Electrical signalling in prokaryotes and its convergence with quorum sensing in Bacillus

The importance of electrical signalling in bacteria is an emerging paradigm. Bacillus subtilis biofilms exhibit electrical communication that regulates metabolic activity and biofilm growth. Starving cells initiate oscillatory extracellular potassium signals that help even the distribution of nutrients within the biofilm and thus help regulate biofilm development. Quorum sensing also regulates biofilm growth and crucially there is convergence between electrical and quorum sensing signalling axes. This makes B. subtilis an interesting model for cell signalling research. SpoOF is predicted to act as a logic gate for signalling pathway convergence, raising interesting questions about the functional nature of this gate and the relative importance of these disparate signals on biofilm behaviour. How is an oscillating signal integrated with a quorum signal? The model presented offers rich opportunities for future experimental and theoretical modelling research. The importance of direct cell-to-cell electrical signalling in prokaryotes, so characteristic of multicellular eukaryotes, is also discussed

Study design and methods of the BoTULS trial: a randomised controlled trial to evaluate the clinical effect and cost effectiveness of treating upper limb spasticity due to stroke with botulinum toxin type A

Background Following a stroke, 55–75% of patients experience upper limb problems in the longer term. Upper limb spasticity may cause pain, deformity and reduced function, affecting mood and independence. Botulinum toxin is used increasingly to treat focal spasticity, but its impact on upper limb function after stroke is unclear. The aim of this study is to evaluate the clinical and cost effectiveness of botulinum toxin type A plus an upper limb therapy programme in the treatment of post stroke upper limb spasticity. Methods Trial design : A multi-centre open label parallel group randomised controlled trial and economic evaluation. Participants : Adults with upper limb spasticity at the shoulder, elbow, wrist or hand and reduced upper limb function due to stroke more than 1 month previously. Interventions : Botulinum toxin type A plus upper limb therapy (intervention group) or upper limb therapy alone (control group). Outcomes : Outcome assessments are undertaken at 1, 3 and 12 months. The primary outcome is upper limb function one month after study entry measured by the Action Research Arm Test (ARAT). Secondary outcomes include: spasticity (Modified Ashworth Scale); grip strength; dexterity (Nine Hole Peg Test); disability (Barthel Activities of Daily Living Index); quality of life (Stroke Impact Scale, Euroqol EQ-5D) and attainment of patient-selected goals (Canadian Occupational Performance Measure). Health and social services resource use, adverse events, use of other antispasticity treatments and patient views on the treatment will be compared. Participants are clinically reassessed at 3, 6 and 9 months to determine the need for repeat botulinum toxin type A and/or therapy. Randomisation : A web based central independent randomisation service. Blinding : Outcome assessments are undertaken by an assessor who is blinded to the randomisation group. Sample size : 332 participants provide 80% power to detect a 15% difference in treatment successes between intervention and control groups. Treatment success is defined as improvement of 3 points for those with a baseline ARAT of 0–3 and 6 points for those with ARAT of 4–56

The 48 odor descriptors used to characterize the samples in this study.

<p>The 48 odor descriptors used to characterize the samples in this study.</p