In experimental animals, expression of {TAIL ~ RHAMM} was maintained for {HEAD ~ several days}, then levels dropped 
In experimental animals , expression of { TAIL ~ RHAMM } was maintained for { HEAD ~ several days } , then levels dropped
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH