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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,441 records · Page 80Linked to original sources
PubMed1984

Genetic regulation of GM2 (NeuGc) expression in liver of mouse.

GM2 containing NeuGc was a major ganglioside in mouse liver of inbred strains such as DBA/2, BALB/c, C57BL/10 and C3H/He, which are commonly used for biochemical and immunological studies. On the other hand, the liver of WHT/Ht, an inbred strain, contained GM3 (NeuGc) as a major ganglioside and lacked GM2 (NeuGc). We report here that the GM2 (NeuGc) expression was analyzed in the liver of the progeny between WHT/Ht and DBA/2 and the positive expression of GM2 (NeuGc) was proved to be a dominant trait regulated by an autosomal single gene. Moreover, the N-acetylgalactosaminyltransferase activity to convert GM3 (NeuGc) to GM2 (NeuGc) was measured in the liver microsomal fraction of WHT/Ht, BALB/c and their F1. F1 expressed almost half of the activity in BALB/c and WHT/Ht did not express a detectable amount of activity. The backcross of F1 to WHT/Ht segregated into two groups. One expressed both GM2 (NeuGc) and the transferase activity and the other expressed neither of them. There was no exceptional individual which was not grouped into either of these two groups. These results indicate that GM2 (NeuGc) expression is directly regulated by the N -acetylgalactosaminyltregated into two groups. One expressed both GM2 (NeuGc) and the transferase activity and the other expressed neither of them. There was no exceptional individual which was not grouped into either of these two groups. These results indicate that GM2 (NeuGc) expression is directly regulated by the N-acetylgalactosaminyltransferase activity, the expression of the enzyme activity is regulated by an autosomal single gene and WHT/Ht is a mutant of the recessive homozygote which cannot express the enzyme activity in its liver. WHT/Ht does not develop any neurological symptoms but grows and breeds well. The brain ganglioside composition was proved to be identical to those in BALB/c brain. The result suggests that WHT/Ht has N-acetylgalactosaminyltransferase to convert GM3 (NeuAc) to GM2 (NeuAc) in its brain. It is a subject for further study to elucidate what kind of defect is involved in the GM2 (NeuGc) biosynthesis of WHT/Ht liver.

Animals↗
PubMed1984

Central monoamines and the death process time (antemortem time) during asphyxia. An experimental study in the mouse brain.

The changes of the brain monoamines, norepinephrine (NE), dopamine (DA), and serotonin (5-HT), during acute asphyxia, caused by strangulation, anoxia, and drowning, were studied in the mouse. In several asphyxiated animal groups significant linear correlation was found between the level of monoamines, NE, DA, and 5-HT, and the death process times or antemortem times were r = 0.50, 0.98 (P less than 0.05), and 0.57, respectively. It is concluded that the level of brain NE and DA increased in the mouse that died of asphyxia, and the level of 5-HT showed only an apparent decrease in anoxia groups as compared with the control group and showed a twice as high increase in drowning groups. Especially, there was a tendency that the longer the death process times or antemortem times, the higher was the level of DA.

Animals↗
PubMed1984

Krestin (PSK).

A polysaccharide preparation isolated from Coriolus versicolor (Fr.) Quél. of Basidiomycetes (PSK) predominantly consists of glucan and approximately 25% tightly bound protein. PSK was effective against various allogeneic and syngeneic animal tumors and has been given orally to cancer patients. Various suppressed or enhanced immune responses of tumor-bearing animals were restored to normal levels by the administration of PSK in the tumor models tested. The killer T cell activity was augmented in tumor-bearing mice by intraperitoneal or oral administration of PSK, and there was correlation between the PSK associated antitumor effect and the killer T cell activity. It was found that PSK competed with immunosuppressive substances isolated from tumor-bearing mice and that the intestinal immune system appeared to be modulated by oral administration of PSK. After oral administration of 14C- or 35S-labeled PSK to normal rats, it was found that small or large molecular substances appeared in the serum depending on the time elapsed after administration, an indication that large molecular size products were from the digestive tract.

Amino Acids↗
PubMed1984

Expression of GM1 and GD1a in liver of wild mice.

Wild mice are divided into two groups with different ganglioside compositions in the liver. Most Japanese and a few Chinese wild mice have GM2(NeuGc) as a major ganglioside, whereas all wild mice caught at other places distributed all over the world other than Japan and China express GM1(NeuGc) and GD1a(NeuGc) in addition to GM2(NeuGC). We recently reported that inbred strains of laboratory mice were also grouped into the same two types based on the ganglioside composition in the liver, and that the expression of GM1(NeuGc) and GD1a(NeuGc) was regulated by a gene located at the left outside the H-2 complex on chromosome 17 (Hashimoto, Y., Suzuki, A., Yamakawa, T., Miyashita, N., & Moriwaki, K. (1983) J. Biochem. 94, 2049-2054). The present study suggests that oriental wild mice would be a donor of a defective gene for expression of GM1(NeuGc) and GD1a(NeuGc) in mice of laboratory stocks which are commonly used for biochemical and immunological studies, such as C57BL/6, C57BL/10, BALB/c, DBA/2, C3H/He, and CBA mice.

Animals↗
PubMed1984

Genetically regulated expression of UDP-N-acetylgalactosamine: GM3(NeuGc) N-acetylgalactosaminyltransferase [EC 2.4.1.92] activity in mouse liver.

GM2 containing NeuGc was a major ganglioside in the liver of mouse strains such as BALB/c, DBA/2, C3H/He, and C57BL/10, whereas WHT/Ht mouse liver did not contain GM2(NeuGc) but contained GM3(NeuGc) as a major ganglioside. Since GM3(NeuGc) is a biosynthetic precursor of GM2(NeuGc), WHT/Ht liver was considered to lack the ability to synthesize GM2(NeuGc) from GM3(NeuGc) (Hashimoto, Y., et al. (1983) J. Biochem. 93, 895-901). In this study we measured the activity of UDP-N-acetylgalactosamine : GM3(NeuGc) N-acetylgalactosaminyltransferase in the liver of BALB/c, WHT/Ht, and their progeny. The transferase activity in the microsomal fraction of BALB/c liver was 2.10 +/- 0.32 X 10(-5) units/mg protein (means +/- S.D.), whereas no activity was detected in that of WHT/Ht liver, F1 hybrids between BALB/c and WHT/Ht expressed GM2(NeuGc) as well as the enzyme activity, the level of which was almost half that in BALB/c liver 1.10 +/- 0.12 X 10(-5) units/mg protein). The backcross generation of F1 to WHT/Ht segregated into two groups with respect to expression of GM2(NeuGc) and the transferase activity: 11 of the 21 mice analyzed expressed both GM2(NeuGc) and the transferase activity (1.28 +/- 0.18 X 10(-5) units/mg protein), whereas the rest expressed neither. These results suggest that the expression of GM2(NeuGc) is directly regulated by the activity of UDP-N-acetylgalactosamine: GM3(NeuGc) N-acetylgalactosaminyltransferase in mouse liver.

Animals↗
PubMed1984

Characterization of GM1b in mouse spleen.

Two GM1b gangliosides (IV-sialosylgangliotetraosylceramide) containing either N-glycolylneuraminic acid of N-acetylneuraminic acid at the terminal galactose of gangliotetraosylceramide were found in the ICR mouse spleen. Their structures were characterized by the behavior on thin layer chromatograms, sugar composition, susceptibility to sialidase and immunobinding activity toward anti-gangliotetraosylceramide antibody. The structure of GM1b containing N-glycolylneuraminic acid was further confirmed by methylation analysis. GM1 gangliosides containing either N-glycolylneuraminic acid or N-acetylneuraminic acid were also purified and characterized by thin layer chromatography, sugar analysis and sialidase treatment. As a result, the presence of four kinds of monosialoganglioside with a gangliotetraosyl core structure, GM1(NeuAc), GM1(NeuGc), GM1b(NeuAc), and GM1b(NeuGc), were found to exist in the ICR mouse spleen. These four gangliosides accounted for about 50% of the spleen monosialoganglioside content. Additional four gangliosides in the monosialoganglioside fraction were tentatively characterized as GM3(NeuAc), GM3(NeuGc), GM2(NeuGc), and sialosylneolactotetraosylceramide(NeuGc).

Animals↗
PubMed1984

Further studies on the red cell glycolipids of various breeds of dogs. A possible assumption about the origin of Japanese dogs.

Genetic polymorphism was observed in the sialic acid species constituting the terminal sugar residues of hematosides from dog erythrocytes. One was N-acetylneuraminic acid and the other phenotype was N-glycolylneuraminic acid, regulated by an autosomal dominant allele (Yasue, S., Handa, S., Miyagawa, S., Inoue, J., Hasegawa, A., & Yamakawa, T. (1978) J. Biochem. 83, 1101-1107). In this study we analyzed blood samples from 1,591 dogs of 36 breeds and demonstrated that the expression of N-glycolylneuraminic acid was limited to several breeds of oriental dogs in spite of its dominant nature. Moreover, the incidence of N-glycolylneuraminic acid was higher in native breeds of northern China, Korea and the southern part of Japan than in other oriental breeds. On the other hand, the Hokkaido-dog is unique in not expressing N-glycolylneuraminic acid. These results suggest that the native breeds in the southern part of Japan came from northern China via the Korean peninsula in contrast with indigenous breeds of the northern part of Japan.

Animals↗
PubMed1984

Dynamic analysis of water stress of sunflower leaves by means of a thermal image processing system.

This paper describes a method for measuring the temperatures of all regions of an intact leaf by using an infrared scanning thermometer at wavelengths between 8 and 14 micrometers combined with a digital image processing system. Pictures obtained every 2 minutes from leaves of sunflower (Helianthus annuus L. cv Large Russian) plants subjected to increasing water stress showed that water deficit develops first at the margins of leaves, accompanied by stomatal closure and increase in temperature. Finally, the temperature of the entire leaf rises 3 to 5 degrees C above that of nonstressed leaves. When transpiration resumed, it did so first at the leaf margins and these proceeded nonuniformly inward.The results of these experiments indicate that there are significant differences in the temperature and water status of different parts of a leaf. This makes it important to determine causes of such behavior and decide in what part of a leaf the temperature and water status should be measured. The thermo-imaging method can be useful in monitoring short term temperature changes occurring in leaves undergoing water, chilling, and other stresses.

Journal Article↗
PubMed1984

The hemodynamics and hemodynamic effects of indenolol in mild hypertension.

For clarifying the onset mechanism of essential hypertension, the hemodynamics in 9 mildly hypertensive men, mean age of 39.8 +/- 10.7 (mean +/- SD), was compared with 7 normotensive men, mean age of 39.8 +/- 10.7, by means of exercise echocardiography, and the effects of indenolol (administered 30 mg/day for 7 days orally to both groups) were studied. The interventricular septum and the left ventricular posterior wall were thickened in the mild hypertensives. No significant differences between the both groups were shown in the cardiac performance at rest and the cardiac index during exercise. The total peripheral vascular resistance was higher in the mild hypertensives than the normotensives during exercise. However, during exercise, the normotensives showed significant increases in the left ventricular end-diastolic dimension (LVDd) and the stroke index (SI); these changes were not significant in the mild hypertensives. After administration of indenolol, the significant increases in LVDd and SI during exercise were observed in the mild hypertensives. This study suggests that mild hypertensives with cardiac hypertrophy display a diminished Frank-Starling effect during exercise which may be attributed to the decreased left ventricular compliance due to cardiac hypertrophy and elevated afterload. Indenolol improved the Frank-Starling effect, which decreased in the mild hypertensives.

Adult↗