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At least 19 recordsLinked to original sources
PubMed1979

Composition of renal stones and their frequency in a stone clinic: relationship to parameters of mineral metabolism in serum and urine.

Stone analyses (kidney, upper urinary tract) of the department of Urology, University of Erlangen, from a four-year-period (1974-1977) have been recorded with emphasis to stone composition, sex and age of the pertinent stone forming patients. During this time period there were no substantial changes as regards the per cent frequency of the various stone types. The most frequent type was calcium oxalate (CaOx), followed by uric acid, calcium phosphate (CaP), struvite and cystine. Stone analyses were mostly requested for patients between 46 and 55 years of age. Stone incidence in our clinic is calculated to be 1.22 times higher in males than females, especially beyond 36 years of age. The frequency peaks are: pure (= 100 per cent) CaOx 36-45 years; CaOx with additional mineral phases (mostly CaP) 46-55 years; uric acid 56-65 years; CaP 26-35 years. From those patients who underwent further investigations in searching for metabolic abnormalities serum concentrations, urine mineral clearances in fasting urine samples, and activity products of stone forming mineral phases in sequentially collected specimens from 24 h and 2 h fasting urine had been measured and compared with values from healthy control subjects. In urolithiasis (idiopathic) there is a normal parathyroid hormone blood level, a generally lower serum inorganic phosphate and magnesium concentration. In pure (= 100 per cent) CaOx and uric acid lithiasis serum uric acid and creatinine are higher than in controls, urine pH and calcium clearance in some groups are different too. Clearances of magnesium, uric acid, phosphate, sodium are within normal limits in urolithiasis. When expressing the propensity to form stones in terms of activity products, then only uric acid lithiasis deviates substantially from normal. All other stone types differ only slightly or not at all from each other and controls respectively. It is concluded that 1) in our geographic region the various stone types prevail in different age periods; 2) there are distinct alterations of parameters of mineral metabolism in urolithiasis; 3) measuring urine clearances may lead to assume falsely normal mean urine excretion of stone forming constituents.

Adolescent↗
PubMed1975

Influence of stone mixing agents, impression materials and lubricants on surface hardness and dimension of a dental stone die material.

The influence of different stone mixing agents, impression materials and lubrication methods on the surface hardness of a stone die material has been evaluated. For one impression material the dimensional effect of the mixing agents and lubrication on the dies was also studied. The stone die material was mixed with water or a gypsum hardener and allowed to set on surfaces of glass, agar-agar, polyether, polysulfide and silicone impression materials. The lubrication methods for the stone were mineral oil, water soluble lubricant and mineral oil followed by water soluble lubricant. The surface hardness was measured according to the Brinell test. The Brinell test was chosen after a comparative study of the Brinell, Vickers and Knoop hardness test methods. The results showed that gypsum hardener was preferable to distilled water. The impression materials appear to have influence on the surface hardness of stone. The effect differed on water mixed and hardener mixed stone which emphasizes the importance of the mixing agent. All lubrication decreased the surface hardness of stone. With hardener mixed stone the combination of mineral oil followed by water soluble lubricant seemed preferable. Neither the gypsum hardener nor the lubrication influenced the dimension of the stone die material.

Dental Impression Materials↗
PubMed2026

Novel non-contrast computed tomography parameters for predicting spontaneous stone passage and surgical requirement in ureteral stones: The role of ureteral wall thickness and dilatation ratio.

We investigated the predictive value of standard non-contrast computed tomography (NCCT) measurements, the ureteral dilatation ratio (DDR) and intraluminal urine stasis markers, for spontaneous stone passage (SSP) versus surgical intervention in patients with ureteral stones. We also evaluated ureteral wall thickness (UWT) as a practical clinical marker. This retrospective study included 461 patients diagnosed with ureteral stones via NCCT. Patients were categorised into two groups based on clinical outcomes: the spontaneous passage group (MET; n&#x2009;=&#x2009;229) and the endoscopic surgery group (URS; n&#x2009;=&#x2009;232). Stone volume, stone density (HU), UWT, DDR and intraluminal urine attenuation values were measured for all patients. Independent risk factors were identified using a multivariate logistic regression model and clinical cut-off values were determined via ROC curve analysis. Stone volume, density, UWT and hydronephrosis grade were all significantly higher in the URS group. Multivariate regression analysis revealed that increased UWT (OR: 5.03, 95% CI: 3.66-6.90; p&#x2009;<&#x2009;0.001) was the strongest independent predictor of surgery. Higher DDR (OR: 1.88; p&#x2009;=&#x2009;0.003), advanced hydronephrosis, stone volume, and density also increased surgical risk. A UWT cut-off &#x2265;&#x2009;2.97&#xa0;mm predicted surgery with 84.8% sensitivity and 84.3% specificity (AUC: 0.872). A DDR cut-off >&#x2009;1.79 yielded 81.7% specificity and 40.4% sensitivity. UWT weakly correlated with stone volume (r&#x2009;=&#x2009;0.145), indicating wall thickening reflects an inflammatory response rather than a mere mechanical consequence. UWT is a superior predictor of SSP failure, supported by increased DDR as a highly specific complementary risk factor. These parameters could help clinicians to identify patients who would benefit from early surgical counselling and intervention rather than prolonged conservative management.

Humans↗
PubMed1979

Family history of renal stones in a population study of stone-formers and health subjects.

Information on the family history of renal stone disease was obtained from over 2500 middle-aged men in a general health survey. A family history of stones was significantly more common among the stone-formers than amoung the controls, largely due to an increased frequency of stones among the fathers and brothers of the propositi. This study thus supports previous suggestions that genetic factors play a part in the predisposition to stone formation. An increased tendency was also noted, however, among the wives of those whose relatives had stones, which suggests that environmental factors are involved. Subjects with a family history of renal stones did not exhibit any particular characteristics in their laboratory profiles, but they appeared to be more prone to develop early and frequent recurrences.

Adult↗
PubMed1978

Retained intrahepatic stones. Use of the U tube during repeated nonoperative stone extractions.

Of 355 patients undergoing nonoperative extraction procedures for retained bile duct stones, 61 patients had intrahepatic calculi. In seven of these patients with multiple intrahepatic stones and two of them with additional hepatic duct strictures.trahepatic stones, a U tube was placed. Insertion of a U tube is particularly useful if multiple sittings are required for intrahepatic stone removal. The U tube can be inserted postoperatively and permits ease of operation from two sides, particulary if stricture dilation is required before stone removal. With the use of the U tube, inadvertent removal has not occurred and patients are able to work and shower between extraction procedures. Indwelling U tubes are readily replaced over a guide wire. This technique was used with good success and for long periods of time in seven patients, all with multiple intrahepatic stones and two of them with additional hepatic duct strictures.

Bile Ducts, Intrahepatic↗
PubMed1978

Recurrent common duct stones, with special reference to primary common duct stones.

A series of 1,358 cholelithic patients operated on at 32 affiliated hospitals during the last year and 492 patients operated on at authors' hospital during the last 21 years were reviewed with special reference to the cases of recurrent common duct stones. Of the former series 15 patients and of the latter series 12 patients respectively were reoperated on for recurrent, but not for residual, common duct stones, and all of them had in the markedly dilated common duct bilirubin stones showing characteristics of stasis stone-primary in common duct. Two representative cases are presented briefly. Congenital hypotonia of the common duct and inflammatory choledochitis are condemned and bilioenterostomy is recommended for preventing stone recurrences.

Bilirubin↗
PubMed1979

On the pathogenesis of stone formation in stone-eliminating patients.

The clinical peculiarities, and the etiological and pathogenetic factors of urolithiasis in 296 patients suffering from spontaneous stone elimination were studied. It was established that 209 patients eliminated stones consisting of uric acid, sodium salts and ammonium salts. Moderate hypocalcemia and hyperphosphatemia and also hyperuricemia and hyperuricuria were present. There were 39 'eliminators' of calcium stones. Their blood calcium content was higher, hypercalciuria, inorganic phosphorus and normal uric acid, were noted. Compound stones were present in 48 observations. When carrying out additional biochemical tests in 57 patients with calcium and compound stones, primary hyperparathyroidism was diagnosed in 34 observations; and parathyroidectomy was successfully performed.

Adult↗
PubMed1975

[Influence of efferent biliary ducts on the composition of bile acids. Studies on subjects with cholesterol gall stones and a stone-free control group].

Cadaveric livers and their gall bladders were used in order to determine the bile acids following separation by thin layer chromatography; spectrophotofluorimetry was employed. In the hepatic tissue of the lithiasis patients the bile acid concentrations and the ratio of the trihydroxycholanic acid (cholic acid) to the dihydroxycholanic acids (desoxycholic acid and chenodesoxycholic acid) are lower than in the control group. In the B-bile only cholic acid and the quotient cholic acid to chenodesoxycholic acid reveal any significant differences. Also, there exists an established positive correlation between the bile acid concentration in the hepatic tissue and in the B-bile of the alcoholic test persons but not in the cholelithiasis patients. From this we may infer that the concomitant inflammation of the gall bladder has an influence on the composition of the bile acids.

Autopsy↗
PubMed2025

Outcome of conservative management of small renal stones in prepubertal children.

INTRODUCTION: Renal stones are relatively uncommon in the pediatric population. This study aimed to evaluate the utility of conservative management of small renal stones in prepubertal children. PATIENTS AND METHODS: A retrospective chart review was conducted for children (&#x2264;12 years old) with small renal stones (3-10 mm) from 2016 to 2023 who underwent conservative management. Management included periodic renal ultrasonography, every 6 months, in addition to good hydration. Stones were confirmed by two consecutive ultrasounds. We recorded the patient's demographics and ultrasound findings (stone side, size, laterality, location, number, and associated hydronephrosis). Surgical intervention was indicated if recurrent loin pain, recurrent UTI, or worsening hydronephrosis (obstructing stone). Nephrolithiasis was considered resolved if stones were not visualized on 2 consecutive ultrasounds. Moreover, we evaluated conservative management outcomes for those presented during infancy (<12 months) versus later. RESULTS: We included 52 patients (65renal units) who presented at a median age of 46.1months (5.3-155.1). Seventy-five percent of patients had incidental renal stones. The median stone size was 4 mm (3-10). Forty-six percent of stones were in the lower calyx. The majority (70.8 %) had no hydronephrosis at presentation. During a median follow-up of 39months, 15patients with 17units (26.2 %) were documented stone-free. Ten patients (19.2 %) had symptomatic stone events, all measured &#x2265;4 mm. Of them, 6 patients (6 units) underwent surgical interventions, and 4 patients (4 units) experienced complications. A ROC curve analysis identified a stone size cutoff of 4 mm (sensitivity 100 % and 29 % specificity) that could be associated with symptomatic stone events. Using a multivariate Cox regression model, stone size was the only significantly associated factor with subsequent surgical intervention (p = 0.007). 19 % (10patients,12units) presented during infancy. Notably, the incidence of stone-free rate was significantly higher during infancy compared to older children (58.3 % vs 18.9 %,respectively). DISCUSSION: During a 39-month follow-up, 4 patients developed complications (2recurrent pain and 2 experienced UTI), supporting the safety of conservative management of small renal stones. This study is limited due to its retrospective design and the reliance on ultrasound as the main imaging method. To minimize that, all ultrasound images were carefully reviewed by two pediatric urologists. Moreover, renal stones were confirmed using strict criteria, which required detection in two consecutive ultrasounds. CONCLUSION: Although 26.2 % of units had spontaneously resolved nephrolithiasis, surgical intervention was only required in 11.5%of patients, all of whom had renal stones&#x2265;4 mm. Infants had higher spontaneous resolutions without complications, suggesting that conservative management may be especially effective in this subgroup.

Humans↗