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Biomedical subjects

F Sebastiani

Publications and source records attributed to F Sebastiani.

17 recordsLinked to original sources

Chloroplast DNA phylogeography of European ashes, Fraxinus sp. (Oleaceae): roles of hybridization and life history traits.

We investigated range-wide phylogeographic variation in three European ash species (Fraxinus sp., Oleaceae). Chloroplast DNA (cpDNA) microsatellites were typed in the thermophilous Fraxinus angustifolia and Fraxinus ornus and the observed haplotypes and the geographic distribution of diversity were compared to cpDNA data previously obtained in the more cold-tolerant Fraxinus excelsior. We found wide-ranging haplotype sharing between the phylogenetically close F. angustifolia and F. excelsior, suggesting hybridization (i) in common glacial refuges in the Iberian Peninsula, northern Italy, the eastern and/or Dinaric Alps and the Balkan Peninsula, and/or (ii) during postglacial recolonization. The data allowed us to propose additional glacial refuges for F. angustifolia in southern Italy and in Turkey, and populations from the latter region were particularly polymorphic. There was evidence for refuge areas in Italy, the Balkan Peninsula and Turkey for F. ornus, which did not share any single chloroplast haplotype with the other species. In both F. angustifolia and F. ornus, cpDNA diversity (h(S) = 0.027 and h(S) = 0.009, respectively) was lower and fixation levels (G(ST) = 0.964 and G(ST) = 0.983, respectively) higher than in sympatric F. excelsior (h(S) = 0.096, G(ST) = 0.870). These diversity patterns could be due to temperature tolerance or the demographic history.

DNA, Chloroplast↗

Molecular differentiation of the Old World Culicoides imicola species complex (Diptera, Ceratopogonidae), inferred using random amplified polymorphic DNA markers.

Samples of seven of the 10 morphological species of midges of the Culicoides imicola complex were considered. The importance of this species complex is connected to its vectorial capacity for African horse sickness virus (AHSV) and bluetongue virus (BTV). Consequently, the risk of transmission may vary dramatically, depending upon the particular cryptic species present in a given area. The species complex is confined to the Old World and our samples were collected in Southern Africa, Madagascar and the Ivory Coast. Genomic DNA of 350 randomly sampled individual midges from 19 populations was amplified using four 20-mer primers by the random amplified polymorphic DNA (RAPD) technique. One hundred and ninety-six interpretable polymorphic bands were obtained. Species-specific RAPD profiles were defined and for five species diagnostic RAPD fragments were identified. A high degree of polymorphism was detected in the species complex, most of which was observed within populations (from 64 to 76%). Principal coordinate analysis (PCO) and cluster analysis provided an estimate of the degree of variation between and within populations and species. There was substantial concordance between the taxonomies derived from morphological and molecular data. The amount and the different distributions of genetic (RAPD) variation among the taxa can be associated to their life histories, i.e. the abundance and distribution of the larval breeding sites and their seasonality.

Africa↗

Reassessment of the specificity of lens opacities in myotonic dystrophy.

Cataract has been considered for a long time one of the major indicators of the presence of the mutated myotonic dystrophy (DM) gene in asymptomatic relatives of DM patients. However, some recent studies show that not all cases of cataract typical of DM are associated with the disease even in members of DM families. In order to determine the frequency of lens opacities characteristic of DM in the general population and to evaluate the specificity of lens anomalies for detection of the DM premutation, we screened a sample of 1,400 random individuals for the presence of 'myotonic cataract'. Ten individuals were found with the typical lens opacities and no neuromuscular signs of DM; molecular analysis of the DM mutation showed that they all carried two normal alleles. Our data allow to conclude that bilateral cortical iridescent and posterior cortical lens opacities cannot be considered a marker of the presence of the DM premutation in the general population.

Adult↗

A syndrome of progressive sensorineural deafness and cataract inherited as an autosomal dominant trait.

In 1982, Nadol & Burgess reported a new syndrome of cataract and progressive sensorineural hearing loss, inherited in an autosomal dominant fashion. Extensive histopathologic studies of the inner ear of the proband revealed severe cochleosaccular degeneration. No other sporadic or familial cases of such a genetic syndrome have subsequently been described. We report here a second family in which the syndrome of cataract and progressive sensorineural deafness is observed in eight members, and is inherited according to an autosomal dominant pattern.

Cataract↗

[Not Available].

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France↗

Pattern of lecithin-cholesterol-acyl-transferase (L-CAT) activity in the course of liver cirrhosis.

Considering liver cirrhosis a limit model, and therefore a condition suitable for the analysis of changes of lipid metabolism in liver disorders generally, the authors examined the L-CAT pattern, total and free cholesterol, HDL-cholesterol and APO-A in sixty-five subjects; fifty-three were suffering from liver cirrhosis, and were subdivided into those who were diabetic in addition, and those who were not, as well as according to the severity and duration of the liver disease; the remaining twelve were healthy controls. Analysis of the findings showed L-CAT to diminish significantly as the metabolic changes due to liver injury worsen. Contrary to the other parameters studied, L-CAT was the only one for which significant changes were found on analysis of variance comparing non-diabetic cirrhotics of varying severity. Further comparison suggested the idea that the reduction of L-CAT activity was correlated to the rate of progression of the disease rather than to the temporary condition of compensation or decompensation, so much so as to suggest itself as a valid parameter for the prognosis of liver cirrhosis.

Adult↗

[Clinical aspects and diagnostic criteria in non-obstructive symmetric hypertrophic myocardiopathy].

We describe the clinical data, the standard and Holter electrocardiographic observations, the carotid pulse tracings, the M-mode and B-mode echocardiographic findings and the left ventriculographic aspects of 21 patients with non-obstructive symmetric hypertrophic cardiomyopathy (NOSHCM). NOSHCM was diagnosed when there was echocardiographic and/or left ventriculographic evidence of septal and posterior wall hypertrophy without signs of left ventricular outflow destruction (LVOTO). Compared to the asymmetric hypertrophic obstructive cardiomyopathy (AHOCM), NOSHCM reveals reduced excursion of the posterior wall of the left ventricle, whereas patients with AHOCM have more frequently systolic murmurs and carotid pulse changes suggestive of LVOTO. Proper classification and treatment of NOSHCM are discussed.

Adult↗

[Reliability of M-mode and B-mode echocardiography in detection of left intra-atrial masses (author's transl)].

Although the role of echocardiography in the detection of left atrial masses is well established, reliability of the method is yet unknown. In 312 patients who underwent cardiac surgery, echocardiographic and anatomic findings were confronted. Pre-operative diagnosis was confirmed in the 8 cases with prolapsing tumors: in the remaining patients we had 5 false positive and 9 false negative diagnosis. So in our experience, sensibility has 73.5 and specificity 98.20.

Echocardiography↗

Genetic aspects of the worldwide colonization process of Ceratitis capitata.

Multilocus enzyme electrophoresis data from 26 polymorphic loci (124 alleles) were used to analyze the genetic aspects of the worldwide colonization of Ceratitis capitata (medfly). Eighty-two samples of 17 populations were collected from six regions throughout the species range: Africa, extra-Mediterranean islands (Madeira and Gran Canaria), Mediterranean region, Latin America (Guatemala), Pacific (Hawaii), and Australia. The variability parameters (H, P, A) reveal that the geographical dispersal of medfly from its ancestral source area (East Africa) is associated with a great reduction in variability. The pattern of decreasing variability occurs at two regional levels: in the African-Mediterranean region where the differentiation is gradual, and in the Latin American-Pacific region where some ancestral variability is still present as a consequence of recent colonization. The UPGMA phylogenetic tree, derived from Nei's genetic distances, shows the presence of intraspecific differentiative processes affecting mainly the two island populations, Réunion and Hawaii. The population genetic changes observed in the species range are consistent with both the chronology and the historical circuitous course of the medfly colonization process.

Animals↗