Search PubMed⌕ Search

Biomedical subjects

T Nishimura

Publications and source records attributed to T Nishimura.

At least 1,513 records · Page 84Linked to original sources
PubMed1981

Alteration of membrane-associated enzymes in drug-resistant sublines of mouse lymphoblastoma L5178Y cells.

Activities of marker enzymes for various cell components were studied with extracts of adriamycin-, aclacinomycin A- and bleomycin-resistant cells and with partially purified plasma membrane fraction of aclacinomycin A-resistant cells, in comparison with those of the parental cells. Alkaline phosphodiesterase and Na+-K+-ATPase activities were observed to alter in the drug-resistant sublines, but other enzymes showed similar activities in the resistant cells to those in the parental cells. Alkaline phosphodiesterase activities in all the resistant sublines were higher than that in the parental cells. Na+K+-ATPase activities of anthracycline-resistant sublines were lower and that in bleomycin-resistant cell line was higher than that of the parental cells. The adriamycin-resistant cells exhibited the same level of alkaline phosphodiesterase activity with the aclacinomycin A-resistant cells: Vmax was the same with, and the affinity was twice stronger than the parental cells. The bleomycin-resistant cells showed ca. 30% Vmax in comparison with the sensitive cells, and 17 fold higher affinity than the parental cells. The current results, concerning changes of membrane-associated enzymes in drug-resistant sublines of L5178Y cells, support the assumption that the resistance is due to alteration of plasma membrane transport systems.

Aclarubicin↗
PubMed1981

Antitumor activity of an antibiotic identical with or closely related to xanthomycin A.

An antibiotic, identical with or closely related to xanthomycin A, was isolated from a soil Streptomyces. The antibiotic displayed significant therapeutic activity by i.p. administration against i.p.-implanted mouse tumors: Ehrlich carcinoma, sarcoma 180 and P388 leukemia. Less therapeutic activity was observed by i.p. injection in mice bearing s.c. solid tumors of Ehrlich carcinoma and sarcoma 180. No significant activity was found against L1210 leukemia, B16 melanoma and Lewis lung carcinoma. In vitro the antibiotic exhibited a potent cytotoxicity to human leukemia K562 and mouse lymphoblastoma L5178Y cells. DNA strand scission of PM2 phage was caused by the antibiotic in the presence of dithiothreitol.

Animals↗
PubMed1981

The adrenergic nerve supply to bovine ovarian follicles.

To obtain more exact knowledge of the adrenergic innervation around ovarian follicles at various stages, a combination of fluorescence and light microscopic observations of the same specimen was applied to the bovine ovary in the breeding season. We found no fluorescent nerve fibers in the membrana granulosa at any stages of follicular development. The sparse nerve fibers found in the theca interna of Graafian follicles were apparently those accompanying blood vessels, and such were considered not to play a significant role in the vasomotor control of follicular blood flow. The fluorescent fibers in the theca externa increased in density and intensity in the course of follicular development. This increase appears to coincide with the increasing contractility of the follicular wall around the time of ovulation.

Animals↗
PubMed1981

[Basic and clinical studies of cefotiam in pediatric field (author's transl)].

The basic and clinical studies of cefotiam (CTM) in pediatric infections were carried out, and the following results were obtained: 1. The antibacterial activity of CTM against S. aureus was equal or slightly less than that of cefazolin (CEZ). Those of CTM against E. coli and K. pneumoniae were eight times more active than those of CEZ. 2. CTM 20 mg/kg was administered wither by 30 minutes or 1 hour intravenous drip infusion. The peak serum levels were obtained at the end of each drip infusion, with the mean peak levels being 44.8 and 41.4 mcg/ml respectively. The serum levels at 1.5 and 2 hours after drip infusion were 2.8 and 2.2 mcg/ml respectively, and at 3.5 and 4 hours after drip and 4 hours after drip infusion were 0.3 and 0.7 mcg/ml respectively. The half lives were 0.62 and 1.15 hours, respectively. The mean urinary excretion over 6 hours were 52.8% in ;the 30 minutes drip infusion group and 42.6% in the 1 hour drip infusion group. 3. Clinical efficacy was evaluated in sixteen cases suffering from tonsillitis (4 cases), pneumonia (4), bronchitis (2), cervical lymphadenitis (2), purulent meningitis (2), suppurative arthritis (1) and suspected sepsis (1). Good and excellent responses were obtained in 15 of 16 cases (93.8%). Bacteriological response in the form of eradication was noted in 4 of 6 cases. Side effect observed was rash in 1 case, and laboratory abnormalities were elevation of BUN in 1 case and elevation of GPT in 2 cases.

Adolescent↗
PubMed1981

[Morphological and endocrinological study of ovarian arrhenoblastoma (author's transl)].

Morphological and endocrinological studies were performed on a 19-year-old case of an arrhenoblastoma with marked virilization. The tumor was an intermediate type of Meyer's classification. Histochemically, 3 beta-HSD and G-6-PDH activities were demonstrated in Leydig cells. These cells also had ultrastructures typical of steroid-producing cells. Basal blood cells of pregnenolone, dehydroepiandrosterone, testosterone (T), androstenedione (A), progesterone, estradiol, estrone, LH, and FSH were determined pre- and postoperatively. T and A showed a very high level preoperatively, and were markedly decreased immediately after removal of the tumor. Stimulation of tumor cells by HMG-HCG did not show any significant changes in their main products of T and A. These findings suggest that Leydig cells of the present tumor produced mainly A and T independently on gonadotropins, and these hormones had virilized the patient.

Adult↗
PubMed1981

[DNP-peptidase activity in the rabbit ovary (author's transl)].

To examine the possible roles of collagenolytic enzymes in the follicular wall at ovulation, we measured in rabbit ovaries collagenolytic enzymes by using synthetic substrates, DNP-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg OH supposed to be specific for vertebrate collagenase. Our results clearly demonstrated that DNP-peptidase activity existed, with its optimal pH7.6-pH7.8 in rabbit ovarian follicles. DNP-peptidase activity steadily increased for nine hours following the hCG injection. After nine hours of enzyme activity decreased sharply until about the tenth hour, at which time ovulation had occurred. This pattern of enzyme activities indicates that the DNP-peptidase was consumed for degradation of collagen fibers. After collagen fibers have been completely degraded, this enzyme was increased again. These changes of DNP-peptidase activities at ovulation were similar to cathepsin B1 activities with its optimal pH6.0. It is concluded that DNP-peptidase could be one of ovulatory enzymes in the rabbit.

Animals↗
PubMed1981

[Laboratory and clinical studies of 6059-S in pediatric field (author's transl)].

The authors have carried out the laboratory and clinical studies of 6059-S. The results were as follows: The sensitivity was estimated by the plate dilution method on 27 strains of S. aureus, 26 strains of E. coli, K. pneumoniae and P. aeruginosa, 21 strains of Salmonella sp. and 9 strains of GM resistant P. aeruginosa isolated from patients. The distribution of sensitivity of S. aureus was 6.25-12.5 micrograms/ml and the peak of distribution was 6.25 micrograms/ml. The growth of 80.8% of E. coli was inhibited at concentration of less than 0.1 microgram/ml. The growth of 88.5% of K. pneumoniae was inhibited at concentration of less than 0.2 microgram/ml. The growth of 81.0% of Salmonella sp. was inhibited at concentration of less than 1.56 microgram/ml. The distribution of sensitivity of P. aeruginosa was 12.5- greater than 100 micrograms/ml and the peak of distribution was 25.0 micrograms/ml. The distribution of sensitivity of GM-resistance P. aeruginosa (greater than or equal to 25 micrograms/ml) was 12.5-50 microgram/ml and 5 of 8 strains were inhibited at concentration of less than 25 micrograms/ml. Phagocytosis was determined by Quie's method. Phagocytosis of E. coli, K. pneumoniae, Proteus vulgaris and Enterobacter cloacae by human polymorphonuclear neutrophil was more enhanced in the presence of 1 MIC and 1/2 MIC for 6059-S than for cefazolin at 4 and 6 hours after incubation. But phagocytosis of S. aureus did not enhanced in the presence of 6059-S. 6059-S was given by intravenous administration for 5 minutes and drip infusion for one hour at a single dose of 10 mg/kg of 6059-S to 3 and 4 children respectively. After intravenous administration of 6059-S, the mean peak serum level was 76.0 +/- 2.0 micrograms/ml at 15 minutes, 36.0 +/- 2.8 micrograms/ml at one hour, 1.5 +/- 0.4 micrograms/ml at 6 hours respectively. Half-life time was 1.3 hours. And after drip infusion of 6059-S was 39.9 +/- 9.7 micrograms/ml at one hour, 11.7 +/- 4.8 micrograms/ml at 3 hours and 1.8 +/- 1.4 micrograms/ml at 7 hours respectively. Half-life time was 1.4 hours. The mean urinary excretion rate was 90.4 +/- 6.1%, 76.5 +/- 16.0% up to 6 hours after intravenous administration and drip infusion respectively. 6059-S was effective in 17 cases out of 18 cases with bacterial infections. No side effects were observed except for 4 cases with elevation of serum transaminase, each on case of eosinophilia and of anemia.

Adolescent↗
PubMed1981

[Tensile deformation behaviour and mechanical properties in dental Ni-base casting alloys (author's transl)].

Tensile deformation behaviour and mechanical properties were studied in dental Ni-base casting alloys as 32 Ni-23 Cu-25 Mn(alloy 1) and 84 Ni-9 Cr systems (alloy 2). 1) Stress-strain curves of alloys 1 and 2 showed, respectively, a liner hardening-type and a type of a gradual increase in stress with tensile strain. 2) Specific deformation behaviours of alloys 1 and 2 with tensile strain, respectively, offered different values in mechanical properties; alloy 2 that showed larger elongation and strength than brittle alloy 1 indicated ductile characteristics of good elasticity and elastic regilience. 3) Fracture mechanism in alloys 1 and 2 was corresponding to intercrystalline crack i. e. brittle fracture and transgranular crack within cell structure i. e. ductile fracture, respectively.

Dental Alloys↗