Search PubMed⌕ Search

Biomedical subjects

H Yazawa

Publications and source records attributed to H Yazawa.

71 records · Page 4Linked to original sources
PubMed1986

Effect of androgen on ornithine decarboxylase activity in androgen-dependent mouse mammary tumor (Shionogi Carcinoma 115) and its androgen-independent subline (CS 2).

The activity of ornithine decarboxylase in androgen-dependent mouse mammary tumor (Shionogi Carcinoma 115) was reduced to 25% by castration of tumor-bearing mice and restored to the normal level 12 h after administration of testosterone or 5 alpha-dihydrotestosterone. Administration of estradiol-17 beta to the tumor-bearing castrated mice also stimulated the enzyme activity while progesterone and cortisol had little effect. On the other hand, the enzyme activity was affected by neither castration nor androgen injection to CS 2, which is a subline of SC 115 and completely independent of androgen for growth. The inhibition of ornithine decarboxylase activity in SC 115 by injecting alpha-difluoromethylornithine did not affect the enhancement of RNA polymerase I activity by androgen, showing independent elevation of the levels of the two enzymes by androgen.

Androgens↗
PubMed1986

[Establishment of inbred rabbit strains].

Two inbred rabbit strains, JWY-NIBS and NWY-NIBS, were established by full-sib mating in the Nippon Institute for Biological Science, Laboratory Animal Research Station. The origin, breeding history, and biological characteristics of the two inbred strains are as follows. 1. JWY-NIBS: Origin: Japanese white rabbits which had been originally kept at a farm near mount Takao, then transferred to another farm in Fuchu and maintained as a closed colony for a long time. Date of the first full-sib mating: April, 1964. Date of the 20th full-sib mating: June, 1981. Age of maturity: 7-month-old in females, 7.5-month-old in males. Body weight at maturity: 2.8-3.0 kg in females, 2.8-2.9 kg in males. Marker genes: Hemopexin; HxS. Esterase; Est-1s. alpha-Protein; F type. 2. NWY-NIBS: Origin: A strain III of New zealand white rabbits imported from the Jakson Laboratory in USA. Date of the first full-sib mating: November, 1967. Date of the 20th full-sib mating: July, 1982. Age of maturity: 7.5-month-old in females, 8-month-old in males. Body weight at maturity: 2.8-3.0 kg in females, 2.9-3.1 kg in males. Marker genes: Hemopexin; HxF. Esterase; Est-1S. Est-2f. alpha-Protein; S type.

Animals↗
PubMedDate not supplied

Modulation of neutrophil apoptosis by psychological stress and glucocorticoid.

Neutrophils play a pivotal role in host defense against bacterial infection, however, these cells may have a harmful effect on normal tissues under certain pathological conditions. We demonstrate here that apoptosis of these cells is modulated by psychophysical stress and its related hormones, suggesting that psychoneural systems may exert an effect on host defense through modulating neutrophil survival.

Animals↗
PubMedDate not supplied

Acute effects of tumor necrosis factor-alpha on testicular germ cell apoptosis and vascular neutrophil adhesion in rats.

Acute effects of tumor necrosis factor-alpha (TNF-alpha) on testicular germ cell apoptosis and vascular neutrophil adhesion were investigated in rats. Acute administration of TNF-alpha did not show a significant increase in percentage of apoptotic tubules and apoptotic germ cells. TNF-alpha administration did not enhance neutrophil adhesion score in the intertubular and subtunical vein. TNF-alpha does not acutely influence testicular germ cell apoptosis and vascular neutrophil adhesion in rats.

Androgens↗
PubMedDate not supplied

The use of ebastine, a mast cell blocker, for treatment of oligozoospermia.

The effect of mast cell blocker (ebastine) on semen quality was evaluated in 15 idiopathic oligozoospermic males. Ten milligrams/day of ebastine was administered orally for 3 months. Nine cases (66.7%) showed definite improvement in the semen quality. The wives of 3 patients (20%) became pregnant within 6 months of the initial treatment. It would appear that mast cell blocker (ebastine) significantly improves semen quality in men with idiopathic oligozoospermia.

Adult↗
PubMedDate not supplied

Localization of the sex-determining region-Y gene in XX males.

Localization of the sex-determining region Y (SRY) was investigated in 2 XX males. Metaphase chromosomes from peripheral lymphocytes were stained by fluorescence in situ hybridization using DXZ1 and SRY probes. An identical hybridization signal with the SRY probe was found on an X chromosome in both cases. The karyotype of the 2 cases was 46,XX, t(X;Y)(p22.3;p11.3). It would appear that XX male is the presence of a Y-chromosome fragment transferred to the X-chromosome short arm by unequal interchange between homologous regions in the short arms of sex chromosomes.

Adult↗
PubMedDate not supplied

Detection of chromosome 15 deletion in Prader-Willi syndrome using fluorescence in situ hybridization.

Deletion of chromosome 15 was investigated in 6 patients with Prader-Willi syndrome (PWS) using chromosome and fluorescence in situ hybridization (FISH) analysis. Although chromosome analysis using G-banding methods revealed the deletion of 15q11-q13 in only 3 cases, staining by FISH using D15S11 and/or small nuclear ribonucleoprotein polypeptide N (SNRPN) probes detected chromosome 15 deletion in all cases. It would appear that FISH analysis is an effective diagnostic test for the detection of chromosome 15 deletion in patients with PWS.

Adolescent↗
PubMedDate not supplied

Laparoscopic varicocelectomy in adolescents using an ultrasonically activated scalpel.

Ten laparoscopic varicocelectomies were performed using an ultrasonically activated scalpel to divide spermatic vessels in adolescents. The mean operation time was 35 (25-46) min. There were no intraabdominal viscelar or vascular complications, and no postoperative analgesia was required. These findings suggest that laparoscopic varicocelectomy using an ultrasonically activated scalpel may be a valuable treatment in the adolescent.

Adolescent↗
PubMedDate not supplied

Sutureless vasovasostomy using new vascular closure staples in rats.

To evaluate the efficacy of sutureless vasovasostomy using vascular closure staples, 20 male Sprague-Dawley rats were used for the study. In each rat, a sutureless vasovasostomy using vascular closure staples was performed on a randomly selected side, and a conventional end-to-end microsutured anastomosis was performed on the opposite side. Operation time was significantly shorter for sutureless vasovasostomy using vascular staples (p < .001). Four weeks after the surgery, however, patency rate and granuloma formation were not different for conventional end-to-end vasovasostomy vs. sutureless vasovasostomy. These findings suggest that sutureless vasovasostomy is simple to perform and requires fewer special technical skills. This procedure may provide an alternative to the conventional vasovasostomy.

Animals↗
PubMedDate not supplied

Reevaluation of testicular biopsies of males with nonobstructive azoospermia in assisted reproductive technology.

Spermatogenesis was investigated in seminiferous tubules of 100 males with nonobstructive azoospermia. Forty-four (44%) cases had Sertoli-cell-only syndrome, 23 (23%) had spermatogonium in the tubules, 17 (17%) had primary spermatocyte in the tubules, and 16 (16%) had round or late spermatid in the tubules. No cases showed secondary spermatocyte present in the tubules. The mean serum follicle-stimulating hormone (FSH) in males with nonobstructive azoospermia was significantly higher than that in males with obstructive azoospermia (p < .001). The mean concentrations of serum FSH in cases with Sertoli-cell-only syndrome and spermatogonium in the tubules were significantly higher than those in cases with primary spermatocyte and spermatid in the tubules (p < .05-.001). The results indicate that the evaluation of testicular histology using the type of germ cells present in seminiferous tubules is available for assisted reproductive technology.

Biopsy↗
PubMedDate not supplied

Effect of testosterone replacement therapy on serum PSA in patients with Klinefelter syndrome.

The effect of testosterone replacement therapy on serum prostate-specific antigen (PSA) was investigated in 11 patients with Klinefelter syndrome. Significant increases in serum testosterone level and prostate volume were observed after testosterone replacement therapy. However, serum PSA level did not change after testosterone replacement therapy. It would appear that serum PSA is not influenced by exogenous testosterone in patients with Klinefelter syndrome.

Adult↗
PubMedDate not supplied

Stress and testicular germ cell apoptosis.

Chronic immobilization stress provokes an increase in serum corticosterone, which causes the decline in testosterone concentration. The stress and glucocorticoid administration induce germ cell apoptosis in rat testes. The cell type that has been shown to undergo apoptosis is spermatogonia. Since a potent glucocorticoid receptor agonist completely suppressed glucocorticoid induced germ cell apoptosis, the regulation of transcription of gene mediated by the glucocorticoid receptor may enhance apoptosis of testicular germ cells. The apoptosis of testicular germ cells would involve certain specific gene activities and proteins, including Bcl-2 family, p53, and Fas. Molecular investigations may help to determine whether the different pathways possess mechanisms of germ cell apoptosis induced by somatic stress and glucocorticoids.

Animals↗
PubMedDate not supplied

Results and complications of laparoscopic Palomo varicocelecctomy.

The laparoscopic Palomo varicocelectomy were performed in 38 males with left-sided varicocele. The mean operation time was 37 (25-56) min. There were no intra-abdominal visceral or vascular complications during operation. Neither testicular atrophy nor recurrence was observed postoperatively. However, hydrocele formation was found in two (5.3%) patients. These findings suggest that laparoscopic Palomo varicocelectony is a safe and effective procedure for patients with varicocele.

Adolescent↗
PubMedDate not supplied

Microinsemination of rabbit oocytes with heat-treated sperm: embryonic development.

A study was conducted to evaluate the ability of rabbit oocyte to develop to the pronuclear stage and subsequent development if injected with heat-treated sperm. The rate of fertilization of eggs after microinjection of cauda epididymal spermatozoa heated at 60 degrees C for 30 min was 36%; the rate of cleavage was 24%. The rate of fertilization after microinjection of heat-treated sperm nuclei was 43%; the rate of cleavage was 26%. On the other hand, the rate of fertilization of eggs injected with sperm without heat treatment was 43%, the rate of cleavage was 29%, and there was no difference between eggs microinjected with heat-treated spermatozoa or sperm nuclei and those not heat treated. Of the viable eggs injected with heat-treated sperm, 16% developed to the 6- to 8-cell stage 72 h after injection.

Animals↗
PubMedDate not supplied

Round spermatid transfer and embryo development.

With the advent of assisted reproductive technology, pregnancy has become possible without sperm. The nucleus of the round spermatid, which contains a complete haploid set of chromosomes, can be used as a substitute for spermatozoa in animals and humans. In the mouse, round spermatids from surgically induced cryptorchid and prepubertal testes can fertilize normally and develop into normal offspring. The spermatid nucleus develops into a large pronucleus only when the oocyte is activated by artificial means, such as electrostimulation and oscillogen injection. Nuclei of mouse primary spermatocyte have been injected into oocytes and found to undergo meiosis, form an embryo and produce live young. Intracytoplasmic injection of male immature germ cells may become available as a treatment for patients with azoospermia due to maturation arrest.

Animals↗
PubMedDate not supplied

Circulating levels of inhibin in hemodialysis males.

Serum concentrations of LH, FSH, testosterone, and inhibin were measured in 65 hemodialysis male patients and 60 healthy men. In hemodialysis patients, serum levels of LH, FSH, and inhibin were significantly elevated compared to the controls (p < 0.001). However, serum testosterone level was significantly reduced in hemodialysis males (p < 0.01). Neither serum LH nor FSH correlated with inhibin in the control and hemodialysis males. In hemodialysis patients, serum inhibin showed a positive correlation with serum creatinine (p < 0.05). It would appear that an elevated level of serum inhibin is caused by a decreased metabolic clearance rate or testicular dysfunction due to chronic renal failure, and indicates the abnormality of hypothalamic-pituitary-testicular axis leading to hypergonadotropic hypogonadism in hemodialysis males.

Adult↗