A membrane bioreactor for biotransformations of hydrophobic molecules using organic solvent nanofiltration (OSN) membranes

Thiswork reports the application of organic solvent nanofiltration (OSN) membranes to a membrane bioreactor for biotransformations (MBB). An organic solvent phasewas employed, allowing high substrate loadings and efficient product removal. The aqueous and organic phases were separated by an OSN membrane. The biotransformation of geraniol to R-citronellol by baker’s yeast was used as the model reaction, and n-hexadecane and toluene as the organic solvents. The performance of the MBB was compared to that of a direct contact biphasic (DCB) bioreactor. The MBB system resulted in lower productivities than the DCB system due to mass transfer limitations. For the n-hexadecane system, the membrane was the main mass transfer resistance, whereas for the toluene system the contribution of the aqueous liquid film mass transfer resistance became predominant. Further investigations are needed to improve the substrate transfer rates. Despite this, the MBB system prevented aqueous breakthrough, and thus the formation of two-phase emulsions. Toluene toxicity to the biocatalyst was also minimized, although it caused a reduction in the reaction enantiospecificity. This work showed that OSN-MBB systems avoid the formation of emulsions, thus reducing downstream separation and allowing increased substrate loadings

The absolute configuration of (+)-(E)-4-phenylbut-3-ene-2-ol

A derivative of (+)-( E)-4-phenylbut-3-ene-2-ol is shown by Xray crystallography to be of ( R) configuration, confirming the assumption in the literature that the absolute configuration of (+)-( E)- 4-phenylbut-3-ene-2-ol is (R)

cGAS-mediated induction of type I interferon due to inborn errors of histone pre-mRNA processing

International audienceInappropriate stimulation or defective negative regulation of the type I interferon response can lead to autoinflammation. In genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, we identified biallelic mutations in LSM11 and RNU7-1, which encode components of the replication-dependent histone pre-mRNA-processing complex. Mutations were associated with the misprocessing of canonical histone transcripts and a disturbance of linker histone stoichiometry. Additionally, we observed an altered distribution of nuclear cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) and enhanced interferon signaling mediated by the cGAS-stimulator of interferon genes (STING) pathway in patient-derived fibroblasts. Finally, we established that chromatin without linker histone stimulates cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) production in vitro more efficiently. We conclude that nuclear histones, as key constituents of chromatin, are essential in suppressing the immunogenicity of self-DNA

Enhanced infection prophylaxis reduces mortality in severely immunosuppressed HIV-infected adults and older children initiating antiretroviral therapy in Kenya, Malawi, Uganda and Zimbabwe: the REALITY trial

Meeting abstract FRAB0101LB from 21st International AIDS Conference 18–22 July 2016, Durban, South Africa. Introduction: Mortality from infections is high in the first 6 months of antiretroviral therapy (ART) among HIV‐infected adults and children with advanced disease in sub‐Saharan Africa. Whether an enhanced package of infection prophylaxis at ART initiation would reduce mortality is unknown. Methods: The REALITY 2×2×2 factorial open‐label trial (ISRCTN43622374) randomized ART‐naïve HIV‐infected adults and children >5 years with CD4 <100 cells/mm3. This randomization compared initiating ART with enhanced prophylaxis (continuous cotrimoxazole plus 12 weeks isoniazid/pyridoxine (anti‐tuberculosis) and fluconazole (anti‐cryptococcal/candida), 5 days azithromycin (anti‐bacterial/protozoal) and single‐dose albendazole (anti‐helminth)), versus standard‐of‐care cotrimoxazole. Isoniazid/pyridoxine/cotrimoxazole was formulated as a scored fixed‐dose combination. Two other randomizations investigated 12‐week adjunctive raltegravir or supplementary food. The primary endpoint was 24‐week mortality. Results: 1805 eligible adults (n = 1733; 96.0%) and children/adolescents (n = 72; 4.0%) (median 36 years; 53.2% male) were randomized to enhanced (n = 906) or standard prophylaxis (n = 899) and followed for 48 weeks (3.8% loss‐to‐follow‐up). Median baseline CD4 was 36 cells/mm3 (IQR: 16–62) but 47.3% were WHO Stage 1/2. 80 (8.9%) enhanced versus 108(12.2%) standard prophylaxis died before 24 weeks (adjusted hazard ratio (aHR) = 0.73 (95% CI: 0.54–0.97) p = 0.03; Figure 1) and 98(11.0%) versus 127(14.4%) respectively died before 48 weeks (aHR = 0.75 (0.58–0.98) p = 0.04), with no evidence of interaction with the two other randomizations (p > 0.8). Enhanced prophylaxis significantly reduced incidence of tuberculosis (p = 0.02), cryptococcal disease (p = 0.01), oral/oesophageal candidiasis (p = 0.02), deaths of unknown cause (p = 0.02) and (marginally) hospitalisations (p = 0.06) but not presumed severe bacterial infections (p = 0.38). Serious and grade 4 adverse events were marginally less common with enhanced prophylaxis (p = 0.06). CD4 increases and VL suppression were similar between groups (p > 0.2). Conclusions: Enhanced infection prophylaxis at ART initiation reduces early mortality by 25% among HIV‐infected adults and children with advanced disease. The pill burden did not adversely affect VL suppression. Policy makers should consider adopting and implementing this low‐cost broad infection prevention package which could save 3.3 lives for every 100 individuals treated

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field