Clinical Chemistry
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Questions and Answers

Which hormone is primarily responsible for stimulating gluconeogenesis?

  • Insulin
  • Glucagon
  • Cortisol (correct)
  • Epinephrine

    • What is the primary effect of human placental lactogen on glucose levels?

  • Insulin antagonism (correct)
  • Promotion of glycogen synthesis
  • Inhibition of glycemic decline
  • Insulin production stimulation

    • Which of the following hormones is NOT associated with an increase in serum glucose?

  • T3 & T4
  • Insulin (correct)
  • Epinephrine
  • Growth Hormone

    • In which condition does a tumor of the adrenal medulla typically lead to hyperglycemia?

    <p>Pheochromocytoma</p> Signup and view all the answers

    What condition describes the combination of high glucose in both serum and urine tests?

    <p>Diabetic Acidosis</p> Signup and view all the answers

    Which of the following symptoms is NOT typically associated with hyperglycemia?

    <p>Weight gain</p> Signup and view all the answers

    Which hormone is involved in stimulating glycogenolysis?

    <p>Epinephrine</p> Signup and view all the answers

    Acromegaly is associated with which of the following metabolic changes?

    <p>Hyperglycemia</p> Signup and view all the answers

    Which hormone is primarily responsible for stimulating glucose uptake by cells?

    <p>Insulin</p> Signup and view all the answers

    What is the effect of sodium fluoride as an anticoagulant in serum samples?

    <p>Slows glycolysis</p> Signup and view all the answers

    What is the fasting reference range for serum or plasma glucose levels?

    <p>70-99 mg/dL</p> Signup and view all the answers

    Arterial and capillary glucose values are typically how much higher than venous values?

    <p>2-3 mg/dL</p> Signup and view all the answers

    Which hormone is known as an insulin antagonist?

    <p>ACTH</p> Signup and view all the answers

    How do normal cerebrospinal fluid (CSF) glucose levels compare to plasma glucose levels?

    <p>CSF levels are two-thirds of plasma levels</p> Signup and view all the answers

    What role does glucagon play in serum glucose levels?

    <p>Stimulates glycogenolysis</p> Signup and view all the answers

    Which hormone is secreted by the anterior pituitary and increases serum glucose levels?

    <p>ACTH</p> Signup and view all the answers

    What condition is associated with elevated alpha-2-globulins?

    <p>Chronic inflammation</p> Signup and view all the answers

    Which substance is a carrier protein for copper in the bloodstream?

    <p>Ceruloplasmin</p> Signup and view all the answers

    In which condition would you expect haptoglobin levels to decrease?

    <p>Hemolysis</p> Signup and view all the answers

    What is a common finding in the liver disease related to alpha-2-globulins?

    <p>Elevation of beta globulins</p> Signup and view all the answers

    What is the primary function of albumin in the blood?

    <p>Regulating osmotic pressure</p> Signup and view all the answers

    Which of the following would NOT increase ceruloplasmin levels?

    <p>Wilson's disease</p> Signup and view all the answers

    Which condition is related to decreased levels of haptoglobin?

    <p>Nephrotic syndrome</p> Signup and view all the answers

    What type of proteins are beta globulins primarily known for transporting?

    <p>Iron and lipids</p> Signup and view all the answers

    Which dye is NOT used in dye-binding methods for albumin?

    <p>Phenolphthalein</p> Signup and view all the answers

    What clinical significance do prealbumin levels have?

    <p>Assessment of nutritional status</p> Signup and view all the answers

    In serum protein electrophoresis, which protein fraction has the largest proportion?

    <p>Albumin</p> Signup and view all the answers

    What happens to proteins at a pH higher than their isoelectric point during electrophoresis?

    <p>Become negatively charged and migrate toward the anode</p> Signup and view all the answers

    Which protein is primarily produced by the liver?

    <p>Albumin</p> Signup and view all the answers

    Which of the following methods is NOT used for measuring specific serum proteins?

    <p>Visual comparative methods</p> Signup and view all the answers

    Which of the following proteins serves as a transport protein due to its ease of binding with blood components?

    <p>Albumin</p> Signup and view all the answers

    What is an expected outcome of liver impairment in terms of serum proteins?

    <p>Decreased synthesis of albumin</p> Signup and view all the answers

    What is the significance of branched chain ketoaciduria in relation to diabetes mellitus?

    <p>It involves branched chain amino acids in blood and urine.</p> Signup and view all the answers

    In normal test conditions, what fasting plasma glucose level corresponds to a normal diagnosis?

    <p>Between 70 and 100 mg/dL</p> Signup and view all the answers

    Which of the following best describes the interpretation of a casual plasma glucose test?

    <p>Results should be evaluated in conjunction with A1c measurements.</p> Signup and view all the answers

    What component is measured to calculate LDL and VLDL as part of lipid analysis?

    <p>Lipid levels in plasma</p> Signup and view all the answers

    What is cystinuria primarily characterized by in a urine analysis?

    <p>Presence of cystine and specific amino acids.</p> Signup and view all the answers

    What change is observed in renal function during branched chain ketoaciduria conditions?

    <p>Decreased renal threshold or reabsorption.</p> Signup and view all the answers

    Which test is part of the oral glucose tolerance test (OGTT) procedure?

    <p>Fasting plasma glucose level determination.</p> Signup and view all the answers

    What is the threshold fasting plasma glucose level for diagnosing diabetes mellitus?

    <p>126 mg/dL</p> Signup and view all the answers

    What condition is indicated by highly elevated alkaline phosphatase (ALP) and gamma-glutamyl transferase (G) levels?

    <p>Biliary obstruction</p> Signup and view all the answers

    Which method is NOT commonly used to measure fatty acids in cases of suspected pancreatitis?

    <p>Immunoassay for prostatic ACP</p> Signup and view all the answers

    Why is lipase considered more specific for acute pancreatitis compared to amylase?

    <p>It remains elevated longer than amylase.</p> Signup and view all the answers

    What impact does hemolysis have on specimen collection for serum tests?

    <p>It can result in falsely elevated results.</p> Signup and view all the answers

    In the context of pancreatic disorders, what is the significance of using a tartrate buffer with lipase measurements?

    <p>It inhibits prostatic acid phosphatase.</p> Signup and view all the answers

    Which of the following represents a more ancient method of measuring lipase activity?

    <p>Olive oil substrate method</p> Signup and view all the answers

    Which enzyme has the highest levels in biliary obstruction and is often elevated after alcohol intake?

    <p>GGT</p> Signup and view all the answers

    Which enzyme is primarily produced in the liver and is a key marker for hepatocellular damage?

    <p>ALT</p> Signup and view all the answers

    Which enzyme's activity is aligned with an optimum pH of 10 and is activated by magnesium?

    <p>ALP</p> Signup and view all the answers

    Which enzyme specifically indicates liver disease and shows activities separate from bone disease when tested?

    <p>5'NT</p> Signup and view all the answers

    Which method is used for measuring alkaline phosphatase activity?

    <p>Spectrophotometric method</p> Signup and view all the answers

    What is the primary significance of elevated total CK levels in a clinical setting?

    <p>Suggests muscle or cardiac injury</p> Signup and view all the answers

    Which enzyme would most likely be elevated during muscle trauma or renal infarct?

    <p>ALT</p> Signup and view all the answers

    Which CK isoenzyme is primarily associated with cardiac muscle damage?

    <p>CK-MB</p> Signup and view all the answers

    In patients with obesity and liver dysfunction, which enzyme is most indicative of hepatic cell injury?

    <p>ALT</p> Signup and view all the answers

    How does the sex of a patient influence CK reference ranges?

    <p>Males typically have higher CK levels due to greater muscle mass</p> Signup and view all the answers

    Which substrate is utilized in the spectrophotometric measurement of GGT?

    <p>Gamma-glutamyl-p-nitroanilide</p> Signup and view all the answers

    Which factor does NOT significantly affect enzyme activity in laboratory measurements?

    <p>Presence of protective gloves</p> Signup and view all the answers

    What are the two subunits that make up the CK isoenzymes?

    <p>M and B</p> Signup and view all the answers

    What is the effect of a shift in temperature on enzyme reactions?

    <p>Doubles the reaction rate with every 10 degrees increase</p> Signup and view all the answers

    Which CK isoenzyme is primarily associated with skeletal muscle?

    <p>CK-MM</p> Signup and view all the answers

    Which conclusion can be drawn regarding trauma to skeletal muscle?

    <p>It leads to an increase in total CK but not CK-MB</p> Signup and view all the answers

    What is the primary source of acid phosphatase in the human body?

    <p>Prostate</p> Signup and view all the answers

    In which condition would you expect to see the highest elevations of acid phosphatase?

    <p>Metastasizing carcinoma of the prostate</p> Signup and view all the answers

    What is the primary clinical significance of increased cholinesterase levels?

    <p>Severe neuromuscular effects</p> Signup and view all the answers

    Which enzyme is known to be clinically significant in the context of organophosphate poisoning?

    <p>Cholinesterase</p> Signup and view all the answers

    What is the effect of serum storage at room temperature on enzyme activity?

    <p>Results in loss of enzyme activity</p> Signup and view all the answers

    Which condition is associated with elevated levels of tartrate-resistant acid phosphatase?

    <p>Hairy cell leukemia</p> Signup and view all the answers

    What happens when serum must be stabilized after removal from cells?

    <p>Disodium citrate is added</p> Signup and view all the answers

    What is an implication of the clinical use of PSA in relation to acid phosphatase?

    <p>It has replaced acid phosphatase for prostate cancer diagnosis</p> Signup and view all the answers

    What is the primary mechanism of a noncompetitive inhibitor in enzyme reactions?

    <p>Binds to a site other than the active site</p> Signup and view all the answers

    Which of the following best describes zero-order kinetics?

    <p>The reaction rate is constant regardless of substrate concentration</p> Signup and view all the answers

    What does the measurement of LD activity through the spectrophotometric method primarily rely on?

    <p>The decrease in absorbance of NADH at 340 nm</p> Signup and view all the answers

    How many forms of Lactate Dehydrogenase (LD) isoenzymes are known to be tissue-specific?

    <p>5 forms</p> Signup and view all the answers

    In the context of enzyme inhibition, what characteristic differentiates uncompetitive inhibitors from other types?

    <p>They only bind to the enzyme-substrate complex</p> Signup and view all the answers

    What is indicated by a high activity of lactate dehydrogenase in serum?

    <p>Myocardial infarction or muscle trauma</p> Signup and view all the answers

    Which factors can lead to sources of error in measuring enzyme levels in serum samples?

    <p>Both A and B</p> Signup and view all the answers

    What defines the catalytic activity of an enzyme as measured in international units (U or JU)?

    <p>Amount of enzyme that converts 1 µM of substrate per minute</p> Signup and view all the answers

    What clinical significance is associated with the presence of acetylcholinesterase in plasma?

    <p>Elevated levels indicate prostate carcinoma.</p> Signup and view all the answers

    Which method is used for measuring total alkaline phosphatase (ACP)?

    <p>Colorimetric method using nitrophenyl phosphate.</p> Signup and view all the answers

    Severe deficiencies of which enzyme result in serious neuromuscular effects and indicate clinical significance?

    <p>Erythrocyte acetylcholinesterase.</p> Signup and view all the answers

    What is the primary function of plasma pseudocholinesterase?

    <p>Destroys acetylcholine after nerve impulse transmission.</p> Signup and view all the answers

    What is the primary timeframe for BNP medication to peak after administration?

    <p>4-10 hours</p> Signup and view all the answers

    In which condition is tartrate-resistant alkaline phosphatase particularly elevated?

    <p>Hairy cell leukemia.</p> Signup and view all the answers

    Which marker is considered the single best test for diagnosing acute myocardial infarction (AMI)?

    <p>Troponin</p> Signup and view all the answers

    Which enzyme rises quickly after acute myocardial infarction (AMI)?

    <p>Myoglobin.</p> Signup and view all the answers

    What is the primary limitation of using NT pro-BNP in diagnosing AMI?

    <p>It can also be elevated in kidney disease.</p> Signup and view all the answers

    How long does it typically take for troponin levels to return to normal after an AMI event?

    <p>2-3 days</p> Signup and view all the answers

    What characteristic of prostatic acid phosphatase makes it useful in clinical diagnostics?

    <p>Uses specific substrates for measurement.</p> Signup and view all the answers

    What clinical application is associated with measuring cardiac markers?

    <p>Evaluating potential acute myocardial infarction.</p> Signup and view all the answers

    What does an absence of troponin indicate regarding AMI?

    <p>It rules out myocardial damage.</p> Signup and view all the answers

    What identifies CK2 (CK-MB) in relation to AMI?

    <p>Rises within 4-6 hours after AMI onset.</p> Signup and view all the answers

    Which risk assessment marker is sensitive to chronic inflammation?

    <p>hsCRP</p> Signup and view all the answers

    What are the components of the troponin complex?

    <p>Troponin T, troponin I, and troponin C</p> Signup and view all the answers

    What is the main advantage of using lipase over amylase in diagnosing acute pancreatitis?

    <p>Lipase remains elevated for a longer period following acute pancreatitis.</p> Signup and view all the answers

    What is a critical factor to consider during specimen handling for acid phosphatase determination?

    <p>Hemolysis must be avoided as it can lead to falsely negative results.</p> Signup and view all the answers

    Which method is considered a more traditional approach to measuring lipase activity?

    <p>Olive oil substrate to measure fatty acids production.</p> Signup and view all the answers

    In the context of lipase measurements, why is a tartrate buffer added?

    <p>To inhibit the activity of prostatic acid phosphatase.</p> Signup and view all the answers

    What factor significantly impacts enzyme activity in specimens for analysis?

    <p>The time taken to process the sample after collection.</p> Signup and view all the answers

    Which characteristic makes acid phosphatase levels more significant in the clinical setting?

    <p>Erythrocytes contribute a substantial amount to the total levels.</p> Signup and view all the answers

    What is a potential consequence of improper storage conditions for serum samples?

    <p>Loss of enzyme activity requiring re-extraction of serum.</p> Signup and view all the answers

    What role does disodium citrate play in serum handling?

    <p>It acts as a stabilizer to enhance enzyme activity.</p> Signup and view all the answers

    What is the typical time frame for the peak elevation of liver markers after an acute myocardial infarction (AMI)?

    <p>12-14 hours</p> Signup and view all the answers

    Which liver enzyme is liver-specific and often elevated in cases of biliary obstruction?

    <p>GGT</p> Signup and view all the answers

    What effect does the release of B-type Natriuretic Peptide (BNP) have on blood pressure?

    <p>Decreases blood pressure by promoting vasodilation</p> Signup and view all the answers

    Which cardiac marker is correlated with the classification stages of congestive heart failure (CHF)?

    <p>B-type Natriuretic Peptide (BNP)</p> Signup and view all the answers

    Which enzyme among those listed is associated with the highest values in liver-specific damage?

    <p>ALT</p> Signup and view all the answers

    What role does ANP (Atrial Natriuretic Peptide) play in relation to the renin-angiotensin-aldosterone system (RAAS)?

    <p>It acts as an antagonist to RAAS</p> Signup and view all the answers

    Which enzymatic activity is linked to elevated levels specifically indicating biliary obstruction and is affected by alcohol consumption?

    <p>GGT</p> Signup and view all the answers

    Which marker is cleaved from pre-pro-BNP and is recognized as an inactive form?

    <p>N-Terminal pro-BNP (NT pro-BNP)</p> Signup and view all the answers

    What is the formula for calculating osmolality that includes glucose and BUN?

    <p>Calculated Osmolality = 2Na + Glucose + BUN</p> Signup and view all the answers

    Which of the following is NOT considered a major unmeasured cation?

    <p>Sodium</p> Signup and view all the answers

    What does a measured osmolality that is greater than 10 higher than calculated osmolality suggest?

    <p>Presence of exogenous unmeasured anions</p> Signup and view all the answers

    How is the anion gap calculated without including potassium (K+)?

    <p>(Na+) - [(Cr) + (HC03)]</p> Signup and view all the answers

    What is the reference range for the anion gap when using the equation that includes K+?

    <p>10-20 mM/L</p> Signup and view all the answers

    Which of the following is a major unmeasured anion?

    <p>Albumin</p> Signup and view all the answers

    What analytical method is notably referenced for measuring electrolyte concentrations?

    <p>Atomic absorption spectroscopy</p> Signup and view all the answers

    What condition could potentially cause abnormal gaps for multiple patients in electrolyte measurements?

    <p>Presence of exogenous unmeasured anions</p> Signup and view all the answers

    What signifies a high anion gap in blood analysis?

    <p>High serum Mg++</p> Signup and view all the answers

    Which method is considered the most precise for measuring osmolality?

    <p>Freezing point depression</p> Signup and view all the answers

    What is the primary component reflected in the total CO2 measurement?

    <p>Bicarbonate (HCO3)</p> Signup and view all the answers

    In the context of chloride shift, which condition is characterized by a loss of albumin?

    <p>Low pH</p> Signup and view all the answers

    Which statement accurately describes an anion gap calculation?

    <p>It reflects differences in unmeasured cations and anions.</p> Signup and view all the answers

    Which factor is considered a practical method for assessing osmolality?

    <p>Vapor pressure depression</p> Signup and view all the answers

    What effect does lithium therapy typically have on serum magnesium levels?

    <p>Increase serum Mg++</p> Signup and view all the answers

    The bicarbonate levels in blood can be assessed through which of the following methods?

    <p>Multiple methods including volumetric and colorimetric</p> Signup and view all the answers

    What is the primary effect of Vitamin D on calcium levels in the body?

    <p>Increases calcium absorption in the intestines</p> Signup and view all the answers

    In cases of hypercalcemia, which of the following conditions is most likely to contribute to muscle weakness?

    <p>Hyperparathyroidism</p> Signup and view all the answers

    What is the relationship between phosphate (PO4) and calcium (Ca++) levels in the body?

    <p>When calcium decreases, phosphate increases</p> Signup and view all the answers

    What is the physiological effect of hypocalcemia on muscle activity?

    <p>Tetany and increased muscle excitability</p> Signup and view all the answers

    Which hormone primarily works to decrease blood calcium levels by inhibiting bone reabsorption?

    <p>Calcitonin</p> Signup and view all the answers

    In which condition can excessive vitamin D lead to elevated phosphate levels?

    <p>Hypervitaminosis D</p> Signup and view all the answers

    Which of the following is a potential cause of hypocalcemia?

    <p>Malabsorption of vitamin D</p> Signup and view all the answers

    What is the primary laboratory measurement for assessing phosphate levels in the body?

    <p>Inorganic phosphorus (PO4)</p> Signup and view all the answers

    Which of the following best describes the primary function of the colorimetric method in measuring calcium levels?

    <p>It utilizes a specific dye to create a colored complex based on calcium concentration.</p> Signup and view all the answers

    What is a significant concern when using ethylenediaminetetraacetic acid (EDTA) for calcium measurements?

    <p>It binds to calcium, leading to a potential underestimation of calcium levels.</p> Signup and view all the answers

    Which condition could complicate calcium measurements due to its effects on calcium regulation?

    <p>Diabetic ketoacidosis</p> Signup and view all the answers

    When collecting a sample to measure ionized calcium, what method is recommended to ensure accuracy?

    <p>Collection anaerobically to prevent CO2 loss and pH changes.</p> Signup and view all the answers

    Which method is least likely to be effective for accurately measuring total calcium levels?

    <p>Direct gravimetric analysis</p> Signup and view all the answers

    What role does 8-hydroxyquinoline play in calcium measurement?

    <p>It removes interfering magnesium ions from the sample.</p> Signup and view all the answers

    Which of the following factors could lead to falsely lower calcium measurements in a clinical sample?

    <p>Use of oxalate as an anticoagulant</p> Signup and view all the answers

    How does renal failure primarily affect the measurement of calcium levels?

    <p>It can lead to a decrease in both total and ionized calcium levels.</p> Signup and view all the answers

    What role does molybdate play in spectrophotometric methods for measuring phosphates?

    <p>It combines with PO4 ions to form phosphomolybdate.</p> Signup and view all the answers

    Which statement accurately describes the forms of Vitamin D?

    <p>D3 is primarily produced through photosynthesis in skin.</p> Signup and view all the answers

    What indicates that abnormal PTH producing tissue has been successfully removed during surgery?

    <p>A 50% decline in PTH from baseline at 5 minutes post-excision.</p> Signup and view all the answers

    What is a function of the active dihydroxy form of Vitamin D?

    <p>It regulates calcium and phosphorus levels in the body.</p> Signup and view all the answers

    Which of the following best describes the metabolism process of both forms of Vitamin D?

    <p>Both forms require hydroxylation to become active dihydroxy variants.</p> Signup and view all the answers

    What is the key difference between forms D2 and D3 of Vitamin D?

    <p>D3 is derived from exposure to sunlight.</p> Signup and view all the answers

    What observation would suggest impaired renal reabsorption of phosphate?

    <p>Elevated concentrations of phosphate in urine.</p> Signup and view all the answers

    In what context is intraoperative PTH monitoring most beneficial?

    <p>Identifying parathyroid tissue during surgical removal.</p> Signup and view all the answers

    Which condition is commonly associated with respiratory alkalosis?

    <p>Hyperventilation</p> Signup and view all the answers

    What does a decrease in pCO2 primarily indicate in blood gas readings?

    <p>Respiratory alkalosis</p> Signup and view all the answers

    In evaluating acid-base disorders, what is indicated by pCO2 moving in the opposite direction to pH?

    <p>Respiratory compensation</p> Signup and view all the answers

    Which of the following accurately reflects the normal range for bicarbonate (HCO3) in blood gas analysis?

    <p>22-26 mM/L</p> Signup and view all the answers

    What physiological mechanism primarily compensates for respiratory alkalosis?

    <p>Increased H+ excretion</p> Signup and view all the answers

    What is typically the relationship between pH and metabolic disorders in blood analysis?

    <p>Both pH and HCO3 will rise together</p> Signup and view all the answers

    Which blood gas parameter is directly impacted by the partial pressure of carbon dioxide (pCO2)?

    <p>Blood pH</p> Signup and view all the answers

    What does a normal arterial blood gas pH reading indicate?

    <p>Complete metabolic compensation</p> Signup and view all the answers

    What is likely to happen to pO2 when exposure to air occurs?

    <p>Increase in pO2</p> Signup and view all the answers

    Which of the following describes the process related to prolonged sitting impacting pC02 levels?

    <p>Prolonged sitting raises pC02 levels</p> Signup and view all the answers

    Which mechanism is involved in the compensatory response to respiratory acidosis?

    <p>Increase in HCO3</p> Signup and view all the answers

    What is the role of the lung in compensating for metabolic alkalosis?

    <p>Increase in pC02</p> Signup and view all the answers

    In the playful analogy provided, who exhibits changes in pH during the seesaw activity?

    <p>Phonctia and Paco</p> Signup and view all the answers

    Which of the following states occurs during conditions of metabolic acidosis?

    <p>Increase in pC02 levels</p> Signup and view all the answers

    What best illustrates the relationship between respiratory and metabolic acid-base status?

    <p>They can influence each other</p> Signup and view all the answers

    What condition should be selected if conjugated bilirubin is on the low side of normal?

    <p>Metabolic acidosis</p> Signup and view all the answers

    Which of the following methods uses caffeine-benzoate as an accelerator?

    <p>Jendrassik-Grof method</p> Signup and view all the answers

    What characterizes indirect bilirubin?

    <p>Unconjugated and relatively insoluble in water</p> Signup and view all the answers

    How should fully compensated metabolic alkalosis be distinguished from respiratory acidosis?

    <p>Completely compensated respiratory acidosis cannot be distinguished from fully compensated metabolic alkalosis</p> Signup and view all the answers

    Which of the following statements is true regarding diazo reagent interaction?

    <p>It interacts rapidly with conjugated bilirubin</p> Signup and view all the answers

    Which statement correctly reflects the utility of the Phonetia, Paco, and Carbo story in acid-base problems?

    <p>It provides solutions for over 90% of acid-base problems</p> Signup and view all the answers

    What happens to pCO2 and CO2 levels if blood is exposed to air during collection?

    <p>They both decrease</p> Signup and view all the answers

    Which of the following conditions is a common cause of metabolic alkalosis?

    <p>Prolonged vomiting</p> Signup and view all the answers

    What is the primary anticoagulant used for collecting samples intended for blood gas studies?

    <p>Sodium heparinate</p> Signup and view all the answers

    Which compensatory mechanism primarily addresses metabolic alkalosis?

    <p>Hypoventilation</p> Signup and view all the answers

    What should be done if testing of blood samples is delayed beyond 15 minutes?

    <p>Place in cracked ice</p> Signup and view all the answers

    Which substance is often referred to when discussing bicarbonate ion (HCO3) excess?

    <p>NaHCO3</p> Signup and view all the answers

    What is the consequence of using citrate as an anticoagulant during blood transfusions?

    <p>May lead to metabolic alkalosis</p> Signup and view all the answers

    Which electrolyte imbalance is commonly associated with metabolic alkalosis?

    <p>Hypomagnesemia</p> Signup and view all the answers

    What is the primary condition characterized by pH and pCO2 being in opposite directions from normal?

    <p>Respiratory Acidosis</p> Signup and view all the answers

    In terms of pH levels, how is alkalosis defined?

    <p>pH &gt; 7.45</p> Signup and view all the answers

    Which situation results in both pH and HCO3 either increasing or decreasing together?

    <p>Metabolic Compensation</p> Signup and view all the answers

    During compensation in respiratory acidosis, what happens to pH and pCO2 levels?

    <p>pH goes down, pCO2 goes up</p> Signup and view all the answers

    Which of the following represents a status where pH and HCO3 are both higher than normal?

    <p>Alkalosis</p> Signup and view all the answers

    In the context of acid-base balance, what does compensation signify?

    <p>Adjustments in pH and HCO3 to counteract pH changes</p> Signup and view all the answers

    What occurs when the pH is below 7.35?

    <p>Metabolic Acidosis</p> Signup and view all the answers

    In respiratory compensation, what happens to HCO3 when the body attempts to correct low pH?

    <p>HCO3 decreases</p> Signup and view all the answers

    What characteristic distinguishes direct bilirubin from indirect bilirubin?

    <p>Direct bilirubin is water soluble.</p> Signup and view all the answers

    Which factor could potentially interfere with bilirubin measurement in specimens?

    <p>Light exposure to samples.</p> Signup and view all the answers

    In which scenario of acid-base balance can fully compensated metabolic alkalosis not be distinguished from another condition?

    <p>Fully compensated respiratory acidosis.</p> Signup and view all the answers

    What is the primary method used for measuring bilirubin levels in newborns, considering the challenges posed by interfering compounds?

    <p>Jendrassik-Grof method.</p> Signup and view all the answers

    What is the effect of using caffeine benzoate in the bilirubin measurement process?

    <p>It accelerates the reaction rate.</p> Signup and view all the answers

    For which type of jaundice is urobilinogen level commonly decreased due to the obstruction?

    <p>Posthepatic jaundice.</p> Signup and view all the answers

    How does the condition of lipemia affect bilirubin test results?

    <p>It can falsely elevate results.</p> Signup and view all the answers

    Which of the following accurately describes indirect bilirubin?

    <p>It is unconjugated and relatively insoluble.</p> Signup and view all the answers

    What is the appearance of urine urobilinogen when unconjugated bilirubin is elevated?

    <p>Increased</p> Signup and view all the answers

    In hepatic jaundice, what change is typically observed in urine bilirubin levels?

    <p>Increased bilirubin</p> Signup and view all the answers

    What type of bilirubin increase is associated with pre-hepatic jaundice due to hemolytic anemia?

    <p>Unconjugated bilirubin</p> Signup and view all the answers

    Which test is part of maternal serum prenatal testing used to detect neural tube defects?

    <p>Alpha-fetoprotein (AFP)</p> Signup and view all the answers

    What condition is indicated by normal liver function yet elevated unconjugated bilirubin levels?

    <p>Pre-hepatic jaundice</p> Signup and view all the answers

    In what condition would you expect to find conjugated bilirubin in the urine?

    <p>Viral hepatitis</p> Signup and view all the answers

    Which of the following is a characteristic finding in liver dysfunction related to bilirubin metabolism?

    <p>Increased conjugated bilirubin in blood</p> Signup and view all the answers

    What laboratory marker is often a part of the triple or quad test for prenatal screening?

    <p>Inhibin A</p> Signup and view all the answers

    What is the acid-base status indicated by a pH of 7.24, pCO2 of 44, and HCO3 of 18?

    <p>Metabolic Acidosis</p> Signup and view all the answers

    What conclusion can be drawn from a blood sample that shows a pH of 7.52, pCO2 of 44, and HCO3 of 39?

    <p>Metabolic Alkalosis</p> Signup and view all the answers

    Which characteristic feature is observed in urines containing large amounts of porphyrins?

    <p>Red or 'port wine' color</p> Signup and view all the answers

    What is a reliable method for quantifying porphyrins and related compounds?

    <p>Ion-exchange Chromatography</p> Signup and view all the answers

    In which test does Porphobilinogen (PBG) react with Ehrlich's reagent to form a red color?

    <p>Watson-Schwartz Test</p> Signup and view all the answers

    What level of pH indicates metabolic acidosis in blood gas analysis?

    <p>pH &lt; 7.35</p> Signup and view all the answers

    What does a pCO2 of 56 indicate when assessed with a low pH?

    <p>Respiratory acidosis</p> Signup and view all the answers

    How can porphyrins be visualized in laboratory analysis?

    <p>Using a UV spectrophotometer</p> Signup and view all the answers

    What is the expected urobilinogen level in a patient with posthepatic jaundice?

    <p>Decreased urobilinogen</p> Signup and view all the answers

    In hepatic diseases associated with cirrhosis, what type of bilirubin is likely to be elevated?

    <p>Both unconjugated and conjugated bilirubin</p> Signup and view all the answers

    Which condition is indicated by the presence of increased unconjugated bilirubin with normal levels of conjugated bilirubin in serum?

    <p>Prehepatic jaundice</p> Signup and view all the answers

    What does a negative fetal fibronectin test indicate regarding preterm delivery?

    <p>Preterm delivery will not occur</p> Signup and view all the answers

    What is the relationship between urobilinogen levels and hepatic disease?

    <p>Urobilinogen levels can be increased or decreased depending on the type of hepatic disease</p> Signup and view all the answers

    Which type of jaundice is characterized by an absence of urobilinogen in urine?

    <p>Posthepatic jaundice</p> Signup and view all the answers

    What role does the testing of urine samples play in toxicology?

    <p>It can detect drugs and their metabolites</p> Signup and view all the answers

    What does the presence of both unconjugated and conjugated bilirubin in serum indicate?

    <p>It suggests a mixed-type jaundice</p> Signup and view all the answers

    What technique is specifically mentioned as being used to confirm the results of premature rupture of membranes (PROM)?

    <p>Mass Spectrophotometry (MS)</p> Signup and view all the answers

    Which component is detected in vaginal secretions after the rupture of fetal membranes using AmniSure TM?

    <p>PAMG-1</p> Signup and view all the answers

    What is the gold-standard technique mentioned for confirmation of screening methods in metabolic diseases?

    <p>Gas chromatography-mass spectrometry (GC-MS)</p> Signup and view all the answers

    Which of the following diseases is included on the list of conditions screened using tandem mass spectrometry?

    <p>Cystic fibrosis</p> Signup and view all the answers

    What sample type is primarily used for fetal newborn screening?

    <p>Dried blood spot specimen</p> Signup and view all the answers

    What is the primary method used for separation and quantitation of drugs and metabolites in the context of acute poisoning?

    <p>Gas Chromatography (GC)</p> Signup and view all the answers

    Which toxic substance is specifically listed in the content related to acute poisoning?

    <p>Cyanide</p> Signup and view all the answers

    What method is NOT mentioned as a technique for analyzing fetal newborn screening?

    <p>Polymerase chain reaction (PCR)</p> Signup and view all the answers

    Which statement best describes the classic method for measuring creatinine levels?

    <p>It reacts creatinine with picric acid in an alkaline solution.</p> Signup and view all the answers

    In what situation is whole blood considered the specimen of choice for tests involving renal function?

    <p>For most renal function assessments except MPA.</p> Signup and view all the answers

    What is the significance of measuring blood urea nitrogen (BUN) in clinical practice?

    <p>It is sensitive to a high protein diet and renal function.</p> Signup and view all the answers

    Which of the following interferes with the measurement of creatinine using the Jaffe reaction?

    <p>Ascorbic acid in the blood.</p> Signup and view all the answers

    What best describes azotemia in relation to renal function?

    <p>It is characterized by increased non-protein nitrogens in plasma.</p> Signup and view all the answers

    Which method for measuring urea levels is dependent on a chemical reaction involving diacetyl monoxime?

    <p>Colorimetric method.</p> Signup and view all the answers

    Which of the following is an accurate statement regarding the glomerular filtration rate (GFR)?

    <p>It is the best laboratory evaluation for suspected renal impairment.</p> Signup and view all the answers

    How does the measurement of blood urea nitrogen (BUN) compare to serum creatinine under conditions of renal impairment?

    <p>BUN often rises more rapidly than serum creatinine levels.</p> Signup and view all the answers

    What does a negative fetal fibronectin (ffN) test indicate regarding premature delivery?

    <p>Preventative measures are unnecessary</p> Signup and view all the answers

    What technique is commonly used to confirm results after Thin-Layer Chromatography (TLC) in drug detection?

    <p>Gas Chromatography-Mass Spectrometry (GC-MS)</p> Signup and view all the answers

    Which specimen type is considered best for detecting drugs in urine via chromatographic methods?

    <p>Urine</p> Signup and view all the answers

    Which protein is detected by AmniSure TM in vaginal secretions after the rupture of fetal membranes?

    <p>PAMG-1</p> Signup and view all the answers

    What is a limitation of Thin-Layer Chromatography (TLC) in drug detection?

    <p>It has limited sensitivity</p> Signup and view all the answers

    In which method is Mass Spectrometry used as a detector for drug identification?

    <p>High-Performance Liquid Chromatography (HPLC)</p> Signup and view all the answers

    Which characteristic is NOT associated with premature rupture of membranes (PROM)?

    <p>Consideration for pneumonia risk</p> Signup and view all the answers

    Which condition would be least relevant for utilizing fetal fibronectin testing?

    <p>Assessing placental abruption</p> Signup and view all the answers

    Which genetic disease is NOT screened using tandem mass spectrometry?

    <p>Hemolytic Disease of the Newborn</p> Signup and view all the answers

    What substance has an affinity for hemoglobin that is 200 times greater than that for oxygen?

    <p>Carbon monoxide</p> Signup and view all the answers

    Which immunosuppressant is commonly used to prevent organ rejection after transplant surgery?

    <p>Cyclosporine</p> Signup and view all the answers

    Which of the following choices correctly identifies substances associated with acute poisoning?

    <p>Heavy metals and alcohols</p> Signup and view all the answers

    What function does urine albumin serve in conjunction with eGFR in chronic kidney disease management?

    <p>To stage and monitor kidney disease</p> Signup and view all the answers

    How is creatinine primarily generated in the human body?

    <p>From muscle breakdown</p> Signup and view all the answers

    Which immunosuppressant is known to inhibit lymphocyte proliferation?

    <p>Sirolimus</p> Signup and view all the answers

    What is a common enzymatic reaction that occurs with ethanol in the liver?

    <p>Oxidation to acetaldehyde</p> Signup and view all the answers

    Which of the following methods can be used for measuring theophylline levels?

    <p>Immunoassays</p> Signup and view all the answers

    What condition can result from severe toxicity of theophylline?

    <p>Cardiac arrhythmias</p> Signup and view all the answers

    Which equation is utilized to estimate glomerular filtration rate (eGFR)?

    <p>MDRD equation</p> Signup and view all the answers

    Which of the following is NOT a characteristic of creatinine clearance?

    <p>More sensitive than eGFR</p> Signup and view all the answers

    What is one advantage of using eGFR over creatinine clearance?

    <p>Does not require urine collection</p> Signup and view all the answers

    Which of the following is an active metabolite of caffeine that requires monitoring in neonates?

    <p>Theophylline</p> Signup and view all the answers

    Which demographic information is NOT typically used in eGFR calculation?

    <p>Weight</p> Signup and view all the answers

    What effect can the use of certain medications have on theophylline metabolism?

    <p>Increased hepatic metabolism</p> Signup and view all the answers

    What is the primary indicator for evaluating renal impairment?

    <p>Glomerular filtration rate (GFR)</p> Signup and view all the answers

    Which method involves the reaction of urea with diacetyl monoxime?

    <p>Colorimetric method</p> Signup and view all the answers

    Which of the following best describes a characteristic of azotemia?

    <p>Elevated non-protein nitrogen levels</p> Signup and view all the answers

    What is a normal BUN/creatinine ratio range?

    <p>10:1 - 20:1</p> Signup and view all the answers

    Which anticoagulant is known to inhibit enzyme activity in serum analysis?

    <p>Sodium fluoride</p> Signup and view all the answers

    Cystatin C is primarily used as a marker for which physiological function?

    <p>Glomerular filtration rate</p> Signup and view all the answers

    Which compound is formed when urea is hydrolyzed by urease?

    <p>Ammonia</p> Signup and view all the answers

    What consequence is associated with impaired renal function in terms of urea excretion?

    <p>Limited urea excretion into the intestine</p> Signup and view all the answers

    Which immunosuppressant is used primarily in combination therapy after organ transplants?

    <p>Tacrolimus</p> Signup and view all the answers

    What method is considered the classic method for measuring creatinine levels?

    <p>Jaffe reaction</p> Signup and view all the answers

    What urine albumin category corresponds to a level of 25 mg/24 hrs?

    <p>A1</p> Signup and view all the answers

    Why might a healthcare provider decide to use multiple samples instead of a single trough collection for certain medications?

    <p>To gain more accurate drug exposure data</p> Signup and view all the answers

    In which circumstance would uric acid levels be expected to be elevated?

    <p>End-stage renal disease</p> Signup and view all the answers

    What is the primary limitation of using serum creatinine to evaluate renal function?

    <p>It can be influenced by muscle mass.</p> Signup and view all the answers

    Which condition would likely lead to elevated blood urea nitrogen (BUN) levels?

    <p>Dehydration</p> Signup and view all the answers

    What is the primary method used for measuring urine albumin in a random sample?

    <p>Immunoassay</p> Signup and view all the answers

    Which of the following factors is NOT considered to affect ammonia levels in a specimen?

    <p>Hydration levels</p> Signup and view all the answers

    What role does urine albumin play in monitoring renal health?

    <p>It indicates the stage of chronic kidney disease.</p> Signup and view all the answers

    Which of the following substances can interfere with the Jaffe reaction during creatinine measurement?

    <p>Glucose</p> Signup and view all the answers

    What is considered a severely elevated urine albumin level?

    <p>700 mg/24 hrs</p> Signup and view all the answers

    What common laboratory technique is used to analyze uric acid levels?

    <p>Colorimetric method</p> Signup and view all the answers

    What is an essential characteristic of Mycophenolic Acid (MPA) regarding specimen collection?

    <p>Serum or plasma is the specimen of choice.</p> Signup and view all the answers

    Which condition is primarily linked to the accumulation of uric acid in the body?

    <p>Gout</p> Signup and view all the answers

    What is the typical urine albumin measurement for a 24 hr collection reported in mg/24 hrs?

    <p>mg/24 hrs</p> Signup and view all the answers

    What is the primary cause of hyper conditions according to endocrine classification?

    <p>End organ problem</p> Signup and view all the answers

    Which metabolic process occurs with the conversion of T4 to T3 in tissues?

    <p>Thyroid hormone activation</p> Signup and view all the answers

    What is the most common cause of hyperammonemia?

    <p>Advanced liver disease</p> Signup and view all the answers

    Which substances can interfere with the measurement of acid to tungsten blue in spectrophotometric assays?

    <p>Lipids and certain drugs</p> Signup and view all the answers

    What type of hormone condition arises from a pituitary problem?

    <p>Secondary</p> Signup and view all the answers

    How is plasma ammonia metabolized under normal circumstances?

    <p>By liver enzymes mainly</p> Signup and view all the answers

    Which byproduct is produced in the uricase reaction during enzymatic assays?

    <p>Allantoin and H2O2</p> Signup and view all the answers

    In which condition would the hypothalamus be responsible for hormone regulation?

    <p>Tertiary endocrine disorders</p> Signup and view all the answers

    What does a BUN/creatinine ratio of 10:1-20:1 typically indicate about renal function?

    <p>Normal renal function</p> Signup and view all the answers

    What is the primary utility of Cystatin C as a serum marker?

    <p>To assess glomerular filtration rate (GFR)</p> Signup and view all the answers

    Which of the following is NOT a common cause of false results for Cystatin C due to specimen handling?

    <p>Prolonged exposure to light</p> Signup and view all the answers

    In the analysis of urine albumin, what does a category A3 classification indicate?

    <p>Severe albuminuria</p> Signup and view all the answers

    What collection method is crucial for accurate ammonia analysis?

    <p>Immediately centrifuging and analyzing samples</p> Signup and view all the answers

    Which parameter is a specific measurement unit for a random urine albumin test?

    <p>mg/g creatinine</p> Signup and view all the answers

    What condition is characterized by elevated cortisol levels leading to symptoms like infertility and masculinization in females?

    <p>Cushing's Disease</p> Signup and view all the answers

    What type of sample handling errors may cause falsely elevated results in Cystatin C testing?

    <p>Sample contamination with bacteria</p> Signup and view all the answers

    Which hormone's measurement is relevant for diagnosing conditions related to pregnancy and stress?

    <p>Estradiol</p> Signup and view all the answers

    Which factor does NOT affect the production of Cystatin C?

    <p>Inflammation</p> Signup and view all the answers

    Which statement accurately describes the relationship between cortisol levels and symptoms in Addison's Disease?

    <p>Cortisol levels are suppressed, leading to fatigue and weight loss.</p> Signup and view all the answers

    What dietary element is notably affected in Cushing's Disease due to elevated cortisol levels?

    <p>Sodium</p> Signup and view all the answers

    Which symptom is NOT directly associated with elevated cortisol levels in Cushing's Disease?

    <p>Hypotension</p> Signup and view all the answers

    What is a significant consequence of low cortisol levels seen in Addison's Disease?

    <p>Hypoglycemia</p> Signup and view all the answers

    What hormone is primarily responsible for stimulating the production of aldosterone?

    <p>Angiotensin II</p> Signup and view all the answers

    Which condition is characterized by an excessive amount of aldosterone?

    <p>Conn's disease</p> Signup and view all the answers

    In Addison's disease, which of the following electrolytes is typically elevated?

    <p>Potassium</p> Signup and view all the answers

    What is a common feature of hypoaldosteronism related to Addison's disease?

    <p>Hyponatremia</p> Signup and view all the answers

    Which of these symptoms can be associated with hyperaldosteronism?

    <p>Muscle weakness</p> Signup and view all the answers

    What is the primary effect of androgens secreted by the adrenal glands?

    <p>Developing male secondary sexual characteristics</p> Signup and view all the answers

    What can result from excessive levels of testosterone in females?

    <p>Masculinization</p> Signup and view all the answers

    In the regulation of secretion through the renin-angiotensin system, what role does renin play?

    <p>Converts angiotensinogen to angiotensin I</p> Signup and view all the answers

    What physiological factor is indicated by the timing of cortisol levels being highest in the morning?

    <p>Diurnal variation</p> Signup and view all the answers

    Which test is directly associated with distinguishing between primary and secondary hyperaldosteronism?

    <p>Direct renin assay</p> Signup and view all the answers

    In the context of testing for testosterone levels, what role do the hypothalamus and pituitary gland play?

    <p>They influence gonadal hormone secretion</p> Signup and view all the answers

    Why must samples for certain tests like renin activity be frozen immediately?

    <p>To prevent degradation</p> Signup and view all the answers

    What is the significance of measuring both free and total cortisol levels?

    <p>To understand hormone activity in different states</p> Signup and view all the answers

    What is the implication of elevated testosterone levels in males during testing?

    <p>Is linked to potential infertility</p> Signup and view all the answers

    What condition can result from the impact of dexamethasone on cortisol production?

    <p>Normal cortisol suppression</p> Signup and view all the answers

    Which aspect of testing for adrenal cortex function can affect interpretation of results?

    <p>Sample time of collection</p> Signup and view all the answers

    What is the primary role of free T4 in the body?

    <p>It is the metabolically active form of thyroid hormone.</p> Signup and view all the answers

    Which condition is characterized by increased thyroid hormones and decreased TSH?

    <p>Primary Hyperthyroidism</p> Signup and view all the answers

    What is the most common cause of advanced hyperammonemia?

    <p>Advanced liver disease</p> Signup and view all the answers

    Which statement about the binding of T4 in circulation is accurate?

    <p>T4 primarily binds to thyroxine-binding globulin.</p> Signup and view all the answers

    What are the symptoms of primary hyperthyroidism?

    <p>Weight loss and heat intolerance</p> Signup and view all the answers

    What characterizes the metabolic activity of bound thyroid hormones?

    <p>They are inactive and serve for storage.</p> Signup and view all the answers

    What laboratory test is considered the best single measure of thyroid function?

    <p>TSH</p> Signup and view all the answers

    Which hormone conversion occurs in the tissues involving T4?

    <p>T4 is converted to T3.</p> Signup and view all the answers

    Which enzyme is notably decreased due to organophosphate poisoning?

    <p>Cholinesterase</p> Signup and view all the answers

    What does elevated conjugated bilirubin in serum and urine typically indicate?

    <p>Obstructive jaundice</p> Signup and view all the answers

    Which parameter is crucial for calculating LDL cholesterol from total cholesterol?

    <p>HDL cholesterol</p> Signup and view all the answers

    What does a biuret method for serum protein measurement primarily rely on?

    <p>Number of peptide bonds</p> Signup and view all the answers

    Which condition is characterized by decreased urine urobilinogen and elevated conjugated bilirubin?

    <p>Obstructive jaundice</p> Signup and view all the answers

    In serum lipid analysis, what is necessary to determine when calculating LDL cholesterol?

    <p>HDL cholesterol</p> Signup and view all the answers

    What action should be taken when an arterial blood sample arrives with a bubble in the syringe?

    <p>Reject the sample because the pO2 will be falsely elevated</p> Signup and view all the answers

    What is indicated by a patient presenting with high serum creatine kinase (CK) and aldolase (ALO) but normal levels of alanine aminotransferase (ALT)?

    <p>Muscular dystrophy</p> Signup and view all the answers

    What is typically indicative of obstructive jaundice in a patient’s lab results?

    <p>Decreased urine urobilinogen</p> Signup and view all the answers

    Why is a volatile organic solvent mixed with urine specimens during thin layer chromatography in drug testing?

    <p>To extract the drugs</p> Signup and view all the answers

    What is the consequence of an obstruction in the bile duct on bilirubin levels?

    <p>Increased conjugated bilirubin in serum</p> Signup and view all the answers

    Which value must be met to classify someone as having diabetes mellitus based on American Diabetes Association criteria?

    <p>Random glucose level ≥ 200 mg/dl</p> Signup and view all the answers

    What is typically expected in the feces of a patient with bile duct obstruction?

    <p>Decreased urobilinogen</p> Signup and view all the answers

    What could falsely elevate potassium levels in laboratory results?

    <p>Hemolysis of the sample</p> Signup and view all the answers

    In the context of diabetes diagnosis, which criterion alone is sufficient for diagnosis?

    <p>Presence of diabetic symptoms with a random glucose of 200 mg/dl</p> Signup and view all the answers

    Which condition would most likely not result in increased serum levels of conjugated bilirubin?

    <p>Hemolytic anemia</p> Signup and view all the answers

    What is the primary function of glycosylated hemoglobin in the assessment of glucose levels?

    <p>Indicates average glucose levels over several months</p> Signup and view all the answers

    What would be the expected result if fasting glucose is measured at 126 mg/dl?

    <p>High fasting glucose suggestive of diabetes</p> Signup and view all the answers

    Which of the following statements regarding LDL cholesterol calculation is correct?

    <p>It is calculated using total cholesterol, HDL, and triglycerides</p> Signup and view all the answers

    What is the best laboratory test for detecting cystic fibrosis?

    <p>Sweat chloride</p> Signup and view all the answers

    What consequence arises from an increased level of urobilinogen in feces?

    <p>Indicates a liver that cannot conjugate bilirubin</p> Signup and view all the answers

    In a patient with diabetic ketoacidosis, which of the following changes would you expect to see?

    <p>Normal pCO2, decreased HCO3, decreased pH</p> Signup and view all the answers

    Which triglyceride level would lead to sample rejection due to falsely reported results?

    <p>210 mg/dL</p> Signup and view all the answers

    What does an increase in urine urobilinogen suggest regarding bilirubin processing?

    <p>Increased breakdown of red blood cells</p> Signup and view all the answers

    What symptom is consistent with hypothyroidism, given the patient's profile?

    <p>Feeling tired all the time and weight gain</p> Signup and view all the answers

    Which method is used to evaluate causes of hypoglycemia?

    <p>Oral glucose tolerance test</p> Signup and view all the answers

    In evaluating electrolyte levels of four patients, which Na+ and Cl- combination may indicate potential dehydration?

    <p>Na+ 153 mmol/L, Cl- 105 mmol/L</p> Signup and view all the answers

    Why would fecal excretion of urobilinogen increase?

    <p>Rise in intestinal bacteria activity</p> Signup and view all the answers

    What is the significance of using the Friedewald formula in lipid analysis?

    <p>Estimates LDL cholesterol concentration</p> Signup and view all the answers

    Which change in bicarbonate (HCO3) levels would indicate metabolic compensation in respiratory acidosis?

    <p>Increased HCO3</p> Signup and view all the answers

    What type of laboratory findings would generally indicate a failure to properly control diabetes?

    <p>Elevated glucose with elevated ketones</p> Signup and view all the answers

    What condition is indicated by a fasting serum glucose of 128 mg/dl and a 2-hour post-load serum glucose of 238 mg/dl?

    <p>Diabetes mellitus</p> Signup and view all the answers

    Which test is most appropriate for monitoring long-term control in a diabetic patient?

    <p>Glycosylated hemoglobin (HbA1c)</p> Signup and view all the answers

    For a patient with symptoms including fatigue, bloating, and elevated blood pressure, which test should be ordered?

    <p>BNP or NT pro-BNP</p> Signup and view all the answers

    Which laboratory result is typically unaffected by hemolysis?

    <p>Sodium</p> Signup and view all the answers

    What is the best indicator of possible coronary risk factors based on a set of test results?

    <p>Higher low-density lipoprotein (LDL) levels</p> Signup and view all the answers

    Which condition is likely represented by a patient who has gained significant weight and presents with swelling in the ankles and hands?

    <p>Metabolic syndrome</p> Signup and view all the answers

    Which of the following results may show abnormalities in patients with diabetes mellitus?

    <p>Elevated glycosylated hemoglobin</p> Signup and view all the answers

    In what scenario is the oral glucose tolerance test (OGTT) primarily utilized?

    <p>To confirm diabetes mellitus diagnosis</p> Signup and view all the answers

    Study Notes

    Stability of Refrigerated Serum

    • Refrigerated serum maintains a fairly constant hormone level.
    • Sodium fluoride is used as an anticoagulant in gray top tubes to slow glycolysis.
    • Fasting reference range for serum or plasma glucose is 70-99 mg/dL.
    • Arterial and capillary glucose values are 2-3 mg/dL higher than venous values.
    • Normal cerebrospinal fluid (CSF) glucose levels are about 60-65% of plasma levels.

    Hormones Affecting Serum Glucose Levels

    • Insulin: Produced by beta cells in the pancreas, reduces serum glucose by stimulating cellular uptake.
    • Glucagon: Released by alpha cells, increases glucose levels by promoting glycogenolysis.
    • ACTH: Anterior pituitary hormone that raises glucose levels as an insulin antagonist.
    • Growth Hormone: Similar to ACTH, it opposes insulin's action and leads to increased glucose.
    • Cortisol: From the adrenal cortex; stimulates gluconeogenesis, increasing glucose from non-carb sources.
    • Human Placental Lactogen: Produced in the placenta, acts as an insulin antagonist.
    • Epinephrine: From adrenal medulla, enhances glycogen breakdown, contributing to hyperglycemia in pheochromocytoma.
    • T3 & T4: Thyroid hormones that stimulate glycogenolysis, raising glucose levels.

    Diabetes Mellitus Diagnosis Tests

    • Fasting Plasma Glucose (FPG): Normal level is below 100 mg/dL.
    • Casual Plasma Glucose: Also should be around 100 mg/dL for normals.
    • Oral Glucose Tolerance Test (OGTT): Used to assess glucose processing.
    • A1c Test: Reflects average blood glucose over 2-3 months.

    Protein Analysis in Serum

    • LDL and VLDL Calculation: Methods include dye-binding and turbidimetric techniques.
    • Clinical Significance of Plasma Proteins: Albumin, globulins, and their liver production roles are crucial for various health conditions.
    • Electrophoresis: Separates proteins based on charge; albumin is the largest fraction (52-62% of serum proteins).
    • Increased Albumin Levels: Caused by conditions like liver impairment or chronic inflammation.
    • Alpha-2-Globulins: Includes haptoglobin and ceruloplasmin, which bind hemoglobin and transport copper, respectively.

    Important Notes on Protein Electrophoresis

    • Protein charge is affected by pH; proteins migrate towards opposite charges in an electrical field.
    • Abnormal migration patterns may indicate clinical conditions, such as hemolysis, liver disease, or malignancies.

    Overall Connection in Glucose Regulation and Hormones

    • Multiple hormones, notably glucagon, cortisol, epinephrine, and growth hormone, consistently raise serum glucose levels, counteracting insulin's effects.
    • Diabetic conditions lead to elevated serum glucose and require careful monitoring via blood tests, including glucose and A1c measurements.

    Symptoms of Diabetes

    • Common symptoms include fatigue, increased thirst, frequent urination, weight loss, poor wound healing, and elevated glucose levels in blood and urine.

    Creatine Kinase (CK)

    • CK is an enzyme indicative of muscle, cardiac, or brain damage.
    • Reference ranges are higher in males due to greater muscle mass and activity levels.
    • CK isoenzymes have different molecular forms:
      • CK1 (CK-BB): composed of two B chains (brain).
      • CK2 (CK-MB): one M and one B chain (cardiac muscle).
      • CK3 (CK-MM): two M chains (skeletal muscle).
    • Trauma to skeletal muscle increases total CK and CK-MB isoenzymes, but CK-MB percentage activity is less than 3%.

    Enzyme Characteristics

    • Enzymes serve as organic catalysts for reactions in the body, with laboratory measurements affected by concentrations of reactants, pH, temperature, ionic strength, and the presence of cofactors.
    • The optimal temperature for enzyme activity is 37°C, and reaction rates double with every 10-degree increase.

    Lactate Dehydrogenase (LD)

    • LD elevation is associated with several conditions, including myocardial infarction, liver disease, muscle trauma, renal infarct, and hemolytic diseases.
    • Measurement methods include spectrophotometric analysis, which quantifies the decrease in absorbance of NADH at 340 nm.

    Aspartate Transaminase (AST)

    • Found in cardiac muscle, liver, and red blood cells; elevated levels indicate myocardial infarction, liver damage, muscle trauma, and renal infarcts.
    • Disorders of the hepatic biliary tree and certain conditions like obstructive jaundice or pregnancy can also lead to increased AST levels.

    Alanine Transaminase (ALT)

    • Predominantly associated with liver disease, particularly hepatocellular damage, providing a more liver-specific diagnosis compared to AST.

    Gamma-Glutamyl Transferase (GGT)

    • Markedly elevated in liver diseases, especially during biliary obstruction and acts as a diagnostic marker for alcohol intake.

    Alkaline Phosphatase (ALP)

    • Optimal activity at pH 10, activated by Mg++.
    • Associated with bone, intestinal mucosa, and renal growth; elevated levels indicate biliary obstruction and diseases affecting bone.

    Amylase and Lipase

    • Amylase is produced by salivary and pancreatic glands, with its elevation most specific for acute pancreatitis.
    • Lipase remains elevated longer than amylase in pancreatitis and is more specific for the condition.

    Acid Phosphatase (ACP)

    • Mainly sourced from the prostate, with elevations indicating prostate cancer, bone diseases, or metastatic conditions.
    • Tartrate-resistant ACP is notable for hairy cell leukemia detection.

    Cholinesterase

    • Enzymes include erythrocyte acetylcholinesterase and plasma pseudocholinesterase, which degrade acetylcholine post-nervous impulse transmission.
    • Low cholinesterase levels can lead to severe neuromuscular issues and are clinically significant in organophosphate poisoning.

    Handling Specimens

    • Proper specimen handling is crucial; hemolysis can skew results, while improper storage can lead to loss of enzyme activity.
    • Samples must be stabilized by removing serum from cells promptly and adjusting pH as required.

    Lipase

    • Elevated in pancreatitis; remains elevated longer than amylase
    • More specific for diagnosing acute pancreatitis
    • Prostatic Acid Phosphatase (ACP) inhibited by tartrate; RBC ACP is not
    • Specimen handling: avoid hemolysis, store serum appropriately to preserve enzymatic activity

    Acid Phosphatase (ACP)

    • Sources: primarily prostate, also in erythrocytes, liver, spleen, bone, kidney
    • High levels indicate metastasizing prostate carcinoma; PSA now preferred over ACP for diagnosis
    • Tartrate-resistant ACP elevated in hairy cell leukemia
    • Useful in forensic medicine for sexual assault cases, but increasingly replaced by PSA

    Cholinesterase

    • Types include erythrocyte acetylcholinesterase and plasma pseudocholinesterase
    • Deteriorates acetylcholine post-nerve impulse transmission; severe deficiency causes neuromuscular issues
    • Elevated in organophosphate poisoning; relevance in anesthetic agents

    Cardiac Markers for Acute Myocardial Infarction (AMI)

    • Myoglobin: indicates muscle damage; rises within 30 minutes, peaks at 4-10 hours
    • CK2 (CK-MB): peaks within 24 hours; replaced by Troponin for AMI detection
    • Troponin: best marker for diagnosing AMI; rises 4-8 hours post-AMI and remains elevated for up to 10 days
    • Troponin subtypes cTnT and cTnI specific to cardiac muscle

    B-type Natriuretic Peptide (BNP)

    • Levels rise in congestive heart failure (CHF), correlating with CHF stages
    • Released by ventricular walls due to hypertension and volume overload
    • Promotes natriuresis and vasodilation, counteracting the renin-angiotensin-aldosterone system (RAAS)

    Liver Markers

    • AST: highest values in hepatitis, also seen in other conditions
    • ALT: highest values indicate liver specificity, particularly in hepatitis
    • ALP: elevated in biliary obstruction, slightly raised in hepatitis
    • GGT: liver-specific enzyme; highest after biliary obstruction or alcohol intake
    • LD: found in multiple tissues but can indicate liver involvement

    Key Clinical Considerations

    • Serum specimens must be handled to prevent hemolysis and enzymatic activity loss
    • Cardiac and liver enzyme assessments play crucial roles in diagnosing and managing diseases
    • Proper understanding of markers, including their specificity and clinical contexts, is vital for accurate diagnosis

    Electrolyte Measurement Overview

    • Low serum magnesium (Mg++) and calcium (Ca++) can indicate unmeasured cation issues.
    • Chloride levels and anion gap are important for evaluating unmeasured anions, such as albumin loss.

    CO2 (Total Carbon Dioxide)

    • Total CO2 includes CO2, bicarbonate (HCO3), and carbonic acid (H2CO3).
    • Reflects bicarbonate concentration, important for acid-base balance.
    • Measurement methods: volumetric, manometric, colorimetric, and pCO2 electrode which detects changes in pH due to CO2.

    Anion Gap

    • Represents the difference between measured cations and anions, essential for electrolyte measurement quality control.
    • Common unmeasured cations include potassium (K+), calcium (Ca++), and magnesium (Mg++).
    • Major unmeasured anions include albumin, sulfate, and phosphate.
    • Calculations can be done with or without K+:
      • Method 1: [(Na+) + (K+)] - [(Cl-) + (HCO3)]
      • Method 2: (Na+) - [(Cl-) + (HCO3)]
    • Reference ranges for anion gap:
      • 10-20 mM/L (using Method 1)
      • 7-16 mM/L (using Method 2)

    Methods of Measurement

    • Atomic absorption spectroscopy is the reference method for measuring ions.
    • Colorimetric methods are most common; for example, calcium reacts with o-cresolphthalein to form a reddish complex.
    • Ion-selective electrode (ISE) measures ionized calcium, avoiding binding issues from proteins during measurement.

    Magnesium (Mg++)

    • Essential as it affects heart function and is vital during renal failure.
    • Conditions leading to decreased magnesium may include cardiac disorders, diabetes mellitus, and diuretics/alcohol use.

    Calcium (Ca++)

    • Crucial for bone health and regulated by hormones such as PTH, calcitonin, and vitamin D.
    • Signs of hypercalcemia include muscle weakness and disorientation, often seen in hyperparathyroidism and certain cancers.
    • Symptoms of hypocalcemia include tetany, frequently due to hypoparathyroidism or vitamin D deficiency.

    Phosphorus (P04)

    • Most phosphate exists in the body as inorganic phosphorus, with an inverse relationship to calcium levels.
    • Elevated phosphorus levels can result from hypoparathyroidism, chronic renal failure, and excess vitamin D.

    Regulation of Calcium and Phosphorus Levels

    • Vitamin D functions as a prohormone, influencing calcium absorption and bone resorption.
    • Exists in two forms: D2 (ergocalciferol) and D3 (cholecalciferol).
    • Intraoperative monitoring of PTH helps assess whether abnormal PTH-producing tissue has been successfully removed during surgery, looking for a >50% decline in PTH levels post-excision.

    pH, HCO3, CO2, and pCO2

    • Sodium heparinate is the recommended anticoagulant for blood sampling.
    • Anaerobic collection methods are vital for accurate pH and blood gas studies.
    • Blood exposed to air can alter measurements, resulting in:
      • Increased CO2 and pCO2
      • Decreased pH and pO2
      • Potassium (K+) depletion
    • Extended testing times (>15 minutes) require keeping blood samples on cracked ice to prevent glycolysis impact, leading to altered CO2, pCO2, and pH levels.

    Metabolic Alkalosis

    • Characterized by excess HCO3 (bicarbonate) levels.
    • Common causes include:
      • NaHCO3 infusion
      • Citrate used in blood transfusions
      • Antacids containing HCO3
      • Vomiting leading to loss of H+ ions and GI-related alkalosis
      • Diuretic therapy
      • Cushing's syndrome, due to excess mineralocorticosteroids
    • Compensation primarily occurs through respiratory mechanisms.

    Respiratory Alkalosis

    • Defined by a primary deficit in CO2 (decrease in pCO2).
    • Commonly associated with:
      • Hyperventilation due to anxiety or other causes
      • Early stages of salicylate poisoning (e.g., aspirin overdose)
    • Compensation primarily occurs through renal mechanisms, increasing H+ excretion.
    • Lab findings indicate increased pH and HCO3, with decreased pCO2 and CO2.

    Evaluating Acid-Base Disorders

    • Assess pH to identify acidosis (<7.35) or alkalosis (>7.45).
    • Compare pCO2 and HCO3 levels to normal ranges:
      • If pCO2 moves oppositely to pH, the cause is respiratory.
      • If HCO3 moves in the same direction as pH, the cause is metabolic.
    • Normal values for blood gas parameters:
      • pH: 7.35-7.45
      • pCO2: 35-45 mm Hg
      • HCO3: 22-26 mM/L
      • pO2: 85-105 mm Hg
    • Full compensation is indicated when pH is normal, despite other abnormalities.

    Compensation Mechanisms

    • Respiratory acidosis is accompanied by increased HCO3 levels as a compensatory response.
    • Respiratory alkalosis results in decreased HCO3 levels.
    • Metabolic acidosis leads to increased pCO2 as a compensatory mechanism.
    • Metabolic alkalosis induces a rise in pCO2.

    Acid-Base Status Determination

    • Utilize a mnemonic involving characters to understand acid-base relationships:
      • Phonetia (pH), Carbo (HCO3), and Paco (pCO2).
      • "R.O.M.E." signifies:
        • Respiratory: pH and pCO2 move in opposite directions.
        • Metabolic: pH and HCO3 move in the same direction.
    • Compensatory responses indicate changes in either respiratory or metabolic functions affecting pH, pCO2, and HCO3 together.

    Lab Tests for Bilirubin Measurement

    • Conjugated bilirubin (direct) reacts rapidly with diazo reagent.
    • Utilizes the Jendrassik-Grof method, which incorporates caffeine benzoate as an accelerator.
    • Direct bilirubin is water-soluble; indirect (unconjugated) is relatively insoluble in water.
    • Differentiation between conjugated and unconjugated bilirubin is crucial for diagnosing hyperbilirubinemia.

    Acid-Base Status Evaluation

    • Metabolic Acidosis indicated by pH 7.24, pCO2 44, HCO3 18; uncompensated condition.
    • Metabolic Alkalosis indicated by pH 7.52, pCO2 44, HCO3 39; uncompensated condition.
    • Uncompensated metabolic alkalosis cannot be distinguished from fully compensated respiratory acidosis using traditional methods in over 90% of cases.

    Hemoglobin Derivatives

    • Breakdown products include porphyrins, bilirubin, and urobilinogen.
    • Urine with high porphyrins shows a "port wine" color.
    • Chromatography techniques (HPLC, ion-exchange) separate porphyrins, demonstrating characteristic pink fluorescence.

    Porphyrins and Bilirubin Testing

    • Watson-Schwartz test identifies porphobilinogen (PBG) by red color formation when reacting with Ehrlich's reagent.
    • Conjugated bilirubin reacts quickly with diazo reagent; measured using Jendrassik-Grof method with caffeine-benzoate as an accelerator.
    • Direct (conjugated) bilirubin is water-soluble, whereas indirect (unconjugated) is less soluble.

    Jaundice Types

    • Pre-hepatic jaundice (e.g., hemolytic anemia) elevates unconjugated bilirubin; liver function remains normal.
    • Hepatic jaundice (e.g., viral hepatitis, cirrhosis) elevates both unconjugated and conjugated bilirubin; liver dysfunction present.
    • Post-hepatic jaundice prevents conjugated bilirubin from entering the intestine, leading to elevated bilirubin levels in urine.

    Bilirubin and Disease States

    • Pre-hepatic jaundice shows elevated unconjugated bilirubin, no conjugated, and positive urobilinogen.
    • Hepatic jaundice shows elevation in both unconjugated and conjugated bilirubin, variable urine bilirubin presence.
    • Post-hepatic jaundice reflects no unconjugated bilirubin but elevated conjugated bilirubin and urine bilirubin.

    Toxicology Testing Methods

    • Immunoassay used for initial screening; results confirm via other methods due to limited sensitivity.
    • Chromatographic techniques (TLC, HPLC, GC) utilized for separation and identification of drugs.
    • Gas Chromatography-Mass Spectrophotometry (GC-MS) serves as a gold-standard for confirming screening results.

    Maternal and Newborn Testing

    • Maternal serum prenatal testing at 16 weeks detects neural tube defects and Down syndrome via markers like alpha-fetoprotein (AFP).
    • Fetal fibronectin (ffN) testing helps predict premature delivery; negative results indicate delivery is unlikely.
    • Tandem mass spectrometry screens for over 25 genetic diseases using dried blood spot specimens from newborns.

    Premature Labor and Rupture of Membranes

    • Premature Delivery Indicators: Fetal fibronectin (ffN) evaluated through vaginal swab specimens; a negative test predicts no preterm delivery, avoiding unnecessary interventions.
    • Premature Rupture of Membranes (PROM): Diagnosis via vaginal swab; AmniSure TM detects PAMG-1 in cervical-vaginal secretions to confirm membrane rupture.

    Toxicology Methods

    • Immunoassay: Utilizes vaginal swab specimens, useful for drug detection but requires confirmation due to limited sensitivity.
    • Chromatographic Techniques:
      • Thin-Layer Chromatography (TLC): Separates drugs; urine is the best specimen for drug detection.
      • Mass Spectrometry (MS): Pairs with High-Performance Liquid Chromatography (HPLC) or Gas Chromatography (GC) for separating and quantifying drugs.
      • Gas Chromatography-Mass Spectrophotometry (GC-MS): Considered the gold standard for sensitivity and reliability.

    Newborn Screening

    • Dried Blood Spot Specimen: Tandem mass spectrometry screens for over 25 genetic conditions including phenylketonuria (PKU) and cystic fibrosis.

    Acute Poisoning

    • Common Toxins:
      • Cyanide: Highly toxic substance.
      • Carbon Monoxide: Forms carboxyhemoglobin, with an affinity for hemoglobin 200 times greater than oxygen.
      • Alcohols: Ethanol is the most frequent; metabolism involves alcohol dehydrogenase.
      • Heavy Metals: Includes arsenic, mercury, and lead.

    Hemolytic Disease of the Newborn (HDN)

    • Key clinical consideration related to newborn health.

    Immunosuppressants

    • Generic Names:
      • Cyclosporine, Tacrolimus, Sirolimus, Mycophenolic Acid (MPA).
    • Usage: Suppress organ transplant rejection; commonly administered in combination.
    • Specimen Requirements: Whole blood preferred except for MPA, which requires serum or plasma; may need multiple samples to assess drug exposure accurately.

    Renal Function Tests

    • Urine Albumin: Used alongside estimated Glomerular Filtration Rate (eGFR) to monitor chronic kidney disease (CKD).
    • Creatinine:
      • Produced from muscle creatine; assesses renal function but less sensitive than GFR.
      • Classic measurement through the Jaffe reaction, which reacts with picric acid to form a measurable colored complex, affected by interferents like glucose and ascorbic acid.

    Blood Urea Nitrogen (BUN)

    • Assessment:
      • Increased BUN indicates renal impairment and high protein diets.
      • Rises quicker than serum creatinine, useful for monitoring.
    • Testing Methods:
      • Colorimetric Method: Urea reacts with diacetyl monoxime to produce a colored complex.
      • Enzymatic Method: Urease enzyme converts urea into ammonia.

    Lithium

    • Used for treating bipolar disorders.
    • Creatinine clearance formula: ( \text{Creatinine} = \frac{U_{\text{creat}} \times \text{Volume (24 hr)}}{P_{\text{creat}}} ), expressed in ml/min.
    • To correct for body surface area: ( \text{Creatinine Clear} \times 1.73 / \text{Area (nomogram)} ).

    Bronchodilators

    • Theophylline used in respiratory conditions; toxicity signs include nausea, headache, and insomnia.
    • Severe effects can lead to cardiac arrhythmias or seizures.
    • Caffeine acts as an active metabolite in neonates; levels should be monitored.
    • Measurement methods: Immunoassays and LC for theophylline and caffeine.

    Immunosuppressants

    • Common types include Cyclosporine, Tacrolimus, Sirolimus, Mycophenolic Acid (MPA).
    • Suppress organ transplant rejection; often used in combination.
    • Whole blood is preferred except for MPA, where serum or plasma is utilized.
    • Multiple samples may be necessary for accurate drug exposure assessment.

    Renal Function

    • Non-protein nitrogens (urea, creatinine, uric acid, ammonia) rise in plasma due to renal impairment (azotemia).
    • Glomerular filtration rate (GFR) is the best evaluation for suspected renal impairment.
    • Creatinine clearance is more sensitive than BUN or serum creatinine.
    • Normal BUN/creatinine ratio is typically 10:1 - 20:1.

    Cystatin C

    • Serum marker for assessing GFR.
    • Produced by nucleated cells; stable across demographics unlike creatinine.
    • Measured via immunoassay.

    Urine Albumin

    • Measured in mg albumin/24 hrs for 24 hr collection or mg albumin/g creatinine for random samples.
    • Categories for albuminuria classification:
      • A1: < 30 mg (normal to mild)
      • A2: 30-300 mg (moderate)
      • A3: > 300 mg (severely elevated).

    Uric Acid

    • Final product of purine metabolism; elevated levels indicative of gout, renal failure, and certain cancers.
    • Measurement by colorimetric method or enzymatic assays, affected by lipids and specific drugs.

    Ammonia

    • Produced by bacterial action in the colon, normally metabolized by the liver.
    • Elevated plasma ammonia levels are toxic to the CNS, often due to liver disease.

    Thyroid Hormones

    • Crucial for metabolic processes, growth, and development.
    • T4 is converted to T3 in tissues; T4 levels are typically higher than T3.

    Anticoagulants and Liver Function

    • Avoid using certain anticoagulants for enzyme analysis as they may inhibit enzyme activity.
    • Conditions affecting liver function include cirrhosis and viral hepatitis.
    • Impaired renal function can lead to increased blood urea due to reduced ammonia excretion.

    BUN/Creatinine Ratio

    • Normal BUN/creatinine ratio ranges from 10:1 to 20:1.

    Cystatin C

    • Cystatin C is a serum marker used to estimate glomerular filtration rate (GFR).
    • It is a small protein produced by all nucleated cells, consistent across individuals, and not influenced by factors such as age, gender, or inflammation.
    • Measurement is done via immunoassay.

    Urine Albumin Measurement

    • Urine albumin levels are reported as mg/24 hours or mg/g creatinine.
    • Categories of albuminuria include:
      • A1: Less than 30 mg/24 hrs (normal to mild)
      • A2: 30-300 mg/24 hrs (moderate)
      • A3: Greater than 300 mg/24 hrs (severe).
    • Hyperammonemia can occur in advanced liver disease.

    Thyroid Hormones

    • T4 is predominantly bound to thyroxine-binding globulin (TBG), with only 0.03% as free T4; T3 has 99.5% bound and 0.5% free.
    • Free fractions of T4 and T3 are metabolically active; bound forms serve for storage and transport.
    • Symptoms of primary hyperthyroidism include weight loss, heat intolerance, and tachycardia, often caused by Graves' disease.

    Thyroid Function Tests

    • Tests include TSH, total thyroxine (T4), free T4, and T3 measurements.
    • TSH is often considered the most sensitive test for thyroid function.

    Renin-Angiotensin System

    • Renin converts angiotensinogen to angiotensin I, leading to the production of aldosterone from the adrenal cortex.
    • Hyperaldosteronism (Conn's Disease) is characterized by increased sodium and potassium levels, along with hypertension.
    • Addison's disease is associated with hypoaldosteronism, leading to decreased levels of sodium and chloride and increased cortisol.

    Androgens

    • Male hormones secreted by testes, adrenal, and ovaries.
    • Elevated testosterone can lead to precocious puberty in boys and masculinization in females.

    Adrenal Cortex Function Tests

    • Cortisol shows diurnal variation, peaking in the morning; can be measured in serum, plasma, or urine.
    • Dexamethasone suppression test measures cortisol response and can indicate conditions such as Cushing's syndrome when cortisol remains elevated despite suppression.

    Important Considerations for Testing

    • Samples for renin activity must be collected in a specific manner, including immediate freezing.
    • Hormonal levels such as estradiol and estriol can be measured to assess estrogen levels in serum and urine.
    • Maintain awareness of hormonal interactions, such as the impacts of cortisol levels on glucose and sodium balances.

    Diabetes and Glucose Testing

    • Oral glucose tolerance test results indicate potential diabetes: fasting serum glucose of 128 mg/dL and 2-hour post-load of 238 mg/dL.
    • American Diabetes Association criteria for diabetes diagnosis include fasting glucose ≥126 mg/dL or 2-hour post-load glucose ≥200 mg/dL.

    Patient Symptoms and Diagnostics

    • A 65-year-old male shows signs of fatigue, shortness of breath, and recent weight gain; blood pressure is elevated and symptoms suggest potential heart failure.
    • Swelling in ankles and hands may indicate fluid retention; suggest testing for BNP or NT pro-BNP for heart function evaluation.

    Lipid Profile and Coronary Artery Disease Risk

    • Total cholesterol, HDL, and LDL levels help assess coronary artery disease risk.
    • Elevated LDL and total cholesterol are significant risk factors; LDL calculation using Friedewald formula yields 168 mg/dL from total cholesterol of 250 mg/dL, HDL of 40 mg/dL, and triglycerides of 210 mg/dL.

    Liver Function and Bilirubin

    • Elevated conjugated bilirubin in both serum and urine, along with low urine urobilinogen, suggests obstructive jaundice.
    • Obstruction leads to conjugated bilirubin entering circulation and being excreted in urine due to its water solubility.

    Electrolyte and Blood Gas Analysis

    • Hemolysis can affect various lab results; sodium levels typically remain unaffected.
    • Arterial blood samples with bubbles should be rejected; bubbles influence pCO2 levels and compromise accurate blood gas analysis.

    Enzyme Levels and Medical Conditions

    • Decreased cholinesterase levels are indicative of organophosphate poisoning.
    • Diagnosis of muscular dystrophy may involve elevated creatine kinase and aspartate aminotransferase but normal alanine aminotransferase.

    Cystic Fibrosis Diagnosis

    • Sweat chloride test is the best laboratory test for cystic fibrosis diagnosis, indicating chloride levels in sweat.

    Understanding Diabetic Ketoacidosis

    • Diabetic ketoacidosis may present with decreased pH, increased pCO2, and low bicarbonate (HCO3) levels, affecting blood gas analysis.

    Drug Testing Techniques

    • Thin layer chromatography employs volatile organic solvents to extract drugs, enhancing the effectiveness of the analytical process.

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