Hemoglobin Roseau-Pointe a Pitre alpha 2 beta 2(90) (F6) Glu----Gly: a new hemoglobin variant with slight instability and low oxygen affinity.

A Dominican neonate carrying a new abnormal hemoglobin, hemoglobin Roseau Pointe-à-Pitre alpha 2 beta 2(90)(F6) Glu----Gly, was detected in Guadeloupe during application of a cord blood screening program. This variant behaved in isoelectrofocusing as an Hb D, and displayed instability and low whole blood oxygen affinity. In the affected family it was present, either isolated, or in association with a beta+ thalassemia trait.

[Antenatal diagnosis of sickle-cell anaemia by DNA analysis of amniotic fluid cells. A preliminary study in the French West-Indies (author's transl)]. / Diagnostic prénatal de la drépanocytose par analyse de l'ADN des cellules amniotiques. Etude préliminaire aux Antilles.

The genetic polymorphism previously reported to be associated with the sickle-cell (beta S) gene in black U.S.A. citizens was studied in the population of two French West-Indies islands in order to evaluate its potential application to the antenatal diagnosis of sickle-cell anaemia. The polymorphism consists of a change in the DNA sequences located near the 3' end of the beta globin gene. The change can be detected by means of the restriction endonuclease Hpa I. When cellular DNA is digested with this enzyme, the beta globin gene is contained in a DNA fragment measuring either 7.6 or 13.0 kilobases (kb). In 70% of SS homozygous subjects in Martinique and 57% in Guadeloupe the beta S gene was carried by a 13.0 kb DNA fragment, whereas the normal beta A gene was carried by a 7.6 kb DNA fragment. This polymorphism would make it possible to detect the foetal beta S gene in the DNA of amniotic fluid cells by linkage analysis.

Isoelectric focusing of human hemoglobins.

Isoelectric focusing on thin layer of acrylamide gel has been used for the characterization of 79 different variants of hemoglobin A. This method has replaced the cellulose acetate electrophoresis in clinical laboratories in Martinique, Guadeloupe and Creteil for the detection of abnormal hemoglobins in populations at risk. Up to now 15,000 samples from adults have been evaluated. In addition this method has been used for the screening of 7,000 cord blood samples and for the prenatal diagnosis of severe hemoglobinopathies.

[Ecology of intestinal schistosomiasis in Guadeloupe. Epidemiological analysis and data for a model study (author's transl)]. / Ecologie de la schistosomose intestinale en Guadeloupe. Analyse du système épidémiologique. Documents pour un essai de modélisation.

In Guadeloupe, during a general survey on intestinal schistosomiasis, the authors made a structural analysis of a limited focus of infection. The focus is formed by a river basin on the Carribean coast of Basse-Terre island. Sampling of the various elements of the parasitic cycle was done in spatial units defined by ecological and epidemiological criteria. The study of corresponding populations shows that: -- inside the twelve delimited sectors, only two include both hosts and parasites. They are zones with ditches and small temporary streams; -- the vector (Biomphalaria glabrata) density is always high in inhabited sectors; -- the rat, although present over the whole river basin, is only parasitized near inhabited places; -- fluorescent antibody level is an excellent indicator of the level of infection of human populations. Its variation can be detected in a time interval of less than one year; -- distance from contaminated water is one of the principal risk factors. A mathematical expression for this is given.