[Ligusticum cycloprolactam inhibits IL-1ß-induced apoptosis and inflammation of rat chondrocytes via HMGB1/TLR4/NF-κB signaling pathway].

Chondrocytes are unique resident cells in the articular cartilage, and the pathological changes of them can lead to the occurrence of osteoarthritis(OA). Ligusticum cycloprolactam(LIGc) are derivatives of Z-ligustilide(LIG), a pharmacodynamic marker of Angelica sinensis, which has various biological functions such as anti-inflammation and inhibition of cell apoptosis. However, its protective effect on chondrocytes in the case of OA and the underlying mechanism remain unclear. This study conducted in vitro experiments to explore the molecular mechanism of LIGc in protecting chondrocytes from OA. The inflammation model of rat OA chondrocyte model was established by using interleukin-1ß(IL-1ß) to induce. LIGc alone and combined with glycyrrhizic acid(GA), a blocker of the high mobility group box-1 protein(HMGB1)/Toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) signaling pathway, were used to intervene in the model, and the therapeutic effects were systematically evaluated. The viability of chondrocytes treated with different concentrations of LIGc was measured by the cell counting kit-8(CCK-8), and the optimal LIGc concentration was screened out. Annexin V-FITC/PI apoptosis detection kit was employed to examine the apoptosis of chondrocytes in each group. The enzyme-linked immunosorbent assay(ELISA) was employed to measure the expression of cyclooxygenase-2(COX-2), prostaglandin-2(PGE2), and tumor necrosis factor-alpha(TNF-α) in the supernatant of chondrocytes in each group. Western blot was employed to determine the protein levels of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), caspase-3, HMGB1, TLR4, and NF-κB p65. The mRNA levels of HMGB1, TLR4, NF-κB p65, and myeloid differentiation factor 88(MyD88) in chondrocytes were determined by real-time fluorescent quantitative PCR(RT-qPCR). The safe concentration range of LIGc on chondrocytes was determined by CCK-8, and then the optimal concentration of LIGc for exerting the effect was clarified. Under the intervention of IL-1ß, the rat chondrocyte model of OA was successfully established. The modeled chondrocytes showed increased apoptosis rate, promoted expression of COX-2, PGE2, and TNF-α, up-regulated protein levels of Bax, caspase-3, HMGB1, TLR4, and NF-κB p65 and mRNA levels of HMGB1, TLR4, NF-κB p65, and MyD88, and down-regulated protein level of Bcl-2. However, LIGc reversed the IL-1ß-induced changes of the above factors. Moreover, LIGc combined with GA showed more significant reversal effect than LIGc alone. These fin-dings indicate that LIGc extracted and derived from the traditional Chinese medicine A. sinensis can inhibit the inflammatory response of chondrocytes and reduce the apoptosis of chondrocytes, and this effect may be related to the HMGB1/TLR4/NF-κB signaling pathway. The pharmacological effect of LIGc on protecting chondrocytes has potential value in delaying the progression of OA and improving the clinical symptoms of patients, and deserves further study.

Development of a PHMB hydrogel-modified wound scaffold dressing with antibacterial activity.

Current wound scaffold dressing constructs can facilitate wound healing but do not exhibit antibacterial activity, resulting in high infection rates. We aimed to endow wound scaffold dressing with anti-infective ability by polyhexamethylenebiguanide (PHMB). We prepared PHMB hydrogel at varying concentrations (0.25%, 0.5%, 1%, 2%) and assessed release and cytotoxicity. PHMB hydrogel was added to the wound scaffold dressing to generate a PHMB hydrogel-modified wound scaffold dressing. Wound healing and infection prevention were evaluated using a full-thickness skin defect model in rats. In vitro, the hydrogel PHMB release time positively correlated with PHMB concentration, with 1% allowing sufficiently long release time to encompass the high-incidence period (3-5 days) of infection following wound scaffold dressing implantation. Implantation of 1% PHMB hydrogel into the skin did not cause adverse responses. in vitro cytotoxicity assays showed the PHMB hydrogel-modified wound scaffold dressing did not significantly affect proliferation of fibroblasts or vascular endothelial cells, 99.90% vs 99.84% for fibroblasts and 100.21% vs 99.28% for vascular endothelial cells at 21 days. Transplantation of PHMB hydrogel-modified wound scaffold dressing/unmodified wound scaffold dressing on the non-infected wounds of rats yielded no significant difference in relative vascularization rate, 47.40 vs 50.87 per view at 21 days, whereas bacterial content of the wound tissue in the PHMB hydrogel-modified wound scaffold dressing group was significantly lower than the unmodified wound scaffold dressing group, (1.80 ± 0.35) × 103 vs (9.34 ± 0.45) × 103 at 14 days. Prevalence of persistent wound infection in the rats receiving PHMB hydrogel-modified wound scaffold dressing transplantation onto infected wounds was significantly lower than the unmodified wound scaffold dressing group, 30% vs 100%. PHMB hydrogel-modified wound scaffold dressing exhibited suitable antibacterial ability, and its biological activity did not significantly differ from that of the unmodified wound scaffold dressing, thereby allowing it to effectively prevent infection following wound scaffold dressing implantation.

Using negative pressure wound therapy on microskin autograft wounds.

BACKGROUND: Microskin autografts with conventional wrap and compression are used extensively in the treatment of skin and tissue defects. This comparative study aimed at investigation of the clinical application of negative pressure wound therapy (NPWT) in combination with microskin autografts for repair of acute and chronic wounds. METHODS: A prospective case-control study was performed from December 1, 2010-December 31, 2013 in Changhai Hospital, Shanghai. We compared a study group of patients received microskin autografting covered by NPWT with that of a control group of patients received microskin autografting covered by a conventional gauze. RESULTS: A total of 81 patients were in this study, 27 patients were allocated to the study group and 54 patients to the control group. The study group exhibited significant low infection rate and pain score during removal of inner layer at first dressing change after skin grafting compared with those of the control group (P < 0.05). The time interval between skin grafting and first postoperative change was longer in the study group than that in the control group (P < 0.01), the study group showed a significant shorter 95% wound healing time (P < 0.05), and survival rate of microskin autografts in the study group was higher than that in the control group (P < 0.05). CONCLUSIONS: NPWT is beneficial for wound closure after microskin autografts, which prolongs the interval between skin transplantation and first postoperative dressing change, reduces pain during removal of inner layer dressing, increases skin graft survival rate, and shortens wound healing time. Therefore, NPWT can be recommended for repair of acute and chronic wounds with microskin autografts.

The complete mitochondrial genome of the Great evening bat Ia io (Chiroptera: Vespertiilionidae) from karst area, Southwestern China.

In this study, the complete mitochondrial genome of Ia io from Guizhou Province, China. The genome was a circular mitochondrial genome of 16689 bp in length, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNA), 2 ribosomal RNA genes (rRNA), and a control region. The average base composition is 32.76% A, 24.59% C, 14.49% G, and 28.16% T. The first complete mitochondrial genome of I. io provides fundamental data for future systematic taxonomic studies of the genus Ia.

Metabolically Specific In Situ Fluorescent Visualization of Bacterial Infection on Wound Tissues.

The ability to effectively detect bacterial infection in human tissues is important for the timely treatment of the infection. However, traditional techniques fail to visualize bacterial species adhered to host cells in situ in a target-specific manner. Dihydropteroate synthase (DHPS) exclusively exists in bacterial species and metabolically converts p-aminobenzoic acid (PABA) to folic acid (FA). By targeting this bacterium-specific metabolism, we have developed a fluorescent imaging probe, PABA-DCM, based on the conjugation of PABA with a long-wavelength fluorophore, dicyanomethylene 4H-pyran (DCM). We confirmed that the probe can be used in the synthetic pathway of a broad spectrum of Gram-positive and negative bacteria, resulting in a significantly extended retention time in bacterial over mammalian cells. We validated that DHPS catalytically introduces a dihydropteridine group to the amino end of the PABA motif of PABA-DCM, and the resulting adduct leads to an increase in the FA levels of bacteria. We also constructed a hydrogel dressing containing PABA-DCM and graphene oxide (GO), termed PABA-DCM@GO, that achieves target-specific fluorescence visualization of bacterial infection on the wounded tissues of mice. Our research paves the way for the development of fluorescent imaging agents that target species-conserved metabolic pathways of microorganisms for the in situ monitoring of infections in human tissues.

[Comparison of clinical effect of two different Kirschner wire fixations after closed reduction on supracondylar fracture of humerus in children with Gartlandâ ¡and â ¢].

OBJECTIVE: To compare clinical effect of Kirschner wire radial sector fixation and bilateral ulnar radial cross fixation in treating supracondylar fracture of humerus in children after closed reduction. METHODS: From March 2017 to December 2018, 60 children with supracondylar fracture of humerus treated with closed reduction and Kirschner wire fixation were analyzed retrospectively, and divided into two groups according to different needling methods. Thirty patients in radial three needles fan fixation group (group A), including 19 males and 11 females, aged from 2 to 10 years old with an average of (5.00±2.10) years old, 21 patients were typeⅡ and 9 patients were typeⅢ according to Gartland classification. Thirty patients in cross fixationwith 3 needles on both ulnar and radial side group(group B), including 22 males and 8 females, aged from 1 to 9 years old with an average of(5.13±2.08) years old, 19 patients were typeⅡand 11 patients were typeⅢ. Healing time of fracture, postoperative complications, elbow flexion and extension activity, forearm rotation activity recovery, elbow carrying angle and angle loss after operation between two groups were observed and compared. Mayo Elbow function score at the final following up was used to evaluate clinical efficacy. RESULTS: All patients were followed up, while there were no significant difference in follow-up time and fracture healing time between two groups (P>0.05);there was 1 patient occurred iatrogenic ulnar nerve injury in group A, 9 patients in group B, and there was difference between two groups (P<0.01);2 patients in group A occurred mild displacement and 1 patient in group B, while no significant difference between two groups(P>0.05). No cubitus varus deformity, needle infection, osteofascial compartment syndrome and myositis ossificans occurred. There was no significant difference in elbow flexion, extension activity, and forearm rotation activity between two groups at 3 months after operation(P>0.05); there was no significant difference in elbow carrying angle and its loss angle between two groups at 3 and 6 months after operation (P>0.05);there was also no significant difference in Mayo Elbow function score and efficacy evaluation at the final follow-up (P>0.05). CONCLUSION: Closed reduction and Kirschner wire at the early stage of fracture has advantages of less trauma, easy reduction, stable fixation, and early functional exercise. The risk of iatrogenic ulnar nerve injury caused by fan-shaped fixation of three radial needles is less than that of cross fixation of three radial needles.

[Research of high frequency induced thermotherapy efficiency for treatment of hepatocellular carcinoma].

OBJECTIVE: To investigate the effectiveness of high frequency induced thermotherapy in the treatment of hepatocellular carcinoma. METHODS: We included a 65 proven cases of hepatocellular carcinoma in which the diagnosis was confirmed by pathology, radio-imaging and AFP value. The patients were randomly divided into 2 group by odd or even hospitalization number. A total of 32 patients were enrolled in the TACE + PEI only group and 33 patients were enrolled in the TACE + HITT therapy group. RESULTS: For the 32 patients in TACE + PEI only therapy group, the 1, 2, and 3 year of survival rates were 73%, 56%, and 23%, respectively, with a median survival of 1.876 years. For patients in the therapy group, the 1, 2, and 3 year survival rates were 87%, 76%, and 51%, respectively, with a median survival of 2.134 years. Survival rate and duration in the therapy group was significantly greater in the combination therapy group compared to the control group (P < 0.05). There was a negative correlation between the effectiveness of combination therapy and the mortality risk (P < 0.05). CONCLUSION: HiTT + TACE can significantly increase survival rate and extend length of survival in patients with hepatocellular carcinoma.

Targeted release of stromal cell-derived factor-1α by reactive oxygen species-sensitive nanoparticles results in bone marrow stromal cell chemotaxis and homing, and repair of vascular injury caused by electrical burns.

Rapid repair of vascular injury is an important prognostic factor for electrical burns. This repair is achieved mainly via stromal cell-derived factor (SDF)-1α promoting the mobilization, chemotaxis, homing, and targeted differentiation of bone marrow mesenchymal stem cells (BMSCs) into endothelial cells. Forming a concentration gradient from the site of local damage in the circulation is essential to the role of SDF-1α. In a previous study, we developed reactive oxygen species (ROS)-sensitive PPADT nanoparticles containing SDF-1α that could degrade in response to high concentration of ROS in tissue lesions, achieving the goal of targeted SDF-1α release. In the current study, a rat vascular injury model of electrical burns was used to evaluate the effects of targeted release of SDF-1α using PPADT nanoparticles on the chemotaxis of BMSCs and the repair of vascular injury. Continuous exposure to 220 V for 6 s could damage rat vascular endothelial cells, strip off the inner layer, significantly elevate the local level of ROS, and decrease the level of SDF-1α. After injection of Cy5-labeled SDF-1α-PPADT nanoparticles, the distribution of Cy5 fluorescence suggested that SDF-1α was distributed primarily at the injury site, and the local SDF-1α levels increased significantly. Seven days after injury with nanoparticles injection, aggregation of exogenous green fluorescent protein-labeled BMSCs at the injury site was observed. Ten days after injury, the endothelial cell arrangement was better organized and continuous, with relatively intact vascular morphology and more blood vessels. These results showed that SDF-1α-PPADT nanoparticles targeted the SDF-1α release at the site of injury, directing BMSC chemotaxis and homing, thereby promoting vascular repair in response to electrical burns.

The caspase-1 inhibitor AC-YVAD-CMK attenuates acute gastric injury in mice: involvement of silencing NLRP3 inflammasome activities.

This study evaluated the protective effects of inhibiting caspase-1 activity or gastric acid secretion on acute gastric injury in mice. AC-YVAD-CMK, omeprazole, or vehicle were administered to mice before cold-restraint stress- or ethanol-induced gastric injury. Survival rates and histological evidence of gastric injury of mice pretreated with AC-YVAD-CMK or omeprazole, and exposed to cold-restraint stress, improved significantly relative to the vehicle group. The increased levels of tumour necrosis factor-α, interleukin (IL)-1ß, IL-6, and IL-18 following cold-stress injury were decreased by AC-YVAD-CMK, but not omeprazole, pretreatment. The increased expression of CD68 in gastric tissues was inhibited significantly by AC-YVAD-CMK pretreatment. Inhibiting caspase-1 activity in the NLRP3 inflammasome decreased gastric cell apoptosis, and the expression of Bax and cleaved caspase-3. AC-YVAD-CMK pretreatment significantly inhibited cold-restraint stress-induced increases in the expression of phosphorylated IκB-alpha and P38. General anatomy and histological results showed the protective effect of AC-YVAD-CMK on ethanol-induced acute gastric injury. Overall, our results showed that the caspase-1 inhibitor AC-YVAD-CMK protected against acute gastric injury in mice by affecting the NLRP3 inflammasome and attenuating inflammatory processes and apoptosis. This was similar to the mechanism associated with NF-κB and P38 mitogen-activated protein kinase signalling pathways.

Overexpression of Hypo-Phosphorylated IκBß at Ser313 Protects the Heart against Sepsis.

IκBßis an inhibitor of nuclear factor kappa B(NF-κB) and participates in the cardiac response to sepsis. However, the role of the hypo-phosphorylated form of IκBß at Ser313, which can be detected during sepsis, is unknown. Here, we examined the effects of IκBß with a mutation at Ser313→Ala313 on cardiac damage induced by sepsis. Transgenic (Tg) mice were generated to overexpress IκBß, in which Ser-313 is replaced with alanine ubiquitously, in order to mimic the hypo-phosphorylated form of IκBß. Survival analysis showed that Tg mice exhibited decreased inflammatory cytokine levels and decreased rates of mortality in comparison to wild type (WT) mice, after sepsis in a cecal-ligation and puncture model (CLP). Compared to WT septic mice, sepsis in Tg mice resulted in improved cardiac functions, lower levels of troponin I and decreased rates of cardiomyocyte apoptosis, compared to WT mice. The increased formation of autophagicvacuoles detected with electron microscopy demonstrated the enhancement of cardiac autophagy. This phenomenon was further confirmed by the differential expression of genes related to autophagy, such as LC3, Atg5, Beclin-1, and p62. The increased expression of Cathepsin L(Ctsl), a specific marker for mitochondrial stress response, may be associated with the beneficial effects of the hypo-phosphorylated form of IκBß. Our observations suggest that the hypo-phosphorylated form of IκBß at Ser313 is beneficial to the heart in sepsis through inhibition of apoptosisand enhancement of autophagy in mutated IκBß transgenic mice.

Use of Amniotic Microparticles Coated With Fibroblasts Overexpressing SDF-1α to Create an Environment Conducive to Neovascularization for Repair of Full-Thickness Skin Defects.

As angiogenesis and vasculogenesis involve the complex network structures of various types of cells, extracellular matrix components, and cytokines, it is still difficult to exactly mimic the microenvironment of vascularization in vivo. In our study, we constructed a complex containing highly proliferative fibroblasts that can secrete extracellular matrix components and growth factors to chemotaxize endothelial progenitor cells (EPCs) in an attempt to create an ideal microenvironment for quick vascularization. Amniotic membrane microparticles (mAM) rich in type IV collagen (COL IV) and laminin (LN) were prepared, and human dermal fibroblasts (HDF) were infected with lentivirus (LV) of overexpression of SDF-1α to construct SDF-1α(ov)HDF. Using the rotary cell culture system (RCCS), mAM was loaded with HDF or SDF-1α(ov)HDF to construct HDF-mAM and SDF-1α(ov)HDF-mAM complexes. The complexes were able to secrete various types of active peptides (IL-6, IL-8, TGF-ß, and bFGF) during in vitro culture. In addition, SDF-1α(ov)HDF-mAM complex highly expressed SDF-1α. Transwell assay showed SDF-1α(ov)HDF-mAM complex had an apparent chemotactic effect on EPCs. Transplantation of complexes onto full-thickness skin defects of C57BL mice further demonstrated that SDF-1α expression and the number of peripheral EPCs at days 3, 5, and 7 in the SDF-1α(ov)HDF-mAM group were significantly higher than that in other groups (p < 0.01). The local microvascular density at day 10 of transplantation showed that the microvascular density in the SDF-1α(ov)HDF-mAM group was significantly higher than that in HDF-mAM group (p < 0.01). In conclusion, HDF-mAM had a strong proliferative activity and could be used to create a sound microenvironment for quick vascularization by secreting multiple cytokines and extracellular matrix components. Overexpression of SDF-1α could chemotaxize EPCs to reach local wounds, thus further accelerating angiogenesis in the transplant site. The technique described may prove to be a new model for accelerating vascularization of tissue and organ transplants and chronic ischemic wounds.

Percutaneous transhepatic metal versus plastic biliary stent in treating malignant biliary obstruction: a multiple center investigation.

OBJECTIVE: To compare the efficacy of metal versus plastic biliary stent implantation in the treatment of malignant biliary obstruction. METHODS: Percutaneous transhepatic self-expandable metal stent (MS, n=61) and 10F plastic stent (PS, n=34) were placed in 95 patients with malignant biliary obstruction in three hospitals of Guangdong province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the survival of the patients and the rates of stent patency. RESULTS: The 30-day mortality rate was lower in the MS group (6/61, 9.8%) than in the PS group (9/34, 26.5%, P<0.05). The 30-day reobstruction rate and the complication rate were 15.0%, 16.4% in the MS group and 32.4%, 29.4% in the PS group, respectively (P<0.01). The median patency period of stents and median survival period of the patients were 230 days, 224 days in the MS group and 90 days, 94 days in the PS group, respectively (P<0.01). CONCLUSION: Metal stent is clinically superior to plastic stent in the treatment of malignant biliary obstruction.

[Comparative assessment of clinical efficacy of percutaneous transhepatic metal versus plastic biliary stent implantation for malignant biliary obstruction: a multi-centered investigation].

OBJECTIVE: To compare the clinical efficacy of metal versus plastic biliary stent implantation for treatment of malignant biliary obstruction. METHODS: Percutaneous transhepatic implantations of self-expandable metal stent (MS, n=61) or 10F plastic stent (PS, n=34) were performed in 95 patients with malignant biliary obstruction selected from 3 hospitals of Guangdong Province. All patients were followed up until death or at least one year after the procedure. Kaplan-Meier analysis was used to compare the patients' survival and stent patency rates. RESULTS: The 30-day mortality rate was lower in MS group (6/61, 9.8%) than in PS group (9/34, 26.5%, P<0.05). The 30-day reobstruction rate and incidence of complications were 15.0%, 16.4% in MS group and 32.4%, 29.4% in PS group, respectively (P<0.01). The median patency period of the stents and median survival period of the patients were 230 d, 224 d in MS group and 90 d, 94 d in PS group, respectively (P<0.01). CONCLUSION: Metal stent implantation is superior to plastic stent for treatment of malignant biliary obstruction.

[Advancement in the research of mechanism of endogenous cellular injury in visceral complications as complications after severe burn].

It is of great importance to know the endogenous mechanism in burn-induced organ injuries, not only for the understanding of pathophysiological processes after burn, but also for guiding the clinical treatment. Recent studies have widened and deepened our scope and understanding of secondary injuries to various organs. However, a unanimous understanding of molecular pathway involved in all burn-induced organ injuries has not been attained. Relatively, the mechanism of endogenous cellular injuries as a result of burn injury could be regarded as a common one to explain the causation of cellular injury, and to guide the prevention and treatment for the burn-induced complications using cytoprotection strategy. This review summarized four aspects of the mechanism of endogenous cellular injuries, including cellular injuries induced by ischemic/hypoxic-oxidative stress, excessive inflammatory factors released by inflammatory cells, immunosuppression caused by suppression of function of adaptive immune cells, and dysfunction of important supportive cells of various organs.

Vitamin D receptor genetic polymorphisms and tuberculosis among Chinese Han ethnic group.

BACKGROUND: In epidemiological studies, tuberculosis (TB) appears intimately with vitamin D insufficiency whereas its relationship with vitamin D receptor (VDR) polymorphism caused by radical difference remains unspecified. This study aimed to investigate the relationship between vitamin D genetic polymorphism and tuberculosis in Han ethnic group. METHODS: Meta-analysis was adopted in the synthetic quantitative analysis of documents home and abroad on the relationship between vitamin D genetic polymorphisms and tuberculosis, which were openly published during June 2000 to January 2010. Random effect model and fixed effect model analyses were used to calculate the incorporated odds ratio (OR) based on the heterogeneity test data. RESULTS: A total of 6 eligible studies were included in this analysis. The FokI-ff genotype showed a significant marginal association (Fixed effect model: OR 1.91, 95%CI 1.44-2.52; Random effect model: OR 1.91, 95%CI 0.94-3.88), yet TaqI polymorphisms was not significantly related to TB. CONCLUSION: The interaction between FoKI genotype polymorphism and TB observed demonstrates that vitamin D deficiency might exist as a risk factor during the development of TB in Han ethnic group and more evidences needed to validate the conclusion.

Pre-hospital emergency burn management in Shanghai: analysis of 1868 burn patients.

BACKGROUND: There are few studies reporting the level of pre-hospital emergency management of burn patients and related influencing factors in China. This study is a summary of our investigation on emergency education and people's awareness about pre-hospital emergency management of burn patients in Shanghai, China, and analyses key factors influencing pre-hospital emergency management of burn patients. METHODS: The survey was conducted by questionnaire in burn patients who sought initial clinical visits at the Burn Center of Changhai Hospital (Shanghai, China) between November 2009 and December 2010, including demographic data, burn conditions, pre-hospital emergency management and education about emergency burn management. Data were statistically treated by SPSS software. RESULTS: Altogether 1868 effective questionnaire forms were collected; 33.9% of these burn patients received cooling treatment before admission and 32.2% of them used 'folk remedies' or antibiotics to treat the wound surface. Only 12.2% of these burn patients had received education about the knowledge of emergency management, mainly through public media (38.2%), relatives and friends (24.6%), Internet (15.8%), workplace (11.4%) and schools (10.1%). The result of logistic regression analysis showed that emergency education, especially via Internet and workplace, played an important role in pre-hospital emergency management, and that different channels of emergency education affected different age groups of people: network and unit education mainly affected young adults, while relatives and friends mainly affected elderly people. In addition, educational level was an important factor favourably affecting 'cooling therapy'. CONCLUSIONS: The level of emergency burn management and related education is relatively low in China at present, and it is therefore necessary to intensify education about pre-hospital emergency management to raise the level of emergency burn management. At the same time, more attention should be paid to age- and population-specific education. Finally, universal emergency education should be included in the national basic education as a long-term strategy.

A new strategy of promoting vascularization of skin substitutes by capturing endothelial progenitor cells automatically.

How to promote vascularization of a skin substitute is the key to successful skin transplantation. Current methods are mainly through releasing angiogenesis-related factors (ARF) or seeding angiogenesis-related cells (ARC), but the efficacy of these methods is not satisfactory, because angiogenesis needs participation of multiple factors, extracellular matrix and related cells. The latest research has demonstrated that endothelial progenitor cells (EPCs) originating from bone marrow and existing in peripheral blood are the key element participating in revascularization of adult tissues. They directly participate in both stem cell vasculogenesis of ischemic tissues and local angiogenesis. We therefore hypothesize whether it is possible to construct a new skin substitute and use it to mobilize EPCs in bone marrow to peripheral circulation and capture EPCs automatically as a simple and effective method of promoting vascularization of the skin substitute for the sake of improving its post-transplant survival.

An epidermal stem cells niche microenvironment created by engineered human amniotic membrane.

How to amplify epidermal stem cells (ESCs) rapidly is a challenging crux in skin tissue engineering research. The present study describes the preparation of 3D micronized (300-600 µm) amniotic membrane (mAM) by means of repeated freeze-thawing cycles to deplete cell components and homogenized with a macrohomogenizer in liquid nitrogen. This newly prepared mAM not only possessed the characteristics of a microcarrier but completely retained the basement membrane structure and abundant active substances such as NGF, HGF, KGF, bFGF, TGF-ß1 and EGF in the AM matrix. The result showed that mAM combined with rotary cell culture system (RCCS) was able to amplify ESCs quickly. The relative cell viability at day 7 and 14 was significantly higher than that of the conventional 2D plate culture (326 ± 28% and 535 ± 47% versus 232 ± 21% and 307 ± 32%, P < 0.05). In addition, the new method was able to prevent cell differentiation effectively and retain the characteristics of stem cells. When mAM loaded with ESCs (ESC-mAM) was further transplanted to full-thickness skin defects in nude mice, ESCs survived well and formed a new epidermis. Four weeks after transplantation, papilla-like structures were observed, and collagen fibers were well and regularly arranged in the newly formed dermal layer. In conclusion, the mAM as a novel natural microcarrier possesses an intact basement membrane structure and bioactivities. It not only provides the microenvironment similar to the stem cell niche within the human body favorable for ex vivo culture and amplification of ESCs but can be used as the dermal scaffold in constructing a skin substitute containing ESCs for the repair of full-thickness skin defects.

[Effect of hydrogen-rich saline on blood pressure and antioxidant ability of lung tissue in scalded rats following delayed resuscitation].

OBJECTIVE: To study the effect of hydrogen-rich saline on blood pressure and antioxidant ability of lung tissue in scalded rats following delayed resuscitation. METHODS: The hydrogen-rich saline was prepared (hydrogen-saturated normal saline with hydrogen concentration of 0.6 mmol/L). Twenty SD rats were divided into hydrogen-rich saline group (HS) and normal saline group (NS) according to the random number table, with 10 rats in each group. All the rats were subjected to 30% total body surface area (TBSA) full-thickness scald. Rats in HS and NS groups were infused with hydrogen-rich saline or normal saline with one half of the total fluid replacement volume as calculated according to the Parkland formula (4 mL×kg(-1)×%TBSA(-1)) at post scald hour (PSH) 7 and one-quarter of the volume at PSH 9 and 17 respectively. The general condition of rats during the experiment was observed. The systolic pressure of rats was measured at PSH 6 and 24. All rats were sacrificed at PSH 24 to collect lung tissue for detecting superoxide dismutase (SOD) inhibition ratio and malondialdehyde (MDA) level. Data were processed with t test. RESULTS: All rats survived through the experiment. The systolic pressure of rats in HS group and NS group was respectively (87 ± 4) mm Hg (1 mm Hg = 0.133 kPa) and (86 ± 5) mm Hg at PSH 6, and the values were close (t = 0.213, P = 0.834); however the systolic pressure at 24 h was higher in HS group than in NS group [(124 ± 7) mm Hg vs. (115 ± 6) mm Hg, t = 2.958, P = 0.008]. SOD inhibition ratio of lung tissue in HS group [(0.465 ± 0.014)%] was higher than that in NS group [(0.358 ± 0.021)%, t = 11.767, P = 0.000]. MDA level of lung tissue in HS group [(922 ± 196) pmol/mg] was lower than that in NS group [(1118 ± 212) pmol/mg, t = -2.142, P = 0.046]. CONCLUSIONS: Delayed resuscitation for scalded rats with hydrogen-rich saline is helpful in the recovery of systolic pressure, and it can ameliorate lung tissue injury caused by reperfusion through enhancing the effect of antioxidase.