The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.

These results form a rational basis for the design of clinical trials to evaluate the expression of these enzymes as predictors for treatment outcome.

Background: Patients on long-term dialysis eventually develop amyloid deposits with β₂-microglobulin as a predominant component. Although several studies have suggested that high-flux membranes reduce β₂-microglobulin in plasma compared with low-flux dialyzers, the mechanisms underlying this observation are still discussed. Methods: We revisited this important subject and measured β₂-microglobulin in the plasma of healthy individuals (n = 8), and patients undergoing hemodialysis (n = 20) who for assigned periods of time were either treated with a low-flux membrane (cuprophan) or high-flux (polyamide) dialyzer with an ELISA. The number of blood cells was determined by FACS. β₂-Microglobulin was also measured on the surface of granulocytes, lymphocytes, and monocytes before, directly after, and 4 h after hemodialysis. Expression of β₂-microglobulin, c-fos, tumor necrosis factor-α (TNF-α), and interleukin-1 mRNA was determined in whole blood samples with quantitative RT-PCR using an internal standard in parallel. In the second part of the study, patients were assigned in a two-group cross-over design either to low- or high-flux dialyzers (n = 9 in each group), and dialyzer membranes were changed every 4 weeks for two consecutive periods. Serum β₂-microglobulin concentrations were measured at the end of each period. Results: Healthy controls had a low plasma β₂-microglobulin level of 1.2 ± 0.3 mg/l. Before hemodialysis, patients on low-flux dialyzers had a plasma β₂-microglobulin level of 42.0 ± 14.0 mg/l, patients treated with high-flux dialyzers 21.5 ± 10.8 mg/l (p < 0.05 vs. low-flux dialyzers). In contrast, there was no significant difference in plasma concentrations of active transforming growth factor-β1 with the two different membrane types. The difference in serum β₂-microglobulin between low- and high-flux membranes was more prominent directly after hemodialysis as well as 4 h after hemodialysis compared with the values directly before the start of treatment. At all studied time-points, leukocytes and platelets were significantly higher in patients on low-flux membranes. Healthy control persons exhibited a significantly higher amount of β₂-microglobulin bound to granulocytes, lymphocytes, and monocytes compared with dialysis patients. Interestingly, β₂-microglobulin bound to granulocytes, lymphocytes, and monocytes was significantly increased in patients treated with high-flux membranes compared with low-flux filters. Quantitative RT-PCR revealed no significant difference in β₂-microglobulin expression in whole blood before hemodialysis, directly after hemodialysis, and 4 h after hemodialysis. However, TNF-α and c-fos transcripts were significantly higher in whole blood obtained from patients treated with low-flux membranes compared to high-flux dialyzers. The two-group cross-over study over three periods of 4 weeks revealed that switching from low-flux to high-flux dialyzers si...

Enzastaurin (LY317615.HCl) is an antiproliferative agent targeted specifically against PKC-beta. We have investigated the antitumoral effects of Enzastaurin against human cancer cell lines and freshly explanted human tumor tissue. Ten human cancer cell lines (NSCLC, colon, and thyroid) and human tumor specimens from 72 patients were used for in vitro studies in a cloning assay (HTCA). Cell lines and primary tumor cells were exposed to Enzastaurin for either 1 h or 7 days, or for 1 h or 21 days. At clinically achievable concentrations of Enzastaurin, inhibition of cell growth was observed for lung, colorectal, and thyroid cancer cell lines in a concentration dependent manner. Patient specimens exposed 1 h or 21 days to 1,400 nM Enzastaurin demonstrated inhibition rates of 24 and 32%, respectively. Marked inhibitory effects were observed in breast, thyroid, head/neck, non-small cell lung cancer, pancreatic cancer, and melanoma. In addition to its established antiangiogenic effects, Enzastaurin has direct antitumor activity against established human cancer cell lines and primary tumor specimens. This warrants further clinical development in tumors which have been identified to be potentially sensitive to Enzastaurin.

Background: Although many mediators involved in the pathogenesis of fibrosis are known, its precise mechanism is still unknown. In vitro experiments may contribute to the recognition of cellular changes which also take place during fibrosis. Methods: Renal tubular epithelial cells (EPC), mesangial cells (MC) and glomerular endothelial cells (GEDC) as well as endothelial cells (EDC) and myofibroblasts (MF) from cattle were isolated to measure the proliferation and protein synthesis in the presence of individual and combined cytokines/growth factors in cell cultures. Results: Cytokines stimulating or permitting the proliferation of myofibroblast-like cells (MFLC) (MC and MF), caused damage of endothelial cells (EDC, GEDC), whereas EPC were stable. The proliferation of MFLC was strongly stimulated by PDGF-BB and bFGF and elevated more than twofold in the presence of interleukin 4 (IL-4), but IL-4 alone had no effect. Furthermore, the proliferation of transdifferentiated endothelial cells (TEC), obtained by incubation of EDC with TNFα and bFGF, was stimulated with both PDGF-BB/IL-4 and bFGF/IL-4 in the same way and proved to be stable with respect to TNFα. Conclusion: Interleukin 4 co-stimulates the PDGF-BB- and bFGF-mediated proliferation of MC, MF, and TEC. TNFα does not inhibit the proliferation of extracellular matrix-synthesizing cells, but has an inhibitory or even toxic effect on EDC and GEDC. It may be concluded that cytokines released in inflamed renal tissue influence tubulointerstitial cells in different ways, resulting in progressive tissue damage and fibrosis in which the EDC would be the most sensitive cells. Thus, we speculate that microvascular injury in these areas leads to ischemia and malnutrition of tubular EPC and may be responsible for ongoing tubular damage and resulting renal interstitial fibrosis.