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.

Input: Consider Input: Abstract: Previous investigation in normal humans has demonstrated reduced ventilation and ventilatory responses to chemical stimuli during sleep. Most have interpreted this to be a product of decreasing central nervous system sensitivity to the normal stimuli that maintain ventilation, whereas other factors such as increasing airflow resistance could also contribute to this reduction in respiration. To improve our understanding of these events, we measured ventilation and occlusion pressures (P0.1) during unstimulated ventilation and rebreathing-induced hypercapnia during wakefulness and non-rapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep. Eighteen subjects (10 males and 8 females) of whom seven were snorers (5 males and 2 females) were studied. Ventilation was reduced during both NREM and REM sleep (P less than 0.05), but this decrement in minute ventilation tended to be greater in snorers than nonsnorers. Unstimulated P0.1, on the other hand, was maintained or increased during sleep in all groups studied, with males and snorers showing the largest increase. The hypercapnic ventilatory response fell during both NREM and REM sleep and tended to be lower during REM than NREM sleep. However, the P0.1 response to hypercapnia during NREM sleep was well maintained at the waking level although the REM response was statistically reduced. These studies suggest that the mechanism of the reduction in ventilation and the hypercapnic ventilatory response seen during sleep, particularly NREM sleep, is likely to be multifactorial and not totally a product of decreasing central respiratory drive.

Output: Adult


Input: Consider Input: Abstract: To investigate the effect of interictal epileptiform discharges (IEDs) on plasma prolactin (PRL) level, we studied 18 epileptic patients with complex partial seizures (CPS) who did not experience clinical or subclinical ictal events during all-night monitoring with polygraphic recording and video imaging. The density of IEDs peaked during non-REM stages and was significantly reduced during REM stage. Mean plasma PRL concentrations in epileptic patients, when sampled at 30-min intervals, showed a moderate but significant elevation during non-REM (p less than 0.001) and awake stages (p less than 0.005), but not during REM stage, when compared with 10 nonepileptic control subjects studied in a similar fashion. The data obtained in this physiologically controlled environment indicate that the cumulative effect of IEDs may modify PRL regulatory mechanisms, resulting in a modest elevation of plasma concentrations independent of ictal discharges.

Output: Adult


Input: Consider Input: Abstract: Cells with mutations at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus may be detected in vitro by their resistance to the toxic effects of thioguanine. We have assessed HPRT mutants in peripheral blood lymphocytes of patients with connective tissue diseases who have been treated for long periods with cytotoxic drugs. The results from patients treated with cyclophosphamide were abnormal suggesting the presence of drug-induced mutations. The results from patients treated with chlorambucil or azathioprine did not differ from controls--either these drugs have not induced mutations or, more likely, the technique is not sufficiently sensitive to detect them. These possibilities are discussed. Specific mutations induced by cytotoxic drugs in patients with connective tissue diseases have not been previously recorded.


Output: Azathioprine


