606 research outputs found
Type I interferon responses of common carp strains with different levels of resistance to koi herpesvirus disease during infection with CyHV-3 or SVCV
Carp from breeding strains with different genetic background present diverse levels of resistance to viral pathogens. Carp strains of Asian origin, currently being treated as Cyprinus rubrofuscus L., especially Amur wild carp (AS), were proven to be more resistant to koi herpesvirus disease (KHVD; caused by cyprinid herpesvirus 3, CyHV-3) than strains originating from Europe and belonging to Cyprinus carpio L., like the Prerov scale carp (PS) or koi carp from a breed in the Czech Republic. We hypothesised that it can be associated with a higher magnitude of type I interferon (IFN) response as a first line of innate defence mechanisms against viral infections. To evaluate this hypothesis, four strains of common carp (AS, Rop, PS and koi) were challenged using two viral infection models: Rhabdovirus SVCV (spring viremia of carp virus) and alloherpesvirus CyHV-3. The infection with SVCV induced a low mortality rate and the most resistant was the Rop strain (no mortalities), whereas the PS strain was the most susceptible (survival rate of 78%). During CyHV-3 infection, Rop and AS strains performed better (survival rates of 78% and 53%, respectively) than PS and koi strains (survival rates of 35% and 10%, respectively). The evaluation of virus loads and virus replication showed significant differences between the carp strains, which correlated with the mortality rate. The evaluation of type I IFN responses showed that there were fundamental differences between the virus infection models. While responses to the SVCV were high, the CyHV-3 generally induced low responses. Furthermore, the results demonstrated that the magnitude of type I IFN responses did not correlate with a higher resistance in infected carp. In the case of a CyHV-3 infection, reduced type I IFN responses could be related to the potential ability of the virus to interfere with cellular sensing of foreign nucleic acids. Taken together, the results broaden our understanding of how common carp from different genetic lines interact with various viral pathogens
A functional genomic model for predicting prognosis in idiopathic pulmonary fibrosis
Background: The course of disease for patients with idiopathic pulmonary fibrosis (IPF) is highly heterogeneous. Prognostic models rely on demographic and clinical characteristics and are not reproducible. Integrating data from genomic analyses may identify novel prognostic models and provide mechanistic insights into IPF. Methods: Total RNA of peripheral blood mononuclear cells was subjected to microarray profiling in a training (45 IPF individuals) and two independent validation cohorts (21 IPF/10 controls, and 75 IPF individuals, respectively). To identify a gene set predictive of IPF prognosis, we incorporated genomic, clinical, and outcome data from the training cohort. Predictor genes were selected if all the following criteria were met: 1) Present in a gene co-expression module from Weighted Gene Co-expression Network Analysis (WGCNA) that correlated with pulmonary function (p 1.5 and false discovery rate (FDR) < 2 %; and 3) Predictive of mortality (p < 0.05) in univariate Cox regression analysis. "Survival risk group prediction" was adopted to construct a functional genomic model that used the IPF prognostic predictor gene set to derive a prognostic index (PI) for each patient into either high or low risk for survival outcomes. Prediction accuracy was assessed with a repeated 10-fold cross-validation algorithm and independently assessed in two validation cohorts through multivariate Cox regression survival analysis. Results: A set of 118 IPF prognostic predictor genes was used to derive the functional genomic model and PI. In the training cohort, high-risk IPF patients predicted by PI had significantly shorter survival compared to those labeled as low-risk patients (log rank p < 0.001). The prediction accuracy was further validated in two independent cohorts (log rank p < 0.001 and 0.002). Functional pathway analysis revealed that the canonical pathways enriched with the IPF prognostic predictor gene set were involved in T-cell biology, including iCOS, T-cell receptor, and CD28 signaling. Conclusions: Using supervised and unsupervised analyses, we identified a set of IPF prognostic predictor genes and derived a functional genomic model that predicted high and low-risk IPF patients with high accuracy. This genomic model may complement current prognostic tools to deliver more personalized care for IPF patients
The pseudogap: friend or foe of high Tc?
Although nineteen years have passed since the discovery of high temperature
superconductivity, there is still no consensus on its physical origin. This is
in large part because of a lack of understanding of the state of matter out of
which the superconductivity arises. In optimally and underdoped materials, this
state exhibits a pseudogap at temperatures large compared to the
superconducting transition temperature. Although discovered only three years
after the pioneering work of Bednorz and Muller, the physical origin of this
pseudogap behavior and whether it constitutes a distinct phase of matter is
still shrouded in mystery. In the summer of 2004, a band of physicists gathered
for five weeks at the Aspen Center for Physics to discuss the pseudogap. In
this perspective, we would like to summarize some of the results presented
there and discuss its importance in the context of strongly correlated electron
systems.Comment: expanded version, 20 pages, 11 figures, to be published, Advances in
Physic
Three-dimensional kinematic motion analysis of a daily activity drinking from a glass: a pilot study
BACKGROUND: Development of reliable and objective evaluation methods is required, particularly for natural and goal-oriented upper-extremity tasks. Three-dimensional imaging measurement techniques have turned out to be a powerful tool for a quantitative and qualitative assessment of multijoint movements. The purpose of this study was to develop and test a method of three-dimensional motion analysis for the activity "drinking from a glass" and describe the drinking task with kinematic variables in control subjects. METHODS: A protocol was developed for the drinking activity including the set-up of cameras and positions of the markers and the subject. The drinking task included reaching, forward transport with glass, drinking, back transport and returning the hand to the initial position. An optoelectronic system was used for the three-dimensional kinematic motion capture. Movement times, velocities, joint angles and interjoint coordination for shoulder and elbow were computed and analyzed for twenty control subjects. Test-retest consistency was evaluated for six subjects. RESULTS: The test protocol showed good consistency in test-retest. Phase definitions for the drinking task were defined and verified. Descriptive kinematic variables were obtained for movement times, positions, velocities and joint angles for shoulder and elbow joint. Interjoint coordination between shoulder and elbow joint in reaching phase showed a high correlation. CONCLUSION: This study provides a detailed description of the three-dimensional kinematic analysis of the drinking task. Our approach to investigate and analyze a goal-oriented daily activity has a great clinical potential. Consequently, the next step is to use and test this protocol on persons with impairments and disabilities from upper extremities
The HLA class II allele DRB1*1501 is over-represented in patients with idiopathic pulmonary fibrosis
Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and medically refractory lung disease with a grim prognosis. Although the etiology of IPF remains perplexing, abnormal adaptive immune responses are evident in many afflicted patients. We hypothesized that perturbations of human leukocyte antigen (HLA) allele frequencies, which are often seen among patients with immunologic diseases, may also be present in IPF patients. Methods/Principal Findings: HLA alleles were determined in subpopulations of IPF and normal subjects using molecular typing methods. HLA-DRB1*15 was over-represented in a discovery cohort of 79 Caucasian IPF subjects who had lung transplantations at the University of Pittsburgh (36.7%) compared to normal reference populations. These findings were prospectively replicated in a validation cohort of 196 additional IPF subjects from four other U.S. medical centers that included both ambulatory patients and lung transplantation recipients. High-resolution typing was used to further define specific HLA-DRB1*15 alleles. DRB1*1501 prevalence in IPF subjects was similar among the 143 ambulatory patients and 132 transplant recipients (31.5% and 34.8%, respectively, p = 0.55). The aggregate prevalence of DRB1*1501 in IPF patients was significantly greater than among 285 healthy controls (33.1% vs. 20.0%, respectively, OR 2.0; 95%CI 1.3-2.9, p = 0.0004). IPF patients with DRB1*1501 (n = 91) tended to have decreased diffusing capacities for carbon monoxide (DLCO) compared to the 184 disease subjects who lacked this allele (37.8Β±1.7% vs. 42.8Β±1.4%, p = 0.036). Conclusions/Significance: DRB1*1501 is more prevalent among IPF patients than normal subjects, and may be associated with greater impairment of gas exchange. These data are novel evidence that immunogenetic processes can play a role in the susceptibility to and/or manifestations of IPF. Findings here of a disease association at the HLA-DR locus have broad pathogenic implications, illustrate a specific chromosomal area for incremental, targeted genomic study, and may identify a distinct clinical phenotype among patients with this enigmatic, morbid lung disease
Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline β Update 2020
1. ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. Strong recommendation, high quality evidence. ESGE/ESGAR do not recommend barium enema in this setting. Strong recommendation, high quality evidence. 2. ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors. Strong recommendation, low quality evidence. ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete. Weak recommendation, low quality evidence. 3. When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms. Strong recommendation, high quality evidence. Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation. Very low quality evidence. ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms. Strong recommendation, high quality evidence. In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms. Weak recommendation, low quality evidence. 4. Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors. Strong recommendation, high quality evidence. ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer. Weak recommendation, low quality evidence. 5. ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs. Strong recommendation, moderate quality evidence. ESGE/ESGAR also suggest the use of CCE in this setting based on availability. Weak recommendation, moderate quality evidence. 6. ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in this setting. Very low quality evidence. 7. ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible. Weak recommendation, low quality evidence. There is insufficient evidence to recommend CCE in post-polypectomy surveillance. Very low quality evidence. 8. ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation. Strong recommendation, low quality evidence. 9. ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp β₯6 mm detected at CTC or CCE. Follow-up CTC may be clinically considered for 6β9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia. Strong recommendation, moderate quality evidence.Source and scop
Levetiracetam Reverses Synaptic Deficits Produced by Overexpression of SV2A
Levetiracetam is an FDA-approved drug used to treat epilepsy and other disorders of the nervous system. Although it is known that levetiracetam binds the synaptic vesicle protein SV2A, how drug binding affects synaptic functioning remains unknown. Here we report that levetiracetam reverses the effects of excess SV2A in autaptic hippocampal neurons. Expression of an SV2A-EGFP fusion protein produced a βΌ1.5-fold increase in synaptic levels of SV2, and resulted in reduced synaptic release probability. The overexpression phenotype parallels that seen in neurons from SV2 knockout mice, which experience severe seizures. Overexpression of SV2A also increased synaptic levels of the calcium-sensor protein synaptotagmin, an SV2-binding protein whose stability and trafficking are regulated by SV2. Treatment with levetiracetam rescued normal neurotransmission and restored normal levels of SV2 and synaptotagmin at the synapse. These results indicate that changes in SV2 expression in either direction impact neurotransmission, and suggest that levetiracetam may modulate SV2 protein interactions
Disruption of Ant-Aphid Mutualism in Canopy Enhances the Abundance of Beetles on the Forest Floor
Ant-aphid mutualism is known to play a key role in the structure of the arthropod community in the tree canopy, but its possible ecological effects for the forest floor are unknown. We hypothesized that aphids in the canopy can increase the abundance of ants on the forest floor, thus intensifying the impacts of ants on other arthropods on the forest floor. We tested this hypothesis in a deciduous temperate forest in Beijing, China. We excluded the aphid-tending ants Lasius fuliginosus from the canopy using plots of varying sizes, and monitored the change in the abundance of ants and other arthropods on the forest floor in the treated and control plots. We also surveyed the abundance of ants and other arthropods on the forest floor to explore the relationships between ants and other arthropods in the field. Through a three-year experimental study, we found that the exclusion of ants from the canopy significantly decreased the abundance of ants on the forest floor, but increased the abundance of beetles, although the effect was only significant in the large ant-exclusion plot (80*60 m). The field survey showed that the abundance of both beetles and spiders was negatively related to the abundance of ants. These results suggest that aphids located in the tree canopy have indirect negative effects on beetles by enhancing the ant abundance on the forest floor. Considering that most of the beetles in our study are important predators, the ant-aphid mutualism can have further trophic cascading effects on the forest floor food web
Transmission electron microscopy characterization of fluorescently labelled amyloid Ξ² 1-40 and Ξ±-synuclein aggregates
<p>Abstract</p> <p>Background</p> <p>Fluorescent tags, including small organic molecules and fluorescent proteins, enable the localization of protein molecules in biomedical research experiments. However, the use of these labels may interfere with the formation of larger-scale protein structures such as amyloid aggregates. Therefore, we investigate the effects of some commonly used fluorescent tags on the morphologies of fibrils grown from the Alzheimer's disease-associated peptide Amyloid Ξ² 1-40 (AΞ²40) and the Parkinson's disease-associated protein Ξ±-synuclein (Ξ±S).</p> <p>Results</p> <p>Using transmission electron microscopy (TEM), we verify that N-terminal labeling of AΞ²40 with AMCA, TAMRA, and Hilyte-Fluor 488 tags does not prevent the formation of protofibrils and amyloid fibrils of various widths. We also measure the two-photon action cross-section of AΞ²40 labelled with Hilyte Fluor 488 and demonstrate that this tag is suitable for use with two-photon fluorescence techniques. Similarly, we find that Alexa Fluor 488 labelling of Ξ±S variant proteins near either the N or C terminus (position 9 or 130) does not interfere with the formation of amyloid and other types of Ξ±S fibrils. We also present TEM images of fibrils grown from Ξ±S C-terminally labelled with enhanced green fluorescent protein (EGFP). Near neutral pH, two types of Ξ±S-EGFP fibrils are observed via TEM, while denaturation of the EGFP tag leads to the formation of additional species.</p> <p>Conclusions</p> <p>We demonstrate that several small extrinsic fluorescent tags are compatible with studies of amyloid protein aggregation. However, although fibrils can be grown from Ξ±S labelled with EGFP, the conformation of the fluorescent protein tag affects the observed aggregate morphologies. Thus, our results should assist researchers with label selection and optimization of solution conditions for aggregation studies involving fluorescence techniques.</p
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