An opto-structural method to estimate the stress-strain field induced by cell contraction on substrates of controlled stiffness in vitro.

Purpose: Mechanical properties of the extra-cellular matrix (ECM) such as stiffness mediate cell signaling, proliferation, migration, and differentiation. Within this context, we developed a method to estimate in vitro the stress-strain field induced by contraction of cardiovascular progenitor cells on substrates of controlled stiffness.

Methods: Two alginate-agarose hydrogels were polymerized and mechanically characterized under compression.

Intravenous alfacalcidol once weekly suppresses parathyroid hormone in hemodialysis patients.

Management of secondary hyperparathyroidism is difficult because of the interrelationship of parathyroid hormone, calcium and phosphorus. This study was carried out to assess the efficacy of intravenous administration of alfacalcidol once weekly versus twice weekly in patients with severe hyperparathyroidism. Twenty-one hemodialysis patients with intact parathyroid hormone >88 pmol/L were divided into two groups.