Abstract: Objective To investigate the prevalence and pathogenic characteristics of Yersinia enterocolitica infection in children with diarrhea under 5 years of age in western Yunnan, and to provide a basis for the prevention and treatment of infectious diarrhea in children. Methods Feces were collected from under five-year-old children with diarrhea in the First Affiliated Hospital of Dali University from 2020 to 2021. Clinical information of the cases was also collected. Yersinia enterocolitica was isolated from the samples after cold enrichment on selective culture plates, and the pathogenic characteristics of Yersinia enterocolitica were analyzed by biological type and serotype and virulence gene detection. Results A total of 397 feces were collected. Seven strains of Yersinia enterocolitica were isolated in three samples, and the prevalence of Yersinia enterocolitica infection was 0.76% (3/397). Among the three positive samples, two Yersinia frederiksenii or Yersinia intermedia were isolated in specimen No. 212 , and five Yersinia enterocolitica were detected in specimens No. 24 and 226. Two Yersinia enterocolitica isolated from one sample were biological type 1A, and the virulence gene test results were ail-/ystA-/ ystB+ /yadA-/virF-, which were non-pathogenic Yersinia enterocolitica. Three Yersinia enterocolitica isolated from the other sample were biological type 3, serotype O∶3 (rfbc+), and virulence gene detection results were ail+/ystA+/ystB-/yadA+ /virF+, which were pathogenic Yersinia enterocolitica. While pathogenic Yersinia enterocolitica was detected from feces of children with diarrhea at 11 months of age with a infection rate of 0.50%(2/397). Conclusion Sporadic infection of pathogenic Yersinia enterocolitica was found in under five-year-old children in western Yunnan Province. It is necessary to strengthen the monitoring and research of Yersinia enterocolitica.

Objective To establish an extensively drug-resistant Acinetobacter baumannii (XDR-AB) infection model using Caenorhabditis elegans (C.elegans),and evaluate the effect of efflux pump inhibitors(EPIs) on reversal of ciprofloxacin resistance in XDR-AB.Methods XDR-AB infection model of C.elegans was established,six EPIs(CCCP,PAβN,NMP,omeprazole,reserpine,and verapamil)combined with ciprofloxacin were used to treat the infected model,the survival rate of C.elegans was recorded to evaluate the in vivo activities of drugs,toxicity test and in vitro drug susceptibility test were also performed.Results Lethal effect of different concentrations of XDR-AB on C.elegans was varied,5 × 106 CFU/mL of XDR-AB was selected to infect C.elegans.C.elegans survival test showed that survival curves of C.elegans infected with XDR-AB for 3 hours and curves of control group (polymixin B was added) were not significantly different (x2 =3.154,P＞0.05);compared with control group,survival curves of C.elegans infected with XDR-AB for 6 hours or 9 hours were significantly different (both P＜0.001),but 6 hours and 9 hours were not significantly different(x2 =0.669,P＞0.05),6 hours was chosen as the duration of infection,36 hours was appropriate for the duration of antimicrobial therapy.Ciprofloxacin with EPIs for infection model revealed that low concentration of PAβN,NMP,omeprazole,and reserpine could improve the survival rate of C.elegans by 30％-40％,15％-20％,20％-30％,and 20％ respectively,high concentration of verapamil could improve the survival rate of infected C.elegans by about 30％.In vitro susceptibility test and toxicity test results showed that ciprofloxacin combined respectively with CCCP,omeprazole,and verapamil could reduce minimum inhibitory concentration(MIC) to the original 1/4,combined respectively with PAβN,NMP,and reserpine could reduce MIC to the original 1/2,CCCP had the best bacterial inhibitory effect in vitro,but the toxicity was large,and was not suitable for the study of pharmacodynamics in vivo.Conelusion The infection model of C.elegans XDR-AB is initially and successfully established,which is used to evaluate the efficiency of six EPIs for reversing ciprofloxacin resistance.

Objective: To summarize the mid-term effect of modified extended Morrow procedure in patients with hypertrophic obstructive cardiomyopathy (HOCM) combining sub aortic valve obstruction and mid left ventricular obstruction. Methods: We studied 34 consecutive HOCM patients with sub aortic and midventricular obstruction who received modiifed extended Morrow procedure with extracorporeal circulation in our hospital from 1996-11 to 2015-01. Transthoracic echocardiography was conducted at pre-, post-operation and follow-up period to evaluate the changes of mid-ventricular gradient, subarctic gradient and each heart valve function. Results: The average follow-up time was (25.7 ± 14.9) months, 2 patients lost contact and no death occurred. In rest 32 patients, the mid ventricular gradient decreased from (60.3 ± 29.4) mmHg to (21.0 ± 19.8) mmHg, subaortic valve gradient decreased from (77.9 ± 26.2) mmHg to (11.6 ± 6.5) mmHg, the maximum ventricular septal thickness dropped from (25.2 ± 4.9) mm to (17.9 ± 7.2) mm, left atrial diameter reduced from (41.1 ± 7.8) mm to (37.6 ± 6.4) mm, left ventricular end-diastolic diameter increased from (39.8 ± 5.1) mm to (42.2 ± 4.3) mm, allP<0.05; there were 5 patients without obviously improved mid ventricular gradient because of insufifcient resection of septal myocardium in mid-ventricle. The post-operative NYHA classiifcation was improved,P<0.01, mitral valve regurgitation degree was decreased,P<0.01 and SAM phenomenon was disappeared. Complications included 3 (8.8%) patients of III atrio-ventricular block, 1 (2.9%) patient of re-admission due to poorly healed sternum combining pneumonia Conclusion: Modified extended Morrow procedure may relieve sub aortic valve and mid ventricular obstruction, therefore improve left ventricular diastolic function and prognosis in relevant patients.

Objective: In this study, we analyze the regulation mechanisms of the expression of ampD in AmpC β-lactamase and the regulation mechanism of β-N-acetylglucosaminidase (NagZ) in Yersinia enterocolitica. Methods: We construct the mutation strains of Yersinia enterocolitica AmpD (AmpD1-3) gene (ampD1-3), Low-Molecular-Mass Penicillin-Binding Proteins (LMM PBPs) gene (pbp4, pbp5a, pbp5b, pbp7), NagZ gene (nagZ), and ampR gene by deleting and complementing genes, and induce them by cefoxitin. We determined the activity of AmpC β-lactamase activity (U) of mutant strains (basal level and induce level) by using cephalothiophene hydrolysis method, the promoter activity of AmpC β-lactamase ((relative light unit (RLU)) was detected by the luxCDABEreporter system, and the activity of β-N-acetylglucosaminidase (nmol/L) was determined by by using 4-nitrophenyl N-acetyl-β-D-glucosaminide as the chromogenic substrate. Results: AmpD1 (Basal level: (3.29±1.58) U; Induced level: (4.08±1.75) U) was the most potent one. The YEΔ5b, YEΔ4Δ5b, YEΔ5aΔ5b and YEΔ5bΔ7 of ampC promoter activity increase significantly, whichYEΔ4Δ5b is the highest one (Basal level: (106 903.16±61 910.61) RLU; Induced level: (205 427.45±45 352.17) RLU). The YEΔ4Δ5bΔ7 of ampC promoter activity is the highest among triple mutant strain (Basal level: (304 108.04±99 274.53) RLU; Induced level: (531 440.21±68 891.02) RLU). Quadruple deletion strain YEΔ4Δ5aΔ5bΔ7 have the highest ampC promoter activity (Basal level: (1 013 810.99±260 955.96) RLU; Induced level: (1 230 214.59±205 526.79) RLU). After the deletion of nagZ gene, there is no significant change in β-lactamase activity of YEΔD1D2D3ΔZ, while β-lactamase activity of YEΔ4Δ5aΔ5bΔ7ΔZ shows a significant decrease (Basal level: (0.30±0.20) U; Induced level: (0.29±0.21) U), which basically drops to the wild strain level. Conclusion This is the first report of ampC multi-step upregulation mechanism driven by three AmpD homologues in Yersinia enterocolitica. The AmpC regulation mode with the function of single PBP4, PBP5a or PBP7 is relatively low, which work in coordination with PBP5b. Yersinia enterocolitica have both NagZ-depend and NagZ-independent mechanisms for β-lactamase expression.

Objective To indentify the risk factors of hemorrhage of cerebral arteriovenous malformations (AVMs) in children,and further conclude the treatment strategies and safety of these patients by endovascular embolization.Methods The clinical data of 56 patients with AVMs aged 3-14 years,admitted to our hospital from June 2005 to June 2015,were retrospectively analyzed.The risk factors of hemorrhage of these patients were identified by univariate and multivariate analyses;and the treatment strategies by endovascular embolization were analyzed.Results Univariate analysis indicated that small size of malformation vascular mass was the independent risk factor of hemorrhage for patients with AVMs in children (OR=0.292,95％CI:0.106-0.805,P=0.017).For 56 patients treated by endovascular embolization,a total of 121 feeding pedicles were embolized,and the mean obliteration rate of AVMs was 79％ (20％-100％).Finally,only 9 patients (7.9％) suffered embolization-related complications,such as headache,facial paralysical,hemianopsia,and activity obstacle;however,no patients suffered severe disability or death.After a follow-up of 2 months to 36 months (mean=17 months),all childem had favorable outcome,and none suffered intracerebral hemorrhage or recurrent AVMs.Conclusions Small size of malformation vascular mass is the independent risk factor of hemorrhage of patients with AVMs in children.The endovascular embolization of patients with intracranial AVM in children is efficacy and safe with few complications.

Objective:To investigate the distribution and molecular characteristics of Yersinia isolated from diarrhea patients in Jiangsu Province. Methods:From 2017 to 2021, the stool samples of diarrhea patients were collected in Tongshan District of Xuzhou City and Dongtai City of Yancheng City, Jiangsu Province, where the national active monitoring sites of Yersinia enterocolitica, then Yersinia was isolated; meanwhile, suspected Yersinia strains were collected from sentinel hospitals in the province. The DNA of isolated strains was extracted for whole genome resequencing, and the data were uploaded to the EnteroBase database for Yersinia species identification; the original data were cleaned and processed for 16S ribosomal RNA (16S rRNA) gene polymorphism analysis. Five virulence genes (ail, ystA, ystB, yadA, virF) were scanned through the National Center for Biotechnology Information (NCBI) and Pathogen Virulence Factor Database (VFDB), and K-mer Tree was constructed and genomic characteristics were analyzed. Results:From 2017 to 2021, a total of 2 058 stool samples from diarrhea patients were collected, and 57 strains of Yersinia were isolated and identified; meanwhile, two Yersinia strains were collected from the sentinel hospital. Compared with EnteroBase database, 51 strains were identified as Yersinia enterocolitica, 4 strains as Yersinia proxima, 1 strain each as Yersinia aleksiciae, Yersinia massiliensis, Yersinia intermedia and Yersinia canariae. The 16S rRNA gene polymorphism analysis showed that all strains were clustered into 3 groups, which could distinguish Yersinia enterocolitica from other Yersinia. Among the 51 strains of Yersinia enterocolitica, 49 strains were virulence genotype Ⅲ(ail-, ystA-, ystB+, yadA-, virF-), two strains were virulence genotype Ⅱ(ail+, ystA+, ystB-, yadA-, virF-); and 8 other Yersinia strains were virulence genotype Ⅳ (ail-, ystA-, ystB-, yadA-, virF-). K-mer analysis could distinguish Yersinia enterocolitica from other Yersinia, JS-XZ-2020001 strain was far away from other Yersinia enterocolitica isolates, and serotype O8 strains were more concentrated. Conclusions:The clinical isolates of Yersinia enterocolitica from diarrhea patients are mainly Yersinia and other Yersinia co-exist in a small amount in Jiangsu Province, two new Yersinia species ( Yersinia proxima and Yersinia canariae) are discovered. The virulence genotype of Yersinia enterocolitica is mainly type Ⅲ. The 16S rRNA gene polymorphism analysis and K-mer analysis can effectively distinguish Yersinia enterocolitica from other Yersinia.

Objective To explore the effect of Willis circle variation and hemodynamic forces alteration arised from vascular structural abnormity on intracranial aneurysm (IA) rupture using 3D-digital subtraction angiography (DSA) and transcranial color Doppler (TCCD) detection.Methods Two hundred and twenty-three patients with IA,admitted to and conformed by DSA in our hospital from November 2010 to November 2011,were divided into ruptured IA group (n=182) and un-ruptured IA group (n=41).The 3D-DSA was applied in all patients to carefully evaluate the aneurysm sizes,locations,and morphous features,and to confirm the presence of A1 dominance and Willis circle variation.Moreover,aneurysmal neck area,diameter of parent artery,angle between A2 segments of bilateral anterior cerebral artery,angle between aneurysmal longitudinal axis and parent artery,aortic diameter (AD) and aspect ratio (AR) were measured with assistance of 3D-DSA images.Besides,TCCD was applied to all patients,and the hemodynamic parameters were recorded to calculate wall shear stress (WSS) and mechanical stretch.The risk factors of IA rupture were analyzed by receiver operating characteristic (ROC) curve and multivariate Logistic regression with emphasis on Willis circle variation and hemodynamic forces alteration.Results Whether it was in ruptured IA group or in un-ruptured IA group,the incidence rate of variation of anterior Willis circle was higher than that of variation of posterior Willis circle.A1 dominance on the left side was the most common asymmetry.As compared with those in un-ruptured IA group,statistically elder age,smaller AD,larger angle between aneurysmal longitudinal axis and parent artery,decreased WSS and increased mechanical stretch in the ruptured IA group were noted (P＜0.05).ROC curve indicated that angle between aneurysmal longitudinal axis and parent artery,AD,WSS and mechanical stretch could be used to evaluate IA rupture (area under the curve:0.606、0.618、0.396、0.637).Age (OR=8.618,95％CI:2.866-25.917,P=0.000),hypertension (grade Ⅲ OR=16.320,95％CI:1.628-163.556,P=0.018),angle between aneurysmal longitudinal axis and parent artery (OR=3.053,95％CI:1.131-8.242,P=0.028),AD (OR=5.638,95％CI:1.507-20.251,P=0.008) and mechanical stretch (OR=4.230,95％CI:1.554-11.516,P=0.000) were risk factors of IA rupture.A1 dominance (OR=0.242,95％CI:0.074-0.785,P=0.018),small aneurysms (2-5 mm,OR=0.207,95％CI:0.054-0.788,P=0.002) and WSS (OR=0.021,95％CI:0.060-0.672,P=0.009) were identified as protective factors.Conclusions Willis circle variation exists in IA patients.Age,hypertension (grade ⅢD,angle between aneurysmal longitudinal axis and parent artery,AD and mechanical stretch are risk factors of IA rupture,while A1 dominance,small aneurysm (2-5 mm) and WSS are identified as protective factors.Accurate assessment of these factors is of great clinical significance for the prevention and treatment of IA in the future.

OBJECTIVE: To investigate whether collagen peptides can improve the immune functions of mice under the condition of simulated weightlessness. METHODS: Mouse tail-suspension model was used to simulate the effects of weightlessness. Tail-suspended mice were intraperitoneally injected with 600 mg collagen peptides per kilogram body weight once a day for 10 days. Then, the mice were killed, and white blood cells were counted and classified. Lymphocyte subsets and T lymphocyte proliferations in spleens were analyzed. RESULTS: Compared with normal control group, total and differential count of leukocytes, lymphocytes, T cells，CD4 and CD8 T cells, B cells and NK cells, and splenic T lymphocyte proliferation all decreased in the weightlessness simulated mice (P＜0.05). Except for NK cells, the above-mentioned parameters were increased after administration of collagen peptides, and some of the parameters were recovered to the levels of normal control mice (P＜0.05). CONCLUSION Collagen peptides can effectively improve peripheral blood lymphocyte distributions and T lymphocyte proliferations of mice under the condition of simulated weightlessness. This study nay provid the experimental basis for improvement of immune functions of astronauts.
Animals ; CD8-Positive T-Lymphocytes ; Cell Proliferation ; Collagen ; Lymphocyte Count ; Mice ; Peptides ; Spleen ; Weightlessness ; Weightlessness Simulation

Critical ultrasonography(CUS) is different from the traditional diagnostic ultrasound,the examiner and interpreter of the image are critical care medicine physicians.The core content of CUS is to evaluate the pathophysiological changes of organs and systems and etiology changes.With the idea of critical care medicine as the soul,it can integrate the above information and clinical information,bedside real-time diagnosis and titration treatment,and evaluate the therapeutic effect so as to improve the outcome.CUS is a traditional technique which is applied as a new application method.The consensus of experts on critical ultrasonography in China released in 2016 put forward consensus suggestions on the concept,implementation and application of CUS.It should be further emphasized that the accurate and objective assessment and implementation of CUS requires the standardization of ultrasound image acquisition and the need to establish a CUS procedure.At the same time,the standardized training for CUS accepted by critical care medicine physicians requires the application of technical specifications,and the establishment of technical specifications is the basis for the quality control and continuous improvement of CUS.Chinese Critical Ultrasound Study Group and Critical Hemodynamic Therapy Collabration Group,based on the rich experience of clinical practice in critical care and research,combined with the essence of CUS,to learn the traditional ultrasonic essence,established the clinical application technical specifications of CUS,including in five parts:basic view and relevant indicators to obtain in CUS;basic norms for viscera organ assessment and special assessment;standardized processes and systematic inspection programs;examples of CUS applications;CUS training and the application of qualification certification.The establishment of applied technology standard is helpful for standardized training and clinical correct implementation.It is helpful for clinical evaluation and correct guidance treatment,and is also helpful for quality control and continuous improvement of CUS application.

Objective: To illuminate the epidemic characteristics of Yersiniosis among children in the central city of Beijing and the accuracy of current clinical diagnosis towards Yersiniosis. Methods: Etiological surveillance of diarrheal patients, a total of 3 493 cases, was performed in a children hospital in central area of Beijing from 2011 to 2018 continuously. Collected the epidemiological and clinical information of the cases, analyzed the clinical and etiological diagnosis for Yersiniosis and bacterial dysentery and compared the distribution of Yersiniosis cases with the different symptoms. Results: A total of 3 493 acute diarrhea cases distributed from the age of 6 months to 13 years old, M (P₂₅, P₇₅) was 1.50 (0.75, 3.17) years old. The 28 cases were isolated Yersinia enterocolitica (isolation rate of 0.80%) and they could be diagnosed as Yersiniosis by etiology. The isolation peaked in May and February. A total of 85.71% (24/28) of Yersiniosis cases were under 5-year old. The children of 3-4 age group had the highest isolation rate (1.52%) while the rate (0.18%) of 0-1 age group was the lowest (P=0.025). The Yersinia enteroclitica isolation rates of diarrheal patients with the symptoms including mucus feces, fever, white blood cell (WBC) and red blood cell (RBC) in feces were higher than the patients without these symptoms (P>0.05). The 9 of 28 Yersiniosis cases by etiology diagnosis were clinical diagnosed as bacillary dysentery. Conclusion The infants and young children under 5-year old were the main population of Yersiniosis adolescent patients under 14-year old. The typical symptoms characterized with mucus stool, fever, WBC and RBC by routine microscopic examination. The preliminary clinical diagnosis of Yersiniosis is easily confused with bacterial dysentery.