La nutrition en conditions extrêmes

Nutritional reference intakes are build to cover the nutritional needs of the majority of the “normal“ population in a “normal“ environment. Much work is needed to define references for extreme situations. Beside extreme situations such as pathology, under or over nutrition, the study of other extreme conditions could lead to useful insights in pathophysiological mechanisms. Man adaptation to cold temperatures, altitude or spatial flights leads to the development of experimental models, the utility of which goes far beyond the studied conditions: the regulation of appetite and of the metabolisms of proteins, carbohydrates or calcium provides interesting examples.     

MECP2 duplication syndrome in a patient from Cameroon

MECP2 duplication syndrome (MDS; OMIM 300260) is an X‐linked neurodevelopmental disorder caused by nonrecurrent duplications of the Xq28 region involving the gene methyl‐CpG‐binding protein 2 (MECP2; OMIM 300005). The core phenotype of affected individuals includes infantile hypotonia, severe intellectual disability, very poor‐to‐absent speech, progressive spasticity, seizures, and recurrent infections. The condition is 100% penetrant in males, with observed variability in phenotypic expression within and between families. Features of MDS in individuals of African descent are not well known. Here, we describe a male patient from Cameroon, with MDS caused by an inherited 610 kb microduplication of Xq28 encompassing the genes MECP2, IRAK1, L1CAM, and SLC6A8. This report supplements the public data on MDS and contributes by highlighting the phenotype of this condition in affected individuals of African descent.     

Sickle cell disease,sickle trait and the risk for venous thromboembolism: a systematic review and meta-analysis

Background

Globally, sickle cell disease (SCD) is one of the most common haemoglobinopathy. Considered a public health problem, it leads to vessel occlusion, blood stasis and chronic activation of the coagulation system responsible for vaso-occlussive crises and venous thromboembolism (VTE) which may be fatal. Although contemporary observational studies suggest a relationship between SCD or sickle trait (SCT) and VTE, there is lack of a summary or meta-analysis data on this possible correlation. Hence, we propose to summarize the available evidence on the association between SCD, SCT and VTE including deep vein thrombosis (DVT) and pulmonary embolism (PE).

Methods

We searched PubMed and Scopus to identify all cross-sectional, cohort and case-control studies reporting on the association between SCD or SCT and VTE, DVT or PE in adults or children from inception to April 25, 2017. For measuring association between SCD or SCT and VTE, DVT, or PE, a meta-analysis using the random-effects method was performed to pool weighted odds ratios (OR) of risk estimates.

Results

From 313 records initially identified from bibliographic databases, 10 studies were eligible and therefore included the meta-analysis. SCD patients had significantly higher risk for VTE (pooled OR 4.4, 95%CI 2.6–7.5, p?<?0.001), DVT (OR 1.1, 95% CI 1.1–1.2, p?<?0.001) and PE (pooled OR 3.7, 95% CI 3.6–3.8, p?<?0.001) as compared to non SCD-adults. A higher risk of VTE (OR 33.2, 95% CI 9.7–113.4, p?<?0.001) and DVT (OR 30.7, 95% CI 1.6–578.2, p =?0.02) was found in pregnant or postpartum women with SCD as compared to their counterparts without SCD. Compared to adults with SCT, the risk of VTE was higher in adults with SCD (pooled OR 3.1, 95% CI 1.8–5.3, p?<?0.001), and specifically in SCD pregnant or postpartum women (OR 20.3, 95% CI 4.1–102, p?=?0.0003). The risk of PE was also higher in adults with SCD (OR 3.1, 95% CCI 1.7–5.9, p?=?0.0004) as compared to those with SCT. The risk of VTE was higher in individuals with SCT compared to controls (pooled OR 1.7, 95% CI 1.3–2.2, p?<?0.0001), but not in pregnant or postpartum women (OR 0.9, 95% CI 0.3–2.9, p?=?0.863). Compared to controls, SCT was associated with a higher risk of PE (pooled OR 2.1, 95% CI 1.2–3.8, p?=?0.012) but not of DVT (pooled OR 1.2, 95% CI 0.9–1.7, p?=?0.157).

Conclusion

Individuals with SCD, especially pregnant or postpartum women, might have a higher risk of VTE compared to the general population. SCT might also increases the risk of VTE. However, currently available data are not sufficient to allow a definite conclusion. Further larger studies are needed to provide a definitive conclusion on the association between SCD, SCT and VTE.

     

Aetiology of childhood hearing loss in Cameroon (sub-Saharan Africa)

BackgroundSevere hearing loss is a global problem affecting particularly developing countries. There is scarcity of recent published data on the epidemiology of childhood deafness in sub-Saharan Africa.ObjectiveTo determine the etiological profile of severe childhood deafness in Cameroon.MethodsProspective cross-sectional study of patients with a severe hearing loss that started before the age of 15 years. Detailed family and medical history was obtained; careful clinical, otological and audiological examinations were performed.ResultsA total of 582 patients with a severe hearing loss were examined. Prelingual deafness accounted for 75.1% (n = 437), with a mean age at medical diagnosis of 3.3 ± 1.2 years. This late presentation may be explained by limited parental awareness of signs raising suspicion of hearing loss, poor access to health care and the absence of neonatal screening for hearing loss in Cameroon. Identified genetic causes accounted for 14.8% (n = 86), putative environmental causes for 52.6% (n = 306) and unknown causes for 32.6% (n = 190). Amongst Genetic causes, the syndromic hearing loss accounted for 13.1% (n = 12) of cases, the rest being non syndromic (n = 74). Consanguineous families accounted for 5.7% (n = 33) of the whole sample, and 15.1% (n = 13) of genetic cases. No union between deaf parents was observed.ConclusionThese data highlight the possible predominance of putative environmental causes of childhood deafness in Cameroon, and emphasize the need for improved policies for prevention of infectious diseases and for neonatal hearing screening. However, further molecular analyses and targeted CT scan investigations are required to more accurately gauge the contribution of genetics etiologies.     

A flow cytometry‐based assay for measuring invasion of red blood cells by Plasmodium falciparum

Variability in the ability of the malaria parasite Plasmodium falciparum to invade human erythrocytes is postulated to be an important determinant of disease severity. Both the parasite multiplication rate and erythrocyte selectivity are important parameters that underlie such variable invasion. We have established a flow cytometry‐based method for simultaneously calculating both the parasitemia and the number of multiply‐infected erythrocytes. Staining with the DNA‐specific dye SYBR Green I allows quantitation of parasite invasion at the ring stage of parasite development. We discuss in vitro and in vivo applications and limitations of this method in relation to the study of parasite invasion. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.     

Le curseur nutritionnel: un nouvel outil visuel d’information nutritionnelle

The nutritional cursor is a new nutritional information tool which allows food of the same category to be classified into three groups: “nutritional pleasure”, “classical pleasure” and “great pleasure”. The classification will be determined following the product composition on the basis of a factorial analysis method followed by an automatic classification. It will then be checked a posteriori by experts. The classification is based on nutritional criteria which are specific for each category of food. The nutritional cursor provides a nutritional profile of the product but, contrary to the other proposals the classification, it is built a posteriori according to market reality. Categories are defined pragmatically on the basis of consumer attitudes. Buying food will thus be simplified for the consumer and the new labelling scheme will heighten his awareness of food variety. It also enables him to adopt a healthy diet as well as make him be conscious of what he buys without feeling guilty. The cursor will be changing gradually according to the market evolution and public health recommendations.