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Search Results: 1 - 10 of 13084 matches for " EL Abongwa "
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Environmental factors affecting malaria parasite prevalence in rural Bolifamba, South- West Cameroon
T Nkuo-Akenji, NN Ntonifor, MB Ndukum, HK Kimbi, EL Abongwa, A Nkwescheu, DN Anong, M Songmbe, MG Boyo, KN Ndamukong, VP Titanji
African Journal of Health Sciences , 2006,
Abstract: The impact of some environmental factors on malaria parasite prevalence was investigated in rural Bolifamba, Cameroon. The study population comprised 1454 subjects aged 0 – 65 years. Malaria parasite prevalence was higher in the rainy (50.1%) than in the dry season (44.2%) with a significant difference (P=0.001) in mean parasite density between seasons. Individuals <15 years old, had significantly higher malaria parasite prevalence (55.5%) than those >15 years (37.4%). Malaria parasite prevalence (P=0.001) and parasite density (P=0.03) were higher in the individuals of wooden plank houses than those of cement brick houses. Inhabitants of houses surrounded by bushes or garbage heaps and swamps or stagnant water showed higher malaria parasite prevalence and densities compared with those from cleaner surroundings. Anopheles gambiae (63.8%) and A. funestus (32.8%) were associated with perennial transmission of malaria. Our data indicates that poor environmental sanitation and housing conditions may be significant risk factors for malaria parasite burden in Bolifamba. African Journal of Health Sciences Vol. 13 (1-2) 2008: pp. 20-26
Selective activity of extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi
Fidelis Cho-Ngwa, Melanie Abongwa, Moses N Ngemenya, Kennedy D Nyongbela
BMC Complementary and Alternative Medicine , 2010, DOI: 10.1186/1472-6882-10-62
Abstract: Sixteen crude extracts were prepared from various parts of M. discoidea and H. africanum using different organic solvents. The filaricidal activities were determined in vitro. Cytotoxicity of the active extracts was assessed on monkey kidney epithelial cells in vitro and the selectivity indices (SI) of the extracts determined. Acute toxicity of the promising extracts was investigated in mice.Four out of the 16 extracts showed microfilaricidal activity based on motility reduction, whereas, none showed macrofilaricidal activity based on the MTT/formazan assay. The methylene chloride extract of H. africanum leaves (HLC) recorded the lowest IC50 of 31.25 μg/mL and an IC100 of 62.5 μg/mL. The SI for the active extracts ranged from 0.5 - 2.63. No form of acute toxicity was observed in mice. Phytochemical analysis revealed the presence of anthraquinones, sterols and terpenoids in the promising extracts.The non-polar extracts of M. discoidea and H. africanum are potential sources of new microfilaricidal lead compounds, and the results support their use in traditional medicine.Onchocerciasis is a parasitic disease of man caused by the filarial worm, Onchocerca volvulus, and is transmitted by the black fly, Simulium damnosum [1]. It remains a major public health problem with over 37 million patients and a risk population of over 120 million [2]. Chemotherapy remains the main method of control of onchocerciasis. Ivermectin being the only drug currently recommended for treatment of the disease effectively kills the microfilariae of O. volvulus, but not the adult worms (macrofilariae) which may live for up to 18 years in humans [3]. Also, the emergence of ivermectin resistance in parasitic nematodes of veterinary importance [4] raises serious concerns that this may extend to the human O. volvulus. Therefore, the search for new and highly efficacious filaricides is imperative.Medicinal plant preparations have been identified as alternative remedies for several diseases [5]. About
Investigation of Acetylcholine Receptor Diversity in a Nematode Parasite Leads to Characterization of Tribendimidine- and Derquantel-Sensitive nAChRs
Samuel K. Buxton equal contributor,Claude L. Charvet equal contributor,Cedric Neveu,Jacques Cabaret,Jacques Cortet,Nicolas Peineau,Melanie Abongwa,Elise Courtot,Alan P. Robertson,Richard J. Martin
PLOS Pathogens , 2014, DOI: doi/10.1371/journal.ppat.1003870
Abstract: Nicotinic acetylcholine receptors (nAChRs) of parasitic nematodes are required for body movement and are targets of important “classical” anthelmintics like levamisole and pyrantel, as well as “novel” anthelmintics like tribendimidine and derquantel. Four biophysical subtypes of nAChR have been observed electrophysiologically in body muscle of the nematode parasite Oesophagostomum dentatum, but their molecular basis was not understood. Additionally, loss of one of these subtypes (G 35 pS) was found to be associated with levamisole resistance. In the present study, we identified and expressed in Xenopus oocytes, four O. dentatum nAChR subunit genes, Ode-unc-38, Ode-unc-63, Ode-unc-29 and Ode-acr-8, to explore the origin of the receptor diversity. When different combinations of subunits were injected in Xenopus oocytes, we reconstituted and characterized four pharmacologically different types of nAChRs with different sensitivities to the cholinergic anthelmintics. Moreover, we demonstrate that the receptor diversity may be affected by the stoichiometric arrangement of the subunits. We show, for the first time, different combinations of subunits from a parasitic nematode that make up receptors sensitive to tribendimidine and derquantel. In addition, we report that the recombinant levamisole-sensitive receptor made up of Ode-UNC-29, Ode-UNC-63, Ode-UNC-38 and Ode-ACR-8 subunits has the same single-channel conductance, 35 pS and 2.4 ms mean open-time properties, as the levamisole-AChR (G35) subtype previously identified in vivo. These data highlight the flexible arrangements of the receptor subunits and their effects on sensitivity and resistance to the cholinergic anthelmintics; pyrantel, tribendimidine and/or derquantel may still be effective on levamisole-resistant worms.
Outcome Evaluation of Early Implementation of Option B+ in Cameroon: A Prospective Cohort Observational Survey in the Northwest and Southwest Regions  [PDF]
Pius Tih Muffih, Edouard Katayi Tshimwanga, Andrew Abutu, Lem Edith Abongwa, Jacques Chirac Awa, Pascal Nji Atanga, Felix Desembuin, Eveline Mboh Khan, Kuni Esther Bonje, Nshom Emmanuel, Ebeny Francois Temgbait Chimoun, Thomas Welty, Gladys Tayong Fosah, Jennifer Lim, Dana Duncan, Leah Petit, Gilbert Tene, Jembia Mosoko, Omotayo Bolu
World Journal of AIDS (WJA) , 2018, DOI: 10.4236/wja.2018.83008
Abstract: Background: Mother to child transmission (MTCT) of HIV constitutes a major source of new pediatric infections in Cameroon. Objective: The aim of this implementation research was to assess outcomes and effectiveness of providing life-long antiretroviral therapy (ART) for HIV-positive pregnant and breastfeeding women (Option B+). Methods: From October 2013 to July 2014, HIV-positive pregnant and breastfeeding women, not on antiretroviral (ARV) prophylaxis and ART, were recruited from 22 purposefully selected health facilities in the Northwest and Southwest regions for a prospective, observational cohort evaluation. Option B+ was offered to participants and outcome indicators were measured. Results: Out of 680 women eligible for this assessment, 669 (98%) were initiated on Option B+. Retention-in-care was 90% (95% CI, 87.85 - 92.61) and 79% (95% CI, 75.20 - 81.88), and loss to follow up (LTFU) was 7% (95% CI: 4.95 -
Effect of the Number and Orientation of Fractures on the P-Wave Velocity Diminution: Application on the Building Stones of the Rabat Area (Morocco)  [PDF]
Hamid El Azhari, Iz-Eddine El Amrani El Hassani
Geomaterials (GM) , 2013, DOI: 10.4236/gm.2013.33010
Abstract: This study is focused on two types of Moroccan rocks, among the most widely used as building stones: the calcarenite of Salé (CS) and the marble of oued Akrech (MA). The two rocks, lithologically different, show a clear contrast of their P-wave velocities (Vp): 3.90 vs 5.10 km/s at dry state and 4.29 vs 5.64 km/s at saturation. The “Artificial fractures” created in the two rock types reveal that their Vp undergo diminutions which the rates vary depending of the number and the plane orientation of the fractures. In the CS, Vp shows an increasing of cumulative diminution (Dc) according to the number of fractures, but with a variable rate of unitary diminution (Du) from one fracture to the other. This defines a linear regression with a low coefficient of determination (Dc = 10.18NbFr + 10.96; r2 = 0.87). The mode of the Vp evolution would be related to the roughness of fractures surface, which itself depends upon the petrographic nature of the calcarenite (friable structure, high porosity and heterogenous composition). The MA manifested an increasing Dc with a fairly constant rate of Du from a fracture to another, giving a regression line with a high coefficient of determination (Dc = 12.17NbFr10.69; r2 = 0.99). This steady diminution of Vp would be related to the granoblastic texture and the monomineral composition of the marble, which engender smoother fracture surfaces. The rates of Vp diminution also depend on the orientation plane of the fractures relative to the direction of wave propagation. The fractures parallel (θ = 0°) amplify slightly the Vp, playing a significant role of “waveguide”. The fractures oriented at 45° lead to a diminution lower than those of fractures oriented at 25° and 90°. The same trend of diminution, but at variable rates, appears on the samples of the two types of stones at dry and saturated state. This can be explained by the compressive nature of P-waves, which obey the physic laws of the transmission of the constraints in the solid mediums.
Waterlogging in the New Reclaimed Areas Northeast El Fayoum, Western Desert, Egypt, Reasons and Solutions  [PDF]
El Sayed Ali El Abd, Maged Mostafa El Osta
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.618147
Abstract: The waterlogging in the new reclaimed areas has become a major concern in the area Northeast El Fayoum, Western Desert, Egypt. It is not only endangering the structures and properties but also causing major environmental problem affecting the health of the area, habitats, and the biotic of the land community, as well as the deteriorating of Egypt’s Pharaonic monuments (El Lahun and Hawarah pyramids). Both the daily seepage from excess irrigation water and the presence of impervious clay or limestone beds at shallow depths may represent the main contributor of ground-water rising in the shallow aquifer. This paper investigates the interplay of the hydrogeological characteristics, soil properties and recent land reclamation projects on the distribution of waterlogging and salinization within the study area. The field observations show that new reclaimed areas have been recently cultivated in distant areas from the old agricultural land. These new cultivations have developed widespread waterlogging, soil salinization and deterioration of Egypt’s Pharaonic monuments as a result of rising groundwater related problems. In this paper, the data used come from database of drillings for eleven observation wells distributed inside the whole area to measure periodic water levels. The soil litho-units are mainly composed of coarse sand, sandy clay, silt and fractured limestone underlined by impervious clay or limestone, thus limiting the downward percolation of excess irrigation water and therefore develops waterlogging. The drainage networks and suitable irrigation methods have to be considered when planning for a new cultivation in dry land to better control waterlogging and salinization hazard. It is highly recommended in this research that newly small and deep cut drainage canals network should be constructed and connected to the master drainage canal to dewater the excess irrigation water and to prevent the waterlogging in the concerned area.
On Elliptic Problem with Singular Cylindrical Potential, a Concave Term, and Critical Caffarelli-Kohn-Nirenberg Exponent  [PDF]
Mohammed El Mokhtar Ould El Mokhtar
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.611166
Abstract: In this paper, we establish the existence of at least four distinct solutions to an elliptic problem with singular cylindrical potential, a concave term, and critical Caffarelli-Kohn-Nirenberg exponent, by using the Nehari manifold and mountain pass theorem.
Four Nontrivial Solutions for Kirchhoff Problems with Critical Potential, Critical Exponent and a Concave Term  [PDF]
Mohammed El Mokhtar Ould El Mokhtar
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.614198
Abstract: In this paper, we consider the existence of multiple solutions to the Kirchhoff problems with critical potential, critical exponent and a concave term. Our main tools are the Nehari manifold and mountain pass theorem.
Anterior Screw Fixation in Type II Odontoid Fractures: Keys for Better Outcome in Early Experience in Developing Countries  [PDF]
Ahmed El Fiki, Hisham El Shitany
Open Journal of Modern Neurosurgery (OJMN) , 2018, DOI: 10.4236/ojmn.2018.84031
Abstract: Introduction: Representing up to 15% of cervical injuries, odontoid type II fractures may cause spinal cord compression through atlanto-axial instability. Anterior screw fixation provides direct fracture site stability, high fusion rate and most importantly keeping cervical spine move free. We will highlight success keys in early experience for better outcome. Methods: We operated ten cases with traumatic type II odontoid fractures in neurotrauma unit, Cairo University hospitals from March 2015 till June 2017. Six males and four females were included. Preoperative MRI and dynamic CT were among the assessment criteria. Uni-planner fluoroscopy was used. Results: No post-operative deficit appeared. One screw was inserted in all cases. Immediate and 6 weeks later CT cervical spine showed stable reduced fracture site. Conclusions: Anterior odontoid screw fixation done with prior good selection of the patient and fracture shape is an effective motion preserving surgical option for type II odontoid fractures. Limited resources shouldn’t prevent starting experience especially in developing countries, but larger studies are needed.
Effect of Urbanization and Industrialization Processes on Outdoor Thermal Human Comfort in Egypt  [PDF]
El-Sayed ROBAA
Atmospheric and Climate Sciences (ACS) , 2011, DOI: 10.4236/acs.2011.13012
Abstract: Detailed studies on the effect of urbanization and industrialization processes on outdoor thermal human com- fort in Greater Cairo region, Egypt have been performed in this study. Four different districts in Greater Cairo region have been selected to represent rural, suburban, typical urban and industrial areas. The data of surface dry, wet bulb temperatures and wind speed for two different periods represent non-urbanized and urbanized periods have been used. Discomfort indices for the two periods have been calculated for the four districts. The study revealed that urbanization and industrialization processes have resulted in the distinctly modification of human comfortable at all districts. The feeling of quite comfortable reduced from the old non-urbanized period to the recent urbanized period at the four districts. During the recent urbanized period, the rural area has the highest total number of quite comfortable hours while both urban and industrial areas have the lowest total number of hours. The serious hot uncomfortable didn’t occur at all districts during the old non-urbanized period while during the recent urbanized period, all people had felt extreme serious hot uncomfortable only at urban and industrial areas. It could be concluded that the urbanization and industriali-zation processes cause increase of human serious hot uncomfortable feeling which in turn leads to more hin-dering for the human activities while the rural conditions leads to optimum weather comfort for further and more human activities.
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