Placenta-derived mesenchymal stem cells in promoting acute skin wound healing in rats / 中国组织工程研究

BACKGROUND:Currently,a variety of mesenchymal stem cells have been confirmed to have the effect of promoting wound repair,but there is still a lack of relevant research on whether placenta-derived mesenchymal stem cells can promote acute skin wound healing. OBJECTIVE:To investigate the effect of placenta-derived mesenchymal stem cell transplantation on the healing of acute skin wound in rats. METHODS:Twenty SD rats were divided into PBS group and stem cell group by the random number table method,with 10 rats in each group.All rats were selected to establish a full-thickness skin defect model.In the PBS group and stem cell group,PBS buffer and placenta-derived mesenchymal stem cells were immediately injected on the wound surface and wound margin immediately and on day 8 after modeling.The wound healing was observed immediately and on days 2,4,6,8,10,12,and 14 after modeling.The skin tissue of the wound surface was taken on day 14 and treated with hematoxylin-eosin staining,Masson staining,immunohistochemical staining and immunofluorescence staining. RESULTS AND CONCLUSION:(1)The wound surface of the rats in each group decreased with the prolongation of treatment time.The wound healing rate and wound epithelization rate of the stem cell group at 14 days were higher than those of the PBS group(P<0.01),and the wound contracture rate was lower than that of the PBS group(P<0.01).(2)The results of hematoxylin-eosin staining showed that the skin wound healing of the stem cell group was better than that of the PBS group;the degree of wound epithelization was higher,and the morphology of collagen fibers was close to that of normal skin.(3)Masson staining results showed that compared with the PBS group,collagen fibers in the skin wound tissue of the stem cell group were significantly increased and thicker,and the content of collagen fibers in the new tissue was significantly higher than that of the PBS group(P<0.01).(4)Immunohistochemical staining showed that the number of new capillaries in the stem cell group was higher than that in the PBS group(P<0.01),while the expressions of tumor necrosis factor-α and interleukin-6 were lower than those in the PBS group(P<0.01).(5)Immunofluorescence staining showed that the number of M2 macrophages in the new wounds of the stem cell group was higher than that of the PBS group(P<0.01),while the number of M1 macrophages was less than that in the PBS group(P<0.01).These findings indicate that placenta-derived mesenchymal stem cells can accelerate skin wound healing,promote wound epithelization,and reduce wound contracture,which may be related to the promotion of capillary angiogenesis,regulation of collagen fiber production,inhibition of inflammation,and regulation of macrophage polarization to M2 type.

Development of an online radioactive xenon gas monitoring system for nuclear facilities / 中国辐射卫生

Objective Nowadays, radioactive xenon isotopes, including 131mXe, 133mXe, 133Xe, and 135Xe, are primarily released into the atmosphere through various reactor operation and major accidents of reactors. To improve the online monitoring capability of xenon in nuclear facilities and their gaseous effluents, a highly sensitive online xenon monitoring system was developed to monitor, warn, and alarm the activity concentration of radioactive xenon. Methods The online monitoring system for radioactive xenon gas in nuclear facilities was established using xenon membrane separation and concentration, xenon high-efficiency selective adsorption, and low-background gamma-ray spectrometry analysis methods. Results Under the operation mode of one-hour sampling and one-hour measuring, the minimum detectable activity concentration of the radioactive xenon online monitoring system for 133Xe was approximately (1.43 ± 0.03) Bq/m3. Conclusion This system can be effectively used for online monitoring of xenon activity concentration in nuclear facilities such as nuclear power plants and isotope production reactors, as well as in gaseous effluents. It helps improve the safety level of personnel, the environment, and nuclear facilities.

Effect of non-surgical periodontal therapy on level of serum soluble intercellular adhesion molecule-1 and glycated hemoglobin A1c in patients with type 2 diabetes and chronic periodontitis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of non-surgical periodontal treatment on clinical periodontal measurements, glycemic control, and level of serum soluble intercellular adhesion molecule-1 (sICAM-1) in type 2 diabetes mellitus with chronic periodontitis patients.</p><p><b>METHODS</b>Patients with type 2 diabetes and chronic periodontitis were selected and classified into well-controlled group[glycated hemoglobin Ac(GHbA1)<7.00%, n=30, DMCP1 group] and poorly-controlled group (GHbAc > or = 7.00%, n = 30, DMCP2 group). Thirty systemically healthy patients with chronic periodontitis were recruited as control group (CP group). All subjects underwent non-surgical periodontal therapy. Plaque index(PLI), sulcus bleeding index(SBI), bleeding on probing (BOP), probing depth(PD), clinical attachment loss (CAL), serum sICAM-1 concentration, and the value of fasting plasma glucose(FPG), GHbAc were recorded at baseline, 1 and 3 months after periodontal treatment.</p><p><b>RESULTS</b>The three study groups showed significant improvements for the levels of PD, SBI, PLI, BOP, and serum sICAM-1 concentration at 1 and 3 months after non-surgical periodontal treatment (P < 0.05). The level of CP group and DMCP1 group also showed significant improvements for the levels of CAL (P < 0.05), but no significant change was found in DMCP2 group (P > 0.05). At 3 months after periodontal treatment, GHbA1c levels in DMCP2 group significantly decreased by 1.12% (P < 0.05), whereas no significant changes were found in CP and DMCT groups (P > 0.05).</p><p><b>CONCLUSION</b>Non-surgical periodontal treatment can siginificantly improve periodontal health status in patients with type 2 diabetes and periodontitis, reduce the level of serum sICAM-1, and can reduce the level of GHbA1c in poorly controlled type 2 diabetic patients.</p>

Effect of different porcelain-fused-to-metal crown inner metal materials on the level of soluble intercellular adhesion molecule-1 and interleukin-1beta in gingival crevicular fluid / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of different inner metal materials of porcelain-fused-to-metal (PFM) crown on periodontal tissue by means of measuring the level of soluble intercellular adhesion molecule-1 (sICAM-1) and interleukin-1beta (IL-1beta) in gingival crevicular fluid (GCF) after PFM restorations.</p><p><b>METHODS</b>30 teeth were divided into three groups (Ni-Cr alloy group, Co-Cr alloy group and Au-Pt alloy group, 10 teeth each group), and restored by Ni-Cr alloy, Co-Cr alloy and Au-Pt alloy PFM crown according grouping. At the point of pre-restoration, 6-month and 12-month after cementation, the clinical parameters including plaque index (PLI), gingival index (GI) and gingival crevice depth (GCD) were detected, and GCF was collected from labial and lingual of mesial site and distal site. The level of sICAM-1 and IL-1beta were detected.</p><p><b>RESULTS</b>At the point of 6-month and 12-month after cementation, Ni-Cr alloy group showed significant difference for GI, GCD and all GCF indexes when compared to pre-restoration, Co-Cr alloy group and Au-Pt alloy group (P < 0.05). At the point of 12-month after cementation, Co-Cr alloy group showed significant difference for GI, GCD and all GCF indexes when compared to pre-restoration and Au-Pt alloy group (P < 0.05). All indexes have no significant difference for Au-Pt alloy group during the 12-month experiment times when compared to pre-restoration (P > 0.05).</p><p><b>CONCLUSION</b>Non-noble metal has bad effect on the periodontal tissue.</p>