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PubMed1993

HLA-DR1-positive patients suffering from rheumatoid arthritis are at high risk for developing mucocutaneous side effects upon gold therapy.

Population studies suggest an association between RA and, depending on the ethnic background, HLA-DR1 and/or -DR4. One standard regimen for the treatment of RA is the use of gold compounds like SATM to arrest progression of the disease. In the present study, the immunogenetic background of RA patients developing side effects upon SATM treatment was determined. A total of 53 patients under SATM therapy were tested for their HLA-DRB and -DQ alleles by DNA typing; a significantly higher frequency of HLA-DR1 (p < 0.004, uncorrected) was observed in patients presenting with mucocutaneous side effects (MCT) when compared with patients without MCT. The RR was 6.85. Thus, HLA-DR1 seems to be a marker for the susceptibility of gold adverse reactions.

Adult↗
PubMed2006

Aurothiomalate inhibits transformed growth by targeting the PB1 domain of protein kinase Ciota.

We recently identified the gold compound aurothiomalate (ATM) as a potent inhibitor of the Phox and Bem1p (PB1)-PB1 domain interaction between protein kinase C (PKC) iota and the adaptor molecule Par6. ATM also blocks oncogenic PKCiota signaling and the transformed growth of human lung cancer cells. Here we demonstrate that ATM is a highly selective inhibitor of PB1-PB1 domain interactions between PKCiota and the two adaptors Par6 and p62. ATM has no appreciable inhibitory effect on other PB1-PB1 domain interactions, including p62-p62, p62-NBR1, and MEKK3-MEK5 interactions. ATM can form thio-gold adducts with cysteine residues on target proteins. Interestingly, PKCiota (and PKCzeta) contains a unique cysteine residue, Cys-69, within its PB1 domain that is not present in other PB1 domain containing proteins. Cys-69 resides within the OPR, PC, and AID motif of PKCiota at the binding interface between PKCiota and Par6 where it interacts with Arg-28 on Par6. Molecular modeling predicts formation of a cysteinyl-aurothiomalate adduct at Cys-69 that protrudes into the binding cleft normally occupied by Par6, providing a plausible structural explanation for ATM inhibition. Mutation of Cys-69 of PKCiota to isoleucine or valine, residues frequently found at this position in other PB1 domains, has little or no effect on the affinity of PKCiota for Par6 but confers resistance to ATM-mediated inhibition of Par6 binding. Expression of the PKCiota C69I mutant in human non-small cell lung cancer cells confers resistance to the inhibitory effects of ATM on transformed growth. We conclude that ATM inhibits cellular transformation by selectively targeting Cys-69 within the PB1 domain of PKCiota.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Action of gold chloride ("gold toning") on silver-enhanced 1 nm gold markers.

In conventional immunoelectron microscopy (IEM), very small colloidal gold particles (0.8-3 nm), or the gold compound Nanogold (1.4 nm) are silver-enhanced for easy detection. However, silver enhancement has drawbacks. First, the silver layer is dissolved during fixation with osmium tetroxide, even if the concentration and incubation time are strongly reduced during pre-embedding labeling experiments in transmission electron microscopic (TEM) and scanning electron microscopic (SEM) studies. Second, after exposure to the electron beam the silver layer may migrate on the section or the whole particles may disappear. Sometimes silver migration can be observed even without irradiation. This effect strongly hampers reinvestigation of previously inspected areas, after some time of storage. In both cases, gold chloride treatment after silver enhancement is sufficient to completely protect the silver-enhanced 1 nm gold markers. Gold chloride treatment is part of the so-called "gold toning" procedure, which is a method used to substitute and/or cover the silver by a layer of gold. It can be applied in TEM and SEM experiments. As a serious drawback, gold chloride treatment slightly reduces the size of both unenhanced and silver-enhanced gold particles and can lead to disintegrated silver/gold particles. Therefore, this technique is useful for pre-embedding IEM, on-(resin)section, and ultrathin cryosection labeling experiments. However, it appears to be unsuitable for double-labeling studies using different gold sizes, for quantitation experiments, and in SEM.

Cryoultramicrotomy↗
PubMed2005

The quadrupole moment of the 3/2+ nuclear ground state of 197Au from electric field gradient relativistic coupled cluster and density-functional theory of small molecules and the solid state.

An attempt is made to improve the currently accepted muonic value for the 197Au nuclear quadrupole moment [+0.547(16)x10(-28) m2] for the 3/2+ nuclear ground state obtained by Powers et al. [Nucl. Phys. A230, 413 (1974)]. From both measured Mossbauer electric quadrupole splittings and solid-state density-functional calculations for a large number of gold compounds a nuclear quadrupole moment of +0.60x10(-28) m2 is obtained. Recent Fourier transform microwave measurements for gas-phase AuF, AuCl, AuBr, and AuI give accurate bond distances and nuclear quadrupole coupling constants for the 197Au isotope. However, four-component relativistic density-functional calculations for these molecules yield unreliable results for the 197Au nuclear quadrupole moment. Relativistic singles-doubles coupled cluster calculations including perturbative triples [CCSD(T) level of theory] for these diatomic systems are also inaccurate because of large cancellation effects between different field gradient contributions subsequently leading to very small field gradients. Here one needs very large basis sets and has to go beyond the standard CCSD(T) procedure to obtain any reliable field gradients for gold. From recent microwave experiments by Gerry and co-workers [Inorg. Chem. 40, 6123 (2001)] a significantly enhanced (197)Au nuclear quadrupole coupling constant in (CO)AuF compared to free AuF is observed. Here, these cancellation effects are less important, and relativistic CCSD(T) calculations finally give a nuclear quadrupole moment of +0.64x10(-28) m2 for 197Au. It is argued that it is currently very difficult to improve on the already published muonic value for the 197Au nuclear quadrupole moment.

Journal Article↗
PubMed1984

Oral gold: a comparison with placebo and with intramuscular sodium aurothiomalate.

The therapeutic and toxic effects of the orally absorbed gold compound auranofin have been compared with placebo and parenterally administered sodium aurothiomalate (GST) in 90 patients with active rheumatoid arthritis over one year. At the end of this period 57% of patients on auranofin, 73% on GST and 0% on placebo remained on therapy. Toxicity caused discontinuation of therapy in 10% of patients on auranofin, 20% on GST and 7% on placebo. Lack of response to therapy led to withdrawal of 20% on auranofin, 0% on GST and 90% on placebo. Multiple clinical and biochemical assessments were performed during this study. Analysing them separately, and in the case of 6 of them grouped together in a disease activity index, the same trend is apparent throughout, namely that placebo has no effect on active inflammatory rheumatoid arthritis, and that both gold drugs are beneficial. GST has an earlier effect and tends to produce a greater change but after one year there was no significant difference between the 2 gold drugs for any parameter assessed. Gold levels in plasma or erythrocytes did not predict or correlate with either the development of toxicity or clinical efficacy. This study has demonstrated the second-line potential of auranofin which seems to be effective at gold concentrations in the blood below those observed with GST therapy. Toxicity limits the use of gold salts in RA. If the reduced incidence of adverse reaction with auranofin observed in this study is substantiated in larger numbers over prolonged periods, the use of gold at an earlier stage of disease may be facilitated.

Administration, Oral↗
PubMed1991

Auranofin inactivates phosphofructokinase in human neutrophils, leading to depletion of intracellular ATP and inhibition of superoxide generation and locomotion.

The effects of the oral gold compound auranofin (AF), at concentrations well within the therapeutic range (0.04-1.5 microM), on human neutrophil functions and energy metabolism were investigated in vitro. At the concentrations tested, this agent had minimal effects on neutrophil degranulation and phagocytosis. However, AF caused dose-related inhibition of neutrophil chemotaxis and stimulus-activated generation of superoxide, which was evident at concentrations as low as 0.04 microM. Inhibition of superoxide generation by activated neutrophils increased with the time of preincubation of the cells with AF at 37 degrees. At low concentrations of AF (less than 0.75 microM), early events (within 5 min) involved in the transduction, assembly, and activity of the neutrophil superoxide-generating enzyme NADPH oxidase appeared to be normal, but the cells were unable to sustain the level of oxygen consumption, superoxide production, and NADPH oxidase activity of the corresponding drug-free control cells. On a mechanistic level, coincubation of neutrophils with AF was associated with decreased glycolytic activity and depletion of intracellular ATP, apparently due to drug-mediated, dose-related inactivation of the glycolytic enzyme phosphofructokinase (PFK). Using purified PFK, the triethylphosphine gold (TEPG) moiety of AF, but not AF per se, caused dose-related inactivation of enzyme activity. These data indicate that the potent inhibition of neutrophil migration and reactive oxidant generation observed during treatment of neutrophils with low, therapeutically attainable concentrations of AF is related to TEPG-mediated inactivation of PFK and consequent interference with cellular energy metabolism and functions.

Adenosine Triphosphate↗
PubMedDate not supplied

Auranofin treatment for adult rheumatoid arthritis. Comparison of 2 mg and 6 mg daily dose.

Auranofin, an orally effective gold compound, was administered to 2 groups of rheumatoid arthritis patients at 2 mg and 6 mg daily respectively in a controlled study. Both groups showed significant improvement in most efficacy measurements by 6 months. More improvement measurements were observed in the 6 mg group at 3 months than the 2 mg group. Dropout rate because of diarrhea was similar in the 2 groups. Other adverse reactions severe enough to force withdrawal of the test drug were infrequent.

Arthritis, Rheumatoid↗
PubMed1985

Three kinds of foamy cells in the spleen: comparative histochemical and ultrastructural studies.

By light and electron microscopy, we observed foamy cells in the spleens from a patient with hemolytic anemia due to red cell adenosine deaminase (ADA) overproduction, a patient with rheumatoid arthritis (RA) treated with gold, and patients with idiopathic thrombocytopenic purpura (ITP). The foamy cells associated with red cell ADA overproduction were essentially similar to Gaucher-like cells described in patients with thalassemia, and it was suggested that the accelerated destruction of red cells was one of the factors responsible for the development of foamy cells. Foamy cells in ITP and RA were closely associated with an increased destruction of platelets in the spleen. Morphologic transitions between phagocytosed platelets and myelin-like materials were traced in these disorders. In RA, however, foamy cells were heterogeneous from an ultrastructural standpoint, with different cytoplasmic inclusions. In addition to myelin-like materials, dense bodies, vacuoles with flocculent materials, and gold were noted in most of foamy cells. As gold compounds are known to inhibit lysosomal enzymes, we surmise that an acquired disturbance in lysosomal digestion is partially responsible for the accumulation of intermediate metabolites. In the pathogenesis of foamy cells associated with blood cell dyscrasia, the accelerated destruction of blood cells and/or acquired disorders in catabolic pathways within the macrophages are suggested to be the underlying mechanism of an intralysosomal accumulation of incompletely degraded cellular debris.

Adenosine Deaminase↗
PubMed1992

Differentiation of the U-937 promonocytic cell line induced by phorbol myristate acetate or retinoic acid: effect of aurothiomalate.

Tissue macrophages, which participate in chronic synovial inflammation, differentiate from haemopoietic precursors in bone marrow and subsequently in tissue. During this process, they acquire attributes which are essential for their function in inflammation. Modulation of this process may represent a means of regulating inflammatory competence of macrophages in inflammatory joint disease. The action of aurothiomalate (ATM), an anti-rheumatic gold compound, on the differentiation of a promonocytic cell line (U937) was, therefore, examined in in vitro systems. U937 cells exposed to retinoic acid (RA) for 4 days or to phorbol myristate acetate (PMA) for 2 days acquired characteristics of macrophages, including the capacity to produce superoxide (O2-), responsiveness to formyl-methionyl-leucyl-phenylalanine (fMLP) and reduced proliferation. The activity of transglutaminase also increased in RA-exposed cultures. The effect of ATM exposure on acquisition of these characteristics was small and differed between RA- and PMA-stimulated cells.

Cell Differentiation↗
PubMedDate not supplied

Primary tumor growth and formation of spontaneous lung metastases in mice bearing Lewis carcinoma treated with proteinase inhibitors.

The differential effects on primary tumor growth and on the formation of spontaneous pulmonary metastases have been determined for a series of proteinase inhibitors. The substances included the gold compounds, aurothioglucose and aurothiomalate, D(-)penicillamine, phosphoramidon and an egg-white inhibitor of cysteine proteinase (EWI). The i.p. administration of these substances to mice bearing s.c. Lewis lung carcinoma cause varying degrees of antineoplastic effects; the most pronounced effects on metastases are caused by phosphoramidon. The inactivity of EWI on tumor progression is concomitant with an inhibition to 50% of cathepsin B in tumor homogenates. The selective antimetastatic action of phosphoramidon is in agreement with the crucial role proposed for tumor collagenases in tumor dissemination.

Animals↗
PubMed1988

Waaler Rose titres may decrease but increase again during chrysotherapy.

In 62 patients with seropositive rheumatoid arthritis, treated with gold compounds, the relationship between serological and clinical response was analysed, based on data on the rheumatoid factor (RF) titre, ESR, number of swollen joints and joint tenderness, through 3 years. Three groups were distinguished. The RF titre became normal in 19, remained elevated in 22, became normal and subsequently again elevated in 21. Responders and non-responders to chrysotherapy occurred in all 3 groups. The findings suggest involvement of pathogenetic mechanisms related to IgM-RF, and of pathogenetic mechanisms which are not related to IgM-RF, and which may be responsive or unresponsive to chrysotherapy.

Agglutination Tests↗
PubMed1991

[Current status of drug therapy in chronic polyarthritis].

This review covers the differential indications of oral and topical non-steroidal antiinflammatory drugs, as well as oral and intra-articular corticosteroids. The so-called "disease modifying" drugs, such as chloroquine, sulfasalazine, gold compounds and penicillamine have been surpassed by low-dose pulses of methotrexate, due to its lower short-time toxicity and higher response rate. Parenteral cyclophosphamide or corticosteroid pulses should be reserved for cases with vasculitis or refractoriness to conventional drugs. Combined treatments by several "disease modifying" drugs or immunosuppressives have not yet proved their safety or higher efficacy. Selective immunosuppressives, such as cyclosporin A, have proved to be of limited efficacy but await comparison with more established drugs. Looking to the future, cytokines, e.g. interferon gamma, and monoclonal antibodies are discussed.

Anti-Inflammatory Agents↗
PubMed1983

Auranofin: dose-related risk to benefit.

Two separate, double-blind studies examined the most appropriate starting dose of auranofin, an orally administered gold compound, for the management of rheumatoid arthritis. One study indicated that neither of the two tested doses, 1 or 9 mg auranofin daily, was ideal; the 1 mg dose was insufficient therapeutically, whereas the 9 mg dose was associated with frequent lower gastrointestinal side effects. In the other study, which compared 2 and 6 mg auranofin daily, both doses resulted in similar clinical improvement and untoward effects, although the higher dose had greater efficacy sooner. Thus, it appears that 6 mg auranofin daily is the most appropriate starting dose.

Administration, Oral↗
PubMed1990

Auranofin modulated cytoplasmic free calcium in neutrophils by mobilizing intracellular calcium and inhibiting protein kinase.

The effect of the lipophilic gold compound, auranofin (AUR) on the calcium homeostasis of human neutrophils treated with or without n-formyl-methionyl-leucyl-phenylalanine (FMLP) was investigated. In agreement with previous reports, FMLP induced a rapid release of intracellular Ca2+ stores followed by a smaller influx of extracellular Ca2+. AUR and staurosporine enhanced while phorbol 12-myristate 13-acetate suppressed the secondary influx of Ca2+. Mn2(+)-quenching-of-fluorescence studies indicate that phorbol 12-myristate 13-acetate incubation blocked cation entry. AUR or staurosporine potentiation of FMLP effects on cytoplasmic free Ca2+ [( Ca2+]i) was attributed to suppression of negative feedback effects of protein kinase C. AUR (5-45 microM) per se induced a slow release of internal Ca2+ stores followed by a delayed influx of extracellular Ca2+. Control studies showed that AUR did not induce the formation of inositol 1,4,5-trisphosphate, lyse cells, or promote dye leakage. Dithiothreitol suppressed the AUR effect. AUR triggered biphasic but smaller increases in [Ca2+]i of neutrophil cytoplasts. Studies with permeabilized neutrophils showed that AUR directly released Ca2+ from internal stores. By comparison, gold sodium thiomalate, which had no effect on intact cells, also released Ca2+ from permeabilized cells. Present results indicate that AUR modulated [Ca2+]i directly by mobilized Ca2+ from multiple storage sites and indirectly by inhibiting protein kinase C.

Auranofin↗
PubMed1998

Liver toxicity profile in gold-treated Egyptian rheumatoid arthritis patients.

The objective was to evaluate the rationale for liver needle biopsy versus blood liver functional tests in monitoring the incidence of hepatotoxicity in Egyptian rheumatoid arthritic patients treated with gold compounds. Forty patients (12 males, 28 females) were randomly selected out of 258 Egyptian rheumatoid arthritic patients treated with sodium auro-thiomalate during the past 4 years. The minimum duration of treatment was 40 weeks. The methods used were firstly, liver function tests (serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, total serum bilirubin and total serum albumin) before, weekly during and after administration of sodium auro-thiomalate. Secondly, a needle liver biopsy was conducted by using the tru-cut needle. Then liver histology was graded according to Roenigk for grading liver toxicity. Viral hepatitis markers (hepatitis B surface antigen, anti-hepatitis C virus were done for monitoring viral hepatitis. Finally, the liver tissue contents of heavy metals were counted in the cases that showed grade IIIB histological changes. The results showed that none of the studied cases developed any clinically significant liver disease during the course of chrysotherapy. Blood liver function tests were of normal value throughout the course of drug administration. According to Roenigk grading, 20 patients (50%) showed grade I liver changes, and the other 20 patients showed liver changes of grades II and III (four grade II, eight grade IIIA, and another eight grade IIIB). None of the patients showed grade IV liver changes. It was concluded that blood liver tests are not the most sensitive methods to detect hepatotoxicity in gold-receiving Egyptian rheumatoid arthritic patients. Needle liver biopsy is not superior in detecting liver toxicity, compared with routine laboratory liver function tests, because of its complications. Rheumatoid arthritic patients with a potential risk of clinically significant liver disease should not be exposed to the risk of gold salt therapy. Pretreatment HLA-DR genetic typing may be a good detector for rheumatoid arthritic patients with potential risk of hepatotoxicity.

Adult↗
PubMed1986

Modulation of the release of histamine and arachidonic acid metabolites from human basophils and mast cells by auranofin.

In these experiments the effects of pharmacological concentrations of auranofin, a new absorbable gold compound, were assessed on the release of histamine and peptide leukotriene C4 (LTC4) from human basophils and lung mast cells. Auranofin, at pharmacological concentrations, inhibited in vitro histamine and LTC4 release from human basophils induced by anti-IgE. Inhibition began at about 3 X 10(-7) M and was maximum at 10(-5) M. We also evaluated the effect of auranofin on the release of histamine and LTC4 induced by anti-IgE from mast cells purified from human lung. Auranofin (3 X 10(-7) to 10(-5) M) dose-dependently inhibited the release of histamine and LTC4 from human lung mast cells. Thus pharmacological concentrations of auranofin cause dose-related inhibition of histamine release and de novo synthesis of LTC4 by human basophils and lung mast cells.

Adult↗
PubMed2004

Gold sodium thiomalate improves membrane potential impaired by high-frequency stimulation.

Effects of gold sodium thiomalate (GSTM) on membrane potential and tetanus tension were examined to elucidate whether the gold compound improves mechanical and electrical muscle dysfunction produced by continuous repeated stimulation of frog skeletal muscles. Continuous stimulation (50 Hz for 2 min, 0.05 ms pulse duration) to the sartorius muscle depolarized the membrane, decreased action potential amplitude, and prolonged action potential duration. GSTM (0.1 mM), unlike thiomalic acid (0.1 mM), markedly decreased impairment of these electrical parameters produced during the stimulation period. In the presence of 500 units/mL of catalase, fatigue stimulation still lengthened by 1.5-fold the half-duration of the action potential after a 5-min rest. The prolongation was, however, smaller than that in controls (no catalase). Application of both catalase and GSTM led to no further changes in action potential compared with the application of catalase alone. GSTM did not affect resting tension of single toe muscle fibers though it suppressed the maximum tension after continuous stimulation. These findings suggest that GSTM can inhibit excitable dysfunction of skeletal muscles subjected to continuous stimulation and that such protective effects of GSTM may be partially mediated by H2O2.

Animals↗
PubMed1988

Sodium aurothiomalate inhibits T cell responses to interleukin-2.

We studied the effects of the gold compound sodium aurothiomalate (SATM) on the responses of murine CTLL2 cells, and human T cells to Interleukin-2 (IL-2). SATM inhibited tritiated thymidine (3HTdR) incorporation by CTLL2 cells stimulated with human recombinant IL-2. Human T cells were cultured with phytohemagglutinin (PHA) in separate experiments and IL-2 receptor expression measured by using immunofluorescent anti-Tac serum; SATM inhibited IL-2 receptor expression. Furthermore, SATM when added concurrently with PHA, and IL-2 inhibited 3HTdR incorporation by human T cells in 5 day cultures. The kinetics of inhibition were further studied by adding PHA to T cells for 48 hours followed by the addition of SATM and IL-2; SATM inhibited 3HTdR incorporation even though receptor expression had occurred. These results suggest that SATM inhibits the stimulatory effects of IL-2 on T cells partly by interfering with IL-2 receptor expression, and partly by other mechanisms of action. These effects of SATM may explain some of the conflicting data in the literature on T cell responses to IL-2 in rheumatoid arthritis (RA), and suggest a possible mechanism of action for the drug in the treatment of RA.

Female↗