Zanlin Mai

A Prospective, Randomised Trial Comparing Plasmakinetic Enucleation to Standard Transurethral Resection of the Prostate for Symptomatic Benign Prostatic Hyperplasia: Three-year Follow-up Results

BACKGROUND Plasmakinetic enucleation of the prostate (PKEP) has recently been proved a safe and technically feasible procedure for benign prostatic hyperplasia (BPH). However, its long-term safety, efficacy, and durability in comparison with the gold-standard transurethral resection of the prostate (TURP) have not yet been reported. OBJECTIVE To report the 3-yr follow-up results of a prospective, randomised clinical trial comparing PKEP with standard TURP for symptomatic BPH. DESIGN, SETTING, AND PARTICIPANTS A total of 204 patients with bladder outflow obstruction (BOO) secondary to BPH were prospectively randomised 1:1 into either the PKEP group or the TURP group. INTERVENTION The patients in each group underwent the procedure accordingly. MEASUREMENTS All patients were assessed perioperatively and followed at 1, 3, 6, 12, 18, 24, and 36 mo postoperatively. The preoperative and postoperative parameters included International Prostate Symptom Score (IPSS), quality of life (QoL) scores, the International Index of Erectile Function (IIEF) questionnaire, maximum urinary flow rates (Q(max)), transrectal ultrasound (TRUS)-assessed prostate volume, postvoid residual urine (PVRU) volume, and serum prostate-specific antigen (PSA) level. Patient baseline characteristics, perioperative data, and postoperative outcomes were compared. All complications were recorded. RESULTS AND LIMITATIONS PKEP was significantly superior to TURP in terms of the drop in haemoglobin (0.74±0.33 g/dl vs 1.88±1.06 g/dl; p<0.001), intraoperative irrigation volume (11.7±4.5 l vs 15.4±6.2 l; p<0.001), postoperative irrigation volume and time (18.5±7.6 l vs. 30.0±11.4 l and 16.6±5.2 h vs 25.3±8.5 h; all p<0.001), recovery room stay (67.3±11.1 min vs 82.0±16.4 min; p<0.001), catheterisation time (51.7±26.3 h vs 80.5±31.6 h; p<0.001), hospital stay (98.4±20.4 h vs 134.2±31.5 h; p<0.001), and resected tissue (56.4±12.8 g vs 43.8±15.5 g; p<0.001). There were no statistical differences in operation time and sexual function between the two groups. At 36 mo postoperatively, the PKEP group had a maintained and statistically significant improvement in IPSS (2.4±2.2 vs 4.3±2.9; p<0.001), QoL (0.6±0.5 vs 1.6±1.4; p<0.001), Q(max) (28.8±10.1 ml/s vs 25.1±8.0 ml/s; p=0.017), and TRUS volume (21.0±7.3 ml vs 26.4±6.8 ml; p<0.001), with urodynamically proven deobstruction (Schäfer grade 0.2±0.02 vs 0.8±0.1; p<0.001). More extensive clinical trials are required to validate these results. CONCLUSIONS PKEP is a safe and highly effective technique for relieving BOO. At 3-yr follow-up, the clinical efficacy of PKEP is durable and compares favourably with TURP.

Minimally Invasive Percutaneous Nephrolithotomy for Simple and Complex Renal Caliceal Stones: A Comparative Analysis of More Than 10,000 Cases

PURPOSE To determine whether minimally invasive PCNL (MPCNL) is as safe and effective in the management of complex renal caliceal stones as it is for simple renal stones. PATIENTS AND METHODS We retrospectively reviewed 5761(41.2%) simple caliceal stones (isolated renal pelvis including isolated calix) and 8223 (58.8%) complex caliceal stones (renal pelvis accompanying two calices at least) that were managed by MPCNL between 1992 nd 2011. The safety, efficacy, and outcome were compared and analyzed. RESULTS Stone burden was larger in complex caliceal stones (1763.0 vs 1018.6 mm(2), P<0.05). Patients with simple stones had significantly shorter operative time, less frequency of multiple percutaneous accesses, and less hemoglobin drop. They also had a higher initial stone-free rate (SFR) (77.6% vs 66.4%) after a single session of MPCNL (P<0.05). The differences diminished in the final SFR (86.7% vs 86.1%) after relook and/or auxiliary procedures (P>0.05). The complication rate (17.9% vs 19.0%) and blood transfusion rate (grade II) (2.2% vs 3.2%) were similar in both groups (P>0.05). Both groups had a low rate of high Clavien grade complications. Renal vascular embolizations (grade III), however, were significantly higher in patients with complex caliceal stones (P<0.05). CONCLUSIONS MPCNL is a safe and effective treatment option for patients with complex caliceal stones except there is a slightly higher frequency rate of embolization. There was a higher initial SFR in simple stones, but this difference diminished with secondary procedures.

Prevalence of kidney stones in China: an ultrasonography based cross-sectional study

To investigate the prevalence and associated factors of kidney stones among adults in China.

Collection and storage of urine specimens for measurement of urolithiasis risk factors.

OBJECTIVE To evaluate how different methods for storage and preservation of urine samples affected the outcome of analysis of risk factors for stone formation. METHODS Spot urine samples were collected from 21 healthy volunteers. Each fresh urine sample was divided into ten 10-mL aliquots: 2 without preservative, 2 with thymol, 2 with toluene, 2 with hydrochloric acid (HCl), and 2 with sodium azide. One sample of each pair was stored at 4 °C and the other at room temperature. The concentrations of calcium, magnesium, sodium, phosphate, urate, oxalate, citrate, and pH in each urine sample were analyzed immediately after collection (0 hour) and after 24 and 48 hours. RESULTS There were no significant differences in calcium, oxalate, magnesium, phosphate, sodium, urate or pH (without acidification) between samples with different preservation methods (P >.05). Urinary citrate, however, was significantly lower in the urine collected with HCl than when other preservatives were used, both at room temperature and at 4 °C. Urine pH was significantly higher after 48 hours than after 24 hours, whether the samples were stored at room temperature or at 4 °C. CONCLUSION Antibacterial preservatives (eg, thymol or toluene) can be recommended as preservatives for 24-hour urine collections. Ideally, the samples should be stored at 4 °C. When HCl is used as a preservative, it seems essential to neutralize the samples before analysis. This is particularly obvious with the chromatographic method used for analysis of citrate that was used in this study.

Difference in 24-Hour Urine Composition between Diabetic and Non-Diabetic Adults without Nephrolithiasis.

Background Diabetic patients are more likely to develop kidney stones than the general population. The underlying mechanisms for this disparity remain to be elucidated. Little is known about the relationship between urine composition and diabetes mellitus in non-stone-forming individuals. We sought to examine the differences in the 24-hour (24-h) urine composition between diabetic and non-diabetic adults who were not stone formers. Methods A convenience sample of 538 individuals without a history of nephrolithiasis, gout, hyperparathyroidism, or gastroenteric diseases participated in this study. The 24-h urine profiles of 115 diabetic adults were compared with those of 423 non-diabetic adults. Diabetes was defined by self-reported physician diagnosis or medication use. All participants were non-stone formers confirmed by urinary tract ultrasonography. Participants provided a fasting blood sample and a single 24-h urine collection for stone risk analysis. Student’s t-test was used to compare mean urinary values. Linear regression models were adjusted for age, gender, body mass index, hypertension, fasting serum glucose, serum total cholesterol, estimated creatinine clearance rate and urinary factors. Results Univariable analysis showed that the diabetic participants had significantly higher 24-h urine volumes and lower urine calcium and magnesium excretions than non-diabetic participants (all P < 0.05). After multivariate adjustment, no significant differences in 24-h urine composition were observed between diabetic and non-diabetic participants except for a slightly increased 24-h urine volume in diabetic participants (all P > 0.05). The main limitation of this study is that the convenience samples and self-reported data may have been sources of bias. Conclusion Our data showed that there were no differences in 24-h urine composition between diabetic and non-diabetic adults who are not stone formers. The reason for it might be the improved glycemic control in diabetic individuals in our study. Therefore, a tighter glycemic control might reduce stone formation in diabetic adults.

Serum estradiol and testosterone levels in kidney stones disease with and without calcium oxalate components in naturally postmenopausal women.

Objective Epidemiological data reveal that the overall risk for kidney stones disease is lower for women compared to age-matched men. However, the beneficial effect for the female sex is lost upon menopause, a time corresponding to the onset of fall in estrogen levels. The aim of this study was to describe the serum estradiol (E2) and testosterone (T) characteristics of naturally postmenopausal women with kidney stones. Methods 113 naturally postmenopausal women with newly diagnosed kidney stones (aged 57.4±4.98 years) and 84 age frequency matched stone-free controls (56.9±4.56 years) were validly recruited in the case-control study. The odds ratios (ORs) for the associations between sex hormones and kidney stones were estimated with logistic regression models, adjusting for demographic data and medical history. Patients were also stratified analyzed according to stone components (calcium oxalate stones [COS]; non-calcium oxalate stones [NCOS]). Results Serum E2 (21.1 vs. 31.1 pg/ml) was significantly lower in kidney stones patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by COS patients (p<0.001). According to tertiles of the E2 levels, a significant higher frequency of COS was seen in the lowest E2 group (p <0.001). Multiple logistic regression analysis identified E2 level as a strong factor that was independently associated with the risk for COS (per 1 SD increase, OR=0.951, 95% confidence interval [CI] = 0.919-0.985; highest: lowest tertile, OR=0.214, 95%CI = 0.069-0.665). However, serum T levels did not significantly differ among the groups. Conclusions Naturally postmenopausal women with higher remaining estradiol levels appear less likely to suffer from kidney calcium oxalate stones. However, no correlation was found between serum T level and kidney stones. These findings support the hypothesis that higher postmenopausal endogenous estrogens may protect against kidney stones with ageing.

Influence of weight status on 24-hour urine composition in adults without urolithiasis: A nationwide study based on a Chinese Han population

Objectives This study sought to explore the influence of different body weight statuses on 24-hour urine compositions in adults without urolithiasis based on a nationwide study of a Chinese Han population. Material and methods Twenty-four-hour urine samples from 584 Chinese Han adults without urolithiasis in six cities were analyzed. The participants were divided into four body weight status types according to their body mass indices (BMIs) according to WHO guidelines. The baseline characteristics and 24-hour urine compositions of the standard weight group were compared with those of the underweight, overweight and obese groups. The influences of different body weight statuses on the 24-hour urine compositions were explored using univariate and multivariate logistic regressions. Results The numbers of participants in the underweight, standard weight, overweight and obese status groups were 24, 376, 149 and 35, respectively. The overweight and obese groups suffered significantly higher risks of hypertension and diabetes mellitus than the standard weight group. In the univariate analyses, compared with the standard weight group, the overweight group had significantly higher levels of urine citrate (mean difference [MD] = 0.51 mmol, 95% confidence interval [CI]: 0.15–0.87, P = 0.001), potassium (MD = 6.63 mmol, 95% CI: 1.13–12.14, P = 0.01) and magnesium (MD = 0.38 mmol, 95% CI: 0.08–0.69, P = 0.014). Significant increases in urine citrate (MD = 0.85 mmol, 95% CI: 0.01–1.68, P = 0.046), magnesium (MD = 0.69 mmol, 95% CI: 0.13–1.25, P = 0.016) and phosphate (MD = 2.28 mmol, 95% CI: 0.03–4.54, P = 0.047) were found in the obese group. No significant differences were detected between the standard weight and underweight groups. In the multivariate logistic regression analyses, we only observed significantly higher levels of urine potassium (odds ratio [OR] = 1.02, 95% CI: 1.00–1.04, P = 0.03) in the overweight group and phosphate (OR = 1.32, 95% CI: 1.05–1.66, P = 0.018) in the obese group when compared with the standard weight group. Conclusions Nonstone-forming adults with overweight or obese statuses were at higher risks of hypertension and diabetes mellitus. Obese nonstone-formers might have a greater risk of urinary stone formation due to increased urinary phosphate excretion. Additionally, underweight status had no influence on 24-hour urine composition.

Prevalence of metabolic syndrome in China: An up-dated cross-sectional study

Metabolic syndrome (MS) is an increasing public health concern because of rapid lifestyle changes. Although there have been previous studies on the prevalence of MS in China, the prevalence may have changed with lifestyle changes over the last decade. To update this prevalence, we performed a cross-sectional survey among adults over 18 years old across China from May 2013 to July 2014. Participants underwent questionnaires and provided blood and urine samples for analysis. MS was defined according to the criteria of the China Diabetes Society. A total of 12570 individuals (45.2% men) with an average age of 48.8±15.3 (18–96) years were selected and invited to participate in the study. In total, 9310 (40.7% men) individuals completed the investigation, with a response rate of 74.1%. The prevalence of MS in China was 14.39% [95% confidence interval (CI): -3.75–32.53%], and the age-adjusted prevalence was 9.82% (95% CI: 9.03–10.61%; 7.78% in men and 6.76% in women; 7.39% in rural residents and 6.98% in urban residents). The highest prevalence occurred among adults aged 50–59 years (1.95%, 95% CI: 1.40–2.50%), and the lowest prevalence occurred among adults aged 40–49 years (0.74%, 95% CI: 0.38–1.10%); the prevalence was the highest in the south region and lowest in the east region (4.46% and 1.23%, respectively). The results of logistic regression analyses showed that age, urolithiasis, hyperuricemia, coronary artery disease, thiazide drugs intake, family history of diabetes and hypertension were all significantly associated with an increased risk of metabolic syndrome (OR>1). In addition, education, vitamin D intake and family history of urolithiasis are all protective factors (OR<1). Our results indicate that there was a high prevalence of MS in Chinese adults. Compared to the previous study 10 years ago, some preventive strategies have worked; however, further work on the prevention and treatment of MS remains necessary.

miR-195 inhibits cell proliferation and angiogenesis in human prostate cancer by downregulating PRR11 expression

hsa-miR-195-5p (miR-195) has been proven to be a critical regulator in the progression of prostate cancer (PCa). To identify additional targets and molecular functions of miR-195, we overexpressed miR-195 by transient oligonucleotide transfection in DU145 and LNCaP cells and examined the effects. RNA-based microarray and dual-luciferase assays were carried out to identify novel targets of miR-195, while in vitro functional assays, a subcutaneous xenograft model, tissue microarray (TMA) analysis and a cohort of publicly available data (Taylor cohort) were used to investigate the biological function and clinical value of miR-195 targeting. The results shown that miR-195 overexpression could markedly suppress cellular proliferation and tube formation compared with miR-negative control. The RNA-based microarray identified a total of 153 differentially regulated genes with fold changes of ≤|1.5|, including 138 (90.2%) downregulated and 15 (9.8%) upregulated genes. Among the downregulated genes, we found that proline-rich protein 11 (PRR11) combined with miR-195 expression (miR-195/PRR11) could be used as an independent predictor of the risk of biochemical recurrence in the Taylor cohort. Additionally, the dual-luciferase assay identified PRR11 as a novel target of miR-195, and the in vitro assays indicated that PRR11 abrogated the suppressive effects of miR-195 on cell proliferation, tube formation and cell cycling. Furthermore, the subcutaneous tumor xenograft model indicated that knockdown of PRR11 inhibited xenograft growth and angiogenesis, while the results of the TMA and Taylor cohort analyses collectively demonstrated that PRR11 expression was upregulated in aggressive tumors and is associated with poor clinical outcome. Taken together, these findings further illustrate the suppressive role of miR-195 in PCa, and indicate a novel role of PRR11 in PCa. Importantly, the newly identified miR-195/PRR11 axis may aid with identifying potential therapeutic targets in PCa.

Composition of urinary tract stones formed by children in two populations in the Uyghur region of China

Background: To retrospectively compare the composition of urinary tract stones formed by Uyghur children from the southern (Kashgar) and northern (Urumchi) parts of the Xinjiang region. Methods: The chemical composition of urinary tract calculi formed by 855 Uyghur children from the two regions in Xinjiang (366 Kashgar and 489 Urumchi) was compared retrospectively. Stone composition was determined by infrared spectroscopy. Factors that might have been of relevance for the findings such as age, gender, stone location and geographic region were also considered. Results: Kashgar children were younger than Urumchi children (2.8 ± 2.7 vs. 4.3 ± 3.7 years, p < 0.001). Although ammonium urate was the dominant stone component in the whole population, calcium oxalate was most common in children from Urumchi. The mean occurrence of ammonium urate, calcium oxalate and uric acid differed significantly between stones formed by Kashgar and Urumchi children (52.5% vs. 29.2%, 18.9% vs. 29.4%, 12.3% vs. 20.9%; respectively, p < 0.001). Renal stones were less frequently recorded in Kashgar children than in Urumchi children (65.8% vs. 91.6%, p < 0.001). Interestingly, bladder stones were more common in children from Kashgar (28.4% vs. 3.7%; p < 0.001). Conclusion: Uyghur children from the southern part of Xinjiang apparently had a more serious form of stone disease than children from the northern part and the occurrence of stones dominated by ammonium urate stones was extremely high in children from the southern part of the region.