Frequency-dependent drug screening using optogenetic stimulation of human iPSC-derived cardiomyocytes.

Side effects on cardiac ion channels are one major reason for new drugs to fail during preclinical evaluation. Herein we propose a simple optogenetic screening tool measuring extracellular field potentials (FP) from paced cardiomyocytes to identify drug effects over the whole physiological heart range, which is essential given the rate-dependency of ion channel function and drug action. Human induced pluripotent stem cell-derived cardiomyocytes were transduced with an adeno-associated virus to express Channelrhodopsin2 and plated on micro-electrode arrays.

Synchronization of excitable cardiac cultures of different origin.

In the present work, we investigated the synchronization of electrical activity in cultured cardiac cells of different origin put in direct contact. In the first set of experiments synchronization was studied in the primary culture cells of neonatal rats taken at different developmental ages, and in the second - in the neonatal rat cardiomyocytes and HL-1 cells. The electrical excitation of cells was recorded using the calcium transient marker Fluor-4.

Enabling reimbursement to health departments for immunization services.

Through its Billables Project, the Centers for Disease Control and Prevention is helping US health departments to implement programs to bill Medicaid, Medicare, and private insurance for vaccine costs and administration fees for insured clients. A 2001 national survey published in the American Journal of Preventive Medicine found that only 31% of US health departments were billing managed care organizations for the immunization services they provided to insured patients. By developing billing systems, health departments have found a new stream of revenue.

Local gene targeting and cell positioning using magnetic nanoparticles and magnetic tips: comparison of mathematical simulations with experiments.

Purpose: Magnetic nanoparticles (MNPs) and magnets can be used to enhance gene transfer or cell attachment but gene or cell delivery to confined areas has not been addressed. We therefore searched for an optimal method to simulate and perform local gene targeting and cell delivery in vitro.

Methods: Localized gene transfer or cell positioning was achieved using permanent magnets with newly designed soft iron tips and MNP/lentivirus complexes or MNP-loaded cells, respectively.