Identification moleculaire des champignons des semences chez l\u2019Assamela suivi de leur protection a partir des poudres et extraits issus de plantes medicinales

Seedborne fungi constitute one of the major constraints of natural regeneration of Assamela ( Pericopsis elata ) stands in Cameroon\u2019s forest production. The objective of this study was to evaluate the capacity of a botanical ( Vitex doniana , Paullinia pinnata , Citrus sinensis , Ageratum conyzoides and Carica papaya ) to protect Assamela seeds against seedborne fungal pathogens. Fungal DNA extraction was done using the Zymo Research Kit and the internal transcribe spacer (ITS) portions of ribosomal DNA genes were sequenced. Plant powders were tested at 10% (mass/mass) and the efficiency of the aqueous and ethanolic extracts was evaluated at 100 g ml-1 and 48 g ml-1, respectively. Thirame (reference fungicide) was used as positive control. Pathogenic seedborne fungi were found to be Aspergillus niger , Macrophomina phaseolina , Aspergillus flavus and Fusarium equiseti. Seed infection was 67% in the negative control. Seeds stored in plant powders gave infection rates of less than 8% (P<0.05) comparable to those of the synthesis fungicide Thirame (3.33%). The powders had no effect on germination at 10%. Only aqueous extracts of Citrus sinensis, Ageratum conyzoides and Carica papaya gave high germinations of 92, 92 and 97%, respectively. The plant powders tested and the aqueous extract of A. conyzoides could be considered as alternatives to chemical protection of P. elata seeds.Les champignons des semences constituent l\u2019une des contraintes majeures de r\ue9g\ue9n\ue9ration naturelle des peuplements de l\u2019Assamela ( Pericopsis elata ) dans les for\ueats de production au Cameroun. Cette \ue9tude a avait pour objectif de contribuer \ue0 la protection des semences chez l\u2019assamela par l\u2019utilisation des substances naturelles d\u2019origine v\ue9g\ue9tale ( Vitex doniana , Paullinia pinnata , Citrus sinensis , Ageratum conyzoides et Carica papaya ). Le Kit (Zymo Research) a \ue9t\ue9 utilis\ue9 pour l\u2019extraction d\u2019ADN des champignons et les portions ITS des g\ue8nes de l\u2019ADN ribosomial s\ue9quenc\ue9s. Les poudres v\ue9g\ue9tales ont \ue9t\ue9 test\ue9es \ue0 10% (m m-1) et les extraits aqueux et \ue9thanoliques, aux concentrations respectives de 100 g ml-1 et 48 g ml-1. Le fongicide Thirame a \ue9t\ue9 utilis\ue9 comme t\ue9moin positif. Les champignons pathog\ue8nes des semences ont \ue9t\ue9\ua0: Aspergillus niger , Macrophomina phaseolina , Aspergillus flavus et Fusarium equiseti. Le taux d\u2019infection des semences a \ue9t\ue9 de 67% chez le lot t\ue9moin n\ue9gatif. Les semences conserv\ue9es dans les poudres ont donn\ue9 des taux d\u2019infections inf\ue9rieurs \ue0 8% significativement comparable (P<0,05) \ue0 ceux du fongicide de synth\ue8se Thirame (3,33%). Les poudres n\u2019ont pas eu d\u2019effet sur la germination \ue0 la concentration test\ue9e10%. Seuls les extraits aqueux de Citrus sinensis, Ageratum conyzoides et Carica papaya ont offert des taux de germination \ue9l\ue9v\ue9s de 92\ua0; 92 et 97% respectivement. Les poudres test\ue9es et l\u2019extrait aqueux de A. conyzoides pourraient constituer des alternatives \ue0 la protection chimique des semences de P. elata

Acceptability and feasibility of human papillomavirus vaccination for adolescents in school environments in Libreville

Background: High-risk oncogenic human papillomaviruses (HPV) are the cause of sexually transmitted viral infection. Its persistence is a risk factor for precancerous lesions of the cervix, which will constitute the base of cervical cancer. In the world, the prevalence of high-risk oncogenic HPV is 66.7%, which is higher among women starting their sexual activity.Methods: An analytical cross-sectional study was conducted in high schools in Gabon regarding parents. The variables selected were the socio-cultural and demographic characteristics of the parents, their knowledge of human papillomavirus vaccination and their acceptability of HPV vaccination and finally the feasibility of HPV vaccination. The statistical test used was Pearson's Chi-square, and a difference was considered significant for p<0.05.Results: The majority of parents, 89%, were informed of the existence of cervical cancer. However, 73.4% of them were unaware of the existence of vaccination against cervical cancer. Only 2.4% of parents had vaccinated their daughters against cervical cancer at the time of the study. These parents only 53.4% expressed an interest in vaccinating their daughters in 53.4% of cases. The ability to vaccinate children is associated with the socio-professional status of parents (p˂0.000).Conclusions: The majority of parents approved school-based vaccination against human papillomavirus infections despite its reported cost and lack of information. The integration of anti-HPV vaccination into the expanded programme on immunization in Gabon will improve immunization coverage

Champignons pathogènes associés aux semences de Pericopsis elata et effet des substrats sur la germination, la croissance et l'infection des plantules au Cameroun

Résumé L’objectif de cette étude est d’identifier les champignons associés aux semences chez Pericopsis elata et de tester l’effet des substrats sur la germination, la croissance et l’infection des plantules. Ainsi, des échantillons de semences ont été collectés à partir des gousses dans les localités de Mindourou et de Bidou puis, emportés dans le Laboratoire de Phytopathologie de l’Université de Dschang pour l’isolement et l’identification des champignons à partir des techniques classiques reconnues. Parallèlement, quatre substrats de germination constitués de la terre rouge forestière, du terreau noir, du mélange terre rouge forestière + sable et du mélange terre rouge forestière + fiente de poule ont été considérés pour évaluer l’aptitude des plantules à y croitre dans la zone forestière de Mindourou. L’étude montre que les semences de P. elata sont colonisées par divers champignons d’importance phytopathologique dont les espèces les plus fréquemment isolées sont : Rhizoctonia solani (21,13%), Cercospora sp (17,60%), Aspergillus niger (12, 67%), Aspergillus flavus (9, 15%), Colletotrichum gloeosporioides (9, 15%) et Fusarium sp (8, 45%). Le substrat sable + terre rouge forestière à la proportion 3:1 a donné le taux de germination le plus élevé (72%), 16 jours après semis et le taux d’infection des semences le plus bas significativement semblable au substrat terre rouge forestière (P˂0,05). La hauteur des plantules a été la plus élevée dans le substrat terre rouge +fiente de poule à la proportion 3:1 et a atteint 26 cm, 12 semaines après semis. Le taux d’infection des plantules a été le plus faible dans le substrat terre rouge forestière (2,8%). L’étude montre que le substrat terre rouge forestière est approprié pour la croissance des plantules. Les champignons des semences constituent l’une des contraintes majeures de germination des semences de P. elata dans les forêts de production au Cameroun ; certains poursuivraient leur développement sur les plantules et entraîneraient diverses maladies foliaires et caulinaires responsables de la mort des plantules

Zeolite Y Crystals with Trimodal Porosity as Ideal Hydrocracking Catalysts

Effektive Poren: Zeolith-Y-Kristalle mit Mikroporen (ca. 1 nm), kleinen (ca. 3 nm) und großen Mesoporen (ca. 30 nm) wurden aus zuvor mit Dampf und Säure behandeltem Material durch Auslaugen mit Base erhalten. Die Zeolith-Y-Kristalle mit trimodaler Porosität (siehe elektronentomographische Aufnahme) zeigen beim Hydrocracking eine nahezu ideale Selektivität für und erhöhte Ausbeuten an Kerosin und Diesel

Zeolite Y Crystals with Trimodal Porosity as Ideal Hydrocracking Catalysts

Effektive Poren: Zeolith-Y-Kristalle mit Mikroporen (ca. 1 nm), kleinen (ca. 3 nm) und großen Mesoporen (ca. 30 nm) wurden aus zuvor mit Dampf und Säure behandeltem Material durch Auslaugen mit Base erhalten. Die Zeolith-Y-Kristalle mit trimodaler Porosität (siehe elektronentomographische Aufnahme) zeigen beim Hydrocracking eine nahezu ideale Selektivität für und erhöhte Ausbeuten an Kerosin und Diesel

Adherence to Antiretroviral Therapy (ART) in Yaoundé-Cameroon: Association with Opportunistic Infections, Depression, ART Regimen and Side Effects.

Following global efforts to increase antiretroviral therapy (ART) access in Sub-Saharan Africa, ART coverage among HIV-infected Cameroonians increased from 0% in 2003 to 22% in 2014. However, the success of current HIV treatment programs depends not only on access to ART, but also on retention in care and good treatment adherence. This is necessary to achieve viral suppression, prevent virologic failure, and reduce viral transmission and HIV/AIDS-related deaths. Previous studies in Cameroon showed poor adherence, treatment interruption, and loss to follow-up among HIV+ subjects on ART, but the factors that influence ART adherence are not well known. In the current cross-sectional study, patient/self-reported questionnaires and pharmacy medication refill data were used to quantify ART adherence and determine the factors associated with increased risk of non-adherence among HIV-infected Cameroonians. We demonstrated that drug side-effects, low CD4 cell counts and higher viral loads are associated with increased risk of non-adherence, and compared to females, males were more likely to forego ART because of side effects (p40 years) were less likely to be non-adherent (p<0.01) and had shorter non-adherent periods (p<0.0001). The presence of depression symptoms correlated with non-adherence to ART during antibiotic treatment (r = 0.53, p = 0.04), and was associated with lower CD4 cell counts (p = 0.04) and longer non-adherent periods (p = 0.04). Change in ART regimen was significantly associated with increased likelihood of non-adherence and increased duration of the non-adherence period. Addressing these underlying risk factors could improve ART adherence, retention in care and treatment outcomes for HIV/AIDS patients in Cameroon

Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15- O-acetate as the main active compound.

ABSTRACT: BACKGROUND: Natural products could play an important role in the challenge to discover new anti-malarial drugs. In a previous study, Dicoma tomentosa (Asteraceae) was selected for its promising anti-plasmodial activity after a preliminary screening of several plants traditionally used in Burkina Faso to treat malaria. The aim of the present study was to further investigate the antiplasmodial properties of this plant and to isolate the active anti-plasmodial compounds. METHODS: Eight crude extracts obtained from D. tomentosa whole plant were tested in vitro against two Plasmodium falciparum strains (3D7 and W2) using the p-LDH assay (colorimetric method). The Peters' four-days suppressive test model (Plasmodium berghei-infected mice) was used to evaluate the in vivo anti-plasmodial activity. An in vitro bioguided fractionation was undertaken on a dichloromethane extract, using preparative HPLC and TLC techniques. The identity of the pure compound was assessed using UV, MS and NMR spectroscopic analysis. In vitro cytotoxicity against WI38 human fibroblasts (WST-1 assay) and haemolytic activity were also evaluated for extracts and pure compounds in order to check selectivity. RESULTS: The best in vitro anti-plasmodial results were obtained with the dichloromethane, diethylether, ethylacetate and methanol extracts, which exhibited a high activity (IC50 [less than or equal to] 5 mug/ml). Hot water and hydroethanolic extracts also showed a good activity (IC50 [less than or equal to] 15 mug/ml), which confirmed the traditional use and the promising anti-malarial potential of the plant. The activity was also confirmed in vivo for all tested extracts. However, most of the active extracts also exhibited cytotoxic activity, but no extract was found to display any haemolytic activity. The bioguided fractionation process allowed to isolate and identify a sesquiterpene lactone (urospermal A-15-O-acetate) as the major anti-plasmodial compound of the plant (IC50 < 1 mug/ml against both 3D7 and W2 strains). This was also found to be the main cytotoxic compound (SI =3.3). While this melampolide has already been described in the plant, this paper is the first report on the biological properties of this compound. CONCLUSIONS: The present study highlighted the very promising anti-plasmodial activity of D. tomentosa and enabled to identify its main active compound, urospermal A-15-O-acetate. The high antiplasmodial activity of this compound merits further study about its anti-plasmodial mechanism of action. The active extracts of D. tomentosa, as well as urospermal A 15-Oacetate, displayed only a moderate selectivity, and further studies are needed to assess the safety of the use of the plant by the local population

Effects of HIV on executive function and verbal fluency in Cameroon

Abstract HIV-associated neurocognitive disorders (HAND) are frequently associated with impaired executive function and verbal fluency. Given limited knowledge concerning HAND in Sub-Saharan-Africa and lack of Cameroonian adult neuropsychological (NP) test norms, we administered four executive function [Halstead Category Test (HCT), Wisconsin Card Sorting Test (WCST), Color Trails-II (CTT2), and Stroop Color-Word-Interference (SCWT)] and three verbal fluency (Category, Action, and Letter Fluency) tests to 742 adult Cameroonians (395 HIV−, 347 HIV+). We developed demographically-corrected NP test norms and examined the effects of HIV and related variables on subjects’ executive function and verbal fluency. HIV+ subjects had significantly lower T-scores on CTT2 (P = 0.005), HCT (P = 0.032), WCST (P < 0.001); lower executive function composite (P = 0.002) and Action Fluency (P = 0.03) T-scores. ART, viremia, and CD4 counts did not affect T-scores. Compared to cases harboring other viral subtypes, subjects harboring HIV-1 CRF02_AG had marginally higher CTT2 T-scores, significantly higher SCWT (P = 0.015) and executive function (P = 0.018) T-scores. Thus, HIV-1 infection in Cameroon is associated with impaired executive function and some aspects of verbal fluency, and viral genotype influenced executive function. We report the first normative data for assessing executive function and verbal fluency in adult Cameroonians and provide regression-based formulas for computing demographically-adjusted T-scores. These norms will be useful for investigating HIV/AIDS and other diseases affecting cognitive functioning in Cameroon

Effects of HIV on executive function and verbal fluency in Cameroon

HIV-associated neurocognitive disorders (HAND) are frequently associated with impaired executive function and verbal fluency. Given limited knowledge concerning HAND in Sub-Saharan-Africa and lack of Cameroonian adult neuropsychological (NP) test norms, we administered four executive function [Halstead Category Test (HCT), Wisconsin Card Sorting Test (WCST), Color Trails-II (CTT2), and Stroop Color-Word-Interference (SCWT)] and three verbal fluency (Category, Action, and Letter Fluency) tests to 742 adult Cameroonians (395 HIV-, 347 HIV+). We developed demographically-corrected NP test norms and examined the effects of HIV and related variables on subjects' executive function and verbal fluency. HIV+ subjects had significantly lower T-scores on CTT2 (P = 0.005), HCT (P = 0.032), WCST (P &lt; 0.001); lower executive function composite (P = 0.002) and Action Fluency (P = 0.03) T-scores. ART, viremia, and CD4 counts did not affect T-scores. Compared to cases harboring other viral subtypes, subjects harboring HIV-1 CRF02_AG had marginally higher CTT2 T-scores, significantly higher SCWT (P = 0.015) and executive function (P = 0.018) T-scores. Thus, HIV-1 infection in Cameroon is associated with impaired executive function and some aspects of verbal fluency, and viral genotype influenced executive function. We report the first normative data for assessing executive function and verbal fluency in adult Cameroonians and provide regression-based formulas for computing demographically-adjusted T-scores. These norms will be useful for investigating HIV/AIDS and other diseases affecting cognitive functioning in Cameroon