Identifying Ligand Binding Conformations of the β2-Adrenergic Receptor by Using Its Agonists as Computational Probes

Recently available G-protein coupled receptor (GPCR) structures and biophysical studies suggest that the difference between the effects of various agonists and antagonists cannot be explained by single structures alone, but rather that the conformational ensembles of the proteins need to be considered. Here we use an elastic network model-guided molecular dynamics simulation protocol to generate an ensemble of conformers of a prototypical GPCR, β2-adrenergic receptor (β2AR). The resulting conformers are clustered into groups based on the conformations of the ligand binding site, and distinct conformers from each group are assessed for their binding to known agonists of β2AR. We show that the select ligands bind preferentially to different predicted conformers of β2AR, and identify a role of β2AR extracellular region as an allosteric binding site for larger drugs such as salmeterol. Thus, drugs and ligands can be used as "computational probes" to systematically identify protein conformers with likely biological significance. © 2012 Isin et al

Metabolic and Behavioral Compensations in Response to Caloric Restriction: Implications for the Maintenance of Weight Loss

BackgroundMetabolic and behavioral adaptations to caloric restriction (CR) in free-living conditions have not yet been objectively measured.Methodology and principal findingsForty-eight (36.8+/-1.0 y), overweight (BMI 27.8+/-0.7 kg/m(2)) participants were randomized to four groups for 6-months;Controlenergy intake at 100% of energy requirements; CR: 25% calorie restriction; CR+EX: 12.5% CR plus 12.5% increase in energy expenditure by structured exercise; LCD: low calorie diet (890 kcal/d) until 15% weight reduction followed by weight maintenance. Body composition (DXA) and total daily energy expenditure (TDEE) over 14-days by doubly labeled water (DLW) and activity related energy activity (AREE) were measured after 3 (M3) and 6 (M6) months of intervention. Weight changes at M6 were -1.0+/-1.1% (CONTROL), -10.4+/-0.9% (CR), -10.0+/-0.8% (CR+EX) and -13.9+/-0.8% (LCD). At M3, absolute TDEE was significantly reduced in CR (-454+/-76 kcal/d) and LCD (-633+/-66 kcal/d) but not in CR+EX or controls. At M6 the reduction in TDEE remained lower than baseline in CR (-316+/-118 kcal/d) and LCD (-389+/-124 kcal/d) but reached significance only when CR and LCD were combined (-351+/-83 kcal/d). In response to caloric restriction (CR/LCD combined), TDEE adjusted for body composition, was significantly lower by -431+/-51 and -240+/-83 kcal/d at M3 and M6, respectively, indicating a metabolic adaptation. Likewise, physical activity (TDEE adjusted for sleeping metabolic rate) was significantly reduced from baseline at both time points. For control and CR+EX, adjusted TDEE (body composition or sleeping metabolic rate) was not changed at either M3 or M6.ConclusionsFor the first time we show that in free-living conditions, CR results in a metabolic adaptation and a behavioral adaptation with decreased physical activity levels. These data also suggest potential mechanisms by which CR causes large inter-individual variability in the rates of weight loss and how exercise may influence weight loss and weight loss maintenance.Trial registrationClinicalTrials.gov NCT00099151.Leanne M. Redman, Leonie K. Heilbronn, Corby K. Martin, Lilian de Jonge, Donald A. Williamson, James P. Delany, Eric Ravussin, for the Pennington CALERIE tea

Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals

This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2 The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio

REDUCE (Reviewing long-term antidepressant use by careful monitoring in everyday practice) internet and telephone support to people coming off long-term antidepressants: protocol for a randomised controlled trial.

BACKGROUND: Around one in ten adults take antidepressants for depression in England, and their long-term use is increasing. Some need them to prevent relapse, but 30-50% could possibly stop them without relapsing and avoid adverse effects and complications of long-term use. However, stopping is not always easy due to withdrawal symptoms and a fear of relapse of depression. When general practitioners review patients on long-term antidepressants and recommend to those who are suitable to stop the medication, only 6-8% are able to stop. The Reviewing long-term antidepressant use by careful monitoring in everyday practice (REDUCE) research programme aims to identify safe and cost-effective ways of helping patients taking long-term antidepressants taper off treatment when appropriate. METHODS: Design: REDUCE is a two-arm, 1:1 parallel group randomised controlled trial, with randomisation clustered by participating family practices. SETTING: England and north Wales. POPULATION: patients taking antidepressants for longer than 1 year for a first episode of depression or longer than 2 years for repeated episodes of depression who are no longer depressed and want to try to taper off their antidepressant use. INTERVENTION: provision of 'ADvisor' internet programmes to general practitioners or nurse practitioners and to patients designed to support antidepressant withdrawal, plus three patient telephone calls from a psychological wellbeing practitioner. The control arm receives usual care. Blinding of patients, practitioners and researchers is not possible in an open pragmatic trial, but statistical and health economic data analysts will remain blind to allocation. OUTCOME MEASURES: the primary outcome is self-reported nine-item Patient Health Questionnaire at 6 months for depressive symptoms. SECONDARY OUTCOMES: depressive symptoms at other follow-up time points, anxiety, discontinuation of antidepressants, social functioning, wellbeing, enablement, quality of life, satisfaction, and use of health services for costs. SAMPLE SIZE: 402 patients (201 intervention and 201 controls) from 134 general practices recruited over 15-18 months, and followed-up at 3, 6, 9 and 12 months. A qualitative process evaluation will be conducted through interviews with 15-20 patients and 15-20 practitioners in each arm to explore why the interventions were effective or not, depending on the results. DISCUSSION: Helping patients reduce and stop antidepressants is often challenging for practitioners and time-consuming for very busy primary care practices. If REDUCE provides evidence showing that access to internet and telephone support enables more patients to stop treatment without increasing depression we will try to implement the intervention throughout the National Health Service, publishing practical guidance for professionals and advice for patients to follow, publicised through patient support groups. TRIAL REGISTRATION: ISRCTN:12417565. Registered on 7 October 2019

Religiosity and teen birth rate in the United States

<p>Abstract</p> <p>Background</p> <p>The children of teen mothers have been reported to have higher rates of several unfavorable mental health outcomes. Past research suggests several possible mechanisms for an association between religiosity and teen birth rate in communities.</p> <p>Methods</p> <p>The present study compiled publicly accessible data on birth rates, conservative religious beliefs, income, and abortion rates in the U.S., aggregated at the state level. Data on teen birth rates and abortion originated from the Center for Disease Control; on income, from the U.S. Bureau of the Census, and on religious beliefs, from the U.S. Religious Landscape Survey carried out by the Pew Forum on Religion and Public Life. We computed correlations and partial correlations.</p> <p>Results</p> <p>Increased religiosity in residents of states in the U.S. strongly predicted a higher teen birth rate, with r = 0.73 (p < 0.0005). Religiosity correlated negatively with median household income, with r = -0.66, and income correlated negatively with teen birth rate, with r = -0.63. But the correlation between religiosity and teen birth rate remained highly significant when income was controlled for via partial correlation: the partial correlation between religiosity and teen birth rate, controlling for income, was 0.53 (p < 0.0005). Abortion rate correlated negatively with religiosity, with r = -0.45, p = 0.002. However, the partial correlation between teen birth rate and religiosity remained high and significant when controlling for abortion rate (partial correlation = 0.68, p < 0.0005) and when controlling for both abortion rate and income (partial correlation = 0.54, p = 0.001).</p> <p>Conclusion</p> <p>With data aggregated at the state level, conservative religious beliefs strongly predict U.S. teen birth rates, in a relationship that does not appear to be the result of confounding by income or abortion rates. One possible explanation for this relationship is that teens in more religious communities may be less likely to use contraception.</p

Characteristics of children with hip displacement in cerebral palsy

<p>Abstract</p> <p>Background</p> <p>Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The dislocation can be avoided, by screening and preventive treatment of children with hips at risk. The aim of this study was to analyse the characteristics of children with CP who develop hip displacement, in order to optimise a hip surveillance programme.</p> <p>Methods</p> <p>In a total population of children with CP a standardised clinical and radiological follow-up of the hips was carried out as a part of a hip prevention programme. The present study is based on 212 children followed until 9–16 years of age.</p> <p>Results</p> <p>Of the 212 children, 38 (18%) developed displacement with Migration Percentage (MP) >40% and further 19 (9%) MP between 33 and 39%. Mean age at first registration of hip displacement was 4 years, but some hips showed MP > 40% already at two years of age. The passive range of hip motion at the time of first registration of hip displacement did not differ significantly from the findings in hips without displacement.</p> <p>The risk of hip displacement varied according to CP-subtype, from 0% in children with pure ataxia to 79% in children with spastic tetraplegia. The risk of displacement (MP > 40%) was directly related to the level of gross motor function, classified according to the gross motor function classification system, GMFCS, from 0% in children in GMFCS level I to 64% in GMFCS level V.</p> <p>Conclusion</p> <p>Hip displacement in CP often occurs already at 2–3 years of age. Range of motion is a poor indicator of hips at risk. Thus early identification and early radiographic examination of children at risk is of great importance. The risk of hip displacement varies according to both CP-subtype and GMFCS. It is sometimes not possible to determine subtype before 4 years of age, and at present several definitions and classification systems are used. GMFCS is valid and reliable from 2 years of age, and it is internationally accepted.</p> <p>We recommend a hip surveillance programme for children with CP with radiographic examinations based on the child's age and GMFCS level.</p

Long-Term Safety and Efficacy of Adalimumab in Patients With Noninfectious Intermediate Uveitis, Posterior Uveitis, or Panuveitis

PURPOSE: To evaluate long-term efficacy and safety of extended treatment with adalimumab in patients with noninfectious intermediate, posterior, or panuveitis. DESIGN: Open-label, multicenter, phase 3 extension study (VISUAL III). PARTICIPANTS: Adults who had completed a randomized, placebo-controlled phase 3 parent trial (VISUAL I or II) without treatment failure (inactive uveitis) or discontinued after meeting treatment failure criteria (active uveitis). METHODS: Patients received subcutaneous adalimumab 40 mg every other week. Data were collected for ≤362 weeks. Adverse events (AEs) were recorded until 70 days after the last dose of study drug. MAIN OUTCOME MEASURES: Main outcome measures were long-term safety and quiescence; other efficacy variables included inflammatory lesions, anterior chamber cell and vitreous haze grade, macular edema, visual acuity, and dose of uveitis-related corticosteroids. RESULTS: Of 424 patients enrolled, 67% (283/424) had active uveitis and 33% (141/424) had inactive uveitis at study entry; 60 patients subsequently met exclusion criteria, and 364 patients were included in the intent-to-treat analysis. Efficacy variables were analyzed through week 150 when approximately 50% of patients (214/424) remained in the study. The percentage of patients in quiescence increased from 34% (122/364) at week 0 to 85% (153/180) at week 150. Corticosteroid-free quiescence was achieved by 54% (66/123) and 89% (51/57) of patients with active or inactive uveitis at study entry, respectively, by week 150. Mean daily dose of corticosteroids was reduced from 9.4±17.1 mg/day at week 0 (n=359) to 1.5±3.9 mg/day at week 150 (n=181). The percentage of patients who achieved other efficacy variables increased over time for those with active uveitis at study entry and was maintained for those with inactive uveitis. The most frequently reported treatment-emergent AEs of special interest for adalimumab were infections (n=275; 78.7 events/100 patient-years); AEs and serious AEs occurred at a rate of 396 events/100 patient-years and 15 events/100 patient-years, respectively. CONCLUSIONS: Long-term treatment with adalimumab led to quiescence and reduced corticosteroid use for patients who entered VISUAL III with active uveitis and maintenance of quiescence for those with inactive uveitis. AEs were comparable to those reported in the parent trials and consistent with the known safety profile of adalimumab

Structural equation and log-linear modeling: a comparison of methods in the analysis of a study on caregivers' health

BACKGROUND: In this paper we compare the results in an analysis of determinants of caregivers' health derived from two approaches, a structural equation model and a log-linear model, using the same data set. METHODS: The data were collected from a cross-sectional population-based sample of 468 families in Ontario, Canada who had a child with cerebral palsy (CP). The self-completed questionnaires and the home-based interviews used in this study included scales reflecting socio-economic status, child and caregiver characteristics, and the physical and psychological well-being of the caregivers. Both analytic models were used to evaluate the relationships between child behaviour, caregiving demands, coping factors, and the well-being of primary caregivers of children with CP. RESULTS: The results were compared, together with an assessment of the positive and negative aspects of each approach, including their practical and conceptual implications. CONCLUSION: No important differences were found in the substantive conclusions of the two analyses. The broad confirmation of the Structural Equation Modeling (SEM) results by the Log-linear Modeling (LLM) provided some reassurance that the SEM had been adequately specified, and that it broadly fitted the data

Sexuality of Young Adults with Cerebral Palsy: Experienced Limitations and Needs

Objective of this study is to describe the problems young adults with Cerebral Palsy (CP) experience in the various stages of the sexual response cycle, and the physical and emotional obstacles they experience with sexuality. In this prospective cohort study 74 young adults (46 men; 28 women) with CP and average intelligence participated, aged 20–24 years. Twenty percent of these young adults with CP experienced anorgasmia, 80% reported physical problems with sex related to CP and 45% emotional inhibition to initiate sexual contact. In 90% of the participants, sexuality had not been discussed during the rehabilitation treatment. Many adolescents reported wanting information about the impact of CP on sexuality and reproduction (35%), about interventions (26%), tools and medicines (16%) and about problems with their partner (14%). Young adults with CP can experience various problems or challenges with sexuality. For preventing sexual difficulties and treating sexual problems, health care professionals need to proactively take the initiative to inform young people with CP about sexuality