First screening of Aedes albopictus immunogenic salivary proteins.

Study of the human antibody (Ab) response to Aedes salivary proteins can provide new biomarkers to evaluate human exposure to vector bites. The identification of genus- and/or species-specific proteins is necessary to improve the accuracy of biomarkers. We analysed Aedes albopictus immunogenic salivary proteins by 2D immunoproteomic technology and compared the profiles according to human individual exposure to Ae. albopictus or Ae. aegypti bites. Strong antigenicity to Ae. albopictus salivary proteins was detected in all individuals whatever the nature of Aedes exposure. Amongst these antigenic proteins, 68% are involved in blood feeding, including D7 protein family, adenosine deaminase, serpin and apyrase. This study provides an insight into the repertoire of Ae. albopictus immunogenic salivary proteins for the first time.

Applicability of OECD TG 201, 202, 203 for the aquatic toxicity testing and assessment of 2D Graphene material nanoforms to meet regulatory needs.

Tests using algae and/or cyanobacteria, invertebrates (crustaceans) and fish form the basic elements of an ecotoxicological assessment in a number of regulations, in particular for classification of a substance as hazardous or not to the aquatic environment according to the Globally Harmonised System of Classification and Labelling of Chemicals (GHS-CLP) (GHS, 2022) and the REACH regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals, EC, 2006). Standardised test guidelines (TGs) of the Organisation for Economic Co-operation and Development (OECD) are available to address the regulatory relevant endpoints of growth inhibition in algae and cyanobacteria (TG 201), acute toxicity to invertebrates (TG 202), and acute toxicity in fish (TG 203). Applying these existing OECD TGs for testing two dimensional (2D) graphene nanoforms may require more attention, additional considerations and/or adaptations of the protocols, because graphene materials are often problematic to test due to their unique attributes. In this review a critical analysis of all existing studies and approaches to testing used has been performed in order to comment on the current state of the science on testing and the overall ecotoxicity of 2D graphene materials. Focusing on the specific tests and available guidance's, a complete evaluation of aquatic toxicity testing for hazard classification of 2D graphene materials, as well as the use of alternative tests in an integrated approach to testing and assessment, has been made. This information is essential to ensure future assessments generate meaningful data that will fulfil regulatory requirements for the safe use of this "wonder" material.

Evaluation of meat and bone meal combustion residue as lead immobilizing material for in situ remediation of polluted aqueous solutions and soils: "chemical and ecotoxicological studies".

As a result of bovine spongiform encephalopathy (BSE) crisis, meat and bone meal (MBM) production can no longer be used to feed cattle and must be safely disposed of or transformed. MBM specific incineration remains an alternative that could offer the opportunity to achieve both thermal valorization and solid waste recovery as ashes are calcium phosphate-rich material. The aim of this work is to evaluate ashes efficiency for in situ remediation of lead-contaminated aqueous solutions and soils, and to assess the bioavailability of lead using two biological models, amphibian Xenopus laevis larvae and Nicotiana tabaccum tobacco plant. With the amphibian model, no toxic or genotoxic effects of ashes are observed with concentrations from 0.1 to 5 g of ashes/L. If toxic and genotoxic effects of lead appear at concentration higher than 1 mg Pb/L (1 ppm), addition of only 100 mg of ashes/L neutralizes lead toxicity even with lead concentration up to 10 ppm. Chemical investigations (kinetics and X-ray diffraction (XRD) analysis) reveals that lead is quickly immobilized as pyromorphite [Pb10(PO4)6(OH)2] and lead carbonate dihydrate [PbCO(3).2H2O]. Tobacco experiments are realized on contaminated soils with 50, 100, 2000 and 10000 ppm of lead with and without ashes amendment (35.3g ashes/kg of soil). Tobacco measurements show that plant elongation is bigger in an ashes-amended soil contaminated with 10000 ppm of lead than on the reference soil alone. Tobacco model points out that ashes present two beneficial actions as they do not only neutralize lead toxicity but also act as a fertilizer.

Management of child MDR-TB contacts across countries in the WHO European Region: a survey of current practice.

The World Health Organization European Region has one of the highest rates of multidrug-resistant tuberculosis (MDR-TB) in the world, resulting in many vulnerable children being exposed each year. Evidence for preventive therapy following MDR-TB exposure is limited and current guidance is conflicting. An internet-based survey was performed to determine clinical practice in this region. Seventy-two clinicians from 25 countries participated. Practices related to screening and decision-making were highly variable. Just over half provided preventive therapy for children exposed to MDR-TB; the only characteristic associated with provision was practice within the European Union (adjusted OR 4.07, 95%CI 1.33-12.5).

Genotoxic and stress inductive potential of cadmium in Xenopus laevis larvae.

The present investigation evaluates the toxic potential of Cd in larvae of the frog Xenopus laevis after 12 days of exposure to environmentally relevant contamination levels, close to those measured in the river Lot (France). Several genotoxic and detoxification mechanisms were analyzed in the larvae: clastogenic and/or aneugenic effects in the circulating blood by micronucleus (MN) induction, metallothionein (MT) production in whole larvae, gene analyses and Cd content in the liver and also in the whole larvae. The results show: (i) micronucleus induction at environmental levels of Cd contamination (2, 10, 30 microgL(-1)); (ii) an increased and concentration-dependent quantity of MT in the whole organism after contamination with 10 and 30 microgCdL(-1) (a three- and six-fold increase, respectively) although no significant difference was observed after contamination with 2 microgCdL(-1); (iii) Cd uptake by the whole organism and by the liver as a response to Cd exposure conditions; (4) up-regulation of the genes involved in detoxification processes and response to oxidative stress, while genes involved in DNA repair and apoptosis were repressed. The results confirm the relevance of the amphibian model and highlight the complementarity between a marker of genotoxicity, MT production, bioaccumulation and genetic analysis in the evaluation of the ecotoxicological impact.

Biomonitoring of the genotoxic potential of aqueous extracts of soils and bottom ash resulting from municipal solid waste incineration, using the comet and micronucleus tests on amphibian (Xenopus laevis) larvae and bacterial assays (Mutatox and Ames tests).

The management of contaminated soils and wastes is a matter of considerable human concern. The present study evaluates the genotoxic potential of aqueous extracts of two soils (leachates) and of bottom ash resulting from municipal solid waste incineration (MSWIBA percolate), using amphibian larvae (Xenopus laevis). Soil A was contaminated by residues of solvents and metals and Soil B by polycyclic aromatic hydrocarbons and metals. MSWIBA was predominantly contaminated by metals. Two genotoxic endpoints were analysed in circulating erythrocytes taken from larvae: clastogenic and/or aneugenic effects (micronucleus induction) after 12 days of exposure and DNA-strand-breaking potency (comet assay) after 1 and 12 days of exposure. In addition, in vitro bacterial assays (Mutatox and Ames tests) were carried out and the results were compared with those of the amphibian test. Physicochemical analyses were also taken into account. Results obtained with the amphibians established the genotoxicity of the aqueous extracts and the comet assay revealed that they were genotoxic from the first day of exposure. The latter test could thus be considered as a genotoxicity-screening tool. Although genotoxicity persisted after 12 days' exposure, DNA damage decreased overall between days 1 and 12 in the MSWIBA percolate, in contrast to the soil leachates. Bacterial tests detected genotoxicity only for the leachate of soil A (Mutatox). The results confirm the ecotoxicological relevance of the amphibian model and underscore the importance of bioassays, as a complement to physico-chemical data, for risk evaluation.

Biomonitoring of the genotoxic potential of draining water from dredged sediments, using the comet and micronucleus tests on amphibian (Xenopus laevis) larvae and bacterial assays (Mutatox and Ames tests).

Management of contaminated dredged sediments is a matter of great human concern. The present investigation evaluates the genotoxic potential of aqueous extracts of five sediments from French channels (draining water from dredged sediments), using larvae of the frog Xenopus laevis. Two genotoxic endpoints were analyzed in larvae: clastogenic and/or aneugenic effects (micronucleus induction after 12 d of exposure) and DNA-strand breaking potency (comet assay after 1 and 12 d of exposure) in the circulating blood. Additionally, in vitro bacterial assays (Microtox and Ames tests) were carried out and the results were compared with those obtained with larvae. Physicochemical analyses were also taken into account. Analytical analyses highlighted in the five draining waters a heavy load of contaminants such as metals and hydrocarbons. The results obtained with the micronucleus test established the genotoxicity of three draining waters. The comet assay showed that all 5 draining waters were genotoxic after 1 d of exposure. Although 3 of them were still genotoxic after 12 d of exposure, DNA damage globally decreased between d 1 and 12. The comet assay can be considered as a genotoxicity-screening tool. Data indicate that both tests should be used in conjunction in Xenopus. Bacterial tests (Ames) revealed genotoxicity for only one draining water. The results confirm the relevance of the amphibian model and the need to resort to bioassays in vivo such as the Xenopus micronucleus and comet assays for evaluation of the ecotoxicological impact, an essential complement to the physicochemical data.

Recovery capabilities of Xenopus laevis after exposure to Cadmium and Zinc.

The present investigation evaluates the recovery capabilities of Xenopus laevis following 12days of exposure to 30µg CdL(-1) and 1000µg ZnL(-1) alone or mixed, followed by a depuration phase in laboratory conditions. Focused endpoints, which were investigated at different times of depuration, are bioaccumulation of Cd and Zn, micronucleus induction, quantification of metallothioneins (MTs), and expression of genes involved in metal toxicity mechanisms. The results show that at the end of the contamination phase, there was higher metal bioaccumulation capability and MT synthesis in remaining tissues than in the liver. An increased expression of genes involved in detoxification and oxidative stress mechanisms was observed, suggesting an additive effect of both metals and a higher Zn regulation in the liver. During the depuration phase, the results show the recovery capability of Xenopus from 7days of depuration related to metamorphosis processes, which were observed at the end of the experiment. The results confirm the relevance of the amphibian model and the complementarities between a marker of genotoxicity, MT production, bioaccumulation and transcriptional analysis in the evaluation of the ecotoxicological impact. The results also highlight the reversible effects of Cd and Zn toxicity.

Early cellular immune response to a new candidate mycobacterial vaccine antigen in childhood tuberculosis.

The search for novel vaccines against tuberculosis (TB) would benefit from in-depths knowledge of the human immune responses to Mycobacterium tuberculosis (Mtb) infection. Here, we characterised in a low TB incidence country, the immune responses to a new candidate vaccine antigen against TB, the heparin-binding haemagglutinin (HBHA), in young children in contact with an active TB case (aTB). Children with no history of BCG vaccination were compared to those vaccinated at birth to compare the initial immune responses to HBHA with secondary immune responses. Fifty-eight children with aTB and 76 with latent TB infection (LTBI) were included and they were compared to 90 non-infected children. Whereas Mtb-infected children globally secreted more interferon-gamma (IFN-γ) in response to HBHA compared to the non-infected children, these IFN-γ concentrations were higher in previously BCG-vaccinated compared to non-vaccinated children. The IFN-γ concentrations were similar in LTBI and aTB children, but appeared to differ qualitatively. Whereas the IFN-γ secretion induced by native methylated and recombinant non-methylated HBHA were well correlated for aTB, this was not the case for LTBI children. Thus, Mtb-infected young children develop IFN-γ responses to HBHA that are enhanced by prior BCG vaccination, indicating BCG-induced priming, thereby supporting a prime-boost strategy for HBHA-based vaccines. The qualitative differences between aTB and LTBI in their HBHA-induced IFN-γ responses may perhaps be exploited for diagnostic purposes.

Urinary tract lesions due to Schistosoma haematobium infection assessed by ultrasonography in a community based study in Niger.

The comparative prevalences of urinary tract lesions in 2 villages where urinary schistosomiasis was endemic and in a control village free from infection were assessed by ultrasonography. Of the 822 residents greater than 4 years of age in the first village (Sébéri) where the prevalence of infection was 57%, 279 were examined by ultrasonography. The prevalence of bladder lesions was 71% in those 5-14 years of age, 57% among adult men, and 24% among women in this endemic village, compared to 10%, 16%, and 6%, respectively, in the control village. Renal lesions were infrequent among adults and there was no significant difference in the rates between Sébéri and the control village. Among children, moderate hydronephrosis was absent in the control village, but was observed in 19% of the boys 5-14 years of age and 2% of the girls 5-14 years of age in Sébéri. Sixty schoolchildren of the second endemic village with urinary egg counts greater than or equal to 100 eggs/10 ml of urine were examined by ultrasonography. The overall prevalence and the severity of bladder lesions in the 2 endemic villages were significantly related to the urinary egg count.

Pattern of cercarial emergence of Schistosoma curassoni from Niger and comparison with three sympatric species of schistosomes.

The emergence pattern of Schistosoma curassoni cercariae from Bulinus umbilicatus, whose adult worms parasitize bovine, caprine, and ovine ungulates in Niger, is of a circadian type with a mean emission time at 0855 hr +/- 1 hr 6 min, characteristic of the schistosome species parasitizing domestic or wild cattle. The comparison of this cercarial emergence pattern with those of the other 3 sympatric species of schistosomes (Schistosoma haematobium, Schistosoma bovis, and Schistosoma mansoni) shows a significant difference between the chronobiology of the cercariae infective for human and those infective for bovine hosts. This difference may improve epidemiological surveys based on snail prevalences by allowing the distinction between bulinids infected with human and bovine parasites.

[Urinary schistosomiasis in the Saharan mountain plateau of Air (Republic of Niger)]. / La schistosomose urinaire dans le massif Saharien de l'Aïr (République du Niger).

In two villages of the Aïr (Republic of Niger) the authors have found a Schistosoma haematobium overall prevalence of 24.1% at Timia and 43.5% at El Meki. At El Meki, the distribution of prevalences by age group accords to that which is usually found. The maximum is found in the 5-14 years age group and highest in men than in women. At Timia, the prevalence among young pupils is low, this seems to be due to the application of sanitary education measures. At El Meki, Bulinus truncatus rohlfsi, present in a permanent pool ("guelta") is the intermediate host of schistosomes. The role of this snail in the transmission of urinary schistosomiasis at Timia has not been demonstrated. The role of Bulinus senegalensis, found in both villages has yet to be proved.

[Chemical labyrinthectomy: results and applications]. / Labyrinthectomie chimique. Résultats et intérêt.

GOAL OF THE STUDY: Unilateral Menière's disease can be treated by chemical labyrinthectomy. The goal of this work was to report our clinical experience with chemical labyrinthectomy, and to discuss the respective value of labyrinthectomy and of vestibular neurotomy for treating unilateral Menière's disease. METHODS: Twelve patients underwent chemical labyrinthectomy using middle ear gentamicin infusion. Before treatment, patients had a pure tone audiogram and a vestibular caloric testing. After treatment, patients had a clinical assessment at 1 and 6 months after treatment (pure-tone audiogram, vestibular caloric testing), and answered a questionnaire at 1 and 2 years following the treatment (number of vertigo attacks, ataxia, tinnitus, subjective assessment of the method by the patient). RESULTS: At two years post-treatment, the vertigo cure rate was 91.6% (ABC using AAOO criteria), vestibular function was abolished in 70% of cases, ataxia was reported in 42% of patients, 16.6% of patients had hearing deterioration above 20 dB HL (C following AAOO criteria), tinnitus was decreased in 50% of cases. Of 12 patients, 8 were satisfied. CONCLUSION: Chemical labyrinthectomy cures vertigo in Menière's disease, with similar cure rate than vestibular neurotomy. Minor complications can occur with chemical labyrinthectomy. This method should be used in more patients.

[Chemotherapy trial in the battle against Schistosoma haematobium in an irrigated sahelian zone in Niger]. / Essai de lutte par chimiothérapie contre Schistosoma haematobium en zone irriguée Sahélienne au Niger.

This study of S. haematobium infection in communities associated with irrigated schemes shows that prevalence rates are unusually high in adults, especially in men; and distribution disease is probably associated with at least the following three factors: (i) distance of the place of residence from the main transmission sites (ii) the dynamics of transmission in the waterbody and (iii) the human/water contact and contamination patterns. During this chemotherapy trial, at the first survey, only a little more than half (57.47%) of the people recorded in the census was present. Five visits of the survey team were necessary to obtain a compliance rate of 80.51% of the entire population. The indifference of the local people to seek diagnosis and treatment increased with succeeding surveys. It is only, during a subsequent treatment survey, carried out during the season of low agricultural activity and following an official written convocation, that a compliance rate similar to that of the first survey was recorded. If treatment is not given immediately after diagnosis as many as a fifth of positive cases do not appear for treatment. Oltipraz and praziquantel were administered. Their effectiveness could not be truly compared as there was a time lag of six months separating the administration of the treatments. However, based on the results of this trial both drugs gave good results especially in egg output intensity. But, a decrease of this parameter was also observed in non treated people. Seasonal variations of egg output or decrease of transmission could be involved.

[Epidemiological study of a focus of Schistosoma mansoni in Bana (Niger)]. / Etude épidémiologique du foyer à Schistosoma mansoni de Bana (Niger).

An epidemiological survey was made in 4 villages of the recently discovered Schistosoma mansoni focus of Bana (Niger). The total prevalence of intestinal schistosomiasis is 15%. The highest prevalences are noted in the age-group from 20 to 38 years old. The mean egg load is moderate: 11.3 eggs/g of stools. Several hypothesis are discussed to explain the low endemicity of this focus.

[Comparative efficacy of oltipraz (1 dose, 30 mg/kg) and the combination of niridazole (25 mg/kg) and metrifonate (10 mg/kg) against S. haematobium]. / Efficacité comparée de l'oltipraz (1 dose, 30 mg/kg) et de l'association niridazole (25 mg/kg) - métrifonate (10 mg/kg) contre S. haematobium.

PUGH (1978) and TEEDSALE et al. (1980) showed that an associated single dose of metrifonate (12.5 mg/kg) plus niridazole (25 mg/kg) gave good results on Schistosoma haematobium: the egg-reduction percentage ranged between 84.7 and 91.2. In Niger, we compared the effects of this medication to oltipraz in a single dose (30 mg/kg). We selected a dosage of 10 mg/kg of metrifonate and 25 mg/kg of niridazole. This trial was carried out during the minimal transmission period. --109 adults (greater than 15 years) received oltipraz and 159 this combined treatment. They were examined twice: 11/2 month and 6 months after treatment. At the first control, the cure rate was 26.7% for oltipraz and 23.3% for the combined treatment, the egg-reduction was respectively 77.1% and 41.3%. Six months after treatment, the cure rate was 43.5% for oltipraz and 27.7% for the combined treatment and the egg-reduction was 66.5% and 2.0% respectively. Following these results, the authors recommend against the combined treatment in Niger. They note that if, in some particular conditions, this medication can give good results (PUGH, 1978, TEESDALE et al., 1980) it is however necessary to include its test in future control projects. Also, they note the weak result obtained with oltipraz; but, in this case, the heavy endemic level and high egg-loads might explain it, as well as the fact that the 30 mg/kg dosage was probably insufficient.

[Use of urine collectors for infants from 0 to 4 years of age in a mass survey of urinary schistosomiasis in Niger]. / Utilisation des collecteurs urinaires chez les enfants de 0 à 4 ans en enquête de masse sur la schistosomose urinaire au Niger.

A simple method, using urine collectors, was devised to obtain sufficient and reliable samples of urine from infants (0-4 years old) for the quantitative diagnosis of urinary schistosomiasis. The use of urine collectors is readily accepted by rural populations and it avoids possible interchange between young children. Urine collection and examination from as many as 100 infants can be undertaken daily by a small, well-trained survey team. Our present observations on S. haematobium among infants in Niger show surprisingly high (14.06 per cent) prevalence rates and suggest that this age group may play a considerable role in the transmission of the infection in some endemic foci.

[Course of urinary schistosomiasis over 3 consecutive years after treatment with metrifonate in a dry savanna village in Upper Volta]. / Evolution sur trois années consécutives de la schistosomose urinaire après traitement au metrifonate dans un village de savane seche de Haute-Volta.

In a dry savanna village in Upper-Volta, after mass treatment with metrifonate (four doses of 7,5 mg/kg at three weeks intervals) checking of the population was carried out for the three following years. In children and adolescents, results show a progressive decline in the cure rate (69.0% one year after treatment, 38.1% three years after treatment) and in egg-output reduction (69.9% one year after treatment, 75.4% three years after treatment). In adults, these two parameters still remain high three years after treatment (90.0% for cure rate and 87.3% for egg-output reduction). The authors point out that in a dry savanna village with a sedentary population and a transmission limited to a small collection of water, chemotherapy even employed alone is an appreciable control method to relieve populations.

Long-incubation-time gamma interferon release assays in response to purified protein derivative, ESAT-6, and/or CFP-10 for the diagnosis of Mycobacterium tuberculosis infection in children.

The diagnosis of childhood active tuberculosis (aTB) and latent Mycobacterium tuberculosis (M. tuberculosis) infection (LTBI) remains a challenge, and the replacement of tuberculin skin tests (TST) with commercialized gamma interferon (IFN-γ) release assays (IGRA) is not currently recommended. Two hundred sixty-six children between 1 month and 15 years of age, 214 of whom were at risk of recent M. tuberculosis infection and 51 who were included as controls, were prospectively enrolled in our study. According to the results of a clinical evaluation, TST, chest X ray, and microbiological assessment, each children was classified as noninfected, having LTBI, or having aTB. Long-incubation-time purified protein derivative (PPD), ESAT-6, and CFP-10 IGRA were performed and evaluated for their accuracy in correctly classifying the children. Whereas both TST and PPD IGRA were suboptimal for detecting aTB, combining the CFP-10 IGRA with a TST or with a PPD IGRA allowed us to detect all the children with aTB with a specificity of 96% for children who were positive for the CFP-10 IGRA. Moreover, the combination of the CFP-10 IGRA and PPD IGRA detected 96% of children who were eventually classified as having LTBI, but a strong IFN-γ response to CFP-10 (defined as >500 pg/ml) was highly suggestive of aTB, at least among the children who were <3 years old. The use of long-incubation-time CFP-10 IGRA and PPD IGRA should help clinicians to quickly identify aTB or LTBI in young children.