The efficacy of therapeutic hypothermia in patients with poor-grade aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

BACKGROUND: This study evaluates the effectiveness of Therapeutic Hypothermia (TH) in treating poor-grade aneurysmal subarachnoid hemorrhage (SAH), focusing on functional outcomes, mortality, and complications such as vasospasm, delayed cerebral ischemia (DCI), and hydrocephalus. METHODS: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, a comprehensive literature search was conducted across multiple databases, including Medline, Embase, and Cochrane Central, up to November 2023. Nine studies involving 368 patients were selected based on eligibility criteria focusing on TH in poor-grade SAH patients. Data extraction, bias assessment, and evidence certainty were systematically performed. RESULTS: The primary analysis of unfavorable outcomes in 271 participants showed no significant difference between the TH and standard care groups (risk ratio [RR], 0.87). However, a significant reduction in vasospasm was observed in the TH group (RR, 0.63) among 174 participants. No significant differences were found in DCI, hydrocephalus, and mortality rates in the respective participant groups. CONCLUSIONS: TH did not significantly improve primary unfavorable outcomes in poor-grade SAH patients. However, the reduction in vasospasm rates indicates potential specific benefits. The absence of significant findings in other secondary outcomes and mortality highlights the need for further research to better understand TH's role in treating this patient population.

Chemical and perfusion markers as predictors of moyamoya disease progression and complication types.

To investigate the association between chemical markers (triglyceride, C-reactive protein (CRP), and inflammation markers) and perfusion markers (relative cerebral vascular reserve (rCVR)) with moyamoya disease progression and complication types. A total of 314 patients diagnosed with moyamoya disease were included. Triglyceride and CRP levels were assessed and categorized based on Korean guidelines for dyslipidemia and CDC/AHA guidelines, respectively. Perfusion markers were evaluated using Diamox SPECT. Cox proportional hazard analysis was performed to examine the relationship between these markers and disease progression, as well as complication types (ischemic stroke, hemorrhagic stroke, and rCVR deterioration). Elevated triglyceride levels (≥ 200) were significantly associated with higher likelihood of end-point events (HR: 2.292, CI 1.00-4.979, P = 0.03). Severe decreased rCVR findings on Diamox SPECT were also significantly associated with end-point events (HR: 3.431, CI 1.254-9.389, P = 0.02). Increased CRP levels and white blood cell (WBC) count were significantly associated with moyamoya disease progression. For hemorrhagic stroke, higher triglyceride levels were significantly associated with end-point events (HR: 5.180, CI 1.355-19.801, P = 0.02). For ischemic stroke, severe decreased rCVR findings on Diamox SPECT (HR: 5.939, CI 1.616-21.829, P < 0.01) and increased CRP levels (HR: 1.465, CI 1.009-2.127, P = 0.05) were significantly associated with end-point events. Elevated triglyceride, CRP, and inflammation markers, as well as decreased rCVR, are potential predictors of moyamoya disease progression and complication types. Further research is warranted to understand their role in disease pathophysiology and treatment strategies.

The Unique Relationship between Neuro-Critical Care and Critical Illness-Related Corticosteroid Insufficiency : Implications for Neurosurgeons in Neuro-Critical Care.

The brain houses vital hormonal regulatory structures such as the hypothalamus and pituitary gland, which may confer unique susceptibilities to critical illness-related corticosteroid insufficiency (CIRCI) in patients with neurological disorders. In addition, the frequent use of steroids for therapeutic purposes in various neurological conditions may lead to the development of steroid insufficiency. This abstract aims to highlight the significance of understanding these relationships in the context of patient care and management for physicians. Neurological disorders may predispose patients to CIRCI due to the role of the brain in hormonal regulation. Early recognition of CIRCI in the context of neurological diseases is essential to ensure prompt and appropriate intervention. Moreover, the frequent use of steroids for treating neurological conditions can contribute to the development of steroid insufficiency, further complicating the clinical picture. Physicians must be aware of these unique interactions and be prepared to evaluate and manage patients with CIRCI and steroid insufficiency in the context of neurological disorders. This includes timely diagnosis, appropriate steroid administration, and careful monitoring for potential adverse effects. A comprehensive understanding of the interplay between neurological disease, CIRCI, and steroid insufficiency is critical for optimizing patient care and outcomes in this complex patient population.

Aquaporin-4 Deficiency is Associated with Cognitive Impairment and Alterations in astrocyte-neuron Lactate Shuttle.

Cognitive impairment refers to notable declines in cognitive abilities including memory, language, and emotional stability leading to the inability to accomplish essential activities of daily living. Astrocytes play an important role in cognitive function, and homeostasis of the astrocyte-neuron lactate shuttle (ANLS) system is essential for maintaining cognitive functions. Aquaporin-4 (AQP-4) is a water channel expressed in astrocytes and has been shown to be associated with various brain disorders, but the direct relationship between learning, memory, and AQP-4 is unclear. We examined the relationship between AQP-4 and cognitive functions related to learning and memory. Mice with genetic deletion of AQP-4 showed significant behavioral and emotional changes including hyperactivity and instability, and impaired cognitive functions such as spatial learning and memory retention. 18 F-FDG PET imaging showed significant metabolic changes in the brains of AQP-4 knockout mice such as reductions in glucose absorption. Such metabolic changes in the brain seemed to be the direct results of changes in the expression of metabolite transporters, as the mRNA levels of multiple glucose and lactate transporters in astrocytes and neurons were significantly decreased in the cortex and hippocampus of AQP-4 knockout mice. Indeed, AQP-4 knockout mice showed significantly higher accumulation of both glucose and lactate in their brains compared with wild-type mice. Our results show that the deficiency of AQP-4 can cause problems in the metabolic function of astrocytes and lead to cognitive impairment, and that the deficiency of AQP4 in astrocyte endfeet can cause abnormalities in the ANLS system.

Efficacy of Acetylcysteine and Selenium in Aneurysmal Subarachnoid Hemorrhage Patients: A Prospective, Multicenter, Single Blind Randomized Controlled Trial.

BACKGROUND: Subarachnoid hemorrhage (SAH) patients have oxidative stress results in inflammation, tissue degeneration and neuronal damage. These deleterious effects cause aggravation of the perihematomal edema (PHE), vasospasm, and even hydrocephalus. We hypothesized that antioxidants may have a neuroprotective role in acute aneurysmal SAH (aSAH) patients. METHODS: We conducted a prospective, multicenter randomized (single blind) trial between January 2017 and October 2019, investigating whether antioxidants (acetylcysteine and selenium) have the potential to improve the neurologic outcome in aSAH patients. The antioxidant patient group received antioxidants of acetylcysteine (2,000 mg/day) and selenium (1,600 µg/day) intravenously (IV) for 14 days. These drugs were administrated within 24 hours of admission. The non-antioxidant patient group received a placebo IV. RESULTS: In total, 293 patients were enrolled with 103 patients remaining after applying the inclusion and exclusion criteria. No significant differences were observed in the baseline characteristics between the antioxidant (n = 53) and non-antioxidant (n = 50) groups. Among clinical factors, the duration of intensive care unit (ICU) stay was significantly shortened in patients who received antioxidants (11.2, 95% confidence interval [CI], 9.7-14.5 vs. 8.3, 95% CI, 6.2-10.2 days, P = 0.008). However, no beneficial effects were observed on radiological outcomes. CONCLUSION: In conclusion, antioxidant treatment failed to show the reduction of PHE volume, mid-line shifting, vasospasm and hydrocephalus in acute SAH patients. A significant reduction in ICU stay was observed but need more optimal dosing schedule and precise outcome targets are required to clarify the clinical impacts of antioxidants in these patients. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0004628.

The Unique Relationship between Neuro-Critical Care and Critical Illness-Related Corticosteroid Insufficiency : Implications for Neurosurgeons in Neuro-Critical Care.

The brain houses vital hormonal regulatory structures such as the hypothalamus and pituitary gland, which may confer unique susceptibilities to critical illness-related corticosteroid insufficiency (CIRCI) in patients with neurological disorders. In addition, the frequent use of steroids for therapeutic purposes in various neurological conditions may lead to the development of steroid insufficiency. This abstract aims to highlight the significance of understanding these relationships in the context of patient care and management for physicians. Neurological disorders may predispose patients to CIRCI due to the role of the brain in hormonal regulation. Early recognition of CIRCI in the context of neurological diseases is essential to ensure prompt and appropriate intervention. Moreover, the frequent use of steroids for treating neurological conditions can contribute to the development of steroid insufficiency, further complicating the clinical picture. Physicians must be aware of these unique interactions and be prepared to evaluate and manage patients with CIRCI and steroid insufficiency in the context of neurological disorders. This includes timely diagnosis, appropriate steroid administration, and careful monitoring for potential adverse effects. A comprehensive understanding of the interplay between neurological disease, CIRCI, and steroid insufficiency is critical for optimizing patient care and outcomes in this complex patient population.

Proteomic analysis predicts anti-angiogenic resistance in recurred glioblastoma.

BACKGROUND: Recurrence is common in glioblastoma multiforme (GBM) because of the infiltrative, residual cells in the tumor margin. Standard therapy for GBM consists of surgical resection followed by chemotherapy and radiotherapy, but the median survival of GBM patients remains poor (~ 1.5 years). For recurrent GBM, anti-angiogenic treatment is one of the common treatment approaches. However, current anti-angiogenic treatment modalities are not satisfactory because of the resistance to anti-angiogenic agents in some patients. Therefore, we sought to identify novel prognostic biomarkers that can predict the therapeutic response to anti-angiogenic agents in patients with recurrent glioblastoma. METHODS: We selected patients with recurrent GBM who were treated with anti-angiogenic agents and classified them into responders and non-responders to anti-angiogenic therapy. Then, we performed proteomic analysis using liquid-chromatography mass spectrometry (LC-MS) with formalin-fixed paraffin-embedded (FFPE) tissues obtained from surgical specimens. We conducted a gene-ontology (GO) analysis based on protein abundance in the responder and non-responder groups. Based on the LC-MS and GO analysis results, we identified potential predictive biomarkers for anti-angiogenic therapy and validated them in recurrent glioblastoma patients. RESULTS: In the mass spectrometry-based approach, 4957 unique proteins were quantified with high confidence across clinical parameters. Unsupervised clustering analysis highlighted distinct proteomic patterns (n = 269 proteins) between responders and non-responders. The GO term enrichment analysis revealed a cluster of genes related to immune cell-related pathways (e.g., TMEM173, FADD, CD99) in the responder group, whereas the non-responder group had a high expression of genes related to nuclear replisome (POLD) and damaged DNA binding (ERCC2). Immunohistochemistry of these biomarkers showed that the expression levels of TMEM173 and FADD were significantly associated with the overall survival and progression-free survival of patients with recurrent GBM. CONCLUSIONS: The candidate biomarkers identified in our protein analysis may be useful for predicting the clinical response to anti-angiogenic agents in patients with recurred GBM.

Upregulation of AQP4 Improves Blood-Brain Barrier Integrity and Perihematomal Edema Following Intracerebral Hemorrhage.

In intracerebral hemorrhage (ICH), delayed secondary neural damages largely occur from perihematomal edema (PHE) resulting from the disruption of the blood-brain barrier (BBB). PHE is often considered the principal cause of morbidity and mortality in patients with ICH. Nevertheless, the main cellular mechanism as well as the specific BBB component involved in the formation of PHE after ICH remains elusive. Herein, we evaluated the role of AQP4, a water channel expressed on the astrocytes of the BBB, in the formation of PHE in ICH. The static and dynamic functions of the BBB were evaluated by analyzing the microstructure and leakage assay. Protein changes in the PHE lesion were analyzed and the control mechanism of AQP4 expression by reactive oxygen species was also investigated. Delayed PHE formation due to BBB disruption after ICH was confirmed by the decreased coverage of multiple BBB components and increased dynamic leakages. Microstructure assay showed that among the BBB components, AQP4 showed a markedly decreased expression in the PHE lesions. The decrease in AQP4 was due to microenvironmental ROS derived from the hemorrhage and was restored by treatment with ROS scavenger. AQP4-deficient mice had significantly larger PHE lesions and unfavorable survival outcomes compared with wild-type mice. Our data identify AQP4 as a specific BBB-modulating target for alleviating PHE in ICH. Further comprehensive studies are needed to form the preclinical basis for the use of AQP4 enhancers as BBB modulators for preventing delayed cerebral edema after ICH.

Immunological characteristics and possible pathogenic role of urinary CD11c+ macrophages in lupus nephritis.

OBJECTIVES: Kidney-infiltrating immune cells can contribute to the pathogenesis of lupus nephritis (LN). We investigated the immunological characteristics of CD11c+ macrophages and their functions associated with the pathogenesis of LN. METHODS: CD11c+ macrophages were examined in the urine samples of patients with LN. Phenotypic markers and pro-inflammatory cytokine expression levels were analysed by flow cytometry. To determine the origin of urinary macrophages, peripheral monocytes were treated with sera from patients with systemic lupus erythematosus (SLE). The pathogenic role of CD11c+ macrophages in tubulointerstitial damage was investigated using SLE sera-treated monocytes and HK-2 cells. RESULTS: Urinary CD11c+ macrophages expressed pro-inflammatory cytokines, such as IL-6 and IL-1ß, and resembled infiltrated monocytes rather than tissue-resident macrophages with respect to surface marker expression. CD11c+ macrophages had high expression levels of the chemokine receptor CXCR3, which were correlated with cognate chemokine IP-10 expression in urinary tubular epithelial cells. When treated with sera from SLE patients, peripheral monocytes acquired the morphological and functional characteristics of urinary CD11c+ macrophages, which was blocked by DNase treatment. Finally, SLE sera-treated monocytes induced fibronectin expression, apoptosis and cell detachment in HK-2 cells via production of IL-6. CONCLUSION: CD11c+ macrophages may be involved in the pathogenesis of tubulointerstitial injury in LN.

HSP90 inhibitor (NVP-AUY922) enhances the anti-cancer effect of BCL-2 inhibitor (ABT-737) in small cell lung cancer expressing BCL-2.

Small cell lung cancer (SCLC) cannot be efficiently controlled using existing chemotherapy and radiotherapy approaches, indicating the need for new therapeutic strategies. Although ABT-737, a B-cell lymphoma-2 (BCL-2) inhibitor, exerts anticancer effects against BCL-2-expressing SCLC, monotherapy with ABT-737 is associated with limited clinical activity because of the development of resistance and toxicity. Here, we examined whether combination therapy with ABT-737 and heat shock protein 90 (HSP90) inhibitor NVP-AUY922 exerted synergistic anticancer effects on SCLC. We found that the combination of ABT-737 and NVP-AUY922 synergistically induced the apoptosis of BCL-2-expressing SCLC cells. NVP-AUY922 downregulated the expression of AKT and ERK, which activate MCL-1 to induce resistance against ABT-737. The synergistic effect was also partly due to blocking NF-κB activation, which induces anti-apoptosis protein expressions. However, interestingly, targeting BCL-2 and MCL-1 or BCL2 and NF-κB did not induce the cytotoxicity. In conclusion, our study showed that combination of BCL2 inhibitor with HSP90 inhibitor increased activity in in vitro and in vivo study in only BCL-2 expressing SCLC compared to either single BCL2 inhibitor or HSP inhibitor. The enhanced activity might be led by blocking several apoptotic pathways simultaneously rather than a specific pathway.

The HSP90 inhibitor, NVP-AUY922, attenuates intrinsic PI3K inhibitor resistance in KRAS-mutant non-small cell lung cancer.

More than 25% of non-small cell lung cancers (NSCLCs) carry mutations in KRAS, one of the most common oncogenic drivers in this disease. KRAS-mutant NSCLC responds poorly to currently available therapies; therefore, novel treatment strategies are needed. Here, we describe a particularly promising targeted therapeutic strategy against KRAS mutation-harboring NSCLC intrinsically resistant to treatment by PI3K inhibition. We found that intrinsic resistance to PI3K inhibition derived from RAF/MEK/ERK and RSK activation, bypassing blockage of the PI3K/AKT/mTOR pathway. The HSP90 inhibitor AUY922 suppressed both PI3K/AKT/mTOR and RAF/MEK/ERK signaling, rendering cells sensitive to a PI3K inhibitor (omipalisib, GSK458). Combining these two drugs achieved a synergistic effect, even using only sub-therapeutic concentrations. Dual inhibition of the HSP90 and PI3K signaling pathways with sub-therapeutic doses of these combined anticancer drugs may represent a potent treatment strategy for KRAS-mutant NSCLC with intrinsic resistance to PI3K inhibition.