Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GOLD”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2000

Exposure to metallic gold in patients with contact allergy to gold sodium thiosulfate.

Gold allergy is common, with approximately 10% of patients patch tested because of eczematous disease being positive to gold sodium thiosulfate (GSTS). However, clinical relevance seems to be rare. The aim of this prospective double-blind study was to demonstrate the effects of exposure to metallic gold, in this case earrings, in gold-positive patients. 60 female patients with pierced earlobes test-positive to GSTS were included in the study. The patients were randomized into 2 groups, 30 patients receiving earrings with a surface layer consisting of 24-carat gold and 30 patients earrings with a surface layer of titanium nitride, virtually indistinguishable from gold. The patients wore the earrings for 8 weeks. During the study, any dermatitis on the earlobes, as well as on other body sites, was registered. The skin reactions observed were weak but, in total, 17 of the 60 patients had a skin reaction (local or remote) during the study, 12 of whom had received gold earrings and 5 titanium (p<0.05). 11 patients had a reaction on the earlobes, 7 of whom had received gold earrings and 4 titanium (NS). With these facts it is hard to exclude that exposure to gold jewelry can be clinically relevant in persons hypersensitive to gold.

Adult↗
PubMed1985

Skin contact with gold and gold alloys.

3 types of reaction to gold merit discussion. First, there is the effect known as black dermographism, in which stroking with certain metals immediately produces well-defined black lines on the skin. Some gold alloys are amongst such metals. The evidence indicates that the effect is the result of impregnation of the skin with black metallic particles generated by mechanical abrasion of the metal by contaminants of the skin. There is no positive and unequivocal evidence of the ability of metals to mark uncontaminated skin so rapidly that it is possible to write upon it. Secondly there are the 2 related phenomena of the wear of gold jewelry, and the susceptibility to certain individuals to blackening of the skin where it is in contact with such jewelry. The occurrence of smudge, as it is often called, is not very common, but is brought to the attention of most jewelers from time to time. In extreme cases it may make it embarrassing for the person concerned to wear metallic jewelry. It would appear as if gold smudge also results mainly from mechanical abrasion of jewelry, though this may be aided and/or supplemented in some instances by corrosion of gold or gold alloy induced by certain components of the sweat. Finally, there is the question of true allergic responses to contact of the skin with gold and its alloys. Judging from the very few cases which have been recorded, such responses are extremely rare. Some recent observations on the reactions of metallic gold with amino acids and of reaction to contact of the skin with gold on the part of rheumatoid arthritis patients undergoing gold therapy, are, however, relevant in this connection.

Corrosion↗
PubMedDate not supplied

Interaction of D-penicillamine with gold salts: in vivo studies on gold chelation and in vitro studies on protein binding.

Serum and urinary gold levels were monitored in 18 patients previously treated with gold salts for rheumatoid arthritis and the effects of D-penicillamine studied. There was no statistically significant change in urinary gold levels on D-penicillamine therapy although there were some individual variations. Serum gold levels fell during D-penicillamine therapy but the rates of fall did not differ from those seen in patients not treated. In vitro studies on protein binding of gold salts suggest that a high affinity exists between gold salts and albumin with low levels of unbound gold even at concentrations far exceeding those seen in vivo. These preliminary results suggest that at therapeutic levels only small amounts of gold are available for chelation by penicillamine. It is concluded that penicillamine at low dosage is an unreliable chelator of gold salts in vivo and its use in the management of gold toxicity remains speculative.

Arthritis, Rheumatoid↗
PubMed1991

Ultrastructural localization of gold particles within neural grafts labeled with gold-filled Sendai viral envelopes.

The ability to discriminate between host and donor cells is required to interpret the organization of neural grafts at the electron microscopic (EM) level. Using light microscopy, Ardizzoni et al. (Ardizzoni, S.C., Michaels A., and Arendash, G.W. [1988] Science 239:635-637) described a method, using gold-filled Sendai viral envelopes, for labeling cell suspensions prior to grafting. As the colloidal gold used in this procedure is especially attractive for use with EM, we have examined the ultrastructural distribution and character of this label with transplanted cells. Cell suspensions taken from the nucleus basalis of fetal rats were labeled using gold-filled Sendai viral envelopes and grafted into the dorsal neocortex of adult host rats with nucleus basalis lesions. After varying survival times ranging from 1 to 14 months, grafts and surrounding host tissue were examined using standard EM techniques. Within the graft site, gold particles ranging from 10-200 nm were found associated with various membranes throughout the cytoplasm of both neurons and glia. Gold particles of similar size were also found within the nuclei of neuronal and non-neuronal cells. Host cells near the graft site contained some small gold particles (10-40 nm). Control injections of non-viable, gold-labeled cells or colloidal gold alone resulted in similar patterns of small gold particles which were readily discriminable from the larger virally inserted gold particles found in viable labeled donor cells. We conclude that this method allows discrimination between closely associated host and donor cells.

Animals↗
PubMed2000

Increased risk of restenosis after placement of gold-coated stents: results of a randomized trial comparing gold-coated with uncoated steel stents in patients with coronary artery disease.

BACKGROUND: Gold is a highly biocompatible material. Experimental evidence suggests that coating the stent with a gold layer may have a beneficial influence. In this randomized trial, we assessed whether gold-coated stents were associated with a better clinical and angiographic outcome after coronary placement. METHODS AND RESULTS: Patients with symptomatic coronary artery disease were randomly assigned to receive either a gold-coated Inflow stent (n = 367) or an uncoated Inflow stainless steel stent (n = 364) of identical design. Follow-up angiography was routinely performed at 6 months. The primary end point of the study was the occurrence of any adverse clinical event (death, myocardial infarction, or target-vessel revascularization) during the first year after stenting. At 30 days, there was no significant difference in the combined incidence of adverse events, with 7.9% in the gold-stent group versus 5.8% in the steel-stent group (P = 0.25). The incidence of angiographic restenosis (> or =50% diameter stenosis) was 49.7% in the gold-stent group and 38.1% in the steel-stent group (P = 0.003). One-year survival free of myocardial infarction was 88.6% in the gold-stent group and 91.8% in the steel-stent group (P = 0.14). One-year event-free survival was significantly less favorable in the gold-stent group (62.9% versus 73.9% in the steel-stent group; P = 0.001). CONCLUSIONS: Coating steel stents with gold had no significant influence on the thrombotic events observed during the first 30 days after the intervention. However, gold-coated stents were associated with a considerable increase in the risk of restenosis over the first year after stenting.

Aged↗
PubMed1992

Gold-specific T cells in rheumatoid arthritis patients treated with gold.

Gold-specific T lymphocyte clones were isolated from a patient with rheumatoid arthritis who developed delayed type hypersensitivity reactions to gold. All of the isolated T cell clones required histocompatible antigen presenting cells as well as gold for induction of proliferation. Using a panel of HLA-homozygous Epstein Barr virus-transformed B (EBV-B) cells and anti-HLA antibodies, the clones were shown to recognize gold in the context of DR1 molecules. Gold recognition did not require active antigen processing since specific proliferation was not affected by glutaraldehyde fixation of the DR1 homozygous antigen presenting cells. Furthermore, we could show that gold salts inhibited peptide-induced responses of a peptide-specific T cell clone. In addition to providing evidence for gold-specific T cells in gold-treated RA patients exhibiting delayed type hypersensitivity responses, these data suggest that gold can alter MHC-peptide complexes. The latter observation may in part explain the mechanism/s responsible for both the therapeutic and the toxic effects of gold.

Antigen-Presenting Cells↗
PubMed1997

Contact allergy to gold and gold therapy in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis were investigated for contact allergy to gold in connection with treatment with gold preparations. There were 57 patients with rheumatoid arthritis previously treated with gold, with or without cutaneous side-effects, as well as 20 patients intended for such treatment; all were exposed to patch and intradermal tests with gold sodium thiosulfate, gold sodium thiomalate and auranofin. Contact allergy to gold was demonstrated in 8 out of 77 patients (10.4%). In the retrospective material, gold allergy was found in 1.8%, in the prospective material in 35.0%. Contact allergy to gold is very frequent among patients with rheumatoid arthritis before gold therapy. In order to avoid early hypersensitivity reactions skin tests should be carried out before gold therapy is instituted.

Adolescent↗
PubMed2002

Increased sensitivity of surface plasmon resonance of gold nanoshells compared to that of gold solid colloids in response to environmental changes.

Gold nanoshells have been synthesized by reacting aqueous HAuCl4 solutions with solid templates such as silver nanoparticles. The morphology, void space, and wall thickness of these hollow nanostructures were all determined by the templates, which were completely converted into soluble species during the replacement reaction. The surface plasmon peaks of these gold nanoshells were considerably red-shifted as compared to gold solid colloids having approximately the same dimensions. In addition, the surface plasmon resonance of gold nanoshells exhibited a much more sensitive response toward environmental changes even when compared with solid colloids with a mean size much smaller than that of gold nanoshells. For example, the sensitivity factor (i.e., the shift in peak position per unit change in the refractive index of the surrounding medium) was 408.8, 60.0, and 70.9 nm per refractive index unit for gold nanoshells with a mean diameter of 50 nm and wall thickness of 4.5 nm, gold solid colloids of 50 nm in diameter, and gold solid colloids of 30 nm in diameter, respectively. The formation of alkanethiolate self-assembled monolayers on their surfaces caused the plasmon peaks to red-shift by 3.0 nm per methylene unit for gold nanoshells and 0.2 nm per methylene unit for solid colloids with a mean size of 50 nm. Such enhanced sensitivities should make gold nanoshells particularly useful as optical probes for chemical or biological binding events at solid-liquid interfaces.

Journal Article↗
PubMed2006

Formation of gold@polymer core-shell particles and gold particle clusters on a template of thermoresponsive and pH-responsive coordination triblock copolymer.

Template synthesis of various morphological gold colloidal nanoparticles using a thermoresponsive and pH-responsive coordination triblock copolymer of poly(ethylene glycol)-b-poly(4-vinylpyridine)-b-poly(N-isopropylacrylamide) is studied. The template morphology of the thermoresponsive and pH-responsive coordination triblock copolymer, which can be tuned by simply changing the pH or temperature of the triblock copolymer aqueous solution, ranges from single chains to core-corona micelles and further to micellar clusters. Various morphological gold colloidal nanoparticles such as discrete gold nanoparticles, gold@polymer core-shell nanoparticles, and gold nanoparticle clusters are synthesized on the corresponding template of the triblock copolymer by first coordination with gold ions and then reduction by NaBH4. All three resultant gold colloidal nanoparticles are stable in aqueous solution, and their sizes are 2, 10, and 7 nm, respectively. The gold@polymer core-shell nanoparticles are thermoresponsive. The gold nanoparticle cluster has a novel structure, and each one holds about 40 single gold nanoparticles.

Journal Article↗
PubMed2006

Mechanisms of gold bioaccumulation by filamentous cyanobacteria from gold(III)-chloride complex.

The mechanisms of gold bioaccumulation by cyanobacteria (Plectonema boryanum UTEX 485) from gold(III)-chloride solutions have been studied at three gold concentrations (0.8,1.7, and 7.6 mM) at 25 degrees C, using both fixed-time laboratory and real-time synchrotron radiation absorption spectroscopy (XAS) experiments. Interaction of cyanobacteria with aqueous gold(III)-chloride initially promoted the precipitation of nanoparticles of amorphous gold(I)-sulfide at the cell walls, and finally deposited metallic gold in the form of octahedral (111) platelets (approximately 10 nm to 6 microm) near cell surfaces and in solutions. The XAS results confirm that the reduction mechanism of gold(III)-chloride to metallic gold by cyanobacteria involves the formation of an intermediate Au(I) species, gold(I)-sulfide.

Cyanobacteria↗
PubMed1985

Gold concentrations and toxicity during oral gold treatment with auranofin.

The concentrations of gold in whole blood, serum, urine and blood cells of patients with rheumatoid arthritis were measured during 6 months of oral treatment either with Auranofin or placebo. Any adverse effects attributable to the treatments were also recorded. Although the time course of gold during Auranofin therapy was similar to that of injected gold, the blood and serum gold concentrations were significantly lower than those measured in patients receiving injected gold. Between 45 and 58% of Auranofin gold in the blood was associated with blood cells. In comparison, following injections of gold thiomalate, only about 4% of the gold was present in the blood cells. During the 6-month period, 2 patients receiving Auranofin withdrew because of diarrhoea and another because of rash. 1 placebo patient withdrew because of headaches. No laboratory evidence of haematological, renal or hepatic abnormality was encountered. It is suggested that the markedly lower concentrations of gold in the body sustained during treatment with Auranofin may be the critical factor towards a greater tolerance of the drug in the treatment of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Distribution of gold in serum erythrocytes and white blood cells after in vitro incubation and during chrysotherapy with different gold compounds.

We examined the binding of gold to serum proteins and the gold level in serum and in blood cells both after incubation in vitro and under longterm treatment with 3 gold compounds. Gold was measured by atomic absorption spectrophotometry, a serum fractionated by gel chromatography; blood cells were separated by gradient centrifugation, and intracellular gold was measured after pressure decomposition and MIBK-extraction. Aurothiomalate (GSTM), gold keratinate (GK), and auranofin (AF) were used. AF showed the highest binding to globulins in in vitro and in vivo. With GSTM and GK there were no measurable amounts of gold in the red cell lysate or erythrocyte membranes whereas with AF 40% of gold was localized within erythrocytes. The amount of gold in granulocytes and mononuclear cells after incubation with AF is considerably higher than with GK and GSTM.

Auranofin↗
PubMed1994

[Contact allergy to gold and its alloys. Pertinence of gold salt patch tests].

Allergic contact dermatitis to gold and its alloys is a rare affection and it is difficult to interpret gold salts patch tests. We report two cases of patients with positive patch tests to 0.5% sodium aurothiosulfate discovered during a dermatology exploration of an occupational contact eczema (for the first patient) and an intolerance to gold jewelry (for the second). There is much confusion in the literature concerning the allergologic exploration of contact dermatitis to gold: no standardized test, possible cross reactions between different gold salts, the tests often irritate. The mechanism of sensitization to gold salts is unknown since pure gold is inalterable and does not contain any salts. The pertinence of a positive test to one or more gold salts must therefore be examined carefully and the diagnosis of gold allergy must not be made without sufficient evidence.

Adult↗
PubMed1994

High frequency of contact allergy to gold sodium thiosulfate. An indication of gold allergy?

When gold sodium thiosulfate was added to the patch test standard series, positive reactions were obtained in 8.6% of 823 consecutive patients with suspect contact allergy. The test reactions were clinically of an allergic type and, in several cases, long-lasting. There was no correlation with other allergens in the standard series. In a special study on 38 patients with contact allergy to gold sodium thiosulfate, the following principal findings were obtained: positive patch tests to the compound itself in dilute concentration; positive patch tests to potassium dicyanoaurate; negative patch tests to gold sodium thiomalate, sodium thiosulfate, and metallic gold; positive intradermal tests to gold sodium thiosulfate. Our findings make gold sodium thiosulfate the 2nd most common contact allergen after nickel sulfate. It is suggested that a positive skin test to gold sodium thiosulfate represents gold allergy.

Adult↗
PubMed2005

Gold and gold-palladium coated polypropylene grafts in a S. epidermidis wound infection model.

BACKGROUND: The use of non-absorbable mesh grafts in both abdominal wall defects and inguinal hernias are impossible in the presence of contamination. This study was conducted for evaluation of the efficiencies of polypropylene mesh grafts coated with gold and palladium-gold. MATERIALS AND METHODS: Ten piece of 1 x 2 cm of polypropylene mesh grafts were used in each group of naïve, gold-coated, and palladium-gold-coated. The grafts were incubated in physiological saline buffered and 0.5 McFarland slime positive Staphylococcus epidermidis for 24 h. At intervals of 6, 12, 24, 48, 72 h grafts were washed with saline and vortexed for 2 min in 2 ml of physiological saline. There were 100 microl of samples of vortexed material incubated in blood agar and 24 h later, colony numbers were assessed. In the second part of study, the grafts were implanted below the musculoaponeurotic layer at inguinal region of rats following the same procedure of incubation and washing. On the 8th day, the rats were examined for infection rate and their wound cultures were obtained. RESULTS: The least amount of bacterial growth was detected in the samples obtained from gold-palladium coated grafts; whereas the highest rate of growth was found in samples of naive grafts. The superficial surgical site infection rate was 0% in gold-palladium coated, 30% in gold-coated and 100% in naïve polypropylene group. The bacterial growth rate from wound cultures confirmed the superficial surgical site infection rates in all groups. CONCLUSION: Prosthetic graft infection with S. epidermidis can be prevented by coating the graft with gold-palladium or gold.

Abdominal Wall↗
PubMed2006

Gold and gold-iron oxide magnetic glyconanoparticles: synthesis, characterization and magnetic properties.

The preparation, characterization and the magnetic properties of gold and gold-iron oxide glyconanoparticles (GNPs) are described. Glyconanoparticles were prepared in a single step procedure in the presence of aqueous solution of thiol functionalized neoglycoconjugates and either gold salts or both gold and iron salts. Neoglycoconjugates of lactose and maltose disaccharides with different linkers were used. Iron-free gold or gold-iron oxide GNPs with controlled gold-iron ratios were obtained. The average core-size diameters are in the range of 1.5-2.5 nm. The GNPs are fully characterized by (1)H NMR spectrometry, transmission electron microscopy (TEM), and UV-vis and X-ray absorption (XAS) spectroscopies. Inductive plasma-atomic emission spectrometry (ICP) and elemental analysis gave the average number of neoglycoconjugates per cluster. The magnetic properties were measured in a SQUID magnetometer. The most remarkable results was the observation of a permanent magnetism up to room temperature in the iron-free gold GNPs, that was not present in the corresponding gold-iron oxide GNPs.

Ferric Compounds↗
PubMed1989

[A study on the inhibition of non-specific neutral proteinase by gold salt. Part 1. Gold sodium thiomalate].

The inhibitory effect of gold sodium thiomalate on non-specific neutral proteinase (EC 3.4.24.4) was investigated in vitro, in order to clarify the suppressive mechanism of the inflammatory process of joints by gold salt. The neutral proteinase was inhibited time- and concentration-dependently by gold salt. When the enzyme was incubated with 1 x 10(-2)M gold sodium thiomalate for 60 minutes, almost 100% of the activity was lost. Even at a lower concentration (1 x 10(-5)M, gold sodium thiomalate inhibited the enzyme time-dependently after longer incubation (3 or 9 hours). However, the same concentration of gold sodium thiomalate previously incubated with alpha-casein did not inhibit it. The results obtained here suggest that gold sodium thiomalate may inhibit the enzyme by binding it. The delay of neutral proteinase inhibition by gold sodium thiomalate seemed to be dependent on the concentration of gold salt.

Antirheumatic Agents↗
PubMed1987

Ultrastructural localization of mannoside residues on tissue sections: comparative evaluation of the enzyme-gold and the lectin-gold approaches.

Mannoside residues were revealed at the ultrastructural level in different cellular and extracellular compartments by means of the enzyme-gold and the lectin-gold approaches. For the enzyme-gold technique, an alpha-mannosidase-gold complex was prepared and conditions for the preparation of this complex as well as for its application were determined. Labeling was found over the rough endoplasmic reticulum mainly at the level of the membranes, the lumen of the cisternae being devoid of labeling. In the nucleus, the dense chromatin and the edge of the fibrillar threads in the nucleolus were intensely labeled. Few gold particles were present over the Golgi apparatus and mitochondria. The secretory granules in pancreatic cells, the peroxisomes in liver and the mucin in duodenal goblet cells were devoid of labeling. In the extracellular space, the basal lamina was labeled. Over the glomerular basal lamina, the labeling was mainly towards the epithelial side, in close contact with the podocytes. The results with the concanavalin A horseradish peroxidase (Con A-HRP)-gold technique were similar to those found with the enzyme-gold approach. Some differences were, however, detected at the level of the rough endoplasmic reticulum and the nucleus. In the endoplasmic reticulum, Con A-HRP-gold labeling was present over both the membranes and the lumen of the cisternae. In the nucleus, the labeling was mainly over the dispersed chromatin. These differences may be due to the binding of Con A not only to mannoside but also to other sugar residues as well as to the affinity of HRP-gold for some nucleoplasmic components.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗