4% (4.3 to 12.7). We recorded an annual increase of 14% (0% to 29%; p=0.054) in southern Africa and a non-significant increase of 3% (-0.9 to 16; p=0.618) in west and central Africa. There was no change in resistance over time in Latin America, and because of much country-level heterogeneity the meta-regression analysis was not appropriate for Asia. With respect to class of antiretroviral, there were substantial increases in resistance to non-nucleoside reverse transcriptase inhibitors (NNRTI) in east Africa (36% per year [21 to 52]; p<0.0001) and southern Africa (23% per

year [7 to 42]; p=0.0049). No increase was noted for the other drug classes in any region.

Interpretation Our findings suggest a significant increase in prevalence of TNF-alpha inhibitor drug resistance over time since antiretroviral rollout in regions selleck chemical of sub-Saharan Africa; this rise is driven by NNRTI resistance in studies from east and southern Africa. The findings are of concern and draw attention to the need for enhanced surveillance and drug-resistance prevention efforts by national HIV treatment programmes. Nevertheless, estimated levels, although increasing, are not unexpected in view of the large expansion of antiretroviral treatment coverage seen in low-income and middle-income countries-no

changes in antiretroviral treatment guidelines are warranted at the moment.”
“A major challenge associated with recombinant protein production in Escherichia coli is generation of large quantities of soluble, functional protein. Yeast SUMO (small however ubiquitin-related modifier), has been shown to enhance heterologous protein expression

and solubility as fusion tag, however, the effects of human SUMOs on protein expression have not been investigated. Here we describe the use of human SUMO1 and SUMO2 as a useful gene fusion technology.

Human SUMO1 and SUMO2 fusion expression vectors were constructed and tested in His-tag and ubiquitin fusion expression systems. Two difficult-to-express model proteins, matrix metalloprotease-13 (MMP13) and enhanced green fluorescence protein (eGFP) were fused to the C-terminus of the human SUMO1 and SUMO2 expression vectors. These constructs were expressed in E. coil and evaluation of MMP13 and eGFP expression and solubility was conducted. We found that both SUMO1 and SUMO2 had the ability to enhance the solubility of MMP13 and eGFP, with the SUMO2 tag having a more significant effect. Since fusion tags produce varying quantities of soluble proteins, we assessed the effect of SUMO2 coupled with ubiquitin (Ub). SUMO2-ubiquitin and ubiquitin-SUMO2 fusion expression plasmids were constructed with eGFP as a passenger protein. Following expression in E. coil, both plasmids could improve eGFP expression and solubility similar to the SUMO2 fusion and better than the ubiquitin fusion. The sequential order of SUMO2 and ubiquitin had little effect on expression and solubility of eGFP.