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.

Ex Input:
Abstract: To determine whether sensitivity of muscle characteristics and aerobic performances to endurance training was genotype-dependent, 6 pairs of monozygotic (MZ) twins, 21 +/- 4 yr of age (mean +/- SD), took part in a 15-wk ergocycle endurance training program. Tests were performed before and after 7 and 15 weeks of training. A biopsy of the vastus lateralis muscle was obtained for the determination of fiber type composition and activities of creatine kinase, hexokinase, phosphofructokinase, lactate dehydrogenase, malate dehydrogenase, 3-hydroxyacyl CoA dehydrogenase, and oxoglutarate dehydrogenase. Maximal oxygen uptake was measured with a progressive maximal ergocycle test, while endurance performance was determined as the total work output during a 90-min maximal ergocycle test. Results indicated that maximal oxygen uptake X kg-1 and endurance performance X kg-1 increased significantly (14 and 31%, respectively) with training, and intra-pair resemblance (intra-class) in response to 15 wk of training ranged from 0.65 to 0.83. Hexokinase (31%), phosphofructokinase (37%), lactate dehydrogenase (21%), malate dehydrogenase (31%), and 3-hydroxyacyl CoA dehydrogenase (60%) were significantly increased with training whereas no mean change in fiber-type proportions, oxoglutarate dehydrogenase and creatine kinase activities and the phosphofructokinase/oxoglutarate dehydrogenase ratio was observed. Similarity within twin pairs in the response to enzyme activities was mainly detected in the second half of the training program. The present results confirm, therefore, that both maximal oxygen uptake and endurance performance responses to training are largely genotype-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Ex Output:
Adaptation, Physiological

Ex Input:
Abstract: In order to perform quantitative in vitro and clinical studies on the removal of Al by the combined therapy of DFO administration and HD, an HPLC system for measuring DFO was established and a leaky membrane with enhanced permeability to middle molecular substances was developed. The DFO infusion caused rises in plasma Al levels (regarded as indicating the elution of accumulated Al) in patients undergoing HD. Plasma levels increased most in long-term patients and those with bone pain. Examination of Al clearances demonstrated that this increased plasma Al content passed through HD membranes at levels of more than 80 micrograms/l, and that the leaky membrane was more effective for removal of Al as well as DFO than the conventional one. Although a 1:1 complex between DFO and Al in an aqueous solution was confirmed, the formation of Al-rich complexes in vivo was suggested. It is concluded that Al-DFO complex formed in vivo can be effectively removed across the leaky membrane.

Ex Output:
Aluminum

Ex Input:
Abstract: Cow snout epidermal cells digested by 0.25% trypsin were separated into three regions of keratinocytes by Percoll density gradient centrifugation. The membrane fluidity of keratinocytes in each region was measured by electron spin resonance using 5-doxyl stearic acid (5-DSA) as a labeling agent. The order parameter(s) showed higher values as the depth of the epidermis decreased: lower region of epidermis, 0.632; upper region, 0.645; and horny cells, 0.680. These data indicated that membrane fluidity of epidermal cells decreased as cells approached the surface.

Ex Output:
Animal