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1.
Fungal Genet Biol ; 170: 103858, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38101696

ABSTRACT

The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered in 1998 as the cause of chytridiomycosis, an emerging infectious disease causing mass declines in amphibian populations worldwide. The rapid population declines of the 1970s-1990s were likely caused by the spread of a highly virulent lineage belonging to the Bd-GPL clade that was introduced to naïve susceptible populations. Multiple genetically distinct and regional lineages of Bd have since been isolated and sequenced, greatly expanding the known biological diversity within this fungal pathogen. To date, most Bd research has been restricted to the limited number of samples that could be isolated using culturing techniques, potentially causing a selection bias for strains that can grow on media and missing other unculturable or fastidious strains that are also present on amphibians. We thus attempted to characterize potentially non-culturable genetic lineages of Bd from distinct amphibian taxa using sequence capture technology on DNA extracted from host tissue and swabs. We focused our efforts on host taxa from two different regions that likely harbored distinct Bd clades: (1) wild-caught leopard frogs (Rana) from North America, and (2) a Japanese Giant Salamander (Andrias japonicus) at the Smithsonian Institution's National Zoological Park that exhibited signs of disease and tested positive for Bd using qPCR, but multiple attempts failed to isolate and culture the strain for physiological and genetic characterization. We successfully enriched for and sequenced thousands of fungal genes from both host clades, and Bd load was positively associated with number of recovered Bd sequences. Phylogenetic reconstruction placed all the Rana-derived strains in the Bd-GPL clade. In contrast, the A. japonicus strain fell within the Bd-Asia3 clade, expanding the range of this clade and generating additional genomic data to confirm its placement. The retrieved ITS locus matched public barcoding data from wild A. japonicus and Bd infections found on other amphibians in India and China, suggesting that this uncultured clade is widespread across Asia. Our study underscores the importance of recognizing and characterizing the hidden diversity of fastidious strains in order to reconstruct the spatiotemporal and evolutionary history of Bd. The success of the sequence capture approach highlights the utility of directly sequencing pathogen DNA from host tissue to characterize cryptic diversity that is missed by culture-reliant approaches.


Subject(s)
Chytridiomycota , Animals , Phylogeny , Chytridiomycota/genetics , Amphibians/genetics , Amphibians/microbiology , Biological Evolution , DNA
2.
J Intensive Care Soc ; 24(4): 427-434, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37841304

ABSTRACT

Aim: To describe the protocol for a multi-centre randomised controlled trial to determine whether treatment protocols monitoring daily CRP (C-reactive protein) or PCT (procalcitonin) safely allow a reduction in duration of antibiotic therapy in hospitalised adult patients with sepsis. Design: Multicentre three-arm randomised controlled trial. Setting: UK NHS hospitals. Target population: Hospitalised critically ill adults who have been commenced on intravenous antibiotics for sepsis. Health technology: Three protocols for guiding antibiotic discontinuation will be compared: (a) standard care; (b) standard care + daily CRP monitoring; (c) standard care + daily PCT monitoring. Standard care will be based on routine sepsis management and antibiotic stewardship. Measurement of outcomes and costs. Outcomes will be assessed to 28 days. The primary outcomes are total duration of antibiotics and safety outcome of all-cause mortality. Secondary outcomes include: escalation of care/re-admission; infection re-lapse/recurrence; antibiotic dose; length and level of critical care stay and length of hospital stay. Ninety-day all-cause mortality rates will also be collected. An assessment of cost effectiveness will be performed. Conclusion: In the setting of routine NHS care, if this trial finds that a treatment protocol based on monitoring CRP or PCT safely allows a reduction in duration of antibiotic therapy, and is cost effective, then this has the potential to change clinical practice for critically ill patients with sepsis. Moreover, if a biomarker-guided protocol is not found to be effective, then it will be important to avoid its use in sepsis and prevent ineffective technology becoming widely adopted in clinical practice.

3.
J Intensive Care Soc ; 23(1): 53-57, 2022 Feb.
Article in English | MEDLINE | ID: mdl-37593536

ABSTRACT

In 2013, a group of clinicians on behalf of the National Institute for Health Research, collaborated with ICU Steps to produce guidance about people being enrolled in more than one critical care trial. This is referred to as "co-enrolment" and can be where a person takes part in one study at the same time as another study (or one after the other in a short time-frame). For instance, being part of a study looking at sepsis drugs and a mechanical ventilation weaning study. The drivers for developing this guidance were a lack of any existing guidance, nationally and internationally, at that time, and a desire to ensure high quality research is conducted. The emphasis was on making trials as safe as possible for patients and ensuring robust trial outcomes. Critical care was seen to lead in this, with our exemplar guidance used across all health research. We wish to revisit this guidance now that there is more experience of coenrolment in critical care trials. There is also more awareness of different consent models, such as deferred consent (taking consent when a person is awake and able to give consent) and consultee consent (asking families or independent professionals to consent). Consenting to coenrolment is an important ethical consideration for the revision of this guidance.

4.
Eur Geriatr Med ; 12(6): 1257-1265, 2021 12.
Article in English | MEDLINE | ID: mdl-34156656

ABSTRACT

PURPOSE: To investigate performance of the Months of the Year Backwards (MOTYB) test in older hospitalised patients with delirium, dementia, and no cognitive impairment. METHODS: Secondary analysis of data from a case-control study of 149 hospitalised patients aged ≥ 65 years with delirium [with or without dementia (N = 50)], dementia [without delirium (N = 46)], and no cognitive impairment (N = 53). Verbatim transcripts of MOTYB audio recordings were analysed to determine group differences in response patterns. RESULTS: In the total sample [median age 85y (IQR 80-88), 82% female], patients with delirium were more often unable to recite months backward to November (36/50 = 72%) than patients with dementia (21/46 = 46%; p < 0.01) and both differed significantly from patients without cognitive impairment (2/53 = 4%; p's < 0.001). 121/149 (81%) of patients were able to engage with the test. Patients with delirium were more often unable to engage with MOTYB (23/50 = 46%; e.g., due to reduced arousal) than patients with dementia (5/46 = 11%; p < 0.001); both groups differed significantly (p's < 0.001) from patients without cognitive impairment (0/53 = 0%). There was no statistically significant difference between patients with delirium (2/27 = 7%) and patients with dementia (8/41 = 20%) in completing MOTYB to January, but performance in both groups differed (p < 0.001 and p < 0.02, respectively) from patients without cognitive impairment (35/53 = 66%). CONCLUSION: Delirium was associated with inability to engage with MOTYB and low rates of completion. In patients able to engage with the test, error-free completion rates were low in delirium and dementia. Recording of engagement and patterns of errors may add useful information to MOTYB scoring.


Subject(s)
Cognitive Dysfunction , Delirium , Dementia , Aged , Aged, 80 and over , Arousal , Case-Control Studies , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/epidemiology , Delirium/diagnosis , Delirium/epidemiology , Dementia/diagnosis , Dementia/epidemiology , Dementia/psychology , Female , Humans , Male
6.
AIDS Behav ; 24(12): 3385-3394, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32394233

ABSTRACT

Interventions that utilize the influence of peer change agents (PCAs) have been shown to be effective strategies for engaging key populations in HIV prevention. To date, little is known about the characteristics of PCAs associated with their effectiveness. Drawing on data from a peer leader PrEP intervention for young Black men who have sex with men (YBMSM) (N = 423), we evaluated the effects of experiential (i.e., living with HIV, PrEP awareness, PrEP use), psychographic (i.e., self-perceived leadership, innovativeness), and network (i.e., degree centrality, eigenvector centrality, and brokerage) characteristics on three effectiveness outcomes: (1) recruiting peers into the study; (2) completing "booster" sessions; and (3) linking peers to PrEP care. For each outcome, multivariable regressions were performed. On average, PCAs recruited 0.89 peers, completed 1.99 boosters, and had 1.33 network peers linked to PrEP care. Experiential factors: Prior PrEP awareness was positively associated with booster completion. Network factors: Being a network broker (i.e., connecting otherwise disconnected communities) was positively associated with peer recruitment but negatively associated with linking peers to PrEP, and degree centrality (i.e., the number of network connections someone has) and eigenvector centrality (i.e., being connected to well-connected network associates) were positively associated with linking peers to PrEP. Psychographic characteristics were not associated with any outcome. These findings can be used to inform PCA selection and to identify subpopulations who require additional support to excel as PCAs.


Subject(s)
HIV Infections , Social Networking , Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV Infections/prevention & control , Homosexuality, Male , Humans , Male , Pre-Exposure Prophylaxis , Sexual and Gender Minorities
7.
PLoS One ; 15(1): e0227471, 2020.
Article in English | MEDLINE | ID: mdl-31978127

ABSTRACT

BACKGROUND: Delirium is a common and serious acute neuropsychiatric syndrome which is often missed in routine clinical care. Inattention is the core cognitive feature. Diagnostic test accuracy (including cut-points) of a smartphone Delirium App (DelApp) for assessing attention deficits was assessed in older hospital inpatients. METHODS: This was a case-control study of hospitalised patients aged ≥65 years with delirium (with or without pre-existing cognitive impairment), who were compared to patients with dementia without delirium, and patients without cognitive impairment. Reference standard delirium assessment, which included a neuropsychological test battery, was based on Diagnostic and Statistical Manual of Mental Disorders-5 criteria. A separate blinded assessor administered the DelApp arousal assessment (score 0-4) and attention task (0-6) yielding an overall score of 0 to 10 (lower scores indicate poorer performance). Analyses included receiver operating characteristic curves and sensitivity and specificity. Optimal cut-points for delirium detection were determined using Youden's index. RESULTS: A total of 187 patients were recruited, mean age 83.8 (range 67-98) years, 152 (81%) women; n = 61 with delirium; n = 61 with dementia without delirium; and n = 65 without cognitive impairment. Patients with delirium performed poorly on the DelApp (median score = 4/10; inter-quartile range 3.0, 5.5) compared to patients with dementia (9.0; 5.5, 10.0) and those without cognitive impairment (10.0; 10.0, 10.0). Area under the curve for detecting delirium was 0.89 (95% Confidence Interval 0.84, 0.94). At an optimal cut-point of ≤8, sensitivity was 91.7% (84.7%, 98.7%) and specificity 74.2% (66.5%, 81.9%) for discriminating delirium from the other groups. Specificity was 68.3% (56.6%, 80.1%) for discriminating delirium from dementia (cut-point ≤6). CONCLUSION: Patients with delirium (with or without pre-existing cognitive impairment) perform poorly on the DelApp compared to patients with dementia and those without cognitive impairment. A cut-point of ≤8/10 is suggested as having optimal sensitivity and specificity. The DelApp is a promising tool for assessment of attention deficits associated with delirium in older hospitalised adults, many of whom have prior cognitive impairment, and should be further validated in representative patient cohorts.


Subject(s)
Delirium/diagnosis , Mobile Applications , Neuropsychological Tests , Aged , Aged, 80 and over , Area Under Curve , Case-Control Studies , Cognitive Dysfunction/complications , Cognitive Dysfunction/pathology , Delirium/complications , Dementia/complications , Dementia/pathology , Female , Hospitalization , Humans , Male , ROC Curve , Sensitivity and Specificity , Severity of Illness Index , Smartphone
8.
BMJ Open ; 9(12): e030815, 2019 12 22.
Article in English | MEDLINE | ID: mdl-31871255

ABSTRACT

Conducting clinical trials in critical care is integral to improving patient care. Unique practical and ethical considerations exist in this patient population that make patient recruitment challenging, including narrow recruitment timeframes and obtaining patient consent often in time-critical situations. Units currently vary significantly in their ability to recruit according to infrastructure and level of research activity. AIM: To identify variability in the research infrastructure of UK intensive care units and their ability to conduct research and recruit patients into clinical trials. DESIGN: We evaluated factors related to intensive care patient enrolment into clinical trials in the UK. This consisted of a qualitative synthesis carried out with two datasets of in-depth interviews (distinct participants across the two datasets) conducted with 27 intensive care consultants (n=9), research nurses (n=17) and trial coordinators (n=1) from 27 units across the UK. Primary and secondary analyses of two datasets (one dataset had been analysed previously) were undertaken in the thematic analysis. FINDINGS: The synthesis yielded an overarching core theme of normalising research, characterised by motivations for promoting research and fostering research-active cultures within resource constraints, with six themes under this to explain the factors influencing critical care research capacity: organisational, human, study, practical resources, clinician and patient/family factors. There was a strong sense of integrating research in routine clinical practice, and recommendations are outlined. CONCLUSIONS: The central and transferable tenet of normalising research advocates the importance of developing a culture where research is inclusive alongside clinical practice in routine patient care and is a requisite for all healthcare individuals from organisational to direct patient contact level.


Subject(s)
Clinical Trials as Topic/organization & administration , Critical Care/standards , Intensive Care Units , Patient Selection , Humans , Qualitative Research , United Kingdom
9.
BMJ Open ; 9(11): e031630, 2019 11 10.
Article in English | MEDLINE | ID: mdl-31712342

ABSTRACT

INTRODUCTION: Weaning from ventilation is a complex process involving several stages that include recognition of patient readiness to begin the weaning process, steps to reduce ventilation while optimising sedation in order not to induce distress and removing the endotracheal tube. Delay at any stage can prolong the duration of mechanical ventilation. We developed a multicomponent intervention targeted at helping clinicians to safely expedite this process and minimise the harms associated with unnecessary mechanical ventilation. METHODS AND ANALYSIS: This is a 20-month cluster randomised stepped wedge clinical and cost-effectiveness trial with an internal pilot and a process evaluation. It is being conducted in 18 paediatric intensive care units in the UK to evaluate a protocol-based intervention for reducing the duration of invasive mechanical ventilation. Following an initial 8-week baseline data collection period in all sites, one site will be randomly chosen to transition to the intervention every 4 weeks and will start an 8-week training period after which it will continue the intervention for the remaining duration of the study. We aim to recruit approximately 10 000 patients. The primary analysis will compare data from before the training (control) with that from after the training (intervention) in each site. Full details of the analyses will be in the statistical analysis plan. ETHICS AND DISSEMINATION: This protocol was reviewed and approved by NRES Committee East Midlands-Nottingham 1 Research Ethics Committee (reference: 17/EM/0301). All sites started patient recruitment on 5 February 2018 before randomisation in April 2018. Results will be disseminated in 2020. The results will be presented at national and international conferences and published in peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: ISRCTN16998143.


Subject(s)
Deep Sedation , Randomized Controlled Trials as Topic/methods , Ventilator Weaning , Child , Cost-Benefit Analysis , Humans , Multicenter Studies as Topic , Respiration, Artificial/statistics & numerical data , Ventilator Weaning/methods
10.
Viruses ; 11(10)2019 09 27.
Article in English | MEDLINE | ID: mdl-31569752

ABSTRACT

Influenza viruses are important pathogens causing respiratory disease in humans and animals. In contrast to influenza A virus (IAV) that can infect a wide range of animal species, other influenza viruses, including influenza B virus (IBV), influenza C virus (ICV), and influenza D virus (IDV) have a limited host range. Swine can be infected with all four different genera of influenza viruses. IAV infection of pigs causes the well-known swine influenza that poses significant threats to human and animal health. However, influenza virus infection of pigs with IBV, ICV, and IDV are not well-characterized. Herein, we compared pathogenicity of IBV and IDV using intratracheal and intranasal infection of pigs, which are IAV seropositive, and commingled naïve pigs with the infected animals to determine their transmissibility. Both viruses caused fever and some lung lesions, replicated in the lungs of infected pigs, but only IDV transmitted to the contact animals. Although IBV and IDV displayed differing levels of replication in the respiratory tract of infected pigs, no significant differences in pathogenicity of both viruses were observed. These results indicate that both IBV and IDV can replicate, and are pathogenic in pigs.


Subject(s)
Influenza B virus/physiology , Orthomyxoviridae Infections/transmission , Orthomyxoviridae Infections/virology , Swine Diseases/transmission , Swine Diseases/virology , Thogotovirus/physiology , Animals , Disease Models, Animal , Host Specificity , Influenza A virus , Influenza B virus/pathogenicity , Gammainfluenzavirus , Lung/pathology , Lung/virology , Orthomyxoviridae Infections/pathology , Swine , Swine Diseases/pathology , Thogotovirus/pathogenicity , United States , Viral Load , Virulence , Virus Replication
11.
Health Technol Assess ; 23(48): 1-114, 2019 09.
Article in English | MEDLINE | ID: mdl-31532358

ABSTRACT

BACKGROUND: Invasive mechanical ventilation (IMV) is a life-saving intervention. Following resolution of the condition that necessitated IMV, a spontaneous breathing trial (SBT) is used to determine patient readiness for IMV discontinuation. In patients who fail one or more SBTs, there is uncertainty as to the optimum management strategy. OBJECTIVE: To evaluate the clinical effectiveness and cost-effectiveness of using non-invasive ventilation (NIV) as an intermediate step in the protocolised weaning of patients from IMV. DESIGN: Pragmatic, open-label, parallel-group randomised controlled trial, with cost-effectiveness analysis. SETTING: A total of 51 critical care units across the UK. PARTICIPANTS: Adult intensive care patients who had received IMV for at least 48 hours, who were categorised as ready to wean from ventilation, and who failed a SBT. INTERVENTIONS: Control group (invasive weaning): patients continued to receive IMV with daily SBTs. A weaning protocol was used to wean pressure support based on the patient's condition. Intervention group (non-invasive weaning): patients were extubated to NIV. A weaning protocol was used to wean inspiratory positive airway pressure, based on the patient's condition. MAIN OUTCOME MEASURES: The primary outcome measure was time to liberation from ventilation. Secondary outcome measures included mortality, duration of IMV, proportion of patients receiving antibiotics for a presumed respiratory infection and health-related quality of life. RESULTS: A total of 364 patients (invasive weaning, n = 182; non-invasive weaning, n = 182) were randomised. Groups were well matched at baseline. There was no difference between the invasive weaning and non-invasive weaning groups in median time to liberation from ventilation {invasive weaning 108 hours [interquartile range (IQR) 57-351 hours] vs. non-invasive weaning 104.3 hours [IQR 34.5-297 hours]; hazard ratio 1.1, 95% confidence interval [CI] 0.89 to 1.39; p = 0.352}. There was also no difference in mortality between groups at any time point. Patients in the non-invasive weaning group had fewer IMV days [invasive weaning 4 days (IQR 2-11 days) vs. non-invasive weaning 1 day (IQR 0-7 days); adjusted mean difference -3.1 days, 95% CI -5.75 to -0.51 days]. In addition, fewer non-invasive weaning patients required antibiotics for a respiratory infection [odds ratio (OR) 0.60, 95% CI 0.41 to 1.00; p = 0.048]. A higher proportion of non-invasive weaning patients required reintubation than those in the invasive weaning group (OR 2.00, 95% CI 1.27 to 3.24). The within-trial economic evaluation showed that NIV was associated with a lower net cost and a higher net effect, and was dominant in health economic terms. The probability that NIV was cost-effective was estimated at 0.58 at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year. CONCLUSIONS: A protocolised non-invasive weaning strategy did not reduce time to liberation from ventilation. However, patients who underwent non-invasive weaning had fewer days requiring IMV and required fewer antibiotics for respiratory infections. FUTURE WORK: In patients who fail a SBT, which factors predict an adverse outcome (reintubation, tracheostomy, death) if extubated and weaned using NIV? TRIAL REGISTRATION: Current Controlled Trials ISRCTN15635197. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 48. See the NIHR Journals Library website for further project information.


Patients who become very unwell may require help from a breathing machine. This requires the patient to be given drugs to put them to sleep (sedation) and have a tube placed through their mouth directly into the windpipe (tube ventilation). This can be life-saving, but may cause harm if used for long periods of time. Non-invasive ventilation (mask ventilation) provides breathing support through a mask that covers the face. Mask ventilation has several advantages over tube ventilation, such as less need for sedation, and it enables the patient to cough and communicate. In previous studies, switching patients from tube to mask ventilation when they start to get better seemed to improve survival rates and reduce complications. The Breathe trial tested if using a protocol to remove tube ventilation and replace it with mask ventilation is better than continuing with tube ventilation until the patient no longer needs breathing machine support. The trial recruited 364 patients. Half of these patients were randomly selected to have the tube removed and replaced with mask ventilation and half were randomly selected to continue with tube ventilation until they no longer needed breathing machine support. The mask group spent 3 fewer days receiving tube ventilation, although the overall time needing breathing machine help (mask and tube) did not change. Fewer patients in the mask group needed antibiotics for chest infections. After removing the tube, twice as many patients needed the tube again in the mask group as in the tube group. There were no differences between the groups in the number of adverse (harm) events or the number of patients who survived to leave hospital. Mask ventilation was no more expensive than tube ventilation. In conclusion, mask ventilation may be an effective alternative to continued tube ventilation when patients start to get better in intensive care.


Subject(s)
Intensive Care Units , Noninvasive Ventilation , Respiration, Artificial , Treatment Outcome , Ventilator Weaning , Cost-Benefit Analysis , Female , Humans , Male , Middle Aged , Quality of Life , Technology Assessment, Biomedical , United Kingdom
12.
Ecohealth ; 16(2): 338-345, 2019 06.
Article in English | MEDLINE | ID: mdl-31147811

ABSTRACT

The first report of giant pandas (Ailuropoda melanoleuca) infected with a novel Hepatozoon species is presented. An intraleukocytic parasite was detected via routine blood smear from a zoo-housed giant panda at the National Zoological Park. Ribosomal DNA sequences indicated a previously undescribed Hepatozoon species. Phylogenetic and distance analyses of the sequences placed it within its own branch, clustered with Old World species with carnivore (primarily ursid and mustelid) hosts. Retrospective and opportunistic testing of other individuals produced additional positive detections (17/23, 73.9%), demonstrating 100% prevalence (14/14) across five institutions. All animals were asymptomatic at time of sampling, and health implications for giant pandas remain unknown.


Subject(s)
Coccidia/genetics , Coccidiosis/veterinary , Ursidae/parasitology , Animals , Coccidiosis/parasitology , DNA, Protozoan/genetics , DNA, Ribosomal/genetics , Female , Male , Phylogeny
13.
Can J Anaesth ; 66(6): 696-705, 2019 06.
Article in English | MEDLINE | ID: mdl-30809776

ABSTRACT

BACKGROUND: Anemia is common in critically ill patients with traumatic brain injury, and often requires red blood cell transfusion. Studies suggest that prolonged storage causes lesions of the red blood cells, including a decreased ability to carry oxygen. Considering the susceptibility of the brain to hypoxemia, victims of traumatic brain injury may thus be more vulnerable to exposure to older red blood cells. METHODS: Our study aimed to ascertain whether the administration of fresh red blood cells (seven days or less) results in a better neurologic outcome compared with standard red blood cells in critically ill patients with traumatic brain injury requiring transfusion. The Age of Blood Evaluation in traumatic brain injury (ABLE-tbi) study was a nested study within the ABLE study (ISRCTN44878718). Our primary outcome was the extended Glasgow Outcome Scale (GOSe) at six months. RESULTS: In the ABLE study, 217 subjects suffered a traumatic brain injury: 110 in the fresh group, and 107 in the standard group. In the fresh group, 68 (73.1%) of the patients had an unfavourable neurologic outcome (GOSe ≤ 4) compared with 60 (64.5%) in the standard group (P = 0.21). Using a sliding dichotomy approach, we observed no overall effect of fresh red blood cells on neurologic outcome (odds ratio [OR], 1.34; 95% confidence interval [CI], 0.72 to 2.50; P = 0.35) but observed differences across prognostic bands with a decreased odds of unfavourable outcome in patients with the best prognosis at baseline (OR, 0.33; 95% CI, 0.11 to 0.96; P = 0.04) but an increased odds in those with intermediate and worst baseline prognosis (OR, 5.88; 95% CI,1.66 to 20.81; P = 0.006; and OR, 1.67; 95% CI, 0.53 to 5.30; P = 0.38, respectively). CONCLUSION: Overall, transfusion of fresh red blood cells was not associated with a better neurologic outcome at six months in critically ill patients with traumatic brain injury. Nevertheless, we cannot exclude a differential effect according to the patient baseline prognosis. TRIAL REGISTRATION: ABLE study (ISRCTN44878718); registered 22 August, 2008.


Subject(s)
Anemia/therapy , Brain Injuries, Traumatic/therapy , Erythrocyte Transfusion/methods , Erythrocytes/cytology , Adult , Aged , Anemia/etiology , Brain Injuries, Traumatic/complications , Critical Illness , Double-Blind Method , Female , Humans , Male , Middle Aged , Prognosis , Prospective Studies , Time Factors , Treatment Outcome
14.
Rev Sci Instrum ; 89(9): 093701, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30278725

ABSTRACT

A method for calibrating the dynamic torsional spring constant of cantilevers by directly measuring the thermally driven motion of the cantilever with an interferometer is presented. Random errors in calibration were made negligible (<1%) by averaging over multiple measurements. The errors in accuracy of ±5% or ±10% for both of the cantilevers calibrated in this study were limited only by the accuracy of the laser Doppler vibrometer (LDV) used to measure thermal fluctuations. This is a significant improvement over commonly used methods that result in large and untraceable errors resulting from assumptions made about the cantilever geometry, material properties, and/or hydrodynamic physics of the surroundings. Subsequently, the static torsional spring constant is determined from its dynamic counterpart after careful LDV measurements of the torsional mode shape, backed by finite element analysis simulations. A meticulously calibrated cantilever is used in a friction force microscopy experiment that measures the friction difference and interfacial shear strength (ISS) between graphene and a silicon dioxide AFM probe. Accurate calibration can resolve discrepancies between different experimental methods, which have contributed to a large scatter in the reported friction and ISS values in the literature to date.

15.
BMC Geriatr ; 18(1): 217, 2018 09 17.
Article in English | MEDLINE | ID: mdl-30223771

ABSTRACT

BACKGROUND: Delirium is a common and serious clinical syndrome which is often missed in routine clinical care. The core cognitive feature is inattention. We developed a novel bedside neuropsychological test for assessing inattention in delirium implemented on a smartphone platform (DelApp). We aim to evaluate the diagnostic performance of the DelApp in a representative cohort of older hospitalised patients. METHODS: This is a prospective study of older non-scheduled hospitalised patients (target n = 500, age ≥ 65), recruited from elderly care and acute orthopaedic wards. Exclusion criteria are: non-English speakers; severe vision or hearing impairment; photosensitive epilepsy. A structured reference standard delirium assessment based on DSM-5 criteria will be used, which includes a cognitive test battery administered by a trained assessor (Orientation-Memory-Concentration Test, Abbreviated Mental Test-10, Delirium Rating Severity Scale-Revised-98, digit span, months and days backwards, Vigilance A' test) and assessment of arousal (Observational Scale of Level of Arousal, Richmond Agitation Sedation Scale). Prior change in cognition will be documented using the Informant Questionnaire on Cognitive Decline in the Elderly. Patients will be categorized as delirium (with/without dementia), possible delirium, dementia, no cognitive impairment, or undetermined. A separate assessor (blinded to diagnosis and assessments) will administer the DelApp index test within 3 h of the reference standard assessment. The DelApp comprises assessment of arousal (score 0-4) and sustained attention (score 0-6), yielding a total score between 0 and 10 (higher score = better performance). Outcomes (length of stay, mortality and discharge location) will be collected at 12 weeks. We will evaluate a priori cutpoints derived from a previous case-control study. Measures of the accuracy of DelApp will include sensitivity, specificity, positive and negative predictive values, and area under the ROC curve. We plan repeat assessments on up to 4 occasions in a purposive subsample of 30 patients (15 delirium, 15 no delirium) to examine changes over time. DISCUSSION: This study evaluates the diagnostic test accuracy of a novel smartphone test for delirium in a representative cohort of older hospitalised patients, including those with dementia. DelApp has the potential to be a convenient, objective method of improving delirium assessment for older people in acute care. TRIAL REGISTRATION: Clinical trials.gov, NCT02590796 . Registered on 29 Oct 2015. Protocol version 5, dated 25 July 2016.


Subject(s)
Attention , Delirium/psychology , Hospitalization , Mobile Applications/standards , Neuropsychological Tests/standards , Smartphone/standards , Aged , Aged, 80 and over , Attention/physiology , Case-Control Studies , Cohort Studies , Delirium/diagnosis , Diagnostic Tests, Routine/standards , Female , Humans , Male , Prospective Studies , Surveys and Questionnaires/standards
16.
J Intensive Care Soc ; 18(1): 36-46, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28979535

ABSTRACT

BACKGROUND: Clinical trials in critical care are often resource-intense, with many unique challenges. Barriers to effective recruitment and implementation of study intervention have not been explored in a UK context. AIM: To identify facilitating factors and barriers to enrolling patients into critical care clinical trials within the UK from clinician's perspectives. METHODS: A qualitative interview study was undertaken on behalf of the National Institute of Health Research critical care specialty group, in which research active clinicians across different Clinical Research Networks were interviewed. A loosely structured interview schedule was used, based on themes generated from the literature associated with accessing critical care trials. Research teams (critical care doctors, research nurses, and trial coordinators) from hospitals from each Clinical Research Network were contacted to try to achieve representation across the UK. RESULTS: Interviews were carried out across nine UK Clinical Research Networks with a range of doctors and research nurses. All hospitals were teaching hospitals with varying research nurse numbers and allocated consultant research sessions. There were a range of six to nine ongoing clinical trials in critical care for each centre representative interviewed. Data were analysed using framework analysis, and six final themes were identified related to factors associated with: centre, unit, resources, study, clinician, and patient/family. The most commonly cited barrier to conducting clinical trials was related to resources, namely insufficient human and financial resources, leading to staff and study recruitment difficulties. Clinical uncertainty and equipoise regarding comparative merits of trials were challenging in terms of engaging critical care teams. A number of patient and family factors added complexities in terms of recruitment; however, refusal rates were generally reported as low. CONCLUSION: Flexibility in funding and employment by research teams enables continuity of studies and staff. Innovative measures to incentivise research nurses and clinical teams can help recruit more patients into trials. Research teams are highly committed to providing cover to recruit critical care trials, and a significant effort to anticipate barriers is undertaken; these endeavours are summarised to provide guidance for other teams wishing to address any potential difficulties.

17.
LGBT Health ; 4(1): 72-74, 2017 02.
Article in English | MEDLINE | ID: mdl-27673362

ABSTRACT

PURPOSE: Limited data are available on anal squamous intraepithelial lesions (ASILs) and anal human papillomavirus (HPV) infection in young, Black populations. The purpose of this study was to examine the prevalence of and relationships between ASILs and high-risk HPV infection in a young (<30 years of age), predominantly Black, men who have sex with men (MSM) population. METHODS: Results of anal cytology and HPV DNA were gathered for 83 individuals. RESULTS: Forty-two percent of individuals (35) had atypical squamous cells of undetermined significance and 33% (27) had low-grade squamous intraepithelial lesion by cytology. Only 9% tested positive for both high-risk HPV subtypes 16 and 18. CONCLUSION: Low rates of infection with both HPV types 16 and 18 may provide further evidence that we should continue to vaccinate young, Black MSM against HPV.


Subject(s)
Anus Diseases/epidemiology , Black or African American , Homosexuality, Male , Papillomavirus Infections/epidemiology , Anal Canal/pathology , Anus Diseases/complications , Anus Diseases/pathology , Anus Diseases/virology , CD4 Lymphocyte Count , Female , HIV Infections/complications , HIV Infections/epidemiology , HIV Infections/immunology , Human papillomavirus 16 , Human papillomavirus 18 , Humans , Logistic Models , Male , Papillomavirus Infections/complications , Papillomavirus Infections/immunology , Papillomavirus Infections/pathology , Retrospective Studies , Risk Factors , Transsexualism , Young Adult
19.
Rev Sci Instrum ; 87(7): 073705, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27475563

ABSTRACT

A method is presented for calibrating the higher eigenmodes (resonant modes) of atomic force microscopy cantilevers that can be performed prior to any tip-sample interaction. The method leverages recent efforts in accurately calibrating the first eigenmode by providing the higher-mode stiffness as a ratio to the first mode stiffness. A one-time calibration routine must be performed for every cantilever type to determine a power-law relationship between stiffness and frequency, which is then stored for future use on similar cantilevers. Then, future calibrations only require a measurement of the ratio of resonant frequencies and the stiffness of the first mode. This method is verified through stiffness measurements using three independent approaches: interferometric measurement, AC approach-curve calibration, and finite element analysis simulation. Power-law values for calibrating higher-mode stiffnesses are reported for several cantilever models. Once the higher-mode stiffnesses are known, the amplitude of each mode can also be calibrated from the thermal spectrum by application of the equipartition theorem.

20.
Trials ; 17(1): 318, 2016 07 16.
Article in English | MEDLINE | ID: mdl-27422026

ABSTRACT

BACKGROUND: Ventilator-acquired pneumonia (VAP) is a common reason for antimicrobial therapy in the intensive care unit (ICU). Biomarker-based diagnostics could improve antimicrobial stewardship through rapid exclusion of VAP. Bronchoalveloar lavage (BAL) fluid biomarkers have previously been shown to allow the exclusion of VAP with high confidence. METHODS/DESIGN: This is a prospective, multi-centre, randomised, controlled trial to determine whether a rapid biomarker-based exclusion of VAP results in fewer antibiotics and improved antimicrobial management. Patients with clinically suspected VAP undergo BAL, and VAP is confirmed by growth of a potential pathogen at [≥] 10(4) colony-forming units per millilitre (CFU/ml). Patients are randomised 1:1, to either a 'biomarker-guided recommendation on antibiotics' in which BAL fluid is tested for IL-1ß and IL-8 in addition to routine microbiology testing, or to 'routine use of antibiotics' in which BAL undergoes routine microbiology testing only. Clinical teams are blinded to intervention until 6 hours after randomisation, when biomarker results are reported to the clinician. The primary outcome is a change in the frequency distribution of antibiotic-free days (AFD) in the 7 days following BAL. Secondary outcome measures include antibiotic use at 14 and 28 days; ventilator-free days; 28-day mortality and ICU mortality; sequential organ failure assessment (SOFA) at days 3, 7 and 14; duration of stay in critical care and the hospital; antibiotic-associated infections; and antibiotic-resistant pathogen cultures up to hospital discharge, death or 56 days. A healthcare-resource-utilisation analysis will be calculated from the duration of critical care and hospital stay. In addition, safety data will be collected with respect to performing BAL. A sample size of 210 will be required to detect a clinically significant shift in the distribution of AFD towards more patients having fewer antibiotics and therefore more AFD. DISCUSSION: This trial will test whether a rapid biomarker-based exclusion of VAP results in rapid discontinuation of antibiotics and therefore improves antibiotic management in patients with suspected VAP. TRIAL REGISTRATION: ISRCTN65937227 . Registered on 22 August 2013. ClinicalTrials.gov, NCT01972425 . Registered on 24 October 2013.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Antimicrobial Stewardship , Bronchoalveolar Lavage Fluid/chemistry , Interleukin-1beta/analysis , Interleukin-8/analysis , Pneumonia, Bacterial/diagnosis , Pneumonia, Ventilator-Associated/diagnosis , Unnecessary Procedures , Bacteria/growth & development , Bacteria/isolation & purification , Biomarkers/analysis , Bronchoalveolar Lavage Fluid/microbiology , Clinical Protocols , Colony Count, Microbial , Hospital Mortality , Humans , Length of Stay , Organ Dysfunction Scores , Patient Selection , Pneumonia, Bacterial/drug therapy , Pneumonia, Bacterial/microbiology , Pneumonia, Bacterial/mortality , Pneumonia, Ventilator-Associated/drug therapy , Pneumonia, Ventilator-Associated/microbiology , Pneumonia, Ventilator-Associated/mortality , Predictive Value of Tests , Prospective Studies , Research Design , Respiration, Artificial , Time Factors , United Kingdom
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