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Biomedical subjects

S Hazout

Publications and source records attributed to S Hazout.

46 records · Page 3Linked to original sources
PubMed1988

Restriction map construction using a 'complete sentences compatibility' algorithm.

We have developed a new algorithm 'Complete sentences compatibility' (CSC) which uses single and double digestion fragments to rapidly determine restriction maps of circular DNA. From possible combinations of fragments of each simple digestion, which we call 'sentences of decomposition', we construct a restriction map which combines the sentences while taking into account compatibility rules. The algorithm can also deal with experimental errors of fragment weight and can suggest solutions that account for non-readable bands (fragments of zero length or multiple bands) on the gel. Because experiments using pairs of restrictive enzymes often result in multiple solutions, a complementary algorithm tries to reduce the number of proposed solutions by establishing consensus maps. The restriction map construction algorithm was tested on real cases, some containing more than fifteen fragments. Execution times range from 1-10 s on an IBM PC compatible microcomputer.

Algorithms↗
PubMed1987

The algorithm of the cockshafer walk: a movement automaton applied to the construction of the integrated optical density profile of prometaphase chromosomes.

We present an algorithm designed to obtain the optical density profile of prometaphase chromosomes. Our movement automation (the cockshafer) is able to move along the median axis of the chromosome. The criterion used to maintain the correct movement direction lies on the distances from the automaton position to the side boundaries (lengths of the cockshafer antennae). The automaton movements are regulated by rules defined in a decision repertory. This new method does not use a transformation of the image and does not require any prior knowledge of the shape of the chromosome to be sampled.

Algorithms↗
PubMed1987

Evolution of immunoglobulin allotypes and phylogeny of apes.

Serum samples from 72 Pan troglodytes, 5 Pan paniscus, 22 Gorilla gorilla, 23 Pongo pygmaeus abelii, 5 Pongo pygmaeus pygmaeus, 2 hybrids P.p. abelii X P.p. pygmaeus and 13 Hylobates lar were tested for Gm(1, 2, 3, 5, 6, 10, 11, 13, 14, 15, 16, 17, 21, 24, 28), Km(1) and Bm(1, 2, 3, 4, 5, 6, 7, 8) immunoglobulin allotypes by the classical hemagglutination inhibition method. The distribution of the various alleles and phenotypes makes it possible to distinguish each species or subspecies. Common chimpanzees have the richest polymorphism. Pygmy chimpanzees share common phenotypes with gorillas. Bornean and Sumatran orangutans have their own patterns of polymorphism, as do gibbons. Our principal component plot and dendrogram are compatible with the traditional classification of Hominoidea [e.g. Simpson, Bull. Am. Mus. nat. Hist. 85: 1-350, 1945] in 3 families: Hominidae, Pongidae and Hylobatidae.

Animals↗
PubMed1986

[Towards a genealogy of chromosome Y].

Taq I restriction polymorphisms of the 49 f genomic probe are used to establish a possible filiation of the Y chromosome in human populations. Relationships between alleles at the five polymorphic loci revealed by the probe allow the description of 17 haplotypes. Simulations are used to construct a plausible genealogy of these various haplotypes, on the basis of a limited set of basic hypotheses concerning polymorphic alleles evolution.

Biological Evolution↗
PubMed1985

Population distribution of the human vitamin D binding protein: anthropological considerations.

The polymorphism of the serum vitamin D binding protein (DBP) in humans is based on the existence of three common alleles, Gc1F, Gc1S, and Gc2, and 84 rare alleles. The geographical distribution of Gc1F, Gc1S, and Gc2 alleles shows north to south clines, together with a balanced equilibrium between the Gc1F or Gc1S allele frequency and the Gc2 frequency. The distribution of the FST values shows high variability within a geographical area. For European and North Asiatic groups, the FST values are the lowest observed, and the reason may be a long process of homogenization. Aboriginal populations from Australia and New Guinea and groups from both North Africa and South America show the greatest heterogeneity of their allele frequencies. Systematic factors such as genetic drift and selection may account for this distribution. In contrast with the three main DBP alleles, the distribution of the rare alleles corresponds to patterns of human migrations that occurred during prehistoric and historic periods. Thus, the rare mutants are of particular relevance to anthropological and genetical investigations.

Alleles↗
PubMed1979

Computer-aided analysis of chromosomal aberrations occurring in an abnormal human karyotype.

A semi-automatic method for recognition of chromosomal changes is presented: from a coded description of an abnormal chromosome (formulated with the aid of an R-banding technique), a computer program makes simulations to reconstitute this chromosomal image from a group of normal chromosomes. Nine types of aberrations (see text) can thus be recognized and the aggregate structure of a group of abnormal chromosomes occurring in a human karyotype can also be rediscovered.

Chromosome Aberrations↗
PubMed1978

The thymol turbidity test and determination of serum cholesterol : two tests to abandon in the routine evaluation of liver function.

The thymol turbidity test (Macglan's test) and the determination of serum cholesterol are still performed routinely as liver function tests in many laboratories. In this report, we have employed quantitative methods in order to evaluate the real usefulness of these two parameters. In a first step, the value of the thymol test and of cholesterol determination for the discrimination of the 13 most frequent hepato-biliary diseases was studied by analysis of variance, and compared to that of the following tests : serum bilirubin, serum glutamic pyruvic transaminase, serum alkaline phosphatase serum protein electrophoresis and prothrombin time. It was found that of all these parameters, the thymol test and cholesterol measurement had the lowest discriminatory powers. In a second step, the consequences of the suppression of the two tests were examined by linear discrimination analysis, which was done for all the possible pairs of diseases. It appeared that in each case, the loss of information due to the elimination of the thymol test or of cholesterol determination was nil or negligible. We conclude therefore that the thymol turbidity test and determination of serum cholesterol should be abandoned as routine tests of liver function.

Cholesterol↗
PubMed1977

Planning the suicide experiments.

Suicide experiments involve a great degree of uncertainty in the counting of cell colonies. This work studies from a statistical point of view the precision of the estimation as a function of the number of experimental units which are used. Assuming that the colony numbers in recipients follow a Poisson distribution, we give the necessary number of recipients (a) to determine with a given accuracy the percentage of DNA synthesizing cells (S cells), (b) to test whether or not a cell population is quiescent, and (c) to compare the percentages of S cells in two cell populations.

Animals↗
PubMedDate not supplied

Surname distribution in France: a distance analysis by a distorted geographical map.

The distribution of surnames in 90 distinct regions in France during two successive periods, 1889-1915 and 1916-1940, is analysed from the civil birth registers of the 36,500 administrative units in France. A new approach, called 'Mobile Site Method' (MSM), is developed to allow representation of a surname distance matrix by a distorted geographical map. A surname distance matrix between the various regions in France is first calculated, then a distorted geographical map called the 'surname similarity map' is built up from the surname distances between regions. To interpret this map we draw (a) successive map contours obtained during the step-by-step distortion process, revealing zones of high surname dissimilarity, and (b) maps in grey levels representing the displacement magnitude, and allowing the segmentation of the geographical and surname maps into 'homogeneous surname zones'. By integrating geography and surname information in the same analysis, and by comparing results obtained for the two successive periods, the MSM approach produces convenient maps showing: (a) 'regionalism' of some peripheral populations such as Pays Basque, Alsace, Corsica and Brittany; (b) the presence of preferential axes of communications (Rhodanian corridor, Garonne valley); (c) barriers such as the Central Massif, Vosges; (d) the weak modifications of the distorted maps associated with the two periods studied suggest an extension (but limited) of the tendency of surname uniformity in France. These results are interpreted, in the nineteenth- and twentieth century context, as the consequences of a slow process of local migrations occurring over a long period of time.

France↗