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Dive into the research topics where Ken-Ichiro Yoshida is active.

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Featured researches published by Ken-Ichiro Yoshida.


The Journal of Urology | 1996

Urinary pyridinoline and deoxypyridinoline as potential markers of bone metastasis in patients with prostate cancer

Shin-ichi Takeuchi; Kyouko Arai; Saitoh H; Ken-Ichiro Yoshida; Masakazu Miura

PURPOSEnThe levels of probable markers of bony metastatic disease were measured to evaluate their efficacy as predictors of disease and therapeutic outcome.nnnMATERIALS AND METHODSnUrinary pyridinoline, urinary deoxypyridinoline, serum alkaline phosphatase and serum osteocalcin were measured in patients with benign prostatic hyperplasia, clinically localized prostate cancer and prostate cancer with bone metastases. Also, urinary pyridinoline and deoxypyridinoline were compared in 2 groups of patients with metastatic prostate cancer of the bone who demonstrated progression or positive response to treatment. Urinary pyridinoline and deoxypyridinoline were determined by high performance liquid chromatography and were normalized to urinary creatinine.nnnRESULTSnLevels of pyridinoline and deoxypyridinoline in urine, and the level of alkaline phosphatase in serum from patients with bone metastatic prostate cancer were significantly greater than levels in patients with benign prostatic hyperplasia or localized prostate cancer. Serum osteocalcin levels failed to separate the 3 groups. Serial measurement of urinary pyridinoline and deoxypyridinoline was correlated with a positive response to treatment (decreased) and with clinical progression of disease (increased) before detection of new bone lesions by bone scintigraphy.nnnCONCLUSIONSnMeasurement of urinary pyridinoline and deoxypyridinoline may provide a useful marker of prostate cancer metastatic to bone and may be useful in monitoring the response to treatment.


Cancer | 1990

Two different lymph node metastatic patterns of a prostatic cancer

Saitoh H; Ken-Ichiro Yoshida; Yutaka Uchijima; Nobuyuki Kobayashi; Junji Suwata; Shigeyoshi Kamata

Among 753 autopsy prostatic cancer cases with a metastasis, 476 (63%) had a lymph node metastasis, whereas 277 (37%) did not. Two different lymph node metastatic patterns were observed: Type 1, combined metastasis involving the pelvic and paraaortic lymph nodes; and Type 2, metastasis to the paraaortic lymph nodes, but not to the pelvic lymph nodes. Type 1 metastasis cases showed a significantly more frequent metastasis to the bladder and rectum, and a less frequent metastasis to the lungs and liver. Hydronephrosis occurred more frequently (P < 0.01) in the Type 1. Furthermore, in the Type 1 cases the lymph node metastasis appeared to be continuously invasive, but in the Type 2 cases, metastasis appeared to be the skip type or some metastases may have spread via the vertebral vein bypass route and may have been associated with a hematogenous metastasis.


Cancer | 1994

Epidermal growth factor receptor content in human renal cell carcinomas.

Ken-Ichiro Yoshida; Akira Tosaka; Nobuyuki Kobayashi

Background. The expression of epidermal growth factor receptor (EGFR) mRNA has been demonstrated in human renal cell carcinomas (RCC), but few reports quantitate EGFR in RCC and correlate EGFR content with clinicopathologic findings.


Urologia Internationalis | 1994

Chlamydia trachomatis Infection in the Semen of Asymptomatic Infertile Men: Detection of the Antigen by in situ Hybridization

Ken-Ichiro Yoshida; Nobuyuki Kobayashi; Takeharu Negishi

The prevalence of Chlamydia trachomatis and other microbes was studied in 94 semen samples from asymptomatic infertile males. Simultaneously, we sought evidence for inflammation of the genital tract by determining the polymorphonuclear granulocyte (PMN)-elastase concentration in the seminal plasma. The C. trachomatis genome was detected in 8 cases using in situ hybridization. The antigen, however, was undetectable by enzyme-linked assay (Chlamydiazyme) in the same samples. Ureaplasma urealyticum was isolated from 16 cases. The PMN-elastase concentration in the semen positive for the C. trachomatis genome was significantly higher than in C. trachomatis-negative and U. urealyticum-positive cases, but no significant difference was observed between C. trachomatis-negative and U. urealyticum-positive cases. C. trachomatis trachomatis in situ hybridization-positive cases correlated well with C. trachomatis-specific IgA antibody positivity and a PMN-elastase concentration over 250 ng/ml. These findings suggest that in situ hybridization is a reliable method for the detection of C. trachomatis infection and that the presence of C. trachomatis, but not U. urealyticum, in the male genital tract correlated well with evidence of inflammation.


Urology | 1991

Possible metastatic routes via portacavalshunts in renal adenocarcinoma with liver metastasis

Saitoh H; Ken-Ichiro Yoshida; Yutaka Uchijima; Nobuyuki Kobayashi; Junji Suwata; Yasuhiko Nakame

Renal adenocarcinoma findings from autopsies on patients with and without liver metastasis (635 and 936 patients, respectively) were investigated concerning the mode of metastasis. The patients with liver metastasis showed a significantly higher frequency of metastases to the lungs, lymph nodes, contralateral kidney, adrenals, pancreas, spleen, peritoneum, and intestines; in the female patients, those with liver metastasis had a higher frequency of metastasis to the ovary and uterus than patients without liver metastasis. Some of the metastases to those organs are explainable by venous spread via portacaval shunts as well as ordinary hematogenous or lymphogenous spread, especially, those to the contralateral kidney, adrenals, spleen, intestines, or ovary.


Clinica Chimica Acta | 1989

The sugar-chain heterogeneity of human γ-glutamyl transferases from the reproductive system and kidney

Kyouko Arai; Ken-Ichiro Yoshida; Tsugikazu Komoda; Nobuyuki Kobayashi; Saitoh H; Yoshikatsu Sakagishi

The sugar-chain heterogeneity of gamma-glutamyl transferase (gamma-GTP, EC 2.3.2.2) from the human reproductive system (seminal plasma, prostate and testis) and kidney was investigated using the serial lectin affinity technique and their properties were compared. According to the results of serial lectin affinity chromatography, a possible sugar chains of enzymes from reproductive system were mainly of the hybrid type without fucose linkages to the innermost GlcNAc and/or the biantennary complex type sugar chains and a few were of the multiantennary complex-type with branched GlcNAc (beta 1-4) Man and bisecting complex type sugar chains. On the contrary, the major sugar chains of kidney gamma-GTP were of the multiantennary complex type and/or bisecting complex type sugar chains. Results of isoelectric focusing showed the gamma-GTP bound multiantennary complex type sugar chains to be the most acidic glycoprotein. Moreover, the biantennary type sugar chains were slightly more acidic than the high mannose and/or hybrid type sugar chains, varying with the degree of sialylation.


Clinica Chimica Acta | 1992

Differences in the enzymatic nature and the sugar-chain structure of γ-glutamyl transferase between normal and carcinomatous human kidney and prostate.

Kyouko Arai; Ken-Ichiro Yoshida; Tsugikazu Komoda; Nobuyuki Kobayashi; Yoshikatsu Sakagishi

The enzymatic and immunological nature, and the sugar chain structure, of gamma-glutamyl transferase (GGT) purified from tissues of benign prostatic hypertrophy (BPH), prostatic carcinoma (PCa) and renal cell carcinoma (RCa), were compared with those of the normal prostate (NP) and kidney (NK). The specific activities of GGTs in NP, NK, BPH, PCa and RCa were 78.9, 22.5, 105, 92.5 and 52.5 mU/mg protein, respectively. The molecular masses of GGTs from BPH, PCa and RCa were 72 kDa, 78 and 108 kDa, and 79 and 105 kDa, respectively. The Michaelis constants (Km), optimum pHs and the inhibition of GGT activities by several chemical compounds, revealed that the GGT from BPH, PCa and RCa was similar to that of normal GGT. Immunologically, the IgG fraction against anti-human seminal plasma GGT fused to the all of the GGTs tested. The sugar chain heterogeneities of the various GGTs, detected by the serial-lectin affinity technique, differed from one another. The sugar chain of GGT from BPH resembled the sugar chain from NP. On the contrary, the sugar chains of GGTs from PCa and RCa were markedly different from those from normal tissues. In the GGT from PCa, multi-antennary complex type sugar chains were more increased than the enzyme of NP. In general, as previously reported, the sugar chains of GGTs from carcinomatous tissues of prostate and kidney had an increased content of bisecting GlcNAc (beta 1-->4) containing complex type sugar chains. Moreover, the reductions of the biantennary complex type sugar chain with fucose linkage and the hybrid type sugar chain were obvious in the GGT from carcinomatous tissues of the prostate and kidney.


Clinica Chimica Acta | 1994

Demonstration and some properties of N-acetyl-β,d-hexosaminidase (HEX) C isoenzyme in human renal tissues: relative increase of HEX C activity in renal cell carcinoma

Ken-Ichiro Yoshida

The present study has demonstrated the presence of hexosaminidase (HEX) C activity in human renal tissues by an electrophoretic method. At the same time, its enzymatic properties, obtained as unbound fraction of renal tissue extracts passed through a concanavalin A Sepharose column, have been compared with those of HEX A and B. HEX C had the fastest electrophoretic mobility among HEX isoenzymes. The optimal pH of HEX C was 6.5, while that of HEX A and B was 4.9. The Km value of HEX C for synthetic glucosaminide substrate was 1.16 mmol/l, while that of HEX A and B was 0.18 mmol/l and 0.22 mmol/l, respectively. HEX C was inactive for a synthetic galactosaminide substrate, while HEX A and B were active. The percentage of HEX C activity to the total was 7.9 +/- 2.9% and 13.8 +/- 3.0% in the normal and the neoplastic tissues, respectively. A significant difference was observed between them (P < 0.01). These results indicate that the enzymatic properties of HEX C is quite different from those of A and B and also suggest that the determination of HEX C may become one of the useful clinical markers of the human renal cell carcinoma.


International Journal of Urology | 1994

EPIDERMAL GROWTH FACTOR BINDING BY MEMBRANES OF HUMAN RENAL CELL CARCINOMAS: ESTABLISHMENT OF AN EPIDERMAL GROWTH FACTOR RECEPTOR ASSAY FOR CLINICAL USE

Ken-Ichiro Yoshida; Akira Tosaka

In order to quantitate epidermal growth factor receptors (EGFR) in human renal cell carcinoma (RCC) tissues, the binding of isotope‐labeled epidermal growth factor (125I‐EGF) to pooled membrane samples from human RCC was studied. Specific EGF binding to membranes at 4C reached a plateau after 2 h of incubation and remained constant up to 8 h; specific binding at 25C reached a plateau after 30 min of incubation, then decreased gradually. 125I‐EGF binding to the membrane was displaced by both EGF and transforming growth factor‐aL, but not by insulin and basic fibroblast growth factor. Scatchard analysis of the specific EGF binding generated a straight line, indicating a single class of binding sites for EGF, with a dissociation constant (Kd) of 21.1 times1010M and a maximum number of binding sites of 57.2fmol/mg membrane protein. When the protein concentration in the incubation medium was adjusted from 0.71mg/ml to 2.84 mg/ml, Scatchard analysis revealed identical Kd values, and the maximum number of binding sites was proportional to the protein concentration. These results demonstrate the presence of EGFR on RCC membranes and indicate that these receptors can be studied quantitatively.


Andrologia | 2009

Purification and properties of gamma-glutamyl transpeptidase from human testis

Ken-Ichiro Yoshida; Kyouko Arai; Nobuyuki Kobayashi; Saitoh H

Summary Gamma‐glutamyl transpeptidase was purified to apparent homogeneity from human testis by DEAE cellulose, acetone, precipitation, fractionation by ammonium sulphate, Sephacryl S‐200 chromatography, Q‐Sepharose chromatography and S‐Sepharose chromatography following solubilization of the enzyme by Triton X‐100. The purified enzyme had an apparent molecular weight of 54 KDa by Sephacryl S‐200 gel filtration. On sodium dodecyl sulphate polyacrylamide gel electrophoresis, two submits of molecular weight 38 KDa and 14 KDa were obtained. The purified enzyme showed a single band with pI 6.0. The Km value and the optimal pH of the enzyme for L‐γ‐glutamyl‐3‐carboxy‐4‐nitroanilide were found 1.09 mmol/l and 8.2–8.5, respectively. Serial lectin binding study with various lectin columns showed that the majority of the asparagine‐linked oligosaccharides of the enzyme was complex‐types. However, complex‐types with bisecting N‐acetylglucosamine residue were not recognized.

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Saitoh H

Saitama Medical University

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Kyouko Arai

Saitama Medical University

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Yutaka Uchijima

Saitama Medical University

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Tsugikazu Komoda

Saitama Medical University

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Akira Tosaka

Saitama Medical University

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Junji Suwata

Saitama Medical University

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Masakazu Miura

Saitama Medical University

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Shigeyoshi Kamata

Saitama Medical University

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