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Biomedical subjects

L A Schwartz

Publications and source records attributed to L A Schwartz.

11 recordsLinked to original sources
PubMed1999

An outbreak of acute respiratory disease caused by Mycoplasma pneumoniae and adenovirus at a federal service training academy: new implications from an old scenario.

Outbreaks of Mycoplasma pneumoniae and adenovirus have been reported in military institutions for several decades. During a recent outbreak in a federal service training academy, we performed an epidemiological and laboratory investigation to better characterize and control the outbreak. Of 586 students responding to a questionnaire, 317 (54%) reported having a respiratory illness during the outbreak period. Among 42 students who underwent complete laboratory testing, 24 (57%) had evidence of M. pneumoniae infection, 8 (19%) had evidence of adenovirus infection, and 4 (10%) had evidence of both. Polymerase chain reaction testing of oropharyngeal swabs revealed more acute M. pneumoniae infections (57% positive) than did serology or culture. Multivariate analysis revealed that visiting the campus health clinic >3 times for a nonrespiratory condition, such as injury, was a significant risk factor for illness among freshmen early in the course of the outbreak, whereas having an ill roommate was a risk factor throughout the duration of the outbreak.

Acute Disease↗
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↗
PubMed1984

Subjective and objective features of sore throat.

This study examines the relationship between the symptom of sore throat and the signs of pharyngitis. Patients seeking medical attention for sore throat were examined by their physician, who documented findings on a Tonsillopharyngitis Score (TPS) and obtained a throat culture. Each patient was then instructed by the physician's assistant to characterize the severity of throat pain on a Sore Throat Pain Intensity Scale (STPIS) and Sore Throat Questionnaire. A high positive correlation was found for the STPIS and TPS but not for these findings and the cause of pharyngitis. A similar association was found between the relative severity of throat pain and the words patients use to describe it. This new method objectively confirms the subjective rating of sore throat pain.

Adolescent↗
PubMedDate not supplied

The efficacy and safety of once-daily nifedipine: the coat-core formulation compared with the gastrointestinal therapeutic system formulation in patients with mild-to-moderate diastolic hypertension. Nifedipine Study Group.

The efficacy and safety of two sustained-release formulations of nifedipine, the coat-core system (NIF CC) and the gastrointestinal therapeutic system (NIF GITS), were examined in 228 patients with mild-to-moderate essential hypertension in this 16-week, multicenter, randomized, double-blind study. The coadministration of food affects the nifedipine pharmacokinetics with differing magnitudes for the two formulations. To evaluate drug safety under the most rigorous circumstances, all medication was given with food. After a 4-week placebo lead-in period, eligible patients were randomized to a parallel-group treatment period of either NIF CC or NIF GITS. 30 mg daily with food for 4 weeks, followed by forced titration to nifedipine 60 mg daily for an additional 4 weeks. For the final 4-week period, half of the patients receiving each formulation were switched to the alternate formulation at a dose of 60 mg daily. Within treatment groups, all four blood pressure variables (systolic and diastolic measurements for both trough and 24-hour periods) demonstrated significant reductions (P < 0.05) from baseline (established after the placebo lead-in period) for both formulations at every subsequent visit and end point. When comparing the two formulations, the mean change from baseline in 24-hour systolic and diastolic blood pressure measurements, determined by using ambulatory monitoring, was not statistically different for both doses (P > 0.05). The mean change in trough blood pressure from baseline during the parallel-group treatment period was statistically significant in favor of NIF GITS for both the 30-mg and 60-mg doses (P < 0.05). The treatment-emergent adverse-event rates for both formulations were similar during the parallel-group period, with the exception of dizziness, which was higher for patients receiving NIF CC. Both formulations were well tolerated and reduced blood pressure over the 24-hour dosing interval even when coadministered with food. When half of the patients receiving NIF GITS 60 mg daily were randomly crossed over to NIF CC 60 mg daily, there were no significant changes in either the trough or 24-hour mean blood pressure measurements (P > 0.05), adverse events, or dropout rates. When patients receiving NIF CC 60 mg were crossed over to NIF GITS 60 mg daily, they exhibited no significant change in diastolic blood pressure (P > 0.05). This study demonstrated that when given with food, both NIF CC and NIF GITS reduce 24-hour mean blood pressure measurements similarly.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMedDate not supplied

The efficacy and safety of once-daily nifedipine administered without food: the coat-core formulation compared with the gastrointestinal therapeutic system formulation in patients with mild-to-moderate hypertension. Nifedipine Study Group.

A parallel-group, randomized, double-blind, forced-titration, multicenter study was done to compare the efficacy and safety of once-daily nifedipine coat-core (NIF CC) and once-daily nifedipine gastrointestinal therapeutic system (NIF GITS) dosed in the fasting state in patients with mild-to-moderate essential hypertension. Both formulations have been shown to effectively and safely lower blood pressure in placebo-controlled trials. After a 4-week placebo run-in period, 228 patients were randomized to 4 weeks of treatment with either NIF CC 30 mg daily or NIF GITS 30 mg daily. This period was followed by a forced-titration period to nifedipine 60 mg daily for an additional 4 weeks of double-blind therapy. After the 30-mg treatment period (the primary time point), there were no statistically significant differences between treatment groups in mean change from baseline in trough supine diastolic blood pressure, the primary efficacy variable (NIF CC patients, -7.0 mm Hg; NIF GITS patients, -8.4 mm Hg; P = 0.139). Also, because the upper bound of the treatment difference confidence interval was < 3.0 mm Hg, equivalence--as defined in the protocol--was established. After the 60-mg treatment period, the change from baseline in trough supine diastolic blood pressure was significantly greater for patients treated with NIF GITS than for patients treated with NIF CC (NIF GITS patients, -12.0 mm Hg; NIF CC patients, -8.4 mm Hg; P < 0.001). Because the upper bound of the confidence interval was > 3 mm Hg, equivalence cannot be claimed. No statistically significant differences were noted for the comparison of mean 24-hour ambulatory blood pressure monitoring changes. Both formulations were well tolerated.

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↗