Indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes that catalyze the first step in tryptophan catabolism via the kynurenine pathway. TDO is ...widely distributed in both eukaryotes and bacteria. In contrast, IDO has been found only in mammals and yeast. In 2007, a third enzyme, indoleamine 2,3-dioxygenase-2 (IDO2), was discovered. IDO2 is found not only in mammals but also in lower vertebrates. Interestingly, the K(m) value of IDO2 for L-Trp was 500-1000 fold higher than that of IDO1. In this study, we isolated both IDO1 and IDO2 cDNA from a monotreme, the platypus (Ornithorhynchus anatinus), and a marsupial, the gray short-tailed opossum (Monodelphis domestica). We characterized the recombinant proteins and those of other known IDO1/IDO2 in intact cells and a cell-free system. It was found that methylene blue may not be suitable reductant for IDO2, hence resulting in an underestimation of recombinant IDO2 activity. In intact cells, the K(m) value of IDO2 for L-Trp was estimated to be much higher than that of IDO1 and this high K(m) value appears to have been conserved during the evolution of IDO2. The protein encoded by the ancestor gene of IDO1 and IDO2 is likely to have had properties more similar to present day IDO2 than to IDO1.
Aggressive situations occurring within mental health services can harm service users, staff, and the therapeutic environment. There is a consensus that the aggression phenomenon is multidimensional, ...but the picture is still unclear concerning the complex interplay of causal variables and their respective impact. To date, only a small number of empirical studies include users' views of relevant factors. The main objective of this review is to identify and synthesize evidence relating to service users' experiences and views of aggressive situations in mental health settings.
We included qualitative studies of any design reporting on service users' own experiences of conditions contributing to aggressive situations in mental health care and their views on preventative strategies. Eligible articles were identified through an electronic database search (PsycINFO, PubMed, Ovid Nursing Database, Embase, and CINAHL), hand search, and cross-referencing. Extracted data were combined and interpreted using aspects of thematic synthesis.
We reviewed 5,566 records and included 13 studies (ten qualitative and three mixed methods). Service users recognized that both their own mental state and negative aspects of the treatment environment affected the development of aggressive situations. Themes were derived from experiential knowledge and included calls to be involved in questions regarding how to define aggression and relevant triggers, and how to prevent aggressive encounters effectively. The findings suggest that incidents are triggered when users experience staff behavior as custodial rather than caring and when they feel ignored.
The findings highlight the importance of staffs' knowledge and skills in communication for developing relationships based on sensitivity, respect, and collaboration with service users in order to prevent aggressive situations. An important factor is a treatment environment with opportunities for meaningful activities and a preponderance of trained staff who work continuously on the development of conditions and skills for collaborative interaction with users.
Telomeres in human fibroblasts shorten progressively during in vitro culturing and trigger replicative senescence. Furthermore, shortened telomeres can be used as biomarkers of disease. These ...observations have led to the suggestion that telomere dynamics may also be associated with viability and selection for life history variation in non‐human taxa. Model systems to examine this suggestion would particularly benefit from the coexistence of multiple phenotypes within the same species with different life history trade‐offs, since those could be compared in terms of telomere characteristics. This scenario also provokes the classic question of why one morph does not have marginally higher fitness and replaces the others. One explanation is that different morphs have different reproductive tactics with equal relative fitness. In Australian painted dragons (Ctenophorus pictus), males differ in head color, the presence or absence of a gular bib, and reproductive expenditure. Red males out‐compete yellow males in dominance contests, while yellow males copulate quickly and have higher success in sperm competition than red males. Males with bibs better defend partners against rival matings, at the cost of loss of body condition. We show that yellow‐headed and bib‐less males have longer telomeres than red, blue and bibbed males, suggesting that telomere length is positively associated with higher investment into self‐maintenance and less reproductive expenditure.
We have studied a polymorphic lizard with different reproductive tactics and investments and test the hypothesis that morphs differ in telomere dynamics in relation to those morph tactics.
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