Effets de deux plantes aphrodisiatiques africaines Garcinia kola et Turraea heterophylla sur les performances zootechniques et le taux d’inversion sexuelle chez Oreochromis niloticus

Dans le but développer une méthode alternative au 17-α -méthytestostérone, les effets de Garcinia kola et Turraea heterophylla sur la production des alevins monosexes mâles de Oreochromis niloticus ont été évaluées. Ainsi, 7200 alevins (0,011 ± 0,002 g) ont été répartis dans 24 happas en raison de 300 poissons/happa, formant 8 traitements en triplicata. Huit régimes alimentaires correspondant chacun à un traitement ont été testés. Les régimes témoins négatif et positif contiennent respectivement 0 et 70 mg de méthyltestostérone/kg. Six régimes dont 3 par plante, contiennent respectivement 10, 20 et 30 g d’extrait/kg. Les lots « lot 10g » et « lot 30g » de T. heterophylla présentent respectivement les meilleures croissances et taux de mâle. Les taux optimaux d’extraits sont de 10 et 30 g/kg respectivement pour la croissance et masculinisation. L’augmentation du pourcentage de mâles est dose-dépendante. Les fortes proportions de mâles sont de 76,82 ± 3,34 % pour T. heterophylla et 65,75 ± 4,19 % pour G. kola. Les meilleurs poids moyens enregistrés pour T. heterophylla et G. kola sont respectivement de 0,919 ± 0,059 et 0,663 ± 0,103 g. Les taux de survie sont compris entre 88 et 95 %. Des études complémentaires détermineront les méthodes d’application, les solvants d’extraction et la durée de traitement appropriés à la production d’alevins monosexes mâles.Mots-clés : Oreochromis niloticus, Plantes aphrodisiaques, Inversion sexuelle, Paramètres zootechniques, Côte d’Ivoire

Export papaya post-harvest protection by fungicides and the problems of the maximal limit of residues

The post-harvest maturity of papaya fruits is influenced by several environmental factors including temperature, light and ventilation of the surrounding wall. The maturity, presence and attacks or rots, and the accumulation of fungicide residues in the papaya was evaluated on papaya fruits treated with different fungicide. Thiabendazole-treated fruits did not rot 21 days after treatment and this fungicide was the most satisfactory with detected residues lower than the European Union's 2000/48/EC guideline. Key Words: Post-harvest, papaya, fungicides, phytotoxic, thiabendazole, residues maximal limit. African Journal of Biotechnology Vol.4(1) 2005: 109-11

Pulmonary and Serum Antibody Responses Elicited in Zebu Cattle Experimentally Infected with Mycoplasma mycoides Subsp. mycoides SC by Contact Exposure

The purpose of the present study was to characterize the Mycoplasma mycoides subsp. mycoides small colony (MmmSC)-specific humoral immune response at both systemic and local levels in cattle experimentally infected with MmmSC, for a better understanding of the protective immune mechanisms against the disease. The disease was experimentally reproduced in zebu cattle by contact. Clinical signs, postmortem and microbiological findings were used to evaluate the degree of infection. Serum and bronchial lavage fluids (BAL) were collected sequentially, before contact and over a period of one year after contact. The kinetics of the different antibody isotypes to MmmSC was established. Based on the severity of the clinical signs, post mortem and microbiological findings, the animals were classified into three groups as acute form with deaths, sub-acute to chronic form and resistant animals. Seroconversion was never observed for the control animals throughout the duration of the experiment, nor for those classified as resistant. Instead, seroconversion was measured for all other cattle either with acute or sub-acute to chronic forms of the disease. For these animals, IgM, IgG1, IgG2 and IgA responses were detected in the serum and BAL samples. The kinetics of the IgM, IgG1 and IgG2 responses was nearly similar between both groups of animals. No evident correlation could thus be established between the levels of these isotypes and the severity of the disease. Levels of IgA were high in both BAL and serum samples of animals with sub-acute to chronic forms of the disease, and tended to persist throughout the entire experimental period. In contrast, animals with acute forms of the disease showed low levels of IgA in their BAL samples with none or very transient but low levels of IgA in the serum samples. Our results thus demonstrated that IgA is produced locally in MmmSC experimentally infected cattle by contact and may play a role in protection against contagious bovine pleuropneumonia

Theoretical Studies of the Chemical Reactivity of a Series of Coumarin Derivatives by the Density Functional Theory

The global descriptors of reactivity such as HOMO and LUMO energies, chemical hardness, electrophilicity, softness and dipole moment are theoretically determined for five coumarin derivatives in this paper. The analysis of the determined descriptors allows us to classify the studied molecules according to their reactivities. Thus, compound M3 is qualified to be the most reactive and the least stable with 3.933 eV as its gap energy ΔEgap. It is at the same time the softest, the best electron donor, the most electrophilic and the most polar molecule. The study of thermodynamic parameters shows that all the reactions of formation of studied coumarin derivatives are exothermic and spontaneous with less disorder. Furthermore, Hirschfield population analysis was carried out in order to locate the reactive sites, that are assumed to be the electrophilic and nucleophilic sites of the molecules. It appears that all the reactive sites are located on carbon atoms except those of molecule M3 which are located on oxygen atoms. Compounds M1 and M2 have the same electrophilic site (C15) and the same nucleophilic site (C13) thereby showing that the methyl group does not have any influence on the reactive site. The electrophilic site of the molecule M3 is located on both the identical oxygen atoms O33 and O34 while its nucleophilic site is located on the oxygen atoms O12. The electrophilic sites of compound M4 and M5 are the same and it is located on carbon atom(C11) while the nucleophilic site is located on carbon atom C23 for molecule M4. Concerning the nucleophilic sites of molecule M5 it is located on carbon atom C20. The difference nucleophilic reactive site may be due to the conjugation of activity of both fluorine atom and methyl group on the M5

Efficacy of chloroquine, amodiaquine and sulphadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria: revisiting molecular markers in an area of emerging AQ and SP resistance in Mali

<p>Abstract</p> <p>Background</p> <p>To update the National Malaria Control Programme of Mali on the efficacy of chloroquine, amodiaquine and sulphadoxine-pyrimethamine in the treatment of uncomplicated <it>falciparum </it>malaria.</p> <p>Methods</p> <p>During the malaria transmission seasons of 2002 and 2003, 455 children – between six and 59 months of age, with uncomplicated malaria in Kolle, Mali, were randomly assigned to one of three treatment arms. <it>In vivo </it>outcomes were assessed using WHO standard protocols. Genotyping of <it>msp1</it>, <it>msp2 </it>and CA1 polymorphisms were used to distinguish reinfection from recrudescent parasites (molecular correction).</p> <p>Results</p> <p>Day 28 adequate clinical and parasitological responses (ACPR) were 14.1%, 62.3% and 88.9% in 2002 and 18.2%, 60% and 85.2% in 2003 for chloroquine, amodiaquine and sulphadoxine-pyrimethamine, respectively. After molecular correction, ACPRs (cACPR) were 63.2%, 88.5% and 98.0% in 2002 and 75.5%, 85.2% and 96.6% in 2003 for CQ, AQ and SP, respectively. Amodiaquine was the most effective on fever. Amodiaquine therapy selected molecular markers for chloroquine resistance, while in the sulphadoxine-pyrimethamine arm the level of <it>dhfr </it>triple mutant and <it>dhfr</it>/<it>dhps </it>quadruple mutant increased from 31.5% and 3.8% in 2002 to 42.9% and 8.9% in 2003, respectively. No infection with <it>dhps </it>540E was found.</p> <p>Conclusion</p> <p>In this study, treatment with sulphadoxine-pyrimethamine emerged as the most efficacious on uncomplicated falciparum malaria followed by amodiaquine. The study demonstrated that sulphadoxine-pyrimethamine and amodiaquine were appropriate partner drugs that could be associated with artemisinin derivatives in an artemisinin-based combination therapy.</p

INHIBITION DE SCLEROTIUM ROLFSII SACC. (CORTICIACEAE), AGENT CAUSAL DE LA POURRITURE DU COLLET DE LA TIGE DE LA TOMATE (SOLANACEAE), PAR XYLOPIA AETHIOPICA (DUNAL) A. RICH (ANNONACEAE) ET TRICHODERMA SP.

Tomato (Solanum esculentum Mill) is one of the most consumed in the world with a production of 124 million tons of vegetables. However, the growth of this culture runs into constraints to plant health. To find alternatives to synthetic fungicides which represent the means of control used by most gardeners, a study was conducted on the extracts (essential oils and powders of fruits and leaves) of Xylopia aethiopica (Dunal) A . Rich. (Annonaceae) and two synthetic fungicides (Banko-plus and mancozebe) to test their antifungal potency of Sclerotium rolfsii. Fifteen isolates of Trichoderma sp. are also used for quality antibiotic and fertilizer for crops. At the end of the in vitro tests, it was revealed that the essential oil of fruits was higher than the other extracts on mycelial growth of Sclerotium rolfsii inhibition rate. Four isolates with the best attitudes to mycelial growth were used for in vivo testing. After in vivo assays, the essential oil of fruits and the 9th isolate of Trichoderma harzianum showed a good return on the growth parameters of tomato. The powdered fruit of Xylopia aethiopica also showed a good response to the incidence of the disease. The impact of the higher disease was 10.66 for the fruit powder and 5.96 for the essential oil of the fruit. This study offers the possibility of using essential oils and powdered fruit of Xylopia aethiopica in strategies to control Sclerotium rolfsii

EFFETS DU LIT ET DE LA DENSITÉ DE PLANTATION SUR LA CROISSANCE VÉGÉTATIVE DE L’ANANAS (ANANAS COMOSUS L., VAR. MD2) DANS LA LOCALITÉ DE DABOU EN CÔTE D’IVOIRE

The aim of this study was to identify the best planting bed and density for vegetative growth of Ananas comosus L. var. MD2 plants in the locality of Dabou in Côte d’Ivoire. The effects of three planting beds : flat land, ridge without polyethylene film and ridge covered with polyethylene film ; and two planting densities : 50,000 and 70,000 plants/ha (D50 and D70, respectively) were tested through a split-plot disposition. At the end of the vegetative phase of the cycle, growth parameters were evaluated. The results showed that D70, average heights apical bunches were higher (91.52 cm) than D50 (86.87 cm). The number of fresh leaves varied between 48 and 51. The ridge covered with polyethylene film was distinguished with a number of relatively larger fresh leaves. The follow-up of the D leaves biomass revealed that seven months, the value of 70 g required to trigger floral induction therapy (FIT) had been reached in all plants, whatever planting bed and density. The flat land - density 70,000 plants/ha combinaison was illustrated with the D leaves biomass the highest (80.20 g). The weight of the fruit beingrelated to the plant’s growth during the floral induction therapy, at the end of the vegetative phase, the results could contribute to improving the production of MD2 pineapple in locality of Dabou