Biomedical subjects

V J Ferrans

Publications and source records attributed to V J Ferrans.

At least 217 records · Page 12Linked to original sources

PubMed1986

Mechanism of the protective activity of ICRF-187 against alloxan-induced diabetes in mice.

ICRF-187, (+)-1,2-bis(3,5-dioxopiperazine-1-yl)propane, has been shown to protect against alloxan diabetes (el-Hage et al., 1981). Since alloxan-induced pancreatic beta cell damage is thought to be mediated through the generation of highly reactive oxygen radicals by a metal catalyzed reaction involving both superoxide anion and hydrogen peroxide, in the present study the protective activity of ICRF-187 was compared with that of free radical scavengers, microsomal enzyme inhibitors and chelating agents. The free radical scavengers DMSO, vitamin E and WR2721 markedly reduced alloxan-induced hyperglycemia. ICRF-187 was found not to interact with superoxide anions, and there is no evidence to indicate that any of the known biological effects of ICRF-187 are mediated through free radical scavenging activity. SKF-525 and cimetidine, known inhibitors of drug metabolizing enzymes, also protected against the diabetogenic action of alloxan. Since it was found that ICRF-187 did not alter hexobarbital sleeping time, this compound must protect by a mechanism other than microsomal enzyme inhibition. Since the chelating agents EDTA and DETAPAC were found to protect against alloxan diabetes, ICRF-187 or its hydrolytic products, which are structurally similar to EDTA, could function as chelating agents. Transitional metals such as iron, zinc and copper were found to bind preferentially to a hydrolysis product of ICRF-187. Chelation of iron by ICRF-187 or its hydrolytic products could decrease in vivo formation of reactive oxygen radicals and provide a means for protecting against chronic anthracycline cardiotoxicity and alloxan diabetes.

Alloxan↗

PubMed1986

Myocardial diseases of animals.

In this review we have attempted a comprehensive compilation of the cardiac morphologic changes that occur in spontaneous and experimental myocardial diseases of animals. Our coverage addresses diseases of mammals and birds and includes these diseases found in both domesticated and wild animals. A similar review of the myocardial diseases in this broad range of animal species has not been attempted previously. We have summarized and illustrated the gross, microscopic, and ultrastructural alterations for these myocardial diseases; and, whenever possible, we have reviewed their biochemical pathogenesis. We have arranged the myocardial diseases for presentation and discussion according to an etiologic classification with seven categories. These include a group of idiopathic or primary cardiomyopathies recognized in man (hypertrophic, dilated, and restrictive types) and a large group of secondary cardiomyopathies with known causes, such as inherited tendency; nutritional deficiency; toxicity; physical injury and shock; endocrine disorders, and myocarditides of viral, bacterial, and protozoal causation. Considerable overlap exists between each of the etiologic groups in the spectrum of pathologic alterations seen in the myocardium. These include various degenerative changes, myocyte necrosis, and inflammatory lesions. However, some diseases show rather characteristic myocardial alterations such as vacuolar degeneration in anthracycline cardiotoxicity, myofibrillar lysis in furazolidone cardiotoxicity, calcification in calcinosis of mice, glycogen accumulation in the glycogenoses, lipofuscinosis in cattle, fatty degeneration in erucic acid cardiotoxicity, myofiber disarray in hypertrophic cardiomyopathy, and lymphocytic inflammation with inclusion bodies in canine parvoviral myocarditis. The myocardial diseases represent the largest group in the spectrum of spontaneous cardiac diseases of animals. Pericardial and endocardial diseases and congential cardiac diseases are seen less frequently; and, in contrast to man, coronary artery disease and myocardial ischemia are rather infrequent in animals. The present review shows clearly that the spectrum of myocardial diseases in animals is enlarging and that many newly recognized diseases are emerging and assuming considerable importance. For example, various heritable cardiomyopathies have recently been described in the KK mouse, cattle, and rats. Increasingly recognized myocardial diseases include cardiomyopathies in cats, dogs, and birds; anthracycline cardiotoxicity; furazolidone cardiotoxicity; ionophore cardiotoxicity; myocardial damage associated with central nervous system injuries; myocardial hypertrophy in

Animals↗

PubMed1986

Intraluminal fibrosis in interstitial lung disorders.

The histopathologic and ultrastructural features of intraluminal organizing and fibrotic changes were studied in open lung biopsies and autopsy specimens from 373 patients with interstitial lung disorders, including hypersensitivity pneumonitis (n = 44), idiopathic pulmonary fibrosis (n = 92), collagen-vascular diseases (n = 20), chronic eosinophilic pneumonia (n = 10), pulmonary histiocytosis X (n-90), pulmonary sarcoidosis (n = 62), pneumoconioses (n = 25), Legionnaire's disease (n = 5), drug- and toxin-induced pneumonitis (n = 4), radiation-induced pneumonitis (n = 2), lymphangioleiomyomatosis (n = 11), and chronic organizing pneumonia of unknown cause (n = 8). Three patterns of intraluminal organization and fibrosis were recognized: 1) intraluminal buds, which partially filled the alveoli, alveolar ducts and/or distal bronchioles; 2) obliterative changes, in which loose connective tissue masses obliterated the lumens of alveoli, alveolar ducts or distal bronchioles, and 3) mural incorporation of previously intraluminal connective tissue masses, which fused with alveolar, alveolar ductal, or bronchiolar structures and frequently became reepithelialized. All three patterns had common morphologic features, suggesting that, regardless of their severity, they resulted from a common pathogenetic mechanism, ie, the migration of activated connective tissue cells, through defects in the epithelial lining and its basement membrane, from the interstitial into the intraluminal compartment. Intraluminal buds were observed most frequently in hypersensitivity pneumonitis, chronic eosinophilic pneumonia, and organizing pneumonia of unknown cause. Mural incorporation and, to a lesser extent, obliterative changes were observed in most interstitial disorders and were very prominent in idiopathic pulmonary fibrosis. Mural incorporation and obliterative changes play an important role in pulmonary remodeling, especially when several adjacent alveoli and/or other air spaces are involved. Under these circumstances, intraluminal organization can mediate the fusion of adjacent alveolar structures by intraluminal connective tissue.

Alveolitis, Extrinsic Allergic↗

PubMed1985

Effect of ibuprofen on the healing phase of experimental myocardial infarction in the rat.

The healing phase of acute myocardial infarction (AMI) is initiated by proteolysis of necrotic myocardium, followed by infiltration of fibroblasts and deposition of collagen. To assess whether ibuprofen, a potent antiinflammatory agent, preserves existing collagen and enhances deposition of new collagen during infarct healing, biochemical and morphologic studies were made of experimentally induced myocardial infarcts in untreated rats and in rats treated with ibuprofen. All treated rats received 12.5 mg/kg of ibuprofen at 1, 6 and 18 hours after AMI. Group 1 rats underwent measurement of myocardial hydroxyproline (HP) content at 24 hours after AMI. Group 2 rats received ibuprofen, 12.5 mg/kg, twice a day for 2 additional days, with measurement of myocardial HP at 3 days (group 2a) or 21 days (group 2b) after AMI. Group 3 rats received ibuprofen, 12.5 mg/kg, twice a day for 6 additional days with measurement of HP content, or infarct size and degree of thinning at 21 days after AMI. Compared with untreated rats, ibuprofen-treated rats had significantly greater amounts of HP in the infarct at 24 hours (group 1, 8.9 +/- 2.2 nmol/mg dry weight vs untreated, 7.1 +/- 2.8 nmol/mg dry weight, p less than 0.04) and at 21 days (group 2b, 112 +/- 37 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.05, and group 3, 125 +/- 51 nmol/mg dry weight vs untreated, 91 +/- 39 nmol/mg dry weight, p less than 0.003). Substantial scar thinning was noted in all rats; no difference in scar thinning was noted between treated and untreated rats at 21 days after AMI.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Cardiovascular lesions in collagen-vascular diseases.

In this review, the cardiac lesions which develop in association with the various collagen-vascular diseases are described. In rheumatoid arthritis, the most frequent lesions are: fibrous obliterative pericarditis, with pericardial deposits of calcium, fibrin, cholesterol, and rheumatoid granulomas; granulomatous or nonspecific myocarditis; valvulitis, vasculitis, and amyloid deposits. In ankylosing spondylitis, the lesions involve mainly the valves (aortic and mitral valves) and the aorta. In systemic lupus erythematosus, the predominant cardiovascular lesions are: pericarditis, Libman-Sacks endocarditis, nonspecific myocarditis, vasculitis with fibrinoid necrosis, and acceleration of atherosclerosis. In scleroderma, the main cardiac lesion is fibrosis with only scanty inflammatory cells; pericarditis and nonbacterial thrombotic endocarditis also occur. In dermatomyositis/polymyositis, fibrous or fibrinous pericarditis can occur, as well as myocarditis with infiltrates of lymphocytes and plasma cells and with degeneration and necrosis of myocytes; valvulitis is uncommon except when the disease is related to mucinous adenocarcinoma. In polyarteritis nodosa, various stages of necrotizing vasculitis involve all layers of the arterial walls; foci of myocardial necrosis of various sizes can occur in association with these lesions; cardiac hypertrophy related to hypertension and pericarditis related to uremia, may also be found. In Wegener's granulomatosis, pericarditis, inflammatory infiltrates, necrotizing granulomas, and vasculitis have been observed in the heart.

Animals↗

PubMed1985

Granulomatous inflammation of the heart.

Morphologic characteristics of granulomatous inflammation in the heart and pericardium are discussed. In rheumatic fever, two types of myocardial lesion are present--a nonspecific myocarditis and a specific lesion characterized by granulomas known as Aschoff's nodules. The latter undergo a cycle of development and resolution; in their mature stage, they contain Aschoff's cells which are uni- or multinucleated histiocytes with a serrated nuclear chromatin bar. Ultrastructural studies do not suggest a relationship between these cells and cardiac or smooth muscle cells. In metabolic disorders, granulomas occur in Farber's disease (lipogranulomatosis), gout (in which tophi are associated with calcific deposits and with a foreign body cellular reaction), the various syndromes of oxalosis (in which oxalate deposits also lead to a foreign body reaction), and in chronic granulomatous disease of childhood. Foreign body giant-cells can also be found in association with calcification of necrotic myocytes and in the syndromes of "cholesterol pericarditis." Well-developed granulomas occur in sarcoidosis, giant cell myocarditis, as a reaction to foreign bodies and devices implanted within the cardiovascular system, and in certain diseased caused by infective agents (tuberculosis, fungal and parasitic disorders). Infiltration of the heart by nongranulomatous masses of histiocytes can occur in Whipple's disease, Niemann-Pick disease, the hyperlipoproteinemias, Gaucher's disease, and in proliferative disorders of the mononuclear phagocyte system (juvenile xanthogranuloma, Chester-Erdheim syndrome, and malignant histiocytosis).

Cardiomyopathies↗

PubMed1985

Cardiac lesions of selenium-vitamin E deficiency in animals.

Necrosis of myocardium and skeletal muscle is a consistent finding in the numerous animal species in which spontaneous or experimental selenium-vitamin E (Se-E) deficiency has been described. Etiologic factors in the development of these lesions include: low dietary levels of Se, vitamin E, and sulfur-containing amino acids; high dietary concentrations of polyunsaturated fats; exposure to prooxidant conditions (toxicity by O2, O3, Fe, doxorubicin, and radiation injury); and intake of Se antagonists (Ag, Cu, Co, Cd, Te, Sb, and Zn). Myocardial lesions in Se-E deficient animals are most frequently seen in calves, lambs, turkey poults, and ducklings. In calves and lambs with cardiac lesions, the clinical finding usually is sudden death after vigorous exercise. At necropsy, affected calves have areas of necrosis and calcification in the left ventricular free wall and ventricular septum, while in lambs these lesions are seen in the right ventricular subendocardium. Histologically, areas of myocardial damage have hyaline necrosis with or without calcification, subsequent macrophagic invasion, and eventual fibrosis. In growing pigs, the hearts may have scattered pale streaks in the ventricular myocardium, but the most striking alterations are widespread epicardial and myocardial hemorrhages ("mulberry heart"). Histologically, both vascular and myocyte lesions are present. Vascular changes include fibrinoid necrosis of small arteries and arterioles and fibrin microthrombi in capillaries. The myocyte lesions in pigs and in birds consist of multifocal hyaline necrosis with calcification, followed by macrophagic invasion and fibrosis. Ultrastructural study of these lesions reveals myocyte alterations, which include mitochondrial swelling and mineralization, myofibrillar lysis, and necrosis with contraction bands.

Animals↗

PubMed1985

Comparison of the severity of the chronic cardiotoxicity produced by doxorubicin in normotensive and hypertensive rats.

A comparison was made of the severity of chronic doxorubicin cardiotoxicity in adult male spontaneously hypertensive rats (SHR) and in genetically related normotensive Wistar-Kyoto rats (WKY). Groups of SHR and WKY were given 12 weekly iv injections of doxorubicin at 0.25, 0.5, or 1.0 mg/kg. When the study was concluded, mean arterial pressure was 127 to 161 nm Hg in doxorubicin-treated SHR compared with 74 to 87 mm Hg in similarly treated WKY. Lesions, consisting mainly of cytoplasmic vacuolization and myofibrillar loss, were noted in the hearts from both types of rats given the 1.0-mg/kg dose and were considerably more severe in SHR than in WKY (average scores 3.8 and 2.0). Renal lesions (glomerular vacuolization and dilatation of tubules with accumulations of proteinaceous material) were of comparable severity in both types of rats at the 9- and 12-mg/kg cumulative doses; however, they were more severe in SHR at the 6-mg/kg cumulative dose. Moderate cardiac alterations were present in all SHR (average score 1.6) given 0.5 mg doxorubicin/kg; at the same dose, lesions were minimal in two and absent in three WKY. In a second study, groups of rats were killed 1 week after 3,6,9, or 12 weekly iv injections of doxorubicin (1.0 mg/kg). Myocardial lesions were noted initially in SHR after six doses and in WKY after nine doses. Three of five SHR were dead by the 12th dose. These results indicate that spontaneously hypertensive rats are much more sensitive than normotensive rats to the cardiotoxic effects of doxorubicin.

Animals↗

PubMed1985

Influence of the diabetic state on isoproterenol-induced cardiac necrosis.

Isoproterenol-induced myocardial necrosis was examined in male mice with alloxan-induced and genetically transmitted diabetes. Ten days after alloxan treatment, mice exhibited an elevation in blood glucose concentrations, weight loss, polyuria and decreased heart rates (510 +/- 15 v. 675 +/- 11 beats/min) compared with matched control mice. Similarly, genetically diabetic mice exhibited lower heart rates than the corresponding age-matched controls (383 +/- 30 v. 603 +/- 30 beats/min). In comparison to matched controls, both groups of diabetic mice had a significant decrease in the severity of the cardiac necrosis which was induced by the administration of isoproterenol. The reduction in isoproterenol-induced cardiac lesions was similar in mice with chemically induced diabetics and mice with genetically transmitted diabetes. Biochemical studies of ventricular slices revealed no change in basal cAMP levels and no differences in isoproterenol-induced changes in cAMP levels in mouse hearts from both models of diabetes. Insulin treatment corrected the chemically induced diabetic state and restored the cardiotoxic potential of isoproterenol.

Animals↗

PubMed1985

Transcatheter ablation: comparison between laser photoablation and electrode shock ablation in the dog.

To characterize and compare the effects of transcatheter laser and electrical energy on endocardium, 35 laser pulses were delivered to the endocardial surfaces of isolated canine hearts, and 33 endocardial lesions were produced by the transarterial delivery of either transcatheter laser irradiation or electrical shock in closed-chest anesthetized dogs. Laser-induced lesion dimensions in vitro and in vivo increased with increased total dose of energy; however, the lesions produced in vivo were different in morphology and were significantly larger than lesions produced by equivalent doses of energy delivered in vitro (p less than .05). Endocardial lesions produced in vivo by laser at 40 and 80 J (7.9 X 5.4 X 6.6 and 7.9 X 5.1 X 7.5 mm) were comparable in gross morphology and size to those produced by electrical shock at 100 and 200 J (8.5 X 6.6 X 6.6 and 10.0 X 8.5 X 8.2 mm, respectively; p = NS), but transcatheter electrode shock produced significantly more ventricular tachycardia (p less than .003), premature ventricular beats in the 7 min after energy discharge (p less than .05), and wall motion abnormality (p less than .005). Transcatheter laser photoablation can create controlled endocardial lesions with less energy and fewer deleterious effects than transcatheter electrode shock.

Animals↗

PubMed1985

Experimental polymyxin B-induced interstitial lung disease characterized by an accumulation of cytotoxic eosinophils in the alveolar structures.

A variety of lung disorders are associated with the accumulation of eosinophils in the alveolar structures. To help understand the role of eosinophils in these disorders, an animal model of eosinophilic lung disease was developed. Administration of an aerosol of polymyxin B to guinea pigs (3 times per wk for 4 wk) produced diffuse interstitial lung disease with alveolar wall thickening and an alveolitis characterized by marked increases in eosinophils and alveolar macrophages. Bronchoalveolar lavage confirmed the presence of significantly increased numbers of eosinophils and alveolar macrophages in polymyxin-B-treated animals compared with those in control animals. Using density gradient centrifugation, approximately 10(7) eosinophils could be purified from the lungs of a single polymyxin-B-treated animal. Importantly, eosinophils purified from the lungs from polymyxin B-treated animals exhibited significant spontaneous cellular cytotoxicity for human fetal lung fibroblasts. In contrast, neither eosinophils from control animals nor alveolar macrophages from either group of animals were cytotoxic. These findings demonstrate that eosinophils possess effector processes capable of injuring the lung parenchyma and suggest that eosinophils can contribute to the pathogenesis of the interstitial lung disease.

Aerosols↗

PubMed1985

Motheaten mice--an animal model with an inherited form of interstitial lung disease.

The motheaten gene represents a single recessive mutation that occurs in mice and is associated with systemic immune abnormalities. Although they have abnormalities in several organs, homozygote animals (me/me) die by 8 wk of age from a diffuse, noninfectious lung disease. To evaluate this genetically determined model of interstitial lung disease, the lungs of these animals were studied by light and transmission electron microscopy and by bronchoalveolar lavage. Two control groups of mice were evaluated: (1) littermate normal mice, including mice without the motheaten gene (+/+) and mice heterozygous (me/+) the motheaten gene, and (2) nonlittermate normal mice (+/+). While the lungs of both control groups were normal morphologically, the lung disease in the homozygous motheaten mice progressed through 3 stages: (1) focal intra-alveolar hemorrhage with accumulations of alveolar macrophages and neutrophils in the lower respiratory tract; (2) persistent alveolitis and hemorrhage, and reparative processes including frequent mitoses of fibroblasts and type II alveolar epithelial cells; and (3) consolidation of the alveolar structures by massive accumulation of macrophages and marked derangement and fibrosis of the alveolar walls. Consistent with the morphologic findings, evaluation of mid-stage lung disease by lavage demonstrated that the alveolitis was characterized by a marked expansion of the total number of effector cells, an accumulation of neutrophils, and a marked expansion of the total numbers of T-lymphocytes and B-lymphocytes. Thus, the motheaten mouse can be regarded as a genetically determined model of interstitial lung disease characterized by alveolar hemorrhage, derangement of parenchymal cells, fibrosis, and an alveolitis with distinctive features.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Evidence for chronic inflammation as a component of the interstitial lung disease associated with progressive systemic sclerosis.

Progressive systemic sclerosis (PSS) is a generalized disorder characterized by fibrosis of many organs including the lung parenchyma. Unlike most other interstitial disorders, traditional concepts of the interstitial lung disease associated with PSS have held it to be a "pure" fibrotic disorder without a significant inflammatory component. To directly evaluate whether an active alveolitis is associated with this disorder, patients with chronic interstitial lung disease and PSS were studied by open lung biopsy, gallium-67 scanning, and bronchoalveolar lavage. Histologic evaluation of the biopsies demonstrated that the interstitial fibrosis of PSS is clearly associated with the presence of macrophages, lymphocytes, and polymorphonuclear leukocytes, both in the interstitium and on the alveolar epithelial surface. Gallium-67 scans were positive in 77% of the patients, showing diffuse, primarily lower zone uptake, suggestive of active inflammation. Consistent with the histologic findings, bronchoalveolar lavage studies demonstrated a mild increase in the proportions of neutrophils and eosinophils with occasional increased numbers of lymphocytes. Importantly, alveolar macrophages from patients with PSS showed increased release of fibronectin and alveolar-macrophage-derived growth factor, mediators that together stimulate lung fibroblasts to proliferate, thus suggesting at least one mechanism modulating the lung fibrosis of these patients. Thus, evidence from several different points of view together demonstrates that the interstitial lung disease associated with PSS is associated with chronic inflammation in the local milieu, leading to the hypothesis that the inflammation plays some role in the derangements to the alveolar structures that characterize this disorder.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1985

Immunocytochemical characterization of pulmonary histiocytosis X cells in lung biopsies.

Morphologic and immunohistochemical studies were made of open lung biopsies from 9 patients with pulmonary histiocytosis X (HX) and 12 patients with other conditions, and of skin biopsies from patients with cutaneous sarcoidosis, Chester-Erdheim disease, and eruptive histiocytoma. The monoclonal antibody OKT6 was detected with the use of goat anti-mouse IgG labeled with fluorescein (FITC) for light microscopy, and sheep antimouse Fab'2 fragment of IgG labeled with horseradish peroxidase (HRP) for immunoelectron microscopy. The presence of S-100 protein was revealed by an antibody prepared against bovine S-100 protein, using sheep anti-rabbit IgG labeled with FITC for light microscopy and with HRP for immunoelectron microscopy. OKT6 antibody and S-100 protein were detected simultaneously by double labeling with FITC and rhodamine. In all patients with pulmonary HX, the major cellular components (HX cells) of the granulomas showed labeling of the plasma membranes by OKT6 and of the cytoplasm by the anti S-100 protein antibody. The double-labeling technique demonstrated that the same cells carried both reactivities. Immunoelectron microscopy showed that the reactive cells had all the structural characteristics of Langerhans cells, including Langerhans cell granules. Cells reacting with OKT6 showed discrete internal labeling in some of the Langerhans granules, especially those in continuity with the plasma membranes. However, internal labeling of Langerhans granules was not demonstrated in preparations for the localization of S-100 protein. Control samples of sarcoid lesions and other pulmonary lesions unrelated to HX did not show any reactivity except in Langerhans cells; a skin lesion from a patient with eruptive histiocytoma contained OKT6-positive cells which did not have Langerhans granules.

Antibodies, Monoclonal↗

PubMed1985

The relative influence of arterial pressure versus intraoperative distention on lipid accumulation in primate vein bypass grafts.

Atherosclerotic degeneration has been well documented to be the limiting factor for long-term function of aortacoronary vein bypass grafts. Injury, including that induced by pressure distention in preparation for grafting, is thought to play a role in this degeneration. Injury can be minimized by limiting the distending pressure, but vein grafts are chronically subjected to arterial pressures that far exceed native venous pressure. We evaluated the relative influence of arterial pressure and of higher pressure of distention on cholesterol and apolipoprotein-B accumulation by grafts in our established animal model of graft atherogenesis. Grafts were interposed in the femoral arteries of eight normolipemic stump-tailed macaque monkeys. Before insertion, each vein was distended at 125 mm Hg (arterial pressure) for 1 minute with autologous blood, followed by distention of one half of the vein at 350 mm Hg for 1 additional minute. Grafts and ungrafted control vein were removed 3 months later. Cholesterol concentration in grafts distended at 125 mm Hg was 213% (p less than 0.01) and apolipoprotein-B concentration was 430% (p less than 0.001) of that in ungrafted control veins, whereas in grafts distended at 350 mm Hg cholesterol was 250% (p less than 0.01) and apolipoprotein-B was 925% (p less than 0.001) of the control concentrations. Although morphologic differences between the two groups of grafts were less profound than biochemical differences, foam cells were observed more frequently in grafts distended at 350 mm Hg than in those distended at 125 mm Hg. These data demonstrate that chronic exposure to arterial pressure has a significant effect on graft cholesterol that is proportionally greater than that caused by intraoperative distention at moderate pressure. Nevertheless, the detrimental effects of excessive distending pressures should not be ignored.

Animals↗

PubMed1985

Patterns of pulmonary structural remodeling after experimental paraquat toxicity. The morphogenesis of intraalveolar fibrosis.

For a study of the evolution of interstitial and intraalveolar fibrosis, ultrastructural and immunohistochemical observations were made of the lungs of 16 cynomolgous monkeys given 1 or 2 injections of 10 mg/kg of paraquat and sacrificed 2 days to 8 weeks later. At 2-3 days, alveolar epithelial cells were denuded in many areas, and fibronectin was conspicuous in alveolar spaces. At 1 week, fibroblasts and inflammatory cells were migrating through gaps in the denuded epithelial basement membranes; Type II cells were regenerating in some areas. At 3-4 weeks, alveoli developing intraalveolar fibrosis contained many myofibroblasts, collagen fibrils, and small elastic fibers; fibrotic alveolar walls were lined by metaplastic squamous cells and bronchiolar epithelial cells. Spiraling collagen fibrils were found in interstitium but not in alveolar spaces, which suggests that they were formed from breakdown of collagen. Newly formed intraalveolar collagen was mainly Type I. At 8 weeks, intraalveolar fibrosis had led to extensive remodeling, with new glandlike alveoli lined by Type II cells; alveoli without intraalveolar fibrosis had more normal architecture. Thus, intraalveolar fibrosis in paraquattreated lung is mediated by intraalveolar migration of interstitial cells, through gaps in the epithelial basement membranes, after epithelial injury. This is followed by connective tissue synthesis on the luminal side of the epithelial basement membrane, by differentiation of interstitial cells into myofibroblasts and smooth-muscle cells, by incorporation of areas of intraalveolar fibrosis into the interstitium, and by coalescence of alveolar walls. Intraalveolar fibrosis is more important than interstitial fibrosis in the structural remodeling that occurs in paraquattreated lung, because it results in obliteration of alveoli, coalescence of alveolar walls, and loss of functional alveolar-capillary units.

Animals↗

PubMed1985

Immunological studies on the mechanism of halothane-induced hepatotoxicity: immunohistochemical evidence of trifluoroacetylated hepatocytes.

The fulminant hepatotoxicity caused by halothane has been thought to have an immunological basis because this toxicity occurs most often after repeated administration of halothane and because sera from patients recovering from severe halothane hepatotoxicity contain antibodies that bind to the surface membranes of hepatocytes of rabbits treated with halothane. In order to determine whether the major reactive metabolite of halothane, trifluoroacetyl halide, covalently binds to hepatocytes, we have developed specific and sensitive peroxidase enzyme-linked immunosorbent assays and an indirect immunofluorescence staining method for identifying trifluoroacetylated (TFA)-hepatocytes. Liver sections prepared from rats at 4 hr after halothane administration were stained preferentially in the centrilobular region with anti-TFA serum whereas livers of control rats showed no staining. The specificity of the assay for the TFA group was confirmed by the complete inhibition of the staining with 200 microM N-epsilon-TFA-L-lysine in the diluted antiserum. On the other hand, 2 mM halothane or L-lysine did not inhibit this staining. Moreover, treatment of rats with deuterated halothane resulted in significantly less staining than did halothane. At 24 hr after halothane administration, hepatocytes isolated and stained by indirect immunofluorescence showed a linear and granular pattern on their surface membranes. These results indicate that trifluoroacetyl halide either reacts directly with constituents of the plasma membranes or with other cellular components which become incorporated into the plasma membranes.

Animals↗

PubMed1985

Cuspal perforations caused by long suture ends in implanted bioprosthetic valves.

A description is presented of the gross anatomic, histologic, and scanning electron microscopic features of cuspal abrasions, perforations, and tears caused by excessively long ends of braided sutures in bioprosthetic cardiac valves implanted in the mitral position in sheep. These lesions are produced as consequences of contact between the ends of the sutures and the inflow surfaces of the bioprosthetic cusps, leading to a process of surface erosion that progresses to actual perforation of the cusps. The perforation has the appearance of a crater, the wider end of which faces the inflow surface and the walls of which are formed by broken ends of collagen fibrils. Suture perforations can extend to form tears that involve the free edge of the cusp and result in hemodynamically important regurgitation. Therefore, care must be taken to avoid leaving excessively long suture ends during the implantation of bioprosthetic cardiac valves.

Animals↗