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.

[Q]: Abstract: The capacity to absorb fructose in 10 healthy adults was investigated by means of hydrogen breath analysis. Fructose absorption was quantified with lactulose standards. Significant hydrogen production (greater than or equal to 20 ppm rise of breath hydrogen) was found after challenge with 10% solutions of 50, 37.5, 25, 20, and 15 g fructose in eight, seven, five, four and one subjects, respectively. One subject showed malabsorption after a 10 g dose and possibly also 5 g fructose. In contrast, no malabsorption could be detected in any of the 10 subjects after ingestion of 100 g, 75 g, or 50 g sucrose or a mixture of 50 g glucose and 50 g fructose. After ingestion of mixtures of 50 g fructose +25 g glucose and 50 g fructose +12.5 g glucose malabsorption was present in three and seven subjects, respectively. Symptoms during all challenges were mild, or absent. It is concluded that in the healthy state the absorption capacity of fructose given alone ranges from less than 5 g to more than 50 g. The absorption capacity of fructose given as sucrose is much higher. Glucose stimulates fructose uptake in a dose dependent fashion. The possible existence of more than one intestinal transport system for fructose is considered. The elucidation of the clinical relevance of the findings is important.
[A]: Adult

[Q]: Abstract: Results from studies of twin concordance in multiple sclerosis have not conclusively differentiated between environmental and genetic factors that determine susceptibility to the disease. Published studies that have been based on case finding by public appeal have been characterized by difficulties in ascertainment. The data reported here are from a large population-based study of multiple sclerosis in twins, in which ascertainment has been relatively unbiased and the cooperation of patients nearly complete. A total of 5463 patients attending 10 multiple sclerosis clinics across Canada were surveyed. Twenty-seven monozygotic and 43 dizygotic twin pairs were identified, and the diagnosis of multiple sclerosis was verified by examination and laboratory investigation. Seven of 27 monozygotic pairs (25.9 percent) and 1 of 43 dizygotic pairs (2.3 percent) were concordant for multiple sclerosis. The concordance rate for 4582 nontwin siblings of patients at two multiple sclerosis clinics was 1.9 percent, closely paralleling the concordance rate in dizygotic twins. To the extent that the difference in concordance rates between monozygotic and dizygotic twins indicates genetic susceptibility, the results of this study show a major genetic component in susceptibility to multiple sclerosis.
[A]: Canada

[Q]: Abstract: In reconstructing the anterior cruciate ligament (ACL) it is important to place the inner ends of the drill channels correctly, to get the ACL into an isometric position. Anatomic studies demonstrate the value of a modified surgical technique using a special drill guide for standardized positioning of the anterior cruciate substitute. The drill guide consists of a metal frame with one adjustable and one fixed guide tube. Drilling is done from the anteromedial aspect of the tibia, upwards, through the joint space and the femur in a straight line, both channels being drilled in a single procedure. The precision of guided drilling was superior to that of free-hand drilling in positioning the ligament in the correct anatomic place.
[A]:
Adult