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F Ellouze

Publications and source records attributed to F Ellouze.

8 recordsLinked to original sources

Isolation and structure determination of natural analogues of the mycotoxin ochratoxin A produced by Aspergillus ochraceus.

Three new natural mycotoxins, analogues of ochratoxin A, in which the phenylalanine moiety is replaced by serine, hydroxyproline or lysine, were isolated from cultures of Aspergillus ochraceus by TLC followed by HPLC column chromatography. Their structures were determined after acidic hydrolysis by the characterisation of both their amino acid moieties and of ochratoxin alpha, the chlorinated dihydroisocoumarin moiety of ochratoxin A. These structures were confirmed by mass spectrum analysis.

Aspergillus ochraceus↗

[Immunogenetic markers (BF, C2, C4, 21-OH, TNF alpha, TCR beta, Ig) and insulin-dependent diabetes in the Tunisian population: serological and molecular study].

48 Tunisian people suffering from the IDDM auto-immune disease were compared to 35 control healthy persons for the polymorphisms of the complement BF, C2 and C4 proteins and genes, of the IgG (Gm allotypes) as well as of the TNF alpha and TCR C beta genes. Our study shows that the BFF1-C4A3-C4BQO and BFS-C4AQ0-C4B1 complotypes are associated to IDDM (RR of 2.97 and 3.07 respectively), as previously reported for other circummediterranean populations. The frequency of the Gm 21.28; 1.17; .. haplotype is increased, but not significantly, among the patients. The RFLP analysis reveals that the 2.65 kb SacI allelic restriction fragment of the C2 gene may be considered as a genetic marker of susceptibility to IDDM because its frequency raises to 0.206 among the patients vs 0.021 in the healthy individuals (p less than 0.001). The frequencies of the C4AQ0 and C4BQ0 alleles are more important among the IDDM patients than within the control sample, but the only C4BQ0 allele frequency is significantly increased. Both C4AQ0 and C4BQO result mainly from deletions. The frequencies of the allelic restriction fragments of the TNF alpha and TCRC beta genes are not significantly different among the patients and the controls. But the small sample size don't allow us to conclude definitively. It would be very interesting to extend the RFLP analysis to the TCR V beta and V alpha gene regions on more numerous samples.

Adolescent↗

The peculiar spectrum of beta-thalassemia genes in Tunisia.

We have determined the spectrum of mutations producing beta-thalassemia (beta-thal) in Tunisia by direct DNA analysis using hybridization with allele-specific oligonucleotide probes and restriction endonuclease assay. In all, 34 unrelated beta-thal patients originating from different parts of the country were available for study. The beta-globin gene cluster of each was subjected to haplotype analysis, and on the basis of this analysis, we tested each patient's DNA for one or more mutations previously shown to be linked to that haplotype. We identified four previously unreported haplotypes and found that this population differs from others in Mediterranean areas in the frequency of the beta-thal haplotypes, the unexpected observation being the high frequency of haplotype IX. Six different point mutations were found, accounting for 62% of beta-thal genes in this Tunisian population. The molecular defects known to be the most frequent in Mediterraneans (nonsense codon 39, IVS1 nt 110, IVS1 nt 6) only make up 37% of the mutant genes. One as yet undescribed mutation (IVS1 nt 2 T----G) was identified by molecular cloning and sequencing. Our results should help the implementation of a prenatal diagnosis program for beta-thal in Tunisia.

Genetic Markers↗

[DNA polymorphism in beta-thalassemia: a study of 15 families in Tunisia].

In order to perform prenatal diagnosis of beta-thalassemia by DNA analysis in Tunisia, we investigated molecular defects and their frequencies. We have determined which haplotypes are associated with beta zero or beta +-thalassemia phenotypes. Six of the haplotypes described by Orkin were observed among 15 patients homozygous for beta zero (11) or beta +-thalassemia (4). We also investigated the molecular defects. The frameshift mutation in codon 6, characterized by Mst II seems more frequent than the beta 39 non sense mutation indicating that Tunisian patients differ from other Mediterranean patients from Algeria or Italy. Results concerning beta +-thalassemia are too preliminary to draw any conclusion. The study is currently being enlarged with other molecular probes and restriction enzymes.

DNA↗

Correlation between alimentary mycotoxin contamination and specific diseases.

Several pathological cases including primitive hepatomas, Reye's syndrome, alimentary toxic aleukaemia, were encountered in two different Tunisian Sahel hospitals. Contamination of some nutriments of the patients by mycotoxins (aflatoxins, trichothecenes, ochratoxin A, citrinin) are most likely involved in the origin of these diseases.

Carcinoma, Hepatocellular↗

Gm, Am and Km immunoglobulin allotypes of two populations in Tunisia.

Gm, Am and Km allotypes were investigated in two Tunisian populations (236 samples from Mahdia and 142 samples from Sfax). These populations descend from immigrants and, therefore, the results were compared with those obtained in other populations living in the Near East and in North Africa. The subclass heavy chain allotypes G1m, G2m, G3m and A2m are inherited in fixed combinations. There were five main and four minor Gm-Am haplotypes that could be deduced from the phenotypes. This led to the conclusion that the populations studied are Caucasoids with some African admixture (about 10%) and a very low oriental contribution. Furthermore, there were 11 samples which showed 8 uncommon Gm-Am phenotypes. These could be explained by the assumption of five different uncommon Gm-Am haplotypes. Four of these may have arisen by equal crossing over of prevalent haplotypes. The fifth may be the result of unequal crossing over of prevalent haplotypes. The fifth may be the result of unequal crossing over, since it was proven, by family study, that more markers are transmitted together than are present in the prevalent haplotypes.

Female↗

[The evaluation of mental health among Tunisian students].

Universal studies are an important source of stressor. Students are at high risk for mental disorders. In this study, we seek for psychological distress among Tunisian students, using GHQ (general health questionnaire).

Adult↗

[Study of the sensitivity of non-typhoid salmonellae isolated at Sfax (Tunisia)].

From 1982 to 1986, 122 strains of non-typhoid Salmonellae were isolated at the University Hospital of Sfax (Tunisia). Both tests: serotype classification and sensitivity have demonstrated that the most frequent serotypes: S. wien and S. typhimurium have the highest degree of multiresistance. Ampicillin, cotrimoxazole and chloramphenicol are the most affected while cefotaxime, amikacin and colistin are still saved. Facing these facts, the authors insist on the seriousness of the excessive use of antibiotherapy which leads to the selection of such strains.

Ampicillin↗