDL D)LDL

B)triglyceride Food intake can cause a transient increase in the triglyceride level by 50%. The LDL and HDL levels may be decreased by 10%-15% depending on the fat content of the meal.

Analysis of CSF for oligoclonal bands is used to screen for which of the following disease states? A) multiple myeloma B) multiple sclerosis C) myasthenia gravis D) von Willebrand disease

B) multiple sclerosis A CSF oligoclonal band screen looks for antibodies in your CSF. Large bands of antibodies suggest an infection or other disease. If similar bands are not present in your blood, you may have multiple sclerosis. It can also be used to diagnose other inflammatory conditions and neurological diseases. A normal result is no bands or just one band. Multiple bands are an indicator that something is wrong. This is particularly true if similar bands aren't found in the blood. About 70-80% of MS patients have positive oligoclonal bands.

During a normal pregnancy, quantitative human chrionic gonadotropin (hCG) levels peak how many weeks after the last menstrual period? A)2-4 B)8-10 C)14-16 D)18-20

B)8-10 Serum hCG levels peak at 8-10 weeks. hCG levels will double on average every 30-31 hours until they peak, usually around the 9th or 10th week of pregnancy. The levels then decreases slightly until the 16th week where it remains fairly constant until birth.

Which would be decreased in liver disease? A)bilirubin B)albumin C)ammonia D)GGT

B)albumin In liver disease, albumin concentrations decrease because liver protein synthesis is impaired. Bilirubin and GGT are elevated in liver disease and ammonia is elevated if liver disease is severe.

Kernicterus is an abnormal accumulation of bilirubin in: A)heart tissue B)brain tissue C)liver tissue D) kidney tissue

B)brain tissue Kernicterus is bilirubin-induced brain dysfunction. Bilirubin is a highly neurotoxic substance hat may become elevated in the serum a condition known as hyperbilirubinemia. Hyperbiliruninemia may cause bilirubin to accumulate in the gray matter of the central nervous system, potentially causing irreversible neurological damage. Depending on the level of exposure, the effect range from clinically unnoticeable to severe brain damage and even death.

A reciprocal relationship excises between: A)sodium and potassium B)calcium and phosphate C)chloride and CO2 D)calcium and magnesium

B)calcium and phosphate The metabolism of calcium and that of phosphorus are so closely related. More than 99% of the calcium in the body and 80% of the phosphorus are present in the bones as calcium fluorophosphates apatite; the remainder of the calcium and phosphorus have varied and significant functions in the body. Essentially all of the calcium of the blood is present in the serum; however, phosphorus is present mainly in the cells as organic phosphate, with only a small but significant amount occurring in serum as inorganic phosphate.

Given the following results: Alkaline phosphatase slightly increase Aspartate aminotransferace slight increase Alanine aminotransferase slight increase Gamma-glutamyl transferase slight increase This is most consistent with: A)acute hepatitis B)chronic hepatitis C)obstructive jaundice D)liver hemangioma

B)chronic hepatitis Chronic hepatitis is chronic inflammation of the hepatocytes that persist for at least 6 months. The serum enzyme levels maybe variable depending on the condition. ALT, AST, and ALP may be increased by 2 times the upper limit of normal. GGT is slightly increased.

Sodium determination by indirect ion selective electrode is falsely decreased by: A)elevated chloride levels B)elevated lipid levels C)decreased protein levels D) decreased albumin levels

B)elevated lipid levels A whole blood sample consists of total plasma and the erythrocytes. Total plasma consists of a water phase and a number of solid components consisting of proteins and lipids. Usually, the solids in plasma make up approximately 7 percent of the total plasma volume. Water accounts for 93 percent. The electrolytes are present in the plasma water that is interest for the measurement of electrolytes. One measuring technology responds to the electrolyte content in the plasma (indirect ISE). Thereby, the distribution between water and solid phase is of importance, as the protein and lipid contents may vary from the normal and may cause a difference in the reported from the two different measuring technologies. The technology used for the measurement of electrolytes responds to the electrolyte content in the plasma water and reflects the physiological situation, thereby giving the most useful results fro the physician to act upon. This technology is called direct ISE.

In which of the following conditions would a normal level of creatine kinase be found? A)acute myocardial infarction B)hepatitis C)progressive muscular dystrophy D)intramuscular injection

B)hepatitis Creatine kinase (CK) is located in brain tissue and skeletal muscle. Diseases involving the tissue site will increase the level of the enzyme activity. CK activity is not increased in hepatitis.

Which of the following is secreted by the plasma and used for the early detection of pregnancy? A) follicle stimulating hormone (FSH) B)human chorionic gonadotropin (hCG) C) leutinizing hormone (LD) D) progesterone

B)human chorionic gonadotropin (hCG) hCG is the primary marker for early pregnancy. Follicle stimulating hormone (FSH) regulates development, growth, pubertal maturation and reproductive processes. Luteinizing hormone (LH) triggers ovulation and the development of corpus luteum. Progesterone levels rise in the last phase of a woman's monthly cycle, the luteal phase.

The cardiac marker that rises within 2-4 hours of the onset of chest pain during a myocardial infarction is: A)troponin B)myoglobin C)CKMB D)BNP

B)myoglobin Myoglobin is a heme protein found in skeletal and cardiac muscle that has attracted considerable interest as an early marker in IM.it's low molecular weight accounts for its early release profile;myoglobin typically rises 2-4 hours after onset of infarction, peaks at 6-12 hours, and returns to normal within 24-36 hours. Rapid myoglobin assays are available, but overall, they have lack of cardiospecificity. Serial sampling every 1-2 hours can increase the sensitivity and specificity; a rise of 25-40% over 1-2 hours is strongly suggestive of acute MI. However,in most studies, myoglobin only achieved 90% sensitivity for acute MI, so the negative predictive value of myoglobin is not high enough to exclude the diagnosis of acute MI.

TSH is produced by the: A)hypothalamus B)pituitary gland C)adrenal cortex D)thyroid

B)pituitary gland TSH is produced and secreted by the anterior pituitary gland which regulates he endocrine function of the thyroid gland. TSH stimulates the thyroid gland to secrete the hormones thyroxine (T4) and triiodothyronine (T3). TSH production is controlled by thyrotropin-releasing hormone (TRH) which is produced in the hypothalamus.

Aspartate aminotransferase (AST) and alanaine aminotransferase (ALT) are both elevated in which of the following diseases? A)muscular dystrophy B)viral hepatitis C)pulmonary emboli D)infectious mononucleosis

B)viral hepatitis The transferases, ALT and ASTare located primary in the liver. Elevated serum levels of the enzyme are seen in hepatocellular disorders. The levels may be 100 times the upper limit of normal. The ALT level is usually higher than AST. Increased levels of AST are also seen in infectious mononucleosis and muscular dystrophy, but ALT is not elevated on those clinical disorders.

The urine drugs of abuse (DOA) screening test is performed by XYZ laboratory uses cut off values to distinguish between positive and negative results. Values that are at or above the cut off are reported by the instrument as positive. Values that are below the cut off are reported as negative. The chemistry technologist who is running DOA tests from a drug rehabilitation facility wants to be certain that results are accurately reported by the test system and has reverified the cut off value. Which combination of controls that are a available for use would further maximize detection of problems with the test system? A) a high positive control and a negative control that contains none of the measured substance B) a high positive control and a high negative control that is about 25% below the cut off C) a weak positive control that is close to the cut off and a high negative control that is 25% below the cut off D) a weak positive control that is close to the cut off and a negative control that contains none of the measured substance

C) a week positive control that is close to the cut off and a high negative control that is 25% below the cut off The best choice would be weak positive control that is close to the cut off and high negative control that is about 25% below the cut off. The negative and positive controls should be at concentrations that meaningfully confirm performance below and above the cut off for each substance and maximize detection of test system problems. A high positive control and a control that contains non of the measured substance may also be used, but are not optimal for verifying values close to the detection point of the test system.

Serum concentrations of vitamin B12 are elevated in: A) pernicious anemia B) patients on chronic hemodialysis C) chronic granulocytic leukemia D) Hodgkin disease

C) chronic granulocytic leukemia Elevated levels of serum cobalamin may be a sign of serious, even life threatening, disease. Hematologic disorders like chronic myelogeneous leukemia, promyelocytic leukemia, polycythemia vera and also hypereosinophilic syndrome can result in elevated levels of cobalamin. Not surprisingly, a rise of the cobalamin concentration in serum is one of the diagnostic criteria for the latter two diseases. The increase in circulating cobalamin levels is predominantly caused by enhanced production of haptocorrin. Several liver diseases like acute hepatitis, cirrhosis, hepatocellular carcinoma and metastatic liver disease can also be cobalamin release during hepatic cytoysis and/or decreased cobalamin clearance by the affected liver. Although it can be concluded that an observed elevation of cobalamin in blood merits the full diagnostic work up to assess the presence of disease.

What could be an example of ectopic production? A) prolactin production by pituitary tumors B) calcitonin production by thyroid tumors C) growth hormone production by lung tumors D) cortisol production by adrenal tumors

C) growth hormone production by lung tumors Ectopic hormones are hormonal substances produced by benign and malignant tumors derived from tissues that do not normally secrete those hormones. Examples of ectopic hormone production would be ACTH production by oat cell carcinoma of the lung and growth hormone production by bronchogenic carcinomas of the lung. Cortisol and growth hormone are normally secreted by the adrenal gland and anterior pituitary gland respectively. Ectopic hormones are not all cases chemically identical to the native hormone but may be similar enough to cross react in immunoassay methods for the native hormone.

Which of these actions may falsely decrease a serum alcohol result? A) using an alcohol wipe to prepare the venipuncture site prior to specimen collection B) using a serum separator tube to collect the sample C) leaving serum in open tube for one hour prior to testing

C) leaving serum in open tube for one hour prior to testing Ethanol is a volatile substance that can easily evaporate if the specimen is left in open tube. Calibrators, controls, and specimen should not be left uncapped longer than necessary. If an alcohol wipe is used as the antiseptic for venipuncture site preparation, it may falsely increase the serum/plasma ethanol result. A serum separator tube can be used to collect the sample for ethanol testing.

Albumin—Alpha 1—Alpha2—beta—gamma The serum protein electrophoresis pattern is consistent with: A)cirrhosis B)acute inflammation C) monoclonal gammophathy D) polyclonal gammopathy (eg, chronic inflammation)

C) monoclonal gammophathy Abnormal protein of a malignant plasma.

Which of the following hormones regulates normal blood calcium levels? A) thyroxine B) estriol C) parathyroid hormone D) growth hormone

C) parathyroid hormone Parathyroid hormone (PTH) and the hormone vitamin D plays a dominant role in calcium regulation.

A patient brings a 24 hour urine to the laboratory after completing the collection at home. The tests that are ordered are total protein and creatinine clearance. The specimen is mixed, measured, and an aliquot is sent to the chemistry laboratory for testing. The results are questionable. Which one of the following could be a source of inaccuracy? A) mixing the specimen before aliquoting B) refrigerating the urine during the collection period C) patient failing to collect one or more voidings during the 24 hours D) laboratory failing to collect and test a serum protein during the urine collection period.

C) patient failing to collect one or more voidings during the 24 hours The most common source of error with timed urine specimens is unsuccessful collection of the entire specimen by the patient during the time period. The specimen should be mixed before aliquoting and refrigerated if not assayed immediately. A serum protein is not needed for either a 24 hour urine protein or a creatinine clearance assay.

An elevated serum iron with normal iron binding capacity is most likely associated with: A) iron deficiency anemia B) renal damage C) pernicious anemia D) septicemia

C) pernicious anemia Ineffective erythopoiesis, high iron metabolism.

A sample is received from the cardiac unit of your facility for a STAT digoxin level. Your instrument reports the result as 3.0 mg/mL and flags it as a critical value. After repeating the test and confirming the result, what should be your next action? A) repeating the test is sufficient. It can be released in the normal manner B) call the cardiac unit and give the results to whoever answers the phone C) phone the cardiac unit and give the result to the clinical person responsible for the patient's care D) repeat the test using an alternative method

C) phone the cardiac unit and give the results to clinical person responsible for the patient's care The results is flagged as a critical value and needs to be phoned promptly to the patient's clinical caretaker. The person phoning the result must be sure the person receiving the result is qualified to do so. The result has already been reported and, if quality control results are acceptable, an alternative testing method is not necessary.

A patient is is suspected of having illicitly used cannabis in the past 3 weeks but appears normal on presentation. A physician wants the laboratory to test for recent use. A cartridge based rapid immunoassay screening method is used. The tests that are part of this panel and the cut off values for the drug assay are as follows: Drug Assay Cut off Values Amphetamines (AMP) 1000ng/mL Methamphetamines (mAMP) 1000ng/mL Barbiturates (BAR) 300ng/mL Cocaine (COC) 300ng/mL Delta-9-Tetrahydrocannabinol (THC) 50 ng/mL Tricyclic Antidepressants (TCA) 1000ng/mL Opiates (OPI) 300ng/mL If the urine specimen that was tested contained 50 ng/mL of the active chemical found in cannabis, how would the test method report this result? A) equivocal B) negative C) positive

C) positive The result would be reported as positive. Results that are at or above the cut off (threshold) value are reported as positive. The cut off value for the active chemical found in cannabis, delta-9-THC-COOH, is 50 ng/mL. An equivocal range is not defined for urine drug screening procedures.

Daily quality control (QC) testing for a test performed on the chemistry analyzer has failed with both levels of control. Both controls are reported using another set of controls from the current lot and again fail. The technologist performs a calibration and both controls are tested again. The values for both are now acceptable. Which of the following actions is necessary to ensure patient test results have not been affected by the QC failures? More than one answer is correct. Please select all correct answers. A) retest the patient samples that were tested along with the QC run B) retest only the sample that had abnormal values in the run that included the failed QC C) re-evaluate all patients test results since the last acceptable QC testing D) retest all patient samples from the previous week

C) re-evaluate all patient test results since the last acceptable QC testing Patients samples that were tested on the same run as unacceptable QC testing cannot be reported, even those that were within normal range. Once the problem that caused the QC failure has been corrected, the patient samples will need to be retested. However, these are not the only patients results that need to be re-evaluated. Patient test results that were obtained since the last acceptable test run must also be re-evaluate to determine if there is a significant clinical difference in those test results. It is not necessary to evaluate patient test results further back than the last successful QC testing event. Evaluating patient results for an entire week is not required as follow up to a QC failure.

A patient has the following test results: Na 140 mmol/L K 9.4 mmol/L Cl 103 mmol/L CO2 32 mmol/L Glu 110 mg/dL BUN 18 md/dL Creat 0.8 mg/dL Ca 2.6 mg/cL The most likely cause of these results is: A)the patient was fasting B)the specimen was diluted by IV fluid C) the order of draw was not followed during specimen collection D)the analyzer has a plug in the flow cell

C) the order of draw was not followed during specimen collection The order of draw is incorrect. If the lavender top tube is drawn before a green top tube the results will be skewed. The lavender top tube contains K2EDTA. The K2 in the anticoagulant will cause a falsely elevated potassium result while the EDTA chelates the calcium and causes a falsely decreased calcium result. The increase in potassium is usually marked and will appear as a result that is incompatible with life.

What does the concentration of urinary free cortisol mainly reflect? A) total serum cortisol B) conjugated serum cortisol C) unbound serum cortisol D) protein bound serum cortisol

C) unbound serum cortisol Only very small quantities, normally less than 2%, of the total adrenal secretion of cortisol appear in the urine as free cortisol. The majority of cortisol is either metabolized in various tissue or conjugated in the liver and excreted. It is only the serum unconjugated cortisol not bound to corticotropin binding globulin (CBG) or the conjugated cortisol that can be cleared by glomerular filtration in the kidney. Therefore, the measurement of reflection of the mount of conjugated cortisol or the serum total cortisol but, rather only the increase cortisol production that is not accompanied by an increase in serum levels of CBG.

Which of the following chemical determinations may be help in establishing the presence of seminal fluid? A)lactic dehydrogenase (LD) B) isocitrate dehydrogenase (ILD) C)acid phosphatase D)alkaline phosphatase

C)acid phosphatase Approximately 20-30% of seminal fluid is prostatic fluid. The composition of the prostatic fluid is acid phosphatase, citric acid, and proteolytic enzymes. The activity of prostatic acid phosphatase may be measured in seminal fluid for medicolegal cases involving rape.

Why is it possible to measure total bilirubin in neonatal serum sample using direct spectrophotometry, but this technique cannot be used to measure total bilirubin in adult serum sample? A)adult samples are too lipemic B)total bilirubin is too low in an adult sample and would not be measured by this method C)adult samples contain carotene and other pigments that increase the absorbance at the wavelength where bilirubin is measured D)adult samples are too hemolyzed interferes with the measurement

C)adult samples contain carotene and other pigments that increase the absorbance at the wavelength where bilirubin is measured The serum of neonates does not contain carotene and other pigments that increase the absorbance at 454 nm. However, these pigments maybe present in serum from older children and adults. Therefore, the use of the direct spectrophotometric method should be restricted to newborns. Lipemia could interfere with direct spectrophotometric measurements. However, even in adult serum sample by direct spectrophotometric measurements, but the high potential for falsely elevated results prevents it from being usable for adult samples.

The presence of C reactive protein in the blood is an induction of: A) a recent streptococcus infection B) recover from pneumococcal infection C)an inflammatory process D) a state of hypersensitivity

C)an inflammatory process C reactive protein is an acute phase protein increased in inflammation.

Most of the carbon dioxide in the blood is in the form of: A)dissolved CO2 B)carbonate C)bicarbonate ion D)carbonic acid

C)bicarbonate ion The bicarbonate ion (HCO3-) is the major component of CO2 in blood. 70%-75% of CO2 in the body is converted to carbonic acid, which can quickly turn into bicarbonate.

Turbidity in serum suggests elevation of: A) cholesterol B)total protein C)chylomicrons D)albumin

C)chylomicrons Elevated levels of chylomicrons in serum or plasma will result in a turbid specimen. The larger size of the chylomicron will reflect the light, causing a turbid appearance.

A 65 year old patient is being monitored for kidney disease as a precautionary measure because the patient has coronary heart disease. Screening renal tests were recently assayed. The patient's plasma BUN and creatinine and urine protein were all elevated. These show that the patient has likely developed kidney disease. Which of the following would be the most probable result of an estimated glomerular filtration rate (eGFR) if the patient does have renal disease? A)normal eGFR B)increased eGFR C)decreased eGFR D)eGFR is only calculated on children

C)decreased eGFR As a person's renal function decreases and the nephrons ability to clear the blood of waste products and other substances becomes impaired, BUN and creatinine increase in the blood. Blood proteins are lost to urine in the damaged glomerulus and urinary protein increases. As the concentration of waste products increases, the glomerular filtration rate (GFR) decreases. The greater the renal impairment, the lower the volume of blood cleared per minute. The equation used to calculate the eGFR in adults (18 and older) is known as the Modification of Diet and Renal Disease (MDRD) equation. It uses the patient's serum or plasma creatinine value in combination with the patient's age, gender, and race to estimate GFR.

A 25 year old man became nauseated and vomited 90 minutes after receiving a standard 75 g carbohydrate dose for an oral glucose tolerance test. The best course of action is to: A)give the patient a glass of orange juice and continue the test B)start the test over immediately with a 50g carbohydrate dose C)draw blood for glucose and discontinue test D)place the patient in a recumbent position, reassure him, and continue the test

C)draw blood for glucose and discontinue test The oral glucose tolerance test is used as an aid to the diagnosis of diabetes mellitus and gestational diabetes. The ability of the individual to remove an added glucose load from the circulation is measured. Patients with diabetes may have fasting blood glucose levels within the normal range, but are unable to produce sufficient insulin for prompt metabolism of the ingested carbohydrate. As a result, blood glucose rises to abnormally high levels and the eternal to normal is delayed- a decreased tolerance for glucose. If patent vomits during the test, discontinued the test and inform the physician.

Osmolality measurements determine the: A)activity of ions per kilogram of solvent B)grams of dissolved solutes per kilogram of solvent C)moles of dissolved solutes per kilogram of solvent D)equivalent of dissolved solutes per kilogram of solvent

C)moles of dissolved solutes per kilogram of solvent Osmolality is defined as the number of moles of particles per kilogram of water. It is a measure of a solutions concentration and it is irrelevant whether the particles are ions or non-ionized solutes. Therefore, regardless of molecular weight, size, or charge, each dissolved solutes contribute equally to osmolality value.

You need to prepare a (1:4) 1 to 4 dilution of a serum specimen using saline before analysis. Which of the following pipe tying steps would result in this dilution? A)piper 0.5 mL serum, than add 1.0 mL saline B)piper 1.0 mL serum, than add 2.0 mL saline C)piper 1.5 mL serum, than add 4.5 mL saline D)piper 2.0 mL serum, than add 5.0 mL saline

C)piper 1.5 mL serum, than add 4.5 mL saline A 1 to 4 dilution means that a total volume of 4 parts, 1 part sample. The sample volume in choice C is 1.5mL (1 part) and the total volume of the mixture is 6.0 mL or 4 parts; hence a 1 to 4 dilution of the sample is made. Choice A and B are 1:3 dilutions, and choice D is 1:2.5 dilution.

The anion gap is useful for quality control of laboratory results for: A)amino acids and proteins B)blood gas analyzers C)sodium, potassium, chloride, and total CO2 D)calcium, phosphorus, and magnesium

C)sodium, potassium, chloride, and total CO2 Anion gap=Na-(Cl+HCO3) The anion gap is calculated value of the difference in measured anion and anions in serum, plasma, or urine and is used to diagnose metabolic acidosis. A normal anion gap is 3-11 mmol/L, with an average estimated at 6 mmol/L.

Which of the following correctly describes the function of "negative feedback" in the release of pituitary hormones? A)negative feedback signals the hypothalamus to release hormones that cause the pituitary to secrete stimulating hormones B)the pituitary self-regulates the secretion of hormones through the process of negative feedback C)the endocrine glands signal the pituitary through negative feedback to stop releasing hormones when there are sufficient levels of circulating hormones

C)the endocrine glands signal the pituitary through negative feedback to stop releasing hormones when there are sufficient levels of circulating hormones In much the same manner as thermostat signals the furnace to stop producing heat when the house has reached the desired temperature, the endocrine glands will negatively feedback to the pituitary to stop the release of stimulating hormones when there are sufficient levels of circulating hormones. The action of the hypothalamus on the pituitary is positive in that it causes the secretion of hormone to occur rather than stopping the secretion (negative). The pituitary does not self-regulate stimulating hormones through negative feedback. It relies on negative feedback from the endocrine glands to stop the production of hormone.

Total iron-binding capacity measures the serum iron transporting capacity of: A)hemoglobin B)ceruloplasmin C)transferrin D)ferritin

C)transferrin Transferrin is a plasma that transports iron through the blood to the liver, spleen, and bone marrow. The total iron-binding capacity (TIBC) test measures the blood's capacity to bind iron with transferrin, which indirectly measures transferrin since transferrin is the most dynamic carrier. A directly measured Transferrin test is more commonly run now than the indirect TIBC.

A blood creatinine value of 5.0 mg/dL is most likely to be found with which of the following blood values? A)osmolality 292 mOsm/kg B)uric acid 8mg/dL C)urea nitrogen 80mg/dL D)ammonia: 80 ug/dL

C)urea nitrogen 80mg/dL Both BUN and creative are filtered out of the blood by the kidneys. Ammonia is converted to urea in the liver. Serum osmolarity is the measure of the number of dissolved particles per unit of water in serum. A low serum osmolality would accompany overhydration, or edema, and an increase serum osmolality would be present in a state of fluid volume deficit. Both the BUN and creatinine are elevated. The serum osmolality is normal.

Most chemical methods for determining total protein utilize which of the following reactions? A)molybdenum blue B) ferri-ferrocyanide C)resorcinol-HCl D)biuret

D)biuret The biuret method is a chemical test for proteins based on the formation of a violet color when copper sulfate in alkaline solution reacts with a peptide bond.

An increase in which of the following cardiac bio markers is most often associated with congestive heart failure (CHF)? A)troponin I B)myoglobin C)CKMB D)BNP

D)BNP Increases in BNP/NT-proBNP are most often associated with the condition of congestive heart failure (CHF). CHF reflects a myriad of underlying clinical conditions that progress with age and cardiac stress. One of the most common symptoms of CHF is dyspnea, or shortness of breath, so clinical symptoms and patient history play an important role in determining the clinical utility of BNP or NT-proBNP. Troponin I, myoglobin, and, to a less extent, CKMB, are often used as a multi-marker approach to AMI evaluation.

The function of the major lipid components of the very low-density lipoprotein (VLDL) is to transport: A) cholesterol from peripheral cells to the liver B) cholesterol and phospholipids to peripheral cells C) exogenous triglycerides D) endogenous triglycerides

D) endogenous triglycerides In the endogenous pathway for lipid metabolism, the hepatocytes can synthesis triglycerides from carbohydrates and fatty acids. The triglycerides are packaged in VLDL, and ultimately delivered to the circulation in that form. Exogenous triglycerides are transported primarily by chylomicrons. HDL transports cholesterol from peripheral cells to the liver. LDL transports cholesterol and phospholipids to peripheral cells.

Creatinine clearance is used to estimate the: A) tubular secretion of creatinine B) glomerular secretion of creatinine C) renal glomerular and tubular mass D) glomerular filtration rate

D) glomerular filtration rate Glomerular filtration rate is estimated by filtration markers such as creatinine clearance. GFR describes the flow of filtered fluid through the kidneys. Creatinine clearance rate is the volume of the blood plasma that is cleared of creatinine per unit and is a useful measure for approximating the GFR.

A patent had the following results: Patient values Reference range 250 ug/dL. 60-150 ug/dL. Serum iron 350 ug/dL. 300-350 ug/dL TIBC The best conclusion is that this patient has: A) normal iron status B) iron deficiency anemia C) chronic disease D) iron hemochromatosis

D) iron hemochromatosis Features of iron overload hemochromatosis. Primary hemochromatosis is caused by a defect in the genes that control how much iron you absorb from food. Primary hemochromatosis is more common than the secondary form of the disease. Secondary hemochromatosis usually is the result of another disease or condition that cause iron overload. Examples of such disease and conditions include certain types of anemia, thalassemias, alcoholic liver disease, blood transfusion, hepatitis C, etc..

A chemiluminescent: A) measures absorption of light B) is less sensitive than radioisotopic reaction C)is monitored by the use of gamma counter D) is quantitated by the amount of light produced by the reaction

D) is quantitated by the amount of light produced by the reaction Chemiluminescent labels are based on the emission of light produced during a chemical reaction. These labels are very useful because they provide very low levels of detection (2x10^20 mol/L) with little or no background interference.

The first step in analyzing a 24 hour urine specimen for quantitative urine protein is: A) subculture the urine for bacteria B) add the appropriate preservative C) screen for albumin using a dipstick D) measure the total volume

D) measure the total volume Urine protein is used to evaluate and monitor kidney function. 24 hour urines are not used for bacterial cultures because of sterility concerns. The appropriate preservative for a 24 hour urine protein is refrigeration and should be done during collection. Total volume must always be measured for 24 hour urine testing as it is part of the calculation.

Which of the following components determines the wavelength of light that pass through the sample curette in a spectrophotometer? A)detector B)light source C)potentiometer D)monochromator

D) monochromator The monochromator isolates the desired wavelength of light (monochrmatic light) and excludes that of other wavelengths.

Daily quality control (QC) testing for a test performed on the chemistry analyzer has failed with both levels of control. Both controls are repeated using another set of controls from the current lot and again fail. Which of the actions shown below would be MOST appropriate at this point? A) open a new set of daily controls and retest until the values are acceptable B) call technical service to repair the instrument C) send all the chemistry tests to the reference laboratory D) recalibrate the instrument

D) recalibrate the instrument Failed QC indicates that there may be a problem with the calibration settings (signal versus analyte content). Repeatedly retesting quality control will not solve the problem; it will only continue to point out that there is a problem that needs to be solved. It is still premature to request a service call or to send out all chemistry testing. This may be necessary if calibration fails to solve the problem, recalibrate should first be done.

Which of the following statements most correctly describes the utility of clinical laboratory assays for tumor markers? A) tumor markers are useful to screen asymptomatic patients for tumors B) tumor markers are highly specific C) tumor markers indicate the likelihood of an individual developing a tumor D) tumor markers are useful in tracking the efficacy of treatment

D) tumor markers are useful in tracking the efficacy of treatment Tumor markers are used mainly in patients who have already been diagnosed with cancer to watch their response to treatment or look for the return of cancer after treatment. Tumor markers are substances that can be found in the body (usually in the blood or urine) when cancer is present. Most tumor markers are proteins, but newer tumor markers are genes or other substances. Some are seen in only a single type of cancer while others can be found in many types of cancers. Along with other tests, tumor markers can be used to help show if cancer is present, to determine the type of cancer, and to help show if treatment is working. Screening at an early stage, show it is less likely to have spread and easier to treat. Tumor markers were first developed to test for cancer without symptoms, but very few markers have been shown to be helpful in this screen way. The most widely used tumor marker is the prostate-specific antigen (PSA) blood test, which is used to screen men for prostate cancer. So far no their tumor marker has been shown to help screen for cancer in the general population.

The most widely used methods for bilirubin measurement are those based on the: A)Jaffe reaction B)Schales and Schales method C)8-hydroxyquinoline reaction D)Jendrassik-Grof method

D)Jendrassik-Grof method The Jendrassik-Grof method is used for measuring bilirubin. Jaffe reaction measures creatinine, Schales and Schales is a method for determining chloride in tissue, and the 8-hydroxyquinoline reacts with aluminum and copper salts.

Blood samples were collected at the beginning of an exercise class and after thirty minutes of aerobic activity. Which of the following would be most consistent with the post-exercise sample? A)normal lactic acid, low pyruvate B)low lactic acid, elevated pyruvate C)elevated lactic acid, low pyruvate D)elevated lactic acid, elevated pyruvate

D)elevated lactic acid, elevated pyruvate Lactate and pyruvate are products of glycolysis. During power exercises, such as sprinting, when the rate of demand for energy is high, lactate up produced faster than the ability of the tissue to remove it, so lactate concentration begins to rise. This is a beneficial process since the regeneration of NAD ensures that energy production is maintained and exercise can continue. The increased lactate produced can be removed in a number of ways, including oxidation to pyruvate, by well-oxygenated muscle cells. Pyruvate is then directly used to fuel the Karen cycle.

Which of the following serum constituents is unstable if a blood specimen is left standing at room temperature for 8 hours before processing? A)cholesterol B)triglyceride C)creatinine D)glucose

D)glucose Glucose decreases at a rate of 5%-7% per hour in whole blood at room temperature. Glycolysis will continue until the specimen is processed by centrifugation, and serum and plasma is separated from the cellular components of blood.

The enzyme present in almost all tissue may be separated by electrolytes in 5 components is: A)lipase B)transaminase C)creatinine kinase D)lactate dehydrogenase

D)lactate dehydrogenase Lactate dehydrogenase ( LD) catalyzes the interconversion of lactic and pyruvic acids. Electrophoretically, using agarose or cellulose acetate medium, LD can be separated into 5 isoenzymes, LD1-LD5. CK and lipase have 3 isoenzymes; AST has 2.

To make a diagnosis of hypoglycemia in adults the glucose value following an overnight fast would be: A) less than or equal to 70 mg/dL B)less than or equal to 60 mg/dL C)less than or equal to 55 mg/dL D)less than or equal to 45 mg/dL

D)less than or equal to 45 mg/dL Normal blood sugar levels range from 70-100 mg/dL upon waking and 40-140 mg/dL following meals. For those with diabetes, fasting glucose levels should be between 90-130 mg/dL, and a 2 hour postprandial glucose should be less than 180 mg/dL. A blood sugar level of 70 mg/dL or less is defined as hypoglycemia. Diagnosis of hypoglycemia requires fasting blood glucose values of less than 50 mg/dL of less than 70 mg/dL after ingesting food or drink.

Lithium therapy is widely used in the treatment of: A) hypertension B) hyperactivity C)aggression D)manic depression(bipolar) disorder

D)manic depression(bipolar) disorder Lithium(carbonate) us used to treat depression or bipolar disorder.

A 45 year old woman complains of fatigue, heat intolerance and hair loss. Total and free T4 are abnormally low. If the TSH showed marked elevation, this would be consistent with: A)Graves disease B)an adrenoma of the thyroid C)thyrotoxicosis D)primary hypothyroidism

D)primary hypothyroidism Increased TSH, decreased free T4 and total T4, positive microsomal Ab are consistent with primary hypothyroidism.

Which of the following electrolytes is the chief plasma cation whose main function is maintaining osmotic pressure? A)chloride B)calcium C)potassium D)sodium

D)sodium Sodium is the chief cation in osmotic pressure. Sodium regulates blood volume, blood pressure, osmotic equilibrium, and pH.

Erroneous ammonia levels can be eliminated by all of the following except: A)assuming water and reagents are ammonia-free B)separating plasma from cells and performing test analysis as soon as possible C) drawing the specimen in a ore-chilled tube and immersing the tube in ice D)storing the specimen protected from light until the analysis is do e

D)storing the specimen protected from light until the analysis is done Most ammonia in the body forms when protein is broken down by bacteria in the intestines. The liver normally converts ammonia into urea, which is then eliminated in urine. Ammonia levels in the blood rise when the liver is not able to convert ammonia to urea. Elevated levels may be found in cirrhosis or hepatitis, Reye syndrome, heart failure, kidney failure, or severe bleeding from the stomach or intestines. To obtain an accurate measurement, the blood sample for ammonia testing must be obtained and handled properly. Prolonged application of tourniquet or fist clenching while obtaining the blood, or improper specimen handling can result in a falsely elevated ammonia level. Lower temperatures retard the increase in ammonia in stored plasma. If the sample cannot be analyzed promptly (within 1 hour) it should be frozen. Accurate measurement of plasma ammonia is difficult because concentrations in blood are low compared with values from potential containing detergents, adversely affect reproducibility of plasma ammonia measurement. Light is not a factor in the spurious increase or decrease of ammonia levels.

Which of the following statements about hexokinase reaction for serum glucose quantitation is true? A)the amount of hydrogen peroxide produced is measured B)during the reaction cupric ions are reduced to cuprous ions C)the reaction generates a green condensation product with a-toluidine D)the coupled indicator reaction generates NADPH from glucose-6-phosphate

D)the coupled indicator reaction generates NADPH from glucose-6-phosphate Hexokinase catalyzes the phosphorylation of several monosaccharides using ATP as the phosphate donor and produces the corresponding sugar-6-phosphate. During the reaction, glucose-6-phosphate dehydrogenase (G-6-PD), catalyzes the reaction of glucose-6-phosphate and NADP. It is the high specificity of the indicator reaction that prevents interference from other monosaccharides.

When using an automated instrument, the amount of carryover between consecutive samples is not affected by: A)rinsing the probe between samples B)separating consecutive samples in tubing by air segments C)using a separate reaction chamber for each sample D)using a serum blank

D)using a serum blank Carryover is the percent error produced by interaction or cross contamination between adjacent samples. All techniques that rinse the components that touch adjacent samples or that increase the physical separation between adjacent samples decrease carryover.