P2X7R in periaqueductal gray matter participates in nociception modulation of chronic neuropathic pain / 临床麻醉学杂志

Objective To observe the distribution and possible mechanism of P2X7R in periaq-ueductal gray matter (PAG)in a rat model with chronic neuropathic pain in vivo.Methods The in-trathecal catheterization and sciatic nerve injury (SNI)were performed.All animals were randomly assigned into 3 groups with 26 rats in each,which was group Sham,control group (group C)and brilliant blue G (BBG)group (group BBG),respectively.Normal saline or BBG 10 μl were intrathe-cally injected after SNI and repeated for seven days.Paw-withdrawal mechanical thresholds (PWT) were measured on day 0,day 7,day 14,and day 21 after SNI.The rats were sacrificed and PAG tis-sues were collected on day 14 and day 21,separately.The distributions of P2X7R were observed by immunofluorescence.The protein contents of P2X7R and GFAP were assessed by Western blot assays.Results The P2X7R was expressed in PAG in rats.The PWTs of the control group showed a significant decrease during the 21-day period compared with the sham group.The P2X7R signals were predominantly expressed in astrocytes in PAG after SNI.Both P2X7R and GFAP expression remark-ably increased.Administration of BBG increased the PWTs,and inhibited the P2X7R and GFAP ex-pressions compared with those atthe same point of time of the control group.Conclusion These results indicated that P2X7R in PAG might participate in nociception modulation in the midbrain in chronic neuropathic pain.

Effects of nAChR antagonist α-conotoxin Eb1.6 on thermal pain threshold and spinal astrocytes activa-tion and IL-βexpression in rats using L5 nerve transaction model / 临床麻醉学杂志

Objective To observe the effects of nAChR antagonistα-conotoxin Eb1.6 on ther-mal pain threshold and spinal IL-1βexpression levels and astrocytes activation in rats using L5 spinal nerve transaction (SNT)model.Methods Fifty male Sprague-Dawley rats were randomly assigned into 5 groups with each group 10 rats:sham group,different doses of α-CTX Eb1.6 (0.1 5,1.5 and 1 5 nmol/kg)groups and the saline group after SNT.Saline solution or different doses of Eb1.6 were intraperitoneally injected seven days after the surgery when the model was stable and the treatment continued for seven days.Measured the TWLs of all groups of the rats 1,2,4,7,12 hours after the in-jection on 7 d and 13 d.The rats were sacrificed and L5 spinal cord tissues were collected immediately after the behavioral tests on 13 d.The expression of GFAP and IL-1βwere assessed by Western blot assay and enzyme linked immunosorbent assay (ELISA)separately.Results Groups E1,E2,E3 and C had shorter TWL before the injection on 7 d and 13 d than group N(P <0.05).The TWLs of the rats in groups E1,E2 and E3 of 1 h,2 h and 4 h after the injection on 7 d were significantly higher than that before the injection(P <0.05)with 2 h after the injection showed the most obvious change.The TWL of 1 h,2 h,4 h and 7 h after the injection of the rats in group E1,E2 and E3 and those of 12 h after the injection of the rats in group E2 and E3 on 13 d were significantly higher than that before the injection(P <0.05 )and also higher than TWL of the respective time points on 7 d(P < 0.05 ),also with 2 h after the injection showed the most obvious change.The TWLs of 2 h after the injection a-mong group E1,E2 and E3 showed significant differences both on 7 d and 13 d (P <0.05).Rats spi-nal IL-1βand GFAP expression levels of group E1,E2,E3 and C were significantly higher than those of group N(P <0.05).Rats spinal IL-1β and GFAP expression levels of groups E1,E2,E3 signifi-cantly decreased compared with group C(P <0.05).There were significant differences among the spi-nal IL-1βand GFAP expression levels of group E1,E2 and E3(P <0.05).Conclusion Eb1.6 dose-de-pendently reduced the thermal hyperalgesia induced by L5 spinal nerve transection.Repeated treat-ment of Eb1.6 could produce better analgesic effect,which might be partly attribute to the inhibition of spinal IL-βlevels and astrocytes activation.

Superior vena cava syndrome: A rare complication of percutaneous nephrolithotripsy laser lithotripsy.

PURPOSE: To describe a case of acute superior vena cava syndrome during percutaneous nephrolithotomy (PCNL), and to review the associated clinical features, management and complications. CLINICAL FEATURES: A 34-year-old man, diagnosed as right renal calculi and nodal tachycardia, was admitted to receive percutaneous nephroscope laser lithotripsy. Shortly after stone disintegration, he suffered acute hypoxic and hypotension, and showed cyanoderma of face and chest skin, ocular proptosis, jugular filling and ventricular fibrillation. Dopamine and adrenaline was intravenously injected. The patient was turned over to supine position and external cardiac massage and electric defibrillation were carried out immediately. The patient finally cardioverted. His vital signs subsequently became stable and cyanoderma faded. The patient was eventually discharged from the intensive care unit three days following the event. CONCLUSION: Severe complications such as cardiac arrest could happen during PCNL. Close monitoring the vital signs is essential for early finding and quick response to rescue.