RESUMO
BACKGROUND AND AIMS: Improving the care of decompensated cirrhosis is a significant clinical challenge. The primary aim of this trial was to assess the efficacy of a chronic disease management (CDM) model to reduce liver-related emergency admissions (LREA). The secondary aims were to assess model effects on quality-of-care and patient-reported outcomes. APPROACH AND RESULTS: The study design was a 2-year, multicenter, randomized controlled study with 1:1 allocation of a CDM model versus usual care. The study setting involved both tertiary and community care. Participants were randomly allocated following a decompensated cirrhosis admission. The intervention was a multifaceted CDM model coordinated by a liver nurse. A total of 147 participants (intervention=75, control=71) were recruited with a median Model for End-Stage Liver Disease score of 19. For the primary outcome, there was no difference in the overall LREA rate for the intervention group versus the control group (incident rate ratio 0.89; 95% CI: 0.53-1.50, p=0.666) or in actuarial survival (HR=1.14; 95% CI: 0.66-1.96, p=0.646). However, there was a reduced risk of LREA due to encephalopathy in the intervention versus control group (HR=1.87; 95% CI: 1.18-2.96, p=0.007). Significant improvement in quality-of-care measures was seen for the performance of bone density (p<0.001), vitamin D testing (p<0.001), and HCC surveillance adherence (p=0.050). For assessable participants (44/74 intervention, 32/71 controls) significant improvements in patient-reported outcomes at 3 months were seen in self-management ability and quality of life as assessed by visual analog scale (p=0.044). CONCLUSIONS: This CDM intervention did not reduce overall LREA events and may not be effective in decompensated cirrhosis for this end point.
RESUMO
OBJECTIVE: Delivering effective secondary preventive and integrated care has the potential to break the revolving-door phenomenon of frequent readmissions in patients with advanced chronic liver disease. To address this, we launched the Care Coordination of Liver Disease (CCoLD) pilot, a novel nurse-led cirrhosis clinic in Western Sydney. METHODS AND ANALYSIS: Following an index presentation to Blacktown or Mount Druitt hospitals (BMDH), patients (n = 89, matched by age, sex, and MELD-NA) were consecutively either followed up by the CCoLD clinical nurse consultant (intervention cohort) or received standard care (control cohort). Controlled evaluation of the impact of the nurse-led clinic was carried out for a 3-month period including readmission rates, survival, and cost effectiveness. RESULTS: The inaugural nurse-led clinic led to improvement in patient-level outcomes including a reduction in unplanned liver-related readmissions (2.08% for intervention cohort vs 12.2% for control cohort, p < 0.01), and mortality at 30 days (0% for intervention cohort vs 7.3% for control cohort, p = 0.03). Similar trends were observed at 90 days from index discharge. No deaths were observed in the intervention cohort as compared to the control cohort at 90 days (0% versus 7.3%, p = 0.03), while unplanned liver-related readmissions were 10.41% for the intervention cohort vs 19.5% for the control cohort (p = 0.115). Moreover, time to readmission was significantly longer in the intervention cohort, resulting in an overall cost-effective intervention. CONCLUSION: These findings highlight the significant impact of optimised care-coordination. A nurse-led clinic can deliver patient-centred, goal-directed, and cost-effective secondary prevention and care. A multicentre randomised trial for wider evaluation of these findings is warranted.
Assuntos
Papel do Profissional de Enfermagem , Readmissão do Paciente , Humanos , Cirrose Hepática/terapia , Alta do Paciente , Masculino , FemininoRESUMO
This corrects the article DOI: 10.1038/nature22800.
RESUMO
Glucagon-like peptide 1 (GLP-1) regulates glucose homeostasis through the control of insulin release from the pancreas. GLP-1 peptide agonists are efficacious drugs for the treatment of diabetes. To gain insight into the molecular mechanism of action of GLP-1 peptides, here we report the crystal structure of the full-length GLP-1 receptor bound to a truncated peptide agonist. The peptide agonist retains an α-helical conformation as it sits deep within the receptor-binding pocket. The arrangement of the transmembrane helices reveals hallmarks of an active conformation similar to that observed in class A receptors. Guided by this structural information, we design peptide agonists with potent in vivo activity in a mouse model of diabetes.
Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/química , Peptídeos/química , Peptídeos/farmacologia , Animais , Sítios de Ligação , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Humanos , Masculino , Camundongos , Modelos Moleculares , Peptídeos/metabolismo , Conformação Proteica , Ratos , Receptores de Hormônio Liberador da Corticotropina/química , Receptores de Glucagon/químicaRESUMO
Glucagon is a 29-amino-acid peptide released from the α-cells of the islet of Langerhans, which has a key role in glucose homeostasis. Glucagon action is transduced by the class B G-protein-coupled glucagon receptor (GCGR), which is located on liver, kidney, intestinal smooth muscle, brain, adipose tissue, heart and pancreas cells, and this receptor has been considered an important drug target in the treatment of diabetes. Administration of recently identified small-molecule GCGR antagonists in patients with type 2 diabetes results in a substantial reduction of fasting and postprandial glucose concentrations. Although an X-ray structure of the transmembrane domain of the GCGR has previously been solved, the ligand (NNC0640) was not resolved. Here we report the 2.5 Å structure of human GCGR in complex with the antagonist MK-0893 (ref. 4), which is found to bind to an allosteric site outside the seven transmembrane (7TM) helical bundle in a position between TM6 and TM7 extending into the lipid bilayer. Mutagenesis of key residues identified in the X-ray structure confirms their role in the binding of MK-0893 to the receptor. The unexpected position of the binding site for MK-0893, which is structurally similar to other GCGR antagonists, suggests that glucagon activation of the receptor is prevented by restriction of the outward helical movement of TM6 required for G-protein coupling. Structural knowledge of class B receptors is limited, with only one other ligand-binding site defined--for the corticotropin-releasing hormone receptor 1 (CRF1R)--which was located deep within the 7TM bundle. We describe a completely novel allosteric binding site for class B receptors, providing an opportunity for structure-based drug design for this receptor class and furthering our understanding of the mechanisms of activation of these receptors.
Assuntos
Pirazóis/metabolismo , Receptores de Glucagon/antagonistas & inibidores , Receptores de Glucagon/química , beta-Alanina/análogos & derivados , Sítio Alostérico/efeitos dos fármacos , Cristalografia por Raios X , Glucagon/metabolismo , Glucagon/farmacologia , Humanos , Ligantes , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Modelos Moleculares , Conformação Proteica/efeitos dos fármacos , Pirazóis/química , Pirazóis/farmacologia , Receptores de Hormônio Liberador da Corticotropina/química , Receptores de Hormônio Liberador da Corticotropina/metabolismo , Receptores de Glucagon/classificação , Receptores de Glucagon/metabolismo , beta-Alanina/química , beta-Alanina/metabolismo , beta-Alanina/farmacologiaRESUMO
The test methods that currently exist for the identification of thyroid hormone system-disrupting chemicals are woefully inadequate. There are currently no internationally validated in vitro assays, and test methods that can capture the consequences of diminished or enhanced thyroid hormone action on the developing brain are missing entirely. These gaps put the public at risk and risk assessors in a difficult position. Decisions about the status of chemicals as thyroid hormone system disruptors currently are based on inadequate toxicity data. The ATHENA project (Assays for the identification of Thyroid Hormone axis-disrupting chemicals: Elaborating Novel Assessment strategies) has been conceived to address these gaps. The project will develop new test methods for the disruption of thyroid hormone transport across biological barriers such as the blood-brain and blood-placenta barriers. It will also devise methods for the disruption of the downstream effects on the brain. ATHENA will deliver a testing strategy based on those elements of the thyroid hormone system that, when disrupted, could have the greatest impact on diminished or enhanced thyroid hormone action and therefore should be targeted through effective testing. To further enhance the impact of the ATHENA test method developments, the project will develop concepts for better international collaboration and development in the area of thyroid hormone system disruptor identification and regulation.
Assuntos
Disruptores Endócrinos/toxicidade , Ensaios de Triagem em Larga Escala/métodos , Hormônios Tireóideos/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Descoberta de Drogas , Disruptores Endócrinos/química , Humanos , Técnicas In Vitro , InternetRESUMO
A series of novel allosteric antagonists of the GLP-1 receptor (GLP-1R), exemplified by HTL26119, are described. SBDD approaches were employed to identify HTL26119, exploiting structural understanding of the allosteric binding site of the closely related Glucagon receptor (GCGR) (Jazayeri et al., 2016) and the homology relationships between GCGR and GLP-1R. The region around residue C3476.36b of the GLP-1R receptor represents a key difference from GCGR and was targeted for selectivity for GLP-1R.
Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Compostos Heterocíclicos/química , Regulação Alostérica/efeitos dos fármacos , Sítio Alostérico , Sequência de Aminoácidos , Desenho de Fármacos , Simulação de Acoplamento Molecular , Estrutura Molecular , Ligação Proteica , Receptores de Glucagon/antagonistas & inibidores , Transdução de Sinais , Relação Estrutura-AtividadeRESUMO
G-protein-coupled receptors (GPCRs) are the largest family of transmembrane signaling proteins in the human genome. Events in the GPCR signaling cascade have been well characterized, but the receptor composition and its membrane distribution are still generally unknown. Although there is evidence that some members of the GPCR superfamily exist as constitutive dimers or higher oligomers, interpretation of the results has been disputed, and recent studies indicate that monomeric GPCRs may also be functional. Because there is controversy within the field, to address the issue we have used total internal reflection fluorescence microscopy (TIRFM) in living cells to visualize thousands of individual molecules of a model GPCR, the M(1) muscarinic acetylcholine receptor. By tracking the position of individual receptors over time, their mobility, clustering, and dimerization kinetics could be directly determined with a resolution of approximately 30 ms and approximately 20 nm. In isolated CHO cells, receptors are randomly distributed over the plasma membrane. At any given time, approximately 30% of the receptor molecules exist as dimers, and we found no evidence for higher oligomers. Two-color TIRFM established the dynamic nature of dimer formation with M(1) receptors undergoing interconversion between monomers and dimers on the timescale of seconds.
Assuntos
Microscopia de Fluorescência/métodos , Pirenzepina/análogos & derivados , Receptor Muscarínico M1/metabolismo , Animais , Benzenossulfonatos/química , Ligação Competitiva , Células CHO , Carbocianinas/química , Membrana Celular/metabolismo , Cricetinae , Cricetulus , Corantes Fluorescentes/química , Humanos , Cinética , Espectroscopia de Ressonância Magnética , Simulação de Dinâmica Molecular , Estrutura Molecular , Antagonistas Muscarínicos/química , Antagonistas Muscarínicos/metabolismo , Antagonistas Muscarínicos/farmacologia , Pirenzepina/metabolismo , Pirenzepina/farmacologia , Multimerização Proteica , Ensaio Radioligante , Receptor Muscarínico M1/antagonistas & inibidores , Receptor Muscarínico M1/genética , Fatores de Tempo , TransfecçãoRESUMO
We present a comprehensive overview of changes in thyroxine (T4) and thyroid stimulating hormone (TSH) serum concentrations after pre-gestational, gestational and/or lactation exposures of rodents to various chemicals that affect the thyroid hormone system. We show that T4 and TSH changes consistent with the idealized view of the hypothalamic-pituitary-thyroid (HPT) feedback loop (T4 decrements accompanied by TSH increases) are observed with only a relatively small set of chemicals. Most substances affect concentrations of various thyroid hormones without increasing TSH. Studies of altered T4 concentrations after gestational exposures are limited to a relatively small set of chemicals in which pesticides, pharmaceuticals and industrial chemicals are under-represented. Our risk-of-bias analysis exposed deficits in T4/TSH analytics as a problem area. By relating patterns of T4 - TSH changes to mode-of-action (MOA) information, we found that chemicals capable of disrupting the HPT feedback frequently affected thyroid hormone synthesis, while substances that produced T4 serum decrements without accompanying TSH increases lacked this ability, but often induced liver enzyme systems responsible for the elimination of TH by glucuronidation. Importantly, a multitude of MOA leads to decrements of serum T4. The current EU approaches for identifying thyroid hormone system-disrupting chemicals, with their reliance on altered TH serum levels as indicators of a hormonal mode of action and thyroid histopathological changes as indicators of adversity, will miss chemicals that produce T4/T3 serum decreases without accompanying TSH increases. This is of concern as it may lead to a disregard for chemicals that produce developmental neurotoxicity by disrupting adequate T4/T3 supply to the brain, but without increasing TSH.
Assuntos
Hormônios Tireóideos , Animais , Feminino , Gravidez , Hormônios Tireóideos/sangue , Hormônios Tireóideos/metabolismo , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia , Tiroxina/sangue , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/patologia , Disruptores Endócrinos/toxicidade , Tireotropina/sangue , Roedores , Exposição Materna/efeitos adversos , Ratos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismoRESUMO
Pesticides are omnipresent, and they pose significant environmental and health risks. Translational studies indicate that acute exposure to high pesticide levels is detrimental, and prolonged contact with low concentrations of pesticides, as single and cocktail, could represent a risk factor for multi-organ pathophysiology, including the brain. Within this research template, we focus on pesticides' impact on the blood-brain barrier (BBB) and neuroinflammation, physical and immunological borders for the homeostatic control of the central nervous system (CNS) neuronal networks. We examine the evidence supporting a link between pre- and postnatal pesticide exposure, neuroinflammatory responses, and time-depend vulnerability footprints in the brain. Because of the pathological influence of BBB damage and inflammation on neuronal transmission from early development, varying exposures to pesticides could represent a danger, perhaps accelerating adverse neurological trajectories during aging. Refining our understanding of how pesticides influence brain barriers and borders could enable the implementation of pesticide-specific regulatory measures directly relevant to environmental neuroethics, the exposome, and one-health frameworks.
Assuntos
Barreira Hematoencefálica , Praguicidas , Humanos , Praguicidas/toxicidade , Doenças Neuroinflamatórias , Encéfalo/patologia , Sistema Nervoso Central , Inflamação/induzido quimicamenteRESUMO
INTRODUCTION: Gestational diabetes is an intolerance to glucose diagnosed during pregnancy that goes away postpartum. Gestational diabetes may result in outcomes such as birth trauma, increased rates of cesarean sections, and macrosomia. This study aims to determine the outcomes of gestational diabetes mellitus (GDM) on maternal and fetal health in a tertiary care hospital setting. MATERIALS AND METHODS: This is a retrospective study of 52 patients who presented with gestational diabetes mellitus (GDM) and were treated at Tentishev Satkynbai Memorial Asian Medical Institute, Kyrgyzstan, between April 2021 and January 2022. The information was taken from the medical records of the patients. The baby's age, the mother's body mass index (BMI), history of pregnancy, deaths, birth weight, and the number of births were all taken into account. RESULTS: Out of all the cases during the study period at the Tentishev Satkynbai Memorial Asian Medical Institute, Kyrgyzstan, 52 were found to be complicated with gestational diabetes mellitus, which is 2.7% of the total deliveries. There was a significant difference found among both study groups in gestational age and history of GDM. The neonatal intensive care unit (NICU) admission rate of neonates born to GDM mothers was found to be significant with a difference of 10.9% (p < 0.0003), which is higher compared to the control group. CONCLUSION: Incidences of macrosomia, NICU admissions of preterm babies, and large for gestational age (LGA) and increased rates of hypertensive disorders were found among GDM pregnancies compared to control cases. The study shows higher rates of maternal and fetal/neonatal complications in females with GDM.
RESUMO
The recently encountered severe acute respiratory syndrome coronavirus 2 creates huge predicaments among various countries. Lack of specific treatment of COVID-19 disease demands urgency in drug design against SARS-CoV-2 targets. Nigella sativa the miraculous herb native to South and Southwest Asia and belonging to the family Ranunculaceae, due to its beneficial bioactive properties, was used by us for performing in silico study to analyze the potential of its compounds so that they can target and inhibit SARS-COV-2 proteins including its main protease, the papain-like protease, its helicase, and also the RNA-dependent RNApolymerase, RNA-binding protein, Endoribonuclease, receptor-binding domain, and the RNA-binding domain of nucleocapsid phosphoprotein. The procedure of molecular docking was done with the help of AutoDock-Vina 1.1.2. and along with it the ADMET properties of the best suited ligands were found and Lipinski screening was performed. Among 58 ligands screened, various compounds showed binding energy less than the standard drug chloroquine. Three compounds alpha-hederin, rutin, and nigellamine A2 had the least binding energy with the specific SARS-Cov-2 proteins suggesting their best potential as SARS-CoV-2 inhibitor. Hence, in the future, studies including the in vitro and also the in vivo studies can be carried out for analyzing their true potential and encourage use of nutraceuticals like Nigella sativa to inhibit this virus.
Assuntos
SARS-CoV-2RESUMO
To support a mixture risk assessment with a focus on male reproductive health, we conducted a systematic review of associations between bisphenol A (BPA) exposures and declines in semen quality, based on animal and epidemiological studies. Contrary to a widely held view that there is "conflicting" evidence of such associations, our review and confidence rating approach reveals that animal studies provide convincing evidence of declines of semen quality after gestational BPA exposures. Many of the reported negative findings can be attributed to deficiencies in study sensitivity, insufficient control of background contamination and probable confounding through hormonal interference due to the use of soy-containing diets. We did not evaluate animal studies of adult BPA exposures. Divergent findings in "medium to high" and "medium" confidence epidemiological studies can be explained in terms of differences in exposure conditions. We attempted the estimation of a BPA reference dose based on animal studies. Due to variations in the no-observed adverse effect levels (NOAELs) in high confidence studies, possible reference doses ranged from 0.0001 to 0.0099 µg/kg/d. In choosing 0.003 µg/kg/d we struck a balance between caution suggested by studies at the lower end of the doses and the weight of evidence from studies with higher NOAELs. This weighting was motivated by the intended use of the value in a mixture risk assessment which meant arriving at a reasonable estimate of BPA exposures likely without effects on semen quality. We realise that our approach does not conform with the standards necessary for deriving tolerable daily intakes (TDIs) for single chemical exposures, which is not our interest here. BPA exposures currently experienced by European populations and beyond are in excess of 0.003 µg/kg/d and even fall in the range where some epidemiological studies observed effects on semen quality as a result of BPA exposures in adulthood.
Assuntos
Compostos Benzidrílicos , Análise do Sêmen , Animais , Masculino , Fenóis/toxicidade , Medição de RiscoRESUMO
A naturally occurring ACTH receptor [melanocortin 2 receptor (MC2R)] mutation (F278C) has been identified in a subject with ACTH-independent Cushing's syndrome. Functional characterization of this mutant receptor reveals that it is associated with elevated basal cAMP accumulation when compared with wild-type receptor-expressing cell lines. Dose responsiveness is similar between wild-type and mutant receptors in cell lines expressing similar numbers of binding sites. In view of the location of this mutation in the C-terminal tail of the MC2R, desensitization and internalization were investigated and found to be impaired. Inhibition of protein kinase A by H89 blocks wild-type MC2R desensitization and also results in increased basal activity, as does alanine substitution of Ser 280 in the C-terminal tail. Alanine substitution of Ser 208, the consensus protein kinase A phosphorylation target in the third cytoplasmic loop also results in a reduction in desensitization without significant change in basal activity or internalization. These findings suggest a novel mechanism is involved in the apparently constitutive activation of the MC2R in which failure of desensitization appears to be associated with enhanced basal receptor activity.
Assuntos
Mutação , Receptores da Corticotropina/genética , Receptores da Corticotropina/metabolismo , Córtex Suprarrenal , Hormônio Adrenocorticotrópico/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Alanina , Animais , Linhagem Celular , Síndrome de Cushing/genética , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Expressão Gênica , Humanos , Radioisótopos do Iodo , Cinética , Camundongos , Fosforilação , Receptor Tipo 2 de Melanocortina , Receptores da Corticotropina/efeitos dos fármacos , Serina , Transdução de Sinais , Relação Estrutura-Atividade , TransfecçãoRESUMO
Research into the functions and mechanisms of action of the melanocortin 2 receptor (MC2R) has been severely hampered by difficulties in expressing this gene in heterologous cells. This probably arises because of the need for a cofactor for cell surface expression. Using either the Y1 cell line that expresses endogenous MC2R or the Y6 cell line that expresses this putative expression factor, we have explored the mechanisms of desensitization and internalization after agonist stimulation. Protein kinase A dependence of desensitization has been demonstrated, although internalization is apparently independent of this kinase and dependent on a G protein receptor kinase. Possible underlying reasons for this paradox are discussed.
Assuntos
Receptores da Corticotropina/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Animais , Linhagem Celular , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Endocitose/fisiologia , Humanos , Receptor Tipo 2 de Melanocortina , Receptores da Corticotropina/genéticaRESUMO
OBJECTIVE: To examine the potential impact of banning tobacco displays and ads at the point of sale (POS) on youth outcomes. METHODS: An interactive virtual convenience store was created with scenarios in which the tobacco product display at the POS was either openly visible (status quo) or enclosed behind a cabinet (display ban), and tobacco ads in the store were either present or absent. A national convenience sample of 1216 youth aged 13 to 17 who were either smokers or nonsmokers susceptible to smoking participated in the study. Youth were randomized to 1 of 6 virtual store conditions and given a shopping task to complete in the virtual store. During the shopping task, we tracked youth's attempts to purchase tobacco products. Subsequently, youth completed a survey that assessed their perceptions about the virtual store and perceptions about the ease of buying cigarettes from the virtual store. RESULTS: Compared with youth in the status quo condition, youth in the display ban condition were less aware that tobacco products were for sale (32.0% vs 85.2%) and significantly less likely to try purchasing tobacco products in the virtual store (odds ratio = 0.30, 95% confidence interval = 0.13-0.67, P < .001). Banning ads had minimal impact on youth's purchase attempts. CONCLUSIONS: Policies that ban tobacco product displays at the POS may help reduce youth smoking by deterring youth from purchasing tobacco products at retail stores.
Assuntos
Publicidade/métodos , Comércio/métodos , Fumar/psicologia , Produtos do Tabaco , Interface Usuário-Computador , Adolescente , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Prevenção do Hábito de Fumar , Indústria do Tabaco/métodosRESUMO
G protein-coupled receptors (GPCRs) are one of the most important target classes in the central nervous system (CNS) drug discovery, however the fact they are integral membrane proteins and are unstable when purified out of the cell precludes them from a wide range of structural and biophysical techniques that are used for soluble proteins. In this study we demonstrate how protein engineering methods can be used to identify mutations which can both increase the thermostability of receptors, when purified in detergent, as well as biasing the receptor towards a specific physiologically relevant conformational state. We demonstrate this method for the adenosine A(2A) receptor and muscarinic M(1) receptor. The resultant stabilised receptors (known as StaRs) have a pharmacological profile consistent with the inverse agonist conformation. The stabilised receptors can be purified in large quantities, whilst retaining correct folding, thus generating reagents suitable for a broad range of structural and biophysical studies. In the case of the A(2A)-StaR we demonstrate that surface plasmon resonance can be used to profile the association and dissociation rates of a range of antagonists, a technique that can be used to improve the in vivo efficacy of receptor antagonists.