Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.11.1.7 (peroxidase)
 65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human recombinant tumor necrosis factor-alpha (rTNF-alpha) was administered to normal Fischer 344 rats by stereotaxic intracerebral (IC) injection. Animals received a single injection of either 6 x 10(4) U rTNF-alpha or excipient in their right parietal lobe. Others received three consecutive daily injections of either 6 x 10(4) U rTNF-alpha or excipient to examine effects of higher accumulative doses. Histological examination of the brain revealed that both single and multiple IC injections of rTNF-alpha triggered an immigration of circulating leukocytes into the site of TNF-alpha injection. After one injection, this cell population was composed mainly of macrophages and neutrophils. Maximal leukocytic influx occurred by 48 h and was composed mostly of neutrophils which were limited to the injection site and perivascular space. Quantitation of the inflammatory reaction by measurement of tissue myeloperoxidase levels supported these histological observations. One day after multiple rTNF-alpha injections, leukocytic adhesion to endothelium, vascular cuffing and leukocytic infiltration into the neuropil was observed at levels comparable to those seen 3 days following a single rTNF-alpha injection. We conclude that while one or more IC injection(s) of 6 x 10(4) U rTNF-alpha was well tolerated in normal rats, at this dose the cytokine triggers a pronounced leukocytic infiltration at the site of injection. These results support a role for TNF-alpha as a mediator in inflammatory responses within the central nervous system.
 ...
PMID:Histopathological effects of intracerebral injections of human recombinant tumor necrosis factor-alpha in the rat. 128

Vascular injury has been induced in rat lung and dermis after deposition of IgG immune complexes (BSA-anti-BSA complexes). By the use of antibodies to TNF-alpha and IL-1 and employment of the IL-1R antagonist, the requirements for these cytokines have been evaluated. In lung, both TNF-alpha and IL-1 were required for the full expression of injury. Protection was related to the dose of cytokine-blocking agent employed and was directly correlated with diminished tissue content of myeloperoxidase (MPO). In the dermis, IL-1 was required for the full expression of injury; blocking of IL-1 protected the tissue from injury in a manner that correlated with reduced MPO content. However, anti-TNF-alpha provided no protection against dermal vascular injury and failed to reduce MPO content. In contrast, the local injection of either TNF-alpha or IL-1 beta enhanced IgG immune complex-induced dermal vascular injury, proportional to the increased tissue content of MPO, indicating that the rat dermis is reactive to both cytokines. By the employment of immunohistochemical approaches, it was demonstrated that, after deposition of immune complexes, TNF-alpha and IL-1 were readily demonstrated in lung macrophages, whereas in the dermis IL-1, but not TNF-alpha, was present in a granular pattern within interstitial cells. The immunohistochemical data are consistent with the patterns of protective effects of anti-IL-1, IL-1R antagonist and anti-TNF-alpha in the two organs. As expected, blocking of TNF-alpha or IL-1 had no protective effects on acute lung injury produced by systemic C activation after i.v. infusion of the cobra venom factor. The data suggest fundamental differences in the requirements for cytokines in lung and dermal vascular injury after deposition of IgG immune complexes.
 ...
PMID:Immune complex-induced lung and dermal vascular injury. Differing requirements for tumor necrosis factor-alpha and IL-1. 131 4

C receptor-1 is a protein involved in the regulation of C3 and C5-convertases. Recombinant human soluble C receptor-1 has recently been produced and shown to reduce infarct size in a rat model of myocardial ischemia/reperfusion injury. The present study aimed to investigate whether recombinant human soluble C receptor-1 exerts any protective effect on pulmonary injury produced in a rodent model of adult respiratory distress syndrome. In this model, Escherichia coli endotoxin (LPS, 0.1 microgram/kg) combined with platelet-activating factor (1 pmol/kg/min over 60 min, n = 10) caused microvascular lung injury characterized by elevation of myeloperoxidase activity, deposition of C3 and C5b-9 on the endothelium of pulmonary vessels, and pulmonary edema. Furthermore, bronchoalveolar lavage revealed increased neutrophil count and elevated protein concentration. These pulmonary responses were associated with elevated serum TNF-alpha. Pretreatment (10 min, i.v.) with recombinant human soluble C receptor-1 at 10 mg/kg (n = 13), but not at 1 mg/kg, prevented the LPS/platelet-activating factor-induced pulmonary edema (p less than 0.01) and changes in the bronchoalveolar lavage fluid cell count (p less than 0.01) and protein concentration (p less than 0.05), and attenuated the deposition of C3 and C5b-9 to lung vessels. There was no effect on lung myeloperoxidase activity and serum TNF-alpha. Also, C depletion by cobra venom factor (500 U/kg, i.v.) eliminated the pulmonary edema and elevated leukocyte count in bronchoalveolar lavage fluid, but had no effect on lung myeloperoxidase activity and serum TNF-alpha. These data suggest that C factors may play an important role in the pathophysiology of adult respiratory distress syndrome.
 ...
PMID:Role of complement in endotoxin/platelet-activating factor-induced lung injury. 132 80

Leukemia inhibitory factor (LIF) is known to exhibit multiple functions by regulating the growth and differentiation of multiple normal cell types as well as malignant cells. To have a better understanding of the role of LIF, it is important to determine the level of LIF in various biological samples by developing an easy, sensitive and LIF specific assay. In this study, we have established a double monoclonal antibody (mAb) based ELISA. Four hybridoma cell lines (D3.14.1, D4.16.9, D25.1.4 and D62.3.2) secreting murine monoclonal antibodies (mAbs) against recombinant human leukemia inhibitory factor (rHuLIF) were produced by immunization of BALB/c mice with rHuLIF and by fusing immune spleen cells with P3X63Ag8U.1 myeloma cells. These mAbs each belong to the IgG1 isotype and have unique isoelectrofocusing point patterns. All four mAbs were shown to have high affinities for rHuLIF (Kd = 7 x 10(-10) to 6 x 10(-11) M) and were able to recognize the native as well as the reduced rHuLIF in an immunoblotting assay. All these mAbs showed no cross-reactivities to IL-1, IL-3, IL-6, TNF-alpha, GCSF and GMCSF. MAb D3.14.1 showed a weak binding to Oncostatin M but not to rMuLIF whereas the other three mAbs D4.16.9, D25.1.4 and D62.3.2 showed cross-reactivity to rMuLIF but not to Oncostatin M. Data obtained from a competitive binding enzyme-linked immunosorbent assay (ELISA) suggested that these four mAbs recognized different epitopes on rHuLIF. Using mAb D4.16.9 as coat antibody and horseradish peroxidase (HRP) conjugated mAb D3.14.1 as the conjugate antibody we established a double mAb based ELISA specific for human LIF which could detect as little as 100 pg/ml and 10 pg/ml of rHuLIF in the absence and in the presence of the ELAST ELISA amplification system, respectively. The addition of serum had very minimal effect on this ELISA.
 ...
PMID:Detection of human leukemia inhibitory factor by monoclonal antibody based ELISA. 138 38

Northern blot analysis of mouse uterine RNA showed that IL-1 (alpha and beta), and TNF-alpha mRNA were abundant on day (D) 1 of pregnancy, reduced on D2, and remained basal throughout the remainder of the preimplantation period (D3 and D4). Elevated IL-1 beta and TNF-alpha mRNA levels on D1 were accompanied by increased levels of immunoreactive protein in uterine cytosol preparations as determined by ELISA. In situ hybridization detected IL-1 beta mRNA in cells located in the endometrial stroma and concentrated in subepithelial regions on D1. Immunocytochemical localization of IL-1 beta and TNF-alpha identified cells scattered throughout the endometrial stroma, but more concentrated in the subepithelial region on D1. On D3 and D4, cytokine-immunopositive cells decreased in number and became located predominantly at the endometrial-myometrial junction. Histochemical localization of peroxidase as a marker predominantly for eosinophils showed an abundance of these cells in the D1 uterus. The distribution of peroxidase-positive cells in the uterus followed the same temporal and spatial changes as cytokine-immunopositive cells during the preimplantation period. These data document the occurrence of an inflammatory response in the uterus on D1 of pregnancy, and demonstrate that as the preimplantation period progresses the distribution of inflammatory cells changes from the subepithelial region of the endometrial stroma to the periphery of the uterus at the endometrial-myometrial junction. Mechanisms regulating the uterine inflammatory response on D1 were investigated. Cytokine mRNA levels were not significantly elevated during the estrous cycle or after treatment of adult ovariectomized mice with estradiol-17 beta. In contrast, mating with vasectomized males resulted in an inflammatory response on D1 of pseudopregnancy similar to that on D1 of normal pregnancy, whereas mechanical stimulation of the uterine cervix failed to elicit such a response. These results strongly suggest a role for some factor(s) in the ejaculate, other than spermatozoa, in the initiation of a uterine inflammatory response after mating, but an effect of the act of mating cannot be excluded.
 ...
PMID:Activation and distribution of inflammatory cells in the mouse uterus during the preimplantation period. 154 14

Studies of neutrophil-dependent endothelial injury were made using normal neutrophils (nl-PMN, i.e., normal polymorphonuclear neutrophils) and PMN obtained from a patient with X-linked chronic granulomatous disease (CGD-PMN). Layering of nl-PMN on bovine pulmonary microvessel endothelial monolayers (ratio 10:1) followed by challenge with phorbol 12-myristate 13-acetate (PMA; 5 x 10(-9) M) resulted in a 190% increase in 125I-labeled albumin permeability across the monolayers. Pretreatment of endothelial monolayers with tumor necrosis factor-alpha (TNF-alpha; 200 or 1,000 U/ml) further enhanced the increase in permeability after stimulation of nl-PMN with PMA. In contrast, challenge of CGD-PMN layered on endothelial cells with PMA did not increase permeability, and the effect was not enhanced by pretreating the endothelial cells with TNF-alpha. Nl-PMN, but not CGD-PMN, generated superoxide anion on stimulation with PMA (42.5 +/- 0.7 vs. 6.5 +/- 0.6 nM.10(6) PMN-1.h-1). PMA also induced degranulation of nl-PMN as measured by release of elastase (2.32 +/- 0.12 micrograms/10(6) PMN) and myeloperoxidase (173.8 +/- 1.9 U/10(6) PMN) into the medium, whereas release by CGD-PMN was markedly reduced (elastase release of 0.88 +/- 0.04 microgram/10(6) PMN and myeloperoxidase release of 82.6 +/- 19.4 U/10(6) PMN). The adherence response of nl-PMN and CGD-PMN to the endothelial cells after PMA stimulation was similar (79.5 +/- 11.8% nl-PMN and 64.0 +/- 1.9% CGD-PMN). Therefore, the PMN respiratory burst, with the resultant generation of oxidants and PMN-derived proteases, is required to increase endothelial permeability even in the face of increased endothelial adhesivity.
 ...
PMID:Neutrophils from chronic granulomatous disease fail to increase endothelial permeability. 165 87

Two 'inverse sandwich' enzyme immunoassays (ELISAs) were developed for the detection and quantification of antibodies to human tumor necrosis factor (TNF-alpha) and lymphotoxin (TNF-beta), respectively. In these one-step assays, antibodies present in the sample linked antigen which had been covalently coupled to horseradish peroxidase to antigen bound to a solid phase (microtiter plates). The limits of detection of the assays were lower than those of neutralization bioassays; antibodies to TNF-alpha and TNF-beta being detected at concentrations as low as 2 ng/ml and 0.5 ng/ml, respectively, and no cross-reactivity was observed. The advantages of these ELISAs over other assay methods currently in use for the detection of antibodies include: (i) the convenience of the microtiter plate format and its suitability for testing large numbers of samples; (ii) the absence of radioactive tracers and precipitation steps; (iii) the high stability of the reagents; (iv) the avoidance of second antibodies and, thus, the possibility of testing samples from various species without modification of the assay and (v) the ability to detect low-affinity antibodies due to the absence of competitive reactions. The assays may be used without modification for the detection of antibodies in serum samples from both man and laboratory animals as well as in other samples such as hybridoma supernatants.
 ...
PMID:Highly sensitive enzyme immunoassays for antibodies to human tumor necrosis factor (TNF-alpha) and lymphotoxin (TNF-beta). 169 19

Lactoferrin (LF) and myeloperoxidase (MPO) are glycoproteins synthesized in early myeloid cells (promyelocytes, myelocytes) and stored in granules of polymorphonuclear neutrophilic granulocytes. Both proteins are involved in the host inflammatory response, and LF has been found to have myelosuppressive activity in vivo and in vitro. Little is known, however, about the regulation of their production. We investigated the stability of LF and MPO mRNA and the effects of purified recombinant human TNF-alpha on LF and MPO levels in normal human bone marrow. Low density human bone marrow cells were cultured in the presence or absence of actinomycin D (10 micrograms/ml) or TNF-alpha (200 U/ml). LF and MPO RNA levels were analyzed by Northern blots using, respectively, a 650-bp insert from the plasmid pHL41, and a 2.3-kb insert from the plasmid pMPO2 as probes. It was found that: 1) LF mRNA is a fairly stable molecule, with a half-life of between 8 and 9 h, whereas MPO is less stable, with a half-life of between 4 and 5 h; 2) TNF-alpha decreases both LF and MPO mRNA levels, an effect seen by 24 h with MPO mRNA and 48 h with LF mRNA; 3) nuclear run-on assays revealed that TNF decreases transcription of the LF gene by 70% and the MPO gene by 50%; and 4) the suppressive effect of TNF-alpha on LF and MPO mRNA levels is not due to cell killing or selective differentiation and is reversible.
 ...
PMID:Regulation of human bone marrow lactoferrin and myeloperoxidase gene expression by tumor necrosis factor-alpha. 170 77

Three hybridoma cell lines secreting monoclonal IgG antibodies specific for human tumor necrosis factor-binding protein I (TNF-BP I), the extracellular domain of the 60 kDa TNF receptor, were developed by fusion of spleen cells from mice immunized with TNF-BP I purified from urine. The antibodies recognize three different epitopes on TNF-BP I. Two of the antibodies were used to develop a two-site ('sandwich') enzyme immunoassay with horseradish peroxidase as the marker enzyme. The assay was able to measure TNF-BP I in serum, urine and cell culture supernatants with a sensitivity of about 200 ng/l and a precision better than 10%. TNF-BP I was detected in the serum of healthy individuals at a mean concentration of 2.1 +/- 1.0 micrograms/l (mean +/- standard deviation; range, 0.52-5.4 microgram/l, n = 42); no significant difference was seen in patients with chronic polyarthritis (2.3 +/- 0.79 micrograms/l; n = 15). Serum TNF-BP I was significantly elevated in patients with burns (6.5 +/- 1.7 micrograms/l; n = 10) and markedly increased in patients with renal failure (49 +/- 17 micrograms/l; n = 6). TNF-BP I was also detectable in urine from normal individuals (2.2 +/- 1.2 micrograms/l; range 0.78-4.3 micrograms/l; n = 16). Culture supernatants of several human tumor cell lines also contained TNF-BP I. The assay will be a useful tool to detect activation of the TNF receptor by the physiological ligands, TNF-alpha and TNF-beta, as well as transmodulation by other mediators in various pathological conditions.
 ...
PMID:A monoclonal antibody-based enzyme immunoassay for quantitation of human tumor necrosis factor binding protein I, a soluble fragment of the 60 kDa TNF receptor, in biological fluids. 191 33

Eosinophils (EOs) participate in a variety of inflammatory states characterized by endothelial cell damage, such as vasculitis, pneumonitis, and endocarditis. We find that 100 U/ml TNF-alpha/cachectin (TNF), a concentration attainable in the blood of humans with parasitic infestations, stimulates highly purified populations of EOs to damage human umbilical vein endothelial cells (HUVEC), a model of human endothelium. This TNF-dependent EO cytotoxicity is strongly inhibited by heparin and methyprednisolone but unaffected by the platelet-activating factor antagonist BN52012 or scavengers of superoxide anion and H2O2, superoxide dismutase and catalase. However, addition of a physiologically relevant concentration of Br- (100 microM) enhances EO/TNF damage to HUVEC, implicating the possible participation of EO peroxidase (EPO) in the killing mechanism. EOs adherent to FCS-coated plastic wells more than double their production of superoxide anion and the cytotoxic EPO-derived oxidant HOBr when exposed to TNF, showing that TNF activates the respiratory burst of EOs attached to a "physiologic" surface. Unlike PMNs, EOs were not irreversibly activated to kill unopsonized endothelium by previous exposure to TNF, and did not degranulate or upregulate CR3 expression as detected by Mo1 in the presence of 100 U/ml TNF. HUVEC exposed 18 h to TNF were considerably more susceptible to lysis by PMA-activated EOs and reagent H2O2, demonstrating a direct effect of TNF upon endothelium, perhaps through inhibition of antioxidant defenses. These findings suggest that abnormally elevated serum levels of TNF may provoke EOs to damage endothelial cells and thereby play a role in the pathogenesis of tissue damage in hypereosinophilic states.
 ...
PMID:Tumor necrosis factor alpha/cachectin stimulates eosinophil oxidant production and toxicity towards human endothelium. 197 79


1 2 3 4 5 6 7 8 9 10 Next >>