Hyaluronic acid is a linear acid mucopolysaccharide composed of repeating disaccharide glucuronic acid and N-acetyl-glucosamine units,which is widely used in medicine,cosmetics,food and other fields.Traditional studies have made significant achievements in improving the production of hyaluronic acid by optimizing the fermentation parameters,but have reached the upper limit,and the natural strains have the increasing disadvantages of high cost of fermentation medium and pathogenicity.With the rapid development of molecular biology technology and the continuous research on the genes related to hyaluronic acid synthesis,the research focus has gradually shifted to the use of genetic engineering technology to construct high yield,safe and specific molecular weight hyaluronan genetically engineered strains.Here the strategies and research progress of genetic engineering for the production of hyaluronic acid were reviewed.

Objective: To study the protective effect of anti-tumor necrosis factor-?antibody (TNF-? Ab) on lung injury after cardiopulmonary bypass(CPB). Methods: 20 patients with valve diseases underwent valve replacement under CPB. The patients were randomly divided into two groups: control group and TNF-? Ab group. In the TNF-? Ab group, human TNF-? Ab was dropped into the intracheal tube before operation and just after releasing the aortic clamp, respectively. Lung dynamic compliance, blood neutrophils count and TNF-? from the right and left atrium were determined perioperatively. Results: The dynamic compliance of the lung in TNF-? Ab group was higher than that in control group. TNF-? Ab can reduce releasing of TNF-? and restrain leukocyte accumulation in the lung. Conclusion: TNF-? Ab has markedly protective effect on lung injury after CPB.

Objective To characterize the electroanatomical mapping and to assess the value of radiofrequency ablation of atrial tachycardia (AT) in left atria. Methods Nine patients with AT in left atria were studied. Three-dimensional electroanatomical maps were constructed in left atrium using electroanatomical mapping system (Carto). The type of AT (focal or macroreentrant) was identified by the electroanatomical maps, and the ablation targets were at the earliest activation sites or the isthmus of circuit. Results There were ten ATs in 9 cases. The relatively early A waves were recorded in middle, distal or proximal parts of coronary sinus catheter. Nine focal ATs were diagnosed. The activation maps demonstrated that the earliest activation sites were at the ostium of pulmonary veins ( n =5), posterior area of left atrium ( n =2), ostia of left atria appendage ( n =1) or left atria appendage ( n =1) respectively. One macroreeentrant AT was diagnosed, whose circuit propagated through the isthmus, formed by the right superior pulmonary vein and fossa ovalis. Eight focal ATs were all ablated successfully at the earliest activation sites, and one AT from left atria appendage was ablated unsuccessfully. Line of ablation was performed at the isthmus of the macroreentrant AT. During a period of 6-30 months follow-up, one patient with focal AT recurred and underwent another ablation with successful result. No complication occurred. The procedure time and the fluoroscopic time were 90-140 min, 8-16 min respectively in successful cases. Conclusion These results suggest that electroanatomical mapping of AT in left atria may facilitate rapid and accurate identification of the type of AT and guide ablation safely or effectively with less fluoroscopic time and higher success rate, especially in unsuccessful cases with conventional technique.

Objective To evaluate clinically electroanatomical mapping and ablation of cardiac arrhythmias under the Carto system. Methods Fifty-six patients with various tachycardias indicated for electrophysiological study and radiofrequency ablation were included in this study, among of whom, 49 suffered from supraventricular tachycardia, and 7 ventricular tachycardia (VT). Carto system was utilized during ongoing tachycardia or sinus rhythm, 7F Navi-Star catheter was introduced into the interested cardiac chamber and underwent three-dimensional electroanatomical mapping. The mechanism and origin of cardiac arrhythmia were assessed by activation and propagation map, with which to guide radiofrequency ablation. Results The success ablation rate was 94.6% (53/56). One right accessory pathway (AP), one atrial tachycardia (AT) and one atypical atrial flutter (AF) had failed session. The procedure time was 128?59 minutes, and the fluoroscopic time 14?12 minutes. One patient had complcation of pneumothorax. No conduction block occurred. After follow-up of 1-14 months, one left AT recurred and had another succssful session. Conclusion The study demonstrates that Carto system is a safe and effective tool and may be applied for mapping and ablation of various tachyarrhythmias. It is helpful to guide catheter ablation and shorten fluorocopic time by its ability of associate intracardiac electrograms with their three-dimensional anatomic structure. It also lessen complication and recurrence by tagging the critical cardiac structures and utilize its location memory function. Our experience suggest that carto system has important role in the guidance of mapping and ablation in AT、AF、VT and complex or recurrent AP cases.

Collagen is a kind of natural biomedical material and collagen based three-dimensional porous scaffolds have been widely used in skin tissue engineering. However, these scaffolds do not meet the requirements for artificial skin substitutes in terms of their poor mechanical properties, short supply, and rejection in the bodies. All of these factors limit their further application in skin tissue engineering. A variety of methods have been chosen to meliorate the situation, such as cross linking and blending other substance for improving mechanical properties. The highly biomimetic scaffolds either in structure or in function can be prepared through culturing cells and loading growth factors. To avoid the drawbacks of unsafety attributing to animals, investigators have fixed their eyes on the recombinant collagen. This paper reviews the the progress of research and application of collagen-based 3-dimensional porous scaffolds in skin tissue engineering.
Animals ; Biocompatible Materials ; Biomimetics ; Cell Culture Techniques ; Collagen ; chemistry ; Porosity ; Skin ; Skin, Artificial ; Tissue Engineering ; Tissue Scaffolds

Objective To study the seasonal changes of glucose levels per unit soft tissue of Oncomelania hupensis. Meth-ods O. hupensis snails were collected from the beach of the Qingyi River in Wuhu City,Anhui Province from August 2012 to July 2013. They were kept in minus 80℃refrigerator immediately. The male snails were distinguished from female,and their soft tissues were collected separately after crushing their shells. The hexokinase method was used to measure the glucose concen-trations,and the results were analyzed statistically. Results The contents of glucose decreased from March to July. The lowest glucose content in the female was 1.87μg/mg in March,and that in male was 3.70μg/mg in July. Both of them increased from August and reached peak levels in September(♀=57.38μg/mg,♂=44.39μg/mg),and then gradually decreased from Octo-ber to next January and increased in February. Conclusion The contents of glucose have seasonal changes regularly in O. hu-pensis.

Aim: To study the effect of Eudragit S-100, a pH-responsive polymer, on protein refolding level, using recombinant human keratinocyte growth factor-2 (rhKGF-2) as a model protein. Methods: The refolding of rh-KGF-2 was performed by directly diluting denatured rhKGF-2 into a refolding buffer containing different concentrations of Eudragit. The ability of Eudragit S-100 to enhance protein refolding level was investigated using MTT assay, reverse phase HPLC, fluorescence emission spectroscopy and circular dichroism spectroscopy. Results: The addition of Eudragit S-100 in the refolding buffer significantly increased the rhKGF-2 refolding yield to 71%, when dilution refolding was conducted at 0. 5 mg/mL rhKGF-2. The outcome from the refolding study showed possibility of a special interaction between rhKGF-2 and Eudragit, suggesting that the refolding-enhancing ability of Eudragit S-100 was due to this interaction between Eudragit S-100 and rhKGF-2. Mean while, the result showed that the concentration of urea was also an important factor for the optimization of the refolding in the presence of Eudragit. Conclusion: Eudragit S-100 can significantly increase the refolding level of rhKGF-2.

Objective:To explore the clinical effect of prostatil combined with diosmin on the elderly patients with chronic prostatitis (CP) and the macrophage inflammatory protein-2 (MIP-2) and macrophage inflammatory protein-lα (MIP-lα) in prostate fluid and serum.Methods:126 cases of elderly patients with CP in our hospital fiom January 2015 to September 2016 were selected and randomly divided into two groups.Prostatil combined with diosmin were provided to the patients in observation groups (63 cases) while the control group (63 cases) was treated by prostatil alone.The clinical effect,MIP-2,MIP-1α levels in the prostate fluid and serum before and after therapy as well as the incidence of adverse reactions were observed and compared between two groups.Results:At 12 weeks after treatment,the total effective rate of observation group was 93.7％,which was obviously higher than that of the control group (81.0％,P＜0.05).The MIP-2 and MIP-1α levels in prostate fluid and serum of both groups at 12 weeks after therapy were significantly lower than those before therapy (P＜0.01),which were significantly lower in the observation group than those of the control group at the same time (P＜0.01).There was no significant difference in the incidence of adverse reactions between the two groups (P＞0.05).Conclusion:Prostatil combined with diosmin could more safely and effectively improve the clinical efficacy in the treatment of elderly patients with CP/CPPS,which might be related to reduce the levels ofMIP-2,MIP-lα in serum and prostatic fluid.

Objective:To investigate effects of tumor specific TCR gene Vα12.2-Vβ7.1 modification on recognition of tumor antigen and activation of anti-tumor reactivity of T cells.Methods: T cells were transduced using recombinant Ad 5F35-TRAV-TRBV adenovirus ,and multiplicity of infection was optimized.Specific lysis of T cells was evaluated by calcein release assay.The frequency of apoptotic cells in target cells was detected by Annexin V /PI double-labeled FACS.The expression of FasL on T cells was analyzed by FACS.The secretion of cytokine IFN-γand IL-2 of T cells was determined by ELISA assays.Results: The highest tranduce efficiency was obtained at MOI 100 by recombinant Ad5F35-TRAV-TRBV adenovirus.The frequency of TCRVα12+Vβ7+cells reached above 25%3 days after transduction.TCR gene modification enhanced the ability of T cells to lyse HLA-A2+AFP+target cells(P<0.001), the ability of T cells to induce HepG-2 apoptosis(P<0.001),and expression of FasL on T cells(P<0.001).TCR gene modification also enhanced T cells to secret IFN-γafter coculture with antigen positive tumor cells ( P<0.001 ).Conclusion: Specific TCR gene modification by recombinant adeno virus effectively promotes T cells to recognize antigen positive tumor cell and exert anti -tumor reac-tivity.

Objectiv e:To investigate the effect of different culture conditions on the differentiation of Treg and Th17 to lay a foundation for exploring the methods to reverse the immune tolerance induced by tumor microenvironment.Methods:The IL-6 gene was cloned and stablely transferred into the tumor cell line expressing TGF-β.The conditioned mediums ( CM) were prepared by collecting the culture supernatants of tumor cell lines with or without IL-6 expression and used in the in vitro culture of peripheral blood mononuclear cells ( PBMC ) .The changes of Treg and Th17 in PBMC treated with different CM were detected with flow cytometry ( FCM) .Results:The expression of TGF-βin BEL-7402 was higher than that in HepG2.Thus the BEL-7402 was selected for preparation of cell line stablely transfected with IL -6 gene.ELISA detection confirmed the effective expression of IL -6 by the identified cell lines.It was showed that the Treg increased in PBMC treated with culture supernatants of tumor cells .However,the presence of IL-6 reversed the increase of Treg and promoted the differentiation of Th 17.Conclusion: The culture supernatants of tumor cells increases the proportion of Treg.However,the presence of IL-6 in this CM can reverse the increase of Treg and raise the proportion of Th 17.