Biomedical subjects

Nobuhisa Ishii

Publications and source records attributed to Nobuhisa Ishii.

15 recordsLinked to original sources

PubMed2006

Vascular endothelial growth factor restores erectile function through modulation of the insulin-like growth factor system and sex hormone receptors in diabetic rat.

Previous studies have shown that intracavernous injection of vascular endothelial growth factor (VEGF) restored erectile function in diabetic rats. However, the mechanism of VEGF in diabetes-related erectile dysfunction (ED) has not been fully investigated. We hypothesize that intracavernous injection of VEGF may reverse diabetes-related ED through modulation of the insulin-like growth factor system and sex hormone receptors. To test this hypothesis the erectile function of treated and control rats was analyzed by measurement of intracavernous pressure (ICP) following electrostimulation of the cavernous nerves. Mean ICP was significantly lower in non-treated diabetic rats compared to controls. After VEGF injection, ICP was significantly higher than in non-treated diabetic rats. IGFBP-3 mRNA and protein expression was significantly higher in non-treated diabetic rat crura than controls, while VEGF-treated animals had control levels. ER-beta and PR mRNA and protein expression was significantly lower in non-treated diabetic rat crura. After VEGF injection, ER-beta and PR mRNA and protein expression was similar to control levels. Expression of AR and ER-alpha was the same in all groups. These findings suggest that orthotopic injection of VEGF may improve the functional recovery of diabetes-related ED through modulation of the insulin-like growth factor system and sex hormone receptors. To our knowledge, this is the first study demonstrating that VEGF treatment restores erectile function through restoration of the insulin-like growth factor system and sex hormone receptor genes at the mRNA and protein levels in diabetic rat crura. These results may be important in understanding the pathogenesis of diabetes-related ED and also in providing better strategies for management of this disease.

Animals↗

PubMed2006

Efficacy and safety of tadalafil 5, 10, and 20 mg in Japanese men with erectile dysfunction: results of a multicenter, randomized, double-blind, placebo-controlled study.

OBJECTIVES: To investigate the efficacy and safety of tadalafil, a phosphodiesterase type 5 inhibitor, in Japanese men with erectile dysfunction (ED). METHODS: This multicenter, randomized, double-blind, placebo-controlled, 12-week study enrolled 343 Japanese men with ED. The men were stratified into those with mild, moderate, or severe ED and then randomly assigned 1:1:1:1 to placebo and 5 mg, 10 mg, and 20 mg tadalafil. Co-primary outcomes were the International Index of Erectile Function erectile function domain score, the percentage of "yes" responses to the Sexual Encounter Profile Diary Questions 2 and 3, and tolerability. Secondary outcomes included the International Index of Erectile Function intercourse satisfaction and overall satisfaction domain scores and the percentage of "yes" responses to a global assessment question. RESULTS: The least square mean change from baseline was 7.5, 9.1, and 9.4 for 5, 10, and 20 mg tadalafil versus 2.1 for placebo for the International Index of Erectile Function erectile function domain; 28.5, 36.0, and 36.5 for 5, 10, and 20 mg tadalafil versus 8.6 for placebo for Sexual Encounter Profile question 2; and 34.3, 47.3, and 50.8 for 5, 10, and 20 mg tadalafil versus 12.3 for placebo for Sexual Encounter Profile question 3, respectively (P <0.001 for all doses and all measures). Patients taking tadalafil had significantly greater changes from baseline for the intercourse satisfaction and overall satisfaction domains compared with patients taking placebo (P <0.001). Also, 76.5%, 81.4%, and 83.7% of patients taking 5, 10, and 20 mg tadalafil, respectively, reported improved erections (global assessment question) versus 31.4% of patients taking placebo (P <0.001). Most (98%) treatment-emergent adverse events were mild or moderate in severity. One patient (tadalafil 5 mg) discontinued because of an adverse event (ureteral calculus). Of the 343 patients, 302 (88%) completed the study. No deaths were reported. CONCLUSIONS: All doses of tadalafil studied were efficacious and well tolerated in Japanese men with ED.

Asian People↗

PubMed2006

Vardenafil 20-mg demonstrated superior efficacy to 10-mg in Japanese men with diabetes mellitus suffering from erectile dysfunction.

AIM: Vardenafil is a highly selective and potent phosphodiesterase type-5 inhibitor for the treatment of erectile dysfunction (ED). The efficacy of vardenafil has been demonstrated in a broad range of ED populations, but has not yet been assessed in Japanese patients with diabetes mellitus (DM), although DM is frequently associated with difficult-to-treat ED. This is the first study to investigate whether high-dose vardenafil (20 mg) can demonstrate superior efficacy to the usual dose (10 mg) in this subpopulation in Japan. METHODS: The study was a randomized, placebo-controlled, double-blind, multi-centre, parallel group comparison 12-week study. Following 4 weeks observation period, 778 patients aged 26-64 years old with ED and DM (HbA1c >12% at screening was excluded) both of more than 3 years duration were randomly allocated to one of the three groups, vardenafil 10 mg, 20 mg, or placebo (randomization ratio 3:3:1). Erectile function (EF) domain score of the International Index of Erectile Function was estimated as the primary efficacy parameter. RESULTS: Vardenafil 10 and 20 mg both significantly improved the EF domain score from 13.6 and 13.9 at baseline to 21.8 and 22.9 at last observation carried forward (LOCF), respectively, compared to placebo (13.7 at baseline to 16.3 at LOCF; p<0.0001). In addition, vardenafil 20 mg demonstrated superior efficacy to 10 mg (p<0.05), and the difference was more evident in severe ED patients (baseline EF domain score <11). The safety profile was comparable between these two doses (drug-related adverse events: 6.6, 22.0 and 24.2% in placebo, vardenafil 10 mg, and 20 mg arms, respectively). The most common adverse events were hot flush, headache and nasal congestion, which were mild in intensity and transient, and are known to be common to PDE5 inhibitors. CONCLUSION: In Japanese men with DM and ED, vardenafil 10 mg and 20 mg were effective in improving erectile function with comparable safety profiles. Vardenafil 20 mg demonstrated superior efficacy compared with 10 mg, suggesting incremental clinical benefit in using the higher dose in this difficult-to-treat population.

Adult↗

PubMed2006

Catechol-O-methyltransferase gene polymorphisms in benign prostatic hyperplasia and sporadic prostate cancer.

Various carcinogenic metabolites, including catechol estrogens, play a role in malignant transformation. An enzyme that is capable of neutralizing the genotoxic effects of these compounds is catechol-O-methyltransferase (COMT). A variant form of this enzyme has been shown to reduce its activity by up to 4-fold; thus, we hypothesize that single nucleotide polymorphisms of the COMT gene can be a risk factor for benign prostatic hyperplasia (BPH) and prostate cancer. To test this hypothesis, the genetic distribution of three different COMT polymorphisms at codon 62 (C-->T), codon 72 (G-->T), and codon 158 (G-->A) were analyzed in 131 normal healthy subjects, 134 BPH, and 178 sporadic prostate cancer samples from a Japanese population. Results of these experiments show that the variant genotype at codon 62 (P = 0.060) and codon 158 (P = 0.047) are risk factors for prostate cancer but not BPH when compared with normal controls. Odds ratio (OR) and 95% confidence interval (95% CI) for cancer were 3.24 and 1.38 to 7.61, respectively, for codon 62 T/T genotype when compared with wild type. At codon 158, the A/A variant for cancer had an OR of 3.00 with a 95% CI of 1.38 to 6.54 compared with wild type. Codons 62 and 158 were in linkage disequilibrium (LD), and when compared with the C-G haplotype, other types (C-A, T-G, T-A) were observed to be associated with prostate cancer (P = 0.040) but not BPH. Codon 72 on the other hand, was not in LD with either codon 62 or 158. The homozygous variant on codon 72 was rare in this Japanese population, and the heterozygous G/T at this codon was not associated with either prostate cancer or BPH. When evaluating the risk of COMT polymorphisms with stage or grade of cancer, no associations were observed for any of the genotypes with the exception of a tendency (P = 0.096) for the variant A allele on codon 158 to be correlated with higher stages (> or = T3) of cancer. This is the first report that shows the polymorphisms of COMT to be associated with sporadic prostatic carcinogenesis. These results are important in understanding the role of COMT polymorphisms in the pathogenesis of prostate cancer.

Alleles↗

PubMed2005

Hrs, a mammalian master molecule in vesicular transport and protein sorting, suppresses the degradation of ESCRT proteins signal transducing adaptor molecule 1 and 2.

The degradation and sorting of cytoplasmic and cell-surface proteins are crucial steps in the control of cellular functions. We previously identified three mammalian Vps (vacuolar protein sorting) proteins, Hrs (hepatocyte growth factor-regulated tyrosine kinase substrate) and signal transducing adaptor molecule (STAM) 1 and -2, which are tyrosine-phosphorylated upon cytokine/growth factor stimulation. Hrs and the STAMs each contain a ubiquitin-interacting motif and through formation of a complex are involved in the vesicle transport of early endosomes. To explore the mechanism and cellular function of this complex in mammalian cells, we established an Hrs-defective fibroblastoid cell line (hrs(-/-)); embryos with this genotype died in utero. In the hrs(-/-) cells only trace amounts of STAM1 and STAM2 were detected. Introduction of wild-type Hrs or an Hrs mutant with an intact STAM binding domain (Hrs-dFYVE) fully restored STAM1 and STAM2 expression, whereas mutants with no STAM binding ability (Hrs-dC2, Hrs-dM) failed to express the STAMs. This regulated control of STAM expression by Hrs was independent of transcription. Interestingly, STAM1 degradation was mediated by proteasomes and was partially dependent on the ubiquitin-interacting motif of STAM1. Revertant Hrs expression in hrs(-/-) cells not only led to the accumulation of ubiquitinated proteins, including intracytoplasmic vesicles, but also restored STAM1 levels in early endosomes and eliminated the enlarged endosome phenotype caused by the absence of Hrs. These results suggest that Hrs is a master molecule that controls in part the degradation of STAM1 and the accumulation of ubiquitinated proteins.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Inactivation of the hMSH3 mismatch repair gene in bladder cancer.

Deficiency in the DNA mismatch repair (MMR) is frequently involved in various cancers. The hMSH3 gene is one of the human MMR genes whose role in bladder cancer is not known. We hypothesized that down-regulation of the hMSH3 gene might be involved in bladder cancer. In this study we analyzed this gene with regard to frame-shift mutation, single nucleotide polymorphism (SNP), a 9bp repeat in exon 1, loss of heterozygosity (LOH), immunohistochemistry, and methylation status in 102 bladder cancer samples. Immunohistochemistry revealed that hMSH3 expression in bladder cancer was significant decreased compared to normal epithelium (p<0.0001). An inverse correlation with pathological grade was found. The frame-shift mutation in the (A) 8 tract was lacking in bladder cancer. There was no significantly difference between bladder cancer samples and healthy controls' with regard to SNP and the 9bp repeat. In bladder cancer, presence of the codon 222 polymorphism, LOH, and the 9bp repeats in exon 1 had a correlation with either pathological stage or pathological grade. Presence of the codon 1036 polymorphism had significant correlation with pathological stage and a trend to correlation with pathological grade. After 5-aza-dC treatment, MSH3 expression was significantly enhanced in TCC and UMUC bladder cancer cells when compared to untreated cells. This is the first report suggesting that genetic and epigenetic alterations in the human MSH3 gene might play a significant role in the progression of bladder tumors.

Azacitidine↗

PubMed2004

Evaluation of a rapid antigen detection test for Neisseria gonorrhoeae in urine sediment for diagnosis of gonococcal urethritis in males.

We evaluated a rapid antigen detection method with an immunochromatographic assay for Neisseria gonorrhoeae (NOW Gonorrhea Test) by using urine samples from patients with urethritis to diagnose gonococcal infection in males. Among 58 male patients who underwent urethral swab culture, 34 cases (58.6%) were found to have N. gonorrhoeae infection. The sensitivity and specificity of the NOW Test compared with the results of standard culture were 94.1% (32/34) and 95.8% (23/24), respectively. The predictive values of positive NOW and negative NOW were 96.9% (32/33) and 92.0% (23/25), respectively. The detection limit of this assay was determined as 5 x 10(4) cfu/ml using N. gonorrhoeae suspension as an antigen. In contrast to standard cultures, gonococcal antigens in specimens were still detectable by this method up to 45 h of storage at either room temperature or 4 degrees C. Considering the rapidity and ease of this method, our results suggest that the NOW method might be a useful and reliable diagnostic screening tool for gonococcal urethritis.

Antigens, Bacterial↗

PubMed2004

Safety and efficacy of vardenafil in patients with erectile dysfunction: result of a bridging study in Japan.

AIM: Vardenafil is a selective and highly potent phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), with improved selectivity for PDE5 and demonstrated efficacy for improving sexual function in men with ED. The current study investigated the safety and efficacy of this new PDE5 inhibitor in Japanese men with ED. METHODS: This was a prospective, double blind, randomized clinical trial designed to evaluate the efficacy and safety of vardenafil. Following a 4-week treatment-free observation period, 283 eligible patients were randomized to 12 weeks treatment with vardenafil 5 mg, 10 mg, 20 mg, or placebo. Primary efficacy responses were assessed using the scores of Q3 and Q4 of the international index of erectile function (IIEF). RESULTS: All three vardenafil doses showed significantly better improvement than the placebo group in Q3 and Q4 scores of the IIEF questionnaire, either at 12 weeks or at the 'last observation carried forward' (LOCF, P < 0.0001). Q3 scores were improved to 4.06 with vardenafil 5 mg, 4.53 with vardenafil 10 mg, and 4.64 with vardenafil 20 mg, versus 3.17 with placebo. Comparable scores for Q4 were 3.47, 4.15 and 4.31 versus 2.31 for placebo. Up to 86% of patients achieved improved erections as assessed by the global assessment question (GAQ). Reported adverse event rates were 35.3%, 45.3% and 54.5% with vardenafil 5 mg, 10 mg and 20 mg, respectively, versus 21.1% in the placebo group. No serious adverse drug reactions were reported. The most common treatment-emergent adverse events were transient headache, flushing and rhinitis, which were mostly mild. CONCLUSION: Vardenafil is an effective and well-tolerated treatment for ED and provides improvement in key indices of erectile function among Japanese men with ED. The results of our trial show that up to nearly 90% of patients achieve improved erections with the administration of vardenafil.

Adult↗

PubMed2003

Men's Health Study: epidemiology of erectile dysfunction and cardiovascular disease.

The present study collected data about 6,112 Japanese male patients from 447 outpatient clinics. Of those who underwent medical examination by a general practitioner on an outpatient basis, up to 81% had some degree of erectile dysfunction (ED), ranging from mild to severe. ED was noted to be predominant among patients affected by cardiovascular disease (CVD) or diabetes mellitus (DM), and the presence of CVD increased the risk of ED. In an aging society, patients undergoing treatment for ED as part of their routine medical care are highly likely to have concomitant CVD. As shown in the present survey, clinicians need to be aware of the high incidence of ED among such patients, because ED represents a symptom originating from damage to the vascular endothelium. A total of 41% of ED patients are either willing to receive pharmacotherapy for ED or will consider treatment. Active treatment of ED with sildenafil is suitable for patients with CVD.

Adult↗

PubMed2003

[Men's health study: current status of erectile dysfunction of 6,112 ambulatory patients at general practitioners offices in Japan].

OBJECTIVES AND METHODS: The present study was performed to assess the current status of erectile dysfunction (ED) and so-called male climacteric disorders in male ambulatory patients through a self-administered questionnaire survey throughout Japan. The survey was especially focused on the relationship between ED, depression, and benign prostatic hyperplasia, the effect of ED on quality of life, and current status of ED treatment. RESULTS: The total number of completed questionnaire forms was 6,112 from 447 outpatient clinics. ED was strongly correlated with prostate disease, diabetes mellitus, and heart disease. Patients evaluated as ED by the shortened version of International Index of Erectile Function, IIEF-5, accounted for 81% of the evaluable replies. Thirty-two percent of these patients had either severe or moderate ED. Severity of ED was related to depression, dysuria, and perceived poor health condition. The proportion of ED patients who had received some ED treatments was 10%. Among ED patients, 22% of them were willing to receive pharmacotherapy for ED and the need was significantly high in patients with severer ED. CONCLUSIONS: ED is one of the symptoms frequently observed among male ambulatory patients. Physicians should be encouraged to ask their patients about their ED, in order to identify their unmet need for treatment.

Adult↗

PubMed2002