Peripheral Neutrophils-Derived Matrix Metallopeptidase-9 Induces Postoperative Cognitive Dysfunction in Aged Mice.

Background: Aging is one of the most important risk factors of postoperative cognitive dysfunction (POCD); however, the mechanisms are still not completely understood. In this study, we explore the roles of matrix metalloproteinase-9 (MMP-9) in aged mice with POCD. Methods: Appendectomy was performed in 18-month-old C57BL/6 and MMP-9-/- mice under anesthesia to establish the POCD model. Learning and memory were assessed using the Morris water maze (MWM) or Barnes maze. Protein expression of MMP-9 was measured by Western blotting or enzyme-linked immunosorbent assay (ELISA). To explore the role of neutrophils-derived MMP-9 in POCD, we treated mice with anti-Gr-1 monoclonal antibody to deplete peripheral neutrophils. And the percentage of neutrophils and other leukocytes were detected by flow cytometry. We further used sodium fluorescein (NaFlu) to evaluate the blood-brain barrier (BBB) permeability. Results: The spatial learning and memory ability was injured, and expression of MMP-9 increased in both plasma and the hippocampus after anesthesia/surgery. However, cognitive dysfunction was alleviated in both MMP-9-/- and peripheral neutrophils-depleted mice. The permeability of BBB was increased after anesthesia/surgery while recused by anti-Gr-1 antibody administration. Conclusion: These findings suggest that peripheral neutrophils-derived MMP-9 could lead to POCD of aged mice through increasing the BBB permeability.

Electroacupuncture relieves neuropathic pain by inhibiting degradation of the ecto-nucleotidase PAP in the dorsal root ganglions of CCI mice.

BACKGROUND: Although electroacupuncture is widely used in chronic pain management, it is quite controversial due to its unclear mechanism. We hypothesised that EA alleviates pain by inhibiting degradation of the ecto-nucleotidase prostatic acid phosphatase (PAP) and facilitating ATP dephosphorylation in dorsal root ganglions (DRGs). METHODS: We applied EA in male C57 mice subjected to chronic constriction injury (CCI) and assessed extracellular ATP and 5'-nucleotidease expression in DRGs. Specifically, we used a luminescence assay, quantitative reverse transcriptase-polymerase chain reaction, Western blotting, immunohistochemistry and nociceptive-related behavioural changes to gather data, and we tested for effects after PAP expression was inhibited with an adeno-associated virus (AAV). Moreover, membrane PAP degradation was investigated in cultured DRG neurons and the inhibitory effects of EA on this degradation were assessed using immunoprecipitation. RESULTS: EA treatment alleviated CCI surgery-induced mechanical pain hypersensitivity. Furthermore, extracellular ATP decreased significantly in both the DRGs and dorsal horn of EA-treated mice. PAP protein but not mRNA increased in L4-L5 DRGs, and inhibition of PAP expression via AAV microinjection reversed the analgesic effect of EA. Membrane PAP degradation occurred through a clathrin-mediated endocytosis pathway in cultured DRG neurons; EA treatment inhibited the phosphorylation of adaptor protein complex 2, which subsequently reduced the endocytosis of membrane PAP. CONCLUSIONS: EA treatment alleviated peripheral nerve injury-induced mechanical pain hypersensitivity in mice by inhibiting membrane PAP degradation via reduced endocytosis and subsequently promote ATP dephosphorylation in DRGs. SIGNIFICANCE: In a mouse model of chronic pain, electroacupuncture treatment increased levels of prostatic acid phosphatase (PAP: an ecto-nucleotidase known to relieve pain hypersensitivity) by inhibiting PAP degradation in dorsal root ganglions. This promoted extracellular ATP dephosphorylation, inhibited glia activation and eventually alleviated peripheral nerve injury-induced mechanical pain hypersensitivity in mice. Our findings represent an important step forward in clarifying the mechanisms of pain relief afforded by acupuncture treatment.

Pre-operative administration of butorphanol mitigates emergence agitation in patients undergoing functional endoscopic sinus surgery: A randomized controlled clinical trial.

Background: This study explored the effectiveness of pre-operative intravenous injection of butorphanol in the alleviation of emergence agitation (EA) in patients undergoing functional endoscopic sinus surgery (FESS). Methods: Patients (n = 708) were randomized into two groups. The butorphanol group (Group B, n = 358) received butorphanol infusion (20 ug/kg) before anesthesia induction, while the control group (Group C, n = 350) received an equal volume of normal saline infusion. General anesthesia was induced with sufentanil, propofol, and rocuronium, and was maintained with sevoflurane and remifentanil. Vasoactive drugs maintained the hemodynamic indices within 20% of the baseline. Results: The incidence of EA was significantly lower in Group B than that in Group C (Group B vs. C: 24.3% vs. 31.4%, respectively; P = 0.034). The times to spontaneous breathing (26.5 min vs. 23.7 min, P = 0.011), verbal response (36.0 min vs. 33.4 min, P = 0.012), and extubation (31.0 min vs. 28.7 min, P = 0.025) were longer in Group B, and the grade of cough (0.33 vs. 0.43, P = 0.024) at extubation in Group B was lower than that in Group C (P = 0.024). The mean arterial pressure at the end of the operation (P = 0.004) and at 5 min after extubation (P = 0.008) was higher and hypotension was less prominent (0.6% vs. 2.6%, P = 0.030) in Group B. Conclusion: Pre-operative intravenous injection of butorphanol decreased the incidence of EA after FESS and provided smooth and hemodynamically stable emergence without extending the stay in post-anesthesia care unit. Clinical trial registration: https://www.clinicaltrials.gov/, identifier NCT03398759.

Publication Trends and Hot Spots in Femoroacetabular Impingement Research: A 20-Year Bibliometric Analysis.

BACKGROUND: Femoroacetabular impingement (FAI) has attracted increasing attention over the past few decades. We aim to evaluate FAI research and predict research hot spots quantitatively and qualitatively. METHODS: The publications in FAI research between 2000 and 2019 were assimilated from the Web of Science Core Collection of Clarivate Analytics. The retrieved data were evaluated by the bibliometric method. Software CiteSpace 5.7.R1, VOSviewer 1.6.15, and the Online Analysis Platform of Literature Metrology (http://bibliometric.com/) were used to analyze and identify the hot spots and trends in this field. RESULTS: A total of 2471 originals articles that fulfilled the study requirements were obtained. The number of manuscripts on FAI has experienced rapid growth, especially after 2009. The United States of America was the leading country for publication and to the collaboration network. FAI, osteoarthritis, hip arthroscopy, labral reconstruction, pathomorphology, outcome, rehabilitation, and joint cartilage are some of the high-frequency keywords in co-occurrence cluster analysis and cocited reference cluster analysis. Burst detection analysis of top keywords revealed that outcomes, instability, labral reconstruction, adolescent, and risk factor were newly emerged research hot spots. CONCLUSION: The understanding of FAI has been improved significantly during the past two decades. Present studies focused on identifying the optimal method to treat labral pathology, outcome assessment of either surgeries or conservative managements, and predicting midterm and long-term outcomes. Together these studies exert critical implications for decision-making and management for FAI.

National survey on sedation for gastrointestinal endoscopy in 2758 Chinese hospitals.

BACKGROUND: Although sedation during gastrointestinal endoscopy is widely used in China, the characteristics of sedation use, including regional distribution, personnel composition, equipment used, and drug selection, remain unclear. The present study aimed to provide insights into the current practice and regional distribution of sedation for gastrointestinal endoscopy in China. METHODS: A questionnaire consisting of 19 items was distributed to directors of anaesthesiology departments and anaesthesiologists in charge of endoscopic sedation units in mainland China through WeChat. RESULTS: The results from 2758 participating hospitals (36.7% of the total) showed that 9 808 182 gastroscopies (69.3%) and 4 353 950 colonoscopies (30.7%), with a gastroscopy-to-colonoscopy ratio of 2.3, were conducted from January to December 2016. Sedation was used with 4 696 648 gastroscopies (47.9%) and 2 148 316 colonoscopies (49.3%), for a ratio of 2.2. The most commonly used sedative was propofol (61.0% for gastroscopies and 60.4% for colonoscopies). Haemoglobin oxygen saturation (SpO2) was monitored in most patients (96.1%). Supplemental oxygen was routinely administered, but the availability of other equipment was variable (anaesthesia machine in 64.9%, physiological monitor in 84.4%, suction device in 72.3%, airway equipment in 75.5%, defibrillator in 32.7%, emergency kit in 57.0%, and difficult airway kit in 20.8% of centres responding). CONCLUSIONS: The sedation rate for gastrointestinal endoscopy is much lower in China than in the USA and in Europe. The most commonly used combination of sedatives was propofol plus an opioid (either fentanyl or sufentanil). Emergency support devices, such as difficult airway devices and defibrillators, were not usually available.

Multiple Anesthesia/Surgery Cannot Impair Reference Memory in Adult Mice.

Postoperative cognitive dysfunction increases mortality and morbidity in perioperative patients. Numerous studies have demonstrated that multiple surgery/anesthesia during the neurodevelopmental period affects cognitive function, whereas a single anesthesia/surgery rarely causes cognitive dysfunction in adults. However, whether adults who undergo multiple anesthesia/surgery over a short period will experience cognitive dysfunction remains unclear. In this study, central nervous system inflammation and changes in cholinergic markers were investigated in adult mice subjected to multiple laparotomy procedures over a short period of time. The results showed that despite the increased expression of IL-6 and TNF-α in the hippocampus after multiple operations and the activation of microglia, multiple anesthesia/surgery did not cause a decline in cognitive function in adult mice. There were no changes in the cholinergic markers after multiple anesthesia/surgery.