Animals ; SARS-CoV-2 ; Antibodies, Neutralizing ; Macaca mulatta ; COVID-19/prevention & control* ; Antibodies, Viral ; Vaccines

Objective:To investigate the CT features of lepidic predominant adenocarcinoma (LPA) and other pathological subtypes in early-stage invasive pulmonary adenocarcinoma appearing as ground glass nodule (GGN); and to provide imaging-derived information for the clinical management of GGN.Methods:The clinical and CT data of patients with early-stage invasive pulmonary adenocarcinoma in the First Medical Center of PLA General Hospital from January to December 2019 were retrospectively reviewed. All patients presented with pure GGNs or mixed GGNs with a consolidation-to-tumor ratio (CTR)<0.5, with the pathological results confirmed by surgery. GGNs were divided into LPA and non-LPA (n-LPA) groups according to pathological subtypes. Univariate analysis was used to compare the clinical data and CT characteristics between the two groups. The multivariate analysis was performed for the indicators with statistically significant differences and a multivariate model was generated using the reverse elimination method. The area under the ROC curve (AUC) was used to evaluate the discriminatory power of this model for differentiation of LPA from n-LPA.Results:A total of 630 GGNs from 589 patients were analyzed, with 367 GGNs in LPA group and 263 GGNs in n-LPA group. In univariate analysis, the diameter [(14±5) mm], CT value [(-566±98) HU], and CTR [13.9% (0, 27.3%)] in the LPA group were significantly smaller than those in the n-LPA group [(15±5) mm, (-499±111) HU, 27.8%(7.7%, 40%)], respectively, P<0.05]. The frequency of mGGN, deep lobulation sign, burrs, vascular changes, bronchial changes, and clear tumor-lung interface were significantly higher in the n-LPA group than those in the LPA group ( P<0.05). Multivariate analysis results showed that mean CT values, CTR, deep lobulation sign, burr, vascular changes, and bronchial changes were independent predictors for predicting n-LPA ( P<0.05), which were included in the logistic model. Using the optimal cutoff value of 3.958, the logistic regression model for differentiate LPA from n-LPA had a sensitivity of 76.4%, a specificity of 78.7%, and an area under the curve of 0.840. Conclusion:The CT features are helpful for differentiating lepidic predominant subtype from other subtypes in early-stage invasive pulmonary adenocarcinoma presenting as a GGN.

Objective To analyze the fireworks signs of active pulmonary tuberculosis on CT, improve the understanding of CT findings of active pulmonary tuberculosis, and provide imaging basis for clinical treatment. Methods From January 2009 to December 2015, 26 patients (20 males, 6 females;age 16-72(39 ± 15) years old) with fireworks signs on CT were included, all patients had active pulmonary tuberculosis confirmed by sputum smear, bronchoalveolar lavage, biopsy or surgical specimen. A retrospective analysis of patient′s CT image data including the position, number, pattern of fireworks signs and other associated abnormalities were performed and the imaging features were summarized, pathological correlation with CT images was performed in patients with surgical or biopsy results. Results The fireworks signs on CT could be divided into three types:halo pattern, reversed halo pattern and homogenous pattern, which were 2, 7, 23 cases respectively in this study. Fireworks signs in 9 cases were located in unilateral lung field and 17 cases in bilateral lung field. Distribution of lesions was common bilaterally, mainly in the apical, posterior (apicoposterior) segments of the upper lobes and the superior segments of the lower lobes. Fireworks sign presented as a solitary lesion in 7 cases, 2 lesions in 3 cases, more than 3 lesions in 16 cases. Other pulmonary abnormalities included cavities, consolidation, tree-in-bud sign, pleural effusion, pleural thickening and mediastinal lymphadenopathy. Pathologically, fireworks sign corresponded to caseous granulomas in the bronchioles and alveoli. Conclusion Fireworks sign is one of CT signs of active pulmonary tuberculosis, which formed by the bronchial dissemination of tuberculosis on CT and the granulomas in bronchioles and alveoli on pathology.

Objective To find the invasion-associated clinical and CT risk factors of lung adenocarcinoma presenting as pure ground glass opacity nodule (pGGN) and to calculate odds ratio valve of each independent risk factor, the total risk value(TRV) of each lesion and an alert value for the management of pGGN. Methods From January 2014 to December 2016, 265 patients with 274 lesions pathologically confirmed lung adenocarcinoma with pGGN on CT who had undergone curative resection were included. Patient′s clinical data and CT features of pGGN were collected. CT features included the location, size, density and edge of pGGN, bubble-like sign, intrinsic abnormal air-bronchogram and vascular changes, tumor-lung interface. All lesions were divided into preinvasive groups (74 lesions) and invasive groups (200 lesions) according to the histopathology. Quantitative data were compared between preinvasive and invasive groups using t test or variance analysis (ANOVA) or nonparametric test. Qualitative data were compared between two groups using chi-square test. Logistic regression analysis was performed to evaluate the clinical and imaging independent risk factors of invasiveness. Receiver operating characteristics curve analysis was used to get the optimal cutoff value (alert value) for lesion invasiveness. Results There were statistically significant differences in patient age, lesion size, bubble-like sign, abnormal air-bronchogram, intrinsic vascular changes and tumor-lung interface between preinvasive and invasive groups (P<0.05). Logistic regression analysis showed that bubble-like sign, abnormal air-bronchogram, tumor-lung interface and lesion size were independent risk factors of invasiveness of pGGN, the OR value and 95％CI were 2.145(1.157—3.977), 3.167(1.211—8.281), 3.253(1.444—7.324), 1.175(1.061—1.303), respectively. The ROC curve demonstrated the optimal cutoff of TRV for predicting invasiveness was 3.5 with the sensitivity of 85.5％and specificity of 69.0％. Conclusions TRV can predict the invasiveness of pGGN. Surgical treatment is recommended if TRV is≥3.5.

Objective To analyze the value of abnormal air bronchogram for predicting the invasiveness of lung adenocarcinoma with pure ground-glass nodule (pGGN).Methods From April 2014 to February 2016,157 patients with 165 pGGN lung adenocarcinomas confirmed by surgical pathology were selected.There were 30 pre-invasive lesions (AAH+AIS),39 minimally invasive adenocarcinoma (MIA),and 96 invasive adenocarcinoma (IAC).CT characteristics including lesion size,density,abnormal air bronchogram were recorded.All lesions were divided into two groups:normal group (no air bronchogram or normal air bronchogram) and abnormal air bronchogram group.Chi-square test was used to analyze the difference of pathological subtypes between the two groups.Mann-Whitney rank test was used to analyze the size difference of pGGN between the two groups.Two-independent samples t-test was used to analyze the lesion density difference of pGGN between the two groups.Results Of the 165 lesions,85 were found to have air bronchogram,there were 12 lesions in 30 pre-invasive lesions (AAH+AIS),17 in 39 MIAs,56 in 96 IACs.Abnormal air bronchogram were demonstrated in 61 lesions which was 1 in 30 pre-invasive lesions (IACs+AIS),13 in 39 MIAs and 47 in 96 IACs,significant differences were found between two groups (x2=25.943,P＜0.01).The mean size of the IACs were (10.8±4.2) mm for normal group,(17.0±6.7) mm for abnormal air bronchogram group,the mean density were (-519± 118) HU and (-518± 124) HU,respectively.There was a significant difference in lesion diameter between two groups (Z=-6.197,P＜0.01),but not in density (t=-0.042,P=-0.966).Conclusions Abnormal air bronchogram can be used to predict the invasiveness of pGGN lung adenocarcinoma,and is correlated with lesion size,but not with density.

Objective To evaluate the correlations between CT features and histopathologic subtypes of lung adenocarcinomas presenting as pure ground-glass nodules (pGGN) of 1 cm or less in maximal diameter. Methods CT appearances, pathology and clinical data of 95 patients (97 lesions) who underwent curative resection of lung adenocarcinomas presenting as pGGN≤1 cm in diameter from March 2011 to February 2015 were retrospectively analyzed. Of the 97 lung adenocarcinomas, there were 19 atypical adenomatous hyperplasia (AAH) (19.6%), 31 adenocarcinoma in situ (AIS) (31.9%), 19 minimally invasive adenocarcinoma (MIA) (19.6%) and 28 invasive pulmonary adenocarcinoma (IPA) (28.9%). Fifty (51.5%) were preinvasive (AAH+AIS) and 47 (48.5%) were invasive (MIA+IPA). Lesion size and density were compared among pathologic subtypes using analysis of variance (ANOVA). Lesion size were compared between preinvasive and invasive lesions using 2?independent samples t?test. Lesion location, presence of bubble?like sign, air bronchogram, vessel changes, margin, and tumor?lung interface were compared among histopathologic subtypes using chi?square test. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the cut-off point of size in discriminating preinvasive lesions from invasive lesions. Results Of the 97 lesions, there were no statistically significant differences among histopathologic subtypes in terms of lesion density, presence of bubble?like sign, air?bronchogram, and margin (P>0.05). Mean size of AAH, AIS, MIA and IPA was (0.72 ± 0.19), (0.82 ± 0.14), (0.84 ± 0.11) and (0.85 ± 0.16) cm respectively. There were statistically significant differences among histopathologic subtypes in terms of lesion size (F=3.16, P=0.028). The vessel changes occurred in 2 of AAH, 11 of AIS, 10 of MIA and 17 of IPA. There were statistically significant differences among histopathologic subtypes in terms of vessel changes (χ2=13.22, P=0.004). Lesions with clear tumor?lung interface were in 10 of AAH, 24 of AIS, 17 of MIA, and 26 of IPA. There were statistically significant differences among histopathologic subtypes in terms of tumor?lung interface (χ2=12.67, P=0.005). The optimal cutoff value of lesion size for differentiating preinvasive lesions from invasive lesions was 0.82 cm (sensitivity, 61.7%;specificity, 62.0%). Conclusion Lesion size, vessel changes, and lung?tumor interface may indicate the invasiveness of lung adenocarcinoma presenting as pGGNs of≤1 cm in diameter.

Objective To study on plasmid-mediated quinolone-resistant in Escherichia coli strains isolated from fecal samples of chicken and swine from the nine farms around our country.Methods Antimi-crobial susceptibility testing was carried out by broth microdilution testing,gyrA,gyrB,parC,qnr and aac (6')- Ⅰ b-cr were examined by PCR,and the products were sequenced.Conjugation experiment was carried out to proved that the plasmid-mediated quinolone resistance was transferable.Results In the total 818 animal isolates,qnr and aac genes were detected in 38 (4.6%) and 75 (9.2%) strains.The qnrA,qnrB,and qnrS genes were detected in 1 (0.1%),9 (1.1%) and 28 (3.4%) of the isolates.All isolates were negative for qnrC,qnrD genes.Conclusion There is a close relationship between high level quinolone resistance and plasmid-mediated quinolone resistance.The results of the current study highlight food-producing animals as a potential reservoir of antimicrobial-resistant bacteria and clinically important resistance genes.More attention should be paid to the surveillance of such strains.

Objective To characterize the roles of different quinolone resistance mechanisms in quinolone-resistant Escherichia coli isolates,including different topoisomerase point mutations,efflux pumps and outer membrane proteins.Methotis Through homologous gene recombination methods,different quinolone-resistant mechanisms of E. coli mutants were constructed and the susceptibility changes of these mutants to different antimicrobials were measured.Resuits Efflux pumps AcrAB and outer membrane protein TolC played different roles in different E. coli isolates.Compared with other mechanisms,the mutations in topoisomerases played a dominant role in quinolone resistance.Only the mutations jn parC had no effect on quinolone resistance,which further confirmed parC was the secondary target of quinolones in E.coli.Fluoroquinolone susceptible E.coli would automatically become highly resistant to quinolones after acquiring the point mutations in both gyrA(S83L,D87N)and parC(S80I,A108V),but not requiring the over-expres-sion of efflux.Conclusion The mutations in topoisomerases play a dominant role in E.coli quinolone resistance,and the mutations in both gyrA and parC are required.

Objective To characterized the Salmonella enterica serotype typhimurium isolates recovered during 2002 to 2005 from outpatients in Tongji Hospital, Wuhan China. Methods The 36 isolates from Tongji Hospital were characterized by antimicrobial-susceptibility testing and screened for class Ⅰ integrons, beta-lactamase genes, qnr, aac(6')-Ib-cr and mutations in the quinolone resistance determining regions (QRDRs) by PCR and DNA sequence analysis. All isolates were also characterized by pulsed-fieldgel electrophoresis (PFGE) to determine the genetic relateness among these isolates. Results All isolates displayed multidrug resistance and most of them harbored class Ⅰ integrons. Ciprofloxacin-resistant isolates showed significant difference compared with ciprofloxacin-susceptible isolates after PFGE analysis. All 31 ciprofloxacin resistant isolates carried at least three mutations in the QRDR of GyrA and ParC. Three ciprofloxacin resistant isolates had accumulated additional mutation in ParE. Five isolates harboring the OXA-30. Enzyme showed intermediate resistant to eefepime. Conclusions Fluoroquinolone-resistant Salmonella typhimurium isolates were widely distributed among the outpatients in Wuhan and the resistant isolates accumulated multiple antimicrobial resistant mechanisms and showed unique genetic profiles. The state and local health authority must remain vigilant for the emergence of Salmonella typhimurium resistant to both third generation cephalosporins and fluoroquinolonos.

Objective To study on chromosome-and plasmid-mediated fluoroquinolones-resistant in Escherichia coli isolated from fecal samples of chicken,swine and people around the farm.Methods Anti-microbial susceptibility testing was carried out by disk diffusion testing and bmth microdilution testing.gyrA,gyrB,parC,pareE,qnr and aac(6')-I b-cr were examined by PCR,and the products were sequenced.Ex-presion of aac(6')-I b-cr by conjunction was tested too.Results The resistance to antimicmbial agents was much higher in strains isolated from chicken than that from swine and human.Among the E coli strains examined by PCR,most resistant strains carried two mutations in gyrA and/or two mutations in parC.In ad-dition,some resistant strains had mutations in parE with MIC of ciprofloxacin>16μg/ml.No(resistance) mutation was found in gyrB.Seven strains(25.O%)and one strain(11.1%)had aac(6)-I b-cr,variant isolated from chicken and swine,respectively.The strains harboring cr variant enzyme reduced the suscepti-bility to ciprofloxacin and norfloxacin by N-acetylation of the drugs. Conclusion There is a close relation-ship between high level quinolone resistance and the numbers of amino acid exchange in DNA gyrase and to-poisomeraae IV,and aac(6)-I b-cr may play some role for fluoroquinolone resistance.