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Query: UMLS:C0392525 (nephrolithiasis)
 2,669 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Under the term "non-calcium nephrolithiasis", three types of renal stone formation are considered. (1) Infected nephrolithiasis, which is due to bacteriological ureolysis. Its treatment includes lowering of oversaturation by antibiotics, urease inhibition and/or acidification of the urine; lowering of crystallization by eradicating concomitant infections caused by non-ureolytic organisms; prevention of crystal adherence by exogenous glycosaminoglycans, and prevention of bacterial adherence by glycolipids. (2) Uric acid lithiasis is defined on physico-chemical and physiopathological grounds. Medical treatment consists of increasing water intake, reducing puric acid intake, alkalinizing the urine inhibiting xanthine-oxidase. (3) Cystinuria is described as a nephrolithogenic proximal tubulopathy. Medical treatment includes reduction of urinary cystine concentration by a strong increase of water intake; reduction of urinary cystine excretion by diet and increase of cystine solubility by urinary alkalinization or administration of some thiol compounds.
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PMID:[Physiopathology, etiology and medical treatment of non-calcium lithiasis]. 178 96

Nephrolithiasis is a heterogeneous disorder, with varying chemical composition and pathophysiologic background. Although kidney stones are generally composed of calcium oxalate or calcium phosphate, they may also consist of uric acid, magnesium-ammonium phosphate, or cystine. Stones develop from a wide variety of metabolic or environmental disturbances, including varying forms of hypercalciuria, hypocitraturia, undue urinary acidity, hyperuricosuria, hyperoxaluria, infection with urease-producing organisms, and cystinuria. The cause of stone formation may be ascertained in most patients using the reliable diagnostic protocols that are available for the identification of these disturbances. Effective medical treatments, capable of correcting underlying derangements, have been formulated. They include sodium cellulose phosphate, thiazide, and orthophosphate for hypercalciuric nephrolithiasis; potassium citrate for hypocitraturic calcium nephrolithiasis; acetohydroxamic acid for infection stones; and D-penicillamine and alpha-mercaptopropionylglycine for cystinuria. Using these treatments, new stone formation can now be prevented in most patients.
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PMID:Etiology and treatment of urolithiasis. 196 46

Severe urinary tract infections due to urease-producing bacteria are frequently associated with neurourologic pathologies and complicated by infected nephrolithiasis. Hydroxamic acids, acting as urease inhibitors, can effectively reduce lithiasic risk, normalizing the urinary environment, as well as enhancing the action of antibiotic treatments. A low dosage propiono-hydroxamic acid (PHA) treatment, 60 mg twice a day for 7 days and then 60 mg/day, was used in 15 patients affected with neurourologic pathologies for 3 months. Nine patients were stone-free and 6 stone-bearers. Urinary pH and ammonium decreased in both groups. Halving the PHA dose did not cause any variation in urinary pH or ammonium trends. In the stone-bearing group an increase in these parameters was correlated with urinary infection recurrences. Complete sterilization was achieved in 11 of 14 patients who completed the trial. In the stone-free group no patient had an infectious recurrence after the first month. Two patients in the stone-bearing group had repeated recurrences. One patient dropped out after 45 days due to a decrease in platelets. The efficacy of such low dose treatment makes even long-term or repeated therapies possible, as is often needed by neurourologic patients.
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PMID:Low dosage treatment with propiono-hydroxamic acid in paraplegic patients. 265 39

Struvite nephrolithiasis is caused by infection with bacteria that possess the enzyme urease, and convert urea to ammonia that raises urine pH and crystallizes with magnesium and trivalent phosphate ion. Of the 75 of our 1431 stone patients with struvite stones 52 were women. Struvite stones occurred almost exclusively in women; a minority of women and most men had mixed stones of struvite and calcium oxalate. Increased serum creatinine levels and reduced creatinine clearance were common in patients with struvite stones, not in those with mixed stones; both were rare in calcium stone disease. Men and women with mixed struvite, calcium oxalate stones were hypercalciuric, but women with struvite stones were not. Patients with mixed stones usually had initial symptoms of stone passage, and were less likely to need surgery, including nephrectomy, or to form contralateral stones. Patients with struvite stones usually presented with infection or no symptom, not passage. We conclude that struvite stones occur in two forms. The struvite stone is a disease of women, presumably occurring de novo from infection. The mixed stones occur in both sexes, presumably from secondary infection in hypercalciuric patients who begin with calcium-oxalate stone disease.
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PMID:Reduced glomerular filtration rate and hypercalciuria in primary struvite nephrolithiasis. 343 Sep 61

This study is presented as a debate on nephrolithiasis by a urologist and an internist. The reason is that in 1986 the urologist has become successful at desintegrating almost any stone without open surgery, whereas the internist's approach to the same problem is entirely based upon an understanding of pathophysiological mechanisms. After having reviewed the major risk factors for renal stone disease, i.e. small urine volume, hypercalciuria, hyperoxaluria, hyperuricosuria, very high or very low urine pH and hypocitraturia, the author shows that now it is not only possible to selectively correct each of these disorders, but that in doing so the internist does change the natural history of the disease. For instance, definite remissions have been obtained by advising patients to increase water intake, by administering thiazides to hypercalciurics, pyridoxine to some hyperoxalurics, allopurinol to hyperuricosurics, urease inhibitors to struvite stone formers and citrate to hypocitraturics. Therefore, the author concludes that the role of the urologist and that of the internist are complementary: although the former now desintegrates the stone without open surgery, the latter, who takes care of the same patient next, is now largely able to prevent relapse of nephrolithiasis after determining the cause of the disease.
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PMID:[Renal lithiasis: the internist's viewpoint 1986]. 373 61

We studied the effects of the bacterial urease inhibitor acetohydroxamic acid on the growth of struvite stones in the urinary tract. Eighteen patients who received acetohydroxamic acid (15 mg per kilogram of body weight per day, in divided oral doses) for a mean of 15.8 months were compared in a randomized double-blind study with 19 patients who received placebo for a mean of 19.6 months. Seven patients given placebo reached a pre-determined end point: a 100 per cent increase in the two-dimensional surface area of their stones. No patient who received acetohydroxamic acid had a doubling of stone size (P less than 0.01). Nine patients receiving the drug and one patient receiving placebo required a decrease in dosage or cessation of treatment because of adverse effects (P less than 0.01). Episodes of tremulousness (n = 5, P less than 0.05), which reversed with a decrease in drug dose, and phlebothrombosis (n = 3, P not significant) were limited to the group given acetohydroxamic acid. We conclude that acetohydroxamic acid effectively inhibits the growth of struvite stones in the short term in patients infected with urea-splitting bacteria, but the prevalence of adverse reactions appears to be high and the toxicity and effectiveness of long-term therapy for struvite nephrolithiasis remain to be defined.
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PMID:A randomized double-blind study of acetohydroxamic acid in struvite nephrolithiasis. 647 65

Renacidin (10 per cent hemiacidrin) irrigation has been used in the management of renal struvite calculi in 25 patients. Of these patients 22 were free of stone after irrigation: 16 after dissolution of residual stone fragments postoperatively, 4 after prophylactic postoperative irrigation and 2 after primary, nonsurgical percutaneous dissolution. Recurrent urinary tract infections owing to the original urease-producing bacteria occurred in 14 per cent of these patients and recurrent nephrolithiasis occurred in 9 per cent during an average followup period of 66 months.
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PMID:Hemiacidrin irrigation in the management of struvite calculi: long-term results. 664 80

Renal lithiasis is a frequent disease which recurs in more than 60% of cases. Effective prevention of recurrence can be obtained once the cause has been identified. The laboratory investigation, based on clinical history, analysis of the stone and blood and urine assays, achieves this objective. As the stone is the main indicator of lithogenic disorders, the investigation must start by morphoconstitutional analysis of the stone by reliable physical methods. The results of this analysis guide the clinician towards the biochemical factors responsible for the lithogenic process and, in some cases, directly to certain infectious diseases, such as infections due to urease-positive bacteria, or metabolic diseases, such as primary hyperoxaluria, tubular acidosis or enzymatic deficits of purine metabolism, without forgetting drug causes, responsible for the formation of approximately one per cent of stones. Subsequent investigations guided by analysis of the stone are therefore much more selective and rational. When the stone is not available, the investigation, graduated according to the metabolic activity of the lithiasis, can be guided by its radiological appearance. Dynamic investigations are rarely necessary and must be reserved a second-line procedures for the most severe forms of calcium-dependent stones. In the absence of radiological data and when the stone has not been collected, a basic routine blood and urine investigation must be performed looking for laboratory factors potentially involved in the stone-forming process.
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PMID:[Metabolic assessment of urinary lithiasis in routine practice. Common task of nephrologists and urologists of the Lithiasis Committee of the French Association of Urology]. 923 85

For ages nephrolithiasis has been a widespread disease and clinical statistics prove that its morbidity index is still increasing, thus it becomes a social problem. Peak morbidity usually occurs at the age between 30 and 40, that is why many patients professionally active and creative have to leave their jobs for a long period. In contrast to earlier years, frequency of the disease occurrence in females is systematically increasing and nowadays it is only slightly lower from that in males. Etiology and pathogenesis of the disease is also not entirely explained. It is generally accepted that urinary stone formation is determined by multiple factors which affect first of all chemical composition and physical features of urine. Individual properties of the kidneys and urinary tract and infections especially with urease producing pathogens as well as environmental factors are also taken into account. The most favourable circumstances for nephrolithiasis occurrence is co-existence of all these factors.
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PMID:[Etiology and pathogenesis of urolithiasis]. 929 94

Lesch-Nyhan syndrome (LNS) is caused by a severe deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) and clinically characterized by self-injurious behavior and nephrolithiasis; the latter is treatable with allopurinol, an inhibitor of xanthine oxidase which converts xanthine and hypoxanthine into uric acid. In the HPRT gene, more than 200 different mutations are known, and de novo mutation occurs at a high rate. Thus, there is a great need to develop a highly specific method to detect patients with HPRT dysfunction by quantifying the metabolites related to this enzyme. A simplified urease pretreatment of urine, gas chromatography-mass spectrometry, and stable isotope dilution method, developed for cutting-edge metabonomics, was further applied to quantify hypoxanthine, xanthine, urate, guanine and adenine in 100 microl or less urine or eluate from filter-paper-urine strips by additional use of stable isotope labeled guanine and adenine as the internal standards. In this procedure, the recoveries were above 93% and linearities (r(2)=0.9947-1.000) and CV values (below 7%) of the indicators were satisfactory. In four patients with proven LNS, hypoxanthine was elevated to 8.4-9.0 SD above the normal mean, xanthine to 4-6 SD above the normal mean, guanine to 1.9-3.7 SD, and adenine was decreased. Because of the allopurinol treatment for all the four patients, their level of urate was not elevated, orotate increased, and uracil was unchanged as compared with the control value. It was concluded that even in the presence of treatment with allopurinol, patients with LNS can be chemically diagnosed by this procedure. Abnormality in the levels of hypoxanthine and xanthine was quite prominent and n, the number of standard deviations above the normal mean, combined for the two, was above 12.9.
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PMID:Chemical diagnosis of Lesch-Nyhan syndrome using gas chromatography-mass spectrometry detection. 1282 5


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