Richard G. Hibbs

Alcoholic cardiomyopathy. An electron microscopic study

Abstract Electron microscopic observations were made on specimens of myocardium obtained at autopsy from 6 patients who had died of heart disease diagnosed clinically as alcoholic cardiomyopathy. The abnormalities observed consisted of swelling of the endoplasmic reticulum, degenerative changes in the myofibrils, increased numbers of lipofuscin granules and lysosomelike bodies, large numbers of lipid droplets, mitochondrial swelling, alterations of the mitochondrial cristae, and the formation of dense intramitochondrial inclusions. The significance of these changes was discussed.

Isoproterenol-induced myocardial necrosis. A histochemical and electron microscopic study

Abstract Electron microscopic and histochemical alterations in heart muscle after the administration of isoproterenol are described in detail. Isoproterenol-induced myocardial necrosis develops more slowly than that resulting from coronary artery occlusion. The first prominent electron microscopic changes are: thickening of the Z lines, swelling of mitochondria, and enlargement of the vesicles of the endoplasmic reticulum. Little depletion of glycogen was observed in the early stages. Fat droplets in various stages of formation were observed within the vesicles of the endoplasmic reticulum. No fatty degeneration of the mitochondria was seen. Histochemical studies demonstrated an early rise in the succinic dehydrogenase activity, followed by a fall. No early rise was seen with the cytochrome oxidase reaction. The accumulation of fat droplets in myocardium was studied by a sensitive fluorescence microscopy technique. The significance of these observations and the relationship of fatty change in the myocardium to cellular injury are discussed.

The heart in Fabry's disease: A histochemical and electron microscopic study☆

Abstract Histochemical and electron microscopic studies of the heart of a patient with Fabrys disease (angiokeratoma corporis diffusum universale) revealed the presence of extensive glycolipid deposits in the cardiac muscle fibers, vascular smooth muscle, endothelium and connective tissue cells of the mitral valve. These deposits formed lamellae arranged either concentrically or in parallel stacks; the lamellae were often enclosed by limiting membranes and showed a periodic spacing of 40 to 45 A. The cardiovascular manifestations of Fabrys disease, which consist of cardiac hypertrophy and dilatation, congestive heart failure, anginal chest pain, myocardial infarction and hypertensive heart disease, are reviewed in detail. The association of this disorder with valvular heart disease is discussed.

Alcoholic cardiomyopathy a histochemical study

Abstract Histochemical observations were made on samples of myocardium obtained at autopsy in a series of 8 patients with alcoholic cardiomyopathy. The changes found consisted of an accumulation of neutral lipid in the myocardial fibers and varying degrees of mitochondrial damage, manifested by a pronounced decrease in the histochemical staining reaction for several mitochondrial oxidative enzymes. These observations were correlated with electron microscopic data obtained on the same patients and interpreted as being indicative of a process of myocardial degeneration, the end result of which is cell death and healing by fibrosis.

Idiopathic Myocardiopathy of the Puerperium (Postpartal Heart Disease)

It should be clearly understood that no evidence was uncovered to indicate an unequivocal etiology for this uncommon disease. One is tempted to qualify “uncommon” in that it no longer connotes the same extreme degree of rarity that would appear from medical literature. Over the same period that these cases were collected an equal number were recognized but unavailable for study for various reasons.Unfortunately, the size of our series precludes statistical analysis. The apparent tendencies to hypercholesteremia, blood-group predilection, and increased incidence of abnormal hemoglobin types are in need of further exploration. One would be remiss not to note at this point that at least one report20 related several instances of familial incidence of postpartal heart disease.We are more certain of the significance of malnutrition as a factor in the genesis of this syndrome, although we are unable to assign a precise role. Similarly, the deleterious effects on such patients of hypertension, pyelonephritis, and full-term pregnancy have impressed us, although we can make no judgment as to their frequency of occurrence. Probably, as so often happens, we are most certain of our single pre-investigatory premise that postpartal heart disease is a serious and pernicious syndrome, quite different from that described in most of the literature. That prolonged bed rest is not a panacea is obvious. It is of sufficient merit, however, to warrant use in all such patients, for periods up to 1 year at least.

Electron-microscopic observations on the human mast cell

Abstract Biopsy specimens of human skin and stomach were prepared for light and electron microscopy. Two cell types, both identifiable in stained preparations as tissue mast cells, are described. One cell type consisting of spindle-shaped cells is found in large numbers in the dermis and subcutis, and less frequently in the tunica propria and submucosa of the stomach. These cells are often found in association with small blood vessels. The granules of such cells are nearly homogeneous, but some of them contain one or more centrally located dense bodies. The second cell type consists of ovoid or spherical cells. These cells are found in only small numbers in the skin but are more numerous in the stomach wall. The granules of these cells are made up of two components: (1) a finely granular substance and (2) groups of lamellae. The lamellae are sometimes in the form of scrolls. A possible relationship of the two components of the granules to secretion is discussed.

The fine structure of the small blood vessels of normal human dermis and subcutis

Abstract Observations have been made on the small blood vessels of the dermis and subcutis of the human finger tip and abdomen. Two types of vessels have been described—vessels which closely resemble those of most other organs, and a second type of vessel never before reported. Vessels of the second type are found predominantly in the vicinity of sweat glands, and are lined by endothelial cells with the following characteristics: (1) small, dense, rod-shaped granules in the cytoplasm; (2) large bundles of very fine filaments in the cytoplasm; (3) groups of small vesicles in the cytoplasm, each group enclosed by a membrane; (4) thicker than typical endothelium, the cells in contracted vessels being pyramidal or columnar in shape. A possible functional signficance of this specialized endothelium has been suggested.

A histochemical and electron microscopic study of of epinephrine-induced myocardial necrosis

Abstract A histochemical and electron microscopic study was made of the effects of large doses of epinephrine on the rat heart. Diffuse changes observed in the initial phases of epinephrine toxicity consisted of the deposition of lipid droplets in the myocardial fibres, an increase in the activity of oxidative enzymes, and a rapid fall in myocardial glycogen. These alterations gradually subsided except in certain areas, mostly in the subendocardium, in which foci of myocardial necrosis developed with marked fatty degeneration and total loss of oxidative enzyme activity. Electron microscopy revealed swelling of the sarcoplasmic reticulum, the T-system, and the mitochondria. The mitochondrial cristae often developed angulations in their ordinarily straight, parallel surfaces. These changes appeared to be largely reversible. Alterations of the contractile elements were found only in association with myocardial necrosis and were characterized by hyalinization and loss of the striations.

A comparative histochemical and electron microscopic study of the surface coatings of cardiac muscle cells

Abstract An external lamina was present on the plasma membrane of the myocardial cells of all species studied. The thickness of this lamina measured about 1000 A in crustaceans, 300 to 400 A in fishes, 400 to 650 A in amphibians, 400 to 500 A in reptiles, and 200 to 400 A in mammals. Histochemical studies at the light and electron microscopic level showed that the external lamina is rich in carbohydrates with acidic residues. It is proposed that the external lamina acts as a selective barrier between the intra- and extracellular environment. As a circulatory system develops in the myocardium, this function is shared by the basal lamina of endocardial and capillary endothelial cells. A lamina similar to that of the plasma membrane was observed on the luminal surface of the transverse tubular system (T-system). However, a T-system was not found in cells in which the myofibrils are located primarily in the periphery of the cell, but only in cells in which the myofibrils are either centrally located or evenly distributed within the cell.

VIRUS-LIKE PARTICLES IN THE HEART OF A PATIENT WITH CARDIOMYOPATHY; AN ELECTRON MICROSCOPIC AND HISTOCHEMICAL STUDY.

Abstract Virus-like particles measuring 30 mμ in diameter were observed by electron microscopy in the heart muscle cells of a patient who probably had alcoholic cardiomyopathy, and who died shortly after developing an infection of the respiratory tract. Additional histochemical and electron microscopic studies of the myocardium revealed marked cellular damage manifested as varying degrees of lipid deposition, mitochondrial swelling and fragmentation, loss of intramitochondrial enzymes, and disruption of the contractile elements. The significance of these observations was discussed.