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At least 721 records · Page 40Linked to original sources
PubMed2004

Silver carbonate staining reveals mitochondrial heterogeneity.

Silver staining methods, when selective, yield a high-contrast and high-resolution image in optical microscopy. A classical method for silver impregnation of mitochondria has been applied to murine tissues and reveals a marked heterogeneity among mitochondria in single cells. This heterogeneity can be detected in the optical microscope but is even more evident at the ultrastructural level. The differences in staining intensity may reflect different stages in the mitochondrial life cycle. The progressive accumulation of uranyl-argyrophilic material may be a marker of mitochondrial aging. This highly selective staining procedure may be of use in studies of mitochondrial changes under pathological conditions and during apoptosis.

Animals↗
PubMed1998

Resistance to biofilm formation on otologic implant materials.

New materials and coatings are now being developed to resist permanent bacterial contamination of implanted medical devices. This study exposed several styles of middle ear ventilation tube materials and coatings to high concentrations of Pseudomonas and Staphylococcus. Electron microscopy was then used to evaluate these tubes' resistance to bacterial biofilm formations. Ionized, processed silicone tubes were the only tubes resistant to Pseudomonas adhesion. Tubes that were made of fluoroplastic or that were ionized processed were very resistant to Staphylococcus contamination when compared with untreated silicone or silver oxide-treated silicone. This study suggests that ionized, coated fluoroplastic would be a highly effective tube material in preventing bacterial biofilm contamination of implanted ventilation tubes.

Anti-Bacterial Agents↗
PubMed1966

A semiautomatic instrument for the radioautographic coating technique.

By means of a mechanical coating instrument a fast, simple method to coat specimens with liquid nuclear track emulsion has been devised for quantitative light and electron microscopic radioautography. In both cases, the section is mounted on a glass slide. After the vertically held slide has been immersed in the melted emulsion, the instrument withdraws it at a slow, constant speed. As a result, the specimen is coated with a thin, uniform emulsion layer composed of homogeneously distributed silver bromide crystals. The thickness of the emulsion coat may be standardized by selection of an optimal combination of emulsion dilution, temperature and withdrawal speed.

Autoradiography↗
PubMed2006

Management of a difficult-to-heal chronic wound infected with methycillin-resistant staphylococcus aureus in a patient with psoriasis following a complex knee surgery.

This report presents the difficulties encountered in managing a wound colonized with methycillin-resistant Staphylococcus aureus (MRSA) following a complex knee surgery in an elderly female patient with generalized psoriasis. The patient's chronic wound was successfully treated with nanocrystalline silver-releasing dressings (Acticoat). The patient did not develop a deep-seated infection, nor was removal of the implant needed. However, the wound infection persisted for 6 months. At 3 years follow-up, the patient has satisfactory skin over the implant on the knee.

Aged↗
PubMedDate not supplied

Graft infectivity of rifampin and silver-bonded polyester grafts to MRSA contamination.

The purpose of this study was to evaluate the ability of vascular polyester grafts with antibacterial properties to resist colonization following surface contamination by methicillin-resistant Staphylococcus aureus (MRSA) in an experimental canine model or aortic graft infection. Twenty-four pathogen-free dogs underwent replacement of the infrarenal aorta with either a rifampin-soaked (30 mg/mL) or silver-impregnated (Ag-acetate) woven polyester graft. Following implantation, the external graft surface was inoculated with 2 mL of 10(7) colony-forming units/mL (CFU) of MRSA. Preoperative antibiotic prophylaxis consisted of a single intravenous dose of 500 mg of sodium cefazolin. Four grafts of each type were explanted at 3, 7, and 14 days after implantation. Quantitative cultures (CFU/specimen) of perigraft fluid (1 mL), graft material (1 cm segment), and adjacent aorta (1 cm segment) were performed. Differences between grafts are expressed as % mean log reduction in recoverable CFU compared to the inoculation solution concentration of 10(7) CFUs. At 3 days, explanted rifampin-soaked grafts exhibited no MRSA growth (4 of 4 grafts) and a > or =97% mean log reduction of MRSA CFUs from the adjacent aorta and perigraft fluid (PGF). At 3 days, all silver-bonded grafts exhibited signs of infection and a mean log CFU reduction of MRSA ranging from 68% (absolute range 10(1)-10(3) recoverable CFU) for the graft, 79% (absolute range 10(1)-10(3) recoverable CFU) for the aorta, and 86% (absolute range 10(1)-10(4) recoverable CFU) for PGF. The 7-day rifampin group had an average log reduction in MRSA CFU of 72% (graft), 58% (PGF), 75% (aorta). Quantitative cultures of 14-day rifampin grafted demonstrated continued bacterial growth suppression with mean MRSA CFU log reductions of 82%, graft; 72%, PGF; 89%, aorta. Silver-bonded grafts demonstrated <50% mean CFU reduction in MRSA growth at 7 days (absolute range 10(5)-10(7) recoverable CFU) and 14 days (absolute range 10(3)-10(7) recoverable CFU). No animal died from sepsis or anastomotic hemorrhage. Neither rifampin- nor silver-bonded grafts demonstrated prolonged resistance to surface MRSA contamination. Rifampin-soaked polyester grafts exhibited a marked but transient resistance MRSA colonization likely the result of high antibiotic concentration in the perigraft tissue. While both types of grafts failed to eradicate the MRSA infection future research with silver-bonded grafts that have an additional antibiotic attached may have a place in the treatment of MRSA infection.

Animals↗
PubMed2002

Infrared spectrometric study of acid-degradable glasses.

The composition of glasses used in glass-ionomer cements affects their leaching behavior and hence the properties of the cement. The aim of this study was to correlate the composition and leaching behavior of these glasses with their infrared absorption characteristics. The wavenumber of the absorption band of the Si-O asymmetric stretching vibration shifts to a higher value with decreasing content of mono- and bivalent cations in the glass. This effect can be ascribed to the influence of these extraneous ions on the glass network order and connectivity. Preferential leaching of these ions induces an increase of asymmetric stretching vibration and a general modification of the band profile. The results can be correlated with the x-ray diffraction characteristics of the glass.

Acetates↗
PubMed1994

Golgi-Colonnier method: correlation of the degree of chromium reduction and pH change with quality of staining.

We examined the role of chromium reduction in the Golgi-Colonnier method, correlating the quality of neuronal impregnation with the levels of hexavalent (CrVI) and trivalent (CrIII) chromium in the tissue and in the chromation fluid (CF). The concentrations of both chromium species were assessed by measuring spectrophotometrically the CrVI before and after oxidizing the sample and by calculating the ratio of CrVI to total chromium (chromium ratio, CrR). The CrR was almost identical in the tissue and the CF, decreasing exponentially during chromation due to a progressive consumption of CrVI to form CrIII. Satisfactory cell impregnation was obtained only when the CrR was 0.45-0.7, regardless of other factors. The CrR values could be accurately predicted by the pH increase of the CF; this increase has proven to be a most reliable criterion to decide the endpoint of the chromation process. The dependence of cell staining on the [CrIII], together with the well-known ability of this species to bridge proteins, suggests that the key event for cell impregnation is the cross-linking of neuronal proteins by CrIII polymers.

Animals↗
PubMedDate not supplied

Long-term use of silver containing nose-drops resulting in systemic argyria.

Generalized argyria is a silver intoxication that results in pigmentation due to deposition of silver in the skin and mucous membranes. Compared to several decades ago, argyria is now relatively rare. We report a case of generalized argyria after continous use of argyrophedrine nosedrops in the last ten years. Argyria should be taken into consideration when a patient presents with a blue-grey discoloration of the skin, particulary in areas exposed to the sun.

Argyria↗
PubMed1990

Deprotection of the S-trimethylacetamidomethyl (Tacm) group using silver tetrafluoroborate: application to the synthesis of porcine brain natriuretic peptide-32 (pBNP-32).

Silver tetrafluoroborate (AgBF4) in trifluoroacetic acid (TFA) has been found to cleave the S-trimethyl-acetamidomethyl (Tacm) group or the S-acetamidomethyl (Acm) group without affecting other functional groups in a peptide chain. A newly isolated porcine brain natriuretic peptide-32 (pBNP-32) was synthesized by the combined use of the S-Tacm group and AgBF4 deprotection. The synthetic pBNP-32 was obtained in better yield by the AgBF4 procedure than by the standard I2 procedure. The synthetic pBNP-32 has the highest chick rectum relaxant activity among the known members of the atrial natriuretic peptide-brain natriuretic peptide (ANP-BNP) families. Somatostatin was also synthesized by the Fmoc-based solid-phase method using S-Tacm and AgBF4. In this synthesis, the recently developed reagent tetrafluoroboric acid (HBF4) was applied to cleave the peptide from the resin.

Acetamides↗
PubMed1990

Synthesis of porcine brain natriuretic peptide-32 using silver tetrafluoroborate as a new deprotecting reagent of the S-trimethylacetamidomethyl group.

Silver tetrafluoroborate (AgBF4) in trifluoroacetic acid (TFA) has been found to cleave the S-trimethylacetamidomethyl (Tacm) group or the S-acetamidomethyl (Acm) group without affecting other functional groups in the peptide chain. Newly isolated porcine brain natriuretic peptide-32 (pBNP-32) was synthesized using AgBF4 and Cys(Tacm) derivatives. The synthetic pBNP-32 had the highest chick rectum relaxant activity among the ANP-BNP families.

Amino Acid Sequence↗
PubMed2002

PEG site infections: a novel use for Actisorb Silver 220.

Any breach in the integrity of the skin, such as occurs in wounds and incisions, and intravascular catheters, can act as a portal for the ingress of microorganisms and thereby predispose the patient to infection. The infection, if unchecked, can put the patient at risk of bacteraemia. We have reviewed the care of percutaneous enterostomal gastrostomy (PEG) sites in our trust hospital and in the local community and have implemented practice guidelines to reduce infection risks. These include protocols for skin care around PEG sites, and the use of an antibacterial dressing - Actisorb Silver 220 - to manage local colonization. The preliminary results of this exercise indicate that patient comfort can be improved, hypergranulation reduced, and methicillin-resistant Staphylococcus aureus colonization and infection eradicated.

Administration, Cutaneous↗
PubMed2006

Is infection in the community a real threat? The example of CAUTI.

Targeting health care associated infections (HCAIs) is a key priority of current health policy. This applies as much to the community as to hospitals, although the latter receive far more media attention. One of the commonest HCAIs in the community is catheter-associated urinary tract infection (CAUTI). Cutting infection rates is a challenge. Many CAUTIs are the result of inappropriate catheterization, often combined with reduced sensitivity of bacteria to antibiotics given prophylactically. The government's rapid reaction task force has recommended use of a silver-alloy coated catheter, but closer surveillance is needed to persuade budget-holders of the cost and clinical benefits of this intervention.

Alloys↗
PubMedDate not supplied

The use of combination treatments and dressings for a traumatic wound.

With demographics, an ageing population and faster hospital discharges against us, district nurses are likely to be faced with more complicated wounds that require specialist attention. With national and local guidelines, the restriction of cost implications, patient compliance and 'best practice' to achieve, the nurse can find the task of choosing the correct course of treatment a daunting one. Nurses must not only consider the patient holistically, assess the wound and the predisposing factors that may be present, but also prescribe an effective treatment while being aware of what effects the treatment may have and be prepared to justify their actions when called to task. This article takes one case study detailing a traumatic wound and follows through the whole assessment and evaluation process to demonstrate how all of these demands were met. Dressings used in the case study are Promogran, Actisorb Silver 220 and Tielle Plus manufactured by Johnson & Johnson.

Aged↗
PubMedDate not supplied

Audit of catheter-associated UTI using silver alloy-coated Foley catheters.

Catheter-associated urinary tract infection (CAUTI) is the most common and most costly healthcare-associated infection, and possibly the most preventable (Salgado et al, 2003). The Cochrane Review of silver alloy-coated Foley catheters concluded that they are successful at reducing the rate of this healthcare-associated infection, which can be potentially fatal (Brosnahan et al, 2004). This article discusses the merits of using the silver alloy-coated Foley catheter in reducing the risk of CAUTI in an acute general hospital. A pre- and post-intervention design was used to audit CAUTI rates. During the pre-intervention period of 10 weeks, the Trust's standard catheters were used and CAUTI rates captured. Silver alloy-coated Foley catheters were introduced and their use monitored for a further period of 10 weeks. A total of 117 newly catheterized patients were actively monitored for signs and symptoms of CAUTI. The audit met and exceeded its aim of reducing the CAUTI rate by 20&. The CAUTI risk rate and device rate fell during the evaluation period. The use of the silver alloy-coated Foley catheters proved to be cost-effective given the recognized additional costs of CAUTI and prolonged in-patient stay (Plowman et al, 1999). Given the results of this audit it is recommended that the silver alloy-coated Foley catheter be the catheter of choice for use with acute patient admissions requiring short-term catheterization.

Adult↗
PubMed2002

Silver. I: Its antibacterial properties and mechanism of action.

Silver products have two key advantages: they are broad-spectrum antibiotics and are not yet associated with drug resistance. This article, the first in a two-part series, describes the main mechanism of action of this metallic element.

Anti-Infective Agents, Local↗