Between roost contact is essential for maintenance of European bat lyssavirus type-2 in Myotis daubentonii bat reservoir: 'The Swarming Hypothesis'.

Many high-consequence human and animal pathogens persist in wildlife reservoirs. An understanding of the dynamics of these pathogens in their reservoir hosts is crucial to inform the risk of spill-over events, yet our understanding of these dynamics is frequently insufficient. Viral persistence in a wild bat population was investigated by combining empirical data and in-silico analyses to test hypotheses on mechanisms for viral persistence. A fatal zoonotic virus, European Bat lyssavirus type 2 (EBLV-2), in Daubenton's bats (Myotis daubentonii) was used as a model system. A total of 1839 M. daubentonii were sampled for evidence of virus exposure and excretion during a prospective nine year serial cross-sectional survey. Multivariable statistical models demonstrated age-related differences in seroprevalence, with significant variation in seropositivity over time and among roosts. An Approximate Bayesian Computation approach was used to model the infection dynamics incorporating the known host ecology. The results demonstrate that EBLV-2 is endemic in the study population, and suggest that mixing between roosts during seasonal swarming events is necessary to maintain EBLV-2 in the population. These findings contribute to understanding how bat viruses can persist despite low prevalence of infection, and why infection is constrained to certain bat species in multispecies roosts and ecosystems.

Comparison of cooling systems during islet purification.

Islet isolation is a complex procedure that includes digestion and purification of pancreatic tissue. As we move towards clinical regulatory control and standardization, understanding of the detailed stages of the procedure have become increasingly important. Purification on a COBE 2991 density gradient allows human islets to be separated from a large volume of acinar tissue. Cooling the gradient and tissue is thought to be important to reduce metabolic activity but cooling systems for the gradient are expensive, with limited availability. In this study, the efficiency of cooling methods for the COBE 2991 cell separator has been investigated. The two cooling systems were: a) COBE 2991 modified internally to allow coolant (polyethylene glycol) from a chiller to circulate either side of the spindle and around the bowl (original system), and b) an air-cooled system using an air conditioner to blow cold air into the bowl from above (air cooler system). Cooling required 20 min for the original system and temperature was stabilized within 4-7 degrees C. The air system cooled rapidly but was not stable. There was an increase in the temperature of the medium with using both systems during centrifugation because of heat generated by the COBE machine; however, the temperature of the medium after centrifugation with the air system was significantly higher than that with the original system (13.3 +/- 0.2 degrees C vs. 8.7 +/- 0.7 degrees C, p < 0.05). The original cooler system was found to be more efficient at reducing heat generated by the COBE machine than the air system. Further investigation of the importance of the recorded temperatures is required.

Could islet transplantation be a potential cure for diabetes?

Islet transplantation is a way of replacing the insulin-producing beta cells in patients whose own cells have been destroyed. Sue Swift and Steve White explain what islet transplantation involves and give a realistic summary of what can be expected as the clinical programme gets underway in the UK.