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Query: UMLS:C0451641 (urolithiasis)
 3,973 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiments were designed to determine if Gray strain infectious bronchitis virus (IBV) infection increases the incidence of urolithiasis type kidney damage when the urine is already high in Ca and relatively alkaline due to a high Ca-low available P diet (i.e., layer ration). In addition, experiments were conducted to determine the effects of Gray strain IBV on pullet renal function of 6 and 14-wk-old pullets at 2, 5, and 10 days postinoculation (PI). Blood gas parameters were measured to determine the mechanism by which layer ration decreases hydrogen ion concentration [( H+]). Urine flow rate, glomerular filtration rate, electrolyte excretion (Na, K, Ca, P), free water clearance, urine osmolality, urine [H+], and renal plasma flow (para-aminohippuric clearance) were measured to assess renal function. Gray strain IBV increased urine [H+] and decreased renal plasma flow in 6-wk-old pullets, and induced a diuresis in 14-wk-old pullets between 5 and 10 days PI. The layer ration increased Ca excretion and induced a metabolic alkalosis, thus decreasing urine [H+] and causing urolith formation. Feeding layer ration followed by Gray strain IBV infection had an additive effect on the incidence of urolithiasis and gross kidney damage. Gray strain IBV infection 8 wk prior to feeding layer ration did not induce urolithiasis. The results suggest that the additive effect of Gray strain IBV on the incidence of urolithiasis is probably due to tubular damage rather than direct changes in renal function parameters.
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PMID:Order of exposure to high dietary calcium and gray strain infectious bronchitis virus alters renal function and the incidence of urolithiasis. 255 68

Experiments were designed to evaluate the effects of Gray strain infectious bronchitis virus (IBV) and high dietary calcium (Ca), alone and in combination, on renal function in pullets. Eight hundred female Single Comb White Leghorn chicks were raised on starter ration. Five hundred chicks were inoculated intravenously with Gray strain IBV at 4 wk of age; the remaining chicks were not exposed to IBV. At 6 wk of age, IBV-inoculated and uninoculated chicks were randomly divided into two diet treatment groups. Half the chicks were fed commercial grower ration (approximately 1.0% Ca, .6% available P) and half were fed commercial layer ration (approximately 3.25% Ca, .5% available P). Birds remained on their respective diets until 18 wk of age. Kidney function studies were conducted on anesthetized birds at 6 wk of age prior to initiation of the diet treatments, at 10 wk of age, and at 18 wk of age. The layer ration increased Ca excretion, decreased inorganic phosphate excretion, and decreased urine hydrogen ion concentration in 10-wk-old pullets in comparison with the grower ration. These diet effects on kidney function were attenuated when the pullets reached 18 wk of age. The layer ration also caused an 11.5% incidence of urolithiasis, and significantly increased kidney asymmetry in 18-wk-old pullets relative to the effects of the grower ration. Gray strain IBV exposure significantly increased kidney asymmetry in 18-wk-old pullets, but had no gross effect on kidney function clearly related to the etiology of urolithiasis. Gray strain IBV did not enhance the incidence of urolithiasis in any of the age groups.
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PMID:Effect of Gray strain infectious bronchitis virus and high dietary calcium on renal function of Single Comb White Leghorn pullets at 6, 10, and 18 weeks of age. 284 30

Distal RTA is characterized by decreased distal renal tubular hydrogen ion secretion, decreased ability to acidify urine, hypercalciuria, hyperphosphaturia, hypocitraturia, and metabolic acidosis. Because of the resulting alterations in urine composition and pH, patients with distal RTA are predisposed to urolithiasis and renal calcification. Diagnosis of distal RTA is important because it is a potentially reversible disorder that, left untreated, may cause nephrocalcinosis, recurrent urolith formation, moderate to severe metabolic acidosis, and renal failure.
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PMID:Canine distal renal tubular acidosis and urolithiasis. 348 13

The etiopathogenesis of uric acid, sodium acid urate, and ammonium acid urate uroliths in non-Dalmatian dogs appears to be a complex phenomenon. It may involve one or more pathologic and/or physiologic processes acting independently or in concert to increase urinary concentration of lithogenic substances that result in initiation, growth, and retention of urate uroliths. Increased urine uric acid concentration and/or urinary excretion of uric acid appear to be primary predisposing factors in urate lithogenesis. Specific disorders resulting in hyperuricuria may involve abnormalities of increased synthesis, diminished biodegradation, and/or enhance excretion of uric acid. In addition, ammonium ion, hydrogen ion, and other organic and inorganic urine constituents appear to have major influences on urate urolith formation. Unfortunately, many specific disorders of uric acid metabolism and other factors promoting or inhibiting urate urolith formation remain poorly characterized in the majority of non-Dalmatian dogs with urate urolithiasis. Growing awareness of the significance of urate uroliths in non-Dalmatian dogs should encourage further investigation into the identification, characterization, and quantitation of parameters influencing urate lithogenesis. Results of such studies are required for development of practical and effective strategies for treatment and prevention of canine urate urolithiasis.
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PMID:Etiopathogenesis of uric acid and ammonium urate uroliths in non-Dalmatian dogs. 351 3

Urolithiasis (kidney stone formation) is an acquired degenerative kidney lesion affecting sexually mature and immature domestic fowl. For the present study, uroliths were collected from three commercial flocks during outbreaks of urolithiasis. Uroliths also were collected from a research flock in which urolithiasis was induced by feeding immature chickens a diet formulated to contain excess calcium (3.25% Ca) and .4% available phosphorus. All uroliths were tested by x-ray diffractometry, infrared spectrophotometry, and emission spectrography. With one exception, the stones were composed of compact masses of microcrystalline to fine pleomorphic crystals of calcium sodium urate, with random substitution of magnesium for calcium, and potassium for sodium. No initiating nidus was evident. One of four stones from one laying hen flock was positively identified as an ammonium acid (hydrogen) urate. The unique calcium-sodium-urate stone composition in all but one of the stones tested suggests that similar processes were involved in stone formation in the four different flocks.
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PMID:Characterization and composition of uroliths from domestic fowl. 373 19

The urine to blood carbon dioxide tension gradient (U-B PCO2) following alkalinization of the urine (pH = 7.8) has been widely used to assess distal tubular hydrogen secretion. The magnitude of the U-B PCO2 is influenced not only by the rate of hydrogen secretion but also by bicarbonate concentration and water abstraction. Simultaneous administration of sodium bicarbonate and dDAVP improve the reliability of the test in healthy children. Children with distal renal tubular acidosis were not able to increase urinary PCO2, while a normal increase was found in patients with proximal renal tubular acidosis and the Fanconi Syndrome. Four out of nine patients with urolithiasis failed to increase urinary PCO2 following NaHCO3 and dDAVP-administration, despite a normal ability to acidify the urine following NH4Cl administration. To assess the effect of acute alterations in urinary concentration on urinary PCO2, the test was carried out in children with central diabetes insipidus. Despite sharp increase in urinary bicarbonate concentration these patients failed to increase urinary PCO2.
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PMID:The diagnostic value of the urine to blood carbon dioxide tension gradient for the assessment of distal tubular hydrogen secretion in pediatric patients with renal tubular disorders. 640 15

The pathophysiologic consequences of renal function impairment and chronic renal failure among others result from the loss of excretory and regulatory functions of the kidneys. The role of the exchange of cellular hydrogen ions of tubular fluid in the reabsorption of bicarbonate and in the urinary excretion of titratable acid and ammonia (acid-base regulation) is outlined. The effects of decreased glomerular filtration rate on calcium and phosphorus homeostasis are discussed. De novo urolithiasis in these patients is uncommon. However, it is well recognized that they may form matrix stones with calcium oxalate inclusions. Of greater significance is the prophylaxis in those patients, in whom urolithiasis has been the cause of chronic renal failure. In these patients it is of importance to modify the drug dosage or to abandon the prophylaxis when it interferes with the metabolic changes of renal function impairment. Some agents require no modification, others minor or major modifications. Some are even contraindicated. Hazards of stone prophylaxis in chronic renal failure: Acidification - cave metabolic acidosis! Cave RTA! Antibiotic agents - special rules to prevent accumulation. Thiazides - contraindicated! Hypokalemia; hyperuricemia; cave HPT! Triamterene - contraindicated! Acetazolamide (cystinuria) - contraindicated. Spironolactone - contraindicated. Sodium-cellulose-phosphate - Hyperoxaluria, hypomagnesiuria , hyperphosphatemia, cave HPT. Orthophosphate - cave urinary infection, cave poor renal function, cave obstruction. Allopurinol - dose reduction advisable. Brenzbromaron - contraindicated.
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PMID:[Prevention of calculus recurrence in impaired kidney function]. 653 25

Ammonia is quantitatively the major buffer for hydrogen ion in the urine. Further, the excretion of ammonia can be varied by acid base status and is therefore of homeostatic importance. Acid base status exerts its effect on ammonia excretion both directly and also via an effect on renal ammonia production from glutamine. The mechanism of the effect of acid base status on glutamine deamidation and deamination is uncertain. Apart from its homeostatic role in health and disease alterations in renal ammonia production may assume pathological importance in potassium depletion and uric acid urolithiasis.
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PMID:Significance, mechanisms and control of renal ammoniagenesis. 694 3

Sex-dependent stone formation following portacaval shunt (PCS) was investigated in 82 male and 71 female Sprague-Dawley rats. 72.6% of male PCS rats and none of the female PCS rats developed urolithiasis, in 90.2%, potassium-hydrogen-urate stones formed. Hormonal analysis revealed significant alterations in steroid hormones and glucagon postoperatively. Male PCS rats showed a significant decrease in total and free testosterone and an increase in estradiol and glucagon levels. Female PCS rats showed a marked rise in testosterone and glucagon levels as well as a decrease in estradiol plasma levels. Male PCS rats had higher urinary and plasma uric acid concentrations compared to female PCS and sham-operated rats. Loss of testosterone and rise of glucagon in males was correlated with urolithiasis in so far as stone-forming rats had higher concentrations than non-stone-forming PCS rats. Our findings suggest that hormonal alterations might contribute to sex-dependent stone formation in PCS rats.
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PMID:Sex-dependent urolithiasis in the portacaval shunt rat. 2. Hormones and stone formation. 826 10

Stone formation was investigated in 162 male and female Sprague-Dawley rats (96 males and 66 females) following a portacaval shunt and in 58 sham-operated rats which served as controls (31 males and 27 females). 70.8% male and only 7.5% female shunted rats developed urolithiasis. All stones of sufficient size were analyzed. The majority of stones in shunt-operated rats were made of potassium hydrogen urate (23/41), 10 rats had struvite stones without urinary tract infection, the remaining 8 rats had composite stones. Analysis of all stone-bearing control animals revealed struvite stones (6/6). Postoperatively, the rats developed polyuria, elevated potassium and uric acid excretion (all sex dependent). Urinary pH levels did not change significantly. Organ changes (atrophy of the liver, the testes and ovaries, hypertrophy of the kidney and the adrenal glands) were significant and differed according to sex. The role of sex hormones and prostaglandins is discussed.
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PMID:Sex-dependent urolithiasis in the portacaval shunt rat. Part I. 846 Apr 52


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