A Solid-State Electrochemical Sensor for Determination of Effective Acidity of Aqueous Solutions with High Acidity / 分析化学

A new all-solid state electrode modified with poly ( o-aminophenol-co-o-phenylenediamine ) film was prepared by cyclic voltammetry.The electrochemical response of the electrode to various solutions in the available acidity range of 1.00 × 10-12-10.0 mol/L was studied by cyclic voltammetry.The results showed that the reduction peak potentials and the available acidity of solution showed good linear relationship in 3 stages of 1.00×10-10-0.10 mol/L, 0.10-2.00 mol/L and 2.00-10.0 mol/L respectively, and the regression equations were Epc=0.0456lgC(H+)-0.295, Epc=0.0803c(H+)-0.309, and Epc=0.0278c(H+)-0.188, respectively.There were similar responses in the solutions of H2 SO4 , HNO3 and HClO4 in the concentration range of 1.00-8.00 mol/L.The preparation method of electrode was simple, and the determination range of available acidity was as wide as 1.0 ×10-10-10.0 mol/L, which laid the foundation for the development of solid-state electrochemical sensors for determination of acidity of high acidity solution.

Celastrus orbiculatus extract inhibits tumor angiogenesis by targeting vascular endothelial growth factor signaling pathway and shows potent antitumor activity in hepatocarcinomas in Vitro and in Vivo / 中国结合医学杂志

<p><b>OBJECTIVE</b>Celastrus orbiculatus Thunb. has been used for thousands of years in China as a remedy against cancer and inflammatory diseases. This study aims to investigate whether C. orbiculatus extract (COE) could inhibit angiogenesis, which is the pivotal step in tumor growth, invasiveness, and metastasis.</p><p><b>METHODS</b>In this study, the extract from the stem of C. orbiculatus was used. Mouse hepatic carcinoma cells (Hepa1-6) were treated with COE in different nontoxic concentrations (10, 20, 40, 80, and 160 μg/mL). The mRNA and protein expression levels of vascular endothelial growth factor (VEGF) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively; the active fractions were further tested on C57BL/6 mice and human umbilical vein endothelial cells (HUVEC) for any antiangiogenic effects.</p><p><b>RESULTS</b>COE significantly inhibited proliferation and induced apoptosis in Hepa1-6 cells and inhibited VEGF expression at both mRNA and protein levels. Furthermore, this agent inhibited the formation of the capillary-like structure in primary cultured HUVEC in a dose-dependent manner. In vivo, COE significantly reduced the volume and weight of solid tumors with low adverse effects and decreased tumor angiogenesis.</p><p><b>CONCLUSIONS</b>In summary, COE could be used to treat hepatic carcinoma. The mechanisms of the antitumor activity of COE may be due to its effects against tumor angiogenesis by targeting the VEGF protein.</p>

Nitric oxide promotes the differentiation of neural stem cells in vitro derived from the subventricular zone of neonatal rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effect of nitric oxide (NO) on the differentiation of neural stem cells (NSCs) derived from subventricular zone (SVZ) of neonatal rats in vitro.</p><p><b>METHODS</b>Conventional method was used to isolate and culture the NSCs from SVZ. Diethylenetriamine/NO(DETA/NO) was used as NO donor and Nitro-L-arginine methylester (L-NAME) was used as inhibitor of nitric oxide synthase (NOS). The immunofluorescence was used to identify the expression of nestin (a marker of NSCs), beta-III-tubulin (Tuj-1, a marker of neurons), glial fibrillary acidic protein (GFAP, a marker of astrocytes) and nNOS. The concentration of NO in medium was measured by Greiss assay.</p><p><b>RESULTS</b>Cultured neurospheres were nestin-, BrdU- and nNOS-positive. After treatment with 40 micromol/L, 50 micromol/L and 60 micromol/L of DETA/NO for 5 days, the concentration of NO released was increased significantly (P < 0.01) as compared with that of the control group. The percentage of both differentiated neurons and astrocytes was increased significantly (P < 0.01 and P < 0.05) as compared with that of the control group. After treatment with 100 micromol/L, 150 micromol/L and 200 micromol/L of L-NAME for 5 days, the concentration of NO released was decreased as compared with that of the control group (P < 0.05). The percentage of both differentiated neurons and astrocytes were decreased as compared with that of the control group (P < 0.05).</p><p><b>CONCLUSION</b>NO could directly promote the differentiation of NSCs derived from rat subventricular zone in vitro.</p>

Possible involvement of integrin signaling pathway in the process of recovery from restraint stress in rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To search novel genes or pathways involved in the recovery process after restraint stress in rats.</p><p><b>METHODS</b>We compared the hypothalamus transcriptional profiles of two different recovery patterns (fast recovery vs slow recovery) from restraint stress in rats using oligonucleotide microarray, the recovery pattern was determined by the decrement of plasma adrenocorticotropic-hormone (ACTH) and corticosterone levels during one hour recovery period after stress. A real-time quantitative RT-PCR was applied to validate the differential expressed genes.</p><p><b>RESULTS</b>Analysis of the microarray data showed that most of genes were not differentially expressed between fast recovery group and slow recovery group. Among the differentially expressed genes we found that talin, together with serine/threonine protein phosphatase PP1-beta catalytic subunit (PP-1B) and integrin alpha-6 precursor (VLA-6) genes, were at least 1.5 fold up-regulated in the fast recovery group, while junctional adhesion molecule 1 (F11r) was 1.5 fold down-regulated in the fast recovery group.</p><p><b>CONCLUSION</b>The results implied that integrin signaling pathway may be involved in the recovery from restraint stress in rats. The present study provided a global overview of hypothalamus transcriptional profiles during the process of recovery from the restraint stress in rats. The integrin signaling pathway seems to be involved in the recovery process, which deserves further study to clarify the integrin-mediated recovery mechanism after restraint stress.</p>

Forced running enhances neurogenesis in the hippocampal dentate gyrus of adult rats and improves learning ability / 生理学报

To investigate the effect of forced running in motor-driven wheel on neurogenesis in the hippocampal dentate gyrus (DG) of adult rats, 5-bromo-2-deoxyuridine (BrdU), a thymidine analog was applied to mark cell proliferation. Neuroepthelial stem cell protein (nestin) expression was used to identify neural stem/precursor cells. The BrdU- and nestin-positive cells were examined by immunohistochemical technique. The ability of learning was evaluated by Y-maze test to explore the functional role of the newborn cells in the DG after forced running. It was found that the number of BrdU- and nestin-positive cells in the DG in running groups was significantly increased compared to that in the control group (P<0.05). The effect of forced running on neurogenesis was intensity-dependent. In addition, an improvement of learning ability in Y-maze test was observed after forced running. These findings suggest that forced running in motor-driven wheel could enhance neurogenesis in the hippocampal DG of adult rats and improve learning ability.

Effects of exercise on neurogenesis in the dentate gyrus and ability of learning and memory after hippocampus lesion in adult rats / 神经科学通报·英文版

Objective To explore the effects of exercise on dentate gyrus (DG) neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrahippocampal microinjection of kainic acid (KA). Bromodeoxyuridine (BrdU) was used to label dividing cells. Y maze test was used to evaluate the ability of learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity: lightly running, moderately running, or heavily running. Results Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number (EN) in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. Conclusion Moderate exercise could enhance the DG neurogenesis and ameliorate the ability of learning and memory in hippocampus-lesioned rats.

Study on the analgesic effect and mechanism of Zhitong capsule in adjuvant arthritis rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the analgesic effect of Zhitong Capsule (ZTC) and study its mechanism in adjuvant arthritis (AA) rats.</p><p><b>METHODS</b>Forty-eight male Sprague-Dawley rats were randomly divided into six groups with 8 rats in each group. On the first day, except to those in the normal group that were treated with normal saline, the same amount of Freund's complete adjuvant (FCA) was given through intradermal injection into the right hind paw to all the rats in the other groups. From the 17th day of the modeling on, the rats in groups of ZTC were administered daily through gastrogavage with a dose of 1000, 500, 250 mg/kg respectively, while equal volume of normal saline was given to those in the normal group and model group, and an equal volume of aspirin (ASA) solution was given to rats in the ASA group through gastrogavage for 10 days, once per day, and on the 27th day, the analgesic effect of ZTC was measured with heat withdraw method. The activities and contents of superoxide dismutase (SOD) and lipid peroxides (LPO) in serum were observed by spectrophotometry, and the level of beta-endorphin (beta-EP) in hypothalamus were determined by the assay of immunohistochemistry.</p><p><b>RESULTS</b>ZTC showed significant effects on enhancing the pain threshold and at the same time it increased the activities of SOD and reduced the contents of LPO in serum. ZTC could also increase the level of beta-EP in hypothalamus.</p><p><b>CONCLUSION</b>ZTC has analgesic effect and its mechanism is probably related with its effect in inhibiting the level of oxygen free radicals in serum and increasing the level of beta-EP of hypothalamus in rats.</p>

Cold stress induces the suppression of splenic NK cell activity and the c-fos expression in rat brain / 中国应用生理学杂志

<p><b>AIM</b>To observe the effect of cold stress on the splenic NK cell activity and the c-fos expression in rat brain.</p><p><b>METHODS</b>Rats were maintained in cold chamber at 4 degrees for 4 h. The 51Cr release assay from YAC-1 cells was used to determine the splenic NK cell activity and the double staining of ABC method was employed to observe the immunoreactive expression of Fos, arginine-vasopressin and tyrosine hydroxylase.</p><p><b>RESULTS</b>Cold stress could induce a marked suppression of splenic NK cell activity and a significant expression of Fos protein in hypothalamic paraventricular nucleus(PVN), as well as in the brainstem locus coeruleus (LC). Double staining showed c-expression of Fos and arginine-vasopressin in some of PVN neurons, and co-expression of Fos and tyrosine hydroxylase in the majority of LC neurons.</p><p><b>CONCLUSION</b>The vasopressinergic neurons in PVN and the catecholaminergic neurons in LC might be probably involved in the suppression of splenic NK cell activity induced by cold stress.</p>