Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Q: Abstract: Decreased maximal O2 uptake (VO2max) and stimulation of the sympathetic nervous system have been previously shown to occur at high altitude. We hypothesized that tachycardia mediated by beta-adrenergic stimulation acted to defend VO2max at high altitude. Propranolol treatment beginning before high-altitude (4,300 m) ascent reduced heart rate during maximal and submaximal exercise in six healthy men treated with propranolol (80 mg three times daily) compared with five healthy subjects receiving placebo (lactose). Compared with sea-level values, the VO2max fell on day 2 at high altitude, but the magnitude of fall was similar in the placebo and propranolol treatment groups (26 +/- 6 vs. 32 +/- 5%, P = NS) and VO2max remained similar at high altitude in both groups once treatment was discontinued. During 30 min of submaximal (80% of VO2max) exercise, propranolol-treated subjects maintained O2 uptake levels that were as large as those in placebo subjects. The maintenance of maximal or submaximal levels of O2 uptake in propranolol-treated subjects at 4,300 m could not be attributed to increased minute ventilation, arterial O2 saturation, or hemoglobin concentration. Rather, it appeared that propranolol-treated subjects maintained O2 uptake by transporting a greater proportion of the O2 uptake with each heartbeat. Thus, contrary to our hypothesis, beta-adrenergic blockade did not impair maximal or submaximal O2 uptake at high altitude due perhaps to compensatory mechanisms acting to maintain stroke volume and cardiac output.

A: Propranolol does not impair exercise oxygen uptake in normal men at high altitude.
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Q: Abstract: The effects of cimetidine on the healing and recurrence of duodenal ulcers and gastric ulcers were compared. The extent of the acid secreting areas was examined by the endoscopic Congo red methylene blue test. Using the extent of acid secreting areas gastric ulcers were classified into ulcers with and without extensive acid secreting areas. Duodenal ulcers were all associated with extensive acid secreting areas. The gastric acid outputs in the basal state and after maximal stimulation with gastrin were highest in duodenal ulcers, and lowest in gastric ulcers without extensive acid secreting areas. Cimetidine treatment significantly promoted the healing of duodenal ulcers and gastric ulcers with extensive acid secreting areas when compared with placebo, but not of the gastric ulcers without extensive acid secreting areas. Cimetidine also significantly diminished the recurrence of duodenal ulcers, but not gastric ulcers with and without extensive acid secreting areas. These findings indicate that in Japan cimetidine promotes the healing of duodenal and gastric ulcers associated with high gastric acid production and prevents recurrence of duodenal ulcers, but has little or no influence on the healing and recurrence of gastric ulcers associated with low acid secretion.

A: Effects of cimetidine on the healing and recurrence of duodenal ulcers and gastric ulcers.
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Q: Abstract: Abnormalities of coagulation and fibrinolysis in 12 head-injured patients were studied in early (within 24 hours of onset) and late (10th to 17th day after onset) stages. alpha 2 Plasmin inhibitor (alpha 2PI), antithrombin III (ATIII), and fibrinopeptide A (FPA) and B beta 15-42 (FPB beta) were measured in particular, in addition to the usual tests (platelet count (PLT), prothrombin time (PT), partial thromboplastin time, fibrinogen, and fibrin/fibrinogen degradation products (FDP)). alpha 2PI was abnormally lower, and FPA and FPB beta were much higher; fibrinogen and ATIII were moderately lower in the early stage than in the late stage in 6 head-injured patients with postoperative intracranial hemorrhage. alpha 2PI, ATIII, and fibrinogen were moderately lower and FPA was moderately higher in the early stage than in the late stage in 6 head-injured patients without postoperative intracranial hemorrhage. PLT and fibrinogen were lower, alpha 2PI was much lower, and FPA was much higher in the 6 patients with postoperative intracranial hemorrhage than in the 6 patients without postoperative intracranial hemorrhage. One patient with acute epidural and subdural hematomas had recurrent postoperative intracerebral hematoma twice. This recurrent hemorrhage was due to disseminated intravascular coagulation (DIC) caused by primary brain damage and was associated with extremely high FPA and FPB beta levels and abnormally low alpha 2PI and PLT. Fresh-frozen plasma and intravenous low-dose heparin were administered after the two recurrent hemorrhages, after which FPA and FPB beta normalized immediately, although other screening tests showed only gradual improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

A:
Relationship between abnormalities of coagulation and fibrinolysis and postoperative intracranial hemorrhage in head injury.
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