المشاركات

Cryoglobulins

Cryoglobulins Test Description Cryoglobulins are abnormal serum proteins which precipitate at low laboratory temperatures and redissolve after being warmed. When patients with cryoglobulins present in their blood are subjected to cold, they may experience vascular problems of their extremities, with Raynaud-like symptoms such as pain, cyanosis, and coldness of the fingers and toes due to the formed complexes blocking small blood vessels. The presence of cryoglobulins in the blood (cryoglobulinemia) is usually associated with immunologic disease. The test is conducted by refrigerating a serum sample at 4°C for at least 72 hours and observing for the formation of a precipitate. The reversibility of the reaction is verified by rewarming the serum sample. If the presence of cryoglobulins is thus shown, further study is done to identify the cryoglobulin components. EVIDENCE FOR PRACTICE: Evidence of renal disease in hepatitis C virus-positive individuals ...
إرسال تعليق
قراءة المزيد

What is Creatinine Clearance

Test Description: Creatinine is the waste product of creatine phosphate, a compound found in the skeletal muscle tissue. It is excreted entirely by the kidneys. Increased levels of creatinine indicate a slowing of the glomerular filtration rate. The creatinine clearance test consists of two components: a 24-hour urine collection and a blood sample. Conducting both urine and blood testing allows for the comparison of the serum creatinine level with the amount of creatinine excreted in the urine. This is a more sensitive indicator of kidney function than serum creatinine alone. The creatinine clearance normally decreases with aging due to a decline in the glomerular filtration rate. Since “clearance” means the amount of blood cleared of creatinine in 1 minute, a monitoring of the creatinine clearance rate provides valuable information regarding the progression of renal disease. A minimum creatinine clearance of 10 mL/minute is necessary to maintain life without the use of...
قراءة المزيد

What is Creatinine

Test Description: Creatinine is the waste product of creatine phosphate, a compound found in the skeletal muscle tissue. It is excreted entirely by the kidneys. The creatinine level is affected primarily by renal dysfunction and is thus very useful in evaluating renal function. Increased levels of creatinine indicate a slowing of the glomerular filtration rate. Since creatinine levels normally remain constant, even with aging, this test is particularly useful in evaluating renal dysfunction in which a large number of nephrons have been destroyed. The creatinine level is usually determined in conjunction with the blood urea nitrogen (BUN) in assessing renal function. The normal ratio of BUN to creatinine ranges from 6:1 to 20:1. Testing of the creatinine level in the blood is also used to monitor patients on drugs known to be nephrotoxic, such as aminoglycosides. Normal Values                 Female:    0.6–1.2 mg/dL (5...
إرسال تعليق
قراءة المزيد

Creatine Kinase and Isoenzymes

Test Description: Creatine kinase (CK) is an enzyme found primarily in the heart and skeletal muscles, and in smaller amounts in the brain. When the total CK level is substantially elevated, it usually indicates injury or stress to one or more of these areas. When a muscle is damaged, CK leaks into the bloodstream. Determining which isoenzyme (specific form of CK) is elevated will help determine which tissue has been damaged. CK can be measured as the total enzyme in the serum, or each of its three isoenzymes may be measured. The isoenzymes include: CK1 (CPK-BB): produced primarily by brain tissue and smooth muscle of the lungs CK2 (CPK-MB): produced primarily by heart tissue CK3 (CPK-MM): produced primarily by skeletal muscle CK, along with asparate aminotransferase (AST) and troponin, is assessed in the case of suspected myocardial infarction. It typically appears in the bloodstream within 3 to 6 hours of the tissue injury, with peak values occurring 18 to 24 hour...
إرسال تعليق
قراءة المزيد

C-Reactive Protein

Test Description: C-reactive protein (CRP) is a glycoprotein produced by the liver, which is normally absent from the blood. The presence of acute inflammation with tissue destruction within the body stimulates its production. Therefore, a positive CRP indicates the presence of an inflammatory process. When the acute inflammation is no longer present, the CRP rapidly dissipates from the body. The CRP typically rises within 6 hours of the start of inflammation, allowing the inflammation to be confirmed much sooner than through the use of the erythrocyte sedimentation rate (ESR), which usually increases about a week after inflammation begins. There are two types of CRP which can be measured. The standard CRP is used to assess how active inflammation is in such chronic problems as inflammatory bowel disease, arthritis, and autoimmune diseases; to assess for a new infection such as in appendicitis and postoperative conditions; and to monitor response to treatment of these ...
إرسال تعليق
قراءة المزيد

C-Peptide

Test Description:  Proinsulin is converted to insulin in the beta-cells of the pancreas. A by-product of this conversion is C-peptide, an inactive amino acid. C-peptide levels usually correlate with endogenous insulin levels and are not affected by exogenous insulin administration. Measurement of C-peptide levels is useful in: • determining endogenous insulin levels, since the C-peptide level is not affected by exogenous insulin administration; • determining whether hypoglycemia is being caused by nontherapeutic insulin injections (factitious hypoglycemia), in which case the C-peptide level will be low while insulin levels are elevated; • determining presence of an insulinoma, which can be indicated by elevation of both insulin and C-peptide levels; and • monitoring for recurrence of insulinoma, indicated by increasing C-peptide levels. Normal Values                       0.5–2.0 ng/mL (0.17–0.67 nmol/L SI u...
إرسال تعليق
قراءة المزيد

Cortisol in urine

Test Description: In response to a stimulus such as stress, the hypothalamus secretes corticotropinreleasing hormone. This hormone stimulates the secretion of adrenocorticotropic hormone (ACTH) by the anterior pituitary gland. ACTH, in turn, causes the adrenal cortex to release the glucocorticoid hormone, cortisol. Cortisol has several functions, including:           • stimulation of glucose formation (gluconeogenesis)           • stimulation of stored energy molecular breakdown (fats, proteins, carbohydrates)           • promotion of sympathetic responses to stressors           • reduction of inflammation and immune function           • stimulation of gastric acid secretion Most of the cortisol present in the body is bound to cortisol-binding globulin and albumin. Five to ten percent is “free” or unconjugated, and is thus filtered by the kidneys...
إرسال تعليق
قراءة المزيد