156 research outputs found

    Caractérisations physico-chimiques des eaux souterraines de la localité de Yamtenga (Burkina Faso)

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    Dans la localité de Yamtenga au Burkina Faso, les eaux souterraines constituent les ressources hydriques primordiales pour l’alimentation en eau de boisson de la population rurale et pour l’irrigation des terres agricoles. Ce travail visait à étudier la qualité physico-chimique des eaux de forages et de puits de cette localité. Pour y parvenir, des prélèvements d’eau, au niveau de onze forages et puits, ont été effectués au cours de quatre séances de prélèvement à Yamtenga (Novembre 2010 à Octobre 2011). Différents paramètres physico-chimiques ont été mesurés :  température, pH, conductivité électrique, indice de Ryznar, turbidité, dureté. Les ions majeurs (Na+, K+, Ca2+, Mg2+, HCO3-, NO3-, SO4 2-, Cl-) ont été dosés par différentes méthodes dont la spectrométrie d’absorption atomique à flamme et la colorimétrie. Les éléments traces métalliques (ETMs) tels que : Fe2+, Mn2+, Tl+, Cu2+ et Zn2+ ont été dosés par des méthodes voltamétriques à redissolution. Les résultats ont montré que certains points d’eau ne sont pas conseillés à la  consommation comme eau de boisson. Les paramètres qui déclassent ces eaux souterraines comme eau de boisson sont le fer, le manganèse et le thallium. Les eaux souterraines de Yamtenga sont classées bicarbonatées calciques et magnésiennes pour tous les ouvrages échantillonnés.Mots clés : Yamtenga, eaux souterraines, analyses physico-chimiques, éléments traces métallique

    Simian immunodeficiency virus infection in wild-caught chimpanzees from Cameroon

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    Simian immunodeficiency viruses (SIVcpz) infecting chimpanzees (Pan troglodytes) in west central Africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([HIV-1]; groups M, N and O), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of SIVcpz still remains limited. In this study, we tested 71 wild-caught chimpanzees from Cameroon for evidence of SIVcpz infection. Thirty-nine of these were of the central subspecies (Pan troglodytes troglodytes), and 32 were of the Nigerian subspecies (Pan troglodytes vellerosus), as determined by mitochondrial DNA analysis. Serological analysis determined that one P. t. troglodytes ape (CAM13) harbored serum antibodies that cross-reacted strongly with HIV-1 antigens; all other apes were seronegative. To characterize the newly identified virus, 14 partially overlapping viral fragments were amplified from fecal virion RNA and concatenated to yield a complete SIVcpz genome (9,284 bp). Phylogenetic analyses revealed that SIVcpzCAM13 fell well within the radiation of the SIVcpzPtt group of viruses, as part of a clade including all other SIVcpzPtt strains as well as HIV-1 groups M and N. However, SIVcpzCAM13 clustered most closely with SIVcpzGAB1 from Gabon rather than with SIVcpzCAM3 and SIVcpzCAM5 from Cameroon, indicating the existence of divergent SIVcpzPtt lineages within the same geographic region. These data, together with evidence of recombination among ancestral SIVcpzPtt lineages, indicate long-standing endemic infection of central chimpanzees and reaffirm a west central African origin of HIV-1. Whether P. t. vellerosus apes are naturally infected with SIVcpz requires further study

    Diagnostic trials: a field guide

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    The Diagnostic Trials, conducted in Kenya, Malawi, Mali, Nigeria, and Tanzania, constitute a major part of Africa Soil Information Service agronomic activities. This guide provides a standard tool that is part of a structured approach for the diagnosis of soil health related constraints to crop production. It is intended for use by national and international agricultural research systems, development partners and extension services to ensure standard procedures in data collection that will feed to an Africa-wide database of diagnostic trials, allowing an increase in data density over time and an improvement of the reliability in the assessment of soil constraints and inferences

    HIV-1 group O infection in Cameroon, 1986 to 1998.

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    We report a survey of HIV-1 group O infection in Cameroon during 1986 to 1998. The prevalence of HIV-1/O decreased from 0.6% to 0.4%, while HIV-1/M increased from 19.2% to 31.5% from 1994 to 1998. We concluded that HIV-1/O infection is stable in Cameroon and may be declining slightly

    DEVENIR DES MACRO-AMPUTES TRAUMATIQUES DU MEMBRE THORACIQUE : CAS D’UN PAYS EN DEVELOPPEMENT

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    Major upper limb trauma are rare lesions that management should be done in a specialized center. Faced with complex trauma of the upper limb, the orthopedist wonders if everything must be done to maintain a sometimes very functional upper limb amputated. We report the case of three male patients aged 18, 26 and 30 years of crash victims of upper limb accidents from the public road and work. The dominant member was diagnosed in a patient. Two patients underwent arm amputation stump and regularization forearm was performed in the third. Infection of amputation stump with surgery to stabilize, was recorded in a patient. One had a prosthesis made on the spot with his socio-professional reintegration, other patients are waiting

    Primary Malignant Musculosqueletal Tumors of Members in Adult in Togo

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    Abstract Purpose: Primary malignant musculosqueletal tumors in adult are rare affections group and its treatment is still a real challenge today. The aim of this work was to describe the epidemiologic and treatment aspects of these tumors in the national reference center of our country. Materiel and Methods: It was a retrospective review of primary malignant musculosqueletal tumors treated in orthopedics and trauma unit of Sylvanus Olympio teaching hospital of Lomé, Togo from January 2000 to December 2014. Results: During the study period, 28 cases were selected and reviewed. There were 17 men (60.71%) and 11 women (39.29%). The average age was 32.7 years. There were 20 cases (71%) of primary malignant bone tumors (PMBT) and 8 cases (29%) of primary malignant soft tissues tumors (PMSTT). There were 6 (30%) of osteosarcoma. The tumor was located in the bones of the forearm and wrist/hand in 2 (10%) patients for each anatomical site; for the lower limb, around knee in 7 (35%) patients. Eight patients had PMSTT (28, 57%). There were three cases of rhabdomyosarcoma, 2 cases of fibrosarcoma. Tumors were located around knee in 4 cases and around ankle/foot in 3 cases. In the two groups of tumor, tumor resection was performed in 5 patients (17.86%) and limb amputation indicated in 23 patients (82.14%), was performed in 15 (53.57%) and 8 patients (37.78%), rejected it and left hospital against medical advice. Conclusion: Malignant musculoskeletal tumors are relatively rare in Togo. Their treatment is based on radical surgery which is often not supervised by adjuvant therapies. Ignorance, poverty of the population and embryonic state of diagnostic and treatment infrastructures are the obstacles to their care. Education and awareness must be integrated to care and fight against this group of diseases

    Cell-free (RNA) and cell-associated (DNA) HIV-1 and postnatal transmission through breastfeeding

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    <p>Introduction - Transmission through breastfeeding remains important for mother-to-child transmission (MTCT) in resource-limited settings. We quantify the relationship between cell-free (RNA) and cell-associated (DNA) shedding of HIV-1 virus in breastmilk and the risk of postnatal HIV-1 transmission in the first 6 months postpartum.</p> <p>Materials and Methods - Thirty-six HIV-positive mothers who transmitted HIV-1 by breastfeeding were matched to 36 non-transmitting HIV-1 infected mothers in a case-control study nested in a cohort of HIV-infected women. RNA and DNA were quantified in the same breastmilk sample taken at 6 weeks and 6 months. Cox regression analysis assessed the association between cell-free and cell-associated virus levels and risk of postnatal HIV-1 transmission.</p> <p>Results - There were higher median levels of cell-free than cell-associated HIV-1 virus (per ml) in breastmilk at 6 weeks and 6 months. Multivariably, adjusting for antenatal CD4 count and maternal plasma viral load, at 6 weeks, each 10-fold increase in cell-free or cell-associated levels (per ml) was significantly associated with HIV-1 transmission but stronger for cell-associated than cell-free levels [2.47 (95% CI 1.33–4.59) vs. aHR 1.52 (95% CI, 1.17–1.96), respectively]. At 6 months, cell-free and cell-associated levels (per ml) in breastmilk remained significantly associated with HIV-1 transmission but was stronger for cell-free than cell-associated levels [aHR 2.53 (95% CI 1.64–3.92) vs. 1.73 (95% CI 0.94–3.19), respectively].</p> <p>Conclusions - The findings suggest that cell-associated virus level (per ml) is more important for early postpartum HIV-1 transmission (at 6 weeks) than cell-free virus. As cell-associated virus levels have been consistently detected in breastmilk despite antiretroviral therapy, this highlights a potential challenge for resource-limited settings to achieve the UNAIDS goal for 2015 of eliminating vertical transmission. More studies would further knowledge on mechanisms of HIV-1 transmission and help develop more effective drugs during lactation.</p&gt

    Conserved presence of G-quadruplex forming sequences in the Long Terminal Repeat Promoter of Lentiviruses

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    G-quadruplexes (G4s) are secondary structures of nucleic acids that epigenetically regulate cellular processes. In the human immunodeficiency lentivirus 1 (HIV-1), dynamic G4s are located in the unique viral LTR promoter. Folding of HIV-1 LTR G4s inhibits viral transcription; stabilization by G4 ligands intensifies this effect. Cellular proteins modulate viral transcription by inducing/unfolding LTR G4s. We here expanded our investigation on the presence of LTR G4s to all lentiviruses. G4s in the 5'-LTR U3 region were completely conserved in primate lentiviruses. A G4 was also present in a cattle-infecting lentivirus. All other non-primate lentiviruses displayed hints of less stable G4s. In primate lentiviruses, the possibility to fold into G4s was highly conserved among strains. LTR G4 sequences were very similar among phylogenetically related primate viruses, while they increasingly differed in viruses that diverged early from a common ancestor. A strong correlation between primate lentivirus LTR G4s and Sp1/NF\u3baB binding sites was found. All LTR G4s folded: their complexity was assessed by polymerase stop assay. Our data support a role of the lentiviruses 5'-LTR G4 region as control centre of viral transcription, where folding/unfolding of G4s and multiple recruitment of factors based on both sequence and structure may take place

    Genetic diversity of simian lentivirus in wild De Brazza’s monkeys (Cercopithecus neglectus) in Equatorial Africa

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    De Brazza’s monkeys (Cercopithecus neglectus) are non-human primates (NHP) living in Equatorial Africa from South Cameroon through the Congo-Basin to Uganda. As most of the NHP living in sub-Saharan Africa, they are naturally infected with their own simian lentivirus, SIVdeb. Previous studies confirmed this infection for De Brazza’s from East Cameroon and Uganda. In this report, we studied the genetic diversity of SIVdeb in De Brazza’s monkeys from different geographical areas in South Cameroon and from the Democratic Republic of Congo (DRC). SIVdeb strains from east, central and western equatorial Africa form a species-specific monophyletic lineage. Phylogeographic clustering was observed among SIVdeb strains from Cameroon, the DRC and Uganda, but also among primates from distinct areas in Cameroon. These observations suggest a longstanding virus–host co-evolution. SIVdeb prevalence is high in wild De Brazza’s populations and thus represents a current risk for humans exposed to these primates in central Africa
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