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Biomedical subjects

L A Schwartz

Publications and source records attributed to L A Schwartz.

6 recordsLinked to original sources
PubMed1988

Glucose sham drinking in the rat: satiety for the sweet taste without the sweet taste.

In rats sham drinking through oesophageal fistulae, sham intake of a dilute glucose solution (0.25 M) is greatly reduced, but not abolished, by an intragastric water preload. Since no further fluid enters the body, the early cessation of sham drinking must reflect a purely oral control, set by hydrational status. We show that lapping after the water load is abolished if the rat has sham-drunk appreciable quantities before the load is delivered. This is true even if the initial sham drinking is of plain water, with no sweet taste. Therefore, (1) the effect of the preload is to set the total quantity of oral feedback required to end the sham drinking bout; and (2) the necessary oral feedback is provided by the lapping response itself. It does not depend upon gustation.

Animals↗
PubMed1987

Similar efficacy of nitrendipine in young and elderly hypertensive patients.

Calcium channel blockers have been postulated to be more effective as monotherapeutic antihypertensive agents in the elderly than in younger patients. To determine if a new dihydropyridine derivative, nitrendipine, is more effective in the elderly (older than 60 years) than in younger hypertensive subjects (younger than 60 years), nitrendipine was administered in a multicentered study to 21 elderly and 33 younger subjects with essential hypertension. After gradual discontinuation of previous antihypertensive therapy and 2 weeks of placebo, the daily dose of nitrendipine (10 to 40 mg) was titrated over 3 weeks to achieve a 10 mm Hg decrease in supine diastolic blood pressure (BP) for patients entering with 90 to 99 mm Hg. For patients entering with at least 100 mm Hg, the dose was titrated to diastolic BP no greater than 90 mm Hg. Titrated dose of nitrendipine was maintained for 4 additional weeks. Propranolol was added for "symptomatic" tachycardia. Nitrendipine reduced BP in 90% of patients completing all phases of the study (n = 49). The proportion of responders was 47% among the elderly and 44% among young subjects. Change in heart rate was similar in both groups (-0.1 +/- 9.9 and +2.9 +/- 8.8 beats/min, mean +/- standard deviation). Two elderly and 1 younger subject required addition of propranolol (difference not significant). There was no correlation between the age of patients and changes in supine systolic and diastolic BP or heart rate (r = 0.21, -0.15 and -0.21, respectively). Adverse effects occurred with equal frequency in older and younger subjects (19 of 21 vs 23 of 33 patients, difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Narcotics decrease heart rate during inhalational anesthesia.

We determined the heart rate (HR) response to enflurane, halothane, and isoflurane and the effects of narcotics on this response in 81 healthy patients scheduled for elective surgery. Patients were randomly assigned to one of six treatment groups: one of the three anesthetics (approximately 0.9 MAC) in 60% nitrous oxide, and either 0.15 mg/kg of intramuscular morphine 30-60 min before induction or 1 microgram/kg of IV fentanyl 10 min after skin incision. All patients received diazepam, 10 mg orally, 60-90 min before anesthesia, a rapid sequence intravenous induction, and mechanically controlled ventilation. During inhalational anesthesia and the first 10 min of surgery, no significant change in HR occurred in any group (compared to the preinduction HR), although patients given morphine premedication tended to have a decreased HR and those not given morphine premedication tended to have an increased HR. These trends partially account for significant differences that emerged between groups after induction of anesthesia. Patients given morphine premedication and halothane had lower HR (64 +/- 3 SEM) than patients given isoflurane (80 +/- 3) or enflurane (84 +/- 3) and no morphine premedication. Patients anesthetized with enflurane and morphine premedication had lower HR (71 +/- 3) than patients given enflurane without morphine premedication. Administration of fentanyl 10 min after incision (these patients had received no morphine) significantly decreased HR in the presence of any of the vapors. We conclude that inhalational anesthetics used in the clinical setting we employed do not significantly increase heart rate, and that prior administration of morphine or concurrent administration of fentanyl may significantly decrease HR.

Adult↗
PubMedDate not supplied

Phase I trial of ftorafur combined with mitomycin C or methyl-CCNU in gastrointestinal cancers.

Twenty-five patients with disseminated gastrointestinal malignancies were treated in a phase I study with a combination of ftorafur and mitomycin C or florafur and methyl-CCNU. Most patients had been heavily treated previously. Gastrointestinal, central nervous system, and marrow toxicity were manageable. Tumor regression was noted in five of 25 patients. A large-scale phase II study in untreated patients with gastrointestinal malignancies appears indicated with a combination of these agents.

Adenocarcinoma↗