A comparison study reveals important features of agreement and disagreement between summarized DNA and RNA data obtained from renal cell carcinoma.

Cytogenetic abnormalities, such as DNA amplifications and deletions, often lead to significant changes in gene expression levels within a chromosomal region. Instead of generating additional DNA copy number data, one method to identify DNA copy number abnormalities has been to search existing gene expression data for regional perturbations in gene expression. However, it is not clear how well this surrogate method performs in the examination of individual tumors and how we can use both DNA and RNA data to identify candidate genes that may be mutated. Here we report a comparison study using summarized DNA and RNA data to identify chromosomal abnormalities in human samples. Forty-four tissue samples from patients diagnosed as having renal cell carcinoma (RCC) were collected, together with 15 normal kidney samples as controls, and for each sample the genome-wide DNA and RNA data were obtained for comparison using Affymetrix 100K SNP and HGU133plus2 gene expression chips, respectively. The DNA and RNA data was summarized by both chromosome arm and cytogenetic banding patterns and compared. The result of this analysis revealed that the two summarized data sets used to identify cytogenetic changes agreed well. However, some differences between the two were also identified. These differences of large-scale gene expression deregulation without evidence of the comparable DNA copy number alterations may be the result of known mechanisms, such as large-scale methylation or chromosome inactivation, or may be the result of some new mechanism of DNA-RNA translation. The usefulness of the combined data set for identifying regions of mutated genes is also discussed.

Coronary stent restenosis in patients treated with cilostazol.

BACKGROUND: Restenosis after implantation of coronary artery stents remains a significant clinical problem. We undertook a randomized, double-blind, placebo-controlled trial to determine whether cilostazol, a drug that suppresses intimal proliferation, would reduce renarrowing in patients after stent implantation in native coronary arteries. METHODS AND RESULTS: We assigned 705 patients who had successful coronary stent implantation to receive, in addition to aspirin, cilostazol 100 mg BID or placebo for 6 months; clopidogrel 75 mg daily was administered to all patients for 30 days. Restenosis was determined by quantitative coronary angiography at 6 months. The minimal luminal diameter at 6 months for cilostazol-treated patients was 1.77 mm for the analysis segment (stent plus 5-mm borders) compared with 1.62 mm in the placebo group (P=0.01). Restenosis, defined as > or =50% narrowing, occurred in 22.0% of patients in the cilostazol group and in 34.5% of the placebo group (P=0.002), a 36% relative risk reduction. Restenosis was significantly lower in cilostazol-treated diabetics (17.7% versus 37.7%, P=0.01) and in those with small vessels (23.6% versus 35.2%, P=0.02), long lesions (29.9% versus 46.6%, P=0.04), and left anterior descending coronary artery site (19.3% versus 39.8%, P=0.001). There was no difference in bleeding, rehospitalization, target-vessel revascularization, myocardial infarction, or death. CONCLUSIONS: Treatment with the drug cilostazol resulted in a significantly larger minimal luminal diameter and a significantly lower binary restenosis rate compared with placebo-treated patients. These favorable effects were apparent in patients at high risk for restenosis.

Incidence of aspirin nonresponsiveness using the Ultegra Rapid Platelet Function Assay-ASA.

We report the incidence of aspirin nonresponsiveness in a prospective, multicenter registry (n=422 patients) to be 23% using the Ultegra Rapid Platelet Function Assay-ASA, and determined a history of coronary artery disease to be associated with twice the odds of being an aspirin nonresponder (odds ratio 2.01, 95% confidence interval 1.189 to 3.411, p=0.009). Further prospective studies are needed to correlate aspirin nonresponsiveness to adverse clinical events.