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Biomedical subjects

M Higuchi

Publications and source records attributed to M Higuchi.

At least 379 records · Page 21Linked to original sources
PubMed1984

Macrophage-activating factor for cytotoxicity produced by a human T-cell hybridoma.

Human MAF-C (macrophage-activation factor for cytotoxicity)-producing hybridoma H2-E3-5 was prepared by somatic cell fusion of PHA-activated peripheral blood lymphocytes with emetine/actinomycin D-treated cloned human acute lymphatic leukemia cells (CEM). The following activities were assayed: (1) macrophage-migration-inhibitory factor (MIF), (2) macrophage-activation factor for glucose consumption (MAF-G), (3) macrophage-activation factor for O2-formation (MAF-O), and (4) macrophage-activation factor for cytotoxicity (MAF-C). After anion-exchange chromatography, MAF-C activity could be distinguished from MIF and MAF-O activities. It is shown that MAF-C is not the same as MAF-G from the culture supernatants of CEM 11, a parent cell line of H2-E3-5. Furthermore, MAF-C from H2-E3-5 culture supernatants activated differentiated macrophages but not monocytes.

Antigens, Surface↗
PubMed1984

Biochemical characterization of arylsulfatases detected in granulomatous inflammation.

Arylsulfatases A and B were measured in the liver of mice infected with Schistosoma mansoni. The increase of total arylsulfatases paralleled enlargement of the granulomas. It began at 7 weeks after infection and reached a maximum at 10 to 14 weeks when the enzyme activity became about 2.5 times that of normal liver. The elevated enzyme activity was due to granulomatous tissue, because when granulomas were separated from hepatic cells, the former contained the increased activity but the latter did not. Arylsulfatase A, arylsulfatase B, and arylsulfatase Bv, in both normal liver and granulomas, were separated by anion-exchange column chromatography and differences in net charges of these enzymes were demonstrated by polyacrylamide gel electrophoresis. Biochemical properties were indistinguishable between arylsulfatase B and arylsulfatase Bv while they differed from arylsulfatase A. Granulomas at 8 weeks after infection showed 3.0-, 3.5-, and 5.0-fold increases in activity for arylsulfatase A, B, and Bv, respectively. As the granulomas enlarged, by 12 weeks, arylsulfatases B and Bv activities further increased but the arylsulfatase A value remained the same as that of 8 weeks. The finding suggests that arylsulfatases are involved in granuloma development and arylsulfatases B and Bv activities may reflect functions of macrophages and other cells including fibroblasts.

Animals↗
PubMed1984

The effect of oxygen on the growth and mannitol fermentation of Streptococcus mutants.

The effects of oxygen on growth and mannitol fermentation of eight strains of Streptococcus mutans were compared under aerobic and strictly anaerobic conditions. The growth of three strains was severely inhibited by oxygen, whereas the others were oxygen-tolerant. The growth of two of the oxygen-tolerant strains was significantly enhanced by oxygen. The activities of superoxide dismutase and NADH oxidase in extracts from aerobically grown bacteria showed a positive correlation with the growth rate under aerobic conditions. The activities of these enzymes in oxygen-sensitive strains grown aerobically were as small as those in anaerobically grown cultures. Moreover, the enzyme activities increased during aeration of anaerobically grown oxygen-tolerant strains, but not in oxygen-sensitive strains. In all strains, oxygen changed mannitol catabolism from heterolactic to homolactic fermentation. It was concluded that oxygen-tolerance of S. mutans is dependent on the ability of strains to induce NADH oxidase and superoxide dismutase.

Aerobiosis↗
PubMed1984

Effect of exercise training on plasma high-density lipoprotein cholesterol level at constant weight.

Previous investigations have demonstrated an increase of plasma high-density lipoprotein cholesterol (HDL-Chol) and a decrease in the ratio of low density lipoprotein (LDL)-Chol/HDL-Chol (Atherogenic Index; AI) as a result of exercise training. The question of whether elevation of HDL-Chol was a consequence of weight reduction or physical training itself was unsolved. The present study was designed to prevent the weight reduction that is associated with exercise training. Five healthy and mildly active male volunteers, aged 28-31 years, participated in a 4-week training programme. They ran on a treadmill at 140-160 m/min at 0% grade for 50 min, 5 times a week, equivalent to an energy expenditure of 9 kcal/kg body weight/day. Subjects maintained their body weights by increasing calorie intake to match increased energy expenditure. No changes were observed in mean body weight, skinfold thickness, basal metabolism, and maximal oxygen uptake after the training programme. The HDL-Chol level increased from 54 to 73 mg/dl (P less than 0.05), and the reduction of AI was 30.8% (P less than 0.05) in response to the exercise training. However, the exercise training did not induce changes in plasma total cholesterol and triglyceride (TG) levels. The results of this experiment suggested that moderate physical training itself can be a potent factor for the regulation of HDL-Chol level and improvement of the AI in the absence of alterations in body weight.

Adult↗
PubMed1984

Glycogen resynthesis in leg muscles of rats during exercise.

This study was undertaken to determine whether glycogen resynthesis can occur in glycogen-depleted muscles in response to glucose feeding during prolonged exercise. Rats were exercised for 40 min with a treadmill running program designed to deplete muscle glycogen. One group was studied immediately after the glycogen-depletion exercise. A second group was given 1 g glucose by stomach tube and exercised for an additional 90 min at a running speed of 22 m/min on a treadmill set at an 8 degree incline; they were given additional 1-g glucose feedings after 30 and 60 min of running. The initial 40-min run resulted in liver glycogen depletion, large decreases in plasma glucose and insulin concentrations, and a marked lowering of muscle glycogen. The glucose feedings resulted in greater than twofold increases in the concentrations of glucose and insulin in plasma, and of glycogen in leg muscles, during the 90 min of running. No repletion of liver glycogen occurred. These results provide evidence that glycogen resynthesis can occur in glycogen-depleted muscle despite continued moderate intensity exercise if sufficient glucose is made available.

Animals↗
PubMed1984

Posterolateral fusion with instrumentation in the symptomatic failed back patients.

Thirty-two symptomatic failed back patients after lumbar spine surgery performed for disc lesions underwent posterolateral fusion involving an adaptation of two distraction rod or combined distraction and compression rod instrumentation following decompression procedure when necessary. The main causative pathology of persistent pain was segmental instability with or without nerve root entrapment. The average follow-up period was 35 months. Twenty-eight patients responded that they were satisfied with the final operation. Fusion rate was 100% at the present study. The salvage instrumentation surgery to the failed back was thought to have brought about removal of instability, restoration of the disc height to some extent and decompression in some cases.

Adult↗
PubMed1983

Converting enzyme activity and essential hypertension.

Serum ACE-activity was studied in 27 young patients with uncomplicated essential hypertension. The possible importance of an increase in ACE for the pathogenesis of essential hypertension was evaluated by comparing the ACE levels to PRA, the plasma concentrations of angiotensin II and to the blood pressure lowering effect of captopril. Mean ACE-activity was slightly but significantly elevated in the hypertensive patients when compared to 28 normotensive control subjects. ACE-activity was not correlated to PRA, angiotensin II or the decrease in blood pressure following captopril. It is concluded that the increase in ACE-activity in essential hypertension is not of pathophysiological or clinical significance.

Administration, Oral↗
PubMed1983

Human T-cell hybridomas producing lymphokines. II. Enhancement of lymphotoxin secretion from human T-cell hybridomas by phorbol myristate acetate.

Human lymphotoxin (LT)-producing T-cell hybridomas were constructed by fusing concanavalin A-activated human peripheral blood lymphocytes with emetine-actinomycin D-pretreated human acute lymphatic leukemia cells. LT secretion from these hybridomas was considerably enhanced by stimulation with phorbol-12-myristate-13-acetate (PMA) and concanavalin A or PMA alone. A study using cloned hybrid lines revealed that PMA/Con A acted directly on the LT-producing clones. Furthermore, PMA/Con A stimulated A-B9-24, one of the cloned hybridomas, and secreted fourfold larger amounts of LT under serum-free conditions than under serum-containing conditions. However, MIF/MAF and LT-producing cloned hybrid line E10-20 secreted rather decreased amounts of MIF/MAF when stimulated with PMA, while the LT secretion from the same hybridoma was enhanced with PMA.

Clone Cells↗
PubMed1983

Human T-cell hybridomas producing migration inhibitory factor and macrophage activating factors.

Studies were carried out to determine the heterogeneity of factors that affect macrophage functions using human hybridomas constructed by fusing PHA-activated human peripheral blood lymphocytes with emetine-actinomycin D-pretreated cloned human acute lymphatic leukemia cells (CEM). Three assay systems were used to investigate the activity of the macrophage migration inhibitory factor and of the macrophage activation factors for glucose consumption (MAF-G) and for O2- formation. In the culture supernatant of hybridomas and other cells, various combinations of these activities were detected. The results indicate that at least three molecules are concerned in each of these activities.

Animals↗
PubMed1983

Effects of pentobarbital anesthesia on the plasma catecholamines and renin activity as reflected in the hemodynamic changes in dogs.

Correlation between hemodynamic changes and plasma catecholamines or renin activity were studied in dogs anesthetized with pentobarbital, 30 mg/kg, i.v. Pentobarbital increased heart rate in all cases regardless of changes in plasma catecholamines, and the increase was not depressed fully by propranolol. Blood pressure (BP) showed a transient decline just after pentobarbital injection and then elevated gradually to one of three levels 30-60 min after anesthesia. In low (62 +/- 4 mmHg, Mean +/- S.E.) and very high BP (169 +/- 7 mmHg), plasma norepinephrine (NE) showed low (305 +/- 55 leads to 89 +/- 22 pg/ml) and high levels (296 +/- 54 leads to 372 +/- 106 pg/ml), respectively, which probably reflect the neurosympathetic activities. In moderately high BP (112 +/- 4 mmHg), however, the hypertension did not necessarily reflect changes in plasma NE. When the level before anesthesia was 108-164 pg/ml, plasma NE increased, whereas it decreased when the level was 182-374 pg/ml. In either case, the level was fixed within 117-182 (154 +/- 6) pg/ml. Plasma renin activity increased after anesthesia and maintained for at least 2 hr. However, the increase were observed regardless of the BP level, and moderately high BP was not depressed by an angiotensin II antagonist. Participation of angiotensin in these sustained BP cases seems unlikely. Plasma epinephrine reflecting adrenal-medullary activity was decreased markedly in all cases, and the low level lasted for at least 2 hr. Changes in plasma dopamine are related to those in plasma NE, and the origin seems to be the same.

Anesthesia, General↗
PubMed1983

Effects of 2-nicotinamidoethyl nitrate (SG-75, nicorandil) on indomethacin-induced contractions of isolated dog coronary arteries.

Effects of 2-nicotinamidoethyl nitrate (SG-75) on contractile responses of dog coronary arteries to indomethacin were investigated in vitro. Indomethacin (3 X 10(-8) and 3 X 10(-7) Gm/ml) produced contractions of isolated coronary arterial strips, which were reproduced by successive administration of the drug. SG-75 (10(-5) Gm/ml) administered 5 min prior to indomethacin, significantly depressed indomethacin-induced contractions of the strips. In coronary arterial strips under potassium-contracture, SG-75 10(-8)-10(-4) Gm/ml) produced concentration-dependent relaxations, which were not affected by prior administration of indomethacin (3 X 10(-6) Gm/ml). Tranylcypromine (10(-4) Gm/ml) did not influence the relaxant responses of the strips to SG-75 (10(-8)-10(-5) Gm/ml) but significantly depressed them to SG-75 (10(-4) Gm/ml). Results indicate that large doses of SG-75 will induce a relaxant effect on isolated dog coronary arteries through activation of intravascular biosynthesis or release of prostacyclin from vascular tissues.

Animals↗