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Objective To investigate the incidence and bacterial etiology of stent associated respiratory tract infec-tion (SARTI) caused by two types of airway stents.Methods Silicone and coated metal airway stent were placed into patients with central airway stenosis caused by varied pathologies. The incidence of stent related respiratory tract infection,bacteria etiology of SARTI and improved dyspnea score were compared between two groups receiving different airway stent.Results 1)Totally 171 patients received airway stents, and among them, 39 patients (22.81%) developed SARTI.2)The incidence of SARTI in metal stent group and silicone stent group was 29.21% (26/89) vs.15.85% (13/82),P<0.05;3)Bacterial spectrum of SARTI was different in metal and silicone stent groups:staphylococcus aureus was 38.46% vs. 69.23%,respectively;candida albicans was 23.08% vs. 0%,re-spectively;Singular proteus was 7.26% vs.0%,respectively;4)The narrowed lumen was improved from 74.27%± 7.13% to 17.64%±6.22%in the metal stent group,while the data was improved from 74.94%±9.18% to 12.68%± 8.32% in the silicone stent group (P<0.01). Accordingly, the dyspnea symptomscore was improvedfrom 2.85 ± 0.89 to 0.85±0.68 in metal stent group,and from 2.88±0.91 to 0±0.61 in the silicone stent group (P<0.05). Conclusions Compared with metal airway stents,silicone stents have a lower incidence of SARTI,which mightbe due to the projections in the silicon stent surface and wider expanded in the bronchial stenosis.
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Objective To construct a human tumor necrosis factor (hTNF-a) plasmid and identify it to optimize the fermentation conditions of hTNF-α protein so as to achieve high expression in Escherichia coli.Methods The gene of hTNF-a was cloned into pET24a vector to obtain the pET24a-hTNF-a expression plasmid that was transformed into Escherichia coli BL21(DE3),and the expression conditions of BL21 (DE3) were optimized.Results The plasmid of pET24a-hTNF-α was successfully constructed and identified by PCR and digestion,which was consistent with the target fragment hTNF-α.The plasmid was transformed into Escherichia coli BL21(DE3),the best induced expression conditions of Escherichia coli BL21 (DE3) were as follows:M9+LB medium,37℃,0.5 mmol/L IPTG,pH =7.5,and induction time was 5 h.The results showed that dry weight of the cells and the rate of TNF were increased by 2.56 times and 3.68 times,respectively,and the expression rate of hTNF-α was increased by 3.49 times from 9.38％ to 32.74％.Conclusion The optimal conditions for the expression of plasmid pET24a-hTNF-α in Escherichia coli were determined.
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<p><b>OBJECTIVE</b>To detect the infection of human papillomavirus (HPV) 16/18 in patients with head and neck squamous cell carcinoma and explore the relationship between HPV infection and expressions of Ki-67 and P53 proteins in tumor tissue.</p><p><b>METHOD</b>The level of HPV 16/18 DNA was measured by real time polymerase chain reaction, and Ki-67 and P53 proteins were measured by immunohistochemistry in tissues from head and neck squamous cell carcinoma.</p><p><b>RESULTS</b>HPV 16/18 DNA was detected in 62.8% of our patients. In each cancer tissue sample, Ki-67 protein was expressed between 2% to 70%. P53 protein was expressed in 46.15% of our patients. No significant relation was found between HPV 16/18 DNA level and sex, smoking, drinking, and tumor clinical stages. However, level of HPV 16/18 DNA was found to have positive relation with tumor pathological grades and negative relation with P53 protein expression. No relation with Ki-67 protein expression was found.</p><p><b>CONCLUSION</b>Head and neck squamous cell carcinoma may be initiated by HPV 16/18 infection and the mechanism in carcinogenesis involves abnormal expression in P53 protein.</p>