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PubMed2003

Severe generalized argyria secondary to ingestion of colloidal silver protein.

Argyria is a rare cause of cutaneous discolouration caused by silver deposition. We report a case of dramatic and diffuse argyria secondary to ingestion of colloidal silver protein over a 1-year period. Stained electron microscopy with spectral analysis was used to confirm the clinical diagnosis. Silver-protein complexes are deposited in the skin and reduced to inert silver salts by sunlight in a process similar to that harnessed in photography. Our patient had obtained the silver for consumption via mail order. It had been advertised as a cure for a variety of diseases. Colloidal silver protein is commercially available as a 'food supplement', hence circumventing the strict controls placed on medicines.

Argyria↗
PubMed1988

Prophylaxis of gonococcal and chlamydial ophthalmia neonatorum. A comparison of silver nitrate and tetracycline.

We evaluated the use of silver nitrate drops and tetracycline ointment for the prophylaxis of ophthalmia neonatorum in a controlled trial involving 2732 newborns in Nairobi, Kenya. The overall rates of prevalence of intrapartum maternal gonococcal and chlamydial infection were 6.4 and 8.9 percent, respectively. After prophylaxis with silver nitrate, the incidence rates of gonococcal, chlamydial, and nongonococcal, nonchlamydial ophthalmia neonatorum were 0.4, 0.7, and 6.2 percent, respectively, whereas after prophylaxis with tetracycline, the rates were 0.1, 0.5, and 4.5 percent. The attack rates of gonococcal ophthalmia neonatorum in newborns exposed to Neisseria gonorrhoeae at birth were 7.0 percent in those receiving silver nitrate and 3.0 percent in those receiving tetracycline (95 percent confidence interval for the difference in rates, -3.4 to 11.4 percent). As compared with historical controls, the incidence of gonococcal ophthalmia neonatorum decreased 83 percent among infants treated with silver nitrate and 93 percent among those treated with tetracycline. Failure of prophylaxis was associated with postpartum maternal endometritis (P = 0.05). Among newborns exposed to maternal infection with Chlamydia trachomatis, chlamydial conjunctivitis developed in 10.1 percent given silver nitrate and in 7.2 percent given tetracycline (95 percent confidence interval for the difference in rates, -4.7 to 10.5 percent), yielding reductions in the incidence of chlamydial ophthalmia of 68 and 77 percent, respectively, as compared with the historical controls. We conclude that tetracycline is as effective as silver nitrate in preventing gonococcal ophthalmia neonatorum.

Chlamydia Infections↗
PubMed2001

Expressions of proliferation markers (Ki-67, proliferating cell nuclear antigen, and silver-staining nucleolar organizer regions) and of p53 tumor protein in gestational trophoblastic disease.

OBJECTIVE: This study was undertaken to determine whether the expressions of 3 proliferation markers (Ki-67, proliferating cell nuclear antigen, and silver-staining nucleolar organizer regions) and of p53 tumor protein could differentiate spontaneous abortions from gestational trophoblastic diseases and also discriminate among gestational trophoblastic disease subgroups. STUDY DESIGN: Twenty-two partial hydatidiform moles, 17 complete hydatidiform moles, 6 invasive hydatidiform moles, and 20 nonhydropic spontaneous abortions (control group) were evaluated by means of immunohistochemical techniques with antibodies to Ki-67, proliferating cell nuclear antigen, and p53. One-step silver staining was used to detect silver-staining nucleolar organizer regions. RESULTS: The expressions of Ki-67, proliferating cell nuclear antigen, silver-staining nucleolar organizer regions, and p53 were significantly higher in the gestational trophoblastic disease group than in the control group. The results of linear discriminant analysis showed that silver-staining nucleolar organizer region count had the highest sensitivity and specificity (93.3% and 100%, respectively) for distinguishing gestational trophoblastic disease from spontaneous abortion. Sensitivity and specificity for discriminating gestational trophoblastic disease from spontaneous abortion increased to 100% when all four markers were used together. Proliferating cell nuclear antigen was found to be the best discriminating variable for differentiating among gestational trophoblastic disease subgroups. CONCLUSION: Our findings suggest that expressions of Ki-67, proliferating cell nuclear antigen, silver-staining nucleolar organizer regions, and p53 may aid in the diagnosis of gestational trophoblastic diseases. These fairly rapid, simple, and economic techniques could serve as a useful adjunct to conventional methods in the diagnosis of gestational trophoblastic diseases.

Abortion, Spontaneous↗
PubMedDate not supplied

Distribution of rDNA in the nucleus of Giardia lamblia: detection by Ag-I silver stain.

Previous investigations have proved that diplomonads have primitive cell nuclei and lack a nucleolus. We determined the distribution of ribosomal DNA (rDNA) in diplomonad nuclei that lacked a nucleolus. Giardia lamblia was used as the experimental organism with Euglena gracilis as the control. The distribution of rDNA was demonstrated indirectly by the modified Ag-I silver technique that can indicate specifically the nucleolus organizing region (NOR) by both light and electron microscopy. In ultrathin sections of silver stained Euglena cells, all silver grains were concentrated in the fibrosa of the nucleolus, while no silver grains were found in the cytoplasm, nucleoplasm, condensed chromosomes or pars granulosa of the nucleus. In the silver stained Giardia cells, no nucleolus was found, but a few silver grains were scattered in the nucleus. This suggests that the rDNA of Giardia does not form an NOR-like structure and that its nucleus is in a primitive state.

Animals↗
PubMed1994

Controlled evaluation of copper-silver ionization in eradicating Legionella pneumophila from a hospital water distribution system.

A controlled evaluation was made of the efficacy of copper-silver ionization in eradicating Legionella pneumophila from a hospital water supply. Copper-silver ionization units were installed on the hot water recirculation line of one building with water fixtures positive for Legionella species. Another building with the same water supply served as a control. Legionella species persisted within the system when copper and silver concentrations were < 0.3 and < 0.03 ppm, respectively. When copper and silver concentrations were > 0.4 and > 0.04 ppm, respectively, there was a significant decrease in Legionella species colonization, but the percentage of water fixtures positive for organisms was unchanged in the control building. When the ionization unit was inactivated, water fixtures continued to be free of Legionella species for 2 additional months. Copper-silver ionization can eradicate L. pneumophila in a water distribution system. The advantages of copper-silver ionization include relatively low cost, straightforward installation, easy maintenance, nontoxic by-products and the presence of a disinfecting residual.

Copper↗
PubMedDate not supplied

Analytical findings in a fatal poisoning with silver compound.

A 69-year-old male radio technician drank an unknown amount of a liquid and died within 5 h at a hospital. Mainly silver, potassium, and calcium, among other substances, were found in the residue of the liquid from the empty bottle by means of the spectrographic method (30.7% silver and 25.5% potassium using atomic absorption spectometry [AAS] method). The toxicological analysis of the postmortem material for silver performed by the flame AAS method (stomach, 2.43 micrograms/g; intestines, 1.12 micrograms/g; liver, 6.29 micrograms/g; kidney, 4.85 micrograms/g; spleen, 30.1 micrograms/g; heart, 10.8 micrograms/g; lung, 14.8 micrograms/g; and brain, 0.61 microgram/g) confirmed fatal silver compound poisoning. The results were verified by the standard additions technique and recovery examination. However, no increase in the potassium concentrations was observed in the postmortem material. There have been no data in available literature on the distribution of silver in tissues in people after oral administration of silver salts.

Aged↗
PubMed1975

Modification of a selenium toxicity in chicks by dietary silver and copper.

Studies were conducted to determine the effects of high levels of dietary silver nitrate and copper sulfate on the response of chicks to toxic levels of dietary selenium. Adding 5 ppm or more selenium to a basal stock diet significantly reduced growth rate, and 40 ppm or high significantly increased mortality during the 2-week experiments. Deitary silver or copper (1,000 ppm) counteracted the growth depression and prevented mortality at the higher levels of selenium. Hepatic selenium reached a maxiumum in chicks fed the basal diet with 10 ppm dietary selenium. Hepatic selenium of chicks fed silver was less than that of the control chicks when diets containing 10 ppm or less selenium were fed. Adding copper to the diet resulted in considerable accumulation of selenium in the liver, which was evident even at the lower levels of added selenium. Rseults of an experiment to determine the effects of deitray silver and copper on the distribution of 75-Se administered either orally or in tramusculary showed that silver interfered with absorption of selenium. The results of these experiments suggest that silver modifies selenium toxity both by interfering with selenium absorption and by causing the accumulation of a nondeleterious selenium compound in the tissues. Copper modifies selenium toxicity primarily by causing the accumulation of a nondeleterious compound in the tissues.

Administration, Oral↗
PubMed1999

Efficacy of silver-coating central venous catheters in reducing bacterial colonization.

OBJECTIVE: To compare silver-coated and uncoated central venous catheters regarding bacterial colonization. To assess the relative contribution of catheter hub and skin colonization to catheter tip colonization. DESIGN: Prospective, randomized clinical trial. SETTING: Intensive care unit in a university hospital. PATIENTS: Patients after cardiac surgery who required a central venous double-lumen catheter (DLC). INTERVENTIONS: Sixty-seven adult patients were prospectively randomized to receive either a silver-coated (S group, n = 34) or an uncoated control (C group, n = 33) DLC. Blood cultures were drawn at catheter removal, and removed catheters were analyzed with quantitative cultures. Typing of microorganisms included DNA fingerprinting. MEASUREMENTS AND MAIN RESULTS: Catheters were removed if no longer necessary and aseptically divided into three segments: segment A, the catheter tip; segment B, an intermediate section; and segment C, the subcutaneous portion. Bacterial catheter colonization was quantitatively measured using sonication to detach adherent bacteria from the catheter segments in the broth and subsequent culture of an aliquot. Selected isolates of coagulase-negative staphylococci and other bacteria from catheter segments were examined by means of pulsed-field gel electrophoresis (PFGE) after macrorestriction digestion of bacterial DNA to study colonization pathogenesis. Quantitatively lower bacterial colonization could be demonstrated on the silver-coated catheters (200 +/- 550 colony forming units [CFUs]/cm catheter segment; mean +/- SD). The difference in the control catheters (1120 +/- 5350 CFUs/cm catheter segment; mean +/- SD) was not, however, significant (p = .25). The frequency of colonization of at least one catheter segment was 52.9% for the silver-coated catheters and 57.6% for the control catheters (p= .44), without any significant differences in the colonization of corresponding catheter segments. The rate of significant catheter colonization (i.e., > or = 10(3) CFUs/cm catheter by quantitative catheter culture or > or = 10(3) CFUs/mL by luminal flush) was nine in the silver group and seven in the control group, a difference that failed to reach significance (p = .41). Two patients in both groups developed catheter-related bacteremia. Pattern analysis after PFGE demonstrated that about 70% of the isolates found on the catheter tip were identical with those on the skin at the insertion site, whereas about 75% were identical with those recovered from the hub. In 29% of colonized catheters, identical bacteria were found on the hub and the skin at the insertion site. CONCLUSIONS: Silver-coating of DLCs did not significantly reduce bacterial catheter colonization compared with the control catheters. PFGE analysis of coagulase-negative staphylococci and other bacteria demonstrated various pathogenic routes of catheter-related colonization, whereby the microorganisms of the skin flora around the insertion site must be regarded as the main source of catheter-related infections.

Adult↗
PubMed2001

The product of the ybdE gene of the Escherichia coli chromosome is involved in detoxification of silver ions.

Transcription of the ybcZ--ylcA ylcBCD--ybdE region of the Escherichia coli K38 chromosome was analysed by Northern RNA--DNA hybridization, RT-PCR and primer extension. Transcription of a dicistronic ybcZ--ylcA mRNA and a tetracistronic ylcBCD--ybdE mRNA was induced by silver and was initiated from the sigma-70 promoters ylcAp and ylcBp. Expression of beta-galactosidase activity from a Phi(ylcBp--lacZ) operon fusion was also induced by Ag(+) and Cu(2+), but not by Zn(2+). In-frame deletion of ybdE from the chromosome yielded a silver-sensitive E. coli mutant strain which did not differ in its copper resistance from its wild-type strain. On the other hand, deletion of the copA gene for the copper-exporting P-type ATPase CopA resulted in copper sensitivity, but not in silver sensitivity. A Delta ybdE Delta copA double mutant strain behaved towards copper as the Delta copA strain and towards silver as the Delta ybdE strain. Thus, in E. coli, the YlcBCD--YbdE system may be involved in silver- but not in copper resistance, and CopA may be involved in copper- but not in silver resistance.

Bacterial Proteins↗
PubMed2005

Silver nitrate cautery in aphthous stomatitis: a randomized controlled trial.

BACKGROUND: Aphthous stomatitis is a painful, recurrent disease of the oral mucous membrane. Silver nitrate sticks have been used for a long time to provide pain relief for the duration of an aphthous ulceration, with only one application. Silver nitrate causes chemical cauterization and increases the depth of injury. OBJECTIVES: To study the effect of chemical cautery with silver nitrate in reducing pain of aphthous ulceration and to determine if this treatment shortens or prolongs healing. METHODS: In a randomized, patient-blinded, placebo-controlled study, 97 patients with painful minor oral aphthous ulceration were randomized to receive silver nitrate cautery or placebo. The severity of pain was rated on a three-category scale (severe, mild, none) and was recorded each day until the seventh day after the procedure. The lesion size was recorded at the time of the procedure and on the seventh day afterwards. In the treatment group, the ulcer was gently painted with a silver nitrate stick until it turned white. In the placebo group, the ulcer was gently painted with a placebo stick. RESULTS: In the treatment group, 33 of 47 patients (70%) evaluated and in the placebo group, four of 38 patients (11%) evaluated had reduction in severity of pain 1 day after the procedure. The difference was statistically significant (P < 0.001). On the seventh day after the procedure, the ulcers were completely re-epithelialized in 39 patients (83%) in the treatment group and in 34 patients (89%) in the placebo group. The difference was not statistically significant (P = 0.39). CONCLUSIONS: The results of our study showed that one application of silver nitrate can decrease the severity of pain in aphthous ulceration without significantly shortening or prolonging healing time. We did not observe any side-effects in our study. The effect is rapid and lasts for the duration of the lesion. The treatment is simple and cost-effective in patients with infrequent recurrences.

Administration, Oral↗
PubMed2004

Anti-inflammatory effect of topical nanocrystalline silver cream on allergic contact dermatitis in a guinea pig model.

The anti-inflammatory activity of topical nanocrystalline silver cream was assessed and compared with the effects of topical steroids and currently available immunosuppressants using a guinea pig model of allergic contact dermatitis. Dermatitis was induced with dinitrochlorobenzene and treated with different concentrations of nanocrystalline silver, medium and high potency steroids, tacrolimus and pimecrolimus, or appropriate vehicles once daily for 5 days. Erythema was evaluated daily (on a score of 0 to 4, from absent to very severe) and histopathology of the skin biopsies was evaluated after 5 days of treatment. Prior to treatment, the average scores of erythema in all the groups were in the range of 3(+) to 4(+). In the no treatment and vehicles groups these scores remained at about this level for the subsequent 5 days of the study. Nanocrystalline silver reduced erythema within 1 day of treatment in a concentration-dependent manner with significant reduction at silver concentrations of 0.5% and 1% (P < 0.05) and this reduction progressed throughout the study period. Steroids and immunosuppressants produced similar decreases in erythema, with no significant differences compared to 0.5% and 1% nanocrystalline silver. In skin biopsies scored for degree of inflammatory response, effects of treatments mirrored erythema results. This study suggests that nanocrystalline silver cream may have therapeutic potential for topical treatment of inflammatory skin diseases.

Administration, Cutaneous↗
PubMed1996

Antimicrobial activity of electrochemical silver ions in nonionic surfactant solutions and in model dispersions.

The microbicidal effectiveness against Gram-positive and Gram-negative bacteria and Candida albicans of electrochemical silver ions in aqueous solutions containing nonionic surfactants was investigated. From the perspective of the possible use of anodic silver as a preservative in cosmetic or pharmaceutical preparations, microbicidal efficacy was also studied in oil/water model dispersions. Surfactants and botanical extracts partially inhibited the microbicidal effectiveness of anodic silver. Nevertheless in all the experimental conditions, silver ions reduced the microbial concentration up to 4 log units of the starting inoculum in less than 6 h. The wide microbicidal spectrum and the high rate of kill of silver ions appear, therefore, attractive enough to suggest a possible utilization of anodic silver as a preserving agent.

Candida albicans↗
PubMed1974

Mechanism of silver sulfadiazine action on burn wound infections.

The role of silver and sulfadiazine in the mechanism of action of silver sulfadiazine on burn wound infections was investigated. Silver, but not sulfadiazine, was bound by bacteria. Sulfadiazine did not act as an antibacterial agent in low concentrations, but exhibited specific synergism in combination with subinhibitory levels of silver sulfadiazine. The efficacy of silver sulfadiazine is thought to result from its slow and steady reactions with serum and other sodium chloride-containing body fluids, which permits the slow and sustained delivery of silver ions into the wound environs. In this circumstance, a relatively minute amount of sulfadiazine appears active.

Animals↗
PubMed1989

Efficacy of copper and silver ions and reduced levels of free chlorine in inactivation of Legionella pneumophila.

Water disinfection systems utilizing electrolytically generated copper and silver ions (200 and 20, 400 and 40, or 800 and 80 micrograms/liter) and low levels of free chlorine (0.1 to 0.4 mg/liter) were evaluated at room (21 to 23 degrees C) and elevated (39 to 40 degrees C) temperatures in filtered well water (pH 7.3) for their efficacy in inactivating Legionella pneumophila (ATCC 33155). At room temperature, a contact time of at least 24 h was necessary for copper and silver (400 and 40 micrograms/liter) to achieve a 3-log10 reduction in bacterial numbers. As the copper and silver concentration increased to 800 and 80 micrograms/liter, the inactivation rate significantly (P less than or equal to 0.05) increased from K = 2.87 x 10(-3) to K = 7.50 x 10(-3) (log10 reduction per minute). In water systems with and without copper and silver (400 and 40 micrograms/liter), the inactivation rates significantly increased as the free chlorine concentration increased from 0.1 mg/liter (K = 0.397 log10 reduction per min) to 0.4 mg/liter (K = 1.047 log10 reduction per min). Compared to room temperature, no significant differences were observed when 0.2 mg of free chlorine per liter with and without 400 and 40 micrograms of copper and silver per liter was tested at 39 to 40 degrees C. All disinfection systems, regardless of temperature or free chlorine concentration, showed increase inactivation rates when 400 and 40 micrograms of copper and silver per liter was added; however, this trend was significant only at 0.4 mg of free chlorine per liter.

Analysis of Variance↗
PubMed2002

Negative effect of high pH on biocidal efficacy of copper and silver ions in controlling Legionella pneumophila.

Copper-silver (Cu-Ag) ionization has effectively controlled Legionella spp. in the hot water systems of numerous hospitals. However, it was ineffective at controlling Legionella in one Ohio hospital despite the confirmation of adequate total concentrations of copper and silver ions. The pH of the water at this hospital was found to be 8.5 to 9.0. The purpose of this study was to investigate the impact of pH and other water quality parameters, including alkalinity (HCO3-), hardness (Ca2+ and Mg2+), and amount of dissolved organic carbon (DOC), on the control of Legionella by Cu-Ag ionization. Initial concentrations of Legionella and copper and silver ions used in batch experiments were 3 x 10(6) CFU/ml and 0.4 and 0.08 mg/liter, respectively. Changes in bicarbonate ion concentration (50, 100, and 150 mg/liter), water hardness (Ca2+ at 50 and 100 mg/liter; Mg2+ at 40 and 80 mg/liter), and level of DOC (0.5 and 2 mg/liter) had no significant impact on the efficacy of copper and silver ions in killing Legionella at a neutral pH. When the pH was elevated to 9 in these experiments, copper ions achieved only a 10-fold reduction in the number of Legionella organisms in 24 h, compared to a millionfold decrease at pH 7.0. Silver ions were able to achieve a millionfold reduction in 24 h at all ranges of water quality parameters tested. Precipitation of insoluble copper complexes was observed at a pH above 6.0. These results suggest that pH may be an important factor in the efficacy of copper-silver ionization in controlling Legionella in water systems.

Bicarbonates↗
PubMed1987

Potential nephrotoxic effects of exposure to silver.

A cross sectional study was conducted on workers engaged in manufacturing precious metal powder. Of the 27 workers, 96% had raised urine silver concentrations (range 0.5-52.0 micrograms/l, mean 11.3 micrograms/l) and 92% had raised blood silver concentrations (range 0.05-6.2 micrograms/100 ml, mean 1.0 microgram/100 ml). Nineteen per cent also had raised urine cadmium concentrations (range 1.9-76.0 micrograms/l, mean 11.8 micrograms/l). Most workers had symptoms of respiratory irritation and nose bleeds were reported in eight (30%) of the 27 workers. Deposition of silver in the cornea of the eye was detected in five of eight (63%) of the long term workers. Although not statistically significant, corneal deposition was associated with complaints of decreased night vision. The urinary enzyme N-acetyl-B-D glucosaminidase (NAG) was significantly raised in four individuals and was correlated with blood silver concentrations and age. In addition, the group's average NAG concentration was significantly higher than that found in a control population. No association between age and urinary NAG was found in the control group. Estimated creatinine clearance was also significantly lower in the group exposed to silver than in the control group. Kidney function appears to have been adversely affected by exposures at work but because of the exposure to cadmium the role of silver in causing the decrement in kidney function could not be definitely determined.

Acetylglucosaminidase↗
PubMedDate not supplied

Toxicity and antimicrobial activity of a hydrocolloid dressing containing silver particles in an ex vivo model of cutaneous infection.

In the present study we examined the effects of two hydrocolloid wound dressings (conventional silver-free Comfeel, silver-incorporating Contreet-H) on uninfected and Candida albicans- or methicillin-resistant Staphylococcus aureus-infected reconstituted human epithelium (RHE). The morphological alterations of the keratinocytes caused by infection and by treatment were analysed with light and electron microscopy. As a measure of epithelial cell damage the release of lactate dehydrogenase from epithelial cells into the surrounding medium was monitored. Application of Contreet-H or Comfeel to uninfected RHE induced no major morphological effects on epithelial cells. Both wound dressings reduced the growth of micro-organisms. Specific alterations of the infected epithelium (vacuoles, spongiosis, oedema, detachment of keratinocytes) and invasion of the epithelium were significantly reduced only by treatment with Contreet-H. At the ultrastructural level release of silver by Contreet-H and superior antimicrobial efficacy could be verified. In summary, treatment with both wound dressings reduced the number of pathogens, with the silver-based wound dressing providing a more effective antimicrobial activity. This resulted in a strong decrease of pathogen-specific alterations of the infected epithelium. We present evidence that delivering silver to infected keratinocytes in a moist healing environment improves the benefit/risk ratio as compared to silver-free wound dressings.

Anti-Bacterial Agents↗
PubMed2002

Quasi-linear assemblies of silver nanoparticles by highly localized anodic dissolution of copper in the hydrosol.

The assembly of silver nanoparticles into quasi-linear superstructures in solution has been demonstrated. A small dc voltage applied to fine-tipped, L-shaped copper electrodes immersed in aqueous carboxylic acid-derivatized silver nanoparticle solution leads to the anodic dissolution of copper ions. The controlled release of Cu2+ ions within the gaps results in local screening of repulsive coulombic interactions between the silver nanoparticles and the consequent formation of aggregates that are extremely stable in time. Atomic force and transmission electron microscopy images of the silver nanoparticle solution after application of an electric field showed the presence of a large number of silver nanoparticle assemblies in open, quasi-linear structures. Such open structures do not form if Cu2+ ions are added directly to the silver nanoparticle solution.

Carboxylic Acids↗