287 research outputs found
Anti-mannose binding lectin antibodies in patients with systemic lupus erythematosus
published_or_final_versio
Cloning of the Canine \u3cem\u3eABCA4\u3c/em\u3e Gene and Evaluation in Canine Cone-Rod Dystrophies and Progressive Retinal Atrophies
PURPOSE: To characterize a novel early onset canine retinal disease, and evaluate the ATP-binding cassette transporter gene ABCA4 as a potential candidate gene in this and other canine retinal degenerations.
METHODS: Retinal disease was characterized ophthalmoscopically and electroretinographically in two pit bull terrier dogs and their purpose-bred descendants. All 50 exons of the canine ABCA4 gene were amplified, cloned and sequenced from retinal mRNA of a normal, a carrier and an affected animal, and polymorphisms identified. The latter were used to search for association between ABCA4 and retinal disease both within the study pedigrees and in additional canine breeds segregating retinal degenerations.
RESULTS: The disease derived from either founder is distinguished by early, severe, and rapidly progressive loss of cone function accompanied by progressive rod loss that is only relatively slower. Cloning and comparative sequencing of ABCA4 identified six point mutations, none of which were obviously pathogenic. Crossbreeding studies revealed that the diseases in the two founders, although similar, are nonallelic. Pedigree analysis of segregating polymorphisms revealed dissociation between ABCA4 and both retinal phenotypes.
CONCLUSIONS: The early, severe cone dysfunction in these diseases distinguish them from other forms of canine Progressive Retinal Atrophy. The development of a research population segregating these diseases presents two large animal models for the heterogenous human diseases termed cone-rod dystrophies. Analysis of the canine ABCA4 homolog gene documented its sequence and identified a set of point mutations that were used to exclude this gene as causal to these canine cone-rod dystrophies
The Caenorhabditis elegans nonmuscle myosin genes nmy-1 and nmy-2 function as redundant components of the let-502/Rho-binding kinase and mel-11/myosin phosphatase pathway during embryonic morphogenesis
Rho-binding kinase and the myosin phosphatase targeting subunit regulate nonmuscle contractile events in higher eukaryotes. Genetic evidence indicates that the C. elegans homologs regulate embryonic morphogenesis by controlling the actin-mediated epidermal cell shape changes that transform the spherical embryo into a long, thin worm. LET-502/Rho-binding kinase triggers elongation while MEL-11/myosin phosphatase targeting subunit inhibits this contractile event. We describe mutations in the nonmuscle myosin heavy chain gene nmy-1 that were isolated as suppressors of the mel-11 hypercontraction phenotype. However, a nmy-1 null allele displays elongation defects less severe than mutations in let-502 or in the single nonmuscle myosin light chain gene mlc-4. This results because nmy-1 is partially redundant with another nonmuscle myosin heavy chain, nmy-2, which was previously known only for its role in anterior/posterior polarity and cytokinesis in the early embryo. At the onset of elongation, NMY-1 forms filamentous-like structures similar to actin, and LET-502 is interspersed with these structures, where it may trigger contraction. MEL-11, which inhibits elongation, is initially cytoplasmic. In response to LET-502 activity, MEL-11 becomes sequestered away from the contractile apparatus, to the plasma membrane, when elongation commences. Upon completion of morphogenesis, MEL-11 again appears in the cytoplasm where it may halt actin/myosin contraction
The Reliability of Parafoveal Cone Density Measurements
Background Adaptive optics scanning light ophthalmoscopy (AOSLO) enables direct visualisation of the cone mosaic, with metrics such as cone density and cell spacing used to assess the integrity or health of the mosaic. Here we examined the interobserver and inter-instrument reliability of cone density measurements.
Methods For the interobserver reliability study, 30 subjects with no vision-limiting pathology were imaged. Three image sequences were acquired at a single parafoveal location and aligned to ensure that the three images were from the same retinal location. Ten observers used a semiautomated algorithm to identify the cones in each image, and this was repeated three times for each image. To assess inter-instrument reliability, 20 subjects were imaged at eight parafoveal locations on one AOSLO, followed by the same set of locations on the second AOSLO. A single observer manually aligned the pairs of images and used the semiautomated algorithm to identify the cones in each image.
Results Based on a factorial study design model and a variance components model, the interobserver study\u27s largest contribution to variability was the subject (95.72%) while the observer\u27s contribution was only 1.03%. For the inter-instrument study, an average cone density intraclass correlation coefficient (ICC) of between 0.931 and 0.975 was calculated.
Conclusions With the AOSLOs used here, reliable cone density measurements can be obtained between observers and between instruments. Additional work is needed to determine how these results vary with differences in image quality
Healthy Penis: San Francisco's Social Marketing Campaign to Increase Syphilis Testing among Gay and Bisexual Men
The authors describe the development, implementation, and evaluation of their innovative social marketing campaign
The opioid epidemic in rural northern New England: An approach to epidemiologic, policy, and legal surveillance
The opioid crisis presents substantial challenges to public health in New England\u27s rural states, where access to pharmacotherapy for opioid use disorder (OUD), harm reduction, HIV and hepatitis C virus (HCV) services vary widely. We present an approach to characterizing the epidemiology, policy and resource environment for OUD and its consequences, with a focus on eleven rural counties in Massachusetts, New Hampshire and Vermont between 2014 and 2018. We developed health policy summaries and logic models to facilitate comparison of opioid epidemic-related polices across the three states that could influence the risk environment and access to services. We assessed sociodemographic factors, rates of overdose and infectious complications tied to OUD, and drive-time access to prevention and treatment resources. We developed GIS maps and conducted spatial analyses to assess the opioid crisis landscape. Through collaborative research, we assessed the potential impact of available resources to address the opioid crisis in rural New England. Vermont\u27s comprehensive set of policies and practices for drug treatment and harm reduction appeared to be associated with the lowest fatal overdose rates. Franklin County, Massachusetts had good access to naloxone, drug treatment and SSPs, but relatively high overdose and HIV rates. New Hampshire had high proportions of uninsured community members, the highest overdose rates, no HCV surveillance data, and no local access to SSPs. This combination of factors appeared to place PWID in rural New Hampshire at elevated risk. Study results facilitated the development of vulnerability indicators, identification of locales for subsequent data collection, and public health interventions
Venezuelan Equine Encephalitis Virus Capsid Implicated in Infection-Induced Cell Cycle Delay in vitro
Venezuelan equine encephalitis virus (VEEV) is a positive sense, single-stranded RNA virus and member of the New World alphaviruses. It causes a biphasic febrile illness that can be accompanied by central nervous system involvement and moderate morbidity in humans and severe mortality in equines. The virus has a history of weaponization, lacks FDA-approved therapeutics and vaccines in humans, and is considered a select agent. Like other RNA viruses, VEEV replicates in the cytoplasm of infected cells and eventually induces apoptosis. The capsid protein, which contains a nuclear localization and a nuclear export sequence, induces a shutdown of host transcription and nucleocytoplasmic trafficking. Here we show that infection with VEEV causes a dysregulation of cell cycling and a delay in the G0/G1 phase in Vero cells and U87MG astrocytes. Cells infected with VEEV encoding a capsid NLS mutant or treated with the capsid-importin α interaction inhibitor G281-1485 were partially rescued from this cell cycle dysregulation. Pathway analysis of previously published RNA-sequencing data from VEEV infected U87MG astrocytes identified alterations of canonical pathways involving cell cycle, checkpoint regulation, and proliferation. Multiple cyclins including cyclin D1, cyclin A2 and cyclin E2 and other regulators of the cell cycle were downregulated in infected cells in a capsid NLS dependent manner. Loss of Rb phosphorylation, which is a substrate for cyclin/cdk complexes was also observed. These data demonstrate the importance of capsid nuclear localization and/or importin α binding for inducing cell cycle arrest and transcriptional downregulation of key cell cycle regulators
Long-Term Results from an Epiretinal Prosthesis to Restore Sight to the Blind
PurposeRetinitis pigmentosa (RP) is a group of inherited retinal degenerations leading to blindness due to photoreceptor loss. Retinitis pigmentosa is a rare disease, affecting only approximately 100 000 people in the United States. There is no cure and no approved medical therapy to slow or reverse RP. The purpose of this clinical trial was to evaluate the safety, reliability, and benefit of the Argus II Retinal Prosthesis System (Second Sight Medical Products, Inc, Sylmar, CA) in restoring some visual function to subjects completely blind from RP. We report clinical trial results at 1 and 3 years after implantation.DesignThe study is a multicenter, single-arm, prospective clinical trial.ParticipantsThere were 30 subjects in 10 centers in the United States and Europe. Subjects served as their own controls, that is, implanted eye versus fellow eye, and system on versus system off (native residual vision).MethodsThe Argus II System was implanted on and in a single eye (typically the worse-seeing eye) of blind subjects. Subjects wore glasses mounted with a small camera and a video processor that converted images into stimulation patterns sent to the electrode array on the retina.Main Outcome MeasuresThe primary outcome measures were safety (the number, seriousness, and relatedness of adverse events) and visual function, as measured by 3 computer-based, objective tests.ResultsA total of 29 of 30 subjects had functioning Argus II Systems implants 3 years after implantation. Eleven subjects experienced a total of 23 serious device- or surgery-related adverse events. All were treated with standard ophthalmic care. As a group, subjects performed significantly better with the system on than off on all visual function tests and functional vision assessments.ConclusionsThe 3-year results of the Argus II trial support the long-term safety profile and benefit of the Argus II System for patients blind from RP. Earlier results from this trial were used to gain approval of the Argus II by the Food and Drug Administration and a CE mark in Europe. The Argus II System is the first and only retinal implant to have both approvals
- …