Community structure and function in a H2-based membrane biofilm reactor capable of bioreduction of selenate and chromate

Two different H₂-based, denitrifying membrane-biofilm reactors (MBfRs) initially reduced Se(VI) or Cr(VI) stably to Se⁰ or Cr(III). When the oxidized contaminants in the influent were switched, each new oxidized contaminant was reduced immediately, and its reduction soon was approximately the same or greater than it had been in its original MBfR. The precipitation of reduced selenium and chromium in the biofilm was verified by scanning electron microscopy and energy dispersive X-ray analysis. These results on selenate and chromate reduction are consistent with the interpretation that the H₂-based biofilm community had a high level of functional diversity. The communities’ structures were assessed by cloning analysis. Dechloromonas spp., a known perchlorate-reducing bacteria, dominated the clones from both reactors during selenate and chromate reductions, which suggests that it may have functional diversity capable of reducing selenate and chromate as secondary and dissimilatory acceptors.     

Genetic Polymorphisms at TIMP3 Are Associated with Survival of Adenocarcinoma of the Gastroesophageal Junction

The poor survival of adenocarcinomas of the gastroesophageal junction (GEJ) makes them clinically important. Discovery of host genetic factors that affect outcome may guide more individualized treatment. This study tests whether constitutional genetic variants in matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) genes are associated with outcome of GEJ adenocarcinoma. Single nucleotide polymorphisms (SNPs) at four TIMP (TIMP1-4) and three MMP genes (MMP2, MMP7 and MMP9) were genotyped in DNA samples from a prospective cohort of patients with primary adenocarcinoma of the GEJ admitted to the British Columbia Cancer Agency. Cox proportional hazards regression, with adjustment for patient, disease and treatment variables, was used to estimate the association of SNPs with survival. Genotypes for 85 samples and 48 SNPs were analyzed. Four SNPs across TIMP3, (rs130274, rs715572, rs1962223 and rs5754312) were associated with survival. Interaction analyses revealed that the survival associations with rs715572 and rs5754312 are specific and significant for 5FU+cisplatin treated patients. Sanger sequencing of the TIMP3 coding and promoter regions revealed an additional SNP, rs9862, also associated with survival. TIMP3 genetic variants are associated with survival and may be potentially useful in optimizing treatment strategies for individual patients.     

Flow Patterns Around the Carapaces of Rigid-bodied, Multi-propulsor Boxfishes (Teleostei: Ostraciidae)

Boxfishes (Teleostei: Ostraciidae) are rigid-body, multi-propulsorswimmers that exhibit unusually small amplitude recoil movementsduring rectilinear locomotion. Mechanisms producing the smoothswimming trajectories of these fishes are unknown, however.Therefore, we have studied the roles the bony carapaces of thesefishes play in generating this dynamic stability. Features ofthe carapaces of four morphologically distinct species of boxfisheswere measured, and anatomically-exact stereolithographic modelsof the boxfishes were constructed. Flow patterns around eachmodel were investigated using three methods: 1) digital particleimage velocimetry (DPIV), 2) pressure distribution measurements,and 3) force balance measurements. Significant differences inboth cross-sectional and longitudinal carapace morphology weredetected among the four species. However, results from the threeinterrelated approaches indicate that flow patterns around thevarious carapaces are remarkably similar. DPIV results revealedthat the keels of all boxfishes generate strong longitudinalvortices that vary in strength and position with angle of attack.In areas where attached, concentrated vorticity was detectedusing DPIV, low pressure also was detected at the carapace surfaceusing pressure sensors. Predictions of the effects of both observedvortical flow patterns and pressure distributions on the carapacewere consistent with actual forces and moments measured usingthe force balance. Most notably, the three complementary experimentalapproaches consistently indicate that the ventral keels of allboxfishes, and in some species the dorsal keels as well, effectivelygenerate self-correcting forces for pitching motions—acharacteristic that is advantageous for the highly variablevelocity fields in which these fishes reside.     

Restraint Stress Potentiated Morphine Sensitization: Involvement of Dopamine Receptors within the Nucleus Accumbens

Sensitization to psychostimulant drugs, as well as morphine, subjected to cross-sensitization with stress. The development of morphine sensitization is associated with enhancements in dopamine overflow in the Nucleus accumbens (NAc). This study aimed to examine the role of accumbal D1/D2-like dopamine receptors in restraint stress (RS) induced sensitization to morphine antinociceptive effects. Adult male Wistar rats weighing 220–250 g underwent stereotaxic surgery. Two stainless steel guide cannulae were bilaterally implanted, 1 mm above the NAc injection site. Different solutions of SCH-23390, as a D1-like receptor antagonist or sulpiride, as a D2-like receptor antagonist, were microinjected into the NAc five min before exposure to RS. Restraint stress lasted for 3 h, 10 min after RS termination; animals received a subcutaneous injection of morphine (1 mg/kg) for 3 consecutive days. The procedure was followed by a 5-day drug and/or stress-free period. After that, on the 9th day, the nociceptive response was evaluated by the tail-flick test. The results revealed that intra-NAc administration of D1/D2-like dopamine receptor antagonists, SCH-23390 or sulpiride, respectively, blocked morphine sensitization-induced by RS and morphine co-administration in rats for three consecutive days. This work provides new insight into the determinant role of accumbal dopamine receptors in morphine sensitization produced by RS-morphine co-administration.