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Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 1,279 records · Page 71Linked to original sources
PubMed1985

Attenuation of aspirin analgesia by calcium loading in healthy subjects.

To clarify the mechanism of aspirin analgesia, the relationship among analgesic and hypocalcemic effects and pharmacokinetics of aspirin was investigated in 20 healthy subjects at 20-23 years old. Four experimental groups were made, that is, (1) aspirin 1.0 g, (2) aspirin 1.0 g + calcium gluconate 1.5 g X 2, (3) calcium gluconate 1.5 g X 2, (4) control (placebo). Calcium gluconate was administered orally twice, that is, 30 and 90 min after oral administration of aspirin. The experiments were carried out under a double blind method. As an analgesic test, the ultrasonic method was used. Aspirin (1.0 g) caused a significant analgesia, the effect reaching the maximum at 90 min and prolonging for about 3 h. Simultaneously, plasma calcium level significantly decreased and kept going down, at least, until 180 min after administration of aspirin. However, when calcium gluconate was loaded at 30 and 90 min after administration of aspirin, both the analgesic and hypocalcemic effects of aspirin were significantly inhibited. The plasma aspirin concentration reached a maximum 30-60 min after administration of aspirin in both groups: aspirin alone and aspirin with calcium gluconate. On the other hand, plasma salicylic acid concentration kept increasing up to 180 min after administration of aspirin in either group. The plasma aspirin and salicylic acid levels in both groups were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

The time interval effect on two consecutive LHRH-TRH tests on adult female baboons.

To Clarify the relationship between the time interval and pituitary Luteinizing hormone (LH), Follicular stimulation hormone (FSH) and prolactin (PRL) secretion function under LHRH-TRH stimulation, 4 mature female baboons were used. Two consecutive LHRH (100 micrograms)-TRH (250 micrograms) stimulations with a 60 min interval between them was carried out in the early follicular phase, late follicular phase and mid luteal phase in the same baboon in the first menstrual cycle, then carried out with a 120 min interval between tests in the third menstrual cycle. The LH, FSH and PRL were measured by specific radioimmunoassay. The PRL maximum response to the first bolus of TRH was higher than maximum response to the second bolus of TRH. The PRL maximum response to the second TRH at a 120 min interval was higher than the maximum response to the second TRH at a 60 min interval. It seems that the TRH had the dominant effect on PRL releasing but not on PRL Priming. The maximum LH response to the second bolus of LHRH was higher than the maximum response to the first bolus of LHRH. The LH maximum response to the second bolus of LHRH at a 60 min interval was greater than the maximum response at a 120 min interval in the follicular phase but it was the reverse in the luteal phase. The FSH response to the second LHRH was different from the LH response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Multiinstitutional evaluation of local injection of absolute ethanol as the new hemostatic method for upper G-I tract bleeding.

Local injection of absolute ethanol was proven effective for hemostasis of gastrointestinal bleeding in our fundamental (Asaki et al. 1983a) and clinical (Asaki et al. 1983b) studies. The purpose of the present paper is to report the results obtained in 258 hemorrhagic foci in 152 unselected cases treated with this method at 6 major hospitals in the Tohoku area in Japan. Sixty (39%) of these 152 cases had shock symptoms due to hemorrhage. Gastric and duodenal ulcers were responsible for the hemorrhage in about 90% of the cases in which our method was applied to hemostasis. Eighty-nine (59%) of the 152 cases had some form of complications such as malignant tumors or liver cirrhosis. Hemorrhage due to postoperative stress ulcer after major surgeries including renal implantation or laryngectomy for resection of cancer was seen in 20 cases (13%). The condition of hemorrhage immediately before the treatment with our technique was classified as spouting hemorrhage for 8 foci (3%), pulsating hemorrhage for 22 foci (9%), adhesion of clot for 179 foci (69%), and hemorrhage from veins and capillaries for 49 foci (19%). In all of these cases temporary hemostasis was obtained. Rebleeding occurred in 17 cases (7%) including 5 cases in which hemostasis was successfully obtained by the repeated use of our method. In 4 of the 17 cases, in which repeated endoscopy was infeasible, emergency surgery was performed. In the remaining 8 lesions in 8 cases, new bleeding or rebleeding occurred more than 1 week after the initial hemostasis had been obtained. Six of these 8 cases died from rebleeding due to DIC syndrome. With our method complete hemostasis was obtained in 144 of 152 cases (95%) including 11 cases (7%) which underwent elective surgical operation.

Adolescent↗
PubMed1985

New trial of endoscopic treatment for gastric submucosal tumors.

Recently conservative treatment of gastric submucosal tumors is increasing in spite of the absence of definite criteria for histological diagnosis. We have developed a new method of endoscopical treatment of gastric submucosal tumors that have submucosographically intraluminal Pattern I or II, or partly intramural Pattern III. For such tumors with a maximum diameter less than 5 cm, Ist step: partial resection is carried out with the use of high-frequency electric currents, IInd step: for the residual tumor tissue, in vivo tissue solidification is undertaken by local injection of absolute ethanol to induce necrotic exfoliation of the tumor tissue and to prevent of hemorrhage.

Adult↗
PubMed1985

Diagnosis of the depth of cancer invasion by submucosography.

A new method was developed to diagnose the depth of cancer invasion using submucosography combined with special charcoal suspension containing mitomycin C, and applied to 8 cases of gastric cancer. Correct diagnosis of the depth of the cancer invasion was obtained in 7 of the 8 cases. As some cases of early gastric cancer can be treated endoscopically, it is important to know the condition of the invasion before any treatment is performed.

Aged↗
PubMed1985

Mechanisms affecting peplomycin sensitivity of Chinese hamster cell lines.

Chinese hamster lung cell line V79 was ca. 13 times more resistant to peplomycin (PEP), and 6 times more resistant to bleomycin (BLM)-A2 than Chinese hamster ovary (CHO) cell line. The natural resistance of V79 cells to PEP or BLM was attributed to higher levels of BLM hydrolase activity and lower cellular uptake of the antibiotic. The sensitivity to PEP of a mutant clone CHO/O-2 T-1 was similar to that of CHO. A hybrid clone of CHO/O-2 T-1 X V79 showed an intermediate sensitivity to PEP between those of both parental cell lines, suggesting that the gene responsible for the natural resistance to PEP appears codominantly in the hybrid. The BLM hydrolase activity of the hybrid was also found intermediate between those of both parental cells. Mutant clones CHO/O-2 T-5 and CHO/O-2 T-6 were 8.3-9.0 times more sensitive to PEP than CHO cells. Hybrid clones CHO/O-2 T-5 X V79 and CHO/O-2 T-6 X V79 displayed PEP sensitivity similar to that of V79, suggesting that the gene responsible for the PEP supersensitivity (PEPss) behaves recessively in the hybrids. Both PEPss clones showed levels of BLM hydrolase and cellular uptake of [3H]PEP similar to the parental CHO cells, suggesting that the PEPss is due to neither BLM hydrolase nor cellular uptake of the antibiotic. Increased PEP-induced DNA cleavage and decreased DNA repair in the PEPss clones were demonstrated by alkaline sucrose density gradient sedimentation method. The results suggest that the PEPss of these mutant clones is attributed to decreased DNA-repairing activity and/or increased DNA-breaking activity.

Animals↗
PubMed1985

Lactoquinomycin, a novel anticancer antibiotic. I. Taxonomy, isolation and biological activity.

Lactoquinomycin, a novel basic antibiotic, was isolated from the culture broth of a soil streptomyces by repeated solvent extraction and adsorption column chromatography. Morphological, cultural and physiological studies revealed that the organism belongs to the species Streptomyces tanashiensis. The antibiotic was active against bacteria, particularly Gram-positive organisms, and neoplastic cells in vitro. Antibiotic-resistant cell sublines of L5178Y lymphoblastoma were more significantly inhibited by lactoquinomycin than the parental cell line. Lactoquinomycin was effective against Ehrlich carcinoma in mice.

Animals↗
PubMed1985

Studies on antineoplastic activity of naphthomycin, a naphthalenic ansamycin, and its mode of action.

An antibiotic, identical with naphthomycin, was isolated from a soil Streptomyces. The antibiotic displayed significant therapeutic activity by ip administration against murine tumors: Ehrlich carcinoma and IMC carcinoma implanted ip. The maximum increase of life-span was more than 169% in Ehrlich carcinoma, and 128% in IMC carcinoma. The antibiotic exhibited a potent cytotoxicity against murine leukemic cells: P388, L1210, and L5178Y. IC50 was 0.4-1.3 microgram/ml in culture. The activity of naphthomycin was reversed by SH compounds: 2-mercaptoethanol, dithiothreitol, and glutathione. DNA and RNA syntheses were more markedly inhibited by naphthomycin than protein synthesis in L5178Y cells. Approximately 50% inhibition of nucleic acid syntheses was observed at an antibiotic concentration of 2 micrograms/ml. Naphthomycin blocked alkaline phosphodiesterase obtained from L5178Y cells: IC50 was ca. 7.6 micrograms/ml. The antibiotic neither caused metaphase arrest nor prevented tubulin polymerization. The results suggest that the mechanism of cytotoxicity of naphthomycin is the inhibition of various SH enzymes, particularly those involved in nucleic acid biosynthesis. The mode of action is unique in the ansamycin group of antibiotics.

Animals↗
PubMed1985

Biological activity of cadeguomycin. Inhibition of tumor growth and metastasis, immunostimulation, and potentiation of 1-beta-D-arabinofuranosylcytosine.

Cadeguomycin retarded growth of sc solid IMC carcinoma in CDF1 mice, and pulmonary metastasis of Lewis lung carcinoma in C57BL/6 mice. The antibiotic enhanced phagocytic activity of murine peritoneal macrophages and IL-1 production by P388D1 cells. Delayed type hypersensitivity was stimulated and interferon was induced by the drug. The results suggest that cadeguomycin inhibits tumor growth and metastasis in association with modification of the immune system. The cytotoxicity of arabinosylcytosine to K562 and YAC-1 cells was markedly enhanced by cadeguomycin in culture. The combined administration of arabinosylcytosine and cadeguomycin displayed potentiation in the inhibition of growth of ip-implanted P388 leukemia and metastasis of sc-implanted P388 leukemia to the regional lymph nodes. Cadeguomycin showed low toxicity for mice.

Adjuvants, Immunologic↗
PubMed1985

Stimulated rat T cell-derived inhibitory factor for cellular DNA synthesis (STIF). II. Kinetics of the production and characterization of the producer.

Kinetics of the production of a stimulated T cell-derived inhibitory factor for cellular DNA synthesis (STIF) (1) from Con A-stimulated SD rat spleen cells, and the cells involved in the production of the factor, were examined comparatively with those of interleukin 2 (IL 2) and interferon (IFN). STIF activity in the culture supernatants reached a plateau 24 hr after the culture, and the plateau level was maintained during an additional culture for 72 hr. Characterization of the cells involved in STIF production by means of negative selection of unfractionated or nylon-fractionated spleen cells with anti-rat T cell serum or monoclonal antibodies plus complement revealed that the cells are nylon-nonadherent T cells bearing a suppressor T cell marker. The nylon-nonadherent T cell population did not require additional macrophages for STIF production. In vivo pretreatment of rats with cyclophosphamide (25 to 100 mg/kg) reduced or abolished the production of STIF from the Con A-stimulated spleen cells of the rats. The STIF production from Con A-stimulated spleen cells was inhibited by the addition of indomethacin at 10 ng/ml, indicating a regulatory role of prostaglandin(s) in STIF production. The above characteristics distinguish a T cell subset for STIF production from those for IL 2 and IFN production.

Animals↗
PubMed1985

Stimulated rat T cell-derived inhibitory factor for cellular DNA synthesis (STIF). III. Effect on cell proliferation and immune responses.

Stimulated T cell-derived inhibitory factor for cellular DNA synthesis (STIF), a lymphokine produced from concanavalin A (Con A)-stimulated rat suppressor T cells, was examined for its inhibitory effect on various cultured cells and on in vitro immune reactions. STIF could inhibit the DNA synthesis of a variety of normal and neoplastic cells from rats, mice, and humans in a dose-dependent fashion. Kinetics studies revealed that STIF selectively inhibited cellular DNA synthesis after incubation for 12 hr, but after 36 hr, it also inhibited RNA and protein syntheses. The inhibited cellular DNA synthesis by 12-hr incubation with STIF was recovered after culturing the cells in STIF-free medium. The inhibitory effect of STIF on the DNA synthesis was not blocked by addition of a sugar (alpha-methyl-D-mannoside, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, L-fucose, or L-rhamnose) in culture, as determined by using rat bone marrow cells. STIF inhibited proliferative responses of rat lymphocytes to T cell mitogens, Con A and phytohemagglutinin, and a B cell mitogen, lipopolysaccharide, as well as IL 2-dependent growth of cloned T572 cells. It could also inhibit both blastogenesis and cytotoxic T cell generation in allogeneic mixed lymphocyte reaction. The release of IL 2 from Con A-stimulated T cells was also inhibited by the added STIF in culture, as demonstrated from the finding that IL 2 activity was not detected in the supernatants even after an anion-exchange column chromatography. These results indicate that STIF could inhibit cellular DNA synthesis in a species-unrestricted manner and thus inhibits the proliferation of various normal and neoplastic cells, and that it could also inhibit lectin- or IL 2-dependent T cell proliferation as well as IL 2 production from T cells in in vitro immune reactions.

Animals↗