Katsuya Nakano

Changes in the endocrine environment of the human prostate transition zone with aging: simultaneous quantitative analysis of prostatic sex steroids and comparison with human prostatic histological composition.

It is well‐known that the incidence of benign prostatic hyperplasia (BPH) increases with aging. The age‐dependent changes in the ratio of serum sex steroid concentrations may play a role in BPH development. To clarify the relationship between the prostatic tissue concentrations of these steroids and age, we established a precise method of simultaneous quantitative analysis for prostatic sex steroids and used this method to investigate the tissue concentrations of three major sex steroids (testosterone, dihydrotestosterone, and estradiol) in the human prostate.

Stimulative Effect of Transforming Growth Factor-β on Collagen Synthesis by Human Prostatic Stromal Cells In Vitro

Background:

Developmental changes in cyclooxygenase mRNA expression in the kidney of rats.

Abstract  Prostaglandins, synthesized by cyclooxygenase (COX), regulate renal hemodynamics and also epithelial water and solute transport. To determine whether COX mRNA expression changes with age, we studied expression in renal medulla and in cortex in developing rats at various ages. We also examined age-related changes in COX mRNA expression induced by lipopolysaccharide (LPS). COX mRNA was quantitatively analyzed in a real-time polymerase chain reaction (PCR) with dual- labeled fluorogenic probes. COX-1 mRNA expression did not change with age in cortex or medulla. COX-2 mRNA expression was highest in 1-week-old rats and lowest in 4- and 8-week-old rats. Lipopolysaccharide treatment did not alter COX-1 mRNA expression in infantile or adult rats. In adults, LPS at 1, 5, and 10 mg/kg induced COX-2 mRNA expression in renal medulla; the higher doses, 5 and 10 mg/kg, induced COX-2 expression in cortex. In infantile rats, COX-2 mRNA, already high in the unmanipulated state, was further increased by only 1 mg/kg LPS in both renal cortex and medulla. Age- related changes in the expression of COX-2 mRNA might be responsible for changing physiologic characteristics of renal function during postnatal development in rats, and may be important in renal cortical development.

Contrast Enhancement of PC-3 Prostate Cancer for Magnetic Resonance Imaging: Animal Studies Using Tumor-Localizing MN-Metalloporphyrin (THF-MN-ASP)

PURPOSE The objective of the present study was to test, in nude mouse PC-3 tumors, the contrast enhancement of 2,4-bis(1-tetrahydro-fulfuroxyethyl)-deuteroporphynyl(IX)-6- 7-bisaspartic acid (THF-Mn-ASP), which is a hematoporphyrin derivative and depresses T1 relaxation time on magnetic resonance (MR) imaging. MATERIALS AND METHODS THF-Mn-ASP or gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) was intravenously administered, and MR imaging of the tumors transplanted into nude mice was performed on T1-weighted images. RESULTS After administration of THF-Mn-Asp, the signal intensity of PC-3 tumors increased and the tumor/muscle intensity ratio was highest at about 1 hour. The tumor/muscle intensity ratio, in contrast, was highest at about 5 minutes after administration of Gd-DTPA. The increase in intensity ratio was 32% in THF-Mn-ASP and 28% in Gd-DTPA. CONCLUSION The preliminary study suggested that THF-Mn-Asp has a predilection to accumulate in PC-3 tumors, and it seems to provide good contrast enhancement with tumor specificity for MR imaging.

Transurethral balloon laser thermotherapy: effects of a directionally shielded balloon in canine prostates.

Background: Transurethral balloon laser thermotherapy (TUBAL‐T) improves objective, but not subjective, symptoms of benign prostatic hyperplasia (BPH). We studied whether or not an Nd:YAG laser beam with a shielded balloon could successfully irradiate the prostate during TUBAL‐T in a selective manner, to improve the subjective symptoms.

Acute Renal Failure in a Patient with Chronic Glomerulonephritis after the Administration of Luteinizing Hormone‐Releasing Hormone Analogue Given for Rectal Obstruction Due to Prostate Cancer

We report a case in which rectal obstruction due to prostate cancer was exacerbated due to an ileus after the administration of luteinizing hormone‐releasing hormone analogue. The obstruction led to copious vomiting, dehydration and renal failure which necessitated hemodialysis. Improvement of the patient was noted four weeks after the start of hormonal treatment with a decrease in rectal obstruction concomitant with decreases in testosterone and prostate specific antigen levels.

Expression of Heparin-binding Epidermal Growth Factor-like Growth Factor(HB-EGF) in Human Renal Cell Carcinoma

Background: The levels of expression of Heparin binding-epidermal growth factor like growth factor (HB-EGF) mRNA in tumor tissues and normal tissues of the excised kidney were compared in order to clarify the role of HBEGF inrenal cell carcinoma (RCC) derived from the proximal tubule. Method: Normal and tumor tissues were collected from surgical specimens of 16 cases pathologically diagnosed with RCC. Total RNA was extracted from these samples, and the level of expression of HB-EGF mRNA was measured by real-time quantitative PCR using a TaqMan probe after reverse transcription. Glyceraldehyde phosphate dehydrogenase (GAPDH) was used as an internal standard. The expression levels of HB-EGF mRNA in normal and tumor tissues of the same case were compared, and statistical analysis was performed to evaluate the association between the expression level and various clinical-pathological factors in RCC. Results: Expression of HB-EGF mRNA was detected in 82% (13/16) of the normal tissues and 63% (10/16) of the tumor tissues. The expression level in the normal tissues was significantly 7-fold higher than that in the tumor tissues. No significant association was detected between the expression of HB-EGF mRNA and the clinical stage or prognosis of RCC. However, the pathological findings indicated that negative expression of ratio of HB-EGF was higher in RCC with more-advanced malignant progression. Conclusion: Our results indicated that it was unlikely that HB-EGF might play a role in determining the aggressiveness or clinical features in RCC. However, the decreased expression of HB-EGF mRNA in RCC tissues indicates that tumorigenesis of RCC may disrupt the normal regulatory system of HB-EGF.

A CASE OF URETERAL ENDOMETRIOSIS

A 49-year-old woman was admitted to our hospital due to macroscopic hematuria. Contrast-enhanced computed tomography revealed left hydronephrosis, a tumor at her left ureter, pseudoaneurysm and ovarian cystoma. Prior to the operation, the tumorous lesion was considered as left ureteral cancer without metastasis (cT4N0M0; stage IV). Left nephroureterectomy was performed. After the surgery, pathological examination revealed that this lesion was extrinsic endometriosis originating from the ureter.We here report this case of ureteral endometriosis that presented with atypical clinical findings along with a review of the literature.

Clinical study on poor PSA response to initial endocrine therapy with MAB or estrogenic drugs for treatment of prostate cancer

PURPOSE The prostate specific antigen (PSA) level usually is lowered in response to initial endocrine therapy even in advanced cases of prostate cancer, but in some cases, it is not. We examined the cases in which the PSA level was not sufficiently lowered by initial endocrine therapy with maximal androgen blockade (MAB) or estrogenic drugs. MATERIALS AND METHODS The subjects were 20 patients with prostate cancer diagnosed between January 1992 and December 2005 whose PSA level was not lowered below 10 ng/ml after initial endocrine therapy with MAB or estrogenic drugs. We investigated the frequency of cases, pretreatment PSA levels, PSA nadir levels after initial endocrine therapy and throughout the therapy, PSA response to second line therapy, and the prognosis. RESULTS The PSA level was not lowered below 10 ng/ml after initial endocrine therapy with MAB or estrogenic drugs in 4.9% of the cases. Cancer-specific survival rates in all cases were extremely poor, 75.0% at 1 year and 14.7% at 3 years. Prognosis tended to be worse in patients with a higher PSA nadir level throughout the therapy and on whom second therapy was not effective, although the difference was not statistically significant. CONCLUSION The patients whose PSA levels were not lowered sufficiently by MAB or estrogenic drugs had an extremely poor prognosis. These results are useful in planning the therapy, and in explaining the status or future prospective of the disease to patients and their families.