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Purpose: The aim of this study was to assess the presence of T. gondii,Cryptosporidium spp. oocysts, and G. duodenalis cysts, in three leafy greens (coriander, lettuce, and parsley) commonly consumed raw. Despite the recognition of the association between the parasitic illnesses and the consumption of contaminated food, there is still a lack of studies investigating the occurrence of parasitic contamination in food matrices. Methods: A total of 152 leafy green samples were collected in Marrakech from April 2018 to October 2019. Parasites were eluted and concentrated before detection of their DNA by real-time qPCR. Results: The analysis revealed an overall rate of contamination of 32.2% (49/152), with 29.6% (45/152) positive for T. gondii and 2.6% (4/152) for G. duodenalis, while none was positive for Cryptosporidium spp. Conclusion: The results showed that humans can be exposed to protozoan parasites through vegetables consumption. Further investigations can be performed to acquire new epidemiological data to assess the public health impact of these protozoan diseases in Morocco. [ABSTRACT FROM AUTHOR]

Portmán Bay in Southern Spain is one of the most extreme cases in Europe of anthropogenic impact on the marine ecosystem by the disposal of mine tailings resulting from the processing of sulphide ores. First, the composition and extent of the surficial deposit were investigated from geochemical and metal analysis on high spatial density of sediment samples. Then, a disturbance experiment was conducted in the coastal area off Portmán Bay in order to investigate the potential impact of mining activities on marine ecosystems. Two research vessels were used for that experiment, one performing as a trawler resuspending bottom sediments while the other monitor the behaviour of turbid plumes thus generated and the evolution of their characteristics through time by using a range of acoustic and optical tools together with water and bottom sediment sampling for biogeochemical and metal analyses. The surficial part of the submarine extension of the mine tailings deposit is highly concentrated in As, Cd, Pb, Fe and Zn with peak concentrations adjacent to the present coastline, from where they decrease seawards before reaching average values for the Mediterranean Sea around 50-m water depth. The artificially triggered resuspension of the surface layer of the deposit led to the formation of resuspension plume about 100 m in width and up to 6 m in height. Resuspended plume was composed of fine particles which rapidly aggregated into flocs of 100 μm. While the biggest particles settled rapidly, the finest fraction remained in suspension during at least 3 h. Resuspended sediment and metal concentrations in particles remained at relatively high levels throughout the experiments following triggering. Fe, Pb, and As concentrations in resuspended particles showed a continuous increase while trawling before decreasing in parallel with the settling down of the resuspended sediments. Those metals have higher affinity with fine particles than with coarse ones, so that while the coarsest fraction from sediment plumes settled first, the finest fraction remained in suspension thus increasing the metals/sediments concentration ratio. On the other hand, Cd and Zn concentrations in suspended particles did not change significantly over time, which is thought to be caused by the fast dissolution of such metals in seawater. Beyond waste dumping itself, the observed increase in some metals in marine particulate material could have a significant impact on the adjacent coastal ecosystems due to their toxicity above certain thresholds. The consequences of the resuspension experiment here presented can be extrapolated to the impact of seafloor mining activities leading to the resuspension of metal-rich particle plumes into the water column. The experimental set-up presented here may be further explored for investigating metal behaviour during seafloor mining activities. [ABSTRACT FROM AUTHOR]

Cheliff River is the most important permanent river of North-west Algeria which plays an essential role for irrigation and drinking water supply, but suffers from high anthropogenic pressure. Multi-dimensional and multi-factorial aspects of water pollution in Cheliff River and its tributary Mina River were evidenced during two contrasting climatic seasons. Urban discharges were identified as a major source of water organic pollution. The inputs of untreated sewages were characterized by maximum concentrations of tryptophan-like (5.7 µmol l−1) and tyrosine-like (9.8 µmol l−1) compounds during the dry period, confirming these amino acids as fingerprints of untreated urban discharges. The synchronous monitoring and assessment of physicochemical parameters, fluorescent organic compounds and metallic elements of Cheliff River waters highlighted its global contamination, mainly in its downstream part. Cheliff River was mainly affected by organic pollution with maximum COD (1536 mg O2 l−1) and BOD5 (12 mg O2 l−1) during the wet period, and by metallic contamination with maximum Fe (287 ± 4.4 µg l−1) and Al (422.4 ± 9.4 µg l−1) during the dry period, exceeding the guideline limits. This chronic contamination was related to untreated domestic sewages, agricultural effluents and technical landfill center discharges in this area. Diffuse pollutions were also evidenced, which made the identification of different contamination sources complicated. Mina River was mostly affected by non-treated domestic sewages with maximum COD (3161 mg O2 l−1) during the wet period and maximum BOD5 (12 mg O2 l−1) during the dry period, exceeding the guideline limits. The correlation Li/Sr showed the contribution of natural influence from saline soils of Mina valley, particularly during the dry period. Article Highlights: Cheliff River is an essential water resource for drinking water and irrigation. Cheliff River suffers from high anthropogenic pressure. Untreated sewages were directly discarded into the Cheliff River. Synchronous monitoring and assessment of physicochemical parameters, fluorescent organic compounds and metallic elements were conducted. Urban discharges were identified as a major source of water organic pollution. Contribution of natural influence (Li, Sr, SO42− and Cl−) from saline soil of the watershed was studied. [ABSTRACT FROM AUTHOR]

Information on the viability of Toxoplasma gondii oocysts is crucial to establish the public health significance of this environmental transmission stage that can contaminate water and foods. Interest for molecular-based methods to assess viability is growing and the aim of our study was to assess, for the first time, a propidium monoazide (PMA)-qPCR approach to determine the viability of T. gondii oocysts. Untreated and heat-killed (99 °C, 5 min) oocysts were incubated with PMA, a photoreactive DNA binding dye, and analyzed by confocal microscopy and flow cytometry to characterize oocysts' dye permeability. Different PMA concentrations (50 to 150 μM), incubation temperatures (22, 37, and 45 °C), amplicon length, selected targeted gene, and dyes (PMA, PMAxx™) were evaluated to define optimal conditions to discriminate specifically viable oocysts by PMA-qPCR. In theory, PMA binding to DNA would inhibit PCR amplification in dead but not in viable oocysts. Incubation at 22 °C with 100 μM PMA coupled to qPCR targeting a 123-bp sequence of the 529-bp repeat element allowed the distinction between viable and heated oocysts. However, the reduction of viability following heating of oocysts at high temperature was slight and, contrarily to reverse transcriptase-qPCR, the qPCR signal was not totally suppressed in heated suspensions. Therefore, PMA-qPCR is able to assess the impact of heating on T. gondii oocysts' viability but underestimates the efficacy of this treatment. The relevance of this technique to evaluate the efficacy of other inactivation processes and assess exposure of humans to this pathogen requires further investigations. [ABSTRACT FROM AUTHOR]

Little is currently known of clinical toxoplasmosis in humans and animals in the Caribbean. We investigated the prevalence of IgG and IgM antibodies in 437 pregnant women from 10 English speaking Caribbean countries. Overall, antibodies (IgG) to Toxoplasma gondii (modified agglutination test, MAT, cut-off 1:6) were found in 174 (39.8 %) of 437 human sera; specifically 12 of 38 from Antigua-Barbuda, 26 of 52 from Belize, 9 of 50 from Bermuda, 29 of 49 from Dominica, 18 of 49 from Grenada, 16 of 47 from Jamaica, 5 of 15 from Montserrat, 8 of 44 from St. Kitts/Nevis, 24 of 45 from St. Lucia, and 27 of 50 from St. Vincent/Grenadines were seropositive. All IgG-positive sera were tested for IgM antibodies using the immunocapture method; all sera were negative for IgM antibodies. Additionally, tissues and sera of 45 dogs from St. Kitts were examined for T. gondii infection. Antibodies (IgG, MAT, 1:≥25) were found in 19 (42.2 %) of 45 dogs. Muscle samples (tongue, leg) of 19 seropositive dogs were digested in pepsin, and homogenates were bioassayed in mice. Viable T. gondii were isolated from 6 dogs. T. gondii isolates were further propagated in cell culture. PCR-RFLP genotyping of cell culture derived tachyzoites using 10 genetic markers, SAG1, SAG2 (5′ and 3′ SAG2, and alt.SAG2) SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed that 4 isolates were ToxoDB PCR-RFLP genotype #2, and 2 were new genotypes #264 and #265. Review of 22 viable T. gondii isolates from chickens, dogs, and cats from Grenada and St. Kitts revealed that 1 isolate was type II, 13 were type III, and 8 were atypical. Thus, type III strains were predominant. Overall, the study revealed high prevalence of T. gondii in the Caribbean islands. [ABSTRACT FROM AUTHOR]

Environmental characteristics in water and sediments of two contrasted coastal Mediterranean lagoons, Bages-Sigean and Canet-St Nazaire, were measured over a three season survey. The urban pollution (treatment plant discharges) is very important in Canet-St Nazaire lagoon reflecting untreated sewages, while in Bages-Sigean, the northern part appears more impacted due to larger anthropogenic inputs. Dissolved Cd concentrations are on the whole similar in both lagoons, whereas Cu concentrations are by far higher in lagoon Canet-St Nazaire. Cu concentrations appear to be highly dependent on dissolved organic carbon whereas salinity seems to control Cd variations. Concerning the sediments, the confined northern part of lagoon Bages-Sigean shows organic carbon and total nitrogen enrichment whereas lipid concentrations are much higher in the Canet-St Nazaire lagoon. Cu complexation seems to be strongly related to organic matter as evidenced by the two significant positive relationships, on one hand between Cu and organic carbon, and on the other hand, between Cu and lipids. On the contrary, Cd concentrations appear to be mainly controlled by carbonates. PCBs and PBDEs were detected only in sediments and show relatively low concentrations compared to similar lagoon environments. Regarding the sediment quality guidelines, Cd, Cu and PCBs in both lagoons did not exceed any Probable Effect Concentration (PEC). [ABSTRACT FROM AUTHOR]

Assessing implicit learning in the continuous pursuit-tracking task usually concerns a repeated segment of target displacements masked by two random segments, as referred to as Pew's paradigm. Evidence for segment learning in this paradigm is scanty and contrasts with robust sequence learning in discrete tracking tasks. The present study investigates this issue with two experiments in which participants ( N = 56) performed a continuous tracking task. Contrary to Pew's paradigm, participants were presented with a training sequence that was continuously cycled during 14 blocks of practice, but Block 12 in which a transfer sequence was introduced. Results demonstrate sequence learning in several conditions except in the condition that was obviously the most similar to previous studies failing to induce segment learning. Specifically, it is shown here that a target moving too slowly combined with variable time at which target reversal occurs prevents sequence learning. In addition, data from a post-experimental recognition test indicate that sequence learning was associated with explicit perceptual knowledge about the repetitive structure. We propose that learning repetition in a continuous tracking task is conditional on its capacity to (1) allow participants to detect the repeated regularities and (2) restrict feedback-based tracking strategies. [ABSTRACT FROM AUTHOR]

Purpose: Almost 20 nuclear reactors are situated along the Rhône valley, representing Europe's largest concentration of nuclear power plants. The fate of suspended sediments and natural and artificial particle-bound radionuclides in relation to extreme hydrological events was assessed at the lower course of the Rhône River, which provides the main source of water and sediment inputs to the northwestern Mediterranean Sea. Materials and methods: We sampled water at a high frequency over the period 2001-2008 and measured suspended particulate matter (SPM) loads and particle-bound natural and artificial radionuclide concentrations at the SORA observatory station in Arles, France. We monitored various hydrological events (either natural or anthropogenic origin) and characterize their influence on concentrations and fluxes. Results and discussion: The relationship between SPM concentration and the very wide range of water discharges did not differ significantly from previous periods, indicating no significant shift in the average sediment delivery over the last 20 years. Unexpected hydrological events of anthropogenic origin, in particular those associated with flushing of reservoirs that are generally not captured by sampling strategies, were recorded and were shown to transfer significant additional sediment and associated contaminants towards the marine environment. Concentrations of anthropogenic radionuclides associated with sediment (i.e., Cs, Co, Mn, Ag, and Pu isotopes) varied over two to three orders of magnitude during periods of low and moderate flow due to variations in the liquid release from nuclear facilities. Except for Pu isotopes, the concentrations of the various particle-bound radionuclides generally showed a decreasing trend with increasing discharge, revealing the geochemical or anthropogenic background values, and providing a useful flood fingerprint for this large fluvial system before its entry into the marine environment. Conclusions: Our approach produced key data on the level and fate of suspended solids and radionuclide concentrations during flood events occurring in a large river system that could be contaminated by chronic or accidental radioactive releases. These results are of fundamental importance for further interpretations of sediment dynamics at the river mouth. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is a protozoan parasite infecting humans and animals. Wild boars Sus scrofa are a potential source of human infection and an appropriate biological model for analyzing T. gondii dynamics in the environment. Here, we aimed to identify environmental factors explaining the seroprevalence of toxoplasmosis in French wild boar populations. Considering 938 individuals sampled from 377 'communes', overall seroprevalence was 23% (95% confidence interval: [22-24]). Using a Poisson regression, we found that the number of seropositive wild boars detected per 'commune' was positively associated with the presence of European wildcats ( Felis silvestris) and moderate winter temperatures. [ABSTRACT FROM AUTHOR]

Gene therapy of inherited hepatic disease relies on sustained expression of the therapeutic transgene. In many instances, such expression will require immune tolerization to the non-self therapeutic transgene product. We previously demonstrated that a cytotoxic immune response eliminated hepatocytes after in vivo transduction using recombinant retroviral vectors. In the present study we investigated whether prior gene transfer to the retina, which is suspected to induce immune tolerance, could alleviate the immune response occurring after retrovirus mediated gene transfer to the liver. Retinal cells were transduced using adeno-associated viral vectors harbouring a β-galactosidase transgene. Sixty days later, regenerating hepatocytes were transduced after partial hepatectomy using a recombinant retrovirus carrying the transgene. Three weeks later, anti β-galactosidase antibodies were present in all animals. Elimination of the transduced hepatocytes eventually occurred in all animals by 2 months after liver gene transfer, although sustained β-galactosidase expression was still present in the retina in 66% of the animals. We conclude that although the retina behaves as an immunoprivileged site, gene expression in the subretinal space is not sufficient to induce immune tolerance to a transgene product expressed in the liver. [ABSTRACT FROM AUTHOR]

Highly efficient retroviral-mediated gene transfer into hepatocytes in vivo has been previously reported in rats, but some reports described transient expression of the transgene that may be related to induction of an immune response against the transgene product. To devise a surgical approach to circumvent this drawback, two-thirds partial hepatectomy was performed in Wistar male rats to induce the hepatocyte division required to achieve retrovirus integration. Delivery of amphotrophic retroviral vectors (RVV) encoding Escherichia coli β-galactosidase was performed 24 h after partial hepatectomy. In a first group (n = 11), gene delivery was performed by peripheral injection of 2 ml retrovirus-containing medium. For the second group (n = 11), asanguineous perfusion of the regenerating liver after complete vascular exclusion was carried out with 20 ml viral solution. Liver biopsies were performed sequentially in each group. In the first group, β-galactosidase was expressed at day 7 in 7 ± 6.3% of hepatocytes and the labeled hepatocytes had disappeared in less than 4 weeks. Polymerase chain reaction experiments demonstrated the elimination of the transduced cells and the appearance of antibodies against β-galactosidase. Of the 11 rats in the second group, 8 were still able to express β-galactosidase more than 6 weeks after asanguineous perfusion with no detectable antibody response. Asanguineous perfusion of the regenerating liver with RVV after complete vascular exclusion enabled long-term expression in rats and avoided the immune response present after peripheral delivery in most animals. These results suggest that the immune reaction is secondary to viral infection of antigen presenting cells. Asanguineous perfusion could thus be a way to perform gene therapy for inherited liver diseases without immunosupressive therapy. [ABSTRACT FROM AUTHOR]

Toxoplasma gondii is an intracellular, obligate protozoan parasite that actively invades host cells. Phospholipases A2 (PLA2) are widely distributed enzymes that exist in many isoforms [secretory (sPLA2), cytosolic (cPLA2)] in monocytic and other human cells (pancreatic, kidney, etc) and also in parasites. We examined the effects of inhibitors of sPLA2 type II and cPLA2 on the invasion of human monocytic cells (THP1) by T. gondii (RH strain). We also measured sPLA2 type II and cPLA2 enzyme activities and their modulation by interferon γ (IFN γ) in extracts of host cells and parasite. Inhibition of both parasite and THP1 sPLA2 type II, and of parasite cPLA2 reduced the number of infected cells. Enzyme assays and immunoblot analyses demonstrated T. gondii sPLA2 type II and cPLA2 activities and indicated that T. gondii increased the activity of THP1 sPLA2 type II. Incubation with IFN γ (1,000 units/ml) for 20 h reduced the activities of sPLA2 and cPLA2 in infected and non-infected cells. Thus, IFN γ blocks the activities of both THP1 and parasite sPLA2 and cPLA2 in membrane fractions, resulting in protection against active invasion by T. gondii. [ABSTRACT FROM AUTHOR]

Minisatellites are tandemly repeated DNA sequences of 10?100-bp units. Some minisatellite loci are highly unstable in the human germ line, and structural analysis of mutant alleles has suggested that repeat instability results from a recombination-based process. To provide insights into the molecular mechanism of human minisatellite instability, we developed Saccharomyces cerevisiae strains carrying alleles of the most unstable human minisatellite locus, CEB1 (ref. 2). We observed that CEB1 is destabilized in meiosis, resulting in a variety of intra- and inter-allelic gains or losses of repeat units, similar to rearrangements described in humans. Using mutations affecting the initiation of recombination (spo11) or mismatch repair (msh2 pms1), we demonstrate that meiotic destabilization depends on the initiation of homologous recombination at nearby DNA double-strand break (DSBs) sites and involves a 'rearranged heteroduplex' intermediate. Most of the human and yeast data can be explained and unified in the context of DSB repair models. [ABSTRACT FROM AUTHOR]

The GASA gene family previously identified in Arabidopsis belongs to a wide-spread class of genes found in mono- and dicotyledonous plants, all structurally related to the original GA-regulated GAST1 gene from tomato. They encode small peptides (97 to 112 residues) of unknown function sharing a 60 amino acid conserved C-terminal domain comprising twelve conserved cysteine residues which define a pattern not related to other known cysteine-rich motifs. Northern blot hybridization analysis revealed sequential expression of three genes during flowering, silique development and seed germination. GASA4 transcripts were detected in flower buds. GASA1 transcripts markedly accumulated in siliques, about five days after pollination, and correlated with the peak of GA biosynthesis at this stage of silique development. GASA3 transcripts accumulated at the end of the maturation stage of the silique, and transcripts were still present in dry seeds but degraded rapidly during imbibition. In addition, the GASA4 gene was again actively transcribed after germination and this expression was shown to be dependent on the presence of GAs in GA-deficient mutants. Immunoblot analysis confirmed the presence of the GASA4 gene product in flower buds, seedlings and roots. We focused on the GASA4 gene and characterized its expression. The upstream region (-890 to +128) was fused to the GUS reporter gene. GASA4/GUS expression was detected in transgenic Arabidopsis primarily in all meristematic regions, including vegetative, inflorescence and floral meristems, as well as primary and lateral root tips. In a GA-deficient background (ga1–3), GUS activity in the vegetative meristem was detected only in the presence of supplied GA. In root and flower meristems, basal GUS activity was slightly enhanced by exogenous GA. Interestingly, GA strongly inhibit GUS activity in expanding cotyledons and leaves in ga1–3 mutants supplied with exogenous GAs, as well as in the wild type. The GA-dependent meristem-specific expression pattern suggests that the GASA4 protein plays a role in dividing cells rather than in elongating cells. [ABSTRACT FROM AUTHOR]