Expression of co-stimulator 4-1BB molecule in hepatocellular carcinoma and adjacent non-tumor liver tissue,and its possible role in tumor immunity

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.

Bone mineral density of the spine and femur in healthy Chinese men

Aim:To establish bone mineral density(BMD)reference database in healthy Chinese men of Han ethnicity,and to estimate the prevalence of osteoporosis in the population.Methods:The BMD in the lumbar spine 1-4(L1-4)and proximal femur was measured using dual energy X-ray absorptiometry in a total of 1385 healthy Chinese men of Han ethnicity aged 20-89 years old in Shanghai.Results:The highly significant negative correlation between age and BMD at any sites of proximal femur was found in the studied population,wheras no correlation between age and BMD at lumbar spine was observed.The peak BMD of the lumbar spine and any sites of hip in Chinese men was defined as the mean BMD for the subjects aged 20-39 years.According to World Health Organization(WHO)criteria,the BMD cut-off values for osteoporosis of the L1-4,total hip,femoral neck,trochanter and intertrochanter in Chinese men are 0.719,0.638,0.575,0.437 and 0.725 g/cm^2,respectively.Using the current Chinese reference data,the prevalence of osteoporosis at the L1-4,total hip,femoral neck,trochanter and intertrochanter is 5.4%,3.8%,6.3%, 1.8% and 2.8% in 1084 men aged 50 years or older,respectively.However,using a database for US non-Hispanic white men(NHANES Ⅲ),the prevalence of osteoporosis or osteopenia at any sites of the hip was significantly higher than that while using the current Chinese reference data.Conclusion:The BMD reference database was established in healthy Chinese men of Han ethnicity,and will facilitate more accurate diagnosis of osteoporosis in Chinese men. (Asian J Androl 2006 Jul;8:419-427)

Collecting aerosol in airflow with a magnetically stabilized fluidized bed

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 Geld intensity, gas superficial velocity, average grain-size, and bed height on the collection efficiency of MSB. The model is verified by experiments.

REACTION OF 3,7-DINITRODIBENZOBROMOLIUM BISULFATE WITHSOME NUCLEOPHILES

Reaction of 3,7-dinitrodibenzobromolium bisulfate with some nucleophiles were studied. Primary products of reactions ore 2-bromo-2'-Nu-4-4'-dinitro-biphenyls.