Applicability of body surface potential map in computerized optimization of biventricular pacing.

Biventricular pacing (BVP) could be improved by identifying the patient-specific optimal electrode positions. Body surface potential map (BSPM) is a non-invasive technique for obtaining the electrophysiology and pathology of a patient. The study proposes the use of BSPM as input for an automated non-invasive strategy based on a personalized computer model of the heart, to identify the patient pathology and specific optimal treatment with BVP devices.

Substrate-bound protein gradients for cell culture fabricated by microfluidic networks and microcontact printing.

Graded distributions of proteins are pivotal for many signaling processes during development, such as morphogenesis, cell migration, and axon guidance. Here, we describe a technique to fabricate substrate-bound stepwise protein gradients by means of a microfluidic network etched into a silicon wafer with an array of parallel 14-micrometer-wide channels, which can be filled with a series of arbitrarily chosen protein solutions. In a subsequent microcontact printing step, the protein pattern is transferred onto a surface and is used as a substrate for cell culture.

Wnt-5A/Ror2 regulate expression of XPAPC through an alternative noncanonical signaling pathway.

XWnt-5A, a member of the nontransforming Wnt-5A class of Wnt ligands, is required for convergent extension movements in Xenopus embryos. XWnt-5A knockdown phenocopies paraxial protocadherin (XPAPC) loss of function: involuted mesodermal cells fail to align mediolaterally, which results in aberrant movements and a selective inhibition of constriction. XWnt-5A depletion was rescued by coinjection of XPAPC RNA, indicating that XWnt-5A acts upstream of XPAPC.

Multiple wavelets, rotors, and snakes in atrial fibrillation--a computer simulation study.

Background: Multiple wavelets and rotors are accused of maintaining atrial fibrillation (AF). However, snake-like excitation patterns have recently been observed in AF. So far, computer models have investigated AF in a simplified anatomical model.