931 research outputs found
Strabismus as a Presenting Sign in Retinoblastoma
PURPOSE:To report the presenting signs of retinoblastoma in a large cohort of patients who underwent orthoptic assessment at presentation.
METHODS:A retrospective medical chart review was conducted on 131 patients with retinoblastoma who presented consecutively to a single institution during a 6-year period. The main outcome measure was the presenting sign(s) of the disease.
RESULTS:Of 131 patients with retinoblastoma, 88 presented with unilateral disease and 43 presented with bilateral disease (mean ages: 22.7 and 14.8 months, respectively). Leukocoria was the presenting sign in 56% of patients, leukocoria and strabismus in 18%, strabismus in 13%, inflammation in 8%, and âotherâ signs in 5%. The fovea was affected by the retinoblastoma tumor or its sequelae in 75% of patients. Patients who presented with strabismus were significantly more likely to have foveal involvement than patients who presented with leukocoria alone (P = .001). Thirty-one percent of patients had strabismus as a component of their presentation; 63% had exotropia, 23% had esotropia, and 14% had variable strabismus. The percentage of patients with strabismus increased to 66% when small angle and variable strabismus were also considered. Patients with inflammation had worse ocular survival (P < .05).
CONCLUSIONS:This study assessed the combination of leukocoria and strabismus as presenting features of retinoblastoma. Foveal involvement is common in patients who have strabismus and may influence decision-making regarding globe salvage. The authors confirmed that exotropia is more common than esotropia in retinoblastoma in the largest cohort to have undergone an orthoptic assessment
Quantitative Mass Spectrometry Evaluation of Human Retinol Binding Protein 4 and Related Variants
Background: Retinol Binding Protein 4 (RBP4) is an exciting new biomarker for the determination of insulin resistance and type 2 diabetes. It is known that circulating RBP4 resides in multiple variants which may provide enhanced clinical utility, but conventional immunoassay methods are blind to such differences. A Mass Spectrometric immunoassay (MSIA) technology that can quantitate total RBP4 as well as individual isoforms may provide an enhanced analysis for this biomarker. Methods: RBP4 was isolated and detected from 0.5 uL of human plasma using MSIA technology, for the simultaneous quantification and differentiation of endogenous human RBP4 and its variants. Results: The linear range of the assay was 7.81â500 ug/mL, and the limit of detection and limit of quantification were 3.36 ug/mL and 6.52 ug/mL, respectively. The intra-assay CVs were determined to be 5.1 % and the inter-assay CVs were 9.6%. The percent recovery of the RBP4-MSIA ranged from 95 â 105%. Method comparison of the RBP4 MSIA vs the Immun Diagnostik ELISA yielded a Passing & Bablok fit of MSIA = 1.056 ELISA â 3.09, while the Cusum linearity p-value was.0.1 and the mean bias determined by the Altman Bland test was 1.2%. Conclusion: The novel RBP4 MSIA provided a fast, accurate and precise quantitative protein measurement as compared to the standard commercially available ELISA. Moreover, this method also allowed for the detection of RBP4 variants that are present in each sample, which may in the future provide a new dimension in the clinical utility of this biomarker
Evaluating Small UAS Near Midair Collision Risk Using AeroScope and ADS-B
As small unmanned aircraft systems (sUAS) continue to proliferate in the National Airspace System (NAS), near midair collisions are becoming more common. In late 2017, the National Transportation Safety Board released a report detailing the first confirmed midair collision between a sUAS and manned aircraft in the United States. In February 2018, a video of a sUAS maneuvering around a passenger jetliner on approach to a Las Vegas airport went viral on YouTube. Just months later, a helicopter instructor pilot reported performing evasive maneuvers to avoid colliding with a sUAS, resulting in a non-fatal crash. From 2014 to 2018 the Federal Aviation Administration (FAA) recorded 6,117 reports of near encounters between manned and unmanned aircraft within the NAS (Government Accountability Office [GAO], 2018). In their report, the GAO (2018) highlighted the need for additional operational data to aid the FAAâs management of safety risks posed by unmanned aircraft. The purpose of this study was to evaluate aviation interference and safety hazards caused by unmanned aircraft at an airport in Class C airspace. Using a passive RF sUAS detection device known as the AeroScope, the authors collected sUAS operations data for 13 days at Daytona Beach International Airport in Florida. While the study was limited to DJI-manufactured sUAS, the results yielded detailed operational information on 190 sUAS flights that had been conducted during the sampling period. The authors identified several operator behaviors including preferred sUAS models, flight days and times, common operating locations, and operational altitudes. Operational data was compared against published FAA UAS Facility Maps (UASFM) to examine potential risk areas. Additionally, sUAS detections were compared against historical ADS-B information to examine for potential midair collisions, yielding several notable case studies. The authors evaluated the effectiveness of existing geofencing infrastructure and provided recommendations for integration with the Low Altitude Authorization and Notification Capability (LAANC) system. The paper culminates with a proposal for integrating LAANC usage data into existing aviation information sharing infrastructure to improve manned pilot situational awareness of sUAS activity within the NAS
Predictors of survival in frontotemporal lobar degeneration syndromes
After decades of research, large-scale clinical trials in patients diagnosed with frontotemporal lobar degeneration (FTLD) are now underway across multiple centres worldwide. As such, refining the determinants of survival in FTLD represents a timely and important challenge. Specifically, disease outcome measures need greater clarity of definition to enable accurate tracking of therapeutic interventions in both clinical and research settings. Multiple factors potentially determine survival, including the clinical phenotype at presentation; radiological patterns of atrophy including markers on both structural and functional imaging; metabolic factors including eating behaviour and lipid metabolism; biomarkers including both serum and cerebrospinal fluid markers of underlying pathology; as well as genetic factors, including both dominantly inherited genes, but also genetic modifiers. The present review synthesises the effect of these factors on disease survival across the syndromes of frontotemporal dementia, with comparison to amyotrophic lateral sclerosis, progressive supranuclear palsy and corticobasal syndrome. A pathway is presented that outlines the utility of these varied survival factors for future clinical trials and drug development. Given the complexity of the FTLD spectrum, it seems unlikely that any single factor may predict overall survival in individual patients, further suggesting that a precision medicine approach will need to be developed in predicting disease survival in FTLD, to enhance drug target development and future clinical trial methodologies
Structured evaluation of virtual environments for special-needs education
This paper describes the development of a structured approach to evaluate experiential and communication virtual learning environments (VLEs) designed specifically for use in the education of children with severe learning difficulties at the Shepherd special needs school in Nottingham, UK. Constructivist learning theory was used as a basis for the production of an evaluation framework, used to evaluate the design of three VLEs and how they were used by students with respect to this learning theory. From an observational field study of student-teacher pairs using the VLEs, 18 behaviour categories were identified as relevant to five of the seven constructivist principles defined by Jonassen (1994). Analysis of student-teacher behaviour was used to provide support for, or against, the constructivist principles. The results show that the three VLEs meet the constructivist principles in very different ways and recommendations for design modifications are put forward
Reframing e-assessment: building professional nursing and academic attributes in a first year nursing course
This paper documents the relationships between pedagogy and e-assessment in two nursing courses offered at the University of Southern Queensland, Australia. The courses are designed to build the academic, numeracy and technological attributes student nurses need if they are to succeed at university and in the nursing profession. The paper first outlines the management systems supporting the two courses and how they intersect with the e-learning and e-assessment components of course design. These pedagogical choices are then reviewed. While there are lessons to be learnt and improvements to be made, preliminary results suggest students and staff are extremely supportive of the courses. The e-assessment is very positively received with students reporting increased confidence and competency in numeracy, as well as IT, academic, research and communication skills
Dielectronic Recombination of Ground-State and Metastable Li+ Ions
Dielectronic recombination has been investigated for Delta-n = 1 resonances
of ground-state Li+(1s^2) and for Delta-n = 0 resonances of metastable Li+(1s2s
^3S). The ground-state spectrum shows three prominent transitions between 53
and 64 eV, while the metastable spectrum exhibits many transitions with
energies < 3.2 eV. Reasonably good agreement of R-matrix, LS coupling
calculations with the measured recombination rate coefficient is obtained. The
time dependence of the recombination rate yields a radiative lifetime of 52.2
+- 5.0 s for the 2 ^3S level of Li+.Comment: Submitted to Phys. Rev. A; REVTeX, 4 pages, 3 figure
Dose Effects of Oxaliplatin on Persistent and Transient Na+ Conductances and the Development of Neurotoxicity
BACKGROUND: Oxaliplatin, a platinum-based chemotherapy utilised in the treatment of colorectal cancer, produces two forms of neurotoxicity--acute sensorimotor neuropathic symptoms and a dose-limiting chronic sensory neuropathy. Given that a Na(+) channelopathy has been proposed as the mechanism underlying acute oxaliplatin-induced neuropathy, the present study aimed to determine specific mechanisms of Na(+) channel dysfunction. METHODOLOGY/PRINCIPAL FINDINGS: Specifically the function of transient and persistent Na(+) currents were followed during treatment and were investigated in relation to oxaliplatin dose level. Eighteen patients were assessed before and after a single oxaliplatin infusion with motor and sensory axonal excitability studies performed on the median nerve at the wrist. While refractoriness (associated with Na(+) channel inactivation) was significantly altered post-oxaliplatin infusion in both motor (Pre: 31.7±6.4%; Post: 68.8±14.5%; Pâ€.001) and sensory axons (Pre: 31.4±5.4%; Post: 21.4±5.5%; P<.05), strength-duration time constant (marker of persistent Na(+) conductances) was not significantly altered post-infusion (Motor Pre: 0.395±0.01 ms; Post: 0.394±0.02 ms; NS; Sensory Pre:0.544±0.03 ms; Post: 0.535±0.05 ms; NS). However, changes in strength-duration time constant were significantly correlated with changes in refractoriness in motor and sensory axons (Motor correlation coefficientâ=â-.65; P<.05; Sensory correlation coefficientâ=â.67; P<.05). CONCLUSIONS/SIGNIFICANCE: It is concluded that the predominant effect of acute oxaliplatin exposure in human motor and sensory axons is mediated through changes in transient rather than persistent Na(+) conductances. These findings are likely to have implications for the design and trial of neuroprotective strategies
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