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PubMed1984

Silver staining, immunofluorescence, and immunoelectron microscopic localization of nucleolar phosphoproteins B23 and C23.

Nucleolar organizer region (NOR)-specific silver staining and immunolocalization of nucleolar phosphoproteins B23 and C23 were compared in Novikoff hepatoma ascites cells. Silver staining and protein C23 immunostaining were both localized in the fibrillar shell surrounding the fibrillar center and in the fibrillar center. During mitosis, silver staining and protein C23 were localized at the NORs. Therefore, protein C23 and the silver-staining protein both seem to be associated with rDNA-containing structures (Mirre and Stahl 1981). A comparison of toluidine blue staining specific for RNA and B23 immunostaining demonstrated that protein B23 was associated with RNA-containing regions of the nucleolus and was absent from the fibrillar centers. Localization of these proteins and their functions are discussed in relation to the organization of the nucleolus.

Animals↗
PubMed1984

Silver staining the chromosome scaffold.

Cytological silver-staining procedures reveal the presence of a "core" running along the chromatid axes of isolated HeLa mitotic chromosomes. In this communication we examine the relationship between this "core" and the nonhistone chromosome scaffolding, isolated and characterized in previous publications from this laboratory. When chromosomes on coverslips were subjected to the steps used for scaffold isolation in vitro and subsequently stained with silver, the characteristic "core" staining was unaffected. Control experiments suggested that the "core" does not contain large amounts of DNA. When scaffolds were isolated in vitro, centrifuged onto electron microscope grids, and stained with silver, they were found to stain selectively under conditions where specific "core" staining was observed in intact chromosomes. These results suggest that the nonhistone scaffolding is the principal target of the silver stain in chromosomes.

Chromosomes↗
PubMed1985

Investigation of immunogold-silver staining by electron microscopy.

Deposition of metallic silver on colloidal gold immunoreagents has been shown to be a very sensitive immunostaining technique capable of detecting low levels of immunoreactivity in tissue sections. Using electron microscopy we have shown that immunolabelling is highest with small sizes of gold which can penetrate sections better and achieve higher densities of particles in the section than larger particles. Chemical permeabilisation of the embedding medium aids the penetration of colloidal gold. The silver enhancement step in immunogold-silver staining was shown to be progressive, allowing optimisation of staining and the selection of the final size of silver deposits required. Some poorly understood features of the technique are rationalised and the additional knowledge gained will aid the wider application of this method.

Animals↗
PubMed1985

Increased sensitivity in immunocytochemistry. Effects of double application of antibodies and of silver intensification on immunogold and peroxidase-antiperoxidase staining techniques.

Sensitivity and detection efficiency of immunocytochemical methods were tested on cytochemical models and tissue material, respectively. Use of silver intensification procedures revealed that staining with immunogold reagents could be rendered equally or even more sensitive than the standard peroxidase-antiperoxidase (PAP) method. Further increases in sensitivity with both methods could be obtained by double application of the primary antiserum. Combined use of the immunogold techniques and the PAP method with development in diaminobenzidine and subsequent silver intensification resulted in the most sensitive procedures. The procedures were applied to a wide variety of tissue preparations, including whole mount preparations of the external longitudinal muscle layer of the gut wall and were found not to produce any unspecific staining in any tissue tested. Use of immunogold-silver and, particularly of the combined immunogold-silver-PAP methods may be valuable for analyzing tissues and tumours containing small amounts of antigen, for testing the quality of immunogold staining procedures intended for ultrastructural studies and for electroblotting techniques.

Animals↗
PubMed1989

A silver-reducing component in rat striated muscle. II. Isolated sarcoplasmic reticulum vesicles.

In previous work on rat striated muscle cells a silver-reducing component was found selectively localized at the terminal cistern/transverse tubule system (Tandler and Pellegrino de Iraldi 1989). To further investigate that problem we performed the Hg-Ag argentaffin reaction on a sarcoplasmic reticulum fraction from rat skeletal muscle. Circular profiles corresponding to vesicular structures were found outlined by silver grains. The number of silver "stained" vesicles were less than the total number vesicles stained by conventional procedures. The correlation between argentaffinities in the intact muscle fiber and their subcellular organelles indicated that the Hg-Ag reactive vesicles must be those derived from the terminal cisternae of the sarcoplasmic reticulum. The silver-reducing constituent aggregates in the presence of 1 mM CaCl2 or 0.5 M K cacodylate. The state of aggregation induced by Ca2+ was not affected by incubation with 0.5% Triton X-100 or by 2 mM EDTA, thus suggesting a localization at or near the membrane of the terminal cistern vesicle facing the junctional gap. In Laemmli SDS-acrylamide gels the Hg-Ag reaction stained all proteins in a manner similar to Coomasie blue. It is suggested that the selective histochemical staining is the result of differential reactivities due to steric requirements of the chemical reaction.

Animals↗
PubMed1984

Energy dispersive X-ray analysis of tissue gold after silver amplification by physical development.

Rats were treated intraperitoneally with the gold-containing compounds sodium aurothiomalate (Myocrisin), sodium aurothiosulfate (Sanocrysin), and aurothioglucose. Using stem energy dispersive X-ray analysis, gold and silver were shown to be located at the same point in lysosomes of proximal tubular cells of the kidney, in hepatocytes and in macrophages of lymph glands, spleen and liver. This result indicates that, after exposure to ultraviolet radiation, chemically bound tissue gold is transformed to metallic gold that subsequently can catalyze the reduction of silver ions to silver when subjected to physical development, i.e. exposed to a photographic developer containing silver ions in addition to the reducing molecules.

Animals↗
PubMed1990

Silver stains for identification of neuroendocrine cells. A study of the chemical background.

The chemical background of silver stains used for visualization and characterization of peripheral neuroendocrine cells in the gastrointestinal tract and pancreas, and of their corresponding tumours, was studied in tissue sections and by a dot-blot technique. Sequential staining of pancreatic islets with an immunohistochemical procedure and silver staining of the same tissue section revealed that chromogranin A immunostained cells also displayed an argyrophil reaction with the Grimelius method, but no argentaffin reaction with the Masson technique. Accordingly, purified chromogranin A (15 micrograms or less) treated in formalin and applied to nitrocellulose did not show any argentaffin reaction but displayed a dose-related argyrophil reaction. Equal quantities of other polypeptide components did not give rise to any silver reaction. Further dot-blot studies showed that the tryptophan and tyrosine metabolites, dopamine, norepinephrine, 5-hydroxytryptamine and 5-hydroxinodole caused strongly argentaffin and argyrophil reactions while epinephrine, 5-hydroxyindole-3-acetic acid and 5-hydroxytryptophan gave only the former reaction. Among other chemical components studied, only guanine displayed weak silver staining. The results indicate that the reaction products between aldehydes and the granular content of biogenic amines synthesized from tryptophan and tyrosine display an argentaffin reaction and that the granular chromogranin A caused an argyrophil but no argentaffin reaction.

Animals↗
PubMed1991

Double lectin and immunolabelling for transmission electron microscopy: pre- and post-embedding application using the biotin-streptavidin system and colloidal gold-silver staining.

Pre- and post-embedding methods are described that can be used for consecutive localization of two intracellular cytoplasmic binding sites in cells and tissues embedded in acrylic plastic for transmission electron microscopy. Both applications make use of the biotin-streptavidin system with colloidal gold detector particles and involve silver staining of the first gold signal to a predetermined size. Silver augmentation effectively masked any free binding sites on the biotinylated molecule and on the streptavidin complex of the first labelling reaction, thereby allowing a second cycle with the same detection system. Excellent ultrastructural localization was obtained with silver lactate as the silver ion donor in the developing solution, and the enhancement treatment did not destroy or even visibly reduce target site reactivity for the subsequently applied probe. Using these methods it was possible to achieve specific double lectin and immunological labelling; they could, however, be adapted to dual or multiple-labelling procedures with any biotinylated molecules.

Animals↗
PubMed1982

Microcomputer-controlled determination of dissociation constants of sulfanilamides and stability constants of the related silver complexes.

As a contribution to the structure-activity relationship of silver sulfanilamide complexes, the pKa-values of thirteen sulfanilamides and the log K-values of their related silver compounds were determined using a microcomputer-controlled titrator which determines the silver ion concentration and hydrogen ion concentration in a combined measurement. Predictions on antibacterial effectiveness and the risk of sensitization reactions of some of the investigated silver sulfanilamides are made on the basis of the conditional stability constants computed from the pKa- and log K-values at pH = 7.4.

Chemical Phenomena↗
PubMed1999

Silver catheter study: methods and results of microbiological investigations.

Within the framework of the clinical study of the Erlangen silver catheter 104 silver catheters and 105 control catheters were tested by microbiological culture. This was done by rolling the catheter on a blood agar plate, washing the lumen through with tryptic soy broth (TSB) and, after ultrasound treatment, incubating the catheter tip in TSB as an enrichment culture for detecting very low bacterial counts. There was good agreement in the numbers of colony-forming units (CFU) detected by the roll plate and luminal washout cultures in 92% of the silver and 89% of the control catheters tested. Seventy-six (73%) of the 104 silver catheters showed no bacterial growth and 16 (15%) showed very low bacteria counts (< 15 CFU), or growth only after enrichment, which were attributed in both instances to catheter contamination. Twelve catheter tips (12%) showed significant bacterial counts greater than 15 CFU which were indicative of colonization or catheter-related infection. Corresponding results in the control catheters were 59 (56%), 28 (27%) and 18 (17%), respectively, a higher rate of infection or contamination which was statistically significant (chi-square test: P = 0.04).

Catheters, Indwelling↗
PubMed1996

Analysis of triacylglycerols by silver-ion high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

Triacylglycerols of the seed oils rich in alpha- and/or gamma-linolenic acid moieties were separated by silver-ion high-performance liquid chromatography (HPLC) followed by on-line atmospheric pressure chemical ionization-mass spectrometric (APCI-MS) detection. Mass spectra of most triacylglycerols exhibited abundant [M + H]+ and [M - RCO2]+ ions, which defined the molecular weight and the molecular association of fatty acyl residues of a triacylglycerol, respectively. Silver ions formed weaker complexes with triacylglycerols containing gamma-linolenic acid than with those containing alpha-linolenic acid, i.e., the elution order of molecules was XYT gamma > XYT alpha, XT gamma T gamma > XT gamma T alpha > XT alpha T alpha, and T gamma T gamma T gamma > T gamma T gamma T alpha > T gamma T alpha T alpha > T alpha T alpha T alpha, where T alpha = alpha-linolenic acid, T gamma = gamma-linolenic acid, and X, Y = fatty acids different from linolenic acid. Furthermore, silver-ion HPLC resulted in partial separation within equally unsaturated triacylglycerols according to differences in the combined number of acyl carbons. Regioisomeric forms of triacylglycerols were not determined from the seed oil samples, although differences were measured with reference compounds in the relative abundances of [M - RCO2]+ ions formed by a loss of a fatty acyl residue from the sn-2 position and the sn-1/3 positions. Silver-ion HPLC/APCI-MS provided valuable information for structure elucidation of seed oil triacylglycerols: 43 molecular species were identified from cloudberry seed oil, 39 from evening primrose oil, 79 from borage oil, 44 from alpine currant, and 56 from black currant seed oils. The quantitation requires to be studied further, especially in those cases where several molecular weight species of triacylglycerols eluted in a single chromatographic peak.

Chromatography, High Pressure Liquid↗
PubMed1989

Susceptibility of multidrug-resistant isolates of Klebsiella pneumoniae to silver nitrate.

Multidrug-resistant (MDR) clinical isolates of Klebsiella pneumoniae were checked for their sensitivity toward silver nitrate by the tube-dilution method. Nearly 75% of MDR strains could be successfully inhibited by 5 mg/L of silver nitrate. A significant correlation was observed between incidence of silver and trimoxazole resistance and silver and kanamycin resistance in these isolates. The genetic linkage of these two properties could not be proved since simultaneous curing and co-transfer studies gave negative results.

Drug Resistance, Microbial↗
PubMed2001

[Association of silver granules with elastic fibers in amalgam reaction of mouth mucosa].

OBJECTIVE: Discoloration of the oral mucosa due to amalgam may appear histologically merely as brown pigmentation of the fibrous extracellular matrix. It was the aim of these investigations to identify the fibrous component that contains silver granules. METHODS: Biopsy specimens from seven patients with clinically diagnosed amalgam tattoos were investigated by light and electron microscopy as well as by X-ray microanalysis. RESULTS: Light microscopy revealed small brown discolored fibers in all specimens; in sections stained with Weigert's resorcinfuchsin, they appeared dark violet. Scanning electron microscopy revealed metallic granules associated with thin fibers; by X-ray microanalysis, they exhibited preferentially peaks for silver and sulfur. Transmission electron microscopy detected only electron-dense particles in elastic fibers. CONCLUSIONS: With the different morphological methods, silver granules of amalgam tattoos were exclusively detected within elastic fibers. This result indicates that granular brown discoloration of the matrix fibrils is due to silver impregnation of elastic fibers. Therefore, the histopathological diagnosis of amalgam tattoo is possible even in the absence of larger amalgam particles with black appearance.

Biopsy↗
PubMed2000

Digestion method for silver accumulated in micro-organisms.

Silver is accumulated to high concentrations in certain microbial strains. Here a bomb digestion method is proposed, using HNO3 and HCl, for the extraction and digestion of silver and silver compounds from the organic matrix. The method is applicable for the quantitative determination of silver by inductively coupled plasma atomic emission spectroscopy.

Bacteria↗
PubMed2001

Biocompatibility of silver nitrate and ofloxacine coated bioabsorbable SR-PLLA rods.

The purpose of this study was to evaluate the biocompatibility of silver nitrate and ofloxacine coatings of bioresorbable self-reinforced poly-L-lactic acid (SR-PLLA) rods. SR-PLLA rods coated with pure poly(caprolactone-co-L-lactide) or blended with silver nitrate (10, 5 or 2 weight-%) or ofloxacine (5 or 2 weight-%) were implanted in the dorsal muscles of 25 male rabbits. Tissue reactions caused by implantation trauma were seen 1 week after implantation. The positive control and 10 w-% silver nitrate coating showed the most marked reactions 1 month after implantation. Only sparse reactions were seen 6 months after implantation. Tissue reactions were scored semi-quantitatively. As a result of this study, we concluded that silver nitrate or ofloxacine coatings up to five w-% did not alter the good biocompatibility of SR-PLLA essentially. The method may lead to the possibility of preventing bacterial adhesion to urological stents during insertion.

Absorbable Implants↗
PubMed1999

Physiology of acute silver toxicity in the starry flounder (Platichthys stellatus) in seawater.

Physiological effects of exposure to silver (AgClnn-1; 250 micrograms Ag l-1 or 1000 micrograms Ag l-1) in seawater fish were investigated using adult starry flounders. While all fish survived up to 10 days in 250 micrograms Ag l-1, flounders started to die after day 4 in 1000 micrograms l-1. Dose-dependent increases in plasma and hepatic silver concentrations showed that silver was available for uptake. There were minimal negative effects on hematological parameters, acid-base status, and blood gases. Plasma ammonia showed a pronounced (three- to four-fold), but transient increase in flounders exposed to either 250 micrograms Ag l-1 or 1000 micrograms Ag l-1. Whole body ammonia and acid equivalent efflux measurements indicated that ammonia retention was due to a combination of stimulated production and inhibited excretion. In the 1000-microgram Ag l-1 group there was a similar transient increase in plasma [magnesium], which was restored by day 4. In contrast, plasma chloride and sodium levels increased gradually towards the point when fish began to die. At 250 micrograms Ag l-1, the Na+/K(+)-ATPase activity of the intestine was unaffected but there was a two-fold increase in branchial Na+/K(+)-ATPase activity. The latter effect was interpreted as compensation for an elevated chloride and sodium load. The increases in plasma chloride and sodium concentrations were accompanied by a marked suppression of drinking, thereby indicating that acute silver toxicity was likely caused by a combination of elevated electrolyte concentrations and dehydration.

Acids↗
PubMed2006

The ubiquitin-binding protein p62 identifies argyrophilic grain pathology with greater sensitivity than conventional silver stains.

The routine diagnosis of argyrophilic grain disease is fraught by the lack of availability of an easily applied reproducible stain that can highlight the grain pathology with sensitivity and with minimal background. The Gallyas silver iodide technique is not widely used and, even in experienced hands, is difficult to perform due to inconsistencies inherent in silver-based techniques on thin sections. Grain pathology can be detected using immunohistochemistry for phosphorylated tau protein, but the grain pathology is most often masked by background tau-positive material; leading to problems with interpretation, especially for practitioners seeing small numbers of cases. There is a need for a reliable immunohistochemical stain that can detect grain pathology and provide a clear contrast between grains and other tau-positive neurodegenerative pathologies. We have investigated the novel ubiquitin-binding protein p62 as a potential biomarker for grain pathology in argyrophilic grain disease. Four cases of argyrophilic grain disease, in which the pathology was determined using the Gallyas silver iodide technique, were re-assessed using paraffin-embedded sections immunostained with antibodies specific for p62. We found that the detection of grain pathology was more sensitive than with silver-based techniques and that the resolution of the pathology was significantly improved. We suggest that p62 could be used to replace the Gallyas technique in the routine diagnosis of argyrophilic grain disease.

Adaptor Proteins, Signal Transducing↗
PubMed1982

Some considerations regarding the degradational interactions between mouth rinses and silver-soldered joints.

For immersion tests with mouth rinses of Lavoris, Green Mint, and Cepacol, silver solders and silver-soldered stainless steel joints exhibited corrosive degradational reactions. Exposures to Lavoris resulted in the severest surface attack as followed by optical microscopy, scanning electron microscopy, and energy-dispersive x-ray microanalysis. This was confirmed by measurements of electrochemical potential and polarization. The cyclic voltammograms in Lavoris indicated a highly active corrosion potential of -0.94 v. sce, while potentials in Mint and Cepacol were only about -0.25 v. This activity is attributed to the presence of zinc chloride as the active agent in Lavoris, as well as the high zinc content (up to about 20 percent) and even higher zinc concentrations contained in copper-zinc microstructural phases of the silver solders and the ease for dezincification corrosive attack. Large increases in current above about -0.2 v. are observed with all rinse solutions as well as a prepared saliva substitute solution. The importance of toxicologic considerations of the agents released from silver solders and the interactions of corrosion with stress as factors in causing delayed failures of soldered joints are discussed. The presently available commercial solders without cadmium and zinc contents, but with higher fusion temperatures and decreased flow characteristics, are recommended for dental applications to increase the resistance to corrosion.

Chemical Phenomena↗