1,720,960 research outputs found
Current risk of iatrogenic Creutzfeld–Jakob disease in the UK: efficacy of available cleaning chemistries and reusability of neurosurgical instruments
No full textThe initial cleaning of reusable surgical devices is critical to ensure the efficacy of the subsequent sterilisation process. Transmissible spongiform encephalopathies (TSEs) are incurable and fatal neurodegenerative diseases apparently transmitted simply by the absorption or ingestion of self-aggregating protease-resistant prions (PrP(Sc)), which are very resilient to most standard cleaning chemistries and heat-based decontamination techniques. Therefore there is a risk of iatrogenic transmission from reusable surgical devices if these are allowed to retain potentially infectious material after standard reprocessing through sterile service departments (SSDs). We aimed to assess the current state of surgical instrument decontamination with the collaboration of anonymous SSDs. Surgical stainless steel surfaces were spiked with prion-infected brain homogenates, and episcopic differential interference contrast/epifluorescence (EDIC/EF) microscopy was applied to quantify the amount of residual prion amyloid and other proteins remaining after decontamination with enzymatic cleaners currently employed by SSDs. Reusable instruments deemed 'clean and ready to use' were also stained for comparison with our findings in the laboratory. All cleaning chemistries were only partially effective under the recommended conditions. More importantly, PrP(Sc) constituted the main fraction of the remaining contamination left on these surfaces. The neurosurgery instruments also harboured amyloid and general protein contamination. This study shows that currently marketed cleaning chemistries and recent decontamination protocols do not completely suppress the threat from iatrogenic CJD. These findings should be taken into account for risk assessment purposes and re-evaluating instrument handling and decontamination practices
Adsorption of prion and tissue proteins to surgical stainless steel surfaces and the efficacy of decontamination following dry and wet storage conditions
No full textIatrogenic transmission of the infectious prion protein (PrP(Sc)) is a potential threat due to its resistance to many chemical and enzymatic decontamination protocols and its strong adhesive properties to stainless steel. The conditions in which surgical instruments are handled during and after surgery may affect the level of tissue protein, prion attachment and the efficacy of subsequent decontamination regimes. This study investigated the adhesion of tissue protein and prion-associated amyloid to surgical stainless steel with respect to time and various storage conditions, and the subsequent outcome on the efficacy of enzymatic cleaning chemistries. Surfaces were contaminated with ME7-infected brain homogenate and left to dry between 0 and 120 min at room temperature or 24 h, in dry or moist conditions. Residual contamination before and after cleaning was visualised using sensitive fluorescent staining and episcopic differential interference contrast/epifluorescence microscopy. Longer drying times increased both protein and prion amyloid adsorption and affected the efficacy of the cleaning chemistries tested. A moist environment post-contamination significantly reduced the attachment of both protein and prion amyloid to the surgical stainless steel surface. Maintaining moist conditions could potentially improve the subsequent decontamination of reusable surgical instruments, also reducing process time and cos
A cold water, ultrasonically activated stream efficiently removes proteins and prion-associated amyloid from surgical stainless steel: ultrasonic water stream for surgical decontamination
No full textBackground: Sterile service department decontamination procedures for surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which uses a low pressure ultrasonically activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants. Aim: To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from surgical stainless steel surfaces. Methods: Test surfaces were contaminated with 22L, ME7 or 263K prion-infected brain homogenates. The surfaces were treated with the ultrasonically activated water stream for contact times of 5 and 10 s. Residual proteinaceous and amyloid contamination were quantified using sensitive microscopic analysis, and immunoblotting was used to characterize the eluted prion residues before and after treatment with the ultrasonically activated stream. Findings: Efficient removal of the different prion strains from the surgical stainless steel surfaces was observed, and reduced levels of protease-susceptible and -resistant prion protein was detected in recovered supernatant. Conclusion: This study demonstrated that an ultrasonically activated stream has the potential to be a cost-effective solution to improve current decontamination practices and has the potential to reduce hospital-acquired infections.</p
Doped diamond-like carbon coatings for surgical instruments reduce protein and prion-amyloid biofouling and improve subsequent cleaning
No full textDoped diamond-like carbon (DLC) coatings offer potential antifouling surfaces against microbial and protein attachment. In particular, stainless steel surgical instruments are subject to tissue protein and resilient prion protein attachment, making decontamination methods used in sterile service departments ineffective, potentially increasing the risk of iatrogenic Creutzfeldt-Jakob disease during surgical procedures. This study examined the adsorption of proteins and prion-associated amyloid to doped DLC surfaces and the efficacy of commercial cleaning chemistries applied to these spiked surfaces, compared to titanium nitride coating and stainless steel. Surfaces inoculated with ME7-infected brain homogenate were visualised using SYPRO Ruby/Thioflavin T staining and modified epi-fluorescence microscopy before and after cleaning. Reduced protein and prion amyloid contamination was observed on the modified surfaces and subsequent decontamination efficacy improved. This highlights the potential for a new generation of coatings for surgical instruments to reduce the risk of iatrogenic CJD infection.<br/
Bubbles vs biofilms: a novel method for the removal of marine biofilms attached on antifouling coatings using an ultrasonically activated water stream
No full textThe accumulation of marine organisms on a range of manmade surfaces, termed biofouling, has proven to be the Achilles’s heel of the shipping industry. Current antifouling coatings, such as Foul Release Coatings (FRCs), only partially inhibit biofouling, since biofilms remain a major issue. Mechanical ship hull cleaning is commonly employed to remove biofilms, but these methods tend to damage the antifouling coating and often do not result in full removal. Here, we report the effectiveness of biofilm removal from FRCs through a novel cleaning device that uses an Ultrasonically Activated Stream (UAS). In this device, ultrasound enhances the cleaning properties of microbubbles in a freely flowing stream of water. The UAS was applied on two types of commercial FRCs which were covered with biofilm growth following twelve days immersion in the marine environment. Biofilm removal was quantified in terms of reduction in biovolume and surface roughness, both measured using an optical profilometer, which were then compared with similar measurements after cleaning with a non-ultrasonically activated water stream. It was found that the UAS significantly improves the cleaning capabilities of a water flow, up to the point where no detectable biofilm remained on the coating surfaces. Overall biofilm surface coverage was significantly lower on the FRC coatings cleaned with the UAS system when compared to the coatings cleaned with water or not cleaned at all. When biofilm biomass removal was investigated, the UAS system resulted in significantly lower biovolume values even when compared to the water cleaning treatment with biovolume values close to zero. Remarkably, the surface roughness of the coatings after cleaning with the UAS was found to be comparable to that of the blank, non-immersed coatings, illustrating that the UAS did not damage the coatings in the process
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A proof‐of‐concept study of the removal of early and late phase biofilm from skin wound models using a liquid acoustic stream
No full textChronic wounds fail to progress through the normal stages of healing, with the largest remediable cause of chronicity being presence of a multi-species biofilm. Removal of biofilm from the wound environment is central to wound care. A device for mechanically removing biofilms from wounds has been devised. The removal is caused by small-scale liquid currents and shear, generated by acoustically activated microscopic air bubbles. These bubbles and acoustic waves are delivered onto the wound by a gentle liquid stream, allowing cleaning in situ and removal of debris in the run-off liquid. We have investigated if this liquid acoustic wound stream (LAWS) can remove bacterial biofilm from soft biological wound models and studied the effect of LAWS on the cellular tissues of the substrate. LAWS will efficiently remove early Pseudomonas aeruginosa biofilm from an artificial wound in a pig's trotter, 24 hours-mature biofilm of P. aeruginosa from a pre-wounded human full thickness skin model (EpiDerm FT), and 3-day mature biofilm of P. aeruginosa or Staphylococcus aureus from a porcine skin explant. Histological examinations of uninfected EpiDerm models that had been treated by LAWS and then stained with Haematoxylin and Eosin, demonstrated no damage to the human tissue, and wound diameter was smaller in the treated skin models compared with untreated samples. Immunofluorescence staining for cytokeratin 14 showed that keratinocytes had migrated further across the wound in the uninfected samples treated by LAWS. We discuss the implications for wound healing and propose further laboratory and clinical studies to demonstrate the removal of biofilm from patients with chronic leg ulcers and the impact on healing.</p
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