Detailed Instructions: 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.
See one example below:
Problem: 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.
Solution: Ventricular Fibrillation
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.

Problem: Abstract: We studied eight women who had complex partial seizures and anovulatory cycles or inadequate luteal phases. Progesterone suppositories were given during the premenstrual phase or entire second half of the cycle in doses of 50 to 400 mg q12h. Antiseizure medication levels were kept in the therapeutic range. Average monthly seizure frequency declined by 68% (p less than 0.05, Wilcoxon matched-pairs test) in a 3-month treatment period compared with the 3 months prior to therapy, and six of the eight women had fewer seizures. None experienced more seizures or disruption of menses. Transient tiredness and depression were noted in some when progesterone dosage was raised above minimally effective levels. These symptoms cleared within 48 hours of lowering the dosage. The value of intermittent natural progesterone therapy as a safe, well-tolerated, and effective adjunct to antiseizure therapy should be assessed further.
Solution:
Administration, Intravaginal