42 Wistar rats were divided into three groups at random, liver cirrhosis (LC), portal vein stricture (PVS) and sham operation (SO) group. The changes of barrier capability of gastric mucosa in portal hypertensive rats were observed. The results demonstrated: the splanchnic blood flow of the portal hypertensive rats increased, as compared with the normal control group (Ｐ＜0.001), but actually gastric mucosa was under the condition of ischemia. Mucosa of gastric wall glycoprotein and PGE2 of gastric mucosa decreased, as compared with the normal control (Ｐ＜0.01); and more seriously decreased in cirrhotic portal hypertensive rats, there was no significant difference about amount of the basal acid secretion (BAS) among the three groups, but the amount of H＋ backdiffusion (H＋BD) was obviously increased, as compared with the normal control group (Ｐ＜0.001). The amount of H＋BD of cirrhotic portal hypertensive rats was the highest among this three groups. The results suggest that the barrier capability of gastric mucosa with portal hypertension is lower than that of the normal control group and much lower with cirrhotic portal hypertensive rats. The portal hypertensive gastropathy is associated with the lower capability of defense of gastric mucosa. The condition of liver function contributes to the change of barrier capability of gastric mucosa.
Abstract： Objective To investigate the change of tissue structure and epithelial barrier function of excluded esophagus after esophageal exclusion surgery for tracheoesophageal fistula (TEF). Methods Twentyeight hybrid dogs were divided into 3 groups with random number method. For group A (n=12), fistula was excluded; for group B (n=12), only the esophagus was excluded; and group C (n=4) was the control group. The normal and excluded esophagus of the three groups were observed through general sampling, HE staining, transmission electron microscope (TEM), scanning electron microscope (SEM) and Lanthanum trace labeling. The interstitial space dilation (ISD) of the cells on the esophageal mucosa was measured and the number of desmosome in the intercellular space was calculated. Results The changes of tissue structure and epithelial barrier function of the excluded esophagus were similar between group A and group B. Compared with group C, group A and B showed the following changes: esophageal structure changed, submucous glandular tissues reduced or disappeared; the interstitial space increased, the number of desmosome decreased, and the epithelial barrier function attenuated, but the basal lamina did not changed and lanthanum did not break through it. For the dogs in group C, esophageal mucosa could be observed, submucosa was complete and a large number of gland tissues and micrangiums could be seen in it. The number of desmosome for group A, B and C was 0.21±0.03 entries/μm2, 0.22±0.05 entries/μm2, and 0.32±0.03 entries/μm2 respectively, which showed a significant difference between group A, B and group C (Plt;0.05), while there was no significant difference between group A and group B (Plt;0.05). The average interstitial space for group A, B and C was 2.11±0.56 μm, 2.04±0.77 μm, and 1.84±0.49 μm respectively. There was no significant difference between group A and B, while there was significant difference between group A, B and group C. Conclusion The esophageal exclusion surgery for refractory TEF is safe, feasible, and effective with few complications, and deserved to be popularized.
Objective To investigate the method of constructing a tissue engineered epidermis with human epidermal cells and polycarbonate membrane, and to establ ish a tissue engineered epidermis with barrier function which is intended to be the replacing model in vitro of skin irritation test. Methods The tissue engineered epidermis was constructed by using polycarbonate membrane as scaffold and stratified differentiated epidermis derived from human keratinocytes. The tissue engineered epidermis was cultured on an inert polycarbonate filter at the air-liquid interface. After 13 days of culture, the composition and structure of tissue engineered epidermis were observed by HE staining, immunofluorescence staining of keratin 10 (K10) amp; K13, K14, laminin,involucrin, and filaggrin, and transmission electronic microscope. The half maximal inhibitory concentration of a substance (IC50) of SDS was determined in the penetration test of tissue engineered epidermis cultured in the absence (control group) or the presence (experimental group) of l i pid supplement for 18 hours. Results The constructed epidermis was similar to normalepidermis, which was consisted of a proliferating basal layer, differentiated spinous layer, granular layer, and stratum corneum. The IC50 values of tissue engineered epidermis cultured in the control group and experimental group were 0.072% (2.36 mmol/L) and 0.183% (6.00 mmol/L), respectively. Conclusion The tissue engineered epidermis constructed on polycarbonate membrane has normal composition and structure and barrier function corresponding to the normal epidermis.
Objective To investigate the effect of training courses of evidence-based medicine (EBM) on the knowledge, skill, attitude and behavior of medical postgraduates and to explore the barriers to evidence-based practice (EBP), so as to provide knowledge to improve further EBM teaching and EBP. Methods A total of 110 medical postgraduates of Sichuan University who selected EBM courses in the autumn semester of 2004 were given questionnaires that combined both open and closed questions. The KAB (knowledge, attitude and behavior) of EBM and barriers to EBP were compared before and after the training courses. Results Differences were observed in KAB of EBM and barriers to EBP after the training courses, compared to the assessments done before the courses. In “Knowledge”: there was a significant increase in the understanding of specific terms in EBM after the training courses (75% of the items showed a statistically significant improvement). This was especially marked for “absolute risk”, “systematic review”, “meta-analysis” and “publication bias” (Plt;0.01). We also found an improvement in familiarity with medical search engines (Plt;0.05). In “Attitude”: the mean scores for most items (55%) were relatively high both before and after the training courses (gt;4), and a significant improvement was observed in 2 items. These were “Strong evidence is lacking to support most of the interventions I use with my patients” and “EBP needs to take into account patient preferences” (Plt;0.01). The mean scores of 2 items were relatively low both before and after the training courses (lt;3). These were “the adoption of EBP places an reasonable demand on physical therapists” and “EBP does not take into account the limitations of my clinical setting”. Another 2 items had mean scores close to 5: “I need to increase the use of evidence in my daily practice” and “I am interested in learning or improving the skills necessary to incorporate EBP into my practice”. In terms of “Behavior”: the medical postgraduates continued not to think highly of the use of literature after the training courses. About 60% of the postgraduates did not read any literature related to their specialties at all. Although searching of MEDLINE and other electronic databases was relatively frequent (gt;6 times/month: 60.3% before training and 65.7% after training), using professional literature and research findings in the process of clinical decision-making was not equal (gt;6 times/month: 29% before training and 35.1% after training). No significant difference was observed in applying clinical practice guidelines before and after the training courses. As for “Barriers”: the postgraduates considered “poor ability to critically appraise literature” as the most important barrier both before and after the training courses. The second and third most important barriers were different compared to after the training courses. The barrier of “lack of research skills” was larger than that of “lack of information resources” before the training courses, but after that the course, the order of these was reversed. Conclusion The knowledge of medical postgraduates increased significantly after the current training courses of EBM. Some improvement was also found in attitude and behavior. The top three barriers to EBP were “Poor ability to critically appraise literature”, “Lack of information resources”, and “Lack of research skills”