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Biomedical subjects

D Tepper

Publications and source records attributed to D Tepper.

25 records · Page 2Linked to original sources
PubMed1985

Size and shape of enzymatically isolated ventricular myocytes from rats and cardiomyopathic hamsters.

Rod-shaped and branched ventricular myocytes from rats and cardiomyopathic hamsters (strain 53.58) were isolated enzymatically, and their widths and lengths were measured in physiological salt solutions containing normal levels of calcium (2.5 mmol). In rats of approximately 200 g body weight, the average myocyte width and length are 25 micron and 115 micron. The isolated cells are also classified according to shape with nearly 50% branched or otherwise irregular. Myocytes of the hearts of the 53.58 strain of cardiomyopathic hamsters at 7 months of age are significantly larger than control hamsters of the same age, indicating that cellular hypertrophy has occurred. Estimates of the number of cells in the ventricles indicate that there is a cell loss of nearly 13% in the myopathic heart. A consideration of the significance of wider and longer myocytes with undiminished myofibrillar mass lead to the conclusion that the decreased contractility displayed by the cardiomyopathic hamster heart must be due, at least in part, to functional defects in the myofibrillar apparatus, in the system of activation, or in cellular integration.

Age Factors↗
PubMed1985

Therapy for late post infarction ventricular tachycardia.

Non-sustained ventricular tachycardia (VT) in the late post myocardial infarction (MI) period (7-21 days) has been reported to be a predictor of sudden death. We suspected that patients with 3 beat VT on Holter monitoring in the late infarction period would demonstrate electrical instability at electrophysiologic studies. Forty-seven patients were identified as having at least 3 beat VT on Holter monitoring. Eighteen patients refused electrophysiologic studies or were not referred by their attending physician. The mean ejection fraction of this group was 43 +/- 16%. Eight patients have died, 3 sudden deaths in 13 +/- 5 months, a 17% incidence of sudden death. Twenty-nine patients underwent invasive electrophysiologic studies. Their mean ejection fraction was 37 +/- 7%, and 28 had inducible, 18 sustained ventricular tachycardia and 10 non-sustained VT. No complications were noted with electrophysiological testing in the post infarction patients. Using programmed electrical stimulation studies an effective antiarrhythmic agent preventing VT induction (usually experimental) could be found for each patient. After a mean follow-up of 12.5 +/- 4 months, the patient without inducible VT is alive and 26 of the 28 "inducible" patients are alive and well. Two patients died, one of stroke and one due to pump failure following a second MI. No sudden deaths were observed in this group. Two patients had breakthrough arrhythmias and were treated by alternative antiarrhythmic therapy that was also effective at the initial electrophysiologic studies. Thus, PES studies post MI are safe and may be an effective way to assess therapy for patients in the early post MI period, identified at high risk for sudden death.

Aged↗
PubMed1985

Long term lorcainide therapy guided by electrophysiology studies.

One hundred patients inducible at electrophysiologic studies underwent serial drug testing with procainamide, lidocaine and lorcainide to determine comparative efficacy. Acute intravenous administration was followed by repeat programmed electrical stimulation (PES) studies on separate days for each antiarrhythmic drug. Lorcainide prevented VT induction in 69% of the 100 patients studied, procainamide was effective in 50% of the 75 patients studied, and lidocaine prevented VT induction in 30% of 53 patients. Following PES and serial drug testing, 46 patients were started on lorcainide, 9 patients on procainamide, and 45 patients were started on other antiarrhythmic drug regimens. Seventy percent of the patients have remained on lorcainide therapy, while 47% have continued on other drug therapies started over a 20.5 +/- 3.2 month mean follow-up period. Despite sleep-wake disturbances and a need for sedation at night, lorcainide therapy was tolerated well in this population and remained an effective antiarrhythmic with prolonged administration.

Administration, Oral↗
PubMedDate not supplied

Renal hypertensive hypertrophy in the rat: a substrate for arrhythmogenicity.

We investigated the ability of ouabain to produce lethal arrhythmias in rats with myocardial hypertrophy resulting from chronic renal hypertension. A gradual pressure overload was produced in female Wistar rats by left renal artery stenosis (two kidney, one clip, Goldblatt hypertension). Hypertension (systolic blood pressure greater than 150 mm Hg) developed within three weeks after clipping of the left renal artery and blood pressure continued to increase for the next five weeks. At ten weeks after the onset of hypertension animals were anesthetized with sodium pentobarbital (40 mg/kg) and artificially ventilated with room air while ECG was continually monitored and recorded. Continuous infusion of ouabain was maintained (0.7 mg/kg/min) through the inferior vena cava. Body weight and heart rate of control animals (C) was not significantly different from hypertensive (H) values, while systolic blood pressure in animals hypertensive for ten weeks was considerably greater (187 +/- 8.4 mm Hg) than their age-matched normotensive counterparts (123 +/- 6.0 mm Hg). Heart weight in hypertensive animals was elevated by 69% +/- 2.5 by time of study. Serological evaluation of both groups of animals revealed no significant differences in electrolytes and blood gases while significant differences were noted in glucose, BUN and creatinine. The average time to the first premature ventricular contraction was significantly shorter in H animals (3.5 +/- 0.2 min) when compared to C rats (6.0 +/- 0.2 min). The average time to ventricular tachycardia, ventricular fibrillation and death were also significantly shorter in H rats when compared to C animals (7.5 +/- 0.6 vs. 13.5 +/- 0.3; 13.5 +/- 0.5 vs. 21.0 +/- 0.5; 15.6 +/- 0.4 vs. 24.0 +/- 0.6 min). Thus, the hypertensive hypertrophied myocardium displays an increased propensity for lethal cardiac arrhythmias due to ouabain.

Animals↗
PubMedDate not supplied

Effect of otitis media on development: a community-based study.

Otitis media history until age 3 years were recorded for 233 children as part of the surveillance in a Community Program for Promotion of Growth and Development (PROD) conducted in a western neighborhood of Jerusalem. Recurrent otitis media (6 or more episodes) occurred more frequently among children who were of North African or Asian origin, of lower social class and maternal education, and whose duration of breast feeding was less than 26 weeks. Children with recurrent otitis media also failed the 7-month hearing test more frequently than other children. The mean Developmental Quotient score at 2 years and the mean Stanford Binet score at 3 years were statistically significantly lower among children with recurrent otitis media, even after controlling for maternal origin and length of breast feeding. These findings underscore the importance of early identification and early intervention for otitis media.

Child Development↗