Methods of preparation and nutritional evaluation of dishes consumed in a malaria endemic zone in Cameroon (Ngali II)

This study deals with the description of the methods of preparation and determination of the nutritional potential of dishes consumed by Cameroonians living in a rural area, which is a malaria endemic zone, called Ngali II. The dishes consumed are prepared from leguminous seeds, seeds of the Cucurbitaceae family (egusi seeds), green leafy vegetables, tubers, cereals unripe bananas and plantains. The contents in moisture, ash, proteins, lipids, crude fibres and carbohydrates were determined by standard AOAC methods. The results obtained are expressed in percentage f.w for moisture and percentage d.w for ash, proteins, lipids, crude fibres and carbohydrates. The moisture content ranges from 57.77- 6.17; ash, 0.66-14.74; proteins, 1.49-37.25; lipids, 0.26-54.98; crude fibres, 1.43-17.82 and carbohydrates, 3.51-95.76. This study revealed that a higher consumption of dishes made from leguminous seeds, egusi seeds, green leafy vegetables, and low consumption of tubers, unripe bananas and plantains will lead to a good nutritional balance.African Journal of Biotechnology Vol. 4 (3), pp. 273-278, 200

A pooled testing strategy for identifying SARS-CoV-2 at low prevalence

Suppressing infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will probably require the rapid identification and isolation of individuals infected with the virus on an ongoing basis. Reverse-transcription polymerase chain reaction (RT-PCR) tests are accurate but costly, which makes the regular testing of every individual expensive. These costs are a challenge for all countries around the world, but particularly for low-to-middle-income countries. Cost reductions can be achieved by pooling (or combining) subsamples and testing them in groups1-7. A balance must be struck between increasing the group size and retaining test sensitivity, as sample dilution increases the likelihood of false-negative test results for individuals with a low viral load in the sampled region at the time of the test8. Similarly, minimizing the number of tests to reduce costs must be balanced against minimizing the time that testing takes, to reduce the spread of the infection. Here we propose an algorithm for pooling subsamples based on the geometry of a hypercube that, at low prevalence, accurately identifies individuals infected with SARS-CoV-2 in a small number of tests and few rounds of testing. We discuss the optimal group size and explain why, given the highly infectious nature of the disease, largely parallel searches are preferred. We report proof-of-concept experiments in which a positive subsample was detected even when diluted 100-fold with negative subsamples (compared with 30-48-fold dilutions described in previous studies9-11). We quantify the loss of sensitivity due to dilution and discuss how it may be mitigated by the frequent re-testing of groups, for example. With the use of these methods, the cost of mass testing could be reduced by a large factor. At low prevalence, the costs decrease in rough proportion to the prevalence. Field trials of our approach are under way in Rwanda and South Africa. The use of group testing on a massive scale to monitor infection rates closely and continually in a population, along with the rapid and effective isolation of people with SARS-CoV-2 infections, provides a promising pathway towards the long-term control of coronavirus disease 2019 (COVID-19).info:eu-repo/semantics/publishe

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

Genomic sequencing of SARS-CoV-2 in Rwanda reveals the importance of incoming travelers on lineage diversity

COVID-19 transmission rates are often linked to locally circulating strains of SARS-CoV-2. Here we describe 203 SARS-CoV-2 whole genome sequences analyzed from strains circulating in Rwanda from May 2020 to February 2021. In particular, we report a shift in variant distribution towards the emerging sub-lineage A.23.1 that is currently dominating. Furthermore, we report the detection of the first Rwandan cases of the B.1.1.7 and B.1.351 variants of concern among incoming travelers tested at Kigali International Airport. To assess the importance of viral introductions from neighboring countries and local transmission, we exploit available individual travel history metadata to inform spatio-temporal phylogeographic inference, enabling us to take into account infections from unsampled locations. We uncover an important role of neighboring countries in seeding introductions into Rwanda, including those from which no genomic sequences were available. Our results highlight the importance of systematic genomic surveillance and regional collaborations for a durable response towards combating COVID-19.info:eu-repo/semantics/publishe

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

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Characterization of Novel Genes Involved in Neurogenesis in Xenopus

Der Südafrikanische Krallenfrosch Xenopus laevis ist ein gutes System für das Studium der Neurogenese in Vertebraten. Bereits früh, im offenen Neuralplattenstadium, wird das Gebiet der primären Neuronen durch eine Gruppe von neuralen Genen definiert, die in einem typischen Muster in Form von Streifen exprimiert werden und die drei bilaterale Zellgruppen definieren, aus denen jeweils Motorneuronen, Interneuronen und sensorische Neuronen hervorgehen. Eine Untergruppe enthält Gene, deren Expressionsmuster dem von N-tubulin, einem neuronalen Differenzierungsmarker, entspricht. Diese Untergruppe wird aufgrund der Beobachtung, dass Mitglieder dieser Gruppe bei der Differenzierung von primären Neuronen eine Funktion besitzen, als N-tubulin Synexpressionsgruppe bezeichnet. Eine andere Untergruppe, die als Delta Synexpressionsgruppe bezeichnet wird, beinhaltet Gene, deren Expressionsmuster dem von X-Delta-1 ähnelt. Mitglieder dieser Gruppe regulieren die lokalen Zell-Zell-Interaktionen, im Zusammenhang mit der primären Neurogenese bekannt als laterale Hemmung. Insgesamt sind solche Expressionsmuster ein wertvolles Kriterium für die Suche nach neuen Genen, die bei der primären Neurogenese eine Funktion besitzen. Wir haben 500 Klone aus einer Xenopus Schwanzknospenstadium Kopf cDNA Bank durch Verwendung einer systematischen Expressionsmusteranalyse untersucht. Aus der Fülle der neural exprimierten Gene werden fünf in Form von Streifen exprimiert. Drei dieser Gene sind in Xenopus bisher nicht beschrieben worden. Diese beeinhalten XPak3, eine Serin/Threonin Proteinkinase, und X-Mxi1, ein basisches Helix-Loop-Helix Leucin Zipper Protein, die beide zur N-tubulin Synexpressionsgruppe gehören, sowie XSeb4, ein RRM-Typ RNA bindendes Protein, das zur Delta Synexpressionsgruppe gehört. Basierend auf der Tatsache, dass XPak3 und XSeb4 regulatorische Moleküle mit unbekannter Funktion bei der Neurogenese definieren, wurde ihre funktionelle Charakterisierung durchgeführt. Durch Mikroinjektionsexperimente in Embryonen wurde gefunden, dass XPak3 und XSeb4 auf Transkriptionsebene durch den proneuralen Faktor X-Neurogenin related-1 (X-Ngnr-1) aktiviert und durch laterale Hemmung reprimiert wurden. Eine vergleichende Expressionsmusteranalyse zeigte, dass XPak3, aber nicht XPak1 und XPak2, eine neuronal exprimierte XPak Isoform ist. Interessanterweise induzierte die Überexpression einer konstitutiv aktiven Form von XPak3, XPak3-myr, vorzeitige neuronale Differenzierung, ein Phänotyp, der mit der Induktion von Zellzyklusarretierung korreliert. Umgekehrt blockierte der XPak3 Funktionsverlust, der durch Verwendung eines Morpholino-antisense-Oligonukleotids erzeugt wurde, die Bildung von primären Neuronen und induzierte eine gesteigerte Zellproliferation. Diese Hemmung der Neurogenese wurde durch Koinjektion von XPak3-myr wieder aufgehoben. Schlussfolgernd schlagen wir vor, dass XPak3 von Neurogenin induziert wird, um die Mitose neuronal programmierter Zellen zu inhibieren und so deren Differenzierung zu erlauben. Ektopische Expression hoher Konzentrationen (>150 pg) von XSeb4 hemmt die Bildung primärer Neuronen. Unerwarteterweise führte die Unterdrückung der XSeb4 Expression durch die Verwendung eines Morpholino-antisense-Oligonukleotids ebenfalls zur Hemmung der Neurogenese. Die Mikroinjektion niedriger Konzentrationen von XSeb4 mRNA zeigte keinen Effekt auf die Expression von N-tubulin. Diese widersprüchlichen Befunde erfordern weitere systematische Untersuchungen