Photodynamic therapy involves light-induced destruction of tumors containing a photosensitizer such as hematoporphyrin derivative. We conducted a collaborative study to evaluate the efficacy of this form of therapy in treating superficial transitional-cell carcinoma of the bladder. Thirty-seven patients were evaluated and 20 were selected for treatment. A total of 50 papillary tumors and 3 areas of carcinoma in situ were treated. All except two tumors were smaller than 2.5 cm. Assessments for treatment response and toxicity were carried out three months after treatment. The initial diagnosis of one patient was revised after the biopsy material was reviewed, and this patient was not included in the analysis. Complete eradication of all tumors was observed in 9 of 19 patients (47 percent), including those with carcinoma in situ. In the remaining 10 of these 19 patients, 13 tumors could not be eradicated (the overall eradication rate was 37 of 50 tumors [74 percent]), but 9 of the 10 patients had a reduction in tumor size, number, or both of 50 percent or more. We conclude that photodynamic therapy is useful in the treatment of superficial transitional-cell carcinoma of the bladder, but controlled trials will be required to define its place in the treatment of cancer.

Multi-metallic complexes (of Al, Zn) derived from imine-based ligands effectively operate as catalysts for the ring opening polymerization (ROP) of ε-caprolactone (ε-CL), δ-valerolactone (δ-VL) and co-polymerization thereof.

The normal swine oesophagus was heated using an intracavity microwave radiator for 30 min at 45, 46, 47, 48 and 49 degrees C. The animals were sacrificed 48 h or 30 days later. The degree of heat injury was evaluated on an histological score system with a maximum possible damage score of 100 per cent. The acute heat injury (48 h after heating) at these temperatures was 2, 17, 40, 50 and 67 per cent respectively. The main feature of acute heat damage was degenerative necrosis or thrombosis of blood vessels at the oesophageal wall. This occurred only in one out of nine cases at 45 and 46 degrees C heating, but in seven out of nine cases at 48 and 49 degrees C. The main feature of late heat damage was fibrosis. The score of chronic damage for the above groups was 12, 23, 30, 34 and 51 per cent, respectively. When animals were preheated at 44 degrees C for 30 min and then reheated at 45-49 degrees C 4 h later, we found that preheating could provide about 2 degrees C protection. From the above data, we suggest that 45 degrees C and 30 min heating is a safe dose for normal oesophageal tissue.

No abstract