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Biomedical subjects

Y Morisawa

Publications and source records attributed to Y Morisawa.

At least 55 records · Page 3Linked to original sources
PubMed1979

Diurnal variation in large granulated vesicles in sympathetic nerve fibers of the mouse pineal--quantitative electron micrsocopic observations.

Quantitative electron microscopic studies of the sympathetic nerve fibers of the mouse pineal demonstrated a marked diurnal rhythm in the number of the large granulated vesicles of 80 to 150 nm diameter. The number of these vesicles showed its minimum at the middle and the end of the dark period and its maximum at the end of the light period, respectively. The large non-granulated spherical and elliptical vesicles were almost constant in number throughout the day.

Animals↗
PubMed1979

Effects of continuous lighting or continuous darkness on large granulated vesicles in sympathetic nerve fibers of the mouse pineal--quantitative electron microscopic observations.

The influence of continuous light or darkness on the large granulated vesicles in sympathetic nerve fibers of the mouse pineal was investigated by means of quantitative electron microscopic techniques. Continuous illumination at about 20 lux caused the disappearance of the diurnal rhythm in the number of the large granulated vesicles, followed by an accumulation of these vesicles. The diurnal rhythm of the large granulated vesicles was abolished in mice kept in continuous darkness for 7 days. These results suggest that the diurnal variation of the large granulated vesicles may be controlled directly by environmental light. Based on these findings, the relationships between small and large granulated vesicles were discussed.

Adrenergic Fibers↗
PubMed1978

Effects of acute cold exposure on the ultrastructure of the mouse pinealocyte.

Ultrastructural changes in pinealocytes were investigated qualitatively and quantitatively in mice exposed to low temperatures at 0 degree C or 5 degree C for 30 or 60 min. A quantitative estimation of the granulated vesicles of about 100 nm diameter in pinealocytes demonstrated that the number of these vesicles per pinealocyte in mice exposed to cold at 0 degree C or 5 degree C increased remarkably as compared with that of the controls. This finding indicates that cold stimuli may activate the formation of the granulated vesicles in pinealocytes. In mice exposed to cold at 0 degree C for 60 min, granulated vesicles were often found in gourps close to the plasma membrane of the pinealocyte cell bodies or processes, indicating the release of the vesicle content into the extracellular spaces. Additionally, the pinealocytes of the mice exposed to cold at 0 degree C for 60 min were characterized by the frequent occurrence of lysosome-like bodies and filaments. The development of these structures in response to severe cold may represent a depressed functional state of pienalocytes.

Animals↗
PubMed1978

Studies on anticoccidial agents. 12. Synthesis and anticoccidial activity of methyl-2(6)-nitro- and -3(5)-nitropyridinecarboxamides.

A number of methyl-2- and 3-nitropyridinecarboxamides have been synthesized. It has been established that the presence of at least one hydrogen atom, adjacent to the NO2 function, is important for anticoccidial activity and introduction of a methyl group to the adjacent position of the CONH2 function sometimes confers enhanced activity. Among the compounds herein, 5- and 6-methyl-2-nitropyridine-4-carboxamides possess optimal anticoccidial activity, being as potent as the parent compound.

Coccidiostats↗
PubMed1977

Studies on anticoccidial agents. 10. Synthesis and anticoccidial activity of 5-nitronicotinamide and its analogues.

5-Nitronicotinamide (1) was prepared from 5-bromonicotinoyl chloride by treatment with ammonia and then oxidation with fuming H2SO4 and 30% H202. 2-Cholor-, 2-alkoxy-2-benzyloxy,2-phenoxy-,2-alkylamino-, and 2-benzylamino-5-nitronicatinamides were also prepared via 2-chloro-3-cyano-5-nitropyridine. 2-Methyl-5-nitronicotinamide (2) was obtained from ethyl 2-methyl-5-nitronicotinate by treatment with ammonia; the 4-methyl analogue 3 was from 3-cyano-2,6-dihydroxy-4 methylpyridine by nitration, chlorination, and dechlorination, and the 6-methyl analogue 4 was prepared by transforming 2-chloro-3-cyano-6-methyl-5-nitropyridine to the corresponding amide, followed by dechlorination. Of these compounds, the 5-nitronicotinamide, the 2-methyl and 4-methyl but not the 6-methyl, analogue showed significant anticoccidial activity against eimeria tenella. N-Substituted analogues of 5-nitronicotinamide and 2-methyl-5-nitronicotinamide were prepared in a conventional manner and optimal anticoccidial activity was attained with their lower N-alkyl analogues, N-alkanoyl and -alkenoyl analogues, and N-aromatic acyl analogues together with these parent compounds.

Coccidiostats↗
PubMed1977

Studies on anticoccidial agents. 11. Synthesis and anticoccidial activity of nitropyridinecarboxamides and derivatives.

Of the nine nitropyridinecarboxamides, which are isomers of 5-nitronicotinamide, a potent anticoccidial agent, 2-nitropyridine-3, -4, -5-, or 6-carboxamides and 3-nitropyridine-4- or 6-carboxamides were prepared from the corresponding acids via the esters of the acid chlorides. 3-Nitropyridine-2-carboxamide was obtained from 2-methyl-3-nitropyridine by oxidation with SeO2, oximation, dehydration with Ac2O, and hydrolysis with H2SO4. 4-Nitropyridine-2-carboxamide was prepared from 2-cyano-4-nitropyridine by hydrolysis, and the 3-carboxamide analogue was obtained from 4-amino-3-cyanopyridine by oxidation with H2O2 and fuming H2SO4. Of these compounds 2-nitro- and 3-nitro- but not 4-nitropyridinecarboxamides were found to be active against Eimeria tenella. N-Substituted analogues of 2-nitro- and 3-nitropyridine carboxamides were also prepared in a conventional manner and optimal anticoccidial activity was attained with 2-nitroisonicotinamide and its N-alkanoyl, N-aromatic, and N-heterocyclic acyl derivatives.

Animals↗
PubMed1977

Functional relationships between sympathetic nerves and pinealocytes in the mouse pineal: quantitative electron microscopic observations.

Quantitative electron microscopic observations on the pineal gland of the mouse were made in order to demonstrate ultrastructural changes in response to various conditions of illumination in sympathetic nerve fibers as well as in pinealocytes and, thus, to establish some morphological correlates of a functional relationship between sympathetic nerves and pinealocytes. The diurnal change in the number of the small granulated vesicles (60 nm in diameter) in sympathetic nerve fibers of the mouse pineal is similar to that of the noradrenaline content in the rat pineal; increasing at night to reach the maximum level at the beginning of the light period of the day. A marked decrease of the small granulated vesicles seen after the onset of darkness may be correlated with a release of noradrenaline from the nerve fibers. Since the diurnal change in the number of the granulated vesicles (100 nm in diameter) and the glycogen content in the mouse pinealocytes closely resemble each other, the diurnal variation in the number of the granulated vesicles and the amount of glycogen may be influenced by a diurnal rhythm in the release of noradrenaline. The number of the granulated vesicles and the glycogen content in the pinealocytes show another striking similarity in that their remarkable increase is induced by continuous light for relatively short periods. It is speculated that light suppresses the release of noradrenaline from the nerve fibers and, thus, causes an increase of the glycogen content as well as the number of the granulated vesicles in the pinealocytes.

Animals↗
PubMed1975

Biochemical studies on sulfate-reducing bacteria. XIV. Enzyme levels of adenylylsulfate reductase, inorganic pyrophosphatase, sulfite reductase, hydrogenase, and adenosine triphosphatase in cells grown on sulfate, sulfite, and thiosulfate.

Sulfate-reducing bacteria, Desulfovibrio vulgaris, strain Miyazaki, were grown on either sulfate, sulfite, or thiosulfate as the terminal electron acceptor. Better growth was observed on sulfite and less growth on thiosulfate than on sulfate. Enzyme levels of adenylylsulfate (APS) reductase [EC 1.8.99.2], reductant-activated inorganic pyrophosphatase [EC 3.6.1.1], sulfite reductase [EC 1.8.99.1] (desulfoviridin), hydrogenase [EC 1.12.2.1], and Mg2+-activated ATPase [EC 3.6.1.3] were compared in crude extracts of these cells at various stages of growth. 1) The specific activity of APS reductase in sulfite-grown cells was only one-fourth that in sulfate-grown cells throughout growth. Thiosulfate-grown cells had an activity intermediate between those of sulfate- and sulfite-grown cells. 2) Cells grown on sulfite had lower specific activity of reductant-activated inorganic pyrophosphatase than cells grown on sulfate or thiosulfate. 3) The specific activity of sulfite reductase (desulfoviridin) was highest in sulfite-grown cells. The sulfite medium gave the enzyme in high yield as well as with high specific activity. 4) The specific activities of hydrogenase and Mg2+-ATPase were not significantly altered by electron acceptors in the growth medium.

Adenosine Monophosphate↗
PubMed1975

The epidemiological study on the correlation between serum lipids and cerebro-cardiovascular disease.

1. There were significant correlation between hyperlipidemia and obesity, hypertension, abnormal ECG and abnormal eyeground. 2. The incidence of cerebral hemorrhage was closely associated with hypertension but not with hyperlipidemia. 3. It was proved that hypertension with both hyper-Ch and hyper-TG was highly related to the development of cerebral infarction. 4. It seemed that the incidence of myocardial infarction and angina pectoris was related to hypertension with hyper-Ch. 5. Therefore, the present study suggested that the control of hypercholesterolemia and hypertriglyceridemia was useful for the prevention of cerebro-cardiovascular disease.

Adult↗