Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Example Input: Abstract: An accurate diagnosis is essential in managing musculoskeletal problems in children. Active treatment is only occasionally necessary and should meet the criteria of being essential, effective, and prudent.
Example Output: Bone and Bones

Example Input: Abstract: Angiotensin II (AII) binds to specific receptors in the lactotroph and stimulates PRL secretion from isolated rat pituitary cells. Since estrogens exert major regulatory actions on PRL secretion, the effects of estradiol (E2) on pituitary AII receptors and PRL responses were studied in vivo and in cultured rat anterior pituitary cells. In female rats, treatment with E2-containing Silastic capsules for 4 days caused a significant increase in PRA from 1.3 to 3 ng/ml X min and a 38% decrease in the binding of [125I]AII to anterior pituitary membrane-rich fractions (P less than 0.01). In vitro studies showed that treatment of cultured anterior pituitary cells with 1 nM E2 for 4 days caused a 57 +/- 6% decrease in AII receptor concentration with no change in binding affinity. Reduction of AII receptors by E2 in 4-day cultures was dose dependent and was demonstrable with E2 concentrations that occur in plasma during the estrous cycle (0.01-1 nM). The decrease in AII receptors in cells incubated with 1 nM E2 was near maximum after 24 h of culture, and results were similar when receptor concentrations were calculated per unit protein or per cell. Despite the substantial decrease in AII receptors, E2 treatment did not specifically decrease the responsiveness of the pituitary cells to AII stimulation. Thus, PRL responses to AII (10 nM) or TRH (100 nM) were unchanged after 1 day of E2 treatment and were increased after 4 days of treatment. These findings demonstrate that E2 has a direct inhibitory action on expression of pituitary AII receptors that is not accompanied by a decrease in AII-stimulated PRL secretion. In the rat pituitary, estrogen modulation of postreceptor events is the predominant determinant of lactotroph responsiveness during stimulation of PRL release by AII.
Example Output: Animal

Example Input: Abstract: It is clear that some synovial inflammation occurs in joints affected by osteoarthritis (OA) and it is well recognized that many patients with OA experience a decrease in pain and joint stiffness following administration of salicylates or other nonsteroidal antiinflammatory drugs (NSAIDs). However, neither the extent to which synovitis contributes to the cartilage breakdown in OA nor the effects of chronic administration of NSAIDs on the natural history of OA in humans is known. Recent studies indicate that several NSAIDs, including salicylates, suppress proteoglycan synthesis in articular cartilage in vitro. The effect on OA cartilage is more marked than that on normal cartilage. Other studies show that salicylate feeding may suppress proteoglycan metabolism in degenerating cartilage in vivo, aggravating the decrease in proteoglycan content caused by the disease itself. However, no effect of salicylates on normal articular cartilage has been observed in vivo. In damaged cartilage the magnitude of NSAID-induced suppression of proteoglycan metabolism appears to be related inversely to the proteoglycan content of the tissue. In addition, the NSAIDs used in treatment of arthritis today may differ with respect to their in vivo effects on articular cartilage metabolism due, in part, to differences between the molar concentrations of these drugs in synovial fluid.
Example Output:
Animal

