505 research outputs found
Prevalence of Cam Morphology in Females with Femoroacetabular Impingement
Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. The purpose of this study was to determine the prevalence of cam morphology in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. Cam morphology is commonly assessed with the alpha angle, measured on radiographs. The purpose of this study was to determine the prevalence of cam morphology utilizing the alpha angle in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and January 2013 were retrospectively reviewed. Alpha (α) angles were measured on AP (anteroposterior) and lateral (Dunn 90°, cross-table lateral, and/or frog-leg lateral) plain radiographs by two blinded physicians, and the largest measured angle was used. Using Gosvig et al.’s classification, alpha angle was characterized as (pathologic > 57°), borderline (51-56°), subtle (46-50°), very subtle (43-45°), or normal (≤42°). Three hundred and ninety-one patients (438 hips) were analyzed (age 36.2 ± 12.3 years). Among the hips included, 35.6% were normal, 14.6% pathologic, 15.1% borderline, 14.6% subtle, and 20.1% very subtle. There was no correlation between alpha angle and patient age (R = 0.17) or body mass index (BMI) (R = 0.05). The intraclass correlation coefficient (ICC) for α-angle measurements was 0.84. Sixty-four percent of females in this cohort had an alpha angle > 42°. Subtle cam deformity plays a significant role in the pathoanatomy of female patients with symptomatic FAI. As the majority of revision hip arthroscopies are performed due to incomplete cam correction, hip arthroscopists need to be cognizant of and potentially surgically address these subtle lesions
A-to-I RNA editing in the earliest-diverging Eumetazoan phyla
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology and Evolution 34 (2017): 1890-1901, doi:10.1093/molbev/msx125.The highly conserved ADAR enzymes, found in all multicellular metazoans, catalyze the editing of mRNA transcripts by the deamination of adenosines to inosines. This type of editing has two general outcomes: site specific editing, which frequently leads to recoding, and clustered editing, which is usually found in transcribed genomic repeats. Here, for the first time, we looked for both editing of isolated sites and clustered, non-specific sites in a basal metazoan, the coral Acropora millepora during spawning event, in order to reveal its editing pattern. We found that the coral editome resembles the mammalian one: it contains more than 500,000 sites, virtually all of which are clustered in non-coding regions that are enriched for predicted dsRNA structures. RNA editing levels were increased during spawning and increased further still in newly released gametes. This may suggest that editing plays a role in introducing variability in coral gametes.This work was supported by the Australian Research Council (to PK), the European Research Council (grant 311257), the I-CORE Program of the Planning and Budgeting Committee in Israel (grants 41/11 and 1796/12), and the Israel Science Foundation (1380/14)
DNA 5-hydroxymethylcytosine in pediatric central nervous system tumors may impact tumor classification and is a positive prognostic marker
Background: Nucleotide-specific 5-hydroxymethylcytosine (5hmC) remains understudied in pediatric central nervous system (CNS) tumors. 5hmC is abundant in the brain, and alterations to 5hmC in adult CNS tumors have been reported. However, traditional approaches to measure DNA methylation do not distinguish between 5-methylcytosine (5mC) and its oxidized counterpart 5hmC, including those used to build CNS tumor DNA methylation classification systems. We measured 5hmC and 5mC epigenome-wide at nucleotide resolution in glioma, ependymoma, and embryonal tumors from children, as well as control pediatric brain tissues using tandem bisulfite and oxidative bisulfite treatments followed by hybridization to the Illumina Methylation EPIC Array that interrogates over 860,000 CpG loci. Results: Linear mixed effects models adjusted for age and sex tested the CpG-specific differences in 5hmC between tumor and non-tumor samples, as well as between tumor subtypes. Results from model-based clustering of tumors was used to test the relation of cluster membership with patient survival through multivariable Cox proportional hazards regression. We also assessed the robustness of multiple epigenetic CNS tumor classification methods to 5mC-specific data in both pediatric and adult CNS tumors. Compared to non-tumor samples, tumors were hypohydroxymethylated across the epigenome and tumor 5hmC localized to regulatory elements crucial to cell identity, including transcription factor binding sites and super-enhancers. Differentially hydroxymethylated loci among tumor subtypes tended to be hypermethylated and disproportionally found in CTCF binding sites and genes related to posttranscriptional RNA regulation, such as DICER1. Model-based clustering results indicated that patients with low 5hmC patterns have poorer overall survival and increased risk of recurrence. Our results suggest 5mC-specific data from OxBS-treated samples impacts methylation-based tumor classification systems giving new opportunities for further refinement of classifiers for both pediatric and adult tumors. Conclusions: We identified that 5hmC localizes to super-enhancers, and genes commonly implicated in pediatric CNS tumors were differentially hypohydroxymethylated. We demonstrated that distinguishing methylation and hydroxymethylation is critical in identifying tumor-related epigenetic changes. These results have implications for patient prognostication, considerations of epigenetic therapy in CNS tumors, and for emerging molecular neuropathology classification approaches
The Arabidopsis B3 domain protein VERNALIZATION1 is involved in processes essential for development with structural and mutational studies revealing its DNA binding surface
The B3 DNA-binding domain is a plant-specific domain found throughout the plant kingdom from the alga Chlamydomonas to grasses and flowering plants. Over 100 B3 domain-containing proteins are found in the model plant Arabidopsis thaliana, and one of these is critical for accelerating flowering in response to prolonged cold treatment, an epigenetic process called vernalization. Despite the specific phenotype of genetic vrn1 mutants, the VERNALIZATION1 (VRN1) protein localizes throughout the nucleus and shows sequence-nonspecific binding in vitro. In this work, we used a dominant repressor tag that overcomes genetic redundancy to show that VRN1 is involved in processes beyond vernalization that are essential for Arabidopsis development. To understand its sequence-nonspecific binding, we crystallized VRN1(208-341) and solved its crystal structure to 1.6 angstrom resolution using selenium/single-wavelength anomalous diffraction methods. The crystallized construct comprises the second VRN1 B3 domain and a preceding region conserved among VRN1 orthologs but absent in other B3 domains. We established the DNA-binding face using NMR and then mutated positively charged residues on this surface with a series of 16 Ala and Glu substitutions, ensuring that the protein fold was not disturbed using heteronuclear single quantum correlation NMR spectra. The triple mutant R249E/R289E/R296E was almost completely incapable of DNA binding in vitro. Thus, we have revealed that although VRN1 is sequence-nonspecific in DNA binding, it has a defined DNA-binding surface
The White Mountain Polarimeter Telescope and an Upper Limit on CMB Polarization
The White Mountain Polarimeter (WMPol) is a dedicated ground-based microwave
telescope and receiver system for observing polarization of the Cosmic
Microwave Background. WMPol is located at an altitude of 3880 meters on a
plateau in the White Mountains of Eastern California, USA, at the Barcroft
Facility of the University of California White Mountain Research Station.
Presented here is a description of the instrument and the data collected during
April through October 2004. We set an upper limit on -mode polarization of
14 (95% confidence limit) in the multipole range
. This result was obtained with 422 hours of observations of a 3
sky area about the North Celestial Pole, using a 42 GHz
polarimeter. This upper limit is consistent with polarization predicted
from a standard -CDM concordance model.Comment: 35 pages. 12 figures. To appear in ApJ
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Best Practices and Joint Calling of the HumanExome BeadChip: The CHARGE Consortium
Genotyping arrays are a cost effective approach when typing previously-identified genetic polymorphisms in large numbers of samples. One limitation of genotyping arrays with rare variants (e.g., minor allele frequency [MAF] <0.01) is the difficulty that automated clustering algorithms have to accurately detect and assign genotype calls. Combining intensity data from large numbers of samples may increase the ability to accurately call the genotypes of rare variants. Approximately 62,000 ethnically diverse samples from eleven Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium cohorts were genotyped with the Illumina HumanExome BeadChip across seven genotyping centers. The raw data files for the samples were assembled into a single project for joint calling. To assess the quality of the joint calling, concordance of genotypes in a subset of individuals having both exome chip and exome sequence data was analyzed. After exclusion of low performing SNPs on the exome chip and non-overlap of SNPs derived from sequence data, genotypes of 185,119 variants (11,356 were monomorphic) were compared in 530 individuals that had whole exome sequence data. A total of 98,113,070 pairs of genotypes were tested and 99.77% were concordant, 0.14% had missing data, and 0.09% were discordant. We report that joint calling allows the ability to accurately genotype rare variation using array technology when large sample sizes are available and best practices are followed. The cluster file from this experiment is available at www.chargeconsortium.com/main/exomechip
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