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Objective To construct a Polyphosphate kinase 1 ( ppk1) gene deletion mutant of uro-pathogenic Escherichia coli (E.coli) CFT073, and to explore the biological properties of the mutant strain . Methods The ppk1 gene deletion strain (△pk1) was constructed based on CFT073 E.coli strain by usingλRed homologous recombination technology .A comparison analysis was conducted on adhesive and invasive abilities between CFT073 wild type strain and △pk1 strain in in vitro model of human bladder cancer epithe-lial cell 5637 .Crystal violet staining method was used to evaluate the influences of ppk1 gene deletion on biofilm formation.Results The CFT073 ppk1 deletion mutant strain was successfully constructed .Com-pared with the wild type strain ,△pk1 strain showed impaired adhesive and invasive abilities to 5637 cells. Moreover , the absorbance values of crystal violet at 570 nm at each time point of the mutant strain group were also lower than those of the wild-type strain group .Conclusion The ppk1 gene deletion mutant of uro-pathogenic E.coli CFT073 could be successfully constructed by Red homologous recombination technology and its biological properties indicates that ppk1 gene plays an important role in the pathogenesis of uropatho-genic E.coli infection through regulating the abilities of adhesion , invasion and biofilm formation .

Objective To explore the role of ppk1 gene in E.coli CFT073 strain during urinary tract infection (UTI). Methods C57BL/6 mouse models of acute UTI with the wild-type(CFT073) and ppk1 mutant (△pk1) infected, were used to compare the bacteria colonization and inflammation induction abilities of bladder tissues. Results In the mouse models, the △pk1 strain showed a significantly lower infection rate (73.3% vs 93.3%) and lower adhesion frequency of bladder (0.01%vs 0.5%) than those of the CFT073 strain. The expression of IL-6 and TNF-αwere reduced in the bladder of △pk1 infected group (P<0.05). Hematoxylin-Eosin tissue staining showed that the damage degree of bladders in △pk1 infected mice were less serious than the CFT073 infected mice. Conclusion ppk1 gene plays an important role in E.coli colonization to bladder and the inflammation induction ability.

OBJECTIVE To investigate the incidence of nosocomial infection in ICU patients,risk factors.and measures to prevent infection.METHODS The nosocomial infection of ICU patients in the hospitals from Nov 2005 to Jun 2009 was investigated using the method of target monitoring.The nosocomial infection rate was regulated by the method of ASA.The invasive procedure and the associated infection rate were analyzed.RESULTS Among 833 inpatients in ICU,92 suffered from nosocomial infection,The nosocomial infection rate was 11.04%.and the nosocomial infection rate per day was 4.43% after modified by the method of ASA.The incidence of patients was 5.37%.Totally 145 strains of bacteria were isolated,and the dominant pathogens were Gram-negative bacilli(56.55%).CONCLUSIONS The patients in ICU are susceptible population of nosocomial infection,A.baumannii is the dominating pathogen to cause nosocomial infection in intensive care units.Target monitoring in ICU is an effective surveillance method to reduce the prevalence of nosocomial infection.

OBJECTIVE To explore the disinfection methods for ophthalmology and to strengthen the measures of disinfection.METHODS The disinfection methods of the environment,equipment and operation field in ophthalmology were investigated and analyzed,and the good disinfection methods were summarized.RESULTS Due to strictly control the disinfection measures in ophthalmology,strengthen management,the hospital infection was reduced.In 2006 eye hospital infection rate was 0.CONCLUSIONS Good disinfection methods can effectively prevent eye hospital infection.

Objective To investigate the role and the mechanism of ppk1 gene (coding for polyphosphate kinase 1) in oxidative stress resistance in uropathogenic Escherichia coli (UPEC).MethodsMutant strains with ppk1-deletion (△pk1) and complemented strains (△pk1-C) were constructed based on the UPEC strain CFT073.A comparative analysis was conducted to analyze survival rates of CFT073, △pk1 and △pk1-C strains at different time points while they were under oxidative stress.Differences in protein expression between CFT073 and △pk1 strains were analyzed using mass spectrometric analysis.Differences between CFT073 and △pk1 strains in expression of katG and katE genes were analyzed using real-time quantitative RT-PCR.Results The survival rate of △pk1 strains was lower than that of CFT073 strains at every time point, while the survival rate of △pk1-C strains was basically the same as that of CFT073 strains.Gel image analysis and mass spectrometric analysis revealed that six proteins were down-regulated and one was up-regulated in △pk1 strains as compared with those in CFT073 strains.Expression of the catalase-coding genes katG and katE in △pk1 strains were respectively (20.5±8.2)% and (20.9±6.9)% of those in CFT073 strains (P<0.05).Conclusion The ppk1 gene plays an important role in oxidative stress resistance in UPEC by modulating the expression of catalase-coding genes katG and katE.

OBJECTIVETo investigate the loss of heterozygosity (LOH) on chromosomal arms 13q and 14q in nasopharyngeal carcinoma (NPC) using 21 microsatellite polymorphic markers and to study whether there is a correlation between LOH and clinicopathologic parameters and/or Epstein-Barr virus (EBV) infection in NPC.

METHODSSixty cases of NPC were studied using polymerase chain reaction based microsatellite analysis with genescan and genotyping techniques.

RESULTSLOH was detected on 13q in 78% of NPC tumors, high frequency LOH loci (more than 30%) clustered to 13q12.3-q14.3 and 13q32. On chromosome 14q, LOH was detected in 80% of NPC tumors; high frequency LOH loci clustered to 14q11-q13, 14q21-q24 and 14q32. High frequency LOH at 13q31-q32 correlated with a lower level of EBV infection; LOH on chromosome 14q was closely associated with poor differentiation of NPC tumor cells.

CONCLUSIONOur results suggest that in NPC, LOH on chromosome 13q and 14q are common genetic events, and putative tumor suppressor genes (TSG) residing in these regions may be involved in tumorigenesis.

Adult ; Aged ; Chromosomes, Human, Pair 13 ; genetics ; Chromosomes, Human, Pair 14 ; genetics ; DNA, Neoplasm ; genetics ; Female ; Gene Frequency ; Humans ; Loss of Heterozygosity ; Male ; Microsatellite Repeats ; Middle Aged ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Statistics as Topic

OBJECTIVETo evaluate the value of mediastinoscopy in diagnosing unknown mediastinal disease and staging of lung cancers.

METHODSFrom October 2000 to August 2001, 41 patients were examined by cervical mediastinoscopy with or without anterior mediastinotomy for diagnostic and staging purposes. Of these 41 patients, 12 were for diagnosis of unknown mediastinal disease, 3 for diagnosis and staging of pulmonary nodule or mass clinically suspected to be malignancy and 26 for the staging of lung cancer.

RESULTSTen of 12 patients with unknown mediastinal disease were diagnosed pathologically as thymoma in 1, metastatic lesion from lung cancer in 1, metastatic thyroid carcinoma in 1, lymph node hyperplasia in 1, teratoma in 1, sarcoidosis in 1, inflammatory pseudotumor in 1 and tuberculosis in 3, giving a diagnostic rate of 83.3%. Of three patients with suspected malignancy, one was diagnosed as tuberculosis by cervical mediastinoscopy and the other two as lymphoma and pulmonary inflammatory pseudotumor by thoracoscopy and thoracotomy. The sensitivity and specificity of mediastinoscopy for the staging of mediastinal nodes in 26 lung cancers were 87.5% and 100%. Only one wound infection but no other major complication was found.

CONCLUSIONMediastinoscopy is a safe procedure which can accurately provide information on diagnosis and staging.

Adult ; Aged ; Female ; Humans ; Lung Neoplasms ; diagnosis ; Male ; Mediastinal Neoplasms ; diagnosis ; Mediastinoscopy ; Middle Aged ; Neoplasm Staging

{L-End}Objective To investigate the current status of long working hours of food-delivery workers from food-delivery platform, and analyze its impact on their health such as occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and life satisfaction. {L-End}Methods A total of 2 145 food-delivery workers from two food-delivery platforms in Guangzhou City were selected as the research subjects using convenience sampling method. The occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and life satisfaction were investigated using the Core Occupational Stress Scale, Patient Health Questionnaire-9 items, Self-sleep Management Questionnaire, Self-diagnosis Questionnaire of Fatigue Accumulation of Workers, and World Health Organization Five-item Well Being Index. {L-End}Results The median and the 25th and 75th percentiles of weekly working hours were 63 (49,77) hours. And 92.2% (1 978/2 145) of workers, who worked more than 40 hours per week, were long working hours workers. While 70.1% (1 504/2 145) workers, who worked 55 hours or more per week, were ultra-long working hours workers. The detection rate of occupational stress, depressive symptoms, insomnia symptoms, fatigue accumulation, and low life satisfaction was 30.1%, 27.5%, 34.7%, 40.8%, and 75.1%, respectively. The longer the weekly working hours of the research subjects, the higher the detection rate of occupational stress and fatigue accumulation (all P<0.01). The results of multivariate logistic regression analysis showed that ultra-long working hours (weekly working hours ≥55 hours) was the influencing factor of occupational stress and fatigue accumulation after excluding the influence of confounding factors among workers (all P<0.05). {L-End}Conclusion The food-delivery workers of food-delivery platforms generally work long hours. Ultra-long working hours is a risk factor for occupational stress and fatigue accumulation among these workers.

There are many bidirectional communication and crosstalk between microbes and host plants. The plant-pathogen interaction directly affects the survival of host plants, while the interaction between plants and their probiotics benefits both. Plant miRNA responds quickly to pathogenic or beneficial microbes when they enter the plant tissues, while microbes also produce miRNA-like RNA (milRNA) to affect plant health. These means miRNA or milRNA is an important fast-responding molecular mediator in plant-microbe interactions, and these internal mechanisms have been better understood in recent years. This review summarized the regulatory roles of miRNA in plant-pathogens and plant-probiotics interaction. The regulatory role of miRNA in disease resistance of host plants during plant-pathogens interaction, and the regulatory role of miRNA in promoting host growth and development during plant-probiotics interaction, as well as the cross-kingdom regulatory role of milRNA in host plants, were discussed in-depth.
Disease Resistance ; MicroRNAs/genetics* ; Microbial Interactions ; Plants/genetics*