The plague occurs due to the long-term persistence of Yersinia pestis in natural environment.During the period of plague epidemic and quiescence,there are still some unknown scientific questions,such as where Yersinia pestis preserved,which mode preserved,and which mechanism caused plague epidemic.Thus,the researches on the preservation and viability of Yersinia pestis in every ecological element of plague natural foci will contribute to find the pattern for the occurrence and spread of plague.

Objective:To investigate effects of miR-503 on cisplatin sensitivity in BEL-7402 cells by targeting of bcl-2.Methods:MiR-503 and bcl-2 mRNA expression levels in hepatocellular carcinoma cells were measured by real-time quantitative (qRT)-PCR;Bcl-protein level was detected by Western blot;miR-503 mimics were transiently transfected to the BEL-7402 cells by liposome transfection;potential target genes of miR-503 were predicted by Bioinformatics software;miR-503 potential targets were validated by dual luciferase activity;and the cell viability was measured by MTT assay.Results:MiR-503 level was down-regulated and Bcl-2 protein expression level was up-regulated in BEL-7402 cells compared with HL-7702 cells.MiR-503 could interact with bcl-2 and inhibit its expression.Cell vitality with miR-503 transfection was significantly reduced compared to that in the negative control.Conclusion:MiR-503 may enhance the sensitivity of BEL-7402 cells to cisplatin and inhibit the cell proliferation by targeting bcl-2.

Objective To analyze nucleic acid sequence homology of the 6 kb(pYC) plasmid of Yersina. pestis (Y. pestis) isolated from Yurman by searching GenBank. Method The search of sequence similarity was accomplished with BLAST. Results The pYC plasmid sequence had high homology with some genes in nueleotide sequence, such as: 97.1% homology with Shigella sonnei pKYM, 92.1% homology with Haemophilus influenzae(H. influenzae) gene, Salmonella typhi (S. typhi) gene LT2 and plMVSI with 88.2% and 87.2% of homology respectively, Escherichia coli(E, coli) O157:H7 and K-12, ECOR31 with 81.4%, 81.4% and 84.7% of homology respectively. This plasmid ORFs could code for some proteins which were similar with others in GenBank, such as: ORFi and H. paragallinarum replication protein B(47.2%), ORF4 and E. coli hypothetical protein(52.7%), ORF5 and Y. pseudotuberculosis Tile (48.3%), ORF6 and E. coil Pilx5/VirB5-1ike protein (42.3%), Y. enterocolitica TriD protein(38.5%), ORFIO and S. typhimurium LT2, E. coli O157:H7 hypothetical protein(83.1% and 81.9%, respectively), ORF11 and E. coli, damage-inducible protein J(81.4%). Conclusions The pYC plasmid sequence has high homology with a few bacterial genes of Enterobacteriaceac. This plasmid may code for some proteins that are similar with hypothetical protein, damnge-indncible protein, TriD and TilE protein, Pilx5/VirB5-hke protein of Escherichia or Yersinia.

Objective To evaluate the risk of plague occurrence via surveying and analyzing indoor rat density and flea index in natural villages having previous plague experience. Methods During August to September 2007, 30 natural villages experiencing previous plague were selected based on the surveillance data, and then all households were coded with numbers and 20 households in each village were randomly selected via computer. Cages and sticky papers were set in 600 selected households to capture rats and fleas. Rat density, flea prevalence, flea index and median were estimated. Results One hundred thirty-three Rattus flavipectus and 33 Suncus murinus were caught and averaged rat density was 2.8 rats per one hundred cage. nights (166/6000), the median was 5 rats each village. One hundred and one mice infected fleas, flea prevalence on rats was 60.8% (101/166), 296 Xenopsylla cheopis and 48 Leptopsylla segnis were collected. Rat flea index was 2.1 fleas per rat (344/166). A total of 315 dissociated flea was caught, average dissociated flea index was 0.026 fleas per sticky paper (315/11888). The median was 5.5 dissociated fleas per village. Of dissociated fleas, Ctenocephalides felis felis (205) and Xenopsylla cheopis (103) accounted for 97.8% (308/315). The proportion for species of the rat flea and the dissociated flea was different(Fisher test: P < 0.01). The rat flea was significantly associated with the rat density(r = 0.68, P < 0.01), but the dissociated flea was significantly associated with neither the rat density(r = -yield than fried wheat batter(χ2 = 5.59, P < 0.05). Conclusions In these villages having previous plague experience of Lianghe County, Rattusflavipectus was dominant species of indoor rats, Xenopsylla cheopis and Ctenocephalides felis felis were dominant species of rat flea and dissociated flea, respectively. Mengsong, Bangdu, and Tangjiatun village had potential risk of plague emergence.

Animals ; Cytochrome P-450 CYP1A2 ; Cytochrome P-450 CYP2C19 ; metabolism ; Cytochrome P-450 Enzyme System ; metabolism ; Cytochromes ; metabolism ; Liver Cirrhosis ; enzymology ; Rats

Objective To study on the effects of Huaweishu granule on cisplatin-induced Beagle dog vomiting models and its mechanism.Methods Cisplatin-induced Beagle dog vomiting models were adopted as research object.The changes of vomiting frequency,latency,serum motilin content in the medulla oblongata and ileum,5-HT and substance P content of these models after using Hua weishu Granule were observed.Results ① Latent period of vomiting of the model group was (60.8±37.1)min; while this period was (137.3± 53.4)min,(122.8 ± 50.7) min,(l16.8±44.6)min,in the Huawei-shu low,medium and high dose group respectively,all showing a statistic difference than the model group (P＜0.05).②Frequency of vomiting in the model group was (270.3±51.8),while this frequence was (111.5±45.0) and (149.5±26.8) in Huawei-shu low and medium dose group respectively; ③ serum motilin in the model group was (0.354±0.098)ng/ml,while serum motilin in Huawei-shu low,medium and high dose group was (0.230±0.074) ng/ml,(0.235± 0.071) ng/ml,and (0.245± 0.062)ng/ml respectively,all lower than the model group (P＜ 0.05).④ Medulla oblongata 5-HT in the model group was (2.028 ±0.198)ng/ml,while medulla oblongata 5-HT in Huawei-shu low,medium and high dose group was (1.620±0.329)ng/ml,(1.194±0.386)ng/ml,and (1.269 ± 0.251) ng/ml respectively,all were lower than the model group (P＜0.05); ileum 5-HT in the model group was (1.634± 0.221)ng/ml,while ileum 5-HT in Huawei-shu low,medium and high dose group was (1.108±0.291)ng/ml,(1.194±0.386)ng/ml,and (1.269 ± 0.251) ng/ml respectively,all were lower than the model group(P＜0.05) ;⑤ ileal substance P content of the model group was (0.356±0.063)ng/ml,while ildeal P content in Huawei-shu low dose group was (0.274±0.064)ng/ml,lower than the model group than(P＜0.05).The medullary substance P content was (0.432±0.021)ng/ml in the model group,while medullary P content in Huawei-shu low,medium and high dose group was (0.370±0.040) ng/ml,(0.385±0.029) ng/ml,and (0.386± 0.041)ng/ml respectively,all were lower than the model group(P＜0.05).Conclusion Huawei-shu granule can prevent cisplatin-induced Beagle vomiting.

OBJECTIVETo investigate the characteristics of human caliciviruses (HuCV) diarrhea among infants and young children with acute diarrhea in Lanzhou, Gansu Province, China by using molecular epidemiologic techniques.

METHODSStool specimens were collected from both outpatients and inpatients with acute diarrhea in Lanzhou. Enzyme-linked immunosorbant assay (ELISA) was used to detect rotavirus antigen (RVA). Reverse transcription-polymerase chain reactions (RT-PCR) were used to detect HuCV in stool specimens of RV ELISA (-).

RESULTSOf the stool specimens collected from 515 cases in Lanzhou from December 2001 to June 2004, 264 were RVA ELISA (+) and 251 were RVA ELISA (-). Among all cases who were RVA ELISA (-), 25 (9.96%) were found positive for HuCV. HuCV was detected in 12 of 133 cases (9.02%) from December 2001 to November 2002, no genotyping was performed for these cases. From July 2003 to June 2004 13 of 118 cases (11.02%) were found positive for HuCV, of whom 11 cases had Norwalk-like virus GII (NLV GII) infection and 2 cases had Sapporo-like virus infection (one case had combined infection with astrovirus) and no NLV GI was found. HuCV infection mainly occurred in children under 2 years of age and no seasonal cluster was found.

CONCLUSIONHuCV is one of the major etiological agents of viral diarrhea among infants and young children in Lanzhou. NLV GII maybe the predominant genotype.

Caliciviridae ; genetics ; Caliciviridae Infections ; epidemiology ; Child, Preschool ; China ; epidemiology ; Diarrhea ; epidemiology ; virology ; Enzyme-Linked Immunosorbent Assay ; Feces ; virology ; Genotype ; Humans ; Infant ; Molecular Epidemiology ; RNA, Viral ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Objective To explore the predictors on the abundance of Rattus (R.) tanezumi in households of commensal rodent plague foci.Methods Thirty natural villages that experienced previous plague cases in Lianghe county,Yunnan province,were selected followed by random selection of 20 households in each village through computer technique.Live traps were set in households to capture small mammals which were then identified to species in the field according to their morphological features.Data on potential factors for abundance of R.tanezumi were collected through questionnaires and field observation and were coded and computerized using EpiData software and further analyzed by hurdle regression model under R software.Results A total of 166 rodents (133 R.tanezumi and 33 Suucus murinus) were captured.Results from final multilevel hurdle regression model showed that the likelihood of R.tanezumi captures increased by 1.67-to 2.76-fold in households belonged to Dai ethnic families that stored foodstuff in metal pails,often raising dogs,and having adjacent houses.The number of R.tanezumi captures increased by 2.18-fold in the villages where over 80％ of the households would raise chickens.In the villages with communal latrine,the likelihood and the number of R.tanezumi capture increased 1.93-fold and 2.38-fold,respectively.While the likelihood of R.tanezumi captures would reduce by 45％-61％ in those households where there were cats and cattle being raised and maize grown in the village.The number of R.tanezumi captures would reduce by 63％ in the households where there were outside toilets.Conclusion The abundance of R.tanczumi seemed to be closely related to the ecological environment factors.Programs on plague control and prevention should relate to ecological factors that influencing the abundance of R.tanezumi.

Hemorrhagic fever with renal syndrome (HFRS) is a category B infectious disease caused by hantaviruses that cause acute kidney injury and has a high mortality rate, and HFRS control has been given a high priority in China. It has been found that hantavirus types are closely associated with selective host transformation and regional adaption, and continue to evolve in the form of gene recombination. The severity of HFRS varies in hantavirus types. In addition, global environmental changes and alteration of host animal behaviors accelerate Hantavirus genome variations, and large-scale land reclamation and infrastructure building increases the likelihood of human contacts with hosts and disease-transmitting vectors, thereby increasing the risk of HFRS development. This review summarizes the main characteristics and influencing factors pertaining to the epidemic process of HFRS, so as to provide insights into effective prevention and control of this infectious disease.

0.05).Moreover,the growth curves of the two kinds of cells were similar.Con- clusions The cell growth properties of cultured transplanted rabbit SMG are similar to that of normal SMG,the cytobiological charac- teristic of transplanted autologous free rabbit SMG are not changed evidently.