Troisième cours international portant sur la microbiologie de M. ulcerans (M2U) à Yaoundé

International audienc

Characterization and Bioremediation of Birch Condensate

Birch (Betula papyrifera Marsh) condensate collected from a veneer plant in Michigan was analyzed for its major chemical constituents. This condensate contained carbohydrates and lipids. In the lipid fractions, triglycerides were the most abundant component (35-40%), followed by phenolic compounds (30%) and waxes (25-30%). Gas Chromatography-Mass Spectrometry (GC-MS) and Fast Atom Bombardment (FAB) MS were used to identify 14 lipid compounds. A white rot fungus, Phanerochaete chrysosporium [Burdsall-lombard, 5176, HHB-6251], was tested as a means for the bio-remediation of the condensate. P. chrysosporium reduced the total organic content (TOC) of the condensate from 350 ppm to 22 ppm and the color intensity from 0.614 to 0.355 absorbance units, after 2 weeks incubation in a liquid medium containing yeast and peptonc at pH 5

Crises epileptiques au cours de la toxoplasmose cerebrale chez les patients immunodeprimes au vih.

Objectif Décrire les caractéristiques des crises épileptiques au cours de la toxoplasmose cérébrale (TC) chez les patients immunodéprimés au VIH à l’Hôpital Général de Douala (HGD).Matériel méthodesIl s’agissait d’une étude descriptive rétrospective des cas de TC diagnostiquée entre janvier 2000 et décembre 2012. La prévalence, le type, la fréquence des crises épileptiques et les thérapeutiques antiépileptiques ont été étudiées. Les patients avec un antécédent de crises épileptiques étaient exclus. Le test de Khi-2 a été utilisé pour rechercher les facteurs associés à la survenue des crises épileptiques tandis que le test de Student a été utilisé pour comparer les moyennes. P < 0,05 était considéré comme statistiquement significatif.Résultats 146 patients étaient inclus avec 78 femmes pour un sex-ratio de 0,87 en faveur des femmes. L’âge moyen était de 39,38 ± 9,88 ans. Le taux de CD4 moyen était de 115,63 ± 142,70 éléments/ml. La prévalence des crises épileptiques était de 45,2% et 61% des épileptiques étaient répétées. Les crises épileptiques généralisées prédominaient avec 75,8%. Seuls la fièvre (p < 0,012), les céphalées (p < 0,004), le syndrome d’hypertension intracrânienne (p < 0,038), un taux de CD4 < 50/ mm3 (p < 0,02) et un taux d’hémoglobine < 10g/dl (p < 0,017) étaient statistiquement associés à la survenue des crises épileptiques. Un traitement antiépileptique était prescrit chez 43,2% des patients.Conclusion Les crises épileptiques sont fréquentes au cours de la toxoplasmose cérébrale. Elles peuvent se répéter et justifier d’un traitement antiépileptique.Mots clés : Toxoplasmose cérébrale, VIH, Crises épileptiques, Douala, Cameroun

Plasma Letrozole Concentrations in Postmenopausal Women With Breast Cancer Are Associated With CYP2A6 Genetic Variants, Body Mass Index, and Age

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109858/1/cptclpt2011174.pd

Melanin production inhibitors from the West African 'Cassipourea congoensis'

Cassipourea congoensis (syn. Cassipourea malosana) is used in African countries as a skin-lightening agent. Two previously unreported cycloartane triterpenoids, 26-hydroxy-3-keto-24-methy lenecycloartan-30-oic acid 1 and 24-methylene-cycloartan-3β,26,30-triol 2 along with the known mahuannin B 3, 7-methoxymahuannin B 4, 7-methoxygeranin A 5, methyl-3-(4-hydroxy-3-methoxyphenyl)-2E-propenoate, glycerol-1-alkanoate, (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal 6, (-)-syringaresinol 7, and stigmast-5-en-3-O-β-D-glucoside, were isolated from the roots of C. congoensis. The crude extract and compounds 1 and 5 were found to inhibit the production of melanin at 10 μM with low cytotoxicity validating the ethno-medicinal use of this plan

Ethnoknowledge of medicinal and mystical plants used by healers in Juazeiro do Norte, Ceará, Northeast Brazil

154-166The aim of this study was to investigate the use of medicinal plants by healers in Juazeiro do Norte, Northeast Brazil, as well as to understand their role in prayer/healing practices. 30 residents from 20 neighborhoods, 18 urban neighborhoods and 2 randomly selected rural locations, were interviewed using a sample method known as "snowball", with two pilot interviews being initially conducted, where for greater method reliability and for the analysis of the importance attributed to the plants by the respondents, a calculation to determine their Relative Importance (RI) index was used. The results indicate the use of 60 species distributed across 34 families. The most representative families were: Fabaceae (7), Lamiaceae (6) and Asteraceae (5), where 10 species (eight exotic and two native) obtained a Relative Importance (RI>1): Ruta graveolens L. (1.47), Vernonia condensata Baker (1.47), Piper aduncun L. (1.44), Mentha spicata L. (1.33), Myracrodruon urundeuva Allemão (1.3), Psidium guajava L. (1.19), Hymenaea stignocarpa Mart. ex. Hayne (1.15), Lippia alba (Mil.) (1.11), Leonotis nepetaefolia (L.) R. Br. (1.08) and Cymbopogon citratus (D.C.) Stapf (1.01). The aforementioned species are acquired from backyards (50%), open markets (33.3%) or from surrounding scrubs (16.6%). Indications included usage for 11 body systems, with 36 species (60%) being indicated for the treatment of the digestive system and 15 (25%) for the treatment of diseases of the female reproductive system. Nine species (15%) were indicated for ritualistic purposes (prayer/healing). With this, the importance of the Healer figure in several municipal districts was observed, a tradition that remains alive, despite the need for greater transmission and assimilation to upcoming generations

Targeting Antibody Responses to the Membrane Proximal External Region of the Envelope Glycoprotein of Human Immunodeficiency Virus

Although human immunodeficiency type 1 (HIV-1) infection induces strong antibody responses to the viral envelope glycoprotein (Env) only a few of these antibodies possess the capacity to neutralize a broad range of strains. The induction of such antibodies represents an important goal in the development of a preventive vaccine against the infection. Among the broadly neutralizing monoclonal antibodies discovered so far, three (2F5, Z13 and 4E10) target the short and hidden membrane proximal external region (MPER) of the gp41 transmembrane protein. Antibody responses to MPER are rarely observed in HIV-infected individuals or after immunization with Env immunogens. To initiate antibody responses to MPER in its membrane-embedded native conformation, we generated expression plasmids encoding the membrane-anchored ectodomain of gp41 with N-terminal deletions of various sizes. Following transfection of these plasmids, the MPER domains are displayed on the cell surface and incorporated into HIV virus like particles (VLP). Transfected cells displaying MPER mutants bound as efficiently to both 2F5 and 4E10 as cells transfected with a plasmid encoding full-length Env. Mice immunized with VLPs containing the MPER mutants produced MPER-specific antibodies, the levels of which could be increased by the trimerization of the displayed proteins as well as by a DNA prime-VLP boost immunization strategy. Although 2F5 competed for binding to MPER with antibodies in sera of some of the immunized mice, neutralizing activity could not be detected. Whether this is due to inefficient binding of the induced antibodies to MPER in the context of wild type Env or whether the overall MPER-specific antibody response induced by the MPER display mutants is too low to reveal neutralizing activity, remains to be determined

Roadless wilderness area determines forest elephant movements in the Congo Basin

A dramatic expansion of road building is underway in the Congo Basin fuelled by private enterprise, international aid, and government aspirations. Among the great wilderness areas on earth, the Congo Basin is outstanding for its high biodiversity, particularly mobile megafauna including forest elephants (Loxodonta africana cyclotis). The abundance of many mammal species in the Basin increases with distance from roads due to hunting pressure, but the impacts of road proliferation on the movements of individuals are unknown. We investigated the ranging behaviour of forest elephants in relation to roads and roadless wilderness by fitting GPS telemetry collars onto a sample of 28 forest elephants living in six priority conservation areas. We show that the size of roadless wilderness is a strong determinant of home range size in this species. Though our study sites included the largest wilderness areas in central African forests, none of 4 home range metrics we calculated, including core area, tended toward an asymptote with increasing wilderness size, suggesting that uninhibited ranging in forest elephants no longer exists. Furthermore we show that roads outside protected areas which are not protected from hunting are a formidable barrier to movement while roads inside protected areas are not. Only 1 elephant from our sample crossed an unprotected road. During crossings her mean speed increased 14-fold compared to normal movements. Forest elephants are increasingly confined and constrained by roads across the Congo Basin which is reducing effective habitat availability and isolating populations, significantly threatening long term conservation efforts. If the current road development trajectory continues, forest wildernesses and the forest elephants they contain will collapse

Resistance of African tropical forests to an extreme climate anomaly.

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015-2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015-2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha-1 y-1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests