Objective To investigate the value of dual-phase 18F-FDG PET/CT for differentiating pancreatic cancer from pancreatitis.Methods Dual-phase 18F-FDG PET/CT scanning was prospectively performed on patients with suspicious pancreatic lesions.Patients with solid focal pancreatic lesions proved by histopathology or clinical follow-up were enrolled and divided into 3 groups according to the maximum diameter of the focus: ≤2.0 cm (group A), >2.0 cm and ≤ 4.0 cm (group B), >4.0 cm (group C).SUVmax at (60±10) min and (120±15) min after FDG injection was defined as early and delayed SUVmax (SUVearly and SUVdelayed), respectively, and retention index (RI) was calculated.The differences of SUVearly, SUVdelayed and RI between pancreatic cancer and pancreatitis were analyzed with Mann-Whitney u test.ROC curve was used to determine the optimal cutoff values of the above three parameters and corresponding diagnostic efficiencies were obtained.The AUC was compared with MedCalc software.Results A total of 196 patients (152 pancreatic cancers and 44 pancreatic inflammatory lesions) with solid focal pancreatic lesions were enrolled.The AUC of SUVdelayed was significantly larger than that of SUVearly (0.83 vs 0.79, z=3.64, P<0.01).Numbers of patients in group A, B and C were 45, 96 and 55 respectively.There was no significant difference of the maximum diameter between pancreatic cancers and pancreatitis lesions in all three groups (z values:-0.39,-1.52,-1.41, all P>0.05).The SUVearly, SUVdelayed and RI of pancreatic cancers were all higher than those of pancreatitis in group A and B (z values: from-4.59 to-3.00, all P<0.01).The diagnostic sensitivity and accuracy of SUVearly > 3.6 combined with RI > 0 for diagnosing pancreatic cancer were higher than those of SUVearly > 3.6: 96.4%(27/28) vs 75.0%(21/28), 95.6%(43/45) vs 82.2%(37/45).The AUC of SUVdelayed was significantly larger than that of SUVearly in group B (0.81 vs 0.77, z=2.06, P<0.05).The optimal cutoff value of SUVdelayed in group B was 5.3, with the corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 84.4%(65/77), 13/19, 91.5%(65/71), 52.0%(13/25) and 81.2%(78/96), respectively.RI of pancreatic cancers was significantly higher than that of pancreatitis (25.0%(15.8%-35.7%) vs 14.4%(4.6%-18.7%), z=-2.39, P<0.05) in group C.The optimal cutoff value of RI in group C was 19.0%, with the corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 68.1%(32/47), 7/8, 97.0%(32/33), 31.8%(7/22) and 70.9%(39/55).Conclusions The SUVdelayed and RI of dual-phase 18F-FDG PET/CT might be useful for diagnosis of pancreatic tumors.SUVearly > 3.6 combined with RI >0 could be helpful to improve the diagnostic sensitivity and accuracy in patients with the maximum diameter of lesions ≤2.0 cm.The diagnostic value of SUVdelayed might be better than that of SUVearly in patients with the maximum tumor diameter of >2.0 cm and ≤4.0 cm.Only RI could be used for diagnosing pancreatic tumors in patients with the maximum tumor diameter > 4.0 cm.

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 evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain. Methods: Thirty-two male C57BL/6J mice, aged 8-10 weeks, weighing 20-25 g, were divided into 4 groups (n=8 each) using a random number table method: control group (group C), incisional pain plus remifentanil group (group IR), incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+ SC560), and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+ SC236). In IR, IR+ SC560 and IR+ SC236 groups, normal saline 10 μl, SC560 25 μg and SC236 25 μg were intrathecally injected, respectively, 15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3, 6, 24 and 48 h after the last injection (T₀-T₄). The mice were sacrificed after the last measurement of pain threshold, and the L_4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot) and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction). Results: Compared with group C, the MWT was significantly decreased, and the expression of COX-2 protein and mRNA was up-regulated in IR, IR+ SC560 and IR+ SC236 groups (P<0.05). Compared with group IR, the MWT was significantly increased in IR+ SC560 and IR+ SC236 groups (P<0.05). There was no significant difference in the MWT at each time point between IR+ SC560 and IR+ SC236 (P>0.05) .There was no significant difference in the expression of COX-2 protein and mRNA among group IR, group IR+ SC560 and group IR+ SC236 (P>0.05). There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P>0.05). Conclusion Compared with COX-1, spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.

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.