正己烷在分子筛上的裂化反应机理研究Ⅰ.正己烷的裂化反应链长

研究了正己烷在不同分子筛上的裂化反应 ,用裂化反应链机理的观点统一了正己烷裂化反应中的单、双分子两种反应机理 ,进一步明确了某些基元反应步骤的发生过程 ,较好地解释了正己烷裂化反应的产物分布以及产物选择性和分子筛孔径的关系。基于裂化反应链机理 ,提出了“裂化反应链长 (CCL )”的概念 ,并将裂化反应链长与分子筛的孔结构进行了关联。结果表明 ,在孔径较大的 Y,β等分子筛上 ,正己烷裂化反应有着较大的 CCL值 ,这意味着双分子的链传递反应在裂化链反应中占主要地位 ,有利于仅在链传递段中生成的异构烷烃的选择性 ;而在 ZSM-5 ,Ferrierite等小孔径的分子筛上 ,正己烷裂化反应的 CCL值较小 ,并接近 CCL 的理论极限值 2 ,这说明裂化反应主要由单分子的链引发和链终止反应来完成 ,其结果导致产物中烯烃选择性较高。与其它表征分子筛孔径或氢转移反应活性的参数相比 ,裂化反应链长既可用于表示氢转移、烷基转移等双分子反应在整个裂化反应中的比例 ,又和分子筛的孔结构有着良好的关联 ,因而 ,裂化反应链长 (CCL)是研究烷烃裂化反应机理以及关联裂化产物和分子筛孔结构性质的重要参数。

Bioleaching of Pb-Zn-Sn chalcopyrite concentrate in tank bioreactor and microbial community succession analysis

The variation of microbial community structure was investigated for the tank bioleaching process of Pb-Zn-Sn chalcopyrite concentrate in the presence of mixed moderately thermophilic bacteria. The parameters, such as pH value, solution potential and concentrations of metal ions, were determined by the method of polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） to analyze the succession of microbial community. The results showed that a final copper extraction rate of 85.6% could be obtained after tank bioleaching for 30 d. The Acidithiobacillus caldus was the dominant population with abundance of about 73.80%in the initial stage, then Sulfobacillus thermosulfidooxidans dominated from the 18th day to the end of bioleaching, while the abundance of Leptospirillum ferriphilum changed slightly. A higher solution potential within a certain range and appropriate concentration of ferric ions were essential for this tank bioleaching of chalcopyrite.

Studies on the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer

AIM To study the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer.

Knockdown of long non-coding RNA LCPAT1 inhibits autophagy in lung cancer

Objective: Long non-coding RNAs(lnc RNAs) are involved in numerous biological processes in lung cancer cells. In our previous studies, we identified a lnc RNA, ENST00000439577, which is highly expressed in lung carcinomas, and termed it lung cancer progression-associated transcript 1(LCPAT1). To characterize the role of LCPAT1 in lung cancer, we conducted the current study.Methods: Expression of LCPAT1 and autophagy-associated markers in tumor tissues and lung cancer cell lines was determined by real-time quantitative polymerase chain reaction(q PCR). Hematoxylin and eosin(HE) staining, q PCR, Western blot, and immunohistochemistry were performed to evaluate xenografted tumor tissues. Autophagy induced by rapamycin was detected by Western blot and immunofluorescence in lung cancer cell lines.Results: Expression of LCPAT1 and microtubule-associated protein 1 light chain 3 beta(LC3B) was positively correlated in lung cancer. Knockdown of LCPAT1 inhibited tumor growth and suppressed cell autophagy in vivo. Moreover, LCPAT1 knockdown in lung cancer cell lines resulted in decreased autophagy-associated gene expression and alleviated the cell autophagy induced by rapamycin.Conclusions: We speculate that LCPAT1 plays a crucial role in regulating autophagy in lung cancer.

Osteopontin expression is associated with hepatopathologic changes in Schistosoma japonicum infected mice

AIM:To investigate osteopontin expression and its association with hepatopathologic changes in BALB/C mice infected with Schistosoma japonicum.METHODS:The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria.Liver samples were obtained from mice sacrif iced at 6,8,10,14,and 18 wk after in-fection.Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining.The expression of osteopontin was determined with im-munohistochemistry,reverse transcription-polymerase chain reaction,and Western blotting.The expressionof α-smooth muscle actin(α-SMA)and transforming growth factor-β1(TGF-β1)were determined by im-munohistochemistry.Correlations of osteopontin ex-pression with other variables(α-SMA,TGF-β1,hepato-pathologic features including granuloma formation and degree of liver f ibrosis)were analyzed.RESULTS:Typical schistosomal hepatopathologic changes were induced in the animals.Dynamic changes in the expression of osteopontin were observed at week 6.The expression increased,peaked at week 10(P<0.01),and then gradually decreased.Positive correla-tions between osteopontin expression and α-SMA(r=0.720,P<0.01),TGF-β1(r=0.905,P <0.01),granu-loma formation(r=0.875,P<0.01),and degree of liver f ibrosis(r=0.858,P<0.01)were also observed.CONCLUSION:Osteopontin may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fi brosis through an un-explored mechanism.

Association between EGF +61A/G polymorphism and gastric cancer in Caucasians

AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian. RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021). CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.

Quaternary-ammonium-immobilized polystyrenes as efficient and reusable heterogeneous catalysts for synthesis of cyclic carbonate:Effects of linking chains and pendent hydroxyl group

Spherical polystyrene‐supported ammonium salts containing different linking chains between the support and ammonium groups were prepared as efficient and easily reusable heterogeneous catalysts for the cycloadditions of CO2and epoxides.The effects of the length of the linking chains and a hydroxyl group pendent on the linking chain on the catalytic performance of ionic liquid immobilized catalysts and their mechanisms were studied through experiments and density functional theory calculations.It was found that,compared with a short linking chain,a long chain can make the halogen anion more negative and provide a larger contact area of the catalysts with the reactants,thus enhancing the reaction kinetics.The hydroxyl group can stretch the C-O bonds of the epoxides,promoting the reaction thermodynamics.As a result,for the cycloaddition of propylene oxide,the yield of propylene carbonate is much higher for the catalyst with a long linking chain(yield:91.4%)compared with the yield for that with a short chain(yield:70.9%),and is further increased in the presence of pendent hydroxyl groups(yield:98.5%).The catalyst also shows a high catalytic activity even at mild temperature and good reusability(yield:≥96%for10cycles),and the selectivity is always above99%.

Ghrelin and gastrin in advanced gastric cancer before and after gastrectomy

AIM: To investigate plasma ghrelin, gastrin and growth hormone secretagogue receptor (GHS-R) expression in advanced gastric cancer (GC) before and after resection. METHODS: Seventy subjects in whom endoscopy of the upper gastrointestinal tract was performed in the Department of General Surgery at Cracow University during the past decade: (1) 25 patients with GC associated with Helicobacter pylori (H. pylori) infection; (2) 10 patients with GC 4-5 years after (total or subtotal) gastrectomy; (3) 25 healthy H. pylori-negative controls, matched by age and BMI to the above two groups; and (4) 10 GC patients 4-5 years after total gastrectomy. Ghrelin and gastrin plasma concentrations were measured by specific radioimmunoassay under fasting conditions and postprandially at 60 and 90 min after ingestion of a mixed meal. GHS-R expression was examined in biopsy samples from intact healthy mucosa and GC tissue using semi-quantitative reverse transcription-polymerase chain reaction. RESULTS: In healthy controls, fasting plasma ghrelin levels were significantly elevated and declined markedly at 60 and 90 min after a mixed meal. The concomitant enhanced ghrelin, GHS-R and gastrin expression in GC tissue over that recorded in intact mucosa, and the marked rise in plasma gastrin in these subjects under fasting conditions indicate the role of these hormonal factors in GC formation. Fasting plasma levels and postprandial response of ghrelin and gastrin appear to be inversely correlated in healthy subjects. Feeding in the controls resulted in a significant fall in plasma ghrelin with a subsequent rise in plasma gastrin, but in H. pylori-positive GC patients submitted to total or distal gastrectomy, feeding failed to affect significantly the fall in plasma ghrelin that was recorded in these patients before surgery. Fasting ghrelin concentrations were significantly lower in patients 4-5 years after total gastrectomy compared to those in healthy controls and to these in GC patients before surgery. CONCLUSION: Elevated plasma gastrin and suppression of fasting ghrelin in patients with GC suggest the existence of a close relationship between these two hormones in gastric carcinogenesis.

Cloning,characterization,and expression analysis of the DEAD-box family genes,Fc-vasa and Fc-PL10a,in Chinese shrimp (Fenneropenaeus chinensis)

RNA helicases of the DEAD-box and related families are involved in various cellular processes including DNA replication, DNA repair, and RNA processing. However, the function of DEAD-box proteins in aquaculture species is poorly understood at molecular level. We obtained the full-length cDNA sequences of two genes encoding helicase-related proteins, Fc-vasa and Fc-PL10a, from the testes of Chinese shrimp, Fenneropenaeus chinensis. The two predicted amino acid sequences contain all the conserved motifs characterized by the DEAD-box family and several RGG repeats in the N-terminal regions. Homology and phylogenetic analyses indicate that they belong to the vasa and PLIO subfamilies. The three-dimensional structures of the two proteins were predicted with a homology modeling approach. Both core proteins consist of two tandem RecA-like domains similar to those of the DEAD-box RNA helicase. Using reverse transcription-polymerase chain reaction （RT-PCR） and real-time PCR we found that Fc-vasa was expressed specifically in the adult gonads. Transcription decreased in the ovary but increased in the testis during gonadal development. Fc-PL10a expression was widely distributed in the tissues we examined. Using in situ hybridization, we demonstrated that the Fc-vasa transcript is localized to the cytoplasm of the spermatogonia and oocytes. Thus, our results suggest that Fc-wasa plays an important role in germ-line development, and has utility as a germ cell lineage marker which will help to generate new insight into the origin and differentiation of germ cells as well as the regulation of reproduction in F. chinensis.

Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

AIM:To investigate the role of transforming growth factor(TGF)-β-inducible early gene 1(TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma(HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium(MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line(MIHA),a TGF-β-sensitive hepatoma cell line(Hep3B) and two TGF-β-insensitive hepatoma cell lines(HepG2 and Bel7404) were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines(Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was signif icantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

Viral blips during long-term treatment with standard or double dose lamivudine in HBe antigen negative chronic hepatitis B

AIM:To evaluate safety and effect on hepatitis B virus(HBV)suppression of a long-term treatment with lamivudine(LAM)at standard(100 mg/d)or double(200 mg/d)dose in chronic hepatitis B.METHODS:This was a case study with matched controls(1:3)in patients with chronic hepatitis B with anti-HBe antibodies.RESULTS:Twelve patients received LAM 200 mg/d and 35 LAM 100 mg/d,for a median of 28 mo.A primary response(PR;i.e.negative HBV-DNA with Amplicor assay)was achieved in 100% of LAM-200 patients and 83% of LAM-100 patients.A virological breakthrough occurred in 16.7 and 24.7%,respectively,of the PR-patients,with the appearance of typical LAM resistance mutations in all but one patient.Viremia blips(i.e.transient HBV-DNA below 80 IU/mL in patients who tested negative at Amplicor assay)were detected using a real time polymerase chain reaction(PCR)and occurred in seven out of nine patients with subsequent BT and in four out of 32 patients with end-of-study response(77.7% vs 12.5%;P = 0.001)at chi-square test).At the end of the study,51.4% of LAM-100 patients and 83.3% of LAM-200 patients had remained stably HBV-DNA negative.Double-dose LAM was well tolerated.CONCLUSION:Long-term treatment of anti-HBe positive chronic hepatitis B with double dose lamivudine causes a more profound and stable viral suppression ascompared to conventional treatment.

Galactosylated chitosan/5-fluorouracil nanoparticles inhibit mouse hepatic cancer growth and its side effects

AIM： To observe the curative effect of galactosylated chitosan （GC）/5-fluorouracil （5-FU） nanoparticles in liver caner mice and its side effects. METHODS： The GC/5-FU nanoparticle is a nanomate- rial made by coupling GC and 5-FU. The release experiment was performed in vitro. The orthotropic liver cancer mouse models were established and divided into control, GC, 5-FU and GC/5-FU groups. Mice in the control and GC group received an intravenous injection of 200 μL saline and GC, respectively. Mice in the 5-FU and GC/5-FU groups received 200 μL （containing 0.371 mg 5-FU） 5-FU and GC/5-FU, respectively. The tumor weight and survival time were observed. The cell cycle and apoptosis in tumor tissues were monitored by flow cytometry. The expression of p53, Bax, Bcl-2, caspase-3 and poly adenosine 50-diphosphate-ribose polymerase 1 （PARP-1） was detected by immunohistochemistry, reverse transcription-polymerase chain reaction and Western blot. The serum blood biochemical parameters and cytotoxic activity of natural killer （NK） cell and cy- totoxicity T lymphocyte （CTL） were measured. RESULTS： The GC/5-FU nanoparticle is a sustained release system. The drug loading was 6.12% ± 1.36%, the encapsulation efficiency was 81.82% ± 5.32%, and the Zeta potential was 10.34 ± 1.43 mV. The tu- mor weight in the GC/5-FU group （0.4361±0.1153 g vs 1.5801 ± 0.2821 g, P 〈 0.001） and the 5-FU （0.7932±0.1283 g vs 1.5801 ±0.2821 g, P 〈 0.001） was sig- nificantly lower than that in the control group; GC/5- FU treatment can significantly lower the tumor weight （0.4361± 0.1153 g vs 0.7932±0.1283 g, P 〈 0.001）, and the longest median survival time was seen in the GC/5-FU group, compared with the control （12 d vs 30 d, P 〈 0.001）, GC （13 d vs 30 d, P 〈 0.001） and 5-FU groups （17 d vs 30 d, P 〈 0.001）. Flow cytom- etry revealed that compared with the control, GC/5- FU caused a higher rate of G0-G1 arrest （52.79% ± 13.42% vs 23.92%±9.09%, P = 0.014 ） and apopto- sis （2.55% ±1.10% vs 11.13% ±11.73%, P 〈 0.001） in hepatic cancer cells. Analysis of the apoptosis path- ways showed that GC/5-FU upregulated the expression of p53 at both the protein and the mRNA levels, which in turn lowered the ratio of Bcl-2lBax expression; this led to the release of cytochrome C into the cytosol from the mitochondria and the subsequent activation of caspase-3. Upregulation of caspase-3 expression de- creased the PARP-1 at both the mRNA and the protein levels, which contributed to apoptosis. 5-FU increased the levels of aspartate aminotransferase and alanine aminotransferase, and decreased the numbers of platelet, white blood cell and lymphocyte and cytotoxic activities of CTL and NK cells, however, there were no such side effects in the GC/5-FU group. CONCLUSION： GC/5-FU nanoparticles can significant- ly inhibit the growth of liver cancer in mice via the p53 apoptosis pathway, and relieve the side effects and im- munosuppression of 5-FU.

YKL40 expression in CD14^+ liver cells in acute and chronic injury

AIM:To demonstrate that CD14 + cells are an important source of the growth factor YKL40 in acute and chronic liver damage.METHODS:Rats were inoculated with one dose of CCl4 to induce acute damage.Liver biopsies were obtained at 0,6,12,24,48 and 72 h.For chronic damage,CCl4 was administered three days per week for 6 or 8 wk.Tissue samples were collected,and cellular populations were isolated by liver digestion and purified by cell sorting.YKL40 mRNA and protein expression were evaluated by realtime polymerase chain reaction and western blot.RESULTS:Acute liver damage induced a rapid increase of YKL40 mRNA beginning at 12 h.Expression peaked at 24 h,with a 26fold increase over basal levels.By 72 h however,YKL40 expression levels had nearly returned to control levels.On the other hand,chronic damage induced a sustained increase in YKL40 expression,with 7and 9fold higher levels at 6 and 8 wk,respectively.The pattern of YKL40 expression in different subpopulations showed that CD14+cells,which include Kupffer cells,are a source of YKL40 after acute damage at 72 h[0.09 relative expression units(REU)]as well as after chronic injury at 6 wk(0.11 REU).Hepatocytes,in turn,accounted for 0.06 and 0.01 REU after 72 h(acute)or 6 wk(chronic),respectively.The rest of the CD14cells(including T lymphocytes,B lymphocytes,natural killer and natural killer T cells) yielded 0.07 and 0.15 REU at 72 h and 6 wk,respectively.YKL40 protein expression in liver was detected at 72 h as well as 6 and 8 wk,with the highest expression relative to controls(11fold;P≤0.05)seen at 6 wk.Macrophages were stimulated by lipopolysaccharide.We demonstrate that under these conditions,these cells showed maximum expression of YKL40 at 12 h,with P<0.05 compared with controls.CONCLUSION:Hepatic CD14 + cells are an YKL40 mRNA and protein source in acute and chronic liver injury,with expression patterns similar to growth factors implicated in inflammationfibrogenesis.

Surface Acidity of Aluminum Phosphate and Its Catalytic Performance in Benzene Alkylation with Long Chain Olefin

The acidic properties of aluminum phosphate （A1PO4-5） solid acid catalyst were characterized by tem- perature programmed desorption （TPD） of ammonia （NH3）, n-propylamine （n-C3HTNH2）, iso-propylamine [（CH3）2CHNH2] and n-dipropylamine [（C3H7）2NH] separately, and its catalytic performance in benzene alkylation with long chain olefin was studied in a fixed-bed reactor. The characterized acid amount of catalyst increased with the basicity of adsorbates. With increase of the activation temperature of catalyst, the acid amount characterized by NHa-TPD decreased, however, it increased when characterized by TPD using three other adsorbates. The desorption kinetics of TPD process and the deactivation kinetics of catalyst were investigated. The acidity and catalytic per- formance of catalyst was also correlated. The results showed that the acid amount and strength are well correlated with the activity and stability using NH3 as adsorbate, respectively, which indicated NH3 was a better basic adsorbate. It was also found that the catalyst with higher acid amount and lower acid strength on the surface exhibited the better catalytic performance and stability.

Connective tissue growth factor reacts as an IL-6/STAT3-regulated hepatic negative acute phase protein

AIM:To investigate the mechanisms involved in a possible modulator role of interleukin(IL) -6 signalling on CYR61-CTGF-NOV(CCN) 2/connective tissue growth factor(CTGF) expression in hepatocytes(PC) and to look for a relation between serum concentrations of these two parameters in patients with acute inflammation. METHODS:Expression of CCN2/CTGF,p-STAT3,p-Smad 3/1 and p-Smad2 was examined in primary freshly isolated rat or cryo-preserved human PC exposed to various stimuli by Western blotting,electrophoretic mobility shift assay(EMSA) ,reporter-gene-assays and reversetranscriptase polymerase chain reaction. RESULTS:IL-6 strongly down-regulated CCN2/CTGF protein and mRNA expression in PC,enhanceable by extracellular presence of the soluble IL-6 receptor gp80,and supported by an inverse relation between IL-6 and CCN2/CTGF concentrations in patients'sera.The inhi-bition of TGFβ1 driven CCN2/CTGF expression by IL-6 did not involve a modulation of Smad2(and Smad1/3) signalling.However,the STAT3 SH2 domain binding peptide,a selective inhibitor of STAT3 DNA binding activity,counteracted the inhibitory effect of IL-6 on CCN2/CTGF expression much more pronounced than pyrrolidine-dithiocarbamate,an inhibitor primarily of STAT3 phosphorylation.An EMSA confirmed STAT3 binding to the proposed proximal STAT binding site in the CCN2/CTGF promoter. CONCLUSION:CCN2/CTGF is identified as a hepatocellular negative acute phase protein which is downregulated by IL-6 via the STAT3 pathway through interaction on the DNA binding level.

Effect of low-dose X-ray radiation on adaptive response in gastric cancer cell

Objective： We aimed to study the effect and mechanism of low-dose radiation （LDR） on adaptive response of gastric cancer cell. Methods： SGC7901 cells were cultured in vitro, and divided into 4 groups： control group （DO group）, low-dose radiation group （D1 group, 75 mGy）, high-dose radiation group （D2 group, 2 Gy）, low-dose plus high-dose radiation group （D1 ＋ D2 group, 75 mGy ＋ 2 Gy, the interval of low and high-close radiation being 8 h）. Cell inhibition rate was detected by cytometry and CCK8 method; the proportion of cell cycle at different times after irradiation was determined by using a flow cytometry. The ATM mRNA levels were detected by using quantitative real-time reverse transcription polymerase chain reaction （RT-PCR）. Results： There was no significant different between groups DO and D1, groups D2 and D1 ＋ D2 cell inhibition rate （P 〉 0.05）. There was a significant increase G2/M arrest in groups D2 and D1 ＋ D2 than groups DO and D1 after 6 h of radiation and did not recover at 48 h （P 〈 0.05）. The ATM mRNA expression of group D2 and D1 ＋ D2 increased highly than that of group DO and D1 （P 〈 0.05）. However, differences between group D2 and D1 ＋ D2, group DO and D1 were not statistical significant （P 〉 0.05）. Conclusion： LDR cannot induce adaptive response in SGC7901 cells in vitro, which may be associated the regulation of cell cycle, and its ATM mRNA expression cannot be affected by 75 mGy X-ray radiation.

Genotype identification of Orientia tsutsugamushi isolated from Nan Peng Lie Islands in China

OBJECTIVE: To identify genotype of eight strains of Orientia tsutsugamushi (O. tsutsugamushi) isolated from Nan Peng Lie Islands in China and establish tsutsugamushi disease nature foci for this region. METHODS: The nested polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used. Three primers were selected from the DNA sequence of the gene encoding type-specific 56-kDa protein of the Karp strain. The positive products were digested by Hine II and Pst I, meanwhile profiles specific to each strain were analyzed. RESULTS: Three genotypes of O. tsutsugamushi including Karp, Kato and a new strain existed on Nan Peng Lie Islands. CONCLUSION: Nan Peng Lie Islands is tsutsugamushi disease nature foci.

Relationship of large multifunctional proteasome 7 gene polymorphism with susceptibility to type 1 diabetes mellitus and DR3 gene

Objective To study the relationship of the large multifunctional proteasome 7 (LMP7) gene polymorphism with susceptibility to type 1 diabetes mellitus (DM-1) and the DR3 gene in south Chinese Han population.Methods LMP7 genotypes and the DR3 gene were identified in 71 DM-1 patients and 86 healthy persons (as controls) by polymerase chain reaction-restriction fragment length polymorphism. DM-1 patients and controls were divided into DR3-positive and DR3-negative subjects. The frequencies of LMP7 genotypes and alleles were compared between DM-1 patients and controls respectively in the random subjects and in the DR3-matched subjects. Furthermore, DM-1 patients were divided into 3 groups according to the age of diabetic onset: group A≤14 years, group B 15-30 years, group C≥31 years.Results In the random subjects, the frequency of LMP7-B/B was lower (39% vs 58%, P<0.05) and that of LMP7-B/A was higher (54% vs 31%, P<0.01) in DM-1 patients than that in controls. In DR3-positive subjects, the frequencies of LMP7 genotypes and alleles showed no differences between DM-1 patients and controls. In DR3-negative subjects, the frequency of LMP7-B/B was decreased (40% vs 61%) and that of LMP7-B/A was increased (55% vs 28%, P<0.01) in DM-1 patients. The frequencies of LMP7 genotypes and alleles showed no significant differences among different ages of diabetic onset.Conclusions LMP7-B/B may be the protective genotype, and LMP7-B/A may be the susceptible genotype of DM-1, and this may not be affected by the DR3 gene. Persons with LMP7-B/B may have a decreased risk, and those with LMP7-B/A have an increased risk suffering from DM-1. The LMP7 gene may not be associated with the age of diabetic onset.