Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Kenkichi Koiso is active.

Publication


Featured researches published by Kenkichi Koiso.


The Journal of Urology | 1987

Establishment of a New Prostatic Carcinoma Cell Line (TSU-PR1)

Tatsuo Iizumi; Tsunetada Yazaki; Shori Kanoh; Ikuko Kondo; Kenkichi Koiso

A new epithelial cell line, TSU-Pr1, from a human prostatic adenocarcinoma metastatic to lymph node has been established in long term tissue culture. The cultured cells show loss of contact inhibition, rapid growth in vitro and growth in athymic nude mice. Karyotypic analysis demonstrated an aneuploid karyotype with a modal chromosome number of 80 including a Y-chromosome and at least 10 marker chromosomes. The cells produced only a small amount of prostatic acid phosphatase, and heterotransplanted tumors did not have nuclear androgen receptors.


European Urology | 1997

Clinical evaluation of nuclear matrix protein 22 (NMP22) in urine as a novel marker for urothelial cancer.

Miyanaga N; Hideyuki Akaza; Ishikawa S; Mikinobu Ohtani; Noguchi R; Koji Kawai; Kenkichi Koiso; Kobayashi M; Koyama A; Takahashi T

OBJECTIVES This study was undertaken to determine the clinical usefulness of nuclear matrix protein 22 (NMP22) as a novel urine marker for urothelial cancer, particularly, to substitute for voided-urine cytology. METHODS NMP22 values were determined for 280 patients and 20 healthy volunteers by NMP22 Test Kit based on an enzyme-linked immunosorbent assay. RESULTS When the cut-off value was set at 10 U/ml, the positive rate of urinary NMP22 for urothelial cancer was 80.9% (38/47), whereas that for posttreatment cases and benign diseases was 35.7% (74/207). When urinary NMP22 and voided-urine cytology were compared, the test for urinary NMP22 showed higher sensitivity than cytology in patients with urothelial cancer. When urinary NMP22 values were determined pre- and postoperatively in patients with urothelial cancer, the postoperative value decreased in all patients, and were below the cut-off value in all except one patient. CONCLUSIONS Urinary NMP22 is a useful diagnostic marker as a substitute for voided-urine cytology for the surveillance of urothelial cancer.


Cancer | 1995

Bacillus calmette—Guérin treatment of existing papillary bladder cancer and carcinoma in situ of the bladder. Four-year results

Hideyuki Akaza; Shiro Hinotsu; Aso Y; Kakizoe T; Kenkichi Koiso

Background. Intravesical instillation therapy of Bacillus Calmette‐Guérin (BCG) has become a standard treatment for carcinoma in situ (CIS) of the urinary bladder. However, there have been few reports concerning the direct effect of BCG on existing tumors classified as Ta or T1. In the first stage of this clinical study, 157 patients were treated with BCG intravesical instillation (Tokyo 172 strain [BCG Co. Ltd., Tokyo, Japan]; 80 mg weekly for eight times) by our Study Group. The efficacy on existing tumors was a complete response (CR) rate of 84.4% and 66.4% and a partial response (PR) of 6.3% and 20.8% for 32 cases of CIS and 125 cases of Ta or T1 tumors, respectively.


Fertility and Sterility | 1986

A comparative study of seminal trace elements in fertile and infertile men

Tomokazu Umeyama; Hiromichi Ishikawa; Hitoshi Takeshima; Shinichi Yoshii; Kenkichi Koiso

Fourteen kinds of trace elements were analyzed in the semen of 22 fertile men and 69 infertile men by means of inductively coupled plasma optical emission spectroscopy. Ca had the highest concentration, and the second and third highest concentrations were Zn and Mg, respectively. The concentrations of Ca, Cr, Mg, Pb, Sr, and Zn were almost the same between fertile and infertile men. Ni had a lower concentration in infertile than in fertile men. Many trace elements, such as Al, Cd, Cu, Mg, Mn, Mo, Sn, and Zn, had significantly higher concentrations in infertile men with normozoospermia than in fertile men. There was a significantly positive correlation between Zn and Mg levels in fertile and infertile men.


Cancer | 1987

Clinical evaluation of urothelial tumors of the renal pelvis and ureter based on a new classification system

Hideyuki Akaza; Kenkichi Koiso; Tadao Niijima

Clinical evaluation of 460 cases of urothelial tumors of the renal pelvis and ureter was performed using a new clinical classification system, since no systemic clinical classification such as the TNM system for bladder tumors has been available to date. ABC, and TS and TE categories were newly adopted. The former distinguishes tumor multicentricity, and the latter indicates the clinical tumor stage. Tumors arising in one organ and homolaterally are categorized as A, while those in both organs (ureter and renal pelvis) and/or in the bladder are B, and bilateral tumors are C. TS represents the tumors of pT1 and pT2, and TE represents pT3, and pT4. Tumors belonging to pB showed a poorer prognosis than pA tumors. The TS and TE staging system clearly reflected the histopathologic stage, and produced significant differences in relative survival rates. Regarding various prognostic factors, our series gave the same results as reported by other investigators. However, it should be stressed that female patients showed a poorer prognosis than male patients.


European Urology | 1997

Promoting effects and mechanisms of action of androgen in bladder carcinogenesis in male rats.

Seiki Imada; Hideyuki Akaza; Yoshihiro Ami; Kenkichi Koiso; Yukitaka Ideyama; Toichi Takenaka

OBJECTIVE It has been reported that blocking of testosterone production inhibits bladder carcinogenesis in various animal models. We investigated how testosterone acts on rat bladder carcinogenesis using an antiandrogen, flutamide, and a 5 alpha-reductase inhibitor, finasteride. METHODS Experiment 1: we administered 0.05% BBN [N-butyl-N-(4-hydroxybutyl)nitrosamine] orally to 117 Wistar rats for 10 weeks, divided them into seven groups-control, surgical castration, finasteride (2 mg/kg), luteinizing hormone releasing hormone (LH-RH) agonist (1 mg/kg) flutamide (50 mg/kg), LH-RH agonist plus finasteride, and LH-RH agonist plus flutamide-, and then cystectomized them to investigate the incidence of bladder cancer on week 21; experiment 2: we administered 0.05% BBN to 154 Wistar rats for 7 weeks, divided them into seven groups-control, finasteride 2, 4, and 8 mg/kg, and flutamide 50, 100, and 200 mg/kg-, and then we cystectomized them to investigate the dose-dependent influence on bladder carcinogenesis of these drugs on week 20, and experiment 3: we investigated the presence of androgen receptors in rat and mouse normal bladder mucosa using a monoclonal antibody. RESULTS AND CONCLUSIONS Experiment 1: Surgical castration and LH-RH agonist treatment significantly reduced the occurrence of carcinomas. There was no significant additive effect of coadministered finasteride or flutamide with LH-RH agonist. Finasteride or flutamide monotherapy showed no statistically significant effects on the results of experiment 1 at the doses used. Experiment 2: Flutamide showed a dose-dependent effect on reducing the number of rats with bladder cancer, and at a dosis of 200 mg/kg twice a week, the difference was statistically significant when compared with the control group, whereas finasteride had no statistically significant suppressing effect at any dose. Experiment 3: Mouse and rat bladder urothelium expressed the androgen receptor. Our results indicate that testosterone itself might have a more potent action on bladder carcinogenesis rather than its converting form, 5 alpha-dihydrotestosterone.


Cancer Chemotherapy and Pharmacology | 1983

Randomized clinical trial on chemoprophylaxis of recurrence in cases of superficial bladder cancer.

Tadao Niijima; Kenkichi Koiso; Hideyuki Akaza

SummarySeveral postoperative adjuvant therapeutic modalities have been adopted in attempts to reduce the recurrence rate of superficial bladder cancer. However, no definite conclusions on the effectiveness of intravesical chemoprophylaxis have been reached.A randomized clinical study on intravesical chemoprophylaxis was conducted by the Japanese Urological Cancer Research Group for Adriamycin to compare the recurrence rates among 575 patients with superficial transitional cell carcinoma of the urinary bladder. Group A received 30 mg/30 ml Adriamycin; group B received 20 mg/40 ml Adriamycin; group C received 20 mg/40 ml mitomycin C, and group D, no treatment (for control). Instillation was performed twice a week for 4 weeks after surgery. The postoperative observation period was 18 months. The overall recurrence rate in group D was 61.5%, which was statistically higher than in the other groups. The Adriamycin and Mitomycin C groups showed recurrence rates of 43%–48% and 57%, respectively.Intravesical Adriamycin and Mitomycin C appeared to be effective in the prophylaxis of recurrence during this observation period. The main side-effect was cystitis syndrome, which was observed in 10%–20% of the patients. There were no life-threatening adverse effects in this series of patients.


Japanese Journal of Cancer Research | 1988

COAMPLIFICATION OF THE hst‐1 AND int‐2 GENES IN HUMAM CANCERS

Masakazu Tsutsumi; Hiromi Sakamoto; Teruhiko Yoshida; Tadao Kakizone; Kenkichi Koiso; Takashi Sugimura; Masaaki Terada

The hst‐1 gene, previously designated the hst gene, was identified as a transforming gene by transfection assays of genomic DNAs from various types of human cancers. We analyzed for alterations of the hst‐1 gene in 18 bladder cancers, 23 renal cell carcinomas and 5 esophageal cancers. Although rearrangement of the gene was not detected in any of these samples, amplification of the hst‐1 gene was found in 4 samples of tumors, including an invasive bladder cancer, both primary esophageal cancer and its lymph node metastasis, and kidney metastasis of an esophageal cancer. The same degree of amplification of the int‐2 gene, the product of which has significant homology with the hst‐1‐encoded protein, was also observed in all of these DNA samples with amplified hst‐1 gene. This result indicates close chromosomal localization of the two genes, which were amplified as one amplification unit.


Fertility and Sterility | 1986

Lowered levels of bicarbonate in seminal plasma cause the poor sperm motility in human infertile patients

Naomichi Okamura; Yutaka Tajima; Hiromichi Ishikawa; Shinichi Yoshii; Kenkichi Koiso; Yoshiki Sugita

Both the adenylate cyclase activity and the motility of human sperm were stimulated by bicarbonate with the same concentration dependency. The correlation between bicarbonate levels in semen and the motility of sperm from the patients with male infertility was investigated. Bicarbonate in semen was found to originate mainly from the seminal vesicles, and a significant positive correlation was observed between bicarbonate levels and volume of semen. The motility of infertile sperm was also found to correlate positively to the seminal levels of bicarbonate. These results suggest that the lowered levels of bicarbonate in semen are at least in part responsible for the poor sperm motility in infertile patients, as a result of the failure in the activation of sperm adenylate cyclase.


The Journal of Urology | 1989

Immunocytochemical Demonstration of S Phase Cells by Antlbromobeoxyuribine Monoclonal Antibody in Human Prostate Adenocarcinoma

Ryosuke Nemoto; Katsunori Uchida; Toru Shimazui; Kazunori Hattori; Kenkichi Koiso; Masaoki Harada

Using a monoclonal antibody to bromodeoxyuridine and immunohistochemistry, we measured the incorporation of this thymidine analogue into the deoxyribonucleic acid of human prostate adenocarcinoma cells exposed in situ. Fifteen patients with prostate cancer were given an intravenous infusion of 500 mg. bromodeoxyuridine at needle biopsy to label tumor cells in the deoxyribonucleic acid synthesis phase (S phase). The tumor specimens were fixed with 70 per cent ethanol, embedded in paraffin, sectioned and stained by an indirect immunoperoxidase method using anti-bromodeoxyuridine monoclonal antibody as the first antibody. The results showed that this method demonstrated bromodeoxyuridine-labeled nuclei satisfactorily in tissue section. The bromodeoxyuridine labeling index, S phase fraction, was determined by counting the number of bromodeoxyuridine-labeled cells in the tissue sections. Grade 3 tumors averaged 4.37 +/- 0.48 per cent labeling versus 2.41 +/- 0.49 per cent in grade 2 tumors, and grade 1 tumor in the series had an S phase fraction of 1.36 +/- 0.39 per cent. The average S phase fractions for single gland, cribriform, fused and medullary were 1.16, 2.30, 3.74 and 4.95 per cent, respectively. The results obtained with S phase fraction measured with bromodeoxyuridine labeling proved to be comparable to the results of histological grade and growth pattern. Thus, the higher S phase fraction may indicate biological malignancy. Moreover, the degree of heterogeneity concerning S phase fraction distribution within prostate cancer tissue could be compared to the morphological appearance. Our preliminary results suggest that the measurement of bromodeoxyuridine labeling index in prostate cancer may prove to be a new objective and quantitative assay of biological potential of individual tumor.

Collaboration


Dive into the Kenkichi Koiso's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge