instruction:
Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).
question:
Abstract: Methotrexate (MTX) appears to be useful in patients with rheumatoid arthritis (RA) refractory to other drugs but its long-term toxicity and efficacy are uncertain. A retrospective study of MTX in such patients in comparison with the purine analogues, azathioprine and 6-mercaptopurine was made using life-table analysis. Eighty-four patients took MTX in a median dose of 7.5 mg/week whilst 55 received purine analogues, 100 mg/day (median). By 12 months, 19.3% of patients had ceased MTX due to toxicity, compared with 29.3% for purine analogues. Toxicity severe enough to warrant stopping therapy was uncommon after 8 months with either drug. At 12 months 61.5% of the MTX patients had achieved defined criteria of improvement compared with 25.6% for the purine analogues (p less than 0.05). The number of patients improving on purine analogues did not increase substantially after 6 months, whereas the number improving with MTX continued to 12 months. MTX in a low-dose regimen is useful in refractory RA and superior to low-dose purine analogues.
Which is the apt title for the abstract? option1: Comparison of methotrexate with azathioprine or 6-mercaptopurine in refractory rheumatoid arthritis: a life-table analysis. option2: Myocyte cell loss and myocyte hypertrophy in the aging rat heart.
answer:
Comparison of methotrexate with azathioprine or 6-mercaptopurine in refractory rheumatoid arthritis: a life-table analysis.

question:
Abstract: Daily human energy requirements calculated from separate components of energy expenditure are inaccurate and usually in poor agreement with measured energy intakes. Measurement of energy expenditure over periods of 24 h or longer is needed to determine more accurately rates of daily energy expenditure in humans. We provide a detailed description of a human respiratory chamber and methods used to determine rates of energy expenditure over 24-h periods in 177 subjects. The results show that: fat-free mass (FFM) as estimated by densitometry is the best available determinant of 24-h energy expenditures (24EE) and explains 81% of the variance observed between individuals (24EE [kcal/d] = 597 + 26.5 FFM); 24EE in an individual is very reproducible (coefficient of variation = 2.4%); and even when adjusted for differences in FFM, there is still considerable interperson variability of the daily energy expenditure. A large portion of the variability of 24EE among individuals, independent of differences in body size, was due to variability in the degree of spontaneous physical activity, i.e., "fidgeting," which accounted for 100-800 kcal/d in these subjects.
Which is the apt title for the abstract? option1: Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory chamber. option2: Hematologic data in the case records [letter]
answer:
Determinants of 24-hour energy expenditure in man. Methods and results using a respiratory chamber.

question:
Abstract: The nosologic distinction between paramyotonia congenita and hyperkalemic periodic paralysis is somewhat blurred. Muscle membrane inexcitability induced by cooling seems to be characteristic of paramyotonia congenita. The effect of cooling on the maximal compound muscle action potential (CMAP) in patients with paramyotonia congenita was compared to that in patients with hyperkalemic periodic paralysis. Diminution in CMAP amplitude and area, which was observed in paramyotonia congenita, did not occur in hyperkalemic periodic paralysis. We suggest that this effect of cooling on the CMAP can be utilized in the differentiation of these two syndromes.
Which is the apt title for the abstract? option1: Lack of cold sensitivity in hyperkalemic periodic paralysis. option2: Optimal pulse sequence for imaging hepatic metastases.
answer:
Lack of cold sensitivity in hyperkalemic periodic paralysis.