10 research outputs found

    Different roles of heat shock proteins (70 kDa) during abiotic stresses in barley (Hordeum vulgare) genotypes

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    In this work, the involvement of heat shock proteins (HSP70) in barley (Hordeum vulgare) has been studied in response to drought and salinity. Thus, 3 barley genotypes usually cultivated and/or selected in Italy, 3 Middle East/North Africa landraces and genotypes and 1 improved genotype from ICARDA have been studied to identify those varieties showing the best stress response. Preliminarily, a bioinformatic characterization of the HSP70s protein family in barley has been made by using annotated Arabidopsis protein sequences. This study identified 20 putative HSP70s orthologs in the barley genome. The construction of un-rooted phylogenetic trees showed the partition into four main branches, and multiple subcellular localizations. The enhanced HSP70s presence upon salt and drought stress was investigated by both immunoblotting and expression analyses. It is worth noting the Northern Africa landraces showed peculiar tolerance behavior versus drought and salt stresses. The drought and salinity conditions indicated the involvement of specific HSP70s to counteract abiotic stress. Particularly, the expression of cytosolic MLOC_67581, mitochondrial MLOC_50972, and encoding for HSP70 isoforms showed different expressions and occurrence upon stress. Therefore, genotypes originated in the semi-arid area of the Mediterranean area can represent an important genetic source for the improvement of commonly cultivated high-yielding varieties

    Clinical Significance of Epigenetic Inactivation of hMLH1 and BRCA1 in Tunisian Patients with Invasive Breast Carcinoma

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    Aberrant hypermethylation of gene promoter regions is one of the mechanisms for inactivation of tumour suppressor genes in many human cancers including breast carcinoma. In the current study, we aimed to assess by MSP, the methylation pattern of two cancer-related genes involved in DNA repair: hMLH1 (mutL homolog 1, colon cancer, nonpolyposis type 2 (E. coli) and BRCA1 (breast cancer 1, early onset) in 78 primary breast cancers from Tunisian patients. The methylation frequencies were 24.36% for hMLH1 and 46% for BRCA1. BRCA1 methylation correlated with age at diagnosis (P = .015) and 5-years disease free survival (P = .016) while hMLH1 methylation was more frequent in larger tumors (P = .002) and in presence of distant metastasis (P = .004). Furthermore, methylation of hMLH1 significantly correlated with high level of P53 expression (P = .006) and with overall survival (P = .015) suggesting that silencing of hMLH1 through aberrant promoter methylation could be used as a poor prognosis indicator in breast cancer

    Physiological and molecular osmotic stress responses in three durum wheat (Triticum turgidum ssp durum) genotypes

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    This study aims to investigate the activities and expression of enzymes of primary metabolism and relate these data with the growth performance of three dierent durum wheat genotypes (Maali; YT13; and ON66) under osmotic stress. Growth traits—including plant height, dry weight (DW) and relative water content (RWC)—were measured to classify genotypes depending on their tolerance to stress. Several enzymes were investigated: Ascorbate peroxidase (APX), Glutamine Synthetase (GS), Glutamine dehydrogenase (GDH), Glutamate synthase (GOGAT), Glucose 6-phosphate dehydrogenase (G6PDH), and Phosphoenolpyruvate Carboxylase (PEPC). The expression of the cytosolic and plastidic glutamine synthetase (TaGS1 and TaGS2), high anity nitrate transporters (TaNRT2.3) and Glutamate dehydrogenase (TaGDH) were also detected by qRT-PCR. The results indicated dierent growth performances among genotypes, indicating Maali and YT13 as tolerant genotypes and ON66 as a drought-susceptible variety. Data showed a decrease in PEPC and increase in APX activities under osmotic stress; a slight decrease in GS activity was observed, together with an increase in G6PDH in all genotypes; GS and NRT2 expressions changed in a similar pattern in the dierent genotypes. Interestingly, Maali and YT13 showed higher transcript abundance for GDH under stress compared to ON66, suggesting the implication of GDH in protective phenomena upon osmotic stress

    Gastrointestinal parasites of canids, a latent risk to human health in Tunisia

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    Abstract Background Although data on the parasite environmental contamination are crucial to implement strategies for control and treatment, information about zoonotic helminths is very limited in Tunisia. Contamination of areas with canid faeces harboring infective parasite elements represents a relevant health-risk impact for humans. The aim of this study was to assess the environmental contamination with eggs and oocysts of gastrointestinal parasites of dogs and wild canids in Tunisia with special attention to those that can be transmitted to humans. Results One thousand two hundred and seventy faecal samples from stray dogs and 104 from wild canids (red foxes and golden jackals) were collected from different geographical regions throughout Tunisia. The helminth eggs and protozoan oocysts were concentrated by sucrose flotation and identified by microscopic examination. The most frequently observed parasites in dog samples were Toxocara spp. (27.2%), E. granulosus (25.8%), and Coccidia (13.1%). For wild canid faeces, the most commonly encountered parasites were Toxocara spp. (16.3%) followed by Capillaria spp. (9.6%). The parasite contamination of dog faeces varied significantly from one region to another in function of the climate. Conclusion To our knowledge, the study highlights for the first time in Tunisia a serious environmental contamination by numerous parasitic stages infective to humans. Efforts should be made to increase the awareness of the contamination risk of such parasites in the environment and implement a targeted educational program

    Negative/Low HER2 expression alone or combined with E-cadherin positivity is predictive of better prognosis in patients with breast carcinoma

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    The loss of E-cadherin expression leads to absence of tissue integrity, an essential step in tumor progression. Methylation of CpG islands in the promoter region of the CDH1 gene coding E-cadherin might be an alternative for gene silencing. In the present study, we investigate the expression of E-cadherin and hormone receptors in invasive ductal breast carcinoma (IDCs). Protein expression was analysed immunohistochemically in 87 cases, including 26 familial tumors. The most interesting results revealed a significantly reduced E-cadherin expression in cases with familial history compared to sporadic tumors (p=0.009), as well as with tumors ≤5cm (p=0.022). Moreover, HER2 over-expression was associated with distant metastasis (p=0.011) and overall survival (p log rank=0.028). Tumors displaying negative/low HER2 expression combined with E-cadherin positivity confer better patient survival (p=0.052). Triple Negative tumors (TN) were more frequently found in patients with advanced grade (GIII) (p=0.001) and TNM (III+IV) (p=0.018) which supports the aggressive behavior of TN tumors. On the other hand, hypermethylation of CDH1 gene promoter was observed in 46% of hereditary cases and strongly associated with loss of E-cadherin expression (p=0.002). Furthermore, patients with unmethylated CDH1 pattern have a better 5-year disease free survival (p=0.021). In conclusion, in patients with hereditary breast cancer, the CpG methylation event contributes to the loss of E-cadherin expression. On the other hand, HER2 over-expression is predictive of worse prognosis, either alone or combined with loss of E-cadherin expression in Tunisian patients with breast cancer

    Microbial diversity and pathogenic properties of microbiota associated with aerobic vaginitis in women with recurrent pregnancy loss

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    Recurrent pregnancy loss (RPL) is a major reproductive problem that affects approximately 5% of couples. The objective of this study was to assess vaginal flora dysbiosis in women suffering from unexplained RPL and to investigate the pathogenic properties of the microbiota associated with aerobic vaginitis (AV). The study included one hundred fifteen women, 65 with RPL and 50 controls. The diversity of vaginal microbiota isolated was evaluated by molecular sequencing. Then, pathogenic factors, such as acid-resistance, antibiotics susceptibility, and biofilm formation were evaluated. The prevalence of AV was five-fold higher in the RPL group than in the controls (64.6% vs. 12.0%). The most prevalent isolates in the case group were Enterococcus spp. (52%) and Staphylococcus spp. (26%). All bacterial strains tolerate low pH. The prevalence of multidrug resistance (MDR) among all bacteria was 47.7%. Of all strains, 91.0% were biofilm producers. The presence of MDR was found to be related to biofilm formation. The results provide evidence supporting an increased presence of dysbiosis of the vaginal flora, especially AV, in women with RPL in Tunisia. The viability of the AV-associated bacteria and their persistence in the genitals may be due to their ability to resist low pH and to produce a biofilm

    Assessment of natural coagulants to remediate Tunisian textile wastewater by combining physicochemical, analytical, and toxicological data

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    Due to the complexity and variability of textile wastewater composition, a constant search for new treatment strategies that are efficient, eco-friendly, and cost-effective is mandatory. In the present study, the efficiency of coagulation-flocculation using biocoagulants derived from cactus Opuntia ficus indica and eggplant Solanum melongena to remove toxic compounds from Tunisian textile wastewater samples was evaluated by combining assays to investigate physicochemical properties and in vitro (geno)toxicity with analytical chemistry. Both natural coagulants could significantly improve the physicochemical properties of the textile wastewater samples compared to the traditionally used chemical coagulant. The highest rate of decolorization was achieved after treatment with the cactus-derived coagulant. The analytical study revealed the presence of only crystal violet dye (CV) in only one sample. Both natural coagulants were able to remove CV, which may (partially) explain the decolorization of the treated samples. Only one untreated textile effluent induced a genotoxic response in the VITOTOX®&nbsp;assay. The genotoxic effect was not linked to the presence of CV and was no longer observed after treatment with each of the natural coagulants, suggesting the effectiveness of the remediation treatments to remove potentially genotoxic compound(s). However, in the other genotoxicity tests, no biologically relevant effects were observed for any of the tested samples. In conclusion, although the physicochemical data indicate that the use of natural coagulants (cactus and eggplant) could be an interesting alternative treatment process to the chemical coagulant for detoxifying textile effluents, these results were only partially supported by the toxicological and analytical&nbsp;data.</p

    Variation of Grain Yield, Grain Protein Content and Nitrogen Use Efficiency Components under Different Nitrogen Rates in Mediterranean Durum Wheat Genotypes

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    Nitrogen (N) is a crucial nutrient for plant growth and development. To optimize agricultural environments, N fertilizers represent a critical tool to regulate crop productivity. The improvement of nitrogen use efficiency (NUE) represents a promising tool that may enable cereal production to meet future food demand. Wheat reported contrasting behaviors in N utilization showing specific abilities depending on genotype. This study selected two landraces and two improved genotypes from Northern Africa to investigate grain yield (GY), grain protein content (GPC) and NUE. Plants were grown under three levels of N supply: 0, 75, 150 kg N ha&minus;1 and for two consecutive years. Results reported a better NUE (0.40 kg kg N&minus;1) obtained under 150 kg N ha&minus;1, while N utilization efficiency (NUtE) showed a 13% increase using 75 kg N ha&minus;1 compared with 150 kg N ha&minus;1. Under low nitrogen rate (0 N), crop N supply (CNS) and N uptake efficiency (NUpE) were shown as determinant factors for improved genotypes GY (R2 = 0.72), while NUtE represented the most determinant component for GPC in landraces (R2 = 0.92). Multivariate regression models explained the dependence in GPC on NUE, NUpE, and NUtE. In conclusion, our results recognize GPC and NUtE as suitable selection traits to identify durum wheat with higher NUE
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