The important function of the gastrointestinal tract in monitoring and sealing the host intestine from intruders is called the gut barrier.A variety of specific and nonspecific mechanisms are in operation to establish the host barrier,including luminal mechanism,secretion of the digestive enzymes,the epithelial cells together with tight junctions between them and the gut immune system.The pathogenesis of gut barrier dysfuntion is multifactorial.They can lead to the translocation of the intestinal bacteria.Sometimes,even the multiple organ dysfunction syndrome can happen.Nitric oxide,one of the smallest products of the cell,is known to have a very large role in diverse physiologic and pathological processes.Recent study shows its toxic metabolite,peroxynitrite(ONOO~(-)),play a major role in the intestinal mucosal injury.The purpose of this literature review is to provide a better understanding of the mechanism of the protection and injury to the gut barrier function about nitric oxide and peroxynitrite.

Objective To evaluate Tornwaldt′s cyst using MR imaging. Methods 1 452 cases with head MR imaging were reviewed. The signal intensity, shape, and size of the lesions were observed. Results Tornwaldt′s cyst were found in 18 of 1 452 cases (1 24%), all of the 18 cases were isointense to CSF on T 2WI and hyperintense to muscle on T 1WI.Tornwaldt′s cyst were round ( n =13)and ovoid ( n =5). The size of lesions were from 2 mm to 15 mm. There were 15 cases with adenoid hyperplasia. Conclusions Tornwaldt′s cysts occupied 1 24% in routine head MR imaging and were hyperintense to muscle on T 1WI and isointense to CSF ON T 2WI.

College of Stomatology of Wuhan University was the first dental school who introduced the Kavo head-simulator for clinical teaching.In this study,students of stomatology were investigated before and after head-simulator training and questionares were made.The results have showed that head-simulator teaching system not only raises the activity of student,consolidates the basic knowledge,develops the clinical thinking ability,but also increases the ability of clinical operational skill before clinical training.

Objective: To express the protein of HPV18E6 based on pET-32a(+) at high level and study the expression and significance of HPV18E6 proteins in laryngeal carcinoma. Methods: The HPV18E6 gene was amplified by PCR and cloned into pET-32a(+). The amplified fragment was inserted into the plasmid pET32a (+) that was digested with BamHⅠand Hind Ⅲ. The recombinant plasmid pET32/E6 was transformed into E.coli JM109 which was selected with ampicillin. The recombinant plasmids were successfully introduced into E.coli BL21(DE 3) and were induced by IPTG. SDS-PAGE and Western blot analysis were used to detect the confusion protein. Finally, the optimization of expression conditions, such as temperature, concentration of IPTG, was studied. Results: The recombinant plasmids were identified and confirmed with enzyme digestion and sequencing. The BL21(DE3) transformed recombinant plasmid pET32/E6 had expressed HPV18E6 recombinant protein effectively. The optimum conditions of expression were 37 ℃, 1 mmol/L IPTG. Conclusion:Prokaryotic expression vector pET-32a(+)-HPV18E6 was successfully constructed. The high-level expression of HPV18E6 was achieved in E.coli BL21(DE3).

Animal models of pulmonary artery hypertension (PAH),aiming to simulate human characteristics of the disease,have contributed extensively to understanding the pathophysiology of PAH and the investigation of experimental treatments.The classical models include monocrotaline models,chronic hypoxia model and so on,more new models were investigated in recent years.These animal models were not able to perfectly mimic human pathological characteristics of PAH because of the defect in different aspects.In this review,both typical and novel methods of PAH modeling were summarized and evaluated to provide a suitable guidance for the settlement of animal models which can meet human characteristics comprehensively.

Objective To study the values of MR total spine mobitrack(MTSM) technique in acute spinal trauma and spinal cord injury.Methods 71 patients with trauma in cervical vertebra,thoracic vertebra and lumber vertebra underwent MTSM scan.Results All 71cases obtained clear images of total spine and spinal cord,of which,2 cases were normal,69 cases showed fractures of vertebrae(including 36 cases showed fracture of single vertebrae,33 cases showed fractures of multiple vertebraes).69 cases with fracture of vertebrae,accompanied with 12 articles of vertebral body slippage,the 15 segments of spinal cord injury and the 19 places of the ligaments bruise.Conclusion MTSM technique is good to show the location and quantity of vertebral trauma and will greatly improve the diagnostic accuracy.

Objective:To explore the influence of RNAi mediated Slug silencing on the growth and metastasis of colon cancer in nude mice.Methods: HCT116 colon cancer cells use for 24 five-week-old nude mice implanted subcutaneously , established colon cancer xenograft model in nude mice ,all divided into blank control group ,negative control group and the experimental group ,each group had eight nude mices.All group were injected with saline , negative plasmid and lentivirus vectors respectively.Tumor growth was observed and draw tumor curved growth ,changes in tumor growth and lymph node metastasis between the groups were observed ,Slug gene and protein expression were detected by immunohistochemistry ,qRT-PCR and Western blot analysis.Results: Slug gene shRNA intervention group compared with the control group and negative control group ,tumor grew slower ,tumor mass was significantly reduced (3.08±0.31 vs 7.37±1.18,7.46±1.16,P＜0.01),experimental group of lymph node-positive rate was 36.3%( 4 /11 ) ,compared to the negative control group 77.8% ( 14/18 ) and the control group was 68.4% ( 13/19 ) ( P＜0.01 ).Conclusion: Targeted Slug RNA interference can significantly inhibit the growth of colon cancer in nude mice ,lymph node metastasis and the expression of the gene protein in cancer tissue ,Slug may be a potential molecular target for colon cancer gene therapy.

Objective To investigate four methods for establishing animal models of human breast cancer bone metastasis. Methods Thirty-two female nude mice aged 4-6 weeks were divided randomly into four groups (n=8 in each group). 5×105 MDA-MB-231 cells were injected into the body via the left second mammary fat pads (group A), the tail veins (group B), the left heart ventricles (group C) and the left tibia marrow cavities (group D), respectively. Tumor formations in situ were recorded in group A. Deaths after the injection were recorded. The surviving nude mice 49 days after the injection were subjected to pathological examination to determine bone metastasis. Results The rate of tumor formation in situ of group A was87.5 %(7/8). One mouse in group C died after the injection of MDA-MB-231 cells. The bone metastasis rate in groups A, B, C and D was zero (0/8), 12.5 % (1/8), 71.4 % (5/7) and 100 % (8/8), respectively. There was statistically significant difference in the bone metastasis rate between group A and group C, group A and group D, group B and group C; and group B and group D. Conclusion Injections of tumor cells via the breast fat pads and tail veins were not suitablemethods to establish animal models of human breast cancer bone metastasis. The bone metastasis model could be established efficiently by injecting tumor cells into the left heart ventricles or the bone marrow cavity of nude mice.

Objective To investigate the clinical manifestation,pathological characteristics,neurological imaging,indications,operative approach and microsurgieal technique of surgery for brain stem tumor.Methods 17 cases of brain stem tumor treated by applying microsurgical skills were retrospectively analyzed from Jan.2002 to Dec.2007.Ten cases were operated via the suboccipito-retromastoid approach,among which 5 situated in pons,3 in medulla oblongata and 2 invoved both pens and medulla oblongata;4 cases were performed via the posteromedian-suboccipital approach,among which 2 located in pens,1 in medulla oblongata and 1 involved both midbrain and pens;3 lesions situated in varying sites of mesencephalon were operated by the suboceipito-supratentorial,infratemporal approach and pterional approach respectively.Results In the series of the patients,lesion was totally excised in 6 cases,subtotally in one,without surgical mortality.All patients were followed up for years ranging from 5 months to 4 years.During the follow-up period,seven patients resumed work and normal life;4 patients could perform physical labor;3 patients obtained self care capability;2 patients needed to be taken care of,1 patient died from pneumonia after discharge.Conclusion Fine therapeutic efficacy and low disability rate could be obtained while applying microsurgical techniques to resect brain stem tumors with correct indication,appropriate approach and elaborate microneurosurgical skills.