instruction:
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.
question:
Abstract: Two cases of osteochondritis dissecans of the talar dome treated by closed percutaneous drilling are presented to illustrate a procedure for high-risk patients. The operation is performed with the aid of an image intensifier. The ostoechondral fragment is percutaneously drilled to avoid open operation and osteotomizing the medial malleolus.
answer:
Adolescence

question:
Abstract: To investigate the mechanism of ventricular arrhythmias induced by epinephrine in dogs with hypokalemia, 30 adult mongrel dogs were separated into a control group (n = 13) and a hypokalemia group (n = 17). In the hypokalemia group, sodium polystyrene sulfonate (5 g/kg body weight) was infused into the colon. In both groups, the serum concentrations of sodium, potassium and calcium were measured every 15 minutes for 60 minutes. The mean (+/- standard deviation) serum potassium level of the hypokalemia group decreased significantly from 3.81 +/- 0.21 to 2.92 +/- 0.36 mEq/liter; there were no significant changes in other electrolytes. After 60 minutes, epinephrine (10 micrograms/kg) was injected intravenously in the hypokalemia and control groups, and the arrhythmia ratio (the number of ventricular ectopic beats divided by the total heart rate) was calculated for 5 minutes. Each group was further classified into subgroups of dogs with an arrhythmia ratio higher or lower than 10%. An arrhythmia ratio over 10% was observed in 7.7% of the control group and 53% of the hypokalemia group. Immediately after 5 minutes of epinephrine injection, myocardial mitochondria and plasma membrane fraction were prepared from each group. Mitochondrial calcium content and phospholipase activity of plasma membrane fraction were determined. Significant increases in both mitochondrial calcium content and phospholipase activity were observed in the dogs with hypokalemia and an arrhythmia ratio greater than 10%.(ABSTRACT TRUNCATED AT 250 WORDS)
answer:
Animal

question:
Abstract: A case of a cavernous angioma of the cauda equina is presented. The patient was a 28-year-old man who experienced sudden low-back pain and headache without neurological symptoms. Lumbar puncture revealed subarachnoid hemorrhage. He had suffered a similar episode 3 years previously. Selective spinal angiography did not demonstrate any abnormal vascularity. Metrizamide myelography and magnetic resonance imaging were useful in demonstrating the presence of a tumor. Laminectomy at L1-3 and total removal of the tumor were performed without neurological deficit.
answer:
Adult