The determination of frequency value (percentile limits) and the classification of the different variation factors allow us to define more and more homogeneous subpopulations as we use these factors for sorting. Using as our study population those persons coming to the Centre for Preventive Medicine, we were able to: (a) Describe and measure the significance and importance of physiological variations or of variations attributed to age—the latter largely related only to excessive weight, which it seems to us is often the case. (b) Establish a classification for variation factors; the recapitulatory table should be useful to clinical chemists in helping physicians interpret a laboratory test result that falls within the zone of incertitude. (c) Suggest a preliminary group of reference values for healthy subjects, to be used in interpreting a laboratory test in this way.

No abstract

Fatty acid and cholesterol synthesis in isolated rat hepatocytes were strongly inhibited by 5-(tetradecyloxy)-2-furoic acid. With either 3H2O or [2(-14)C] acetate as the labeled precursor, the concentrations of inhibitor causing 50% decrease in fatty acid and cholesterol synthesis were, respectively, less than 0.005 mM and 0.020 mM. At 0.1 mM inhibitor, citrate concentration in cells from fed rats was increased by 75%; lactate and pyruvate concentrations were decreased by 30%; ethanol oxidation was decreased by 20%; with cells from starved rats, the mitochondrial [NAD+]/[NADH] was decreased. Other parameters were unaffected. Both its potency and its specificity indicate that 5-(tetradecyloxy)-2-furoic acid will be useful in studies on the regulation of lipid biosynthesis.

Resume: ^adaptation du dosage des triglycorides par voie entierement enzymatique a ete rSalisee sur GSA II Greiner. La methode ne nocessite que 20 de prise d'essai de matoriel biologique. Le temps de la reaction est court: 8 min a 37 °C. Le coefficient de variation de la mothode ne depasse pas 6% sur une periode de un mois. La linoarite des mesures est vörifiie jusqu'ä un taux de 4 mmol/1. II a 6t& montro que le taux de glycerol libre doit etre mesure systematiquement et doduit du glycerol total pour assurer Pexactitude des rosultats. La stabilite des triglycerides plasmatiques a 6t6 verifiee en fonction de la duree et de la temperature de conservation (+ 4 °C et -196 °C). Le glycerol libre augmente en fonction du temps, alors que le taux de triglycerides demeure constant. Nous n'avons constati aucune interference analytique en prisence d'himoglobine ou de medicaments, en particulier hypolipemiants et hypoglycemiants. Adaptation of an entirely enzymatic, triglyceride assay to the GSA II Greiner. Application to the study of the stability of triglycerides, and factors causing interference in the analysisSummary: The assay of triglycerides by an entirely enzymatic pathway was adapted for use on the GSA II Greiner. The method requires only 20 of biological material. The reaction time is short: 8 min at 37 °C. The coefficient of variation does not exceed 6% over a period of one month. Linearity of the measurements was verified up to a level of 4 mmol/1. It was shown that the free glycerol level should be systematically measured and deducted from that of the total glycerol to assure accurate results. The stability of the plasma triglycerides was investigated as a function of the length and temperature of storage (+ 4 °C and -196 °C). The free glycerol increases as a function of time, whereas the level of triglycerides stays constant. Haemoglobin and various medicaments, in particular, hypolipemiants and hypoglycemiants, did not interfere.

We studied factors influencing concentrations of triglycerides in the blood of a presumably healthy population of about 9000 persons. Using multi-dimensional analysis, we show, in addition to various related to sex and age, the relation between triglycerides and uric acid, overweight, arterial blood pressure, use of oral contraceptives (in women), consumption of alcohol and tobacco, and lack of physical exercise. These factors were classified as a function of their discriminative power by the statistical method of segmentation. We thus chose the following factors as criteria for exclusion from a reference population for the values of triglycerides in blood: in men 20 to 39 years old, overweight more than 90%; in men 40 to 59 years old, overweight of more than 115%, consumption of more than half a liter of wine per day or of more than 11 cigarettes, use of medicines, and a blood uric acid exceeding 420 mumol/L; in women 20 to 39 years old, contraceptives and overweight; in women 40 to 59 years old, overweight or more than 130% and the intake of medicines. At the 97.5th percentile of the reference population as compared with a non-selected population, the values were 80% less for men 20 to 39 years old, 95% less for men 40 to 59 years old, and only 26 to 30% less for women 20 to 59 years old.