Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0409974 (lupus)
 22,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A lupus-like syndrome involving chronic urticaria with cutaneous vasculitis, systemic symptoms, hypocomplementemia with preferential depletion of C1q, and low m.w. (7S) C1q-precipitins has recently been defined. The C1q-precipitin activity (C1q-p) seems to represent a diagnostic marker of the disease, but its chemical nature is not yet clear. We have partially purified and characterized C1q-p from the serum of two patients with this syndrome and compared its activity with the C1q-precipitating activity of aggregated human gamma-globulin (AHGG) anti-C1q antibodies, and several polynucleotides including DNA and polyinosinic acid. C1q-p was found to partition with IgG during precipitation by ammonium sulfate and low ionic strength buffer as well as during column chromatography on DEAE-cellulose and G-200 Sephadex. Like AHGG, but in complete contrast to the polynucleotides, the C1q-precipitating activity of C1q-p was sensitive to pepsin, trypsin, and acidic conditions, but unaffected by DNAse or RNAse; the C1q-precipitating activity of anti-C1q antibody was not diminished by any of these procedures. Thus, C1q-p consists of gamma-migrating protein of low m.w., and its C1q-precipitating activity is indistinguishable from that of AHGG. These results are consistent with the concept that C1q-p is comprised, at least in part, of IgG that binds C1q via the Fc portion of the molecule.
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PMID:Low molecular weight C1q-precipitins in hypocomplementemic vasculitis-urticaria syndrome: partial purification and characterization as immunoglobulin. 2 69

Antibodies that bind tRNA are produced spontaneously in New Zealand Black/New Zealand White (NZB/NZW) F1 hybrid female mice. An assay for the detection of these antibodies has been developed by using gel filtration and radioactive tRNA. This assay was found superior to the widely used ammonium sulfate precipitation assay because of the nature of the interaction between the protein and the tRNA. The ant-bodies bound native tRNA preferentially to tRNA denatured by cross-linking with formaldehyde. This conformational specificity was confirmed in competition experiments. The antibodies to native tRNA had an average association constant of 5 x 10(7) leter/mole at 4 degrees C and could bind to more than one site per tRNA molecule. Experiments with immunoglobulin class-specific anti-mouse antisera, in solution and by radioimmunoelectrophoresis, showed that the antibodies were heterogeneous, but were predominantly of the IgG class. These antibodies may be useful for detection, localization, and conformational analysis of tRNA in solution as well as for understanding the pathogenesis of the lupus-like syndrome in these mice.
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PMID:Properties of tRNA-specific antibodies from NZB/NZW mice. 32 80

The 25,000 dalton protein of Mason-Pfizer monkey virus (MPMV) was isolated by gel filtration chromatography. In agreement with results from other laboratories, antisera to type-C and the non-type-C bovine leukemia and equine infectious anemia viruses did not precipitate 125I-labelled MPMV p25. In addition, these viruses did not cross-react in a competition radioimmunoassay for MPMV p25. Twenty-one human tissues (15 breast carcinomas, 2 normal breasts, 3 acute myelogenous leukemias and 1 sarcoma) were fractionated by detergent solubilization, ammonium sulfate precipitation, and DE-52 anion exchange chromatography. These methods were shown to be highly effective for purification of MPMV p25. Under assay conditions which minimized incubation damage to the 125I-MPMV p25, all tissues failed to react in the competition radioimmunoassay (RIAT). Two hundred and two human sera or plasma specimens, including those from patients with breast cancer and 33 age-matched controls, from 50 patients with hematologic malignancies, from 12 patients with amyotrophic lateral sclerosis, and from 14 patients with systemic lupus erythematosis, were examined for antibodies to MPMV p25. With the exception of two multiple myeloma plasma which produced artifactual false positive reactions based on hypergammaglobulinemia, a known complication of salt precipitation radioimmunoassays, the remainder of the specimens were negative for evidence of MPMV p25 antibodies.
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PMID:Radioimmunoassay for the major structural protein of Mason-Pfizer monkey virus: Attempts to detect the presence of antigen or antibody in humans. 40 48

Clinical observations and experimental data suggest that sex hormones influence the development of systemic lupus erythematosus (SLE). An imbalance between androgen and estrogen plasma levels may suggest an abnormality in the aromatase activity involved in estradiol synthesis. Aromatase activity in skin and subcutaneous tissue and plasma sex-hormone levels (testosterone, androstenedione, estrone, estradiol, dehydrosterone sulfate, cortisol) were measured in 15 SLE patients (nine female, six male) who had never received corticosteroid treatment and in eight (four female, four male) healthy control subjects. There was a tendency toward an increase in aromatase activity in SLE patients when compared to control subjects. Among SLE patients the aromatase activity varied inversely with disease activity. Patients with SLE had decreased androgen and increased estrogen levels. Aromatase activity in SLE patients had significant direct correlation with estrogen levels. These data suggest that abnormal regulation of aromatase activity may partially explain the abnormalities of estrogen synthesis in SLE.
Lupus 1992 May
PMID:Plasma sex hormones and aromatase activity in tissues of patients with systemic lupus erythematosus. 130 81

Anti-double-stranded DNA (dsDNA) antibodies are highly specific for the diagnosis of systemic lupus erythematosus (SLE) but are heterogeneous in respect to, for example, avidity, class and cross-reactivity. Sera from 2061 patients were measured by three methods: an enzyme-linked immunosorbent assay (ELISA), an indirect immunofluorescence test with Crithidia luciliae as substrate (CLIF), and the Farr assay, a radioimmunological method based on the ammonium sulfate precipitation of immune complexes. The different anti-dsDNA antibody determinations were evaluated by analysis of patient records. The reason for a reactive Farr assay in 14 patients was predominantly the measurement of antibodies of the IgM class, which are not detected by the ELISA. The detection of additional antibodies to dsDNA of the IgA class, to single-stranded DNA or to histones plays a minor role. In comparison with the Farr assay, we found more positive results with the ELISA, which additionally detects anti-dsDNA antibodies of low avidity. The ELISA might also yield positive values in conditions such as chronic liver diseases, various infections and connective tissue diseases other than SLE. Avoiding the disadvantages of radioactivity, the ELISA is well suited as a screening test for dsDNA antibodies. However, positive results should be confirmed by the CLIF test or preferably by the Farr assay, thus combining sensitivity with specificity.
Lupus 1992 Dec
PMID:The clinical significance of measuring different anti-dsDNA antibodies by using the Farr assay, an enzyme immunoassay and a Crithidia luciliae immunofluorescence test. 130 5

The influence of charged polymers on the reaction of immunoglobulins from human lupus sera with cellular proteins was investigated in this study. Through immunoblotting it was shown that polyanions (dextran sulfate, heparin, polyinosinic acid) and polylysine inhibited autoantibody binding to several polypeptides of different molecular mass. Using immunofluorescent staining with affinity isolated monospecific autoantibodies it was demonstrated that the immunoreactivity of two nuclear antigens (p30 and p85) and one cytoplasmic antigen (p40) was sensitive to the presence of charged polymers. The inhibiting effect correlated with the concentration of the polymers. The data obtained suggested the competitive mechanism of inhibition of autoantibody-protein reaction by the charged polymers.
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PMID:Inhibiting effect of charged polymers on interaction of human lupus autoantibodies with certain intracellular proteins. 157 3

The human monoclonal autoantibody HF2-1/17, produced by a human-human hybridoma derived from lymphocytes of a lupus patient with thrombocytopenia, reacts with single stranded DNA and platelets. To determine the chemical nature of the autoantigen against which this antibody is directed on platelets, this platelet antigen was purified by the lipid extraction of sonicated platelets, DEAE-Sephadex chromatography, and high performance liquid chromatography. The purified glycolipids, a trace component in platelets, demonstrated high reactivity with the HF2-1/17 antibody using a competition enzyme-linked immunosorbent assay system or immunostaining of thin layer chromatograms. The purified glycolipids co-migrated with bovine sulfatides by thin layer chromatography. The purified glycolipids contain sulfate and galactose but not sialic acid or phosphate. Fast atom bombardment-mass spectrometry revealed these sulfatides to be sulfated monohexyl ceramides. The dominant species has a molecular weight of 794 while a minor form has a molecular weight of 812 due to an extra hydroxyl group and loss of a double bond. These results indicate that the platelet autoantigen against which the human monoclonal anti-DNA antibody is directed represents a family of novel monogalactosyl sulfatides.
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PMID:Sulfated glycolipids are the platelet autoantigens for human platelet-binding monoclonal anti-DNA autoantibodies. 186 60

The mechanisms responsible for the tissue injuries associated with lupus nephritis have not yet been well explained. We have investigated the characteristics of anti-DNA antibodies in circulating immune complexes (CIC) and in the deposits of renal glomeruli in patients with active lupus nephritis. The CIC-derived antibodies expressed anti-DNA idiotypes (Id) designated as 0-81 Id and NE-1 Id, and bound mainly to single-stranded DNA but never to glomerular basement membrane (GBM) antigens. On the other hand, the immunoglobulins (Ig) eluted from renal glomeruli of lupus patients reacted not only with DNA but also with GBM, proteoglycan, and heparan sulfate. The binding of glomeruli-deposited Ig was markedly low when GBM antigens were used after treatment with heparitinase, suggesting that some anti-DNA antibodies may bind directly to GBM antigens associated with heparan sulfate, and form in situ IC in renal glomeruli. It was also revealed that the renal eluates obtained after passing through GBM antigen-coupled Sepharose lost the binding ability with GBM but still retained DNA-binding and 0-81 Id activity, showing the participation of circulating IC-derived anti-DNA antibodies in the glomerular deposits. Theoretically there may be two mechanisms in the pathogenesis of lupus nephritis through the deposition of circulating IC and through in situ formation of anti-DNA IC in renal glomeruli. The diversity of histological features in lupus kidneys may be attributed to the heterogeneity of the mechanisms.
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PMID:Heterogeneity of immune complex-derived anti-DNA antibodies associated with lupus nephritis. 205 33

Glucocorticoids induce dramatic biochemical and morphological changes in lymphocytes through an unknown process that requires RNA and protein synthesis. In order to identify genes involved in this response, we previously isolated 11 cDNA clones from the murine WEHI-7TG thymoma cell line that correspond to mRNAs induced by glucocorticoids. We now report the isolation of two new cDNA clones whose gene expression is regulated by glucocorticoids in WEHI-7TG cells. We further characterize the two new cDNA clones, as well as those described previously, by examining the response of each of the corresponding mRNAs to glucocorticoids in murine thymocytes. With the exception of two, all cDNAs correspond to genes that are induced by glucocorticoids in murine thymocytes within 4 h of treatment. We previously identified two of the cDNAs as the mouse VL30 retrovirus-like element and the mouse homolog of chondroitin sulfate proteoglycan core protein. We have now identified four additional cDNA clones that correspond to the genes for calmodulin, mitochondrial phosphate carrier protein, immunoglobulin (Ig)-related glycoprotein (GP-70), and the 70 kilodalton autoantigen for Lupus and Graves diseases. Two other cDNA clones represent previously undescribed genes: one shares a high similarity to known sequences for the family of G-protein-coupled receptors and the other to a human placental-specific protein, PP11. Another cDNA appears to contain sequences for an unknown gene and the remnants of a mouse transposon. ETn. The remaining clones represent new, unidentified genes induced by glucocorticoids in murine thymocytes and in the WEHI-7TG cell line.
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PMID:Genes newly identified as regulated by glucocorticoids in murine thymocytes. 207 23

The numerous clinical and experimental data suggesting a lupus-induced modulation of sex hormones prompted the study of sex hormone metabolism in these patients. Some hormonal abnormalities were reported in female patients: a) over production of 16-alpha-hydroxylated estradiol derivatives with potent peripheral estrogenic activities; b) under production of the following androgens: testosterone, dihydrotestosterone, dihydroandrosterone, dihydroandrosterone sulfate, delta 4-androstenedione. Moreover, some observations suggest an excessive transformation of androgens into estrogens: increased oxidation of testosterone on C17, skin lesions, abnormal skin, aromatase activity responsible for estradiol synthesis.
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PMID:[Sex hormone metabolism in acute systemic lupus erythematosus]. 236 14


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