[Preventive treatment of jaundice in premature newborn infants with clofibrate. Double-blind controlled therapeutic trial]. / Traitement préventif de l'ictère du nouveau-né prématuré par le clofibrate. Essai thérapeutique contrôlé en double aveugle.

A double blind therapeutic trial of ethyl clofibrate as a preventive treatment of hyperbilirubinemia in preterm neonates was performed in neonates of gestational ages ranging between 31 and 36 weeks. Forty-six children were given the treatment and 43 a placebo. A single 100 mg/kg dose of ethyl clofibrate was administered orally, between the 24th and the 48th hour of life. Significant results in the treated neonates are as follows: a lesser intensity of jaundice from the 48th hour of treatment; a lesser need for repeated bilirubinemia assay for the control of evolution and a lesser use of phototherapy if the serum concentration of clofibric acid is above or equal to the 140 micrograms therapeutic level before the 24th hour of treatment. The analysis of results also shows that the therapeutic clofibric acid serum level is reduced in 66% of neonates of relatively high gestational ages (34-36 weeks) and in 33% only of neonates of lower gestational ages (31-33 weeks). This study, added to the previous therapeutic trial performed in at term neonates, shows the efficacy of clofibrate in the preventive treatment of hyperbilirubinemia in preterm neonates. Further studies will allow to define the exact dosage according to gestational age.

[Course of the concentration of serum free amino acids as a function of time and the method of preservation]. / Evolution de la concentration des acides aminés libres du sérum en fonction du temps et du mode de conservation.

In order to determine the optimal conditions for storage in the case of deferred serum amino acid assay, the authors studied the effect of storing the sample for four hours at two different temperatures: melting ice and ambient temperature, as well as the effect of storing the amino acids for three months according to four methods of storage; freezing at -20 degrees C and -80 degrees C of deproteinised and non-deproteinised serum. When the analysis was performed within four hours of collection of the specimen, the best conditions are obtained when the sample is kept at the temperature of melting ice. The optimal conservation consists of immediately deproteinising the sample and storing it frozen for 14 days.

Lactate dehydrogenase isoenzyme activity in malignant haematological diseases.

The isoenzymes 1 and 2 (LDH1 and LDH2) of lactic dehydrogenase (LDH) were studied in the serum of 32 patients with malignant haematological diseases. In non-Hodgkin lymphoma (NHL) a diminution in LDH1 and an increase in LDH2 was a sign of evolution towards a more aggressive phase of the disease, or the absence of clinical remission, even when no significant variation of total LDH can be observed in the serum. In acute lymphoblastic leukaemia (ALL), the isoenzymatic variations are not an early indication of relapse. No significant variations in serum LDH or of these isoenzymes was observed in chronic lymphocytic leukaemia (CLL) or Hodgkin's disease (HD). Only in NHL did the variations of LDH1 and LDH2 appear to be a biochemical marker of the tumour process and of cellular differentiation.

[Structural relations in the comparison of methods in clinical chemistry. Application to the study of bias between a centrifugal analysis (Cobas) and the Kodak-Ektachem method]. / La relation structurale dans la comparaison de méthodes en chimie clinique. Application à l'étude du biais entre une analyse centrifuge (Cobas) et le procédé Kodak-Ektachem.

In this paper, the authors present the aims of a comparison of 2 biochemical methods in terms of their accuracy. They discuss the inadequacies of classical statistical techniques (paired series, linear correlation coefficient, regression). Instead of them, the authors suggest other approaches based on the structural relationship and, more particularly, York's method which, at the present time, seems to be the best one adapted to the most frequently encountered experimental conditions. They illustrate their view by a study of bias between centrifuge analysis (Cobas) and the Kodak-Ektachem process in plasma calcium assay.

[Plasma zinc levels in elderly hospitalized subjects. Correlation with other nutritional and immunological markers and survival]. / Le zinc plasmatique chez le sujet âgé institutionnalisé. Corrélations avec d'autres marqueurs nutritionnels, immunologiques et la survie.

Plasma zinc levels were measured in 95 elderly patients hospitalized in a long stay unit and in 100 healthy controls under 65 years of age. Plasma zinc concentrations were significantly lower in the elderly patients, as compared to the younger subjects (p 0.001). The correlations with serum prealbumin (p 0.05) and serum albumin (p 0.05) concentrations and the frequent association with protein-calorie malnutrition suggest that the low serum zinc levels mirror a low dietary zinc intake. Immunological tests in the elderly show moderate lymphopenia, high serum IgA and frequent depression of delayed cutaneous hypersensitivity to DNCB and PHA. We find a significant correlation between plasma zinc concentration and peripheral blood lymphocyte counts, but not the other immunological parameters. Linear discriminant analysis shows that the association of low plasma zinc values, low serum protein concentration and high serum IgG concentration implies poor prognosis.

New statistical approach in biochemical method-comparison studies by using Westlake's procedure, and its application to continuous-flow, centrifugal analysis, and multilayer film analysis techniques.

In this paper, we present an application of Westlake's method (Biometrics 32:741, 1976) in method-comparison studies in clinical chemistry. The techniques under study are continuous flow (CF), centrifugal analysis (CA), and multilayer film analysis (the Kodak Ektachem procedure KE). The experimental data are for plasma calcium and serum uric acid. It results from a particular regression procedure proposed by York (Can J Phys 44:1079, 1966) that the usual regression comparison technique (joint testing procedure) is irrelevant because it rejects the identity hypothesis for the three methods, whereas fixing a tolerable upper limit deviation, delta, between two methods would lead to the conclusion that, in 95% of cases, CF and KE results are equivalent for plasma calcium (delta less than or equal to 45 mumol/L) and CF is roughly equivalent to the other two methods for serum uric acid (delta less than or equal to 27 mumol/L).

[Measurement of plasma and urinary amino acids with gas chromatography in healthy subjects. Variations as a function of age and sex]. / Mesure des acides aminés plasmatiques et urinaires par chromatographie en phase gazeuse chez des sujets sains. Variations en fonction de l'âge et du sexe.

Using gas chromatography, we measured the concentrations of amino acids in a group of 80 selected subjects: we present the plasma values which we obtained, as well as those of other authors. Various comparisons were made, according to the age and/or sex of the subjects. We found that the plasma levels of valine, leucine, isoleucine and proline in patients of any age, the levels of hydroxyproline and phenylalanine in subjects over the age of 45 and the levels of ornithine in subjects under the age of 45, are higher in men, while the level of threonine is higher in women under the age of 45 than in men of the same age. These sex differences are significant. Valine, leucine, isoleucine, hydroxyproline, phenylalanine and ornithine are significantly higher in the plasma of elderly men, while plasma ornithine is higher and plasma threonine is lower in elderly women than in young women. We also determined the normal values of urinary amino acids and were unable to demonstrate any differences in terms of age or sex. We defined four groups of amino acids, according to their clearance values. However, these groups do not correspond to those defined by the existence of renal tubular transport systems common to certain amino acids.