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The objective of this study was to compare the prevalence of human rotavirus group A common G and P genotypes in human Egyptian stool specimens and raw sewage samples to determine the most common genotypes for future vaccine development. From 1026 stool specimens of children with acute diarrhea and using nested RT-PCR, 250 samples (24.37%) were positive for human rotavirus group A. Using multiplex RT-PCR, rotavirus common P and G genotypes were detected as 89.20% and 46.40% of the positive clinical specimens respectively. This low percentage of common G genotypes frequency may affect the efficiency of the available live attenuated oral rotavirus vaccines [Rotarix® (human rotavirus G1P[8]) and RotaTeq® (reassortant bovine–human rotavirus G1-4P[5] and G6P[8])], however the percentage of clinical specimens which were negative for common G genotypes but positive for P[8] genotype was 12.00%. From 24 positive raw sewage samples for rotavirus group A VP6 collected from Zenin and El-Gabal El-Asfar wastewater treatment plants (WWTPs), 21 samples (87.50%) were typeable for common P genotypes while 13 samples (54.17%) were typeable for common G genotypes. Phylogenetic analysis of a VP8 partial gene of 45 P-typeable clinical isolates and 20 P-typeable raw sewage samples showed high similarity to reference strains and the majority of mutations were silent and showed lower to non-significant similarity with the two vaccine strains. This finding is useful for determining the most common antigens required for future vaccine development.

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23.
The purpose of this paper is to investigate activities of research transfer, the extent of the use of these activities, and the research transfer determinants. This study is based on a population of more than 400 researchers in the field of occupational safety and health (OSH) in Canada, who completed an electronic questionnaire. The results show notably that there is no significant statistical difference between fields for the four activities of research transfer and that several factors have a significant impact on research transfer. Researchers in OSH constituted a rather homogenous unit and can improve the research transfer notably by the adaptation of knowledge, by focusing the research on users’ needs and by improving their link with users.  相似文献   
24.
Recent reports have indicated an increased risk for fetal chromosome abnormalities, especially autosomal trisomy, in fetuses with isolated cystic hygroma, or prominent nuchal membranes, detected by ultrasonography during the first trimester. However, these reports present contradictory information regarding the prognostic significance of septations within the cystic hygroma. We evaluated, in blind fashion, 55 consecutive cases of isolatd fetal cystic hygroma detected at or before 13·9 weeks' gestation to determine the association between septations and fetal chromosome complement. Septations were associated (P<0·05) with an increased risk for fetal chromosome abnormalities. However, the incidence of chromosome abnormalities was also increased (12·5 per cent) among cases not characterized by septations. Thus, we believe it prudent to offer invasive prenatal testing to all women found to be carrying fetuses with cystic hygroma, irrespective of the presence or absence of septations.  相似文献   
25.
Hepatitis E virus (HEV) is a fecal-orally transmitted virus that is endemic in many geographical areas with poor sanitary conditions and inadequate water supplies. In Europe, a low-endemic area, an increased number of autochthonous sporadic human cases of patients infected with HEV strains of genotype 3, have been reported lately. The relatively high prevalence of HEV genotype 3 infections in European pigs has raised concerns about a potential zoonotic transmission to humans. Determination of HEV seroprevalence in pigs would help to clarify its incidence and possible zoonotic implications. To this purpose, we have expressed and partially characterized swine genotype 3 HEV open reading frame-2 proteins upon infection of Sf21 insect cells with recombinant baculoviruses. The use of the expressed proteins as diagnostic antigens for the detection of antibodies to HEV has been further assayed with human and swine sera.  相似文献   
26.
The aim of this study is to assess the response of a multimarker approach in common carp Cyprinus carpio sampled from three Tunisian dam lakes selected according to different environmental and ecological characteristics. Glutathione-S-transferase (GST) activity was analyzed in carp liver and used as a phase II detoxification enzyme, hepatic metallothionein content (MTs) was used as a metallic stress indicator, and cholinesterase activities were analyzed in muscle and brain and used as neurotoxicity biomarker. Micronucleus frequency test (MN) as a genotoxicity marker. GST and MT levels showed an increase in fish from the Bir Mcherga site and a decrease in Sidi Saâd site with respect to fish from Nebhana site. Results showed a strong inhibition of cholinesterase activities in fish from Bir Mcherga and Sidi Saâd sites compared to Nebhana site. Relatively high level of MN is reported specially in fish blood from the Bir Mcherga site.  相似文献   
27.
The environment is witnessing a downgrade caused by the amelioration of the industrial and agricultural sectors, namely, soil and sediment compartments. For those reasons, a comparative study was done between soil cores and sediments taken from two locations in the Qaraaoun reservoir, Lebanon. The soil cores were partitioned into several layers. Each layer was analyzed for several physicochemical parameters, such as functional groups, particle size distribution, ζ-potential, texture, pH, electric conductivity, total dissolved solids, organic matter, cation exchange capacity, active and total calcareous, available sodium and potassium, and metal content (cadmium, copper, and lead). The metal content of each site was linked to soil composition and characteristics. The two sites showed distinguishable characteristics for features such as organic matter, pH, mineral fraction, calcareous, and metal content. The samples taken toward the south site (Q1), though contain lower organic matter than the other but are more calcareous, showed higher metal content in comparison to the other site (Q2) (average metal content of Q1 > Q2; for Cd 3.8?>?1.8 mg/kg, Cu 28.6?>?21.9 mg/kg, Pb 26.7?>?19 mg/kg). However, the metal content in this study did not correlate as much to the organic matter; rather, it was influenced by the location of the samples with respect to the dam, the reservoir’s hydrodynamics, the calcareous nature of the soil, and the variation of the industrial and agricultural influence on each site.  相似文献   
28.
The aim of this study was to determine a new spectrum of substances that will be selected for future breast milk monitoring in Bavaria, Germany. Up to now, the analysis of breast milk in Bavaria was limited to selected organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB). Information on background levels of toxicologically interesting substances, such as dioxins and dioxin-like polychlorinated biphenyls (dl-PCB) or on flame retardants, such as polybrominated diphenyl ethers (PBDE) are very limited or not available for Bavaria. We present here levels on OCP, some nitro musks, indicator PCB, polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dl-PCB concentrations in breast milk collected at 12 weeks post-partum of 43 primiparous mothers living in Bavaria. The average concentrations of PCDD, PCDF and dl-PCB were 4.98, 4.93 and 9.92 pg WHO-TEQ g(-1) lipid, respectively. The mean contribution of PCDD, PCDF, non-ortho and mono-ortho PCB to the total WHO-TEQ is consistently about 25% each. Furthermore the concentration on PBDE in breast milk at two sampling points, 12 weeks and 16 weeks after delivery, were determined. Overall, 19 PBDE congeners were analysed, however the level of 12 PBDE congeners were below the limit of detection. BDE-153 and BDE-47 were the predominant congeners accounting for about 66% of the total PBDE. The means of the total concentrations of PBDE (five congeners) at the first and second sampling point were 1.90 and 2.03 ng g(-1) lipid, respectively. Based on our results the overall concentrations of the analysed substances in milk samples from Bavaria are consistent with the levels of breast milk samples of other European countries reflecting the low background body burden of these compounds.  相似文献   
29.
Understanding the ecological status of aquatic ecosystems and the impact of anthropogenic contamination requires correlating exposure to toxicants with impact on biological communities. Several tools exist for assessing the ecotoxicity of substances, but there is still a need for new tools that are ecologically relevant and easy to use. We have developed a protocol based on the substrate-induced respiration of a river biofilm community, using the MicroResp™ technique, in a pollution-induced community tolerance approach. The results show that MicroResp™ can be used in bioassays to assess the toxicity toward biofilm communities of a wide range of metals (Cu, Zn, Cd, Ag, Ni, Fe, Co, Al and As). Moreover, a community-level physiological profile based on the mineralization of different carbon substrates was established. Finally, the utility of MicroResp™ was confirmed in an in-situ study showing gradient of tolerance to copper correlated to a contamination gradient of this metal in a small river.  相似文献   
30.
Removal of carbamazepine from urban wastewater by sulfate radical oxidation   总被引:2,自引:0,他引:2  
The occurrence of bioactive trace pollutants such as pharmaceuticals in natural waters is an emerging issue. Numerous pharmaceuticals are not completely removed in conventional wastewater treatment plants. Advanced oxidation processes may represent an interesting alternative to completely mineralize organic trace pollutants. In this article, we show that sulfate radicals generated from peroxymonosulfate/CoII are more efficient than hydroxyl radicals generated from the Fenton’s reagent (H2O2/FeII) for the degradation of the pharmaceutical compound, carbamazepine. The second-order rate constant for the reaction of SO4 ·− with carbamazepine is 1.92·109 M−1 s−1. In laboratory grade water and in real urban wastewater, SO4 ·− yielded a faster degradation of carbamazepine compared to HO· . Under strongly oxidizing conditions, a nearly complete mineralization of carbamazepine was achieved, while under mildly oxidizing conditions, several intermediates were identified by LC–MS. These results show for the first time in real urban wastewater that sulfate radicals are more selective than hydroxyl radicals for the oxidation of an organic pollutant and may represent an interesting alternative in advanced oxidation processes.  相似文献   
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