The influence of type 1 diabetes on pancreatic weight.

Aims/hypothesis: Previous studies of pancreases obtained at autopsy or by radiography note reduced pancreas weight (PW) and size, respectively, in type 1 diabetes; this finding is widely considered to be the result of chronic insulinopenia. This literature is, however, limited with respect to the influence of age, sex, anthropometric factors and disease duration on these observations. Moreover, data are sparse for young children, a group of particular interest for type 1 diabetes.

Recruitment of RAG1 and RAG2 to Chromatinized DNA during V(D)J Recombination.

V(D)J recombination is initiated by the binding of the RAG1 and RAG2 proteins to recombination signal sequences (RSSs) that consist of conserved heptamer and nonamer sequences separated by a spacer of either 12 or 23 bp. Here, we used RAG-inducible pro-B v-Abl cell lines in conjunction with chromatin immunoprecipitation to better understand the protein and RSS requirements for RAG recruitment to chromatin. Using a catalytic mutant form of RAG1 to prevent recombination, we did not observe cooperation between RAG1 and RAG2 in their recruitment to endogenous Jκ gene segments over a 48-h time course.

Histone reader BRWD1 targets and restricts recombination to the Igk locus.

B lymphopoiesis requires that immunoglobulin genes be accessible to RAG1-RAG2 recombinase. However, the RAG proteins bind widely to open chromatin, which suggests that additional mechanisms must restrict RAG-mediated DNA cleavage. Here we show that developmental downregulation of interleukin 7 (IL-7)-receptor signaling in small pre-B cells induced expression of the bromodomain-family member BRWD1, which was recruited to a specific epigenetic landscape at Igk dictated by pre-B cell receptor (pre-BCR)-dependent Erk activation.

Rates of diabetic ketoacidosis: international comparison with 49,859 pediatric patients with type 1 diabetes from England, Wales, the U.S., Austria, and Germany.

Objective: Diabetic ketoacidosis (DKA) in children and adolescents with established type 1 diabetes is a major problem with considerable morbidity, mortality, and associated costs to patients, families, and health care systems. We analyzed data from three multinational type 1 diabetes registries/audits with similarly advanced, yet differing, health care systems with an aim to identify factors associated with DKA admissions.

Research Design And Methods: Data from 49,859 individuals <18 years with type 1 diabetes duration ≥1 year from the Prospective Diabetes Follow-up Registry (DPV) initiative (n = 22,397, Austria and Germany), the National Paediatric Diabetes Audit (NPDA; n = 16,314, England and Wales), and the T1D Exchange (T1DX; n = 11,148, U.

RAG Represents a Widespread Threat to the Lymphocyte Genome.

The RAG1 endonuclease, together with its cofactor RAG2, is essential for V(D)J recombination but is a potent threat to genome stability. The sources of RAG1 mis-targeting and the mechanisms that have evolved to suppress it are poorly understood. Here, we report that RAG1 associates with chromatin at thousands of active promoters and enhancers in the genome of developing lymphocytes.

Acute Versus Progressive Onset of Diabetes in NOD Mice: Potential Implications for Therapeutic Interventions in Type 1 Diabetes.

Most natural history models for type 1 diabetes (T1D) propose that overt hyperglycemia results after a progressive loss of insulin-secreting β-cell mass and/or function. To experimentally address this concept, we prospectively determined morning blood glucose measurements every other day in multiple cohorts (total n = 660) of female NOD/ShiLtJ mice starting at 8 weeks of age until diabetes onset or 26 weeks of age. Consistent with this notion, a majority of mice that developed diabetes (354 of 489 [72%]) displayed a progressive increase in blood glucose with transient excursions >200 mg/dL, followed by acute and persistent hyperglycemia at diabetes onset.

Erratum: Disparities in Social Support for Youths With Type 1 Diabetes. Clinical Diabetes 2015;33:62-69.

[This corrects the article on p. 62 in vol. 33, PMID: 25897185.

Genomic landscape of cutaneous T cell lymphoma.

Cutaneous T cell lymphoma (CTCL) is a non-Hodgkin lymphoma of skin-homing T lymphocytes. We performed exome and whole-genome DNA sequencing and RNA sequencing on purified CTCL and matched normal cells. The results implicate mutations in 17 genes in CTCL pathogenesis, including genes involved in T cell activation and apoptosis, NF-κB signaling, chromatin remodeling and DNA damage response.

Combination Therapy Reverses Hyperglycemia in NOD Mice With Established Type 1 Diabetes.

An increasing number of therapies have proven effective at reversing hyperglycemia in the nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D), yet situations of successful translation to human T1D are limited. This may be partly due to evaluating the effect of treating immediately at diagnosis in mice, which may not be reflective of the advanced disease state in humans at disease onset. In this study, we treated NOD mice with new-onset as well as established disease using various combinations of four drugs: antithymocyte globulin (ATG), granulocyte-colony stimulating factor (G-CSF), a dipeptidyl peptidase IV inhibitor (DPP-4i), and a proton pump inhibitor (PPI).

Hemoglobin A1c (HbA1c) changes over time among adolescent and young adult participants in the T1D exchange clinic registry.

Objective: Hemoglobin A1c (HbA1c) levels among individuals with type 1 diabetes (T1D) influence the longitudinal risk for diabetes-related complications. Few studies have examined HbA1c trends across time in children, adolescents, and young adults with T1D. This study examines changes in glycemic control across the specific transition periods of pre-adolescence-to-adolescence and adolescence-to-young adulthood, and the demographic and clinical factors associated with these changes.

1,4-Diketones from Cross-Conjugated Dienones: Potassium Permanganate-Interrupted Nazarov Reaction.

A domino potassium permanganate-interrupted Nazarov reaction to yield syn-2,3-disubstituted 1,4-diketones via a decarbonylative cleavage of the Nazarov oxyallyl intermediate, believed to be without precedent, is presented. This process allows syn substituents to be established stereospecifically on the 2-carbon bridge connecting the ketone carbonyl carbons, and the formation of one carbon-carbon and two carbon-oxygen bonds. Two carbon-carbon bonds are cleaved in this process.

Using photography as a method to explore adolescent challenges and resilience in type 1 diabetes.

Patient-centered approaches to disease management are consistently recognized as valuable tools for improving health outcomes, yet studies are rarely designed to elicit adolescent perspectives. This study sought to better understand the perspectives of youths with type 1 diabetes according to key demographic variables. We conducted an exploratory study through which 40 youths were provided with disposable cameras and prompted to take five photographs each that captured what diabetes meant to them and to provide narratives to accompany their photo choices.

Mechanisms of clonal evolution in childhood acute lymphoblastic leukemia.

Childhood acute lymphoblastic leukemia (ALL) can often be traced to a pre-leukemic clone carrying a prenatal genetic lesion. Postnatally acquired mutations then drive clonal evolution toward overt leukemia. The enzymes RAG1-RAG2 and AID, which diversify immunoglobulin-encoding genes, are strictly segregated in developing cells during B lymphopoiesis and peripheral mature B cells, respectively.

Infection of phytoplankton by aerosolized marine viruses.

Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E.

C-peptide levels in pediatric type 2 diabetes in the Pediatric Diabetes Consortium T2D Clinic Registry.

Objective: To describe C-peptide levels in a large cohort of children with type 2 diabetes T2D and examine associations with demographic and clinical factors.

Methods: The Pediatric Diabetes Consortium (PDC) T2D Registry has collected clinical and biologic data from youth with T2D cared for at eight US Pediatric Diabetes Centers. In this study, we assessed C-peptide levels in 331 youth with T2D (mean age, 16.

Puppy Love, Adolescence, and Chronic Illness: The Importance of Pets for Youth with Type 1 Diabetes.

The benefits of animal-companion ties to well-being are consistently documented, yet few studies use patient-centered methodologies to examine how youth living with chronic illnesses rely on domestic pets for support. Youth with type 1 diabetes (T1D) aged 12 to 19 years (N=40) completed surveys involving a prompt to take five photos of "what diabetes means to you," with an accompanying narrative. Content analysis was conducted for photos/narratives and numeric variables analyzed including socio-economic status (SES: measured by total household income and years of parental education) and HbA1C.

Body mass index changes in youth in the first year after type 1 diabetes diagnosis.

Objectives: To describe changes in weight and body mass index (BMI) during the first year following diagnosis of type 1 diabetes (T1D) and associations with demographic and clinical characteristics.

Study Design: The Pediatric Diabetes Consortium includes 7 US centers with prospective longitudinal data from initial T1D diagnosis. This analysis includes 530 youth with diabetes duration of ≥1 year and measures of BMI at 3 and 12 months after diagnosis.

Disparities in social support systems for youths with type 1 diabetes.

IN BRIEF Low socioeconomic status (SES) is consistently identified as a major risk factor for poor health outcomes in youths with type 1 diabetes, yet little is known about the social factors that yield such disparities. This study used survey research to examine the role of SES by focusing on differential resourcing in social support systems for youths with type 1 diabetes and their parents/caregivers. We identified significant inequalities in social support systems and found that parents from lower-income households engage in few coping activities and rarely identify a primary care provider as the main point of contact when facing a diabetes-related problem.

Single-molecule analysis of RAG-mediated V(D)J DNA cleavage.

The recombination-activating gene products, RAG1 and RAG2, initiate V(D)J recombination during lymphocyte development by cleaving DNA adjacent to conserved recombination signal sequences (RSSs). The reaction involves DNA binding, synapsis, and cleavage at two RSSs located on the same DNA molecule and results in the assembly of antigen receptor genes. We have developed single-molecule assays to examine RSS binding by RAG1/2 and their cofactor high-mobility group-box protein 1 (HMGB1) as they proceed through the steps of this reaction.

Mapping and Quantitation of the Interaction between the Recombination Activating Gene Proteins RAG1 and RAG2.

The RAG endonuclease consists of RAG1, which contains the active site for DNA cleavage, and RAG2, an accessory factor whose interaction with RAG1 is critical for catalytic function. How RAG2 activates RAG1 is not understood. Here, we used biolayer interferometry and pulldown assays to identify regions of RAG1 necessary for interaction with RAG2 and to measure the RAG1-RAG2 binding affinity (KD ∼0.

Predictors of Progression From the Appearance of Islet Autoantibodies to Early Childhood Diabetes: The Environmental Determinants of Diabetes in the Young (TEDDY).

Objective: While it is known that there is progression to diabetes in <10 years in 70% of children with two or more islet autoantibodies, predictors of the progression to diabetes are only partially defined.

Research Design And Methods: The Environmental Determinants of Diabetes in the Young (TEDDY) study has observed 8,503 children who were at increased genetic risk for autoimmune diabetes. Insulin autoantibodies (IAAs), GAD65 autoantibodies (GADAs), and insulinoma-associated protein 2 autoantibodies (IA-2As) were measured every 3 months until 4 years of age and every 6 months thereafter; if results were positive, the autoantibodies were measured every 3 months.

The 6 year incidence of diabetes-associated autoantibodies in genetically at-risk children: the TEDDY study.

Aims/hypothesis: Islet autoantibodies, in addition to elevated blood glucose, define type 1 diabetes. These autoantibodies are detectable for a variable period of time before diabetes onset. Thus, the occurrence of islet autoantibodies is associated with the beginning of the disease process.

Spatio-temporal regulation of RAG2 following genotoxic stress.

V(D)J recombination of lymphocyte antigen receptor genes occurs via the formation of DNA double strand breaks (DSBs) through the activity of RAG1 and RAG2. The co-existence of RAG-independent DNA DSBs generated by genotoxic stressors potentially increases the risk of incorrect repair and chromosomal abnormalities. However, it is not known whether cellular responses to DSBs by genotoxic stressors affect the RAG complex.

The architecture of the 12RSS in V(D)J recombination signal and synaptic complexes.

V(D)J recombination is initiated by RAG1 and RAG2, which together with HMGB1 bind to a recombination signal sequence (12RSS or 23RSS) to form the signal complex (SC) and then capture a complementary partner RSS, yielding the paired complex (PC). Little is known regarding the structural changes that accompany the SC to PC transition or the structural features that allow RAG to distinguish its two asymmetric substrates. To address these issues, we analyzed the structure of the 12RSS in the SC and PC using fluorescence resonance energy transfer (FRET) and molecular dynamics modeling.

Bacteroides dorei dominates gut microbiome prior to autoimmunity in Finnish children at high risk for type 1 diabetes.

The incidence of the autoimmune disease, type 1 diabetes (T1D), has increased dramatically over the last half century in many developed countries and is particularly high in Finland and other Nordic countries. Along with genetic predisposition, environmental factors are thought to play a critical role in this increase. As with other autoimmune diseases, the gut microbiome is thought to play a potential role in controlling progression to T1D in children with high genetic risk, but we know little about how the gut microbiome develops in children with high genetic risk for T1D.