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Biomedical subjects

B Albers-Jackson

Publications and source records attributed to B Albers-Jackson.

10 recordsLinked to original sources
PubMed1988

Ganglioside composition in human cataractous nuclei.

Gangliosides were isolated from human cataractous nuclei by solvent extraction, dialysis, and thin-layer chromatography and compared to gangliosides present in human whole normal and cataractous lenses. Three predominant gangliosides were tentatively identified as GM1, GM3, and GD1a, and several other resorcinol-positive components were observed in each of the sets of lens tissue. Thin-layer chromatographic patterns were similar, although some minor and possibly significant differences in band intensities were observed when chromatograms of gangliosides from cataractous nuclei and cataractous whole lenses were visually compared with those of whole normal lenses. Total ganglioside extracts were methanolyzed and the fatty acid methyl esters extracted with hexane and resolved by gas chromatography. Nervonic acid (C-24:1) content was increased in cataractous nuclei as compared to normal and cataractous whole lenses.

Cataract↗
PubMed1987

Incorporation of 14C-galactose into gangliosides of rabbit lens.

Rabbit lenses were incubated in organ culture with 14C-galactose for 6, 12 and 20 hours. Gangliosides were extracted using the Folch-Suzuki method, purified by dialysis and analyzed by thin-layer chromatography. Six radioactive bands, including the origin, were observed. Tentative identification of these bands as N-acetylneuraminylgalactosylglucosylceramide (GM3), N-acetylgalactosaminyl-(N-acetylneuraminyl)-galactosylglucosylceramide (GM2), galactosyl-N-acetylgalactosaminyl-(N-acetylneuraminyl)- galactosylglucosylceramide (GM1), N-acetylneuraminylgalactosyl-N- acetylgalactosaminyl-(N-acetylneuraminyl)-galactosylglucosylceramide (GD1a), N-acetylneuraminylgalactosyl-N-acetylgalactosaminyl-(N- acetylneuraminyl-N-acetylneuraminyl)-galactosylglucosylceramide (GT) was made by comparison with authentic standard gangliosides. Galactose incorporation into GM3 and GM2 increased during the first 12 hours but decreased during the period from 12 to 20 hours. GD1a and GT incorporated the greatest amount of label during the period from 12 to 20 hours. Incorporation of labeled galactose into GM1 was nearly constant during this time period. Specific activities for GM1, GM3 and GT were nearly the same at 6 hours and were about half those of GM2 and GD1a for the same time period.

Animals↗
PubMed1987

Lipid synthesis in the bovine lens.

Lipid synthesis was investigated in bovine lens in organ culture for 9 hours using 14C acetate as a precursor. The greatest incorporation occurred in phospholipid fraction with phosphatidyl choline being the major phospholipid labeled. Considerable activity was incorporated in the free fatty acid fraction, cholesterol and cholesterol intermediates. A comparison of the lipid synthesis in bovine mouse and rabbit lenses showed the rabbit lens to be the most active, the adult mouse lens to be the least active and the bovine and young mice to be intermediate in value.

Acetates↗
PubMed1985

Incorporation of 14C acetate into lipids of the ICR mouse lens.

Lenses from ICR mice 6, 12 and 35 days of age were incubated with 14C acetate in Medium 199 for 10 hours, and lenses from 35-day-old mice were also incubated for 18 hours. Acetate was incorporated into the phospholipid and free fatty acid fractions. Minimal radioactivity was incorporated into cholesterol. Phosphatidyl choline was the major labeled phospholipid. The longer incubation time resulted in a decrease in the total amount of label retained, indicating a fatiguing of the incubation system. The free fatty acids were extracted and subjected to analysis by gas chromatography. Although myristic acid (14:0) accounted for only 4% to 6% of the free fatty acids, it had the highest specific activity and the greatest percentage of incorporated radioactivity of the fatty acids for the 10-hour incubation period. The specific activity of all the fatty acids decreased dramatically after 18 hours incubation. Palmitic acid (16:0) had the greatest incorporation of label. It was suggested that exogenous acetate in the mouse lens preferentially entered a pool for energy production or storage rather than a pool for the synthesis of structural lipids as evidenced by minimal incorporation into cholesterol.

Acetates↗
PubMedDate not supplied

Incorporation of 14C acetate into the sterols of rabbit lens in organ culture.

Rabbit lenses were incubated in organ culture with 14C acetate for 3, 6, 12 and 20 hours and the nonsaponifiable fraction, composed primarily of sterols, was isolated. The incorporation of acetate into the nonsaponifiable fraction was linear for periods of 3 to 20 hours incubation. The nonsaponifiable fraction was subjected to thin-layer chromatography and 6 bands were observed. On the basis of Rf values, one band was tentatively identified as squalene, another as lanosterol and a third as a cholesterol-desmosterol mixture. The percentage of the radioactivity incorporated into the cholesterol-desmosterol band increased with incubation time. Conversely the percentage of the radioactivity incorporated into the squalene and lanosterol bands decreased with incubation time, indicating a precursor-product relationship.

Acetates↗
PubMedDate not supplied

Incorporation of 14C stearic acid in lens organ culture.

14C stearic acid was incubated in organ culture of rabbit lens for 6, 12 and 20 hours. Stearic acid did penetrate the lens and was incorporated into triacyl-glycerides and phospholipids. It also served as a carbon source for cholesterol synthesis. Individual fatty acids were isolated and radioactivity measurements were made. Incorporation of label was found in C12:0, C14:0 and C16:0 fatty acids, indicating de novo synthesis in the lens; incorporation was found in C16:1 and C18:1, indicating delta 9 desaturase activity, and incorporation was found in the fatty acids of 20 carbons or longer, indicating the presence of a fatty acid elongation system in the lens.

Animals↗
PubMedDate not supplied

Incorporation of 14C acetate into the phospholipids and fatty acids of rabbit lens in organ culture.

Lenses were cultured in Medium 199 containing 14C acetate for 3, 6, 12 and 20 hours. There was a linear increase in incorporation into the total lipids with time. The total lipid extract was subjected to two-dimensional chromatography and incorporation into the individual classes of lipids was measured. For all time periods approximately 70% of all incorporated radioactivity was seen in the sterol and phosphatidyl choline (PC) fractions. Incorporation was observed in phosphatidyl ethanolamine (PE), aldehydes of PC and PE plasmalogens, phosphatidyl inositol (PI), PC plasmalogens, PE plasmalogens, sphingomyelin (SM), phosphatidic acid (PA) and phosphatidyl serine (PS). The fatty acids of the total lipids were methylated and subjected to gas chromatography, and individual fatty acids were collected. The greatest incorporation occurred in palmitic acid (16:0) and myristic acid (14:0) with minor amounts in lauric acid (12:0). These are the major products of de novo synthesis. The remainder of the radioactivity appeared in fatty acids 18 carbons or longer, which are the products of an elongation mechanism.

Acetates↗