Correlative Live Cell and Super Resolution Imaging of Autophagosome Formation

Autophagy is a highly dynamic intracellular process involving interactions between protein complexes and membranes. Direct observation of these components in living cells provides information on how they interact and when and where they are involved in the autophagy pathway. This chapter provides an overview of methods used to acquire images of fluorescently labeled components of the autophagy pathway in living cells using wide-field microscopy. Due to the diffraction-limited nature of this technique further details are provided on how to acquire postfixation correlative super resolution images from the same cells that have previously been imaged live. Combining these techniques offers an opportunity to follow the processes of autophagy in living cells with unprecedented detail.

Transcatheter closure of perimembranous ventricular septal defects with the Amplatzer asymmetric ventricular septal defect occluder: preliminary experience in children

OBJECTIVE

To close perimembranous ventricular septal defects (PMVSDs) in children with the new Amplatzer asymmetric ventricular septal defect occluder (AAVSDO).

PATIENTS AND DESIGN

10 children, aged 1.5-12 years, with PMVSDs underwent transcatheter closure with the AAVSDO. The device consists of two low profile disks made of Nitinol wire mesh with a 1.5 mm connecting waist. The left disk is 5 mm towards the apex and only 0.5 mm towards the aortic valve. The right disk is 4 mm larger than the waist. The prosthesis diameter was chosen to be 1-2 mm larger than the largest diameter of the defect (determined by transoesophageal echocardiography and angled angiocardiography). A 7-8 French gauge sheath was used to deliver the AAVSDO.

RESULTS

The PMVSD diameter ranged from 2-8 mm. The device diameter ranged from 4-8 mm. After deployment of the prosthesis there was no residual shunt in 9 of 10 patients (90%). In one patient there was a trivial residual shunt that disappeared at the three month follow up. Three patients developed transient complete left bundle branch block. No other complications were observed.

CONCLUSIONS

The AAVSDO appears to be a promising device for transcatheter closure of PMVSDs in children. Further studies are required to document its efficacy, safety, and long term results in a larger patient population.