Risk factors for urolithiasis in children on the ketogenic diet

Kidney stones have been associated with use of the ketogenic diet in children with refractory seizure disorders. We performed a case-control study examining risk factors for the development of stones on the ketogenic diet, and prospectively followed children initiating the ketogenic diet to evaluate the incidence of urolithiasis. Clinical characteristics of 18 children presenting with stones (8 uric acid stones, 6 mixed calcium/uric acid stones, 1 calcium oxalate/phosphate stone, 3 stones not evaluated) were compared with characteristics of non-stone-forming children initiating the ketogenic diet at Johns Hopkins since July 1996. Since July 1996, 112 children initiating the ketogenic diet have been followed for development of stones. Follow-up times on the diet range from 2 months to 2.5 years. Of 112 children, 6 have developed stones (3 uric acid, 3 mixed calcium/uric acid stones) (0.8 children developing stones/ 100 patient-months at risk). Comparisons of children presenting with stones on the ketogenic diet with characteristics of the entire cohort initiating the ketogenic diet suggest younger age at diet initiation and hypercalciuria are risk factors for the development of stones. Prospective evaluation of children initiating the ketogenic diet revealed that almost 40% of patients had elevated fasting urine calcium: creatinine ratios at baseline; this increased to 75% after 6 months on the diet. Median urine pH was 5.5 at diet initiation, and remained at 6.0 thereafter. In a subset of patients tested, urinary citrate excretion fell from a mean of 252 mg/24 h pre diet initiation to 52 mg/24 h while on the diet. Uric acid excretion remained normal. Patients maintained on the ketogenic diet often have evidence of hypercalciuria, acid urine, and low urinary citrate excretion. In conjunction with low fluid intake, these patients are at high risk for both uric acid and calcium stone formation. Received: 28 May 1999 / Revised: 7 June 2000 / Accepted: 9 June 2000     

Removal of kidney stones by extracorporeal shock wave lithotripsy is associated with delayed progression of chronic kidney disease

Purpose

This study aimed to elucidate whether stone removal by extracorporeal shock wave lithotripsy (ESWL) is associated with delayed chronic kidney disease (CKD) progression.

Materials and Methods

We conducted a retrospective analysis of 131 nephrolithiasis patients with stage 3 and 4 CKD. We collected baseline clinical and laboratory data, kidney stone characteristics, and history of receiving ESWL. We classified study patients into two groups according to whether they underwent ESWL or not (Non-ESWL group vs. ESWL group). We initially compared annual estimated glomerular filtration rate (eGFR) changes of Non-ESWL group with those of ESWL group before undergoing ESWL. In the next step, we sought to compare annual eGFR changes in the same patients before and after ESWL. Finally, we compared annual eGFR changes between success and failure groups among patients undergoing ESWL.

Results

The mean age of the patients was 62 years and 72.5% were male. The mean observation period was 3.2 years. Non-ESWL group and ESWL group before undergoing ESWL showed similar annual eGFR changes (-1.75±6.5 vs. -1.63±7.2 mL/min/1.73 m²/year, p=0.425). However, eGFR declined slower after undergoing ESWL than before ESWL (annual eGFR changes, -0.29±6.1 vs. -1.63±7.2 mL/min/1.73 m²/year, p<0.05). In addition, among patients in ESWL group, eGFR declined faster in the failure group than in the success group (annual eGFR change, -1.01±4.7 vs. -0.05±5.2 mL/min/1.73 m²/year, p<0.05).

Conclusion

Our results suggest that stone removal by ESWL is associated with delayed deterioration of renal function in CKD patients with nephrolithiasis.     

Normocalcemic primary hyperparathyroidism in patients with recurrent kidney stones: pathological analysis of parathyroid glands

The lack of overt elevation of serum calcium concentration in some patients suffering from primary hyperparathyroidism is an intriguing clinical phenomenon. Previous studies have substantiated abnormal parathyroid tissue in these patients, but the extent and mode of derangements remained largely undefined. The parathyroid tissues from patients of normocalcemic primary hyperparathyroidism (NCPHPT) and those having normal parathyroid glands, hypercalcemic primary hyperplasia, secondary hyperplasia, and adenoma were compared by undertaking quantitative immunohistochemistry analysis on tissue microarray. The statistic results suggested that the parathyroid tissue of NCPHPT approximates more to normal gland than to its counterpart in other groups of parathyroid proliferative diseases in terms of the lack of significant alterations of calcium-sensing receptor (CaSR), chromogranin A (CGA), parathyroid hormone (PTH), and proliferation index (Ki67). On the other hand, the depressed vitamin D receptor (VitDR) and elevated cyclin D1 (CyD1) of NCPHPT indicated the inherent functional abnormalities in parathyroid cells. Our results imply that inherent functional disengagement may exist between CaSR and CyD1 or between CaSR and VitDR or both in parathyroid cells of symptomatic NCPHPT. Lack of enhanced release of CGA and PTH and discordance between proliferative activity and CyD1 expression in parathyroid cells may further hinder the development of hypercalcemia.     

Case-referent study on occupational risk factors for bladder cancer in southern Israel

Objective: To evaluate the possible association between occupational exposures (risk factors) and male bladder cancer in the Negev region (southern Israel) to enable preventive strategies to be applied. Methods: A total of 92 male bladder cancer patients, diagnosed at a regional medical center between 1989 and 1993, were studied by interview and compared with 92 males without oncological disease after matching by age and country of origin. A special questionnaire was developed to gather information on demography, life-time occupational history, smoking habits, coffee consumption, and health status. Statistical analysis of the case-referent data was done using the SPSS-5 package for performance of the chi-square test, conditional logistic regression, and multiple classification analysis. Results: Significant associations were found between bladder cancer occurrence and (1) three different groups of occupational exposures [a – solvents (P = 0.002, OR not computed due to the lack of exposed persons among referents), b – dusts (P = 0.02; OR = 4.67), and c – exposure to multiple chemicals (P < 0.001, OR = 6.25); (2) nephrolithiasis (P = 0.02, OR = 11.00); and (3) cigarette smoking (P = 0.01, OR = 1.87). Conclusions: Certain types of occupational exposure, different from that to aromatic amines and dyes, may be considered as contributing factors in the epidemiology of bladder cancer. Better identification of these chemicals and the work processes where they are used may help in abating such exposures, thus leading to a reduction in the risk for this relatively common cancer. Received: 6 April 1998 / Accepted: 16 January 1999     

纤维连接蛋白基因型多态性与草酸钙肾结石相关性研究

目的:探讨纤维连接蛋白基因(FN)型多态性与草酸钙肾结石的关系。方法:用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法,检测所有研究对象的FN第2内含子rs10202709位点及第26内含子rs35343644位点的基因型,探讨其基因型与草酸钙肾结石的关系。结果:FNAA基因型与草酸钙肾结石的发病率相关(P<0.05),未发现其他基因型与草酸钙肾结石有相关性。结论:FN基因型多态性与草酸钙肾结石有相关性,FN的AA基因型可作为肾结石患者草酸钙结石危险因素的标志。     

<Emphasis Type="Italic">Cynodon dactylon</Emphasis> extract as a preventive and curative agent in experimentally induced nephrolithiasis

Cynodon dactylon (Poaceae family) decoction was used in the treatment of kidney stones. However, no scientific study was undertaken so far to demonstrate the beneficial effect of the plant. Thus, the aim of the current study is to evaluate the effect of Cynodon aqueous extract as a preventive and curative agent in experimentally induced nephrolithiasis in a rat model. Ethylene glycol (EG) was used in the experiment to induce calcium oxalate (CaOx) deposition into kidneys. In preventive protocol, Cynodon decoction was administered in the same day with EG to evaluate the ability of the extract to prevent crystal deposition. However, in curative protocol, rats were first rendered nephrolithiasic and then the extract was administered to assess the ability of the plant to eliminate the pre-existing crystal deposition. In both protocols, urinary biochemical and other variables were measured during the course of the study. Crystalluria and renal histology were examined as well. The results showed that, in both protocols, all measured variables were similar for both the rat groups. Nevertheless, urinary biochemical analysis was apparently unaffected by the extract except oxalate in preventive protocol, and calcium, sodium, and potassium in curative protocol which were significantly highly excreted in treated rats compared to untreated animals. Crystalluria was characterized mostly by the presence of large quantities of CaOx monohydrate and CaOx dihydrate particles in untreated rats. However, crystalluria was mainly dominated by the presence of CaOx dihydrate particles with reduced size. The most apparent beneficial effect of Cynodon extract was seen in kidney tissues where reduced levels of CaOx deposition have been noticed especially in medullary and papillary sections from treated rats. We concluded that C. dactylon extract has beneficial effect in preventing and eliminating CaOx deposition into kidneys. Such findings provide a scientific explanation for its use in the treatment of kidneys stones.     

Can the Stone Scoring Systems Be Used to Predict Infective Complications of Retrograde Intrarenal Surgery?

ObjectiveWe aimed to evaluate whether the retrograde intrarenal surgery (RIRS) scoring systems (Resorlu-Unsal Stone Score [RUSS], modified Seoul National University Renal Stone Complexity Score [modified S-ReCS], and R.I.R.S. score) can predict the infective complications after RIRS.Subject and MethodsA total of 581 patients who underwent RIRS for kidney stones were included in the study. All patients were evaluated for demographic data, medical history, radiological imaging methods before surgery, duration of surgery, and hospitalization time after surgery. Stone laterality, stone burden, stone size, stone density, the number of stones, stone localization, the presence of congenital kidney anomaly, and solitary kidney were evaluated preoperatively by computed tomography. The RUSS and modified S-ReCS and R.I.R.S. score of all patients were determined.ResultsInfective complications were detected in 47 (8.1%) patients who underwent RIRS. Fever developed in 27 subjects (4.6%), urinary infection in 15 (2.5%), sepsis in 2 (0.3%), and septic shock in 3 (0.5%) patients. In multivariate logistic regression analysis, age (OR = 1.8; 95% CI = 1–3.4; p = 0.049), surgical duration of >60 min (OR = 1.9; 95% CI = 1.1–3.5; p = 0.027), and high R.I.R.S score (OR = 8.9; 95% CI = 1.9–42.4; p = 0.006) were shown to be independent risk factors for the infective complications after RIRS. A receiver operating characteristic curve analysis showed that the R.I.R.S. score can be used as a marker to predict infective complications (AUC = 0.619, CI = 0.55–0.69; p = 0.007).ConclusionWe suggest that the R.I.R.S. score can be used to predict infective complications in RIRS.     

超声引导下经皮肾穿刺钬激光碎石术治疗肾结石的价值

目的 探讨超声引导下建立皮肤肾脏通路,进行经皮肾穿刺钬激光碎石术（pereutaneous nephrolithotomy,PCNL）的安全性和有效性。方法2007年1月到2008年1月采用术中B超引导下,进行穿刺建立通路,行PCNL术治疗肾结石患者53例,并记录结石取净率及手术并发症。结果53例患者均一期成功建立皮肤肾脏通路,52例行一期碎石术,1例行二期碎石术。所有患者术后无气胸、腹腔脏器损伤等严重并发症发生。术后复查,45例患者排净结石,8例有结石残余,结石清除率为84．91％。结论采用B超引导行PCNL术治疗肾结石安全、方便,疗效可靠,