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Biomedical subjects

N Ishihara

Publications and source records attributed to N Ishihara.

At least 127 records · Page 7Linked to original sources

Adsorption of mercury to urinary cells or particles.

Urine of a young healthy man was added with varying amounts of mercuric chloride, incubated for 10 to 375 min, and separated into supernatant solution and precipitate by centrifugation at 105,000 X g for 60 min. Percentage of mercury amount in precipitate increased with the increase of mercury amount added. But this adsorption of mercury to urinary cells or particles could not completely account for the amount of mercury in human urine reported (Suzuki and Shishido 1975). The hypothesis that desquamation of tubular cells is a route of urinary mercury excretion in man is still sustained.

Adsorption↗

Antitumor activity of macrophages induced by Corynebacterium liquefaciens.

Corynebacterium liquefaciens can induce a marked resistance to tumor cell (AH-7974) challenge in Donryu rats. This effect was also induced in T-cell-deficient athymic nude mice. The macrophages harvested from the peritoneal cavity of a rat injected with C. liquefaciens showed a marked inhibition of tumor growth in vitro. Therefore, the effector cells were assumed to be peritoneal macrophages. The time needed for activation of macrophages in vivo was within 3 to 5 days after injection of C. liquefaciens. Before or after this period, the peritoneal macrophages did not inhibit tumor cell proliferation. Furthermore, normal peritoneal macrophages were activated in vitro by C. liquefaciens and displayed remarkable antitumor activity. These results suggest that C. liquefaciens rendered the macrophages inhibitory to tumor cells even under T-cell depleted condition. On the other hand, in vitro antitumor activity of the activated macrophages disappeared completely after in vivo treatment of the peritoneal cavity of a rat with Trypan Blue, a lysosomal enzyme blocker. Resistance of the rat induced by C. liquefaciens to tumor cells was also abrogated by Trypan Blue treatment just 1 day before tumor cell inoculation. Trypan Blue blocked the acid-phosphatase (a marker enzyme of lysosomes) activity of the activated macrophages but it seemed not to affect other macrophage activities, at least in the following two points; normal macrophages treated with Trypan Blue had almost normal phogocytic function of India ink particles and, moreover, they could be rendered tumoricidal, same as normal macrophages, in vitro by C. liquefaciens.

Animals↗

Different behaviour of inorganic and organic mercury in renal excretion with reference to effects of D-penicillamine.

Inorganic and organic mercury was measured in the red cells, plasma, and urine of five laboratory workers to examine the effect of D-penicillamine. The workers had had no particular exposure to mercurials. Before and during administration of D-penicillamine, inorganic mercury levels in plasma were significantly correlated with those in urine or 24-hour urinary outputs, but no significant correlation was found for organic mercury. Administration of D-penicillamine enhanced 24-hour urinary output to a much greater extent in organic than inorganic mercury. All the organic mercury levels in blood, red cells, and plasma were increased by D-penicillamine. This contrasted with the decrease of inorganic mercury levels in plasma.

Adult↗

Biotransformation of methylmercury in vitro.

Inorganic mercury formation from methylmercury by the mouse liver and kidney was studied in vitro. With chopped liver or kidney, inorganic mercury was formed from added methylmercury, but when the tissue was homogenized, the activity was diminished. Equimolar addition of selenium had no effect on the reaction.

Animals↗

Lactate formation by the avian lung tissue.

The activities of formation of lactate and pyruvate were studied along with the development of chickens, Gallus domestica. In the lung the activity of lactate formation was highest in the embryo at 13th to 16th days of incubation, then the activity decreased as the development went on and continued to decrease even after the hatching. The change of the activity of pyruvate formation was almost parallel with that of lactate formation. On the other hand, in the liver the activities of formation of lactate and pyruvate remained constant and did not show such changes as observed for the lung.

Age Factors↗