The reliability of both RIAs and regression found between serum and salivary cortisol concentrations permits the validation of saliva-sampling as a noninvasive technique for cortisol level assessment in horses.

Masked hypertension is frequently underestimated in OSAS and is nearly always present when clinic BP is above 125/83 mmHg.

a b s t r a c tDuring competition, stress may affect riders and horses. This stress can affect health, welfare, and/or performance. Our aim was to quantify stress levels during competition in horses and riders. We also searched relationships between these stress levels and performance. Twenty riders and 23 horses were followed up during a show-jumping event (26 courses) held at a riding school. Regular saliva samples taken from horses and riders were assayed to evaluate cortisol levels. We studied salivary cortisol evolution during the days of competition. There was no correlation between instantaneous sampling on horses and their riders. However, we did find a parallel between horse and rider salivary cortisol evolution curves, with a similar peak, reached 20 minutes after the course. The increase was stronger in riders than in horses. Correlations appeared between salivary cortisol concentration and performance, but stress in both partners seems to have an opposite influence on performance. Riders who showed a higher salivary cortisol increase were awarded more penalties, whereas horses that showed a higher increase in salivary cortisol performed better. Stress level measurement in riderehorse pairs would thus lead to improvement in competition conditions and performance, for horses as well as for riders.

Megakaryoblastic leukemia and transient leukemia in Down's syndrome have been reviewed using case reports from the literature and our own experience at the Hospital for Sick Children. The following conclusions have been reached: (1) approximately 20% of leukemia (excluding transient leukemia) in Down's syndrome is acute megakaryoblastic leukemia; (2) approximately 20% of all leukemia in Down's syndrome is transient leukemia; (3) transient leukemia in Down's syndrome is acute megakaryoblastic leukemia; (4) recurrence of acute megakaryoblastic leukemia occurs in 20% of the cases of transient leukemia; and (5) the incidence of acute megakaryoblastic leukemia in Down's syndrome is estimated to be 400 times that in normal children. These observations suggest that a specific form of leukemia, namely acute megakaryoblastic leukemia, has a remarkable association with Down's syndrome.