1,187 research outputs found

    Presynaptic actions of 4-Aminopyridine and γ-aminobutyric acid on rat sympathetic ganglia in vitro

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    Responses to bath-applications of 4-aminopyridine (4-AP) and -aminobutyric acid (GABA) were recorded intracellularly from neurones in the rat isolated superior cervical ganglion. 4-aminopyridine (0.1–1.0 mmol/l) usually induced spontaneous action potentials and excitatory postsynaptic potentials (EPSPs), which were blocked by hexamethonium. Membrane potential was unchanged; spike duration was slightly increased. Vagus nerve B-and C-fibre potentials were prolonged. In 4-AP solution (0.1–0.3 mmol/l), GABA (0.1 mmol/l), 3-aminopropanesulphonic acid or muscimol evoked bursts of spikes and EPSPs in addition to a neuronal depolarization. These bursts, which were not elicited by glycine, glutamate, taurine or (±)-baclofen, were completely antagonised by hexamethonium, tetrodotoxin or bicuculline methochloride. It is concluded that: (a) 4-AP has a potent presynaptic action on sympathetic ganglia; (b) presynaptic actions of GABA can be recorded postsynaptically in the presence of 4-AP; and (c) the presynaptic GABA-receptors revealed in this condition are similar to those on the postsynaptic membrane

    Do red deer stags (Cervus elaphus) use roar fundamental frequency (F0) to assess rivals?

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    It is well established that in humans, male voices are disproportionately lower pitched than female voices, and recent studies suggest that this dimorphism in fundamental frequency (F0) results from both intrasexual (male competition) and intersexual (female mate choice) selection for lower pitched voices in men. However, comparative investigations indicate that sexual dimorphism in F0 is not universal in terrestrial mammals. In the highly polygynous and sexually dimorphic Scottish red deer Cervus elaphus scoticus, more successful males give sexually-selected calls (roars) with higher minimum F0s, suggesting that high, rather than low F0s advertise quality in this subspecies. While playback experiments demonstrated that oestrous females prefer higher pitched roars, the potential role of roar F0 in male competition remains untested. Here we examined the response of rutting red deer stags to playbacks of re-synthesized male roars with different median F0s. Our results show that stags’ responses (latencies and durations of attention, vocal and approach responses) were not affected by the F0 of the roar. This suggests that intrasexual selection is unlikely to strongly influence the evolution of roar F0 in Scottish red deer stags, and illustrates how the F0 of terrestrial mammal vocal sexual signals may be subject to different selection pressures across species. Further investigations on species characterized by different F0 profiles are needed to provide a comparative background for evolutionary interpretations of sex differences in mammalian vocalizations

    Methicillin Resistance Transfer from Staphylocccus epidermidis to Methicillin-Susceptible Staphylococcus aureus in a Patient during Antibiotic Therapy

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    BACKGROUND: The mecA gene, encoding methicillin resistance in staphylococci, is located on a mobile genetic element called Staphylococcal Cassette Chromosome mec (SCCmec). Horizontal, interspecies transfer of this element could be an important factor in the dissemination of methicillin-resistant S. aureus (MRSA). Previously, we reported the isolation of a closely related methicillin-susceptible Staphylococcus aureus (MSSA), MRSA and potential SCCmec donor Staphylococcus epidermidis isolate from the same patient. Based on fingerprint techniques we hypothesized that the S. epidermidis had transferred SCCmec to the MSSA to become MRSA. The aim of this study was to show that these isolates form an isogenic pair and that interspecies horizontal SCCmec transfer occurred. METHODOLOGY/RESULTS: Whole genome sequencing of both isolates was performed and for the MSSA gaps were closed by conventional sequencing. The SCCmec of the S. epidermidis was also sequenced by conventional methods. The results show no difference in nucleotide sequence between the two isolates except for the presence of SCCmec in the MRSA. The SCCmec of the S. epidermidis and the MRSA are identical except for a single nucleotide in the ccrB gene, which results in a valine to alanine substitution. The main difference with the closely related EMRSA-16 is the presence of SaPI2 encoding toxic shock syndrome toxin and exfoliative toxin A in the MSSA-MRSA pair. No transfer of SCCmec from the S. epidermidis to the MSSA could be demonstrated in vitro. CONCLUSION: The MSSA and MRSA form an isogenic pair except for SCCmec. This strongly supports our hypothesis that the MRSA was derived from the MSSA by interspecies horizontal transfer of SCCmec from S. epidermidis O7.1

    Total laparoscopic hysterectomy versus total abdominal hysterectomy with bilateral salpingo-oophorectomy for endometrial carcinoma: a randomised controlled trial with 5-year follow-up

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    This report is on recovery and long-term outcomes in a small-scale randomised controlled trial (RCT) after total laparoscopic hysterectomy versus total abdominal hysterectomy in (potential) endometrial carcinoma patients. An RCT was performed among women with atypical endometrial hyperplasia and endometrial carcinoma scheduled for hysterectomy in a teaching hospital in The Netherlands. Women were randomised to total laparoscopic hysterectomy versus total abdominal hysterectomy both with bilateral salpingo-oophorectomy and were followed until 5 years after the intervention. Patients completed the RAND 36-Item Short Form Health Survey (RAND-36), Quality of Recovery-40 (QoR-40) and Recovery Index-10 (RI-10) until 12 weeks after surgery. Main outcome measure was quality of life and recovery in the first 12 weeks after surgery. A linear mixed model was used for statistical analysis while accounting for baseline values where applicable. Seventeen women were included, of whom 11 allocated to the laparoscopic arm and 6 to the abdominal arm. Laparoscopic hysterectomy performed better on all scales and subscales used in the study. A statistically significant treatment effect, favouring laparoscopic hysterectomy, was found in the total RAND-36 (difference between groups 142 units, 95% confidence interval 46; 236). Clinical follow-up was completed after median 60 months, but this study was too small for conclusions regarding the safety and survival. Laparoscopic hysterectomy results in better postoperative quality of life in the first 12 weeks after surgery when compared with abdominal hysterectomy

    A new frontier for J-band interferometry: Dual-band NIR interferometry with MIRC-X

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    This is the final version. Available from SPIE via the DOI in this recordSPIE Astronomical Telescopes + Instrumentation conference 2020. Online OnlyIn this contribution we report on our work to increase the spectral range of the Michigan Infrared Combiner- eXeter (MIRC-X) instrument at the CHARA array to allow for dual H and J band interferometric observations. We comment on the key science drivers behind this project and the methods of characterisation and correction of instrumental birefringence and dispersion. In addition, we report on the first results from on-sky commissioning in November 2019.Science and Technology Facilities Council (STFC)European Research Council (ERC)NASANational Science Foundation (NSF

    “I would rather be told than not know” - A qualitative study exploring parental views on identifying the future risk of childhood overweight and obesity during infancy

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    BACKGROUND: Risk assessment tools provide an opportunity to prevent childhood overweight and obesity through early identification and intervention to influence infant feeding practices. Engaging parents of infants is paramount for success however; the literature suggests there is uncertainty surrounding the use of such tools with concerns about stigmatisation, labelling and expressions of parental guilt. This study explores parents' views on identifying future risk of childhood overweight and obesity during infancy and communicating risk to parents. METHODS: Semi-structured qualitative interviews were conducted with 23 parents and inductive, interpretive and thematic analysis performed. RESULTS: Three main themes emerged from the data: 1) Identification of infant overweight and obesity risk. Parents were hesitant about health professionals identifying infant overweight as believed they would recognise this for themselves, in addition parents feared judgement from health professionals. Identification of future obesity risk during infancy was viewed positively however the use of a non-judgemental communication style was viewed as imperative. 2) Consequences of infant overweight. Parents expressed immediate anxieties about the impact of excess weight on infant ability to start walking. Parents were aware of the progressive nature of childhood obesity however, did not view overweight as a significant problem until the infant could walk as viewed this as a point when any excess weight would be lost due to increased energy expenditure. 3) Parental attributions of causality, responsibility, and control. Parents articulated a high level of personal responsibility for preventing and controlling overweight during infancy, which translated into self-blame. Parents attributed infant overweight to overfeeding however articulated a reluctance to modify infant feeding practices prior to weaning. CONCLUSION: This is the first study to explore the use of obesity risk tools in clinical practice, the findings suggest that identification, and communication of future overweight and obesity risk is acceptable to parents of infants. Despite this positive response, findings suggest that parents' acceptance to identification of risk and implementation of behaviour change is time specific. The apparent level of parental responsibility, fear of judgement and self-blame also highlights the importance of health professionals approach to personalised risk communication so feelings of self-blame are negated and stigmatisation avoided

    Structural Comparison of Human Mammalian Ste20-Like Kinases

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    BACKGROUND: The serine/threonine mammalian Ste-20 like kinases (MSTs) are key regulators of apoptosis, cellular proliferation as well as polarization. Deregulation of MSTs has been associated with disease progression in prostate and colorectal cancer. The four human MSTs are regulated differently by C-terminal regions flanking the catalytic domains. PRINCIPAL FINDINGS: We have determined the crystal structure of kinase domain of MST4 in complex with an ATP-mimetic inhibitor. This is the first structure of an inactive conformation of a member of the MST kinase family. Comparison with active structures of MST3 and MST1 revealed a dimeric association of MST4 suggesting an activation loop exchanged mechanism of MST4 auto-activation. Together with a homology model of MST2 we provide a comparative analysis of the kinase domains for all four members of the human MST family. SIGNIFICANCE: The comparative analysis identified new structural features in the MST ATP binding pocket and has also defined the mechanism for autophosphorylation. Both structural features may be further explored for inhibitors design. ENHANCED VERSION: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1

    Asteroseismology and Interferometry

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    Asteroseismology provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Recent developments, including the first systematic studies of solar-like pulsators, have boosted the impact of this field of research within Astrophysics and have led to a significant increase in the size of the research community. In the present paper we start by reviewing the basic observational and theoretical properties of classical and solar-like pulsators and present results from some of the most recent and outstanding studies of these stars. We centre our review on those classes of pulsators for which interferometric studies are expected to provide a significant input. We discuss current limitations to asteroseismic studies, including difficulties in mode identification and in the accurate determination of global parameters of pulsating stars, and, after a brief review of those aspects of interferometry that are most relevant in this context, anticipate how interferometric observations may contribute to overcome these limitations. Moreover, we present results of recent pilot studies of pulsating stars involving both asteroseismic and interferometric constraints and look into the future, summarizing ongoing efforts concerning the development of future instruments and satellite missions which are expected to have an impact in this field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume 14, Issue 3-4, pp. 217-36

    Primary care nurses struggle with lifestyle counseling in diabetes care: a qualitative analysis

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    Contains fulltext : 89605.pdf (publisher's version ) (Open Access)BACKGROUND: Patient outcomes are poorly affected by lifestyle advice in general practice. Promoting lifestyle behavior change require that nurses shift from simple advice giving to a more counseling-based approach. The current study examines which barriers nurses encounter in lifestyle counseling to patients with type 2 diabetes. Based on this information we will develop an implementation strategy to improve lifestyle behavior change in general practice. METHOD: In a qualitative semi-structured study, twelve in-depth interviews took place with nurses in Dutch general practices involved in diabetes care. Specific barriers in counseling patients with type 2 diabetes about diet, physical activity, and smoking cessation were addressed. The nurses were invited to reflect on barriers at the patient and practice levels, but mainly on their own roles as counselors. All interviews were audio-recorded and transcribed. The data were analyzed with the aid of a predetermined framework. RESULTS: Nurses felt most barriers on the level of the patient; patients had limited knowledge of a healthy lifestyle and limited insight into their own behavior, and they lacked the motivation to modify their lifestyles or the discipline to maintain an improved lifestyle. Furthermore, nurses reported lack of counseling skills and insufficient time as barriers in effective lifestyle counseling. CONCLUSIONS: The traditional health education approach is still predominant in primary care of patients with type 2 diabetes. An implementation strategy based on motivational interviewing can help to overcome 'jumping ahead of the patient' and promotes skills in lifestyle behavioral change. We will train our nurses in agenda setting to structure the consultation based on prioritizing the behavior change and will help them to develop social maps that contain information on local exercise programs
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