Objective To investigate the effects of different doses of intrathecal magnesium on bone cancer pain (BCP) in mice.Methods Two hundred and eighty-eight male C3H/HeJ mice,aged 8-10 weeks,weighing 18-22 g,were randomly divided into 6 groups (n =48 each):control group (group C) ; sham operation group (group S) ; BCP + artificial cerebro-spinal fluid (aCSF) 5 μl group (group BCP) ; BCP + MgSO4 14.4 μg group (group M1 ) ; BCP + MgSO4 43.2 μg group (group M2 ) and BCP + MgSO4 86.4 μg group (group M3 ).BCP was produced by injecting fibrosarcoma cells of bone into the medullary cavity of right femur.Intrathecal catheter was placed in the 4 BCP groups.The aCSF 5 μl or MgSO4 14.4μg/5 μl,43.2 μg/5 μl,or 86.4μg/5 μl was injected intrathecally on 14th day after inoculation of tumor cells.The paw withdrawal threshold to mechanical stimuli (PWMT) and paw withdrawal lateney to thermal stimuli (PWTL) were measured at 0.5 h before administration (T0 ) and at 0.5,2,4 and 8 h after administration (T1-4).Eight animals chosen from each group at T0-4 were sacrificed,and L4-5 segment of the spinal cord was removed for determination of NR2B expression (by immuno-flurorescence) in the spinal cord.Results PWMT and PWTL were significantly decreased at T0-4,and NR2B expression was significantly up-regulated at T0-4 in groups BCP,M1,M2,M3 compared with groups C and S ( P ＜0.05).Compared with group BCP,PWMT and PWTL were significandy increased at T1-3,and NR2B expression was significantly down-regulated at T1-3 in groups M2 and M3 ( P ＜ 0.05).Compared with group M2,PWMT and PWTL were significantly increased at T1-3,and NR2B expression was significantly down-regulated at T1-3 in group M3 ( P ＜ 0.05).Conclusion Intrathecal magnesium can reduce BCP in a dose-dependent manner in mice.

Objective To systematically review the preventive efficacy of N-methyl-D-aspartate (NMDA) receptor antagonists on remifentanil-induced postoperative hyperalgesia.Methods Pubmed,EMBase,Springer and Cochrane Controlled Trials Register were searched to identify all randomized controlled trials(RCTs) about efficacy of NMDA receptor antagonists for preventing remifentanil-induced postoperative hyperalgesia.The quality of the studies was evaluated by the method recommended by Cochrane Collaboration.The data was extracted,including postoperative analgesic consumption,pain scores,time for first analgesic request and the incidence of adverse effects.Meta-analysis was conducted using the Cochrane Collaboration's RevMan 5.0 software.Results Fourteen RCTs involving 623 patients were included in our Meta-analysis.NMDA receptor antagonists significantly decreased pain scores at 4 h after operation ( P ＜ 0.05),and had no effect on postoperative analgesic consumption,time for first analgesic request and the incidence of adverse effects ( P ＞ 0.05).Conclusion NMDA receptor antagonists (ketamine and magnesium)can not prevent the occurrence of postoperative hyperalgesia induced by remifentanil.

ObjectiveTo investigate the effect of intrathecal injection of magnesium sulfate ( MgSO4 ) on pain behavior in mouse with bone cancer pain.Methods56 male 8-10 week old C3H/HeJ mice weighing 18-22 g were divided randomly into 7 groups ( n =8 ):sham group (S group),control group (C group) and MgSO4 plus morphine treat groups( T1-T5 group).Croup C and T mice were induced bone cancer pain models by intra-rightfemur inoculation of osteolytic NCTC2472 cells while group S were injected of only α-MEM.On the 14d after inoculation,group S and C received intrathecal injection of artificial cerebrospinal fluid 5 μl,while group T1-T5 received intrathecal injection of MgSO4 14.4 μg,43.2 μg,86.4 μg,morphine 0.36 μg,MgSO4 14.4 μg-morphine 0.36 μg,which were dissolved in 5 μl artificial cerebrospinal fluid.Micc received pain behavior tests including quantification of spontaneous flinches,paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) at 0.5h before and 0.5h,2h,4h,gh after administration.ResultsTreatment with MgSO4 (14.4 μg),morphine (0.36 μg) have no effect on bone cancer pain,while treatment with MgSO4 (43.2 μg,86.4 μg)can dose-dependently reverse quantification of spontaneous flinches,mechanical allodynia and thermal hypcralgesia which were induced by inoculation as well as MgSO4 14.4 μg-morphine 0.36 μg.At 0.5 h after administration,the quantification of spontancous flinches of the three groups( ( 10.08 ± 1.66),(7.35 ± 1.36),( 10.54 ± 1.32 ) ) were decrcased when compared with control group ( 13.05 ± 2.06 ),PWMT ( (0.81 ± 0.22 ) g; ( 1.33 ± 0.19)g; (0.93 ±0.26)g),PWTL( (10.57 ±1.53)s; (13.12 ±1.71)s; (11.46 ±1.83)s) were increased when compared with control group ( (0.42 ± 0.23 ) g,( 8.87 ± 1.27 ) s) (P ＜ 0.05 ).The effect reached maximum level at 2h,lasted for at least 4h and disappeared at 8h.ConclusionIntrathecal injection MgSO4 can effectively attenuate bone cancer pain dose-dependently.At the same time MgSO4 can amplify the analgesic effect of subliminal morphine.

Objective To investigate effects of metabotropic glutamate receptor subtype 5 (mGluR5) antagonist MTEP on the nociceptive behavior and the expression of glial fibrillary acidic protein (GFAP) in spinal cord associated with bone cancer pain. Methods C3H/HeNCrlVr 60 male mice were randomly divided into 5 groups: ( 1 ) normal control group: the mice were given food and water ad libitum; ( 2 ) MTEP + Tumor group: the mice were treated by intrathecal gdministration ( once daily on the days 14 ～20 after inoculation of tumor cells)with MTEP (150 nmol); (3) physiological saline + Tumor group:the tumor mice were treated with the same volume of physiological saline; (4) MTEP + Sham group: the sham mice were treated with the same dose of MTEP;(5) physiological saline + Sham group: the sham mice were treated with the same volume of physiological saline.the mice pain behaviors were assessed with the paw withdrawal thermal latency (PWTL) at the corresponding time points, then the mice were killed and the samples of spinal cord were used to real-time PCR and western blot detection of GFAP mRNA and protein expression. Results The basic values of PWTL had no significant differences among all groups (P＜0.05). At day 14 after operation,no significant difference was found in the PWTL value between normal control group and the sham operation group. But in tumor group, the PWTL value was significantly lower than in the normal control group (P＜ 0.05 ). At day 21 after operation,the PWTL and the level of GFAP expression in the spinal cord had no significant differences among normal control group, MTEP + Sham group and physiological saline + Sham group (P ＞ 0.05 ); the PWTL ( (6. 18 ± 1.29 ) s) in physiological saline + Tumor group was significantly lower than in normal control group ( ( 15.91 ± 1.65 )s), physiological saline + Sham group ( ( 16.57 ± 1.86) s) and MTEP + Sham group ( ( 17.05 ± 2.43 ) s) (P ＜ 0.05 ), but the level of GFAP expression was higher than in the above three groups. In MTEP +Tumor group ,the PWTL (9.39 ± 1.94s) was higher than in physiological saline + Tumor group, and the level of GFAP expression was lower than in physiological saline +Tumor group (P ＜ 0.05 ). Conclusion Inhibiting spinal activation of astrocytes may be one of the MTEP anticancer pain mechanisms.

Objective To investigate the effect of intraperitoneal injection of thalidomide on pain behaviors in a mouse model of bone cancer pain. Methods 36 male C3H/HeJ mice were divided randomly into tumor group (n= 18) and sham group (n= 18) ,six mice from each group were chosen to examine the time course of changes in behavior after tumor cells inoculated to the bone. 2 × 105 osteosarcoma NCTC 2472 cells were implanted into the intramedullary space of the right femurs of mice to induce ongoing bone cancer related pain behaviors. The sham group was inoculated by α-MEM without any cells. On the day before inoculation,the tumor mice were divided randomly into tumor + thalidomide group and tumor + vehicle group. The sham group mice were further divided randomly into sham + thalidomide group and sham + vehicle group. Pain ethology indexes such as paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were observed on 1 d before inoculation and on 3 d ,5 d ,7 d, 10 d, 14 d after inoculation. Results ( 1 ) At day 7 after the operation, compared with sham mice ( 1. 70 ± 0. 33 ) g, PWMT of tumor mice decreased to ( 1.07 ± 0. 30) g (P ＜ 0. 05 ). At day 10, PWTL shortened to ( 12.60 ± 1.69 ) s (P ＜ 0. 05 ) compared with sham mice ( 17.70 ± 1.54 ) s. And the pain behaviors of tumor mice were aggravated along with the development of cancer pain. (2) At day 7 after the operation, compared with tumor + vehicle group ( 1. 07 ± 0.39 ) g, PWMT of tumor + thalidomide group increased to ( 1. 53 ± 0. 39 ) g (P ＜0.05). At day 10, PWTL extended to ( 16.48 ± 1.13 ) s compared with sham mice ( 12.64 ± 1. 56) s (P ＜0. 05 ). Conclusion Intraperitoneal injection of thalidomide can efficiently relieve mechanical hyperalgia and thermal hyperalgia in a mouse model of bone cancer pain.

Objective To investigate the effects of continuously intrathecal injection rapamycin on neuro pathic pain behaviors in mice.Methods 48 male adult C57/BL6 mice received intrathecal catheter implantation successfully and without motor dysfunction and serious weight loss,were choosed and randomly divided into shamoperation group ( sham,n =24) and chronic constriction injury model group ( CCI,n =24 ).After operation,each group randomly divided into 3 group again.Group I did nothing,group Ⅱ intrathecally injected rapamycin 1 μg/5μlon day 1 to 6 after operation,group Ⅲ intrathecally injected 20％ DMSO 5μl on the same time ( sham,CCI,sham +R,sham + V,CCI + R,CCI + V,n =8 ).Bilateral mechanical paw withdrawal threshold (WMT) and thermal paw withdrawal latency(TWL) were tested on day 1 before CCI and day 1,3,5,7,10,14,17,21,28 after operation.Results Compared with sham group,both WMT and TWL (7d,MWT:( 1.02 ±0.12)g vs (0.42 ±0.12)g,F=51.01,P＜0.05;TWL:(7.03 ±0.71 )s vs (3.26 ±0.66)s,F=38.27,P＜0.05) were significantly decreased after CCI on the ipsilateral side.When intrathecally injected Rapamycin 1 μg/5 μl on day 1 ～6 after CCI,the mechanical allodynia relieved obviously ( 7 d,M WT:( 0.42 ± 0.18 ) g vs ( 0.86 ± 0.25 ) g,F =6.56,P ＜ 0.05 ),and at least continued to 10 d.On the contrary,the effects of rapamycin on thermal hyperalgesia just showed a trend of inhibition,there was no statistic meaning.In addition,the sham group and contralateral pain behaviors did not change (P＞ 0.05 ).Conclusion Rapamycin can relieve the neuropathic pain behaviors in mice after CCI,mainly the mechanical allodynia,but not thermal hyperalgesia.

Objective: To explore the effect of calcium channel blocker (CCB) treatment in patients of idiopathic pulmonary arterial hypertension (IPAH) with positive acute pulmonary vasodilator test, and to compare the hemodynamic differences between the positive and negative patients.
Methods: A total of 156 consecutive IPAH patients with acute pulmonary vasodilator test were studied. The patients were divided into 2 groups according to the testing result. Positive group, n=23 and Negative group, n=133. The positive patients were followed up by clinical or telephone visit to investigate their CCB dose, WHO PAH cardiac classiifcation and the survival conditions. Kaplan-meier curve was conducted to analyze the living condition and t test was used to compare the hemodynamic differences between the positive and negative patients.
Results: There were 43 male and 113 female patients at the male/female ratio of 1: 2.6, and 14.7% (23/156) positive patients. The average follow-up period for Positive group was (50.9 ± 3.8) months. There were 13 patients using diltiazem with the mean dose of (277 ± 108) mg/d at the range of (90-450) mg/d; 3 patients using amlodipine, 1 with the dose of 15mg/d and 2 with the dose of 7.5mg/d. The 1, 2 and 3 years survival rate for the positive patients were for 91.3%, 86.6% and 79.7% respectively. The mean pulmonary arterial pressure and pulmonary vascular resistance were lower, P=0.000, while the mixed venous oxygen saturation was higher in Positive group than Negative group, P=0.009.The NT-pro BNP level was lower in Positive group, P=0.001.
Conclusion: IPAH patients has lower ratio of positive acute pulmonary vasodilator test. The positive patients has the higher 1, 3 and 5 years survival rate and better hemodynamic parameters as the mean pulmonary arterial pressure, pulmonary vascular resistance and better level of NT-pro BNP.