Biomedical subjects

Wenbing Wang

Publications and source records attributed to Wenbing Wang.

8 recordsLinked to original sources

PubMed2006

[The temperature control for cancer thermotherapy using interstitial microwave antenna].

The basic objective of microwave hyperthermia is to raise the temperature in the tumor tissue without overheating point for a long time. It's difficult to achieve uniform temperature distribution using the continuous heating without changing the antenna shape and inserting position. In this paper, the interstitial antenna worked in the frequency of 2450 MHz inserted into an infinite muscle model is studied. The Finite Difference Time Domoin (FDTD) method was used to calculate the electromagnetic field, while the finite difference method (FDM) was used to analyze the temperature distribution in tumor tissue. The simulation results show that the long-time evenly heating can be achieved by using the alternately heating process and the treatment area can be changed by adjusting input power.

Electromagnetic Phenomena↗

PubMed2005

Cloning and sequence analysis of the Antheraea pernyi nucleopolyhedrovirus gp64 gene.

Frequent outbreaks of the purulence disease of Chinese oak silkworm are reported in Middle and Northeast China. The disease is produced by the pathogen Antheraea pernyi nucleopolyhedrovirus (AnpeNPV). To obtain molecular information of the virus, the polyhedra of AnpeNPV were purified and characterized. The genomic DNA of AnpeNPV was extracted and digested with HindIII. The genome size of AnpeNPV is estimated at 128 kb. Based on the analysis of DNA fragments digested with HindIII, 23 fragments were bigger than 564 bp. A genomic library was generated using HindIII and the positive clones were sequenced and analysed. The gp64 gene, encoding the baculovirus envelope protein GP64, was found in an insert. The nucleotide sequence analysis indicated that the AnpeNPV gp64 gene consists of a 1,530 nucleotide open reading frame (ORF), encoding a protein of 509 amino acids. Of the eight gp64 homologues, the AnpeNPV gp64 ORF shared the most sequence similarity with the gp64 gene of Anticarsia gemmatalis NPV, but not Bombyx mori NPV. The upstream region of the AnpeNPV gp64 ORF encoded the conserved transcriptional elements for early and late stage of the viral infection cycle. These results indicated that AnpeNPV belongs to group I NPV and was far removed in molecular phylogeny from the BmNPV.

Amino Acid Sequence↗

PubMed2005

Alterations of lymphoid enhancer factor-1 isoform expression in solid tumors and acute leukemias.

Two major transcripts of lymphoid enhancer factor-1 (LEF-1) have been described. The long isoform with b-catenin binding domain functions as a transcriptional enhancer factor. The short isoform derives from an intronic promoter and exhibits dominant negative activity. Recently, alterations of LEF-1 isoforms distribution have been described in colon cancer. In the current study we employed a quantitative real-time reverse transcription PCR method (TaqMan) to analyze expression of LEF-1 isoforms in a large cohort of human tumor (n = 304) and tumor-free control samples (n = 56). The highest expression level of LEF-1 was found in carcinoma samples whereas brain cancer samples expressed little. Expression of LEF-1 was different in distinct cancer types. For example, the mRNA level of LEF-1 was lower in testicular tumor samples compared with tumor-free control samples. Besides epithelial cancers, significant LEF-1 expression was also found in hematopoietic cells. In hematological malignancies, overall LEF-1 level was higher in lymphocytic leukemias compared with myeloid leukemias and normal hematopoiesis. However, acute myeloid leukemia and acute lymphocytic leukemia showed a significantly increased fraction of the oncogenic LEF-1 compared with chronic lymphocytic leukemia and chronic myeloid leukemia. Taken together, these data suggest that LEF-1 is abundantly expressed in human tumors and the ratio of the oncogenic and the dominant negative short isoform altered not only in carcinomas but also in leukemia.

Biomarkers, Tumor↗

PubMed2005

Cloning of the nucleostemin gene and its function in transforming human embryonic bone marrow mesenchymal stem cells into F6 tumor cells.

We recently established a novel tumor cell line denominated as F6, which was derived from mutated human embryonic bone marrow mesenchymal stem cells (MSCs). The difference between gene expression of F6 cells and MSCs was distinguished by fluorescent differential display. Results showed that the expression of nucleostemin, a novel factor participating in the control of stem and cancer cell proliferation, was different in F6 cells and MSCs. To further understand its role in transforming human embryonic bone marrow mesenchymal stem cells into F6 tumor cells, the full-length nucleostemin gene (1650 bp) from an LTEP-a-2 cell line was cloned, and GST-nucleostemin protein was expressed in E. coli. The characteristics of nucleostemin expression in F6 cells and other human cancer cell lines were investigated by RT-PCR, Western blot analysis, immunocytochemical staining, fluorescent microscope and confocal laser scanning microscope. The levels of nucleostemin gene expression were detected by real-time PCR in F6 tumor tissue obtained from SCID nude mice at 4, 6 and 7 weeks after the injection of F6 cells, and from the lung tissue of five lung cancer patients. Results showed that nucleostemin gene expression increased significantly in F6 tumor tissue and lung cancer tissue. The results also showed that transfection with pcDNA3.1(+)-GFP-nucleostemin for 4-20 weeks promoted cell size augmentation and nuclei multiplication, and the cells were converted to giant cell-like cells. Western blot analysis revealed that expression levels of nucleostemin in the nuclei and cytoplasm of cancer cell lines, e.g. F6, LTEP-a-2, U937, SW480 and 95D, were higher than those in MSCs and COS-7 cells. Levels of nucleostemin in F6 cells were notably high and confirmed with immunohistochemical staining. These results implied that nucleostemin may play an important role in both tumorigenesis and transforming human embryonic bone marrow mesenchymal stem cells into F6 tumor cells.

Animals↗

PubMed2004

Identification of interaction partners and substrates of the cyclin A1-CDK2 complex.

The CDK2-associated cyclin A1 is essential for spermatogenesis and contributes to leukemogenesis. The detailed molecular functions of cyclin A1 remain unclear, since the molecular networks involving cyclin A1-CDK2 have not been elucidated. Here, we identified novel cyclin A1/CDK2 interaction partners in a yeast triple-hybrid approach. Several novel proteins (INCA1, KARCA1, and PROCA1) as well as the known proteins GPS2 (G-protein pathway suppressor 2), Ku70, receptor for activated protein kinase C1/guanine nucleotide-binding protein beta-2-like-1, and mRNA-binding motif protein 4 were identified as interaction partners. These proteins link the cyclin A1-CDK2 complex to diverse cellular processes such as DNA repair, signaling, and splicing. Interactions were confirmed by GST pull-down assays and co-immunoprecipitation. We cloned and characterized the most frequently isolated unknown gene, which we named INCA1 (inhibitor of CDK interacting with cyclin A1). The nuclear INCA1 protein is evolutionarily conserved and lacks homology to any known gene. This novel protein and two other interacting partners served as substrates for the cyclin A1-CDK2 kinase complex. Cyclin A1 and all interaction partners were highly expressed in testis with varying degrees of tissue specificity. The highest expression levels were observed at different time points during testis maturation, whereas expression levels in germ cell cancers and infertile testes decreased. Taken together, we identified testicular interaction partners of the cyclin A1-CDK2 complex and studied their expression pattern in normal organs, testis development, and testicular malignancies. Thereby, we establish a new basis for future functional analyses of cyclin A1. We provide evidence that the cyclin A1-CDK2 complex plays a role in several signaling pathways important for cell cycle control and meiosis.

Alternative Splicing↗

PubMed2003

MALAT-1, a novel noncoding RNA, and thymosin beta4 predict metastasis and survival in early-stage non-small cell lung cancer.

Early-stage non-small cell lung cancer (NSCLC) can be cured by surgical resection, but a substantial fraction of patients ultimately dies due to distant metastasis. In this study, we used subtractive hybridization to identify gene expression differences in stage I NSCLC tumors that either did or did not metastasize in the course of disease. Individual clones (n=225) were sequenced and quantitative RT-PCR verified overexpression in metastasizing samples. Several of the identified genes (eIF4A1, thymosin beta4 and a novel transcript named MALAT-1) were demonstrated to be significantly associated with metastasis in NSCLC patients (n=70). The genes' association with metastasis was stage- and histology specific. The Kaplan-Meier analyses identified MALAT-1 and thymosin beta4 as prognostic parameters for patient survival in stage I NSCLC. The novel MALAT-1 transcript is a noncoding RNA of more than 8000 nt expressed from chromosome 11q13. It is highly expressed in lung, pancreas and other healthy organs as well as in NSCLC. MALAT-1 expressed sequences are conserved across several species indicating its potentially important function. Taken together, these data contribute to the identification of early-stage NSCLC patients that are at high risk to develop metastasis. The identification of MALAT-1 emphasizes the potential role of noncoding RNAs in human cancer.

Carcinoma, Non-Small-Cell Lung↗

PubMed2003

[Clinical study on chitosan in curing irreducible anterior disc displacement of tempormandibular joint].

OBJECTIVE: To evaluate the clinical efficacy of intra-articular injection with 2% chitosan as a treatment for irreducible anterior disc displacement of the TMJ. METHODS: Total 30 patients with irreducible anterior disc displacement were divided into two groups according to quasi-randomizaion. The patients in test group received intra-articular injection with 1.0 ml of 2% chitosan into upper cavities of the suffered joints, in control group with 12.5 mg of prednisolone. The patients were followed up at the 1st day and 14th day after injection and the maximal mouth opening was measured. RESULTS: The maximal mouth opening at 14th day was (36.73 +/- 4.69) mm in test group, with 11.73 mm increase from baseline; and (28.53 +/- 5.81) mm in control group, with 3.86 mm increase, respectively. The increase of maximal mouth opening in test group was significantly higher than that of control group (P < 0.05). CONCLUSION: Chitosan is an effective biomaterial in curing irreducible anterior disc displacement of TMJs.

Adolescent↗

PubMed2002

[Research and development on microwave sterilization].

This paper reviews recent research and development on microwave sterilization, including the experiments of sterilization effects, the influence of microwave radiating on the media parameters, the development of microwave sterilizers and the study of sterilization mechanism. Many results show that the method of microwave sterilization is more easy-to-perform, economical and reproducible than the conventional autoclaving method. It is necessary to study the sterilization conditions through the experiments for different media and bacteria. The research on sterilization mechanism, especially non-thermal sterilization mechanism is still a hotpoint.

Bacteria↗