Electroreductive Ring-Opening Carboxylation of 1,3-Oxazolidin-2-ones with CO2 for Accessing ß-Amino Acids.

Electrocarboxylation of the C(sp3)-O bond in 1,3-oxazolidin-2-ones with CO2 to achieve ß-amino acids is developed. The C-O bond in substrates can be selectively cleaved via the single electron transfer on the surface of a cathode or through a CO2• - intermediate under additive-free conditions. A great diversity of ß-amino acids can be obtained in a moderate to excellent yield and readily converted to various biologically active compounds.

The stigma of patients with chronic insomnia: a clinical study.

BACKGROUND: The objective of this study was to explore the stigma and related influencing factors in individuals with chronic insomnia disorder (CID). METHODS: A total of 70 CID patients and 70 healthy controls (CON) were enrolled in the study. All subjects completed the assessments of sleep, emotion, and cognition. Their stigma and life quality were measured using the Chronic Stigma Scale and the 36-Item Short-Form Health Survey (SF-36). RESULTS: The ratio of individuals with stigma was significantly different between CID and CON groups (C2 = 35.6, p < 0.001). Compared with the CON group, the CID group had higher scores for total stigma (U = 662.0, p < 0.001), internalized stigma (U = 593.0, p < 0.001), enacted stigma (U = 1568.0, p < 0.001), PSQI (U = 2485.0, p < 0.001) and HAMD-17 (U = 69.5, p < 0.001) as well as lower scores for MoCA-C (U = 3997.5, p < 0.001) and most items of SF-36. Partial correlation analysis showed that different items of the Chronic Stigma Scale were positively correlated with illness duration, PSQI and HAMD-17 scores, while negatively correlated with one or more items of the SF-36. Multivariate regression analysis showed that illness duration and the Mental Health domain of the SF-36 were independent risk factors for one or more items of stigma in CID patients. CONCLUSION: Patients with CID have an increased risk of stigma. Moreover, illness duration and Mental Health may be primary factors related to stigma.

Different roles of TGF-ß in the multi-lineage differentiation of stem cells.

Stem cells are a population of cells that has infinite or long-term self-renewal ability and can produce various kinds of descendent cells. Transforming growth factor ß (TGF-ß) family is a superfamily of growth factors, including TGF-ß1, TGF-ß2 and TGF-ß3, bone morphogenetic proteins, activin/inhibin, and some other cytokines such as nodal, which plays very important roles in regulating a wide variety of biological processes, such as cell growth, differentiation, cell death. TGF-ß, a pleiotropic cytokine, has been proved to be differentially involved in the regulation of multi-lineage differentiation of stem cells, through the Smad pathway, non-Smad pathways including mitogen-activated protein kinase pathways, phosphatidylinositol-3-kinase/AKT pathways and Rho-like GTPase signaling pathways, and their cross-talks. For instance, it is generally known that TGF-ß promotes the differentiation of stem cells into smooth muscle cells, immature cardiomyocytes, chondrocytes, neurocytes, hepatic stellate cells, Th17 cells, and dendritic cells. However, TGF-ß inhibits the differentiation of stem cells into myotubes, adipocytes, endothelial cells, and natural killer cells. Additionally, TGF-ß can provide competence for early stages of osteoblastic differentiation, but at late stages TGF-ß acts as an inhibitor. The three mammalian isoforms (TGF-ß1, 2 and 3) have distinct but overlapping effects on hematopoiesis. Understanding the mechanisms underlying the regulatory effect of TGF-ß in the stem cell multi-lineage differentiation is of importance in stem cell biology, and will facilitate both basic research and clinical applications of stem cells. In this article, we discuss the current status and progress in our understanding of different mechanisms by which TGF-ß controls multi-lineage differentiation of stem cells.

[Exogenous gene expression in vitro and in vivo in bone marrow mesenchymal stem cells modified by hPDGF-A and hBD(2)].

The objective of this study was to investigate the expression of exogenous hPDGF-A and hBD(2) in gene-modified bone marrow mesenchymal stem cells (BM-MSCs) in vitro and in vivo. Recombinant adenovirus vector expressing hPDGF-A/hBD(2) genes was constructed and packaged into virion. Primary isolated and cultured BM-MSCs were transfected by using hPDGF-A hBD(2), then the expressions of exogenous hPDGF-A/hBD(2) were detected by immunocytochemical staining in vitro. The conditioned medium (serum-free cultured supernatant of BM-MSCs transfected with recombinant adenovirus) collected from gene-modified BM-MSCs was applied to scratch wound on monolayer cells of multipotential cell line 10T1/2 in order to confirm the stimulative effect of hPDGF-A on cell migration. Gene-modified BM-MSCs were topically transplanted on wound of rats with radiation and skin excision combined injury. The distribution of BM-MSCs and expression of hPDGF-A/hBD(2) on the wound was observed by fluorescent microscopy and immunohistochemical staining respectively. The results indicated that the rat BM-MSCs transfected with recombinant adenovirus could express the EGFP in vitro. The immunofluorescent cytochemistry assay showed that the gene-modified BM-MSCs expressed the hPDGF-A and hBD(2). The scratch test confirmed that the percentage of healing area of wound in cultured supernatant group of gene-modified BM-MSCs was significant higher than that in control group on 8, 12, 24 and 48 hours (p < 0.05). The fluorescence microscopy of exogenous gene-modified BM-MSCs transplanted on wound revealed that the gene-modified BM-MSCs could higher express exogenous genes of EGFP at least within 2 weeks. The immunohistochemistry staining of wound indicated that the expression of exogenous genes began from day 3, reached to peak on day 7, and still visible on day 21 even though the expression became weak because of the possible dilution of the exogenous genes during cell division. It is concluded that efficient expression of exogenous hPDGF-A/hBD(2) in gene-modified BM-MSCs are demonstrated both in vitro and in vivo, which suggests that the molecular mechanism underlying chronic wound-healing accelerated by the strategy combining cell therapy with gene therapy.