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Biomedical subjects

W C Roberts

Publications and source records attributed to W C Roberts.

At least 577 records · Page 32Linked to original sources
PubMed1978

"Mitral stenosis" secondary to combined "massive" mitral anular calcific deposits and small, hypertrophied left ventricles. Hemodynamic documentation in four patients.

Certain observations are described in four elderly women with massive mitral anular calcific deposits, small thick-walled left ventricles and diastolic gradients between pulmonary artery wedge position (or left atrium) and left ventricle. All four patients had some degree of obstruction to left ventricular outflow. Examination at necropsy (two patients) or at operation (one patient) disclosed only focal fibrous thickening of the mitral leaflets without commissural or chordal fusion. By auscultation, none had mitral opening snaps, only two had loud first heart sounds and only one had a mitral diastolic rumble. Hemodynamic documentation of a diastolic gradient between pulmonary artery wedge position (or left atrium) and left ventricle in the presence of massive mitral anular calcific deposits and in the absence of diffuse disease of the mitral leaflets has not been demonstrated previously. The diastolic gradients are considered to result from the combination of the large mitral anular calcific deposits and the small, thick-walled, noncompliant left ventricles.

Aged↗
PubMed1978

Vascular complications of thorium dioxide.

Vascular complications occurring late after exposure to thorium dioxide (thorotrast) are described in two patients. One patient had both cerebral andmyocardial infarcts and died at age 25 years. Necropsy disclosed both adventitial and intimal fibrosis of the left carotid artery and greater than 75 per cent cross-sectional area luminal narrowing of both the left main and left anterior descending coronary arteries. The other patient, a 33 year old man, had no cerebral symptoms in life but total obstruction of the right carotid artery secondary to a thorotrastoma was found at necropsy. Vascular complications due to thorotrast appear to represent consequences of chronic alpha irradiation.

Adult↗
PubMed1978

Ventricular pseudoaneurysm after transaortic septal myotomy for hypertrophic subaortic stenosis.

Clinical and morphological features are described in a man in whom a pseudoaneurysm arising from the ventricular septum developed after transaortic septotomy for hypertrophic subaortic stenosis. Pseudoaneurysm of the left ventricle or ventricular septum has not been described previously in a patient with hypertrophic cardiomyopathy in whom only the transaortic approach was utilized for septotomy or septectomy or both. In addition, no previous studies have reported pseudoaneurysm arising from the ventricular septum.

Aortic Valve↗
PubMed1978

Prosthetic heart valves: which ones and why.

The type and to some extent the size of prosthesis are by far the most important factors determining the patient's prognosis. Extensive necropsy experience shows that in terms of hemodynamics, thrombogenesis, and deterioration-the three major criteria-none of the four main types of prosthetic valves in use today is ideal. Emphasis placed on the role of the referring cardiologist in the choice of surgeon and prosthesis.

Animals↗
PubMed1978

Prosthetic-valve endocarditis due to Listeria monocytogenes.

Clinical and necropsy observations in the case of a patient with prosthetic-valve endocarditis due to Listeria monocytogenes are presented. Although rare cases of L. monocytogenes infection of natural cardiac valves have been reported, this represents the first known case of infection of a prosthetic cardiac valve by this organism.

Aortic Valve↗
PubMed1978

Structural changes in Hancock porcine xenograft cardiac valve bioprostheses.

Gross and histologic observations are described in 51 Hancock glutaraldehyde-preserved porcine heterograft bioprostheses from 41 patients: 33 valves from 25 patients had been in place for less than 2 months (early) and 18 valves from 17 patients were examined at later periods up to 75 months (late) after implantation. The major gross changes were cuspal thrombosis (5 bioprostheses) and cuspal degeneration (3 bioprostheses). Major histologic changes observed in 44 bioprostheses (26 early and 18 late) examined histologically were: (1) fibrin deposits on inflow and outflow surfaces of the cusps; (2) inflammatory cell infiltrates; (3) histiocyte deposition; (4) giant cell formation, and (5) focal disruption of the fibrocollagenous structure of the cusps. These observations indicate that porcine bioprostheses are not biologically inert in the human circulation. Valve failure, however, is rare at the implantation periods studied.

Animals↗
PubMed1978

Left ventricular outflow tract obstruction due to systolic anterior motion of the anterior mitral leaflet in patients with concentric left ventricular hypertrophy.

Patients with hypertrophic cardiomyopathy (i.e., asymmetric septal hypertrophy) may show obstruction to left ventricular outflow under basal conditions or with provocative maneuvers. The presence of dynamic left ventricular outflow tract obstruction in patients with concentric ventricular wall thickening (but without abnormalities of the aortic valve) has been less well appreciated. Clinical and morphologic features of five patients with nondilated left ventricles and with left ventricular outflow obstruction are presented. In each patient peak systolic pressure gradients between left ventricle and systematic artery were measured at cardiac catheterization and ranged from 60-140 mm Hg under basal conditions or with provocation. Each patient had echocardiographically documented systolic anterior motion of the anterior mitral leaflet, which was apparently responsible for the outflow obstruction, and concentric left ventricular wall thickening (septal-free wall thickness ratio of less than 1.3). Two of the five patients had evidence of genetically transmitted hypertrophic cardiomyopathy, as evidenced by disorganized muscle cells in the ventricular septum or asymmetric septal hypertrophy in first degree relatives. Hence, left ventricular outflow tract obstruction associated with systolic anterior motion of the anterior mitral leaflet may occur in some patients with concentric left ventricular hypertrophy who do not have typical hypertrophic cardiomyopathy.

Adult↗
PubMed1978

Aschoff bodies at necropsy in valvular heart disease. Evidence from an analysis of 543 patients over 14 years of age that rheumatic heart disease, at least anatomically, is a disease of the mitral valve.

Among 543 necropsy patients over age 14 years with severe chronic valvular heart disease, Aschoff bodies were found in 11 patients (2%). The ages of the 11 patients ranged from 18 to 68 years (avg. 38), and nine had had a history of acute rhematic fever earlier in life. Clinically, nine of the 11 patients had mitral stenosis with or without dysfunction of one or more other cardiac valves, one had isolated aortic regurgitation, and one had both mitral and aortic regurgitation. All 11 patients had diffuse fibrous thickening of the mitral valve leaflets, and all but one had diffuse anatomic lesions of at least one other cardiac valve. No patient with anatomic lesions limited to the aortic valve had Aschoff bodies. Thus, among patients with chronic valvular heart disease, Aschoff bodies, the only anatomic lesion pathognomonic of rheumatic heart disease, indicate diffuse anatomic lesions of the mitral leaflets and usually also anatomic lesions of one or more other cardiac valves. The functional mitral lesion is usually stenosis.

Adolescent↗
PubMed1978

Calcific deposits in stenotic mitral valves. Extent and relation to age, sex, degree of stenosis, cardiac rhythm, previous commissurotomy and left atrial body thrombus from study of 164 operatively-excised valves.

The presence or absence and the extent of calcific deposits in excised stenotic mitral valves was determined by radiographs of the excised valve in 164 patients aged 26 to 72 years. The extent of the mitral calcific deposits was determined by the percent of the valvular circumference containing the deposits = grade 0 (14 patients); grade I = less than 25% (43 patients); grade II = 25-50% (34 patients); grade III = 51-75% (39 patients); and grade IV = greater than 75% (34 patients). The amount of calcific deposits in the stenotic mitral valves correlated with sex and with the mean diastolic pressure gradient across the mitral valve (P less than 0.05), but it did not correlate with the patient's age, cardiac rhythm, pulmonary arterial or pulmonary arterial wedge pressure, previous mitral commissurotomy, presence of thrombus in the body of left atrium or the presence of disease of one or more other cardiac valves.

Adult↗
PubMed1978

Gallium-67 citrate scanning in the staging of idiopathic pulmonary fibrosis: Correlation and physiologic and morphologic features and bronchoalveolar lavage.

Idiopathic pulmonary fibrosis is a fatal disorder characterized by interstitial fibrosis and parenchymal inflammation. Current concepts of this disease suggest that the inflammation precedes and probably induces the fibrotic state. To evaluate the extent and relative activity of the inflammatory process, we scanned patients with idiopathic pulmonary fibrosis using gallium-67, a radionuclide known to concentrate in regions of inflammation. To quantify the amount of isotope in the lung parenchyma, the 67Ga-index was developed, a parameter derived from estimates of the size of regional pulmonary uptake, the uptake intensity, and its texture. Evaluation of 67Ga scans in 30 patients with idiopathic pulmonary fibrosis and 19 control subjects demonstrated that the 67Ga-index in the group with idiopathic pulmonary fibrosis was significantly higher (P less than 0.001) than that in the control group. When compared with lung biopsy morphologic studies in 22 patients with idiopathic pulmonary fibrosis, the 67Ga-index correlated with the degree of interstitial cellularity (P less than 0.05) and the degree of alveolar cellularity (P less than 0.005). When compared with cellular analysis of bronchoalveolar lavage fluid in 17 patients with idiopathic pulmonary fibrosis, the 67Ga-index correlated with the differential percentage of neutrophils (P less than 0.05), but not lymphocytes, eosinophils, or macrophages. These studies indicate that 67Ga accumulates in the lungs of patients with idiopathic pulmonary fibrosis and is probably associated with the active inflammatory state. The associations of the 67Ga-index with morphologic features and bronchoalveolar lavage analysis suggest that quantitative evaluation of these scans may be useful in staging the activity of idiopathic pulmonary fibrosis and following responses to therapy.

Adult↗
PubMed1978

Ultrastructure of Hancock porcine valvular heterografts. Pre- and post-implantation changes.

Scanning and transmission electron microscopic studies were made of: 1) 15 glutaraldehyde-treated porcine valvular heterografts that had been implanted in patients for periods of time ranging from 2 days to 76 months; 2) unimplanted, commercially processed porcine aortic valves; and 3) unprocessed porcine aortic valves. Unimplanted, commercially processed valves showed loss of endothelium and acid mucopolysaccharides. Short-term (< 2 months) post-implantation changes consisted of insudation of plasma proteins, penetration of erythrocytes into surface crevices, formation of a thin surface layer of fibrin, and deposition of macrophages, giant cells and a few platelets. Longer term (> 2 months) changes consisted of progressive disruption of collagen, erosion of valvular surfaces, formation of aggregates of platelets, and accumulation of lipid. The surfaces of the leaflets did not become covered with endothelium or with a fibrous sheath. It is concluded that progressive breakdown of collagen is a critical factor in determining the long-term durability of glutaraldehyde-treated porcine valvular heterografts.

Animals↗
PubMed1978

Ultrastructure of the fibrous subaortic "ring" in dogs with discrete subaortic stenosis.

The subaortic fibrous "ring" in Newfoundland dogs with discrete subaortic stenosis is characterized by the presence of large, uni- and multinucleated, rounded connective tissue cells that resemble chondrocytes in several respects. Connective tissue adjacent to these cells is rich in acid mucopolysaccharides, small but cross-banded collagen fibrils, and small, poorly developed elastic fibers. The chondrocyte-like cells contain numerous cisternae of rough surfaced endoplasmic reticulum and prominent Golgi complexes, and they are surrounded by thick, concentrically arranged layers of basement membrane-like material. The differentiation of cellular and extracellular components of connective tissue in subaortic fibrous rings clearly differs in humans and in dogs with discrete subaortic stenosis.

Animals↗
PubMed1978

Twisting of an aorta-coronary bypass conduit: a complication of coronary surgery.

Twisting of an aorta-coronary bypass conduit was observed at necropsy in each of three patients. Three twists (540 degrees) just distal to the aortic anastomosis caused total obstruction of the bypass conduit to the left anterior descending coronary artery in one patient. A single twist (180 degrees) occurred in a bypass conduit in each of the othe two patients. Obviously, prevention of graft twisting is essential for successful bypass grafting.

Aged↗
PubMed1978

Anchoring fibrils. A new connective tissue structure in fibrotic lung disease.

Electron microscopic studies of lung were made and compared in 17 patients with lung disease (10 with idiopathic pulmonary fibrosis, 3 with collagen--vascular diseases, 3 with sarcoidosis, and 1 with chronic eosinophilic pneumonia) and in 5 control patients. In control patients, the alveolar epithelial cells were normal, and no hemidesmosomes were present between the plasma membranes and the basal laminae. In comparison, cuboidal alveolar epithelial cells were present in 15 of the patients with fibrotic lung disease; in 9 of these the alveolar epithelial cells were multilayered. In 7 of the latter 9 patients (5 with idiopathic pulmonary fibrosis and 2 with collagen-vascular diseases), the basal laminae of the alveolar epithelial cells were attached to the plasma membranes by hemidesmosomes and to the underlying interstitial connective tissue by "anchoring fibrils." These fibrils measured from 4000 to 6000 A in length and from 200 to 600 A in width. One or both ends of the anchoring fibrils inserted into thebasal lamina, often forming arcs through which collagen fibrils and connective tissue microfibrils penetrated. Anchoring fibrils showed a complex pattern of transverse banding, which differed from that of collagen and appeared to be symmetric about the center of the fibril. These anchoring fibrils, which resemble those in normal skin and other tissues, were not found in lungs of control patients. In addition, there was a significant correlation between the severity of the pulmonary fibrosis and the presence of anchoring fibrils. These observations suggest that in severe fibrotic lung disease, anchoring fibrils reinforce the attachment of the basal lamina of multilayered alveolar epithelial cells to interstitial connective tissue.

Adult↗
PubMed1978

Ultrastructure of the fibrous ring in patient with discrete subaortic stenosis.

Histologic and ultrastructural studies disclosed the presence of five tissue layers in fibrous rings excised at operation from five patients with discrete subaortic stenosis. These layers were: (1) a surface monolayer of endothelial cells; (2) a subendothelial layer rich in acid mucopolysaccharides and basement membrane-like material; (3) a fibroelastic layer containing collagen and small (1 micrometer or less in diameter) elastic fibers; (4) a layer of smooth muscle cells with thickened basement membranes, and (5) a central fibrous layer with large amounts of collagen and small amounts of elastic fibers. The connective tissue layers in the rings frequently were discontinuous. The layered arrangement of these rings resembles that of normal endocardium in the left ventricular outflow tract.

Adolescent↗