Lessons learned from the development of a hidradenitis suppurativa xenograft mouse model.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease originating from the pilosebaceous unit, in which patients develop painful abscesses, sinus tracts, nodules and scarring, typically in intertriginous areas. Major gaps in our understanding of HS exist, and these may be partially due to the lack of an animal model for experimental studies. We developed an HS xenograft mouse model using human HS lesions grafted onto immunocompromised mice. Although the model had its limitations, several informative lessons were learned, which may contribute to future attempts at an HS animal model.

Ritonavir-boosted lopinavir plus nucleoside or nucleotide reverse transcriptase inhibitors versus ritonavir-boosted lopinavir plus raltegravir for treatment of HIV-1 infection in adults with virological failure of a standard first-line ART regimen (SECOND-LINE): a randomised, open-label, non-inferiority study.

BACKGROUND: Uncertainty exists about the best treatment for people with HIV-1 who have virological failure with first-line combination antiretroviral therapy of a non-nucleoside analogue (NNRTI) plus two nucleoside or nucleotide analogue reverse transcriptase inhibitors (NtRTI). We compared a second-line regimen combining two new classes of drug with a WHO-recommended regimen. METHODS: We did this 96-week, phase 3b/4, randomised, open-label non-inferiority trial at 37 sites worldwide. Adults with HIV-1 who had confirmed virological failure (plasma viral load >500 copies per mL) after 24 weeks or more of first-line treatment were randomly assigned (1:1) to receive ritonavir-boosted lopinavir plus two or three NtRTIs (control group) or ritonavir-boosted lopinavir plus raltegravir (raltegravir group). The randomisation sequence was computer generated with block randomisation (block size four). Neither participants nor investigators were masked to allocation. The primary endpoint was the proportion of participants with plasma viral load less than 200 copies per mL at 48 weeks in the modified intention-to-treat population, with a non-inferiority margin of 12%. This study is registered with ClinicalTrials.gov, number NCT00931463. FINDINGS: We enrolled 558 patients, of whom 541 (271 in the control group, 270 in the raltegravir group) were included in the primary analysis. At 48 weeks, 219 (81%) patients in the control group compared with 223 (83%) in the raltegravir group met the primary endpoint (difference 1·8%, 95% CI -4·7 to 8·3), fulfilling the criterion for non-inferiority. 993 adverse events occurred in 271 participants in the control group versus 895 in 270 participants in the raltegravir group, the most common being gastrointestinal. INTERPRETATION: The raltegravir regimen was no less efficacious than the standard of care and was safe and well tolerated. This simple NtRTI-free treatment strategy might extend the successful public health approach to management of HIV by providing simple, easy to administer, effective, safe, and tolerable second-line combination antiretroviral therapy. FUNDING: University of New South Wales, Merck, AbbVie, the Foundation for AIDS Research.

The isolation of large polysomes in high yield from unfractionated tissue homogenates.

It was found that if large quantities of both exogenous RNA and Mg-2+ were present during gentle tissue homogenization, the subsequent addition of deoxycholate to the whole homogenate produced a viscous mass from which polysomes could be isolated in large yields. These polysomes were substantially less degraded than those isolated by previous methods. In the case of rat liver, 15 ribosomes per mRNA was the species present in highest concentration. The parameters of this method were investigated and optimized. About 80 percent of the rRNA in the homogenates was recovered in the polysomes. Omission of deoxycholate permitted the isolation of less-degraded free polysomes as well. In the liver of fed rats these represented one-fourth of the total polysomes, in good agreement with results obtained by an independent approach. Using the method to isolate polysomes from the liver of starving rats, it was found that only about one percent of the large amount of monomers and dimers present resulted from polysome breakdown during isolation. It was further shown that random RNAase hydrolysis of polysomes could not produce the patterns of liver polysomes seen during starvation. Polysomes isolated by this procedure were quite stable in solution and were very active in cell-free protein synthesis. Application of this method without adaptation to eight other tissues also permitted the isolation of large polysomes in high yields.