Octaprenyl pyrophosphate synthase (OPPs), an enzyme belonging to the trans-prenyltransferases family, is involved in the synthesis of C40 octaprenyl pyrophosphate (OPP) by reacting farnesyl pyrophosphate (FPP) with five isopentenyl pyrophosphates (IPP). It has been reported that OPPs is essential for bacteria's normal growth and is a potential target for novel antibacterial drug design. Here we report the crystal structure of OPPs from Helicobacter pylori, determined by MAD method at 2.8 Å resolution and refined to 2.0 Å resolution. The substrate IPP was docked into HpOPPs structure and residues involved in IPP recognition were identified. The other substrate FPP, the intermediate GGPP and a nitrogen-containing bisphosphonate drug were also modeled into the structure. The resulting model shed some lights on the enzymatic mechanism, including (1) residues Arg87, Lys36 and Arg39 are essential for IPP binding; (2) residues Lys162, Lys224 and Gln197 are involved in FPP binding; (3) the second DDXXD motif may involve in FPP binding by Mg(2+) mediated interactions; (4) Leu127 is probably involved in product chain length determination in HpOPPs and (5) the intermediate products such as GGPP need a rearrange to occupy the binding site of FPP and then IPP is reloaded. Our results also indicate that the nitrogen-containing bisphosphonate drugs are potential inhibitors of FPPs and other trans-prenyltransferases aiming at blocking the binding of FPP.

Helicobacter pylori can efficiently capture iron either from free heme or heme-containing compounds in the iron-limited gastric mucosa. However, the heme iron utilization systems of H. pylori have not been fully described to date. To investigate the contribution of genes involved in heme–iron utilization, a gene homologous to frpB , encode by hp0876 in H. pylori ATCC 26695, was inactivated by homologous recombination. Δhp0876 showed no demonstrable growth defects in the presence of the various concentrations of free iron. Moreover, when hemoglobin or heme was supplied as the sole iron sources, Δhp0876 had growth curves similar to the wild-type strain. The growth competition experiments in vitro also showed that Δhp0876 retained the ability for iron acquisition. Furthermore, IL-8 production in human gastric epithelial cells co-cultured with Δhp0876 and wild-type strain was compared, and our results indicated that lack of HP0876 affected the IL-8 release. And Δhp0876 exhibited significantly increased adherence to gastric epithelial cells. Together, our data suggests that HP0876 is dispensable for H. pylori heme–iron uptake, but it may attenuate H. pylori adherence to gastric epithelial cells, which induced decreased production of H. pylori -induced IL-8 production in gastric epithelial cells.

ABSTRACT The infection rate of Helicobacter pylori is high all over the world, especially in the Chinese Tibetan Plateau. Here, we report the genome sequence of Helicobacter pylori strain XZ274 isolated from a Tibetan patient with gastric cancer. The strain contains 1,634,138 bp with 1,654 coding sequences and a pXZ274 plasmid of 22,406 bp with 26 coding sequences. This is the first complete genome sequence of Helicobacter pylori from the Tibetan Plateau in China.

BACKGROUND:Colonization of individual hosts by multiple Helicobacter pylori genotypes may be one reason why this infection is persistent and difficult to eradicate.METHODS:In order to study the diversity of H. pylori in individuals, a modified randomly amplified polymorphic DNA (RAPD) method was applied using primary culture isolates instead of passaged cultures.RESULTS:The results showed that variations in H. pylori were prevalent among individuals in the Chinese population, and the incidence of multiple colonization was 99.1% (115/116), significantly higher than in other reports. Moreover, the number of RAPD genotypes was found to be significantly associated with the process of disease development (p<0.05). Indeed, a trend for a higher number of RAPD genotypes within a single host (up to five genotypes) was observed as the disease developed or became more serious. After subculturing for three generations in our experiment, some genotypes present in the primary cultures were lost. The different genotypes in one patient may have originated from a single ancestral strain, as determined by analysis of six H. pylori housekeeping gene alleles, most of which were shown to be identical.CONCLUSIONS:These results suggest that investigating isolates of the primary culture will better reflect the H. pylori diversity in individuals. Also, they indicate that continuous variation of one strain in the gastric microenvironment may be the main cause of H. pylori diversity in individuals in the Chinese population.

Th17 cells represent a novel subset of CD4(+) T cells, which is associated with chronic inflammation. The present study evaluated Th17 cell responses to Helicobacter pylori infection in mouse model and CD4(+) T cell differentiation in response to H. pylori-infected macrophages. Th17 cells were observed in the H. pylori-infected gastric tissue. Co-culture of CD4(+) T cells with H. pylori-infected macrophages elevated IL-17 and IFN-γ secretion, up-regulated retinoid-related orphan receptor gamma t (RORγt) and T box expressed in T cells (T-bet) expression and increased the numbers of Th17 and Th1 cells. The expression of CD40, CD80, and CD86 and the secretion of IL-6, TGF-β1, IL-23, and CCL20 were significantly increased in H. pylori-stimulated macrophages. NF-κB pathway participated in the production of IL-6, IL-23, and CCL20 from macrophages in response to H. pylori, and inhibition of NF-κB pathway of macrophages resulted in less Th17 cell differentiation. Taken together, these results suggest that H. pylori induces Th17 cell differentiation via infected macrophages.

Background: H. pylori (Helicobacter pylori) is the major causative agent of chronic active gastritis. The population of H. pylori shows a high genomic variability among isolates. And the polymorphism of repeat-units of genomics had participated the important process of evolution. Its long term colonization of the stomach caused different clinical outcomes, which may relate to the high degree of genetic variation of H. pylori. A variety of molecular typing tools have been developed to access genetic relatedness in H. pylori isolates. However, there is still no standard genotyping system of this bacterium. The MLVA (Multi-locus of variable number of tandem repeat analysis) method is useful for performing phylogenetic analysis and is widely used in bacteria genotyping; however, there's little application in H. pylori analysis. This article is the first application of the MLVA method to investigate H. pylori from different districts and ethnic groups of China.Results: MLVA of 12 VNTR loci with high discrimination power based on 30 candidates were performed on a collection of 202 strains of H. pylori which originated from five regions of China and Japan. Phylogenetic tree was constructed using MLVA profiles. 12 VNTR loci presented with high various polymorphisms, and the results demonstrated very close relationships between genotypes and ethnic groups.Conclusions: This study used MLVA methodology providing a new perspective on the ethnic groups and distribution characteristics of H. pylori.

Mutants of pertussis toxin (PT) S1 subunit and filamentous hemagglutinin (FHA) type I immunodominant domain from Bordetella pertussis (B. pertussis) are considered to be effective candidate antigens for acellular pertussis vaccines; however, the substantial progress is hampered in part for the lack of a suitable in vitro expression system. In this paper, the gene sequences of a S1 mutant C180-R9K/E129G (mS1) and a truncated peptide named Fs from FHA type I immunodominant domain were linked together and constructed to pET22b expression vector as a fusion gene; after inducing with IPTG, it was highly expressed in E. coli BL21 (DE3) as inclusion body. The fusion protein FsmS1 was purified from cell lysates and refolded successfully. The result of Western blotting indicate that it was able to react with both anti-S1 and anti-FHA McAbs; antiserum produced from New Zealand white rabbits immunized with this protein was able to recognize both native PT and FHA antigens as determined by western blotting. These data have provided a novel feasible method to produce PT S1 subunit and FHA type I immunodominant domain in large scale in vitro, which is implicated for the development of multivalent subunit vaccines candidate against B. pertussis infection.

The haem oxygenase HugZ is part of the iron-acquisition mechanism that is essential for the adaptive colonization of Helicobacter pylori, a major pathogen of gastroenteric diseases. The HugZ-haemin complex has been purified and crystallized and diffraction data sets have been collected to 1.8 A resolution. The HugZ-haemin complex crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 88.40, b = 139.37, c = 152.97 A.

Helicobacter pylori infection is a risk factor for development of peptic ulcers, and psychological stress (PS) may have a role in the pathogenesis of this condition. However, no interaction between PS and H. pylori infection (HI) has been established in the development of peptic ulcer, because colonization by H. pylori is the first step in the infection of the gastric mucosa, we examined H. pylori colonization of the stomach in BALB/c mice after PS. The mice were subjected to PS in a communication box test, in which they observed other mice experiencing a physical stressor (electrical) before they were inoculated with H. pylori. We found that the H. pylori colonization in the stomach of psychologically stressed mice was significantly greater than in the control mice (P < 0.05), and histological examination showed that the gastric mucosal injury in the stressed mice was more extensive than in the control mice (P < 0.05). To explore the underlying mechanisms, we administered RU486 (a type II glucocorticoid (GC) receptor antagonist) to antagonize the effect of endogenous corticosterone: this treatment decreased colonization by H. pylori in the psychologically stressed mice. We conclude that HI of the stomach of BALB/c mice is enhanced by PS, and the effect may be mediated by GCs.

Small noncoding RNAs (sRNAs) are a group of regulatory RNA molecules normally without a protein-coding function. In recent years, the importance of sRNAs as mediators of gene expression in bacteria has begun to be recognized. More than 70 sRNAs have been known in Escherichia coli. However, little is known about sRNAs in Helicobacter pylori, a human pathogen associated with gastric diseases. Here, we systematically identified sRNAs in the H. pylori genome by a computational approach based on gene location, sequence conservation, promoter and terminator search, and secondary structure. Among a total of six candidate sRNAs initially predicted, two novel sRNAs (IG-443 and IG-524) were confirmed by Northern blot and reverse transcription–polymerase chain reaction (RT-PCR). Virtually, they were a class of natural antisense transcripts, which were complementary to partial sequences of the following genes: flagellar motor switch gene (fliM) and fumarase (fumC). Taken together, the results indicate that there exist novel sRNAs in H. pylori and these RNAs might play a potential role in regulating gene expression.

AIM: To test the reliability and validity of Cattell 16 personality factor questionnaire (16PF) in military personnel, and to make a national norm, and to analyze the developmental characteristics of military personnel in gender, service years and military rank. METHODS: 16PF was employed to evaluate 13450 military personnel in 30 provinces or cities of China. The data were compared in gender, service years and military rank. RESULTS: ① Item analysis: The correlation coefficients between each item score and the total score were in 0.410-0.691 (P0.01). ② Reliability and validity analysis: The Cronbach alpha was in 0.511-0.829, the split-half reliabilities were in 0.541-0.838, and the repeated reliabilities were 0.553-0.842. The correlation coefficients between total score and factor scores were 0.612-0.845, and the correlation coefficients among most factor scores were 0.180-0.510. ③ National norm of 16PF of military personnel was successfully made. ④ Developmental characteristics analysis: Compared with the female, the scores of the male increased obviously in factor A, C, E, G, L, M, N, O, Q4, X1 and Y2, and the scores decreased obviously in factor B, F, H, Q1, Q2, X4, Y1 and Y3(P0.05) other than factor I, Q3, X2, X3 and Y4(P0.05); there were obvious differences in factor scores among service years other than factor E, G and X2 (P0.05). Clear difference was found in factor scores other than factor E, L, M and Y2 of 16PF among soldiers, petty officers and officers (P0.05). CONCLUSION: 16PF in military personnel shows well differentiation, reliability and validity, and there are obvious developmental characteristics in gender, service year and military rank in personality of military personnel by 16PF.

AIM: To investigate the changes of cognitive function of soldiers trained in high altitude areas. METHODS: Cognitive ability test (number discrimination test, continuous calculation test and symbol cognition test ) was employed to continuously evaluate 50 training soldiers in high altitude areas. RESULTS: ①Significant difference was found in the cognitive task rate of soldiers in areas of different altitudes(P0.05). ②Except for number discrimination test, significant difference was found in the cognitive task rate of soldiers sent to the high altitude areas at different times(P0.01). ③Significant difference was found in the cognitive task rate of soldiers undergoing military training of different phases(P0.01). ④ Significant differences were found in the cognitive accuracy rate of soldiers who were stationed at areas of different altitudes, sent to the high altitude areas at different times and undergoing military training of different phases(P0.01). CONCLUSION: High altitude plays an important role in the cognitive function of soldiers under training. Its effect is related to the altitude of the area, the time of being sent to high altitude areas and the phase of military training.

OBJECTIVE To study the clinical and histological features of chronic hepatitis B (CHB) with negative hepatitis B e-antigen (HBeAg). METHODS A total of 743 in-patients with chronic hepatitis B were recruited into the study and divided into two groups according to the HBeAg status. The correlation among alanine transaminase (ALT) levels, hepatitis B virus (HBV) DNA semiquantification, and the liver histopathological data were detected. RESULTS Of the 743 successive in-patients, 267 (35.9%) were HBeAg-negative. The HBDAG-negative group had significantly lower serologic HBV DNA levels (63.0% of < 100 pg/ml) vs HBeAg-positive (42.6%, P < 0.001), while more sever inflammation (58.1% of inflammatory scores of histological activity index (HAIinf > or = 9) vs HBeAg-positive group (46.0%, P < 0.001) and severe fibrosis (45.3% of fibrosis scores of histological activity index (HAIfib > or = 3) vs HBeAg-positive group (27.9%, P < 0.001) of liver histology. In HBeAg-positive patients, increasing ALI levels were significantly associated with high inflammation and fibrosis scores and low HBV DNA levels. However, it was not the case in the HBeAg-negative cases. In HBeAg-positive patients, 91.3% of them had HAIinf > or = 9 and 65.7% had HAIfib > or = 3 with HBV DNA > 100 pg/ml, while 8.2% of them had HAIinf > or = 9 and 12.3% had HAIfib > or = 3 with HBV DNA < 20 pg/ml, indicating an obverse correlation between HBV DNA levels and histology scores. CONCLUSIONS As regards clinical and histological background, the chronic HBeAg-negative hepatitis B is a different subpopulation from the HBeAg-positive counterpart.

Leishmaniasis is a chronic parasitic disease of the reticuloendothelial system, manifested by gradual onset, unspecific disorders and may take the form of visceral, cutaneous or mucocutaneous leishmaniasis.

　　患者男性，27岁。生于陕西渭南，居住于山西，经常来往于山西与陕西渭南。不明原因发热2个月余，伴有肝脾肿大。曾在两家大医院做了详细的检查，未查出原因。用多种抗生素治疗无效。怀疑肠结核，做诊断性抗结核治疗2周，无明显的疗效。于1999年12月2日以不明原因的发热（FUO）入住我院。 　　入院时体温39℃，浅表淋巴结均未触及。肺肝界于右锁骨中线第4肋间。腹稍膨隆，肝肋下5 cm，剑下7 cm，质软，无压痛。脾肋下3 cm。移动性浊音阴性。 　　实验室检查：血常规WBC （1.4～3.2）×109/L, RBC （2.0～2.4）×1012/L, Hb 48～70g/L, 血小板（100～166）×109/L。 尿、粪常规 (-)。 转氨酶轻度升高（ ALT40～99 U/L, AST 40～184 U/L）, 白蛋白明显降低（ 21.0～35.0 g/L）。肾功正常。甲、乙、丙、丁、戊、庚型肝炎抗体均为 (-)。 蛋白电泳示白蛋白降低（0.384～0.390）， γ-球蛋白明显升高（0.46～0.48，正常值为0.14～0.20)。免疫球蛋白IgG显著升高（28.5～40.2g/L，正常值为7.6～16.6 g/L), IgA、 IgM、 IgE正常。 血沉80～101 mm/1h。抗“O”、类风湿因子（-）。自身抗体多次检查（-）。血、尿、粪、胆汁、骨髓培养（-）。骨髓片多次示感染骨髓象， 缺铁伴营养性贫血。 肥达、外斐反应（-）。冷凝集实验、布氏杆菌凝集实验（-）。 结核菌素试验（-），TB-DNA（-）。病毒系列：EB病毒、腺病毒、风疹病毒、巨细胞病毒IgM均 (-)，抗-HIV（-）。 C-反应蛋白7.75 mg/L。T细胞亚群正常。胸片示右膈肌抬高, 胸腔少量积液。超声示少量心包积液。腹部B超示肝大，脾大，少量腹水。腹部CT：肝大，肝脏CT值均匀降低, 提示脂肪肝。肝活检3次示肝组织大片凝固性坏死。

OBJECTIVE To detect hepatitis B virus core promoter (CP) mutations in patients with fulminant hepatitis. METHODS Polymerase chain reaction amplified serum HBV DNA fragments were directly sequenced. RESULTS There were 2-12 nucleotide substitutions in CP region in the 7 subacute fulminant hepatitis patients studied. An 11 bp nucleotides insertion was found in one patient. Mutations in CP were usually seen in the first and the second A T rich regions. The A to T mutation at nt 1,762 and G to A mutation at nt 1,764 were found in 4 cases, 3 of them were HBeAg negative. The third A T rich region was kept intact in all the 7 patients, so did the initial site of HBV replication (DR1) and the initial site of mRNA transcription (1,783/1784 or 1,790 +/- 1 for precore mRNA and 1818 for pregenome-C/P mRNA). CONCLUSION CP mutations in patients with fulminant hepatitis are common, most of the CP variations occur in the first and the second A T rich regions, and these mutations may impede the transcription of precore mRNA and affect the expression of HBeAg.