Objective To investigate the ability of linked color imaging(LCI)for diagnosing Helicobacter Pylori(Hp)infection compared with conventional white light imaging(WLI). Methods We prospectively collected subjects who underwent gastroscopy. Images under both WLI and LCI were recorded and analyzed. Software was used to measure pixel brightness for red(R),green(G),blue(B)of endoscopic images from suspected lesion sites. Biopsies were taken from these sites and Warthin-Starry silver staining was used to detect if Hp was present. R/(G+B)value was used to construct receiver operating characteristic curve(ROC)to predict Hp infec-tion and the area under curve(AUC),cut-off point,sensitivity,as well as specificity were calculated with the patho-logy as the gold standard. Results Forty-seven subjects(23 men,24 women;23 Uygur subjects,24 Han subjects) were included in a mean age of 49 years old. Ninety-one biopsies were obtained. Forty-four biopsies (48.4%)were Hp positive according to the pathology. The AUC of LCI was 0.616,with the cut-off point at 0.967 and sensitivity at 0.955 and specificity at 0.298. The AUC of WLI was 0.529,with cut-off point at 2.638 and sensi-tivity at 0.455 and specificity at 0.766. The AUC of Han and Uygur subjects were 0.650 and 0.549 by LCI. The AUC of atrophy gastritis subjects and non-atrophy gastritis subjects were 0.628 and 0.603. Conclusion LCI was superior to WLI in predicting Hp infection. LCI may act as an objective and quantified endoscopic diagnostic meth-od in Hp infection.

Objective To detect the positive rates of antibodies against avian influenza virus (AIV) subtypes H5, H6, H7 and H9 among people in poultry occupations in Guangdong province and to analyze the transmission of various subtypes of AIV from poultry to human contacts for the prevention and control of novel AIV infection in human beings.Methods Serum specimens were collected from 1066 peo-ple in poultry occupations ( occupational group) and 205 people not in poultry occupations ( non-occupational group) in 10 cities of Guangdong province.The inactivated AIV strains, isolated from poultry or environment of Guangdong province, were used as antigens to detect antibodies against AIV subtypes H5, H6, H7 and H9 by using the hemagglutination inhibition ( HI) assay.Results The positive rates of antibodies against AIV subtypes H5, H6, H7 and H9 carried by people from the occupational group were respectively 0.44%, 0%, 0.30%and 0.30%in 2013 and 1.08%, 0.0%, 0.0%and 0.27%in 2014.Only the anti-H9 anti-bodies were detected in serum samples collected form people in the non-occupational group in 2013 with a positive rate of 0.95%.No significant differences with the positive rates of anti-AIV antibodies were found between the occupational group and the non-occupational group.However, the geometric mean titer ( GMT) of anti-AVI antibodies in people from the occupational group was higher than that of the non-occupational group.Conclusion Although a grand spread of AIV from avian to human is not likely to happen yet, con-tacting with poultry is the risk factor for AIV infection in Guangdong population.A long-term surveillance of anti-AIV antibodies in serum should be strengthened among people in poultry occupations for the timely pre-vention and control of novel AIV outbreak.

Objective To understand the status of infection and epidemic trend of Dengue fever and Chikungunya in Guangdong.Methods Retrospective survey and literature review were used to obtain data on the incidence,etiology of Dengue and Chikungunya.Serological survey was conducted to detect the specific-antibodies in healthy individuals for both Dengue virus (DENV) and Chikungunya virus (CHIKV).Results Three epidemics of Dengue fever were observed during 1990-2012,with the annual incidence rates as 9.75/100 000 in 1995,1.76/100 000 in 2002 and 1.25/100 000 in 2006,respectively.The predominant epidemic strains appeared to be DENV-2 and DENV-4 during 1990-1994.Since 1995,DENV-1 had become the predominant transmission strain which lasted for almost 13 years.Co-existence of multiple serotypes of DENV started in 2009.Of the 7 718 sera from healthy population during 2003-2012,180 specimens were detected positive for specific DENV-IgG antibody,ended with a sero-prevalence rate of 2.33％.All 2 132 sera in 2012 were detected negative for CHIKV-IgG antibody.Conclusion The overall exposure level to Dengue was considered to be low in Guangdong province.However,the predominant transmission mode caused by DENV-1 had been gradually changed into the co-existence of multiple serotypes with the endemic signs appeared in some part of the areas.Chikungunya was a newly emerging disease in Guangdong since local people were lack of basic immunity barrier.Surveillance and control programs thus seemed important.

Objective This study aimed to evaluate the safety and efficacy of video-assisted thoracoscopic bipolar radio-frequency ablation in the treatment of isolated paroxysmal atrial fibrillation.Methods From September 2010 to December 2016,Seventy-two consecutive patients with paroxysmal atrial fibrillation underwent video-assisted thoracoscopic bipolar radio-frequency ablation at Fuwai Hospital.There were 50 males and 22 females with an average age of(56.5 ± 10.5) years and duration of atrial fibrillation with (6.5 ± 4.8) years.45 patients had previous catheter ablation.The patients were followed up at postoperative 3 months,6 months,1 year and annually.Success of ablation was defined as sinus rhythm and no duration of ≥30 s for rapid atrial arrhythmias,including atrial fibrillation,atrial flutter or atrial tachycardia in 24 h Holter examination.Univariate and multivariate logistic regression models were used to analyze the risk factors for atrial fibrillation recurrence.Results One patient converted to sternotomy due to bleeding on operation.All patients were successfully discharged.69 patients completed follow-up,with an average follow-up of(28 ± 18)months(3-60 months).The overall success rate was 73.9％,and the success rate without antiarrhythmic drug was 62.3％.Subgroup analysis showed that the success rate was 80％ when left atrial anterior and posterior diameter(LAD) ≤40 mm,and 57.9％ when LAD ＞ 40 mm (P =0.035).Multivariate logistic regression analysis showed that LAD ＞40 mm was an independent risk factor for postoperative recurrence of atrial fibrillation.Conclusion Video-assisted thoracoscopic bipolar radiofrequency ablation is a safe and effective method for the treatment of paroxysmal atrial fibrillation,especially in patients with LAD≤40 mm.

Objective:To explore the method of early prediction of the risk of limb infection in patients bitten by trimersurus mucrosquamatus snake. Methods:Totally 108 inpatients with limbs bitten by trimersurus mucrosquamatus snake in Chongqing Emergency Medical Center from January 2019 to October 2020 were respectively collected. They were divided into the infection group (23 cases) and non infection group (85 cases) according to whether they had secondary infection in the course of the disease. The clinical characteristics and serum indexes before admission were compared between the two groups to screen out the risk factors of infection. By combining all the above methods, the risk factor score was screened out; and the prediction model was constructed according to the snake bite severity score (SSS) and appearance score. The differences of the three prediction models between the two groups of patients were compared, and the predictive value of the three prediction models for the risk of limb infection in patients bitten by trimersurus mucrosquamatus snake was evaluated through the receiver operating characteristic (ROC) curve. Results:There were significant differences in clinical characteristics and serum indexes before admission, injury time, hand and foot finger injury, edema score, tension blister, subcutaneous hemorrhage and admission platelet count between the two groups ( P<0.05). The scores of the three predictive models differed between the two groups ( P<0.05). The ROC curve was used to evaluate the predictive value of the three models for the risk of infection in the course of the disease. The predictive AUC value of the risk factors score was 0.830 (95% CI: 0.635-0.850), the cutoff value was 2.5, the sensitivity was 0.870 and the specificity was 0.671, which was the best in the three prediction models. Conclusions:The prediction model based on the risk factors can effectively predict the infection risk of snake bite patients. It indicates that the infection risk is high when the score of risk factors ≥3 points, which can be used as the basis for guiding clinical treatment plan and is worthy of promotion.

Objective To provide scientific evidence to identify and confirm severe acute respiratory syndrome (SARS) by laboratory detection.Methods Multiple clinical specimens were collected serially and systematically from the 4 suspected SARS patients, which occurred between Dec.2003 to Jan.2004 in Guangdong Province. The samples were tested by serologic and molecular methods.Results IgM or IgG antibodies against SARS-CoV were detectable after 6—8 days of the onset in four patients. The four-fold or greater rising in antibodies was clearly detected in three of the four patients, while the fourth patient’s seroconversion was from negative to positive. The results analysed by enzyme-linked immunosorbent assay( ELISA), immunoflourescence assay (IFA), and neutralization test were highly correlated. SARS-CoV RNA was just detected in 3 throat swab specimens from case 1 by real-time PCR. M, N and S genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from the positive samples. Sequencing results showed that they were SARS-CoV gene segments, and most closely matched SARS-CoV gene sequences were isolated from civet cats in Guangdong Province. Nevertheless, SARS-CoV was not isolated from any samples of the 4 patients.Conclusion Based on these results, the 4 reported cases were laboratorily confirmed as SARS cases.

Objective:To analyze the epidemiological characteristics of the cases firstly reported as "asymptomatic infection of COVID-19" in Guangdong province.Methods:The follow-up observation method was used to continuously track and observe the cases firstly reported as "asymptomatic patients with COVID-19" in Guangdong province from January 14 to March 31, 2020. The epidemiological data of the cases were collected to analyze their epidemiological characteristics, outcome and influencing factors.Results:From January 14 to March 31, 2020, a total of 325 cases were firstly reported as "asymptomatic infections of COVID-19" in Guangdong province. The epidemic curve of asymptomatic infection cases was similar to that of confirmed cases, and it had two peaks. The first peak was from January 27 to February 5, and the second peak was from March 17 to March 26. Of the 325 cases, 184 (56.6%) were subsequently converted to confirmed cases. These cases were defined as incubation period asymptomatic infection cases. The age median of the cases was 40 years, and 93.5% (172/184) of the cases showed symptoms within 3 days after the first positive nucleic acid tests were conducted, and 141 (43.4%) of the 325 cases remained asymptomatic status until they were cured and discharged. They were inapparent infection cases, accounting for 8.6% (141/1 642) of those diagnosed with COVID-19 in Guangdong province during the same period. The age median of inapparent infection cases was 27 years. The median of the interval between the first positive nucleic acid test and discharge was 14 days. Up to 90.8% (138/141) of the inapparent infection cases were discharged for centralized medical observation within 28 days. The longest interval between the first positive nucleic acid test and the last positive nucleic acid test was 73 days. The positive rate of nucleic acid test was 0.3% in close contacts of inapparent infection cases and 2.2% in close contacts of incubation period asymptomatic infection cases. There were significant differences in age distribution and source of infection between incubation period asymptomatic infection cases and inapparent infection cases ( P<0.05). Old age was the risk factor for the conversion of firstly reported asymptomatic infection cases to confirmed cases. Compared with the 0-19-year-old group, The patients aged 40-59 years and 60 years and above were more likely to become confirmed cases. The OR (95 %CI) values were 2.730 (1.380-5.402) and 5.302 (2.199-12.783), and P values were 0.004 and 0.000, respectively. People being infected in China were more likely to become confirmed cases ( OR=7.121, P=0.000). Conclusions:There were asymptomatic infection cases among patients diagnosed with COVID-19. The infectiousness of incubation period asymptomatic infection cases might be stronger than that of inapparent infection cases. The proportion of younger cases among asymptomatic infection cases was higher than that of the confirmed cases. Old age and domestic infection were the risk factors for the conversion of asymptomatic infection cases to confirmed cases, to which more attention should be paid. Further serological investigations are needed to provide a basis for the development of COVID-19 prevention and control strategies.

Objective To evaluate the influence of diabetes on coronary artery bypass graft (CABG) surgery using bilateral internal mammary artery (BIMA). Methods From December 2015 to August 2017, 182 patients (153 males, 29 females, age of 56.5±6.8 years) underwent CABG using BIMA. The propensity score was used to create matched diabetes (n=66) and non-diabetes (n=66) cohorts. The operative data, post-operative outcomes and coronary computed tomographic angiography (CTA) of the diabetes group (53 males, 13 females, age of 57.8±7.2 years) and the non-diabetes group (56 males, 10 females, age of 56.3±6.0 years) were analyzed retrospectively. Results There was no peri-operative mortality. There was no difference in operative sternal wound complication (P=0.466), or graft patency (P=0.730 for internal mammary arteries and 0.684 for saphenous vein grafts) between the matched diabetes and the non-diabetes groups. However, patients with elevated glycated hemoglobin (HbA1c) (n=54) had more sternal wound complications (P=0.006). The level of Hb1Ac of the patients with sternal wound complication was significantly higher than that of the patients without sternal wound complication. Conclusion BIMA grafting may be performed routinely even in diabetic patients, without increased complications. However, elevated HbA1c level should be avoided to reduce sternal wound complication.

Objective     To evaluate the safety and efficacy of skeletonized and pedicled harvesting of bilateral internal mammary artery (BIMA) in coronary artery bypass graft (CABG) surgery. Methods     From December 2015 to May 2017, 152 patients (128 males, 24 females, age of 56.5±6.8 years) underwent CABG using either skeletonized BIMA (s-BIMA group, n=73) or pedicled BIMA(p-BIMA group, n=79). The operative data and post-operative outcomes were analyzed in the s-BIMA group (61 males, 12 females, age of 56.6±7.0 years) and the p-BIMA group (67 males, 12 females, age of 56.3±6.7 years). Results     There was no peri-operative mortality. There was no statistical difference in operative time, cardiopulmonary bypass time, aortic cross-clamp time or internal mammary artery graft flow between the two groups. One patient(1.4%) in the s-BIMA group suffered from severe sternal wound complication, which was major sternal wound complication. Five patients (6.3%) in the p-BIMA group suffered from sternal wound complications, including 1(1.3%) with severe complication and 4(5.1%) with minor complication. One(1.4%) patient in the s-BIMA group and 7 (8.9%) patients in the p-BIMA group suffered from chylothorax. The chest tube drainage significantly reduced in the s-BIMA group, both in postoperative day 1(P=0.000) and postoperative day 1-3 (P=0.001). CT angiography showed no stenosis of BIMA in both groups. Conclusion     The use of skeletonized BIMA for CABG is safe and efficacious, with less sternal wound complications, chylothorax and chest tube drainage. Skeletonization should be   suggested if BIMA is harvested in CABG.

Objective To verify whether hybrid surgical and interventional ablation(HA) for the treatment of persistent atrial fibrillation (AF) is superior to video-assisted thoracoscopic surgical radiofrequency ablation (VATS-RA). Methods From September 2010 to December 2017, 79 consecutive patients with persistent AF underwent VATS-RA or HA in Fuwai Hospital. VATS-RA was performed in sixty patients (a stand-alone surgical group, 48 males and 12 females, at average age of 56.0±7.6 years, and HA was performed in nineteen patients (a hybrid group, 14 males and 5 females, at average age of 58.0±7.3 years). Follow-up was completed at 3 months, 6 months, 1 year and annually thereafter. Postoperative sinus rhythm was defined as sinus rhythm recorded in 24-hour or 7-day Holter during follow-up, without exhibited rapid atrial tachyarrhythmia≥30 s including AF, atrial flutter, or atrial tachycardia. Results Seventy-eight patients (98.7%) completed the follow-up. Although the preoperative left atrial diameter (49.1±5.3 mm) in the hybrid group was significantly greater than that in the stand-alone surgical group (41.7±6.2 mm, P<0.001). Overall sinus rhythm maintenance rate in the hybrid group was significantly greater than that in the stand-alone surgical group (94.7% versus 64.4%, P=0.011). And sinus rhythm maintenance rate free from anti-arrhythmic drugs (AADs) and catheter ablation in the hybrid group was significantly greater than that in the stand-alone surgical group (84.2% versus 50.8%, P=0.010). Conclusion HA is superior to VATS-RA in the treatment of persistent AF, but a larger sample size is needed for further validation in prospective randomized studies.