Repeated cycles of retrovirus-mediated HSVtk gene transfer plus ganciclovir increase survival of rats with peritoneal carcinomatosis.

Peritoneal carcinomatosis is a common clinical situation that requires novel therapeutic approaches. We investigated the efficiency of an HSVtk gene therapy for the treatment of peritoneal carcinomatosis induced in syngeneic rats by DHD/K12 colon carcinoma cells. In this setting, the efficiency of two different retrovirus producing cell lines (GP+AmEnv12 and FLYA13) was compared. Rats treated with a single injection of retrovirus producing cells followed by a 5-day course of ganciclovir treatment showed an increased survival as compared with control animals. Animals treated with three injections of producing cells, each followed by a 4-5-day course of ganciclovir treatment, showed an increased survival as compared with control rats and with those treated with a single cycle of retrovirus producing cells plus ganciclovir. However, only a few animals remained tumor-free after day 180. There was no difference between the two producing cell lines in any of the experiments. RT-PCR demonstrated a faint expression of the tk transgene in the liver, spleen, epiploon, bowels and the lung of the animals injected with the HSVtk producing cells, reflecting most likely the transduction of only a limited number of cells.

Non-toxic antiseptic irrigation with chlorhexidine in experimental revascularization in the rat.

The effect of different wound irrigation fluids upon femoral arteries and veins was investigated in the rat, using microsurgical techniques. Toxicity was evaluated by microscopical observation after selective staining of histological slides. Povidone-iodine, 10%, proved to be a very irritant solution, provoking an attack on the vascular endothelium and secondary thrombosis. Chlorhexidine at 0.05%, 0.02% and 0.001% was found by contrast to have a very low toxicity which was comparable to physiological saline. Experimental investigation of antiseptic solutions should not only include the determination of the antibacterial effect, but also the potential for cell toxicity, using an irrigation technique.

[Current trends in experimental peripheral nerve regeneration]. / Nouvelles orientations en régénération nerveuse périphérique expérimentale.

Large posttraumatic defects in the peripheral nervous system need to discover methods to solve the demand of nerve grafts. There is no definite answer now. The authors present a model for nervous regeneration studies. Experiments are performed in the Wistar rat. A venous isograft is used to bridge defects of various size in a divided rat sciatic nerve. The venous tube is a guide for axonal regeneration. In one series, the tube is filled with physiological saline and, in a second one, neonatal Schwann cells are injected in the venous isograft. Results recorded are a combination of quantitative methods: neurophysiology and morphometry. The injection of neonatal Schwann cells is able to stimulate nerve regeneration but not completely.