Ca2+ oscillations, Ca2+ sensitization, and contraction activated by protein kinase C in small airway smooth muscle.

Protein kinase C (PKC) has been implicated in the regulation of smooth muscle cell (SMC) contraction and may contribute to airway hyperresponsiveness. Here, we combined optical and biochemical analyses of mouse lung slices to determine the effects of PKC activation on Ca(2+) signaling, Ca(2+) sensitivity, protein phosphorylation, and contraction in SMCs of small intrapulmonary airways. We found that 10 µM phorbol-12-myristate-13-acetate or 1 µM phorbol 12,13-dibutyrate induced repetitive, unsynchronized, and transient contractions of the SMCs lining the airway lumen.

Chloride channel blockers promote relaxation of TEA-induced contraction in airway smooth muscle.

Enhanced airway smooth muscle (ASM) contraction is an important component in the pathophysiology of asthma. We have shown that ligand gated chloride channels modulate ASM contractile tone during the maintenance phase of an induced contraction, however the role of chloride flux in depolarization-induced contraction remains incompletely understood. To better understand the role of chloride flux under these conditions, muscle force (human ASM, guinea pig ASM), peripheral small airway luminal area (rat ASM) and airway smooth muscle plasma membrane electrical potentials (human cultured ASM) were measured.

Tumor necrosis factor-α (TNF-α) augments AMPA-induced Purkinje neuron toxicity.

It is well recognized that exposure of neurons to excessive levels of the excitatory neurotransmitter glutamate, termed glutamate excitotoxicity, contributes to the damage and degeneration seen in many acute and chronic neurological diseases. However, it is becoming increasingly evident that inflammation also can play a role in certain neurodegenerative diseases and inflammatory mediators, such as tumor necrosis factor-α (TNF-α), may directly interact with excitotoxic processes. In a postnatal rat cerebellar slice model, we found that TNF-α exacerbated AMPA-induced excitotoxicity in Purkinje neurons in a dose-dependent manner beyond the toxicity caused by AMPA alone.

Novel self-organization mechanism in ultrathin liquid films: theory and experiment.

When an ultrathin metal film of thickness h (<20 nm) is melted by a nanosecond pulsed laser, the film temperature is a nonmonotonic function of h and achieves its maximum at a certain thickness h*. This is a consequence of the h and time dependence of energy absorption and heat flow. Linear stability analysis and nonlinear dynamical simulations that incorporate such intrinsic interfacial thermal gradients predict a characteristic pattern length scale Lambda that decreases for h>h*, in contrast to the classical spinodal dewetting behavior where Lambda increases monotonically as h2.