Combined Mitral and Tricuspid Versus Isolated Mitral Valve Transcatheter Edge-to-Edge Repair in Patients With Symptomatic Valve Regurgitation at High Surgical Risk

Objectives

The present study aimed to test the clinical benefit of combined transcatheter mitral plus tricuspid valve edge-to-edge repair (TMTVR) as compared with transcatheter mitral valve edge-to-edge repair (TMVR) alone in patients with both significant mitral (MR) and tricuspid regurgitation (TR) at high surgical risk.

In vitro core particle and nucleosome assembly at physiological ionic strength.

Nucleosome core particles have been efficiently assembled in vitro by direct interaction of histones and DNA at physiological ionic strength, as assayed by digestion with DNases, supercoiling of relaxed circular DNA, and electron microscopy. Reconstitution was achieved either by the simultaneous addition of all core histones, or by the sequential binding of H3 . H4 tetramer and H2A . H2B dimer to DNA. Micrococcal nuclease digestion and electron microscopy studies indicated that there is heterogeneity in the spacings at which core particles are assembly on the DNA. Length measurements of oligomeric DNA produced during the course of the digestion suggest that the core histone octamer can organize 167 (+/- 4) rather than 145 base pairs of DNA, the extra 20 base pairs being quickly digested. Binding of histone H1 to core particles resulted in the protection of about 165 base pairs of DNA from nuclease attack. Because the core histone octamer is fully dissociated into H3 . H4 tetramer and H2A . H2B dimer at physiological ionic strength, our results would suggest that in vivo core particle assembly may also occur by interaction of these two complexes on the nascent DNA.     

Characterization of a Shiga Toxin-Encoding Temperate Bacteriophage of Shigella sonnei

A Shiga toxin (Stx)-encoding temperate bacteriophage of Shigella sonnei strain CB7888 was investigated for its morphology, DNA similarity, host range, and lysogenization in Shigella and Escherichia coli strains. Phage 7888 formed plaques on a broad spectrum of Shigella strains belonging to different species and serotypes, including Stx-producing Shigella dysenteriae type 1. With E. coli, only strains with rough lipopolysaccharide were sensitive to this phage. The phage integrated into the genome of nontoxigenic S. sonnei and laboratory E. coli K-12 strains, which became Stx positive upon lysogenization. Moreover, phage 7888 is capable of transducing chromosomal genes in E. coli K-12. The relationships of phage 7888 with the E. coli Stx1-producing phage H-19B and the E. coli Stx2-producing phage 933W were investigated by DNA cross-hybridization of phage genomes and by nucleotide sequencing of an 8,053-bp DNA region of the phage 7888 genome flanking the stx genes. By these methods, a high similarity was found between phages 7888 and 933W. Much less similarity was found between phages H-19B and 7888. As in the other Stx phages, a regulatory region involved in Q-dependent expression is found upstream of stxA and stxB (stx gene) in phage 7888. The morphology of phage 7888 was similar to that of phage 933W, which shows a hexagonal head and a short tail. Our findings demonstrate that stx genes are naturally transferable and are expressed in strains of S. sonnei, which points to the continuous evolution of human-pathogenic Shigella by horizontal gene transfer.     

Monitoring with two-dimensional transesophageal echocardiography: Comparison of myocardial function in patients undergoing supraceliac,suprarenal-infraceliac,or infrarenal aortic occlusion

When the aorta must be temporarily occluded at the suprarenal or supraceliac levels during surgery, the resulting large increase in afterload may make the myocardium ischemic, even though systemic and pulmonary artery pressures and cardiac output are maintained at normal levels. These traditional indices of myocardial well-being do not appear to be sufficiently sensitive, since cardiac complications are still the most frequent cause of perioperative death and morbidity after aortic reconstruction. To evaluate two-dimensional transesophageal echocardiography as a monitor of myocardial well-being, we studied 24 American Society of Anesthesiologists physical status class III or IV adult patients who were undergoing aortic reconstruction and occlusion at the supraceliac (n = 12), suprarenal-infraceliac (n = 6), or infrarenal (n = 6) level. In addition to traditional monitors, we used a gastroscope tipped with a special 3.5 MHz two-dimensional echocardiographic transducer (Diasonics) that was placed in the esophagus to give a cross-sectional view of the left ventricle through the base of the papillary muscles. The hemodynamic effects of clamping the aorta were managed by administration of vasodilating drugs, anesthetics, and fluids to keep systemic and pulmonary arterial pressures normal. Occlusion at the supraceliac level caused major increases in left ventricular end-systolic and end-diastolic areas, decreases in ejection fraction, and frequent wall motion abnormalities; these changes were not detected by conventional monitoring devices. Occlusion at the suprarenal-infraceliac level caused similar but smaller changes, and occlusion at the infrarenal level caused only minimal cardiovascular effects. We conclude that the two-dimensional transesophageal echocardiogram offers promise as an intraoperative monitoring device. (J VASC SURG 1984;1:300-305.)     

Modell einer Sondersprechstunde für Patienten mit atopischem Ekzem

Due to its high prevalence, atopic dermatitis is an important problem in the dermatologic practice. The chronicity of the disease together with numerous triggering factors of varying individual impact create a complex situation which is difficult to manage under the current circumstances in our health care system. We describe the concept of an outpatient clinic especially for atopic dermatitis as established in our Department of Dermatology. A high degree of standardization is combined with a high measure of individual care. The aims of this clinic are an optimized outpatient management of atopic dermatitis, the gathering of epidemiologic data, the performance of controlled studies, and potentially the reduction of costs.     

Percutaneous pulmonary and tricuspid valve implantations: An update

The field of percutaneous valvular interventions is one of the most exciting and rapidly developing within interventional cardiology. Percutaneous procedures focusing on aortic and mitral valve replacement or interventional treatment as well as techniques of percutaneous pulmonary valve implantation have already reached worldwide clinical acceptance and routine interventional procedure status. Although techniques of percutaneous pulmonary valve implantation have been described just a decade ago, two stent-mounted complementary devices were successfully introduced and more than 3000 of these procedures have been performed worldwide. In contrast, percutaneous treatment of tricuspid valve dysfunction is still evolving on a much earlier level and has so far not reached routine interventional procedure status. Taking into account that an “interdisciplinary challenging”, heterogeneous population of patients previously treated by corrective, semi-corrective or palliative surgical procedures is growing inexorably, there is a rapidly increasing need of treatment options besides redo-surgery. Therefore, the review intends to reflect on clinical expansion of percutaneous pulmonary and tricuspid valve procedures, to update on current devices, to discuss indications and patient selection criteria, to report on clinical results and finally to consider future directions.     

Renal sympathetic denervation in therapy resistant hypertension - pathophysiological aspects and predictors for treatment success

Many forms of human hypertension are associated with an increased systemic sympathetic activity. Especially the renal sympathetic nervous system has been found to play a prominent role in this context. Therefore, catheter-interventional renal sympathetic denervation (RDN) has been established as a treatment for patients suffering from therapy resistant hypertension in the past decade. The initial enthusiasm for this treatment was markedly dampened by the results of the Symplicity-HTN-3 trial, although the transferability of the results into clinical practice to date appears to be questionable. In contrast to the extensive use of RDN in treating hypertensive patients within or without clinical trial settings over the past years, its effects on the complex pathophysiological mechanisms underlying therapy resistant hypertension are only partly understood and are part of ongoing research. Effects of RDN have been described on many levels in human trials: From altered systemic sympathetic activity across cardiac and metabolic alterations down to changes in renal function. Most of these changes could sustainably change long-term morbidity and mortality of the treated patients, even if blood pressure remains unchanged. Furthermore, a number of promising predictors for a successful treatment with RDN have been identified recently and further trials are ongoing. This will certainly help to improve the preselection of potential candidates for RDN and thereby optimize treatment outcomes. This review summarizes important pathophysiologic effects of renal denervation and illustrates the currently known predictors for therapy success.     

Feasibility and reproducibility of biventricular volumetric assessment of cardiac function during exercise using real‐time radial k‐t SENSE magnetic resonance imaging

Purpose

To assess the feasibility and reproducibility of real‐time radial k‐t sensitivity encoding (SENSE) magnetic resonance imaging (MRI) for biventricular volumetric assessment during exercise.

Materials and Methods

In all, 12 healthy young adults underwent MRI at rest and during supine exercise at three different workload intensities. Biventricular volumes and function were assessed with 1) a radial k‐t SENSE real‐time sequence and 2) a scanner vendor supplied (standard) real‐time sequence. Global image quality, motion fidelity, and agreement in right ventricular (RV) and left ventricular (LV) stroke volume (SV) as a surrogate measure for accuracy were assessed. Exercise MR was repeated within 1 month for assessment of reproducibility.

Results

Imaging scores were superior for radial real‐time k‐t SENSE images (P < 0.001). Agreement in RV and LV SV during exercise was better with radial k‐t real‐time (SD of difference ±3.43 vs. ±8.97 mL; P < 0.001). Agreement in cardiac output (CO) in the same subject at two different imaging sessions was better for radial k‐t SENSE. This was significant for the CO calculated for the RV (SD of difference ±0.6 vs. ±0.95 L/min; P = 0.01) and LV (±0.45 vs. ±0.92 L/min; P < 0.001).

Conclusion

Radial k‐t SENSE real‐time imaging represents a feasible and reproducible imaging technique for biventricular assessment during exercise. J. Magn. Reson. Imaging 2009;29:1062–1070. © 2009 Wiley‐Liss, Inc.