1.Antibiotic Resistance and Genotyping of Pseudomonas aeruginosa Isolated from Burn Unit by Pulsed-field Gel Electrophoresis
Xihao HU ; Xiaomin XU ; Chunguang JIN ; Lina CHEN
Chinese Journal of Nosocomiology 1994;0(04):-
OBJECTIVE To analyze antibiotic resistance pattern and use pulsed-field gel electrophoresis(PFGE) to study the molecular epidemiology of Pseudomonas aeruginosa isolated from burn unit. METHODS P.aeruginosa had been isolated and tested by K-B method from clinical samples and antibiotic resistance was analyzed and studied retrospectively. RESULTS The drug resistance of P.aeruginosa to nine antibiotics was high,the multiple drug resistance rate was 30%. CONCLUSIONS The resistance rates to commonly used antibacterials in P.aeruginosa are high and the resistance pattern is wide.PEGE is a better genotyping method to study molecular epidemiology and analytic homology.
2.A Clinical Acinetobacter baumannii Strain Carrying Beta-lactamases and Aminoglycoside-modifying Enzyme Genes
Xiaomin XU ; Xihao HU ; Zuhuang MI ; Liangang MAO ; Lin CHEN
Chinese Journal of Nosocomiology 1994;0(04):-
OBJECTIVE To analyze the cause of Acinetobacter baumannii resistance to ?-lactam and the aminoglycoside-modifying antibacterials. METHODS Three-dimensional test was used to analyze and classify the ?-lactamases. Proper primers was used to do PCR and determined by sequencing. RESULTS A. baumannii clinical isolate harbored blaOXA2-23,blaTEM and blaADC genes and aac(3)-Ⅰ,aac(6')-Ⅰb and ant(3″)-Ⅰ aminoglycoside-modifying enzyme genes. CONCLUSIONS An A. baumannii strain which carries TEM,OXA-23,ADC ?-lactams and aac(3)-Ⅰ,aac(6')-Ⅰb,ant(3″)-Ⅰ aminoglycoside-modifying enzyme genes is detected.
3.Current update on combined hepatocellular and cholangiocarcinoma
Dongming LIU ; Lu CHEN ; Yao TIAN ; Xihao ZHANG ; Qiang LI
Tianjin Medical Journal 2016;44(9):1181-1184
Combined hepatocellular and cholangiocarcinoma (HCC-CC) is a rare primary hepatic neoplasm (PHN) with features of both hepatocellular and biliary differentiation. Hepatitis B and hepatitis C are the major causes of HCC-CC. Surgical treatment is the main therapeutic method for HCC-CC. For patients with unresectable lesions, curative or palliative locoregional therapy is applied, including radiofrequency ablation (RFA), transarterial chemoembolization (TACE) and supportive treatment. Because of the rare occurrence and ambiguous clinical features of HCC-CC, it is most often misdiagnosed with the other two types of primary liver cancer. Thus, the realization of the current progress of combined hepatocellular and cholangiocarcinoma is particularly important for us. This article aims to summarize the epidemiology and clinical futures, the treatment and prognosis, the progress of genetics and molecular analysis of HCC-CC.
4.Study of great omentum combined with medical obturation glue in the prevention of thoracic cavity anastomotic leakage
Ying CHEN ; Wanli LIN ; Haiquan HE ; Xihao XIE ; Fengyuan PENG ; Cong LAN
Clinical Medicine of China 2013;29(8):839-841
Objective To investigate the effect of great omentum combined with medical obturation glue on preventing thoracic cavity anastomotic leakage.Methods From August 2008 to September 2012,560 patients with esophageal gastric cardial carcinoma were enrolled and divided into two groups:the regular group (n =280) and the experimental group (n =280).In the regular group,anastomosis was reinforced with interrupted mattress sutures after esophageal gastric anastomosis was stapled.In the experimental group,anastomosis was covered with great omentum and medical obturation glue was sprayed to conglutinate after reinforced with interrupted mattress sutures.After that,gastric corpus was fixed upon the thoracic aorta and posterior chest wall.The clinical effects of the two groups were compared.Results Intrathoracic anastomotic leakage occurred in 8 cases (2.86%(8/280)) of the regular group,including 7 cases with symptomatic leakage and 1 case with asymptomatic loculate leakage.Seven patients were cured with conservative treatment and 1 patient with severe infection left hospital without cure.Average length of hospital stay was (55.6 ± 30.5) days postoperatively.Anastomotic stenosis occurred in 11 patients (3.93%,11/280).In the experimental group,one patient (0.36%,1/280) with asymptomatic loculate leakage was hospitalized for 20 days,and finally cured and discharged.8 cases with anastomotic stenosis occurred in the experimental group (2.86%,8/280).There was statistic difference in the rate of intrathoracic anastomotic leakage between the two groups (P =0.044),but there was no statistic difference in anastomotic stenosis between the two groups (P =0.484).Conclusion The technique of great omentum combined with medical obturation glue for preventing thoracic cavity anastomotic leakage,which is easy to perform,can obviously decrease the occurrence and attenuate the symptom of intrathoracic anastomotic leakage,and anastomotic stenosis increases unobviously.It also can shorten the length of hospital stay and is worthy of clinical promotion.
5.Application of CRISPR/Cas9 genome editing technology in hereditary retinal diseases
Xihao SUN ; Shibo TANG ; Jiansu CHEN
Chinese Journal of Experimental Ophthalmology 2023;41(9):925-930
Several mutant genes for inherited retinal diseases have been identified, but effective treatments are still lacking.The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) system can edit human genomic DNA by nonhomologous end joining or homology-directed repair, offering more possibilities for the treatment of hereditary retinal diseases.CRISPR/Cas9 not only can genetically correct patient-derived induced pluripotent stem cells (iPSCs) to observe their differentiation into retinal cells thereby, thereby exploring the pathogenesis of the disease and implementing cell therapy, but can also be delivered to the body via vectors and directly act on target cells to achieve in vivo gene editing.CRISPR/Cas9 gene editing technology in hereditary retinal diseases has been mainly used in retinitis pigmentosa, hereditary X-linked juvenile retinoschisis, and Leber congenital amaurosis 10, of which the in vitro application of CRISPR/Cas9 for Leber congenital amaurosis 10 has entered the clinical trial stage.In this paper, we reviewed the mechanism and key advances of CRISPR/Cas9 and provided an overview of gene editing in IRDs.
6.Impact of ambient ozone exposure on death from cardiovascular and cerebrovascular diseases in Minhang District, Shanghai
Jie LIU ; Jun HUANG ; Xiaowen XU ; Lingyan ZHEN ; Linli CHEN ; Shengjie YING ; Xihao DU
Journal of Environmental and Occupational Medicine 2024;41(5):467-473
Background Ozone (O3) pollution has gradually become a primary problem of air pollution in recent years. Conducting epidemiological studies on the correlation between O3 concentration variation and risk of cardiovascular and cerebrovascular diseases can provide reference data for O3 risk assessment and related policy making. Objective To quantitatively evaluate the effects of O3 exposure on mortalities of cardiovascular and cerebrovascular diseases among residents in Minhang District, Shanghai. Methods Data of mortalities of cardiovascular and cerebrovascular diseases, air pollutants, and meteorological factors in Minhang District of Shanghai from January 1, 2016 to December 31, 2021 were collected. Associations between O3 concentration and the mortalities due to total cardiovascular and cerebrovascular diseases, coronary heart disease, and stroke were analyzed by generalized additive models with a quasi Poisson distribution with different lag patterns, such as current day effect (lag0), single-day lag effects (lag1-lag3), and cumulative lag effects (lag01-lag03). The subgroup analyses of age, sex, and season were conducted. Furthermore, temperature was divided into low, middle, and high levels based on the 25th percentile (P25) and the 75th percentile (P75) to perform hierarchical analyses. Increased excess risks (ER) of death from target diseases caused by a 10 µg·m−3 increase in daily maximum 8 h concentration of O3 (O3-8 h) and their 95% confidence intervals (CI) were used to indicate the effects of O3. Results The associations between O3 and the risks of death from cardiovascular and cerebrovascular diseases were statistically significant at lag2, lag3, lag02, and lag03 (P<0.05), with the greatest effect size observed at lag03. The ER values of death from cardiovascular and cerebrovascular diseases in general population, male residents, and people aged 65 years and older, from coronary heart disease in male residents, and from stroke in general population increased by 1.02% (95%CI: 0.36%, 1.69%), 1.40% (95%CI: 0.47%, 2.34%), 0.87% (95%CI: 0.19%, 1.55%), 1.96% (95%CI: 0.49%, 3.44%), and 1.02% (95%CI: 0.07%, 1.98%) for a 10 µg·m−3 increase in O3-8 h concentration at lag03, respectively. During the warm season (from April 1 to September 30), the ER values of death from cardiovascular and cerebrovascular diseases and coronary heart disease per 10 µg·m−3 increase in O3 were 1.18% (95%CI: 0.33%, 3.33%) and 2.69% (95%CI: 0.39%, 5.03%), while the O3 effect was only statistically significant on cardiovascular and cerebrovascular diseases during the cold season (from October 1 to March 31 next year). At the middle and high temperature levels, the ER values of death from cardiovascular and cerebrovascular diseases increased by 1.63% (95%CI: 0.32%, 2.96%) and 1.14% (95%CI: 0.17%, 2.12%) respectively. The two-pollutant models showed similar results after including other pollutants (carbon monoxide, nitrogen dioxide, sulfur dioxide, fine particulate matter, or inhalable particulate matter). Conclusion Ambient O3 pollution may increase the mortality risks of cardiovascular and cerebrovascular diseases, coronary heart disease, and stroke in Minhang District of Shanghai.
7.Influencing factors and establishment of a prediction model for the tumor regression after neoadjuvant chemoradiotherapy in locally advanced rectal cancer
Zhiyu LIU ; Dong XU ; Xihao CHEN ; Jipeng LI
China Oncology 2024;34(2):191-200
Background and purpose:The standard therapy for locally advanced rectal cancer(LARC)is neoadjuvant chemoradiotherapy(nCRT)followed by surgery.NCRT can make the tumor regress and downstage,and increase the R0 resection rate.However,individual differences in rectal cancer are large,and some patients respond poorly to nCRT and cannot benefit from nCRT.Therefore,it is necessary to establish effective screening measures to identify patients with poor response to nCRT.This study aimed to analyze the influencing factors of nCRT for LARC and construct the tumor regression prediction model.Methods:Data of 158 LARC patients who underwent total mesenteric resection after receiving nCRT at the First Hospital Affiliated to Air Force Medical University from January 2016 to December 2020 were collected.Baseline clinical indicators before nCRT were collected,including laboratory examination,tumor markers and magnetic resonance imaging(MRI).According to the tumor size reported by MRI before and after nCRT,Response Evaluation Criteria in Solid Tumors(RECIST)was used to evaluate the extent of tumor regression after nCRT.After receiver operating characteristic(ROC)curve was used to standardize the clinical baseline indicators,logistic regression analysis was carried out to screen the factors affecting the tumor regression.The tumor regression prediction model was constructed by logistic regression,and the performance of the model was evaluated based on decision curve analysis(DCA)and the calibration curve.The accuracy of the model was tested by 10-fold cross-validation.Results:This retrospective cohort study enrolled 158 patients,in which,98 patients achieved complete response(CR)or partial response(PR).The objective response rate was 62%.Sixty patients had poor response to nCRT,either stable disease(SD)or progressive disease(PD).Multivariate logistic regression analysis showed that tumor diameter before treatment(P<0.001),time to surgery after nCRT(P = 0.006),D-dimer(P = 0.010),prognostic nutrition index(PNI)(P = 0.035),carcinoembryonic antigen(CEA)(P = 0.004)and extramural vascular invasion(EMVI)(P = 0.026)were significantly related to tumor regression after nCRT.The area under ROC curve(AUC)of tumor regression after nCRT prediction model for LARC was 0.84(95%CI:0.780-0.899),sensitivity was 85.0%,and specificity was 72.4%.In the calibration curve,the predicted results were in good agreement with the actual results,and the prediction accuracy was good.The DCA showed that the tumor regression prediction model could bring clinical net benefit to diagnosis.Conclusion:Tumor diameter before treatment,time to surgery after nCRT,D-dimer,PNI,CEA and EMVI are independent risk factors for the tumor regression after nCRT in LARC patients.The tumor regression prediction model based on the above factors has good predictive efficacy for the tumor regression after nCRT in LARC patients.
8.Functional discovery and production technology for natural bioactive peptides.
Yanjun WANG ; Shucheng LI ; Changge GUAN ; Dong HE ; Xihao LIAO ; Yi WANG ; Haihong CHEN ; Chong ZHANG ; Xin-Hui XING
Chinese Journal of Biotechnology 2021;37(6):2166-2180
Bioactive peptides play important roles in promoting human health, such as lowering blood pressure, blood sugar and blood lipid, anti-obesity, and anti-cancer. Thus, exploring functional bioactive peptides and developing efficient production technologies are of crucial importance. Herein, we review the development of function discovery and production technology for natural bioactive peptides. Presently, the top-down and bottom-up approaches are mainly used for the function discovery and production of natural active peptides. The top-down approach includes the direct extraction and identification for functional discovery, and the direct extraction, enzymatic hydrolysis and microbial fermentation for production. The bottom-up approach includes the polypeptide modification and database mining for functional discovery, and the chemical synthesis, enzyme synthesis, recombinant expression and cell-free synthesis for production. The top-down approach is usually associated with complicated process, lower efficiency, higher cost, harder quality control, and uncertain functionality, while the bottom-up approach is more suitable for the development of peptide drugs but difficult to be used for functional foods. With the technology development of sequencing and mass spectrometry, it is easier to obtain the proteomic information of various organisms at the molecular level. Based on the proteomic information, the top-down and bottom-up approaches can be combined to overcome the disadvantages of using these two approaches alone, thus providing a new strategy for the rapid development and production of natural active peptides.
Fermentation
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Humans
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Mass Spectrometry
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Peptides/metabolism*
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Proteomics
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Technology