2 resultados para Development-oil companies

em DigitalCommons@The Texas Medical Center


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This dissertation study describes the health and HIV related initiatives of multinational oil and gas companies that operate in Nigeria, perceptions of oil and gas company employees, oil and gas company leaders, and key informants from government, public health, community and the Nigerian business coalition on HIV. A mixed method approach was used. Study participants include employees and leaders that worked for multinational oil and gas companies operating in Nigeria and key informants residing in Nigeria. The oil and gas companies that were sampled all had initiatives in place that were consistent with accepted recommended best practices for companies responding to HIV. All of the companies provided comprehensive health and HIV services to employees and dependents; all had HIV initiatives in the community and had formed partnerships with government or NGO/civil societies. Study participants shared the perception that corporate social responsibility was integral to the oil and gas companies conducting business in Nigeria due to the economic gains of the companies from the country/communities and because of the negative impact that oil and gas exploration activities had on communities. Themes identified that played a role in oil and gas companies' response and how decisions were/should be made were: 'business interest', 'social or government influence', 'pressure to respond', and 'community factors'. The study produced information that can be used to inform and guide oil and gas companies' health and HIV initiatives in Nigeria.^

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Estrogens have been implicated in the normal and neoplastic development of the mammary gland. Although estradiol is essential for early mammary differentiation, its role in postnatal ductal morphogenesis is poorly defined. We have found that neonatal estradiol exposure promotes precocious ductal outgrowth and terminal end bud formation in 21 day-old female mice. In contrast to this precocious phenotype, day 21 estradiol-treated epithelium, transplanted into control host fatpads, grows more slowly than control epithelium. Western and immunohistochemical (IHC) analyses indicate that neonatally-estrogenized glands have significantly less total ER than controls at days 7 and 21, and significantly more stromal ER at day 35. Estrogen receptor α (ER) is present in the gland when treatment is initiated at day 1. We propose that the premature activation of ER by neonatal estradiol exposure, during this critical perinatal period, is a key factor in the alteration of mammary growth and ER expression. ^ To address the role of ER function in mammary morphogenesis, we have developed an in vitro system to study the effect of estradiol exposure in vivo. Keratin and ER-positive mammary epithelial cell lines from 7, 21 and 35 day-old oil or estradiol treated mice have been established. Cell lines derived from estradiol-treated mice grow significantly slower than cells from control glands. Although the level of ER expressed by each cell line is correlated to its rate of growth, epithelial growth in vitro is estradiol-independent and antiestrogen-insensitive. Estradiol-induced transcription from an ERE-reporter in transiently-transfected cell lines confirms the functionality of the ER detected by western and IHC. However, there are no differences in estradiol-stimulated transcription between cell lines. ^ In conclusion, neonatal estradiol treatment alters the pattern of ER expression in mammary epithelial and stromal cells in vivo, and the growth of mammary epithelial cells in vivo and in vitro. When grown outside of the estrogenized host, exposed epithelium grows more slowly than the control. Therefore, an extra-epithelial factor is necessary for enhanced epithelial growth. Our model, which couples an in vivo-in vitro approach, can be used in the future to identify factors involved in the period of early mammary outgrowth and carcinogen susceptibility. ^