serum gastrin and gastric endocrine cell numerical densities were examined in 22 patients with long-standing zollinger-ellison syndrome who were receiving either ranitidine , omeprazole , or other antisecretory drugs ( sms 201-995 or pirenzepine with or without ranitidine ) for long periods of time .
C0043515
zollinger-ellison syndrome
C0028978
omeprazole