Health Implications of Occupational Exposure of Butchers to Emissions from Burning Tyres

Background: Flames from burning scrap tyres are used in de-furring animals for human consumption in most parts of Nigeria. Emissions from tyres are known to contain a myriad of toxic mixtures especially particulate matter (PM), volatile organic compounds, hazardous air pollutants, and inspirable metals, some of which are known human carcinogens. This cross-sectional study investigated the deleterious health effects of these emissions in occupationally-exposed workers at the Dei-Dei Abattoir, Abuja, Nigeria. Methods: A total of 156 respondents were divided into two groups. Group 1 (124 butchers) and group 2 [32 administrative staff (AS)]. Data from digital spirometry were used to determine the association between chronic exposure to tyre emissions and lung function. Urinary 1-Hydroxypyrene concentration, phenolic compounds levels and heavy metal concentrations were determined. Also ambient PM and polycyclic aromatic hydrocarbons (PAHs) concentrations at 3 delineated points in the abattoir were measured. Findings: Spirometry results showed significant deterioration of lung function in the butchers. The concentration of 1-Hydroxypyrene (μg/molCret) in the post-shift urine samples of the butchers was significantly higher (P < 0.05) in butchers relative to the AS (0.52 ± 0.13 Vs 0.20 ± 0.07, respectively). Similarly the concentrations of zinc and nickel (mg/l) were significantly higher in the butchers compared to the AS (zinc: 0.91 ± 0.19 Vs 0.31 ± 0.28, respectively; nickel: 0.11 ± 0.06 Vs 0.06 ± 0.02, respectively). Anthracene, fluoranthene, pyrene, benzo-a- pyrene, and PM concentrations were significantly higher at the de-furring point when compared to the wash bay and the administrative building, especially between 8.00 and 8.30 am. Conclusion: Occupational exposure to scrap tyre emissions resulted in significant adverse health effects. The existing laws banning the use of burning tyres in meat processing should be enforced while the use of personal protective equipment should be encouraged in abattoirs

Investigation into the Nephrotoxicity of Nigerian Bonny Light Crude Oil in Albino Rats

Abstract: The effect of bonny-light crude oil was assessed in adult albino rats. The rats were administered with 200, 400, and 800mg/kg body weight of the crude oil orally for 7 days. Fluid intake was measured daily, initial and final animal body was recorded. The toxic effects on the kidneys were assessed and histological studies carried out. The results revealed that the kidney cells were damaged; crude oil caused a destruction of the renal reserve capacity. There was a significant increase (p ≤ 0.05) in creatinine in the high dose group (800mg/kg), and a significant decrease (p ≤ 0.05) in urea concentration. Histological examination indicates that crude oil induced severe pathologic changes in the forms of necrosis and oedema

Population structure of the malaria vector Anopheles moucheti in the equatorial forest region of Africa

<p>Abstract</p> <p>Background</p> <p><it>Anopheles moucheti </it>is a major malaria vector in forested areas of Africa. However, despite its important epidemiological role, it remains poorly known and insufficiently studied. Here, levels of genetic differentiation were estimated between different <it>A. moucheti </it>populations sampled throughout its distribution range in Central Africa.</p> <p>Methods</p> <p>Polymorphism at ten microsatellite markers was compared in mosquitoes sampled in Cameroon, the Democratic Republic of Congo and an island on Lake Victoria in Uganda. Microsatellite data were used to estimate genetic diversity within populations, their relative long-term effective population size, and the level of genetic differentiation between them.</p> <p>Results</p> <p>All specimens collected in Tsakalakuku (Democratic Republic of Congo) were identified as <it>A. m. bervoetsi </it>while other samples consisted of <it>A. m. moucheti</it>. Successful amplification was obtained at all microsatellite loci within all <it>A. m. moucheti </it>samples while only six loci amplified in <it>A. m. bervoetsi</it>. Allelic richness and heterozygosity were high for all populations except the island population of Uganda and <it>A. m. bervoetsi</it>. High levels of genetic differentiation were recorded between <it>A. m. bervoetsi </it>and each <it>A. m. moucheti </it>sample as well as between the island population of <it>A. m. moucheti </it>and mainland populations. Significant isolation by distance was evidenced between mainland populations.</p> <p>Conclusion</p> <p>High levels of genetic differentiation supports complete speciation of <it>A. m. bervoetsi </it>which should henceforth be recognized as a full species and named <it>A. bervoetsi</it>. Isolation by distance is the main force driving differentiation between mainland populations of <it>A. m. moucheti</it>. Genetically and geographically isolated populations exist on Lake Victoria islands, which might serve as relevant field sites for evaluation of innovative vector control strategies.</p

Do ethnobotanical and laboratory data predict clinical safety and efficacy of anti-malarial plants?

<p>Abstract</p> <p>Background</p> <p>Over 1200 plant species are reported in ethnobotanical studies for the treatment of malaria and fevers, so it is important to prioritize plants for further development of anti-malarials.</p> <p>Methods</p> <p>The “RITAM score” was designed to combine information from systematic literature searches of published ethnobotanical studies and laboratory pharmacological studies of efficacy and safety, in order to prioritize plants for further research. It was evaluated by correlating it with the results of clinical trials.</p> <p>Results and discussion</p> <p>The laboratory efficacy score correlated with clinical parasite clearance (r_s=0.7). The ethnobotanical component correlated weakly with clinical symptom clearance but not with parasite clearance. The safety component was difficult to validate as all plants entering clinical trials were generally considered safe, so there was no clinical data on toxic plants.</p> <p>Conclusion</p> <p>The RITAM score (especially the efficacy and safety components) can be used as part of the selection process for prioritising plants for further research as anti-malarial drug candidates. The validation in this study was limited by the very small number of available clinical studies, and the heterogeneity of patients included.</p

Natural products as starting points for future anti-malarial therapies: going back to our roots?

Abstract Background The discovery and development of new anti-malarials are at a crossroads. Fixed dose artemisinin combination therapy is now being used to treat a hundred million children each year, with a cost as low as 30 cents per child, with cure rates of over 95%. However, as with all anti-infective strategies, this triumph brings with it the seeds of its own downfall, the emergence of resistance. It takes ten years to develop a new medicine. New classes of medicines to combat malaria, as a result of infection by Plasmodium falciparum and Plasmodium vivax are urgently needed. Results Natural product scaffolds have been the basis of the majority of current anti-malarial medicines. Molecules such as quinine, lapachol and artemisinin were originally isolated from herbal medicinal products. After improvement with medicinal chemistry and formulation technologies, and combination with other active ingredients, they now make up the current armamentarium of medicines. In recent years advances in screening technologies have allowed testing of millions of compounds from pharmaceutical diversity for anti-malarial activity in cellular assays. These initiatives have resulted in thousands of new sub-micromolar active compounds – starting points for new drug discovery programmes. Against this backdrop, the paucity of potent natural products identified has been disappointing. Now is a good time to reflect on the current approach to screening herbal medicinal products and suggest revisions. Nearly sixty years ago, the Chinese doctor Chen Guofu, suggested natural products should be approached by dao-xing-ni-shi or ‘acting in the reversed order’, starting with observational clinical studies. Natural products based on herbal remedies are in use in the community, and have the potential unique advantage that clinical observational data exist, or can be generated. The first step should be the confirmation and definition of the clinical activity of herbal medicinal products already used by the community. This first step forms a solid basis of observations, before moving to in vivo pharmacological characterization and ultimately identifying the active ingredient. A large part of the population uses herbal medicinal products despite limited numbers of well-controlled clinical studies. Increased awareness by the regulators and public health bodies of the need for safety information on herbal medicinal products also lends support to obtaining more clinical data on such products. Conclusions The relative paucity of new herbal medicinal product scaffolds active against malaria results discovered in recent years suggest it is time to re-evaluate the ‘smash and grab’ approach of randomly testing purified natural products and replace it with a patient-data led approach. This will require a change of perspective form many in the field. It will require an investment in standardisation in several areas, including: the ethnopharmacology and design and reporting of clinical observation studies, systems for characterizing anti-malarial activity of patient plasma samples ex vivo followed by chemical and pharmacological characterisation of extracts from promising sources. Such work falls outside of the core mandate of the product development partnerships, such as MMV, and so will require additional support. This call is timely, given the strong interest from researchers in disease endemic countries to support the research arm of a malaria eradication agenda. Para-national institutions such as the African Network for Drugs and Diagnostics Innovation (ANDi) will play a major role in facilitating the development of their natural products patrimony and possibly clinical best practice to bring forward new therapeutics. As in the past, with quinine, lapinone and artemisinin, once the activity of herbal medicinal products in humans is characterised, it can be used to identify new molecular scaffolds which will form the basis of the next generation of anti-malarial therapies.</p

In vivo antiplasmodial activity of ZS-2A: a fraction from chloroform extract of Zizyphus spina-christi root bark against Plasmodium berghei berghei in mice

Zizyphus spina-christi is used in ethnomedical practice for the treatment of fever. Bio-assay guided investigation of the plant's root bark was initiated and ZS-2A, a fraction from the chloroform extract of the material, eluted with hexane-ethylacetate (50:50) using flash column chromatography, was evaluated for in vivo antiplasmodial activity against Plasmodium berghei in mice. Four-day suppressive, curative effect against established infection and prophylactic models of antiplasmodial studies were used. The fraction (25, 50 and 100 mg/kg, p.o.) showed a potent activity against the parasite in the suppressive and curative tests. The result suggests that ZS-2A may be a promising agent for malaria treatment. Keywords: Fraction ZS-2A, Zizyphus spina-christi, Plasmodium berghei berghei. International Journal of Biological and Chemical Sciences Vol. 1 (3) 2007: pp. 281-28

La durée du cycle gonotrophique d'Anopheles moucheti varie de trois à quatre jours en fonction de la proximité par rapport aux gites de ponte

La durée du cycle gonotrophique d'#Anopheles moucheti, a été précisée dans le village forestier d'Ebogo en bordure du fleuve Nyong. D'ordinaire c'est un vecteur secondaire de paludisme mais localement, comme à Ebogo, c'est le vecteur principal qui assure même une transmission pendant toute l'année. Les phases du cycle gonotrophique sont les suivantes. - La phase 1 (entre la ponte et le repas de sang) dure une dizaine d'heures pour les femelles qui prennent leur repas de sang à proximité du gîte de ponte. Elle dure de 24 à 36 heures pour les femelles qui prennent leur repas de sang à quelques kilomètres du gîte de ponte. - La phase 2 (digestion et maturation ovarienne) dure de 48 à 52 heures. L'absence de dissociation gonotrophique suggère qu'il n'existe pas de phase prégravide pour les nullipares. - La phase 3 (entre la fin de la maturation et la ponte) dure une douzaine d'heures. Au total le cycle gonotrophique dure 3 jours pour les #An. moucheti qui prennent leur repas de sang à proximité (moins d'un kilomètre) du gîte de ponte. Il dure 4 jours pour les #An. moucheti$ qui doivent parcourir de 3,5 à 5 kilomètres du gîte de ponte. (Résumé d'auteur

La durée du cycle gonotrophique d'Anopheles moucheti varie de trois à quatre jours en fonction de la proximité par rapport aux gites de ponte

La durée du cycle gonotrophique d'#Anopheles moucheti, a été précisée dans le village forestier d'Ebogo en bordure du fleuve Nyong. D'ordinaire c'est un vecteur secondaire de paludisme mais localement, comme à Ebogo, c'est le vecteur principal qui assure même une transmission pendant toute l'année. Les phases du cycle gonotrophique sont les suivantes. - La phase 1 (entre la ponte et le repas de sang) dure une dizaine d'heures pour les femelles qui prennent leur repas de sang à proximité du gîte de ponte. Elle dure de 24 à 36 heures pour les femelles qui prennent leur repas de sang à quelques kilomètres du gîte de ponte. - La phase 2 (digestion et maturation ovarienne) dure de 48 à 52 heures. L'absence de dissociation gonotrophique suggère qu'il n'existe pas de phase prégravide pour les nullipares. - La phase 3 (entre la fin de la maturation et la ponte) dure une douzaine d'heures. Au total le cycle gonotrophique dure 3 jours pour les #An. moucheti qui prennent leur repas de sang à proximité (moins d'un kilomètre) du gîte de ponte. Il dure 4 jours pour les #An. moucheti$ qui doivent parcourir de 3,5 à 5 kilomètres du gîte de ponte. (Résumé d'auteur