Modelling the impact of vaccination on tuberculosis in badgers.

Tuberculosis (TB) in livestock, caused by Mycobacterium bovis, persists in many countries. In Britain, efforts to control TB through the culling of badgers (Meles meles), the principal wildlife host, have so far been unsuccessful, and there is significant interest in vaccination of badgers as an alternative or complementary strategy [corrected]. Using a simulation model, we show that where TB is self-contained within the badger population and there are no external sources of infection, limited-duration vaccination at a high level of efficacy can reduce or even eradicate TB from the badger population. However, where sources of external infection persist, benefits in TB reduction in badgers can only be achieved by ongoing, annual vaccination. Vaccination is likely to be most effective as part of an integrated disease management strategy incorporating a number of different approaches across the entire host community.

Habitat structure mediates biodiversity effects on ecosystem properties.

Much of what we know about the role of biodiversity in mediating ecosystem processes and function stems from manipulative experiments, which have largely been performed in isolated, homogeneous environments that do not incorporate habitat structure or allow natural community dynamics to develop. Here, we use a range of habitat configurations in a model marine benthic system to investigate the effects of species composition, resource heterogeneity and patch connectivity on ecosystem properties at both the patch (bioturbation intensity) and multi-patch (nutrient concentration) scale. We show that allowing fauna to move and preferentially select patches alters local species composition and density distributions, which has negative effects on ecosystem processes (bioturbation intensity) at the patch scale, but overall positive effects on ecosystem functioning (nutrient concentration) at the multi-patch scale. Our findings provide important evidence that community dynamics alter in response to localized resource heterogeneity and that these small-scale variations in habitat structure influence species contributions to ecosystem properties at larger scales. We conclude that habitat complexity forms an important buffer against disturbance and that contemporary estimates of the level of biodiversity required for maintaining future multi-functional systems may need to be revised.

Post-feeding activity of Lucilia sericata (Diptera: Calliphoridae) on common domestic indoor surfaces and its effect on development.

Developmental data of forensically important blowflies used by entomologists to estimate minimum post mortem interval (mPMI) are established under controlled laboratory conditions for various temperature ranges throughout the stages of egg, 1st-3rd instar, puparia, and adult fly emergence. However, environmental conditions may influence the patterns of development and behaviour of blowflies, potentially impacting on these established development rates. Previous studies investigating indoor colonisation have focused on the delay to oviposition, with behaviour during the post-feeding phase in this setting often overlooked. The environment in which third instar larvae disperse when searching for a pupariation site may vary drastically at both outdoor and indoor scenarios, influencing the activity and distance travelled during this phase and possibly affecting developmental rates. This study investigated the effect of eight common domestic indoor surfaces on dispersal time, distance travelled, and behaviour of post-feeding Lucilia sericata as well as any resulting variation in development. It was found that pupariation and puparia length within a pupariation medium of sawdust (often used in laboratory settings) produced comparable results with that of carpeted environments (those deemed to be 'enclosed'). Non-carpeted environments (those which were 'exposed') produced a delay to pupariation likely due to increased activity and energy expenditure in searching for pupariation sites which enabled burial. In addition, the observed speed of travel during dispersal was seen via time lapse photography to be greater within 'exposed' conditions. Larvae which dispersed upon burnt laminate flooring were observed to travel faster than in all other conditions and showed the only significant variation (P=0.04) in the day of emergence in comparison to the control condition of sawdust. This study has demonstrated that wandering phase activity is affected by the environmental surface which has potential implications for estimating both the distance travelled by dispersing larvae in indoor conditions and with further research, may be a consideration in mPMI calculations.

Controlled release levodopa/carbidopa (Sinemet CR4) in Parkinson's disease--an open evaluation of efficacy and safety.

Twenty patients with moderately severe Parkinson's disease entered an open study of the efficacy and safety of a slow release preparation containing levodopa 200 mg and carbidopa 50 mg per tablet ('Sinemet CR4'). Following an initial four week baseline stabilisation period on conventional 'Sinemet' tablets, the patients were transferred to 'Sinemet CR4' and observed at intervals over the next 12 months. Fifteen patients completed the full year observation period. When compared with the baseline period, treatment with 'Sinemet CR4' was associated with longer periods of functional improvement and less fluctuation of response following each dose. The median (range) dose frequency was reduced from three (three-12) to two (two-seven) times daily (p less than 0.001) on 'Sinemet CR4' although median (range) total daily dose of levodopa was increased from 700 (375-2525) to 800 (400-2800) mg without any increase in adverse effects. Three patients developed peripheral neuropathy while receiving Sinemet CR4, but the association with this therapy is unclear. Overall 'Sinemet CR4' allowed a longer dosage interval and provided more stable control of disease manifestations than conventional 'Sinemet'.

Streptokinase morbidity--more common than previously recognised.

Streptokinase is the thrombolytic agent most commonly used for the treatment of acute myocardial infarction. We report eight patients who developed late uncommon adverse reactions to streptokinase probably due to immune complex disease. The clinical manifestations included vasculitic rashes, abnormal renal and liver function tests and a syndrome resembling adult respiratory distress syndrome. Major adverse events with streptokinase such as stroke, bleeding and other allergic reactions, have been previously documented but the morbidity related to delayed reactions has not been widely recognised. These reactions produced significant morbidity resulting in prolonged hospital stay and may need to be considered in the decision to use streptokinase.