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At least 199 records · Page 11Linked to original sources
PubMed1999

Complement activation in coronary artery bypass grafting patients without cardiopulmonary bypass: the role of tissue injury by surgical incision.

STUDY OBJECTIVES: Complement activation is a trigger in inducing inflammation in patients who undergo coronary artery bypass grafting (CABG) and is usually thought to be induced by the use of cardiopulmonary bypass (CPB). In this study, we examined whether tissue injury caused by chest surgical incision per se contributes to complement activation in CABG patients. DESIGN: Prospective study. SETTING: Thorax center in university hospital. PATIENTS: Twenty-two patients undergoing CABG without CPB were prospectively divided into two groups: a small chest incision via an anterolateral thoracotomy representing a minimized tissue injury (lateral group, n = 8), and a conventional median sternotomy representing a large tissue injury (median group, n = 14). Biochemical markers indicating complement activation as well as systemic inflammatory response were determined before, during, and after the operation. MEASUREMENTS AND RESULTS: Plasma concentrations of complement 3a increased in both the lateral and median groups right after chest incision (p < 0.01 and p < 0.05, respectively) and by the end of operation increased only in the median group (p < 0.01). The terminal complement complex 5b-9 did not increase in the lateral group, but it did increase in the median group both after incision and by the end of the operation (p < 0.05 and p < 0.05, respectively). During surgery, complement 4a did not increase, suggesting that it is the alternative rather than the classic pathway that is involved in complement activation by tissue injury. Postoperatively, interleukin-6 production was greater in the median group (p < 0.01) than the lateral group (p < 0.05), suggesting a more pronounced inflammatory response to a larger chest incision. CONCLUSIONS: Tissue injury caused by surgical incision contributes to complement activation in CABG patients who are operated on without CPB. A small anterolateral thoracotomy is associated with reduced complement activation in comparison with a median sternotomy.

Adult↗
PubMed2002

Complement in central nervous system inflammation.

The complement system is well represented in the central nervous system. Glial cells and neurons produce or express all of the activation and regulatory proteins and the C3a/C5a receptors. Inhibition of complement activation is protective in experimental allergic encephalomyelitis, the animal model for multiple sclerosis, suggesting possible therapeutic approaches for human disease. New findings indicate that the C3a/C5a receptors are widely expressed in neurons and may modulate neuronal function.

Animals↗
PubMed1987

Relationships of serum opsonins and complement in human experimental gingivitis.

This study assessed the phagocytosis of polymorphonuclear neutrophils and the opsonic capacity of serum in experimental human gingivitis. Relationships were sought among these two measurements, clinical indices of gingivitis and complement-related opsonins. Measurements of chemiluminescence provided an index of phagocytosis and of opsonic capacity. Test group Plaque Index scores were higher than the control group on Days 7, 14, and 21, while the Gingival Index of the test group was elevated only on Day 21. Phagocytosis of test subjects' PMNs and opsonic capacity of their sera were no different from that of the controls'. Levels of C3 in both nonactivated and activated sera of the test group were significantly lower than that of the control group only on Day 14. In the test group, differences of per cent C3 conversion occurred between Days 14 and 21, and Plaque Index scores were inversely correlated with the order of per cent C3 data on these same days. Our results also indicate that complement contributes significantly to the serum opsonic capacity. The levels of developing plaque and subsequent gingival inflammation are apparently related to the degree of complement activation.

Adult↗
PubMed1993

Reinfusion of shed blood after orthopaedic procedures in children and adolescents.

A prospective study was done of the results of infusion of drained blood after major procedures on the spine and hip in twenty-six patients. The Solcotrans system was used to salvage drained blood in the first six hours after the operation. Transfusion requirements, blood loss, hematocrit, temperature, prothrombin time, partial prothrombin time, platelet count, results of blood cultures, and levels of factor VIII, factor V,D-dimer, antithrombin III, plasminogen, protein C, and complement C3a des arginine were determined for some or all of the patients. A mean of 375 milliliters of blood from the Solcotrans receptacle was reinfused. All of the cultures were negative. There were no febrile reactions. The mean values for the specimens of the salvaged blood were: hematocrit, 0.20; hemoglobin, seventy-one grams per liter; plasma hemoglobin, 2.36 grams per liter; C3a des arginine, 9.4 x 10(-3) grams per liter; fat particles of less than nine micrometers in diameter, 23,643 per milliliter; and D-dimer, 205 x 10(-3) grams per liter. Studies of blood samples that were collected from patients one to two hours and twelve to eighteen hours after the transfusion showed only slight increases in fibrin split products one hour after the transfusion; these values reverted to normal by eighteen hours. No clinical coagulopathy associated with reinfusion was observed. The reinfusion of unwashed, filtered shed blood that was as much as 15 per cent of the total blood volume proved to be a safe technique after major orthopaedic procedures.

Adolescent↗
PubMed2001

Circulating immune complexes induced by food proteins implicated in precocious myocardial infarction.

BACKGROUND: Circulating immune complexes (CIC) are frequently found in postinfarction patients. The constituents of these CIC are mostly unknown. AIM: The objective of the current study was to assess whether CIC containing alimentary proteins and antibodies against these proteins are implicated in precocious myocardial infarction (MI). METHODS: Seventy-six survivors (67 men and 9 women, mean age 39 years) of a first MI before the age of 45 years were enrolled in this study. Two control groups were included. One group consisted of age-matched, randomly selected, population-based healthy individuals, 79 men and 11 women, without features of coronary heart disease. An additional control group was used only for the determination of serum antibodies against some of the alimentary proteins and consisted of 139 healthy blood donors, 95 men and 44 women, with a mean age of 42 years. Sucrose density gradient centrifugation, gel filtration and precipitation by polyethylene glycol were used for the isolation of CIC, and enzyme-linked immunosorbent assay (ELISA) was used to measure the immunoglobulin levels and specific antibodies against alimentary proteins in both sera and isolated CIC. Sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis and Western blotting were used to determine alimentary proteins in the CIC. RESULTS: Alimentary antigens/antibodies were present in immune complex form in seven out of 14 (50%) postinfarction patients who had persistent high concentrations of CIC, the latter constituting 18% of the entire group. Antibodies of the IgG isotype predominated. A rise in CIC, signs of activation of the classical complement pathway, and a rise in plasma concentrations of von Willebrand factor antigen (vWFAg) were evident within 1 week in four patients subjected to a 2-week elimination diet followed by a single challenge with cow's milk. CONCLUSION: This study suggests that dietary proteins occasionally give rise to persistent CIC, which may predispose to MI at a young age.

Adult↗
PubMed2000

Trillium biopassive surface: a new biocompatible treatment for extracorporeal circulation circuits.

139 patients undergoing cardiac surgery were included in a prospective, randomized trial. Patients were randomly allocated to receive cardiopulmonary bypass (CPB) with Trillium Biopassive Surface (TBS Group) coated oxygenators or conventional circuits (control group). 112 patients were studied with respect to postoperative biochemical profile; a subgroup of 27 patients was studied with respect to perioperative complement (C3a) activation. Patients in the TBS group demonstrated a significantly lower white blood cell count at the end of the operation (p=0.036) and a significantly higher platelet count the day after the operation (p=0.023) when compared to the control group. C3a was significantly higher (p=0.02) in the TBS group after 30 minutes of CPB, but the C3a increase after protamine administration was significantly less pronounced in the TBS group vs. the control group. Further studies involving platelet and leukocyte activation are required to better elucidate the action of this new coating in the setting of routine CPB.

Biocompatible Materials↗
PubMedDate not supplied

The quality of blood used for transfusion.

The current risk of disease transmission through homologous blood transfusion has lead to a revival in the use of autologous blood. The development of a coagulopathy increases the usage of blood and blood products and therefore the risk of disease transmission. Blood salvaged at operation is subjected to physical and humoral activating factors. The potential systems to be activated are located either in the plasma or non red cell cellular elements. Homologous blood and blood salvaged at operation before and after washing was examined for activation of the plasma and cellular systems by measuring the presence of fibrin degradation products (xDP's), activated complement (C3a) and plasminogen activator and inhibitor activity from the plasma systems; and elastase, serotonin, lysophospholipids, leukotriene B4, lysoplatelet factor and phospholipase A2 from the cellular systems. The plasma systems were activated in the salvaged blood which had elevated levels of xDP's and C3a compared to the patient's blood (p less than 0.05). The products of cellular activation were also elevated in operatively salvaged blood (p less than 0.01 for all the above products). The levels xDP's were normal but the levels of C3a increased in stored blood. The levels of the cellular systems, elastase, serotonin and lysoplatelet activating factor, increased with the duration of storage of bank blood. Unwashed and aged stored blood contains potentially harmful products. Consideration should be given to removal of non red cell elements in blood stored for surgery.

Blood Cells↗
PubMed1990

Effect of anticoagulant on biocompatibility in membrane plasmapheresis.

The effect of heparin or citrate anticoagulation on blood cellular, complement pathway and coagulation pathway was investigated in a membrane plasma exchange procedure. Two membrane plasma separators constructed of cellulose di-acetate (CA) and polyvinyl chloride (PVC) were evaluated with heparin or citrate alone for anticoagulation in a 26 year old male with myasthenia gravis. Maximum white blood cell counts decrease was 21% at 30 min for the CA with heparin while no decrease was observed for the other schemes. Platelet counts changes were comparable between heparin and citrate, while the PVC groups showed less changes than the CA groups. The CA groups, regardless of the type of anticoagulant used, indicated that complement activation occurred via the classical pathway within the module in addition to the activation via alternative pathway for the CA with heparin. In the PVC groups, complement activation was noted to occur only when heparin was used for anticoagulation. PT and PTT showed slight increases with citrate, while they were remarkably prolonged with heparin. Citrate showed less changes in cellular and humoral factors compared to heparin. CA with heparin was the most activating combination of membrane material and anticoagulant, while the PVC with citrate was the least activating combination.

Adult↗
PubMed1990

[Allergic reaction and vascular permeability].

The allergic reaction is characterized by an inflammatory phenomenon that comprises a cellular aspect and a vascular aspect. The vascular aspect is linked to the production of several mediators able to induce a vascular hyperpermeability. Among these mediators it is possible to find histamine, prostaglandins, leukotrienes, PAF, neuromediators, kinins, anaphylatoxins.

Animals↗
PubMed1985

Structure and function of human C5a anaphylatoxin. Selective modification of tyrosine 23 alters biological activity but not antigenicity.

Reaction of either human C5a or its des-Arg74 derivative (des-Arg74-C5a) with tetranitromethane under nondenaturing conditions results in selective nitration of only 1 of the 2 tyrosine residues found in these glycopolypeptides. This reactive tyrosyl residue was identified as that found in position 23 of the sequence. Nitrotyrosyl23-C5a and -des-Arg74-C5a were separated from their respective unmodified precursors by cation-exchange fast protein liquid chromatography. These purified derivatives served as reagents for the subsequent preparation of both aminotyrosyl23-C5a and -des-Arg74-C5a as well as photoreactive analogs of C5a. Radioimmunoassays performed with C5a derivatives serving as competing ligands and a murine antihuman C5a monoclonal antibody employed as first antibody demonstrated that selective modification of tyrosine23 did not produce a detectible alteration in the antigenic properties of C5a. By contrast, either nitro- or aminotyrosyl23-C5a was approximately 3-fold less active than native C5a in both bioassays and competitive ligand-receptor binding assays. Additionally, photoreactive derivatives prepared by coupling either N-succinimidyl-6-(4'-azido-2'-nitrophenylamino)-hexanoate or p-nitrophenyl-2-diazo-3,3,3-trifluoropropionate to aminotyrosyl23-C5a at pH 5.0 failed to interact with the neutrophil C5a receptor. These observations suggest that the tyrosyl23 residue of C5a may participate importantly in the binding interactions of this chemotactic factor and its granulocyte receptor.

Affinity Labels↗
PubMed1989

Human erythrocytes inhibit complement-mediated solubilization of immune complexes.

Incubation of precipitable immune complexes (IC) with fresh human serum or guinea pig serum resulted in solubilization of IC. When packed human E were added to human serum or guinea pig serum, binding of IC to the E occurred and IC solubilization was significantly inhibited. By contrast, SRBC did not bind IC nor inhibit IC solubilization. Because IC binding to human E is mediated by CR type 1 (CR1) we evaluated whether CR1 was responsible for the inhibition of IC solubilization. Human E were treated with trypsin or anti-CR1 mAb. Both treatments abrogated IC binding to human E but did not affect the ability of the human E to inhibit IC solubilization. Human E inhibited C activation by IC. Thus, incubation of IC in human serum caused significant activation of C3 and C5, but not C4. However, when IC were incubated in whole blood or with isolated human E and serum, C3 activation by IC was inhibited significantly. In addition, we demonstrated that the C3b generated during C activation by IC deposited on both IC and human E. Thus, human E may compete for nascent C3 generated during C activation by IC. In conclusion, human E inhibit both complement-mediated solubilization of IC and C activation by IC.

Antigen-Antibody Complex↗
PubMedDate not supplied

[The reactivity of pulmonary and hepatic macrophages in normal and prestimulated animals].

The rate of blood clearing of colloidal carbon increased two-fold as compared to the controls 5 days after prodigiosin injection. This was attended by intensified recruitment of macrophages into the alveoli and increase in the number of phagocytizing macrophages in the interstitium of the lungs by 1.5 times above normal. After administration of zymosan granules, the rate of colloid carbon clearance increased 1.5-fold in 5 days and 2.5-fold on the 9th day; the recruitment of macrophages into the alveoli and the number of phagocytizing macrophages in the interstitium of the lungs increased two-fold. At the same time, granuloma-type mononuclear infiltrates formed in the lungs and liver. Prodigiosin injection increases the rate of blood clearance 1.2-fold in animals stimulated by zymosan granules, while the volume of mononuclear infiltration, which acquires a diffuse character, increases 2.5-fold as compared to the value in zymosan stimulated animals. The effects of phagocyte reconciliation may be directly related to exacerbations of chronic inflammatory diseases of different localization.

Animals↗