Chimpanzee APOBEC3 proteins deter SIVs from any monkey business

Cross-species transmissions of viruses from animals to humans are at the origin of major human pathogenic viruses. While the role of ecological and epidemiological factors in the emergence of new pathogens is well documented, the importance of host factors is often unknown. Chimpanzees are the closest relatives of humans and the animal reservoir at the origin of the human AIDS pandemic. However, despite being regularly exposed to monkey lentiviruses through hunting, chimpanzees are naturally infected by only a single simian immunodeficiency virus, SIVcpz. Here, we asked why chimpanzees appear to be protected against the successful emergence of other SIVs. In particular, we investigated the role of the chimpanzee APOBEC3 genes in providing a barrier to infection by most monkey lentiviruses. We found that most SIV Vifs, including Vif from SIVwrc infecting western-red colobus, the chimpanzee's main monkey prey in West Africa, could not antagonize chimpanzee APOBEC3G. Moreover, chimpanzee APOBEC3D, as well as APOBEC3F and APOBEC3H, provided additional protection against SIV Vif antagonism. Consequently, lentiviral replication in primary chimpanzee CD4(+) T cells was dependent on the presence of a lentiviral vif gene that could antagonize chimpanzee APOBEC3s. Finally, by identifying and functionally characterizing several APOBEC3 gene polymorphisms in both common chimpanzees and bonobos, we found that these ape populations encode APOBEC3 proteins that are uniformly resistant to antagonism by monkey lentiviruses

Provision of prosthetic and orthotic services in low-income countries : a review of the literature

Disability is inextricably linked to poverty. A total of 80% of the disabled population lives in low-income countries. The demand for prosthetic and orthotic services in these countries is increasing, and a variety of methods to provide services are currently used. To assess current models of provision to facilitate sustainable, evidence-based prosthetic and orthotic services. A literature search was performed through Medline (Ovid), PubMed, ISI Web of Knowledge, EMBASE and RECAL Legacy using combinations of subject heading and text word searching strategies. Full-text publications were critically appraised and ranked according to the Scottish Intercollegiate Guidelines Network guidelines. Three areas were deemed pertinent to the research question. Studies were grouped into one or more of these categories based on the issues addressed: instigators, types of service provision, demographics and region-specific issues. It was found that many complex factors influence prosthetic and orthotic services in low-income countries. Demographic and regional idiosyncrasies require prosthetic and orthotic services to be tailored to address the specific needs of individual countries. The lack of and quality of available research made efficacy of methods used to provide services in low-income countries difficult to determine. This review aims to highlight areas of best practice in prosthetic and orthotic services in low-income countries and to show where further research is required in order to develop evidence-based prosthetic and orthotic services