miR-203 inhibits lung cancer cell metastasis by targeting fatty acid binding protein 4 / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of fatty acid binding protein 4 (FABP4) in regulating lung cancer cell metastasis and identify miRNAs that target FABP4.</p><p><b>METHODS</b>The expression of FABP4 in lung cancer cells with different metastatic potentials was detected using enzyme-linked immunosorbent assay (ELISA) and Western blotting. The effects of FABP4 knockdown or overexpression by shRNA or a recombinant lentivirus, respectively, on lung cancer cells metastasis were assessed. The miRNAs that targeted FABP4 were screened using target prediction algorithms and the results were verified with Q-PCR.</p><p><b>RESULTS</b>FABP4 expression was significantly higher in lung cancer cell lines with high metastatic potentials (NL9980, H661, and 95C) than in those with low metastatic potentials (L9981, A549, and PC13) (P<0.05). FABP4 knockdown in NL9980 cells resulted in significantly inhibited metastasis of the cells (P<0.05), while FABP4 overexpression obviously promoted the metastasis of A549 cells (P<0.05). The expressions of miR-203, miR-361 and miR-539 were significantly higher in highly metastatic lung cancer cells than in the cells with low metastatic potentials (P<0.05). In NL9980 cells, FABP4 expression was most obviously suppressed by miR-203 (P<0.05), and target site mutational FABP4 overexpression significantly attenuated the inhibitory effect of miR-203 on NL9980 metastasis (P<0.05).</p><p><b>CONCLUSION</b>FABP4 can promote lung cancer metastasis, and by targeting FABP4 to inhibit its expression, miR-203 can suppress the metastasis of lung cancer cells.</p>

Synthesis of 13-β-elemene ester derivatives and evaluation of their antioxidant activity in human umbilical vein endothelial cells / 中国天然药物

In the present study, a series of 13-β-elemene ester derivatives were designed and prepared, and their antioxidant activity was investigated in the H2O2-treated human umbilical vein endothelial cells (HUVECs). Among the test compounds, the dimer compounds 5v and 5w exhibited the most potent antioxidant activity with significant ROS suppression being observed. Both compounds markedly inhibited the H2O2-induced changes in various biochemical substances, such as superoxide dismutase (SOD), malonyldialdehyde (MDA), nitric oxide (NO), and lactic dehydrogenase (LDH), which were superior to that of the positive control vitamin E. Further more, they did not produce any obvious cytotoxicity, but increased the viability of HUVECs injured by H2O2 in a dose-dependent manner. Additionally, compound 5w, designed as a prodrug-like compound, showed improved stability relative to compound 4 in vitro.

Prevalence and characterization of plasmid-mediated blaESBL with their genetic environment in Escherichia coli and Klebsiella pneumoniae in patients with pneumonia / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The extended spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) are the major pathogens causing pneumonia and have a significant impact on the clinical course. Limited data exist on molecular characterization of ESBL-producing E. coli and K. pneumoniae that cause pneumonia. The aim of this study was to investigate the comprehensive multilevel characteristics of E. coli and K. pneumoniae causing pneumonia in China for the first time.</p><p><b>METHODS</b>E. coli (17) and K. pneumoniae (21) isolates responsible for pneumonia were isolated from 1270 specimens collected in a prospective multi-center study in eight teaching hospitals in China from June to December in 2007. The susceptibilities, ESBL confirmation, sequence typing, blaCTX-M and blaSHV genes, their genetic environment and plasmid Inc/rep types were determined.</p><p><b>RESULTS</b>Sixteen E. coli (94.1%) and eleven K. pneumoniae (52.4%) isolates were ESBL producers. About 77.8% and 66.7% of them were resistance to ciprofloxacin and levofloxacin, and 100% were susceptible to imipenem. The most prevalent ESBL gene was CTX-M-14, followed by SHV-2, CTX-M-15, CTX-M-3, CTX-M-65, SHV-12, SHV-26 and SHV-28. SHV-1 and SHV-11 were also detected and coexisted with blaCTX-Ms in five strains, and three strains contained only SHV-1. All CTX-M-14 were detected ISEcp1 upstream and nine were found IS903 downstream and the majority of them (64.3%) were carried by IncF plasmids. All blaSHV were flanked by recF and deoR, located on IncF, IncN, IncX and IncH plasmids. Two SHV-2, one SHV-1 and the only SHV-28 were further preceded by IS26. Genes lacY and lacZ were detected at further upstream of two blaSHV-1. The K. pneumoniae carrying SHV-28 was susceptible to β-lactams, and no mutations or deletions in gene or promoter sequences were identified to account for susceptibility. Multilocus sequence typing experiments showed the ESBL-producing strains were genetically diverse.</p><p><b>CONCLUSIONS</b>The rate of occurrence of blaESBL in E. coli and K. pneumoniae causing pneumonia was high, and blaCTX-M-14 was dominant and probably mobilized by ISEcp1 mainly on IncF plasmids. Importantly, unexpressed blaESBL genes may occur in susceptible isolates and hence may have clinical implications.</p>

Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acinetobacter baumanii (A. baumanii ) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).</p><p><b>METHODS</b>Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.</p><p><b>RESULTS</b>Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-Ia was found in 23 strains, and the aac-6'-Ib gene in 19 strains. aac-3-Ia and aac-6'-Ib genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.</p><p><b>CONCLUSIONS</b>A. baumanii can carry multiple drug-resistant genes at the same time and result in multi-drug resistance. Aminoglycoside-modifying enzyme genes could be hibernating in aminoglycoside sensitive strains without expressing their phenotype.</p>

The analysis of "alpha" dominant mutation of hepatitis B virus in community-based Zhengding area, Hebei province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To determine the "alpha"dominant mutation of hepatitis B virus (HBV) in community-based Zhengding. Analysis the role of the newborn hepatitis B vaccination on the mutation.</p><p><b>METHODS</b>Based on the national surveillance of hepatitis B, 11,478 people's sera were collected and tested by SPRIA with kits. Collect people's sera with positive HBsAg and amplify the S gene. Sequencing and clastwaling them with the standard sequences.</p><p><b>RESULTS</b>Overall, HBV DNA was successfully amplified and sequenced in 434 of 443 samples. 6.7% samples mutated in HBV "alpha" dominant region. The difference between the mutation ratio of the two loops of HBV "alpha" dominant between the people born before and after the year 1986 has no significance.</p><p><b>CONCLUSION</b>There were HBV "alpha" dominant mutant virus in the local area with a low infection rate in the population born after the year 1986. It could not explain the newborn hepatitis B vaccination can induce the prevalence of the "alpha" dominant mutate HBV.</p>

The immunological effects of three doses of a live attenuated hepatitis A vaccine (H2 strain) in 8 years / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To observe the immunological effects of three doses of H2 strain live attenuated hepatitis A vaccine 8 years after the administration and to compare with that of one dose of the vaccine.</p><p><b>METHODS</b>In a country area, 110 children of 1 to 7 years old susceptible to HAV were screened and administered with one dose of the vaccine, as group B; Group A were 42 children from one of the villages and administered with 3 doses of the vaccine according to 0, 2, 6 month schedule. Blood samples were taken for the children 1, 2, 6, 7, 8, 12, 24, 36 and 96 months after the administrations respectively and detected for anti-HAV antibody.</p><p><b>RESULTS</b>For group B, the sero conversion rate of anti-HAV and GMC reached peak at 92.2% and 126.2 mIU/ml respectively, and then, began to drop with time; For group A, after 2 dose of the vaccine, the sero-conversion rate reached 100%, and the GMC reached peak of 2 739 mIU/ml one month after the third dose at 7 months. So that, group A has a better short-term immunological effects than that of group B. During 36 through 96 months, the anti-HAV positive rate in group B was 75%-71% and 80-89 mIU/ml respectively, and comparatively in group A were 100% and 918.2-480.6 mIU/ml respectively. The differences between group A and B were significantly important.</p><p><b>CONCLUSION</b>A 3-dose schedule administration of H2 strain live attenuated hepatitis A vaccine has better immunological effects than 1-dose schedule in 8years and further observations are needed.</p>

Construction of the mutants of rice nonspecific lipid transfer protein and expression comparison in two kinds of thioredoxin fusion expression vectors / 生物工程学报

Five structural important residues of rice nonspecific lipid transfer protein LTP110 were mutated by site-directed mutagenesis. Sequence results showed that they were all mutated successfully. After trying various E. coli expression systems, thioredoxin fusion expression system was found to be a proper system to express wild type and mutant LTP110. cDNA sequences encoding wild type LTP110 and the mutants Y17A, P72L, R46A, D43A, C50A were cloned into two kinds of thioredoxin fusion expression vectors. The expression results were compared. In pTrxFus/GI724 expression system, wild type LTP110 and the mutants Y17A, P72L, R46A could be expressed at low level while D43A and C50A could not be expressed normally; in pET32a(+)/BL21 (DE3) trxB- expression system, wild type LTP110 and all mutant proteins could be expressed very well and the levels were higher than that in pTrxFus/GI724 system. LTP110 fusion protein expressed in pET32a(+) vector was purified and its activity was checked by fluorescence labeled fatty acid. Results indicated that the recombinant LTP110 fusion protein has lipid binding activity. This work provides good basis for the further study.