Absence of Tec family kinases interleukin-2 inducible T cell kinase (Itk) and Bruton's tyrosine kinase (Btk) severely impairs Fc epsilonRI-dependent mast cell responses

Mast cells are critical effector cells in the pathophysiology of allergic asthma and other IgE-mediated diseases. The Tec family of tyrosine kinases Itk and Btk serve as critical signal amplifiers downstream of antigen receptors. Although both kinases are expressed and activated in mast cells following FcεRI stimulation, their individual contributions are not clear. To determine whether these kinases play unique and/or complementary roles in FcεRI signaling and mast cell function, we generated Itk and Btk double knock-out mice. Analyses of these mice show decreased mast cell granularity and impaired passive systemic anaphylaxis responses. This impaired response is accompanied by a significant elevation in serum IgE in Itk/Btk double knock-out mice. In vitro analyses of bone marrow-derived mast cells (BMMCs) indicated that Itk/Btk double knock-out BMMCs are defective in degranulation and cytokine secretion responses downstream to FcεRI activation. These responses were accompanied by a significant reduction in PLCγ2 phosphorylation and severely impaired calcium responses in these cells. This defect also results in altered NFAT1 nuclear localization in double knock-out BMMCs. Network analysis suggests that although they may share substrates, Itk plays both positive and negative roles, while Btk primarily plays a positive role in mast cell FcεRI-induced cytokine secretion.     

Effect of contraceptives on the prevalence of vaginal colonization with Candida species in Edo State, Nigeria

High vaginal swabs (HVS) obtained from 500 volunteers in Edo State, Nigeria which comprised 394 contraceptive users and 106 non-contraceptive users were screened for the prevalence of Candida species using standard procedures. Results revealed the isolation of Candida species in 246 of volunteers. These included Candida albicans 174 (38.4%), Candida pseudotropicalis 20 (4%), Candida stellatoidea 15 (3%), Candida krusei nine (1.8%), Candida guilliermondii 12 (2.4%), Candida tropicalis 11 (2.2%) and Candida glabrata five (1%). Of the 394 contraceptive users, 203 (51.5%) had Candida species isolated from them compared to 43 (40.6%) from 106 non-contraceptive users. There was significant relationship (P<0.001) between the type of contraceptive used and the prevalence of vaginal colonization. Age and marital status of the volunteers sampled had significant relationship (P<0.001) with the prevalence of vaginal colonization. Results have revealed an association between use of contraceptive and the prevalence of vaginal colonization in our environment.     

Comparison of the performance of horizontal and vertical flow constructed wetland planted with Rhynchospora corymbosa

Treatment performance of horizontal flow (HF) and vertical flow (VF) constructed wetland planted with Rhynchospora corymbosa were compared. The average porosity of the CW beds were 0.55, hydraulic retention time (HRT) of 3?days, hydraulic loading rate (HLR) and Organic Loading rate were 0.058?m/day and 3.96 (g·BOD/m²·day), respectively with a volumetric flow rate of 0.14 m³/day. The pollutant concentration of graywater before and after its introduction to the CWs was measured using standard sampling and analyses methods. The mean removal efficiencies (RE) for HF and VF CWs were BOD, 35% and 35.4%; COD, 61.9% and 56.7%; TN, 87% and 92%; TP, 95% and 65%; TSS, 86% and 59.6%; pH, 8.8% and 12.8%, respectively. The graywater was highly contaminated in terms of nutrient and organic load. The mean values of the parameters tested for different CWs were significantly different (P?≤?0.05). This comparative study favored HF over VF Constructed wetland with HF found to be a viable alternative for graywater treatment for organics, nutrients and suspended solids removal. The result provided insight into the performance of CWs planted with R. corymbosa.     

Benzoylbenzimidazole-based selective inhibitors targeting Cryptosporidium parvum and Toxoplasma gondii calcium-dependent protein kinase-1

Calcium-dependent protein kinase-1 (CDPK1) from Cryptosporidium parvum (CpCDPK1) and Toxoplasma gondii (TgCDPK1) have become attractive targets for discovering selective inhibitors to combat infections caused by these protozoa. We used structure-based design to improve a series of benzoylbenzimidazole-based compounds in terms of solubility, selectivity, and potency against CpCDPK1 and TgCDPK1. The best inhibitors show inhibitory potencies below 50nM and selectivity well above 200-fold over two human kinases with small gatekeeper residues.     

Continent-wide releases of neotropical phytoseiids against the exotic cassava green mite in Africa

Since the initiation of the classical biological control campaign by the International Institute of Tropical Agriculture to control the exotic mite, Mononychellus tanajoa, 11 species (18 distinct populations) of neotropical phytoseiids have been selected and shipped to Africa for experimental releases. Initially, natural enemies were selected because of their abundance and frequency on cassava. Between 1984 and 1988, more than 5.2 million phytoseiids belonging to 7 species of Colombian origin were imported to Africa and released in 348 sites in 10 countries. None of these species and populations ever became established in the wide range of agronomic and ecological conditions tested, apparently because of inadequate alternative food sources when M. tanajoa densities were low and extended periods of low relative humidity. Foreign exploration was adjusted in 1988 to focus on Neotropical regions that were agrometeorologically homologous to areas in Africa where the potential for severe M. tanajoa damage exists. Natural enemies associated temporally and spatially with M. tanajoa and capable of surviving periods of low M. tanajoa densities on alternative food sources in the new exploration sites were given selection priority. Several natural enemy candidates were immediately identified in Northeast Brazil and shipped to Africa. Approximately 1.9 million phytoseiids of the species Neoseiulus idaeus and Typhlodromalus limonicus of Brazilian origin were released in 133 sites in 6 countries in 1989 and 1990. N. idaeus has since become established in Benin, while T. limonicus may be established in Benin, Burundi, and Ghana.     

Computational Biology and Bioinformatics in Nigeria

Over the past few decades, major advances in the field of molecular biology, coupled with advances in genomic technologies, have led to an explosive growth in the biological data generated by the scientific community. The critical need to process and analyze such a deluge of data and turn it into useful knowledge has caused bioinformatics to gain prominence and importance. Bioinformatics is an interdisciplinary research area that applies techniques, methodologies, and tools in computer and information science to solve biological problems. In Nigeria, bioinformatics has recently played a vital role in the advancement of biological sciences. As a developing country, the importance of bioinformatics is rapidly gaining acceptance, and bioinformatics groups comprised of biologists, computer scientists, and computer engineers are being constituted at Nigerian universities and research institutes. In this article, we present an overview of bioinformatics education and research in Nigeria. We also discuss professional societies and academic and research institutions that play central roles in advancing the discipline in Nigeria. Finally, we propose strategies that can bolster bioinformatics education and support from policy makers in Nigeria, with potential positive implications for other developing countries.     

Evolution of <Emphasis Type="Italic">Salmonella</Emphasis> nomenclature: a critical note

Salmonellae are widely distributed but nomenclaturally controversial pathogens of both humans and animals. Despite elaborate studies, much still remain to be discovered about these organisms. Although Salmonella nomenclature has proved to be rather complex, in 2005, Salmonella enterica finally gained official approval as the type species of the genus Salmonella. In addition, one other species has been approved and recognised in the genus Salmonella, namely, Salmonella bongori. New serovars (serotypes) are continually being discovered each year and reported in the journal Research in Microbiology. Salmonella serovars and their antigenic formulae are listed in the White–Kauffmann–Le Minor scheme and updated by the World Health Organization’s Collaborating Centre for Reference and Research on Salmonella at the Pasteur Institute, Paris, France.