Curcumin alleviated oxidation stress injury by mediating osteopontin in nephrolithiasis rats.

PURPOSE: To explore the role and mechanism of curcumin (Cur) in reducing oxidative stress damage in rats with nephrolithiasis induced by ethylene glycol (EG). METHODS: Thirty male rats were divided into normal control, model, positive (10% potassium citrate), Cur-10 (10 mg/kg curcumin) and Cur-20 (20 mg/kg curcumin) groups. RESULTS: The results of kidney tissue section stained by hematoxylin-eosin and von Kossa showed that curcumin treatment can inhibit the formation of kidney stones. The biochemical test results showed that the urea (Ur), creatinine (Cr), uric acid (UA), inorganic phosphorus and Ca2+ concentrations in urine decreased after being treated with curcumin. There were significant differences between different doses of curcumin (P < 0.05). Compared with the Cur-10 group, Cur-20 had a more significant inhibitory effect on malondialdehyde (MDA) (P < 0.05). In addition, reverse transcription polymerase chain reaction (PCR) detection and immunohistochemical results indicated that the osteopontin (OPN) in the kidney was significantly reduced after curcumin treatment. CONCLUSIONS: Curcumin could reduce the oxidative stress damage caused by EG-induced kidney stones.

Curcumin alleviated oxidation stress injury by mediating osteopontin in nephrolithiasis rats

Purpose: To explore the role and mechanism of curcumin (Cur) in reducing oxidative stress damage in rats with nephrolithiasis induced by ethylene glycol (EG). Methods: Thirty male rats were divided into normal control, model, positive (10% potassium citrate), Cur-10 (10 mg/kg curcumin) and Cur-20 (20 mg/kg curcumin) groups. Results: The results of kidney tissue section stained by hematoxylin-eosin and von Kossa showed that curcumin treatment can inhibit the formation of kidney stones. The biochemical test results showed that the urea (Ur), creatinine (Cr), uric acid (UA), inorganic phosphorus and Ca2+ concentrations in urine decreased after being treated with curcumin. There were significant differences between different doses of curcumin (P < 0.05). Compared with the Cur-10 group, Cur-20 had a more significant inhibitory effect on malondialdehyde (MDA) (P < 0.05). In addition, reverse transcription polymerase chain reaction (PCR) detection and immunohistochemical results indicated that the osteopontin (OPN) in the kidney was significantly reduced after curcumin treatment. Conclusion: Curcumin could reduce the oxidative stress damage caused by EG-induced kidney stones.

Fractionalization on the Surface: Is Type-II Terminated 1T-TaS_{2} Surface an Anomalously Realized Spin Liquid?

The type-II terminated 1T-TaS_{2} surface of a three-dimensional 1T-TaS_{2} bulk material realizes the effective spin-1/2 degree of freedom on each David star cluster with T^{2}=-1 such that the time-reversal symmetry is realized anomalously, despite the fact that bulk three-dimensional 1T-TaS_{2} material has an even number of electrons per unit cell with T^{2}=+1. This surface is effectively viewed as a spin-1/2 triangular lattice magnet, except with a fully gapped topological bulk. We further propose this surface termination realizes a spinon Fermi surface spin liquid with the surface fractionalization but with a nonexotic three-dimensional bulk. We analyze possible experimental consequences, especially the surface spectroscopic measurements, of the type-II terminated surface spin liquid.

Flexible Ureterorenoscopy Management of Calyceal Diverticular Calculi.

OBJECTIVE: To introduce flexible ureterorenoscopy with holmium laser lithotripsy in the management of symptomatic caliceal diverticular calculi. MATERIALS AND METHODS: The records of 26 patients who underwent flexible ureterorenoscopy and lithotripsy with holmium laser to manage symptomatic caliceal diverticular calculi from January 2012 to June 2016 were retrospectively reviewed. RESULT: Flexible ureterorenoscopy lithotripsy was successfully placed in all 26 patients. Twenty-two cases accepted lithotripsy at the same time, and the success rate was 84.6%. The stone-free rate was 76.9%.The mean operative time was 48 ± 16 minutes. The mean hospital stay was 4.8 ± 1.6 days. There was no evidence of stone regrowth or recurrence at a mean follow-up of 11.5 months. CONCLUSION: Flexible ureterorenoscopy with holmium laser lithotripsy is safe and effective, and it can be offered as a first line therapy for symptomatic caliceal diverticular calculi.

Association of rs3787016 in Long Non-coding RNAs POLR2E and rs2910164 in MiRNA-146a with Prostate Cancer: A Systematic Review and Meta-analysis.

BACKGROUND: The aim of this study was to conduct a meta-analysis to estimate the association between the two SNPs and PCa risk. METHODS: Medline, Embase, Scopus, PubMed, Web of Science, Wan Fang Database and Chinese Zhi Wang Database were searched for the association of the two SNPs with susceptibility to PCa. The effect size was pooled by odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS: Nine case-control studies, 5 on rs3787016 and 4 on rs2910164, were included. As regards rs3787016, an increased risk of PCa was identified in all genotype models (T versus C: OR = 1.18, 95% CI 1.11-1.25; CT versus CC: OR = 1.17, 95% CI 1.08-1.26; TT versus CC: OR = 1.41, 95% CI 1.22-1.63; TT + CT versus CC: OR = 1.20, 95% CI 1.12-1.30; TT versus CT + CC: OR = 1.32, 95% CI 1.15-1.52). However, no significant association was found between rs2910164 and PCa risk in any genetic models, in fact a trend of reduced risk could be seen (C versus G: OR = 0.91, 95% CI 0.79-1.05; GC versus GG: OR = 0.93, 95% CI 0.74-1.18; CC versus GG: OR = 0.70, 95% CI 0.47-1.02; CC + GC versus GG: OR = 0.90, 95% CI 0.73-1.12; CC versus GC + GG: OR = 0.78, 95% CI 0.56-1.08). Besides, in analysis of subgroups by source of controls, the decreased results were observed in studies using population-based controls. CONCLUSION: lncRNA POLR2E polymorphism rs3787016 is associated with a significantly increased risk of PCa, while a trend of reduced risk appears with mir-146a polymorphism rs2910164.

Long noncoding RNA SNHG7 accelerates prostate cancer proliferation and cycle progression through cyclin D1 by sponging miR-503.

Increasing evidence has indicated the important roles of long non-coding RNAs (lncRNAs) in tumorigenesis and cellular progression, including prostate cancer. In this study, we aim to investigate the expression level of SNHG7 and its biological functions on prostate cancer cells. Results indicated that SNHG7 expression was significantly up-regulated in prostate cancer tissue and cell lines. Besides, the overexpression of SNHG7 was closely correlated with the poor prognosis. In vitro and in vivo, experiments demonstrated that SNHG7 knockdown markedly inhibited prostate cancer proliferation and cycle-related protein (CDK4, CDK6, Cyclin D1), induced cell cycle arrest at G0/G1 phase and suppressed tumor growth. Moreover, miR-503 was predicted by bioinformatics tools and validated using luciferase reporter assay to both directly inhibited SNHG7 and Cyclin D1 expression by targeting their RNA 3'-UTR. In conclusion, results present that SNHG7 regulates the cycle progression and acts as an oncogenic gene in the prostate cancer tumorigenesis via miR-503/Cyclin D1 pathway, revealing the vital role of lncRNA/miRNA/mRNA axis in prostate cancer carcinogenesis.

Meta-analysis of CDKN2A methylation to find its role in prostate cancer development and progression, and also to find the effect of CDKN2A expression on disease-free survival (PRISMA).

BACKGROUND: Reduction of cyclin-dependent kinase inhibitor 2A (CDKN2A) (p16 and p14) expression through DNA methylation has been reported in prostate cancer (PCa). This meta-analysis was conducted to assess the difference of p16 and p14 methylation between PCa and different histological types of nonmalignant controls and the correlation of p16 or p14 methylation with clinicopathological features of PCa. METHODS: According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement criteria, articles were searched in PubMed, Embase, EBSCO, Wanfang, and CNKI databases. The strength of correlation was calculated by the pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs). Trial sequential analysis (TSA) was used to estimate the required population information for significant results. RESULTS: A total of 20 studies published from 1997 to 2017 were identified in this meta-analysis, including 1140 PCa patients and 530 cases without cancer. Only p16 methylation in PCa was significantly higher than in benign prostatic lesions (OR = 4.72, P = .011), but had a similar level in PCa and adjacent tissues or high-grade prostatic intraepithelial neoplasias (HGPIN). TSA revealed that this analysis on p16 methylation is a false positive result in cancer versus benign prostatic lesions (the estimated required information size of 5116 participants). p16 methylation was not correlated with PCa in the urine and blood. Besides, p16 methylation was not linked to clinical stage, prostate-specific antigen (PSA) level, and Gleason score (GS) of patients with PCa. p14 methylation was not correlated with PCa in tissue and urine samples. No correlation was observed between p14 methylation and clinical stage or GS. CDKN2A mutation and copy number alteration were not associated with prognosis of PCa in overall survival and disease-free survival. CDKN2A expression was not correlated with the prognosis of PCa in overall survival (492 cases) (P > .1), while CDKN2A expression was significantly associated with a poor disease-free survival (P < .01). CONCLUSION: CDKN2A methylation may not be significantly associated with the development, progression of PCa. Although CDKN2A expression had an unfavorable prognosis in disease-free survival. More studies are needed to confirm our results.

Protective effect of curcumin against cyclosporine A­induced rat nephrotoxicity.

This study explored the potential value of curcumin, a natural product, in the protection of CsA­induced nephrotoxicity. The aim of the present study was to investigate the effects of curcumin on Cyclosporine A (CsA)­induced renal oxidative stress and determine the potential underlying molecular mechanisms of the renal protective effects of Cur. HK­2 human renal cells were co­treated with CsA and various doses of Cur. Cell survival rate was determined by an MTT assay, total cellular protein was collected and oxidative stress in cell homogenates was evaluated by determining the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH­Px) and catalase (CAT), the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), and total antioxidant capacity. Furthermore, Bcl­2 and Bcl­2­associated X (Bax) protein expression was measured by western blot analysis. In addition, a CsA­induced nephrotoxicity (CAN) rat model was also established. Renal function was analyzed by measuring creatinine (Crea) and blood urea nitrogen (BUN) in the serum of rats, and histopathological examination was performed on renal tissues using hematoxylin and eosin staining, periodic acid­Schiff staining and nuclear factor­κB (NF­κB) immunostaining. The results demonstrated that treatment of HK­2 cells with CsA significantly increased ROS and MDA levels, and decreased the activities of SOD, GSH­Px and CAT, compared with the control group. However, these effects of CsA were dose­dependently improved by treatment with Cur. In addition, Cur treatment increased Bcl­2 and decreased Bax protein in HK­2 cells, compared with cells treated with CsA alone. In the CAN rat model CsA (30 mg/kg) treatment significantly elevated serum Crea levels and BUN, but lowered endogenous Crea clearance rate, compared with the control group. Co­administration of Cur with CsA significantly reversed the effects of CsA on serum Crea levels, BUN and Crea clearance rate (Ccr). Additionally, Cur alleviated CsA­induced renal cell injury, as less vacuolar degeneration of glomerular cells was observed compared with the CsA alone group. In conclusion, Cur may increase renal antioxidant capacity and reduce the Bax/Bcl­2 ratio, subsequently improving CsA­induced renal failure and renal tubular deformation and cell vacuolization.

The Transcription Factor Creb is Involved in Sorafenib-Inhibited Renal Cancer Cell Proliferation, Migration and Invasion.

Our previous reports showed that the cyclic-AMP-response element-binding protein (CREB) served as a proto-oncogene in the process of tumorigenesis and mediated the growth and metastatic activity of renal cancer cells. Our study, therefore, explored the role of CREB in sorafenib- -inhibited cell proliferation, migration and invasion. Renal cancer cells were cultured in medium containing sorafenib for 12, 24, 48 and 72 h. The MTT assay was used to study the cytotoxic effects of sorafenib. Cell invasion and migration were assayed in wound healing and transwell experiments, respectively. Protein expression levels were evaluated by western blotting. The results show that sorafenib treatment decreased cell viability in a dose- and time-dependent manner. Sorafenib inhibited cell migration and invasion and decreased the expression of MMP-2 and MMP-9. Moreover, addition of the recombinant plasmid pCI-neo/ CREB (PN) reversed the sorafenib-induced inhibition of cell proliferation, migration and invasion. These results show that CREB is associated with the sorafenib-induced inhibition of proliferation, migration and invasion.

Ginkgetin induces apoptosis in 786-O cell line via suppression of JAK2-STAT3 pathway.

OBJECTIVES: Renal cell carcinoma (RCC) is insensitive to conventional chemotherapy. Ginkgetin effectively treats several carcinoma cells. However, little is known about effects of Ginkgetin on RCC. In the present study, using 786-O cells, we evaluate whether Ginkgetin exerts anticancer effects against RCC. MATERIALS AND METHODS: 786-O cells suspended in the medium containing Ginkgetin were cultured for 24 hr to 72 hr, and then MTT assay was used to study cytotoxic effect of Ginkgetin. Apoptosis in 786-O was measured by an FITC Annexin apoptosis detection kit. Protein expression was detected by Western blotting. 786-O cells with active Janus kinase 2 (JAK2)-Signal transducer and activator of transcription 3 (STAT3) were prepared by stimulant of interleukin-6 (IL-6), whereas 786-O cells with deactivated STAT3 were produced by small interfering RNA (siRNA) STAT3. RESULTS: Ginkgetin suppressed the growth of 786-O in dose and time-dependent manners with IC50 values of 7.23 µM. Ginkgetin induced apoptosis of 786-O cells and increased the levels of caspase-8, caspase-9, and caspase-3. Additionally, Ginkgetin treated 786-O cells showed decreased levels of JAK2 and phosphorylated-STAT3 whether or not IL-6 was pretreated. Interestingly, pretreatment of siRNA STAT3 exerted inhibitory effects on the growth of 786-O cells, and the observation could be further reinforced after the Ginkgetin treatment. CONCLUSION: Our results indicate Ginkgetin possesses obvious inhibitory effects on the proliferation of 786-O, and this effect is probably due to its inhibition of JAK2/STAT3 pathway. Our findings imply Ginkgetin is a potential therapeutic medicine for RCC.

Cantharidin induces G2/M arrest and triggers apoptosis in renal cell carcinoma.

The present study aimed to investigate the effects of cantharidin on cell cycle distribution, the induction of apoptosis, and Notch1 and Jagged1 expression in ACHN and Caki­1 renal cancer cells. Cell viability assay, flow cytometry, cell cycle and western blot analyses were performed for ACHN and Caki­1 cells. Immunohistochemistry was used to analyze the expression of Notch1 and Jagged1 in RCC tissues The results demonstrated that treatment with cantharidin exerted a dose­ and time­dependent effect on cell viability, apoptosis induction and G2/M phase cell cycle arrest. Exposure of ACHN and Caki­1 cells to 20 µM cantharidin reduced cell viability to 26 and 32% respectively, after 48 h. In addition, treatment with cantharidin enhanced the number of ACHN and Caki­1 cells in G2/M phase to 54.62 and 51.88% respectively, as compared with 17.16 and 16.53% in the control groups. In the ACHN and Caki­1 cells, treatment with cantharidin induced a marked increase in the proportion of apoptotic cells after 48 h. Furthermore, cantharidin enhanced the percentage ACHN and Caki­1 apoptotic cells to 57.23 and 62.34% respectively, as compared with 2.27 and 3.06% in the control groups. Detection of Notch1 and Jagged1 expression demonstrated that levels were significantly increased in carcinoma tissues. Conversely, cantharidin exhibited an inhibitory effect on Notch1 and Jagged1 expression after 48 h. Therefore, treatment with cantharidin may exert a promising effect on the inhibition of renal cancer, and may be of therapeutic importance for the treatment of renal cancer.

Clinical significance of CDH13 promoter methylation as a biomarker for bladder cancer: a meta-analysis.

BACKGROUND: Methylation of the tumor suppressor gene H-cadherin (CDH13) has been reported in many cancers. However, the clinical effect of the CDH13 methylation status of patients with bladder cancer remains to be clarified. METHODS: A systematic literature search was performed to identify eligible studies in the PubMed, Embase, EBSCO, CKNI and Wanfang databases. The pooled odds ratio (OR) and the corresponding 95 % confidence interval (95 % CI) was calculated and summarized. RESULTS: Nine eligible studies were included in the present meta-analysis consisting of a total of 1017 bladder cancer patients and 265 non-tumor controls. A significant association was found between CDH13 methylation levels and bladder cancer (OR = 21.71, P < 0.001). The results of subgroup analyses based on sample type suggested that CDH13 methylation was significantly associated with bladder cancer risk in both the tissue and the urine (OR = 53.94, P < 0.001; OR = 7.71, P < 0.001; respectively). A subgroup analysis based on ethnic population showed that the OR value of methylated CDH13 was higher in Asians than in Caucasians (OR = 35.18, P < 0.001; OR = 8.86, P < 0.001; respectively). The relationships between CDH13 methylation and clinicopathological features were also analyzed. A significant association was not observed between CDH13 methylation status and gender (P = 0.053). Our results revealed that CDH13 methylation was significantly associated with high-grade bladder cancer, multiple bladder cancer and muscle invasive bladder cancer (OR = 2.22, P < 0.001; OR = 1.45, P = 0.032; OR = 3.42, P < 0.001; respectively). CONCLUSION: Our study indicates that CDH13 methylation may play an important role in the carcinogenesis, development and progression of bladder cancer. In addition, CDH13 methylation has the potential to be a useful biomarker for bladder cancer screening in urine samples and to be a prognostic biomarker in the clinic.

Basiliximab induction in kidney transplantation with donation after cardiac death donors.

Basiliximab is a monoclonal antibody that binds to the α-chain of the interleukin (IL)-2 receptor. It is used as induction therapy in kidney transplantation. The objective of the present study was to evaluate induction therapy with single-dose basiliximab (Simulect®) in kidney transplantation with donation after cardiac death (DCD) donors. A total of 33 DCD kidney transplants were performed between December 2010 and July 2013 in patients who received single-dose basiliximab (20 mg) as induction therapy. The maintenance immunosuppression included calcineurin inhibitor (cyclosporine A or tacrolimus), mycophenolate mofetil and corticosteroids. The follow-up time was 1 year. The mean ages of the DCD donors and recipients were 29.3 and 41.1 years, respectively. Within the 1-year follow-up, the overall incidence of acute rejection was 9.1%. There were 10 cases of delayed graft function among the recipients. Mean serum creatinine values at 1 week and at 1, 3, 6, 9 and 12 months post-transplantation were 257.6, 238.2, 194.5, 159.3, 137.9 and 110.8 µmol/l, respectively, with a favorable trend to allograft function recovery over time. The 1-year patient and graft survival rates were 96.9 and 90.9%, respectively, with an infection rate of 24.2%. Increased alanine aminotransferase/aspartate transaminase levels in only 2 patients were considered to be associated with basiliximab. This experience with single-dose basiliximab for induction therapy in DCD kidney transplantation showed that favorable clinical outcomes were achieved in terms of graft survival and function within 1 year.

Arterial Injury during Percutaneous Nephrostomy: Angiography Findings from an Isolated Porcine Kidney Model.

PURPOSE: To investigate the extent of renal arterial injury incurred by different size of nephrostomy tracts from 10 French (F) to 32F in vitro porcine kidney. MATERIALS AND METHODS: To simulate the technique of percutaneous nephrostomy we set up 12 groups of different size nephrostomy tracts from 10F to 32F, including 40 nephrostomy tracts in each group. Digital subtraction angiography (DSA) was used to inspect and analysis of arterial injury. RESULTS: When the size of nephrostomy tracts is increased from 10F to 32F, the degree of arterial injury is also aggravated. With 14F compared to 24F, the number of nephrostomy tracts with serious arterial injury was 12 (12/40) and 23 (23/40), respectively (P < .05). With 18F compared to 30F, the number of nephrostomy tracts with serious arterial injury was 16 (16/40) and 30 (28/40), respectively (P < .01). CONCLUSION: When the size of nephrostomy tract is increased, the degree of renal arterial injury is also heightened. When 18F tracts was compared to 30F tracts and 14F tracts compared to 24F tracts, obvious reduction of arterial injury is observed.

Essential role of the cGMP/PKG signaling pathway in regulating the proliferation and survival of human renal carcinoma cells.

Phosphodiesterase type 5 (PDE5) plays a key role in regulating the intracellular cyclic GMP (cGMP) concentration, which influences anti-proliferative and pro-apoptotic mechanisms in multiple carcinomas. PDE5 inhibitors, such as exisulind and its analogs have anticancer activities. In this study, we found that suppressing PDE5 gene expression by PDE5 siRNA inhibited cell proliferation and induced apoptosis in OS-RC-2 human renal cell carcinoma cells. These effects were enhanced by 8-Br-cGMP, a cell membrane permeable cGMP derivative, and were inhibited by KT5823, a protein kinase G (PKG) inhibitor, indicating that PKG was activated by intracellular cyclic GMP. In addition, there was a reduction in both the mRNA and protein expression of cyclin D1, while p21 protein expression was increased; the reduction in cyclin D1 expression was blocked by the proteasome inhibitor, MG132, or c-Jun N-terminal kinase (JNK) inhibitor; both ß-catenin and JNK were phosphorylated by activated PKG. Furthermore, p21 protein expression was decreased in Sp1 siRNA transfected-cells treated with 8-Br-cGMP, indicating that p21 may be partly controlled by the PKG activation through Sp1. Furthermore, we found that PKG Iß was responsible for the anticancer activities. Our findings indicate that the downregulation of PKG-activated genes, such as cyclin D1 partly accounts for the pro-apoptotic effects in PDE5 siRNA-transfected OS-RC-2 cells.

Health-related quality of life in dialysis patients with constipation: a cross-sectional study.

OBJECTIVES: To evaluate differences in the health-related quality of life (HRQoL) between patients with constipation receiving hemodialysis (HD) and those receiving peritoneal dialysis (PD). METHODS: In this cross-sectional study, 605 dialysis patients (478 HD cases and 127 PD cases; all patients were older than 18 years) from our hospital were included. A questionnaire was used to evaluate their constipation statuses. The effect of constipation on HRQoL was assessed, using the Chinese version of the 12-item short-form (SF-12) general health survey. Karnofsky score, sociodemographic, and clinical data were also collected. We performed multiple logistic regression analysis to define independent risk factors for constipation and impaired HRQoL. RESULTS: A total of 605 participants (326 men [53.9%] and 279 women [46.1%]) were surveyed. The incidence of constipation was 71.7% in HD patients and 14.2% in PD patients. Dialysis patients with constipation had significantly lower mean SF-12 Physical Component Summary scale and Mental Component Summary scale scores than the nonconstipation group (P < 0.05), whereas HD patients had better SF-12 Physical Component Summary and Mental Component Summary scores than PD patients (P < 0.05). When we performed multivariate logistic regression analysis, dialysis modality, diabetes, and the number of constipation-related medications were three independent risk factors associated with constipation. As for impaired HRQoL in the constipated dialysis population, dialysis modality was found to be another independent risk factor in addition to age and diabetes. CONCLUSION: PD patients with constipation had worse HRQoL than HD control participants. We should pay more attention to the patients with constipation receiving PD, as peritonitis caused by constipation was associated with a higher mortality.

Gastric metaplasia and Helicobacter pylori infection in hemodialysis patients.

BACKGROUND: Upper gastrointestinal (UGI) symptoms are common in hemodialysis (HD) patients, while gastric metaplasia (GM) and Helicobacter pylori infections are key causes for UGI symptoms. This study is targeted to compare GM and H. pylori infections in patients with different durations of HD. METHODS: A total of 406 subjects from Ningbo Urology and Nephrology Hospital were included. The mean age of subjects was 44.7 ± 13.5 years; 62.9% were male; and subjects were divided into four groups according to different HD durations. Upper endoscopy and lesion were performed in these patients and methylene blue staining was used in detecting H. pylori and GM. RESULTS: Erosive gastritis was the most common symptom in uremic subjects. GM was found in 139 patients. The longer the dialysis duration, the higher the incidence rate of GM (p < 0.05). H. pylori infection accounted for 24.1% in HD patients. The occurrence of H. pylori infection decreased as dialysis periods progressed within the first 4-year follow-up after the start of HD. CONCLUSIONS: Almost all patients with HD experienced gastrointestinal discomfort in the current patient cohort. The most common mucosal lesion observed in our study pool was chronic erosive gastritis. The overall incidence of GM was normal at 35.0%, since quite a part of patients are the elderly group in this study. We need not worry about this too much, unless the HD patients have registered for renal transplantation or are suffering from severe gastrointestinal discomfort.