A systematic analysis of the typeⅢ secretion genes of Aeromonas hydrophila strain AH-1 by constructing ahyR and ahyI mutant revealed that they are under quorum-sensing control. This observation was supported by the down-regulation of the TTSS genes in the presence of lacZ-TTSS gene promoter and the corresponding advanced secretion of AexT in ahyI mutant.

Virginiamycin acetyltransferase D (VatD) plays a vital rule in streptogramins resistance by chemically inactivating streptogramin A. Therefore, it is desirable to discover novel small molecular weight inhibitors of VatD via state-of-the-art virtual screening techniques. This "cocktail" strategy by combining VatD inhibitor with streptogramins may provide new therapeutic opportunity for resistant bacteria infections. Structure-based virtual screening method (molecular docking) was applied to rank and score a chemical database containing 300 000 commercially available compounds against the VatD substrate binding site. Twenty six out of the 200 top scored compounds from the docking calculation were selected and submitted to the VatD enzymatic inhibition assay. The plasmid pRSET B/vatD was constructed and transformed into E.coli (trxB) host cells for over-expression, and VatD enzyme was purified and validated by showing acetyltransferase activity to Virginiamycin M1. Three out of these 26 tested compounds showed enzymatic inhibition on VatD with IC50 168.6, 91.0 and 55.2 μmol·L-1, separately. Other compounds could not be dissolved in the system and/or had little effect on the enzyme (IC50>200 μmol·L-1). To our knowledge, it is first time that small molecular weight organic compounds were identified as VatD inhibitors. It is expected that the VatD inhibitors identified at present study could serve as lead compounds for the further development of the novel therapeutic agents to overcome streptogramins resistance.

Objective　To study the effects of estradiol-17β (17β-E2) on the synthesis of GnRH and GH in submandibular gland of rat. Method　Immunohistochemical ABC method was used to observe the localization of GnRH and GH in submandibular gland of rat.Results　　The synthsis of GnRH was promoted and the synthesis of GH was inhibited by 17β-E2 in rat's submandibular gland.　Conclusion　The 17β-E2 may play an important regulative role in the synthesis of GnRH and GH.

Objective To investigate the effect of optimized radiological examination strategy on iatrogenic radiation exposure in severe trauma patients so as to provide scientific basis for standardized application of radiological examination.Methods A controlled, three-stage intervention study from April 2010 to November 2011 was carried out.From April 2010 to July 2010, a pre-intervention study was conducted and enrolled 60 patients [43 males, 17 females;age (50 ± 14)years, age range 23-78 years].From August 2010 to March 2011, optimized strategies of radiological examination were implemented, including improving clinicians' knowledge to the standardization of radiological examination and iatrogenic radiation injury and limiting frequency of CT scans through the electronic medical record.From April 2011 to November 2011, post-intervention study was conducted and enrolled 100 patients (81 males, 19 females;age (47 ± 14) years, age range 18-79 years].During this period, major trauma patients were analyzed with respect to the clinical information, radiation examination frequency, ionizing radiation dose and influencing factors.Radiation examination frequency and radiation dose were compared before and after the intervention.Results Radiological examinations were mainly X-ray and CT before the implication of optimized strategies.Of the 60 patients, median frequency of X-rays and CT scan was 6.0(3.0-11.0) and 10.0(8.0-13.8).Median frequency of CT scan was positively correlated with the injury severity score (ISS) and ICU length of stay (r =0.369 and 0.523, P ＜ 0.05).Of the 100 patients, median frequency of CT scan was significantly reduced after the optimization of radiological examination (8.0 vs.10.0, P ＜ 0.05).Total frequency of radiological examination was significantly reduced as well (13.6 vs.17.8, P ＜0.01).There was no significant difference in the treatment success rate before and after the optimization of radiological examination (85.0％ vs.88.3％, P ＞ 0.05).When the frequency of head and chest CT scan was limited, the frequency of radiological examination, radiation exposure and radiological examination expenses were greatly reduced.Conclusions Too much X-ray,CT or other radiological examinations are noted in major trauma patients during the treatment period.Improved understanding of radiation-induced injury, optimizing radiological examination and controlling the repeated radiological examinations of the same site contribute to reducing iatrogenic radiology exposure without affecting the outcome.

Objective To estimate the clinical value of thinprep cytologic test (TCT) in screening cervical lesion. Methods 4234 TCT samples were interpreted according to the Besthesda System (TBS), 272positive cases (ASC-US or above) were taken colposcopic examination and biopsy. Results The coincidence of the results between TCT and biopsy in low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), squamous cell carcinoma (SCC), adenocarcinoma (AC) were 85.71%(12/14), 100 % (20/20), 75 % (3/4) and 100 % (2/2), respectively. The positive rates of over ASC-H by TCT and of over CIN Ⅰ by biopsy were 23.16 % (63/272) and 24.26 % (66/272), respectively. There is no difference between two positive rates (x2 = 0.868, P = 0.581). Conclusion TCT and histopathological diagnosis had a high coincidence, a combination of both can greatly enhance HSIL and cervical cancer and reduce the incidence of missed diagnosis. TCT would be a rapid and convenient method for screening cervical cancer.

Objective To summarize the diagnostic efficacy of ADC value for differentiation of benign and malignant lymph nodes on diffusion MRI with Meta-analysis. Methods Published papers on differentiation of benign and malignant lymph nodes with ADC value were searched and reviewed.Quality evaluation was performed for the eligible papers before data extraction.Test for heterogeneity was performed first,then appropriate model was selected to calculate the weighted mean difference,sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic odds ratio,pretest and posttest probability.The potential of ADC value for differentiation of benign and malignant lymph nodes was assessed qualitatively and quantitatively.Results Fifteen papers including 735 cases and 1963 lymph nodes were selected.According to Meta-regression analysis,subgroup analysis and robust analysis,two studies with benign lymph nodes in patients with benign lesion and one study using chemical shift saturation technique were excluded because of their impact on the robustness of the pooled results. The weighted mean difference (WMD) between malignant and benign lymph nodes was -0.355 × 10-3mm2/s[95％ confidence interval (CI):-0.423 ×10-3- -0.288 × 10-3 mm2/s].Although the cutoff of ADC value for differentiation in each study was different,the diagnostic efficacy was stable,the pooled sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic odds ratio and area under summarized receiver operator's curve were 0.87 (95％ CI:0.79-0.92),0.87 (95％ CI:0.82-0.90),6.5 (95％ CI:4.7-9.2),0.15 (95％ CI:0.09-0.25 ),43 ( 95％ CI:21-87 ),0.93 ( 95 ％ CI:0.90-0.95 ).The posttest malignancy probability of benign lymph node indicated by ADC was 6％,while that of malignant lymph node was 72％.Conclusion The ADC value can be used to differentiate benign and malignant lymph nodes with good sensitivity and specificity noninvasively.

Objective To investigate the effects of cleaning and disinfection of thermoplastic masks on the hospital infection in patients receiving precise radiotherapy for nasopharyngeal carcinoma ( NPC). Methods A prospective study was performed among 102 patients receiving precise radiotherapy for NPC from 2013 and 2016, consisting of 18 patients with early?stage ( I, Ⅱ) disease and 84 patients with advanced (Ⅲ, IV) disease. All patients were randomly divided into group A and group B using a random number table. For group A, the marker lines of thermoplastic masks were sandwiched by double plastic tapes;cleaning and disinfection plus ultraviolet ( UV ) disinfection were applied to the masks 1 h prior to radiotherapy and immediately after radiotherapy. For group B, only conventional UV disinfection was applied to the masks. The surface of the masks was examined and hospital infection during radiotherapy was evaluated. Results At the 18th radiotherapy, group A had a significantly lower mask surface colony count than group B (7.90±650 vs. 139.05±12929 CFU/cm2, P=0000). Group A also had a significantly lower incidence of hospital infection than group B (725% vs. 882%, P=0046). For the patients with early stage NPC, particularly, there was no significant difference in the incidence of infection between the two groups (556% vs. 667%, P=0629). For patients with advanced NPC, group A had a significantly lower incidence of infection than group B ( 762% vs. 929%, P=0035) . There were no significant differences in incidence rates of oral mucosal, skin, and respiratory system infections between the two groups ( 471% vs. 510%, P=0692;176% vs. 235%, P=0463;78% vs. 137%, P=0338) . In both groups A and B, the incidence of oral mucosal infection was significantly higher than the incidence rates of skin infection ( P=0001, 0000) and respiratory system infection ( P=0004, 0000) . Conclusions Thermoplastic mask is one of the risk factors for hospital infection in patients receiving precise radiotherapy for NPC. Timely cleaning and disinfection plus UV disinfection can significantly reduce the surface colony count and the incidence of hospital infection in patients with NPC, particularly in those with advanced NPC receiving precise radiotherapy. The incidence of hospital infection is the highest in the oral mucosa, followed by the skin and the respiratory system.

Surgical management of idiopathic macular hole (IMH) is a hot topic in the field of fundus disease,and its classical surgery is internal limiting membrane peeling.In recent years,many researchers explored inverted internal limiting membrane flap technique for IMH.However,how large the IMH is necessary for inverted internal limiting membrane flap technique? Does the inverted internal limiting membrane flap technique have more advantages in operating procedure,anatomical and functional recovery of IMH in comparison with internal limiting membrane peeling? Our clinical researches and relative literature showed that it is better to use inverted internal limiting membrane flap technique for ＞550 μm IMH.There is still no available evidence showed inverted internal limiting membrane flap technique is of more benefit to the anatomical repair and functional restoration in comparison with internal limiting membrane peeling for IMH.Some viewpoints in this field are open to question.

Objective:To investigate the clinical features, risk factors, treatment and prognosis of dermatomyositis (DM) patients with positive anti-melanoma differentiation associated gene 5(MDA5) antibody with rapidly progressive interstitial lung disease (RPILD).Methods:The clinical data of 88 DM patients from June 2019 to June 2020, at the rheumatology department of Guangdong Provincial People's Hospital were collected and retrospectively analyzed. T-test, non-parametric Mann-Whitney U test, Chi-squared test, Fisher exact probability and Logistics regression analysis were used for data analysis. Results:① 37%(36/88) DM patients were positive for anti-MDA5 antibody. The frequency of ulcerative rash, Gottron's sign, arthritis, clinically amyopathic dermatomyositis (CADM), and erythrocyte sedimentation rate (ESR) was significantly higher in patients with anti-MDA5 antibody ( P<0.05). The cell count of white blood cell, neutrophil, lymphocyte, and serum creatine kinase (CK) level were significantly lower in the anti-MDA5 antibody positive group than those in the negative group ( P<0.05). Of anti-MDA5 antibody positive DM patients, 100% developed ILD, 34% (11/32)developed RP-ILD, 16%(5/32) died, which were significantly higher than those of anti-MDA5 antibody negative patients ( P<0.05). ② Of anti-MDA5 antibody positive DM patients, the C reactive protein (CRP) level, positive rate of anti-Ro-52 antibody and mortality rate were significantly higher RPILD group than those in the non-RPILD group [15.70(4.49, 29.00) vs 3.22 (1.66, 7.15), Z=-2.440, P=0.014; 91% vs 43%, P=0.011; 46% vs 0, P=0.002]. Logistics regression analysis indicated that positive anti-Ro-52 antibody [ OR=4.561, 95% CI (1.797, 11.580), P=0.001] might be a risk factor for anti-MDA5 antibody positive DM-RPILD. ③ Among patients with anti-MDA5 antibody with RPILD, serum ferritin and D-dimer level was significantly higher and oxygenation index was significantly lower in the non-survival group than those in the survival group [1 931 (1 377, 7 379) vs 638(196, 876), Z=-2.556, P=0.009; 2 760(1 995, 4 854) vs 985(533, 1 588), Z=-2.379, P=0.017; 230(140, 256) vs 309(262, 382), Z=2.191, P=0.030]. In addition, the delayed intensive treatment time was significantly longer in the non-survival group than those in the survival group [(14.0±2.6) vs (4.5±1.4), t=7.899, P<0.01]. Furthermore, the proportion of combined therapy with two disease modifying antirheumatic drug (DMARDs) was significantly lower in the non-survival group than those in the survival group (0 vs 83%, P=0.015). Conclusion:Anti-MDA5 antibody may be associ-ated with characteristic clinical manifestations of DM, ILD, RPILD and high mortality rate. Positive anti-Ro-52 antibody may be a risk factor for anti-MDA5 antibody positive DM-RPILD. High serum ferritin and D-dimer level and low oxygenation index in RPILD patients may be associated with poor prognosis. Early treatment with two DMARDs may improve the prognosis of RPILD.

【Objective】To observe the effect of Moschus combined with Borneol on brain water content and blood-brain barrier(BBB)permeability in rat model of cerebral focal ischemia with reperfusion.【Methods】Thirty SD rats were randomized into 6 groups: sham-operation group,model group,Moschus(1 mg?kg-1?d-1)group,Borneol(3 mg?kg-1?d-1)group,Moschus with Borneol group,nimodipine(12 mg?kg-1?d-1)group.The rat model of cerebral focal ischemia with reperfusion was established with method of putting nylon monofilament in the internal carotid artery.The brain water content was evaluated by detecting the wet weight and dry weight of brain.The detection of cerebral extra-vascular Evans blue(EB)content was used to observe the changes of BBB permeability.【Results】After cerebral ischemia for 2 hours and reperfusion for 24 hours,water content and EB content in the model group increased significantly compared with the pseudo-operation group(P