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1.
Diabetologia ; 67(5): 940-951, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38366195

RESUMEN

AIMS/HYPOTHESIS: The ATP-sensitive potassium (KATP) channel couples beta cell electrical activity to glucose-stimulated insulin secretion. Loss-of-function mutations in either the pore-forming (inwardly rectifying potassium channel 6.2 [Kir6.2], encoded by KCNJ11) or regulatory (sulfonylurea receptor 1, encoded by ABCC8) subunits result in congenital hyperinsulinism, whereas gain-of-function mutations cause neonatal diabetes. Here, we report a novel loss-of-function mutation (Ser118Leu) in the pore helix of Kir6.2 paradoxically associated with sulfonylurea-sensitive diabetes that presents in early adult life. METHODS: A 31-year-old woman was diagnosed with mild hyperglycaemia during an employee screen. After three pregnancies, during which she was diagnosed with gestational diabetes, the patient continued to show elevated blood glucose and was treated with glibenclamide (known as glyburide in the USA and Canada) and metformin. Genetic testing identified a heterozygous mutation (S118L) in the KCNJ11 gene. Neither parent was known to have diabetes. We investigated the functional properties and membrane trafficking of mutant and wild-type KATP channels in Xenopus oocytes and in HEK-293T cells, using patch-clamp, two-electrode voltage-clamp and surface expression assays. RESULTS: Functional analysis showed no changes in the ATP sensitivity or metabolic regulation of the mutant channel. However, the Kir6.2-S118L mutation impaired surface expression of the KATP channel by 40%, categorising this as a loss-of-function mutation. CONCLUSIONS/INTERPRETATION: Our data support the increasing evidence that individuals with mild loss-of-function KATP channel mutations may develop insulin deficiency in early adulthood and even frank diabetes in middle age. In this case, the patient may have had hyperinsulinism that escaped detection in early life. Our results support the importance of functional analysis of KATP channel mutations in cases of atypical diabetes.


Asunto(s)
Hiperinsulinismo Congénito , Diabetes Gestacional , Canales de Potasio de Rectificación Interna , Recién Nacido , Adulto , Persona de Mediana Edad , Femenino , Embarazo , Humanos , Canales de Potasio de Rectificación Interna/genética , Receptores de Sulfonilureas/genética , Receptores de Sulfonilureas/metabolismo , Hiperinsulinismo Congénito/genética , Compuestos de Sulfonilurea/uso terapéutico , Mutación/genética , Gliburida , Adenosina Trifosfato/metabolismo
2.
J Gen Intern Med ; 37(2): 439-448, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34850334

RESUMEN

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2Is) are a recent class of medication approved for the treatment of type 2 diabetes (T2D). Previous meta-analyses have quantified the benefits and harms of SGLT2Is; however, these analyses have been limited to specific outcomes and comparisons and included trials of short duration. We comprehensively reviewed the longer-term benefits and harms of SGLT2Is compared to placebo or other anti-hyperglycemic medications. METHODS: We searched PubMed, Scopus, and clinicaltrials.gov from inception to July 2019 for randomized controlled trials of minimum 52 weeks' duration that enrolled adults with T2D, compared an SGLT2I to either placebo or other anti-hyperglycemic medications, and reported at least one outcome of interest including cardiovascular risk factors, microvascular and macrovascular complications, mortality, and adverse events. We conducted random effects meta-analyses to provide summary estimates using weighted mean differences (MD) and pooled relative risks (RR). The study was registered a priori with PROSPERO (CRD42018090506). RESULTS: Fifty articles describing 39 trials (vs. placebo, n = 28; vs. other anti-hyperglycemic medication, n = 12; vs. both, n = 1) and 112,128 patients were included in our analyses. Compared to placebo, SGLT2Is reduced cardiovascular risk factors (e.g., hemoglobin A1c, MD - 0.55%, 95% CI - 0.62, - 0.49), macrovascular outcomes (e.g., hospitalization for heart failure, RR 0.70, 95% CI 0.62, 0.78), and mortality (RR 0.87, 95% CI 0.80, 0.94). Compared to other anti-hyperglycemic medications, SGLT2Is reduced cardiovascular risk factors, but insufficient data existed for other outcomes. About a fourfold increased risk of genital yeast infections for both genders was observed for comparisons vs. placebo and other anti-hyperglycemic medications. DISCUSSION: We found that SGLT2Is led to durable reductions in cardiovascular risk factors compared to both placebo and other anti-hyperglycemic medications. Reductions in macrovascular complications and mortality were only observed in comparisons with placebo, although trials comparing SGLT2Is vs. other anti-hyperglycemic medications were not designed to assess longer-term outcomes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Adulto , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Glucosa/uso terapéutico , Humanos , Masculino , Medición de Riesgo , Sodio/uso terapéutico , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico
3.
J Gen Intern Med ; 37(2): 415-438, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34508290

RESUMEN

BACKGROUND: Previous meta-analyses of the benefits and harms of glucagon-like peptide-1 receptor agonists (GLP1RAs) have been limited to specific outcomes and comparisons and often included short-term results. We aimed to estimate the longer-term effects of GLP1RAs on cardiovascular risk factors, microvascular and macrovascular complications, mortality, and adverse events in patients with type 2 diabetes, compared to placebo and other anti-hyperglycemic medications. METHODS: We searched PubMed, Scopus, and clinicaltrials.gov (inception-July 2019) for randomized controlled trials ≥ 52 weeks' duration that compared a GLP1RA to placebo or other anti-hyperglycemic medication and included at least one outcome of interest. Outcomes included cardiovascular risk factors, microvascular and macrovascular complications, all-cause mortality, and treatment-related adverse events. We performed random effects meta-analyses to give summary estimates using weighted mean differences (MD) and pooled relative risks (RR). Risk of bias was assessed using the Cochrane Collaboration risk of bias in randomized trials tool. Quality of evidence was summarized using the Grading of Recommendations, Assessment, Development, and Evaluation approach. The study was registered a priori with PROSPERO (CRD42018090506). RESULTS: Forty-five trials with a mean duration of 1.7 years comprising 71,517 patients were included. Compared to placebo, GLP1RAs reduced cardiovascular risk factors, microvascular complications (including renal events, RR 0.85, 0.80-0.90), macrovascular complications (including stroke, RR 0.86, 0.78-0.95), and mortality (RR 0.89, 0.84-0.94). Compared to other anti-hyperglycemic medications, GLP1RAs only reduced cardiovascular risk factors. Increased gastrointestinal events causing treatment discontinuation were observed in both comparisons. DISCUSSION: GLP1RAs reduced cardiovascular risk factors and increased gastrointestinal events compared to placebo and other anti-hyperglycemic medications. GLP1RAs also reduced MACE, stroke, renal events, and mortality in comparisons with placebo; however, analyses were inconclusive for comparisons with other anti-hyperglycemic medications. Given the high costs of GLP1RAs, the lack of long-term evidence comparing GLP1RAs to other anti-hyperglycemic medications has significant policy and clinical practice implications.


Asunto(s)
Diabetes Mellitus Tipo 2 , Receptor del Péptido 1 Similar al Glucagón , Diabetes Mellitus Tipo 2/inducido químicamente , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/uso terapéutico , Humanos , Hipoglucemiantes/efectos adversos
4.
Am J Transplant ; 21(4): 1365-1375, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33251712

RESUMEN

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.


Asunto(s)
Productos Biológicos , Diabetes Mellitus Tipo 1 , Trasplante de Islotes Pancreáticos , Costos y Análisis de Costo , Diabetes Mellitus Tipo 1/cirugía , Humanos , Trasplante Heterólogo , Estados Unidos
5.
Diabetes Obes Metab ; 22(11): 2045-2054, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32573927

RESUMEN

AIMS: To test whether a long-acting GLP-1 receptor agonist would improve glucose control in patients with type 1 diabetes (T1D) and to determine whether the presence of residual beta cell function would affect the response. In addition, we sought to determine whether the drug would affect beta cell function. METHODS: We performed a randomized placebo-controlled trial of exenatide extended release (ER) in participants with T1D with and without detectable levels of C-peptide. Seventy-nine participants were randomized to exenatide ER 2 mcg weekly, or placebo, stratified by the presence or absence of detectable C-peptide levels. The primary outcome was the difference in glycated haemoglobin (HbA1c) levels at 24 weeks. Participants were followed for another 6 months off study drug. RESULTS: At week 24, the time of the primary outcome, the least squares (LS) mean HbA1c level was 7.76% (95% confidence interval [CI] 7.42, 8.10) in the exenatide ER group versus 8.0% (95% CI 7.64, 8.35) in the placebo group (P = 0.08). At week 12 the LS mean HbA1c levels were 7.71% (95% CI 7.37, 8.05) in the exenatide ER group versus 8.05% (95% CI 7.7, 8.4) in the placebo group (P = 0.01). The improvement at week 12 was driven mainly by those with detectable levels of C-peptide. Those treated with exenatide ER lost weight at 12 and 24 weeks compared to those treated with placebo (P <0.001 and P = 0.007). The total insulin dose was lower, but not when corrected for body weight, and was not affected by residual insulin production. Adverse events were more frequent with exenatide ER, but hypoglycaemia was not increased. CONCLUSION: Treatment with exenatide ER may have short-term benefits in some individuals with T1D who are overweight or who have detectable levels of C-peptide, but short-term improvements were not sustained.


Asunto(s)
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Exenatida , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/uso terapéutico , Insulina , Ponzoñas/uso terapéutico
6.
Curr Diab Rep ; 18(8): 58, 2018 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-29931562

RESUMEN

PURPOSE OF REVIEW: We provide a review of monogenic diabetes in young children and adolescents with a focus on recognition, management, and pharmacological treatment. RECENT FINDINGS: Monogenic forms of diabetes account for approximately 1-2% of diabetes in children and adolescents, and its incidence has increased in recent years due to greater awareness and wider availability of genetic testing. Monogenic diabetes is due to single gene defects that primarily affect beta cell function with more than 30 different genes reported. Children with antibody-negative, C-peptide-positive diabetes should be evaluated and genetically tested for monogenic diabetes. Accurate genetic diagnosis impacts treatment in the most common types of monogenic diabetes, including the use of sulfonylureas in place of insulin or other glucose-lowering agents or discontinuing pharmacologic treatment altogether. Diagnosis of monogenic diabetes can significantly improve patient care by enabling prediction of the disease course and guiding appropriate management and treatment.


Asunto(s)
Diabetes Mellitus/genética , Diabetes Mellitus/terapia , Adolescente , Niño , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Pruebas Genéticas , Humanos , Mutación/genética , Prevalencia
7.
Pediatr Diabetes ; 19(3): 388-392, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29193502

RESUMEN

Diabetes occurs in 1/90 000 to 1/160 000 births and when diagnosed under 6 months of age is very likely to have a primary genetic cause. FOXP3 encodes a transcription factor critical for T regulatory cell function and mutations are known to cause "immune dysregulation, polyendocrinopathy (including insulin-requiring diabetes), enteropathy, X-linked" (IPEX) syndrome. This condition is often fatal unless patients receive a bone-marrow transplant. Here we describe the phenotype of male neonates and infants who had insulin-requiring diabetes without other features of IPEX syndrome and were found to have mutations in FOXP3. Whole-exome or next generation sequencing of genes of interest was carried out in subjects with isolated neonatal diabetes without a known genetic cause. RT-PCR was carried out to investigate the effects on RNA splicing of a novel intronic splice-site variant. Four male subjects were found to have FOXP3 variants in the hemizygous state: p.Arg114Trp, p.Arg347His, p.Lys393Met, and c.1044+5G>A which was detected in 2 unrelated probands and in a brother diagnosed with diabetes at 2.1 years of age. Of these, p.Arg114Trp is likely a benign rare variant found in individuals of Ashkenazi Jewish ancestry and p.Arg347His has been previously described in patients with classic IPEX syndrome. The p.Lys393Met and c.1044+5G>A variants are novel to this study. RT-PCR studies of the c.1044+5G>A splice variant confirmed it affected RNA splicing by generating both a wild type and truncated transcript. We conclude that FOXP3 mutations can cause early-onset insulin-requiring diabetes with or without other features of IPEX syndrome.


Asunto(s)
Diabetes Mellitus Tipo 1/congénito , Diabetes Mellitus/genética , Diarrea/diagnóstico , Factores de Transcripción Forkhead/genética , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Enfermedades del Sistema Inmune/congénito , Sistema de Registros , Diabetes Mellitus Tipo 1/diagnóstico , Humanos , Enfermedades del Sistema Inmune/diagnóstico , Lactante , Recién Nacido , Masculino
8.
Comput Chem Eng ; 112: 57-69, 2018 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-30287976

RESUMEN

Artificial pancreas (AP) systems provide automated regulation of blood glucose concentration (BGC) for people with type 1 diabetes (T1D). An AP includes three components: a continuous glucose monitoring (CGM) sensor, a controller calculating insulin infusion rate based on the CGM signal, and a pump delivering the insulin amount calculated by the controller to the patient. The performance of the AP system depends on successful operation of these three components. Many APs use model predictive controllers that rely on models to predict BGC and to calculate the optimal insulin infusion rate. The performance of model-based controllers depends on the accuracy of the models that is affected by large dynamic changes in glucose-insulin metabolism or equipment performance that may move the operating conditions away from those used in developing the models and designing the control system. Sensor errors and missing signals will cause calculation of erroneous insulin infusion rates. And the performance of the controller may vary at each sampling step and each period (meal, exercise, and sleep), and from day to day. Here we describe a multi-level supervision and controller modification (ML-SCM) module is developed to supervise the performance of the AP system and retune the controller. It supervises AP performance in 3 time windows: sample level, period level, and day level. At sample level, an online controller performance assessment sub-module will generate controller performance indexes to evaluate various components of the AP system and conservatively modify the controller. A sensor error detection and signal reconciliation module will detect sensor error and reconcile the CGM sensor signal at each sample. At period level, the controller performance is evaluated with information collected during a certain time period and the controller is tuned more aggressively. At the day level, the daily CGM ranges are further analyzed to determine the adjustable range of controller parameters used for sample level and period level. Thirty subjects in the UVa/Padova metabolic simulator were used to evaluate the performance of the ML-SCM module and one clinical experiment is used to illustrate its performance in a clinical environment. The results indicate that the AP system with an ML-SCM module has a safer range of glucose concentration distribution and more appropriate insulin infusion rate suggestions than an AP system without the ML-SCM module.

9.
Proc Natl Acad Sci U S A ; 111(22): E2319-28, 2014 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-24843127

RESUMEN

Insulin resistance, hyperinsulinemia, and hyperproinsulinemia occur early in the pathogenesis of type 2 diabetes (T2D). Elevated levels of proinsulin and proinsulin intermediates are markers of ß-cell dysfunction and are strongly associated with development of T2D in humans. However, the mechanism(s) underlying ß-cell dysfunction leading to hyperproinsulinemia is poorly understood. Here, we show that disruption of insulin receptor (IR) expression in ß cells has a direct impact on the expression of the convertase enzyme carboxypeptidase E (CPE) by inhibition of the eukaryotic translation initiation factor 4 gamma 1 translation initiation complex scaffolding protein that is mediated by the key transcription factors pancreatic and duodenal homeobox 1 and sterol regulatory element-binding protein 1, together leading to poor proinsulin processing. Reexpression of IR or restoring CPE expression each independently reverses the phenotype. Our results reveal the identity of key players that establish a previously unknown link between insulin signaling, translation initiation, and proinsulin processing, and provide previously unidentified mechanistic insight into the development of hyperproinsulinemia in insulin-resistant states.


Asunto(s)
Carboxipeptidasa H/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Factor 4G Eucariótico de Iniciación/metabolismo , Células Secretoras de Insulina/fisiología , Insulina/metabolismo , Animales , Carboxipeptidasa H/genética , Células Cultivadas , Diabetes Mellitus Tipo 2/genética , Estrés del Retículo Endoplásmico/fisiología , Factor 4G Eucariótico de Iniciación/genética , Estudio de Asociación del Genoma Completo , Proteínas de Homeodominio/metabolismo , Humanos , Células Secretoras de Insulina/citología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Biosíntesis de Proteínas/fisiología , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Transducción de Señal/fisiología , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Transactivadores/metabolismo
10.
Nature ; 466(7306): 627-31, 2010 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-20562852

RESUMEN

The molecular clock maintains energy constancy by producing circadian oscillations of rate-limiting enzymes involved in tissue metabolism across the day and night. During periods of feeding, pancreatic islets secrete insulin to maintain glucose homeostasis, and although rhythmic control of insulin release is recognized to be dysregulated in humans with diabetes, it is not known how the circadian clock may affect this process. Here we show that pancreatic islets possess self-sustained circadian gene and protein oscillations of the transcription factors CLOCK and BMAL1. The phase of oscillation of islet genes involved in growth, glucose metabolism and insulin signalling is delayed in circadian mutant mice, and both Clock and Bmal1 (also called Arntl) mutants show impaired glucose tolerance, reduced insulin secretion and defects in size and proliferation of pancreatic islets that worsen with age. Clock disruption leads to transcriptome-wide alterations in the expression of islet genes involved in growth, survival and synaptic vesicle assembly. Notably, conditional ablation of the pancreatic clock causes diabetes mellitus due to defective beta-cell function at the very latest stage of stimulus-secretion coupling. These results demonstrate a role for the beta-cell clock in coordinating insulin secretion with the sleep-wake cycle, and reveal that ablation of the pancreatic clock can trigger the onset of diabetes mellitus.


Asunto(s)
Factores de Transcripción ARNTL/genética , Proteínas CLOCK/genética , Ritmo Circadiano/fisiología , Diabetes Mellitus/metabolismo , Insulina/sangre , Islotes Pancreáticos/metabolismo , Factores de Transcripción ARNTL/deficiencia , Factores de Transcripción ARNTL/metabolismo , Envejecimiento/genética , Envejecimiento/patología , Animales , Glucemia/análisis , Glucemia/metabolismo , Proteínas CLOCK/deficiencia , Proteínas CLOCK/metabolismo , Proliferación Celular , Tamaño de la Célula , Supervivencia Celular , Ritmo Circadiano/genética , Diabetes Mellitus/genética , Perfilación de la Expresión Génica , Intolerancia a la Glucosa/genética , Prueba de Tolerancia a la Glucosa , Técnicas In Vitro , Insulina/metabolismo , Secreción de Insulina , Islotes Pancreáticos/patología , Ratones , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Fenotipo , Sueño/genética , Sueño/fisiología , Vesículas Sinápticas/metabolismo , Vigilia/genética , Vigilia/fisiología
11.
J Med Genet ; 52(9): 612-6, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26101329

RESUMEN

BACKGROUND: Diabetes in neonates usually has a monogenic aetiology; however, the cause remains unknown in 20-30%. Heterozygous INS mutations represent one of the most common gene causes of neonatal diabetes mellitus. METHODS: Clinical and functional characterisation of a novel homozygous intronic mutation (c.187+241G>A) in the insulin gene in a child identified through the Monogenic Diabetes Registry (http://monogenicdiabetes.uchicago.edu). RESULTS: The proband had insulin-requiring diabetes from birth. Ultrasonography revealed a structurally normal pancreas and C-peptide was undetectable despite readily detectable amylin, suggesting the presence of dysfunctional ß cells. Whole-exome sequencing revealed the novel mutation. In silico analysis predicted a mutant mRNA product resulting from preferential recognition of a newly created splice site. Wild-type and mutant human insulin gene constructs were derived and transiently expressed in INS-1 cells. We confirmed the predicted transcript and found an additional transcript created via an ectopic splice acceptor site. CONCLUSIONS: Dominant INS mutations cause diabetes via a mutated translational product causing endoplasmic reticulum stress. We describe a novel mechanism of diabetes, without ß cell death, due to creation of two unstable mutant transcripts predicted to undergo nonsense and non-stop-mediated decay, respectively. Our discovery may have broader implications for those with insulin deficiency later in life.


Asunto(s)
Diabetes Mellitus/genética , Insulina Regular Humana/genética , Intrones , Mutación , Diabetes Mellitus/etiología , Humanos , Lactante , Análisis de Secuencia de ADN
12.
Proc Natl Acad Sci U S A ; 110(13): 4911-6, 2013 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-23479621

RESUMEN

We quantitatively analyzed particle tracking data on insulin granules expressing fluorescent fusion proteins in MIN6 cells to better understand the motions contributing to intracellular transport and, more generally, the means for characterizing systems far from equilibrium. Care was taken to ensure that the statistics reflected intrinsic features of the individual granules rather than details of the measurement and overall cell state. We find anomalous diffusion. Interpreting such data conventionally requires assuming that a process is either ergodic with particles working against fluctuating obstacles (fractional brownian motion) or nonergodic with a broad distribution of dwell times for traps (continuous-time random walk). However, we find that statistical tests based on these two models give conflicting results. We resolve this issue by introducing a subordinated scheme in which particles in cages with random dwell times undergo correlated motions owing to interactions with a fluctuating environment. We relate this picture to the underlying microtubule structure by imaging in the presence of vinblastine. Our results provide a simple physical picture for how diverse pools of insulin granules and, in turn, biphasic secretion could arise.


Asunto(s)
Insulina/metabolismo , Microtúbulos/metabolismo , Modelos Biológicos , Vesículas Secretoras/metabolismo , Animales , Transporte Biológico Activo/efectos de los fármacos , Transporte Biológico Activo/fisiología , Línea Celular , Ratones , Moduladores de Tubulina/farmacología , Vinblastina/farmacología
13.
Proc Natl Acad Sci U S A ; 110(49): 19689-94, 2013 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-24248363

RESUMEN

Analyses of random walks traditionally use the mean square displacement (MSD) as an order parameter characterizing dynamics. We show that the distribution of relative angles of motion between successive time intervals of random walks in two or more dimensions provides information about stochastic processes beyond the MSD. We illustrate the behavior of this measure for common models and apply it to experimental particle tracking data. For a colloidal system, the distribution of relative angles reports sensitively on caging as the density varies. For transport mediated by molecular motors on filament networks in vitro and in vivo, we discover self-similar properties that cannot be described by existing models and discuss possible scenarios that can lead to the elucidated statistical features.


Asunto(s)
Interpretación Estadística de Datos , Modelos Teóricos , Movimiento (Física) , Procesos Estocásticos , Citoesqueleto de Actina/química , Coloides/química
14.
Diabetologia ; 58(7): 1430-5, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25877689

RESUMEN

AIMS/HYPOTHESIS: Individuals with heterozygous activating mutations of the KCNJ11 gene encoding a subunit of the ATP-sensitive potassium channel (KATP) can usually be treated with oral sulfonylurea (SU) pills in lieu of insulin injections. The aim of this study was to test our hypothesis that younger age at the time of initiation of SU therapy is correlated with lower required doses of SU therapy, shorter transition time and decreased likelihood of requiring additional diabetes medications. METHODS: We performed a retrospective cohort study using data on 58 individuals with neonatal diabetes due to KCNJ11 mutations identified through the University of Chicago Monogenic Diabetes Registry ( http://monogenicdiabetes.uchicago.edu/registry ). We assessed the influence of age at initiation of SU therapy on treatment outcomes. RESULTS: HbA1c fell from an average of 8.5% (69 mmol/mol) before transition to 6.2% (44 mmol/mol) after SU therapy (p < 0.001). Age of initiation of SU correlated with the dose (mg kg(-1) day(-1)) of SU required at follow-up (r = 0.80, p < 0.001). Similar associations were observed across mutation subtypes. Ten participants required additional glucose-lowering medications and all had initiated SU at age 13 years or older. No serious adverse events were reported. CONCLUSIONS/INTERPRETATION: Earlier age at initiation of SU treatment is associated with improved response to SU therapy. Declining sensitivity to SU may be due to loss of beta cell mass over time in those treated with insulin. Our data support the need for early genetic diagnosis and appropriate personalised treatment in all cases of neonatal diabetes.


Asunto(s)
Diabetes Mellitus/congénito , Diabetes Mellitus/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Canales de Potasio de Rectificación Interna/genética , Compuestos de Sulfonilurea/uso terapéutico , Adolescente , Adulto , Factores de Edad , Edad de Inicio , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Femenino , Gliburida/uso terapéutico , Hemoglobina Glucada/análisis , Humanos , Lactante , Recién Nacido , Masculino , Mutación/genética , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
15.
Pediatr Diabetes ; 15(3): 252-6, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24138066

RESUMEN

Neonatal diabetes mellitus is known to have over 20 different monogenic causes. A syndrome of permanent neonatal diabetes along with primary microcephaly with simplified gyral pattern associated with severe infantile epileptic encephalopathy was recently described in two independent reports in which disease-causing homozygous mutations were identified in the immediate early response-3 interacting protein-1 (IER3IP1) gene. We report here an affected male born to a non-consanguineous couple who was noted to have insulin-requiring permanent neonatal diabetes, microcephaly, and generalized seizures. He was also found to have cortical blindness, severe developmental delay and numerous dysmorphic features. He experienced a slow improvement but not abrogation of seizure frequency and severity on numerous anti-epileptic agents. His clinical course was further complicated by recurrent respiratory tract infections and he died at 8 years of age. Whole exome sequencing was performed on DNA from the proband and parents. He was found to be a compound heterozygote with two different mutations in IER3IP1: p.Val21Gly (V21G) and a novel frameshift mutation p.Phe27fsSer*25. IER3IP1 is a highly conserved protein with marked expression in the cerebral cortex and in beta cells. This is the first reported case of compound heterozygous mutations within IER3IP1 resulting in neonatal diabetes. The triad of microcephaly, generalized seizures, and permanent neonatal diabetes should prompt screening for mutations in IER3IP1. As mutations in genes such as NEUROD1 and PTF1A could cause a similar phenotype, next-generation sequencing approaches-such as exome sequencing reported here-may be an efficient means of uncovering a diagnosis in future cases.


Asunto(s)
Proteínas Portadoras/genética , Diabetes Mellitus/genética , Epilepsia Generalizada/etiología , Mutación del Sistema de Lectura , Enfermedades del Recién Nacido/genética , Proteínas de la Membrana/genética , Microcefalia/etiología , Mutación Puntual , Sustitución de Aminoácidos , Ceguera Cortical/etiología , Discapacidades del Desarrollo/etiología , Diabetes Mellitus/fisiopatología , Diabetes Mellitus/terapia , Epilepsia Generalizada/fisiopatología , Epilepsia Generalizada/terapia , Resultado Fatal , Heterocigoto , Humanos , Recién Nacido , Enfermedades del Recién Nacido/fisiopatología , Masculino , Microcefalia/fisiopatología , Microcefalia/terapia , Manifestaciones Neurológicas , Índice de Severidad de la Enfermedad
16.
JCEM Case Rep ; 2(2): luae003, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38304011

RESUMEN

The 1p36 deletion syndrome involves a phenotypic presentation that includes central nervous system, cardiac, and craniofacial anomalies. We report the case of a 21-year-old female patient with 1p36 deletion syndrome who was found to have noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) after hospitalization for persistent falls. On admission, vital signs were normal and physical examination revealed a thin, nonverbal patient. During hospitalization and prolonged fasting (14-18 hours), she persistently developed hypoglycemia (serum glucose nadir 57 mg/dL [3.2 mmol/L] [70-100 mg/dL; 3.9-5.6 mmol/L]). Subjective symptoms of hypoglycemia were not confirmed due to patient's cognitive impairment. Hypoglycemic events continued despite feeding and dextrose-containing fluids. Further workup included a critical sample that revealed a serum glucose 59 mg/dL (3.3 mmol/L), insulin 20.6 µIU/mL (123.6 pmol/L [5-15 µIU/mL; 30.0-90 pmol/L]), proinsulin 33 pmol/L (3.6-22 pmol/L), C-peptide 1.74 ng/mL (0.58 nmol/L [0.8-3.85 ng/mL; 0.27-1.28 nmol/L]) and beta-hydroxybutyrate < 1.04 mg/dL (< 0.10 mmol/L; [< 4.2 mg/dL; < 0.4 mmol/L]). Insulin antibodies were negative. After confirmed insulin-mediated hypoglycemia, imaging studies followed. Pancreatic protocol abdominal computed tomography (CT), Ga-68 DOTATATE PET/CT scan, and endoscopic ultrasound found no pancreatic mass. Selective arterial calcium stimulation test showed a two-fold increase in insulin levels in 3/3 catheterized pancreatic territories. The patient started octreotide injections with resolution of hypoglycemia and was discharged on monthly lanreotide injections. To our knowledge, this is the first case reported of noninsulinoma pancreatogenous hypoglycemia in a patient with 1p36 deletion syndrome.

17.
Diabetes Care ; 47(3): 393-400, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38151474

RESUMEN

OBJECTIVE: This multicenter prospective cohort study compared pancreas volume as assessed by MRI, metabolic scores derived from oral glucose tolerance testing (OGTT), and a combination of pancreas volume and metabolic scores for predicting progression to stage 3 type 1 diabetes (T1D) in individuals with multiple diabetes-related autoantibodies. RESEARCH DESIGN AND METHODS: Pancreas MRI was performed in 65 multiple autoantibody-positive participants enrolled in the Type 1 Diabetes TrialNet Pathway to Prevention study. Prediction of progression to stage 3 T1D was assessed using pancreas volume index (PVI), OGTT-derived Index60 score and Diabetes Prevention Trial-Type 1 Risk Score (DPTRS), and a combination of PVI and DPTRS. RESULTS: PVI, Index60, and DPTRS were all significantly different at study entry in 11 individuals who subsequently experienced progression to stage 3 T1D compared with 54 participants who did not experience progression (P < 0.005). PVI did not correlate with metabolic testing across individual study participants. PVI declined longitudinally in the 11 individuals diagnosed with stage 3 T1D, whereas Index60 and DPTRS increased. The area under the receiver operating characteristic curve for predicting progression to stage 3 from measurements at study entry was 0.76 for PVI, 0.79 for Index60, 0.79 for DPTRS, and 0.91 for PVI plus DPTRS. CONCLUSIONS: These findings suggest that measures of pancreas volume and metabolism reflect distinct components of risk for developing stage 3 type 1 diabetes and that a combination of these measures may provide superior prediction than either alone.


Asunto(s)
Diabetes Mellitus Tipo 1 , Humanos , Diabetes Mellitus Tipo 1/diagnóstico , Estudios Prospectivos , Páncreas/diagnóstico por imagen , Páncreas/metabolismo , Factores de Riesgo , Autoanticuerpos , Imagen por Resonancia Magnética
18.
Cell Metab ; 7(4): 280-1, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18396130

RESUMEN

BAD, a proapoptotic member of the Bcl-2 family of proteins, is regulated by phosphorylation. A recent study (Danial et al., 2008) suggests a phosphorylation-state-dependent bifunctional role of BAD in the regulation of glucose-stimulated insulin secretion and beta cell mass.


Asunto(s)
Células Secretoras de Insulina/metabolismo , Proteína Letal Asociada a bcl/química , Proteína Letal Asociada a bcl/metabolismo , Apoptosis , Diabetes Mellitus Tipo 2/patología , Diabetes Mellitus Tipo 2/fisiopatología , Glucosa/metabolismo , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/citología , Fosforilación
20.
Diabetes Care ; 46(3): 608-612, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36637968

RESUMEN

OBJECTIVE: To examine sleep patterns in adults with maturity-onset diabetes of the young (MODY). RESEARCH DESIGN AND METHODS: Adults with glucokinase (GCK)-MODY and transcription factor (TF)-related MODY (HNF1A, HNF1B, HNF4A) were recruited (n = 24; age 46.0 years, 79% women, BMI 24.7 kg/m2) from The University of Chicago's Monogenic Diabetes Registry. Sleep patterns were assessed by 2-week wrist actigraphy (total 315 nights), one night of a home sleep apnea test, and validated surveys. RESULTS: Overall, compared with established criteria, 29% of participants had sleep latency ≥15 min, 38% had sleep efficiency ≤85%, 46% had wake after sleep onset >40 min, all indicating poor objective sleep quality. Among all participants, 54% had a sleep duration below the recommended minimum of 7 h, 88% reported poor sleep quality, 58% had obstructive sleep apnea, and 71% reported insomnia. Compared with GCK-MODY, participants with TF-related MODY had poorer objective sleep quality and increased night-to-night variability in sleep patterns. CONCLUSIONS: Sleep disturbances appear to be common in adults with MODY despite absent traditional risk factors for sleep disorders. Future research investigating the sleep-diabetes relationship is warranted in this population.


Asunto(s)
Diabetes Mellitus Tipo 2 , Trastornos Intrínsecos del Sueño , Sueño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Glucoquinasa/genética , Factor Nuclear 1-alfa del Hepatocito/genética , Mutación , Factores de Riesgo , Trastornos Intrínsecos del Sueño/etiología
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