ObjectiveTo investigate the feasibility,safety and efficacy of tracheal extubation with directly connected negative pressure suction. Methods86 patients with Ⅰ or Ⅱ degree of ASA,aged 18～65 years old,without history of respiratory disease,difficult airway and ventilation problems were involved in this study.All patients undergoing endotracheal general anesthesia were randomly divided into group A and B with 43 cases in each group.Group A used negative pressure directly connected to external side of the endotracheal tube before extubation.Group B used suction tube putting into the endotracheal tube before extubation.MAP,HR,ECG,SpO2,the condition of cough and expectoration and complicatons after extubation were recorded. ResultsIn group A the MAP,HR slightly increased,SpO2 slightly decreased,ECG showed no significant change,but the differences were not significant.In group B,MAP,HR,SpO2 showed significant difference compared with those before extubation and the corresponding period of group A. ConclusionsThe method that connecting negative pressure suction with endotracheal tube can effectively reduce the cardiovascular response during extubation,It also can avoid hypoxia,reduce the tracheobronchial injury and pulmonary complications.It's a practical good method in tracheal extubation.

Objective:To construct a recombinant plasmid DNA carrying the decorin( DCN) gene and study its therapeutic effect on hypertrophic scars of rabbit ears. Methods:The human decorin gene fragment amplified by PCR was cloned into plasmid vector pUDK to construct the recombinant plasmid pDCN, which was identified by enzyme digestion and sequencing. pDCN was transfected into 293T cells, and the expression of DCN and TGF-β1 was detected. The therapeutic effect of pDCN on rabbit ear hypertrophic scar model was observed by hypertrophy index, pathological examination and immunohistochemical staining. Results:The decorin gene was successfully inserted into pUDK, which was examined by enzyme digestion and sequencing. The expression level of mRNA and protein of DCN was up-regulated in 293T cells post pDCN transfection, and the expression of TGF-β1 was suppressed. Then the rabbit ear hypertrophic scars were treated with different doses of pDCN, and the results showed that the hypertrophy index of the medium dose (200 μg/cm 2) pDCN group was significantly lower than that of the PBS group ( P<0.05), while there was no significant difference in the hypertrophy index of the low dose and high dose pDCN group compared with the PBS group. The expression of DCN in ears skin in the medium dose pDCN group was significantly higher than that in the PBS group ( P<0.05). The pathological examination showed that inflammatory cell infiltration and fibrous deposition in scar tissue were significantly reduced. These results indicated that the medium-dose pDCN could effectively inhibit the hyperplasia of hypertrophic scar in rabbit ears. Conclusions:pDCN, the plasmid carrying decorin gene, has therapeutic effects on hypertrophic scars of rabbit ears by inhibiting TGF-β1 expression.

Objective:To construct a recombinant plasmid DNA carrying the decorin( DCN) gene and study its therapeutic effect on hypertrophic scars of rabbit ears. Methods:The human decorin gene fragment amplified by PCR was cloned into plasmid vector pUDK to construct the recombinant plasmid pDCN, which was identified by enzyme digestion and sequencing. pDCN was transfected into 293T cells, and the expression of DCN and TGF-β1 was detected. The therapeutic effect of pDCN on rabbit ear hypertrophic scar model was observed by hypertrophy index, pathological examination and immunohistochemical staining. Results:The decorin gene was successfully inserted into pUDK, which was examined by enzyme digestion and sequencing. The expression level of mRNA and protein of DCN was up-regulated in 293T cells post pDCN transfection, and the expression of TGF-β1 was suppressed. Then the rabbit ear hypertrophic scars were treated with different doses of pDCN, and the results showed that the hypertrophy index of the medium dose (200 μg/cm 2) pDCN group was significantly lower than that of the PBS group ( P<0.05), while there was no significant difference in the hypertrophy index of the low dose and high dose pDCN group compared with the PBS group. The expression of DCN in ears skin in the medium dose pDCN group was significantly higher than that in the PBS group ( P<0.05). The pathological examination showed that inflammatory cell infiltration and fibrous deposition in scar tissue were significantly reduced. These results indicated that the medium-dose pDCN could effectively inhibit the hyperplasia of hypertrophic scar in rabbit ears. Conclusions:pDCN, the plasmid carrying decorin gene, has therapeutic effects on hypertrophic scars of rabbit ears by inhibiting TGF-β1 expression.