Relationship between different types of helicobacter pylori infection and metabolic syndrome in healthy people / 中国综合临床

Objective:To explore the relationship between different types of helicobacter pylori (Hp) infection and metabolic Syndrome (MS) in healthy population.Methods:The data of 4 602 adults who underwent physical examination in the Space Center Hospital from January to December 2019 were collected for research, the serum Hp antibody typing was detected by immunoblotting, and the results of liver ultrasound and blood biochemical examination were collected for statistical analysis.Results:Among the physical examination population,there were 2 018 cases with positive serum Hp antibody and 2 584 cases with negative serum Hp antibody.According to the expression of cytotoxin-associated gene A protein (CagA) and vacuolar toxin, 2 018 patients with positive serum Hp antibody were divided into 1 088 cases in type Ⅰ group (53.9%(1 088/2 018)) and 930 cases in type Ⅱ Group (46.1%(930/2 018)). There were significant differences in age, systolic blood pressure and prevalence of nonalcoholic fatty liver disease (NAFLD) between type Ⅰ group and type Ⅱ Group ( P<0.05). There was no significant difference in gender, fasting blood glucose, triglyceride,high-density lipoprotein cholesterol (HDL-C), diastolic blood pressure, body mass index (BMI) and waist circumference between the two groups ( P>0.05). There was no significant difference in the prevalence of ms between the two groups (18.3% (199/1 088)) and 19.0%(177/930), P=0.670). Multivariate logistic regression analysis showed that there was no correlation. between different serum Hp antibody typing and MS ( OR=1.194,95% CI 0.842-1.693, P=0.319). Conclusion:Different subtypes of type Ⅰ and type Ⅱ Hp infection are not distinctly associated with metabolic syndrome.

Analysis of the relationship between Helicobacter pylori cytotoxin-associated gene A, Helicobacter pylori isolate vacuole-forming toxin gene A and gastric cancer occurrence and clinicopathological factors / 中国医师进修杂志

Objective:To investigate the relationship between Helicobacter pylori(HP) cytotoxin-associated gene A (HP-CagA), HP isolate vacuole-forming toxin gene A (HP-VacA) and gastric cancer occurrence and clinical pathological factors.Methods:Eighty-eight patients with gastric cancer from January 2018 to January 2020 in Suzhou Hospital Affiliated of Anhui Medical University was selected as the observation group, 80 patients with benign gastric lesions during the same period was selected as the benign control group, and 80 healthy patients was selected as the healthy control group. The clinical data, HP-CagA, HP-VacA positive expression rates of the three groups were compared, the risk factors of gastric cancer were analyzed, and the relationship between HP-CagA, HP-VacA and gastric cancer clinicopathological factors were evaluated.Results:Family history of gastric cancer, high-salt diet, preference for hot food, decreased pepsinogen (PG)Ⅰ/PGⅡ, combined with fatty liver, increased triglyceride, total cholesterol and low density lipoprotein cholesterin, smoking and depression were risk factors of gastric cancer ( P<0.05). The positive rate of HP-CagA, HP-VacA in the observation group were higher than those in the benign control group and the healthy control group: 82.93%(73/88) vs. 62.50%(50/80) and 26.25%(21/80), 30.68%(27/88) vs. 7.50%(6/80) and 0, the differences were statistically significant ( P<0.05). The positive of HP-CagA and HP-VacA had correlation with age, pathological type, and degree of differentiation of gastric cancer ( P<0.05). The 1-year survival rate of HP-CagA and HP-VacA positive patients was lower than that of negative patients by Kaplan-Meier analysis ( P<0.05). Conclusions:The positive of HP-CagA and HP-VacA in HP infections are closely related togastric cancer. Strengthening the treatment of HP infection patients with positive HP-CagA and HP-VacA has important clinical value and social significance for cutting off the early stage of gastric cancer and improving prognosis.

Correlation between the severity of peptic ulcer bleeding and Helicobacter pylori type / 中华消化杂志

Objective@#To investigate the correlation between the severity of peptic ulcer bleeding (PUB) and the serum antibody typing of Helicobacter pylori (H.pylori).@*Methods@#From January 1, 2009 to December 31, 2018, at Guangzhou First People′s Hospital, 1 444 patients diagnosed with PUB and received H. pylori serum antibody test at the same time were enrolled and divided into high-risk group (324 cases) and low-risk group (1 120 cases) according to Forrest classification, and according to recurrent bleeding, the patients were divided into recurrent bleeding group (32 cases) and non-rebleeding group (1 412 cases). Serum H. pylori specific antibodies cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA) and urease were detected by protein array. The correlation between H. pylori positive rate, H. pylori type, PUB and rebleeding were analyzed. Chi-square test and logistic regression analysis were used for statistical analysis.@*Results@#Among 1 444 PUB patients, there were 709 patients with gastric ulcer bleeding (GUB) and 735 patients with duodenal ulcer bleeding (DUB). Previous history of peptic ulcer disease (odds ratio (OR)=1.501, P=0.006), the maximum diameter of ulcer over 2 cm (OR=2.484, P<0.01) and H. pylori infection (OR=1.508, P=0.005) were independent risk factors of the severity of PUB. The total H. pylori positive rate was 68.49% (989/1 444), H. pylori type Ⅰ was the main type. Of which, 61.34% (549/895) were CagA and VacA double positive strains, 31.73% (284/895) were VacA single positive bacteria and CagA single positive bacteria was only 6.93% (62/895). The positive rate of H. pylori of high-risk group was higher than that of low-risk group (75.31%, 244/324 vs. 66.52%, 745/1 120), and the difference was statistically significant (χ2=8.999, P=0.004). In addition, the more serious Forrest classification, the higher the detection rate of H. pylori, and the difference was statistically significant (χ2=11.840, P=0.037). There was no significant difference in the positive rate of H. pylori between recurrent bleeding group and non-rebleeding group (81.25%, 26/32 vs. 68.20%, 963/1 412; χ2=2.469, P>0.05). According to H. pylori antibody type, H. pylori type Ⅰ infection was mainly in both high-risk group and low-risk group. The positive rate of H. pylori type Ⅰ strain of high-risk group was higher than that of low-risk group (67.28%, 218/324 vs. 60.45%, 677/1 120), and the difference was statistically significant (χ2=4.986, P=0.026). There was no statistically significant difference in the positive rate of H. pylori between GUB group and DUB group (68.41%, 485/709 vs. 68.57%, 504/735; χ2=0.005, P>0.05).@*Conclusions@#The infection of H. pylori is positively correlated with the severity of PUB, but not correlated with early ulcer rebleeding. H. pylori type Ⅰ is the main pathogenic strain of GUB and DUB, and CagA and VacA double positive strain is the most common strain.

Helicobacter pylori virulence factor vacuolating cytotoxin A ( VacA) promotes homologous recombi-nation repair in GES-1 cells / 中华微生物学和免疫学杂志

Objective To analyze the impact of Helicobacter pylori standard strain (Hp P12) and its virulence factor vacuolating cytotoxin A ( VacA) on DNA damage and homologous recombination ( HR) repair in a human gastric epithelial cell line (GES-1). Methods Strains of Hp P12 and vacA gene knock-out Hp P12 ( Hp P12 ΔvacA) were respectively used to infect GES-1 cells at a multiplicity of infection of 100. GES-1 cells treated with etoposide (50μmol/L) or mitomycin (0. 5μg/ml) for 2 h were used as posi-tive control. Western blot and immunofluorescence were performed to detect the expression of DNA damage marker protein γH2AX and key HR repair proteins (Rad51, pMRE11, CtIP and pCtIP) and the recruitment of them at DNA damage sites. Human embryonic kidney HEK-293 ( DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA strains to verify the impact of VacA on HR repair efficiency. Results The expres-sion and recruitment of γH2AX and key HR repair proteins ( Rad51, pMRE11, CtIP and pCtIP) were in-creased in Hp P12-infected cells as compared with that in uninfected and Hp P12 ΔvacA-infected cells ( all P<0. 05). To evaluate the HR repair efficiency, I-SceⅠ plasmid-transfected HEK-293 (DR-GFP) cells were infected with Hp P12 and Hp P12 ΔvacA and the results showed that green fluorescent protein ( GFP)-positive cells were decreased after infection, especially in Hp P12 ΔvacA-infected cells (both P<0. 05). Conclusions Hp P12 infection could cause DNA damage and promote HR repair in GES-1 cells, in which the virulence factor VacA played an important role.

Correlation between the severity of peptic ulcer bleeding and Helicobacter pylori type / 中华消化杂志

Objective To investigate the correlation between the severity of peptic ulcer bleeding (PUB) and the serum antibody typing of Helicobacter pylori (H.pylori).Methods From January 1, 2009 to December 31, 2018, at Guangzhou First People's Hospital, 1 444 patients diagnosed with PUB and received H.pylori serum antibody test at the same time were enrolled and divided into high-risk group (324 cases) and low-risk group ( 1 120 cases ) according to Forrest classification , and according to recurrent bleeding , the patients were divided into recurrent bleeding group (32 cases) and non-rebleeding group (1 412 cases).Serum H.pylori specific antibodies cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA) and urease were detected by protein array .The correlation between H.pylori positive rate, H.pylori type, PUB and rebleeding were analyzed .Chi-square test and logistic regression analysis were used for statistical analysis . Results Among 1 444 PUB patients, there were 709 patients with gastric ulcer bleeding ( GUB) and 735 patients with duodenal ulcer bleeding ( DUB).Previous history of peptic ulcer disease ( odds ratio (OR)＝ 1.501, P＝0.006), the maximum diameter of ulcer over 2 cm (OR＝2.484, P?0.01) and H.pylori infection (OR＝1.508, P＝0.005) were independent risk factors of the severity of PUB .The total H.pylori positive rate was 68.49%(989/1 444), H.pylori type Ⅰwas the main type.Of which, 61.34%(549/895) were CagA and VacA double positive strains , 31.73%(284/895) were VacA single positive bacteria and CagA single positive bacteria was only 6.93%(62/895).The positive rate of H.pylori of high-risk group was higher than that of low-risk group (75.31%, 244/324 vs.66.52%, 745/1 120), and the difference was statistically significant (χ2 ＝8.999, P ＝0.004).In addition, the more serious Forrest classification , the higher the detection rate of H.pylori, and the difference was statistically significant (χ2 ＝11.840, P＝0.037).There was no significant difference in the positive rate of H.pylori between recurrent bleeding group and non-rebleeding group (81.25%, 26/32 vs.68.20%, 963/1 412; χ2 ＝2.469, P＞0.05).According to H.pylori antibody type, H.pylori typeⅠinfection was mainly in both high-risk group and low-risk group.The positive rate of H.pylori typeⅠstrain of high-risk group was higher than that of low-risk group (67.28%, 218/324 vs.60.45%, 677/1 120), and the difference was statistically significant ( χ2 ＝4.986, P ＝0.026).There was no statistically significant difference in the positive rate of H.pylori between GUB group and DUB group (68.41%, 485/709 vs. 68.57%, 504/735; χ2 ＝0.005, P＞0.05).Conclusions The infection of H.pylori is positively correlated with the severity of PUB, but not correlated with early ulcer rebleeding .H.pylori typeⅠis the main pathogenic strain of GUB and DUB, and CagA and VacA double positive strain is the most common strain .

Effect of Helicobacter pylori virulence factor CagA-mediated activation of ERK signaling pathway on proliferation and apoptosis of gastric cancer cells / 吉林大学学报(医学版)

Objective: To explore the effect of Helicobacter pylori virulence factor cytotoxin-associated gene A protein (CagA) on the extracellular regulated protein kinase (ERK) signaling pathway, and to elucidate the carcinogenesis mechanism of CagA. Methods: The pcDNA3. 1/CagA eukaryotic expression vector was constructed, and the gastric cancer AGS cells were divided into blank control group (blank vector transfection), CagA transfection group (GZ7/CagA transfection), and CagA + ERKi group (ERK1/2 inhibitor pretreatment + GZ7/CagA transfection). The expression levels of CagA, phosphorylated ERK (p-ERK), total ERK (T-ERK), B-lymphocytoma-2 (Bcl-2), Bcl-2-related X protein (Bax) and cleaved caspase-3 proteins in the cells in various groups were determined by Western blotting method. The activities of AGS cells in various groups were determined by CCK-8 method, and the apoptotic rates of AGS cells were determined by flow cytometry. Results: Compared with blank control group, the expression levels of CagA, p-ERK, and Bel-2 proteins in CagA transfection group were significantly increased (P<0. 01), and the expression levels of Bax and cleaved caspase-3 proteins were significantly decreased (P<0. 01). Compared with CagA transfection group, the expression levels of p-ERK and Bel-2 proteins in CagA+ERKi group were significantly decreased (P<0. 01), and the expression levels of Bax and cleaved caspase-3 proteins were significantly increased (P<0. 01). Compared with CagA transfection group, the activities of gastric cancer cells in CagA + ERKi group at different time points were significantly decreased (P< 0. 01). Compared with CagA transfection group, the apoptotic rate of gastric cancer cells in CagA + ERKi group was significantly increased (P<0. 05). Conclusion: Helicobacter pylori virulence factor CagA can inhibit the proliferation of gastric cancer cells and promote the apoptosis of gastric cancer cells, and its mechanism may be related to the activation of ERK signaling pathway by CagA.

Hemolytic, anticancer and antigiardial activity of Palythoa caribaeorum venom

Background Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. Most of these studied extracts were obtained from sea anemones or jellyfish. The present study aimed to determine the toxic activity and assess the antitumor and antiparasitic potential of Palythoa caribaeorum venom by evaluating its in vitro toxicity on several models including human tumor cell lines and against the parasite Giardia intestinalis. Methods The presence of cytolysins and vasoconstrictor activity of P. caribaeorum venom were determined by hemolysis, PLA2 and isolated rat aortic ring assays, respectively. The cytotoxic effect was tested on HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma), K562 (human chronic myelogenous leukemia), U251 (human glyoblastoma), PC-3 (human prostatic adenocarcinoma) and SKLU-1 (human lung adenocarcinoma). An in vivo toxicity assay was performed with crickets and the antiparasitic assay was performed against G. intestinalis at 24 h of incubation. Results P. caribaeorum venom produced hemolytic and PLA2 activity and showed specific cytotoxicity against U251 and SKLU-1 cell lines, with approximately 50% growing inhibition. The venom was toxic to insects and showed activity against G. intestinalis in a dose-dependent manner by possibly altering its membrane osmotic equilibrium. Conclusion These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer.

Hemolytic, anticancer and antigiardial activity of Palythoa caribaeorum venom

Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. Most of these studied extracts were obtained from sea anemones or jellyfish. The present study aimed to determine the toxic activity and assess the antitumor and antiparasitic potential of Palythoa caribaeorum venom by evaluating its in vitro toxicity on several models including human tumor cell lines and against the parasite Giardia intestinalis. Methods: The presence of cytolysins and vasoconstrictor activity of P. caribaeorum venom were determined by hemolysis, PLA2 and isolated rat aortic ring assays, respectively. The cytotoxic effect was tested on HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma), K562 (human chronic myelogenous leukemia), U251 (human glyoblastoma), PC-3 (human prostatic adenocarcinoma) and SKLU-1 (human lung adenocarcinoma). An in vivo toxicity assay was performed with crickets and the antiparasitic assay was performed against G. intestinalis at 24 h of incubation. Results: P. caribaeorum venom produced hemolytic and PLA2 activity and showed specific cytotoxicity against U251 and SKLU-1 cell lines, with approximately 50% growing inhibition. The venom was toxic to insects and showed activity against G. intestinalis in a dose-dependent manner by possibly altering its membrane osmotic equilibrium. Conclusion: These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer.(AU)

The role of nuclear factor kappa B and helicobacter pylori associated protein A in the pathogenesis of idiopathic thrombocytopenic purpura / 中国基层医药

Objective To detect and analyze nuclear factor kappa B (NF-κB),Helicobacter pylori (HP),Helicobacter pylori cytotoxin associated protein A (CagA),platelet (PLT) and platelet associated IgG (PA IgG) in 224 patients with idiopathic thrombocytopenic purpur(ITP) from three urban hospitals of Shaoxing,in order to explore the role of NF-κB and CagA in the pathogenesis of ITP,then to improve the prognosis of ITP.Methods SABC method was used to detect the NF-κB,13C breath test for the determination of the Hp infection.CagA and PA-IgG were tested by enzyme linked immunosorbent assay.Automatic blood cell analyzer was used to measure PLT.According to the test results,the patients were divided into Hp+cagA+NF-κB+,Hp+cagA+NF-κB-,Hp+cagA-NF-κB+,Hp+cagA-NF-κB-,Hp-NF-κB+,Hp-NF-κB-PLT groups,and PA-IgG,PLT of the six groups were statistically analyzed.Results Of 224 cases with ITP,175 cases of HP positive,the positive rate was 78.13%.CagA+ 91 cases in 175 cases of Hp+,accounting for 52%,overall 43.63%.NF-kappa B+ 108 cases,the positive rate was 46.21%,78 cases were found in Hp+cagA+,accounting for 85.71% in cagA+.In 84 cases of Hp+cagA-,there were 21 cases NF-κB+,the positive rate was 25%.In 49 of HP-,9 cases with NF-kappa B+,accounting for 18.37%.PLT and PA-IgG were compared among the groups.The count of PLT of group Hp+,group Hp+cagA+ and group NF-κB+ was lower than group Hp-,group Hp+cagA- and group NF-κB-.However,the level of PA-IgG of group Hp+,group Hp+cagA+ and group NF-κB+ was higher than group Hp-,group Hp+cagA- and group NF-κB-,the difference was statistically significant(P<0.05).Conclusion CagA maybe directly or through the activation of NF-kappa B take part in the immune response of ITP,cause PA-IgG increased and thrombocytopenia.

Anti-bacterial effects of enzymatically-isolated sialic acid from glycomacropeptide in a Helicobacter pylori-infected murine model

BACKGROUND/OBJECTIVES: Helicobacter pylori (H. pylori) colonization of the stomach mucosa and duodenum is the major cause of acute and chronic gastroduodenal pathology in humans. Efforts to find effective anti-bacterial strategies against H. pylori for the non-antibiotic control of H. pylori infection are urgently required. In this study, we used whey to prepare glycomacropeptide (GMP), from which sialic acid (G-SA) was enzymatically isolated. We investigated the anti-bacterial effects of G-SA against H. pylori in vitro and in an H. pylori-infected murine model. MATERIALS/METHODS: The anti-bacterial activity of G-SA was measured in vitro using the macrodilution method, and interleukin-8 (IL-8) production was measured in H. pylori and AGS cell co-cultures by ELISA. For in vivo study, G-SA 5 g/kg body weight (bw)/day and H. pylori were administered to mice three times over one week. After one week, G-SA 5 g/kg bw/day alone was administered every day for one week. Tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and IL-10 levels were measured by ELISA to determine the anti-inflammatory effects of G-SA. In addition, real-time PCR was performed to measure the genetic expression of cytotoxin-associated gene A (cagA). RESULTS: G-SA inhibited the growth of H. pylori and suppressed IL-8 production in H. pylori and in AGS cell co-cultures in vitro. In the in vivo assay, administration of G-SA reduced levels of IL-1β and IL-6 pro-inflammatory cytokines whereas IL-10 level increased. Also, G-SA suppressed the expression of cagA in the stomach of H. pylori-infected mice. CONCLUSION: G-SA possesses anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect in an experimental H. pylori-infected murine model. G-SA has potential as an alternative to antibiotics for the prevention of H. pylori infection and H. pylori-induced gastric disease prevention.

Experimental study on bacteriostatic effect of recombinant human lactoferrin on Helicobacter pylori / 重庆医学

Objective To evaluate the bacteriostatic effect of recombinant human lactoferrin(rhLF) on Helicobacter(H .) py‐lori and its influence on CagA ,Ure and gastric mucosal IL‐8 .Methods The minimum inhibitory concentration(MIC)and the influ‐ence of different drug concentrations on the proliferation of H .pylori were detected .The effects of rhLF on the mRNA and protein expressions of CagA and Ure in H .pylori were detected by RT‐PCR and Western blot ,respectively .The animal study :Balb/c mice were adopted and assigned randomly into four groups ,including the standard triple+rhLF(group A) ,rhLF(group B) ,standard tri‐ple(group C) and normal saline(group D) .The histopathological HE staining was used to observe the gastric inflammation and ELISA was used to detect the IL‐8 level of gastric tissue in each group .Results MIC was 0 .5 mg/mL ,moreover rhLF inhibited the bacterial growth and proliferation with a concentration‐dependent manner .rhLF could reduce the expression of H .pylori major viru‐lence factor CagA ,mRNA and protein of Ure .Comparing the group A with the group B ,C and D ,the gastric mucosal inflammation score and the IL‐8 levels of gastric tissue homogenates had statistically significant differences(P<0 .05) .Conclusion rhLF inhibits the growth and proliferation of H .pylori ,moreover inhibit the expression of major virulence factor CagA in H .pylori ,mRNA and protein of Ure in different degrees ,weakens its pathogenicity ,meanwhile reduces the IL‐8 level in mice gastric mucosa ,and allevi‐ates H .pylori related gastric mucosal inflammatory response .

Tumor hypoxia and reoxygenation: the yin and yang for radiotherapy

Tumor hypoxia, a common feature occurring in nearly all human solid tumors is a major contributing factor for failures of anticancer therapies. Because ionizing radiation depends heavily on the presence of molecular oxygen to produce cytotoxic effect, the negative impact of tumor hypoxia had long been recognized. In this review, we will highlight some of the past attempts to overcome tumor hypoxia including hypoxic radiosensitizers and hypoxia-selective cytotoxin. Although they were (still are) a very clever idea, they lacked clinical efficacy largely because of ‘reoxygenation’ phenomenon occurring in the conventional low dose hyperfractionation radiotherapy prevented proper activation of these compounds. Recent meta-analysis and imaging studies do however indicate that there may be a significant clinical benefit in lowering the locoregional failures by using these compounds. Latest technological advancement in radiotherapy has allowed to deliver high doses of radiation conformally to the tumor volume. Although this technology has brought superb clinical responses for many types of cancer, recent modeling studies have predicted that tumor hypoxia is even more serious because ‘reoxygenation’ is low thereby leaving a large portion of hypoxic tumor cells behind. Wouldn’t it be then reasonable to combine hypoxic radiosensitizers and/or hypoxia-selective cytotoxin with the latest radiotherapy? We will provide some preclinical and clinical evidence to support this idea hoping to revamp an enthusiasm for hypoxic radiosensitizers or hypoxia-selective cytotoxins as an adjunct therapy for radiotherapy.

Cytopathic effects of toxogenic strains of Helicobacter pylori on different cell lines.

Purpose: Many virulence factors are involved in the pathomechanism of infection caused by Helicobacter pylori. Toxins such as vacuolating cytotoxin, encoded by the vacA gene and the immunogenic protein cagA, encoded by the cagA gene (cytotoxin-associated gene) are major factors conferring the property of virulence. The current study is aimed at isolation of H. pylori and separation of its toxin from antral biopsies of patients. Materials and Methods: The following cell lines were used to demonstrate the cytopathic effect (CPE) of the separated toxin: African green monkey kidney (Vero), baby hamster kidney, human lung carcinoma (LLC-MK2), and human epithelial. Results: H. pylori was isolated from 27 out of 45 patients (60%) selected for the study. CPE of H. pylori toxin was highly signifi cant on Vero cells than other cell lines used as it reached a high dilution titer of toxin (1/16) in 13 isolated strains (48.15%). No signifi cant difference in CPE of toxin in different dilutions was detected among other cell lines used in different groups. H. pylori toxin could be detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis as a distinct band with a molecular weight ranging between 66 and 97 kDa and closely related to 87 kDa. Conclusion: H. pylori vacuolating cytotoxin plays a vital role in the pathogenesis of gastroduodenal diseases (gastritis, gastric ulcer, duodenal ulcer, and gastric cancer). The Vero cell lines were found to be the most suitable form of tissue culture when compared with other cell lines used in our study for demonstrating the activity of H. pylori toxin.

Meta-analysis on the relationship between virulent strains of Helicobacter pylori and risk of atherosclerotic cerebral infarction / 中国感染控制杂志

Objective To evaluate the relationship between cytotoxin-associated gene-A (CagA)seropositive of Helicobacter pylori (H .pylori )infection and risk of atherosclerotic cerebral infarction(ACI).Methods Related literatures were researched through literature retrieval ,literatures were obtained by uniformed criteria of inclusion and exclusion,and Meta analysis was performed with RevMan 4.2 software.Results A total of 10 literatures which met the inclusion criteria were retrieved,all were case-control study,case group included 907 studied subjects,and control group included 966 subjects;the included population were divided into Chinese subgroup and European Caucasian sub-group.Meta analysis of CagA seropositive of H .pylori infection and risk of ACI revealed that OR of the overall popula-tion,Chinese subgroup,and European Caucasian subgroup was 2.66(2.17-3.26),2.60(1.93-3.49),and 2.71(2.05-3.59)respectively;Meta analysis of CagA seronegative of H .pylori infection and risk of ACI revealed that OR of the overall population,Chinese subgroup,and European Caucasian subgroup was 0.74(0.49-1.10),0.81(0.45-1.48),and 0.64(0.37-1.09)respectively.The funnel plot and fail-safe number showed that there was no significant publication bias, the result was stable and reliable.Conclusion Chronic infection caused by CagA seropositive strains of H .pylori may be one of the risk factors of CAI,whether the eradication treatment of seropositive strains of H .pylori influences the process of atherosclerotic diseases like CAI needs to be further studied.

Isolation and purification of recombinant VacA and Helicobacter pylori-secreted VacA and VacA-induced cell vacuolar change and apoptosis / 军事医学

Objective To isolate and purify VacA protein secreted by Helicobacter pylori or recombinant VacA , and to investigate the effect of VacA-induced cell vacuolar change and apoptosis .Methods VacA proteins were separated and pu-rified from the culture supernatant of H.pylori ( ATCC26695 ) or from the split products of genetically engineered bacteria (pQE30-VacA-E.coli M15) expressing recombinant VacA.The VacA protein obtained was acidified and then incubated with AGS cells for 24 h at different final concentrations of 5 and 10 ng/ml before the vacuolar change and apoptosis of AGS cells were detected via microscopy and flow cytometry assay , respectively .Results H.pylori-secreted VacA and recombi-nant VacA were successfully separated and purified .The H.pylori-secreted VacA significantly induced the vacuolar change and apoptosis of AGS cells (P<0.01) while the recombinant VacA did not.Conclusion H.pylori-secreted VacA protein can effectively induce cell vacuolar change and apoptosis, but recombinant VacA can not, suggesting that the purified VacA protein secreted by H.pylori can be used to explore VacA-induced pathogenesis.

Differences in virulence markers between Helicobacter pylori strains from the Brazilian Amazon region

Introduction This study compares virulence markers of Helicobacter pylori isolated from patients in 2 cities in the Brazilian Amazon. Methods The study analyzed 168 patients with chronic gastritis from Belém and 151 from Bragança, State of Pará, Brazil. Levels of bacterial DNA associated with cagA and vacA alleles were checked by PCR, and hematoxylin-eosin staining was used for histologic diagnosis. Results In Bragança 87% of patients were genotype s1m1 cagA-positive (s1m1 cagA+), compared with 76% in Belém. In samples from patients in both cities, there was an association between s1m1 cagA+ strains and gastric mucosal damage. Conclusions Both cities have a high frequency of s1m1 cagA+ strains of H. pylori. .

In silico experiment with an-antigen-toll like receptor-5 agonist fusion construct for immunogenic application to Helicobacter pylori.

BACKGROUNDS: Helicobacter pylori colonize the gastric mucosa of half of the world's population. Although it is classified as a definitive type I carcinogen by World Health Organization, there is no effective vaccine against this bacterium. H. pylori evade the host immune response by avoiding toll-like detection, such as detection via toll-like receptor-5 (TLR-5). Thus, a chimeric construct consisting of selected epitopes from virulence factors that is incorporated into a TLR-5 ligand (Pseudomonas flagellin) could result in more potent innate and adaptive immune responses. MATERIALS AND METHODS: Based on the histocompatibility antigens of BALB/c mice, in silico techniques were used to select several fragments from H. pylori virulence factors with a high density of B- and T-cell epitopes. RESULTS: These segments consist of cytotoxin-associated geneA (residue 162-283), neutrophil activating protein (residue 30-135) and outer inflammatory protein A (residue 155-268). The secondary and tertiary structure of the chimeric constructs and other bioinformatics analyses such as stability, solubility, and antigenicity were performed. The chimeric construct containing antigenic segments of H. pylori proteins was fused with the D3 domain of Pseudomonas flagellin. This recombinant chimeric gene was optimized for expression in Escherichia coli. The in silico results showed that the conserved C- and N-terminal domains of flagellin and the antigenicity of selected fragments were retained. DISCUSSION: In silico analysis showed that Pseudomonas flagellin is a suitable platform for incorporation of an antigenic construct from H. pylori. This strategy may be an effective tool for the control of H. pylori and other persistent infections.

Therapeutic potential of snake venom in cancer therapy: current perspectives

Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer. Snake venom toxins contributed significantly to the treatment of many medical conditions. There are many published studies describing and elucidating the anti-cancer potential of snake venom. Cancer therapy is one of the main areas for the use of protein peptides and enzymes originating from animals of different species. Some of these proteins or peptides and enzymes from snake venom when isolated and evaluated may bind specifically to cancer cell membranes, affecting the migration and proliferation of these cells. Some of substances found in the snake venom present a great potential as anti-tumor agent. In this review, we presented the main results of recent years of research involving the active compounds of snake venom that have anticancer activity.

Therapeutic potential of snake venom in cancer therapy：current perspectives

Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer. Snake venom toxins contributed significantly to the treatment of many medical conditions. There are many published studies describing and elucidating the anti-cancer potential of snake venom. Cancer therapy is one of the main areas for the use of protein peptides and enzymes originating from animals of different species. Some of these proteins or peptides and enzymes from snake venom when isolated and evaluated may bind specifically to cancer cell membranes, affecting the migration and proliferation of these cells. Some of substances found in the snake venom present a great potential as anti-tumor agent. In this review, we presented the main results of recent years of research involving the active compounds of snake venom that have anticancer activity.

Influência da concentração de NaCl e pH na extração de ricina em torta de mamona (Ricinus communis L.) e sua caracterização por eletroforese / Influence of NaCl and pH concentration on the extraction of ricin in castor bean (Ricinus communis L.) and its characterization by electrophoresis

A mamoneira (Ricinus communis L.) é uma oleaginosa de alto valor econômico pelo fato de apresentar um mercado bem definido para o óleo extraído de suas sementes. A torta, que é um resíduo desta extração, se destaca pelo alto teor em proteínas. Dentre as proteínas encontradas na torta destaca-se a ricina, uma citotoxina, que inviabiliza sua utilização como fonte protéica alternativa para alimentação animal. O presente trabalho tem como objetivo identificar um melhor tratamento experimental para a extração de ricina da torta de mamona, visando futuros estudos de perda de integridade da ricina, o que garantiria a inocuidade do produto. Para tanto, buscou-se identificar a solução de maior capacidade de extração de proteínas, empregando a metodologia de superfície de resposta. Um delineamento composto central rotacional foi elaborado a fim de verificar o melhor pH e concentração de NaCl para a extração. Dos cinco diferentes valores de pH (4,0; 4,6; 6,0; 7,4; 8,0) e concentração de NaCl (0,0M; 0,3M; 1,0M; 1,7M; 2,0M) utilizados, o tratamento associando fosfato de potássio 0,2M/NaCl 1,7M pH 7,4 foi escolhido como o melhor. A concentração de proteína extraída neste tratamento chegou a valores quatro vezes maiores que o encontrado no de mínima extração de proteína. Pela evidenciação do gel de eletroforese não houve extração preferencial de ricina nos tratamentos testados, entretanto etapas de purificação usando diálise e precipitação com sulfato de amônio, permitiram uma evidenciação melhor das duas cadeias polipeptídicas de ricina.

Castor bean (Ricinus communis L.) is an oilseed crop of high economic value due to the fact of presenting a clearly defined market for the oil extracted from its seeds. Castor cake, which is a residue of oil extraction, is at the moment receiving special attention because of its high protein content. However, among the proteins found in this cake it is observed the presence of ricin, a cytotoxin, which turns this seed dangerous to be used as an alternative protein source for animal feed. The present research has the objective of identifying the best experimental treatment for extraction of ricin from castor cake, with the aim of future studies of loss of ricin integrity, which would ensure the safety of the product. With this aim, it was initiated the search for a buffer of higher capacity of proteins extraction, using the response surface methodology. A central composite design was developed in order to determine the best pH and NaCl concentration for extraction. Of the five different pH values (4.0, 4.6, 6.0, 7.4, 8.0) and NaCl (0.0M, 0.3M, 1.0M, 1.7M, 2.0M) used, the treatment containing 0.2M potassium phosphate / 1.7M NaCl pH 7.4 was chosen as the best. The amount of protein extracted in this treatment reached values four times larger than the minimum found in other treatment studied. The electrophoresis analysis showed that there was no preferential extraction of ricin in the treatments; however purification steps using dialysis and precipitation with ammonium sulfate led to a better resolution of the two polypeptide chains presents in ricin.