MLT Chemistry Class 1120

The probable explanation for the result on day 4 is that the specimen had prolonged exposure to light. This is because the bilirubin level significantly decreased from day 3 to day 4, which is unlikely to happen naturally. Prolonged exposure to light can cause the breakdown of bilirubin, leading to lower levels in the sample. The other options, such as using serum instead of plasma or specimen being hemolyzed, do not explain the sudden decrease in bilirubin levels.

Urobilinogen is formed in the intestine. This is because urobilinogen is a byproduct of the breakdown of bilirubin, which is produced in the liver and then excreted into the bile. In the intestine, bilirubin is further broken down by bacteria, leading to the formation of urobilinogen. From there, urobilinogen can be further metabolized and excreted in the urine or feces.

Amylase is the correct answer because it is an enzyme that catalyzes the conversion of starch to glucose and maltose. Starch is a complex carbohydrate made up of many glucose molecules linked together, and amylase breaks down these bonds to release glucose and maltose. Malate dehydrogenase, creatine kinase, and isocitric dehydrogenase are enzymes involved in other metabolic pathways and do not play a role in starch digestion.

The buffering capacity of blood is maintained by a reversible exchange process between bicarbonate and chloride. This process helps to regulate the pH of the blood by balancing the levels of acid and base. Chloride ions play a crucial role in this process as they can easily move across cell membranes and participate in the exchange of bicarbonate ions. This exchange helps to maintain the acid-base balance in the blood and ensures that the pH remains within the normal range.

The correct answer is pituitary gland. The pituitary gland is responsible for producing and releasing various hormones, including the thyroid-stimulating hormone (TSH). TSH plays a crucial role in regulating the production and release of thyroid hormones from the thyroid gland. It stimulates the thyroid gland to produce and release thyroxine (T4) and triiodothyronine (T3), which are essential for the regulation of metabolism, growth, and development in the body. Therefore, the pituitary gland is directly involved in the production of TSH.

Clinical assays for tumor markers are most important for monitoring the course of a known cancer. This is because tumor markers are substances that are produced by cancer cells or by the body in response to cancer. By measuring the levels of these markers in the blood or other body fluids, healthcare professionals can track the progression or regression of a known cancer. This helps in assessing the effectiveness of treatment, determining the need for additional therapies, and monitoring the overall health status of the patient.

not-available-via-ai

Glycated hemoglobin (HbA1c) is a measure of the average blood glucose levels over a period of time. It reflects the amount of glucose that has attached to hemoglobin molecules in red blood cells. As red blood cells have a lifespan of around 120 days, HbA1c provides an indication of blood glucose control over the previous 2-3 months. Therefore, the correct answer is 6-8 weeks, as this timeframe aligns with the lifespan of red blood cells and provides an accurate representation of long-term glucose levels.

In chronic renal failure, the kidneys are unable to effectively remove metabolic waste products, such as acids, from the body. This leads to an accumulation of acid in the blood, resulting in metabolic acidosis. The expected blood gas results for a patient in chronic renal failure would show decreased pH, decreased bicarbonate levels, and possibly decreased pCO2 levels. This pattern is consistent with metabolic acidosis.

The parathyroid glands are responsible for controlling fasting serum phosphate concentration. These glands produce and release parathyroid hormone (PTH), which plays a crucial role in regulating phosphate levels in the blood. PTH acts on the bones, kidneys, and intestines to increase phosphate reabsorption and decrease phosphate excretion. This helps maintain a stable phosphate concentration in the blood, which is important for various physiological processes such as bone health, energy metabolism, and cellular function.

To assure an accurate ammonia level result, the specimen should be spun to separate the liquid part (serum or plasma) from the cells. Then, it should be immediately iced to prevent any further metabolism or degradation of ammonia. Finally, the specimen should be tested as soon as possible to minimize any potential changes in ammonia levels. This process ensures that the ammonia level result is reliable and reflective of the true concentration in the specimen.

The correct answer is a high carbohydrate diet for 3 days. This is because glucose tolerance testing is used to diagnose diabetes or assess insulin resistance. By consuming a high carbohydrate diet for several days prior to the test, it ensures that the body has a sufficient amount of carbohydrates to measure how well it processes glucose. This helps in obtaining accurate results and ensures that the test is effective in diagnosing or monitoring the patient's condition.

A 2 hr postprandial glucose value of 200 mg/dl (11. mmol/L) demonstrates unequivocal hyperglycemia diagnostic for diabetes mellitus. This level of blood glucose after a meal indicates that the body is unable to effectively regulate blood sugar levels, which is a characteristic feature of diabetes mellitus.

The laboratory results show an increased level of calcium in the serum and urine, along with a decreased level of alkaline phosphate in the serum. These findings are most commonly seen in primary hyperparathyroidism, a condition characterized by excessive production of parathyroid hormone (PTH) by the parathyroid glands. Increased PTH leads to increased calcium levels in the blood and urine, while also causing a decrease in alkaline phosphate levels. This combination of findings is consistent with primary hyperparathyroidism.

Hypoglycemia in adults is defined as a low blood glucose level. The correct answer, option d, suggests that the glucose level after overnight fasting is below the normal range, indicating hypoglycemia.

A fasting plasma glucose level of 126 mg/dl (6.9 mmol/L) is diagnostic of diabetes mellitus according to the criteria set by the American Diabetes Association. A fasting plasma glucose level of 110 mg/dl (6.1 mmol/L) is within the normal range, and a 2-hour specimen glucose level of 150 mg/dl (8.3 mmol/L) and 180 mg/dl (9.9 mmol/L) are elevated but not diagnostic of diabetes.

Angiotensin II is a hormone that plays a significant role in regulating blood pressure. One of its major actions is increased vasoconstriction, which means that it causes the blood vessels to constrict or narrow. This narrowing of blood vessels leads to an increase in blood pressure. By constricting the blood vessels, angiotensin II helps to regulate blood flow and maintain adequate blood pressure throughout the body. This action is important in situations where the body needs to increase blood pressure, such as during times of low blood volume or low blood pressure.

Serum albumin is a protein found in the blood that plays a crucial role in maintaining the colloidal osmotic pressure. Colloidal osmotic pressure is the pressure exerted by proteins, such as albumin, in the blood vessels that helps to keep fluid within the blood vessels and prevent it from leaking into the surrounding tissues. This is important for maintaining proper fluid balance in the body and preventing edema. Therefore, the primary function of serum albumin in the peripheral blood is to maintain colloidal osmotic pressure.

Elevated prostate-specific antigen (PSA) levels can occur due to various reasons other than prostate carcinoma. One of these reasons is benign prostatic hyperplasia (BPH), a non-cancerous condition where the prostate gland enlarges. BPH can cause PSA levels to rise because the enlarged prostate puts pressure on the urinary tract, leading to increased PSA production. Aspirin therapy, exogenous steroid use, and statin therapy (cholesterol-lowering drug) are not typically associated with elevated PSA levels.

In the fasting state, the arterial blood and the capillary blood glucose concentration are higher than the venous glucose concentration by approximately 5 mg/dl (0.27 mmol/L). This means that the glucose levels in the arteries and capillaries are slightly elevated compared to the venous blood.

Ceruloplasmin is a protein found in the blood that plays a crucial role in copper transport and metabolism. It binds to copper ions, allowing them to be transported throughout the body. Therefore, it is responsible for binding and carrying approximately 90% of the copper present in the blood. Transferrin is a protein that binds and transports iron, not copper. Albumin is a protein that carries various substances in the blood, but it does not specifically bind to copper. Cryoglobulin is a protein complex that can be found in certain medical conditions, but it is not involved in copper binding.

In this case, the most informative additional laboratory test would be the serum thyroid-stimulating hormone (TSH) level. The description of the child being somewhat dwarfed, stocky, overweight, and having coarse features suggests a possible thyroid disorder, specifically hypothyroidism. Hypothyroidism in children can cause growth retardation and weight gain. TSH is the hormone that stimulates the thyroid gland to produce thyroid hormones, and an elevated TSH level would indicate that the thyroid gland is not functioning properly. Therefore, measuring TSH levels would provide important information about the child's thyroid function and help confirm the diagnosis of hypothyroidism.

Aldosterone is an adrenal cortical hormone because it is produced by the adrenal cortex, which is the outer layer of the adrenal gland. This hormone plays a crucial role in regulating the balance of water and electrolytes in the body, particularly by promoting the reabsorption of sodium and the excretion of potassium in the kidneys. Aldosterone also helps to regulate blood pressure and maintain overall fluid balance in the body. Therefore, among the given options, aldosterone is the only steroid that fits the description of being an adrenal cortical hormone.

Pre-term or low birth weight infants have underdeveloped organs, including the liver, which is responsible for regulating blood sugar levels. As a result, their serum levels are lower than those of adults. This is because their bodies are not yet capable of producing and regulating glucose at the same level as fully developed adults. Therefore, their serum levels defining hypoglycemia are lower than adults.

Calcium and phosphate have a reciprocal relationship because they are both essential minerals that work together in various bodily functions. Calcium is necessary for strong bones and teeth, while phosphate plays a crucial role in energy production and cell signaling. These minerals interact in a reciprocal manner, with calcium aiding in the absorption of phosphate and phosphate helping to regulate calcium levels in the body. This reciprocal relationship ensures the proper balance and functioning of these minerals in maintaining overall health and well-being.

Lactate dehydrogenase is the correct answer because it is an enzyme that is present in almost all tissues and can be separated into 5 components using electrophoresis. This enzyme is involved in the conversion of lactate to pyruvate during anaerobic respiration and is commonly used as a biomarker for tissue damage or disease.

A scanning of a CK isoenzyme fractionation revealed 2 peaks: a slow cathodic peak (CKMM) and an intermediate peak (CKMB). This pattern is indicative of myocardial infarction. CKMB is a cardiac-specific isoenzyme of creatine kinase, and its presence in the fractionation indicates damage to the heart muscle. The slow cathodic peak (CKMM) represents the skeletal muscle isoenzyme, which may also be elevated in myocardial infarction due to the release of CK from damaged heart tissue. Therefore, the presence of both CKMB and CKMM peaks suggests myocardial infarction as the most likely explanation.

Gamma-glutamyl transferase (GGT) is the most sensitive enzymatic indicator for liver damage from ethanol intake. GGT is primarily found in the liver and is involved in the metabolism of glutathione, a potent antioxidant. Elevated levels of GGT in the blood indicate liver dysfunction or damage, particularly from alcohol abuse. GGT levels are more specific to liver damage caused by alcohol compared to other liver enzymes like alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Therefore, GGT is considered the most reliable marker for assessing ethanol-induced liver damage. Alkaline phosphatase is not as specific to liver damage from ethanol intake as GGT.

The patient's fasting blood glucose level is higher than the reference range, indicating a state of flux and progressively worsening metabolic control. However, the patient's fructosamine level is within the reference range, indicating an improving state of metabolic control. Therefore, the correct answer is that the patient is in an improving state of metabolic control as indicated by fructosamine.

Kernicterus is a condition characterized by the buildup of bilirubin in the brain tissue. Bilirubin is a yellow pigment that is produced when red blood cells break down. In normal circumstances, it is processed by the liver and excreted from the body. However, in cases of excessive bilirubin production or impaired liver function, such as in newborns with jaundice, bilirubin can accumulate in the brain and cause damage. This can lead to neurological problems, including developmental delays, hearing loss, and movement disorders. Therefore, the correct answer is brain tissue.

A person with hemolytic anemia will show a decrease in glycated hgb value because hemolytic anemia is a condition where red blood cells are destroyed faster than they can be produced. Glycated hemoglobin (hgb) is a measure of the average blood sugar levels over the past 2-3 months. In hemolytic anemia, the lifespan of red blood cells is shortened, leading to a decrease in the amount of time available for glucose to bind to hemoglobin. As a result, there will be a decrease in the glycated hgb value.

Specimen hemolysis can cause falsely increased LD1 fraction of lactic dehydrogenase. Hemolysis refers to the breakdown of red blood cells, which can release LD1 into the bloodstream. This can lead to an elevated LD1 fraction, which is a specific form of lactic dehydrogenase found in red blood cells. Liver disease, congestive heart failure, and drug toxicity are not known to directly cause an increase in LD1 fraction, making specimen hemolysis the most likely cause.

A blood creatinine value of 5.0 mg/dL (442 umol/L) is most likely to be found with a high urea nitrogen level of 80 mg/dL (28.56 mmol/L). Creatinine and urea nitrogen are both waste products that are filtered out by the kidneys. When the kidneys are not functioning properly, these waste products can build up in the blood, leading to elevated levels. Therefore, a high urea nitrogen level is consistent with a high creatinine level, indicating impaired kidney function.

The recommended initial thyroid function test for either a healthy asymptomatic patient or a patient with symptoms related to a thyroid disorder is thyroid-stimulating hormone (TSH). TSH is produced by the pituitary gland and stimulates the thyroid gland to produce thyroid hormones. TSH levels are the most sensitive indicator of thyroid dysfunction and can help identify both hypo- and hyperthyroidism. TSH levels outside the normal range can indicate an underlying thyroid disorder and further testing may be required to determine the specific condition. Therefore, TSH is the most appropriate initial test to assess thyroid function.

After thirty minutes of aerobic activity, the body goes through a process called glycolysis, in which glucose is broken down to produce energy. This process produces lactic acid as a byproduct. Therefore, the post-exercise sample would have elevated levels of lactic acid. Additionally, pyruvate is an intermediate product of glycolysis, so it would also be expected to be elevated in the post-exercise sample. Therefore, the answer "elevated lactic acid, elevated pyruvate" is the most consistent with the post-exercise sample.

The given symptoms of fatigue, heat intolerance, and hair loss, along with abnormally low total free T4 levels, suggest a decrease in thyroid hormone production. If the TSH levels are markedly elevated, it indicates that the pituitary gland is trying to stimulate the thyroid to produce more hormones, but the thyroid is unable to respond adequately. This pattern is consistent with primary hypothyroidism, where there is a dysfunction in the thyroid gland itself leading to decreased thyroid hormone production.

Carcinoembryonic antigen (CEA) is a protein that is usually produced during fetal development but can also be produced in certain types of cancer. It is commonly used as a tumor marker for colorectal cancer. Therefore, the correct answer is colon, as it is most likely to be produced in a malignancy involving the colon.

An emphysema patient suffering from fluid accumulation in the alveolar spaces is likely to be in a state of respiratory acidosis. Emphysema is a chronic lung disease that causes damage to the alveoli, leading to impaired gas exchange. Fluid accumulation in the alveolar spaces further impairs the exchange of oxygen and carbon dioxide. This results in a buildup of carbon dioxide in the blood, leading to respiratory acidosis, which is characterized by low blood pH and high levels of carbon dioxide.

Respiratory acidosis is a condition characterized by an increase in carbon dioxide (CO2) content and partial pressure of carbon dioxide (PCO2) in the blood, which leads to a decrease in pH. This occurs when the lungs are unable to effectively remove CO2 from the body, causing it to accumulate in the bloodstream. The increased CO2 levels result in the formation of carbonic acid, leading to a decrease in pH and an acidic environment.

Lipase is the most specific enzyme test for acute pancreatitis. Lipase is an enzyme produced by the pancreas that helps in the digestion of fats. In cases of acute pancreatitis, there is inflammation of the pancreas which leads to the leakage of lipase into the bloodstream. Therefore, measuring the levels of lipase in the blood can help in diagnosing acute pancreatitis. Other enzymes like amylase and trypsin can also be elevated in pancreatitis, but lipase is considered more specific to the condition. Acid phosphatase is not typically used as an enzyme test for pancreatitis.

An increase in serum acetone is indicative of a defect in the metabolism of carbohydrates. This is because acetone is produced when the body breaks down fats for energy in the absence of sufficient carbohydrates. When carbohydrates are not properly metabolized, the body starts using fats as an alternative energy source, leading to the production of acetone. Therefore, an increase in serum acetone suggests that there is a problem with the metabolism of carbohydrates.

The diffusion characteristics of the membrane play a significant role in the time it takes for a PCO2 electrode to reach equilibrium. The membrane acts as a barrier between the sample and the electrode, allowing the diffusion of CO2 molecules. If the membrane has low permeability or thickness, it can impede the diffusion process, resulting in a longer time for the electrode to reach equilibrium. On the other hand, a membrane with high permeability or thinness allows for faster diffusion, reducing the time required for equilibrium to be reached. Therefore, the diffusion characteristics of the membrane directly affect the time it takes for the PCO2 electrode to reach equilibrium.

The laboratory results show a low pH (7.32) and a high PCO2 (79 mm Hg), indicating respiratory acidosis. In respiratory acidosis, there is an accumulation of carbon dioxide in the blood due to inadequate ventilation, leading to an increase in PCO2 and a decrease in pH. The other options (respiratory alkalosis, metabolic alkalosis, and metabolic acidosis) do not match the laboratory findings in this case.

Vanillymandelic acid (VMA) is the correct answer because it is a urinary excretion product that is measured as an indicator of epinephrine production. Epinephrine is a hormone produced by the adrenal glands in response to stress or excitement, and VMA is a metabolite of epinephrine. Therefore, measuring the levels of VMA in the urine can provide information about the production of epinephrine in the body.

Clinical laboratory assays for tumor markers are useful in tracking the efficacy of treatment. Tumor markers are substances that are produced by tumor cells or by the body in response to the presence of a tumor. By measuring the levels of these markers in the blood or other body fluids, healthcare professionals can monitor the progress of treatment and determine if it is effectively reducing the tumor burden. This information is valuable in making decisions about the continuation or modification of treatment plans. However, tumor markers are not typically used for screening asymptomatic patients for tumors or for predicting the likelihood of developing a tumor.

The best method to diagnose lactase deficiency is the h2 breath test. This test measures the levels of hydrogen in the breath after consuming a lactose-rich beverage. Lactase deficiency leads to the undigested lactose being fermented by bacteria in the colon, producing hydrogen gas that is absorbed into the bloodstream and exhaled through the breath. Elevated levels of hydrogen indicate lactose malabsorption, confirming the diagnosis of lactase deficiency. The h2 breath test is a non-invasive and reliable method for diagnosing lactase deficiency.

Severe diarrhea causes metabolic acidosis because the loss of fluids and electrolytes through diarrhea leads to an imbalance in the body's acid-base levels. The excessive loss of bicarbonate ions in the stool causes a decrease in the body's buffering capacity, resulting in an accumulation of acid and a decrease in pH. This leads to metabolic acidosis, characterized by symptoms such as increased breathing rate, confusion, and fatigue.

A glucose level of 722 mg/dl (39.7 mmol/L) and serum acetone of 4+ undiluted indicate that the patient is most likely experiencing diabetic ketoacidosis (DKA). DKA is a serious complication of diabetes characterized by high blood glucose levels, ketones in the blood, and metabolic acidosis. Metabolic acidosis is associated with a low pH level in the arterial blood gas. Therefore, the arterial blood gas from this patient is likely to show a low pH.

The correct answer is lactic acidosis. Lactic acidosis is a condition characterized by the accumulation of lactic acid in the body. This can occur due to various reasons, such as impaired oxygen delivery to tissues, impaired lactate metabolism, or increased lactate production. In lactic acidosis, the body's ability to clear lactic acid is compromised, leading to an increase in the anion gap. The anion gap is a measure of the difference between the concentrations of positively charged ions (sodium and potassium) and negatively charged ions (chloride and bicarbonate) in the blood. An increased anion gap is indicative of an underlying metabolic acidosis, which is commonly seen in lactic acidosis.

Beriberi is a disease that is caused by a deficiency of thiamine, also known as vitamin B1. Thiamine is an essential nutrient that plays a crucial role in the metabolism of carbohydrates, as well as the proper functioning of the nervous system. A deficiency of thiamine can lead to symptoms such as weakness, fatigue, nerve damage, and cardiovascular problems, which are all characteristic of beriberi. Niacin, vitamin A, and vitamin C deficiencies are associated with other health conditions, but not beriberi.

The correct answer is BUN, creatinine, salicylate, and methanol. An anion gap of 22 mEq/L suggests an imbalance of electrolytes in the body. BUN and creatinine are markers of kidney function and can help determine if there is a renal cause for the anion gap. Salicylate and methanol are toxic substances that can cause an increased anion gap. Therefore, testing for these substances can help identify potential causes for the abnormal anion gap. The other options listed do not directly relate to the evaluation of an anion gap.

The patient's thyroid profile shows decreased levels of total T4, free T4, and TSH, along with a positive result for thyroid peroxidase antibody. These findings are consistent with hypothyroidism, which is a condition characterized by an underactive thyroid gland. In hypothyroidism, the thyroid gland does not produce enough thyroid hormones, leading to a decrease in total and free T4 levels. The decrease in TSH is a compensatory response by the body to try to stimulate the thyroid gland to produce more hormones. The presence of thyroid peroxidase antibody suggests an autoimmune cause for the hypothyroidism, which can be seen in conditions such as Hashimoto's thyroiditis.

A normal level of creatine kinase would be found in hepatitis. Creatine kinase is an enzyme that is released into the bloodstream when there is damage to muscle tissue. In conditions such as acute myocardial infarct, progressive muscular dystrophy, and intramuscular injection, there is muscle damage or breakdown, leading to an elevated level of creatine kinase. However, in hepatitis, which is inflammation of the liver, there is no direct damage to muscle tissue, so the level of creatine kinase remains within the normal range.

Acid phosphatase can be helpful in establishing the presence of seminal fluid. Acid phosphatase is an enzyme that is found in high concentrations in seminal fluid. Therefore, testing for acid phosphatase can indicate the presence of seminal fluid, which can be useful in forensic investigations, sexual assault cases, or determining fertility. Lactic dehydrogenase and isocitrate dehydrogenase are not specific to seminal fluid and may not provide accurate results. Alkaline phosphatase is found in various tissues and fluids in the body, so it is not specific to seminal fluid either.

Total prostate-specific antigen (PSA) is useful in the detection and management of carcinoma of the prostate. PSA is a protein produced by the prostate gland, and elevated levels of PSA in the blood can indicate the presence of prostate cancer. PSA testing is commonly used as a screening tool for prostate cancer, and it can also be used to monitor the effectiveness of treatment and detect recurrence. However, it is important to note that elevated PSA levels can also be caused by non-cancerous conditions such as benign prostatic hyperplasia (BPH), so further diagnostic tests are usually required to confirm a prostate cancer diagnosis.

CA 125 is a tumor marker that is primarily associated with ovarian and endometrial carcinoma. This means that elevated levels of CA 125 in the blood can indicate the presence of these types of cancer. While breast carcinoma, colon cancer, and lung cancer are all types of cancer, CA 125 is not typically used as a marker for these specific types. Therefore, the correct answer is ovarian and endometrial carcinoma.

not-available-via-ai

Storing the specimen protected from light until the analysis is done does not eliminate erroneous ammonia levels. Light exposure does not have an impact on ammonia levels, so storing the specimen in a light-protected environment will not affect the accuracy of the test results. The other options listed, such as assuring ammonia-free water and reagents, separating plasma from cells, and keeping the specimen chilled, are effective methods for eliminating erroneous ammonia levels.

Hemoglobin S and hemoglobin D can be separated by electrophoresis on a different medium and acidic pH. Electrophoresis is a technique that separates molecules based on their charge and size. By using a different medium and adjusting the pH to be acidic, the hemoglobin molecules will migrate at different rates, allowing for their separation. This method takes advantage of the different properties of hemoglobin S and hemoglobin D to distinguish between them.

Cholesterol is the common substrate used in the biosynthesis of adrenal steroids, including androgens and estrogens. Adrenal glands convert cholesterol into various hormones through a series of enzymatic reactions. This process starts with the conversion of cholesterol into pregnenolone, which is then further metabolized to produce different adrenal steroids, including cortisol, androgens, and estrogens. Therefore, cholesterol serves as the precursor for the synthesis of these important hormones in the adrenal glands.

The given blood gas results show a low pH (7.18) and a high PCO2 (60 mm Hg), which indicates respiratory acidosis. This is commonly seen in patients with emphysema, a lung condition characterized by damage to the air sacs in the lungs. Emphysema leads to impaired gas exchange, causing an increase in carbon dioxide levels and a decrease in oxygen levels. The low pH and high PCO2 in this patient's blood gas results are consistent with the respiratory acidosis seen in emphysema.

The patient's symptoms of feeling cold all the time and recent weight gain, along with the elevated TSH level, indicate that she most likely has primary hypothyroidism. Primary hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormones, leading to a decrease in metabolism and symptoms such as feeling cold and weight gain. The elevated TSH level is a result of the body's attempt to stimulate the thyroid gland to produce more hormones. Graves disease and primary hyperthyroidism would typically present with opposite symptoms, such as feeling hot and weight loss. A TSH-secreting tumor would result in elevated TSH levels, but the symptoms described by the patient are more indicative of hypothyroidism rather than hyperthyroidism.

The first step in the quantitation of serum iron is the separation of iron from transferring. This is because in order to accurately measure the amount of iron in the serum, it needs to be separated from the protein transferring. This separation can be achieved through various methods such as centrifugation or filtration. Once the iron is separated, it can then be quantitated using methods such as colorimetry or atomic absorption spectroscopy.

Isoenzyme assays are performed to improve specificity. Isoenzymes are different forms of an enzyme that have the same function but differ in their amino acid sequence. By performing isoenzyme assays, it is possible to differentiate between different forms of the same enzyme and determine their specific activity. This helps in identifying specific enzymes and distinguishing them from other similar enzymes, thus improving the specificity of the assay.

Collecting a 24 hr urine free cortisol sample would provide an accurate assessment of potential excess cortisol production (hypercortisolism) because it measures the total amount of cortisol excreted in the urine over a 24-hour period. This method is useful for evaluating cortisol levels over a longer period of time and can help identify any abnormalities in cortisol production throughout the day. Other sample collections, such as plasma samples at specific times or after administration of metyrapone, may provide limited information and not capture the overall cortisol production accurately.

A person suspected of having metabolic alkalosis would have elevated CO2 content and pH. This is because metabolic alkalosis is a condition characterized by an increase in bicarbonate (HCO3-) levels in the blood, which leads to an increase in CO2 content. This increase in CO2 content causes a shift in the pH towards the alkaline side, resulting in an elevated pH. Therefore, the laboratory findings of elevated CO2 content and pH support the diagnosis of metabolic alkalosis.

To determine the cause of tetany, ordering a serum magnesium level is most likely. Tetany is often caused by hypomagnesemia, which is a deficiency of magnesium in the blood. Therefore, it is necessary to measure the magnesium level in addition to serum calcium to determine if low magnesium is contributing to the tetany. The other options (phosphate, sodium, and vitamin D) are not directly related to the cause of tetany and would not provide as much insight into the condition.

The protein portion of an enzyme complex is called the apoenzyme. The apoenzyme is the inactive form of the enzyme and requires the binding of a cofactor or a coenzyme to become active. The coenzyme is a non-protein organic molecule that assists in the enzyme's catalytic activity. The holoenzyme refers to the complete, active form of the enzyme, which includes both the apoenzyme and the bound cofactor or coenzyme. The proenzyme, on the other hand, is an inactive precursor of an enzyme that requires further modification or activation to become functional.

The correct answer is "of advances in electrochemistry". This is because advances in electrochemistry have allowed for the development of ion-selective electrodes, which can accurately and selectively measure the concentration of Na+ and K+ ions in a sample. This method does not require dilution like flame photometry, and it also does not suffer from lipoprotein interference. Additionally, the ion-selective electrode method does not require an internal standard, making it a more convenient and efficient technique for quantitating Na+ and K+ ions.

40%-50% of total serum calcium is nondiffusible protein bound. This means that a significant portion of calcium in the blood is bound to proteins and cannot freely move or diffuse. This protein-bound calcium plays a crucial role in various physiological processes such as blood clotting, muscle contraction, and nerve function. The remaining percentage of calcium is either ionized (free and active) or bound to other substances like citrate or phosphate.

Pernicious anemia is associated with the greatest elevation of lactate dehydrogenase isoenzyme 1. Lactate dehydrogenase is an enzyme found in many tissues, including red blood cells. Pernicious anemia is a condition characterized by a deficiency of vitamin B12, which leads to the production of abnormal red blood cells. These abnormal red blood cells are more fragile and have a shorter lifespan, leading to an increased breakdown of red blood cells and subsequent release of lactate dehydrogenase isoenzyme 1 into the bloodstream. This explains the elevated levels of lactate dehydrogenase isoenzyme 1 in pernicious anemia.

In ion-exchange chromatographic methods, falsely increased levels of Hgb A1c can be demonstrated in the presence of Hgb S. This is because Hgb S has a different charge compared to Hgb A1c, which can lead to interference in the chromatographic separation. Therefore, when analyzing Hgb A1c levels using this method, the presence of Hgb S can result in inaccurate measurements, leading to falsely increased levels.

The elevated levels of CK (creatine kinase), AST (aspartate aminotransferase), and normal levels of CKMB (creatine kinase MB) suggest muscle damage. A crush injury to the thigh can cause muscle damage, leading to the release of these enzymes into the bloodstream. This explains the abnormal laboratory results in the serum sample of the 42-year-old man.

The procedure used to detect hemolytic disease of the newborn in amniotic fluid is the measurement of absorbance at 450 nm. This is because hemolytic disease of the newborn involves the destruction of red blood cells, which leads to the release of bilirubin. The measurement of absorbance at 450 nm allows for the quantification of bilirubin levels in the amniotic fluid, which can help diagnose the condition.

During a normal pregnancy, quantitative human chorionic gonadotropin (hCG) levels peak at 8-10 weeks after the last menstrual period. This hormone is produced by the placenta and its levels increase rapidly during the early stages of pregnancy. The peak levels of hCG usually occur around the 8-10 week mark and then gradually decline as the pregnancy progresses. Monitoring hCG levels is important in confirming a viable pregnancy and can also help detect potential issues such as ectopic pregnancy or miscarriage.

Elevated lipid levels can interfere with the determination of sodium by indirect ion selective electrode. This is because lipids can bind to sodium ions and prevent them from being detected accurately by the electrode. This interference can lead to falsely decreased sodium levels.

not-available-via-ai

The correct answer is testing heparinized plasma. Heparinized plasma should be used to confirm the serum potassium (K) level in patients with myeloproliferative disorder. This is because platelet counts can be extremely high in these patients, which can lead to in vitro release of potassium from platelets during serum collection. Heparinized plasma prevents this release of potassium, providing a more accurate measurement of the patient's true serum potassium level. Repeat testing of the original serum or testing freshly drawn serum may still be affected by platelet release of potassium, while atomic absorption spectrometry is not necessary for confirming the serum K level in this case.

The sweat chloride result of 55 mEq/L and sweat sodium of 52 mEq/L fall within a borderline range, suggesting that further testing is necessary. The abnormal chloride test should be repeated to confirm the results and ensure accuracy.

To calculate the gamma globulin content in g/dL, we can use the formula:

Gamma globulin content (g/dL) = (gamma globulin area / total area) * total protein

Plugging in the given values, we get:

Gamma globulin content (g/dL) = (30 units / 180 units) * 6.5 g/dL
= 0.1667 * 6.5 g/dL
= 1.0833 g/dL

Rounding to one decimal place, the gamma globulin content is approximately 1.1 g/dL or 11 g/L.

A diagnosis of primary adrenal insufficiency requires an impaired response to ACTH stimulation. This means that when ACTH is administered to stimulate the adrenal glands to produce cortisol, there is a lack of or inadequate response. This is indicative of dysfunction or damage to the adrenal glands, leading to decreased cortisol production. The other options mentioned, such as decreased urinary 17-keto and 17-hydroxysteroids and increased urinary cortisol excretion after metyrapone, may be seen in different conditions but are not specific to primary adrenal insufficiency.

A patient with metabolic alkalosis would have an increased bicarbonate (HCO3) level and a high total carbon dioxide (TCO2) level. This is because metabolic alkalosis is characterized by an excess of bicarbonate in the blood, which leads to an increase in TCO2. The increased HCO3 and TCO2 levels indicate an imbalance in the body's acid-base balance, resulting in alkalosis.

The marked increase in alkaline phosphatase and the slight increase in aspartate amino transferase, alanine amino transferase, and gamma-glutamyl transferase suggest a pattern consistent with obstructive jaundice. In obstructive jaundice, there is a blockage or obstruction of the bile ducts, leading to impaired bile flow. This can result in elevated levels of liver enzymes, such as alkaline phosphatase, as well as slight increases in other liver function tests. Acute hepatitis would typically present with more significant increases in liver enzymes, while chronic hepatitis may show a more prolonged elevation. Osteitis fibrosa is unrelated to the liver and would not cause these specific enzyme changes.

Osmolarity is a measure of the concentration of solutes in a solution. In the context of evaluating renal tubular function, osmolarity can provide information about the ability of the kidneys to regulate water and electrolyte balance. It can help determine if the kidneys are properly concentrating or diluting the urine. By measuring the osmolarity of urine, healthcare professionals can assess the functioning of the renal tubules and identify any abnormalities or disorders affecting the kidneys' ability to regulate fluid and electrolyte balance. Therefore, osmolarity is a suitable test for evaluating renal tubular function.

Alpha-fetoprotein (AFP) is a substance that is produced by certain types of cancer cells, including testicular cancer. Monitoring the levels of AFP in a patient's blood can be useful in tracking the progress of testicular cancer and determining the effectiveness of treatment. Elevated levels of AFP may indicate the presence of cancer or the recurrence of cancer after treatment. Therefore, monitoring AFP levels can help healthcare professionals assess the course of a patient's testicular cancer and make informed decisions regarding their treatment plan.

In respiratory acidosis, the body is unable to remove enough carbon dioxide from the lungs, leading to an increase in blood PCO2 levels. As a compensatory mechanism, the kidneys increase the reabsorption and production of bicarbonate ions, which helps to neutralize the excess acid in the blood. This increase in plasma bicarbonate concentration helps to restore the acid-base balance in the body. Therefore, the correct answer is plasma bicarbonate concentration.

Triiodothyronine (T3) is the more biologically active hormone that is derived from thyroxine (T4). T4 is converted into T3 in various tissues, including the liver, kidney, and thyroid gland. T3 is responsible for regulating metabolism, growth, and development in the body. It binds to specific receptors in target cells and initiates gene transcription, leading to various physiological effects. Therefore, the majority of T4 is converted into T3 to exert its biological actions in the body.

The urine to serum osmolality ratio is a measure of the concentration of solutes in the urine compared to the concentration in the blood. This ratio indicates how well the kidney is able to concentrate the glomerular filtrate. If the ratio is high, it means that the kidney is effectively reabsorbing water and concentrating the urine. On the other hand, if the ratio is low, it suggests that the kidney is not able to concentrate the urine properly. Therefore, the urine to serum osmolality ratio is a useful indicator of the kidney's ability to concentrate the glomerular filtrate.

The most heat labile fraction of alkaline phosphatase is obtained from bone. Heat lability refers to the sensitivity of a substance to heat, and in this case, it suggests that the alkaline phosphatase derived from bone is easily denatured or inactivated when exposed to high temperatures. This implies that the alkaline phosphatase obtained from bone is less stable compared to the fractions obtained from liver, intestine, or placenta.

not-available-via-ai

Hemoglobin C is the slowest migrating hemoglobin on electrophoresis at alkaline pH. This is because hemoglobin C has a different charge compared to the other hemoglobins listed. The migration of hemoglobin during electrophoresis is influenced by the charge and size of the molecule. Hemoglobin C has a different amino acid substitution in its beta chain, resulting in a different charge distribution. This difference in charge causes hemoglobin C to migrate more slowly compared to the other hemoglobins on electrophoresis at alkaline pH.

The correct answer is hemolytic anemia. Hemolytic anemia is a condition characterized by the destruction of red blood cells, leading to an increased release of lactic dehydrogenase (LDH) into the bloodstream. LDH is an enzyme found in various tissues, including red blood cells, and its activity can be measured to assess tissue damage. In hemolytic anemia, the destruction of red blood cells causes an elevation of the fast fractions (1 and 2) on electrophoretic separation, indicating increased LDH activity. This is why hemolytic anemia is the likely cause of the increased serum LDH activity in this scenario.

Elevations of lactate dehydrogenase (LDH) isoenzymes 4 and 5 on electrophoresis are most commonly associated with liver disease. LDH is an enzyme found in many tissues, including the liver. In liver disease, such as hepatitis or cirrhosis, there is damage to liver cells, leading to the release of LDH into the bloodstream. This can result in elevated levels of LDH isoenzymes 4 and 5 on electrophoresis. Hemolytic anemia, myocardial infarction, and pulmonary edema may also cause elevations in LDH, but liver disease is most often associated with the specific isoenzymes mentioned.

The regan isoenzyme shares the same properties as alkaline phosphatase, and it is primarily found in the placenta.