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.

The temperature and salinity ranges for growth of twelve strains of marine Bdellovibrio-and-like organisms (BALOs) which affiliated with four different phylogenetic clusters in the family Bacteriovoracaceae and the lytic ability of them to six kinds of common shrimp pathogen vibrios were studied. The morphological characteristics of four representative strains were examined with transmission electron microscope. The results showed that the strains within the same cluster or sub-cluster had identical growth temperature or salinity. The growth temperature ranges of clusters IV, VI, IX and X strains were 20?C～35?C, 15?C～35?C, 15?C～40?C, 10?C～40?C, respectively, and the optimum growth temperature was about 30?C or 35?C. The growth salinity ranges of clusters IV, VI, IX and X strains were 5‰～40‰, 2.5‰～30‰, 5‰～60‰ and 5‰～60‰, and the optimum salinities were about 10‰, 5‰, 20‰ and 20‰, respectively. Three of the six kinds of vibrios tested were lysed by all the BALOs, while the others could only be lysed by some of the BALOs. However, differential lysis to some of the vibrios was also observed among BALOs within the same cluster. The four strains of different clusters all exhibited typical BALOs morphology, hav-ing vibrioid cell with a single polar flagellum.

ObjectiveTo investigate the effects of sevoflurane postconditioning on myocardial neutrophil infiltration in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Twenty-four ASA Ⅱ or Ⅲ patients (NYHA Ⅱ or Ⅲ ) of both sexes aged 20-50 yr with BMI of 19-25 kg/m2 undergoing cardiac valve replacement under CPB were randomly divided into 2 groups ( n =12 each):group control (group C) and group sevoflurane postconditioning (group S).Anesthesia was induced with midazolam,fentanyl,etomidate and rocuronium and maintained with iv infusion of fentanyl,midazolam and vecuronium.The patients were intubated and mechanically ventilated (VT 8-10 ml/kg,RR 10-14 bpm,I∶E 1∶2,FiO2 100％ ).PETCO2 was maintained at 35-40 mm Hg.In group S sevoflurane was inhaled immediately after aorta and vena cava were unclamped.The end-tidal sevoflurane concentration was maintained at 1.7％ for 5 min.Arterial blood samples were collected before surgery and at 1,2 and 4 h after aortic unclamping for determination of plasma cardiac troponin T concentration.Myocardial specimens were obtained from right auricular appendage after opening of pericardium and at 1 h after aortic unclamping for microscopic examination and determination of myocardial myeloperoxidase expression.ResultsSevoflurane postconditioning significantly decreased plasma cardiac troponin T concentration and myocardial myeloperoxidase expression and ameliorated histo-pathological damage in group S as compared with group C.ConclusionMyocardial neutrophil infiltration is involved in the protective effect of sevoflurane postconditioning against myocardial injury in patients undergoing cardiac valve replacement under CPB.

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Objective:To explore the relationship of serum interleukin (IL) -9 and platelet-activating factor (PAF) levels with serum total immunoglobulin E (IgE) levels, disease severity and disease course in patients with chronic spontaneous urticaria (CSU) .Methods:A total of 60 patients with active CSU were collected from Department of Dermatology, the First Affiliated Hospital of Hebei North University from March 2018 to March 2019 (active CSU group), and divided into mild group, moderate group and severe group according to 7-day urticaria activity score (UAS7). After 28-day standard antihistamine therapy, the patients whose condition became stable were included in the stable CSU group. During the same period, 30 health examinees were included in the healthy control group. Peripheral venous blood samples were collected from the subjects in each group, enzyme-linked immunosorbent assay (ELISA) was performed to detect serum levels of IL-9 and PAF, and immunoturbidimetric assay to detect the serum total IgE level. Correlations of serum IL-9 and PAF levels with serum total IgE levels, UAS7 scores and disease courses were analyzed in patients with CSU. One-way analysis of variance was used for comparisons among multiple groups, least significant difference- t test for multiple comparisons, and Pearson correlation analysis for correlation analysis. Results:Totally, 28 males and 32 females were included in the active CSU group, their age ranged from 11 to 68 years (34.68 ± 8.62 years), and the disease duration ranged from 2 months to 7 years (1.42 ± 0.41 years). In the healthy control group, 14 were males and 16 were females, and their age ranged from 10 to 70 years (35.06 ± 7.89 years). According to UAS7, 12, 26, and 22 patients were diagnosed with mild, moderate and severe CSU respectively, and 22 were included in the stable CSU group after standard treatment. The levels of serum IL-9, PAF and total IgE significantly differed among the active CSU group, stable CSU group and healthy control group (IL-9: 144.34 ± 23.19 vs. 109.25 ± 20.77 vs. 107.23 ± 19.23 pg/ml; PAF: 362.45 ± 51.45 vs. 223.18 ± 32.46 vs. 221.23 ± 28.38 pg/ml; total IgE: 168.12 ± 32.48 vs. 24.04 ± 7.04 vs. 21.76 ± 5.95 IU/ml; F = 38.80, 148.38, 499.12, respectively, all P < 0.001), and were significantly higher in the active CSU group than in the stable CSU group and healthy control group (all P < 0.05), while there was no significant difference between the stable CSU group and healthy control group (all P > 0.05). Pearson correlation analysis showed that the serum IL-9 and PAF levels were positively correlated with serum total IgE levels and UAS7 scores (all P < 0.05), but not correlated with the disease course (both P > 0.05) . Conclusion:Serum IL-9 and PAF levels in patients with active CSU were markedly elevated along with the increase in disease severity, and closely correlated with serum total IgE levels.

Objective:To investigate the epidemiological data of maternal sepsis in intensive care unit (ICU), analyze the common causes, outcomes of maternal sepsis, and the risk factors of multi-drug resistant (MDR) bacteria.Methods:A retrospective cohort study. Maternal sepsis cases admitted to ICUs of Peking University Third Hospital, Beijing Chao-Yang Hospital Affiliated to Capital Medical University, and Beijing Friendship Hospital Affiliated to Capital Medical University from January 2008 to September 2022 were enrolled. The following data were recorded: demographic characteristics, sequential organ failure assessment (SOFA) during infection, infection time, infection sites, invasive intervention measures before infection, microbial culture results, blood routine test during infection, body temperature, and clinical outcomes caused by infection. According to the time of sepsis occurrence, the patients were divided into pre-ICU sepsis group and ICU sepsis group, and the causes of sepsis in the two groups were analyzed. According to whether MDR occurred, the patients were divided into MDR group and non-MDR group, and clinical outcomes were analyzed. Multivariate Logistic regression was used to analyze the risk factors of MDR bacteria infection in obstetrics with sepsis.Results:160 patients were enrolled, among which 104 cases of sepsis happened before ICU and 56 cases of sepsis happened during ICU, 53 cases were with MDR bacteria and 107 cases were without MDR bacteria. The median age of the patients was 30.5 (28.0, 34.0) years old, the median temperature was 38.8 (38.2, 39.5) ℃, and the median white blood cell count (WBC) was 17.2 (13.2, 21.3)×10 9/L, the median SOFA score was 5.0 (3.0, 8.0), and 130 cases (81.2%) were referred from other hospitals. The main infection sites were uterine cavity in 64 cases (40.0%), lung in 48 cases (30.0%), abdominal and pelvic cavity in 30 cases (18.8%), urinary system in 27 cases (16.9%). Sepsis led to hysterectomy in 6 cases (3.8%), stillbirth in 8 cases (5.0%), and neonatal death in 2 cases (1.3%). The main surgical intervention measures were cesarean section (44 cases, accounting for 27.5%), followed by exploratory laparotomy (19 cases, 11.9%). The median length of ICU stay was 5.0 (3.0, 10.0) days, and the median hospital length was 14.0 (10.0, 20.8) days. Intrauterine infection was the primary cause of sepsis happened during ICU, accounting for 50.0% (28/56), of which postpartum hemorrhage accounted for 85.7% (24/28). The proportion of diabetes [28.3% (15/53) vs. 14.0% (15/107)], intrauterine operation [41.5% (22/53) vs. 23.4% (25/107)], intrauterine infection [50.9% (27/53) vs. 34.6% (37/107)] and bacteremia [18.9% (10/53) vs. 2.8% (3/107)] in the MDR group were significantly higher than those in the non-MDR group (all P < 0.05). Multivariate Logistic regression analysis showed that diabetes [odds ratio ( OR) = 2.348, 95% confidence interval (95% CI) was 1.006-5.480, P = 0.048] and intrauterine operation ( OR = 2.541, 95% CI was 1.137-5.678, P = 0.023) were independent risk factors for MDR bacterial infection in obstetrics with sepsis. Conclusions:Intrauterine infection is the common cause of maternal sepsis in ICU, and postpartum hemorrhage is the common cause of secondary intrauterine infection in ICU. MDR bacteria can lead to serious clinical outcomes. Diabetes and intrauterine operation are independent risk factors for MDR bacteria' infection.

Objective:To explore the correlation between serum levels of interleukin-9 (IL-9), platelet activating factor (PAF), total immunoglobulin E (IgE), interferon γ (IFN-γ), and interleukin-4 (IL-4) in patients with chronic spontaneous urticaria (CSU).Methods:Sixty CSU active phase patients admitted to the First Affiliated Hospital of Hebei North University from March 2018 to March 2019 were selected and included in the CSU active phase group. Based on the 7-day Urticaria Activity Score (UAS7), they were divided into three groups: 15 mild group, 25 moderate group, and 20 severe group; And 19 patients who entered the quiescent phase of the disease after 28 days of standardized antihistamine treatment were included in the CSU quiescent phase group. Another 30 healthy subjects who participated in the physical examination at the same time at our hospital′s physical examination center were selected to be included in the healthy control group. 5 ml of fasting elbow vein blood was collected from CSU active and stationary patients, as well as healthy subjects. The serum levels of IL-9, PAF, total IgE, IFN-γ, and IL-4 were detected using enzyme-linked immunosorbent assay. Pearson correlation test was used to analyze the correlation between serum IL-9, PAF levels and total IgE, IFN-γ, and IL-4 levels in CSU active patients.Results:The serum levels of IL-9, PAF, total IgE, and IL-4 in the CSU active phase group were higher than those in the CSU stationary phase group and healthy control group (all P<0.05), and the serum IFN-γ levels were lower than those in the CSU stationary phase group and healthy control group (all P<0.05). There was no statistically significant difference in the levels of the above indicators between the healthy control group and the CSU stationary group (all P>0.05). The serum levels of IL-9, PAF, total IgE, and IL-4 in the severe group were significantly higher than those in the mild and moderate groups (all P<0.05), and the serum IFN-γ levels were significantly lower than those in the mild and moderate groups (all P<0.05); The serum levels of IL-9, PAF, total IgE, and IL-4 in the moderate group were significantly higher than those in the mild group (all P<0.05), and the serum IFN-γ levels were significantly lower than those in the mild group ( P<0.05). Pearson correlation analysis showed that serum IL-9 and PAF levels were positively correlated with serum total IgE and IL-4 levels in CSU active phase patients (IL-9: r=0.726, 0.870, PAF: r=0.788, 0.795, all P<0.01), and negatively correlated with serum IFN-γ levels (IL-9: r=-0.831, PAF: r=-0.816, all P<0.01). Conclusions:The serum levels of IL-9 and PAF in patients with active CSU are elevated and correlated with total IgE, IFN-γ, and IL-4 levels, suggesting that IL-9 and PAF may be related to the occurrence and development of CSU.