Search PubMed⌕ Search

Biomedical subjects

V J Ferrans

Publications and source records attributed to V J Ferrans.

At least 109 records · Page 6Linked to original sources
PubMed1996

Activated neutrophils secrete stored alpha 1-antitrypsin.

Neutrophil elastase (NE), a potent serine protease, is stored in primary granules of neutrophils and released following neutrophil activation. Alpha-1-antitrypsin (alpha 1-AT), the major inhibitor of NE, is synthesized by mature neutrophils. In the context of the maintenance of tissue homeostasis, we hypothesized that neutrophils may be able to store alpha 1-AT, thus having it available for release concordantly with NE. Immunofluorescence and quantitative flow-cytometric studies of neutrophils and monocytes labeled with fluorescein-conjugated alpha 1-AT-antibody demonstrated larger amounts of cytoplasmic alpha 1-AT in neutrophils than in monocytes. [35S]methionine-labeling and anti-alpha 1-AT immunoprecipitation analysis showed that although both neutrophils and monocytes synthesize alpha 1-AT, the proportion of newly synthesized intracellular alpha 1-AT was much higher in neutrophils than in monocytes. Flow-cytometric analysis showed that in the presence of surface stimulation with cytochalasin B followed by formyl-methionyleucylphenylalanine (fMLP), mean intracellular alpha 1-AT was decreased in stimulated neutrophils compared with that in resting cells, suggesting that the stored alpha 1-AT was rapidly released following surface triggering. Evaluation of surface-stimulated neutrophils by [35S]methionine labeling and anti-alpha 1-AT immunoprecipitation demonstrated increased secretion of alpha 1-AT compared with that of resting neutrophils, with some of the secreted alpha 1-AT capable of forming complexes with NE. Thus, neutrophils respond to surface stimulation not only by secreting NE but also by secreting its inhibitor, alpha 1-AT, suggesting that these cells have an inherent mechanism for damping the local effects of NE, their most powerful proteolytic enzyme.

Cytochalasin B↗
PubMed1996

Immunohistochemical study of metalloproteinases and their tissue inhibitors in the lungs of patients with diffuse alveolar damage and idiopathic pulmonary fibrosis.

Immunohistochemical and confocal microscopic studies of the localization of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and type IV collagen were made in lung tissues from patients with normal pulmonary histology (n = 3), diffuse alveolar damage (n = 14), and idiopathic pulmonary fibrosis (n = 12). Pretreatment with pepsin revealed otherwise undetectable MMP- and TIMP-immunoreactive sites. In normal lung, MMP-2, MMP-9, TIMP-1, and TIMP-2 were localized in ciliated cells, endothelial cells, pneumocytes, macrophages, and smooth muscle cells; fibroblasts showed a strong reaction only for MMP-2. Only TIMP-2 showed co-localization with type IV collagen. Myofibroblasts and epithelial cells expressed increased reactivity for MMPs and TIMPs in both disorders. The reactivities for MMPs and TIMPs were stronger in diffuse alveolar damage. MMP-2 showed focal co-localization in capillary endothelial and disrupted epithelial basement membranes, suggesting activation of collagenolysis. A protective effect against this lysis was suggested by the extensive co-localization of TIMP-2 with type IV collagen and fibrillar collagens. Alveolar buds showed increased reactivity for MMPs and TIMPs in their lining epithelial cells, myofibroblasts, and their basement membranes; however, their matrices were mostly unreactive. These findings emphasize the complexity of the roles of MMPs and TIMPs in collagen turnover in diffuse alvcolar damage and idiopathic pulmonary fibrosis.

Adolescent↗
PubMed1995

Requirement for generation of H2O2 for platelet-derived growth factor signal transduction.

Stimulation of rat vascular smooth muscle cells (VSMCs) by platelet-derived growth factor (PDGF) transiently increased the intracellular concentration of hydrogen peroxide (H2O2). This increase could be blunted by increasing the intracellular concentration of the scavenging enzyme catalase or by the chemical antioxidant N-acetylcysteine. The response of VSMCs to PDGF, which includes tyrosine phosphorylation, mitogen-activated protein kinase stimulation, DNA synthesis, and chemotaxis, was inhibited when the growth factor-stimulated rise in H2O2 concentration was blocked. These results suggest that H2O2 may act as a signal-transducing molecule, and they suggest a potential mechanism for the cardioprotective effects of antioxidants.

Acetylcysteine↗
PubMed1995

Morphologic and morphometric evaluation of the effect of ICRF-187 on bleomycin-induced pulmonary toxicity.

Morphologic and morphometric studies were made of the protective effects of ICRF-187 against the pulmonary damage induced by bleomycin in male and female C57/BL6 mice. Sixty minutes prior to the subcutaneous administration of 15 mg/kg of bleomycin, animals received either saline or ICRF-187 (300 or 150 mg/kg) intraperitoneally, twice a week for 4 weeks. The lungs of animals treated with bleomycin alone showed inflammation, hyperplasia of type II epithelial cells, squamous cell metaplasia and fibrosis. The extent of fibrosis was quantified by means of a color videometric system and histologic sections of lung stained according to a modified Masson trichrome method. The severity of these alterations, particularly of fibrosis, was reduced in all groups of animals pretreated with ICRF-187. The fibrosis was reduced to a similar extent in female mice treated with the 300 mg/kg and the 150 mg/kg doses of ICRF-187, from 39.3% to 17.6% and 13.3%, respectively. ICRF-187 induced significantly different degrees of reduction in fibrosis in the 2 groups of male mice treated with the 150 mg/kg and the 300 mg/kg doses, from 30% to 19.7% and 12.2%, respectively. In vitro studies indicated that both ICRF-187 and its open-ring hydrolysis product (ADR-925) remove iron slowly from the bleomycin-iron complex. This observation provides a basis for the concept that ICRF-187 protects by chelating iron involved in the formation of the bleomycin-Fe3+ complex that generates reactive oxygen radicals capable of causing pulmonary damage.

Animals↗
PubMed1995

Abnormalities in elastic fibers and other connective-tissue components of floppy mitral valve.

Histologic, immunohistochemical, and ultrastructural studies were performed on 12 floppy mitral valves, 4 mitral valves showing focal myxomatous changes without prolapse, and 3 normal mitral valves. All floppy mitral valves were thickened by deposits of proteoglycans and also showed diverse structural abnormalities in collagen and elastic fibers. From these observations we conclude that (1) the structure of all major components of connective tissue in floppy mitral valves is abnormal; (2) alterations in collagen and accumulations of proteoglycans are nonspecific changes that may be caused by the abnormal mechanical forces to which floppy mitral valves are subjected because of their excessively large surface area; (3) the presence of excessive amounts of proteoglycans may interfere with the normal assembly of collagen and elastic fibers; (4) abnormalities of elastic fibers resemble those in other conditions characterized by structural dilatation or tissue expansion; and (5) alterations in elastin could result from defective formation, increased degradation, or both.

Actin Cytoskeleton↗
PubMed1995

Significance of early intra-alveolar fibrotic lesions and integrin expression in lung biopsy specimens from patients with idiopathic pulmonary fibrosis.

To study the pulmonary structural remodeling in idiopathic pulmonary fibrosis (IPF), ultrastructural, immunohistochemical, and light microscopic morphometric observations were made on 11 pulmonary biopsy specimens from patients with IPF. The morphometric study was done using sequentially cut tissue sections stained for keratin-alcian blue periodic acid-Schiff (PAS), fibronectin, and type IV collagen-alcian blue PAS. Most of the early fibrotic lesions, which were alcian blue- and fibronectin-positive, were intra-alveolar in location. Intra-alveolar fibrosis is considered to be essential for the fusion of alveolar walls in IPF. A strong reaction for integrin alpha 5 beta 1 and vinculin was found in epithelial cells and mesenchymal cells in areas of intra-alveolar fibrosis. These findings show that these cells are active in adhesion to fibronectin in areas of early intra-alveolar fibrosis. Some of the epithelial cells, including cytoplasmic hyaline-laden cells, showed evidence of inadequate adhesion to the extracellular matrix, and this may constitute one of the mechanisms of progression of fibrosis in IPF.

Adult↗
PubMed1995

Immunofluorescence techniques for the identification of immune effector cells in rat heart: applications to the study of the myocarditis induced by interleukin-2.

A detailed description is presented of immunohistochemical methods for identification of various types of immune effector cells in rat heart, involving the use of antibodies conjugated with different fluorochromes for the simultaneous demonstration of 2 or 3 different antigens by means of fluorescence microscopy. The initial results of the application of these techniques to the study of the myocarditis induced by interleukin-2 (IL-2) are also presented. Antibodies used included: OX6 antibody (for MHC class II molecules, mainly expressed by dendritic cells): W3/25 and OX8 antibody, for the demonstration of the rat equivalents of CD5 and CD8, respectively: asialo-GM1 ganglioside antibody for the identification of natural killer (NK) cells and lymphokine activated killer (LAK) cells, and ED2 antibody for labeling of macrophages. Fluorochromes used were: fluorescein isothiocyanate (green), tetramethylrhodamine isothiocyanate (red), Texas red sulfonyl chloride (red), and 7-amino-4-methylcoumarin-3-acetic acid (blue). IL-2-induced myocarditis was characterized histologically by infiltration of the myocardium by mononuclear inflammatory cells, microvascular alteration, interstitial edema, and myocyte damage and necrosis. In the initial stages, NK/LAK cells were the predominant type of infiltrating lymphocytes; however, the numbers of these cells decreased sharply in subsequent stages. Macrophages also were initially abundant, and continued to be prevalent throughout the late stages. CD8+ lymphocytes were more numerous than CD4+ lymphocytes. Dendritic-cells showed a diffuse increase in number and also accumulated around foci of myocyte necrosis. Three phenotypes of dendritic cells were recognized, and the possible implications of these findings are discussed. It is hoped that these techniques will prove useful for the immunohistochemical evaluation of various inflammatory diseases of the heart.

Animals↗
PubMed1995

A comparison of failure modes of glutaraldehyde-treated versus antibiotic-preserved mitral valve allografts implanted in sheep.

Morphologic studies and calcium analyses were made on mitral valve allografts from 12 juvenile sheep surviving 12 to 24 weeks after mitral valve replacement. Before implantation, the allografts were treated with 0.625% glutaraldehyde (group I, n = 4) or with cold antibiotic solution (group II, n = 8). Three group I animals died 12 to 19 weeks after implantation because of dysfunction of calcified valves; the surviving animal also had extensive allograft calcification. One group II animal died of mitral regurgitation; the valves of the other seven (including five with regurgitation shown by Doppler and ventriculographic studies) were explanted at 19 to 24 weeks. Chordal rupture related to calcific deposits was found in all group I valves. Leaflet perforations (n = 4) and ruptured chordae (n = 4), each caused by connective tissue deterioration, were found in group II valves. Inflammatory reaction was absent or minimal in group I valves but moderate or severe in group II valves. Fibrous sheaths were thicker in group II than in group I valves. Calcium levels were much higher in group I than in group II valves. Calcification in group I valves was diffuse and involved collagen, elastic fibers, and connective tissue cells and matrix; in group II valves, it was localized in connective tissue cells. Thus glutaraldehyde-treated allografts failed because of extensive calcification, whereas antibiotic-preserved allografts underwent deterioration of connective tissue and infiltration by inflammatory cells.

Animals↗
PubMed1995

Alveolar fibrosis and capillary alteration in experimental pulmonary silicosis in rats.

To analyze the evolution of fibrotic and vascular changes in pulmonary silicosis, ultrastructural and immunohistochemical studies were made of the lungs of rats given a single intratracheal injection of silica particles. Early lesions were characterized by accumulations of macrophages and neutrophils in alveolar lumina and interstitium and by damage to alveolar capillaries and epithelial cells. The intraluminal masses of inflammatory cells developed into granulomas and became associated with myofibroblasts that migrated from the interstitium through the damaged epithelial lining. Type II epithelial cells and bronchiolar cuboidal cells proliferated rapidly to line the intraluminal granulomas, incorporating them into the interstitium. This process mediated the transition from intraalveolar fibrosis to interstitial fibrosis. Vascular damage was repaired by proliferation and migration of endothelial cells. Some endothelial cells in alveolar capillaries expressed Factor VIII-related antigen at 2 wk after silica infusion. In normal animals, this feature was present in peribronchiolar but not in alveolar capillaries. Two patterns of endothelial cell migration were shown by staining for proliferating-cell nuclear antigen. The first pattern was characterized by endothelial cells that extended their cytoplasm over preexisting, denuded basement membranes and replaced necrotic cells in alveolar capillaries. At 4 mo after injury, some of these cells had developed fenestrations. The second pattern consisted of budlike sproutings that developed only in peribronchiolar connective tissue. These observations indicate that peribronchiolar vessels are sources for renewal of alveolar capillary endothelium as well as for neovascularization.

Animals↗
PubMed1995

[Possibility for clinical use of mitral valve allograft: an experimental histopathological study in consideration with aortic valve allograft].

Morphologic studies were made on antibiotic preserved mitral valve allograft implanted in 8 sheep for 12 to 24 weeks. All allograft showed severe deterioration of connective tissue due to autolysis and immunological/inflammatory reactions. Compared with aortic valve allograft, mitral valve allograft failed more quickly and more severely, presumably because of differences in structure (presence of chordae tendineae and increased surface area of leaflets) and in closing pressure. The durability of cardiac valve allograft is influenced by the degree of preservation of collagen and elastic fibers in the graft. attenuation of immunologic reactions and control of fibrous sheathing.

Animals↗
PubMed1994

3,5,3'-Triiodo-L-thyronine induces cardiac myocyte differentiation but not neuronal differentiation in P19 teratocarcinoma cells in a dose dependent manner.

P19 teratocarcinoma cells differentiate into neurons or muscle when treated with varying doses of retinoic acid, dimethylsulfoxide, thioguanine or butyrate. We induced cardiac differentiation in P19 cells by treating them with 3,5,3'-Triiodo-L-Thyronine (T3). P19 cells received doses of T3 ranging from 30 pM to 300 nM. The beating colonies were counted, and a dose response curve showed that the optimal concentration of T3 was 30 nM. The colonies beat rhythmically for 4-6 weeks, and the cardiac myocytes showed clearly evident cardiac-specific organelles such as nexuses and atrial granules. No evidence of neuronal or skeletal muscle differentiation was seen with any of the concentrations of T3 used. Reverse transcription-polymerase chain reaction showed these cells to express the cardiac ventricular specific marker myosin light chain 2V. T3 is capable of inducing P19 cells to differentiate, in a dose related manner, into spontaneously beating cardiac myocytes identified as such on the basis of ultrastructural criteria. The induction of differentiation is accompanied by expression of cardiac-specific genes. These findings suggest that perhaps genes bearing thyroid response elements in their promoter regions play an important role in the cardiac differentiation induced by T3 in P19 teratocarcinoma cells.

Animals↗
PubMed1994

Effects of ICRF-186 [(L)1,2-bis(3,5-dioxopiperazinyl-1-yl)propane] on the toxicity of doxorubicin in spontaneously hypertensive rats.

An evaluation was made of the protective effects of ICRF-186 [(L)1,2-bis(3,5-dioxopiperazinyl-l-yl)propane], the L-enantiomer of ICRF-187 [(D)1,2-bis(3,5-dioxopiperazinyl-l-yl)propane], against the cardiotoxicity and nephrotoxicity induced in spontaneously hypertensive rats (SHR) by doxorubicin. SHR were given doxorubicin (1 mg/kg, i.v.), once a week for 12 weeks. Group 1 (n = 10) received doxorubicin alone; Groups 2, 3 and 4 (each, n = 5) received ICRF-186, 25 mg/kg (group 2), 12.5 mg/kg (group 3) or 6.25 mg/kg (group 4), i.p., 30 min before each dose of doxorubicin. Two groups of control animals (each, n = 5) received 12 weekly i.p. injections of saline or 25 mg/kg ICRF-186. ICRF-186 provided significant protection, in a dose-dependent manner, against the cardiotoxicity and nephrotoxicity of doxorubicin and attenuated the increases in cardiac immune effector cells (interstitial dendritic cells, cytotoxic T-helper lymphocytes and macrophages) associated with this cardiotoxicity. The results of the study were compared with those obtained with ICRF-187 under identical experimental conditions. Analysis of the cardiomyopathy scores, nephropathy scores and counts of the numbers of immune effector cells in the heart showed that, at a dose of 25 mg/kg, ICRF-186 is a somewhat less effective protectant than ICRF-187. At a dose of 12.5 mg/kg, both compounds induced generally similar degrees of protection. At a dose of 6.25 mg/kg, both had comparable, but only minimal, protective effects.

Animals↗
PubMed1994

Comparison of the protective effects of desferrioxamine and ICRF-187 against doxorubicin-induced toxicity in spontaneously hypertensive rats.

Since the iron-mediated formation of free radicals is considered to be a critical factor in the pathogenesis of the toxicity of doxorubicin (DXR), comparisons were made of the protective effects of two iron chelators, ICRF-187 and desferrioxamine (DFO), against the chronic cardiac and renal toxicity induced by DXR in spontaneously hypertensive rats (SHR). Two preparations of DFO were studied: DFO mesylate (DFO-M) and a polymeric form (DFO-P) in which DFO is conjugated to hydroxyethyl starch. Groups of 5 SHR each were given 12 weekly i.v. injections of 1 mg/kg DXR either alone or 30 min after the i.p. injection of 25 mg/kg ICRF-187, 50 mg/kg DFO-M, 50 mg/kg DFO-P, or 100 mg/kg DFO-P. A semiquantitative assessment was made of the cardiomyopathy (Billingham scale) and nephropathy. Renal protection was minimal with DFO-M and moderate with ICRF-187 and both doses of DFO-P. There was no cardiac protection with DFO-M. Both doses of DFO-P provided similar but modest degrees of cardiac protection. DXR-induced mortality was not prevented by either preparation of DFO. ICRF-187 provided a higher degree of protection against the cardiotoxicity and the mortality induced by DXR. Since both DFO and ICRF-187 are highly efficient chelators of iron in vitro, the differences in their in vivo protective effects are thought to be related to their cellular uptake and intracellular distribution and to the relative availability of different intracellular iron pools to these agents.

Animals↗
PubMed1994

Infantile histiocytoid cardiomyopathy: three cases and literature review.

A review is presented of the clinical and cardiac morphologic findings in 50 previously reported and 3 new patients with histiocytoid cardiomyopathy. This disorder occurs in infants and small children and is characterized clinically by severe and often fatal arrhythmias and morphologically by focal collections of altered myocytes that are roundshaped and resemble histiocytes. Sixteen patients had yellowish nodules on the endocardium, epicardium, and/or valves; the other 37 had foci of abnormal myocytes throughout the myocardium. These cells were remarkably similar in all patients and had poorly developed or absent intercellular junctions, few or no contractile elements, and markedly increased numbers of mitochondria, which imparted a granular or vacuolated appearance to the cytoplasm. There was a high prevalence of anomalies involving the nervous system and eyes and of oncocytic cells in various glands. Evidence is presented to exclude the possibilities that the disorder represents a developmental anomaly of the atrioventricular conduction system, a multifocal tumor of Purkinje cells, a developmental arrest of cardiac myocytes, and a diffuse type of mitochondrial cardiomyopathy. Histiocytoid cardiomyopathy is considered to be the result of hamartoma-like aggregations of cardiac myocytes with features similar to those of oncocytes. This syndrome is likely caused by prenatal myocardial or systemic (viral?) injury. Surgical excision of nodules of histiocytoid cells can result in clinical remission.

Cardiomyopathies↗
PubMed1994

In vitro culture of cardiac mast cells from mice experimentally infected with Trypanosoma cruzi.

In this study we describe a mast cell population obtained by in vitro culture of hearts of Trypanosoma-cruzi-infected mice. Heart tissue was placed in culture and observed daily for the efflux of cells. Mast cells appeared in the medium during the 1st week of culture in the area immediately surrounding the tissues and increased in numbers over time. The cells were identified as mast cells by electron microscopy and by positive staining of granules with Giemsa, toluidine blue, and berberine sulfate techniques. Histopathological analysis of the cultured heart fragments from infected mice showed numerous mast cells, located mostly in areas where the histologic structure was abnormal and surrounded by fibrous connective tissue. This is the first report on in situ proliferation and migration of mast cells form inflamed heart tissues. In situ grown mast cells might be useful in developing in vitro models to study the role of these cells in T. cruzi-induced and other myocardiopathies.

Animals↗
PubMed1994

Expression and subcellular distribution of basic fibroblast growth factor are regulated during migration of endothelial cells.

Migration of endothelial cells is involved in normal and pathological angiogenesis and in re-endothelialization after vascular injury or rupture of atherosclerotic plaques. Several types of endothelial cells are known to synthesize basic fibroblast growth factor (bFGF); in some of these, migration is increased by exogenous bFGF and inhibited by anti-bFGF antibodies. Using immunocytochemical techniques and RNase protection analysis, we studied endothelial cells from bovine coronary arteries and veins as well as from adrenal microvessels. We found that bFGF mRNA and peptide were present in confluent endothelial cells and were upregulated during migration stimulated by removal of some cells from the monolayer. During migration, extracellular matrix stores of bFGF were depleted, and bFGF immunoreactivity began to accumulate in the cytoplasm of endothelial cells between 2 and 6 hours. After migration had begun, but before the initiation of DNA synthesis, bFGF immunoreactivity increased in the nuclei and nucleoli. Exogenous bFGF stimulated endothelial migration, and antibodies to bFGF markedly inhibited migration, suggesting that an intracrine function of nuclear bFGF is not sufficient for cell migration. In all three types of endothelial cells studied, bFGF was identified as an endogenous regulator, but not as the sole regulator, or migration. Moreover, bFGF expression and subcellular localization were found to be regulated during endothelial cell migration.

Animals↗
PubMed1994

Myocardial changes in acute Trypanosoma cruzi infection. Ultrastructural evidence of immune damage and the role of microangiopathy.

Histological and ultrastructural studies of the hearts of dogs sacrificed 18 to 26 days after intraperitoneal inoculation with 4 x 10(5) blood forms of the 12 SF strain of Trypanosoma cruzi/kg of body weight disclosed myocarditis characterized by parasitic invasion of some myocytes, damage and necrosis of nonparasitized myocytes, and interstitial infiltration by mononuclear cells. Nonparasitized myocytes showed alterations ranging from mild edema to severe myocytolysis. These changes often were accompanied by contacts of myocytes with lymphocytes (both granular and agranular) and macrophages. These contacts were characterized by focal loss of the myocyte basement membrane and close approximation of the plasma membranes of the two cells. Contacts between lymphocytes and capillary endothelial cells were also frequent. Platelet aggregates and fibrin microthrombi were observed in some capillaries. Our findings suggest that immune effector cells play a major role in the pathogenesis of the myocyte damage and the microangiopathy in acute Chagas' disease.

Animals↗