IMMUNOSENSOR SYSTEMS USING LIPOSOMES AND PLANAR LIPID BILAYER MEMBRANES FOR ION-CHANNEL MODEL SENSORS

For the purpose of constructing a new biosensor which mimics the concept of "ion-channel", two approaches were examined: l)liposome systems, and 2)planar lipid bilayer membrane systems. In both cases, some interaction such as immunoreaction, electrostatruneh dıpole,sand hydrophobic interaction of a stimulus with a model receptor site at the surface of lipid membranes triggers the change in permeation of marker ions across the lipid bilayer membranes. This change in permeation of the marker ions is subsequently monitored electrochemically, which is a direct but much amplified measure of the analyte to be assayed

Outcome of maintenance systemic chemotherapy with drug-free interval for metastatic urothelial carcinoma

Objective: Aiming to achieve long-term disease control, maintenance systemic chemotherapy (MSC) with a 1-3-month drug-free interval is continued in selected patients. We report our experience of MSC for metastatic urothelial carcinoma (UC). Methods: Of 228 metastatic UC patients treated with systemic chemotherapy, 40 (17.5%, 40/228) had continuously undergone MSC. Data on the regimen, cycle number, and reason for the discontinuation of MSC were also collected. We analyzed OS from the initiation of MSC until death or the last follow-up, using the log-rank test to assess the significance of differences. Results: The median number of cycles of chemotherapy was 6, and the responses were CR in 6, PR in 20, SD in 13, and PD in 1 before MSC. Gemcitabine plus CDDP or carboplatin was mainly performed as MSC (70%, 28/40). MSC was repeated quarterly in 30 (75%, 30/40), every two months in 8 (20%, 8/40), and with other intervals in 2 (5%, 2/40). Overall, a median of 3.5 cycles (range: 1-29) of MSC was performed. The reason for the discontinuation of MSC was PD in 24 (60%, 24/40), favorable disease control in 9 (22.5%, 9/40), and myelosuppression in 3 (7.5%, 3/40), and for other reasons in 2 (5%, 2/40). MSC was ongoing in 2 (5%, 2/40). The median OS was 27 months from the initiation of MSC. PS0 (P = 0.0169), the absence of lung metastasis (P = 0.0387), and resection of the primary site (P = 0.0495) were associated with long-term survival after MSC. Conclusions: In selected patients, long-term systemic chemotherapy could be performed with a drug-free interval. Our maintenance strategy with cytotoxic drugs may become one of the treatment options for long-term disease control