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Biomedical subjects

M L Blank

Publications and source records attributed to M L Blank.

At least 109 records · Page 6Linked to original sources
PubMed1975

A method for the quantitative determination of glycerolipids containing O-alkyl and O-alk-1-enyl moieties.

We have developed a spectrophotometric procedure, based on a combination of established methods, for the quantitative determination of aklyl and alk-1-enyl (plasmalogens) ether-linked glycerolipids. It depends upon the release of alkylglycerols and alk-1-enylglycerols from phospholipids by phosphlipase C (Bacillus cereus) followed by saponification or by Vitride reduction the phospholipids; aldehydes are subsequently formed and measured colorimetrically after reacting them with a fuchsin reagent. The total alkyl and alk-1-enyl content of glycerolipids is determined oxidation of the sample withperiodate to form aldehydes and alkylglycolic aldehydes. The O-alk-1-enyl lipid content is determined on a separate sample by measuring the aldehydes produced after acid hydrolysis. The quantity of O-alkyl lipids is calculated from the difference between the values obtained for the total ether-lipid content and that of the O-alk-1enyl lipid content. Alternately, direct determination of alk-1-enylglycerols and alkylglycerols can be made if these hydrolytic products are first separated by thin-layer chromatography.

Animals↗
PubMed1975

Analysis of tumor-associated alkyldiacylglycerols and other lipids during radiation-induced thymic leukemogenesis.

Lipid composition of thymuses investigated during the development of thymic leukemogenesis induced by exposing C57BL/6J mice to gamma radiation led to the following conclusions. 1. Alkyldiacylglycerols, a class of lipids that are generally elevated in most neoplastic tissues, occurred only in small quantities (less than 1% of the total lipids) in the thymuses of both control and irradiated mice. However, we found a 3- to 8-fold increase in this fraction in thymic tumors of mice at 5 mo after irradiation when compared to controls of similar age. However, the small quantity of this lipid class in thymic leukemia and the fact that similar levels were found in some samples of involuted thymuses of mice 3 days after irradiation, suggests to us that the level of alkyldiacylglycerols is not sufficiently specific or sensitive for detecting early stages of thymic leukemogenesis. 2. Thymuses 3 days after irradiation and leukemic thymuses contain 2- to 3-fold greater quantities of cholesterol esters than control thymuses. No major differences were found in the distribution of acyl moieties in the cholesterol esters of the various thymus samples from the same aged mice except that in thymic tumors the quantity of 18:1 esters was increased by about 25% over that of the controls. The apparent lack of specificity of increased cholesterol esters for neoplasia indicates that its measurement would not provide a suitable indicator of early neoplastic transformation. 3. Acyl composition of the triacylglycerols of thymuses revealed an increase in the 18:1 and a decrease in the 18:2 acids at 3 days after irradiation when compared to the same aged controls. However, thymic tumors occurring at 5 mo after irradiation contained less 14:0, 16:0, and 16:1 acids and increased amounts of 18:1 and 18:2 acids esterified as triacylglycerols compared to controls. The fatty acid distribution in the phospholipid fraction of thymuses was not altered by the appearance of leukemia.

Animals↗
PubMed1972

Isolation and identification of an alkyldiacylglycerol containing isovaleric acid.

We have isolated and identified a unique subclass of alkyldiacylglycerols from the pink portion of the harderian gland of the New Zealand white rabbit. Using chemical, enzymic, chromatographic, and physical procedures, the lipid class has been identified as 1-alkyldiacylglycerol containing 1 mole of isovaleric acid. More than 50% of the O-alkyl moieties consist of 16:0 and 18:0 carbon chains, whereas the other major O-alkyl moieties are 15:0 and 17:0 branched chains ( approximately 30%). The long-chain acyl groups of the alkyldiacylglycerol subclass consist primarily of saturated fatty acids (60% 16:0 and 30% 18:0) and a small amount of branched-chain fatty acids ( approximately 5%), whereas the 3-position appears to be occupied by isovaleric acid.

Aluminum↗
PubMed1971

On the analysis of long-chain alkane diols and glycerol ehters in biochemical studies.

The chromatographic behavior of 1,2-, 1,3-, 1,4-, and 1,12-long-chain alkane diols and 1-O-alkylglycerols and their derivatives has been compared. Thin-layer chromatography on Silica Gel G gives poor separations of the 1,2-, 1,3-, and 1,4-alkane diols, O-alkylglycerols, and some of their isopropylidene derivatives. However, gas-liquid chromatography on 10% EGSS-X (coated on 100-120 mesh Gas-Chrom P) resolves the isopropylidenes of the alkane diols and O-alkylglycerols. We also document the formation of 1,3-alkane diols (after LiAlH(4) reduction) from 1-(14)C-labeled fatty acids incubated with mitochondrial fractions from heart and liver of rats. The labeled 1,3-alkane diol was identified by gas-liquid chromatography of its isopropylidene derivative and by its behavior after periodate oxidation. These results serve to caution investigators in the glycerol ether field against incorrect interpretation of data obtained on the incorporation of labeled fatty acids into alkyl ether bonds of glycerolipids. The methodology described points out a technique for distinguishing several types of alkane diols from O-alkylglycerols.

Aluminum↗