BACKGROUND:Tissue engineering is an interdisciplinary field and its experimental safety covers a wide scope along with the increase in accidents of tissue engineering laboratories, the safety management in tissue engineering laboratories in universities has become an important public health problem. OBJECTIVE:To enhance the safety management strategies for tissue engineering laboratories in chinese universities and improve the safety management system. METHODS:PubMed, Elseveir, WanFang and CNKI databases were retrieved for the literatures concerning the biosafety, safety management of hazardous chemicals, waste, medical information, instrument operation and human body mechanics in tissue engineering laboratories, and then the status of laboratory management was analyzed. RESULTS AND CONCLUSION:The status of safety management in tissue engineering laboratories in China is analyzed based on the technique characters and regulations on safety management. Management strategies for laboratory safety have been proposed according to the differences in relevant laboratory safety management between China and the US, such as regular training on laboratory safety, improving the safety consciousness of experimental staff, constructing the strict system access to laboratory, improving safety facilities, standardizing the experimental safety manual and appointing specialized safety management committee. Comprehensive and systematical regulations on laboratory safety management will ensure the smooth running of tissue engineering laboratories in universities, thus accelerating the development of tissue engineering.

Objective To explore the endoscopic features and careinoembryonic antigen (CEA) ex-pressions of colorectal serrated adenomas (SA). Methods From June 2005 to July 2008, 27 patients with colorectal polyps and 26 cases of advanced colorectal cancer (ACC) were enrolled in the study. The pit pat-tern of the suspected lesions were observed with 0. 4% indigo carmine sodium stain and classified according to Kudo classification. The polyps were removed by biopsy, high-frequency electrical excision or endoscopic mucosa resection and the samples of ACC were collected with biopsy forceps. All specimens underwent rou-tine pathological examination and CEA expression was detected by immunohistochemistry. Results There were 47 SAs and 27 other types of polyps in polyp group. Most SAs located in left-side colon and were char-acterized by the bulge semipedunculation. The diameters of 45 serrated adenomas ranged from 3 to 8ram, and the maximal diameter of other 2 were more than 10ram. The most common type of pit pattern in SA was mixed type Ⅱ and ⅢL, with type Ⅱ predominant in a certain percentage. Expression of CEA in SA glands was significantly higher than that in proliferative polyps (P < 0. O1). Candnsion SA is an unique type of colorectal adenoma, which is capable of expressing CEA, and displays malignant potential and deserves great attention.

Three-dimensionally controlled cell-assembly technique makes fabricating tissues and organs in vitro to be possible. However, for real tissues and organs with complex structure and various cells, fabricating tissues and organs in vitro need a technique that could assemble and locate multi cells and materials precisely in the space. Facing the needs of multi-cell assembly, we designed a mixer nozzle and the matching pulse switching circuit which based on the single-nozzle cell assembly system, and developed a multi-cell-assembly system. We also carried out some assembly experiments with this system using materials that were similar to the multi-component extracellular matrix materials. The results demonstrated that the system could assemble various cells and materials into three-dimensional inhomogeneous structures precisely.
Bioartificial Organs ; Cell Culture Techniques ; instrumentation ; Cell Physiological Phenomena ; Equipment Design ; methods ; Extracellular Matrix ; chemistry ; Humans ; Tissue Engineering ; methods

Objective: To study the relationship between platelet activation and the degree of bleeding in patients with primary immune thrombocytopenia (ITP) . Methods: 43 patients with ITP were assessed based on ITP-BAT bleeding grading system. Platelet membrane glycoproteins (GP) Ⅰb, GPⅡb/Ⅲa and P-selectin expression were detected by flow cytometry analysis with and without adenosine diphosphate (ADP) stimulation. Association of platelet activation with platelet count, immature platelet fraction (IPF) , bleeding severity were evaluated. Results: GPⅡb/Ⅲa and P-selection expressions on unstimulated platelet in ITP patients were higher than those in healthy controls (65.69±10.73 vs 7.16±0.99, t=4.130, P<0.001; 15.43±1.41 vs 12.55±1.03, t=2.070, P=0.043, respectively) , and GPⅠb expression was lower than that in healthy controls (240.11±24.93 vs 295.11±22.15, t=2.417, P=0.020) . Comparatively to healthy individuals, following ADP stimulation, GPⅡb/Ⅲa expression in ITP patients increased (133.96±12.17 vs 39.67±4.99, t=5.256, P<0.001) , whereas GPⅠb and P-selection expressions decreased (37.09±3.94 vs 109.77±23.66, t=3.901, P<0.001; 149.06±19.14 vs 205.73±21.00, t=2.070, P=0.043, respectively) . ADP-stimulated GPⅠb, ADP-stimulated and unstimulated P-selection, proportion of GPⅠb, P-selection levels with/without ADP stimulation were significantly associated with platelet counts (P<0.05) . ADP-stimulated P-selection and proportion of P-selection levels with/without ADP stimulation were significantly associated with IPF (P<0.05) . There were significant differences in the expressions of unstimulated P-selection, ADP-stimulated P-selection, ADP-stimulated GPⅠb stratified by bleeding grades (P<0.05) . The ratios of P-selection, GPⅡb/Ⅲa and GPⅠb with/without ADP stimulation in ITP patients were significantly different among various bleeding grades (P<0.05) . Higher proportion of GPⅠb with/without ADP stimulation was associated with higher risk of bleeding (OR=3.05, P=0.011) . Lower proportion of GPⅡb/Ⅲa and P-selection with/without ADP was associated with higher risk of bleeding (OR=0.32, P=0.023; OR=0.04, P=0.006, respectively) . Conclusion Platelet activation index could accurately assess the degree of bleeding in patients with ITP, and also be used as the observation index and reference index for treatment.

Objective: To investigate the expression and molecular mechanism of dickkopf 1 ( DKK1 ) in tongue squamous cell carcinoma (TSCC) by bioinformatics method and molecular biology experiments． Methods: The patients information wasdownload from TCGA-TSCC database，the differentially expressed genes between the cancer and normal tissues were screened by NetworkAnalysed site，the key genes and clinical prognosis were identified through Kaplan-Meier analysis and Lasson regression，the functions and pathways of differentially expressed genes were gained by GO and KEGG database，the expression of DKK1 mRNA and protein in TSCC as well as its relationship with clinicopathological features were analyzed by UALCAN database and immunohistochemistry．Western blot assay was conducted to detect the protein expression of DKK1 in TSCC cells，and siRNA was used to konck down the expression of DKK1 protein in Cal27 cells. Results : The three key genes DKK1，CYP19A1 and IRX4， which were highly expressed in tongue squamous cell carcinoma and the survival rate of TSCC patients with high expression group was poor，were screened through NetworkAnalysed ，Kaplan-Meier analysis and Lasson regression method．UALCAN database showed that the mRNA level of DKK1 in TSCC tissues was higher than that in normal tissues，and its high expression was significantly correlated with clinical stage，histological grade and lymph node metastasis of TSCC patients．The immunohistochemistry assay suggested that the positive rate of DKK1 protein in clinical stage Ⅲ + Ⅳ TSCC tissues was significantly higher than that in stage Ⅰ + Ⅱ TSCC tissues．In addition， the expression level of DKK1 protein in TSCC tissues was significantly higher than that in adjacent tissues．Western blot assay also showed that the protein expression of DKK1 in TSCC cell Cal27 was much higher than normal oral epithelial cell HOEC．When knock down the protein expression of DKK1 in Cal27，the expression of β-catenin、p- p65 和 p65 werealso reduced． Conclusion DKK1 is highly expressed in tongue squamous cell carcinoma tissues and cells and plays an important role．It may be a new target for early diagnosis and drug treatment of TSCC.