Aftereffects of Cognitively Demanding Acute Aerobic Exercise on Working Memory.

PURPOSE: This study examined the aftereffects of cognitively demanding acute aerobic exercise on working memory in middle-age individuals. METHODS: In a within-participants design, middle-age males (n = 28) performed a two-back task to assess working memory before, immediately after, and 30 min after the following three interventions: 1) a rest-cognition intervention, in which they performed a cognitive task on a cycle ergometer without exercising; 2) an exercise-cognition intervention, in which they simultaneously exercised on a cycle ergometer and performed a cognitive task; and 3) an exercise-only intervention, in which they only exercised on a cycle ergometer. RESULTS: The exercise-only intervention resulted in increased hit rate and decreased reaction times and intraindividual variability on correct rejection trials, suggesting that simple aerobic exercise had a beneficial impact on working memory. By contrast, the exercise-cognition intervention resulted in increased intraindividual variability on correct rejection trials, which is suggestive of cognitive fatigue resulting from the additional cognitive demands. Such a decline was not observed even in the rest-cognition condition. CONCLUSIONS: Cognitive fatigue caused by additional cognitive demands during aerobic exercise may cancel beneficial postexercise effects on working memory. Cognitively demanding acute aerobic exercise appears to be less effective than simple aerobic exercise in improving executive function.

[Severe hypotension and ventricular fibrillation during combined general and epidural anesthesia in a patient on major tranquilizers].

A 54-year-old man (height 155 cm, weight 49 kg) was scheduled for retroperitoneoscopic nephrectomy. He had a history of schizophrenia that had been controlled with propericiazine 10 mg and bromperidol 3 mg daily for 34 years. After induction of anesthesia, 1% mepivacaine 5 ml was administered via an epidural catheter. Blood pressure decreased 15 minutes later to 47/25 mmHg and heart rate dropped to 50 beats x min(-1). Ventricular fibrillation occurred despite titrated injection of ephedrine (40 mg total), phenylephrine (1 mg total), atropine (0.5 mg total), and rapid infusion of crystalloid and colloid solutions. Chest compression and defibrillation were required to restore spontaneous circulation. Surgery was cancelled and he was extubated 45 minutes later without any complications. These findings suggest that caution must be exercised when combining general and epidural anesthesia for patients on long-term major tranquilizers. In the event of refractory hypotension, the use of direct-acting vasoconstrictors such as noradrenaline or vasopressin should be considered.

[A randomized controlled trial of postoperative adjuvant chemotherapy for colorectal cancer-optimal duration of the treatment].

METHODS: Subjects were 239 patients with colorectal cancer who underwent curative resection surgery from December 1994 to March 1997(Stage I-III b). The patients were given 5'-DFUR for postoperative 10 months as scheduled. They had been allocated into either a 1-year group or a 3-year group by dynamic randomization. 5'-DFUR was administered by an intermittent regimen such as 1,200 mg/body/day for five days followed by two days rest. All patients were followed for five years at least. RESULTS: 239 patients were enrolled in the study. Favorable prognoses in both groups were observed. Although no statistically significant differences in overall survival curves of full analysis set based on the drug administration durations, were detected(log-rank test, p=0.734), a better prognosis was found in the 3-year group(5-year OS: 92.0%; 1- year group, 91.4%; 3-year group). Adverse drug reactions resulted in low rates such as 14.8% in the 1-year group and 19.5% in the 3-year group. Grade 3 was found in either group. CONCLUSIONS: Due to a result in the present study that 5-year survival rates in both groups were far higher than anticipated, we could not finally clarify the optimal administration duration of 5'-DFUR. However, the results of the present study indicate that 5'-DFUR results in a good prognosis for colorectal cancer patients and is safe over a long / administration period.