Salmonella enterica serovar Choleraesuis strain C500 is a live attenuated vaccine that has been widely used in Chi‐na for over 50 years to prevent piglet paratyphoid .However ,as C500 is obtained by chemical methods ,the genetic background of this strain remained unclear .In this study ,we compared the genomic differences between the virulent reference strain C 78‐2 and C500 by suppression subtractive hybridization combined with the mirror orientation selection method (MOS‐SSH ) .Six genes (asr ,ydgF ,ydgD ,ydgE ,rpoS ,and ptsG) were lost in C500 strain .Using real‐time PCR analysis ,we demonstrated that the genes regulated by rpoS ,a vital transcriptional regulator playing an important role in Salmonella infection ,were downregulated in C500 .Additionally ,the virulence of the rpoS mutant strain C78‐2ΔrpoS was 100 000 times lower than the parental strain in BALB/c mice .So loss of rpoS gene is the major factor leading to the attenuation of C500 strain .

Objective To summarise the perioperative features of orthotopic liver transplantations(OLTs) in miniature porcine,to establish mature、stable OLT models.Methods In order to observe hemodynamics and blood changes and improved perioperative management and summarise the perioperative characteristics,8 preliminary experiments(group A) and 18 experiments(group B) of OLTs were performed without veno-venous bypass(VVB) in Chinese inbred miniature porcine.Results The mean operation time was(179.6?14.3)min in our 18 OLTs,and the mean anhepatic phase time was(27.3?3.4)min.Dramatic hemodynamic and metabolic changes were identified during anhepatic phase.The oneweek survival rate was 88.9% in group B,but all the 8 pigs in group A died.The experiment group pigs urinated after 3～5hours and had normal diet after 3days.Conclusions Decreasing the operation time and stability of hemodynamics in anhepatic phase are the keys for success in OLTs without VVB.

Objective:To evaluate the effect of urban-rural integrated medical insurance on rural households'catastrophic health expenditure(CHE),thereby proposing targeted optimization strategies for the integration.Methods:Based on the five tracking data of the China Household Tracking Survey(CFPS)from 2010 to 2018,Process Specification Model-Dynamic Integrity Dimension(PSM-DID)was used to empirically test the impact of urban-rural integrated medical insurance on rural households'catastrophic health expenditures.Results:The urban-rural integrated medical insurance system significantly reduces the incidence of CHE in ru-ral households.Mechanism testing indicates that health levels,human capital expenditures,and household asset accumulation are important channels of action.Conclusion:It is suggested to continuously promote the urban-rural integrated medical insurance sys-tem,formulate comprehensive policies for medical insurance according to local conditions,and incorporate catastrophic health indi-cators into the detection and warning indicator system for rural residents returning to poverty.

Objective:To analyze the clinical characteristics, examination results, treatment and prognosis of neonates with influenza virus infection in the neonatal intensive care unit (NICU).Methods:Clinical data of neonates with influenza virus infection who were hospitalized in the NICU of the General Hospital of Southern Theater Command of Chinese People′s Liberation Army from January 2018 to December 2020 were retrospectively analyzed.Results:A total of 11 hospitalized neonates with influenza virus infection in the NICU were recruited, including 2 cases of influenza A and 9 cases of influenza B. Ten cases (90.9%) had respiratory symptoms, and among them, there were 8 cases with increased oxygen demand, 7 cases with complicated pneumonia, 4 cases with dyspnea, and 2 cases with apnea.Seven cases showed abnormal body temperature, including 6 cases of fever, and 1 case of hypothermia.Five cases had circulatory system symptoms.Digestive system symptoms and urinary system symptoms were detected in 5 cases and 3 cases, respectively.Eight cases complicated with systemic symptoms, including 3 cases of poor mental response, 3 cases of worsening jaundice, 3 cases of weight loss, 2 cases of hyperglycemia, 1 case of edema and sclerosis.Ten cases were treated with gamma globulin immunotherapy, 2 cases were treated with plasma immune support, and 1 case was treated with Peramivir antiviral.Eight cases were treated with increased oxygen therapy, among which non-invasive ventilator parameters or modes increased in 4 cases, and nasal cannula oxygen concentration increased in 2 cases.The change of noninvasive-assisted ventilation to invasive-assisted ventilation occurred in 1 case, and 1 case developed the change of nasal cannula to noninvasive-assisted ventilation.Four neonates received anti-shock and (or) myocardial contractility therapy.Conclusions:Neonates with influenza virus infection in the NICU are mainly manifested as respiratory symptoms and fever, and the incidence of complicated pneumonia is high.Multiple systems may be involved at the same time, often leading to severe disease status.Comprehensive supportive treatment is necessary.Neonatologists should pay attention to these symptoms, and early detection of influenza virus and timely isolation are the key methods to prevent influenza outbreaks in NICU.

Objective:To explore the efficacy and safety of treating advanced esophageal cancer by implanting the common stent and the radioactive 125I particle stent with endoscope. Methods:The clinical data of patients with advanced esophageal cancer admitted to Jingbian County People's Hospital of Shaanxi Province, the First Affiliated Hospital of Xi'an Medical University, Xijing Hospital of Digestive Diseases of Air Force Medical University and the First Hospital of Yulin of Shaanxi Province from December 2014 to December 2020 were retrospectively analyzed. Patients were divided into common stent group ( n=66) and radioactive particle stent group ( n=34) according to different stent types. The postoperative complications, Karnofsky performance status (KPS) score, dysphagia score, restenosis rate and quality of life were compared between the two groups. Results:The incidences of postoperative retrosternal pain in the common stent group and the radioactive particle stent group were 65.2% (43/66) and 47.1% (16/34) respectively. The incidences of pharyngeal pain and hoarseness were 12.1% (8/66) and 5.9% (2/34) . The incidences of abdominal pain were 9.1% (6/66) and 2.9% (1/34) . The incidences of errhysis were 3.0% (2/66) and 2.9% (1/34) . The incidences of vomiting and nausea were 7.6% (5/66) and 5.9% (2/34) respectively. There were no statistically significant differences between the two groups ( χ2=3.04, P=0.081; χ2=0.40, P=0.527; χ2=0.53, P=0.467; χ2<0.01, P>0.999; χ2<0.01, P>0.999) . In the two groups, KPS scores in the first, second, third and sixth month after operation were higher than those before operation (all P<0.05) . KPS scores of the radioactive particle stent group in the second, third and sixth month were significantly higher than those of the common stent group [ (89.73±7.84) points vs. (82.37±7.42) points, t=4.62, P<0.001; (93.63±8.13) points vs. (88.33±7.28) points, t=3.74, P<0.001; (92.78±6.26) points vs. (87.28±8.73) points, t=3.77, P<0.001]. The dysphagia scores of patients in the two groups in the first, second, third and sixth month were lower than those before operation (all P<0.05) . The dysphagia scores of the radioactive particle stent group in the third and sixth month after operation were significantly lower than those of the common stent group [ (0.68±0.12) points vs. (2.33±0.32) points, t=26.20, P<0.001; (0.82±0.22) points vs. (2.67±0.24) points, t=36.92, P<0.001]. In the third month after operation, the restenosis rate of the radioactive particle stent group was significantly lower than that of the common stent group [5.88% (2/34) vs. 42.4% (28/66) , χ2 =14.27, P<0.001]. The scores of QLQ-C30 and OES-18 scales in the first, second, third and sixth month after operation were lower than those before operation (all P<0.05) . The scores of QLQ-30 scale in the radioactive particle stent group in the second, third and sixth month were significantly lower than those in the common stent group [ (19.12±3.02) points vs. (21.22±2.87) points, t=3.39, P=0.001; (15.04±1.68) points vs. (20.43±2.23) points, t=12.39, P<0.001; (14.38±2.18) points vs. (19.77±3.67) points, t=9.20, P<0.001]. The scores of OES-18 scale in the radioactive particle stent group were also significantly lower than those in the common stent group [ (17.13±2.07) points vs. (20.64±2.11) points, t=7.95, P<0.001; (15.22±1.88) points vs. (19.24±1.76) points, t=10.62, P<0.001; (14.74±2.36) points vs. (18.53±3.27) points, t=6.01, P<0.001]. Conclusion:The radioactive particle stent can improve the quality of life of patients with advanced esophageal cancer with esophageal stenosis, so as to improve dysphagia and reduce the restenosis rate after operation. However, whether it is obviously superior to common stent in prolonging survival time and reducing complications needs to be further confirmed by a multicenter, prospective, large-sample randomized controlled study.

To develop a clinical diagnosis technique for bluetongue virus infection, we established serotype-specific methods to detect serotype 4 of bluetongue virus (BTV-4). Two monoclonal antibodies (mAbs) against VP2 protein of BTV-4, named 4A-1G7 and 4B-1B6, were used as competitive antibodies in the competitive enzyme-linked immunosorbent assays (C-ELISA). We detected 50 negative serum samples from sheep, goats and cattle by C-ELISA. The cut-off values of 4A-1G7 and 4B-1B6 mAbs were 49% and 40%, respectively. The results of the sensitivity, specificity and repeatability by detecting standard positive serum, were consistent with the general standard of Office International Des Epizooties. Furthermore, serum samples of BTV-4, BTV-18 and BTV-20 infection could be screened out through the combined C-ELISAs by 4A-1G7 and 4B-1B6 mAbs. Thus, this technique may diagnose BTV-4, BTV-18 and BTV-20 infections.

To confirm the B cell epitope recognized by monoclonal antibody (MAb) 3G11 of bluetongue virus type 8 (BTV-8) VP2 protein prepared in our laboratory, antigen epitopes recognized by 3G11 were screened and identified by phage display technology. KLLAT sequence was found by sequencing of blue spot after four rounds panning and 283LL284 of common short peptide sequence was obtained after comparison to amino acid sequence of BTV-8 VP2 protein. The peptide sequences KLLAA, KALAT, KLAAT and KLLAT were synthesized and identified by indirect ELISA. KLLAA and KLLAT bound strongly with supernatant and as cites of 3G11 cells and reacted specifically with BTV-8 positive standard sera. Further sequence analysis showed that amino acid sequence 283LL284 was conserved among different serotypes of BTV-8 strains, and283LL284 was the key amino acids of antigen epitopes recognized by 3G11. This study laid the foundation to establish type 8 BTV specific immunological detection methods.

Objective    To investigate the characteristic volatile organic compounds (VOCs) in exhaled breath and their diagnostic value in patients with early stage lung cancer. Methods    Solid-phase micro-extraction combined with gas chromatography mass spectrometry was used to analyze exhaled breath VOCs of 117 patients with early stage lung cancer (54 males and 63 females, with an average age of 61.9±6.8 years) and 130 healthy subjects (79 males and 51 females, with an average age of 63.3±6.6 years. The characteristic VOCs of early stage lung cancer were identified, and a diagnostic model was established. Results    Ten characteristic VOCs of early stage lung cancer were identified, including acetic acid, n-butanol, dimethylsilanol, toluene, 2,3,4-trimethylheptane, 3,4-dimethylbenzoic acid, 5-methyl-3-hexene-2-ketone, n-hexanol, methyl 2-oxoglutarate and 4-methoxyphenol. Gender and the 10 characteristic VOCs were included in the diagnostic model, with a sensitivity of 83.8% and a specificity of 96.2%. Conclusion    Analysis of exhaled breath VOCs is expected to be one of the potential methods used for early stage lung cancer diagnosis.

Being a non-invasive diagnostic technique for molecular biological markers, exhaled breath detection has the most latent capacity and future in the diagnosis and treatment of tumors. The National Key Research and Development Plan named "Strategic Advanced Electronic Materials" in 2020 has laid out the application of exhaled breath detection technology in the medical field, and the scientific research project led by Sichuan Cancer Hospital has been successfully launched. For the moment, as a novel strategy for early detection of lung cancer, exhaled breath detection is being perfected further and popularized or put in clinical practice step by step to reduce the mortality of lung cancer patients.

Objective    To investigate the predictive value of volatile organic compounds (VOCs) on pulmonary nodules in people aged less than 50 years. Methods    The 147 patients with pulmonary nodules and aged less than 50 years who were treated in the Department of Thoracic Surgery of Sichuan Cancer Hospital from August 1, 2019 to January 15, 2020 were divided into a lung cancer group and a lung benign disease group. The lung cancer group included 36 males and 68 females, with the age of 27-49 (43.54±5.73) years. The benign lung disease group included 23 males and 20 females, with the age of 22-49 (42.49±6.83) years. Clinical data and exhaled breath samples were collected prospectively from the two groups. Exhaled breath VOCs were analyzed by gas chromatography mass spectrometry. Binary logistic regression analysis was used to select variables and establish a prediction model. The sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve of the prediction model were calculated. Results    There were statistically significant differences in sex (P=0.034), smoking history (P=0.047), cyclopentane (P=0.002), 3-methyl pentane (P=0.043) and ethylbenzene (P=0.009) between the two groups. The sensitivity, specificity and area under the ROC curve of the prediction model with gender, cyclopentane, 3-methyl pentane, ethylbenzene and N,N-dimethylformamide as variables were 80.8%, 60.5% and 0.781, respectively. Conclusion    The combination of VOCs and clinical characteristics has a certain predictive value for the benign and malignant pulmonary nodules in people aged less than 50 years.