420 research outputs found

    Very small deletions within the NESP55 gene in pseudohypoparathyroidism type 1b

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    Pseudohypoparathyroidism (PHP) is caused by reduced expression of genes within the GNAS cluster, resulting in parathormone resistance. The cluster contains multiple imprinted transcripts, including the stimulatory G protein Ī± subunit (Gs-Ī±) and NESP55 transcript preferentially expressed from the maternal allele, and the paternally expressed XLas, A/B and antisense transcripts. PHP1b can be caused by loss of imprinting affecting GNAS A/B alone (associated with STX16 deletion), or the entire GNAS cluster (associated with deletions of NESP55 in a minority of cases). We performed targeted genomic next-generation sequencing (NGS) of the GNAS cluster to seek variants and indels underlying PHP1b. Seven patients were sequenced by hybridisation-based capture and fourteen more by long-range PCR and transposon-mediated insertion and sequencing. A bioinformatic pipeline was developed for variant and indel detection. In one family with two affected siblings, and in a second family with a single affected individual, we detected maternally inherited deletions of 40 and 33 bp, respectively, within the deletion previously reported in rare families with PHP1b. All three affected individuals presented with atypically severe PHP1b; interestingly, the unaffected mother in one family had the detected deletion on her maternally inherited allele. Targeted NGS can reveal sequence changes undetectable by current diagnostic methods. Identification of genetic mutations underlying epigenetic changes can facilitate accurate diagnosis and counselling, and potentially highlight genetic elements critical for normal imprint settin

    Tailoring electrostatic surface potential and adsorption capacity of porous ceramics by silica-assisted sintering

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    In this study, we apply silica-assisted sintering to develop porous yttria stabilized zirconia (YSZ) ceramics with tailored electrostatic surface potential and adsorption capacity as a promising alternative to chemical functionalization. The porous bodies were formed by partial sintering at 1050 Ā°C and were investigated regarding the influence of admixtures of silica particles on sintering behavior, microstructural evolution and the resulting mechanical and surface properties of the material, particularly the surface potential. With increasing silica concentration, the sintering mechanism was gradually changed from solid state to liquid phase sintering, due to the wetting of YSZ by liquid silica and a resulting inhibition of mass transport, particle growth and diffusion-induced densification. Most importantly, due to the silica layer development, the isoelectric point (IEP) of the YSZ/silica material surfaces was systematically shifted towards the IEP of silica from pH 9.4 to 1.2 resulting in a more pronounced negative surface potential at neutral pH. The relationship between surface IEP and silica concentration was mathematically described using the IEPs of the starting materials, the YSZ particle radius and the glass layer thickness. This estimation allows us to tailor the surface coverage of the YSZ matrix with silica as well as the resulting electrostatic surface potential. We further demonstrate how the applied processing route can be effectively used to develop ceramics with specified adsorption capacities for protein immobilization for use in filtration, bioprocessing or biomaterial applications. Ā© 202

    Screening Diabetic and Hypertensive Patients for Ocular Pathology using Telemedicine Technology in Rural West Virginia: A Retrospective Chart Review

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    Abstract: Purpose: There is a disparity between the number of people who need healthcare and availability of medical services in rural areas. This paper describes the experience of using telemedicine technologies for ophthalmologic evaluation in diabetic and hypertensive patients presenting to a community health center in rural West Virginia. Methods: A registered nurse at a community health center in McDowell County, WV was trained to use a retinal camera to capture high-resolution digital images of the retina. Patients with diabetes or hypertension were screened during their routine primary care visits. Retinal photos were transmitted to an ophthalmologist for review and reports from the screenings were returned with instruction for follow-up care or specialist referral when indicated. Findings: A retrospective chart review of 643 patients with diabetes or hypertension who were screened for ocular problems from October 2003 to December 2009 was completed. 44.8% of patients who were screened in the primary care center were identified as having 1 of 34 types of eye pathology that were previously unknown,of which 33% of patients were recommended to seek prompt attention by a retina consultant or glaucoma specialist for suspected ocular pathology. Conclusions: Our review demonstrates the actual benefits of telemedicine in the effective screening of diabetic and hypertensive patients for eye pathology,and our experience suggests that using distance medicine and telemedicine technologies is valuable for screening rural populations

    Design of epidermal growth factor immobilization on 3D biocompatible scaffolds to promote tissue repair and regeneration

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    Exogenous application of human epidermal growth factor (hEGF) stimulates epidermal wound healing. The aim of this study was to develop bioconjugates based on hEGF mimicking the protein in its native state and thus suitable for tissue engineering applications, in particular for treating skin-related disorders as burns. Ribonuclease A (RNase A) was used to investigate a number of different activated-agarose carriers: cyanogen bromide (CNBr)-activated-agarose and glyoxyl-agarose showed to preserve the appropriate orientation of the protein for receptor binding. EGF was immobilized on these carriers and immobilization yield was evaluated (100% and 12%, respectively). A peptide mapping of unbound protein regions was carried out by LCā€“MS to take evidence of the residues involved in the immobilization and, consequently, the flexibility and surface accessibility of immobilized EGF. To assess cell proliferative activities, 10, 25, 50, and 100Ā ng/mL of each immobilized EGF sample were seeded on fibroblast cells and incubated for 24, 48 and 72Ā h. The immobilized growth factor showed significantly high cell proliferative activity at 50 and 100Ā ng/mL compared to control and soluble EGF. Although both of the immobilized samples show dose-dependency when seeded with high number of fibroblast cells, CNBr-agarose-EGF showed a significantly high activity at 100Ā ng/mL and 72Ā h incubation, compared to glyoxyl-agarose-EGF

    Face Anti-Spoofing Using Texture-Based Techniques and Filtering Methods

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    User authentication for an accurate biometric system is the demand of the hour in today's world. When somebody attempts to take on the appearance of another person by introducing a phoney face or video before the face detection camera and gets illegitimate access, a face presentation attack usually happens. To effectively protect the privacy of a person, it is very critical to build a face authentication and anti-spoofing system. This paper introduces a novel and appealing face spoof detection technique, which is primarily based on the study of contrast and dynamic texture features of both seized and spoofed photos. Valid identification of photo spoofing is anticipated here. A modified version of the DoG filtering method, and local binary pattern variance (LBPV) based technique, which is invariant to rotation, are designated to be used in this paper. Support vector machine (SVM) is used when feature vectors are extracted for further analysis. The publicly available NUAA photo-imposter database is adapted to test the system, which includes facial images with different illumination and area. The accuracy of the method can be assessed using the false acceptance rate (FAR) and false rejection rate (FRR). The results express that our method performs better on key indices compared to other state-of-the-art techniques following the provided evaluation protocols tested on a similar dataset

    Development of childhood asthma prediction models using machine learning approaches

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    Background: Respiratory symptoms are common in early life and often transient. It is difficult to identify in which children these will persist and result in asthma. Machine learning (ML) approaches have the potential for better predictive performance and generalisability over existing childhood asthma prediction models. This study applied ML approaches to predict school-age asthma (age 10) in early life (Childhood Asthma Prediction in Early life, CAPE model) and at preschool age (Childhood Asthma Prediction at Preschool age, CAPP model). Methods: Clinical and environmental exposure data was collected from children enrolled in the Isle of Wight Birth Cohort (NĀ =Ā 1368, āˆ¼15% asthma prevalence). Recursive Feature Elimination (RFE) identified an optimal subset of features predictive of school-age asthma for each model. Seven state-of-the-art ML classification algorithms were used to develop prognostic models. Training was performed by applying fivefold cross-validation, imputation, and resampling. Predictive performance was evaluated on the test set. Models were further externally validated in the Manchester Asthma and Allergy Study (MAAS) cohort. Results: RFE identified eight and twelve predictors for the CAPE and CAPP models, respectively. Support Vector Machine (SVM) algorithms provided the best performance for both the CAPE (area under the receiver operating characteristic curve, AUCĀ =Ā 0.71) and CAPP (AUCĀ =Ā 0.82) models. Both models demonstrated good generalisability in MAAS (CAPE 8-yearĀ =Ā 0.71, 11-yearĀ =Ā 0.71, CAPP 8-yearĀ =Ā 0.83, 11-yearĀ =Ā 0.79) and excellent sensitivity to predict a subgroup of persistent wheezers. Conclusion: Using ML approaches improved upon the predictive performance of existing regression-based models, with good generalisability and ability to rule in asthma and predict persistent wheeze.</p

    Bioactivity in silica/poly(Ī³-glutamic acid) solā€“gel hybrids through calcium chelation

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    Bioactive glasses and inorganic/organic hybrids have great potential as biomedical implant materials. Solā€“gel hybrids with interpenetrating networks of silica and biodegradable polymers can combine the bioactive properties of a glass with the toughness of a polymer. However, traditional calcium sources such as calcium nitrate and calcium chloride are unsuitable for hybrids. In this study calcium was incorporated by chelation to the polymer component. The calcium salt form of poly(Ī³-glutamic acid) (Ī³CaPGA) was synthesized for use as both a calcium source and as the biodegradable toughening component of the hybrids. Hybrids of 40 wt.% Ī³CaPGA were successfully formed and had fine scale integration of Ca and Si ions, according to secondary ion mass spectrometry imaging, indicating a homogeneous distribution of organic and inorganic components. 29Si magic angle spinning nuclear magnetic resonance data demonstrated that the network connectivity was unaltered with changing polymer molecular weight, as there was no perturbation to the overall Si speciation and silica network formation. Upon immersion in simulated body fluid a hydroxycarbonate apatite surface layer formed on the hybrids within 1 week. The polymer molecular weight (Mw 30ā€“120 kDa) affected the mechanical properties of the resulting hybrids, but all hybrids had large strains to failure, >26%, and compressive strengths, in excess of 300 MPa. The large strain to failure values showed that Ī³CaPGA hybrids exhibited non-brittle behaviour whilst also incorporating calcium. Thus calcium incorporation by chelation to the polymer component is justified as a novel approach in hybrids for biomedical materials

    The interplay of DNA methylation over time with Th2 pathway genetic variants on asthma risk and temporal asthma transition

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    BackgroundGenetic effects on asthma of genes in the T-helper 2 (Th2) pathway may interact with epigenetic factors including DNA methylation. We hypothesized that interactions between genetic variants and methylation in genes in this pathway (IL4, IL4R, IL13, GATA3, and STAT6) influence asthma risk, that such influences are age-dependent, and that methylation of some CpG sites changes over time in accordance with asthma transition. We tested these hypotheses in subsamples of girls from a population-based birth cohort established on the Isle of Wight, UK, in 1989.ResultsLogistic regression models were applied to test the interaction effect of DNA methylation and SNP on asthma within each of the five genes. Bootstrapping was used to assess the models identified. From 1,361 models fitted at each age of 10 and 18 years, 8 models, including 4 CpGs and 8 SNPs, showed potential associations with asthma risk. Of the 4 CpGs, methylation of cg26937798 (IL4R) and cg23943829 (IL4) changes between ages 10 and 18 (both higher at 10; P?=?9.14?Ɨ?10?6 and 1.07?Ɨ?10?5, respectively).At age 10, the odds of asthma tended to decrease as cg12405139 (GATA3) methylation increased (log-OR?=??12.15; P?=?0.049); this effect disappeared by age 18. At age 18, methylation of cg09791102 (IL4R) was associated with higher risk of asthma among subjects with genotype GG compared to AG (P?=?0.003), increased cg26937798 methylation among subjects with rs3024685 (IL4R) genotype AA (P?=?0.003) or rs8832 (IL4R) genotype GG (P?=?0.01) was associated with a lower asthma risk; these CpGs had no effect at age 10. Increasing cg26937798 methylation over time possibly reduced the risk of positive asthma transition (asthma-free at age 10???asthma at age 18; log-OR?=??3.11; P?=?0.069) and increased the likelihood of negative transition (asthma at age 10???asthma-free at age 18; log-OR?=?3.97; P?=?0.074).ConclusionsThe interaction of DNA methylation and SNPs in Th2 pathway genes is likely to contribute to asthma risk. This effect may vary with age. Methylation of some CpGs changed over time, which may influence asthma transition
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