Objective To understand the genetic structures and variations of the superintegron (SI) in Vibrio cholerae isolated in the seventh cholera pandemic.Methods Polymerase chain reaction scanning and fragment sequencing were used.Sixty toxigenic V.cholerae O1 EI Tor strains isolated between 1961 and 2008 were analyzed.Results Some variations were found,including insertions,replacements,and deletions.Most of the deletions were probably the result of recombination between V.cholerae repeat sequences.The majority of the variations clustered together.The Sls of the strains isolated in the 1960s and 1970s showed more diversity,whereas SI cassette variations in strains isolated in the 1990s and after were lower,with ～24 kb signature sequence deletion.This indicates the predominant Sl in the host during the epidemic in the 1990s and after.The insertion cassettes suggested the mobilization from the Sls of other Ⅴ.cholerae serogroups and Vibrio mimicus.Conclusion The study revealed that structural variations of Sls were obvious in the strains isolated in epidemics in different decades,whereas the divergence was based on syntenic structure of Sls in these El Tor strains.Also,the continuing cassette flows in the Sls of the host strains during the seventh cholera pandemics were displayed.
Objective To investigate in vitro cytotoxicity and oxidative stress response induced by multiwalled carbon nanotubes (MWCNTs).Methods Cultured macrophages (murine RAW264.7 cells) and alveolar epithelium cells type Ⅱ (human A549 lung cells) were exposed to the blank control,DNA salt control,and the MWCNTs suspensions at 2.5,10,25,and 100 μg/mL for 24 h.Each treatment was evaluated by cell viability,cytotoxicity and oxidative stress.Results Overall,both cell lines had similar patterns in response to the cytotoxicity and oxidative stress of MWCNTs.DNA salt treatment showed no change compared to the blank control.In both cell lines,significant changes at the doses of 25 and 100 μg/mL treatments were found in cell viabilities,cytotoxicity,and oxidative stress indexes.The reactive oxygen species (ROS) generation was also found to be significantly higher at the dose of 10 μg/mL treatment,whereas no change was seen in most of the indexes.The ROS generation in both cell lines went up in minutes,reached the climax within an hour and faded down after several hours.Conclusion Exposure to MWCNTs resulted in a dose-dependent cytotoxicity in cultured RAW264.7 cells and A549 cells,that was closely correlated to the increased oxidative stress.
Objective Lidamycin (LDM) can be dissociated to an apoprotein (LDP) and an active enediyne chromophore (AE).The detached AE can reassemble with its LDP-containing fusion protein to endow the latter with potent antitumor activity.However,the reassembly of AE with LDP is affected by several factors.Our aim was to optimize the assembly efficiency of the AE with a LDP-containing fusion protein and investigate the influence of several factors on the assembly efficacy.Methods A method based on RP-HPLC was developed to analyze the assembly rate,and an orthogonal experimental design L9 (34) was used to investigate the effects of temperature,assembly time,pH and molecular ratio of LDP-containing fusion protein to AE on the assembly rate.Furthermore,the determined optimum conditions for the assembly rate of the LDP-containing fusion protein with AE were applied and evaluated.Results A calibration curve based on the LDM micromolar concentration against the peak-area of AE by HPLC was obtained.The order in which individual factors in the orthogonal experiment affected the assembly rate were temperature＞time＞pH＞molar ratio of AE to protein and all were statistically significant (P＜0.01).The optimal assembly conditions were temperature at 10 ℃,time of 12 h,pH 7.0,and the molar ratio of AE:protein of 5:1.The assembly rate of AE with a LDP-containing fusion protein was improved by 23％ after condition optimization.Conclusion The assembly rate of chromophore of lidamycin with its LDP-containing fusion protein was improved after condition optimization by orthogonal design,and the optimal conditions described herein should prove useful for the development of this type of LDP-containing fusion protein.
Objective To create transgenic mice expressing hamster- and human-PRNP as a model for understanding the physiological function and pathology of prion protein (PrP),as well as the mechanism of cross-species transmission of transmissible spongiform encephalopathies (TSEs).Methods Hamster and human-PRNP transgenic mice were established by conventional methods.The copy number of integrated PRNP in various mouse lines was mapped by real-time PCR.PRNP mRNA and protein levels were determined by semi-quantitative RT-PCR,real-time RT-PCR,and western blot analysis.Histological analyses of transgenic mice were performed by hematoxylin and eosin (H & E) staining and immunohistochemical (IHC) methods.Results Integrated PRNP copy number in various mouse lines was 53 (Tg-haPrP1),18 (Tg-huPrP1),3 (Tg-huPrP2),and 16 (Tg-huPrP5),respectively.Exogenous PrPs were expressed at both the transcriptional and translational level.Histological assays did not detect any abnormalities in brain or other organs.Conclusion We have established one hamster-PRNP transgenic mouse line and three human-PRNP transgenic mouse lines.These four transgenic mouse lines provide ideal models for additional research.
Objective To evaluate dietary iodine intake and its potential risks among the Chinese population.Methods Individual dietary iodine intake was calculated using food consumption data multiplying by iodine concentration in foods,table salt and drinking water,followed by summing,and then compared with the corresponding age-specific reference values,including Upper Intake Level (UL) and Recommended Nutrient Intake (RNI).Results In areas with water iodine concentration (Wl) lower than 150 μg/L,80.8％ of residents had iodine intake between the RNI and UL,5.8％ higher than UL,and the remaining (13.4％) lower than RNI if iodized salt was consumed.However,in the uniodized salt consumption scenario,only 1.0％ of residents between RNI and UL,1.4％ higher than UL,and a large part of residents (97.6％) lower than RNI.In areas with Wl higher than 150 μtg/L,all residents had iodine intake between RNI and UL if iodized salt was consumed,except 10.5％ and 24.9％ of residents higher than UL in areas with Wl at 150-300 μg/L and higher than 300 μg/L respectively.However,in the uniodized salt consumption scenario,only 1.5％ and 1.7％ of residents had higher iodine intake than UL respectively.Conclusion The findings suggested that in general,the dietary iodine intake by the Chinese population was appropriate and safe at the present stage.People in areas with Wl lower than 150 μg/L were more likely to have iodine deficiency.While people in areas with Wl higher than 150 μg/L were more likely to have excessive iodine intake if iodized salt was consumed.
Objective To evaluate the effect of the aluminum hydroxide (AI-OH) adjuvant on the 2009 pandemic influenza A/H1N1 (pH1N1) vaccine.Methods In a multicenter,double-blind,randomized,placebo-controlled trial,participants received two doses of split-virion formulation containing 15 μg hemagglutinin antigen,with or without aluminum hydroxide (AI-OH).We classified the participants into six age categories (＞61 years,41-60 years,19-40 years,13-18 years,8-12 years,and 3-7 years) and obtained four blood samples from each participant on days O,21,35,and 42 following the first dose of immunization.We assessed vaccine immunogenicity by measuring the geometric mean titer (GMT) of hemagglutination inhibiting antibody.We used a two-level model to evaluate the fixed effect of aluminum AI-OH and other factors,accounting for repeated measures.Results The predictions of repeated measurement on GMTs of formulations with or without AI-OH,were 80.35 and 112.72,respectively.AI-OH significantly reduced immunogenicity after controlling for time post immunization,age-group and gender.Conclusion The AI-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.
Objective To explore correlation of seven apoptosis-related proteins (Hsp90α,p53,MDM2,Bcl-2,Bax,Cytochrome C,and Cleaved caspase3) with clinical outcomes of ALK+ anaplastic large-cell lymphoma (ALCL).Methods Using immunohistochemistry and immunofluorescence double staining methods,the expressions of these seven apoptosis-associated proteins were studied to clarify their relationship with clinical outcomes of 36 ALK+ and 25 ALK- systemic ALCL patients enrolled between 1996 and 2006.The relationship of these apoptosis-regulating proteins with NPM-ALK status was also evaluated with the tyrosine inhibitor herbimycin A (HA) in vitro by immunocytochemistry,Western blotting and flow cytometric assays.Results The presence of Hsp90α-,MDM2-,Bax-,Cytochrome C,and Cleaved caspase3-positive tumor cells was found significantly different in ALK+ and ALK- ALCLs,which was correlated with highly favorable clinical outcome.The Bcl-2- and p53-positive tumor cells were found in groups of patients with unfavorable prognosis.Inhibition of NPM-ALK by HA could reactivate the p53 protein and subsequent apoptosis-related proteins and therefore induced apoptosis in ALK+ ALCL cells.Conclusion Our results suggest that these seven proteins might be involved in apoptosis regulation and associated with clinical outcome of ALK+ systemic ALCLs.We also reveal a dynamic chain relation that NPM-ALK regulates p53 expression and subsequent apoptosis cascade in ALK+ ALCLs.
Objective To analyze the sensitivity of effect factors between the PCL-C and the SCL-90,to provide evidence for social psychological crisis screening and post-trauma interventions.Methods We administered the PCL-C and SCL-90 to screen for PTSD and other psychological problems among students who survived the disaster and continued their school studies.The surveys were carried out 3,6,9,and 12 months after the earthquake.A bivariate 2-level logistic model was used to explore the different levels of sensitivity among students.The factors influencing the relationships between PTSD and depression,and between PTSD and anxiety were examined.Results We analyzed data from 1 677 students,revealing that female students in higher grades were more likely to exhibit symptoms of depression,rather than PTSD,compared with the control group (males in lower grades),and the difference was significant (P＜0.05).In contrast,ethnic minorities were more likely to exhibit PTSD symptoms compared to the others.In addition,female students were more likely to exhibit symptoms of anxiety than PTSD.Other effects that did not reach statistical significance were suggested to have a similar influence on PTSD,depression,and anxiety.Conclusion After a natural disaster,specific aspects of depression and anxiety should be examined,avoiding an overemphasis on PTSD in social psychological crisis interventions.
Objective Although stressful life events represent an etiologic factor of mental health problems in adolescents,few studies have been conducted to address mechanisms linking the stress-psychopathology relation.The present study was designed to examine coping as a mediate factor on the relationship between stressful life events and symptoms of anxiety and depression.Methods The participants were 13 512 students from eight cities of China,who participated in a school-based survey.Data were collected by a questionnaire comprising coping,stressful life events,anxiety,and depressive symptoms.As a model,a series of regression equations were used to examine whether coping mediated the association between stressful life events and symptoms of anxiety and depression.Results Each dimension of stressful life events showed significant correlation with anxiety,depression and coping (all P＜0.001).In the model to analyze mediate effects,all standardized coefficients (β) were significant (all P＜0.01),indicating marked mediator effects.Furthermore,negative coping might account for more mediate effects than positive coping on this relationship.Conclusion Coping partially mediated the relationship between stressful life events and mental health during adolescence.This study highlighted an important public health priority for preventive interventions targeting stress-related psychopathology,and for further promoting adolescents＇ mental health.
Objective To determine the effects of water hardness on the toxicities of cobalt (Co) and nickel (Ni) to a freshwater fish,Capoeta fusca.Methods Toxicity was investigated by static bioassay.Fish were exposed to cobalt (as CoCl2) and nickel (as NiCl2) for 96 h in waters with two levels of hardness (“hard” and “very hard”,nominally 130 mg/L and 350 mg/L as CaCO3,respectively).Results Water hardness had a significant effect on the acute toxicity of both elements.The 96 h LC50 values for Co were 91.7 mg/L and 204.8 mg/L in hard and very hard waters,respectively,and for Ni the 96 h LC50 values were 78.0 mg/L and 127.2 mg/L,respectively.Conclusion The fish were more sensitive to Co and Ni toxicity in hard water than in very hard water;very hard water protects C.fusca against the toxicity of Co and Ni.
Objective This study aims to investigate and compare the toxic effects of four types of metal oxide (ZnO,TiO2,SiO2,and Al2O3) nanoparticles with similar primary size (～20 nm) on human fetal lung fibroblasts (HFL1) in vitro.Methods The HFL1 cells were exposed to the nanoparticles,and toxic effects were analyzed by using MTT assay,cellular morphology observation and Hoechst 33 258 staining.Results The results show that the four types of metal oxide nanoparticles lead to cellular mitochondrial dysfunction,morphological modifications and apoptosis at the concentration range of 0.25-1.50 mg/mL and the toxic effects are obviously displayed in dose-dependent manner.ZnO is the most toxic nanomaterials followed by TiO2,SiO2,and Al2O3 nanoparticles in a descending order.Conclusion The results highlight the differential cytotoxicity associated with exposure to ZnO,TiO2,SiO2,and Al2O3 nanoparticles,and suggest an extreme attention to safety utilization of these nanomaterials.
Objective To investigate the association of polymorphisms of STAT6 gene and air pollutants of PM10,NO2,and SO2,with asthma in Chinese children.Methods 418 subjects aged 14 years and under were recruited in a case-control study.The association between STAT6 polymorphisms and childhood asthma were tested by allele frequency,genotype analysis,and MDR analysis.Exposure to outdoor air pollutants was estimated by a 5-day moving average level.Statistical analyses were performed with SAS 9.1 software.Results Only 3 alleles of GT repeats at exon 1 of STAT6 were found in Chinese children.C258T and T710C were 2 new SNPs of STAT6 at 3′-UTR.Children who carried T allele of C258T were more common in asthma children than in control subjects (P＜0.05).The MDR analysis showed that GT repeats,C258T and T710C of STAT6 polymorphisms interacted together in leading to susceptibility to childhood asthma among Chinese people.After confounding factors were controlled,such as SNP C258T,family history of asthma,frequency of influenza within a year,the 5-day average of SO2 was tested to be a key risk factor of asthma in Chinese children (P＜0.05).Conclusion Chinese children differed in polymorphisms of STAT6 and in its relation with childhood asthma.
Objective To explore the relationship between polymorphisms of interleukin-4 (IL-4) gene (-33,+45,intron3,+429,+448) and the susceptibility of silicosis.Methods A case-control study was carried out.101 silicosis patients were selected as cases.As strictly matching,121 of non silicosis workers were selected as the controls.The polymophisms of IL-4 (five locus) were detected by the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques.Results The GA genotype in the IL-4+429 locus and the CC genotype in the IL-4+448 locus were found.The frequencies ofAA,GG and AG of IL-4+45 locus in the cases were 55.4％,10.9％,and 33.7％ and in the controls were 62.0％,11.6％,and 26.4％.The differences between cases and controls were not significant.The frequencies of B1B1,B2B2,and B1B2 of intron3 VNTR locus in the cases were 73.3％,1.0％,and 25.7％ and in the controls were 68.6％,1.7％,and 29.8％.The differences were not significant.The frequencies of TT,CC,and CT in -33 locus in the cases were 55.4％,11.9％,and 32.7％ and in the controls were 69.4％,4.1％,and 26.4％.The differences were significant (P=0.034).Conclusion The relationship between genetic polymorphism of IL-4-33 site and silicosis has been found and -33TT is a protective genotype for silicosis.
Objective To investigate the relationship between cytochrome P4501A1 (CYP1A1) Msp I gene polymorphism and childhood acute leukemia (AL).Methods Relevant literature was extensively searched and screened by Pubmed and Wanfang Database,Chinese Science Journal Database and Chinese Journal Net.Various data consolidation,combined OR values and their 95％ Cl were tested by RevMan 4.2; Funnel plots were used for the bias analysis.Results Six related literatures were found to meet the requirements.According to heterogeneity results,there was no significant difference in homozygous types(P＞0.05),while there was significant difference in two others types (P all＜0.05).For wild CYP1A1Mspl homozygous for the reference group,Combined OR of heterozygous mutation,homozygous,heterozygous + homozygous mutation in AL and control groups were 1.18,0.96,and 1.10 respectively.Subgroup analysis:Z values of CYP1A1Mspl homozygous,heterozygous + homozygous in the acute lymphoblastic leukemia (ALL) and the control group were 0.10 and 0.76 respectively,Z values in non-acute lymphoblastic leukemia and control group were 0.74 and 0.75.Conclusion There is no correlation between CYP1A1Mspl gene polymorphism and the susceptibility of childhood AL.
Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae.Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9(3)4],including the ratio of buffer solution (Na2B4O7 · 10H2O) to raw material,concentration of Fructus Gardeniae in extracting solution,extraction time and pH of buffer solution.An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample.Results The maximum extraction yield of the crude extract was 5.0533 (mg/g) after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4％,the concentration of Fructus Gardeniae in the extraction solution was 1/12 (g/mL),and pH of buffer solution was 4.5.The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid,and FTIR measurements also identified the presence of flavonoid in the extracts.Conclusion This work is expected to provide a basis for further research,development,and utilization of Fructus gardenia in flavonid extraction.
A strain of Flavobacterium lindanitolerans isolated from a sick child's ascites was described.The 16S rRNA gene of the strain was 100％ identical to that of Flavobacterium lindanitolerans which was first identified in India in 2008.It was first described that the isolate required X factor (Hemin) for growth in the optimal conditions of 37 ℃ with 5％ CO2.The isolate produced indole and H2S.It did not present hemolytic feature on blood agar.