Intracerebral haemorrhage, anticoagulation and mechanical heart valves: what should I do next?

Life-long oral anticoagulant therapy is recommended to all patients with mechanical heart valves to reduce the incidence of thromboembolic events. However, intracerebral haemorrhage is the fatal complication associated with anticoagulation, with an estimated 6-month mortality of 67%. (1) The incidence of cerebral bleeding while on anticoagulation is 0.3-0.7%/year, with as many as 85% of survivors left with permanent neurological deficits. (2) Difficulties in management arise when anticoagulation is temporarily discontinued as mechanical valves, particularly mitral, are exposed to significant thromboembolic and valve dysfunction risk. The decision on when to appropriately restart anticoagulation needs to be balanced with the risk of precipitating further cerebral haemorrhage. There are currently no guidelines on the optimal time to start anticoagulation. We describe a case of the management approach implemented in a patient with a mechanical valve presenting to the emergency department with an acute intracerebral haemorrhage.

Light sources and cameras for standard in vitro membrane potential and high-speed ion imaging

Membrane potential and fast ion imaging are now standard optical techniques routinely used to record dynamic physiological signals in several preparations in vitro. Although detailed resolution of optical signals can be improved by confocal or two-photon microscopy, high spatial and temporal resolution can be obtained using conventional microscopy and affordable light sources and cameras. Thus, standard wide-field imaging methods are still the most common in research laboratories and can often produce measurements with a signal-to-noise ratio that is superior to other optical approaches. This paper seeks to review the most important instrumentation used in these experiments, with particular reference to recent technological advances. We analyse in detail the optical constraints dictating the type of signals that are obtained with voltage and ion imaging and we discuss how to use this information to choose the optimal apparatus. Then, we discuss the available light sources with specific attention to light emitting diodes and solid state lasers. We then address the current state-of-the-art of available charge coupled device, electron multiplying charge coupled device and complementary metal oxide semiconductor cameras and we analyse the characteristics that need to be taken into account for the choice of optimal detector. Finally, we conclude by discussing prospective future developments that are likely to further improve the quality of the signals expanding the capability of the techniques and opening the gate to novel applications.

Wild birds carry similar Salmonella enterica serovar Typhimurium strains to those found in domestic animals and livestock

The objective of this study was to investigate the hypothesis that some sporadic Salmonella infections in domesticated animals may be associated with Salmonella infections originating from garden birds. Phage type and antimicrobial resistance details of isolates of S. Typhimurium obtained from wild birds were comparable with those from S. Typhimurium infections from domesticated animals or livestock between 2002 and 2010. A small panel of S. Typhimurium isolates (n=37) were characterised by multilocus variable number of tandem repeats analysis (MLVA), pulsed field gel electrophoresis (PFGE) and phage type. The MLVA-PFGE data clustered the strains according to phage type (DT40 or DT56). Within each group there were strains from wild birds and domesticated animals or livestock with MLVA profiles having up to 100% similarity. The results from this study therefore lend support to the hypothesis that Salmonella infections in domesticated animals could be caused by infections carried by wild birds.