Model for bidirectional movement of cytoplasmic dynein.

Cytoplasmic dynein exhibits a directional processive movement on microtubule filaments and is known to move in steps of varying length based on the number of ATP molecules bound to it and the load that it carries. It is experimentally observed that dynein takes occasional backward steps and the frequency of such backward steps increases as the load approaches the stall force. Using a stochastic process model, we investigate the bidirectional movement of single head of a dynein motor. The probability for backward step is implemented based on fluctuation theorem of non-equilibrium statistical mechanics. We find that the movement of dynein motor is characterized with negative velocity implying backward motion beyond stall force. We observe that the motor moves backward for super stall forces by hydrolyzing the ATP exactly the same way as it does while moving forward for sub-stall forces. Movement of dynein is also simulated using a kinetic Monte Carlo method and the simulated velocities are in good agreement with velocities obtained using a stochastic rate equation model.

Amrita Bindu--an antioxidant inducer therapy in asthma children.

Studies all over the world on the therapeutic use of antioxidants as supplements has revealed their capacity to control inflammatory processes. Amrita Bindu an Ayurvedic health food supplement has already shown to be an antioxidant inducer and to combat free radical-mediated tissue damage studied in rats. Amrita Bindu is a salt-spice herbal mixture designed for positive health. It was tested as a supplement to therapy for a period of 12 months in 36 children suffering from asthma. Asthma is a chronic inflammatory disease with excessive free radical generation in lungs and blood cells. The patients were followed up by monitoring their clinical conditions, therapeutic doses of anti-asthmatic drugs, free radical generation, lipid peroxidation (LPO) and antioxidants in blood. At the end of 3 months of Amrita Bindu supplementation, the patients had stopped all anti-asthmatic medications and were free from attacks of asthma.