13 research outputs found
Do children with autism acknowledge the influence of mood on behaviour?
We tested whether children with and without high-functioning autism spectrum disorders (HFASD) differ in their understanding of the influence of mood states on behaviour. A total of 122 children with HFASD or typical development were asked to predict and explain the behaviour of story characters during hypothetical social interactions. HFASD and typically developing children predicted at equal rates that mood states likely result in similar valenced behaviour. 'Explicit' descriptions were used to explain predictions more often by children with HFASD than by typically developing children. However, 'implicit' and 'irrelevant' descriptions elicited fewer mood references among HFASD children. Furthermore, they less often referred to the uncertainty of the influence of mood on behaviour, and less often used mood-related explanations, in particular when they had to rely on implicit information. This may indicate a rote- rather than self-generated understanding of emotions in children with HFASD. © SAGE Publications, Inc. 2007
Invasive Propionibacterium acnes infections in a non-selective patient cohort: clinical manifestations, management and outcome
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Purpose
An increasing number of reports suggest that Propionibacterium acnes can cause serious invasive infections. Currently only limited data exist regarding the spectrum of invasive P. acnes infections.
Methods
Non-selective cohort study at a tertiary hospital in the UK over a nine-year-period (2003-2012) investigating clinical manifestations, risk factors, management and outcome of invasive P. acnes infections.
Results
Forty-nine cases were identified; the majority were neurosurgical infections and orthopaedic infections (n=28 and n=15, respectively). Only two cases had no predisposing factors; all neurosurgical and 93.3% of orthopaedic cases had a history of previous surgery and/or trauma. Foreign material was in situ at the infection site in 59.3% and 80.0% of neurosurgical and orthopaedic cases, respectively. All neurosurgical and orthopaedic cases required one or more surgical interventions to treat P. acnes infection, with or without concomitant antibiotic therapy; the duration of antibiotic therapy was significantly longer in the group of orthopaedic cases (median 53 versus 19 days; p=0.0025). All tested P. acnes isolates were susceptible to penicillin, ampicillin and chloramphenicol; only one was clindamycin-resistant.
Conclusions
Neurosurgical and orthopaedic infections account for the majority of invasive P. acnes infections. The majority of cases have predisposing factors, including previous surgery and/or trauma; spontaneous infections are rare. Foreign material is commonly present at the site of infection, indicating that the pathogenesis of invasive P. acnes infections likely involves biofilm formation. Since invasive P. acnes infections are associated with considerable morbidity, further studies are needed to establish effective prevention and optimal treatment strategies
What's on your device?
Decontamination is a combination of processes (including cleaning, disinfection and/or sterilization) used to render a reusable item safe for return to the operating theatre. Critical to this process are the prevention of drying and the implementation of an effective washer-disinfector process commonly utilizing enzymatic or alkaline detergents within an automated cycle. At this stage the choice of the main wash chemistry is crucial. A balance must be obtained between the vigorous removal of often dense contamination and the maintenance of surface integrity and instrument function. However, ineffective cleaning of surgical instruments may be a vector for the transmission of hospital acquired infections and assessment of cleaning efficacy is dependent on the minimal level of detection of the analytical method.Currently, following disinfection, instruments are subjected to visual evaluation often using magnifying/illuminated lenses to detect any evidence of residual soiling of damage whereby instruments are reprocessed or discarded. Although this method is clearly both rapid and simple to perform it undoubtedly suffers from serious issues of variability and sensitivity, in addition to being non-quantitative. Whilst this method readily detects the haem pigment in haemoglobin to levels as low as 10 ?g/cm2, bodily fluids without pigments are more difficult to visualise (REF?). Cerebral spinal fluid (CSF) is both colourless and odourless and has been shown to be a carrier of prion disease infection. Due to the realisation of these facts, European guidelines ISO EN15883 and the British Health Technical Memorandum (HTM) 2030 outline two techniques for the further assessment of instrument cleanliness: the Biuret and Ninhydrin test kits. Both require prior swabbing of an instrument surface to obtain a result and are based on colorimetric chemical changes although the methodologies behind these reactions differ. The Biuret technique utilises the reaction of copper ions with peptide bonds under alkaline conditions to form a complex which is then added to bicinchoninic acid (BCA) causing a purple colour change that can be readily visualised. The Ninhydrin test kit uses a reaction of amino acids, peptides and proteins with 1, 2, 3-indantrione monohydrate followed by a 30 min incubation at 110 ºC, although a Ninhydrin gel kit can also be used requiring incubation at only 57 ºC for 60 min. However, a recent study has shown that both the Biuret and Ninhydrin tests suffer from poor sensitivity, demonstrating a minimum level of detection by 75 % of volunteers of 6.7 ?g and 9.25 ?g of protein, respectively, on surgical grade stainless steel tokens1. The authors suggests that, as a result, large amounts of protein (up to 6.5 ?g) may remain undetected, therefore seriously underestimating levels of residual contamination. In practice, sensitivity is likely to be reduced further due to the difficulty in swabbing areas of surgical instruments such as teeth and box joints where contamination is likely to be harder to remove for analysis
Application of a fluorescent dual stain to assess decontamination of tissue protein and prion amyloid from surgical stainless steel during simulated washer-disinfector cycles
Current World Health Organization guidelines pertaining to the reprocessing of surgical instruments in the face of potential iatrogenic transmission of Creutzfeldt-Jakob disease (iCJD) are incompatible for the vast majority of devices. This has led to the advent of a range of new decontamination measures. Even without the implementation of these new procedures, the incidence of proven iCJD through surgery remains low. In this study, existing decontamination processes in sterile service departments have been evaluated using simulated washer-disinfector cycles on surgical grade stainless steel wires inoculated with ME7 scrapie homogenate. The consequence of varying the soil drying times and choice of cycle pre-treatment on prion removal were evaluated. Assessment of residual contamination at each cycle phase was carried out with the application of a sensitive fluorescent staining procedure to identify both total protein and prion-associated amyloid. The study confirmed that immediate reprocessing following contamination was beneficial during the pre-treatment phase with either an enzymatic or pre-soak wetting agent. Final total protein levels at the end of the cycles, were not significantly different from those where the soil was allowed to dry. In addition, cycles involving a pre-treatment with either an enzymatic cleaner or pre-soak, whether the soil was allowed to dry or not, showed complete removal of detectable prion amyloid. The results suggest that current decontamination procedures, combined with immediate processing of surgical instruments, have the potential to be highly effective alone at reducing the risk of surgical transmission of CJ
Cold water cleaning of brain proteins, biofilm and bone - harnessing an ultrasonically activated stream
In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from surgical stainless steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications
Removal of dental biofilms with an ultrasonically-activated water stream
Acidogenic bacteria within dental plaque biofilms are the causative agents of caries. Consequently, maintenance of a healthy oral environment with efficient biofilm removal strategies is important to limit caries, as well as halt progression to gingivitis and periodontitis. Recently, a novel cleaning device has been described using an ultrasonically activated stream (UAS) to generate a cavitation cloud of bubbles in a freely flowing water stream that has demonstrated the capacity to be effective at biofilm removal. In this study, UAS was evaluated for its ability to remove biofilms of the cariogenic pathogen Streptococcus mutans UA159, as well as Actinomyces naeslundii ATCC 12104 and Streptococcus oralis ATCC 9811, grown on machine-etched glass slides to generate a reproducible complex surface and artificial teeth from a typodont training model. Biofilm removal was assessed both visually and microscopically using high-speed videography, confocal scanning laser microscopy (CSLM), and scanning electron microscopy (SEM). Analysis by CSLM demonstrated a statistically significant 99.9% removal of S. mutans biofilms exposed to the UAS for 10 s, relative to both untreated control biofilms and biofilms exposed to the water stream alone without ultrasonic activation (P < 0.05). The water stream alone showed no statistically significant difference in removal compared with the untreated control (P = 0.24). High-speed videography demonstrated a rapid rate (151 mm2 in 1 s) of biofilm removal. The UAS was also highly effective at S. mutans, A. naeslundii, and S. oralis biofilm removal from machine-etched glass and S. mutans from typodont surfaces with complex topography. Consequently, UAS technology represents a potentially effective method for biofilm removal and improved oral hygiene
Cold water cleaning of brain proteins, biofilm and bone - harnessing an ultrasonically activated stream
In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from surgical stainless steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications.</span
Cephalosporin nitric oxide-donor prodrug DEA-C3D disperses biofilms formed by clinical cystic fibrosis isolates of Pseudomonas aeruginosa
open access articleObjectives: The cephalosporin nitric oxide (NO)-donor prodrug DEA-C3D (DiEthylAmin-Cephalosporin-3’- Diazeniumdiolate) has been showed to initiate the dispersal of biofilms formed by Pseudomonas aeruginosa laboratory strain PAO1. In this study, we investigated whether DEA-C3D disperses biofilms formed by clinical cystic fibrosis isolates of P. aeruginosa and its effect in combination with two anti-pseudomonal antibiotics, tobramycin and colistin, in vitro.
Methods: -lactamase-triggered release of NO from DEA-C3D was confirmed using a gas-phase chemiluminescence detector. MICs against P. aeruginosa clinical isolates were measured using the broth microdilution method. A crystal violet staining technique and confocal laser scanning microscopy were used to evaluate the effects of DEA-C3D on P. aeruginosa biofilms alone and in combination with tobramycin and colistin.
Results: DEA-C3D was confirmed to selectively release NO in response to contact with bacterial -lactamase. Despite lacking direct, cephalosporin/-lactam-based antibacterial activity, DEA-C3D was able to disperse biofilms formed by three P. aeruginosa clinical isolates. Confocal microscopy revealed that DEA-C3D in combination with tobramycin produces similar reductions in biofilm to DEA-C3D alone, whereas the combination with colistin causes near complete eradication of P. aeruginosa biofilms in vitro.
Conclusions: DEA-C3D is effective in dispersing biofilms formed by multiple clinical isolates of P. aeruginosa and could hold promise as a new adjunctive therapy to patients with CF