After an epidemic of severe urethral strictures in cardiac surgery patients, all brand latex catheters marketed in Finland were investigated for cellular toxicity with eluates made from the catheters. Four of the seven brands, including the one involved in the stricture cases, showed marked cytotoxicity and inhibited almost all cell growth in various human cell cultures when a 30% catheter eluate was used. DNA histograms of cells cultured with toxic catheter eluate showed inhibition of DNA synthesis. Silicone catheters did not influence cell growth, which correlates with the finding that no new stricture cases were seen after the latex catheters were replaced with silicone ones. Attention is paid to the facts that international standards regarding urethral catheter toxicity are lacking and that catheter quality control is insufficient.

The aim of the present study was to examine the suitability of biodegradable polymers as materials for a urethral stent. A new urethral stent made of biodegradable self-reinforced poly-L-lactide (SR-PLLA) was implanted in 16 male rabbits after urethrotomy. Seven stents of stainless steel served as controls. The dimensions of the two types of stents were identical: length 15 mm, diameter 8.2 mm. The mechanical construction was a helical spiral. The SR-PLLA spiral was sustained with three microspirals, and the whole device was coated with DL-lactide to achieve an active initial tissue reaction and better tissue penetration. The SR-PLLA stent showed more favourable implantation properties than the steel one. Within 6 months all PLLA stents had implanted, and the tissue reaction around the stent material was minimal. The helical spiral of stainless steel induced a remarkable inflammatory reaction due to poor implantation properties. We suggest that biodegradable SR-PLLA is a promising material for a urethral stent to prevent re-stenosis of urethral strictures.

The effect of preoperative irradiation on the survival of patients with renal adenocarcinoma was studied in a clinical trial. 88 patients with verified renal carcinoma entered the trial during 1968-1972, of whom 38, selected in a randomized fashion, received preoperative irradiation to a total dose of 3 300 rads in 3 weeks, followed by extrafascial nephrectomy after a 3 week interval; in the remainder an extrafascial nephrectomy was performed immediately. Actuarial 5-year survival was 47% in the "preoperative irradiation" group and 63% in the "nephrectomy-only" group, i.e. preoperative irradiation did not improve the 5-year prognosis. Survival was also studied in P-categories of the U.I.C.C. as well as in high and low grade malignancies. In none of these groups could we find a clear tendency to a more favourable prognosis with preoperative irradiation; no statistically significant differences were found. Because no improvement in prognosis after preoperative irradiation was found in our series or any of the sub-groups, we consider preoperative irradiation not routinely indicated as an adjuvant therapy. It may be useful in some selected cases, but selecting these cases will be difficult.

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Two hundred and seventy-seven patients with advanced prostatic cancer were treated by either orchiectomy or oestrogen. During the 2-year follow-up period, the response to treatment was considered more favourable in the oestrogen group, and this response was particularly emphasised in patients with poorly differentiated tumour and metastases at the time of diagnosis. Further evaluations included the cardiovascular side effects of oestrogen therapy.