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: Some patients converted from ventricular fibrillation to organized rhythms by defibrillation - trained ambulance technicians(EMT - Ds) will refibrillate before hospital arrival.The authors analyzed 271 cases of ventricular fibrillation managed by EMT - Ds working without paramedic back - up.Of 111 patients initially converted to organized rhythms, 19(17 % ) refibrillated, 11(58 % ) of whom were reconverted to perfusing rhythms, including nine of 11(82 % ) who had spontaneous pulses prior to refibrillation.Among patients initially converted to organized rhythms, hospital admission rates were lower for patients who refibrillated than for patients who did not(53 % versus 76 % , P = NS), although discharge rates were virtually identical(37 % and 35 % , respectively).Scene - to - hospital transport times were not predictively associated with either the frequency of refibrillation or patient outcome.Defibrillation - trained EMTs can effectively manage refibrillation with additional shocks and are not at a significant disadvantage when paramedic back - up is not available.
Example output: Ventricular Fibrillation
Example explanation: This term is directly present in the abstract and it is one of the main topic in it. So can be chosen as the medical subject heading.
Q: Abstract: Twenty one cases of amyloidosis of the lower respiratory tract were seen at a single center. In three patients, multifocal bronchial amyloid plaques led to stenosis and atelectasis, and in two, small pseudotumor masses were an incidental bronchoscopic finding. Two patients had nodular parenchymal amyloidosis, in one of whom the lesions were progressive and in the other static. Fifteen patients had diffuse parenchymal amyloidosis. Two of these had severe interstitial involvement and died in respiratory failure; eight had congestive cardiac failure, and parenchymal amyloidosis was a post-mortem finding; two had senile cardiorespiratory amyloidosis, also found at autopsy; and in three, the amyloidosis was associated with malignancy. The degree of respiratory embarrassment seemed to be related to the amount of amyloid in the gas diffusion zones, irrespective of the etiology of amyloidosis.
A:
Adult