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Biomedical subjects

William Sanchez

Publications and source records attributed to William Sanchez.

10 recordsLinked to original sources
PubMed2006

caGrid: design and implementation of the core architecture of the cancer biomedical informatics grid.

MOTIVATION: The complexity of cancer is prompting researchers to find new ways to synthesize information from diverse data sources and to carry out coordinated research efforts that span multiple institutions. There is a need for standard applications, common data models, and software infrastructure to enable more efficient access to and sharing of distributed computational resources in cancer research. To address this need the National Cancer Institute (NCI) has initiated a national-scale effort, called the cancer Biomedical Informatics Grid (caBIGtrade mark), to develop a federation of interoperable research information systems. RESULTS: At the heart of the caBIG approach to federated interoperability effort is a Grid middleware infrastructure, called caGrid. In this paper we describe the caGrid framework and its current implementation, caGrid version 0.5. caGrid is a model-driven and service-oriented architecture that synthesizes and extends a number of technologies to provide a standardized framework for the advertising, discovery, and invocation of data and analytical resources. We expect caGrid to greatly facilitate the launch and ongoing management of coordinated cancer research studies involving multiple institutions, to provide the ability to manage and securely share information and analytic resources, and to spur a new generation of research applications that empower researchers to take a more integrative, trans-domain approach to data mining and analysis. AVAILABILITY: The caGrid version 0.5 release can be downloaded from https://cabig.nci.nih.gov/workspaces/Architecture/caGrid/. The operational test bed Grid can be accessed through the client included in the release, or through the caGrid-browser web application http://cagrid-browser.nci.nih.gov.

Biomarkers, Tumor↗
PubMed2006

Palliative care for patients with end-stage liver disease ineligible for liver transplantation.

The proportion of patients with ESLD who will be managed without liver transplantation will increase in the near future, largely as a result of the increasing age of the population. Patients with ESLD are subject to many physical and psychosocial symptoms that negatively affect health-related quality of life. Sleep quality should be maximized by controlling pruritus and leg cramps. Many frequently used therapies are not supported by a strong evidence base. Advance directives should be addressed with all patients with ESLD, preferably in the outpatient setting before an acute deterioration. Medicare provides a hospice benefit for patients with ESLD, and referral to a hospice is appropriate for patients with an expected survival of 6 months or less.

Humans↗
PubMed2006

Severe hepatotoxicity associated with use of a dietary supplement containing usnic acid.

Dietary supplements containing usnic acid are marketed for weight loss and have been associated with hepatotoxicity. The specific ingredient responsible for the hepatotoxicity is currently unknown. We describe 2 patients who developed severe hepatotoxicity within 3 months of taking a dietary supplement containing usnic acid. One patient developed fulminant hepatic failure requiring emergency liver transplantation; the other developed submassive hepatic necrosis but did not require transplantation. Thorough investigation, including histopathological examination of the liver, revealed no other cause of acute liver injury. Usnic acid hepatotoxicity should be considered as a possible etiologic factor in patients presenting with fulminant hepatic failure, especially if they have been taking dietary supplements for weight reduction.

Adult↗
PubMed2004

Evaluation of polyp detection in relation to procedure time of screening or surveillance colonoscopy.

BACKGROUND AND OBJECTIVES: Multiple factors influence the yield of colonoscopy for the detection of neoplasia. Few studies have addressed the impact of colonoscopy duration on procedure yield. The aim of our study was to determine whether endoscopist-specific procedure times correlate with the number and clinical significance of polyps detected at screening or surveillance colonoscopy. METHODS: Procedural data from screening or surveillance colonoscopies performed at Mayo Clinic, Rochester MN, between January 1, 1996 and June 30, 2000, were reviewed. Individual endoscopists were characterized by their personal endoscopist procedure mean time (EPMT) to perform a negative colonoscopy. Procedure time included patient's consent and sedation. EPMT was then correlated with individual polyp detection rates. RESULTS: Overall, 10,159 colonoscopies were reviewed of which 4,312 (42.4%) yielded polyps. Polyp detection varied among endoscopists between 19.0% and 62.3%. There was a close correlation between EPMT and polyp yield (all sizes), r = 0.64, although correlation was weaker for polyps >10 mm (r = 0.42) and polyps >20 mm (r = 0.20). On multivariate analysis, longer mean endoscopist time was associated with colonic lesion detection, OR = 1.54 (95% CI 1.37-1.62). Longer mean procedure duration demonstrated a looser association with identification of polyps >10 mm, OR = 1.40 (1.19-1.64) and polyps >20 mm, OR = 1.03 (0.74-1.43). CONCLUSIONS: There is a direct correlation between colonoscopy procedure time and yield, with a three-fold variation of polyp detection rates. These results should prompt future prospective studies assessing the impact of colonoscopic withdrawal time on lesion detection.

Colonoscopy↗
PubMed2003

Spinal cord injury computer-assisted instruction for medical students.

OBJECTIVE: To determine if a computer-assisted instruction program would improve fourth-year medical students' knowledge base related to spinal cord injury, as determined by pretest and posttest scores. DESIGN: A multimedia computer-assisted instruction program was developed and offered on a volunteer basis to an entire class of fourth-year medical students (n = 168). Effectiveness of the instructional content was evaluated with pretests and posttests, and overall user satisfaction with the module was assessed with the courseware evaluation. RESULTS: The responses yielded 83 sets of completed pretest and posttest pairs and 80 sets of fully completed courseware evaluations. Mean posttest score was significantly higher than the mean pretest score (pretest, 6.65 +/- 1.44, vs. posttest, 7.36 +/- 1.38; df = 82, t = -4.74, P < 0.001). Courseware evaluations yielded positive ratings in all areas, including applicability and usability. CONCLUSIONS: The significantly increased posttest scores suggest that the students left the program with an expanded knowledge base in the content areas of spinal cord injury medicine covered in the computer-assisted instruction program.

Clinical Competence↗