Objective To investigate the effects of lactoferrin on activity of PKG in spinal dorsal horn in a rat model of neuropathic pain(NP).Methods Thirty-two male SD rats weighing 200-250 g were randomly divided into4 groups(n = 8 each): sham operation group(group S),NP group,lactoferrin group and KT5823(an inhibitor of PKG)group.Neuropathic pain was produced by placing loosely constrictive ligatures around the common sciatic nerve in group NP,lactoferrin and KT5823,while the sciatic nerve was only exposed but not ligated in groupS.In group S and NP,normal saline 10 μl + 50% dimethyl sulfoxide(DMSO)10 μl were injected intrathecally.Lactoferrin 100 μg + 50% DMSO 10 μl were given intrathecally in group lactoferrin.Lactoferrin 100 μg + KT5823 10 μl were given intrathecally in group KT5823.The paw withdrawal latency(PWL)to a thermal nociceptive stimulus was measured every 30 min within 180 min after administration.The rats were then sacrificed and the spinal cord was removed.The activity of PKG in the spinal dorsal horn was determined by immunofluorescence.Results Compared with group NP and KT5823,the PWL was significantly prolonged after administration in group lactoferrin and the PKG activity was significantly increased in group lactoferrin(P ＜ 0.05).There was no significant difference in the parameters mentioned above between group NP and group KT5823(P ＞ 0.05).Conclusion Lactoferrin reduces NP by inhibiting the activity of PKG in spinal dorsal horn in rats.

Objective:To evaluate the effects of ultrasound-guided quadratus lumborum block (QLB) on acute pain after total hip arthroplasty.Methods:A retrospective study was conducted of the 36 patients with hip osteoarthritis who had undergone selective one-side total hip arthroplasty under total intravenous anesthesia (TIVA) from January 2019 to January 2020. According to whether additional QLB was used or not they were divided into 2 equal groups ( n=18). The control group of 10 males and 8 females with an age of 60.5±9.4 years used mere TIVA while the QLB group of 7 males and 11 females with an age of 53.6±12.7 years used TIVA plus QLB. All patients accepted patient-controlled intravenous analgesia (PCIA) postoperatively. The 2 groups were compared in terms of visual analogue scale (VAS) at rest and during exercise and IL-6 level at 24 h postoperation, consumption of opioids and postoperative incidence of nausea and vomiting. Results:There were no significant differences between the 2 groups in their preoperative general data, indicating they were compatible ( P>0.05). The VAS scores at rest and during exercise in the QLB group (0.3 ± 0.5 and 0.8 ± 0.6) were significantly lower than in the control group (2.1 ± 0.7 and 2.7 ± 0.5), the IL-6 level in the former[40.9 (30.5, 56.3) pg/mL] was significantly lower than in the latter[165.0 (82.5, 276.5) pg/mL], the intraoperative total consumptions of sufentanil[6 (6, 7) μg] and remifentanil[1,370 (1,200, 1,485) μg] in the former were significantly lower than in the latter[35 (30, 40) μg and 1, 910 (1, 805, 2, 000) μg], and the postoperative incidenceof nausea and vomiting[27.8%(5/18)] in the former was significantly lower than in the latter[77.8%(14/18)] (all P<0.05). Conclusions:Ultrasound-guided quadratus lumborum block can effectively relieve acute pain in patients after total hip arthroplasty. It can suppress stress-related inflammatory factors, reduce consumption of opioids and incidence of postoperative nausea and vomiting.