Biomedical subjects

Hongtao Fan

Publications and source records attributed to Hongtao Fan.

6 recordsLinked to original sources

PubMed2005

The transcriptome in blood: challenges and solutions for robust expression profiling.

Peripheral blood may be the most feasible tissue source in clinical assessment of differences in gene expression between diseases and drug treatments due to accessibility. Yet, gene expression profiling from blood remains a challenge. Blood is a complicated biological system consisting of a variety of cell types at different stages of development. In addition, blood is also one of the most variable tissue types for gene expression analysis. The success of a blood microarray study depends on the choice of cell isolation method and preparation technique. In this review, we give a brief overview of the current status of using blood as a source for expression profiling and discuss potential applications of this method in the practices of clinical research.

Animals↗

PubMed2004

Synthesis of 1,1,4,4-tetrabromo-2-butenes and related compounds via desilylation-bromination of silylated 1,3-butadiene derivatives.

The combination of zirconocene-mediated coupling of silylated alkynes with a protonation-desilylation or bromination-desilylation process afforded otherwise unavailable butadiene derivatives. When (E,E)-2,3-dialkyl-1,4-bis(trimethylsilyl)-1,3-butadienes were treated with 3 equiv of Br(2) in CH(2)Cl(2), (E)-2,3-dialkyl-1,1,4,4-tetrabromo-2-butenes were obtained in excellent yields with perfect stereoselectivity.

Journal Article↗

PubMed2004

Comparative sequence analysis of imprinted genes between human and mouse to reveal imprinting signatures.

We performed a comparative genomic sequence analysis between human and mouse for 24 imprinted genes on human chromosomes 1, 6, 7, 11, 13, 14, 15, 18, 19, and 20. The MEME program was used to search for motifs within conserved sequences among the imprinted genes and we then used the MAST program to analyze for the presence or absence of motifs in the imprinted genes and 128 nonimprinted genes. Our analysis identified 15 motifs that were significantly enriched in the imprinted genes. We generated a logistic regression model by combining multiple motifs as input variables and the 24 imprinted genes and the 128 nonimprinted genes as a training set. The accuracy, sensitivity, and specificity of our model were 98, 92, and 99%, respectively. The model was further validated by an open test on 12 additional imprinted genes. The motifs identified in this study are novel imprinting signatures, which should improve our understanding of genomic imprinting and the role of genomic imprinting in human diseases.

Amino Acid Motifs↗

PubMed2002

IL-12 plays a significant role in the apoptosis of human T cells in the absence of antigenic stimulation.

Interleukin-12 (IL-12) is an immunoregulatory cytokine that plays an essential role in cell-mediated immunity. It is known to induce T cell apoptosis in in vivo systems such as graft-versus-host disease (GVHD) and experimental autoimmune uveitis (EAU). However, the role of IL-12 in T cell apoptosis in the absence of antigenic stimulation has not been clearly defined. This study was conducted to investigate whether IL-12, in the absence of an antigen, is able to induce T cell apoptosis, and also, which signalling pathways utilized by IL-12 are involved in this process. Our data clearly showed that IL-12 in the absence of an antigen induces apoptosis in T cells. Flow cytometry and ELISA showed FasL up-regulation and increased IFN-gamma synthesis in IL-12 treated T cells, while Fas and TNF-R1 showed little change. Semi-quantitative RT-PCR demonstrated that IL-12 was able to up-regulate TNF-alpha and FasL mRNA expression. Furthermore, IL-12 induced apoptosis was associated with caspase-3, caspase-2, caspase-7, DNA fragmentation factor 45 (DFF45) and Fas associated death domain (FADD) whereas TNF receptor associated death domain (TRADD) and receptor interacting protein (RIP) were not. Inhibition of Janus tyrosine kinase (JAK) was able to suppress IL-12 induced T cell apoptosis. Anti-FasL antibody was able to block IL-12 induced T cell apoptosis. In conclusion, our findings suggest that IL-12 is able to induce T cell apoptosis in the absence of an antigen. In addition, the present data suggest that this process is FasL mediated and caspase-3 dependent. Furthermore, JAK was shown to be involved in this process. These results may have significant implications in the understanding of IL-12 mediated T cell apoptosis.

Antibodies, Monoclonal↗

PubMed2000

[Study on Methylation of p15(INK4B) Gene in Acute Myeloid Leukemia and Chronic Myeloid Leukemia]

In order to explore the role of p15(INK4B) gene with highly methylated CpG island in the pathogenesis of leukemia, the expression levels of p15(INK4B) gene was detected in patients with AML and CML. Methylation-specific PCR (MSP) assay was employed in the experiments. The methylation incidence was 83.9% (26/31) in AML and 0% (0/28) in CML. The results showed that methylation of p15(INK4B) gene was the one of the major ways for inactivation of the gene, and the methylation could be appeared in clinical development of the disease and patients condition worsened. Methylation of p15(INK4B) did not occur and its function probably is normal in CML.

Journal Article↗

PubMed2000

[Detection of High Methylation of p15(INK4B) and p16(INK4A) Genes in Multiple Myeloma]

To study the action, characteristics and expression of high methylation of p15(INK4B) and p16(INK4A) genes in multiple myeloma (MM), the sensitive methylation specific PCR method was employed to detect the hypermethylation of p15(INK4B) and p16(INK4A) in 24 patients with MM. Results showed that the methylation incidence of p15(INK4B) and p16(INK4A) genes were 70.8% (17/24) and 58.3% (14/24) in the MM patients, with the products of 148 bp and 150 bp fragments, respectively. The methylation of p15(INK4B) and p16(INK4A) genes were simultaneously happened in MM patients of plasmocytoma type with two cases at II phase and two cases at III phase. The simultaneous non-methylation of p15(INK4B) and p16(INK4A) genes were founded in five cases of MM patients, all of the tumor cells were of small plasmocyte type with mature differention. Conclusion suggested that there were high incidence of methylation of p15(INK4B) and p16(INK4A) genes in patients with MM. Hypermethylation can be detected in the early stage of disease, which was associated with its progress. It indicated a bad prognosis when methylation happended simultaneously in the two genes. Methylation of p15(INK4B) and p16(INK4A) genes may be related to the pathogeny of MM.

Journal Article↗