The actions of D- and D,L-homocysteate (DH and DLH) on CA3 neurons were studied in thin sections of the guinea pig hippocampus. DH and DLH administered to the stratum radiatum induced large depolarizations in CA3 neurons. The responses to DH and DLH were accompanied by increases in membrane conductance. The amplitudes of the responses increased and decreased, respectively, during tonic hyperpolarizing and depolarizing currents. In neurons injected with Cs+, these responses were reversed in polarity at membrane potentials of -13 to -19 mV. These results indicate that receptors for homocysteate in the hippocampus have different properties from those found in the spinal cord and are quite similar to glutamate receptors.

Animals↗

PubMed1982

An increase in Sendai virus-induced cell fusion of erythrocytes infected with Plasmodium chabaudi.

The extent of cell fusion induced by Sendai virus was examined in erythrocytes infected with Plasmodium chabaudi. An increase in cell fusion of erythrocytes with Ehrlich tumor cells and of erythrocytes with erythrocytes was observed with the infected erythrocytes. However, agglutination by the virus was not changed between erythrocytes of normal and malarial mice. These results indicate that the increase in cell fusion occurred in the process of membrane fusion, suggesting that some membrane property of Plasmodium-parasitized erythrocytes is changed in terms of Sendai virus-induced cell fusion.

Animals↗

PubMed1982

Functional aberration of T cell subsets in patients with Behçet's disease.

Abnormalities of concanavalin A-induced suppressor activity and autologous mixed lymphocyte reaction (which is part of the regulatory role of T cells on lymphocyte functions) were observed in patients with preactive Behçet's disease. However, both the functions returned to normal when the patients entered an active or inactive phase of disease. Thus, a diminution of suppressor function appears to be necessary for the initiation or potentiation of autoimmune and/or inflammatory abnormalities in Behçet's disease. Results of studies of T cell subsets and their functional analysis in patients with preactive Behçet's disease provide further evidence in support of this hypothesis.

Adult↗

PubMed1982

Effects of methyl-B12 on the in vitro immune functions of human T lymphocytes.

Studies were performed using an in vitro assay system to determine whether or not methyl-B12 could affect human T-cell function. When T cells were stimulated with phytohemagglutinin and allogeneic B cells, methyl-B12 did not enhance T-cell proliferation. In contrast, remarkable enhancing effects of methyl-B12 on the proliferative response to concanavalin A (Con A) and autologous B cells at suboptimal concentrations were observed, ranging from 0.1 to 10 micrograms/ml. Concentrations of methyl-B12 sufficient to enhance cellular proliferation were able to enhance the activity of helper T cells for immunoglobulin synthesis of B cells by pokeweed mitogen. Furthermore, the presence of methyl-B12 significantly potentiated the induction of suppressor cells in Con A-activated cultures. These results suggest that methyl-B12 could modulate lymphocyte function through augmenting regulatory T-cell activities.

Antibody-Producing Cells↗

PubMed1982

The biological activity of alpha-1-antichymotrypsin: the change of chymotrypsin-inhibitory and immunoenhancing activities by heat treatment.

The relationship between chymotrypsin-inhibitory and immunoenhancing activity of alpha-1-antichymotrypsin was studied. alpha-1-Antichymotrypsin was treated at 50 degrees C, 55 degrees C or 60 degrees C for 15 min. It was found that antichymotryptic activity was reduced by half when alpha-1-antichymotrypsin was heated at 55 degrees C and was not detected at all when heating was carried out at 60 degrees C. alpha-1-Antichymotrypsin which was heated at 60 degrees C did not form a complex with chymotrypsin, but became a substrate for chymotrypsin. The effect of native and heated alpha-1-antichymotrypsin on antibody response was studied in mice. alpha-1-Antichymotrypsin increased the number of anti-sheep erythrocytes antibody producing cells even when it was heated at 60 degrees C. Circular dichroism and single radial immunodiffusion were used to detect conformational changes. Circular dichroism in the region of side chain absorption showed that the intensities of the spectra at 296, 284, and 265 nm decreased with a rise in temperature from 50 to 60 degrees C. In single radial immunodiffusion analysis, alpha-1-antichymotrypsin did not form a halo after being heated at 60 degrees C. In conclusion, when alpha-1-antichymotrypsin was heated at 60 degrees C, the immunoenhancing activity remained intact while the antichymotryptic activity was lost with the conformational change.

Adjuvants, Immunologic↗

PubMed1982

Antigen-induced decrease of salicylic acid absorption from the small intestine in actively immunized rats.

Rats were intraperitoneally immunized with bovine gamma-globulin (BGG) emulsified in incomplete Freund's adjuvant. Intestinal absorption of salicylic acid from the rat small intestine was examined by means of in situ recirculation technique. The disappearance of salicylic acid from the luminal solution was significantly decreased in rats challenged intravenously with BGG compared to saline as control. A significant decrease in absorption of salicylic acid was noted in rats immunized twice and three times, but not in rats immunized only once. The effect was maintained for at least 5 weeks after the third immunization, whereas it disappeared within 10 weeks. In normal rats, the decreased absorption of salicylic acid by the intravenous challenge with BGG was hardly observed at all. These findings suggest that the intestinal absorption of salicylic acid may be affected by systemic anaphylaxis in actively immunized rats.

Anaphylaxis↗

PubMed1982