A trade-off between antifouling and the electrochemical stabilities of PEDOTs.

Strong nonspecific protein/cell adhesion on conducting polymer (CP)-based bioelectronic devices can cause an increase in the impedance or the malfunction of the devices. Incorporating oligo(ethylene glycol) or zwitterionic functionalities with CPs has demonstrated superior performance in the reduction of nonspecific adhesion. However, there is no report on the evaluation of the antifouling stability of oligo(ethylene glycol) and zwitterion-functionalized CPs under electrical stimulation as a simulation of the real situation of device operation. Moreover, there is a lack of understanding of the correlation between the molecular structure of antifouling CPs and the antifouling and electrochemical stabilities of the CP-based electrodes. To address the aforementioned issue, we fabricated a platform with antifouling poly(3,4-ethylenedioxythiophene) (PEDOT) featuring tri(ethylene glycol), tetra(ethylene glycol), sulfobetaine, or phosphorylcholine (PEDOT-PC) to evaluate the stability of the antifouling/electrochemical properties of antifouling PEDOTs before and after electrical stimulation. The results reveal that the PEDOT-PC electrode not only exhibits good electrochemical stability, low impedance, and small voltage excursion, but also shows excellent resistance toward proteins and HAPI microglial cells, as a cell model of inflammation, after the electrical stimulation. The stable antifouling/electrochemical properties of zwitterionic PEDOT-PC may aid its diverse applications in bioelectronic devices in the future.

Tunable Protein/Cell Binding and Interaction with Neurite Outgrowth of Low-Impedance Zwitterionic PEDOTs.

Zwitterionic poly(3,4-ethylenedioxythiophene) (PEDOT) is an effective electronic material for bioelectronics because it exhibits efficient electrical trade-off and diminishes immune response. To promote the use of zwitterionic PEDOTs in bioelectronic devices, especially for cell alignment control and close electrocoupling, features such as tunable interaction of PEDOTs with proteins/cells and spatially modulating cell behavior are required. However, there is a lack of reliable methods to assemble zwitterionic EDOTs with other functionalized EDOT materials, having different polarities and oxidation potentials, to prepare PEDOTs with the aforementioned surface properties. In this study, we have developed a surfactant-assisted electropolymerization to assemble phosphorylcholine (PC)-functionalized EDOT with other functionalized EDOTs. By adjusting compositions, the interaction of PEDOT copolymers with proteins/cells can be finely tuned; the composition adjustment has an ignorable influence on the impedance of the copolymers. We also demonstrate that the cell-repulsive force generated from PC can spatially guide the neurite outgrowth to form a neuron network at single-cell resolution and greatly enhance the neurite outgrowth by 179%, which is significantly more distinctive than the reported topography effect. We expect that the derived tunable protein/cell interaction and the PC-induced repulsive guidance for the neurite outgrowth can make low-impedance zwitterionic PEDOTs more useful in bioelectronics.

Approaches to the evaluation of malaria elimination at county level: case study in the Yangtze River Delta region.

As the progress on transition from malaria control to malaria elimination in the People's Republic of China (P.R. China), four counties/districts, namely Zhabei District and Songjiang District of Shanghai municipality, and Anji County and Haiyan County of Zhejiang Province, representatives of the Yangtze River Delta region, were included in the pilot project of the national malaria elimination programme in P.R. China. A baseline survey was conducted first. The main measures performed were blood examination of febrile cases, improving the information management system of malaria cases, providing standard diagnosis and treatment, standardized disposal of epidemic focus, and health education and health promotion, strengthening the management of mobile population, etc. All the measures were assessed and evaluated through data examination and on-site investigation. In the whole process of the pilot project, quality control was especially emphasized. During the implementation of pilot project, the three-level control system was improved, professional staff was enriched and the working fund was ensured (a total fund of RMB 2,923,600). Thirty-nine training courses were conducted. Among 102,451 febrile cases receiving blood examination, all of the 23 malaria cases were confirmed as imported from other provinces or foreign countries. All the epidemic foci were surveyed and some control measures were carried out. Various health education and promotion activities were carried out including publicizing malaria control knowledge through news media, newspapers and periodicals and networks. Assessment and evaluation of the project was done by the Zhejiang and Shanghai Government, comprehensive score was >95 points under the evaluation system which indicated all four pilot counties/districts had first achieved the goal of elimination of malaria in P.R. China. Experiences and lessons about the measures carried out in the project were discussed.

[Prevalence and risk factors on the resistance related to second-line drugs among multi-drug resistant tuberculosis cases in Shanghai, China].

OBJECTIVE: To determine the prevalence and risk factors on second-line drug resistance in patients with multidrug resistant tuberculosis (MDR-TB) in Shanghai, China. METHODS: All pulmonary TB patients with sputum culture positivity detected in Shanghai during January to December, 2009, were enrolled. All of the pretreatment sputum-positive cultures samples were tested for routine specimen identification and routine drug susceptibility testing for first-line drugs (Isoniazid, Rifampin, Ethambutol and Streptomycin). Drug susceptibility testing on second-line anti-TB drugs (Ofloxacin, Amikacin, Kanamycin, Capreomycin, P-aminosalicylic acid and Prothionamide) was routinely performed on isolates of Mycobacterium (M.) TB with MDR. Logistic regression analysis was conducted to determine the risk factors regarding second-line drug resistance. RESULTS: A total of 1867 patients infected with M. TB isolates were diagnosed at the TB hospitals/clinics in Shanghai during the study period, of whom 112 (6.0%) were MDR-TB, in which 58 cases (51.8%) showed resistant to at least one of the second-line drugs tested and 10 cases belonged to extensively drug-resistant. In the multivariate analyses, MDR-TB patients who were aged 45 - 59 years (aOR = 4.76, P = 0.001), with sputum smear positivity (aOR = 6.51, P = 0.026) were significantly more likely to show resistance to second-line drugs. CONCLUSION: The prevalence of second-line drug resistance among MDR-TB patients was high in Shanghai. MDR-TB patients who were under age of 45 - 59 years and with sputum smear positivity would represent important common risk factors for the resistance to second-line drugs.

[The prevalence of hepatitis C virus (HCV) subtypes in Chinese HIV-1/HCV co-infected individuals].

OBJECTIVE: To better understand the prevalence and geographic distribution of genotypes/subtypes on HCV and the relationship between HCV genotypes/subtypes and HIV infection disease progression in the HIV-1/HCV co-infected individuals living in high HIV-1 prevalent areas in China. METHODS: 186 plasma samples were collected from HIV-1 seropositive individuals infected through paid blood donors (PBD), injecting drug users(IDUs) or sexual contact, living in most severely affected provinces, Henan, Yunnan, Xinjiang, Jilin and Liaoning provinces. Samples with HCV viral load >1000 cop/ml were amplified by RT-nested PCR, sequenced and phylogenetically analyzed for genotyping/subtyping of HCV. HIV-1, HCV viral loads and CD4+ T lymphocytes were measured for all subjects. RESULTS: (1) HCV were identified as 1a (1.7%), 1b (39.9%), 2a (17.9%), 3a (10.4%), 3b (15.6%), 6a (1.2%), 6n (6.4%), and a newly unclassified subtype (7.5%). HCV 2a and 1b subtypes predominated in PBD in Henan, 3a and 3b in IDUs in Xinjiang and Yunnan, and 6 genotype/subtypes in IDU in Yunnan. (2) There were no significant differences in CD4+ T cell counts among the different HCV subtypes. (3) The viral load of HCV RNA in 1b subtype was higher than that of non-1b subtype, however, no significant differences in HIV-1 viral loads and CD4+ T cell counts were found between 1b and non-lb subtype. Both HIV and HCV viral loads were lower in 2a than non-2a subtype. CONCLUSION: The prevalence of HCV genotype/subtype in HIV-1/HCV co-infected individuals was associated with geographic areas and transmission routes. HCV subtypes had no direct correlation with HIV infection disease progression.

[Frequency of the CD4+CD25nt/hiCD127lo regulatory T lymphocytes from the peripheral blood in Chinese healthy individuals].

AIM: To determine the frequency of the CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes from the peripheral blood in the Chinese healthy individuals and provide some useful evidence for clinical research of correlative diseases. METHODS: From the CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes of peripheral blood in 312 Chinese healthy male and female individuals aged from 8 to 60(five age groups were collected) The expression of transcription factor Foxp3 was detected by triplex immuno fluorescence and the frequency of CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes was determined by flow cytometry. RESULTS: The frequency of CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes in Chinese healthy individuals was (6.55+/-0.11)%, and the frequency differed among age groups(P=0.015) and sex groups(P<0.05). CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes specifically express transcription factor Foxp3. CONCLUSION: The frequency of the CD4(+)CD25(nt/hi)CD127(lo) regulatory T lymphocytes from the peripheral blood in the Chinese healthy individuals has been preliminarily determined which lays the foundation for further clinical research of regulatory T lymphocytes. As a specific cell surface marker, CD25(nt/hi)CD127(lo) can helpful obtain pure CD4(+)CD25(+) regulatory T lymphocytes and suppress the interference of other cells during cell separation.

The influence of social and sexual networks in the spread of HIV and syphilis among men who have sex with men in Shanghai, China.

OBJECTIVES: To analyze characteristics of social and sexual networks and their role as risk factors for HIV and syphilis among men who have sex with men (MSM) in Shanghai, China. DESIGN: : A cross-sectional study. METHODS: We recruited 477 participants using a snowball sampling method. We administered a face-to-face questionnaire and provided testing and counseling for HIV and syphilis. RESULTS: The prevalences of HIV and markers for syphilis were 1.47% (95% confidence interval [CI]: 0.59 to 3.01) and 13.47% (95% CI: 10.53 to 16.88), respectively. The independent factors associated with lower risk for syphilis infection were having a contact network, overlap of social and sexual networks, meeting other MSM at the gym or through the Internet, having 3 to 5 lifetime male anal sex partners, and having a female steady sex partner. A larger male sexual network size, having been married, being more knowledgeable about HIV, having 6 or more lifetime male anal sex partners, and having steady male or female sex partners were independently associated with having unprotected anal or vaginal intercourse. CONCLUSIONS: Significant associations were found between network characteristics and syphilis infection and unprotected sex. Network-based interventions should be developed to reduce this HIV risk among MSM in China.

[Study on using the multiplier method in estimating the size of men who have sex with men population in Shanghai].

OBJECTIVE: To estimate the size of men who have sex with men (MSM) in Shanghai. METHODS: Multiplier method was used in the study and two popular Shanghai-based MSM websites were selected as targeted institutions. The number of MSM (r) who visited website during a given period was investigated by a web-based questionnaire. Meanwhile, a survey was conducted among MSM living in Shanghai to obtain the proportion of MSM who had visited the websites during the given period, the reciprocal number of this proportion was the multiplier (m), therefore, population size can be estimated by r multiplied by m. RESULTS: The MSM population was estimated as 398 433 when website A was selected as target institution and 370 755 was estimated when website B was selected. The estimated population of MSM accounted for 7.1% and 6.6% of male population aged 15 to 49 years old in Shanghai, respectively. CONCLUSION: It was feasible to use multiplier method which selecting MSM website as target institution to estimate the size of MSM population, however, the representativeness of this study sample should be considered seriously.

[Antitumor and anti-angiogenic effects of manumycin on human hepatocellular carcinoma HepG2 xenografts in nude mice].

BACKGROUND & OBJECTIVE: Farnesyl-transferase inhibitor manumycin has in vitro and in vivo antitumor effects on pancreatic cancer, colon cancer, and anaplastic thyroid carcinoma. Our previous experiments showed that manumycin could inhibit proliferation pathway and survival pathway in human hepatocellular carcinoma HepG2 cells in vitro. This study was to examine the antitumor and anti-angiogenic effects of manumycin on HepG2 xenografts in nude mice. METHODS: The xenografts derived from HepG2 cells were established in BALB/C nude mice. Inoculated mice were randomly divided into normal saline (NS) group, positive control (cyclophosphamide, CTX, 25 mg/kg) group, negative control (0.1% Me2SO, 20 ml/kg) group, low dose munumycin (2.5 mg/kg) group, and high dose munumycin (5 mg/kg) group. Tumor volume was measured in nude mice bearing xenografts. Microvessel density (MVD) was observed by immunohistochemistry. Protein levels of vascular endothelial growth factor (VEGF) and b-fibroblast growth factor (b-FGF) were determined by Western blot; mRNA level of VEGF was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The mean tumor volume ratio of nude mice xenograft (V/V(0)) was significantly lower in low dose manumycin group and high dose manumycin group than in negative control group (0.68+/-0.09 and 0.59+/-0.04 vs. 1.38+/-0.21, P < 0.01). MVD was significantly lower in manumycin-treated groups than in control group (P < 0.01). Manumycin significantly down-regulated protein level of VEGF in HepG2 cells and HepG2 xenografts, and mRNA level of VEGF in HepG2 xenografts, but didn't affect protein level of b-FGF. CONCLUSIONS: Manumycin could inhibit the growth of human hepatocellular carcinoma HepG2 xenografts in nude mice. The down-regulation of VEGF expression and the inhibition of angiogenesis might play a key role in the anti-neoplastic effect of manumycin.

Manumycin induces apoptosis in human hepatocellular carcinoma HepG2 cells.

Farnesyltransferase inhibitors (FTIs) were developed to prevent Ras processing and thus to be effective agents for the treatment of cancers harbouring mutated ras. In the present study, HepG2 cells underwent internucleosomal DNA fragmentation after treatment with farnesyltransferase inhibitor manumycin (20 microM) for 12 h. Flow cytometric analysis showed that HepG2 cells were accumulated in the G2/M phase of the cell cycle and the number of apoptotic sub-G1 fraction of cells was increased after treatment with manumycin in a time-dependent manner. During the induction of apoptosis, expression of p53 and p21WAF1 was upregulated, phosphorylation of IkappaB-alpha was blocked, caspase substrates poly(ADP-ribose) polymerase (PARP) and lamin B were cleaved, and Bcl-2 and Bax protein expression remained unchanged. These results indicated that manumycin induced apoptosis in HepG2 cells. The induction of apoptosis by manumycin involved the upregulation of p53 and p21WAF1, the activation of caspases, and the inhibition of nuclear factor-kappaB (NF-kappaB) pathway. However, Bcl-2 and Bax are not associated with manumycin-mediated apoptosis.

Experimental chemotherapy against xenografts derived from multidrug resistant KBv200 cells and parental drug-sensitive KB cells in nude mice by annonaceous acetogenin 89-2.

AIM: Annonaceous acetogenin 89-2 was obtained from atemoya plant. To investigate the effect of 89-2 on experimental chemotherapy against xenografts derived from multidrug resistant KBv200 cells and parental drug-sensitive KB cells. METHODS: Cytotoxicity was determined by tetrazolium (MTT) assay. The models of KB and KBv200 xenografts in nude mice were established to investigate the effect of 89-2 on experimental chemotherapy against cancer in vivo. Mechanistic experiments were conducted to examine the function of P-gp by Fura 2-AM assay. RESULTS: The compound 89-2 showed potent cytotoxicity in KBv200 and KB cells, and the mean IC50 of 89-2 to KBv200 and KB cells was 48.7 and 64.6 nmol.L-1, respectively. The IC50 of 89-2 to multidrug resistant (MDR) cells was similar to that to the parental drug-sensitive cells (P < 0.05). In the models of KBv200 and KB cell xenografts in nude mice, 89-2 (0.90 mg.kg-1, q2d x 6) exhibited 52.3% and 56.5% in inhibiting the growth of xenografts, respectively. The toxicity was endurable. The intracellular accumulation of Fura-2 in KBv200 cells increased to 1.66, 2.03, and 2.74-fold, respectively, by addition of 12.8, 64 and 320 nmol.L-1 of 89-2. CONCLUSION: Both MDR KBv200 cells and parental drug-sensitive KB cells were sensitive to the treatment of 89-2 in vitro and in vivo. The mechanism of overcoming MDR was associated with the decrease of P-gp function MDR cells.

Manumycin inhibits cell proliferation and the Ras signal transduction pathway in human hepatocellular carcinoma cells.

Manumycin was reported to have inhibitory effect on farnesyltransferase by competing with the farnesyl pyrophosphate substrate. It exhibited different antiproliferative activity in human hepatocellular carcinoma HepG2 cells, primary cultured human cardiac muscle cells and human liver cells (CLC). HepG2 cells overexpressing ras gene were more sensitive to manumycin than the other cells. The difference might be related to Ras protein levels in these cell lines. Manumycin reduced the amount of functional ras localized at the cytoplasmic membrane, resulting in blocked C-raf-1 assocation with Ras. Manumycin inhibited ERK1/2 phosphorylation in HepG2 cells without reduced expression of ERK1/2 protein. The levels of protein MKP-1 were significantly up-regulated. Our study also demonstrated that manumycin inhibited p85/PI3K and Akt phosphorylation without reduced expression of p85/PI3K and Akt, and interfered with the association of p85/PI3K and Ras. These findings indicated that manumycin interfered with Ras membrane localization, shut down the downstream pathways of Ras and inhibited cell proliferation in HepG2 cells.

[Experimental studies on treatment of nasopharyngeal carcinoma with combination regimen of hydroxycamptothecin and etoposide].

BACKGROUND & OBJECTIVE: Many studies showed that there is complementary effect between topoisomerase I inhibitor and topoisomerase II inhibitor. Combination of them showed synergistic action. This study was designed to investigate the experimental therapeutic effect of the combination of topoisomerase I inhibitor hydroxycamptothecin (HCPT) with topoisomerase II inhibitor etoposide (VP-16) on nasopharyngeal carcinoma (NPC), the effect of the combination of HCPT with VP-16 against NPC was studied in vitro and in vivo. METHODS: Cytotoxicity of HCPT alone, VP-16 alone, and combination of HCPT and VP-16 on NPC cell strain CNE2 were measured by MTT assay. The models of nude mice xenografts were established for investigating the effect of the combination regimen against NPC in vivo. RESULTS: HCPT alone and VP-16 alone have potent cytotoxicity to CNE2 cells. The IC(50) values were 13.5+/-1.2 micromol/L and 13.5+/-1.0 micromol/L, respectively. The combination of HCPT with VP-16 (1:1) showed synergistic cytotoxicity to CNE2 cells in vitro (CI< 1). In vivo experiment showed that HCPT alone (1.5 mg/kg, i.p., q2d) exhibited 13.6% inhibition growth rate;VP-16 alone (10 mg/kg, i.p., q2d) exhibited 27.3% inhibition growth rate; the combination regimen exhibited 50% inhibition growth rate. CONCLUSION: The combination of HCPT with VP-16 had significant synergistic effect against NPC in vitro and in vivo. These results suggested that the combination of HCPT with VP-16 is a promising regimen to treat NPC in clinic.

[Correlation between inhibitory effect of Manumycin on human hepatoma cancer cell HepG2 and Ras signal transduction pathway].

BACKGROUND AND OBJECTIVE: Treatment with anti-cancer agents has failed to achieve satisfactory results in hepatocellular carcinoma. In the process of hepatocarcinogenesis, Ras has been shown to play an important role. Ras requires a farnesyl moiety for activation. It has been found that farnesyltransferase inhibitor Manumycin inhibits farnesyl protein transferase, which catalyzes farnesylation. This study was designed to investigate the antitumor effect of Manumycin in human hepatoma cell line HepG2 and try to clarify its influence on Ras pathway. METHODS: The growth inhibitory effect of farnesyltransferase inhibitor Manumycin on human hepatoma cell line HepG2 was observed by using [3H]thymidine incorporation assay. The relative protein expressions of pan-Ras, N-Ras, ERK1/2, AKT, and MKP-1 affected by Manumycin were determined by using Western blot analysis. RESULTS: Manumycin(5, 10, 20, 40, and 80 mumol/L) significantly inhibited cell growth of human hepatoma cell line HepG2 with IC50 value of (17.1 +/- 2.6) mumol/L. Manumycin could inhibit both pan-Ras and N-Ras in human hepatoma HepG2 cells, but its inhibitory effect on pan-Ras of cell membrane was much stronger. Phospho-MAPK and phospho-AKT decreased significantly after treatment of HepG2 cells with Manumycin, while total MAPK and AKT were hardly affected. After treatment with 10 nmol/L wortmannin for 1 h, which had potent inhibitory effect on phosphorylation of AKT, Manumycin had stronger inhibitory effect on phosphorylation of AKT as compared to treatment without wortmannin, eventhough AKT protein levels were still unaffected. Furthermore, the expression of MKP-1 was elevated through manumycin treatment in a concentration-dependent manner. CONCLUSION: Manumycin may significantly inhibit the growth of human hepatoma cell line HepG2, which was related to its inhibition on the combination of Ras and cell membrane and increasing the expression of MKP-1, accordingly inhibiting activation of ERK1/2 and AKT. These results suggest that Manumycin antagonizes the growth of HepG2 via the suppression of ras farnesylation blocking the function of oncogenic ras against and could be a potential new anti-cancer agents human cancer, including hepatocellular carcinoma.

Caspases promoted DADAG-induced apoptosis in human leukemia HL-60 cells.

AIM: To investigate the roles of caspases in diacetyldianhydrogalactitol (DADAG)-induced apoptosis in human leukemia HL-60 cells. METHODS: Inhibition of proliferation was measured by MTT assay. DADAG-induced apoptosis in HL-60 cells was observed by electron microscopy, flow cytometry, and DNA fragmentation assay. Caspase-3 activity was determined by ApoAlert CPP32 colorimetric assay kit. The cleavage of substrates of caspases was detected by Western blot. RESULTS: DADAG exhibited potent antiproliferative activity and induced apoptosis in HL-60 cells. After treatment with DADAG 8 mg/L for 24 h, caspase-3 activity increased markedly and the cleavage of poly-(ADP-ribose) polymerase (PARP), lamin B, and DFF45 appeared. All of the apoptotic signals were suppressed by z-VAD fmk (a general inhibitor of caspase activities), whereas z-DEVD fmk, a selective inhibitor of caspase-3 activity, only induced partial reversion of the apoptotic effects. CONCLUSION: DADAG induced apoptosis in HL-60 cells by activating caspases. Caspases promoted apoptosis through the cleavage of substrates of PARP, lamin B, and DFF45.