Lower leg blood flow was measured at rest and both during and after graduated bicycle exercise in five healthy men and in seventeen patients suffering from various degrees of obliterating arteriosclerosis of the lower limbs. A thermodilution technique was used for flow determinations. The subject exercised in the sitting position and the work load was increased stepwise from a starting load of 100 kpm/min (100 kpm/min load increment every second minute until exhaustion). Three flow phases were depicted during and after the exercise: the aerobic phase, the phase of relative ischaemia and a postexercise phase. During exercise, lower leg blood flow increased approximately twenty times in healthy subjects, while in the arteriosclerotic subjects there was a two-fold to ten-fold increase in flow. In patients with serious distal and proximal stenoses a proximal steal phenomenon was demonstrated during submaximal and maximal exercise. A close correlation was found between maximum individual work load capacity and maximum lower leg blood flow (r = 0.71, P less than 0.001). In the patient group lower leg blood flow at a certain work load was 45% (P less than 0.001) higher in the sitting than in the supine position.

The skin and colonic temperatures were recorded in frogs (Rana esculenta) which had selected a suitable microenvironment in a box filled with 2-3 cm water. The water temperatures ranged from 0 degrees C to + 40 degrees C. Such measurements were performed before and after intraperitoneal injections of killed pathogenic bacteria (M. xenopi and M. range), killed non-pathogenic bacteria (M. aquae II) and 0.9% sterile saline, intraperitoneal injections of blood plasma from frogs pre-injected with killed M. ranae, injections of PGE1 into the brain. The injections of pathogenic bacterial endotoxin caused, after latencies of 5-120 min, higher preferred water temperatures, which produced an average maximum colonic temperature increase of 6.5 degrees C +/- 1.0 degrees C (S.E.) (p less than 0.001). The non-pathogenic bacteria and sterile saline caused no temperature change. Monophasic hyperthermia of shorter latency was caused by injections of blood plasma from frog preinjected with M. ranae. Monophasic hyperthermia of the shortest latency was observed after diencephalic injections of PGE1. Based on their similarity we suggest that ectothermic and endothermic fever have a common phylogenetic origin.

Eels (Anguilla anguilh) which were exposed to copper-contaminated fresh water (30-60 pg Cu/l) died with signs of vibriosis (Vibrio anguillarum). Eels kept in non-contaminated fresh water (<6 Fg Cu/l) remained healthy. V. anguiIIarum was shown to be present in the eels with symptoms of vibriosis. We suggest V. anguillarurn is a common inhabitant of eels and copper can change a commensal association between fish and bacterium to one of pathogenicity.

Seven elite male cross-country skiers trained for 3 weeks at an altitude of 1900 m. Haemoglobin concentration ([Hb]), haematocrit (Hct) (obtained from venous blood), maximal oxygen uptake (VO2 max) and energy expenditure during a standard submaximal workload were measured before and after training at altitude, and 1 year later while training at sea level (control). Both [Hb] and Hct increased significantly, and the skiers with the lowest initial [Hb] and Hct experienced the largest increases during training at altitude. The increase in blood lactate (BLa) concentration (using haemolysed capillary blood) during a standard submaximal exercise test was significantly lower after training at altitude than before it or 1 year later (control). A significant correlation was found between the magnitude of increase in [Hb] and Hct and the difference in the lactate response to the standard submaximal workload pre- and post-altitude training. Although VO2 max remained unchanged, lower BLa concentration during the submaximal test probably reflects an improved ability to exercise at higher submaximal workloads shortly after training at altitude compared with pre-altitude training. It is suggested that subjects with low initial [Hb] and Hct improve their aerobic performance capacity most during altitude training.