Elucidating the Electronic Structure of High-Spin [Mn(TPP)Cl] Using Magnetic Circular Dichroism Spectroscopy.

Manganese porphyrins are used as catalysts in the oxidation of olefins and nonactivated hydrocarbons. Key to these reactions are high-valent Mn-(di)oxo species, for which [Mn(Porph)(X)] serve as precursors. To elucidate their properties, it is crucial to understand the interaction of the Mn center with the porphyrin ligand.

Effects of protein structure on iron-polypeptide vibrational dynamic coupling in cytochrome c.

Cytochrome c (Cyt c) has a heme covalently bound to the polypeptide via a Cys-X-X-Cys-His (CXXCH) linker that is located in the interface region for protein-protein interactions. To determine whether the polypeptide matrix influences iron vibrational dynamics, nuclear resonance vibrational spectroscopy (NRVS) measurements were performed on (57)Fe-labeled ferric Hydrogenobacter thermophilus cytochrome c-552, and variants M13V, M13V/K22M, and A7F, which have structural modifications that alter the composition or environment of the CXXCH pentapeptide loop. Simulations of the NRVS data indicate that the 150-325 cm(-1) region is dominated by NHis-Fe-SMet axial ligand and polypeptide motions, while the 325-400 cm(-1) region shows dominant contributions from ν(Fe-NPyr) (Pyr = pyrrole) and other heme-based modes.

Beta-catenin nuclear labeling is a common feature of sessile serrated adenomas and correlates with early neoplastic progression after BRAF activation.

Recent observations indicate that some sessile serrated adenomas (SSAs) have aberrant beta-catenin nuclear labeling, implicating the Wnt pathway in the molecular progression of SSAs to colorectal carcinoma. We sought to expand upon this finding by characterizing beta-catenin expression in the full spectrum of serrated colorectal polyps, and correlating these findings with the genetic status of BRAF, KRAS and CTNNB1. Immunolabeling for beta-catenin confirmed the presence of abnormal nuclear accumulation in SSAs, with 35/54 (67%) SSAs showing nuclear labeling compared with 0/12 hyperplastic polyps.

Clinical assessment of sildenafil in the treatment of neurogenic male sexual dysfunction: After the hype.

Objective: To evaluate the efficacy and safety of sildenafil over a two-year period in patients with erectile dysfunction caused by spinal cord injury and multiple sclerosis in a clinical practice following FDA approval and release of the medication to the general healthcare community. Study design: 40 patients including 33 SCI (13 quadriplegics, 20 paraplegics; 14 complete, 19 incomplete) and 7 MS patients were prescribed sildenafil in varying dosages. The patients were asked to return to the clinic for additional prescriptions so that we could assess their clinical response and their incidence of side effects.