Biomedical subjects

Xiao Li

Publications and source records attributed to Xiao Li.

At least 55 records · Page 3Linked to original sources

PubMed2005

Magnetic resonance imaging of hepatocellular carcinoma induced by diethylnitrosamine in Sprague-Dawley rats.

BACKGROUND: Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various lesions occurring in humans than the usual model of tumor implantations. The aim of the present study was to evaluate MRI liver examination in Sprague-Dawley (SD) rats as a routine method to detect hepatocellular carcinoma (HCC) nodules induced by DENA and to follow up their growth. METHODS: Hepatic carcinogenesis was induced in 80 male SD rats using oral DENA solution. All animals were imaged for liver tumor detection with a 1.5 Tesla magnet (Siemens Sonata, Erlangen, Germany) using correspondence scan parameters and a radio-frequency knee coil. Macroscopic examinations were performed along the axial MRI sections to evaluate magnetic resonance imaging (MRI) findings, and histopathological assessment was also performed. RESULTS: No false negative results were obtained on MR images. Hepatic tumors in 72 rats were confirmed macroscopically and 68 rats were detected by MRI till the 20th week. The smallest and the largest nodules detected by MRI were 2 mm and 37 mm in diameter respectively. The agreement rate of MRI with macroscopic observation was 39.1% and 97.4% respectively for 2 mm to 5 mm and more than 5 mm nodules. CONCLUSIONS: The hepatic tumor induced by DENA provides a more representative range of tumors for imaging diagnosis and interventional treatment. MRI is the best approach for scrutinizing pathological changes of rat livers in the period of observation.

Alkylating Agents↗

PubMed2005

Proportion of CD4+CD25+ regulatory T cell is increased in the patients with ovarian carcinoma.

OBJECTIVE: To study the frequency of the CD4+CD25+ regulatory T cells (Tregs) in the patients with ovarian carcinoma and its possible mechanism. METHODS: The percentages of CD4+CD25+ Tregs in the peripheral blood lymphocytes (PBLs), tumor infiltrating lymphocytes (TILs) and tumor associated lymphocytes (TALs) from 13 patients with ovarian carcinoma and in the PBLs from 14 healthy women were determined by flow cytometry. The expression of CD69 on CD4+PBLs from the patients was detected. PBLs from healthy women were cultured in complete RPMI 1640 containing the supernatant from SKOV3 cell line with or without PHA (phytohemagglutinin) stimulation for 72 hours, then the percentage of CD4+CD25+ T cells was detected. RESULTS: CD4+CD25+ Tregs in the PBLs from patients with ovarian carcinoma were significantly increased compared with those from the control. The percentage of CD4+CD25+ Tregs in TILs was higher than that in PBLs and TALs from the patients, but not significantly. The expression of CD69 on CD4+PBLs from the patients was negative. The percentages of CD4+CD25+ T cells in PBLs cultured with SKOV3 supernatant elevated significantly compared with those without supernatant whether PHA was added or not (P=0.001 and 0.001, respectively). CONCLUSION: There is an increasing of the proportion of CD4+CD25+ Tregs in PBLs, TILs and TALs of the patients with ovarian carcinoma, which probably results from up-regulation of soluble factor secreted by ovarian carcinoma cells.

CD4-Positive T-Lymphocytes↗

PubMed2005

[Antitumor research on human laryngeal carcinoma with combined application of VP3 gene, IL-18 gene and HN gene].

OBJECTIVE: To research the antitumor efficacy on mice model bearing H22 tumor with application of pVVP3IL-18HN and its mechanism of the antitumor effect on Hep-2. METHOD: pVVP3IL-18HN was introduced into Hep-2 cells by liposome, then cellular morphology was observed through AO/EB stain. To evaluate the mechanism of the antitumor effect on Hep-2 of pVVP3IL-18HN and its effect on tumor immunogenicity, flow cytometer (FCM) was used to detect the variation of mitochondrial trans-membrane potential,reactive oxygen species (ROS) and the MHC-I. C57BL/6 mice were subcutaneously inoculated with 2 X 10(5) H22 tumor cells in the right hindlimb, and 7, 14 and 21 day post-inoculation, pVVP3IL-18HN was administrated intratumorally. The pVVP3, pVIL-18, PVHN and PBS control group were treated as above. Then the tumor suppression and specific cytotoxic T lymphocyte (CTL) activity was detected. RESULT: After the transfection of pVVP3IL-18HN, tumor cells crenated and stained by AO/EB. In the research pVVP3IL-18HN was found to up-regulate the value of ROS and the expression of MHC-I, and down-regulate the value of mitochondrial trans-membrane potential. The tumor suppression rate of pVVP3IL-18HN was 60.5% and a dramatically increased tumor suppression was revealed in the pVVP3IL-18HN treated mice as compared with control mice treated with PBS (P < 0.05). CONCLUSION: pVVP3IL-18HN kill the tumor cells by apoptosis and have notable antitumor effect in vivo.

Animals↗

PubMed2005

[Construction of the nucleic vaccine pVVP3L-18HN and its antitumor effect on human laryngeal carcinoma].

OBJECTIVE: Nucleic vaccine of pVVP3IL-18HN expressing apoptin gene, Newcastle disease virus HN gene and IL-18 gene were constructed to observe the combinative antitumor effect of the above three genes. METHODS: Eukaryotic expression plasmid pVVP3IL-18HN was constructed by inserting apoptin gene and fragment comprising fused IL-18HN gene and IRES promoter into the downstream of CMV promoter of vector pVAX1. The expression of inserted gene was identified by RT-PCR, indirect immunofluorescence and Western-blot. The recombinant plasmid was introduced into Hep-2 cells by liposome, then suppression rate of Hep-2 of different time and different quantity was calculated according to MTT results. RESULT: The recombinant plasmid of pVVP3IL-18HN suppressed Hep-2 successfully and its suppression rate was up to 61.9% with 20 microg/ml, incubation of 72 hours. CONCLUSION: The nucleic vaccine constructed pVVP3IL-18HN had antitumor effect on Hep-2. It may can be used to the therapy and research of laryngeal carcinoma.

Cancer Vaccines↗

PubMed2005

[Cytotoxicity of IFN-gamma-activated dendritic cells to freshly isolated acute myeloid leukemia cells].

To investigate the tumoricidal activity of dendritic cell (DC) stimulated by interferon-gamma (IFN-gamma) against freshly isolated myeloid leukemia cells and its mechanism, the peripheral blood monocytes collected from healthy donors were cocultured with interleukin-4 and granulocyte-macrophage colony-stimulating factor in medium to induce DC for 7 days. After 12 hour culture in the absence or presence of IFN-gamma, the changes of costimulatory molecules were analyzed with flow cytometry. To assay the cytotoxicity of DC against freshly isolated acute myeloid cells, they were cocultured at various effector-to-target ratio for 18 hours, then the percentage of tumoricidal activity was measured with (51)Cr release assay. To explore the mechanism of DC-mediated cytotoxicity, the change of DC surface or intracellular protein expression of Fas ligand (Fas L), TNF-alpha and TNF related apoptosis-inducing ligand (TRAIL) were analyzed with flow cytometry. The results showed that IFN-gamma enhanced cytotoxicity of DC against AML cells was (33.8 +/- 1.6)% at E:T as 20:1, compared with unstimulated DC (P < 0.05); IFN-gamma up-regulated expression of costimulatory molecules of DC surface such as CD86 and CD83; after stimulation with IFN-gamma, expression of intracellular TRAIL of DC was significantly enhanced, but expression of TRAIL on cell surface of DC was low; while the significant changes of Fas L and TNF-alpha expression neither on cell surface or in cells were not observed before or after stimulation with IFN-gamma. It is concluded that DC stimulated by IFN-gamma exhibit tumoricidal activity against AML cells. The cytotoxicity is partially related to maturation of DC and TRAIL inducing apoptosis, but not associated with death domain-independent mechanism of Fas L and TNF-alpha.

Acute Disease↗

PubMed2004

Hepatocellular carcinoma treated with interventional procedures: CT and MRI follow-up.

In the past decade, a variety of interventional procedures have been employed for local control of hepatocellular carcinoma (HCC). These include transcather arterial chemoembolization (TACE) and several tumour ablation techniques, such as percutaneous ethanol injection (PEI), radio-frequency ablation (RFA), or percutaneous microwave coagulation therapy (PMC), laser-induced interstitial thermotherapy (LITT), etc. For a definite assessment of the therapeutic efficacy of interventional procedures, histological examination using percutaneous needle biopsy may be the most definite assessment of the therapeutic efficacy of interventional therapy, however, it is invasive and the specimen retrieved does not always represent the entire lesion owing to sampling errors. Therefore, computed tomography (CT) and magnetic resonance imaging (MRI) play a crucial role in follow-up of HCC treated by interventional procedures, by which the local treatment efficacy, recurrent disease and some of therapy-induced complications are evaluated. Contrast enhanced axial imaging (CT or MR imaging) may be the most sensitive test for assessing the therapeutic efficacy. The goal of the review was to describe the value of CT and MRI in the evaluation of interventional treatments.

Carcinoma, Hepatocellular↗

PubMed2004

Successful management of a benign anastomotic colonic stricture with self-expanding metallic stents: a case report.

AIM: To assess the effectiveness of and complications associated with metallic stent placement for treatment of anastomotic colonic strictures. METHODS: A 46-year-old man undergoing two procedures of surgery for perforation of descending colon due to a traffic accident presented with pain, abdominal distention, and inability to defecate. Single-contrast barium enema radiograph showed a severe stenosis in the region of surgical anastomosis and the patient was too weak to accept another laparotomy. Under fluoroscopic and endoscopic guidance, we placed two metallic stents in the stenosis site of the anastomosis of the patient with anastomotic colonic strictures. RESULTS: In this case of postsurgical stenosis, the first stent relieved the symptoms of obstruction, but stent migration happened on the next day so an additional stent was required to deal with the stricture and relieve the symptoms. CONCLUSION: This case confirms that metallic stenting may represent an effective treatment for anastomotic colonic strictures in the absence of other therapeutic alternatives.

Colon↗

PubMed2004

Multidetector CT in evaluating blood supply of hepatocellular carcinoma after transcatheter arterial chemoembolization.

AIM: To assess the value of multidetector-row computed tomography (MDCT) in choosing retreatment methods of hepatocellular carcinoma (HCC) through evaluating the blood supply of low-density area of HCC after transcatheter arterial chemoembolization (TACE). METHODS: Thirty-two patients with HCC after TACE treatment were examined by plain scanning and hepatic multidetector-row CT. The location of low-density area on plain scanning and the enhancement patterns on dynamic contrast-enhanced scanning were observed. At the same time, three-dimensional CT (3D CT) models of the volume rendering, curved multiplanar reformations, surface shaded display and maximum intensity projection reconstruction of the hepatic artery and portal vein were performed in 6 cases. RESULTS: In CT plain scanning data, low density areas of 32 cases of HCC after TACE treatment were divided into three types: peripheral, one-side-located and mixed types. In contrast-enhanced CT scans, the blood supply of low-density area was classified into four types: arterial blood supply (20 cases), portal blood supply (5 cases), arterial combined with portal blood supply (5 cases) and poor blood supply (2 cases). In 6 cases, the relationship between the low-density area and branches of hepatic artery as well as portal vein was shown by 3D CT. CONCLUSION: Hepatic MDCT is an effective method for evaluating the blood supply of low-density area and therapeutic effect of HCC after TACE treatment. Types of blood supply is helpful for the selection of retreatment.

Adolescent↗

PubMed2004

Ovarian carcinoma cells inhibit T cell proliferation: suppression of IL-2 receptor beta and gamma expression and their JAK-STAT signaling pathway.

Deficient T cell immune function and intracellular signaling in cancer patients may result from effects of tumors or their products on lymphocytes. Recently, it was demonstrated that several ovarian carcinoma cell lines could produce soluble factors that inhibited T cell proliferation. The aim of this study is to assess the effect of supernatants from 3 ovarian carcinoma cell lines (OVCAR3, CAOV3, SKOV3) on signal transduction elements that are linked to the IL-2R and its JAK-STAT pathway. A profound inhibition of proliferation, lower level of IFN-gamma and higher level of IL-10 gene expression were observed when CD8+ T cells were co-cultured with supernatants from 3 ovarian carcinoma cell lines. Cell cycle studies on inhibited CD8+ T cells showed most of them were growth arrested in G0/G1 phase. Western blot analysis showed that tumor supernatants suppressed expression of JAK3 and tyrosine phosphorylation of STAT5. JAK1 was not altered and the inhibition of STAT3 only appeared in OVCAR3 cells. Tumor supernatants also partially blocked induction of IL-2R beta and gamma chains expression. These findings suggest that ovarian carcinoma cells may suppress T cell proliferation through inhibition IL-2 dependent signaling pathways, which may be a mechanism of ovarian carcinoma induced immunosuppression.

Blotting, Western↗

PubMed2004

Inhibitory effects of anti-sense PTTG on malignant phenotype of human ovarian carcinoma cell line SK-OV-3.

To construct eukaryotic expression vector expressing full length anti-sense pituitary tumor transforming gene (PTTG) mRNA and observe its blocking effect on the potential invasion of human ovarian carcinoma cell line SK-OV-3. PCR primers containing designed enzyme cut sites were used for cloning full-length PTTG gene fragment, and the resulting PCR product was inserted into the eukaryotic vector pcDNA3.1 in the antisense direction. The recombinant vector was then transfected into SK-OV-3 by Lipofectamine. The positive cell clone was screened by G418, PTTG and bFGF at protein level expression were detected by Western blot. The biological behavior change of transfection positive cells was observed by colony formation in soft agar assay. Our results showed that SK-OV-3 clones stably expressing full-length recombinant pcDNA3.1-PTTGas were obtained. The expressions of PTTG and bFGF protein in transfected cells were decreased by 61.5% and 52.3%, respectively as compared with non-transfected ones. The number of colony formation was reduced significantly in transfected cells as compared with empty vector transfected and non-transfected cells. It is concluded that the recombinant vector pcDNA3.1-PTTGas is a novel tool and provides an alternative anti-sense gene therapy targeted at PTTG in human carcinoma.

Cell Line, Tumor↗

PubMed2004

Simultaneous demonstration of clonal chromosome abnormalities and apoptosis in individual marrow cells in myelodysplastic syndrome.

Bone marrow samples from 18 patients with myelodysplastic syndrome (MDS) with clonal cytogenetic abnormalities were characterized by combining fluorescence in situ hybridization (FISH) with in situ end-labeling (ISEL) or with annexin V staining and flow cytometry (AV/FLOW) to determine the clonal nature of hematopoietic cells undergoing apoptosis in marrow cells. Apoptosis occurred in both normal and clonal cells. However, the proportion of clonal cells identified by FISH among apoptotic cells was lower than the proportion among nonclonal cells in 17 of 18 patients, regardless of whether ISEL or AV/ FLOW was used to identify apoptosis. This technique allows us to identify simultaneously clonality (as determined by FISH) and apoptosis in individual cells and shows that although apoptosis occurs predominantly in residual normal (FISH-negative) cells, a proportion of clonal precursors in MDS marrow also die from programmed cell death. Such a mechanism may be responsible for the generally slow expansion of the clone in MDS.

Aged↗

PubMed2004

[Bonding strength and interface effects of different dentin surface on acetone-based adhesives bonding].

PURPOSE: To study the influences on microstructure characteristic and bonding strength of acetone-based wet bonding systems when bonding on dry or wet dentin surface. METHODS: Three acetone-based wet bonding systems, Gluma One-Bond, Bond-1 and One-Step, were used to bond Chrisma composite resin to dry or moist dentin surface, and the bonding interface was observed with HITACHI S-2700 scanning electron microscope. Microtensile strengths of different groups were measured with Instro 1195. RESULTS: All three bonding systems can infiltrate well into dentin bonding interface in the wet groups. A hybrid layer of about 5microm could be observed with resin tags traversing from the resin layer above into the undemineralized dentin below and the lateral branch of dentinal tubule. In the dry groups, three zones, a surface and a basal hybrid layer sandwiching a middle hybridoid region, could be observed. The hybrid layer was very thinner. Microtensile strength had significantly decreased while bonding on dry dentin surface with acetone-based wet bonding systems, with the maximum decrease of 39% in Bond-1. CONCLUSION: Incompletely infiltrated adhesive on dentin bonding interface could be observed and microtensile strength had significantly decreased while bonding on dry dentin surface with acetone-based wet bonding systems. Moist dentin surface, which can maintain collagen-rich fibrous network of demineralized dentin, is necessary when bonding with acetone-based wet bonding systems. Microtensile strength approaches to the real dentin bonding strength.

Acetone↗

PubMed2004

[Antitumor research on mouse melanoma with combined application of Newcastle disease virus and its HN gene].

BACKGROUND & OBJECTIVE: Although Newcastle disease virus (NDV) shows antitumor effect on many tumors, its mechanism is unclear. Hemagglutinin-neuraminidase (HN) gene was found to play an important role in NDV antitumor effect and HN protein located on tumor cell surface. This research was to evaluate the possibility of HN protein as a foreign antigen of tumor cell and the antitumor effect of the combined application of HN gene and NDV. METHODS: C57BL/6 mice were subcutaneously inoculated with 2 x 10(5) B16 tumor cells in the right hindlimb. Combination group: on 2nd day post-inoculation, the recombinant plasmid containing HN gene was injected intramuscularly in the left hindlimb; on 7th day post-inoculation, 2 x 10(9) pfu NDV was administrated intratumorally. The alone HN gene group, NDV group, and PBS control group were treated as above. The antitumor effect was observed through tumor suppression rate, the antitumor mechanisms were researched with specific cytotoxic T lymphocyte (CTL) assay, and the expression determination of HN protein, ICAM-I, and CD48 on the B16 tumor cells. RESULTS: The antitumor efficacy of the combined application of NDV and its HN gene increased compared with NDV,and its HN gene alone, the tumor suppression rates were 82.8%, 41.0%, and 56.6%; the specific CTL activity were 18.4%, 10.1%, and 4.4%, respectively. Furthermore, the expression of HN gene had been detected, and the expression of ICAM-I and CD48 were up-regulated on the tumor cells after NDV injection. CONCLUSION: HN protein located on the surface of tumor cells and mediated the specific repulsion to tumor cells; the antitumor efficacy increased after the combined application of NDV and its HN gene.

Animals↗

PubMed2004

[Biologic changes in MDS-L cell line induced by As2O3 and/or TRAIL].

OBJECTIVE: To investigate the biological changes in myelodysplastic syndromes (MDS) myeloid blast cell line MDS-L after different duration and concentration of As2O3/TRAIL (TNF related apoptosis inducing ligand) treatment. METHODS: MDS-L cells were treated with As2O3 and TRAIL at 9 different concentrations and the treated cells were detected at 24 h, 48 h and 72 h for biologic indexes. The same detections were conducted in untreated MDS-L cells and normal and MDS marrow cells as controls. Apoptosis was assayed by flow cytometry after Annexin V-FITC labelling. Differentiation-induction effect of these drugs on the cells were detected by morphologic examination and CD34(+) proportion analysis after 24 hours treatment and further agar culture for 18 days; P15(ink4b) mRNA expression were detected by RT-PCR and its protein expression by DAB immunocytochemistry, P15(ink4b) DNA methylation by methylation specific PCR (Msp). RESULTS: As2O3/TRAIL treatment promoted MDS-L cells to undergo apoptosis and As2O3 plus TRAIL showed obvious differentiation-induction effect on MDS-L. P15(ink4b) mRNA expression was upregulated in MDS-L cell line after different drug treatment but almost no protein expression increased. Increased P15 expression seemed to be related with DNA demethylation effect of these drugs. CONCLUSIONS: As2O3 or/and TRAIL treatment could promote apoptosis of the clonal cells and induce incomplete cell differentiation. The drugs treatment could also increase P15(ink4b) expression in MDS-L cell line through their demethylation effects.

Antigens, CD34↗

PubMed2003

Potential-dependent reorientation of thiocyanate on Au electrodes.

Thiocyanate (SCN) adsorption on an Au electrode is examined using surface-enhanced Raman scattering (SERS) measurements, along with detailed density functional theory (DFT) calculations. Both the calculation and the spectroscopic measurements show that three different geometries are adopted by SCN adsorption in the potential region studied (0.0 V <or= E <or= 1.2 V vs NHE). At low potential both N-bound and S-bound forms are found, at intermediate potentials around the potential of zero charge (E(pzc)) the S-bound form dominates, and at high potentials SCN associates with the Au surface via a bridging geometry. The Stark slope observed for the C-N stretch in the N- and S-bound forms is positive, while the bridge form exhibits a negative Stark slope. DFT calculations show that the potential-dependent reorientation of SCN arises from overlap of specific SCN-based orbitals with the Fermi level of the Au surface; as the Fermi energy changes, different orbital overlaps are found. The calculations also provide an explanation for the different signs of the Stark slope observed for different geometries. For the end-on adsorption, the lowest unoccupied molecular orbital (LUMO) associated with the C-N bond is antibonding, while the corresponding LUMO in the bridge form is bonding.

Journal Article↗

PubMed2003

Peroxide electroreduction on bi-modified Au surfaces: vibrational spectroscopy and density functional calculations.

The mechanism of the electroreduction of peroxide on Bi-submonolayer-modified Au(111) surfaces is examined using surface-enhanced Raman scattering (SERS) measurements along with detailed density functional theory (DFT) calculations. The spectroscopy shows the presence of Bi-OH and Bi-O species at potentials just positive of that where peroxide is reduced. These species are not present in solutions absent either peroxide or Bi. DFT calculations show that peroxide is unstable relative to Bi-OH when Bi is present in the (2 x 2) configuration on Au(111) known from previous work to be catalytically active. The spacing between Bi adatoms is such that peroxide association with two Bi cannot occur without O-O bond cleavage. The full Bi monolayer is catalytically inactive and exhibits none of the Bi-OH or Bi-O signals seen for the active surface. The calculations show that as the Bi coverage becomes greater and the Bi adatom spacing becomes smaller, peroxide can adsorb on Bi without O-O bond rupture. These results indicate an important role for M-OH species in peroxide electroreduction.

Journal Article↗

PubMed2003

[Ovarian carcinoma cell inhibits T cell JAK-STAT signal transduction pathway, an experimental study].

OBJECTIVE: To investigate the effect of ovarian carcinoma cell on T cell JAK-STAT signal transduction pathway and its role in the ovarian carcinoma induced immunosupression. METHODS: Human ovarian carcinoma cells of OVCAR3. CAOV3, and SKOV3 lines were cultured. CD8(+) T cells were isolated from the peripheral venous blood of healthy persons. Then the supernatants of these ovarian carcinoma cell lines and RPMI-1640 were added into the culture of CD8(+) T cells (groups I, II, III, and control). Thiazolyl blue (MTT) method was used to detect the growth of CD8(+) T cell. The cell cycle was examined by flow cytometry. The secretion of the Tc1 type cytokine interferon (IFN)-gamma mRNA and the secretion of the Tc2 type cytokine interleukin (IL)-10 mRNA were detected by RT-PCR. The expression of signaling molecules JAK and JAK3 and the phosphorylated activation of STAT3 and STAT5 in the CD8(+) T cell were analyzed by Western blotting. RESULTS: The absorbance at the wavelength 570 nm of CD8(+) T cell culture was 0.23 +/- 0.03, 0.28 +/- 0.06, and 0.29 +/- 0.05 in the group I, II, and III, all significantly lower than that in the group IV (0.79 +/- 0.07, all P < 0.01). The percentages of CD8(+) T cells at the stage S and stage G(2)/M were lower, and those in stage G(1)/G(0) were higher in groups I, II, and III than in group IV (all P < 0.01). The IFN-gamma expression was significantly lower in groups I, II, and III in comparison with that in group IV. However, the expression of IL-10 was significantly higher in groups I, II, and III in comparison with that in group IV. The expression of JAK3 protein, but not JAK1 protein, was significantly lower in groups I, II, and III in comparison with that in group IV. The phosphorylated activation of STAT5 was suppressed significantly in groups I, II, and III, whereas the phosphorylated activation of STAT3 was suppressed only in group I. CONCLUSION: Ovarian carcinoma may suppress T cell proliferation through inhibition of the JAK-STAT signal transduction pathway, which may be a mechanism of ovarian carcinoma induced immunosuppression.

CD8-Positive T-Lymphocytes↗

PubMed2003

Bioinformatics data distribution and integration via Web Services and XML.

It is widely recognized that exchange, distribution, and integration of biological data are the keys to improve bioinformatics and genome biology in post-genomic era. However, the problem of exchanging and integrating biology data is not solved satisfactorily. The eXtensible Markup Language (XML) is rapidly spreading as an emerging standard for structuring documents to exchange and integrate data on the World Wide Web (WWW). Web service is the next generation of WWW and is founded upon the open standards of W3C (World Wide Web Consortium) and IETF (Internet Engineering Task Force). This paper presents XML and Web Services technologies and their use for an appropriate solution to the problem of bioinformatics data exchange and integration.

Computational Biology↗