urine analysis

Topic- Urine analysis
A urinalysis (or "UA") is an array of tests performed on urine and one of the most common methods of medical diagnosis.
The numbers and types of cells and/or material such as urinary casts can yield a great detail of information and may suggest a specific diagnosis.
• Hematuria - associated with kidney stones, infections, tumors and other conditions
• Pyuria - associated with urinary infections
• eosinophiluria - associated with allergic interstitial nephritis, atheroembolic disease
• Red blood cell casts - associated with glomerulonephritis, vasculitis, malignant hypertension
• White blood cell casts - associated with acute interstitial nephritis, exudative glomerulonephritis, severe pyelonephritis
• (heme) granular casts - associated with acute tubular necrosis
• crystalluria -- associated with acute urate nephropathy (or "Acute uric acid nephropathy", AUAN)
• calcium oxalatin - associated with ethylene glycol toxicity
METHODS OF EXAMINATION
Laboratory examination of urine. Urine is a filtrate of the blood and is produced in the kidneys. It is a reflection of the metabolic activity of the body; conditions that affect the normal homeostatic mechanisms are often revealed by a careful analysis of the composition of the urine. Modern routine urinalysis can be divided into two basic procedures: macroscopic and chemical examination, and microscopic analysis.
Macroscopic and chemical examination
Macroscopic examination includes noting the color and clarity of the urine. Normal urine is pale yellow or straw colored and is usually transparent or clear; abnormal urine may vary greatly in color and may show varying degrees of cloudiness. The specific gravity of urine, that is, the ratio of the weight of a volume of urine to that of the same volume of water, is measured routinely. Specific gravity is an indicator of the kidney's ability to concentrate or dilute the urine and thus of renal tubular function. The normal range is 1.003–1.032.
Most routine chemical urinalysis is now carried out by dipstick testing, which involves the use of plastic strips, or dipsticks, bearing pads embedded with chemical reactants and color indicators. The reaction of each pad represents a separate chemical test for a specific product in the urine. Dipstick testing includes the following categories: protein, glucose, ketone bodies, blood, and bile.
Microscopic examination
The urine normally contains a wide variety of formed elements that can be identified by using a light microscope. Together these elements form the urinary sediment.
Cells in the urine originate in the bloodstream or in the epithelium lining the urinary tract. The main types of epithelial cells are renal tubular cells, transitional (urothelial) cells, and squamous cells. All three types occur in relatively small numbers in the normal sediment. Blood cells occur normally in the urine in small numbers, and consist mainly of polymorphonuclear neutrophils (a type of granular leukocyte) and red blood cells.
Casts, proteinaceous products of the kidney, are of major importance when present in increased numbers or seen in abnormal forms, because they usually indicate intrinsic renal disease. Casts are cylindrical and are named on the basis of their microscopic appearance and the cells they contain.
Normally, urine is sterile, and the urinary sediment should not contain microorganisms. However, in patients with serious urinary tract infections, microorganisms are usually present in the urine in considerably greater numbers.
Mucus is frequently found in urine sediment and has no known pathologic significance. A wide variety of crystals appear in the urine; their presence may be normal or may indicate an abnormal state. Ex.Kidney; Kidney disorders.
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Compiled by:- Submitted to:-
Jaypal kumar TV/07-19, Dr. Vasali Ashok
Rakesh Kumar Singh TV/07-43, HOD,
D.Rekha Rv/07-84 Dept Of Vety Biochem