Biomedical subjects

I V Fuki

Publications and source records attributed to I V Fuki.

25 records · Page 2Linked to original sources

PubMed1988

[An immunoenzyme method of diagnosing familial hypercholesterolemia].

A new modification of enzyme immunoassay: enzyme-linked-immunoreceptor assay (ELIRA)--was used to study the activity of LDL-receptors on cultured fibroblasts from 10 patients with elevated plasma cholesterol levels, IHD, accelerated atherosclerosis and xanthomatosis. Four patients were found to have heterozygous form of familial hypercholesterolemia. We have also shown that the results of ELIRA were quantitatively similar to the data obtained by traditional radioisotopic method. This indicates that simple, rapid, inexpensive ELIRA can be used for diagnosis of FH.

Cell Membrane↗

PubMed1988

[Physico-chemical and functional characteristics of a subfraction of low-density lipoproteins isolated by ion-exchange column chromatography].

Fractionation of human blood plasma low density lipoproteins (LDL) was performed by ion-exchange chromatography, using a linear NaCl gradient. It was shown that the binding of LDL subfractions eluted with a low ionic strength buffer (i.e., containing the particles with a lower negative charge) to B, E-receptors of fibroblasts was more effective than that of subfractions eluted with a high ionic strength buffer (i.e., containing the particles with a higher negative charge). The LDL particles with a lower negative charge had lower values of flotation coefficients (according to analytical ultracentrifugation data), smaller dimensions (according to gradient gel electrophoresis data) and a lower phospholipid/protein ratio (w/w). The experimental results suggest that LDL subfractions having different electrical parameters of the particle surface also differ in other physicochemical properties and seem to play a different role in atherogenesis.

Cells, Cultured↗

PubMed1986

Enzyme immunoassay of the receptors for modified low density lipoprotein.

Mouse macrophages (line J 774) were incubated with monospecific goat anti-low density lipoprotein antibodies, which were conjugated to horseradish peroxidase (AB-HRP). Addition of low density lipoprotein (LDL) modified by treatment with malondialdehyde to cultures of these cells resulted in a dose-dependent increase in the amount of cell-associated enzyme activity. The concentration curve was hyperbolic with half-saturation of modified LDL at a concentration of about 3 micrograms/ml. This effect was completely blocked by polyinosinic acid and was not observed in experiments with human fibroblasts, which do not exhibit high affinity binding sites that recognize chemically modified LDL. Our data indicate that receptor-mediated endocytosis of AB-HRP in the presence of native or modified LDL may be used as very simple, efficient, and sensitive assay for investigation of the scavenger receptors for modified LDL.

Animals↗

PubMed1986

Apolipoprotein B release from activated human platelets.

Apolipoprotein B (apoB) release from activated washed human platelets was measured by enzyme-linked immunosorbent assay (ELISA) using monospecific rabbit antibodies to human low density lipoprotein (LDL). Activation of platelets with thrombin, Ca2+-ionophore A23187 or stable analogue of prostaglandin endoperoxides U46619 stimulated release of approximately 20 ng apoB/10(8) platelets. Thrombin-induced apoB release was inhibited by the prostacyclin analogue carbacyclin. Dose-response curves of thrombin stimulation and carbacyclin inhibition of apoB and beta-thromboglobulin (beta-TG) release were very similar. Treatment of platelets with heparin did not remove significant amounts of apoB or affect the subsequent release of apoB induced by thrombin. The results of density gradient ultracentrifugation indicated that most of the apoB was released in the LDL density range. These data suggest that human platelets contain immunoreactive apoB, which can be released during platelet activation.

Apolipoproteins B↗

PubMed1985

Cholesterol can stimulate secretion of apolipoprotein B by cultured human hepatocytes.

During a 5 day cultivation of human hepatocytes in a primary culture the secretion of apolipoprotein B was measured by enzyme-linked immunosorbent assay. Density-gradient ultracentrifugation demonstrated that the majority of the secreted apolipoprotein B was associated with the very-low-density lipoprotein fraction. Exposure of the cells to cholesterol (5-100 micrograms/ml) resulted in a dose-dependent increase in apolipoprotein B secretion rate.

Adult↗

PubMed1985

Enzyme-linked immunoreceptor assay of low-density-lipoprotein receptors.

A new modification of enzyme immunoassay-enzyme-linked-immunoreceptor assay (ELIRA) was used to study low-density lipoprotein (LDL) binding by cultured human skin fibroblasts. Time-course and concentration curves obtained by this method were typical of LDL binding by cultured fibroblasts. According to ELIRA, fibroblasts bound native LDL 10-20 times more effectively than reductively methylated LDL or native LDL in the presence of heparin. Receptor-specific Km and maximum binding capacity calculated from these data were 5.4 micrograms/ml and 177.5 ng/mg of cell protein, respectively. Receptor-specific Km and maximum binding capacity for surface 125I-LDL binding measured in the same experiment were 11.0 micrograms/ml and 138.0 ng/mg of cell protein. Incubation of cells with isolated LDL or with unfractionated serum containing the same amount of apoB yielded similar concentration curves for lipoprotein binding. These data indicate that the ELIRA can be used for investigation of receptor-mediated lipoprotein binding without purification of lipoproteins.

Apolipoproteins B↗

PubMedDate not supplied

[Physico-chemical properties of low density lipoproteins isolated in an equilibrium density gradient].

The tryptophanyls of total low density lipoproteins (LDL) (1.006-1.063 g/ml) from coronary heart disease (CHD) patients and subjects without CHD signs had different accessibility to fluorescence quenchers (I-and acrylamide). LDL were separated into subfractions in equilibrium density gradient. The coefficient of extinction , quantum yield and other spectral characteristics of LDL intrinsic fluorescence, rotational mobility of maleimide spin labels and fatty acid spin probe were different in LDL subfractions from healthy subjects. LDL subfractions with hydrated density 1.045-1.05 g/ml bound to B,E-receptors of cultured fibroblasts more effectively than did subfractions with density 1.01-1.03 g/ml. Structural differences of apo-B in the particles with different lipid to protein ratio are supposed.

Apolipoproteins B↗