TASK DEFINITION: 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.
PROBLEM: Abstract: Five children, aged 6 to 16 years, were tested for unilateral discrimination and interhemispheric transfer of tactile information as well as tactuomotor learning at various intervals before and after therapeutic callosotomy. Comparison of preoperative and postoperative capacities revealed that younger children are considerably less affected by the interruption of callosal transmission than older children. Bilateral organization of speech and participation of the anterior commissure can largely be excluded as possible compensatory mechanisms. The most plausible explanation for the excellent preservation of interhemispheric integration of tactile functions in the younger patients appears to be continued reliance on ipsilateral pathways. The relatively greater deficits observed in the older children, on the other hand, suggest that sensorimotor functions come to depend more extensively on contralateral pathways as the corpus callosum reaches functional maturity.

SOLUTION: Adolescence

PROBLEM: Abstract: Methylglyoxal bis (guanylhydrazone) (MGBG) is an inhibitor of polyamine synthesis. In vitro studies demonstrate the accumulation of some tumor cells in S and G2 phases of the cell cycle. Nineteen patients with advanced head and neck cancer were entered in a Phase II trial of MGBG. MGBG, 500 mg/M2, was administered as a brief intravenous infusion weekly for 4 weeks, then every 2 weeks. Dose modifications were based on cumulative toxicity after 2 weekly treatments. All but three patients had prior exposure to chemotherapy for disease recurrence. Of 17 patients evaluable for response and toxicity, one brief partial response was observed. The most common toxicities were mild to moderate nausea, vomiting, diarrhea, and stomatitis. Myelosuppression occurred in three patients. Dose modifications were required in four patients; a maximum dose of 700 mg/M2 was tolerated. The results of four other Phase II single and combination chemotherapy trials of MGBG in head and neck cancer are reviewed. The single agent response rate in 59 patients was 22% (range, 6%-41%). The poor response rate observed in this trial was similar to that in other trials in which a heavily pretreated group of patients was evaluated. It is concluded that single agent MGBG is not a useful drug in heavily pretreated recurrent disease patients. However, because of its biochemical effects, further testing in combination with cycle specific agents and in larger numbers of patients with minimal prior treatment may be warranted.

SOLUTION: Aged

PROBLEM: Abstract: Seven dog lower left lung lobes were statically inflated and perfused at a constant rate for each lobe with a perfusate in which the hematocrit was altered over a wide range. The permeability-surface area of urea was calculated from multiple indicator dilution curves using two separate injectates for each hematocrit level. One injectate contained only 125I-albumin as the vascular reference tracer and the other contained both 51Cr-erythrocytes and 125I-albumin as the vascular reference tracers; both contained [14C]urea as the permeating tracer. The results strongly indicate that the phenomenon of "erythrocyte trapping" of urea does not affect the calculation of urea permeability-surface area product provided the appropriate albumin-erythrocyte composite reference tracer is utilized in its calculation.

SOLUTION:
Animal