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Biomedical subjects

G Laval

Publications and source records attributed to G Laval.

31 records · Page 2Linked to original sources
PubMed1988

[Environmental factors and acute leukemia in children. Apropos of a case-control study carried out in the Rhône-Alpes region].

To test the large number of hypotheses proposed as causes for childhood leukemia, a case control study was carried out on every child diagnosed for acute leukemia between 1.1.1977 and 12.31.1982, under the age of 15 and living in the region of Lyon (Rhône-Alpes and Saône-et-Loire). Some factors could not be confirmed, possibly in relation with the relatively small sample size (208 cases). Others were confirmed, especially the excess of incidence among 2 to 4 year old children and those belonging to higher socioeconomic groups. Two new factors were identified: the age of the father (over 40 years at child birth) and the profession of the father (manipulation of meat in the few years prior the diagnosis of leukemia in the child).

Acute Disease↗
PubMed1981

[Echocardiography of an operated case of a myxoma of the tricuspid valve].

The case of a 6 year old child with a tricuspid valve myxoma is presented. Early diagnosis by echocardiography, confirmed by angiography, resulted in surgical cure before any symptoms appeared. This is the only reported echocardiographic study of a myxoma inserted on the tricuspid valve found in a review of the literature of 6 cases of right ventricular myxoma. The tricuspid valves were found to be thickened and prolapsed into the right atrium. The amplitude of excursion of the anterior leaflet was greatly increased, its mass projecting into the right ventricular outflow tract in diastole and remaining there until the end of right ventricular ejection. The echocardiographic signs localising the precise origin of the tumor in the tricuspid valve are developed. The differential diagnosis with right atrial myxoma prolapsing into the ventricular cavity, benign and malignant right ventricular tumours and tricuspid valve vegetations is discussed. The precision of the diagnostic information obtained by echocardiography suggests that angiography may not be essential any longer, especially when the risk of embolisation and acute obstruction are taken into consideration.

Child↗
PubMedDate not supplied

Genetic diversity of eleven European pig breeds.

A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall F(ST)= 0.27), and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

Journal Article↗