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Results for “Complement Hemolytic Activity Assay”

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At least 307 records · Page 17Linked to original sources
PubMed1993

Increased soluble IL-2 receptor in serum of patients with systemic lupus erythematosus.

We estimated the concentration of soluble IL-2R (sIL-2R) in the serum of patients with systemic lupus erythematosus (SLE) and examined the relationship between the serum levels of sIL-2R and clinical features or laboratory data. We found that elevated levels of sIL-2R were present in the serum of SLE patients with discoid rash, and sIL-2R concentrations were correlated with the soluble CD4 and soluble CD8 concentrations but not with classical serological marker, anti-DNA antibody or complement titer.

Adolescent↗
PubMed1993

Complement split product C3d as an indicator of disease activity in systemic lupus erythematosus.

In order to investigate, if complement levels can be used as an indicator of clinical activity in systemic lupus erythematosus (SLE), levels of C3, C4, CH50, and C3d were measured in 79 patients, 41 with inactive, 31 with moderately active and 7 with severely active disease. Our study shows that C3d, and particularly the C3d/C3 ratio, provide sensitive markers for disease activity in SLE. Since C3d is a direct measurement of complement turnover, it reflects complement activation better than C3, C4 and CH50.

Adolescent↗
PubMed2002

Recurrent pneumococcal meningitis in homozygous C3 deficiency.

Congenital deficiencies of complement system proteins are rare. A 4-year-old girl was admitted for meningitis. She had had repeated attacks of pneumococcal meningitis and otitis media at the age of 3 years. Analysis of cerebrospinal fluid showed that this meningitis was due to pneumococcal infection. Complement 3 and CH50 values of the proband and her brother were low, while her parents were normal. The patient was given polyvalent pneumococcal and anti-haemophilus vaccines plus ceftriaxone. Recovery was complete after 15 days of antibiotic therapy. This is the first description of a case of recurrent meningitis with C3 and CH50 deficiency in a Turkish family.

Child, Preschool↗
PubMed2000

Construction of eukaryotic expressing vector pCH503 of CH50 and its chemotaxis and anti-tumor function by expression in vivo in mice.

An eukaryotic expressing vector that expresses CH50, a recombinant polypeptide of human fibronectin, in mice was constructed, and its chemotactic and anti-tumor function by in vivo gene transfection was investigated. The plasmid was constructed by recombination techniques. The cDNA fragment coding CH50 polypeptide from a prokaryotic expressing vector of CH50 was ligated with 5'-terminal noncoding region and coding region of signal peptide of mouse IFN-gamma cDNA at 5' side and 3'-terminal noncoden region of human FN cDNA at 3' side. The recombinant cDNA was inserted into plasmid pREP8. The resulted expressing plasmid was designated as pCH503. The macrophages transfected with pCH503 in vivo and cultured in vitro could produce CH50. The expressed product was identified by heparin-affinity chromatography and SDS-PAGE. By counting and Giemsa-staining of coeliac cells and histotomy and staining of muscle tissue, the chemotaxis on immune cells was observed after transfection of pCH503 either in peritoneal cavity or in muscle. The inhibition of gene transfection of pCH503 on melanoma was observed in mice. The number of melanoma nodes in mice was reduced by 50%-60% after coeliac transfection with pCH503. The pCH503, an eukaryotic expressing vector of CH50, can express in vivo in mice. The transfection of pCH503 in vivo has the chemotaxis on immune cells and can inhibit the formation of tumor nodes, suggesting that plasmid pCH503 is potentially useful in combined treatment of tumor.

Animals↗
PubMed2001

Construction and expression of eukaryotic expressing vector pCH510 of polypeptide CH50 and its chemotaxis and antitumor function by in vivo transfection.

To construct an eukaryotic expressing vector that expresses CH50, a recombinant Cell I-Hep II bifunctional-domain polypeptide of human fibronectin, and to investigate the chemotaxis to immune cells and the inhibitory effect on the growth of tumor by the expression of the plasmid in vivo, the plasmid was constructed by DNA recombination. Gene transfection was performed in vitro and in vivo. The expressed product was identified by Western blot. The chemotaxis after gene transfection in vivo was observed by histotomy and staining of muscle tissues. The inhibition of gene transfection on solid tumor was observed in mice. The results showed that plasmid pCH510 was constructed by the recombination of the 5'-terminal noncoding region and signal peptide coding region of human fibronectin cDNA and cDNA fragment coding CH50 polypeptide with a 3'-terminal noncoding region of human FN cDNA, and the insertion of the recombinated fragment into plasmid pcDNA3. 1. After transfection with plasmid pCH510, NIH3T3 cells could produce CH50 polypeptide. The transfection of plasmid pCH510 by the injection in muscle of mouse could produce the effects of chemotaxis on immune cells and the inhibition on the growth of solid tumor. It is concluded that plasmid pCH510 can express in cells and in vivo in mouse. The expression of the plasmid in vivo has a chemotactic effect on immune cells and can inhibit the growth of solid tumor.

3T3 Cells↗
PubMed1998

Augmentation of recombinant fibronectin polypeptide CH50 on the antitumor function of macrophages.

We prepared an anti-metastatic polypeptide, recombinant fibronectin polypeptide CH50, and finished the preliminary identification of its functions. In this paper, we studied the effect of this polypeptide on the function of macrophages. CH50 can significantly augment the production of nitric oxide(NO) by macrophages in a dose-dependent manner. The continuous presence of CH50 had a much stronger effect. In the presence of CH50, the cytotoxicity of macrophages to melanoma B16/F1 cells was significantly enhanced, and a stronger effect was obtained if CH50 was present continuously. CH50 polypeptide and IFN-gamma have a synergistic effect on the production of NO by macrophages and the cytotoxicity of macrophages on tumor cells. In the in vivo experiments, CH50 can inhibit the growth of tumor cells, and have a better effect in the presence of IFN-gamma. Our results suggest that recombinant fibronectin polypeptide CH50 has two functions: one is to inhibit the metastasis of tumor cells, and the other one is to augment the function of macrophages. And this polypeptide will be potentially useful in tumor therapy.

Animals↗
PubMed1999

Clinical role of blood heparin level monitoring during open heart surgery.

Protamine has been used for neutralizing heparin and its dosage is decided by the initial fixed dose of heparin. Adequate protamine neutralization is very important to reduce complications. To attenuate excess reactions, in particular, whole blood heparin concentration during and after cardiopulmonary bypass was measured using Hepcon, and the efficacy of optimal protamine dose in open heart surgery was evaluated. Twenty patients were randomly divided into two comparable groups, P and C. In the C group, heparin was neutralized with an initial fixed dose of protamine, 1.67 mg protamine per milligram total heparin (n = 8). In the P group, protamine dose was determined for residual heparin concentration (n = 12). In the P group, blood heparin concentrations at 60 minutes after the establishment of cardiopulmonary bypass, just after cardiopulmonary bypass and first protamine administration were 2.35 +/- 0.14, 2.31 +/- 0.17 and 0.13 +/- 0.08 U/ml, respectively. Concentrations reached zero with the second protamine administration. The requirement of transfusion (659 +/- 224 vs. 1559 +/- 323 ml, p = 0.0314), pulmonary vascular resistance index just after the protamine administration (190 +/- 22 vs. 286 +/- 18 dyne.s.cm-5.m2, p = 0.0137) and the IL-8 levels (just after protamine: 26.9 +/- 5.1 vs. 43.5 +/- 5.9 pg/ml, p = 0.0499, 12 hours after cardiopulmonary bypass: 37.1 +/- 12.1 vs. 86.8 +/- 20.0, p = 0.0435) in the P group were significantly lower than those in the C group. These data suggested that heparin level monitoring in whole blood may be useful to determine the optimal dose of protamine resulting in the decrease of a requirement of blood components in open heart surgery and attenuating in transient pulmonary hypertension and excess protamine-induced inflammatory reactions.

Anticoagulants↗
PubMed2004

Monitoring the level of complement components during autologous blood stem cell transplantation in patients with malignant lymphomas.

The aim of this study was to determine the complement functions, the serum levels of the complement components C3 and C4, and circulating immune complexes during autologous blood stem cell transplantation. Seventeen lymphoma patients receiving transplants between 1997 and 2001 were involved in this study. High-dose chemotherapy with or without total body irradiation was used for conditioning. The transplantation resulted in complete remission without complications in 14 patients. Early relapse developed in one case and two nonrelapsed patients suffered from serious toxic infection early posttransplant. Normal values of CH50, C3, C4, and immune complexes in sera of patients were detected on day -7, before the conditioning (day of transplantation was determined as day 0). After the conditioning, on day -2, the levels of the CH50, C3, and C4 decreased significantly ( p<0.05) in all patients compared with the starting values. The CH50, C3, and C4 levels exceeded the starting values in the noninfected patients from day +7. In two patients suffering from toxic infection, significantly elevated complement levels were documented early posttransplant. In the relapsed patient a significant decrease of the complement parameters was documented posttransplant accompanied by a significant elevation in the immune complex level. The results show alteration in the complement parameters during transplantation, but in the complication-free cases this remained within the normal ranges. However, an unusual elevation seemed to be the sign of infection, and the significant decrease seemed to indicate a relapse.

Adult↗
PubMed1991

Purification of human complement factor D from the peritoneal fluid of patients on chronic ambulatory peritoneal dialysis.

We describe a simple procedure for the purification of human factor D from the peritoneal fluid (PF) of patients with end stage renal failure (ESRF) on chronic ambulatory peritoneal dialysis (CAPD). The main advantages of this method are: (1) a relative enrichment of factor D in PF versus plasma (factor D/total protein enriched 3.8-fold); thus, added to the elevated concentration of factor D in ESRF, the enrichment compared to normal human serum is approximately 50 fold. (2) This biological source of factor D is almost unlimited, since around 10 liters of PF are removed per day from each patient. The purification is performed in three simple steps-Bio Rex 70, Heparin Sepharose CL 6B and Mono S FPLC- and milligrams of highly purified factor D are obtained. Peritoneal fluid might be a valuable source for the purification of other low MW proteins which accumulate in renal failure.

Antibodies, Monoclonal↗
PubMed1992

Complement activation by lipopolysaccharides purified from gram-negative bacteria isolated from infected root canals.

The purpose of the present study was to investigate the complement activation by lipopolysaccharides purified from Porphyromonas (Bacteroides) endodontalis, Veillonella parvula, and Fusobacterium nucleatum isolated from infected root canals. The rate of consumption of the C3T component of the complement increased remarkably when lipopolysaccharides of more than 10 micrograms were added.

Bacteroides↗
PubMedDate not supplied

Lytic antibody titre as a means of assessing cure after treatment of Chagas disease: a 10 years follow-up study.

A complement-mediated lysis test (CoML) using living trypomastigotes was compared with conventional serological methods and with haemoculture. Over a 10 years follow-up period evidence was obtained which supported the view that chagasic patients, treated with nitroheterocyclic drugs, in whom CoML had reverted to negative, might be considered cured despite conventional serology remaining positive.

Adult↗
PubMed1995

Production and characterization of monoclonal antibodies against stonustoxin from Synanceja horrida.

Stonustoxin (SNTX), a lethal factor purified from the venom of stonefish Synanceja horrida, is a protein (148,000 mol. wt) existing as a dimer comprising two subunits (alpha and beta) of mol. wts 71,000 and 79,000, respectively. Its LD50 (i.v.) is 17 ng/g in mice and it causes haemolysis of rat and rabbit erythrocytes in vitro. Eight monoclonal antibodies (Mabs) against SNTX have been developed using the Balb/C mouse. These Mabs have been purified by Protein G affinity membrane disc chromatography. They were all classified as IgG1 with half of them having kappa and the rest lambda light chains. They had affinity constants ranging from 3.75 x 10(-9) to 9.74 x 10(-9) M. Six were able to protect mice from a challenge of a lethal dose of SNTX. However, not all protective Mabs were able to neutralize the haemolytic effect in vitro. Only four Mabs (31A, 32B, 38A and 46A) could inhibit rat and rabbit erythrocyte haemolysis, while one Mab (43D) offered partial inhibition and another Mab (8A) did not inhibit haemolysis at all. The non-protective Mabs (43B and 44G) were also incapable of neutralizing haemolysis. Five epitopes were recognized by the eight Mabs. Four Mabs (31A, 32B, 38A and 46A) were found to have similar epitope specificity while the rest were directed at different epitopes on the SNTX molecule. Thus these results suggest that the domain on the SNTX molecule responsible for lethality is probably distinct from the domain important for in vitro haemolytic activity.

Animals↗
PubMed1990

Complement activation in pulmonary tuberculosis.

The alterations in serum/plasma levels of total haemolytic complement activity (CH50), complement components C3 and C3d, and circulating immune complexes (CICs) in patients with pulmonary tuberculosis were analysed in relation to the severity of disease and treatment status. The mean levels of CH50, C3, C3d and CICs were significantly higher in untreated than treated patients and in normal controls. In the untreated group, the level of each of these four parameters except C3d was significantly higher in patients with far advanced disease than in those with moderately advanced disease, whereas the difference between treated patients and normal controls was not statistically significant for any of the four parameters tested. There were statistically significant correlations between levels of CICs and both C3 and C3d in the untreated tuberculosis patients. However, the correlations for the same parameters were not significant when treated patients were considered. The CH50 levels in tuberculosis patients suggest a functional classical complement pathway, which is essential for immune complex solubilisation. High C3d level in untreated patients is indicative of increased complement activation, which in turn shows significant correlation with levels of CICs. It appears that the intact and elevated complement proteins and their proper activation by CICs prevents tuberculosis from becoming a typical immune complex disease.

Adult↗
PubMed1996

Relationships between chemical characteristics and anticomplementary activity of fucans.

We have shown previously that a low-molecular-weight fucan extracted from the brown seaweed Ascophylum nodosum strongly inhibited human complement activation in vitro and its mechanism of action was largely elucidated. We further investigated the influence of molecular weight and chemical composition of fucan on its anticomplementary activity. The capacity of 12 fragments of fucan (ranging from a molecular weight of 4100 to 214,000) to prevent complement-mediated haemolysis of sheep erythrocytes (classical pathway) and of rabbit erythrocytes (alternative pathway) increased with increasing molecular weight, and reached a plateau for 40,000 and 13,500, respectively. The most potent fucan fractions were 40-fold more active than heparin in inhibiting the classical pathway. They were, however, as active as heparin in inhibiting the alternative pathway. In addition, we have developed a haemolytic test based on the CH50 protocol, which allows discrimination between activators and inhibitors of complement proteins. Although the mannose content within the different fucan fragments did not vary, the galactose and glucuronic acid contents increased with increasing activity, suggesting that these residues should be essential for full anticomplementary activity. Meanwhile, sulphate groups appeared to be necessary, but were clearly not a sufficient requirement for anticomplementary activity of fucans. Taken together, these data illustrate the prospects for the use of fucans as potential anti-inflammatory agents.

Animals↗
PubMed1991

Interaction of the envelope glycoprotein of human immunodeficiency virus with C1q and fibronectin under conditions present in human saliva.

Human saliva has been shown to reduce the infectivity of human immunodeficiency virus (HIV) particles in vitro. The factors in human saliva involved in this inhibition of HIV infectivity are unknown, although the salivary sediment of normal individuals has the major HIV neutralizing activity. Interestingly, the first complement component (C1) has been detected on the surface of the salivary sediment in the whole saliva of normal individuals. At the relatively low ionic strength of saliva, we determined that purified human C1q bound with high affinity to the envelope glycoprotein of HIV. Normally, the interaction of the C1q globular heads with immune complexes causes C1 activation. However, direct interactions between C1 and rgp120 (or rgp160) did not lead to C1 fixation, as determined by hemolytic studies with rate-limiting levels of C1, nor did rgp120 cause C1 activation as determined by activated C1s-mediated C4 conversion in normal human serum. Using ELISA, it was observed that intact C1, with the C1r2C1s2 tetramer associated with the collagen-like stem of C1q, did not bind to immobilized rgp120, whereas free C1q did bind. In addition, digestion of the C1q stem portion with collagenase completely eliminated its binding to rgp120. These findings suggest that the collagen-like stem region of C1q, rather than the globular heads, may participate in the binding to the envelope glycoprotein of HIV. Fibronectin, which is present in submandibular saliva, appeared to bind to rgp120 and to enhance the interaction of C1q with rgp120. It is conceivable that C1q and fibronectin, in binding and sequestering HIV particles (i.e. to the salivary sediment), may play an important role in the reduction of HIV transmission via saliva. Further studies will be needed to test the latter speculation.

Blotting, Western↗