AIM:To investigate the expression of 4-1BB molecule in hepatocellular carcinoma (HCC) and its adjacent tissues.METHODS:Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression...AIM:To investigate the expression of 4-1BB molecule in hepatocellular carcinoma (HCC) and its adjacent tissues.METHODS:Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of 4-1BB in hepatocarcinoma and its adjacent tissues,and peripheral blood mononuclear cells (PBMCs) from both HCC and health control groups.Flow cytometry was used to analyse the phenotypes of T cell subsets from the blood of HCC patients and healthy volunteers,and further to determine whether 4-1BB molecules were also expressed on the surface of CD4+ and CD8+ T cells. The localization of 4-1BB proteins on tumor infiltrating T cells was determined by direct immunofluorescence cytochemical staining and detected by confocal microscopy.RESULTS:4-1BB mRNA, which was not detectable in normal liver,was found in 19 liver tissues adjacent to tumor edge(<1.0cm).Low expression of 4-1BB mRNA was shown in 8 tumor tissues and 6 liver tissues located within 1 to 5cm away from tumor edge. In PBMCs, 4-1BB mRNA was almost not detected. Percentage of CD4^+, CD8^+ and CD3^+/CD25^+ T cells, as well as ratio of CD4 to CD8 revealed no difference between groups (P>0.05,respectively),while a significant lower percentage of CD3^+ T cell was found in HCC group as compared to healthy control group (P<0.05).However, 4-1BB molecules were almost not found on the surface of CD4+ and CD8+ T cells in HCC and healthy control group.Double-staining of 4-1BB^+/CD4^+ and 4-1BB^+/CD8^+ immunofluorescence on tumor infiltrating T cells was detected in 13 liver tissues adjacent to tumor edge (<1.0cm) by confocal microscopy.CONCLUSION: Although HCC may escape from immune attack by weak immunogenicity or downregulated expression of MHC-1 molecules on the tumor cell surface,tumor infiltrating T cells can be activated via other costimulatory signal pathways to exert a limited antitumor effect on local microenvironment. The present study also implicates that modulating 4-1BB/4-1BBL costimulatory pathway may be an effective immunotherapy strategy to augment the host response.展开更多
A magnetically stabilized fluidized bed (MSB) is a highly efficient filter that takes the advantage of both fluidized beds and fixed beds. This paper presents the research to collect aerosol in airflow with a MSB. The...A magnetically stabilized fluidized bed (MSB) is a highly efficient filter that takes the advantage of both fluidized beds and fixed beds. This paper presents the research to collect aerosol in airflow with a MSB. The filtering model of MSB is established with its parameters including magnetic field intensity, gas superficial velocity, average grain size, and bed height on the collection efficiency of MSB. The model is verified by experiments.展开更多
文摘AIM:To investigate the expression of 4-1BB molecule in hepatocellular carcinoma (HCC) and its adjacent tissues.METHODS:Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of 4-1BB in hepatocarcinoma and its adjacent tissues,and peripheral blood mononuclear cells (PBMCs) from both HCC and health control groups.Flow cytometry was used to analyse the phenotypes of T cell subsets from the blood of HCC patients and healthy volunteers,and further to determine whether 4-1BB molecules were also expressed on the surface of CD4+ and CD8+ T cells. The localization of 4-1BB proteins on tumor infiltrating T cells was determined by direct immunofluorescence cytochemical staining and detected by confocal microscopy.RESULTS:4-1BB mRNA, which was not detectable in normal liver,was found in 19 liver tissues adjacent to tumor edge(<1.0cm).Low expression of 4-1BB mRNA was shown in 8 tumor tissues and 6 liver tissues located within 1 to 5cm away from tumor edge. In PBMCs, 4-1BB mRNA was almost not detected. Percentage of CD4^+, CD8^+ and CD3^+/CD25^+ T cells, as well as ratio of CD4 to CD8 revealed no difference between groups (P>0.05,respectively),while a significant lower percentage of CD3^+ T cell was found in HCC group as compared to healthy control group (P<0.05).However, 4-1BB molecules were almost not found on the surface of CD4+ and CD8+ T cells in HCC and healthy control group.Double-staining of 4-1BB^+/CD4^+ and 4-1BB^+/CD8^+ immunofluorescence on tumor infiltrating T cells was detected in 13 liver tissues adjacent to tumor edge (<1.0cm) by confocal microscopy.CONCLUSION: Although HCC may escape from immune attack by weak immunogenicity or downregulated expression of MHC-1 molecules on the tumor cell surface,tumor infiltrating T cells can be activated via other costimulatory signal pathways to exert a limited antitumor effect on local microenvironment. The present study also implicates that modulating 4-1BB/4-1BBL costimulatory pathway may be an effective immunotherapy strategy to augment the host response.
文摘A magnetically stabilized fluidized bed (MSB) is a highly efficient filter that takes the advantage of both fluidized beds and fixed beds. This paper presents the research to collect aerosol in airflow with a MSB. The filtering model of MSB is established with its parameters including magnetic field intensity, gas superficial velocity, average grain size, and bed height on the collection efficiency of MSB. The model is verified by experiments.
