Photolysis quantum yield measurements in the near-UV; a critical analysis of 1-(2-nitrophenyl)ethyl photochemistry.

The photolysis quantum yield, Qp, of 1-(2-nitrophenyl)ethyl phosphate (caged Pi) measured in the near-UV (342 nm peak with 60 nm half-bandwidth) is 0.53 and is based on results reported in 1978 (Biochemistry, 17, 1929-1935). This article amplifies methodology for determining that Qp in view of different recent estimates.

Agonist-induced Ca2+ sensitization in smooth muscle: redundancy of Rho guanine nucleotide exchange factors (RhoGEFs) and response kinetics, a caged compound study.

Many agonists, acting through G-protein-coupled receptors and Gα subunits of the heterotrimeric G-proteins, induce contraction of smooth muscle through an increase of [Ca(2+)]i as well as activation of the RhoA/RhoA-activated kinase pathway that amplifies the contractile force, a phenomenon known as Ca(2+) sensitization. Gα12/13 subunits are known to activate the regulator of G-protein signaling-like family of guanine nucleotide exchange factors (RhoGEFs), which includes PDZ-RhoGEF (PRG) and leukemia-associated RhoGEF (LARG). However, their contributions to Ca(2+)-sensitized force are not well understood.

Orientation of the N-terminal lobe of the myosin regulatory light chain in skeletal muscle fibers.

The orientation of the N-terminal lobe of the myosin regulatory light chain (RLC) in demembranated fibers of rabbit psoas muscle was determined by polarized fluorescence. The native RLC was replaced by a smooth muscle RLC with a bifunctional rhodamine probe attached to its A, B, C, or D helix. Fiber fluorescence data were interpreted using the crystal structure of the head domain of chicken skeletal myosin in the nucleotide-free state.

Pulmonary manifestations of relapsing polychondritis.

Relapsing polychondritis (RP) is a chronic multisystemic disease characterized by recurrent episodes of cartilage inflammation throughout the body. The lower respiratory tract is involved in 20% to 50% of patients and results in significant morbidity. Effective medical therapies and airway interventions are available in experienced centers; however, no single treatment is curative, and the prognosis of RP with airway disease remains overall guarded.