71 research outputs found
Identification and characterization of novel binding partners of the Lef/Tcf Transcription Factors
Insertion/deletion gene variants of angiotensin converting enzyme do not predispose cameroonians of the Bantu ethnic group to essential hypertension
The insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene has been reported to be implicated in the predisposition to essential hypertension (EH). This association may depend on ethnic and genetic backgrounds. The objective of this study was to determine if the possible I/D polymorphism in the Bantu ethnic group of Cameroon is associated with EH. Data were analyzed from 60 patients and 50 healthy controls in order to access the risk factors of EH in this ethnic group. Comparison of gene and allele frequency distributions between the two populations revealed that systolic and diastolic blood pressures, age, family history and lack of physical exercise were risk factors of EH in this ethnic group. Comparison of means of age, systolic and diastolic blood pressures as well as the proportions of individuals with a family history of EH and lack of physical exercise were higher in the hypertensive than the normotensive group (p < 0.05). In addition, Comparison of genotype and allele frequencies between the two populations did not reveal statistically significant differences (p > 0.05). Moreover, analyses of relationship between ACE I/D gene variants and EH did not reveal any association (p > 0.05). Consistently, the two groups also did not present with differences in I and D allele distribution (p > 0.05). These results suggest that EH is not associated with ACE I/D polymorphism.© 2016 International Formulae Group. All rights reserved.Keywords: ACE, Gene polymorphism, SWR, Cameroo
Isolation and molecular identification of Salmonella with high multidrug resistance to first line typhoid antibiotics in Southwest Cameroon
Background:The prevalence of typhoid fever in Cameroon is high. However, studies on susceptibility of Salmonella to the recommended antibiotics are few and not extensive. This study investigated the susceptibility of Salmonella isolated from clinical specimens in the South West region of Cameroon and the genes responsible for their antibiotic resistance. Methods: Salmonellawas isolated from clinical specimens collected from some medical laboratories in the study area by culture on Salmonella Shigella agar. Identification and resistance genes analysis were done using biochemical tests, PCR and gene sequencing. Disc diffusion test was done using 11 commercial antibiotics and minimum inhibitory concentrations determined by microdilution test to assess antibiotic susceptibility profile. The Multi-Antibiotic Resistance (MAR) index values were calculated. Results: Salmonella was isolated from 50 out of 115 specimens, of which 46 (92 %) were multidrug resistant (MDR) with MAR indices > 0.2.The MDR isolates showed high resistance to penicillins and low resistance to ciprofloxacin. PCR revealed that antibiotic resistance was largely due to the tem-1, Sul 1, dfrA1, floR genes. Sequencing revealed double mutations at codons 83 (Ser83-Phe) and 87 (Asp87-Gly) and one mutation at codon 83 (Ser83-Trp) in the quinolone resistance determining regions of the gyrA gene in two isolates. Conclusion: This study has revealed presence of MDR Salmonella enterica isolates in Southwest Cameroon with several resistance genes. This finding will guide use of antibiotics in treatment of Salmonella infections in the study area and justifies the search for new efficacious antibacterials against the MDR strains
A single bat species in Cameroon harbors multiple highly divergent papillomaviruses in stool identified by metagenomics analysis
AbstractA number of PVs have been described in bats but to the best of our knowledge not from feces. Using a previously described NetoVIR protocol, Eidolon helvum pooled fecal samples (Eh) were treated and sequenced by Illumina next generation sequencing technology. Two complete genomes of novel PVs (EhPV2 and EhPV3) and 3 partial sequences (BATPV61, BATPV890a and BATPV890b) were obtained and analysis showed that the EhPV2 and EhPV3 major capsid proteins cluster with and share 60–64% nucleotide identity with that of Rousettus aegyptiacus PV1, thus representing new species of PVs within the genus Psipapillomavirus. The other PVs clustered in different branches of our phylogenetic tree and may potentially represent novel species and/or genera. This points to the vast diversity of PVs in bats and in Eidolon helvum bats in particular, therefore adding support to the current concept that PV evolution is more complex than merely strict PV-host co-evolution
Elevated Plasmodium sporozoite infection and multiple insecticide resistance in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms.
Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a village located 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F1 adult progeny. Bioassays were performed to assess resistance profile to insecticides. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated.
Results: Anopheles funestus s.s. was most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having a similar sporozoite rate. Both species exhibited high levels of resistance to pyrethroids (<40% mortality). An. gambiae s.s. was also resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively. Furthermore, the high pyrethroid/DDT resistances in An. gambiae s.s. corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b.
Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the high Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas
Secondary Metabolites Isolated from Artemisia afra and Artemisia annua and Their Anti-Malarial, Anti-Inflammatory and Immunomodulating Properties—Pharmacokinetics and Pharmacodynamics: A Review
peer reviewedThere are over 500 species of the genus Artemisia in the Asteraceae family distributed over the globe, with varying potentials to treat different ailments. Following the isolation of artemisinin (a potent anti-malarial compound with a sesquiterpene backbone) from Artemisia annua, the phytochemical composition of this species has been of interest over recent decades. Additionally, the number of phytochemical investigations of other species, including those of Artemisia afra in a search for new molecules with pharmacological potentials, has increased in recent years. This has led to the isolation of several compounds from both species, including a majority of monoterpenes, sesquiterpenes, and polyphenols with varying pharmacological activities. This review aims to discuss the most important compounds present in both plant species with anti-malarial properties, anti-inflammatory potentials, and immunomodulating properties, with an emphasis on their pharmacokinetics and pharmacodynamics properties. Additionally, the toxicity of both plants and their anti-malaria properties, including those of other species in the genus Artemisia, is discussed. As such, data were collected via a thorough literature search in web databases, such as ResearchGate, ScienceDirect, Google scholar, PubMed, Phytochemical and Ethnobotanical databases, up to 2022. A distinction was made between compounds involved in a direct anti-plasmodial activity and those expressing anti-inflammatory and immunomodulating activities or anti-fever properties. For pharmacokinetics activities, a distinction was made between compounds influencing bioavailability (CYP effect or P-Glycoprotein effect) and those affecting the stability of pharmacodynamic active components
Experimentação pedagógica - relações CTSA na formação inicial do licenciando em Química
A formação inicial do professor de química é um momento propício a experimentação pedagógica, onde novas metodologias/ enfoques/ teorias podem ser incorporados ao futuro exercício da docência. O presente trabalho visa discutir a experiência de formação de dois licenciandos em química, em seu primeiro estágio supervisionado durante o semestre 2007.1 da Universidade do Estado do Rio Grande do Norte - Brasil. Bem como as propostas de aulas práticas dirigidas por estes com o intuito de desenvolver um enfoque CTSA em seu primeiro contato com a regência de sala. Para a discussão das observações levou-se em conta as impressões de licenciandos para analisar criticamente as contribuições que esta prática efetivamente construíram para a formação dos futuros professores de química, e principalmente sobre as suas visões sobre possibilidades do enfoque CTSA no ensino-aprendizagem
Improving Social Justice in COVID-19 Health Research: Interim guidelines for reporting health equity in observational studies
The COVID-19 pandemic has highlighted the global imperative to address health inequities. Observational studies are a valuable source of evidence for real-world effects and impacts of implementing COVID-19 policies on the redistribution of inequities. We assembled a diverse global multi-disciplinary team to develop interim guidance for improving transparency in reporting health equity in COVID-19 observational studies. We identified 14 areas in the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist that need additional detail to encourage transparent reporting of health equity. We searched for examples of COVID-19 observational studies that analysed and reported health equity analysis across one or more social determinants of health. We engaged with Indigenous stakeholders and others groups experiencing health inequities to co-produce this guidance and to bring an intersectional lens. Taking health equity and social determinants of health into account contributes to the clinical and epidemiological understanding of the disease, identifying specific needs and supporting decision-making processes. Stakeholders are encouraged to consider using this guidance on observational research to help provide evidence to close the inequitable gaps in health outcomes
Computational Design and Preliminary Serological Analysis of a Novel Multi-Epitope Vaccine Candidate Against Onchocerciasis and Related Filarial Diseases
Onchocerciasis is a skin and eye disease that exerts a heavy socio-economic burden, particularly in sub-Saharan Africa, a region which harbours greater than 96% of either infected or at-risk populations. The elimination plan for the disease is currently challenged by many factors including amongst others; the potential emergence of resistance to the main chemotherapeutic agent, ivermectin (IVM). Novel tools, including preventative and therapeutic vaccines, could provide additional impetus to the disease elimination tool portfolio. Several observations in both humans and animals have provided evidence for the development of both natural and artificial acquired immunity. In this study, immuno-informatics tools were applied to design a filarial-conserved multi-epitope subunit vaccine candidate, (designated Ov-DKR-2) consisting of B-and T-lymphocyte epitopes of eight immunogenic antigens previously assessed in pre-clinical studies. The high-percentage conservation of the selected proteins and epitopes predicted in related nematode parasitic species hints that the generated chimera may be instrumental for cross-protection. Bioinformatics analyses were employed for the prediction, refinement, and validation of the 3D structure of the Ov-DKR-2 chimera. In-silico immune simulation projected significantly high levels of IgG1, T-helper, T-cytotoxic cells, INF-γ, and IL-2 responses. Preliminary immunological analyses revealed that the multi-epitope vaccine candidate reacted with antibodies in sera from both onchocerciasis-infected individuals, endemic normals as well as loiasis-infected persons but not with the control sera from European individuals. These results support the premise for further characterisation of the engineered protein as a vaccine candidate for onchocerciasis
Multiple insecticide resistance and Plasmodium infection in the principal malaria vectors Anopheles funestus and Anopheles gambiae in a forested locality close to the Yaoundé airport, Cameroon
Background: Reducing the burden of malaria requires better understanding of vector populations, particularly in forested regions where the incidence remains elevated. Here, we characterized malaria vectors in a locality near the Yaoundé international airport, Cameroon, including species composition, abundance, Plasmodium infection rate, insecticide resistance profiles and underlying resistance mechanisms.
Methods: Blood-fed adult mosquitoes resting indoors were aspirated from houses in April 2019 at Elende, a locality situated 2 km from the Yaoundé-Nsimalen airport. Female mosquitoes were forced to lay eggs to generate F 1 adults. Bioassays were performed to assess resistance profile to the four insecticides classes. The threshold of insecticide susceptibility was defined above 98% mortality rate and mortality rates below 90% were indicative of confirmed insecticide resistance. Furthermore, the molecular basis of resistance and Plasmodium infection rates were investigated.
Results: Anopheles funestus s.s. was the most abundant species in Elende (85%) followed by Anopheles gambiae s.s. (15%) with both having similar sporozoite rate. Both species exhibited high levels of resistance to the pyrethroids, permethrin and deltamethrin (<40% mortality). An. gambiae s.s. was resistant to DDT (9.9% mortality) and bendiocarb (54% mortality) while susceptible to organophosphate. An. funestus s.s. was resistant to dieldrin (1% mortality), DDT (86% mortality) but susceptible to carbamates and organophosphates. The L119F-GSTe2 resistance allele (8%) and G119S ace-1 resistance allele (15%) were detected in An. funestus s.s. and An. gambiae s.s., respectively. Furthermore, the high pyrethroid/DDT resistances in An. gambiae corresponded with an increase frequency of 1014F kdr allele (95%). Transcriptional profiling of candidate cytochrome P450 genes reveals the over-expression of CYP6P5, CYP6P9a and CYP6P9b.
Conclusion: The resistance to multiple insecticide classes observed in these vector populations alongside the significant Plasmodium sporozoite rate highlights the challenges that vector control programs encounter in sustaining the regular benefits of contemporary insecticide-based control interventions in forested areas
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