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1.  Occurrence of Eimeria Species Parasites on Small-Scale Commercial Chicken Farms in Africa and Indication of Economic Profitability 
PLoS ONE  2013;8(12):e84254.
Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.
PMCID: PMC3877271  PMID: 24391923
2.  Household concentrations and exposure of children to particulate matter from biomass fuels in The Gambia 
Environmental science & technology  2012;46(6):3519-3527.
Particulate matter (PM) is an important metric for studying the health effects of household air pollution. There are limited data on PM exposure for children in homes that use biomass fuels, and no previous study has used direct measurement of personal exposure in children younger than 5 years of age. We estimated PM2.5 exposure for 1,266 children in The Gambia by applying the cookhouse PM2.5-CO relationship to the child’s CO exposure. Using this indirect method, mean PM2.5 exposure for all subjects was 135 ± 38 μg/m3; 25% of children had exposures of 151 μg/m3 or higher. Indirectly-estimated exposure was highest among children who lived in homes that used firewood (collected or purchased) as their main fuel (144 μg/m3) compared to those who used charcoal (85 μg/m3). To validate the indirect method, we also directly measured PM2.5 exposure on 31 children. Mean exposure for this validation dataset was 65 ± 41 μg/m3 using actual measurement and 125 ± 54 μg/m3 using the indirect method based on CO exposure. The correlation coefficient between direct measurements and indirect estimates was 0.01. Children in The Gambia have relatively high PM2.5 exposure. There is a need for simple methods that can directly measure PM2.5 exposure in field studies.
PMCID: PMC3309066  PMID: 22304223
Indoor air pollution; biomass fuels; child survival; global health; Africa; particulate matter; exposure assessment; statistical model
3.  PAR6B is required for tight junction formation and activated PKCζ localization in breast cancer 
Dysregulation of mechanisms that govern the control of epithelial cell polarity, morphology and plasticity are emerging as key processes in tumor progression. In this study we report amplification and overexpression of PAR6B, an essential component in epithelial cell tight junction (TJ) formation and maintenance of apico-basal polarity, in breast cancer cell lines. Analysis of chromosome 20q13.13 in 11 breast cancer cell lines by fluorescence in situ hybridization (FISH) identified a novel small amplicon centered at PARD6B in 5 cell lines, with copy number ranging from 7 to 27. The presence of the PARD6B amplicon correlated with PARD6B transcript and PAR6B protein abundance. Expression of related isoforms PARD6A and PARD6G were detectable at significantly lower levels. PARD6B overexpression correlated with TJ network formation in cultured cell monolayers. SiRNA-mediated inhibition of PAR6B in MCF7 resulted in loss of TJ assembly and membrane localization of atypical PKCζ (aPKC), but did not affect adherens junction formation. SiRNA-mediated inhibition of CDC42 in MCF7 also resulted in loss of TJ networks, confirming the requirement of a complete PAR6-aPKC-CDC42-PAR3 complex to activate and stabilize TJs. Immunohistochemical analysis of PAR6B expression on breast tumor microarrays indicated exquisite epithelial cell-specificity. Few quantitative differences in staining were observed between normal epithelium and adjacent tumor margins. However staining appeared reduced and cytoplasmic in more poorly differentiated tumors. We propose that quantitative imbalances in the components of pathways governing normal epithelial cell polarity arising from gain or loss of function may radically alter epithelial cell architecture and contribute to tumor progression.
PMCID: PMC3433109  PMID: 22957302
Breast Cancer; DNA amplification; tight junction; siRNA; polarity; adhesion; PARD6B; PAR6B; CDC42; PKCζ

Results 1-3 (3)