Association between rectal douching and HIV and other sexually transmitted infections among men who have sex with men: a systematic review and meta-analysis.

BACKGROUND: Men who have sex with men (MSM) are disproportionately affected by HIV and other STIs worldwide. Rectal douching, which is commonly used by MSM in preparation for anal sex, may increase the risk of HIV and other STIs by injuring the rectal mucosa. Results from individual studies reporting associations between rectal douching and HIV and other STIs among MSM are inconsistent. We performed a systematic review and meta-analysis to estimate the association between rectal douching and HIV and other STIs among MSM. METHODS: We searched PubMed, Embase, Scopus and Web of Science for studies published from January 1970 to November 2018. Studies that reported ORs and 95% CIs of associations between rectal douching and infection with HIV/STIs, or reported enough data to calculate these estimates, were included. We assessed risk of bias using the Newcastle-Ottawa Scale. ORs were pooled using a random effects model. RESULTS: Twenty-eight eligible studies were identified in our review, of which 24 (20 398 participants) were included in the meta-analysis. Rectal douching was associated with increased odds of infection with HIV (OR 2.80, 95% CI 2.32 to 3.39), and any STI other than HIV (including hepatitis B virus (HBV), hepatitis C virus (HCV), chlamydia, gonorrhoea, syphilis and human papillomavirus) (OR 2.46, 95% CI 1.95 to 3.11) among MSM. For specific STIs, douching was associated with increased odds of viral hepatitis (HBV, HCV) (OR 3.29, 95% CI 2.79 to 3.87), and chlamydia or gonorrhoea (OR 3.25, 95% CI 2.02 to 5.23). These associations remained significant in studies that adjusted for potential confounders. CONCLUSION: Rectal douching may put MSM at increased risk for infection with HIV and other STIs. Longitudinal studies are needed to clarify this association, and health education materials should inform men of the potential for increased risk of infection with rectal douching.

Engineering nonphosphorylative metabolism to generate lignocellulose-derived products.

Conversion of lignocellulosic biomass into value-added products provides important environmental and economic benefits. Here we report the engineering of an unconventional metabolism for the production of tricarboxylic acid (TCA)-cycle derivatives from D-xylose, L-arabinose and D-galacturonate. We designed a growth-based selection platform to identify several gene clusters functional in Escherichia coli that can perform this nonphosphorylative assimilation of sugars into the TCA cycle in less than six steps. To demonstrate the application of this new metabolic platform, we built artificial biosynthetic pathways to 1,4-butanediol (BDO) with a theoretical molar yield of 100%. By screening and engineering downstream pathway enzymes, 2-ketoacid decarboxylases and alcohol dehydrogenases, we constructed E. coli strains capable of producing BDO from D-xylose, L-arabinose and D-galacturonate. The titers, rates and yields were higher than those previously reported using conventional pathways. This work demonstrates the potential of nonphosphorylative metabolism for biomanufacturing with improved biosynthetic efficiencies.

Effects of selenium form on blood and milk selenium concentrations, milk component and milk fatty acid composition in dairy cows.

BACKGROUND: Human health may be improved if milk with a favorable fatty acid composition and Se concentration is ingested. The present study is to determine how a basal diet supplemented with daily 5 mg Se as Se-enriched yeast (SY) or sodium selenite (SS) affects the fatty acid composition and Se concentration of bovine milk. The effects of Se form on blood Se concentration, erythrocyte glutathione peroxidase 1 (GPx1) activity, serum GPx3 activity and milk yield and component were also studied. RESULTS: Both Se forms, when compared to control group, increased Se concentrations of blood (P < 0.01) and milk (P < 0.01), erythrocyte GPx1 activity (P < 0.05) and milk percentages of polyunsaturated fatty acids (PUFA) (P < 0.05) and cis-9,cis-12 linoleic acid (P < 0.05). Cows supplemented with SY had higher Se levels in blood (P < 0.01) and milk (P < 0.01) and percentage of PUFA in milk (P < 0.05) when compared with those supplemented with SS. Milk yield, milk component and serum GPx3 activity were not significantly affected by Se form. CONCLUSION: Supplementation of diet with SY appears to be of more benefit than SS in producing favorable milk with high PUFA and Se concentrations.

The chemical composition and ultrastructure of uroliths in Boer goats.

The chemical composition and ultrastructure of urinary calculi obtained from male Boer goats were studied using qualitative chemical analysis, scanning electron microscopy, X-ray diffraction, X-ray energy dispersive spectrometry and Fourier transform infra-red spectroscopy. The calculi came from 10 naturally-occurring cases of urolithiasis and from seven cases of urolithiasis experimentally-induced by feeding a cottonseed meal-rice straw diet supplemented with magnesium oxide. The results indicated that the major component of urinary calculi collected from naturally-occurring and experimentally-induced cases of urolithiasis was struvite (magnesium ammonium phosphate). The study also identified previously unreported prismatic crystals in the uroliths of goats, similar to struvite but rich in potassium. The characteristic ultrastructure of struvite uroliths is described along with a brief discussion of their formation.

Study on precipitation of struvite and struvite-K crystal in goats during onset of urolithiasis.

To learn more about the biomineralization process of struvite in ruminants, a seldom noticeable crystal, struvite-K, was investigated in six goats in which urolithiasis was induced by feeding a cottonseed meal and rice straw diet supplemented with MgO. The compositions of crystals and calculi were studied by chemical qualitative analysis and X-ray energy dispersive spectrometry (EDS). The activity product (AP) and relative supersaturation (RSS) of magnesium ammonium phosphate (MAP) and potassium magnesium phosphate (MKP) were calculated to compare the difference of crystals formed in this process. The results showed that calculi consisted of MAP with a little MKP. Crystals in the urine consisted of MAP and MKP before stone formation, but crystals in urine after stone formation mainly consisted of MKP. The AP and RSS of MAP and MKP significantly decreased after stone formation. It was concluded that MAP and MKP may coexist in the crystals of urine before struvite calculi formation but MKP did not precipitate to struvite calculi and was separated out as crystal sedimentation of urine. The changes of crystallization of MAP and MKP contributed partially to the supersaturation status of MAP and MKP during struvite stone formation.