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C C Sweeley

Publications and source records attributed to C C Sweeley.

140 records · Page 8Linked to original sources
PubMed1967

Quantitative determination of the neutral glycosyl ceramides in human blood.

A method is described for the qualitative and quantitative estimation of four neutral glycosyl ceramides from human plasma and erythrocytes. Total lipids extracted from 50 ml of plasma or packed erythrocytes were separated by silicic acid chromatography into neutral lipids, a fraction of mixed glycolipids that was eluted with acetone-methanol 9:1, and phospholipids. After mild alkali-catalyzed methanolysis to remove contaminants from the crude fraction of glycolipids, individual glycosyl ceramides were isolated by preparative thin-layer chromatography. The oligosaccharide portions of these lipids were characterized by cleavage with methanolic hydrogen chloride and gas chromatography of the O-trimethylsilyl methyl glycosides. It was possible to study the composition of the carbohydrate and sphingolipid base fractions in the same gas chromatographic analysis. With mannitol as an internal standard for gas chromatographic estimation of glucose, concentrations of each of the glycosyl ceramides were determined with a precision of about 10%. Recoveries of the lipids from plasma varied with the complexity of the oligosaccharide moiety and ranged from 94% with glucosyl ceramide to 71% with globoside. Concentrations of the four glycosyl ceramides in plasma and in erythrocytes were determined for samples from young, healthy males. Amounts of glycolipid as low as 0.1 micromole can be determined conveniently by this procedure.

Adult↗
PubMedDate not supplied

The combination of normal phase with reversed phase high performance liquid chromatography for the analysis of asparagine-linked neutral oligosaccharides labelled with p-aminobenzoic ethyl ester.

We have developed a novel approach for the analysis of asparagine-linked neutral oligosaccharides derived from glycoproteins. The oligosaccharides are labelled with p-aminobenzoic ethyl ester and the derivatives are separated on two high performance liquid chromatographic columns, one containing amide-silica and the other containing octadecyl-silica. The elution positions of 39 different ABEE-oligosaccharides on the two columns were plotted on a two-dimensional map. Unique non-overlapping positions of these oligosaccharides demonstrate that this technology would be useful for the identification of Asn-linked oligosaccharides at high sensitivity.

Asparagine↗
PubMedDate not supplied

Pleocytosis and elevation of prostaglandins F2a and E2 in cerebrospinal fluid following intracisternal injection of thrombin.

A marked pleocytosis and increase in the levels of prostaglandin F2a (PGF2a) and prostaglandin E2 (PGE2) were noted in cerebrospinal fluid of dogs within two hours following the intracisternal injection of thrombin. Quantitation of the prostaglandins (PG's) was done by gas chromatography-mass spectroscopy using deuterated PGF2a and PGE2 as internal standards. Whereas the levels of these prostaglandins were below the sensitivity of the method in control animals, a marked increase was noted following thrombin. PGF2a levels were 15-21 ng/ml and the PGE2 levels were 55-72 ng/ml. This concentration of the PG's is adequate to cause spasm of the cerebral vessels and could explain the spasm which occurs following the intracisternal injection of thrombin. These two effects, a pleocytosis and elevation of PG levels, may be specific to thrombin.

Animals↗
PubMedDate not supplied

Levels and disappearance of prostaglandin F2alpha in cerebral spinal fluid: a clinical and experimental study.

The concentration of prostaglandin F2alpha (PGF2alpha) was measured in cerebrospinal fluid (CSF) obtained by lumbar puncture in patients with subarachnoid hemorrhage and compared to control values. The level of this prostaglandin was elevated at some time in most patients during the course of their illness. However, this could not be correlated with the severity of neurological deficits observed. The possibility that the concentration of PGF2alpha in lumbar fluid may not reflect that present intracranially was tested experimentally in anesthetized dogs. In these experiments only a small fraction of the radioactive PGF2alpha injected into the cisterna magna appeared in lumbar CSF. Prostaglandin F2alpha rapidly disappeared from the cisterna magna, half time 8 minutes, and radioactivity was present in blood from the jugular vein indicating that normally this prostaglandin rapidly egresses from the CSF into blood. These findings suggest that PGF2alpha can be rapidly transported away from the brain. This could explain the low concentrations of PGF2alpha in CSF of normal individuals and in some patients who have severe cerebral vasospasm. Conversely, the elevation of PGF2alpha in lumbar CSF noted in some patients might be due, in part, to an impairment of transport caused by the size and location of the hemorrhage.

Animals↗