Severe malaria: what's new on the pathogenesis front?

Plasmodium falciparum causes the most severe and fatal form of malaria in humans with over half a million deaths each year. Cerebral malaria, a complex neurological syndrome of severe falciparum malaria, is often fatal and represents a major public health burden. Despite vigorous efforts, the pathophysiology of cerebral malaria remains to be elucidated, thereby hindering the development of adjunctive therapies. In recent years, multidisciplinary and collaborative approaches have led to groundbreaking progress both in the laboratory and in the field. Here we review the latest breakthroughs in severe malaria pathogenesis, with a specific focus on new pathogenetic mechanisms leading to cerebral malaria. The most recent findings point towards specific parasite phenotypes targeting brain microvasculature, endothelial dysfunction and subsequent oedema-induced brain swelling

Spectroscopic detection of carbon nanotube interaction with amphiphilic molecules in epoxy resin composites

Incorporation of carbon nanotubes into epoxy resin composites has the effect of increasing electrical conductivity at low percolation levels. An amphiphilic molecule such as palmitic acid has been used to increase the surface contact area and improve the dispersion of the carbon nanotube bundles in the prepolymer. The chemical environment of the dispersed nanotubes has been probed using vibrational Raman spectroscopy. Spectroscopic Raman maps, on sample surfaces (60x60 µm2) with ratios of nanotubes to palmitic acid varying from 1:2 to 2:1 by weight, have been recorded to test the uniformity of the dispersion. Substantial spatial inhomogeneities have been observed in the G-band shift and an additional spectral band at 1450 cm-1. The 1450 cm-1 band has been attributed to the CH3 group of the amphiphilic molecules adsorbed onto the nanotube surface. The maps are correlated with the measured electrical conductivity values. The highest conductivity has been observed for the best dispersed nanotubes and nanotubes with the highest degree of interaction

A novel high efficiency, low maintenance, hydroponic system for synchronous growth and flowering of Arabidopsis thaliana

BACKGROUND: Arabidopsis thaliana is now the model organism for genetic and molecular plant studies, but growing conditions may still impair the significance and reproducibility of the experimental strategies developed. Besides the use of phytotronic cabinets, controlling plant nutrition may be critical and could be achieved in hydroponics. The availability of such a system would also greatly facilitate studies dealing with root development. However, because of its small size and rosette growth habit, Arabidopsis is hardly grown in standard hydroponic devices and the systems described in the last years are still difficult to transpose at a large scale. Our aim was to design and optimize an up-scalable device that would be adaptable to any experimental conditions. RESULTS: An hydroponic system was designed for Arabidopsis, which is based on two units: a seed-holder and a 1-L tank with its cover. The original agar-containing seed-holder allows the plants to grow from sowing to seed set, without transplanting step and with minimal waste. The optimum nitrate supply was determined for vegetative growth, and the flowering response to photoperiod and vernalization was characterized to show the feasibility and reproducibility of experiments extending over the whole life cycle. How this equipment allowed to overcome experimental problems is illustrated by the analysis of developmental effects of nitrate reductase deficiency in nia1nia2 mutants. CONCLUSION: The hydroponic device described in this paper allows to drive small and large scale cultures of homogeneously growing Arabidopsis plants. Its major advantages are its flexibility, easy handling, fast maintenance and low cost. It should be suitable for many experimental purposes

Vascular endothelial cells cultured from patients with cerebral or uncomplicated malaria exhibit differential reactivity to TNF.

Plasmodium falciparum malaria is a major cause of morbidity and mortality in African children, and factors that determine the development of uncomplicated (UM) versus cerebral malaria (CM) are not fully understood. We studied the ex vivo responsiveness of microvascular endothelial cells to pro-inflammatory stimulation and compared the findings between CM and UM patients. In patients with fatal disease we compared the properties of vascular endothelial cells cultured from brain tissue to those cultured from subcutaneous tissue, and found them to be very similar. We then isolated, purified and cultured primary endothelial cells from aspirated subcutaneous tissue of patients with CM (EC(CM) ) or UM (EC(UM) ) and confirmed the identity of the cells before analysis. Upon TNF stimulation in vitro, EC(CM) displayed a significantly higher capacity to upregulate ICAM-1, VCAM-1 and CD61 and to produce IL-6 and MCP-1 but not RANTES compared with EC(UM) . The shedding of endothelial microparticles, a recently described parameter of severity in CM, and the cellular level of activated caspase-3 were both significantly greater in EC(CM) than in EC(UM) . These data suggest that inter-individual differences in the endothelial inflammatory response to TNF may be an additional factor influencing the clinical course of malaria

Risk factors of maternity blues after caesarean section in Yaoundé, Cameroon: a case-control analysis

Background: Maternity blues is the most precocious and common mental derangement of the puerperium. Our objective was to identify its risk factors in women delivered by cesarean section.Methods: This was a case-control study carried out from January 10th to April 10th 2015 in two referral hospitals of Yaoundé, Cameroon, involving 321 women delivered by cesarean section, 107 of which presented maternity blues.Results: After multivariate analysis, independent risk factors for maternity blues after cesarean section were: low socio-economic level (OR=3.62; CI=1.35-9.70), personal history of depression (OR=4.36; CI=1.13-16.81), difficulties caring for the baby (OR=3.40; CI=1.12-10.27) and having felt depressed or anxious during pregnancy (OR=6.61; CI=3.05-14.31).Conclusions: Women with identifiable risk factors for maternity blues should be followed up closely after cesarean deliveries

Effets de L’extrait Aqueux des Racines d’Hymenocardia acida (Euphorbiaceae) sur la Qualité du Sperme de Rats

Les racines d’Hymenocardia acida sont utilisées dans la médecine traditionnelle africaine pour traiter principalement la dysfonction érectile. La présente étude vise à évaluer les effets de l’extrait aqueux des racines d’ Hymencardia acida sur la qualité du sperme de rats. Les différents composés chimiques de l’extrait aqueux des racines d’Hymenocardia acida ont été identifiés par des réactions en tube décrites dans la pharmacopée africaine. Deux groupes de quinze rats traités pendant 30 et 60 jours ont été repartis chacun en lot témoin, lot traité à 500 mg/kg et lot traité à 1000 mg/kg de poids corporel. La densité, la motilité et la morphologie des spermatozoïdes ont été évaluées selon des méthodes standards. Le taux de testostérone et le tissu testiculaire ont été étudiés. Le tri phytochimique a révélé la présence de polyphénols, de flavonoïdes, de tanins catéchiques, de saponosides, d’alcaloïdes et de stérols et polyterpènes. L’extrait a favorisé une augmentation significative (P < 0.05) du nombre de spermatozoïdes, des taux de spermatozoïdes mobiles et normaux dans l’épididyme caudal. Il a entrainé également une augmentation significative (P < 0.05) du taux de la testostérone sérique et a favorisé l’accroissement des spermatozoïdes dans les tubes séminifères. Les racines d’Hymenocardia acida améliorent la qualité du sperme des rats. Cela pourrait être dû en grande partie à l’augmentation du taux sérique de la testostérone.   Hymenocardia acida roots are used in traditional African medicine to treat mainly erectile dysfunction. The present study aims to evaluate the effects of aqueous extract of Hymencardia acida roots on the quality of rat sperm. The different chemical compounds of the aqueous extract of the roots of Hymenocardia acida were identified by tube reactions described in the African pharmacopoeia. Two groups of fifteen rats treated for 30 and 60 days were divided into control, 500 mg/kg and 1000 mg/kg body weight. Sperm density, motility and morphology were assessed by standard methods. Testosterone levels and testicular tissue were studied. Phytochemical sorting revealed the presence of polyphenols, flavonoids, catechic tannins, saponosides, alkaloids and sterols and polyterpenes. The extract promoted a significant (P < 0.05) increase in sperm count, motile and normal sperm rates in the caudal epididymis. It also caused a significant increase (P < 0.05) in serum testosterone levels and promoted the increase of spermatozoa in the seminiferous tubules. Hymenocardia acida roots improve sperm quality in rats. This could be due in large part to the increase in serum testosterone levels