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Objective:To evaluate the effect of pre-injection of young rat plasma on cognitive dysfunction after cerebral ischemia-reperfusion (I/R) in aged rats and the role of phosphatidylinositol 3-kinase/serine threonine protein kinase (PI3K/Akt) signaling pathway.Methods:Seventy-two SPF-grade healthy male Sprague-Dawley rats, aged 18 months, weighing 600-650 g, were divided into 4 groups ( n=18 each) by the random number table method: control group (group C), cerebral I/R group (group IR), pre-injection of young rat plasma group (group P) and PI3K inhibitor LY294002 group (group LY). In group P and group LY, young rat plasma 100 μl/time was injected via the tail vein. In group C and group IR, the equal volume of normal saline was injected via the the tail vein, 2 times a week for 4 weeks. Then the model of cerebral I/R injury was developed under sevoflurane anesthesia in IR, P and LY groups. LY294002 0.3 mg/kg was injected through the tail vein at 1 h before anesthesia in LY group. The neurological deficit score (Longa score) was performed at 24 h after reperfusion, and then 6 rats were randomly sacrificed, and brain tissues were obtained to determine the cerebral infarct volume. Spontaneous mobility and anxiety-like behavior were assessed by the open field test at day 29 of reperfusion, and cognitive function was assessed by the novel object recognition test at day 30 of reperfusion. At the end of the behavioral test, rats were sacrificed, hippocampal tissues were isolated for determination of the expression of phosphorylated PI3K (p-PI3K), phosphorylated Akt (p-Akt), postsynaptic dense protein-95 (PSD-95) and synaptic vesicle protein (SYN) (by Western blot), and the dendritic length and dendritic spine density of neurons in the hippocampal CA1 region. Results:There was no significant difference in motor speed, distance traveled, and time of staying at the center of the open field among the four groups ( P>0.05). Compared with group C, the Longa score and cerebral infarct volume were significantly increased, the percentage of novel object exploration and discrimination index were decreased, the expression of p-PI3K, p-Akt, PSD-95 and SYN in hippocampal tissues was down-regulated, and the dendritic length and dendritic spine density of hippocampal neurons were decreased in IR, P and LY groups ( P<0.05). Compared with group IR, Longa score and cerebral infarct volume were significantly decreased, the percentage of novel object exploration and discrimination index were increased, the expression of p-PI3K, p-Akt, PSD-95 and SYN in hippocampal tissues was up-regulated, and the dendritic length and dendritic spine density of hippocampal neurons were increased in group P ( P<0.05), and no significant change was found in the parameters mentioned above in group LY ( P>0.05). Compared with group P, Longa score and cerebral infarct volume were significantly increased, the percentage of novel object exploration and discrimination index were decreased, the expression of p-PI3K, p-Akt, PSD-95 and SYN in hippocampal tissues was down-regulated, and the dendritic length and dendritic spine density of hippocampal neurons were decreased in group LY ( P<0.05). Conclusions:Pre-injection of young rat plasma can attenuate cognitive dysfunction after cerebral I/R in aged rats, and the mechanism is related to activation of hippocampal PI3K/Akt signaling pathway and improvement in synaptic plasticity.
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Objective:To evaluate the role of 1, 4, 5-inositol triphosphate receptor (IP3R) in necroptosis of hippocampal neurons induced by sevoflurane anesthesia in aged rats.Methods:Sixty healthy male Sprague-Dawley rats, aged 18 months, weighing 500-600 g, were divided into 3 groups ( n=20 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S) and sevoflurane anesthesia + IP3R antagonist group (group S+ I). S and S+ I groups inhaled 2% sevoflurane for 5 h. In group S+ I, IP3 receptor antagonist 2-APB 3 mg/kg was intraperitoneally injected at 10 min before sevoflurane inhalation, and the equal volume of dimethyl sulfoxide was intraperitoneally injected in group C and group S. Morris water maze test was used to test the cognitive function on the day after the end of sevoflurane anesthesia.Then the animals were sacrificed and the brain tissues were obtained for microscopic examination of the pathological changes after HE staining and Nissl staining (with a light microscope) and for determination of the free calcium concentration ([Ca 2+ ] i) and rate of necroptosis of hippocampal neurons (by flow cytometry) and expression of IP3R, receptor-interacting protein kinase-1 (RIPK1), receptor-interacting protein kinase-3 (RIPK3) and phosphorylated mixed lineage kinase domain-like protein (p-MLKL) (by Western blot). Results:Compared with group C, the escape latency was significantly prolonged, the times of crossing the platform were reduced, the time of staying at the target quadrant was shortened, the [Ca 2+ ] i and necroptosis rate of hippocampal neurons were increased, and the expression of IP3R, RIPK1, RIPK3 and p-MLKL in hippocampal neurons was up-regulated in group S and group S+ I ( P<0.05). Compared with group S, the escape latency was significantly shortened, the times of crossing the platform were increased, the time of staying at the target quadrant was prolonged, the [Ca 2+ ] i and necroptosis rate of hippocampal neurons were decreased, and the expression of IP3R, RIPK1, RIPK3 and p-MLKL in hippocampal neurons was down-regulated in group S+ I ( P<0.05). Conclusions:The mechanism by which sevoflurane induces cognitive dysfunction may be related to the imbalance of calcium homeostasis caused by activation of IP3R and thus inducing programmed necrosis in aged rats.
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Objective:To evaluate the effect of esketamine on the efficacy of postoperative patient-controlled intravenous analgesia (PCIA) in the patients with moderate central sensitization undergoing high tibial osteotomy.Methods:Fifty-four patients of both sexes with moderate central sensitization, aged 45-64 yr, with body mass index of 18.0-32.5 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ, undergoing elective high tibial osteotomy, were divided into 2 groups ( n=27 each) using a random number table method: control group (group C) and esketamine group (group ES). Ultrasound-guided femoral nerve block was performed with 0.5% ropivacaine 30 ml on the operated side at 30 min before induction of anesthesia.In C and ES groups, midazolam 0.1 mg/kg, sufentanil 0.2 μg/kg, propofol 1.5 mg/kg, and cisatracurium besilate 0.15 mg/kg were intravenously injected in turn during induction of anesthesia, and in addition esketamine hydrochloride 0.5 mg/kg was injected in ES group, and the equal volume of 0.9% sodium chloride was injected in C group, and then a laryngeal mask airway was placed.Anesthesia was maintained with intravenous infusion of remifentanil 0.1-0.3 μg·kg -1·min -1 and propofol 4-6 mg·kg -1·h -1.Esketamine hydrochloride 0.2 mg/kg was intravenously injected once every 20 min until 30 min before the end of operation in ES group, the equal volume of 0.9% sodium chloride was injected according to the amount of esketamine hydrochloride injected for the same body weight at the same time point in C group, and additional cisatracurium besilate was administered intermittently according to the degree of muscle relaxation.Intraoperative BIS values were maintained at 40-60.Postoperative PCIA was performed, and the patient was admitted to the post-anesthesia care unit.When the efficacy of PCIA was not good, ketorolac tromethamine 30 mg was intravenously injected for rescue analgesia.The intraoperative consumption of remifentanil and propofol and emergence time in the anesthesia recovery room were recorded.The pressing times of PCA and the number of rescue analgesia in each group were recorded within 2 days after operation.The Chinese Richards-Campbell Sleep Questionnaire was used to assess the nighttime sleep quality on the night of surgery and 1 and 2 days after surgery.The Chinese Quality of Recovery was used to assess the early recovery quality at 1 and 2 days after surgery.The first postoperative off-bed time and first walked distance were recorded.The adverse reactions were recorded. Results:Compared with group C, the consumption of remifentanil and propofol was significantly reduced, the emergence time in the anesthesia recovery room was prolonged, the pressing times of PCA and the number of rescue analgesia were decreased within 2 days after operation, the quality of nighttime sleep was improved on the night of surgery and 1 and 2 days after operation, the quality of early recovery on 1 and 2 days after operation was increased, the first postoperative off-bed time was shortened, the first walked distance was prolonged, and the incidence of postoperative adverse effects was decreased in group ES ( P<0.05). Conclusions:Esketamine can enhance the efficacy of postoperative PCIA in the patients with moderate central sensitization undergoing high tibial osteotomy.
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Objective To study the role of beta endorphin (?-EP) in the pathogenesis of vitiligo. Methods Radioimmunoassay (RIA) was used to measure the levels of ?-EP in plasma from 40 patients and tissue fluid of lesional and non lesional skin from 33 patients with vitiligo. Results Plasma levels of ?-EP were significantly higher in patients with generalized(11.74?3.47 pmol/L), local(8.31?2.57) and segmental(8.61?2.61) vitiligo than those in normal controls(6.69?1.46). Tissue fluid levels of ?-EP were significantly higher in lesional skin (9.25?4.49 and 10.24?4.37) than those in non lesional skin (5.50?2.84 and 6.12?1.61) from patients with local and segmental vitiligo. Increased levels of ?-EP were observed in tissue fluid from both lesional and non lesional skin in patients with generalized vitiligo, however, no significant difference of ?-EP levels was found between the two kinds of skin tissue. Conclusion It is suggested that ?-EP might play a role in the pathogenesis of vitiligo.