Right Heart Remodeling in Patients with End-Stage Alcoholic Liver Cirrhosis: Speckle Tracking Point of View

BACKGROUND: Data regarding cardiac remodeling in patients with alcoholic liver cirrhosis are scarce. We sought to investigate right atrial (RA) and right ventricular (RV) structure, function, and mechanics in patients with alcoholic liver cirrhosis. METHODS: This retrospective cross-sectional investigation included 67 end-stage cirrhotic patients, who were referred for evaluation for liver transplantation and 36 healthy controls. All participants underwent echocardiographic examination including strain analysis, which was performed offline. RESULTS: RV basal diameter and RV thickness were significantly higher in patients with cirrhosis. Conventional parameters of the RV systolic function were similar between the observed groups. Global, endocardial, and epicardial RV longitudinal strains were significantly lower in patients with cirrhosis. Active RA function was significantly higher in cirrhotic patients than in controls. The RA reservoir and conduit strains were significantly lower in cirrhotic patients, while there was no difference in the RA contractile strain. Early diastolic and systolic RA strain rates were significantly lower in cirrhotic patients than in controls, whereas there was no difference in the RA late diastolic strain rate between the two groups. Transaminases and bilirubin correlated negatively with RV global longitudinal strain and RV-free wall strain in patients with end-stage liver cirrhosis. The Model for End-stage Liver Disease (MELD) score, predictor of 3-month mortality, correlated with parameters of RV structure and systolic function, and RA active function in patients with end-stage liver cirrhosis. CONCLUSIONS: RA and RV remodeling is present in patients with end-stage liver cirrhosis even though RV systolic function is preserved. Liver enzymes, bilirubin, and the MELD score correlated with RV and RA remodeling

High-yield production of a super-soluble miniature spidroin for biomimetic high-performance materials

The mechanical properties of artificial spider silks are approaching a stage where commercial applications become realistic. However, the yields of recombinant silk proteins that can be used to produce fibers with good mechanical properties are typically very low and many purification and spinning protocols still require the use of urea, hexafluoroisopropanol, and/or methanol. Thus, improved production and spinning methods with a minimal environmental impact are needed. We have previously developed a miniature spider silk protein that is characterized by high solubility in aqueous buffers and spinnability in biomimetic set-ups. In this study, we developed a production protocol that resulted in an expression level of >20 g target protein per liter in an Escherichia coli fedbatch culture, and subsequent purification under native conditions yielded 14.5 g/l. This corresponds to a nearly six-fold increase in expression levels, and a 10-fold increase in yield after purification compared to reports for recombinant spider silk proteins. Biomimetic spinning using only aqueous buffers resulted in fibers with a toughness modulus of 74 MJ/m(3), which is the highest reported for biomimetically as-spun artificial silk fibers. Thus, the process described herein represents a milestone for the economic production of biomimetic silk fibers for industrial applications

Impact of physio-chemical spinning conditions on the mechanical properties of biomimetic spider silk fibers

Artificial spider silk has emerged as a biobased fiber that could replace some petroleum-based materials that are on the market today. Recent progress made it possible to produce the recombinant spider silk protein NT2RepCT at levels that would make the commercialization of fibers spun from this protein economically feasible. However, for most applications, the mechanical properties of the artificial silk fibers need to be improved. This could potentially be achieved by redesigning the spidroin, and/or by changing spinning conditions. Here, we show that several spinning parameters have a significant impact on the fibers’ mechanical properties by tensile testing more than 1000 fibers produced under 92 different conditions. The most important factors that contribute to increasing the tensile strength are fast reeling speeds and/or employing post-spin stretching. Stretching in combination with optimized spinning conditions results in fibers with a strength of >250 MPa, which is the highest reported value for fibers spun using natively folded recombinant spidroins that polymerize in response to shear forces and lowered pH

postulating a common tumor entity

The set definition of distal cholangiocarcinomas and adenocarcinomas of the pancreatic head is challenged by their close anatomical relation, similar growth pattern, and corresponding therapeutic outcome. They show a mutual development during embryologic organ formation and share phenotypic characteristics. This review will highlight the similarities with regard to the common origin of their primary organs, histopathological similarities, and modern clinical management. Thus, we propose to subsume those entities under a common superfamily

An Image-Analysis-Based Method for the Prediction of Recombinant Protein Fiber Tensile Strength

Silk fibers derived from the cocoon of silk moths and the wide range of silks produced by spiders exhibit an array of features, such as extraordinary tensile strength, elasticity, and adhesive properties. The functional features and mechanical properties can be derived from the structural composition and organization of the silk fibers. Artificial recombinant protein fibers based on engineered spider silk proteins have been successfully made previously and represent a promising way towards the large-scale production of fibers with predesigned features. However, for the production and use of protein fibers, there is a need for reliable objective quality control procedures that could be automated and that do not destroy the fibers in the process. Furthermore, there is still a lack of understanding the specifics of how the structural composition and organization relate to the ultimate function of silk-like fibers. In this study, we develop a new method for the categorization of protein fibers that enabled a highly accurate prediction of fiber tensile strength. Based on the use of a common light microscope equipped with polarizers together with image analysis for the precise determination of fiber morphology and optical properties, this represents an easy-to-use, objective non-destructive quality control process for protein fiber manufacturing and provides further insights into the link between the supramolecular organization and mechanical functionality of protein fibers

Prospect redux

The remote estimation of leaf biochemical content from spaceborne platforms has been the subject of many studies aimed at better understanding of terrestrial ecosystem functioning. The major ecological processes involved in exchange of matter and energy, like photosynthesis, primary production, evaportranspiration, respiration, and decomposition can be related to plant properties e.g., chlorophyll, water, protein, cellulose and lignin contents. As leaves represent the most important plant surfaces interacting with solar energy, a top priority has been to relate optical properties to biochemical constituents. Two different approaches have been considered: first, statistical correlations between the leaf reflectance (or transmittance) and biochemical content, and second, physically based models of leaf scattering and absorption developed using the laws of optics. Recently reviewed by Verdebout et al., the development of models of leaf optical properties has resulted in better understanding of the interaction of light with plant leaves. Present radiative transfer models mainly use chlorophyll and/or water contents as input parameters to calculate leaf reflectance. Inversion of these models allows to retrieve these constituents from spectrophotometric measurements. Conel et al. recently proposed a two-stream Kubelka-Munk model to analyze the influence of protein, cellulose, lignin, and starch on leaf reflectance, but in fact, the estimation of leaf biochemistry from remote sensing is still an open question. In order to clarify it, a laboratory experiment associating visible/infrared spectra of plan leaves both with physical measurements and biochemical analyses was conducted at the Joint Research Center during the summer of 1993. This unique data set has been used to upgrade the PROSPECT model, by including leaf biochemistry