Stroke-induced immunosuppression: implications for the prevention and prediction of post-stroke infections

Bidirectional regulation of the brain-gut-microbiota axis following traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202508000-00002/figure1/v/2024-09-30T120553Z/r/image-tiff Traumatic brain injury is a prevalent disorder of the central nervous system. In addition to primary brain parenchymal damage, the enduring biological consequences of traumatic brain injury pose long-term risks for patients with traumatic brain injury; however, the underlying pathogenesis remains unclear, and effective intervention methods are lacking. Intestinal dysfunction is a significant consequence of traumatic brain injury. Being the most densely innervated peripheral tissue in the body, the gut possesses multiple pathways for the establishment of a bidirectional "brain-gut axis" with the central nervous system. The gut harbors a vast microbial community, and alterations of the gut niche contribute to the progression of traumatic brain injury and its unfavorable prognosis through neuronal, hormonal, and immune pathways. A comprehensive understanding of microbiota-mediated peripheral neuroimmunomodulation mechanisms is needed to enhance treatment strategies for traumatic brain injury and its associated complications. We comprehensively reviewed alterations in the gut microecological environment following traumatic brain injury, with a specific focus on the complex biological processes of peripheral nerves, immunity, and microbes triggered by traumatic brain injury, encompassing autonomic dysfunction, neuroendocrine disturbances, peripheral immunosuppression, increased intestinal barrier permeability, compromised responses of sensory nerves to microorganisms, and potential effector nuclei in the central nervous system influenced by gut microbiota. Additionally, we reviewed the mechanisms underlying secondary biological injury and the dynamic pathological responses that occur following injury to enhance our current understanding of how peripheral pathways impact the outcome of patients with traumatic brain injury. This review aimed to propose a conceptual model for future risk assessment of central nervous system-related diseases while elucidating novel insights into the bidirectional effects of the "brain-gut-microbiota axis."

Acute nicotine exposure attenuates neurological deficits, ischemic injury and brain inflammatory responses and restores hippocampal long-term potentiation in ischemic stroke followed by lipopolysaccharide-induced sepsis-like state

Ischemic stroke is followed by an increased susceptibility to bacterial infections, which exacerbate histological stroke outcome, neurological deficits and memory impairment due to increased neuroinflammation and neurotransmitter dysfunction. Pharmacological activation of nicotinic acetylcholine receptors was suggested to mitigate brain inflammatory responses in ischemic stroke. The functional responses associated with nicotinic acetylcholine receptor activation were unknown. In this study, male NMRI mice subjected to transient intraluminal middle cerebral artery occlusion (MCAO) were intraperitoneally exposed to vehicle treatment or Escherichia coli lipopolysaccharide (LPS; 4 mg/kg)-induced sepsis-like state 24 h post-MCAO, followed by intraperitoneal administration of vehicle or nicotine (0.5 mg/kg) 30 min later. Over 96 h, rectal temperature, neurological deficits, spontaneous locomotor activity, working memory, ischemic injury, synaptic plasticity, and brain inflammatory responses were evaluated by temperature measurement, behavioral analysis, infarct volumetry, electrophysiological recordings, and polymerase-chain reaction analysis. LPS-induced sepsis induced hypothermia, increased general and focal neurological deficits, reduced spontaneous exploration behavior, reduced working memory, and increased infarct volume post-MCAO. Additional treatment with nicotine attenuated LPS-induced hypothermia, reduced neurological deficits, restored exploration behavior, restored working memory, and reduced infarct volume. Local field potential recordings revealed that LPS-induced sepsis decreased long-term potentiation (LTP) in the dentate gyrus post-MCAO, whereas concomitant nicotine exposure restored LTP in the contralateral dentate gyrus. LPS-induced sepsis increased microglial/ macrophage Iba-1 mRNA and astrocytic GFAP mRNA levels post-MCAO, whereas add-on nicotine treatment reduced astrocytic GFAP mRNA. Taken together, these findings indicate that acute nicotine exposure enhances functional stroke recovery. Future studies will have to evaluate the effects of (1) chronic nicotine exposure, a clinically relevant vascular risk factor, and (2) the cessation of nicotine exposure, which is widely recommended post-stroke, but might have detrimental effects in the early stroke recovery phase.

Linking severe traumatic brain injury to pulmonary Infections: Translocation of intestinal bacteria mediated by nociceptor neurons

The prevalence of bacterial infections significantly increases among patients with severe traumatic brain injury (STBI), leading to a notable rise in mortality rates. While immune dysfunctions are linked to the incidence of pneumonia, our observations indicate that endogenous pathogens manifest in the lungs post-STBI due to the migration of gut commensal bacteria. This translocation involves gut-innervating nociceptor sensory neurons, which are crucial for host defense. Following STBI, the expression of transient receptor potential vanilloid 1 (TRPV1) in dorsal root ganglion (DRG) neurons significantly decreases, despite an initial brief increase. The timing of TRPV1 defects coincides with the occurrence of pulmonary infections post-STBI. This alteration in TRPV1+ neurons diminishes their ability to signal bacterial injuries, weakens defense mechanisms against intestinal bacteria, and increases susceptibility to pulmonary infections via bacterial translocation. Experimental evidence demonstrates that pulmonary infections can be successfully replicated through the chemical ablation and gene interference of TRPV1+ nociceptors, and that these infections can be mitigated by TRPV1 activation, thereby confirming the crucial role of nociceptor neurons in controlling intestinal bacterial migration. Furthermore, TRPV1+ nociceptors regulate the immune response of microfold cells by releasing calcitonin gene-related peptide (CGRP), thereby influencing the translocation of gut bacteria to the lungs. Our study elucidates how changes in nociceptive neurons post-STBI impact intestinal pathogen defense. This new understanding of endogenous risk factors within STBI pathology offers novel insights for preventing and treating pulmonary infections.

Application value of neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in predicting stress ulcer after acute cerebral hemorrhage surgery

OBJECTIVE

The Platelet-to-Lymphocyte Ratio (PLR) and Neutrophil-to-Lymphocyte Ratio (NLR) are established biomarkers that are associated with the severity, progression, and fatality of diseases. This study aimed to determine their predictive value for the occurrence of stress ulcers (SU) following surgery for acute cerebral hemorrhage.

METHODS

Retrospective data from 210 patients with acute cerebral hemorrhage hospitalized between June 2020 and March 2023 were analyzed. Patients were categorized into two groups based on the occurrence of SU post-surgery: the SU group (42 patients) and the non-SU group (168 patients). Clinical characteristics of both groups were compared, and a multivariate logistic regression was conducted to identify independent risk factors for SU. The study evaluated the predictive value of NLR and PLR, individually and in combination, for predicting SU using Receiver Operating Characteristic (ROC) curves.

RESULTS

We observed significant differences between the SU and non-SU groups in several parameters, including GCS score, absolute neutrophils, NLR, PLR, postoperative tracheotomy, and intracranial infection (P < 0.05). Our multivariate logistic regression analysis identified four independent risk factors for SU in patients undergoing surgery for acute cerebral hemorrhage: GCS score, NLR, PLR, and fasting blood glucose (P < 0.05). Furthermore, ROC analysis demonstrated that the combination of NLR and PLR exhibited the highest AUC, sensitivity, and specificity in predicting SU following surgery for acute cerebral hemorrhage (P < 0.001), with values of 0.864 (95 % CI: 0.776-0.953), 0.778 (95 % CI: 0.658-0.899), and 0.941 (95 % CI: 0.889-0.993) respectively.

CONCLUSION

This study highlighted the combined application of PLR and NLR as a significant predictor of SU in patients post-acute cerebral hemorrhage surgery.

Buyang huanwu decoction alleviates stroke-induced immunosuppression in MCAO mice by reducing splenic T cell apoptosis triggered by AIM2 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is a serious disabling and fatal disease that places a heavy burden on the world. Stroke induces a state of systemic immunosuppression that is strongly associated with an increased risk of infection and severe outcomes. Buyang Huanwu Decoction (BYHWD) is an ancient Chinese traditional formula with a good clinical and experimental basis. However, the role of BYHWD on post-stroke immunomodulation, especially immunosuppression, is unclear.

AIM OF THE STUDY

The aim of this study was to investigate the pharmacological mechanism of BYHWD to alleviate ischemic stroke by analyzing splenic T cells apoptosis triggered by the AIM2 inflammasome activation cascade.

MATERIALS AND METHODS

An ischemic stroke model in C57BL/6 J mice was constructed using the MCAO method. The mNSS test and the hanging wire test were conducted to evaluate neurological impairment in mice. Histopathological damage was visualized by Nissl staining and HE staining. The protective effects of BYHWD on the spleen were determined by splenic index and spleen HE staining. The inhibition of AIM2 inflammasome cascade by BYHWD were explored through immunofluorescence (IF), flow cytometry, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Flow cytometry was used to assess the apoptosis of splenic T cells.

RESULTS

BYHWD significantly reduced infarct size, improved neurological function scores, and alleviated histopathological damage in middle cerebral artery occlusion (MCAO) mice. At the same time, BYHWD salvaged spleen atrophy. BYHWD significantly ameliorated apoptosis of splenic T lymphocytes. Key proteins and factors in the AIM2/IL-1β/FasL/Fas axis are effectively inhibited from expression after BYHWD treatment.

CONCLUSION

It is the first study to demonstrate that BYHWD can improve stroke-induced immunosuppression by down-regulating Fas-dependent splenic T-cell apoptosis triggered by peripheral AIM2 inflammasome-driven signaling cascade.

External validation of the iScore, ASTRAL score, DRAGON score, and THRIVE score and development of a nomogram to predict outcome in patients with large vessel occlusion-acute ischemic stroke

OBJECTIVE

This study aimed to validate the iScore, ASTRAL score, DRAGON score, and THRIVE score for assessing large vessel occlusion-acute ischemic stroke (AIS-LVO) and establish a predictive model for AIS-LVO patients that has better performance to guide clinical practice.

METHODS

We retrospectively included 439 patients with AIS-LVO and collected baseline data from all of them. External validation of the iScore, ASTRAL score, DRAGON score, and THRIVE score was performed. All variables were compared between groups via univariate analysis, and the results are expressed as ORs and 95 % CIs. Independent variables with P < 0.25 were included in the multivariate logistic analysis, and statistically significant differences (P < 0.05) were identified as risk factors for prognosis in AIS-LVO patients. Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were used to evaluate the predictive value of our model.

RESULTS

Our external validation resulted in an iScore under the curve (AUC) of 0.8475, an ASTRAL AUC of 0.8324, a DRAGON AUC of 0.8196, and a THRIVE AUC of 0.8039. In our research, multivariate Cox regression revealed 8 independent predictors. We used a nomogram to visualize the results of the data analysis. The AUC for the training cohort was 0.8855 (95 % CI, 0.8487-0.9222), and that in the validation cohort was 0.8992 (95 % CI, 0.8496-0. 9488).

CONCLUSIONS

In this study, we verified that the above scores have excellent efficacy in predicting the prognosis of AIS-LVO patients. The nomogram we developed was able to predict the prognosis of AIS-LVO more accurately and may contribute to personalized clinical decision-making and treatment for future clinical work.

Association Between Blood-Brain Barrier Disruption and Stroke-Associated Pneumonia in Acute Ischemic Stroke Patients After Endovascular Therapy: A Retrospective Cohort Study

Background

Stroke, particularly due to large vessel occlusion (LVO), is a major cause of mortality and disability globally. Endovascular therapy (ET) significantly improves outcomes for acute ischemic stroke (AIS) patients, but complications such as stroke-associated pneumonia (SAP) increase mortality and healthcare costs. This study investigates the association between blood-brain barrier (BBB) disruption and the increased risk of SAP and explores the relationship between BBB disruption and medium-term functional outcomes.

Methods

The retrospective cohort study was performed on AIS patients enrolled between January 2019 to February 2023 who underwent ET. Patients were divided into two groups: BBB disruption and without BBB disruption. Multiple logistic regression model was conducted to measure the association between BBB disruption and SAP. Mediation analysis was used to estimate the potential mediation effects on the associations of BBB disruption with SAP. A restricted cubic spline (RCS) regression model was used to further outline the connection between the highest CT value of hyperattenuated lesions areas and the risk of SAP.

Results

The study included 254 patients who underwent endovascular therapy, with 155 patients in the BBB disruption group (exposure) and 99 patients in the without BBB disruption group (control). Multiple logistic regression analysis revealed a significantly increased risk of SAP in patients with BBB disruption (OR = 2.337, 95% CI: 1.118-4.990, p = 0.025). Furthermore, mediation analysis suggested that this association may be partly due to malignant cerebral oedema and haemorrhagic transformation. The study found an inverse L-shaped dose-response relationship between the maximum CT values of BBB disruption areas and the incidence of SAP. SAP partially mediated the association between BBB disruption and 3-month poor functional outcome.

Conclusion

BBB disruption are a potential risk factor for SAP. BBB disruption may affect short- and medium-term prognosis of patients after ET in part through SAP.

IL-33 in Ischemic Stroke: Brain vs. Periphery

Cerebrovascular disease is the second-leading cause of death and disability worldwide, with stroke being the most common cause. In ischemic stroke, several processes combine to produce immunosuppression, leaving the post-stroke body susceptible to infection, which in turn affects neuroinflammation. Interleukin-33 (IL-33), a member of the interleukin-1 family (IL-1), functions as a modulator of immune responses and inflammation, playing a crucial role in the establishment of immunologic responses. IL-33 has been shown to have a protective effect on brain injury and represents a potential target by modulating inflammatory cytokines and stimulating immune regulatory cells. With an emphasis on preclinical and clinical studies, this review covers the impact of IL-33 on immune system mechanisms following ischemic stroke.

The Aging Immune System: A Critical Attack on Ischemic Stroke

Ischemic stroke caused by cerebrovascular embolism is an age-related disease with high rates of disability and mortality. Although the mechanisms of immune and inflammatory development after stroke have been of great interest, most studies have neglected the critical and unavoidable factor of age. As the global aging trend intensifies, the number of stroke patients is constantly increasing, emphasizing the urgency of finding effective measures to address the needs of elderly stroke patients. The concept of "immunosenescence" appears to explain the worse stroke outcomes in older individuals. Immune remodeling due to aging involves dynamic changes at all levels of the immune system, and the overall consequences of central (brain-resident) and peripheral (non-brain-resident) immune cells in stroke vary according to the age of the individual. Lastly, the review outlines recent strategies aimed at immunosenescence to improve stroke prognosis.

Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker of Functional Outcome in Patients With Intracerebral Hemorrhage (ICH) and Its Comparison With ICH Score: A Hospital-Based Study

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) signifies systemic inflammation, which may correlate with worse outcomes in intracerebral hemorrhage (ICH) patients. This study explored NLR as a prognostic marker of functional outcomes in ICH and compared it with the ICH score.

METHODS

This cross-sectional study was conducted at a tertiary-care hospital in India. Blood was collected from patients with ICH to calculate NLR. Functional outcomes were evaluated using the modified Rankin Scale (mRS) at discharge and 90 days follow-up.

RESULTS

The area under receiver operating characteristic curve (AUROC) for NLR predicting poor mRS scores (3-6) at discharge was 0.695 (p = 0.109), and at follow-up, it was 0.729 (p < 0.001) with a cut-off of ≥7.2, sensitivity 68%, and specificity 72%. The AUROC for ICH score was 0.846 (p = 0.003) at discharge and 0.845 (p < 0.001) at follow-up. DeLong's test indicated the ICH score had significantly better predictive performance than NLR at follow-up (p = 0.018).

CONCLUSIONS

NLR is a potential prognostic marker for ICH outcomes, showing significant predictive value at 90 days follow-up. However, the ICH score remains a more reliable predictor. Integrating NLR into the ICH score may enhance its prognostic accuracy, but further validation in multicentric studies is needed.

Impact of peripheral lymphocyte subsets on prognosis for patients after acute ischemic stroke: A potential disease prediction model approach

AIMS

To investigate the relationship between peripheral blood lymphocyte subsets and prognosis in patients with acute ischemic stroke (AIS).

METHODS

We enrolled 294 patients with AIS and collected peripheral blood samples for analysis of lymphocyte subsets. Prognosis was assessed at 3 months using the modified Rankin Scale (mRS). Association between lymphocyte count and poor outcomes (mRS score >2) was assessed using logistic regression. Individualized prediction models were developed to predict poor outcomes.

RESULTS

Patients in the mRS score ≤2 group had higher T-cell percentage (odds ratio [OR] = 0.947; 95% confidence interval [CI]: 0.899-0.998; p = 0.040), CD3+ T-cell count (OR = 0.999; 95% CI: 0.998-1.000; p = 0.018), and CD4+ T-cell count (OR = 0.998; 95% CI: 0.997-1.000; p = 0.030) than those in the mRS score >2 group 1-3 days after stroke. The prediction model for poor prognosis based on the CD4+ T-cell count showed good discrimination (area under the curve of 0.844), calibration (p > 0.05), and clinical utility.

CONCLUSION

Lower T cell percentage, CD3+, and CD4+ T-cell counts 1-3 days after stroke were independently associated with increased risk of poor prognosis. Individualized predictive model of poor prognosis based on CD4+ T-cell count have good accuracy and may predict disease prognosis.

Association between fibrinogen levels and stroke-associated pneumonia in acute ischemic stroke patients

PURPOSE

Prior research had indicated a relationship between fibrinogen and stroke-associated pneumonia (SAP), yet the nature of this relationship had not been thoroughly investigated. Therefore, this study was designed to elucidate the prognostic value of fibrinogen levels in forecasting the occurrence of SAP among patients with acute ischemic stroke (AIS).

PATIENTS AND METHODS

In this retrospective cross-sectional analysis, we included 1092 patients who had experienced AIS and were admitted to our facility within 72 h of the onset of their symptoms. Based on the SAP diagnostic criteria, patients were classified into two groups: SAP and non-SAP. The correlation between serum fibrinogen concentration and SAP was examined using univariate analysis. Curve fitting and multivariable logistic regression model were utilized for statistical evaluation.

RESULTS

Out of the ischemic stroke patients included in the study, SAP was identified in 112 (10.26%) patients. A direct correlation was observed between fibrinogen levels and the incidence of SAP. An increase in fibrinogen levels corresponded with a heightened incidence of SAP. Multivariable logistic regression revealed a significant positive association between fibrinogen levels and SAP incidence (OR = 1.53, 95% confidence interval [CI]: 1.18, 1.99)).

CONCLUSION

A linear relationship between serum fibrinogen levels and the incidence of SAP in ischemic stroke patients was shown. The serum fibrinogen levels were positively and linearly correlated to SAP risk.

Association of follow-up neutrophil-to-lymphocyte ratio and systemic inflammation response index with stroke-associated pneumonia and functional outcomes in cerebral hemorrhage patients: a case-controlled study

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) and systemic inflammation response index (SIRI) at admission are independent diagnostic biomarkers in stroke-associated pneumonia (SAP). Our study aimed to investigate the association between NLR, SIRI, specifically follow-up NLR and SIRI, and SAP, as well as their relationship with functional outcomes.

PATIENTS AND METHODS

We retrospectively included 451 consecutive intracerebral hemorrhage patients from May 2017 to May 2019. We conducted univariate and multivariable analyses to identify the factors independently associated with SAP and poor functional outcomes.

RESULTS

Compared to 127 (28.16%) patients diagnosed with SAP, those without SAP had both lower baseline and follow-up NLR and SIRI values ( P <0.001). After adjustments, we found that baseline NLR [OR, 1.039 (95% CI, 1.003-1.077); P =0.036] and follow-up NLR [OR, 1.054 (95% CI, 1.011-1.098); P =0.012] were independently associated with SAP. The follow-up NLR was also associated with a higher mRS [OR, 1.124 (95% CI, 1.025-1.233); P =0.013] and lower ADL-MBI score [OR, 1.167 (95% CI, 1.057-1.289); P =0.002] at discharge. Multivariable analysis indicated that advanced age and nasogastric tube feeding were independently associated with SAP ( P <0.05). We constructed a dynamic nomogram to identify SAP risk. Further subgroup analysis revealed that baseline NLR [OR, 1.062 (95% CI, 1.007-1.120); P =0.026] is independently associated with SAP in the nasogastric feeding group, while follow-up NLR [OR, 1.080 (95% CI, 1.024-1.139); P =0.005] was associated with the occurrence of SAP in non-nasogastric feeding patients.

CONCLUSIONS

We found elevated baseline and follow-up NLR values were associated with SAP occurrence, and increasing follow-up NLR indicated poor functional outcomes. Inflammatory markers at different stages may offer individualized guidance for patients receiving various treatments.

Thick Liquids and Clinical Outcomes in Hospitalized Patients With Alzheimer Disease and Related Dementias and Dysphagia

Importance

Oropharyngeal dysphagia is common in hospitalized patients with Alzheimer disease and related dementias (ADRD). Although the use of thick liquids in patients with dysphagia has been shown to reduce aspiration on direct visualization, there is no clear evidence that this practice translates into improved clinical outcomes.

Objectives

To determine whether a diet of thick liquids compared with thin liquids is associated with improved outcomes in hospitalized patients with ADRD and dysphagia.

Design, Setting, and Participants

This cohort study included adults aged 65 years and older with ADRD who were admitted to the medicine service across 11 diverse hospitals in New York between January 1, 2017, and September 20, 2022, with clinical suspicion of dysphagia during hospitalization and survival for at least 24 hours after hospital arrival. Patients were grouped according to whether at least 75% of their hospital diet consisted of a thick liquid diet or a thin liquid diet. Propensity score matching was used to balance covariates across the 2 groups for the following covariates: demographics (eg, age, sex), baseline clinical characteristics (eg, Charlson Comorbidity Index), and acute presentation (eg, respiratory diagnosis, illness severity, delirium).

Main Outcomes and Measures

Hospital outcomes included mortality (primary outcome), respiratory complications (eg, pneumonia), intubation, and hospital length of stay (LOS).

Results

Of 8916 patients with ADRD and dysphagia included in the propensity score matched analysis, the mean (SD) age was 85.7 (8.0) years and 4829 were female (54.2%). A total of 4458 patients receiving a thick liquid diet were matched with 4458 patients receiving a thin liquid diet. There was no significant difference in hospital mortality between the thick liquids and thin liquids groups (hazard ratio, 0.92; 95% CI, 0.75-1.14]; P = .46). Compared with patients receiving thin liquids, patients receiving thick liquids were less likely to be intubated (odds ratio [OR], 0.66; 95% CI, 0.54-0.80), but they were more likely to have respiratory complications (OR, 1.73; 95% CI, 1.56-1.91).

Conclusions and Relevance

This cohort study emphasizes the need for prospective studies that evaluate whether thick liquids are associated with improved clinical outcomes in hospitalized patients with ADRD and dysphagia.

Nanomaterial-Based Strategies for Attenuating T-Cell-Mediated Immunodepression in Stroke Patients: Advancing Research Perspectives

This review article discusses the potential of nanomaterials in targeted therapy and immunomodulation for stroke-induced immunosuppression. Although nanomaterials have been extensively studied in various biomedical applications, their specific use in studying and addressing immunosuppression after stroke remains limited. Stroke-induced neuroinflammation is characterized by T-cell-mediated immunodepression, which leads to increased morbidity and mortality. Key observations related to immunodepression after stroke, including lymphopenia, T-cell dysfunction, regulatory T-cell imbalance, and cytokine dysregulation, are discussed. Nanomaterials, such as liposomes, micelles, polymeric nanoparticles, and dendrimers, offer advantages in the precise delivery of drugs to T cells, enabling enhanced targeting and controlled release of immunomodulatory agents. These nanomaterials have the potential to modulate T-cell function, promote neuroregeneration, and restore immune responses, providing new avenues for stroke treatment. However, challenges related to biocompatibility, stability, scalability, and clinical translation need to be addressed. Future research efforts should focus on comprehensive studies to validate the efficacy and safety of nanomaterial-based interventions targeting T cells in stroke-induced immunosuppression. Collaborative interdisciplinary approaches are necessary to advance the field and translate these innovative strategies into clinical practice, ultimately improving stroke outcomes and patient care.

Low Prognostic Nutritional Index Predicts In-Hospital Complications and Case Fatality in Patients with Spontaneous Intracerebral Hemorrhage: A Retrospective Study

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) is associated with high case fatality and significant healthcare costs. Recent studies emphasize the critical role of nutritional status in affecting outcomes in neurological disorders. This study investigates the relationship between the Prognostic Nutrition Index (PNI) and in-hospital complications and case fatality among patients with ICH.

METHODS

A retrospective analysis was performed using data from the Changhua Christian Hospital Clinical Research Database between January 2015 and December 2022. Patients under 20 or over 100 years of age or with incomplete medical data were excluded. We utilized restricted cubic spline models, Kaplan-Meier survival analysis, and ROC analysis to assess the association between PNI and clinical outcomes. Propensity score matching analysis was performed to balance these clinical variables between groups.

RESULTS

In this study, 2402 patients with spontaneous ICH were assessed using the median PNI value of 42.77. The cohort was evenly divided between low and high PNI groups, predominantly male (59.1%), with an average age of 64 years. Patients with lower PNI scores at admission had higher in-hospital complications and increased 28- and 90-day case fatality rates.

CONCLUSIONS

Our study suggests that PNI could serve as a valuable marker for predicting medical complications and case fatality in patients with spontaneous ICH.

Impact of healthcare-associated infections within 7-days of acute stroke on health outcomes and risk of care-dependency: a multi-centre registry-based cohort study

Healthcare-associated infections (HCAIs) in patients admitted with acute conditions remain a major challenge to healthcare services. Here, we assessed the impact of HCAIs acquired within 7-days of acute stroke on indicators of care-quality outcomes and dependency. Data were prospectively collected (2014-2016) from the Sentinel Stroke National Audit Programme for 3309 patients (mean age = 76.2 yr, SD = 13.5) admitted to four UK hyperacute stroke units (HASU). Associations between variables were assessed by multivariable logistic regression (odds ratios, 95% confidence intervals), adjusted for age, sex, co-morbidities, pre-stroke disability, swallow screening, stroke type and severity. Within 7-days of admission, urinary tract infection (UTI) and pneumonia occurred in 7.6% and 11.3% of patients. Female (UTI only), older age, underlying hypertension, atrial fibrillation, previous stroke, pre-stroke disability, intracranial haemorrhage, severe stroke, and delay in swallow screening (pneumonia only) were independent risk factors of UTI and pneumonia. Compared to patients without UTI or pneumonia, those with either or both of these HCAIs were more likely to have prolonged stay (> 14-days) on HASU: 5.1 (3.8-6.8); high risk of malnutrition: 3.6 (2.9-4.5); palliative care: 4.5 (3.4-6.1); in-hospital mortality: 4.8 (3.8-6.2); disability at discharge: 7.5 (5.9-9.7); activity of daily living support: 1.6 (1.2-2.2); and discharge to care-home: 2.3 (1.6-3.3). In conclusion, HCAIs acquired within 7-days of an acute stroke led to prolonged hospitalisation, adverse health consequences and risk of care-dependency. These findings provide valuable information for timely intervention to reduce HCAIs, and minimising subsequent adverse outcomes.

Investigation of the underlying mechanism of Buyang Huanwu decoction in ischemic stroke by integrating systems pharmacology-proteomics and in vivo experiments

Buyang Huanwu Decoction (BHD) has been effective in treating ischemic stroke (IS). However, its mechanism of action remains unclear. The study intended to explore the potential mechanism of BHD against IS using systems pharmacology, proteomics, and animal experiments. The active components of BHD were identified from UPLC-Q-TOF-MS and literature mining. Systems pharmacology and proteomics were employed to investigate the underlying mechanism of BHD against IS. The AutoDock tool was used for molecular docking. A middle cerebral artery occlusion (MCAO) model rat was utilized to explore the therapeutic benefits of BHD. The rats were divided into sham, model, BHD (5, 10, 20 g/kg, ig) groups. The neurological scores, pathological section characteristics, brain infarct volumes, inflammatory cytokines, and signaling pathways were investigated in vivo experiments. The results of systems pharmacology showed that 13 active compounds and 112 common targets were screened in BHD. The docking results suggested that the active compounds in BHD had a high affinity for the key targets. In vivo experiments demonstrated that BHD exhibited neuroprotective benefits by lowering the neurological score, the volume of the cerebral infarct, the release of inflammatory cytokines, and reducing neuroinflammatory damage in MCAO rats. Furthermore, BHD decreased TNF-α and CD38 levels while increasing ATP2B2, PDE1A, CaMK4, p-PI3K, and p-AKT. Combined with systems pharmacology and proteomic studies, we confirmed that PI3K-Akt and calcium signaling pathways are the key mechanisms for BHD against IS. Furthermore, this study demonstrated the feasibility of combining proteomics with systems pharmacology to study the mechanism of herbal medicine.

Systemic-inflammatory indices and clinical outcomes in patients with anterior circulation acute ischemic stroke undergoing successful endovascular thrombectomy

Background

There is a lack of comprehensive profile assessment on complete blood count (CBC)-derived systemic-inflammatory indices, and their correlations with clinical outcome in patients with anterior circulation acute ischemic stroke (AIS) who achieved successful recanalization by endovascular thrombectomy (EVT).

Methods

Patients with anterior circulation AIS caused by large vessel occlusion (AIS-LVO) were retrospectively screened from December 2018 to December 2022. Systemic-inflammatory indices including ratios of neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte (PLR), and platelet-to-neutrophil (PNR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and aggregate inflammation systemic index (AISI) on admission and the first day post-EVT were calculated. Their correlations with symptomatic intracranial hemorrhage (sICH) and unfavorable 90-day functional outcome (modified Rankin Scale score of 3-6) were analyzed.

Results

A total of 482 patients [65 (IQR, 56-72) years; 33 % female] were enrolled, of which 231 (47.9 %) had unfavorable 90-day outcome and 50 (10.4 %) developed sICH. Day 1 neutrophil and monocyte counts, NLR, MLR, PLR, SII, SIRI, and AISI were increased, while lymphocyte and PNR were decreased compared to their admission levels. In multivariate analyses, neutrophil count, NLR, SII, and AISI on day 1 were independently associated with 90-day functional outcome. Moreover, day 1 neutrophil count, NLR, MLR, PLR, PNR, SII, and SIRI were independently linked to the occurrence of sICH. No admission variables were identified as independent risk factors for patient outcomes.

Conclusion

CBC-derived systemic-inflammatory indices measured on the first day after successful EVT are predictive of 90-day functional outcome and the sICH occurrence in patients with anterior circulation AIS-LVO.

Aquaporins alteration revealed kidney damages in cerebral ischemia/reperfusion rats

Background

Restoration of blood supply is a desired goal for the treatment of acute ischemic stroke. However, the restoration often leads to cerebral ischemia-reperfusion injury (CIR/I), which greatly increases the risk of non-neural organ damage. In particular, the acute kidney injury might be one of the most common complications.

Aims

The study aimed to understand the damage occurred and the potential molecular mechanisms.

Methods

The study was explored on the CIR/I rats generated by performing middle cerebral artery occlusion/reperfusion (MCAO/Reperfusion). The rats were evaluated with injury on the brains, followed by the non-neural organs including kidneys, livers, colons and stomachs. They were examined further with histopathological changes, and gene expression alterations by using RT-qPCR of ten aquaporins (Aqps) subtypes including Aqp1～Aqp9 and Aqp11. Furthermore, the Aqps expression profiles were constructed for each organ and analyzed by performing Principle Component Analysis. In addition, immunohistochemistry was explored to look at the protein expression of Aqp1, Aqp2, Aqp3 and Aqp4 in the rat kidneys.

Results

There was a prominent down-regulation profile in the MCAO/Reperfusion rat kidneys. The protein expression of Aqp1, Aqp2, Aqp3 and Aqp4 was decreased in the kidneys of the MCAO/Reperfusion rats. We suggested that the kidney was in the highest risk to be damaged following the CIR/I. Down-regulation of Aqp2, Aqp3 and Aqp4 was involved in the acute kidney injury induced by the CIR/I.

Evidence of varicella zoster virus (VZV) reactivation in children with arterial ischemic stroke: Results of the VIPS II Study

Background

Varicella zoster virus (VZV) has been associated with focal cerebral arteriopathy (FCA) and arterial ischemic stroke (AIS) in childhood. The Vascular effects of Infection in Pediatric Stroke (VIPS) II study aimed to examine this relationship in the modern era when most children in North America and Australia receive VZV vaccination with live, attenuated virus.

Methods

This 22-center prospective cohort study enrolled 205 children (28 days-18 years) with AIS (2017-2022), collected baseline [hyperacute (≤72 hours; n=194) and acute (4-6 days; n=181)] and convalescent (1-6 weeks; n=74) serum samples. Sites enrolled 95 stroke-free controls with single serum samples. A virology research laboratory measured VZV IgM and IgG titers by an in-house enzyme-linked immunosorbent assay (ELISA). Baseline IgG seropositivity indicated prior exposure (vaccination/infection) and elevated IgM titers indicated recent reactivation.

Results

Median (IQR) age was 11.6 (5.5-15.6) years for cases and 11.8 (6.8-15.3) years for controls. Baseline serologies indicated prior VZV exposure in 198 cases (97%) and all controls. Parents of cases reported VZV vaccination in 160 (78%) and remote chicken pox in three (1.4%). Twenty cases (9.8%) and three controls (3.1%) had serologic evidence of recent VZV reactivation (p=0.06); all had remote VZV exposure (vaccination in 19 cases and all controls) and all were asymptomatic. Recent VZV reactivation was seen in similar proportions in arteriopathic, cardioembolic, and idiopathic stroke. Of 32 cases of FCA, 4 (12.5%) had recent VZV reactivation, versus no cases of arterial dissection (n=10) or moyamoya (n=16).

Conclusions

Serologic evidence of recent VZV reactivation (≈1-6 weeks prior to stroke) was present in one in 10 cases of childhood AIS, including those without arteriopathy. Clinically silent VZV reactivation may be a childhood stroke trigger despite widespread vaccination. These cases could represent waning immunity with reactivation of either vaccine virus or wild-type virus after an unrecognized secondary VZV infection.

Exposure to Environmental Toxins: Potential Implications for Stroke Risk via the Gut- and Lung-Brain Axis

Recent evidence indicates that exposure to environmental toxins, both short-term and long-term, can increase the risk of developing neurological disorders, including neurodegenerative diseases (i.e., Alzheimer's disease and other dementias) and acute brain injury (i.e., stroke). For stroke, the latest systematic analysis revealed that exposure to ambient particulate matter is the second most frequent stroke risk after high blood pressure. However, preclinical and clinical stroke investigations on the deleterious consequences of environmental pollutants are scarce. This review examines recent evidence of how environmental toxins, absorbed along the digestive tract or inhaled through the lungs, affect the host cellular response. We particularly address the consequences of environmental toxins on the immune response and the microbiome at the gut and lung barrier sites. Additionally, this review highlights findings showing the potential contribution of environmental toxins to an increased risk of stroke. A better understanding of the biological mechanisms underlying exposure to environmental toxins has the potential to mitigate stroke risk and other neurological disorders.

Ischemic stroke outcome after promoting CD4+CD25+ Treg cell migration through CCR4 overexpression in a tMCAO animal model

The importance of neuroinflammation during the ischemic stroke has been extensively studied. The role of CD4+CD25+ regulatory T (Treg) cells during the recovery phase have shown infarct size reduction and functional improvement, possibly through the mitigation of inflammatory immune responses. We aimed to investigate the molecular factors involved in microglia-Treg cell communication that result in Treg trafficking. First, we observed the migration patterns of CD8+ (cytotoxic) T cells and Treg cells and then searched for chemokines released by activated microglia in an oxygen-glucose deprivation (OGD) model. The transwell migration assay showed increased migration into OGD media for both cell types, in agreement with the increase in chemokines involved in immune cell trafficking from the mouse chemokine profiling array. MSCV retrovirus was transduced to overexpress CCR4 in Treg cells. CCR4-overexpressed Treg cells were injected into the mouse transient middle cerebral artery occlusion (tMCAO) model to evaluate the therapeutic potential via the tetrazolium chloride (TTC) assay and behavioral tests. A general improvement in the prognosis of animals after tMCAO was observed. Our results suggest the increased mobility of CCR4-overexpressed Treg cells in response to microglia-derived chemokines in vitro and the therapeutic potential of Treg cells with increased mobility in cellular therapy.

Pathophysiology of acute lung injury in patients with acute brain injury: the triple-hit hypothesis

It has been convincingly demonstrated in recent years that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after ABI. The pathophysiology of the bidirectional brain-lung interactions is multifactorial and involves inflammatory cascades, immune suppression, and dysfunction of the autonomic system. Indeed, the systemic effects of inflammatory mediators in patients with ABI create a systemic inflammatory environment ("first hit") that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery, and infections ("second hit"). Moreover, accumulating evidence supports the knowledge that gut microbiota constitutes a critical superorganism and an organ on its own, potentially modifying various physiological functions of the host. Furthermore, experimental and clinical data suggest the existence of a communication network among the brain, gastrointestinal tract, and its microbiome, which appears to regulate immune responses, gastrointestinal function, brain function, behavior, and stress responses, also named the "gut-microbiome-brain axis." Additionally, recent research evidence has highlighted a crucial interplay between the intestinal microbiota and the lungs, referred to as the "gut-lung axis," in which alterations during critical illness could result in bacterial translocation, sustained inflammation, lung injury, and pulmonary fibrosis. In the present work, we aimed to further elucidate the pathophysiology of acute lung injury (ALI) in patients with ABI by attempting to develop the "double-hit" theory, proposing the "triple-hit" hypothesis, focused on the influence of the gut-lung axis on the lung. Particularly, we propose, in addition to sympathetic hyperactivity, blast theory, and double-hit theory, that dysbiosis and intestinal dysfunction in the context of ABI alter the gut-lung axis, resulting in the development or further aggravation of existing ALI, which constitutes the "third hit."

Development and validation of a predictive model for stroke associated pneumonia in patients after thrombectomy for acute ischemic stroke

Objective

This study aims to identify the risk factors associated with stroke-associated pneumonia (SAP) in patients who have undergone thrombectomy for acute ischemic stroke and to develop a nomogram chart model for predicting the occurrence of pneumonia.

Methods

Consecutive patients who underwent thrombectomy for acute ischemic stroke were enrolled from three hospitals at Taizhou Enze Medical Center. They were randomly divided into a training group and a validation group in a 7:3 ratio. The training group data was used to screen for effective predictive factors using LASSO regression. Multiple logistic regression was then conducted to determine the predictive factors and construct a nomogram chart. The model was evaluated using the validation group, analyzing its discrimination, calibration, and clinical decision curve. Finally, the newly constructed model was compared with the AIS-APS, A2DS2, ISAN, and PANTHERIS scores for acute ischemic stroke-associated pneumonia.

Results

Out of 913 patients who underwent thrombectomy, 762 were included for analysis, consisting of 473 males and 289 females. The incidence rate of SAP was 45.8%. The new predictive model was constructed based on three main influencing factors: NIHSS ≥16, postoperative LMR, and difficulty swallowing. The model demonstrated good discrimination and calibration. When applying the nomogram chart to threshold probabilities between 7 and 90%, net returns were increased. Furthermore, the AUC was higher compared to other scoring systems.

Conclusion

The constructed nomogram chart in this study outperformed the AIS-APS, A2DS2 score, ISAN score, and PANTHERIS score in predicting the risk of stroke-associated pneumonia in patients with acute ischemic stroke after thrombectomy. It can be utilized for clinical risk prediction of stroke-associated pneumonia in patients after thrombectomy for acute ischemic stroke.

The Impact of Undernutrition Risk on Rehabilitation Outcomes in Ischemic Stroke Survivors: A Hospital-Based Study

Patients experiencing a cerebrovascular event are vulnerable to declining nutritional status, hindering rehabilitation. This study aims to analyze the association between malnutrition risk and hospital rehabilitation indicators in ischemic stroke survivors (ISS). This analytical study examined medical records of 160 adult patients (69.3 ± 13 years). Undernutrition risk (UR; independent variable) and rehabilitation indicators (dependent variables) like hospital stay, clinical outcome, functionality, stroke severity, food intake, mobility (bedridden), mechanical ventilation, and enteral nutrition were assessed. Data were dichotomized, and the chi-square test identified associations (p ≤ 0.05), followed by Poisson regression for prevalence ratios. Patients at UR had 2-fold higher risk of death (95% confidence interval [CI], 0.99-4.79), 1.8-fold higher risk of high stroke severity (95% CI, 1.06-3.11), 76% higher chance of being bedridden (95% CI, 1.28-2.44), and 3-fold higher risk of mechanical ventilation (95% CI, 1.20-9.52). UR in hospitalized ISS is associated with deteriorating rehabilitation indicators, including mobility, decreased food intake, mechanical ventilation use, and neurological deficit, indicating an increased mortality risk post-stroke.

Autonomic dysfunction and treatment strategies in intracerebral hemorrhage

AIMS

Autonomic dysfunction with central autonomic network (CAN) damage occurs frequently after intracerebral hemorrhage (ICH) and contributes to a series of adverse outcomes. This review aims to provide insight and convenience for future clinical practice and research on autonomic dysfunction in ICH patients.

DISCUSSION

We summarize the autonomic dysfunction in ICH from the aspects of potential mechanisms, clinical significance, assessment, and treatment strategies. The CAN structures mainly include insular cortex, anterior cingulate cortex, amygdala, hypothalamus, nucleus of the solitary tract, ventrolateral medulla, dorsal motor nucleus of the vagus, nucleus ambiguus, parabrachial nucleus, and periaqueductal gray. Autonomic dysfunction after ICH is closely associated with neurological functional outcomes, cardiac complications, blood pressure fluctuation, immunosuppression and infection, thermoregulatory dysfunction, hyperglycemia, digestive dysfunction, and urogenital disturbances. Heart rate variability, baroreflex sensitivity, skin sympathetic nerve activity, sympathetic skin response, and plasma catecholamine concentration can be used to assess the autonomic functional activities after ICH. Risk stratification of patients according to autonomic functional activities, and development of intervention approaches based on the restoration of sympathetic-parasympathetic balance, would potentially improve clinical outcomes in ICH patients.

CONCLUSION

The review systematically summarizes the evidence of autonomic dysfunction and its association with clinical outcomes in ICH patients, proposing that targeting autonomic dysfunction could be potentially investigated to improve the clinical outcomes.

Risk factors for dysphagia in patients with acute and chronic ischemic stroke: A retrospective cohort study

Background

Dysphagia is a common and clinically significant complication of ischemic stroke. The prevalence and risk factors for dysphagia may vary at different stages following an ischemic stroke.

Methods

This study included patients with acute and chronic ischemic stroke who were treated at the Department of Rehabilitation, First Affiliated Hospital, Zhejiang University School of Medicine from 2019 to 2022. Various demographic, clinical, and laboratory parameters were collected, and statistical analyses were performed to investigate their association with dysphagia.

Results

Among the 399 ischemic stroke patients included in the study, 165 (41.4 %) experienced dysphagia, with 72 (38.7 %) in the acute phase and 93 (43.7 %) in the chronic phase. Univariate analysis revealed significant associations (p < 0.05) between dysphagia and factors such as pulmonary infection, aphasia, NIHSS score, ADL score, NLR score, lower extremity Brunnstrom's stages, and sit-to-stand balance. Multiple logistic regression analysis, after adjusting for confounding factors, identified the ADL score as an independent predictor of dysphagia. These findings were consistent across three time-windows: the acute phase, the chronic phase, and 180 days after stroke onset. Additionally, the lymphocyte count and pulmonary infection were identified as potential independent indicators.

Conclusions

This study investigated the prevalence and risk factors for dysphagia in ischemic stroke patients at different time-windows. A low ADL score (<40) may serve as a valuable and reliable predictor for poststroke dysphagia in clinical settings.

Infection, Inflammation, and Poststroke Cognitive Impairment

BACKGROUND

Infection and inflammation are dementia risk factors in population-based cohorts; however, studies in stroke are scarce. We determined the prevalence of infection after stroke and routinely measured inflammatory biomarkers during hospitalization and their associations with acute and 6-month cognitive impairment.

METHODS AND RESULTS

A prospective stroke cohort completed the Oxford Cognitive Screen at ≤2 weeks and 6 months after stroke. Infection, inflammatory markers (C-reactive protein, white cell count, and neutrophil/lymphocyte ratio), and systemic inflammatory response syndrome were ascertained throughout admission with electronic patient records supplemented by hand searches. Associations with acute and 6-month global and domain-specific cognitive impairment were analyzed using multivariable regression, adjusting for demographic/vascular factors and stroke severity. Among 255 patients (mean age, 73.9 [SD, 12.6] years; 46.3% women; mean education, 12.6 [SD, 3.7] years; median National Institutes of Health Stroke Scale score 5 [range, minimum-maximum, 0-30]), infection was present in 90 patients (35.3%) at mean 4.4 (SD, 6.9) days after stroke, consisting predominantly of pneumonia (47/90; 52%) and urinary tract infection (39/90; 43%). Admission white cell count was elevated in 25.1% (n=64; mean, 9.5×109/L [SD, 3.2×109/L]), C-reactive protein in 41.2% (n=105; mean, 27.5 [SD, 50.9 mg/L]), neutrophil/lymphocyte ratio in 55.7% (n=97; mean, 5.5 [SD, 4.5]), and systemic inflammatory response syndrome in 26.6% (n=53 [45.2%] positive during hospitalization). Infection was associated with acute and 6-month poststroke cognitive impairment (P<0.05adj) with stronger associations acutely for severe infection (infection+systemic inflammatory response syndrome; P=0.03adj). Acute language, executive function and attention domain impairments, and 6-month number processing impairment were associated with infection (P<0.05adj). No significant relationships were found for any biomarker and cognitive impairment.

CONCLUSIONS

Infection and elevations in routinely measured inflammatory biomarkers are common following stroke; however, only infection is associated with poststroke cognitive impairment, suggesting that increases in these biomarkers may be nonspecific. Infection may present a tractable target for reducing poststroke cognitive impairment.

Monocyte to high-density lipoprotein cholesterol ratio is associated with cerebral small vessel diseases

BACKGROUND

Inflammation is a major pathological mechanism underlying cerebrovascular disease. Recently, a new inflammatory marker based on the ratio between monocyte count and high-density lipoprotein (HDL) cholesterol has been proposed. In this study, we evaluated the relationship between monocyte-to-HDL cholesterol ratio (MHR) and cerebral small vessel disease (cSVD) lesions in health check-up participants.

METHODS

This study was a retrospective cross-sectional study based on a registry that prospectively collected health check-up participants between 2006 and 2013. Three cSVD subtypes were measured on brain magnetic resonance imaging. White matter hyperintensity (WMH) volume, and lacunes and cerebral microbleeds (CMBs) were quantitatively and qualitatively measured, respectively. The MHR was calculated according to the following formula: MHR = monocyte counts (× 103/μL) / HDL cholesterol (mmol/L).

RESULTS

In total, 3,144 participants were evaluated (mean age: 56 years, male sex: 53.9%). In multivariable analyzes adjusting for confounders, MHR was significantly associated with WMH volume [β = 0.099, 95% confidence interval (CI) = 0.025 to 0.174], lacune [adjusted odds ratio (aOR) = 1.43, 95% CI = 1.07-1.91], and CMB (aOR = 1.51, 95% CI = 1.03-2.19). In addition, MHR showed a positive quantitative relationship with cSVD burden across all three subtypes: WMH (P < 0.001), lacunes (P < 0.001), and CMBs (P < 0.001).

CONCLUSIONS

High MHR was closely associated with cSVD in health check-up participants. Because these associations appear across all cSVD subtypes, inflammation appears to be a major pathological mechanism in the development of various cSVDs.

[Algorithms for the diagnosis and treatment of cognitive impairment and dysphagia in stroke patients]

Stroke is a socially significant neurological disease, the second most common cause of disability and mortality. A wide range of neurological problems that occur after stroke: cognitive, motor, speech, and language disfunction, neuropsychiatric, swallowing disorders and others, complicate rehabilitation, impair social and everyday adaptation, and reduce the quality of life of patients and their caregivers. Cognitive impairment (CI) is one of the most significant and common complications of stroke. Stroke increases the risk of their development by 5-8 times. Dysphagia is also a common symptom of stroke, the cause of aspiration complications (pneumonia), and nutritional imbalance. It increases the possibility of developing CI and dementia, and contributes to an increase in mortality. Older adults with CI are at a higher risk of developing dysphagia, therefore the early symptoms of dysphagia (presbyphagia) should be diagnosed. In recent years, the connection between CI and dysphagia has been actively studied. It is extremely important to identify CI and swallowing disorders as early as possible in patients both before and at all stages after stroke; as well as to develop combined multidisciplinary protocols for the rehabilitation of patients with these disorders with pharmacological support for the process.

Nomogram for Risk of Secondary Venous Thromboembolism in Stroke Patients: A Study Based on the MIMIC-IV Database

This study aims to identify risk factors for secondary venous thromboembolism (VTE) in stroke patients and establish a nomogram, an accurate predictor of probability of VTE occurrence during hospitalization in stroke patients. Medical Information Mart for Intensive Care IV (MIMIC-IV) database of critical care medicine was utilized to retrieve information of stroke patients admitted to the hospital between 2008 and 2019. Patients were randomly allocated into train set and test set at 7:3. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for secondary VTE in stroke patients. A predictive nomogram model was constructed, and the predictive ability of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). This study included 266 stroke patients, with 26 patients suffering secondary VTE after stroke. A nomogram for predicting risk of secondary VTE in stroke patients was built according to pulmonary infection, partial thromboplastin time (PTT), log-formed D-dimer, and mean corpuscular hemoglobin (MCH). Area under the curve (AUC) of the predictive model nomogram was 0.880 and 0.878 in the train and test sets, respectively. The calibration curve was near the diagonal, and DCA curve presented positive net benefit. This indicates the model's good predictive performance and clinical utility. The nomogram effectively predicts the risk probability of secondary VTE in stroke patients, aiding clinicians in early identification and personalized treatment of stroke patients at risk of developing secondary VTE.

Disulfidptosis and its Role in Peripheral Blood Immune Cells after a Stroke: A New Frontier in Stroke Pathogenesis

BACKGROUND

Stroke-Induced Immunodepression (SIID) is characterized by apoptosis in blood immune populations, such as T cells, B cells, NK cells, and monocytes, leading to the clinical presentation of lymphopenia. Disulfidptosis is a novel form of programmed cell death characterized by accumulating disulfide bonds in the cytoplasm, resulting in cellular dysfunction and eventual cell death.

OBJECTIVE

In this study, we investigated the association between disulfidptosis and stroke by analyzing gene sequencing data from peripheral blood samples of stroke patients.

METHODS

Differential gene expression analysis identified a set of disulfidptosis-related genes (DRGs) significantly associated with stroke. Initial exploration identified 32 DRGs and their interactions. Our study encompassed several analyses to understand the molecular mechanisms of DRGs in stroke. Weighted Gene Co-Expression Network Analysis (WGCNA) uncovered modules of co-expressed genes in stroke samples, and differentially expressed gene (DEG) analysis highlighted 1643 key genes.

RESULTS

These analyses converged on four hub genes of DRGs (SLC2A3, SLC2A14, SLC7A11, NCKAP1) associated with stroke. Immune cell composition analysis indicated positive correlations between hub genes and macrophages M1, M2, and neutrophils and negative associations with CD4+ and CD8+ T cells, B cells, and NK cells. Sub-cluster analysis revealed two distinct clusters with different immune cell expression profiles. Gene Set Enrichment Analysis (GSEA) demonstrated enrichment of apoptosis-related pathways, neurotrophin signaling, and actin cytoskeleton regulation. Associations between hub genes and apoptosis, necroptosis, ferroptosis, and cuproptosis, were also identified.

CONCLUSION

These results suggest that the DRG hub genes are interconnected with various cell death pathways and immune processes, potentially contributing to stroke pathological development.

LCP1 knockdown in monocyte-derived macrophages: mitigating ischemic brain injury and shaping immune cell signaling and metabolism

Rationale: Ischemic stroke poses a significant health burden with limited treatment options. Lymphocyte Cytosolic Protein 1 (LCP1) facilitates cell migration and immune responses by aiding in actin polymerization, cytoskeletal rearrangements, and phagocytosis. We have demonstrated that the long non-coding RNA (lncRNA) Maclpil silencing in monocyte-derived macrophages (MoDMs) led to LCP1 inhibition, reducing ischemic brain damage. However, the role of LCP1 of MoDMs in ischemic stroke remains unknown. Methods and Results: We investigated the impact of LCP1 on ischemic brain injury and immune cell signaling and metabolism. We found that knockdown of LCP1 in MoDMs demonstrated robust protection against ischemic infarction and improved neurological behaviors in mice. Utilizing the high-dimensional CyTOF technique, we demonstrated that knocking down LCP1 in MoDMs led to a reduction in neuroinflammation and attenuation of lymphopenia, which is linked to immunodepression. It also showed altered immune cell signaling by modulating the phosphorylation levels of key kinases and transcription factors, including p-PLCg2, p-ERK1/2, p-EGFR, p-AKT, and p4E-BP1 as well as transcription factors like p-STAT1, p-STAT3, and p-STAT4. Further bioinformatic analysis indicated that Akt and EGFR are particularly involved in fatty acid metabolism and glycolysis. Indeed, single-cell sequencing analysis confirmed that enrichment of fatty acid and glycolysis metabolism in Lcp1high monocytes/macrophages. Furthermore, Lcp1high cells exhibited enhanced oxidative phosphorylation, chemotaxis, migration, and ATP biosynthesis pathways. In vitro experiments confirmed the role of LCP1 in regulating mitochondrial function and fatty acid uptake. Conclusions: These findings contribute to a deeper understanding of LCP1 in the context of ischemic stroke and provide valuable insights into potential therapeutic strategies targeting LCP1 and metabolic pathways, aiming to attenuating neuroinflammation and lymphopenia.

Transcranial direct current stimulation for post-stroke dysphagia: a meta-analysis

BACKGROUND

Strokes may cause some swallowing difficulty or associated dysphagia in 25-80% of patients. This phenomenon has been linked to increased morbidity and mortality. Therefore, the aim of this study was to evaluate the efficacy of transcranial direct current stimulation in patients with dysphagia in post-stroke patients.

METHODS

A systematic search in PubMed, Scopus, Web of Science and MEDLINE was conducted. The articles must have to evaluate an intervention that included transcranial direct current stimulation; the sample had to consist exclusively of patients with post-stroke dysphagia; and the experimental design consisted of randomized controlled trial. Difference in mean differences and their 95% confidence interval were calculated as the between-group difference in means divided by the pooled standard deviation. The I2 statistic was used to determine the degree of heterogeneity.

RESULTS

Of the 9 investigations analyzed, all applied transcranial direct current stimulation in combination with conventional dysphagia therapy to the experimental group. All the studies analyzed identified improvements in swallowing function and meta-analysis confirmed their strong effect on reducing the risk of penetration and aspiration (Hedges's g = 0.55). The results showed that participants who received transcranial direct current stimulation significantly improved swallowing function.

CONCLUSIONS

Transcranial direct current stimulation has positive effects in the treatment of poststroke dysphagia by improving swallowing function, oral and pharyngeal phase times and the risk of penetration and aspiration. Furthermore, its combination with conventional dysphagia therapy, balloon dilatation with catheter or training of the swallowing muscles ensures improvement of swallowing function. PROSPERO registration ID CRD42022314949.

Post-stroke immunosuppression: Exploring potential implications beyond infections

Stroke is a leading cause of mortality and disability. It occurs when cerebral blood flow is disrupted via vascular occlusion or rupture, causing tissue damage. Research has extensively examined the role of the immune response in stroke pathophysiology, focusing on infiltrated immune cells and inflammatory molecules. However, the stroke's impact on immune physiology remains underexplored. While initially stroke triggers the activation of peripheral inflammation, a subsequent profound immunosuppression occurs in a matter of hours/days. This response, potentially shielding the brain from excessive inflammation, significantly affects stroke patients. Beyond rendering patients more susceptible to infections, immunosuppression generates diverse consequences by disrupting immune system functions that are crucial for organ homeostasis. This review explores the effects of immunosuppression on stroke patients, shedding light on potential issues in immune organs such as the spleen and bone marrow, as well as non-immune organs like the small intestine, liver and heart. By synthesizing existing literature and offering additional insights, this manuscript highlights the multifaceted impact of post-stroke immunosuppression.

Molecular chaperones in stroke-induced immunosuppression

Stroke-induced immunosuppression is a process that leads to peripheral suppression of the immune system after a stroke and belongs to the central nervous system injury-induced immunosuppressive syndrome. Stroke-induced immunosuppression leads to increased susceptibility to post-stroke infections, such as urinary tract infections and stroke-associated pneumonia, worsening prognosis. Molecular chaperones are a large class of proteins that are able to maintain proteostasis by directing the folding of nascent polypeptide chains, refolding misfolded proteins, and targeting misfolded proteins for degradation. Various molecular chaperones have been shown to play roles in stroke-induced immunosuppression by modulating the activity of other molecular chaperones, cochaperones, and their associated pathways. This review summarizes the role of molecular chaperones in stroke-induced immunosuppression and discusses new approaches to restore host immune defense after stroke.

Construction and evaluation of a nomogram prediction model for aspiration pneumonia in patients with acute ischemic stroke

Background

Aspiration Pneumonia (AP) is a leading cause of death in patients with Acute Ischemic Stroke (AIS). Early detection, diagnosis and effective prevention measures are crucial for improving patient prognosis. However, there is a lack of research predicting AP occurrence after AIS. This study aimed to identify risk factors and develop a nomogram model to determine the probability of developing AP after AIS.

Method

A total of 3258 AIS patients admitted to Jinshan Hospital of Fudan University between January 1, 2016, and August 20, 2022, were included. Among them, 307 patients were diagnosed with AP (AP group), while 2951 patients formed the control group (NAP group). Univariate and multivariate logistic regression analyses were conducted to identify relevant risk factors for AP after AIS. These factors were used to establish a scoring system and develop a nomogram model using R software.

Results

Univariate analysis revealed 20 factors significantly associated (P < 0.05) with the development of AP after AIS. These factors underwent multivariate logistic regression analysis, which identified age (elderly), National Institute of Health Stroke Scale (NIHSS) score, dysphagia, atrial fibrillation, cardiac insufficiency, renal insufficiency, hepatic insufficiency, elevated Fasting Blood Glucose (FBG), elevated C-Reactive Protein (CRP), elevated Neutrophil percentage (NEUT%), and decreased prealbumin as independent risk factors. A nomogram model incorporating these 11 risk factors was constructed, with a C-index of 0.872 (95 % CI: 0.845-0.899), indicating high accuracy. Calibration and clinical decision analyses demonstrated the model's reliability and clinical value.

Conclusion

A nomogram model incorporating age, NIHSS score, dysphagia, atrial fibrillation, cardiac insufficiency, renal insufficiency, hepatic insufficiency, FBG, CRP, NEUT%, and prealbumin effectively predicts AP risk in AIS patients. This model provides guidance for early intervention strategies, enabling the identification of high-risk individuals for timely preventive measures.

Review of research progress on the role of the effective components of traditional Chinese medicine in sepsis with multiple organ dysfunction

The concept of sepsis has recently evolved from one of a 'systemic inflammatory response syndrome caused by infection' to a 'severe, potentially fatal organic dysfunction caused by an inadequate or imbalanced host response to infection'. Organ dysfunction is closely related to sepsis. Multiple organ dysfunction syndrome (MODS) is the most serious outcome of sepsis, often leading to a poor prognosis. However, specific drugs for sepsis and MODS caused by sepsis remain undetermined, and the fatality rate is relatively high. Under the guidance of modern medicine, traditional Chinese medicine (TCM) has gained a wealth of experience in the prevention and treatment of sepsis and plays a key role via the effects of its numerous components, pathways and targets. This study used 'Sepsis', 'Organ dysfunction' and 'Traditional Chinese medicine' as strategies for searching the databases of Chinese National Knowledge Infrastructure, Wanfang, PubMed and The Web of Science. This paper presents an overview of the current status of TCM component formulations for preventing and treating sepsis with MODS to provide a theoretical basis for clinical treatment and drug development.

Research progress on the roles of neurovascular unit in stroke-induced immunosuppression

A complex pathophysiological mechanism is involved in brain injury following cerebral infarction. The neurovascular unit (NVU) is a complex multi-cellular structure consisting of neurons, endothelial cells, pericyte, astrocyte, microglia and extracellular matrix, etc. The dyshomeostasis of NVU directly participates in the regulation of inflammatory immune process. The components of NVU promote inflammatory overreaction and synergize with the overactivation of autonomic nervous system to initiate stroke-induced immunodepression (SIID). SIID can alleviate the damage caused by inflammation, however, it also makes stroke patients more susceptible to infection, leading to systemic damage. This article reviews the mechanism of SIID and the roles of NVU in SIID, to provide a perspective for reperfusion, prognosis and immunomodulatory therapy of cerebral infarction.

IL-1 Beta-A Biomarker for Ischemic Stroke Prognosis and Atherosclerotic Lesions of the Internal Carotid Artery

Background and Objectives: Stroke is a leading cause of mortality and morbidity worldwide. Treatment of this pathology is still under development and its risk factors remain to be determined. Therefore, we aim to determine the role of interleukin-1 beta in atherosclerotic lesions of the internal carotid artery as a risk factor for stroke and the role of this biomarker in stroke prognosis. Materials and Methods: This study enrolled 56 patients diagnosed with ischemic stroke in the anterior vascular territory (AVT) and posterior vascular territory (PVT). All the patients had venous blood collected at admission and 7 days after the onset of the cerebral ischemia in order to determine the plasma concentration of interleukin-1 beta. At the same time, an extracranial carotid ultrasound was performed. Results: The interleukin-1 beta collected at admission was positively correlated with the NIHSS at admission (Pearson index 0.424), and both measurements were correlated with carotid stenosis (Spearmen correlation index of 0.529 and 0.653, respectively). Conclusions: Interleukin-1 beta could be a reliable biomarker for stroke prognosis and the development of atherosclerotic lesions of the internal carotid.

Clinical characteristics and risk factors for bilateral lateral geniculate body pathology: a systematic review of the literature

BACKGROUND

Case presentation of acute onset bilateral painless vision loss caused by bilateral infarction of the lateral geniculate bodies (LGB) and a systematic review of the literature.

METHODS

A descriptive case report is presented on a 17-year-old female diagnosed with acute pancreatitis who developed acute onset bilateral painless vision loss. A systematic literature review of cases with bilateral LGB lesions was conducted across three electronic databases (PubMed/PubMed Central/MEDLINE, Scopus, and ScienceDirect). The review was conducted in concordance with PRISMA guidelines and prospectively registered on PROSPERO (CRD42022362491).

RESULTS

The reported 17-year-old female was found to have MRI findings consistent with bilateral hemorrhagic infarction of the LGB and Purtscher-like retinopathy. A systematic literature review of bilateral LGB infarction yielded 23 records for analysis. 19/23 (82.6%) of reported cases occurred in women. Bilateral vision loss was noted in all cases. The average reported age was 27 years old with a range from 2-50. Gastrointestinal pathology (e.g., pancreatitis, gastroenteritis) was present in 8/23 (34.7%) of cases. 8/23 (34.7%) cases had neuroimaging or pathological evidence of hemorrhagic transformation of the infarct. Most cases experienced partial recovery of visual loss; only one case (4.7%) had complete visual recovery. 9/23 (39.1%) cases were reported from the United States and 4/23 (17.3%) from India.

CONCLUSIONS

Bilateral LGB lesion is a rare cause of vision loss, typically caused by systemic diseases and with female preponderance. Purported pathophysiology relates to increased vulnerability of the LGB to ischemic and metabolic stress.

Risk Factors for Post-Stroke Pneumonia in a Patient Population with Subacute Stroke: A Retrospective Cohort Study

The risk of pneumonia and death is higher in acute stroke patients with signs of pulmonary infection on chest computed tomography (CT) at admission. However, few reports have examined the incidence of pneumonia and its predictors in subacute stroke patients. The aim of this study was to examine factors related to post-stroke pneumonia in subacute stroke patients. A total of 340 subacute stroke patients were included. Univariable logistic regression analysis was performed using variables that may contribute to pneumonia, with the development of pneumonia as the dependent variable. Multivariable logistic regression analysis using the three independent variables with the lowest p-values on the univariable logistic regression analysis was also performed to calculate adjusted odds ratios. Twenty-two patients developed pneumonia during hospitalization. The univariable logistic regression analysis showed that the top three items were serum albumin (Alb), functional Oral Intake Scale (FOIS) score, and signs of pulmonary infection on chest CT at admission. Multivariable logistic regression analysis adjusted for these three items showed that the presence of signs of pulmonary infection on chest CT at admission was the independent variable (OR: 4.45; 95% CI: 1.54-12.9). When signs of pulmonary infection are seen on admission chest CT, careful follow-up is necessary because pneumonia is significantly more likely to occur during hospitalization.

Predictors of stroke-associated pneumonia and the predictive value of neutrophil percentage-to-albumin ratio

BACKGROUND

Early recognition of stroke-associated pneumonia (SAP) is critical to reducing morbidity and mortality associated with SAP. This study investigated the predictors of SAP, and the predictive value of the neutrophil percentage-to-albumin ratio (NPAR) for SAP.

METHODS

This retrospective cohort study was conducted among stroke patients admitted to Jordan University Hospital from January 2015 to May 2021. Multivariable logistic regression was used to identify independent predictors for SAP. The predictive performance was assessed using C-statistics, described as the area under the receiver-operating characteristic curve (AUC, ROC) with a 95% confidence interval.

RESULTS

Four hundred and six patients were included in the analysis, and the prevalence of SAP was 19.7%. Multivariable logistic analysis showed that males (Adjusted Odds Ratio (AOR): 5.74; 95% Confidence Interval (95%CI): 2.04-1 6.1)], dysphagia (AOR: 5.29; 95% CI: 1.80-15.5), hemiparesis (AOR: 3.27; 95% CI: 1.13-9.47), lower GCS score (AOR: 0.73; 95% CI: 0.58-0.91), higher levels of neutrophil-lymphocyte ratio (NLR) (AOR: 1.15; 95% CI: 1.07-1.24), monocyte-lymphocyte ratio (MLR) (AOR: 1.49; 95% CI: 1.13-1.96), and neutrophil percentage to albumin ratio (NPAR) (AOR: 1.53; 95% CI: 1.33-1.76) were independent predictors of SAP. The NPAR demonstrated a significantly higher AUC than both the NLR (0.939 versus 0.865, Z = 3.169, p = 0.002) and MLR (0.939 versus 0.842, Z = 3.940, p < 0.001). The AUCs of the NLR and MLR were comparable (0.865 versus 0.842, Z = 1.274, p = 0.203).

CONCLUSION

Male gender, dysphagia and hemiparesis were the strongest predictors of SAP, and NPAR has an excellent performance in predicting SAP which was better than high NLR and MLR.

Neuroprotective Effects of Phenolic Antioxidant Tert-butylhydroquinone (tBHQ) in Brain Diseases

Human life and health are gravely threatened by brain diseases. The onset and progression of the illnesses are influenced by a variety of factors, including pathogenic causes, environmental factors, mental issues, etc. According to scientific studies, neuroinflammation and oxidative stress play a significant role in the development and incidence of brain diseases by producing pro-inflammatory cytokines and oxidative tissue damage to induce inflammation and apoptosis. Neuroinflammation, oxidative stress, and oxidative stress-related changes are inseparable factors in the etiology of several brain diseases. Numerous neurodegenerative diseases have undergone substantial research into the therapeutic alternatives that target oxidative stress, the function of oxidative stress, and the possible therapeutic use of antioxidants. Formerly, tBHQ is a synthetic phenolic antioxidant, which has been widely used as a food additive. According to recent researches, tBHQ can suppress the processes that lead to neuroinflammation and oxidative stress, which offers a fresh approach to treating brain diseases. In order to achieve the goal of decreasing inflammation and apoptosis, tBHQ is a specialized nuclear factor erythroid 2-related factor (Nrf2) activator that decreases oxidative stress and enhances antioxidant status by upregulating the Nrf2 gene and reducing nuclear factor kappa-B (NF-κB) activity. This article reviews the effects of tBHQ on neuroinflammation and oxidative stress in recent years and looks into how tBHQ inhibits neuroinflammation and oxidative stress through human, animal, and cell experiments to play a neuroprotective role in Alzheimer's disease (AD), stroke, depression, and Parkinson's disease (PD). It is anticipated that this article will be useful as a reference for upcoming research and the creation of drugs to treat brain diseases.

Inpatient Rehabilitation Outcomes after Primary Severe Haemorrhagic Stroke: A Retrospective Study Comparing Surgical versus Non-Surgical Management

BACKGROUND

Haemorrhagic stroke, accounting for 10-20% of all strokes, often requires decompressive surgery as a life-saving measure for cases with massive oedema and raised intracranial pressure. This study was conducted to compare the demographics, characteristics and rehabilitation profiles of patients with severe haemorrhagic stroke who were managed surgically versus those who were managed non-surgically.

METHODS

A single-centre retrospective study of electronic medical records was conducted over a 3-year period from 1 January 2018 to 31 December 2020. The inclusion criteria were first haemorrhagic stroke, age of >18 years and an admission Functional Independence Measure (FIM™) score of 18-40 upon admission to the rehabilitation centre. The primary outcome measure was discharge FIM™. Secondary outcome measures included modified Rankin Scale (mRS), rehabilitation length of stay (RLOS) and complication rates.

RESULTS

A total of 107 patients' records were analysed; 45 (42.1%) received surgical intervention and 62 (57.9%) patients underwent non-surgical management. Surgically managed patients were significantly younger than non-surgical patients, with a mean age of [surgical 53.1 (SD 12) vs. non-surgical 61.6 (SD 12.3), p = 0.001]. Admission FIM was significantly lower in the surgical vs. non-surgical group [23.7 (SD6.7) vs. 26.71 (SD 7.4), p = 0.031). However, discharge FIM was similar between both groups [surgical 53.91 (SD23.0) vs. non-surgical 57.0 (SD23.6), p = 0.625). Similarly, FIM gain (surgical 30.1 (SD 21.1) vs. non-surgical 30.3 (SD 21.1), p = 0.094) and RLOS [surgical 56.2 days (SD 21.5) vs. non-surgical 52.0 days (SD 23.4), p = 0.134) were not significantly different between groups. The majority of patients were discharged home (surgical 73.3% vs. non-surgical 74.2%, p = 0.920) despite a high level of dependency.

CONCLUSIONS

Our findings suggest that patients with surgically managed haemorrhagic stroke, while older and more dependent on admission to rehabilitation, achieved comparable FIM gains, discharge FIM and discharge home rates after ~8 weeks of rehabilitation. This highlights the importance of rehabilitation, especially for surgically managed haemorrhagic stroke patients.

The Potential of Gut Microbiota in Prediction of Stroke-Associated Pneumonia

BACKGROUND

Stroke-associated pneumonia (SAP) is a common stroke complication, and the changes in the gut microbiota composition may play a role. Our study aimed to evaluate the predictive ability of gut microbiota for SAP.

METHODS

Acute ischemic stroke patients were prospectively enrolled and divided into two groups based on the presence or absence of SAP. The composition of gut microbiota was characterized by the 16S RNA Miseq sequencing. The gut microbiota that differed significantly between groups were incorporated into the conventional risk scores, the Acute Ischemic Stroke-Associated Pneumonia Score (AIS-APS), and the Age, Atrial fibrillation, Dysphagia, Sex, Stroke Severity Score (A2DS2). The predictive performances were assessed in terms of the area under the curve (AUC), the Net Reclassification Improvement (NRI), and the Integrated Discrimination Improvement (IDI) indices.

RESULTS

A total of 135 patients were enrolled, of whom 43 had SAP (31%). The short-chain fatty acids (SCFAs)-producing bacteria, such as Bacteroides, Fusicatenibacter, and Butyricicoccus, were decreased in the SAP group. The integrated models showed better predictive ability for SAP (AUC = 0.813, NRI = 0.333, p = 0.052, IDI = 0.038, p = 0.018, for AIS-APS; AUC = 0.816, NRI = 0.575, p < 0.001, IDI = 0.043, p = 0.007, for A2DS2) in comparison to the differential genera (AUC = 0.699) and each predictive score (AUCAISAPS = 0.777; AUCA2DS2 = 0.777).

CONCLUSIONS

The lower abundance of SCFAs-producing gut microbiota after acute ischemic stroke was associated with SAP and may play a role in SAP prediction.

As an inhibitor of norepinephrine release, dexmedetomidine provides no improvement on stroke-associated pneumonia in mice

Background: Dexmedetomidine (DEX) is commonly employed as a sedative agent to attenuate sympathetic tone and reduce norepinephrine (NE) levels. In the context of stroke-associated pneumonia (SAP), which is believed to arise from heightened sympathetic nervous system activity and elevated NE release, the precise influence of DEX remains uncertain. Methods: In this study, we generated an SAP model using middle cerebral artery occlusion (MCAO) and examined NE levels, immunological statuses in the brain and periphery, pneumonia symptoms, and extent of infarction. We aimed to determine the effects of DEX on SAP and explore the underlying. Despite its potential to reduce NE levels, DEX did not alleviate SAP symptoms or decrease the infarct area. Interestingly, DEX led to an increase in spleen size and spleen index. Furthermore, we observed a decrease in the CD3+ T cell population in both the blood and brain, but an increase in the spleen following DEX administration. The precise mechanism linking decreased CD3+ T cells and DEX's role in SAP requires further investigation. Conclusion: The clinical use of DEX in stroke patients should be approached with caution, considering its inability to alleviate SAP symptoms and reduce the infarct area. Further research is necessary to fully understand the relationship between decreased CD3+ T cells and DEX's influence on SAP.

IL-7 producing immunotherapy improves ex vivo T cell functions of immunosenescent patients, especially post hip fracture

Following acute stress such as trauma or sepsis, most of critically ill elderly patients become immunosuppressed and susceptible to secondary infections and enhanced mortality. We have developed a virus-based immunotherapy encoding human interleukin-7 (hIL-7) aiming at restoring both innate an adaptative immune homeostasis in these patients. We assessed the impact of this encoded hIL-7 on the ex vivo immune functions of T cells from PBMC of immunosenescent patients with or without hip fracture. T-cell ex vivo phenotyping was characterized in terms of senescence (CD57), IL-7 receptor (CD127) expression, and T cell differentiation profile. Then, post stimulation, activation status, and functionality (STAT5/STAT1 phosphorylation and T cell proliferation assays) were evaluated by flow cytometry. Our data show that T cells from both groups display immunosenescence features, express CD127 and are activated after stimulation by virotherapy-produced hIL-7-Fc. Interestingly, hip fracture patients exhibit a unique functional ability: An important T cell proliferation occurred compared to controls following stimulation with hIL-7-Fc. In addition, stimulation led to an increased naïve T cell as well as a decreased effector memory T cell proportions compared to controls. This preliminary study indicates that the produced hIL-7-Fc is well recognized by T cells and initiates IL-7 signaling through STAT5 and STAT1 phosphorylation. This signaling efficiently leads to T cell proliferation and activation and enables a T cell "rejuvenation." These results are in favor of the clinical development of the hIL-7-Fc expressing virotherapy to restore or induce immune T cell responses in immunosenescent hip fracture patients.

Nicotinamide Deteriorates Post-Stroke Immunodepression Following Cerebral Ischemia-Reperfusion Injury in Mice

(1) Background: Inducing experimental stroke leads to biphasic immune responses, where the early activation of immune functions is followed by severe immunosuppression accompanied by spleen and thymus atrophy. Nicotinamide, a water-soluble B-group vitamin, is a known neuroprotectant against brain ischemia in animal models. We examined the effect of nicotinamide on the central and peripheral immune response in experimental stroke models. (2) Methods: Nicotinamide (500 mg/kg) or saline was intravenously administered to C57BL/6 mice during reperfusion after transiently occluding the middle cerebral artery or after LPS injection. On day 3, the animals were examined for behavioral performance and were then sacrificed to assess brain infarction, blood-brain barrier (BBB) integrity, and the composition of immune cells in the brain, thymus, spleen, and blood using flow cytometry. (3) Results: Nicotinamide reduced brain infarction and microglia/macrophage activation following MCAo (p < 0.05). Similarly, in LPS-injected mice, microglia/macrophage activation was decreased upon treatment with nicotinamide (p < 0.05), suggesting a direct inhibitory effect of nicotinamide on microglia/macrophage activation. Nicotinamide decreased the infiltration of neutrophils into the brain parenchyma and ameliorated Evans blue leakage (p < 0.05), suggesting that a decreased infiltration of neutrophils could, at least partially, be the result of a more integrated BBB structure following nicotinamide treatment. Our studies also revealed that administering nicotinamide led to retarded B-cell maturation in the spleen and subsequently decreased circulating B cells in the thymus and bloodstream (p < 0.05). (4) Conclusions: Cumulatively, nicotinamide decreased brain inflammation caused by ischemia-reperfusion injury, which was mediated by a direct anti-inflammatory effect of nicotinamide and an indirect protective effect on BBB integrity. Administering nicotinamide following brain ischemia resulted in a decrease in circulating B cells. This warrants attention with respect to future clinical applications.