973 resultados para Gerald cohen
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Purpose. To evaluate the long-term graft survival in patients with flexible open-loop anterior chamber intraocular lenses (AC IOL). Methods. We retrospectively reviewed the records of patients with aphakic/pseudophakic bullous keratopathy who underwent penetrating keratoplasty and flexible open-loop AC IOL implantation in our institution from 1983 to 1988. Results. 79 eyes from 77 patients were included in the study. Mean follow-up was 50 months (range 1 to 123 months). At last follow-up 61 eyes (77.2%) had clear grafts. Among them, the visual acuity was = 20/40 in 14 eyes (23.0%), 20/50-20/100 in 22 eyes (36.1%), 20/200-20/400 in 9 eyes (14.8%) and = CF in 16 (26.2%). Increment of glaucoma medications and/or glaucoma surgery was the most frequent complication (37 eyes, 46,8%). Cystoid macular edema was newly diagnosed in 10 eyes (12.7%). Conclusions. Flexible, open-loop anterior chamber lens are a viable option in the treatment of patients with aphakic or pseudophakic bullous keratopathy undergoing penetrating keratoplasty.
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Purpose. To evaluate the long-term graft survival and complications of flexible, open-loop anterior-chamber intraocular lenses in patients with penetrating keratoplasty for pseudophakic or aphakic bullous keratopathy. Methods. We reviewed charts of all consecutive patients who underwent penetrating keratoplasty for pseudophakic or aphakic bullous keratopathy combined with implantation of a flexible, open-loop, anterior-chamber intraocular lens at our institution between 1983 and 1988. One-hundred one eyes of 99 patients were evaluated. Graft-survival rates were calculated by using the Kaplan-Meier actuarial method. Results. Mean follow-up was 49.8 months (range. 1-144). The probability of graft survival at 1, 2, 4, 6, and 8 years was 93, 87, 78, 65, and 65%, respectively. A total of 25 (24.8%) grafts failed. Progressive corneal edema without signs of rejection was the most common finding in patients with failed grafts (10 eyes, 40%). The most frequent complication observed was newly diagnosed or worsening of preexisting glaucoma (46 eyes, 45.5%). Conclusions. Our long-term results support flexible, open-loop anterior-chamber intraocular lenses as a reasonable option, at the time of penetrating keratoplasty, in patients with pseudophakic and aphakic bullous keratopathy.
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Purpose. To identify changing trends in indications for penetrating keratoplasty and associated surgical procedures. Methods. Review of charts from all patients who underwent penetrating keratoplasty at Wills Eye Hospital from January 1, 1989 through December 31, 1995. Results. A total of 2,442 corneal transplants were performed in 2,186 patients. The leading indication for penetrating keratoplasty was pseudophakic corneal edema, accounting for 634 cases (26.0%); 54.7% of them were associated with anterior chamber intraocular lenses, 36.4% with posterior chamber intraocular lenses, and 3.1% with iris-fixated intraocular lenses. Regraft (17.8%), Fuchs' dystrophy (15.7%), and keratoconus (13.2%) followed pseudophakic corneal edema in frequency. Cataract extraction, with or without intraocular lens implantation, was combined with penetrating keratoplasty in 439 cases of 1,264 phakic eyes (34.7%). Intraocular lens exchange was performed in 285 of the 634 cases of pseudophakic cornea edema (44.9%). Conclusion. Pseudophakic corneal edema was the leading indication for penetrating keratoplasty, with an increasing number of cases associated with posterior chamber intraocular lenses during the study period (p = 0.001). The number of regrafts steadily increased between 1989 and 1995 (p = 0.001), being the second most common indication for corneal transplantation since 1992.
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Purpose: The purpose of this study was to describe the outcome of patients with filtering blebs who were fit with contact lenses. Methods: We retrospectively studied patients with filtering blebs secondary to glaucoma or cataract surgery who were fit with contact lenses. Eight eyes from seven patients were identified. Results: Five patients (six eyes) were fit with gas permeable contact lenses and two patients (two eyes) were fit with soft contact lenses. Successful fits were achieved in all patients. No complications were observed after a mean follow-up of 64.6±28.5 months. Conclusions: No significant complications were recorded in our series of patients with filtering blebs who were fit with contact lenses. We think that when indications for fitting contact lenses are justified, patients with filtering blebs are acceptable candidates for contact lens use. However, adequate selection of cases, careful contact lens fitting, patient education, and close follow-up are necessary.
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Purpose: The purpose of this study was to evaluate the outcome of patients with healed moderate to severe contact lens-associated corneal infectious ulcers who were re-fit with contact lenses. Methods: We retrospectively studied patients who were fit with contact lenses on our service and who had had moderate to severe corneal infectious ulcers associated with previous contact lens use. Six patients were included in the study. Results: Gas permeable contact lenses were fit in five patients, and a soft contact lens was fit in one patient. Successful fit was achieved in all cases and visual acuities were equal to or better than 20/30 in all patients. No significant complications were observed after a mean follow-up of 23 months (range, 6-45 months). Conclusion: In this small series of patients with a history of moderate to severe contact-lens related infectious keratitis, no complications were observed after contact lenses were refit. Contact lens wear in patients with a history of infectious keratitis may be safe and useful in order to achieve visual rehabilitation.
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In recent years, gradient vector flow (GVF) based algorithms have been successfully used to segment a variety of 2-D and 3-D imagery. However, due to the compromise of internal and external energy forces within the resulting partial differential equations, these methods may lead to biased segmentation results. In this paper, we propose MSGVF, a mean shift based GVF segmentation algorithm that can successfully locate the correct borders. MSGVF is developed so that when the contour reaches equilibrium, the various forces resulting from the different energy terms are balanced. In addition, the smoothness constraint of image pixels is kept so that over- or under-segmentation can be reduced. Experimental results on publicly accessible datasets of dermoscopic and optic disc images demonstrate that the proposed method effectively detects the borders of the objects of interest.
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The inherent difficulty of thread-based shared-memory programming has recently motivated research in high-level, task-parallel programming models. Recent advances of Task-Parallel models add implicit synchronization, where the system automatically detects and satisfies data dependencies among spawned tasks. However, dynamic dependence analysis incurs significant runtime overheads, because the runtime must track task resources and use this information to schedule tasks while avoiding conflicts and races.
We present SCOOP, a compiler that effectively integrates static and dynamic analysis in code generation. SCOOP combines context-sensitive points-to, control-flow, escape, and effect analyses to remove redundant dependence checks at runtime. Our static analysis can work in combination with existing dynamic analyses and task-parallel runtimes that use annotations to specify tasks and their memory footprints. We use our static dependence analysis to detect non-conflicting tasks and an existing dynamic analysis to handle the remaining dependencies. We evaluate the resulting hybrid dependence analysis on a set of task-parallel programs.
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We present BDDT, a task-parallel runtime system that dynamically discovers and resolves dependencies among parallel tasks. BDDT allows the programmer to specify detailed task footprints on any memory address range, multidimensional array tile or dynamic region. BDDT uses a block-based dependence analysis with arbitrary granularity. The analysis is applicable to existing C programs without having to restructure object or array allocation, and provides flexibility in array layouts and tile dimensions.
We evaluate BDDT using a representative set of benchmarks, and we compare it to SMPSs (the equivalent runtime system in StarSs) and OpenMP. BDDT performs comparable to or better than SMPSs and is able to cope with task granularity as much as one order of magnitude finer than SMPSs. Compared to OpenMP, BDDT performs up to 3.9× better for benchmarks that benefit from dynamic dependence analysis. BDDT provides additional data annotations to bypass dependence analysis. Using these annotations, BDDT outperforms OpenMP also in benchmarks where dependence analysis does not discover additional parallelism, thanks to a more efficient implementation of the runtime system.
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In some randomized trials comparing revascularization strategies for patients with diabetes, coronary-artery bypass grafting (CABG) has had a better outcome than percutaneous coronary intervention (PCI). We sought to discover whether aggressive medical therapy and the use of drug-eluting stents could alter the revascularization approach for patients with diabetes and multivessel coronary artery disease.
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Objective: To determine the feasibility of a randomized controlled trial investigating the effectiveness of physiotherapy for sleep disturbance in chronic low back pain (CLBP) (=12wks). Design: Randomized controlled trial with evaluations at baseline, 3 months, and 6 months. Setting: Outpatient physiotherapy department in an academic teaching hospital. Participants: Participants with CLBP were randomly assigned to a walking program (n=20; mean age ± SD, 46.4±13.8y), supervised exercise class (n=20; mean age ± SD, 41.3±11.9y), or usual physiotherapy (n=20; mean age ± SD, 47.1±14.3y). The 3-month evaluation was completed by 44 participants (73%), and 42 (70%) participants completed the 6-month evaluation. Interventions: Participants received a physiotherapy-delivered 8-week walking program, an 8-week group supervised exercise class (1 class/wk), or 1-to-1 usual physiotherapy (advice, manual therapy, and exercise). Main Outcome Measures: Sleep was assessed by the self-reported Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Pittsburgh Sleep Diary, and objective actigraphy. Results: Groups were comparable at baseline. Most (95%, n=57) of the participants had sleep disturbance. The acceptability of actigraphy was excellent at baseline (58 of 60 participants), but dropped at 3 months (26 of 44 participants). There were improvements on the PSQI and ISI in all groups at 3 and 6 months, with predominantly medium effect sizes (Cohen d=0.2-0.5). Conclusions: The high prevalence of sleep disturbance indicated the feasibility of good recruitment in future trials. The PSQI would be a suitable screening tool and outcome measure alongside an objective nonobtrusive sleep outcome measure. The effectiveness of physiotherapy for sleep disturbance in CLBP warrants investigation in a fully powered randomized controlled trial. © 2013 American Congress of Rehabilitation Medicine.
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Reports of substantial evidence for genetic linkage of schizophrenia to chromosome 1q were evaluated by genotyping 16 DNA markers across 107 centimorgans of this chromosome in a multicenter sample of 779 informative schizophrenia pedigrees. No significant evidence was observed for such linkage, nor for heterogeneity in allele sharing among the eight individual samples. Separate analyses of European-origin families, recessive models of inheritance, and families with larger numbers of affected cases also failed to produce significant evidence for linkage. If schizophrenia susceptibility genes are present on chromosome 1q, their population-wide genetic effects are likely to be small.
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Schizophrenia is a common disorder with high heritability and a 10-fold increase in risk to siblings of probands. Replication has been inconsistent for reports of significant genetic linkage. To assess evidence for linkage across studies, rank-based genome scan meta-analysis (GSMA) was applied to data from 20 schizophrenia genome scans. Each marker for each scan was assigned to 1 of 120 30-cM bins, with the bins ranked by linkage scores (1 = most significant) and the ranks averaged across studies (R(avg)) and then weighted for sample size (N(sqrt)[affected casess]). A permutation test was used to compute the probability of observing, by chance, each bin's average rank (P(AvgRnk)) or of observing it for a bin with the same place (first, second, etc.) in the order of average ranks in each permutation (P(ord)). The GSMA produced significant genomewide evidence for linkage on chromosome 2q (PAvgRnk
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Immunosuppression is cornerstone treatment of antineutrophil cytoplasmic antibody associated vasculitis (AAV) but is later complicated by infection, cancer, cardiovascular and chronic kidney disease. Caveolin-1 is an essential structural protein for small cell membrane invaginations known as caveolae. Its functional role has been associated with these complications. For the first time, caveolin-1 (CAV1) gene variation is studied in AAV.