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Dive into the research topics where Masami Takeyama is active.

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Featured researches published by Masami Takeyama.


The Journal of Urology | 1988

Surgical repair of varicocele at puberty: preventive treatment for fertility improvement.

Akihiko Okuyama; Motoyuki Nakamura; M. Namiki; Masami Takeyama; Masato Utsunomiya; Fujioka H; Hiroaki Itatani; Minoru Matsuda; Kunio Matsumoto; Takao Sonoda

In 40 pubertal boys with a varicocele a comparative followup study was performed to evaluate the efficacy of surgical correction of the varicocele in this age group in regard to improvement of fertility after completion of sexual maturation. The varicocele was corrected surgically in 24 patients and it was left uncorrected in 16. Testicular atrophy was noted in all cases at the initial visit and after followup. Of the 24 corrected patients 16 had atrophy of at least 1 testis before surgical treatment, whereas only 7 demonstrated atrophy after followup. Of the 16 uncorrected patients testicular atrophy was noted in 8 at the initial visit but 12 had atrophy after followup. Semen examination of 23 patients who had completed sexual maturation demonstrated a higher quality of routine seminal parameters, for example sperm density, sperm motility and percentage of morphologically normal spermatozoa, in the corrected group than in the uncorrected group.


International Journal of Urology | 2001

Chromosomal variants among 1790 infertile men

Yoshihiro Nakamura; Masaya Kitamura; Kenji Nishimura; Minoru Koga; Kondoh N; Masami Takeyama; Kiyomi Matsumiya; Akihiko Okuyama

Abstract Background: The largest cytogenetic survey involving infertile men was undertaken to clarify whether chromosomal abnormalities, including autosomal abnormalities, affect semen qualities.


BJUI | 2009

Increased vascular endothelial growth factor expression in patients with bladder pain syndrome/interstitial cystitis: its association with pain severity and glomerulations

Hiroshi Kiuchi; Akira Tsujimura; Tetsuya Takao; Keisuke Yamamoto; Jiro Nakayama; Yasushi Miyagawa; Norio Nonomura; Masami Takeyama; Akihiko Okuyama

To determine the angiogenic profiles in the bladder of patients with bladder pain syndrome (BPS)/interstitial cystitis (IC), and to evaluate the relationship between these profiles and associated clinical features including pelvic pain and glomerulations.


International Journal of Impotence Research | 2005

Comparative study on evaluation methods for serum testosterone level for PADAM diagnosis

Akira Tsujimura; Kiyomi Matsumiya; Yasushi Miyagawa; Tetsuya Takao; Kazutoshi Fujita; Shingo Takada; Minoru Koga; A Iwasa; Masami Takeyama; Akihiko Okuyama

The International Society for the Study of the Aging Male (ISSAM) recommends that a diagnosis be based on a patients total testosterone (TT), calculated free testosterone (cFT), or calculated bioavailable testosterone (cBT) for partial androgen deficiency of the aging male (PADAM). The purpose of this study was to confirm whether hypogonadism of patients with PADAM is related to symptoms and clarify which criteria of testosterone recommended by ISSAM is suitable for Japanese patients. A total of 90 patients with PADAM symptoms were included in this study. Endocrinologic profiles were reviewed as appropriate, and PADAM symptoms were judged by means of several questionnaires. Laboratory values and symptoms were compared between patients with and without hypogonadism. Even when any criterion of testosterone was used for diagnosis of hypogonadism, AMS (total and subscales), IIEF-5, or SDS scores of PADAM symptoms did not differ significantly between patients classified as having and not having hypogonadism. No other endocrinologic variables than testosterone differed significantly between them, either. PADAM symptoms are not related to testosterone level and it is still obscure whether ISSAMs criterion can be adopted for Japanese patients with PADAM. Other pathology needs to be addressed for evaluation and diagnosis of PADAM in Japan.


The Journal of Urology | 2006

Salvage Microdissection Testicular Sperm Extraction After Failed Conventional Testicular Sperm Extraction in Patients With Nonobstructive Azoospermia

Akira Tsujimura; Yasushi Miyagawa; Tetsuya Takao; Shingo Takada; Minoru Koga; Masami Takeyama; Kiyomi Matsumiya; Fujioka H; Akihiko Okuyama

PURPOSE TESE is considered the best procedure for identifying a tubule for spermatozoa retrieval. This technique improves the SRR to around 50%. However, it has been unclear whether it is useful in patients in whom conventional TESE has failed. We compared the outcome of microdissection TESE in patients in whom conventional TESE failed to that in patients who did not undergo conventional TESE. We also evaluated relations between the outcome of salvage microdissection TESE and the characteristics of previous conventional TESE. MATERIALS AND METHODS A total of 46 patients with nonobstructive azoospermia in whom salvage microdissection TESE was performed after failed conventional TESE were included. Patient characteristics and the SRR were compared between these patients and 134 in whom conventional TESE had not been performed previously. The previous TESE procedure, testicular histology and interval between TESEs were also evaluated. RESULTS Patient characteristics did not differ significantly between the groups. The microdissection TESE SRR also did not differ significantly between the groups (45.7% vs 44.0%). The possibility of successful spermatozoa retrieval by salvage microdissection TESE remained regardless of the previous failure of any other TESE procedure and regardless of testicular histology. The salvage microdissection TESE SRR was not related to the interval between TESEs. CONCLUSIONS Because salvage microdissection TESE is effective in patients in whom conventional TESE has failed, this option should be made available to them with the understanding that extended followup after salvage microdissection TESE is necessary due to the risk of hypogonadism.


The Journal of Urology | 1982

Preoperative diagnosis of coincident renal cell carcinoma and renal angiomyolipoma in nontuberous sclerosis.

Masami Takeyama; Masaaki Arima; Shiro Sagawa; Takao Sonoda

Abstract We describe a case of coincidental renal cell carcinoma and renal angiomyolipoma occurring in the same kidney without stigmas of tuberous sclerosis. The correct diagnosis was made preoperatively by a combination of angiography, ultrasonography and computerized tomography.


Archives of Andrology | 1987

Temperature Sensitivity of Human Spermatogonia and Spermatocytes in Vitro

Motoyuki Nakamura; M. Namiki; Akihiko Okuyama; T. Matsui; Y. Doi; Masami Takeyama; Fujioka H; Yoshitake Nishimune; Keishi Matsumoto; Takao Sonoda

To study the effect of temperature on human spermatogenesis, both the number and DNA synthesis of germ cells were investigated in tissue fragments of human testes cultured for 22 h at 31 degrees C and 37 degrees C. The number of differentiated germ cells such as spermatids and spermatozoa cultured at 37 degrees C was significantly smaller than that cultured at 31 degrees C. The number of spermatogonia and resting primary spermatocytes was not significantly different between these two temperatures, but the functional ability of DNA synthesis in these cells was significantly lower at 37 degrees C than at 31 degrees C. It seems that in normal body temperature (37 degrees C) differentiated germ cells such as spermatids and spermatozoa are fragile and the DNA synthesis of spermatogonia and resting primary spermatocytes is retarded.


Archives of Andrology | 1988

Optimal Temperature for Synthesis of DNA, RNA, and Protein by Human Testis in Vitro

Motoyuki Nakamura; M. Namiki; Akihiko Okuyama; E. Koh; Kondoh N; Masami Takeyama; Fujioka H; Yoshitake Nishimune; Keishi Matsumoto; Minoru Matsuda

To determine the optimal temperature for DNA, RNA, and protein syntheses in the human testis, the levels of incorporation of 3H-thymidine, 14C-uridine, and 14C-leucine into testicular tissue were studied at 28 degrees C, 31 degrees C, 34 degrees C, and 37 degrees C in vitro. The results suggest that the DNA synthesis is at a maximum at 31 degrees C and shows delicate temperature sensitivity, whereas the RNA and protein syntheses are at a maximum at 34 degrees C or 37 degrees C and are temperature-dependent. It is concluded that the temperature sensitivity of DNA synthesis may be one of the primary causes of delicate thermal inhibition of human spermatogenesis.


The Journal of Urology | 1998

SUSCEPTIBILITY TO IDIOPATHIC AZOOSPERMIA IN JAPANESE MEN IS LINKED TO HLA CLASS I ANTIGEN

Hidenobu Miura; Akira Tsujimura; Kenji Nishimura; Masaya Kitamura; Kondoh N; Masami Takeyama; Fujioka H; Masaharu Sada; Takayuki Tsuji; Kiyomi Matsumiya; Shiro Takahara; Akihiko Okuyama

PURPOSE Approximately 15 to 20% of infertile men have azoospermia. In the Y chromosome a deletion, termed the azoospermic factor, has been found in some cases of idiopathic azoospermia. We investigate the relationship of factors in autosomal chromosomes (HLA class I antigens) to spermatogenesis failure in idiopathic azoospermia. MATERIALS AND METHODS We evaluated 65 infertile Japanese men with idiopathic azoospermia. The frequency of the HLA allele reported in 1,216 healthy Japanese men was used as a control. HLA class I typing was performed by the National Institutes of Health standard serological method or polymerase chain reaction-sequence specific primer analysis. Allele frequencies were calculated. We determined statistical significance in the frequency of each allele in patients and controls using the chi-square test. The relationship of HLA antigens to idiopathic azoospermia was expressed as relative risk. RESULTS In Japanese men with idiopathic azoospermia the frequency of HLA-A33, B13 and B44 was significantly increased compared with controls. The relative risk of HLA-B44 was 8.4, an extremely high value compared with that of other diseases and HLA antigens. CONCLUSIONS We suggest that HLA class I antigens are important genetic markers that represent a risk factor for idiopathic azoospermia.


Archives of Andrology | 1988

Induction of renin-angiotensin system in human testis in vivo.

Akihiko Okuyama; Norio Nonomura; E. Koh; Kondoh N; Masami Takeyama; Motoyuki Nakamura; M. Namiki; Fujioka H; Kunio Matsumoto; Minoru Matsuda

To better understand the local renin-angiotensin system in Leydig cells of the human testis, the plasma renin activity (PRA) and plasma concentration of angiotensin II (PAII) in the left internal spermatic vein (ISV) and cubital vein (CV) were measured at the time of surgical repair of varicocele in 27 patients. Fourteen of the patients were given a single i.m. injection of hCG (10,000 IU/m2) 4 days before the operation, whereas the remaining 13 were not treated. Although the mean PRA or PAII levels in the CV in the treated and nontreated groups were similar, both levels in the ISV in the treated group were significantly higher than in the nontreated group (p less than 0.05). For PAII levels in the treated group, nine of 11 patients with an increased PRA level showed significantly higher levels than the normal peripheral PAII value. The serum testosterone levels in the same ISV were also much higher in the treated group than in the nontreated group (p less than 0.001). These results suggested the possibility that sex steroids might influence the renin-angiotensin system in Leydig cells.

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