Association Between the Blood Glucose Value at PACU Discharge and Postoperative Hypoglycemia in Nondiabetic Patients With Hyperglycemia After Hysteroscopic Surgery: A Retrospective Cohort Study.

PURPOSE: The target glycemic control for nondiabetic patients in the postanesthesia care unit (PACU) after hysteroscopic surgery remains unclear. Our goal is to determine the optimal level of glycemic control by finding the relationship between blood glucose level (BGL) leaving the PACU and postoperative hypoglycemia in nondiabetic patients. DESIGN: This retrospective cohort study was conducted at a comprehensive tertiary hospital in Chongqing, China between June 2018 and December 2020. METHODS: The target independent and dependent variables were BGL leaving the PACU and postoperative hypoglycemia, respectively. The primary outcome was the incidence of hypoglycemia. Logistic regression was used to explore the association between discharge BGL and hypoglycemia. The optimal glycemic control range was determined by using the receiver operating characteristic (ROC) curve. FINDINGS: Prior to insulin use, BGL in the insulin-using subgroup might be as high as 20 mmol/L. Hypoglycemia was related to the BGL while leaving the PACU (odds ratio (OR) 0.37 [95% confidence interval (CI) 0.22 to 0.65]). The best cut-off value (12.95 mmol/L) was determined by fitting the ROC curve. CONCLUSIONS: If severe hyperglycemia develops during hysteroscopic surgery in individuals with 5% glucose as the mediator of uterine distention, the recommendation is to maintain blood glucose above 12.95 mmol/L when treated with insulin.

Association of the placenta accreta spectrum score and estimated blood loss in placenta accreta spectrum patients with placenta previa: a retrospective cohort study.

PURPOSE: The placenta accreta spectrum (PAS) score calculated by the scoring system may predict patients with PAS. We aim to find the relationship between estimated blood loss and the PAS score. Further, find the inflection point, identify PAS patients with placenta previa who were at risk for major bleeding. METHODS: The PAS patients with placenta previa, as diagnosed by color Doppler ultrasound, were divided into two groups according to their PAS scores using a new scoring system. Blood loss, transfusion requirements, the rate of Intra-Abdominal Balloon Occlusion (IABO), and other indicators were analyzed between groups. RESULTS: The estimated blood loss, intraoperative transfusion, postoperative transfusion, operation time, and hospitalization time significantly increased in the group with a PAS score ≥ 9 (P < 0.05). The inflection point analysis revealed that a significant increase in estimated blood loss occurred when the PAS score was beyond 10 (crude) or 6 (adjusted for age, body mass index, and IABO). CONCLUSION: There was a non-linear relationship between estimated intraoperative blood loss and PAS score. When the PAS score was greater than 9, hemorrhage, the risk of major bleeding, the need for transfusions, and the placement of an abdominal aortic balloon all increase significantly.

Safety and Comfort of Wearing Medical Masks in Adult Surgical Patients After General Anesthesia During the COVID-19 Epidemic: A Retrospective, Observational Cohort Study.

OBJECTIVE: This study assessed oxygen saturation variation and comfort in adult surgical patients wearing masks in PACU during the COVID-19 epidemic. DESIGN: Retrospective observation was applied in this study. METHODS: One hundred thirty-seven patients wearing no medical masks (Group A, aged from 20 to 87) and 136 patients wearing medical masks (Group B, aged from 18 to 91) were selected in this retrospective study after extubation in PACU. After extubation their pulse oxygen saturation, noninvasive mean blood pressure and heart rate were recorded at two different time points (treated with 40% O2 oxygen therapy for 10 minutes and breathing room air for 10 minutes). The comfort, arterial blood gas data, complications and duration of patients were also reviewed in PACU. FINDINGS: There were no significant differences in the pulse oxygen saturation between the two groups after inhaling 40% O2 or air. Compared with Group A, patients in Group B have lower comfort (6 [4-7] vs 7 [6-8]; P < .001), with shortened duration after extubation in PACU (50 [45-55] vs 56 [48-60]; P < .001). No significant differences were found in heart rate, noninvasive mean blood pressure, arterial blood gas data and complications. And no hypoxemia and respiratory adverse events happened in two groups. CONCLUSIONS: Wearing medical masks does not reduce oxygen saturation in adult surgical patients during recovery from general anesthesia. The discomfort caused by masks is the concern in PACU.

Effectiveness of Acupuncture Therapy on Postoperative Nausea and Vomiting After Gynecologic Surgery: A Meta-Analysis and Systematic Review.

PURPOSE: The aim of this study was to evaluate the effectiveness and safety of acupuncture therapy (AT) on postoperative nausea and vomiting (PONV) after gynecologic surgery (GS). DESIGN: A meta-analysis using a systematic search strategy was performed. METHODS: A comprehensive literature search of all published randomized controlled trials or prospective cohort studies assessing the effectiveness of AT on PONV in patients undergoing GS was conducted in three databases: PubMed, EMBASE, and Cochrane Library. The incidence of PONV, the use of rescue antiemetics, and side effects of AT were analyzed using the Review Manager 5.3 software. FINDINGS: Nine randomized controlled trials and one prospective cohort study identified in the literature search from database inception (1966) to December 31, 2019, including 1,075 participants were included in the present study. AT significantly reduced the risk of developing postoperative nausea and postoperative vomiting by 48% (relative risk = 0.52; 95% confidence interval, 0.44 to 0.61; P < .00001) and 42% (relative risk = 0.58; 95% confidence interval, 0.49 to 0.68; P < .00001), respectively. No significant differences in the incidence of side effects such as bleeding and needle pain were observed between groups (P = .54). AT was also associated with a lower rate of rescue antiemetic usage (P < .00001) and a higher degree of satisfaction with postoperative recovery (P < .0001). Moreover, the optimal therapeutic effect of AT on preventing PONV was achieved when the treatment time was controlled within 30 minutes and transcutaneous acupoint electrical stimulation was applied. CONCLUSION: AT is an effective and safe physical therapy for the prophylaxis of PONV in patients undergoing GS.

MicroRNA-193a Downregulates HMGB1 to Alleviate Diabetic Neuropathic Pain in a Mouse Model.

BACKGROUND: Diabetic neuropathy is a serious complication for diabetic patients involving the nervous system. This disease is a quiet but painful condition caused by chronically high blood glucose levels. It is reported that high mobility group box 1 protein (HMGB1) participates in the development of neuropathic pain. This study aimed to explore the role of microRNA (miR)-193a in diabetic neuropathic pain through the regulation of HMGB1. METHODS: A diabetic mouse model was established through the injection of streptozocin (STZ). Neuropathic pain development was shown by paw withdrawal thresholds and paw withdrawal latency. Expression levels of relative genes or miR were analyzed by qRT-PCR, while Western blot was employed to assess the protein levels. The interaction between miR-193a and HMGB1 mRNA 3'-UTR region was shown by luciferase assay. The levels of inflammation cytokines were measured by ELISA kits. RESULTS: miR-193a expression was decreased and HMGB1 expression was upregulated in the lumbar spinal dorsal horn of STZ-induced diabetic mice. miR-193a inhibited HMGB1 expression in the lumbar spinal dorsal horn. Overexpression of miR-193a alleviated neuropathic pain in STZ-induced diabetic mice. Peripheral neuroinflammation in diabetic mice was suppressed by miR-193a overexpression. CONCLUSION: This research illustrates that miR-193a alleviates diabetic neuropathic pain in a mouse model through the inhibition of HMGB1 expression.

Acute stress enhances learning and memory by activating acid-sensing ion channels in rats.

Acute stress has been shown to enhance learning and memory ability, predominantly through the action of corticosteroid stress hormones. However, the valuable targets for promoting learning and memory induced by acute stress and the underlying molecular mechanisms remain unclear. Acid-sensing ion channels (ASICs) play an important role in central neuronal systems and involves in depression, synaptic plasticity and learning and memory. In the current study, we used a combination of electrophysiological and behavioral approaches in an effort to explore the effects of acute stress on ASICs. We found that corticosterone (CORT) induced by acute stress caused a potentiation of ASICs current via glucocorticoid receptors (GRs) not mineralocorticoid receptors (MRs). Meanwhile, CORT did not produce an increase of ASICs current by pretreated with GF109203X, an antagonist of protein kinase C (PKC), whereas CORT did result in a markedly enhancement of ASICs current by bryostatin 1, an agonist of PKC, suggesting that potentiation of ASICs function may be depended on PKC activating. More importantly, an antagonist of ASICs, amiloride (10 µM) reduced the performance of learning and memory induced by acute stress, which is further suggesting that ASICs as the key components involves in cognitive processes induced by acute stress. These results indicate that acute stress causes the enhancement of ASICs function by activating PKC signaling pathway, which leads to potentiated learning and memory.

Acid-sensing ion channels contribute to the effect of extracellular acidosis on proliferation and migration of A549 cells.

Acid-sensing ion channels, a proton-gated cation channel, can be activated by low extracellular pH and involved in pathogenesis of some tumors such as glioma and breast cancer. However, the role of acid-sensing ion channels in the growth of lung cancer cell is unclear. In this study, we investigated the expression of acid-sensing ion channels in human lung cancer cell line A549 and their possible role in proliferation and migration of A549 cells. The results show that acid-sensing ion channel 1, acid-sensing ion channel 2, and acid-sensing ion channel 3 are expressed in A549 cells at the messenger RNA and protein levels, and acid-sensing ion channel-like currents were elicited by extracellular acid stimuli. Moreover, we found that acidic extracellular medium or overexpressing acid-sensing ion channel 1a promotes proliferation and migration of A549 cells. In addition psalmotoxin 1, a specific acid-sensing ion channel 1a inhibitor, or acid-sensing ion channel 1a knockdown can abolish the effect of acid stimuli on A549 cells. In addition, acid-sensing ion channels mediate increase of [Ca2+]i induced by low extracellular pH in A549 cells. All these results indicate that acid-sensing ion channel-calcium signal mediate lung cancer cell proliferation and migration induced by extracellular acidosis, and acid-sensing ion channels may serve as a prognostic marker and a therapeutic target for lung cancer.

Postoperative cognitive dysfunction in elderly patients with colorectal cancer: A randomized controlled study comparing goal-directed and conventional fluid therapy.

To investigate the impact of goal-directed fluid therapy (GDFT) on postoperative cognitive dysfunction (POCD) in elderly patients with colorectal cancer, we conducted a randomized controlled trial. Eighty elderly patients who underwent elective laparoscopic radical resection of colorectal cancer were randomly assigned to either the GDFT group or the conventional fluid therapy group. The primary outcome was the incidence of POCD during the initial 7 postoperative days, while secondary outcomes included inflammatory marker levels such as interleukin-6 (IL-6) and S100ß protein, hemodynamics, level of lactic acid, postoperative functional recovery, and complications. Among 88 randomized patients, 80 were evaluable for the primary outcome. The incidence of POCD was significantly lower in the GDFT group (15.0%) compared to the conventional fluid therapy group (30.0%), with the highest occurrence observed on day 3 postoperatively in both groups (P < 0.05). IL-6 and S100ß concentrations were consistently lower in the GDFT group than in the conventional fluid therapy group at the corresponding time points (P < 0.05). The GDFT group exhibited more stable perioperative hemodynamics and lower lactate levels (P < 0.05). Moreover, patients in the GDFT group exhibited better postoperative functional recovery indicators and a lower incidence of postoperative complications (P < 0.05). In summary, GDFT appears to reduce the incidence of early POCD, accelerate postoperative recovery, and enhance overall prognosis.

Timing of intra-abdominal aortic balloon occlusion for prevention of hemorrhage in patients with placenta previa and placenta accreta spectrum.

OBJECTIVE: Placenta accreta spectrum (PAS) has been linked to severe negative maternal-fetal pregnancy outcomes, including a high risk of maternal death. The goal of this study was to determine whether an abdominal aortic balloon block performed before fetal birth lowered intraoperative bleeding and the risk of severe bleeding, as opposed to a block performed after fetal birth. METHODS: In this retrospective cohort study, patients who underwent pre-delivery or post-delivery inflation were compared for intraoperative hemorrhage, transfusion rate, hysterectomy rate, intensive care unit (ICU) hospitalization, and newborn indices. To ensure the robustness of our findings, we applied multivariate logistic regression, propensity score analysis, and an inverse probability-weighting model. RESULTS: This study included 168 patients who underwent balloon occlusion (62 pre-delivery, 106 post-delivery). The overall probability of major bleeding was 56.5% (95/168), and the pre-delivery and post-delivery probabilities for major bleeding were 64.5% (40/62) and 51.9% (55/106) (P = 0.112), respectively. In the multivariable-adjusted model, post-delivery inflation was associated with a 33% numerically higher probability of massive bleeding (odds ratio 1.33, 95% confidence interval 0.54-3.25, P = 0.535). However, the difference was not statistically significant. CONCLUSION: According to our findings, pre-delivery inflation did not significantly reduce the risk or amount of severe bleeding.

Acid-sensing ion channels contribute to the increase in vesicular release from SH-SY5Y cells stimulated by extracellular protons.

Acid-sensing ion channels (ASICs) have been reported to play a role in the neuronal dopamine pathway, but the exact role in neurotransmitter release remains elusive. Human neuroblastoma SH-SY5Y is a dopaminergic neuronal cell line, which can release monoamine neurotransmitters. In this study, the expression of ASICs was identified in SH-SY5Y cells to further explore the role of ASICs in vesicular release stimulated by acid. We gathered evidence that ASICs could be detected in SH-SY5Y cells. In whole cell patch-clamp recording, a rapid decrease in extracellular pH evoked inward currents, which were reversibly inhibited by 100 µM amiloride. The currents were pH dependent, with a pH of half-maximal activation (pH(0.5)) of 6.01 ± 0.04. Furthermore, in calcium imaging and FM 1-43 dye labeling, it was shown that extracellular protons increased intracellular calcium levels and vesicular release in SH-SY5Y cells, which was attenuated by PcTx1 and amiloride. Interestingly, N-type calcium channel blockers inhibited the vesicular release induced by acidification. In conclusion, ASICs are functionally expressed in SH-SY5Y cells and involved in vesicular release stimulated by acidification. N-type calcium channels may be involved in the increase in vesicular release induced by acid. Our results provide a preliminary study on ASICs in SH-SY5Y cells and neurotransmitter release, which helps to further investigate the relationship between ASICs and dopaminergic neurons.

Association between cervical length and massive intraoperative bleeding in patients with suspected placenta accreta spectrum combined with placenta previa: A retrospective cohort study.

Purpose: Abnormal placentation is a spectrum disorder that includes creta, increta, and percreta; the term placenta accreta spectrum (PAS) disorders is used as a broad term to describe all of these conditions. PAS can lead to life-threatening hemorrhage. The predictive value of cervical length (CL) in patients with PAS remains controversial. Thus, this study investigated the relationship between CL and the probability of major bleeding in patients with PAS and placenta previa. Methods: This retrospective cohort study was conducted at a comprehensive tertiary hospital in Chongqing, China, between January 2018 and December 2020. The target independent and dependent variables were CL and intraoperative massive bleeding, respectively. The covariates included demographic, clinical, and ultrasound characteristics. Logistic regression was used to explore the association between CL and massive bleeding. Results: In total, 317 participants were enrolled, in whom the prevalence of massive bleeding was 41.9% (133/317). The threshold of CL associated with massive bleeding (≥1,000 ml) was 33 mm based on a receiver operating characteristic curve. In the fully adjusted model for each additional unit of CL, the risk of massive bleeding decreased by 7% [95% confidence interval (CI), 0.88-0.98]. The risk of major bleeding was reduced by 44% in patients with a CL greater than 33 mm (95% CI, 0.33-0.97) compared with patients with a CL less than 33 mm. Conclusions: CL was negatively associated with massive intraoperative bleeding in patients with PAS combined with placenta previa. When the CL was greater than 33 mm, the risk of bleeding decreased by 44%. Thus, CL can be used as a standalone parameter to identify the risk of massive intraoperative bleeding in patients with suspected PAS.

Acupoint Stimulation for Enhanced Recovery After Colon Surgery: A Prospective Multicenter Randomized Controlled Trial.

Purpose: The aim of this study was to evaluate the efficacy of transcutaneous electrical acupoint stimulation (TEAS) in improving bowel function and thus shortening hospital stay after laparoscopic colon surgery within the ERAS pathway. Patients and Methods: From November 2016 to March 2018, 100 patients who underwent elective colon surgery were enrolled and 94 finished study (n = 47 for each) in three university hospitals. Patients in the TEAS group received TEAS 30 min before surgery and once a day for 3 days after surgery, while those in the Control Group received no stimulation. Primary outcome was the time to discharge. Results: Compared with standardized postoperative care, TEAS resulted in a shorter time to first flatus (P=0.03) and time to first defecation (P=0.03), as well as a reduction in the length of hospital stay (P=0.02). Median patient-controlled analgesia (PCA) deliveries and PCA attempts at 24h, 48h and 72h after surgery were less in the TEAS group (P<0.01). No evidence of significant advantages in postoperative pain intensity, nausea, vomiting, sleeping quality and expenses was found in the TEAS group. Conclusion: Perioperative TEAS further shortens the time to meet discharge criteria after laparoscopic colon surgery in patients under ERAS strategy.

Transcutaneous Electrical Acupoint Stimulation Combined with Dexamethasone and Tropisetron Prevents Postoperative Nausea and Vomiting in Female Patients Undergoing Laparoscopic Sleeve Gastrectomy: a Prospective, Randomized Controlled Trial.

BACKGROUND: Despite the administration of prophylactic antiemetics, some patients who undergo laparoscopic sleeve gastrectomy (LSG) remain at high risk for postoperative nausea and vomiting (PONV). Although many trials have been conducted, the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) on the prevention of PONV remains unknown. METHODS: Sixty-two female patients undergoing elective LSG were randomly assigned to the TEAS combined with dexamethasone and tropisetron (TEAS group, n = 31) or dexamethasone and tropisetron (control group, n = 31) groups. The incidence and severity of PONV, as well as the need for rescue antiemetics, were collected within 48 h after surgery. RESULTS: The patients in both groups had similar clinical characteristics and underwent the same surgical procedure. In the TEAS group, 13 patients (41.9%) had PONV within 48 h after LSG compared to 24 patients (77.4%) in the control group (P = 0.004, relative risk: 0.39 [0.19, 0.80]). The severity of PONV differed significantly between groups, with five patients (16.1%) in the TEAS group and 15 patients (48%) in the control group experiencing clinically important PONV (P = 0.007, relative risk: 0.62 [0.42, 0.90]). Moreover, fewer patients required antiemetic rescue medication in the TEAS group compared with the control group (29.0% vs. 58.1%, P = 0.021). CONCLUSION: Multimodal antiemetic prophylaxis consisting of TEAS and antiemetics was effective in reducing PONV incidence and intensity in high-risk patients undergoing LSG.

Perioperative Exercise Intention and Influencing Factors: A Multi-Centered Cross-Sectional Study.

Objectives: This study aimed to evaluate the level and factors affecting the perioperative exercise intention in China. Design: This study was a cross-sectional survey in Southwest China. Methods: Four hundred and ninety nine participants were randomly sampled in eight medical centers from November 23, 2020 to November 27, 2020. The survey included sociodemographic information and a 24-item modified questionnaire, which aimed to evaluate the attitude toward daily exercise, perception of perioperative exercise, social support and the perioperative exercise intention. A multivariable linear regression model was used to evaluate the effect of different items on the patients' intention for perioperative exercise. Results: A total of 523 responses (95.09%) were collected and 499 (95.41%) were analyzed. The level of exercise intention of the patients during the perioperative period was: 14.83% planned to exercise every day in the hospital, 21.04% planned to exercise every other day, and 35.87% planned to exercise every week. Intensity of daily exercise (P = 0.016), positive attitude of daily exercise (P < 0.001), positive attitude of perioperative exercise (P < 0.001) and social support (P < 0.001) were positively associated with the intention for perioperative exercise. Female (P = 0.012), non-tertiary center (P = 0.011), and preoperative anxiety (P = 0.023) was negatively associated with it. Conclusions: The intention for perioperative exercise was low in Southwest China. The authors aimed to relieve preoperative anxiety, promote the education of perioperative exercise, design perioperative exercise programs, and provide more social support from medical staff and family for inpatients undergoing elective surgery.

Disruption of PICK1 attenuates the function of ASICs and PKC regulation of ASICs.

Acid-sensing ion channels (ASICs) extensively exist in both central and peripheral neuronal systems and contribute to many physiological and pathological processes. The protein that interacts with C kinase 1 (PICK1) was cloned as one of the proteins interacting with protein kinase C (PKC) and colocalized with ASIC1 and ASIC2. Here, we used PICK1 knockout (PICK1-KO) C57/BL6 mice together with the whole cell patch clamp, calcium imaging, RT-PCR, Western blot, and immunocytochemistry techniques to explore the possible change in ASICs and the regulatory effects of PKC on ASICs. The results showed that PICK1 played a key role in regulation of ASIC functions. In PICK1-KO mouse cortical neurons, both the amplitude of ASIC currents and elevation of [Ca(2+)](i) mediated by acid were decreased, which were attributable to the decreased expression of ASIC1a and ASIC2a proteins in the plasma membrane. PKC, a partner protein of PICK1, regulated ASIC functions via PICK1. The agonist and antagonist of PKC only altered ASIC currents and acid-induced increase in [Ca(2+)](i) in wild-type, but not in KO mice. In conclusion, our data provided the direct evidence from PICK1-KO mice that a novel target protein, PICK1, would regulate ASIC function and membrane expression in the brain. In addition, PICK1 played the bridge role between PKC and ASICs.

Existence and distinction of acid-evoked currents in rat astrocytes.

Astrocytes are vital structures that support and/or protect neighboring neurons from pathology. Although it is generally accepted that glutamate receptors mediate most astrocyte effects, acid-evoked currents have recently attracted attention for their role in this regard. Here, we identified the existence and characteristics of acid-sensing ion channels (ASICs) and the transient receptor potential vanilloid type 1 (TRPV1) in astrocytes. There were two types of currents recorded under the application of acidic solution (pH 6.0) in cultured rat astrocytes. Transient currents were exhibited by 10% of the astrocytes, and sustained currents were exhibited by the other 90%, consistent with the features of ASIC and TRPV1 currents, respectively. Western blotting and immunofluorescence confirmed the expression of ASIC1, ASIC2a, ASIC3, and TRPV1 in cultured and in situ astrocytes. Unlike the ASICs expressed in neurons, which were mainly distributed in the cell membrane/cytoplasm, most of the ASICs in astrocytes were expressed in the nucleus. TRPV1 was more permeable to Na(+) in cultured astrocytes, which differed from the typical neuronal TRPV1 that was mainly permeable to Ca(2+). This study demonstrates that there are two kinds of acid-evoked currents in rat astrocytes, which may provide a new understanding about the functions of ligand-gated ion channels in astrocytes.

[A pilot study of trans-esophageal aortic pulse oxygen saturation signals].

It is the intent of this study to simulate the performance of trans-esophageal aortic blood oxygen saturation (SeO2) monitoring by using trans-esophageal echocardiography (TEE) probe to provide an evidence for proper positioning of placing SeO2 sensor. 25 selected cardiac surgical patients were involved. After anesthesia was induced and trachea was intubated, the multiplane TEE probe was inserted into the esophagus, and the depths from the fore-tooth to the location for detecting aorta were recorded when the distances between TEE probe and aorta anterior wall were shorter than 0.5 cm, 1 cm, and longer than 1 cm, respectively. The o'clock directions of TEE probe were also recorded. The multiplane TEE probe, with its one-use pediatric SpO2 sensor attached, was inserted, and its anterior structure was examined when trans-esophagus oximetry detected high quality SpO2 signals. The results showed the beginning position of detecting aortic SpO2 signal in esophagus was mid esophagus (24.8 +/- 4.4 cm from the fore-teeth), the moving range was 5-10 cm downward, the deepest depth of detecting descending aorta was 41.4 +/- 4.7 cm from the fore-tooth, and the direction was left-posterior. And photoplethymography (PPG) wave's form was changed when SpO2 probe's anterior structure was different.

Experimental Investigation on Rotating Electrochemical Etching of a Micro Spiral Cylindrical Electrode.

To realize the electrochemical etching of a micro spiral cylindrical electrode, a new method of rotating electrochemical etching is proposed, and its process is further studied. First, according to the electrochemical etching principle, the machining mechanism of rotating electrochemical etching of a micro spiral cylindrical electrode is introduced. Second, based on the spiral vortex theory in the Taylor-Couette system, the effect of the high-speed rotating cylindrical microelectrode on its external flow field is analyzed. Third, the effects of rotation direction, rotation speed, machining voltage, and machining time on the thread structure are analyzed by experiments. Finally, a spiral cylindrical microelectrode with good surface thread shape is fabricated within two minutes by using the optimized machining parameters. It is proved that the rotating electrochemical etching method is an easy way to fabricate a micro spiral cylindrical electrode with high efficiency and low cost.

Increased Homer1-mGluR5 mediates chronic stress-induced depressive-like behaviors and glutamatergic dysregulation via activation of PERK-eIF2α.

Glutamatergic dysregulation has served as one common pathophysiology of major depressive disorder (MDD) and a promising target for treatment intervention. Previous studies implicate neurotransmission via metabotropic glutamate receptors (mGluRs) and Homer1 in stress-induced anhedonia, but the mechanisms have not been well elucidated. In the present study, we used two different animal models of depression, chronic social defeat stress (CSDS) and chronic restraint stress (CRS), to investigate the expression of Homer1 isoforms and functional interaction with mGluRs. We found that chronic stress selectively upregulated the expression of Homer1b/c in the hippocampus, whereas the level of Homer1a was unchanged. Additionally, there was a significant negative correlation between the levels of Homer1-mGluR5 signaling and depressive-like behaviors. Both application of paired-pulse low-frequency stimulation (PP-LFS) and the selective group 1 mGluRs agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) significantly enhanced mGluR-dependent long-term depression (LTD) at CA3-CA1 pyramidal cell synapses in slices from susceptible mice, whereas there was no change in NMDAR-dependent LTD induced by LFS. Furthermore, these effects were associated with the internalization of surface AMPARs in hippocampal pyramidal neurons, including reduced the expression of AMPARs and amplitude of AMPARs-mediated mEPSC. Finally, we found that chronic stress activated the KR-like ER kinase-eukaryotic initiation factor 2α (PERK-eIF2α) signaling pathway, subsequently phosphorylated cAMP response element binding protein (CREB) at the S129 and reduced the BDNF level, eventually leading to the impairment of synaptic transmission and depressive-like behaviors. Therefore, our study suggests that PERK-eIF2α acts as a critical target downstream of Homer1-mGluR5 complex to mediate chronic stress-induced depressive-like behaviors, and highlights them as a potential target for the treatment of mood disorder.

Hyperoside protects against chronic mild stress-induced learning and memory deficits.

Hyperoside (quercetin-3-O-b-d-galactosidepyranose) is a plant-derived flavonoid mainly found in fruits, fruit juices (most notably flavanols, flavanones, and anthocyanins) and Chinese traditional medicines. It has been applied to relieve pain and improve cardiovascular functions in clinic. However, the effects of hyperoside on cognitive impairment induced by chronic stress and the underlying molecular mechanisms remain unclear. In the current study, we used chronic mild stress (CMS) rats to investigate the effects of hyperoside on learning and memory and further explore the possible mechanisms. Our results demonstrated that hyperoside reduced the escape latency and the swimming distance of CMS rats in Morris water maze test and reversed depressive symptoms in forced swim test (FST) and sucrose preference test. In addition, hyperoside increased the expression of brain-derived neurotrophic factor (BDNF) in hippocampus of CMS rats without influencing the corticosterone (CORT) level in blood plasma. Furthermore, K252a, an inhibitor of the BDNF receptor TrkB, prevented the protective effects of hyperoside on learning and memory in CMS rats. Taken together, these results indicate that hyperoside reverses the cognitive impairment induced by CMS, which is associated with the regulation of BDNF signaling pathway.