Search

This study investigated the presence and origin of hydrocarbon pollution in industrial waste water sediments found near the Jarzouna (Bizerte, Tunisia) oil refinery. Analyses of surface sediments (layer 1) and deep sediments (layer 2) showed that Total Hydrocarbon (TH) concentrations ranged from 602 ± 7.638 μg/g in layer-1 to 1270 ± 2.176 μg/g in layer-2. The results suggest that the deeper the sediment, the higher the level of total hydrocarbon found. The sedimentary Non Aromatic Hydrocarbon (NAH) and Aromatic Hydrocarbon (AH) concentrations ranged from 66.22 ± 1.516 to 211.82 ± 10.670 μg/g for NAH, and from 13.84 ± 0.180 to 115.60 ± 2.479 μg/g for AH. The high variability of these concentrations was associated with the location of the sediment collection sites. Aliphatic biomarker analysis revealed petroleum contamination close to the refinery rejection site, and biogenic sources further away. Petroleum contamination may be associated with increased industrial activity in the area of Jarzouna-Bizerte in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Background: Among polymorphisms of non-transcribed DNA sequences and functional genes, those of Alu insertions and that of the APOE gene have been widely used to clarify the degree of genetic relationships between human populations. Aim: APOE gene and eight Alu insertion polymorphisms were investigated in Tunisians and compared with data from neighbour populations in order to gain new insights into the genetic position of Tunisia in the Mediterranean region. Subjects and methods: A total of 121 individuals from the North and Centre-South regions were sampled. Results: No significant genetic differences were found between Tunisians and North Africans when samples representative of wide areas were considered. APOE gene variation seemed slightly less powerful than the Alu polymorphisms in detecting North-South Mediterranean differences. Conclusion: North African populations show a substantial degree of genetic homogeneity, which may reflect the similarity of their origins, mainly when samples from large geographical areas are compared. The relative genetic homogeneity of the whole Mediterranean region probably reflects a common origin and/or remarkable levels of gene flow. However, this gene flow has not yet erased the differentiation between the two Mediterranean shores, as revealed by Alu insertion polymorphisms. [ABSTRACT FROM AUTHOR]

During successive historical periods, Tunisia has been a crossroads of multiple civilizations and their corresponding key population movements. The aim of this study was to provide genetic information relating to the mixed origin of the Tunisian population, and to analyze its genetic relationship with other North African and Mediterranean populations. A set of 16 Alu and 3 Alu/STR compound systems has been analyzed in 268 autochthonous Tunisians from the north-center and the south of the country. Our two sampled populations showed no significant differentiation from one another in any of the three Alu/STR compound systems, whereas the analysis of the 16 Alu markers revealed a significant genetic differentiation between them. A sub-Saharan component shown by the three Alu/STR combinations is more noticeable in our north-center sample than in that of the south. The presence of two Alu/STR combinations specific to North African ancestral populations also suggests that the ancient Berber component is relatively more substantial in the north and center regions than in the south. Our Tunisian samples cluster together with other Berber samples from Morocco and Algeria, underpinning the genetic similarity among North Africans regardless of their current linguistic status (Berber or Arabic).

This study was designed to investigate the interaction between C. parapsilosis and human epithelial cells using monolayer cultures and an engineered human oral mucosa (EHOM). C. parapsilosis was able to adhere to gingival epithelial cells and to adopt the hyphal form in the presence of serum. Interestingly, when cultured onto the engineered human oral mucosa (EHOM), C. parapsilosis formed small biofilm and invaded the connective tissue. Following contact with C. parapsilosis, normal human gingival epithelial cells expressed high levels of Toll-like receptors (TLR)-2, -4, and -6, but not TLR-9 mRNA. The upregulation of TLRs was paralleled by an increase of IL-1beta, TNFalpha, and IFNgamma mRNA expression, suggesting the involvement of these cytokines in the defense against infection with C. parapsilosis. The active role of epithelial cells in the innate immunity against C. parapsilosis infection was enhanced by their capacity to express high levels of human beta-defensin-1, -2, and -3. The upregulation of proinflammatory cytokines and antimicrobial peptide expression may explain the growth inhibition of C. parapsilosis by the gingival epithelial cells. Overall results provide additional evidence of the involvement of epithelial cells in the innate immunity against C. parapsilosis infections.

Aim: To analyze apolipoprotein gene polymorphisms in the Tunisian population and to check the relation of these polymorphisms and homocysteine, lipid and apolipoprotein levels to the coronary artery disease (CAD)., Methods: In healthy blood donors and in patients with CAD complicated by myocardial infarction (MI) four apolipoprotein gene polymorphisms [APO (a) PNR, APO E, APO CI and APO CII] were determined and plasma levels of total homocysteine, total cholesterol (TC), triglycerides (TG), HDL-cholesterol (HLD-C) and apolipoproteins (apo A-I, Apo B, Apo E) were measured., Results: Analysis of the four apolipoprotein gene polymorphisms shows a relative genetic homogeneity between Tunisian population and those on the other side of Mediterranean basin. Compared to controls, CAD patients have significantly higher main concentrations of TC, TG, LDL-C, apo B and homocysteine, and significantly lower ones of HDL-C, apo A-I and apo E. The four apolipoprotein gene polymorphisms have not showed any significant differences between patients and controls. However, the APO E4 allele appears to be associated to the severity of CAD and to high levels of atherogenic parameters and low level of apo E, which has very likely an anti-atherogenic role., Conclusion: Although APO (a) PNR, APO CI and APO CII genes are analyzed in only few populations, they show a frequency distribution, which is not at variance with that of APO E gene and other widely studied genetic markers. In the Tunisian population the APO E 4 appears to be only indirectly involved in the severity of CAD. In the routine practice, in addition of classic parameters, it will be useful to measure the concentration of apo E and that of Homocysteine and if possible to determine the APO E gene polymorphism.

Acute severe asthma is the most severe acute complication of infant asthma. The aim of our study was to specify its characteristics in the Tunisian infant and analysis his initial medical care. It is a retrospective study included 34 infants less than 3 year old, admitted during the period from January 1, 1995 to December 31, 2000. The acute severe asthma was induced by a respiratory viral infection in 80 % of cases. The delay hospitalisation was upper than 48 hours in 56 % of the cases. Before admission, corticosteroids were not instituted in 84 % of the cases. The initial examination noted neurological disorders in 52 % of cases and hemodynamic disorders in 8 % of cases. All patients received beta2 adrenergic and intravenous corticosteroids. Intravenous aminophylline was used in 68 % of patients. Mechanical ventilation was necessary among 6 patients. The evolution was complicated: pneumothorax (3 cases), hypokaliemia (3 cases), inappropriate secretion of ADH syndrome (1 case). There were 2 deaths. Acute severe asthma forces a correct evaluation of the severity of the asthmatic disease in order to adapt the long-term therapy.