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Featured researches published by Yutaka Kamiyama.


Japanese Journal of Clinical Oncology | 2008

Focal Therapy with High-intensity-focused Ultrasound in the Treatment of Localized Prostate Cancer

Satoru Muto; Takashi Yoshii; Keisuke Saito; Yutaka Kamiyama; Hisamitsu Ide; Shigeo Horie

BACKGROUND We evaluated the efficacy and feasibility of high-intensity-focused ultrasound (HIFU) for localized prostate cancer. METHODS Seventy patients received HIFU using Sonablate((R)) 500 (Focus Surgery, IN, USA). In patients whose cancer was confined to only one lobe by multi-regional biopsies, total peripheral zone and a half portion of transitional zone were ablated (focal therapy). Otherwise, patients received whole organ ablation (whole therapy). Scheduled biopsies were performed at 6 and 12 months after treatment. Pre- and post-HIFU serum testosterone levels were measured. Result The 2-year biochemical disease-free survival (DFS) rates in patients at low, intermediate and high risk were 85.9, 50.9 and 0%, respectively, (P = 0.0028). After 12 months, 81.6% (40/49) of patients were biopsy negative; 84.4% in patients who received whole therapy, whereas 76.5% in those with focal therapy. The 2-year biochemical DFS rates for the patients at low and intermediate risk was 90.9 and 49.9%, respectively, in patients with whole therapy, whereas 83.3 and 53.6% in patients with focal therapy. In patients without neoadjuvant androgen deprivation, serum testosterone levels continuously decreased after whole therapy, whereas no changes were seen in those with focal therapy. The patients whose follow-up biopsies were positive tended to have significantly higher changes in prostate-specific antigen levels than biopsy-negative patients. CONCLUSIONS In patients with low-risk prostate cancer, HIFU monotherapy resulted in comparable immediate cancer control with other modalities. Particularly, focal therapy might offer a feasible minimally invasive therapeutic option, which maintained serum testosterone level. To our knowledge, this is the first report that whole, but not focal, therapy affects the serum testosterone level.


Urologia Internationalis | 1999

Bilateral Emphysematous Pyelonephritis with Autosomal-Dominant Polycystic Kidney Disease Successfully Treated by Conservative Method

Hirofumi Shimizu; Kyouichi Hariu; Yutaka Kamiyama; Hiroshi Tomomasa; Tatsuo Iizumi; Tsunetada Yazaki; Takashi Umeda

Emphysematous pyelonephritis (EPN) is an uncommon and potentially life-threatening necrotizing inflammation of the renal parenchyma. EPN associated with autosomal dominant polycystic kidney disease (ADPCK) is extremely rare. We report such a case of bilateral EPN with ADPCK that was successfully treated with conservative methods. To our knowledge, our case is only the second to document bilateral EPN occurring with ADPCK and the first one to be treated successfully with conservative methods.


International Journal of Urology | 1999

Ureteropyeloscopy in the diagnosis of patients with upper tract hematuria: An initial clinical study

Tsunetada Yazaki; Yutaka Kamiyama; Hiroshi Tomomasa; Hirofumi Shimizu; Yoshinori Okano; Tetsuro Iiyama; Tatsuo Iizumi; Takashi Umeda

Background: To study the usefulness and safety of ureteropyeloscopy in the diagnosis of upper tract hematuria of unknown etiology by standard diagnostic methods.


Urologia Internationalis | 1997

Immunohistochemical Studies of Proliferating Cell Nuclear Antigen and Cathepsin D in Transitional Cell Carcinoma of the Urinary Bladder

Tatsuo Iizumi; Tetsuro Iiyama; Wataru Tanaka; Eiko Okada; Yutaka Kamiyama; Yoshinori Okano; Satoshi Sato; Tsunetada Yazaki; Takashi Umeda; Tetsuo Imamura

Immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and cathepsin D was performed on 60 transitional cell carcinoma (TCC) specimens from 60 patients with bladder cancer. The percentage of PCNA-positive cells (PCNA-labelling index) was determined by counting 500 or 1,000 cells, and cathepsin D expression was graded according to the extent of immunoreactivity to anti-cathepsin D antibody. The PCNA-labelling index was significantly higher in high-grade and high-stage tumors compared to that in low-grade and low-stage tumors. Cathepsin D was highly positive in grade-1 tumors. In contrast, 82% of grade-3 tumors and 76% of advanced tumors showed negative or low reactivity to anti-cathepsin D. Groups of high PCNA-labelling index and negative cathepsin D had significantly poorer prognoses compared to those of the low PCNA group and cathepsin D highly positive group, respectively, in univariate analyses. However, neither of these two factors were independent prognostic factors in multivariate analyses. These results suggest that the PCNA-labelling index and cathepsin D expression may indicate the malignant potential of TCC and may be able to provide additional information for predicting survival when stratifying for grade of bladder cancer.


International Journal of Clinical Oncology | 2007

Incidentally discovered adrenal myelolipoma associated with hyperthyroidism

Hisamitsu Ide; Yuichi Terado; Takashi Nakagawa; Keisuke Saito; Yutaka Kamiyama; Satoru Muto; Hiroshi Okada; Tetsuo Imamura; Shigeo Horie

Adrenal myelolipomas are uncommon, nonfunctioning tumors that tend to be discovered incidentally on imaging. Such tumors are composed of mature adipose tissue and hematopoietic elements, but their etiology is still unknown. Thyroid hormones have important effects on development, growth, and metabolism, as well as tumorigenesis. We report a case of adrenal myelolipoma in a patient with hyperthyroidism; this benign tumor expressed both thyroid hormone receptor α and β.


BJUI | 2008

Inhibitory effects of nicorandil, a KATP channel opener and a nitric oxide donor, on overactive bladder in animal models

Yutaka Kamiyama; Satoru Muto; Hitoshi Masuda; Hisamitsu Ide; Nobuhiko Ishizuka; Keiji Saito; Shigeo Horie

To investigate the effects of nicorandil, an ATP‐sensitive potassium (KATP) channel opener with a nitric oxide (NO) donor property, on overactive bladder (OAB) in animal models. Nicorandil is currently used clinically to treat ischaemic heart disease.


Journal of Clinical Microbiology | 2006

Enumeration of Bacterial Cell Numbers and Detection of Significant Bacteriuria by Use of a New Flow Cytometry-Based Device

Hiroshi Okada; Toshiro Shirakawa; Akinobu Gotoh; Yutaka Kamiyama; Satoru Muto; Hisamitsu Ide; Yukio Hamaguchi; Shigeo Horie

ABSTRACT A new, automated flow cytometry-based urine bacterium analyzer (UBA) was developed. We assessed the UBA for linearity of measurement, reproducibility of results, carryover rate, and correlation of measured results with those determined by urine culture. We also evaluated its ability to screen urine samples for significant bacteriuria. The UBA showed excellent linearity and a minor carryover rate. Results from the UBA were highly reproducible, and in between-run precision assays, the coefficients of variation for the UBA results were smaller than those for the urine culture results. Two hundred seventy-three urine specimens from patients attending the outpatient clinics of two university-based hospitals were examined. The results for the UBA were compared with those for urine culture. The UBA detected significant bacteriuria with a sensitivity of 96.6%, a specificity of 79.9%, a positive predictive value of 57.0%, a negative predictive value of 98.8%, a false-positive rate of 15.8%, a false-negative rate of 0.7%, and an accuracy of 83.5%. These results were comparable to or better than those obtained with previously reported screening procedures. The UBA can perform accurate enumeration of bacterial cells automatically in 90 seconds and can be used for the screening of significant bacteriuria.


International Journal of Urology | 2007

Spindle cell lipoma of the spermatic cord

Hisamitsu Ide; Takashi Nakagawa; Yutaka Kamiyama; Satoru Muto; Tetsuo Imamura; Shigeo Horie

Abstract:  Spindle cell lipoma usually occurs as a solitary, subcutaneous, circumscribed lesion in the back, posterior neck or shoulders of older men. As a paratesticular tumor, spindle cell lipoma is extremely rare. Herein we report the second case of spindle cell lipoma of the spermatic cord in the published reports. The tumor comprised mature adipocytes and uniform spindle cells within thick ropey collagen bundles and mast cells. Immunohistochemical studies showed spindle cells positive for CD34, a diagnostic feature of this tumor.


Archives of Andrology | 2002

Gonadal Function in Patients with Testicular Germ Cell Tumors

Hiroshi Tomomasa; S. Oshio; Y. Ashizawa; Yutaka Kamiyama; Yoshinori Okano; Tetsuro Iiyama; Satoshi Sato; Hirofumi Shimizu; Takashi Umeda

The gonadal function of 18 patients with testicular germ cell tumors was evaluated. Seminal parameters after orchiectomy were examined in 15 patients. Six of them were available for follow-up observation after 2 or 3 courses of adjuvant chemotherapy. Serum gonadal hormones before and after orchiectomy were evaluated in 7 patients (testosterone and PRL were not examined in one patient). Five of 15 (33.3%), 8 of 15 (53.3%), 13 of 15 (86.7%), 7 of 13 (53.8%), and 9 of 12 (75.0%) had abnormal values in seminal volume, sperm concentration, motility, morphology, and vitality, respectively. The sperm concentration gradually improved after chemotherapy following orchiectomy in 5 of 6 (83.3%) patients. In all the patients examined, serum levels of follicular stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) increased after orchiectomy. Serum levels of testosterone increased in 4 patients, but decreased in 2 after orchiectomy. These findings suggest that several factors, including preexisting intrinsic defect and disturbance of the hypothalamus-pituitary-gonadal axis, are involved in the deterioration of gonadal function in patients with testicular germ cell tumors.


Japanese Journal of Clinical Oncology | 2010

Novel Germ Line Mutation p53-P177R in Adult Adrenocortical Carcinoma Producing Neuron-specific Enolase as a Possible Marker

Hisamitsu Ide; Yuichi Terado; Shino Tokiwa; Kojiro Nishio; Keisuke Saito; Shuji Isotani; Yutaka Kamiyama; Satoru Muto; Tetsuo Imamura; Shigeo Horie

Adrenocortical cancer (ACC) is a rare and aggressive endocrine tumor. The patient presented with a large retroperitoneum tumor and lung metastases. Removal of the adrenocortical tumor with part of the transverse colon and tail of the pancreas, spleen and kidney was successfully performed following chemotherapy. Levels of serum neuron-specific enolase (NSE) were found to be markedly high before surgery and may be clinically useful markers for monitoring tumor status during management. Immunohistochemical studies showed that the cancer cells were positive for NSE and overexpression of p53. We identified a novel germ line variant of the 177 mutant (Pro to Arg; P177R) of p53 by genomic sequencing. The genetic and biochemical data presented in this case confirm the importance of screening for p53 status in ACC with inherited cancer syndrome.

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Hiroshi Okada

Dokkyo Medical University

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