Objective:To evaluate the role of spinal P2Y1R in the development of remifentanil-induced hyperalgesia in rats with incisional pain (IP) and the relationship with the function of NR1 and NR2B in spinal cord.Methods:Forty-eight healthy adult male Sprague-Dawley rats, aged 10-12 weeks, weighing 250-280 g, in which intrathecal catheters were successfully placed, were divided into 6 groups ( n=8 each) using a random number table method: control group (group C), P2Y1R antagonist MRS2179 group (group M), remifentanil group (group R), remifentanil plus MRS2179 group (group R+ M), IP plus remifentanil group (group I+ R) and IP plus remifentanil plus MRS2179 group (group I+ R+ M). In group C, normal saline 10 μl was intrathecally injected, and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml·kg -1·min -1.In group M, MRS2179 0.6 nmol/kg was intrathecally injected, and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml·kg -1·min -1.In group R, normal saline 10 μl was intrathecally injected, and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1 μg·kg -1·min -1.In group R+ M, MRS2179 0.6 nmol/kg was intrathecally injected, and 10 min later remifentanil was infused for 60 min at a rate of 1 μg·kg -1·min -1 via the tail vein.In group I+ R, normal saline 10 μl was intrathecally injected, 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1 μg·kg -1·min -1, and IP was established at 10 min after onset of remifentanil infusion.In group I+ R+ M, MRS2179 0.6 nmol/kg was intrathecally injected, 10 min later remifentanil was infused via the tail vein for 60 min at a rate of 1 μg·kg -1·min -1, and IP was established at 10 min after onset of remifentanil infusion.The mechanical paw withdrawal threshold (MWT), thermal paw withdrawal latency (TWL), and the number of paw lifts on the cold plate were measured at 24 h before infusion of remifentanil or normal saline and at 2, 6, 24, and 48 h after the end of infusion.The animals were sacrificed after the last measurement of the pain threshold, L 4-6 segments of the spinal cord were removed for determination of the expression of P2Y1R, phosphorylated NR1 (p-NR1), NR1, phosphorylated NR2B (p-NR2B) and NR2B (by Western blot), for calculation of the ratios of p-NR1/NR1 and p-NR2B/NR2B, and for detection of expression of P2Y1R mRNA, NR1 mRNA and NR2B mRNA (by real-time polymerase chain reaction). Results:Compared with group C, MWT was significantly decreased, TWL was shortened, the number of paw lifts on the cold plate was increased, the expression of P2Y1R protein and mRNA, NR1 protein and mRNA, p-NR1, NR2B protein and mRNA and p-NR2B was up-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were increased in group R ( P<0.01). Compared with group R, MWT was significantly increased, TWL was prolonged, the number of paw lifts on the cold plate was decreased, the expression of P2Y1R, p-NR1, NR1 protein and mRNA, p-NR2B, NR2B protein and mRNA was down-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were decreased in group R+ M ( P<0.05 or 0.01). Compared with group I+ R, MWT was significantly increased, TWL was prolonged, the number of paw lifts on the cold plate was decreased, the expression of P2Y1R, p-NR1, NR1 protein and mRNA, p-NR2B, NR2B protein and mRNA was down-regulated, and p-NR1/NR1 ratio and p-NR2B/NR2B ratio were decreased in group I+ R+ M ( P<0.01). Conclusion:Spinal P2Y1R can enhance the function of NR1 and NR2B, which may be involved in the development of remifentanil-induced hyperalgesia in rats with IP.

Objective:To evaluate the role of secreted protein acidic and rich in cysteine like protein 1 (SPARCL1) in spinal dorsal horns in the development of remifentanil-induced hyperalgesia in mice with incisional pain.Methods:Forty-eight healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 6 groups ( n=8 each) using a random number table method: control group (group C), incisional pain group (group I), remifentanil group (group R), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus negative control group (group I+ R+ N), and incisional pain plus remifentanil plus SPARCL1-siRNA group (group I+ R+ S). In I+ R+ N and I+ R+ S groups, 1×10 8 IFU/ml negative control siRNA and SPARCL1-siRNA 10 μl were intrathecally injected, respectively, once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected once a day for 3 consecutive days in C, I, R and I+ R groups.After transfection was stable, normal saline 0.1 ml was intravenously injected through the tail vein for 4 consecutive times at 15 min interval in C and I groups, and remifentanil 10 μg/kg (diluted to 0.1 ml in normal saline) was intravenously injected via the tail vein for 4 consecutive times at 15 min interval in R, I+ R, I+ R+ N and I+ R+ S groups.The incisional pain model was established after the first administration via the tail vein in R, I+ R, I+ R+ N and I+ R+ S groups.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before infusing normal saline or remifentanil (T 0) and 3, 6, 24 and 48 h after stopping infusion (T 1-4). Animals were sacrificed after measuring pain threshold at T 4, and L 4-6 segments of the spinal cord were removed for determination of the expression of SPARCL1 protein and mRNA by Western blot and quantitative real-time polymerase chain reaction, respectively. Results:Compared with group C, MWT was significantly decreased and TWL was shortened at T 1-4 in I+ R and I+ R+ N groups and at T 2-4 in I, R and I+ R+ S groups, and the expression of SPARCL1 protein and mRNA was significantly up-regulated in R, I+ R and I+ R+ C groups ( P<0.05 or 0.01). Compared with group I and group R, MWT was significantly decreased, TWL was shortened, and the expression of SPARCL1 protein and mRNA was up-regulated in group I+ R ( P<0.01). Compared with group I+ R, MWT was significantly increased and TWL was prolonged at T 1-4, and the expression of SPARCL1 protein and mRNA was down-regulated in group I+ R+ S ( P<0.05 or 0.01). Conclusion:Enhanced activity of SPARCL1 in the spinal dorsal horns is involved in the development of remifentanil-induced hyperalgesia in mice with incisional pain.

Objective: To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain. Methods: Forty SPF healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 5 groups (n=8 each) using a random number table method: control group (group C), NL1-shRNA plasmid group (group NL), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus blank vector group (group I+ R+ B), and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+ R+ NL). Negative lentivirus was intrathecally injected in group I+ R+ B.In NL and I+ R+ NL groups, 10 μl NL-1-shRNA lentivirus at 1×10⁸ IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+ R groups.After transfection was stable, normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+ R, I+ R+ B and I+ R+ NL groups, 0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals, and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T₀) and at 3, 6, 24 and 48 h after the end of administration (T_1-4). The animals were sacrificed after measurement of pain threshold at T₄, and L_4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors, and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated. Results: Compared with group C, the MWT was significantly decreased, and TFL was shortened at T_1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated, and m/t ratio was increased in I+ R and I+ R+ B groups (P<0.05). Compared with I+ R and I+ R+ B groups, the MWT was significantly increased and TFL was prolonged at T_1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated, and m/t ratio was decreased in group I+ R+ NL (P<0.05). Conclusion NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane, which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.

Objective: To investigate the prognostic value of metabolic parameters calculated from pretreatment ¹⁸F-fluorodeoxyglucose (FDG) PET/CT images in patients with extranodal natural killer/T cell lymphoma (ENKTL) of stage Ⅰ-Ⅱ. Methods: From August 2010 to April 2018, 67 patients with ENKTL of stage Ⅰ-Ⅱ disease (47 males, 20 females; median age 57 years) in the First Affiliated Hospital of Nanjing Medical University were enrolled, and the clinic data and pretreatment ¹⁸F-FDG PET/CT imaging data were retrospectively analyzed. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of tumor tissue were calculated from PET/CT images with the threshold value of 40% of maximum standardized uptake value (SUV_max). The optimal cut-off values of progression-free survival (PFS) and overall survival (OS) of SUV_max, MTV and TLG were investigated by using receiver operating characteristic (ROC) curve analysis. Kaplan-Meier method, log-rank test and Cox proportional hazards model were used for data analysis. Results: SUV_max, MTV and TLG of 67 patients were 12.32(8.65, 16.96), 13.13(7.37, 22.74) ml, 92.17(46.54, 198.46), respectively. ROC curve analysis showed that the cut-off values of SUV_max, MTV and TLG were 13.09, 18.05 ml and 152.81, respectively. Univariate analysis showed that B symptoms, lactate dehydrogenase (LDH) level, β₂-microglobulin, Eastern Cooperative Oncology Group (ECOG) score, Korean prognostic index (KPI), SUV_max, MTV, TLG and treatment mode (chemotherapy or chemoradiotherapy) were relative factors affecting PFS (χ²: 5.466-27.163, all P<0.05). B symptoms, LDH level, β₂-microglobulin, EB virus (EBV)-DNA, extra-cavitary extension, ECOG score, KPI, MTV, TLG and treatment mode were relative factors affecting OS (χ²: 4.022-34.774, all P<0.05). SUV_max was not the influencing factor of OS(χ²=2.766, P>0.05). Multivariate analysis showed that ECOG score, MTV and TLG were independent prognostic predictors of PFS (relative ratio (RR): 5.107-6.802, all P<0.05), and ECOG score, MTV, TLG and treatment mode were independent prognostic predictors of OS (RR: 0.221-9.106, all P<0.05). Conclusions MTV and TLG from pretreatment ¹⁸F-FDG PET/CT images are independent prognostic factors for PFS and OS in patients with ENKTL of stage Ⅰ-Ⅱ. MTV and TLG may be more useful than SUV_max for prognosis.

Objective To evaluate the relationship between NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors (NR2B receptors) and Ca2+/calmodulin-dependent protein kinase Ⅱ α (CaMK Ⅱ α) in the spinal cord during remifentanil-induced hyperalgesia in a rat model of incisional pain (IP).Methods Forty male Sprague-Dawley rats in which intrathecal and caudal catheters were successfully placed,weighing 260-280 g,aged 2-3 months,were divided into 4 groups (n=10 each) using a random number table method:control group (group C),remifentanil plus IP group (group RI),NR2B antagonist Ro 25-6981 group (group Ro) and remifentanil plus IP plus Ro 25-6981 group (group RI+Ro).In group C,normal saline 0.1 ml was intrathecally injected,and 10 min later normal saline was infused for 60 min via the tail vein at a rate of0.1 ml · kg-1 · min-1.In group RI,normal saline 0.1 ml was intrathecally injected,and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1.0 μg · kg-1 · min-1,and IP was established immediately after onset of remifentanil infusion.In group Ro,Ro 25-6981 (0.1 ml) 10 μg was intrathecally injected,and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml · kg-1 · min-1.In group RI+Ro,Ro 25-6981 (0.1 ml) 10 μg was intrathecally injected,and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1.0 μg · kg-1 · min-1,and IP was established immediately after onset of remifentanil infusion.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before intravenously infusing normal saline or remifentanil and at 2,6,24 and 48 h after the end of infusion (T0-4).The rats were sacrificed after the last behavioral test,and the L4-6 segment of the spinal cord was removed for determination of the expression of NR2B in total and membrane protein (tNR2B and mNR2B) and expression of CaMK Ⅱ α in total protein (tCaMK Ⅱ α) and phosphorylated CaMK Ⅱ α (pCaMKⅡα).The ratios of mNR2B/tNR2B and pCaMKⅡα/tCaMK Ⅱα were calculated.Results Compared with group C,the MWT was significantly decreased,TWL was shortened,the expression of tNR2B,mNR2B,tCaMKⅡα and pCaMKⅡα was up-regulated,and the ratios of mNR2B/tNR2B and pCaMK Ⅱ α/tCaMK Ⅱ α were increased in group RI (P＜0.05 or 0.01).Compared with group RI,the MWT was significantly increased,TWL was prolonged,the expression of tNR2B,mNR2B,tCaMKⅡα and pCaMKⅡα was down-regulated,and the ratios of mNR2B/tNR2B and pCaMK Ⅱ α/tCaMK Ⅱ α were decreased in group RI+ Ro (P＜0.05 or 0.01).Conclusion Enhanced function of NR2B can activate CaMKⅡα during remifentanil-induced hyperalgesia,which may be involved in the mechanism of remifentanil-induced hyperalgesia in a rat model of IP.

Objective To evaluate the changes in the expression of artemin in skin around the inci-sion during remifentanil-induced hyperalgesia in the rats with incisional pain. Methods Thirty-two healthy male Sprague-Dawley rats, aged 10-12 weeks, weighing 250-280 g, were divided into 4 groups (n = 8 each) using a random number table: control group (group C), incisional pain group (group I), remifen-tanil group (group R) and incisional pain plus remifentanil group (group I+R). Remifentanil was intrave-nously infused for 60 min at a rate of 1 μg·kg-1 ·min-1 in group R. In group I, the model of incisional pain was established, and the equal volume of normal saline was infused for 60 min via the tail vein at the same time. In group I+R, the model of incisional pain was established, and remifentanil was infused for 60 min via the tail vein at a rate of 1 μg·kg-1 ·min-1 at the same time. The equal volume of normal saline was infused for 60 min via the tail vein in group C. Mechanical paw withdrawal threshold (MWT) and ther-mal paw withdrawal latency (TWL) were measured at 24 h before infusion of remifentanil or normal saline and 2, 6, 24 and 48 h after the end of infusion (T0-4 ). Rats were sacrificed following the last measurement of pain threshold, and ipsilateral plantar skin was removed for detection of the expression of artemin protein and mRNA (by fluorescent quantitative real-time polymerase chain reaction or Western blot). Results Compared with group C, MWT was significantly decreased and TWL was shorten at T1-4 , and the expression of artemin protein and mRNA in plantar skin was up-regulated in R, I and I+R groups (P<0. 01). Compared with R and I groups, MWT was significantly decreased and TWL was shorten at T1-4 , and the ex-pression of artemin protein and mRNA in plantar skin was up-regulated in group I+R (P<0. 01). Conclu-sion The peripheral mechanism by which remifentanil induces hyperalgesia may be related to up-regulated expression of artemin in skin around the incision in the rats with incisional pain.

Objective To evaluate the role of spinal C-C motif chemokine receptor 5 (CCRS) in remifentanil-induced hyperalgesia in rats with incisional pain.Methods Thirty-two male Sprague-Dawley rats,weighing 240-260 g,aged 2-3 months,in which intrathecal and caudal catheters were successfully implanted,were divided into 4 groups (n =8 each) using a random number table:control group (group C),CCR5 antagonist maraviroc group (group M),remifentanil plus incisional pain group (group R + I) and maraviroc plus remifentanil plus incisional pain group (group M + R + I).Phosphate buffer solution (PBS) 10 μl was intrathecally injected and normal saline was infused for 60 rnin at 1 μg · kg-1 · min-1 via the caudal vein in group C.Maraviroc 100 pmol (in 10 μl of PBS) was intrathecally injected and normal saline was infused for 60 min at 1 μg · kg-1 · min-1 via the caudal vein in group M.PBS 10 μl was intrathecally injected,then the model of incisional pain was established,and remifentanil 1 μg · kg-1 · min-1 was infused for 60 min via the caudal vein in group R+I.Maraviroc 100 pmol (in 10 μl of PBS) was intrathecally injected,then the model of incisional pain was established,and remifentanil 1 μg · kg-1 · min-1 was infused for 60 min via the caudal vein in group M+R+I.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before infusion of remifentanil or normal saline (T0) and 2,6,24 and 48 h after stopping infusion (T1-4).The rats were sacrificed after the last measurement of pain threshold,and L4-6 segments of the spinal cord were removed for determination of the expression of glial fibrillary acidic protein (GFAP) and ionized calciumbinding adapter molecule-1 (Iba-1) by Western blot.Results Compared with group C,the MWT was significantly decreased and TWL was shortened at T1-4,and the expression of GFAP and Iba-1 in the spinal cord was up-regulated in R+I and M+R+I groups (P＜0.05),and no significant change was found in the parameters mentioned above in group M (P＞0.05).Compared with group R+I,the MWT was significantly increased and TWL was prolonged at T1-4,and the expression of GFAP and Iba-1 in the spinal cord was down-regulated in group M+R+I (P＜0.05).Conclusion Spinal CCR5 is involved in remifentanil-induced hyperalgesia in the rats with incisional pain,and the mechanism may be related to activating astrocytes and microglias.

Objective To evaluate the effect of dexmedetomidine on necroptosis during liver injury in septic rats.Methods Eighteen SPF adult male Sprague-Dawley rats,weighing 200-220 g,were divided into 3 groups (n=6 each) using a random number table:sham operation group (group SH),sepsis group (group SEP) and dexmedetomidine group (group DEX).Sepsis was induced by cecal ligation and puncture in chloral hydrate-anesthetized rats in SEP and DEX groups.Dexmedetomidine 5 μg/kg was injected via the caudal vein at 1 h before operation in group DEX.Blood samples were collected from the caudal vein at 6 h after operation for determination of serum aspartate amino-transferase (AST) and alanine aminotransferase (ALT) concentrations.The rats were then sacrificed and livers were removed for determination of the level of reactive oxygen species (ROS) in liver tissues (using chemiluminescence assay) and expression of receptor-interacting protein 1 (RIP1),RIP3,mixed lineage kinase domain-like (MLKL),high-mobility group box 1 protein (HMGB1) and dynamin-related protein 1 (Drpl) in liver tissues (by Western blot).Results Compared with group SH,the serum AST and ALT concentrations were significantly increased,the expression of RIP1,RIP3,MLKL,HMGB1 and Drpl in liver tissues was up-regulated,and the level of ROS in liver tissues was increased in SEP and DEX groups (P＜0.05).Compared with group SEP,the serum AST and ALT concentrations were significantly decreased,the expression of RIP1,RIP3,MLKL,HMGB1 and Drp1 in liver tissues was down-regulated,and the level of ROS in liver tissues was decreased in group DEX (P＜0.05).Conclusion The mechanism by which dexmedetomidine attenuates liver injury may be related to inhibition of necroptosis in septic rats.

Objective To evaluate the changes in natural Killer (NK) cell subsets definetd by CD11b and CD27 in the spleen of septic mice.Methods A total of 168 pathogen-free healthy male C57BL/6 mice,weighing 20-30 g,aged 8-10 weeks,were divided into 2 groups (n=84 cach) using a random number table:sham operation group (Sham group) and sepsis group (Sep group).Sepsis was induced by cecal ligation and puncture in chloral hydrate-anesthetized mice.Thirty mice in each group were selected to assess the survival within 4 days after operation,and the survival rate was calculated.At 2,4,6,24,48 and 72 h after operation (T1-6),6 mice were randomly selected,and blood samples were taken from the eyeballs for determination of serum tumor necrosis factor-alpha and interleukin-10 concentrations by enzyme-linked immunosorbent assay.Six mice were randomly selected at T4-6 and sacrificed,and the spleens were removed for measurement of the percentage of NK cells and their subsets by flow cytometry.Results Compared with Sham group,the survival rate was significantly decreased at different time points,the serum necrosis factor-alpha concentration at T1-3,6 and serum interleukin-10 concentration at T3-6 were increased,the percentage of NK cells was decreased at T4-6,the percentage of CD27-CD11b+NK cells was decreased and the percentage of CD27+CD11b+ and CD27+CD11b-NK cells was increased at T5,the percentage of CD27-CD11b-NK ceils was decreased at T4,5,and the percentage of CD27-CD11b-NK cells was increased at T6 in Sep group (P＜0.05).Conclusion Changes in NK cell subsets defined by CD11b and CD27 in the spleen play an important role in the development of sepsis in mice.

Objective To evaluate the role of necroptosis in liver injury in septic rats.Methods Twenty-four SPF healthy male adult Sprague-Dawley rats,weighing 200-220 g,aged 6-8 weeks,were divided into 3 groups (n=8 each) using a random number table:sham operation group (Sh group),sepsis group (Sep group) and specific necroptosis inhibitor necrostatin-1 group (N group).Sepsis was induced by cecal ligation and puncture in anesthetized rats in N and Sep groups.Necrostatin-1 1.0 mg/kg was intravenously injected at 1 h before operation in group N,while the equal volume of dimethyl sulfoxide was given instead in group Sep.Rats were sacrificed at 6 h after operation,and livers were removed for examination of the pathological changes (with a light microscope) and for determination of the level of reactive oxygen species (ROS) in liver tissues (by using chemiluminescence assay) and expression of receptor-interacting protein kinase-1 (RIPK1),RIPK3,mixed lineage kinase domain-like (MLKL) and high-mobility group box 1 protein (HMGB1) in liver tissues (using Western blot).Results Compared with Sh group,the ROS level in liver tissues was significantly increased,and the expression of RIPK1,RIPK3,MLKL and HMGB1 in liver tissues was up-regulated in Sep and N groups (P＜0.05).Compared with Sep group,the ROS level in liver tissues was significantly decreased,and the expression of RIPK1,RIPK3,MLKL and HMGB 1 in liver tissues was down-regulated in group N (P＜0.05).The pathological changes of liver tissues were significantly attenuated in group N when compared with group Sep.Conclusion Neeroptosis is involved in liver injury in septic rats.