89 research outputs found

    Amélioration de la valeur nutritionnelle des gousses de Piliostigma reticulatum (D. C.) Hochst dans l’alimentation du bétail en période de soudure

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    Dans la zone nord soudanienne du Burkina Faso, les gousses de Piliostigma reticulatum sont intensément utilisées pendant la saison sèche comme aliment d’appoint pour le bétail. L’objectif de cette étudeest d’améliorer la qualité nutritionnelle de ces gousses pour optimiser leur apport. Neuf rations comprenant chacune des gousses de P. reticulatum (70 p.100) et du foin de Pennisetum pedicellatum (30 p.100) distribuéesà raison de 50 g MS/kg p0,75 ont été testées sur des ovins de race Djallonké. Les gousses ont subi différents traitements physiques (concassage, mouture) suivis ou non de traitement à l’urée auxquelles est associé dans certains cas du charbon de bambou à des doses de 0,25 ou 0,50 g/kg PV dans le but d’influencer l’action des tanins. L’utilisation de l’urée a entraîné, quelle que soit la forme de distribution, une amélioration de la digestibilité, surtout celle des matières azotées en raison de l’augmentation significative de leur teneur. L’adjonction du charbon de bambou n’a amélioré la digestibilité des gousses non traitées à l’urée qu’à la dose de 0,50 g/kg PV. Par contre, sur des gousses traitées à l’urée, il a permis une amélioration significative (

    Structural evaluation of roll quality and in-roll stress analysis using a novel on-line measurement technique

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    In a previous paper (Jaafar et al., 1999) we reported on the rudimentary development of a new technique for the on-line measurement of a roll's coefficient of restitution (Cr) as it is being wound, and enunciated the theoretical underpinnings behind the development. In this paper, the Cr sensor has been used to evaluate the radial and tangential roll behavior as it is being built. Based on the experimental findings, numerical simulations are proposed for modeling, using energy-based formulations, radial modulus and tangential stress as a function of roll radius. The simulations take into account the additive effect of winding operations, and corrects for the use of such idealized set-ups as the stack experiment, first proposed by Pfeiffer (1966), by incorporating increasing number of layers.In addition to basic structural assessment of roll quality in real time, a set of experiments have been devised to garner a fundamental understanding of the in-roll stress variations, based on which new insight into the constitutive relations is presented

    CONTRIBUTION DE LA TECHNOLOGIE DU BIODIGESTEUR A LA DURABILITE DES EXPLOITATIONS AGRICOLES FAMILIALES AU BURKINA FASO

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    Despite problems related to energy, biomass reduction, grazing degradation, decreased soil fertility, environmental fragility, the biodigester is positioned as a strategy of adaptation and transformation of production systems with the association of agriculture and livestock. The biodigester is an underground construction that uses cow dung or pork excrement mixed with water to produce biogas for cooking and lighting and effluent compost for soil fertilization. The study aimed to evaluate the contribution of the Biodigester technology to agro-ecological sustainability, socio-territorial sustainability and socio-economic sustainability. The study was undertaken in November 2015 in the municipalities of Bobo Dioulasso, Kaya-Barsalgo and Dori. The individual survey was conducted in twenty-four (24) villages on a sample of 166 heads of farms. The results showed the contribution of biodigester technology to agro-ecological, socio-territorial and socio-economic sustainability. Furthermore, land security, the cost of installing the infrastructure, insufficiency or scarcity of cow dung at certain times of the year, lack of water remain the main limits of adoption of the Biodigester technology. The biodigester is an appropriate technology capable of solving the economic, agricultural and energy questions faced by households

    β-Elemene Piperazine Derivatives Induce Apoptosis in Human Leukemia Cells through Downregulation of c-FLIP and Generation of ROS

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    β-Elemene is an active component of the herb medicine Curcuma Wenyujin with reported antitumor activity. To improve its antitumor ability, five novel piperazine derivatives of β-elemene, 13-(3-methyl-1-piperazinyl)-β-elemene (DX1), 13-(cis-3,5-dimethyl-1-piperazinyl)-β-elemene (DX2), 13-(4-ethyl-1-piperazinyl)-β-elemene (DX3), 13-(4-isopropyl-1-piperazinyl)-β-elemene (DX4) and 13-piperazinyl-β-elemene (DX5), were synthesized. The antiproliferative and apoptotic effects of these derivatives were determined in human leukemia HL-60, NB4, K562 and HP100-1 cells. DX1, DX2 and DX5, which contain a secondary amino moiety, were more active in inhibiting cell growth and in inducing apoptosis than DX3 and DX4. The apoptosis induction ability of DX1 was associated with the generation of hydrogen peroxide (H2O2), a decrease of mitochondrial membrane potential (MMP), and the activation of caspase-8. Pretreatment with the antioxidants N-acetylcysteine and catalase completely blocked DX1-induced H2O2 production, but only partially its activation of caspase-8 and induction of apoptosis. HL-60 cells were more sensitive than its H2O2-resistant subclone HP100-1 cells to DX1-induced apoptosis. The activation of caspase-8 by these compounds was correlated with the decrease in the levels of cellular FLICE-inhibitory protein (c-FLIP). The proteasome inhibitor MG-132 augmented the decrease in c-FLIP levels and apoptosis induced by these derivatives. FADD- and caspase-8-deficient Jurkat subclones have a decreased response to DX1-induced apoptosis. Our data indicate that these novel β-elemene piperazine derivatives induce apoptosis through the decrease in c-FLIP levels and the production of H2O2 which leads to activation of both death receptor- and mitochondrial-mediated apoptotic pathways

    Predictors of linkage to care following community-based HIV counseling and testing in rural Kenya

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    Despite innovations in HIV counseling and testing (HCT), important gaps remain in understanding linkage to care. We followed a cohort diagnosed with HIV through a community-based HCT campaign that trained persons living with HIV/AIDS (PLHA) as navigators. Individual, interpersonal, and institutional predictors of linkage were assessed using survival analysis of self-reported time to enrollment. Of 483 persons consenting to follow-up, 305 (63.2%) enrolled in HIV care within 3 months. Proportions linking to care were similar across sexes, barring a sub-sample of men aged 18–25 years who were highly unlikely to enroll. Men were more likely to enroll if they had disclosed to their spouse, and women if they had disclosed to family. Women who anticipated violence or relationship breakup were less likely to link to care. Enrolment rates were significantly higher among participants receiving a PLHA visit, suggesting that a navigator approach may improve linkage from community-based HCT campaigns.Vestergaard Frandse

    Untreated Human Infections by Trypanosoma brucei gambiense Are Not 100% Fatal

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    The final outcome of infection by Trypanosoma brucei gambiense, the main agent of sleeping sickness, has always been considered as invariably fatal. While scarce and old reports have mentioned cases of self-cure in untreated patients, these studies suffered from the lack of accurate diagnostic tools available at that time. Here, using the most specific and sensitive tools available to date, we report on a long-term follow-up (15 years) of a cohort of 50 human African trypanosomiasis (HAT) patients from the Ivory Coast among whom 11 refused treatment after their initial diagnosis. In 10 out of 11 subjects who continued to refuse treatment despite repeated visits, parasite clearance was observed using both microscopy and polymerase chain reaction (PCR). Most of these subjects (7/10) also displayed decreasing serological responses, becoming progressively negative to trypanosome variable antigens (LiTat 1.3, 1.5 and 1.6). Hence, in addition to the “classic” lethal outcome of HAT, we show that alternative natural progressions of HAT may occur: progression to an apparently aparasitaemic and asymptomatic infection associated with strong long-lasting serological responses and progression to an apparently spontaneous resolution of infection (with negative results in parasitological tests and PCR) associated with a progressive drop in antibody titres as observed in treated cases. While this study does not precisely estimate the frequency of the alternative courses for this infection, it is noteworthy that in the field national control programs encounter a significant proportion of subjects displaying positive serologic test results but negative results in parasitological testing. These findings demonstrate that a number of these subjects display such infection courses. From our point of view, recognising that trypanotolerance exists in humans, as is now widely accepted for animals, is a major step forward for future research in the field of HAT

    TNFα Cooperates with IFN-γ to Repress Bcl-xL Expression to Sensitize Metastatic Colon Carcinoma Cells to TRAIL-mediated Apoptosis

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    BACKGROUND: TNF-related apoptosis-inducing ligand (TRAIL) is an immune effector molecule that functions as a selective anti-tumor agent. However, tumor cells, especially metastatic tumor cells often exhibit a TRAIL-resistant phenotype, which is currently a major impediment in TRAIL therapy. The aim of this study is to investigate the synergistic effect of TNFα and IFN-γ in sensitizing metastatic colon carcinoma cells to TRAIL-mediated apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: The efficacy and underlying molecular mechanism of cooperation between TNFα and IFN-γ in sensitizing metastatic colon carcinoma cells to TRAIL-mediated apoptosis were examined. The functional significance of TNFα- and IFN-γ-producing T lymphocyte immunotherapy in combination with TRAIL therapy in suppression of colon carcinoma metastasis was determined in an experimental metastasis mouse model. We observed that TNFα or IFN-γ alone exhibits minimal sensitization effects, but effectively sensitized metastatic colon carcinoma cells to TRAIL-induced apoptosis when used in combination. TNFα and IFN-γ cooperate to repress Bcl-xL expression, whereas TNFα represses Survivin expression in the metastatic colon carcinoma cells. Silencing Bcl-xL expression significantly increased the metastatic colon carcinoma cell sensitivity to TRAIL-induced apoptosis. Conversely, overexpression of Bcl-xL significantly decreased the tumor cell sensitivity to TRAIL-induced apoptosis. Furthermore, TNFα and IFN-γ also synergistically enhanced TRAIL-induced caspase-8 activation. TNFα and IFN-γ was up-regulated in activated primary and tumor-specific T cells. TRAIL was expressed in tumor-infiltrating immune cells in vivo, and in tumor-specific cytotoxic T lymphocytes (CTL) ex vivo. Consequently, TRAIL therapy in combination with TNFα/IFN-γ-producing CTL adoptive transfer immunotherapy effectively suppressed colon carcinoma metastasis in vivo. CONCLUSIONS/SIGNIFICANCE: TNFα and IFN-γ cooperate to overcome TRAIL resistance at least partially through enhancing caspase 8 activation and repressing Bcl-xL expression. Combined CTL immunotherapy and TRAIL therapy hold great promise for further development for the treatment of metastatic colorectal cancer

    Global Retinoblastoma Presentation and Analysis by National Income Level

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- A nd middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
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