Viral envelope proteins are always proposed to exert important function during virus infection and replication. Vertebrate iridoviruses are enveloped large DNA virus, which can cause great economic losses in aquaculture and ecological destruction. Although numerous iridovirus envelope proteins have been identified using bioinformatics and proteomic methods, their roles in virus infection remained largely unknown.
Liver cancer remains a significant medical problem and one promising therapeutic approach is to embolize the tumor. One emerging embolization strategy is to use thermoresponsive materials that can be injected but gel at the tumor site. It is now reported on thermoresponsive nanocomposites generated by grafting poly(N-isopropylacrylamide) chains on bacterial cellulose nanowhiskers. Chemical and physical evidences are provided for grafting and demonstrated a sol-gel transition when the temperature is increased above 34.3 °C. Cytotoxicity test in human umbilical vein endothelial cells indicates the excellent biocompatibility of these nanocomposites for use as embolic materials. These results suggest that the nanocomposites offer appropriate properties for embolization of hepatocellular carcinoma.
The Pacific white shrimp, Litopenaeus vannamei, is a worldwide cultured crustacean species with important commercial value. Over the last two decades, Taura syndrome virus (TSV) has seriously threatened the shrimp aquaculture industry in the Western Hemisphere. To better understand the interaction between shrimp immune and TSV, we performed a transcriptome analysis in the hepatopancreas of L. vannamei challenged with TSV, using the 454 pyrosequencing (Roche) technology.
Pacific white shrimp (Litopenaeus vannamei) is the most extensively farmed crustacean species in the world. White spot syndrome virus (WSSV) is one of the major pathogens in the cultured shrimp. However, the molecular mechanisms of the host-virus interaction remain largely unknown. In this study, the impact of WSSV infection on host gene expression in the hepatopancreas of L. vannamei was investigated through the use of 454 pyrosequencing-based RNA-Seq of cDNA libraries developed from WSSV-challenged shrimp or normal controls. By comparing the two cDNA libraries, we show that 767 host genes are significantly up-regulated and 729 genes are significantly down-regulated by WSSV infection. KEGG analysis of the differentially expressed genes indicated that the distribution of gene pathways between the up- and down-regulated genes is quite different. Among the differentially expressed genes, several are found to be involved in various processes of animal defense against pathogens such as apoptosis, mitogen-activated protein kinase (MAPK) signaling, toll-like receptor (TLR) signaling, Wnt signaling and antigen processing and presentation pathways. The present study provides valuable information on differential expression of L. vannamei genes following WSSV infection and improves our current understanding of this host-virus interaction. In addition, the large number of transcripts obtained in this study provides a strong basis for future genomic research on shrimp.
Sclerosis (tissue hardening) development is a common occurrence in slow growing or benign osteolytic lesions. However, there is lack of knowledge on the mechanical and material property changes associated with sclerotic bone response. The immune system is postulated to play a relevant role in evoking sclerotic bone responses. In this study, localized sclerotic response in an immunocompetent model of Walker 256 breast carcinoma in SD rats showed an apparent increase in new reactive bone formation. Sclerotic rat femurs had significant increases in bone mineral density (BMD), bone mineral content (BMC), bone volume fraction (BV/TV), bone surface density (BS/TV), trabecular number (Tb.N) and a significant decrease in trabecular separation (Tb.Sp) and structural model index (SMI) as compared to control rat femurs. Significantly reduced creep responses (increased ?) were observed for both trabecular and cortical bone in sclerotic bones while no significant difference was observed in elastic modulus (E) and hardness (H) values. Therefore, we conclude that viscoelastic creep property using nanoindentation would serve as a more sensitive indicator of localized bone modeling than elastic properties. Moreover, reduced viscoelasticity can contribute towards increased microcrack propagation and therefore reduced toughness. Since significant positive correlations between elastic properties (E) and (H) with viscosity (?) were also observed, our results indicate that sclerotic response of bone metastasis would cause reduced toughness (increased ?) with stiffening of material (increased E and H).
To evaluate the change in phosphatase and tensin homology deleted on chromosome ten (PTEN) expression in liver fibrogenesis, particularly the reversal of fibrogenic liver tissues, and to investigate the relation with the proliferation and apoptosis of hepatic stellate cells (HSCs) in vivo, a rat model of hepatic fibrosis was established by hypodermic injection of carbon tetrachloride (CCl4) mixed with olive oil at the concentration of 40% for 5 weeks (2 ml/kg, twice a week). Reversal of fibrosis was achieved with normal feedings for 4 weeks after CCl4 injection for 5 weeks. The expression of PTEN was measured by immunofluorescence, western blot analysis and real-time PCR. Co-expression of ?-smooth muscle actin (?-SMA) with PTEN and ?-SMA with terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) were assessed by confocal laser scanning microscopy. The results displayed that the expression of PTEN was reduced with fibrosis in both rat liver tissues and activated HSCs. By contrast, PTEN expression was increased with the reversal of liver fibrosis. Compared to the fibrogenic state, there were increased numbers of apoptotic activated HSCs during reversal of fibrosis. These data suggest that the dynamic expression of PTEN in rat liver tissues is negatively correlated with liver fibrosis and activated HSCs and is positively correlated with reversal of fibrosis and apoptotic activated HSCs. Modulation of PTEN expression may be an effective and novel method for the treatment of liver fibrosis.
Establishing a biology-device interface might enable the interaction between microelectronics and biotechnology. In this study, electroactive hydrogels have been produced using bacterial cellulose (BC) and conducting polymer (CP) deposited on the BC hydrogel surface to cover the BC fibers. The structures of these composites thus have double networks, one of which is a layer of electroactive hydrogels combined with BC and CP. The electroconductivity provides the composites with capabilities for voltage and current response, and the BC hydrogel layer provides good biocompatibility, biodegradability, bioadhesion and mass transport properties. Such a system might allow selective biological functions such as molecular recognition and specific catalysis and also for probing the detailed genetic and molecular mechanisms of life. A BC-CP composite hydrogel could then lead to a biology-device interface. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) are used here to study the composite hydrogels electroactive property. BC-PAni and BC-PPy respond to voltage changes. This provides a mechanism to amplify electrochemical signals for analysis or detection. BC hydrogels were found to be able to support the growth, spreading and migration of human normal skin fibroblasts without causing any cytotoxic effect on the cells in the cell culture. These double network BC-CP hydrogels are biphasic Janus hydrogels which integrate electroactivity with biocompatibility, and might provide a biology-device interface to produce implantable devices for personalized and regenerative medicine.
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