Acute-phase serum superoxide dismutase level as a predictive biomarker for stroke-associated infection

REDOX Imbalance and Oxidative Stress in the Intervertebral Disc: The Effect of Mechanical Stress and Cigarette Smoking on ER Stress and Mitochondrial Dysfunction

Low back pain is a widespread condition that significantly impacts quality of life, with intervertebral disc degeneration (IDD) being a major contributing factor. However, the underlying mechanisms of IDD remain poorly understood, necessitating further investigation. Environmental risk factors, such as mechanical stress and cigarette smoke, elevate reactive oxygen species levels from both endogenous and exogenous sources, leading to redox imbalance and oxidative stress. The endoplasmic reticulum (ER) and mitochondria, two key organelles responsible for protein folding and energy production, respectively, are particularly vulnerable to oxidative stress. Under oxidative stress conditions, ER stress and mitochondrial dysfunction occur, resulting in unfolded protein response activation, impaired biosynthetic processes, and disruptions in the tricarboxylic acid cycle and electron transport chain, ultimately compromising energy metabolism. Prolonged and excessive ER stress can further trigger apoptosis through ER-mitochondrial crosstalk. Given the unique microenvironment of the intervertebral disc (IVD)-characterized by hypoxia, glucose starvation, and region-specific cellular heterogeneity-the differential effects of environmental stressors on distinct IVD cell populations require further investigation. This review explores the potential mechanisms through which environmental risk factors alter IVD cell activities, contributing to IDD progression, and discusses future therapeutic strategies aimed at mitigating disc degeneration.

Assessing the predictive value of time-in-range level for the risk of postoperative infection in patients with type 2 diabetes: a cohort study

Aim

To analyze the correlation between preoperative time-in-range (TIR) levels and postoperative infection in patients with type 2 diabetes mellitus (T2DM) and to evaluate the value of the TIR as a predictor of postoperative infection in patients with T2DM.

Methods

A total of 656 patients with T2DM during the perioperative period were divided into a TIR standard group (TIR≥70%) and a TIR nonstandard group (TIR<70%) according to the TIR value. Modified Poisson regression was used to analyze postoperative risk factors in patients with T2DM. All patients were subsequently divided into a training set and a validation set at a ratio of 7:3. LASSO regression and the Boruta algorithm were used to screen out the predictive factors related to postoperative infection in T2DM patients in the training set. The discrimination and calibration of the model were evaluated by the area under the receiver operating characteristic curve (ROC) and calibration curve, and the clinical net benefit of the model was evaluated and verified through the decision analysis (DCA) curve. Finally, a forest plot was used for relevant subgroup analysis.

Results

Modified Poisson regression analysis revealed that the TIR was a risk factor for postoperative infection in T2DM patients, and when the TIR was <70%, the risk of postoperative infection increased by 52.2% (P <0.05). LASSO regression and Boruta algorithm screening variables revealed that the TIR, lymphocytes, neutrophils, total serum cholesterol, superoxide dismutase and type of incision were predictive factors for postoperative infection in patients with T2DM (P<0.05). The calibration curve confirmed that the model predictions were consistent with reality, and the decision curve confirmed that the model had better clinical benefits. Finally, the results of the subgroup analysis revealed that in each subgroup, the risk of postoperative infection was greater when the TIR was <70% than when the TIR was ≥70%, and there was no interaction between subgroups.

Conclusion

The TIR is related to postoperative infection and can be used as a new indicator to predict the risk of postoperative infection in patients with type 2 diabetes mellitus.

Soy Isoflavones Protects Against Stroke by Inhibiting Keap1/NQO1/Nrf2/HO-1 Signaling Pathway: Network Pharmacology Analysis Combined with the Experimental Validation

Objectives: Ischemic stroke is a severe neurological disorder with high morbidity, mortality, and disability rates, posing a substantial burden on patients, families, and healthcare systems. Soy isoflavone (SI), a naturally occurring phytoestrogen, has demonstrated promising neuroprotective effects. This study aimed to evaluate the anti-stroke efficacy of SI and elucidate its underlying mechanisms through integrated phytochemical profiling, network pharmacology, and both in vitro and in vivo experimental validation. Methods: Active constituents of SI were extracted via reflux and identified using liquid chromatography-mass spectrometry (LC-MS). Network pharmacology was employed to predict therapeutic targets and signaling pathways. The neuroprotective effects of SI were first assessed in PC12 cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. For in vivo evaluation, transient cerebral ischemia-reperfusion injury was induced using the bilateral common carotid artery occlusion (BCCAO) model in adult male ICR rats (27.3 ± 1.8 g; 6-8 weeks old), obtained from the Shanghai Experimental Animal Center, Chinese Academy of Sciences. Forty-eight rats were randomly assigned into four groups (n = 12): sham, model (BCCAO), SI-treated (100 mg/kg, oral gavage for 5 days), and edaravone (EDA)-treated (10 mg/kg, i.p., positive control). All procedures were approved by the Institutional Animal Care and Use Committee of Changchun Normal University (Approval No. 2024003, 13 March 2024) and conducted in accordance with the NIH guidelines and ARRIVE 2.0 reporting standards. Results: In vitro, SI significantly enhanced PC12 cell viability from 57.23 ± 2.88% to 80.76 ± 4.43% following OGD/R. It also reduced intracellular Ca2+ by 58.42%, lactate dehydrogenase (LDH) release by 37.67%, caspase-3 activity by 55.05%, and reactive oxygen species (ROS) levels by 74.13% (p < 0.05). A flow cytometry analysis revealed that OGD/R increased the apoptosis rate from 5.34% (control) to 30.85% (model group), which was significantly attenuated by SI treatment, especially in the 560 µg/mL group (20.00%), followed by the 140 and 280 µg/mL groups. In vivo, SI improved neurological scores from 8.3 ± 1.09 to 6.8 ± 1.68, reduced cerebral infarction volume by 18.49%, and alleviated brain edema by 10.42% (p < 0.05). SI also decreased malondialdehyde (MDA) and LDH levels by 31.15% and 39.46%, respectively, while increasing the activity of antioxidant enzymes: superoxide dismutase (SOD) by 11.70%, catalase (CAT) by 26.09%, and glutathione peroxidase (GSH-px) by 27.55% (p < 0.01). Scratch assay results showed that SI restored the impaired migratory ability of the OGD/R-treated PC12 cells, further supporting its role in cellular repair. A Western blot analysis demonstrated the upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase 1 (NQO1) and the downregulation of Kelch-like, ECH-associated protein 1 (Keap1) in the cerebral ischemia-reperfusion model. Conclusions: These findings indicate that soy isoflavone confers significant neuroprotective effects against cerebral ischemia-reperfusion injury by enhancing endogenous antioxidant defense mechanisms, reducing oxidative stress, inhibiting apoptosis, and promoting cell migration. The protective effects are likely mediated through the activation of the Nrf2/Keap1 signaling pathway, supporting the therapeutic potential of SI in ischemic stroke treatment.

A systematic review and meta-analysis show a decreasing prevalence of post-stroke infections

BACKGROUND

Infection is a common complication in the acute phase after stroke; a systematic review in 2011 reported a post-stroke infection prevalence of 30%. Despite the plethora of primary data on post-stroke infections in recent times, a systematic review that synthesizes the data to provide comprehensive information to guide preventive, control, and management efforts is yet to be undertaken. This systematic review, therefore, aimed at bridging this gap by describing the epidemiology of post-stroke infections including the global prevalence and the associated mortality rates.

METHODOLOGY

A comprehensive search was conducted in PubMed, SCOPUS, and Web of Science resulting in 2210 studies, of which 73 studies covering 32,109,574 stoke patients were included in the systematic review. Prevalence data on defined post-stroke infections were extracted for analysis in RStudio version 4.3.3.

RESULTS

The pooled prevalence of post-stroke infections and mortality rates were 9.14% and 15.91% respectively. The prevalence of post-stroke infections was highest for pneumonia (12.4%), followed by urinary tract infection (8.31%). Geographically, the prevalence of post-stroke infections for the various continents were Europe (10.41%), Africa (10.22%), South America (8.83%), North America (8.15%), Asia (8.09%), and Australia (7.88%). Common etiological agents of post-stroke infections included multidrug-resistant organisms particularly, Carbapenem-resistant Klebsiella pneumoniae (15.4-31.8%), Methicillin-resistant Staphylococcus aureus (9.8-15.4%), and Carbapenem-resistant Acinetobacter baumannii (38.5%).

CONCLUSION

This systematic review indicates about a 3-fold decline in the global prevalence of post-stroke infections in the last decade. Pneumonia is the most common post-stroke infection. Europe and Africa have the highest prevalence of post-stroke infections.

Oxidative stress as a bridge between age and stroke: A narrative review

Stroke is the third most common cause of death globally and a leading cause of disability. The cellular and molecular changes following stroke and causes of neuronal death are not fully understood, and there are few effective treatments currently available. A rapid increase in the levels of reactive oxygen species (ROS) post stroke can overwhelm antioxidant defenses and trigger a series of pathophysiologic events including the inflammatory response, blood-brain barrier (BBB) disruption, apoptosis, and autophagy, ultimately leading to neuron degeneration and apoptosis. It is thought that beyond a certain age, the ROS accumulation resulting from stroke increases the risk of morbidity and mortality. In the present review, we summarize the role of oxidative stress (OS) as a link between aging and stroke pathogenesis. We also discuss how antioxidants can play a beneficial role in the prevention and treatment of stroke by eliminating harmful ROS, delaying aging, and alleviating damage to neurons.

Decreased serum superoxide dismutase concentration has a high value for the diagnosis of periprosthetic joint infection-a single-center, retrospective study

PURPOSE

As the most serious complication of total knee arthroplasty (TKA), periprosthetic joint infection (PJI) often leads to disastrous consequences. An accurate preoperative diagnosis plays a significant role in saving prostheses and optimizing treatment outcomes. Through this retrospective case-control study, we aimed to investigate the potential of superoxide dismutase (SOD) as a novel serum biomarker in the diagnosis of PJI.

METHODS

We conducted a retrospective review of all patients who underwent TKA and received adequate follow-ups in our hospital from June 2015 to December 2021. A total of 50 patients were enrolled in the PJI group based on the 2018 International Consensus Meeting (ICM) criteria. Besides that, we enrolled 100 patients who underwent TKA in the same period and had a good postoperative course in the control group. Patient characteristics, comorbidities, laboratory results (serum, synovial, and microbial), and intraoperative findings (purulence and histopathology) were documented and compared by univariate analysis. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity, specificity, and diagnostic performance.

RESULTS

The median serum SOD level in the PJI and control group was 135.95 ± 24.47 U/ml (IQR, 111.85-158.30 U/ml) and 173.83 ± 13.9 U/ml (IQR,162.83-183.5 U/ml) (p < 0.05), respectively. With the calculated cutoff of SOD at 149.5U/L, the area under the ROC curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were 0.919, 0.72, 0.97, 0.923, and 0.874, respectively. In subgroup analysis, the specificity of SOD in diagnosing culture-negative PJI remained extremely high (0.98). Combined diagnosis of serum SOD and C-reactive protein (CRP) made AUC increase to 0.972.

CONCLUSION

Serum SOD showed great potential in the diagnosis of PJI.