[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-Whi...[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-White classification method was employed to analyze the serotypes of Salmonel a strains. Minimum in-hibition concentration （MIC） of Salmonel a strains against 19 common antimicrobial drugs was analyzed determined with microdilution method. The class I integrons and carried drug resistance gene cassettes were detected by PCR. [Result] A total of 311 Salmonel a strains were isolated and classified into two serotypes, including 133 Salmonel a Indiana strains and 178 Salmonel a Enteritidis strains. Drug sensitivity test showed that the isolated Salmonel a strains were general y resistant to sulfadiazine, sulfamethoxazole, nalidixic acid, ampicil in, tetracycline, doxycycline and trimethoprim, with a multidrug resistance rate of 91.0% （283/311）; 99% strains were sensitive to amikacin and colistin. PCR assay indicated that the detection rate of class I integrons was 65.0% （202/311）; the positive rate of class I integrons in Salmonel a strains with multidrug resistance was 92.6%; among 202 positive strains, six strains carried gene cassette dfr17-aadA5. [Conclusion] According to the above results, class I integrons exist general y in Salmonel a and are closely associated with the multidrug resistance of Salmonel a strains.展开更多
On the global scale, hepatitis B virus(HBV) infection is the main cause of hepatocellular carcinoma(HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of...On the global scale, hepatitis B virus(HBV) infection is the main cause of hepatocellular carcinoma(HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However,the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.展开更多
Long-term in vitro maintenance of embryonic stem cell (ESC) pluripotency enables the pluripotency and differentiation of ESCs in animals to be investigated. The ability to successfully maintain and differentiate chick...Long-term in vitro maintenance of embryonic stem cell (ESC) pluripotency enables the pluripotency and differentiation of ESCs in animals to be investigated. The ability to successfully maintain and differentiate chicken embryonic stem cells (cESCs) would provide a useful tool for avian biology research and would be a resource directly applicable to agricultural production. In this study, endogenous chicken pluripotency transcription factors, POUV, Sox-2, Nanog and Lin28 were cloned and expressed as recombinant proteins containing a nine consecutive arginine protein transduction domain (PTD). cESCs were cultured with these recombinant proteins to maintain cESC pluripotency in vitro. Cultured cESCs exhibited typical characteristics of pluripotency, even after six generations of rapid doubling, including positive staining for stage-specific embryonic antigen I, and strong staining for alkaline phosphatase. Expression levels of the pluripotency markers, POUV, Nanog, C-Myc, Sox-2 and Lin28 were the same as in uncultured stage X blastoderm cells, and most significantly, the formation of embryoid bodies (EBs) by 6th generation cESCs confirmed the ability of these cultured cESCs to differentiate into cells of all three embryonic germ layers. Thus, transcription factors could be translocated through the cell membrane into the intracellular space of cESCs by using a PTD of nine consecutive arginines and the pluripotency of cESCs could be maintained in vitro for at least six generations.展开更多
基金Supported by National Natural Science Foundation of China(31201949,31172362)~~
文摘[Objective] This study aimed to investigate the multidrug resistance and prevalence of class I integrons in Salmonel a. [Method] Salmonel a strains were isolated from chicken farms in Shandong Province. Kauffmann-White classification method was employed to analyze the serotypes of Salmonel a strains. Minimum in-hibition concentration （MIC） of Salmonel a strains against 19 common antimicrobial drugs was analyzed determined with microdilution method. The class I integrons and carried drug resistance gene cassettes were detected by PCR. [Result] A total of 311 Salmonel a strains were isolated and classified into two serotypes, including 133 Salmonel a Indiana strains and 178 Salmonel a Enteritidis strains. Drug sensitivity test showed that the isolated Salmonel a strains were general y resistant to sulfadiazine, sulfamethoxazole, nalidixic acid, ampicil in, tetracycline, doxycycline and trimethoprim, with a multidrug resistance rate of 91.0% （283/311）; 99% strains were sensitive to amikacin and colistin. PCR assay indicated that the detection rate of class I integrons was 65.0% （202/311）; the positive rate of class I integrons in Salmonel a strains with multidrug resistance was 92.6%; among 202 positive strains, six strains carried gene cassette dfr17-aadA5. [Conclusion] According to the above results, class I integrons exist general y in Salmonel a and are closely associated with the multidrug resistance of Salmonel a strains.
基金supported by the State Key Project for Liver Cancer(2012ZX10002009)National Natural Science Foundation of China(81301811,81521091,81422032,81272212,81672860,81372674,and 91529303)+1 种基金Science Foundation of Shanghai(134119a3700)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA12010201)
文摘On the global scale, hepatitis B virus(HBV) infection is the main cause of hepatocellular carcinoma(HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However,the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.
基金assisted by the National Key Lab of Agro Biotechnology
文摘Long-term in vitro maintenance of embryonic stem cell (ESC) pluripotency enables the pluripotency and differentiation of ESCs in animals to be investigated. The ability to successfully maintain and differentiate chicken embryonic stem cells (cESCs) would provide a useful tool for avian biology research and would be a resource directly applicable to agricultural production. In this study, endogenous chicken pluripotency transcription factors, POUV, Sox-2, Nanog and Lin28 were cloned and expressed as recombinant proteins containing a nine consecutive arginine protein transduction domain (PTD). cESCs were cultured with these recombinant proteins to maintain cESC pluripotency in vitro. Cultured cESCs exhibited typical characteristics of pluripotency, even after six generations of rapid doubling, including positive staining for stage-specific embryonic antigen I, and strong staining for alkaline phosphatase. Expression levels of the pluripotency markers, POUV, Nanog, C-Myc, Sox-2 and Lin28 were the same as in uncultured stage X blastoderm cells, and most significantly, the formation of embryoid bodies (EBs) by 6th generation cESCs confirmed the ability of these cultured cESCs to differentiate into cells of all three embryonic germ layers. Thus, transcription factors could be translocated through the cell membrane into the intracellular space of cESCs by using a PTD of nine consecutive arginines and the pluripotency of cESCs could be maintained in vitro for at least six generations.
