Background The usual transbronchial coagulation techniques include microwave, argon plasma coagulation （APC）, electrocautery and cryotherapy. However, there are serious clinical problems in the safety of each. By an...Background The usual transbronchial coagulation techniques include microwave, argon plasma coagulation （APC）, electrocautery and cryotherapy. However, there are serious clinical problems in the safety of each. By analyzing the experimental data and clinical observations, we observed the variable effects of different coagulation techniques via bronchofibroscopy, to look for an optimal interventional management of luminal bronchus diseases, and evaluate the safety and the equivalent point. Methods Four kinds of coagulation techniques under bronchoscopy were performed on the fresh bronchus of healthy sheep, and the pathologic changes in all groups were observed under the microscope. The different treatment parameters were as follows： microwave 60 Wxl second, 3 seconds, 5 seconds and 40 W×1 second, 3 seconds, 5 seconds; APC 40 W×1 second, 3 seconds, 5 seconds; electrocautery 40 W×1 second, 3 seconds, 5 seconds; cryotherapy 100 Ω×60 seconds, 120 seconds. Results After treatment, ovine bronchial mucosa in all groups showed pathologic changes such as local necrosis and amotio of the mucosa lining epithelium, local submucosa coagulative necrosis or tissue defects, while inflammation in the surrounding tissue was not obvious. Under the same output power and action time, different methods had different outcomes. The damage by APC was the most superficial, microwave was the second, and electrocautery caused the worst damage. The study also found that effects of electrocautery at 40 W×3 seconds, microwave at 40 W×5 seconds or 60 W×3 seconds, APC at 40 W×5 seconds and cryotherapy at 100 Ω×120 seconds were the equivalent point conditions. The appearance included mucosa absence, partial submucosa absence, and collagen fiber coagulation in treatment areas. Conclusions Each coagulation technique has its own characteristic. It is very important to choose the appropriate power and action time of the suitable method according to the therapy requirement.展开更多
Background The extended-spectrum beta-lactamase （ESBL）-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous stu...Background The extended-spectrum beta-lactamase （ESBL）-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous studies have focused on the resistance genes in ESBL-producing strains,and the resistance-associated genetic environment of non-ESBL-producing strains has been ignored until now.Here,we investigated the occurrence and characteristics of non-ESBL-producing K.pneumoniae,which potentially carries unexpressed resistance genes.Methods K.pneumoniae strains were collected from five medical institutions in China from February 2010 to August 2013.The VITEK-2 ESBL detection system was used as a primary screen to identify the ESBL-producing phenotype,and the three primary types of ESBL-associated genes （CTX,SHV,and TEM） were detected by polymerase chain reaction （PCR） to confirm the strains presenting with a non-ESBL-producing phenotype.mRNA expression in the non-ESBL-producing strains was further screened by reverse-transcription PCR （RT-PCR） to validate their transcriptional efficiency.Results Out of 224 clinically isolated antibiotic-sensitive K.pneumoniae strains with a non-ESBL-producing phenotype,5 （2.2％） were identified to carry inactivated ESBL blaSHV genes with intact upstream promoter regions and resistance gene sequences.Interestingly,three of the five antibiotic-sensitive K.pneumoniae strains containing ESBL blaSHV genes still exhibited mRNA transcription of blasHv,while the other two exhibited no mRNA transcription.Conclusion These findings suggest that inactivated ESBL genes exist in non-ESBL-producing antibiotic-sensitive K.pneumoniae strains,which have the potential to transform the strain into an ESBL phenotype if an inappropriate application or overdose of antibiotics is implemented during clinical management.展开更多
文摘Background The usual transbronchial coagulation techniques include microwave, argon plasma coagulation （APC）, electrocautery and cryotherapy. However, there are serious clinical problems in the safety of each. By analyzing the experimental data and clinical observations, we observed the variable effects of different coagulation techniques via bronchofibroscopy, to look for an optimal interventional management of luminal bronchus diseases, and evaluate the safety and the equivalent point. Methods Four kinds of coagulation techniques under bronchoscopy were performed on the fresh bronchus of healthy sheep, and the pathologic changes in all groups were observed under the microscope. The different treatment parameters were as follows： microwave 60 Wxl second, 3 seconds, 5 seconds and 40 W×1 second, 3 seconds, 5 seconds; APC 40 W×1 second, 3 seconds, 5 seconds; electrocautery 40 W×1 second, 3 seconds, 5 seconds; cryotherapy 100 Ω×60 seconds, 120 seconds. Results After treatment, ovine bronchial mucosa in all groups showed pathologic changes such as local necrosis and amotio of the mucosa lining epithelium, local submucosa coagulative necrosis or tissue defects, while inflammation in the surrounding tissue was not obvious. Under the same output power and action time, different methods had different outcomes. The damage by APC was the most superficial, microwave was the second, and electrocautery caused the worst damage. The study also found that effects of electrocautery at 40 W×3 seconds, microwave at 40 W×5 seconds or 60 W×3 seconds, APC at 40 W×5 seconds and cryotherapy at 100 Ω×120 seconds were the equivalent point conditions. The appearance included mucosa absence, partial submucosa absence, and collagen fiber coagulation in treatment areas. Conclusions Each coagulation technique has its own characteristic. It is very important to choose the appropriate power and action time of the suitable method according to the therapy requirement.
文摘Background The extended-spectrum beta-lactamase （ESBL）-producing Klebsiella pneumoniae has increasingly become a major contributor to nosocomial infections and can exhibit multiple antibiotic resistance.Previous studies have focused on the resistance genes in ESBL-producing strains,and the resistance-associated genetic environment of non-ESBL-producing strains has been ignored until now.Here,we investigated the occurrence and characteristics of non-ESBL-producing K.pneumoniae,which potentially carries unexpressed resistance genes.Methods K.pneumoniae strains were collected from five medical institutions in China from February 2010 to August 2013.The VITEK-2 ESBL detection system was used as a primary screen to identify the ESBL-producing phenotype,and the three primary types of ESBL-associated genes （CTX,SHV,and TEM） were detected by polymerase chain reaction （PCR） to confirm the strains presenting with a non-ESBL-producing phenotype.mRNA expression in the non-ESBL-producing strains was further screened by reverse-transcription PCR （RT-PCR） to validate their transcriptional efficiency.Results Out of 224 clinically isolated antibiotic-sensitive K.pneumoniae strains with a non-ESBL-producing phenotype,5 （2.2％） were identified to carry inactivated ESBL blaSHV genes with intact upstream promoter regions and resistance gene sequences.Interestingly,three of the five antibiotic-sensitive K.pneumoniae strains containing ESBL blaSHV genes still exhibited mRNA transcription of blasHv,while the other two exhibited no mRNA transcription.Conclusion These findings suggest that inactivated ESBL genes exist in non-ESBL-producing antibiotic-sensitive K.pneumoniae strains,which have the potential to transform the strain into an ESBL phenotype if an inappropriate application or overdose of antibiotics is implemented during clinical management.
