ABSTRACT
The effects of GPA, anti-GPA IgG, ?1acid glycoprotcin (?1-AGP), ovomucoid (OM) and wheat germ agglutinin (WGA) on the invasion of erythrocytes by P. falciparum were obseryed in vitro. GPA, anti-GPA IgG and WGA at low concentrations had obviously inhibitory effects on thc invasion. There were hyperbolic relationships between the concentrations of these inhibitors and their inhibition rates. OM, ?1-AGP and non-spccific anti-serum had no obvious effect on the invasion. It is confirmed for the first time from the biological characteristics of receptor-ligand interaction that thc combination of GPA with P. falciparum merozoites has high spccificity, high affinity with a tendency to sa-turation and can produce specific biological effects.
ABSTRACT
The carbohydrate and lipid contents and Ca2+-Mg2+ ATPase activity of erythrocyte membrane were studied in 10 patients with DMD. The results demonstrated that the sialic acid content was markedly decreased, and the neutral sugar content normal. The cholesterol was significantly increased, but the phospholipids unchanged, resulting in a significantly reduced P/C ratio. The activity of Ca2+-Mg2+ ATPase elevated markedly. The study suggests that the erythrocyte membranes with DMD are altered both in composition and function.
ABSTRACT
Fresh healthy human erythrocytes were treated by four kinds of bile acid solutions (DC, GDC, C, and GC) at physiological and pathological concentrations of human plasma, and the membrane proteins, enzyme activities and permeability of cations were observed. The results showed that some components of the membrane cytoskeleton proteins disappeared, the activities of total ATPase and Gr-ATPase were distinctly increased with the increasing of bile acid concentrations, the activity of the membrane acetylcholinesterase was decreased with the increasing bile acid concentrations, the permeability of cations was increased with the increasing bile acid concentrations. The effect of the dihydroxy bile acids more stronger than that of the trihydroxy bile acids.
ABSTRACT
A simple and accurate method for the determination of total bile acids in serum by spectrofluorometry was described. The assay was based on the fact that free and conjugated bile acids tested after treatment with concentrated sulfuric acid, all gave the approximately equal fluorescence intensity at 500 nm, under 470 nm light excitation.
ABSTRACT
Electrophoretic-purified human glycophorin A (GPA) was used to produce its derivatives: (1) glycopeptides were separated and purified from GPA by trypsin digestion; (2) preparation of GPA-antibody and GPA glycopeptide-antibody; (3) preparation of deglycosylated GPA (dGPA); (4) incorporating GPA or dGPA into human RBC membrane lipids to form two kinds of liposomes. The products described above were used to test Plasmodium falciparum FCC1/HN merozoites for their ability to invade human erythrocytes. It was found that GPA-liposomes were able to bind with merozoites and dGPA-liposomes had a negative reaction. GPA, GPA glycopeptide, GPA-antibody, GPA glycopeptide-antibody and GPA-liposome all had the effect to hinder the invasion of merozoites into human erythrocyte while dGPA-liposome had no such an effect.
ABSTRACT
The activity of erythrocyte membrane Na+-K+ATPase was determined from 43 patients with essential hypertension and 10 normotensive controls. Erythrocyte membrane preparation was obtained by washing after hypotonic hemolysis and repeating high speed centrifugal sedimentation. Ouabain was used as a specific inhibitor in Na+-K+ATPase assay. A significantly decreased activity of erythrocyte membrane Na+-K+ATPase was found in these patients of hypertension. Although their clinical manifestations were improved, there were no differences in Na + -K+ATPase activity between treated with Ligusticum Wallichii Hort and untreated groups. The mechanisms involved in these changes were discussed.
ABSTRACT
17B~estradiol. Displacement experiments showed that when RU38486 concentration reached 100~280-fold that of [3H]corticosterone, it began to inhibit [3H]corticosterone binding, while low concentration of RU38486 had no inhibitory effect.