Using gene fusion technology, polypeptide fusion tags can be engineered into target proteins at the genetic level.The resultant recombinant proteins may possess the biochemical properties of the imported fusion tags.Therefore, it is possible to take advantage of fusion tags to improve and evaluate protein expression, to detect and track protein targets, and to purify and characterize proteins.However, it is necessary to eliminate any influence of the fusion tag in structural characterization experiments or in isolating pharmaceutical proteins.Scientists must therefore remove fusion tags prior to structural and functional analyses when fusion tags are suspected of interfering with the biological activity of a protein or influencing its behavior.The fusion tag can be removed by several methods including harsh chemical treatment, mild enzymatic cleavage by endoprotease or exoprotease, and intein-mediated self-cleavage.Here the literature is reviewed in relation to principles, applications, and approaches of each method.

95%). Conclusion Immunomagnetic separation can effectively isolate and purify PSCs.

Objective To investigate the clinical features,diagnosis,treatment and prognosis of gastric neuroendocrine carcinoma (G-NEC).Methods Clinical data of 52 G-NEC cases were analyzed.Follow-up was conducted by telephone.The survival curves were drawn using Kaplan-Meier method.Univariate analysis was performed by the Log-rank test and multivariate analysis was performed by COX proportional hazards model.Results The median overall survival rate was 19 months (range 6 to61 months),and the overall 1,3,5-year survival rates were 74％,16％ and 5％ respectively.Tumor stage surgery,vascular nerve involvement and Ⅲ and Ⅳ phase chemotherapy were related to prognosis (x2 =24.254,10.005,7.261,8.790,all P ＜ 0.05).Multivariate analysis showed tumor stage and vascular nerve involvement were independent prognostic factors (x2 =17.170,5.810,all P ＜ 0.05).Conclusion G-NEC is a highly malignant tumor with poor prognosis.Preoperative diagnosis rate is low.Surgery is the treatment of first choice.Definite diagnosis depends on postoperative pathology and immunohistochemical examination.

To investigate the technique of sorting high-purity precartilaginous stem cells from rat's perichondrium, neonatal rat's perichondrium cells suspensions were incubated with monoclone antibody of anti-fibroblast growth factor receptor-3 (anti-FGFR-3), and the labeled cells were separated from the suspension in the magnetic field by immuno-beads coated with the second antibody. Purity of the sorted neural stem cells was found to be 93.0%-99.0%, with living cells amounting to 80% -85 %. The magnetic cell sorting system could effectively separate precartilaginous stem cells from perichondrium cell suspensions.

Herpes simplex virus (HSV) is a double-stranded DNA virus that can infect skin and mucosal epithelial cells. It can establish latency in sensory neurons and sporadically reactivate from these cells. In order to reply to attacks of the host and evade the immunity surveillance during infection and reactivation, HSV has developed a multitude of clever strategies. Dendritic cells (DCs), one of the most important antigen-presenting cells (APC), can recognize pathogens at the infection sites and activate specific T cells, thus playing a crucial role in the host immunity against virus infection. This paper reviewed the mechanism of the host immunity against HSV, especially the role of DCs in HSV-induced immune responses and the future research perspective.

BACKGROUND:There is a lack of study on material properties and parameters of foot finite element models in China. Vernier caliper is a common method for measuring the width and thickness of ligaments and tendons to calculate the cross-sectional area.
OBJECTIVE:To design a new ligament cross-sectional area measuring instrument to improve the measurement accuracy.
METHODS:The cross-sectional area of the five fresh cadaver ankle ligaments was respectively measured using the new instrument and vernier caliper, and then a comparative analysis of the two measurement methods was performend.
RESULTS AND CONCLUSION:The cross-sectional area of anterior talofibular ligament, calcaneofibular ligament, tibionavicular ligament and calcaneotibial ligament was (20.61±7.52), (22.38±11. 49), (33.09±9.91) and (28.20±10.88) mm2, respectively measured by the vernier caliper, and (17.59±4.03), (20.77±7.91), (28.08±8.14) and (30.39±7.98) mm2 by the new ligament cross-sectional area measuring instrument. These results suggest that this new measuring instrument is accurate, reliable and easy to operate, which can be used as a special instrument to measure ligament cross-sectional area, but further studies wil be necessary.

Objective PB840 ventilator to explore non-invasive ventilation (NIV) in the ICU of the application,efficacy and safety.Methods Application PB840 Ventilator-Non-invasive mechanical ventilation in the treatment of the seven cases of different causes of respiratory failure patients,non-invasive ventilation in the treatment of 4 h,the blood gas (PaO2,PaCO2 and pH value) analysis and analysis of clinical symptoms to improve the situation.Results Patient before and after treatment of PaO2,PaCO2 and pH compared to the value there is significant difference.Target to improve the blood after treatment significantly (P<0.05),reduce or alleviate the symptoms of sick;cyanosis improved.However,leakage is still a major disadvantage,some patients can not tolerate when there is need to immediately replace invasive mechanical ventilation.Conclusion PB840 ventilator mode non-invasive ventilation can improve the patient′s respiratory failure and clinical symptoms of blood-gas target,but most critically ill patients should be carefully applied.

In order to improve the efficacy of vibration expectoration and prevent secondary injury in patients with chest trauma,the body surface marking method was used in vibration expectoration.The exact injured locations and areas were identified via CT ot X-ray results.Then,the restricted and focused areas of expectoration were marked with red and green colors,which could guide the machines to avoid the fracture sites,reduce pain,prevent secondary injury and administrate effective expectoration in the areas of sputum and atelectasis.However,the dynamic CT or X-ray results must be used for reference to ensure the accuracy of the body surface marking.

Objective To clone and express bradyzoite antigen 1(BAG1) gene of T. gondii,and analyze the immunoreactivity of the recombinant product. Methods The differentiation of T. gondii RH strain tachyzoites into bradyzoites was induced in vitro,and the coding sequence of BAG1 was amplified from bradyzoites by RT-PCR. The PCR product was analyzed by sequencing. The BAG1 coding sequence was further subcloned into the plasmid pET32a(+). The plasmid pET32a(+)-BAG1 was then transformed into BL21(DE3) to express after IPTG induction. The expression product was purified with Ni-NTA agarose and the purified BAG1 was further analyzed by Western blotting and ELISA. Results BAG1 cDNA was amplified from bradyzoites. After IPTG induction,BAG1 was expressed in a fusional form in E. coli. Western blotting showed that the purified recombinant protein could be specifically recognized by sera from mice chronically infected by T. gondii B36 strain. ELISA showed that the positive rate of T. gondii IgG antibodies of 350 human sera detected by the recombinant BAG1(17.4%) was higher than by recombinant SAG1 (12.6%)(P

OBJECTIVE To explore the features,developing trend and factors of hospital infection in patients with iatrogenic injury.METHODS Retrospective surveys of hospital infections in 750 cases with iatrogenic injury were carried out in hospital between 2000 and 2007.RESULTS The incidence of hospital infection in patients with iatrogenic injury was 87.39%.Among them,hospital wound infection was the highest(87.39%),the second one was cavity infection(8.98%).The leading causative microorganisms were Gram-negative bacteria.CONCLUSIONS It is imperative to make effort to decvease the morbidity of hospital infections.We hope that the iatrogenic injury can be brought into the category of public health as soon as possible to enhance the medical care service and secure safty and health of the patients.