Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction / 南方医科大学学报

OBJECTIVE@#To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.@*METHODS@#A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.@*RESULTS@#The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).@*CONCLUSION@#SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Overview of systematic reviews on Shenmai Injection in prevention and treatment of diseases / 中国中药杂志

To summarize and evaluate the efficacy and safety of Shenmai Injection in the treatment of viral myocarditis, shock, pulmonary heart disease, coronary heart disease, neutropenia and tumor chemotherapy, so as to provide supportive evidences for clinical rational use of Shenmai Injection. By searching literatures about studies on the systematic reviews on Shenmai Injection in treatment of viral myocarditis, shock, pulmonary heart disease, coronary heart disease, neutropenia and tumor chemotherapy from the main Chinese and English databases. Primary efficacy and safety outcome measures were selected for comparative analysis and summary, and the appraisal tool of AMSTAR 2 was used to evaluate the included studies.A total of 36 systematic reviews(published from 2005 to 2020) were included, involving viral myocarditis, shock, pulmonary heart disease, malignant tumor and coronary heart disease. The number of cases included in each type of the above diseases was 3 840, 2 484, 12 702, 28 036 and 27 082, respectively. The comparison results showed that, Shenmai Injection combined with conventional/western medicine treatment groups had better efficacy than conventional/western medicine groups alone in the prevention and treatment of the above five diseases. The main adverse reactions of Shenmai Injection reported in the included studies were facial flushing, rash, palpitation, etc., but the incidence was low and the general symptoms were mild, so no special treatment was needed. Therefore, the application of Shenmai Injection on the basis of conventional treatment or western medicine treatment had better prevention and treatment efficacy of the diseases. It was suggested that more multi-center and larger sample-size randomized controlled trials should be carried out in the future, and the relevant reporting standards should be strictly followed in systematic reviews, so as to improve the scientificity and transparency of the study.

Application of convolute manipulation for the treatment of femoral fractures in children / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the application of convoluted manipulation in pediatric femoral fractures.</p><p><b>METHODS</b>From March 2015 to October 2016, 12 children with femoral fractures were treated by Chinese traditional manipulation including 8 males and 4 females with an average age of 6 years old ranging from 1 to 12 years old. The causes of injury were falls in 10 cases and traffic accidents in 2 cases. Of which 1 case was transverse fractures, 4 cases were oblique fractures and 4 cases were spiral fractures, 2 cases were comminuted fracture, 1 case was greenstick fracture. All patients underwent manual reduction within 1 to 2 days, plus small splint with cedar bark, and parallel lower limb traction.</p><p><b>RESULTS</b>All the 12 patients were followed up for 1-3 months, with an average of 2 months. All the 12 patients achieved clinical union, and the average healing time was 6 weeks. There was no obvious shortening and rotational angulation. At the last follow-up, Schatzker-Lambert distal femoral fracture evaluation results were excellent in 11 cases, good in 1 case.</p><p><b>CONCLUSIONS</b>Convoluted manipulation is very important for reduction of femoral fractures in children, with the splint of cedar bark, satisfactory therapeutic effect can be achieved.</p>

Identification of origin plant of Uygur medicine mulberry based on DNA barcode / 中国中药杂志

To provide molecular evidence for medical material identification, we analyzed the nucleotide sequence of ITS2, psbA-trnH gene in Morus genus plants and commercial products which were obtained from different places in Xinjiang. The sequence of ITS2 and psbA-trnH in fifty-one samples were amplified and sequenced, MEGA 6.0 was used to analyze the intra- and interspecific K-2P distances, neighbor-joining (NJ) tree was used to constructing clustering tree. ITS2 sequence analyzed results showed that there is no intra-specific variation among Morus alba, M. alba var. tatarica and M. nigra, but 13 variations sites were exist between M. alba and M. nigra and their inter-specific K-2P distances was 0.04, which indicated that there had significant variation in them. We didn't find informative variation sites between Morus genus plants and commercial products, and we also found that M. nigra can be distinguished from other two species by NJ Tree. PsbA-trnH analysis results showed there was only one variation site between M. alba and M. nigra, but insertion or deletion variation were remarkable evidence among M. alba, M. alba var. tatarica and M. Nigra. Inter-specific variation was accordance with intra-specific variation of commercial products. So ITS2 and psbA-trnH gene were important marker for M. alba, M. alba var. tatarica and M. nigra identification. This study provided important evidence for Uygur medicine identification and market supervision.

Efficacy of mild hypothermia for the treatment of patients with cardiac arrest / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Therapeutic hypothermia has been recommended for the treatment of cardiac arrest patients who remain comatose after the return of spontaneous circulation. The aim of this study was to evaluate the effectiveness and safety of mild hypothermia on patients with cardiac arrest by conducting a meta-analysis.</p><p><b>METHODS</b>The relevant trials were searched in Cochrane Library, PubMed, Web of Science, Embase, CNKI and Wan Fang Data from the date of their establishment to October 2014. Thereafter, the studies retrieved were screened based on predefined inclusion and exclusion criteria. Data were extracted, and the quality of the included studies was evaluated. A meta-analysis was conducted using the Cochrane Collaboration Review Manager 5.2 software.</p><p><b>RESULTS</b>Six randomized controlled trials involving 531 cases were included, among which 273 cases were assigned to the treatment group and the other 258 cases to the control group. The meta-analysis indicated that mild hypothermia therapy after cardiac arrest produced significant differences in survival rate (relative risk [RR] =1.23, 95% confidence interval [CI]: 1.02-1.48, P = 0.03) and neurological function (RR = 1.33, 95% CI: 1.08-1.65, P = 0.007) after 6 months compared with normothermia therapy. However, no significant differences were observed in the survival to the hospital discharge (RR = 1.35, 95% CI: 0.87-2.10, P = 0.18), favorable neurological outcome at hospital discharge (RR = 1.53, 95% CI: 0.95-2.45, P = 0.08) and adverse events.</p><p><b>CONCLUSIONS</b>The meta-analysis demonstrated that mild hypothermia can improve the survival rate and neurological function of patients with cardiac arrest after 6 months. On the other hand, regarding the survival to hospital discharge, favorable neurological outcome at hospital discharge, and adverse events, our meta-analysis produced nonsignificant results.</p>

Seroepidemiological investigation of lyme disease and human granulocytic anaplasmosis among people living in forest areas of eight provinces in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Lyme disease and Human granulocytic anaplasmosis are tick-borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum.</p><p><b>METHODS</b>Forest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA).</p><p><b>RESULTS</b>Seroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks.</p><p><b>CONCLUSION</b>We conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.</p>

Comparison of lipopolysaccharide and protein immunogens from pathogenic Yersinia enterocolitica bio-serotype 1B/O:8 and 2/O:9 using SDS-PAGE / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Yersinia enterocolitica is an extracellular pathogen and its related antigens interact with the host immune system. We investigated the difference in immunological characteristics between a highly pathogenic and poorly pathogenic strain of Y. enterocolitica.</p><p><b>METHODS</b>We used SDS-PAGE and western blotting to characterize lipopolysaccharide (LPS), Yersinia outer membrane proteins (Yops), membrane proteins, and whole-cell proteins from poorly pathogenic Y. enterocolitica bio-serotype 2/O:9, isolated from China, and highly pathogenic bio-serotype 1B/O:8, isolated from Japan.</p><p><b>RESULTS</b>These two strains of Y. enterocolitica had different LPS immune response patterns. Comparison of their Yops also showed differences that could have accounted for their differences in pathogenicity. The membrane and whole-cell proteins of both strains were similar; immunoblottting showed that the 35 kD and perhaps the 10 kD proteins were immunogens in both strains.</p><p><b>CONCLUSION</b>The major antigens of the two strains eliciting the host immune response were the LPS and membrane proteins, as shown by comparing protein samples with reference and purified preparations.</p>

Development of a singleplex PCR assay targeting O-antigen modification genes for molecular serotyping of Shigella flexneri / 中华流行病学杂志

Objective To develop a singleplex PCR assay targeting O-antigen modification genes for molecular serotyping of Shigella (S.)flexneri.Methods Eight pairs of primer for O-antigen synthesis and modification genes of S.flexneriwere designed and used for developing an O-antigen modification gene-specific singleplex PCR assay to serotype 14 most common S.flexneri serotypes (1 a,1 b,1 c,2a,2b,3a,3b,4a,4b,5a,Y,X,Xv and F6).Bacterial pathogens which causing diarrheal disease were used for specificity detection.106 S.flexneri clinical isolates were serotyped by this method and compared with the slide agglutination method.Results An O-antigen modification,gene-specific singleplex PCR was developed.When six singleplex PCR reactions were performed,14 of the 15 recognized S.flexneri serotypes were identified,except for serotype Xv.The detection threshold ranged from 10 pg to 1 ng DNA in a 20 μ l reaction system.A high concordance between the singleplex PCR assay and slide agglutination were observed when 106 S.flexneri strains of various serotypes were analyzed with an exception that 1 serotype Y strain showed that it was carrying the additional defective gtr Ⅱ genes.Conclusion This method showed advantages over the traditional slide agglutination methods,and was promising when under application in the following situations as clinical diagnosis.

Establishment and comparison of pulsed-field gel electrophoresis, multiple-locus variable number tandem repeat analysis and automated ribotyping methods for subtyping of Citrobacter strains / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To establish and compare the pulsed-field gel electrophoresis (PFGE), multiple-locus variable number tandem repeat analysis (MLVA) and automated ribotyping for subtyping of Citrobacter strains.</p><p><b>METHODS</b>PFGE protocol was optimized in terms of plug preparation procedure, restriction enzymes and configuration of electrophoretic parameters. MLVA method was evaluated by finding variable number tandem repeats in two genomes of Citrobacter strains. The ribotyping was performed by using the automated RiboPrinter system.</p><p><b>RESULTS</b>We optimized the plug preparation procedure, focused on the cell suspension concentration (turbidity of 2.5 to 3.5), SDS addition (no SDS needed) and lysis time (1 h), and selected the appropriate restriction enzyme (XbaI) and the electrophoretic parameters (1.0 s-20.0 s for 19 h) of PFGE. There was nearly no discriminatory power of MLVA between Citrobacter strains. For 51 Citrobacter strains, automated ribotyping gave a D-value of 0.9945, while PFGE gave a D-value of 0.9969. Both PFGE and automated ribotyping clustered strains from the same sources (with the same species from the same place at the same time identified as the same source) and divided strains from different sources (from different years, places and hosts) into different subtypes.</p><p><b>CONCLUSION</b>PFGE protocol established in this paper and automated ribotyping are suitable for application in Citrobacter subtyping.</p>

Identification of Haemaphysalis longicomis and Rhipicephalus microplus / 中华流行病学杂志

Objective To establish a method combined morphology and molecular marker for identifying Haemaphysalis longicomis and Rhipicephalus microplus. Methods Ticks were collected from domestic animals and wild environment in epidemic area of Hubei and Henan provinces where cases of fever with thrombocytopenia syndrome were prevalent. We classified the ticks by morphology characteristics before 12S rDNA of ticks were amplified by PCR and subsequently sequenced. Phylogenetic tree was constructed by PAUP4.0. Results The ticks belonged to Haemaphysalis longicomis and Rhipicephalus microplus through observation and analysed by the morphological characteristics of the ticks. 12S rDNA was cloned and sequenced while data confirmed the morphological identification of the results. Conclusion The method based on morphology that combined with molecular marker seemed a good method for the identificaton of ticks.

Study on the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains / 中华流行病学杂志

Objective To study the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains. Methods A series of primers were designed based on potential integration site of SfII and SfX prophages in Shigella flexneri serotype 2b strains, and PCR were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. PCR products were sequenced to identify integration sites and arrangement of SfII and SfX. Results In all the serotype 2b strains, prophage SfII and SfX were adjacent to each other, and integrated into the thrW tRNA gene of the host, which were located between genes proA and yaiC of host. Prophage SfX was located immediately upstream of prophage SfII in all the detected 50 serotype 2b strains exception for strain 51251. Conclusion This was the first report on the integration site and arrangement of serotype-converting prophages SfII and SfX in Shigella flexneri 2b strains.

Population pharmacokinetic modeling and evaluation of propofol from multiple centers / 药学学报

In order to successfully develop the effective population pharmacokinetic model to predict the concentration of propofol administrated intravenously, the data including the concentrations across both distribution and elimination phases from five hospitals were analyzed using nonlinear mixed effect model (NONMEM). Three-compartment pharmacokinetic model was applied while the exponential model was used to describe the inter-individual variability and constant coefficient model to the intra-individual variability, accordingly. Covariate effect including the body weight on the parameter CL, V1, Q2, V2, Q3 and V3 were investigated. The performance of final model was assessed by Bootstrapping, goodness-of-fit and visual predictive checking (VPC). The context-sensitive half-times and the infusion rates necessary to maintain the concentration of 1 microg x mL(-1) were simulated to six subpopulations. The results were as follows: the typical value of CL, V1, Q2, V2, Q3 and V3 were 0.965 x (1 + 0.401 x VESS) x (BW/59)(0.578) L x min(-1), 13.4 x (AGE/45)(-0.317) L, 0.659 x (1 + GENDER x 0.385) L x min(-1), 28.8 L, 0.575 x (1 + GENDER x 0.367) x (1 - 0.369 x VESS) L x min(-1) and 196 L respectively. Coefficients of the inter-individual variability of CL, V1, Q2, V2, Q3 and V3 were 29.2%, 46.9%, 35.2%, 40.4%, 67.0% and 49.9% respectively, and the coefficients of residual variability were 24.7%, 16.1% and 22.5%, the final model indicated a positive influence of a body weight on CL, and also that a negative correlation of age with V1. Q2 and Q3 in males were higher than those in females at 38.5% and 36.7%. The CL and Q3 were 40.1% increased and 36.9% decreased in arterial samples compared to those in venous samples. The determination coefficient of observations (DV)-individual predicted value (IPRED) by the final model was 0.91 which could predict the propofol concentration fairly well. The stability and the predictive performance were accepted by Bootstrapping, the goodness-of-fit and VPC. The context-sensitive half-times and infusion rates necessary to maintain the concentration of 1 microg x mL(-1) were different obviously among the 6 sub-populations obviously. The three-compartment model with first-order elimination could describe the pharmacokinetics of propofol fairly well. The involved fixed effects are age, body weight, gender and sampling site. The simulations in 6 subpopulations were available in clinical anesthesia. The propofol anesthesia monitor care could be improved by individualization of pharmacokinetic parameter estimated from the final model.

Influence of acid stimulation on expression of acid-sensing ion channel 1a and 3 in type I cells of rat carotid body / 生理学报

The experiments were carried out to test whether acid-sensing ion channel 1a and 3 (ASIC1a and ASIC3) were expressed on the primarily cultured type I cells of rat carotid bodies (CBs) and whether the expression of the channels was affected by acid stimulation. The Sprague-Dawley rats of either sex (50-100 g) were used. The CBs were isolated and primarily cultured. The immunofluorescent technique was used to detect the expression of tyrosine hydroxylase (TH), a specific marker of type I cells, in order to identify the type of the cultured cells. The double-label immunofluorescent technique was used to detect the expression of ASIC1a and ASIC3 on the TH-positive type I cells. To detect the influence of acid stimulation on the expressions of ASIC1a and ASIC3, each batch of primarily cultured cells were randomly divided into pH7.3 group (control group), pH6.8 group and pH6.2 group (n=9 in each group). The cells in above three groups were treated with pH7.3, pH6.8 and pH6.2 mediums for 24 h, respectively, and then the mRNA expressions of ASIC1a and ASIC3 in type I cells were detected by semi-quantitative RT-PCR technique. The results showed that more than 93% of the primarily cultured CB cells were TH-positive, indicating that most of the cultured cells were type I cells. Furthermore, all TH-positive cells expressed ASIC1a or ASIC3. After the cells were treated with acid stimulation, the amount of ASIC1a mRNA did not change significantly (P>0.05 vs control group); the amount of ASIC3 mRNA had no significant change in pH6.8 group compared with that in control group, but decreased significantly in pH6.2 group (P<0.01 vs control group, P<0.05 vs pH6.8 group). It is concluded that acid stimulation down-regulates the level of ASIC3 mRNA, but has no effect on the level of ASIC1a mRNA.

Secretion expression of cholera toxin B subunit in food-grading Lactococcus lactis expression system / 中华流行病学杂志

<p><b>OBJECTIVE</b>To clone and secretion express cholera toxin B subunit (CTB) in food-grading Lactococcus lactis expression systems.</p><p><b>METHODS</b>ctB fragment that encoding CTB was amplified by polymerase chain reaction (PCR) using the genomic DNA of Vibrio cholera strain 569B as template and was inserted into two secretion expression vector pSQZ and pSQ to construct food-grading expression system L.lactis MBP71/pSQZ-ctB and L.lactis MBP71/pSQ-ctB. The expressed CTB was detected by Western-blot assay.</p><p><b>RESULTS</b>The ctB fragment was successfully amplified from Vibrio cholera strain 569B and inserted into two secretion expression vectors pSQZ and pSQ to construct food-grading expression system L. lactis MBP71/pSQZ-ctB and L. lactis MBP71/pSQ-ctB. Western-blot assay demonstrated that CTB was secretion and expressed from L.lactis MBP71 harboring vectors pSQZ-ctB and pSQ-ctB, and the quantity of CTB secreted by L. lactis MBP71/pSQ-ctB was about 2 microg/ml, higher than that of L. lactis MBP71/pSQZ-ctB.</p><p><b>CONCLUSION</b>CTB was successfully secreted and expressed by food-grading L. lactis expression systems.</p>

Effect of glutamine on serum interleukin-8 and tumor necrosis factor-alpha levels in patients with severe pancreatitis / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the changes in serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) after intravenous administration of alanyl-glutamine (Gln) in patients with severe pancreatitis.</p><p><b>METHODS</b>Fifty patients with severe pancreatitis were randomized equally into 2 groups and received standard total parenteral nutrition (TPN) with intravenous infusion of Gln or normal saline (control) for 1 week. The plasma glutamine level was measured with high-performance liquid chromatography (HPLC) in these patients one day before and on day 7 of Gln administration, and the serum IL-8, TNF-alpha and heat shock protein 70 (Hsp70) were detected with enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>On day of Gln administration, the plasma glutamine level in patients of Gln group increased significantly (P<0.01), and serum IL-8 and TNF-alpha levels decreased significantly (P>0.05) in comparison with those of the control group. The patients receiving Gln supplementation had significantly higher serum albumin level and greater body fat content with shorter hospital stay than those in the control group (P<0.05), and the mortality rate in Gln group was also significantly lower (P<0.05).</p><p><b>CONCLUSION</b>Gln-enriched TPN may improve the clinical outcomes of patients with severe pancreatitis probably by decreasing serum IL-8 and TNF-alpha levels.</p>

Purification technology of Rhizoma et Radix Notopterygii and Radix Angelicae Pubescentis in Fufang Xuelian dropping pills by macroporous resin / 中国中药杂志

<p><b>OBJECTIVE</b>To study the purification technology of Rhizoma et Radix Notopterygii and Radix Angelicae Pubescentis in Fufang Xuelian dropping pills by macroporous resin.</p><p><b>METHOD</b>Taking osthole, isomperatorin as index ingredients, the type of resin sampling amount and elution solvent were decided, and the influence of sample concentration pH of sample and ratio of diameter to height of column to adsorption were studied.</p><p><b>RESULT</b>HPD400A was chosen to purify, the suitable sampling ratio of resin volume to raw material was 1:2; pH 3.5 (crude drug) and ratio of diameter to height was 1:7; 95% ethanol of the elution solvent was satisfactory eluant for desorption.</p><p><b>CONCLUSION</b>HPD400A macroporous resin can be used to purify Rhizoma et Radix Notopterygii and Radix Angelicae Pubescentis.</p>

Molecular epidemiology of enterohaemorrhagic Esacherichia coli O157 in some areas in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the epidemiological characteristics of enterohaemorrhagic Escherichia coli (EHEC) O157 and to determine the degree of its genetic relations.</p><p><b>METHODS</b>Polymerase chain reaction (PCR) techniques and chromosomal DNA digested by restriction enzyme Xba I according to PulseNet directions by pulsed field gel electrophoresis (PFGE) method were applied to 300 E. coli O157 strains isolated from patients and animal sources from 1988 to 2005 from Henan, Jiangsu and Anhui provinces.</p><p><b>RESULTS</b>Very high prevalence of stx2 gene in EHEC O157:H7 strains isolated from some provinces of China was found and variation existed in some strains. We got 161 PFGE patterns from 300 strains. The stx2-producing strains could be clearly separated from stx2 variation-producing strains.</p><p><b>CONCLUSION</b>The variability of restriction enzyme-digestion patterns of O157 genomes suggested that the presence of some genomic diversity among the strains did exist.</p>

Immunoproteomic assay of secretive proteins from Streptococcus suis type 2 strain SC84 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To identify antigenic proteins secreted by Streptococcus suis (S. suis) type 2 strain SC84.</p><p><b>METHODS</b>Two-dimensional electrophoresis (2-DE), western-blot assay and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis were performed to search and identify antigenic proteins secreted by S. suis strain SC84, which triggered an outbreak of the disease in Sichuan province,China, in 2005.</p><p><b>RESULTS</b>A total number of 14 western blot spots were found on PVDF membrane. 11 spots which could be found the existence of matching protein on coomassie G-250-stained 2-DE gel were identified by MALDI-TOF MS. The 11 proteins, all located at extra-cellular or cell wall, were classified into 8 kinds of proteins. Among of them, muramidase-released protein (MRP), suilysin (Sly) and extra-cellular factor (EF) were the known antigenic proteins, but several proteins such as putative 5'-nucleotidase, ribo-nucleases G and E, and predicted metal-loendo-peptidase were newly found antigenic proteins. All the identified protein were found to have had the coding gene in genomic of S. suis strain 05ZYH33, isolated from patients in Sichuan province, China in 2005.</p><p><b>CONCLUSION</b>The newly found proteins could be used as voluntary antigens for detection and vaccination of S. suis.</p>

Clone and express ctb-stx2 b fusion gene in Enterohemrrhagic escherichia coli O157:H7 Shigeai toxin 2B subunit and V cholera toxin B subunit and the detection of their immunogenicity / 中华流行病学杂志

Objective To clone and express the fusion gene encoding Enterohemrrhagic escherichia coli O157:H7(EHEC O157:H7)Shigela toxin 2B subunit(Stx2B)and vibrio cholera toxin B subunit (CTB)as well as to detect the immunogenicity and GM1-binding ability of fusion protein.Methods To design a primer to amplify stx2b gene and ctb-stx2b fusion gene encoding Stx2B and CTB-Stx2B respectively and to clone the genes into express plasmid pET30a(+)C in order to construct pET30a-ctb-stx2b after T-A sequencing was varified,then to transform constructed plasmid into E.coliBL21(DE3)induced by IPTG and purified by a purify kit and to detect molecular weight and immunogenicity by SDSPAGE and Western-blot.Results The amplified ctb-stx2b fragments appeared to he 750 bp and gene sequence was identical to designed sequence.The prokaryotic expression system pET30a-ctb-stx2b/BL21 could express protein weight about Mr20×103and the expressed protein could react to CTB monoclone anti-body.The fusion protein CTB-Stx2B could bind GM1.Conclusion CTB-Stx2B had successfully been expressed in prokaryotic while the expressed protein had good immunogenicity and GM1-Binding ability.This study provided information on further EHEC O157:H7 vaccine research.

Development of a protocol on pulsed field gel electrophoresis analysis for Streptococcus suis / 中华流行病学杂志

Objective To develop a PFGE protocol for Streptococcus suis.Methods We developed and optimized a PFGE protocol for S.suis,in terms of plug preparation,choice of restriction endonucleases and optimized electrophoresis parameters.By analyzing the genome sequences of S.suis P1/7 with Mapdraw of DNAStar.we found three restriction enzymes,Swa Ⅰ,Sma Ⅰ and Apa Ⅰ,were more suitable than others.Results Analysis of 100 isolates of S.suis including 34 of 35 serotypes identified,59,53 and 43 patterns were obtained from Swa Ⅰ,Sma Ⅰ and Apa Ⅰ restriction,respectively.The enzyme Swa Ⅰ had the greatest power for discrimination ability.Conclusion By optimization of the protocol at various conditions,a rapid,reproducible,economic and practical PFGE method for S.suis was developed.