Effects of the crown ether cavity on the performance of anion exchange membranes.

Anion exchange membrane fuel cells (AEMFCs) have emerged as a promising alternative to proton exchange membrane fuel cells (PEMFCs) due to their adaptability to low-cost stack components and non-noble-metals catalysts. However, the poor alkaline resistance and low OH- conductivity of anion exchange membranes (AEMs) have impeded the large-scale implementation of AEMFCs. Herein, the preparation of a new type of AEMs with crown ether macrocycles in their main chains via a one-pot superacid catalyzed reaction was reported. The study aimed to examine the influence of crown ether cavity size on the phase separation structure, ionic conductivity and alkali resistance of anion exchange membranes. Attributed to the self-assembly of crown ethers, the poly (crown ether) (PCE) AEMs with dibenzo-18-crown-6-ether (QAPCE-18-6) exhibit an obvious phase separated structure and a maximum OH- conductivity of 122.5 mS cm-1 at 80 °C (ionic exchange capacity is 1.51 meq g-1). QAPCE-18-6 shows a good alkali resistance with the OH- conductivity retention of 94.5% albeit being treated in a harsh alkali condition. Moreover, the hydrogen/oxygen single cell equipped with QAPCE-18-6 can achieve a peak power density (PPD) of 574 mW cm-2 at a current density of 1.39 A cm-2.

Design and synthesis of fluorinated peptides for analysis of fluorous effects on the interconversion of polyproline helices.

The unique interaction between fluorine atoms has been exploited to alter protein structures and to develop synthetic and analytical applications. To expand such fluorous interaction for novel applications, polyproline peptides represent an excellent molecular nanoscaffold for controlling the presentation of perfluoroalkyl groups on their unique secondary structure. We develop approaches to synthesis fluorinated peptides to systematically investigate how the number, location and types of the fluorous groups on polyproline affect the conformation by monitoring the transition between the two major polyproline structures PPI and PPII. This work provides valuable information on how fluorous interaction affects the peptide structure and also benefits the design of functional fluorous molecules.

Plasma VDBP, 25(OH)D, and GSH levels predict surgical outcome in patients with cervical spondylotic myelopathy.

This study intends to investigate the predictive values of plasma Vitamin D-binding protein (VDBP), 25-hydroxyvitamin D [25(OH)D], and glutathione (GSH) levels in the outcome of cervical spondylotic myelopathy (CSM) surgery. Surgery outcomes of 236 CSM patients were determined. Recovery rate was calculated according to Japanese Orthopaedic Association (JOA) scores during follow-up. CSM patients with a recovery rate >50% were assigned with good prognosis and the rest were with fair prognosis. Preoperative and postoperative neurologic function scores were compared among groups. Plasma VDBP and 25(OH)D levels, as well as GSH levels were measured by ELISA and glutathione reductase recycling assay, respectively. Pearson's correlation coefficient was performed to analyze the correlation among plasma VDBP, 25(OH)D, and GSH levels. Receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of plasma VDBP, 25(OH)D, and GSH levels for surgical outcome. Logistic regression model was used to analyze risk factors for surgical outcome. Compared with those with fair prognosis, CSM patients with good prognosis group exhibited higher postoperative neurologic function scores, plasma VDBP, 25(OH)D, and GSH levels, and better improvements in spinal cord compression and motions of the cervical vertebra. Plasma VDBP, 25(OH)D, and GSH levels were favorable prognostic factors for CSM surgical outcome. The sensitivity and specificity of plasma VDBP, plasma 25(OH)D, and plasma GSH were 89.8% and 91.7%, 85.8% and 84.4%, and 79.5% and 91.7%, respectively. Our study provides evidence that higher plasma VDBP, 25(OH)D, and GSH levels may predict better surgical outcome in CSM patients.

Controlling Ligand Spacing on Surface: Polyproline-Based Fluorous Microarray as a Tool in Spatial Specificity Analysis and Inhibitor Development for Carbohydrate-Protein Interactions.

Multivalent carbohydrate-protein interactions are essential for many biological processes. Convenient characterization for multivalent binding property of proteins will aid the development of molecules to manipulate these processes. We exploited the polyproline helix II (PPII) structure as molecular scaffolds to adjust the distances between glycan ligand attachment sites at 9, 18, and 27 Å on a peptide scaffold. Optimized fluorous groups were also introduced to the peptide scaffold for immobilization to the microarray surface through fluorous interaction to control the orientation of the helical scaffolds. Using lectin LecA and antibody 2G12 as model proteins, the binding preference to the 27 Å glycopeptide scaffold, matched the distance of 26 Å between its two galactose binding sites on LecA and 31 Å spacing between oligomannose binding sites on 2G12, respectively. We further demonstrate this microarray system can aid the development of inhibitors by transforming the selected surface-bound scaffold into multivalent ligands in solution. This strategy can be extended to analyze proteins that lacking structural information to speed up the design of potent and selective multivalent ligands.

Impact of aphid alarm pheromone release on virus transmission efficiency: When pest control strategy could induce higher virus dispersion.

Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-ß-farnesene (EßF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EßF release on aphid and virus dispersion under laboratory conditions. EßF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals.

New flavonoid from Patrinia villosa.

CONTEXT: Patrinia villosa (Thunb.) Juss (Valerianaceae) is an important ancient herbal medicine widely used for inflammation, wound healing, and abdominal pain. But little is known of the phytochemical constituents of this herbal plant. OBJECTIVE: The objective of this study is to isolate and identify the bioactive components from P. villosa. MATERIALS AND METHODS: A 70% EtOH extract of P. villosa was subjected to normal-phase silica, ODS silica gel column chromatography, and semi-preparative HPLC chromatography after partitioned successively with light petroleum, dichloromethane and n-BuOH. Chemical structures of the compounds were elucidated by spectroscopic methods including UV, 1D-NMR, 2D-NMR, HR-ESI-MS, and CD spectra. The cytotoxic activity of the new component was determined with the SMMC-7721 cell line using the MTT method after incubation for 48 h. RESULTS: A new flavonoid named patriniaflavanone A (1) along with four known compounds was isolated from P. villosa. The four known compounds were identified as luteolin 7-O-glucuronide-6″-methyl ester (2), p-hydroxyphenylacetic acid methyl ester (3), trans-caffeic acid (4), and trans-caffeic acid methylate (5) by comparison of their spectral data with the reported data. The IC50 value of patriniaflavanone A (1) on SMMC-7721 was 61.27 µM. DISCUSSION AND CONCLUSION: This is the first report on the isolation and identification of patriniaflavanone A (1), and compounds 2-5 were isolated for the first time from the title plant. Patriniaflavanone A (1) exhibited moderate cytotoxic activity.

[Inhibitory Effect of the Excretory/Scretory Proteins of Trichinella spiralis on Proliferation of Human Hepatocellular Carcinoma HepG2 Cell line].

Human hepatocellular carcinoma HepG2 Cell line were cultured with different concentrations of excretory/secretory proteins from Trichinella spiralis, and MTT assay was used to evaluate the cell inhibition rate. After co-cultured with 300 µg/ml excretory/secretory proteins for 24 h, the HepG2 cells were observed under a fluorescence microscope with AO and EB staining. When co-cultured with 75 µg/ml excretory/secretory proteins for 24 h, the HepG2 cells were quantified by flow cytometry using Annexin V-FITC/PI stain, and the expression of cleaved-caspase 9 was detected by immunofluorescence assay. The proliferation of HepG2 cells was inhibited significantly by excretory/secretory proteins in a dosage dependant manner. Under fluorescence microscope, some HepG2 cells presented typical apoptotic morphologic changes and the cleaved-caspase 9 protein expression was higher than that of the control. The early and late apoptotic cells and necrotic ones occupied 17.9%, 7.3%, and 6.6%, respectively.

Metastatic lung adenocarcinoma to the bladder: A case report.

Urothelial cancer is the most frequently diagnosed type of malignant tumor in the bladder, of which primary adenocarcinoma accounts for a small percentage. Secondary malignancies, in particular metastatic adenocarcinoma from the lung, are exceedingly rare, with only six cases previously reported in the literature. The present study describes the case of a 71-year-old Chinese male patient with known lung cancer for >2 years, who was diagnosed with metastatic adenocarcinoma to the bladder. The histopathological characteristics and immunohistochemical features of the patient are reported. It was proposed that pathologists should consider the possibility of metastatic adenocarcinoma from the lung, rather than assume a diagnosis of primary adenocarcinoma of the bladder or direct invasion of adenocarcinoma from the surrounding organs. Furthermore, it is essential to determine the medical history of each patient and observe the immunohistochemical features of all tumors prior to diagnosis.

[Synthesis and antitumor activity of fluoroquinolon-3-yl-s-triazole sulfide ketones and their derivatives from ciprofloxacin].

To discover an efficient strategy for the conversion of the antibacterial activity of fluoroquinolones into the antitumor activity, the three series of C-3 s-triazole-based derivatives including sulfide ketones (6a-6g), thiosemicarbazones (7a-7g) and fused heterocyclic thiazolotriazoles (8a-8g) were synthesized from ciprofloxacin (1), respectively. The structures were characterized by elemental analysis and spectral data. The antitumor activity was tested against three tumor cell lines (Hep-3B, Capan-1 and HL60) using the MTT assay. The three types of compounds all exhibited stronger anti-proliferative activities than ciprofloxacin in the test. The order of their activities was in compounds 7>8>6, and the order of selectivity against cancer cell lines was Capan-1, Hep-3B and HL60. Meanwhile, the SAR revealed that some compounds with electron-drawing group substituted such as fluoro- and nitro-phenyl compounds (6f, 7f, 8f) and (6g, 7g, 8g) displayed more significant activity than the control compounds, especially the IC50 values of thiosemicarbazone compounds 7f and 7g against Capan-1 was comparable to doxorubicin. Thus, a five-membered triazole as the C-3 bioisostere modified with the functionalized side-chain of sulfide-ketone thiosemicarbazone warrants special attention and further investigation.

Solanum Nigrum polysaccharide (SNL) extract effects in transplanted tumor-bearing mice--erythrocyte membrane fluidity and blocking of functions.

BACKGROUND: Solanum nigrum L. has been used in traditional Chinese medicine because of its diuretic and antipyretic effects. The present research concerned effects of crude polysaccharides isolated from Solanum nigrum L. on erythrocyte membranes of tumor-bearing S180 and H22 in mice. MATERIALS AND METHODS: Fluorescence- labeled red blood cell membranes were used with DPH fluorescence spectrophotometry to examine erythrocyte membrane fluidity, and colorimetry to determine degree of erythrocyte surface membrane blocking. Extent of reaction by tumor-bearing mice with the enzyme erythrocyte membrane bubble shadow detection of red cell membrane variation in the degree of closure before and after administration. RESULTS: Solanum nigrum polysaccharide could significantly improve the S180 and H22 tumor-bearing mice erythrocyte membrane fluidity, compared with the control group, the difference was significant (p<0.01), SNL can significantly improve the red blood cell membrane and then S180 tumor-bearing mice sealing ability, compared with the negative control group, the difference was significant(p<0.05, p<0.01). H22 tumor-bearing mice can increase red cell membrane and then sealing ability, the difference was significant (p<0.05). Solanum nigrum polysaccharide degree of fluidity and blocking two transplanted tumors in mice restored the ability to raise the red cell membrane has a significant effect. CONCLUSIONS: Solanum nigrum L.-type mice transplanted tumor can affect the red blood cell membrane fluidity and re-closed, through the red cell membrane of red blood cells to enhance the immune function of the possibility of erythrocyte immunity against tumor formation garland provide experimental basis.

[Incidence and risk factors of HIV and syphilis seroconversion among men who have sex with men in Beijing].

OBJECTIVE: To study the incidence and risk factors of HIV and syphilis seroconversion among men who have sex with men (MSM) in Beijing. METHODS: A total of 550 MSM were recruited on the basis of community and followed up after 6 and 12 months in Beijing. Each subject was investigated by only one investigator at one time to collect information on demographics and behaviors. Blood samples were collected to test HIV and syphilis seroconversion. ELISA was used for screening test, west blotting (WB) and Particle agglutination were used for confirmatory test. RESULTS: A total of 550 MSM investigated, among which 4.5% (25/550) were HIV-positive and 29.3% (161/550) were syphilis-positive. For 525 HIV-negative MSM, 87.0% (457/525) retained during the 12-month investigation. Seroincidence for HIV and syphilis were 3.37/100 person-years (95%CI = 1.66 - 5.08) and 9.32/100 person-years (95%CI = 5.87 - 12.77) respectively. HIV seroconversions for those who performed and did not perform rectal douching after homosexual anal intercourse in the past 3 months were 7.11/100 and 0.76/100 person-years respectively. Multivariate Cox regression analysis revealed that rectal douching after homosexual anal intercourse in the past 3 months (HR = 9.23, 95%CI = 2.08 - 40.88) was significantly associated with HIV seroconversion. Syphilis seroconversions for those who met male sex partners in parks, public washrooms or bathhouses in the past 3 months were 41.77/100 and 7.97/100 person-years respectively. Syphilis seroconversions for those who performed and did not perform rectal douching after homosexual anal intercourse in the past 3 months were 16.17/100 and 4.92/100 person-years respectively. In the past 3 months, meeting male sex partners in parks, public washrooms or bathhouses (HR = 4.67, 95%CI = 1.77 - 12.34) and performing rectal douching after homosexual anal intercourse (HR = 3.09, 95%CI = 1.40 - 6.83) were significantly associated with syphilis seroconversion. CONCLUSION: The seroconversions of HIV and syphilis during the follow-up visits in this MSM cohort study in Beijing were very serious, and that the associated factors for seroconversions were rectal douching after homosexual anal intercourse and meeting male sex partners in parks, public washrooms or bathhouses.

Plasmodium yoelii: assessment of production and role of nitric oxide during the early stages of infection in susceptible and resistant mice.

There is conflicting evidence regarding the role of nitric oxide (NO) in the process of resistance against blood-stage malaria parasites. In this study, we used two strains of mice infected with Plasmodium yoelii 17XL in order to assess the NO production profile and its possible role during the early stage of malaria infection. We found a greater elevation of NO production associated with a sharp increase in the levels of IFN-gamma in infected DBA/2 mice, compared with infected BALB/c mice. This difference was associated with relatively lower parasitemia, a higher constituent ratio of infected reticulocytes, and greater survival in DBA/2 mice. Endogenous IFN-gamma driving Th1 immunity was responsible for NO production. Moreover, schizonts treated in vitro with NO donors caused a delayed infection to BALB/c mice in a dose and time-dependent manner. These data, thus, suggest that NO may play an inhibitory role in Plasmodium infection.

[Synergistic lethal effect of mDRA-6 and nimesulide on human hepatocellular cancer cell line SMMC-7721].

BACKGROUND & OBJECTIVE: Both mDRA-6, a monoclonal antibody of death receptor 5 (DR5) in human cells prepared by our key laboratory, and nimesulide, a specific cyclooxygenase-2 (COX-2) inhibitor, can induce apoptosis of some malignant tumor cells. This study was to investigate the lethal effects of mDRA-6 and nimesulide on human hepatocellular cancer cell line SMMC-7721, and explore the possible mechanism. METHODS: The expression of DR5 on SMMC-7721 cells was detected by flow cytometry (FCM). SMMC-7721 cells were treated with mDRA-6 and nimesulide alone or in combination. Cell morphology was observed under microscope with Hoechst33258 staining. Cytotoxicity was examined by MTT assay. Cell apoptosis was detected by FCM. RESULTS: The positive rate of DR5 on SMMC-7721 cells was 95.0%. The apoptosis of SMMC-7721 cells could be induced by both mDRA-6 and nimesulide: the apoptosis rates were 10.5% when treated with 25 ng/mL mDRA-6 for 12 h, 35.0% when treated with 1 600 ng/mL mDRA-6, 5.0% when treated with 200 micromol/L nimesulide, and 34.0% when treated with 800 micromol/L nimesulide. The combination of mDRA-6 and nimesulide exhibited synergistic effect on the apoptosis of SMMC-7721 cells (q=1.23): the apoptosis rates were 31.2% when treated with 200 micromol/L nimesulide and 25 ng/mL mDRA-6 for 12 h, and 91.1% when treated with 200 micromol/L nimesulide and 1 600 ng/mL mDRA-6 for 12 h. CONCLUSIONS: Both mDRA-6 and nimesulide can induce the apoptosis of SMMC-7721 cells. The combination of mDRA-6 and nimesulide exhibits synergistic lethal effect on SMMC-7721 cells.

[Leukemic cell apoptosis induced by anti-human DR5 monoclonal antibody mDRA-6].

AIM: To investigate the apoptotic effect of anti-human DR5 (death receptor 5 of TRAIL) monoclonal antibody mDRA-6 on leukemic cells. METHODS: The morphological changes of leukemic cells were observed by fluorescence microscope. The cytotoxic and apoptotic effects of mDRA-6 on Jurkat, HL-60 and K562 cells were detected by MTT analysis and flow cytometry with Annexin V-FITC/PI staining. RESULTS: Chromatin condensation, budding and apoptotic bodies were observed in Jurkat and HL-60 cells treated by mDRA-6. Death and apoptosis of leukemic cells treated by mDRA-6 were increased, but the effect of mDRA-6 on K562 cells was not obvious. CONCLUSION: Apoptosis of leukemic cells can be induced by anti-human DR5 monoclonal antibody mDRA-6. Different leukemic cell lines are of different sensitivity to mDRA-6.

[Adriamycin enhances anti-human DR5 monoclonal antibody (mDRA-6) induced HL-60 cells apoptosis].

OBJECTIVE: To investigate synergistic killing effect of anti-human DR5 (death receptor 5 of TRAIL) monoclonal antibody (mDRA-6) and adriamycin(Adr) on HL-60 cells. METHODS: mDRA-6 was prepared by immunizing BALB/c mice with DR5 protein. DR5 expression on Adr-treated HL-60 cells was detected by flow cytometry. Morphologic changes of HL-60 cells were observed under fluorescence microscope. Cytotoxic and apoptotic effects of mDRA-6 and Adr on HL-60 cells were measured by MTT analysis. DNA fragmentation was detected by agarose gel electrophoresis. RESULTS: Adr induce DR5 expression on HL-60 cells. Cell budding, chromatin condensation and apoptotic body formation were observed in HL-60 cells treated by mDRA-6 and Adr. Death and apoptosis of these cells and DNA ladder were exhibited on agarose gel electrophoresis. CONCLUSION: mDRA-6 and Adr have synergistic killing effect on HL-60 cells.

[Effects of integrin beta1 on phycocyanin inhibiting proliferation of K562 cells].

This study was purposed to investigate the effect of phycocyanin at different concentration on proliferation of K562 cells, to detect the changes of integrin beta1 expression and intracellular focal adhesion kinase (FAK) gene expression on the surface K562 cells treated with phycocyanin, and to explore the possible mechanism of integrin beta1 effect on phycocyanin inhibiting proliferation of K562 cells. The expression level of integrin beta1 on the surface of K562 cells was evaluated by flow cytometry (FCM); the growth of K562 cells treated with phycocyanin was measured by MTT assay; the expression level of FAK mRNA was analyzed by relatively quantitative RT-PCR after four-day culture of K562 cells with phycocyanin of 40 microg/ml, 80 microg/ml and 160 microg/ml, respectively. The results showed that integrin beta1 expression on the surface of K562 cells was significantly higher than that in bone marrow mononuclear cells (BMMNC) from normal subjects. Phycocyanin could not change the level of integrin beta1 expression. Phycocyanin could increase the expression of FAK gene on K562 cells and inhibit the proliferation of K562 cells. It is concluded that phycocyanin can inhibit the proliferation of K562 cells through enhancing the conjunction of cell stroma with integrin beta1 on K562 cell surface, up-regulating the expression level of FAK gene in K562 cells, restoring the signaling pathway of proliferation inhibition mediated by integrin beta1. The possible mechanism of phycocyanin in the proliferation inhibition of K562 cells is to increase the expression of FAK gene. The phycocyanin may be considered as a potential agent for inhibition of cancer cell proliferation.

[Regulatory effect of integrin alpha5 and beta1 on proliferation inhibition of K562 cells induced by interferon alpha-2b].

BACKGROUND & OBJECTIVE: Integrin beta1 can inhibit the proliferation of chronic myelocytic leukemia (CML) ph+ cells. The dysfunction of integrin beta1 might accelerate the growth of CML ph+ cells. This study was to explore the effects of integrin alpha5 and beta1 on the proliferation inhibition of K562 cells induced by IFNalpha-2b. METHODS: The expression indexes of integrin alpha5 and beta1 on K562 cells, the binding capability of K562 cells to fibronectin (FN), and K562 cell-FN binding blocking induced by integrin alpha5 and beta1 antibodies were evaluated by flow cytometry (FCM). The viability of K562 cells, treated with IFNalpha-2b (10,000 u/ml), was observed by MTT assay. The mRNA level of focal adhesion kinase (FAK) in K562 cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) 48 h after treatment of interferon alpha-2b (IFNalpha-2b). RESULTS: The positive rates of integrin alpha5 and beta1 were significantly higher on K562 cells than on bone marrow mononuclear cells from healthy donors [(97.59+/-1.04)% vs. (64.05+/-2.38)%, (99.24+/-0.52)% vs. (72.40+/-3.56)%, P<0.05). IFNalpha-2b could not change the expression of integrin alpha5 and beta1 on K562 cells, but improved the binding capability of K562 cells to FN, which could be blocked by anti-alpha5 and/or anti-beta1 antibodies. IFNalpha-2b enhanced the expression of FAK gene, and inhibited the proliferation of K562 cells. The anti-alpha5 and anti-beta1 antibodies improved the inhibitory effect of IFNalpha-2b on the proliferation of K562 cells, and blocked IFNalpha-2b-induced increase of FAK gene expression. CONCLUSION: IFNalpha-2b could inhibit the proliferation of K562 cells through restoring the function of integrin alpha5 and beta1, enhancing binding capability of integrin alpha5 and beta1 to FN, and up-regulating FAK gene expression.