Risk factors for hepatitis C virus infection among blood donors in southern Brazil: a case-control study

BACKGROUND: In Brazil, it is estimated that between 2.5 and 4.9% of the general population present anti-hepatitis C virus (HCV) antibodies, which corresponds to as many as 3.9 to 7.6 million chronic carriers. Chronic liver disease is associated with HCV infection in 20% to 58% of the Brazilian patients. The objective of this case-control study was to investigate the risk factors for presence of anti-HCV antibody in blood donors in southern Brazil. METHODS: One hundred and seventy eight blood donors with two positive ELISA results for anti-HCV were cases, and 356 controls tested negative. A standardized questionnaire was used to collect data concerning demographic and socioeconomic aspects, history of previous hepatitis infection, social and sexual behaviors, and number of donations. Variables were grouped into sets of hierarchical categories. Cases and controls were compared using logistic regression, odds ratios, and 95% confidence intervals. The statistical significance of the associations was assessed through likelihood ratio tests based on a P value < 0.05. RESULTS: The prevalence of anti-HCV among blood donors was 1.1%. Most of the donors were white and males. In the multivariate analysis, independent predictors of anti-HCV positivity were: intravenous drug use, blood transfusion >10 years earlier, having had two to four sexually transmitted diseases, incarceration, tattooing, sex with a hepatitis B or C virus carrier or with intravenous drug users. CONCLUSION: Intravenous drug use, blood transfusion, and tattooing were the main risk factors for anti-HCV positivity among blood donors from southern Brazil, but sexual HCV transmission should also be considered

Decoding the microstructural properties of white matter using realistic models

Data Sharing collection allowing to reproduce the results in the publication:Hédouin, R., Metere, R., Chan, K.-S., Licht, C., Mollink, J., van Walsum, A.-M.C., Marques, J.P., Decoding the microstructural properties of white matter using realistic models, (2021) NeuroImage, 237, art. no. 118138, DOI: 10.1016/j.neuroimage.2021.118138Highlights- A pipeline to generate realistic white models of arbitrary fiber volume fraction and g-ratio is provided.- Code to simulated the gradient echo signal from segmented 2D and 3D models of white matter, which takes into account the interaction of the static magnetic field with the anisotropic susceptibility of the myelin phospholipids using a new compartmentalization model within the myelin sheath.- Code for training and using Deep Learning Networks that can be used to decode microstructural white matter parameters from the signal of multi-echo multi-orientation data.- Multi-echo gradient data of an ex-vivo Brain sample acquired at 3T with different flip angles and multiple orientations of the sample in respect to the static magnetic field

La microscopie électronique à balayage environnementale équipée en micro-analyse X : son utilisation en pathologie osseuse humaine. Perspectives et limites

Dans une étude récemment publiée, nous avons montré l'intérêt de l'utilisation des techniques physiques telles que la diffraction des rayons X, la fluorescence X et la microscopie électronique à balayage environnementale (MEBE) équipée en microanalyse X dans l'identification de la tuberculose ostéo-articulaire sur du matériel ostéo-archéologique. L'objectif de l'étude actuelle est l'application du MEB environnemental dans l'identification de la maladie tuberculeuse dans des os provenant de biopsie. Nous avons étudié d'abord l'effet d'un traitement à la potasse sur le carbonate de calcium, composant dont la présence au sein de la lésion osseuse serait spécifique de la tuberculose. Une attaque dans une solution de potasse KOH 2M à 105 °C pendant 2 heures, a été retenue comme condition de traitement. Le traitement a été appliqué ensuite à un os sain frais pour en apprécier l'efficacité sur le collagène dont la présence pourrait gêner la lecture du carbonate de calcium au MEB. Enfin, le même traitement est appliqué à un os tuberculeux. Nous avons montré une conservation de la structure apatitique de l'os après traitement et une destruction partielle du collagène. Dans l'os tuberculeux, nous avons mis en évidence la conservation partielle du dépôt de carbonate de calcium dont une partie n'a pas résisté au traitement. Ces résultats permettent de définir les termes d'une nouvelle méthode de traitement à la fois plus agressive pour le collagène et moins agressive pour le carbonate de calcium et confirment, par la qualité des images et la précision des analyses, les potentialités des applications du MEB environnemental dans la recherche médicale.In a recently published study, we have shown the utility of X-ray diffraction, X-ray fluorescence and environmental SEM equipped with micro-analysis in the identification of bone tuberculosis from osteo-archaeological origin. The goal of the present study is the application of environmental SEM in the identification of bone tuberculosis from bone harvested at autopsy. First we studied the effects of potash on calcie, the presence of which signals tuberculosis. The condition under which the calcite remains practically unaffected was KOH 2M at 105° C for two hours. The treatment was applied to a fresh bone sample in order to know the effect on the bone collagen, so that no overlap occurred between the calcium carbonate and the collagen of bone. Finally the same treatment was applied to a bone from a known tuberculous sample. We have noted no destruction of the apatitic structure of the bone with only partial destruction of the collagen. For the tuberculous bone, we have shown the partial conservation of the calcium carbonate deposit. These results allow us to define a new treatment method, which is at the same time more destructive to the collagen and less destructive for the calcium carbonate component. This paper presents a new application of a nineteenth century method of extracting collagen. These results confirm, by the fine quality of the environmental SEM images and the precision analyses, the great potential of environmental SEM in medical research

Minimising the risk posed by TiO2 nanomaterials used in sunscreen throughout the entire product lifecycle

Sunscreens are of emerging concern regarding both human and environmental health. While TiO2 nanoparticles used as UV-blockers may offer a safer alternative to organic filters, their fate and impact and resulting regulation are still under consideration, largely related to the potential risk of nanotechnology-based products. After leaving the skin either through bathing or cleaning, the TiO2 nanomaterials contained in the sunscreen can be released into rivers, lakes, sea shores, and/or sewage treatment plants. Their fate and impact in these different systems is largely determined by the surface properties, i.e. the coating type and lifetime. This project aims to develop the eco-design of sunscreens through the minimization of risks associated with nanomaterials incorporated into the formulation. All stages of the cream life cycle must be considered in this light, from its manufacture to its end of life, through its use by the consumer and its impact on the exposed environment. By considering each development stage of the sunscreen, from the choice of UV-blocker and its integration into a cosmetic formulation, to the knowledge of the risk involved in this choice all along the product lifecycle, an eco-design approach can be achieved and risk can be minimized. The present work combines industrial companies specialising in cosmetic formulation with academic research experts in the fields of exposure, toxicity and lifecycle assessment. Sunscreen fabrication, risk for the consumer by dermal exposure, risk for the direct aquatic environment and risk related to the end of life of the product are as many key steps of the sunscreen lifecycle that were investigated in this project

Contrasting patterns of mortality in Polynesian coral reefs following the third global coral bleaching event in 2016

In 2016, many tropical corals worldwide were exposed to anomalously high temperatures due to one of the strongest El Nino events ever recorded. Bleaching impacts were reported on 23 islands within three archipelagos of French Polynesia (Tuamotu, Society and Marquesas archipelagos). A detailed study on the effects of elevated temperatures on corals was performed on five islands (Mo'orea, Makemo, Hikueru, Marutea and Katiu) and revealed contrasting patterns of coral bleaching responses between Mo'orea (Society Archipelago) and the four islands of the Tuamotu Archipelago. While some reefs from the Tuamotu lost more than half of their coral cover, in Mo'orea, less than 1% mortality was recorded 6 months after bleaching. During the 2016 bleaching event, certain reefs at 12 m depth in the outer reef habitats were not exposed to sufficiently long high-temperature periods (heat stress not exceeding 1.1 degrees C weeks in Mo'orea) to cause large-scale bleaching-related coral mortality. In contrast, other reefs in the Tuamotu Archipelago had DHW reaching up to 9.2 degrees C weeks and experienced severe mortality (up to 71%). Our study showed how differential heat stress exposure across reefs of French Polynesia led to different impacts on corals. Until now, Mo'orea reefs have been spared abnormally high temperatures leading to mortality and should be considered an important source of larvae to help maintain reefs on the surrounding islands

Cleft lip/palate and CDH1/E‐cadherin mutations in families with hereditary diffuse gastric cancer

We report the association of CDH1/E‐cadherin mutations with cleft lip, with or without cleft palate (CLP), in two families with hereditary diffuse gastric cancer (HDGC). In each family, the CDH1 mutation was a splicing mutation generating aberrant transcripts with an in‐frame deletion, removing the extracellular cadherin repeat domains involved in cell‐cell adhesion. Such transcripts might encode mutant proteins with trans‐dominant negative effects. We found that CDH1 is highly expressed at 4 and 5 weeks in the frontonasal prominence, and at 6 weeks in the lateral and medial nasal prominences of human embryos, and is therefore expressed during the critical stages of lip and palate development. These findings suggest that alteration of the E‐cadherin pathway can contribute to human clefting