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Biomedical subjects

I David

Publications and source records attributed to I David.

At least 37 records · Page 2Linked to original sources
PubMed1991

Oral clofilium produces sustained lowering of defibrillation energy requirements in a canine model.

The effect of long-term oral administration of antiarrhythmic drugs on defibrillation energy requirements is not well understood. We examined the effect of clofilium, a drug that prolongs cardiac action potential duration without slowing cardiac conduction, on defibrillation energy requirements and ventricular effective refractory periods in a canine model during a 3-week period. Epicardial patch electrodes were implanted in 12 dogs, and baseline testing was conducted under fentanyl anesthesia on day 7. An oral clofilium (100 mg/day) regimen was started on day 8. Six clofilium-treated and six control dogs underwent repeated testing on days 14, 21, and 28 after surgery. Truncated trapezoidal shocks were given repeatedly at various stored energies in random order; delivered current and impedance were measured; and delivered energy was calculated. The energy and current for 50% success in defibrillation (E50 and I50, respectively) were determined. For control animals, E50 increased by a mean 34 +/- 78%, 60 +/- 83%, and 69 +/- 122% compared with baseline (day 7) on days 14, 21, and 28, respectively. In contrast, E50 in clofilium-treated dogs decreased by 39 +/- 62%, 24 +/- 33%, and 32 +/- 15% on days 14, 21, and 28, respectively. Mean current requirements (I50) remained relatively stable compared with baseline in control animals (-7 +/- 39%, +25 +/- 36%, +40 +/- 75% on days 14, 21, and 28, respectively). After clofilium administration I50 decreased by 36 +/- 22%, 32 +/- 17%, and 33 +/- 17% on days 14, 21, and 28, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Neuroendocrine response to clomipramine and desipramine--the evidence of partial determination by heredity and sex.

A single dose of clomipramine, 10 mg i.v., or desipramine, 25 mg i.m., was administered to seven healthy young sibling pairs in a randomized cross-over experiment. The response of serum growth hormone, prolactin and cortisol was measured. The main findings were (1) sex differences in the growth hormone and cortisol response to desipramine and (2) a significant genetic component of the prolactin and cortisol response to desipramine as indicated by significantly (p less than 0.05) lower within-pair than between-pair variance in the sibling pairs but not random pairs of the experimental subjects.

Adult↗
PubMed1988

Inhibitory effects of pyridoxal phosphate, ascorbate and aminoguanidine on nonenzymatic glycosylation.

Nonenzymatic glycosylation of serum albumin was studied in the presence of naturally occurring metabolites, pyridoxal, pyridoxal phosphate and ascorbate/dehydroascorbate, and a hydrazine compound, aminoguanidine. Pyridoxal, pyridoxal phosphate, ascorbate and dehydroascorbate, at concentrations of 0.1 mM or greater, significantly inhibited the nonenzymatic glycosylation of albumin. Aminoguanidine was the most potent inhibitor of nonenzymatic glycosylation and 54% or 85% inhibition occurred when 5 or 50 mM aminoguanidine, respectively, was present in the incubation mixture containing 20 mM glucose. A major effect of aminoguanidine was to lower the free glucose concentration in the incubation mixture by a direct reaction with glucose as judged by thin layer chromatography. The present studies suggest that vital metabolites such as pyridoxal phosphate and ascorbate may be potentially important in controlling glucose-induced nonenzymatic glycosylation of proteins. Pyridoxal phosphate forms a Schiff base with proteins as does glucose and therefore may be a preferable drug, over aminoguanidine which is a hydrazine, for inhibiting the effects of glucose-induced nonenzymatic glycosylation.

Ascorbic Acid↗
PubMed1987

Mitral valvuloplasty and repair for infective endocarditis.

The traditional therapy for acute bacterial endocarditis of the mitral valve refractory to medical treatment is valve replacement. Successful valvuloplasty may be feasible in selected cases, in which the infection is limited to a small portion of the mitral valve anulus. The following report describes a case in which valvuloplasty with excision of the affected valve was performed successfully with no recurrence of infection over a 3-year follow-up period.

Adult↗
PubMed1986

Mediastinal hematoma mimicking aortic rupture.

The case of a child who fell a relatively short distance and had clinical and x-ray findings consistent with a ruptured aorta is presented. At surgery, a mediastinal hematoma was found. Diagnostic and therapeutic implications are discussed.

Aorta, Thoracic↗
PubMed1986

Thoracic surgical implications of the yellow nail syndrome.

Idiopathic lymphedema associated with yellow discoloration of the nail beds constitutes the yellow nail syndrome. Pleural effusions and chronic sinusitis are also frequently present. This report describes a case of yellow nail syndrome in a 65-year-old woman.

Aged↗
PubMed1983

The new nurses.

Explore the source record for details and available documents.

Connecticut↗
PubMed1982

What is a ventricle? The single-ventricle trap.

Whether a chamber is or is not a ventricle is determined by its myocardial morphological characteristics, not by the entering atrioventricular (AV) valves. The anatomic characteristics of the morphologically right ventricle and the morphologically left ventricle have been well described, are widely understood, and do not need to be changed. What a ventricle is should not be redefined in terms of the AV connections because such redefinition is based on the classic definition of single ventricle, which itself is not satisfactory. This old definition is wrong in principle, violates the morphological method of diagnosis and designation of the cardiac principle, violates the morphological method of diagnosis and designation of the cardiac chambers, and has two kinds of exceptions. Consequently the classic definition of single ventricle must not be used as a paradigm (model) for the redefinition of what a ventricle is or is not. The approach and terminology based on the use of the unsatisfactory single-ventricle is or is not. The approach and terminology based on the use of the unsatisfactory single-ventricle paradigm approach and terminology based on the use of the unsatisfactory single-ventricle paradigm should be discontinued, eg, "primitive ventricle," "main chamber," "accessory chamber," "trabecular pouch." Being unnecessary, these nonmorphological components of the terminology of congenital heart disease may be omitted. Morphological anatomy, unadorned, is the key to clarity, simplicity, and accuracy.

Heart↗
PubMed1982

Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valves.

In 3 patients with absent pulmonary valve syndrome and absent ductus arteriosus, the lungs were injected and analyzed postmortem using morphometric techniques. Two patients had tetralogy of Fallot and 1 had D-transposition of the great arteries, the latter being the first autopsy-proved case of absent pulmonary valve with transposition. In addition to the expected dilatation of the central pulmonary arteries and compression of the mainstem bronchi, postmortem pulmonary arteriography revealed a bizarre pattern of hilar branching. Instead of single segmental arteries, tufts of arteries arose which entwined and compressed the intrapulmonary bronchi. In all 3 patients the histologic structure of the pulmonary arteries was abnormal. The elastic lamina of the media of the right and left pulmonary arteries were increased in number outside the lung, but were decreased within the lung. At both sites, the elastic laminae were thickened and fragmented. In the 2 ventilator-dependent patients, there was slight medial hypertrophy and extension of muscle into normally nonmuscular arteries. In 1 of the 2 cases in which the number of bronchial generations was counted, they were decreased, and in the 1 case in which bronchial count was unknown, alveolar multiplication was severely impaired. Therefore, our data may explain why, in some patients with absent pulmonary valve syndrome, relief of compression of the mainstem bronchi alone does not appreciably alleviate or reverse severe respiratory disease.

Bronchi↗
PubMed1982

Potentially parachute mitral valve in common atrioventricular canal: pathological anatomy and surgical importance.

An essentially single focus of left ventricular chordal insertion was found in 23 of 164 autopsied cases of common atrioventricular canal (CAVC) with a normally formed spleen (14%). Suture closure of the cleft of the mitral valve in such cases results in the surgical creation of parachute mitral valve, often with fatal iatrogenic mitral stenosis. In such patients, the cleft of the mitral valve is its main orifice and must not be sutured closed. There are four anatomic types of potentially parachute mitral valve in CAVC: (1) with one papillary muscle group and one mitral orifice (type 1A), in 10 cases (43%); (2) with one papillary muscle group and two mitral orifices (type 1B), in one case (4%); (3) with two papillary muscle groups and one mitral orifice (type 2A), in five cases (22%); and (4) with two papillary muscle groups and two mitral orifices (type 2B), in seven cases (30%). Parachute mitral valve exists only when the AVC is divided, either naturally or surgically. The essence of parachute mitral valve is an essentially single focus of chordal insertion. One or both left ventricular papillary muscle groups may be present. The presence of only one focus of left ventricular chordal insertion contraindicates cleft closure.

Adolescent↗