Surface Chemistry, Microstructure, and Tribological Properties of Cubic Boron Nitride Films

This report deals with the surface chemistry, microstructure, bonding state, morphology, and friction and wear properties of cubic boron nitride (c-BN) films that were synthesized by magnetically enhanced plasma ion plating. Several analytical techniques - x-ray photoelectron spectroscopy, transmission electron microscopy and electron diffraction, Fourier transform infrared spectroscopy, atomic force microscopy, and surface profilometry - were used to characterize the films. Sliding friction experiments using a ball-on-disk configuration were conducted for the c-BN films in sliding contact with 440C stainless-steel balls at room temperature in ultrahigh vacuum (pressure, 10(exp -6), in ambient air, and under water lubrication. Results indicate that the boron-to-nitrogen ratio on the surface of the as-deposited c-BN film is greater than 1 and that not all the boron is present as boron nitride but a small percentage is present as an oxide. Both in air and under water lubrication, the c-BN film in sliding contact with steel showed a low wear rate, whereas a high wear rate was observed in vacuum. In air and under water lubrication, c-BN exhibited wear resistance superior to that of amorphous boron nitride, titanium nitride, and titanium carbide

Potent Vasodilatory Effect of Fasudil on Radial Artery Graft in Coronary Artery Bypass Operations

Background: The radial artery (RA) is a useful conduit for coronary artery bypass grafting (CABG) but is susceptible to vasospasm during harvesting. We evaluated the usefulness of fasudil, a Rho kinase inhibitor, in dilating the RA graft and increasing graft free flow (GFF) compared with the conventional graft-dilating agents papaverine and verapamil-nitroglycerin (VG). Methods: Between June 2012 and January 2013, 45 patients with ischemic heart disease who underwent isolated CABG using the RA were enrolled and randomly assigned to fasudil (n = 15), papaverine (n = 15), or VG (n = 15). Fasudil (2.67 mmol/L), papaverine (1.0 mmol/L) mixed with heparinized blood, or VG (30 μmol/L each of verapamil and nitroglycerin) was injected intraluminally into the RA graft after harvesting. Main outcome measures were RA GFF, hemodynamic changes, and histopathologic examination of the RA. Results: In the fasudil group, GFF increased significantly (p < 0.001) from 36.8 ± 20.4 at baseline to 148.0 ± 88.3 mL/min after injection. GFF increased significantly (p < 0.001) from 36.0 ± 19.0 to 72.3 ± 36.7 mL/min in the papaverine group and increased significantly (p < 0.001) from 39.5 ± 23.3 to 64.3 ± 29.9 mL/min in the VG group. The GFF was significantly higher (p = 0.001) in fasudil-treated RA than in papaverine- or VG-treated RA. Histopathologically, RA graft diameter was markedly increased after fasudil injection, and the structure of the multiple elastic lamellae was intact. Blood pressure did not change significantly after drug injection in all groups. Conclusions: Fasudil exhibited a very potent vasodilatory effect on the RA compared with conventional papaverine or VG, resulting in increased GFF. This agent is useful for dilating RA grafts in CABG. © 2013 The Society of Thoracic Surgeons

Fasudil is a superior vasodilator for the internal thoracic artery in coronary surgery

Background: The internal thoracic artery (ITA) is a very useful conduit for coronary artery bypass artery (CABG), with excellent long-term patency. With the purpose to dilate the ITA graft and increase graft free flow (GFF) intraoperatively, we evaluated the usefulness of intraluminal injection of fasudil, a Rho-kinase inhibitor, in comparison to the conventional graft dilating agent, papaverine. Methods: Between June 2011 and January 2012, 30 patients with ischemic heart disease who underwent isolated CABG using ITA were enrolled. The patients were randomly assigned to 2 groups: the fasudil group (n = 15) in which fasudil solution 0.9 mg/dL was injected into the ITA, and the papaverine group (n = 15) in which papaverine solution (0.4 mg/mL) mixed with heparinized blood was used. Outcome measures were left ITA GFF, heart rate, and mean blood pressure during flow measurements, and histopathologic examination of the ITA. Results: In the fasudil group, GFF increased significantly (p < 0.01) from 19.7 ± 15.2 mL/minute at baseline to 66.9 ± 31.7 mL/minute after fasudil injection. In the papaverine group, GFF increased significantly (p < 0.01) from 22.9 ± 17.3 mL/minute at baseline to 44.8 ± 26.7 mL/minute after papaverine injection. Blood pressure and heart rate did not change significantly after drug injection in both groups. The GFF was significantly higher (p = 0.038) in fasudil-treated ITA than in papaverine-treated ITA. Histopathologically, the diameter of the ITA was markedly increased after fasudil injection. Elastica van Gieson staining showed that the multiple elastic lamellae structure was intact. Conclusions: Fasudil exhibited very potent vasodilatory effect on the ITA compared with conventional papaverine resulting in increased GFF. This agent is a useful graft dilating agent. © 2013 The Society of Thoracic Surgeons

Biologia e genetica del podocita

Progresses in podocyte biology have been strictly connected with genetic advances; the identification of genes mutated in familial and sporadic forms of nephrotic syndrome has been followed by functional studies of the encoded proteins, revealing numerous properties of the cell. The molecules uncovered so far belong to three main categories: a) proteins located at the slit diaphragm, the intercellular junction which laterally connects podocyte processes and is responsible for selectivity of the glomerular filter, b) molecules involved in regulation of actin dynamics, which are essential for the maintenance of podocyte structure and function, and c) molecules belonging to intracellular organelles, such as mitochondria and lysosomes, which are central players in podocyte metabolism. Considering the key role of the podocyte in health and disease of the glomerular filter, better knowledge of this cell is a pre-requisite for developing targeted therapies of glomerular diseases

Podocytes: recent biomolecular developments.

AbstractPodocytes are postmitotic renal glomerular cells with multiple ramifications that extend from the cell body. Processes departing from a podocyte interdigitate with corresponding projections from neighboring cells and form an intricate web that enwraps the glomerular capillary completely. Podocyte processes are interconnected by the slit diaphragm, an adhesion junction mostly formed by Ig-like molecules, cadherins/protocadherins, ephrin/eph, and neurexin molecules organized in an assembly that resembles synaptic junctions. Podocyte failure is primarily or secondarily implicated in all forms of proteinuric glomerular diseases, as confirmed by the morphological changes of their elaborate cell architecture detectable by electron microscopy. Importantly, mutations of podocyte proteins are responsible for the most severe forms of congenital nephrotic syndrome. In the last 15 years, progressive technological advances have aided the study of podocyte biology and pathology, confirming the relevance of podocyte molecules and signaling pathways for the function of the glomerular filter. This review will examine the most important and newest discoveries in the field, which is rapidly evolving, hopefully leading to a detailed knowledge of this fascinating cell and to the development of specific therapeutic options for proteinuric diseases