Abstract(1) The role of the ubiquinone pool in the reactions of the cyclic electron-transfer chain has been investigated by observing the effects of reduction of the ubiquinone pool on the kinetics and extent of the cytochrome and electrochromic carotenoid absorbance changes following flash illumination. (2) In the presence of antimycin, flash-induced reduction of cytochrome b-561 is dependent on a coupled oxidation of ubiquinol. The ubiquinol oxidase site of the ubiquinol:cytochrome c 2 oxidoreductase catalyses a concerted reaction in which one electron is transferred to a high-potential chain containing cytochromes c 1 and c 2 , the Rieske-type iron-sulfur center, and the reaction center primary donor, and a second electron is transferred to a lowpotential chain containing cytochromes b-566 and b-561. (3) The rate of reduction of cytochrome b-561 in the presence of antimycin has been shown to reflect the rate of turnover of the ubiquinol oxidase site. This diagnostic feature has been used to measure the dependence of the kinetics of the site on the ubiquinol concentration. Over a limited range of concentration (0-3 mol ubiquinol/ mol cytochrome b-561), the kinetics showed a second-order process, first order with respect to ubiquinol from the pool. At higher ubiquinol concentrations, other processes became rate determining, so that above approx. 25 mol ubiquinol/mol cytochrome b-561, no further increase in rate was seen. (4) The kinetics and extents of cytochrome b-561 reduction following a flash in the presence of antimycin, and of the antimycin-sensitive reduction of cytochrome c 1 and c 2 , and the slow phase of the carotenoid change, have been measured as a function of redox potential over a wide range. The initial rate for all these processes increased on reduction of the suspension over the range between 180 and 100 mV (pH 7). The increase in rate occurred as the concentration of ubiquinol in the pool increased on reduction, and could be accounted for in terms of the increased rate of ubiquinol oxidation. It is not necessary to postulate the presence of a tightly bound quinone at this site with altered redox properties, as has been previously assumed. (5) The antimycinsensitive reactions reflect the turnover of a second catalytic site of the complex, at which cytochrome b-561 is oxidized in an electrogenic reaction. We propose that ubiquinone is reduced at this site with a mechanism similar to that of the two-electron gate of the reaction center. We suggest that antimycin binds at this site, and displaces the quinone species so that all reactions at the site are inhibited. (6) In coupled chromatophores, the turnover of the ubiquinone reductase site can be measured by the antimycin-sensitive slow phase of the electrochromic carotenoid change. At redox potentials higher than 180 mV, where the pool is completely oxidized, the maximal extent of the slow phase is half that at 140 mV, where the pool contains approx. 1 mol ubiquinone/ mol cytochrome b-561 before the flash. At both potentials, cytochrome b-561 be...

Abstract-Older adults in nursing homes experience pain that is often underassessed and undertreated. Visual analog painintensity scales, recommended for widespread use in adults, do not work well in the older adult population. A variety of other tools are in use, including the Verbal Descriptor Scale, the Faces Pain Scale (FPS), and the Numeric Rating Scale. These tools are more acceptable to older adults, but no agreement exists about how to compare the resulting pain-intensity scores across residents. This study examined the equivalency of painintensity scores for 135 nursing home residents who reported their pain on the three different instruments. The results were validated with a second sample of 135 nursing home residents. The pain levels across the three tools were highly correlated, but residents were found to underrate higher pain intensity on the FPS. A modification of scoring for the FPS led to greater agreement across the three tools. The findings have implications for use of these tools for quality improvement and public reporting of pain.

BackgroundShared medical appointments (SMAs) are doctor-patient visits in which groups of patients are seen by one or more health care providers in a concurrent session. There is a growing interest in understanding the potential benefits of SMAs in various contexts to improve clinical outcomes and reduce healthcare costs. This study builds upon the existing evidence base that suggests SMAs are indeed effective. In this study, we explored how they are effective in terms of the underlying mechanisms of action and under what circumstances.MethodsRealist review methodology was used to synthesize the literature on SMAs, which included a broad search of 800+ published articles. 71 high quality primary research articles were retained to build a conceptual model of SMAs and 20 of those were selected for an in depth analysis using realist methodology (i.e.,middle-range theories and and context-mechanism-outcome configurations).ResultsNine main mechanisms that serve to explain how SMAs work were theorized from the data immersion process and configured in a series of context-mechanism-outcome configurations (CMOs). These are: (1) Group exposure in SMAs combats isolation, which in turn helps to remove doubts about one’s ability to manage illness; (2) Patients learn about disease self-management vicariously by witnessing others’ illness experiences; (3) Patients feel inspired by seeing others who are coping well; (4) Group dynamics lead patients and providers to developing more equitable relationships; (5) Providers feel increased appreciation and rapport toward colleagues leading to increased efficiency; (6) Providers learn from the patients how better to meet their patients’ needs; (7) Adequate time allotment of the SMA leads patients to feel supported; (8) Patients receive professional expertise from the provider in combination with first-hand information from peers, resulting in more robust health knowledge; and (9) Patients have the opportunity to see how the physicians interact with fellow patients, which allows them to get to know the physician and better determine their level of trust.ConclusionsNine overarching mechanisms were configured in CMO configurations and discussed as a set of complementary middle-range programme theories to explain how SMAs work. It is anticipated that this innovative work in theorizing SMAs using realist review methodology will provide policy makers and SMA program planners adequate conceptual grounding to design contextually sensitive SMA programs in a wide variety of settings and advance an SMA research agenda for varied contexts.

The effect of a proton pump inhibitor on gastrointestinal (GI) microbiota was evaluated. Eight healthy 9-month-old dogs (four males and four females) received omeprazole (1.1 mg kg(-1) ) orally twice a day for 15 days. Fecal samples and endoscopic biopsies from the stomach and duodenum were obtained on days 30 and 15 before omeprazole administration, on day 15 (last day of administration), and 15 days after administration. The microbiota was evaluated using 16S rRNA gene 454-pyrosequencing, fluorescence in situ hybridization, and qPCR. In the stomach, pyrosequencing revealed a decrease in Helicobacter spp. during omeprazole (median 92% of sequences during administration compared to > 98% before and after administration; P = 0.0336), which was accompanied by higher proportions of Firmicutes and Fusobacteria. FISH confirmed this decrease in gastric Helicobacter (P < 0.0001) and showed an increase in total bacteria in the duodenum (P = 0.0033) during omeprazole. However, Unifrac analysis showed that omeprazole administration did not significantly alter the overall phylogenetic composition of the gastric and duodenal microbiota. In feces, qPCR showed an increase in Lactobacillus spp. during omeprazole (P < 0.0001), which was accompanied by a lower abundance of Faecalibacterium spp. and Bacteroides-Prevotella-Porphyromonas in the male dogs. This study suggests that omeprazole administration leads to quantitative changes in GI microbiota of healthy dogs.

Mobile phones and SMS show promise as a technology to deliver self-management interventions to improve outcomes of chronic care management. However, the quality of future studies and systematic reviews needs to be improved. There also are unresolved issues about the technology itself.