Urine microscopy

Urinalysis can help clarify the cause of ARF. Certain laboratory parameters are helpful in the assessment of renal function with ARF (Table 75-2). Urine microscopy gives further information to assist with determination of the etiology of the ARF (Table 75-3). 

Urine microscopy may reveal casts, WBCs, RBCs, and eosinophils... 

Jenkins RD, Fenn JP, Matsen JM. Review of urine microscopy for bacteriuria. JAMA 1986 255 3397-3403. 

Urine microscopy The microscopic examination of the urine sediment provides enhanced diagnostic efficiency. Hematuria The normal number of erythrocytes in resuspended urine sediment is no more than 1 to 2 per high-powered field. When an abnormal number... 

Two nucleation processes important to many people (including some surface scientists ) occur in the formation of gallstones in human bile and kidney stones in urine. Cholesterol crystallization in bile causes the formation of gallstones. Cryotransmission microscopy (Chapter VIII) studies of human bile reveal vesicles, micelles, and potential early crystallites indicating that the cholesterol crystallization in bile is not cooperative and the true nucleation time may be much shorter than that found by standard clinical analysis by light microscopy [75]. Kidney stones often form from crystals of calcium oxalates in urine. Inhibitors can prevent nucleation and influence the solid phase and intercrystallite interactions [76, 77]. Citrate, for example, is an important physiological inhibitor to the formation of calcium renal stones. Electrokinetic studies (see Section V-6) have shown the effect of various inhibitors on the surface potential and colloidal stability of micrometer-sized dispersions of calcium oxalate crystals formed in synthetic urine [78, 79]. 

Argininosuccinic aciduria. Patients manifest high levels of argininosuccinate in urine, blood and cerebrospinal fluid. Neonates have a stormy clinical course. Almost all have died or sustained severe brain injury. A peculiar finding is trichorrhexis nodosa, or dry brittle hair with nodular protrusions that are best visible with light microscopy. The precise cause is unknown. 

Examination of stained specimens by microscopy or simple examination of an uncentrifuged sample of urine for white blood cells and bacteria may provide important etiologic clues in a very short time. Cultures of selected anatomic sites (blood, sputum, urine, cerebrospinal fluid, and stool) and nonculture methods (antigen testing, polymerase chain reaction, and serology) may also confirm specific etiologic agents. 

Despite the distinct advantages of pneumatic nebulizers, ultrasonic nebulizers may alternatively be used, in some instances, with success. In a recent application, a variation of ultrasonic nebulizer called spray nozzle-rotating disk FTIR interface was successfully applied to confirm the presence of methyltestosterone, testosterone, fluoxymesterone, epitestosterone, and estradiol and testosterone cyp-ionate in urine, after solid-phase extraction and reversed-phase LC separation (151). Using a commercial infrared microscopy spectrometer, usable spectra from 5 ng steroid deposits could be readily obtained. To achieve success with this interface, phosphate buffers in the mobile phase were not used because these nonvolatile salts accumulate on the collection disk and their spectra tend to swamp out small mass deposits. Another limitation of the method was that only nonvolatile analytes could be analyzed because volatile compounds simply evaporated off the collection-disk surface prior to scanning. 

Examination of stained specimens by microscopy or simple examination of an uncentrifuged sample of urine for white blood cells and bacteria may provide important etiologic clues in a very short time. 

Male Wistar-Kyoto rats weighing 150 g receive either continuous administration of the test drug by an osmotic pump (ALZA Co., Palo Alto, USA) or saline. Twenty-four hours later, the rats are injected with 1 ml of nephrotoxic serum. At 9, 12, and 14 days, urine samples are collected and urinary protein levels are measured using the Lowry method. At 14 days the rats are sacrificed under ether anesthesia, and both kidneys are removed. Portions of these tissues are processed for light microscopy, immunofluorescence staining and immunoperoxidase staining. 

Falkenberg FW, Mondorf U, Pierard D, Ganhl C, Mondorf AW, Mai U, Kantwerk G, Meier U, Rindhage A, Rohracker M. Identification of fragments of proximal and distal tubular cells in the urine of patients under cytostatic treatment by immunoelectron microscopy with monoclonal antibodies. Am J Kidney Dis 1987 9(2) 129-37. 

Urine leukocyte esterase (Uv) v and nitrite Does this patient have. a urinary tract infection Positive LE, positive nitrite, or both Send urine to laboratory for microscopy, culture and sensitivity and treat if positive Appropriate use of antibiotics, decreased morbidity... 

A variety of crystals may be present in the urine, including uric acid, calcium oxalate, calcium phosphate, calcium magnesium ammonium pyrophosphate, and cystine. Many of these have a unique crystalline form which permits them to be identified with microscopy. 

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