fibrin and Peritonitis

Peritonitis is the most frequent complication and a leading cause of discontinuation of peritoneal dialysis (PD). Intact epithelial lining, sufficient blood flow, and adequate immunologic responses are vital to eradicate infection. In long-term PD, various pathological changes such as denudation of peritoneal mesothelial cells, duplication of submesothelial and/or capillary basement membranes, submesothelial fibrin deposit, and peritoneal fibrosis have been reported. Causes of these changes of the peritoneum are multifactorial. Commonly used dialysis solutions that are acidic, hypertonic, containing high concentrations of glucose and lactate, contaminated by glucose and/or plastic degradation products are not biocompatible and may induce chronic immune reactions in the peritoneal cavity. Long-term exposure of the peritoneum to dialysis solutions, the peritoneal catheter, and recurrent episodes of peritonitis all contribute to peritoneal injury. In addition, long-term exposure of peritoneal cells such as macrophages, mesothelial cells, and fibroblasts to dialysis solutions may also alter the normal immunologic reactions against bacteria. Peritoneal concentrations of opsonins such as Ig, complement, and protease are approximately 1% of the serum levels and far below the level sufficient to eradicate bacteria due to continuous peritoneal lavage and dilution with dialysis solutions. Furthermore, glycation of IgG induces chronic activation of macrophages and decreases normal opsonic activities against bacteria. Fibrin deposits, collagen accumulation, and cellular desert of the peritoneum observed in long-term peritoneal dialysis patients may serve as a safe shelter for bacteria from contact with inflammatory cells and opsonin and delay eradication of bacteria. In conclusion, peritonitis is often more severe in patients on long-term PD. In this setting, peritonitis needs special attention to prevent life-threatening infection and further damage of the peritoneum.

Topics: Collagen; Dialysis Solutions; Epithelium; Fibrin; Glucose; Glycosylation; Humans; Immunoglobulin G; Macrophages; Membrane Lipids; Peritoneal Dialysis; Peritoneum; Peritonitis; Phospholipids; Time Factors

Topics: Anti-Bacterial Agents; Anti-Infective Agents, Local; Diaphragm; Fibrin; Fibrinolysis; Humans; Lymph Nodes; Peritoneal Lavage; Peritoneum; Peritonitis; Phagocytosis

Drawing from diverse sources including epidemiological and clinical data, surgical observations, histopathology, serosal healing responses to fibrin and fibrinolysis, tissue reaction to chronic exposure, and to exo- and endotoxins, new information on mesothelial stem cells, autocrine and paracrine influences on their proliferation and collagen synthesis, and the effect of glucose on fibroconnective tissue, we have begun to piece together the pathogenetic jigsaw of fibrosis in continuous ambulatory peritoneal dialysis (CAPD). The reaction of peritoneal mesothelium and stroma to the stress of continual dialysis results in a spectrum of alterations ranging from opacification through a tanned peritoneum syndrome to sclerosing encapsulating peritonitis (SEP). Any agent that causes irritation of the mesothelial layer and induces serositis, or single severe or multiple episodes of peritonitis resulting in mesothelial loss, predisposes the peritoneum to fibroneogenesis. An accurate definition of the histopathological changes of peritoneal thickening is a prerequisite for defining pathogenesis. This paper is the first attempt to create such a framework. It is evident from many areas of study that fibrin deposition and fibrinolysis, hyalinization of the superficial stromal collagen possibly tanned through nonenzymatic glycosylation by dialysate glucose and the proliferative potential of mesothelial stem cells play an important and possibly interdependent role in excessive fibroneogenesis in certain patients on CAPD. Many of the pieces of the jigsaw are obviously still missing, and the picture is most surely incomplete. Nevertheless, the outline of the pathologic and etiologic landscape should now be discernible.

Topics: Acetates; Adrenergic beta-Antagonists; Anti-Infective Agents, Local; Catheters, Indwelling; Dialysis Solutions; Fibrin; Fibrinolysis; Fibrosis; Humans; Peritoneal Dialysis; Peritoneal Dialysis, Continuous Ambulatory; Peritoneum; Peritonitis; Sclerosis; Stem Cells

A multicenter randomized controlled clinical trial, which was carried out in 10 hospitals in the Federal Republic of Germany between 1979 and 1983, studied the influence of i.v. immunoglobulin G on the mortality in patients with diffuse acute fibrinopurulent peritonitis. Altogether 288 patients were enrolled in the trial. There was no statistically significant difference in the mortality rates within the treated group (46%) vs the control group (41%). The power of the statistical test to detect a decrease of the mortality by 20% was calculated to be 0.93. This result did not change when we eliminated 50 patients not strictly obeying the entrance criteria of the analysis, or when we focused on a subgroup of patients with initial deficiency of immunoglobulin G. Factors influencing mortality were a preceding laparotomy, serum creatinine level above 2 mg/100 ml, and necessity for artificial respiration. These factors, reflecting the surgical situation and the severity of shock, essentially explain the mortality differences observed between the participating hospitals.

Topics: Bacterial Infections; Clinical Trials as Topic; Fibrin; Humans; Immunoglobulin G; Peritonitis; Prognosis; Random Allocation

The blood-clotting protein fibrin(ogen) plays a critical role in host defense against invading pathogens, particularly against peritoneal infection by the Gram-positive microbe Staphylococcus aureus. Here, we tested the hypothesis that direct binding between fibrin(ogen) and S. aureus is a component of the primary host antimicrobial response mechanism and prevention of secondary microbe dissemination from the peritoneal cavity. To establish a model system, we showed that fibrinogen isolated from FibγΔ5 mice, which express a mutant form lacking the final 5 amino acids of the fibrinogen γ chain (termed fibrinogenγΔ5), did not support S. aureus adherence when immobilized and clumping when in suspension. In contrast, purified wildtype fibrinogen supported robust adhesion and clumping that was largely dependent on S. aureus expression of the receptor clumping factor A (ClfA). Following peritoneal infection with S. aureus USA300, FibγΔ5 mice displayed worse survival compared to WT mice coupled to reduced bacterial killing within the peritoneal cavity and increased dissemination of the microbes into circulation and distant organs. The failure of acute bacterial killing, but not enhanced dissemination, was partially recapitulated by mice infected with S. aureus USA300 lacking ClfA. Fibrin polymer formation and coagulation transglutaminase Factor XIII each contributed to killing of the microbes within the peritoneal cavity, but only elimination of polymer formation enhanced systemic dissemination. Host macrophage depletion or selective elimination of the fibrin(ogen) β2-integrin binding motif both compromised local bacterial killing and enhanced S. aureus systemic dissemination, suggesting fibrin polymer formation in and of itself was not sufficient to retain S. aureus within the peritoneal cavity. Collectively, these findings suggest that following peritoneal infection, the binding of S. aureus to stabilized fibrin matrices promotes a local, macrophage-mediated antimicrobial response essential for prevention of microbe dissemination and downstream host mortality.

Topics: Animals; Coagulase; Fibrin; Fibrinogen; Mice; Peritonitis; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Blood Coagulation; Coagulase; Female; Fibrin; Fibrinogen; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Peritonitis; Prothrombin; Staphylococcal Infections; Staphylococcus aureus; Thromboplastin

Peritonitis, due to a fungal or bacterial infection, leads to injury of the peritoneal lining and thereby forms a hazard for the long-term success of peritoneal dialysis (PD) and remains a lethal complication in patients with PD. This study investigated whether C1 inhibitor (C1-INH) could protect against the progression of peritoneal injuries with five daily administrations of zymosan after mechanical scraping of the rat peritoneum to mimic fungal peritonitis. Severe peritoneal injuries were seen in this model, accompanied by fibrinogen/fibrin exudation and peritoneal deposition of complement activation products such as activated C3 and C5b-9. However, intraperitoneal injection of C1-INH decreased peritoneal depositions of activated C3 and C5b-9, ameliorated peritoneal thickening, reduced the influx of inflammatory cells, and prevented the production of peritoneal fibrous layers with both one and two doses of C1-INH each day. Our results suggest that C1-INH might be useful to protect against peritoneal injuries after causes of peritonitis such as fungal infection. This clinically available agent may thus help extend the duration of PD.

Topics: Animals; Complement C1 Inhibitor Protein; Epithelial Cells; Epithelium; Fibrin; Fibrinogen; Male; Peritoneum; Peritonitis; Rats; Rats, Sprague-Dawley; Zymosan

Encapsulating peritoneal sclerosis (EPS) is a rare but serious and life-threatening complication of peritoneal dialysis (PD). However, the precise pathogenesis remains unclear; in addition, predictors and early diagnostic biomarkers for EPS have not yet to be established.. Eighty-three peritoneal membrane samples taken at catheter removal were examined to identify pathological characteristics of chronic peritoneal deterioration, which promotes EPS in patients undergoing long-term PD treatment with low occurrence of peritonitis.. According to univariable logistic regression analysis of the pathological findings, thickness of the peritoneal membrane (P = 0.045), new membrane formation score (P = 0.006), ratio of luminal diameter to vessel diameter (L/V ratio, P<0.001), presence of CD31-negative vessels (P = 0.021), fibrin deposition (P<0.001), and collagen volume fraction (P = 0.018) were associated with EPS development. In analyses of samples with and without EPS matched for PD treatment period, non-diabetes, and PD solution, univariable analysis identified L/V ratio (per 0.1 increase: odds ratio (OR) 0.44, P = 0.003) and fibrin deposition (OR 6.35, P = 0.027) as the factors associated with EPS. L/V ratio was lower in patients with fibrin exudation than in patients without fibrin exudation.. These findings suggest that damage to vascular endothelial cells, as represented by low L/V ratio, could be a predictive finding for the development of EPS, particularly in long-term PD patients unaffected by peritonitis.

Topics: Adult; Blood Vessels; Catheters, Indwelling; Device Removal; Endothelial Cells; Female; Fibrin; Humans; Male; Middle Aged; Peritoneal Dialysis; Peritoneal Fibrosis; Peritoneum; Peritonitis

In experiment on rabbits a comparative analysis of various methods of a biliary peritonitis simulation was conducted. In 6 animals a biliary peritonitis was simulated, using perforation of a gallbladder, local serous-fibrinous peritonitis have occurred in 50% of them. In 7 animals biliary peritonitis was simulated, applying intraabdominal injection of medical sterile bile in a 5-40 ml volume. Diffuse peritonitis with exudates and stratification of fibrin was absent. Most effective method have appeared that, when intraabdominal injection of bile was done together with E. coli culture in the rate of 0.33 microbal bodies McF (1.0 x 10(8) CFU/ml) on 1 kg of the animal body mass. Diffuse biliary peritonitis have occurred in all 23 animals, including serous-fibrinous one--in 17 (76%), and purulent-fibrinous--in 6 (24%).

Topics: Animals; Bile; Colony Count, Microbial; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Exudates and Transudates; Fibrin; Humans; Peritonitis; Rabbits; Severity of Illness Index

Carboxypeptidase B2 (CPB2) is a basic carboxypeptidase with fibrin and complement C3a and C5a as physiological substrates. We hypothesized that in polymicrobial sepsis, CPB2-deficient mice would have sustained C5a activity, leading to disease exacerbation.. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP).. Contrary to our hypothesis, Cpb2(-/-) mice had significantly improved survival, with reduced lung edema, less liver and kidney damage, and less disseminated intravascular coagulation. Hepatic pro-CPB2 was induced by CLP, leading to increased pro-CPB2 levels. Thrombomodulin present on mesothelium supported thrombin activation of pro-CPB2. Both wild-type and Cpb2(-/-) animals treated with a C5a receptor antagonist had improved survival, demonstrating that C5a was detrimental in this model. Treatment with a fibrinolysis inhibitor, tranexamic acid, caused a decrease in survival in both genotypes; however, the Cpb2(-/-) animals retained their survival advantage. Administration of a C3a receptor antagonist exacerbated the disease in both wild-type and Cpb2(-/-) mice and eliminated the survival advantage of Cpb2(-/-) mice. C5a receptor is expressed in both peritoneal macrophages and neutrophils; in contrast, C3a receptor expression is restricted to peritoneal macrophages, and C3a induced signaling in macrophages but not neutrophils.. While C5a exacerbates the peritonitis, resulting in a deleterious generalized inflammatory state, C3a activation of peritoneal macrophages may limit the initial infection following CLP, thereby playing a diametrically opposing protective role in this polymicrobial sepsis model.

Topics: Animals; Antifibrinolytic Agents; Blood Coagulation Disorders; Carboxypeptidase B2; Cecum; Cells, Cultured; Complement C3a; Complement C5a; Disease Models, Animal; Enzyme Activation; Fibrin; Inflammation Mediators; Leukopenia; Ligation; Liver; Macrophage Activation; Macrophages, Peritoneal; Male; Mice, Inbred C57BL; Mice, Knockout; Peritonitis; Protective Factors; Punctures; Risk Factors; Sepsis; Thrombin; Thrombomodulin; Time Factors

Fibrin(ogen) is central to hemostasis and thrombosis and also contributes to multiple physiologic and pathologic processes beyond coagulation. However, the precise contribution of soluble fibrinogen vs insoluble fibrin matrices to vascular integrity, tissue repair, inflammation, and disease has been undefined and unapproachable. To establish the means to distinguish fibrinogen- and fibrin-dependent processes in vivo, Fib(AEK) mice were generated that carry normal levels of circulating fibrinogen but lack the capacity for fibrin polymer formation due to a germ-line mutation in the Aα chain thrombin cleavage site. Homozygous Fib(AEK) mice developed to term and exhibited postnatal survival superior to that of fibrinogen-deficient mice. Unlike fibrinogen-deficient mice, platelet-rich plasma from Fib(AEK) mice supported normal platelet aggregation in vitro, highlighting that fibrinogen(AEK) retains the functional capacity to support interactions with platelets. Thrombin failed to release fibrinopeptide-A from fibrinogen(AEK) and failed to induce polymer formation with Fib(AEK) plasma or purified fibrinogen(AEK) in 37°C mixtures regardless of incubation time. Fib(AEK) mice displayed both an absence of fibrin polymer formation following liver injury, as assessed by electron microscopy, and a failure to generate stable occlusive thrombi following FeCl3 injury of carotid arteries. Fib(AEK) mice exhibited a profound impediment in Staphylococcus aureus clearance following intraperitoneal infection similar to fibrinogen-deficient mice, yet Fib(AEK) mice displayed a significant infection dose-dependent survival advantage over fibrinogen-deficient mice following peritonitis challenge. Collectively, these findings establish for the first time that fibrin polymer is the molecular form critical for antimicrobial mechanisms while simultaneously highlighting biologically meaningful contributions and functions of the soluble molecule.

Topics: Animals; Blood Coagulation Tests; Cells, Cultured; Fibrin; Fibrinogen; Flow Cytometry; Gene Expression Profiling; Hemostatics; Host-Pathogen Interactions; Mice; Mice, Knockout; Mutagenesis, Site-Directed; Mutation; Peritonitis; Platelet Aggregation; Staphylococcal Infections; Staphylococcus aureus

In this issue of Blood, Prasad et al describe a mouse model with a mutation in the Aα chain of fibrinogen such that no fibrin polymer is formed in vivo, allowing for the first time the differentiation of the role of fibrinogen vs fibrin oligomer or polymer in antimicrobial host defense and in hemostasis/thrombosis.

Topics: Animals; Fibrin; Fibrinogen; Host-Pathogen Interactions; Mutation; Peritonitis; Staphylococcal Infections; Staphylococcus aureus

Resolution of inflammation reduces pathological tissue destruction and restores tissue homeostasis. Here, we used a proteomic protease substrate discovery approach, terminal amine isotopic labeling of substrates (TAILS), to analyze the role of the macrophage-specific matrix metalloproteinase-12 (MMP12) in inflammation. In murine peritonitis, MMP12 inactivates antithrombin and activates prothrombin, prolonging the activated partial thromboplastin time. Furthermore, MMP12 inactivates complement C3 to reduce complement activation and inactivates the chemoattractant anaphylatoxins C3a and C5a, whereas iC3b and C3b opsonin cleavage increases phagocytosis. Loss of these anti-inflammatory activities in collagen-induced arthritis in Mmp12(-/-) mice leads to unresolved synovitis and extensive articular inflammation. Deep articular cartilage loss is associated with massive neutrophil infiltration and abnormal DNA neutrophil extracellular traps (NETs). The NETs are rich in fibrin and extracellular actin, which TAILS identified as MMP12 substrates. Thus, macrophage MMP12 in arthritis has multiple protective roles in countering neutrophil infiltration, clearing NETs, and dampening inflammatory pathways to prepare for the resolution of inflammation.

Topics: Actins; Animals; Arthritis, Experimental; Cartilage; Cell Line; Complement Activation; Complement C3; Extracellular Traps; Fibrin; Macrophages; Male; Matrix Metalloproteinase 12; Mice; Mice, Inbred C57BL; Neutrophil Infiltration; Neutrophils; Peritonitis; Prothrombin

While testing the effect of the (β15-66)(2) fragment, which mimics a pair of fibrin βN-domains, on the morphology of endothelial cells, we found that this fragment induces redistribution of vascular endothelial-cadherin in a process that is inhibited by the receptor-associated protein (RAP). Based on this finding, we hypothesized that fibrin may interact with members of RAP-dependent low-density lipoprotein (LDL) receptor family. To test this hypothesis, we examined the interaction of (β15-66)(2), fibrin, and several fibrin-derived fragments with 2 members of this family by ELISA and surface plasmon resonance. The experiments showed that very LDL (VLDL) receptor (VLDLR) interacts with high affinity with fibrin through its βN-domains, and this interaction is inhibited by RAP and (β15-66)(2). Furthermore, RAP inhibited transendothelial migration of neutrophils induced by fibrin-derived NDSK-II fragment containing βN-domains, suggesting the involvement of VLDLR in fibrin-dependent leukocyte transmigration. Our experiments with VLDLR-deficient mice confirmed this suggestion by showing that, in contrast to wild-type mice, fibrin-dependent leukocyte transmigration does not occur in such mice. Altogether, the present study identified VLDLR as a novel endothelial cell receptor for fibrin that promotes fibrin-dependent leukocyte transmigration and thereby inflammation. Establishing the molecular mechanism underlying this interaction may result in the development of novel inhibitors of fibrin-dependent inflammation.

Topics: Animals; Antigens, CD; Cadherins; Cells, Cultured; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Fibrin; Fibrin Fibrinogen Degradation Products; Fluorescent Antibody Technique; Humans; LDL-Receptor Related Protein-Associated Protein; Leukocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Peritonitis; Receptors, LDL; Surface Plasmon Resonance; Transendothelial and Transepithelial Migration

Macrophage exiting from inflammatory sites is critical to limit the local innate immune response. With tissue insult, resident tissue macrophages rapidly efflux to lymph nodes where they modulate the adaptive immune response, and inflammatory macrophages attracted to the site of injury then exit during the resolution phase. However, the mechanisms that regulate macrophage efflux are poorly understood. This study has investigated soluble forms of integrin β2 whose levels are elevated in experimental peritonitis at times when macrophages are exiting the peritoneum, suggesting that its proteolytic shedding may be involved in macrophage efflux. Both constitutive and inducible metalloproteinase-dependent shedding of integrin β2 from mouse macrophages are demonstrated. Soluble integrin β2 is primarily released as a heterodimeric complex with αM that retains its ability to bind its ligands intracellular adhesion molecule-1, fibrin, and collagen and thus may serve as a soluble antagonist. In a model of accelerated exiting, administration of a metalloproteinase inhibitor prevents macrophage efflux by 50% and impedes loss of macrophage integrin β2 from the cell surface. Exiting of peritoneal macrophages in mice lacking integrin β2 is accelerated, and antibody disruption of integrin β2-substrate interactions can reverse 50% of the metalloprotease inhibitor blockade of macrophage exiting. Thus, our study demonstrates the ability of metalloproteinase-mediated shedding of integrin β2 to promote macrophage efflux from inflammatory sites, and the release of soluble integrin heterodimers may also limit local inflammation.

Topics: alpha-Macroglobulins; Animals; CD18 Antigens; Cell Movement; Cells, Cultured; Collagen; Fibrin; Humans; Inflammation; Intercellular Adhesion Molecule-1; Macrophages, Peritoneal; Metalloproteases; Mice; Mice, Mutant Strains; Peritonitis; Protein Multimerization

Peritonitis and the rare sequela of encapsulating peritoneal sclerosis (EPS) are serious problems in patients on peritoneal dialysis therapy. Chronic and persistent peritoneal injuries may be a risk factor of EPS. We previously reported that a chronic, proliferative peritonitis developed when zymosan was administered intraperitoneally following scraping injury of rat peritoneum (Mizuno M, Ito Y, Hepburn N, Mizuno T, Noda Y, Yuzawa Y, Harris CL, Morgan BP, Matsuo S. J Immunol 183: 1403-1412, 2009). Peritoneal membrane complement regulators (CRegs), especially Crry and CD59, protected from injury by inhibiting local complement activation, suggesting that CRegs play important roles in maintaining homeostasis in rat peritoneum. Here, we investigated roles of complement in the development of EPS by neutralizing CReg function with monoclonal antibodies (MAbs). Proliferative peritonitis was induced by scraping the peritoneum, followed by daily intraperitoneal administration of zymosan. When either Crry or CD59 alone was neutralized by MAb, the tissue injuries were not significantly changed compared with rats without neutralizing MAb. When both Crry and CD59 were neutralized in this model, severe fibrin exudation was observed on the peritoneal surface on day 5, accompanied by inflammatory cell infiltration, resembling the early stages of development of EPS. Dense peritoneal deposition of C3 fragments and membrane attack complex were observed, along with the fibrin exudates. Intravenous administration of cobra venom factor, which profoundly activates complement, further enhanced these pathological changes. Our results show that complement activation in injured peritoneum drives peritoneal inflammation, and that enhancement of complement activation by inhibiting CReg and/or enhancing systemic activation contributes to the initiation of EPS; therefore, anti-complement agents might be of therapeutic value in humans for the treatment of EPS.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Neutralizing; Antigens, Surface; CD59 Antigens; Complement Activation; Complement System Proteins; Disease Models, Animal; Fibrin; Homeostasis; Male; Peritoneal Dialysis; Peritoneum; Peritonitis; Rats; Rats, Sprague-Dawley; Receptors, Cell Surface; Severity of Illness Index; Zymosan

Improper compartmentalization of the inflammatory response leads to systemic inflammation in sepsis. Hemoadsorption (HA) is an emerging approach to modulate sepsis-induced inflammation. We sought to define the effects of HA on inflammatory compartmentalization in Escherichia coli-induced fibrin peritonitis in rats.. HA both reprograms and recompartmentalizes inflammation in sepsis. Sprague Dawley male rats were subjected to E. coli peritonitis and, after 24 h, were randomized to HA or sham treatment (sepsis alone). Venous blood samples collected at 0, 1, 3 and 6 h (that is, 24-30 h of total experimental sepsis), and peritoneal samples collected at 0 and 6 h, were assayed for 14 cytokines along with NO(2)(-/)NO(3)(-). Bacterial counts were assessed in the peritoneal fluid at 0 and 6 h. Plasma tumor necrosis factor (TNF)-α, interleukin (IL)-6, CXCL-1, and CCL2 were significantly reduced in HA versus sham. Principal component analysis (PCA) suggested that inflammation in sham was driven by IL-6 and TNF-α, whereas HA-associated inflammation was driven primarily by TNF-α, CXCL-1, IL-10 and CCL2. Whereas -peritoneal bacterial counts, plasma aspartate transaminase levels and peritoneal IL-5, IL-6, IL-18, interferon (IFN)-γ and NO(2)(-)/NO(3)(-) were significantly lower, both CXCL-1 and CCL2 as well as the peritoneal-to-plasma ratios of TNF-α, CXCL-1 and CCL2 were significantly higher in HA versus sham, suggesting that HA-induced inflammatory recompartmentalization leads to the different inflammatory drivers discerned in part by PCA. In conclusion, this study demonstrates the utility of combined in vivo/in silico methods and suggests that HA exerts differential effects on mediator gradients between local and systemic compartments that ultimately benefit the host.

Topics: Adsorption; Animals; Biomarkers; Colony Count, Microbial; Computational Biology; Escherichia coli; Fibrin; Hemofiltration; Inflammation; Inflammation Mediators; Liver; Male; Peritoneum; Peritonitis; Principal Component Analysis; Rats; Rats, Sprague-Dawley; Sepsis

Staphylococcus aureus is a frequent cause of skin infection and sepsis in humans. Preclinical vaccine studies with S. aureus have used a mouse model with intraperitoneal challenge and survival determination as a measure for efficacy. To appreciate the selection of protective antigens in this model, we sought to characterize the pathological attributes of S. aureus infection in the peritoneal cavity. Testing C57BL/6J and BALB/c mice, >10(9) CFU of S. aureus Newman were needed to produce a lethal outcome in 90% of animals infected via intraperitoneal injection. Both necropsy and histopathology revealed the presence of intraperitoneal abscesses in the vicinity of inoculation sites. Abscesses were comprised of fibrin as well as collagen deposits and immune cells with staphylococci replicating at the center of these lesions. Animals that succumbed to challenge harbored staphylococci in abscess lesions and in blood. The establishment of lethal infections, but not the development of intraperitoneal abscesses, was dependent on S. aureus expression of alpha-hemolysin (Hla). Active immunization with nontoxigenic Hla(H35L) or passive immunization with neutralizing monoclonal antibodies protected mice against early lethal events associated with intraperitoneal S. aureus infection but did not affect the establishment of abscess lesions. These results characterize a mouse model for the study of intraperitoneal abscess formation by S. aureus, a disease that occurs frequently in humans undergoing continuous ambulatory peritoneal dialysis for end-stage renal disease.

Topics: Abscess; Animals; Antibodies, Neutralizing; Bacterial Toxins; Collagen; Disease Models, Animal; Female; Fibrin; Hemolysin Proteins; Kidney Diseases; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Peritonitis; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Anti-Infective Agents; Cytokines; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Fibrin; Fibrinolysis; Humans; Mice; Mice, Inbred C57BL; Peritonitis; Protein C; Rats; Time Factors

The interaction of the fibrin βN-domain with VE-cadherin on endothelial cells is implicated in transendothelial migration of leukocytes, and the β15-42 fragment representing part of this domain has been shown to inhibit this process. However, our previous study revealed that only a dimeric (β15-66)(2) fragment, corresponding to the full-length βN-domain and mimicking its dimeric arrangement in fibrin, bound to VE-cadherin.. To test our hypothesis that dimerization of β15-42-containing fragments increases their affinity for VE-cadherin and ability to inhibit transendothelial migration of leukocytes.. Interaction of β15-42-containing fragments with VE-cadherin was characterized by ELISA and surface plasmon resonance. The inhibitory effect of such fragments was tested in vitro with a leukocyte transendothelial migration assay and in vivo with mouse models of peritonitis and myocardial ischemia-reperfusion injury.. First, we prepared the monomeric β15-42 and β15-64 fragments and their dimeric forms, (β15-44)(2) and (β15-66)(2) , and studied their interaction with the fibrin-binding domain of VE-cadherin, VE-cad(3). The experiments revealed that both dimeric fragments bound to VE-cad(3) with high affinity, whereas the affinities of β15-42 and β15-64 were significantly lower. Next, we tested the ability of these fragments to inhibit leukocyte transmigration in vitro and infiltration into the inflamed peritoneum in vivo, and found that the inhibitory effects of the dimers on these processes were also superior. Furthermore, (β15-44)(2) significantly reduced myocardial injury induced by ischemia-reperfusion.. The results confirm our hypotheses and indicate that (β15-66)(2) and (β15-44)(2) , which exhibited much higher affinity for VE-cadherin, are highly effective in suppressing inflammation by inhibiting leukocyte transmigration.

Topics: Animals; Antigens, CD; Cadherins; Cardiotonic Agents; Cell Movement; Dimerization; Endothelial Cells; Fibrin; Fibrin Fibrinogen Degradation Products; Human Umbilical Vein Endothelial Cells; Humans; In Vitro Techniques; Inflammation; Leukocytes; Mice; Mice, Inbred C57BL; Myocardial Reperfusion Injury; Peptide Fragments; Peritonitis; Protein Interaction Domains and Motifs

The goal of research is learning the change dynamic of "mature" fibrin in ridneys parenchyma in treatment of experimental bilious peritonitis with sodium hypochlorite. The work was made on 31 mongrel dogs, which were divided into two groups: control and experimental. It was revealed on with 24-hours experimental bilious peritonitis the presence of hyaline cylinders in the lumen of glomerular capillaries, which give a positive reaction to the "mature" fibrin. On the 3rd day of treatment with sodium hypochlorite in kidneys was revealed "mature" fibrin mostly extravascular localization with the significant decrease both the average size of "mature" fibrin and its volume fraction, which completely disappeared. what was the evidence of the arresting of hemocoagulation disorders under the influence of sodium hypochlorite.

Topics: Animals; Blood Coagulation Disorders; Disease Models, Animal; Dogs; Fibrin; Kidney Glomerulus; Male; Oxidants; Peritonitis; Sodium Hypochlorite

Different macromolecules were administered intraperitoneally to stimulate formation of protein-rich ascitic fluid in rodents. Stimulatory effect of plant lectins depended on the attachment to cell surface carbohydrates, Canavalia ensiformis (ConA) lectin was used in the majority of experiments. The time course of ConA-induced ascites was divided into an early (up to 4 h) and a late (from 6 h on) phase, with a transitional period between the two. Water and protein accumulation showed parallel time courses: volume of the ascitic fluid peaked at around 3 h, and fibrin threads appeared after 6 h. Viscosity of the ascitic fluid and its supernatant increased with time, reaching maximal fibrinogen concentration at around 16 h. Peritoneal permeability, followed by pleural and pericardial effusions, was elicited only by lectins that form soluble complexes with serum glycoproteins, whereas the effect of serum-precipitating lectins was restricted to the peritoneum. Macromolecules with serial positive charges (e.g., polylysine or polyethyleneimine) enhanced peritoneal permeability by ionic interactions with cell surface molecules. Viscosity of the polycation-induced ascitic fluid did not tend to increase with time and corresponded to the early phase of the ConA-induced ascites. Polyglutamate, a polyanionic macromolecule, inhibited the effect of polycations, but not that of ConA. The most efficient stimulatory macromolecules appear to induce ascites by noncovalent cross-linking of cell surface glycoproteins or glycosaminoglycans or both. A similar mechanism may operate in the maintenance of basal secretion to prevent eventual desiccation. Noncovalent cross-linking appears to be a common denominator of both basal and enhanced permeability.

Topics: Animals; Ascites; Ascitic Fluid; Female; Fibrin; Injections, Intraperitoneal; Mice; Pericardial Effusion; Peritonitis; Permeability; Plant Lectins; Pleural Effusion; Polymers; Rats; Rats, Wistar; Serum Albumin; Time Factors; Viscosity

Peritonitis represents a procoagulant state because of activated coagulation and inhibited fibrinolysis. Intra-abdominal fibrin deposition-entrapping bacteria-prevents bacterial spread but impairs bacterial clearance. Activating intra-abdominal fibrinolysis by recombinant tissue-type plasminogen activator (r-tPA) early during peritonitis may enhance bacterial clearance and reduce inflammation. This study examines effects of abdominal r-tPA lavage on local and distant coagulation, fibrinolysis, and inflammatory responses in experimental polymicrobial peritonitis. Twenty-four hours after cecal ligation and puncture, mice were exposed to therapeutic abdominal lavage with varying doses of r-tPA or saline (controls). Coagulation, fibrinolysis, and inflammation were assessed in abdominal, systemic, and pulmonary compartments (n = 6 per group per time point). Survival was assessed during 96 h (n = 16 per group). Highest-dose (2 mg/mL) r-tPA lavage caused immediate death. High-dose (0.5 mg/mL) r-tPA lavage increased fibrinolysis, demonstrated by low abdominal plasminogen activator inhibitor 1 levels and elevated pulmonary tPA levels, resulting in reduced abdominal bacterial load, chemokine levels, leukocyte influx, and thrombin generation, along with less pulmonary fibrin depositions and organ damage on histological examination (P < 0.05 vs. saline lavage). Low-dose (0.05 mg/mL) r-tPA lavage showed hardly any effect compared with saline lavage. Adversely, abdominal and plasma interleukin (IL) 12 were elevated, whereas IL-10 levels were decreased after high-dose r-tPA lavage (P < 0.05 vs. saline). Survival rate was not affected by any dose of r-tPA lavage compared with saline lavage. Delayed local stimulation of fibrinolysis by peritoneal r-tPA lavage enhanced intra-abdominal bacterial clearance and reduced intra- and extra-abdominal coagulation responses in a dose-dependent manner. Survival rate was unaffected likely due to adverse changes in IL-12 and IL-10 levels.

Topics: Animals; Blood Coagulation; Cecum; Chemokines; Dose-Response Relationship, Drug; Fibrin; Fibrinolysis; Immunohistochemistry; Inflammation; Interleukin-10; Interleukin-12; Male; Mice; Mice, Inbred C57BL; Peritoneal Lavage; Peritonitis; Plasminogen Activator Inhibitor 1; Recombinant Proteins; Sodium Chloride; Survival Rate; Thrombin; Tissue Plasminogen Activator

The factor V Leiden (FVL) mutation (Arg506Glu) results in the production of an FV protein that when activated is relatively resistant to inactivation by activated protein C and thereby leads to predisposition to thrombosis. The rather high prevalence of the FVL mutation in the general population prompted speculation about a potential survival benefit for individuals carrying the FVL allele. Indeed, both clinical and experimental animal data suggest that a heterozygous FVL genotype might protect against the lethal consequences of sepsis. We sought to confirm the survival advantage of heterozygous FVL mice in septic disease.. Controlled animal experiment.. Academic research laboratory.. Wild-type, heterozygous, and homozygous FVL mice subjected to 1 x 10 live bacteria as model for septic peritonitis.. None.. The intraperitoneal injection of E. coli led to growth and dissemination of bacteria and provoked an inflammatory response as evident from elevated cytokine levels (interleukin-6, interleukin-10, and tumor necrosis factor-alpha), induced thrombin-antithrombin complex levels, increased granulocyte influx into the peritoneal cavity, liver necrosis, and adhesion of leukocytes to the vessel wall, resulting in approximately 50% mortality after 72 hrs. The FVL genotype had no significant effect on bacterial outgrowth, markers of inflammation (i.e., tumor necrosis factor-alpha levels of 152 [96.2-200], 152 [99.7-1745], and 110 [99.7-177] pg/mL in peritoneal lavage fluid at t = 20 hrs for wild-type, heterozygous, and homozygous FVL mice, respectively), thrombin generation (i.e., thrombin-antithrombin complex levels of 19.9 [9.31-37.4], 10.4 [6.55-15.8], and 12.6 [8.24-29.0] ng/mL in peritoneal lavage fluid at t = 6 hrs for wild-type, heterozygous, and homozygous FVL mice, respectively), and/or survival (50%, 36%, and 50% for wild-type, heterozygous, and homozygous FVL mice, respectively).. The FVL allele has no beneficial effect in mouse septic peritonitis, and the general protective effect of FVL in sepsis needs further investigation.

Topics: Animals; Antithrombin III; Ascitic Fluid; Cell Adhesion; Cytokines; Disease Models, Animal; Escherichia coli; Factor V; Fibrin; Genotype; Granulocytes; Heterozygote; Homozygote; Kidney; Leukocytes; Liver; Lung; Mice; Mice, Transgenic; Necrosis; Peptide Hydrolases; Peritoneal Lavage; Peritonitis; Point Mutation; Sepsis; Thrombosis

Bowel perforation can lead to significant bacterial spillage, which may then cause septic peritonitis, characterized by a systemic inflammatory response and organ dysfunction. There are several reports that have shown that the development of peritoneal adhesions is dependent on inflammatory cytokine levels and that these adhesions can reduce bacterial spread, possibly by sealing off the cecum in the cecal ligation and puncture (CLP) model of septic peritonitis. There have not, however, been any studies that have utilized a strategy to accelerate tissue repair in order to seal off the injured cecum and reduce bacterial spread as well as ameliorate systemic inflammation. In the present study, we demonstrate that the administration of anti-gamma interferon (IFN-gamma) antibody (1.2 mg/kg of body weight, intravenously) accelerated tissue repair via increased fibrin deposition 12 and 24 h after CLP in rats. This increase in fibrin deposition was associated with peritoneal adhesion 24 h after CLP and a reduction in bacterial load compared to the bacterial load of rats given irrelevant antibody. Plasma fibrin levels, however, were not altered after IFN-gamma antibody administration, suggesting that the inhibition of IFN-gamma activity specifically increased fibrin deposition to the site of injury. Furthermore, plasma interleukin-6, used as a marker of systemic inflammatory response, was reduced in CLP rats given IFN-gamma antibody compared to that found in those given irrelevant antibody. These results suggest that the early inhibition of IFN-gamma activity in the CLP model is beneficial by accelerating fibrin deposition in cecal tissue to prevent bacterial spread and reduce the systemic inflammatory response. Importantly, increased fibrin deposition in the ceca was not associated with increased plasma fibrin whereas the latter may have detrimental effects associated with coagulation disorders.

Topics: Animals; Bacteria; Blotting, Western; Fibrin; Fibrinogen; Interferon-gamma; Interleukin-6; Male; Peritonitis; Plasminogen Activator Inhibitor 1; Rats; Rats, Sprague-Dawley

Measurement of the fibrinolytic response of the peritoneum to experimental peritonitis and ischaemia.. Controlled study. Academic surgical unit, UK MATERIAL: Male Wistar rats. Peritoneal injuries were caused in four groups of male Wistar rats (n = 35 in each group): (1) control group ("open and close" laparotomy); (2) bacterial peritonitis (mixed faecal flora); (3) chemical peritonitis (10 mg/ml tetracycline) and; (4) ischaemic peritoneum (ligated peritoneal buttons). Peritoneal biopsy specimens were taken from five animals in each group at seven time intervals and plasminogen activating activity (PAA) measured by fibrin plate assay.. Compared with the control group the three peritoneal injuries produced a uniform reduction in PAA during the first 6 and 12 hours: at 6 hours the median PAA was 0.029 IU/cm2 for bacterial peritonitis, 0.021 IU/cm2 for chemical peritonitis, and 0.05 IU/cm2 for ischaemic peritoneum compared with 0.112 IU/cm2 for the control group; p < 0.001, ANOVA. At 12 hours the median PAA was 0.024 IU/cm2 for bacterial peritonitis, < or = 0.014 IU/cm2 for chemical peritonitis, and 0.05 IU/cm2 for ischaemic peritoneum compared with 0.112 IU/cm2 for the control group; p < 0.001, ANOVA. There then followed a rebound peak in all groups, maximal at 4-7 days, before a return to baseline values at two weeks.. Peritoneal fibrinolysis was appreciably inhibited after three different standardised peritoneal injuries. The data support the hypothesis that there is a single pathophysiological mechanism of adhesion formation.

Topics: Animals; Bacterial Infections; Fibrin; Fibrinolysis; Ischemia; Male; Models, Biological; Peritoneum; Peritonitis; Plasminogen; Postoperative Period; Rats; Rats, Wistar; Tetracycline; Time Factors

Topics: Cellulitis; Fibrin; Hernia, Inguinal; Humans; Male; Middle Aged; Peritonitis; Postoperative Complications; Rupture, Spontaneous

Intracatheter streptokinase (SK) is advocated as effective treatment with minimal adverse effects in both recurrent bacterial peritonitis and catheter fibrin blockage in continuous ambulatory peritoneal dialysis (CAPD) patients. We reviewed 35 instillations in 20 patients noting a high (86%) side effect profile consisting of fever, onset of turbid dialysis effluent and/or abdominal pain. SK probably releases fibrin clot containing bacteria, leukocytes and debris from the colonized catheter into the peritoneal cavity causing a "peritonitis-like syndrome" of 1 to 3 days duration. Fungal peritonitis occurred after SK in 2 patients. Failure of SK therapy was encountered in Staphylococcus epidermidis infection (p less than 0.05 versus other organisms), which may be related to its protective capsular polysaccharide slime and ability to adhere to plastic prosthetic devices. SK, in this study, was useful treatment in relapsing bacterial peritonitis (50% overall cure) but failed to correct catheter malfunction.

Topics: Adult; Aged; Bacterial Infections; Catheterization; Catheters, Indwelling; Drug Evaluation; Equipment Failure; Female; Fibrin; Humans; Male; Middle Aged; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Recurrence; Retrospective Studies; Streptokinase

Catheter obstruction due to fibrin deposits during CAPD can cause poor outflow of peritoneal fluid and recurrent peritonitis. In order to treat this complication, 75,000 IU of diluted Urokinase (UK) were infused into catheters obstructed by fibrin in 10 CAPD patients (4 of which had peritonitis), without adverse reactions. After 60 minutes, a 2 liter exchange of peritoneal fluid was performed. In all the cases a normal outflow was restored. Hemostasis parameters (PT, PTT, TT, Fibrinogen, FDP, Fibrin monomers, BT, AT III) and blood cells count (RBC, HGB, HCT, WBC, PTL), were assayed before and two hours after the UK infusion, and did not show any significant variation, except for a decrease of white blood cells, which remained, however, within the normal range. No peritonitis episode occurred in the follow-up period. UK fibrinolytic therapy is safe and effective in treating fibrin obstruction of CAPD catheters without catheter removal and prevents recurrent peritonitis.

Topics: Catheters, Indwelling; Female; Fibrin; Hemostasis; Humans; Infusions, Parenteral; Kidney Failure, Chronic; Male; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Recurrence; Urokinase-Type Plasminogen Activator

The synergic relationship between Escherichia coli and Bacteroides fragilis was examined in a model of intra-abdominal abscess formation. The addition of B. fragilis to E. coli in the fibrin clot inoculum increased abscess weight and residual numbers of E. coli in the abscess at 7 days. In a reciprocal fashion, E. coli was capable of enhancing B. fragilis persistence in abscesses. Neither heat-killed E. coli nor heat-killed B. fragilis was able to mimic the synergic effect of its live counterpart. Furthermore, B. fragilis culture filtrate was unable to reproduce the ability of live B. fragilis to act synergically with E. coli. For B. fragilis to act synergically with E. coli, it had to be inoculated locally with E. coli in the peritoneal cavity, indicating that an effect on systemic resistance by B. fragilis was an unlikely mechanism for the production of bacterial synergy. These studies suggest that the synergic relationship between bacteria in polymicrobial infections is a complex one, resulting from intimate interactions between bacteria and the host in the local milieu of the infection.

Topics: Abscess; Animals; Bacteroides fragilis; Bacteroides Infections; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Fibrin; Male; Peritonitis; Rats; Rats, Inbred Strains

Topics: Abscess; Combined Modality Therapy; Debridement; Fibrin; Humans; Middle Aged; Peritoneal Lavage; Peritonitis; Postoperative Complications

Sclerosing peritonitis is a severe complication after CAPD treatment. The visceral peritoneum is thickened and interenteric adhesive parts are found. Myofibroblasts are proliferated and the collageneous tissue is hyperplastic. The mean clinical symptom is the mechanical obstruction of the small bowel. We observed this illness in three out of sixty patients under CAPD. These patients had higher incidence of bacterial peritonitis. In the ascites high concentrations of PG E2 and Thromboxan B2 were observed. After treatment of the infection the concentrations fell down to normal values. Electronoptical observations from peritoneal biopsies showed a proliferation of myofibroblasts and extracellular lysosomes. It is known from these lysosomes that they are able to set free proteasis. These lead to degredation of fibrin and fibrinogen. These splits are mitogen to myofibroblasts. release from HIT cells could also be evoked by the sulphonylureas glibenclamide and tolbutamide and by an increase in concentration of extracellular K+ to 40 mmol/l. The content of cyclic AMP in HIT cells was increased modestly by glucose but not by an increase in extracellular K+. Forskolin elicited a 4-fold increase in cyclic AMP content. We conclude that HIT cells retain the essential features of the insulin secretory response of normal B cells and represent an important tool for further biochemical characterisation of the secretory system.

Topics: Adult; Bacterial Infections; Dinoprostone; Female; Fibrin; Humans; Intestinal Obstruction; Intestine, Small; Male; Peritoneal Dialysis, Continuous Ambulatory; Peritoneum; Peritonitis; Prostaglandins E; Sclerosis; Thromboxane B2

Fibrin deposition initiated by peritonitis is thought to be an important local defense mechanism because it sequesters and walls off bacterial spillage. However, fibrin has been shown to predispose to residual abscess formation in rat peritonitis model. To examine the potential mechanisms of this effect, fibrin was tested in vitro for its inhibitory effect on neutrophil function. At all concentrations tested (50-1000 mg/dl), fibrin significantly impaired the ability of neutrophils to kill Escherichia coli. This inhibition occurred in a dose dependent fashion with almost complete prevention of killing at the highest concentration tested. Further studies showed that pre-exposure to fibrin did not reduce the neutrophil's ability to degranulate, undergo a respiratory burst, or kill E. coli, indicating that fibrin did not cause irreversible damage to the normal microbicidal functions of the neutrophil. However, fibrin, at physiologic concentrations, significantly impaired phagocytosis of radiolabeled E. coli. The data support the concept that phagocytosis of bacteria is impaired by neutrophils enmeshed in fibrin. Thus, contaminated fibrin could act as a nidus for residual abscesses formation following peritonitis even if an adequate number of normal leukocytes were present.

Topics: Escherichia coli; Fibrin; In Vitro Techniques; Luminescent Measurements; Muramidase; Neutrophils; Peritonitis; Phagocytosis

Classification is necessary when comparing and judging the results of the treatment of patients with peritonitis. Staging of peritonitis was developed according to interoperative findings. The spreading and age of peritonitis has been considered when contemplating further operative management. In order to judge the general clinical picture, a grading of severity into three groups, using a point scheme, was developed. 22 patients with localised peritonitis in an advanced stage received a closed peritoneal lavage. 31 patients with generalised peritonitis received continual open dorsoventral peritoneal lavage.

Topics: Drainage; Fibrin; Humans; Peritoneum; Peritonitis; Reoperation; Surgical Wound Dehiscence; Therapeutic Irrigation

The effect of aprotinin on the clinical and pathologic course of experimentally induced peritonitis in the rat was studied. Peritonitis was induced in 40 rats by creating a closed ileal loop 4 cm long 5 cm from the ileocecal valve. The rats were divided into two groups of 20 rats each. Group 1 served as a control group, whereas each animal in Group 2 received a bolus dose of aprotinin (10 ml) intraperitoneally immediately after closing the laparotomy. In the aprotinin-treated group, survival was drastically increased (p less than 0.01) and formation of adhesions and abscesses was considerably reduced. The results of peritoneal cultures showed a decreased incidence of Escherichia coli and Clostridia in the aprotinin-treated group. We conclude that the administration of aprotinin significantly prolongs the survival time of animals with peritonitis and reduces the development of adhesions and abscesses in the peritoneal cavity. This beneficial effect can be attributed to decreased fibrinogen deposits within the peritoneal cavity and the stabilization of the organism after bacterial shock. Thus, bacteria were more susceptible to cellular and noncellular clearing mechanisms.

Topics: Abscess; Animals; Aprotinin; Clostridium Infections; Escherichia coli Infections; Female; Fibrin; Male; Peritonitis; Rats; Rats, Inbred Strains; Surgical Wound Infection; Tissue Adhesions

We measured the rate of lethality and abscess formation in rats that underwent intraperitoneal implantation of fibrin clots contaminated with either Escherichia coli or Bacteroides fragilis alone or in combination, to determine whether the two organisms together would produce a synergistic infection. Ten-day mortality produced by 10(9) colony-forming units (CFU) of E coli was 33.3%. Encapsulated B fragilis led to 3.3% mortality. Escherichia coli (5 X 10(8) CFU) plus B fragilis (5 X 10(8) CFU) led to a sharp increase both in the rate and final ten-day mortality (80.0%). Eighty percent of the rats that received E coli (10(9) CFU within fibrin clots) had abscesses determined on the basis of grossly purulent material. All animals that received B fragilis and survived ten days contained abscesses. Synergy between E coli and B fragilis was noted to occur only when 5 X 10(8) CFU of each organism was present within the fibrin clot. Lower numbers did not produce significant synergy compared with controls that received either E coli or B fragilis. Quantitation of the number of organisms present at 24 hours within contaminated fibrin clots demonstrated a similar amount of growth of both organisms, either when added alone or in combination as copathogens.

Topics: Abscess; Animals; Bacteroides fragilis; Bacteroides Infections; Blood; Blood Coagulation; Disease Models, Animal; Escherichia coli; Escherichia coli Infections; Fibrin; Humans; Peritoneal Cavity; Peritonitis; Rats

Sixty Sprague-Dawley rats were inoculated with 10(9) Escherichia coli either suspended in 2 milliliters of normal saline solution or incorporated in a 2 milliliter 0.4 per cent fibrin clot. One hour after inoculation, one-half of the rats in each group received gentamicin, 12.5 milligrams per kilogram, intramuscularly. Escherichia coli suspended in normal saline solution was uniformly lethal. Incorporation of the bacteria and fibrin resulted in a survival of 13 of 15 rats (p = less than 0.002), but in abscess formation in all survivors. Treatment with gentamicin nearly abolished the mortality of Escherichia coli suspended in normal saline solution (14 of 15 rats survived, p = less than 0.002) but did not prevent abscess formation when bacteria were incorporated into fibrin. The gentamicin level exceeded the minimal inhibitory concentration (0.98 microgram per milliliter) for the strain of Escherichia coli used in serum (15.84 micrograms per milliliter after one hour) and peritoneal fluid (14.75 micrograms per milliliter after one hour) but never reached inhibitory levels in the fibrin clot (0.75 microgram per milliliter after one hour). We conclude that entrapment of bacteria by fibrin abolishes systemic sepsis but also protects bacteria against the action of systemic antibiotics and favors abscess formation.

Topics: Abscess; Animals; Drug Resistance, Microbial; Escherichia coli; Fibrin; Gentamicins; Male; Peritonitis; Rats; Rats, Inbred Strains

The effect of heparin upon the clinical and pathologic course of experimentally induced peritonitis in the rat was studied. Peritonitis was induced in 40 rats by creating a closed ileal loop 4 centimeters long at a distance of 5 centimeters from the ileocecal valve. The rats were divided into two groups of 20 each. The first group served as the control group while each rat of the second group received 30 units of heparin subcutaneously per day postoperatively. Survival was drastically increased in the group receiving heparin (p = 0.001). Adhesion or abscess formation was considerably reduced in this group. The results of peritoneal cultures showed decreased incidence of Escherichia coli and clostridia in the heparin-treated group. Blood cultures also showed decreased incidence of both aerobes and anaerobes in the treated group. It is concluded from this that the administration of heparin significantly prolongs survival time of animals with peritonitis and reduces the development of adhesions and abscesses in the peritoneal cavity. This beneficial effect could be attributed to decreased fibrinogen deposits within the peritoneal cavity, thus rendering the bacteria more susceptible to cellular and noncellular clearing mechanisms.

Topics: Abscess; Animals; Bacterial Infections; Clostridium; Escherichia coli; Female; Fibrin; Heparin; Male; Peritoneal Cavity; Peritonitis; Rats; Rats, Inbred Strains; Tissue Adhesions

The effect of intraperitoneal injections of bacterial toxin and adjuvant on the diaphragmatic mesothelium and their interaction with peritoneal cells was investigated in mice. At 30 minutes to 8 hours after stimulation, large numbers of neutrophils were seen on the mesothelial surface. Many of these cells exhibited features characteristic of locomotion over the mesothelial surface, whereas others appeared to be in the process of entering and passing through stomata into lymphatic vessels. By 24 hours numerous neutrophils, macrophages, and a small number of lymphocytes formed cellular aggregates that were surrounded by fibrin filaments. At 48 hours, the peritoneal cells were more closely aggregated and formed several layers on the mesothelial surface. By 72 hours fibrin filaments appeared to be broken down in many areas, with a resultant electron-dense precipitate occupying large areas of the intercellular spaces and on the surfaces of cells. It is suggested that the fibrin provides a matrix for the adhesion and subsequent aggregation of peritoneal cells to the mesothelial surface. The separation of neighboring mesothelial cells which surrounded stomata caused a widening of mesothelial pores (stomata), thereby facilitating the egress of the increased fluid and cellular infiltrations caused by the stimulation. The presence of patent stomata underlying the cellular aggregate demonstrates the importance of the diaphragmatic stomata as a major passageway for the removal of fluids and cells in the unstimulated, as well as during the inflammatory, response.

Topics: Animals; Ascitic Fluid; Bacterial Toxins; Cell Adhesion; Cell Aggregation; Cell Movement; Diaphragm; Epithelium; Female; Fibrin; Freund's Adjuvant; Lymphatic System; Macrophages; Male; Mice; Neutrophils; Peritonitis; Pseudopodia; Staphylococcus aureus

We have previously shown that fibrin can act to contain microorganisms and prevent early septic death in experimental peritonitis. However, this trapping eventuates in abscess formation. Fibrinogen, the precursor molecule of fibrin, is known to possess binding structures for some pathogenic organisms. We compared the extent of incorporation of various aerobic and anaerobic bacteria as well as polystyrene latex microspheres into fibrin clots. Similar numbers of organisms and microspheres were incorporated into either noncontracted or contracted fibrin clots. Detailed comparisons of the binding of Escherichia coli or Staphylococcus aureus to human fibrinogen were then made. The addition of 111:B4 lipopolysaccharide did not inhibit incorporation of E. coli 0111:B4 into either type of fibrin clot. With initial inoculum sizes of 10(6) to 10(8) colony-forming units (CFU)/ml, S. aureus was better incorporated into contracted fibrin clots (P less than 0.01) than was E. coli, possible evidence for an easily saturable receptor mechanism. We concluded that microorganisms are incorporated into the polymerizing fibrin matrix in the same fashion as are inert particles of similar size, irrespective of external chemical structure. Adherence of bacteria to fibrinogen or polymerizing fibrin did not appear to represent a specific bacterial virulence factor, more likely representing an effective host defense mechanism of broad specificity.

Topics: Abscess; Animals; Bacteria; Blood Bactericidal Activity; Blood Coagulation; Escherichia coli; Fibrin; Fibrinogen; Lipopolysaccharides; Microspheres; Peritonitis; Polymers; Staphylococcus aureus

Fibrin has classically been considered a defense mechanism of the peritoneal cavity. We have studied the role of purified fibrin in the pathogenesis of intraperitoneal infection. Implantation of 0.5% bovine fibrin clots containing 2 X 10(8) E. coli into the rat peritoneal cavity reduces the 24-hour mortality rate from 100% to 0% compared to bacteria in a similar volume of saline solution. However, the 10-day mortality rate with fibrin is 90%; 100% develop intraperitoneal abscesses. Animals receiving sterile clots lyse than over 1 to 2 weeks without abscess formation. As few as 10(2) E. coli per fibrin clot produce abscesses, but 10(7) or more are required to produce death; without fibrin less than 10(7) E. coli neither kill nor produce intraperitoneal infections. Both late death and abscess size with 2 X 10(8) E. coli are directly proportional to the fibrin clot size but not the concentration of fibrin in the clot. Operative debridement of the fibrin at 4 or 24 hours completely eliminates abscess formation in surviving animals. In vitro growth of E. coli is neither stimulated nor inhibited by fibrin or fibrinogen. Fibrin delays systemic sepsis, but the entrapped bacteria cannot be easily eliminated by normal intraperitoneal bactericidal mechanisms and abscess formation occurs. Thus radical peritoneal debridement or anticoagulation may reduce the septic complications of peritonitis.

Topics: Abscess; Animals; Escherichia coli; Escherichia coli Infections; Fibrin; Fibrinogen; Fibrinolysis; Male; Peritoneal Cavity; Peritonitis; Rats; Time Factors

Two experiments were performed to determine the effect of heparin on experimental fibrinopurulent peritonitis in dogs. Peritonitis was induced by the creation of a 10 cm long isolated loop of terminal ileum. In a first experiment comprising 24 dogs the necrotic loop was removed 24 hours later without cleaning or irrigating the peritoneal cavity. All dogs showed fibrino-purulent peritonitis at that time. No antibiotics were given. All dogs received 500 ml of Ringer's lactate during surgery and were allowed p.o. fluids on the first postoperative day. At the time of excision the dogs were blindly randomized into a control group and two treatment groups receiving heparin 100 u/kg i.p. or s.c. respectively. Of the eight animals in the control group, five died of peritonitis and two showed residual intraperitoneal sepsis at the time of sacrifice 14 days after the initial surgery. Thus, only one dog cleared his peritoneal infection spontaneously. Of the heparin treated dogs six out of eight in the i.p. treated and seven out of eight in the s.c. treated group cleared their peritonitis spontaneously within 14 days (p

Topics: Animals; Bacteria; Disease Models, Animal; Dogs; Female; Fibrin; Heparin; Ileum; Male; Peritonitis

Discrimination between the physiological cleavage fragments of fibrinogen and fibrin offers an approach to differentiation between fibrinogenolytic processes and fibrinolysis after coagulation. By use of the cleavage-associated neoantigen of fibrinogen (fg-D(neo)) as a molecular marker, characteristic differences between the D regions of fibrinogen derivatives and fibrin derivatives can be demonstrated. The expression of fg-D(neo) by X, Y, D:E complex, and D-fragments of fibrinogen or fibrin is shown to be quantitative and unitary. Characteristic differences between fg-D(neo) sites present on fibrinogen cleavage fragments, as contrasted to fibrin cleavage fragments, are indicated by different competitive inhibition slopes, and appear to reflect differential binding affinity of selected anti-fg-D(neo) antibodies for the specific molecular site. There is a linear relationship between the slope of quantitative competitive inhibition and the relative molar ratio of fibrinogen and fibrin derivatives. Identical immunochemical expressions are observed in vitro and in vivo, and support the thesis that cleavage in vivo is produced by plasmin. The differential immunochemical features of fg-D(neo) expression may be the result of stable conformational and/or subtle structural differences between the D region of fibrinogen and fibrin cleavage fragments and suggest that precise changes in the D region are associated with the fibrin transition. These molecular features not only provide additional insight into the molecular immunology and structure of fibrinogen, but also appear to offer a new molecular approach to discrimination between fibrinogenolytic mechanisms as contrasted to fibrinolysis secondary to coagulation.

Topics: Abruptio Placentae; Acute Kidney Injury; Adenocarcinoma; Binding Sites, Antibody; Binding, Competitive; Blood Coagulation Disorders; Epitopes; Female; Fibrin; Fibrinogen; Fibrinolysin; Fibrinolysis; Humans; Immune Sera; Iodine Isotopes; Male; Melanoma; Meningococcal Infections; Peritonitis; Pregnancy; Prostatic Neoplasms; Radioimmunoassay; Structure-Activity Relationship

Topics: Aged; Anuria; Cystitis; Diverticulum; Duodenal Ulcer; Female; Fibrin; Hernia, Inguinal; Humans; Ileum; Laparotomy; Male; Necrosis; Peritonitis; Rupture, Spontaneous; Tuberculosis, Urogenital; Urinary Bladder Calculi; Urinary Bladder Diseases; Urinary Bladder Neoplasms; Urination Disorders; Urography

Topics: Acute Disease; Appendicitis; Blood; Fibrin; Humans; Peritonitis; Thrombolytic Therapy