Predictors of erectile dysfunction after transperineal template prostate biopsy.

PURPOSE: To investigate the incidence and possible contributing factors of erectile dysfunction (ED) after transperineal template prostate biopsy (TTPB). MATERIALS AND METHODS: Males undergoing TTPB were prospectively administered a Sexual Health Inventory for Men (SHIM) questionnaire before biopsy and one month after. SHIM questionnaires were repeated at 3- and 9-months for males not receiving interventional treatment. Sexually inactive males were excluded. Interval change in SHIM categories based upon baseline characteristics were evaluated. Multivariable logistic regression models were used to evaluate predictors of change in SHIM score category. RESULTS: A total of 576 males were included in our sample. Of these, 450 (78%) males underwent their first biopsy. A decline in SHIM category within the immediate 4-weeks post-biopsy was reported by 167 males (31% of total eligible sample). Age was the strongest predictor of decline in SHIM category, the predicted probability of a decline in SHIM at age 50 was 10% (95% confidence interval [CI], 1%-19%), 32% at age 60 (95% CI, 25%-40%) and 36% at age 70 (95% CI, 29%-44%). For new onset ED, the predicted probability of ED within 4-weeks post-TTPB were 6.7% at age 50 (95% CI, 0%-15%), 26% at age 60 (95% CI, 17%-34%) and 31% at age 70 (95% CI, 21%-40%). CONCLUSIONS: Older age at biopsy is an independent predictor of immediate ED after TTPB in sexually active males. This association was observed in the subgroup with no pre-existing ED. These findings provide useful information when counselling males undergoing TTPB.

Bacterial SBP56 identified as a Cu-dependent methanethiol oxidase widely distributed in the biosphere.

Oxidation of methanethiol (MT) is a significant step in the sulfur cycle. MT is an intermediate of metabolism of globally significant organosulfur compounds including dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS), which have key roles in marine carbon and sulfur cycling. In aerobic bacteria, MT is degraded by a MT oxidase (MTO). The enzymatic and genetic basis of MT oxidation have remained poorly characterized. Here, we identify for the first time the MTO enzyme and its encoding gene (mtoX) in the DMS-degrading bacterium Hyphomicrobium sp. VS. We show that MTO is a homotetrameric metalloenzyme that requires Cu for enzyme activity. MTO is predicted to be a soluble periplasmic enzyme and a member of a distinct clade of the Selenium-binding protein (SBP56) family for which no function has been reported. Genes orthologous to mtoX exist in many bacteria able to degrade DMS, other one-carbon compounds or DMSP, notably in the marine model organism Ruegeria pomeroyi DSS-3, a member of the Rhodobacteraceae family that is abundant in marine environments. Marker exchange mutagenesis of mtoX disrupted the ability of R. pomeroyi to metabolize MT confirming its function in this DMSP-degrading bacterium. In R. pomeroyi, transcription of mtoX was enhanced by DMSP, methylmercaptopropionate and MT. Rates of MT degradation increased after pre-incubation of the wild-type strain with MT. The detection of mtoX orthologs in diverse bacteria, environmental samples and its abundance in a range of metagenomic data sets point to this enzyme being widely distributed in the environment and having a key role in global sulfur cycling.