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Dive into the research topics where Kei Matsushita is active.

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Featured researches published by Kei Matsushita.


International Journal of Urology | 2012

Effect of surgical repair on testosterone production in infertile men with varicocele: a meta-analysis.

Fuping Li; Huanxun Yue; Kohei Yamaguchi; Keisuke Okada; Kei Matsushita; Makoto Ando; Koji Chiba; Masato Fujisawa

Objectives:  To determine the effect of surgical varicocele repair in improving testicular Leydig cell function as shown by increased testosterone production.


Systems Biology in Reproductive Medicine | 2012

Significant improvement of sperm DNA quality after microsurgical repair of varicocele

Fuping Li; Kohei Yamaguchi; Keisuke Okada; Kei Matsushita; Makoto Ando; Koji Chiba; Huanxun Yue; Masato Fujisawa

Varicocele is currently the most common irregularity identified in males that is associated with impaired spermatogenesis. It primarily presents in the form of decreased sperm count and motility, abnormal morphology, and significantly increased sperm DNA fragmentation. Several studies have shown that surgical repair improves semen parameters and increases the odds of spontaneous pregnancy. However the exact effect of surgical repair treatment remains controversial. Therefore, the aim of our study was to evaluate the effectiveness of microsurgical repair by comparing common semen parameters and sperm DNA fragmentation index (DFI). We evaluated infertile men (n = 19) who underwent microsurgical subinguinal varicocelectomy for treatment of clinical varicocele before and 3 months after surgery. Normozoospermic men (n = 19) were considered as the normal control group. Semen parameters improved significantly after surgery when compared with that before surgery, but still significant differences with the normal control group were observed. In comparison, sperm DNA integrity improved significantly after surgery (percentage DFI decreased from 28.4 ± 15.6% before surgery to 22.4 ± 12.9%, at 3 months post surgery) to similar levels as the normal control group. These results suggest that microsurgical repair may be considered as a treatment option in infertile men with palpable varicocele.


Biology of Reproduction | 2013

Efficient Transfection of DNA into Primarily Cultured Rat Sertoli Cells by Electroporation

Fuping Li; Kohei Yamaguchi; Keisuke Okada; Kei Matsushita; Noritoshi Enatsu; Koji Chiba; Huanxun Yue; Masato Fujisawa

ABSTRACT The expression of exogenous DNA in Sertoli cells is essential for studying its functional genomics, pathway analysis, and medical applications. Electroporation is a valuable tool for nucleic acid delivery, even in primarily cultured cells, which are considered difficult to transfect. In this study, we developed an optimized protocol for electroporation-based transfection of Sertoli cells and compared its efficiency with conventional lipofection. Sertoli cells were transfected with pCMV-GFP plasmid by square-wave electroporation under different conditions. After transfection of plasmid into Sertoli cells, enhanced green fluorescent protein (EGFP) expression could be easily detected by fluorescent microscopy, and cell survival was evaluated by dye exclusion assay using Trypan blue. In terms of both cell survival and the percentage expressing EGFP, 250 V was determined to produce the greatest number of transiently transfected cells. Keeping the voltage constant (250 V), relatively high cell survival (76.5% ± 3.4%) and transfection efficiency (30.6% ± 5.6%) were observed with a pulse length of 20 μm. The number of pulses significantly affected cell survival and EGFP expression (P < 0.001). Cell survival clearly decreased following one to three pulses, from 83.9% ± 6.1% to 3.2% ± 1.1%, with EGFP expression increasing from 41.8% ± 9.4% to 66.7% ± 5.2%. The yield of positive cells increased with increasing concentration of plasmid DNA (range, 10–50 μg/ml), from 14.0% ± 2.8% to 35.0% ± 6.3%, but cell viability steadily decreased following 20 μg/ml plasmid DNA, from 73.1% ± 4.9% to 57.0% ± 6.6%. Compared with two popular cationic lipid transfection methods, the transfection efficiency of electroporation (21.5% ± 5.7%) was significantly higher than those of Lipofectamine 2000 (2.9% ± 1.0%) and Effectene (1.9% ± 0.8%) in this experiment (P < 0.001). We describe the process of optimizing electroporation conditions, and the successful electroporation of plasmid DNA into primarily cultured Sertoli cells. Our results indicate that the method of electroporation is more suitable than other approaches for the transfection of Sertoli cells.


Andrologia | 2016

Clusterin produced by Sertoli cells inhibits heat stress‐induced apoptosis in the rat testis

Kei Matsushita; Hideaki Miyake; Koji Chiba; Masato Fujisawa

The objectives of this study were to determine whether the inhibition of clusterin expression in rat Sertoli cells enhances heat stress‐induced apoptosis. The scrotums of rats were immersed in a water bath of 43 °C for 15 min. Testicular weight and germ cell number markedly decreased after the heat treatment in a time‐dependent manner. In contrast, clusterin mRNA and protein expression levels were significantly up‐regulated and peaked on day 21. The apoptotic index was markedly increased 1 day after the heat treatment. We then purified Sertoli cells from the rat testes, and an expression vector containing siRNA targeting the clusterin gene was transiently transfected into Sertoli cells. Following exposure to heat stress at 41 °C for 12 h, clusterin mRNA was markedly up‐regulated after transfection with the control vector; however, the transfection of siRNA targeting the clusterin resulted in >70% reduction in the expression of clusterin mRNA. Furthermore, the apoptotic index in these Sertoli cells was significantly higher after the treatment with siRNA targeting the clusterin than control, and the most prominent difference was observed within 24 h after the heat treatment. These results suggest that an increase in the secretion of clusterin by Sertoli cells protects the testes from heat stress‐induced injury.


Urology | 2015

Assessment of Time-dependent Changes in Semen Parameters in Infertile Men After Microsurgical Varicocelectomy

Teruo Fukuda; Hideaki Miyake; Noritoshi Enatsu; Kei Matsushita; Masato Fujisawa

OBJECTIVE To characterize the changes in seminogram findings in infertile men after varicocelectomy. METHODS This study included 71 consecutive infertile men who underwent microsurgical low ligation varicocelectomy and received 3 semen analyses, 1 before microsurgical varicocelectomy and again at 3 and 12 months after. Total motile sperm count (TMSC) was calculated using the following formula: [volume (mL) × concentration (millions/mL) × motility (%)]. RESULTS Despite the lack of significant changes in the proportion of sperm with abnormal morphology, sperm concentration, motility, and TMSC in the 71 patients were significantly higher at 3 and 12 months after varicocelectomy than before surgery. However, no further improvement in these parameters at 12 months after varicocelectomy was noted compared with those at 3 months. Furthermore, when the included men were divided into 3 groups according to preoperative TMSC as <3 million, 3-9 million, and >9 million, TMSCs at 3 months after varicocelectomy in all 3 groups were significantly higher than those before varicocelectomy; however, TMSCs at 12 months after surgery in all groups were similar to those at 3 months. CONCLUSION The level of improvement in semen parameters at 3 months after varicocelectomy may be stable at 12 months after surgery, irrespective of baseline values of TMSC. Therefore, varicocelectomy could be offered as a therapeutic option for infertile men, even for couples with an older woman, because its efficacy is evaluable at 3 months after surgery, and assisted reproductive technology could be immediately applied to ineffective cases.


Jsls-journal of The Society of Laparoendoscopic Surgeons | 2011

Inflammatory pseudotumor of the retroperitoneum removed via a retroperitoneoscopic approach.

Hideo Soga; Akihisa Yao; Kei Matsushita; Hiroyoshi Shimogaki; Gaku Kawabata

A retroperitoneal laparoscopic approach was found to be useful for treating primary retroperitoneal tumors located below the level of the renal vessels.


American Journal of Men's Health | 2018

Improved Lower Urinary Tract Symptoms Associated With Testosterone Replacement Therapy in Japanese Men With Late-Onset Hypogonadism

Keisuke Okada; Hideaki Miyake; Takaki Ishida; Kenta Sumii; Noritoshi Enatsu; Koji Chiba; Kei Matsushita; Masato Fujisawa

This study aimed to investigate the effects of testosterone replacement therapy (TRT) on lower urinary tract symptoms (LUTS) in men with late-onset hypogonadism (LOH) and to identify parameters predicting the efficacy of TRT in improving LUTS. This study included 60 consecutive Japanese men who were diagnosed with LOH and subsequently received TRT between January 2009 and December 2014. In this series, 250 mg of testosterone was injected intramuscularly every 3 or 4 weeks in all patients. The following parameters were retrospectively reviewed: body mass index (BMI), Aging Male Symptom (AMS) score, International Prostate Symptom Score (IPSS), International Index of Erectile Function–5 (IIEF-5) score, residual urine volume, prostate volume, serum levels of the prostate-specific antigen (PSA), and total- and free-testosterone levels before and 6 months after TRT. No significant differences were observed in BMI, residual urine volume, or prostate volume between surveys before and after TRT. The AMS score, IPSS, and IIEF-5 score were significantly improved and significant increases were noted in the serum levels of PSA and total- and free-testosterone levels after TRT. An analysis of IPSS subscores documented the significant improvement in storage symptom scores, but not in voiding symptom scores after TRT. Multivariate analyses of parameters assessed in this study identified the pretreatment AMS score, posttreatment IIEF-5 score, and prostate volume as independent predictors of improvements in IPSS following TRT. This study revealed that TRT appeared to have considerable therapeutic effects on LUTS, particularly on storage symptoms, in men with LOH.


Cogent Medicine | 2016

Erectile function and its impact on quality of life in Japanese men on hemodialysis

Kenta Sumii; Hideaki Miyake; Kunihiko Yoshiya; Noritoshi Enatsu; Kei Matsushita; Shoji Hara; Masato Fujisawa

Abstract The objective of this study was to characterize the erectile function and its impact on health-related quality of life (HRQOL) in Japanese men on hemodialysis. This study included 65 consecutive Japanese men <80 years on hemodialysis. Erectile function and HRQOL were evaluated using the Sexual Health Inventory for Men (SHIM) and the Short-Form 8 (SF-8) survey, respectively. These 65 men were classified into 54 with SHIM ≤11; relatively severe erectile dysfunction (ED) (group A) and 11 with SHIM ≥12; relatively mild ED (group B). There were significant differences in age, marital status, ankle-brachial index (ABI), and serum levels of free testosterone and prolactin between groups A and B. Of several factors examined, age, marital status and ABI were significantly associated with the severity of ED on univariate analysis, and of these 3 factors, only age was significantly associated with severity of ED on multivariate analysis. SF-8 survey revealed that all scale scores in group A were inferior to those in group B. Comparatively severe ED appeared to be frequently observed in Japanese men on hemodialysis, and this trend was marked in elderly men. Furthermore, the severity of ED had a negative impact on the wide range of HRQOL in these men.


Andrologia | 2016

Prospective assessment of health-related quality of life in men with late-onset hypogonadism who received testosterone replacement therapy

Kenta Sumii; Hideaki Miyake; Noritoshi Enatsu; Kei Matsushita; Masato Fujisawa

The objective of this study was to characterise the status of health‐related quality of life (HRQOL) in Japanese men with late‐onset hypogonadism (LOH) treated with testosterone replacement therapy (TRT). HRQOL in 69 consecutive Japanese men with LOH undergoing TRT for at least 6 months was prospectively evaluated before and 6 months after the initiation of TRT using the Medical Outcomes Study 8‐Item Short‐Form Health Survey (SF‐8). All eight‐scale scores except for bodily pain (BP) in the 69 patients at 6 months after the introduction of TRT significantly improved compared with those before TRT; however, all scale scores except for BP in the 69 patients were significantly inferior to those in age‐matched Japanese controls irrespective of the timing of SF‐8. Multivariate analyses of several parameters revealed that both age and Aging Male Symptom (AMS) score had an independent impact on mental health (MH), despite the lack of an independent association between any score and the remaining factors examined. TRT appeared to significantly improve the status of HRQOL in men with LOH; however, even after the introduction of TRT, HRQOL associated with MH remained significantly impaired in elderly men and/or those with a high AMS score.


Andrologia | 2014

Achieved pregnancy with the delivery of a healthy child by TESE-ICSI 7 years after bilateral adult orchidopexy: a case report.

Kei Matsushita; Kohei Yamaguchi; Fuping Li; Keisuke Okada; Makoto Ando; Koji Chiba; M. Koshida; Hideaki Miyake; Masato Fujisawa

We report pregnancy with the delivery of a healthy child by TESE‐ICSI 7 years after bilateral adult orchidopexy. A 29‐year‐old patient presented with infertility and previous bilateral cryptorchidism, but no surgical treatment had ever been performed. His partner had been assessed by a gynaecologist, and no contributing female factors were detected. Orchidopexy and conventional testicular sperm extraction (TESE) were performed and microdissection TESE 10 months after orchidopexy. The second microdissection TESE with intracytoplasmic sperm injection (ICSI) was performed 7 years after orchidopexy. The couple achieved pregnancy with the delivery of a healthy child by TESE‐ICSI. It is concluded that bilateral orchidopexy in adulthood progresses spermatogenesis gradually, and microdissection TESE may succeed after a certain period of time following treatment.

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