4,134 research outputs found

    The action of mimetic peptides on connexins protects fibroblasts from the negative effects of ischemia reperfusion

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    Connexins have been proposed as a target for therapeutic treatment of a variety of conditions. The main approaches have been by antisense or small peptides specific against connexins. Some of these peptides enhance communication while others interfere with connexin binding partners or bind to the intracellular and extracellular loops of connexins. Here, we explored the mechanism of action of a connexin mimetic peptide by evaluating its effect on gap junction channels, connexin protein levels and hemichannel activity in fibroblast cells under normal conditions and following ischemia reperfusion injury which elevates Cx43 levels, increases hemichannel activity and causes cell death. Our results showed that the effects of the mimetic peptide were concentration-dependent. High concentrations (100-300 μM) significantly reduced Cx43 protein levels and GJIC within 2 h, while these effects did not appear until 6 h when using lower concentrations (10-30 μM). Cell death can be reduced when hemichannel opening and GJIC were minimised

    Role of the mesoamygdaloid dopamine projection in emotional learning

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    Amygdala dopamine is crucially involved in the acquisition of Pavlovian associations, as measured via conditioned approach to the location of the unconditioned stimulus (US). However, learning begins before skeletomotor output, so this study assessed whether amygdala dopamine is also involved in earlier 'emotional' learning. A variant of the conditioned reinforcement (CR) procedure was validated where training was restricted to curtail the development of selective conditioned approach to the US location, and effects of amygdala dopamine manipulations before training or later CR testing assessed. Experiment 1a presented a light paired (CS+ group) or unpaired (CS- group) with a US. There were 1, 2 or 10 sessions, 4 trials per session. Then, the US was removed, and two novel levers presented. One lever (CR+) presented the light, and lever pressing was recorded. Experiment 1b also included a tone stimulus. Experiment 2 applied intra-amygdala R(+) 7-OH-DPAT (10 nmol/1.0 A mu l/side) before two training sessions (Experiment 2a) or a CR session (Experiment 2b). For Experiments 1a and 1b, the CS+ group preferred the CR+ lever across all sessions. Conditioned alcove approach during 1 or 2 training sessions or associated CR tests was low and nonspecific. In Experiment 2a, R(+) 7-OH-DPAT before training greatly diminished lever pressing during a subsequent CR test, preferentially on the CR+ lever. For Experiment 2b, R(+) 7-OH-DPAT infusions before the CR test also reduced lever pressing. Manipulations of amygdala dopamine impact the earliest stage of learning in which emotional reactions may be most prevalent

    Taxonomic distinctness in the diet of two sympatric marine turtle species

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    Marine turtles are considered keystone consumers in tropical coastal ecosystems and their decline through overexploitation has been implicated in the deterioration of reefs and seagrass pastures in the Caribbean. In the present study, we analysed stomach contents of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) harvested in the legal turtle fishery of the Turks and Caicos Islands (Caribbean) during 2008–2010. Small juveniles to adult-sized turtles were sampled. Together with data from habitat surveys, we assessed diet composition and the taxonomic distinctness (and other species diversity measures) in the diets of these sympatric marine turtle species. The diet of green turtles (n = 92) consisted of a total of 47 taxa: including three species of seagrass (present in 99% of individuals), 29 species of algae and eight sponge species. Hawksbill turtles (n = 45) consumed 73 taxa and were largely spongivorous (16 species; sponges present in 100% of individuals) but also foraged on 50 species of algae (present in 73% of individuals) and three species of seagrass. Plastics were found in trace amounts in 4% of green turtle and 9% of hawksbill turtle stomach samples. We expected to find changes in diet that might reflect ontogenetic shifts from small (oceanic-pelagic) turtles to larger (coastal-benthic) turtles. Dietary composition (abundance and biomass), however, did not change significantly with turtle size, although average taxonomic distinctness was lower in larger green turtles. There was little overlap in prey between the two turtle species, suggesting niche separation. Taxonomic distinctness routines indicated that green turtles had the most selective diet, whereas hawksbill turtles were less selective than expected when compared with the relative frequency and biomass of diet items. We discuss these findings in relation to the likely important trophic roles that these sympatric turtle species play in reef and seagrass habitats.This work was funded by Simon & Anne Notley, MCS, and Natural Environment Research Council (CASE PhD studentship to TS with MCS as CASE partners, Ref: NE/F01385X/1)

    Marine turtle harvest in a mixed small-scale fishery: Evidence for revised management measures

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    Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Ocean and Coastal Management. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Ocean and Coastal Management, 2013, Vol. 82, pp. 34 – 42 DOI: http://dx.doi.org/10.1016/j.ocecoaman.2013.05.004Small-scale fisheries (SSF) account for around half of the world's marine and inland fisheries, but their impact on the marine environment is usually under-estimated owing to difficulties in monitoring and regulation. Successful management of mixed SSF requires holistic approaches that sustainably exploit target species, consider non-target species and maintain fisher livelihoods. For two years, we studied the marine turtle fishery in the Turks and Caicos Islands (TCI) in the Wider Caribbean Region, where the main export fisheries are queen conch (Strombus gigas) and the spiny lobster (Panulirus argus); with fin-fish, green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) taken for domestic consumption. We evaluate the turtle harvest in relation to the other fisheries and recommend legislation and management alternatives. We demonstrate the connectivity between multi-species fisheries and artisanal turtle capture: with increasing lobster catch-per-unit-effort (CPUE), hawksbill catch increased whilst green turtle catch decreased. With increasing conch CPUE, hawksbill catch declined and there was no demonstrable effect on green turtle catch. We estimate 176–324 green and 114–277 hawksbill turtles are harvested annually in TCI: the largest documented legal hawksbill fishery in the western Atlantic. Of particular concern is the capture of adult turtles. Current legislation focuses take on larger individuals that are key to population maintenance. Considering these data we recommend the introduction of maximum size limits for both species and a closed season on hawksbill take during the lobster fishing season. Our results highlight the need to manage turtles as part of a broader approach to SSF management

    Keeper-animal interactions: differences between the behaviour of zoo animals affect stockmanship

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    Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowl- edge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n=93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour

    Orlistat after initial dietary/behavioural treatment: changes in body weight and dietary maintenance in subjects with sleep related breathing disorders

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    <p>Abstract</p> <p>Background</p> <p>Sleep related breathing disorders (SRBD) are associated with increased morbidity and mortality and weight loss is recommended to overweight or obese patients with SRBD. However, maintenance of weight loss is difficult to achieve and strategies for weight loss maintenance is needed. Orlistat is a pharmacological agent that reduces the intestinal absorption of fat and may favour long-term weight maintenance.</p> <p>Objective</p> <p>To examine the change in body weight and dietary intake during a 1-year treatment with orlistat after an initial weight loss in obese subjects with SRBD. Furthermore, to explore the dietary determinants of weight maintenance during treatment with orlistat.</p> <p>Methods</p> <p>Men and women with SRBD aged 32-62 years (n = 63) participated in a 3-month dietary intervention to increase intake of vegetables and fruit. After an initial weight loss of 3.4 kg they achieved a mean body mass index of 34.3 ± 4.7 kg/m2. Subsequently they were treated with orlistat for 1 year. During this year, dietary and behavioural interventions to attain weight loss were provided in the course of 14 group sessions. Dietary intake, energy density and food choices were assessed with a food frequency questionnaire before and after orlistat treatment.</p> <p>Results</p> <p>With orlistat, body weight decreased by a mean of 3.5 kg (95% CI 1.5, 5.5). The dietary E% from saturated fat, intake of fatty dairy products and energy density increased after 1 year while intakes of oils, fish and vegetables decreased (all P < 0.05). After multivariate adjustments, weight loss was associated with E% protein (R2<sub>adj </sub>= 0.19 [95% CI 0.10, 0.46]), and inversely associated with E% saturated fat (R2<sub>adj </sub>= 0.20 [95% CI 0.12, 0.47]) and fatty dairy products (R2<sub>adj </sub>= 0.23 [95% CI 0.12, 0.49]).</p> <p>Conclusions</p> <p>Orlistat induced further weight loss, but dietary compliance declined with time. Increasing dietary protein and restricting saturated fat and fatty dairy products may facilitate weight loss with orlistat.</p

    Contribution of anadromous fish to the diet of European catfish in a large river system

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    Many anadromous fish species, when migrating from the sea to spawn in fresh waters, can potentially be a valuable prey for larger predatory fish, thereby efficiently linking these two ecosystems. Here, we assess the contribution of anadromous fish to the diet of European catfish (Silurus glanis) in a large river system (Garonne, southwestern France) using stable isotope analysis and allis shad (Alosa alosa) as an example of anadromous fish. Allis shad caught in the Garonne had a very distinct marine delta(13)C value, over 8 per thousand higher after lipid extraction compared to the mean delta(13)C value of all other potential freshwater prey fish. The delta(13)C values of European catfish varied considerably between these two extremes and some individuals were clearly specializing on freshwater prey, whereas others specialized on anadromous fish. The mean contribution of anadromous fish to the entire European catfish population was estimated to be between 53% and 65%, depending on the fractionation factor used for delta(13)C

    The relationship, structure and profiles of schizophrenia measurements: a post-hoc analysis of the baseline measures from a randomized clinical trial

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    <p>Background</p> <p>To fully assess the various dimensions affected by schizophrenia, clinical trials often include multiple scales measuring various symptom profiles, cognition, quality of life, subjective well-being, and functional impairment. In this exploratory study, we characterized the relationships among six clinical, functional, cognitive, and quality-of-life measures, identifying a parsimonious set of measurements.</p> <p>Methods</p> <p>We used baseline data from a randomized, multicenter study of patients diagnosed with schizophrenia, schizoaffective disorder, or schizophreniform disorder who were experiencing an acute symptom exacerbation (n = 628) to examine the relationship among several outcome measures. These measures included the Positive and Negative Syndrome Scale (PANSS), Montgomery-Asberg Depression Rating Scale (MADRS), Brief Assessment of Cognition in Schizophrenia Symbol Coding Test, Subjective Well-being Under Neuroleptics Scale Short Form (SWN-K), Schizophrenia Objective Functioning Instrument (SOFI), and Quality of Life Scale (QLS). Three analytic approaches were used: 1) path analysis; 2) factor analysis; and 3) categorical latent variable analysis. In the optimal path model, the SWN-K was selected as the final outcome, while the SOFI mediated the effect of the exogenous variables (PANSS, MADRS) on the QLS.</p> <p>Results</p> <p>The overall model explained 47% of variance in QLS and 17% of the variance in SOFI, but only 15% in SWN-K. Factor analysis suggested four factors: "Functioning," "Daily Living," "Depression," and "Psychopathology." A strong positive correlation was observed between the SOFI and QLS (r = 0.669), and both the QLS and SOFI loaded on the "Functioning" factor, suggesting redundancy between these scales. The measurement profiles from the categorical latent variable analysis showed significant variation in functioning and quality of life despite similar levels of psychopathology.</p> <p>Conclusions</p> <p>Researchers should consider collecting PANSS, SOFI, and SWN-K in their trials. This would allow a broad spectrum of assessments that would have the ability to capture a wide range of treatment outcomes and allow for a rich characterization of the subgroups involved. Additional research is needed to identify the critical cognitive measures.</p> <p>Trials registration</p> <p>Clinical trials registration: Predicting Response to Risperidone Treatment Through Identification of Early-onset of Antipsychotic Drug Action in Schizophrenia</p> <p>ClinicalTrials.gov identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00337662">NCT00337662</a>; <url>http://www.clinicaltrials.gov/</url></p

    Attitudes towards chiropractic: an analysis of written comments from a survey of north american orthopaedic surgeons

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    <p>Abstract</p> <p>Background</p> <p>There is increasing interest by chiropractors in North America regarding integration into mainstream healthcare; however, there is limited information about attitudes towards the profession among conventional healthcare providers, including orthopaedic surgeons.</p> <p>Methods</p> <p>We administered a 43-item cross-sectional survey to 1000 Canadian and American orthopaedic surgeons that inquired about demographic variables and their attitudes towards chiropractic. Our survey included an option for respondants to include written comments, and our present analysis is restricted to these comments. Two reviewers, independantly and in duplicate, coded all written comments using thematic analysis.</p> <p>Results</p> <p>487 surgeons completed the survey (response rate 49%), and 174 provided written comments. Our analysis revealed 8 themes and 24 sub-themes represented in surgeons' comments. Reported themes were: variability amongst chiropractors (n = 55); concerns with chiropractic treatment (n = 54); areas where chiropractic is perceived as effective (n = 43); unethical behavior (n = 43); patient interaction (n = 36); the scientific basis of chiropractic (n = 26); personal experiences with chiropractic (n = 21); and chiropractic training (n = 18). Common sub-themes endorsed by surgeon's were diversity within the chiropractic profession as a barrier to increased interprofessional collaboration, endorsement for chiropractic treatment of musculoskeletal complaints, criticism for treatment of non-musculoskeletal complaints, and concern over whether chiropractic care was evidence-based.</p> <p>Conclusions</p> <p>Our analysis identified a number of issues that will have to be considered by the chiropractic profession as part of its efforts to further integrate chiropractic into mainstream healthcare.</p
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