Effect of phenylephrine rescue injection on hypotension after spinal anaesthesia for caesarean delivery when guided by both heart rate and SBP during an early warning window: A randomised controlled trial

BACKGROUND

Spinal anaesthesia is now the most common technique for caesarean delivery. However, because of the intermittent nature of noninvasive blood pressure (NIBP) measurements, maternal blood pressure may become hypotensive between the measurements. There is thus an inbuilt delay before the anaesthesiologist can intervene to counteract the hypotension. Based on the principle that changes in blood pressure can induce compensatory changes in the heart rate (HR), combining the NIBP with real-time HR, we designed two warning windows to predict hypotension and hypertension.

OBJECTIVE

To evaluate whether phenylephrine administration guided by these warning windows would help maintain haemodynamic stability.

SETTING

A teaching hospital.

DESIGN

A randomised controlled trial.

PATIENTS

One hundred and ten pregnant women scheduled for elective caesarean delivery were enrolled, from which, after exclusions, 86 were eligible for the study.

INTERVENTIONS

All eligible patients received a continuous intravenous infusion of phenylephrine as soon as spinal anaesthesia was initiated. Thereafter, patients were randomly assigned to two groups. In the test group (Win-Group): rescue phenylephrine administration was triggered by an early warning window of HR above 100 beats per minute (bpm) and SBP 90 to 110 mmHg; pausing the infusion phenylephrine was triggered by a HR lower than 60 bpm and SBP greater than 90 mmHg. In the control group, phenylephrine was guided by BP only when it appeared on the monitor: SBP less than 90 mmHg was the trigger for administering rescue phenylephrine; SBP greater than 110 mmHg was the trigger for pausing the phenylephrine infusion.

MAIN OUTCOME MEASURES

The primary outcome was incidence of hypotension. Secondary outcomes were the incidence of hypertension and other adverse haemodynamic events.

RESULTS

The incidence of hypotension was significantly lower in the Win-Group than in the BP-Group (27.8 vs. 66.7%, P  = 0.001). The minimum SBP was significantly higher in Win-Group than in BP-Group (93.9 ± 9.49 vs. 86.7 ± 11.16 mmHg, P   =  0.004). There was no significant difference in the incidence of hypertension between groups.

CONCLUSION

After spinal anaesthesia for caesarean delivery, when phenylephrine infusion is guided by HR along with BP from a warning window it effectively reduces the incidence of hypotension without any significant effect on incidence of hypertension.

TRIAL REGISTRATION

Chictr.org.cn; Identifier: ChiCTR 2100041812.

Itaconate alleviates anesthesia/surgery-induced cognitive impairment by activating a Nrf2-dependent anti-neuroinflammation and neurogenesis via gut-brain axis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common neurological complication of anesthesia and surgery in aging individuals. Neuroinflammation has been identified as a hallmark of POCD. However, safe and effective treatments of POCD are still lacking. Itaconate is an immunoregulatory metabolite derived from the tricarboxylic acid cycle that exerts anti-inflammatory effects by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In this study, we investigated the effects and underlying mechanism of 4-octyl itaconate (OI), a cell-permeable itaconate derivative, on POCD in aged mice.

METHODS

A POCD animal model was established by performing aseptic laparotomy in 18-month-old male C57BL/6 mice under isoflurane anesthesia while maintaining spontaneous ventilation. OI was intraperitoneally injected into the mice after surgery. Primary microglia and neurons were isolated and treated to lipopolysaccharide (LPS), isoflurane, and OI. Cognitive function, neuroinflammatory responses, as well as levels of gut microbiota and their metabolites were evaluated. To determine the mechanisms underlying the therapeutic effects of OI in POCD, ML385, an antagonist of Nrf2, was administered intraperitoneally. Cognitive function, neuroinflammatory responses, endogenous neurogenesis, neuronal apoptosis, and Nrf2/extracellular signal-related kinases (ERK) signaling pathway were evaluated.

RESULTS

Our findings revealed that OI treatment significantly alleviated anesthesia/surgery-induced cognitive impairment, concomitant with reduced levels of the neuroinflammatory cytokines IL-1β and IL-6, as well as suppressed activation of microglia and astrocytes in the hippocampus. Similarly, OI treatment inhibited the expression of IL-1β and IL-6 in LPS and isoflurane-induced primary microglia in vitro. Intraperitoneal administration of OI led to alterations in the gut microbiota and promoted the production of microbiota-derived metabolites associated with neurogenesis. We further confirmed that OI promoted endogenous neurogenesis and inhibited neuronal apoptosis in the hippocampal dentate gyrus of aged mice. Mechanistically, we observed a decrease in Nrf2 expression in hippocampal neurons both in vitro and in vivo, which was reversed by OI treatment. We found that Nrf2 was required for OI treatment to inhibit neuroinflammation in POCD. The enhanced POCD recovery and promotion of neurogenesis triggered by OI exposure were, at least partially, mediated by the activation of the Nrf2/ERK signaling pathway.

CONCLUSIONS

Our findings demonstrate that OI can attenuate anesthesia/surgery-induced cognitive impairment by stabilizing the gut microbiota and activating Nrf2 signaling to restrict neuroinflammation and promote neurogenesis. Boosting endogenous itaconate or supplementation with exogenous itaconate derivatives may represent novel strategies for the treatment of POCD.

Burden of lung cancer attributed to particulate matter pollution in China: an epidemiological study from 1990 to 2019

OBJECTIVES

The aim of this study was to examine the disease burden of lung cancer attributable to particulate matter (PM2.5) pollution in China from 1990 to 2019.

STUDY DESIGN

Data from the Global Burden of Disease Study 2019 were used to estimate the disease burden of tracheal, bronchus and lung cancer attributed to PM2.5 over time in China.

METHODS

Joinpoint regression models were applied to disability-adjusted life years (DALYs) to assess the time trends and estimate the impact of PM2.5 on the overall disease burden of lung cancer. Furthermore, age-period-cohort models were conducted to assess the relationships between lung cancer DALYs attributed to PM2.5 exposure and age, calendar period and birth cohort trends in China from 1990 to 2019.

RESULTS

Lung cancer DALYs attributable to household air pollution from solid fuels decreased with an average annual percent change (AAPC) of 2.9 % per 100,000 population, while those attributable to ambient particular matter pollution (APE) increased (AAPC: -4.7 % per 100,000 population) over the past 30 years. The burden of lung cancer in terms of DALYs in males was higher than in females, and it demonstrated an age-dependent increase. The period and cohort effects also had significant impacts on the DALYs rates of lung cancer attributable to APE, indicating an overall increase in lung cancer DALYs for all age groups in each year.

CONCLUSIONS

This study highlights the need for effective strategies to reduce PM2.5 exposure in China, particularly from outdoor sources. Gender differences and age, period and cohort effects observed in the study provide valuable insights into long-term trends of lung cancer burden attributed to PM2.5.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

Effect of opioid-free anesthesia on postoperative nausea and vomiting after gynecological surgery: a systematic review and meta-analysis

Background: Postoperative nausea and vomiting (PONV) is a common complication, that can reduce patient satisfaction and may lead to serious consequences, such as wound dehiscence. Many strategies have been proposed to prevent PONV; however, it remains common, especially in high-risk surgeries such as gynecological surgery. In recent years, opioid-free anesthesia has been widely studied because it minimizes adverse reactions of opioids, such as nausea, vomiting, and itching; however, conclusions have been inconsistent. Therefore, we conducted this meta-analysis to investigate the effects of opioid-free anesthesia on PONV in patients undergoing gynecological surgery. Methods: A systematic search of the PubMed, Web of Science, Cochrane Library, and Embase databases, from inception to 28 August 2023, was performed. Keywords and other free terms were used with Boolean operators (OR and, AND) to combine searches. This review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Six studies involving 514 patients who underwent gynecological surgery were included. The forest plot revealed that the incidence of PONV (risk ratio = 0.52; p < 0.00001) and consumption of postoperative antiemetics use (risk ratio = 0.64; p = 0.03) were significantly lower in the opioid-free anesthesia group. In addition, opioid-free anesthesia improved the quality of recovery (mean difference = 4.69; p < 0.0001). However, there were no significant differences in postoperative pain scores (mean difference = 0.05; p = 0.85), analgesic use (risk ratio = 1.09; p = 0.65), and the time of extubation (mean difference = -0.89; p = 0.09) between the opioid-free anesthesia and control groups. Conclusion: OFA reduces PONV and the use of antiemetic drugs. In addition, it improves the quality of postoperative recovery. However, OFA can not reduce the postoperative pain scores, analgesic use and the time of extubation. Due to the strength of the evidence, we cannot support OFA as an ideal anesthesia method in gynecological surgery, and the implementation of anesthesia strategies should be case-by-case. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=462044], identifier [CRD42023462044].

The Effects of Appropriate Perioperative Exercise on Perioperative Neurocognitive Disorders: a Narrative Review

Perioperative neurocognitive disorders (PNDs) are now considered the most common neurological complication in older adult patients undergoing surgical procedures. A significant increase exists in the incidence of post-operative disability and mortality in patients with PNDs. However, no specific treatment is still available for PNDs. Recent studies have shown that exercise may improve cognitive dysfunction-related disorders, including PNDs. Neuroinflammation is a key mechanism underlying exercise-induced neuroprotection in PNDs; others include the regulation of gut microbiota and mitochondrial and synaptic function. Maintaining optimal skeletal muscle mass through preoperative exercise is important to prevent the occurrence of PNDs. This review summarizes current clinical and preclinical evidence and proposes potential molecular mechanisms by which perioperative exercise improves PNDs, providing a new direction for exploring exercise-mediated neuroprotective effects on PNDs. In addition, it intends to provide new strategies for the prevention and treatment of PNDs.

Effects of intravenous glucocorticoids on postoperative delirium in adult patients undergoing major surgery: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

The effects of intravenous glucocorticoids on postoperative delirium (POD) in adult patients undergoing major surgery remain controversial. Therefore, we conducted this meta-analysis to assess whether intravenous glucocorticoids can decrease POD incidence in the entire adult population undergoing major surgery and its association with patients age, type of surgery, and type of glucocorticoid.

METHODS

We searched the relevant literature published before November 3, 2023, through Cochrane Library, PubMed, Embase, and Web of Science. The primary outcome was POD incidence. The risk ratio for the primary outcome was calculated using the Mantel-Haenszel method. The secondary outcomes included 30-day mortality, length of hospital stay, ICU duration, mechanical ventilation duration, and occurrence of glucocorticoid-related adverse effects (e.g., infection and hyperglycemia). This meta-analysis was registered in PROSPERO: CRD42022345997.

RESULTS

We included eight randomized controlled studies involving 8972 patients. For the entire adult population undergoing major surgery, intravenous glucocorticoids reduced the POD incidence (risk ratio = 0.704, 95% confidence interval, 0.519-0.955; P = 0.024). However, subgroups defined by type of surgery showed differential effects of glucocorticoids on POD. Intravenous glucocorticoids can not reduce POD incidence in adult patients undergoing cardiac surgery (risk ratio = 0.961, 95% confidence interval, 0.769-1.202; P = 0.728), with firm evidence from trial sequential analysis. However, in major non-cardiac surgery, perioperative intravenous glucocorticoid reduced the incidence of POD (risk ratio = 0.491, 95% confidence interval, 0.338-0.714; P < 0.001), which warrants further studies due to inconclusive evidence by trial sequence analysis. In addition, the use of glucocorticoids may reduce the mechanical ventilation time (weighted mean difference, -1.350; 95% confidence interval, -1.846 to -0.854; P < 0.001) and ICU duration (weighted mean difference = -7.866; 95% confidence interval, -15.620 to -0.112; P = 0.047).

CONCLUSIONS

For the entire adult population undergoing major surgery, glucocorticoids reduced the POD incidence. However, the effects of glucocorticoids on POD appear to vary according to the type of surgery. In patients receiving major non-cardiac surgery, glucocorticoid may be an attractive drug in the prevention of POD, and further studies are needed to draw a definitive conclusion. In cardiac surgery, intravenous glucocorticoids have no such effect.

Human umbilical cord-derived mesenchymal stem cells ameliorate perioperative neurocognitive disorder by inhibiting inflammatory responses and activating BDNF/TrkB/CREB signaling pathway in aged mice

BACKGROUND

Perioperative neurocognitive disorder (PND) is a key complication affecting older individuals after anesthesia and surgery. Failure to translate multiple pharmacological therapies for PND from preclinical studies to clinical settings has necessitated the exploration of novel therapeutic strategies. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) treatment has emerged as a promising therapeutic strategy for treating neurodegenerative diseases and has the potential to translate basic science into clinical practice. In this study, we investigated the effects and underlying mechanism of hUC-MSCs on PND in aged mice.

METHODS

hUC-MSCs were isolated from an infant umbilical cord and identified using flow cytometry and differentiation assays. We established PND model by undergoing aseptic laparotomy under isoflurane anesthesia maintaining spontaneous ventilation in eighteen-month-old male C57BL/6 mice. hUC-MSCs were slowly injected into mice by coccygeal vein before anesthesia. Cognitive function, systemic and neuroinflammatory responses, neuroplasticity, endogenous neurogenesis, and brain-derived neurotrophic factor (BDNF) were assessed. To determine the brain mechanisms underlying by which hUC-MSCs mediate their neuroprotective effects in PND, K252a, an antagonist of BDNF receptor, was administered intraperitoneally before surgery. Hippocampal BDNF/TrkB/CREB signaling pathway and metabolomic signatures were evaluated.

RESULTS

hUC-MSC treatment ameliorated the learning and memory impairment in aged mice with PND. The downstream effects were the suppression of systemic and hippocampal inflammation and restoration of neurogenesis and neuroplasticity dysregulation. Interestingly, the level of mature BDNF, but not that of proBDNF, was increased in the hippocampus after hUC-MSC treatment. Further analysis revealed that the improved cognitive recovery and the restoration of neurogenesis and neuroplasticity dysregulation elicited by exposure to hUC-MSCs were, at least partially, mediated by the activation of the BDNF/TrkB/CREB signaling pathway. Untargeted metabolomic further identified lipid metabolism dysfunction as potential downstream of the BDNF/TrkB/CREB signaling pathway in hUC-MSC-mediated neuroprotection for PND.

CONCLUSIONS

Our study highlights the beneficial effects of hUC-MSC treatment on PND and provides a justification to consider the potential use of hUC-MSCs in the perioperative period.

Case series of tracheal extubation in prone position after endoscopic retrograde cholangiopancreatography general anesthesia

OBJECTIVE

The study aims to present a 15-patient case series of tracheal extubation in the prone position after endoscopic retrograde cholangiopancreatography (ERCP) general anesthesia.

PATIENTS AND METHODS

Fifteen inpatients who underwent elective ERCP in our hospital were prospectively enrolled, and a series of case studies were conducted with the prone extubation technique after general anesthesia. All patients underwent routine operation of tracheal intubation under general anesthesia. After the surgery, when the train-of-four ratio (TOFr) ≥0.9, bispectral index (BIS) ≥80, tidal volume ≥6 ml/kg and the required actions could be performed, the endotracheal catheter was removed after sufficient negative pressure suction of oral secretions. After the endotracheal catheter was removed, the patient autonomously turned to the transport bed with the assistance of medical staff and was then admitted to the post-anesthesia care unit (PACU) for further observation. When the patient awoke, he had regained orientation, and presented stable vital signs, no nausea and vomiting, and no other discomfort symptoms, he/she was able to leave PACU and returned to the ward with a Steward score of ≥5.

RESULTS

All 15 patients who underwent ERCP elective surgery were successfully extubated in the prone position after surgery. Transient hypoxemia with SpO2 below 90% occurred in 2 of the 15 patients and returned to normal with oxygen mask administration. 7 patients had coughs and were without special treatment. Another 1 patient showed transient abnormal hemodynamic fluctuations after extubation, mean airway pressure (MAP) was higher than 20% of the baseline value, and hemodynamics was stable after drug treatment.

CONCLUSIONS

The prone extubation technique is feasible for ERCP general anesthesia patients. However, a larger sample size is needed to validate its safety and to verify whether there exist advantages of the extubation technique in a prone position over a supine position.

Impact of ankylosing spondylitis on stroke limited to specific subtypes: Evidence from Mendelian randomization study

Background

The relationship between Ankylosing Spondylitis (AS) and the risk of stroke is complex. Therefore, we utilized Two-Sample Mendelian randomization to examine the probable causal link between these two features.

Methods

The genetic instruments linked to AS were chosen from a summary-level genetic data set from the FinnGen consortium in people of European ancestry (1462 cases and 164,682 controls). Stroke and its subtypes were selected as outcomes, and the MEGASTROKE consortium population was used to identify the genetic associations of AS on stroke (40,585 cases and 406,111 controls), ischemic stroke (IS) (34,217 cases and 406,111 controls), and its subtypes including large artery stroke (LAS) (4373 cases and 146,392 controls), small vessel stroke (SVS) (5386 cases and 192,662 controls), and cardioembolic stroke (CES) (7193 cases and 204,570 controls). Intracerebral hemorrhage (ICH) (1687 cases and 201,146 controls) data set from the FinnGen consortium was also used. To obtain the casual estimates, the inverse variant weighted (IVW) method was mainly used. By examining the heterogeneity and pleiotropy of particular single nucleotide polymorphisms (SNPs), the robustness of the results was also examined.

Results

There was no evidence found to prove the correlation between genetically predicted AS and stroke (odds ratio [OR] 1.014; 95% confidence interval [CI] 0.999-1.031; P = 0.063), ICH (OR 1.030; 95% CI 0.995-1.067; P = 0.090), and IS (OR 1.013; 95% CI 0. 998-1.030; P = 0.090). In terms of the different subtypes of IS, there was strong evidence of positive causal inferences on CES (OR 1.051; 95% CI 1.022-1.081; P = 0.001), and suggestive evidence of positive causal inferences on LAS (OR 1.042; 95% CI 1.003-1.082; P = 0.033), while it was not significant for SVS (OR 1.010; 95% CI 0.975-1.047; P = 0.563).

Conclusion

This study suggests that the possible causative impact of genetically predicted AS on stroke may be restricted to the CES and LAS subtypes.

Preventing Spinal Hypotension During Cesarean Birth With Two Initial Boluses of Norepinephrine in Chinese Parturients: A Randomized, Double-Blind, Controlled Trial

BACKGROUND

Norepinephrine is effective in preventing spinal hypotension during cesarean birth; however, an optimal regimen has not been determined. We hypothesized that an initial bolus of norepinephrine improves efficacy of spinal hypotension prophylaxis beyond continuous norepinephrine alone.

METHODS

In this double-blind, controlled study, 120 patients scheduled for cesarean birth under spinal anesthesia were randomly allocated to receive a norepinephrine bolus at 0.05 or 0.10 μg/kg, followed by norepinephrine infusion at a rate of 0.05 μg·kg -1 ·min -1 . The primary outcome was the frequency of spinal hypotension during cesarean birth. The doses of the rescue drug (phenylephrine), frequency of nausea or vomiting, duration of hypotension, frequency of intraoperative hypertension, frequency of bradycardia, and fetal outcomes were also compared.

RESULTS

One-hundred-fifteen patients were included in the analysis. Compared with the 0.05 μg/kg group, the frequency of spinal hypotension was lower in the 0.10 μg/kg group (20.7% vs 45.6%; odds ratio [OR], 0.31; 95% confidence interval (CI), 0.14-0.71; P = .004). Fewer rescue doses of phenylephrine (0 [0,0] vs 0 [0,80]; 95% CI for the difference, 0 (0-0); P = .006) were required, and the frequency of nausea or vomiting was lower (5.2% vs 17.5%; OR, 0.26; 95% CI, 0.07-0.99; P = .04) in the 0.10 μg/kg group. The duration of hypotension was shorter in the 0.10 μg/kg group than that in the 0.05 μg/kg group (0 [0,0] vs 0 [0,2]; 95% CI for the difference, 0 [0-0]; P = .006). The incidence of intraoperative hypertension, frequency of bradycardia, and fetal outcomes were comparable between the 2 groups.

CONCLUSIONS

With a fixed-rate norepinephrine infusion of 0.05 μg·kg -1 ·min -1 , the 0.10 μg/kg initial bolus was more effective in reducing the incidence of spinal hypotension compared with the 0.05 μg/kg initial bolus.

Single-cell RNA sequencing reveals intra-tumoral heterogeneity of glioblastoma and a pro-tumor subset of tumor-associated macrophages characterized by EZH2 overexpression

BACKGROUND

Glioblastoma (GBM) is a highly heterogeneous disease with poor clinical outcome.

AIM

To comprehensively dissect molecular landscape of GBM and heterogeneous distribution and potential role of Enhancer of zeste homolog 2 (EZH2) in tumor microenvironment (TME).

METHODS

Single-cell RNA sequencing (scRNA-seq) analysis was performed in GBM samples from 8 patients. Deconvolution analysis, immunofluorescence (IF) microscopy, reverse-transcription quantitative polymerase chain reaction (RT-qPCR), colony formation experiments, and Cell Counting Kit-8 (CCK-8) assays were performed to confirmed the potential role of EZH2 in TME cells.

RESULTS

Malignant cells exhibited remarkable heterogeneity in abnormal metabolic patterns. A mesenchymal-2-like (MES2-like) GBM subcluster with glial-immune dual feature was firstly discovered, which were associated with highly activated hallmark pathways, immune evasion associated transcription factor (IRF8), and poor survival. The oncogene, EZH2, was heterogeneously expressed in malignant cells and immune cells consistent with proliferative genes, cell-cycle transcription factors, and similar activated hallmark pathways. In a tumor-associated macrophages (TAMs) subset (macrophage.3), EZH2 was highly expressed with similar changes of transcriptomic dynamics with cell-cycle genes and macrophages M2-phetotype genes. In addition, the subset tightly interacted with malignant cells. Deconvolution analysis showed increased abundance of the subset in GBM compared to low-grade glioma (LGG) and significant association with worse prognosis. Functional verification experiments confirmed the pro-tumor role of TAMs with EZH2 overexpression in GBM.

CONCLUSIONS

Our study illustrated a MES2-like GBM subcluster characterized by glial-immune dual feature and highlighted the pro-tumor role of a TAMs subset characterized by EZH2 overexpression.

Biomineralized hybrid nanodots for tumor therapy via NIR-II fluorescence and photothermal imaging

Chemodynamic therapy (CDT) is an emerging and promising therapeutic strategy that suppresses tumor growth by catalytically converting intracellular hydrogen peroxide (H2O2) into highly-reactive hydroxyl radicals (•OH). However, the inherent substrate of H2O2 is relatively insufficient to achieve desirable CDT efficacy. Therefore, searching for integrated therapeutic methods with synergistic therapeutic modality is especially vital to augment therapeutic outcomes. Herein, we reported nanodot- CuxMnySz @BSA@ICG (denoted as CMS@B@I) and bovine serum albumin (BSA)-based biomineralization CuxMnySz (CMS) loaded with photodynamic agent-indocyanine green (ICG). CMS@B@I converts endogenous hydrogen peroxide (H2O2) into highly active hydroxyl radical (•OH) via Fenton reaction, and effectively produces reactive oxygen species (ROS) after being exposed to 808 nm laser irradiation, attributable to the excellent photodynamic agent-ICG. This results in eliciting a ROS storm. Additionally, CMS@B@I exhibits a superior photothermal effect under NIR-II 1064 nm laser irradiation to enhance tumor CDT efficacy. The NIR-II fluorescence imaging agent of ICG and the excellent photothermal effect of CMS@B@I are highly beneficial to NIR-II fluorescence and infrared thermal imaging, respectively, resulting in tracing the fate of CMS@B@I. This study attempts to design a bimodal imaging-guided and photothermal-enhanced CDT nanoagent for augmenting tumor catalytic therapy.

Lower preoperative serum uric acid level may be a risk factor for postoperative delirium in older patients undergoing hip fracture surgery: a matched retrospective case-control study

Background

Postoperative delirium (POD) is a common complication after hip fracture surgery that is associated with various short- and long-term outcomes. The mechanism of POD may be associated with the oxidative stress process. Uric acid has been shown to provide a neuroprotective effect in various neurodegenerative diseases through its antioxidant properties. However, it is unclear whether lower preoperative serum uric acid levels are associated with the development of POD after hip fracture surgery. Therefore, this study assessed the association of lower preoperative uric acid levels in patients with POD during hospitalization.

Methods

This is a matched retrospective case-control study that included 96 older patients (≥65 y) who underwent hip fracture surgery. POD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Patients diagnosed with POD (cases) were matched 1:1 with patients without POD (controls) on the basis of age, sex, and anesthesia type. The relationship between preoperative uric acid and POD was analyzed by multivariable analysis.

Results

The POD and non-POD groups each had 48 patients. In the univariate analysis, lower log preoperative serum uric acid value, higher neutrophil-to-lymphocyte ratio, and cerebrovascular disease were more likely in patients with POD than in those with no POD. Multivariable conditional logistic regression analysis showed that lower log preoperative serum uric acid (adjusted odds ratio [aOR], 0.028; confidence interval [CI], 0.001–0.844; p = 0.040), higher neutrophil-to-lymphocyte ratio (aOR, 1.314; 95% CI, 1.053–1.638; p = 0.015), and increased surgery duration (aOR, 1.034; 95% CI, 1.004–1.065; p = 0.024) were associated with increased risk of POD.

Conclusions

Lower preoperative serum uric acid levels may be an independent risk factor for POD after adjustment for possible confounding factors. However, large prospective studies are needed to confirm this finding.

[Low-frequency pulsed electromagnetic fields promote osteoblast mineralization and maturation of rats through the PC2/sAC/PKA/CREB signaling pathway]

OBJECTIVE

To explore whether the effect of low-frequency pulsed electromagnetic fields (PEMFs) in promoting osteoblast mineralization and maturation is related to the primary cilia, polycystin2 (PC2) and sAC/PKA/CREB signaling pathway.

METHODS

We detected the expression levels of PC2, sAC, PKA, CREB and their phosphorylated proteins in primary rat calvarial osteoblasts exposed to 50 Hz 0.6 mT PEMFs for 0, 5, 15, 30, 60, 90, and 120 min. We blocked PC2 function with amiloride hydrochloride and detected the changes in the activity of sAC/PKA/CREB signal pathway and the mineralization and maturation of the osteoblasts. These examinations were repeated in the osteoblasts after specific knockdown of PC2 via RNA interference and were the co-localization of PC2, sAC, PKA, CREB and their phosphorylated proteins with the primary cilia were using immunofluorescence staining. The expressions of PC2 and the signaling proteins of sAC/PKA/CREB pathway were detected after inhibition of primary ciliation by RNA interference.

RESULTS

The expression levels of PC2, sAC, p-PKA and p- CREB were significantly increased in the osteoblasts after exposure to PEMFs for different time lengths (P < 0.01). Blocking PC2 function or PC2 knockdown in the osteoblasts resulted in failure of sAC/PKA/CREB signaling pathway activation and arrest of osteoblast mineralization and maturation. PC2, sAC, p-PKA and p-CREB were localized to the entire primary cilia or its roots, but PKA and CREB were not detected in the primary cilia. After interference of the primary cilia, PEMFs exposure no longer caused increase of PC2 expression and failed to activate the sAC/PKA/CREB signaling pathway or promote osteoblast mineralization and maturation.

CONCLUSION

PC2, located on the surface of the primary cilia of osteoblasts, can perceive and transmit the physical signals from PEMFs and promote the mineralization and maturation of osteoblasts by activating the PC2/ sAC/PKA/CREB signaling pathway.

α7 Nicotinic Acetylcholine Receptor May Be a Pharmacological Target for Perioperative Neurocognitive Disorders

Background: The α7 nicotinic acetylcholine receptor (α7nAChR) is a promising therapeutic target in neurodegenerative diseases. This study examined the effects of surgery and anesthesia on α7nAChR expression in the central nervous system and determined the mechanisms by which α7nAChR mediates neuroprotection in perioperative neurocognitive disorders (PNDs) in aged mice.

Methods: Eighteen-month-old male C57BL/6J mice underwent aseptic laparotomy under isoflurane anesthesia, maintaining spontaneous ventilation to establish the PNDs model. Agonists and antagonists of the α7nAChR and tropomyosin receptor kinase B (TrkB) receptors were administered before anesthesia. The α7nAChR expression, peripheral as well as hippocampal interleukin-1β (IL-1β), and the brain-derived neurotrophic factor (BDNF) levels were assessed. Separate cohorts of aged mice were tested for cognitive decline using the Morris water maze (MWM).

Results: Surgery and anesthesia significantly suppressed α7nAChR expression in the hippocampus and cortex. Surgery-induced IL-1β upregulation in the serum as well as hippocampus and hippocampal microglial activation were reversed by the α7nAChR agonist. A significant reduction in the hippocampal BDNF levels were also observed. The α7nAChR stimulation reversed, and α7nAChR suppression promoted BDNF reduction in the hippocampus. Blocking the BDNF/TrkB signaling pathway abolished α7nAChR-induced neuroprotection in PNDs, as evidenced by poor cognitive performance in the MWM test.

Conclusions: These data reveal that α7nAChR plays a key role in PNDs. The mechanisms of the anti-inflammatory pathway and BDNF/TrkB signaling pathways are involved in α7nAChR-meidiated neuroprotection in PNDs.

Case Report and Preliminary Exploration: Protection of Supraclavicular Nerve Branches during Internal Fixation of Clavicular Fractures through Preoperative Ultrasound Localization

Introduction

Protecting the supraclavicular nerve during internal fixation of clavicular fractures can reduce numbness in its innervation area after surgery. Previous methods for supraclavicular nerve protection are empirical, time-consuming, and approximate. In this report, we verified the feasibility of using ultrasound for percutaneous localization of the terminal branches of the supraclavicular nerve and the feasibility of an ultrasound-guided skin flap reserve technique for nerve protection.

Case Presentations

A high-frequency linear array probe was used in three cases to trace the supraclavicular nerve from its origin at the superficial cervical plexus on the surface of the clavicle. In the first case, the feasibility of percutaneous ultrasound localization of the terminal branches of the supraclavicular nerve was determined by performing an ultrasound-guided nerve block. In the second case, the feasibility of this method was determined by directly isolating this nerve under direct vision. In the third case, after the ultrasound localization, the nerves were protected by intraoperative skin retention. In the first case, skin anesthesia of the innervation area of the intermediate branch of the supraclavicular nerve was achieved. In the second case, the part of the nerve that crosses the surface of the clavicle was quickly found and successfully protected, and no obvious abnormal skin sensations were noted after the operation. In the third case, there was no abnormal sensation in most of the associated skin except for the innervation area of the lateral branch of the supraclavicular nerve.

Conclusions

The medial and intermediate branches of the supraclavicular nerve could be located over the skin by ultrasound, and this could be helpful in quickly isolating these nerves intraoperatively. Retaining the corresponding skin can protect the function of these nerve branches and effectively reduce the area of skin numbness after surgery.

[Identification of traditional Chinese drugs containing active ingredients for treating myocardial infarction and analysis of their therapeutic mechanisms by network pharmacology and molecular docking]

OBJECTIVE

To identify traditional Chinese drugs that contain active ingredients for treatment of myocardial infarction (MI) and explore their therapeutic mechanisms using network pharmacology and molecular docking technology.

METHODS

The TCMSP database was used for screening the traditional Chinese drugs containing active ingredients for treating MI, and the related targets of MI and the candidate drugs were obtained from Genecards, OMIM, PharmGkb and PharmMapper databases. The common target network of the drug targets and disease targets was established using Venny2.1.0 software. GO and KEGG signal pathway enrichment analysis of the common targets was performed, and the protein-protein interaction (PPI) network was constructed for the targets. The targets in the PPI network were analyzed to identify the key targets, for which GO and KEGG pathway enrichment analyses were performed. Molecular docking was performed for the candidate ingredients and the key targets, and a total score ≥6 was used as the criteria for screening the therapeutic ingredients and their docking binding with key targets was verified. A human umbilical vein endothelial cell (HUVEC) model of oxygen-glucose deprivation (OGD) was used to validate the candidate ingredients and the key therapeutic targets for MI by Western blotting.

RESULTS

Our analysis identified Salvia miltiorrhiza and Dalbergiae odoriferae as the candidate drugs rich in active ingredients for treatment of MI. These ingredients involved 16 key therapeutic targets for MI, which participated in such biological processes as inflammatory response, angiogenesis, energy metabolism and oxidative stress and the pathways including HIF-1, VEGF, and TNF pathways. Sclareol and PTGS2 in Salvia miltiorrhiza and formononetin and KDR in Dalbergiae odoriferae all had high docking total scores. Western blotting showed that at medium and high doses, sclareol significantly inhibited PTGS2 expression and formononetin promoted KDR expressions in the cell models in a dose-dependent manner (P < 0.05).

CONCLUSION

Both Salvia miltiorrhiza and Dalbergiae odoriferae have good therapeutic effects on MI. Sclareol in Salvia miltiorrhiza and formononetin in Dalbergiae odoriferae regulate the expressions of KDR and PTGS2, respectively, to modulate the inflammatory response, angiogenesis, oxidative stress and energy metabolism and thus produce myocardial protective effects.

[The effect and mechanism of exosomes derived from human amniotic epithelial cells on the proliferation and migration of HaCaT in high glucose environment]

Objective: To investigate the effect and mechanism of exosomes derived from human amniotic epithelial cells (hAEC-Exos) on the proliferation and migration of HaCaT in high glucose environment. Methods: The experimental research method was adopted. The amniotic membrane tissue was collected from 10 healthy pregnant women at full term delivery in the Department of Obstetrics and Gynecology of Fujian Medical University Union Hospital from January to June 2019, and the primary human amniotic epithelial cells (hAECs) were isolated. The growth status and morphological changes of the primary hAECs on the 2nd, 4th, and 7th day of culture were observed, and the expressions of the cells surface markers of CD73, CD90, CD29, CD34, and human leukocyte antigen DR (HLA-DR). The 2nd to 4th passages of hAECs were used in the following experiments. The hAEC-Exos were separated by ultracentrifugation method. The HaCaT and hAEC-Exos were co-cultured for 3 h, and the uptake of hAEC-Exos by HaCaT was observed by inverted fluorescence microscopy. The HaCaT were divided into phosphate buffer solution (PBS) group and hAEC-Exos group or dimethyl sulfoxide (DMSO)+PBS group, DMSO+hAEC-Exos group, and LY294002+hAEC-Exos group, which were dealt correspondingly, with 3 wells in each group. Cell counting kit 8 (CCK-8) method was used to detect cell proliferation activity after 0 (immediately), 12, 24, 36, 48, and 60 h of culture. The scratch test was conducted to detect the scratch healing at 0, 24, 48, and 72 h after the scratch, and the scratch healing rate was calculated, respectively. The Transwell experiment was conducted to detect the number of transmembrane cells after 48 h of culture. The Western blotting was used to detect the protein expressions of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), protein kinase B (Akt), and phosphorylated Akt (p-Akt) related to phosphatidylinositol 3-kinase-Akt-mTOR (PI3K-Akt-mTOR) pathway after 24 h of culture. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and independent sample t test. Results: Most of the primary hAECs were oval and uniform in size on the 2nd day of culture. The hAECs were arranged in a typical cobblestone-like monolayer on the 4th and 7th day of culture. The primary hAECs highly expressed CD73, CD90, and CD29 of mesenchymal stem cell related surface markers, and were with no or low expressions of CD34 and HLA-DR of hematopoietic stem cell related surface markers. After 3 h of culture, hAEC-Exos were successfully endocytosed by HaCaT into the cytoplasm and gathered around the nucleus. After 12, 24, 36, 48, and 60 h of culture, the proliferation activity of HaCaT in hAEC-Exos group was significantly higher than that in PBS group (t=3.691, 10.861, 12.121, 10.531, 14.931, P<0.01). At 24, 48, and 72 h after scratch, the scratch healing rates of HaCaT in PBS group were significantly lower than those in hAEC-Exos group (t=3.342, 6.427, 5.485, P<0.05 or P<0.01). After 48 h of culture, the number of transmembrane HaCaT in hAEC-Exos group was significantly more than that in PBS group (t=5.385, P<0.01). After 24 h of culture, the protein expressions of p-mTOR and p-Akt in HaCaT of hAEC-Exos group were significantly higher than those in PBS group (t=4.240, 5.586, P<0.01), while the protein expressions of mTOR and Akt in HaCaT of the two groups were similar (P>0.05). After 24 h of culture, the protein expressions of p-mTOR and p-Akt in HaCaT of DMSO+hAEC-Exos group were significantly higher than those in DMSO+PBS group (t=6.155, 8.338, P<0.01) and LY294002+hAEC-Exos group (t=5.030, 3.960, P<0.01), while the protein expressions of mTOR and Akt in HaCaT of the three groups were similar (P>0.05). The proliferation activity of HaCaT in DMSO+hAEC-Exos group at 12, 24, 36, 48, and 60 h of culture was 0.78±0.05, 1.23±0.07, 1.60±0.09, 1.86±0.09, and 2.03±0.08, which was significantly higher than 0.46±0.04, 0.69±0.07, 0.98±0.08, 1.16±0.08, and 1.26±0.11 in DMSO+PBS group (t=4.376, 7.398, 8.488, 9.766, 10.730, P<0.01). The proliferation activity of HaCaT in DMSO+hAEC-Exos group at 24, 36, 48, and 60 h was significantly higher than 0.96±0.09, 1.20±0.08, 1.39±0.08, and 1.55±0.10 in LY294002+hAEC-Exos group (t=3.639, 5.447, 6.605, 6.693, P<0.05 or P<0.01). The scratch healing rates of HaCaT in DMSO+hAEC-Exos group at 24, 48, and 72 h after scratch were significantly higher than those in DMSO+PBS group (t=4.003, 6.349, 7.714, P<0.01) and LY294002+hAEC-Exos group (t=3.805, 4.676, 4.067, P<0.05 or P<0.01). After 48 h of culture, the number of transmembrane HaCaT in DMSO+hAEC-Exos group was significantly more than that in DMSO+PBS group and LY294002+hAEC-Exos group, respectively (t=7.464, 1.232, P<0.01). Conclusions: PI3K-Akt-mTOR pathway can promote the proliferation and migration of HaCaT in high glucose environment by mediating hAEC-Exos.

Factors associated with Scrub Typhus infection: A case-control study from Luhe, China

INTRODUCTION

Scrub typhus (ST) is an acute febrile infection and remains a significant health problem globally. This study aimed to determine the factors associated with ST infection in Luhe District, China.

MATERIAL AND METHODS

The case-control study was conducted among 116 cases identified through passive surveillance systems over three years.The control subjects were 232 living in the same village for more than six months without any history of ST infection were selected by matching to the age (within 5-years) and identified through active surveillance. Statistical analyses were performed using SPSS v. 25.0 for Windows (IBM SPSS, Chicago, IL, USA).

RESULTS

The mean age of confirmed persons was 58.1(SD=10.15) years, while control subjects were 56.14 (11.57).There is no significant difference in gender, age, education, and occupations between case and control. Farmers had the most significant number of cases among occupational groups. The three factors that were significantly associated with an increased odds of having ST infection are bundling or moving waste straw (OR: 1.94, 95%CI; 0.99,381), morning exercise in the park or field (OR: 4.74 95%CI; 1.19, 18.95), and working as labourer in the vegetable field (OR:1.02, 95%CI:1.02,3.19).

CONCLUSIONS

Our findings suggested establishing a prevention and control strategy for these groups to lower ST development risk.

Ultrasound-Guided Regional Anesthesia Under Sedation for Radical Mastectomy in an SAS Patient: A Case Report

Radical mastectomy is commonly performed under general anesthesia, and regional block is often used as assisted or postoperative analgesia. We herein report a case of successful radical mastectomy with severe aortic stenosis (SAS) by using ultrasound-guided regional anesthesia under sedation. A 66-year-old female with an American Society of Anesthesiology physical status IV; limited functional capacity with <4 metabolic equivalents; a lump (10 cm × 8 cm) in the right breast with skin breakage and infection; and a history of hypertension, diabetes, atrial fibrillation, and SAS, underwent lump-resection and rapid pathological examination by biopsy. Considering a high-risk of significant mortality, we used ultrasound-guided regional block to avoid general anesthesia. We performed the right thoracic paravertebral nerve block (TPVB), subclavicular brachial plexus block, and pectoralis plane block (PECS 1). Patient tolerated the procedure well with no significant hemodynamic changes. Nevertheless, when the axillary lymph nodes were wiped, discharge was observed from the patient’s upper limbs. We inserted the laryngeal mask airway combined with low-dose sevoflurane inhalation sedation. The operation was successfully completed, and the patient was revived with steady hemodynamics and good prognosis. In the present case, radical mastectomy with SAS was performed successfully using ultrasound-guided regional anesthesia under sevoflurane sedation. Despite some potential limitations, this case report can serve as a reference for other anesthetists.

Case Report: Pink Urine Syndrome Following Exposure to Propofol: A Rare, Impressive but Benign Complication

Drug-induced changes in urine color induced by drugs may have clinical significance. Pink urine syndrome (PUS), which has been associated with urinary uric acid (UA) disorders, is most frequently reported in patients with morbid obesity undergoing gastric bypass surgery and/or from propofol anesthesia use in those who potentially have preexisting UA metabolism disorders. However, PUS has rarely occurred following exposure to propofol in non-obese patients, and literature on long-term follow-up after PUS is scarce. We report a case of PUS induced by propofol in a previously healthy non-obese woman after undergoing thoracoscopic wedge resection of pulmonary nodules under general anesthesia using propofol. The patient suddenly developed pink urine 4 h after surgery. A pink sediment rapidly precipitated at the bottom of the test tube following centrifugation of the urine. Amorphous, colorless UA-like crystals were identified under a polarizing microscope. The diagnosis of PUS was confirmed by examining the urinary UA concentration. The patient recovered and as followed-up for 1 month, during which she did not experience any urinary complications. To our knowledge, this is the first report to describe in detail a case of PUS caused by propofol in a non-obese patient with follow-up. PUS is usually benign and can resolve by rapidly on administering lactated Ringer’s solution; however, the potential risk of urinary complications, particularly UA lithiasis, should be fully realized.

Association of Carotid Plaque and Serum Lipoprotein-Associated Phospholipase A2 (LP-PLA2) with Postoperative Delirium in Geriatric Patients Undergoing Hip Replacement: A Prospective Cohort Study

BACKGROUND The aim of this study was to investigate the relationships among carotid plaque (CP), serum lipoprotein-associated phospholipase (LP-PLA2), and POD in elderly patients. MATERIAL AND METHODS Sixty-two elderly patients undergoing hip replacement with spinal-epidural anesthesia were divided into CP and non-CP groups based on the preoperative presence or absence of carotid atherosclerotic plaques, as assessed by ultrasound. POD was diagnosed by means of the Confusion Assessment Method (CAM). Blood samples were collected (preoperatively, postoperatively, and postoperative day 2) for the assessment of serum LP-PLA2 by enzyme-linked immunosorbent assay. The CP group was further divided into POD and no-POD subgroups based on the occurrence of POD. RESULTS The incidence of POD was higher in the CP group than in the non-CP group (P0.05), it was higher in the CP group than in the non-CP group postoperatively and on postoperative day 2 (P0.05), but was significantly higher in the POD subgroup than in the no-POD subgroup on postoperative day 2 (P<0.05). Furthermore, the LP-PLA2 level on postoperative day 2 was an independent risk factor for POD (odds ratio: 1.03, 95% confidence interval: 1.00-1.07). CONCLUSIONS The preoperative presence of carotid plaque is closely associated with a higher incidence of POD. The potential mechanism may involve the increased expression of LP-PLA2 in the serum, which can lead to plaque destabilization and subsequent inflammatory cascades.

KCNMA1-AS1 attenuates apoptosis of epithelial ovarian cancer cells and serves as a risk factor for poor prognosis of epithelial ovarian cancer

OBJECTIVE

To explore the role of KCNMA1-AS1 in epithelial ovarian cancer (EOC) and its underlying mechanism.

PATIENTS AND METHODS

We first screened out the differentially expressed lncRNAs (KCNMA1-AS1) in the GEO (gene expression omnibus) database. The relationship between KCNMA1-AS1 expression and prognosis of EOC with different pathological types was analyzed by meta-analysis. Subsequently, KCNMA1-AS1 expressions in EOC tissues and normal ovarian tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between KCNMA1-AS1 level with progression-free survival (PFS) and overall survival (OS) of EOC was analyzed. Furthermore, proliferation and migration of EOC cells transfected with the corresponding plasmids were analyzed by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. Apoptosis-related genes in EOC cells were detected by Western blot.

RESULTS

KCNMA1-AS1 was a risk factor for prognosis in high-grade, advanced and serous EOC. Upregulated KCNMA1-AS1 was found in EOC tissues than that of normal tissues, showing the diagnostic potential of KCNMA1-AS1 in EOC. Statistical analysis indicated that KCNMA1-AS1 was not correlated with the DFS, OS, age, histological type, lymph node metastasis and recurrence, but related to FIGO stage of EOC patients. For in vitro experiments, the proliferation and migration of were enhanced, and apoptosis of HO8910 cells overexpressing KCNMA1-AS1 was inhibited. Furthermore, elevated expressions of Caspase-3 and Caspase-9, as well as reduced expression of Bcl-xL, were observed after KCNMA1-AS1 knockdown in EOC cells.

CONCLUSIONS

KCNMA1-AS1 is overexpressed in EOC and negatively correlated with its prognosis. KCNMA1-AS1 participates in the occurrence and development of EOC by promoting proliferation, migration and inhibiting apoptosis of ovarian cancer cells via apoptosis pathway.

Anesthetic management of tracheal laceration from traumatic dislocation of the first rib: a case report and literature of the review

Background

Tracheobronchial lacerations from trauma can be life-threatening and present significant challenges for safe anesthetic management. Early recognition of tracheal injuries and prompt airway control can be lifesaving.

Case presentation

A 56-year-old man with no significant medical history presented with difficulty breathing after a blunt trauma to his chest to the emergency room and was diagnosed with dislocation of the first rib and tracheal laceration after a chest tomography (CT) study. Subcutaneous emphysema in neck area quickly worsened indicating continuous air leak. Emergent surgical repair was scheduled. General anesthesia with maintaining spontaneous ventilation was performed and a 5.5 mm endotracheal tube was placed under the guidance of flexible bronchoscopy. Depth of anesthesia was maintained to achieve a Bispectral Index Score of 40–60. Once the offending first rib was removed, a 7.5 mm endotracheal tube was inserted distal to the laceration site with the guidance of flexible bronchoscopy. Once confirmed location of the endotracheal tube, cisatracurium was administered intravenously and the patient was managed on mechanical ventilation with interval positive pressure ventilation. The operation was successful and he was transferred to the ICU intubated. He then received elective surgical repairs for sternum fracture, multiple rib fractures and hemopneumothorax under general anesthesia on day 5 after the first surgery and was extubated on postoperative day 7. The subsequent course was uneventful. Comprehensive rehabilitation was done for 2 weeks and he was discharged home on postoperative day 41.

Conclusions

Early diagnosis and multidisciplinary collaborations are keys to the successful management of this patient. Flexible bronchoscopy is particularly useful in airway management for urgent trachea tracheal laceration repair.

Nicotine-Induced Neuroprotection against Cognitive Dysfunction after Partial Hepatectomy Involves Activation of BDNF/TrkB Signaling Pathway and Inhibition of NF-κB Signaling Pathway in Aged Rats

Introduction

The main purpose of this study was to investigate the effects and possible mechanisms of nicotine pre-treatment on postoperative cognitive dysfunction (POCD) in aged rats.

Methods

Nicotine (0.5 mg/kg) was given i.p. immediately after anesthesia induction. After the Morris water maze test was used to evaluate the rats' spatial learning and memory, serum and hippocampal tissues were harvested 1 and 3 days after intervention. Inflammatory cytokines in the serum were evaluated by Enzyme-linked Immunosorbent Assay (ELISA). Brain-derived neurotrophic factor (BDNF), p-TrkB, neuroinflammation cytokines, NF-κB p65, and cleaved caspase-3 were measured by western blotting; neuronal apoptosis in the hippocampal CA1 region was also evaluated by TUNEL staining.

Results

We found that nicotine markedly attenuated the POCD and reduced the elevated levels of inflammatory cytokines in the serum, including IL-1β and high mobility group box-1 (HMGB1), on postoperative day 1. Additionally, nicotine suppressed the surgery-induced release of IL-1β, TNF-ɑ, HMGB1, and NF-κB p65 in the hippocampus on postoperative day 1 and day 3. In addition, operated rats displayed lower BDNF and p-TrkB in the hippocampus on postoperative day 1, returning to baseline by postoperative day 3. However, nicotine pre-treatment clearly reversed the surgical stress-induced decrease in both BDNF and p-TrkB expression in the hippocampus. Furthermore, nicotine pre-treatment significantly alleviated the surgery-induced increase in the neuronal apoptosis in the hippocampus on postoperative day 1 and day 3.

Conclusions

Our results showed that nicotine-induced neuroprotection against POCD may involve activation of the BDNF/TrkB signaling pathway and inhibition of the NF-κB signaling pathway.

Implications

Nicotine has long been considered a potent therapeutic agent for neuroprotection. This study reported the positive effect of nicotine treatment on cognitive dysfunction after partial hepatectomy in aged rats. Furthermore, the underlying mechanism may involve activation of the BDNF/TrkB signaling pathway and inhibition of the NF-κB signaling pathway in the hippocampus.