A new perspective of molecular diffusion by nuclear magnetic resonance.

The diffusion-weighted NMR signal acquired using Pulse Field Gradient (PFG) techniques, allows for extrapolating microstructural information from porous materials and biological tissues. In recent years there has been a multiplication of diffusion models expressed by parametric functions to fit the experimental data. However, clear-cut criteria for the model selection are lacking. In this paper, we develop a theoretical framework for the interpretation of NMR attenuation signals in the case of Gaussian systems with stationary increments. The full expression of the Stejskal-Tanner formula for normal diffusing systems is devised, together with its extension to the domain of anomalous diffusion. The range of applicability of the relevant parametric functions to fit the PFG data can be fully determined by means of appropriate checks to ascertain the correctness of the fit. Furthermore, the exact expression for diffusion weighted NMR signals pertaining to Brownian yet non-Gaussian processes is also derived, accompanied by the proper check to establish its contextual relevance. The analysis provided is particularly useful in the context of medical MRI and clinical practise where the hardware limitations do not allow the use of narrow pulse gradients.

Evaluation of Disability Progression in Multiple Sclerosis via Magnetic-Resonance-Based Deep Learning Techniques.

Short-term disability progression was predicted from a baseline evaluation in patients with multiple sclerosis (MS) using their three-dimensional T1-weighted (3DT1) magnetic resonance images (MRI). One-hundred-and-eighty-one subjects diagnosed with MS underwent 3T-MRI and were followed up for two to six years at two sites, with disability progression defined according to the expanded-disability-status-scale (EDSS) increment at the follow-up. The patients' 3DT1 images were bias-corrected, brain-extracted, registered onto MNI space, and divided into slices along coronal, sagittal, and axial projections. Deep learning image classification models were applied on slices and devised as ResNet50 fine-tuned adaptations at first on a large independent dataset and secondly on the study sample. The final classifiers' performance was evaluated via the area under the curve (AUC) of the false versus true positive diagram. Each model was also tested against its null model, obtained by reshuffling patients' labels in the training set. Informative areas were found by intersecting slices corresponding to models fulfilling the disability progression prediction criteria. At follow-up, 34% of patients had disability progression. Five coronal and five sagittal slices had one classifier surviving the AUC evaluation and null test and predicted disability progression (AUC > 0.72 and AUC > 0.81, respectively). Likewise, fifteen combinations of classifiers and axial slices predicted disability progression in patients (AUC > 0.69). Informative areas were the frontal areas, mainly within the grey matter. Briefly, 3DT1 images may give hints on disability progression in MS patients, exploiting the information hidden in the MRI of specific areas of the brain.

Factors associated with anaemia among preschool- age children in underprivileged neighbourhoods in Antananarivo, Madagascar.

BACKGROUND: Anaemia occurs in children when the haemoglobin level in the blood is less than the normal (11 g/dL), the consequence is the decrease of oxygen quantity in the tissues. It is a prevalent public health problem in many low-income countries, including Madagascar, and data on risk factors are lacking. We used existing data collected within the pathophysiology of environmental enteric dysfunction (EED) in Madagascar and the Central African Republic project (AFRIBIOTA project) conducted in underprivileged neighbourhoods of Antananarivo to investigate the factors associated with anaemia in children 24 to 59 months of age. METHODS: Children included in the AFRIBIOTA project in Antananarivo for whom data on haemoglobin and ferritin concentrations were available were included in the study. Logistic regression modelling was performed to identify factors associated with anaemia. RESULTS: Of the 414 children included in this data analysis, 24.4% were found to suffer from anaemia. We found that older children (adjusted OR: 0.95; 95% CI: 0.93-0.98) were less likely to have anaemia. Those with iron deficiency (adjusted OR: 6.1; 95% CI: 3.4-11.1) and those with a high level of faecal calprotectin (adjusted OR: 2.5; 95% CI: 1.4-4.4) were more likely to have anaemia than controls. CONCLUSIONS: To reduce anaemia in the children in this underprivileged area, more emphasis should be given to national strategies that improve children's dietary quality and micronutrient intake. Furthermore, existing measures should be broadened to include measures to reduce infectious disease burden.

ABC Epatite Web App: raising health awareness in a mobile world.

BACKGROUND: This paper presents the case study of a health campaign for mobile devices launched in Italy in 2019 aimed at raising viral hepatitis awareness. The research project "ABC epatite. Sviluppo di una app per la prevenzione delle epatiti virali e per la consapevolezza dei comportamenti a rischio", winner of the 2018 Digital Health Program of Gilead Italia, was carried out by the Italian National Research Council. METHODS: The project entailed the development of a free Italian language Progressive Web App (PWA) providing current and scientifically validated information on viral hepatitis (A, B and C). RESULTS: A mobile first PWA health awareness app was implemented (https://epatite.web.app) together with an Android app version. Diversified landing pages cater to two target audiences: general public and schools. An initial campaign was directed toward engaging schools in nine Italian regions. CONCLUSIONS: Preliminary results based on the campaign directed toward Italian schools in just under half of its regions have shown promise on the feasibility of reaching large audiences and encouraging engagement on viral hepatitis prevention. A mobile first approach to health communication is a cost-effective way to help reaching the goal of eradicating viral hepatitis by reducing infections and deaths.

Factors Associated with Stunted Growth in Children Under Five Years in Antananarivo, Madagascar and Bangui, Central African Republic.

OBJECTIVES: With a fourth of all under-five children affected, stunting remains one of the biggest health challenges worldwide. Even though the main underlying factors are known, the exact pathways to stunting varying in affected regions, and interventions thus need to be tailored to the local contexts. This study aimed assessing and comparing factors associated with stunting in two understudied sub-Saharan urban contexts with some of the highest stunting prevalence globally: Bangui, Central African Republic (~ 36%) and Antananarivo, Madagascar (42%). METHODS: We performed a case-control study on 175 + 194 stunted and 237 + 230 non-stunted control children aged 2-5 years and matched for age, gender and district of residency. Factors associated with stunting were identified using a standardized, paper questionnaire delivered by trained interviewers. Statistical analysis was done using logistic regression modelling. RESULTS: In both sites, formal maternal education lowered the risk of being stunted and restricted access to soap, suffering of anaemia and low birth weight were associated with higher risk of stunting. Short maternal stature, household head different from parents, diarrhoea and coughing were associated with an increased risk and continuing breastfeeding was associated with a lower risk of stunting in Antananarivo. Previous severe undernutrition and dermatitis/ fungal skin infections were associated with higher and changes in diet during pregnancy with lower risk of stunting in Bangui. CONCLUSIONS: Our results suggest maternal education, antenatal care, iron supplementation and simple WASH interventions such as using soap and infection control as general and breastfeeding (Antananarivo) or better nutrition (Bangui) as area-specified interventions.

Two new cases of pediatric tumoral calcinosis.

Tumoral calcinosis (TC) is a rare benign pathology, particularly in pediatrics. It is difficult to diagnose with its pathophysiology poorly understood. We report two pediatric cases of TC having benefited from radiological assessments and surgical excision. Final diagnosis was made by pathological examination. For the two cases, no sign of recurrence was noted ~30 months of follow-up.

Identifying the etiology and pathophysiology underlying stunting and environmental enteropathy: study protocol of the AFRIBIOTA project.

BACKGROUND: Globally one out of four children under 5 years is affected by linear growth delay (stunting). This syndrome has severe long-term sequelae including increased risk of illness and mortality and delayed psychomotor development. Stunting is a syndrome that is linked to poor nutrition and repeated infections. To date, the treatment of stunted children is challenging as the underlying etiology and pathophysiological mechanisms remain elusive. We hypothesize that pediatric environmental enteropathy (PEE), a chronic inflammation of the small intestine, plays a major role in the pathophysiology of stunting, failure of nutritional interventions and diminished response to oral vaccines, potentially via changes in the composition of the pro- and eukaryotic intestinal communities. The main objective of AFRIBIOTA is to describe the intestinal dysbiosis observed in the context of stunting and to link it to PEE. Secondary objectives include the identification of the broader socio-economic environment and biological and environmental risk factors for stunting and PEE as well as the testing of a set of easy-to-use candidate biomarkers for PEE. We also assess host outcomes including mucosal and systemic immunity and psychomotor development. This article describes the rationale and study protocol of the AFRIBIOTA project. METHODS: AFRIBIOTA is a case-control study for stunting recruiting children in Bangui, Central African Republic and in Antananarivo, Madagascar. In each country, 460 children aged 2-5 years with no overt signs of gastrointestinal disease are recruited (260 with no growth delay, 100 moderately stunted and 100 severely stunted). We compare the intestinal microbiota composition (gastric and small intestinal aspirates; feces), the mucosal and systemic immune status and the psychomotor development of children with stunting and/or PEE compared to non-stunted controls. We also perform anthropological and epidemiological investigations of the children's broader living conditions and assess risk factors using a standardized questionnaire. DISCUSSION: To date, the pathophysiology and risk factors of stunting and PEE have been insufficiently investigated. AFRIBIOTA will add new insights into the pathophysiology underlying stunting and PEE and in doing so will enable implementation of new biomarkers and design of evidence-based treatment strategies for these two syndromes.

Difficultés et défis de la prise en charge de la hernie diaphragmatique congénitale à Madagascar

Objectifs. Le pronostic de la hernie diaphragmatique congénitale (HDC) est sévère, avec un taux de mortalité néonatale de 30 à 60%. Notre objectif était de décrire le profil clinique des patients porteurs d'une HDC et de discuter les résultats des modalités thérapeutiques en milieu défavorisé. Patients et méthodes. Il s'agit d'une étude rétrospective descriptive durant une période de 3 ans, allant de janvier 2008 à décembre 2011 au sein du CHU/JRA à Madagascar. Sept dossiers d'enfants porteurs d'une hernie diaphragmatique ont été colligés durant cette période dont cinq hernies de Bochdalek et deux hernies de Larrey-Morgagni. Les paramètres analysés étaient les données cliniques et radiologiques, les modalités thérapeutiques et l'évolution après traitement. Résultats. L'âge médian des sept enfants (cinq garçons et deux filles) était de 14,71 mois. Aucun diagnostic anténatal n'a été posé. Le diagnostic clinique a été suggéré par la présence d'un syndrome de détresse respiratoire chez six enfants et de signes digestifs chez un patient. La radiographie thoraco-abdominale avec sonde nasogastrique en place a retrouvé des signes directs chez six enfants et indirects chez quatre enfants. L'opacification digestive et le scanner ont été utilisés chez deux enfants pour confirmer le diagnostic et faire un bilan anatomique précis. Il y avait cinq cas de hernie de Bochdalek et deux cas de hernie de Larrey-Morgagni. Une chirurgie conventionnelle a été effectuée chez cinq enfants. Quatre nouveau-nés sont décédés dont deux en préopératoire et deux autres en postopératoire dont un à cause d'une infection nosocomiale. Conclusion. La HDC est une malformation congénitale sévère, de prise en charge difficile. Le taux de mortalité en est élevé dont la moitié des cas en période postopératoire, justifiant la mise en place de protocoles thérapeutiques et l'organisation d'un suivi multidisciplinaire