Effects of Modified Simultaneous Unipolar Saline-Irrigated Radiofrequency Ablation in Patients with Atrial Fibrillation Combined with Mitral Valve Disease.

OBJECTIVE: To investigate the therapeutic effects of a modified simultaneous unipolar saline-irrigated radiofrequency ablation by intracardiac operation under direct vision in patients with mitral valve diseases combined with atrial fibrillation (AF). METHODS: A total of 168 patients with mitral valve diseases combined with AF who underwent unipolar saline-irrigated radiofrequency ablation modified maze procedures were enrolled and divided into the mitral stenosis (MS) group (n = 87) and the mitral insufficiency (MI) group (n = 81). RESULTS: Those with a left atrium diameter (LAD) < 55 mm had a better cardioversion effect during the mid-term post-operation than those with a LAD ≥ 55 mm (P < 0.05). The cardioversion effect during the mid-term post-operation was better in those with a duration of AF < 2 years than those with AF ≥ 2 years (P < 0.05). The LAD reduced significantly during the early postoperative period in the MS group (P < 0.05). Compared with the early postoperative period, LAD further reduced, and the EF increased significantly during the mid-term post-operation (P<0.05). The LAD reduced significantly during the early postoperative period in the MI group (P < 0.05), together with relatively decreased EF (P < 0.05). Compared with the early postoperative period, LAD further reduced, and the EF increased significantly during the mid-term post-operation (P<0.05). The improvement of LAD in the MI group during the mid-term post-operation was better than that in the MS group (P < 0.05). CONCLUSION: The cardioversion effects and the improvement in cardiac function during the mid-term post-operation were good in the radiofrequency ablation by intracardiac operation under direct vision in patients with different mitral valve diseases combined with AF. The cardioversion effects during the early postoperative period and the mid-term post-operation were better in patients with MI than in those with MS.

The predictive value of procalcitonin in ventilator-associated pneumonia after cardiac valve replacement.

This study aimed to evaluate the predictive value of procalcitonin (PCT) in ventilator-associated pneumonia (VAP) after cardiac valve replacement. A total of 80 patients who underwent cardiac valve replacement in our department were enrolled in this study. Of these patients,40 were diagnosed with VAP and assigned to the observation group, while the other 40 patients not diagnosed with VAP were assigned to the control group. The changes in serum PCT, white blood cell count and C-reactive protein (CRP) were observed before each operation (T0), on the first day after the operation (T1), the second day after the operation (T2) and the third day after the operation (T3). After the operation, the serum PCT in the observation group was significantly higher than those at different time points after the operation, and also significantly higher than those in the control group (p < .05). In the control group, PCT was significantly higher after the operation than before the operation (p < .05), but the differences among the different postoperative time points were not statistically significant (p > .05). In the two groups, the white blood cell count and CRP were significantly higher after the operation than before the operation (p < .05), but the differences between the two groups were not statistically significant (p > .05). Serum PCT is an early, sensitive and highly specific high-risk monitoring index and has an early prediction value for VAP after cardiac valve replacement.

The Application of Transesophageal Echocardiography in Mitral Valve Repair With Tendon Reconstruction.

Objective: To investigate whether tendon reconstruction during mitral valve repair can be effectively guided by transesophageal echocardiography (TEE), using the mid-esophageal bi-commissure view, bicaval view and the aortic valve-mitral valve transition short-axis view. Methods: A total of 40 patients that underwent mitral valve repair with artificial tendineae were recruited. Before the operation, conventional transthoracic echocardiography was used to determine whether mitral valve repair would be possible. Following intraoperative anesthesia, two-dimensional and three-dimensional TEE reconstructions were used to assess the state of the valve and tendon and to make a repair plan. Results: TEE accurately diagnosed single functional tendon rupture and predicted single artificial tendon implantation in 88% of cases (23/26). TEE accurately diagnosed single functional tendon rupture and predicted the implantation of two artificial tendons in 100% of cases (4/4). TEE accurately diagnosed two or more functional tendon ruptures and predicted the implantation of two artificial tendons in 100% of cases (5/5). The length of the tendon cord predicted by TEE (2.45 ± 0.15 mm) was not significantly different (P > 0.05) from the length of the cord that was actually implanted (2.31 ± 0.11 mm). TEE also accurately predicted the size of the annuloplasty ring in 86% of cases (33/38), with differences of 2 mm or less compared to the size of the ring that was actually implanted. Conclusion: Both the mid-esophageal bi-commissure view, bicaval view and the short-axis view of the aortic valve-mitral valve transition can reduce the difficulty of tendon reconstruction by helping to determine what length of tendon and what size of artificial annulus are required.

Visible-Light-Promoted Tandem Difluoroalkylation-Amidation: Access to Difluorooxindoles from Free Anilines.

An efficient and synthetically convenient method for the synthesis of 3,3-difluoro-2-oxindole through a visible-light-induced photoredox difluoromethylation-amidation is described. The process can generate a broad range of difluorooxindoles using bromodifluoroacetate and broadly available free anilines. The wide range of substrate tolerance and mild reaction conditions make this transformation a highly valuable method in applications for drug discovery and development.

Tandem Difluoroalkylation-Arylation of Enamides Catalyzed by Nickel.

A nickel-catalyzed three-component reaction for the synthesis of difluoroalkylated compounds through tandem difluoroalkylation-arylation of enamides has been developed. The reaction tolerates a variety of arylboronic acids and widely available difluoroalkyl bromides, and even the relatively inert substrate chlorodifluoroacetate. The significant advantages of this protocol are the low-cost nickel catalyst, synthetic convenience, excellent functional-group compatibility and high reaction efficiency.

Palladium-Catalyzed Difluoroalkylation of Isocyanides: Access to Difluoroalkylated Phenanthridine Derivatives.

An efficient and general method for the synthesis of difluoroalkylated phenanthridine derivatives through palladium-catalyzed reaction of difluoroalkyl bromides with isocyanides is described. The reaction can also be extended to perfluoroalkyl iodides. Mechanistic studies reveal that a difluoroalkyl radical via a single-electron-transfer pathway is involved in the reaction.

Rhodium-Catalyzed ortho-Selective C-F Bond Borylation of Polyfluoroarenes with Bpin-Bpin.

An ortho-selective C-F bond borylation between N-heterocycle-substituted polyfluoroarenes and Bpin-Bpin with simple and commercially available [Rh(cod)2 ]BF4 as a catalyst is now reported. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, even toward monofluoroarene, thus providing a facile access to a wide range of borylated fluoroarenes that are useful for photoelectronic materials. Preliminary mechanistic studies reveal that a Rh(III/V) catalytic cycle via a key intermediate rhodium(III) hydride complex [(H)Rh(III) Ln (Bpin)] may be involved in the reaction.

Synthesis of Tat tagged and folate modified N-succinyl-chitosan self-assembly nanoparticles as a novel gene vector.

The purpose of this research was to prepare a novel type of Tat tagged and folate modified N-succinyl-chitosan (Tat-Suc-FA) self-assembly nanoparticles, to provide a new vector for tumor gene therapy. In this study, Tat-Suc-FA polymers was synthesized and characterized using (1)H NMR and FT-IR. The copolymer had a mean diameter of 65 ± 22.6 nm, a zeta potential of 40 ± 0.2 mV. The cytotoxicity assay showed that Tat-Suc-FA polymers were less toxic than chitosan in the tested concentration range (from 2 to 500 µg/ml). Tat-Suc-FA/DNA complexes at various weight ratios were formulated and characterized. Particle sizes of Tat-Suc-FA/DNA complexes were between 54 and 106 nm as determined by dynamic light scattering. Accordingly, Transmission electron microscope photo of Tat-Suc-FA/DNA complexes exhibited a spherical and compact morphology. Zeta potentials of these complexes changed as the weight ratio varied (from 3 to 44 mV). Agarose gel electrophoresis assay showed that Tat-Suc-FA could efficiently condense the DNA, when the weight ratio was above 1.5/1. Together, these results suggest that the low toxic Tat-Suc-FA cationic polymers could be considered for use as a novel type of gene delivery vectors.

A general synthesis of fluoroalkylated alkenes by palladium-catalyzed Heck-type reaction of fluoroalkyl bromides.

An efficient palladium-catalyzed Heck-type reaction of fluoroalkyl halides, including perfluoroalkyl bromides, trifluoromethyl iodides, and difluoroalkyl bromides, has been developed. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, and provides a general and straightforward access to fluoroalkylated alkenes which are of interest in life and material sciences.