Despite five additional trials, this updated review is still an unsatisfactory basis for practice. The trials were small and generally of moderate quality. The only evidence of benefit comes for within-group short-term changes following injection. The finding that placebo saline injection was followed by a similar symptomatic improvement questions the mechanism of any effects. There were no trials in comparison with pelvic floor muscle training -the obvious non-surgical comparator. Greater symptomatic improvement was observed after surgery, although these advantages need to be set against likely higher risks. No clear-cut conclusions could be drawn from trials comparing alternative agents; one small trial suggests that periurethral injection may carry more risks than transurethral injection. The single trial of autologous fat provides a reminder that periurethral injections can occasionally cause serious side-effects. Pending further evidence, injection therapy may represent a useful option for short-term symptomatic relief amongst selected women with co-morbidity that precludes anaesthesia - two or three injections are likely to be required to achieve a satisfactory result.

Data from the available randomised trials suggest, but do not prove, that periurethral injection of established manufactured bulking agents results in subjective and objective short term improvement of symptomatic female stress urinary incontinence in adults. Future recommendation as a first line treatment would require evidence of patient benefit and cost-effectiveness from randomised trials involving placebo and conservative treatment arms. Future studies should also record long-term outcome and monitor for delayed particle migration. Injection therapy is probably inferior to surgery but a long term comparative study against a single standard procedure (Burch colposuspension) is required to prove this. It is recommended that phase III studies of newer agents will not be worthwhile until the aforementioned trials have been performed and a rationale for the use of injection therapy decided. For women with extensive co-morbidity precluding anaesthesia, injection therapy may represent a useful option for relief of symptoms for a 12 month period although 2 or 3 injections are likely to be required to achieve a satisfactory result.

No abstract

The technique of labelled mitoses was used to examine cell proliferation within grafts of human colonic and rectal tumours in immune deprived mice. Most of the data were obtained on the first passage but in some cases up to the third passage was used. It was found to be difficult to obtain precise kinetic data on this type of tumour material, but the results did allow some estimates to be made, particularly of the duration of the G2 and S phases of the mitotic cycle. The average G2 duration was 6 h and the average S phase was 14 h. It is concluded that whilst xenografts may differ in a number of respects from the tumour in the patient, they nevertheless constitute a type of experimental tumour that is worthy of further study.