Corticosteroid co-treatment induces resistance to chemotherapy in surgical resections, xenografts and established cell lines of pancreatic cancer

BACKGROUND: Chemotherapy for pancreatic carcinoma often has severe side effects that limit its efficacy. The glucocorticoid (GC) dexamethasone (DEX) is frequently used as co-treatment to prevent side effects of chemotherapy such as nausea, for palliative purposes and to treat allergic reactions. While the potent pro-apoptotic properties and the supportive effects of GCs to tumour therapy in lymphoid cells are well studied, the impact of GCs to cytotoxic treatment of pancreatic carcinoma is unknown. METHODS: A prospective study of DEX-mediated resistance was performed using a pancreatic carcinoma xenografted to nude mice, 20 surgical resections and 10 established pancreatic carcinoma cell lines. Anti-apoptotic signaling in response to DEX was examined by Western blot analysis. RESULTS: In vitro, DEX inhibited drug-induced apoptosis and promoted the growth in all of 10 examined malignant cells. Ex vivo, DEX used in physiological concentrations significantly prevented the cytotoxic effect of gemcitabine and cisplatin in 18 of 20 freshly isolated cell lines from resected pancreatic tumours. No correlation with age, gender, histology, TNM and induction of therapy resistance by DEX co-treatment could be detected. In vivo, DEX totally prevented cytotoxicity of chemotherapy to pancreatic carcinoma cells xenografted to nude mice. Mechanistically, DEX upregulated pro-survival factors and anti-apoptotic genes in established pancreatic carcinoma cells. CONCLUSION: These data show that DEX induces therapy resistance in pancreatic carcinoma cells and raise the question whether GC-mediated protection of tumour cells from cancer therapy may be dangerous for patients

rHuEPO and treatment outcomes: the clinical experience

Increasingly, anemia is being recognized as a negative prognostic and predictive factor for patients undergoing chemotherapy, radiation therapy, or a combination of these treatment modalities. The results of clinical studies have shown correlations between anemia and shorter survival times in patients with a wide variety of solid tumors and hematologic malignancies, including lung, ovarian, breast, and head/neck cancers, non-Hodgkin's lymphoma, Hodgkin's disease, Waidenstrom's macroglobulinemia, and chronic lymphocytic leukemia. Also, anemia has been shown to predict treatment response in patients with ovarian, cervical, and urothelial cancers, mantle cell lymphoma, and chronic lymphocytic leukemia, as well as refractory/relapsed acute myelogenous leukemia. Based on the presumed causal relationship between anemia and poor patient outcome, several studies have examined the influence of epoetin alfa (a recombinant human erythropoietin) on outcomes in anemic patients undergoing cancer treatment. The results of these studies have been encouraging, with indications of greater locoregional tumor control and higher response rates in epoetin alfa-treated patients. Additionally, epoetin alfa therapy, by correcting anemia, has been shown to improve a patient's energy level, ability to perform daily activities, and overall quality of life (QOL). Such effects not only enhance a patient's general well-being, but may also increase their tolerance of, and willingness to undergo, full courses of their cancer therapy in a timely manner. These findings support the use of epoetin alfa to achieve gains in QOL and cancer treatment outcomes in anemic cancer patients and suggest that additional studies be conducted to further investigate the potential benefits of this agent in regard to improved outcomes

Comparison of the elongational behavior of various polyolefins in uniaxial and equibiaxial flows

For processing operations with a pronounced elongational component, it was found that the uniformity of extruded items is improved by the presence of strain hardening usually measured in uniaxial elongation. Many processing operations such as foaming, film blowing, and blow molding are dominated by biaxial deformations, however, and therefore, the question arises how strain hardening in uniaxial and biaxial deformation compares. Besides a linear and long-chain branched PP, one classical LDPE, an HDPE pipe extrusion grade with a bimodal MMD, and a LCB-mPE were also characterized. For the measurements in uniaxial elongation the Munstedt tensile rheometer (MTR) and the ARES-EVF were used, while the lubricated flow method was applied for equibiaxial deformation. It was found that the strain hardening in uniaxial elongation is more pronounced. The dependence of strain hardening on strain rate is qualitatively the same in both modes. In the range of strain rates, the chosen long-chain branched LDPE and PP exhibit a strain hardening, which is approximately independent of the elongational rates applied, whereas for the HDPE it becomes smaller with increasing rate

Entwicklung von fluessigkristallinen Polymeren als Mantelmaterial fuer elektronische Bauelemente

A joint research project was directed towards the investigation into the feasibility of substituting currently used thermosetting resins for the encapsulation of electronic components by mouldable thermoplasts. Materials based on liquid crystalline polymers (LCP) appeared to be favourable in view of their excellent flow characteristics, inherent inflammability and mouldability. Initially tested materials derived from BASF developmental LCP exhibited sufficient thermal conductivity and low ion content levels. The additional requirements of stability towards hydrolysis and soldering as well as good welding line strength, however, were met only by blends of LCP with poly(aryletherketone)s (PAEK). Adherence of these materials to lead frame metal surfaces was investigated by a team of the Fraunhofer Institute of Applied Materials Research (FhG-IFAM). A minimised temperature difference between thermoplast melt and mould was recognised to be decisive for good adherence. The structural stability was significantly enhanced by introducing a polyimide layer between thermoplast and lead frame. The developmental materials were evaluated by SIEMENS for direct and indirect (premoulded packaging) sheathing. With direct sheathing using the LCP/PAEK blends ''wire sweeps'' were unavoidable. Promising results were obtained with the same materials under conditions of premoulded packaging techniques, among which heated tool welding proved to be the best suited welding process. High potential of the developed blends in system packaging is expected providing new prospects for the electronics industryAvailable from TIB Hannover: F93B1281+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Surgery for recurrent ovarian cancer: role of peritoneal carcinomatosis: exploratory analysis of the DESKTOP I Trial about risk factors, surgical implications, and prognostic value of peritoneal carcinomatosis

BACKGROUND: Almost all retrospective trials pointed out that a benefit of surgery for recurrent ovarian cancer may be limited to patients in whom a macroscopic complete resection could be achieved. Peritoneal carcinomatosis has been reported to be either a negative predictor for resectability or a negative prognostic factor, or both. The role of peritoneal carcinomatosis in a multicenter trial was investigated. METHODS: Exploratory analysis of the DESKTOP I trial (multicenter trial of patients undergoing surgery for recurrent ovarian cancer, 2000 to 2003). RESULTS: A total of 125 patients (50%) who underwent surgery for recurrent ovarian cancer had peritoneal carcinomatosis. Univariate analyses showed worse overall survival for patients with peritoneal carcinomatosis compared with patients without carcinomatosis (P < .0001). Patients with and without peritoneal carcinomatosis had a complete resection rate of 26% and 74%, respectively (P < .0001). This corresponded with the observation that patients with complete resection had a better prognosis than those with minimal residual disease of 1 to 5 mm, which commonly reflects peritoneal carcinomatosis (P = .0002). However, patients who underwent complete resection, despite peritoneal carcinomatosis, had a 2-year survival rate of 77%, which was similar to the 2-year survival rate of patients with completely debulked disease who did not have peritoneal carcinomatosis (81%) (P = .96). Analysis of prognostic factors did not show any independent effect of peritoneal carcinomatosis on survival in patients who underwent complete resection. CONCLUSIONS: Peritoneal carcinomatosis was a negative predictor for complete resection but had no effect on prognosis if complete resection could be achieved. Improving surgical skills might be one step to increase the proportion of patients who might benefit from surgery for recurrent disease