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ID PMID Title PublicationDate abstract
11269532 Differential in vitro effects of IL-4, IL-10, and IL-13 on proinflammatory cytokine produc 2001 Feb The purpose of this study was to compare the potential of interleukin-4 (IL-4), IL-10, and IL-13 to interrupt two major inflammatory pathways in rheumatoid arthritis (RA), i.e., overexpression of proinflammatory cytokines and cytokine-mediated fibroblast growth. IL-4, IL-10, and IL-13 were all able to significantly inhibit the production of IL-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 by freshly isolated RA synovial tissue cells, IL-10 was most effective in terms of IL-1beta and TNF-alpha reduction. The IL-1 receptor antagonist was enhanced by IL-4 and IL-13, but only slightly enhanced by IL-10. Spontaneous interferon-gamma secretion was diminished by IL-4 and IL-10 but not by IL-13. Addition of anti-IL-10 neutralizing antibody to RA synovial tissue cells resulted in a substantial increase in IL-1beta and TNF-alpha levels, whereas neither anti-IL-4 nor anti-IL-13 antibody had a significant effect. IL-1beta-stimulated proliferation of RA synovial fibroblast cell lines was inhibited by IL-4 and IL-13, but not by IL-10; IL-4 was over tenfold more effective than IL-13. These results suggest that IL-4, IL-10, and IL-13 all have the therapeutic potential to regulate the disease activity mediated by proinflammatory cytokines in RA, but each cytokine may have different potencies.
9418618 10- to 20-year followup of total knee arthroplasty for valgus deformities. 1997 Dec One hundred eight knees in 83 patients with a valgus alignment of greater than 10 degrees underwent total joint replacement performed by a single surgeon using the same technique for ligament balancing, which involved releasing the lateral retinaculum and iliotibial band, followed when necessary by detaching the lateral collateral ligament and popliteus tendon from the femur. Sixty knees in 46 patients had followup of at least 10 years and were the focus of study. At an average followup of 14.1 years, the mean Knee Society knee score was 88.7 and the mean functional score was 69.2. Postoperative knee alignment averaged 4.5 degrees with 75% of the knees corrected to between 2 degrees and 7 degrees valgus. Postoperative flexion averaged 101 degrees. There were no cases of peroneal nerve palsy or patellar dislocation. Six knees underwent revision surgery with two for sepsis, three for aseptic loosening, and one for a traumatic patella fracture. Radiographic component loosening also was seen in one knee. The probability of retention of the prosthesis was 91% (+/- 11.7%) at 13.2 years. Although the results in this group of patients seem acceptable, the rate of postoperative instability for all patients treated using this ligament balancing technique was 24%. Because of the high rate of instability, a new soft tissue release technique has been developed and is the preferred method for ligament balancing of the valgus knee during total knee arthroplasty.
10502016 [New aspects of treatment and prophylaxis of gastrointestinal side effects caused by non-s 1999 Aug Gastropathies caused by treatment with non-steroidal-antiinflammatory drugs (NSAIDs) are a frequent problem in rheumatology. An increased risk for this complication has been established for patients older than 70 years, for those with a history of ulcer and those under concomitant steroid medication. Especially those patients should be treated with gastroprotective drugs. In differing intensity, protone pump inhibitors, prostaglandine analog and H2 blockers are able to prevent such problems and give some symptomatic relief. Most complications can be prevented using omeprazole, the newest and most expensive drug, in a dosage of 20 mg/day, a higher dosage is not more effective. This drug works also in many cases when the NSAID therapy has to be continued. A significant effect on the prevalence of serious GI effects was only shown for misoprostol in a dosage of 800 microg/day to date. Some influence on the risk for GI events can also be taken by questioning the indication, choice of the NSAID and proper information of the patient. The development of COX-2-selective and even specific NSAIDs might solve some of these drug related GI problems in the near future.
10090188 Validity of area-under-the-curve analysis to summarize effect in rheumatoid arthritis clin 1999 Mar There is a continuing interest in increasing the statistical efficiency of the analysis of clinically meaningful endpoints in rheumatology. One issue that is attracting increasing attention is whether the conventional practice of only reporting the outcome at the end of the study (EOS) might be replaced or complemented by a longitudinal summary that better reflects the clinical course of the disease. The area under the curve (AUC) is a summary measure that integrates serial assessments of a patient's endpoint over the duration of the study. We evaluated the utility of AUC as a summary measure for the analysis and reporting of two RA trials: (i) methotrexate combined with cyclosporine versus methotrexate and placebo in partial methotrexate responders in relatively late disease, and (ii) prednisone plus methotrexate plus sulfasalazine versus sulfasalazine alone in relatively early disease. We replicated the published results of each trial first using the conventional EOS and then AUC summaries. For each patient, the changes from baseline over time were transformed into a summary measure by calculating AUC using the trapezium rule and then standardizing it by the study duration. Using an approach similar to the index of responsiveness to change, we scaled treatment differences derived from EOS and AUC summary measures by their standard deviation of the control group. This signal-versus-noise ratio captures the treatment discrimination ability of each summary measure. Compared to EOS and within each treatment group, the AUC summary reported smaller effects (i.e., change from baseline) with reduced errors in the estimates. AUC measures preserved discriminant validity in treatment comparisons and reported smaller but more precise treatment effect estimates. In the COBRA trial with rapidly-acting medications, AUC seemed to be more sensitive than EOS to detect treatment difference. With slow acting medications and in relatively late disease patients as in the cyclosporine trial, EOS was more sensitive to detect treatment difference than was AUC. In this setting, AUC, however, still seemed to be more sensitive than EOS for the two responsive-to-change endpoints: tender joint counts and pain by visual analog scale. AUC integrates repeated assessments during the trial duration into summary measures. Compared to EOS, the report of RA trial results using AUC summary provides smaller estimates of treatment effects but with better precision. AUC summary is likely to preserve treatment group discrimination taking into account the appropriate onset and offset of the drug action. Trial reports using AUC summary have smaller effect sizes. For trials with long acting medications and short duration similar to the cyclosporine trial, AUC still preserves treatment discrimination but may not be as sensitive as EOS. The calculations of AUC require some additional work in the analysis of each endpoint.
10598013 The molecular mechanism of inhibition of interleukin-1beta-induced cyclooxygenase-2 expres 1999 Nov OBJECTIVE: Several extracts of Tripterygium wilfordii Hook F (TWHF) have been reported to be effective in patients with rheumatoid arthritis. We investigated the effect of multi-glycosides ofTWHF (GTW), a TWHF extract, on interleukin (IL)-1beta stimulated human rheumatoid synovial cells. MATERIALS AND METHODS: IL-1beta-stimulated synovial cells were used to detect the effects of GTW on cyclooxygenase (COX)-1 and COX-2 activities, expression of COX protein and mRNA, and nuclear transcription factors in experiments using respective reporter plasmids. RESULTS: GTW inhibited prostaglandin E2 production by IL-1beta-stimulated synovial cells in a concentration-dependent manner, and also inhibited COX-2 protein and mRNA expression in a similar fashion to dexamethasone. However, GTW did not act as a glucocorticoid agonist. GTW repressed IL-1beta-induced nuclear factor-kappaB activity, but did not have a significant influence on activating protein-1 activity. CONCLUSION: The anti-rheumatic effect of GTW or TWHF may be partly mediated through the inhibition of prostaglandin E2 production in human synovial cells due to suppression of COX-2 mRNA, possibly via inhibition of nuclear factor-kappaB activity.
11147786 Suggestive evidence for association of human chromosome 18q12-q21 and its orthologue on ra 2001 Jan Some immune system disorders, such as type 1 diabetes, multiple sclerosis (MS), and rheumatoid arthritis (RA), share common features: the presence of autoantibodies and self-reactive T-cells, and a genetic association with the major histocompatibility complex. We have previously published evidence, from 1,708 families, for linkage and association of a haplotype of three markers in the D18S487 region of chromosome 18q21 with type 1 diabetes. Here, the three markers were typed in an independent set of 627 families and, although there was evidence for linkage (maximum logarithm of odds score [MLS] = 1.2; P = 0.02), no association was detected. Further linkage analysis revealed suggestive evidence for linkage of chromosome 18q21 to type 1 diabetes in 882 multiplex families (MLS = 2.2; lambdas = 1.2; P = 0.001), and by meta-analysis the orthologous region (also on chromosome 18) is linked to diabetes in rodents (P = 9 x 10(-4)). By meta-analysis, both human chromosome 18q12-q21 and the rodent orthologous region show positive evidence for linkage to an autoimmune phenotype (P = 0.004 and 2 x 10(-8), respectively, empirical P = 0.01 and 2 x 10(-4), respectively). In the diabetes-linked region of chromosome 18q12-q21, a candidate gene, deleted in colorectal carcinoma (DCC), was tested for association with human autoimmunity in 3,380 families with type 1 diabetes, MS, and RA. A haplotype ("2-10") of two newly characterized microsatellite markers within DCC showed evidence for association with autoimmunity (P = 5 x 10(-6)). Collectively, these data suggest that a locus (or loci) exists on human chromosome 18q12-q21 that influences multiple autoimmune diseases and that this association might be conserved between species.
11465721 Chromosomal DNA from a variety of bacterial species is present in synovial tissue from pat 2001 Jul OBJECTIVE: We and others have reported the presence of Chlamydia and other bacterial species in joint specimens from patients with reactive arthritis (ReA). The present study was conducted to investigate whether bacteria other than those specified by diagnostic criteria for ReA could be identified in synovial fluid (SF) or tissue from patients with various arthritides, and whether the presence of such organisms corresponds to particular clinical characteristics in any patient set or subset. METHODS: DNA in synovial biopsy samples and SF obtained from 237 patients with various arthritides, including ReA, rheumatoid arthritis, and undifferentiated oligoarthritis, was assayed by polymerase chain reaction (PCR) using "panbacterial" primers; we chose only samples known to be PCR negative for Chlamydia, Borrelia, and Mycoplasma species. PCR products were cloned, and cloned amplicons from each sample were sequenced; DNA sequences were compared against all others in GenBank for identification of bacterial species involved. RESULTS: Ten percent of patient samples were PCR positive in panbacterial screening assays. Bacterial species identified belonged to the genera Neisseria, Acinetobacter, Moraxella, Salmonella, Pseudomonas, and others. Thirty-five percent of PCR-positive patients showed the presence of DNA from more than a single bacterial species in synovium; overall, however, we could identify no clear relationship between specific single or multiple bacterial species in the synovium and any general clinical characteristics of any individual or group of patients. CONCLUSION: This analysis provides the first systematic attempt to relate bacterial nucleic acids in the synovium to clinical characteristics, joint findings, and outcomes. Many patients with arthritis have bacterial DNA in the joint, and, in some cases, DNA from more than a single species is present. However, except for 1 case of a control patient with staphylococcal septic arthritis, it is not clear from the present study whether the synovial presence of such organisms is related to disease pathogenesis or evolution in any or all cases.
11587283 COX-2 inhibition and thrombotic tendency: a need for surveillance. 2001 Aug 20 Cyclooxygenase-2 (COX-2) inhibitors belong to a new class of drugs which have anti-inflammatory efficacy similar to that of traditional non-steroidal anti-inflammatory drugs (NSAIDs), but are associated with a reduced incidence of adverse upper gastrointestinal events. Biochemical evidence that COX-2 inhibitors could promote or exacerbate a tendency to thrombosis is supported by recent results from clinical trials and case reports. Two agents in this class, celecoxib and rofecoxib, have been listed on the Pharmaceutical Benefits Scheme (PBS) for very broad indications in chronic arthropathies, suggesting that they will move into widespread community use. It is important to canvass the possibility that use of these agents could be associated with thrombotic events.
10073167 [Tiopronin-induced nephrotic syndrome with minimal glomerular lesions]. 1999 Feb 13 BACKGROUND: In the very large majority of cases, nephrotic syndrome with minimal glomerular lesions is an idiopathic condition. Drugs can favor the glomerulopathy. The effect of non-steroidal antiinflammatory drugs is well known, but other drugs, particularly tiopronin may be incriminated. CASE REPORT: A 73-year-old patient developed severe nephrotic syndrome with minimal glomerular lesions 6 weeks after tiopronin therapy was initiated. Complete and spontaneous remission of the nephrotic syndrome was achieved 5 weeks after drug withdrawal. No recurrent lipoidic nephrosis has been observed at 3 years follow-up. CONCLUSION: Tiopronin-induced nephrotic syndrome with minimal glomerular lesions is usually severe and develops rapidly. Remission occurs rapidly after drug withdrawal. Weekly urine checks with dip-strips should be proposed in patients treated with tiopronin.
10618411 Use of soluble peptide-DR4 tetramers to detect synovial T cells specific for cartilage ant 2000 Jan 4 Considerable evidence indicates that CD4(+) T cells are important in the pathogenesis of rheumatoid arthritis (RA), but the antigens recognized by these T cells in the joints of patients remain unclear. Previous studies have suggested that type II collagen (CII) and human cartilage gp39 (HCgp39) are among the most likely synovial antigens to be involved in T cell stimulation in RA. Furthermore, experiments have defined dominant peptide determinants of these antigens when presented by HLA-DR4, the most important RA-associated HLA type. We used fluorescent, soluble peptide-DR4 complexes (tetramers) to detect synovial CD4(+) T cells reactive with CII and HCgp39 in DR4(+) patients. The CII-DR4 complex bound in a specific manner to CII peptide-reactive T cell hybridomas, but did not stain a detectable fraction of synovial CD4(+) cells. A background percentage of positive cells (<0.2%) was not greater in DR4 (DRB1*0401) patients compared with those without this disease-associated allele. Similar results were obtained with the gp39-DR4 complex for nearly all RA patients. In a small subset of DR4(+) patients, however, the percentage of synovial CD4(+) cells binding this complex was above background and could not be attributed to nonspecific binding. These studies demonstrate the potential for peptide-MHC class II tetramers to be used to track antigen-specific T cells in human autoimmune diseases. Together, the results also suggest that the major oligoclonal CD4(+) T cell expansions present in RA joints are not specific for the dominant CII and HCgp39 determinants.
9338911 Continuous parasacral sciatic nerve block: two case reports. 1997 Sep OBJECTIVE: This study investigated the use of a continuous parasacral sciatic nerve block for anesthesia and postoperative analgesia for lower extremity surgery. METHODS: A continuous parasacral sciatic nerve block was performed in two patients (triple ankle arthrodesis and below-knee amputation). The sacral plexus was identified using an insulated Tuohy needle and a nerve stimulator. A catheter was placed near the elements of the sacral plexus via the Tuohy needle. RESULTS: In both patients, surgical anesthesia was successfully established through the parasacral catheter with lidocaine 1% (1/200,000 epinephrine), and postoperative analgesia was successfully established with a bolus of bupivacaine 0.375% (1/200,000 epinephrine) and maintained with a continuous infusion of bupivacaine 0.1% (8 mL/h) for 48 hours. CONCLUSION: We conclude that continuous parasacral sciatic nerve block can provide anesthesia and long-term analgesia for operative procedures of the foot and leg.
9796911 Modulation of HLA-DQ-restricted collagen-induced arthritis by HLA-DRB1 polymorphism. 1998 Oct Mouse class II-deficient HLA-DQB1*0302, DQA1*0301 (DQ8) transgenic mice are susceptible to severe collagen-induced arthritis (CIA), an animal model for rheumatoid arthritis. To examine whether polymorphism at the DRB1 locus can modulate DQ-restricted arthritis, we generated double-transgenic (DR/DQ) mice. HLA-DRB1*1502 (DR2) and DRB1*0301 (DR3) were introduced separately into CIA susceptible DQ8.Abeta transgenic mice to generate DQ8/DR2.Abeta and DQ8/ DR3.AbetaO mice. The HLA-DR molecules in these mice were found to be functional on the basis of their positive/negative selection of the Vbeta T cell repertoire. Introduction of the DR2 gene led to a significant decrease in disease incidence in DQ8.Abeta mice, while the DR3 transgene had no effect. In vitro T cell proliferative responses against bovine Cll collagen in primed mice were higher in DQ8/DR3 mice compared with DQ8/DR2 mice. Cytokine analysis showed a Th2 profile in DQ8/DR2 mice, while DQ8/DR3 mice showed a Th1 profile. These results suggest that DRB1 polymorphism can modulate the disease.
10211883 Autoantibodies in primary Sjögren's syndrome are directed against proteasomal subunits of 1999 Apr OBJECTIVE: The proteasome subunit HC9 (alpha3) has recently been identified as a major target of the humoral autoimmune response in patients with autoimmune myositis and systemic lupus erythematosus. Since B cell hyperreactivity is a common feature of systemic autoimmune diseases, patients with primary Sjögren's syndrome (SS) and other control groups were investigated to evaluate the significance of autoantibodies against the proteasome. METHODS: Analyses of autoantibodies directed against the 20S proteasome were performed using enzyme-linked immunosorbent assay, immunoblot, and 2-dimensional electrophoresis. Forty-three patients with primary SS, 47 patients with rheumatoid arthritis including 9 with secondary SS, 19 patients with gastrointestinal tumors, and 80 healthy controls were tested for antiproteasome antibodies. RESULTS: Antiproteasome antibodies were detected in 39% of patients (17 of 43) with primary SS. In contrast, only 1 of 47 patients with rheumatoid arthritis showed positive reactivity (P < 0.001). Serum samples from 19 tumor patients (P < 0.003) and 80 healthy controls (P < 0.001) were serologically negative. Moreover, immunoblotting and 2-dimensional analysis of the antiproteasome response revealed a polyspecific recognition pattern in 7 patients with primary SS. Different proteasomal subunits of the alpha and beta type, including subunits that carried the proteolytic active sites, were recognized by the patients' sera. CONCLUSION: The humoral antiproteasome response in primary SS, in contrast to its secondary form, is characterized by an extensive recognition pattern of several subunits, indicating a polyspecific B cell activation against the 20S proteasome. Moreover, proteolytically active beta-type subunits, which are important for the generation of major histocompatibility complex class I-restricted antigens, appear to be targets of the autoimmune response. The data indicate that the proteasome itself may stand on a cross point of pathways that links mechanisms of the immune defense with features of systemic autoimmunity.
9553548 4- to 10-year results with the anatomic modular total knee. 1998 Mar The outcome of 186 consecutive total knee arthroplasties performed with the Anatomic Modular Knee is reported. One hundred forty-two knees had followup of 4 to 10 years (mean, 6.9 years). Two knees required revision of all components, one because of infection and the other for instability. Seven patients underwent exchange of the modular tibial polyethylene insert at an average of 84 months postoperatively. The mean age of these seven patients at primary arthroplasty was 54 years. No implant showed clinical or radiographic evidence of loosening and there were no complications related to patellofemoral articulation. The revision rate of the femoral, tibial, and patellar components was two of 142 or 1.4%. The revision rate including exchange of the polyethylene insert was nine of 142 or 6.3%. This minimally constrained posterior cruciate retaining modular design performed well at intermediate followup. The absence of patellofemoral complications and aseptic loosening was notable. Wear related phenomena were the most common indications for reoperation and these occurred in younger, active individuals with relatively thin polyethylene bearings. The relative value of modular tibial inserts and the outcome of isolated polyethylene exchanges warrant additional study.
10806050 Increased serum levels of non-collagenous matrix proteins (cartilage oligomeric matrix pro 2000 May OBJECTIVE: Marathon runners have an increased risk of developing joint disease. During and after a 42-km run, elevation of multiple cytokines occurs in the blood, reflecting inflammatory processes. We compared this cytokine response with serum levels of cartilage oligomeric matrix protein (COMP) and melanoma inhibitory activity (MIA), two markers for joint metabolism and/or damage. METHODS: Serum from eight endurance-trained runners was collected shortly before the start of a marathon run, after 31 km, 42 km, 2 h after the end, on the first and on the second morning after the run. For comparison, serum was obtained from 35 healthy controls and 80 patients with knee joint injury, rheumatoid arthritis or osteoarthritis. Serum levels of C-reactive protein (CRP), interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1RA), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble interleukin-6 receptor (sIL-6R, gp80), soluble tumor necrosis factor receptor II (sTNFRII, p75), COMP and MIA were measured by ELISA. RESULTS: Compared with healthy controls, the runner's baseline serum levels of TNF-alpha, sIL-6R, COMP and MIA were significantly increased. COMP and MIA levels, higher than the upper normal limits of 5 microg/ml and 6 ng/ml respectively, were found in seven and five of eight runners. The elevated levels of COMP were similar to those found in joint injury or osteoarthritis, and the elevated levels of MIA were comparable to those reported in rheumatoid arthritis. During the run, the serum levels of IL-1RA, IL-6, TNF-alpha and COMP rose significantly, and gradually returned to baseline within 24 h. Only modest changes of CRP, sIL-6R, sTNFRII and MIA occurred during the run. Late elevations of CRP and MIA were observed after 24 and 48 h. The correlation analysis suggests associations between COMP, sIL-6R, TNF-alpha, IL-1RA on one hand and sTNFRII, and MIA and CRP on the other hand. CONCLUSIONS: Elevated baseline levels of COMP and MIA might reflect increased joint matrix turnover and/or damage due to prior extreme physical training. During the run, COMP was increasing possibly due to the severe physical strain on joint structures, associated with the early inflammation. After the run, MIA and CRP increased within 24 h, suggesting a correlation with later inflammatory processes. Thus, our data suggest that COMP and MIA are markers for distinct aspects of joint metabolism and/or damage in both disease and sport.
11145280 Selective inhibitors of COX-2--are they safe for the stomach? 2000 Nov NSAIDs are widely used and beneficial for patients with inflammatory pain. However, NSAIDs cause significant adverse upper gastrointestinal effects, including increased mortality from serious ulcer complications. NSAIDs exert their anti-inflammatory effects by inhibiting the activity of the COX enzyme, which was recently shown to exist in two isoforms, a constitutive COX-1 and an inducible COX-2. The latter isoform is induced in inflammation, while the former is responsible for prostaglandin effects on platelet function and gastric mucosal defense. Two specific COX-2 inhibitors have recently been introduced into the market. The available data from clinical trials indicate that these new drugs have anti-inflammatory and analgesic effects similar to those of conventional NSAIDs, but reduced rates of adverse upper gastroduodenal effects, which are similar to those observed with placebo. This difference in rates of adverse effects might imply improved safety for patients requiring anti-inflammatory treatment. It has, however, to be kept in mind that specific COX-2 inhibitors lack cardiovascular protective effects. Considering the high consumption rate of NSAIDs to achieve pain relief in arthritis and other musculo-sceletal diseases, the reduced risk of gastrointestinal ulcers and ulcer complications may have a positive impact on population health and health economy.
11317164 The hepatic safety and tolerability of the novel cyclooxygenase-2 inhibitor celecoxib. 2000 May Celecoxib is a cyclooxygenase- (COX)-1-sparing inhibitor of COX-2 that is indicated for the treatment of osteoarthritis and rheumatoid arthritis. Many agents used for treating these diseases, both symptom-modifying and disease-modifying, are associated with the potential for hepatotoxicity. This article presents an analysis of the hepatic effects of celecoxib in 14 controlled studies of patients with arthritis (2 to 24 weeks' duration), in a long-term, open-label safety study (as long as 2 years), in 11 studies of patients receiving treatment for pain after oral or orthopedic surgery (up to 5 days' duration), and in five pharmacology studies. The overall incidence of hepatic adverse events in arthritis patients receiving celecoxib was similar to that for placebo but significantly lower than in the combined group of patients receiving nonsteroidal anti-inflammatory drugs (NSAIDs). The most commonly reported hepatic adverse events were elevations in liver transaminase levels, most of which occurred in patients receiving diclofenac. Similarly, clinically significant elevations of transaminase levels occurred more frequently with NSAIDs than with celecoxib. A pharmacology study performed in patients with mild or moderate hepatic impairment showed that celecoxib did not produce any clinically relevant changes from baseline in creatinine clearance, alanine aminotransferase, or bilirubin values in these settings. In the four interaction studies performed with drugs metabolized in the liver, none of the adverse events was hepatic in nature, and no clinically relevant liver function test abnormalities occurred. In conclusion, this analysis suggests that celecoxib has a very low potential for hepatic toxicity, even after exposures of as long as 2 years at therapeutic doses.
11822784 Activated Ras modifies the proliferative response of rheumatoid synovial cells to TNF-alph 2001 Dec OBJECTIVE: To study the role of the Ras/mitogen-activated protein kinase (MAPK) pathway in the proliferative response of rheumatoid synovial fibroblast (RSF) to tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-alpha. METHODS: V-Ki-ras gene was introduced into RSF using a retrovirus and the proliferative response of these cells to TNF-alpha or TGF-alpha was estimated by measuring the uptake of 3H-thymidine. The effect of a mitogen-activated protein kinase kinase (MEK) inhibitor, PD98059, was also investigated. RESULTS: Consistent with previous reports, TNF-alpha and TGF-alpha stimulated the proliferation of RSF. When the v-Ki-ras gene was expressed, the basal growth rate of these cells was increased, but their growth was suppressed by TNF-alpha or TGF-alpha. The latter effect was abolished when the cells were exposed to a relatively low concentration of PD98059. CONCLUSION: Ras modulates the proliferative response of RSF to TNF-alpha and TGF-alpha.
11229477 Increased production of intracellular interleukin-1 receptor antagonist type I in the syno 2001 Feb OBJECTIVE: To examine the patterns of production of interleukin-1 receptor antagonist (IL-1Ra) isoforms and of IL-1beta during arthritis in vivo. METHODS: Arthritis was induced in DBA/1 mice by immunization with type II collagen, and the production of IL-1Ra isoforms was examined in whole joints and in dissected synovial tissues by reverse transcription-polymerase chain reaction (RT-PCR), RNase protection assay, Western blotting, immunostaining, and in situ hybridization. Production of IL-1beta also was examined using similar approaches. RESULTS: Production of IL-1Ra increased in the joints during collagen-induced arthritis (CIA). By RT-PCR, secreted IL-1Ra messenger RNA (mRNA) was detected in normal joints, whereas intracellular IL-1Ra type I (icIL-1Ra1) mRNA was only produced in inflamed joints. Western blot studies showed that icIL-1Ra1 protein levels increased in the joints during the course of CIA and that icIL-1Ra3 protein was also present in low amounts. RNase protection assays showed that the IL-1beta:IL-1Ra mRNA ratio was increased in inflamed joints through day 14 of arthritis, whereas a reverse pattern was present at later time points (from day 20 to day 60). Consistent with this finding, immunohistochemistry and in situ hybridization studies confirmed that icIL-1Ra1 was only present in inflamed joints. The histologic evaluation of CIA during the course of the disease indicated a resolution of acute inflammation, since icIL-1Ra1 production increased and the ratio of IL-1beta to total IL-1Ra decreased. CONCLUSION: Production of IL-1Ra isoforms, particularly icIL-1Ra1, is stimulated in inflamed joints during CIA in mice. The combination of decreased production of IL-1beta and elevated levels of icIL-1Ra1 during the course of CIA was associated with a reduction in inflammatory activity. These results suggest that icIL-1Ra1 may play a role in the resolution of murine CIA.
9870871 Inhibition of interleukin-1alpha-induced cartilage oligomeric matrix protein degradation i 1998 Dec OBJECTIVE: To determine whether matrix metalloproteinases (MMPs) degrade cartilage oligomeric matrix protein (COMP) to produce fragments similar to those found in synovial fluid (SF) from patients with arthritis. METHODS: COMP fragments were generated in vitro by treating (a) bovine articular cartilage with interleukin-1alpha (IL-1alpha), (b) purified bovine COMP with MMPs, and (c) articular cartilage with MMPs. The fragments generated in each case were analyzed by Western blot, using an antibody to the C-terminal heptadecapeptide of COMP. RESULTS: IL-1alpha stimulation of cartilage resulted in a fragmentation of COMP, which was inhibited by MMP inhibitors CGS 27023A and BB-94. Isolated, recombinant MMPs rapidly degraded purified COMP, as well as COMP residing in cartilage. Several COMP fragments produced in vitro had similar electrophoretic mobility to those in SF of patients with arthritis. CONCLUSION: MMPs may contribute to the COMP fragments found in vivo. Quantitation of MMP-specific fragments may be useful in the evaluation of MMP inhibitors in patients with arthritis.