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Biomedical subjects

Y Takeo

Publications and source records attributed to Y Takeo.

At least 19 recordsLinked to original sources
PubMed1994

Efficacy of disinfectants against biofilm cells of Pseudomonas aeruginosa.

The effect of disinfectants on biofilm cells of Pseudomonas aeruginosa were evaluated. Biofilm cells of P. aeruginosa were eradicated by 0.4 to 0.5% chlorhexidine and 2% glutaral within 1 min, by 0.3% chlorhexidine, 0.5% benzalkonium chloride, 0.1% sodium hypochlorite, and 0.1% titratable I2 providone-iodine within 10 min, and by 0.2% chlorhexidine, 0.1% benzalkonium chloride, and 0.01% sodium hypochlorite within 30 min. However, 0.1% chlorhexidine and 0.1 to 0.5% alkyldiaminoethyl glycine were ineffective for eradication even after 1 h. Eradication of biofilm cells of P. aeruginosa by disinfectants required much longer time than that of planktonic cells in suspensions. The bactericidal effect of disinfectants against biofilm cells was found to be considerably enhanced by increasing the concentrations of the disinfectants.

Disinfectants↗
PubMed1989

[Spontaneous fracture and osteoporosis following renal transplantation].

The recovery of renal osteodystrophy can be achieved by renal transplantation but secondary bone changes appear after transplantation due to immunological reaction and immunosuppressive drugs. Very few cases of spontaneous fracture and osteoporosis have been documented among patients after renal transplantation. This was investigated from roentgenologic, histologic, biochemical, and immunological viewpoints in 180 transplant patients treated at Hyogo Prefectural Nishinomiya Hospital. The following conclusions were obtained. (1) Among 180 patients, spontaneous fractures occurred in 22%. (2) Pathogenesis of the fracture of transplant patient was found to be related to steroid induced osteoporosis and not to renal osteodystrophy. (3) There was no relation between spontaneous fracture and OKT4/OKT8 ratio.

Adolescent↗
PubMed1986

Ultrastructural evidence for estradiol synthesis in the ovary of persistent-estrous rats exposed to continuous illumination.

The relation between sex hormone levels in blood and ultrastructural changes of ovarian follicles was examined in persistent-estrous rats exposed to continuous illumination (LL) for 100 days. Plasma LH showed a tonic level secretory pattern, and circulating estradiol and estrone concentrations were relatively high, while both levels of FSH and progesterone were low. Various stages of growing and degenerating follicles were observed in the ovary of the LL-exposed rats. The early stage of antral follicle did not seem to possess the ability of steroidogenesis. Theca cells around mature antral follicles contained prominent Golgi apparatuses, plenty of smooth endoplasmic reticulum (ER), abundant free ribosomes and many round-mitochondria. A few newly formed lipid droplets were seen in some of theca cells. Granulosa cells contained much distended rough ER, well-developed mitochondria, several lipid droplets and microfilaments. The theca cells of abnormal follicles with hyperplastic and infolded layers of granulosa cells contained many lipid droplets. However, the development of the smooth ER became hindered with increasing lipid droplets in the theca cell. On the other hand, granulosa cells of abnormal follicles contained greater numbers of lipid droplets than those of antral mature follicles, and were equipped with well-developed cytoplasmic organelles as were those of mature antral follicles. Theca interna cells of abnormal follicles may be more involved in the secretion of androgen, which has already been accumulated in the lipid droplets, than the cells involved in the active synthesis of the hormone, while the granulosa cells may convert its androgen to estrogen. The present findings suggest that both follicles of mature and abnormal types in the LL-exposed rat retain enough capacity of estradiol production and participate in the continued elevation of circulating estradiol, probably resulting in the stimulation of the theca cells by the tonic level of LH and of the granulosa cells by the levels of FSH, which are lower than the basal values during the normal 4-day estrous cycle.

Animals↗
PubMed1984

Influence of continuous illumination on estrous cycle of rats: time course of changes in levels of gonadotropins and ovarian steroids until occurrence of persistent estrus.

Plasma concentrations of LH, FSH, 17 beta-estradiol, estrone and progesterone were determined chronologically by radioimmunoassays in two groups of adult female rats exposed to continuous illumination (LL). Group 1 rats showing vaginal estrous cycles were sacrificed at 3- to 6-hour intervals during late proestrus through early estrus of the first 5 cycles after exposure to LL. Group 2 animals which displayed persistent vaginal estrus in an early period of exposure to LL were killed on the 2nd, 3rd, 4th, 5th and 7th days of vaginal estrus. In Group 1 rats, surges of the hormones, except estrone, took place in all the 5 cycles. The occurrence of peak hormone levels in each cycle was invariably delayed after transfer of animals to LL. According to regression analyses, the lengths of secretion cycles of LH, FSH, 17 beta-estradiol and progesterone in rats under LL were 100.89, 100.46, 101.14 and 101.06 h, respectively. Elevation of 17 beta-estradiol levels was observed prior to the LH surge, and peaks of progesterone and FSH occurred following it. However, the secretion patterns of these hormones appear to be disrupted with length of exposure to LL. In group 2 rats, the mean concentration of LH during persistent estrus was approximately similar to that on the morning of the days of proestrus of the 4-day cycles of rats placed under an alternating 12-hour light-dark regimen (LD), whereas the mean FSH concentration was continuously low. While the concentrations of 17 beta-estradiol and estrone in persistent-estrous rats were elevated, progesterone levels remained low.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Dissociation of estrous cycle and activity rhythm in rats.

When rats were kept in continuous light there was a time-lag between the onset of activity arrhythmia and that of persistent estrus. When animals showing both arrhythmias in continuous light were kept under a LD 21:3 photoperiod, the activity rhythm returned to normal but the estrous cycle did not.

Activity Cycles↗
PubMed1983

Clearance of materials from breakdown of uterine collagen in mice during postpartum involution.

The collagen content of the mouse uterus increases during pregnancy and rapidly decreases to the level of nulliparous mice within a few days post partum. Most of the hydroxyproline in the uterine collagen had disappeared by day 3 post partum. During postpartum involution the hydroxyproline concentration in both the serum and blood clot was not higher than in nulliparous mice. The total hydroxyproline content in the liver, spleen and thymus was significantly increased during postpartum involution. These results indicate that materials derived from the breakdown of uterine collagen are rapidly removed from the blood stream by reticuloendothelial clearance.

Animals↗
PubMed1982

Development of Harderian gland during metamorphosis in anurans.

Development of Harderian gland of larvae of Rana japonica, Bufo bufo japonicus, and Xenopus laevis was studied. In the adult animals, well-developed Harderian glands were invariably present in the orbit. In Rana and Bufo, the gland first appeared at late prometamorphic stage and in Xenopus it appeared around climax stage. In thyroidectomized tadpoles of Bufo and Rana, the Harderian gland was induced by thyroxine. In hypophysectomized tadpoles of Bufo the gland developed when they were treated with thyroxine or TSH.

Animals↗
PubMed1982

Direct effect of melatonin on the accessory sexual organs in pinealectomized male rats kept in constant darkness.

Pinealectomized and sham-pinealectomized male rats were subcutaneously implanted with 2 cm silicone elastomer capsules filled with testosterone or dihydrotestosterone (DHT) and placed in constant darkness (DD) for 50 days. The data revealed that the sham-pinealectomized group treated with testosterone differed from the pinealectomized group, having lower weights of accessory sexual organs and levator ani muscle. Pinealectomy had no effect on organ and muscle weights of DHT-treated animals. Exposure of male rats to DD resulted in a marked decrease in weights of ventral prostate, seminal vesicle, coagulating gland and levator ani muscle and a decrease in plasma DHT levels. However there was no significant reduction in plasma LH, FSH or testosterone. Pinealectomy of the rats exposed to DD resulted in restoration of both DHT levels and accessory sex organ weights. Melatonin implants in pinealectomized males led to an increase in both testosterone and DHT levels, accompanied by a decrease in sexual organ weights. The data indicate that the anti-gonadal effect of the pineal gland cannot be completely mediated by melatonin and that melatonin and some unknown factors can act at the tissue level to reduce the size and function of the affected sexual organs.

Animals↗
PubMed1981

Influences of some endocrine glands and of hormone replacement on the porphyrins of the Harderian glands of mice.

There are marked sex differences in the Harderian gland of the C3H/He strain of mice. Female (but not male) glands contain large amounts of porphyrin, which are readily visible as solid depositions within the lumina. The histology and porphyrin content of the Harderian gland were examined in intact and in pregnant mice and in mice subjected to combinations of adrenalectomy, gonadectomy and administration of sex steroid hormones. In male mice, castration approximately doubled the amount of porphyrin in the Harderian gland. Castration plus adrenalectomy increased the levels over 30-fold, to levels similar to those found in female mice, although adrenalectomy alone produced no significant effect. Administration of testosterone to the male mice which had been castrated and adrenalectomized prevented the increases while progesterone treatment produced further increases in porphyrins. In intact females, the amount of porphyrin varied with the phase of the oestrous cycle; being lowest during metoestrus and highest during dioestrus. In ovariectomized-adrenalectomized females, the effects of administered sex hormones on the amount of porphyrin in the gland were the same as in males. In pregnant mice, the level was no significantly different from that in intact oestrous animals.

Adrenalectomy↗
PubMed1976

Influence of monoamine oxidase inhibitor on the induction of persistent estrus by androgen in the rat.

Effect of monoamine oxidase inhibitor (MAOI) on the induction of persistent estrus by testosterone propionate (TP) was studied in Wistar strain female rats. Daily treatment with MAOI for the 1st 10 days of life accelerated the occurrence of persistent estrus in rats given TP at 8 days of age. The onset of persistent estrus occurred at 57.3+/2.0 days of age in these animals compared to 92.6+/5.5 days in saline-treated controls. The contribution of hypothalamic monoamines to the induction of persistent estrus by TP treatment in neonatal rats will be discussed.

Age Factors↗
PubMed1976

Recurrence of estrous cycles in the light-induced persistent estrous rats by reserpine.

Effect of continuous illumination (LL) on ovarian functions was compared at various ages between the rats exposed to LL from 70 days of age (LL-70) and exposed to LL from the day of birth (LL-0). LL-0 rats retained corpora lutea in their ovaries in higher incidence than LL-70 rats. Effect of reserpine on the restoration of cyclicity was studied in LL-0 and LL-70 rats shortly after they became persistent-estrous. LL-0 rats restored cyclicity in higher incidence than in LL-70 rats.

Animals↗
PubMed1975

Pinealectomy and sexual rhythm in female rats.

The role of the pineal gland in inducing and maintaining the persistent estrus of rats exposed to continuous illumination was examined. Under the cyclic illumination, the pinealectomy or sham-operation revealed no effect on the estrous cycle, although weights of the ovaries, adrenals and hypophysis were slightly but definitely greater in the pinealectomized animals. In rats exposed to the continous illumination immediately after pinealectomy or sham-operation, both groups exhibited the persistent estrous states soon after the change of lighting condition. In these rats, neither the degree of persistent estrus nor the organ weights a autopsy showed any significant difference between the groups. Moreover, the pinealectomy could not alter the incidence of estrous in persistent estrous rats which had been established already by the continuous illumination.

Animals↗
PubMed1975

Correlation between sexual maturation and induction of persistent estrus by continuous illumination.

The rats brought up under continuous illumination from the neonatal day persist in the rhythmic estrous cycle for long time and do not easily reveal so-called continuous vaginal estrus. On the contrary, immature rats at about 30 days of age show the persistent estrus soon after exposure to continuous illumination as well as adult rats. The purpose of this paper was to examine the relation of the age placed under continuous illumination and the time required to reach the persistent estrus. As the results, it was found that the younger rats need proportionally the longer time to reach the persistent estrus; the rats which were transferred into continuously illuminated environment at 0 (group A), 5 (group B), 10 (group C), 15-16 (group D) and 30 (group E) days of age required a mean time of 132.1 +/- 8.4, 126.8 +/- 8.9, 89.7 +/- 6.2, 91.5 +/- 3.8 and 70.3 +/- 3.0 days after birth to reach the persistent estrus, respectively. In the present data, a significant difference was seen between group B and C. Though all rats were killed after the same length of persistently estrous periods, actual endocrine level appeared to differ among the groups; the rats required longer time to reach the persistent estrus had smaller ovaries and adrenals.

Age Factors↗
PubMed1975

Inhibitory effect of 5-hydroxytryptophane on the induction of persistent estrus by androgen in the rat.

Effects of monoamines or its precursors on the induction of persistent estrus by testosterone propionate (T.P.) were studied in Wistar strain female rats. Daily treatment with 5-hydroxytryptophane (5-HTP) for the first 10 days of life delayed the occurrence of persistent estrus in rats given T.P. at 4 days of age. The onset of persistent estrus occurred in this group of animals at 67.1+/-2.5 days of age compared with 45.1+/-1.4 days of age for the saline treated control group. The role of hypothalamic monoamines in contributing to the induction of persistent estrus by T.P. treatment of neonatal rats is discussed.

5-Hydroxytryptophan↗