Gridless adult cervical spine radiography and its' effect on image quality and radiation dose: A phantom study.

INTRODUCTION: Imaging of the cervical spine in general radiography is most frequently performed using an anti-scatter grid. The purpose of this study was to investigate the effects of a gridless setting on image quality and radiation dose during digital radiography of the anteroposterior (AP) and lateral (LAT) cervical spine. METHODS: A phantom study was performed with a variety of tube voltages (63-75 kV) with and without an anti-scatter grid. The tube current time product (mAs) and dose area product (DAP) were recorded and used to calculate effective dose (ED) and individual organ dose using PCXMC 2.0 software, as well as entrance surface dose (ESD) and objective image quality: signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Subjective visual image quality grading characteristics (VGC) was performed by five qualified radiographers. RESULTS: In a gridless setting, the AP and LAT positions showed significantly lower DAP (1.6 µGym2; 61.3 % and 1.6 µGym2; 51.2%), ESD (27.6 µGy; 57.3% and 77.2 µGy; 47.2%) and ED (4.2 µSv; 61.3% and 2.3 µSv; 48.9%). In a gridless setting in the AP position, there is a slight significant deterioration in image quality. In the lateral projection, on the other hand, the image quality without the use of grid was only significantly reduced in three of six criteria and there was no difference in the objective image quality between the two settings examined. CONCLUSION: The results of this study show that gridless setting significantly decreases radiation dose and image quality, but the quality in the lateral projection is still acceptable for diagnostic purpose. IMPLICATIONS FOR PRACTICE: The protocol without the use of the anti-scatter grid in cervical spine radiography leads to a reduction in the radiation dose in both projections, but the image quality in the AP is significantly reduced for all criteria examined, with a slight deterioration in image quality in the lateral projection.

Descriptive record of the activity of military critical care transfer teams deployed to London in April 2020 to undertake transfer of patients with COVID-19.

In the face of the COVID-19 outbreak, military healthcare teams were deployed to London to assist the London Ambulance Service t transfer ventilated patients between medical facilities. This paper describes the preparation and activity of these military teams, records the lessons identified (LI) and reviews the complications encountered'. The teams each had two members. A consultant or registrar in emergency medicine (EM) and pre-hospitalemergency medicine (PHEM)E or anaesthesia and an emergency nurse or paramedic. Following a period of training, the teams undertook 52 transfers over a 14-day period. LI centred around minimising both interruption to ventilation and risk of aerosolisation of infectious particles and thus the risk of transmission of COVID-19 to the treating clinicians. Three patient-related complications (6% of all transfers) were identified. This was the first occasion on which the Defence Medical Services (DMS) were the main focus of a large-scale clinical military aid to the civil authorities. It demonstrated that DMS personnel have the flexibility to deliver a novel effect and the ability to seamlessly and rapidly integrate with a civilian organisation. It highlighted some clinical lessons that may be useful for future prehospital emergency care taskings where patients may have a transmissible respiratory pathogen. It also showed that clinicians from different backgrounds are able to safely undertake secondary transfer of ventilated patients. This approacmay enhance flexibility in future operational patient care pathways.

Tick-borne Encephalitis Identified in Ireland: Diagnosis and Outcome.

Presentation Tick borne encephalitis (TBE) is not endemic in Ireland and diagnostic tests are seldom requested. We describe the first notified case in Ireland. A 50-year-old female returned from Lithuania and presented with fever and new neurologic signs. Diagnosis TBE was diagnosed by detection of TBE virus specific antibodies in serum and cerebrospinal fluid (CSF). Treatment The patient was managed with observation and supportive care consisting of intravenous fluids and analgesia. Discussion The case highlights the importance of awareness of TBE among physicians and travellers to guide appropriate testing and vaccination. TBE is being recognised in non-endemic countries posing an emerging risk to public health.

Blood Pressure, Orthostatic Hypotension and Falls in Patients with Advanced Cancer.

Aim Orthostatic Hypotension (OH) is an indicator of deteriorating autonomic dysfunction. Adherence to BP and OH measurement guidelines in an inpatient specialist palliative care unit (SPCU) was unknown. Compliance of BP and OH measurement in an advanced cancer cohort was audited. Methods A retrospective analysis of four consecutive months of patients admitted with an advanced cancer diagnosis to the inpatient SPCU was conducted. Data was obtained from 168 clinical records, and audited against current institutional clinical standards. Results Falls risk screening including BP and OH measurements were not measured on admission in 19% (n=32) cases as recommended by institutional guidelines. Where falls risks were identified in 94 (69%) patients only 71 (76%) of these had completed risk assessments. OH testing was incomplete or not conducted in 59% (n=42) of risk assessments. This had patient care and safety implications e.g. under-reporting falls risk. In addition, institutional guidelines were inflexible in clinical practice specific to a palliative care cohort of patient. Conclusions Institutional guidelines need regular reviewing. In cases where a healthcare professional determines it is inappropriate to perform an assessment, we recommend a modification to the tools allowing for recording of this decision. OH is an underestimated reality in hospice populations and the impact on hospice services is worthy of further study.

Satellite imaging reveals increased proportion of population exposed to floods.

Flooding affects more people than any other environmental hazard and hinders sustainable development1,2. Investing in flood adaptation strategies may reduce the loss of life and livelihood caused by floods3. Where and how floods occur and who is exposed are changing as a result of rapid urbanization4, flood mitigation infrastructure5 and increasing settlements in floodplains6. Previous estimates of the global flood-exposed population have been limited by a lack of observational data, relying instead on models, which have high uncertainty3,7-11. Here we use daily satellite imagery at 250-metre resolution to estimate flood extent and population exposure for 913 large flood events from 2000 to 2018. We determine a total inundation area of 2.23 million square kilometres, with 255-290 million people directly affected by floods. We estimate that the total population in locations with satellite-observed inundation grew by 58-86 million from 2000 to 2015. This represents an increase of 20 to 24 per cent in the proportion of the global population exposed to floods, ten times higher than previous estimates7. Climate change projections for 2030 indicate that the proportion of the population exposed to floods will increase further. The high spatial and temporal resolution of the satellite observations will improve our understanding of where floods are changing and how best to adapt. The global flood database generated from these observations will help to improve vulnerability assessments, the accuracy of global and local flood models, the efficacy of adaptation interventions and our understanding of the interactions between landcover change, climate and floods.

Milk of ruminants in ceramic baby bottles from prehistoric child graves.

The study of childhood diet, including breastfeeding and weaning, has important implications for our understanding of infant mortality and fertility in past societies1. Stable isotope analyses of nitrogen from bone collagen and dentine samples of infants have provided information on the timing of weaning2; however, little is known about which foods were consumed by infants in prehistory. The earliest known clay vessels that were possibly used for feeding infants appear in Neolithic Europe, and become more common throughout the Bronze and Iron Ages. However, these vessels-which include a spout through which liquid could be poured-have also been suggested to be feeding vessels for the sick or infirm3,4. Here we report evidence for the foods that were contained in such vessels, based on analyses of the lipid 'fingerprints' and the compound-specific δ13C and Δ13C values of the major fatty acids of residues from three small, spouted vessels that were found in Bronze and Iron Age graves of infants in Bavaria. The results suggest that the vessels were used to feed infants with milk products derived from ruminants. This evidence of the foodstuffs that were used to either feed or wean prehistoric infants confirms the importance of milk from domesticated animals for these early communities, and provides information on the infant-feeding behaviours that were practised by prehistoric human groups.

Recreational physical activity context and type preferences among male and female Emirati university students.

BACKGROUND: This study assessed recreational physical activity type and context preferences of Emirati university students. METHOD: This was a cross-sectional study in which a stratified random sample (n=628) (female 69.1%, male 30.9% mean age 20.79±3.81 y) completed an online survey. Relationships between gender and preferences were assessed using regression analysis, adjusted for body mass index and age. RESULTS: Activities with a fun element were the most preferred context (87.1%). Walking (66.7%) and swimming (61.7%) were the most preferred activity types. Males had significantly higher odds of preferring competitive activities, and activity types such as football, fitness/weights and jogging. Females had significantly higher odds of preferring activities with people of the same gender, with supervision and done at home, and activity types such as walking, aerobics, cycling, squash and yoga. CONCLUSION: These results can inform physical activity planning for university students in the United Arab Emirates. Fun activity opportunities involving walking or swimming and in the local neighbourhood may be popular for both males and females. Future research could explore uptake and maintenance of activity options, based on preferred activity attributes.

Knowledge of physical activity guidelines and mental health benefits among Emirati university students.

AIMS: The purpose of this study was to assess Emirati university students' knowledge of physical activity guidelines and perceptions of the benefits of physical activity for mental health. METHODS: A random sample (n = 628) completed an online questionnaire assessing the recommended amount of physical activity for good health (min/week) and to what extent exercise can help improve wellbeing, and manage depression and anxiety/stress (5-point Likert-type scale). RESULTS: Only 3% of respondents identified 150 min/week and less than half (39%) of the respondents reported an amount within the range of 150-300 min/week. Most respondents believed that physical activity could improve wellbeing (69%), and manage depression (71%) and anxiety/stress (74%). Females were more likely than males to view physical activity as a way to manage depression (p = .003), and anxiety/stress (p = .002). CONCLUSIONS: More work may be required to promote awareness of physical activity guidelines in this population, and males' awareness of mental health benefits of physical activity.

Selective PEGylation of Parylene-C/SiO2 Substrates for Improved Astrocyte Cell Patterning.

Controlling the spatial distribution of glia and neurons in in vitro culture offers the opportunity to study how cellular interactions contribute to large scale network behaviour. A recently developed approach to cell-patterning uses differential adsorption of animal-serum protein on parylene-C and SiO2 surfaces to enable patterning of neurons and glia. Serum, however, is typically poorly defined and generates reproducibility challenges. Alternative activation methods are highly desirable to enable patterning without relying on animal serum. We take advantage of the innate contrasting surface chemistries of parylene-C and SiO2 to enable selective bonding of polyethylene glycol SiO2 surfaces, i.e. PEGylation, rendering them almost completely repulsive to cell adhesion. As the reagents used in the PEGylation protocol are chemically defined, the reproducibility and batch-to-batch variability complications associated with the used of animal serum are avoided. We report that PEGylated parylene-C/SiO2 substrates achieve a contrast in astrocyte density of 65:1 whereas the standard serum-immersion protocol results in a contrast of 5.6:1. Furthermore, single-cell isolation was significantly improved on PEGylated substrates when astrocytes were grown on close-proximity parylene-C nodes, whereas isolation was limited on serum-activated substrates due tolerance for cell adhesion on serum-adsorbed SiO2 surfaces.

Patterning of functional human astrocytes onto parylene-C/SiO2 substrates for the study of Ca2+ dynamics in astrocytic networks.

OBJECTIVE: Recent literature suggests that astrocytes form organized functional networks and communicate through transient changes in cytosolic Ca2+. Traditional techniques to investigate network activity, such as pharmacological blocking or genetic knockout, are difficult to restrict to individual cells. The objective of this work is to develop cell-patterning techniques to physically manipulate astrocytic interactions to enable the study of Ca2+ in astrocytic networks. APPROACH: We investigate how an in vitro cell-patterning platform that utilizes geometric patterns of parylene-C on SiO2 can be used to physically isolate single astrocytes and small astrocytic networks. MAIN RESULTS: We report that single astrocytes are effectively isolated on 75 × 75 µm square parylene nodes, whereas multi-cellular astrocytic networks are isolated on larger nodes, with the mean number of astrocytes per cluster increasing as a function of node size. Additionally, we report that astrocytes in small multi-cellular clusters exhibit spatio-temporal clustering of Ca2+ transients. Finally, we report that the frequency and regularity of Ca2+ transients was positively correlated with astrocyte connectivity. SIGNIFICANCE: The significance of this work is to demonstrate how patterning hNT astrocytes replicates spatio-temporal clustering of Ca2+ signalling that is observed in vivo but not in dissociated in vitro cultures. We therefore highlight the importance of the structure of astrocytic networks in determining ensemble Ca2+ behaviour.

Potential urban runoff impacts and contaminant distributions in shoreline and reservoir environments of Lake Havasu, southwestern United States.

Heavy metal, nutrient, and hydrocarbon levels in and adjacent to Lake Havasu, a regionally significant water supply reservoir with a highly controlled, dynamic flow regime, are assessed in relation to possible stormwater runoff impacts from an arid urban center. Shallow groundwater and sediment analyses from ephemeral drainage (wash) mouths that convey stormwater runoff from Lake Havasu City, Arizona to the reservoir, provided contaminant control points and correlation ties with the reservoir environment. Fine-grain sediments tend to contain higher heavy metal concentrations whereas nutrients are more evenly distributed, except low total organic carbon levels from young wash mouth surfaces devoid of vegetation. Heavy metal and total phosphate sediment concentrations in transects from wash mouths into the reservoir have mixed and decreasing trends, respectively. Both series may indicate chemical depositional influences from urban runoff, yet no statistically significant concentration differences occur between specific wash mouths and corresponding offshore transects. Heavy metal pollution indices of all sediments indicate no discernible to minor contamination, indicating that runoff impacts are minimal. Nevertheless, several heavy metal concentrations from mid-reservoir sediment sites increase southward through the length of the reservoir. Continual significant water flow through the reservoir may help to disperse locally derived runoff particulates, which could mix and settle down gradient with chemical loads from upriver sources and local atmospheric deposition. Incorporating the shoreline environment with the reservoir investigation provides spatial continuity in assessing contaminant sources and distribution patterns. This is particularly acute in the investigation of energetic, flow-through reservoirs in which sources may be overlooked if solely analyzing the reservoir environment.

Effects of communication burstiness on consensus formation and tipping points in social dynamics.

Current models for opinion dynamics typically utilize a Poisson process for speaker selection, making the waiting time between events exponentially distributed. Human interaction tends to be bursty though, having higher probabilities of either extremely short waiting times or long periods of silence. To quantify the burstiness effects on the dynamics of social models, we place in competition two groups exhibiting different speakers' waiting-time distributions. These competitions are implemented in the binary naming game and show that the relevant aspect of the waiting-time distribution is the density of the head rather than that of the tail. We show that even with identical mean waiting times, a group with a higher density of short waiting times is favored in competition over the other group. This effect remains in the presence of nodes holding a single opinion that never changes, as the fraction of such committed individuals necessary for achieving consensus decreases dramatically when they have a higher head density than the holders of the competing opinion. Finally, to quantify differences in burstiness, we introduce the expected number of small-time activations and use it to characterize the early-time regime of the system.

Epidemiological typing of Neisseria gonorrhoeae and detection of markers associated with antimicrobial resistance directly from urine samples using next generation sequencing.

OBJECTIVES: To investigate the potential for next generation sequencing (NGS) to be used directly on clinical specimens that have tested positive for Neisseria gonorrhoeae by nucleic acid amplification testing (NAAT), to generate information on epidemiological genotyping and antimicrobial resistance (AMR) markers. METHODS: DNA was extracted from 13 N. gonorrhoeae NAAT-positive urine specimens, enriched for microbial DNA and sequenced using the Ion Torrent PGM workflow. Sequences that aligned to the human genome were filtered out and the remaining sequences were de novo assembled. The resulting contigs were searched for regions of interest using Ridom SeqSphere. MLST and NG-MAST alleles were assigned according to the schemes at PubMLST.org and NG-MAST.net, respectively. RESULTS: In total, 11 of the 13 samples tested generated a sufficient number of N. gonorrhoeae sequence reads to provide full coverage of the genome at a depth of 6-130×. Complete MLST and NG-MAST sequence types could be generated for each of these samples. The presence of 10 different AMR markers was investigated, and both previously reported and novel mutations were identified in genes associated with reduced susceptibility to several antimicrobials. CONCLUSIONS: We found that sequencing the entire genome of N. gonorrhoeae directly from clinical samples is possible using NGS, and that multiple levels of N. gonorrhoeae typing information can be generated. As NAAT only testing becomes more common, this method could be used to detect both known and novel mutations associated with AMR and to generate genotyping information, supporting AMR and epidemiological surveillance in the absence of culturing.

Targeted de-escalation rounds may effectively and safely reduce meropenem use.

OBJECTIVE: Use of meropenem in our hospital has doubled in recent years. An audit in 2013 showed that although initiation of therapy with meropenem was generally appropriate, therapy was rarely subsequently reviewed and de-escalated where appropriate. Therefore, a structured stewardship initiative focussed on meropenem de-escalation was developed. METHODS: A local guideline for review and de-escalation of meropenem was developed and approved by the Antimicrobial Stewardship Team. The guideline outlined clinical and microbiological criteria which when met should lead to recommendation for meropenem de-escalation. Implementation of the guideline was piloted for a period of 4 weeks by a consultant microbiologist and an antimicrobial pharmacist. Days of meropenem use and crude mortality in those in whom de-escalation was implemented were compared with those where de-escalation was not recommended or was recommended but not implemented. RESULTS: Thirty-three patients were reviewed. Overall, a recommendation to de-escalate from meropenem to a specified alternative antibiotic was made for 18 (55 %) patients. This advice was followed for 12 (36 %) patients. The median days of meropenem use in patients where meropenem was de-escalated was 4.5 days (range 2-19) compared with 14 days (range 6-84) where de-escalation was not recommended or the recommendation was not implemented. There was no statistically significant difference in crude mortality between patients de-escalated from meropenem and those where meropenem was continued. CONCLUSION: This pilot study suggests that targeted carbapenem de-escalation stewardship activity based on pre-determined criteria, while labour intensive, can effectively and safely reduce meropenem use in the acute hospital setting.

Polyol production during heterofermentative growth of the plant isolate Lactobacillus florum 2F.

AIMS: This study examined the fermentative growth and polyol production of Lactobacillus florum and other plant-associated lactic acid bacteria (LAB). METHODS AND RESULTS: Sugar consumption and end-product production were measured for Lact. florum 2F in the presence of fructose, glucose and both sugars combined. The genome of Lact. florum was examined for genes required for mannitol and erythritol biosynthesis. The capacity for other plant-associated LAB to synthesize polyols was also assessed. CONCLUSIONS: Lactobacillus florum exhibited higher growth rates and cell yields in the presence of both fructose and glucose. Lactobacillus florum 2F produced lactate, acetate and ethanol as well as erythritol and mannitol. Lactobacillus florum 2F synthesized mannitol during growth on fructose and erythritol during growth on glucose. Gene and protein homology searches identified a mannitol dehydrogenase in the Lact. florum 2F genome but not the genes responsible for erythritol biosynthesis. Lastly, we found that numerous other heterofermentative LAB species synthesize erythritol and/or mannitol. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus florum is a recently identified, plant-associated, fructophilic LAB species. Our results show that Lact. florum growth rates and heterofermentation end-products differ depending on the sugar substrates present and growth yields can be improved when combinations of sugars are provided. Lactobacillus florum 2F produces erythritol and mannitol, two polyols that are relevant to foods and potentially also in plant environments. The capacity for polyol biosynthesis appears to be common among plant-associated, LAB species.

Non-invasive ventilation: evaluation of CO2 washout by intentional leaking in three recent oronasal masks. A pilot study.

BACKGROUND: Many types of interfaces with intentional leaks exist for Non Invasive Ventilation. The purpose of intentional leaks is to remove CO2 from the interface, however the calibration does not allow a sufficiently large flow and rebreathing of CO2 can occur. The aim of this study was to compare the CO2 rinsing capacities of three new generation oronasal masks with intentional leaks (A: Quattro®, [Resmed]; B: Amara® [Respironics]; C: Forma® [Fisher&Paykel]) in healthy subjects. METHODS: Seventeen healthy volunteers were included in this prospective cross-sectional, randomized, double-blinded trial. Each subject underwent ventilation with a home ventilator (IPAP: 14 cmH2O; EPAP: 4 cmH2O) with each mask consecutively. Transcutaneous capnography (PtcCO2) recordings were carried out throughout the trial and ventilator data (tidal volume, respiratory rate, minute ventilation and unintentional leaks) were also analyzed. Mask comfort was assessed using a visual analog scale (0 to 10). RESULTS: The results showed no differences in PtcCO2 between masks (P=0.82). There were no significant differences in respiratory parameters (tidal volume, P=0.79; respiratory rate, P=0.65; minute ventilation, P=0.12) between masks. The rate of unintentional leaks were significantly lower for Mask A (P=0.016). Subjects rated Mask A and Mask C as more comfortable than Mask B (P=0.041). CONCLUSION: There was no effect of mask on PtcCO2 in healthy subjects. The mask with the highest comfort rating had not the lowest rate of unintentional leaks.

Azithromycin suppresses P. gingivalis LPS-induced pro-inflammatory cytokine and chemokine production by human gingival fibroblasts in vitro.

OBJECTIVE: Azithromycin is a macrolide antibiotic that appears to have both antibacterial and anti-inflammatory properties. This study aimed to investigate the effect of azithromycin on the production of pro-inflammatory cytokines and chemokines by human gingival fibroblasts (HGF) in vitro. MATERIALS AND METHODS: The effects of azithromycin (0.1 to 10 µg/mL) on the production of interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), and growth-regulated oncogene (GRO) by human gingival fibroblasts cultured in the presence or absence of Porphyromonas gingivalis lipopolysaccharide (LPS) was studied. Cytokine and chemokine protein levels in the culture supernatant were assessed using a Luminex® multiplex immunoassay. RESULTS: P. gingivalis LPS induced cytokine/chemokine (IL-6, IL-8, MCP-1, and GRO) protein production in HGFs, and this effect was suppressed by azithromycin at all concentrations tested. CONCLUSIONS: This study demonstrates that azithromycin suppresses P. gingivalis LPS-induced cytokine/chemokine protein production in HGF, which may explain some of the clinical benefits observed with the adjunctive use of azithromycin in the treatment of periodontitis. CLINICAL RELEVANCE: The current study examines the anti-inflammatory properties of azithromycin which may make it useful as an adjunct treatment to periodontitis. Specifically, we used azithromycin to modulate the production of pro-inflammatory cytokines by gingival fibroblasts known to be important in periodontal inflammation.

Real-time investigation of a Legionella pneumophila outbreak using whole genome sequencing.

Legionella pneumophila is the main pathogen responsible for outbreaks of Legionnaires' disease, which can be related to contaminated water supplies such as cooling towers or water pipes. We combined conventional molecular methods and whole genome sequence (WGS) analysis to investigate an outbreak of L. pneumophila in a large Australian hospital. Typing of these isolates using sequence-based typing and virulence gene profiling, was unable to discriminate between outbreak and non-outbreak isolates. WGS analysis was performed on isolates during the outbreak, as well as on unlinked isolates from the Public Health Microbiology reference collection. The more powerful resolution provided by analysis of whole genome sequences allowed outbreak isolates to be distinguished from isolates that were temporally and spatially unassociated with the outbreak, demonstrating that this technology can be used in real-time to investigate L. pneumophila outbreaks.