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1.  Involvement of a Bacterial Microcompartment in the Metabolism of Fucose and Rhamnose by Clostridium phytofermentans 
PLoS ONE  2013;8(1):e54337.
Clostridium phytofermentans, an anaerobic soil bacterium, can directly convert plant biomass into biofuels. The genome of C. phytofermentans contains three loci with genes encoding shell proteins of bacterial microcompartments (BMC), organelles composed entirely of proteins.
Methodology and Principal Findings
One of the BMC loci has homology to a BMC-encoding locus implicated in the conversion of fucose to propanol and propionate in a human gut commensal, Roseburia inulinivorans. We hypothesized that it had a similar role in C. phytofermentans. When C. phytofermentans was grown on fucose, the major products identified were ethanol, propanol and propionate. Transmission electron microscopy of fucose- and rhamnose-grown cultures revealed polyhedral structures, presumably BMCs. Microarray analysis indicated that during growth on fucose, operons coding for the BMC locus, fucose dissimilatory enzymes, and an ATP-binding cassette transporter became the dominant transcripts. These data are consistent with fucose fermentation producing a 1,2-propanediol intermediate that is further metabolized in the microcompartment encoded in the BMC locus. Growth on another deoxyhexose sugar, rhamnose, resulted in the expression of the same BMC locus and similar fermentation products. However, a different set of dissimilatory enzymes and transport system genes were induced. Quite surprisingly, growth on fucose or rhamnose also led to the expression of a diverse array of complex plant polysaccharide-degrading enzymes.
Based on physiological, genomic, and microarray analyses, we propose a model for the fermentation of fucose and rhamnose in C. phytofermentans that includes enzymes encoded in the same BMC locus. Comparative genomic analysis suggests that this BMC may be present in other clostridial species.
PMCID: PMC3557285  PMID: 23382892
2.  Relationship Between Resting Blood Pressure and Laboratory-Induced Pain Among Healthy Children 
Gender Medicine  2011;8(6):388-398.
Adult studies have demonstrated that increased resting blood pressure (BP) levels correlate with decreased pain sensitivity. However, few studies have examined the relationship between BP and experimental pain sensitivity among children.
This study investigated the association between resting BP levels and experimental pain tolerance, intensity, and unpleasantness in healthy children. We also explored whether these BP–pain relationships were age and gender dependent.
Participants underwent separate 4-trial blocks of cutaneous pressure and thermal pain stimuli, and 1 trial of a cold pain stimulus in counterbalanced order.
A total of 235 healthy children (49.6% female; mean age 12.7 [2.9] years; age range 8–18 years) participated. The study revealed specific gender-based BP–pain relationships. Girls with higher resting systolic BP levels were found to have lower thermal intensity ratings than girls with lower resting systolic BP levels; this relationship was stronger among adolescent girls than among younger girls. Among young girls (8–11 years), those with higher resting diastolic BP (DBP) levels were found to have lower cold intensity and unpleasantness as well as lower thermal intensity ratings than did young girls with lower resting DBP levels; these DBP–pain response relationships were not seen among adolescent girls.
Age, rather than resting BP, was predictive of laboratory pain ratings in boys. The findings suggest that the relationship between BP and experimental pain is age and gender dependent. These aspects of cardiovascular relationships to pain in males and females need further attention to understand their clinical importance.
PMCID: PMC3319441  PMID: 22035675
blood pressure; children; gender differences; laboratory pain

Results 1-2 (2)