The degree of invasiveness of thoracic surgery may influence the extent of immunosuppression in patients undergoing pulmonary lobectomy for pulmonary neoplasm.

Summary. Prostaglandin precursor fatty acids, predominantly arachidonic acid, were found in the different lipid classes of guinea-pig uterus and plasma on Days 7 and 15 of the oestrous cycle. Of the total arachidonic acid in the uterus, 93% was esterified to uterine phospholipids, of which 80% was bound to phosphatidylcholine and phosphatidylethanolamine. There was a significant decrease in the quantity of arachidonic acid bound to phosphatidylcholine between Days 7 and 15 of the oestrous cycle. Less than 0\m=.\1% of the uterine arachidonic acid was present in the unesterified form. It is suggested that phosphatidylcholine may form the source of phosphatidyl for uterine prostaglandin synthesis in the guinea-pig.