Characterization of adjacent breast tumors using oligonucleotide microarrays

BACKGROUND: Current methodology often cannot distinguish second primary breast cancers from multifocal disease, a potentially important distinction for clinical management. In the present study we evaluated the use of oligonucleotide-based microarray analysis in determining the clonality of tumors by comparing gene expression profiles. METHOD: Total RNA was extracted from two tumors with no apparent physical connection that were located in the right breast of an 87-year-old woman diagnosed with invasive ductal carcinoma (IDC). The RNA was hybridized to the Affymetrix Human Genome U95A Gene Chip(®) (12,500 known human genes) and analyzed using the Gene Chip Analysis Suite(®) 3.3 (Affymetrix, Inc, Santa Clara, CA, USA) and JMPIN(®) 3.2.6 (SAS Institute, Inc, Cary, NC, USA). Gene expression profiles of tumors from five additional patients were compared in order to evaluate the heterogeneity in gene expression between tumors with similar clinical characteristics. RESULTS: The adjacent breast tumors had a pairwise correlation coefficient of 0.987, and were essentially indistinguishable by microarray analysis. Analysis of gene expression profiles from different individuals, however, generated a pairwise correlation coefficient of 0.710. CONCLUSION: Transcriptional profiling may be a useful diagnostic tool for determining tumor clonality and heterogeneity, and may ultimately impact on therapeutic decision making

The impact of open versus closed format ICU admission practices on the outcome of high risk surgical patients: a cohort analysis

<p>Abstract</p> <p>Background</p> <p>In the year 2000, the organizational structure of the ICU in the Zaandam Medical Centre (ZMC) changed from an open to a closed format ICU. The objective of this study was to evaluate the effect of this organizational change on outcome in high risk surgical patients.</p> <p>Methods</p> <p>The medical records of all consecutive high risk surgical patients admitted to the ICU from 1996 to 1998 (open format) and from 2003 to 2005 (closed format), were reviewed. High-risk patients were defined according to the Identification of Risk in Surgical patients (IRIS) score. Parameters studied were: mortality, morbidity, ICU length of stay (LOS) and hospital LOS.</p> <p>Results</p> <p>Mortality of ICU patients was 25.7% in the open format group and 15.8% in the closed format group (p = 0.01). Morbidity decreased from 48.6% to 46.1% (p = 0.6). The average length of hospital stay was 17 days in the open format group, and 21 days in the closed format group (p = 0.03).</p> <p>Conclusions</p> <p>High risk surgical patients in the ICU are patients that have undergone complex and often extensive surgery. These patients are in need of specialized treatment and careful monitoring for maximum safety and optimal care. Our results suggest that closed format is a more favourable setting than open format to minimize the effects of high risk surgery, and to warrant safe outcome in this patient group.</p

A review of longitudinal clinical programs in US medical schools

ABSTRACT Background:: Longitudinal clinical experiences are a common component of undergraduate medical curricula, yet these programs have not been systematically characterized in US medical schools. Objective:: Our study sought to identify and characterize longitudinal clinical programs (LCPs) in US medical schools and measure associations between programs’ structures and goals. Design:: Using a mixed-methods approach, we conducted a secondary analysis of data from publicly available websites. We conducted a systematic keyword search of the websites of 137 LCME-accredited US medical schools to identify LCPs. We included programs with student–patient interactions of at least six months. We categorized programs using qualitative thematic analysis and compared associations between program structures and goals. Results:: We identified 98 LCPs in 69 schools. Half (52.0%) of LCPs occurred during the core clinical year. Program structures included ‘clinic attachments’ (50.0%), ‘longitudinal integrated clerkships’ (26.5%), and ‘patient attachments’ (20.4%). We identified goals in 89 programs, including ‘exposing students to specific topics, patient demographics, or practice settings’ (78.7%); ‘clinical or professional skill development’ (65.2%); and ‘understanding the patient experience’ (19.1%). Patient attachments were associated with ‘exposure to specific patient demographics’ (P = .04) and ‘understanding the patient experience’ (P = .03). Pre-clinical programs were associated with clinical skills development (P = .01). Conclusions:: Our study identifies the scope and nature of LCPs in US medical schools. Understanding connections between educational structures and goals may guide program design and research investigations of educational processes and outcomes

1-Mb Resolution Array-Based Comparative Genomic Hybridization Using a BAC Clone Set Optimized for Cancer Gene Analysis

Array-based comparative genomic hybridization (aCGH) is a recently developed tool for genome-wide determination of DNA copy number alterations. This technology has tremendous potential for disease-gene discovery in cancer and developmental disorders as well as numerous other applications. However, widespread utilization of a CGH has been limited by the lack of well characterized, high-resolution clone sets optimized for consistent performance in aCGH assays and specifically designed analytic software. We have assembled a set of ∼4100 publicly available human bacterial artificial chromosome (BAC) clones evenly spaced at ∼1-Mb resolution across the genome, which includes direct coverage of ∼400 known cancer genes. This aCGH-optimized clone set was compiled from five existing sets, experimentally refined, and supplemented for higher resolution and enhancing mapping capabilities. This clone set is associated with a public online resource containing detailed clone mapping data, protocols for the construction and use of arrays, and a suite of analytical software tools designed specifically for aCGH analysis. These resources should greatly facilitate the use of aCGH in gene discovery