Changes In Vascular Permeability Research Articles

Dynamic contrast-enhanced magnetic resonance imaging may act as a biomarker for vascular damage in normal appearing brain tissue after radiotherapy in patients with glioblastoma.

BackgroundDynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising perfusion method and may be useful in evaluating radiation-induced changes in normal-appearing brain tissue.PurposeTo assess whether radiotherapy induces changes in vascular permeability (Ktrans) and the fractional volume of the extravascular extracellular space (Ve) derived from DCE-MRI in normal-appearing brain tissue and possible relationships to radiation dose given.Material and MethodsSeventeen patients with glioblastoma treated with radiotherapy and chemotherapy were included; five were excluded because of inconsistencies in the radiotherapy protocol or early drop-out. DCE-MRI, contrast-enhanced three-dimensional (3D) T1-weighted (T1W) images and T2-weighted fluid attenuated inversion recovery (T2-FLAIR) images were acquired before and on average 3.3, 30.6, 101.6, and 185.7 days after radiotherapy. Pre-radiotherapy CE T1W and T2-FLAIR images were segmented into white and gray matter, excluding all non-healthy tissue. Ktrans and Ve were calculated using the extended Kety model with the Parker population-based arterial input function. Six radiation dose regions were created for each tissue type, based on each patient’s computed tomography-based dose plan. Mean Ktrans and Ve were calculated over each dose region and tissue type.ResultsGlobal Ktrans and Ve demonstrated mostly non-significant changes with mean values higher for post-radiotherapy examinations in both gray and white matter compared to pre-radiotherapy. No relationship to radiation dose was found.ConclusionAdditional studies are needed to validate if Ktrans and Ve derived from DCE-MRI may act as potential biomarkers for acute and early-delayed radiation-induced vascular damages. No dose-response relationship was found.

Analysis of DCE-MRI for Early Prediction of Breast Cancer Therapy Response.

Positive response to neoadjuvant chemotherapy (NACT) has been correlated to better long-term outcomes in breast cancer treatment. Early prediction of response to NACT can help modify the regimen for non-responding patients, sparing them of potential toxicities of ineffective therapies. It has been observed that tumor functions such as vascularization and vascular permeability change even before noticeable changes occur in the tumor size in response to the treatment. Therefore, it is essential to have reliable imaging based features to measure these changes. Texture analysis on parametric maps from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has shown to be a good predictor of breast cancer response to NACT at an early stage. But hand crafted texture features might not be able to capture the rich spatio-temporal information in the parametric maps. In this work, we studied the ability of convolutional neural networks in predicting the response to NACT at an early stage.

DCE-MRI for Early Prediction of Response in Hepatocellular Carcinoma after TACE and Sorafenib Therapy: A Pilot Study

Objective:Dynamic contrast-enhanced MRI (DCE-MRI) can measure the changes in tumor blood flow, vascular permeability and interstitial and intravascular volume. The objective was to evaluate the efficacy of DCE-MRI in prediction of Barcelona Clinic Liver Cancer (BCLC) staging B or C hepatocellular carcinoma (HCC) response after treatment with transcatheter arterial chemoembolization (TACE) followed by sorafenib therapy.Methods:Sorafenib was administered four days after TACE of BCLC staging B or C HCC in 11 patients (21 lesions). DCE-MRI was performed with Gd-EOB-DTPA contrast before TACE and three and 10 days after TACE. DCE-MRI acquisitions were taken pre-contrast, hepatic arterial-dominant phase and 60, 120, 180, 240, 330, 420, 510 and 600 seconds post-contrast. Distribution volume of contrast agent (DV) and transfer constant Ktrans were calculated. Patients were grouped by mRECIST after one month or more post-TACE into responders (complete response, partial response) and non-responders (stable disease, progressive disease).Results:DV was reduced in responders at three and 10 days post-TACE (p = 0.008 and p = 0.008 respectively). DV fell in non-responders at three days (p = 0.025) but was not significantly changed from pre-TACE values after sorafenib. Sensitivity and specificity for DV 10 days post-TACE were 88% and 77% respectively.Conclusion:DV may be a useful biomarker for early prediction of therapeutic outcome in intermediate HCC.

The Deletion of Endothelial Sodium Channel α (αENaC) Impairs Endothelium-Dependent Vasodilation and Endothelial Barrier Integrity in Endotoxemia in Vivo.

The role of epithelial sodium channel (ENaC) activity in the regulation of endothelial function is not clear. Here, we analyze the role of ENaC in the regulation of endothelium-dependent vasodilation and endothelial permeability in vivo in mice with conditional αENaC subunit gene inactivation in the endothelium (endo-αENaCKO mice) using unique MRI-based analysis of acetylcholine-, flow-mediated dilation and vascular permeability. Mice were challenged or not with lipopolysaccharide (LPS, from Salmonella typhosa, 10 mg/kg, i.p.). In addition, changes in vascular permeability in ex vivo organs were analyzed by Evans Blue assay, while changes in vascular permeability in perfused mesenteric artery were determined by a FITC-dextran-based assay. In basal conditions, Ach-induced response was completely lost, flow-induced vasodilation was inhibited approximately by half but endothelial permeability was not changed in endo-αENaCKO vs. control mice. In LPS-treated mice, both Ach- and flow-induced vasodilation was more severely impaired in endo-αENaCKO vs. control mice. There was also a dramatic increase in permeability in lungs, brain and isolated vessels as evidenced by in vivo and ex vivo analysis in endotoxemic endo-αENaCKO vs. control mice. The impaired endothelial function in endotoxemia in endo-αENaCKO was associated with a decrease of lectin and CD31 endothelial staining in the lung as compared with control mice. In conclusion, the activity of endothelial ENaC in vivo contributes to endothelial-dependent vasodilation in the physiological conditions and the preservation of endothelial barrier integrity in endotoxemia.

Protein-bounded uremic toxin p-cresylsulfate induces vascular permeability alternations.

The goal of the present studies is to investigate that the impact of p-cresylsulfate (PCS) on the endothelial barrier integrity via in situ exposure and systemic exposure. Vascular permeability changes induced by local injection of PCS were evaluated by the techniques of both Evans blue (EB) and India ink tracer. Rats were intravenously injected with EB or India ink followed by intradermal injections of various doses of PCS (0, 0.4, 2, 10 and 50µmol/site) on rat back skins. At different time points, skin EB was extracted and quantified. The administration of India ink was used to demonstrate leaky microvessels. Skin PCS levels were also determined by liquid chromatography-mass spectrometry. We also investigated whether the increased endothelial leakage occurred in the aortic endothelium in rats treated with 5/6 nephrectomy and intraperitoneal injection of PCS 50mg/kg/day for 4weeks. The aortic endothelial integrity was evaluated by increased immunoglobulin G (IgG) leakage. High doses of PCS, but not lower doses, significantly induced vascular leakage as compared to saline injection and EB leakage exhibited in time-dependent manner. A time-correlated increase in leaky microvessels was detected in the tissues examined. The injected PCS declined with time and displayed an inverse relationship with vascular leakage. Chronic kidney disease (CKD) rats administered with PCS, compared to control rats, had significantly higher serum levels of PCS and apparent IgG deposition in the aortic intima. Increased endothelial leakage induced by PCS in skin microvessels and the aorta of CKD rats suggests that the PCS-induced endothelial barrier dysfunction.

Improved Evaluation of Antivascular Cancer Therapy Using Constrained Tracer-Kinetic Modeling for Multiagent Dynamic Contrast-Enhanced MRI.

Dynamic contrast-enhanced MRI (DCE-MRI) is a promising technique for assessing the response of tumor vasculature to antivascular therapies. Multiagent DCE-MRI employs a combination of low and high molecular weight contrast agents, which potentially improves the accuracy of estimation of tumor hemodynamic and vascular permeability parameters. In this study, we used multiagent DCE-MRI to assess changes in tumor hemodynamics and vascular permeability after vascular-disrupting therapy. Multiagent DCE-MRI (sequential injection of G5 dendrimer, G2 dendrimer, and Gd-DOTA) was performed in tumor-bearing mice before, 2 and 24 hours after treatment with vascular disrupting agent DMXAA or placebo. Constrained DCE-MRI gamma capillary transit time modeling was used to estimate flow F, blood volume fraction vb, mean capillary transit time tc, bolus arrival time td, extracellular extravascular fraction ve, vascular heterogeneity index α-1 (all identical between agents) and extraction fraction E (reflective of permeability), and transfer constant Ktrans (both agent-specific) in perfused pixels. F, vb, and α-1 decreased at both time points after DMXAA, whereas tc increased. E (G2 and G5) showed an initial increase, after which, both parameters restored. Ktrans (G2 and Gd-DOTA) decreased at both time points after treatment. In the control, placebo-treated animals, only F, tc, and Ktrans Gd-DOTA showed significant changes. Histologic perfused tumor fraction was significantly lower in DMXAA-treated versus control animals. Our results show how multiagent tracer-kinetic modeling can accurately determine the effects of vascular-disrupting therapy by separating simultaneous changes in tumor hemodynamics and vascular permeability.Significance: These findings describe a new approach to measure separately the effects of antivascular therapy on tumor hemodynamics and vascular permeability, which could help more rapidly and accurately assess the efficacy of experimental therapy of this class. Cancer Res; 78(6); 1561-70. ©2018 AACR.

The immunoproteasome subunit LMP10 mediates angiotensin II-induced retinopathy in mice

Inflammation has been implicated in a variety of retinal diseases. The immunoproteasome plays a critical role in controlling inflammatory responses, but whether activation of immunoproteasome contributes to angiotensin II (Ang II)-induced retinopathy remains unclear. Hypertensive retinopathy (HR) was induced by infusion of Ang II (3000 ng/kg/min) in wild-type (WT) and immunoproteasome subunit LMP10 knockout (KO) mice for 3 weeks. Changes in retinal morphology, vascular permeability, superoxide production and inflammation were examined by pathological staining. Our results showed that immunoproteasome subunit LMP10 expression and its trypsin-like activity were significantly upregulated in the retinas and serum of Ang II-infused mice and in the serum from patients with hypertensive retinopathy. Moreover, Ang II-infused WT mice showed an increase in the central retinal thickness, vascular permeability, reactive oxygen species (ROS) production and inflammation compared with saline controls, and these effects were significantly attenuated in LMP10 KO mice, but were aggravated in mice intravitreally injected with rAAV2-LMP10. Interestingly, administration of IKKβ specific inhibitor IMD-0354 remarkably blocked an Ang II-induced increase in vascular permeability, oxidative stress and inflammation during retinopathy. Mechanistically, Ang II-induced upregulation of LMP10 promoted PTEN degradation and activation of AKT/IKK signaling, which induced IkBα phosphorylation and subsequent degradation ultimately leading to activation of NF-kB target genes in retinopathy. Therefore, this study provided novel evidence demonstrating that LMP10 is a positive regulator of NF-kB signaling, which contributes to Ang II-induced retinopathy. Strategies for inhibiting LMP10 or IKKβ activity in the eye could serve as a novel therapeutic target for treating hypertensive retinopathy.

Photoacoustic imaging of tumour vascular permeability with indocyanine green in a mouse model

BackgroundWe analysed the haemodynamics of indocyanine green (ICG) in mouse organs and tumours and evaluated responses to anti-angiogenic agents in an allograft tumour mouse model by photoacoustic imaging.MethodsThirty-six male mice (aged 10–14 weeks; body weight 20–25 g) were used. Real-time photoacoustic imaging of organs and tumours after intravenous injection of ICG was conducted in mice until 10 min after ICG injection. ICG distribution in tumour tissues was assessed by immunohistochemical staining and observation of ICG-derived fluorescence. Vascular permeability changes induced by the vascular endothelial growth factor (VEGF)-blocking agent VEGF-trap on tumour photoacoustic signals were studied.ResultsThe photoacoustic signals in salivary glands and tumours after intravenous injection of iCG (0.604 ± 0.011 and 0.994 ± 0.175 [mean ± standard deviation], respectively) were significantly increased compared with those in the liver, kidney, and great vessel (0.234 ± 0.043, 0.204 ± 0.058 and 0.127 ± 0.040, respectively; p < 0.010). In tumours, the photoacoustic signal increased within 30 s after ICG injection in a dose-dependent manner (r2 = 0.899) and then decreased gradually. ICG was found to extravasate in tumour tissues. In VEGF-trap-treated mice, the photoacoustic signal in the tumour decreased at the early phase before inhibition of tumour growth was detected (0.297 ± 0.052 vs 1.011 ± 0.170 in the control; p < 0.001).ConclusionsPhotoacoustic imaging with ICG administration demonstrated extravasation of ICG in mouse organs and tumours, indicating the potential for early detection of changes in vascular permeability during cancer therapy.

Vitamin D3 Protects against Diabetic Retinopathy by Inhibiting High-Glucose-Induced Activation of the ROS/TXNIP/NLRP3 Inflammasome Pathway.

Purpose This study aimed to evaluate the mechanisms underlying the effects of 1,25-dihydroxyvitamin D (vitamin D3) on diabetes-induced retinal vascular damage and retinal vascular endothelial cell apoptosis. Methods Diabetic and control rats were randomly assigned to receive vitamin D3 or vehicle for 6 months. Additionally, human retinal microvascular endothelial cells (HRMECs) were incubated in normal or high-glucose medium with or without vitamin D3. Morphological changes in retinal tissues and retinal vascular permeability were examined, and cellular apoptosis was detected by fluorescence staining. Intracellular reactive oxygen species (ROS) levels were determined using fluorescent probes. Proteins were examined by Western blotting. Results Vitamin D3 significantly downregulated intracellular ROS and inhibited TRX-interacting protein (TXNIP)/NOD-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome pathway activation. Additionally, vitamin D3 reduced vascular endothelial growth factor (VEGF) expression and the Bax/Bcl-2 ratio. These changes were associated with retinal recovery and with decreases in retinal vascular permeability and retinal capillary cell apoptosis. Conclusions Vitamin D3 decreases diabetes-induced ROS and exerts protective effects against retinal vascular damage and cell apoptosis in association with inhibition of the ROS/TXNIP/NLRP3 inflammasome pathway. Understanding the mechanisms of action of vitamin D3 has important implications for preventing and treating inflammatory-related illnesses such as diabetic retinopathy.

Interleukin-6 promotes a sustained loss of endothelial barrier function via Janus kinase-mediated STAT3 phosphorylation and de novo protein synthesis.

Vascular leakage is a hallmark of the inflammatory response. Acute changes in endothelial permeability are due to posttranslational changes in intercellular adhesion and cytoskeleton proteins. However, little is known about the mechanisms leading to long-term changes in vascular permeability. Here, we show that interleukin-6 (IL-6) promotes an increase in endothelial monolayer permeability that lasts over 24 h and demonstrate that activation of Src and MEK/ERK pathways is required only for short-term increases in permeability, being dispensable after 2 h. In contrast, Janus kinase (JAK)-mediated STAT3 phosphorylation at Y705 (but not S727) and de novo synthesis of RNA and proteins are required for the sustained permeability increases. Loss of junctional localization of VE-cadherin and ZO-1 is evident several hours after the maximal IL-6 response, thus suggesting that these events are a consequence of IL-6 signaling, but not a cause of the increased permeability. Understanding the mechanisms involved in sustaining vascular permeability may prove crucial to allow us to directly target vascular leakage and minimize tissue damage, thus reducing the rates of mortality and chronic sequelae of excessive edema. Targeting endothelial-specific mechanisms regulating barrier function could provide a new therapeutic strategy to prevent vascular leakage while maintaining the immune response and other beneficial aspects of the inflammatory response that are required for bacterial clearance and tissue repair.

Reversible Electroporation-Mediated Liposomal Doxorubicin Delivery to Tumors Can Be Monitored With 89Zr-Labeled Reporter Nanoparticles.

Reversible electroporation (RE) can facilitate nanoparticle delivery to tumors through direct transfection and from changes in vascular permeability. We investigated a radiolabeled liposomal nanoparticle (89Zr-NRep) for monitoring RE-mediated liposomal doxorubicin (DOX) delivery in mouse tumors. Intravenously delivered 89Zr-NRep allowed positron emission tomography imaging of electroporation-mediated nanoparticle uptake. The relative order of 89Zr-NRep injection and electroporation did not result in significantly different overall tumor uptake, suggesting direct transfection and vascular permeability can independently mediate deposition of 89Zr-NRep in tumors. 89Zr-NRep and DOX uptake correlated well in both electroporated and control tumors at all experimental time points. Electroporation accelerated 89Zr-NRep and DOX deposition into tumors and increased DOX dosing. Reversible electroporation–related vascular effects seem to play an important role in nanoparticle delivery to tumors and drug uptake can be quantified with 89Zr-NRep.

The EPAC–Rap1 pathway prevents and reverses cytokine-induced retinal vascular permeability

Increased retinal vascular permeability contributes to macular edema, a leading cause of vision loss in eye pathologies such as diabetic retinopathy, age-related macular degeneration, and central retinal vein occlusions. Pathological changes in vascular permeability are driven by growth factors such as VEGF and pro-inflammatory cytokines such as TNF-α. Identifying the pro-barrier mechanisms that block vascular permeability and restore the blood-retinal barrier (BRB) may lead to new therapies. The cAMP-dependent guanine nucleotide exchange factor (EPAC) exchange-protein directly activated by cAMP promotes exchange of GTP in the small GTPase Rap1. Rap1 enhances barrier properties in human umbilical endothelial cells by promoting adherens junction assembly. We hypothesized that the EPAC-Rap1 signaling pathway may regulate the tight junction complex of the BRB and may restore barrier properties after cytokine-induced permeability. Here, we show that stimulating EPAC or Rap1 activation can prevent or reverse VEGF- or TNF-α-induced permeability in cell culture and in vivo Moreover, EPAC activation inhibited VEGF receptor (VEGFR) signaling through the Ras/MEK/ERK pathway. We also found that Rap1B knockdown or an EPAC antagonist increases endothelial permeability and that VEGF has no additive effect, suggesting a common pathway. Furthermore, GTP-bound Rap1 promoted tight junction assembly, and loss of Rap1B led to loss of junctional border organization. Collectively, our results indicate that the EPAC-Rap1 pathway helps maintain basal barrier properties in the retinal vascular endothelium and activation of the EPAC-Rap1 pathway may therefore represent a potential therapeutic strategy to restore the BRB.

A Rat Model of Hemorrhagic Shock for Studying Vascular Hyperpermeability.

Vascular hyperpermeability is one of the known detrimental effects of hemorrhagic shock, which we continually try to understand, minimize, and reverse. Here, we describe induction of hemorrhagic shock in a rat and studying of its effects on vascular permeability, using intravital microscopy. In this protocol, hemorrhagic shock will be induced by withdrawing blood to reduce the mean arterial pressure (MAP) to 40mmHg for 60min followed by resuscitation for 60min. To study the changes in vascular permeability following hemorrhagic shock, the rats will be given FITC-albumin, a fluorescent tracer, intravenously. Following this, the FITC-albumin flux across the vessel will be measured in mesenteric postcapillary venules by determining fluorescent intensity intravascularly and extravascularly under intravital microscopy.

Macular thickness in healthy controls and diabetics without diabetic macular edema

Aim of the Study: This study aims to evaluate the thickness of the macula in patients with diabetes but without diabetic macular edema (DME) using optical coherence tomography (OCT) and compare these findings with measurements from normal controls which may be useful for early detection of macular thickening. Patients and Methods: Two hundred subjects were included and divided into 4 equal groups: normal controls, diabetics without diabetic retinopathy (DR), diabetics with NPDR and without DME, and diabetics with PDR and without DME. Full ophthalmological evaluation was done and the fast macular OCT scan was done that divides the macula into 9 sectors. The mean ± standard deviation of macular thicknesses by area were analyzed and compared. Results: A central subfield (CS) was statistically significantly thicker in normal controls compared to diabetics with no DR with no significant difference in other sectors. Furthermore, all of the inner sectors (IS, IN, IT, II) and the ON sector were significantly thicker in normal compared to diabetics with nonproliferative DR (NPDR) group with no significant difference in other sectors. Furthermore, between all sectors except IS and IT on comparing normal versus diabetics with PDR, between nasal sectors (IN and ON) but not in other sectors on comparing diabetics with no DR versus diabetics with NPDR, between all sectors except IS on comparing diabetics with no DR versus diabetics with PDR, and between all sectors on comparing diabetics with NPDR versus diabetics with PDR. Conclusion: This study found that the fovea and perifoveal subfields of the ETDRS grid tended to be thinner in diabetics without DR than in healthy controls and still thinner in eyes with DR, but thicker in eyes with PDR than in healthy controls thus confirming that the loss of neural tissue begins in the early stages of diabetes. As diabetes develops, neurodegeneration may be masked by changes in vascular permeability that cause thickening of the retinal layers.

Retinal malperfusion in albuminuric Type 1 diabetes mellitus patients without clinical signs of diabetic retinopathy: a prospective pilot study

BackgroundTo report fluorescein angiography findings in a group of albuminuric Type 1 diabetes mellitus (T1DM) patients without diabetic retinopathy.MethodsFifteen albuminuric T1DM patients with normal/near normal estimated glomerular filtration rate without diabetic retinopathy underwent fluorescein angiography; presence of microaneurysms, vascular permeability changes and retinal malperfusion were evaluated.ResultsFluorescein angiography revealed microaneurysms, blood-retinal barrier breakdown and retinal ischemia in 10 (67%) and 11 (73%); 8 (53%) and 9 (60%); 2 (13%) and 5 (33%) of patients at baseline and follow up, respectively. Follow up time averaged 24.6 months, minimum follow up time was 20 months. Patients who presented retinal malperfusion had higher HbA1C and lower estimated glomerular filtration rate.ConclusionsMost albuminuric T1DM patients with a normal fundus exam had angiographic signs of diabetic retinopathy, some presenting retinal malperfusion. Retinal changes may be found with more sensitive testing in these patients, especially with impaired estimated glomerular filtration rate, even if the fundus exam is normal, and fluorescein angiography should be considered. These findings point to a homogenous presentation of the diabetic microangiopathies.

Endothelial dysfunction and mechanobiology in pathological cutaneous scarring: lessons learned from soft tissue fibrosis.

Hypertrophic scars/keloids are pathogenic scars that are characterized by collagen and fibroblast accumulation. The endothelia in the lesions are mechanosensitive and participate actively in the pathogenesis of these scars. The present review summarizes how endothelium responds to mechanical stimuli such as shear, stretch and hydrostatic pressure. It also shows that in heart, liver, kidney and lung fibrosis, endothelial dysfunctions (EDs) associate with changes in vascular tone, endothelial permeability, coagulation and vasomodulation that result in inflammation, hypertension and coagulation. Pathological scars exhibit similar EDs during their development and progression. Mechanopharmaceutical or mechanotherapeutic interventions that rescue EDs may be useful scar treatments.

Prostaglandin E1 Protects the Peripheral Nerve in Diabetics through Preventing Vascular Permeability Changes.

The aims of this study were to investigate the effects of the vasodilator prostaglandin E1 on microvascular permeability, the expression of vascular endothelial growth factor (VEGF), as well as the structural and functional changes of the peripheral nerve in diabetic rats. Streptozotocin-induced diabetes mellitus were randomly divided into two groups and intraperitoneally received, once daily, an injection of prostaglandin E1 at 1.6 μg/kg in normal saline or the same volume of normal saline (diabetic control), respectively. Six rats were randomly selected as normal controls. Diabetic controls exhibited a significant increase in the tail flick threshold temperature, water content of the sciatic nerve, serum VEGF level, and VEGF level in the sciatic nerve; in addition, a decrease in the sciatic nerve conduction velocity (NCV) was observed, compared with normal rats (P<0.01). Treatment with prostaglandin E1 resulted in similar changes but at a slower rate than in those without treatment. Diabetic control rats also showed histological and ultrastructural abnormalities of the sciatic nerve, whereas prostaglandin E1-treated rats exhibited similar but less severe injury. The serum VEGF level was negatively correlated with the sciatic NCV (r=-0.932, P<0.01) and positively correlated with the tail flick threshold temperature (r=0.835, P<0.01) as well as the water content of the sciatic nerve (r=0.901, P<0.01). Prostaglandin E1 could protect the peripheral nerve by improving sciatic nerve function, reducing the VEGF level, and decreasing the vascular permeability. This study provides an experimental proof that prostaglandin E1 has potential benefits in improving DPN in early stage.

The effect of heparin on vascular endothelial cell injury induced by lipopolysaccharide in rats and the study of nuclear factor-κB, interleukin-1β, interleukin-6, tumor necrosis factor-α

Objective To investigate the effect of heparin on vascular endothelial cell injury induced by lipopolysaccharide in rats, and the changes of the levels of nuclear factor-κB (NF-κB), interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α. Methods 90 SD rats were randomly divided into three groups: LPS group, heparin group and control group, 30 rats in each group. Rats in the LPS group and heparin group were injected with 10 mg/kg by intraperitoneal injection of lipopolysaccharide solution to establish sepsis model. The heparin group was injected with 300 IU/kg heparin solution before 1H injection. Rats in control group were injected with NaCl solution by intraperitoneal injection in accordance with 10 mg/kg. The morphological changes of lung tissue in rats at 6 h were compared. The changes of NF-κB, IL-1β, IL-6, TNF-α in three groups were detected by enzyme linked immunosorbent assay. The pulmonary vascular permeability changes of rats were detected by Evans blue (EB). Results In Lipopolysaccharide group and heparin group 0 h to 6 h nf-kappa B significantly increased activity of lipopolysaccharide group by 0 h (2.51±0.49) U/L up to 6 h (18.85±2.97) U/L, heparin group by 0 h (2.39±0.34) U/L up to 6 h (3.37±0.82) U/L, lipopolysaccharide group nf-kappa B increased activity levels compared with heparin group is more significant (P=0.021); 6 to 12 h h two groups the nf-kappa B activity significantly decreased (P<0.05), of which the lipopolysaccharide group by 0 h (18.85±2.97) U/L fell to 6 h (13.47±2.19) U/L (P=0.022), heparin group by 0 h (3.37±0.82) U/L fell to 6 h (2.25±0.34) U/L (P=0.048), but it is still significantly higher than the control group, and 0 h level (P=0.000); 0 h three groups of blood beta, IL-6, IL-1β, TNF-α level difference was not significant (IL-1 beta: P=0.940; IL-6: P=0.626; TNF-α: P=0.948), and 0 h to 6 h, lipopolysaccharide group and heparin group rats each index in the blood rise rapidly (within the group, compared with 0 h, 6 h, lipopolysaccharide group, IL-1β: P=0.039; IL-6: P=0.018; TNF-α: P=0.000; heparin group, IL-1β: P=0.036; IL-6: P=0.036; TNF-α: P=0.012), the index level significantly dropped 12 h (comparison group, compared with 6 h, lipopolysaccharide group, IL-1 beta: P=0.042; IL-6: P=0.027; TNF-α: P=0.008; heparin group, IL-1β: P=0.047; IL-6: P=0.045; TNF-α: P=0.034). Lipopolysaccharide group 6 h and 12 h of the blood of rats beta, IL-6, IL-1 TNF-αlevel was significantly higher than that of heparin group (lipopolysaccharide group: heparin group, 6 h, IL-1β: P=0.031; IL-6: P=0.023; TNF-α: P=0.000; 12 h, IL-1β: P=0.046; IL-6: P=0.038; TNF-α: P=0.017). (3) the contents of rat lung EN heparin [(1.21±0.18) mg/ml], and significantly lower than the lipopolysaccharide group [(1.92±0.20) mg/ml] (t=-8.344, P=0.000). Conclusion The heparin can inhibit the damage of vascular endothelial cells by inhibiting the levels of NF-κB, IL-1β, IL-6 , TNF-α in sepsis rats, and thus play an anti-inflammatory role in sepsis. Key words: Heparin; Lipopolysaccharide; Sepsis; Vascular endothelial cell injury

Abstract 4074: Permeability changes and effect of chemotherapy in brain adjacent to tumor in an experimental model of brain metastases of breast cancer

Abstract Background: Brain metastases vasculature is compromised and more permeable than that of vasculature in normal brain. Unfortunately, little is known about vascular permeability changes in brain adjacent to tumor (BAT). It is critical to understand the potential changes as chemotherapy penetration and accumulation brain tumors positively correlate with breakdown of the brain vasculature. Herein, we evaluate quantitatively measure permeability, drug accumulation and cytotoxicity in normal brain that is adjacent (&amp;lt;500 microns) to a tumor. Methods: The subclone population of brain seeking metastatic breast cancer cells (MDA-MB-231Br) were injected into the left ventricle of female NuNu mice. Mice were given a chemotherapeutic regimen of vinorelbine (10mg/kg), erubilin (1.5mg/kg) or docetaxel (10mg/kg). Progression occurred until neurological compromise was noted, at which time animals were injected with texas red 625 Da(TR) and texas red dextran 3kDa (TRD). Dye concentrations (measuring passive permeability changes) were determined in lesions and the BAT using quantitative fluorescent microscopy. Chemotherapeutic induced cytotoxicity was observed by staining for activated astrocytes and DNA damage in neurons, glia and endothelia. Results: We observed permeability of TR is highly heterogeneous both within and between the tumors (normal brain Kin TR: 1.2 x10-5)with 2-40-fold increase in permeability over normal brain region. TR concentrations in BAT (100µm from tumor edge) is consistently 40% of the tumor but significantly higher than that of normal brain and TR permeability in BAT increased 1-2.5-fold over normal brain. The permeability of TRD in tumor increased 2.7- 8.4-fold over normal brain, whereas in BAT, the permeability increased 1-1.6-fold over normal brain. We also observed animals treated with chemotherapy showed activated astrocytes in BAT, along with some cellular death. In vehicle treated animals there were little activated astrocytes and little cell death in the BAT. Conclusions: Our data suggests that the tracer and drugs accumulate in regions around tumors in the brain which result in neurotoxic changes. Citation Format: Afroz Shareef Mohammad, Chris E. Adkins, Neal Shah, Rawaa Aljammal, Jessica Griffith, Paul R. Lockman. Permeability changes and effect of chemotherapy in brain adjacent to tumor in an experimental model of brain metastases of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4074. doi:10.1158/1538-7445.AM2017-4074

Safety and efficiency of active immunization with detoxified antigen against scorpion venom: side effect evaluation.

The efficiency and safety of vaccine are the most important properties, however, as any medication, it can induce side effects. This prophylactic therapy could be used to prevent the lethal and pathophysiological effects induced after scorpion envenomation. In this study, detoxified venom associated to alum adjuvant (V*alum) is used as a vaccine against scorpion venom for immunization of mice. We evaluate the safety and the inflammatory response of this vaccine. We also investigated the protective effect of this formulation against the toxicity of native Androctonus australis hector venom. Results showed no adverse events occurred after immunization of animals. This active immunization of animals did not cause change in vascular permeability, no edema formation in the studied organs. Furthermore, there are no IgE production in sera, nor change in the morphology of the mast cells in skin tissues. However, low inflammatory response triggered by activating the recruitment of eosinophils associated to IL-4 and IL-5 release was observed. All immunized animals are protected from the toxic effects of native venom until 6 LD50 and to 7 LD50 after the second challenge. This safe vaccine preparation seems to induce a long-term protection without any risk of deleterious inflammatory response.