853 research outputs found

    Human Cortical Traveling Waves: Dynamical Properties and Correlations with Responses

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    The spatiotemporal behavior of human EEG oscillations is investigated. Traveling waves in the alpha and theta ranges are found to be common in both prestimulus and poststimulus EEG activity. The dynamical properties of these waves, including their speeds, directions, and durations, are systematically characterized for the first time, and the results show that there are significant changes of prestimulus spontaneous waves in the presence of an external stimulus. Furthermore, the functional relevance of these waves is examined by studying how they are correlated with reaction times on a single trial basis; prestimulus alpha waves traveling in the frontal-to-occipital direction are found to be most correlated to reaction speeds. These findings suggest that propagating waves of brain oscillations might be involved in mediating long-range interactions between widely distributed parts of human cortex

    Predictive value of cell-surface markers in infections in critically ill patients: protocol for an observational study (ImmuNe FailurE in Critical Therapy (INFECT) Study).

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    INTRODUCTION: Critically ill patients are at high risk of nosocomial infections, with between 20% and 40% of patients admitted to the intensive care unit (ICU) acquiring infections. These infections result in increased antibiotic use, and are associated with morbidity and mortality. Although critical illness is classically associated with hyperinflammation, the high rates of nosocomial infection argue for an importance of effect of impaired immunity. Our group recently demonstrated that a combination of 3 measures of immune cell function (namely neutrophil CD88, monocyte HLA-DR and % regulatory T cells) identified a patient population with a 2.4-5-fold greater risk for susceptibility to nosocomial infections. METHODS AND ANALYSIS: This is a prospective, observational study to determine whether previously identified markers of susceptibility to nosocomial infection can be validated in a multicentre population, as well as testing several novel markers which may improve the risk of nosocomial infection prediction. Blood samples from critically ill patients (those admitted to the ICU for at least 48 hours and requiring mechanical ventilation alone or support of 2 or more organ systems) are taken and undergo whole blood staining for a range of immune cell surface markers. These samples undergo analysis on a standardised flow cytometry platform. Patients are followed up to determine whether they develop nosocomial infection. Infections need to meet strict prespecified criteria based on international guidelines; where these criteria are not met, an adjudication panel of experienced intensivists is asked to rule on the presence of infection. Secondary outcomes will be death from severe infection (sepsis) and change in organ failure. ETHICS AND DISSEMINATION: Ethical approval including the involvement of adults lacking capacity has been obtained from respective English and Scottish Ethics Committees. Results will be disseminated through presentations at scientific meetings and publications in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02186522; Pre-results.Innovate UK (formerly Technology Strategy Board) (Grant ID: 15457-108136), Becton Dickinson bioscience, NHS Lothian via the Edinburgh Health Services Research Unit, National Institute of Academic AnaesthesiaThis is the final version of the article. It first appeared from BMJ Publishing Group via http://dx.doi.org/10.1136/bmjopen-2016-01132

    Predicting risk of cardiovascular events 1 to 3 years post-myocardial infarction using a global registry.

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    BACKGROUND: Risk prediction tools are lacking for patients with stable disease some years after myocardial infarction (MI). HYPOTHESIS: A practical long-term cardiovascular risk index can be developed. METHODS: The long-Term rIsk, Clinical manaGement and healthcare Resource utilization of stable coronary artery dISease in post-myocardial infarction patients prospective global registry enrolled patients 1 to 3 years post-MI (369 centers; 25 countries), all with ≥1 risk factor (age ≥65 years, diabetes mellitus requiring medication, second prior MI, multivessel coronary artery disease, or chronic non-end-stage kidney disease [CKD]). Self-reported health was assessed with EuroQoL-5 dimensions. Multivariable Poisson regression models were used to determine key predictors of the primary composite outcome (MI, unstable angina with urgent revascularization [UA], stroke, or all-cause death) over 2 years. RESULTS: The primary outcome occurred in 621 (6.9%) of 9027 eligible patients: death 295 (3.3%), MI 195 (2.2%), UA 103 (1.1%), and stroke 58 (0.6%). All events accrued linearly. In a multivariable model, 11 significant predictors of primary outcome (age ≥65 years, diabetes, second prior MI, CKD, history of major bleed, peripheral arterial disease, heart failure, cardiovascular hospitalization (prior 6 months), medical management (index MI), on diuretic, and poor self-reported health) were identified and combined into a user-friendly risk index. Compared with lowest-risk patients, those in the top 16% had a rate ratio of 6.9 for the primary composite, and 18.7 for all-cause death (overall c-statistic; 0.686, and 0.768, respectively). External validation was performed using the Australian Cooperative National Registry of Acute Coronary Care, Guideline Adherence and Clinical Events registry (c-statistic; 0.748, and 0.849, respectively). CONCLUSIONS: In patients >1-year post-MI, recurrent cardiovascular events and deaths accrue linearly. A simple risk index can stratify patients, potentially helping to guide management

    Synergies, tensions and challenges in HIV prevention, treatment and cure research: exploratory conversations with HIV experts in South Africa

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    Background: The ethical concerns associated with HIV prevention and treatment research have been widely explored in South Africa over the past 3 decades. However, HIV cure research is relatively new to the region and significant ethical and social challenges are anticipated. There has been no published empirical enquiry in Africa into key informant perspectives on HIV cure research. Consequently, this study was conducted to gain preliminary data from South African HIV clinicians, researchers and activists. Methods: In-depth interviews were conducted on a purposive sample of fourteen key informants in South Africa. Audiotaped interviews were transcribed verbatim with concurrent thematic analysis. The perspectives of HIV clinicians, researchers and activists were captured. Analyst triangulation occurred as the data were analysed by three authors independently. Results: The rapid evolution of HIV cure research agendas was prominent with participants expressing some concern that the global North was driving the cure agenda. Participants described a symbiotic relationship between cure, treatment and prevention research necessitating collaboration. Assessing and managing knowledge and expectations around HIV cure research emerged as a central theme related to challenges to constructing ‘cure’ - how patients understand the idea of cure is important in explaining the complexity of cure research especially in the South African context where understanding of science is often challenging. Managing expectations and avoiding curative misconception will have implications for consent processes. Unique strategies in cure research could include treatment interruption, which has the potential to create therapeutic and ethical conflict and will be perceived as a significant risk. Ethical challenges in cure research will impact on informed consent and community engagement. Conclusions: It was encouraging to note the desire for synergy amongst researchers and clinicians working in the fields of prevention, treatment and cure. Translation of complex HIV cure science into lay language is critical. Moving forward, RECs must be adequately constituted with scientific expertise and community representation when reviewing cure protocols. It is hoped that knowledge and resource sharing in the context of collaboration between research scientists working in cure and those working in treatment and prevention will accelerate progress towards cur

    Cell-surface signatures of immune dysfunction risk-stratify critically ill patients: INFECT study.

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    PURPOSE: Cellular immune dysfunctions, which are common in intensive care patients, predict a number of significant complications. In order to effectively target treatments, clinically applicable measures need to be developed to detect dysfunction. The objective was to confirm the ability of cellular markers associated with immune dysfunction to stratify risk of secondary infection in critically ill patients. METHODS: Multi-centre, prospective observational cohort study of critically ill patients in four UK intensive care units. Serial blood samples were taken, and three cell surface markers associated with immune cell dysfunction [neutrophil CD88, monocyte human leucocyte antigen-DR (HLA-DR) and percentage of regulatory T cells (Tregs)] were assayed on-site using standardized flow cytometric measures. Patients were followed up for the development of secondary infections. RESULTS: A total of 148 patients were recruited, with data available from 138. Reduced neutrophil CD88, reduced monocyte HLA-DR and elevated proportions of Tregs were all associated with subsequent development of infection with odds ratios (95% CI) of 2.18 (1.00-4.74), 3.44 (1.58-7.47) and 2.41 (1.14-5.11), respectively. Burden of immune dysfunction predicted a progressive increase in risk of infection, from 14% for patients with no dysfunction to 59% for patients with dysfunction of all three markers. The tests failed to risk stratify patients shortly after ICU admission but were effective between days 3 and 9. CONCLUSIONS: This study confirms our previous findings that three cell surface markers can predict risk of subsequent secondary infection, demonstrates the feasibility of standardized multisite flow cytometry and presents a tool which can be used to target future immunomodulatory therapies. TRIAL REGISTRATION: The study was registered with clinicaltrials.gov (NCT02186522).The study was funded by Innovate UK (Sepsis 2: 101193), BD Biosciences and the National Institute for Academic Anaesthesia. Dr Conway Morris is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z). Dr Shankar-Hari is supported by the National Institute for Health Research Clinician Scientist Award (CS-2016-16- 011)

    Early PREdiction of sepsis using leukocyte surface biomarkers: the ExPRES-sepsis cohort study.

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    PURPOSE: Reliable biomarkers for predicting subsequent sepsis among patients with suspected acute infection are lacking. In patients presenting to emergency departments (EDs) with suspected acute infection, we aimed to evaluate the reliability and discriminant ability of 47 leukocyte biomarkers as predictors of sepsis (Sequential Organ Failure Assessment score ≥ 2 at 24 h and/or 72 h following ED presentation). METHODS: In a multi-centre cohort study in four EDs and intensive care units (ICUs), we standardised flow-cytometric leukocyte biomarker measurement and compared patients with suspected acute infection (cohort-1) with two comparator cohorts: ICU patients with established sepsis (cohort-2), and ED patients without infection or systemic inflammation but requiring hospitalization (cohort-3). RESULTS: Between January 2014 and February 2016, we recruited 272, 59 and 75 patients to cohorts 1, 2, and 3, respectively. Of 47 leukocyte biomarkers, 14 were non-reliable, and 17 did not discriminate between the three cohorts. Discriminant analyses for predicting sepsis within cohort-1 were undertaken for eight neutrophil (cluster of differentiation antigens (CD) CD15; CD24; CD35; CD64; CD312; CD11b; CD274; CD279), seven monocyte (CD35; CD64; CD312; CD11b; HLA-DR; CD274; CD279) and a CD8 T-lymphocyte biomarker (CD279). Individually, only higher neutrophil CD279 [OR 1.78 (95% CI 1.23-2.57); P = 0.002], higher monocyte CD279 [1.32 (1.03-1.70); P = 0.03], and lower monocyte HLA-DR [0.73 (0.55-0.97); P = 0.03] expression were associated with subsequent sepsis. With logistic regression the optimum biomarker combination was increased neutrophil CD24 and neutrophil CD279, and reduced monocyte HLA-DR expression, but no combination had clinically relevant predictive validity. CONCLUSIONS: From a large panel of leukocyte biomarkers, immunosuppression biomarkers were associated with subsequent sepsis in ED patients with suspected acute infection. CLINICAL TRIAL REGISTRATION: NCT02188992.The study was funded by Innovate UK (Sepsis 2: 101193). Dr Shankar-Hari is supported by the National Institute for Health Research Clinician Scientist Award (CS-2016-16-011). Dr Conway Morris is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z)

    Two-year outcomes among stable high-risk patients following acute MI. Insights from a global registry in 25 countries.

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    BACKGROUND: Evidence is lacking on long-term outcomes in unselected patients surviving the first year following myocardial infarction (MI). METHODS AND RESULTS: The TIGRIS (long-Term rIsk, clinical manaGement and healthcare Resource utilization of stable coronary artery dISease in post-myocardial infarction patients) prospective registry enrolled 9176 eligible patients aged ≥50 years, 1-3 years post-MI, from 25 countries. All had ≥1 risk factor: age ≥ 65 years, diabetes mellitus, second prior MI, multivessel coronary artery disease, chronic kidney disease (CKD). Primary outcome was a composite of MI, unstable angina with urgent revascularization, stroke, or all-cause death at 2-year follow-up. Bleeding requiring hospitalization was also recorded. 9027 patients (98.4%) provided follow-up data: the primary outcome occurred in 621 (7.0%), all-cause mortality in 295 (3.3%), and bleeding in 109 (1.2%) patients. Events accrued linearly over time. In multivariable analyses, qualifying risk factors were associated with increased risk of primary outcome (incidence rate ratio [RR] per 100 patient-years [95% confidence interval]): CKD 2.06 (1.66, 2.55), second prior MI 1.71 (1.38, 2.10), diabetes mellitus 1.63 (1.39, 1.92), age ≥ 65 years 1.53 (1.28, 1.83), and multivessel disease 1.24 (1.05, 1.48). Risk of bleeding events was greater in older patients (vs <65 years) 65-74 years 2.68 (1.53, 4.70), ≥75 years 4.62 (2.57, 8.28), and those with CKD 1.99 (1.18, 3.35). CONCLUSION: In stable patients recruited 1-3 years post-MI, recurrent cardiovascular and bleeding events accrued linearly over 2 years. Factors independently predictive of ischemic and bleeding events were identified, providing a context for deciding on treatment options
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