Objective To investigate the effects of protocadherin 20 (PCDH20) in the spinal cord in the development of bone cancer pain (BCP) in rats.Methods Thirty-six SPF female Sprague-Dawley rats,weighing 180-200 g,were randomly divided into 4 groups (n =9 each):sham operation group (group S),BCP group,lentivirus control group (group LC) and PCDH20 siRNA lentivirus group (group P).Control lentivirus and lentivirus containing PCDH20 siRNA 4 μl were injected into the ipsilateral spinal cord in groups LC and P,respectively.One week later,BCP was induced by injection of Walker 256 breast cancer cells into the upper segment of bone marrow of right tibia.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before injection of lentivirus (T1),1 day before BCP (T2),and 7,14 and 21 days after BCP (T3-5).Three rats in each group were sacrificed after measurement of the MWT at 21 day after BCP and the tibia on the operated side was obtained for examination of invasion of the cancer cells with light microscope.The spinal cord was removed for determination of the expression of PCDH20 and postsynaptic density 95 (PSD95) protein (by Western blot) and mRNA (by RTPCR).Results In groups BCP,LC and P,the cancer cells grew out of the bone and destroyed the cortical bone seriously.Compared with group S,the MWT was significantly decreased at T3-5 in groups BCP,LC and P,the expression of PCDH20 and PSD95 protein and mRNA was up-regulated in groups BCP and LC,and the expression of PCDH20 was up-regulated in group P (P ＜ 0.05).Compared with BCP group,no significant change was found in the MWT and expression of PCDH20 and PSD95 protein and mRNA in group LC (P ＞ 0.05),and the MWT was significantly increased at T4,5 and the expression of PCDH20 and PSD95 protein and mRNA was down-regulated in group P (P ＜ 0.05).Conclusion PCDH20 is involved in the development of BCP through regulating the expression of PSD95 in the spinal cord and adjusting the function of excitatory synapse in rats.

Objective To investigate the change in 5-hydroxytryptomine (5-HT) content in spinal dorsal horn in a rat model of tibial bone cancer pain (BCP). Methods Sixty female SD rats weighing 160-180 g were randomly divided into 3 groups ( n = 20 each): control group (group C), sham operation group (group S) and BCP group. BCP was induced by intra-tibial inoculation of 10 μl Walker 256 breast cancer cell suspension in group BCP, while group S received intra-tibial inoculation of 10 μl D-hank solution. Paw withdrawal threshold to mechanical stimulation with yon Frey filaments (MWT) was measured 1 d before (baseline) and at 3, 5, 7, 9, 11,14, 16, 18 and 21 d after breast cancer cell inoculation. At 1 d before and 7, 14 and 21 d after breast cancer cell inoculation, four animals in each group were sacrificed after measurement of MWT. Their lumber segments of the spinal cord were removed for assay of 5-HT content in spinal dorsal horn using HPLC with fluorescence detector.HE staining was used to detect the damage to the tibia. Correlation between the 5-HT content and MWT was analyzed. Results MWT was significantly decreased after breast cancer cell inoculation in group BCP ( P ＜ 0.05).Microscopic examination showed serious bone destruction of tibia at the injection site in group BCP, while no bone destruction was found in groups C and S. 5-HT content in spinal dorsal horn was significantly higher in group BCP than in groups C and S (P ＜ 0.05). There was strong negative linear correlation between 5-HT content in spinal dorsal horn and MWT ( r = - 0.973, P ＜ 0.05 ). Conclusion The 5- HT content in spinal dorsal horn is significantly increased in rats with tibial BCP and is involved in the development of BCP.

Objective To construct lentivirus vector expressing antigene RNA and ferritin gene.Methods Intermediate plasmid pGC-FU-HF was constructed by transfecting lentivirus vector pGC-FU with heavy chain ferritin subunit gene.The target plasmid pGC-agRNA-HF was subsequently constructed by transfecting the intermediate plasmid with β-arrestin 2 antigene RNA.The NG108-15 cells were transfected with the target plasmid.The titre of lentivirus vector was measured by RT-PCR.The expression of antigene RNA and ferritin gene was determined by Western blot and RT-PCR.Results Lentivirus vector was successfully transfected with antigene RNA and ferritin gene.The titre of lentivirus vector was 2.00 × 109 TU/ml.The expression of β-arrestin2 protein was down-regulated and the expression of ferritin protein up-regulated in the NG108-15 cells after being transfected with the lentivirus vector.Conclusion Lentivirus vector expressing antigene RNA and ferritin gene has been successfully constructed.

Descending nociceptive modulation from the supraspinal structures plays an important role in cancer-induced bone pain (CIBP). Rostral ventromedial medulla (RVM) is a critical component of descending nociceptive facilitation circuitry, but so far the mechanisms are poorly known. In this study, we investigated the role of RVM glial activation in the descending nociceptive facilitation circuitry in a CIBP rat model. CIBP rats showed significant activation of microglia and astrocytes, and also up-regulation of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) and pro-inflammatory mediators released by glial cells (IL-1β, IL-6, TNF-α and brain-derived neurotrophic factor) in the RVM. Stereotaxic microinjection of the glial inhibitors (minocycline and fluorocitrate) into CIBP rats' RVM could reverse the glial activation and significantly attenuate mechanical allodynia in a time-dependent manner. RVM microinjection of p38 MAPK inhibitor (SB203580) abolished the activation of microglia, reversed the associated up-regulation of pro-inflammatory mediators and significantly attenuated mechanical allodynia. Taken together, these results suggest that RVM glial activation is involved in the pathogenesis of CIBP. RVM microglial p38 MAPK signaling pathway is activated and leads to the release of downstream pro-inflammatory mediators, which contribute to the descending facilitation of CIBP.

Objective To evaluate the efficacy of ultrasound-guided erector spinae plane (ESP) block for postoperative analgesia in the patients undergoing video-assisted thoracoscopic pulmonary lobecto-my by comparing with paravertebral nerve block. Methods Ninety patients of both sexes, aged 18-64 yr, with body mass index of 20- 27 kg∕m2 , of American Society of Anesthesiologists physical statusⅠ-Ⅲ, scheduled for elective video-assisted thoracoscopic pulmonary lobectomy, were divided into 2 groups (n= 45 each) using a random number table: ultrasound-guided paravertebral nerve block ( group P) and ultra-sound-guided ESP block group (group E). Morphine 0. 1 mg∕kg and parecoxib sodium 40 mg were intrave-nously injected at 30 min before surgery. Ultrasound-guided ESP and paravertebral nerve blocks were per-formed with 0. 5％ ropivacaine 20 ml after anesthesia induction in E and P groups, respectively. Both groups received patient-controlled intravenous analgesia with 0. 1％ morphine 100 ml after surgery, and the analgesia pump was set up with a 1 ml bolus dose, 8 min lockout interval and no background infusion. Parecoxib 40 mg was intravenously injected every 8 h. Operation time, anesthesia time and total consumption of intraoperative remifentanil were recorded. The operation time of nerve block and development of pleu-ral puncture and vascular injury during operation were also recorded. The cumulative consumption of mor-phine was recorded at 2, 4, 6, 24 and 48 h after surgery. The development of postoperative nausea and vomiting and respiratory depression was recorded. Tramadol 100 mg was intramuscularly injected as a rescue analgesic when the visual analog scale score was more than 3. Results The operation time of nerve block was significantly shorter in group E than in group P (P<0. 05). There was no significant difference in the total consumption of intraoperative remifentanil, cumulative consumption of morphine, incidence of nausea and vomiting or requirement for rescue analgesia between two groups (P>0. 05). Pleural puncture, vascu-lar injury, pruritus or respiratory depression was not found in two groups. Conclusion Ultrasound-guided ESP block provides better analgesic efficacy after operation than paravertebral nerve block in the patients un-dergoing video-assisted thoracoscopic pulmonary lobectomy.

Objective To evaluate the effect of ultrasound-guided erector spinae plane block combined with general anesthesia on early postoperative outcome in patients undergoing video-assisted thoracoscopic pulmonary lobectomy.Methods Eighty-five patients of both sexes,aged 18-64 yr,with body mass index of 18-24 kg/m2,of American Society Anesthesiologists physical status Ⅱ or Ⅲ,undergoing elective video-assisted thoracoscopic pulmonary lobectomy,were divided into 2 groups using a random number table method:general anesthesia group (group GA,n =43) and ultrasound-guided erector spinae plane block combined with general anesthesia group (group ESP+GA,n =42).Ultrasound-guided erector spinae plane block was performed after induction of general anesthesia,0.5％ ropivacaine 20 ml was injected in group ESP+GA,and 0.9％ normal saline 20 ml was injected in group GA.Both groups received patient-controlled intravenous analgesia with sufentanil after surgery.Tramadol was intramuscularly injcted as resue analgesic when visual analog scale score＞3.Quality of Recovery-40 questionnaire was used to assess the early postoperative quality of recovery at 1 day before surgery and 1 and 2 days after surgery.The consumption of intraoperative remifentanil and postoperative sufentanil,requirement for rescue analgesics and occurrence of postoperative adverse reactions were recorded.Results Compared with group GA,the Quality of Recovery-40 questionnaire scores were significantly increased at 1 and 2 days after surgery,the consumption of intraoperative remifentanil and postoperative sufentanil was reduced,and the requirement for rescue analgesics and incidence of nausea and vomiting were decreased in group ESP+GA (P＜0.05).Conclusion Ultrasoundguided erector spinae plane block combined with general anesthesia can promote early postoperative outcome in patients undergoing video-assisted thoracoscopic pulmonary lobectomy.

Objective To evaluate the efficacy of ultrasound-guided quadratus lumborum block for analgesia after laparoscopic cholecystectomy. Methods Sixty American Society of Anesthesiologists physi-cal statusⅠorⅡ patients, aged 18-64 yr, with body mass index of 20-27 kg∕m2 , scheduled for elective laparoscopic cholecystectomy, were divided into 2 groups ( n=30 each) using a random number table meth-od: ultrasound-guided transversus abdominis plane block group ( group T) and ultrasound-guided quadratus lumborum block group (group Q). In T and Q groups, bilateral ultrasound-guided transversus abdominis plane block and quadratus lumborum block were performed after general anesthesia induction, respectively, with 0. 25％ ropivacaine 20 ml for each side. All the patients received patient-controlled intravenous analge-sia with morphine after surgery, and visual analoge scale scores were maintained≤3 in the two groups. The cumulative consumption of morphine was recorded at 2, 4, 6, 12, 24 and 48 h after surgery. The occur-rence of adverse reactions such as nausea, vomiting, pruritus, over-sedation and respiratory depression was observed and recorded in the analgesic period. The operation time for nerve blocks and nerve blocks-related complications such as bleeding, accidental puncture into the abdominal cavity or intestinal injuries were re-corded. Results Compared with group T, the cumulative consumption of morphine was significantly de-creased at 6, 12, 24 and 48 h after surgery in group Q ( P<0. 05) . There was no significant difference in the operation time for nerve blocks between the two groups ( P>0. 05 ) . There were no adverse reactions such as nausea, vomiting, pruritus, over-sedation and respiratory depression or nerve blocks-related compli-cations in the two groups. Conclusion Ultrasound-guided quadratus lumborum block provides better effica-cy than transversus abdominis plane block when used for analgesia after laparoscopic cholecystectomy.

Objective To evaluate the effect of dexmedetomidine on the expression of Semaphorin 7A during lung ischemia-reperfusion (I/R) in rats.Methods Thirty healthy clean-grade adult male Sprague-Dawley rats,aged 8-12 weeks,weighing 200-240 g,were divided into 3 groups (n=10 each) using a random number table method:sham operation group (S group),I/R group and dexmedetomidine group (D group).Only sternotomy was performed,and the left hilum of lung was not clamped in S group.The model of lung I/R injury was established by clamping the left hilum of lung for 45 min followed by 120 min of reperfusion in I/R group.Dexmedetomidine 50 μg/kg was intraperitoneally injected at 30 min before ischemia,and then the model was established in D group.The rats were sacrificed at the end of reperfusion,and the lungs were removed for examination of the pathological changes (using haematoxylin and eosin staining) which were scored and for determination of the wet to dry weight ratio (W/D ratio),expression of Semaphorin 7A protein and mRNA (by Western blot or real-time polymerase chain reaction),and contents of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) in lung tissues (by enzyme-linked immunosorbent assay).Results Compared with S group,W/D ratio and pathological scores were significantly increased,the expression of Semaphorin 7A protein and mRNA was up-regulated,and the contents of TNF-α and IL-1β were increased in I/R and D groups (P＜0.05).Compared with I/R group,W/D ratio and pathological scores were significantly decreased,the expression of Semaphorin 7A protein and mRNA was down-regulated,and the contents of TNF-α and IL-1 β were decreased in D group (P＜0.05).Conclusion The mechanism by which dexmedetomidine reduces lung I/R injury may be related to down-regulating Semaphorin 7A expression,thus inhibiting inflammatory responses of rats.

Background: The mechanism of peripheral axon transport in neuropathic pain is still unclear. Chemokine ligand 13 (CXCL13) and its receptor (C-X-C chemokine receptor type 5, CXCR5) as well as GABA transporter 1 (GAT-1) play an important role in the development of pain. The aim of this study was to explore the axonal transport of CXCL13/CXCR5 and GAT-1 with the aid of the analgesic effect of botulinum toxin type A (BTX-A) in rats. Methods: Chronic constriction injury (CCI) rat models were established. BTX-A was administered to rats through subcutaneous injection in the hind paw. The pain behaviors in CCI rats were measured by paw withdrawal threshold and paw withdrawal latencies. The levels of CXCL13/CXCR5 and GAT-1 were measured by western blots. Results: The subcutaneous injection of BTX-A relieved the mechanical allodynia and heat hyperalgesia induced by CCI surgery and reversed the overexpression of CXCL13/CXCR5 and GAT-1 in the spinal cord, dorsal root ganglia (DRG), sciatic nerve, and plantar skin in CCI rats. After 10 mmol/L colchicine blocked the axon transport of sciatic nerve, the inhibitory effect of BTX-A disappeared, and the levels of CXCL13/CXCR5 and GAT-1 in the spinal cord and DRG were reduced in CCI rats. Conclusions BTX-A regulated the levels of CXCL13/CXCR5 and GAT-1 in the spine and DRG through axonal transport. Chemokines (such as CXCL13) may be transported from the injury site to the spine or DRG through axonal transport. Axon molecular transport may be a target to enhance pain management in neuropathic pain.

Descending nociceptive modulation from the supraspinal structures plays an important role in cancer-induced bone pain (CIBP).Rostral ventromedial medulla (RVM) is a critical component of descending nociceptive facilitation circuitry,but so far the mechanisms are poorly known.In this study,we investigated the role of RVM glial activation in the descending nociceptive facilitation circuitry in a CIBP rat model.CIBP rats showed significant activation of microglia and astrocytes,and also up-regulation of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) and pro-inflammatory mediators released by glial cells (IL-1β,IL-6,TNF-a and brain-derived neurotrophic factor) in the RVM.Stereotaxic microinjection of the glial inhibitors (minocycline and fluorocitrate) into CIBP rats' RVM could reverse the glial activation and significantly attenuate mechanical allodynia in a time-dependent manner.RVM microinjection of p38 MAPK inhibitor (SB203580) abolished the activation of microglia,reversed the associated up-regulation of pro-inflammatory mediators and significantly attenuated mechanical allodynia.Taken together,these results suggest that RVM glial activation is involved in the pathogenesis of CIBP.RVM microglial p38 MAPK signaling pathway is activated and leads to the release of downstream pro-inflammatory mediators,which contribute to the descending facilitation of CIBP.