Characterization of the expression of hsp90 genes of Brassica napus by northern blot analysis and immunoblotting showed that the hsp90 mRNA and protein are present in all B. napus tissues examined, albeit at different levels. High levels of hsp90 mRNA and protein were found in young and rapidly dividing tissues such as shoot apices and flower buds, suggesting that hsp90 may have an important role in plant growth and development. A significant increase in hsp90 mRNA levels was detected in seedlings exposed to 5°C. The transcript levels reached a maximum within 1 d of cold treatment and remained elevated for the entire duration of cold treatment. The levels of hsp90 mRNA rapidly decreased to the leve1 found in control plants upon return to 20°C. The cold-induced accumulation of hsp90 mRNA closely resembles the expression of two previously identified cold-regulated genes of B. napus. We have also confirmed cold regulation of hsp90 mRNA in spinach (Spinacea okracea). Our results suggest a role for hsp90 in adaptation to cold temperature stress.

Rotavirus is a common cause of diarrhoea both in the community and in the hospital. Because of this, it may be difficult to determine whether crossinfection has occurred in the hospital, an important finding as review of hygienic techniques and ward closure may be indicated. We therefore investigated the use of Polyacrylamide gel electrophoresis (PAGE) of the rotavirus RNA genome as a means of distinguishing between rotavirus strains in order to assess its role in the evaluation of apparent hospital-acquired rotavirus diarrhoea. Suspected examples of hospital-acquired rotavirus gastroenteritis were studied on an infectious diseases ward and a general infant ward. PAGE analysis demonstrated that crossinfection had not occurred on the infectious diseases ward, even though this was indicated clinically; a single source outbreak involving 11 patients was confirmed on the general infant ward, as all cases showed an identical rotavirus electropherotype. Following ward closure an endemic rotavirus electropherotype was detected, which affected 17 patients over a 3-month period. Electrophoresis of rotavirus RNA is a useful and practical technique in the analysis of hospital-acquired gastroenteritis and can indicate appropriate clinical action.