PubMed Health⌕ Search

Biomedical subjects

G Lercker

Publications and source records attributed to G Lercker.

24 records · Page 2Linked to original sources
PubMed1986

Effect of ethanol intake on human erythrocyte membrane fluidity and lipid composition.

Erythrocyte membrane fluidity was evaluated in chronic alcoholic patients without any liver alteration, assuming different daily ethanol amounts, and in normal subjects and related to ghost fatty acid and total lipid composition obtained by high resolution gas chromatography. Erythrocyte membrane fluidity was significantly increased in a dose dependent manner in chronic alcoholic patients respect to normal subjects. This real fluidizing effect of ethanol "in vivo" was attributed mainly to a significant increase in the polyunsaturated fatty acids amount in patient ghosts in comparison with control subjects. On the other hand the cholesterol/phospholipid ratio was not significantly affected by chronic ethanol assumption.

Adult↗
PubMed1984

Analysis of phospholipids in cow's milk by high-temperature injection gas chromatography and high-performance liquid chromatography.

An investigation of the high-temperature injection (350 degrees C) gas chromatographic behaviour of standards of various classes of phospholipids has elucidated certain characteristic fragments ("tracers") in the pyrogram of each class. Under these conditions of pyrolysis of the phospholipids, a natural mixture of such substances (extracted and purified from cows' milk) has provided evidence for the same "tracers" as for the standards. Analogous results were obtained with a more representative specimen of cows' milk of various breeds grown in areas of different altitudes. The content of fatty acids in phospholipids, tested on each class (separated by means of radial compression high-performance liquid chromatography from polar lipids of milk) appeared to be relatively similar for all the phospholipid classes, and over half the content consisted of unsaturated fatty acids. The major component was delta 9-octadecenoid (oleic) acid.

Animals↗
PubMedDate not supplied

Green tea extracts can counteract the modification of fatty acid composition induced by doxorubicin in cultured cardiomyocytes.

Doxorubicin cardiotoxicity is associated with the generation of free radicals, and involves not only lipid peroxidation but also a decreased biosynthesis of highly unsaturated fatty acids, leading to significant modification in cardiomyocyte fatty acid composition. We have evaluated whether naturally occurring antioxidants could counteract this side-effect. Green tea is an excellent source of catechins; we supplemented cultured rat cardiomyocytes with different green tea extracts to relate their catechin content and composition to their ability in protecting cells against doxorubicin-induced damage. The determination of total lipid fatty acid composition, of conjugated diene production (indicator of lipid peroxidation), and of lactate dehydrogenase release revealed that supplementation with tea extracts could counteract significant modifications in the fatty acyl pattern due to doxorubicin exposure, although to different extents. These differences could be ascribed to the different total catechin content and to qualitative differences among the tea extracts, determined by HPLC analysis.

Alkadienes↗
PubMedDate not supplied

Oxisterol determination in selected coffees.

The main aim of green-coffee processing techniques, such as decaffeination and roasting, is always to maintain a very high level of quality in taste and flavor, the beverage's most important characteristics to consumers. Oxidative alterations of coffee lipids, which can occur in roasting, exert a very marked influence on these quality traits. Determining the extent of oxidation thus can provide an indication of the product's potential shelf-life and reveal traces of any newly-formed oxidative products that might prove nutritionally unsafe. Yet, while much attention has recently been focused on certain by-products induced by cholesterol oxidation and their proven toxicity as risk factors in atherosclerosis and cancer, oxidated phytosterols have largely gone unnoticed, being considered along with beta-sitosterol as not very dangerous in that neither is absorbed by the intestinal tract. The present study investigates the substances derived from phytosterol oxidation (oxisterols) in samples of regular and decaffeinated commercial coffees. The findings show that oxisterols were absent in some samples and that the traces of oxidate phytosterols detected in others were well below the threshold considered as toxicologically active.

Coffee↗
PubMedDate not supplied

[Saturated fatty acids determination by GLC after TLC separation (author's transl)].

The determination of fatty acid composition of oils and fats by conventional GLC on polar columns gives satisfactory results for most of the applications. Higher precision is, however, desirable when the content of minor components is of interest. A typical example is the quantitative determination of the percentage of peanut oil in a seed oil mixture, on the basis of the content of lignoceric acid (n-C21). Lignoceric acid, wich is containen in peanut oil in the amount of 1-2%, shows, on polar columns, a very long retention time and, owing to its low percentage, flat and non well measurable peaks. A method was therefore developed which allows an accurate determination of all saturated fatty acids, particulary of those with high molecular weight. The method is based on the separation of satured fatty acids by argentation TLC followed by GLC determination on non polar columns.

Arachis↗