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1.
Sahli C. Bahri W. Fredj S. H. Dabboubi R. Bousseta K. Mehrzi A. Messaoud T. 《Russian Journal of Genetics》2019,55(6):756-761
Russian Journal of Genetics - The aim of this study was to determine a possible association of IVS3 poly A and IVS10 CA microsatellites with CF in case–control Tunisian groups and to compare... 相似文献
2.
Ben Fredj R Gross E Chouchen L B'Chir F Ben Ahmed S Neubauer S Kiechle M Saguem S 《Comptes rendus biologies》2007,330(10):764-769
Dihydropyrimidine dehydrogenase enzyme (DPD) deficiency is a pharmacogenetic syndrome leading to severe side-effects in patients receiving therapies containing the anticancer drug 5-fluorouracil (5-FU). The aim of this population study is to evaluate gene variations in the coding region of the dihydropyrimidine dehydrogenase gene (DPYD) in the Tunisian population. One hundred and six unrelated healthy Tunisian volunteers were genotyped by denaturing HPLC (DHPLC). Twelve variants in the coding region of the DPYD were detected. Allele frequencies of DPYD*5 (A1627G), DPYD*6 (G2194A), DPYD*9A (T85C), A496G, and G1218A were 12.7%, 7.1%, 13.7%, 5.7%, and 0.5%, respectively. The DPYD alleles DPYD*2A (IVS 14+1g>1), DPYD*3 (1897 del C) and DPYD*4 (G1601A) associated with DPD deficiency were absent from the examined subjects. We describe for the first time a new intronic polymorphism IVS 6-29 g>t, found in an allelic frequency of 4.7% in the Tunisian population. Comparing our data with that obtained in Caucasian, Egyptian, Japanese and African-American populations, we found that the Tunisian population resembles Egyptian and Caucasian populations with regard to their allelic frequencies of DPYD polymorphisms. This study describes for the first time the spectrum of DPYD sequence variations in the Tunisian population. 相似文献
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Abdellatif Boudabous Fredj Tekaia 《BioEssays : news and reviews in molecular, cellular and developmental biology》2020,42(10):2000134
Reading, writing, publishing, and publicly presenting scientific works are vital for a young researcher's profile building and career development. Generally, the traditional educational curricula do not offer training possibilities to learn and practice how to prepare, write, and present scientific works. These are rather a part of lab meeting activities in research groups. The lack of such training is more critical in some developing countries because this adds to the rare opportunities to discuss and become involved in the exchanges on state of the art scientific literature. Here the authors relate their experience in introducing a weekly 1-day lab meeting in the framework of two previously organized 3-month courses on “Bioinformatics and Genome Analyses”. The main activities which are developed during these lab meetings include scientific literature follow up as well as preparing and presenting oral and written scientific reviews. These activities prove to be useful for a student's self-confidence building, for enhancing their active participation during the lectures and practical sessions, as well as for the positive impact on running the whole course program. Incorporation of such lab meeting activities in the course program significantly improves the capacity building of the participants, their analytical and critical reading of scientific literature, as well as communication skills. In this work it is shown how to proceed with the different steps involved in the implementation of lab meeting activities, and to recommend their regular institution in similar courses. 相似文献
5.
In cardiac hypertrophy, both excessive enlargement of cardiac myocytes (CMs) and progressive fibrosis are known to occur simultaneously. To investigate the nature of interactions between ventricular CMs and cardiac fibroblasts (CFs) in these conditions, we have established a "dedifferentiated model" of adult murine CMs in coculture with CFs. In such a model, which is recognized to study cardiac cell hypertrophy in vitro, dedifferentiated CMs in culture and in coculture were characterized by immunopositive staining to ANP (atrial natriuretic peptide) and beta-myosin heavy chain (beta-MHC). The results confirm that ANP secretion by CMs was significantly increased during the cultures. The increase size of cultured CMs was significantly higher in CM/CF cocultures than in CM cultures which was also observed when CMs were cultured with fibroblast conditioned medium (FCM). In addition, fibroblast proliferation studies showed that CMs favored fibroblast adhesion and/or growth at the beginning of the coculture and fibroblast proliferation throughout the time course of the coculture. Furthermore, a significant level of interleukin-6 (IL-6) production was detected by ELISA in CM/CF cocultures. A similar higher increase was observed when CMs were cultured in the presence of FCM. These results demonstrate that CFs enhance myocyte hypertrophy and that CMs regulate fibroblast adhesion and/or proliferation, suggesting a paracrine interaction between CMs and CFs which could involve IL-6. 相似文献
6.
Hannachi N Bahri O Ben Fredj N Boukadida J Triki H 《Archives de l'Institut Pasteur de Tunis》2010,87(1-2):17-24
The risk of vertical transmission of hepatitis B virus (HBV) varies with type of viral endemicity, degree of maternal infection and genomic characteristics of the virus. The aim of this study is to estimate this risk in Tunisia using serological and molecular methods to evaluate HBV replication, to determine viral genotypes and to detect presence of occult hepatitis in 2709 pregnant women. Serological markers were detected by ELISA methods, Genotype was determined by PCR-RFLP and occult hepatitis by nested-PCR. Four percent of women were positive for HBsAg; only 3% of them were also positive for HBeAg. Viral replication, over than 10(3) copies/ml, was detected in 61% of positive HBsAg patients. Three viral genotypes were detected: D (95%), B (3%) and A (3%). Occult hepatitis was detected in 4% of sera with "anti-HBc isolated" profile. In conclusion, the risk of vertical transmission of HBV exists in Tunisia. It increases by frequency of precore mutants, predominance of the genotype previously associated with high levels of replication and possibility of occult hepatitis B. These results show the importance of screening by serological HBV markers systematically during pregnancy with evaluation of viral replication in order to prevent vertical risk by efficient tools. 相似文献
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Replication slippage may cause parallel evolution in the secondary structures of mitochondrial transfer RNAs 总被引:9,自引:4,他引:5
Presence of the dihydrouridine (D) stem in the mitochondrial cysteine tRNA
is unusually variable among lepidosaurian reptiles. Phylogenetic and
comparative analyses of cysteine tRNA gene sequences identify eight
parallel losses of the D-stem, resulting in D-arm replacement loops.
Sampling within the monophyletic Acrodonta provides no evidence for
reversal. Slipped-strand mispairing of noncontiguous repeated sequences
during replication or direct replication slippage can explain repeats
observed within cysteine tRNAs that contain a D-arm replacement loop. These
two mechanisms involving replication slippage can account for the loss of
the cysteine tRNA D-stem in several lepidosaurian lineages, and may
represent general mechanisms by which the secondary structures of
mitochondrial tRNAs are altered.
相似文献
8.
In this work detailed statistics on ancestral gene duplication and gene conservation in completely sequenced cellular genomes
are presented. Analysis of open reading frame (ORF) products having simultaneous matches in several distinct organisms showed
a significant correlation between duplication and conservation. Systematic comparisons of predicted proteomes of 23 organisms
(including 20 that have been completely sequenced), have allowed us to quantify the degree of ancestral duplication within
each genome and the level of conservation between genomes, using threshold values calculated for individual organisms. Statistical
analysis of various gene proportions revealed interesting trends in gene structure and evolution, such as that (a) more than
one-quarter (25%–66%) of the predicted ORF products of the surveyed organisms are not unique, indicating a high level of ancestral
duplications; (b) levels of exclusive conservation within Bacteria are higher than those within the eukaryal or archaeal domains;
and (c) at least one-half (47–99%) of the total predicted ORF products in the surveyed genomes have one or several highly
significant matches in another genome. Significant matches are based on simulations taking into account the mean size of ORF
products and the composition of each target organism's proteome. The methodology we have developed ensures stability and comparability
of our results as the number of completely sequenced genomes increases.
Received: 4 May 1998 / Accepted: 28 September 1998 相似文献
9.
Editorial
A new feature: special issues 相似文献10.
The complete cDNA sequence and protein reading frame of a developmentally
regulated hemocyanin subunit in the Dungeness crab (Cancer magister) is
presented. The protein sequence is aligned with 18 potentially homologous
hemocyanin-type proteins displaying apparent sequence similarities.
Functional domains are identified, and a comparison of predicted
hydrophilicities, surface probabilities, and regional backbone
flexibilities provides evidence for a remarkable degree of structural
conservation among the proteins surveyed. Parsimony analysis of the protein
sequence alignment identifies four monophyletic groups on the arthropodan
branch of the hemocyanin gene tree: crustacean hemocyanins, insect
hexamerins, chelicerate hemocyanins, and arthropodan prophenoloxidases.
They form a monophyletic group relative to molluscan hemocyanins and
nonarthropodan tyrosinases. Arthropodan prophenoloxidases, although
functionally similar to tyrosinases, appear to belong to the arthropodan
hexamer- type hemolymph proteins as opposed to molluscan hemocyanins and
tyrosinases.
相似文献