RESUMEN
Metabolic homeostasis in mammals is tightly regulated by the complementary actions of insulin and glucagon. The secretion of these hormones from pancreatic ß-cells and α-cells, respectively, is controlled by metabolic, endocrine, and paracrine regulatory mechanisms and is essential for the control of blood levels of glucose. The deregulation of these mechanisms leads to various pathologies, most notably type 2 diabetes, which is driven by the combined lesions of impaired insulin action and a loss of the normal insulin secretion response to glucose. Glucose stimulates insulin secretion from ß-cells in a bi-modal fashion, and new insights about the underlying mechanisms, particularly relating to the second or amplifying phase of this secretory response, have been recently gained. Other recent work highlights the importance of α-cell-produced proglucagon-derived peptides, incretin hormones from the gastrointestinal tract and other dietary components, including certain amino acids and fatty acids, in priming and potentiation of the ß-cell glucose response. These advances provide a new perspective for the understanding of the ß-cell failure that triggers type 2 diabetes.
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Diabetes Mellitus Tipo 2/fisiopatología , Glucosa/metabolismo , Homeostasis , Secreción de Insulina , Células Secretoras de Insulina/fisiología , Animales , Humanos , Células Secretoras de Insulina/citologíaRESUMEN
The pancreatic hormone glucagon activates the glucagon receptor (GCGR), a class B seven-transmembrane G protein-coupled receptor that couples to the stimulatory heterotrimeric G protein and provokes PKA-dependent signaling cascades vital to hepatic glucose metabolism and islet insulin secretion. Glucagon-stimulation also initiates recruitment of the endocytic adaptors, ßarrestin1 and ßarrestin2, which regulate desensitization and internalization of the GCGR. Unlike many other G protein-coupled receptors, the GCGR expressed at the plasma membrane is constitutively ubiquitinated and upon agonist-activation, internalized GCGRs are deubiquitinated at early endosomes and recycled via Rab4-containing vesicles. Herein we report a novel link between the ubiquitination status and signal transduction mechanism of the GCGR. In the deubiquitinated state, coupling of the GCGR to Gs is diminished, while binding to ßarrestin is enhanced with signaling biased to a ßarrestin1-dependent p38 mitogen activated protein kinase (MAPK) pathway. This ubiquitin-dependent signaling bias arises through the modification of lysine333 (K333) on the cytoplasmic face of transmembrane helix V. Compared with the GCGR-WT, the mutant GCGR-K333R has impaired ubiquitination, diminished G protein coupling, and PKA signaling but unimpaired potentiation of glucose-stimulated-insulin secretion in response to agonist-stimulation, which involves p38 MAPK signaling. Both WT and GCGR-K333R promote the formation of glucagon-induced ßarrestin1-dependent p38 signaling scaffold that requires canonical upstream MAPK-Kinase3, but is independent of Gs, Gi, and ßarrestin2. Thus, ubiquitination/deubiquitination at K333 in the GCGR defines the activation of distinct transducers with the potential to influence various facets of glucagon signaling in health and disease.
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Glucagón , Receptores de Glucagón , Ubiquitinación , Glucagón/metabolismo , Glucosa/metabolismo , Hígado/metabolismo , Receptores de Glucagón/genética , Receptores de Glucagón/metabolismo , Humanos , Células HEK293RESUMEN
The incretin axis is an essential component of postprandial insulin secretion and glucose homeostasis. There are two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which exert multiple actions throughout the body. A key cellular target for the incretins are pancreatic ß-cells, where they potentiate nutrient-stimulated insulin secretion. This feature of incretins has made this system an attractive target for therapeutic interventions aimed at controlling glycemia. Here, we discuss the role of GIP in both ß-cells and α-cells within the islet, to stimulate insulin and glucagon secretion, respectively. Moreover, we discuss how glucagon secretion from α-cells has important insulinotropic actions in ß-cells through an axis termed α- to ß-cell communication. These recent advances have elevated the potential of GIP and glucagon as a therapeutic targets, coinciding with emerging compounds that pharmacologically leverage the actions of these two peptides in the context of diabetes and obesity.
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Polipéptido Inhibidor Gástrico , Glucagón , Secreción de Insulina , Islotes Pancreáticos , Animales , Humanos , Polipéptido Inhibidor Gástrico/metabolismo , Glucagón/metabolismo , Péptido 1 Similar al Glucagón/metabolismo , Células Secretoras de Glucagón/metabolismo , Incretinas/metabolismo , Insulina/metabolismo , Secreción de Insulina/fisiología , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/efectos de los fármacosRESUMEN
STUDY OBJECTIVE: Identification of HIV remains a critical health priority for which emergency departments (EDs) are a central focus. The comparative cost-effectiveness of various HIV screening strategies in EDs remains largely unknown. The goal of this study was to compare programmatic costs and cost-effectiveness of nontargeted and 2 forms of targeted opt-out HIV screening in EDs using results from a multicenter, pragmatic randomized clinical trial. METHODS: This economic evaluation was nested in the HIV Testing Using Enhanced Screening Techniques in Emergency Departments (TESTED) trial, a multicenter pragmatic clinical trial of different ED-based HIV screening strategies conducted from April 2014 through January 2016. Patients aged 16 years or older, with normal mental status and not critically ill, or not known to be living with HIV were randomized to 1 of 3 HIV opt-out screening approaches, including nontargeted, enhanced targeted, or traditional targeted, across 4 urban EDs in the United States. Each screening method was fully integrated into routine emergency care. Direct programmatic costs were determined using actual trial results, and time-motion assessment was used to estimate personnel activity costs. The primary outcome was newly diagnosed HIV. Total annualized ED programmatic costs by screening approach were calculated using dollars adjusted to 2023 as were costs per patient newly diagnosed with HIV. One-way and multiway sensitivity analyses were performed. RESULTS: The trial randomized 76,561 patient visits, resulting in 14,405 completed HIV tests, and 24 (0.2%) new diagnoses. Total annualized new diagnoses were 12.9, and total annualized costs for nontargeted, enhanced targeted, and traditional targeted screening were $111,861, $88,629, and $70,599, respectively. Within screening methods, costs per new HIV diagnoses were $20,809, $23,554, and $18,762, respectively. Enhanced targeted screening incurred higher costs but with similar annualized new cases detected compared with traditional targeted screening. Nontargeted screening yielded an incremental cost-effectiveness ratio of $25,586 when compared with traditional targeted screening. Results were most sensitive to HIV prevalence and costs of HIV tests. CONCLUSION: Nontargeted HIV screening was more costly than targeted screening largely due to an increased number of HIV tests performed. Each HIV screening strategy had similar within-strategy costs per new HIV diagnosis with traditional targeted screening yielding the lowest cost per new diagnosis. For settings with budget constraints or very low HIV prevalences, the traditional targeted approach may be preferred; however, given only a slightly higher cost per new HIV diagnosis, ED settings looking to detect the most new cases may prefer nontargeted screening.
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Análisis Costo-Beneficio , Servicio de Urgencia en Hospital , Infecciones por VIH , Tamizaje Masivo , Humanos , Servicio de Urgencia en Hospital/economía , Infecciones por VIH/diagnóstico , Infecciones por VIH/economía , Tamizaje Masivo/economía , Tamizaje Masivo/métodos , Femenino , Adulto , Masculino , Estados Unidos , Persona de Mediana Edad , Prueba de VIH/economía , Prueba de VIH/métodos , Adulto JovenRESUMEN
The peptide hormone glucagon, discovered in late 1922, is secreted from pancreatic alpha cells and is an essential regulator of metabolic homeostasis. This review summarises experiences since the discovery of glucagon regarding basic and clinical aspects of this hormone and speculations on the future directions for glucagon biology and glucagon-based therapies. The review was based on the international glucagon conference, entitled 'A hundred years with glucagon and a hundred more', held in Copenhagen, Denmark, in November 2022. The scientific and therapeutic focus of glucagon biology has mainly been related to its role in diabetes. In type 1 diabetes, the glucose-raising properties of glucagon have been leveraged to therapeutically restore hypoglycaemia. The hyperglucagonaemia evident in type 2 diabetes has been proposed to contribute to hyperglycaemia, raising questions regarding underlying mechanism and the importance of this in the pathogenesis of diabetes. Mimicry experiments of glucagon signalling have fuelled the development of several pharmacological compounds including glucagon receptor (GCGR) antagonists, GCGR agonists and, more recently, dual and triple receptor agonists combining glucagon and incretin hormone receptor agonism. From these studies and from earlier observations in extreme cases of either glucagon deficiency or excess secretion, the physiological role of glucagon has expanded to also involve hepatic protein and lipid metabolism. The interplay between the pancreas and the liver, known as the liver-alpha cell axis, reflects the importance of glucagon for glucose, amino acid and lipid metabolism. In individuals with diabetes and fatty liver diseases, glucagon's hepatic actions may be partly impaired resulting in elevated levels of glucagonotropic amino acids, dyslipidaemia and hyperglucagonaemia, reflecting a new, so far largely unexplored pathophysiological phenomenon termed 'glucagon resistance'. Importantly, the hyperglucagonaemia as part of glucagon resistance may result in increased hepatic glucose production and hyperglycaemia. Emerging glucagon-based therapies show a beneficial impact on weight loss and fatty liver diseases and this has sparked a renewed interest in glucagon biology to enable further pharmacological pursuits.
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Diabetes Mellitus Tipo 2 , Hiperglucemia , Enfermedad del Hígado Graso no Alcohólico , Humanos , Glucagón/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucosa/metabolismo , Hiperglucemia/metabolismo , AminoácidosRESUMEN
The endosomal sorting complexes required for transport (ESCRTs) are essential for multiple membrane modeling and membrane-independent cellular processes. Here we describe six unrelated individuals with de novo missense variants affecting the ATPase domain of VPS4A, a critical enzyme regulating ESCRT function. Probands had structural brain abnormalities, severe neurodevelopmental delay, cataracts, growth impairment, and anemia. In cultured cells, overexpression of VPS4A mutants caused enlarged endosomal vacuoles resembling those induced by expression of known dominant-negative ATPase-defective forms of VPS4A. Proband-derived fibroblasts had enlarged endosomal structures with abnormal accumulation of the ESCRT protein IST1 on the limiting membrane. VPS4A function was also required for normal endosomal morphology and IST1 localization in iPSC-derived human neurons. Mutations affected other ESCRT-dependent cellular processes, including regulation of centrosome number, primary cilium morphology, nuclear membrane morphology, chromosome segregation, mitotic spindle formation, and cell cycle progression. We thus characterize a distinct multisystem disorder caused by mutations affecting VPS4A and demonstrate that its normal function is required for multiple human developmental and cellular processes.
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ATPasas Asociadas con Actividades Celulares Diversas/genética , Complejos de Clasificación Endosomal Requeridos para el Transporte/genética , Mutación Missense , Trastornos del Neurodesarrollo/genética , ATPasas de Translocación de Protón Vacuolares/genética , Alelos , Animales , Encéfalo/anomalías , Ciclo Celular , Centrosoma/metabolismo , Endosomas/metabolismo , Fibroblastos/metabolismo , Genómica , Células HEK293 , Células HeLa , Humanos , Ratones , Neuronas/metabolismo , Dominios Proteicos , Transporte de Proteínas , Huso Acromático/metabolismoRESUMEN
OBJECTIVES: This study aimed to estimate the cost-effectiveness of remdesivir, the first novel therapeutic to receive Emergency Use Authorization for the treatment of hospitalized patients with COVID-19, and identify key drivers of value to guide future pricing and reimbursement efforts. METHODS: A Markov model evaluated the cost-effectiveness of remdesivir in patients hospitalized with COVID-19 from a US healthcare sector perspective. A lifetime time horizon captured potential long-term costs and outcomes. Model outcomes included discounted total costs, life-years, and quality-adjusted life-years (QALYs). Remdesivir was modeled as an addition to standard of care and compared with standard of care alone, including dexamethasone for patients requiring respiratory support. COVID-19 hospitalizations were assumed to be reimbursed through a single payment based on the respiratory support received alongside a remdesivir carveout payment in the base case. Sensitivity and scenario analyses identified key drivers. RESULTS: At a unit price of $520 per vial and assuming no survival benefit with remdesivir, the incremental cost-effectiveness was $298 200/QALY for patients with moderate to severe COVID-19 and $1 847 000/QALY for patients with mild COVID-19. Although current data do not support a survival benefit, if one was assumed, the cost-effectiveness estimate was $50 100/QALY for the moderate to severe population and $103 400/QALY for the mild population. Another key driver included the hospitalization payment structure (per diem vs bundled payment). CONCLUSIONS: With the current evidence available, remdesivir's price is too high to align with its expected health gains for hospitalized patients with COVID-19. Results from this study provide a rationale for iterative health technology assessment.
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Tratamiento Farmacológico de COVID-19 , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/uso terapéutico , Alanina/análogos & derivados , Análisis Costo-Beneficio , Humanos , Años de Vida Ajustados por Calidad de VidaRESUMEN
Health technology assessment (HTA) has been growing in use over the past 40 years, especially in its impact on decisions regarding the reimbursement, adoption, and use of new drugs, devices, and procedures. In countries or jurisdictions with "pluralistic" healthcare systems, there are multiple payers or sectors, each of which could potentially benefit from HTA. Nevertheless, a single HTA, conducted centrally, may not meet the needs of these different actors, who may have different budgets, current standards of care, populations to serve, or decision-making processes. This article reports on the research conducted by an ISPOR Health Technology Assessment Council Working Group established to examine the specific challenges of conducting and using HTA in countries with pluralistic healthcare systems. The Group used its own knowledge and expertise, supplemented by a narrative literature review and survey of US payers, to identify existing challenges and any initiatives taken to address them. We recommend that countries with pluralistic healthcare systems establish a national focus for HTA, develop a uniform set of HTA methods guidelines, ensure that HTAs are produced in a timely fashion, facilitate the use of HTA in the local setting, and develop a framework to encourage transparency in HTA. These efforts can be enhanced by the development of good practice guidance from ISPOR or similar groups and increased training to facilitate local use of HTA.
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Presupuestos , Evaluación de la Tecnología Biomédica , Atención a la Salud , Humanos , Evaluación de la Tecnología Biomédica/métodosRESUMEN
Flow cytometry is widely used within the manufacturing of cell and gene therapies to measure and characterise cells. Conventional manual data analysis relies heavily on operator judgement, presenting a major source of variation that can adversely impact the quality and predictive potential of therapies given to patients. Computational tools have the capacity to minimise operator variation and bias in flow cytometry data analysis; however, in many cases, confidence in these technologies has yet to be fully established mirrored by aspects of regulatory concern. Here, we employed synthetic flow cytometry datasets containing controlled population characteristics of separation, and normal/skew distributions to investigate the accuracy and reproducibility of six cell population identification tools, each of which implement different unsupervised clustering algorithms: Flock2, flowMeans, FlowSOM, PhenoGraph, SPADE3 and SWIFT (density-based, k-means, self-organising map, k-nearest neighbour, deterministic k-means, and model-based clustering, respectively). We found that outputs from software analysing the same reference synthetic dataset vary considerably and accuracy deteriorates as the cluster separation index falls below zero. Consequently, as clusters begin to merge, the flowMeans and Flock2 software platforms struggle to identify target clusters more than other platforms. Moreover, the presence of skewed cell populations resulted in poor performance from SWIFT, though FlowSOM, PhenoGraph and SPADE3 were relatively unaffected in comparison. These findings illustrate how novel flow cytometry synthetic datasets can be utilised to validate a range of automated cell identification methods, leading to enhanced confidence in the data quality of automated cell characterisations and enumerations.
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Análisis de Datos , Programas Informáticos , Algoritmos , Análisis por Conglomerados , Citometría de Flujo/métodos , Terapia Genética , Humanos , Reproducibilidad de los ResultadosRESUMEN
Introduction: Carbapenem-resistant organisms (CROs) present a serious public health problem. Limited treatment options has led to increased use of colistin and polymyxin. Since 2014, the US Food and Drug Administration approved 4 new beta-lactam beta-lactamase inhibitor (BLBLI) combination antibiotics with activity against CROs. These new antibiotics have been shown to be more effective and less toxic than colistin and polymyxin but are considerably more expensive. This study evaluated the cost-effectiveness of the new BLBLIs versus colistin-based therapy for the treatment of CROs. Methods: A decision-tree microsimulation model was used to evaluate the cost effectiveness of the new BLBLIs versus colistin-based therapy for the treatment of CROs. Treatment groups differed in risk of mortality and risk of an acute kidney injury (AKI). The relative risk of mortality was determined by creating a meta-analysis comparing new BLBLIs to colistin. Cost inputs included medication costs and the cost to treat an AKI. The primary outcomes include quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). Model inputs included: clinical outcomes and adverse events (30-day mortality and AKI); cost of treatment and adverse drug events; and health utilities. A 3% discount was applied for outcomes. A lifetime horizon was used from the perspective of the US healthcare system with a willingness-to-pay (WTP) threshold of $100 000. A sensitivity analysis was done to incorporate uncertainty. Results: The meta-analysis found the treatment with a new BLBLI was associated with a 50% decrease in the relative risk of 30-day mortality compared to colistin (RR 0.47, 95% CI 0.25-0.88). Treatment with a new BLBLI cost $16 200 and produced 11.5 QALYs, on average. The average colistin based regimen cost $3500 and produced 8.3 QALYs. The new BLBLIs were determined to be cost-effective with an ICER of $3900 per QALY gained. Treatment with a BLBLI remained cost-effective under all uncertainty scenarios tested. Conclusion: New BLBLIs are cost-effective compared to colistin for the treatment of CROs and are associated with improved mortality and fewer AKI events. The use of colistin should be reserved for cases where new BLBLIs are not available or there is documented resistance to these new antibiotics.
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The insulinotropic actions of glucagon-like peptide 1 receptor (GLP-1R) in ß-cells have made it a useful target to manage type 2 diabetes. Metabolic stress reduces ß-cell sensitivity to GLP-1, yet the underlying mechanisms are unknown. We hypothesized that Glp1r expression is heterogeneous among ß-cells and that metabolic stress decreases the number of GLP-1R-positive ß-cells. Here, analyses of publicly available single-cell RNA-Seq sequencing (scRNASeq) data from mouse and human ß-cells indicated that significant populations of ß-cells do not express the Glp1r gene, supporting heterogeneous GLP-1R expression. To check these results, we used complementary approaches employing FACS coupled with quantitative RT-PCR, a validated GLP-1R antibody, and flow cytometry to quantify GLP-1R promoter activity, gene expression, and protein expression in mouse α-, ß-, and δ-cells. Experiments with Glp1r reporter mice and a validated GLP-1R antibody indicated that >90% of the ß-cells are GLP-1R positive, contradicting the findings with the scRNASeq data. α-cells did not express Glp1r mRNA and δ-cells expressed Glp1r mRNA but not protein. We also examined the expression patterns of GLP-1R in mouse models of metabolic stress. Multiparous female mice had significantly decreased ß-cell Glp1r expression, but no reduction in GLP-1R protein levels or GLP-1R-mediated insulin secretion. These findings suggest caution in interpreting the results of scRNASeq for low-abundance transcripts such as the incretin receptors and indicate that GLP-1R is widely expressed in ß-cells, absent in α-cells, and expressed at the mRNA, but not protein, level in δ-cells.
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Receptor del Péptido 1 Similar al Glucagón/genética , Células Secretoras de Insulina/metabolismo , Animales , Células Cultivadas , Expresión Génica , Receptor del Péptido 1 Similar al Glucagón/análisis , Humanos , Ratones , Ratones Endogámicos C57BL , Análisis de la Célula IndividualRESUMEN
Automated flow cytometry (FC) data analysis tools for cell population identification and characterization are increasingly being used in academic, biotechnology, pharmaceutical, and clinical laboratories. The development of these computational methods is designed to overcome reproducibility and process bottleneck issues in manual gating, however, the take-up of these tools remains (anecdotally) low. Here, we performed a comprehensive literature survey of state-of-the-art computational tools typically published by research, clinical, and biomanufacturing laboratories for automated FC data analysis and identified popular tools based on literature citation counts. Dimensionality reduction methods ranked highly, such as generic t-distributed stochastic neighbor embedding (t-SNE) and its initial Matlab-based implementation for cytometry data viSNE. Software with graphical user interfaces also ranked highly, including PhenoGraph, SPADE1, FlowSOM, and Citrus, with unsupervised learning methods outnumbering supervised learning methods, and algorithm type popularity spread across K-Means, hierarchical, density-based, model-based, and other classes of clustering algorithms. Additionally, to illustrate the actual use typically within clinical spaces alongside frequent citations, a survey issued by UK NEQAS Leucocyte Immunophenotyping to identify software usage trends among clinical laboratories was completed. The survey revealed 53% of laboratories have not yet taken up automated cell population identification methods, though among those that have, Infinicyt software is the most frequently identified. Survey respondents considered data output quality to be the most important factor when using automated FC data analysis software, followed by software speed and level of technical support. This review found differences in software usage between biomedical institutions, with tools for discovery, data exploration, and visualization more popular in academia, whereas automated tools for specialized targeted analysis that apply supervised learning methods were more used in clinical settings.
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Análisis de Datos , Programas Informáticos , Algoritmos , Análisis por Conglomerados , Citometría de Flujo , Inmunofenotipificación , Reproducibilidad de los ResultadosRESUMEN
Abronia and Mesaspis are two of the five anguid lizard genera in the subfamily Gerrhonotinae. Their members are restricted to Mesoamerica, and most have allopatric distributions. Species of Abronia are primarily arboreal and occur in cloud and seasonally dry pine-oak forests, whereas those of Mesaspis are terrestrial and inhabit mesic microhabitats of montane forests. Recent molecular studies suggest that although these genera together form a monophyletic group, neither genus is monophyletic. Here we performed a phylogenetic study of Abronia and Mesaspis based on the most comprehensive taxonomic sampling of these genera to date and double digest restriction site-associated (ddRADseq) data. Our reconstructed phylogeny differed considerably from all previously published topologies, consistently recovering multiple independent clades of arboreal and terrestrial species and Abronia and Mesaspis as non-monophyletic. Geography, rather than current taxonomy, provides the best explanation of their phylogenetic relationships. Our analyses consistently recovered two main clades, distributed on the highlands of Middle America east and west of the Isthmus of Tehuantepec, respectively, and each composed of subclades of Abronia and Mesaspis. In the former main clade, members of the subgenus Auriculabronia formed the sister taxon to the Mesaspis moreletii complex, whereas the main clade west of the Isthmus was composed of two clades with a subclade of Abronia and another of Mesaspis each (one clade on the Atlantic versant of the main mountain ranges of eastern Mexico and another one on the Sierra Madre del Sur exclusive of its Atlantic versant) and a third clade with species of the subgenera Abronia and Scopaeabronia. We discuss the taxonomic implications of our results for the classification of the examined taxa and list the morphological characters that diagnose the recovered clades. This study highlights the utility of ddRADseq data to reconstruct the evolutionary history of supraspecific vertebrate taxa.
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Caimanes y Cocodrilos/clasificación , Caimanes y Cocodrilos/genética , Lagartos/clasificación , Lagartos/genética , Filogenia , Animales , Secuencia de Bases , Bosques , Sitios Genéticos , Geografía , Homocigoto , Funciones de Verosimilitud , México , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Sirtuins are a family of proteins that regulate biological processes such as cellular stress and aging by removing posttranslational modifications (PTMs). We recently identified several novel PTMs that can be removed by sirtuin 4 (SIRT4), which is found in mitochondria. We showed that mice with a global loss of SIRT4 [SIRT4-knockout (KO) mice] developed an increase in glucose- and leucine-stimulated insulin secretion, and this was followed by accelerated age-induced glucose intolerance and insulin resistance. Because whole body SIRT4-KO mice had alterations to nutrient-stimulated insulin secretion, we hypothesized that SIRT4 plays a direct role in regulating pancreatic ß-cell function. Thus, we tested whether ß-cell-specific ablation of SIRT4 would recapitulate the elevated insulin secretion seen in mice with a global loss of SIRT4. Tamoxifen-inducible ß-cell-specific SIRT4-KO mice were generated, and their glucose tolerance and glucose- and leucine-stimulated insulin secretion were measured over time. These mice exhibited normal glucose- and leucine-stimulated insulin secretion and maintained normal glucose tolerance even as they aged. Furthermore, 832/13 ß-cells with a CRISPR/Cas9n-mediated loss of SIRT4 did not show any alterations in nutrient-stimulated insulin secretion. Despite the fact that whole body SIRT4-KO mice demonstrated an age-induced increase in glucose- and leucine-stimulated insulin secretion, our current data indicate that the loss of SIRT4 specifically in pancreatic ß-cells, both in vivo and in vitro, does not have a significant impact on nutrient-stimulated insulin secretion. These data suggest that SIRT4 controls nutrient-stimulated insulin secretion during aging by acting on tissues external to the ß-cell, which warrants further study.
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Secreción de Insulina/fisiología , Células Secretoras de Insulina/metabolismo , Proteínas Mitocondriales/metabolismo , Sirtuinas/metabolismo , Animales , Glucosa/farmacología , Intolerancia a la Glucosa/metabolismo , Resistencia a la Insulina , Islotes Pancreáticos/citología , Islotes Pancreáticos/metabolismo , Leucina/farmacología , Ratones , Ratones Noqueados , Mitocondrias/metabolismo , Nutrientes , Procesamiento Proteico-PostraduccionalRESUMEN
OBJECTIVE: To measure the association between selective serotonin reuptake inhibitor (SSRI) use and out-of-hospital ventricular arrhythmia among the pediatric and young adult population. STUDY DESIGN: Case-control study using US claims data from 2007 to 2018. Cases were subjects with at least 1 event between ages 2 and 24 years. Controls (matched 10:1 on index date, age, sex, and continuous enrollment) had no events during study period. Independent association between current SSRI use (prescription fill with continuous exposure ending on, or after, the index date) and incident out-of-hospital ventricular arrhythmia (hospitalization or emergency room encounter with primary diagnostic code for ventricular arrhythmia) was estimated using multivariable conditional logistic regression. Separate analyses were performed for pediatric (2-17 years of age) vs young adult (18-24 years of age) subjects and between citalopram/escitalopram vs other SSRIs. RESULTS: During the study period, 237 eligible cases were identified with 2370 matched controls. Cases were more likely to have government insurance and have a mental health, cardiac, or other complex chronic condition. Thirteen cases (5%) and 15 controls (<1%) had current SSRI exposure. After adjustment for mental health and chronic conditions, there was an increased odds of current SSRI use among cases compared with controls (OR 5.11, 95% CI 1.22-21.37). No difference was observed between pediatric and young adult ages, nor between citalopram/escitalopram and other SSRIs. CONCLUSIONS: These findings demonstrate increased odds of out-of-hospital ventricular arrhythmia associated with SSRI use in the pediatric and young adult population, suggesting a need for heightened awareness and ongoing monitoring of this potential adverse effect.
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Arritmias Cardíacas/epidemiología , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Adolescente , Factores de Edad , Arritmias Cardíacas/diagnóstico , Estudios de Casos y Controles , Niño , Preescolar , Citalopram/uso terapéutico , Escitalopram/uso terapéutico , Femenino , Hospitalización , Humanos , Modelos Logísticos , Masculino , Oportunidad Relativa , Factores de Riesgo , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the effect of different modalities of centralized reminder/recall (autodialer, text, mailed reminders) on increasing childhood influenza vaccination. STUDY DESIGN: Two simultaneous randomized clinical trials conducted from October 2017 to April 1, 2018, in New York State and Colorado. There were 61 931 children in New York (136 practices) and 23 845 children in Colorado (42 practices) who were randomized to different centralized reminder/recall modalities-4 arms in New York (autodialer, text, mailed, and no reminder control) and 3 arms in Colorado (autodialer, mailed, and no reminder control). The message content was similar across modalities. Up to 3 reminders were sent for intervention arms. The main outcome measure was receipt of ≥1 influenza vaccine. RESULTS: In New York, compared with the control arm (26.6%), postintervention influenza vaccination rates in the autodialer arm (28.0%) were 1.4 percentage points higher (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10), but the rates for text (27.6%) and mail (26.8%) arms were not different from controls. In Colorado, compared with the control arm (29.9%), postintervention influenza vaccination rates for the autodialer (32.9%) and mail (31.5%) arms were 3.0 percentage points (adjusted risk ratio, 1.08; 95% CI, 1.03-1.12) and 1.6 percentage points (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10) higher, respectively. Compared with the control arm, the incremental cost per additional vaccine delivered was $20 (New York) and $16 (Colorado) for autodialer messages. CONCLUSIONS: Centralized reminder/recall for childhood influenza vaccine was most effective via autodialer, less effective via mail, and not effective via text messages. The impact of each modality was modest. Compared with no reminders, the incremental cost per additional vaccine delivered was also modest for autodialer messages. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03294473 and NCT03246100.
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Programas de Inmunización/organización & administración , Vacunas contra la Influenza , Gripe Humana/prevención & control , Sistemas Recordatorios , Adolescente , Niño , Preescolar , Colorado , Humanos , Lactante , New York , Envío de Mensajes de TextoRESUMEN
New world coralsnakes of the genus Micrurus are a diverse radiation of highly venomous and brightly colored snakes that range from North Carolina to Argentina. Species in this group have played central roles in developing and testing hypotheses about the evolution of mimicry and aposematism. Despite their diversity and prominence as model systems, surprisingly little is known about species boundaries and phylogenetic relationships within Micrurus, which has substantially hindered meaningful analyses of their evolutionary history. Here we use mitochondrial genes together with thousands of nuclear genomic loci obtained via ddRADseq to study the phylogenetic relationships and population genomics of a subclade of the genus Micrurus: The M. diastema species complex. Our results indicate that prior species and species-group inferences based on morphology and color pattern have grossly misguided taxonomy, and that the M. diastema complex is not monophyletic. Based on our analyses of molecular data, we infer the phylogenetic relationships among species and populations, and provide a revised taxonomy for the group. Two non-sister species-complexes with similar color patterns are recognized, the M. distans and the M. diastema complexes, the first being basal to the monadal Micrurus and the second encompassing most North American monadal taxa. We examined all 13 species, and their respective subspecies, for a total of 24 recognized taxa in the M. diastema species complex. Our analyses suggest a reduction to 10 species, with no subspecific designations warranted, to be a more likely estimate of species diversity, namely, M. apiatus, M. browni, M. diastema, M. distans, M. ephippifer, M. fulvius, M. michoacanensis, M. oliveri, M. tener, and one undescribed species.
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Biodiversidad , Serpientes de Coral/genética , Genoma , Filogenia , Polimorfismo de Nucleótido Simple/genética , Animales , Argentina , Teorema de Bayes , Núcleo Celular/genética , ADN Mitocondrial/genética , Variación Genética , Genética de Población , Geografía , Funciones de Verosimilitud , Nucleótidos/genética , Pigmentación/genética , Análisis de Componente Principal , Especificidad de la EspecieRESUMEN
NEW FINDINGS: What is the central question of the study? Does the action of l-citrulline, which has been shown to augment performance in animals and athletes, possibly via increasing mitochondrial function, translate to obese animals, and does this improve glycaemia? What is the main finding and its importance? Chronic supplementation with l-citrulline improves not only exercise capacity, but also glycaemia in obese mice, which would be beneficial as obese individuals are at increased risk for type 2 diabetes. However, l-citrulline supplementation also caused a mild impairment in insulin signalling and insulin tolerance in obese mice. ABSTRACT: l-Citrulline is an organic α-amino acid that has been shown to have a number of salutary actions on whole-body physiology, including reducing muscle wasting and augmenting exercise and muscle performance. The latter has been suggested to arise from elevations in mitochondrial function. Because enhancing mitochondrial function has been proposed as a novel strategy to mitigate insulin resistance, our goal was to determine whether supplementation with l-citrulline could also improve glycaemia in an experimental mouse model of obesity. We hypothesized that l-citrulline treatment would improve glycaemia in obese mice, and this would be associated with elevations in skeletal muscle mitochondrial function. Ten-week-old C57BL/6J mice were fed either a low-fat (10% kcal from lard) or a high-fat (60% kcal from lard) diet, while receiving drinking water supplemented with either vehicle or l-citrulline (0.6 g l-1 ) for 15 weeks. Glucose homeostasis was assessed via glucose/insulin tolerance testing, while in vivo metabolism was assessed via indirect calorimetry, and forced exercise treadmill testing was utilized to assess endurance. As expected, obese mice supplemented with l-citrulline exhibited an increase in exercise capacity, which was associated with an improvement in glucose tolerance. Consistent with augmented mitochondrial function, we observed an increase in whole body oxygen consumption rates in obese mice supplemented with l-citrulline. Surprisingly, l-citrulline supplementation worsened insulin tolerance and reduced insulin signalling in obese mice. Taken together, although l-citrulline supplementation improves both glucose tolerance and exercise capacity in obese mice, caution must be applied with its broad use as a nutraceutical due to a potential deterioration of insulin sensitivity.
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Glucemia/efectos de los fármacos , Citrulina/farmacología , Tolerancia al Ejercicio/efectos de los fármacos , Obesidad/tratamiento farmacológico , Animales , Glucemia/metabolismo , Citrulina/uso terapéutico , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , Tolerancia al Ejercicio/fisiología , Resistencia a la Insulina/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/metabolismo , Obesidad/metabolismoRESUMEN
OBJECTIVE: To determine the costs and reimbursement associated with running a vaccine program in 5 obstetrics/gynecology practices in Colorado that had participated in a 3-year randomized, controlled trial focused on increasing vaccination in this setting. MATERIALS AND METHODS: This was a secondary analysis on costs from 5 clinics participating in a cluster-randomized controlled trial that assessed the effectiveness of a multimodal intervention to improve vaccination rates in outpatient obstetrics/gynecology clinics in central Colorado. The intervention included designation of an immunization champion within the practice, purchasing recommended vaccines for the practice, guidance on storage and management, implementing practices for routine identification of eligible patients for vaccination using the medical record, implementation of standing orders for vaccination, and vaccine administration to patients. Data on costs were gathered from office invoices, claims data, surveys and in-person observations during the course of the trial. These data incorporated supply and personnel costs for administering vaccines to individual patients that were derived from a combination of time-motion studies of staff and provider clinical activity, and practice reports, as well as costs related to maintaining the vaccination program at the practice level, which were derived from practice reports and invoices. Cost data for personnel time during visits in which vaccination was assessed and/or discussed, but no vaccine was given to the patient were also included in the main analysis. Data on practice revenue were derived from practice reimbursement records. All costs were described in 2014 dollars. The primary analysis was the proportion of costs for the program that were reimbursed, aggregated over all years of the study and combining all vaccines and practices, separated by obstetrics vs gynecology patients. RESULTS: Collectively the 5 clinics served >40,000 patient during the study period and served a population that was 16% Medicaid. Over the 3-year observation period, there were 6573 vaccination claims made collectively by the practices (4657 for obstetric patients, 1916 for gynecology patients). The most expensive component of the program was the material costs of the vaccines themselves, which ranged from a low of $9.67 for influenza vaccines, to a high of $141.40 for human papillomavirus vaccine. Staff costs for assessing and delivering vaccines during patient visits were minimal ($0.09-$1.24 per patient visit depending on the practice and whether an obstetrics or gynecology visit was being assessed) compared with staff costs for maintaining the program at a practice level (ie, assessing inventory, ordering and stocking vaccines; $0.89-$105.89 per vaccine dose given). When assessing all costs compared with all reimbursement, we found that vaccines for obstetrics patients were reimbursed at 159% of the costs over the study period, and for gynecology patients at 97% of the costs. Overall, the vaccination program was financially favorable across the practices, averaging 125% reimbursement of costs across the three study years. CONCLUSION: Providing routine vaccines to patients in the ambulatory obstetrics/gynecology setting is generally not financially prohibitive for practices, and may even be financially beneficial, though there is variability between practices that can affect the overall reimbursement margin.
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Atención Ambulatoria/economía , Atención a la Salud/economía , Ginecología/economía , Costos de la Atención en Salud , Programas de Inmunización/economía , Obstetricia/economía , Vacunas/uso terapéutico , Colorado , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/economía , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/uso terapéutico , Almacenaje de Medicamentos , Determinación de la Elegibilidad , Femenino , Humanos , Vacunas contra la Influenza/economía , Vacunas contra la Influenza/uso terapéutico , Medicaid , Vacunas contra Papillomavirus/economía , Vacunas contra Papillomavirus/uso terapéutico , Admisión y Programación de Personal , Ensayos Clínicos Controlados Aleatorios como Asunto , Mecanismo de Reembolso , Población Rural , Factores de Tiempo , Estados Unidos , Población Urbana , Vacunas/economíaRESUMEN
OBJECTIVES: To independently assess quality of care among patients who died in hospital and whose next-of-kin submitted a letter of complaint and make comparisons with matched controls. To identify whether use of a treatment escalation limitation plan (TELP) during the terminal illness was a relevant background factor. DESIGN: The study was an investigator-blinded retrospective case-note review of 42 complaints cases and 72 controls matched for age, sex, ward location and time of death. SETTING: The acute medical and surgical wards of three District General Hospitals administered by NHS Lanarkshire, Scotland. PARTICIPANTS: None. INTERVENTION: None. OUTCOME MEASURES: Quality of care: clinical 'problems', non-beneficial interventions (NBIs) and harms were evaluated using the Structured Judgment Review Method. Complaints were categorized using the Healthcare Complaints Analysis Tool. RESULTS: The event frequencies and rate ratios for clinical 'problems', NBIs and harms were consistently higher in complaint cases compared to controls. The difference was only significant for NBIs (P = 0.05). TELPs were used less frequently in complaint cases compared to controls (23.8 versus 47.2%, P = 0.013). The relationship between TELP use and the three key clinical outcomes was nonsignificant. CONCLUSIONS: Care delivered to patients at end-of-life whose next-of-kin submitted a complaint was poorer overall than among control patients when assessed independently by blinded reviewers. Regular use of a TELP in acute clinical settings has the potential to influence complaints relating to end-of-life care, but this requires further prospective study.