cFLIP - An interacting partner and a novel substrate for pro-apoptotic serine protease HtrA2

Background

HtrA2, a pro-apoptotic protease, plays a crucial role in apoptosis by cleaving inhibitory and anti-apoptotic proteins by translocating from mitochondria to the cytosol. Prior studies in ischemic cells have indicated that cytosolic HtrA2 triggers cFLIP degradation, plausibly through direct interaction. In this study, we have characterized the cFLIP protein, validated its interaction with HtrA2, and demonstrated that cFLIP is also a substrate of HtrA2.

Methods

We have identified the probable cleavage sites of cFLIP through gel-based assays and mass spectrometric analysis of the cleaved fragments.

Results

Our findings shed light on a key protein-protein interaction involving pro-apoptotic HtrA2, confirming cFLIP as its interacting partner and substrate.

Conclusion

Understanding the nuances of HtrA2's interaction with cFLIP (a decoy protein of the initiator procaspase-8 in the extrinsic apoptotic pathway) and deciphering the cFLIP's mode of cleavage, would provide an excellent alternative to modulate the pathway for therapeutic benefits toward diseases like ischemia and cancer.

Acute aortic occlusion: A narrative review for emergency clinicians

INTRODUCTION

Acute aortic occlusion (AAO) is a rare but serious condition associated with significant morbidity and mortality.

OBJECTIVE

This review provides an emergency medicine focused evaluation of AAO, including presentation, assessment, and emergency department (ED) management based on current evidence.

DISCUSSION

AAO refers to obstruction of blood flow through the aorta due to either thrombosis or embolism. This condition primarily affects older adults ages 60-70 with cardiovascular comorbidities and most commonly presents with signs and symptoms of acute limb ischemia, though the gastrointestinal tract, kidneys, and spinal cord may be affected. The first line imaging modality includes computed tomography angiography of the chest, abdomen, and pelvis. ED resuscitative management consists of avoiding extremes of blood pressure or heart rate, maintaining normal oxygen saturation and euvolemic status, anticoagulation with heparin, and pain control. Emergent consultation with the vascular surgery specialist is recommended to establish a plan for restoration of perfusion to ischemic tissues via endovascular or open techniques. High rates of baseline comorbidities present in the affected population as well as ischemic and reperfusion injuries place AAO patients at high risk for complications in an immediate and delayed fashion after surgical management.

CONCLUSIONS

An understanding of AAO can assist emergency clinicians in diagnosing and managing this rare but devastating disease.

Challenging situation of coronary artery anomaly associated with ischemia and/or risk of sudden death

Coronary artery anomaly is known as one of the causes of angina pectoris and sudden death and is an important clinical entity that cannot be overlooked. The incidence of coronary artery anomalies is as low as 1%-2% of the general population, even when the various types are combined. Coronary anomalies are practically challenging when the left and right coronary ostium are not found around their normal positions during coronary angiography with a catheter. If there is atherosclerotic stenosis of the coronary artery with an anomaly and percutaneous coronary intervention (PCI) is required, the suitability of the guiding catheter at the entrance and the adequate back up force of the guiding catheter are issues. The level of PCI risk itself should also be considered on a case-by-case basis. In this case, emission computed tomography in the R-1 subtype single coronary artery proved that ischemia occurred in an area where the coronary artery was not visible to the naked eye. Meticulous follow-up would be crucial, because sudden death may occur in single coronary arteries. To prevent atherosclerosis with full efforts is also important, as the authors indicated admirably.

Safety and anatomical outcome analysis after flow diverter coverage of the anterior cerebral artery

OBJECTIVES

Few studies on ischemic complications and flow changes after a flow diverter covering the anterior cerebral artery. The purpose of the study was to explore the ischemic complications and anatomical alterations associated with the flow diverter after it covers the anterior cerebral artery.

MATERIALS AND METHODS

In this single-center study, patients treated with FD covering the anterior cerebral artery at the First Affiliated Hospital of Zhengzhou University were retrospectively collected. The primary endpoint was ischemic complications related to the anterior cerebral artery. Secondary endpoints were anatomical changes in the anterior cerebral artery postoperatively and at follow-up.

RESULTS

A total of 59 patients were included in this study. Four (6.8%) patients presented with ischemic stroke symptoms. Immediately after the procedure, complete occlusion of A1 and decreased blood flow was observed in 13 (22.0%) and 21 patients (35.6%), respectively. At follow-up, A1 artery was occluded in 34 patients (57.6%) and decreased blood flow was observed in 10 patients (16.9%). Symptoms of neurological deficits related to the anterior cerebral artery were not observed in all patients at follow-up.

CONCLUSION

Coverage of A1 is safe, with a low incidence of ischemic stroke, when using an FD to treat aneurysms. Risk of reduced perfusion of the anterior cerebral artery postoperatively even if the anterior communicating artery is open. In cases with A1 occlusion, the blood flow in the distal the anterior cerebral artery can be adequately compensated by opening the anterior communicating artery and good vascular anastomoses.

Ischemia does not provoke the full immune training repertoire in human cardiac fibroblasts

Trained immunity of monocytes, endothelial, and smooth muscle cells augments the cytokine response to secondary stimuli. Immune training is characterized by stabilization of hypoxia-inducible factor (HIF)-1α, mTOR activation, and aerobic glycolysis. Cardiac fibroblast (CF)-myofibroblast transition upon myocardial ischemia/reperfusion (I/R) features epigenetic and metabolic adaptations reminiscent of trained immunity. We assessed the impact of I/R on characteristics of immune training in human CF and mouse myocardium. I/R was simulated in vitro with transient metabolic inhibition. CF primed with simulated I/R or control buffer were 5 days later re-stimulated with Pam3CSK for 24 h. Mice underwent transient left anterior descending artery occlusion or sham operation with reperfusion for up to 5 days. HIF-regulated metabolic targets and cytokines were assessed by qPCR, immunoblot, and ELISA and glucose consumption, lactate release, and lactate dehydrogenase (LDH) by chromogenic assay. Simulated I/R increased HIF-1α stabilization, mTOR phosphorylation, glucose consumption, lactate production, and transcription of PFKB3 and F2RL3, a HIF-regulated target gene, in human CF. PGK1 and LDH mRNAs were suppressed. Intracellular LDH transiently increased after simulated I/R, and extracellular LDH showed sustained elevation. I/R priming increased abundance of pro-caspase-1, auto-cleaved active caspase-1, and the expression and secretion of interleukin (IL)-1β, but did not augment Pam3CSK-stimulated cytokine transcription or secretion. Myocardial I/R in vivo increased abundance of HIF-1 and the precursor and cleaved forms of caspase-1, caspase-11, and caspase-8, but not of LDH-A or phospho-mTOR. I/R partially reproduces features of immune training in human CF, specifically HIF-1α stabilization, aerobic glycolysis, mTOR phosphorylation, and PFKB3 transcription. I/R does not augment PGK1 or LDH expression or the cytokine response to Pam3CSK. Regulation of PAR4 and inflammasome caspases likely occurs independently of an immune training repertoire.

Estrogen's sex-specific effects on ischemic cell death and estrogen receptor mRNA expression in rat cortical organotypic explants

Estrogens, such as the biologically active 17-β estradiol (E2), regulate not only reproductive behaviors in adults, but also influence neurodevelopment and neuroprotection in both females and males. E2, contingent upon the timing and concentration of the therapy, is neuroprotective in female and male rodent models of stroke. In Vivo studies suggest that E2 may partially mediate this neuroprotection, particularly in the cortex, via ERα. In Vitro studies, utilizing a chemically induced ischemic injury in cortical explants from both sexes, suggest that ERα or ERβ signaling is needed to mediate the E2 protection. Since we know that the timing and concentration of E2 therapy may be sex-specific, we examined if E2 (1 nM) mediates neuroprotection when female and male cortical explants are separately isolated from postnatal day (PND) 3-4 rat. Changes in basal levels ERα, ERβ, and AR mRNA expression are compared across early post-natal development in the intact cortex and the corresponding days in vitro (DIV) for cortical explants. Following ischemic injury at 7 DIV, cell death and ERα, ERβ and AR mRNA expression was compared in female and male cortical explants. We provide evidence that E2-mediated protection is maintained in isolated cortical explants from females, but not male rats. In female cortical explants, the E2-mediated protection at 24 h occurs secondarily to a blunted transient increase in ERα mRNA at 12 h. These results suggest that cortical E2-mediated protection is influenced by sex and supports data to differentially treat females and males following ischemic injury.

Myocardial motion in acute ischemia: revealing invisible deformation by echocardiography

Echocardiography has been used clinically to assess regional myocardial wall motion for the diagnosis of acute myocardial ischemia or stress-induced ischemia, but it is often difficult to distinguish hypokinetic motion from normal motion. Myocardial wall motion is affected by loading conditions as well as intrinsic contractility, making it challenging to define a normal range of wall motion. Therefore, hypokinesis is usually diagnosed by comparing target areas with other areas of myocardium considered normal (relative hypokinesis). Myocardial strain analysis by tissue Doppler echocardiography and speckle-tracking echocardiography has enabled objective and quantitative evaluation of regional myocardial wall motion. Peak systolic strain decreases during acute ischemia, but subtle and invisible myocardial motion, such as early systolic lengthening (ESL) and postsystolic shortening (PSS), also occurs, and the analysis of these subtle motions can improve the diagnostic accuracy of ischemia. However, the diagnosis of ischemic myocardium by strain analysis is not widely performed in clinical practice at this time due to several limitations. This article reviews the features of myocardial motion during acute ischemia, the mechanisms of ESL and PSS, the diagnosis of ischemic myocardium using strain analysis, and current approaches and future challenges to overcome the limitations in the detection of relative hypokinesis. This article also explains the use of ESL and PSS to detect myocardial ischemic memory that remains after brief ischemia.

Do platelets protect the heart against ischemia/reperfusion injury or exacerbate cardiac ischemia/reperfusion injury? The role of PDGF, VEGF, and PAF

BACKGROUND

Acute myocardial infarction (AMI) is one of the main causes of death. It is quite obvious that there is an urgent need to develop new approaches for treatment of AMI.

OBJECTIVE

This review analyzes data on the role of platelets in the regulation of cardiac tolerance to ischemia/reperfusion (I/R).

METHODS

It was performed a search of topical articles using PubMed databases.

FINDINGS

Platelets activated by a cholesterol-enriched diet, thrombin, and myocardial ischemia exacerbate I/R injury of the heart. The P2Y12 receptor antagonists, remote ischemic postconditioning and conditioning alter the properties of platelets. Platelets acquire the ability to increase cardiac tolerance to I/R. Platelet-derived growth factors (PDGFs) increase tolerance of cardiomyocytes and endothelial cells to I/R. PDGF receptors (PDGFRs) were found in cardiomyocytes and endothelial cells. PDGFs decrease infarct size and partially abrogate adverse postinfarction remodeling. Protein kinase C, phosphoinositide 3-kinase, and Akt involved in the cytoprotective effect of PDGFs. Vascular endothelial growth factor increased cardiac tolerance to I/R and alleviated adverse postinfarction remodeling. The platelet-activating factor (PAF) receptor inhibitors increase cardiac tolerance to I/R in vivo. PAF enhances cardiac tolerance to I/R in vitro. It is possible that PAF receptor inhibitors could protect the heart by blocking PAF receptor localized outside the heart. PAF protects the heart through activation of PAF receptor localized in cardiomyocytes or endothelial cells. Reactive oxygen species and kinases are involved in the cardioprotective effect of PAF.

CONCLUSION

Platelets play an important role in the regulation of cardiac tolerance to I/R.

Natural course of hemodynamically stable hemispheres contralateral to operated hemispheres in adult patients with ischemic moyamoya diseases

The necessity of bilateral bypass in adult moyamoya disease (MMD) remains unclear despite its recommendation for pediatric and hemorrhagic cases. We aimed to investigate the natural course of hemodynamically stable unoperated hemispheres after bypass surgery for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD. Among 288 patients, the mean age at the first operation of the unstable hemispheres was 40.8 ± 12.2 years. The mean follow-up period was 62.9 ± 46.5 months. 45 patients (15.6%) experienced stroke events in the unoperated hemisphere, consisting of hemorrhagic stroke in 8 (2.8%) and ischemic stroke in 37 (12.8%), including progressive transient ischemic attack in 25 (8.7%) and infarction in 12 (4.2%). Among them, 39 patients (13.5%) underwent bypass surgery. The annual risk of total stroke is 3.0%/patient-year, with 2.5% for ischemic stroke and 0.5% for hemorrhagic stroke. The 5- and 10-year cumulative risks of ischemic stroke were 13.4% and 18.3%, respectively, and those of hemorrhagic stroke were each 3.2%. The natural course of hemodynamically stable hemispheres contralateral to the operated ones appeared fairly good. Additional bypass surgery on the unoperated hemispheres should be considered for symptomatic and hemodynamically unstable hemispheres in adult patients with ischemic MMD during the follow-up.

Outcomes Associated With Aortic Balloon Occlusion Time in Patients With Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta

INTRODUCTION

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has the potential to cause clinically relevant systemic ischemic burden with long durations of aortic occlusion (AO). We aimed to examine the association between balloon occlusion time and clinical complications and mortality outcomes in patients undergoing zone 1 REBOA.

METHODS

A retrospective cohort analysis of American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acuteregistry patients with Zone 1 REBOA between 2013 and 2022 was performed. Patients with cardiopulmonary resuscitation on arrival or who did not survive past the emergency department were excluded. Total AO times were categorized as follows: <15 min, 15-30 min, 31-60 min, and >60 min. Clinical and procedural variables and in-hospital outcomes were compared across groups using bivariate and multivariate regression analyses.

RESULTS

There were 327 cases meeting inclusion criteria (n = 51 < 15 min, 83 15-30 min, 98 31-60 min, and 95 > 60 min, respectively). AO >60 min had higher admission lactate (8 ± 6; P = 0.004) compared to all other time groups, but injury severity score, heart rate, and systolic blood pressure were similar. Group average times from admission to definitive hemorrhage control ranged from 82 to 103 min and were similar across groups (85 min in AO >60 group). Longer AO times were associated with greater red blood cell, fresh frozen plasma transfusions (P < 0.001), and vasopressor use (P = 0.001). Mortality was greatest in the >60 min group (73%) versus the <15 min, 15-30 min, and 31-60 min groups (53%, 43%, and 45%, P < 0.001). With adjustment for injury severity score, systolic blood pressure, and lactate, AO >60 min had greater mortality (OR 3.7, 95% CI 1.6-9.4; P < 0.001) than other AO duration groups. Among 153 survivors, AO >60 min had a higher rate of multiple organ failure (15.4%) compared to the other AO durations (0%, 0%, and 4%, P = 0.02). There were no differences in amputation rates (0.7%) or spinal cord ischemia (1.4%). acute kidney injury was seen in 41% of >60 min versus 21%, 27%, and 33%, P = 0.42.

CONCLUSIONS

Though greater preocclusion physiologic injury may have been present, REBOA-induced ischemic insult was correlated with poor patient outcomes, specifically, REBOA inflation time >60 min had higher rates of mortality and multiple organ failure. Minimizing AO duration should be prioritized, and AO should not delay achieving definitive hemostasis. Partial REBOA may be a solution to extend safe AO time and deserves further study.

End-to-end revascularization between the occipital Artery(OA) and the p1 segment of posterior inferior cerebellar Artery(PICA) for a patient with posterior circulation ischemia via a far-lateral approach:2-Dimensional Operative video

Vertebral artery （VA）Aneurysms involving the origin of the posterior inferior cerebellar artery (PICA) ,occasionally, induce cerebellum and brainstem infarction due to intraluminal thrombus and calcific VA stenosis. At times, vessel occlusion and revascularization is necessary for successful obliteration of these aneurysms.2 The occipital artery (OA) is often the preferred donor graft for lesions of the posterior fossa. Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops , aberrant anatomy or p3 multiple perforators is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead. This video captures the dissection of the OA using an orientational anterograde harvesting technique and the end-to-end anastomosis of the OA to the PICA at the p1 segment. This was performed in a 56-year-old man who presented with posterior circulation ischemia from a fusiform aneurysm with calcific vertebral artery stenosis located at the origin of the right PICA. The patient tolerated the procedure well and suffered no major complications related to the operation. He did experience some mild, posterior neck rigidity at the time of his 6-month follow-up, likely due to nerve injury that occurred while harvesting the OA. Overall, the patient remains in good neurologic status 1 year after the operation. The operation proved the feasibility of end-to-end bypass in OA-p1 PICA.

Reactive oxygen species generation by reverse electron transfer at mitochondrial complex I under simulated early reperfusion conditions

Ischemic tissues accumulate succinate, which is rapidly oxidized upon reperfusion, driving a burst of mitochondrial reactive oxygen species (ROS) generation that triggers cell death. In isolated mitochondria with succinate as the sole metabolic substrate under non-phosphorylating conditions, 90 % of ROS generation is from reverse electron transfer (RET) at the Q site of respiratory complex I (Cx-I). Together, these observations suggest Cx-I RET is the source of pathologic ROS in reperfusion injury. However, numerous factors present in early reperfusion may impact Cx-I RET, including: (i) High [NADH]; (ii) High [lactate]; (iii) Mildly acidic pH; (iv) Defined ATP/ADP ratios; (v) Presence of the nucleosides adenosine and inosine; and (vi) Defined free [Ca2+]. Herein, experiments with mouse cardiac mitochondria revealed that under simulated early reperfusion conditions including these factors, total mitochondrial ROS generation was only 56 ± 17 % of that seen with succinate alone (mean ± 95 % confidence intervals). Of this ROS, only 52 ± 20 % was assignable to Cx-I RET. A further 14 ± 7 % could be assigned to complex III, with the remainder (34 ± 11 %) likely originating from other ROS sources upstream of the Cx-I Q site. Together, these data suggest the relative contribution of Cx-I RET ROS to reperfusion injury may be overestimated, and other ROS sources may contribute a significant fraction of ROS in early reperfusion.

The significance of initial lactate levels in emergency department presentations of abdominal wall hernia

INTRODUCTION

Abdominal wall hernias are a frequent cause of abdominal pain-related emergency department visits. Our study aimed to establish the connection between lactate levels and patient outcomes in those with abdominal pain due to abdominal wall hernias.

MATERIALS AND METHODS

Our research followed a retrospective, observational, and descriptive approach and two center. We included patients who visited the emergency department for abdominal pain and were confirmed to have abdominal wall hernias through ultrasound.

RESULTS

We enrolled 493 patients meeting the criteria. Median age was 65 years, with 54% (n = 266) being male. Regarding outcomes, 40.5% (n = 200) were hospitalized, 27.7% (n = 137) underwent surgery, and 7.9% (n = 39) underwent bowel resection. Mortality rate during hernia-related hospital admission was 0.6% (n = 3). For hospitalized patients, there were significant differences in white blood cell count, neutrophil count and percentage, platelet count, lymphocyte count, and percentage (p < 0.05). Patients undergoing resection showed significant differences in neutrophil count, neutrophil percentage, lymphocyte count, and lymphocyte percentage (p < 0.05). Lactate levels were statistically significant in all patient groups requiring hospitalization, surgery, and resection (p < 0.05). Sensitivity and specificity of lactate test results indicated in patients undergoing bowel resection, lactate values ≥1.96 mmol/L had a specificity of 64%, sensitivity of 71%, and a negative predictive value of 96% (p < 0.05).

CONCLUSION

Low lactate levels in patients presenting to the emergency department with abdominal pain caused by abdominal wall hernias have a high negative predictive value for excluding strangulation and the need for bowel resection. Therefore, we recommend the use of lactate as an additional diagnostic tool in emergency department presentations related to abdominal wall hernias.

A transferable in-silico augmented ischemic model for virtual myocardial perfusion imaging and myocardial infarction detection

This paper proposes an innovative approach to generate a generalized myocardial ischemia database by modeling the virtual electrophysiology of the heart and the 12-lead electrocardiography projected by the in-silico model can serve as a ready-to-use database for automatic myocardial infarction/ischemia (MI) localization and classification. Although the virtual heart can be created by an established technique combining the cell model with personalized heart geometry to observe the spatial propagation of depolarization and repolarization waves, we developed a strategy based on the clinical pathophysiology of MI to generate a heterogeneous database with a generic heart while maintaining clinical relevance and reduced computational complexity. First, the virtual heart is simplified into 11 regions that match the types and locations, which can be diagnosed by 12-lead ECG; the major arteries were divided into 3-5 segments from the upstream to the downstream based on the general anatomy. Second, the stenosis or infarction of the major or minor coronary artery branches can cause different perfusion drops and infarct sizes. We simulated the ischemic sites in different branches of the arteries by meandering the infarction location to elaborate on possible ECG representations, which alters the infraction's size and changes the transmembrane potential (TMP) of the myocytes associated with different levels of perfusion drop. A total of 8190 different case combinations of cardiac potentials with ischemia and MI were simulated, and the corresponding ECGs were generated by forward calculations. Finally, we trained and validated our in-silico database with a sparse representation classification (SRC) and tested the transferability of the model on the real-world Physikalisch Technische Bundesanstalt (PTB) database. The overall accuracies for localizing the MI region on the PTB data achieved 0.86, which is only 2% drop compared to that derived from the simulated database (0.88). In summary, we have shown a proof-of-concept for transferring an in-silico model to real-world database to compensate for insufficient data.

Cerebral small vessel disease and stroke: Linked by stroke aetiology, but not stroke lesion location or size

BACKGROUND

Cerebral small vessel disease (SVD) has previously been associated with worse stroke outcome, vascular dementia, and specific post-stroke cognitive deficits. The underlying causal mechanisms of these associations are not yet fully understood. We investigated whether a relationship between SVD and certain stroke aetiologies or a specific stroke lesion anatomy provides a potential explanation.

METHODS

In a retrospective observational study, we examined 859 patients with first-ever, non-SVD anterior circulation ischemic stroke (age = 69.0±15.2). We evaluated MRI imaging markers to assess an SVD burden score and mapped stroke lesions on diffusion-weighted MRI. We investigated the association of SVD burden with i) stroke aetiology, and ii) lesion anatomy using topographical statistical mapping.

RESULTS

With increasing SVD burden, stroke of cardioembolic aetiology was more frequent (ρ = 0.175; 95 %-CI = 0.103;0.244), whereas cervical artery dissection (ρ = -0.143; 95 %-CI = -0.198;-0.087) and a patent foramen ovale (ρ = -0.165; 95 %-CI = -0.220;-0.104) were less frequent stroke etiologies. However, no significant associations between SVD burden and stroke aetiology remained after additionally controlling for age (all p>0.125). Lesion-symptom-mapping and Bayesian statistics showed that SVD burden was not associated with a specific stroke lesion anatomy or size.

CONCLUSIONS

In patients with a high burden of SVD, non-SVD stroke is more likely to be caused by cardioembolic aetiology. The common risk factor of advanced age may link both pathologies and explain some of the existing associations between SVD and stroke. The SVD burden is not related to a specific stroke lesion location.

Dataset on stroke infarct volume in rodents: A comparison of MRI and histological methods

This dataset offers images of mouse brains impacted by photothrombotic stroke in the sensorimotor cortex published by Weber et al. NeuroImage (2024). Data is gathered using two primary techniques: (1) whole-brain ex-vivo magnetic resonance imaging (MRI) and (2) 40 µm thick coronal histological sections that undergo immunofluorescence staining with NeuroTrace. Infarct areas and volumes are assessed through MRI at two distinct time frames-three days (acute) and 28 days (chronic) following photothrombotic stroke induction. Subsequently, the brains are sectioned into 40 µm thick coronal slices, stained with NeuroTrace, and imaged as whole sections. The dataset holds considerable value for reuse, particularly for researchers focused on stroke volume estimation methods as well as those interested in comparing the efficacy of MRI and histological techniques.

Strengthening the basics: acids and bases influence vascular structure and function, tissue perfusion, blood pressure, and human cardiovascular disease

Acids and their conjugate bases accumulate in or dissipate from the interstitial space when tissue perfusion does not match the metabolic demand. Extracellular acidosis dilates most arterial beds, but associated acid-base disturbances-e.g., intracellular acidification and decreases in HCO3- concentration-can also elicit pro-contractile influences that diminish vasodilation and even dominate in some vascular beds to cause vasoconstriction. The ensemble activities of the acid-base-sensitive reactions in vascular smooth muscle and endothelial cells optimize vascular resistance for blood pressure control and direct the perfusion towards active tissue. In this review, we describe the mechanisms of intracellular pH regulation in the vascular wall and discuss how vascular smooth muscle and endothelial cells sense acid-base disturbances. We further deliberate on the functional effects of local acid-base disturbances and their integrated cardiovascular consequences under physiological and pathophysiological conditions. Finally, we address how mutations and polymorphisms in the molecular machinery that regulates pH locally and senses acid-base disturbances in the vascular wall can result in cardiovascular disease. Based on the emerging molecular insight, we propose that targeting local pH-dependent effectors-rather than systemic acid-base disturbances-has therapeutic potential to interfere with the progression and reduce the severity of cardiovascular disease.

GCN5L1-mediated acetylation prevents Rictor degradation in cardiac cells after hypoxic stress

Cardiomyocyte apoptosis and cardiac fibrosis are the leading causes of mortality in patients with ischemic heart disease. As such, these processes represent potential therapeutic targets to treat heart failure resulting from ischemic insult. We previously demonstrated that the mitochondrial acetyltransferase protein GCN5L1 regulates cardiomyocyte cytoprotective signaling in ischemia-reperfusion injury in vivo and hypoxia-reoxygenation injury in vitro. The current study investigated the mechanism underlying GCN5L1-mediated regulation of the Akt/mTORC2 cardioprotective signaling pathway. Rictor protein levels in cardiac tissues from human ischemic heart disease patients were significantly decreased relative to non-ischemic controls. Rictor protein levels were similarly decreased in cardiac AC16 cells following hypoxic stress, while mRNA levels remained unchanged. The reduction in Rictor protein levels after hypoxia was enhanced by the knockdown of GCN5L1, and was blocked by GCN5L1 overexpression. These findings correlated with changes in Rictor lysine acetylation, which were mediated by GCN5L1 acetyltransferase activity. Rictor degradation was regulated by proteasomal activity, which was antagonized by increased Rictor acetylation. Finally, we found that GCN5L1 knockdown restricted cytoprotective Akt signaling, in conjunction with decreased mTOR abundance and activity. In summary, these studies suggest that GCN5L1 promotes cardioprotective Akt/mTORC2 signaling by maintaining Rictor protein levels through enhanced lysine acetylation.

The paradox of tPA in ischemic stroke: tPA knockdown following recanalization improves functional and histological outcomes

Previous studies have demonstrated that endogenous tissue-type plasminogen activator (tPA) is upregulated in the brain after an acute ischemic stroke (AIS). While mixed results were observed in genetic models, the pharmacological inhibition of endogenous tPA showed beneficial effects. Treatment with exogenous recombinant tPA exacerbated brain damage in rodent models of stroke. Despite the detrimental effects of tPA in ischemic stroke, recombinant tPA is administered to AIS patients to recanalize the occluded blood vessels because the benefits of its administration outweigh the risks associated with tPA upregulation and increased activity. We hypothesized that tPA knockdown following recanalization would ameliorate sensorimotor deficits and reduce brain injury. Young male and female rats (2-3 months old) were subjected to transient focal cerebral ischemia by occlusion of the right middle cerebral artery. Shortly after reperfusion, rats from appropriate cohorts were administered a nanoparticle formulation containing tPA shRNA or control shRNA plasmids (1 mg/kg) intravenously via the tail vein. Infarct volume during acute and chronic phases, expression of matrix metalloproteinases (MMPs) 1, 3, and 9, enlargement of cerebral ventricle volume, and white matter damage were all reduced by shRNA-mediated gene silencing of tPA following reperfusion. Additionally, recovery of somatosensory and motor functions was improved. In conclusion, our results provide evidence that reducing endogenous tPA following recanalization improves functional outcomes and reduces post-stroke brain damage.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Renal rescue after inadvertent coverage during endovascular aneurysm repair

Inadvertent renal artery obstruction during endovascular aortic repair is a rare but serious complication. In such cases, endovascular recanalization is typically attempted; however, it can be challenging, leading to many severe cases. Moreover, if treatment is delayed, the blockage time of the renal artery poses a problem. We encountered a case of inadvertent renal artery occlusion during endovascular aortic repair. In this case, bailout stent implantation through a gap between the aortic wall and a stent graft made by a balloon catheter was effective in reducing the renal ischemia time and facilitating the revascularization procedure.

Cardiac MRI after Sudden Cardiac Arrest: A Systematic Review

Purpose To perform a systematic review to assess the diagnostic and prognostic value of cardiac MRI after sudden cardiac arrest (SCA). Materials and Methods PubMed and Cochrane Library databases were systematically searched for studies investigating cardiac MRI after SCA in adult patients (≥18 years of age). The time frame of the encompassed studies spans from January 2012 to January 2023. The study protocol was preregistered in OSF Registries (www.osf.io/nxaev), and the systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was evaluated using the Newcastle-Ottawa quality assessment scale. Results Fourteen studies involving 1367 individuals, 1257 (91.9%) of whom underwent cardiac MRI, were included. Inconsistent findings were reported on the diagnostic value of cardiac MRI-specific findings. The included studies demonstrated the following main findings: (a) cardiac MRI led to a new or alternative diagnosis in patients with SCA; (b) cardiac MRI identified pathologic or arrhythmogenic substrates; (c) cardiac MRI helped detect myocardial edema (potentially reversible); (d) cardiac MRI provided evidence for the occurrence of adverse events; and (e) functional markers or ventricular dimensions were considered prognostically relevant in a few studies. Relevant challenges in this systematic review were the lack of comparators and reference standards relative to cardiac MRI as the index test and patient selection bias. Conclusion Cardiac MRI following SCA can contribute to the diagnostic process and offer supplementary information essential for treatment planning. Limitations of the review include studies with insufficient comparators and potential bias in patient selection. Systematic review registration link: osf.io/nxaev Keywords: Cardiac MRI, Cardiovascular Disease, Cardiomyopathy, Ischemia, Myocardial Edema, Sudden Cardiac Arrest © RSNA, 2024.

Cardioprotective effect of antioxidant combination therapy: A highlight on MitoQ plus alpha-lipoic acid beneficial impact on myocardial ischemia-reperfusion injury in aged rats

Objective

(s): Considering the poor prognosis of ischemic heart disease and the diminished effectiveness of cardioprotective interventions in the elderly, it becomes necessary to investigate the interaction of aging with protection during myocardial ischemia/reperfusion injury (IRI). This study was conducted to assess the impact of mitoquinone (MitoQ) and alpha-lipoic acid (ALA) preconditioning on cardioprotection following IRI in aged rats.

Methods

Fifty aged male Wistar rats (22-24 months old) were divided into five groups including Sham, IR, and treatment groups receiving ALA and/or MitoQ. Treatment groups were received 100 mg/kg/day ALA by oral gavage and/or 10 mg/kg/day MitoQ by intraperitoneal injection for 14 consecutive days. An in vivo model of myocardial IRI was established through ligation of coronary artery for 30 min and it's reopening for 24 h. The left ventricles were removed at the end of reperfusion to assess oxidative stress indicators, mitochondrial function, and expression of mitochondrial dynamic genes. Myocardial infarct size (IS), hemodynamic parameters, and serum lactate dehydrogenase (LDH) level were also measured.

Results

Combination of MitoQ and ALA reduced oxidative stress, LDH level, and IS in aged hearts subjected to IRI. It also enhanced mitochondrial function and upregulated Mfn1, Mfn2, and Foxo1 and downregulated Drp1 and Fis1 gene expression. Co-administration of MitoQ and ALA partially restored IRI-induced hemodynamic changes to normal state. In all measured parameters, the effect of combined treatment was greater than monotherapies.

Conclusion

The combination therapy of MitoQ and ALA demonstrated considerable therapeutic potential in protecting the aging heart against IRI by improving oxidative stress, mitochondrial function, and dynamics in aged rats.

External border zone may be correlated with radiation necrosis after radiosurgery in metastatic brain tumor

BACKGROUND

Radiation necrosis (RN) after stereotactic radiosurgery (SRS) in brain metastases has been extensively evaluated, and RN is correlated with various risk factors. However, no study comprehensively analyzed the correlation between RN and the border zones of the brain that are vulnerable to ischemia. We hypothesized that patients with tumors in the border zone are at high risk of RN. Hence, the current study aimed to assess the correlation between border zone lesions and RN, with consideration of other predetermined factors.

METHODS

This retrospective study included 117 patients with 290 lesions who underwent Gamma Knife® stereotactic radiosurgery (SRS). Radiological and clinical analyses were performed to identify factors possibly correlated with RN. Notably, the lesion location was classified into two groups (border zone and non-border zone) based on the blood supply.

RESULTS

In total, 22 (18.8%) patients with 22 (7.5%) lesions developed RN. Univariate analysis revealed a significant correlation between RN and external border zone lesions, second course of SRS administered at the same site of the previous SRS, prescribed dose, and tumor volume. Multivariate analysis showed that border zone lesions, second course of SRS at the same site of the previous SRS, and tumor volume were significantly correlated with RN.

CONCLUSIONS

Patients with tumors in the border zone are at high risk of RN. The potential risks of RN can be attributed hypothetically to hypoperfusion. Hence, the association between RN and border zone lesions seems reasonable.

High fibrinogen-prealbumin ratio (FPR) predicts stroke-associated pneumonia

OBJECTIVES

Although numerous factors had been found to be associated with stroke-associated pneumonia (SAP), the underlying mechanisms of SAP remain unclear. Fibrinogen-prealbumin ratio (FPR) is a novel indicator that could balance the effects of inflammation and nutrition, which might reflect biological status of patients more comprehensively than other biomarkers. To date, FPR has not been explored in acute ischemic stroke patients. This study aims to explore the relationship between FPR and SAP.

MATERIALS AND METHODS

900 stroke patients participated in this retrospective study and 146 healthy controls were recruited. Fibrinogen and prealbumin were measured within 24 hours on admission. FPR was calculated after dividing fibrinogen (g/L) by prealbumin (mg/L) × 1000. SAP was defined according to the modified Centers for Disease Control criteria.

RESULTS

121 patients were diagnosed with SAP. Log10FPR was higher in stroke patients than healthy controls. In logistic regression analysis, log10FPR was independently associated with SAP (OR 15.568; 95% CI: 3.287-73.732; P=0.001). Moreover, after using ROC curve, the predictive power of "current standard"(defined as A2DS2 plus leukocyte count and log10hs-CRP) plus log10FPR (0.832[0.804-0.857]) was higher than "current standard" (0.811[0.782-0.837], P=0.0944) and A2DS2 plus log10FPR (0.801[0.772-0.828], P=0.0316). No significant difference was found between the predictive power of A2DS2 plus log10FPR and "current standard" (P =0.6342).

CONCLUSION

Higher FPR was observed in stroke patients compared with healthy controls and was significantly associated with SAP. FPR might provide useful clues for timely identification and treatment of SAP.

Simulating Cerebral Edema and Ischemia After Traumatic Acute Subdural Hematoma Using Triphasic Swelling Biomechanics

Poor outcome following traumatic acute subdural hematoma (ASDH) is associated with the severity of the primary injury and secondary injury including cerebral edema and ischemia. However, the underlying secondary injury mechanism contributing to elevated intracranial pressure (ICP) and high mortality rate remains unclear. Cerebral edema occurs in response to the exposure of the intracellular fixed charge density (FCD) after cell death, causing ICP to increase. The increased ICP from swollen tissue compresses blood vessels in adjacent tissue, restricting blood flow and leading to ischemic damage. We hypothesize that the mass occupying effect of ASDH exacerbates the ischemic injury, leading to ICP elevation, which is an indicator of high mortality rate in the clinic. Using FEBio (febio.org) and triphasic swelling biomechanics, this study modeled clinically relevant ASDHs and simulated post-traumatic brain swelling and ischemia to predict ICP. Results showed that common convexity ASDH significantly increased ICP by exacerbating ischemic injury, and surgical removal of the convexity ASDH may control ICP by preventing ischemia progression. However, in cases where the primary injury is very severe, surgical intervention alone may not effectively decrease ICP, as the contribution of the hematoma to the elevated ICP is insignificant. In addition, interhemispheric ASDH, located between the cerebral hemispheres, does not significantly exacerbate ischemia, supporting the conservative surgical management generally recommended for interhemispheric ASDH. The joint effect of the mass occupying effect of the blood clot and resulting ischemia contributes to elevated ICP which may increase mortality. Our novel approach may improve the fidelity of predicting patient outcome after motor vehicle crashes and traumatic brain injuries due to other causes.

LncRNA PART1 Attenuates Myocardial Ischemia-Reperfusion Injury by Regulating TFAP2C/DUSP5 Axis via miR-302a-3p

BACKGROUND AND OBJECTIVES

Myocardial ischemia-reperfusion injury (MIRI) refers to the damage of cardiac function caused by restoration of blood flow perfusion in ischemic myocardium. However, long non-coding RNA prostate androgen regulated transcript 1 (PART1)'s role in MIRI remain unclear.

METHODS

Immunofluorescence detected LC3 expression. Intermolecular relationships were verified by dual luciferase reporter assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry and transferase-mediated dUTP nick-end labeling (TUNEL) assays analyzed cell viability and apoptosis. The release of lactate dehydrogenase was tested via enzyme-linked immunosorbent assay (ELISA). Left anterior descending coronary artery surgery induced a MIRI mouse model. Infarct area was detected by 2,3,5-triphenyltetrazolium chloride staining. Hematoxylin and eosin staining examined myocardial injury. ELISA evaluated myocardial marker (creatine kinase MB) level.

RESULTS

PART1 was decreased in H/R induced AC16 cells and MIRI mice. PART1 upregulation attenuated the increased levels of Bax, beclin-1 and the ratio of LC3II/I, and enhanced the decrease of Bcl-2 and p62 expression in H/R-treated cells. PART1 upregulation alleviated H/R-triggered autophagy and apoptosis via miR-302a-3p. Mechanically, PART1 targeted miR-302a-3p to upregulate transcription factor activating enhancer-binding protein 2C (TFAP2C). TFAP2C silencing reversed the protected effects of miR-302a-3p inhibitor on H/R treated AC16 cells. We further established TFAP2C combined to dual-specificity phosphatase 5 (DUSP5) promoter and activated DUSP5. TFAP2C upregulation suppressed H/R-stimulated autophagy and apoptosis through upregulating DUSP5. Overexpressed PART1 reduced myocardial infarction area and attenuated MIRI in mice.

CONCLUSION

PART1 improved the autophagy and apoptosis in H/R-exposed AC16 cells through miR-302a-3p/TFAP2C/DUSP5 axis, which might provide novel targets for MIRI treatment.

Mechanisms of hypoxia and contractile dysfunction in ischemia/reperfusion in hiPSC cardiomyocytes: an in silico study

Interconnected mechanisms of ischemia-reperfusion (I-R) has increased the interest in I-R in vitro experiments using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We developed a whole-cell computational model of hiPSC-CMs including the electromechanics, a metabolite-sensitive sarcoplasmic reticulum Ca2+-ATPase (SERCA), and an oxygen dynamics formulation to investigate I-R mechanisms. Moreover, we simulated the effect and action mechanism of Levosimendan (LEVO) that recently showed promising anti-arrhythmic effects in hiPSC-CMs in hypoxia. The model was validated using hiPSC-CM and in vitro animal data. The role of SERCA in causing relaxation dysfunction in I-R was anticipated to be comparable to its function in sepsis-induced heart failure. Drug simulations showed that LEVO counteracts the relaxation dysfunction by utilizing a particular Ca2+ sensitizing mechanism involving Ca2+ bound troponin C and Ca2+ flux to the myofilament, rather than inhibiting SERCA phosphorylation. The model demonstrates extensive characterization and promise for drug development, making it suitable for evaluating ischemia-reperfusion therapy strategies based on the changing levels of cardiac metabolites, oxygen, and molecular pathways.

Clinical characteristics, Risk factors, and outcomes of Posterior circulation stroke: A retrospective study between younger and older adults in Saudi Arabia

INTRODUCTION

Posterior circulation stroke (PCS) may be less prevalent than its anterior counterpart but contributes to substantial morbidity and mortality. The aim was to characterize PCS's demographics, clinical presentation, management, and outcomes between younger and older adults in Saudi Arabia.

METHODS

This retrospective cohort study was conducted at two tertiary medical centers in Saudi Arabia between March 2016 and December 2020. All patients who presented with symptoms of posterior circulation stroke and had positive brain imaging were included.

RESULTS

The study involved 160 posterior circulation stroke patients, stratified into two age groups: 71 patients aged 18-59 years and 89 patients aged 60 years and above. The mean age of the entire cohort was 60.9 years, and 77 % were males. Hypertension was more prevalent in the older age group (88 % vs. 69 %, p=0.005), and smoking was significantly higher among younger patients (38 % vs. 15 %; p=0.0009). Only 22.4 % received thrombolysis and/or thrombectomy. Most strokes involved the posterior cerebral artery (45.6 %). Large artery atherosclerosis was the most common subtype. At discharge, younger patients had higher NIHSS compared to older patients.

CONCLUSION

Our investigation of 160 PCS patients in Saudi Arabia uncovers notable trends: a mere 22.4 % received thrombolysis and/or thrombectomy and a significant prevalence of posterior cerebral artery involvement due to large artery atherosclerosis. The study further reveals younger patients disproportionately had severe outcomes. Highlighting the need for improved stroke care and heightened awareness, this research contributes vital data to an underexplored domain, urging further study to optimize care and understand PCS dynamics in Saudi Arabia.

Neuroprotective effect of, a flavonoid, sudachitin in mice stroke model

A flavonoid, sudachitin, has been reported to show some beneficial health effects, including as an anti-inflammatory in LPS-stimulated macrophages, as well as improving glucose and lipid metabolism in mice fed a high-fat diet. In this study, we investigated the neuroprotective effect of sudachitin in the transient middle cerebral artery occlusion (tMCAO) mouse model. After daily pre-treatment of vehicle or sudachitin (5 or 50 mg/kg) for 14 days, mice (n = 76) were subjected to a sham operation or tMCAO for 45 min, and on the following days, they were treated daily with vehicle or sudachitin. The administration of sudachitin significantly reduced (p < 0.05) cerebral infarct volume and attenuated apoptosis, 5 days after tMCAO. Neurological impairment improved, the expression of an oxidative stress marker, 4-HNE, decreased, and the Sirt1/PGC-1α pathway was activated 5 days after tMCAO in the sudachitin-treated group. This is the first report to demonstrate the neuroprotective effect of sudachitin in cerebral ischemia/reperfusion injury mice model, probably by activating the Sirt1/PGC-1α axis. Sudachitin may be a promising supplement or therapeutic agent for reducing injury caused by ischemic strokes.

The role of dorsolateral striatum in the effects of deep cerebellar stimulation-mediated motor recovery following ischemic stroke in rodents

Despite great advances in acute care and rehabilitation, stroke remains the leading cause of motor impairment in the industrialized world. We have developed a deep brain stimulation (DBS)-based approach for post-stroke rehabilitation that has shown reproducible effects in rodent models and has been recently translated to humans. Mechanisms underlying the rehabilitative effects of this novel therapy have been largely focused on the ipsilesional cortex, including cortical reorganization, synaptogenesis, neurogenesis and greater expression of markers of long-term potentiation. The role of subcortical structures on its therapeutic benefits, particularly the striatum, remain unclear. In this study, we compared the motor rehabilitative effects of deep cerebellar stimulation in two rodent models of cerebral ischemia: a) cortical ischemia; and b) combined striatal and cortical ischemia. All animals underwent the same procedures, including implantation of the electrodes and tethered connections for stimulation. Both experimental groups received four weeks of continuous lateral cerebellar nucleus (LCN) DBS and each was paired with a no stimulation, sham, group. Fine motor function was indexed using the pasta matrix task. Brain tissue was harvested for histology and immunohistochemical analyses. In the cortical-only ischemia, the average pasta matrix performance of both sham and stimulated groups reduced from 19 to 24 pieces to 7-8 pieces following the stroke induction. At the end of the four-week treatment, the performance of stimulated group was significantly greater than that of sham group (14 pieces vs 7 pieces, p < 0.0001). Similarly, in the combined cortical and striatal ischemia, the performance of both sham and stimulated groups reduced from 29 to 30 pieces to 7-11 pieces following the stroke induction. However, at the end of the four-week treatment, the performance of stimulated group was not significantly greater than that of sham group (15 pieces vs 11 pieces, p = 0.452). In the post-mortem analysis, the number of cells expressing CaMKIIα at the perilesional cortical and striatum of the LCN DBS treated animals receiving cortical-only stroke elevated but not those receiving cortical+striatal stroke. The current findings suggested that the observed, LCN DBS-enhanced motor recovery and perilesional plasticity may involve striatal mechanisms.

A Novel Foley Catheter-Based Brain Retraction Method for the Interhemispheric Approach: Technical Considerations and an Illustrative Video

BACKGROUND

Management of interhemispheric pathologies requires surgical intervention through a restricted anatomical corridor ensconced within critical cerebral structures. The use of retractors to facilitate operative access may cause damage to cerebral tissue. The development of an innovative retraction technique designed to alleviate cerebral damage in such cases is imperative. In this study, we present a novel and gentle retraction method to facilitate the interhemisferic approach.

METHODS

We retrospectively examined data of 9 right-handed patients who underwent surgical resection of interhemispheric lesions between 2021 and 2022. All patients underwent surgery for the first time because of this pathology. All operative specimens were histologically confirmed. Clinical characteristics, operative details, and follow-up data were retrospectively analyzed.

RESULTS

The new retraction technique was successfully applied to 8 tumor patients and 1 patient with an aneurysm. Eight patients had an anterior interhemispheric approach, and 1 patient had a posterior interhemispheric approach. Complete surgical excision was achieved in all patients with no postoperative complications. Postoperative Gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) showed no signs of ischemia or contusion. All patients exhibited significant improvements in their symptoms. An illustrative video that elucidates the removal of an interhemispheric epidermoid tumor, employing the anterior ipsilateral interhemispheric approach, featuring the novel retraction method.

CONCLUSIONS

The ideal retraction technique during the interhemispheric approach is still a challenge. Our novel retraction technique may help minimize brain parenchymal damage during surgical resection of interhemispheric lesions.

The diagnostic accuracy of cardiac ultrasound for acute myocardial ischemia in the emergency department: a systematic review and meta-analysis

BACKGROUND

Chest pain is responsible for millions of visits to the emergency department (ED) annually. Cardiac ultrasound can detect ischemic changes, but varying accuracy estimates have been reported in previous studies. We synthetized the available evidence to yield more precise estimates of the accuracy of cardiac ultrasound for acute myocardial ischemia in patients with chest pain in the ED and to assess the effect of different clinical characteristics on test accuracy.

METHODS

A systematic search for studies assessing the diagnostic accuracy of cardiac ultrasound for myocardial ischemia in the ED was conducted in MEDLINE, EMBASE, CENTRAL, CINAHL, LILACS, Web of Science, two trial registries and supplementary methods, from inception to December 6th, 2022. Prospective cohort, cross-sectional, case-control studies and randomized controlled trials (RCTs) that included data on diagnostic accuracy were included. Risk of bias was assessed with the QUADAS-2 tool and a bivariate hierarchical model was used for meta-analysis with paired Forest and SROC plots used to present the results. Subgroup analyses was conducted on clinically relevant factors.

RESULTS

Twenty-nine studies were included, with 5043 patients. The overall summary sensitivity was 79.3% (95%CI 69.0-86.8%) and specificity was 87.3% (95%CI 79.9-92.2%), with substantial heterogeneity. Subgroup analyses showed increased sensitivity in studies where ultrasound was conducted at ED admission and increased specificity in studies that excluded patients with previous heart disease, when the target condition was acute coronary syndrome, or when final chart review was used as the reference standard. There was very low certainty in the results based on serious risk of bias and indirectness in most studies.

CONCLUSIONS

Cardiac ultrasound may have a potential role in the diagnostic pathway of myocardial ischemia in the ED; however, a pooled accuracy must be interpreted cautiously given substantial heterogeneity and that important patient and test characteristics affect its diagnostic performance.

PROTOCOL REGISTRATION

PROSPERO (CRD42023392058).

Investigation of neuroprotective and therapeutic effects of cannabidiol in an acute coronary syndrome model

PURPOSE

The ischemia-reperfusion (I/R) injury seen in the heart can cause severe damage to essential organs such as the brain. Cannabidiol (CBD) obtained from Cannabis sativa is used today to treat various diseases. This study aimed to demonstrate CBD's neuroprotective and therapeutic properties in rats with brain damage caused by I/R in the heart.

MATERIALS

Rats were divided into four groups; sham, I/R, I/R + Prophylactic CBD, and I/R + Therapeutic CBD. End of the experiment, brain tissues were collected for biochemical, histopathological, and genetic examinations.

RESULTS

I/R damage increased the number of degenerative neurons, caspase-3 and TNF-α immunoexpression, total oxidant status levels, and oxidative stress index. Both prophylactic and therapeutic CBD administration reduced these increased values. In addition, the relative fold changes of AMPK, PGC-1α, SIRT1, and Bcl 2 decreased in the I/R group, and the relative fold change of Bax increased, which are indicators of ER stress and apoptosis. Both administrations of CBD reversed these genes' relative fold changes.

CONCLUSION

CBD can be protective against brain injury caused by cardiac I/R damage through antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

Targeting Aquaporin-5 by Phosphodiesterase 4 Inhibition Offers New Therapeutic Opportunities for Ovarian Ischemia Reperfusion Injury in Rats

This study aimed to examine the effect of Phosphodiesterase 4 (PDE4) inhibition on Aquaporin-5 (AQP5) and its potential cell signaling pathway in the ovarian ischemia reperfusion (OIR) model. Thirty adult female rats were divided into five groups: Group 1; Control: Sham operation, Group 2; OIR that 3 hour ischemia followed by 3 hour reperfusion, Group 3; OIR + Rolipram 1 mg/kg, Group 4; OIR + Rolipram 3 mg/kg, Group 5; OIR + Rolipram 5 mg/kg. Rolipram was administered intraperitoneally to the rats in groups 3-4 and 5 at determined doses 30 minutes before reperfusion. From ovary tissue; Tumor necrosis factor-a (TNF-α), Cyclic adenosine monophosphate (cAMP), Nuclear factor kappa (NF-κB), Interleukin-6 (IL-6), Phosphodiesterase 4D (PDE4D), Mitogen-activated protein kinase (MAPK) and AQP5 levels were measured by ELISA. We also measured the level of AQP5 in ovary tissue by real-time reverse-transcription polymerase chain reaction (RT-PCR). In the OIR groups; TNF-α, NF-κB, IL-6, MAPK inflammatory levels increased, and cAMP and AQP5 levels decreased, which improved with the administration of rolipram doses. Also histopathological results showed damaged ovarian tissue after OIR, while rolipram administration decrased tissue damage in a dose dependent manner. We propose that the protective effect of PDE4 inhibition in OIR may be regulated by AQP5 and its potential cell signaling pathway and may be a new target in OIR therapy. However, clinical studies are needed to appraise these data in humans.

The possible protective effect of l-cysteine in a rat model of sciatic nerve ischemia-reperfusion: A possible role for NRF1 and Caspase 3; Biochemical, Histological, and Immunohistochemical study

Organ damage brought on by ischemia is exacerbated by the reperfusion process. L-cysteine is a semi-essential amino acid that acts as a substrate for cystathionine-β-synthase in the central nervous system. The aim of this study was to investigate the possible protective effects of L- cysteine against the structural and biochemical changes that occur in the rat sciatic nerve after ischemia reperfusion (I/R) and to address some of the underlying mechanisms of these effects. Rats were divided into 4 groups: sham, l-cysteine, I/R, and l-cysteine- I/R groups. Specimens of sciatic nerve were processed for biochemical, histological, and immunohistochemical assessment. The results showed in I/R group, a significant increase in malondialdehyde with a significant decrease in both Nuclear respiratory factor-1 (NRF1) and superoxide dismutase levels. Moreover, with histological alteration. There was a significant increase in the mean surface area fraction of anti-caspase immunopositive cells as well as a significantdecrease in mean surface area fraction of anti-CD 34 immunopositive cells. In contrast, the l-cysteine- I/R group showed amelioration of these biochemical, structural, and immunohistochemical changes. To the best of our knowledge, this is the first study showed the protective effects of l-cysteine in sciatic nerve I/R via NRF1and caspase 3 modulation as well as telocyte activation.

Therapeutic potential of mitochondrial transplantation in modulating immune responses post-cardiac arrest: a narrative review

BACKGROUND

Mitochondrial transplantation (MTx) has emerged as a novel therapeutic strategy, particularly effective in diseases characterized by mitochondrial dysfunction. This review synthesizes current knowledge on MTx, focusing on its role in modulating immune responses and explores its potential in treating post-cardiac arrest syndrome (PCAS).

METHODS

We conducted a comprehensive narrative review of animal and human studies that have investigated the effects of MTx in the context of immunomodulation. This included a review of the immune responses following critical condition such as ischemia reperfusion injury, the impact of MTx on these responses, and the therapeutic potential of MTx in various conditions.

RESULTS

Recent studies indicate that MTx can modulate complex immune responses and reduce ischemia-reperfusion injury post-CA, suggesting MTx as a novel, potentially more effective approach. The review highlights the role of MTx in immune modulation, its potential synergistic effects with existing treatments such as therapeutic hypothermia, and the need for further research to optimize its application in PCAS. The safety and efficacy of autologous versus allogeneic MTx, particularly in the context of immune reactions, are critical areas for future investigation.

CONCLUSION

MTx represents a promising frontier in the treatment of PCAS, offering a novel approach to modulate immune responses and restore cellular energetics. Future research should focus on long-term effects, combination therapies, and personalized medicine approaches to fully harness the potential of MTx in improving patient outcomes in PCAS.

Effect of acidosis on adipose-derived stem cell impairment and gene expression

Based on disappointing results of stem cell-based application in clinical trials for patients with critical limb ischemia, we hypothesized that the acidic environment might be the key factor limiting cell survival and function. In the present study, we used microdialysis to determine presence of acidosis and metabolic imbalance in critical ischemia. Moreover, we explored the effect of extracellular acidosis on adipose-derived stem cells (ADSCs) at molecular and transcriptional level. Our data demonstrate that low pH negatively regulates cell proliferation and survival, also, it results in cell cycle arrest, mitochondrial dynamics disorder, DNA damage as well as the impairment of proangiogenic function in a pH-dependent manner. Further transcriptome profiling identified the pivotal signaling pathways and hub genes in response to acidosis. Collectively, these findings provide strong evidences for a critical role of acidosis in ADSCs impairment with ischemic condition and suggest treatments focus on tissue pH balance and acidosis-mediated hub genes may have therapeutic potential in stem cell-based application.

Acute Coronary Syndrome

One percent of primary care visits are due to chest pain. It is critical for the primary care physician to have a high index of suspicion for acute coronary syndrome and understand the management of this important condition. This article reviews the outpatient evaluation and management of chest pain and summarizes the key points of inpatient evaluation and treatment of acute coronary syndrome.

Anomalous Left Coronary Artery Originating From the Pulmonary Artery Diagnosed in an Adult

•ALCAPA presenting in adulthood is a rare cause of ischemic cardiomyopathy. •An unexplained dilated RCA should raise concern for ALCAPA. •Multimodality imaging is helpful for diagnosis, but often echo alone can be diagnostic. •Treatment is reimplantation of the LMCA.

Antioxidant nanozymes as next-generation therapeutics to free radical-mediated inflammatory diseases: A comprehensive review

Recent developments in exploring the biological enzyme mimicking properties in nanozymes have opened a separate avenue, which provides a suitable alternative to the natural antioxidants and enzymes. Due to high and tunable catalytic activity, low cost of synthesis, easy surface modification, and good biocompatibility, nanozymes have garnered significant research interest globally. Several inorganic nanomaterials have been investigated to exhibit catalytic activities of some of the key natural enzymes, including superoxide dismutase (SOD), catalase, glutathione peroxidase, peroxidase, and oxidase, etc. These nanozymes are used for diverse biomedical applications including therapeutics, imaging, and biosensing in various cells/tissues and animal models. In particular, inflammation-related diseases are closely associated with reactive oxygen and reactive nitrogen species, and therefore effective antioxidants could be excellent therapeutics due to their free radical scavenging ability. Although biological enzymes and other artificial antioxidants could perform well in scavenging the reactive oxygen and nitrogen species, however, suffer from several drawbacks such as the requirement of strict physiological conditions for enzymatic activity, limited stability in the environment beyond their optimum pH and temperature, and high cost of synthesis, purification, and storage make then unattractive for broad-spectrum applications. Therefore, this review systematically and comprehensively presents the free radical-mediated evolution of various inflammatory diseases (inflammatory bowel disease, mammary gland fibrosis, and inflammation, acute injury of the liver and kidney, mammary fibrosis, and cerebral ischemic stroke reperfusion) and their mitigation by various antioxidant nanozymes in the biological system. The mechanism of free radical scavenging by antioxidant nanozymes under in vitro and in vivo experimental models and catalytic efficiency comparison with corresponding natural enzymes has also been presented.

Effectiveness of Cerebrospinal Fluid Lumbar Drainage Among Patients with Aneurysmal Subarachnoid Hemorrhage: An Updated Systematic Review and Meta-Analysis

INTRODUCTION

Cerebral vasospasm in patients after aneurysmal subarachnoid hemorrhage (aSAH) continues to be a major source of morbidity despite significant clinical and basic science research. The removal of blood and its degradation products from the subarachnoid space through prophylactic lumbar drainage (LD) is a favorable option. However, several studies have delivered conflicting conclusions on its efficacy after aSAH.

METHODS

Systematic searches of Medline, Embase, and Cochrane Central Register of Controlled Trials were performed. The primary outcome was a good functional outcome (modified Rankin scale score, 0-2). Secondary outcomes included symptomatic vasospasm, secondary cerebral infarction, and mortality.

RESULTS

A total of 14 studies reporting on 2473 patients with aSAH were included in the meta-analysis. Compared with the non-LD group, no significant differences were found in the rates of good functional outcomes in the LD group at discharge to 1 month (risk ratio [RR], 1.28; 95% confidence interval [CI], 0.64-2.58) or at 6 months (RR, 1.12; 95% CI, 0.97-1.41). These findings were consistent in the subgroup analyses of only randomized controlled trials or observational studies. LD was associated with lower rates of symptomatic vasospasm (RR, 0.61; 95% CI, 0.48-0.77), secondary cerebral infarction (RR, 0.59; 95% CI, 0.45-0.79), and mortality at discharge to 1 month (RR, 0.58; 95% CI, 0.41-0.82). The effect on mortality diminished at 6 months (RR, 0.70; 95% CI, 0.34-1.45). However, when analyzing only randomized controlled trials, the benefit of LD on lower rates of mortality continued even at 6 months (RR, 0.75; 95% CI, 0.58-0.99).

CONCLUSIONS

For aSAH patients, the use of LD is associated with benefits in the rates of vasospasm, secondary cerebral infarctions, and mortality, without an increased risk of adverse events.

Anti-seizure medication-induced developmental cell death in neonatal rats is unaltered by history of hypoxia

BACKGROUND

Many anti-seizure medications (ASMs) trigger neuronal cell death when administered during a confined period of early life in rodents. Prototypical ASMs used to treat early-life seizures such as phenobarbital induce this effect, whereas levetiracetam does not. However, most prior studies have examined the effect of ASMs in naïve animals, and the degree to which underlying brain injury interacts with these drugs to modify cell death is poorly studied. Moreover, the degree to which drug-induced neuronal cell death differs as a function of sex is unknown.

METHODS

We treated postnatal day 7 Sprague Dawley rat pups with vehicle, phenobarbital (75 mg/kg) or levetiracetam (200 mg/kg). Separate groups of pups were pre-exposed to either normoxia or graded global hypoxia. Separate groups of males and females were used. Twenty-four hours after drug treatment, brains were collected and processed for markers of cell death.

RESULTS

Consistent with prior studies, phenobarbital, but not levetiracetam, increased cell death in cortical regions, basal ganglia, hippocampus, septum, and lateral thalamus. Hypoxia did not modify basal levels of cell death. Females - collapsed across treatment and hypoxia status, displayed a small but significant increase in cell death as compared to males in the cingulate cortex, somatosensory cortex, and the CA1 and CA3 hippocampus; these effects were not modulated by hypoxia or drug treatment.

CONCLUSION

We found that a history of graded global hypoxia does not alter the neurotoxic profile of phenobarbital. Levetiracetam, which does not induce cell death in normal developing animals, maintained a benign profile on the background of neonatal hypoxia. We found a sex-based difference, as female animals showed elevated levels of cell death across all treatment conditions. Together, these data address several long-standing gaps in our understanding of the neurotoxic profile of antiseizure medications during early postnatal development.

Electromechanical Response of Mesenteric Ischemia Defined Through Simultaneous High-Resolution Bioelectrical and Video Mapping

Intestinal motility is governed in part by bioelectrical slow-waves and spike-bursts. Mesenteric ischemia is a substantial clinical challenge, but its electrophysiological and contractile mechanisms are not well understood. Simultaneous high-resolution bioelectrical and video mapping techniques were used to capture the changes in slow-waves, spike-bursts, and contractile activity during baseline, ischemia, and reperfusion periods. Experiments were performed on anesthetized pigs where intestinal contractions were quantified using surface strain and diameter measurements, while slow-wave and spike-bursts were quantified using frequency and amplitude. Slow-waves entrainment within the ischemic region diminished during ischemia, resulting in irregular slow-wave activity and a reduction in the frequency from 12.4 ± 3.0 cycles-per-minute (cpm) to 2.5 ± 2.7 cpm (p = 0.0006). At the end of the reperfusion period, normal slow-wave entrainment was observed at a frequency of 11.5 ± 2.9 cpm. There was an increase in spike-burst activity between the baseline and ischemia periods (1.1 ± 1.4 cpm to 8.7 ± 3.3 cpm, p = 0.0003) along with a spasm of circumferential contractions. At the end of the reperfusion period, the frequency of spike-bursts decreased to 2.7 ± 1.4 cpm, and contractions subsided. The intestine underwent tonal contraction during ischemia, with the diameter decreasing from 29.3 ± 2.6 mm to 21.2 ± 6.2 mm (p = 0.0020). At the end of the reperfusion period, the intestinal diameter increased to 27.3 ± 3.9 mm. The decrease in slow-wave activity, increase in spike-bursts, and tonal contractions can objectively identify ischemic segments in the intestine. It is anticipated that the use of electrophysiological slow-wave and spike-burst biomarkers, along with contractile measures, could identify mesenteric ischemia in surgical settings and allow an objective biomarker for successful revascularization.

Neuroprotective properties of Betulin, Betulinic acid, and Ursolic acid as triterpenoids derivatives: a comprehensive review of mechanistic studies

Cognitive deficits are the main outcome of neurological disorders whose occurrence has risen over the past three decades. Although there are some pharmacologic approaches approved for managing neurological disorders, it remains largely ineffective. Hence, exploring novel nature-based nutraceuticals is a pressing need to alleviate the results of neurodegenerative diseases, such as Alzheimer's disease (AD) and other neurodegenerative disorders. Some triterpenoids and their derivates can be considered potential therapeutics against neurological disorders due to their neuroprotective and cognitive-improving effects. Betulin (B), betulinic acid (BA), and ursolic acid (UA) are pentacyclic triterpenoid compounds with a variety of biological activities, including antioxidative, neuroprotective and anti-inflammatory properties. This review focuses on the therapeutic efficacy and probable molecular mechanisms of triterpenoids in damage prevention to neurons and restoring cognition in neurodegenerative diseases. Considering few studies on this concept, the precise mechanisms that mediate the effect of these compounds in neurodegenerative disorders have remained unknown. The findings can provide sufficient information about the advantages of these compounds against neurodegenerative diseases.

Hemoglobin in large vessel occlusion: Look further than collaterals

BACKGROUND

Abnormal hemoglobin (Hb) levels lead to poorer outcomes in ischemic stroke, though the mechanisms remain elusive. We aimed to study the role of Hb on imaging and clinical outcomes, namely on collaterals as it is a known mediator of infarct growth.

METHODS

Retrospective cohort study of patients with large vessel occlusion ischemic stroke admitted to our center. Demographics, clinical and imaging variables were collected, particularly baseline hemoglobin, presence of anemia and collateral score. Collaterals were scored from 0 to 3 and defined as poor if 0-1. Multivariable analyses were performed for collateral score and clinical outcomes (3-month mortality and good prognosis).

RESULTS

We included 811 patients, 215 (26.5 %) with anemia. Patients with anemia were older, had more comorbidities and more severe strokes. Hemoglobin levels and anemia were not associated with collateral score (OR 0.97, 95 % CI 0.89-1.05, p = 0.414 and OR 0.89, 95 % CI 0.64-1.24, p = 0.487, respectively) nor with poor collaterals (OR 0.96, 95 % CI 0.88-1.05, p = 0.398 and OR 0.86, 95 % CI 0.60-1.23, p = 0.406, respectively). Hb levels were associated with 3-month mortality (OR 0.85, 95 % CI 0.76-0.96, p = 0.008).

CONCLUSION

Hemoglobin or anemia were not found to be associated with collateral status. Our results raise further questions regarding the pathophysiology of anemia and outcomes in ischemic stroke, highlighting the need for future research.

Anti-ischemic and pleiotropic effects of ranolazine in chronic coronary syndromes

The vast majority of antianginal drugs decrease heart rate and or blood pressure levels or the inotropic status of the left ventricle to decrease myocardial oxygen consumption (MVO2) and thus anginal symptoms. Ranolazine presents a completely different mechanism of action, which reduces the sodium-dependent calcium overload inhibiting the late sodium current. Current European Society of Cardiology (ESC) guidelines for the management of angina in patients with chronic coronary symptoms recommend the use of several drugs such as ranolazine, b-blockers, calcium channel blockers, long-acting nitrates, ivabradine, nicorandil and trimetazidine for angina relief. However, ranolazine, in addition to symptom relief properties, is an antianginal drug showing favorable effects in decreasing the arrhythmic burden and in ameliorating the glycemic profile of these patients. In this review, we summarize the available data regarding the antianginal and pleiotropic effects of this drug.