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Biomedical subjects

Bo Wang

Publications and source records attributed to Bo Wang.

At least 73 records · Page 4Linked to original sources
PubMed2006

Chitosan-mediated synthesis of gold nanoparticles on patterned poly(dimethylsiloxane) surfaces.

Synthesis of gold nanoparticles on surfaces has been accomplished by the incubation of poly(dimethylsiloxane) (PDMS) films in tetrachloroauric(III) acid and chitosan solution at room temperature and 4 degrees C. One important point in the present study is that the synthesis selectively occurred on the PDMS surface. These observations are substantially different from the reaction in solution, in which no particles can be formed at room temperature. Computation of surface plasmon bands (SPBs) based on Mie theory suggests that the particles are partially coated by chitosan molecules, and the experimental results confirm the theoretical calculations. The proposed mechanism is that chitosan molecules adsorbed or printed on the PDMS surfaces act as reducing/stabilizing agents. Furthermore, PDMS films patterned with chitosan could induce localized synthesis of gold nanoparticles in regions capped with chitosan only. In this way, colloidal patterns were fabricated on the surfaces with high spatial selectivity simultaneously with the synthesis of the particles. Surface-induced fluorescence quenching was observed in the regions capped with gold nanoparticles as well.

Chitosan↗
PubMed2006

Modelling the spread of HIV/AIDS in China: the role of sexual transmission.

The study presented here is an exploration of the implications of patterns of sexual behaviour for the spread of HIV in China, using a bio-behavioural macrosimulation model. To reflect the uncertainty surrounding key parameters, analyses of varied scenarios are used to show a range of possible outcomes consistent with variations in selected biological and behavioural inputs. The latter are estimated from a nationwide survey of sexual behaviour recently conducted in China, a country with an emerging HIV/AIDS epidemic, where it is feared that HIV/AIDS will spread to the general population via heterosexual transmission. The results highlight the primacy of the levels and distribution of sexual activity in the population. They offer some guidelines for understanding and interpreting the potential implications of current and prospective changes in sexual behaviour for the spread of HIV/AIDS in the world's largest population, and also highlight the need to collect better data on sexual behaviour for the estimation of key model inputs.

Adult↗
PubMed2006

Removal of algae by sonication-coagulation.

Algae bloom in source water has caused serious problems in drinking water supplies, and conventional methods for its treatment have achieved only limited success. This paper reports a new technology, ultrasound assisted coagulation, for effective removal of algae cells from the source water in water treatment works. The results showed that ultrasonic pretreatment significantly enhanced the removal efficiency of algae cells. Ultrasonic irradiation for 5 s increased the algae removal efficiency by more than 20% when the coagulant dose was 0.4-0.8 mg/L. To achieve the same algae removal ratio of 90%, sonication for 5 s reduced the coagulant dose by 2/3. The optimal sonication parameters were determined as follows: sonication time of 1 s, ultrasonic power of 48 W, and solution pH of 8-9. The sound frequency had little impact on the algal removal efficiency. Ultrasonic pretreatment also significantly reduced the sample turbidity.

Cyanobacteria↗
PubMed2006

Cytotoxicity of cantharidin analogues targeting protein phosphatase 2A.

Cantharidin is a natural toxin that possesses potent anti-tumor properties. Its clinical application, however, is limited due to severe side-effects. Its cytotoxicity is believed to be mediated by the inhibition of serine/threonine protein phosphatase 2A. In order to identify new compounds with potential clinical therapeutic use, a series of cantharidin analogues, including those with skeletal modifications at 1-C position (analogues 1-6) and those with anhydride modifications (analogues 7-13), were synthesized, and tested for their inhibitory effects on protein phosphatase 2A and their cytotoxicity to a panel of cancer cell lines. In addition, the mode of inhibition of cantharidin and analogue 13 on protein phosphatase 2A was determined by enzymatic kinetics assay. The data indicated that analogue 13 exhibited potent cytotoxicity to all cancer cell lines, and analogues 9, 11 and 12 showed relatively weak cytotoxicity to one or more cell lines, while other analogues showed little cytotoxicity. Accordingly, analogue 13 exhibited potent inhibitory activity on protein phosphatase 2A, and analogues 9, 11 and 12 showed weak inhibitory activity, while other analogues did not show any inhibitory activity. The findings indicate that the cytotoxicity of synthetic cantharidin analogues is likely to be associated with their protein phosphatase 2A inhibitory activity. The mode of inhibition of cantharidin and analogue 13 on protein phosphatase 2A is identified as noncompetitive inhibition by the Lineweaver-Burk plot.

Cantharidin↗
PubMed2006

Men who have sex with men and human immunodeficiency virus/sexually transmitted disease control in China.

OBJECTIVES: To address the role of men who have sex with men (MSM) in the human immunodeficiency virus (HIV)/sexually transmitted disease (STD) epidemic in China. GOAL: To explore the prevalence of risky sexual behaviors and the existing prevention efforts among men who have sex with men (MSM) in China. STUDY DESIGN: Review of behavioral and STD/HIV prevention studies addressing MSM in China. RESULTS: Sexual risk behaviors including unprotected group sex, anal sex, casual sex, and commercial sex were prevalent among Chinese MSM. Many Chinese MSM also engaged in unprotected sex with both men and women. Most MSM either did not perceive that they were at risk of HIV/AIDS or underestimated their risk of infection. Surveillance and intervention research among these men are still in the preliminary stages. CONCLUSIONS: Chinese MSM are at risk for HIV/STD infection and potential transmission of HIV to the general population. In addition to sexual risk reduction among MSM, reduction of homosexuality- related stigma should be part of effective intervention efforts. Volunteers from the MSM community and health care workers in primary health care system may serve as valuable resources for HIV/STD prevention and control among MSM.

China↗
PubMed2006

Polarization-dependent Talbot effect.

The term "polarization-dependent Talbot effect" means that the Talbot self-imaging intensity of a high-density grating is different for TE and TM polarization modes. Numerical simulations with the finite-difference time-domain method show that the polarization dependence of the Talbot images is obvious for gratings with period d between 2 lambda and 3 lambda. Such a polarization-dependent difference for TE and TM polarization of a high-density grating of 630 lines/mm (corresponding to d/lambda=2.5) is verified through experiments with the scanning near-field optical microscopy technique, in which a He-Ne laser is used as its polarization is changed from the TE mode to the TM mode. The polarization-dependent Talbot effect should help us to understand more clearly the diffraction behavior of a high-density grating in nano-optics and contribute to wide application of the Talbot effect.

Journal Article↗
PubMed2006

Short-term effect of a cultural adaptation of voluntary counseling and testing among female sex workers in China: a quasi-experimental trial.

This study evaluates the efficacy of cultural adaptation of a voluntary counseling and testing (VCT) intervention, in increasing condom use and decreasing rates of sexually transmitted diseases (STDs) among a group of female sex workers (FSWs) in Guangxi, China. This intervention is modeled after the "state-of-the-science" VCT program that was developed and evaluated by the Center for Disease Control and Prevention's Project RESPECT. Four hundred FSWs were assigned to either an intervention group receiving the VCT intervention or a control group receiving standard of care STD testing and treatment. Data were collected at baseline and 6 months postintervention. Outcome measures included HIV/STD related knowledge and perceptions, condom use, and history of STDs. Five common STDs were screened and tested through clinical examination and laboratory testing to serve as biomarkers. After controlling for potential confounders and baseline differences, the VCT intervention group was significantly higher than the control group in HIV/STD related knowledge (p < .0001) and consistent condom use with clients (odds ration [OR] = 2.23; 95% confidence interval [CI] = 1.26-3.96) at 6 months follow-up. In addition, the intervention group had a significantly lower infection rate of STDs than the control group at follow-up (OR = 0.44; 95% CI = 0.24-0.80). This quasi-experimental trial provides evidence that the brief VCT intervention, through appropriate cultural adaptation, can be efficacious in increasing condom use and reducing STD infection rate among FSWs in China.

Adult↗
PubMed2006

[Interactions of ovarian carcinoma cells and human peritoneal mesothelial cells involved in matrix metalloproteinases expressions of ovarian carcinoma cells].

OBJECTIVE: To investigate the interactions of ovarian carcinoma cells and human peritoneal mesothelial cells (HPMC) involved in matrix metalloproteinases (MMP) expressions of ovarian carcinoma cells. METHODS: The conditioned medium (CM) of ovarian carcinoma cell SKOV3 was tested by enzyme-linked immunosorbent assay (ELISA) for transforming growth factor beta1 (TGF-beta1). The impact of SKOV3-CM in the presence or absence of TGF-beta1 neutralizing antibody on fibronectin (Fn) gene expression of HPMC was studied by RT-PCR. HPMC were pretreated with serum-free medium, SKOV3-CM, SKOV3-CM + TGF-beta1 neutralizing antibody, and SKOV3-CM + IgG, then the supernatant was collected as HPMC-CM(1), HPMC-CM(2), HPMC-CM(3) and HPMC-CM(4). SKOV3 were incubated with different HPMC-CM, HPMC-CM(1) + antibody against Fn or HPMC-CM(1) + IgG. MMP-2 and MMP-9 gene mRNA expressions and protein expressions of SKOV3 were detected by RT-PCR and ELISA respectively. RESULTS: TGF-beta1 in SKOV3-CM was (236 +/- 22) ng/L. Fn gene mRNA expressions of HPMC before and after stimulation by SKOV3-CM were 1.328 +/- 0.025 and 2.643 +/- 0.051, and the latter was higher than the former (P < 0.05). Fn gene mRNA expressions of HPMC stimulated by SKOV3-CM + TGF-beta1 neutralizing antibody was 1.897 +/- 0.035, which was less than that of SKOV3-CM group (P < 0.01). Before SKOV3 were incubated with HPMC-CM, MMP-9 protein and mRNA expressions were (14.5 +/- 1.6) microg/L and 1.50 +/- 0.04, but protein and mRNA expressions of MMP-2 were scarcely detected. When SKOV3 were incubated with HPMC-CM(1), mRNA expressions of MMP-2 and MMP-9 were 0.226 +/- 0.012 and 2.66 +/- 0.07, protein expressions were (15.0 +/- 0.8) and (37.2 +/- 3.5) microg/L, which were all higher than those of SKOV3 without treatment of HPMC-CM (P < 0.01). Following incubation of SKOV3 with HPMC-CM(1) + antibody against Fn, mRNA expressions of MMP-2 and MMP-9 were 0.138 +/- 0.007 and 1.82 +/- 0.06, protein expressions were (8.8 +/- 0.7) and (25.8 +/- 2.5) microg/L, which decreased compared with those of HPMC-CM(1) group (P < 0.01). Following incubation of SKOV3 with HPMC-CM(2), mRNA expressions of MMP-2 and MMP-9 were 0.467 +/- 0.018 and 4.28 +/- 0.09, protein expressions were (39.3 +/- 3.6) and (62.0 +/- 5.3) microg/L, which were higher than those of HPMC-CM(1) group (P < 0.01). Following incubation of SKOV3 with HPMC-CM(3), gene expressions of MMP-2 and MMP-9 were 0.331 +/- 0.015 and 3.52 +/- 0.08, protein expressions were (27.6 +/- 1.9) and (50.0 +/- 4.1) microg/L, which decreased compared with HPMC-CM(2) group (P < 0.05), but were still higher than those of HPMC-CM(1) group (P < 0.05). CONCLUSIONS: Ovarian carcinoma cells activate HPMC through TGF-beta1, which induces higher expressions of MMP of ovarian carcinoma cells. Up-regulating Fn expression of HPMC may be one of action mechanisms of ovarian tumor cells. Fn derived from HPMC stimulates MMP-2 and MMP-9 expressions of ovarian carcinoma cells at gene and protein levels.

Antibodies↗
PubMed2006

[Significance of EGFR and p-ERK expression in nasopharyngeal carcinoma].

OBJECTIVE: To detect the expression of EGFR and p-ERK in nasopharyngeal carcinoma (NPC) and investigate their clinical significance. METHODS: Immunohistochemistry LSAB method was adopted to detect the expression of EGFR and p-ERK. Statistical analysis was performed using SPSS statistical software package (10.0) to correlate their expression with clinical characteristics and prognosis. RESULTS: Positive staining for EGFR was observed in 39 of 55 cases (70.9%). The EGFR expression was correlated with clinical stage and gender. EGFR expression was correlated with poorer overall survival (OS) and shorter time to progression (TTP). Positive staining for p-ERK was observed in 29 of 55 cases (52.7%). There was a statistically significant association between positive p-ERK expression and advanced clinical stage. Positive p-ERK expression was correlated with poorer OS, disease-free survival (DFS) and TTP. EGFR expression was correlated with the expression of p-ERK. On multivariate analysis, age over 50 years was an independent poor prognostic factor for NPC. Both EGFR and p-ERK were not independent prognostic factors for NPC. CONCLUSION: Expressions of EGFR and p-ERK are detected in NPC. Their abnormally high expression signifies poor prognosis in NPC patients.

Age Factors↗
PubMed2006

[Testing of anisotropic modulus and fluid characteristic of Chinese femur and tibia].

The tension moduls and compression modulus of Chinese tibia and femur of male in three different directions, namely axial, circumferential and radial directions, were tested in our experiments. The measured compression moduli are 5.8 +/- 0.34, 3.4 +/- 0.17, 2.1 +/- 0.18 GPa respectively for femur, and 6.1 +/- 0.36, 3.5 +/- 0.17, 2.1 +/- 0.18 GPa respectively for tibia; the measured tension moduli are 15.6 +/- 1.21, 9.8 +/- 0.73, 5.4 +/- 0.52 GPa respectively for femur, and 16.7 +/- 1.09, 10.3 +/- 0.70, 5.6 +/- 0.49 GPa respectively for tibia. The tension and compression ultimate strengths of femur and tibia were tested, too. The measured compression ultimate strengths are 150 +/- 9.3, 111 +/- 6.5, 110 +/- 7.1 MPa respectively for femur, and 191 +/- 12.3, 140 +/- 6.3, 123 +/- 8.3 MPa respectively for tibia; the measured tension ultimate strengths are 115 +/- 9.6, 82 +/- 6.8, 78 +/- 7.3 MPa respectively for femur, and 143 +/- 8.7, 110 +/- 8.3, 97 +/- 6.4 MPa respectively for tibia. Furthermore, the stress-relaxation experiments were conducted. The relation between loading and time during the experiments were obtained by the method of curve fitting. They meet the logarithm function: F = A * B(log t); A is the initial load, and B is the fitting material parameter. For femur, B is equal to 0.985; for tibia, B is equal to 0.987.

Anisotropy↗
PubMed2006

[Photodynamic effect of hematoporphyrin monomethyl ether on ovarian cancer cell line SKOV3].

BACKGROUND & OBJECTIVE: Photodynamic therapy (PDT) is a new treatment choice for ovarian carcinoma. Hematoporphyrin monomethyl ether (HMME) is a novel photosensitive reagent developed in China. This study was to investigate the photodynamic effect of HMME-based PDT on human epithelial ovarian cancer cell line SKOV3. METHODS: After an incubation with 30 microg/ml HMME for different time, the fluorescent image and intracellular location of HMME in SKOV3 cells were observed under a fluorescent microscope and laser scanning confocal microscope (LSCM). After being treated with different doses (5-50 microg/ml) of HMME and irradiated with different optical doses (1.5-12 J/cm(2)) of laser, the survival rate of SKOV3 cells was measured by MTT assay. Mechanisms of cell death during PDT was determined by Annexin V/PI double staining technique and analyzed by flow cytometry. RESULTS: Red fluorescence appeared shortly after administration of HMME and localized in cytoplasm; intracellular fluorescence intensity reached the peak after 3 h. High concentrations of HMME alone had cytotoxicity to SKOV3 cells, while laser irradiation alone had no effect on cell survival. Survival rate of SKOV3 cells was gradually decreased along with the increase of HMME concentration and laser dose, but such a trend diminished when HMME concentration reached 40 microg/ml. After treatment of HMME, the dead cells were predominantly necrosis cells. CONCLUSION: HMME has a photodynamic effect on SKOV3 cells.

Cell Line, Tumor↗
PubMed2006

[Feasibility study of application of international prognostic score on prediction of prognosis for advanced Hodgkin's lymphoma].

BACKGROUND & OBJECTIVE: Currently, 60% patients with advanced Hodgkin's lymphoma could be cured by receiving standard treatments. The international prognostic factor project on advanced Hodgkin's lymphoma has developed a concept of international prognostic score (IPS) based on seven adverse prognostic factors consisting of male sex, age 45 years or older, stage IV disease, leukocytosis, lymphocytopenia, low hemoglobin and low serum albumin for newly diagnosed advanced Hodgkin's lymphoma patients. This study was to explore the feasibility of the international prognostic score in advanced Hodgkin's lymphoma. METHODS: We performed a retrospective review of 141 patients with untreated advanced Hodgkin's lymphoma in Cancer Center of Sun Yat-sen University between January 1980 and December 2004. IPS was defined as the number of adverse prognostic factors presented at diagnosis. The rates of failure free survival (FFS) and overall survival (OS) were estimated using the method of Kaplan-Meier and compared according to IPS by log-rank test. Cox proportional hazard model was used in multivariate analysis. RESULTS: The 5-year FFS and OS for 141 advanced Hodgkin's lymphoma patients were 57.6%, 68.1% respectively. Estimated 5-year FFS was 67.7%, 63.2%, 61.8%, 34.9% for patients with 0-1, 2, 3, > or =4 of the adverse prognostic factors respectively. Estimated 5-year OS was 81.0%, 75.5%, 70.3%, 42.3% for patients with 0-1, 2, 3, > or =4 of the adverse prognostic factors respectively. The 5-year FFS for low risk patients with IPS=0-2 and high risk patients with IPS> or =3 were 65.4%, 48.9% respectively (log-rank test: P=0.012); the 5 year OS for patients with IPS=0-2 and IPS> or =3 were 78.4%, 57.1% respectively (log-rank test: P=0.004). Low risk patients with IPS=0-2 had superior overall survival than high risk patients with IPS> or =3 when treated with ABVD or MOPP. The FFS and OS of the advanced HL patients at high risk treated with ABVD were better than those treated with MOPP. Multivariate analysis demonstrated that B symptoms, extranodal disease and MOPP chemotherapy were independent adverse prognostic factors for FFS and OS. CONCLUSIONS: The IPS shows good prognostic power in advanced HL. High risk advanced HL patients treated with MOPP have inferior survival than those treated with ABVD, thus we recommend patients to be treated with ABVD or more intensive regimen.

Adolescent↗
PubMed2006

[Studies on chemical constituents from moss Rhodobryum roseum II].

OBJECTIVE: To study the chemical constituents from Rhodobryum roseum. METHOD: The compounds were isolated and purified by recrystallization and chromatography with silica gel and sephadex LH-20 column. Their structures were identified by physicochemical properties and spectral analysis. RESULT: Eight compounds were isolated and identified as apigenin (1), quercetin (2), oleanolic acid (3), 2alpha-hydroxyoleanolic acid (4), 2alpha-hydroxyursolic acid (5), protocatechuic acid (6), p-hydroxybenzoic acid (7), p-hydroxycinnamic acid (8). CONCLUSION: Compounds 1-8 were isolated from R. roseum for the first time.

Apigenin↗
PubMed2006

[Protective and reverse effects of qindan capsule on aortic lesion in spontaneously hypertensive rats].

OBJECTIVE: To investigate the effects and mechanism of Qindan Capsule (QC) on aortic structure in spontaneously hypertensive rats (SHR). METHODS: Thirty-two SHR of 14 weeks old, were divided into the QC group, the Niuhuang Jiangya Capsule (NJC) group, the captopril group and the model group. Besides, Wistar-Kyoto (WKY) rats were taken as the normal control. All the others were administered with corresponding medicine and their blood pressure measured. After 12 weeks, the morphological changes of aorta were observed by HE and Masson staining, the level of angiotensin II (Ang II) in aorta was detected by radioimmunoassay, and the mRNA expression of basic fibroblast growth factor (bFGF) in aortic wall was analyzed by real-time quantitative fluorescent PCR. RESULTS: QC could reduce the blood pressure in SHR, improve their aortic structure, lower the Ang II level and inhibit the bFGF mRNA expression in aortic wall (P < 0.05 or P < 0.01), showing a good effect similar to that of captopril (P > 0.05) and better than that of NJC (P < 0.01). CONCLUSION: QC has a significant protective and reverse effect on aortic lesion in SHR. The mechanism may be related to its actions in reducing Ang II level and inhibiting bFGF mRNA expresion in aortic wall.

Angiotensin II↗
PubMed2006

[Spatial variability of farmland heavy metals contents in Qianan City].

By the methods of geostatistics and GIS, this paper studied the spatial variability of Cu, Zn, Ni, Cr As, Hg, Cd and Pb contents in the farmland topsoil (0 -20 cm) of Qianan City, Hebei Province. The results showed that the average contents of test metals were under the secondary standard of environmental quality standard for soil (GB 15618-1995), and belonged to moderate variability. The theoretical models of semi-variance of Cu, Zn, Ni, Cr and As contents fitted exponential models, and their spatial correlations were strongly spatial dependence; while the theoretical models of Hg and Cd contents fitted spherical models, and their spatial correlations were moderately spatial dependence. The Pb content had pure nugget effect, and was weakly spatial dependence. In whole research scale, Pb content had lasting variability, while the other seven heavy metals contents had the spatial variability mainly caused by their spatial correlation parts. The ranges of heavy metals spatial correlations were about 11 km to 20 km. The Kriging' s interpolation of Cu, Zn, Ni, Cr, Hg, As and Cd contents showed that their contents were higher in northern mountainous area, but lower in mid basin.

China↗
PubMed2006

[Detection of formaldehyde induced developmental toxicity assessed with single cell gel electrophoresis].

To understand the developmental toxicity and the maternal toxicity of formaldehyde (FA), pregnant mice were injected celiac with FA, from the 6th day to the 19th day after the pregnancy. After the birth of fetal mice, the single cell gel electrophoresis (SCGE) was applied to test the DNA damage in liver cells of the maternal mice and of the fetal mice. The experimental results obtained from fetal mice indicate that FA does not induce DNA damage at the low concentration (0.2 mg/kg, P > 0.05), while it could induce DNA breakage at higher concentration as 1.0 mg/kg (P < 0.01). Moreover, DPC(DNA-protein crosslinks) was also initiated at the concentration as 2.0 mg/kg (P > 0.05). When the concentration was up to 20.0 mg/kg, almost all of the DNA is completely joined to form DPC (P > 0.05). The experimental results of pregnant mice indicate that DNA breakage could initiate at relatively low concentration (0.2 mg/kg). Meanwhile, the damage effect was obviously enhanced with the increasing of concentrations (1.0 mg/kg, P < 0.01; 2.0 mg/kg, P < 0.01; 20.0 mg/kg, P < 0.01). No significant increase in DPC formation was observed in pregnant mice, indicating that of all the concentrations of FA tested in the experiment, the DNA damage mainly attributes to DNA breakage. These results suggested that FA has both the maternal toxicity and the developmental toxicity.

Animals↗