Genome-wide association study of type 2 diabetes in a sample from Mexico City and a meta-analysis of a Mexican-American sample from Starr County, Texas

AIMS/HYPOTHESIS

We report a genome-wide association study of type 2 diabetes in an admixed sample from Mexico City and describe the results of a meta-analysis of this study and another genome-wide scan in a Mexican-American sample from Starr County, TX, USA. The top signals observed in this meta-analysis were followed up in the Diabetes Genetics Replication and Meta-analysis Consortium (DIAGRAM) and DIAGRAM+ datasets.

METHODS

We analysed 967 cases and 343 normoglycaemic controls. The samples were genotyped with the Affymetrix Genome-wide Human SNP array 5.0. Associations of genotyped and imputed markers with type 2 diabetes were tested using a missing data likelihood score test. A fixed-effects meta-analysis including 1,804 cases and 780 normoglycaemic controls was carried out by weighting the effect estimates by their inverse variances.

RESULTS

In the meta-analysis of the two Hispanic studies, markers showing suggestive associations (p < 10(-5)) were identified in two known diabetes genes, HNF1A and KCNQ1, as well as in several additional regions. Meta-analysis of the two Hispanic studies and the recent DIAGRAM+ dataset identified genome-wide significant signals (p < 5 × 10(-8)) within or near the genes HNF1A and CDKN2A/CDKN2B, as well as suggestive associations in three additional regions, IGF2BP2, KCNQ1 and the previously unreported C14orf70.

CONCLUSIONS/INTERPRETATION

We observed numerous regions with suggestive associations with type 2 diabetes. Some of these signals correspond to regions described in previous studies. However, many of these regions could not be replicated in the DIAGRAM datasets. It is critical to carry out additional studies in Hispanic and American Indian populations, which have a high prevalence of type 2 diabetes.

Genome-wide association and meta-analysis in populations from Starr County, Texas, and Mexico City identify type 2 diabetes susceptibility loci and enrichment for expression quantitative trait loci in top signals

AIMS/HYPOTHESIS

We conducted genome-wide association studies (GWASs) and expression quantitative trait loci (eQTL) analyses to identify and characterise risk loci for type 2 diabetes in Mexican-Americans from Starr County, TX, USA.

METHOD

Using 1.8 million directly interrogated and imputed genotypes in 837 unrelated type 2 diabetes cases and 436 normoglycaemic controls, we conducted Armitage trend tests. To improve power in this population with high disease rates, we also performed ordinal regression including an intermediate class with impaired fasting glucose and/or glucose tolerance. These analyses were followed by meta-analysis with a study of 967 type 2 diabetes cases and 343 normoglycaemic controls from Mexico City, Mexico.

RESULT

The top signals (unadjusted p value <1 × 10(-5)) included 49 single nucleotide polymorphisms (SNPs) in eight gene regions (PER3, PARD3B, EPHA4, TOMM7, PTPRD, HNT [also known as RREB1], LOC729993 and IL34) and six intergenic regions. Among these was a missense polymorphism (rs10462020; Gly639Val) in the clock gene PER3, a system recently implicated in diabetes. We also report a second signal (minimum p value 1.52 × 10(-6)) within PTPRD, independent of the previously implicated SNP, in a population of Han Chinese. Top meta-analysis signals included known regions HNF1A and KCNQ1. Annotation of top association signals in both studies revealed a marked excess of trans-acting eQTL in both adipose and muscle tissues.

CONCLUSIONS/INTERPRETATION

In the largest study of type 2 diabetes in Mexican populations to date, we identified modest associations of novel and previously reported SNPs. In addition, in our top signals we report significant excess of SNPs that predict transcript levels in muscle and adipose tissues.

Combating health care fragmentation through integrated health services delivery networks

Introduction

Despite existing initiatives to integrate health services in the Americas Health Care fragmentation remains a significant challenge. Excessive fragmentation leads to difficulties in access to services, delivery of services of poor technical quality, inefficient use of resources, increases in production costs, and low user satisfaction. To address this problem, the Pan American Health Organization (PAHO) has launched the Integrated Health Services Delivery Networks (IHSDN) Initiative to support the development of more accessible, equitable and efficient health care models in the Region [1].

Theory/conceptual framework

IHSDN are defined as a network of organizations that provides, or makes arrangements to provide, equitable, comprehensive, and integrated health services to a defined population and is willing to be held accountable for its clinical and economic outcomes and the health status of the population served. IHSDN require 14 essential attributes for their adequate operation grouped according to four principal domains: model of care, governance and strategy, organization and management, and financial allocation and incentives [1].

Methods

An extensive literature review, expert meetings and country consultations (national, subregional and regional) in the Americas resulted in a set of consensus-based essential attributes and policy options for implementing IHSDN.

Results and conclusions

The research and evidence on health services integration remains limited; however, several studies suggest that IHSDN could improve health systems performance. Principal lessons learned include: i) integration processes are difficult, complex and long term; ii) integration requires extensive systemic changes and a commitment by health workers, health service managers and policymakers; and iii) multiple modalities and degrees of integration can coexist within a single system. The public policy objective is to propose a design that meets each system’s specific organizational needs [1].

Tinea nigra by Hortaea werneckii, a report of 22 cases from Mexico

Tinea nigra is a superficial mycosis caused by Hortaea werneckii. It is an infrequent asymptomatic infection that affects human palms and soles, and is mostly observed in tropical countries. We evaluate retrospectively twenty-two confirmed cases of tinea nigra from a total of eleven yr (1997–2007) and discuss the epidemiology, clinical features and treatment of this disease. In twelve cases, adults were involved, in 10, children. In nineteen cases the disorder was located on palms of hands and in three on soles of feet. In all cases, the obtained isolates were morphologically identified as Hortaea werneckii and the identification of ten isolates was retrospectively confirmed with the help of sequences of the internal transcribed spacer regions of the ribosomal DNA. The patients received topical treatment with Whitfield ointment, ketoconazole, bifonazole, or terbinafine. Treatment with keratolytic agents and topical antifungals was effective.

A gated liquid-scintillator-based neutron detector for fast-ignitor experiments and down-scattered neutron measurements

The detection of neutrons in fast-ignitor experiments or down-scattered neutrons in inertial fusion experiments is very challenging since it requires the neutron detection system to recover within 10-100 ns from a high background orders of magnitude stronger than the signal of interest. The background is either the hard x-ray emission from short-pulse laser target interactions for the fast-ignitor experiments or the primary neutron signal for the down-scattered neutrons. A liquid-scintillator detector has been developed using a gated photomultiplier that suppresses the background signal and eliminates the afterglow present in conventional plastic scintillators.

The National Ignition Facility neutron time-of-flight system and its initial performance (invited)

The National Ignition Facility (NIF) successfully completed its first inertial confinement fusion (ICF) campaign in 2009. A neutron time-of-flight (nTOF) system was part of the nuclear diagnostics used in this campaign. The nTOF technique has been used for decades on ICF facilities to infer the ion temperature of hot deuterium (D(2)) and deuterium-tritium (DT) plasmas based on the temporal Doppler broadening of the primary neutron peak. Once calibrated for absolute neutron sensitivity, the nTOF detectors can be used to measure the yield with high accuracy. The NIF nTOF system is designed to measure neutron yield and ion temperature over 11 orders of magnitude (from 10(8) to 10(19)), neutron bang time in DT implosions between 10(12) and 10(16), and to infer areal density for DT yields above 10(12). During the 2009 campaign, the three most sensitive neutron time-of-flight detectors were installed and used to measure the primary neutron yield and ion temperature from 25 high-convergence implosions using D(2) fuel. The OMEGA yield calibration of these detectors was successfully transferred to the NIF.

Candidate gene association study conditioning on individual ancestry in patients with type 2 diabetes and metabolic syndrome from Mexico City

BACKGROUND

Type 2 diabetes (T2D) is influenced by diverse environmental and genetic risk factors. Metabolic syndrome (MS) increases the risk of cardiovascular disease and diabetes. We analysed 14 cases of polymorphisms located in 10 candidate loci, in a sample of patients with T2D and controls from Mexico City.

METHODS

We analysed the association of 14 polymorphisms located within 10 genes (TCF7L2, ENPP1, ADRB3, KCNJ11, LEPR, PPARgamma, FTO, CDKAL1, SIRT1 and HHEX) with T2D and MS. The analysis included 519 subjects with T2D defined according to the ADA criteria, 389 with MS defined according to the AHA/NHLBI criteria and 547 controls. Association was tested with the program ADMIXMAP including individual ancestry, age, sex, education and in some cases body mass index (BMI), in a logistic regression model.

RESULTS

The two markers located within the TCF7L2 gene showed strong associations with T2D (rs7903146, T allele, odd ratio (OR) = 1.76, p = 0.001 and rs12255372, T allele, OR = 1.78, p = 0.002), but did not show significant association with MS. The non-synonymous rs4994 polymorphism of the ADRB3 gene was associated with T2D (Trp allele, OR = 0.62, p = 0.001) and MS (Trp allele, OR = 0.74, p = 0.018). Nominally significant associations were also observed between T2D and the SIRT1 rs3758391 SNP and MS and the HHEX rs5015480 polymorphism.

CONCLUSIONS

Variants located within the gene TCF7L2 are strongly associated with T2D but not with MS, providing support to previous evidence indicating that polymorphisms at the TCF7L2 gene increase T2D risk. In contrast, the non-synonymous ADRB3 rs4994 polymorphism is associated with T2D and MS.

Results of a multifaceted Intimate Partner Violence training program for pediatric residents

OBJECTIVE

To evaluate the efficacy of a multifaceted Intimate Partner Violence (IPV) intervention on knowledge, attitudes, and screening practices of pediatric residents.

METHODS

The intervention included: an on-site IPV counselor, IPV training for attending physicians, residents and social workers, and screening prompts. Evaluation included baseline and post-training surveys of residents, assessing their knowledge, attitudes, and comfort with IPV screening, patient chart reviews at baseline, 3 months, and 8 months for documentation of IPV screening, and review of the IPV counselor's client charts.

RESULTS

Baseline chart review showed screening rates of less than 1%. Screening rates were 36.2% at 3 months and 33.1% at 8 months. After training, residents were more likely to know: IPV screening questions (47.1% vs. 100%); referral sources (34.3% vs. 82.9%); and the relationship between child abuse and IPV (52.9% vs. 97.1%). At baseline, barriers to IPV screening included time (50%), lack of knowledge of how to screen (26.5%) and where to refer (23.5%). Post-training, barriers were time (44%), presence of children (25.9%) or other adults (18.5%) in the room, and inappropriate location (18.5%). Post-training, none of the residents listed "lack of knowledge" or "lack of referral sources" as barriers to IPV screening. After 12 months, 107 victims of IPV were identified; most referred from inpatient units and subspecialty clinics.

CONCLUSION

A multifaceted IPV intervention increased identification of IPV victims and markedly improved attitudes, comfort, and IPV screening practices of pediatric residents. IPV screening rates were sustainable with minimal ongoing training.

PRACTICE IMPLICATIONS

Consideration should be given to the training and practice supports necessary to encourage IPV screening in the pediatric setting. Educational efforts that familiarize pediatricians with the content surrounding the risk and potential impact of IPV to children and families along with practice supports that make incorporating screening for IPV as easy as possible have the potential to increase the identification of this problem and promote referrals to IPV agencies for follow-up and intervention where needed.

The relationship between religious involvement and clinical status of patients with bipolar disorder

OBJECTIVE

Religion and spirituality are important coping strategies in depression but have been rarely studied within the context of bipolar disorder. The present study assessed the association between different forms of religious involvement and the clinical status of individuals treated for bipolar disorder.

METHODS

A cross-sectional observation study of follow-up data from a large cohort study of patients receiving care for bipolar disorder (n = 334) at an urban Veterans Affairs mental health clinic was conducted. Bivariate and multivariate analyses were performed to assess the association between public (frequency of church attendance), private (frequency of prayer/meditation), as well as subjective forms (influence of beliefs on life) of religious involvement and mixed, manic, depressed, and euthymic states when demographic, anxiety, alcohol abuse, and health indicators were controlled.

RESULTS

Multivariate analyses found significant associations between higher rates of prayer/meditation and participants in a mixed state [odds ratio (OR) = 1.29; 95% confidence interval (CI) = 1.10-1.52, chi square = 9.42, df = 14, p < 0.05], as well as lower rates of prayer/meditation and participants who were euthymic (OR = 0.84; 95% CI = 0.72-0.99, chi square = 4.60, df = 14, p < 0.05). Depression and mania were not associated with religious involvement.

CONCLUSIONS

Compared to patients with bipolar disorder in depressed, manic, or euthymic states, patients in mixed states have more active private religious lives. Providers should assess the religious activities of individuals with bipolar disorder in mixed states and how they may complement/deter ongoing treatment. Future longitudinal studies linking bipolar states, religious activities, and treatment-seeking behaviors are needed.

Perceived Vibration Strength in Mobile Devices: The Effect of Weight and Frequency

This paper addresses the question of strength perception for vibration signals used in mobile devices. Employing devices similar to standard cell phones and using pulsed vibration signals to combat adaptation effects, experiments were performed to study the effect of weight and underlying on perceived strength. Results shows that for the same measured acceleration on the device, a heavier box is perceived to vibrate with greater strength. Furthermore, signals with higher underlying frequency are perceived to be weaker for the same measured acceleration. While our results are consistent with previous studies, they are obtained for the specific condition of ungrounded, vibrating objects held in the hand. Our results suggest the need for a systematic correction law for use by designers to specify the vibratory characteristics of a device as a function of its weight and of the desired operating frequency.

Glycine regulates inflammatory markers modifying the energetic balance through PPAR and UCP-2

Obesity is widely recognized as cause of metabolic syndrome and cardiovascular disease. It is provoked by imbalance between the spending and consumption of energy associated with a chronic inflammatory condition due to excessive storage of fat tissue. Obese patients have an impaired inflammatory profile that contributes to the development of vascular complications, with fat tissue being partially responsible for controlling both processes: energy balance (through PPAR) and inflammatory condition (through inflammatory markers). White adipose tissue produces cytokines (IL-6, TNF-α, resistin, adiponectin, etc.) and participates in a broad spectrum of processes. Recently, glycine has been reported to have anti-inflammatory properties which reduce TNF-α and IL-6 levels and increase adiponectin in 3T3-L1 adipocytes and in fat tissue of obese mice. In this study, the possible regulatory role of glycine on some factors involved in storage and energy burning (PPAR-γ, PPAR-α, PPAR-δ and UCP-2) was analyzed in lean and monosodium glutamate-induced obese mice (MSG/Ob mice). Glycine clearly increased fat tissue PPAR-γ expression in lean but not in MSG/Ob mice. The PPAR-γ and PPAR-α liver expression was repressed in both groups of mice, while the expression of PPAR-δ decreased only in lean mice. Interestingly, glycine treatment also suppressed the expression of UCP-2, TNF-α and IL-6 in lean mice, and increased adiponectin and insulin serum levels. In conclusion, glycine regulates the production of inflammatory cytokines through PPAR-γ. These results provide clues on glycine signaling mechanisms as an anti-inflammatory agent that might be useful for treatment of metabolic and vascular complications associated to inflammation in obesity.

Round robin on Rietveld quantitative phase analysis of Portland cements

Interlaboratory studies on the precision and accuracy of Rietveld quantitative phase analysis (R-QPA) of mixtures of crystalline phases have already been carried out. However, cement-related materials are samples of variable complexity, ranging from three phases in white Portland clinkers to more than eight phases in grey cements, that need to be specifically investigated. Here, the results are reported from a round robin on the R-QPA of cement-related materials from laboratories with experience in this type of analysis. The aim of the work was to evaluate the levels of precision and accuracy associated with Portland clinkers and cements. Two sets of samples have been investigated, artificial mixtures and commercial samples. Artificial mixtures were prepared by mixing (weighing) synthesized single-crystalline phases in the appropriate proportions: (i) white clinker (Ca3SiO5, Ca2SiO4and Ca3Al2O6) and (ii) grey cement (Ca3SiO5, Ca2SiO4, Ca3Al2O6, Ca4Al2Fe2O10, CaCO3and CaSO4·2H2O). These two samples were used to assess the accuracy and uncertainty of the procedure, as an expected mineralogical phase fraction, the `true mineralogical percentage', is available under the assumption of negligible non-diffracting contents. In order to assess the validity and limitations of the Rietveld-based approach for cement materials, three commercial samples were measured: (i) white Portland clinker, (ii) grey Portland clinker and (iii) a type-I grey Portland cement. The samples studied have been chosen in order to cover most of the different typologies of binders. Reproducibilities and general uncertainty values, with a level of confidence of 95%, are reported and discussed.

Association of IL23R and ERAP1 genes with ankylosing spondylitis in a Portuguese population

OBJECTIVE

Association between ankylosing spondylitis (AS) and two genes, ERAP1 and IL23R, has recently been reported in North American and British populations. The population attributable risk fraction for ERAP1 in this study was 25%, and for IL23R, 9%. Confirmation of these findings to ERAP1 in other ethnic groups has not yet been demonstrated. We sought to test the association between single nucleotide polymorphisms (SNPs) in these genes and susceptibility to AS among a Portuguese population. We also investigated the role of these genes in clinical manifestations of AS, including age of symptom onset, the Bath Ankylosing Spondylitis Disease Activity, Metrology and Functional Indices, and the modified Stoke Ankylosing Spondylitis Spinal Score.

METHODS

The study was conducted on 358 AS cases and 285 ethnically matched Portuguese healthy controls. AS was defined according to the modified New York Criteria. Genotyping of IL23R and ERAP1 allelic variants was carried out with TaqMan allelic discrimination assays. Association analysis was performed using the Cochrane-Armitage and linear regression tests of genotypes as implemented in PLINK for dichotomous and quantitative variables respectively. A meta-analysis for Portuguese and previously published Spanish IL23R data was performed using the StatsDirect Statistical tools, by fixed and random effects models.

RESULTS

A total of 14 nsSNPs markers (8 for IL23R, 5 for ERAP1, 1 for LN-PEP) were analysed. Three markers (2 for IL23R and 1 for ERAP1) showed significant single-locus disease associations, confirming that the association of these genes with AS in the Portuguese population. The strongest associated SNP in IL23R was rs1004819 (OR=1.4, p=0.0049), and in ERAP1 was rs30187 (OR=1.26, p=0.035). The population attributable risk fractions in the Portuguese population for these SNPs are 11% and 9.7% respectively. No association was seen with any SNP in LN-PEP, which flanks ERAP1 and was associated with AS in the British population. No association was seen with clinical manifestations of AS.

CONCLUSION

These results show that IL23R and ERAP1 genes are also associated with susceptibility to AS in the Portuguese population, and that they contribute a significant proportion of the population risk for this disease.