Effective cleaning and decontamination of the internal air and water channels, heads and head-gears of multiple contra-angle dental handpieces using an enzymatic detergent and automated washer-disinfection in a dental hospital setting.

BACKGROUND: Dental handpieces (DHPs) are reusable invasive medical devices that must be cleaned, decontaminated, lubricated and steam sterilized after use. DHPs have a complex internal design including narrow channels, contamination of which can compromise sterilization. DHPs are not designed for routine disassembly, making cleaning/decontamination efficacy difficult to monitor. Washer-disinfection is the preferred method of decontaminating DHPs, but few studies have investigated its direct effectiveness at reducing microbial contamination internally. AIMS: To use contra-angle DHPs as a model system to investigate the effectiveness of washer-disinfection at reducing microbial contamination of internal components of multiple DHPs. METHODS: The air and water channels and heads of 10 disassembled contra-angle DHPs (BienAir, Biel/Bienne, Switzerland) were inoculated separately with 108 colony forming units (cfu) of Pseudomanas aeruginosa, Staphylococcus aureus, Enterococcus hirae or Candida albicans in the presence of 0.3% bovine serum albumin (BSA) (clean conditions), 3.0% BSA or 10% artificial test soil (dirty conditions). After reassembly, all 10 DHPs underwent washer-disinfection simultaneously in a Míele (Míele Ireland Ltd., Dublin, Ireland) PG8528 washer-disinfector and were tested for reductions in micro-organisms and protein. Additional experiments were undertaken with three lubricated DHPs inoculated with S. aureus and 10% test soil. All experiments were repeated in triplicate. FINDINGS: On average, an approximate 5 log or greater reduction in microbial cfu and a >93% reduction in protein from DHP heads and channels was consistently recorded following washer-disinfection for all DHPs under all conditions tested. CONCLUSIONS: The internal components of multiple DHPs can be effectively cleaned and decontaminated by washer-disinfection.

How repeatable is CTmax within individual brook trout over short- and long-time intervals?

As stream temperatures increase due to factors such as heated runoff from impervious surfaces, deforestation, and climate change, fish species adapted to cold water streams are forced to move to more suitable habitat, acclimate or adapt to increased thermal regimes, or die. To estimate the potential for adaptation, a (within individual) repeatable metric of thermal tolerance is imperative. Critical thermal maximum (CTmax) is a dynamic test that is widely used to measure thermal tolerance across many taxa and has been used in fishes for decades, but its repeatability in most species is unknown. CTmax tests increase water temperature steadily over time until loss of equilibrium (LOE) is achieved. To determine if CTmax is a consistent metric within individual fish, we measured CTmax on the same lab-held individually-marked adult brook trout Salvelinus fontinalis at three different times (August & September 2016, September 2017). We found that CTmax is a repeatable trait (Repeatability ±â€¯S.E.: 0.48 ±â€¯0.14). CTmax of individuals males was consistent over time, but the CTmax of females increased slightly over time. This result indicates that CTmax is a robust, repeatable estimate of thermal tolerance in a cold-water adapted fish.

Mechanisms of transport of H+, Na+ and K+, across the distal gastric caecum of larval Aedes aegypti.

Measured changes in ion fluxes, transepithelial potential (TEP) and basolateral membrane potential (Vb) in response to ion transporter inhibitors were used to assess the mechanisms of transport of H+, Na+ and K+, across the distal gastric caecum of larval Aedes aegypti, a vector of yellow fever. Preparations were stimulated with 5-hydroxytryptamine (5-HT, 10-6 M) in order to maintain stable rates of H+, Na+, and K+ transport across the distal caecum. Transepithelial potential (TEP), basolateral membrane potential (Vb), and H+, Na+ and K+ fluxes all declined after the addition of a vacuolar-type H+-ATPase (VA) inhibitor, n-ethlymaleimide (NEM), consistent with a primary role for VA in energizing ion transport across the distal gastric caecum. Amiloride also inhibited H+, Na+, and K+ fluxes, consistent with an apically expressed VA that is coupled to a cation:H+ antiporter (AeNHE8), analogous to the coupling of apical VA and cation:nH+ antiporter in Malpighian tubules. A working model of transport of H+, Na+ and K+ across the distal gastric caecum proposes that coupling of VA and AeNHE8 in the apical membrane leads to the removal of intracellular Na+ or K+, thus creating favourable ion gradients to promote the activity of two transporters in the basal membrane, cation:H+ antiporter (AeNHE3) and a bumetanide-sensitive cation chloride cotransporter (CCC).

Effect of non-vitamin-K oral anticoagulants on stroke severity compared to warfarin: a meta-analysis of randomized controlled trials.

BACKGROUND AND PURPOSE: In addition to lowering stroke risk, warfarin use is also associated with reduced stroke severity in patients with atrial fibrillation and acute ischaemic stroke. It was sought to determine whether the effect of non-vitamin-K oral anticoagulants (NOACs), compared to warfarin, differed by stroke severity. METHODS: Phase III randomized controlled trials with participants who were randomized to receive NOACs or warfarin for stroke prevention in the setting of non-valvular atrial fibrillation were identified. Stroke was classified into two categories, fatal or disabling stroke and non-disabling stroke, and meta-analyses were completed for both outcomes and for comparative case fatality of stroke amongst trials. RESULTS: Five randomized controlled trials met our inclusion criteria. In clinical trials evaluating the NOACs usually prescribed in clinical practice (four trials), acute stroke was reported in 1403 (1.86%) participants, 787 (1.04%) in the NOAC group [386 (0.51%) fatal or disabling, 401 (0.53%) non-disabling] and 616 (0.82%) in the warfarin group [367 (0.49%) fatal or disabling, 249 (0.33%) non-disabling]. On meta-analysis NOACs were significantly superior to warfarin for fatal or disabling stroke (odds ratio [OR] 0.77; 95% confidence interval [CI] 0.66-0.89, I2  = 21%) and non-disabling stroke (OR 0.85; 95% CI 0.73-0.98, I2  = 2%). The case fatality of stroke was no different between groups (OR 0.90, 95% CI 0.75-1.13, I2  = 0%), but the point estimate favoured NOACs. CONCLUSION: In phase III trials of NOACs, for prevention of stroke in atrial fibrillation, NOACs are associated with a lower risk of both fatal/disabling and non-disabling stroke compared to warfarin.

Whole-genome sequencing identifies highly related Pseudomonas aeruginosa strains in multiple washbasin U-bends at several locations in one hospital: evidence for trafficking of potential pathogens via wastewater pipes.

BACKGROUND: Hand washbasin U-bends have increasingly been associated with nosocomial outbreaks by Gram-negative bacteria, including Pseudomonas aeruginosa which is virtually ubiquitous in U-bends. Wastewater networks servicing U-bends are potential highways for trafficking pathogenic bacteria. AIM: To use P. aeruginosa to investigate trafficking of bacteria between hospital washbasin U-bends. METHODS: Twenty-five washbasin U-bends in five locations in Dublin Dental University Hospital (DDUH) were investigated for trafficking of P. aeruginosa: 10 in Clinic 2 (C2), 10 in the Accident & Emergency Department (A&E) and five in three other locations. In addition, washbasin tap samples (N=80) and mains and tap water samples (N=72) were cultured for P. aeruginosa. Selected P. aeruginosa isolates recovered over 29 months underwent whole-genome sequencing, and relatedness was interpreted using whole-genome multi-locus sequence typing and pairwise single nucleotide polymorphism (SNP) analysis. FINDINGS: P. aeruginosa was recovered from all U-bends but not from taps or water. Eighty-three U-bend isolates yielded 10 sequence types (STs), with ST560 and ST179 from A&E, C2 and two other locations predominating (70%). ST560 was also recovered from a common downstream pipe. Isolates within ST560 and ST179 were highly related regardless of source. ST560 was divided into Cluster I (N=25) and Cluster II (N=2) with average allelic differences and SNPs of three and zero, and two and five, respectively. The 31 ST179 isolates exhibited an average allelic difference and SNPs of three and 12, respectively. CONCLUSION: Highly related P. aeruginosa strains were identified in multiple U-bends in several DDUH locations, indicating trafficking via the wastewater network.

Minimizing microbial contamination risk simultaneously from multiple hospital washbasins by automated cleaning and disinfection of U-bends with electrochemically activated solutions.

BACKGROUND: Outbreaks of infection associated with microbial biofilm in hospital hand washbasin U-bends are being reported increasingly. In a previous study, the efficacy of a prototype automated U-bend decontamination method was demonstrated for a single non-hospital pattern washbasin. It used two electrochemically activated solutions (ECA) generated from brine: catholyte with detergent properties and anolyte with disinfectant properties. AIM: To develop and test a large-scale automated ECA treatment system to decontaminate 10 hospital pattern washbasin U-bends simultaneously in a busy hospital clinic. METHODS: A programmable system was developed whereby the washbasin drain outlets, U-bends and proximal wastewater pipework automatically underwent 10-min treatments with catholyte followed by anolyte, three times weekly, over five months. Six untreated washbasins served as controls. Quantitative bacterial counts from U-bends were determined on Columbia blood agar, Reasoner's 2A agar and Pseudomonas aeruginosa selective agar following treatment and 24 h later. FINDINGS: The average bacterial densities in colony-forming units/swab from treated U-bends showed a >3 log reduction compared with controls, and reductions were highly significant (P<0.0001) on all media. There was no significant increase in average bacterial counts from treated U-bends 24 h later on all media (P>0.1). P. aeruginosa was the most prevalent organism recovered throughout the study. Internal examination of untreated U-bends using electron microscopy showed dense biofilm extending to the washbasin drain outlet junction, whereas treated U-bends were free from biofilm. CONCLUSION: Simultaneous automated treatment of multiple hospital washbasin U-bends with ECA consistently minimizes microbial contamination and thus the associated risk of infection.

Elimination of biofilm and microbial contamination reservoirs in hospital washbasin U-bends by automated cleaning and disinfection with electrochemically activated solutions.

BACKGROUND: Washbasin U-bends are reservoirs of microbial contamination in healthcare environments. U-Bends are constantly full of water and harbour microbial biofilm. AIM: To develop an effective automated cleaning and disinfection system for U-bends using two solutions generated by electrochemical activation of brine including the disinfectant anolyte (predominantly hypochlorous acid) and catholyte (predominantly sodium hydroxide) with detergent properties. METHODS: Initially three washbasin U-bends were manually filled with catholyte followed by anolyte for 5min each once weekly for five weeks. A programmable system was then developed with one washbasin that automated this process. This U-bend had three cycles of 5min catholyte followed by 5min anolyte treatment per week for three months. Quantitative bacterial counts from treated and control U-bends were determined on blood agar (CBA), R2A, PAS, and PA agars following automated treatment and on CBA and R2A following manual treatment. FINDINGS: The average bacterial density from untreated U-bends throughout the study was >1×10(5) cfu/swab on all media with Pseudomonas aeruginosa accounting for ∼50% of counts. Manual U-bend electrochemically activated (ECA) solution treatment reduced counts significantly (<100cfu/swab) (P<0.01 for CBA; P<0.005 for R2A). Similarly, counts from the automated ECA-treatment U-bend were significantly reduced with average counts for 35 cycles on CBA, R2A, PAS, and PA of 2.1±4.5 (P<0.0001), 13.1±30.1 (P<0.05), 0.7±2.8 (P<0.001), and 0 (P<0.05) cfu/swab, respectively. P. aeruginosa was eliminated from all treated U-bends. CONCLUSION: Automated ECA treatment of washbasin U-bends consistently minimizes microbial contamination.

Attitudes to outcomes measured in clinical trials of cardiovascular prevention.

BACKGROUND: Selecting outcome measures in cardiovascular prevention trials should be informed by their importance to selected populations. Major vascular event outcomes are usually prioritized in these trials with considerably less attention paid to cognitive and functional outcomes. AIM: To examine views on importance of outcome measures used in clinical trials. DESIGN: Cross-sectional survey. METHODS: Of 367 individuals approached, 280 (76%) participated: outpatients attending cardiovascular prevention clinics (n = 97), active retirement groups members (n = 75), medical students (n = 108). Participants were asked to rank, in order of importance, outcome measures, which may be included in cardiovascular prevention trials. Results were compared between two groups: <65s (n = 157) and ≥65s (n = 104). RESULTS: When asked what outcomes were most important to measure in cardiovascular prevention trials, respondents reported: death (31.6%) stroke (28.5%), dementia (26.9%), myocardial infarction (MI) (7.9%) and requiring nursing home (NH) care (5.1%). When asked the most relevant outcomes regarding successful ageing respondents reported; maintaining independence (32.4%), avoiding major illness (24.3%), good family life (23.6%), living as long as possible (15.8%), avoiding NH care (3.1%) and contributing to society (0.8%) as most important. When asked what outcome concerned them most about the future, respondents reported: dementia (32.6%), dependence (30.4%), death (12.8%), stroke (12.5%), cancer (6.2%) requiring NH care (4.8%) and MI (0.7%). Maintaining independence was considered most important in younger and older cohorts. CONCLUSION: Cognitive and functional outcomes are important patient-relevant outcomes, sometimes more important than major vascular events. Incorporating these outcomes into trials may encourage patient participation and adherence to preventative regimens.

The effect of renal sympathetic denervation on nocturnal dipping in patients with resistant hypertension; observational data from a tertiary referral centre in the Republic of Ireland.

OBJECTIVE: Renal sympathetic denervation (RSD) is an emerging device based treatment for patients with resistant hypertension. Nocturnal dipping (ND) is defined as a decrease in BP of 10-20 % during sleep, and has been shown to be protective against cardiovascular disease. This study examined the effect of RSD on the 24 h BP profile of patients with resistant hypertension. METHODS AND RESULTS: The first 23 consecutive patients with resistant hypertension scheduled for renal denervation in a single centre were included. 24 h ambulatory blood pressure monitors (ABPM) were given to patients pre-procedure and 9 months post-procedure. RSD led to a statistically non-significant reduction in overall 24 h ABPM BP (150/85 ± 12/9 vs. 143/84 ± 15/11 mmHg; P > 0.05) despite a reduction in the number of antihypertensive medications (4.9 ± 1.2 vs. 4.3 ± 1.2; P = 0.001). There were improvements in systolic ND 1.7 ± 8 vs. 5.2 ± 8 %; P < 0.05), diastolic ND (5.2 ± 8 vs. 10.2 ± 9 %; P < 0.05) and mean arterial pressure (MAP) ND (4.2 ± 8 vs. 8.0 ± 8 %; P < 0.05). Non-significant changes in ND status were observed in systolic (17 vs. 43 % of participants; P > 0.05), diastolic (30 vs. 43 % of participants; P > 0.05) and MAP (22 vs. 39 % of participants; P > 0.05) measurements. CONCLUSIONS: These data suggest that RSD may lead to an improvement in nocturnal dipping in selected patients with resistant hypertension. This may have cardiovascular benefits even if reduction in BP is not achieved with RSD.

Overcoming the problem of residual microbial contamination in dental suction units left by conventional disinfection using novel single component suction handpieces in combination with automated flood disinfection.

OBJECTIVES: Decontaminating dental chair unit (DCU) suction systems in a convenient, safe and effective manner is problematic. This study aimed to identify and quantify the extent of the problems using 25 DCUs, methodically eliminate these problems and develop an efficient approach for reliable, effective, automated disinfection. METHODS: DCU suction system residual contamination by environmental and human-derived bacteria was evaluated by microbiological culture following standard aspiration disinfection with a quaternary ammonium disinfectant or alternatively, a novel flooding approach to disinfection. Disinfection of multicomponent suction handpieces, assembled and disassembled, was also studied. A prototype manual and a novel automated Suction Tube Cleaning System (STCS) were developed and tested, as were novel single component suction handpieces. RESULTS: Standard aspiration disinfection consistently failed to decontaminate DCU suction systems effectively. Semi-confluent bacterial growth (101-500 colony forming units (CFU) per culture plate) was recovered from up to 60% of suction filter housings and from up to 19% of high and 37% of low volume suction hoses. Manual and automated flood disinfection of DCU suction systems reduced this dramatically (ranges for filter cage and high and low volume hoses of 0-22, 0-16 and 0-14CFU/plate, respectively) (P<0.0001). Multicomponent suction handpieces could not be adequately disinfected without prior removal and disassembly. Novel single component handpieces, allowed their effective disinfection in situ using the STCS, which virtually eliminated contamination from the entire suction system. CONCLUSION: Flood disinfection of DCU suction systems and single component handpieces radically improves disinfection efficacy and considerably reduces potential cross-infection and cross-contamination risks. CLINICAL SIGNIFICANCE: DCU suction systems become heavily contaminated during use. Conventional disinfection does not adequately control this. Furthermore, multicomponent suction handpieces cannot be adequately disinfected without disassembly, which is costly in time, staff and resources. The automated STCS DCU suction disinfection system used with single component handpieces provides an effective solution.

Water chemistry in the microenvironment of rainbow trout Oncorhynchus mykiss embryos is affected by development, the egg capsule and crowding.

The hypothesis tested was that embryonic metabolism affects the water chemistry in the boundary layer. In addition, embryo crowding would further compound the metabolic effect on the water chemistry in the boundary layer. As development progressed, the magnitude of the boundary layer gradients for O(2) and pH, but not for NH4(+), increased. The presence of the egg capsule hindered the diffusion of O(2) into and H(+) and NH4(+) out of the embryo. The magnitude of the O(2), pH and NH4(+) boundary layer gradient was significantly increased when embryos were surrounded by either sham embryos or live embryos. The majority of this crowding effect on embryo boundary layers was due to changes in water flow rather than due to metabolism directly. These results clearly show that the microenvironment adjacent to the developing rainbow trout Oncorhynchus mykiss embryo becomes more stagnant as development progresses in the presence of the egg capsule and is further intensified with embryo crowding.

Salt intake and cardiovascular disease: why are the data inconsistent?

Effective population-based interventions are required to reduce the global burden of cardiovascular disease (CVD). Reducing salt intake has emerged as a leading target, with many guidelines recommending sodium intakes of 2.3 g/day or lower. These guideline thresholds are based largely on clinical trials reporting a reduction in blood pressure with low, compared with moderate, intake. However, no large-scale randomized trials have been conducted to determine the effect of low sodium intake on CV events. Prospective cohort studies evaluating the association between sodium intake and CV outcomes have been inconsistent and a number of recent studies have reported an association between low sodium intake (in the range recommended by current guidelines) and an increased risk of CV death. In the largest of these studies, a J-shaped association between sodium intake and CV death and heart failure was found. Despite a large body of research in this area, there are divergent interpretations of these data, with some advocating a re-evaluation of the current guideline recommendations. In this article, we explore potential reasons for the differing interpretations of existing evidence on the association between sodium intake and CVD. Similar to other areas in prevention, the controversy is likely to remain unresolved until large-scale definitive randomized controlled trials are conducted to determine the effect of low sodium intake (compared to moderate intake) on CVD incidence.

Control of bacterial contamination of washbasin taps and output water using Ecasol: a one-year study.

BACKGROUND: Contaminated washbasin taps and output water are an important source of bacteria that may cause nosocomial infection. A five-week pretreatment study of hot and cold water from 15 washbasin taps at Dublin Dental Hospital showed consistently heavy contamination by aerobic heterotrophic bacteria: mean bacterial counts of 482.5 [standard deviation (SD) 293] colony-forming units (cfu)/mL and 5022 (SD 4322) cfu/mL, respectively. AIM: To minimize microbial contamination of washbasin taps and output water in the long term using the electrochemically generated, pH-neutral disinfectant, Ecasol. METHODS: Initially, the 15,000-L water tank providing cold and hot water to washbasins, calorifiers and the distribution network were drained and sediment was removed. The system was shock-dosed with Ecasol 100 ppm to eradicate gross contamination and biofilms. Thereafter, tank water was automatically maintained at Ecasol 2.5 ppm prior to distribution. The microbiological quality of water from five sentinel washbasin taps was monitored weekly for 54 weeks using R2A agar. FINDINGS: The mean counts for hot, cold, mains and tank water during the 54-week study period were 1 (SD 4) cfu/mL, 2 (SD 4) cfu/mL, 205 (SD 160) cfu/mL and 0 cfu/mL, respectively. Swab samples of 33/40 taps, each tested on three separate occasions, yielded no growth on R2A agar, while five samples yielded <20 cfu/swab and two samples yielded >200 cfu/swab. No detrimental effects due to Ecasol were observed in the water network. CONCLUSION: Ecasol consistently minimized bacterial contamination of washbasin taps and output water in a dental hospital setting.

Randomized controlled trial of a new portable calf compression device (Venowave) for prevention of venous thrombosis in high-risk neurosurgical patients.

BACKGROUND: Patients undergoing neurosurgical procedures are at risk of venous thromboembolism (VTE), but often have contraindications for anticoagulant prophylaxis. OBJECTIVES: To assess the efficacy and tolerability of a new, lightweight, portable, battery-powered, intermittent calf compression device, Venowave, for the prevention of VTE in neurosurgical inpatients. PATIENTS/METHODS: We performed an open randomized controlled trial comparing Venowave with control for the prevention of VTE in patients undergoing neurosurgery. The primary outcome was the composite of asymptomatic deep vein thrombosis (DVT) detected by screening venography or compression ultrasound performed on day 9 (± 2 days) and symptomatic VTE. RESULTS: We randomized 75 patients to receive Venowave devices and 75 to the control group. All patients were prescribed graduated compression stockings and physiotherapy. VTE occurred in three patients randomized to Venowave and in 14 patients randomized to control (4.0% vs. 18.7%, relative risk 0.21; 95% confidence interval 0.05-0.75, P = 0.008). Similar reductions were seen for proximal DVT (2.7% vs. 8.0%) and symptomatic VTE (0% vs. 2.7%), and the results were consistent in all subgroups examined. CONCLUSIONS: Venowave devices are effective in preventing VTE in high-risk neurosurgical patients.

Disinfection procedures: their efficacy and effect on dimensional accuracy and surface quality of an irreversible hydrocolloid impression material.

OBJECTIVES: This study investigated the antibacterial efficacy and effect of 0.55% ortho-phthalaldehyde (Cidex OPA(®)) and 0.5% sodium hypochlorite (NaOCl) on the dimensional accuracy and surface quality of gypsum casts retrieved from an irreversible hydrocolloid impression material. METHODS: A simulated clinical cast and technique was developed to compare the dimensional accuracy and surface quality changes of the test gypsum casts with controls. Dimensional accuracy measurements were completed between fixed points using a travelling microscope under low angle illumination at a magnification of ×3. Surface quality changes of "smooth" and "rough" areas on the cast were evaluated by means of optical profilometry. The efficacy of the disinfection procedures against Pseudomonas aeruginosa was evaluated by determining the number of colony forming units (cfu) recovered after disinfection of alginate discs inoculated with 1×106cfu for defined intervals. RESULTS: The dimensional accuracy of the gypsum casts was not significantly affected by the disinfection protocols. Neither disinfectant solution nor immersion time had an effect on the surface roughness of the "smooth" area on the cast, however, a significant increase in surface roughness was observed with increasing immersion time for the "rough" surface. Complete elimination of viable Pseudomonas aeruginosa cells from alginate discs was obtained after 30 and 120 s immersion in Cidex OPA(®) and NaOCl, respectively. CONCLUSIONS: Immersion of irreversible hydrocolloid impressions in Cidex OPA(®) for 30 s was proved to be the most effective disinfection procedure.