253 research outputs found
Method for replica-plating Neurospora
Method for replica-plating Neurospor
Reliability of 3-Dimensional Measures of Single-Leg Cross Drop Landing Across 3 Different Institutions: Implications for Multicenter Biomechanical and Epidemiological Research on ACL Injury Prevention
Background: Anterior cruciate ligament (ACL) injuries are physically and financially devastating but affect a relatively small percentage of the population. Prospective identification of risk factors for ACL injury necessitates a large sample size; therefore, study of this injury would benefit from a multicenter approach.
Purpose: To determine the reliability of kinematic and kinetic measures of a single-leg cross drop task across 3 institutions.
Study Design: Controlled laboratory study.
Methods: Twenty-five female high school volleyball players participated in this study. Three-dimensional motion data of each participant performing the single-leg cross drop were collected at 3 institutions over a period of 4 weeks. Coefficients of multiple correlation were calculated to assess the reliability of kinematic and kinetic measures during the landing phase of the movement.
Results: Between-centers reliability for kinematic waveforms in the frontal and sagittal planes was good, but moderate in the transverse plane. Between-centers reliability for kinetic waveforms was good in the sagittal, frontal, and transverse planes.
Conclusion: Based on these findings, the single-leg cross drop task has moderate to good reliability of kinematic and kinetic measures across institutions after implementation of a standardized testing protocol.
Clinical Relevance: Multicenter collaborations can increase study numbers and generalize results, which is beneficial for studies of relatively rare phenomena, such as ACL injury. An important step is to determine the reliability of risk assessments across institutions before a multicenter collaboration can be initiated
Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes
The contemporary diagnosis of paraneoplastic neurologic syndromes (PNSs) requires an increasing understanding of their clinical, immunologic, and oncologic heterogeneity. The 2004 PNS criteria are partially outdated due to advances in PNS research in the last 16 years leading to the identification of new phenotypes and antibodies that have transformed the diagnostic approach to PNS. Here, we propose updated diagnostic criteria for PNS.A panel of experts developed by consensus a modified set of diagnostic PNS criteria for clinical decision making and research purposes. The panel reappraised the 2004 criteria alongside new knowledge on PNS obtained from published and unpublished data generated by the different laboratories involved in the project.The panel proposed to substitute "classical syndromes" with the term "high-risk phenotypes" for cancer and introduce the concept of "intermediate-risk phenotypes." The term "onconeural antibody" was replaced by "high risk" (>70% associated with cancer) and "intermediate risk" (30%-70% associated with cancer) antibodies. The panel classified 3 levels of evidence for PNS: definite, probable, and possible. Each level can be reached by using the PNS-Care Score, which combines clinical phenotype, antibody type, the presence or absence of cancer, and time of follow-up. With the exception of opsoclonus-myoclonus, the diagnosis of definite PNS requires the presence of high- or intermediate-risk antibodies. Specific recommendations for similar syndromes triggered by immune checkpoint inhibitors are also provided.The proposed criteria and recommendations should be used to enhance the clinical care of patients with PNS and to encourage standardization of research initiatives addressing PNS.Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology
Selection criteria for patients with chronic ankle instability in controlled research: a position statement of the International Ankle Consortium
While research on chronic ankle instability (CAI) and awareness of its impact on society and health care systems has grown substantially in the last 2 decades, the inconsistency in participant or patient selection criteria across studies presents
a potential obstacle to addressing the problem properly. This major gap within the literature limits the ability to generalize this evidence to the target patient population. Therefore, there is a need to provide standards for patient or participant selection criteria in research focused on CAI with justifications using the best available evidence. The International Ankle Consortium provides this position paper to present and discuss an endorsed set of selection criteria for patients with CAI based on the best available evidence to be used in future research and study designs. These recommendations will enhance the
validity of research conducted in this clinical population with the end goal of bringing the research evidence to the clinician and patient
Deletions in VANGL1 are a risk factor for antibody-mediated kidney disease
We identify an intronic deletion in VANGL1 that predisposes to renal injury in high risk populations through a kidney-intrinsic process. Half of all SLE patients develop nephritis, yet the predisposing mechanisms to kidney damage remain poorly understood. There is limited evidence of genetic contribution to specific organ involvement in SLE.(1,2) We identify a large deletion in intron 7 of Van Gogh Like 1 (VANGL1), which associates with nephritis in SLE patients. The same deletion occurs at increased frequency in an indigenous population (Tiwi Islanders) with 10-fold higher rates of kidney disease compared with non-indigenous populations. Vangl1 hemizygosity in mice results in spontaneous IgA and IgG deposition within the glomerular mesangium in the absence of autoimmune nephritis. Serum transfer into B cell-deficient Vangl1(+/-) mice results in mesangial IgG deposition indicating that Ig deposits occur in a kidney-intrinsic fashion in the absence of Vangl1. These results suggest that Vangl1 acts in the kidney to prevent Ig deposits and its deficiency may trigger nephritis in individuals with SLE
Pcl-PRC2 is needed to generate high levels of H3-K27 trimethylation at Polycomb target genes
PRC2 is thought to be the histone methyltransferase (HMTase) responsible for H3-K27 trimethylation at Polycomb target genes. Here we report the biochemical purification and characterization of a distinct form of Drosophila PRC2 that contains the Polycomb group protein polycomblike (Pcl). Like PRC2, Pcl-PRC2 is an H3-K27-specific HMTase that mono-, di- and trimethylates H3-K27 in nucleosomes in vitro. Analysis of Drosophila mutants that lack Pcl unexpectedly reveals that Pcl-PRC2 is required to generate high levels of H3-K27 trimethylation at Polycomb target genes but is dispensable for the genome-wide H3-K27 mono- and dimethylation that is generated by PRC2. In Pcl mutants, Polycomb target genes become derepressed even though H3-K27 trimethylation at these genes is only reduced and not abolished, and even though targeting of the Polycomb protein complexes PhoRC and PRC1 to Polycomb response elements is not affected. Pcl-PRC2 is thus the HMTase that generates the high levels of H3-K27 trimethylation in Polycomb target genes that are needed to maintain a Polycomb-repressed chromatin state
6-Sulphated Chondroitins Have a Positive Influence on Axonal Regeneration
Chondroitin sulphate proteoglycans (CSPGs) upregulated in the glial scar inhibit axon regeneration via their sulphated glycosaminoglycans (GAGs). Chondroitin 6-sulphotransferase-1 (C6ST-1) is upregulated after injury leading to an increase in 6-sulphated GAG. In this study, we ask if this increase in 6-sulphated GAG is responsible for the increased inhibition within the glial scar, or whether it represents a partial reversion to the permissive embryonic state dominated by 6-sulphated glycosaminoglycans (GAGs). Using C6ST-1 knockout mice (KO), we studied post-injury changes in chondroitin sulphotransferase (CSST) expression and the effect of chondroitin 6-sulphates on both central and peripheral axon regeneration. After CNS injury, wild-type animals (WT) showed an increase in mRNA for C6ST-1, C6ST-2 and C4ST-1, but KO did not upregulate any CSSTs. After PNS injury, while WT upregulated C6ST-1, KO showed an upregulation of C6ST-2. We examined regeneration of nigrostriatal axons, which demonstrate mild spontaneous axon regeneration in the WT. KO showed many fewer regenerating axons and more axonal retraction than WT. However, in the PNS, repair of the median and ulnar nerves led to similar and normal levels of axon regeneration in both WT and KO. Functional tests on plasticity after the repair also showed no evidence of enhanced plasticity in the KO. Our results suggest that the upregulation of 6-sulphated GAG after injury makes the extracellular matrix more permissive for axon regeneration, and that the balance of different CSs in the microenvironment around the lesion site is an important factor in determining the outcome of nervous system injury
Frequency and syndrome specificity of antibodies to aquaporin-4 in neurological patients with rheumatic disorders
BACKGROUND: A new autoantibody (termed NMO-IgG, or AQP4-Ab) has recently been described in patients with neuromyelitis optica (NMO) and its formes frustes, longitudinally extensive transverse myelitis (LETM) and recurrent optic neuritis (rON). However, AQP4-Ab has been found also in patients with co-existing rheumatic diseases such as systemic lupus erythematosus (SLE) or Sjogren's syndrome (SS), conditions which are characterized by broad, polyspecific B cell activation. OBJECTIVES: In this study, we aimed at evaluating the syndrome specificity and frequency of AQP4-Ab in patients with rheumatic diseases and neurological symptoms. METHODS: For this purpose, serum samples from 109 neurological patients with established connective tissue disorders (CTD) (n = 54), possible CTD (n = 42), or vasculitis (n = 13) were analysed for the presence of AQP4-Ab by a cell-based assay employing recombinant human AQP4. RESULTS: AQP4-Ab was detectable in 31/40 (78%) patients with CTD and NMO spectrum disorders (median titre, 1:1000) but in none of the samples obtained from patients with CTD or vasculitis and neurological disorders other than NMO, LETM, or rON (n = 69). CONCLUSION: The high syndrome specificity of the antibody for neuromyelitis optica spectrum disorders (NMOSDs) in patients with CTD supports the concept of AQP4-Ab being involved in the pathogenesis of these neurological conditions, and argues against AQP4-Ab simply being part of the polyclonal B cell activation generally associated with rheumatic diseases. Moreover, the finding that AQP4-Ab is present in patients with CTD and co-existing NMOSD with approximately the same frequency as in patients without CTD strengthens the case of CTD and AQP4-Ab positive NMOSD representing two co-existing yet distinct entities in the majority of patients
Transit timings variations in the three-planet system: TOI-270
We present ground- and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered by TESS around a bright (K-mag = 8.25) M3V dwarf. The planets orbit near low-order mean-motion resonances (5:3 and 2:1) and are thus expected to exhibit large transit timing variations (TTVs). Following an extensive observing campaign using eight different observatories between 2018 and 2020, we now report a clear detection of TTVs for planets c and d, with amplitudes of ∼10 min and a super-period of ∼3 yr, as well as significantly refined estimates of the radii and mean orbital periods of all three planets. Dynamical modelling of the TTVs alone puts strong constraints on the mass ratio of planets c and d and on their eccentricities. When incorporating recently published constraints from radial velocity observations, we obtain masses of Mb=1.48± 0.18, M⊕, Mc=6.20± 0.31, M⊕, and Md=4.20± 0.16, M⊕ for planets b, c, and d, respectively. We also detect small but significant eccentricities for all three planets: eb = 0.0167 ± 0.0084, ec = 0.0044 ± 0.0006, and ed = 0.0066 ± 0.0020. Our findings imply an Earth-like rocky composition for the inner planet, and Earth-like cores with an additional He/H2O atmosphere for the outer two. TOI-270 is now one of the best constrained systems of small transiting planets, and it remains an excellent target for atmospheric characterization
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