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)

Hydralazine caused site-specific DNA damage in the presence of Cu(II), Co(II), Fe(III), or peroxidase/H2O2. The order of inducing effect of metal ions on hydralazine-dependent DNA damage [Cu(II) greater than Co(II) greater than Fe(III)] was related to that of accelerating effect on the O2 consumption rate of hydralazine autoxidation. Catalase completely inhibited DNA damage by hydralazine plus Cu(II), but hydroxyl radical (.OH) scavengers and superoxide dismutase did not. On the other hand, DNA damage by hydralazine plus Fe(III) was inhibited by catalase and .OH scavengers. Hydralazine plus Cu(II) induced piperidine-labile sites predominantly at guanine and some adenine residues, whereas hydralazine plus Fe(III) caused cleavages at every nucleotide. Activation of hydralazine by peroxidase/H2O2 caused guanine-specific modification in DNA. ESR-spin trapping experiment showed that .OH and superoxide are generated during the Fe(III)- or Cu(II)-catalysed autoxidation of hydralazine, respectively, and that nitrogen-centered radical is generated during the Cu(II)- or peroxidase-catalysed oxidation. The generation of nitrogen-centered radical was also supported by HPLC-mass spectrometry. The results suggest that the guanine-specific modification by the enzymatic activation of hydralazine is due to the nitrogen-centered hydralazyl radical or derived active species, whereas .OH participates in DNA damage by hydralazine plus Fe(III). The mechanism of hydralazine plus Cu(II)-induced DNA damage is complex. The possible role of the DNA damage induced by hydralazine in the presence of Cu(II) or peroxidase/H2O2 is discussed in relation to hydralazine-induced lupus, mutation, and cancer.
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PMID:Free radical production and site-specific DNA damage induced by hydralazine in the presence of metal ions or peroxidase/hydrogen peroxide. 184 78

Factors that potentially affect the generation of excess low molecular weight DNA (LMW-DNA) in cultured phytohemagglutinin (PHA)-stimulated lymphocytes of patients with systemic lupus erythematosus (SLE) were studied because this species of DNA is consistently found and this DNA may play a role in the pathogenesis of the disease. Superoxide dismutase (SOD; 0.05 mg/mL), a scavenger of free radical oxygen, decrease LMW-DNA formation in lymphocytes by 22%. Co-cultivation with cysteamine, a second scavenger of free radical oxygen and a sulfhydryl radioprotective agent, resulted in a 32% decrease in the generation of excess LMW-DNA at a concentration of 0.5 x 10(-3) mol/L and largely prevented its formation at 1.0 x 10(-3) mol/L. Other free radical scavengers (catalase, mannitol, vitamins C and E), cyclooxygenase inhibitors (ibuprofen and aspirin), a xanthine oxidase inhibitor (allopurinol), and an iron chelator (desferoxamine) did not affect excess LMW-DNA formation. Glutathione (1 x 10(-3) mol/L) had no effect and cysteine was toxic. Because scavengers of free radicals might be useful in the therapy of lupus, a trial of cysteamine (30 to 60 mg/kg/d) was administered to six acutely ill patients with SLE. A therapeutic benefit was not demonstrated, and some patients had exacerbation of disease. Lymphocyte cell growth from control and lupus subjects was stimulated when cysteamine, 1 x 10(-5) to 1 x 10(-4) mol/L was added to the media, but inhibited at concentrations of 2 x 10(-4) mol/L or greater. These studies suggest that the autooxidation and toxicity of high-dose cysteamine preclude its therapeutic use as a free radical scavenger.
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PMID:Scavengers of free radical oxygen affect the generation of low molecular weight DNA in stimulated lymphocytes from patients with systemic lupus erythematosus. 224 68

An almost universal side effect of long-term therapy with procainamide is the appearance of serum autoantibodies and less frequently a syndrome resembling lupus erythematosus. Previous studies demonstrated that procainamide-hydroxylamine (PAHA), a metabolite generated by hepatic mixed function oxidases, was highly toxic to dividing cells, but evidence that PAHA could be formed in the circulation was lacking. This study examines the capacity of neutrophils to metabolize procainamide to reactive forms. Neutrophils activated with opsonized zymosan were cytotoxic only if procainamide was present, whereas N-acetyl procainamide, which does not induce autoimmunity, was inert in this bioassay. PAHA was detected by HPLC in the extracellular medium if ascorbic acid was present. Generation of PAHA and cytotoxic procainamide metabolites was inhibited by NaN3 and catalase but not by superoxide dismutase, indicating that H2O2 and myeloperoxidase were involved. Nonactivated neutrophils and neutrophils from patients with chronic granulomatous disease did not generate cytotoxic PAHA, demonstrating that H2O2 was derived from the respiratory burst accompanying neutrophil activation. These conclusions were supported by results of a cell-free system in which neutrophils were replaced by myeloperoxidase and H2O2 or an H2O2 generating system. These studies demonstrate the capacity of neutrophils to mediate metabolism of procainamide and establish the role of myeloperoxidase released during degranulation and H2O2 derived from the respiratory burst in the direct cooxidation of procainamide to PAHA. The profound biologic activity of this metabolite and its possible generation within lymphoid compartments implicate this process in the induction of autoimmunity by procainamide.
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PMID:Metabolism of procainamide to the cytotoxic hydroxylamine by neutrophils activated in vitro. 253 97

This article gives a synopsis of the inflammatory reactions as well as its mediators under special consideration of the efferent part of the reaction. There is no doubt that histamine, complement, and the kinin system play an essential role; arachidonic acid (eicosatetraenic acid) and its metabolites, however, have gained comparable significance: prostaglandines, prostacyclines, and thromboxanes as metabolites of the cyclo-oxygenase, the leucotrienes SRS-A (slow reacting substances of anaphylaxis) and ECF (eosinophilic chemotactic factor) mediated via lipoxygenase. Moreover, oxygen and its metabolites hydrogen peroxide (H2O2), peroxide radicals (O-2), and hydroxyl radicals (.OH) as well as activated oxygen (singulett oxygen (1O2) play an important part with all aerobic living organisms. Inborn enzyme deficiency of the oxygen metabolism such as NADPH oxidase or cytochrome b-245 deficiency lead to chronic septic granulomatosis. The disease is characterized by reduced resistence against infections, decreased phagocytosis, insufficient killing of bacteria by leucocytes, and diminished oxygen burst. Thus the underlying enzyme deficiency leads to reduced formation of peroxide radicals frequently causing infections with septic complications. On the other hand, increased formation or reduced degradation of peroxide radicals may result in pathological reactions like chromosomal alterations, lipidperoxidation or oxidation of sulph-hydryl groups. The fact that increased peroxide radical formation may cause inflammation or chromosomal aberration is of importance with regard to the pathogenesis of several chronic inflammatory diseases of unknown etiology, such as systemic scleroderma or lupus erythematodes. The enzyme superoxide dismutase (SOD) converts peroxide radicals (O-2) into hydrogen peroxide (H2O2) which can be inactivated by catalase or peroxidase. Consequently, treatment with SOD may have an effective influence on chronic inflammatory dermatoses of unknown pathogenesis.
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PMID:[Biochemical aspects of the inflammatory reaction - with special reference to oxygen]. 666 95

Increased chromosome breakage is observed in lymphocyte cultures from patients with so-called autoimmune diseases also in the animal model, the NZB mouse. A clastogenic agent was detected in the serum of patients and of NZB mice, that induces also chromosome breaks in cells of healthy individuals. In simultaneous cultures set up with or without superoxide dismutase in 5 patients with progressive systemic sclerosis, 5 patients with systemic lupus erythematosus and 5 patients with rheumatoid arthritis, highly significant differences in the incidence of chromosome breakage were observed. The aberration rate produced in blood cultures of healthy individuals by the breakage factor from patients was also reduced essentially to control values by addition of SOD in vitro, but were reduced also in vivo by injection of SOD in lupus patients as well as in NZB mice.
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PMID:Chromosome instability in human and murine autoimmune disease: anticlastogenic effect of superoxide dismutase. 693 6

Patients who have systemic lupus erythematosus have increased numbers of chromosome breaks and rearrangements correlated with a low molecular weight chromosome-damaging agent that is released from their lymphocytes into the serum. This clastogenic factor also produces chromosome breaks and sister chromatid exchanges in healthy persons' lymphocytes when they are incubated in the presence of lupus patients' serum or lymphocytes or purified factor. The lymphocytes from lupus patients are sensitive to near-UV (360- to 400-nm light. This sensitivity seems to be related to the presence of the clastogenic factor in these cells; lymphocytes of healthy persons exposed to the factor also become sensitive to light of the same wavelengths. A significant increase in nonviable cells (trypan blue exclusion test) was observed after 5 min of irradiation with 360- and 380-nm light in the presence of the factor. The number of chromosome aberrations observed after stimulation of the irradiated lymphocytes with phytohemagglutinin was also maximal after irradiation at 380 nm in presence of the factor. The combined action of near-UV light plus clastogenic factor was inhibited by superoxide dismutase if the enzyme were present during irradiation, suggesting that activation involves photoproduction of superoxide ions. Irradiation of the purified factor and immediate addition of it to lymphocytes gave the same results whereas preirradiation of cells or of medium was without effect. The presence of this photoactivated agent explains why patients who have lupus erythematosus show an aggravated condition after exposure to sunlight and the appearance of typical skin lesions.
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PMID:Mechanism of photosensitivity in systemic lupus erythematosus patients. 694 6

Chromosome instability is observed in patients with collagen disease. It is due to the presence of a chromosome-breaking agent in the serum which also induces chromosome breaks and rearrangements in blood cultures from healthy subjects. It is not possible to say at present whether this breakage factor is identical to that in patients with progressive systemic sclerosis, lupus erythematosus or rheumatoid arthritis. In all three diseases the agent is a substance with a low molecular weight between 1000 and 10,000 daltons. Since the enzyme superoxide dismutase has an anticlastogenic protective effect, the action of the agent on chromosomes is probably an indirect one, namely by generation of oxygen-dependent free radicals such as O2- x and OH.
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PMID:Chromosomal instability in collagen disease. 742 3

Free radical processes are proposed to play a crucial role in the development of procainamide adverse effects. Therefore, selenium, as a potent antioxidant, may modified procainamide toxicity. To test this hypothesis plasma and liver thiobarbituric acid-reacting substances (TBARS), plasma antioxidant activity (AOA), erythrocyte and liver superoxide dismutase (SOD), catalase, as well as selenium-dependent glutathione peroxidase (Se-GPX) were determined in the following four groups of rats: selenium-treated (Se), procainamide-treated (P), procainamide and selenium-treated (P + Se), and control (C). Morphological studies of leukocytes [tested for lupus erythematosus (LE) cells] and liver were also made. Atypical, i.e. enlarged and swollen, leukocytes resulting from procainamide and selenium treatment were observed. These changes were found in four out of five rats in the Se group, eight out of ten in the P group, and in seven out of ten in the P + Se group. LE-like cells were observed in two rats in the P + Se group. A statistically significant decrease in plasma and liver TBARS by 20% and 36%, respectively, increased activity of SOD by 20%, catalase by 48% and Se-GPX by 15% in erythrocytes, and decreased activity of liver SOD by 17% and catalase by 22% were found in the P + Se group as compared to the P group. These results indicated that selenium exerted antioxidant effects on the procainamide-treated rats. However, selenium did not prevent the development of disturbances in leukocyte morphology, on the contrary, it possibly promoted the conversion of leukocytes to LE cells.
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PMID:Modulation of procainamide toxicity by selenium-enriched yeast in rats. 813 60

Enrichment of diet with omega-3 lipid rich-menhaden fish oil (FO) when fed ad libitum to autoimmune lupus-prone NZB/NZW F1 (B/W) female mice delayed the onset and slowed progression of renal disease while significantly extending life-span compared to omega-6 lipid rich-corn oil (CO)-fed mice. Northern blot analysis of kidneys from FO-fed mice revealed no detectable levels of IL-1 beta, IL-6 and TNF alpha mRNA contrasted to levels that were easily detected in CO-fed mice. In contrast to the cytokines, FO-fed mice showed higher renal levels of the antioxidant enzymes-catalase, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD)-mRNAs compared to CO-fed mice. The results suggest that dietary supplementation with FO, as compared to CO, inhibits the production of pro-inflammatory cytokines and ameliorates immune-complex-mediated kidney injury possibly by enhancing the ability of cells to dispose of harmful reactive oxygen intermediates.
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PMID:Decreased pro-inflammatory cytokines and increased antioxidant enzyme gene expression by omega-3 lipids in murine lupus nephritis. 817 24

In a group of 65 patients with lupus nephropathy the level of lipid peroxidation and of the capacity of antioxidant protection was followed up as influenced by the activity of superoxide dismutase (SOD), of catalase (CAT) and of glutathione peroxidase (GSH-Px) as well as of the concentration of glutathione. The determinations were made in total blood and the results were compared with those obtained in a control group of 30 apparently healthy subjects. The degree of lipid peroxidation seemed to be correlated with the extent of proteinuria. As compared with the normal values the activity of the three enzymes studied was decreased and did not correlate with the level of proteinuria. The decreased SOD and GSH-Px seemed to be relatively compensated by CAT activity. The level of GSH was also decreased as compared with the control values and did not correlate with the value of proteinuria. It is concluded that the great variation of individual values could be explained by the multifactorial character of the disease as well as by the metabolic response specific for every patient and by the mechanisms possibly related to the onset of renal disease.
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PMID:Oxidant stress and antioxidant protection in lupus nephropathy. 890 37


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