194 research outputs found
Towards a lightweight mobile semantic-based approach for enhancing interaction with smart objects
This work describes a semantic extension for a user-smart object interaction model based on the ECA paradigm (Event-Condition-Action). In this approach, smart objects publish their sensing (event) and action capabilities in the cloud and mobile devices are prepared to retrieve them and act as mediators to configure personalized behaviours for the objects. In this paper, the information handled by this interaction system has been shaped according several semantic models that, together with the integration of an embedded ontological and rule-based reasoner, are exploited in order to (i) automatically detect incompatible ECA rules configurations and to (ii) support complex ECA rules definitions and execution. This semantic extension may significantly improve the management of smart spaces populated with numerous smart objects from mobile personal devices, as it facilitates the configuration of coherent ECA rules
Oporność na kwas acetylosalicylowy we wtórnej prewencji udaru mózgu
Wstęp. Autorzy zbadali czynność płytek krwi u pacjentów po udarze
mózgu leczonych kwasem acetylosalicylowym (ASA, acetylsalicylic
acid), w celu zapobieżenia kolejnemu udarowi. Okres obserwacji wynosił
1 rok.
Metoda. W badaniu prospektywnym wzięło udział 291 pacjentów,
u których po raz pierwszy włączono ASA (300 mg/d.) w celu wtórnej
prewencji udaru mózgu. Pomiary agregacji płytek wykonano po
24 godzinach, 3, 6 i 12 miesiącach od rozpoczęcia leczenia.
Wyniki. Dwudziestu jeden pacjentów (7,2%) spośród 291 uznano za
pierwotnie nieodpowiadających na ASA (początkowa niewystarczająca
inhibicja płytek), a 4,1% jako wtórnie nieodpowiadających (niewystarczająca
inhibicja płytek w czasie obserwacji). Nie stwierdzono
istotnych różnic w odniesieniu do wieku, płci, czynników ryzyka i typu
udaru między grupami pacjentów odpowiadajacych i nieodpowiadających
na leczenie ASA.
Wniosek. Oporność na ASA wśród pacjentów po udarze mózgu nie
jest zjawiskiem rzadkim. Kliniczną przydatność rutynowych testów
czynności płytek powinno się ocenić w przyszłych badaniach klinicznych
Effect of age on intraoperative cerebrovascular autoregulation and near-infrared spectroscopy-derived cerebral oxygenation
Background Age is an important risk factor for perioperative cerebral complications such as stroke, postoperative cognitive dysfunction, and delirium. We explored the hypothesis that intraoperative cerebrovascular autoregulation is less efficient and brain tissue oxygenation lower in elderly patients, thus, increasing the vulnerability of elderly brains to systemic insults such as hypotension. Methods We monitored intraoperative cerebral perfusion in 50 patients aged 18-40 and 77 patients >65 yr at two Swiss university hospitals. Mean arterial pressure (MAP) was measured continuously using a plethysmographic method. An index of cerebrovascular autoregulation (Mx) was calculated based on changes in transcranial Doppler flow velocity due to changes in MAP. Cerebral oxygenation was assessed by the tissue oxygenation index (TOI) using near-infrared spectroscopy. End-tidal CO2, O2, and sevoflurane concentrations and peripheral oxygen saturation were recorded continuously. Standardized anaesthesia was administered in all patients (thiopental, sevoflurane, fentanyl, atracurium). Results Autoregulation was less efficient in patients aged >65 yr [by 0.10 (se 0.04; P=0.020)] in a multivariable linear regression analysis. This difference was not attributable to differences in MAP, end-tidal CO2, or higher doses of sevoflurane. TOI was not significantly associated with age, sevoflurane dose, or Mx but increased with increasing flow velocity [by 0.09 (se 0.04; P=0.028)] and increasing MAP [by 0.11 (se 0.05; P=0.043)]. Conclusions Our results do not support the hypothesis that older patients' brains are more vulnerable to systemic insults. The difference of autoregulation between the two groups was small and most likely clinically insignifican
Cerebral perfusion in sepsis-associated delirium
INTRODUCTION: The pathophysiology of sepsis-associated delirium is not completely understood and the data on cerebral perfusion in sepsis are conflicting. We tested the hypothesis that cerebral perfusion and selected serum markers of inflammation and delirium differ in septic patients with and without sepsis-associated delirium. METHODS: We investigated 23 adult patients with sepsis, severe sepsis, or septic shock with an extracranial focus of infection and no history of intracranial pathology. Patients were investigated after stabilisation within 48 hours after admission to the intensive care unit. Sepsis-associated delirium was diagnosed using the confusion assessment method for the intensive care unit. Mean arterial pressure (MAP), blood flow velocity (FV) in the middle cerebral artery using transcranial Doppler, and cerebral tissue oxygenation using near-infrared spectroscopy were monitored for 1 hour. An index of cerebrovascular autoregulation was calculated from MAP and FV data. C-reactive protein (CRP), interleukin-6 (IL-6), S-100beta, and cortisol were measured during each data acquisition. RESULTS: Data from 16 patients, of whom 12 had sepsis-associated delirium, were analysed. There were no significant correlations or associations between MAP, cerebral blood FV, or tissue oxygenation and sepsis-associated delirium. However, we found a significant association between sepsis-associated delirium and disturbed autoregulation (P = 0.015). IL-6 did not differ between patients with and without sepsis-associated delirium, but we found a significant association between elevated CRP (P = 0.008), S-100beta (P = 0.029), and cortisol (P = 0.011) and sepsis-associated delirium. Elevated CRP was significantly correlated with disturbed autoregulation (Spearman rho = 0.62, P = 0.010). CONCLUSION: In this small group of patients, cerebral perfusion assessed with transcranial Doppler and near-infrared spectroscopy did not differ between patients with and without sepsis-associated delirium. However, the state of autoregulation differed between the two groups. This may be due to inflammation impeding cerebrovascular endothelial function. Further investigations defining the role of S-100beta and cortisol in the diagnosis of sepsis-associated delirium are warranted. TRIAL REGISTRATION: ClinicalTrials.gov NCT00410111
Prolonged administration of beta-lactam antibiotics - a comprehensive review and critical appraisal
Prolonged infusion of β-lactam antibiotics as either extended (over at least 2 hours) or continuous infusion is increasingly applied in intensive care units around the world in an attempt to optimise treatment with this most commonly used class of antibiotics, whose effectiveness is challenged by increasing resistance rates. The pharmacokinetics of β-lactam antibiotics in critically ill patients is profoundly altered secondary to an increased volume of distribution and the presence of altered renal function, including augmented renal clearance. This may lead to a significant decrease in plasma concentrations of β-lactam antibiotics. As a consequence, low pharmacokinetic/pharmacodynamic (PK/PD) target attainment, which is described as the percentage of time that the free drug concentration is maintained above the minimal inhibitory concentration (MIC) of the causative organism (fT>MIC), has been documented for β-lactam treatment in these patients when using standard intermittent bolus dosing, even for the most conservative target (50% fT>MIC). Prolonged infusion of β-lactams has consistently been shown to improve PK/PD target attainment, particularly in patients with severe infections. However, evidence regarding relevant patient outcomes is still limited. Whereas previous observational studies have suggested a clinical benefit of prolonged infusion, results from two recent randomised controlled trials of continuous infusion versus intermittent bolus administration of β-lactams are conflicting. In particular, the larger, double-blind placebo-controlled randomised controlled trial including 443 patients did not demonstrate any difference in clinical outcomes. We believe that a personalised approach is required to truly optimise β-lactam treatment in critically ill patients. This may include therapeutic drug monitoring with real-time adaptive feedback, rapid MIC determination and the use of antibiotic dosing software tools that incorporate patient parameters, dosing history, drug concentration and site of infection. Universal administration of β-lactam antibiotics as prolonged infusion, even if supported by therapeutic drug monitoring, is not yet ready for "prime time", as evidence for its clinical benefit is modest. There is a need for prospective randomised controlled trials that assess patient-centred outcomes (e.g. mortality) of a personalised approach in selected critically ill patients including prolonged infusion of β-lactams compared with the current standard of care
Protocolised early de-resuscitation in septic shock (REDUCE): protocol for a randomised controlled multicentre feasibility trial.
BACKGROUND
Fluid overload is associated with excess mortality in septic shock. Current approaches to reduce fluid overload include restrictive administration of fluid or active removal of accumulated fluid. However, evidence on active fluid removal is scarce. The aim of this study is to assess the efficacy and feasibility of an early de-resuscitation protocol in patients with septic shock.
METHODS
All patients admitted to the intensive care unit (ICU) with a septic shock are screened, and eligible patients will be randomised in a 1:1 ratio to intervention or standard of care.
INTERVENTION
Fluid management will be performed according to the REDUCE protocol, where resuscitation fluid will be restricted to patients showing signs of poor tissue perfusion. After the lactate has peaked, the patient is deemed stable and assessed for active de-resuscitation (signs of fluid overload). The primary objective of this study is the proportion of patients with a negative cumulative fluid balance at day 3 after ICU. Secondary objectives are cumulative fluid balances throughout the ICU stay, number of patients with fluid overload, feasibility and safety outcomes and patient-centred outcomes. The primary outcome will be assessed by a logistic regression model adjusting for the stratification variables (trial site and chronic renal failure) in the intention-to-treat population.
ETHICS AND DISSEMINATION
The study was approved by the respective ethical committees (No 2020-02197). The results of the REDUCE trial will be published in an international peer-reviewed medical journal regardless of the results.
TRIAL REGISTRATION NUMBER
ClinicalTrials.gov, NCT04931485
EGFR-targeted TRAIL and a Smac mimetic synergize to overcome apoptosis resistance in KRAS mutant colorectal cancer cells
TRAIL is a death receptor ligand that induces cell death preferentially in tumor cells. Recombinant soluble TRAIL, however, performs poorly as an anti-cancer therapeutic because oligomerization is required for potent biological activity. We previously generated a diabody format of tumor-targeted TRAIL termed DbαEGFR-scTRAIL, comprising single-stranded TRAIL molecules (scTRAIL) and the variable domains of a humanized variant of the EGFR blocking antibody Cetuximab. Here we define the bioactivity of DbαEGFR-scTRAIL with regard to both EGFR inhibition and TRAIL receptor activation in 3D cultures of Caco-2 colorectal cancer cells, which express wild-type K-Ras. Compared with conventional 2D cultures, Caco-2 cells displayed strongly enhanced sensitivity toward DbαEGFR-scTRAIL in these 3D cultures. We show that the antibody moiety of DbαEGFR-scTRAIL not only efficiently competed with ligand-induced EGFR function, but also determined the apoptotic response by specifically directing DbαEGFR-scTRAIL to EGFR-positive cells. To address how aberrantly activated K-Ras, which leads to Cetuximab resistance, affects DbαEGFR-scTRAIL sensitivity, we generated stable Caco-2tet cells inducibly expressing oncogenic K-RasG12V. In the presence of doxycycline, these cells showed increased resistance to DbαEGFR-scTRAIL, associated with the elevated expression of the anti-apoptotic proteins cIAP2, Bcl-xL and FlipS. Co-treatment of cells with the Smac mimetic SM83 restored the DbαEGFR-scTRAIL-induced apoptotic response. Importantly, this synergy between DbαEGFR-scTRAIL and SM83 also translated to 3D cultures of oncogenic K-Ras expressing HCT-116 and LoVo colorectal cancer cells. Our findings thus support the notion that DbαEGFR-scTRAIL therapy in combination with apoptosis-sensitizing agents may be promising for the treatment of EGFR-positive colorectal cancers, independently of their KRAS status
Ambient-aware continuous care through semantic context dissemination
Background: The ultimate ambient-intelligent care room contains numerous sensors and devices to monitor the patient, sense and adjust the environment and support the staff. This sensor-based approach results in a large amount of data, which can be processed by current and future applications, e. g., task management and alerting systems. Today, nurses are responsible for coordinating all these applications and supplied information, which reduces the added value and slows down the adoption rate. The aim of the presented research is the design of a pervasive and scalable framework that is able to optimize continuous care processes by intelligently reasoning on the large amount of heterogeneous care data.
Methods: The developed Ontology-based Care Platform (OCarePlatform) consists of modular components that perform a specific reasoning task. Consequently, they can easily be replicated and distributed. Complex reasoning is achieved by combining the results of different components. To ensure that the components only receive information, which is of interest to them at that time, they are able to dynamically generate and register filter rules with a Semantic Communication Bus (SCB). This SCB semantically filters all the heterogeneous care data according to the registered rules by using a continuous care ontology. The SCB can be distributed and a cache can be employed to ensure scalability.
Results: A prototype implementation is presented consisting of a new-generation nurse call system supported by a localization and a home automation component. The amount of data that is filtered and the performance of the SCB are evaluated by testing the prototype in a living lab. The delay introduced by processing the filter rules is negligible when 10 or fewer rules are registered.
Conclusions: The OCarePlatform allows disseminating relevant care data for the different applications and additionally supports composing complex applications from a set of smaller independent components. This way, the platform significantly reduces the amount of information that needs to be processed by the nurses. The delay resulting from processing the filter rules is linear in the amount of rules. Distributed deployment of the SCB and using a cache allows further improvement of these performance results
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