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Extracellular Histones Inhibit Complement Activation through Interacting with Complement Component 4
Abstract<p>Complement activation leads to membrane attack complex formation, which can lyse not only pathogens but also host cells. Histones can be released from the lysed or damaged cells and serve as a major type of damage-associated molecular pattern, but their effects on the complement system are not clear. In this study, we pulled down two major proteins from human serum using histone-conjugated beads: one was C-reactive protein and the other was C4, as identified by mass spectrometry. In surface plasmon resonance analysis, histone H3 and H4 showed stronger binding to C4 than other histones, with KD around 1 nM. The interaction did not affect C4 cleavage to C4a and C4b. Because histones bind to C4b, a component of C3 and C5 convertases, their activities were significantly inhibited in the presence of histones. Although it is not clear whether the inhibition was achieved through blocking C3 and C5 convertase assembly or just through reducing their activity, the outcome was that both classical and mannose-binding lectin pathways were dramatically inhibited. Using a high concentration of C4 protein, histone-suppressed complement activity could not be fully restored, indicating C4 is not the only target of histones in those pathways. In contrast, the alternative pathway was almost spared, but the overall complement activity activated by zymosan was inhibited by histones. Therefore, we believe that histones inhibiting complement activation is a natural feedback mechanism to prevent the excessive injury of host cells.</p>
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Publication Date
Sun Apr 26 2020
Journal Name
Iraqi Journal Of Science
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Publication Date
Mon May 28 2018
Journal Name
Iraqi Journal Of Science
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Publication Date
Wed Mar 01 2023
Journal Name
Baghdad Science Journal
Stability of Complement Degree Polynomial of Graphs

     A graph is a structure amounting to a set of objects in which some pairs of the objects are in some sense related. The objects correspond to mathematical abstractions called vertices (also called nodes or points) and each of the related pairs of vertices is called an edge (also called link or line). A directed graph is a graph in which edges have orientation. A simple graph is a graph that does not have more than one edge between any two vertices and no edge starts and ends at the same vertex.  For a simple undirected graph G with order n, and let  denotes its complement. Let δ(G), ∆(G) denotes the minimum degree and maximum degree of G respectively. The complement degree polynomial of G is the polynomial CD[G,x]= , where C

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Publication Date
Mon Oct 01 2007
Journal Name
Journal Of The Faculty Of Medicine Baghdad
C3 and C4 complement components in autoimmune hepatitis.

Background: . Autoimmune hepatitis (AIH) is an unresolving inflammation of the liver of unknown cause associated with interface hepatitis on histological examination,hypergammaglobulinemia and presence of circulating autoantibodies. Antibody-mediated tissue injury might be responsible for tissue injury in AIH therefore; a number of studies have been focused on the complement system in these patients .
The aim of the study is to estimate the level of complement (C3 and C4) in different types of Autoimmune hepatitis (AIH).
Methods: The study M’as performed on 73 Iraqi patients with autoimmune hepatitis (AIH), attending the teaching hospital for gastroenterology and liver disease in a period betM'een November 2003 and July 2004. : A

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Publication Date
Fri Dec 30 2022
Journal Name
Iraqi Journal Of Science
Fully Prime Semimodule, Fully Essential Semimodule and Semi-Complement Subsemimodules

      The concept of semi-essential semimodule has been studied by many researchers.

     In this paper, we will develop these results by setting appropriate conditions, and defining new properties, relating to our concept, for example (fully prime semimodule, fully essential semimodule and semi-complement subsemimodule) such that: if for each subsemimodule of -semimodule  is prime, then  is fully prime. If every semi-essential subsemimodule of -semimodule  is essential then  is fully essential. Finally, a prime subsemimodule  of  is called semi-relative intersection complement (briefly, semi-complement) of subsemimodule  in , if , and whenever  with  is a prime subsemimodule in , , then .  Furthermore, some res

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Publication Date
Thu Oct 01 2009
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Increased Frequency of Complement C4 "Null" Alleles in Autoimmune Hepatitis

Background: Human leukocyte antigen (HLA) is the most polymorphic genetic system in man. The genes of this region influence susceptibility to certain diseases.
Patients and methods: Immunofixation test is the method used to asses C4 polymorphism of 100 blood samples of 60 AIH patients and 40 healthy normal controls.
Results: An increased frequency of C4A*Q0 was observed for patients group versus control group with P-value (0.003).
Conclusions: This finding demonstrated that C4A*Q0 might play a role in AIH susceptibility.

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Publication Date
Sun Dec 06 2015
Journal Name
Baghdad Science Journal
The Study of Serum Complement C3, C4 and Immunoglobulin E IgE in Psoriasis Patients

The present study was aimed to find out the role of humoral immunity in the pathogenesis of psoriasis. Complements C3, C4 and immunoglobulin IgE .The study included 55 Iraqi patients with psoriasis 30 (15 females ,15 males) were untreated with any drugs. The other patient group consisted of 25 (9 female and 16 male) treated with a biological treatment (infliximab) ,and 30 (13 males ,12 females) healthy control group. Blood sample were withdrawn (5) ml of venous blood for both patients and members of the control ,to conduct the Immunological tests to determine the quantitative for each of total IgE by using (ELISA) and C3,C4 by Single Radial Immunodiffuse (SIRD). The results showed significant increase in the level of probability (P <0.0

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Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Inflammatory role of some cytokines, immunoglobulins and complement proteins in immunopathogenesis of renal failure in a sample of Diyala province patients

This study was conducted in Diyala province for renal failure patients during the periods August 2015 - April 2016. Hundred renal failure patients were enrolled in the study after diagnosis by the consultant physician at Ibn-Sina Center for Dialysis in Baquba Teaching Hospital according to criteria adopted by the World Health Organization for diagnosis of renal failure disease. The number of males in patient’s sample was 61 (61%) and females was 39 (39%) with an age range of 10 – 88 year (44.7 ± 22.1 year). In addition, the study included 50 apparently healthy individuals and considered as a group control, in which the number of males and females was similar (25 individual), with an age range of 18 – 88 year (51.7 ± 17.3 year). The

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Publication Date
Tue Nov 19 2024
Journal Name
Iraqi Journal Of Science
EXTRACELLULAR SUPEROXIDE DISMUTASE CHANGES IN PATIENTS WITH DIFFERENT BRAIN TUMORS

The Specific activity of extracellular superoxide dismutase (EC-SOD) was measured in healthy persons and in patients with benign and malignant brain tumors. The results show decrease of the EC-SOD specific activity in sera of patients with benign and malignant brain tumors in comparison to that of control group.This study concentrated on studying the changes that occur in sera EC-SOD activity of patients with benign and malignant brain tumors, in comparison to that of normal individuals. The result also revealed that this isoenzyme is present in many different molecular weights forms (as judged by polyacrylamide gel electrophoresis), some of these with no enzymatic activity. Conversion among these forms occurs in the malignant sera

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Publication Date
Mon Feb 01 2021
Journal Name
Iop Conference Series: Materials Science And Engineering
On modelling and adaptive control of a linear smart beam model interacting with fluid
Abstract<p>This paper deals with modelling and control of Euler-Bernoulli smart beam interacting with a fluid medium. Several distributed piezo-patches (actuators and/or sensors) are bonded on the surface of the target beam. To model the vibrating beam properly, the effect of the piezo-patches and the hydrodynamic loads should be taken into account carefully. The partial differential equation PDE for the target oscillating beam is derived considering the piezo-actuators as input controls. Fluid forces are decomposed into two components: 1) hydrodynamic forces due to the beam oscillations, and 2) external (disturbance) hydrodynamic loads independent of beam motion. Then the PDE is discretized usi</p> ... Show More
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