Exploratory study examining barriers to participation in colorectal cancer screening.

OBJECTIVE: To examine the Stage of Change distribution for bowel cancer screening in a regional Australian community and the factors associated with varying positions on the continuum of change. DESIGN: Survey of a convenience sample. SETTING: Community sample. PARTICIPANTS: A total of 59 (31 male, mean age = 59) service club members from a South Australian regional community. MAIN OUTCOME MEASURE: Self-reported Stage of Change for bowel cancer screening behaviour. RESULTS: Attributing greater embarrassment and discomfort to bowel cancer screening was associated with earlier positions on the Stages of Change. Perceiving that bowel cancer screening might have positive value for personal health was associated with more advanced positions on the continuum of change. Those who perceived breast and prostate screening procedures to be embarrassing or to cause discomfort were significantly less likely to be participating in bowel cancer screening. No significant relationships were found between bowel cancer screening Stage of Change and worry about vulnerability; personal, family or wider social network case reports of bowel cancer; and the population-level value attributed to the cancer screening procedures. CONCLUSION: Bowel cancer screening participation rates are currently lower than those associated with breast and prostate screening. Reducing perceptions of embarrassment and discomfort, increasing awareness of potential health benefits and maximising participation in other screening procedures might increase participation in bowel cancer screening.

Deciphering the genetic basis for polyketide variation among mycobacteria producing mycolactones.

BACKGROUND: Mycolactones are immunosuppressive and cytotoxic polyketides, comprising five naturally occurring structural variants (named A/B, C, D, E and F), produced by different species of very closely related mycobacteria including the human pathogen, Mycobacterium ulcerans. In M. ulcerans strain Agy99, mycolactone A/B is produced by three highly homologous type I polyketide megasynthases (PKS), whose genes (mlsA1: 51 kb, mlsA2: 7.2 kb and mlsB: 42 kb) are found on a 174 kb plasmid, known as pMUM001. RESULTS: We report here comparative genomic analysis of pMUM001, the complete DNA sequence of a 190 kb megaplasmid (pMUM002) from Mycobacterium liflandii 128FXT and partial sequence of two additional pMUM replicons, combined with liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis. These data reveal how PKS module and domain differences affecting MlsB correlate with the production of mycolactones E and F. For mycolactone E these differences from MlsB in M. ulcerans Agy99 include replacement of the AT domain of the loading module (acetate to propionate) and the absence of an entire extension module. For mycolactone F there is also a reduction of one extension module but also a swap of ketoreductase domains that explains the characteristic stereochemistry of the two terminal side-chain hydroxyls, an arrangement unique to mycolactone F CONCLUSION: The mycolactone PKS locus on pMUM002 revealed the same large, three-gene structure and extraordinary pattern of near-identical PKS domain sequence repetition as observed in pMUM001 with greater than 98.5% nucleotide identity among domains of the same function. Intra- and inter-strain comparisons suggest that the extreme sequence homogeneity seen among the mls PKS genes is caused by frequent recombination-mediated domain replacement. This work has shed light on the evolution of mycolactone biosynthesis among an unusual group of mycobacteria and highlights the potential of the mls locus to become a toolbox for combinatorial PKS biochemistry.

Shedding of Hepatitis C Virus in Semen of Human Immunodeficiency Virus-Infected Men.

Background. The epidemic of sexually transmitted hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) has been documented for over a decade. Despite this, there is no consensus as to the risk factors for sexual acquisition of HCV in these men. Methods. We obtained paired semen and blood samples at 2-week intervals from HIV-infected MSM with recent and chronic HCV infection and quantified HCV in semen. Results. Hepatitis C virus was quantified in 59 semen specimens from 33 men. Hepatitis C virus was shed in 16 (27%) of semen specimens from 11 (33%) of the men. Median HCV viral load (VL) in semen was 1.49 log10 IU/mL. Hepatitis C virus VL in blood was significantly higher at the time of HCV shedding in semen than when HCV shedding in semen was not detected (P = .002). Furthermore, there was a significant correlation between the HCV VL in blood and semen overall (rs = 0.41; P = .001), and in the subgroup with recent HCV infection (rs = 0.37; P = .02), but not in the subgroup with chronic HCV infection (rs = 0.34; P = .1). Conclusions. One third of HIV-infected MSM coinfected with HCV shed HCV into their semen. Based on the HCV VL in semen in this study, an average ejaculate would deliver up to 6630 IU of virus into the rectum of the receptive partner. Therefore, our data strongly support that condoms should be used during anal intercourse among MSM to prevent transmission of HCV.

Case report of deep vein thrombosis caused by artificial urinary sphincter reservoir compressing right external iliac vein.

Artificial urinary sphincters (AUSs) are commonly used after radical prostatectomy for those who are incontinent of urine. However, they are associated with complications, the most common being reservoir uprising or migration. We present a unique case of occlusive external iliac and femoral vein obstruction by the AUS reservoir causing thrombosis. Deflation of the reservoir and anticoagulation has, thus far, not been successful at decreasing thrombus burden. We present this case as a rare, but significant surgical complication; explore the risk factors that may have contributed, and other potential endovascular therapies to address this previously unreported AUS complication.

Evolution of Mycobacterium ulcerans and other mycolactone-producing mycobacteria from a common Mycobacterium marinum progenitor.

It had been assumed that production of the cytotoxic polyketide mycolactone was strictly associated with Mycobacterium ulcerans, the causative agent of Buruli ulcer. However, a recent study has uncovered a broader distribution of mycolactone-producing mycobacteria (MPM) that includes mycobacteria cultured from diseased fish and frogs in the United States and from diseased fish in the Red and Mediterranean Seas. All of these mycobacteria contain versions of the M. ulcerans pMUM plasmid, produce mycolactones, and show a high degree of genetic relatedness to both M. ulcerans and Mycobacterium marinum. Here, we show by multiple genetic methods, including multilocus sequence analysis and DNA-DNA hybridization, that all MPM have evolved from a common M. marinum progenitor to form a genetically cohesive group among a more diverse assemblage of M. marinum strains. Like M. ulcerans, the fish and frog MPM show multiple copies of the insertion sequence IS2404. Comparisons of pMUM and chromosomal gene sequences demonstrate that plasmid acquisition and the subsequent ability to produce mycolactone were probably the key drivers of speciation. Ongoing evolution among MPM has since produced at least two genetically distinct ecotypes that can be broadly divided into those typically causing disease in ectotherms (but also having a high zoonotic potential) and those causing disease in endotherms, such as humans.