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: The clinical, therapeutic, and histological features of 54 patients with medulloblastoma were analyzed retrospectively by a multivariate approach with regard to prognosis. The overall 5-year survival rate was 60%, with 48% of patients free of recurrence at 5 years. Cell differentiation, when present, was associated with a significantly longer recurrence-free period. Seventy-two percent of patients with the histological finding of cell differentiation were recurrence-free at 5 years. A marginally significant increase in the 5-year survival rate was also seen in association with differentiation. Only 34% of the patients whose tumor exhibited necrosis were alive at 5 years. There was no statistically significant difference in 5-year survival for children under 3 years of age or for the group of children aged 5 years or under. However, a significantly larger fraction (72%) of the group aged 5 years or under had a recurrence-free period of 5 years or more. Other factors including sex, extent of surgical resection. Chang tumor stage, posterior fossa radiation dose, and adjuvant chemotherapy did not influence prognosis.

Ex Output:
Adolescence

Ex Input:
Abstract: Twelve patients with intractable rheumatoid arthritis were treated with antilymphocyte globulin (ALG), prednisolone and a cytotoxic agent, usually azathioprine, and were followed for 1 year. There was a significant (p less than 0.05) improvement in the mean score for early-morning stiffness, grip strength and the severity of nodules and vasculitis at 6 weeks and 3 months when compared to the initial visit. However, in most patients, this benefit was not sustained despite continued cytotoxic and steroid therapy. A rise in the haemoglobin and fall in ESR was maintained throughout the study period.

Ex Output:
Antilymphocyte Serum

Ex Input:
Abstract: Quantitative evaluation of stainable bone aluminum and measurement of bone aluminum content were done in 55 patients on chronic maintenance dialysis. All patients underwent bone biopsies. Histomorphometry of static and dynamic parameters of bone structure, bone formation and resorption, and quantitation of stainable bone aluminum at the osteoid-bone interface were performed. In addition, bone aluminum content was measured by atomic absorption spectrophotometry. Bone aluminum content was elevated in all patients (81 +/- 9.6 vs. 18 +/- 6 micrograms/g dry wt) and stainable aluminum was found in 47% of them. All patients with predominant low-turnover osteomalacia or adynamic bone disease displayed stainable bone aluminum. In contrast, stainable bone aluminum was not present in individuals with predominant-hyperparathyroid bone disease. Patients with stainable aluminum had lower bone mass (P less than 0.05), higher volume and surface of lamellar osteoid (P less than 0.01), less volume and surface of woven osteoid (P less than 0.05 and P less than 0.01), lower osteoblastic and osteoclastic indices (P less than 0.01), less doubly labelled osteoid seams, lower mineral apposition rate and lower bone formation rates (P less than 0.05 to P less than 0.01). Stainable aluminum correlated with volume of lamellar osteoid and cellular parameters of bone formation and resorption, mineral apposition rate, and bone formation rates (P less than 0.05 to P less than 0.001). In contrast, bone aluminum content correlated with volume of lamellar osteoid only (P less than 0.001). These findings indicate that stainable aluminum at the mineralization front and not aluminum content of bone reflects the histopathologic changes found in bone of dialyzed patients.

Ex Output:
Adult