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

Terephthalic acid (TPA), dimethyl terephthalate (DMT), and melamine (MA) induced calculi and transitional cell hyperplasia in urinary bladders of rats. A high incidence of calculi was induced in weanling rats, but the incidence was much lower in adult rats ingesting the same dietary concentration of the chemical. The dose-response curves for the induction of urolithiasis in weanling rats were extremely steep, consistent with the fact that the formation calculi can occur in urine that is supersaturated, but not in urine that is undersaturated with respect to the stone components. In the cases of TPA and DMT, stones were composed primarily of calcium terephthalate (CaTPA). By determining the solubility of CaTPA, the concentration of TPA that would be required to achieve urinary saturation was calculated, and a conservative estimate of the amount of TPA or DMT that would have to be absorbed in order to induce calculi was derived. TPA and MA induced bladder tumors in rats in chronic feeding studies. However, it is likely that these tumors were secondary to the development of calculi. TPA and MA are apparently nongenotoxic, and they do not appear to be metabolized. Increased cell replication in the urothelium of the bladder caused by chronic physical injury was probably a major factor in the mechanism of induction of bladder tumors by bladder stones. Bladder neoplasms occurred primarily in the high dose groups, and they were usually, although not invariably, associated with stones. The possibility that stones were passed or were lost during processing of tissues for histopathologic examination could explain the absence of calculi from some of the neoplastic bladders. The formation of bladder calculi is an example of a threshold effect. Although there is strong evidence linking bladder stones with the induction of tumors, the existence of thresholds in chemical carcinogenesis continues to be controversial. A decision by the U.S. Environmental Protection Agency concerning the levels of MA allowed to occur in the food chain indicates that data regarding thresholds, even in the case of urolithiasis, are not being utilized in the risk assessment process.
Regul Toxicol Pharmacol 1985 Sep
PMID:The induction of bladder stones by terephthalic acid, dimethyl terephthalate, and melamine (2,4,6-triamino-s-triazine) and its relevance to risk assessment. 390 81

We describe 193 consecutive individuals with documented urolithiasis in a military population. In contrast to other reports, the prevalence of stone disease was nearly identical in white-and black patients. This unique black population refutes the concept that urinary calculi are rare in blacks.
J Urol 1985 Sep
PMID:Urolithiasis and race: another viewpoint. 403 47

Hypercalcemia, hypercalciuria, and hyperphosphatemia are common findings in acromegaly, yet there are only a few reports on the occurrence of urinary stones in these patients. We reviewed the files of 64 patients with acromegaly. A total of 8 patients had evidence of renal calculi: 4 patients underwent nephrolithotomy, 3 had stones which were seen on intravenous pyelography, and 1 patient voided a stone. Moreover, 2 other patients suffered from recurrent typical episodes of renal colic. In view of the high incidence of urolithiasis in our series we believe that more attention should be paid to detection of urinary stones in acromegalics to avoid further complications and suffering.
Urology 1985 Sep
PMID:Urolithiasis in acromegaly. 403 39

Urinary excretion of N-acetyl-beta-glucosaminidase (NAG), a lysosomal enzyme, was examined in 33 children with hypercalciuria. Urinary NAG excretion in 13 healthy children was 5.84 +/- 9.35 nmole/hr/mg of creatinine (NAG/Cr) (mean +/- SD) compared with 35.61 +/- 42.04 nmole/hr/mg of creatinine in 23 children with renal hypercalciuria, and 28.99 +/- 13.69 nmole/hr/mg of creatinine in ten children with absorptive hypercalciuria. In children with renal hypercalciuria, NAG/Cr excretion was not statistically different between children with either urolithiasis or hematuria without calculi. In six children with renal hypercalciuria, no significant change in NAG/Cr excretion occurred after a mean duration of 25 weeks of hydrochlorothiazide therapy although urinary calcium to creatinine ratios (UCa/Cr) decreased from 0.24 +/- 0.11 to 0.16 +/- 0.11. We conclude that increased urinary calcium excretion produces renal tubular injury and that the renal injury may not be reversed by short-term alterations in urinary calcium excretion.
Am J Dis Child 1985 Sep
PMID:Increased urinary excretion of renal N-acetyl-beta-glucosaminidase in hypercalciuria. 403 32

Patients with recurrent non-infectious calcium urolithiasis were classified metabolically (122 patients). When the magnesium excretion was measured in the metabolic subgroups, a subset of patients (21.6%) could be identified with marked hypomagnesuria as the only metabolic abnormality. A significantly reduced rate of magnesium excretion was found in these normocalciuric stone formers while assessing the overall 24-h urine magnesium excretion or the 24-h urine and fasting urine magnesium to calcium ratio. These differences were apparently not due to factors that might modify renal magnesium excretion, such as parathyroid function, hypercalcemia, hypophosphatemia, alimentary sodium load, age and sex.
Urologe A 1985 Sep
PMID:[Magnesium excretion in recurrent calcium urolithiasis]. 406 Mar 80

Among a normal population, 21.5% of men have a blood level of uric acid above 6.8 mg%. Half of these subjects also present concomitant elevation of at least one other biological parameter. Clinically they differ from normo-uricemic subjects by weight, level of blood pressure and a trend to diabetes. From the recent literature it appears that hyperuricemia by itself does not constitute a risk factor as far as renal and vascular diseases are concerned. However, prevalence of gouty arthritis and urinary stones correlates with the blood uric acid level. Therefore, treatment of asymptomatic hyperuricemia must be avoided, and side effects of the drugs weighed. Acceptable indications for treatment are frequent attacks of urolithiasis or arthritis poorly tolerated by the patients.
Schweiz Med Wochenschr 1984 Sep 15
PMID:[How to treat hyperuricemia?]. 648 56

A short historical review precedes an outline of the impact of eating habits and various nutritional factors on the pathogenesis of urinary stone formation. In the second part of the paper the place of restrictive dietary measures in prophylactic regimes is discussed. Apart from individual restrictions, the increased ingestion of certain foodstuffs may contribute to the successful prophylaxis of urolithiasis. This is documented on the basis of foodstuffs with a high content of citrate and magnesium. According to these findings an alteration of dietary and drinking habits should be a fundamental component of the management schedule of patients with urolithiasis.
Wien Klin Wochenschr 1984 Sep 14
PMID:[Effect of nutrition on the pathogenesis and metaphylaxis of urinary calculi]. 651 16

The urinary excretion of calcium, oxalate, citrate and magnesium, and the relative saturation products in urine of either calcium oxalate or calcium phosphate, were determined in male duodenal ulcer (DU) patients preoperatively (n = 60), and 1 and 5 years following highly selective vagotomy (HSV), and in male healthy controls (n = 30). In DU before HSV citrate and magnesium were lowered, oxalate was in the low normal range and calcium was normal. The calcium oxalate product was lower than in controls, while the calcium phosphate product was unchanged. Within 5 years HSV normalized urinary citrate and oxalate, but not urinary magnesium, and the median urinary pH was lower than pre-operatively. There thus results a normal product for calcium oxalate, but a reduced one for calcium phosphate. It is suggested that: (1) unoperated DU patients have a urine composition similar to that exhibited in normocalciuric recurrent calcium urolithiasis; (2) this spectrum of urinary constituents may be changed by HSV.
Klin Wochenschr 1983 Sep 01
PMID:Urinary excretion of calcium, magnesium, oxalate and citrate in duodenal ulcer patients. Preliminary results before and up to five years after highly selective vagotomy. 663 26

Statistical studies on 2,040 new outpatients, 575 inpatients and 570 operative procedures at our department in 1982 revealed the following. The most frequent diseases among the outpatients were urogenital infections followed by anomalies and tumors. Over half of the inpatients were pediatric patients and the major diseases among inpatients were hypospadias, vesicoureteral reflux, urolithiasis, congenital urethral stenosis and undescended testis. A total of 570 operations were performed on 531 patients, and the major five operations were hypospadias repair (79), optic internal urethrotomy (71), TUR-P (49), ureterocystoneostomy (33) and orchidopexy (32).
Hinyokika Kiyo 1983 Sep
PMID:[Clinical statistics on outpatients, inpatients and operations at the Department of Urology, Hyogo College of Medicine, in 1982]. 667 46

Hydroxamic acid, a potent urease inhibitor, having a high urinary excretion rate is expected to be a therapeutic agent for urolithiasis caused by urea-splitting bacterial infection of the urinary tract. Twenty-one new derivatives of N-aliphatic-acylglycinohydroxamic acids (GHAs) were synthesized, and their inhibitory potencies against the urease activity of sword bean in a phosphate buffer and against the ureolytic activity of Proteus mirabilis in human urine, and their urinary excretion rates in rats were also measured for this purpose I50 values of most of GHAs against the urease activity of sword bean were about 1 to 10 microM and 2-ethyl-n-butyroyl GHA was the most potent inhibitor with the value of 0.79 microM. I50 values of most of the GHAs against the ureolytic activity of Proteus mirabilis were about 5 to 50 microM and n-nonaroyl GHA was the most potent inhibitor with the value of 3.6 microM. 2,2-Dimethylpropionyl GHA had the highest urinary excretion rate with the recovery of 11%. Routes of administration of 2,2-dimethylpropionyl GHA and sex of rats used did not affect the amount of urinary excretion at all. The results in this report suggest that DL 2-methyl-n-butyroyl, 2-ethyl-n-butyroyl and 2,2-dimethylpropionyl GHA are the most hopeful therapeutic agents for urolithiasis among them.
J Pharmacobiodyn 1980 Sep
PMID:Therapy for urolithiasis by hydroxamic acids. III. Urease inhibitory potency and urinary excretion rate of N-acylglycinohydroxamic acids. 700 14


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