In vitro differentiation and antigenic changes in human melanoma cell lines.

Malignant transformation of melanocytes may be associated with changes in the expression of HLA antigens and melanoma-associated antigens (MAA). To determine whether these changes reflect the differential expression of HLA antigens and MAA by melanocytes at different stages of differentiation, we have studied the effect of the reversible induction of differentiation by fibroblast interferon (interferon beta) and/or 12-O-tetradecanoyl-phorbol 13-acetate (TPA) on the expression of HLA antigens and MAA by the melanoma cell lines DU-2, FO-1 and HO-1. The three melanoma cell lines differed in their sensitivity to the differentiating and antiproliferative activity of these two compounds and displayed an increased growth suppression and induction of differentiation, when incubated with the combination of TPA and interferon beta.

Enhanced in vitro growth suppression of human glioblastoma cultures treated with the combination of recombinant fibroblast and immune interferons.

In the present study we have evaluated the effect of recombinant human fibroblast, IFN-beta ser, and immune, IFN-gamma, interferon, alone and in combination, on the proliferation of fifteen early passage human glioblastoma cell cultures. Explant cultures were established from glioblastoma tumor tissue obtained at the time of surgery. After sufficient outgrowth, cultures were dispersed with trypsin/versene and maintained as independent cell lines.

Immunohistochemical localization of procainamide in normal, ischemic, and necrotic canine myocardium during acute experimental myocardial infarction.

This report represents the first application of immunohistochemical methods for localizing an exogenously administered drug. Intravenously administered procainamide was localized in normal, ischemic, and necrotic myocardium in 23 dogs. Rabbit antiprocainamide antibodies were used in an avidin-biotin-peroxidase complex staining method.

Effect of recombinant human fibroblast interferon and mezerein on growth, differentiation, immune interferon binding and tumor associated antigen expression in human melanoma cells.

The combination of recombinant human fibroblast interferon (INF-delta) and the antileukemic compound mezerein (MEZ) results in a synergistic suppression in the growth of human melanoma cells and a concomitant increase in melanin synthesis. In the present study we have further analyzed this synergistic interaction and have also evaluated the effect of IFN-delta and MEZ, alone and in combination, on recombinant human gamma interferon (IFN-gamma) binding and Class I HLA and melanoma associated antigen (MAA) expression in the HO-1 human melanoma cell line. Single cell clones isolated from the HO-1 cell line varied in their sensitivity to the antiproliferative effects of IFN-delta and MEZ.

Distribution of fibrinogen and albumin in normal, ischaemic, and necrotic myocardium during the evolution of myocardial infarction: an immunohistochemical study.

The role of mediators of inflammation in the pathogenesis and evolution of myocardial infarction has attracted increased interest as interventions which inhibit the inflammatory response after coronary artery occlusion have been shown to decrease infarct size. The distribution of fibrinogen and albumin in ischaemia myocardium after closed chest balloon occlusion of the left anterior descending coronary artery was studied by immunohistochemical techniques in 34 dogs, and compared to morphological evaluation of cellular injury. In myocardium which was ischaemic but not necrotic (that is, glycogen loss and the absence of light and electron microscopic and tetrazolium staining evidence of necrosis, n = 8 dogs) no accumulation of these proteins was detected within the ischaemic zone.

Limitations of postmortem assessment of human coronary artery size and luminal narrowing: differential effects of tissue fixation and processing on vessels with different degrees of atherosclerosis.

Numerous studies have utilized histologic sections of coronary arteries as the standard for testing the validity of the angiographic determination of coronary artery dimensions. However, little attention has been given to artifactual dimensional changes that occur during fixation and histologic processing of tissues (dehydration, clearing, embedding, sectioning and staining). Using planimetric techniques, the dimensional changes that occurred with fixation and processing were quantitated in 61 coronary artery segments with minimal or moderate to severe atherosclerosis obtained from 12 patients studied at autopsy.

Immunohistochemical localization of 6-keto-PGF1-alpha in canine coronary vasculature.

The localization of the prostacyclin metabolite, 6-keto-PGF1-alpha, in canine coronary vasculature was accomplished using immunohistochemical techniques (avidin-biotin method of immunoperoxidase staining). Six-keto-PGF1-alpha was localized to the intimal endothelial cell layer of epicardial and intramyocardial arteries and veins. No specific staining was seen in the the media or adventitia of canine coronary vasculature, or in capillaries, or myocardial fibers.

Distribution of cytosolic and mitochondrial aspartate aminotransferase in normal, ischemic, and necrotic myocardium. An immunohistochemical study.

We utilized immunoperoxidase methods to study the distribution of both cytosolic or soluble(s) and mitochondrial (m) aspartate aminotransferase (AspAT) in normal, ischemic, and necrotic myocardium. Human myocardium was obtained from autopsy (n = 9) and surgery (n = 6). Cardiac tissue from 26 dogs with experimental myocardial infarction induced by closed-chest balloon occlusion and four dogs with myocardial ischemia without necrosis induced by a 50% reduction in left main coronary artery flow for 3 hours were studied.

Myocytolysis (vacuolar degeneration) of myocardium: immunohistochemical evidence of viability.

Human myocardium with focal myocytolysis (vacuolar degeneration, colliquative myocytolysis) was examined by routine light microscopy and by immunoperoxidase staining techniques for creatine kinase (CK) M and B, myoglobin, lactate dehydrogenase (H4)(LDH-1), and aspartate aminotransferase (AST, GOT). Sections of myocardium were selected from autopsy and surgical specimens from patients with and without clinical morphologic evidence of ischemic heart disease. Areas of coagulation necrosis showed loss of enzyme staining, while both normal and myocytolytic cells stained darkly.

Distribution of LDH-1 in normal, ischemic, and necrotic myocardium. An immunoperoxidase study.

To study the distribution of lactate dehydrogenase (LDH-1) (H4) in normal, ischemic, and necrotic myocardium using the peroxidase-antiperoxidase technic, the authors studied formalin-fixed paraffin-embedded sections of human (n = 11) and canine (n = 28) myocardium. All normal control myocardium showed positive immunostaining for LDH-1 (H4). In infarcts 10 hours or more old, the histologically necrotic myocardium (by triphenyl tetrazolium chloride staining) (TTC) showed markedly diminished immunostaining.