Table 128

Significance of Amniotic Fluid Color Colorless Blood-streaked Yellow Dark green Dark red-brown Traumatic tap, abdominal trauma, intra-amniotic hemorrhage Hemolytic disease of the newborn (HDN), bilirubin Meconium (first bowel movement) Fetal death TESTS FOR FETAL LUNG MATURITY Surfactant Test An FLM test checks the development of an unborn baby's lungs to see if the baby will be able to breathe on his or her own after birth. The test is performed on amniotic fluid. Fetal lung maturity testing...

Hyperthyroidism

Exophthalmos - protrusion of eyeballs due to accumulation of fluid and metabolic products hyperthermia - heat intolerance and higher than normal body temperature Thyroid disorders occur more frequently in women than in men, occurring in up to 10 of all women. Tests for levels of TSH, free thyroxine, and free triiodothy-ronine are need by clinicians to make the diagnosis. Generally, high TSH values suggest primary hypothyroidism, while suppressed levels indicate primary hyper-thyroidism. Signs...

Other Electrolyte Disturbances Resulting From Gastrointestinal Disturbances

Other gastrointestinal illnesses can cause fluid and electrolyte loss as well. Diarrhea is associated with increased gastrointestinal motility and decreased absorption of water and electrolytes in the colon. The result is loss of bicarbonate, sodium, potas sium, and chloride. Metabolic acidosis results from the loss of bicarbonate. Treatment involves replacing fluids and electrolytes in order to reverse the acid-base and electrolyte disturbance.28 This condition is characterized by recurrent...

Other Carbohydrate Metabolic Disorders

There are other disorders that affect glucose and carbohydrate metabolism. Glyco-gen storage diseases often result in hypoglycemia, lactic acidosis, and ketosis. There are several types of glycogen storage diseases. Fructosuria is associated with lactic acidosis, ketosis, and the presence of reducing substances in excess. The laboratory plays a role in assessing these rare, but important, carbohydrate metabolic disorders. Glycogen storage diseases such as type I (von Gierke's disease) are rare...

P

Caused by failure of the liver to conjugate bilirubin. Crigler-Najjar syndrome results from a hereditary deficiency of the UDPG-transferase enzyme. Neonatal jaundice is caused by the inability of the immature liver of the newborn to produce UDPG-transferase. A slight increase in bilirubin in the second and third days of life is a normal response. Damage to hepatocytes by hepatitis, cirrhosis, toxic substances, and other disorders can inhibit conjugation as well. The typical serum bilirubin...

Info

Bronchus(i), function of, 30, 30f B-type natriuretic peptide, 290-291 Buffalo hump, in Cushing's syndrome, 381 Buffers, in acid-base balance, 215-216 Bulimia nervosa, fluid-electrolyte imbalance in, 368 BUN (blood urea nitrogen), 203, 206 BUN-to-creatinine ratio, 212, 212t C3 (complement), 21, 254t C4 (complement), 21, 253t CA 15-3 (cancer antigen 15-3), 471t, 487-488, 556t CA 19-9 (cancer antigen 19-9), 471t, 498, 498t, 556t CA 125 (cancer antigen 125), 471t, 482-487, 484t-487t, 486f, 556t CA...

Respiratory Disorders

Emphysema - chronic pulmonary disease marked by abnormal increase in the airspaces and destructive changes in their walls chronic bronchitis - longstanding irritation and inflammation of the respiratory ducts work of breathing - effort needed to inhale and exhale cyanotic - characterized by bluish appearance due to lack of tissue oxygenation edematous - puffed up due to visible accumulation of fluids As a result of chronic obstructive pulmonary disease (COPD), patients have irreversible...

Pregnancy Tests And Early Markers Of Problems

Questions that were considered in Case Scenario 12-1 will serve to summarize this portion of the chapter 1. What is the main urinary marker for pregnancy Human chorionic gonadot-ropin is the main marker. 2. What is the difference in methodology and clinical value of qualitative and quantitative pregnancy tests Qualitative tests provide positive or negative hCG results to help determine if the patient is pregnant or not pregnant. These are usually simple immunoassay tests performed on a urine...

Pathological Effects of Carbon Monoxide

Hemoglobin combines with CO at a rate of 210 times the affinity of oxygen, thus preventing the formation of further oxyhemoglobin. Carboxyhemoglobin also increases the affinity of hemoglobin for oxygen that has already formed as oxyhemoglobin. Thus, a shift to the left in the oxygen-hemoglobin dissociation curve occurs. In Figure 9-1, the resulting oxygen saturation can be visualized as Po2 levels that fall to the left of this curve.12 This relationship between oxyhemoglobin and Po2 is...

The Team Approach

Since it is important for diabetic patients to eat meals on a regular basis and balance their food intake with activity versus their blood glucose level, it is not practical or necessary for them to fast for 8 to 10 hours prior to a visit to a diabetes center or physician's office for follow-up. Glycated hemoglobin levels do not require a fasting specimen and can be used in conjunction with the patient's self-monitored blood glucose records to determine glycemic control over the past few...

Exercises

As you consider the scenarios presented in this chapter, answer the following questions 1. List protein laboratory tests that are used as sensitive indicators of malnutrition and describe the use of these tests to assess short-term and long-term nutritional status. 2. Describe the roles and functions of vitamins and trace elements in the physiology of the human body. 3. Discuss the principle of the Schilling test. 4. Discuss the etiology of lactose intolerance and list laboratory tests that are...

Complementary or Herbal Medicines Effect on Therapeutic Drug Monitoring

Some chemical constituents of herbal food supplements or plant substances can produce toxic side effects when ingested that are similar to digoxin or digitoxin toxicity. Analytical interference with some immunoassays can occur due to cross-chemical reactions.8,9 Common oleander, a flowering shrub, has been known to impart toxic reactions similar to cardiac glycosides and to cross-react with immunoassay methods. Other herbal supplements that cause similar toxic side effects and immunoassay...

Ghb With Synthetic Glycogen For Cancerous Cells

In aldosterone synthetic pathway, 387f in cortisol synthetic pathway, 380f 11-Deoxycortisol, in cortisol synthetic pathway, 379, 380f, 381 Deoxyhemoglobin, 317-318, 320 Deoxyribonucleic acid. See DNA (deoxyri- bonucleic acid) Depressant drugs, abuse of, 528 Derived beta-quantification calculation, for low-density lipoprotein, 278-279 Derived lipids, 15-16 Desensitization, of hormone receptors, 375, 376f Detoxification, in liver, 235 Dexamethasone, for Cushing's syndrome, 381 Dexamethasone...

Example of Specific CA125 Levels and Presence of Ovarian Cancer

Ovarian Cancer Status (N 113) > 20.0 U L, Positive Test < 20.0 U L, Negative Test No, negative for disease 4, false positive 39, true negative Yes, positive for disease 33, true positive 37, false negative receiver operating characteristic (ROC) curve - a plot of the diagnostic specificity versus sensitivity of a test tivity, or true-positive rate, is 33 (33 + 37) X 100 47 . The specificity, or true-negative rate, is calculated as 39 (39 + 4) X 100 91 . Therefore, the false-positive rate,...

Respiratory Distress Syndrome

Respiratory distress syndrome is a condition of atelectasis due to alveolar collapse. In neonates, as described already, it is due to premature lungs, and in particular lack of lung surfactant. The infant develops rapid, difficult respirations, sometimes with grunting sounds, within a few hours of delivery. Amniotic fluid testing can reveal decreased phosphatidyl glycerol or other phospholipids. The extent of atelectasis and respiratory failure worsens with time. Carbon dioxide retention,...

Diabetes Mellitus

Diabetes is a family of disorders that is characterized by hyperglycemia. The disorders of diabetes differ in their etiology and symptoms and in the consequences of disease. The American Diabetes Association (ADA) estimates that approximately 7 of the population of America suffers from diabetes. Therefore, it is a serious public health threat and economic burden on health care funds.1-3 Timely, specific therapeutic intervention may reduce the serious consequences of diabetes. To aid the...

Calculation Of Fractional Excretion Of Sodium

Fractional excretion of sodium is defined as the fraction of sodium actually excreted by the body relative to the amount filtered by the kidney. FENa is not a test, but rather a calculation based on the concentrations of sodium and creatinine in blood and urine. FENa Na Clearance X 100 creatinine clearance FENa of less than 1 indicates decreased blood flow to the kidney, while FENa of greater than 1 (and usually greater than 3 ) suggests kidney damage.8-11 Case Scenario 6-4 A Case of Renal...

Pathophysiology Of Liver Enzymes Analytical Aspects Of Liver Enzymes

Interpretation of Alkaline Phosphatase Results OTHER LABORATORY TEST RESULTS THAT CORRESPOND WITH LIVER DISORDERS Proteins and Amino Acids Interpretation ofTotal Serum Protein Levels Interpretation of Serum Albumin Levels Case Scenario 7-4. Acute Inflammation of the Liver The Out-of-Range Bilirubin Result Case Scenario 7-5. Acute Liver Failure The STAT Ammonia AMMONIA METABOLISM Hepatic Encephalopathy Liver Function of the Elderly or Pediatric Patient Case Scenario 7-6. Quality Assurance in the...

Congestive Heart Failure Joe Returns

Several months have passed since Joe Smoker had an AMI, but he has not been following the protocols prescribed by his physician. Joe takes blood pressure and anticoagulant medicine, but his diet has slipped back to his old habits of eating saturated fats, fried foods, and red meat. Joe's exercise program stopped once the physical therapy visits were no longer covered by his insurance. On a recent clinic visit to the cardiologist, the physician encourages him to follow the treatment regimen and...

Case Scenario

Type 2 Diabetes With Cardiac Risk Mildred Dodge, the Bonbon Eater Mildred Dodge, at age 62, has had type 2 diabetes mellitus for 12 years. She was at the zoo with her grandchildren when she became faint and dizzy, causing her family to wonder if she was having a diabetic episode. Mildred was brought to the ED for evaluation. She has been taking medication for her diabetes and blood pressure, but this day she had not wanted to take her water pill so she could enjoy her grandchildren at the zoo....

Testing For Thyroid Disorders

The American Thyroid Association recommends a testing decision pathway for thyroid disorders in adult patients. Total thyroxine hormone levels should not be assessed in healthy or asymptomatic patients. In other words, total thyroxine level should not be used as a screening test to investigate for thyroid disease. If signs and symptoms of thyroid disorder are clear, the first laboratory test that should be ordered is TSH.37 If the results are abnormal compared to age- and gender-adjusted...

Clinical Correlation

Type 1 and type 2 diabetes mellitus differ in their clinical presentation as well as their etiology. Type 1 diabetics are usually younger and thinner than type 2 diabetics. Type 1 diabetics present with acute symptoms, while type 2 diabetes develops more slowly over time. Type 1 diabetics are more prone to develop ketoacidosis than type 2 diabetics. secondary result of non-insulin-related events. Blood glucose levels are increased in endocrine disorders, such as Cushing's syndrome in exocrine...

The Adrenal Glands

The two adrenal glands are located immediately anterior to the kidneys. Each adrenal gland consists of two distinct regions, an inner adrenal medulla surrounded by the adrenal cortex. Figure 11-4 depicts the location of the adrenal glands in comparison to the kidneys. Although the adrenal glands are organized into a single gland, the medulla and cortex are functionally different endocrine organs, and have different embryological origins. The adrenal medulla derives from the outermost germ layer...

Test Methodology 89 Highsensitivity Creactive Protein

Measurement of a high-sensitivity C-reactive protein (hs-CRP) complex by light scatter is facilitated by linking the antibody to latex particles. Light scatter is more controlled and reproducible in automated systems using this approach. hs-CRP (sample) + anti-CRP antibody complex Standardization problems are being corrected by an ongoing study by the Centers for Disease Control and Prevention. At present, it is recommended to take two measurements spaced 2 weeks apart, average them, and use...

Acute Myocardial Infarction

Historical Biomarkers of AMI Case Scenario 8-2. Type 2 Diabetes With Cardiac Risk Mildred Dodge, the Bonbon Eater LIPIDS AND LIPOPROTEINS The Role of HDL Physiological Changes in Lipid and Lipoprotein Levels Diabetes and Cardiac Disease National Cholesterol Education Program C-Reactive Protein Primary and Secondary Hyperlipoproteinemia Case Scenario 8-3. Apolipoprotein A Deficiency The Jogger Apoproteins Hyperbetalipoproteinemia Abnormalities With Apoprotein E Abetalipoproteinemia Case Scenario...

W

G protein family action. provide for target organ specificity. The hormone-receptor complex activates the target cell to begin the biochemical reactions that ultimately produce the observed biological response. However, the location of these receptors is different depending on the biochemical nature of the hormone. Protein and catecholamine hormones cannot cross cell membranes and therefore interact with cellular receptors located on the surface of the cell membrane. The action of...

Medical Decision Making for Malignancy Correlating Tumor Marker Results with Likely Disease

The Oncology Department of the University Laboratory wants to offer CA 125 testing. The laboratory will need to collect good data in order to determine the medical decision level for proper interpretation of CA 125 in regard to ovarian cancer. The technologist reviewed recent literature and found a study of women with ovarian cancer that was confirmed with surgical techniques. At the chosen medical decision limit, CA 125 had a diagnostic sensitivity of 65 and specificity of 88 for predicting...

Antiasthmatic Drugs

Antiasthmatic drugs, such as theophylline and theobromine, are used for treatment of neonatal breathing disorders or of respiratory conditions that affect adults or children, such as asthma. Theophylline's action is in bronchodilation and smooth muscle relaxation. Bronchodilation is the term for respiratory airway opening. Anti-asthmatic drugs are usually given intravenously for initial therapy, followed by a regimen of oral dosages. Toxicity causes nausea, vomiting, diarrhea, headache, cardiac...

Test Methodology 121 Qualitative Human Chorionic Gonadotropin By Immunoassay

Qualitative tests provide results that are either positive or negative for the substance to be tested, while quantitative tests provide numerical values as results. In the case of qualitative hCG, a positive test result means the patient is most likely pregnant and a negative result indicates the patient is most likely not pregnant. This test, performed using a urine specimen, is usually less sensitive than a quantitative test but also is a simpler to perform and less expensive. This type of...

Test Methodology 1111 Total Magnesium By Metallochromic Indicator Method

Calmagite acid) forms a colored complex in an alkaline solution with magnesium to be measured spectrophotomet-rically at around 540 nm. Additional substances such as potassium cyanide, a calcium chelating agent, and surfactants are added to minimize interference from calcium, heavy metals, lipemia, or proteins.5 Hemolysis or delayed separation of serum from blood cells should be avoided since either can provide intracellular magnesium. Lipemia and icteric specimens may have interference,...

Diseases Of The Adrenal Cortex

When the cortex region of the adrenal gland is overfunctioning, it is often due to a secreting adenoma, a benign hormone-secreting tumor. Primary hypercorti-solism is the name of this disorder because the disease resides in the primary organ of this endocrine structure, the adrenal cortex. It is associated with increased levels of cortisol throughout the day, loss of diurnal variation, and decreased levels of ACTH. ACTH is low due to the negative feedback response of the pituitary gland, which...

Vitamin A Night Blindness

A combined deficiency in carrier protein and zinc can affect vitamin A function, due to inadequate transport of substrate and inability to convert substrate to active molecule. In this case, the eye does not receive enough retinal to ensure normal function, and the result is night blindness.11 The action of vitamin A on the eye is dependent upon concentration of dietary substrates of the active forms of vitamin A, enzyme catalysts and their cofactors, and transport proteins. Assessment of the...

Alcoholic Liver Disease Nutritional Effects of Alcohol Substance Abuse

Green was having trouble seeing at night. At the Veterans Administration (VA) Clinic, he told the physician that he had recently lost weight and lacked energy to follow his usual pursuits. The physician noted that Mr. Green was a 58-year-old white male who has drunk a six-pack of beer most days of the week on and off for the last 10 years. A visit to the eye clinic at the VA Clinic ruled out anatomic disease of the eye. The physician suspected that the night blindness was due to his poor...

Test Methodology 88 Hdl Cholesterol

Testing for HDL cholesterol (HDL-C) using either precipitation methods or homogenous assays. The precipitation methods use either dextran sulfate, polyethylene glycol (PEG), or phos-photungstic acid with magnesium chloride (MgCl2) to precipitate LDL and VLDL lipoproteins from a fasting serum sample, leaving HDL in the supernatant. This HDL supernatant is then assayed for cholesterol. The resulting answer (in mg dL) represents the amount of HDL in the serum sample. The supernatant is tested for...

Pancreatic Cancer Searching for the Cause of High Amylase Levels

Amylase and lipase tests were ordered on Ms. Jameson, a 57-year-old white woman with a diagnosis of jaundice, diabetes mellitus, and pancreatitis. The medical technologist made a manual dilution for the lipase test since it exceeded linearity of the instrument. The instrument would make a 1 2 dilution prior to reporting and since the method was linear to 400 U L, this indicated that lipase was greater than 800 U L. In this instance the procedure called for a 1 4 dilution in bovine albumin...

Nonsteroidal antiinflammatory drugs NSAIDs

Drugs that reduce inflammation without the use of cortisone or other steroids nonwaived - complex tests that require skill to perform and interpret and are therefore regulated nuclease - an enzyme that participates in the hydrolysis of nucleic acids obesity - body mass index gt 30 kg m2 obstructive - causing blockage oligoclonal - showing small discrete bands in cere-brospinal fluid electrophoresis indicating local production of immunoglobulin G IgG oliguria - decreased urine output, lt 400 mL...

Alphaglucosidase inhibitor blocks hydrolysis of an

Alpha glucoside for control of type 2 diabetes alveolar Po2 - PAo2 the partial pressure of carbon dioxide gas in the alveolar sacs alveolar ventilation - effective air exchange between alveoli and blood alveoli - air sacs at the end of air ducts in the lungs and in contact with capillaries that allow gases to diffuse in or out singular alveolus Alzheimer's disease - progressive brain disorder with deterioration of mental capacity affecting memory and judgment amniotic fluid - liquid that...

Acetaminophen Toxicology

Most analgesics, such as salicylates, acetaminophen, and ibuprofen, do not require TDM because physicians and pharmacists are able to achieve and maintain therapeutic levels with standardized dosing intervals. There is generally a fairly wide therapeutic window for these over-the-counter analgesics. Patients are not prone analgesics - medications that relieve pain to toxicity at typical doses. Because of the presumed safety of these medications, they are available without a prescription and...

Ventilation And Pco2 Relationship

Ventilation is inversely proportional to the resulting Pco2. Ventilation increases in response to a drop in plasma and cerebrospinal fluid CSF pH detected by the respiratory center in the medulla. The respiratory center responds rapidly to CSF pH in relationship to plasma pH. Elevated pH associated with metabolic alkalosis causes a less predictable decrease in ventilation and elevated Pco2, only when alkalosis is severe and prolonged. Likewise, the kidneys compensate for a primary respiratory...

Test Methodology 132 Serum Immunofixation Electrophoresis

Patient's serum diluted in alkaline buffer is placed into six separate wells within agarose gel, which is placed in an electrophoretic chamber, and a standardized voltage is applied to allow separation of the major protein groups by electrophoresis. The result is six identical tracks of separated proteins. One of the tracks is treated with a protein fixative and becomes the reference track. The remaining tracks are treated with specific heavy chain and light chain antisera that react with...

Female Infertility

Infertility can result from ovulatory or uterine problems mechanical problems, including obstruction of the fallopian tubes male fertility factors or multiple factors in either sex or combined female and male factors. Ovulatory problems are the most common cause of female infertility. Polycystic ovarian syndrome PCOS affects up to 5 of reproductive-age women. It is the most common cause of ovulatory infertility. PCOS is a condition characterized by multiple ovarian cysts, often found in a row,...

Test Methodology 1010 Lipase

Lipase enzymes catalyze the hydrolysis of glycerol esters of long- chain fatty acids. Lipase hydrolyzes dietary triacylglycerol at the ester bonds at carbons 1 and 3 of the molecule to produce monoacylglycerols and fatty acids. Lipase acts at the interface between water and lipid, or substrate therefore, the substrate must be in an emulsion, such at that found in association with bile salts. A cofactor, called colipase, is required for the reaction. Lipase is produced by the pancreas. Small...

Test Methodology 32 Correct Operation Of A Micropipette

Micropipette Potin

Always follow the procedure provided by the vendor for the proper use of a micropipette. It is important to follow the recommendation for removing excess fluid from the outside of the pipette tip. For example, for positive displacement pipettes, the manufacturer often recommends dipping the filled syringe in distilled water to remove excess fluid clinging to the outside. For air displacement pipettes, as shown in Figure 3-5, the manufacturer recommends carefully wiping the outside of the...

Tumor Markers For Colorectal Cancer

As mentioned earlier, tumor marker testing should not be used to screen asymptomatic or low-risk patients for cancer because of concerns for poor diagnostic sensitivity and specificity. An example of a test with a high false-positive rate is the fecal occult blood test for colorectal cancer. Colorectal cancer does correlate with fecal occult blood, but there are many other causes of blood in the feces as well. Some noncancerous causes of fecal blood include gastrointestinal GI bleeding false...

Differences In Elderly Patients

Elderly patients may have electrolyte distribution that differs from younger adults. This difference in distribution of water and electrolytes can adversely affect the elderly when taking certain medications, such as diuretics and blood pressure medications. Many diuretics can affect electrolyte levels, especially sodium Na and potassium K distribution and excretion. Diuretic medications affect the kidneys and cause excretion of potassium. Replacement of potassium is needed in many elderly...

Nitrogenous Biomarkers Of Nutritional Status

Biochemical measurements of such compounds as creatinine, albumin, retinol-binding protein, transferrin, and transthyretin provide a quantitative measure of nutritional status. Creatinine is a waste product of muscle metabolism. Measurement of the concentration of creatinine in serum or the excretion of creatinine in urine provides an assessment of total body muscle mass for individuals with normal renal function. Muscle mass is a reflection of proper protein nutrition. Several proteins are...

Siadh Ratio Serum Urine Osmolality

Hypo-osmolality - decreased concentration tonicity of a body fluid due to decreased solute compared to water in the solution hypernatriuric - exhibiting increased urinary sodium Secretion of inappropriate antidiuretic hormone is due to excessive secretion of ADH secondary to a variety of conditions or drugs. It is associated with urinary sodium levels gt 60 mmol L, urine-to-serum osmolality ratio gt 3.0 with no fluid restrictions, and urine osmo-lality gt 100 mOsm Kg following water-loading...

Lipid Metabolism

Humans are able to produce some lipids endogenously and receive some lipids through the diet. Most dietary lipids are digested in the intestine. Bile salts emulsify or break up the large dietary triacylglycerol molecules into very small particles that can be acted upon by digestive enzymes. Pancreatic and intestinal enzymes digest cholesterol and the emulsified triglycerides so that they can enter the intestinal mucosal cell as small aggregates called micelles. Once in the mucosal cell of the...

Test Methodology 123 Estradiol By Immunoassay

A direct immunoassay for estradiol is the most common method of analysis for women of reproductive age. Although there are several types of estrogens, estradiol is the most common estrogen found in the nonpregnant female and is used to assess ovulatory status. Estradiol is bound to binding globulin in serum and must be displaced prior to analysis by one of a variety of methods. In a heterogeneous reaction, estradiol is first displaced from binding globulins with 8-anilino-1-naphthalene sulfonic...

Amniotic Fluid Collection

The primary function of amniotic fluid is to provide a protective cushion for the fetus, allow for movement, and regulate temperature. Amniocentesis is the fluid collection procedure in which a sample of the amniotic fluid surrounding a fetus is removed by means of a fine needle inserted through the abdomen and into the uterus of the pregnant woman. Amniocentesis is commonly performed for women whose pregnancies may be high risk. These risk factors include age of the mother over 35 years,...

Test Methodology 86 Ldl Cholesterol

LDL cholesterol LDL-C may be calculated or measured directly. Friedewald Calculation or Derived Beta-Quantification Testing for LDL-C involves a calculation that includes total cholesterol, HDL cholesterol HDL-C , and trigylceride TG values using the formula LDL-C total cholesterol - HDL-C TG 5 where TG 5 approximates the VLDL cholesterol concentration in the sample. Cannot be used for TG over 400 mg dL Sample Calculation Total cholesterol 350 mg dL triglycerides 150 mg dL HDL-C 30 mg dL LDL-C...

Test Methodology 51 Iron Measurement

Colorimetric Iron Procedures Method 1 Fe Transferrin acid gt Fe apoferritin Fe ReducingAgents transferrin 2Fe Fe complexing chromogen colored complex Fe transferrin Fe apoferritin Fe3 hydroxyamine Fe Fe bathophenanthroline decrease in absorbance Other methods of iron measurement include Electrochemical coulometry sums up electron transition Atomic absorption spectroscopy TEST METHODOLOGY 5-1. IRON MEASUREMENT continued Saturate all binding sites with excess Fe ferric ammonium citrate or ferric...

Ck

Starch amylase maltose maltotriose dextrins Maltose maltotriose glucosidase gt glucose Glucose 1 gt O glucose oxidasH H O gluconolactone If the particle size is larger than the wavelength of the light source, then most of the light will be scattered in the forward direction at an angle of less than 90 degrees for the incident beam. This phenomenon is called Mie scatter. Particles that are smaller than the wavelength of the light source will scatter light in many directions and equally in the...

Cortisol By

This procedure is an automated heterogeneous enzyme immunoassay that utilizes radial partition for its separation phase. Serum Cortisol is freed from its binding proteins by the addition of a sulfonic acid reagent. For urinary free Cortisol levels, urine is extracted first to removed metabolites or conjugates that would cross-react with the antibody. Alkaline phosphatase-labeled cortisol is then added to compete with patient cortisol for specific antibody binding sites on a borosilicate paper...

Test Methodology 125 Fsh By Immunoassay

Patient sample containing FSH is mixed with antibody to FSH attached to glass-fiber paper. A second labeled antibody is added after a wash step and incubated. Following a second wash step, buffer and reagents are added to enhance the signal, which is detected by the photometer. Antibody specificities have greatly improved, minimizing the likelihood of cross reaction with LH, hCG, and other similar chemicals. Fresh serum free from hemolysis, lipemia, or turbidity should be tested within a few...

Creatinine Metabolism

Creatine is synthesized in the liver, pancreas, and kidneys from the amino acids arginine, glycine, and methionine. Creatine is transported through the circulatory system to muscle, brain, and other organs, where it is converted to phosphocrea-tine and acts as an energy reservoir much like ATP. Creatinine is produced as a waste product of creatine and phosphocreatine. Because much of the creatinine is produced in muscle, the amount of creatinine that is measured in blood is proportional to the...

Analysis With Electrochemistry

Electrochemistry is a type of analytical technique that measures ions in solution, by their electrical properties. These ions are called electrolytes and include ionized sodium Na , potassium K , chloride Cl- , bicarbonate HCO3 , and calcium Ca2 . Electrochemistry also involves producing electrons or ions in a chemical electrochemistry - measuring potential, current, or resistance to determine the activity of an analyte resistance - opposing force to flow of electrons in ohms current -...

Laboratory Results In Type 1 Diabetes

A brief examination of the laboratory results in this case suggests an individual with poor glucose control over a long period of time who was experiencing an acid-base imbalance. The increased plasma glucose, serum ketones, whole plasma lactate, urine glucose, and urine ketones were typical of uncontrolled type 1 diabetes. The decreased CO2 suggested an acid-base disturbance, most likely metabolic acidosis. The increased anion gap suggested the existence of unmeasured anions, most likely keto...

References

Rosalki SB, et al Cardiac biomarkers for detection of myocardial infarction perspectives from past to present. Clin Chem 2004 50 2205-2213. 2. Costa MA, et al Incidence, predictors, and significance of abnormal cardiac enzyme rise in patients treated with bypass surgery in the Arterial Revascularization Therapies Study ARTS . Circulation 2001 104 2689. 3. Reddy GC, et al Cardiac troponin-T and CK-MB mass levels in cardiac and non-cardiac disease. Ind J Clin Biochem 2004 19 2 91-94. 4. Katus...

Wendy Arneson and Jean Brickell

Pregnancy Testing Yes or No PREGNANCY Markers of Pregnancy Problems in Early Pregnancy Trophoblastic Neoplasm Multiple Fetuses and Pregnancy Hormones PREGNANCY TESTS AND EARLY MARKERS OF PROBLEMS Case Scenario 12-2. Infertility and Polycystic Ovarian Disease String of Pearls in a Bearded Lady SEX STEROIDS Protein and Peptide Reproductive Hormones ENDOCRINE GLANDS INVOLVED IN REPRODUCTION OVERVIEW OF NORMAL FEMALE REPRODUCTIVE PHYSIOLOGY The Role of Inhibins THE FEMALE...

Renal Impact On Water And Electrolytes

Refer to Figure 6 1, which shows the anatomy of the nephron and its role in filtration of electrolytes, nutrients, and wastes. Notice that filtration removes the majority of electrolytes, nutrients, and waste products and some water in the glomerulus. Reabsorption of much of the sodium, chloride, potassium, minerals, amino acids, glucose, and the like occurs in the proximal convoluted tubule by passive transport, facilitated diffusion, and active transport. More electrolytes and water are...

Clinical Significance Of Alkaline Phosphatase

The ALP results in this case were not physiologically feasible because they were well below the reference range on each patient tested. As discussed earlier in this chapter see Table 7-3 , ALP is present in the cells of most tissues in the body, including the liver, bone, intestinal epithelium, kidney tubules, and placenta. Several isoenzymes of the catalysts are associated with specific tissues and can be used to identify pathological processes in these tissues. The isoenzymes of ALP are...

Role Of Endocrine Glands In Thyroid Function

Hypothalamus Pituitary Tsh Thyroid Axis

Thyroid hormones are secreted based on a complex interaction of the hypothalamus, the adenohypophysis, and the thyroid gland. The hypothalamus has thyroid hormone receptors within many of its cells. It provides a tertiary level of control and stimulation of the thyroid gland by secreting thyrotropin-releasing hormone TRH also known as thyrotropin-releasing factor TRF , a peptide hormone, in response to lower than normal levels of thyroid hormone. Thyrotropin-releasing hormone may have many...

Test Methodology 814 Homocysteine

All forms of homocysteine Hcy are reduced to free homocysteine. Reduced homocysteine binds with fluorescent-labeled antibody F-Ab to form a complex. Fluorescence is detected that relates directly to the amount of homocysteine present in the patient's serum. Serum reducing agent serum-Hcy Serum-Hcy F-Ab-Hcy F-Ab-Hcy-serum Read fluorescence either in a polarization device or a fluorometer. Case Scenario 8-7 The Clot Thickens Joe Returns Again Follow-Up Joe's blood results showed that his...

Disorders Of Water Balance

Polyuric states are those in which excessive urine output occurs unrelated to fluid, alcohol, or caffeine intake, originating in the kidneys or hypothalamic-pituitary region. The term diabetes insipidus reflects lack of ADH release or lack of renal response to ADH. For example, diabetes insipidus from lack of ADH secretion will cause less conservation of water by the renal collecting ducts. Excessive urinary output is dilute. Polyuria can be induced from drinking large amounts of fluid. Urine...

Disorders Of Adrenal Medullary Hormones

The diagnosis of disorders of the adrenal medulla is aided by laboratory measurement of hormone levels. Disorders of the adrenal medulla include pheochromocy-tomas and neuroblastomas. Pheochromocytomas are tumors that produce excess catecholamines. The majority of pheochromocytomas arise from the adrenal medulla. The classic symptoms of pheochomocytomas are those attributable to excess hormone production, which include recurring episodes of sweating, headache, and a feeling of heightened...

Automation

Automation is the process of using a machine to perform steps in laboratory testing with only minimal involvement by the analyst. If one considers all of the steps needed to produce laboratory results from a given sample, at least nine separate steps can be identified. These include specimen identification, specimen volume measuring, sample pretreatment, reagent volume measuring, sample and reagent mixing, incubation, reaction timing and reaction analysis and calculations, and result...

Test Methodology 91 Arterial Blood Gas Analysis pH And Calculations2

A blood gas analyzer measures multiple parameters using a series of electrodes and spectrophotometry measurements. Earlier models used carbon dioxide and air tanks to calibrate the partial pressure of oxygen, or Po2, and carbon dioxide, or Pco2, but newer instruments use tonometered aqueous gas solutions. Oxyhemoglobin and other hemoglobin forms are determined from a standardized spectrophotometer, calibrated with a total hemoglobin standard. Quality control samples are generally commercially...

O

Renin is a proteolytic enzyme synthesized and stored in the juxtaglomerular cells of the renal glomeruli. When stimulated by low plasma volume pressure and hyponatremia, the juxtaglomerular cells release renin into circulation, where it hydrolyzes angiotensinogen, made by the liver, to angiotensin I. Renin release also may be stimulated due to the presence of other hormones and prostaglandins. Angiotensin I is rapidly converted to angiotensin II by circulating angiotensin-converting enzyme...

1

Triiodothyronine T3 - more potent thyroid hormone, also known as 3,5,3'-triiodothyro- thyroxine T4 - main hormone synthesized in the thyroid gland, also known as 3,5,3'5'-tetraiodothyronine Figure 11-9. The normal thyroid axis. negative feedback they influence the hypothalamus and pituitary gland to discontinue release of TRF and TSH. This cycle continues so that thyroid hormones are maintained at optimum steady-state levels. Thyroid-Stimulating Hormone Pituitary Hormone Thyrotropin, or TSH, is...

Tests For Liver Function

The clinical laboratory offers several tests for the assessment of liver function. The enzymes alkaline phosphatase, ALT, AST, GGT, and 5'-nucleotidase are helpful in the assessment of the proper functioning and inflammatory status of the liver. Because the liver is the site for metabolism of carbohydrate, protein, and lipids, as well as for the synthesis of many proteins, the conjugation of bilirubin, and detoxification of drugs and other substances, the liver may be assessed by measurement of...

Growth Hormone

Disorders of Growth Hormone Secretion Case Scenario 11-3. Pheochromocytoma A Red-Haired Woman With a Taste for Bananas ADRENAL MEDULLARY HORMONES DISORDERS OF ADRENAL MEDULLARY HORMONES Pheochromocytomas Neuroblastomas LABORATORY TESTING FOR ADRENAL MEDULLARY DISORDERS Case Scenario 11-4. Neonatal Hypothyroidism Repeat Thyroid Testing on a Baby ROLE OF ENDOCRINE GLANDS IN THYROID FUNCTION Thyroid-Stimulating Hormone Pituitary Hormone Thyroid Hormone Metabolism Hypothyroidism Case Scenario 11-5....

Case Scenario 111

Type 2 Diabetes With Cardiac Risk Mildred Dodge, the Bonbon Eater Apolipoprotein A Deficiency The Jogger Congestive Heart Failure Joe Returns Silent Myocardial Infarction Woman at Risk Medication Toxicity Age-Related Drug Distribution The Clot Thickens Joe Returns Again Arterial Blood Gas Collection and Specimen Handling The Case of the Pink Patient With a Dark Blood Sample Chronic Bronchitis Blue Bloater or Pink Puffer Patient Acute Respiratory Failure Pain Medication Made Things Worse...

Test Methodology 103 Schilling Test

The Schilling test is a test for vitamin B12 absorption. The test requires the cooperation of both the laboratory and the nuclear medicine department. The test is used to differentiate the three main causes of vitamin B12 deficiency dietary deficiency, malabsorption of B12, and pernicious anemia. The Schilling test is a two-step procedure. If results in the first step indicate normal absorption, there is no need to perform the second step of the test. The patient must be fasting. The patient...

Test Methodology 67 Osmolality Measurement

Osmometry measures differences in the colligative properties of solutions. In a freezing point depression osmometer, a thermistor probe and stirring mechanism come in contact with the sample, which is supercooled to approximately -10 C, which is below the freezing point of the sample. A stirring wire vibrates to initiate freezing to a slush stage, and the heat of fusion warms the solution, causing equilibrium in temperature between freezing and thawing state. Variable resistance is measured,...

Test Methodology 41 Glucose

Current procedures that measure glucose use enzymatic methodology. The Reaction Enzymatic Method Three enzymatic approaches to the measurement of glucose have been explored. Enzymatic methods are specific for glucose. The hexokinase method is the reference method for glucose. The method involves two coupled reactions Glucose ATP hexoki nase- Mg2 G6PO4 ADP G6PO4 NADP G6PD gt 6-phosphogluconate NADPH H The increase in absorbance of NADPH at 340 nm is measured as directly proportional to glucose....

Test Methodology 34 Verification Of Pipette Calibration

The following spectrophotometric procedure is used to verify calibration of to deliver transfer or measuring micropipettes that deliver volumes up to 1000 L. This is an example of the use of p-nitrophenol in spectrophotometric verification of the calibration of a 10- L pipette. 1. All glassware should be cleaned, rinsed with distilled water, and dried. 2. Reagents required around 1.0 L of 0.01-mol L NaOH and 100 mL of 105-mg dL p-nitrophenol PNP . Dissolve 105 mg of high-purity PNP in deionized...

Why Women And Men Experience Different Risk For Heart Attacks

The Food and Drug Administration FDA and American Heart Association suggest that women are protected from heart attacks due to lipid plaque before they reach menopause. Estrogen levels in younger women are typically a factor causing them to maintain high levels of HDL in most situations. Once menopause occurs, women experience a reduction in HDL as their estrogen levels decline. Post- menopausal women are at the same risk for coronary artery disease and heart attack as men, particularly if they...

History Of Measurement In The Laboratory

The application of biochemical testing for medical testing began about 100 years ago. One of the first clinical chemists, Dr. Otto Folin, developed quantitative analytical methods for urine analytes of urea, ammonia, creatinine, uric acid, electrolytes, and acidity. He also developed early blood tests, including those for ammonia and creatinine, using the Jaffe method. Dr. Folin helped to establish the clinical significance of renal function and metabolic tests and published the first reference...

Test Methodology 104 Fecal Fat Analysis

Normal fecal lipids consists of 60 fatty acids, 30 sterols, and 10 triacylglycerols. Increased fecal fats are clinically significant to the assessment of pancreatic insufficiency and small intestine disorders. Fecal fat is also increased in biliary obstruction. Direct measurement of fecal fat is used to establish a diagnosis of malabsorption. Steatorrhea is evidence of fat malabsorption but is not always present. Qualitative analysis for fecal fat employs fat-soluble stains, such as Sudan III...

The Biochemistry Of Disease

The clinical chemistry laboratory measures change in biochemical compounds as an indicator of health status or disease processes. Because the biochemical changes of compounds are not uniform in tissue and organs in response to disease, the measurement of selected biochemical markers can be used to monitor diseases processes as they occur in specific living cell systems. For instance, an increase in the concentration of urea nitrogen in the blood may indicate kidney failure and increased...

First Order and Zero Order Enzyme Kinetics

First-order kinetics is described in the following manner as substrate concentration increases, the rate of product formation increases hyperbolically as it combines with available enzyme and, thus, rate of product formation depends on both substrate and enzyme concentration. Zero-order kinetics is described as enzyme activity at maximum velocity Vmax due to excess substrate concentration. Increasing Figure 1-7. Michaelis-Menton curve substrate concentration versus rate of product formation....

Test Methodology 82 Troponin I

Electrophoresis Isoenzymes Ami

Troponin I is a contractile protein along with other troponin proteins found within muscle fibers, including cardiac myofibrils. Cardiac troponin I cTnl has unique specificity to cardiac muscle and is released shortly after cardiac muscle damage. It can be measured in the serum for 1 to 14 days after an AMI with a high degree of sensitivity and specificity. Levels of cTnI above the reference range or medical decision limit reflect irreversible heart muscle damage. The common principle of...

Bilirubin Metabolism

Bilirubin is a degradation product of the heme portion of hemoglobin. Heme is degraded in cells of the reticuloendothelial system, mainly the spleen. The proto-porphyrin ring of the heme is opened to the biliverdin form and iron is released. Biliverdin is reduced to produce the yellow-pigmented molecule bilirubin. The bilirubin molecule, a tetrapyrole, has low solubility in water or plasma. When it is released into blood, it is bound to albumin for transport. Covalently bound bilirubin is...

Test Methodology 36 Centrifuge Maintenance Procedure

Weekly or biweekly depending on usage Clean interior components with soap and water followed by freshly made 10 v v bleach solution, including sample buckets. Wearing protective gloves, wipe interior sides and bottom, taking care when removing broken pieces of glass. TEST METHODOLOGY 3-6. CENTRIFUGE MAINTENANCE PROCEDURE continued Monthly Place two equally balanced containers into the centrifuge, cover, and operate at the most commonly used speed, listening for unusual vibrations. Check the...

Collection And Handling Of Arterial Blood Gases

The specimen for blood gases and pH should be arterial or arterialized capillary blood collected in heparinized plastic containers including syringes and capillary tubes. Ail air bubbles should be removed, and the needle replaced or the ends of the capillary tube fitted with a tight-fitting cover. Air bubbles frequently form during syringe collection but must be expelled before mixing the specimen. The container should hold the correct amount of heparin 0.05 mg heparin mL blood and, after blood...

Hemolysis Why Is the Potassium Level So High Today

A physician called the laboratory to inquiry about a specimen collected from his patient. The plasma potassium concentration had been reported as 5.9 mmol L. This value was abnormally high when compared to the reference range 3.5 to 4.5 mmol L for potassium. The physician was concerned that hemolysis had falsely elevated the potassium result. The technologist checked the sample and assured the physician that there were no visible signs of hemolysis. tourniquet - band used on arm to cause the...

Immunoassay Techniques

An immunoassay is an analytical method that uses antibodies or antigens as reagents to measure specific chemicals, or analytes. The immunoassay has been in use for over 30 years. Results from immunoassays are the basis for many critical human health decisions involving detection of viruses and their antibodies, therapeutic drug monitoring, and screening for drugs of abuse. Over 70 clinical analytes are tested by immunoassay. The immunoassay technique is the basis for many home tests, and even...

Renal Tubular Acidosis

Renal tubular acidosis RTA is a tubular defect of acid-base regulation. This condition is characterized by alkaline pH of the urine with acidic blood plasma pH, which causes depletion of potassium and bicarbonate ions. Typically, secondary muscle and bone weakness occurs due to the profound electrolyte and mineral imbalance, especially from hypokalemia. Renal tubular acidosis can be classified as a primary disorder, such as a proximal tubular defect associated with Fanconi's syndrome or...

Calculations in Arterial Blood Gas Analysis

Given arterial pH and Pco2, the formula to solve for bicarbonate is derived as follows pH pKa log HC03- Pco2 X 0.0301 pH - pKa log HCO3 H2CO3 inv. log pH - pKa HC03- H2C03 inv. log pH - pKa X H2CO3 HCO3- For example, calculate HCO3- given pH 7.50 and Pco2 of 30 mm Hg. 7.50 6.1 log HC03- 30 X 0.0301 7.50 6.1 log HC03- 0.9 1.4 log HC03- 0.9 inv. log 1.4 HC03- 0.9 25 HC03- 0.9 25 X 0.9 HC03- 23 mmol L Base excess BE is best determined from a nomogram or the van Slyke equation. Case Scenario 9-1...

Analysis Of Oxygenation

Oxyhemoglobin O2Hb can be measured using a co-oximeter, a dedicated spectrophotometer. Oxyhemoglobin exhibits peak absorbance at 585 and 540 nm, while deoxyhemoglobin HHb peaks at 594 nm. Total hemoglobin is generally a sum of oxyhemoglobin and deoxyhemoglobin. The formula used to calculate SO2 is the proportion of oxyhemoglobin within the total hemoglobin concentration. In this formula, c represents concentration and Hb represents hemoglobin. Total hemoglobin SO2 cO2Hb cO2Hb Errors in this...

Test Methodology 42 Ketones

This method uses a sodium nitroprusside reagent that also contains glycerine, disodium phosphate, and lactose. Sodium nitroprusside acetoacetic acid acetone lavender color False-positive reactions are due to medications such as L-dopa, methyldopa, 8-hydroxyquinoline, and phenolphthaleins. False-negative reactions can occur due to exceeding linearity of reaction. Dilutions of suspected highly positive results are required to verify actual reaction. False-negative reactions are also due to...

Medical Decision Limits

True positive - result at or above the decision limit in a patient who has the disease false positive - result at or above the decision limit in a patient who does not have the disease true negative - result below the decision limit in a patient who does not have the disease false negative - result below the decision limit in a patient who has the disease Along with determining the reference ranges to correlate with absence of disease, it is also helpful for physicians to have a cutoff value to...

Analysis of Carboxyhemoglobin

Detection of CO can be 1 indirectly through the release of CO gas and measurement in a Conway microdiffusion system, 2 directly through the release of CO gas from the hemoglobin complex using gas chromatography, or 3 by estimation of carboxyhemoglobin by absorbance peaks. The Conway microdiffusion system is a qualitative method for screening for CO gas poisoning. This method is rarely used since it has poor specificity and sensitivity. A more definitive carboxyhemoglobin method is needed for...

Methodology For Diabetes And Exercises

As you consider the scenarios presented in this chapter, answer the following questions 1. Describe the Clinical Practice Guidelines of the American Diabetes Association for the diagnosis of type 1 diabetes, type 2 diabetes, and gestational diabetes. 2. Discuss test specificity for the common methods for analyzing blood glucose. 3. Describe the evidence that indicates that control of blood glucose levels will reduce the severe consequences of diabetes. 4. Explain the use of the measurement of...

Test Methodology 76 Alkaline Phosphatase

Analysis of alkaline phosphatase ALP can be achieved by the modified method of Bowers and McComb10 4-nitrophenyl phosphate H2O ALP, Mg2 , pH 10-3 4-nitrophenoxide Measure an increase in absorbance at 405 nm at 37 C either as endpoint or continuous monitoring. The ALP level U L is calculated using the following formula If 3.0 mL total volume and 0.1 mL sample volume are used, the activity factor is 1604. For example AA min X 1604 0.035 X 1604 56D U L The Specimen Serum or heparinized plasma less...

Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12

Jean Brickell, Wendy Arneson, and Diana Mass Margaret Crellin, Marian Cavagnaro, and Wendy Arneson Laboratory Techniques and Instrumentation, 79 Diabetes and Other Carbohydrate Disorders, 147 Jean Brickell, Vicki Freeman, and Wendy Arneson Hemoglobin Production Disorders and Testing, 179 Assessment of Cardiovascular Disorders, 267 Assessment of Respiratory Disorders, 301 Assessment of Nutrition and Digestive Function, 333 Endocrine Disorders and Function, 371 Wendy Arneson, Karen Chandler, and...

Other Laboratory Test Results That Correspond With Liver Disorders

Beta Gamma Bridging

Since the majority of proteins found in plasma are synthesized by the liver from amino acids, including serine protease coagulation factors, prothrombin time, serum albumin, and serum protein electrophoresis results can be used to indicate declining liver function. For example, serum albumin decreases and prothrombin time becomes prolonged with liver failure. Protein levels also reflect other disorders, such as those in which essential amino acids are not provided by the diet or in which...

Ldh Test Methodology

All cytoplasmic membranes of all cells of the body, especially in osteoblasts bone-forming cells , intestinal mucosa, placenta, and renal tubules. Table 7-3 summarizes tissue origins of key liver enzymes. Methods of analysis for transaminases are presented in Test Methodology 7-4, and for GGT in Test Methodology 7-5. TEST METHODOLOGY 7-4. TRANSAMINASES1 Aspartate Transaminase Analysis of aspartate transaminase AST can be achieved by a coupled reaction involving pyridoxal-5'-phosphate P-5'-P and...

Shl Methodology

As you consider the scenarios presented in this chapter, answer the following questions 1. What are the physiological sources of creatinine, uric acid, and urea 2. What considerations should be made for specimen collection and handling of specimens for serum sodium, potassium, and creatinine and urine creatinine testing 3. How can creatinine clearance results be used in the differential diagnostic causes of renal insufficiency in a patient 4. Differentiate typical laboratory results of renal...