Explore the vast range of titles available.

Complications after renal allograft transplantation are not so uncommon. Most complications are related to graft rejection, immune-suppressive drug toxicity and the operative procedure. Stents are placed after a transplant to prevent urine leak at the site of ureteric reimplantation, to facilitate an early healing in immune-suppressed individuals and to prevent obstruction at the site of ureteral anastomosis. We report a case of a renal allograft recipient with a forgotten ureteral double J stent. where the stent remained in situ for more than 4 years and further complicated by encrustation and stone formation at both the bladder and renal pelvic ends. The stone over the bladder coil was removed by holmium laser cystolithotripsy while the encrusted renal pelvic coil was removed by percutaneous approach. This case is presented for its rarity and also to emphasise on the need for maintenance of a stent register in order to ensure avoidance of such preventable complications.

Introduction Stone analysis is an important part in the evaluation of patients having stone disease. This could orientate the physician toward particular etiologies. Material and methods Chemical and physical methods are both used for analysis. Unfortunately, chemical methods often are inadequate to analyze accurately urinary calculi and could fail to detect some elements into the stone. Physical methods, in counterpart, are becoming more and more used in high-volume laboratories. The present manuscript will provide a review on analytic methods, and review all the information that should be included into an appropriate morpho-constitutional analysis. Conclusion This report can supply an excellent summarization of the stone morphology and give the opportunity to find specific metabolic disorders and different lithogenic process into the same stone. Here, specific chemical types with their different crystalline phases are shown in connection with their different etiologies involved.

The recent epidemic of melamine-contaminated formula in China has been associated with urinary tract stones. The authors of this study screened 589 consecutively enrolled children; 421 had received formula contaminated by melamine. In all, 50 had urinary stones, 112 were suspected to have stones, and 427 did not have stones. Affected children lacked typical signs and symptoms of urolithiasis. Exposure to melamine-contaminated formula and prematurity were associated with the presence of stones. The authors screened children who had received formula contaminated by melamine. Exposure to melamine-contaminated formula and prematurity were associated with the presence of urinary stones. An epidemic of urinary tract stones in young children, most under 36 months of age, recently occurred in China. On September 12, 2008, the Chinese government announced that the epidemic was most likely related to melamine contamination of powdered-milk formula for infants, and a policy of free screening for urinary stones in children was instituted. The addition of melamine to food boosts the apparent protein content, since melamine contains 66% nitrogen by mass; this covert practice appears to have been the cause of the melamine contamination of infant formula. Although an epidemic of renal failure, including some deaths, had occurred . . .

This study aimed to observe the effect of the location and severity of partial ureteral obstruction, based on ureteropelvic and ureterovesical junction strictures, on stone formation. Forty 8-week-old male rats were divided into five groups: control and mild/severe proximal or distal ureteral obstruction groups. A partial ureteral obstruction was created according to the type of obstruction by a surgical procedure. After 5 days of intraperitoneal glyoxylate injection, the urine, blood samples, and kidney tissues of the rats were examined. There were significant differences in urine citrate concentrations, pH values, and oxalate/creatinine, citrate/creatinine, and calcium/creatinine ratios between the groups (all p  < 0.05). The mean citrate/creatinine ratio was 21.13 ± 0.44 in the control group, 17.31 ± 3.82 in the distal obstruction group, and 15.48 ± 1.87 in the proximal obstruction group. Regarding the degree of obstruction, urine citrate concentrations, pH values, and citrate/creatinine were lower, and the oxalate/creatinine ratio was higher in severe obstruction than in mild obstruction ( p  < 0.05). This study represents an initial attempt to evaluate a model of partial ureteral obstruction and urolithiasis. The findings indicate that obstruction alters urinary parameters, such as citrate and pH, indirectly increasing the risk of stone formation. Furthermore, stone formation in an obstructed urinary system appears to be a complex process. However, metabolic evaluation and treatment may help prevent stone formation in patients with ureteral obstruction.

Hypouricemia was reported as a risk factor for exercise-induced acute renal injury (EIAKI) and urinary stones. However, the prevalence of kidney diseases among hypouricemic subjects has not been evaluated. This study was conducted to clarify the prevalence of hypouricemia and the association of hypouricemia with kidney diseases by using a large-scale Japanese population data. This study is a retrospective cross-sectional study at the Center for Preventive Medicine, St. Luke's International Hospital, Tokyo, Japan, and Sanin Rousai Hospital, Yonago, Japan. We analyzed the medical records of 90,143 Japanese subjects at the center in St. Luke's International Hospital, Tokyo, and 4,837 subjects in Sanin Rousai Hospital, Yonago, who underwent annual regular health check-up between January 2004 and June 2010. We defined hypouricemia as serum uric acid level of ≤2.0 mg/dL. We checked the medical history of all the study subjects and compared the rates of complications including urinary stones and kidney diseases among those with or without hypouricemia. The prevalence of hypouricemia was 0.19% in St. Luke's International Hospital, Tokyo, and 0.58% in Sanin Rousai Hospital, Yonago. The prevalence of hypouricemia in women was larger than that in men both in Tokyo (0.31% vs 0.068%, p<0.001) and in Yonago (1.237% vs 0.318%, p<0.001). Among 172 hypouricemic subjects (30 men), the rates of previous urinary stones and kidney diseases (including nephritis/nephrosis) were 1.2% (3.3% men, 0.7% women) and 2.3% (10% men, 0.7% women), respectively. Hypouricemic men had a 9-fold higher rate of previously having kidney diseases compared to non-hypouricemic men (p<0.001). However, the rates of other diseases including urinary stones were not significantly different between the two groups. Hypouricemia was associated with a history of kidney disease especially in men.

BackgroundPediatric urinary stone disease (USD) is a costly medical problem. This study aims to assess the clinical characteristics and outcomes of common and rare causes of pediatric USD.MethodsA retrospective descriptive cohort study included all children < 13 years of age with confirmed USD admitted to the Children’s University Hospital in Damascus, Syria, from January 2013 to December 2019. The study sample was divided into two groups based on etiologies: common and rare causes groups.ResultsWe evaluated 235 patients; 147 of them were males, and the male-to-female ratio was 1.7:1. The common causes group consisted of 203 patients (mean age 3.52 ± 3.66 years) and mainly included metabolic disorders (45.5%) and anatomical abnormalities (22.3%), while the rare causes group included 32 cases (mean age 4.93 ± 4.08 years), 12 patients with uric acid stones (37.5%), 7 patients with cystinuria (21.9%), and primary hyperoxaluria in 5 patients (15.6%). In addition, 39.6% of study patients were born to consanguineous marriages. Sixty-two patients developed AKI, and eleven patients had chronic kidney disease (CKD). Patients with rare causes were more likely to have AKI, CKD, bilateral stones, and recurrent stones (P-value < 0.05). Stone analysis was performed on 83 patients, and the main stone types were calcium oxalate (34.9%), uric acid (14.4%), and struvite stones (12%). Surgery was the most performed treatment in 101 patients (56.7%).ConclusionPatients with rare causes of pediatric USD are at a higher risk for severe complications and require early diagnosis and management. The high rate of uric acid stones in our society requires further evaluation for possible underlying causes.

The study is aimed to establish a predictive model of double-J stent encrustation after upper urinary tract calculi surgery. We collected the clinical data of 561 patients with indwelling double-J tubes admitted to a hospital in Shandong Province from January 2019 to December 2020 as the modeling group and 241 cases of indwelling double-J tubes from January 2021 to January 2022 as the verification group. Univariate and binary logistic regression analyses were used to explore risk factors, the risk prediction equation was established, and the receiver operating characteristic (ROC) curve analysis model was used for prediction. In this study, 104 of the 561 patients developed double-J stent encrustation, with an incidence rate of 18.5%. We finally screened out BMI (body mass index) > 23.9 (OR = 1.648), preoperative urine routine white blood cell quantification (OR = 1.149), double-J tube insertion time (OR = 1.566), postoperative water consumption did not reach 2000 ml/d (OR = 8.514), a total of four factors build a risk prediction model. From the ROC curve analysis, the area under the curve (AUC) was 0.844, and the maximum Oden index was 0.579. At this time, the sensitivity was 0.735 and the specificity was 0.844. The research established in this study has a high predictive value for the occurrence of double-J stent encrustation in the double-J tube after upper urinary tract stone surgery, which provides a basis for the prevention and treatment of double-J stent encrustation.

The purpose of these studies was to test the hypothesis that Randall's plaque develops in unique anatomical sites of the kidney and their formation is conditioned by specific stone-forming pathophysiologies. We performed intraoperative papillary biopsies from kidneys of idiopathic-calcium oxalate (CaOx), intestinal bypass for obesity, brushite (BR) and cystine stone formers (SF) during percutaneous nephrolithotomy. Tissues were examined by infrared analysis and light and electron microscopy. Our analysis revealed a distinct pattern of mineral deposition and papillary pathology for each type of SF. CaOx SF had interstitial apatite crystals beginning at thin loops of Henle. These deposits termed Randall's plaque are thought to serve as sites for stone attachment. No tubular injury was noted. Intestinal bypass patients possessed intraluminal apatite deposits in inner medullary collecting ducts (IMCD) with associated cell injury. BR SF showed the most severe form of cortical and medullary changes with sites of Randall's plaque, and yellowish intraluminal deposits of apatite in IMCD. Cystine SF had plugging of ducts of Bellini with cystine crystals and apatite deposits in IMCD and loops of Henle. Intratubular sites of crystalline deposits were always associated to adjacent regions of interstitial fibrosis. The metabolic, anatomic, and surgical pathologic findings in four distinct groups of SF clearly show that ‘the histology of the renal papilla from a stone former, is particular to the clinical setting’. We believe our approach to studying stone disease will provide insights into the pathogenesis of stone formation for each type of SF that will lead to improved clinical treatment.

To evaluate the efficacy and safety of the use of Ningmitai capsule as an adjunctive stone expulsion therapy after RIRS. All patients were diagnosed with upper urinary tract calculi measuring 10–20 mm. The patients who successfully underwent RIRS were randomly assigned to the NMT capsule group (Ningmitai capsule, 1.52 g, three times daily) or the control group for 4 weeks based on the random number table method. The primary endpoints were the stone expulsion rate (SER) and stone-free rate (SFR). The average stone expulsion time (SET), average stone-free time (SFT) and complications were recorded. Between July 2, 2019, and December 17, 2020, 220 participants successfully underwent RIRS across 6 centers; 123 of them were randomized according to the exclusion criteria, and 102 (83%) were included in the primary analysis. The SERs on the 3rd, 7th, 14th and 28th days were significantly increased in the NMT capsule group compared with the control group (78.95% vs. 31.11%, 92.98% vs. 55.56%, 94.74% vs. 64.44%, 100% vs. 82.22%, respectively, p < 0.05). The SFRs on the 3rd and 7th days were not different (p > 0.05), while those on the 14th and 28th days were higher in the NMT capsule group (63.16% vs. 24.44% and 92.98% vs. 68.89%, p < 0.05). The average SET and average SFT of the NMT capsule group were remarkably shorter than those of the control group (p < 0.001). During the follow-up period, there were no significant differences in urine RBC counts between the two groups (p > 0.05). The urine WBC counts of the NMT capsule group were significantly lower than those of the control group on the 14th day (p = 0.011), but there was no difference on the 3rd, 7th or 28th day (p > 0.05). The analgesic aggregate of the NMT capsule group was also much lower (p = 0.037). There were no significant differences in adverse events (p > 0.05), and they improved significantly without sequelae. This study indicated that NMT capsules can significantly promote stone clearance and are more effective and safer for upper urinary calculi after RIRS.Trial registration Chinese Clinical Trial Registration No. ChiCTR1900024151.Date of registration June 28, 2019.

Urine proteins are thought to control calcium oxalate stone formation, but over 1000 proteins have been reported in stone matrix obscuring their relative importance. Proteins critical to stone formation should be present at increased relative abundance in stone matrix compared to urine, so quantitative protein distribution data were obtained for stone matrix compared to prior urine proteome data. Matrix proteins were isolated from eight stones (> 90% calcium oxalate content) by crystal dissolution and further purified by ultradiafiltration (> 10 kDa membrane). Proteomic analyses were performed using label-free spectral counting tandem mass spectrometry, followed by stringent filtering. The average matrix proteome was compared to the average urine proteome observed in random urine samples from 25 calcium oxalate stone formers reported previously. Five proteins were prominently enriched in matrix, accounting for a mass fraction of > 30% of matrix protein, but only 3% of urine protein. Many highly abundant urinary proteins, like albumin and uromodulin, were present in matrix at reduced relative abundance compared to urine, likely indicating non-selective inclusion in matrix. Furthermore, grouping proteins by isoelectric point demonstrated that the stone matrix proteome was highly enriched in both strongly anionic (i.e., osteopontin) and strongly cationic (i.e., histone) proteins, most of which are normally found in intracellular or nuclear compartments. The fact that highly anionic and highly cationic proteins aggregate at low concentrations and these aggregates can induce crystal aggregation suggests that protein aggregation may facilitate calcium oxalate stone formation, while cell injury processes are implicated by the presence of many intracellular proteins.