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J L Third

Publications and source records attributed to J L Third.

36 records · Page 2Linked to original sources
PubMed1980

Increased plasma fibrinogen and platelet-aggregates in type II hyperlipoproteinaemia.

Plasma fibrinogen and platelet-aggregates (method of Wu and Hoak) were measured in 21 patients with familial Type II hyperlipoproteinemia and 21 matched control subjects. Patients with hyperlipoproteinaemia had increased levels of fibrinogen and platelet-aggregates (p less than 0.01). Young patients with hyperlipoproteinaemia had prematurely high fibrinogen levels, and the normal rise in fibrinogen during adult life was abolished. There were no statistically significant correlations within the patient group between fibrinogen, platelet-aggregates, and plasma lipids. High fibrinogen and platelet-aggregate levels may play a part in the development of the premature arterial disease associated with Type II hyperlipoproteinaemia, or may be markers of arterial injury.

Adolescent↗
PubMed1979

The effects of cholestyramine on high density lipoprotein metabolism.

This study on 4 type II hyperlipoproteinaemic subjects examines the effects of pharmacologic doses (8 g twice daily) of the bile acid sequestrant cholestyramine on the plasma distribution and chemical composition of the high density lipoprotein subfractions, HDL2 and HDL3, and describes the influence of the drug on the metabolism of the major HDL aporoteins, apolipoprotein A-I and A-II. Cholestyramine lowered plasma low density lipoprotein cholesterol (32%; P less than 0.05) without affecting the level of that lipid in very low density or high density lipoproteins. However, the plasma HDL2/HDL3 ratio and apolipoprotein A-I concentration rose significantly on treatment, while apolipoprotein A-II remained unchanged. The rise in apolipoprotein A-I derived from an increase in its synthetic rate and produced a relative enrichment of the protein with respect to apolipoprotein A-II in both HDL subfractions. These results demonstrate the cholestyramine treatment affects HDL metabolism in a way which, according to current concepts, may prove beneficial to the recipient.

Apolipoproteins↗
PubMed1978

Effect of clofibrate on the composition of very low and low density lipoprotein subfractions in type III hyperlipoproteinaemia.

The effect of clofibrate on the lipid and protein composition of very low and low density lipoprotein subfractions (VLDL of SF greater than 100, 60-100 and 20-60; LDL of Sf 10.4-20, 5.7-12 and 3.5-6.5), was investigated in 6 patients with type III hyperlipoproteinaemia (HLP). After four weeks of therapy significant reductions occurred in the concentration of cholesterol in each VLDL fraction, and of triglycerides in Sf greater than 100 and Sf 60-100 VLDL. No changes were found in the concentrations of apolipoprotein B or of the total tetramethylurea (TMU) soluble proteins, but in four patients in whom polyacrylamide disc gel electrophoresis of the TMU soluble proteins was carried out, it was found that arginine-rich peptide (ARP) had largely disappeared on therapy. These findings would be in keeping with increased catabolism of VLDL in response to clofibrate. No significant changes were observed in LDL lipid or protein concentrations.

Apolipoproteins↗
PubMed1978

Regulation of cholesterol synthesis in the hyperlipoproteinaemias. Polymorphonuclear leucocyte abnormality specific to familial type II hypercholesterolaemia.

A simple procedure has been devised to give virtually pure preparations of polymorphonuclear leucocytes. This has permitted study of the regulation of cholesterol biosynthesis at cell level. Freshly isolated cells from donors with various forms of hyperlipoproteinaemia have been shown to have very low levels of cholesterol synthesis, presumably due to high circulating levels of apoprotein-B in donor plasma [1]. The activity of the rate-limiting enzyme for cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A reductase, rapidly increases as the cells are incubated in lipoprotein-deficient medium, until, by 12 h, cells from patients heterozygous for familial type IIa hypercholesterolaemia are clearly distinguished from other hyperlipoproteinaemias. The possible significance of this finding is discussed in relation to the causation and treatment of atherosclerotic disease.

Cells, Cultured↗
PubMed1977

The composition of low (LDL) and very low (VLDL) density lipoprotein subfractions in type III hyperlipoproteinaemia: comparison with normal subjects.

The lipid and protein composition of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) subfractions (Sf greater than 100, 60--100 and 20--60 VLDL and Sf 10.4--20, 5.7--12 and 3.5--6.5 LDL) in six subjects with type III hyperlipoproteinaemia (HLP) was compared to that of 12 normal subjects. In type III HLP all VLDL subfractions contained increased concentrations of cholesterol and triglycerides and were relatively enriched in cholesterol. VLDL of Sf 20--60 also contained and increased concentration of B-protein. The tetramethylurea (TMU) soluble apolipoproteins of the VLDL subfractions were separated by polyacrylamide disc gel electrophoresis. In the subjects with type III HLP the proportion of arginine rich protein (ARP) was increased in all subfractions. The concentrations of cholesterol and triglycerides were increased in the LDL subfraction of Sf 10.4--20 and cholesterol was decreased in LDL of Sf 5.7--12, but the ratios of cholesterol to triglycerides were not significantly different from those in the LDL subfractions of the normal subjects and the protein composition was also similar. These results provide further evidence that in type III HLP abnormalities are not confined to the stage of conversion of VLDL to LDL, but occur throughout the VLDL spectrum.

Adult↗
PubMed1977

Electrophoretic mobility in agarose of very low density lipoprotein subfractions in type III hyperlipoproteinaemia.

The electrophoretic mobilities in agarose gel of the very low density lipoprotein (VLDL) subfractions of Sf greater than 100, 60-100 and 20-60 from six subjects with type III hyperlipoproteinaemia (HLP) have been compared with those from eight normal volunteers. In type III HLP beta or near-beta (slower VLDL) electrophoretic mobility was not necessarily confined to the VLDL fraction of Sf 20-60 in which it may normally be detected.

Adult↗
PubMed1976

Low density lipoprotein metabolism in a family of familial hypercholesterolemic patients.

A low-density lipoprotein turnover study was performed on six heteroxygous familial hypercholesterolemic subjects and five control subjects. The diagnosis of the condition was clear-cut on biochemical, clinical, and genetic grounds. Kinetic analysis of the plasma decay curves gave the following mean values: (1) The plasma concentration of low density lipoprotein apoprotein (apoLDL) in the affected subjects was 247 mg/dl, a 2.5-fold increase over control values (98 mg/dl). (2) The calculated fractional catabolic rate of the intravascular apoLDL pool in the dyslipo-proteniemics was reduced with respect to control data (16.4%/day versus 31.2%/day), and the half-life of the apolipoprotein was correspondingly increased (6.07 days versus 3.63 days). (3) The absolute catabolic rate of the apoLDL was 15.6 mg/kg/day in contrast to the lower value of 11.6 mg/kg/day in the control group. (4) A strong negative correlation was observed between the plasma apoLDL concentration and the fractional catabolic rate (r = 0.96). We conclude from our data that increased apoLDL synthesis coupled with a defective or saturated catabolic mechanism is implicated in the pathogenesis of familial hypercholesterolemia.

Adult↗
PubMed1975

Relation between extent of coronary artery disease and severity of hyperlipoproteinaemia.

Lipoprotein analyses were performed in 133 male patients and were correlated with the coronary arteriographic findings. The prevalence of hyperlipoproteinaemia was significantly higher in those patients with coronary artery disease (P less than 0-02). In addition, the more extensive the degree of coronary artery pathology the higher were the plasma concentrations of total cholesterol, triglyceride, and low density lipoprotein (LDL) cholesterol. Hyperlipoproteinaemia was more prevalent in the younger patients with coronary artery disease (P less than 0-02).

Age Factors↗
PubMed1975

Diagnosis of type III hyperlipoproteinemia by chromatography of plasma lipoproteins on columns containing agarose.

Agarose column chromatography has been used to separate plasma lipoproteins into very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Applied to the diagnosis of primary type III hyperlipoproteinemia, the procedure is capable of demonstrating three characteristic and specific changes from normality in the elution pattern of lipoproteins from patients with this condition. In the type III profile there is (a) incomplete separation of VLDL from putative LDL material, (b) early elution of the type III LDL with respect to a normal LDL marker, and (c) relative deficiency of type III LDL with elution characteristics of normal LDL. We advocate the use of this method in the diagnosis of type III hyperlipoproteinemia.

Adult↗