Zelluläres Adhäsionsverhalten auf strukturierten und biofunktionalisierten Oberflächen

In der vorliegenden Arbeit wurden zwei Methoden zur Strukturierung von Oberflächen untersucht. Zum einen UV-bestrahlte Polystyrol-Oberflächen, auf die Gelatine adsorbierte, zum anderen das Microcontact Printing von Thiol-SAMs und die anschließende Kopplung verschiedener E-Cadherin-Ektodomänen über ihren SNAP-Tag. Beide Methoden wurden durch Zelladhäsionsassays auf ihre Funktionalität geprüft, u.a. auch auf die Kultivierung und den Erhalt von murinen embryonalen Stammzellen

Cold-inducible RNA binding protein (CIRP), a novel XTcf-3 specific target gene regulates neural development in Xenopus

<p>Abstract</p> <p>Background</p> <p>As nuclear mediators of wnt/β-catenin signaling, Lef/Tcf transcription factors play important roles in development and disease. Although it is well established, that the four vertebrate Lef/Tcfs have unique functional properties, most studies unite Lef-1, Tcf-1, Tcf-3 and Tcf-4 and reduce their function to uniformly transduce wnt/β-catenin signaling for activating wnt target genes. In order to discriminate target genes regulated by XTcf-3 from those regulated by XTcf-4 or Lef/Tcfs in general, we performed a subtractive screen, using neuralized <it>Xenopus </it>animal cap explants.</p> <p>Results</p> <p>We identified cold-inducible RNA binding protein (CIRP) as novel XTcf-3 specific target gene. Furthermore, we show that knockdown of XTcf-3 by injection of an antisense morpholino oligonucleotide results in a general broadening of the anterior neural tissue. Depletion of XCIRP by antisense morpholino oligonucleotide injection leads to a reduced stability of mRNA and an enlargement of the anterior neural plate similar to the depletion of XTcf-3.</p> <p>Conclusion</p> <p>Distinct steps in neural development are differentially regulated by individual Lef/Tcfs. For proper development of the anterior brain XTcf-3 and the Tcf-subtype specific target XCIRP appear indispensable. Thus, regulation of anterior neural development, at least in part, depends on mRNA stabilization by the novel XTcf-3 target gene XCIRP.</p

Permanent pacemaker dependency in patients with new left bundle branch block and new first degree atrioventricular block after transcatheter aortic valve implantation

Conduction disorders with need for permanent pacemaker (PPM) implantation remain frequent complications after transcatheter aortic valve implantation (TAVI). Up to 22% of PPM after TAVI are implanted for new onset left bundle branch block (LBBB) and atrioventricular block (AVB) I. However, clinical benefit and predictors of ventricular pacing in TAVI patients receiving PPM for this indication remain unclear. We retrospectively evaluated pacemaker interrogation data of patients who received a PPM post TAVI for new LBBB and new AVB I. The primary endpoint of this study was relevant ventricular pacing (ventricular pacing rate: Vp ≥ 1%) at the first outpatient pacemaker interrogation. Secondary endpoints were predictors for relevant ventricular pacing. At the first pacemaker interrogation (median follow up at 6.23 2.8-14.8 months), median ventricular pacing frequency was 1.0{\%} 0.1-17.8. Out of 61 patients, 36 (59{\%}) had Vp rates ≥ 1{\%}. Patients with frequent ventricular pacing showed longer QRS duration (155~ms ± 17~ms vs. 144~ms ± 18~ms, p = 0.018) at the time of PPM implantation and were less likely treated with a balloon-expandable Edwards Sapiens Valve (39{\%} vs. 12{\%}, p = 0.040). Our findings suggest that the majority of patients with new LBBB and new AVB I after TAVI show relevant ventricular pacing rates at follow up. Further prospective studies are necessary to identify patients at higher risk of pacemaker dependency

Cross‐presentation of dead‐cell‐associated antigens by DNGR‐1⁺ dendritic cells contributes to chronic allograft rejection in mice

The purpose of this study was to elucidate whether DC NK lectin group receptor-1 (DNGR-1)-dependent cross-presentation of dead-cell-associated antigens occurs after transplantation and contributes to CD8(+)T cell responses, chronic allograft rejection (CAR), and fibrosis. BALB/c or C57BL/6 hearts were heterotopically transplanted into WT, Clec9a(-/-), or Batf3(-/-)recipient C57BL/6 mice. Allografts were analyzed for cell infiltration, CD8(+)T cell activation, fibrogenesis, and CAR using immunohistochemistry, Western blot, qRT(2)-PCR, and flow cytometry. Allografts displayed infiltration by recipient DNGR-1(+)DCs, signs of CAR, and fibrosis. Allografts in Clec9a(-/-)recipients showed reduced CAR (p < 0.0001), fibrosis (P= 0.0137), CD8(+)cell infiltration (P < 0.0001), and effector cytokine levels compared to WT recipients. Batf3-deficiency greatly reduced DNGR-1(+)DC-infiltration, CAR (P < 0.0001), and fibrosis (P= 0.0382). CD8 cells infiltrating allografts of cytochrome C treated recipients, showed reduced production of CD8 effector cytokines (P < 0.05). Further, alloreactive CD8(+)T cell response in indirect pathway IFN-gamma ELISPOT was reduced in Clec9a(-/-)recipient mice (P= 0.0283). Blockade of DNGR-1 by antibody, similar to genetic elimination of the receptor, reduced CAR (P= 0.0003), fibrosis (P= 0.0273), infiltration of CD8(+)cells (p= 0.0006), and effector cytokine levels. DNGR-1-dependent alloantigen cross-presentation by DNGR-1(+)DCs induces alloreactive CD8(+)cells that induce CAR and fibrosis. Antibody against DNGR-1 can block this process and prevent CAR and fibrosis

Two in one is better than one plus one: comparison of adverse events between combining electrophysiological examination and coronary angiography versus performing them consecutively.

In some patients, both an electrophysiological examination (EPS) and a coronary angiography (CA) are necessary. It might be preferable to choose a combined approach of EPS and CA versus performing them consecutively. The purpose of this study is to evaluate the type and rate of adverse events between both approaches.Patients were eligible if they underwent a CA and an EPS in a combined approach or in a time interval of at most 2 months. In all patients, clinical adverse events were recorded.A total of 1184 patients were included. CA and EPS were performed in a combined procedure (comb) in 492 patients, whereas they were performed consecutively in 692 patients (cons). The acute major complication rate was 0.67%, showing no differences between both groups. In the comb 6.9% and in the cons 6.6% of vascular complications were observed (p = 0.20). The rates of AV fistula and hematoma needing transfusion showed a significantly higher rate in the cons group (p = 0.018 and p = 0.045, respectively). In a multivariate logistic regression analysis, age was a significant predictor for groin complications. After propensity matching, AV fistula occurred significantly more often in the cons group (p = 0.002).Overall, serious adverse events were rare and there were no differences between the combined approach of EPS and CA and the consecutive approach; however, the occurrence of AV fistula and groin hematoma needing transfusion occurred significantly less in the combined procedure group. Therefore, a combined approach is preferable to a consecutive one

Recurrence of paroxysmal atrial fibrillation after pulmonary vein isolation: is repeat pulmonary vein isolation enough? A prospective, randomized trial.

In patients with paroxysmal atrial fibrillation (pAF), pulmonary vein isolation (PVI) has become an accepted treatment option with single procedure success rates of 60-80%. A repeat ablation is performed in ~30% of patients because of arrhythmia recurrence. The strategy for this repeat procedure is not defined.Patients with pAF recurrence after PVI were prospectively randomized and underwent a second ablation procedure with either PVI of all reconnected veins or PVI with an additional left atrial anterior line. Follow-up in our arrhythmia clinic was every 3 months up to 12 months including 7 day Holter monitoring. A total of 77 patients (mean age 63 ± 9 years, 69% males) were included in the analysis. A repeat PVI was performed in 41 patients, PVI + anterior line in 36 patients. After a follow-up of 12 months, 26 of 41 (63%) patients after repeat PVI and 18 of 36 (50%) patients with PVI + anterior line were in stable sinus rhythm off antiarrhythmic medication (P = 0.26). In most patients (12 of 15 patients with PVI and 14 of 18 patients with PVI + anterior line) with an arrhythmia recurrence after the second procedure, the recurring arrhythmia was paroxysmal AF. In 2 of 15 patients of the PVI group and in 4 of 18 patients of the PVI + anterior line group atypical flutter was the reoccurring arrhythmia (P = NS).In this prospective randomized trial, patients with a recurrence of paroxysmal AF had no better outcome after repeat PVI + one left atrial line compared with patients with repeat PVI only

A prospective randomized study comparing isolation of the arrhythmogenic vein versus all veins in paroxysmal atrial fibrillation.

Ablation procedures in patients with paroxysmal atrial fibrillation (PAF) includes isolation of all pulmonary veins (PVs). We hypothesized that an approach using an algorithm to detect arrhythmogenic PVs (aPVs) might lead to shorter procedure duration (PD) and fewer proarrhythmic effects (PE).Isolation of the aPVs only leads to a reduced PD, reduced PEs, and fewer adverse events, with a success rate comparable to the standard all-PV approach.In this prospective trial, 207 patients with PAF were randomized to undergo isolation of the aPV (AG group, n = 105) or isolation of all PVs (VG group, n = 102). The aPV was identified by atrial fibrillation (AF) induction, focal discharge, or short local PV decremental conduction during PV pacing. Patients were followed with repetitive 7-day Holter electrocardiograms (ECGs) after 3, 6, and 12 months in our arrhythmia clinic.In 97% of patients, at least 1 aPV was identified (mean, 2.1). PD did not differ significantly (152.3 ± 57.1 minutes vs 162 ± 68 minutes, P = 0.27) between the groups, but the number of radiofrequency (RF) applications and fluoroscopy time (FT) and dose were significantly lower in the AG group than in the VG group. The occurrence of PE (new-onset atrial tachycardia) and adverse events (AE) did not differ between the 2 groups (P = 0.1). Sinus rhythm off antiarrhythmic medication (documented on 7-day Holter ECGs) 12 months after a single procedure was achieved in 53% in the AG group and 59% in the VG group (P = 0.51).Isolation of the aPVs detected by a straightforward algorithm leads to similar success rates compared to a standard all-PV approach with regard to PD, AE, or PE and is associated with less RF and a shorter FT