Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003873 (rheumatoid arthritis)
 53,068 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of tenascin-X (Tn-X) was investigated in synovial samples from rheumatoid arthritis (RA), osteoarthritis (OA) and knee injuries, and in synovial membrane-like interface tissue (SMLIT) from aseptic loosening of total hip replacement (THR). An affinity purified rabbit antiserum against Tn-X was applied in avidin-biotin-peroxidase complex method. Double immunofluorescence labeling was used to assess the spatial relationship of Tn-X and Tn-C. All samples showed Tn-X immunoreactivity. Strong staining appeared in the lining and lining-like layers of RA and SMLIT samples, respectively. An intensive immunoreactivity was also found in pannus tissue in RA, and around multinucleate giant cells and polyethylene wear debris in SMLIT. Staining intensity/extent varied significantly in different samples in the following rank order: SMLIT, RA, OA, knee synovium membrane. Double labeling revealed two patterns of Tn-X/Tn-C distribution, reciprocal and co-localization. Our results suggest that Tn-X is an essential component of normal synovial membrane, and that inflammatory mediators may increase local Tn-X production. Tn-X distribution is not always reciprocal to that of Tn-C.
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PMID:Distribution of tenascin-X in different synovial samples and synovial membrane-like interface tissue from aseptic loosening of total hip replacement. 1098 35

A semi-quantitative ELISA for complement-fixing, IgG-containing immune complexes (IC) is described. The assay is based on the insolubilization of IC by polyethyleneglycol, their capture by solid-phase anti-C3 antibodies, reaction with peroxidase-labeled anti-IgG antibodies and incubation with a chromogenic peroxidase substrate. It was markedly improved by the use of a single-step procedure which simultaneously washed and precipitated the insolubilized immune complexes. Intra-assay and inter-assay coefficients of variation were lower than 8.6 and 14.7%, respectively. As expected, higher levels of circulating immune complexes, in relation to healthy individuals, were found in patients with American visceral leishmaniasis (AVL), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), with prevalences comparable to those described in the literature. The ELISA can be quickly assembled from reagents and plasticware widely available commercially, detects immune complexes fulfilling three different criteria and is more sensitive than a previously published method based on the same principles (detection limit for complement-sensitized aggregated IgG of 2 microg ml(-1) as compared with a detection limit above 16 microg ml(-1)).
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PMID:An improved anti-C3/IgG ELISA for quantification of soluble immune complexes. 1122 77

Creatine kinase (CK) was used as a marker molecule to examine the side effect of damage to tissues by indomethacin (IM), an effective drug to treat rheumatoid arthritis and gout, with horseradish peroxidase and hydrogen peroxide (HRP-H2O2). IM inactivated CK during its interaction with HRP-H2O2. Under aerobic conditions, inactivation of CK significantly decreased. CK in rat heart homogenate was also inactivated by IM with HRP-H2O2. When IM was incubated with HRP-H2O2, the maximum absorption of IM at 280 nm rapidly decreased and a new peak at 410 nm occurred with isosbestic points at 260 and 312 nm. In contrast, under anaerobic conditions, the spectral change of IM was almost absent, indicating IM was oxidized to the yellow substance by HRP-H2O2. Adding catalase strongly inhibited the production of yellow substance. Sodium azide also blocked the formation of yellow substance and the inactivation of CK. Electron spin resonance signals of IM carbon-centered radical were detected using 2-methyl-2-nitrosopropane during the interaction of IM with HRP-H2O2 under anaerobic conditions. Oxygen was consumed during the interaction of IM with HRP-H2O2. These results suggest that IM carbon-centered radicals may rapidly react with O2 to generate the peroxyl radicals. Sulfhydryl groups and tryptophane residues of CK decreased during the interaction of IM with HRP-H2O2. Other sulfhydryl enzymes, including alcohol dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase, were also readily inactivated during the interaction with HRP-H2O2. Sulfhydryl enzymes seem to be very sensitive to IM activated by HRP-H2O2.
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PMID:Inactivation of creatine kinase during the interaction of indomethacin with horseradish peroxidase and hydrogen peroxide: involvement of indomethacin radicals. 1124 19

An indirect competition immunoassay for the quantification of YKL-40 (cartilage gp-39, Chondrex) in guinea pig serum has been developed using egg yolk antibodies (IgY). The immune response of hens to YKL-40 was verified by immunoblot analyses. Highly specific antibodies were obtained 30 days after the first injection. The ELISA was developed in 96-well microtiter plates with quadruplicate determinations for each point. The assay was based on the ability of YKL-40 present in serum to displace the binding of antibodies to the coated antigen. An inhibition mixture containing standard YKL-40 or guinea pig serum, diluted 1/5, and primary antibodies, diluted 1/5000, was allowed to equilibrate for 2 h at room temperature and dispensed for 16 h at 4 degrees C in wells coated with 1 microg/ml of YKL-40. Detection was achieved by the addition of rabbit anti-chicken antibodies conjugated to peroxidase followed by tetramethylbenzidine. Specificity was assessed by parallelism between a dilution curve of serum and standard YKL-40. The sensitivity of detection was 10 ng/ml. Intra- and interassay coefficients of variation were both 8.7%. The analytical recovery was 101.5+/-5.4% (mean+/-standard deviation (SD), n=9). The YKL-40 concentration in serum from 12 adult guinea pigs was 330+/-216 ng/ml (mean+/-SD) with a lower value of 164 ng/ml and an upper value of 982 ng/ml. In contrast to the rat, a dilution curve of rabbit serum gave parallelism with the guinea pig standard, suggesting recognition of a similar epitope. Possible applications of the assay in the guinea pig include disease models where YKL-40 is overexpressed and could be used as a marker, i.e. osteoarthritis, rheumatoid arthritis, cancer, liver fibrosis, atherosclerosis and more generally, pathologies with increased tissue remodeling.
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PMID:Development of an enzyme-linked immunoassay for the quantification of YKL-40 (cartilage gp-39) in guinea pig serum using hen egg yolk antibodies. 1133 75

Stroke, or ischaemic brain damage, is of great geriatric importance being the third most common cause of death after cancer and heart diseases in developed countries. Despite such high frequency, its management has received inadequate attention. Many studies have shown the role of free radicals in the pathogenesis of ischaemic brain damage. Search for safe and effective antioxidant and free radial scavenger agents, therefore, appear to be a promising approach for stroke therapy. Gold, widely used in modern medicine for the treatment of rheumatoid arthritis, is highly valued for various medicinal uses in Indian systems of medicine. Traditional gold preparations are attributed with tonic/rejuvenating and antioxidant properties. Our earlier studies revealed interesting analgesic, immunostimulant, adaptogenic and glycogen sparing properties in these preparations, but their effects in cerebral ischaemia have not been investigated. This prompted us to initiate the present study using global and focal models of ischaemia in albino rats. Enzymatic parameters (lipid peroxidase, reduced glutathione, catalase, glutathione reductase, glutathione-S-transferase, glutatione peroxidase, superoxide dismutase, and glucose-6-phosphate dehydrogenase) were employed to assess ischaemic brain damage and its modulation. Significant restoration of altered values to near normal levels by Ayurvedic Swarna Bhasma and Unani Kushta Tila Kalan (25 mg/kg, orally for 10 days), suggest potentials for gold preparations in cerebrovascular diseases. The preparations deserve more scientific attention for possible therapeutic exploitation.
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PMID:Antioxidant/restorative effects of calcined gold preparations used in Indian systems of medicine against global and focal models of ischaemia. 1207 6

Monocyte chemoattractant protein-1 (MCP-1) is a potential therapeutic target for the treatment of several inflammatory conditions, including rheumatoid arthritis and chronic obstructive pulmonary disease. Current cell-based assays for MCP-1 use monocyte chemotaxis or calcium flux as a readout. Here, we describe an alternative bioassay based on MCP-1-induced phosphorylation of the mitogen-activated protein kinases (MAPK) p44 (ERK1) and p42 (ERK2). Adherent cells expressing the MCP-1 receptor CCR2B are treated with MCP-1 in 96-well plates in the presence or absence of inhibitors, fixed and permeabilized with methanol, and then probed with a monoclonal antibody that selectively recognizes the doubly phosphorylated form of p44/42 MAPK. Bound antibody is detected with a secondary antibody-peroxidase conjugate and a chromogenic substrate. The phosphorylation of p44/42 MAPK as detected in this assay peaks after 3-5 min of MCP-1 treatment, and the concentration of MCP-1 required for half-maximal p44/42 MAPK phosphorylation is 1-3 nM. MCP-1-induced phosphorylation of p44/42 MAPK is dependent upon the expression of CCR2B. The assay can be used for screening and characterization of small molecule inhibitors and antibodies blocking the binding of MCP-1 to its receptor. Since the assay is rapid and simple, it may represent a useful alternative to chemotaxis or calcium mobilization assays for the analysis of MCP-1 inhibitors.
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PMID:Development of a microplate bioassay for monocyte chemoattractant protein-1 based on activation of p44/42 mitogen-activated protein kinase. 1503 19

Assays for the analysis of antierythropoietin antibodies (anti-EPO Abs) currently suffer from a high degree of nonspecificity or are cumbersome and time consuming to perform. They are therefore not well suited for the analysis of large numbers of human sera samples, a task that has become increasingly important due to an increase in the number of patients developing anti-EPO Abs. The objective of this study was to develop and validate a sensitive and specific ELISA for the determination of anti-EPO Abs that would suit these purposes. In this new double antigen bridging ELISA, anti-EPO Abs bind via one site to recombinant human erythropoietin (rhEPO)-biotin immobilized to streptavidin-coated microtiter plates (MTPs) and by a second site to rhEPO labelled with digoxigenin (DIG). The amount of bound antibody is determined using an anti-DIG antibody coupled to peroxidase. A rabbit polyclonal anti-EPO Ab purified by immunoadsorption is used as reference antibody preparation. The dynamic range of this ELISA was 1-75 ng/ml per assay calibrated with the reference antibody preparation. The assay was specific for anti-EPO Abs and did not react with other immunoglobulins (Ig) present in human serum. The lower limit of detection (LLD) of the assay was 0.5 ng/ml, and the lower limit of quantitation (LLQ) was 1.0 ng/ml. Anti-EPO Abs could be detected in the sera of pure red cell aplasia (PRCA) patients. In contrast to previous reports, no anti-EPO Abs could be detected in the sera of patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS), or in the sera of dialysis patients.
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PMID:Development and evaluation of a new ELISA for the detection and quantification of antierythropoietin antibodies in human sera. 1560 20

Paracetamol (acetaminophen) is generally considered to be a weak inhibitor of the synthesis of prostaglandins (PGs). However, the in vivo effects of paracetamol are similar to those of the selective cyclooxygenase-2 (COX-2) inhibitors. Paracetamol also decreases PG concentrations in vivo, but, unlike the selective COX-2 inhibitors, paracetamol does not suppress the inflammation of rheumatoid arthritis. It does, however, decrease swelling after oral surgery in humans and suppresses inflammation in rats and mice. Paracetamol is a weak inhibitor of PG synthesis of COX-1 and COX-2 in broken cell systems, but, by contrast, therapeutic concentrations of paracetamol inhibit PG synthesis in intact cells in vitro when the levels of the substrate arachidonic acid are low (less than about 5 mumol/L). When the levels of arachidonic acid are low, PGs are synthesized largely by COX-2 in cells that contain both COX-1 and COX-2. Thus, the apparent selectivity of paracetamol may be due to inhibition of COX-2-dependent pathways that are proceeding at low rates. This hypothesis is consistent with the similar pharmacological effects of paracetamol and the selective COX-2 inhibitors. COX-3, a splice variant of COX-1, has been suggested to be the site of action of paracetamol, but genomic and kinetic analysis indicates that this selective interaction is unlikely to be clinically relevant. There is considerable evidence that the analgesic effect of paracetamol is central and is due to activation of descending serotonergic pathways, but its primary site of action may still be inhibition of PG synthesis. The action of paracetamol at a molecular level is unclear but could be related to the production of reactive metabolites by the peroxidase function of COX-2, which could deplete glutathione, a cofactor of enzymes such as PGE synthase.
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PMID:Mechanism of action of paracetamol. 1566 92

The superior tarsus is a plate of tissue that stiffens the upper eyelid, gives it support and determines its form. The purpose of the present study was to relate the composition of its extracellular matrix to its function and to report regional differences that may influence the activity of its Meibomian glands. Fourteen methanol-fixed specimens were cryosectioned for immunohistochemistry and labelled with a panel of monoclonal antibodies against a wide range of collagens, glycosaminoglycans and proteoglycans. Labelling was detected with avidin-biotin-peroxidase. A further six specimens were formalin-fixed for routine histology. The tarsal plate immunolabelled strongly for types I, III and VI collagen and for aggrecan, versican, tenascin, cartilage oligomeric matrix protein (COMP) together with a variety of glycosaminoglycans (notably chondroitin 6 sulphate). A region of strong labelling for aggrecan, dermatan sulphate and chondroitin 6 sulphate immediately surrounded the Meibomian glands. The site of labelling corresponded to a layer of acellular and amorphous matrix seen histologically that we have termed the 'territorial matrix'. The results suggested that the tarsal plate is a specialized connective tissue that is neither purely fibrous nor cartilaginous, yet has an aggrecan content that probably contributes to its stiffness. Its unique character highlights the challenge in choosing an ideal mechanical substitute. As patients with rheumatoid arthritis often have problems relating to tear film deficiency, the ability of aggrecan or COMP to act as autoantigens may be significant. An immune reaction directed against these molecules could alter tarsal gland function by interfering with the interaction between the glands and their territorial matrix.
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PMID:An immunohistochemical study of the extracellular matrix of the tarsal plate in the upper eyelid in human beings. 1567 69

Human tumor necrosis factor alpha (hTNF-alpha) is one of the most important inflammatory cytokines that acts as a mediator in inflammatory and immune response and plays a key role in host defense against infection. The over expression of hTNF-alpha is associated with serious consequences, such as shock, hypotension, thrombus, septicemia and even death. It has been implicated in many autoimmune and inflammatory diseases, such as rheumatoid arthritis, Crohn's disease, chronic heart failure and septic shock. Inhibiting the bio-activity of hTNF-alpha is one of the strategy for the treatment of these diseases. Compared with traditional recombinant protein drugs, small molecule drugs have many advantages, such as high affinity, low immunogenecity and low cost. Systematic evolution of ligands by exponential enrichment (SELEX) is a powerful method for the selection of oligonucleotides that bind with high affinity and specificity to target proteins. Such oligonucleotides are called aptamers, and are potential therapeutics for blocking the activity of pathologically relevant proteins. To obtain oligonucleotide aptamers specifically binding to TNF, a 40nt random DNA combinatorial library flanked by 31nt fixed sequences was chemically synthesized. The random library was amplified with PCR and subjected to selection by SELEX protocol against hTNFalpha. After incubation of the library with hTNFalpha, the mixture was blotted onto Immobilon-NC transfer membrane. The no-specific binding was washed away and the hTNFa binding aptamers were eluted and detached from the target protein. The eluted oligo nucleotides were amplified with PCR and served as the DNA library for the next round selection. After 12 rounds of such selection, the selected aptamers were cloned to pGEM-T vector. Positive clones were identified by restriction enzyme digestion and DNA sequencing. Oligo DNA were synthesized according to the sequence data and tested for their activities. Binding activity of the aptamers to hTNFalpha were detected by ELISA and dot blot with biotin-streptavidin-horseradish peroxidase system. Mouse L929 cells were used to test the anti-hTNFa activity of the DNA aptamers. The aptamers were incubated with hTNFalpha and added to the L929 cells. The results were read under microscope and with MTT staining. It was shown that these DNA aptamers bound to hTNFalpha with high affinity, and can inhibit the cytotoxicity of hTNFalpha on cell culture. The affinity of these aptamers are different and may related to their structure. These ssDNA aptamers are potential for the treatment and diagnosis of hTNFalpha related diseases.
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PMID:[Screening and characterization of DNA aptamers with hTNF-alpha binding and neutralizing activity]. 1597 88


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