Rotavirus infection was demonstrated in 168 (29·3%) of 573 children hospitalized for acute diarrhoea in Rome between January 1982 and December 1984. Laboratory diagnosis of these infections was made by transmission electron microscopy and enzyme immunoassay techniques with an overall agreement of 91·3%. Astroviruses, adenoviruses and small round viruses were detected in the faeces of 36 patients (6·4%). Whereas in 1982 rotavirus positive patients were clustered in the winter and following spring, in the following years cases were recorded all year round. The median age of patients with rotavirus infections was 17, 10 and 11·5 months in 1982, 1983 and 1984, respectively. In addition, a smaller number of rotavirus positive cases were admitted in 1983 when compared to those admitted during the previous as well as the subsequent years. It is suggested that a herd immunity was induced in the population by epidemic spread of rotavirus in the first half of 1982.

Cryptosporidium oocysts were observed in the stools of 9 (7·2%) of 124 Italian children with diarrhoea, examined during the period 1 January—31 December 1984. In two children, the parasite was associated with other enteric pathogens. The duration of diarrhoea was 2–30 days, with a median of 6 days. In all cases the infection was self limiting. The mean age of the Cryptosporidium-positive children was 34 months, and all cases occurred in the warm season. Cryptosporidium was found to be the third most common enteric pathogen after rotavirus and Salmonella spp.

This paper summarizes some studies recently carried out in this Institute in the field of cancer chemotherapy.

Three main groups of data are reported:

a) different sensitivity to chemotherapy of the same tumor transplanted in different sites of the body;

b) a method to study cancer dissemination as a basis for cancer chemotherapy;

c) a system to perfuse tissue culture with the blood of living animals as an approach to study duration of action of antitumoral drugs.