Purpose: A major obstacle in chemotherapy is treatment failure due to anticancer drug resistance. The emergence of acquired resistance results from host factors and genetic or epigenetic changes in the cancer cells. The purpose of this study was to identify differentially expressed genes associated with acquisition of resistance in human gastric cancer cells.Experimental Design: We performed global gene expression analysis in the acquired drug-resistant gastric cancer cell lines to the commonly used drugs 5-fluorouracil, doxorubicin, and cisplatin using Affymetrix HG-U133A microarray. The gene expression patterns of 10 chemoresistant gastric cancer cell lines were compared with those of four parent cell lines using fold-change and Wilcoxon's test for data analysis.Results: We identified over 250 genes differentially expressed in 5-fluorouracil-, cisplatin-, or doxorubicin-resistant gastric cancer cell lines. Our expression analysis also identified eight multidrug resistance candidate genes that were associated with resistance to two or more of the tested chemotherapeutic agents. Among these, midkine (MDK), a heparin-binding growth factor, was overexpressed in all drug-resistant cell lines, strongly suggesting that MDK might contribute to multidrug resistance in gastric cancer cells.Conclusions: Our investigation provides comprehensive gene information associated with acquired resistance to anticancer drugs in gastric cancer cells and a basis for additional functional studies.

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Resource utilization is one of the emerging problems in many-chip SSDs. In this paper, we propose Sprin kler, a novel device-level SSD controller, which targets maximizing resource utilization and achieving high per formance without additional NAND flash chips. Specifi cally, Sprinkler relaxes parallelism dependency by schedul ing I/O requests based on internal resource layout rather than the order imposed by the device-level queue. In addi tion, Sprinkler improves flash-level parallelism and reduces the number of transactions (i.e., improves transactional locality) by over-committing flash memory requests to spe cific resources. Our extensive experimental evaluation us ing a cycle-accurate large-scale SSD simulation framework shows that a many-chip SSD equipped with our Sprinkler provides at least 56.6% shorter latency and 1.8 -2.2 times better throughput than the state-of-the-art SSD controllers. Further, it improves overall resource utilization by 68.8% under dif f erent I/O request patterns and provides, on aver age, 80.2% more flash-level parallelism by reducing half of the flash memory requests at runtime.

Coronary angiography is the established routine imaging modality for patients with coronary artery disease. In recent years, the number of these procedures has increased remarkably. Complications associated with this invasive approach are in the range of 1.5% and the mortality is 0.1%. A further reduction of risk appears difficult to achieve because of the invasive nature of the procedure. Therefore, efforts have been made to image coronary arteries by non-invasive or minimally invasive techniques. One method under development is dichromography. This technique is based on subtraction of two images at different energies. Dichromography allows imaging of small fast-moving objects like the coronary arteries including distal parts and sidebranches after intravenous injection of a contrast material. Two images with monochromatic x-rays just below and above the absorption K-edge of the contrast agent iodine at 33.17 keV are obtained simultaneously and logarithmically subtracted. Monochromatic x-rays of sufficient intensity to visualize coronary arteries of 1 mm diameter with a low iodine mass density of are only provided by synchrotron radiation. At the Hamburger Synchrotronstrahlungslabor HASYLAB at DESY in Hamburg, Germany the system NIKOS was developed for dichromography. This system consists of six main parts: a wiggler beamline, a two beam monochromator, a safety system, a scanning device with a seat for the patient, a two-line detector, and a computer system. After initial experimental studies with dogs, human patients have been investigated since 1990. Results of investigated patients demonstrate the feasibility and safety of the method together with high diagnostic accuracy. All cases were follow-up investigations after bypass surgery or interventions like angioplasty with a balloon catheter or rotablation with a very fast milling tool. A large-scale study has been underway since June 1997 to validate the diagnostic sensitivity and specificity compared with selective coronary angiography.