Purification of hydroxylamine oxidase from Thiosphaera pantotropha Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification

AbstractThiosphaera pantotropha, a Gram-negative heterotrophic nitrifying bacterium, expresses a soluble 20 kDa monomeric periplasmic hydroxylamine oxidase that differs markedly from the hydroxylamine oxidase found in autotrophic bacteria. This enzyme can use the periplasmic redox proteins, cytochrome C551 and pseudoazurin as electron acceptors, both of which can also donate electrons to denitrification enzymes. A model of electron transfer is proposed, that suggests a coupling of nitrification to denitrification and provides a mechanism by which nitrification can play a role in dissipating reductant

Lifestyle behaviors, obesity, and perceived health among men with and without a diagnosis of prostate cancer: A population-based, cross-sectional study

<p>Abstract</p> <p>Background</p> <p>A better understanding of how prostate cancer survivors differ from men without prostate cancer and whether these potential differences vary across demographic subgroups will help to focus and prioritize future public health interventions for improving the health and well-being of prostate cancer survivors. Therefore, our study aims were to compare lifestyle behaviors, body mass index (BMI), and perceived health in men with and without a diagnosis of prostate cancer in a national, population-based sample and to explore whether these comparisons differ for demographic subgroups.</p> <p>Methods</p> <p>In a cross-sectional study, men aged ≥ 40 were identified from the Behavioral Risk Factor Surveillance System (BRFSS) 2002 data (n = 63,662). Respondents reporting history of prostate cancer (n = 2,524) were compared with non prostate cancer controls (n = 61,138) with regard to daily fruit and vegetable servings (FVPD), smoking, alcohol, sedentary behavior, BMI, and perceived health. Multivariable logistic regression calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) for the entire sample and for age, race, education, and urbanicity subgroups.</p> <p>Results</p> <p>Men with prostate cancer did not differ from men without prostate cancer with regard to smoking, alcohol, sedentary behavior, and obesity but were more likely to consume ≥ 5 FVPD (OR, 95% CI: 1.30, 1.09–1.56) and report poor or fair health (OR, 95% CI: 1.62, 1.33–1.97). Subgroup analyses demonstrated attenuation of the higher likelihood of ≥ 5 FVPD among prostate cancer survivors in rural respondents (OR, 95% CI: 0.98, 0.72–1.33). Poorer perceived health was greatest if ≤ 65 years of age (OR, 95% CI: 2.54, 1.79–3.60) and nonsignificant if black (OR, 95% CI: 1.41, 0.70–2.82). Smoking and alcohol which were not significant for the sample as a whole, demonstrated significant associations in certain subgroups.</p> <p>Conclusion</p> <p>Although efforts to enhance perceived health and healthy lifestyle behaviors among prostate cancer survivors are warranted, demographic subgroups such as prostate cancer survivors ≤ 65 and rural populations may require more aggressive interventions.</p

A Temperature-Sensitive Chlorophyll b-Deficient Mutant of Sweetclover (\u3ci\u3eMelilotus alba\u3c/i\u3e)

The ch4 mutant of sweetclover (Melilotus alba) has previously been demonstrated to be partially deficient in chlorophyll and to have a higher ratio of chlorophyll a to b than normal plants. We were able to substantiate these findings when plants were grown at 23°C and lower (permissive temperatures). However, when grown at 26°C (nonpermissive temperature) the plants produced small yellow leaves which exhibited one-twentieth the chlorophyll content of normal plants. Affected leaves did not increase their chlorophyll content when plants were incubated at permissive temperatures, but leaves which developed at the lower temperature contained increased amounts of chlorophyll. Similarly, only new leaves, not previously grown leaves, exhibited the yellow phenotype when the mutant plant was shifted from the permissive temperature to the nonpermissive temperature. Ribulose 1,5-bisphosphate carboxylase activity was decreased by half, relative to normal plants, in the mutant plants grown at the nonpermissive temperature, indicating that general protein synthesis was not greatly impaired and that the effect of the mutation was perhaps specific for chlorophyll content. HPLC analysis indicated that carotenoid content was not diminished to the same extent as chlorophyll and we have determined that the thylakoid protein kinase is not altered, as is the case for other chlorophyll b-deficient mutants. Experiments suggest that changes in photoperiod may be able to modulate the effect of temperature