21.   In experiments performed on dogs, each animal served as its own control.

22.   For comparison, similar marker studies were performed on sections of peripheral and mesenteric lymph nodes.

23.   Endoscopy should be performed on all patients.

24.   The rather low sensitivity of symptoms relating to upper gastrointestinal disease suggests that endoscopy should be performed on all patients with iron deficiency anaemia.

25.   Endoscopic ultrasonography, successfully performed on this occasion, showed that this was due to minor local thickening of the oesophageal wall.

26.   They are labour intensive, however, and complex to perform on a large scale, for example, in clinical regimens.

27.   Histological scoring of biopsy specimens was performed on formaldehyde fixed sections.

28.   Experiments were performed on seven subjects to determine the accuracy of the method for measuring oesophageal bicarbonate content.

29.   These experiments were performed on Sprague-Dawley rats.

30.   Measurements of gastric secretion were performed on fasted animals but the mice were allowed tap water freely.