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Dive into the research topics where Hisakazu Kiyohara is active.

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Featured researches published by Hisakazu Kiyohara.


The Journal of Urology | 1989

Surgical Management of Undescended Testis: Retrospective Study of Potential Fertility in 274 Cases

Akihiko Okuyama; Norio Nonomura; Motoyuki Nakamura; M. Namiķi; Fujioka H; Hisakazu Kiyohara; Kunio Matsumoto; Takao Sonoda

To determine the fertility potential of men with an undescended testis a retrospective study was performed on 274 patients by evaluating sperm density and sperm motility, as well as histopathological findings of the seminiferous tubules. The patients, who had been treated surgically when they were 2 to 5 or 9 to 12 years old and who were examined when they were 18 to 39 years old, were divided into 4 groups: group 1 (61 patients) underwent bilateral orchiopexy, group 2 (149) underwent unilateral orchiopexy, group 3 (26) underwent unilateral orchiectomy and group 4 (38) received no surgical treatment for a unilateral undescended testis. Significant differences in the sperm density and motility were detected between group 1 (normal range 0 to 7 per cent) and group 2 or 3 (normal range 72 to 79 per cent), and between group 2 or 3 and group 4 (normal range 42 to 58 per cent). Histopathological differences were significant between group 1 or 2 (Johnsens score count 6.06 to 6.11) and group 4 (4.72) for the affected side, and between group 2 or 3 (9.09 to 9.20) and group 4 (8.60) for the unaffected side. The results suggest that surgical treatment may not significantly ameliorate the fertility potential of patients with bilateral undescended testes. On the other hand, in patients with unilateral undescended testis an operation not later than at early puberty is advisable to maintain the spermatogenic function in the unaffected testis. It is suggested that some unknown factors relating to the highly impaired unilateral undescended testis may in some way inhibit function of the contralateral unaffected testis.


The Journal of Urology | 1993

Significance of Subclinical Varicocele Detected by Scrotal Sonography in Male Infertility: A Preliminary Report

Kondoh N; Norio Meguro; Kiyomi Matsumiya; M. Namiki; Hisakazu Kiyohara; Akihiko Okuyama

To assess the clinical significance of subclinical right varicocele, we used scrotal sonography for a prospective study of 68 infertile patients with a clinical left varicocele. A significant difference was found in the improvement in postoperative semen characteristics between sonographically diagnosed bilateral and unilateral groups. We conclude that a subclinical right varicocele is also detrimental for spermatogenesis in patients with a clinical left varicocele.


The Journal of Steroid Biochemistry and Molecular Biology | 1991

EVIDENCE FOR THE PRESENCE OF ANDROGEN RECEPTORS IN HUMAN LEYDIG CELLS

M. Namiki; Kiyoshi Yokokawa; Akihiko Okuyama; E. Koh; Hisakazu Kiyohara; Makoto Nakao; Saburo Sakoda; Keishi Matsumoto; Takao Sonoda

Localization of androgen receptors (ARs) in the human testis Leydig cells was examined with an AR assay and Northern blot analysis. Leydig cells, highly purified on a Percoll gradient, were used for the experiments. AR concentration in the total cell extract containing both the cytosol and nuclear fractions in Leydig cells was measured using [3H]methyltrienolone. ARs in Leydig cells showed a high affinity for [3H]methyltrienolone and the Kd and Bmax of the receptors were 1.24 nM and 11.7 fmol/mg protein, respectively. Northern blot analysis, using a 32P-labeled full-length human AR complementary DNA (cDNA) detected a 9.5-kb hybridizing band in the total RNA extracted from Leydig cells. These data can be interpreted as evidence of the existence of ARs in human Leydig cells.


The Journal of Urology | 1987

Immunosuppressive acidic protein in patients with testicular cancer.

Tsuneharu Miki; Shigeru Saiki; Toshiaki Kinouchi; Masao Kuroda; Hisakazu Kiyohara; Michiyuki Usami; Masumi Sawada; Toshihiko Kotake

Serum immunosuppressive acidic protein was compared to lactic dehydrogenase as a marker for testicular cancer in 54 patients with testicular cancer, 62 with benign urological diseases and 203 healthy controls. The mean value of serum immunosuppressive acidic protein in patients with testicular cancer (598 +/- 293 micrograms. per ml.) was statistically higher than that in patients with benign disease (429 +/- 163 micrograms. per ml.) and healthy controls (368 +/- 73 micrograms. per ml.). There were statistically significant differences in serum immunosuppressive acidic protein levels between controls and patients with stage 2 (p less than 0.0001) or stage 3 (p less than 0.001) testicular cancer, and between those with stage 1 and stage 2 (p less than 0.0001) or stage 3 (p less than 0.001) disease, respectively. The usefulness of immunosuppressive acidic protein as a marker for testicular cancer also was compared to that of lactic dehydrogenase. Immunosuppressive acidic protein and lactic dehydrogenase levels were elevated almost equally in patients with stage 2 or 3 disease (range 71 to 92 per cent). However, immunosuppressive acidic protein levels were elevated in only 3 of 25 patients with stage 1 cancer (12 per cent), compared to 11 of 25 (44 per cent) with elevated lactic dehydrogenase levels. Immunosuppressive acidic protein was correlated better with tumor stage. In conclusion, serum immunosuppressive acidic protein determinations may be useful in patients with testicular cancer for staging, monitoring treatment results and predicting recurrence.


Archives of Andrology | 1991

Mixed Gonadal Dysgenesis: Case Reports and a Review of 65 Japanese Cases

Norio Nonomura; Motoyuki Nakamura; M. Namiki; Hisakazu Kiyohara; Mizutani S; Akihiko Okuyama; Takao Sonoda

Four cases of mixed gonadal dysgenesis encountered in our institute are described here, and 65 cases of mixed gonadal dysgenesis in the Japanese literature, including our cases, are reviewed. Of the four cases reported here, three had a chromosomal structure of 46,XY and one of 45,XO/46,XYq-. A chromosomal structure of 45,XO/46,XY accounts for 35% of all cases of mixed gonadal dysgenesis reported in the Japanese literature, 46,XY for 31%, and other types for 24%. Two of our cases (50%) also had a gonadal tumor. The overall incidence of gonadal tumor occurring after onset of puberty and reported in the Japanese literature is 17%.


The Journal of Urology | 1977

Pheochromocytoma with prominent calcification and associated pancreatic islet cell tumor.

Yoshinori Mori; Hisakazu Kiyohara; Tsuneharu Miki; Toshihiko Kotake

A case of bilateral pheochromocytoma with an associated pancreatic islet cell tumor is reported. Prominent calcification was noted in the left adrenal tumor.


International Journal of Urology | 1994

New indication of testis biopsy for azoospermia: a clinical study in Japanese patients.

Kiyomi Matsumiya; M. Namiki; Kondoh N; Hisakazu Kiyohara; Akihiko Okuyama

Because of the progress made with assisted reproductive techniques, we decided to clarify the indication for testis biopsy in Japanese azoospermic patients. A total of 88 azoospermic patients were recruited with testis histologies obtained by bilateral biopsy. Testicular histology was evaluated using Johnsens score count. Patients with at least 1 testis containing sperm were assigned to the active spermatogenesis group. Patients whose testes had no sperm were assigned to the hypospermatogenesis group. Differences in terms of the clinical data between the 2 groups were analyzed. Clinical data consisted of past history, physical examination and hormone concentrations. The unpaired t test was generally used to examine the statistical significance of any differences between the 2 groups. 1) There were significant differences between the 2 groups in the levels of serum testosterone and luteinizing hormone. 2) There were markedly significant differences between the 2 groups in terms of testis volume and the concentration of serum follicle‐stimulating hormone (FSH). 3) The smallest testis volume and the highest serum FSH value in the active spermatogenesis group were 7 ml and 32.7 mlU/ml (normal range 2.9‐8.2), respectively. In conclusion, although the presence or absence of active spermatogenesis can be accurately predicted by measuring the testis volume and serum FSH, testis biopsy should be carried out in patients with a testis volume greater than 7 ml or a serum FSH less than 4 times normal when the use of assisted reproductive techniques are planned.


Archives of Andrology | 1989

Testicular FSH and hCG Receptors in Sertoli-Cell-Only Syndrome

Akihiko Okuyama; Norio Nonomura; E. Koh; Kondoh N; Motoyuki Nakamura; Mikio Namiki; T. Yoshida; Fujioka H; Hisakazu Kiyohara; Kunio Matsumoto; Takao Sonoda

Testicular FSH and hCG receptors were measured in patients with Sertoli-cell-only syndrome (SCOS), and the value of Bmax for each hormone was compared with the value in subjects with normal testes. FSH receptor was detectable in only four of 10 patients, and the mean value of Bmax in four of the 10 patients was clearly lower than that in normal testes (p less than 0.005). On the other hand, hCG receptors were detected in all of six tested patients, and the mean value of Bmax was lower, but not remarkably so, than that in the normal testes. The function of Sertoli cells was remarkably impaired in most men with SCOS, whereas the function of Leydig cells was relatively preserved.


The Journal of Urology | 1996

Infrared Thermometry for Rapid, Noninvasive Detection of Reflux of Spermatic Vein in Varicocele

Takada T; Masaya Kitamura; Kiyomi Matsumiya; Tsuneharu Miki; Hisakazu Kiyohara; M. Namiki; Akihiko Okuyama

PURPOSE We evaluated infrared thermometry for measurement of reflux of blood via the internal spermatic vein. MATERIALS AND METHODS The change in scrotal temperature in patients with varicoceles and controls with different positions was measured with an infrared thermometer. RESULTS Scrotal neck temperature in the patients increased during Valsalvas maneuver with upright position (mean plus or minus standard deviation 34.62 +/- 1.20 to 36.05 +/- 1.42C), while no statistically significant increase occurred in the controls (32.91 +/- 0.92 to 33.42 +/- 1.15C). Two weeks after high ligation of the internal spermatic vein the scrotal temperature in the patients decreased to the same level (0.59 +/- 0.84C) as in the controls. Using this method 2 subclinical varicoceles were also found on the right side in patients with a left varicocele. CONCLUSIONS Infrared thermometry is noninvasive, rapid and simple for documenting varicoceles, including subclinical disease.


The Journal of Steroid Biochemistry and Molecular Biology | 1991

Extraadrenal expression of steroid 21-hydroxylase and 11β-hydroxylase by a benign testicular leydig cell tumor

Mikio Namiki; E. Koh; Norio Meguro; Kondoh N; Hisakazu Kiyohara; Akihiko Okuyama; Saburo Sakoda; Keishi Matsumoto; Takao Sonoda

We present an unusual case with bilateral testicular Leydig cell tumors displaying extraadrenal expression of steroid 21-hydroxylase and 11 beta-hydroxylase. Histological examination of a 38-yr-old man infertile due to azoospermia showed him to have bilateral testicular Leydig cell tumors. The in vitro steroidogenic potential of the tumors and their adjacent testicular tissue was evaluated using organ culture. Tumor tissue was found to secrete deoxycorticosterone (DOC), corticosterone (B) and cortisol, which are not produced in normal adult testis, into the medium, while testicular tissue adjacent to the tumors secreted a small amount of DOC and B. Northern blot analysis with cytochrome P-450C21 complementary DNA (cDNA) and P-45011 beta cDNA as probes revealed that the tumor contained a considerable amount of mRNA for P-450C21 and P-45011 beta, while the MRNAs were not detected in the testicular tissues adjacent to the tumors. It is suggested that the high local levels of estrogen and/or progesterone within the Leydig cell tumors and their adjacent testicular tissues induced extraadrenal expression of steroid 21-hydroxylase and 11 beta-hydroxylase by the tumors and their adjacent testicular tissues.

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Tsuneharu Miki

Kyoto Prefectural University of Medicine

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