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Biomedical subjects

G Z Yang

Publications and source records attributed to G Z Yang.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Studies on antipeptic ulcer agents: the synthesis and structure-activity relationship analysis of heterocycle aldehyde (thio) semicarbazones and acyl hydrazones].

Twenty-eight condensation products of heterocycle-alpha-carboaldehydes with N-aminooxazolidones, semicarbazides, thiosemicarbazides, aminoguanidines, aromatic hydrazides and benzoxycarbonyl hydrazide were synthesized so as to deduce the antiulcer pharmacophore or fragment of furazolidone(I), the prototype, which shows therapeutic efficacy for patients with gastric ulcer. Analysis of the SAR of the compounds indicate that the substitution of furan, thiophene, pyrrole and N-methyl pyrrole rings for the 5-nitrofuran and the cleavage of the oxazolidone ring obtain the activity to some extent. The necessary electronic density of carbonyl group of compounds is of importance. A lead structure, therefore, is derived for further optimization.

Animals↗
PubMed1989

[Studies on antipeptic ulcer agents: the synthesis and QSAR analysis of heterocycle aldehyde N4-substituted phenyl(thio)semicarbazones].

Forty-five condensation products of furan-, pyrrole-, and N-methyl pyrrole-alpha-carboaldehyde with N4-3-or 4-substituted phenyl semicarbazides and thiosemicarbazides were designed and synthesized to optimize the antiulcer activity. Quantitative structure-activity relationships reveal that in the series of semicarbazones increase in hydrophobicity of molecules and introduction of electron-repelling groups onto the phenyl ring raise the antiulcer activity; Generally, the activity of semicarbazones is higher than that of the corresponding thiosemicarbazones. The large spans between activity and toxicity of compounds No. 17 and 30 led to further investigation of pharmacological actions.

Animals↗
PubMed1987

Immunoregulatory effect of neocortex in mice.

Immune responses were analyzed after neocortex ablation in mice. The neocortex ablations were performed in inbred mice on the left (ALN) or right hemisphere (ARN) separately. Two months later immunological parameters were tested. The results showed that the mitogenesis induced by Con A, natural killer cell (NK) cytotoxicity, production of IL-1 and IL-2 as well as the reactivity to IL-1 were all suppressed in ALN mice but stimulated in ARN mice compared to sham-operated controls. The primary antibody response to sheep red blood cells (SRBC) was also enhanced in ARN but not ALN mice. These results indicate that there may be a different regulatory effect on the immune system mediated by the different brain hemispheres, a phenomenon named lateralization of brain.

Animals↗
PubMed1986

Acetylcholine receptor antibody in patients with myasthenia gravis.

The determination of acetylcholine receptor antibody (AChR Ab) titer by an enzyme-linked immunosorbent assay (ELISA) in patients with myasthenia gravis was introduced. The optimal conditions were determined by chequerboard determination. The specificity was confirmed by inhibition tests. The sensitivity is 9 p mole. The comparison of AChR Ab titers among 49 myasthenic patients, 19 non-myasthenic neurological patients and 20 healthy blood donors has shown that it is a highly sensitive, specific, reproducible, rapid, simple and inexpensive method for determining AChR Ab and that it is highly valuable for the diagnosis of myasthenia gravis.

Antigen-Antibody Complex↗