211 research outputs found
A Randomized Comparison of Alternative Formats for Clinical Simulations
Computer-based clinical simulations for medical education vary widely in structure and for mat, yet few studies have examined which formats are optimal for particular educational settings. This study is a randomized comparison of the same simulated case in three formats: a "pedagogic" format offering explicit educational support, a "high-fidelity" format attempting to model clinical reasoning in the real world, and a "problem-solving" format that requires students to express specific diagnostic hypotheses Data were collected from rising third- year medical students using a posttest, attitudinal questionnaire, students' writeups of the case, and log files of students' progress through the simulation. Student performances on all measures differed significantly by format. In general, students using the pedagogic format were more proficient but less efficient. They acquired more information but were able to do proportionately less with it. The results suggest that the format of computer-based simulations is an important educational variable. Key words. medical education, undergraduate; clinical reasoning; computer-assisted instruction. (Med Decis Making 1991;11:265-272
Diabetes eye screening in urban settings serving minority populations: detection of diabetic retinopathy and other ocular findings using telemedicine.
IMPORTANCE: The use of a nonmydriatic camera for retinal imaging combined with the remote evaluation of images at a telemedicine reading center has been advanced as a strategy for diabetic retinopathy (DR) screening, particularly among patients with diabetes mellitus from ethnic/racial minority populations with low utilization of eye care.
OBJECTIVE: To examine the rate and types of DR identified through a telemedicine screening program using a nonmydriatic camera, as well as the rate of other ocular findings.
DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study (Innovative Network for Sight [INSIGHT]) was conducted at 4 urban clinic or pharmacy settings in the United States serving predominantly ethnic/racial minority and uninsured persons with diabetes. Participants included persons aged 18 years or older who had type 1 or 2 diabetes mellitus and presented to the community-based settings.
MAIN OUTCOMES AND MEASURES: The percentage of DR detection, including type of DR, and the percentage of detection of other ocular findings.
RESULTS: A total of 1894 persons participated in the INSIGHT screening program across sites, with 21.7% having DR in at least 1 eye. The most common type of DR was background DR, which was present in 94.1% of all participants with DR. Almost half (44.2%) of the sample screened had ocular findings other than DR; 30.7% of the other ocular findings were cataract.
CONCLUSIONS AND RELEVANCE: In a DR telemedicine screening program in urban clinic or pharmacy settings in the United States serving predominantly ethnic/racial minority populations, DR was identified on screening in approximately 1 in 5 persons with diabetes. The vast majority of DR was background, indicating high public health potential for intervention in the earliest phases of DR when treatment can prevent vision loss. Other ocular conditions were detected at a high rate, a collateral benefit of DR screening programs that may be underappreciated
The first long-lived mutants: discovery of the insulin/IGF-1 pathway for ageing
Inhibiting insulin/IGF-1 signalling extends lifespan and delays age-related disease in species throughout the animal kingdom. This life-extension pathway, the first to be defined, was discovered through genetic studies in the small roundworm Caenorhabditis elegans. This discovery is described here
Genomic alterations indicate tumor origin and varied metastatic potential of disseminated cells from prostate-cancer patients
Disseminated epithelial cells can be isolated from the bone marrow of a far greater fraction
of prostate-cancer patients than the fraction of patients who progress to metastatic disease.
To provide a better understanding of these cells, we have characterized their genomic alterations.
We first present an array comparative genomic hybridization method capable of detecting
genomic changes in the small number of disseminated cells (10-20) that can typically be obtained
from bone-marrow aspirates of prostate-cancer patients. We show multiple regions of
copy-number change, including alterations common in prostate cancer, such as 8p loss, 8q gain,
and gain encompassing the androgen-receptor gene on Xq, in the disseminated cell pools from
11 metastatic patients. We found fewer and less striking genomic alterations in the 48 pools of
disseminated cells from patients with organ-confined disease. However, we identify changes
shared by these samples with their corresponding primary tumors and prostate-cancer alterations
reported in the literature, evidence that these cells, like those in advanced disease, are
disseminated tumor cells (DTCs). We also demonstrate that DTCs from patients with advanced
and localized disease share several abnormalities, including losses containing cell-adhesion
genes and alterations reported to associate with progressive disease. These shared alterations
might confer the capability to disseminate or establish secondary disease. Overall, the spectrum
of genomic deviations is evidence for metastatic capacity in advanced-disease DTCs and variation
in that capacity in DTCs from localized disease. Our analysis lays the foundation for elucidation
of the relationship between DTC genomic alterations and progressive prostate cancer
Infrastructural Speculations: Tactics for Designing and Interrogating Lifeworlds
This paper introduces “infrastructural speculations,” an orientation toward speculative design that considers the complex and long-lived relationships of technologies with broader systems, beyond moments of immediate invention and design. As modes of speculation are increasingly used to interrogate questions of broad societal concern, it is pertinent to develop an orientation that foregrounds the “lifeworld” of artifacts—the social, perceptual, and political environment in which they exist. While speculative designs often imply a lifeworld, infrastructural speculations place lifeworlds at the center of design concern, calling attention to the cultural, regulatory, environmental, and repair conditions that enable and surround particular future visions. By articulating connections and affinities between speculative design and infrastructure studies research, we contribute a set of design tactics for producing infrastructural speculations. These tactics help design researchers interrogate the complex and ongoing entanglements among technologies, institutions, practices, and systems of power when gauging the stakes of alternate lifeworlds
Pharmacogenetic Discovery in CALGB (Alliance) 90401 and Mechanistic Validation of a VAC14 Polymorphism That Increases Risk of Docetaxel-Induced Neuropathy
Purpose Discovery of single nucleotide polymorphisms (SNPs) that predict a patient\u27s risk of docetaxel-induced neuropathy would enable treatment individualization to maximize efficacy and avoid unnecessary toxicity. The objectives of this analysis were to discover SNPs associated with docetaxel-induced neuropathy and mechanistically validate these associations in preclinical models of drug-induced neuropathy. Experimental Design A genome-wide association study was conducted in metastatic castrate-resistant prostate cancer patients treated with docetaxel, prednisone and randomized to bevacizumab or placebo on CALGB 90401. SNPs were genotyped on the Illumina HumanHap610-Quad platform followed by rigorous quality control. The inference was conducted on the cumulative dose at occurrence of grade 3+ sensory neuropathy using a cause-specific hazard model that accounted for early treatment discontinuation. Genes with SNPs significantly associated with neuropathy were knocked down in cellular and mouse models of drug-induced neuropathy. Results 498,081 SNPs were analyzed in 623 Caucasian patients, 50 (8%) of whom experienced grade 3+ neuropathy. The 1000 SNPs most associated with neuropathy clustered in relevant pathways including neuropathic pain and axonal guidance. A SNP in VAC14 (rs875858) surpassed genome-wide significance (p=2.12×10-8 adjusted p=5.88×10-7). siRNA knockdown of VAC14 in stem cell derived peripheral neuronal cells increased docetaxel sensitivity as measured by decreased neurite processes (p=0.0015) and branches (p\u3c0.0001). Prior to docetaxel treatment VAC14 heterozygous mice had greater nociceptive sensitivity than wild-type litter mate controls (p=0.001). Conclusions VAC14 should be prioritized for further validation of its potential role as a predictor of docetaxel-induced neuropathy and biomarker for treatment individualization
Enabling long-term oceanographic research : changing data practices, information management strategies and informatics
Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 55 (2008): 2132-2142, doi:10.1016/j.dsr2.2008.05.009.Interdisciplinary global ocean science requires new ways of thinking about data and data
management. With new data policies and growing technological capabilities, datasets of
increasing variety and complexity are being made available digitally and data management is
coming to be recognized as an integral part of scientific research. To meet the changing
expectations of scientists collecting data and of data reuse by others, collaborative strategies
involving diverse teams of information professionals are developing. These changes are
stimulating the growth of information infrastructures that support multi-scale sampling, data
repositories, and data integration. Two examples of oceanographic projects incorporating data
management in partnership with science programs are discussed: the Palmer Station Long-Term
Ecological Research program (Palmer LTER) and the United States Joint Global Ocean Flux
Study (US JGOFS). Lessons learned from a decade of data management within these
communities provide an experience base from which to develop information management
strategies – short-term and long-term. Ocean Informatics provides one example of a conceptual
framework for managing the complexities inherent to sharing oceanographic data. Elements are
introduced that address the economies-of-scale and the complexities-of-scale pertinent to a
broader vision of information management and scientific research.Support is provided by NSF OPP-0217282, OCE-0405069, HSD-0433369 and Scripps
Institution of Oceanography (K.S.Baker) and by NSF OCE-8814310, OCE-0097291, OCE-
0510046 and OCE-0646353 (C.Chandler)
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Motor phenotype of LRRK2 G2019S carriers in early-onset Parkinson disease
Objective: To determine the motor phenotype of LRRK2 G2019S mutation carriers. LRRK2 mutation carriers were previously reported to manifest the tremor dominant motor phenotype, which has been associated with slower motor progression and less cognitive impairment compared with the postural instability and gait difficulty (PIGD) phenotype. Design: Cross-sectional observational study. Setting: Thirteen movement disorders centers. Participants: Nine hundred twenty-five early-onset Parkinson disease cases defined as age at onset younger than 51 years. Main Outcome Measures: LRRK2 mutation status and Parkinson disease motor phenotype: tremor dominant or PIGD. Demographic information, family history of Parkinson disease, and the Unified Parkinson's Disease Rating Scale score were collected on all participants. DNA samples were genotyped for LRRK2 mutations (G2019S, I2020T, R1441C, and Y1699C). Logistic regression was used to examine associations of G2019S mutation status with motor phenotype adjusting for disease duration, Ashkenazi Jewish ancestry, levodopa dose, and family history of Parkinson disease. Results: Thirty-four cases (3.7%) (14 previously reported) were G2019S carriers. No other mutations were found. Carriers were more likely to be Ashkenazi Jewish (55.9% vs 11.9%; P < .001) but did not significantly differ in any other demographic or disease characteristics. Carriers had a lower tremor score (P = .03) and were more likely to have a PIGD phenotype (92.3% vs 58.9%; P = .003). The association of the G2019S mutation with PIGD phenotype remained after controlling for disease duration and Ashkenazi Jewish ancestry (odds ratio, 17.7; P < .001). Conclusion: Early-onset Parkinson disease G2019S LRRK2 carriers are more likely to manifest the PIGD phenotype, which may have implications for disease course
The Sorcerer II Global Ocean Sampling Expedition: Northwest Atlantic through Eastern Tropical Pacific
The world's oceans contain a complex mixture of micro-organisms that are for the most part, uncharacterized both genetically and biochemically. We report here a metagenomic study of the marine planktonic microbiota in which surface (mostly marine) water samples were analyzed as part of the Sorcerer II Global Ocean Sampling expedition. These samples, collected across a several-thousand km transect from the North Atlantic through the Panama Canal and ending in the South Pacific yielded an extensive dataset consisting of 7.7 million sequencing reads (6.3 billion bp). Though a few major microbial clades dominate the planktonic marine niche, the dataset contains great diversity with 85% of the assembled sequence and 57% of the unassembled data being unique at a 98% sequence identity cutoff. Using the metadata associated with each sample and sequencing library, we developed new comparative genomic and assembly methods. One comparative genomic method, termed “fragment recruitment,” addressed questions of genome structure, evolution, and taxonomic or phylogenetic diversity, as well as the biochemical diversity of genes and gene families. A second method, termed “extreme assembly,” made possible the assembly and reconstruction of large segments of abundant but clearly nonclonal organisms. Within all abundant populations analyzed, we found extensive intra-ribotype diversity in several forms: (1) extensive sequence variation within orthologous regions throughout a given genome; despite coverage of individual ribotypes approaching 500-fold, most individual sequencing reads are unique; (2) numerous changes in gene content some with direct adaptive implications; and (3) hypervariable genomic islands that are too variable to assemble. The intra-ribotype diversity is organized into genetically isolated populations that have overlapping but independent distributions, implying distinct environmental preference. We present novel methods for measuring the genomic similarity between metagenomic samples and show how they may be grouped into several community types. Specific functional adaptations can be identified both within individual ribotypes and across the entire community, including proteorhodopsin spectral tuning and the presence or absence of the phosphate-binding gene PstS
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