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Complement Activity (complement + activity)

Distribution by Scientific Domains

Medical Sciences	38%
Earth and Environmental Science	38%
Life Sciences	23%

Kinds of Complement Activity

alternative complement activity

Selected Abstracts

Modulation of the innate immune response of rohu Labeo rohita (Hamilton) by experimental freshwater lice Argulus siamensis (Wilson) infection

AQUACULTURE RESEARCH, Issue 9 2010
Shailesh Saurabh
Abstract The study was undertaken to determine the modulation in innate immune response of rohu (Labeo rohita) during experimental freshwater lice Argulus siamensis infection. Results showed that serum ,-2 macroglobulin (,-2M) activity, ceruloplasmin level and alternative complement activity were significantly (P<0.05) lower in fish at different degrees of lice infection in comparison with uninfected control. No significant difference (P>0.05) in haemagglutination titre was observed in fish with low- and high-degree lice infections as compared with uninfected control. The serum lysozyme level was significantly (P<0.05) lower in low degree of lice infection as compared with control fish. The total serum antiprotease, myeloperoxidase activity and total protein level were not significantly different (P>0.05) in different degrees of lice-infected fish with respect to the control fish. The study indicated that A. siamensis infection modulated the immune system of rohu by suppressing the ,-2M, serum complement activities and ceruloplasmin level and through induction of stress response. The baseline data obtained in the present study have tremendous importance in understanding the susceptibility of rohu to different degrees of parasitosis and might be useful in controlling this dreaded ectoparasitic infection in fish. [source]

Testosterone and innate immune function inversely covary in a wild population of breeding Dark-Eyed Juncos (Junco hyemalis)

FUNCTIONAL ECOLOGY, Issue 5 2006
T. J. GREIVES
Summary 1Innate immunity refers to the non-specific components of the primary immune response, which act broadly to destroy pathogens. Effective innate immune responses may save an individual the energetic costs associated with activating subsequent specific immune responses. 2Testosterone can suppress immune function in vitro and in vivo. Most studies examining testosterone's effects on immunity have focused on experimentally elevated testosterone and acquired immune responses (e.g. humoral and cell-mediated responses to foreign antigens). Few studies have investigated the relationship between endogenous levels of testosterone and innate immunity. 3In a wild breeding population of Dark-Eyed Juncos (Junco hyemalis Linnaeus), we asked whether endogenous levels of testosterone measured at several points during the breeding season covaried with two components of innate immunity: total levels of non-specific immunoglobulin-G (IgG), and complement levels. 4Testosterone levels were significantly negatively correlated with both total IgG and complement activity. Both immune measures were also positively correlated with body mass. Taken together with experimental results from the same species, these results suggest that elevated testosterone levels may compromise innate as well as acquired immune function. [source]

QTL for traits related to humoral immune response estimated from data of a porcine F2 resource population

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 3 2009
K. Wimmers
Summary This study aimed to map quantitative trait loci (QTL) for traits related to humoral innate immune defence. Therefore, haemolytic complement activity in the alternative and the classical pathway, serum concentration of C3c and of haptoglobin (HP) were measured in blood samples obtained from F2 piglets (n = 457) of a porcine F2 resource population before and after Mycoplasma hyopneumoniae, Aujeszky's disease virus (Suid herpesvirus I, SuHVI) and porcine reproductive and respiratory syndrome virus (PRRSV) vaccination at 6, 14 and 16 weeks of age. Animals were genotyped at 88 autosomal markers. QTL analysis was performed under the line cross and the half sib. Phenotypic data were adjusted for systematic effects by mixed models with and without repeated measures statement. In total, 46 and 21 estimated QTL positions were detected with genome-wide significance at the 0.05 and 0.01 level, respectively. The proximal region of SSC2 (orthologous to HSA11 0,70 Mb), the distal region of SSC4 (HSA1 95,155 Mb), and the intermediate region of SSC16 (HSA5 0,73 Mb and 150,174 Mb) showed a clustering of estimated QTL positions for complement activity based on the different models. A common genetic background, i.e. a single true QTL, might underlie these QTL positions for related traits. In addition, QTL for antibody titres were detected on SSC1, 2, 6 and 7. With regard to number and magnitude of their impact, QTL for humoral innate immune traits behave like those for other quantitative traits. Discovery of such QTL facilitates the identification of candidate genes for disease resistance and immune competence that are applicable in selective breeding and further research towards improving therapeutic and prophylactic measures. [source]

Growth Performance, Immune Response, and Resistance to Streptococcus iniae of Nile Tilapia, Oreochromis niloticus, Fed Diets Containing Various Levels of Vitamins C and E

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2010
Chhorn Lim
Growth, immunity, and resistance of Nile tilapia to Streptococcus iniae challenge were evaluated after feeding diets supplemented with vitamin C (0, 100, 2000 mg/kg) and E (0, 50, 500 mg/kg) for 12 wk. Supplementation of 100 mg vitamin C/kg to the basal diet was sufficient to increase growth and feed efficiency. The amount of vitamin E present in the basal diet (23.1 mg/kg) was sufficient to promote good growth and feed efficiency, but adding 50 mg vitamin E/kg was necessary to increase survival. Liver vitamin C and E concentrations increased with increasing dietary concentrations of the corresponding vitamin. Dietary vitamin E concentrations had no effect on liver vitamin C concentration, but increasing dietary vitamin C increased liver vitamin E. Although hematology was generally unaffected by dietary vitamin E, significantly lower red blood cell count and hemoglobin and higher mean corpuscular volume were observed in fish fed the vitamin C-unsupplemented diets. Total immunoglobulin and lysozyme activity were significantly higher and lower, respectively, in fish fed 2000 mg/kg vitamin C diets. Vitamin E at 500 mg/kg diet significantly decreased alternative complement activity. Dietary concentrations of vitamin C had no effect on mortality following S. iniae challenge, but mortality significantly decreased in fish fed vitamin E,supplemented diets. [source]

Effects of Carbohydrate-Rich Alternative Feedstuffs on Growth, Survival, Body Composition, Hematology, and Nonspecific Immune Response of Black Pacu, Colossoma macropomum, and Red Pacu, Piaractus brachypomus

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2009
Rebecca Lochmann
To facilitate economical culture of black pacu, Colossoma macropomum, and red pacu, Piaractus brachypomus, in the Amazon region of South America, we assessed locally available alternative energy sources for practical diets. We tested the effects of control diets (containing wheat products) versus diets with different Amazonian feedstuffs (yucca, Manihot sculenta, plantain, Musa paradisiaca, or pijuayo, Bactris gasipaes) on the performance of the pacus in three feeding trials. Black pacu (22.5 ± 0.03 g; Trial 1) or red pacu (2.56 ± 0.01 g; Trial 2) were fed diets containing 30% wheat bran (control) or cooked or uncooked yucca, plantain, or pijuayo for 12 wk. In Trial 3, larger black pacu (86.9 ± 6.4 g) were grown to market size in 24 wk on similar diets. Weight gain, feed conversion, survival, alternative complement activity, and lysozyme were similar among diets. Hepatosomatic index, liver glycogen, and dry matter were affected by diet in Trials 1 and 2, but effects were not consistent among trials. In Trial 3, protein efficiency ratio was lower in fish fed the diet containing wheat middlings. However, relative to wheat bran or wheat middlings, all feedstuffs tested were effective energy sources for juvenile black pacu and red pacu. [source]

Flavonoids from the leaves of Litsea japonica and their anti-complement activity

PHYTOTHERAPY RESEARCH, Issue 4 2005
Sun-Young Lee
Abstract Four flavonoids, epicatechin (1), afzelin (2), quercitrin (3), and tiliroside (4), were isolated from the leaves of Litsea japonica (Thunb.) Jussieu (Lauraceae). The structures of compounds were identified by comparing their chemical and spectral data with those previously reported. The flavonoids (1,4) were tested for their anti-complement activity against classical pathway of complement system. Compounds 2,4 showed inhibitory activity against complement system with IC50 values of 258, 440, and 101 µm, respectively, whereas 1 was inactive. For the evaluation of the structure-activity relationship of 5,7-dihydroxyflavones, myricitrin (5) from Juglans mandshurica also tested for it's anti-complement activity and is inactive in this assay system. Furthermore, compounds 2, 3, and 5 were hydrolyzed with naringinase to give kaempferol (2a), quercetin (3a), and myricetin (5a), and these were also tested for their activity. Of the three aglycones, 2a exhibited anti-complement activity with an IC50 value of 730 µM, while 3a and 5a were inactive. The inhibitory potencies of 2, 2a, 3, 3a, 5, and 5a against complement activity increased in inverse proportion to number of free hydroxyls on B-ring of 5,7-dihydroxyflavone. Of the compounds tested, 4 showed the most potent inhibitory activity against the complement system. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Impact of Thrombocytopenia on Survival of Baboons with Genetically Modified Pig Liver Transplants: Clinical Relevance

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010
B. Ekser
A lack of deceased human donor livers leads to a significant mortality in patients with acute-on-chronic or acute (fulminant) liver failure or with primary nonfunction of an allograft. Genetically engineered pigs could provide livers that might bridge the patient to allotransplantation. Orthotopic liver transplantation in baboons using livers from ,1,3-galactosyltransferase gene-knockout (GTKO) pigs (n = 2) or from GTKO pigs transgenic for CD46 (n = 8) were carried out with a clinically acceptable immunosuppressive regimen. Six of 10 baboons survived for 4,7 days. In all cases, liver function was adequate, as evidenced by tests of detoxification, protein synthesis, complement activity and coagulation parameters. The major problem that prevented more prolonged survival beyond 7 days was a profound thrombocytopenia that developed within 1 h after reperfusion, ultimately resulting in spontaneous hemorrhage at various sites. We postulate that this is associated with the expression of tissue factor on platelets after contact with pig endothelium, resulting in platelet and platelet-peripheral blood mononuclear cell(s) aggregation and deposition of aggregates in the liver graft, though we were unable to confirm this conclusively. If this problem can be resolved, we would anticipate that a pig liver could provide a period during which a patient in liver failure could be successfully bridged to allotransplantation. [source]

Across-line SNP association study of innate and adaptive immune response in laying hens

ANIMAL GENETICS, Issue 1 2010
F. Biscarini
Summary The aim of the present study was to detect quantitative trait loci (QTL) for innate and adaptive immunity in laying hens. For this purpose, the associations between 1022 single nucleotide polymorphism (SNP) markers and immune traits were studied in 583 hens from nine different layer lines. Immune traits were natural antibodies for keyhole limpet haemocyanin (KLH) and lipopolysaccharide (LPS) at 20, 40 and 65 weeks, acquired antibodies to the vaccinal virus of Newcastle disease at 20 weeks, and complement activity measured on sheep and bovine red blood cells at 20, 40 and 65 weeks. We adopted a novel approach based on across-line analysis and testing of the SNP-by-line interaction. Among lines, linkage disequilibrium is conserved at shorter distances than in individual lines; therefore, SNPs significantly associated with immune traits across lines are expected to be near the functional mutations. In the analysis, the SNPs that had a significant across-line effect but did not show significant SNP-by-line interaction were identified to test whether the association was consistent in the individual lines. Ultimately, 59 significant associations between SNPs and immune traits were detected. Our results confirmed some previously identified QTL and identified new QTL potentially involved in the immune function. We found evidence for a role of IL17A (chromosome 3) in natural and acquired antibody titres and in the classical and alternative pathways of complement activation. The major histocompatibility genes on chromosome 16 showed significant association with natural and acquired antibody titres and classical complement activity. The IL12B gene on chromosome 13 was associated with natural antibody titres. [source]

Novel complement inhibitor limits severity of experimentally myasthenia gravis,

ANNALS OF NEUROLOGY, Issue 1 2009
Jindrich Soltys DVM
Objective Complement mediated injury of the neuromuscular junction is considered a primary disease mechanism in human myasthenia gravis and animal models of experimentally acquired myasthenia gravis (EAMG). We utilized active and passive models of EAMG to investigate the efficacy of a novel C5 complement inhibitor rEV576, recombinantly produced protein derived from tick saliva, in moderating disease severity. Methods Standardized disease severity assessment, serum complement hemolytic activity, serum cytotoxicity, acetylcholine receptor (AChR) antibody concentration, IgG subclassification, and C9 deposition at the neuromuscular junction were used to assess the effect of complement inhibition on EAMG induced by administration of AChR antibody or immunization with purified AChR. Results Administration of rEV576 in passive transfer EAMG limited disease severity as evidenced by 100% survival rate and a low disease severity score. In active EAMG, rats with severe and mild EAMG were protected from worsening of disease and had limited weight loss. Serum complement activity (CH50) in severe and mild EAMG was reduced to undetectable levels during treatment, and C9 deposition at the neuromuscular junction was reduced. Treatment with rEV576 resulted in reduction of toxicity of serum from severe and mild EAMG rats. Levels of total AChR IgG, and IgG2a antibodies were similar, but unexpectedly, the concentration of complement fixing IgG1 antibodies was lower in a group of rEV576-treated animals, suggesting an effect of rEV576 on cellular immunity. Interpretation Inhibition of complement significantly reduced weakness in two models of EAMG. C5 inhibition could prove to be of significant therapeutic value in human myasthenia gravis. Ann Neurol 2009;65:67,75 [source]

Prebiotics in aquaculture: a review

AQUACULTURE NUTRITION, Issue 2 2010
E. RINGØ
Abstract A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools. [source]