Clinical characteristics and neuroimaging findings in eagle syndrome induced internal jugular vein stenosis

Background

Eagle syndrome is a condition that causes pharyngeal pain, facial pain, swallowing difficulties, and symptoms of arterial impingement due to the elongated styloid process. However, few reports were about eagle syndrome with venous compression up to now. This study aimed to identify the clinical profiles of the internal jugular vein stenosis (IJVS) related eagle syndrome comprehensively.

Methods

A total of 27 patients, who were diagnosed as IJVS induced by styloid process compression were enrolled. The clinical manifestations and imaging features were analyzed.

Results

Styloid process compression was presented in all of the 27 IJVS patients, in which, the top three symptoms included insomnia (81.5%), tinnitus (63.0%) and head noises (63.0%). The most vulnerable segment of internal jugular vein (IJV) was J3 segment (96.3%). The average styloid process length in our study was 3.7 cm. Hearing impairment was more common in bilateral IJVS (68.8% vs. 18.2%, P=0.018). One patient reported significant relief of symptoms at 1 year follow-up after underwent styloidectomy combined with stenting.

Conclusions

Neurological symptoms of eagle syndrome induced IJVS were various, including either arterial or venous issues. Better understanding of this disease entity may be helpful for clinical diagnosis and treatment.

New Endovascular Approach for Hypothermia With Intrajugular Cooling and Neuroprotective Effect in Ischemic Stroke

Background and Purpose—

Induction of hypothermia as a stroke therapy has been limited by logistical challenges. This study was designed to determine the hypothermic and neuroprotective efficacy of infusing cold saline directly into the internal jugular (IJ) vein and compare the effects of IJ hypothermia to those achieved by intracarotid artery hypothermia in an ischemic stroke model.

Methods—

The right middle cerebral artery was occluded in rats using an intraluminal filament. Immediately following reperfusion, hypothermia was achieved by infusing isotonic saline through microcatheter into the right IJ or right intracarotid over 30 minutes. Infarct sizes, neurological deficits, blood-brain barrier damage, edema volume, blood-brain barrier associated molecules (MMP-9 [matrix metallopeptidase 9] and AQP-4 [aquaporin 4]), and apoptosis-associated proteins (Bcl-2 and cleaved Caspase-3) were measured.

Results—

We found that both IJ- and intracarotid-based infusion cooled the brain robustly with a minimal effect on rectal temperatures. This brain cooling led to significantly reduced infarct volumes at 24 hours after reperfusion, as well as decreased expression of the proapoptotic protein cleaved Caspase-3 and increased expression of the antiapoptotic protein Bcl-2. Intracarotid and IJ cooling also aided in blood-brain barrier maintenance, as shown by decreased edema volumes, reduced Evans Blue leakage, and decreased expression of edema-facilitating proteins (MMP-9 and AQP-4). Both cooling methods then translated to preserved neurological function as determined by multiple functional tests over a 28-day observation period. Most importantly, the cooling and neuroprotective efficacy of IJ cooling was comparable to intracarotid cooling by almost every metric evaluated.

Conclusions—

Compared with intracarotid infusion, IJ infusion conferred a similar degree of hypothermia and neuroprotection following ischemic stroke. Given the ease of establishing vascular access via the internal jugular vein and the powerful neuroprotection that hypothermia provides, IJ brain cooling could be used as a promising hypothermia-induction modality going forward.

Abstract 122: Selective Intra-Arterial Cooling (SI-AC) Improve Recovery in a Nonhuman Primate Model of Ischemic Stroke

Background and Purpose: Recent findings from our group prove that selective intra-arterial cooling (SI-AC) treatment leads to prominent and persistent functional improvements after stroke in both rodents and non-human primate (NHPs) stroke models. In this study, neuro-protective potentials of SI-AC treatment were further explored at brain network and histopathological levels in preclinical higher-order brains.

Methods: Cerebral ischemia/reperfusion was induced by thrombus and thrombolysis (t-PA) in adult rhesus monkeys (n=10). SI-AC treatment was randomly given to 5 models. Conventional MRI and diffusion tensor imaging scans were performed 4 h, 7 and 30 days post focal ischemia. Effects on functional recovery were also assessed through longitudinal neurologic scores and behavior tests. Animals were euthanized after the final scan for histological analysis.

Results: SI-AC treatment led to a higher rate of infarct reversal, significantly mitigated neurologic deficits, and more preserved dexterity when compared with those only receiving t-PA during a 30-day observation period. More fiber numbers, a higher FA values based on DTI analysis, and a higher integrity of white matter based on immunochemistry in ipsilateral side were observed in models receiving t-PA plus SI-AC during the same observation period. Histological findings, consistent with MRI images in the infarct size and reversal, indicated that myelin damage, spheroids, and spongiosis were significantly improved in models receiving SI-AC treatment than those with t-PA alone treatment.

Conclusions: Our findings further supported that SI-AC as an adjunctive treatment could significantly improve neural tissue and functional preservation in a large animal model, suggesting its potential application in ischemic stroke treatments.

Abstract TP278: Gradually-Induced Hypoxic Conditioning Attenuates Blood-Brain-Barrier Disruption via Fatty Acid β-Oxidation of Cerebrovascular Endothelial Cells After Cerebral Ischemia/Reperfusion in Mice

Background: Hypoxic conditioning protects against ischemic brain injury, while the mechanisms on BBB disruption remains unknown. To date, no study has examined the role of FAO in hypoxic conditioning-afforded blood-brain-barrier (BBB) protection. We explored the hypoxia conditioning-induced protection and related molecular mechanism with FAO in BBB against ischemia/reperfusion injury.

Methods: Focal ischemia/reperfusion model was induced in C57Bl/6J mice by transient middle cerebral artery occlusion (MCAO) for 60 min. Mice were placed in hypoxia chamber, in which the oxygen concentration were reduced from 21% to 5% at a constant rate within 50 min at 10 min after MCAO surgery. BBB permeability was determened by IgG immunohistochemical stain at 24 h after reperfusion. In vitro BBB permeability was determined by measuring leakage of 3kDa-dextran and 55 kDa-dextran in oxygen glucose deprivation (OGD). Tight junction proteins (occludin and claudin-5) and fatty acid β-oxidation (FAO) rate-limiting enzyme, CPT1A, were measured by Western blot for protein and real time PCR for mRNA, in the isolated cerebral microvessels.

Results: The hypoxic conditioning (HC) reduced mortality from 33.3% to 0% and improved neurological outcomes (scores?) after 35 days of reperfusion. HC mitigated BBB leakage and reduced the loss of tight junction proteins in cerebral microvessels at 24 h after reperfusion. RNA sequence of the endothelial cells showed that HC enhanced the expression of CPT1A and increased the FAO level. Co-stained microvessels in situ with CAPT1 and endothelium cell marker (CD31) showed that HC increased the expression of CPT1A. CPT1A expression in microvessels was decreased after ischemia/reperfusion, while HC restored the protein to the non-ischemic control levels. In vitro BBB model, HC reduced OGD-induced dye leakage. HC significantly increased the mRNA and protein expression of CPT1A. FAO inhibitor, etomoxir, or siRNA-mediated CPT1A knockdown diminished the protection of GHT on the BBB integration-by 80.7% and 76.9%. Supplementation of acetate (a downstream product of FAO) enhanced the protection of HC.

Conclusions: Our results suggest that FAO and signaling play an important role in BBB protection of HC against ischemia/reperfusion injury.

Advances in Normobaric Hyperoxia Brain Protection in Experimental Stroke

As we all know that stroke is still a leading cause of death and acquired disability. Etiological treatment and brain protection are equally important. This review aimed to summarize the advance of normobaric-hyperoxia (NBHO) on brain protection in the setting of experimental stroke and brain trauma. We analyzed the data from relevant studies published on PubMed Central (PMC) and EMBASE, about NBHO on brain protection in the setting of experimental ischemic and hemorrhagic strokes and brain trauma, which revealed that NBHO had important value on improving hypoxia and attenuating ischemia damage. The mechanisms of NBHO involved increasing the content of oxygen in brain tissues, restoring the function of mitochondria, enhancing the metabolism of neurons, alleviating blood-brain barrier (BBB) damage, weakening brain cell edema, reducing intracranial pressure, and improving cerebral blood flow, especially in the surrounding of injured area of the brain, to make the neurons in penumbral area alive. Compared to hyperbaric oxygen (HBO), NBHO is more safe and more easily to transform to clinical use, whereby, further studies about the safety and efficacy as well as the proper treatment protocol of NBHO on human may be still needed.

Relationship between elevated plasma trimethylamine N-oxide levels and increased stroke injury

Objective

To investigate whether elevated plasma trimethylamine N-oxide (TMAO) levels are associated with initial stroke severity and infarct volume.

Methods

This cross-sectional study included 377 patients with acute ischemic stroke and 50 healthy controls. Plasma TMAO levels were assessed at admission. Stroke infarct size and clinical stroke severity were measured with diffusion-weighted imaging and the NIH Stroke Scale (NIHSS). Mild stroke was defined as an NIHSS score <6.

Results

Plasma TMAO levels were higher in patients with ischemic stroke than in healthy controls (median 5.1 vs 3.0 μmol/L; p < 0.001). Every 1–µmol/L increase in TMAO was associated with a 1.13-point increase in NIHSS score (95% confidence interval [CI] 1.04–1.29; p < 0.001) and 1.69-mL increase in infarct volume (95% CI 1.41–2.03; p < 0.001) after adjustment for vascular risk factors. At admission, 159 patients (42.2%) had experienced a mild stroke, and their plasma TMAO levels were lower compared to those with moderate to severe stroke (median 3.6 vs 6.5 µmol/L; p < 0.001). The area under the receiver operating characteristics curve of plasma TMAO level in predicting moderate to severe stroke was 0.794 (95% CI 0.748–0.839; p < 0.001), and the optimal cutoff value was 4.95 μmol/L. The sensitivity and specificity of TMAO levels ≥4.95 μmol/L for moderate to severe stroke were 70.2% and 79.9%, respectively.

Conclusions

Patients with ischemic stroke had higher plasma TMAO levels compared to healthy controls. Higher plasma TMAO level at admission is an independent predictor of stroke severity and infarct volume in patients with acute ischemia.

Safety and Tolerability of Both Arm Ischemic Conditioning in Patients With Major Depression: A Proof of Concept Study

PURPOSE

A substantial proportion of patients with major depressive disorder (MDD) does not respond or cannot tolerate to currently available treatments. This study was to assess the safety and tolerability of Remote Limb Ischemic Preconditioning (RLIPC) as an adjunctive therapy in patients with MDD.

PATIENTS AND METHODS

Enrolled patients underwent RLIPC, five cycles of simultaneous bilateral arm ischemia, 5 min and followed by reperfusion of each cycle, and once daily for eight consecutive weeks. Depression and anxiety severity, and quality of life were assessed every 2 weeks. Descriptive analysis was used for safety and tolerability data.

RESULTS

Thirty-seven participants completed at least one RLIPC. Twenty-four of them (64.9%) completed the study. Twelve patients prematurely discontinued the study due to poor adherence, and one due to a mild side effect. The changes in HRSD-17, GAD-7 and QOL-6 total scores from baseline to the endpoint were significant from the end of second week treatment onwards. The responder and remission rates were 59.46% (22/37) and 54.05% (20/37) at the endpoint, respectively.

CONCLUSION

RLIPC was safe and well tolerated, and may be effective in reducing depressive symptoms in patients with MDD. Large studies are warranted to test its efficacy and safety as monotherapy or adjunctive therapy in the treatment of MDD.

The comparative analysis of non-thrombotic internal jugular vein stenosis and cerebral venous sinus stenosis

Internal jugular vein (IJV) stenosis and cerebral venous sinus (CVS) stenosis belong to cerebral venous outflow insufficiency. This study aimed to analyze the similarities and differences between IJV stenosis and CVS stenosis. Patients with either IJV stenosis or CVS stenosis confirmed by contrast-enhanced magnetic resonance venography between October 2017 and July 2018 were enrolled in this retrospective study. The similarities and differences between IJV stenosis and CVS stenosis on the aspects of clinical and imaging features were compared. A total of 82 eligible patients entered into the final analysis. The similarities of the two subsets of cerebral venous outflow insufficiency mainly included headache, head noises or tinnitus, visual disorders, and sleeping disorders, as well as cloud-like white matter hyperintensity in T2WI and FLAIR sequences of MRI. However, there were differences in between, the ratio of patients with higher intracranial pressure (ICP) was common in CVS stenosis (p < 0.001). Namely, higher ratios of papilledema (p = 0.001) and visual damage (p = 0.029), as well as poor Frisen papilledema grade scores were more commonly observed in CVS stenosis (p = 0.004), while abnormal collateral-vessels appeared more frequently in IJV stenosis (100.00%) than CVS stenosis (28.57%). Continuous head noises, tinnitus and cloud-like white matter hyperintensity in MRI are the features of both IJV stenosis and CVS stenosis. Whereas, severe headache, visual damage, papilledema, and intracranial hypertension (IH) were more common in CVS stenosis, and the appearance of collateral-vessels is a key feature of IJV stenosis.

Metabolic syndrome and risks of carotid atherosclerosis and cardiovascular events in community-based older adults in China

BACKGROUND AND OBJECTIVES

Previous studies on the importance of metabolic syndrome (MS) as a cardiovascular risk factor had not focused on older Chinese adults. The present study analyzed the association of MS with carotid atherosclerosis and the risk of cardiovascular events in Chinese adults.

METHODS AND STUDY DESIGN

Data of a representative cohort study with 5-year follow-up were used. Community-dwelling people (n=1257) aged ≥55 years without cardiovascular disease (CVD) at baseline were followed up from 2009 to 2014. MS was defined based on the Chinese Diabetes Society criteria under the Chinese Medical Association. Multiple regression analyses were performed to examine the associations of MS with atherosclerosis and CVD events, with adjustment for confounding factors.

RESULTS

In a multivariate logistic regression model with adjustment, MS was closely related to common carotid artery intima-media thickness (CCA-IMT) (1.62; 95% CI: 1.19-2.21) and carotid plaque presence (1.38; 95% CI: 1.01-1.89), but not with carotid artery stenosis. At the end of the 5-year follow- up, compared with subjects without MS, hazard ratios and 95% confidence intervals for the different risks in subjects with MS were 1.86 (1.02-3.29) for myocardial infarction (MI), 1.39 (1.01-2.05) for stroke, 1.52 (1.02- 2.37) for CVD death, and 1.13 (0.62-2.58) for total death, after adjusting for age, gender, smoking, drinking, physical activity, uric acid, high-sensitivity C-reactive protein, dietary factors and carotid atherosclerosis status.

CONCLUSIONS

MS was significantly associated with IMT and the presence of carotid plaque and with positively increased risks of MI, stroke, and CVD mortality independent of CVD risk factors in older Chinese adults.

Clinical and neuroimaging correlates among cohorts of cerebral arteriostenosis, venostenosis and arterio-venous stenosis

The purpose of this study was to discriminate the clinical and imaging correlates of cerebral arterial stenosis (CAS), venous stenosis (CVS) and arterio-venous stenosis (CAVS) in the clinical setting. Patients were classified into three groups: CAS (n = 75), CVS (n=74) and CAVS (n=67). Focal neurological deficits were the prominent presenting symptoms in CAS group, while venous turbulence related symptoms were common in both CVS and CAVS group. Risk factor analysis showed the OR (95%CI) for diabetes, male gender and age in CAS vs. CVS group were 13.67(2.71, 68.85), 6.69(2.39, 18.67) and 1.07(1.03, 1.12) respectively. Male gender, diabetes and age in CAVS vs. CAS groups were 0.27(0.11, 0.63), 0.26(0.10, 0.67) and 1.09(1.04, 1.14) respectively, while age in CAVS vs. CVS group was 1.11(1.07, 1.15). The white matter lesions (WMLs) in CAS group varied in size, with clear boundaries asymmetrically distributed in bilateral hemispheres. CVS-induced WMLs revealed a bilaterally symmetric, cloudy-like appearance. The cerebral perfusion was asymmetrically reduced in CAS but symmetrically reduced in CVS group. The clinical characteristics and neuroimaging presentations were different among patients with CAS, CVS and CAVS. We recommended for aged patients, both arterial and venous imaging should be considered in diagnosis of cerebral stenotic vascular disorders.

Inhibition of histone deacetylase 3 by MiR-494 alleviates neuronal loss and improves neurological recovery in experimental stroke

HDAC3 is an essential negative regulator of neuronal plasticity and memory formation. Although a chemical inhibitor has been invented, little is known about its endogenous modulators. We explored whether miR-494 affects HDAC3-mediated neuronal injury following acute ischemic stroke. A substantial increase in plasma miR-494 was detected in AIS patients and was positively associated with the mRS at one year after symptom onset. The miR-494 levels were transiently increased in the infarcted brain tissue of mice. In contrast, miR-494 levels were reduced in neurons but increased in the medium after OGD. Intracerebroventricular injection of miR-494 agomir reduced neuronal apoptosis and infarct volume at the acute stage of MCAO, promoted axonal plasticity and long-term outcomes at the recovery stage, suppressed neuronal ataxin-3 and HDAC3 expression and increased acetyl-H3K9 levels in the ipsilateral hemisphere. In vitro studies confirmed that miR-494 posttranslationally inhibited HDAC3 in neurons and prevented OGD-induced neuronal axonal injury. The HDAC3 inhibitor increased acetyl-H3K9 levels and reversed miR-494 antagomir-aggravated acute cerebral ischemic injury, as well as brain atrophy and long-term functional recovery. These results suggest that miR-494 may serve as a predictive biomarker of functional outcomes in AIS patients and a potential therapeutic target for the treatment of ischemic stroke.

TNFα-induced Up-regulation of Ascl2 Affects the Differentiation and Proliferation of Neural Stem Cells

The molecular mediators underlying the effects of inflammation on neural stem cells (NSCs) are not fully characterized. In this study, we identified Ascl2 as a downstream basic helix-loop-helix (bHLH) transcription factor in NSCs following exposure to TNFα. Under normal conditions, Ascl2 expression is inhibited at post-transcriptional levels by miR-26a, which targets the 3’ untranslated region (UTR) of Ascl2. Upon exposure to TNFα, miR-26a expression is reduced, which leads to up-regulation of Ascl2. Overexpression of Ascl2 promotes neuronal differentiation, reduces proliferation, and increases the level of cleaved CASPASE 3 in NSCs, as observed in the in vitro and in ovo experiments. Ascl2 may serve in NSCs as a standby factor that readily responds to TNFα, which is often induced in inflammatory situations. In a chronic inflammatory condition with consistent up-regulation of TNFα, overexpression of Ascl2 may inhibit neurogenesis as a net result.

Brain-to-cervical lymph node signaling after stroke

After stroke, peripheral immune cells are activated and these systemic responses may amplify brain damage, but how the injured brain sends out signals to trigger systemic inflammation remains unclear. Here we show that a brain-to-cervical lymph node (CLN) pathway is involved. In rats subjected to focal cerebral ischemia, lymphatic endothelial cells proliferate and macrophages are rapidly activated in CLNs within 24 h, in part via VEGF-C/VEGFR3 signalling. Microarray analyses of isolated lymphatic endothelium from CLNs of ischemic mice confirm the activation of transmembrane tyrosine kinase pathways. Blockade of VEGFR3 reduces lymphatic endothelial activation, decreases pro-inflammatory macrophages, and reduces brain infarction. In vitro, VEGF-C/VEGFR3 signalling in lymphatic endothelial cells enhances inflammatory responses in co-cultured macrophages. Lastly, surgical removal of CLNs in mice significantly reduces infarction after focal cerebral ischemia. These findings suggest that modulating the brain-to-CLN pathway may offer therapeutic opportunities to ameliorate systemic inflammation and brain injury after stroke.

Silencing of microRNA-494 inhibits the neurotoxic Th1 shift via regulating HDAC2-STAT4 cascade in ischaemic stroke

BACKGROUND AND PURPOSE

T helper cell 1 (Th1)-skewed neurotoxicity contributes to the poor outcome of stroke in rodents. Here, we have elucidated the mechanism of the Th1/Th2 shift in acute ischaemic stroke (AIS) patients at hyperacute phase and have looked for a miRNA-based therapeutic target.

EXPERIMENTAL APPROACH

MiR-494 levels in blood from AIS patients and controls were measured by real-time PCR. C57BL/6J mice were subjected to transient middle cerebral artery occlusion, and cortical neurons were subjected to oxygen-glucose deprivation. Luciferase reporter system, chromatin immunoprecipitation sequencing (ChIP-Seq), and ChIP-PCR were used to uncover possible mechanisms.

KEY RESULTS

In lymphocytes from AIS patients, there was a Th1/Th2 shift and histone deacetylase 2 (HDAC2) was markedly down-regulated. ChIP-seq showed that HDAC2 binding sites were enriched in regulation of Th1 cytokine production, and ChIP-PCR confirmed that HDAC2 binding was changed at the intron of STAT4 and the promoter of T-box transcription factor 21 (T-bet) in lymphocytes from AIS patients. MiR-494 was the most significantly increased miRNA in lymphocytes from AIS patients, and miR-494-3p directly targeted HDAC2. A strong association existed between miR-494 and Th1 cytokines, and neurological deficit as measured by the National Institute of Health Stroke Scale (NIHSS) in AIS patients. In vitro and in vivo experiments showed that antagomir-494 reduced Th1 shift-mediated neuronal and sensorimotor functional damage in the mouse model of ischaemic stroke, via the HDAC2-STAT4 pathway.

CONCLUSION AND IMPLICATIONS

We demonstrated that miR-494 inhibition prevented Th1-skewed neurotoxicity through regulation of the HDAC2-STAT4 cascade.

Probable factors affecting clinical outcomes of internal jugular vein stenosis

Background

Internal jugular vein stenosis (IJVS) has recently aroused increasing interests, whereas, the factors affecting its clinical outcomes are not clear. This study aims to explore the probable factors affected clinical prognosis by evaluating the IJVS with different etiologies and strategies.

Methods

Patients with IJVS confirmed by contrast-enhanced magnetic resonance venography (CE-MRV) were enrolled from October 2017 through October 2018. One-year clinical outcomes of the IJVS cases enrolled in this study were assessed by outpatient and telephone follow-up using the Patient Global Impression of Change (PGIC) scores. According to the etiologies, patients were divided into thrombotic IJVS and non-thrombotic IJVS groups. And further, non-thrombotic IJVS group was divided into external compression and non-external compression subgroups. Outcomes of IJVS with different etiologies and strategies were compared and the probable prognostic factors were analyzed.

Results

A total of 118 eligible patients enrolled in this study, including 76 females and 42 males, mean aged 55.07±14.61 years. The average follow-up duration after discharge was 13.22±3.80 months. According to the PGIC scores, we categorized patients as good outcome and poor outcome groups. For thrombotic IJVS, patients underwent standard anticoagulant obtained remarkable PGIC improvement (100.0% vs. 33.3%, P=0.038). For non-thrombotic IJVS, stenting showed benefit in non-external compression subgroup (26.9% vs. 3.3%, P=0.019) but not in external compression subgroup. In addition, we found that in this Chinese IJVS cohort, poor outcomes involved old age (P=0.004), type 2 diabetes mellitus (P=0.036), previous hepatitis B virus (HBV) infection (P=0.027), and head noises (P=0.002). Multivariate logistic regression analysis indicated that continuous head noises [P=0.045, odds ratio (OR): 2.412, 95% confidence interval (CI): 1.019-5.711], as a unique symptom of IJVS may be significantly related to poor outcomes.

Conclusions

In this Chinese cohort, elderly degenerative bone compression, type 2 diabetes mellitus, and previous HBV infection are the top-three probable etiologies of non-thrombotic IJVS and may involve poor outcome. Long-term head noises may predict IJVS and with poor outcome. Thrombosis-induced IJVS may get benefit from standard anticoagulation. Non-external compression IJVS can be corrected by stenting.

Synergistic Interaction Between Zinc and Reactive Oxygen Species Amplifies Ischemic Brain Injury in Rats

Background and Purpose- Although intracellular zinc accumulation has been shown to contribute to neuronal death after cerebral ischemia, the mechanism by which zinc keeps on accumulating to cause severe brain damage remains unclear. Herein the dynamic cause-effect relationships between zinc accumulation and reactive oxygen species (ROS) production during cerebral ischemia/reperfusion are investigated. Methods- Rats were treated with zinc chelator, ROS scavenger, mitochondria-targeted ROS inhibitor, or NADPH oxidase inhibitor during a 90-minute middle cerebral artery occlusion. Cytosolic labile zinc, ROS level, cerebral infarct volume, and neurological functions were assessed after ischemia/reperfusion. Results- Zinc and ROS were colocalized in neurons, leading to neuronal apoptotic death. Chelating zinc reduced ROS production at 6 and 24 hours after reperfusion, whereas eliminating ROS reduced zinc accumulation only at 24 hours. Furthermore, suppression of mitochondrial ROS production reduced the total ROS level and brain damage at 6 hours after reperfusion but did not change zinc accumulation, indicating that ROS is produced mainly from mitochondria during early reperfusion and the initial zinc release is upstream of ROS generation after ischemia. Suppression of NADPH oxidase decreased ROS generation, zinc accumulation, and brain damage only at 24 hours after reperfusion, indicating that the majority of ROS is produced by NADPH oxidase at later reperfusion time. Conclusions- This study provides the direct evidence that there exists a positive feedback loop between zinc accumulation and NADPH oxidase-induced ROS production, which greatly amplifies the damaging effects of both. These findings reveal that different ROS-generating source contributes to ischemia-generated ROS at different time, underscoring the critical importance of spatial and temporal factors in the interaction between ROS and zinc accumulation, and the consequent brain injury, after cerebral ischemia/reperfusion.

Remote ischemic conditioning: a promising therapeutic intervention for multi-organ protection

Despite decades of formidable exploration, multi-organ ischemia-reperfusion injury (IRI) encountered, particularly amongst elderly patients with clinical scenarios, such as age-related arteriosclerotic vascular disease, heart surgery and organ transplantation, is still an unsettled conundrum that besets clinicians. Remote ischemic conditioning (RIC), delivered via transient, repetitive noninvasive IR interventions to distant organs or tissues, is regarded as an innovative approach against IRI. Based on the available evidence, RIC holds the potential of affording protection to multiple organs or tissues, which include not only the heart and brain, but also others that are likely susceptible to IRI, such as the kidney, lung, liver and skin. Neuronal and humoral signaling pathways appear to play requisite roles in the mechanisms of RIC-related beneficial effects, and these pathways also display inseparable interactions with each other. So far, several hurdles lying ahead of clinical translation that remain to be settled, such as establishment of biomarkers, modification of RIC regimen, and deep understanding of underlying minutiae through which RIC exerts its powerful function. As this approach has garnered an increasing interest, herein, we aim to encapsulate an overview of the basic concept and postulated protective mechanisms of RIC, highlight the main findings from proof-of-concept clinical studies in various clinical scenarios, and also to discuss potential obstacles that remain to be conquered. More well designed and comprehensive experimental work or clinical trials are warranted in future research to confirm whether RIC could be utilized as a non-invasive, inexpensive and efficient adjunct therapeutic intervention method for multi-organ protection.

Blood-brain Barrier Disruption May Contribute to White Matter Lesions in the Setting of Internal Jugular Venous Stenosis

BACKGROUND AND PURPOSE

Cloudy white matter lesions are associated imaging features of internal jugular venous stenosis (IJVS). However, the mechanism of the IJVS associated cloudy white matter lesions is still unclear. This study aims to evaluate blood-brain barrier integrity of the patients with IJVS.

MATERIALS AND METHODS

A total of 45 eligible patients with IJVS confirmed by computed tomography venography (CTV) and 45 healthy controls were enrolled into this study. The levels of serum MMP-9 and the markers of tight junctions, including occludin and ZO-1 obtained from IJVS patients and control group were tested by enzyme-linked immune-sorbent assay and compared.

RESULTS

Both the levels of serum MMP-9 (0.2ng/ml) and occludin (0.05ng/ml) in IJVS group were higher than in the control group (0.01ng/ml vs. 0 ng/ml, all p<0.001). While, the levels of serum ZO-1 showed no statistical significance between the two groups (0.55ng/ml vs 0.735ng/ml, P=0.34). The levels of serum MMP-9 between the subset with or without white matter lesions in IJVS group showed a significant difference (0.22 [0.06, 0.43] vs. 0.01 [0.01, 0.06], P =0.019).

CONCLUSION

BBB disruption may participate in the formation of IJVS-associated white matter lesions; the mechanism of BBB disruption may involve MMP-9 and occludin.