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Biomedical subjects

W C Roberts

Publications and source records attributed to W C Roberts.

At least 667 records · Page 37Linked to original sources
PubMed1975

Pathologic anatomy of the cardiomyopathies. Idiopathic dilated and hypertrophic types, infiltrative types, and endomyocardial disease with and without eosinophilia.

This presentation summarizes necropsy observations in patients with three types of cardiomyopathy: idiopathic, infiltrative, and endomyocardial disease. The idiopathic variety is subdivided into two types depending on the size of the ventricular cavity. In the dilated ventricular type the left ventricular wall is frequently less than 1.5 cm. thick, intracardiac thrombi are common, the atrioventricular valve rings usually are mildly dilated, and focal myocardial and endocardial scars are common. In the nondilated type (hypertrophic cardiomyopathy), the ventricular septum is usually thicker than the left ventricular free wall, which also is thick (greater than 1.5 cm.). When the septum is similar in thickness to the left ventricular free wall (symmetric), left ventricular outflow obstruction does not occur. When the septum is thicker than the left ventricular free wall (asymmetric), left or right ventricular outflow obstruction may or may not be present. The orientation of myocardial fibers one to another in the ventricular septum in the nondilated (hypertrophic) type is abnormal, whereas it is normal in the dilated ventricular type. Intracardiac thrombi are rare and atrioventricular valve rings are never dilated in the nondilated type of idiopathic cardiomegaly. The infiltrative types of cardiomyopathies include iron, calcium, lipids, mucopolysaccharides, granulomas, amyloid, and neoplasms. The first four usually are located within myocardial cells and the latter three, between myocardial cells. It is probable that all these myocardial infiltrates are capable of producing cardiac dysfunction, primarily on a restrictive basis. Endomyocardial disease may or may not be associated with eosinophilia. When the latter occurs, the eosinophils are structurally normal. Death is related to congestive cardiac failure. This category is actuality also in idiopathic.

Adolescent↗
PubMed1975

Ultrastructural features of degenerated cardiac muscle cells in patients with cardiac hypertrophy.

Degenerated cardiac muscle cells were present in hypertrophied ventricular muscle obtained at operation from 12 (38%) of 32 patients with asymmetric septal hypertrophy (hypertrophic cardiomyopathy) or aortic valvular disease. Degenerated cells demonstrated a wide variety of ultrastructural alterations. Mildly altered cells were normal-sized or hypertrophied and showed focal changes, including preferential loss of thick (myosin) filaments, streaming and clumping of Z band material, and proliferation of the tubules of sarcoplasmic reticulum. Moderately and severely degenerated cells were normal-sized or atrophic and showed additional changes, including extensive myofibrillar lysis and loss of T tubules. The appearance of the most severely degenerated cells usually reflected the cytoplasmic organelle (sarcoplasmic reticulum, glycogen, or mitochondria) which underwent proliferation and filled the myofibril-free areas of these cells. Moderately and severely degenerated cells were present in areas of fibrosis, had thickened basement membranes, and had lost their intercellular connections. These observations suggest that degenerated cardiac muscle cells have poor contractile function and may be responsible for impaired cardiac performance in some patients with chronic ventricular hypertrophy.

Adolescent↗
PubMed1975

The nuclear membranes in hypertrophied human cardiac muscle cells.

Nuclear membranes of cardiac muscle cells were studied in 134 patients with cardiac hypertrophy of various causes. Abnormalities observed consisted of: a) increased foldings and convolutions; b) nuclear pseudoinclusions formed by cytoplasmic organelles protruding into saccular invaginations of the nuclear membranes, and c) intranuclear tubules. The increased foldings and convolutions of the nuclear membranes and the nuclear pseudoinclusions appear to result from synthesis of nuclear membranes in excess of that needed to accommodate the increase in nuclear volume which occurs in hypertrophy. Intranuclear tubules were found in 6 patients and consisted of tubular invaginations, 400 to 650 A in diameter, of the inner nuclear membranes into the nucleoplasm. Some of these tubules were straight and cylindrical, and were associated with a peripheral layer of marginated chromatin; others were not associated with chromatin, appeared coiled and followed irregular courses. Intranuclear tubules in cardiac muscle cells probably represent an extreme cellular response to the stimulus of hypertrophy.

Adult↗
PubMed1975

Tuberous xanthoma in homozygous type II hyperlipoproteinemia. A histologic, histochemical, and electron microscopical study.

Histologic, histochemical, and ultrastructural studies of a tuberous xanthoma from a patient with homozygous type II hyperlipoproteinemia showed that all of the lipid was within histiocytic foam cells; no lipid was identified in interstitial regions or in blood vessels. Primitive mesenchymal cells, elongated perivascular and fibroblast-like cells, and lysosome-filled macrophages also were present within the xanthoma, indicating possible stages in the evolution of dermal mesenchymal cells into mature, cholesterol-rich foam cells. Morphologically, the lipid was in four different forms: large droplets, which were the dominant form, and membrane-bound crystals, concentric lamellar bodies, and ceroid. The paucity of membrane-bound lipid forms, relative to the abundant free lipid droplets, indicated that lysosomal digestion was a minor metabolic pathway for the intracellular metabolism of lipid in the xanthoma. Thus, nonlysosomal lipid storage in foam cells is a characteristic tissue response to the underlying metabolic defect in type II hyperlipoproteinemia.

Adolescent↗