Differentiation of human fetal mesenchymal stem cells into cells with an oligodendrocyte phenotype

This article is available open access through the publisher’s website at the link below. Copyright @ 2009 Landes Bioscience.The potential of mesenchymal stem cells (MSC) to differentiate into neural lineages has raised the possibility of autologous cell transplantation as a therapy for neurodegenerative diseases. We have identified a population of circulating human fetal mesenchymal stem cells (hfMSC) that are highly proliferative and can readily differentiate into mesodermal lineages such as bone, cartilage, fat and muscle. Here, we demonstrate for the first time that primary hfMSC can differentiate into cells with an oligodendrocyte phenotype both in vitro and in vivo. By exposing hfMSC to neuronal conditioned medium or by introducing the pro-oligodendrocyte gene, Olig-2, hfMSC adopted an oligodendrocyte-like morphology, expressed oligodendrocyte markers and appeared to mature appropriately in culture. Importantly we also demonstrate the differentiation of a clonal population of hfMSC into both mesodermal (bone) and ectodermal (oligodendrocyte) lineages. In the developing murine brain transplanted hfMSC integrated into the parenchyma but oligodendrocyte differentiation of these naïve hfMSC was very low. However, the proportion of cells expressing oligodendrocyte markers increased significantly (from 0.2% to 4%) by pre-exposing the cells to differentiation medium in vitro prior to transplantation. Importantly, the process of in vivo differentiation occurred without cell fusion. These findings suggest that hfMSC may provide a potential source of oligodendrocytes for study and potential therapy

The interplay between fluorescence and phosphorescence with luminescent gold(i) and gold(iii) complexes bearing heterocyclic arylacetylide ligands

published_or_final_versio

On the segmentation of astronomical images via level-set methods

Astronomical images are of crucial importance for astronomers since they contain a lot of information about celestial bodies that can not be directly accessible. Most of the information available for the analysis of these objects starts with sky explorations via telescopes and satellites. Unfortunately, the quality of astronomical images is usually very low with respect to other real images and this is due to technical and physical features related to their acquisition process. This increases the percentage of noise and makes more difficult to use directly standard segmentation methods on the original image. In this work we will describe how to process astronomical images in two steps: in the first step we improve the image quality by a rescaling of light intensity whereas in the second step we apply level-set methods to identify the objects. Several experiments will show the effectiveness of this procedure and the results obtained via various discretization techniques for level-set equations.Comment: 24 pages, 59 figures, paper submitte

Two and Three-dimensional Rings in Drugs.

Using small, flat aromatic rings as components of fragments or molecules is a common practice in fragment based drug discovery and lead optimization. With an increasing focus on the exploration of novel biological and chemical space, and their improved synthetic accessibility, 3D fragments are attracting increasing interest. This study presents a detailed analysis of 3D and 2D ring fragments in marketed drugs. Several measures of properties were used, such as the type of ring assemblies and molecular shapes. The study also took into account the relationship between protein classes targeted by each ring fragment, providing target-specific information. The analysis shows the high structural and shape diversity of 3D ring systems and their importance in bioactive compounds. Major differences in 2D and 3D fragments are apparent in ligands that bind to the major drug targets such as GPCRs, ion channels and enzymes. This article is protected by copyright. All rights reserved

Obstructive sleep apnoea: a cause of chronic cough

Chronic cough is a common reason for presentation to both general practice and respiratory clinics. In up to 25% of cases, the cause remains unclear after extensive investigations. We report 4 patients presenting with an isolated chronic cough who were subsequently found to have obstructive sleep apnoea. The cough improved rapidly with nocturnal continuous positive airway pressure therapy. Further studies are required to investigate the prevalence of coexistence of these common conditions

Effect on Baby-Friendly Hospital Steps When Hospitals Implement a Policy to Pay for Infant Formula

Background: The Baby-Friendly Hospital Initiative requires hospitals to pay market price for infant formula. No studies have specifically examined the effect of hospitals paying for infant formula on breastfeeding mothers' exposure to Baby-Friendly steps. Objectives: To investigate the effect of hospitals implementing a policy of paying for infant formula on new mothers' exposure to Baby-Friendly steps and examine the effect of exposure to Baby-Friendly steps on breastfeeding rates. Methods: We used a repeated prospective cohort study design. We recruited 2 cohorts of breastfeeding mother-infant pairs (n = 2470) in the immediate postnatal period from 4 Hong Kong public hospitals and followed them by telephone up to 12 months postpartum. We assessed participants' exposure to 6 Baby-Friendly steps by extracting data from the medical record and by maternal self-report. Results: After hospitals began paying for infant formula, new mothers were more likely to experience 4 out of 6 Baby-Friendly steps. Breastfeeding initiation within the first hour increased from 28.7% to 45%, and in-hospital exclusive breastfeeding rates increased from 17.9% to 41.4%. The proportion of mothers who experienced all 6 Baby-Friendly steps increased from 4.8% to 20.5%. The risk of weaning was progressively higher among participants experiencing fewer Baby-Friendly steps. Each additional step experienced by new mothers decreased the risk of breastfeeding cessation by 8% (hazard ratio = 0.92; 95% CI, 0.89-0.95). Conclusion: After implementing a policy of paying for infant formula, breastfeeding mothers were exposed to more Baby-Friendly steps, and exposure to more steps was significantly associated with a lower risk of breastfeeding cessation.postprin

An Elastic Interaction-Based Loss Function for Medical Image Segmentation

Deep learning techniques have shown their success in medical image segmentation since they are easy to manipulate and robust to various types of datasets. The commonly used loss functions in the deep segmentation task are pixel-wise loss functions. This results in a bottleneck for these models to achieve high precision for complicated structures in biomedical images. For example, the predicted small blood vessels in retinal images are often disconnected or even missed under the supervision of the pixel-wise losses. This paper addresses this problem by introducing a long-range elastic interaction-based training strategy. In this strategy, convolutional neural network (CNN) learns the target region under the guidance of the elastic interaction energy between the boundary of the predicted region and that of the actual object. Under the supervision of the proposed loss, the boundary of the predicted region is attracted strongly by the object boundary and tends to stay connected. Experimental results show that our method is able to achieve considerable improvements compared to commonly used pixel-wise loss functions (cross entropy and dice Loss) and other recent loss functions on three retinal vessel segmentation datasets, DRIVE, STARE and CHASEDB1

Effect of a hospital policy of not accepting free infant formula on in-hospital formula supplementation rates and breast-feeding duration

OBJECTIVE: To investigate the effect of public hospitals in Hong Kong not accepting free infant formula from manufacturers on in-hospital formula supplementation rates and breast-feeding duration. DESIGN: Prospective cohort study. SETTING: In-patient postnatal units of four public hospitals in Hong Kong. SUBJECTS: Two cohorts of breast-feeding mother-infant pairs (n 2560). Cohort 1 (n 1320) was recruited before implementation of the policy to stop accepting free infant formula and cohort 2 (n 1240) was recruited after policy implementation. Participants were followed prospectively for 12 months or until they stopped breast-feeding. RESULTS: The mean number of formula supplements given to infants in the first 24 h was 2·70 (sd 3·11) in cohort 1 and 1·17 (sd 1·94) in cohort 2 (P<0·001). The proportion of infants who were exclusively breast-fed during the hospital stay increased from 17·7 % in cohort 1 to 41·3 % in cohort 2 (P<0·001) and the risk of breast-feeding cessation was significantly lower in cohort 2 (hazard ratio=0·81; 95 % CI 0·73, 0·90). Participants who non-exclusively breast-fed during the hospital stay had a significantly higher risk of stopping any or exclusive breast-feeding. Higher levels of formula supplementation also increased the risk of breast-feeding cessation in a dose-response pattern. CONCLUSIONS: After implementation of a hospital policy to pay market price for infant formula, rates of in-hospital formula supplementation were reduced and the rates of in-hospital exclusive breast-feeding and breast-feeding duration increased.postprin

Peptides Derived from Vascular Endothelial Growth Factor B Show Potent Binding to Neuropilin-1

Vascular endothelial growth factors (VEGFs) regulate significant pathways in angiogenesis, myocardial and neuronal protection, metabolism, and cancer progression. The VEGF-B isoform is involved in cell survival, anti-apoptotic and antioxidant mechanisms, through binding to VEGF receptor 1 and neuropilin-1 (NRP-1). We employed surface plasmon resonance technology and X-ray crystallography to analyse the molecular basis of the interaction between VEGF-B and the b1 domain of NRP-1, and developed VEGF-B - C-terminus derived peptides to be used as chemical tools for studying VEGF-B - NRP-1 related pathways. Peptide lipidation was used as a means to stabilise the peptides. VEGF-B - derived peptides containing a C-terminal arginine show potent binding to NRP1-b1. Peptide lipidation increased binding residence time and improved plasma stability. A crystal structure of a peptide with NRP-1 demonstrated that VEGF-B peptides bind at the canonical C-terminal Arginine binding site. VEGF-B C-terminus imparts higher affinity for NRP-1 than the corresponding VEGF-A_{165} region. This tight binding may impact on the activity and selectivity of the full-length protein. The VEGF-B_{167} derived peptides were more effective than VEGF-A_{165} peptides in blocking functional phosphorylation events. Blockers of VEGF-B function have potential applications in diabetes and non-alcoholic fatty liver disease