Background/Aims: Inflammatory process induced by endotoxin is one of the causes of resistance to recombinant human erythropoietin (rHuEPO) in hemodialysis patients. Thus dialysate contaminated with endotoxin may diminish response to rHuEPO. We investigated whether dose of rHuEPO could be reduced with endotoxin-free ultrafiltered dialysate. Methods: Twenty-seven chronic hemodialysis patients receiving rHuEPO were studied. The patients did not have known causes of anemia other than chronic renal failure. An endotoxin-cut polyethylene ultrafilter was installed into the dialysate fluid circuit. Hematocrit and dose of rHuEPO were monitored before and after installation. Dose of rHuEPO was adjusted to keep hematocrit at about 30%. Endotoxin concentration of dialysate was measured by commercial limulus test (Endospecy^®). Results: After installation of ultrafilter, dialysate endotoxin concentration decreased from >100 to <1.0 endotoxin units/liter (EU/l). Dose of rHuEPO decreased from 90.0 U/kg/week (median) to 57.3 U/kg/week (p < 0.05) and hematocrit increased from 30.3% (median) to 32.2% (p = 0.03) after 5 months of installation of ultrafilter. The running cost of the ultrafilter corresponded to only 4% of the cost of spared rHuEPO. Conclusions: Ultrafiltered endotoxin-free dialysate caused significant reduction in dose of rHuEPO to keep target hematocrit level. Endotoxin-cut ultrafilter was beneficial to hemodialysis patients in medical and in economical aspects.

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In multi-hop wireless networks (MWNs), hierarchical structures are important to achieve scalable routing control, as well as clustering algorithms for creating such structures and so have been extensively studied. Due to the constraints of MWNs as distributed systems, these clustering algorithms must be implemented in an autonomous and decentralized manner. In particular, ensuring transparency to network topology and node mobility is important. Spectral clustering is a technique for appropriately creating clusters regardless of the network topology. However, since this technique requires information on the entire network, it is difficult to implement it autonomously and in a decentralized manner. Therefore, autonomous and decentralized spectral clustering has only succeeded in simple grid networks. This paper proposes a spectral clustering algorithm that can be implemented in an autonomous and decentralized manner for any network topology. In this method, a certain spatial structure is generated in an autonomous and decentralized manner by using differential equation-based temporal evolution equations; clusters are then formed using the spatial structure yielded by the temporal evolution equations. We demonstrate that this method can realize spectral clustering in an autonomous and decentralized manner in a static network model and also can realize a stable cluster structure that responds to node movement in a dynamic network model. INDEX TERMSAutonomous decentralized clustering, spectral clustering, multi-hop wireless network, hierarchical routing, spectral graph theory.