Abstract： Objective　To analyze the species distribution of microorganisms in culture tubes reported positive byBACTEC™ MGIT960 (hereafter referred to as "MGIT960") after species identification using matrix-assisted laser desorption/ionization time of flight massspectrometry (MALDI-TOF MS) technique. Methods　From 2021 to 2022, a total of 2 662 positive tubes reported by the MGIT 960 instrument at Tuberculosis Reference Laboratory of Tianjin Center for Tuberculosis Control were collected. Liquid cultures were independently inoculated to blood plate and neutral L-J medium, and the resulting isolate strains were identified using the MALDI-TOF MS method. According to the MALDI-TOF MS results, the non-repetitive results of the same patient on the same culture medium were analyzed for the composition ratio of strain distribution. For the strains not identified by MALDI-TOF MS, 38 strains were selected for 16S rRNA gene sequencing. Results　A total of 605 isolates were obtained from blood plates, and 501 of those were analyzed. Among them, Mycobacterium accounted for 17.76% (89/501), predominant by Mycobacterium abscess 10.18% (51/501) and Mycobacterium fortuitum 3.19% (16/501). Bacteria other than Mycobacterium accounted for 68.06% (341/501), with the main ones being Nocardia farcinica 15.57% (78/501), Gordonia sputa 9.38% (47/501) and Gordonia bronchialis 7.58% (38/501). There were 71 unidentifiable strains, making up 14.17% (71/501). A total of 2 378 strains were isolated from neutral L-J mediums, 1 748 of which were used in the incoming analysis. Among these, 78.72% (1 376/1 748) were Mycobacterium, 60.53% (1 058/1 748) were Mycobacterium tuberculosis (MTB), 4.69% (82/1 748) were Mycobacterium chimaer intracellulare group and 3.55% (62/1 748) were Mycobacterium Lentiflavum. Bacteria other than Mycobacterium accounted for 17.11% (299/1 748) in neutral L-J medium isolates, with Nocardia farcinica 4.35% (76/1 748), Gordonia sputa 2.69% (47/1 748) and Gordonia bronchialis 2.12% (37/1 748) as the main species. There were 73 strains that couldn't be identified, comprising 4.18% (73/1 748). The 38 strains that not identified by MALDI-TOF MS were all found to be Actinobacteria and Firmicutes by sequencing. Conclusions　A variety of nontuberculous Mycobacterium and bacteria other than Mycobacterium were found in the positive culture tubes reported by the MGIT960 instrument, most of which could be quickly identified by mass spectrometry. Bacteria other than Mycobacterium are mainly Nocardia and Gordonia, which should be paid attention to in differential diagnosis.

Abstract: Objective　To analyze the clinical characteristics of Chlamydia psittaci pneumonia and improve the diagnosis and treatment skills of clinicians on this disease. Methods The clinical data of thirty-nine Chlamydia psittaci pneumonia cases detected by metagenomic next-generation sequencing (mNGS) from September 2020 to January 2022 at the Affiliated Hospital of Southwest Medical University were retrospectively analyzed. Results There was a history of poultry exposure in 89.7%(35 cases) of the patients. The most common clinical manifestations were high fever (92.3%, 36), cough (76.9%,30), muscle soreness (48.7%,19), headache (38.5%,15), etc. Laboratory examinations showed 76.9% of patients had a normal leukocyte count, and 76.9% had decreased lymphocyte count, often accompanied by elevated C-reactive protein (100%), procalcitonin (97.4%), interleukin-6 (95.8%), interleukin-10 (95.8%), alanine aminotransferase (74.4%), and aspartate aminotransferase (84.6%). Univariate analysis indicated that there were statistically significant differences in the levels of aspartate transaminase, blood urea nitrogen, C-reactive protein, and procalcitonin between severe pneumonia patients and non-severe pneumonia patients（P<0.05）. Multivariate logistic regression analysis showed that an elevated blood urea nitrogen (OR=4.899) had guiding significance for predicting the occurrence of severe pneumonia. Bronchoscopy examination showed no abnormalities in 53.6% of the patients. The imaging manifestations of pulmonary lesions were mainly lobar pneumonia (61.5%) and air bronchograms (94.9%). Therapeutically, it was sensitive to tetracyclines, macrocyclic lactones, and fluoroquinolones. A total of 84.6%(33 cases) of the patients were cured and discharged from the hospital at the end of the treatment. Conclusion Chlamydia psittaci pneumonia is a zoonotic disease that can be detected by mNGS. An elevated blood urea nitrogen level has guiding significance for predicting the occurrence of severe pneumonia. Empirically-selected regimens based on doxycycline are effective for the treatment of Chlamydia psittaci pneumonia.

Objectives To explore the associations between drug efflux pump gene expression and phenotypic drug resistance as well as gene mutation patterns related to drug resistance of Mycobacterium tuberculosis.Methods Forty-five Mycobacterium tuberculosis isolates resistant to one or more of drugs including isoniazid, rifampicin, streptomycin and ethambutol, and 26 isolates all sensitive to the above four drugs from Tianjin Tuberculosis Control Institute in 2007 were involved in this study. Direct sequencing was applied to detect the mutations in the corresponding resistance genes(isoniazid:katG, inhA, oxyR-ahpC, ndh, rifampicin:rpoB, streptomycin:rpsL, rrs, and ethambutol:embB, embC and embA). After RNA extration and reverse transcription, real-time PCR was conducted to assess the expressions of putative drug efflux pump genes Rv1410c, Rv2136c, Rv0783c and Rv2136c, and Students' t test and ANOVA analysis were used to analyze the expression differences in Mycobacterium tuberculosis with different phenotypic drug resistance and drug resistance related gene mutation patterns.Results Compared to pan-sensitive isolates[(5.67±3.29)×10-5], Rv1410c showed higher expression in streptomycin[(8.48±6.33)×10-5, t'=2.18, P<0.05], isoniazid[(8.43±6.38)×10-5, t'=2.20, P<0.05], rifampicin[(9.59±7.27)×10-5, t'=2.29, P<0.05], multi-drug[(10.37±7.86)×10-5, t'=2.34, P<0.05] resistant isolates, and in isoniazid + streptomycin resistant isolates[(9.39±6.81)×10-5, t'=2.43, P<0.05];Rv2136c showed higher expression in isoniazid resistant[(3.51±2.43)×10-5, t'=2.03, P<0.05], multidrug-resistant isolates[(4.21±2.94)×10-5, t'=2.22, P<0.05] and resistant to isoniazid+streptomycin[(3.81±2.46)×10-5, t'=2.28, P<0.05] isolates . The expression of Rv0783c in rifampicin resistant isolates with rpoB 531 mutations [(5.41±3.03)×10-6] was higher than those with wild type of rpoB 531[(2.29±1.62)×10-6, t=2.81, P<0.05].Conclusions The expression of Rv1410c and Rv2136c are associated with mutiple-drug resistance of Mycobacterium tuberculosis.The expression of Rv0783c in rifampicin resistant isolates is associated with mutation in rpoB 531.

ObjectiveTo investigate the prevalence and distribution characteristics of dental fluorosis of children aged 8 - 12 in Wushan and Fengjie counties of Chongqing and to provide a scientific basis for prevention and control of the disease.MethodsTwenty townships(towns) in Fengjie county and 18 in Wushan county were selected as survey points by random cluster sampling in 2010.Dental fluorosis of all the children aged 8 - 12 was examined with Dean index.The detection rate of children's dental fluorosis,defect rate and dental fluorosis index were compared between the two counties.Results Totally 38 209 children aged 8 - 12 were investigated.The total detection rate of dental fluorosis was 43.09％( 16 466/38 209) in the two counties.The detection rates of dental fluorosis in Wushan and Fengjie were 48.98％ (9397/19 186)and 37.16％(7069/19 023),respectively,and the difference was statistically significant(x2 =544.03,P ＜ 0.01 ).Total detection rates of dental fluorosis of the five age groups(8,9,10,11,and 12-year-old age groups) were 32.52％(2157/6632),40.07％(2672/6668),43.67％(3420/7831 ),46.01％ (3861/8391) and 50.14％ (4356/8687),respectively,and the difference was statistically significant (x2 =510.50,P ＜ 0.01),Dental fluorosis indexes in Wushan and Fengjie were 0.713 and 0.485,respectively.Defect rates of dental fluorosis in Wushan and Fengjie were 4.05％ (777/19 186) and 1.57％(298/19 023),respectively.Conclusions The total detection rate of dental fluorosis of the two counties is still high,which gradually increases with age.Wushan is still an endemic area of dental fluorosis,and Fengjie is at the edge of the

Objective To investigate the causes of arterial reocclusion in diabetic feet patients after endovascular treatment and its remedial measures.Methods From January 2009 to October 2013,clinical data of 371 arterial reocclusion of diabetic feet patients after endovascular treatment in Tianjin First Central Hospital were reviewed retrospectively.We summarized the causes of reocclusion,treatment methods and the short term results.Results According to the Trans-Alantic Inter-Society Consensus (TASC) Ⅱ grading standards,the first time when the endovascular treatment started there were 37 cases of grade A,85 cases of grade B,143 cases of grade C,106 cases of grade D.Arterial re-occlusion developed from one day to 36 months,averaging at (21 ± 8) months.Causes of re-occlusion included intimal hyperplasia in 263 cases (70.9％),thrombosis in 65 cases (17.5％),dissection in 19 cases (5.1％),stent fracture in 17 cases (4.6％),vascular rupture in 7 cases (1.9％).Remedial therapy adopted for arterial reocclusion was repeated endovascular treatment in 327 cases (88.1％),arterial bypass surgery in 23 cases (6.2％),conservative treatment in 13 cases (3.5％),amputation (cut toe) in 4 cases (1.1％),4 cases (1.1％) died perioperatively.275 cases were followed up for 1 to 36 months,the average was (13 ± 8) months.patency rate was 82.9％,71.3％ and 63.0％ at 6 months,1 year and 2 years.Amputation rate was 1.1％,1.8％ and 2.5％ at 6 months,1 year and 2 years.Conclusions Intimal hyperplasia is to blame for arterial reocclusion after endovascular treatment of diabetic foot.In this case most patients still can benefit from second time endovascular treatment,with a satisfactory short term patency rate.

Objective To explore the feasibility of detecting atherosclerosis with 7.0T MR and Micro-PET. Methods Ten 46-week-old ApoE-/- mice with high lipid diet for 6 months were selected to establish atherosclerosis models. Among them, 5 mice underwent MRI before and 12 h, 24 h, 36 h after injection of SPIO, respectively, and the other 5 mice were injected with ~(18)F-fluorodeoxyglucose (~(18)F-FDG) through tail vein and observed with Micro-PET after 1 h, 2 h and 3 h. The specimens of abdominal aorta were taken for pathologic examination. Results Atherosclerotic plaques were observed in all animals with 7.0T MRI after 6 months high lipid diet. Thirty-six hours after the injection of SPIO, the high signal rings were thinner and the lumen of blood vessels were wider than those before injection on T2WI. Radioactive concentration was observed in abdominal aorta and both sides of iliac artery 3 h after the injection of ~(18)F-fluorodeoxyglucose (~(18)F-FDG). Pathological examination showed the formation of atherosclerotic plaques and the aggregation of the macrophages. Conclusion 7.0T MRI and Micro-PET can be used to observe the macrophage-rich plaque and to judge the vulnerability of plaque, thus provide theoretical basis for early detection, diagnosis and treatment of atherosclerosis.

Aims HDAC2 gene was cloned into pEGFP-C2 vector to explore the efficiency of the plasmid trans-fection in renal fibroblasts COS-7 cells to identify the expression of both mRNA and protein levels and to ob-serve the distribution of the protein. Methods The HDAC2 cDNA was amlified by PCR and cut with the double enzyme Xho I and BamH I, then inserted into the eukaryotic expression vector pEGFP-C2 with T4 en-zyme. The recombinant vector was verified by PCR, restriction enzymes cut and sequencing identification. Then it was transfected into COS-7 cells and the ex-pression of pEGFP-C2-HDAC2 was monitored by fluo-
rescence microscope and PCR. Results Fragments of HDAC2 could be seen after dealt with double diges-tion, and GFP could also be detected in the transfected COS-7 cells. HDAC2 gene expression could be detec-ted by PCR and Western blot. The fusion expression of pEGFP-C2-HDAC2 could be detected by Western blot. Conclusion Eukaryotic expression vector of HDAC2 has been successfully constructed, the fusion expres-sion of HDAC2 and GFP protein can be detected in COS-7 cells.

Objective To explore the clinical efficacy and satety of LFK-SLT30 semiconductor laser combined with polidocanol for the treatment of varicose veins of the lower extremities.Methods The clinical data of 105 patients treated by traditional surgery (surgery group) and 113 patients with endovascular laser treatment (EVLT) combined with polidocanol (combination group) were retrospectively analyzed from Apr 2013 to Apr 2015.Results The operative time [(50 ± 12) min vs.(70 ±10)min] and blood loss [(19 ± 6)ml vs.(41 ± 8)ml] between combination group and surgery group were significantly different (P ＜ 0.05).The rate of complications in surgery group was significantly higher than that in the combination group[15.2％ (16/105)vs.6.3％ (7/113),x2 =4.717,P =0.030].The overall 1',2' and 3 year follow-up rate was 85.3％ (186/218),76.6％ (167/218),and 60.6％ (132/218).The average follow up was (20 ± 13)months.No significant difference existed in the rate of recurrence [0 vs.3.5％(4/113),x2 =3.786,P=0.123] between the two groups.Conclusions EVLT combined with foam sclerotherapy is as effective as surgery,while resulting in less complications,less invasive,safer and more effective for the treatment of varicose veins of the lower extremities.

Objective To establish abdominal aortic dissection model in ApoE-/-mice, and to evaluate the ability of 7.0T MR to detect the abdominal aortic artery aneurysms in ApoE-/-mice in vivo. Methods ApoE-/-mice aged 10 months were infused with angiotensin Ⅱ with 14 days Osmotic minipump after 10 weeks of high lipid diet. Two different doses of angiotensin Ⅱ were given to mice, i.e. 1000 ng/(kg·min) and 500 ng/(kg·min), respectively. The contrast group was infused with saline water. The abdominal aortic artery was observed in vivo with MR before and within 14 days infusion. At last, the pathological changes of the abdominal artery were compared with MRI findings. Results After 6 or 7 days higher dose of angiotensin Ⅱ infusion, aortic dissection was seen. MR T2WI showed crescent-shaped high signal in the vessel wall of one side，the pathological study identified the hematoma between media and adventitia. Abdominal aortic dissection aneurysms were also found in the mice 13 or 14 days after lower dose of angiotensin Ⅱ infusion, which were consistent with pathological studies. Besides, the signal of the vessel wall was significantly higher in both T2WI and PDWI sequences. There was excellent agreement between MR and histopathology. 〖WTHZ〗 Conclusion Abdominal aortic dissection aneurysms model can be successfully established with different doses (1000 ng/(kg·min) and 500 ng/(kg·min)) of angiotensin Ⅱ infusion into ApoE-/-mice fed with high lipid diet. High-resolution MR is able to visualize the abdominal aortic dissection aneurysm formation in vivo.

Objective To compare the efficacy and efficiency of simulation-based training of flexible fibreoptic intubation in novices with virtual reality simulator.Methods A total of 46 anaesthesia residents in their first stage of training in anaesthesiology with no experience in flexible fibreoptic intubation at Peking University People's Hospital were enrolled in the study,and were divided into 2 groups randomly,which were virtual reality simulator group (group S,n=23) and manikin group (group M,n=23).The group S was then trained for 25 times on simulator,while the group M did the same processes on manikin.After training,participants in both groups had their performance assessed with the fibrescope evaluated through the oral route using a simulation manikin,who were instructed to attempt to advance the fibrescope 5 consecutive times to view the carina in the shortest amount of time.The time required to view the carina of each practice during training in both groups were recorded as pooled data to construct group learning curves with the application of SPSS 20.0.By using repeated measures analysis of variance and Ttest,the procedure time and global rating scale (GRS) of fibreoptic bronchoscope manipulation ability were compared between groups,so did the participant's confidence between before and after the training both within-subjects and between-subjects.Results The plateaus in the learning curves were achieved after 19 (15,26) practice sessions in group S and 24 (19,31) in group M,respectively.There was no significant difference in the procedure time [(13.7 ± 6.6) s and (11.9 ±4.1) s] and GRS [(3.9 ±0.4) vs.(3.7 ±0.3)]between groups.There were significant increases in participant's confidences in both groups after training [group S:(1.8 ± 0.5) vs.(3.9 ± 0.6),t=10.928,P=0.000;group M:(2.0 ± 0.7) vs.(3.9 ± 0.5),t=15.306,P=0.000],but there was no significant difference between groups.Conclusion The simulation-based training of flexible fibreoptic intubation in novices with virtual reality simulator is more efficient than the one with manikin,but the similar effects can be achieved in both modalities,after adequate trainings.In the related training a balance between time cost and economic cost should be considered and the appropriate teaching methods and forms should be taken.