Molecular epidemiology of Echovirus 30 in Fujian, China between 2001 and 2011.

Echovirus 30 (E-30) was responsible for an outbreak of aseptic meningitis between April 1 and June 2, 2011 in Fujian Province, China. A molecular epidemiology study of 115 E-30 strains was performed to characterize the genetic features of the etiologic agent of the 2011 aseptic meningitis outbreak. The phylogenetic trees of the complete VP1 gene (876 bp) from 74 of 115 isolates and 50 reference sequences were analyzed. Three lineages (E-30_h, i, and j) were detected that had co-circulated in Fujian in the last decade, of which E-30_j was new. The other 72 Fujian strains and 16 representative strains from other provinces of China all belong to E-30_h and E-30_i. Two distinct E-30 clusters including virus isolates obtained during adult surveillance were associated with the 2011 outbreak and differed from Fujian isolates prior to 2011, suggesting that the viruses may vary and adult infections play an important role in viral transmission. Thus, the multiple lineages of E-30 in Fujian and variant viruses enhanced transmissibility, which may be related to the epidemic activity of E-30.

Protective Effect of Selenoprotein X Against Oxidative Stress-Induced Cell Apoptosis in Human Hepatocyte (LO2) Cells via the p38 Pathway.

Oxidative stress, as mediated by ROS (reactive oxygen species), is a significant factor in initiating the cells damaged by affecting cellular macromolecules and impairing their biological functions; SelX, a selenoprotein also known as MsrB1 belonging to the methionine sulfoxide reductase (Msr) family, is the redox repairing enzyme and involved in redox-related functions. In order to more precisely analyze the relationship between oxidative stress, cell oxidative damage, and SelX, we stably overexpressed porcine Selx full-length cDNA in human normal hepatocyte (LO2) cells. Cell viability, cell apoptosis rate, intracellular ROS, and the expression levels of mRNA or protein of apoptosis-related genes under H2O2-induced oxidative stress were detected. We found that overexpression of SelX can prevent the oxidative damage caused by H2O2 and propose that the main mechanism underlying the protective effects of SelX is the inhibition of LO2 cell apoptosis. The results revealed that overexpressed SelX reduced the H2O2-induced intracellular ROS generation, inhibited the H2O2-induced upregulation of Bax and downregulation of Bcl-2, and increased the mRNA and protein ratio of Bcl-2/Bax. Furthermore, it inhibited H2O2-induced p38 MAPK phosphorylation. Taken together, our findings suggested that SelX played important roles in protecting LO2 cells against oxidative damage and that its protective effect is partly via the p38 pathway by acting as a ROS scavenger.

[Expression and roles of corticotropin-releasing hormone, cortisol and dehydroepiandrosterone sulfate in preterm labour].

OBJECTIVE: To investigate the effect of corticotropin-releasing hormone (CRH), cortisol and dehydroepiandrosterone sulfate in pathogenesis of preterm labor. METHODS: A cross-sectional study was conducted including 80 pregnant women in the following categories: (1) preterm delivery in labor (PL, n=26), (2) term in labor (TL, n=29), (3) term not in labor (n=25). The expression and localizations of CRH mRNA in placentas and fetal membranes in three groups respectively were examined by in situ hybridization. Radioimmunoassay was used to detect the levels of corticotropin releasing hormone, cortisol and dehydroepiandrosterone sulfate in fetal umbilical cord blood in three groups. RESULTS: (1) By in situ hybridization, we localized CRH mRNA to the syncytiotrophoblasts of placenta, the amniotic epithelial cells and chorion cells. (2) The positive index of expression of CRH mRNA in fetal membranes of PL (5.4 +/- 1.4) and TL, (5.4 +/- 1.5) was higher than that in term not in labor, (2.0 +/- 1.4, P<0.01). And there was no difference between PL and TL (P>0.05). The positive index of expression of CRH mRNA in placentas of PL (5.5 +/- 1.4) and TL (5.4 +/- 1.5) was higher than that in term not in labor (2.7 +/- 1.5, P<0.01). And there was no difference between PL and TL (P>0.05). The expression of CRH mRNA was not distinct between placentas and fetal membranes in three groups (P>0.05). (3) The levels of CRH and DHEA-S in umbilical cord blood of PL (7.8 +/- 3.3) ng/L, and (514 +/- 295) microg/L, respectively and of TL (7.7 +/- 4.1) ng/L, and (483 +/- 207) microg/L, were higher than that in term not in labor (4.8 +/- 2.4) ng/L, and (360 +/- 80) microg/L, respectively (P<0.05). And there was no difference between PL and TL (P>0.05). In PL, the level of CRH in umbilical cord blood and the expression of CRH mRNA in placentas and fetal membranes were correlated with each other (r=0.935 and 0.853, P<0.01). Also in TL, the levels of CRH and CRH mRNA were correlated with each other (r=0.902 and 0.825, P<0.01). (4) The level of cortisol in umbilical cord blood of PL (246 +/- 117) microg/L was higher than that in TL (172 +/- 72) microg/L (P<0.05) and term not in labor (126 +/- 60) microg/L (P<0.01). And the levels of cortisol in umbilical cord blood of TL were higher than that in term not in labor (P<0.05). In PL, the levels of CRH and cortisol and dehydroepiandrosterone sulfate in umbilical cord blood were correlated respectively with each other (r=0.523 and 0.424, P<0.05), and in TL the level of CRH was correlated with cortisol and dehydroepiandrosterone sulfate respectively (r=0.438 and 0.354, P<0.05). CONCLUSIONS: (1) CRH may participate in onset of labor. Increase in CRH may be an important stimulator of preterm labor. (2) Cortisol and dehydroepiandrosterone sulfate play an important role in the initiation of labor.

[Analysis of neutralized antibody level of the poliomyelitis in healthy population in Fujian province].

OBJECTIVE: To understand the neutralized antibody level of the poliomyelitis among healthy people and provide scientific evidence for the immunization strategy since routine and intensified immunization with oral polio vaccine (OPV) in Fujian province. METHODS: The poliomyelitis antibody level of healthy people were detected by neutralization test of the micro cells. RESULTS: The neutralizing antibody positive rates were 99.0%, 99.3%, 97.5% and GMTs were 1:79.1, 1:31.2, 1:24.7 for polio I, II, III respectively in 400 serum specimens from 1-59 years old. GMTs present a trend of decreasing as age's increasing. CONCLUSION: A protective barrier had been built against poliomyelitis in healthy people in Fujian province through routine and intensified immunization with OPV.

[Molecular identification and genetic analysis of an echovirus 19-associated epidemic of aseptic encephalitis].

OBJECTIVE: To ascertain the pathogen of aseptic encephalitis epidemic in Long-Yan city in Fujian, and to find out the genetic characteristics of the virus. METHODS: Rapid detection of enteroviral RNA by reverse transcription polymerasechain reaction (RT-PCR) was directly carried out in cerebrospinal fluid(CSF) to isolate and identify the viruses from CSF at the same time, and to detect the neutralization antibody in two serum specimens collected in acute and convalescence phase. Nucleotides of VP1 region was also analyzed by constructing phylogenetic tree. RESULTS: ECHO 19 infection was rapidly diagnosed and sequence analysed by RT-PCR, and then echovirus type 19 from 16 of 30 CSF samples (53.33%) was isolated and detected using RD and Hep-2 cells simultaneity. The titer of ECHO 19 neutralization antibody became positive or increased by 4 times from acute to convalescence phase in 4 of the 5 patients. Phylogenetic analyses of the VP1 genes of these isolates showed that their nucleotides identity were 98.9% -100.0% which were different from those ECHO 19 from GeneBank database by 13.0%-22.4%. CONCLUSION: The etiology of the epidemic of aseptic encephalitis was attributed to ECHO 19. The method of molecular identification not only provided rapid diagnosis of enterovirus infections, but also information about the genetic character of the viruses.

Diversity of rotavirus strains among children with acute diarrhea in China: 1998-2000 surveillance study.

As part of a national rotavirus surveillance activity, we collected fecal specimens from 3,177 children with acute diarrhea in 10 regions of China between April 1998 and April 2000 and screened them for rotavirus. Rotavirus was detected in 41% (n = 1,305) of specimens, and in these, G1 was the predominant serotype (72.6%), followed by G3 (14.2%), G2 (12.1%), G4 (2.5%), G9 (0.9%), and G untypeable (0.7%). Among 327 G-typed strains tested for P genotype, 14 different P-G combinations were identified, with the globally common strains P[8]G1, P[4]G2, P[8]G3, and P[8]G4 representing 75.6% of all typed rotavirus strains. Among the uncommon strains, 11 were P[6]G9, and others included P[6]G1, P[6]G3, and five novel P-G combinations (P[9]G1, P[4]G1, P[4]G3, P[4]G4, and P[8]G2). Our results indicate that while the common rotavirus strains remain predominant, the diversity of strains is much greater than was previously recognized.