Hidenori Takaba

Increased mast cells in the limiting membrane of seminiferous tubules in testes of patients with idiopathic infertility.

In the course of our histological studies on the testes of idiopathically infertile men, we found an increased number of mast cells in the limiting membrane of the seminiferous tubule. In 16 patients with idiopathic infertility, quantification of mast cells within the limiting membrane of the seminiferous tubule was performed. There apparently was a tendency to increased numbers of mast cells in the seminiferous tubule wall with decreased sperm count and an average Johnsen score for each tubule. These findings suggest that quantification of mast cells in the seminiferous tubule wall may be a useful marker in the histopathological evaluation of testis biopsies in patients with idiopathic infertility.

Quantifying Thread Tension is of Clinical Use in Stamey Bladder Neck Suspension: Analysis of Clinical Parameters

Tension on the nylon loops in a Stamey endoscopic bladder neck suspension has been quantified for the first time by using a spring scale. Clinical data were compared between 14 patients with undetermined tension (control group) and 57 with tension of either 400, 600, 700, 800 or 1,000 gm. Experimental study during the operation demonstrated that changes in the posterior urethrovesical angle and distance that the bladder neck was elevated were not proportional to the tension: the lower the thread tension the larger the change in these 2 parameters. Compared to the control group a significant decrease in the period of suprapubic drainage was observed in patients with quantified tension. Operative success was obtained in 86 per cent of the control group and 91 per cent of those in whom tension was quantified. A tension of 400 to 600 gm. seemed to be most appropriate for a successful outcome. We conclude that quantifying the thread tension is useful to prevent either over-tightness of the nylon loops or insufficient suspension of the bladder neck, and that with a spring scale it is easy to instruct a beginner on how tightly to tie the threads.

Response of the Isolated Human Seminiferous Tubule to Prostaglandins F 1ɑ , F 2ɑ , E 1 and E 2

Abstract In an attempt to ascertain whether prostaglandins alter the in vitro contractile activity of the human seminiferous tubule, the effects of prostaglandins on the isolated human seminiferous tubule were examined by recording the intratubular pressure with a servonull pressure measuring device. We describe here the first response of the human seminiferous tubule to prostaglandins. Prostaglandin F2ɑ (10−9 M to 10−6 M) produced contractions of the seminiferous tubules In a dose-dependent manner. In contrast, prostaglandins Flɑ (10−8 M to 10−6 M), E1 (10−9 M to 10−6 M) and E2 (10−8 M to 10−6 M) produced relaxations of the seminiferous tubules which were dose dependent. The results from these experiments suggest that prostaglandins modulate the in vitro contractility of the human seminiferous tubules and thus may regulate the transport of spermatozoa and tubular fluid to the rete testis.

In-vitro contractility of human seminiferous tubules in response to testosterone, dihydrotestosterone and estradiol

SummaryThe effects of steroids (testosterone, dihydrotestosterone and estradiol) on human seminiferous tubules in vitro were ascertained by recording the intratubular pressure with a servonull micropressure measuring device. We describe here the first response of the human seminiferous tubule to steroids. Testosterone and dihydrotestosterone had a biphasic effect on tubular contractility. Higher doses of both testosterone and dihydrotestosterone induced contractions of the seminiferous tubules whereas lower doses of these compounds induced relaxation. Estradiol (10-9 M to 10-6 M) induced relaxation of the seminiferous tubules in a dose-dependent manner. The results from these experiments suggested that steroids may be involved in the control of contraction of the human seminiferous tubule and may regulate the movement of spermatozoa from the tests.

Successful treatment of oligospermic and azoospermic men with α1-blocker and β-stimulator: new treatment for idiopathic male infertility

We studied the effect of oral administration of alpha 1-blocker and beta-stimulator on 20 idiopathically infertile men. Bunazosin (alpha 1-blocker, 2 mg/day) and procaterol (beta-stimulator, 100 micrograms/day) were given orally twice daily for 5 months. The administration of alpha 1-blocker and beta-stimulator elicited an increase in sperm output and seminal volume in 16 patients (80%). The increase in sperm output seems to be associated with relaxations of myoid cells, which lead to dilatation of stenotic areas of seminiferous tubules, occurring discontinuously, and subsequent maintenance of good tubular fluid flow. No adverse effects were observed in this series.

Determination of the relative probability for prostate cancer to avoid unnecessary biopsy.

Abstract  Background:  To investigate whether using a new concept of relative probability for prostate cancer (RPpca) can increase sensitivity and specificity in detecting prostate cancer.

Evidence for Innervation of the Myoid Cell in the Human Seminiferous Tubule

Although the existence of the seminiferous tubule contractions attributed to myoid cells is established, the control of the contractions is poorly understood. Recently, we have suggested the possible neural control mechanism for contractility of the human seminiferous tubule. In an effort to identify the nerve supply to the myoid cells in the human seminiferous tubules, we studied the paraffin sections of biopsied testicular specimens using a protein silver impregnation technique (Bodians method). Here we demonstrate evidence for the presence of nerve fibers close to the myoid cells. It is highly suggested that contraction of the human seminiferous tubule may play an important role in the transport of spermatozoa, and neurohumoral regulatory mechanism may partly exist in this connection.

Identification of collagens in the human testis.

SDS-PAGE of pepsin-solubilized collagens obtained from testes of elderly men revealed types I, III, V, and VI but not type IV. The total collagen content was 21.3 +/- 1.96% (mean +/- SD) as determined by hydroxyproline assay. The ratio for the pepsin-soluble fraction was 7.98 +/- 3.27%, i.e. very low as compared with other tissues. Type I collagen was determined by SDS-PAGE of cyanogen bromide cleavage of the pepsin-insoluble residue.

Overall morphology of basement membrane of rat seminiferous tubule as revealed by scanning electron microscopy.

Scanning electron microscopic observation of the basal surface of the basement membrane of the rat seminiferous tubule has revealed that the basement membrane appears to be like a tiled floor, and formation of meshwork structure of collagen fibrils is evident in some exfoliated areas of basement membrane. This meshwork structure is considered to ensure fluid regulation from the intertubular medium toward the lumen of the seminiferous tubules.