Association between P-selectin levels and left atrial blood stasis in patients with nonvalvular atrial fibrillation

BACKGROUND

P-selectin - a biomarker of platelet and endothelial cell activation is elevated in patients with non-valvular atrial fibrillation (NVAF). However, the association between sP-selectin level and thromboembolic complications in NVAF patients remains controversial. We tested the hypothesis that plasma soluble P-selectin (sPSL) level correlates with the measures of left atrial blood stasis in NVAF.

METHODS

Plasma sPSL concentration was measured using solid-phase ELISA in 103 NVAF patients (age 63 ± 14 years; 26% women) and 48 normal sinus rhythm controls (NSR; age 64 ± 14 years; 41% women) who were not on aspirin. Within the group of NVAF cases, 27 had no spontaneous echocardiographic contrast (SEC) detected by transesophageal echocardiography, 31had mild SEC, 15 moderate, 20 severe, and 10 patients had left atrial appendage thrombus (LAAT).

RESULTS

The median soluble sPSL level was higher in NVAF cases compared to NSR controls [(interquartile range) 26 (20-32) ng/mL vs 22 (15-29) ng/mL, p = 0.0045]. Only NVAF patients with CHA₂DS₂-VASc score ≥ 1 had higher sPSL level compared to NSR controls. Patients with severe SEC had significantly higher sPSL levels [32 (24-38) ng/mL] compared to all other NVAF patients (p = 0.0042) and to NSR controls (p < 0.0001). Also NVAF patients with LAAT had higher sPSL level compared to NSR controls.

CONCLUSIONS

There is a direct correlation between p-selectin level and severe blood stasis in the left atrium. Only NVAF patients with CHA₂DS₂-VASc score ≥ 1 or with LAAT had higher sPSL level compared to NSR controls.

Using Video Acquired from an Unmanned Aerial Vehicle (UAV) to Measure Fracture Orientation in an Open-Pit Mine

This project explored the feasibility of using video images acquired with an unmanned aerial vehicle (UAV) to obtain three-dimensional (3D) point clouds using structure from motion (SfM) software. Missions were flown using an Aeryon Scout: a lightweight, vertical take-off and landing quadrotor micro UAV with a miniature video camera. The initial mission captured urban scene images that were used to assess system performance while the main mission focused on rock walls where 3D images were used to successfully measure fracture orientations. Point clouds generated from this combination of technologies were sparse, but in the future, improvements in the resolution of original video images would cascade through the processing and improve the overall results. Such a system could have a multitude of applications in the mining industry, contributing to both safety and financial considerations.

Environmental flows and water quality objectives for the River Murray

Over the past decade, there intense consideration of managing flows in the River Murray to provide environmental benefits. In 1990 the Murray-Darling Basin Ministerial Council adopted a water quality policy: To maintain and, where necessary, improve existing water quality in the rivers of the Murray-Darling Basin for all beneficial uses - agricultural, environmental, urban, industrial and recreational, and in 1994 a flow policy: To maintain and where necessary improve existing flow regimes in the waterways of the Murray-Darling Basin to protect and enhance the riverine environment. The Audit of Water Use followed in 1995, culminating in the decision of the Ministerial Council to implement an interim cap on new diversions for consumptive use (the "Cap") in a bid to halt declining river health. In March 1999 the Environmental Flows and Water Quality Objectives for the River Murray Project (the Project) was set up, primarily to establish be developed that aims to achieve a sustainable river environment and water quality, in accordance with community needs, and including an adaptive approach to management and operation of the River. It will lead to objectives for water quality and environmental flows that are feasible, appropriate, have the support of the scientific, management and stakeholder communities, and carry acceptable levels of risk. This paper describes four key aspects of the process being undertaken to determine the objectives, and design the flow options that will meet those objectives: establishment of an appropriate technical, advisory and administrative framework; establishing clear evidence for regulation impacts; undergoing assessment of environmental flow needs; and filling knowledge gaps. A review of the impacts of flow regulation on the health of the River Murray revealed evidence for decline, but the case for flow regulation as the main cause is circumstantial or uncertain. This is to be expected, because the decline of the River Murray results from many factors acting over a long period. Also, the health of the river varies along its length, from highly degraded to reasonably healthy, so it is clear that different approaches will be needed in the various river zones, with some problems requiring reach or even point scale solutions. Environmental flow needs have been determined through two major Expert Panel reports that identified the ecological priorities for the river. The next step is to translate these needs into feasible flow management actions that will provide the necessary hydrological conditions. Several investigations are underway to recommend options for flow management. Two important investigations are described in this paper: how to enhance flows to wetlands of national and international significance, and how to physically alter or change the operation of structures (including a dam, weir, lock, regulator, barrage or causeway), to provide significant environmental benefits. Early modelling suggests that the only option which has a positive environmental effect in all zones of the River is a reduction in overall water consumption.

The effects of remifentanil on haemodynamic stability during rigid bronchoscopy

We examined the effect of remifentanil on the haemodynamic response to rigid bronchoscopy in 22 adult ASA 2-4 patients, randomly allocated to receive 1.0 microg.kg-1 remifentanil over 1 min followed by 0.5 microg.kg-1.min-1 (remifentanil group) or 2.0 microg.kg-1 fentanyl followed by a saline infusion (control group). Following the initial infusion, all patients received a sleep dose of propofol followed by rocuronium 0.6 mg.kg-1 and their lungs were ventilated using a Sander's injector attached to the rigid bronchoscope. Direct arterial blood pressures, heart rate and ST segment changes on the CM5 lead configuration of the electrocardiograph were measured at 1-min intervals from before induction of anaesthesia until the end of bronchoscopy. Arterial pressures and heart rate were similar in the two groups before and after induction of anaesthesia. Remifentanil attenuated the haemodynamic response to bronchoscopy (p < 0.05 for increases in arterial pressures and heart rate). Four patients in the remifentanil group had ST segment depression compared with eight patients in the control group, but this was not statistically significant.

Work stress among community psychiatric nurses

This article examines the findings of a research study on the levels and sources of stress among 60 community psychiatric nurses (CPNs) from six health authorities in the midlands area. This three-way comparative study explores the stress levels experienced by CPNs working with primary clients. The hypothesis that higher levels of stress is experienced by CPNs working with the severely mentally ill is supported. The stress levels experienced did appear to vary with the type of clients catered for. Using a questionnaire designed to measure individual variables, CPNs working with the severely mentally ill reported higher caseloads, less training, lack of respect and understanding of their role by others and the need for more supervision and support. Forty per cent of CPNs were found to be stressed according to the General Health Questionnaire (GHQ 28). While there is debate about where CPNs should focus their interventions and which clients should be prioritized, it appears that working with the severely mentally ill is less attractive and more stressful to CPNs. The results and suggestions for further research are highlighted in this article.

Drainage of a pancreatic pseudocyst: an unusual complication

A 34-year-old white woman had external drainage of a pancreatic pseudocyst. During sinography, contrast medium filled perigastric varices, causing septic shock. From this experience, we believe that although sinograms are helpful, they should be preceded by prophylactic administration of antibiotics and that contrast material should be sterile. The drainage catheter should be removed as soon as possible.

The nonarterial origin of cystic adventitial disease of the popliteal artery in two patients

Two patients with compression of a popliteal artery caused by periarticular cystic lesions of the knee joint are described. Both gave the usual history of complete resolution of intermittent claudication for a period of months, followed by recurrence. The authors feel that this is a significant historical feature in this condition.