Activation and control mechanisms of Hageman factor-dependent pathways of coagulation, fibrinolysis, and kinin generation and their contribution to the inflammatory response

The Arthus reaction in cats deficient in Hageman factor (factor XII)

A study was made of the Arthus reaction in an animal model of Hageman-factor deficiency, namely Hageman trait cats, and in control cats with normal Hageman-factor activity. At three time points, there was a significant decrease (P less than 0.01) in the size of the cutaneous Arthus reaction to chicken red blood cells in biopsies from Hageman trait cats compared with the reaction in biopsies from control animals. Injection of a positive control, histamine, and a negative control, phosphate-buffered saline, produced no significant differences between the two groups. Hageman trait cats had a significant decrease (P less than 0.001) in the number of neutrophils in the skin lesions compared with controls. When Hageman trait cats were injected intravenously with purified cat Hageman factor, Arthus reactions were similar to those observed in control cats.

Local abnormalities in coagulation and fibrinolytic pathways predispose to alveolar fibrin deposition in the adult respiratory distress syndrome

To determine the possible mechanism(s) promoting alveolar fibrin deposition in the adult respiratory distress syndrome (ARDS), we investigated the initiation and regulation of both fibrinolysis and coagulation from patients with ARDS (n = 14), at risk for ARDS (n = 5), and with interstitial lung diseases (ILD) (n = 8), and normal healthy individuals (n = 13). Bronchoalveolar lavage (BAL) extrinsic pathway inhibitor activity was increased in ARDS BAL compared with patients at risk for ARDS (P = 0.0146) or normal controls (P = 0.0013) but tissue factor-factor VII procoagulant activity was significantly increased in ARDS BAL compared with all other groups (P less than 0.001). Fibrinolytic activity was not detectable in BAL of 10 of the 14 patients with ARDS and low levels of activity were found in BAL of the other four ARDS patients. Depressed fibrinolysis in ARDS BAL was not due to local insufficiency of plasminogen; rather, there was inhibition of both plasmin and plasminogen activator. Plasminogen activator inhibitor 1 was variably detected and low levels of plasminogen activator inhibitor 2 were found in two ARDS BAL samples, but plasminogen activator inhibitor 2 was otherwise undetectable. ARDS BAL antiplasmin activity was, in part, due to alpha 2-antiplasmin. We conclude that abnormalities that result in enhanced coagulation and depressed fibrinolysis, thereby predisposing to alveolar fibrin deposition, occur in the alveolar lining fluids from patients with ARDS.

Cytokines and inflammation: modified "Miles-Wilhelm" criteria for assessing the likely roles of these substances in vivo

Cytokines (including lymphokines, interleukins, tumour necrosis factors, interferons and hemopoietic colony-stimulating factors) are a loose group of endogenous proteins which are presently being investigated for an increasingly wide range of bioactivities. Recently, cytokines have been suggested to mediate various aspects of inflammation, but the data on which these suggestions are based are often fragmentary and derive from limited experimental in vitro and in-vivo models of inflammation. Therefore, the roles of cytokines in the mediation of naturally occurring inflammatory lesions in man and animals remain unclear. This article traces the development of notions of endogenous mediators of inflammation over the last hundred years and reviews previously published ways of assessing the relevance of experimental data concerning mediators of inflammation to naturally occurring inflammatory lesions. Emphasis is given to the "criteria" advanced for this purpose by Miles and Wilhelm in the 1950s and 1960s, and additional criteria appropriate to the assessment of data concerning cytokines as mediators of inflammation are discussed.

Effects of fibrinogen derivatives upon the inflammatory response. Studies with human fibrinopeptide B

Fibrin formation and turnover are intimately associated with inflammation and wound healing. To explore whether fibrin(ogen)-derived peptides exert direct effects upon cells involved in inflammation and tissue repair we examined the capacity of human fibrinopeptide B (hFpB), a thrombin-derived proteolytic cleavage product of the fibrinogen B beta-chain, to stimulate neutrophils (PMN), monocytes, and fibroblasts. hFpB caused directed cell migration of PMN and fibroblasts that was optimal at approximately 10(-8) M. This chemotactic activity was blocked by preincubating hFpB with antiserum to hFpB. hFpB was not chemotactic for monocytes. The chemotactic potency of hFpB for PMN was equivalent to that of anaphylatoxin from the fifth component of human complement (C5a), leukotriene B4 (LTB4), and formyl-methionyl-leucyl-phenylalanine (fMLP), and for fibroblasts its chemotactic activity was comparable to that of platelet-derived growth factor. hFpB did not interact with PMN receptors for C5a, LTB4, or fMLP as (a) desensitization with 10(-7) M hFpB abolished chemotaxis to hFpB but had no effect upon chemotaxis to C5a, LTB4, or fMLP and (b) induction of chemotactic responses to fMLP and LTB4 in neutrophilic leukemic cells (HL-60 cells) by incubation with dimethylsulfoxide did not extend to hFpB. Like fMLP, hFpB caused a rapid, dose-dependent increase in PMN cytoskeletal associated actin, but unlike fMLP, hFpB did not cause PMN aggregation, release of lysosomal enzymes (lysozyme and beta-glucuronidase), or the production of superoxide anion. These results suggest that hFpB may have a role in recruiting PMN and fibroblasts at sites of fibrin deposition and turnover. The capacity of hFpB to cause PMN chemotaxis without causing concurrent release of lysosomal enzymes or the production of superoxide anion is further evidence for the complexity of PMN responses to chemotactic agents.

Inflammation and mediators of lung injury

This article covers the major pathways involved in acute inflammation in mammals with a particular emphasis on their relevance to the bovine species. It focuses on the potential and proven contributions of these systems to pulmonary defense mechanisms and lung pathology. The article also points out what is known and where gaps in our information exist as well as promising areas for research in the coming years.

In vitro inhibition of the activation of the human complement and coagulation systems by chloroquine

The ability of chloroquine to inhibit the activation of the complement and coagulation systems was investigated. The activation of the classical pathway of complement by antibody coated sheep erythrocytes and aggregated IgG was blocked by chloroquine. Similarly, it prevented normal rabbit erythrocytes and zymosan from activating the the alternative pathway of complement. The activation of C3 by immune complexes of different solubilities also was inhibited by this drug. In addition, it abrogated the clotting of plasma by calcium chloride and thrombin. This effect could be reversed by the addition of excess thrombin but not of calcium chloride. It is suggested that the inhibition of these two important phlogistic mediator systems of inflammation may contribute to the anti-inflammatory property of chloroquine.

Fibrinogen enhances complement-mediated augmentation of retention of polymorphonuclear leukocytes by nylon columns

Retention of polymorphonuclear leukocytes (PMN) by nylon columns is significantly increased when PMN are suspended in zymosan-activated plasma. In zymosan-activated plasma, 25.8 +/- 4.9% of PMN were retrained as compared with 11.1 +/- 2.7% suspended in zymosan-activated serum (ZAS) (P = 0.001) and 7.9 +/- 3.2% in fresh serum (P = 0.0005). Addition of heated plasma (56 degrees C for 30 min) to ZAS restored optimal retention. These results suggested a role for a heat-stable factor(s) in plasma, which augmented complement-mediated enhancement of PMN adhesiveness. This study was designed to determine whether fibrinogen enhanced retention by nylon columns of PMN in the presence of activated complement. Addition of defibrinated plasma to ZAS failed to enhance adhesiveness to nylon. The retention of PMN suspended in ZAS was 11.1 +/- 2.7%, as compared with 10.5 +/- 3.7% in ZAS plus defibrinated plasma. Retention of PMN suspended in ZAS plus fibrinogen was 27.92 +/- 13.2% as opposed to 16.35 +/- 7.5% (P = 0.045) in ZAs. In contrast, retention of cells in serum was 12.96 +/- 7.5%. These results suggest that the process which enhances PMN adhesiveness involves the interaction of cells, activated complement, and fibrinogen.

Fibrinolytic enzyme in tracheobronchial secretion of rats: existence of plasminogen activator

It is known that a plasminogen activator exists in the secretion of various organs, i.e., the existence of plasminogen activator in milk, tears, saliva, seminal fluids, urine and bile has been already demonstrated. However, the existence of the fibrinolytic enzyme in tracheobronchial secretions has not been known until this time. We found a new method to collect the tracheobronchial secretion of rats, and succeeded in detecting the fibrinolytic activity in the tracheobronchial secretions. Furthermore, it was found that the substance exhibiting the fibrinolytic activity in this secretion was not protease but plasminogen activator. In addition, some chemical properties of this plasminogen activator are presented, and the physiological and pathophysiological significances of it are discussed in this paper.

Cutaneous infections and disorders of inflammation

In 1908, the Nobel Prize in Physiology and Medicine was shared by Elie Metchnikoff and Paul Ehrlich. Their joint commendation acknowledged the vigorous debate which then existed and, in a sense, paved the way for our modern recognition that both cellular and humoral mechanisms might participate in immunity. Of Ehrlich's and Metchnikoff's many accomplishments, those concerning the basic nature of the inflammatory reaction suggested a clinical potential that has been realized only in the last decade. Central to their theories was the implication that normal inflammatory processes were of benefit to the host and that disordered inflammation was likely to lead to disease. Over the past decade or so, we have recognized an extensive set of diseases associated with primary or acquired deficiencies of inflammation, thus beginning to catch up to the genius of Ehrlich and Metchnikoff. Most, if not all, of these disorders demonstrate major cutaneous involvement in their clinical and biologic presentations. It is thus of essential importance that the dermatologist be familiar with this fascinating spectrum of disease, and it is to this end that this review is directed.

Fibrin deposition and clearance in chronic granulomatous inflammation: correlation with T-cell function and proteinase inhibitor activity in tissue

Patterns of fibrin deposition were investigated by immunofluorescence microscopy in livers of thymus intact (TI) and athymic (AT) mice infected with Schistosoma mansoni. Thrombin and fibrinolysis inhibitor activity in tissue extracts also were measured. In TI mice fibrin was detected perivascularly by 6 weeks after infection and at 8 weeks it was found over the granulomas as they developed. Fibrin was cleared from the center of granulomas by 10 weeks. Thrombin inhibitor activity increased at 4 to 6 weeks but declined below control levels later as granulomas formed. Fibronolysis inhibitor activity, on the other hand, peaked at 9 to 12 weeks after infection. In AT mice extensive fibrin deposition was detected in the liver throughout the period when smaller and incomplete granulomas developed. Central clearing did not occur. Thrombin inhibitor activity greatly increased by 8 weeks after infection but fibrinolysis inhibitor activity remained unchanged. These findings suggest that fibrin deposition and firbinolysis are orderly events regulated in the lesions by proteinases and their inhibitors and this seems to be a general tissue reaction in the early stage of chronic granuloma formation. Since local clearance of fibrin in vivo and fibrinolysis inhibitor activity from tissue extracts studied in vitro are more evident in TI mice than in AT mice, it appears that T cell fu;ction is important in modulating the tissue response during granulomatous inflammation.

Increased plasma kallikrein activity and tumour growth suppression associated with intralesional bradykinin injections in hamsters

Daily intralesional injections of bradykinin (250 microgram) into syngeneic SV40 virus-induced fibrosarcomas in inbred hamsters for 21 days produced marked inhibition of tumour growth, marked lymphoid cell infiltration of tumours, and significant elevations in plasma kallikrein and prekallikrein activity, compared with intralesional saline injections. All tumours were of comparable size and growth rates before injections were begun. Plasma kallikrein levels of animals which received the standard tumour cell inoculum subcutaneously and did not develop tumours were elevated significantly above normal levels and above levels of animals with large tumours. Kallikrein inhibitor activity of animals which did not develop tumours was depressed below normal levels. Intralesional injections of saline produced a significantly lesser response in plasma kallikrein and plasma prekallikrein activity than was encountered with subcutaneous saline injections in normal animals. Intralesional injections of bradykinin produced a response equivalent to that encountered with subcutaneous bradykinin injections in normal animals.

Haemostatic and complement changes in a family with 'allergic' disorders

A family with allergic manifestations, haemostatic disturbances, total absence of haemolytic activity of the complement system and low IgG levels is described. It is suggested that this functional abnormality of the complement system and the decreased level of immunoglobulin G may be due to immune complex reactions.

Lymphokine-induced secretion of plasminogen activator by murine macrophages

Thioglycollate-stimulated macrophages are known to release a plasminogen activator (PA) into the medium. In this study it was investigated whether macrophages could be activated to release PA after exposure to lymphokines. Macrophage monolayers obtained by 24 h culture of proteose peptone-elicited murine exudate cells were incubated with lymphocyte culture supernatants. After 48 h the supernatants were replaced by serum-free medium and the macrophages were incubated for another 24-48 h. These supernatants were assayed for PA as measured by the lysis of 125I-labeled fibrin. The following results were obtained: (a) Supernatants of antigen or mitogen-stimulated spleen cells induced PA secretion by macrophages whereas control supernatants were ineffective. The same was found with supernatants of mitogen-stimulated lymph node cells. (b) PA secretion by macrophages seems to be induced by a rather narrow concentration range of lymphokines. (c) Lymphokine-induced PA secretion by macrophages is enhanced after phagocytosis of latex beads. The results show that PA secretion by activated macrophages can be considered as a parameter of immunoactivation.

The diversity of mast cell-derived mediators: implications for acute, subacute, and chronic cutaneous inflammatory disorders

The mast cell in tissues represents an effector cell capable of elaboration of all the essential mediators of inflammation. The effects of uncontrolled activation may be divided into pharmacologic and inflammatory phases with attendant implications for the initiation of both acute and subacute pathologic processes. The elaboration of chemical mediators by the mast cell makes it possible to recruit blood cells and proteins essential to host defense by a controlled physiologic process that can proceed without significant local tissue damage. When uncontrolled, the same potentiality can be injurious, with the nature of the clinical problem depending upon the location of the cells, the intensity of activation, and the ratio of newly generated and preformed mediators released. The evidence that the mast cell can participate in each form of immunologic reaction--immediate, immune complex, and delayed- as a primary or secondary effector cell and the diversity of its products foretell an evolving recognition of its role in host defense and tissue injury. It is pertinent to develop further methods and criteria to define the nature and extent of mast cell participation in disease processes.