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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,603 records · Page 89Linked to original sources
PubMed1979

Mutagenicity of metabolites of carcinogenic aminoazo dyes.

The mutagenicity of 8 azo dyes and 6 p-phenylenediamine derivatives, which comprised the metabolites of carcinogenic 4-aminoazobenzene derivatives, was studied on Salmonella typhimurium TA98 and TA100. 4'-Hydroxy-N-methyl-4-aminoazobenzene and its O-sulfate and O-glucuronide, and 3-hydroxy-4-aminoazobenzene were mutagenic on TA98 in the presence of S-9 mix. p-Phenylenediamine and its o-methoxyl derivative were definitely mutagenic on TA98 with the addition of S-9 mix. All metabolites tested were non-mutagenic on TA100, although the mother azo dyes were mutagenic both on TA98 and TA100 in the presence of S-9 mix. These results rule out a possibility that the mutagenicity, at least on TA100 microbes, of carcinogenic 4-aminoazobenzene derivatives may be mediated by any of the ring-hydroxyl or azo reduction metabolites and their conjugates produced from the azo dyes by incubation with S-9 mix.

Azo Compounds↗
PubMed1979

Neuromuscular blocking potency of fazadinium in man.

The study was designed to compare the recovery rates of fazadinium and four other commonly used competitive muscle relaxants in forty patients and eight volunteers. One-fifth to 1/10 of the clinical doses of the muscle relaxants were diluted in 20 ml of saline and injected intravenously at the wrist after inflation of a pneumatic tourniquet on the upper arm. After 3 min the tourniquet was released and the recovery time of twitch tension from 25 to 75% of the control determined. Evoked force of middle finger adduction was measured at a frequency of 0.2 Hz. The mean 25-75% recovery times of twitch tension for tubocurarine, pancuronium, alcuronium, gallamine and fazadinium were 14.20 +/- 1.42, 12.30 +/- 1.02, 10.12 +/- 0.77, 10.07 +/- 1.12 and 9.90 +/- 0.87 min, respectively. The authors conclude that the dissociation rate of fazadinum from the receptor of the motor endplate appears to be the fastest among the competitive muscle relaxants studied in man.

Adolescent↗
PubMed1979

Light- and electron-microscopic studies on the gastric parietal cells in perinatal rats. Effects of fetal and neonatal oral administration of milk.

Perinatal changes of the gastric parietal cells were studied under normal and various experimental conditions. Histologic examination revealed that the parietal cells appeared markedly increased in number from late fetal to early neonatal days. When premature newborn rats were delivered by cesarean section and were nursed by foster mothers for 1 or 2 days, the degree of increase of these cells reached nearly that in the normal neonates. On the other hand, in fetuses retained in utero 1 day beyond the normal gestation, these cells appeared not increased in number. When these postmature fetuses were delivered, the parietal cells turned to increase in number in a degree similar to that in the normal neonates. Milk given to the premature newborn rats caused 6 h later a marked increase in the number of the parietal cells. Milk given to fetuses in utero also caused an increase of these cells. The results suggest that the development of the parietal cells in perinatal rats is accelerated by the intake of milk and that the fetal parietal cells are ready to respond to milk given at least 1 day before birth.

Age Factors↗
PubMed1979

Effect of 1 alpha-hydroxyvitamin D3 in rats with experimental renal osteodystrophy.

A model of experimental renal osteodystrophy was established in the rats with chronic renal failure induced by partial nephrectomy and therapeutic effects of 1 alpha-hydroxyvitamin D3 (1 alpha-OH-D3) were studied. Male Wistar rats weighing 180 g were 5/6 nephrectomized and fed a normal diet (Ca and P : 1%) for 6 months. After the surgery, serum creatinine levels increased 60% and thereafter continued to rise gradually with their growth for 4 to 5 months, followed by rapid increase. The serum phosphorus levels were also elevated concomitantly and the serum calcium concentrations were normal. Marked bone resorption accompanied with hypertrophy of parathyroid glands was observed by histological examinations (Tetrachrome-Fuchsin stain, contact microradiography and H-E stain). The bone resorption seemed to be due to secondary hyperparathyroidism. Treatment with 0.25 micrograms/kg/day p.o. of 1 alpha-OH-D3 for 10 days in the uremic state resulted in remarkable new bone formation which was confirmed by histological examinations. These results clearly demonstrated that the reduction of nephron mass play a critical clue of renal osteodystrophy and 1 alpha-OH-D3 appears to have a good potential for clinical use in patients with renal failure and metabolic bone diseases.

Animals↗
PubMed1979

Neuromuscular blocking property of minocycline in the rabbit.

The neuromuscular blocking property of minocycline hydrochloride (MNC) was studied in 12 rabbits. In 2 of 6 animals, MNC, 60-160 mg/kg, alone caused a decrease in twitch tension. During partial neuromuscular blockade produced by a continuous infusion of pancuronium, the intravenous administration of MNC, 20--60 mg/kg, resulted in a dose-dependent decrease in twitch tension in 6 animals. MNC-induced or combined MNC-pancuronium-induced neuromuscular blockade was antagonized by calcium or by neostigmine.

Animals↗
PubMed1979

In vitro microbiological evaluation of TEI-1194 and TEI-2012, novel antipseudomonal semisynthetic penicillins.

TEI-1194, sodium 6-[D-(-)-alpha-(coumarin-3-carboxamide)-phenylacetamide] penicillanate and TEI-2012, sodium 6[D-(-)alpha-(8-hydroxy-coumarin-3-carboxamide)-phenylacetamide] penicillanate are new semisynthetic penicillin derivatives both possessing a broad spectrum of in vitro antibacterial activities. Minimal inhibitory concentrations of both agents were compared with carbenicillin. TEI-1194 and TEI-2012 were clearly found to have more potent activities especially against Pseudomonas aeruginosa than carbenicillin. At a concentration at 6.25 micrograms/ml, 85 approximately 90% of a total of 50 strains of clinically isolated P. aeruginosa were inhibited by TEI-1194 and TEI-2012, whereas carbenicillin had no effect. Evaluation of the antibacterial activity against a series of mutants producing different levels of beta-lactamases and test of the susceptibilities to some beta-lactamases demonstrated that TEI-1194 and TEI-2012 had low susceptibility to various cephalosporinases. However, both compounds were susceptible to penicillinase from Klebsiella pneumoniae H-2 at a rate of about 15% of penicillin-G taking its absolute rate as 100.

Bacteria↗
PubMed1979

Antigen characteristics of nitrosamine-induced urinary bladder cancer in rats.

Antigens expressed on urinary bladder cancer cells of transplantation and tissue culture lines, which originated in tumors induced by N-butyl-N-(4-hydroxybutyl)nitrosamine in individual ACI/N rats, were studied by several immunological methods. Tumor-specific transplantation antigen was determined by transplantability of cancer cells into syngeneic rats which had been immunized with the respective cancer cells by the ligation-and-release method. Two out of 6 bladder cancer lines showed high antigenicity but antigenicities of the other 4 lines were of low or undetectable level. Cross resistance was observed in the transplantation immunity among the 2 high antigenic lines but not in the other lines. Cell-mediated cytotoxicity was assayed by the microtestplate method. The lymphoid cells from ACI rats hyper-immunized with cancer cells of a high antigenic line showed a marked cytotoxicity against cancer cells of the immunizing line but not to cells of the other bladder cancer lines including another high antigenic line that induced a cross resistance in transplantation immunity. Tumor-associated cell-surface antigen was detected by membrane immunofluorescence test with serum which was raised in allogeneic Donryu rat by the high antigenic bladder cancer and absorbed with normal ACI rat tissues. The absorbed serum gave positive membrane fluorescence to cancer cells of the immunizing line and 2 other bladder cancer lines but not to cells of other 4 bladder lines and ACI tumors other than bladder cancer. The common antigen detected by the serological method was not reflected either in transplantation immunity or cell-mediated cytotoxicity of the immune lymphoid cells.

Animals↗