High-density lipoprotein (HDL) cholesterol levels were decreased in patients with non-insulin dependent diabetes at diagnosis when matched with a control population for sex, age, obesity, alcohol consumption and cigarette smoking. There was no association between serum HDL-cholesterol concentration and the percentage of glycosylated haemoglobin A1 (HbA1). Serum HDL-cholesterol levels were lower in diabetics over the whole range of serum triglyceride levels, and particularly in hyper-triglyceridaemic diabetics. Serum apolipoprotein A-I levels were not decreased in diabetics with normal serum triglyceride levels, so that the ratio of HDL-cholesterol to apolipoprotein A-I was significantly decreased in diabetics (p Less Than 0.005). Decreased HDL-cholesterol levels in non-insulin dependent diabetes could be relevant to the subsequent development of atherosclerosis.

Adult↗

PubMed1980

An assessment of the Corning electrophoretic procedure for high density lipoprotein cholesterol estimation.

The electrophoretic procedure for high density lipoprotein cholesterol determination recently introduced by Corning Medical has been assessed. The results corrrelated well with those obtained by phosphotungstate/Mg precipitation and ultracentrifuge procedures, but the between-batch CV was 6% in the clinically important range below 1 mmol/l. The densitometer, which must be carefully aligned before use for this analysis, seemed sensitive to variations in the plates and patterns produced. The technique required that great care, especially with timing, and appeared expensive.

Chemical Precipitation↗

PubMed1980

Variability in the adsorption properties of microtitre plates used as solid supports in enzyme immunoassay.

We evaluated the variability in the amount of protein adsorbed onto the surface of individual wells of an assortment of microtitre plates by use of procedures involving enzyme-protein conjugates. Coefficients of variation in adsorbed protein ranged from 5.2 to 29.5%. Microtitre plates show a distinct "edge effect"; wells at the edges of a plate adsorb more protein than those in the interior, which markedly affects results from immunoassays involving such plates. In a sandwich enzyme immunoassay the results for an individual sample varied by +/- 18%; in a competitive assay, values read from different calibration curves in the same plate varied by +/- 11%. Scanning electron microscopy and birefringence studies demonstrated no marked physical differences between individual wells on a plate. The variability in the amount of protein adsorbed onto the surface of individual wells on the same microtitre plate seriously affects the reliability and interpretation of results of immunoassays in which such plates are used as solid supports.

Alkaline Phosphatase↗

PubMed1980

Applicability of various quality-control sera to assay of high-density lipoprotein cholesterol.

Effective internal quality control and external quality assessment of high-density lipoprotein cholesterol assay is made difficult by analyte instability, and the suitability of quality-control sera for this purpose has not been studied. We have therefore investigated the properties of 25 different control sera from 15 suppliers by estimating within-batch precision for the two precipitation procedures used most widely (phosphotungstate/Mg2+ and heparin/Mn2+ with enzymic measurement of cholesterol. Some sera had properties similar to those of fresh human serum, but others demonstrated poor precision for one or both procedures or contained apparent high-density lipoprotein cholesterol in unphysiological concentrations. A study of six sera indicated that between-batch precision was consistent with the within-batch findings. We found that eight of the 25 batches of quality-control serum we investigated may be used for internal quality control and external quality assessment of high-density lipoprotein cholesterol assay.

Chemical Precipitation↗

PubMed1979

H.D.L. cholesterol analysis.

Explore the source record for details and available documents.

Adult↗

PubMed1979

Thermal characteristics of microtitre plates used in immunological assays.

Thermal studies of various types of microtitre plate have shown that wells at the edges of a plate have different thermal characteristics from those in the centre. This may contribute to the 'edge effect' observed when such plates are used as solid supports for protein immunobilisation in immunoassays.

Antigen-Antibody Reactions↗

PubMed1979

High-density lipoprotein cholesterol analysis.

Explore the source record for details and available documents.

Cholesterol↗

PubMed1979

Analytical luminescence: its potential in the clinical laboratory.

The various types of chemiluminescent and bioluminescent reactions are described. Applications of luminescence in the analysis of substancs of clinical interest are surveyed. The advantages, disadvantages, and prospects for luminescent assays are discussed.

Adenosine Triphosphate↗

PubMed1978

The differential effects of relocation on nursing home patients.

Explore the source record for details and available documents.

Adaptation, Psychological↗

PubMed1977

A method for enhancing the stability of thiol-containing enzymes immobilised on nylon.

The limited stability of immobilised enzymes is a major factor restricting their use in clinical chemistry. The immobilisation procedure described here affords a simple method of enhancing the stability of certain enzymes immobilised on nylon. Studies with alcohol dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase have indicated that a significant increase in stability can be obtained using this immobilisation procedure as compared with conventional procedures. As anticipated the immobilisation procedure was unsatisfactory for oxidases such as glucose oxidase.

Alcohol Oxidoreductases↗