The role of mesenchymal stem cells in hematopoietic stem cell transplantation: prevention and treatment of graft-versus-host disease.

BACKGROUND: The use and effectiveness of hematopoietic stem cell transplantation (HSCT) are limited by lethal complications, i.e., acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively), in which immune cells from the donor attack healthy recipient tissues. GVHD presents both prophylactic and therapeutic challenges, and overall survival is poor. Mesenchymal stem cells (MSCs) show considerable promise in the treatment of GVHD because of their potential immunomodulatory activity. Multiple studies have been performed to explore the possible benefit of MSCs in GVHD, but the results of these studies are sometimes conflicting. Therefore, we performed a systematic review and meta-analysis to estimate the effect of MSC infusion on GVHD treatment and prevention. METHODS: We systematically searched the MEDLINE (PubMed), Cochrane Library, EMBASE, ClinicalTrials.gov, and SinoMed CBM databases to identify studies published before February 2018 involving patients with hematologic malignancies undergoing HSCT and receiving MSC-based or conventional therapy. We included studies if they reported on the outcomes of interest. RESULTS: Ultimately, 10 studies were selected from among 413 candidates. According to our meta-analyses, compared with conventional treatment, MSC therapy demonstrated substantial improvements in terms of complete response (CR) and overall survival for cGVHD. However, MSC therapy did not show substantial improvements in terms of engraftment, the incidence of aGVHD, relapse, death, death due to relapse, or death due to infection. Subgroup analyses showed that MSCs derived from the umbilical cord (U-MSCs) and MSC infusion after HSCT substantially improved engraftment and cGVHD incidence, whereas MSCs derived from bone marrow (B-MSCs) and MSC infusion before HSCT shows no improvement. In addition, B-MSCs and MSC infusion before HSCT tend to prolong engraftment time, as well as increase the rates of relapse and death. CONCLUSIONS: MSC infusion can reduce cGVHD but not aGVHD incidence and showed a positive effect in patients who already had aGVHD. For GVHD prevention, the use of U-MSCs and MSC infusion after HSCT were optimal for reducing cGVHD incidence and promoting engraftment, and might help decrease the incidence rate of relapse and death. However, B-MSCs and MSC infusion before HSCT may be harmful to patients and thus require serious consideration. A lack of robust evidence, owing to the small number of studies and small sample sizes, indicates a need for further high-quality clinical trials including large numbers of patients to validate our findings

Geochemistry of soil gas in the seismic fault zone produced by the Wenchuan Ms 8.0 earthquake, southwestern China

The spatio-temporal variations of soil gas in the seismic fault zone produced by the 12 May 2008 Wenchuan Ms 8.0 earthquake were investigated based on the field measurements of soil gas concentrations after the main shock. Concentrations of He, H2, CO2, CH4, O2, N2, Rn, and Hg in soil gas were measured in the field at eight short profiles across the seismic rupture zone in June and December 2008 and July 2009. Soil-gas concentrations of more than 800 sampling sites were obtained. The data showed that the magnitudes of the He and H2 anomalies of three surveys declined significantly with decreasing strength of the aftershocks with time. The maximum concentrations of He and H2 (40 and 279.4 ppm, respectively) were found in three replicates at the south part of the rupture zone close to the epicenter. The spatio-temporal variations of CO2, Rn, and Hg concentrations differed obviously between the north and south parts of the fault zone. The maximum He and H2 concentrations in Jun 2008 occurred near the parts of the rupture zone where vertical displacements were larger. The anomalies of He, H2, CO2, Rn, and Hg concentrations could be related to the variation in the regional stress field and the aftershock activity

Preparation and Properties of Corn Starch/Chitin Composite Films Cross-Linked by Maleic Anhydride

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films

Polyvinyl Alcohol Microspheres Reinforced Thermoplastic Starch Composites

We reported a new method to prepare polyvinyl alcohol (PVA)/thermoplastic starch (TPS) composites by using polyvinyl alcohol microspheres (PVAMS). The PVAMS/TPS composites were characterized using tensile test, scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results exhibited that adding small amounts of PVAMSs can effectively improve the mechanical strength and toughness of the composites, especially for the 1 wt %PVAMS in TPS matrix, with a tensile strength of 3.5 MPa, an elongation at break at 71.73% and an impact strength of 33.4 kJ/m2. Furthermore, the SEM and shift in the tan δ peak (Tα and Tβ) at the maximum value of 69.87 and −36.52 °C indicates that the PVAMS decreased the mobility of the amorphous starch molecules due to the strong intermolecular hydrogen bonds between PVAMS and TPS. The peak temperature of maximum decomposition rate (Tp) of 1 wt % PVAMS/TPS composites increased about 5 °C compared with TPS in TGA curves

Protective effect of ivabradine on mice with viral myocarditis and its mechanism

549-556Viral myocarditis (VMC) is a type of cardiovascular disease caused by viral infection of myocardial cells characterized by myocardial interstitital inflammatory cell infiltration, myocardial fiber necrosis or figrinolysis. Ivabradine (IVA) is a commonly known drug used to control heart rate, resist inflammation and oxidative stress, particularly in VMC. Here, we have tried to evaluate the protective effects of IVA on mice with VMC and understand the possible mechanism behind this process. Eighty male mice aged 6 weeks old were randomly divided into normal control, VMC model, low-dose IVA (L-IVA) and high-dose IVA (H-IVA) groups. Half an hour after modeling, IVA aqueous solution was administered intragastrically into L-IVA and H-IVA groups at 5 mg·kg-1·d-1 and 20 mg·kg-1·d-1, respectively for 14 consecutive days. Another 120 mice of the same batch were grouped and treated as described above. At 7 and 14 d, 6 mice in each group were sacrificed to obtain blood and heart samples. Body wt./heart wt. (BW/HW) was calculated, hematoxylin-eosin staining was performed to observe the pathological changes of myocardium, and the level of cardiac troponin I (cTnI) was measured by ELISA. Related kits were employed to measure superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and catalase (CAT) activities in myocardial homogenate, and the levels of interleukin-6 (IL-6), IL-18, IL-1β and tumor necrosis factor-α (TNF-α) were determined by double-antibody sandwich ELISA. TUNEL assay was performed to detect the apoptosis of myocardial cells. The protein expressions of Bcl-2, Bax and Caspase-3 in myocardial cells were measured by Western blotting. Compared to the VMC model group, the heart/body weight ratio, myocardial pathological score, cTnI level, MDA activity, and levels of IL-6, IL-18, IL-1β and TNF-α were found decreased, while survival rate and activity of SOD, GSH-Px and CAT increased in L-IVA and H-IVA groups (P <0.05). The apoptosis rate of myocardial cells declined in L-IVA and H-IVA groups (P <0.05), especially in H-IVA group. IVA downregulated the protein expressions of Bax and Caspase-3 and upregulated that of Bcl-2 (P <0.05). Thus, it has been found that IVA elevates the survival rate of VMC mice and relieves myocardial damage possibly by enhancing antioxidant capacity and modulating apoptosis-related proteins to suppress apoptosis

Protective effect of ivabradine on mice with viral myocarditis and its mechanism

Viral myocarditis (VMC) is a type of cardiovascular disease caused by viral infection of myocardial cells characterized by myocardial interstitital inflammatory cell infiltration, myocardial fiber necrosis or figrinolysis. Ivabradine (IVA) is a commonly known drug used to control heart rate, resist inflammation and oxidative stress, particularly in VMC. Here, we have tried to evaluate the protective effects of IVA on mice with VMC and understand the possible mechanism behind this process. In order to complete the study, eighty male mice aged 6 weeks old were randomly divided into normal control, VMC model, low-dose IVA (L-IVA) and high-dose IVA (H-IVA) groups. Half an hour after modeling, IVA aqueous solution was administered intragastrically into L-IVA and H-IVA groups at 5 mg·kg-1·d-1 and 20 mg·kg-1·d-1, respectively for 14 consecutive days. Another 120 mice of the same batch were grouped and treated as described above. At 7 and 14 d, 6 mice in each group were sacrificed to obtain blood and heart samples. Body weight/heart weight (BW/HW) was calculated, hematoxylin-eosin staining was performed to observe the pathological changes of myocardium, and the level of cardiac troponin I (cTnI) was measured by ELISA. Related kits were employed to measure superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and catalase (CAT) activites in myocardial homogenate, and the levels of interleukin-6 (IL-6), IL-18, IL-1β and tumor necrosis factor-α (TNF-α) were determined by double-antibody sandwich ELISA. TUNEL assay was performed to detect the apoptosis of myocardial cells. The protein expressions of Bcl-2, Bax and Caspase-3 in myocardial cells were measured by Western blotting. Compared to the VMC model group, the heart/body weight ratio, myocardial pathological score, cTnI level, MDA activity, and levels of IL-6, IL-18, IL-1β and TNF-α were found decreased, while survival rate and activity of SOD, GSH-Px and CAT increased in L-IVA and H-IVA groups (P &lt;0.05). The apoptosis rate of myocardial cells declined in L-IVA and H-IVA groups (P &lt;0.05), especially in H-IVA group. IVA downregulated the protein expressions of Bax and Caspase-3 and upregulated that of Bcl-2 (P &lt;0.05). Thus, it has been found that IVA elevates the survival rate of VMC mice and relieves myocardial damage possibly by enhancing antioxidant capacity and modulating apoptosis-related proteins to suppress apoptosis

Bio-Based Thermoplastic Starch Composites Reinforced by Dialdehyde Lignocellulose

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7&deg;