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Biomedical subjects

A B Lewis

Publications and source records attributed to A B Lewis.

At least 73 records · Page 4Linked to original sources
PubMed1978

Echocardiography and perfusion scintigraphy in the diagnosis of pulmonary arteriovenous fistula.

The echocardiographic and perfusion scintigraphic evaluation of an adolescent boy with a pulmonary arteriovenous fistula is reported. Contrast echocardiography following the rapid intravenous injection of indocyanine green dye was utilized to document extracardiac right-to-left shunting. Perfusion lung scintigraphy demonstrated the presence of a single large pulmonary arteriovenous fistula. Contrast echocardiography and perfusion scintigraphy are minimally invasive, safe and easily performed techniques for the rapid diagnosis of pulmonary arteriovenous fistula.

Adolescent↗
PubMed1977

A psychological theory of child abuse.

This paper presents a detailed study of two patients hospitalized in a closed psychiatric unit on which the treatment program emphasized dynamically oriented individual psychotherapy and family therapy. The first patient was hospitalized following physical abuse of her four-year-old daughter, while the second was hospitalized for a postpartum depression eight weeks following the birth of her first child, a girl. Although the presenting pictures in these two patients were markedly different, the psychodynamic patterns were so similar that a detailed comparison of the two cases seems to offer useful insight into some of the psychological causes of child abuse.

Adult↗
PubMed1977

The saddle angle: constancy or change?

Serial cephalometric radiographs of 165 children have been used to analyze age-associated changes in the saddle angle (Ba-S-N). There are mean decreases in this angle of about 5 degrees from birth to 2 years in those with either a Class I or a Class II occlusion; later changes are slight. The mean values tend to be slightly smaller in Class I boys than in those with Class II. Generally, the means are slightly larger in boys than girls but in adults this sex difference is in the reverse direction while remaining slight. It is reasonable to conclude that change is dominant in the first two years. Even after pubescence the angle is not constant but the changes are much smaller. The variability of the angle is greater for Class II than Class I individuals and its variability is greater in girls than boys after 12 years. Almost all the median increments are negative; that is, the flexure of the cranial base decreases with age particularly if the increments begin at the first available radigraph. This tendency is more marked in Class II then Class I occlusion. The increments are markedly variable in each occlusion group with large changes occurring in some individuals. Correlations between the saddle angles at different ages are high; this shows a marked constancy of the relative levels for individuals. The correlations between increments are small; presumably this reflects the small sizes of these increments relative to error terms. In the present group the saddle angle is positively correlated with Ba-N length, but the correlation between the saddle angle and either cranial vault length of stature are near zero. These findings show that there is marked constancy within individuals after the age of 2 years although, as noted earlier, there is marked variability in the size of the angle at particular ages and the serial data for some unusual individuals show large changes that are generally decreases.

Adolescent↗
PubMed1977

Late elongation of the cranial base.

A single logistic curve was fitted to serial data for three cranial base lengths (S-N, Ba-N, and Ba-S) in 33 boys and 26 girls. Elongation during pubescence plus adolescence is greater in boys than girls for each length. The maximum rate of pubescent elongation occurs earliest in Ba-N. There are no consistent sex differences in the maximum rates of elongation but they occur considerably earlier in girls. Similarly, girls reach 95% of their adult lengths at younger ages than boys.

Adolescent↗
PubMed1977

Long-term results of the Mustard procedure.

Over a 10-year period, 123 patients with transposition of the great vessels underwent the Mustard procedure. The hospital mortality for the series was 10.6%. There were seven late deaths, five of which were presumable due to arrhythmia. Sinus rhythm was noted postoperatively in 53% of the patients. Almost all the survivors had achieved catch-up growth when evaluated 6 months to 10 years later. A growth spurt was more consistently seen in the patients who were operated on under 2 years of age. Physical endurance and school performance were on a par with their normal peers or better in about half of the survivors. Severe neurologic problems were present in five patients. Postoperative catheterizations in 42 patients showed a rather high incidence of residual interatrial shunts, mild left ventricular outflow obstruction, and mild superior vena caval obstruction. Pulmonary venous obstruction and serious tricuspid regurgitation were not encountered.

Adolescent↗
PubMed1976

In memoriam.

Explore the source record for details and available documents.

History, 20th Century↗
PubMed1976

Echocardiographic assessment of left-to-right shunt volume in children with ventricular septal defect.

Echocardiograms were performed in 20 infants and children with isolated ventricular septal defects (VSD) undergoing cardiac catheterization. The magnitude of the left-to-right shunt was expressed as the pulmonary-to-systemic flow ratio (Qp/Os) and was compared to a ratio of the echographic left atrial (LA) diameter to the aortic root (Ao) diameter (LA/Ao). The Qp/Qs was also compared to LA/m2. Thirty-three normal children served as controls. The LA/m2 and Ao/m2 were significantly larger in normal infants under one year of age than in children above one year. The LA/Ao, however, was not influenced by age or size. A strong linear relationship was found between Qp/Qs and the LA/Ao (r = 0.96). The LA/Ao measurement appears to be helpful in the noninvasive assessment of the left-to-right shunt in patients with VSD.

Adolescent↗
PubMed1976

Gestational changes in pulmonary vascular responses in fetal lambs in utero.

Pulmonary arterial (PA) blood flow patterns, changes in pulmonary blood flow, and pulmonary vascular responses to graded hypoxemia and intravenous acetylcholine (ACh) were studied in 15 fetal lambs in utero 3-12 days after surgical implantation of an electromagnetic flow transducer and PA catheter. Phasic PA flow in the fetus was forward only during the first third of systole, almost zero during midsystole, and backward during late systole and early diastole. In contrast, neonatal lambs showed forward PA flow throughout systole. The constriction of the fetal pulmonary vasculature in response to progressive hypoxemia varied with gestational age. At 103 days there was no significant drop in PA flow and only a small increase in pulmonary vascular resistance (Rp) with hypoxemia. The greatest increase in Rp was seen in fetuses after 121 days of gestation. This response was unaffected by alpha- and beta-sympathetic and parasympathetic blockade. Similarly, the pulmonary vascular response to ACh injected into the fetal jugular vein depended on gestational age. Little or no increase in pulmonary flow was noted in the youngest fetus, whereas ACh produced a marked increase in pulmonary flow in festuses over 120 days of gestation. These data suggest that the mechanisms by which hypoxemia constricts and ACh relaxes the pulmonary vascular smooth muscle are not fully developed in fetal lambs at 100 days of gestation and furthermore, that these mechanisms progressively develop during the last third of gestation.

Acetylcholine↗