Volatile anaesthetics and positive pressure ventilation reduce left atrial performance: a transthoracic echocardiographic study in young healthy adults

Background Animal and in vitro studies suggest that volatile anaesthetics affect left atrial (LA) performance. We hypothesized that human LA pump function and dimensions are altered by volatile anaesthetics in vivo. Methods We performed transthoracic echocardiographic (TTE) measurements in 59 healthy subjects (aged 18-48 yr) undergoing minor surgery under general anaesthesia. The unpremedicated patients were randomly assigned to anaesthesia with sevoflurane, desflurane, or isoflurane. TTE examinations were performed at baseline and after induction of anaesthesia and upon placement of a laryngeal mask during spontaneous breathing. After changing to intermittent positive pressure ventilation (IPPV), an additional TTE was performed. The study focused on the velocity-time integral of late peak transmitral inflow velocity (AVTI) and maximum LA volume. Results We found no evidence for relevant differences in the effects of the three volatile anaesthetics. AVTI decreased significantly from 4.1 (1.2) cm at baseline to 3.2 (1.1) cm during spontaneous breathing of 1 minimum alveolar concentration of volatile anaesthetics. AVTI decreased further to 2.8 (1.0) cm after changing to IPPV. The maximum LA volume was 45.4 (18.6) cm3 at baseline and remained unchanged during spontaneous breathing but decreased to 34.5 (16.7) cm3 during IPPV. Other parameters of LA pump function and dimensions decreased similarly. Conclusions Volatile anaesthetics reduced active LA pump function in humans in vivo. Addition of IPPV decreased LA dimensions and further reduced LA pump function. Effects in vivo were less pronounced than previously found in in vitro and animal studies. Further studies are warranted to evaluate the clinical implications of these findings. Clinical trial registration NCT002445

DNA-Sequence Variation Among Schistosoma mekongi Populations and Related Taxa; Phylogeography and the Current Distribution of Asian Schistosomiasis

Schistosomiasis is a disease caused by parasitic worms of the genus Schistosoma. In the lower Mekong river, schistosomiasis in humans is called Mekong schistosomiasis and is caused by Schistosoma mekongi. In the past, Mekong schistosomiasis was known only from the lower Mekong river. Here DNA-sequence variation is used to study the relationships and history of populations of S. mekongi. Populations from other rivers are compared and shown to be S. mekongi, thus confirming that this species is not restricted to only a small section of one river. The dates of divergence among populations are also estimated. Prior to this study it was assumed that S. mekongi originated in Yunnan, China, migrated southwards across Laos and into Cambodia, later becoming extinct in Laos (due to conditions unsuitable for transmission). In contrast, the dates estimated here indicate that S. mekongi entered Cambodia from Vietnam, 2.5–1 Ma. The pattern of genetic variation fits better with a more recent, and ongoing, northwards migration from Cambodia into Laos. The implications are that Mekong schistosomiasis is more widespread than once thought and that the human population at risk is up to 10 times greater than originally estimated. There is also an increased possibility of the spread of Mekong schistosomiasis across Laos

Multi-objective optimization of sub-assemblies design towards static mechanical equilibrium of sodium-cooled fast reactor core

International audienceIn the framework of Sodium-cooled Fast Reactors, core design studies are performed at CEA. A new methodology based on core multi-objective optimization is proposed taking into account the geometrical uncertainties on sub-assemblies regarding manufacturing tolerances for core static mechanical equilibrium analysis. This methodology relies on feedback from past reactors, especially PHENIX and SUPERPHENIX. As an example, the optimization is performed on a reduced number of parameters (distance across flats of pads, natural core restraint by reflectors sub-assemblies, pads axial position and stiffness).The thermal-mechanics core HARMONIE V2 code and the uncertainties URANIE platform are applied to define a first set of optimal features of the sub-assemblies. The core behaviour is analysed during nominal conditions, fuel handling operations and unprotected transients (i.e. with complete failure of all automatic shutdown systems).First results tend towards to give priority to high pads flexibility in order to minimise friction between sub-assemblies during handling operations. Pads on the whole of sub-assemblies, including reflectors, should be preferred for core restraint requirements. The effect of pads axial position over the core static mechanical equilibrium is limited, but pads located close to the top of fuel pins favour the pads effect during an unprotected transient

Computer-mediated communication in English for specific purposes: A case study with computer science students at Universiti Teknologi Malaysia

This paper will describe an ESP approach to the design and implementation of computer-mediated communication (CMC) tasks for computer science students at Universiti Teknologi Malaysia, and discuss the effectiveness of the chat feature of Windows NetMeeting as a tool for developing specified language skills. CMC tasks were set within a programme of sustained-content language instruction (SCLI), a variation on the content-based instruction approach. Various studies have confirmed the potential of SCLI as a means of familiarising language learners with academic genres and the language skills expected of them in the content classroom. To date, however, there has been little or no research into the use of CMC within SCLI. We found that students who followed a programme of SCLI using CMC ESP tasks made significant improvements in their oral communication skills, and also achieved higher scores than their peers in a computer science project undertaken in the semester following the treatment

At-risk opioid use following a trauma-related emergency department visit: The role of emergency department opioid analgesics

Background and Objectives: Whether ED opioid prescriptions (Rx) lead to future problematic opioid use remains controversial and inadequately characterized. This study examines the relationship between ED opioid analgesics (via prescription (Rx) or ED administration) and self-reported opioid use during a 3-month period after a traumatic event. We hypothesized that ED opioid analgesic exposure would be associated with subsequent at-risk opioid use. Methods: This retrospective cohort study secondarily analyzed data available from the AURORA multi-center (29 urban EDs), prospective, longitudinal cohort study which enrolled adult, trauma (psychological and/or physical) survivors. Patients who are not chronically using opioids and were discharged home or hospitalized for \u3c 3 days were eligible for enrollment. Self-reported opioid analgesic use and pain scores were recorded at baseline, 2 and 8 weeks, and 3 months. We excluded from analysis those reporting any non-medical substance use (e.g., heroin, opiates) in the 30 days before enrollment and those with missing or incomplete opioid use/exposure or pain scores. We used multivariable logistic regression to assess the relationship between ED opioid exposure and at-risk opioid use, defined as any non-medical opioid use after initial ED visit or opioid analgesic use at 3-month follow-up. Results: Of 917 included subjects, at-risk opioid use occurred in 35/641 (6%) without an ED opioid analgesic exposure, 4/17 (24%) with ED opioid Rx only, 21/159 (13%) with ED opioid administration only, and 16/110 (15%) with both ED administration and Rx. In the multivariable model, at-risk opioid use was associated with ED opioid Rx only (OR 3.4, 95% CI 1.002-11.7), ED administered opioids only (OR 1.9, CI 1.1-3.5), and both ED administration and Rx opioid (OR 2.0, CI 1.001-3.9), controlling for patient age, Rx opioid use prior to enrollment, pain at initial ED visit, and moderate or severe pain at 3 months. Conclusion: Exposure to ED opioids was associated with increased risk of potentially problematic opioid use within three months in a geographically diverse cohort of trauma patients. Study limitations prevent conclusions about causality and the degree to which ED opioid exposures were preventable. Nonetheless, these results support the need for prospective study focused specifically on the long-term consequences of ED opioid analgesic exposure