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Type 1 diabetes (T1D) results from progressive loss of pancreatic islet mass through autoimmunity targeted at a diverse, yet limited, series of molecules that are expressed in the pancreatic β cell. Identification of these molecular targets provides insight into the pathogenic process, diagnostic assays, and potential therapeutic agents. Autoantigen candidates were identified from microarray expression profiling of human and rodent pancreas and islet cells and screened with radioimmunoprecipitation assays using new-onset T1D and prediabetic sera. A high-ranking candidate, the zinc transporter ZnT8 (Slc30A8), was targeted by autoantibodies in 60-80% of new-onset T1D compared with <2% of controls and <3% type 2 diabetic and in up to 30% of patients with other autoimmune disorders with a T1D association. ZnT8 antibodies (ZnTA) were found in 26% of T1D subjects classified as autoantibody-negative on the basis of existing markers [glutamate decarboxylase (GADA), protein tyrosine phosphatase IA2 (IA2A), antibodies to insulin (IAA), and islet cytoplasmic autoantibodies (ICA)]. Individuals followed from birth to T1D showed ZnT8A as early as 2 years of age and increasing levels and prevalence persisting to disease onset. ZnT8A generally emerged later than GADA and IAA in prediabetes, although not in a strict order. The combined measurement of ZnT8A, GADA, IA2A, and IAA raised autoimmunity detection rates to 98% at disease onset, a level that approaches that needed to detect prediabetes in a general pediatric population. The combination of bioinformatics and molecular engineering used here will potentially generate other diabetes autoimmunity markers and is also broadly applicable to other autoimmune disorders.

Normal ageing is associated with characteristic changes in brain microstructure. Although in vivo neuroimaging captures spatial and temporal patterns of age-related changes of anatomy at the macroscopic scale, our knowledge of the underlying (patho)physiological processes at cellular and molecular levels is still limited. The aim of this study is to explore brain tissue properties in normal ageing using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach in a cohort of 26 adults, aged 18–85years, we performed voxel-based morphometric (VBM) analysis and voxel-based quantification (VBQ) of diffusion tensor, magnetization transfer (MT), R1, and R2* relaxation parameters. We found age-related reductions in cortical and subcortical grey matter volume paralleled by changes in fractional anisotropy (FA), mean diffusivity (MD), MT and R2*. The latter were regionally specific depending on their differential sensitivity to microscopic tissue properties. VBQ of white matter revealed distinct anatomical patterns of age-related change in microstructure. Widespread and profound reduction in MT contrasted with local FA decreases paralleled by MD increases. R1 reductions and R2* increases were observed to a smaller extent in overlapping occipito-parietal white matter regions. We interpret our findings, based on current biophysical models, as a fingerprint of age-dependent brain atrophy and underlying microstructural changes in myelin, iron deposits and water. The VBQ approach we present allows for systematic unbiased exploration of the interaction between imaging parameters and extends current methods for detection of neurodegenerative processes in the brain. The demonstrated parameter-specific distribution patterns offer insights into age-related brain structure changes in vivo and provide essential baseline data for studying disease against a background of healthy ageing. ►High-resolution FLASH-based parameter mapping is suitable for clinical purposes. ►Patterns of age-dependent parameter changes reflect specificity to tissue properties. ►Combining VBM and VBQ offers complementary information about brain architecture.

Insulin sparks autoimmunity Autoimmune reactions, in which the body's white blood cells harm its own tissues, cause many diseases including diabetes, multiple sclerosis and arthritis. It is not known why immune cells target certain organs, and in particular for childhood diabetes, why only insulin-producing cells are killed. Nakayama et al . now report that this may be because insulin itself is a primary autoantigen for autoimmune diabetes. In NOD mice, the standard animal model for diabetes, when the part of the insulin molecule that gives rise to autoantibodies is altered, autoimmune diabetes disappears. This also suggests that deletional immune therapy could be a practical proposition. The possible clinical relevance of this work is confirmed by a separate study by Kent et al . of human patients with type 1 diabetes. T lymphocytes found in the draining lymph nodes around the pancreas specifically recognize part of the insulin protein. This has implications for antigen specific therapies and islet-cell transplantation in diabetes. A fundamental question about the pathogenesis of spontaneous autoimmune diabetes is whether there are primary autoantigens. For type 1 diabetes it is clear that multiple islet molecules are the target of autoimmunity in man and animal models 1 , 2 . It is not clear whether any of the target molecules are essential for the destruction of islet beta cells. Here we show that the proinsulin/insulin molecules have a sequence that is a primary target of the autoimmunity that causes diabetes of the non-obese diabetic (NOD) mouse. We created insulin 1 and insulin 2 gene knockouts combined with a mutated proinsulin transgene (in which residue 16 on the B chain was changed to alanine) in NOD mice. This mutation abrogated the T-cell stimulation of a series of the major insulin autoreactive NOD T-cell clones 3 . Female mice with only the altered insulin did not develop insulin autoantibodies, insulitis or autoimmune diabetes, in contrast with mice containing at least one copy of the native insulin gene. We suggest that proinsulin is a primary autoantigen of the NOD mouse, and speculate that organ-restricted autoimmune disorders with marked major histocompatibility complex (MHC) restriction of disease are likely to have specific primary autoantigens.

A common problem in gradient-echo echo planar imaging (EPI) is the occurrence of image distortions and signal losses caused by susceptibility gradients near air/tissue interfaces. Since EPI is frequently used for functional magnetic resonance imaging experiments based on the blood oxygenation level-dependent effect, functional studies of certain brain regions affected by susceptibility gradients, such as the temporal lobes and the orbitofrontal cortex, may be compromised. In this work a method for signal recovery in certain regions of the orbitofrontal cortex is presented. The influence of in-plane susceptibility gradients is reduced by optimization of the imaging slice orientation. Through-plane susceptibility gradients are partly compensated by means of a moderate preparation gradient pulse similar to z-shimming. In contrast to several other techniques proposed in the literature for reducing susceptibility effects, this method does not compromise the temporal resolution and is therefore applicable to event-related studies.

Despite the availability of national and international guidelines, evidence suggests that chronic obstructive pulmonary disease (COPD) treatment is not always prescribed according to recommendations. This study evaluated the current management of patients with COPD using a large UK primary-care database. This analysis used electronic patient records and patient-completed questionnaires from the Optimum Patient Care Research Database. Data on current management were analyzed by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) group and presence or absence of a concomitant asthma diagnosis, in patients with a COPD diagnosis at ≥35 years of age and with spirometry results supportive of the COPD diagnosis. A total of 24,957 patients were analyzed, of whom 13,557 (54.3%) had moderate airflow limitation (GOLD Stage 2 COPD). The proportion of patients not receiving pharmacologic treatment for COPD was 17.0% in the total COPD population and 17.7% in the GOLD Stage 2 subset. Approximately 50% of patients in both cohorts were receiving inhaled corticosteroids (ICS), either in combination with a long-acting β2-agonist (LABA; 26.7% for both cohorts) or a LABA and a long-acting muscarinic antagonist (LAMA; 23.2% and 19.9%, respectively). ICS + LABA and ICS + LABA + LAMA were the most frequently used treatments in GOLD Groups A and B. Of patients without concomitant asthma, 53.7% of the total COPD population and 50.2% of the GOLD Stage 2 subset were receiving ICS. Of patients with GOLD Stage 2 COPD and no exacerbations in the previous year, 49% were prescribed ICS. A high proportion of GOLD Stage 2 COPD patients were symptomatic on their current management (36.6% with modified Medical Research Council score ≥2; 76.4% with COPD Assessment Test score ≥10). COPD is not treated according to GOLD and National Institute for Health and Care Excellence recommendations in the UK primary-care setting. Some patients receive no treatment despite experiencing symptoms. Among those on treatment, most receive ICS irrespective of severity of airflow limitation, asthma diagnosis, and exacerbation history. Many patients on treatment continue to have symptoms.

Cognitive neuroimaging studies typically require fast whole brain image acquisition with maximal sensitivity to small BOLD signal changes. To increase the sensitivity, higher field strengths are often employed, since they provide an increased image signal-to-noise ratio (SNR). However, as image SNR increases, the relative contribution of physiological noise to the total time series noise will be greater compared to that from thermal noise. At 7 T, we studied how the physiological noise contribution can be best reduced for EPI time series acquired at three different spatial resolutions (1.1 mm × 1.1 mm × 1.8 mm, 2 mm × 2 mm × 2 mm and 3 mm × 3 mm × 3 mm). Applying optimal physiological noise correction methods improved temporal SNR (tSNR) and increased the numbers of significantly activated voxels in fMRI visual activation studies for all sets of acquisition parameters. The most dramatic results were achieved for the lowest spatial resolution, an acquisition parameter combination commonly used in cognitive neuroimaging which requires high functional sensitivity and temporal resolution (i.e. 3mm isotropic resolution and whole brain image repetition time of 2s). For this data, physiological noise models based on cardio-respiratory information improved tSNR by approximately 25% in the visual cortex and 35% sub-cortically. When the time series were additionally corrected for the residual effects of head motion after retrospective realignment, the tSNR was increased by around 58% in the visual cortex and 71% sub-cortically, exceeding tSNR ~140. In conclusion, optimal physiological noise correction at 7 T increases tSNR significantly, resulting in the highest tSNR per unit time published so far. This tSNR improvement translates into a significant increase in BOLD sensitivity, facilitating the study of even subtle BOLD responses.

Reproducibility and repeatability of experiments are the fundamental prerequisites that allow researchers to validate results and share hydrological knowledge, experience and expertise in the light of global water management problems. Virtual laboratories offer new opportunities to enable these prerequisites since they allow experimenters to share data, tools and pre-defined experimental procedures (i.e. protocols). Here we present the outcomes of a first collaborative numerical experiment undertaken by five different international research groups in a virtual laboratory to address the key issues of reproducibility and repeatability. Moving from the definition of accurate and detailed experimental protocols, a rainfall–runoff model was independently applied to 15 European catchments by the research groups and model results were collectively examined through a web-based discussion. We found that a detailed modelling protocol was crucial to ensure the comparability and reproducibility of the proposed experiment across groups. Our results suggest that sharing comprehensive and precise protocols and running the experiments within a controlled environment (e.g. virtual laboratory) is as fundamental as sharing data and tools for ensuring experiment repeatability and reproducibility across the broad scientific community and thus advancing hydrology in a more coherent way.

A Common Nonsynonymous Single Nucleotide Polymorphism in the SLC30A8 Gene Determines ZnT8 Autoantibody Specificity in Type 1 Diabetes Janet M. Wenzlau 1 , Yu Liu 2 , Liping Yu 1 , Ong Moua 1 , Kimberly T. Fowler 1 , Sampathkumar Rangasamy 1 , Jay Walters 1 , George S. Eisenbarth 1 , Howard W. Davidson 1 and John C. Hutton 1 1 Barbara Davis Center for Childhood Diabetes, University of Colorado Denver, Aurora, Colorado 2 Department of Endocrinology, Nanjing Medical University, First Affiliated Hospital, Nanjing, China Corresponding author: John C. Hutton, john.hutton{at}uchsc.edu Abstract OBJECTIVE— Zinc transporter eight ( SLC30A8 ) is a major target of autoimmunity in human type 1A diabetes and is implicated in type 2 diabetes in genome-wide association studies. The type 2 diabetes nonsynonymous single nucleotide polymorphism (SNP) affecting aa 325 lies within the region of highest ZnT8 autoantibody (ZnT8A) binding, prompting an investigation of its relationship to type 1 diabetes. RESEARCH DESIGN AND METHODS— ZnT8A radioimmunoprecipitation assays were performed in 421 new-onset type 1 diabetic Caucasians using COOH-terminal constructs incorporating the known human aa 325 variants (Trp, Arg, and Gln). Genotypes were determined by PCR-based SNP analysis. RESULTS— Sera from 224 subjects (53%) were reactive to Arg 325 probes, from 185 (44%) to Trp 325 probes, and from 142 (34%) to Gln 325 probes. Sixty subjects reacted only with Arg 325 constructs, 31 with Trp 325 only, and 1 with Gln 325 only. The restriction to either Arg 325 or Trp 325 corresponded with inheritance of the respective C- or T-alleles. A strong gene dosage effect was also evident because both Arg- and Trp-restricted ZnT8As were less prevalent in heterozygous than homozygous individuals. The SLC30A8 SNP allele frequency (75% C and 25% T) varied little with age of type 1 diabetes onset or the presence of other autoantibodies. CONCLUSIONS— The finding that diabetes autoimmunity can be defined by a single polymorphic residue has not previously been documented. It argues against ZnT8 autoimmunity arising from molecular mimicry and suggests a mechanistic link between the two major forms of diabetes. It has implications for antigen-based therapeutic interventions because the response to ZnT8 administration could be protective or immunogenic depending on an individual's genotype. Footnotes Published ahead of print at http://diabetes.diabetesjournals.org on 30 June 2008. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted June 24, 2008. Received February 2, 2008. DIABETES

The SLC30A8 gene encodes the islet-specific transporter ZnT-8, which is hypothesized to provide zinc for insulin-crystal formation. A polymorphic variant in SLC30A8 is associated with altered susceptibility to type 2 diabetes. Several groups have examined the effect of global Slc30a8 gene deletion but the results have been highly variable, perhaps due to the mixed 129SvEv/C57BL/6J genetic background of the mice studied. We therefore sought to remove the conflicting effect of 129SvEv-specific modifier genes. The impact of Slc30a8 deletion was examined in the context of the pure C57BL/6J genetic background. Male C57BL/6J Slc30a8 knockout (KO) mice had normal fasting insulin levels and no change in glucose-stimulated insulin secretion (GSIS) from isolated islets in marked contrast to the ∼50% and ∼35% decrease, respectively, in both parameters observed in male mixed genetic background Slc30a8 KO mice. This observation suggests that 129SvEv-specific modifier genes modulate the impact of Slc30a8 deletion. In contrast, female C57BL/6J Slc30a8 KO mice had reduced (∼20%) fasting insulin levels, though this was not associated with a change in fasting blood glucose (FBG), or GSIS from isolated islets. This observation indicates that gender also modulates the impact of Slc30a8 deletion, though the physiological explanation as to why impaired insulin secretion is not accompanied by elevated FBG is unclear. Neither male nor female C57BL/6J Slc30a8 KO mice showed impaired glucose tolerance. Our data suggest that, despite a marked reduction in islet zinc content, the absence of ZnT-8 does not have a substantial impact on mouse physiology.

Zinc transporter 8 (ZnT8) is a recently identified major autoantigen in type 1 diabetes, and autoantibodies to ZnT8 (ZnT8A) are new markers for disease prediction and diagnosis. Here we report the results of the first international proficiency evaluation of ZnT8A assays by the Diabetes Antibody Standardization Program (DASP). After a pilot workshop in 2007, an expanded ZnT8A workshop was held in 2009, with 26 participating laboratories from 13 countries submitting results of 63 different assays. ZnT8A levels were measured in coded sera from 50 patients with newly diagnosed type 1 diabetes and 100 blood donor controls. Results were analyzed comparing area under the ROC curve (ROC-AUC), sensitivity adjusted to 95% specificity (AS95), concordance of sample ZnT8A positive or negative designation, and autoantibody levels. ZnT8A radio binding assays (RBAs) based on combined immunoprecipitation of the 2 most frequent ZnT8 COOH-terminal domain polymorphic variants showed a median ROC-AUC of 0.848 [interquartile range (IQR) 0.796-0.878] and a median AS95 of 70% (IQR 60%-72%). These RBAs were more sensitive than assays using as antigen either 1 ZnT8 variant only or chimeric constructs joining NH(2)- and COOH-terminal domains, assays based on immunoprecipitation and bioluminescent detection, or assays based on immunofluorescent staining of cells transfected with full-length antigen. The DASP workshop identified immunoprecipitation-based ZnT8A assays and antigen constructs that achieved both a high degree of sensitivity and specificity and were suitable for more widespread clinical application.