Lower Compliance with Cervical Cancer Screening Guidelines Among Vegetarians in North America.

Cervical cancer is preventable and treatable through regular screening and follow-up. However, the utilization of cervical cancer screening may vary widely based on individual lifestyles. The purpose of this study was to examine the differences in the adherence to cervical cancer screening guidelines in various dietary groups. Our study included 21,376 women from the United States and Canada, aged 30-69 from the Adventist Health Study-2, a large population-based prospective cohort study. Modified Poisson regression with robust variance estimation was used to determine the prevalence ratios of cervical cancer screening behavior in participants following five different dietary patterns (non-vegetarians, semi-vegetarians, pesco-vegetarians, lacto-ovo-vegetarians, and vegans). All analyses were adjusted for age, race/ethnicity, marital status, education, personal income, body mass index, smoking, alcohol use, exercise, and family history of all female cancer. Vegetarians, in general, had similar screening prevalence as non-vegetarians. However, vegans were 16% less likely to have had a Pap test compared to non-vegetarians (prevalence ratio (PR) = 0.84, 95% confidence interval 0.81-0.86). Women who were younger, Black, married, more educated, had a family history of all female cancer, had a higher income, and exercise reported higher compliance to a Pap test. It remains to be seen whether vegan women in Adventist Health-2 experience a higher incidence of cervical cancer or are diagnosed at a later stage compared to non-vegetarians.

Cobalt substitution supports an inner-sphere electron transfer mechanism for oxygen reduction in pea seedling amine oxidase.

Copper amine oxidases (CAOs) are a large family of proteins that use molecular oxygen to oxidize amines to aldehydes with the concomitant production of hydrogen peroxide and ammonia. CAOs utilize two cofactors for this reaction: topaquinone (TPQ) and a Cu(II) ion. Two mechanisms for oxygen reduction have been proposed for these enzymes. In one mechanism (involving inner-sphere electron transfer to O(2)), Cu(II) is reduced by TPQ, forming Cu(I), to which O(2) binds, forming a copper-superoxide complex. In an alternative mechanism (involving outer-sphere electron transfer to O(2)), O(2) is directly reduced by TPQ, without reduction of Cu(II). Substitution of Cu(II) with Co(II) has been used to distinguish between the two mechanisms in several CAOs. Because it is unlikely that Co(II) could be reduced to Co(I) in this environment, an inner-sphere mechanism, as described above, is prevented. We adapted metal replacement methods used for other CAOs to the amine oxidase from pea seedlings (PSAO). Cobalt-substituted PSAO (CoPSAO) displayed nominal catalytic activity: k(cat) is 4.7% of the native k(cat), and K(M) (O(2)) for CoPSAO is substantially (22-fold) higher. The greatly reduced turnover number for CoPSAO suggests that PSAO uses the inner-sphere mechanism, as has been predicted from (18)O isotope effect studies (Mukherjee et al. in J Am Chem Soc 130:9459-9473, 2008), and is catalytically compromised when constrained to operate via outer-sphere electron transfer to O(2). This study, together with previous work, provides strong evidence that CAOs use both proposed mechanisms, but each homolog may prefer one mechanism over the other.