Radiation Dose Reduction for Computed Tomography Localizer Radiography Using an Ag Additional Filter.

OBJECTIVE: This study aimed to assess the potential of an Ag additional filter attached to the bow tie filter of a computed tomography (CT) scanner to reduce the radiation dose in CT localizer radiography. METHODS: Radiation doses in CT localizer radiography with Cu and Ag additional filters were evaluated based on dose measurements and Monte Carlo simulations. Image quality evaluations of an adult torso phantom were performed, and the automatic exposure control performance was evaluated in terms of the water-equivalent thickness estimated from CT localizer radiographs. RESULTS: With the Ag additional filter, effective doses were approximately 72% to 75% lower than those with the Cu additional filter. The image quality and water-equivalent thickness with the Ag additional filter were similar to those with the Cu additional filter. CONCLUSIONS: The Ag additional filter helped significantly reduce radiation doses in CT localizer radiography while maintaining image quality and performance.

[Alteration of white rats brain tissue inducted by assessment of silver nanocomposite incapsulated in polymer matrix].

The paper present experimental materials of intragastric administration of silver nanoparticles encapsulated in polymer matrix of arabinogalactan by white outbred male rats. Animals were injected "pure" arabinogalactan and colloid silver solution containing silver macroform separately for comparison. Research provided data about status of brain tissue at the impact of these substances on organism. Histological analysis revealed the presence of a pathological process, character and intensity of which varied depending on the type of injected material. Pathological process under the influence of silver-arabinogalactan characterized by appearance in brain tissue of perivascular edema and development of acute inflammation in formation of glial scars, swelling of vascular bundles in sum.

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital and incurs significant costs for health-care providers such as the UK NHS. Many preventative strategies and measures have been introduced to minimise CAUTI risk, including the use of antimicrobial catheters. However, there is considerable uncertainty regarding their usefulness in terms of reducing symptomatic CAUTI, and whether or not they are cost-effective. OBJECTIVES: Do antimicrobial catheters reduce the rate of symptomatic urinary tract infection (UTI) during short-term hospital use and is their use cost-effective for the UK NHS? DESIGN: A pragmatic multicentre UK randomised controlled trial comparing three catheters as they would be used in the UK NHS: antimicrobial-impregnated (nitrofurazone) and antiseptic-coated (silver alloy) catheters with the standard polytetrafluoroethylene (PTFE)-coated catheters. Economic evaluation used a decision model populated with data from the trial. Sensitivity analysis was used to explore uncertainty. SETTING: Relevant clinical departments in 24 NHS hospitals throughout the UK. PARTICIPANTS: Adults requiring temporary urethral catheterisation for a period of between 1 and 14 days as part of their care, predominantly as a result of elective surgery. INTERVENTIONS: Eligible participants were randomised 1 : 1 : 1 to one of three types of urethral catheter in order to make the following pragmatic comparisons: nitrofurazone-impregnated silicone catheter compared with standard PTFE-coated latex catheter; and silver alloy-coated hydrogel latex catheter compared with standard PTFE-coated latex catheter. MAIN OUTCOME MEASURES: The primary outcome for clinical effectiveness was the incidence of UTI at any time up to 6 weeks post randomisation. This was defined as any symptom reported during catheterisation, up to 3 days or 1 or 2 weeks post catheter removal or 6 weeks post randomisation combined with a prescription of antibiotics, at any of these times, for presumed symptomatic UTI. The primary economic outcome was incremental cost per quality-adjusted life-year (QALY). Health-care costs were estimated from NHS sources with QALYs calculated from participant completion of the European Quality of Life-5 Dimensions (EQ-5D). RESULTS: Outcome analyses encompassed 6394 (90%) of 7102 participants randomised. The rate of symptomatic UTI within 6 weeks of randomisation was 10.6% in the nitrofurazone group (n = 2153; -2.1% absolute risk difference), 12.5% in the silver alloy group (n = 2097; -0.1% absolute risk difference) and 12.6% in the PTFE group (n = 2144). The effect size {odds ratio (OR) [97.5% confidence interval (CI)]} was 0.82 (97.5% CI 0.66 to 1.01) for nitrofurazone (p = 0.037) and 0.99 (97.5% CI 0.81 to 1.22) for silver alloy (p = 0.92) catheters. The nitrofurazone catheters were more likely to cause discomfort during use and on removal. The primary economic analysis suggested that nitrofurazone-impregnated catheters would be, on average, the least costly (> £7 less than PTFE) and most effective option at current NHS prices. There was a 73% chance that nitrofurazone would be cost saving and an 84% chance that the incremental cost per QALY would be < £30,000. At the trial price (£6.46), silver alloy catheters were very unlikely to be cost-effective. These results were unchanged in sensitivity analyses, although when the length of stay cost was excluded the incremental cost per QALY for nitrofurazone against PTFE was £28,602. CONCLUSIONS: The trial estimate of clinical effectiveness for nitrofurazone-impregnated catheters was less than the pre-specified minimum absolute risk difference that we considered important (-3.3%), and the surrounding CI included zero, indicating that any reduction in catheter-associated UTI was uncertain. Economic analysis, although associated with uncertainty, suggested that nitrofurazone-impregnated catheters may be cost-effective for the NHS. The trial ruled out the possibility that silver alloy-coated catheters might reach the pre-set degree of clinical effectiveness and that their use was unlikely to be cost-effective. These findings should be considered by patients, clinicians and health-care policy-makers to determine whether or not a change in practice is worthwhile. Future research should be aimed at determining the minimum clinically important difference in terms of CAUTI prevention in comparative trials, and to identify reliable methods which can detect the impact of the intervention on quality of life and other drivers of cost, when the intervention is a subsidiary part of overall treatment plans.

Whole cell based electrical impedance sensing approach for a rapid nanotoxicity assay.

A whole cell based biosensor for rapid real-time testing of human and environmental toxicity of nanoscale materials is reported. Recent studies measuring nanoparticle cytotoxicity in vitro provide a final measurement of toxicity to a cell culture overlooking the ongoing cytotoxic effects of the nanoparticles over the desired timeframe. An array biosensor capable of performing multiple cytotoxicity assays simultaneously was designed to address the need for a consistent method to measure real-time assessments of toxicity. The impedimetric response of human lung fibroblasts (CCL-153) and rainbow trout gill epithelial cells (RTgill-W1) when exposed to gold and silver nanoparticles (AuNPs, AgNPs), single walled carbon nanotubes (SWCNTs) and cadmium oxide (CdO) was tested. Exposure to CdO particles exhibited the fastest rate of cytotoxicity and demonstrated the biosensor's ability to monitor toxicity instantaneously in real time. Advantages of the present method include shorter run times, easier usage, and multi-sample analysis leading to a method that can monitor the kinetic effects of nanoparticle toxicity continuously over a desired timeframe.

Assessment of functional changes in nanoparticle-exposed neuroendocrine cells with amperometry: exploring the generalizability of nanoparticle-vesicle matrix interactions.

Using two of the most commonly synthesized noble metal nanoparticle preparations, citrate-reduced Au and Ag, the impacts of short-term accidental nanoparticle exposure are examined in primary culture murine adrenal medullary chromaffin cells. Transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Alamar Blue viability studies revealed that nanoparticles are taken up by cells but do not decrease cell viability within 48 hours of exposure. Carbon-fiber microelectrode amperometry (CFMA) examination of exocytosis in nanoparticle-exposed cells revealed that nanoparticle exposure does lead to decreased secretion of chemical messenger molecules, of up to 32.5% at 48 hours of Au exposure. The kinetics of intravesicular species liberation also slows after nanoparticle exposure, between 30 and 50% for Au and Ag, respectively. Repeated stimulation of exocytosis demonstrated that these effects persisted during subsequent stimulations, meaning that nanoparticles do not interfere directly with the vesicle recycling machinery but also that cellular function is unable to recover following vesicle content expulsion. By comparing these trends with parallel studies done using mast cells, it is clear that similar exocytosis perturbations occur across cell types following noble metal nanoparticle exposure, supporting a generalizable effect of nanoparticle-vesicle interactions.

Is copper-silver ionisation safe and effective in controlling legionella?

Copper-silver ionisation is gaining popularity worldwide as a water disinfection method. We review the literature that supports the effectiveness and safety of the copper-silver ionisation pertaining to legionella control in water distribution systems. A search between January 1997 and January 2007 was conducted in relevant health databases: Medline, Embase, NHS CRD, Cochrane Library Plus, Web of Knowledge, IME (Spanish Medical Index) and IBECS (Health Sciences Bibliographic Index). Ten published studies were selected according to inclusion and exclusion criteria previously established; most of these were experimental. Legionella levels decrease with the application of any of the procedures used in these studies and the procedures can be combined to obtain better outcomes. No studies containing an economic evaluation were found. We conclude that copper-silver ionisation is an effective method to control legionella, bearing in mind that eradication cannot be achieved by any method in isolation. Maintaining high temperatures in the water system can maximise effectiveness of the method. Copper-silver appears to be safe, as long as ion levels are monitored and kept within international recommended levels. More studies with concurrent control group, long follow-up and economic evaluation are required to properly assess this procedure.

Randomized clinical study of Hydrofiber dressing with silver or silver sulfadiazine in the management of partial-thickness burns.

This prospective, randomized study compared protocols of care using either AQUACEL Ag Hydrofiber (ConvaTec, a Bristol-Myers Squibb company, Skillman, NJ) dressing with silver (n = 42) or silver sulfadiazine (n = 42) for up to 21 days in the management of partial-thickness burns covering 5% to 40% body surface area (BSA). AQUACEL Ag dressing was associated with less pain and anxiety during dressing changes, less burning and stinging during wear, fewer dressing changes, less nursing time, and fewer procedural medications. Silver sulfadiazine was associated with greater flexibility and ease of movement. Adverse events, including infection, were comparable between treatment groups. The AQUACEL Ag dressing protocol tended to have lower total treatment costs (Dollars 1040 vs. Dollars 1180) and a greater rate of re-epithelialization (73.8% vs 60.0%), resulting in cost-effectiveness per burn healed of Dollars 1,409.06 for AQUACEL Ag dressing and Dollars 1,967.95 for silver sulfadiazine. A protocol of care with AQUACEL(R) Ag provided clinical and economic benefits compared with silver sulfadiazine in patients with partial-thickness burns.

In vitro longitudinal assessment of coronal discoloration from endodontic sealers.

A major cause of tooth discoloration may be sealer remnants in the chamber. The objective of this study was to evaluate, longitudinally, coronal discoloration from four sealers. Extracted premolars were sectioned in the coronal third of the root. The chamber contents were removed and instrumentation was via the canal. The following sealers were bulk introduced into the chamber: AH26, Kerr Pulp Canal Sealer, Roths 801 (nonstaining), and Sealapex. The apical access was sealed with white sticky wax. Teeth were maintained in a moist environment at 37 degrees C. Initial (immediate pretreatment) digital images of the teeth were made for base line comparison. Subsequent images were at 1-, 3-, 9-, and 12-month intervals. Then images were mixed and descriptively evaluated blindly by trained evaluators. Discoloration was induced by the four sealers, with slight to moderate visible changes that increased through 12 months. There was slightly more discoloration with AH26 and Kerr Pulp Canal Sealer. In conclusion discoloration induced by the endodontic sealers produced slight to moderate and generally progressive discoloration over 12 months.