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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 1,441 records · Page 80Linked to original sources
PubMed1982

Effect of microphase separated structure of polystyrene/polyamine graft copolymer on adhering rat platelets in vitro.

Rat platelet adhesion on microphase separated surface of polystyrene/polyamine graft copolymers (SA copolymers) was investigated. Shapes of adhering platelet were very much changeable in response to the mode of microphase separation of SA copolymer surfaces. We assume that the microphase separated structure of SA copolyer may regulate the shape change of platelet through its effect on a redistribution of proteins and/or lipids present at the plasma membrane of platelets.

Animals↗
PubMed1982

Nine cases with postintubation granuloma of the larynx.

Nine cases with postintubation granuloma of the larynx were observed during the last 7 years at our infirmary. The age ranged from 30 to 58 years, the average being 45 years. Seven were females and two were males. Granuloma of the larynx was found in the posterior one thirds of the vocal cord in eight cases out of the nine. Surgical removal of granulomas was performed in eight cases under laryngomicrosurgery, whereas other one case responded to conservative treatment.

Adult↗
PubMed1982

Steroidogenesis in vitro by human ovarian follicles during the process of atresia.

Slices of each of the six antral follicles at different stages of atresia isolated from ovaries of six patients with or without pretreatment with HCG before laparotomy, were incubated with [1-14C] acetate. Incorporation into progestins, androgens and oestrogens was assessed by the reverse dilution technique with recrystallization to constant specific activity. The greatest incorporation into androstenedione without any incorporation into progesterone was commonly observed throughout the morphologically defined three stages of atresia. In the first stage atretic follicles, characterized by coexistence of normally developed thecal cells with degenerating granulosa cells, a minute incorporation into oestradiol was identified. In the second state atretic follicles, showing hyperplasia and hypertrophy of thecal cells without granulosa cells, an increased incorporation into androgens was shown. Treatment with HCG induced similar but much pronounced changes in function and morphology. In the third stage atretic follicles, with subsiding thecal cells, a diminished incorporation into androstenedione was observed with 17-hydroxyprogesterone being the only other steroid formed in this stage. The observed qualitative and quantitative changes of steroidogenesis in vitro may be functional reflections of structural changes during the atretic process.

Acetates↗
PubMed1982

Influence of sulpiride-induced hyperprolactinemia on baboon menstrual cycles: a longitudinal study.

The influence of sulpiride-induced hyperprolactinemia on the hypothalamic-pituitary-ovarian function of the baboon (Papio cynocephalus) was investigated. Plasma levels of prolactin, LH, FSH, estrone, estradiol, 17-hydroxyprogesterone, progesterone and 20 alpha-dihydroprogesterone in control and consecutive treatment cycles (sulpiride i.m. injections 100 mg/day) were determined serially. The hormonal changes indicate that the ovary is the most sensitive site to the direct inhibitory action of sulpiride-induced hyperprolactinemia.

Animals↗
PubMed1982

Effect of pilocarpine on behavior of mucus glycoproteins of canine tracheal secretory cells.

Behavior of mucus glycoproteins in tracheal secretory cells after treatment with pilocarpine was investigated histologically and histochemically using the isolated canine trachea. Following pilocarpine treatment, the number of total and neutral glycoprotein-containing goblet cells was reduced concentration-dependently. The number of acid glycoprotein (AGP)-containing goblet cells was not altered with 10(-7) and 10(-6) M pilocarpine, but significantly decreased with 10(-5) and 10(-4) M pilocarpine. The thickness of the acini of submucosal glands significantly decreased, and the ratio of acinar inner diameter to tracheal wall thickness increased in 10(-5) and 10(-4) M pilocarpine. AGP content in glandular cells increased in 10(-7) and 10(-6) M pilocarpine, but markedly decreased at concentrations of 10(-5) and 10(-4) M. Pilocarpine treatment caused an increase in N-acetylhexosamine concentration in the incubation fluid. Total saccharide concentration in the incubation fluid decreased in 10(-7) and 10(-6) M pilocarpine, but was not apparently altered at concentrations of 10(-5) and 10(-4) M. These findings suggest that lower concentrations of pilocarpine stimulate synthesis of AGP in goblet and glandular cells much more preferentially than it stimulates discharge of AGP from the cells. While at higher concentrations, the AGP-discharge effect overcomes the stimulation in synthesis.

Animals↗
PubMed1982

Sperm penetration in vitro of human oocytes matured in a chemically defined medium.

Human oocytes were obtained randomly from the ovaries excised from 28 patients at different stages of the menstrual cycle. When 114 oocytes were cultured for 40-40.5 h in a chemically defined medium 80 showed degeneration. When 16 of the remaining 64 oocytes were examined for their maturation, germinal vesicle breakdown (GVBD) had occurred in 11 oocytes. Another 48 oocytes were inseminated by ejaculated spermatozoa which were washed twice and preincubated for 3 h. When examined 10 h later, 19 (39.6%) were penetrated with an enlarged sperm head or male pronucleus(ei) and its corresponding sperm tail(s).

Adult↗
PubMed1982

Diagnosis of submucosal tumors by injecting a water soluble contrast medium: basic research and imaging of tumors.

With the aim of adequately distinguishing gastric submucosal tumors from other lesions such as gastric polyps, gastritis, and protuberances due to extragastric pressure, a new method was developed. A water soluble contrast medium is endoscopically injected into a submucosal lesion followed immediately by the application of roentgenography, thereby obtaining X-ray pictures of the lesion through frontal and lateral projections. Since the contrast substance is water soluble, the method can visualize submucosal microchanges. Highly diffusible, the substance usually has a fading time of about 40 min, the present method is convincingly free of danger. This paper provides the results of basic research performed using adult mongrel dogs together with some comments on the applicability of the method in clinical use.

Adult↗
PubMed1982

Diagnosis of submucosal tumors by injecting a water soluble contrast medium: diagnosis of tumors and clinical presumption of their development patterns.

So far there have been no clinical methods claiming reasonable estimation of the patterns of submucosal tumors. In an attempt to shed some light on this difficult task, we have elaborated an endoscopical procedure; injecting a water soluble contrast medium into the submucosa and immediately applying roentgenography, we have obtained an X-ray image of the object lesion, visualizing its frontal and lateral aspects, which could help us outline the intramural characteristic of the tumor, informing us of its development mode. The device suggests its far-reaching contributions to the possible diagnosis of submucosal tumors prior to treatment and confirmation of their indications adequate for endoscopical treatment. Our method may potentially represent an ideal step to the consummation of endoscopic treatment of tumors, the success of which is dependent on the prevention of major bleeding and perforation.

Adolescent↗
PubMed1982

Mechanism of action of 2-crotonyloxymethyl-4,5,6-trihydroxycyclohex-2-enone, a SH inhibitory antitumor antibiotic, and its effect on drug-resistant neoplastic cells.

An inhibitor of alkaline phosphodiesterase was isolated from a soil Streptomyces. The agent was identified with 2-crotonyloxymethyl-4,5,6-trihydroxycylohex-2-enone (COTC) by UV, IR, 1H HMR and 13C NMR spectrometry. The mechanism of tumor-inhibitory action of COTC was studied with murine lymphoblastma L5178Y cells. COTC blocked alkaline phosphodiesterase; IC 50 was 60 micrograms/ml by the method employed. The growth of L5178Y cells was inhibited by COTC; IC50 was 4.4 micrograms/ml. DNA biosynthesis was preferentially prevented by COTC over RNA and protein syntheses; IC50 of DNA synthesis was 7 or approximately 25 micrograms/ml. COTC significantly inhibited DNA polymerase alpha even in the presence of dithiothreitol. The mitosis was markedly blocked by COTC; complete inhibition was observed at a drug concentration of 20 microgram/ml. Adriamycin-, aclarubicin- and bleomycin-resisant cell subline showed collateral sensitivity to COTC. COTC and aclarubicin exhibited synergistic activity on aclarubicin-resistant cells, but not on the parental cells. COTC increased uptake of [3H]adriamycin or blocked the drug efflux in the resistance cells, but not in the parental cells. The effects of COTC on macromolecular syntheses, mitosis and membrane functions may be attributed to the interaction with the sulfhydryl group of various enzymes. Although COTC is multifunctional drug, the inhibition of DNA polymerase alpha and a certain mitotic process seems to be related to the lethal action.

Animals↗
PubMed1982

Cadeguomycin, a noval nucleoside analog antibiotic. I. The producing organism, production and isolation of cadeguomycin.

An actinomycete strain IM7912T was found to produce cadeguomycin, a new nucleoside analog antibiotic, together with tubercidin. Morphological, cultural and physiological studies showed that the organism belongs to the species Streptomyces hygroscopicus. Comparisons with S. hygroscopicus ISP 5578 revealed that both strains possess similar characteristics except for production of yellow or brownish yellow soluble pigment in some media. Cadeguomycin was isolated from the culture filtrate, separated from tubercidin, and purified.

Anti-Bacterial Agents↗
PubMed1982

Cadeguomycin, a novel nucleoside analog antibiotic. II. Improved purification, physicochemical properties and structure assessment.

Cadeguomycin, a new nucleoside analog antibiotic, has been purified as colorless needle crystals by recycling preparative HPLC. The antibiotic, C12H14O7N4, mp 231 approximately 239 degrees C (dec.), FD-MS: m/z 326 (M+); is a weakly acidic substance, showing UV gamma H2Omax (epsilon) 232 (19677), 272 (6881) and 298 nm (7607), and IR nu KBrmax 1650 (C = O) and 3420 (NH or OH) cm-1. The UV spectrum is similar to other pyrrolo[2,3-d]pyrimidines. The structure of cadeguomycin, 2-amino-3,4-dihydro-4-oxo-7-beta-D-ribofuranosyl-7H-pyrrolo[2,3-d]pyrimidine-5- carboxylic acid, has been elucidated by 1H NMR and 13C NMR in comparison with other pyrrolo[2,3-d]pyrimidines and their nucleosides.

Anti-Bacterial Agents↗