Conus textile is a kind of highly toxic and abundantly existing conus in the South China Sea. The toxin from C.textile could act on sodium channels(δ-conotoxins)and calcium channels (ω-，ε-conotoxins), respectively. Their specific chemical structure and biological activity have attracted a lot of attention in recent years. This article briefly reviews their biochemical characteristics, isolation, gene cloning, biological and neuropharmacological activities, as well as their potential applications.

The Conus venom is secreted by the duct and theca of venom. Most of conotoxins are composed of 10-40 amino acid residues with several disulfide bridges. They can specifically target neurotransmitter receptors including nAChRs, calcium ion channels, sodium ion channels and potassium ion channels, etc. Some conotoxins, such as that target N-Ca2+ channels, nAChR alpha9alpha10 subtype, TTX-R Na+ channels or NMDA receptors, have potent antinociceptive activities, omega-MVIIA, an Ca2+ channels blocker was approved by FDA in December, 2004 for marketing. Because of lower molecular weight and high specificity, conotoxins are the powerful pharmacology tools and potent analgesics without addiction. This review briefly summarizes the research progress of antinociceptive conotoxins and addresses on their targets and structure-activity relationships.
Analgesics ; pharmacology ; Calcium Channels ; drug effects ; Conotoxins ; pharmacology ; Sodium Channels ; drug effects ; Structure-Activity Relationship

AIM: To screen the cytotoxicity of degradable calcium metaphosphate (dCMP) compared with hydroxyapatite (HA). The proliferation and differentiation abilities of human marrow mesenchymal stem cells (MSC) were used to exhibit the cytotoxicity. METHODS: The cell morphology of MSC was analysed after direct contact with dCMP at different time points by scanning electron microscopy analysis. The degradation products of dCMP and HA were analysed with inductively coupled plasma torch and ion chromatography. The cytotoxic effect of degradation products of dCMP was evaluated by FACS, quantitative assay of ALP and ARS, respectively. RESULTS: dCMP enhanced the proliferation of MSC, but didn't interfere the osteogenic differentiation process of MSC and its mineralization. HA inhibited the proliferation of MSC and the mineralization of osteogenic differentiated MSC, while it did not interfere the osteogenic differentiation process of MSC. CONCLUSION: dCMP had a better cytocompatibility with MSC than HA, which might allow for its use as skeleton scaffolds.

AIM: To get high biological activity of recombinant human bone morphogenetic protein-2 (rhBMP-2) expressed in Escherichia coli by the methods of refolding. METHODS: The rhBMP-2, expressed in Escherichia coli, was washed by Triton X-100 and further purified by DEAE chromatography. The inclusion bodies were resolved in 8 mol/L urea,and were refolded and dimerized in the redox systems (reduced and oxidized glutathione). Finally, a one-step purification procedure based on the heparin affinity chromatography was implemented. The biological activity of purified rhBMP-2 were tested by induction of the alkaline phosphatase activity in C2C12 cells. RESULTS: The rhBMP-2 was expressed in Escherichia coli in a non-active aggregated form of inclusion bodies using a temperature-inducible expression system. The high-purified rhBMP-2 was obtained in the form of inclusion bodies by several purification courses. The rhBMP-2 was refolded and dimerized in the redox systems (reduced and oxidized glutathione) and a one-step purification procedure based on the heparin affinity chromatography was implemented to isolate the rhBMP-2 dimers and monomers. The purified rhBMP-2 dimers showed the higher biological activity than the commercial rhBMP-2. CONCLUSIONS: The method achieved the refolding of rhBMP-2 would be applied to the whole TGF-? superfamily because the BMP-2 belongs to the superfamily. Meanwhile, the inexpensive, high yield rhBMP-2 is suitable for clinic application.

AIM: To get high biological activity of recombinant human bone morphogenetic protein -2 (rhBMP-2) expressed in Escherichia coli by the methods of refolding. METHODS: The rhBMP-2,expressed in Escherichia coli, was washed by Triton X- 100 and further purified by DEAE chromatography.The inclusion bodies were resolved in 8 mol/L urea, and were refolded and dimerized in the redox systems (reduced and oxidized glutathione). Finally, a one - step purification procedure based on the heparin affinity chromatography was implemented. The biological activity of purified rhBMP - 2 were tested by induction of the alkaline phosphatase activity in C2C12 cells. RESULTS: The rhBMP - 2 was expressed in Escherichia coli in a non - active aggregated form of inclusion bodies using a temperature - inducible expression system. The high - purified rhBMP - 2 was obtained in the form of inclusion bodies by several purification courses. The rhBMP - 2 was refolded and dimerized in the redox systems (reduced and oxidized glutathione) and a one - step purification procedure based on the heparin affinity chromatography was implemented to isolate the rhBMP - 2 dimers and monomers. The purified rhBMP - 2 dimers showed the higher biological activity than the commercial rhBMP - 2. CONCLUSIONS: The method achieved the refolding of rhBMP - 2 would be applied to the whole TGF - β superfamily because the BMP - 2 belongs to the superfamily. Meanwhile, the inexpensive,high yield rhBMP - 2 is suitable for clinic application.

One of the hot spots of nanomaterials research is the preparation of carbon-dots ( C-dots) by simple steps with cheap raw materials and looking for its potential application. In this study, coal-based C-dots was prepared from coal mined of Wucaiwan in Xinjiang by mixed acids ( H2 SO4+HNO3 )/ultrasound treatment, and at the same time of structural characterization, the coal-based C-dots were used as fluorescent probe to detect metal ions in water. It was found that the coal-based C-dots were polycyclic aromatic hydrocarbons with particle size of (8±4) nm linked with oxygen-containing groups such as nitro group, possessing the annulus wall of multilayer graphene fragment structures built up by sp2 carbons. This endowed the coal-based C-dots with good dispersity in water, high absorbance and strong fluorescence. The coal-based C-dots were used as viable probes in that their fluorescence was selectively quenching by CuⅡ. The finding was exploited to design a fluorometric assay for CuⅡ with a detection limit of 9. 6 nmol/L.

OBJECTIVETo investigate the mechanism of plasma bilirubin level increase after hepatic ischemia-reperfusion in rats.

METHODSRats were divided into a sham operation group (A group), a 20 min ischemia-reperfusion group (B group) and a 35 min ischemia-reperfusion group (C group). Study time points were 6 hours and 1, 3, and 5 days after the reperfusion. Pathological changes in the livers were studied with histological slides stained with hematoxilin and eosin. Routine biochemistry methods were used to detect the bilirubin level of blood plasma and the bile drained from the ischemic hepatic lobes. RT-PCR was used to analyze the expression of the multidrug resistance-associated protein 2 (MRP2) and mRNA. Immunohistochemistry was used to analyze the localization of MRP2 in the canalicular membrane.

RESULTSB and C groups showed a mild inflammatory reaction without hepatocyte necrosis. At 6 h and 1 day after reperfusion, there was a significant increase of the plasma bilirubin level and a decrease of the bilirubin level of the drained bile in B group. These changes lasted to the day 3 and day 5 in C group. MRP2 mRNA down-regulation was found at 6 h only in the B and C groups. No localization of MRP2 in the canalicular membrane was found but it appeared in "esicules" under the canalicular membrane in C group.

CONCLUSIONSAbsence of MRP2 localization in the canalicular membrane could be the cause of the blood plasma bilirubin level increase after liver ischemia-reperfusion.

Animals ; Bilirubin ; blood ; Liver Diseases ; blood ; Male ; Multidrug Resistance-Associated Proteins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; blood

OBJECTIVETo elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics.

METHODSSeveral formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA.

RESULTSLiposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 microm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine.

CONCLUSIONThe immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.

Animals ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; administration & dosage ; immunology ; Liposomes ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; prevention & control ; Specific Pathogen-Free Organisms ; Vaccines, Subunit ; administration & dosage ; immunology

OBJECTIVESTo explore the thrombin generation capacity in patients on warfarin therapy with different prothrombin time international normalized ratio (PT-INR), the capacity in relation to bleeding, and the application of thrombin generation tests to warfarin therapy monitoring.

METHODSSeventy eight blood samples were taken from patients on warfarin therapy for more than 3 months owing to valve replacement or atrial fibrillation. The patients' case history and PT-INR were collected and thrombin generation tests were performed in all samples.

RESULTSPatients were ranked into three groups according to different PT-INR. There were 23 patients in group I with PT-INR from 1.51 to 2.00, 39 patients in group II with PT-INR from 2.01 to 3.00, and 16 patients in group III with PT-INR from 3.01 to 4.26. There were significant differences between each two of the three groups in lag time, peak, and ttpeak (time to peak) (P <0.01). There was a significant difference between group I and group II in endogenous thrombin potential (ETP) (P = 0.0001), but not between group II and group III (P= 0.06). Five patients developed bleeding and their ETP was less than 15% of normal control.

CONCLUSIONIn patients on warfarin therapy, when the PT-INR was more than 3.0, increasing the dose of warfarin doesn' t decrease the thrombin generation, but increase bleeding risk. PT-INR combined with ETP may better reflect patient's coagulation status, therefore be of more significance in preventing bleeding.

Adult ; Aged ; Aged, 80 and over ; Anticoagulants ; administration & dosage ; adverse effects ; Atrial Fibrillation ; drug therapy ; enzymology ; Drug Monitoring ; methods ; Female ; Hemorrhage ; chemically induced ; prevention & control ; Humans ; International Normalized Ratio ; Male ; Middle Aged ; Prothrombin Time ; Thrombin ; biosynthesis ; Warfarin ; administration & dosage ; adverse effects

Objective To investigate the bacterial colonization and disinfection effect of infusion connectors in neo-natal intensive care unit(NICU),and provide clinical reference for improving the safety management of intravenous infusion in neonates.Methods 59 infusion connectors in NICU were selected as the control group.52 disinfected infusion connectors during the same period were selected as the observation group A,meanwhile,disinfection time and method used by nurses were observed.After training on disinfection method,50 disinfected infusion connectors were selected as the observation group B.All infusion connectors were sampled for culture.Results In the control group,bacteria were detected from 53 connectors,with a detection rate of 89.8％.Among them,39 connectors were isolated 1 bacterial specie respectively,13 were isolated 2 bacterial species respectively and 1 was isolated 3 bacterial species.Bacteria were detected from 13 connectors in observation group A,and the detection rate was 25.0％.In observation group B,bacteria were detected from 4 connectors,with a detection rate of 8.0％.Diffe-rence in the positive rates of bacterial culture before and after training was statistically significant(x2=84.418,P＜0.001).Conclusion Infusion connectors in NICU are prone to be contaminated.Effective disinfection can significantly reduce bacterial colonization.Health care workers should be aware of the risks of infusion-associated infection,standardize infusion operation,strengthen the management of infusion devices,and explore more effective disinfection methods.