Biomedical subjects

Bin Xiong

Publications and source records attributed to Bin Xiong.

12 recordsLinked to original sources

PubMed2003

Cyclooxygenase-2 expression and angiogenesis in colorectal cancer.

AIM: Cyclooxygenase-2 is involved in a variety of important cellular functions, including cell growth and differentiation, cancer cell motility and invasion, angiogenesis and immune function. However, the role of cyclooxygenase-2 as an angiogenic factor in colorectal cancer tissue is still unclear. We investigated the relationship between cyclooxygenase-2 and angiogenesis by analyzing the expression of cyclooxygenase-2 in colorectal cancer tissue, as well as its association with vascular endothelial growth factor (VEGF) and microvascular density (MVD). METHODS: The expression of cyclooxygenase-2, VEGF, as well as MVD was detected in 128 cases of colorectal cancer by immunohistochemical staining. The relationship between the cyclooxygenase-2 and VEGF expression and MVD was evaluated. Our objective was to determine the effect of cyclooxygenase-2 on the angiogenesis of colorectal cancer tissue. RESULTS: Among 128 cases of colorectal cancer, 87 were positive for cyclooxygenase-2 (67.9 %), and 49 for VEGF (38.3 %), respectively. The microvessel counts ranged from 23 to 142, with a mean of 51.7 (standard deviation, 19.8). The expression of cyclooxygenase-2 was correlated significantly with the depth of invasion, stage of disease, metastasis (lymph node and liver), VEGF expression and MVD. Patients in T3-T4, stage III-IV and with metastasis had much higher expression of cyclooxygenase-2 than patients in T1-T2, stage I-II and without metastasis (P<0.05). The positive expression rate of VEGF (81.6 %) in the cyclooxygenase-2 positive group was higher than that in the cyclooxygenase-2 negative group (18.4 %, P<0.05). Also, the microvessel count (56+/-16) in cyclooxygenase-2 positive group was significantly higher than that in cyclooxygenase-2 negative group (43+/-12, P<0.05). The microvessel count in tumors with positive cyclooxygenase-2 and VEGF was the highest (60+/-18, 41-142, P<0.05), whereas that in tumors with negative cyclooxygenase-2 and VEGF was the lowest (39+/-16, 23-68, P<0.05). CONCLUSION: Cyclooxygenase-2 may be associated with tumor progression by madulating the angiogenesis in colorectal cancer tissue and used as a possible biomarker.

Adenocarcinoma↗

PubMed2003

[Temperature control in a combined therapeutic system for tumor].

Tumor combined therapeutic system, a kind of medical instrument to restrain and kill tumor, is based on radio frequency heating technique and biological heating effect theory. It can be used solely or in combination with chemotherapy and actinotherapy for tumor hyperthermia. Combined with hardware measurement and adjustment, as well as application of the improved PID algorithm to the system of temperature control, the required accurate temperature control which directly influences the curative effect is realized. The experimental results presented in this paper demonstrated that the equipment works stably and reliably, and it is of good usefulness.

Algorithms↗

PubMed2003

Putative hAPN receptor binding sites in SARS_CoV spike protein.

AIM: To obtain the information of ligand-receptor binding between the S protein of SARS-CoV and CD13, identify the possible interacting domains or motifs related to binding sites, and provide clues for studying the functions of SARS proteins and designing anti-SARS drugs and vaccines. METHODS: On the basis of comparative genomics, the homology search, phylogenetic analyses, and multi-sequence alignment were used to predict CD13 related interacting domains and binding sites in the S protein of SARS-CoV. Molecular modeling and docking simulation methods were employed to address the interaction feature between CD13 and S protein of SARS-CoV in validating the bioinformatics predictions. RESULTS: Possible binding sites in the SARS-CoV S protein to CD13 have been mapped out by using bioinformatics analysis tools. The binding for one protein-protein interaction pair (D757-R761 motif of the SARS-CoV S protein to P585-A653 domain of CD13) has been simulated by molecular modeling and docking simulation methods. CONCLUSION: CD13 may be a possible receptor of the SARS-CoV S protein, which may be associated with the SARS infection. This study also provides a possible strategy for mapping the possible binding receptors of the proteins in a genome.

Amino Acid Sequence↗

PubMed2003

Identification of probable genomic packaging signal sequence from SARS-CoV genome by bioinformatics analysis.

AIM: To predict the probable genomic packaging signal of SARS-CoV by bioinformatics analysis. The derived packaging signal may be used to design antisense RNA and RNA interfere (RNAi) drugs treating SARS. METHODS: Based on the studies about the genomic packaging signals of MHV and BCoV, especially the information about primary and secondary structures, the putative genomic packaging signal of SARS-CoV were analyzed by using bioinformatic tools. Multi-alignment for the genomic sequences was performed among SARS-CoV, MHV, BCoV, PEDV and HCoV 229E. Secondary structures of RNA sequences were also predicted for the identification of the possible genomic packaging signals. Meanwhile, the N and M proteins of all five viruses were analyzed to study the evolutionary relationship with genomic packaging signals. RESULTS: The putative genomic packaging signal of SARS-CoV locates at the 3' end of ORF1b near that of MHV and BCoV, where is the most variable region of this gene. The RNA secondary structure of SARS-CoV genomic packaging signal is very similar to that of MHV and BCoV. The same result was also obtained in studying the genomic packaging signals of PEDV and HCoV 229E. Further more, the genomic sequence multi-alignment indicated that the locations of packaging signals of SARS-CoV, PEDV, and HCoV overlaped each other. It seems that the mutation rate of packaging signal sequences is much higher than the N protein, while only subtle variations for the M protein. CONCLUSIONS: The probable genomic packaging signal of SARS-CoV is analogous to that of MHV and BCoV, with the corresponding secondary RNA structure locating at the similar region of ORF1b. The positions where genomic packaging signals exist have suffered rounds of mutations, which may influence the primary structures of the N and M proteins consequently.

Amino Acid Sequence↗

PubMed2003

A 3D model of SARS_CoV 3CL proteinase and its inhibitors design by virtual screening.

AIM: To constructed a three-dimensional (3D) model for the 3C like (3CL) proteinase of SARS coronavirus (SARS-CoV), and to design inhibitors of the 3CL proteinase based on the 3D model. METHODS: Bioinformatics analyses were performed to search the homologous proteins of the SARS-CoV 3CL proteinase from the GenBank and PDB database. A 3D model of the proteinase was constructed by using homology modeling technique. Targeting to the 3D model and its X-ray crystal structure of the main proteinase (Mpro) of transmissible gastroenteritis virus (TGEV), virtual screening was performed employing molecular docking method to identify possible 3CL proteinase inhibitors from small molecular databases. RESULTS: Sequence alignment indicated that the SARS-CoV 3CL proteinase was extremely homologous to TGEV Mpro, especially the substrate-binding pocket (active site). Accordingly, a 3D model for the SARS-CoV 3CL proteinase was constructed based on the crystal structure of TGEV Mpro. The 3D model adopts a similar fold of the TGEV Mpro, its structure and binding pocket feature are almost as same as that of TGEV Mpro. The tested virtual screening indicated that 73 available proteinase inhibitors in the MDDR database might dock into both the binding pockets of the TGEV Mpro and the SARS-CoV 3CL proteinase. CONCLUSIONS: Either the 3D model of the SARS-CoV 3CL proteinase or the X-ray crystal structure of the TGEV Mpro may be used as a starting point for design anti-SARS drugs. Screening the known proteinase inhibitors may be an appreciated shortcut to discover anti-SARS drugs.

Computational Biology↗

PubMed2003

Small envelope protein E of SARS: cloning, expression, purification, CD determination, and bioinformatics analysis.

AIM: To obtain the pure sample of SARS small envelope E protein (SARS E protein), study its properties and analyze its possible functions. METHODS: The plasmid of SARS E protein was constructed by the polymerase chain reaction (PCR), and the protein was expressed in the E coli strain. The secondary structure feature of the protein was determined by circular dichroism (CD) technique. The possible functions of this protein were annotated by bioinformatics methods, and its possible three-dimensional model was constructed by molecular modeling. RESULTS: The pure sample of SARS E protein was obtained. The secondary structure feature derived from CD determination is similar to that from the secondary structure prediction. Bioinformatics analysis indicated that the key residues of SARS E protein were much conserved compared to the E proteins of other coronaviruses. In particular, the primary amino acid sequence of SARS E protein is much more similar to that of murine hepatitis virus (MHV) and other mammal coronaviruses. The transmembrane (TM) segment of the SARS E protein is relatively more conserved in the whole protein than other regions. CONCLUSION: The success of expressing the SARS E protein is a good starting point for investigating the structure and functions of this protein and SARS coronavirus itself as well. The SARS E protein may fold in water solution in a similar way as it in membrane-water mixed environment. It is possible that beta-sheet I of the SARS E protein interacts with the membrane surface via hydrogen bonding, this beta-sheet may uncoil to a random structure in water solution.

Circular Dichroism↗

PubMed2002

TGF beta1 expression and angiogenesis in colorectal cancer tissue.

AIM: Transforming growth factor TGF beta1 is involved in a variety of important cellular functions,including cell growth and differentiation, angiogenesis, immune function and extracellular matrix formation. However, the role of TGF beta(1) as an angiogenic factor in colorectal cancer is still unclear. We investigate the relationship between transforming growth factor beta(1) and angiogenesis by analyzing the expression of transforming growth factor TGF beta(1) in colorectal cancer, as well as its association with VEGF and MVD. METHODS: The expression of TGF beta(1),VEGF, as well as MVD were detected in 98 colorectal cancer by immunohistochemical staining. The relationship between the TGF beta(1) expression and VEGF expression,MVD was evaluated. To evaluate the effect of TGF beta(1) on the angiogenesis of colorectal cancers. RESULTS: Among 98 cases of colorectal cancer,37 were positive for TGF beta(1) 37.8% 36 for VEGF 36.7% respectively. The microvessel counts ranged from 19 to 139.8, with a mean of 48.7(standard deviation,21.8). The expression of TGF beta(1) was correlated significantly with the depth of invasion, stage of disease, lymph node metastasis, VEGF expression and MVD. Patients in T3-T4, stage III-IV and with lymph node metastasis had much higher expression of TGF beta(1) than patients in T1-T2, stage I-II and without lymph node metastasis (P<0.05). The positive expression rate of VEGF(58.3%) in the TGF-beta(1) positive group is higher than that in the TGF-beta(1) negative group(41.7%, P<0.05). Also, the microvessel count (54+/-18) in TGF-beta(1) positive group is significantly higher than that in TGF-beta(1) negative group(46+/-15, P<0.05). The microvessel count in tumors with both TGF-beta(1) and VEGF positive were the highest (58+/-20 36-140, P<0.05). Whereas that in tumors with both TGF-beta(1) and VEGF negative were the lowest (38+/-16, 19-60, P<0.05). CONCLUSION: TGF beta(1) might be associated with tumor progression by modulating the angiogenesis in colorectal cancer and TGF beta(1) may be used as a possible biomarker.

Adult↗

PubMed2002

Transforming growth factor-beta1 in invasion and metastasis in colorectal cancer.

AIM: To investigate the role of TGFbeta1 in invasion and metastasis in colorectal cancer by analysing TGFbeta1 correlated with depth of tumor invasion, stage and metastasis. METHODS: Serum TGFbeta1 levels were determined in 50 patients with colorectal cancer and 30 healthy volunteers using a TGFbeta1 enzyme-linked immunosorbent assay. TGFbeta1 expression in primary and lymph node metastatic lesions were detected in 98 cases of colorectal cancer by immunohistochemical staining and in situ hybridization. RESULTS: Serum levels of TGFbeta1 in patients with colorectal cancer(40+/-18 microg.L(-1)) were significantly higher than those in the healthy control group(19+/-8 microg.L(-1)), P<0.05. Elevated levels of serum TGFbeta1 were found in 60 % of patients with colorectal cancer when the mean +2 s was used as the upper limit of the normal range (35.1 microg.L(-1)). Increases in serum TGFbeta1 levels were significantly associated with Duke's stage (P<0.05), but there was no significant difference between Duke's stage B patients and Duke's stage C patients. In the cytoplasm of cancer cells, TGFbeta1 was immunostained in 37.8 % (37/98) of colorectal cancer, and this expression was confirmed by in situ hybridization. Among 35 cases of colorectal cancer with lymph node metastatic lesions, TGFbeta1 positive staining was found in 18 (51.4 %) cases of primary tumor, and 25 (71.4 %) cases with lymph node metastatic lesions, respectively. Of 17 cases w ith no staining in the primary lesion, 7 (41.2%) casesshowed TGFbeta1 staining in the metastatic lesion. Serum TGFbeta1 levels and TGFbeta1 expression in colorectal cancer tissues were correlated significantly with depth of tumor invasion, stage and metastasis. Patients in stage C-D,T3-T4 and with metastasis had significantly higher TGFbeta1 levels than patients in stage A-B,T1-T2 and without metastasis (P<0.05). CONCLUSION: These results suggest that transforming growth factor-beta1 is closely related to the invasion and metastasis of colorectal cancer. It increased the invasive and metastatic potential of tumor by altering a tumor microenvironment. TGFbeta1 may be used as a possible biomarker.

Adult↗

PubMed2002

[Subcutaneous injection of plasmid VEGF gene: a method of gene therapy to enhance the viability of random skin flap].

OBJECTIVE: Gene therapy has been becoming one of the most attractive medical areas. But the using of gene therapy in plastic surgery is relatively scarce. Our purpose was to investigate the effect of naked plasmid encoding Vascular Endothelial Growth Factor on the viability of the random skin flap by directly injected subcutaneously. METHODS: 30 female Sprague-Dawley rats randomly divided into three groups. A random dorsal skin flap of 3 cm x 9 cm was elevated in each of the rats. And 1 ml double-distilled water solution was injected subcutaneously, which was only water in group 1 during the operation, 200 micrograms VEGF cDNA plasmid in group 2 during the operation, 200 micrograms pcDNA3.1/zeo(+)--VEGF in group 3, 24 hours before the operation, respectively. 7 days after the operation, all the animals were sacrificed by overdose anesthetic. The survival tissue was measured with planimetry. Two samples were harvested from each group for pathological check and immunohistochemical test. RESULTS: Immunohistochemical staining demonstrated that there was human VEGF deposited around the capillary in the flaps treated with VEGF gene. The flaps treated with VEGF gene had a larger percentage of survival skin (group 1 = 47% +/- 5.4%, group 2 = 65.4% +/- 6.3%, group 3 = 72.3% +/- 8.5%, P < 0.05). CONCLUSION: VEGF gene directly injected into subcutaneous can express VEGF. It makes the gene therapy simple and practical and will be promising future in the tissue transplantation.

Animals↗

PubMed2002

[Analysis of 5459 cleft lip and palate cases].

OBJECTIVE: To analyse the constitution of 5459 cleft lip and palate cases and to review the development of surgical treatment to them. METHODS: The data of the 5459 cleft lip and palate cases were collected and classified. The ratio of sex and disease pattern were calculated and analyzed statistically. Also, by means of classification of the disease pattern, the operation methods and the operation time, the change of the surgical methods and the first operation age were analyzed. RESULTS: In the cleft lip and palate cases, the sex ratio is different. There were obvious differences in the first operative ages in different periods. The main repair methods for cleft lip and palate changed with time. CONCLUSION: The male is more than the female in the cleft lip and palate patients. The average first operation age has been decreased and the main repair methods have changed since 1980.

China↗

PubMed2002

[Expression and clinical significance of IGF-II mRNA and bcl-2 protein in colorectal adenocarcinomas].

BACKGROUND & OBJECTIVE: Insulin-like growth factor II (IGF-II) can stimulate cell proliferation; B cell lymphoma 2 (bcl-2) protein can strongly inhabit cell apoptosis. Recently, the overexpression of IGF-II and bcl-2 in colorectal cancer has been found, but the combined detection of them has not been reported. The objective of this study was to investigate the relationship between the expression of IGF-II, bcl-2 and the invasion, metastases of colorectal adenocarcinomas and to analyze the clinical significance of combined detection of these factors. METHODS: Forty-eight paraffin embedded samples from colorectal adenocarcinomas were selected. IGF-II mRNA was detected by using in situ hybridization. The expression of bcl-2 and PCNA protein were determined immunohistochemically, and TUNEL technique was used to detect apoptosis. Ten normal colorectal tissues were used as controls. The positive cell ratio of cancers was calculated by computer. The specimens with positive cell ratio < or = 30% were defined as negative. RESULTS: The expressions of IGF-II mRNA and bcl-2 protein were significantly higher in colorectal adenocarcinomas (38.70% +/- 7.80% and 30.97% +/- 7.40%) than in normal colorectal tissues(23.12% +/- 4.07% and 12.69% +/- 1.31%) (P < 0.01) and were related to Dukes' stage and lymph node metastases but were not associated with patient's age, gender, tumor site, tumor size and tumor differentiation. A negative correlation was observed between IGF-II mRNA and bcl-2 protein (P < 0.05). A positive correlation between IGF-II mRNA and PCNA, apoptosis as well as a negative correlation between bcl-2 and apoptosis were observed (P < 0.01). There was no correlation between bcl-2 and PCNA (P > 0.05). The patients with IGF-II mRNA (+) and bcl-2 (-) were regarded as the worst prognosis. CONCLUSION: The overexpression of IGF-II and bcl-2 in colorectal adenocarcinomas play an important role in the pathogenesis, progression, invasion, and metastases of the tumor. Determination of both IGF-II and bcl-2 expression would be helpful for decision making of adjuvant therapy.

Adenocarcinoma↗

PubMed2002

[Study on multi-pole RF ablation system].

Radio frequency ablation has become a valuable method in treating cancers or tumors for its wide adaptability, better efficacy, convenience and safety. This paper introduces the research and development of a multipolar RF tumor therapy system based on the technology of destroying hypoxic cell. This is an intellectualized tumor curing system.

Animals↗