Novel light treatment for digital ulcers in systemic sclerosis: a feasibility study

Background

Locally acting, well-tolerated treatments for digital ulcers in patients with systemic sclerosis are needed. We aimed to investigate the safety, feasibility, and tolerability of a novel light treatment, and to tentatively assess treatment efficacy.

Universal architecture of bacterial chemoreceptor arrays

Chemoreceptors are key components of the high-performance signal transduction system that controls bacterial chemotaxis. Chemoreceptors are typically localized in a cluster at the cell pole, where interactions among the receptors in the cluster are thought to contribute to the high sensitivity, wide dynamic range, and precise adaptation of the signaling system. Previous structural and genomic studies have produced conflicting models, however, for the arrangement of the chemoreceptors in the clusters. Using whole-cell electron cryo-tomography, here we show that chemoreceptors of different classes and in many different species representing several major bacterial phyla are all arranged into a highly conserved, 12-nm hexagonal array consistent with the proposed “trimer of dimers” organization. The various observed lengths of the receptors confirm current models for the methylation, flexible bundle, signaling, and linker sub-domains in vivo. Our results suggest that the basic mechanism and function of receptor clustering is universal among bacterial species and was thus conserved during evolution.     

Validity of a three-dimensional public-domain system for contemporary endodontic research

The purpose of this study was to evaluate the limits and benefits of a visualization system based on public-domain software for contemporary three-dimensional (3-D) endodontic research purposes. Three-dimensional bio-models of six human teeth and of one bone-implant specimen were generated using cross-sectional imaging. To evaluate the overall performance in processing large data sets and in reproducing accurate 3-D morphology, slices with a thickness varying from 100 microm to 10 microm were cut. Auto-outlining and segmenting techniques were tested. The 3-D bio-models represented in accurate detail the different morphological aspects of the specimen. Voxel volumes of 0.116 x 10(-5) mm3 could be realized and were only restricted by the computer hardware limitations. The system is not limited to dental hard tissues. Hypomineralized material and soft tissues as well as bone- and allogeneic-implant material could be visualized. The method presented is valid and meets current requirements applying to endodontic research. The broad-based use of high-quality, public-domain software and the resulting exchange of experience help to manage resources and may contribute to enhancing the in-process quality of research.