RESUMO
The Mouse Metabolic Phenotyping Centers (MMPCs) were founded in 2001 by the National Institutes of Health (NIH) to advance biomedical research by providing the scientific community with standardized, high-quality phenotyping services for mouse models of diabetes, obesity, and their complications. The intent is to allow researchers to take optimum advantage of the many new mouse models produced in labs and in high-throughput public efforts. The six MMPCs are located at universities around the country and perform complex metabolic tests in intact mice and hormone and analyte assays in tissues on a fee-for-service basis. Testing is subsidized by the NIH in order to reduce the barriers for mouse researchers. Although data derived from these tests belong to the researcher submitting mice or tissues, these data are archived after publication in a public database run by the MMPC Coordinating and Bioinformatics Unit. It is hoped that data from experiments performed in many mouse models of metabolic diseases, using standard protocols, will be useful in understanding the nature of these complex disorders. The current areas of expertise include energy balance and body composition, insulin action and secretion, whole-body and tissue carbohydrate and lipid metabolism, cardiovascular and renal function, and metabolic pathway kinetics. In addition to providing services, the MMPC staff provides expertise and advice to researchers, and works to develop and refine test protocols to best meet the community's needs in light of current scientific developments. Test technology is disseminated by publications and through annual courses.
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Camundongos/metabolismo , Animais , Camundongos/genética , National Institutes of Health (U.S.) , Fenótipo , Estados UnidosRESUMO
ABSTRACT: Acute pancreatitis (AP), resulting from inflammation of the pancreas, accounts for more than 300,000 US hospital discharges per year. Although glucose intolerance has been known as a complication of severe AP, this effect was thought to be transient. Recently, cohort studies and meta-analysis of 24 published studies of 1100 patients who survived one or more episodes of AP revealed that 30% to 40% of patients developed diabetes or impaired glucose tolerance within 3 to 4 years of even a single episode of AP. The National Institute of Diabetes and Digestive and Kidney Diseases funded the Type 1 Diabetes in Acute Pancreatitis Consortium (T1DAPC) to undertake a prospective observational study of the occurrence of diabetes during an AP episode or subsequently, with emphasis on type 1 diabetes. Key factors for funding T1DAPC are the increasing incidence and prevalence of AP, its association with the development of type 1 diabetes and other forms of diabetes after AP, its complications, and associated health care cost. The T1DAPC structure, governance, and research objectives are described in this article. The DREAM (Diabetes RElated to Acute pancreatitis and its Mechanisms) studies to be undertaken by the T1DAPC are described in other articles in this journal's issue.
Assuntos
Diabetes Mellitus Tipo 1 , Intolerância à Glucose , Pancreatite , Doença Aguda , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/epidemiologia , Humanos , Estudos Observacionais como Assunto , Pâncreas , Pancreatite/epidemiologia , Pancreatite/etiologia , Pancreatite/terapiaRESUMO
ABSTRACT: A data coordinating center (DCC) is a critical member of any multicenter research undertaking, and that is especially true for the Type 1 Diabetes in Acute Pancreatitis Consortium (T1DAPC). We describe how the T1DAPC DCC supports the consortium via its experience and expertise in project management, administration, financial management, regulatory compliance, scientific coordination, data management, research computing, and biostatistics and in facilitating scientific publications. The DCC's matrix management system has been extremely effective in managing all of its responsibilities. The first 16 months in the life of the T1DAPC have been dedicated to the development of its first protocol, titled Diabetes RElated to Acute pancreatitis and its Mechanisms (DREAM), addressing the institutional review board and regulatory components, developing the T1DAPC data management system, and providing training and certification of clinical center staff. As a result of its efforts, the DCC was a major contributor to the T1DAPC being able to initiate recruitment for the DREAM study in January 2022.
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Diabetes Mellitus Tipo 1 , Pancreatite , Doença Aguda , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/terapia , Humanos , Pancreatite/complicações , Pancreatite/diagnóstico , Pancreatite/terapiaRESUMO
ABSTRACT: The association between acute pancreatitis (AP) and diabetes mellitus (DM) has long been established, with the initial descriptions of AP patients presenting with DM after a bout of AP published in the 1940s and 50s. However, the potential mechanisms involved, particularly those components related to the immune system, have not been well defined. The Diabetes RElated to Acute pancreatitis and its Mechanisms (DREAM) study is a multicenter clinical study designed to understand the frequency and phenotype of DM developing after AP. This article describes one objective of the DREAM study: to determine the immunologic mechanisms of DM after AP, including the contribution of ß-cell autoimmunity. This component of the study will assess the presence of islet autoimmunity, as well as the magnitude and kinetics of the innate and adaptive immune response at enrollment and during longitudinal follow-up after 1 or more episodes of AP. Finally, DREAM will evaluate the relationship between immune features, DM development, and pancreatitis etiology and severity.
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Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Pancreatite , Doença Aguda , Diabetes Mellitus Tipo 1/complicações , Humanos , Pancreatite/complicaçõesRESUMO
OBJECTIVES: The metabolic abnormalities that lead to diabetes mellitus (DM) after an episode of acute pancreatitis (AP) have not been extensively studied. This article describes the objectives, hypotheses, and methods of mechanistic studies of glucose metabolism that comprise secondary outcomes of the DREAM (Diabetes RElated to Acute pancreatitis and its Mechanisms) Study. METHODS: Three months after an index episode of AP, participants without preexisting DM will undergo baseline testing with an oral glucose tolerance test. Participants will be followed longitudinally in three subcohorts with distinct metabolic tests. In the first and largest subcohort, oral glucose tolerance tests will be repeated 12 months after AP and annually to assess changes in ß-cell function, insulin secretion, and insulin sensitivity. In the second, mixed meal tolerance tests will be performed at 3 and 12 months, then annually, and following incident DM to assess incretin and pancreatic polypeptide responses. In the third, frequently sampled intravenous glucose tolerance tests will be performed at 3 months and 12 months to assess the first-phase insulin response and more precisely measure ß-cell function and insulin sensitivity. CONCLUSIONS: The DREAM study will comprehensively assess the metabolic and endocrine changes that precede and lead to the development of DM after AP.
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Diabetes Mellitus Tipo 1 , Hiperglicemia , Resistência à Insulina , Pancreatite , Doença Aguda , Glicemia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico , Glucose , Humanos , Hiperglicemia/complicações , Incretinas/metabolismo , Insulina/metabolismo , Polipeptídeo Pancreático , Pancreatite/complicações , Pancreatite/diagnósticoRESUMO
ABSTRACT: This core component of the Diabetes RElated to Acute pancreatitis and its Mechanisms (DREAM) study will examine the hypothesis that advanced magnetic resonance imaging (MRI) techniques can reflect underlying pathophysiologic changes and provide imaging biomarkers that predict diabetes mellitus (DM) after acute pancreatitis (AP). A subset of participants in the DREAM study will enroll and undergo serial MRI examinations using a specific research protocol. The aim of the study is to differentiate at-risk individuals from those who remain euglycemic by identifying parenchymal features after AP. Performing longitudinal MRI will enable us to observe and understand the natural history of post-AP DM. We will compare MRI parameters obtained by interrogating tissue properties in euglycemic, prediabetic, and incident diabetes subjects and correlate them with metabolic, genetic, and immunological phenotypes. Differentiating imaging parameters will be combined to develop a quantitative composite risk score. This composite risk score will potentially have the ability to monitor the risk of DM in clinical practice or trials. We will use artificial intelligence, specifically deep learning, algorithms to optimize the predictive ability of MRI. In addition to the research MRI, the DREAM study will also correlate clinical computed tomography and MRI scans with DM development.
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Diabetes Mellitus Tipo 1 , Pancreatite , Doença Aguda , Inteligência Artificial , Biomarcadores , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico , Humanos , Imageamento por Ressonância Magnética/métodos , Pancreatite/diagnóstico por imagem , Pancreatite/etiologiaRESUMO
ABSTRACT: Acute pancreatitis (AP) is a disease characterized by an acute inflammatory phase followed by a convalescent phase. Diabetes mellitus (DM) was historically felt to be a transient phenomenon related to acute inflammation; however, it is increasingly recognized as an important late and chronic complication. There are several challenges that have prevented precisely determining the incidence rate of DM after AP and understanding the underlying mechanisms. The DREAM (Diabetes RElated to Acute Pancreatitis and its Mechanisms) Study is a prospective cohort study designed to address these and other knowledge gaps to provide the evidence needed to screen for, prevent, and treat DM after AP. In the following article, we summarize literature regarding the epidemiology of DM after AP and provide the rationale and an overview of the DREAM study.
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Diabetes Mellitus Tipo 1 , Pancreatite , Doença Aguda , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/epidemiologia , Humanos , Incidência , Pancreatite/complicações , Pancreatite/epidemiologia , Estudos ProspectivosRESUMO
Preventing regain of lost weight is the most difficult challenge in the treatment of obesity. The National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop, "The Physiology of the Weight-Reduced State," on June 3 to 4, 2019, in order to explore the physiologic mechanisms of appetitive and metabolic adaptation that take place in the weight-reduced state and counter an individual's efforts to maintain reduced weight following weight loss.
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Manutenção do Peso Corporal/fisiologia , Obesidade/metabolismo , Redução de Peso/fisiologia , Metabolismo Energético/fisiologia , Humanos , National Institute of Diabetes and Digestive and Kidney Diseases (U.S.)/organização & administração , Obesidade/fisiopatologia , Obesidade/terapia , Resultado do Tratamento , Estados Unidos , Programas de Redução de Peso/métodosRESUMO
While conventional nutrition research has yielded biomarkers such as doubly labeled water for energy metabolism and 24-h urinary nitrogen for protein intake, a critical need exists for additional, equally robust biomarkers that allow for objective assessment of specific food intake and dietary exposure. Recent advances in high-throughput MS combined with improved metabolomics techniques and bioinformatic tools provide new opportunities for dietary biomarker development. In September 2018, the NIH organized a 2-d workshop to engage nutrition and omics researchers and explore the potential of multiomics approaches in nutritional biomarker research. The current Perspective summarizes key gaps and challenges identified, as well as the recommendations from the workshop that could serve as a guide for scientists interested in dietary biomarkers research. Topics addressed included study designs for biomarker development, analytical and bioinformatic considerations, and integration of dietary biomarkers with other omics techniques. Several clear needs were identified, including larger controlled feeding studies, testing a variety of foods and dietary patterns across diverse populations, improved reporting standards to support study replication, more chemical standards covering a broader range of food constituents and human metabolites, standardized approaches for biomarker validation, comprehensive and accessible food composition databases, a common ontology for dietary biomarker literature, and methodologic work on statistical procedures for intake biomarker discovery. Multidisciplinary research teams with appropriate expertise are critical to moving forward the field of dietary biomarkers and producing robust, reproducible biomarkers that can be used in public health and clinical research.
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Biomarcadores/análise , Dieta , Metabolômica/métodos , Biomarcadores/sangue , Biomarcadores/urina , Alimentos , Genômica , Humanos , Metagenômica , Fenômenos Fisiológicos da Nutrição/genética , Ciências da Nutrição/métodos , Estado Nutricional , Reprodutibilidade dos TestesRESUMO
This article addresses two topics. We provide an overview of the National Institutes of Health Mouse Metabolic Phenotyping Center (MMPC) Program. We then discuss some observations we have made during the first eight years of the Vanderbilt MMPC regarding common phenotyping practices. We include specific recommendations to improve phenotyping practices for tests of glucose tolerance and insulin action. We recommend that methods for experiments in vivo be described in manuscripts. We make specific recommendations for data presentation, interpretation, and experimental design for each test. To facilitate and maximize the exchange of scientific information, we suggest that guidelines be developed for methods used to assess glucose tolerance and insulin action in vivo.
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Glucose/metabolismo , Homeostase/fisiologia , Camundongos/genética , Animais , Técnica Clamp de Glucose , Intolerância à Glucose/genética , Teste de Tolerância a Glucose , Homeostase/genética , Hiperglicemia/metabolismo , Resistência à Insulina , Camundongos/fisiologia , National Institutes of Health (U.S.) , Fenótipo , Estados UnidosRESUMO
Human brown adipose tissue (BAT) presence, metabolic activity, and estimated mass are typically measured by imaging [18F]fluorodeoxyglucose (FDG) uptake in response to cold exposure in regions of the body expected to contain BAT, using positron emission tomography combined with X-ray computed tomography (FDG-PET/CT). Efforts to describe the epidemiology and biology of human BAT are hampered by diverse experimental practices, making it difficult to directly compare results among laboratories. An expert panel was assembled by the National Institute of Diabetes and Digestive and Kidney Diseases on November 4, 2014 to discuss minimal requirements for conducting FDG-PET/CT experiments of human BAT, data analysis, and publication of results. This resulted in Brown Adipose Reporting Criteria in Imaging STudies (BARCIST 1.0). Since there are no fully validated best practices at this time, panel recommendations are meant to enhance comparability across experiments, but not to constrain experimental design or the questions that can be asked.
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Tecido Adiposo Marrom/diagnóstico por imagem , Fluordesoxiglucose F18/metabolismo , Guias como Assunto , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Humanos , Tamanho do Órgão , Reprodutibilidade dos Testes , Estatística como AssuntoRESUMO
The beneficial effects of physical activity (PA) are well documented, yet the mechanisms by which PA prevents disease and improves health outcomes are poorly understood. To identify major gaps in knowledge and potential strategies for catalyzing progress in the field, the NIH convened a workshop in late October 2014 entitled "Understanding the Cellular and Molecular Mechanisms of Physical Activity-Induced Health Benefits." Presentations and discussions emphasized the challenges imposed by the integrative and intermittent nature of PA, the tremendous discovery potential of applying "-omics" technologies to understand interorgan crosstalk and biological networking systems during PA, and the need to establish an infrastructure of clinical trial sites with sufficient expertise to incorporate mechanistic outcome measures into adequately sized human PA trials. Identification of the mechanisms that underlie the link between PA and improved health holds extraordinary promise for discovery of novel therapeutic targets and development of personalized exercise medicine.
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Saúde , Atividade Motora , Animais , Ensaios Clínicos como Assunto , Biologia Computacional/métodos , HumanosRESUMO
BACKGROUND: Pancreatic islet transplantation can provide insulin independence and near normal glucose control in selected patients with type 1 diabetes mellitus. However, in most cases, achieving insulin independence necessitates the use of at least two donor pancreases per recipient and the rate of insulin independence may decline after transplantation. To better understand the fate of transplanted islets and the relationship between transplanted islet mass, graft function, and overall glucose homeostasis, an accurate and reproducible method of imaging islets in vivo is needed. METHODS: Recent advances in noninvasive imaging techniques such as magnetic resonance imaging, positron emission tomography, and other imaging modalities show great promise as potential tools to monitor islet number, mass, and function in the clinical setting. A recent international workshop, "Imaging the Pancreatic Beta Cell," sponsored by the National Institute of Biomedical Imaging and Bioengineering, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Juvenile Diabetes Research Foundation International focused on these emerging efforts to develop novel ways of imaging pancreatic beta cells in vivo. RESULTS: Potential clinically applicable techniques include the use of directed magnetic resonance contrast agents such as lanthanides (Ln(3+)) and manganese (Mn(2+)) or magnetic resonance imaging probes such as superparamagnetic iron oxide nanoparticles. Potential techniques for positron emission tomography imaging include the use of beta cell-specific antibodies, or pharmacologic agents such as glyburide analogs, or d-mannoheptulose. Optical imaging techniques are also being used to evaluate various aspects of beta cell metabolism including intracellular Ca(2+) flux, glucokinase activity, and insulin granular exocytosis. CONCLUSIONS: The consensus among investigators at the imaging workshop was that an accurate and reproducible in vivo measure of functional islet mass is critically needed to further the strides that have been made in both islet transplantation and diabetes research as a whole. Such measures would potentially allow the assessment of islet engraftment and the early recognition of graft loss, leading to greater improvements in islet graft survival and function.
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Diagnóstico por Imagem , Transplante das Ilhotas Pancreáticas/patologia , Humanos , Transplante das Ilhotas Pancreáticas/diagnóstico por imagem , Transplante das Ilhotas Pancreáticas/fisiologia , Medições Luminescentes , Imageamento por Ressonância Magnética , Tomografia Computadorizada de EmissãoRESUMO
Although there are many well-documented metabolic effects linked to the fructose component of a very high sugar diet, a healthy diet is also likely to contain appreciable fructose, even if confined to that found in fruits and vegetables. These normal levels of fructose are metabolized in specialized pathways that synergize with glucose at several metabolic steps. Glucose potentiates fructose absorption from the gut, while fructose catalyzes glucose uptake and storage in the liver. Fructose accelerates carbohydrate oxidation after a meal. In addition, emerging evidence suggests that fructose may also play a role in the secretion of insulin and GLP-1, and in the maturation of preadipocytes to increase fat storage capacity. Therefore, fructose undergoing its normal metabolism has the interesting property of potentiating the disposal of a dietary carbohydrate load through several routes.
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Metabolismo dos Carboidratos , Frutose/administração & dosagem , Adipócitos/metabolismo , Glicemia/metabolismo , Carboidratos da Dieta/administração & dosagem , Frutose/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Insulina/sangue , Ilhotas Pancreáticas/metabolismo , Fígado/metabolismoRESUMO
As part of a current worldwide effort to understand the physiology of human BAT (hBAT) and whether its thermogenic activity can be manipulated to treat obesity, the workshop "Exploring the Roles of Brown Fat in Humans" was convened at the National Institutes of Health on February 25-26, 2014. Presentations and discussion indicated that hBAT and its physiological roles are highly complex, and research is needed to understand the health impact of hBAT beyond thermogenesis and body weight regulation, and to define its interactions with core physiological processes like glucose homeostasis, cachexia, physical activity, bone structure, sleep, and circadian rhythms.
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Tecido Adiposo Marrom/anatomia & histologia , Tecido Adiposo Marrom/fisiologia , Peso Corporal , Metabolismo Energético , Fluordesoxiglucose F18/análise , Homeostase , Humanos , Pescoço/anatomia & histologia , Pescoço/fisiologia , Obesidade/terapia , Tomografia por Emissão de Pósitrons/métodos , TermogêneseRESUMO
Fructose and simple sugars are a substantial part of the western diet, and their influence on human health remains controversial. Clinical studies in fructose nutrition have proven very difficult to conduct and interpret. NIH and USDA sponsored a workshop on 13-14 November 2012, "Research Strategies for Fructose Metabolism," to identify important scientific questions and parameters to be considered while designing clinical studies. Research is needed to ascertain whether there is an obesogenic role for fructose-containing sugars via effects on eating behavior and energy balance and whether there is a dose threshold beyond which these sugars promote progression toward diabetes and liver and cardiovascular disease, especially in susceptible populations. Studies tend to fall into 2 categories, and design criteria for each are described. Mechanistic studies are meant to validate observations made in animals or to elucidate the pathways of fructose metabolism in humans. These highly controlled studies often compare the pure monosaccharides glucose and fructose. Other studies are focused on clinically significant disease outcomes or health behaviors attributable to amounts of fructose-containing sugars typically found in the American diet. These are designed to test hypotheses generated from short-term mechanistic or epidemiologic studies and provide data for health policy. Discussion brought out the opinion that, although many mechanistic questions concerning the metabolism of monosaccharide sugars in humans remain to be addressed experimentally in small highly controlled studies, health outcomes research meant to inform health policy should use large, long-term studies using combinations of sugars found in the typical American diet rather than pure fructose or glucose.