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Biomedical subjects

T Higashi

Publications and source records attributed to T Higashi.

At least 415 records · Page 23Linked to original sources
PubMed1982

The L-methionine-sparing effect of dietary glutathione in rats.

The availability of cysteine moiety released from dietary glutathione (GSH) for protein synthesis in rats was studied to determine the L-methionine-sparing effect of this peptide. Animals were fed diets containing 18% of an amino acid mixture having a composition similar to that of whole egg, with or without GSH. The proportions of L-methionine, L-cysteine and GSH in the diet were varied, and one of these components was labeled with 35S. The incorporation of label into proteins and GSH in the liver and into proteins in the plasma was determined to assess the utilization of the sulfur atoms in these sulfur-containing substances. Dietary [35S]GSH was found to be incorporated efficiently into proteins and GSH in the liver and into plasma proteins. The results demonstrate the L-methionine-sparing effect of dietary GSH, in terms of incorporation Of its 35S into proteins and GSH. GSH spared L-methionine almost as efficiently as L-cysteine in plasma protein synthesis, though slightly less in liver protein synthesis. The effect of GSH increased with increase in its concentration in the diet.

Animals↗
PubMed1982

Immature precursor catalase in subcellular fractions of rat liver.

Dialysis of the peroxisomal extract, microsomal extract and cytosol fraction of rat liver against a solution containing 44 mM acetate buffer, pH 4.1, and 22% ethanol resulted in elimination of immature and enzymatically inactive catalase as insoluble precipitates, leaving mature and active catalase in solution. These catalase molecules in the three different subcellular compartments were doubly labeled with injected radioactive amino acids, for 30 min with [3H]leucine and for 90 min with [14C]leucine. The specific radioactivities of peroxisomal catalase remained unchanged upon the dialysis described above. This was also the case with microsomal catalase, however, the values were much higher than those of peroxisomal catalase. On the other hand, cytosol catalase showed remarkably decreased radioactivities after the dialysis, which were comparable to those of peroxisomal catalase, and the immature and inactive catalase which had been removed by this treatment was estimated to be as highly radioactive as the microsomal catalase. By affinity chromatography using anticatalase antibody both the microsomal extract and cytosol fraction were found to contain enzymatically inactive and probably immature catalase, which did not occur in peroxisomal extracts. However, when examined by SDS-polyacrylamide gel electrophoresis, the catalases in the three different subcellular fractions gave identical single bands corresponding to the monomer subunit of this enzyme protein, and no other larger molecule was detected. It was also found that the peroxisomal mature catalase did not migrate in polyacrylamide gel electrophoresis the same as that in microsomes and in cytosol, the latter two exhibiting the same mobility. Based on these results and others previously obtained, intracellular events in the maturation and transfer of newly synthesized catalase are discussed.

Animals↗
PubMed1982

Ga-67 scan as a prognostic indicator in primary lung carcinoma.

GA-67 scintigraphy was performed on 74 patients with a variety of histologic types of untreated primary lung carcinoma. Ga-67 uptake was determined, allowing for differences in tumor size. Ga-67 uptake was compared with the response to the incidence of metastases, and to host survival in the 74 patients. From these results, it is suggested that the greater the Ga-67 accumulation in the tumor, the higher the incidence of metastases and the shorter the host survival. Ga-67 scintigraphy appears to be a valuable tool in indicating the prognosis following radiation therapy in patients with primary lung carcinoma.

Adenocarcinoma↗
PubMed1982

Effects of insulin and glucagon on serum amino acid concentrations in liver disease.

The effects of insulin and glucagon administration on serum amino acid levels were investigated in patients with severe liver disease, since simultaneous injection of pancreatic hormones has been recently introduced as a therapeutic approach. The changes in serum amino acid concentrations, as observed 3 h after ceasing a 3 h infusion of insulin and glucagon in 500 ml glucose solution, were an elevation of serum branched chain amino acid (BACA) levels and of the molar ratio of BCAA/aromatic amino acid (AAA) levels in patients with liver cirrhosis. Similar increases of serum BCAA levels during the infusion were also observed in patients with fulminant hepatitis. The results suggest that insulin-glucagon therapy for severe liver disease has no harmful side effects at least with respect to alterations in the serum aminogram.

Amino Acids↗
PubMed1982

Cross-sectional study of pulmonary function in cadmium alloy workers.

Two groups of cadmium workers (7 and 9 men) and a group of reference workers (122 men) were studied for the purpose of determining the pulmonary effects of cadmium. Indices of pulmonary function, based on the forced expiratory flow volume curve and respiratory impedance, were measured for all the groups, and indicators of cadmium exposure and effects on renal tubular reabsorption functions were also measured in the two groups of cadmium workers. The mean blood and urinary levels of cadmium were 2.08 microgram/100 ml (185.06 nmol/l) and 32.6 microgram/l (290.04 nmol/l), respectively, and the level of inhalation exposure was estimated at about 1 mg/m3 as the 8-h average concentration for about 5 a in the high exposure group. The percentage of the predicted function values of the highly exposed workers was significantly deteriorated for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), peak expiratory flow, maximum expiratory flow at 75, 50, and 25% of the FVC, percentage of FEV1.0 to FVC, and respiratory impedance, whereas those of the slightly exposed workers were reduced only for FVC and FEV1.0. A paired comparison between the highly exposed workers and matched referents disclosed the same results. It was concluded that chronic obstructive pulmonary changes had been induced by cadmium in Japanese workers without a history of acute or subacute cadmium pneumonitis.

Adult↗
PubMed1982

The relationships between the Ga-67 uptake and nuclear DNA Feulgen content in thyroid tumors: concise communication.

It has been reported that Ga-67 uptake by malignant tumors differs somewhat according to the histologic type. Previously, we reported that uptake of Ga-67 is predictably low in well-differentiated adenocarcinoma of the thyroid gland but high in anaplastic carcinoma and malignant lymphoma. We studied the relationship between Ga-67 uptake and nuclear DNA content in four papillary adenocarcinomas, three follicular adenocarcinomas, three anaplastic carcinomas, and five malignant lymphomas of the thyroid gland. In anaplastic carcinoma and malignant lymphoma, the nuclear DNA content and proliferative index were significantly higher than in well-differentiated adenocarcinoma. These results suggest that there is close correlation between Ga-67 uptake and degree of malignancy of thyroid tumor cells.

Adenocarcinoma↗
PubMed1981

Relative contributions of sulfur atoms of dietary cysteine and methionine to rat liver glutathione and proteins.

The relative contributions of sulfur atoms of dietary L-Cys and L-Met to the syntheses of proteins and GSH in rat liver were examined. 1) When the amount of sulfur-containing amino acids in L-Trp-deficient diets was fixed at 0.36%, incorporation of L-[35S]Cys into GSH was proportional to the amount of L-Cys administered, in the presence of L-Met in the diet. Incorporation of 35S from L-Met into GSH was lower than that from the same amount of L-Cys and became negligible in the presence of a large amount of L-Cys. 2) When rats were given L-Trp-deficient diet, more L-Cys was always incorporated into liver GSH than into proteins. But, when rats were given L-Trp-fortified diet containing more L-Met than L-Cys, more L-Cys was incorporated into liver proteins than into GSH. 3) Met-sulfur was preferentially incorporated into liver proteins with or without L-Trp. Its absolute incorporation into proteins was significantly greater in the presence of L-Trp than in its absence. 4) When the amount of L-Met in the diet was increased from 0.18 to 0.36 or 0.54%, incorporation of Met-sulfur into proteins increased proportionally, in the presence of 0.18% L-Cys. Unexpectedly, incorporation of L-Cys formed from L-Met into liver proteins was larger than that from L-[3H]Met itself. L-Cys formed from L-Met was incorporated into proteins more readily than L-Cys given as such. 5) When the amount of L-Met in the diet was increased from 0.18 to 0.54%, incorporation of Met-35S into GSH increased 8-fold. Even with a large excess of L-Met, L-Cys was invariably incorporated into GSH. 6) These results are consistent with the role of liver GSH as a reservoir of cysteine, as proposed by us.

Animals↗
PubMed1981

Sodium dodecyl sulfate-sensitive septation in a mitomycin C-sensitive, mtc, mutant of Escherichia coli.

A mitomycin C-sensitive, mtc, mutant of Escherichia coli has an altered cell surface and is sensitive to sodium dodecyl sulfate (SDS). The mutant, M27, formed multinucleate nonseptated filaments in the presence of a low concentration of SDS (50 microgram/ml). When the culture grown at that concentration of SDS was diluted with an SDS-free medium, the filaments began to divide at a very rapid rate after a lag of about 20 min. Chloramphenicol inhibited this recovery division when added within 10 min after SDS dilution but did not inhibit the division when added 20 min after dilution. Penicillin G at a low concentration, which is enough to cause filamentation, had virtually no effect on the recovery division of SDS-induced filaments. The division of penicillin G-induced filaments was inhibited by SDS.

Chloramphenicol↗
PubMed1981

[Airway response to short-term inhalation of NO2, O3 and their mixture in healthy men (author's transl)].

One hour inhalation of 0.7 ppm (1.32 mg/m3) of nitrogen dioxide (NO2), 0.7 ppm (1.4 mg/m3) of ozone (O3), and their mixture, 0.5 ppm (0.9 mg/m3) of NO2 and 0.5 ppm (1.0 mg/m3) of O3, and sham inhalation were conducted in five healthy male volunteers through mouth breathing using a multipurpose inhalation apparatus. Airway response was measured by specific airway conductance (Gaw/Vtg) and maximum expiratory flow rate at 50 and 25 percent forced vital capacity (Vmax50, Vmax25). Evaluations by analysis of variance revealed: no significant effect of inhalation of NO2 alone, slight significant transient decrease of Vmax50 in inhalation of O3 along (0.1 greater than p greater than 0.05), and slight reversible decrease of Gaw/Vtg and Vmax50 in inhalation of NO2 and O3 in combination (0.1 greater than p greater than 0.05). As their variations were within the range of normal diurnal change, these results were considered to be non-adverse effects.

Adult↗