176 research outputs found
Clinical Characteristics and Treatment Response to Radiotherapy of Optic Nerve Sheath Meningiomas
Recent reports of success with conventional, conformal, and stereotactic radiotherapy in stabilizing or improving visual function in patients with primary optic nerve sheath meningiomas have reduced the controversy surrounding the optimal treatment of these rare tumors. To analyze trends in the clinical presentation and diagnosis of optic nerve sheath meningiomas and to evaluate the effectiveness and side-effect profile of three-dimensional conformal radiotherapy versus other treatment modalities, a retrospective chart review was performed on patients with optic nerve sheath meningiomas treated at The Eye Care Group and at the Department of Therapeutic Radiology, Yale University School of Medicine, in New Haven, CT, up to September 2006. Fourteen patients were identified, with a mean age of 45.6 (range 16-63). Abnormal color vision and proptosis were less frequent than in historical comparison with published series. Four patients had normal initial imaging, underscoring the importance of clinical suspicion and appropriate imaging protocols. One patient was observed only, and one received surgery as primary treatment. Nine patients were treated with three-dimensional conformal radiotherapy at Yale, one with conformal intensity-modulated radiotherapy at Yale, one with three-dimensional conformal radiotherapy at another center, and one with stereotactic fractionated radiotherapy at another center. The overall visual and radiographic control rate for patients treated with radiotherapy was 100% with one late complication of mild dry-eye syndrome and one of pituitary toxicity. Outcomes in this series compare favorably with those in the published literature
Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon.
An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus) to elevated dietary selenium (Se) based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70), and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet). The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM) were raised in indoor tanks provided with flow through freshwater (18-19 °C). There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05). Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks) on muscle RNA/DNA ratio (P ≥ 0.05), the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks) and higher levels (40.1 and 77.7 mg Se/kg diet) of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the current study suggest that a mechanism involved with the activation of stress protein production and apoptosis protects white sturgeon from the lethal effect of Se
Genetic diversity and thermal performance in invasive and native populations of African fig flies
During biological invasions, invasive populations can suffer losses of genetic diversity that are predicted to negatively impact their fitness/performance. Despite examples of invasive populations harboring lower diversity than conspecific populations in their native range, few studies have linked this lower diversity to a decrease in fitness. Using genome sequences, we show that invasive populations of the African fig fly, Zaprionus indianus, have less genetic diversity than conspecific populations in their native range and that diversity is proportionally lower in regions of the genome experiencing low recombination rates. This result suggests that selection may have played a role in lowering diversity in the invasive populations. We next use interspecific comparisons to show that genetic diversity remains relatively high in invasive populations of Z. indianus when compared to other closely related species. By comparing genetic diversity in orthologous gene regions, we also show that the genome-wide landscape of genetic diversity differs between invasive and native populations of Z. indianus, indicating that invasion not only affects amounts of genetic diversity, but also how that diversity is distributed across the genome. Finally, we use parameter estimates from thermal performance curves measured for 13 species of Zaprionus to show that Z. indianus has the broadest thermal niche of measured species, and that performance does not differ between invasive and native populations. These results illustrate how aspects of genetic diversity in invasive species can be decoupled from measures of fitness, and that a broad thermal niche may have helped facilitate Z. indianus's range expansion.Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: Dimensions of Biodiversity award number 1737752Data used to generate genome annotations was generated by extracting whole RNA from groups of ~5 adult flies (24 hours after eclosion). Transcripts were assembed using Trinity (Grabherr et al. 2011; Hass et al. 2013) and annotations were generated using the MAKER pipeline (v3.01.02; Holt and Yandell 2011; Campbell et al. 2014).
Data on thermal performance we generated in the lab under controlled conditions. All scripts used to fit thermal performance curves are given in this Dryad deposit. Software available for the method used are available at github.com/silastittes/performr
Comparing genomic and epigenomic features across species using the WashU Comparative Epigenome Browser
Genome browsers have become an intuitive and critical tool to visualize and analyze genomic features and data. Conventional genome browsers display data/annotations on a single reference genome/assembly; there are also genomic alignment viewer/browsers that help users visualize alignment, mismatch, and rearrangement between syntenic regions. However, there is a growing need for a comparative epigenome browser that can display genomic and epigenomic data sets across different species and enable users to compare them between syntenic regions. Here, we present the WashU Comparative Epigenome Browser. It allows users to load functional genomic data sets/annotations mapped to different genomes and display them over syntenic regions simultaneously. The browser also displays genetic differences between the genomes from single-nucleotide variants (SNVs) to structural variants (SVs) to visualize the association between epigenomic differences and genetic differences. Instead of anchoring all data sets to the reference genome coordinates, it creates independent coordinates of different genome assemblies to faithfully present features and data mapped to different genomes. It uses a simple, intuitive genome-align track to illustrate the syntenic relationship between different species. It extends the widely used WashU Epigenome Browser infrastructure and can be expanded to support multiple species. This new browser function will greatly facilitate comparative genomic/epigenomic research, as well as support the recent growing needs to directly compare and benchmark the T2T CHM13 assembly and other human genome assemblies
Collapse and folding of pressurized rings in two dimensions
Hydrostatically pressurized circular rings confined to two dimensions (or
cylinders constrained to have only z-independent deformations) undergo Euler
type buckling when the outside pressure exceeds a critical value. We perform a
stability analysis of rings with arc-length dependent bending moduli and
determine how weakened bending modulus segments affect the buckling critical
pressure. Rings with a 4-fold symmetric modulation are particularly susceptible
to collapse. In addition we study the initial post-buckling stages of the
pressurized rings to determine possible ring folding patterns
WashU Epigenome Browser update 2022
WashU Epigenome Browser (https://epigenomegateway.wustl.edu/browser/) is a web-based genomic data exploration tool that provides visualization, integration, and analysis of epigenomic datasets. The newly renovated user interface and functions have enabled researchers to engage with the browser and genomic data more efficiently and effectively since 2018. Here, we introduce a new integrated panel design in the browser that allows users to interact with 1D (genomic features), 2D (such as Hi-C), 3D (genome structure), and 4D (time series) data in a single web page. The browser can display three-dimensional chromatin structures with the 3D viewer module. The 4D tracks, called \u27Dynamic\u27 tracks, animatedly display time-series data, allowing for a more striking visual impact to identify the gene or genomic region candidates as a function of time. Genomic data, such as annotation features, numerical values, and chromatin interaction data can all be viewed in the dynamic track mode. Imaging data from microscopy experiments can also be displayed in the browser. In addition to software development, we continue to service and expand the data hubs we host for large consortia including 4DN, Roadmap Epigenomics, TaRGET and ENCODE, among others. Our growing user/developer community developed additional track types as plugins, such as qBed and dynseq tracks, which extend the utility of the browser. The browser serves as a foundation for additional genomics platforms including the WashU Virus Genome Browser (for COVID-19 research) and the Comparative Genome Browser. The WashU Epigenome Browser can also be accessed freely through Amazon Web Services at https://epigenomegateway.org/
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