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Biomedical subjects

Y Haruki

Publications and source records attributed to Y Haruki.

29 records · Page 2Linked to original sources
PubMed1980

Specific progestin binding in vitro by anterior pituitary and brain tissues of male rats.

Using a highly potent synthetic-progestin, R5020 (17 alpha, 21-dimethyl-19-nor-4, 9-pregnadiene-3, 20-dione), the characterization of progestin binding components was attempted in cytosols from the anterior pituitary and various brain tissues of castrated or castrated-adrenalectomized male rats. In both types of operated rats, estrogen administration increased the number of binding sites of R5020 in the anterior pituitary and hypothalamus-preoptic area, but not in the cerebral cortex, amygdala-hippocampus nor in the cerebellum. After incubation of the anterior pituitary cytosol with [3H]-R5020 with or without various unlabeled steroids, a specific progestin binding was found in the 7-8S region with a binding capacity of 250 fmoles/mg protein and equilibrium dissociation constant of 8 nM. A specific progestin binding was also found in the cytosol from hypothalamus-preoptic area sedimenting in the 7S region with a binding capacity of 150 fmoles/mg protein and a dissociation constant of 6 nM. Specific binding components in these tissues were heat-labile and protein in nature. Little or no 7S binding was found in the other brain tissues. Although 4-5S binding in the cerebral cortex and 4S bind ng in the amygdala-hippocampus and cerebellum were found, binding specificity in those tissues was low. It was concluded that the pituitary gland and hypothalamus-preoptic area of male rats contained progestin receptor in their cytoplasms.

Adrenal Glands↗
PubMed1980

Estrogen receptor in rat thymus cytosol.

Estrogen binding components were characterized in cytosol fractions from the lymphatic tissues of castrated rats. Sucrose gradient analysis revealed specific binding of tritiated estrogen in the thymus. The binding was highly specific since it was easily displaced by unlabeled estrogen, but not by the non-estrogenic steroids used. In thymus cytosols from both males and females, the equilibrium dissociation constant of estrogen binding was--0.3 nM and the saturation binding was 6 fmols/mg of protein. Enzyme- and heat-experiments demonstrated a specific estrogen binder in thymic cytosol which was heat-labile and protein in nature. It was concluded that the rat thymus contains on estrogen receptor which is in part protein and heat-labile.

Animals↗
PubMed1979

Estrogen receptor in the thymus of the castrated mice.

Sucrose density gradient ultracentrifugation and dextran-coated charcoal adsorption permitted us to characterize the estrogen-binding proteins in cytosols obtained from the thymus, spleen and mesenteric lymph node of the castrated male and female mice of C57BL strain. The thymic cytosol from both sexes incubated with 3H-estradiol-17 beta in the presence of excess unlabeled steroids showed a specific estrogenbinding 4 S protein with its binding capacity of 10(-14) moles/mg protein for males and 4 x 10(-15) moles/mg protein for females, respectively. The dissociation constant was of 4 x 10(-10) M for males and 3 x 10(-10) M for females, respectively. No specific binding was, however, found in the cytosols of the spleen and mesenteric lymph node. Steroid analysis by thin-layer chromatography of the thymic cytosols after incubation of them with 3H-estradiol-17 beta showed that a fair amount (around 60%) of radioactivity was from the undegradated radioactive steroid still bound to 4 S binder in both sexes. Enzyme study and heat experiment revealed that the estrogen specific 4 S binding component in the thymic cytosols bears at least protein in nature and is of heat-labile nature. These results strongly suggest that the thymus of the castrated mice contain a specific estrogen receptor, the nature of which is in part protein and heat-labile.

Animals↗
PubMed1979

Progestin binding in vitro by the brain cell nuclei of ovariectomized oestrogen-primed rats.

The uptake and binding of 17 alpha, 21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione, a synthetic progestin, by the hypothalamus and cerebral cortex of ovariectomized oestrogen-primed rats was examined in vitro. Uptake of this steroid by the medial basal hypothalamus was higher than that by the remaining hypothalamus and cerebral cortex. The component in the cytosol from whole hypothalami which bound the radioactive progestin sedimented in the 7S region when centrifuged in a sucrose density gradient. The tritiated progestin was displaced by incubation with non-radioactive progestin or progesterone but not by oestradiol-17 beta, corticosterone or 5 alpha-dihydrotestosterone (1 mumol/l). No 7S binding component was detected in a similar preparation from the cerebral cortex. The nuclear fraction from whole hypothalami extracted by KCl (0.4 mol/l) contained a progestin-binding complex which sedimented at 9S and which was heat-labile and protein in nature. It was concluded that the hypothalamus of ovariectomized oestrogen-primed rats contains progestin-binding material in the cytoplasm and progestin, bound to such material, is transported from the cytoplasm to the nucleus.

Animals↗
PubMed1978

Accumulation and binding of 3H-estradiol-17beta by lymphoid tissues of castrated mice.

The in vivo uptake of 3H-estradiol-17beta by the various lymphoid tissues, fat tissue, skeletal muscle and circulating blood of castrated male and female mice of C57BL strain was studied after an intravenous injection of the hormone. In both sexes the highest uptake was by the bone marrow and fat tissue, followed by the spleen, thymus and mesenteric lymph node. The lowest was by the muscle and the blood serum. The lymphoid tissues in the female took up a slightly more amount of radioactivity than those in the male until 1 hr after the injection, but thereafter the uptake was at almost the same level between both sexes. The lymphoid tissues showed a relative and long-term retention of the radioactivity, as compared with that in the muscle and blood serum. The binding of 3H-estradiol-17beta by the lymphoid tissue cytosol and their binding specificity for the hormone were examined in vitro by Sephadex G-100 column analysis. All the tissue cytosols tested contained estradiol-binding component(-s). Among those the thymic cytosol showed to contain the component(-s) which is fairly specific to this hormone. These results suggest that there is a relatively high uptake and retention of estrogen in the lymphoid tissues in which it is bound to cytoplasmic binding component(-s).

Adipose Tissue↗
PubMed1977

Further evidence of the presence of progesterone-binding proteins in female rat hypothalamus.

Utilizing techniques of Sephadex G-200 column chromatography, sucrose density gradient ultracentrifugation and dextran-coated charcoal adsorption, the characterization of progesterone-binding proteins was attempted in cytosols obtained from the medial basal hypothalamus including the median eminence, the remaining hypothalamus and the cerebral cortex of ovariectomized estrogen-primed rats. Ater incubation of the medial basal hypothalamic cytosol with 3H-progesterone in the absence or in the presence of various unlabeled steroids, a specific progesterone-binding protein was found in the 7 S region with its binding capacity of approximately 2 X 10(14) moles per mg protein and dissociation constant of approximately 6 X 10(-9) M. No specific binding was, however, found in the remaining hypothalamus and the cerebral cortex.

Animals↗
PubMedDate not supplied

Internet medical usage in Japan: current situation and issues.

Internet use by physicians and patients has become very popular in Japan. Fifty percent of physicians use the Internet to search for medical and other information. Over the past year, 22% of patients used the Internet to obtain medical information. Because there are no restrictions within Japan on using Web sites to advertise medical treatment, information can be freely sent out, and over the past two or three years this practice has increased dramatically. Internet medical information provides information about illnesses and medications, and it helps improve the quality of life of patients and families. Yet, depending on the content of the information provided and the way this information is used, there is a potential negative side as well. On principle, users are responsible for the way information is used, but there is a need for information providers to consider users safety and to make the information effective for use. Because there is no absolute standard for evaluating the value of medical information, it is necessary to establish a system that opens a dialogue with society and that continuously accumulates high-quality information through the collection of various evaluations, rather than rely on an established authority. For industries and organizations related to commercial pursuits, in particular, it is most effective to establish their own codes for ethical conduct, rather than rely on governmental regulations. At the same time, it is important to have a confirmation function to evaluate how goals set by the outside are being implemented. Aiming at establishing a framework for the Internet medical usage, the Japan Internet Medical Association (JIMA) was founded in 1998 by medical professionals, lawyers, researchers, consumer representatives, patients and their families. We propose a system that would combine feedback from users, who would take on the role of evaluators of the implementation of an ethical code, with a displayed mark that verifies the identity of the Web site. Objective evaluation of information is needed to ensure that users have the power to make choices. Medical experts or patient and family groups would assist in this task. The development of medical care will be promoted through patients and physicians working together in the accumulation of shared resources for good medical care information.

Certification↗
PubMedDate not supplied

Health and welfare data on optical memory cards in Isehara city.

An off-line network system of health and welfare for elderly people using optical memory cards has been established in Isehara city (Japan) since 1991. 2775 citizens have the cards and 24 offices have the terminals. It covers almost one third of people aged over 65 in Isehara city and almost all of the offices concerned with their health and welfare. About a half of holders use optical memory cards every time they visit these offices. The optical memory card holds data including basic data for health and welfare, health check data over 5 years, medical images with scripts and history of welfare services. All the data are used for medical care, health consultation and management of health and welfare services. A card can hold health and welfare data for a lifetime, and it is easy to expand the system. It has been a good experience for us, because the optical memory card system needs co-operation among citizens, medical association and local government, and the experience will help us to expand the system in the future.

Aged↗