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At least 1,063 records · Page 59Linked to original sources
PubMed2003

Experiences of the first 16 hospitals using copper-silver ionization for Legionella control: implications for the evaluation of other disinfection modalities.

BACKGROUND AND OBJECTIVES: Hospital-acquired legionnaires' disease can be prevented by disinfection of hospital water systems. This study assessed the long-term efficacy of copper-silver ionization as a disinfection method in controlling Legionella in hospital water systems and reducing the incidence of hospital-acquired legionnaires' disease. A standardized, evidence-based approach to assist hospitals with decision making concerning the possible purchase of a disinfection system is presented. DESIGN: The first 16 hospitals to install copper-silver ionization systems for Legionella disinfection were surveyed. Surveys conducted in 1995 and 2000 documented the experiences of the hospitals with maintenance of the system, contamination of water with Legionella, and occurrence of hospital-acquired legionnaires' disease. All were acute care hospitals with a mean of 435 beds. RESULTS: All 16 hospitals reported cases of hospital-acquired legionnaires' disease prior to installing the copper-silver ionization system. Seventy-five percent had previously attempted other disinfection methods including superheat and flush, ultraviolet light, and hyperchlorination. By 2000, the ionization systems had been operational from 5 to 11 years. Prior to installation, 47% of the hospitals reported that more than 30% of distal water sites yielded Legionella. In 1995, after installation, 50% of the hospitals reported 0% positivity, and 43% still reported 0% in 2000. Moreover, no cases of hospital-acquired legionnaires' disease have occurred in any hospital since 1995. CONCLUSIONS: This study represents the final step in a proposed 4-step evaluation process of disinfection systems that includes (1) demonstrated efficacy of Legionella eradication in vitro using laboratory assays, (2) anecdotal experiences in preventing legionnaires' disease in individual hospitals, (3) controlled studies in individual hospitals, and (4) validation in confirmatory reports from multiple hospitals during a prolonged time (5 to 11 years in this study). Copper-silver ionization is now the only disinfection modality to have fulfilled all four evaluation criteria.

Centers for Disease Control and Prevention, U.S.↗
PubMed1992

Detection of Pneumocystis carinii. Comparative study of monoclonal antibody and silver staining.

The sensitivity of Pneumocystis carinii detection using silver stain (Grocott method) was compared to that using the avidin-biotin-complex immunoperoxidase (IP) staining method with anti-P. carinii monoclonal antibody. Silver stain detected only cyst wall, whereas IP stained both cyst wall and trophozoites. Serial sections of formalin-fixed, paraffin-embedded autopsy lung specimens from 41 acquired immune deficiency syndrome patients in three disease categories were stained: I--premortem or autopsy diagnosis of P. carinii pneumonia (13 cases); II--history of treated P. carinii pneumonia but no P. carinii detected in autopsy tissue specimens (15 cases); and III--no clinical or autopsy evidence of P. carinii pneumonia (13 cases). Smears from 7 bronchoalveolar lavages (3 positive) and 11 induced sputa (1 positive) also were stained. All cases of P. carinii in category I were detected with equal sensitivity. P. carinii undetected by silver stain in category II and III cases and in bronchoalveolar lavages and induced sputa were not revealed by IP. Detection of trophozoites by IP did not improve sensitivity because the staining pattern was amorphous or focally granular, and thus easily confused with nonspecific staining of mucin or intracellular or free particulate material. Reliable identification of trophozoites could be made only with coexisting cyst structures. Silver staining was more advantageous because it also identified fungal infections and was faster and more cost effective than IP.

Antibodies, Monoclonal↗
PubMed1994

Silver impregnation reveals neuronal damage in cingulate cortex following 4 VO ischaemia in the rat.

An intriguing feature of global ischaemic cell loss is the sensitivity of certain neuronal populations and the relative resistance of others. Silver impregnation was used to ascertain the pattern and extent of cell loss following 15 min 4 VO ischaemia in the rat. Cell loss was observed primarily in the CA1 region of the hippocampus, as assessed by both cresyl violet and silver stains. However, degenerating neurones were most readily identifiable when impregnated with silver, and additional regions of neuronal loss were selectively revealed by silver staining in the hippocampal hilar region, dorsolateral striatum, neocortex and cingulate cortex. Damage to cingulate is a hitherto unreported consequence of 4 VO global ischaemia. This novel finding may have implications for ischaemic brain-behaviour relationships.

Animals↗
PubMed2003

Occupational corneal argyrosis in art silver solderers.

PURPOSE: To determine the value of confocal and specular microscopy in the examination of corneal argyrosis in art silver solderers. METHODS: Six patients with corneal argyrosis underwent a complete physical and ophthalmologic examination. Specular microscopy was performed in three cases, and in vivo confocal microscopy in four cases. Ultrasound biomicroscopy and corneal topography were performed in three cases. A conjunctival specimen of one patient was examined histologically in paraffin sections. RESULTS: Slit-lamp examination showed gray, diffuse opacities in the deep corneal stroma. Confocal microscopy showed highly reflective deposits with a granular pattern anterior to the corneal endothelium and hypereflective keratocyte nuclei with visible cytoplasm in the anterior stroma. Specular microscopy demonstrated round white bodies anterior to the corneal endothelium. Silver deposits were not found histologically. CONCLUSIONS: Silver solderers with long-term exposure to silver compounds are at high risk of developing corneal argyrosis. We conclude that specular microscopy and in vivo confocal microscopy provided important information for the diagnosis of corneal argyrosis.

Aged↗
PubMedDate not supplied

Some chemical principles applicable to some silver and gold staining methods for neuropathological studies.

Some of the chemical principles involved in some silver and gold staining procedures for neuropathological studies are analyzed in the light of experience with methods for astrocytes, microglia, axons and reticulin fibers. The role of formalin fixation, and of treatment with ammonium bromide or oxidizing agents prior to staining for glial cells or reticulin fibers respectively, is described. The silver staining methods are divided into two fundamentally different groups. One is based on the use of silver diammine solutions with or without other substances such as carbonates or pyridine, and at varying times, gold toning. This group encompasses a great variety of techniques for staining glial cells, reticulin fibers and axons. The second group is based on the use of weak solutions of silver ions, reduction in a photographic developer, treatment with gold chloride, and a second reduction in oxalic acid. This group is represented by methods for staining axons and reticulin fibers. A brief analysis of the gold and mercuric chloride methods for astrocytes is also given.

Astrocytes↗
PubMed1994

Efficacy of silver nitrate pencils in the treatment of common warts.

Common warts are an important issue, especially in children and young adults. The methods proposed for common wart treatment are painful, destructive, and require special experience and devices. The chemical cauterization effect of silver nitrate on warts is noted in the classical pharmaceutical textbooks. In order to test this effect for this purpose, a placebo controlled clinical study was performed on 70 patients. On 35 randomly selected patients, a silver nitrate stick was used, and, on the other 35 patients, black ink was used. At the end of this study, of the patients treated with the silver nitrate stick, 15 (43%) were completely healed, 9 (26%) were partially healed, and 11 (31%) were not healed. Of the patients treated with black ink, 4 (11%) were completely healed, 5 (14%) were partially healed, and 26 (74%) patients were not affected. Thus the silver nitrate stick affected the warts of 24 (69%) patients. Therefore, this method appears to be an effective, economic, and easily applicable treatment for common warts.

Administration, Topical↗
PubMed1990

Retrieval of silver cones using different techniques.

Three different techniques of silver cone retrieval were investigated in 41 teeth containing 91 silver cones. The techniques used for retrieval were as follows: (i) hand instrumentation with files, spoon excavators and forceps; (ii) the automated Canal-Finder-System; (iii) ultrasonic devices. In all teeth, these techniques were used in the same sequence, starting with hand instrumentation, followed by the Canal-Finder-System, and ending with ultrasonic devices. Fifty-two of the 91 cones (57 per cent) could be removed with hand instruments. Of the remaining 39 cones, 19 were removed after using the Canal-Finder-System. An additional 10 cones could be removed after the use of ultrasonics. Two cones could only be bypassed by the Canal-Finder-System but were not removed with any of the techniques investigated in this study. Eight silver cones (9 per cent) could neither be bypassed nor removed. It was concluded that silver cone retrieval in more than half the cases could be performed easily with hand instruments, particularly spoon excavators. The automated Canal-Finder-System and ultrasonics proved to be helpful devices in many difficult cases, but did not guarantee success in every case.

Humans↗
PubMed2004

Effect of saliva on an antimicrobial tissue conditioner containing silver-zeolite.

The purpose of this study was to evaluate the influence of human saliva on the antimicrobial effect of a tissue conditioner containing an antibiotic agent, silver-zeolite. Samples of each tissue conditioner with or without silver-zeolite were prepared and a plastic disk was used as a control. Candida albicans and nosocomial respiratory infection-causing bacteria, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa and the Streptococcus milleri group (S. constellatus and S. intermedius), were selected as test microorganisms. Antimicrobial effects of samples after water or saliva immersion for 28 days were evaluated by counting the number of viable cells [colony forming unit (CFU)] in each microbial suspension (100 microL). All data were statistically analysed by one-way anova and Bonferroni's test (P < 0.05). The antimicrobial effects of samples with silver-zeolite immersed in saliva against C. albicans, S. aureus and MRSA were observed while CFU of P. aeruginosa indicated no significant difference from that of the control. As for the S. milleri group, its CFU after saliva immersion showed the significantly smaller value than that of the control. It is concluded that the antimicrobial effects of samples containing silver-zeolite against all tested microbes except for P. aeruginosa and the S. milleri group are not influenced by saliva immersion for 28 days.

Anti-Bacterial Agents↗
PubMed1994

A modified NOR-silver impregnation technique for amyloid plaques and neurofibrillary tangles: comparative assessment.

A modified nucleolar organizer region (NOR)-silver impregnation technique was recently introduced allowing the simultaneous staining of neurofibrillary tangles (NFT) and amyloid plaques (AP) in a single section. This impregnation technique proved to be very effective, rapid, of low cost, and to yield consistent results even in brain tissue fixed for long periods of time. In the present study, several silver impregnation and immunohistochemical techniques were applied and their reliability for the demonstration of NFT and AP was analysed. The modified NOR stain allowed the reliable and simultaneous demonstration of both amyloid plaques and neurofibrillary tangles; this method produced better results than the standard silver impregnation techniques. It is only in their early stages of formation that NFT cannot be detected by this method and, instead, immunohistochemistry for tau-2 is required. There was no significant difference in the staining properties for amyloid plaques between the modified NOR silver impregnation technique and the anti-beta-A4 immunostain.

Aged↗
PubMed1979

Levels of mercury and silver in dust from the trimming of amalgam dies.

The levels of mercury and silver in dust arising from the trimming, i.e. grinding, of amalgam dies in dental laboratories have been measured. In breathing air close to the workpiece, the mercury and silver contents exceeded the threshold limit values for short-term exposure by factors of aboit 60 and 400 in cases when local ventilation was not in use. With efficient local exhaust systems enabling a dust reduction of about 94%, the short-term exposure limit values for mercury and silver were exceeded by factors of about 4 and 20 respectively. Mercury and silver were assayed quantitatively by means of nuclear chemical analysis. A major part of the amalgam dust consisted of respirable particles. The collected dust comprised about 80% amalgam and 20% particulate matter from grinding wheels and stones according to SEM and EDAX measurements.

Air Pollutants↗
PubMed1980

Effect of fluoride and non-fluoride salts of copper, silver and tin on the acidogenicity of dental plaque in vivo.

The aim of the present study was to assess the relative importance of the metal and fluoride components in the inhibiting effect on the acidogenicity of plaque exhibited by silver fluoride and copper fluoride. The effect of these salts was therefore compared with that of silver nitrate and copper sulfate. Four subjects with a 3-day-old sucrose induced plaque received topical application of the test agents. Plaque pH-measurements, in the presence of sucrose, were performed prior to and at given time intervals after this application. No significant differences were observed in the inhibitory effect of 5 mM solutions of the copper and silver salts. These salts were all more effective than stannous fluoride in the first 4 h following application. Sodium fluoride was the least effective. All metals tested were found to be retained in plaque. The inhibitory activity appears to be carried by the cations. Other properties than retention alone may explain the higher effectiveness observed for silver and copper.

Acids↗
PubMed2005

The silver-releasing foam dressing, Contreet Foam, promotes faster healing of critically colonised venous leg ulcers: a randomised, controlled trial.

The study compared the effect of a sustained silver-release foam dressing (Contreet Foam) with a foam dressing (Allevyn Hydrocellular) without added silver in critically colonised venous leg ulcers with delayed healing. The study was a multicentre, open, randomised, controlled study lasting for 4 weeks. Ulcer area and healing were assessed weekly. Odour, maceration, absorption capacity and leakage were evaluated at dressing changes. All adverse events were recorded. One hundred and twenty-nine patients were included (Contreet Foam: 65, Allevyn Hydrocellular: 64). The two groups were comparable in all respects. After 4 weeks, there was a significantly greater reduction in ulcer area in the Contreet Foam group (45%) than in the Allevyn Hydrocellular group (25%). After 1 and 4 weeks, odour was present in significantly less of the ulcers in the Contreet Foam group (17% and 19%, respectively) compared with the Allevyn Hydrocellular group (47% and 39%, respectively) and at the final visit there were significantly fewer leakages in the Contreet Foam group (19%) compared with the Allevyn Hydrocellular group (49%). Also, less maceration was observed after 1 and 4 weeks in the Contreet Foam group (34% and 37%, respectively) compared with the Allevyn Hydrocellular group (55% and 48%, respectively). The occurrence and cause of adverse events were equally distributed between the study groups. The present study provides evidence of the superior performance of the silver-releasing dressing, Contreet Foam, compared with a traditional moist foam wound healing dressing in the treatment of critically colonised, chronic venous leg ulcers. The results of this randomised, controlled study suggest an important role of sustained silver-releasing dressings in the treatment of critically colonised chronic wounds.

Adult↗
PubMed1997

Safety issues related to the use of silver fluoride in paediatric dentistry.

Due to its exceedingly high fluoride content, 40% silver fluoride solution has the potential to cause fluorosis when used in young children. In vitro testing conducted in the present investigation indicates that application of 40% silver fluoride to deep carious lesions or its use as a 'spot' application agent could result in 3 to 4 mg of fluoride reaching the systemic circulation. As scientifically-based clinical trials on the safety of 40% silver fluoride have not been conducted, it would be appropriate for it to be withdrawn from further clinical use until proper testing and evaluation have been carried out. In view of the possibility that lower strength solutions of silver fluoride (1-4%) may be just as effective as 40% in 'arresting' deep caries, testing should focus on such solutions, particularly as the potential for toxicity from their fluoride content would be reduced by a factor of 10-40.

Administration, Topical↗
PubMed1985

Silver-intensified gold and peroxidase as dual ultrastructural immunolabels for pre- and postsynaptic neurotransmitters.

An ultrastructural immunostaining method that uses silver-intensified gold was combined with another procedure that uses biotin peroxidase conjugates to allow simultaneous identification of two neurotransmitter-related antigens in the central nervous system. Tyrosine hydroxylase-immunoreactive neurons labeled with silver-intensified gold could be differentiated at both light and electron microscopic levels from glutamate decarboxylase-immunoreactive neurons labeled with peroxidase. Cross reactivity of the second group of immunoreagents with the first group was reduced by the heavy metal silver shell formed around the colloidal gold immunoglobulin complex. With this dual pre-embedding method, peroxidase-stained axons containing the inhibitory neurotransmitter gamma-aminobutyric acid were found to synapse directly on silver-stained dopamine neurons in the rat dorsomedial hypothalamus. This approach can be used in combination with a post-embedding immunocytochemical colloidal gold procedure, allowing ultrastructural identification of three neurotransmitter-related antigens in the same tissue section.

Animals↗
PubMed1997

Direct evidence for uptake of intact liposomes encapsulating silver sulfadiazine by cultured human keratinocytes based on combined transmission electron microscopy and X-ray microanalysis.

Cultured human keratinocytes were exposed to liposomally encapsulated silver sulfadiazine, free silver sulfadiazine, silver sulfadiazine cream, and a corresponding vehicle for 5 min to 24 h. Phagocytosis of intact liposomes by keratinocytes was demonstrated in vitro by combined X-ray microanalysis and electron microscopy. Silver as an active part of the antimicrobial served as an electron-dense marker.

Anti-Infective Agents, Local↗
PubMed2005

Bactericidal actions of a silver ion solution on Escherichia coli, studied by energy-filtering transmission electron microscopy and proteomic analysis.

Bactericidal actions of the silver ion on Escherichia coli as a model microorganism were studied using energy-filtering transmission electron microscopy (EFTEM), two-dimensional electrophoresis (2-DE), and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). EFTEM observations demonstrated that the silver ion readily infiltrates the interior of E. coli, contrary to the early hypothesis that it resides initially in the cell membrane area. Furthermore, 2-DE and MALDI-TOF MS indicated that the expression of a ribosomal subunit protein as well as that of some other enzymes and proteins is affected by the silver ion. The present results demonstrate for the first time that one of the major bactericidal functions of the silver ion is its interaction with the ribosome and the ensuing inhibition in expression of the enzymes and proteins essential to ATP production.

Anti-Bacterial Agents↗
PubMed1972

Location of polysaccharide on Chlamydia psittaci by silver-methenamine staining and electron microscopy.

Previous serological studies have indicated that the group antigen of chlamydial organisms is composed of an acidic polysaccharide and a lipid component. The present study was undertaken in an effort to locate this polysaccharide complex by use of electron microscopy and a silver-methenamine marker. The meningopneumonitis strain of Chlamydia psittaci was propagated in HeLa-M cell culture. Organisms were purified by differential centrifugation, treatment with Genetron, and by gel filtration. After fixation and embedding, sections were obtained for electron microscopy. Sections were stained for carbohydrates with silver-methenamine. A double layer of regularly spaced silver grains of uniform size was observed at the periphery of the sectioned organisms tracing the contours of the surface membrane (cell wall). This intensity of staining was observed only when sections were oxidized with periodate prior to silver-methenamine staining. Prior treatment with 1% sodium deoxycholate resulted in a significant reduction in staining. It is considered probable that the periodate-sensitive polysaccharide found at the periphery of the organisms represents, or is a component of, the group antigen of these organisms.

Cell Wall↗