Enzalutamide versus Abiraterone Plus Prednisolone for Nonmetastatic Castration-Resistant Prostate Cancer: A Sub-Analysis from the ENABLE Study for PCa

Enzalutamide (ENZ) and abiraterone plus prednisolone (ABI) can improve the survival of patients with castration-resistant prostate cancer (CRPC). However, the agent that is more effective against nonmetastatic CRPC remains unclear. To evaluate the agent that can be used as the first-line treatment for CRPC, an investigator-initiated, multicenter, randomized controlled trial (ENABLE Study for PCa) including both metastatic and nonmetastatic CRPC was conducted in Japan. The prostate-specific antigen (PSA) response rate, overall survival, some essential survival endpoints, and safety of patients with nonmetastatic CRPC were also analyzed. In this subanalysis, 15 and 26 patients in the ENZ and ABI arms, respectively, presented with nonmetastatic CRPC. There was no significant difference in terms of the PSA response rate between the ENZ and ABI arms (80% and 64%, respectively; p = 0.3048). The overall survival did not significantly differ between the two arms (HR: 0.68; 95% CI: 0.22-2.14, p = 0.5260). No significant differences were observed in terms of radiographic progression-free survival and cancer-specific survival between the ENZ and ABI arms (HR: 0.81; 95% CI: 0.35-1.84; p = 0.6056 and HR: 0.72; 95% CI: 0.19-2.73; p = 0.6443, respectively). Only four and six patients in the ENZ and ABI arms, respectively, had ≥grade 3 adverse events. ABI and ENZ had similar efficacy and safety profiles in patients with nonmetastatic CRPC.

G protein-coupled receptor 55 activated by palmitoylethanolamide is associated with the development of nocturia associated with circadian rhythm disorders

AIMS

Bladder function is regulated by clock genes and dysregulation of circadian bladder function can cause nocturia. The blood concentration of palmitoylethanolamide (PEA), a fatty acid metabolite, changes with circadian rhythm. Clock gene abnormalities demonstrate the highest PEA levels during the sleep phase. PEA is a GPR55 agonist that influences urination; therefore, increased PEA during the sleep phase may cause nocturia. Herein, we investigated the function of GPR55 to evaluate the relationship between GPR55 and nocturia that evoked higher PEA during the sleep phase in patients with circadian rhythm disorders.

MAIN METHODS

Male C57BL/6 mice were used. GPR55 localization was evaluated by immunofluorescence staining, qRT-PCR, and western blotting. Variations in PEA-induced intracellular Ca2+ concentrations were measured in primary cultured mouse urothelial cells (UCs) using Ca2+ imaging. PEA-induced NGF and PGI2 release in UCs was measured by ELISA. The micturition reflex pathway after PEA administration was evaluated using immunofluorescence staining.

KEY FINDINGS

GPR55 was predominant in the UC layer. PEA induced release of Ca2+ from the endoplasmic reticulum into the UC cytoplasm. ELISA and immunofluorescence staining revealed that NGF and PGI2 were released from bladder UCs, stimulated the pontine micturition center in mice, and induced nocturia.

SIGNIFICANCE

The loss of regular circadian metabolizing rhythm in fatty acids causes higher blood PEA levels during the sleep phase. Binding of PEA to GPR55 in UC may activate the downstream processes of the micturition reflex, leading to nocturia. These findings suggest a new mechanism for nocturia and its potential as a therapeutic target.

Predictive factors for the effectiveness of novel androgen receptor axis-targeted agents in patients with metastatic prostate cancer

OBJECTIVE

Novel androgen receptor axis-targeted agents (ARATAs) have been developed for mCRPC and improved overall survival (OS). Here, we aimed to find predictors who will receive the greatest benefits from ARATAs.

METHODS

We previously performed a multicenter study to identify prognostic factors for metastatic hormone-sensitive prostate cancer (mHSPC, n = 148) and mCRPC (n = 99), and showed that the bone scan index (BSI) was one of the significant prognostic factors for 3-year OS (PROSTAT-BSI study). mHSPC progressed to mCRPC (n = 101), for which 69 patients were treated with (n = 39) or without ARATAs (n = 30, prior to the approval of ARATAs). The 69 patients were divided into two groups according to patient factors, and these cohorts were further divided into two subgroups by usage of ARATAs. OS was compared between subgroups in each group.

RESULTS

The predictors were age (<71.4 years), serum levels of C-reactive protein (≥0.16 ng/ml) and alkaline phosphatase (≥548 U/L), time to PSA progression after ADT (<8.9 months), the lowest PSA level (≥1 ng/ml) after ADT, and the rate of PSA decline 3 months after ADT (<0.987), whereas hemoglobin levels, PSA before ADT, Gleason scores, existence of visceral metastases, and BSI were not.

CONCLUSIONS

The present study identified predictors for the effectiveness of ARATAs. The number of bone metastases (≒BSI), existence of visceral metastases, and Gleason scores, which were identified as high-risk factors in the LATITUDE study and disease volume in CHAARTED criteria, did not appear to be useful for predicting effectiveness from ARATAs.

Efficacy of Androgen Receptor-targeted Drugs After Prostate Cancer Recurrence With Bone Metastases: PROSTAT-BSI Sub-analysis

BACKGROUND/AIM

This study aimed to evaluate the therapeutic benefit of novel androgen receptor-targeted agents (ARTAs) in castration-resistant prostate cancer (CRPC) with bone metastases in Japan.

PATIENTS AND METHODS

In followup to our prospective observational study (PROSTAT-BSI) from 2012 to 2018 on metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic CRPC (mCRPC) before docetaxel initiation, we conducted this sub-analysis to investigate the benefit of ARTAs after clinical recurrence on overall survival (OS) in the real-world clinical setting in Japan. In this study, we compared patients who were treated with ARTA with those who received only vintage hormone therapy including docetaxel after clinical recurrence.

RESULTS

In the mHSPC group, 69 patients became mCRPC and were treated with or without ARTAs. No significant difference was observed in prostate-specific antigen (PSA) progression-free survival between the ARTA (+) and ARTA (-) groups; however, OS after clinical recurrence was significantly better in the ARTA (+) group than in the ARTA (-) group (median OS 31.9 vs. 23.0 months; p<0.01).

CONCLUSION

The ARTAs are beneficial even after mHSPC recurrence in Japanese patients in the real-world clinical setting. Since ARTAs are beneficial after clinical recurrence, it may be better to switch to ARTAs whenever necessary based on PSA response after combined androgen blockade therapy, considering the adverse effects and cost. This approach may be suitable to reduce overtreatment in Japanese patients with mHSPC.

Efficacy of New Therapies for Relapse After Docetaxel Treatment of Bone Metastatic Castration-resistant Prostate Cancer in Clinical Practice

BACKGROUND/AIM

To assess the efficacy of novel therapeutic agents, such as androgen receptor axis-targeted agents (ARATs) and cabazitaxel, for relapse of metastatic castration-resistant prostate cancer (mCRPC) after docetaxel in real-world practice, we performed a subanalysis using database from PROSTAT-BSI, a prospective observational study to evaluate the utility of software for quantifying bone metastases on bone scintigraphy.

PATIENTS AND METHODS

Patients with clinically relapsed mCRPC after docetaxel treatment who received the new agents (NEW group) and those who did not (standard of care, SOC group) were included; patients who received ARAT before DOC treatment were excluded. Overall survival (OS) after docetaxel treatment was compared between the NEW and SOC groups.

RESULTS

Patients in the NEW group had significantly better OS from the start of docetaxel than those in the SOC group (the median OS in NEW and SOC was 28.9 months vs. 14.5 months, respectively). Furthermore, regardless of the time from androgen-deprivation therapy to the start of docetaxel at mCRPC, the NEW group had a better OS from relapse after docetaxel than the SOC group.

CONCLUSION

In clinical practice, OS of patients with relapse after docetaxel was significantly improved in the NEW group over the SOC group.

Predictive factors for effectiveness from novel androgen-receptor-axis-targeted agents in patients with metastatic prostate cancer

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Background: About a half of men with prostate cancer progress to metastatic castration-resistant prostate cancer (mCRPC) one year after the initiation of androgen-deprivation therapy (ADT), whereas approximately 20 % of men keep the sensitivity to ADT more than 5 years. Several novel androgen-receptor-axis-targeted agents (ARATAs) were developed for the treatment of mCRPC, and improved overall survival (OS) in patients with mCRPC; however, to which patients these ARATAs were more beneficial is yet to be determined. We conducted this study to identify factors that predict effectiveness from ARATAs for mCRPC. Methods: We previously performed a multicenter study to determine prognostic factors including bone scan index (BSI) in patients with metastatic hormone sensitive prostate cancer (n = 148) and mCRPC (n = 99), which showed that BSI was one of the significant determinants of 3-year OS (PROSTAT-BSI study). The patients with mHSPC progressed to mCRPC (n = 101). Among these mCRPC patients, 69 patients received treatments with or without ARATAs, because the patients were recruited before and after approval of ARATAs in Japan. We used the data of the 69 patients to identify predictors for effective use of ARTA. The cohort was divided into two groups according to patient factors by several thresholds, and these two cohorts were further divided into two subgroups: those who received and did not receive ARATAs (abiraterone or enzalutamide). OS was compared between these two cohort groups to evaluate contribution of each factor. Categorical values were analyzed in the same way, although no threshold setting was required. Results: Factors, in which the significant treatment effect from ARATAs was observed between subgroups in only one group (eg. age < 71.4 vs age ≥ 71.4), were age ( < 71.4 years); serum levels of C-reactive protein (≥0.16 ng/mL), alkaline phosphatase (≥548 U/L), and type 1 collagen C-terminal telopeptide ( < 6.4 ng/mL); time to PSA progression after ADT ( < 8.9 months); lowest PSA level (≥1 ng/mL) after ADT; and rate of PSA decline 3 month after ADT ( <.987). Whereas, no significant difference was observed between two groups in cohorts divided by hemoglobin level, PSA before ADT, Gleason score, and BSI. Conclusions: This study identified the predictors of the effectiveness from ARATAs. In addition, the number of bone metastases (corresponding to BSI) and Gleason score, which were considered as high-risk factors in the LATITUDE study and disease volume in the CHAARTED criteria, may not be useful for predicting the effectiveness from ARATAs.

Enzalutamide versus abiraterone plus prednisolone before chemotherapy for Japanese castration-resistant prostate cancer patients: An investigator-initiated, multicenter, randomized controlled trial

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Background: Enzalutamide and abiraterone plus prednisolone demonstrated improvement of survival for castration-resistant prostate cancer (CRPC). However, it remains quite unclear which agent is better in terms of efficacy and safety for Asian patients. Methods: An investigator-initiated, multicenter, randomized controlled trial was conducted in Japan. CRPC patients before chemotherapy were randomly assigned to the enzalutamide or the abiraterone plus prednisolone arm (1:1). The primary endpoint is time to prostate-specific antigen (PSA) progression and secondary endpoints include PSA response rate (≥50% decline from baseline), overall survival, radiographic progression-free survival, and safety assessment. Results: Between February 20, 2015 and July 30, 2019, 203 patients were enrolled. After randomization, 92 in the enzalutamide and 92 in the abiraterone plus prednisolone arm were treated and analyzed. Time to PSA progression was not significantly different between arms (median 21.2 and 11.9 months in the enzalutamide and the abiraterone plus prednisolone arm, respectively; hazard ration 0.81, 95% CI 0.51-1.27, p = 0.1732). There was a significant difference in PSA response rate between arms (72% and 57% in the enzalutamide and the abiraterone plus prednisolone arm, respectively, p = 0.0425). There were no significant differences in overall and radiographic progression-free survival between arms (median 32.9 and 35.5months in the enzalutamide and the abiraterone plus prednisolone arm, respectively; hazard ration 1.17, 95% CI 0.72-1.88, p = 0.5290 and median 17.6 and 14.0 months in the enzalutamide and the abiraterone plus prednisolone arm, respectively; hazard ration 0.92, 95% CI 0.63-1.34, p = 0.6532). Grade ≥3 of adverse events were observed in 11% and 21% in the enzalutamide and the abiraterone plus prednisolone arm, respectively ( p = 0.1044). Conclusions: Enzalutamide did not show any survival benefits compared with abiraterone plus prednisolone but showed better PSA response rate with no significant differences of severe adverse event rate for Japanese CRPC patients. Our data suggest that antecedent use of enzalutamide to abiraterone plus prednisolone have potentially clinical benefits in Asian CRPC populations. Clinical trial information: UMIN000015529.

Novel metastatic burden-stratified risk model in de novo metastatic hormone-sensitive prostate cancer

The metastatic burden is a critical factor for decision-making in the treatment of metastatic hormone-sensitive prostate cancer (HSPC). This study aimed to develop and validate a novel risk model for survival in patients with de novo low- and high-burden metastatic HSPC. The retrospective observational study included men with de novo metastatic prostate cancer who were treated with primary androgen-deprivation therapy at 30 institutions across Japan between 2008 and 2017. We created a risk model for overall survival (OS) in the discovery cohort (n = 1449) stratified by the metastatic burden (low vs high) and validated its predictive ability in a separate cohort (n = 951). Based on multivariate analyses, lower hemoglobin levels, higher Gleason grades, and higher clinical T-stage were associated with poor OS in low-burden disease. Meanwhile, lower hemoglobin levels, higher Gleason grade group, liver metastasis, and higher extent of disease scores in bone were associated with poor OS in patients with high-burden disease. In the discovery and validation cohorts, the risk model using the aforementioned parameters exhibited excellent discriminatory ability for progression-free survival and OS. The predictive ability of this risk model was superior to that of previous risk models. Our novel metastatic burden-stratified risk model exhibited excellent predictive ability for OS, and it is expected to have several clinical uses, such as precise prognostic estimation.

Prognosis of patients with prostate cancer and bone metastasis from the Japanese Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index cohort study

Objective

To determine prognostic factors including the Bone Scan Index in prostate cancer patients receiving standard hormonal therapy and chemotherapy.

Methods

This multicenter Prostatic Cancer Registry of Standard Hormonal and Chemotherapy Using Bone Scan Index study involved 30 hospitals and enrolled 247 patients (age 71 ± 8 years) with metastatic hormone‐sensitive prostate cancer (n = 148) under hormone therapy and metastatic castration‐resistant prostate cancer (n = 99) under chemotherapy. The Bone Scan Index (%) was determined by whole‐body bone scintigraphy using ^99mTc‐methylenediphosphonate. Patients were classified into tertiles and binary groups, and predictors of all‐cause death including Bone Scan Index, prostate‐specific antigen, and bone metabolic markers were determined using survival and proportional hazard analyses.

Results

During a mean follow‐up period of 716 ± 404 days, 81 (33%) of the patients died, and 3‐year mortality rates were 20% and 52% in the metastatic hormone‐sensitive prostate cancer and metastatic castration‐resistant prostate cancer groups, respectively. Survival analysis showed that a Bone Scan Index >3.5% was a significant determinant of death in the metastatic hormone‐sensitive prostate cancer group, whereas prostate‐specific antigen >55 ng/mL before chemotherapy was a determinant of prognosis in the metastatic castration‐resistant prostate cancer group. A Bone Scan Index >3.5% was also associated with a high incidence of prostate‐specific antigen progression in the metastatic hormone‐sensitive prostate cancer group. Patients with metastatic hormone‐sensitive prostate cancer and a better Bone Scan Index response (>45%) to treatment had lower mortality rates than those without such response.

Conclusion

The Bone Scan Index and hot spot number are significant determinants of 3‐year mortality, and combining the Bone Scan Index with prostate‐specific antigen should contribute to the management of prostate cancer patients with bone metastasis.

Impact of histological variants on outcomes in patients with urothelial carcinoma treated with pembrolizumab: a propensity score matching analysis

OBJECTIVES

To assess the impact of histological variants on survival and response to treatment with pembrolizumab in patients with chemo-resistant urothelial carcinoma (UC).

PATIENTS AND METHODS

The medical records of 755 patients with advanced UC who received pembrolizumab were reviewed retrospectively. Patients were classified into pure UC (PUC) and each variant. Best overall response (BOR) and overall survival (OS) were compared between the groups using a propensity score matching (PSM).

RESULTS

Overall, 147 (19.5%) patients harboured any histological variant UC (VUC). After PSM, there were no significant differences in the objective response rate (ORR, 24.5% vs 17.3%, P = 0.098) or disease control rate (DCR, 36.7% vs 30.2%, P = 0.195) when comparing patients with any VUC and PUC. Furthermore, any VUC, as compared with PUC, was associated with a similar risk of death (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.68-1.20; P = 0.482). Squamous VUC, which was the most frequent variant in the cohort, had a comparable ORR, DCR and OS as compared with PUC or non-squamous VUC. The patients with sarcomatoid VUC (n = 19) had significantly better ORR (36.8%, P = 0.031), DCR (52.6%, P = 0.032), and OS (HR 0.37, 95% CI 0.15-0.90; P = 0.023) compared to patients with PUC.

CONCLUSIONS

The presence of variant histology did not seem to affect BOR or OS after pembrolizumab administration in patients with chemo-resistant UC. The patients with sarcomatoid VUC achieved favourable responses and survival rates compared to PUC.

Differential prognostic factors in low- and high-burden de novo metastatic hormone-sensitive prostate cancer patients

Metastatic burden is a critical factor for therapy decision-making in metastatic hormone-sensitive prostate cancer. The present study aimed to identify prognostic factors in men with high- or low-metastatic burden treated with primary androgen-deprivation therapy. The study included 2450 men with de novo metastatic prostate cancer who were treated with primary androgen-deprivation therapy at 30 institutions across Japan between 2008 and 2017. We investigated the prognostic value of various clinicopathological parameters for progression-free survival (PFS) and overall survival (OS) in patients stratified by low- or high-metastatic burden. Among the 2450 men, 841 (34.3%) and 1609 (65.7%) were classified as having low- and high-metastatic burden, respectively. Median PFS of the low- and high-burden groups were 44.5 and 16.1 months, respectively, and the median OS was 103.2 and 62.7 months, respectively. Percentage of biopsy-positive core, biopsy Gleason grade group, T-stage, and N-stage were identified to be differentially prognostic. M1a was associated with worse PFS than was M1b in the low-burden group, whereas lung metastasis was associated with better PFS and OS than was M1b in the high-burden group. Differential prognostic factors were identified for patients with low- and high-burden metastatic prostate cancer. These results may assist in decision-making to select the optimal therapeutic strategies for patients with different metastatic burdens.

Risk stratification for the prognosis of patients with chemoresistant urothelial cancer treated with pembrolizumab

The use of immune checkpoint inhibitors to treat urothelial carcinoma (UC) is increasing rapidly without clear guidance for validated risk stratification. This multicenter retrospective study collected clinicopathological information on 463 patients, and 11 predefined variables were analyzed to develop a multivariate model predicting overall survival (OS). The model was validated using an independent dataset of 292 patients. Patient characteristics and outcomes were well balanced between the discovery and validation cohorts, which had median OS times of 10.2 and 12.5 mo, respectively. The final validated multivariate model was defined by risk scores based on the hazard ratios (HRs) of independent prognostic factors including performance status, site of metastasis, hemoglobin levels, and the neutrophil‐to‐lymphocyte ratio. The median OS times (95% confidence intervals [CIs]) for the low‐, intermediate‐, and high‐risk groups (discovery cohort) were not yet reached (NYR) (NYR–19.1), 6.8 mo (5.8‐8.9), and 2.3 mo (1.2‐2.6), respectively. The HRs (95% CI) for OS in the low‐ and intermediate‐risk groups vs the high‐risk group were 0.07 (0.04‐0.11) and 0.23 (0.15‐0.37), respectively. The objective response rates for in the low‐, intermediate‐, and high‐risk groups were 48.3%, 28.8%, and 10.5%, respectively. These differential outcomes were well reproduced in the validation cohort and in patients who received pembrolizumab after perioperative or first‐line chemotherapy (N = 584). In conclusion, the present study developed and validated a simple prognostic model predicting the oncological outcomes of pembrolizumab‐treated patients with chemoresistant UC. The model provides useful information for external validation, patient counseling, and clinical trial design.

Potential effectiveness of local radiotherapy for extending survival and reducing symptomatic local events in patients with de novo metastatic prostate cancer

Objectives

To evaluate the association between the use of local radiotherapy (RT) with the survival of patients with de novo metastatic prostate cancer and symptomatic local events (SLEs).

Patients and methods

Patients were initially diagnosed with metastatic prostate cancer between 2008 and 2017 at 30 institutes in Japan. Prostate‐specific antigen (PSA) progression‐free survival (PSA‐PFS) under initial androgen deprivation therapy and overall survival (OS) was compared between patients receiving local RT (RT group) and no RT (no‐RT group) by multivariate Cox proportional hazard analyses. The occurrence rate of grade ≥2 SLEs was compared by multivariate logistic regression analyses. Propensity score matching (PSM) analyses were performed to compare PSA‐PFS and OS of the groups in the high and low metastatic burden cohort.

Results

Two hundred and five (7%) of 2829 patients received RT before PSA progression. Median PSA‐PFS and OS were significantly longer in the RT group than in the no‐RT group and the difference was significant in multivariate analyses (HR = 0.44, 95% CI = 0.33‐0.57 and HR = 0.40, 95% CI = 0.27‐0.60, respectively). The occurrence rate of grade ≥2 SLEs was significantly lower in the RT group (2%) than the no‐RT group (9%) and the difference was significant in multivariate analyses (HR = 0.28, 95% CI = 0.10‐0.76). Using PSM analyses, PSA‐PFS and OS remained significantly different (HR = 0.64, 95% CI = 0.46‐0.89 and HR = 0.47, 95% CI = 0.30‐0.72, respectively), between the RT (n = 182) and the no‐RT (n = 182) groups. The difference in OS was significant in the high metastatic burden cohort (HR = 0.55, 95% CI = 0.37‐0.81).

Conclusions

Addition of local RT to standard treatment for de novo metastatic prostate cancer patients tends to have the potential to extend survival, even in patients with high metastatic burden, and to reduce SLEs.

Evaluation of bone metastasis and prognosis of prostate cancer with bone metastasis during standard hormonal therapy and chemotherapy: A report of PROSTAT-BSI multicenter registry in Japan

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Background: Quantitative evaluation of the change of bone metastasis (bMet) has not been clearly defined during treatments in prostate cancer (PCa). As therapeutic effects of bMet have become quantified with scintigraphic bone scan index (BSI), we performed a nation-wide observational prospective study in patients who were treated by hormonal therapy (HTx) or chemotherapy (CTx). Methods: A total of 237 patients were recruited at 30 hospitals in Japan, and this report summarized baseline demographics and prognosis of 203 patients. All had bMet and underwent either standard HTx (group H) or docetaxel CTx (group C). Bone scans were performed with 99mTc-MDP. Patients were followed up for 3 years, and changes in biochemical and tumor markers during HTx and CTx were recorded in addition to skeletal-related events, recurrence, and death. Results: The basic characteristics of the patients (n=203) at the time of registration during December 2016 were as follows: mean age 71 ± 8 years; median BSI calculated on-site 3.0 ± 3.2% and median PSA was 265 ng/mL (22-2923 ng/mL) and 33 (3-537 ng/mL), for Group H and C (p=0.0014), respectively. BSI was comparable (H: 3.0 ± 3.4 vs C: 3.0 ± 2.8%, p=n.s.) between the two groups. A total of 54 patients (24%) died from PCa. BSI flare defined as increase at 3 months and decrease at 6 months was 13% and 31% (p<0.0069) for Groups H and C, respectively. When patients were classified into three groups with BSI <0.9 (low), 0.9-3.3 (intermediate), and >3.3% (high). Kaplan-Meier Survival analysis showed that mortality at 1100 days was 8%, 16%, and 35% for Group H (p=0.0097), and 50%, 55%, and 65% for Group C (p=ns) for the low, intermediate and high BSI group, respectively. In addition, patients who showed BSI decline >20% until 6 months showed better prognosis than those who did not (p<0.0001 and p= 0.038 and for Group H and C, respectively). Conclusions: The data of PROSTAT-BSI showed that BSI could be a good biomarker for prognosis in both Groups H and C, in particular for prognostic stratification of patients indicated for HTx. Six-month response of BSI by >20% indicated better prognosis in both groups. Clinical trial information: UMIN000007858.

Renal Cancer is Not Radioresistant: Slowly but Continuing Shrinkage of the Tumor After Stereotactic Body Radiation Therapy

Purpose:

To evaluate the safety and efficacy of stereotactic body radiation therapy for primary lesion of renal cell carcinoma with long-term and regular follow-up of tumor size and renal function.

Methods:

This prospective study included 13 patients treated with stereotactic body radiation therapy for primary lesion of stage I renal cell carcinoma between August 2007 and June 2016 in our institution. Diagnosis of renal cell carcinoma was made by 2 radiologists using computed tomography or magnetic resonance imaging. A dosage of 60 Gy in 10 fractions or 70 Gy in 10 fractions was prescribed. The higher dose was selected if dose constraints were satisfied. Tumor response on imaging examination, local progression-free rate, overall survival, and toxicity were assessed.

Results:

The mean follow-up period was 48.3 months (range: 11-108 months). The tumors showed very slow but continuous response during long-term follow-up. Three cases (23.1%) showed transient progression during the short follow-up. The mean duration until the day on which partial response was confirmed among the partial or complete response cases was 22.6 months (95% confidence interval, 15.3-30.0 months). Local progression-free rate was 92.3% for 3 years and overall survival rate 91.7% for 2 years and 71.3% for 3 years. Twelve cases (92.3%) had impaired renal function at baseline. Renal function decreased slowly and mildly in most of the cases, but 2 cases of solitary kidney showed grade 4 or 5 renal dysfunction.

Conclusion:

All renal tumors decreased in size slowly but continuously for years after stereotactic body radiation therapy. Renal cancer can be treated radically with stereotactic body radiation therapy as a radiosensitive tumor, but careful attention should be given in cases with solitary kidney.

The time-dependent variation of ATP release in mouse primary-cultured urothelial cells is regulated by the clock gene

AIMS

The sensation of bladder fullness (SBF) is triggered by the release of ATP. Therefore, the aim of this study was to investigate whether time-dependent changes in the levels of stretch-released ATP in mouse primary-cultured urothelial cells (MPCUCs) is regulated by circadian rhythm via clock genes.

METHODS

MPCUCs were derived from wild-type and Clock mutant mice (Clock^Δ19/Δ19 ), presenting a nocturia phenotype. They were cultured in elastic silicone chambers. Stretch-released ATP was quantified every 4 h by ATP photon count. An experiment was also performed to determine whether ATP release correlated with the rhythm of the expression of Piezo1, TRPV4, VNUT, and Connexin26 (Cx26) in MPCUCs regulated by clock genes with circadian rhythms. MPCUCs were treated with carbenoxolone, an inhibitor of gap junction protein; were derived from VNUT-KO mice; or treated with Piezo1-siRNA, TRPV4-siRNA, and Cx26-siRNA.

RESULTS

Stretch-released ATP showed time-dependent changes in wild-type mice and correlated with the rhythm of the expression of Piezo1, TRPV4, VNUT, and Cx26. However, these rhythms were disrupted in Clock^Δ19/Δ19 mice. Carbenoxolone eliminated the rhythmicity of ATP release in wild-type mice. However, time-dependent ATP release changes were maintained when a single gene was deficient such as VNUT-KO, Piezo1-, TRPV4-, and Cx26-siRNA.

CONCLUSIONS

ATP release in the bladder urothelium induces SBF and may have a circadian rhythm regulated by the clock genes. In the bladder urothelium, clock gene abnormalities may disrupt circadian ATP release by inducing Piezo1, TRPV4, VNUT, and Cx26. All these genes can trigger nocturia.

The oscillation of intracellular Ca2+ influx associated with the circadian expression of Piezo1 and TRPV4 in the bladder urothelium

We previously showed that bladder functions are controlled by clock genes with circadian rhythm. The sensation of bladder fullness (SBF) is sensed by mechano-sensor such as Piezo1 and TRPV4 in the mouse bladder urothelium. However, functional circadian rhythms of such mechano-sensors remain unknown. To investigate functional circadian changes of these mechano-sensors, we measured circadian changes in stretch-evoked intracellular Ca²⁺ influx ([Ca²⁺] _i ) using mouse primary cultured urothelial cells (MPCUCs). Using Ca²⁺ imaging, stretch-evoked [Ca²⁺] _i was quantified every 4 h in MPCUCs derived from wild-type (WT) and Clock ^Δ19/Δ19 mice, which showed a nocturia phenotype. Furthermore, a Piezo1 inhibitor GsMTx4 and a TRPV4 inhibitor Ruthenium Red were applied and stretch-evoked [Ca²⁺] _i in MPCUCs was measured to investigate their contribution to SBF. Stretch-evoked [Ca²⁺] _i showed a circadian rhythm in the WT mice. In contrast, Clock ^Δ19/Δ19 mice showed disrupted circadian rhythm. The administration of both GsMTx4 and Ruthenium Red eliminated the circadian rhythm of stretch-evoked [Ca²⁺] _i in WT mice. We conclude that SBF may have a circadian rhythm, which is created by functional circadian changes of Piezo1 and TRPV4 being controlled by clock genes to be active during wakefulness and inactive during sleep. Abnormalities of clock genes disrupt SBF, and induce nocturia.

Enzalutamide versus abiraterone as a first-line endocrine therapy for castration-resistant prostate cancer (ENABLE study for PCa): a study protocol for a multicenter randomized phase III trial

BACKGROUND

Both enzalutamide and abiraterone have demonstrated improved radiographic progression-free and overall survival for castration-resistant prostate cancer (CRPC) compared with placebo controls before docetaxel treatment in phase III studies. These oral agents target androgen and androgen receptor signaling and are thought to be less toxic than chemotherapy. Cross-resistance to these agents was recently reported because of their similar mechanism of action, and it is important to assess which agent is more effective to use initially for CRPC.

METHODS/DESIGN

The present study is a phase III, investigator-initiated, multicenter, head-to-head, randomized controlled trial investigating enzalutamide vs. abiraterone as a first-line treatment for CRPC patients. Patients will be randomly assigned to an enzalutamide or an abiraterone treatment group. The primary endpoint is the time to prostate-specific antigen progression. The target sample size is set at 100 patients per group (total, 200 patients). The study duration is 5 years, and the duration for recruitment is 2 years and 6 months.

DISCUSSION

Thus far, there have been no prospective head-to-head studies comparing enzalutamide and abiraterone. This ENABLE study will clarify which agent should be prioritized for CRPC patients and enable clinicians to decide the appropriate treatment before chemotherapy.

TRIAL REGISTRATION

University hospital Medical Information Network (UMIN) Center identifier UMIN000015529 . Registrated 11/1/2014.

Carbenoxolone inhibits TRPV4 channel-initiated oxidative urothelial injury and ameliorates cyclophosphamide-induced bladder dysfunction

Carbenoxolone (CBX) is a clinically prescribed drug for the treatment of digestive ulcer and inflammation. It is also a widely used pharmacological inhibitor of several channels in basic research. Given that the overactivity of several channels, including those inhibitable by CBX, underlies bladder dysfunction, we tested the potential therapeutic application and mechanism of CBX in the treatment of voiding dysfunction. In a mouse model of cystitis induced by cyclophosphamide (CYP), CBX administration prevented the CYP‐elicited increase in bladder weight, oedema, haemorrhage, and urothelial injury. CBX also greatly improved micturition pattern, as manifested by the apparently decreased micturition frequency and increased micturition volume. Western blot results showed that CBX suppressed CYP‐induced increase in protein carbonyls, COX‐2, and iNOS. Further analysis using cultured urothelial cells revealed that acrolein, the major metabolite of CYP, caused protein oxidation, p38 activation, and urothelial injury. These effects of acrolein were reproduced by TRPV4 agonists and significantly prevented by antioxidant NAC, p38 inhibitor SB203580, TRPV4 antagonist RN‐1734, and CBX. Further studies showed that CBX potently suppressed TRPV4 agonist‐initiated calcium influx and subsequent cell injury. CBX attenuated CYP‐induced cystitis in vivo and reduced acrolein‐induced cell injury in vitro, through mechanisms involving inhibition of TRPV4 channels and attenuation of the channel‐mediated oxidative stress. CBX might be a promising agent for the treatment of bladder dysfunction.

Persistent Urinary Incontinence After Nephrectomy: A Case of Inverted-Y Ureteral Duplication with Ectopic Ureteral Insertion into the Vagina

Inverted-Y ureteral duplication is one of the rarest anomalies of ureteral branching. We encountered a 20-year-old female patient with persistent incontinence even after nephrectomy for ectopic ureteral insertion into the vagina. She had inverted-Y ureteral duplication between the bladder and vagina, and urine was being transported from the bladder to the vagina. To the best of our knowledge, this is a rare case of inverted-Y ureteral duplication with ectopic ureteral insertion into the vagina as well as the ureter into the bladder, which became apparent due to persistent urinary incontinence even after nephrectomy.

PO-16 - ASK1 regulates tumor lung metastasis and platelet functions

INTRODUCTION

Apoptosis signal-regulating kinase 1 (ASK1) is a MAP3K in the JNK and p38 MAPK pathways and responds to various stresses. Accumulating evidence indicates that ASK1 plays important roles in tumorigenesis by regulating apoptosis and inflammation. However, little is known about ASK1's roles in tumor metastasis.

AIM

To investigate ASK1's roles in tumor metastasis.

MATERIALS AND METHODS

We performed experimental lung metastasis model by intravenous injection of Lewis lung carcinoma cells constitutively expressing luciferase (3LL-Luc2 cells). As for the analysis of platelet functions, tail bleeding assay and ferric chloride-induced thrombosis model were utilized.

RESULTS

We measured the transition of luciferase activity of the lung lysates up to 7 days as an indicator of lung metastasis. ASK1-/- mice showed markedly lower luciferase activity as early as 3 hours after injection compared to WT mice; hence ASK1 appears to be involved in the early stage of tumor lung metastasis, which is prior to the extravasation of tumor cells. Platelets aggregate and adhere to tumor cells in the early stage and are known to support hematogenous metastasis. ASK1-/- mice were normal in hematological parameters including platelet number, while analysis by western blot revealed that platelets of ASK1-/- mice exhibited markedly reduced phosphorylation of JNK and p38, both of which have been reported to regulate platelet functions such as platelet aggregation. We found that platelets of ASK1-/- mice were less responsive to specific aggregation agonists and that ASK1-/- mice showed bleeding tendency and defect in thrombosis. These phenotypes were also observed in megakaryocyte and platelet-specific ASK1 deficient mice.

CONCLUSIONS

It is suggested that impaired platelet functions caused by ASK1 deficiency in platelets may attenuate tumor lung metastasis.

Suramin inhibits antibody binding to cell surface antigens and disrupts complement-mediated mesangial cell lysis

Suramin inhibits immune responses and protects cells against inflammatory cell injury. However, little is known about its mechanisms. Using an in vitro model of glomerular mesangial cell (MC) lysis induced by antibodies plus complement, we investigated the potential protective effects and mechanisms of suramin on immunologic cell injury. Exposure of rat MCs to anti-Thy-1 antibody plus complement or anti-MC rabbit serum caused complement-dependent cell lysis, which was blocked by suramin and its structural analogue NF023 and NF049, but not by PPADS, an antagonist of purinergic receptors. Addition of exogenous ATP also failed to affect MC lysis. Further analysis revealed that suramin interfered with antibody binding to cell membrane antigens and suppressed antibody-induced phosphorylation of several proteins, including p38. Inhibition of p38 with chemical inhibitor significantly attenuated cell injury. Collectively, our results indicate that suramin protects cells against antibody-initiated and complement-dependent cell injury through inhibition of antibody binding to cell surface antigens and suppression of p38 activation. Our study thus provides novel mechanistic insights into the actions of suramin and suggests that suramin might be used to treat certain immune diseases.

AMPK Suppresses Connexin43 Expression in the Bladder and Ameliorates Voiding Dysfunction in Cyclophosphamide-induced Mouse Cystitis

Bladder voiding dysfunction is closely related to local oxidation, inflammation, and enhanced channel activities. Given that the AMP-activated protein kinase (AMPK) has anti-oxidative, anti-inflammatory and channel-inhibiting properties, we examined whether and how AMPK affected bladder activity. AMPK activation in rat bladder smooth muscle cells (BSMCs) using three different AMPK agonists resulted in a decrease in connexin43 (Cx43) expression and function, which was associated with reduced CREB phosphorylation, Cx43 promoter activity and mRNA expression, but not Cx43 degradation. Downregulation of CREB with siRNA increased Cx43 expression. A functional analysis revealed that AMPK weakened BSMC contraction and bladder capacity. AMPK also counteracted the IL-1β- and TNFα-induced increase in Cx43 in BSMCs. In vivo administration of the AMPK agonist AICAR attenuated cyclophosphamide-initiated bladder oxidation, inflammation, Cx43 expression and voiding dysfunction. Further analysis comparing the responses of the wild-type (Cx43(+/+)) and heterozygous (Cx43(+/-)) Cx43 mice to cyclophosphamide revealed that the Cx43(+/-) mice retained a relatively normal micturition pattern compared to the Cx43(+/+) mice. Taken together, our results indicate that AMPK inhibits Cx43 in BSMCs and improves bladder activity under pathological conditions. We propose that strategies that target AMPK can be developed as novel therapeutic approaches for treating bladder dysfunction.

[INTRAVESICAL MIGRATION OF A HEM-O-LOK CLIP AFTER ROBOT-ASSISTED RADICAL PROSTATECTOMY: A CASE REPORT]

The Hem-o-lok clips (HOLC) is frequently used for hemostasis of the lateral pedicles in robot-assisted prostatectomy (RARP) and laparoscopic radical prostatectomy (LRP). We report a rare post-operative complication, the migration of a HOLC into the bladder leading to calculus formation after RARP. A 54 year-old man underwent RARP with nerve- sparing procedure with HOLCs in the left neurovascular bundle. Three months later, he was referred to our hospital for pollakisuria and spontaneous hematuria. Abdominal ultrasonographic examination and computed tomography (CT) demonstrated a bladder stone that was 7 mm in diameter. On cystourethroscopy, he was noted to have a yellow-colored stone at 9 o'clock position of vesicourethral anastomosis. A cystolithotripsy for a bladder stone was performed until the surface of it was broken. A HOLC with a calculus was revealed and retrieved by stone forceps through the urethra. Since then, Intravesical migration of a HOLC has not been observed.

Postoperative chylothorax in congenital diaphragmatic hernia

INTRODUCTION

The mechanisms responsible for postoperative chylothorax in Congenital Diaphragmatic Hernia (CDH) patients remain unclear. The aim of the present study was to examine the clinical features of CDH that may contribute to an association with postoperative chylothorax.

MATERIAL AND METHODS

198 neonates with CDH, in whom surgical repair of a diaphragmatic defect was performed between 1981 and 2008, were retrospectively studied. The patients were divided into 2 groups; patients with postoperative chylothorax (group I, n=11) and patients without postoperative chylothorax (group II, n=187). The clinical findings were compared between group I and group II to investigate potential predictive parameters for an association with chylothorax. Moreover, the clinical findings and treatments were evaluated in patients with chylothorax.

RESULTS

11 of the 198 infants (5.5%) developed a chylothorax. Although the incidence of a prenatal diagnosis was slightly higher in group I, no relationship with other clinical features was found which would indicate the severity of CDH or the occurrence of postoperative chylothorax. Treatment for chylothorax was drainage alone in 2 cases, total parenteral nutrition with drainage in 8 infants and additional intrathoracic OK-432 infusion in 1 patient. No patients required surgical intervention for chylothorax. No recurrences were observed in this patient series.

CONCLUSIONS

It was concluded that postoperative chylothorax is not rare in infants after CDH repair. However, no statistically significant predictive parameters for chylothorax were identified, except for the presence of a prenatal diagnosis.

[Two cases of infants with acute renal failure due to bilateral obstructive ureteral stones associated with rotavirus gastroenteritis]

We report on 2 infants with acute renal failure caused by bilateral obstructive ureteral stones associated with rotavirus gastroenteritis. A 28-month boy and a 13-month boy with several days history of watery diarrhea and vomiting were referred to our hospital because of anuria. They were diagnosed acute post-renal failure due to obstructive bilateral ureteral stones based on the findings of ultrasound scan and computed tomography. Immediately, percutaneous nephrostomy tubes were inserted for urinary drainage, serum levels of creatinine and uric acid returned to normal within several days. Sandy stones were excreted through the nephrostomy tubes with urine after urinary alkalization, which were proved to be mainly ammonium acid urate. Ammonium acid urate is rare in developed countries, but some cases of bilateral urolithiasis causing acute renal failure in infants with rotavirus gastroenteritis were reported in recent years. It has been known that the cause of acute renal failure is renal azotemia resulting from sustained hypovolemia, but post-renal causes due to ammonium acid urate stones should be taken into consideration.

Efficacy and safety of torasemide in children with heart failure

OBJECTIVE

To examine the efficacy and safety of torasemide in children with chronic heart failure (HF).

METHODS

102 children with chronic HF who had received oral torasemide were analysed. Of these, 62 (de novo group) were newly diagnosed as having HF and were given torasemide as a diuretic. The remaining 40 (replacement group) had been given furosemide for >3 months before the study, and furosemide was then replaced with torasemide. Clinical signs and symptoms of HF (assessed as the HF index), humoral factors and serum potassium concentrations before torasemide treatment were compared with those obtained 3-4 weeks after torasemide treatment. Patients were also monitored for adverse effects.

RESULTS

In the de novo group, torasemide significantly improved the HF index with concomitant improvement in plasma brain natriuretic peptide concentration (median (interquartile range) 52 (51) vs 43 (49) pg/ml). In a randomly selected group of 25 de novo patients with ventricular septal defect, echocardiography showed that torasemide significantly improved left ventricular geometry and function. In the replacement group, brain natriuretic peptide concentrations were also significantly decreased from 50 (104) to 45 (71) pg/ml after substitution of torasemide, but the HF index showed only a tendency for improvement (p = 0.07). Torasemide also had a potassium-sparing effect (de novo group, no change in potassium concentration; replacement group, significant increase from 4.2 (0.5) to 4.3 (0.5) mEq/l), and caused a significant rise in serum aldosterone concentration, consistent with the anti-aldosterone effect of this drug. Serum concentrations of sodium and uric acid had not changed after torasemide treatment, and there were no serious adverse events that necessitated drug withdrawal.

CONCLUSION

Torasemide can be safely used, and appears to be effective for treatment of HF in children. Future clinical trials are warranted to verify the present results.

Computer-assisted linearization of the von Krogh Curve for the measurement of serum complement titre

Computer simulations of complement titre measurement in sera by linearizing the sigmoidal curve of complement dose response were performed, to simplify the logarithmic calculations of CH50 values. CH50 titres of large variety of human sera including healthy donors and immune deficiency patients were estimated. The values obtained were compared with the hand-simulated results using the Y/(1-Y) conversion table and a log-log graphic paper. Using computer simulation, CH50 can be determined with great ease.

Decreased expression of G protein-coupled receptor kinases in the detrusor smooth muscle of human urinary bladder with outlet obstruction

AIM

We examine the expression of mRNA of G protein-coupled receptor kinase (GRK) subtypes and muscarinic acetylcholine receptor (M) subtypes in the detrusor smooth muscle of the human urinary bladder. Furthermore, we confirm the presence and the localization of GRK proteins in the detrusor smooth muscle of the obstructed bladder in comparison with the control bladder.

METHODS

Detrusor smooth muscle tissues of the human urinary bladder were obtained from 12 male patients; 6 patients did not have bladder outlet obstruction, and the other 6 patients had bladder outlet obstruction. Portions of the dome or anterior wall of the urinary bladder were used for the present study. Reverse transcription/polymerase chain reaction for GRK2, M2 and M3 was performed using total RNA extracted from human urinary bladder detrusor. Antibodies to GRK2, GRK3 and GRK4 were used to confirm the presence of the protein product in the human urinary bladder using immunohistochemical staining and the western blotting technique.

RESULTS

All complementary DNA (cDNA) transcribed from three different mRNA (M2, M3 and GRK2) were successfully amplified and size-fractionated. The expression of GRK2 protein was strong in the human bladder detrusor, but was significantly weakened by western blotting in obstructed bladder in comparison with control bladder.

CONCLUSIONS

Failure in desensitization mechanisms of muscarinic acetylcholine receptors might be related to storage symptom elicited by overactivity in obstructed bladder with benign prostatic hyperplasia.

EP2, a receptor for PGE2, regulates tumor angiogenesis through direct effects on endothelial cell motility and survival

Prostaglandin E2 (PGE2), a major cyclooxygenase (COX) metabolite, plays important roles in tumor biology. We studied the role of EP2, a receptor for PGE2, in tumor angiogenesis using EP2 knockout mice. We found that deletion of the EP2 receptor impaired tumor angiogenesis and this finding was confirmed by an in vivo corneal angiogenesis model and an ex vivo aortic ring assay. To further characterize the cellular mechanisms of the EP2 receptor in angiogenesis, we isolated primary pulmonary endothelial cells (ECs) from wild-type (wt) and EP2-/- mice and observed that EP2-/- ECs exhibited defects in vascular branch formation when compared to wt ECs. In addition, EP2-/- ECs showed impaired cell motility on collagen-coated surface and they responded poorly to PGE2-induced cell migration compared to control cells. However, no difference in cell proliferation was observed between the EP2-/- and wt Ecs. In addition, EP2-/- ECs were more susceptible to apoptosis than wt cells under growth factor depletion conditions. Collectively, our data demonstrate that EP2 signaling in endothelium directly regulates tumor angiogenesis by contributing to cell survival and endothelial cell motility. Moreover, our finding suggests that EP2 is a major receptor in PGE2-mediated cell motility in ECs.

Moderate increase of mean daily temperature adversely affects fruit set of Lycopersicon esculentum by disrupting specific physiological processes in male reproductive development

BACKGROUND AND AIMS

Global warming is gaining significance as a threat to natural and managed ecosystems since temperature is one of the major environmental factors affecting plant productivity. Hence, the effects of moderate temperature increase on the growth and development of the tomato plant (Lycopersicon esculentum) were investigated.

METHODS

Plants were grown at 32/26 degrees C as a moderately elevated temperature stress (METS) treatment or at 28/22 degrees C (day/night temperatures) as a control with natural light conditions. Vegetative growth and reproductive development as well as sugar content and metabolism, proline content and translocation in the androecium were investigated.

KEY RESULTS

METS did not cause a significant change in biomass, the number of flowers, or the number of pollen grains produced, but there was a significant decrease in the number of fruit set, pollen viability and the number of pollen grains released. Glucose and fructose contents in the androecium (i.e. all stamens from one flower) were generally higher in the control than METS, but sucrose was higher in METS. Coincidently, the mRNA transcript abundance of acid invertase in the androecium was decreased by METS. Proline contents in the androecium were almost the same in the control and METS, while the mRNA transcript level of proline transporter 1, which expresses specifically at the surface of microspores, was significantly decreased by METS.

CONCLUSIONS

The research indicated that failure of tomato fruit set under a moderately increased temperature above optimal is due to the disruption of sugar metabolism and proline translocation during the narrow window of male reproductive development.

Gene and protein expression profiles of prostaglandin E2 receptor subtypes in the human corpus cavernosum

Prostaglandin E1 leads to penile erection, mainly via prostaglandin E2 (EP) receptors. This study aimed to identify the expression profile of EP receptor genes in human corpus cavernosum. Using the quantitative real-time reverse transcription polymerase chain reaction, the mRNA levels of EP receptor subtypes were measured. In addition, expressions of EP receptor subtype proteins were determined by immunohistochemical method. Among the four subtypes, EP4 receptor mRNA expression was the highest, and EP2 receptor mRNA followed, whereas EP1 and EP3 receptor mRNAs were hardly observed. Expression level of EP4 receptor mRNA was significantly higher than that of EP2 receptor mRNA. Expression of both EP2 and EP4 receptor proteins were clearly detected in the cavernous smooth muscle. These results may suggest that EP4 receptor plays an important role among four EP receptor subtypes for relaxation of smooth muscle in the human corpus cavernosum.

Overexpression of epithelial sodium channels in epithelium of human urinary bladder with outlet obstruction

OBJECTIVES

To examine whether the epithelial sodium channel (ENaC) is expressed in the human urinary bladder and how its expression changes in association with outlet obstruction. Detrusor instability occurs in association with bladder outlet obstruction. The increase of afferent activity is one of the possible mechanisms for this detrusor instability. The ENaC expressed in mammals has been implicated in various mechanosensory functions.

METHODS

Specimens of urinary bladder mucosa were obtained from 9 controls and 9 patients with bladder outlet obstruction verified by the International Prostate Symptom Score, prostate volume, and urodynamic tests. In 7 patients with outlet obstruction, involuntary detrusor contraction was demonstrated. The expression and localization of ENaC proteins was examined using immunofluorescent staining. The quantification of ENaC gene expression was assessed by real-time reverse transcriptase-polymerase chain reaction.

RESULTS

The alpha-ENaC, beta-ENaC, and gamma-ENaC proteins were expressed in human urinary bladder epithelium with outlet obstruction, and the alpha-ENaC and gamma-ENaC proteins were virtually unstained in the control bladders. Alpha-ENaC, beta-ENaC, and gamma-ENaC mRNA were detected in 1, 6, and 4 of 9 control bladders, respectively. Each ENaC mRNA was clearly present in all obstructed bladders. The expression levels of each subunit in the obstructed bladders were significantly greater than those in controls. The quantified ENaC expression correlated significantly with the storage symptom score.

CONCLUSIONS

The ENaC expressed in the bladder epithelium might be implicated in the mechanosensory transduction in the bladder afferent pathways, thereby inducing detrusor instability by outlet obstruction.

Diagnosis and treatment of voiding symptoms

Lower urinary tract symptoms (LUTS) are associated with lower urinary tract dysfunction. Symptoms are the subjective indicator of a disease or change in condition as perceived by the patient, caregiver, or partner and may lead the individual to seek help from health care professionals. LUTS are usually qualitative and, therefore, cannot usually be used to make a definitive diagnosis. LUTS also can indicate pathologies other than lower urinary tract dysfunction, such as urinary infection. LUTS are divided into 7 groups: storage, voiding (obstructive), postmicturition symptoms and 4 others. Voiding symptoms, which are caused by lower urinary tract obstruction, include slow stream, splitting or spraying, intermittency, hesitancy, straining, and terminal dribble. Postmicturition symptoms, which are experienced immediately after micturition, consist of the feeling of incomplete emptying and postmicturition dribble. Postmicturition dribble describes the involuntary loss of urine immediately after the individual has finished passing urine; in men, usually after leaving the toilet and in women, after rising from the toilet. Hence, postmicturition dribble is elicited by different situations or is considered as having different implications. For example, although postmicturition dribble usually implies incomplete emptying (voiding symptoms) in elderly men with benign prostatic hyperplasia, postmicturition dribble is often considered as urinary incontinence (a storage symptom) in many patients, even with bladder outlet obstruction. In such cases, detailed history taking and further evaluation, such as urinary flowmetry, postvoid residual volume, and comprehensive urodynamic evaluation, should be performed as appropriate. If no urodynamic abnormalities of either the detrusor or the outlet can be detected despite significant LUTS, factors unrelated to the lower urinary tract may be responsible for the voiding symptoms.

The methylentetrahydrofolate reductase C677T point mutation is a risk factor for vascular access thrombosis in hemodialysis patients

BACKGROUND

Many reports indicate that a high homocysteine (Hcy) level is a potential risk factor for such thrombotic diseases as arteriosclerosis, myocardial infarction, and cerebral infarction in healthy individuals or hemodialysis (HD) patients. The methylentetrahydrofolate reductase (MTHFR) C677T polymorphism has been reported to be closely related to plasma Hcy level.

METHODS

Using a cross-sectional design in this study, the relationship between arteriovenous fistula (AVF) obstruction and the MTHFR C677T point mutation was examined in 337 HD patients.

RESULTS

Results of multivariate analysis showed no significant influence of age, HD therapy duration, sex, or the presence of diabetes mellitus, cerebral infarction, or myocardial infarction. Only the presence of the MTHFR C677T polymorphism yielded a significant difference. Percentages of patients who experienced AVF obstruction were as follows: CC (12.6%), CT (20.3%), and TT (31.8%). The number of those who experienced obstruction was significantly larger with the TT than CC (P < 0.01). Moreover, total obstruction episode ratios were as follows: CC, 1 in 107.21 episodes/patient-month; CT, 1 in 74.08 episodes/patient-month; and TT, 1 in 50.33 episodes/patient-month. Episode percentages tended to be greater when the degree of mutation was greater, and a significant difference was observed between the CC and TT alleles (P < 0.01).

CONCLUSION

Although AVF obstruction is affected by numerous factors, there was a strong relationship between MTHFR C677T mutation and AVF obstruction. These findings suggest that the MTHFR C677T point mutation could serve as an important indicator in identifying susceptibility to AVF obstruction.