Dietary pattern, colonic microbiota and immunometabolism interaction: new frontiers for diabetes mellitus and related disorders

In this review, the numerous possible mechanisms that provide supportive evidence for how colonic dysbiosis denotes metabolic dysfunction, dysregulates glucose homeostasis and leads to diabetes mellitus and related metabolic disorders are defined. Information was gathered from articles identified by systematic reviews and searches using Google, PubMed and Scopus. The composition of the colonic microbiota plays an integral role in maintaining host homeostasis by affecting both metabolic activities and underlying functional gene transcription in individuals with diabetes and related metabolic disorders. Increased colonic microbiome-derived concentrations of lipopolysaccharides, also known as 'metabolic endotoxaemia', as well as alterations in bile acid metabolism, short-chain fatty acids, intestinal hormones and branched-chain amino acid secretion have been associated with the diverse production of pro-inflammatory cytokines and the recruitment of inflammatory cells. It has been shown that changes to intestinal bacterial composition are significant even in early childhood and are associated with the pathogenesis of both types of diabetes. We hope that an improved understanding of related mechanisms linking the colonic microbiome with glucose metabolism might provide for innovative therapeutic approaches that would bring the ideal intestinal ecosystem to a state of optimal health, thus preventing and treating diabetes and related metabolic disorders.

A new HPF specimen carrier adapter for the use of high-pressure freezing with cryoscanning electron microscope: two applications: stearic acid organization in a hydroxypropyl methylcellulose matrix and mice myocardium

Cryogenic transmission electron microscopy of high-pressure freezing (HPF) samples is a well-established technique for the analysis of liquid containing specimens. This technique enables observation without removing water or other volatile components. The HPF technique is less used in scanning electron microscopy (SEM) due to the lack of a suitable HPF specimen carrier adapter. The traditional SEM cryotransfer system (PP3000T Quorum Laughton, East Sussex, UK; Alto Gatan, Pleasanton, CA, USA) usually uses nitrogen slush. Unfortunately, and unlike HPF, nitrogen slush produces water crystal artefacts. So, we propose a new HPF specimen carrier adapter for sample transfer from HPF system to cryogenic-scanning electronic microscope (Cryo-SEM). The new transfer system is validated using technical two applications, a stearic acid in hydroxypropyl methylcellulose solution and mice myocardium. Preservation of samples is suitable in both cases. Cryo-SEM examination of HPF samples enables a good correlation between acid stearic liquid concentration and acid stearic occupation surface (only for homogeneous solution). For biological samples as myocardium, cytoplasmic structures of cardiomyocyte are easily recognized with adequate preservation of organelle contacts and inner cell organization. We expect this new HPF specimen carrier adapter would enable more SEM-studies using HPF.

Close-packing transitions in clusters of Lennard-Jones spheres

The structures of clusters of spherical and homogeneous particles are investigated using a combination of global optimization methods. The pairwise potential between particles is integrated exactly from elementary Lennard-Jones interactions, and the use of reduced units allows us to get insight into the effects of the particle diameter. As the diameter increases, the potential becomes very sharp, and the cluster structure generally changes from icosahedral (small radius) to close-packed cubic (large radius), possibly through intermediate decahedral shapes. The results are interpreted in terms of the effective range of the potential.