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ID PMID Title PublicationDate abstract
8460853 Factors associated with appendicular bone mass in older women. The Study of Osteoporotic F 1993 May 1 OBJECTIVE: To determine the factors associated with appendicular bone mass in older women. DESIGN: Cross-sectional analysis of baseline data collected for a multicenter, prospective study of osteoporotic fractures. SETTING: Four clinical centers in Baltimore, Maryland; Minneapolis, Minnesota; Portland, Oregon; and the Monongahela valley, Pennsylvania. PATIENTS: A total of 9704 ambulatory, nonblack women, ages 65 years or older, recruited from population-based listings. MEASUREMENTS: Demographic and historical information and anthropometric measurements were obtained from a baseline questionnaire, interview, and examination. Single-photon absorptiometry scans were obtained at three sites: the distal radius, midradius, and calcaneus. Multivariate associations with bone mass were first examined in a randomly selected half of the cohort (training group) and were then tested on the other half of the cohort (validation group). RESULTS: In order of decreasing strength of association, estrogen use, non-insulin-dependent diabetes, thiazide use, increased weight, greater muscle strength, later age at menopause, and greater height were independently associated with higher bone mass. Gastric surgery, age, history of maternal fracture, smoking, and caffeine intake were associated with lower bone mass (all P < 0.05). For example, we found that 2 or more years of estrogen use was associated with a 7.2% increase in distal radius bone mass, whereas gastrectomy was associated with an 8.2% decrease in bone mass. The associations between bone mass and dietary calcium intake and rheumatoid arthritis were inconsistent. Alcohol use, physical activity, use of calcium supplements, pregnancy, breast-feeding, parental nationality, and hair color were among the many variables not associated with bone mass. Multivariate models accounted for 20% to 35% of the total variance of bone mass. CONCLUSIONS: A large number of factors influence the bone mass of elderly women; however, age, weight, muscle strength, and estrogen use are the most important factors.
8854850 Visualization of the thymus by substance P receptor scintigraphy in man. 1996 Nov Substance P, an 11-amino acid neuropeptide, has an important role in modulating pain transmission through neurokinin 1 and 2 receptors. Substance P and other tachykinins may also play a role in the pathogenesis of inflammatory diseases. In this study we present the results concerning the metabolism of the substance P analogue [111In-DTPA-Arg1]-substance P in man, as well as the visualization of the thymus in patients with immune-mediated diseases. Twelve selected patients were investigated, comprising five with inflammatory bowel disease, one with ophthalmic Graves' disease, one with sclerosing cholangitis, one with Sjögren's syndrome, one with rheumatoid arthritis, one with systemic lupus erythematosus and two with myasthenia gravis. During and after intravenous administration of 150-250 MBq (2.5-5.0 microg) [111In-DTPA-Arg1]-substance P, blood pressure, heart rate and oxygen saturation were monitored. Radioactivity was measured in blood, urine and faeces during the 48 h after injection. Planar and single-photon emission tomographic images were obtained 4 and 24 h after injection. After administration of [111In-DTPA-Arg1]-substance P, a transient flush was observed in all patients. Degradation of [111In-DTPA-Arg1]-substance P started in the first minutes after administration, resulting in a half-life of 10 min for the total plasma radioactivity, and of 4 min for the intact radiopharmaceutical, as identified with high-performance liquid chromatography. Urinary excretion accounted for >95% of the radioactivity within 24 h post injection, and up to 0.05% was found in the faeces up to 60 h. In all patients uptake of radioactivity was found in the areolae mammae (in women), liver, spleen, kidneys and urinary bladder. In eight patients a high uptake of [111In-DTPA-Arg1]-substance P was observed in the thymus. We conclude that, despite its short half-life, [111In-DTPA-Arg1]-substance P, a new radiopharmaceutical, can be used to visualize the thymus. This may contribute to the investigation of the role of thymus in immune-mediated diseases. In addition, inflammatory sites in various diseases could be visualized.
8788993 Use of recombinant antigens of Borrelia burgdorferi in serologic tests for diagnosis of ly 1996 Feb Recombinant antigens of outer surface proteins (Osps) OspA, OspB, OspC, OspE, and OspF of Borrelia burgdorferi sensu stricto and of p41-G, an antigenic region of flagellin of this spirochete, were tested with human sera in class-specific and polyvalent enzyme-linked immunosorbent assays (ELISAs). In analyses for immunoglobulin M (IgM) antibodies, 18 (85.7%) of 21 serum samples from persons who had been diagnosed as having Lyme borreliosis on the basis of the presence of erythema migrans reacted positively in ELISAs with one or more Osp antigens or the p41-G antigen. Eleven serum samples contained antibodies to OspC antigen, and of these, six also reacted to the p41-G antigen and to one or more of the other recombinant antigens. The remaining five serum samples reacted solely to OspC (n = 4) or to OspC plus OspA and OspE without reactivity to p41-G (n = 1). In analyses for IgG antibodies, seropositivity was comparable to that of IgM analyses and was marked by predominant reactivity to p41-G, OspC, and OspF. Similarly, all 21 serum samples were positive in polyvalent and class-specific ELISAs with whole-cell B. burgdorferi. Minor cross-reactivity was noted when sera from persons who had syphilis, periodontitis or other oral infections, or rheumatoid arthritis were tested with OspC, OspE, OspF, and p41-G. With relatively high degrees of specificity, ELISAs with recombinant antigens, particularly OspC and p41-G, can help to confirm B. burgdorferi infections.
8719445 Mechanism of the antiproliferative action of leflunomide. A77 1726, the active metabolite 1995 Nov BACKGROUND: Leflunomide, a novel immunosuppressive drug, prolongs experimental graft survival effectively and has been well tolerated in patients with rheumatoid arthritis. A77 1726, the active metabolite of leflunomide, inhibits lymphocyte proliferation in vitro. This study was conducted in Jurkat T cells to investigate the effects of A77 1726 on signal transduction pathways initiated by ligands of the T-cell receptor CD3 complex and to evaluate the effects of A77 1726 on nucleotide biosynthesis. METHODS: Tritiated thymidine incorporation and cell counts quantitated cell proliferation. Spectrofluorescence of Indo/AM dye measured intracellular Ca2+ mobilization. A luciferase assay quantitated interleukin-2 gene promoter activity in stimulated cells transfected with an interleukin-2 promoter-luciferase gene construct. Pyrimidine and purine nucleosides were used to assess antagonism of the antiproliferative activity of A77 1726. RESULTS: (1) A77 1726 dose-dependently inhibited the proliferation of Jurkat T cells (inhibitory concentration of 50% = 6 mumol/L); (2) A77 1726 did not decrease mobilization of intracellular Ca2+ stimulated by phytohemagglutinin or anti-CD3 monoclonal antibody; (3) A77 1726 did not inhibit interleukin-2 gene promoter activity in cells stimulated with ionomycin plus phorbol myristate acetate; (4) inhibition of cell proliferation by A77 1726 was antagonized by addition of uridine, cytidine, or 2(+)-deoxycytidine; (5) addition of uridine 24 hours after treatment with A77 1726 antagonized inhibition of proliferation; (6) A77 1726 was not antagonized by 2'-deoxyuridine, thymidine, adenosine, or guanosine. CONCLUSIONS: (1) A77 1726 inhibited Jurkat T-cell proliferation without inhibiting T-cell receptor-mediated signal transduction events, including tyrosine kinase-dependent intracellular Ca2+ mobilization and activation of the interleukin-2 gene promoter; (2) the antiproliferative effects of A77 1726 on Jurkat T cells are primarily due to interruption of de novo pyrimidine nucleotide biosynthesis. These data provide evidence for a novel in vitro mechanism of the antiproliferative action of this immunosuppressant.
7962336 Bispecific thyroglobulin and thyroperoxidase autoantibodies in patients with various thyro 1994 Nov Recent evidence indicates that thyroid autoimmune disorders are associated with the presence of circulating autoantibodies (aAb) with dual specificity for thyroglobulin (TG) and thyroperoxidase (TPO). The question of whether these aAb, called TGPO aAb, are of clinical relevance compared to TG and TPO aAb remains to be determined. The availability of purified preparations of human TG and TPO allowed the development of a specific and sensitive RIA for TGPO aAb in serum. In the present study, we compared levels of aAb that cross-react with both TG and TPO (TGPO aAb) and total TG and TPO aAb levels, respectively, in sera from 84 normal controls and 226 patients with various thyroid and autoimmune diseases, including nontoxic goiter (n = 50), toxic nodular goiter (n = 13), thyroid carcinoma (n = 20), primary idiopathic myxedema (n = 15), postpartum thyroiditis (n = 11), Hashimoto's thyroiditis (n = 38), pernicious anemia (n = 27), rheumatoid arthritis (n = 19), and insulin-dependent diabetes mellitus (n = 33). In addition, 16 patients with Hashimoto's thyroiditis were studied before therapy and after more than 3 months of treatment with L-T4. It was shown that TGPO aAb were generally, but not always, present in the serum of patients with Hashimoto's thyroiditis, which also contained TG and TPO aAb. In contrast, TGPO aAb were undetectable in normal controls (excepting a few cases reaching borderline levels) as well as in sera from the majority of the other patients tested. Selecting sera positive for TGPO and either TG or TPO aAb, a statistically significant correlation was found between TGPO and TG (n = 26; P < 0.005), but not TPO aAb. Interestingly, the TGPO aAb level significantly decreased in patients with Hashimoto's thyroiditis after hormonal therapy (P < 0.05), some of them shifting from TGPO aAb positive before treatment to negative after treatment. In conclusion, TGPO aAb determination distinguishes Hashimoto's patients from patients with either thyroid and/or autoimmune diseases. The specific presence of TGPO aAb in a subset of Hashimoto's patients and their variation during T4 therapy remain to be understood. This could give a clue to mechanisms of autoimmune thyroid disease.
8419398 Differential induction of stromelysin mRNA by bovine articular chondrocytes treated with i 1993 Jan Articular chondrocytes from rheumatoid joints have been shown to express class II major histocompatibility (MHC) antigens that were correlated with the presence of interferon-gamma (IFN-gamma) in the inflamed joint. Chondrocytes expressing MHC antigens function as antigen presenting cells and thus stimulate lymphocyte proliferation. These responses suggest a powerful role for the IFN-gamma stimulation of chondrocytes. The present studies were designed to examine the functional role of chondrocytes exposed to IFN-gamma during cartilage degradation that occurs in synovial disease. Destruction of cartilage in arthritis is partially attributable to metalloproteinases released by the chondrocytes in response to interleukin-1 (IL-1). Bovine articular chondrocytes treated with interleukin-1 alpha (IL-1 alpha) produced enhanced levels of stromelysin mRNA, however, Northern blots could not determine the percentage of cells responding. Exposure of bovine articular chondrocytes to IFN-gamma induced the expression of bovine HLA-DR (boHLA-DR) antigen in 50% of the cells. Using a modified cell sorting technique, chondrocytes that expressed class II MHC antigens produced two fold greater stromelysin mRNA than chondrocytes that did not express this antigen. In contrast, collagen type II mRNA levels were similar in chondrocytes, regardless of the expression of class II MHC antigens. In situ hybridization studies showed that less than half of all cartilage chondrocytes were induced to synthesize stromelysin mRNA. These observations suggest that IFN-gamma stimulates specific subpopulations of chondrocytes to be functionally active in inflammation-induced metalloprotease secretion.
1295093 Laryngeal involvement in systemic lupus erythematosus. 1992 Dec Laryngeal involvement in systemic lupus erythematosus (SLE) can range from mild ulcerations, vocal cord paralysis, and edema to necrotizing vasculitis with airway obstruction. In this report, four cases showing the range of severity of this disease manifestation are presented, accompanied by a comprehensive review of the literature. The clinical course of 97 patients with laryngeal involvement with SLE are reviewed, of whom 28% had laryngeal edema and 11% had vocal cord paralysis. In the majority of cases, symptoms such as hoarseness, dyspnea, and vocal cord paralysis resolved with corticosteroid therapy. Other, less common causes of this entity included subglottic stenosis, rheumatoid nodules, inflammatory mass lesions, necrotizing vasculitis, and epiglottitis. The clinical presentation of laryngeal involvement in patients with SLE follows a highly variable course, ranging from an asymptomatic state to severe, life-threatening upper airway compromise. With its unpredictable course and multiple causations, this complication remains a diagnostic and therapeutic challenge to physicians involved in the care of patients with SLE.
8076835 Gene expression, purification and characterization of recombinant human neutrophil collage 1994 Sep 2 Human neutrophil collagenase (HNC) is a member of a family of matrix metalloproteinases (MMP). HNC is capable of cleaving all three alpha-chains of types I, II and III collagens. In rheumatoid and osteo-arthritis, MMP members have been implicated in the pathology associated with these diseases due to the accelerated breakdown of the extracellular matrix of articular cartilage. A cDNA coding for the HNC catalytic domain (lacking both the propeptide and C-terminal fragments) was sub-cloned into the pETlla prokaryotic expression vector. The cloned fragment encodes a protein that extends from amino acids (aa) Met100 through Gly262 of the full-length proenzyme, which as a result, would not require proteolytic or chemical activation. The HNC construct was expressed in Escherichia coli and recombinant mature, truncated neutrophil collagenase (re-mNC-t) was produced at high levels (approx. 30% of total bacterial protein). The re-mNC-t protein was extracted from inclusion bodies by solubilization in 6 M urea, followed by ion-exchange chromatography. The protein was refolded to an active conformation in the presence of Ca2+ and Zn2+. A final purification step on size-exclusion chromatography yielded 30 mg per liter of active re-mNC-t with minor autodegradative products. Alternatively, hydroxamate affinity chromatography was used to obtain pure, non-degraded re-mNC-t (20-25 mg per liter). The catalytic activity of re-mNC-t was abolished by known MMP inhibitors and the Ki measurement against actinonin was similar to that of HNC prepared from human blood.
9099930 Circulating antibodies against rat parotid gland M3 muscarinic receptors in primary Sjögr 1996 Jun In this study we demonstrate that IgG present in the sera of patients with primary Sjögren's syndrome (PSS) could bind and activate muscarinic acetylcholine receptors (mAChRs) of rat parotid gland. These antibodies were able to inhibit in a non-competitive manner the binding of 3H-quinuclidinyl benzilate (QNB) to mAChRs of purified rat parotid gland membranes. Moreover, IgG from PSS could modify biological effects mediated by mAChR activation; i.e. decrease cAMP, increase phosphoinositide turnover without affecting cGMP. Atropine and 4-DAMP blocked all of these effects, and carbachol mimicked them, confirming the M3 subtype mAChRs mediated PSS IgG action. Neither binding nor biological effect were obtained with IgG from sera of normal women. The prevalence of cholinergic antibody was 100% in PSS, and was independent of Ro/SS-A and La/SS-B antibodies. It could be concluded that antibody against mAChRs may be another serum factor to be considered in the pathophysiology of the development of PSS.
8325995 Histamine enhances interleukin (IL)-1-induced IL-1 gene expression and protein synthesis v 1993 Jul Histamine and IL-1 have been implicated in the pathogenesis of chronic inflammatory diseases, such as pulmonary allergic reactions and rheumatoid arthritis. We therefore investigated whether histamine modulated the synthesis of IL-1 beta. Human PBMC were stimulated with IL-1 alpha (10 ng/ml) in the absence or presence of histamine (10(-9)-10(-4) M). Histamine alone did not induce protein synthesis or mRNA accumulation for IL-1 beta. IL-1 alpha-induced IL-1 beta synthesis was enhanced two to threefold by histamine concentrations from 10(-6)-10(-4) M. Cimetidine, an H2 receptor antagonist, reversed the histamine (10(-5) M)-mediated increase in IL-1 alpha-induced IL-1 beta synthesis. Diphenhydramine, an H1 receptor antagonist, had no effect. Indomethacin, a cyclooxygenase inhibitor, significantly reduced IL-1 alpha-induced IL-1 beta synthesis, but had no effect on the histamine-mediated increase in IL-1 alpha-induced IL-1 beta synthesis. Histamine (10(-5) M) enhanced and sustained IL-1 beta mRNA levels in IL-1 alpha-stimulated PBMC. However, histamine reduced IL-1 beta mRNA half-life (2.4 vs 1.2 h), suggesting that histamine enhances IL-1 alpha-induced IL-1 beta synthesis at the level of transcriptional activation. On the other hand, histamine (10(-5) M) did not affect IL-1 alpha-induced synthesis of IL-1 receptor antagonist. These results suggest that mast cells may sustain chronic inflammatory processes by upregulating self-induction of IL-1 through histamine release.
8568267 TNF/IL-1-inducible protein TSG-6 potentiates plasmin inhibition by inter-alpha-inhibitor a 1996 Feb 15 TNF-stimulated gene 6 (tsg6), encoding a 35-kDa secretory glycoprotein (TSG-6), is induced in fibroblasts, chondrocytes, synovial cells, and mononuclear cells by the proinflammatory cytokines TNF-alpha and IL-1, or by LPS. Large amounts of TSG-6 protein were found in synovial fluids of patients with rheumatoid arthritis. TSG-6 protein forms a stable complex with components of the serine protease inhibitor, inter-alpha-inhibitor (I alpha I). In this work, we show that TSG-6 potentiates the inhibitory effect of l alpha l on the protease activity of plasmin. The plasmin/plasminogen activator system is important in the protease network associated with inflammation. To test the hypothesis that through their cooperative inhibitory effect on plasmin TSG-6 and l alpha l can modulate the protease network and thus inhibit inflammation, we examined the effect of TSG-6 on experimentally induced inflammation. Human recombinant TSG-6 protein showed a potent anti-inflammatory activity in the murine air pouch model of carrageenan- or IL-1-induced acute inflammation. The inhibitory effect of locally administered TSG-6 on the IL-1-induced cellular infiltration was comparable with that of systemic dexamethasone treatment. Two mutant TSG-6 proteins with single amino acid substitutions close to the N terminus showed a complete or partial loss of anti-inflammatory activity. The anti-inflammatory effect of the TNF/IL-1-inducible TSG-6 protein, along with its ability to inhibit protease action through interaction with l alpha l, suggests that TSG-6 production during inflammation is part of a negative feedback loop operating through the protease network.
8550744 Identification and characterization of insulin-like growth factors (IGFs), IGF-binding pro 1996 Jan The insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) in human synovial fluid play an important role in maintaining articular cartilage metabolism. In this study we measured the concentrations of IGF-I, IGF-II, and IGFBP-3 in normal human synovial fluid by RIA and characterized the IGFBPs by Western ligand blot (WLB), Western immunoblot, and immunoprecipitation. We also extended the study and compared normal synovial fluid to synovial fluids from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). The concentrations of IGF-I, IGF-II, and IGFBP-3 in normal synovial fluid were 19 +/- 3 (mean +/- SE), 194 +/- 14, and 349 +/- 65 ng/mL, respectively. In synovial fluid of patients with OA, IGF-I levels were elevated, whereas IGF-II was decreased, and the IGFBP-3 level was similar to the control value. In patients with RA, both IGF-I and IGFBP-3 were elevated, whereas IGF-II remained unchanged. WLB and immunoprecipitation of normal synovial fluid revealed IGFBP-1 (26-29 kDa), IGFBP-2 (32 kDa), IGFBP-3 (42- to 39-kDa doublet), and IGFBP-4 (24 kDa); the IGFBP-3 doublet was very faint. In RA synovial fluid, all IGFBPs were dramatically increased, whereas little change was seen in the synovial fluid of OA. Western immunoblot against IGFBP-3 revealed a prominent 30-kDa immunoreactive fragment of IGFBP-3 in synovial fluids of normal adults as well as in those of RA and OA patients. This was concurrent with detectable IGFBP-3 protease activity, which was characterized to be of the metallo- and serine protease family. Thus, in normal synovial fluid, there is a balance of circulating IGF, IGFBP, and proteases to modulate the bioactivity of IGF. In pathological states, the increased IGF-I concentrations were accompanied by an increase in IGFBP-I concentrations were accompanied by an increase in IGFBP-3 levels in synovial fluid. These findings suggest that alteration of the IGF and IGFBP axis in pathological states may be important for understanding the underlying pathophysiology of disordered articular growth and metabolism.
8548552 Prolonged systemic expression of human IL-1 receptor antagonist (hIL-1ra) in mice reconsti 1995 Nov This study was designed to test the feasibility and safety of long-term expression of high levels of secreted human interleukin-1 receptor antagonist (hIL-1ra) protein in mice by retroviral transduction of hematopoietic stem cells. The retroviral vector, CRIP-MFG-hIL-1ra (MFG-IRAP), carrying the hIL-1ra gene was used to infect mouse bone marrow (BM) which was subsequently injected into lethally irradiated mice. All of the mice survived and greater than 98% of the white blood cells (WBC) of these mice were of donor type from 2-13 months after transplantation. All of the mice had hIL-1ra protein in their sera (40-1200 ng of hIL-1ra/ml) at all assay periods for at least 15 months after transplantation. Bone marrow from seven of seven primary recipients produced at least one secondary recipient with sustained, high serum levels of hIL-1ra, indicating that hematopoietic stem cells had been successfully transduced. Although the hIL-1ra was biologically active when assayed in vitro, the mice appeared to be well and their WBC counts and hematocrit (HCT) were not significantly different from those of lethally-irradiated mice given BM cells infected with the same vector carrying the lacZ gene. There was also no evidence of alterations of white cell subpopulations. These results demonstrate that systemic production of biologically active hIL-1ra can be obtained by retrovirus-mediated gene transfer to hematopoietic stem cells and that this level of expression and secretion into the serum is compatible with normal BM engraftment, hematopoietic recovery and survival of the lethally irradiated recipient mice. These hIL-1ra-expressing mice represent a model to examine the functions of IL-1 and hIL-1ra and to determine the ability of hIL-1ra to reduce susceptibility to chronic diseases such as rheumatoid arthritis as well as effects of aging such as bone degeneration. The data further suggest that transduction and transplantation of hematopoietic stem cells is a potential method for delivery of hIL-1ra and other secreted therapeutic gene products for systemic diseases.
8625534 Human natural killer (NK) cells present staphylococcal enterotoxin B (SEB) to T lymphocyte 1996 May Superantigen-mediated T cell activation requires the participation of antigen-presenting cells (APC). Once superantigen has bound class II MHC molecules on the surface of APC, it then can interact with the T cell receptor to induce T cell activation. Superantigen-mediated T lymphocyte activation, along with its consequent cytokine production is thought to be the basis for the pathophysiology of conditions such as toxic shock syndrome, Kawasaki's disease and possibly rheumatoid arthritis. We examined the role of CD56+ NK lymphocytes in the interaction between superantigens and T lymphocytes. First, we found that a subpopulation of CD56+ cells freshly isolated from human peripheral blood expressed class II MHC molecules. The amount of HLA-DR expression varied between individuals, ranging from 9.3% to 37.7%. CD56+ (NK) cells were purified from the peripheral blood by cell sorting and were tested for their ability to support SEB-mediated T cell activation as assessed by surface expression of IL-2 receptor alpha-chain (CD25) on CD3+ lymphocytes. We observed that when enriched T cells were incubated with SEB in the presence of NK cells, there was a significant up-regulation of CD25 expression of the T cells. When HLA-DR+ cells were removed from sorted CD56+ populations, the remaining HLA-DR- NK cells were unable to support SEB-mediated T cell activation. Also, SEB up-regulated the expression of HLA-DR on CD56+ cells in peripheral blood mononuclear cell (PBMC) populations after 24 h of incubation, implying that the ability of NK cells to function as superantigen-presenting cells is up-regulated by superantigens themselves. Together, these data demonstrate for the first time that human CD56+ HLA-DR+ NK cells can function as superantigen-presenting cells, and imply that NK cells may be involved in the activation of non-specific T cell reactivity during early host defences against superantigen-elaborating microorganisms in vivo. Furthermore, the physical linkage of NK cells and T cells by the interaction of superantigen with HLA class II molecules and T cell receptors, respectively, may lead to NK cell activation and augmented lytic potential, helping to clear the body of superantigen-elaborating microorganisms.
8609118 Nitric oxide: an important articular free radical. 1996 Feb Nitric oxide is a small molecule that is synthesized by a family of enzymes, the nitric oxide synthases, and is overproduced in rheumatoid arthritis and osteoarthrosis. The aim of this investigation was to elucidate the potential sources of nitric oxide in joint tissues and to determine if the production of nitric oxide could be inhibited by dexamethasone or methotrexate, two agents that inhibit other forms of inducible nitric oxide synthase. Methotrexate inhibits the synthesis of biopterin, which is a co-factor for nitric oxide synthase. Explants of human and bovine cartilage and cultured chondrocytes released large amounts of nitrite, the stable end product of nitric oxide, when stimulated with endotoxin, interleukin-1 beta, or tumor necrosis factor-alpha. The production of nitrite was time-dependent and endotoxin, interleukin-1 beta, and tumor necrosis factor-alpha dose-dependent and was inhibited by the nitric-oxide-synthase inhibitors N omega-nitro-L-arginine methyl ester and aminoguanidine. The inducible nitric oxide synthase in bovine chondrocytes was calcium-dependent and was inhibited by high concentrations of methotrexate or dexamethasone. No constitutive nitric-oxide-synthase activity and little or no inducible nitric-oxide-synthase activity were demonstrable in explants or cell cultures derived from menisci. Fresh explants of bovine articular synovial tissue constitutively released nitrite that was inhibited by N omega-nitro-L-arginine methyl ester, but the release could not be enhanced by endotoxin, interleukin-1 beta, or tumor necrosis factor-alpha. There was no constitutive or inducible production of nitrite by explants or cells derived from the synovial tissue or shoulder capsule of a human or by explants or cells derived from canine anterior cruciate, posterior cruciate, medial collateral, lateral collateral, or patellar ligaments. Taken together, these results indicate that chondrocytes represent the major source of inducible nitric oxide synthase and nitric oxide during inflammation or infection of a joint.
8790778 The significance of vasoactive intestinal polypeptide (VIP) in immunomodulation. 1996 Evidence for VIP influences on immune function comes from studies demonstrating VIP-ir nerves in lymphoid organs in intimate anatomical association with elements of the immune system, the presence of high-affinity receptors for VIP, and functional studies where VIP influences a variety of immune responses. Anatomical studies that examine the relationship between VIP-containing nerves and subpopulations of immune effector cells provide evidence for potential target cells. Additionally, the presence of VIP in cells of the immune system that also possess VIP receptors implies an autocrine function for VIP. The functional significance of VIP effects on the immune system lies in its ability to help coordinate a complex array of cellular and subcellular events, including events that occur in lymphoid compartments, and in musculature and intramural blood circulation. Clearly, from the work described in this chapter, the modulatory role of VIP in immune regulation is not well understood. The pathways through which VIP can exert an immunoregulatory role are complex and highly sensitive to physiological conditions, emphasizing the importance of in vivo studies. Intracellular events following activation of VIP receptors also are not well elucidated. There is additional evidence to suggest that some of the effects of VIP on cells of the immune system are not mediated through binding of VIP to its receptor. Despite our lack of knowledge regarding VIP immune regulation, the evidence is overwhelming that VIP can interact directly with lymphocytes and accessory cells, resulting in most cases, but not always in cAMP generation within these cells, and a subsequent cascade of intracellular events that alter effector cell function. VIP appears to modulate maturation of specific populations of effector cells, T cell recognition, antibody production, and homing capabilities. These effects of VIP are tissue-specific and are probably dependent on the resident cell populations within the lymphoid tissue and the surrounding microenvironment. Different microenvironments within the same lymphoid tissue may influence the modulatory role of VIP also. Effects of VIP on immune function may result from indirect effects on secretory cells, endothelial cells, and smooth muscle cells in blood vessels, ducts, and respiratory airways. Influences of VIP on immune function also may vary depending on the presence of other signal molecules, such that VIP alone will have no effect on a target cell by itself, but may greatly potentiate or inhibit the effects of other hormones, transmitters, or cytokines. The activational state of target cells may influence VIP receptor expression in these cells, and therefore, may determine whether VIP can influence target cell activity. Several reports described in this chapter also indicate that VIP contained in neural compartments is involved in the pathophysiology of several disease states in the gut and lung. Release of inflammatory mediators by cells of the immune system may destroy VIP-containing nerves in inflammatory bowel disease and in asthma. Loss of VIPergic nerves in these disease states appears to further exacerbate the inflammatory response. These studies indicate that altered VIP concentration can have significant consequences in terms of health and disease. In addition, the protective effects of VIP from tissue damage associated with inflammatory processes described in the lung also may be applicable to other pathological conditions such as rheumatoid arthritis, anaphylaxis, and the swelling and edema seen in the brain following head trauma. While VIP degrades rapidly, synthetic VIP-like drugs may be developed that interact with VIP receptors and have similar protective effects. Synthetic VIP-like agents also may be useful in treating neuroendocrine disorders associated with dysregulation of the hypothalamic-pituitary-adrenal axis, and pituitary release of prolactin.
8064227 Effect of altered CH2-associated carbohydrate structure on the functional properties and i 1994 Sep 1 Immunoglobulin G (IgG) molecules are glycosylated in CH2 at Asn297; the N-linked carbohydrates attached there have been shown to contribute to antibody (Ab) stability and various effector functions. The carbohydrate attached to the IgG constant region is a complex biantennary structure. Alterations in the structure of oligosaccharide have been associated with human diseases such as rheumatoid arthritis and osteoarthritis. To study the effects of altered carbohydrate structure on Ab effector function, we have used gene transfection techniques to produce mouse-human chimeric IgG1 Abs in the Chinese hamster ovary (CHO) cell line Lec 1, which is incapable of processing the high-mannose intermediate through the terminal glycosylation steps. We also produced IgG1 Abs in Pro-5, the wild-type CHO cell line that is the parent of Lec 1. The Pro-5-produced Ab (IgG1-Pro-5) was similar to IgG1-My 1, a myeloma-produced IgG1 Ab of the same specificity, in its biologic properties such as serum half-life, ability to effect complement-mediated cytolysis, and affinity for Fc gamma RI. Although the Lec 1-produced Ab, IgG1-Lec 1, was properly assembled and retained antigen specificity, it was incapable of complement-mediated hemolysis and was substantially deficient in complement consumption, C1q binding, and C1 activation. IgG1-Lec 1 also showed reduced but significant affinity for Fc gamma R1 receptors. The in vivo half-life of IgG1-Lec 1 was shorter than that of either the myeloma- or Pro-5-produced counterpart, with more being cleared during the alpha-phase and with more rapid clearance during the beta-phase. Clearance of IgG1-Lec 1 could be inhibited by the administration of yeast-derived mannan. Thus the uptake of IgG1-Lec 1 appears to be accelerated by the presence of terminally mannosylated oligosaccharide. Therefore, certain Ab functions as well as the in vivo fate of the protein are dramatically affected by altered carbohydrate structure. Expression of Igs in cell lines with defined glycosylation mutations is shown to be a useful technique for investigating the contribution of carbohydrate structure to Ab function.
8453094 Epidemiology of aplastic anemia in France: a case-control study. I. Medical history and me 1993 Mar 15 Aplastic anemia (AA) is a rare, severe disease of mainly unknown origin. Numerous case history reports have incriminated drugs in the etiology of this disease. Because those reports were questionable, a case-control study was conducted in France between 1985 and 1988. Cases selected from the national register were eligible for inclusion when at least two blood lineages were depressed (hemoglobin < or = 10 g/100 mL and reticulocytes < or = 50 x 10(9)/L, granulocytes < or = 1.5 x 10(9)/L, platelets < or = 100 x 10(9)/L) and when the bone marrow biopsy was compatible with the disease. Using a standardized questionnaire, trained investigators interviewed one AA patient and two groups of controls (two hospitalized patients and one neighbor of the AA patient) matched for age, sex, and interviewer. One hundred forty-seven AA patients, 287 hospitalized controls, and 108 neighbors were interviewed. The occurrence of AA was analyzed by matched design with relation to medical history and drug use during the last 5 years, and specifically during the last year. Three times as many AA patients reported having suffered from clinical hepatitis during the last 6 months than either type of control. Similarly, a higher proportion of AA patients reported a history of chronic immune disorder, mainly rheumatoid arthritis (odds ratio of 6.8), and a previous use of gold salts and D-penicillamine in the 5 previous years (odds ratio of 4.9 for each drug). An excess of colchicine and allo/thiopurinol intake in the 5 previous years was observed among the AA patients (odds ratio equal to 4.1 and 3.6, respectively). These results for gold salts, D-penicillamine, and colchicine were confirmed when looking for drug use within the last year. A moderate risk was associated with acetaminophen or salicylate intake during the 5 previous years or during the last year (odds ratio between 1.8 and 2.0). The frequent use of salicylates within the last year was associated with a high risk of AA (odds ratio of 5.0). A high risk was also associated with indolic derivative intake but only when comparing AA patients to neighbor controls. No association could be evidenced with diclofenac intake, whatever the control group. Differences observed with recently published studies suggest that targeted studies on each category of drugs according to the treated pathologies should be initiated.
1427978 Inhibition of interleukin-1 beta mRNA expression and interleukin-1 alpha and beta secretio 1992 Oct The transcription and translation of interleukin-1 (IL-1) may have a pleiotropic effect on the immune system and inflammatory diseases. Recently it has been reported that human monocytes not only produce IL-1 but also induce, with adherent IgG, the secretion of an IL-1 receptor antagonist (IL-1Ra), which can play an essential in vivo and in vitro role in the regulation of IL-1 activity. Recombinant human (rh) IL-1Ra is structurally similar to IL-1 beta but with no IL-1-like activity, and specifically binds to the IL-1 receptor. To more fully evaluate and clarify the inhibitory effect of rhIL-1 receptor antagonist on IL-1 we have studied the influence of rhIL-1Ra on IL-1 transcription and translation. In this report we show that IL-1 beta mRNA from peripheral blood mononuclear cells (PBMC) is strongly inhibited (66%) when rhIL-1Ra (250 ng/ml) was added to cultured cells activated with lipopolysaccharide (LPS) (100 ng/ml) for 4 hr, determined with the slot blot analysis. The addition of exogenous rhIL-1 beta to the cell culture diminished the inhibitory effect (44%). Moreover, we report that the block of IL-1 mRNA transcription consequently leads to the inhibition of IL-1 alpha and IL-1 beta secretion in human PBMC, as measured by ELISA method. In fact, herein we show that LPS activates human PBMC to secrete IL-1 beta and IL-1 alpha, an effect inhibited, in a dose-dependent fashion by rhIL-1Ra (0.025-250 ng/ml) in an overnight incubation. Since IL-1 is a strong inducer of IL-1 synthesis in vivo and in vitro, in our study we used rh IL-1 alpha to stimulate the secretion of IL-1 beta in human PBMC. This activation, carried out overnight, also provoked the release of IL-1 beta in a dose-dependent manner, which was strongly inhibited by rhIL-1Ra used at different concentrations (0.025-250 ng/ml). The inhibitory effect exerted by IL-1Ra on human PBMC IL-1 mRNA transcription and the down-regulation of secretion of IL-1 beta stimulated by IL-1 alpha, may contribute to therapeutic effects in inflammatory diseases such as rheumatoid arthritis and other autoimmune diseases.(ABSTRACT TRUNCATED AT 400 WORDS)
1739981 Articular chondrocytes secrete IL-1, express membrane IL-1, and have IL-1 inhibitory activ 1992 Mar Previous work from our laboratory has shown that rabbit articular chondrocytes, like macrophages, produce reactive oxygen intermediates, express Ia antigen, and can mediate immunologic functions such as antigen presentation and induction of mixed and autologous lymphocyte reactions. We were interested in seeing if these cells could secrete interleukin-1 (IL-1) or express membrane form of IL-1 (mIL-1). Using the standard C3H/HeJ thymocyte assay, neither secreted IL-1 nor mIL-1 activity was detected in untreated or LPS-treated chondrocytes. However, the D10.G4.1 proliferation assay showed that chondrocytes, stimulated with LPS, secrete IL-1 and express the mIL-1 in a dose- and time-dependent manner. The IL-1 activity in LPS-stimulated chondrocyte supernatant and on fixed cells could be inhibited by anti-IL-1 antibodies. Sephadex G-75 chromatography of pooled, concentrated LPS culture supernatant resolved into two peaks of IL-1 activity at 13-17 and at 45-70 kDa, respectively. The bioactivity of chromatographic fractions were similar using both the thymocyte and D10.G4.1 bioassays. Western blot analysis of chondrocyte supernatant detects 17-kDa IL-1 beta; no processed 17-kDa IL-1 alpha was seen but IL-1 alpha-specific reactivity was observed at 64 kDa. Immunoblot analysis of chondrocyte lysates shows that cell-associated IL-1 is IL-1 alpha and is 37 kDa in size. PCR analysis shows the presence of mRNA for IL-1 beta and IL-1 alpha in LPS-treated cells; IL-1 beta mRNA was detected in untreated chondrocytes. The inability to detect IL-1 by the thymocyte assay is due to the presence of a chondrocyte inhibitor of IL-1 that can be demonstrated in cell sonicates, supernatants, and on paraformaldehyde-fixed chondrocytes. Chromatography of LPS-stimulated supernatant showed a peak of IL-1 inhibitory activity at 21-45 kDa. Chondrocytes which secrete IL-1 and express mIL-1 could play a critical role in maintaining chronic inflammation in rheumatoid arthritis. Therefore, the ability of chondrocytes to produce both IL-1 and an inhibitor to IL-1 is important in interpreting the mechanism of cartilage matrix maintenance and degradation.