Methods for ensuring the highest DNA concentration and yield in future and retrospective trace DNA extracts.

In forensic laboratories, increased extraction efficiency of trace evidence is paramount because analytical success is intrinsically dependent on the quantity of DNA recovered. Moreover, highly concentrated nucleic acids are vital for effective downstream analysis and high quality results. This study investigated the efficiency of extraction with the Qiagen® QIAamp® DNA Investigator kit, and explored improvements to the methodology that would maximise the recovery of low concentration forensic samples. Controlled amounts of starting cellular material were used to mimic trace (or low level) DNA deposits prior to DNA extraction with the Investigator kit. Addition of the provided carrier RNA along with conducting two successive elutions of 50 µL improved the net recovery of DNA to 95%. Concentration with centrifugal filters post-extraction were able to concentrate DNA but a large net loss was observed. For the concentration of historic, retrospectively extracted DNA, centrifugal methods are able to concentrate DNA extracts previously too dilute for analysis. These concentrated volumes, however are small, allowing for minimal downstream analysis attempts before the sample is exhausted.

Implications of adopting new WHO guidelines for antiretroviral therapy initiation in Ethiopia.

OBJECTIVE: To assess the implications of implementing the World Health Organization (WHO) 2010 guidelines for antiretroviral therapy (ART) initiation in adults and adolescents with human immunodeficiency virus (HIV) infection, which recommend initiating ART at a CD4+ T lymphocyte (CD4+) threshold of ≤ 350 cells/mm(3) instead of ≤ 200 cells/mm(3), which was the earlier threshold. METHODS: Between April and May 2010, CD4+ test results were collected for all HIV-infected patients recorded in the pre-ART and ART registers of 19 high-patient-load health centres in Addis Ababa, Ethiopia, and the regions of Amhara, Oromia, SNNPR (Southern Nations, Nationalities and People's Region) and Tigray. At 12 centres patient records were independently reviewed to assess data accuracy. To estimate the total number of patients who would need ART at health centres if Ethiopia adopted the new WHO guidelines, the number of patients needing ART based on current guidelines were added to the number of asymptomatic patients enrolled in pre-ART with a CD4+ count > 200 but ≤ 350 cells/mm(3) FINDINGS: Adoption of the new WHO guidelines would increase the total number of patients on ART in the 19 health centres in Ethiopia by about 30%: from 3583 to 4640. CONCLUSION: The shift in the CD4+ threshold for ART initiation will substantially increase the demand for ART in Ethiopia. Since under the current systems only 60% of Ethiopia's patients in need of ART are receiving the medications, scaling up ART programmes to accommodate the increased demand for drugs will not be possible unless government funding and support increase concurrently.