Association between cerebral glutamate and human behaviour: the sensation seeking personality trait

INTRODUCTION: Brain imaging studies have linked the anterior cingulate cortex (ACC) to motivation, drive, and personality traits like novelty and sensation seeking. Animal studies have shown glutamatergic neurotransmission to be important in ACC function as well as motivated behaviour. However, the role of glutamate in related personality traits like sensation seeking has not been investigated in humans. METHODS: The associations between sensation seeking personality scores and absolute glutamate concentrations in the ACC and the hippocampal region measured by 3-Tesla proton magnetic resonance spectroscopy (1H-MRS) were investigated. RESULTS: ACC glutamate concentration was negatively correlated with the sensation seeking sum score and the experience seeking subscore. A weak negative correlation was also observed between the hippocampal glutamate and the sensation seeking sum score. The reexamination of the glutamate concentration after 4 weeks revealed a similar relationship with sensation seeking. DISCUSSION: Although preliminary, the results are in line with the key role of the ACC for motivation and executive control and with the impact of glutamate on novelty related behaviour observed in animal experiments. The role of the hippocampus for novelty processing is discussed. Glutamate measurement with 1H-MRS may facilitate the understanding of biological underpinnings of personality traits and psychiatric diseases associated with dysfunctions in motivation and drive.     

Context-specific food-based approach for ensuring nutrition security in developing countries: a review

Sustainable food strategies for meeting nutrient needs in developing countries are not well established. The available evidence shows that more than one-third of the world’s population is facing under-nutrition, of which the most affected individuals are children and mothers from poor countries. In most developing countries, losses resulting from malnutrition are between 3 and 16% of the gross domestic product. This burden is far larger than the donor-driven and government programmes can tackle alone. As such, an innovative approach, which is independent and not donor-based, is needed to reduce the burden of malnutrition in low-income countries. In this review, we describe a context specific food-based approach for addressing malnutrition in developing countries. The approach deploys the hybrid public–private delivery model that enables cost sharing and efficiency gains in resource-poor countries. The model influences players to consider consumers’ perspectives, which often are neglected and truly engage them as key stakeholders.     

Effects of root extracts of Fagara zanthoxyloides on the in vitro growth and stage distribution of Plasmodium falciparum

The development of resistance by Plasmodium falciparum to conventional drugs poses a threat to malaria control. There is therefore a need to find new, effective, and affordable remedies for malaria, including those derived from plants. This study demonstrates that crude, reverse-phase high-pressure liquid chromatography (RP-HPLC)-semipurified, and RP-HPLC-purified root extracts of Fagara zanthoxyloides inhibit the growth of P. falciparum in vitro, with 50% inhibitory concentrations (IC(50)s) of 4.90, 1.00, and 0.13 microg/ml, respectively. Roots of F. zanthoxyloides, known as chewing sticks, are widely used for tooth cleaning in West Africa. Microscopic examination of Giemsa-stained slides showed a virtual absence of schizonts in ring-stage synchronized cultures treated with crude extracts at concentrations of 30 to 60 microg/ml during 36 to 48 h of incubation. These observations suggest that the active constituent in the extract may be cytotoxic for P. falciparum trophozoites, thereby inhibiting their development to the schizont stage. A pure bioreactive fraction was subsequently obtained from the chromatographic separations. When this fraction was mixed with pure fagaronine, the mixture coeluted as a single peak on the analytical RP-HPLC column, suggesting that fagaronine may be the active antimalarial constituent of Fagara root extracts. Additional experiments showed that fagaronine also inhibited P. falciparum growth, with an IC(50) of 0.018 microg/ml. The results of this study suggest that the antimalarial activity of fagaronine deserves further investigation.     

COVID-19: A pluralistic and integrated approach for efficient management of the pandemic

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which triggered the ongoing pandemic, was first discovered in China in late 2019. SARS-CoV-2 is a respiratory virus responsible for coronavirus disease 2019 (COVID-19) that often manifests as a pneumonic syndrome. In the context of the pandemic, there are mixed views on the data provided by epidemiologists and the information collected by hospital clinicians about their patients. In addition, the literature reports a large proportion of patients free of pneumonia vs a small percentage of patients with severe pneumonia among confirmed COVID-19 cases. This raises the issue of the complexity of the work required to control or contain the pandemic. We believe that an integrative and pluralistic approach will help to put the analyses into perspective and reinforce collaboration and creativity in the fight against this major scourge. This paper proposes a comprehensive and integrative approach to COVID-19 research, prevention, control, and treatment to better address the pandemic. Thus, this literature review applies a pluralistic approach to fight the pandemic.