Objective To investigate the effect of intravenous midazolam on the response of parafascicular nucleus(Pf) to noxious stimuli in rats. Methods Twenty SD rats of both sexes weighing 260-300g were used in the study. The animals were anesthetized with intraperitoneal urethane(1.2 g/kg) . A hole was drilled in the skull. Under stereomicroscope micro-glass electrode was inserted into Pf nucleus and the characteristic discharge of nociceptive neurons was recorded. The experiment was then performed in four steps. The discharge was recorded in the basal state (A), when hind paw was pinched by a pair of strong forceps: noxious stimuli (B) , 2 min after midazolam 0.2 mg/kg was given intravenously , step B was repeated (C) and flumazenil 0.05mg was given iv and 2 min later step B was repeated (D) . There was a pause of 5 min after each step. Results The characteristic discharge of nociceptive neurons was recorded only in 9 animals and the data from 6 animals were complete and could be analyzed. Noxious stimuli induced significant increase in spike of discharge of nociceptive neurons. Midazolam significantly depressed the response of nociceptive neurons to noxious stimuli. There was no significant difference in the mean spikes of discharge of nociceptive neurons between step A and C. After flumazenil the mean spike of discharge increased again in response to noxious stimuli. Conclusion Midazolam can inhibit the activity of the nociceptive neurons located in Pf nucleus, probably through GABA-BZ receptor.

ObjectiveTo observe the effect of adipose-derived stem cells (ADSCs) compound injective thermo-sensitive chitosan scaffold transplantation on content of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) in early degenerate lumbar intervertebral disc of rabbits. Methods24 white New Zealand rabbits (no limit of male or female) were randomly and equally divided into 4 groups: A. Degeneration model group: nucleus aspiration. B. ADSCs compound chitosan transplantation group. C. Cell-free chitosan transplantation group. D. Blank control group: only explore the target intervertebral disc. When aspirate pulposus with 21G needle, inject ADSCs-scaffold complex and chitosan scaffold respectively. The samples of L2-3, L3-4, L4-5, L5-6 intervertebral disc were obtained from 2 rabit in each group 2, 4, 8 weeks after operation. The contents of TNF-α, IL-1β were measured with ELISA. ResultsAll animals survived after the operation. Compare with the blank control group, the contents of TNF-α, IL-1β in degeneration model group increased significantly (P＜0.05). It decreased significantly (P＜0.05) in ADSCs compound chitosan transplantation group and cell-free chitosan transplantation group compared to model group. IL-1β decreased significantly (P＜0.05) 8 week after operation in ADSCs compound chitosan transplantation group compared to cell-free chitosan transplantation group. ConclusionADSCs compound injective thermo-sensitive chitosan scaffold transplantation in early degenerate lumbar intervertebral disc could decrease the content of TNF-α, IL-1β, and may regulate the inflammatory response.

Although methyltransferase has been recognized as a major element that governs the epigenetic regulation of the genome during temozolomide (TMZ) chemotherapy in glioblastoma multiforme (GBM) patients, its regulatory effect on glioblastoma chemoresistance has not been well defined. This study investigated whether DNA methyltransferase (DNMT) expression was associated with TMZ sensitivity in glioma cells and elucidated the underlying mechanism. DNMT expression was analyzed by western blotting. miR-20a promoter methylation was evaluated by methylation-specific PCR. Cell viability and apoptosis were assessed using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP-biotin nick end labeling assays, respectively. The results showed that compared with parental U251 cells, DNMT1 expression was downregulated, miR-20a promoter methylation was attenuated and miR-20a levels were elevated in TMZ-resistant U251 cells. Methyltransferase inhibition by 5-aza-2\'-deoxycytidine treatment reduced TMZ sensitivity in U251 cells. In U251/TM cells, DNMT1 expression was negatively correlated with miR-20a expression and positively correlated with TMZ sensitivity and leucine-rich repeats and immunoglobulin-like domains 1 expression; these effects were reversed by changes in miR-20a expression. DNMT1 overexpression induced an increase in U251/TM cell apoptosis that was inhibited by the miR-20a mimic, whereas DNMT1 silencing attenuated U251/TM cell apoptosis in a manner that was abrogated by miR-20a inhibitor treatment. Tumor growth of the U251/TM xenograft was inhibited by pcDNA-DNMT1 pretreatment and boosted by DNMT1-small hairpin RNA pretreatment. In summary, DNMT1 mediated chemosensitivity by reducing methylation of the microRNA-20a promoter in glioma cells.
Animals ; Antineoplastic Agents, Alkylating/*pharmacology/therapeutic use ; Apoptosis/drug effects ; Brain/drug effects/metabolism/pathology ; Brain Neoplasms/drug therapy/*genetics/pathology ; DNA (Cytosine-5-)-Methyltransferase/antagonists & inhibitors/*genetics/metabolism ; DNA Methylation ; Dacarbazine/*analogs & derivatives/pharmacology/therapeutic use ; Drug Resistance, Neoplasm ; Female ; Gene Expression Regulation, Neoplastic ; Glioma/drug therapy/*genetics/pathology ; Humans ; Mice, Inbred C57BL ; MicroRNAs/*genetics ; Promoter Regions, Genetic