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Biomedical subjects

M Takeyama

Publications and source records attributed to M Takeyama.

At least 163 records · Page 9Linked to original sources
PubMed1986

A case of nontraumatic clostridial gas gangrene occurring in a patient with colon adenocarcinoma, liver cirrhosis, and diabetes mellitus.

An autopsy case of clostridial gas gangrene occurring in a 54-year-old man with colon adenocarcinoma, liver cirrhosis, and diabetes mellitus is reported. The patient died 4 days after the onset of symptoms with episodes of vomiting and abdominal pain. Gangrene of both hips and perineum, hemolysis, renal failure, and disseminated intravascular coagulation were the dominant clinical features. Clostridium septicum was isolated from the subcutaneous tissue fluid. Adenocarcinoma of the ascending colon with ulceration found at autopsy was supposed to be an entry of the organism. Histologically, lesions of subcutaneous tissue and muscles were characterized by the absence of inflammatory infiltrates in spite of extensive necrosis. A summary of 35 cases of gas gangrene hospitalized to the Osaka University Hospital for the past 16 years indicates that clostridial gas gangrene patients with underlying diseases such as malignant neoplasm, diabetes, liver cirrhosis or immunodeficiency have a relatively poor prognosis.

Adenocarcinoma↗
PubMed1986

Stimulatory effect of prolactin on luteinizing hormone-induced testicular 5 alpha-reductase activity in hypophysectomized adult rats.

Two pituitaries from 7-week-old female rats were grafted under the capsule of the left kidney of 50-day-old male rat to induce hyperprolactinemia. All of the pituitary-grafted and sham-operated rats were hypophysectomized at 56 days of age. The hypophysectomized rats in groups of 4 were given daily sc injections of saline or 9 micrograms NIADDK-ovine-(o)LH-23 for 4 and 5 days starting from days 58 and 70, respectively (short and long term hypophysectomized groups). The metabolism of [3H]progesterone or [14C]androstenedione by testicular homogenates, concentrations of testosterone and 5 alpha-androgens (androsterone plus 5 alpha-androstane-3 alpha, 17 beta-diol) in the serum and testes, and testicular LH receptors were estimated. Hypophysectomy caused significant decreases in testicular enzyme activities per gram of tissue, androgen production, and testicular LH receptors. In the testes of hypophysectomized rats, LH treatment significantly stimulated 5 alpha-reductase and 17-hydroxylase activities. Although pituitary grafts alone showed little or no effect on these testicular enzyme activities, hyperprolactinemia induced by the grafts markedly enhanced the LH-stimulated 5 alpha-reductase activity in both groups, especially in the long term hypophysectomized group. Therefore, androsterone and 5 alpha-androstane-3 alpha,17 beta-diol were shown to be the major C19-steroid products (immature type of testicular androgen production) in the LH- and PRL-stimulated testes of long term hypophysectomized adult rats. On the other hand, hyperprolactinemia was associated with a significant inhibition and a slight increase of the LH-stimulated 17-hydroxylase activities in the short and long term hypophysectomized groups, respectively. This difference can be attributed to both a PRL-induced increase in testicular LH receptors and a PRL-induced inhibition of 17-hydroxylase via a postreceptor mechanism(s). The present findings demonstrate for the first time that PRL directly stimulates LH-induced 5 alpha-reductase activity in the testes. It appears that PRL may play a role in the increased production of 5 alpha-C19-steroids and the parallel decrease of testosterone production in immature rat testes.

17-Hydroxysteroid Dehydrogenases↗
PubMed1985

Hormonal regulation of activities of 4-ene-5 beta- and 5 alpha-reductases and 17 beta-hydroxy-dehydrogenase in immature golden hamster testis.

We have reported [1-3] in immature golden hamster testis that 5 beta-reductase is localized in the tubular nongerm cells, while 5 alpha-reductase is present in the interstitial tissue and that the 17 beta-hydroxy-dehydrogenase activity is found predominantly in the tubular nongerm cells. Hormonal regulation of these enzyme activities was examined in the present study. Male golden hamsters were hypophysectomized on day 22 after birth. The hypophysectomized hamsters in groups of 3-8 were injected daily with 10 micrograms NIH-LH-S19, 50 micrograms NIAMD-Rat-FSH-B-1, 8 or 16 micrograms NIAMD-oFSH-13, 8 micrograms NIAMD-oFSH-13 plus 5 or 10 micrograms NIH-LH-S19, 1 mg testosterone propionate or saline for 5 days starting from day 23. Testicular homogenates of the treated hamsters and intact hamsters on day 28 were incubated with [14C]4-androstene-3,17-dione and NADPH, and enzyme activity (nmol/testes/h) was estimated. The activities of 5 beta- and 5 alpha-reductases and 17 beta-hydroxy-dehydrogenase decreased significantly 6 days after hypophysectomy. In the hypophysectomized hamster testis, a distinct response to FSH but not to LH in the activities of 5 beta-reductase and 17 beta-hydroxy-dehydrogenase was found. The injection of LH in addition to FSH showed no significant additive effects on these enzyme activities. The 5 alpha-reductase activity was stimulated significantly by LH plus FSH but not by LH alone, FSH alone or androgen. These results show that 5 beta-reduction of 4-ene-3-ketosteroids takes place in the Sertoli cells under the influence of FSH while 5 alpha-reduction occurs in the interstitial cells under the influence of LH and FSH in immature hamster testis.

17-Hydroxysteroid Dehydrogenases↗
PubMed1985

17 alpha-oxidoreductase activity in kidneys of male and female mice of various ages.

Male and female mice at 0-120 days of age were used. Homogenates of kidneys were incubated with [14C]4-androstene-3,17-dione, and 17 alpha-oxidoreductase activity per g tissue was examined. The activities of 17 alpha-oxidoreductase in the kidneys of both sexes increased markedly with age during sexual development by up to 150-fold and reached the maximum values (2700 and 1500 nmol/g/h in male and female kidneys, respectively) at 60 days of age. In the adult male mouse kidney, the activity in isolated cortex fractions was 14 times as high as the activity in isolated medulla fractions; in the medulla fractions renal tubules from the cortex accounted for 3-15% of the total tissue. Furthermore, histochemical examination showed the activity present only in the cortex, at which much higher levels in the tubules than in the glomerulus. Activity at 35-120 days of age was significantly higher in male kidneys than in female kidneys. The difference appears to be induced by testicular androgens during sexual development, since neonatal castration in males resulted in decreases of activity to levels similar to those in female kidneys. However, castration at 60 days of age showed no significant effect on the activity. The present results show that the activity per g tissue of 17 alpha-oxidoreductase in the mouse kidney increases markedly with age, and that the activity is largely confined to the renal tubules of the cortex.

17-Hydroxysteroid Dehydrogenases↗
PubMed1985

Effects of hyperprolactinemia on activities of 17-hydroxylase, 17 beta-ol-dehydrogenase and 5 alpha-reductase in neonatally grafted and host testes in mice.

Male and female (WB X C57BL/6)F1 hybrid mice were used. Two pituitaries from 60-80-day-old female mice were grafted under the capsule of the left kidney of 60-80-day-old male mice. One week after grafting, 2 testes from neonatal mice were grafted under the capsule of the right kidney of the grafted mice and 70-90-day-old intact male mice. The grafted and host testes, in groups of 10-26, were removed 15, 30, 40, 60 and 120 days after transplantation of the neonatal testes. Testicular homogenates were incubated with [3H]progesterone or [14C]4-androstene-3,17-dione, and enzyme activities per g tissue were estimated. Significantly elevated prolactin levels, slightly lower LH levels and normal testosterone levels were found in the mice with pituitary grafts, compared with those in the mice without pituitary grafts. Activities of 17-hydroxylase and 17 beta-ol-dehydrogenase increased clearly with age in the grafted testes in the mice without pituitary grafts, though the increases were inhibited significantly by the pituitary grafts. However, the pituitary grafts had no significant effect on activities of 17-hydroxylase and 17 beta-ol-dehydrogenase in the host testes under similar gonadotrophic stimulation. 5 alpha-Reductase activities in the grafted and host testes were unaffected by the pituitary grafts. These results show that hyperprolactinemia may directly inhibit increases in activities of 17-hydroxylase and 17 beta-ol-dehydrogenase with testicular age in neonatally grafted testes in mice.

17-Hydroxysteroid Dehydrogenases↗
PubMed1984

Changes with age in activities of 4-ene-5 alpha-reductase, 17 beta-ol-dehydrogenase and 17-hydroxylase in normal and neonatally grafted mouse testes.

Male and female (WB X C57BL/6)F1 hybrid mice of various ages were used. Two testes from mice at day 0 after birth were grafted under the capsule of the right kidney of male, female and castrated male mice at 80-100 days of age, and the grafted testes in groups of 12-24 were removed 15-120 days after grafting. Normal testes of various ages were also used. Testicular homogenates were incubated with [3H]progesterone or [14C]4-androstene-3,17-dione, and enzyme activities per g tissue were estimated. Activities of 17-hydroxylase and 17 beta-ol-dehydrogenase increased significantly with age in the normal testes and in the grafted testes in the males, females and castrated males; the most conspicuous increases in activities of 17-hydroxylase and 17 beta-ol-dehydrogenase were found, respectively, from 15 days of age to 30 days and from 30 days to 40 days. In contrast, 5 alpha-reductase activity was the highest at 30 days of age, moderately high at 15 and 40 days and very low at 60 and 120 days in the normal testes as well as in all grafted testes examined under various endocrine conditions, though the peak value at 30 days was significantly higher in the normal testes than in the grafted ones. These results seem to indicate that changes with age in 5 alpha-reductase activity relative to other enzyme activities in mouse testes are at least in part an autonomous process related to the period of gonadotropin stimulation or age of the Leydig cells.

17-Hydroxysteroid Dehydrogenases↗
PubMed1984

Deficiency of 5 alpha-steroid formation in guinea pig ovaries compared with immature rat and hamster ovaries.

Activities of 4-ene-5 alpha-reductase and the metabolism of progesterone were estimated in ovaries of guinea pigs, rats and golden hamsters. In the ovaries of 20-90-day old guinea pigs, the major C21-17-hydroxysteroids and C19-steroids formed from progesterone were 4-ene-3-ketosteroids, such as 17-hydroxy-4-pregnene-3,20-dione and 4-androstene-3,17-dione, and 5 alpha-C21-17-hydroxysteroids and 5 alpha-C19-steroids were not produced. In contrast, the major steroids formed by the ovaries of immature rats and immature hamsters were 5 alpha-steroids, such as 3 alpha, 17-dihydroxy-5 alpha-pregnan-20-one and androsterone, and no 4-ene-3-ketosteroids were found. The 5 alpha-reductase activity (nmol/g tissue/h) in the ovaries of immature hamsters was approx 150 times higher than those in the ovaries of guinea pigs of different ages. In contrast to rats and hamsters, the ovaries of immature guinea pigs do not form a significant amount of 5 alpha-androgens.

Aging↗
PubMed1984

5 Alpha- and 5 beta-reductases for 4-ene-3-ketosteroids and 17 beta-ol-dehydrogenase in epididymis and testis of golden hamster during sexual development.

Homogenates of the epididymis, testis and seminal vesicle from 15, 25, 35 and 60-day old golden hamsters were incubated with [3H]4-androstene-3,17-dione and NADPH and enzyme activity was estimated. In the testis, activities of 5 alpha- and 5 beta-reductases were the highest (32 +/- 4 and 68 +/- 13 (SD) nmol/100 mg protein/h, respectively) at 25 days of age, moderately high at 35 days and very low (1-3 and 5-6, nmol/100 mg protein/h, respectively) at 15 and 60 days. In the epididymis, 5 alpha-reductase activities increased with age during sexual development by up to 50-fold and reached the maximum value (40 +/- 11 nmol/100 mg protein/h) at 60 days. The 5 alpha-reductase activities in the seminal vesicle were found to be relatively low (0.5-1 nmol/100 mg protein/h), compared with those in the epididymis and testis. Activities of 5 beta-reductase in the epididymis and seminal vesicle were very low (0.1-0.5 nmol/100 mg protein/h) at all ages. These results indicate the existence of a marked, but transient, increase in 5 alpha- and 5 beta-reductase activities during immature period in the testis of golden hamster. In the epididymis, however, 5 alpha-reductase activity increases with age during sexual maturation, while 5 beta-reductase activity is almost undetectable at all ages.

17-Hydroxysteroid Dehydrogenases↗
PubMed1984

[Breast cancer--topics from basic research].

The measurement of estrogen and progesterone receptors in human breast cancer provides useful markers for predicting response to endocrine therapy. In human breast cancer, about 90% of unresponsive tumors and 60-80% of tumors responsive to endocrine therapy can be predicted by receptor measurement. Hormone-dependency of breast cancer easily disappears, and endocrine therapy for hormone-dependent cancer markedly encourages disappearance. Since very useful non-steroidal antiestrogens have been synthesized recently, the usefulness of drug-based endocrine therapy for breast cancer has become more important compared with brought about by surgical therapy. To improve the effectiveness of endocrine therapy for hormone-dependent cancer, the proliferation of hormone-independent cancer cells developing from hormone-dependent cancer cells during endocrine therapy should be inhibited. For inhibition, chemotherapy combined with the endocrine therapy and adjuvant endocrine therapy seem to be useful methods for the future.

Animals↗
PubMed1983

Effect of synthetic chicken vasoactive intestinal peptide on pancreatic blood flow and on exocrine and endocrine secretions of the pancreas in dogs.

This study was undertaken to determine the effect of synthetic chicken vasoactive intestinal peptide (VIP) on pancreatic blood flow, exocrine and endocrine secretions of the pancreas, and biliary secretion in dogs. The effect of synthetic chicken VIP on pancreatic blood flow and systemic arterial pressure was identical to that of natural chicken VIP in dogs. The present study demonstrated that synthetic chicken VIP induces significant increases in pancreatic blood flow, pancreaticobiliary secretion, and blood levels of insulin and glucose in dogs. Both the volume of pancreatic juice and blood levels of insulin were increased in consonance with the increase of pancreatic blood flow. This study suggests that the stimulatory effects of synthetic chicken VIP on exocrine and endocrine secretions of the pancreas may be related to the increased pancreatic blood flow elicited by synthetic chicken VIP.

Animals↗
PubMed1983

Hormonal regulation of activities of 4-ene-5 beta and 5 alpha-reductases and 17 beta-ol-dehydrogenase in immature golden hamster ovary.

Diethylstilbestrol (DES) pellets were implanted in female golden hamsters on day 22 after birth. Hamsters with or without the DES pellet were hypophysectomized on day 23. Starting from day 26, the hypophysectomized hamsters were injected daily with 2.3-40 micrograms NIH-LH-S19, 6 or 18 micrograms NIAMD-oFSH-13, 50 micrograms NIAMD-Rat-FSH-B-1, or saline for 3 days. Ovarian homogenates from these hamsters on day 29 were incubated with [14C]-4-androstene-3,17-dione and enzyme activity (nmol/g/h) was estimated. The 5 alpha- and 5 beta-reductase activities decreased significantly following hypophysectomy. In the hypophysectomized hamster ovary, a distinct response to LH but not to FSH or DES in the 5 alpha-reductase activity was found. On the other hand, the 17 beta-ol-dehydrogenase activity was stimulated by FSH but not by LH or DES. The 5 beta-reductase activity was stimulated by DES, FSH or 2.3 micrograms LH but not by 7-40 micrograms LH. In the DES-treated, hypophysectomized hamster ovary, LH and FSH stimulated the 5 alpha-reductase and 17 beta-ol-dehydrogenase activities, respectively, but FSH or LH treatment had no significant effect on the 5 beta-reductase activity. These results show that the 5 alpha-reductase activity is regulated by LH, while the 17 beta-ol-dehydrogenase activity is stimulated by FSH in immature golden hamster ovary. The 5 beta-reductase activity seems to be regulated predominantly by FSH but the effect of FSH is largely mediated by estrogen.

17-Hydroxysteroid Dehydrogenases↗
PubMed1983

Intratubular localization of 4-ene-5 beta-reductase and 17 beta-hydroxy-dehydrogenase in immature golden hamster testis.

We have reported [1,2] in immature golden hamster testis that 5 beta-reductase is localized in the seminiferous tubules, while 5a-reductase is present in the interstitial tissue and that the 17 beta-ol-dehydrogenase activity is found predominantly in the seminiferous tubules. In the present study, we show the intratubular localization of these enzymes. The left testis of golden hamster was irradiated with 2000R or 8000R of X-rays at 22 days of age. The hamsters were killed at 28 days of age. Homogenates of the left irradiated and right intact testes were incubated with [14C]-4-androstone-3,17-dione and NADPH, and enzyme activity was estimated. Both testes were also examined histologically. The X-irradiation of the testis resulted in an almost complete disappearance of germ cells with a significant decrease in testis weight, but the interstitial tissue and tubular nongerm cells including Sertoli cells remained almost unchanged. However, the activities of 5 beta-reductase and 17 beta-ol-dehydrogenase expressed as nmol formed/testis/h did not decrease at all. These results show that 5 beta-reductase is localized in the tubular nongerm cells including the Sertoli cells and 17 beta-ol-dehydrogenase is present in the tubular nongerm cells and interstitial tissue in immature golden hamster testis.

17-Hydroxysteroid Dehydrogenases↗
PubMed1982

A new coupling agent for composite materials: 4-methacryloxyethyl trimellitic anhydride.

Composite materials were made by sedimention of ceramic powders in methyl methacrylate which was then polymerized by gamma-irradiation. Inclusion of 4-methacryloxyethyl trimellitic anhydride (4-META) generally was found to result in an increase in Knoop hardness number, Young's modulus, and transverse strength. Most emphasis was placed on transverse strength which was found to be increased by ca. 30% by inclusion of 4-META (5 wt %) in composites made with silanated LiAlSiO4. However an abrupt decrease in strength was found for composites with greater than ca. 83 wt % silanated LiAlSiO4. This was shown by fractography to be due to increased porosity and dewetting at the higher filler contents. Fractography also indicated that inclusion of 4-META results in a more coherent polymeric matrix. Further evidence for greater coherence was obtained by showing that 4-META confers resistance to disintegration by chloroform.

Acrylates↗