Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Gold Compounds”

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 559 records · Page 31Linked to original sources
PubMed1982

An electron microscopic demonstration of immune complexes of hepatitis B e-antigen using colloid gold as a marker.

Immune complexes of the hepatitis B e-antigen (HBeAg) could be labeled and thus visually identified in the electron microscope by using antibody to HBeAg (anti-HBe) tagged with colloidal gold particles. Circulating immune complexes of HBeAg were detected in sera from patients with acute hepatitis B infections as well as from asymptomatic carriers of hepatitis B surface antigens (HBsAg). Sera positive for rheumatoid factor frequently contained mixed aggregates in which immune complexes of HBsAg were closely bound to immune complexes of HBeAg.

Antibodies, Viral↗
PubMed1977

Use of microcapsules as timed-release parenteral dosage form: application as radiopharmaceutical imaging agent.

The development of a new type of parenteral dosage form is described. A system of microencapsulation was formulated which produced microcapsules containing a water-soluble core material. The basic microencapsulation system could be altered to produce microcapsules with varied timed-release characteristics. Tracer methodology was employed as a sensitive and versatile analytical tool for the development and evaluation of the microencapsulation system. The core material was labeled by neutron activation after microcapsule formulation, which eliminated the radiation hazard and contamination problems that could occur during formulation with a labeled core material. Both in vitro and in vivo testing showed that the release patterns of labeled core material could be altered and detected. The microcapsules developed have potential as a timed-release parenteral dosage form and as an organ-imaging radiopharmaceutical.

Animals↗
PubMed2001

Colocalization prostacyclin (PGI2) synthase--caveolin-1 in endothelial cells and new roles for PGI2 in angiogenesis.

In vascular cells, prostacyclin (PGI2) synthase (PGI2s) has been localized in the endoplasmic reticulum of endothelial cells and in the nuclear and plasma membrane of smooth muscle cells. In human umbilical vein endothelial (HUVE) cells, we detected the enzyme in abundant cytoplasmic vesicles apparently originating from the plasma membrane and similar to those stained by gold-albumin, which interacts with a caveolar receptor. This prompted us to try a direct confocal microscopy approach aimed at colocalizing gold-albumin, caveolin-1, and PGI2 synthase. Moreover, the staining of HUVE cells with an anti-BiP7Grp78 antibody (a marker of endoplasmic reticulum) shows a perinuclear localization, sharply separated from PGI2 synthase localization. The results indicate that more than 80% of the enzyme resides in cellular sites costaining with caveolin-1 antibody and gold-albumin. This evidence was confirmed by the demonstration that PGI2 synthase and caveolin-1 coimmunoprecipitate in HUVE cell lysates and that they are associated to detergent-insoluble membrane domains in the same low-density fractions of a sucrose gradient. In addition, depletion of cellular cholesterol by mevalonate and methyl-beta-cyclodextrin leads to the shift of PGI2 synthase and caveolin-1 to higher density fractions of the gradient. Biochemical evidence about colocalization was supported by the use of a fusion protein glutathione S-transferase (GST)/caveolin-1, which retained either PGI2s purified from ram seminal vesicles or PGI2s present in HUVE cell lysates. Binding of PGI2s to caveolin "scaffolding domain" and to C-terminal region was deduced by using full-length GST--Cav-1, GST--Cav 61--101, and GST C- and N-terminal fusion proteins. A double approach based on the usage of filipin as a specific caveolae-disrupting agent and antisense oligonucleotides targeting PGI2 synthase mRNA suggests that the production of PGI2 in caveolae is likely to be connected to the regulation of angiogenesis, at least in vitro.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Visualizing "greengold" clusters in the STEM.

"Greengold" is a large metallic cluster thought to contain 75 gold atoms in a compact 1.4-nm-diameter core surrounded by an organic shell. Scanning transmission electron microscope imaging shows uniform mass and size distributions with an apparent mass of 24 kDa, unaffected by radiation damage. The signal-to-noise ratio is adequate for visualization at low dose and in the presence of a relatively thick biological matrix. Under some conditions these clusters have a slight tendency to form linear chains and 2-D hexagonal arrays with a spacing of 2.6 nm. The parameters presented permit estimation of the feasibility of proposed labeling experiments.

Color↗
PubMed1993

A sensitive post-DAB enhancement technique for demonstration of iron in the central nervous system.

A technique is described for enhancing the reaction product of the staining reaction for iron in paraffin-embedded tissue from central nervous system (CNS). After amplification of the Prussian Blue staining reaction with 3,3'-diaminobenzidine (DAB), the reaction product was further intensified using a stepwise treatment with silver methenamine, gold chloride and uranyl nitrate (post-DAB treatment). Following the Prussian Blue-DAB staining reaction, iron was seen only in glial cells and choroid plexus epithelial cells, whereas the post-DAB treatment revealed that neurons and endothelial cells of the brain capillaries were also positively stained. The post-DAB treatment resulted additionally in an increased intensity of the reaction product within choroid plexus epithelial cells compared to that obtained in sections subjected only to the Prussian Blue-DAB reaction. The reliability of the method was evaluated using liver sections as positive controls. Furthermore the higher sensitivity of the method was assessed using nitrocellulose filters containing serially diluted iron-saturated transferrin. The post-DAB method is simple and can easily be applied to formalin- or glutaraldehyde fixed, paraffin-embedded nervous and non-nervous tissue.

3,3'-Diaminobenzidine↗
PubMed1993

Alpha-smooth-muscle actin expression in normal and fibrotic human livers.

To determine the significance of the expression of alpha-smooth-muscle actin in the fibrotic human liver, normal and diseased livers were stained with anti-alpha-smooth-muscle-actin antibody by an immunoperoxidase method. Vitamin A-containing lipocytes were also identified by the modified Kupffer's gold chloride method. In the normal human liver, lipocytes as well as vascular smooth muscle cells expressed alpha-smooth-muscle actin. In alcoholic liver disease, there was an increase in the cells positive for alpha-smooth-muscle actin adjacent to the fibrotic areas, but the response of lipocytes to the gold chloride reaction diminished. In chronic hepatitis, the cells positive for alpha-smooth-muscle actin increased around the enlarged portal areas, and the response to the gold chloride reaction did not change appreciably. An increase in the cells positive for alpha-smooth-muscle actin was associated with the progression of hepatic fibrosis in the liver of patients with alcoholic liver disease and chronic hepatitis.

Actins↗
PubMed1996

Is local biotransformation the key to understanding the pharmacological activity of salicylates and gold drugs?

It is suggested that some drugs may be converted by inflammatory cells to yield active species. The transformation may be non-enzymatic, although being driven by the enzymatic production of highly reactive species which are normal products of activated leukocytes, such as singlet oxygen, hydrogen peroxide, hypochlorite, hydroxyl radical and nitric oxide. Drugs which may be transformed in this fashion are the anti-rheumatic gold complexes which may be converted either to aurocyanide or to Au(III) complexes by myeloperoxidase in polymorphonuclear leukocytes. Salicylate may also be activated by its oxidation to dihydroxybenzoates although evidence for its transformation is weaker than for the gold complexes.

Animals↗
PubMed1998

Recovery and refining of Au by gold-cyanide ion biosorption using animal fibrous proteins.

Animal fibrous proteins (AFPs) such as egg-shell membrane (ESM), chicken feather (CF), wool, silk, or elastin are an intricate network of stable and water-insoluble fibers with high surface area and are abundant bioresources. Every AFP tested was found to accumulate gold-cyanide ion from aqueous solutions in high yield, depending on pH and some other parameters. Gold-cyanide ion is adsorbed by AFP at low pH range, with maximum binding observed at approx pH 2.0. Under the certain conditions, gold-cyanide ion was accumulated up to 8.6, 7.1, 9.8, 2.4, and 3.9% of dry weight on ESM, CF, wool, silk, and elastin, respectively. In the case of ESM, it was found that ESM removed gold-cyanide ion almost quantitatively and almost all the gold uptake by ESM was easily desorbed with 0.1 M NaOH. ESM can be used repeatedly for the process of gold adsorption-desorption. The gold-biosorptive capacity of ESM that was chemically modified with glutaraldehyde was higher than that of control. In column procedure, ESM packed on column removed gold-cyanide ion from the dilute aqueous solution to extremely low concentrations (nondetectable concentration of below 1 ppb).

Adsorption↗
PubMed1997

[Epicutaneous testing with gold salts. 2 multicenter studies of the German Contact Allergy Group].

Between 1992 and 1994 two multicentre studies were performed in order to determine the frequency of sensitization to gold salts. In the first study (1992-1993), 872 patients were tested with gold sodium thiosulfate (NTS) 0.25% in Vaseline (V), 0.5% V. and with potassium dicyanoaurate (KDC) 0.002% aqueous solution. 44 patients (5.1%) had a positive patch test reaction to gold salts: 40 (4.6%) to NTS 0.5% V., 20 (2.3%) to NTS 0.25% V. and 5 (0.6%) to KDC. A higher number of positive patch tests to gold salts was noted in patients also sensitized to another metal salt (8.5%) as compared to those who showed no other sensitivities (3.6%). In a second multicentre study (1993-1994), 135 patients with associated sensitization to metal salts or intolerance to costume [correction of custom] jewelry were tested with the same test series as in the first study and with gold sodium thiomalate (ATM) 0.25% V.17 patients (12.6%) had a positive patch test reaction to gold salts: 16 (11.8%) to NTS 0.5% V., 10 (7.4%) to NTS 0.25% V. and 5 (3.7%) to ATM. The clinical relevance of the patch test reactions was considered as being "probable" in 5 cases; 1 in the first and 4 in the second study. Considering these results, NTS 0.5% V. seems to be the most reliable allergen for detecting gold allergy. However, a high proportion of probably false-positive reactions may occur. Further studies are therefore needed to analyze if the high frequency of positive patch tests to NTS 0.5% V. are due to irritant reactions or to a weak sensitization to gold without clinical symptoms.

Adult↗
PubMed2005

Decrease in the numbers of mechanoreceptors in rabbit ACL: the effects of ageing.

It is proposed that there is a positive correlation between the numbers of mechanoreceptors and proprioceptive function. On the other hand, normal aging process is associated with deficits in proprioception. This study is designed to test the hypothesis that aging resulted in decreased numbers of mechanoreceptors. Anterior cruciate ligaments of 14 male rabbits (2 months, n=5; 12 months, n=4 and 60 months, n=5) were extracted and the total numbers of Ruffini, Pacini and Golgi tendon-like receptors were accounted. As a result, the numbers of mechanoreceptors, especially Ruffini receptors, decreased with aging (p<0.05). Increased age was associated with changes in the morphology of mechanoreceptors. In conclusion, aging results in both diminished numbers and changed morphology of mechanoreceptors.

Aging↗
PubMed2003

Amperometric biosensor with HRP immobilized on a sandwiched nano-Au / polymerized m-phenylenediamine film and ferrocene mediator.

An amperometric biosensor has been developed for the determination of H(2)O(2) in plant samples. Horseradish peroxidase (HRP) is immobilized on a sandwiched nano-Au particle / m-phenylenediamine polymer film by glutaraldehyde cross-linking. The film is formulated on the carbon paste electrode (CPE) blended with ferrocene as an electron transfer mediator. On the low concentration range, the current response is related to the H(2)O(2) concentration linearly from 0 to 8x10(-6) M with a detection limit of 1.3x10(-7) M. On a wider concentration range of 8x10(-6) to 1.4x10(-4) M, the reciprocal of current response is linearly related to the reciprocal of H(2)O(2) concentration. The apparent Michaelis-Menten constant (K(m)(app)) was calculated to be 0.0334 mM. The sensor has been tested by determining H(2)O(2) concentration in plant leaf samples.

Biosensing Techniques↗
PubMed1998

Urinary neopterin excretion and dihydropteridine reductase activity in rheumatoid arthritis.

Neopterin and biopterin are two products of the pteridine pathway. Even though their roles and interrelationships have not been exactly clarified, neopterin is known as a biomarker of cell-mediated immunity. In this case, the highly elevated neopterin levels are parallel to the slightly elevated biopterin levels. On the other hand, the reduced form of biopterin-tetrahydrobiopterin is an essential cofactor of aromatic monoxygenases that leads to synthesis of tyrosine, tryptophan and dopamine neurotransmitters and its concentration in body fluids and tissues is maintained by the enzyme dihydropteridine reductase (DHPR). Increased numbers of activated lymphocytes can be found in peripheral blood, in the synovial fluid and synovial membranes or patients with rheumatoid arthritis (RA). Since the present study was undertaken to evaluate the role of the pteridine pathway in RA, we measured urine neopterin levels and dried blood DHPR activities in 36 patients with RA and in 20 healthy volunteers, in parallel with other clinical parameters. We found that neopterin excretion was significantly increased in RA patients compared with controls. The means were 433 +/- 216, 153 +/- 43 and 111 +/- 34 mumol/mol creatinine for patients in active stage, in remission and controls, respectively. Our results suggest that urine neopterin levels were strongly dependent on the stage and activity of RA. Either as an effect of the disease itself or of drug administration, slightly reduced DHPR activities were detected (3.484 +/- 0.304 for control, 2.974 +/- 0.255 in active stage RA, and 3.048 +/- 0.302 red cytochrome C/min/5 mm disc in remission).

Adult↗
PubMed1998

Nickel and gold in skin lesions of pierced earlobes with contact dermatitis. A study using scanning electron microscopy and x-ray microanalysis.

Cases of contact dermatitis due to nickel and gold especially in pierced earlobes, are increasing in number the world over. However, the presence of these metal fragments has not been demonstrated in the skin lesions. The aim of this study was to demonstrate nickel and gold in contact dermatitis lesions in pierced earlobes. Skin specimens taken from such earlobe lesions were examined using scanning electron microscopy and x-ray microanalysis. The pierced earrings worn when the lesions appeared were examined by the same techniques, and their analysis confirmed. In nickel dermatitis, small, electron-dense fragments were seen in the specimens examined by scanning electron microscopy, and nickel was detected in locations corresponding to these fragments by x-ray microanalysis. In contact dermatitis due to gold, small dense fragments containing gold were observed. It is suggested that small fragments of nickel and gold remain in the skin lesions of pierced earlobes for a long time, even after the studs have been removed, and cause prolonged irritation and various cutaneous reactions.

Adult↗
PubMed2001

An optimized method for simultaneous demonstration of neurons and myelinated fiber tracts for delineation of individual trunco- and palliothalamic nuclei in the mammalian brain.

The truncothalamic complex has long been considered to be a nuclear group with "non-specific" projections. More recently, it is suggested that these thalamic nuclei play an important role in regulating distinct basal ganglia circuits. To further analyze the exact biological function of individual nuclei of the truncothalamic complex a simple and reliable technique for an exact delineation of distinct nuclei is desirable. Therefore, we evaluated and optimized several potential procedures for a combined visualization of neurons and myelinated fibers. Fiber staining with gold toning or immunocytochemical visualization of myelin basic protein shows high contrast and precision but precludes sufficient demonstration of neuronal cell bodies. When the most common technique for the simultaneous visualization of both structures, the Kluver-Barrera procedure, is used, demonstration of myelinated fibers is restricted when the technique is applied to cryostat or vibratome sections. In the present report this limitation was abolished. The final protocol includes lipid extraction prior to the incubation with Luxol Fast Blue and uses carefully characterized staining conditions for Luxol Fast Blue and cresyl violet rendering microscopically controlled differentiation steps unnecessary. The optimized Kluver-Barrera technique results in high precision localization of individual axons and cell bodies and thus permits an exact and simple delineation of individual nuclei in the vertebrate thalamus.

Animals↗
PubMed1996

Endocytosis and intracellular processing accompanying transfection mediated by cationic liposomes.

Cationic liposomes mediate efficient transfection of mammalian cells, but the manner in which cells internalize and process cationic liposome-DNA complexes has not been well characterized. We exposed several cell types, including human and murine erythroleukemia cells. African green monkey kidney cells (CV-1), isolated rat alveolar type II cells and alveolar macrophages to DNA-cationic liposome complexes containing N-(1-2,3-dioleyloxypropyl)-N,N,N-triethylammonium (DOTMA) and Dioleylphosphatidylethanolamine (DOPE). The morphology of liposome-cell interactions was assessed by electron microscopy. Liposome preparations were complexed to colloidal gold particles or to both plasmid DNA and gold particles. Cells treated with DOTMA liposome-DNA complexes demonstrated endocytosis of the liposome-DNA complexes in coated pits, which were seen in early endosomes, late endosomes, and lysosomes. In isolated alveolar type II cells, the gold-labelled DOTMA lipid apparently mixed with the contents of lamellar bodies. In most cells, gold particles were dispersed throughout the cytoplasmic matrix. In a small proportion of CV-1 and U937 cells, a membrane system resembling the endoplasmic reticulum developed within the nucleus. This novel structure was also present in nuclei after they were isolated from CV-1 cells and then mixed with DOTMA-containing liposomes. Membranes which form after exposure to DOTMA-containing liposomes were 10 nm in thickness as compared to the approx. 8 nm thickness of endogenous cellular membranes. Based on these morphologic observations, we propose that the main route of entry of cationic liposomes into cells is by endocytosis. In some instances, the endosomal compartment releases its cationic liposome-DNA contents into the cytoplasmic matrix. Occasionally, liposomes may enter the nucleus by fusion with the nuclear envelope, creating vesicular and reticular intranuclear membranes. It is not clear at present which, if any of these morphological observations correlates with transfection mediated by cationic liposomes.

Animals↗
PubMed1979

The reaction of cow beta-lactoglobulin with tetracyanoaurate(III).

The reaction of cow beta-lactoglobulin with Au(CN)-4 is shown to label the free sulphydryl group on the protein by a reductive mechanism yielding a stable complex. High salt concentrations are shown to affect the pH-dependent conformational transition (N in equilibrium R yields S). It is hoped that Au(CN)-4 may be of more widespread use as a specific heavy-atom label for the isomorphous replacement method.

Animals↗
PubMed1990

The activation of gold complexes by cyanide produced by polymorphonuclear leukocytes--I. The effects of aurocyanide on the oxidative burst of polymorphonuclear leukocytes.

It has been suggested that the antiarthritic gold complex, aurothiomalate (Autm), is activated by its conversion to aurocyanide by polymorphonuclear leukocytes (PMN) which generate cyanide from thiocyanate. In an examination of this hypothesis, a study has been conducted on the effects of aurocyanide on the oxidative burst of polymorphonuclear leukocytes (PMN) and monocytes activated by phorbol myristate acetate (PMA). Aurocyanide produced delayed inhibition of the oxidative burst as shown by its effect on both lucigenin and luminol-dependent chemiluminescence and on the production of superoxide. It was a more potent inhibitor of luminol-dependent chemiluminescence than free thiomalate and other by-products of the reaction between Autm and cyanide. Aurocyanide had a biphasic effect on the PMA-stimulated hexose monophosphate shunt of PMN, with enhancement at 0.1 microM and inhibition at 10 and 100 microM. The activity of aurocyanide was also compared with that of auranofin, an orally active gold complex, which inhibits a variety of functions of PMN and monocytes. At low concentrations, auranofin produced delayed inhibition of chemiluminescence in a similar fashion to aurocyanide but at high concentrations was an immediate inhibitor of the oxidative burst.

Auranofin↗