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P Laggner

Publications and source records attributed to P Laggner.

64 records · Page 4Linked to original sources

Investigation of the abnormal low-density lipoproteins occurring in patients with obstructive jaundice.

The abnormal lipoproteins of the density range 1.019-1.063g/cm3 occurring in the plasma of patients with obstructive jaundice were studied. Subfractionation of this density class by combined sodium phosphotungstate precipitation, ultracentrifugation, and column chromatography on hydroxyapatite and agarose gel yielded essentially three fractions: (1) lipoprotein-X, (2) A triglyceride-rich lipoprotein for which we propose the term lipoprotein-Y and (3) an abnormal lipoprotein, lipoprotein-B. Marked differences between these fractions with respect to electron-microscopic appearance, hydrated densities, chemical composition and immunochemical characteristics were observed. The protein moiety of lipoprotein-X consisted primarily of apolipoprotein-C and albumin. Lipoprotein-Y showed, in addition to apolipoprotein-C, the presence of apolipoprotein-B. The 'lipoprotein-B' fraction isolated from sera of these patients had higher triglyceride and free cholesterol contents than that of normal individuals and an unusually high content of apolipoprotein-C. The relative distribution of lipoprotein-X, lipoprotein-Y and 'lipoprotein-B' varied from patient to patient. The importance of considering the existence of lipoprotein-Y in screening patients for cholestasis by the lipoprotein-X test is discussed.

Cholestasis↗

Effect of cholesterol on vesicle bilayer geometry of choline plasmalogen and comparison with dialkyl-, alkylacyl- and diacyl-glycerophosphocholines.

Small unilamellar vesicles containing alkenylacyl-, alkylacyl-, dialkyl- or diacyl-glycerophosphocholine were prepared by sonication. Their size was determined from the average internal volume after chromatography on Sepharose 2B and from 31P-NMR linewidths. Alkenylacyl glycerophosphocholine (choline plasmalogen) was found to form the largest vesicles. By addition of 30 mol% cholesterol, the size of plasmalogen vesicles, but not of those containing the alkyl and acyl analogue lipids, was significantly increased. The presence of 50 mol% sterol led to highly increased vesicle sizes of alkylacyl, dialkyl and diacyl-glycerophosphocholine. Mixtures of plasmalogens with 50 mol% cholesterol did not form unilamellar vesicles upon sonication. Bilayer thickness and surface area per phospholipid molecule were determined by small angle X-ray scattering and measurement of partial specific volumes. There is little difference between alkenylacyl glycerophosphocholine and the corresponding diacyl-analog, whereas bilayers consisting of dioleoyl glycerophosphocholine are significantly thinner. Correspondingly their molecular surface area is by about 8% larger than that of the mixed-chain diradyl glycerophosphocholine, since the partial molar volumes are similar for all vesicles tested.

Cholesterol↗