Prognosis analysis of multi-indicator combined with sequential organ failure assessment in patients with sepsis / 中华危重病急救医学

OBJECTIVE@#To explore the prognostic value of early multiple detection indicators in combination with sequential organ failure assessment (SOFA) in sepsis patients.@*METHODS@#A retrospective analysis was conducted. Patients with sepsis admitted to the department of critical care medicine of Huanggang Central Hospital of Yangtze University from May 2020 to May 2022 were selected as the research subjects. Coagulation indicators, inflammatory factors, blood routine, liver and kidney function, and blood gas analysis were collected at admission. Organ dysfunction was assessed based on the SOFA score within 24 hours after admission. Patients were divided into a survival group and a death group according to the outcome of 28 days in ICU. Differences in the above indicators between the two groups were compared. Multifactorial Logistic regression analysis was used to analyze prognostic factors of 28-day mortality in sepsis patients. Receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive performance of various indicators, the SOFA score, and the combine model for the 28-day outcome in patients with sepsis.@*RESULTS@#A total of 101 patients with sepsis were enrolled, 56 patients survived and 45 patients died. Compared to the survival group, patients in the death group were older, the proportion of patients with septic shock was larger, the SOFA score, and the proportion of pulmonary infection were higher, the prothrombin time (PT) and activated partial thromboplastin time (APTT) were significantly prolonged, the prothrombin activity (PTA) was significantly shortened, and antithrombin (AT) was significantly decreased, the levels of hypersensitivity C-reactive protein (hs-CRP), blood urea nitrogen (BUN), total bilirubin (TBil), and lactic acid (Lac) were significantly increased, while the platelet count (PLT) was significantly decreased. Multifactorial Logistic regression analysis showed that pulmonary infection [odds ratio (OR) = 0.010, 95% confidence interval (95%CI) was 0.001-0.164, P = 0.001], AT (OR = 0.944, 95%CI was 0.910-0.978, P = 0.002), hs-CRP (OR = 1.008, 95%CI was 1.001-1.015, P = 0.017), Lac (OR = 1.619, 95%CI was 1.195-2.193, P = 0.002), and SOFA score (OR = 1.363, 95%CI was 1.076-1.727, P = 0.010) were independent prognostic factors for 28-day mortality in patients. A combined model was constructed using pulmonary infection, AT, hs-CRP, Lac, and SOFA score. ROC curve analysis showed that the area under the ROC curve (AUC) for the combine model in predicting sepsis prognosis was 0.936 (95%CI was 0.869-0.975, P < 0.001), which was higher in value compared to single indicators (AUC of AT, hs-CRP, Lac, and SOFA score were 0.775, 0.666, 0.802, 0.796, respectively, all P < 0.05).@*CONCLUSIONS@#The predictive ability of the SOFA score for sepsis patient outcomes is limited. The combine model combining infection site, AT, hs-CRP, and Lac shows better predictive ability.

Whole Genome Analyses of Chinese Population and De Novo Assembly of A Northern Han Genome / 基因组蛋白质组与生物信息学报·英文版

To unravel the genetic mechanisms of disease and physiological traits, it requires comprehensive sequencing analysis of large sample size in Chinese populations. Here, we report the primary results of the Chinese Academy of Sciences Precision Medicine Initiative (CASPMI) project launched by the Chinese Academy of Sciences, including the de novo assembly of a northern Han reference genome (NH1.0) and whole genome analyses of 597 healthy people coming from most areas in China. Given the two existing reference genomes for Han Chinese (YH and HX1) were both from the south, we constructed NH1.0, a new reference genome from a northern individual, by combining the sequencing strategies of PacBio, 10× Genomics, and Bionano mapping. Using this integrated approach, we obtained an N50 scaffold size of 46.63 Mb for the NH1.0 genome and performed a comparative genome analysis of NH1.0 with YH and HX1. In order to generate a genomic variation map of Chinese populations, we performed the whole-genome sequencing of 597 participants and identified 24.85 million (M) single nucleotide variants (SNVs), 3.85 M small indels, and 106,382 structural variations. In the association analysis with collected phenotypes, we found that the T allele of rs1549293 in KAT8 significantly correlated with the waist circumference in northern Han males. Moreover, significant genetic diversity in MTHFR, TCN2, FADS1, and FADS2, which associate with circulating folate, vitamin B12, or lipid metabolism, was observed between northerners and southerners. Especially, for the homocysteine-increasing allele of rs1801133 (MTHFR 677T), we hypothesize that there exists a "comfort" zone for a high frequency of 677T between latitudes of 35-45 degree North. Taken together, our results provide a high-quality northern Han reference genome and novel population-specific data sets of genetic variants for use in the personalized and precision medicine.

Construction and characterization of △sseK2 mutant strain of Salmonella typhimurium SL1344 / 中华微生物学和免疫学杂志

Objective To analyze the biological characteristics of a mutant strain of Salmonella ty-phimurium SL1344 with sseK2-deletion (SL1344△sseK2) in order to provide reference for further study of safe and effective live vaccines. Methods The mutant strain SL1344△sseK2 with a deletion of 1047 bp in sseK2 gene was constructed through a two-step allelic exchange using recombinant suicide plasmid. Its com-plemented strain, SL1344C△sseK2, was also constructed. Biological and immunological characteristics of the mutant strain were detected. Results PCR, double-enzyme digestion and sequencing analysis showed that the mutant strain SL1344△sseK2 and the complemented strain SL1344C△sseK2 were successfully con-structed. The serotype of the mutant strain was 1,4,[5],12:i:1,2, identical to the parent strain SL1344. In addition, the mutant strain showed no significant change in biochemical characteristics or growth rate and was genetically stable in vitro. Compared with the parent strain SL1344, the virulence of SL1344△sseK2 was attenuated in BALB/ c mice. The median lethal dose of SL1344△sseK2 for 6-week-old BALB/ c mice was 3. 44×108 colony-forming units (CFU), which was 1620 times lower than that of SL1344. Oral immuniza-tion with SL1344△sseK2 protected 62. 5％ of the mice against challenge with wild Salmonella typhimurium strains on 17 d after vaccination. The levels of serum IgG antibody peaked on 14 d after immunization. No significant difference in biological characteristics was observed between the complemented and the parent strains, indicating that the mutant strain was basically complemented to the wild-type strain.Conclusions The mutant strain SL1344△sseK2 was constructed successfully and genetically stable with sig-nificantly attenuated virulence and good immunogenicity. This study suggested that sseK2 gene played an im-portant role in regulating the virulence of SL1344, which might provide reference for further study of its func-tion and for assessing its potential as a candidate live attenuated vaccine.

Sequence analysis, prokaryotic expression and purification of Salmonella typhimurium Ssek3 protein / 中华微生物学和免疫学杂志

Objective To study the sequence structure of Salmonella typhimurium Ssek3 gene and to express it at protein level in a prokaryotic expression system .Methods Sequence of Ssek3 gene was ob-tained from Salmonella typhimurium SL1344 strain.Bioinformatics methods were used for systematic analy-sis .A prokaryotic expression system for expressing Sse3k gene was constructed and the expressed protein was purified by Ni-NTA affinity chromatography .Results Sequence analysis showed that the Ssek3 gene of Sal-monella typhimurium was 1008 bp in length, encoding a protein of 335 amino acids and 72 amino acid resi-dues.The molecular weight, molecular formula and isoelectric point of Ssek3 protein was 37.89×103, C1700 H2629 N463 O497 S12 and 6.7, which indicated that it was a stable and hydrophilic protein .Ssek3 protein was a membrane protein without signal peptide or transmembrane region , containing five N-glycosylation sites , three O-glycosylation sites , 33 phosphorylation sites , 22 linear B-cell epitopes , 11 T-cell epitopes and 21 di-sulfide bonds.The secondary structure of Ssek3 protein contained 114 α-helices (Hh) (34.03％), 72 ex-tended chain (Ee) (21.49％), 30β-sheets (Tt) (8.96％) and 119 random coils (Cc) (35.52％).Re-sults of SDS-PAGE showed that the fusion protein Ssek 3 expressed in the prokaryotic expression system was a secretory protein with a molecular weight of about 40×103 .Conclusion The Ssek3 gene of Salmonella typh-imurium is successfully cloned , sequenced and expressed in this study , which will lay a foundation for fur-ther studying the role of Ssek3 protein in host cells during Salmonella typhimurium infection.

Experimental study on the effect of VIP on MVD in the process of fracture healing in rats with high selectiveneurotomy / 医学研究生学报

Objective The mechanism and signaling mechanisms of fracture healing by vasoactive intestinal peptide (VIP) regulating are not clear.We established an selective cut off sensory/motor nerve combined with tibial fracture rat model to study the effects of VIP and microvessel density(MVD) during the fracture healing process after nerve injury.Methods 60 SD rats were randomly divided into 3 groups: tibial fracture + motor nerve (anterior root) cutting group (group ART);tibial fracture + posterior root (sensory nerve) cutting group (group PRT);tibial fracture group (group SO),and each group were 20.Three groups of rats in the model after the establishment of 1W, 2W, 3W, 4W these time points, were killed.The skeleton specimens were obtained in the vicinity of the fracture 5mm, to observe the expression of VIP and microvessel density of the law of change.Results Histology observation showed: new bone trabecular bone callus maturity of PRT group is lower than SO group and ART group at each time points;the immunohistochemical staining showed that compared with callus VIP average optical density of PRT group at 2w and 3w(0.156±0.015、0.163±0.012), SO group(0.216±0.012、0.223±0.010) and ART group(0.198±0.014、0.212±0.016) increased obviously(P<0.05).The detection of callus MVD indicated that compared with callus MVD average density of PRT group at 2w and 3w(26.4±2.2、32.3±2.0), SO group(38.2±2.3、40.6±2.6) and ART group(36.6±2.2、38.5±2.1) significant increased (P<0.05).At the 2nd, 3rd and 4th week, the wet weight of tibia was significantly increased in group ART and SO compared with group PRT(P<0.05),which increased more significantly at 2 weeks.Conclusion The effect of loss of sensory nerve innervation on the formation of microvessel density, callus maturity and fracture healing rate were more pronounced than loss of motor nerve innervation.

Clinical application and effect of pick-stab skill in eyebrow embroidery / 中华医学美学美容杂志

Objective To investigate the clinical application and effect of pick-stab skill in eyebrow embroidery.Methods From July 2015 to January 2016,36 cases were selected to receive eyebrow embroidery with pick-stab skill in our department,including 1 male and 35 females.The cosmetic outcomes,complications and satisfaction rate were observed in these cases.Results In these 36 cases,14 cases were colored in one time,19 cases were colored twice,and 3 cases were more than 3 times.All patients were followed up for 6 months.The color of the eyebrow was natural,and the blue color was not existed.Conclusions The pick-stab skill in eyebrow embroidery is worthy in clinic with better cosmetic effect,higher success rate and safety.

Characterization of a Salmonella typhimurium SL1344 cya mutant strain / 中国免疫学杂志

Objective:To explore the function of the cya gene and the preliminary mechanism of attenuated strain.Methods:The biological characteristics of cya mutant in acid and alkali resistant,salt resistance,motility,biofilm components,poisonous to the cells of epithelial cell adhesion,invasion were analysis.Results:The mobility capabilities,acid and alkali resistance and salt tolerance of cya mutant were significantly lower than the parent strain;the composition testing revealed that the cya mutant did not produce cellulose,curli and biofilm;at the same time the adhesion and invasion to epithelial cells of cya mutant had a prominent depression,and the toxicity to HeLa cells was weaker than the parent strain.Conclusion:The function of cya gene is closely related to athletic ability, penetration of cell membrane, the formation biofilm and virulence.It will provide a theory reference to the functional research of Salmonella typhimurium cya gene and the mechanism of attenuated strain.This will contribute to the development of oral vaccine using attenuated Salmonella typhimurium as vector.

Influence of attachment type on stress distribution of implant-supported removable partial dentures / 北京大学学报(医学版)

Objective: To compare influences of different retention attachments on stress among supporting structures .Methods: By 3-dimensional laser scanner and reverse engineering computer aided design ( CAD) software , a basic partially edentulous digital model with mandibular premolar and molar missing was established .Implant attachment and removable partial dentures ( RPD) were added into the basic model to build three kinds of models: RPD only, RPD +implant +Locator attachment , and RPD +implant +Magfit attachment .Vertical and inclined loads were put on artificial teeth unilaterally . By means of 3-dimensional finite element analysis , the stress distribution and displacement of the main supportive structures were compared . Results: A complete 3-dimensional finite element model was established , which contained tooth structure , and periodontal structures .The displacement of the denture was smaller in Locator (9.38μm vertically, 45.48μm obliquely) and Magfit models (9.54μm vertically, 39.45 μm obliquely) compared with non-implant RPD model (95.27 μm vertically, 155.70 μm oblique-ly) .Compared with the two different attachments , cortical bone stress value was higher in Locator model ( Locator model 10.850 MPa vertically , 43.760 MPa obliquely;Magfit model 7.100 MPa vertically , 19.260 MPa obliquely).The stress value of abutment periodontal ligamentin Magfit model (0.420 MPa vertically) was lower than that in Locator model (0.520 MPa vertically).Conclusion:The existence of implant could reduce maximum von Mises value of each supportive structure when Kennedy Ⅰpartially edentulous mandible was restored .Comparing the structure of Magfit and Locator attachment , the contact of Magfit attachment was rigid , while Locator was resilient .Locator attachment could improve stability of the denture dramatical -ly.Locator had stronger effect on defending horizontal movement of the denture .

Scalded Skin of Rat Treated by Using Fibrin Glue Combined with Allogeneic Bone Marrow Mesenchymal Stem Cells

BACKGROUND: It is difficult to achieve satisfactory results with the traditional treatment of large-area skin defects and deep burns. OBJECTIVE: To test the treatment effect of an active dressing film made of a mixture of fibrin glue and bone marrow mesenchymal stem cells (BMSCs) for repairing burn wounds on the skin of rats. METHODS: Two scald wounds were made on the back of each rat. A total of 30 scald wounds were randomly divided into 3 groups, with 10 wounds in each group. In the experimental treatment group, the scald wounds were covered with the fibrin glue and BMSC mixture. The wounds of the experimental control group were covered with fibrin glue only. No intervention was administered to the blank control group. Thirty days after treatment, pathological sections were cut from the scalded local tissues of all rats from the 3 groups and observed with a microscope. RESULTS: The speed of scald wound healing in the experimental treatment group was faster than the other 2 groups. In the experimental treatment group, histopathological analysis revealed that the sebaceous glands showed obviously proliferous at the edge of the new tissue and gradually extended to the deep dermal layer of the new tissue. CONCLUSION: BMSCs may have an active role in promoting skin tissue repair and generating skin appendages. Allogeneic BMSCs mixed with fibrin glue can contribute to the quick formation of a film-like gel over the scald wounds, which might be of significance for emergency treatment and skin-grafting operations.

Comparison of stilbene synthase from different plant sources for resveratrol biosynthesis / 生物工程学报

Resveratrol is a natural phytoalexin with special pharmacological and health functions. Stilbene synthase (STS) is a key and rate-limiting enzyme in the biosynthesis of resveratrol that is present only in a limited number of plants. The content of resveratrol from Polygonum cuspidatum is more than 1000 times higher than grapes and peanuts. We speculate that the catalytic ability of different STS may be one of the reasons causing differences in the content of resveratrol. To verify the above speculation, Vitis vinifera stilbene synthase gene (VvSTS) was amplified according to overlap PCR protocol with genomic DNA as template. VvSTS and PcSTS (PcPKS5) were analyzed through heterologous expression in Escherichia coli. The expression products were purified with Ni-NTA sepharose affinity chromatography and desalted through PD-10 column. The molecular weight of the two fusion proteins was about 43 kDa. Enzyme reaction and product analysis showed that the two products were resveratrol. The enzyme kinetic analysis showed that the catalyze efficiency (Kcat/Km) of PcPKS5 was 2.4 times of the VvSTS. Our findings confirms that STS from certain plants has much higher catalytic capability.

Modified purse-string suture in closure of skin defects: scar minimization and tension adjustment / 中华医学美学美容杂志

Objective To explore the effect of intraoperative tension adjustment and postoperative scar formation in the treatment of circular skin defects using modified purse-string suture.Methods Twenty-eight cases of circular lesions in the face region were selected and resected along the edge.We first used purse-string suture technique to reduce the circular defect area,and then closed the wound with linear suture in random direction.After 7 days,the stitches were removed and longterm follow-up effects were observed.Results All patients had no facial organ deformation and displacement,the length of the linear scar lesions was shorter than the preoperative length.In 28 cases,one patient's surgical wound was dehisced after removal of stitches in 24 h,and the rest of the skin defects healed after operation in stage Ⅰ.All cases were followed up for 3 months to 1 year,and had a satisfactory therapeutic effect.Conclusions Modified purse-string suture can linearly close the dicision in stage Ⅰ,reduce the scar area and maintain the normal morphology and relative position of the nearby organs.

Effect of different-dose botulinum toxin A intradermal injection on axillary hyperhidrosis / 中华医学美学美容杂志

Objective To evaluate the long-term effectiveness of different-dose of botulinum toxin A (BTXA) therapy on axillary hyperhidrosis.Methods Total 86 patients with axillary hyperhidrosis were self-controlled.One group of left axillary was injected with a low-dose of BTXA,50U.Another group of right axillary was injected with a high-dose of BTXA.A total dose of 200 U of BTXA was used per axilla.Patients were followed-up for 29 months.To investigate the effect of two methods,we analyzed two ranked data by rank sum test and x2 test to judge the disparities of the therapeutic effect.Results The results showed that the relapse-free interval of two groups with axillary hyperhidrosis was significant difference through the statistical analysis (P ＜ 0.05).Conclusions High-dose of BTXA treatment is capable of prolonging the antihidrotic effect on axillary hyperhidrosis.

Silk/poly(lactic-co-glycolic acid) scaffold degradation fluid and proliferation of bone marrow mesenchymal stem cells / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.25.016

The establishment of the three-dimensional culture model of the human skin squamous-celled carcinoma and their biological evaluation of the high-invasive squamous carcinoma cells / 重庆医学

Objective To establish the three-dimensional culture model of the human skin squamous-celled carcinoma ,and isolate the highly invasive cell subsets ,and compare their biological characteristics .Methods By using the composite chitosan tissue engi-neering skin ,the three-dimensional culture model of the human skin squamous-celled carcinoma was successfully established , through digestion ,we divided and got the high-invasive squamous carcinoma cells subsets .After that ,the different invasive proper-ties of subpopulations of cells in nude mice tumor effects were compared .Results Different concentrations of cinnamaldehyde and interferon on skin squamous-celled carcinoma cell proliferation inhibition had statistical significance (P<0 .01) ,the different invasive characteristics of skin squamous cells carcinoma between subpopulations of cells proliferation inhibition also was statistically signifi-cant(P<0 .01) ,and the two different invasive properties of subpopulations of cells in the tumor characteristics also had statistical significance(P<0 .01) .Conclusion We established the three-dimensional culture model of the human skin squamous-celled carcino-ma successfully ,by using this model ,we could screen the higher invasive cells subsets .

Sturge-Weber Syndrome

Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome, characterized by the association of facial port-wine hemangiomas in the trigeminal nerve distribution area, with vascular malformation(s) of the brain (leptomeningeal angioma) with or without glaucoma. Herein, we reported Sturge-Weber syndrome in a 50-year-old man, who presented port-wine hemangiomas and epilepsy. In this case, the patient's epilepsy episodes from his first year of life had been ignored and separated from the entity of SWS by his physicians, which led to delayed treatment. This case illustrates the importance of careful examination of patients of any age with hemangiomas in the trigeminal nerve with concomitant episodes of epilepsy. In such cases, there should be yearly neuroimaging screenings to guaranteed early interdisciplinary interventions from the time of definite diagnosis.

Effect of hepatocyte growth factor on the migration and apoptosis of,as well as p-Akt expression in cultured human eccrine sweat gland epithelial cells / 中华皮肤科杂志

Objective To investigate the effect of hepatocyte growth factor (HGF) on migration and apoptosis of,as well as phosphorylated-Akt (p-Akt) expression in cultured human eccrine sweat gland epithehal cells (hESGc).Methods The first generation of hESGc were cultured in keratinocyte serum free medium (KSFM) and treated with various concentrations (2,20,40μg/L) of HGF for different durations.Then,cell scratch test was performed to detect cell migration,a double staining flow cytometry assay using annexin VFITC/propidium iodide to detect cell apoptosis.and Western blot to measure the expression of p-Akt.Results HGF of 2μg/L had no effect on the migration of hESGc,while that of 20 μg/L and 40μg/L could promote the migration of hESGc by 33.2% and 228.2%.respectively.The average number of cells migrating into the scrach zone was significantly lower in untreated cell group than that in 20 and 40μg/L HGF-treated cell group (17.3±5.5 vs 23.0±6.3 and 56.7±7.9,t=2.653, 15.858,P<0.05,0.01, respectively).The apoptosis rate was 14.76% in untreated cells,14.16%,13.5% and 8.87% in cells treated with HGF of 2,20 and 40μ/L, respectively;there was a significant difference between untreated cells and 40μg/L HGF-treated cells (t=7.852,P<0.01).HGF could activate the phosphorylation of Akt protein and increase the expression of p-Akt.Conclusion HGF could promote the migration of,inhibit the apoptosis of,and stimulate the p-Akt expression in.hESGc.

Preparation of chitosan sustained release microspheres encapsulated with transforming growth factor beta 1 / 中国组织工程研究

OBJECTIVE: To prepare chitosan microspheres encapsulated transforming growth factor β1 (TGFβ1), and to analyze its property. METHODS: The chitosan was dissolved in 2% acetic acid to prepare chitosan microspheres encapsulated TGFβ1 with emulsification cross-linking method, Tween 80 and sodium polyphosphate were served as emulsifying agent and cross-linking agent, respectively. Meanwhile, chitosan microspheres and containing bovine serum albumin chitosan microspheres were prepared as blank control and experimental control groups. The morphology and diameter of 3 kinds of microspheres were observed, and the dispersion and in vitro release of chitosan microspheres encapsulated TGFβ1 were detected, furthermore, the water absorption expansion rate of blank control and experimental control groups were measured. RESULTS: Scanning electron microscopy showed that the microspheres diameter in the blank group was approach 15 μm, with smooth surface and plenty of tiny pores. However, the microspheres in the other 2 groups were distributed uniformly with approximately 1 μm in diameter, the surface was smooth. The chitosan microspheres encapsulated TGFβ1 released fast at begin 12 hours, and then gentled gradually, with 53.5% release ratio within 6 days. The increased mass of microspheres in the blank control and experimental control groups reached a balance after 1 hour, both of which were over 700%,in particular larger in the acid environment. CONCLUSION: Chitosan microspheres encapsulated TGFβ1 prepared by emulsification cross-linking method exhibit high yield and good drug release. The strong water absorption expansion rate of chitosan microspheres requires aperture size, as well as intensity of bone tissue engineered scaffold.

Three-dimensional degradable porous scaffolds made by silk fibroin-chitosan composite / 中国组织工程研究

BACKGROUND: Simply used natural materials-prepared scaffolds such as collagen, gelatin and fibrin solve problems of biocompatibility, but its degradation is rapid, and cannot induce new tissues, but collapse is found as cell scaffolds.OBJECTIVE: To explore and determine the property of biological degradable three-dimensional porous scaffolds using silk fibroin-chitosan composite.DESIGN, TIME AND SETTING: The material observational study was performed at the Institute of Bioengineering, Zhejiang Academy of Medical Science from June 2008 to June 2009.MATERIALS: Spring silk cocoon was presented by a silkworm farmer from Huangdunmiao village, Maqiao town, Haining City,Zhejiang Province, China. Chitosan was produced by Shanghai Bo'ao Biological Technology.METHODS: 15 g/L silk fibroin solution was made by degumming, salvation and dialysis. Chitosan was dissolved in 2% acetic acid solution to prepare 25 g/L chitosan-acetic acid solution. Two solutions were mixed to prepare six silk fibroin/chitosan solutions, and mass ratio was 10: 0, 5: 5, 4: 6, 3: 7, 2: 8, 0:10. These solutions were separately sucked in a 24-well plate. Following exhausting gas vacuole at 4 ℃, precooling was performed at -20 ℃ for 12 hours, followed by cryodesiccate for 30 hours. Samples were then hydrated in ethanol, neutralized in NaOH-alcohol for 1 hour, washed and then frozen to dry.MAIN OUTCOME MEASURES: Optical microscope and scanning electron microscope were used to observe pore size and structure of various mass ratio-prepared scaffold. Modified liquid substitution method was utilized to measure porosity of various scaffolds. The degradable rate of various scaffolds was determined at 4 weeks in vitro.RESULTS: Silk fibroin/chitosan of 10: 0 mass ratio-prepared scaffold had rough fluffy pore, was brittle, with high dissolve-loss rates. On the contrary, chitosan-prepared scaffold was hard, without enough elasticity following freeze-dry. The composite scaffold of 5: 5, 4: 6, 3: 7 and 2: 8 following freeze-dry was loose and soft, similar to sponge. With increased chitosan concentration,scaffold hardness increased. There were evenly distributed, detailed eyelets on the scaffold. Under the optical microscope,various pores were irregular; each pore closely connected and linked together; pore size was even, 20-100 μm. With increased chitosan concentration, pore size was gradually reduced. Scaffold porosity determination results displayed that mass ratio of silk fibroin/chitosan 4: 6 group > 5: 5 group > 3: 7 group > 2: 8 group. Compared with 2: 8 group, the porosity was significantly increased in the 5: 5 and 4: 6 groups (P < 0.05). No significant difference was detected in volume expansibility in the silk fibroin/chitosan composite scaffold of various mass ratios (P > 0.05). The degradation was slowest in the 2: 8 group, and fastest in the 5: 5 group at 4 weeks.CONCLUSION: Regarding physical and chemical properties, composite scaffold made by silk fibroin/chitosan showed significant superiority compared with scaffold made by silk fibroin or chitosan alone. Of them, silk fibroin/chitosan mass ratio of 5: 5 and 4: 6 are accorded with the requirement of cartilage tissue engineering.

Effect of engineered heterogeneous skins cells on phenotypes of langerhans cells / 中国免疫学杂志

Objective:To study the effect of seeding cells of tissue-engineered skins,keratinocytes and fibroblasts,on the phenotypes of langerhans cells (LC).Methods:Peripheral blood mononuclear cells were induced by cytokines,granulocyte macrophage-colony stimulating factor (GM-CSF),interleukin 4 (IL-4),transforming growth factor β1 (TGF-β1) to generate LCs,which were subsequently cocultured with allogenic keratinocytes or fibroblasts.Then the phenotypes of langerhans cells was detected by flow cytometer (FCM),and the degree of proliferation of autogeneic lymphocytes was assessed after stimulation with LCs.Results:Cultured LCs had low level expression of HLA-DR,CD80,CD86 and no expression of CD83.Cocultured with allogenic keratinocytes or fibroblasts,phenotypes of LCs did not change significantly.Simultaneously,LCs could not stimulate autogeneic lymphocytes proliferation.Conclusion:These data indicate that LCs cocultured with seeding cells of tissue-engineered skins remain immature state.It is suggested that seeding cells of tissue-engineered skins have low immunogenicity and are unable to induce significant immunological rejection of host after transplantation.

Effect of Wnt-3a signaling on aggregative growth of dermal papilla cells:a pilot study / 中华皮肤科杂志

Objective To investigate the influence of Wnt-3a signaling on aggregative growth of dermal papilla cells.Methods Recombinant adenovirus pAdEasy-1/Wnt-3a was constructed at first,and used to transfect cultured dermal papilla cells(DPCs).Then,the growth pattem of DPCs was observed by inverse microscopy;laser confocal microscopy and Western blot were utilized to detect the expressions of Wnt-3a,β-catenin and versican in low-passage DPCs,high-passage DPCs and transfected high-passage DPCs.Results The over-expression of Wnt-3a protein could effectively induce the aggregative growth of DPCs.Laser confocal microscopy showed that the fluorescence intensity of β-catenin and versican increased from 34.16±9.62 and 18.81±9.59 in high-passage DPCs to 87.35±17.28 and 92.18±18.39 in transfected high-passage DPCs(t=11.98,17.88,both P＜0.0 1),respectively.Also,Western blot proved a significant increase of expression intensity of β-catenin(15.27±2.17 vs 60.09±7.24,t=10.10,P＜0.01)and versican(19.32±2.46 vs 58.46±2.78,t=20.63,P＜0.01)in transfected high-passage DPCs compared with untransfected high-passage DPCS.ConclusionsWnt-3a signaling plays an important role in modulating aggregative growth of DPCs,which is mainly through the classical pathway with β-catenin as the key protein.As an important downstream gene of Wnt signaling,vesican is an indispensable part for the modulation of aggregative growth of DPCs.