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Biomedical subjects

Y J Guo

Publications and source records attributed to Y J Guo.

67 records · Page 4Linked to original sources

Modulating activity of B lymphocytes on haemopoiesis (II)--the purification of proliferation amplifying factor (PAF).

In recent years we have done a series of observations on the haemopoietic modulation effects of lymphocytes. Now we report here, for the first time, the purification of a modulating factor (proliferation amplifying factor, PAE) with affinity chromatography and HPLC from supernatant conditioned by a lymphoma cell line M12.4.1. RAF exhibits on SDS-PAGE only one band, the molecular weight is about 31,000, the specific activity is 20,000 times that in the conditioned medium. It may provide a direct evidence that the B lymphocyte also possesses some haemopoietic modulation effects.

B-Lymphocytes↗

Effects of some alcohols on the conformation of mitochondrial H+-ATPase complex and F1-ATPase from pig heart.

The conformations of the H+-ATPase complex and F1-ATPase in low concentrations of methanol, ethanol, n-propanol, iso-propanol and t-butanol were studied by circular dichroism. For F1-ATPase, all but methanol first increased and then decreased the circular dichroism magnitude of helical bands as the alcohol concentration was increased. With ethanol, n-propanol, iso-propanol and t-butanol, the alpha-helix content reached a maximum at about 5% alcohol and began to decrease at 10%. The content of beta-sheet showed the opposite effect, reaching a minimum at 5% and increasing slightly at higher concentrations. None of the alcohols studied had a significant effect on the conformation of the H+-ATPase complex. This difference implies that the alcohols had a greater effect on free F1-ATPase than on the membrane-bound F1-ATPase. The hydrophobic protein F0 and the membrane lipids in the H+-ATPase complex may stabilize and protect F1 from the effects of the alcohols.

1-Propanol↗

Effects of low-level lead on retinal ganglion sustained and transient cells in developing rats.

Neonatal rats were exposed to lead from parturition to weaning via the milk of dams drinking 0.2% lead acetate solutions. The alterations in the excitability and temporal response properties of retinal ganglion cells in adult rats (90 days) following developmental lead exposure were studied. The results of this investigation demonstrated that the lead exposure in neonatal rats caused an increase in excitability, and a decrease in optimal temporal frequency, bandwidth at half amplitude, temporal resolution, and response phase of the retinal ganglion cells in adult rats. Compared with the sustained cells, the transient cells had a much greater alteration in excitability and temporal response properties.

Action Potentials↗

Serum and egg yolk IgG antibody titers from laying chickens vaccinated with Pasteurella multocida.

Through determining the serum and egg yolk antibody titers in immunized laying hens to Pasteurella multocida regularly, the growth-decline trend of the egg yolk antibody levels was found to be similar to that of the serum antibody levels (r = 0.94), but the growth and decline of the egg yolk antibody seemed to be delayed 3-6 days compared with that of the serum antibody, and the egg yolk antibody titers were generally lower than those of the serum antibody (P < 0.01). Serum and egg yolk antibody levels declined 3 and 6 days, respectively, after booster immunizations. The higher the antibody levels were before booster immunization, the more they declined.

Animals↗