Characterization of cytochrome P450 monooxygenase CYP154H1 from the thermophilic soil bacterium Thermobifida fusca

Cytochrome P450 monooxygenases are valuable biocatalysts due to their ability to hydroxylate unactivated carbon atoms using molecular oxygen. We have cloned the gene for a new cytochrome P450 monooxygenase, named CYP154H1, from the moderately thermophilic soil bacterium Thermobifida fusca. The enzyme was overexpressed in Escherichia coli at up to 14% of total soluble protein and purified to homogeneity in three steps. CYP154H1 activity was reconstituted using putidaredoxin reductase and putidaredoxin from Pseudomonas putida DSM 50198 as surrogate electron transfer partners. In biocatalytic reactions with different aliphatic and aromatic substrates of varying size, the enzyme converted small aromatic and arylaliphatic compounds like ethylbenzene, styrene, and indole. Furthermore, CYP154H1 also accepted different arylaliphatic sulfides as substrates chemoselectively forming the corresponding sulfoxides and sulfones. The enzyme is moderately thermostable with an apparent melting temperature of 67°C and exhibited still 90% of initial activity after incubation at 50°C

Survival among older adults with kidney failure is better in the first three years with chronic dialysis treatment than not

Comparisons of survival between dialysis and nondialysis care for older adults with kidney failure have been limited to those managed by nephrologists, and are vulnerable to lead and immortal time biases. So we compared time to all-cause mortality among older adults with kidney failure treated vs. not treated with chronic dialysis. Our retrospective cohort study used linked administrative and laboratory data to identify adults aged 65 or more years of age in Alberta, Canada, with kidney failure (2002-2012), defined by two or more consecutive outpatient estimated glomerular filtration rates less than 10 mL/min/1.73m2, spanning 90 or more days. We used marginal structural Cox models to assess the association between receipt of dialysis and all-cause mortality by allowing control for both time-varying and baseline confounders. Overall, 838 patients met inclusion criteria (mean age 79.1; 48.6% male; mean estimated glomerular filtration rate 7.8 mL/min/1.73m2). Dialysis treatment (vs. no dialysis) was associated with a significantly lower risk of death for the first three years of follow-up (hazard ratio 0.59 [95% confidence interval 0.46-0.77]), but not thereafter (1.22 [0.69-2.17]). However, dialysis was associated with a significantly higher risk of hospitalization (1.40 [1.16-1.69]). Thus, among older adults with kidney failure, treatment with dialysis was associated with longer survival up to three years after reaching kidney failure, though with a higher risk of hospital admissions. These findings may assist shared decision-making about treatment of kidney failure

Cuticular Ridge Pattern in \u3ci\u3eOstertagia gruehneri\u3c/i\u3e and \u3ci\u3eOstertagia arctica\u3c/i\u3e (Nematoda: Trichostrongyloidea) from Caribou, \u3ci\u3eRangifer tarandus\u3c/i\u3e

Two species of medium stomach worms are common parasites of the caribou, Rangifer tarandus. The two species, Ostertagia gruehneri Skrjabin, 1929, and O. arctica Mitzkewitzsch, 1929, differ so markedly in morphology of the spicules and genital cone that many nematode systematists place them in different genera. Recent studies of similar pairs of species parasitic in other ruminants have provided evidence that such pairs of species may be morphotypes of one species. The two species from caribou are redescribed with emphasis on the pattern of surface cuticular ridges and the structure of the esophagus, characters considered useful for distinguishing species of trichostrongyloid nematodes. Ostertagia gruehneri and O. arctica were found to have identical ridge patterns and esophageal characteristics. Both species had five lateral ridges, a long eosphageal valve, and ducts for the subventral esophageal glands that opened internally posterior to the level of the cervical papillae

Development of {micro}Chemlab{sup TM}/CG for Detection of Biotoxins

The authors have developed a research prototype device for low level detection of SEB, ricin, botulinum toxin and ovalbumin in liquid samples. This hand-held, low power device analyzes samples by capillary zone electrophoresis (CZE) and capillary gel electrophoresis (CGE) in a parallel microchannel format, and provides sensitive detection of fluorescently-tagged analytes using miniature 392 nm diode laser-induced fluorescence. They have successfully demonstrated simultaneous parallel channel separations, fully automated high voltage control of fluidics and automated data analysis with toxin identification and semi-quantitation in the presence of aerosol backgrounds in a stand-alone self-contained unit. Tests of the fully integrated device indicate high sensitivity detection (as low as 5 nM) and cycle times of 5-10 minutes