Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity. The process is critical for the ecology of the oral microflora and oral health. Although molecular mechanisms for spacer acquisition are known, it has never been established if this process is associated with the morphological changes of bacteria. In this study, we demonstrated a novel Cas2-induced filamentation phenotype in E. coli that was regulated by co-expression of the Cas1 protein. A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function. By imaging analysis, we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division. This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.

BACKGROUND:As the cardiovascular device, biomaterials applied under the blood-contact conditions should have anti-thrombotic, anti-biodegradable and anti-infective properties. OBJECTIVE:To review the research progression in polymer materials for implantation and intervention in cardiovascular tissue engineering and to explore the biocompatibility, blood compatibility and cytocompatibility of the surface-modified polymer biomaterials based on the surface endothelialization using tissue engineering techniques. METHODS:We retrieved PubMed and Wanfang databases for relevant articles publishing from 1963 to 2015. The key words were“Biocompatibility, Blood compatibility, Biomedical Materials, Biomedical polymer materials”in English and Chinese, respectively. Those unrelated, outdated and repetitive papers were excluded. Literatures addressing the blood compatibility, biocompatibility, and cytocompatibility of the surface-modified polymer biomaterials based on the surface endothelialization using tissue engineering techniques were investigated by summarizing function of vascular endothelial cel s, tissue-engineered endothelial cel s on the implant surface, fixation of cel growth-promoting factor on the surface of polymeric biomaterials, and endothelialization of the material surface. RESULTS AND CONCLUSION:Total y 71 relevant articles were included. The tissue-engineered modification of endothelial cel s on the surface of polymer biomaterials and their biocompatibility and cel compatibility are crucial for developing novel polymer materials for implantation and intervention in cardiovascular tissue engineering. Through in-depth studies of the types and applications of polymer biomaterials, cardiovascular medical devices and implantable soft tissue substitutes, the differences between the surface and the body wil be reflected in the many layers of molecules extending from the surface to the body. Two major factors, surface energy and molecular mobility, determine the body/surface behaviors that include body/surface differences and phase separation. Considering the difference between the body/surface composition, an additional determinant is indispensable, that is, the crystal ization behavior of each component.

INTRODUCTIONThe current metastatic category (M) of nasopharyngeal carcinoma (NPC) is a "catch-all" classification, covering a heterogeneous group of tumors ranging from potentially curable to incurable. The aim of this study was to design an M categorization system that could be applied in planning the treatment of NPC with synchronous metastasis.

METHODSA total of 505 NPC patients diagnosed with synchronous metastasis at Sun Yat-sen University Cancer Center between 2000 and 2009 were involved. The associations of clinical variables, metastatic features, and a proposed M categorization system with overall survival (OS) were determined by using Cox regression model.

RESULTSMultivariate analysis showed that Union for International Cancer Control (UICC) N category (N1-3/N0), number of metastatic lesions (multiple/single), liver involvement (yes/no), radiotherapy to primary tumor (yes/no), and cycles of chemotherapy (>4/≤4) were independent prognostic factors for OS. We defined the following subcategories based on liver involvement and the number of metastatic lesions: M1a, single lesion confined to an isolated organ or location except the liver; M1b, single lesion in the liver and/or multiple lesions in any organs or locations except the liver; and M1c, multiple lesions in the liver. Of the 505 cases, 74 (14.7%) were classified as M1a, 296 (58.6%) as M1b, 134 (26.5%) as M1c, and 1 was not specified. The three M1 subcategories showed significant difference in OS [M1b vs. M1a, hazard ratio (HR) = 1.69, 95% confidence interval (CI) = 1.16-2.48, P = 0.007; M1c vs. M1a, HR = 2.64, 95% CI = 1.75-3.98, P < 0.001].

CONCLUSIONSWe developed an M categorization system based on the independent factors related to the prognosis of patients with metastatic NPC. This system may be helpful to further optimize individualized care for NPC patients.

BACKGROUND:Cardiovascular biomaterials applied under the blood-contact conditions must have anti-thrombotic, anti-biodegradable and anti-infective properties. OBJECTIVE:To develop novel polymer materials for implantation and intervention in cardiovascular tissue engineering and then to explore the biological, blood and cellcompatibilities of corresponding surface-modified polymer biomaterials based on surface construction and biological response.
METHODS:We retrieved PubMed and WanFang databases for relevant articles publishing from 1984 to 2013. The key words were“biocompatibility, blood compatibility, biomedical materials, biomedical polymer materials”in English and Chinese, respectively.
RESULTS AND CONCLUSION:Here, we analyze the fol owing four aspects:protein adsorption, biometric identification in celladhesion, and the“waterfal model”for enzyme catalysis during blood coagulation and fibrinolysis. Consequently, it is concluded that the functional surface construction of polymer biomaterials and research on corresponding biocompatibility and endothelial cellcompatibility are crucial for developing novel polymer materials for implantation and intervention in cardiovascular tissue engineering. Through in-depth studies of the types and applications of polymer biomaterials, cardiovascular medical devices and implantable soft tissue substitutes, the differences between the surface and the body wil be reflected in the many layers of molecules extending from the surface to the body. Two major factors, surface energy and molecular mobility, determine the body/surface behaviors that include body/surface differences and phase separation. Considering the difference between body/surface composition, an additional determinant is indispensable, that is the crystal ization behavior of each component.

BACKGROUND: Biomedical materials contact internal environment of human body, and sometimes are implanted into organism. Therefore, they should have biocompatibility, chemical stability, suitable physical mechanical function and simple processing and molding, but no toxicity.OBJECTIVE: To investigate the preparation of biomedical polymer anticoagulant materials in the aspects of bioinert material, biological active surface, albumin structure and application in anticoagulation.METHODS: A computer-based online search of PubMed and Wanfang database was performed for articles related to preparation of biomedical polymer anticoagulant materials published between 1969 and 2010.RESULTS AND CONCLUSION: Currently preparation of anticoagulant materials commonly utilizes bioinert surface or bioactive surface alone, which has obtained good effects, but the biocompatibility, such as blood compatibility, cannot be retained for a long period of time. The combination of bioinert surface and bioactive surface plus albumin, natural constitutions in human blood may be the trend of anticoagulant materials development. Polyethylene glycol with high bioinert property in combination with albumin recognition factor cibacron blue with high bioactivity can be used to prepare active modifier, which is used to modify polyurethane.

This paper aimed to present the surface modification of tissue engineering materials and its correlation with cell compatibility from the aspects of cell-compatibility polymer surface group transformation and bioactive molecule immobilization.

Objective To explore the value of transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in diagnosing adult multiple atrial septal defect (MASD). Methods Thirty adult patients with MASD were examined with TTE, 25 patients were examined also with TEE, 26 patients were examined with cardiac catheterization as well. Transcatheter closure of MASD was performed in 20 patients and succeeded in 18, while open-chest operation was performed in 4 patients. Results Foramen secundum atrial septal defect was diagnosed with both TTE and TEE with an accuracy rate of 60.00% (18/30) and 96.00% (24/25), respectively. The main color Doppler flow imaging (CDFI) feature of adult MASD was multiple colorful left-to-right shunt signals through the atrial septal designated, i.e. colander sign of CDFI. Conclusion TTE has some difficulties and TEE has specific value in diagnosing adult MASD. TTE can be used before open-chest operation. TEE is necessary before transcatheter occlusion to make sure of the amount and location of atrial septal defect.

Surface physical chemical properties of tissue-engineered materials are greatly important for histocompatibility of the materials. Therefore, surface modification based on original physical mechanical performance could promote cell attachment and growth or bioactive molecule, and significantly improve material cell compatibility. To date, plasma and grafting has become main methods of surface modification of polymers. This paper introduced plasma and grafting methods of surface modification of materials and the application in tissue engineering.

BACKGROUND: The development of tissue engineering has provided a possibility for repairing and reconstructing tissues or organs. However, studies on biomedical tissue-engineered and polymer tissue-engineered materials need to be investigated. OBJECTIVE: To clarify the content of tissue engineering and the application of polymer material in tissue engineering from the point of biocompatibility. RETRIEVAL STRATEGY: Using the terms "tissue engineering, tissue engineering materials, Polymers materials, bio-compatibility, bio-compatibility materials, cell-compatibility, cell-compatibility materials", we retrieved PubMed database to identify studies published between January 1990 and December 2007 in the English language. At the same time, we searched Wanfang database with the same terms in the Chinese language. After primarily selected, 81literatures were kept. Inclusive criteria: studies, whose contents are related to biocompatibility of tissue-engineered materials. Exclusive criteria: repetitive studies or Meta analysis. Thirty literatures corresponded to the inclusive criteria, and fifty-one were rejected due to obsolete or repetitive contents. Among the 30 included literatures, 19 were about biocompatibility, and the remaining 11 about cellular compatibility materials. LITERATURE EVALUATION: The included studies were mainly from Pubmed database and Wanfang database. A total of 25 treatises and 5 reviews were kept. DATA SYNTHESIS: The content of tissue engineering consisted of seeded cell inoculation, biomaterial implanting and cell transplantation. Allogenic, autogenous, and xenogenous tissues were in vitro broken into cells, and then reconstructed through inoculation and proliferation by gene reconstruction technique. Much attention should be focused on how to reconstruct tissue-engineered materials with materials and living cells, I.e. To reconstruct active materials with biological functions. Tissue-engineered materials should have the best interface reaction effect between material surface and cells. Therefore, the core of studying tissue-engineered materials is to design a device, which has chemical molecular level and three-dimensional molecular level cell/material mixed surface, and also has a three-dimensional molecular level appearance corresponding to biomechanical requirement. Polymer materials have good physical mechanical functions, and their molecular structures are closer to living body. Therefore, polymer materials are widely used as biomaterials and exert an important role in the field of tissue engineering. CONCLUSION:To study biomaterials with good tissue compatibility is the basis for tissue engineering development. Polymer materials are widely used in the tissue engineering due to their good property and molecular structure closer to living body.

AIM:To analyze the mechanism,thermadynamic theoretical basis,dynamic mechanism and influencing factors of thermally induced phase separation (TIPS)in order to completely grasp the factors affecting the size,distribution and form of pores,so that the adjusted range of pore can be widened and the preparation of Porous membrane can be repeated and controlled.METHODS: Considering from the structural characteristics of tissue engineered materials,the methods of preparing porous membrane using TIPS technique,the hermadynamic theoretical basis,dynamic mechanism and influencing factors were analyzed,the problems and investigative directions in the future were also analyzed.TIPS technique is a process of phase separation of polymer homogenous solution under quenching,and it is suitable for diameter and structural form of the micropore materials prepared using TIPS are closely correlated with the kind and dispensing proportion of polymer attrnuant,polymer concentration and polymer molecular mass,etc.conducted,including determination of polymer-solvent system phase diagram,study of form and appearance of porous membrane of different thickness,study of form and appearance of porous membrane prepared with systems of different X,which is the parameter of polymer-solvent interaction.