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Biomedical subjects

R J Boucek

Publications and source records attributed to R J Boucek.

At least 91 records · Page 5Linked to original sources
PubMed1979

A possible role for dehydrodihydroxylysinonorleucine in collagen fibre and bundle formation.

The concentrations of NaB3H4-reducible collagen cross-links were determined at the time when collagen fibres and bundles are observed in electron micrographs of connective tissue developing around the implanted Ivalon sponge in adult male rats. The highest radioactivity occurs with hydroxylysinonoreleucine and histidinohydroxymerodesmosine, and the lowest with lysinonorleucine, the reducible amounts of these cross-links remaining relatively constant as fibres and bundles appear. On the other hand, dihydroxylysinonorleucine amounts are low during the initial stages of connective-tissue formation and rise sharply as collagen fibres and bundles develop and collagen matures, as shown by increased resistance of insoluble collagen to digestion with bacterial collagenase. The bulk of hydroxylysinonorleucine and dihydroxylysinonorleucine is glycosylated, the former with galactosyl or glucosylgalactosyl residues and the latter with glucosylgalactosyl residues. The changing relationships between the amounts of 3H-labelled hydroxylysinonorleucine, glucosylgalactosyldihydroxylysinonorleucine and non-glycosylated dihydroxylysinonorleucine as fibres and bundles appear suggest three post-translational steps involving lysyl-derived cross-links in the organization of collagen into fibres and bundles.

Animals↗
PubMed1978

Use of prostaglandin E1 for emergency palliation of symptomatic coarctation of the Aorta.

Prostaglandin E1 (PGE1) was infused into the pulmonary artery in a 1-day-old infant with symptomatic coarctation. Umbilical artery pressure rose from 50/40 mm Hg before infusion to 83/48 mm Hg after infusion, indicating significant improvement in lower-body perfusion. Successful coarctation repair was performed during continued PGE1 infusion. To our knowledge, this is the first reported patient in whom PGE1 has been used for successful emergency palliation of symptomatic coarctation.

Aortic Coarctation↗
PubMed1978

Restrictive cardiomyopathy in an infant with massive biatrial enlargement and normal ventricular size and pump function.

Restrictive cardiomyopathy in an infant with massive biatrial enlargement and normal ventricular size has been reported only once previously [3]. We now present a 13-month-old patient with severe and progressive congestive heart failure who demonstrated normal ventricular cavity size with biatrial enlargement. Ejection fraction and echocardiographic ventricular function studies were normal.

Adolescent↗
PubMed1978

An inexpensive computer-aided system for quantitative echocardiography.

A comprehensive system has been developed to quantitatively analyze standard M-mode pediatric echocardiograms. It utilizes relatively inexpensive hardware together with a telephone coupling to a time-sharing computer. A complete patient report on the study is printed out upon completion, and all the data are digitally stored for future research computations. Initial and operating costs for this system are significantly less than for any comparable one available.

Diagnosis, Computer-Assisted↗
PubMed1978

Anatomical arrangement of muscle tissue in the anterior mitral leaflet in man.

Muscle tissue in atrioventricular (A-V) cardiac valve leaflets was studied in 35 human hearts and was found to be more prominent in the anterior leaflet of the mitral (MAL) than in the other valve leaflets. From serial sectioning and wax model reconstruction, the anatomic arrangement of the muscle in the MAL indicates bundles passing from the two commissural regions towards the mid-zone of the valve. Age did not appear to reduce the mass of muscle tissue in the MAL. The possibility of muscle contraction in the MAL increasing leaflet tension and accelerating post-artial movements received support by comparisons of the anterior and posterior leaflets of the mitral valve in their movements towards closure.

Adolescent↗
PubMed1978

Pharmacologic dilatation of the ductus arteriosus with prostaglandin E1 in infants with congenital heart disease.

Prostaglandin E1 (PGE1) has been used for successful palliation in nine infants with congenital heart disease. Seven patients had pulmonary atresia with ductal-dependent pulmonary blood flow. In this group, systemic O2 saturation increased from a mean value of 45% to 79% after infusion of PGE1, and surgical palliation was successfully done with the infants in stable condition, without hypoxemia or acidemia. An additional patient with coarctation of the aorta had marked ductal dilatation after PGE1 infusion as indicated by umbilical artery pulse pressure. The coarctation was repaired, with the infant in stable condition. The final patient had neonatal tricuspid insufficiency with right to left atrial shunting. Systemic O2 saturation was improved after PGE1 infusion, though the ductus was closed. The improved oxygenation was believed to be due to a reduction in pulmonary vascular resistance by PGE1. Prostaglandin E1 provides a powerful new tool for palliation of critical congenital heart disease in infants whose ductal constriction can markedly influence their clinical status.

Ductus Arteriosus, Patent↗
PubMed1977

Assessment of ventricular elements of mitral valve by left ventriculography.

In the left ventriculogram in the right anterior oblique projection the plane of the mitral valve is seen in profile and the papillary muscle shadows are outlined. The distance from the middle of the papillary muscles to the plane of the mitral valve during systole was used to assess the average length of the chordae tendineae, and the area of the papillary muscle shadows was measured as an index of hypertrophy in a series of hearts with mitral valve disease. Valvar mitral stenosis is characterised by slight reduction in the length of chordae tendineae and more hypertrophy of the papillary muscles, while in subvalvar mitral stenosis there is more shortening of the chordae tendineae and less papillary muscle hypertrophy. Valvotomy may lengthen the chordae tendineae in subvalvar mitral stenosis. In rheumatic mitral regurgitation length of chordae tendineae and papillary muscle size were normal. The measurements were not useful in assessing non-rheumatic mitral regurgitation.

Anthropometry↗
PubMed1977

Right and left heart size and function in infants with symptomatic coarctation.

Right and left heart volumes, ejection fractions and ventricular outputs were determined from biplane cineangiocardiograms in infants with symptomatic coarctation of the aorta and correlated with clinical and hemodynamic alterations. Patients were divided into two age groups: group 1, aged 3.5 to 14 days and group 2, 5 weeks to 7 1/2 months. Infants in group 1 had severe depressions of left ventricular ejection fraction and output associated with normal left ventricular size. The massive cardiomegaly in these infants results from right heart enlargement secondary to left-to-right atrial shunting, and pulmonary hypertensive right heart failure, and possibly a more distensible right than left ventricle. Infants in group 2 also have right, and to a lesser degree, left heart enlargement. Group 2 patients differ from group 1 infants in having less impairment of left heart pump function and significant left ventricular myocardial hypertrophy. Echocardiographic measurements of left ventricular pump function are normal or increased in postoperative patients. Thus alterations of left ventricular function in infants with symptomatic coarctation appear to be largely afterload related and do not indicate permanent impairment of left ventricular contractile function.

Age Factors↗
PubMed1976

Left heart volume characteristics following ventricular septal defect closure in infancy.

Left ventricular and left atrial volume, left ventricular ejection fraction, and left ventricular muscle mass were determined preoperatively and postoperatively in 13 patients who underwent surgical closure of ventricular septal defects in the first two years of life. Left ventricular end-diastolic volume and systolic output averaged 255 +/- 19% (+/- SEM) and 240 +/- 19% of normal, respectively, before operation but fell to within normal limits postoperatively. Left ventricular ejection fraction was normal preoperatively (100 +/- 4% of normal) and remained so after correction (106 +/- 3%, NS). Left ventricular mass was mildly elevated at the preoperative catheterization (271 +/- 21%) and decreased significantly following repair (P less than 0.001). However, the postoperative left atrial volume (147 +/- 14%) remained abnormal (P greater than 0.05). These data suggest that when early surgical closure of a ventricular septal defect is necessary because of failure of medical management, good results with regard to postoperative left ventricular size and function can be expected.

Cardiac Catheterization↗
PubMed1976

Right ventricular volume characteristics before and after palliative and reparative operation in tetralogy of Fallot.

Right heart volume data were obtained in 63 patients with tetralogy of Fallot. The patients were divided into three groups: 1) preoperative tetralogy (N=34); 2) post shunt procedure (N=14); 3A) post repair without outflow patch (N=10); 3B) post repair with an outflow patch (N=8). In Group 1 right ventricular end-diastolic volume (RVEDV), RV ejection fraction (EF), and RV systolic output (SO) were all mildly depressed. In post shunt patients, RVEDV was normal but RVEF remained depressed. RVEDV and RVSO increased following a shunt procedure, and these variables were larger in patients with a large versus a small shunt. In Group 3A RVEDV, RVEF, and RVSO were normal. In contrast in patients in Group 3B, RVEDV was increased averaging 177 +/- 15% of normal RVEF was depressed averaging 0.45 +/- 0.04, and RVSO was normal. RV size and pump function are abnormal in patients whose operation requires an outflow tract patch and the factors which may contribute to these abnormalities include a higher RV peak pressure, pulmonary incompetence, and a larger noncontractile outflow tract. Longitudinal studies relating these variables to clinical performance and exercise testing will be important in assessment of the importance of these abnormalities.

Blood Pressure↗
PubMed1976

Spontaneous resolution of massive congenital tricuspid insufficiency.

Four cases of congenital tricuspid insufficiency (CTI) are presented in whom spontaneous improvement occured. There was no evidence of Ebstein's disease in three of the four. All presented with similar clinical and laboratory findings including massive cardiomegaly, mild to moderate congestive heart failure, and moderate to severe desaturation. Catheterization data demonstrated severe TI and right-to-left atrial shunting. During the period of follow-up, up to 3.5 years, all symptoms have spontaneously disappeared. Clinical and angiocardiographic evidence for minimal residual TI have remained. Right atrial and right ventricular volume measurements were markedly abnormal initially and returned to normal or near normal. These measurements may be a useful method for quantitating the severity of tricuspid insufficiency. The course of the three infants with massive CTI (without Ebstein's disease) differs from previous reports and may be important both in formulating future management plans and in defining the etiology of the disorder.

Angiocardiography↗
PubMed1976

Right ventricular volume characteristics in ventricular septal defect.

Right and left ventricular volume characteristics were determined from biplane cineangiocardiography in 37 patients with isolated ventricular septal defects. Patients were divided into three categories as determined by the degree of left-to-right shunt: small shunt-less than 35% of pulmonary blood flow (N=9); moderate shunt-35-49% (N=8), and large shunt-greater than 50% (N=20). Right ventricular (RV) end-diastolic volume was increased above normal in 15 of 20 studies performed in patients with large left-to-right shunts and averaged 159 +/- 10% of normal (P less than 0.001). In contrast, only one of the patients in the small shunt group and only half of the patients in the moderate shunt group showed increases in RV end-diastolic volume. The increase in RV volume was proportional to the corresponding increase in left ventricular end-diastolic volume, with the right ventricle ranging from 48 to 116% of LV end-diastolic volume (average 83%). Right ventricular ejection fraction was normal in all patient groups. Right ventricular outpur was increased commensurate with the increases in the RV end-diastolic volume. These data indicate that substantial augmentation in RV end-diastolic volume does occur in patients with isolated ventricular septal defects and large left-to-right shunts. These data can be explained by the significant diastolic and "isovolumic" shunting from left ventricle to right ventricle which occurs in these patients.

Cardiac Output↗
PubMed1976

Variations in 35SO4 incorporation into glycosaminoglycans along canine coronary arteries. A possible index of artery wall stress.

Focal areas of accentuated wall stress along the course of canine coronary arteries may be revealed by the level of 35SO4 incorporation into glycosaminoglycans (GAG). In the anterior descending artery, 35SO4 incorporation in higher in the proximal than in the distal region and may be extraordinarily high as the vessel enters a proximally located muscle bridge and at the takeoff region of multidirectional branches. In the circumflex artery, the incorporation also is higher in the proximal than in the distal region and is high at the genu where the posterior descending artery forms. There are differences in uptake of 35SO4 in vessels even when the arteries arise from the same vascular bed.this was shown by the higher incorporation in the left coronary artery than in the right coronary artery. A general anatomical agreement exists between these sites of high 35SO4 incorporation and previously described locations of interval elastic disruption ans proliferation of intimal connective tissue in the dog.

Animals↗
PubMed1975

Conal contribution to the electrocardiogram of chick embryo hearts.

Contraction of the conus arterisus (conus) is visibly delayed in the tubular heart of the chick embryo, and since the electromechanical coupling interval of isolated conal segment is similar to other areas of the embryonic heart, the delayed contraction of the conus indicated an impedance in the spread of the depolarization wave across the ventriculo-conal (VC) junction. A surface electrode placed on the conus of hearts obtained from the 72-hour chick embryo records a deflection, termed the C wave, appearing between the QRS complex and the T wave. To establish that the C wave arose from below the atrioventricular sulcus, atria were removed from a series of hearts from 96-hour embryos and the electrogram revealed a C wave without a P wave. The VC junction responds to digitoxin just as the atrioventricular tissue. Digitoxin prolongs the interval between the QRS and the C wave prior to a complete block in a manner analogous to the PR interval increase prior to the development of the Wenckeback phenomenon or complete atrioventricular block. As the embryonic heart developed after 96 hours, the C wave was no longer identifiable in the ECG.

Action Potentials↗