1.Detection of carbapenemases and integrons distribution among imipenem-resistant Acinetobacter baumannii isolates
Qiaojuan HU ; Zhidong HU ; Jing LI ; Bin TIAN
Chinese Journal of Laboratory Medicine 2011;34(4):363-366
Objective To investigate the carbapenemases and integrons in imipenem-resistant Acinetobacter baumannii. Methods One hundred and three Acinetobacter baumannii were collected from Janurary 2008 to March 2010 in Tianjin Medical University General Hospital. The identification of strains and antimicrobial susceptibility test were performed by using Vitek-2 compact automatic system. Isolates of imipenem-resistant A. baumannii were screened for carbapenemases by modified Hodge test, improved threedimensional test and 2-mercaptopropionic acid synergy test. Isolates were then subjected to the multiplex PCR targeting genes encoding for OXA type carbapenemases, metallo-β-lactamases (MBLs) and integrases. The variable regions of integrons were amplificated and sequenced. Results Among the 103 isolates, 75 (72. 8% ) demonstrated positive in the modified Hodge test, 80 (77.7%)were positive in the improved three-dimensional test. No MBLs was found in the 2-mercaptopropionic acid synergy test. Eightyfour isolates were positive for blaOXA-51-like, blaOXA-23-like, and intI1; five were positive for blaOXA-51-like and blaOXA-23-like ;eight were positive for blaOXA-51-like and int11 ;two were positive for blaOXA-51-like and blaOXA-24-like ;four were only found positive for blaOXA-51-like. The blaOXA-58-like, IMP-1, VIM-2 and intI2 genes were all negative. Eighty-nine(96. 7% )of the intI1 positive strains owned the variable region. Two different cassettes arrangements were identified within class 1 integrons:81 isolates harbored aacA4-catB8-aadAI (2 300 bp) and 8 harbored aacCl-orX-orfX-orX'-aadAla (3 000 bp ) . Conclusion The presence of OXA-23 carbapenermase and class Ⅰ integrons are correlated with Acinetobacter baumannii resistant to carbapenems and multi-drug resistance.
2.Antiproliferation and apoptosis of K562 cells by Astragalus Mongholicus Lectin
Yanxia LI ; Qiaojuan YAN ; Yan SUN ; Zhengqiang JIANG ; Lifen ZHU
Chinese Pharmacological Bulletin 2003;0(07):-
Aim To investigate the effects of Astragalus Mongholicus Bunge Lectin (AMML) on tumor cells proliferation,cell cycle and apoptosis by using human leukemia cell line (K562 cells).Methods The antiproliferation effect of AMML on K562 cells was detected by the colorimetric MTT assay.The apoptosis induced by AMML on K562 cells was explored by means of cell morphological and flow cytometry.Results AMML showed strong inhibiton of the growth of K562 cells in a time-and concentration-dependence. After incubation of K562 cells with AMML at a concentration of 60 mg?L-1 for 72 h,the inhibition ratio was 89%.Morphological observation showed that AMML-treated K562 cells displayed outstanding apoptosis characteristics,such as nuclear fragmentation,chromatin condensation. AMML induced significant cell cycle arrest at S phase in K562 cells,and the apoptosis of K562 cells was confirmed by flow cytometry.Conclusion AMML can inhibit the growth of K562 cells through S arrest and induce the apoptosis of K562 cells. Thus,AMML may be valuable for the treatment of cancer.
3.Multi-drug resistance induced by β-1actamases and class Ⅰ integrons with deficiency of Omp genes in Enterobacter cloacae
Fengxia WANG ; Zhidong HU ; Qiaojuan HU ; Bin TIAN ; Hua YANG ; Jing LI
Chinese Journal of Clinical Infectious Diseases 2011;04(6):339-342
Objective To investigate the drug resistance and its distribution induced by β-lactamases and class Ⅰ integrons with the deficiency of Omp genes in Enterobacter cloacaes.Methods Totally 112 strains of Enterobacter cloacaes were isolated during January 2008 and May 2011.The identification of strains was performed by using Vitek-2 Compact automatic system; and antibiotic susceptibility was determined by K-B method.Isolates of E.cloacae were screened for carbapenemases by modified Hodge test,improved three dimensional test and EDTA-meropenem synergy test.Genes encoding AmpC β-lactamase,metallo-β-1actamases (MBLs) and OXA-like β-1actamases were screened by multiple PCR.Single PCR was used to detect ISEcpl,OmpK35/36,NDM-1 and OXA-48.The variable regions of class Ⅰ integrons were amplified and sequenced.Results Among 112 isolates,6 (5.4%) demonstrated positive in the modified Hodge test and 14 ( 12.5% ) were positive in the improved three-dimensional test.No carbapenemases gene was found.There were 29(25.9% ) strains positive for ESBLs genes,ISEcpl was found in the upstream of all the CTX-M-type ESBLs; OXA-1 ESBLs were detected in 2 isolates.AmpC β-lactamase genes were positive in 45 (40.2%) strains,and 82.2% (37/45) were MIR-3 type.Twenty two isolates carried class Ⅰ integrons,and four different cassettes arrangements were identified within 16 strains:9 isolates harbored aadB-aadA2 ( 1 000 bp),5 isolates with dfrAl5 (700 bp),2 isolates with aadAl ( 1 000 bp).One isolate harbored all the above gene cassettes.The deficiency of OmpK35/36 was found in all strains.Conclusion ESBL,AmpC β-lactamase and the deficiency of OmpK35/36 are correlated with the resistance to carbapenems in Enteobacter clocace,and class Ⅰ integrons may also partly account for the multidrug-resistance.
4.Establishment of a primary culture protocol of Mongolian gerbil hepatic stellate cells
Qi LOU ; Wei LI ; Qiaojuan SHI ; Lingqun LU ; Honggang GUO ; Jiangtao DU ; Xiaoying SA
Chinese Journal of Comparative Medicine 2016;26(3):29-34
Objective To investigate the method to isolate and culture hepatic stellate cells ( HSCs) for studying the cellular mechanisms of hepatic frbrosis.Methods HSCs were isolated by nycodenz density gradient centrifugation after the hepatocytes obtained from adult male gebils were digested with pronase, collagenase and DNase, infused via portal vein.The cell viability was determined by trypan blue exclusion test.The purity of HSCs was identified by detectingα-SMA, desmin immunohistochemical staining.Results The yield rate of HSCs was 0.5~1 ×107 per gerbil liver, and the cell viability was more than 90%.The percentage ofα-SMA-positive cells was more than 75%after 3 days primary culture and almost 100% cells were α-SMA and desmin positive in passage culture.Conclusion The successful protocol of primary culture of Mongolian gerbil HSC provide a technical support for research of relevant liver diseases and drug development in the future.
5.Clinical features of coronary artery ectasia in the elderly
Qiaojuan HUANG ; Yan ZHANG ; Xiaolin LI ; Sha LI ; Yuanlin GUO ; Chenggang ZHU ; Ruixia XU ; Lixin JIANG ; Menghua CHEN ; Jianjun LI
Journal of Geriatric Cardiology 2014;(3):185-191
Objective To investigate the incidence, imaging and clinical characteristics in elderly patients with coronary artery ectasia (CAE). Methods A retrospective analysis was conducted on patients with CAE who underwent coronary angiography between January 2006 and December 2012. According to age, the enrolled patients were divided into two groups (elderly group, age≥ 65 years; non-elderly group, age < 65 years). The clinical feature, imaging characteristics and the 5-year survival rate of the two groups were compared.Results The preva-lence of CAE in elderly patients was 0.33%. Patients in elderly group were found to have significantly higher proportion of female (30.1%vs. 10.1%,P< 0.001), three-vessel disease (60.5%vs. 45.2%,P = 0.003) and localized ectasia (55.0%vs. 40.2%,P = 0.003). In addition, body mass index (20.90 ± 2.71 kg/m2vs. 22.31 ± 2.98 kg/m2,P < 0.001) and percentage of current smokers (45.0%vs. 64.6%,P < 0.001) were significantly lower in elderly group. Cumulative survival curves demonstrated reduced 5-year cumulative survival at the follow-up in the elderly group compared with the non-elderly group (88.0%vs. 96.0%,P = 0.002). But the 5-year event free survival rate failed to show a significant difference between the two groups (31.0%vs. 35.0%,P= 0.311).ConclusionThe prevalence of CAE in elderly patients was 0.33%, which was about 1/3 of the entire numbers of CAE patients. There were significant differences between the elderly and the non-elderly patients with CAE in terms of coronary artery disease risk factors and coronary artery ectatic characteristics. CAE might be asso-ciated with increased mortality risk in the elderly.
6.The use of percutaneous endoscopic gastrostomy in advanced nasopharyngeal carcinoma
Yun XU ; Jin LIN ; Lu HAN ; Qiaojuan GUO ; Wei ZHANG ; He HUANG ; Rui LI ; Shaojun LIN ; Jianji PAN
China Oncology 2013;(12):989-994
Background and purpose:Nasopharyngeal carcinoma usually occurs in people of states of the Southern China. Chemoradiotherapy plays an important role in the therapy of advanced nasopharyngeal carcinoma. However, chemoradiotherapy causes more toxic side effects than radiation therapy alone, which affects the therapy. Now symptomatic treatment and nutrition supports are common ways in the clinic in order to improve the tolerance of patients for the therapy, but with little effect. To evaluate the clinical significance of percutaneous endoscopic gastrostomy (PEG) in advanced nasopharyngeal carcinoma. Methods: From Oct. 2010 to Jun. 2012, a total of 71 patients with advanced nasopharyngeal carcinoma who received PEG before chemoradiotherapy were enrolled. During chemoradiotherapy, gastrostomy diet and nursing were supplied, adverse events, tolerance and nutrition indicators including weight and alcohol of human albumin were detected as well. Results:PEG were performed successfully on 68 patients, but failed in the other 3 patients. Of the 68 patients, 4 have not received concurrent chemotherapy because of liver metastases and liver function damage, 51 of the remaining 64 patients could completely ifnished 3 cycles of concurrent chemotherapy, with the completion rate of concurrent chemotherapy at 79.69%. The weight change ranged from-11.86%to 0.83%, with a mean value of-5.32%±2.99%. Paired-sample t test of human albumin before and after the treatment showed no significant difference (P=0.742). Grade Ⅱ radioactive oral cavity mucositis appeared in 60.29%patients (41/68), and 22.06%patients (15/68) suffered gradeⅢradioactive oral cavity mucositis.Conclusion:For patients with advanced nasopharyngeal carcinoma, preventative PEG improved the tolerance of chemoradiotherapy, reduce the incidence of adverse events. The period of therapy interruption caused by sever adverse event were shortened as well, PEG also increased the completion rate of concurrent chemotherapy. Nutritional status and living quality of patients are improved. In addition, PEG is a safe, economic and simple method.
7.Improvement of catalytic capability of Paecilomyces thermophila J18 thermostable beta-1,3-1,4-glucanase under acidic condition by directed evolution.
Yinan LI ; Huiyong JIA ; Qiaojuan YAN ; Zhengqiang JIANG ; Shaoqing YANG
Chinese Journal of Biotechnology 2011;27(12):1797-1804
Directed evolution was used to improve the performance of beta-1,3-1,4-glucanase (designated as PtLicl6A) from Paecilomyces thermophila J18 under acidic condition. A mutant library was constructed by error-prone PCR and DNA shuffling, and positive clones were screened by Congo red staining. More than 1 500 mutants were selected. One mutant (PtLic16AM1) exhibited an optimal activity at pH 5.5, while the optimal pH of the wild-type enzyme was 7.0. The mutant PtLic16AM1 kept the high specific activity and thermotolerence of the wild-type enzyme. Sequence analysis revealed that the mutant enzyme has four sense substitutions which caused four amino acid substitutions - namely T58S, Y110N, G195E and D221G.. Homology modeling showed that among the four amino acid substitutions, Y110N was near the active site of the enzyme, while the other three was distant. T58S and G195E may play key roles in the change of optimal pH. This study provided a new perspective of obtaining applicable 3-1,3-1,4-glucanase for industrial use.
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enzymology
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8.Design and application of the machine for cardiopulmonary resuscitation based on scissor lift principle without back plate
Xingwei HUANG ; Qiaojuan LI ; Yayan SU
Chinese Critical Care Medicine 2020;32(2):235-237
Cardiopulmonary resuscitation (CPR) guidelines emphasize that external chest compression should be started as early as possible during CPR. In addition to manual hand compressions, the machine for CPR can be used instead. However traditional machines for CPR take a lot of time toinstall, and is not conducive to the early initiation of chest compressions. So the medical staff of the emergency department of Mindong Hospital Affiliated to Fujian Medical University designed a new type of machine for CPR based on scissor lift principle without back plate. The design has obtained the national utility model patent. This patented product with flexible lifting and accurate placement is easy to install and fix, and can overcome the drawbacks of conventional machines that are uneasy to install, thus ensuring the implementation of high quality CPR.