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At least 19 recordsLinked to original sources
PubMed2001

[Effects of diuretic therapy on spontaneous expulsion of urinary calculi, urinary pH, and crystalluria in lithiasic patients].

OBJECTIVE: High urine volume is known to be an effective measure for preventing stone recurrence. However, only few studies have investigated its effects on crystalluria and spontaneous passage of calculi. The aim of the study was to assess the effects of high diuresis on stone expulsion and recurrence. PATIENTS AND METHODS: 219 patients were consulting for a first stone episode in Urology units in the Mostaganem area between September 1996 and December 1999. All stones were under 6 mm in size. The patients were divided in two groups: group I included 129 patients (68 males, 61 females) who agreed to be on a high water intake, at least 3 liters per day, over a two months period and to be followed periodically by crystalluria examination in the first morning urine; group II included 90 patients (63 males, 27 females) who declined diuresis advice and urine collection for crystalluria examination. First morning urine collected in patients of group I were examined before (2.95 voidings per subject) and while on diuresis course (2.84 voidings per subject). For each sample, the urine pH was measured and crystals were looked for by polarizing microscopy. Stones spontaneously passed were collected and analyzed by infrared spectroscopy. Group II represented the control group for stone passing and recurrence. RESULTS: Crystalluria was present in 52.4% of urine samples before starting diuresis and decreased at 22.9% of urine samples on high diuresis. Mean pH value increased from 5.73 +/- 0.46 before to 6.09 +/- 0.47 (p < 10-6) while on diuresis course in males and from 5.8 +/- 0.68 to 6.24 +/- 0.66 in females (p < 10-6). The most frequent crystalline species was weddellite. Over the study period, 98 patients (76%) in group I and only 13 patients (14.4%) in group II passed stones spontaneously (p < 10-6 contre group I). No stone recurrence was observed in group I while 37.8% of patients in group II presented at least one stone recurrence (p < 10-7). CONCLUSION: A high diuresis is an effective measure (1) to make easier the passing of stone under 6 mm in size; (2) to reduce the occurrence of crystalluria; (3) to reduce significantly, because of its favourable effect on urine pH, the formation of pH-dependent crystalline phases, thus decreasing heterogeneous nucleation process of calcium oxalate and stone recurrence.

Adolescent↗
PubMed1977

Excretion of 4-pyridoxic acid and oxalic acid in patients with urinary calculi.

Urinary excretion of 4-pyridoxic acid and oxalic acid was investigated in 75 patients with urinary calculi and in 50 normal subjects on regular diet. Mean excretion of 4-pyridoxic acid was 0.85 and 0.90 mg per day, respectively, and mean excretion of oxalic acid was 27.5 and 28.0 mg per day, respectively. Statistically there was no difference between the two groups in 4-pyridoxic acid excretion or in oxalic acid excretion. There was a weak positive correlation between the urinary excretion of 4-pyridoxic acid and oxalic acid. Patients who were on ascorbic acid supplementation during the urine collection period excreted increased amounts of oxalic acid. It was concluded from this investigation that most patients with urinary calculi had 4-pyridoxic acid excretion and oxalic acid excretion within normal limits. Low 4-pyridoxic acid values were not combined with high excretion values of oxalic acid, and the nutritional state of vitamin B6 in patients with urinary calculi was assumed to be satisfactory in order to control the endogenous oxalic acid production. The significance of high excretion values of 4-pyridoxic acid and oxalic acid is discussed.

Ascorbic Acid↗
PubMed2003

Drug-induced urinary calculi.

Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary.

Journal Article↗
PubMed1994

Analysis of urinary calculi.

Urinary calculi are often small (< 5 mg) and can be composed of many very different constituents. The highly variable composition has lead to the development of many different methods of calculi analysis. In general the analytical methods can be divided in chemical and physical methods. Chemical methods are destructive and need several mg of sample. The smallest stones can not be analyzed with chemical methods. Qualitative and semi-quantitative chemical analysis methods are not accurate and can lead to clinical significant errors. Quantitative, instrumental, chemical analysis is accurate and makes no clinical significant errors, but these consume too much sample. None of the chemical methods of stone analysis makes it possible to distinguish the mineral constituents with similar chemical composition, e.g. the calcium phosphates, from one another and they usually can not identify "unexpected" stones. Physical methods need less sample than chemical methods and physical methods can distinguish the different minerals in the stones. Thermal analysis can give quantitative results but needs relatively much sample. Optical methods can analyze a few grains of stone but gives only qualitative results. Both methods can not be used to analyze an "unexpected" stone. Best suited methods for the analysis of calculi are X-ray diffractometry and IR spectroscopy. X-ray diffractometry can detect crystalline minerals in low concentrations. IR spectroscopy can detect both crystalline and amorphous minerals. Both methods can be used for semi-quantitative stone analysis and can analyze less than one mg of stone sample. X-ray diffractometry and IR spectroscopy are also the best methods to identify "unexpected" stone constituents.

Calcium Oxalate↗
PubMed1996

[Complications of urinary calculi].

Urinary stones is a frequent disease whose renal complications can engage both functional and vital prognosis. We report 769 complicated cases observed 10 years. The diagnosis was made by intravenous urography and ultrasonography. 607 cases were mechanical complications, 582 hydronephrosis, 25 anuria, 262 were infectious complications, 82 chronic pyelonephritis, 60 pyonephrosis, 10 perinephric abscess. Treatment included adapted antibiotic therapy, ureteral catheter in case of anuria ; surgical extraction of the stone nephrectomy was performed in 100 patients. Results were generally good. 9 patients had endstage chronic renal failure. The high frequency of urinary stone complications is due to the fact that most patients consult late. The diagnosis must obviously be made.

Adult↗
PubMed1986

Urinary calculi and urinary tract infection. A clinical and microbiological study.

The problem of urinary calculi in association with urinary tract infection (UTI) was investigated. Fifty-two (7%) of 796 patients attending our outpatient stone clinic had UTI which was considered of pathogenic importance for their stone formation. Proteus was the most common microorganism. Metabolic disorders were found in one third and anatomical and functional abnormalities in two thirds of the patients. The infected patients had lower urinary calcium excretion and higher serum creatinine than idiopathic stone formers and had a higher frequency of stone operations. The prevalence of staghorn calculi as a cause of urimia was low (1.5% of 481 dialysis patients). Eight such patients were studied and six of them had metabolic and anatomical disorders. The time taken for the uremia to develop was 7.4 +/- 2.0 (SD) years. In 535 patients treated surgically for renal calculi, about one third had positive urine culture at the time of operation and E. coli was the most common bacterial strain (35%). Proteus was found in 28% and these patients had the highest frequency of UTI episodes, most of which occurred before hospitalization. Patients infected with E. coli had a higher frequency of phosphate-containing calculi than non-infected patients, in whom the highest frequency of calcium oxalate calculi was found. A new broad-spectrum cephalosporin, ceftazidime, was used as perioperative prophylaxis in 15 patients operated upon for renal calculi and UTI. Ten had bacterial growth in the renal pelvis and all strains were eradicated. Bacterial growth was found in two out of six cultured stones from patients with bacterial growth in the pelvis. The pharmacokinetics of the drug was studied and the decreases in the ceftazidime levels in serum and renal tissue seemed to be parallel. Bacterial binding of urinary isolates to hydroxyapatite (HAP) particles was studied. Two E. coli strains (A5089 and E7704) and one Proteus mirabilis strain (A5076), all obtained from stone patients, were compared with two E. coli strains (2683 and M7810) with well defined cell-surface properties. Hemagglutination tests were performed and the cell-surface hydrophobicity was determined by a salt-aggregating test. When the strains were cultured at 37 degrees C to promote fimbriae formation they hemagglutinated erythrocytes and displayed hydrophobic cell-surface properties, and showed higher capacity for binding to HAP than when cultured at 18 degrees C to suppress fimbriae formation, when they showed almost complete absence of hemagglutination and low cell-surface hydrophobicity. Bacterial cell-surface properties seem to influence the binding of uropathogens to HAP particles.

Acute Kidney Injury↗
PubMed1989

[Urinary tract infection associated with urinary calculi. 1. The significance of urinary tract infection in urinary calculi].

We investigated 158 cases of urinary stones (infection stones 56, metabolic stones 102) with special reference to pyuria, bacteriuria, stone culture and urease activities of isolated bacteria. Abacterial pyuria was noted in 9 out of 49 (18%) infection stones and in 53 of 77 (69%) metabolic stones. Bacteriuria was noted in 79% of the infection stones and 26% of the metabolic stones. Sixty-seven percent of the infection stones were infected with mainly urea splitting bacteria such as Proteus mirabilis and Staphylococcus. Twenty-three percent of metabolic stones were also infected. Though E. coli, a non-urea splitting bacteria, was isolated most frequently from metabolic stones, urease positive Staphylococcus and Pseudomonas were also isolated. Bacteria within stones could be predicted on the basis of urine culture results of only 20 of 41 infection stones and 8 of 24 metabolic stones. These facts are useful for selection of some antibiotics in the treatment of urinary tract infections associated with urinary calculi. Urinary infections of urea splitting bacteria in infection stones are thought to be initial factors of stone formation and those of non-urea splitting bacteria are to be superimposed. However, urea splitting bacteria in metabolic stones may convert them into infection stones in future.

Adult↗
PubMed2000

[Socioeconomic aspects of urinary calculi and metaphylaxis of urinary calculi].

A calculation model was developed for the cost of stone therapy and metaphylaxis in Germany based on estimates of stone incidence, types and recurrence rates, actual costs for stone removal and metaphylaxis (based on data from a district of the social health care system). There are 200,000 stone recurrences per year in Germany. Cost for treatment of these stones amount to $687,000,000. Stone metaphylaxis reduces the recurrence rate by some 40%. The annual cost for stone removal could be lowered by $275,300,000. Metabolic evaluation/metaphylaxis amount to $70,100,000 per year, resulting in an net saving of $205,200,000. In 1997, there were 96 days off-work per stone patient resulting in 5,800,000 days off-work in Germany per year. Metaphylaxis in stone formers can lower health care cost significantly. Although health care conditions may vary from country to country, in principle this calculation model is applicable also to other countries.

Adult↗
PubMed1992

Composition of urinary calculi related to urinary tract infection.

The composition of 3,084 urinary calculi was determined using an infrared spectrophotometer. Mixed calcium oxalate-calcium phosphate stones were most frequently implicated. Of the urinary calculi analyzed 199 were associated with urinary tract infection. Escherichia coli was most frequently isolated (43 strains) and urease-producing organisms, such as Proteus mirabilis, were cultured from 40 patients. The core culture of 20 staghorn calculi yielded 15 isolates from 14 stones. There were 13 identical species isolated from the urine and stone specimens of 13 patients (65%), including 7 strains of P. mirabilis. These results suggest that cultures of urine specimens of urolithiasis patients, especially those with staghorn calculi, may help to elucidate the bacteriology of the stones.

Adolescent↗
PubMed2004

Water for preventing urinary calculi.

BACKGROUND: Urinary calculi is a common condition characterized of high incidence and high recurrence rate. For a long time, increased water intake has been the main preventive measure for the disease and its recurrence. OBJECTIVES: To access the effectiveness of increased water intake for the primary and secondary prevention of urinary calculi. SEARCH STRATEGY: Relevant RCTs were identified by electronic and documental searches of MEDLINE, EMBASE, the Chinese Biomedical Disk and the Cochrane Central Register of Controlled Trials. No language restriction was applied. Date of last search: May 2004. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs of increased water intake for the prevention of urinary calculi and its recurrence. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or weight mean difference (WMD) for continuous data with 95% confidence intervals (CI). MAIN RESULTS: No trials of increased water intake for the primary prevention of urinary calculi met the inclusion criteria. One trial with 199 patients provided results of increased water intake for the recurrence of urinary calculi. The recurrence rate was lower in the increased water intake group than that of the no intervention group (12% versus 27%, P = 0.008, RR = 0.45, 95% CI 0.24 to 0.84). The average interval for recurrences was 3.23 +/-1.1 years in increased water intake group and 2.09 +/- 1.37 years in the no intervention group (P = 0.016, WMD = 1.14, 95% CI 0.33 to 1.95). REVIEWERS' CONCLUSIONS: The evidence from only one trial indicates that increased water intake reduces the risk of recurrence of urinary calculi and prolongs the average interval for recurrences. However further research is required. Due to the lack of appropriate RCTs, no conclusions can be drawn on increased water intake for the primary and secondary prevention of urinary calculi.

Drinking↗
PubMed1976

A contribution to the formation mechanism of calcium oxalate urinary calculi. I. Stabilising urinary constituents in the formation of weddellite.

25 to 30% of calcium oxalate urinary calculi consist of the metastable Weddellite crystal phase. By fractionation of urine it was found that mineral substances are stabilising factors. The stability was checked in dry condition at room temperature at 38 degrees C and at 110 degrees C. These results could be confirmed by precipitation from synthetic solutions. Mg, Zn, Ni, Co, Mn and Cu individually, and above all in combination, promote the formation of Weddellite. The formation of mixed crystal phases must be considered one of the main factors for the stabilisation of Weddelite in the urinaty calculus.

Calcium↗
PubMed1989

[Investigation on the composition and structure of 400 urinary calculi].

400 urinary calculi have been analyzed by chemical and physical methods, namely chemical qualitative analysis, metallic elements spectrometry, X-ray diffraction, infrared spectroscopy, thermographimetric analysis, polarizing microscopy, scanning electron microscopy, etc. Further understanding of the correlation between the structure and the composition of calculi was achieved, which may be helpful in inquiring the formation of urinary calculi.

Calcium↗
PubMed1982

A multiple technique approach to the analysis of urinary calculi.

10 urinary calculi have been qualitatively and quantitatively analysed using X-ray diffraction, infra-red, scanning electron microscopy, X-ray fluorescence, atomic absorption and density gradient procedures. Constituents and compositional features which often go undetected due to limitations in the particular analytical procedure being used, have been identified and a detailed picture of each stone's composition and structure has been obtained. In all cases at least two components were detected suggesting that the multiple technique approach might cast some doubt as to the existence of "pure" stones. Evidence for a continuous, non-sequential deposition mechanism has been detected. In addition, the usefulness of each technique in the analysis of urinary stones has been assessed and the multiple technique approach has been evaluated as a whole.

Densitometry↗