Analysis of arterial intimal hyperplasia: review and hypothesis

Recent advances in microneedles for enhanced functional angiogenesis and vascular drug delivery

Many therapeutic applications use the transdermal method to avoid the severe restrictions associated with oral medication delivery. Given the limitations of traditional drug delivery via skin, transdermal microneedle (MN) arrays have been reported to be versatile and very efficient devices due to their outstanding characteristics such as painless penetration, affordability, excellent medicinal efficacy, and relative safety. MNs have recently received increased attention for their ability to cure vascular illnesses such as hypertension and thrombosis, as well as promote wound healing via the angiogenesis impact. The integrant of method manufacturing and biodegradable material allows for the modification of MN form and drug release pattern, hence increasing the flexibility of such drug delivery. In this review, we focused on recent improvements in MN-mediated transdermal administration of protein and peptide medicines for improved functional angiogenesis and vascular therapy. We also provide an overview of the present applications of MNs-mediated transdermal protein and peptide administration, particularly in the realm of vascular system disease therapy. Finally, the current state of clinical translation and a forecast for future progress are provided.

Magnolia kobus DC. suppresses neointimal hyperplasia by regulating ferroptosis and VSMC phenotypic switching in a carotid artery ligation mouse model

BACKGROUND

Magnolia kobus DC (MO), as a plant medicine, has been reported to have various physiological activities, including neuroprotective, anti-inflammatory, and anti-diabetic effects. However, vascular protective effects of MO remain incompletely understood. In this study, we evaluated the vascular protective effect of MO against ferroptosis in a carotid artery ligation (CAL)-induced neointimal hyperplasia mouse model and in aortic thoracic smooth muscle A7r5 cells.

METHODS

This study was conducted to estimate the vascular protective effects of MO by systematically measuring histopathological analysis and western blot analysis in CAL animal model. In vitro protective effects of MO were evaluated by estimating cell viability, reactive oxygen species (ROS) content, glutathione (GSH) levels, lipid peroxidation, mitochondrial morphological change, cell proliferation, migration, western blot analysis, and qRT-PCR against erastin (Era)-induced A7r5 cells.

RESULTS

MO intake significantly improved neointimal formation, inhibited ferroptosis and vascular smooth muscle cell (VSMC) phenotypes, and ameliorated the antioxidant system of carotid artery tissues. In addition, MO treatment effectively ameliorated Era-induced ferroptotic cytotoxicity, including cellular death, ROS production, and cell migration status. MO treatment also suppressed proliferation and migration in Era-induced A7r5 cells. MO considerably regulated Era-induced abnormal mechanisms related to ferroptotic changes, VSMC phenotype switching, and the ROS scavenging system in A7r5 cells.

CONCLUSION

MO has the potential for use as a functional food supplement, nutraceutical, or medicinal food, with protective effects on vascular health by regulating ferroptosis and VSMC phenotypic switching.

The Vascular Response After Balloon Angioplasty of Infrapopliteal Intermediate Stenosis Evaluated by Optical Frequency Domain Imaging

BACKGROUND

We often experience worsening of stenosis by balloon angioplasty of infrapopliteal (IP) lesion compared with the initial stenosis. However, reports on this phenomenon are limited.

AIMS

The main purpose of this study is to evaluate vascular response after balloon angioplasty of IP artery stenosis.

METHODS

Thirteen patients (15 arteries) who underwent endovascular treatment (EVT) and follow-up angiography with optical frequency domain imaging (OFDI) of intermediate IP stenosis were included. Serial OFDI images at 3 time points (before and after EVT and at follow-up) were analyzed. Diameter and area of external elastic lamina, internal elastic lamina, and lumen were measured, and plaque area and plaque burden (PB) were calculated. PB before EVT was classified into mild, moderate, and severe by 0%-20%, 21%-40%, and 41%-60%, respectively.

RESULTS

Analyzed were 229 cross sections. External elastic lamina diameter did not change significantly among three time points (3.8 ± 0.5 [95% confidence interval (CI): 3.7 to 3.9] mm, 3.9 ± 0.4 [95% CI: 3.8 to 4.0] mm, 3.9 ± 0.4 [95% CI: 3.8 to 4.0] mm, p = 0.06). Lumen area increased after EVT but became smaller at follow-up than before EVT (4.5 ± 1.5 [95% CI: 4.3 to 4.7] mm2, 5.3 ± 1.3 [95% CI: 5.1 to 5.5] mm2, 3.7 ± 1.2 [95% CI: 3.5 to 3.9] mm2, p < 0.001). Plaque area became smaller after EVT and larger at follow-up than before EVT (3.0 ± 1.7 [95% CI: 2.8 to 3.2] mm2, 2.4 ± 1.5 [95% CI: 2.2 to 2.6] mm2, 4.0 ± 1.6 [95% CI: 3.8 to 4.2] mm2, p < 0.001). Lumen area was significantly smaller at follow-up than before EVT in mild and moderate PB groups, but it was not different in severe PB group (mild PB group: 5.1 ± 1.5 [95% CI: 4.7 to 5.5] mm2 vs. 4.0 ± 1.3 [95% CI: 3.7 to 4.3] mm2, p < 0.001, moderate PB group: 4.6 ± 1.3 [95% CI: 4.4 to 4.8] mm2 vs. 3.6 ± 1.2 [95% CI: 3.4 to 3.8] mm2, p < 0.001, severe PB group: 3.0 ± 1.4 [95% CI: 2.5 to 3.5] mm2 vs. 3.1 ± 1.0 [95% CI: 2.7 to 3.5] mm2, p = 0.93).

CONCLUSIONS

Balloon angioplasty of intermediate IP artery stenosis with mild or moderate PB led to smaller lumen area at follow-up than before EVT.

The rejection that defies antirejection drugs-chronic vascular rejection (allograft vasculopathy): The role of terminology and linguistic relativity

While allograft loss due to acute rejection has been dramatically reduced due to the introduction of immunophilins, this therapy has little effect on allografts lost due to chronic vascular rejection. This situation may be due to a misnomer of the pathology. Specifically, its designation as 'chronic rejection' has given the wrong impression that the cause of the disease has been identified. Analyzing this phenomenon under the rubric of linguistic relativity suggests that the words chosen to name the disease may have restricted our cognitive ability to solve the problem. Thus, we have to step out of the 'alloimmunity/rejection box'. Let's pause between our words, Speak and fall silent again, So that the meaning of the word just spoken, Sounds a clearer echo in our heads. Let's pause between our words. Andrey Makarevich.

Vascular Reconstruction of Multiple Renal Arteries-A Risk Factor for Transplant Renal Artery Stenosis: Insight From a Matched Case-Control Study

Transplant Renal Artery Stenosis (TRAS) is the leading vascular complication following kidney transplantation (KT), causing premature allograft loss and increased post-KT mortality. While risk factors for TRAS, such as prolonged cold ischemia time and delayed graft function, are well-documented in deceased donor-KT, the risk factors remain less clearly defined in living donor-KT. This matched case-control study, conducted at a leading national transplant center predominantly performing living donor-KT, evaluated risk factors and long-term outcomes of clinical TRAS (cTRAS). cTRAS cases diagnosed from January 2009 to December 2022 were matched with four control kidney transplant recipients (KTRs) in a study powered to assess whether ex-vivo arterial vascular reconstruction of multiple renal arteries (VR-MRA) increases the risk of cTRAS. Among 2,454 KTs, 28 KTRs (1.14%) were diagnosed with cTRAS around 3.62 ± 1.04 months post-KT, with renal allograft dysfunction (92.86%) as the most common presenting feature. Notably, 27 cTRAS cases were successfully treated with endovascular intervention, yielding favorable outcomes over a 6-180 months follow-up period. The study identified ex-vivo VR-MRA as an independent risk factor for cTRAS (P < 0.001). cTRAS cases receiving timely treatment exhibited long-term outcomes in graft and patient survival similar to control KTRs. Early screening and timely intervention for cTRAS post-KT may improve graft and patient outcomes.

Performance of drug-coated balloons in coronary and below-the-knee arteries: Anatomical, physiological and pathological considerations

Below-the-knee (infrapopliteal) atherosclerotic disease, which presents as chronic limb-threatening ischemia (CLTI) in nearly 50% of patients, represents a treatment challenge when it comes to the endovascular intervention arm of management. Due to reduced tissue perfusion, patients usually experience pain at rest and atrophic changes correlated to the extent of the compromised perfusion. Unfortunately, the prognosis remains unsatisfactory with 30% of patients requiring major amputation and a mortality rate of 25% within 1 year. To date, randomized multicentre trials of endovascular intervention have shown that drug-eluting stents (DES) increase patency rate and lower target lesion revascularization rate compared to plain balloon angioplasty and bare-metal stents. The majority of these trials recruited patients with focal infrapopliteal lesions, while most patients requiring endovascular intervention have complex and diffuse atherosclerotic disease. Moreover, due to the nature of the infrapopliteal arteries, the use of long DES is limited. Following recent results of drug-coated balloons (DCBs) in the treatment of femoropopliteal and coronary arteries, it was hoped that similar effective results would be achieved in the infrapopliteal arteries. In reality, multicentre trials have failed to support the proposed hypothesis and no advantage was found in using DCBs in comparison to plain balloon angioplasty. This review aims to explore anatomical, physiological and pathological differences between lesions of the infrapopliteal and coronary arteries to explain the differences in outcome when using DCBs.

The incidence rate and histological characteristics of intimal hyperplasia in elastase-induced experimental abdominal aortic aneurysms in mice

Intimal hyperplasia (IH) is a negative vascular remodeling after arterial injury. IH occasionally occurs in elastase-induced abdominal aortic aneurysm (AAA) mouse models. This study aims to clarify the incidence and histological characteristics of IH in aneurysmal mice. A retrospective study was conducted by including 42 male elastase-induced mouse AAA models. The IH incidence, aortic diameters with or without IH, and hyperplasia lesional features of mice were analyzed. Among 42 elastase-induced AAA mouse models, 10 mice developed mild IH (24%) and severe IH was found in only 2 mice (5%). The outer diameters of the AAA segments in mice with and without IH did not show significant difference. Both mild and severe IH lesions show strong smooth muscle cell positive staining, but endothelial cells were occasionally observed in severe IH lesions. There was obvious macrophage infiltration in the IH lesions of the AAA mouse models, especially in mice with severe IH. However, only a lower numbers of T cells and B cells were found in the IH lesion. Local cell-secreted matrix metalloproteinases (MMP) 2 was highly expressed in all IH lesions, but MMP9 was only overexpressed in severe lesions. In conclusion, this study is the first to demonstrate the occurrence of aneurysmal IH and its histological characteristics in an elastase-induced mouse AAA model. This will help researchers better understand this model, and optimize it for use in AAA-related research.

Methyl donor diet attenuates intimal hyperplasia after vascular injury in rats

Environmental factors, particularly dietary habits, play an important role in cardiovascular disease susceptibility and progression through epigenetic modification. Previous studies have shown that hyperplastic vascular intima after endarterectomy is characterized by genome-wide hypomethylation. The purpose of this study was to investigate whether methyl donor diet affects intimal hyperplasia and the possible mechanisms involved. Intimal hyperplasia was induced in SD rats by carotid artery balloon injury. From 8 d before surgery to 28 d after surgery, the animals were fed a normal diet (ND) or a methyl donor diet (MD) supplemented with folic acid, vitamin B12, choline, betaine, and zinc. Carotid artery intimal hyperplasia was observed by histology, the effect of MD on carotid protein expression was analyzed by proteomics, functional clustering, signaling pathway, and upstream-downstream relationship of differentially expressed proteins were analyzed by bioinformatics. Results showed that MD attenuated balloon injury-induced intimal hyperplasia in rat carotid arteries. Proteomic analysis showed that there were many differentially expressed proteins in the common carotid arteries of rats fed with two different diets. The differentially expressed proteins are mainly related to the composition and function of the extracellular matrix (EMC), and changes in the EMC can lead to vascular remodeling by affecting fibrosis and stiffness of the blood vessel wall. Changes in the levels of vasculotropic proteins such as S100A9, ILF3, Serpinh1, Fbln5, LOX, HSPG2, and Fmod may be the reason why MD attenuates intimal hyperplasia. Supplementation with methyl donor nutrients may be a beneficial measure to prevent pathological vascular remodeling after injury.

Platelet-Rich Plasma in Dermatology: New Insights on the Cellular Mechanism of Skin Repair and Regeneration

The skin's recognised functions may undergo physiological alterations due to ageing, manifesting as varying degrees of facial wrinkles, diminished tautness, density, and volume. Additionally, these functions can be disrupted (patho)physiologically through various physical and chemical injuries, including surgical trauma, accidents, or chronic conditions like ulcers associated with diabetes mellitus, venous insufficiency, or obesity. Advancements in therapeutic interventions that boost the skin's innate regenerative abilities could significantly enhance patient care protocols. The application of Platelet-Rich Plasma (PRP) is widely recognized for its aesthetic and functional benefits to the skin. Yet, the endorsement of PRP's advantages often borders on the dogmatic, with its efficacy commonly ascribed solely to the activation of fibroblasts by the factors contained within platelet granules. PRP therapy is a cornerstone of regenerative medicine which involves the autologous delivery of conditioned plasma enriched by platelets. This is achieved by centrifugation, removing erythrocytes while retaining platelets and their granules. Despite its widespread use, the precise sequences of cellular activation, the specific cellular players, and the molecular machinery that drive PRP-facilitated healing are still enigmatic. There is still a paucity of definitive and robust studies elucidating these mechanisms. In recent years, telocytes (TCs)-a unique dermal cell population-have shown promising potential for tissue regeneration in various organs, including the dermis. TCs' participation in neo-angiogenesis, akin to that attributed to PRP, and their role in tissue remodelling and repair processes within the interstitia of several organs (including the dermis), offer intriguing insights. Their potential to contribute to, or possibly orchestrate, the skin regeneration process following PRP treatment has elicited considerable interest. Therefore, pursuing a comprehensive understanding of the cellular and molecular mechanisms at work, particularly those involving TCs, their temporal involvement in structural recovery following injury, and the interconnected biological events in skin wound healing and regeneration represents a compelling field of study.

The CathPilot: Performance Validation and Preclinical Safety and Feasibility Assessment

OBJECTIVES

Peripheral endovascular revascularization procedures often fail due to technical limitations of guidewire support, steering, and visualization. The novel CathPilot catheter aims to address these challenges. This study assesses the safety and feasibility of the CathPilot and compares its performance to conventional catheters for peripheral vascular interventions.

METHODS

The study compared the CathPilot to non-steerable and steerable catheters. The success rates and access times for a relevant target inside a tortuous vessel phantom model were assessed. The reachable workspace within the vessel and the guidewire's force delivery capabilities were also evaluated. To validate the technology, chronic total occlusion tissue samples were used ex vivo to compare crossing success rates with conventional catheters. Finally, in vivo experiments in a porcine aorta were conducted to evaluate safety and feasibility.

RESULTS

The success rates for reaching the set targets were 31%, 69%, and 100% with the non-steerable catheter, the steerable catheter, and the CathPilot, respectively. CathPilot had a significantly larger reachable workspace, and allowed for up to four times higher force delivery and pushability. In crossing of chronic total occlusion samples, the CathPilot achieved a success rate of 83% and 100%, for fresh and fixed lesions respectively, which was also significantly higher than conventional catheters. The device was fully functional in the in vivo study, and there were no signs of coagulation or damage to the vessel wall.

CONCLUSION

This study shows the safety and feasibility of the CathPilot system and its potential to reduce failure and complication rates in peripheral vascular interventions. The novel catheter outperformed conventional catheters in all defined metrics. This technology can potentially improve the success rate and outcome of peripheral endovascular revascularization procedures.

In silico experiments of intimal hyperplasia development: disendothelization in an axisymmetric idealized artery

We use in silico experiments to study the role of the hemodynamics and of the type of disendothelization on the physiopathology of intimal hyperplasia. We apply a multiscale bio-chemo-mechanical model of intimal hyperplasia on an idealized axisymmetric artery that suffers two kinds of disendothelizations. The model predicts the spatio-temporal evolution of the lesions development, initially localized at the site of damages, and after few days displaced downstream of the damaged zones, these two stages being observed whatever the kind of damage. Considering macroscopic quantities, the model sensitivity to pathology-protective and pathology-promoting zones is qualitatively consistent with experimental findings. The simulated pathological evolutions demonstrate the central role of two parameters: (a) the initial damage shape on the morphology of the incipient stenosis, and (b) the local wall shear stresses on the overall spatio-temporal dynamics of the lesion.

Inflachromene inhibits intimal hyperplasia through the HMGB1/2- regulated TLR4-NF-κB pathway

The contractile-syntheticphenotypicconversion of vascular smooth muscle cells (VSMCs) plays a key role in atherosclerosis, vascular restenosis, and hypertension. Our previous study explored the correlation between high mobility group box protein (HMGB) 1 and HMGB2 and neointimal hyperplasia after vascular injury. In the present study, we explore whether inflachromene (ICM), a novel inhibitor of the expression of both HMGB1 and HMGB2, modulates phenotypic changes in VSMCs and the mechanisms involved. Mice treated with ICM after carotid artery wire injury showed a decrease in excessive neointimal hyperplasia compared with that in the vehicle groups. In cultured VSMCs, pretreatment with ICM suppressed the angiotensin II (Ang II)-induced phenotypic conversion, proliferation, and migration. We discovered that ICM reduced the Ang II-induced upregulation of the expression of HMGB1 and HMGB2 and inhibited their shuttling between the nucleus and the cytosol. Mechanistically, Ang II-treated VSMCs exhibited higher levels of Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) phosphorylation, which were attenuated by ICM. In addition, the NF-κB inhibitor Bay-117082 abolished the recombinant HMGB1-mediated VSMC phenotypic conversion, proliferation, and migration. Furthermore, ICM ameliorated the Ang II-induced increases in NAD[P]H oxidase expression, thereby attenuating the Ang II-induced proliferation and migration. These results reveal that ICM pretreatment attenuates Ang II-induced VSMC dedifferentiation, proliferation, and migration may by regulating the TLR4-NF-kB pathway. Thus, ICM is a potential therapy and preventive treatment for vascular proliferative diseases.

And don't forget your anti in-stent stenosis pill! Commentary on 'Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device' by Flores-Milan et al

In their INR study, Flores-Milan et al. present a retrospective single-centre study that aimed to investigate and determine some of the factors associated with in-stent stenosis (ISS) after intracranial aneurysm (IA) embolization using a commercially available flow diverter stent (FD). The retrospective analyses included ruptured and unruptured intracranial aneurysms treated with standalone flow diverter stent implantation or initial coil obliteration with the FD device placed subsequently two weeks after initial treatment. The article's methodology was carefully tailored to demystify the unknown pathophysiological mechanism behind the entity of interest called in-stent stenosis. Study outcomes also included angiographic evaluation of aneurysm occlusion thrombotic and hemorrhagic events. The authors reported excellent technical and clinical results altogether. The achieved angiographic occlusion rates resonate with the current obliteration results reported in the literature. Mortality and morbidity are congruent with previously published results and were 5.3% and 1.1%, respectively.

Experimental Protocol and Phantom Design and Development for Performance Characterization of Conventional Devices for Peripheral Vascular Interventions

Conventional catheter-based interventions for treating peripheral artery disease suffer high failure and complication rates. The mechanical interactions with the anatomy constrain catheter controllability, while their length and flexibility limit their pushability. Also, the 2D X-ray fluoroscopy guiding these procedures fails to provide sufficient feedback about the device location relative to the anatomy. Our study aims to quantify the performance of conventional non-steerable (NS) and steerable (S) catheters in phantom and ex vivo experiments. In a 10 mm diameter, 30 cm long artery phantom model, with four operators, we evaluated the success rate and crossing time in accessing 1.25 mm target channels, the accessible workspace, and the force delivered through each catheter. For clinical relevance, we evaluated the success rate and crossing time in crossing ex vivo chronic total occlusions. For the S and NS catheters, respectively, users successfully accessed 69 and 31% of the targets, 68 and 45% of the cross-sectional area, and could deliver 14.2 and 10.2 g of mean force. Using a NS catheter, users crossed 0.0 and 9.5% of the fixed and fresh lesions, respectively. Overall, we quantified the limitations of conventional catheters (navigation, reachable workspace, and pushability) for peripheral interventions; this can serve as a basis for comparison with other devices.

DN200434 Inhibits Vascular Smooth Muscle Cell Proliferation and Prevents Neointima Formation in Mice after Carotid Artery Ligation

BACKGRUOUND

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs), which contributes to the development of occlusive vascular diseases, requires elevated mitochondrial oxidative phosphorylation to meet the increased requirements for energy and anabolic precursors. Therefore, therapeutic strategies based on blockade of mitochondrial oxidative phosphorylation are considered promising for treatment of occlusive vascular diseases. Here, we investigated whether DN200434, an orally available estrogen receptor-related gamma inverse agonist, inhibits proliferation and migration of VSMCs and neointima formation by suppressing mitochondrial oxidative phosphorylation.

METHODS

VSMCs were isolated from the thoracic aortas of 4-week-old Sprague-Dawley rats. Oxidative phosphorylation and the cell cycle were analyzed in fetal bovine serum (FBS)- or platelet-derived growth factor (PDGF)-stimulated VSMCs using a Seahorse XF-24 analyzer and flow cytometry, respectively. A model of neointimal hyperplasia was generated by ligating the left common carotid artery in male C57BL/6J mice.

RESULTS

DN200434 inhibited mitochondrial respiration and mammalian target of rapamycin complex 1 activity and consequently suppressed FBS- or PDGF-stimulated proliferation and migration of VSMCs and cell cycle progression. Furthermore, DN200434 reduced carotid artery ligation-induced neointima formation in mice.

CONCLUSION

Our data suggest that DN200434 is a therapeutic option to prevent the progression of atherosclerosis.

Mechanical and Structural Adaptation of the Pulmonary Root after Ross Operation in a Murine Model

Background: The major limitation to the Ross operation is a progressive autograft dilation, possibly leading to reoperations. A murine model was created to evaluate pulmonary artery graft (PAG) adaptation to pressure overload. Methods: Lewis rats (n = 17) underwent heterotopic surgical implantation of a PAG, harvested from syngeneic animals (n = 17). A group of sham animals (n = 7) was used as a control. Seriated ultrasound studies of the PAG were performed. Animals were sacrificed at 1 week (n = 5) or 2 months (n = 15) and the PAG underwent mechanical and histopathological analyses. Results: Echography showed an initial increase in diameter (p < 0.001) and a decrease in peak systolic velocity (PSV). Subsequently, despite no change in diameter, an increase in PSV was observed (p < 0.01). After 1 week, the stiffness of the PAG and the aorta were similar, while at 2 months, the PAG appeared more rigid (p < 0.05). PAG’s histological analysis at 2 months revealed intimal hyperplasia development. The tunica media showed focal thinning of the elastic lamellae and normally distributed smooth muscle cells. Conclusions: We demonstrated a stiffening of the PAG wall after its implantation in systemic position; the development of intimal hyperplasia and the thinning of the elastic lamellae could be the possible underlying mechanism.

Heterogeneous Maturation of Arterio-Venous Fistulas and Loop-Shaped Venous Interposition Grafts: A Histological and 3D Flow Simulation Comparison

Vascular graft maturation is associated with blood flow characteristics, such as velocity, pressure, vorticity, and wall shear stress (WSS). Many studies examined these factors separately. We aimed to examine the remodeling of arterio-venous fistulas (AVFs) and loop-shaped venous interposition grafts, together with 3D flow simulation. Thirty male Wistar rats were randomly and equally divided into sham-operated, AVF, and loop-shaped venous graft (Loop) groups, using the femoral and superficial inferior epigastric vessels for anastomoses. Five weeks after surgery, the vessels were removed for histological evaluation, or plastic castings were made and scanned for 3D flow simulation. Remodeling of AVF and looped grafts was complete in 5 weeks. Histology showed heterogeneous morphology depending on the distribution of intraluminal pressure and WSS. In the Loop group, an asymmetrical WSS distribution coincided with the intima hyperplasia spots. The tunica media was enlarged only when both pressure and WSS were high. The 3D flow simulation correlated with the histological findings, identifying “hotspots” for intimal hyperplasia formation, suggesting a predictive value. These observations can be useful for microvascular research and for quality control in microsurgical training.

Impact of extra-anatomical bypass on coarctation fluid dynamics using patient-specific lumped parameter and Lattice Boltzmann modeling

Accurate hemodynamic analysis is not only crucial for successful diagnosis of coarctation of the aorta (COA), but intervention decisions also rely on the hemodynamics assessment in both pre and post intervention states to minimize patient risks. Despite ongoing advances in surgical techniques for COA treatments, the impacts of extra-anatomic bypass grafting, a surgical technique to treat COA, on the aorta are not always benign. Our objective was to investigate the impact of bypass grafting on aortic hemodynamics. We investigated the impact of bypass grafting on aortic hemodynamics using a patient-specific computational-mechanics framework in three patients with COA who underwent bypass grafting. Our results describe that bypass grafting improved some hemodynamic metrics while worsened the others: (1) Doppler pressure gradient improved (decreased) in all patients; (2) Bypass graft did not reduce the flow rate substantially through the COA; (3) Systemic arterial compliance increased in patients #1 and 3 and didn't change (improve) in patient 3; (4) Hypertension got worse in all patients; (5) The flow velocity magnitude improved (reduced) in patient 2 and 3 but did not improve significantly in patient 1; (6) There were elevated velocity magnitude, persistence of vortical flow structure, elevated turbulence characteristics, and elevated wall shear stress at the bypass graft junctions in all patients. We concluded that bypass graft may lead to pseudoaneurysm formation and potential aortic rupture as well as intimal hyperplasia due to the persistent abnormal and irregular aortic hemodynamics in some patients. Moreover, post-intervention, exposures of endothelial cells to high shear stress may lead to arterial remodeling, aneurysm, and rupture.

MED1 Deficiency in Macrophages Accelerates Intimal Hyperplasia via ROS Generation and Inflammation

Mediator complex subunit 1 (MED1) is a component of the mediator complex and functions as a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Previously, we showed that MED1 in macrophages has a protective effect on atherosclerosis; however, the effect of MED1 on intimal hyperplasia and mechanisms regulating proinflammatory cytokine production after macrophage MED1 deletion are still unknown. In this study, we report that MED1 macrophage-specific knockout (MED1 ^ΔMac) mice showed aggravated neointimal hyperplasia, vascular smooth muscle cells (VSMCs), and macrophage accumulation in injured arteries. Moreover, MED1 ^ΔMac mice showed increased proinflammatory cytokine production after an injury to the artery. After lipopolysaccharide (LPS) treatment, MED1 ^ΔMac macrophages showed increased generation of reactive oxygen species (ROS) and reduced expression of peroxisome proliferative activated receptor gamma coactivator-1α (PGC1α) and antioxidant enzymes, including catalase and glutathione reductase. The overexpression of PGC1α attenuated the effects of MED1 deficiency in macrophages. In vitro, conditioned media from MED1 ^ΔMac macrophages induced more proliferation and migration of VSMCs. To explore the potential mechanisms by which MED1 affects inflammation, macrophages were treated with BAY11-7082 before LPS treatment, and the results showed that MED1 ^ΔMac macrophages exhibited increased expression of phosphorylated-p65 and phosphorylated signal transducer and activator of transcription 1 (p-STAT1) compared with the control macrophages, suggesting the enhanced activation of NF-κB and STAT1. In summary, these data showed that MED1 deficiency enhanced inflammation and the proliferation and migration of VSMCs in injured vascular tissue, which may result from the activation of NF-κB and STAT1 due to the accumulation of ROS.

MicroRNA-375-3p is implicated in carotid artery stenosis by promoting the cell proliferation and migration of vascular smooth muscle cells

Background

Atherosclerosis is the main cause of carotid artery stenosis (CAS) which mostly occurs in the elderly. In this paper, the expression level of miR-375-3p in asymptomatic CAS patients and its diagnostic value for asymptomatic CAS were investigated, and the effects of miR-375-3p on the cell proliferation and migration of vascular smooth muscle cells (VSMCs) was further explored.

Methods

98 healthy subjects and 101 asymptomatic CAS patients were participated in this study. qRT-PCR was used to measure the expression level of serum miR-375-3p, and the ROC curve was established to evaluate the predictive value of miR-375-3p for asymptomatic CAS. After transfection with miR-375-3p mimic or inhibitor in vitro, cell proliferation and migration were detected by CCK-8 assay, colony formation assay, and Transwell assay, respectively. The levels of TNF-α, IL-1β, IL-6 were detected by ELISA. Western blot was used to detect the protein expression of XIAP. Finally, luciferase reporter gene assay was applied to assess the interaction of miR-375-3p with target genes.

Results

The expression level of serum miR-375-3p in asymptomatic CAS patients was significantly higher than that in healthy controls, and the AUC value of ROC curve was 0.888. The sensitivity and specificity were 80.2 and 86.7%, respectively, indicating that miR-375-3p had high diagnostic value for asymptomatic CAS. In vitro cell experiments showed that up-regulation of miR-375-3p significantly promoted the proliferation and migration of VSMCs, and also promoted the generation of inflammatory factors and phenotypic transformation of VSMCs. Luciferase reporter gene assay confirmed that XIAP was a target gene of miR-375-3p and was negatively regulated by miR-375-3p.

Conclusions

In this study, miR-375-3p may have a clinical diagnostic value for asymptomatic CAS patients which need further validation. Increased miR-375-3p levels in CAS may be associated with increased proliferation and migration of VSMCs via downregulation of the apoptosis inducing gene XIAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02326-6.

Microneedle-mediated therapy for cardiovascular diseases

Cardiovascular diseases remain a leading cause of global disease burden. To date, the limited drug delivery efficacy confines the therapeutic effect in most conventional approaches, such as intramyocardial injections and vascular devices, due to short-term drug release and low retention within the disease sites. As a typical transdermal medical device with a minimally invasive manner and controlled/sustained drug release pattern, microneedles have gained momentum in the field of cardiovascular therapy, from which several cardiovascular diseases have been benefited to the ultimate therapeutic effects. In this concise review, strategies based on the microneedles for the treatments of cardiovascular diseases are introduced, mainly focus on hypertension, atherosclerosis, thrombus, and myocardial diseases. The limitations at the present stage and perspectives of the next-generation microneedles for cardiovascular therapy are also discussed.

Gut micobiota alteration by Lactobacillus rhamnosus reduces pro-inflammatory cytokines and glucose level in the adult model of Zebrafish

Objective

Type 2 diabetes mellitus (T2DM) is still a challenge for physicians to manage patient’s circumstances. It is assumed that alterations in the normal flora may be involved in the pathogenesis of T2DM through inducing chronic inflammation. To investigate the effect of Lactobacillus rhamnosus as a common probiotic on T2DM, we induced an experimental model of T2DM in adult male Zebrafish by gradient hyper-glucose accumulation methodology.

Results

In this trial 3-month old male adult Zebrafish were divided in to four groups including two control groups and T2DM induced groups with or without probiotic treatment. After 5 days of acclimation, T2DM was induced by a gradient hyper-glucose accumulation methodology. Diabetic fishes had statistically abnormal blood glucose and pro-inflammatory cytokine levels compared to control group (p = 0.0001). These results suggest that probiotic intervention decreased the blood glucose level in the T2DM-P group by decreasing pro-inflammatory cytokines responsible for signaling in T2DM therapeutic modalities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-021-05706-5.

Using the novel pelvic organ prolapse histologic quantification system to identify phenotypes in uterosacral ligaments in women with pelvic organ prolapse

BACKGROUND

Pelvic organ prolapse is common, but the underlying etiologies are poorly understood, which limits our current prevention and treatment options.

OBJECTIVE

Our primary objective was to compare the uterosacral ligament histologic features in women with and without prolapse using the novel pelvic organ prolapse histologic quantification system. Our secondary aim was to determine whether composite histologic findings in uterosacral ligaments are associated with prolapse risk factors.

STUDY DESIGN

This was a prospective cohort study in which paracervical uterosacral ligament biopsies were performed at the time of hysterectomy for primary prolapse or other benign gynecologic indications and processed for histologic evaluation. The pelvic organ prolapse quantification system was used to determine the prolapse stage. In this study, 9 prominent histologic features were semiquantitatively scored using the pelvic organ prolapse histologic quantification system in a blinded fashion and compared between prolapse and control groups. Unbiased principal component analysis of these scores was independently performed to identify potential relationships between histologic measures and prolapse risk factors.

RESULTS

The histologic scores of 81 prolapse and 33 control ligaments were analyzed. Compared with the control group, women in the prolapse group were significantly older and more likely to be in the menopausal phase. There was no difference in the number of vaginal deliveries, body mass index, hormone use, or smoking status between the groups. To control for baseline differences, patients were also stratified by age over 40 years and menopausal status. Compared with the control group, the prolapse ligaments in the premenopausal group had significantly more loss of smooth muscle fibers within the fascicles (P<.001), increased inflammatory infiltrates of neutrophils within the tissue and perineural inflammatory cells (P<.01 and P=.04, respectively), and reduced neointimal hyperplasia (P=.02). Prolapse ligaments in the postmenopausal group exhibited elevated adipose content compared with that of the control group (P=.05). Amount of fibrillar collagen, total nonvascular smooth muscle, and muscle fiber vesicles of prolapse ligaments did not differ in either the premenopausal or postmenopausal group compared with that of the control group. Unbiased principal component analysis of the histologic scores separated the prolapse ligaments into 3 phenotypes: (1) increased adipose accumulation, (2) increased inflammation, and (3) abnormal vasculature, with variable overlap with controls. Posthoc analysis of these subgroups demonstrated a positive correlation between increasing number of vaginal deliveries and body mass index with increasing adipose content in the adipocyte accumulation and inflammatory phenotype and increasing neointimal hyperplasia in the vascular phenotype. However, only the relationship between vaginal delivery and adipocytes was significant in the adipose phenotype (R²=0.13; P=.04).

CONCLUSION

Histologic phenotypes exist in pelvic support ligaments that can be distinguished using the pelvic organ prolapse histologic quantification system and principle component analysis. Vaginal delivery is associated with aberrant adipose accumulation in uterosacral ligaments. Our findings support a multifactorial etiology for pelvic organ prolapse contributing to altered smooth muscle, vasculature, and connective tissue content in crucial pelvic support structures. To confirm these associations and evaluate the biomechanical properties of histologic phenotypes of prolapse, larger studies are warranted. Closing this gap in knowledge will help optimize personalized medicine and help identify targets for prevention and treatment of this complex condition.

Micro-Rheological Changes of Red Blood Cells in the Presence of an Arterio-Venous Fistula or a Loop-Shaped Venous Graft in the Rat

Introduction: In case of kidney failure, hemodialysis is the primary kidney replacement technique. Several vascular access methods used for the therapy, one of which is the arterio-venous fistula (AVF). In the AVF, the blood flow is altered, which can elevate the mechanical stress on the red blood cells (RBCs). This can affect the RBC hemorheological properties, and it can further cause systemic changes. To lower the turbulence and shear stress, we performed a loop-shaped arterio-arterial venous interposition graft (loop-shaped graft) to compare its effect to the conventional AVF. Materials and Methods: Thirty male Wistar were used (permission registration Nr.: 25/2016/UDCAW). The animals were randomly divided into sham-operated, AVF, and loop groups (n = 10/each). The superficial inferior epigastric vein (SIEV) was used to create the AVF and the loop-shaped graft. Blood samples were taken before/after the surgery and at the 1st, 3rd, and 5th postoperative weeks. We measured hemorhelogical, hematological, and blood gas parameters. The microcirculation of the hind limbs was also monitored using Laser Doppler fluxmetry. Results: Hematocrit, RBC count, and hemoglobin decreased by the 1st postoperative week. The erythrocyte aggregation values significantly increased in the fistula group by the 5th week (6.43 ± 2.31 vs. 13.60; p < 0.0001; vs. before operation). At the postoperative 1st week in the loop group, the values showed a significant decrease in RBC deformability. During the maturation period, dominantly at the 5th week, all values were normalized. The operated hind limb's skin microcirculation significantly increased in the sham and loop group by the 1st week (39 ± 10.57 vs. 73.93 ± 1.97 BFU, p < 0.01). This increase wasn't observed in the fistula group probably due to a steal-effect. Conclusion: Unlike in the loop group, in the presence of the fistula, several rheological parameters have changed. The loop-shaped graft had only minimal impact on micro-rheological parameters.

MicroRNA-503-5p improves carotid artery stenosis by inhibiting the proliferation of vascular smooth muscle cells

Carotid artery stenosis (CAS) is a common arteriosclerotic vascular disease affected by vascular smooth muscle cells (VSMCs). The aim of the present study was to investigate the expression and diagnostic value of microRNA (miR)-503-5p in asymptomatic patients with CAS and to further explore the effect of miR-503-5p on VSMC proliferation. The levels of miR-503-5p in the serum of 62 asymptomatic patients with CAS and 60 healthy controls were detected by reverse transcription-quantitative PCR. The association between miR-503-5p and the clinical characteristics of the patients was analyzed using the χ² test. A receiver operating characteristic curve was drawn to evaluate the diagnostic value of miR-503-5p to distinguish asymptomatic patients with CAS from healthy controls. Finally, miR-503-5p inhibitors and mimics were transfected into VSMCs in vitro to detect the effect of miR-503-5p on the proliferation ability through Cell Counting Kit-8 assays. The serum levels of miR-503-5p in asymptomatic patients with CAS were significantly reduced as compared with those in healthy individuals. The expression levels of miR-503-5p were significantly associated with diabetes and arterial stenosis. Furthermore, the area under the ROC curve was 0.817, the specificity was 79.03% and the sensitivity was 83.30%, which proved that miR-503-5p had a high diagnostic accuracy in patients with CAS. Finally, the in vitro proliferation assay indicated that overexpression of miR-503-5p significantly inhibited the proliferation of VSMCs. In conclusion, miR-503-5p is a potential diagnostic biomarker for asymptomatic CAS and overexpression of miR-503-5p may inhibit the proliferation of VSMCs and improve CAS.

Pathogenesis of atherosclerosis in the tunica intima, media, and adventitia of coronary arteries: An updated review

Atherosclerosis is a chronic inflammatory disease of arteries and it affects the structure and function of all three layers of the coronary artery wall. Current theories suggest that the dysfunction of endothelial cells is one of the initial steps in the development of atherosclerosis. The view that the tunica intima normally consists of a single layer of endothelial cells attached to the subendothelial layer and internal elastic membrane has been questioned in recent years. The structure of intima changes with age and it becomes multilayered due to migration of smooth muscle cells from the media to intima. At this stage, the migration and proliferation of smooth muscle cells do not cause pathological changes in the intima. The multilayering of intima is classically considered to be an important stage in the development of atherosclerosis, but in fact atherosclerotic plaques develop only focally due to the interplay of various processes that involve the resident and invading inflammatory cells. The tunica media consists of multiple layers of smooth muscle cells that produce the extracellular matrix, and this layer normally does not contain microvessels. During the development of atherosclerosis, the microvessels from the tunica adventitia or from the lumen may penetrate thickened media to provide nutrition and oxygenation. According to some theories, the endothelial dysfunction of these nutritive vessels may significantly contribute to the atherosclerosis of coronary arteries. The adventitia contains fibroblasts, progenitor cells, immune cells, microvessels, and adrenergic nerves. The degree of inflammatory cell infiltration into the adventitia, which can lead to the formation of tertiary lymphoid organs, correlates with the severity of atherosclerotic plaques. Coronary arteries are surrounded by perivascular adipose tissue that also participates in the atherosclerotic process.

Design and characterization of a porous pouch to prevent peritoneal adhesions during in vivo vascular graft maturation

Vein grafts for coronary artery bypass are not available in more than 30% of patients due to prior use or systemic vascular diseases. Tissue engineered vascular grafts (TEVGs) have shown promise, but intimal hyperplasia and graft thrombosis are still concerns when grafted in small-diameter arteries. In this study, we utilized the peritoneal cavity as an "in vivo" bioreactor to recruit autologous cells to electrospun conduits enclosed within porous pouches to improve the response after grafting. Specifically, we designed a new poly (ethylene glycol)-based pouch to avoid adhesion to the peritoneal wall and still allow the necessary peritoneal fluid to reach the enclosed conduit. The pouch mechanics in compression and bending were determined through experiments and finite element simulations to optimize the pouch design. This included poly (ethylene glycol) concentration, pore density, and pouch size. We demonstrated that the optimized pouch was able to withstand the estimated forces applied in the rat peritoneal cavity and it allowed maturation of the enclosed electrospun conduit. This pouch significantly reduced peritoneal adhesion formation compared to polytetrafluoroethylene pouches that have been used previously, which overcomes this potential limitation to clinical translation. After aortic grafting of pre-conditioned conduits, patent grafts with limited intimal hyperplasia were observed. Overall, this study demonstrated a new pouch design that allows the in vivo bioreactor strategy to be used for vascular tissue engineering without the potential side effect of peritoneal adhesion formation.

Nutritional Considerations for Peripheral Arterial Disease: A Narrative Review

Those with peripheral arterial disease (PAD) require important considerations with respect to food and nutrition, owing to advanced age, poor diet behaviours and immobility associated with the disease process and co-morbid state. These considerations, coupled with the economic effectiveness of medical nutrition therapy, mandate that dietetic care plays a vital role in the management of PAD. Despite this, optimising dietetic care in PAD remains poorly understood. This narrative review considers the role of medical nutrition therapy in every stage of the PAD process, ranging from the onset and initiation of disease to well established and advanced disease. In each case, the potential benefits of traditional and novel medical nutrition therapy are discussed.

First Report of Edge Vascular Response at 12 Months of Magmaris, A Second-Generation Drug-Eluting Resorbable Magnesium Scaffold, Assessed by Grayscale Intravascular Ultrasound, Virtual Histology, and Optical Coherence Tomography. A Biosolve-II Trial Sub-Study

INTRODUCTION AND OBJECTIVE

The edge vascular response (EVR) remains unknown in second generation drug-eluting Resorbable Magnesium Scaffold (RMS), such as Magmaris. The aim of the study was to evaluate tissue modifications in the RMS edges over time, assessed by different invasive imaging modalities.

METHODS

The patients treated with the device were assessed by optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS at baseline and 12 months. The EVR study performed a segment- and frame-level analysis of the 5 mm segments proximal and distal of the actual RMS.

RESULTS

The segment-level grayscale IVUS (n = 10), virtual histology IVUS (n = 10), and OCT (n = 18) analysis did not show any significant changes after 12 months, except for a fibrous plaque area (FPA) reduction of 0.5mm² (p = 0.017) in the proximal segment compared to baseline. In the frame-level analysis, IVUS evaluation revealed a vessel area decreased 2.80 ± 1.43 mm² (p = 0.012) and 2.49 ± 1.53 mm² (p = 0.022) in 2 proximal frames. This was accompanied by plaque area reduction of 0.88 ± 0.70 mm² (p = 0.048) and a FPA decreased by 0.63 ± 0.48 mm² (p = 0.004) in one proximal frame. In 1 distal frame, there was a dense calcium area reduction of 0.10 ± 0.12 mm² (p = 0.045), FPA and fibrous fatty plaque increased 0.54 ± 0.53 mm² (p = 0.023) and 0.17 ± 0.16 mm² (p = 0.016), respectively. By OCT, there was a lumen area decrease of 0.76 ± 1.51 mm² (p = 0.045) in a distal frame.

CONCLUSION

At 12 months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment. This could be translated as a benign healing process at the edges of the RMS.

SUMMARY

The edge vascular response (EVR) remains unknown in second generation drug-eluting absorbable metal scaffolds (RMS), such as Magmaris. Patients treated with the device were assessed by multi invasive imaging modalities [i.e. optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS] evaluating the tissue changes over time in the segment- and frame-level analysis of the 5 mm segments proximal and distal of the actual RMS. As a result, after 12 months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment, translating a benign healing process at the edges of the RMS.

Natural remodeling of the distal anastomosis of an above-knee femoropopliteal bypass depicted by CT angiography of lower limbs improves geometry of the reconstruction

The geometry of the distal anastomosis of a femoropopliteal bypass influences local hemodynamics and formation of intimal hyperplasia. We hypothesized that the distal anastomosis of an above-knee femoropopliteal bypass undergoes remodeling that results in displacement of the original course of the popliteal artery and change in the anastomosis angle. We identified 43 CT angiography examination with proximal femoropopliteal bypass and either a preserved contralateral popliteal artery or previous CTA before construction of the bypass for comparison. In these examinations, we measured the displacement distance and angle at the level of the distal anastomosis and compared these measurements with clinical and imaging data. The displacement distance was 8.8+/-4.9 mm (P<0.0001) and the displacement angle was -1° (IQR=44°). The angle between the inflow and outflow artery was 153+/-16° (P<0.0001). There was a negative association between the displacement angle and the angle between the bypass and the outflow artery (r=-0.318, P=0.037). Patients with reversed venous grafts had a greater displacement of the anastomosis (14.7+/-3.0 mm) than patients with prosthetic grafts (8.0+/-4.5 mm, P=0.0011). We conclude that construction of a distal anastomosis of proximal femoropopliteal bypass results in displacement of the original course of the popliteal artery towards the bypass and this effect is more pronounced in reversed venous grafts.

Platelet Aggregability as a Predictor of Restenosis Following Carotid Endarterectomy

BACKGROUND

Antiplatelet drugs are administered before and after carotid endarterectomies (CEAs), but their efficacy for preventing restenosis remains unclear. Hence, this study aimed to identify associations between postoperative restenosis and platelet aggregability in CEA patients.

METHODS

Thirty-six consecutive CEA patients treated at Tokyo Women's Medical University from May 2013 to March 2015 were included in this retrospective study. Restenosis was defined as a stenosis ratio greater than or equal to 50% per the European Carotid Surgery Trial criteria or peak systolic velocity of 150 cm/s on carotid ultrasound. Platelet aggregability was measured turbidimetrically using a light-transmission platelet aggregometer and analyzed in terms of aggregation profiles for 2 concentrations of collagen used to induce aggregation (.25 and 2.0 μg/mL). Patients were automatically divided into 9 classes (Class 1-9, from the lowest to the highest aggregability) using a software program according to area under their platelet aggregation curves. Each class was subdivided into 10 further gradations for a total of 90 possible scores (10-99) using a software program. Patients were divided into high- and low-platelet aggregability score groups (cut-off = 49).

RESULTS

Data were analyzed for 36 of the 99 patients. Restenosis was observed in 10 (28%) patients. Restenosis incidence was significantly higher in patients with high-platelet aggregability score than in those with low-platelet aggregability score (50.0% [7/14] versus 13.6% [3 of 22]: P = .0176, odds ratio = 6.34, 95% CI: 1.27-31.57).

CONCLUSIONS

Platelet aggregability is a useful metric for predicting and preventing restenosis after CEA. It has potential as an indicator for determining the optimal dose of antiplatelet drugs.

Plant-Derived Products for Treatment of Vascular Intima Hyperplasia Selectively Inhibit Vascular Smooth Muscle Cell Functions

Natural products are used widely for preventing intimal hyperplasia (IH), a common cardiovascular disease. Four different cells initiate and progress IH, namely, vascular smooth muscle, adventitial and endothelial cells, and circulation or bone marrow-derived cells. Vascular smooth muscle cells (VSMCs) play a critical role in initiation and development of intimal thickening and formation of neointimal hyperplasia. In this review, we describe the different originating cells involved in vascular IH and emphasize the effect of different natural products on inhibiting abnormal cellular functions, such as VSMC proliferation and migration. We further present a classification for the different natural products like phenols, flavonoids, terpenes, and alkaloids that suppress VSMC growth. Abnormal VSMC physiology involves disturbance in MAPKs, PI3K/AKT, JAK-STAT, FAK, and NF-κB signal pathways. Most of the natural isolate studies have revealed G1/S phase of cell cycle arrest, decreased ROS production, induced cell apoptosis, restrained migration, and downregulated collagen deposition. It is necessary to screen optimal drugs from natural sources that preferentially inhibit VSMC rather than vascular endothelial cell growth to prevent early IH, restenosis following graft implantation, and atherosclerotic diseases.

Arterial stiffness alone does not explain arteriovenous fistula outcomes

INTRODUCTION

Marked arterial adaptation is critical in permitting and sustaining the increased blood flow within an arteriovenous fistula (AVF). The aim of this investigation was to evaluate markers of arterial disease and their association with the early post-operative AVF outcomes.

METHODS

We included all patients in whom an AVF had been performed after enrolment to the Renal Impairment In Secondary Care (RIISC) study. Primary AVF failure (PFL) was defined as thrombosis at six-week review. All patients underwent BP Tru and Vicorder pulse wave analysis assessments and also had assays of advanced glycation end-products prior to AVF formation. These were correlated with the short-term AVF outcomes.

RESULTS

One hundred and eight AVFs were created in 86 patients. The primary patency (PPT) group were found to have significantly higher body mass index (BMI) (p = 0.01). Intraluminal vein diameter was significantly greater in the PPT group than the PFL group (p≤0.01). Mean augmentation index and augmentation index 75 was significantly higher in the PPT group than the PFL group (p = 0.03 and 0.03, respectively). Aortic pulse wave velocity was slower in the PPT group at 10.2 m/s than the PFL group at 10.8 m/s (p = 0.32). Advanced glycation end-product measurements did not vary significantly between the PPT and PFL groups (p = 0.4). Logistic regression analysis provided a predictive model, which demonstrated a predictive value of 78.1% for AVF patency at 6 weeks.

CONCLUSIONS

All patients in this end-stage renal disease cohort have significant aortic stiffness. The results for pulse wave velocity were slower in the PPT group suggesting a tendency towards stiffer vessels and PFL.

Effects of arterial blood on the venous blood vessel wall and differences in percentages of lymphocytes and neutrophils between arterial and venous blood

Vascular sclerosis mostly occurs in arteries and is mainly related to anatomic structure and hemodynamics of artery. This study aimed to investigate effects of arterial blood on vein wall and explore differences of composition between arterial and venous blood.Ultrasound was used to examine the distal venous structure of arteriovenous fistula in uremia patients. Immunohistochemistry was used to study the pathology of the distal vein. Twelve patients were divided into control group and trial group. Patients received an arteriovenous fistula within 1 month in control group. Patients had undergone this surgery ≥2 years before in the trial group. Blood samples were collected from the aortic, arterial, and venous vessels of 51 patients who had taken coronary angiography and analyzed with blood routine rest, biochemical, and immunological measures to compare the differences of blood composition between artery and vein. This study was registered with the China Clinical Trial Center website under registration number ChiCTR-OOC-16008085.In the trial group, the vascular wall of distal veins of fistula were thickened and hardened. No significant differences of blood composition were found between the aortic and radial arterial blood. However, the differences in the percentages of lymphocytes and neutrophils between arterial and venous blood were significant (Pa = .0095, Pb = .01).Under smooth hemodynamic conditions, arterial blood caused hardening of the venous wall. Arterial and venous blood differed in the percentage of lymphocyte and neutrophils. This may contribute to the vascular sclerosis that is observed in arteries more often than veins.

Characterization of a multiple particle delivery complex and determination of cellular photodamage in skin fibroblast and breast cancer cell lines

Zinc metallized Phthalocyanine (ZnPcS_mix ), a potent photosensitizer, is conjugated to gold dendrimer encapsulated nanoparticles (AuDENPs) in order to improve the efficacy of photodynamic therapy (PDT) using MCF-7 breast cancer cells and WS1 fibroblast cells as a control. Both ZnPcS_mix and AuDENPs are mixed in a nitrogen atmosphere for 48 hours and characterization analysis conducted using ultraviolet-visible (UV-vis) spectrometry for spectral properties, transmission electron microscopy (TEM) for morphological features and zeta potential measurement for surface stability and size distribution of the compound obtained or of the multiple particles delivery complex (MPDC). Cell viability, proliferation and membrane damage following PDT are assessed by the trypan blue exclusion test, adenosine triphosphate luminescence and lactate dehydrogenase cytotoxicity assays, respectively. Stable MPDCs are spherical shaped with a diameter lesser than 5 nm, and have a maximum absorption peak at 676 nm. The MPDC-mediated PDT induces a decrease in cell viability and proliferation, and increased membrane damage or cytotoxicity. The conjugation enhances the therapeutic efficiency of PDT by improving drug delivery and targeting of MCF-7 cancer cells.

Engineering Cardiovascular Implant Surfaces to Create a Vascular Endothelial Growth Microenvironment

Cardiovascular disease (CVD) is generally accepted as the leading cause of morbidity and mortality worldwide, and an increasing number of patients suffer from atherosclerosis and thrombosis annually. To treat these disorders and prolong the sufferers' life, several cardiovascular implants have been developed and applied clinically. Nevertheless, thrombosis and hyperplasia at the site of cardiovascular implants are recognized as long-term problems in the practice of interventional cardiology. Here, we start this review from the clinical requirement of the implants, such as anti-hyperplasia, anti-thrombosis, and pro-endothelialization, wherein particularly focus on the natural factors which influence functional endothelialization in situ, including the healthy smooth muscle cells (SMCs) environment, blood flow shear stress (BFSS), and the extracellular matrix (ECM) microenvironment. Then, the currently available strategies on surface modification of cardiovascular biomaterials to create vascular endothelial growth microenvironment are introduced as the main topic, e.g., BFSS effect simulation by surface micro-patterning, ECM rational construction and SMCs phenotype maintain. Finally, the prospects for extending use of the in situ construction of endothelial cells growth microenvironment are discussed and summarized in designing the next generation of vascular implants.

The Ratio of Diameters Between the Target Artery and the Bypass Modifies Hemodynamic Parameters Related to Intimal Hyperplasia in the Distal End-to-Side Anastomosis

Hemodynamics in the distal end-to-side anastomosis is related to early development of intimal hyperplasia and bypass failure. In this study we investigated the effect of diameter ratios between the target artery and the bypass at three different angles of the connection. The pulsatile flow field was visualized using particle image velocimetry in transparent models with three different angles of the connection (25°, 45°, 60°) and the diameter ratio between the bypass and the target artery was 4.6 mm : 6 mm, 6 mm : 6 mm, and 7.5 mm : 6 mm. Six parameters including location and oscillation of the stagnation point, local energy dissipation, wall shear stress (WSS), oscillatory shear index, spatial and temporal gradient of WSS and their distribution in the target artery were calculated from the flow field. In the wider bypass, the stagnation point oscillated in a greater range and was located more proximal to the anastomosis. Energy dissipation was minimal in a wider bypass with a more acute angle. The maximum WSS values were tree times greater in a narrow bypass and concentrated in a smaller circular region at the floor of the anastomosis. The oscillatory shear index increased with wider bypass and more acute angle. The maximum of spatial gradient of WSS concentrated around the floor and toe of the anastomosis and decreased with more acute angle and wider bypass, the temporal gradient of WSS was stretched more towards the side wall. Greater bypass to target vessel ratio and more acute anastomosis angle promote hemodynamics known to reduce formation of intimal hyperplasia.

Systemic and Pulmonary Vascular Remodelling in Chronic Obstructive Pulmonary Disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is associated with subclinical systemic atherosclerosis and pulmonary vascular remodelling characterized by intimal hyperplasia and luminal narrowing. We aimed to determine differences in the intimal thickening of systemic and pulmonary arteries in COPD subjects and smokers. Secondary aims include comparisons with a non-smokers group; determining the clinical variables associated with systemic and pulmonary intimal thickening, and the correlations between systemic and pulmonary remodelling changes.

Methods

All consecutive subjects undergoing lung resection were included and divided into 3 groups: 1) COPD, 2) smokers, and 3) non-smokers. Sections of the 5th intercostal artery and muscular pulmonary arteries were measured by histo-morphometry. Four parameters of intimal thickening were evaluated: 1) percentage of intimal area (%IA), 2) percentage of luminal narrowing, 3) intimal thickness index, and 4) intima-to-media ratio.

Results

In the adjusted analysis, the systemic arteries of COPD subjects showed greater intimal thickening (%IA) than those of smokers (15.6±1.5% vs. 14.2±1.6%, p = 0.038). In the pulmonary arteries, significant differences were observed for %IA between the 2 groups (37.3±2.2% vs. 29.3±2.3%, p = 0.016). Among clinical factors, metabolic syndrome, gender and COPD status were associated with the systemic intimal thickening, while only COPD status was associated with pulmonary intimal thickening. A correlation between the %IA of the systemic and pulmonary arteries was observed (Spearman’s rho = 0.46, p = 0.008).

Conclusions

Greater intimal thickening in systemic and pulmonary arteries is observed in COPD patients than in smokers. There is a correlation between systemic and pulmonary vascular remodelling in the overall population.

Loss of Endothelial Barrier in Marfan Mice (mgR/mgR) Results in Severe Inflammation after Adenoviral Gene Therapy

Objectives

Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs). In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1) in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR) in order to reduce elastolysis.

Methods

We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group). Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6) were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1) or β-galactosidase (Ad.β-Gal). As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC) and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI), and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM).

Results

IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43), but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00). Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001). As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001). However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated Marfan aorta: Ad.hTIMP-1 p = 0.902; control Ad.β-Gal. p = 0.165). The virus-untreated and not transplanted mgR/mgR aorta revealed a significant increase of albumin diffusion through the endothelial barrier (p = 0.037). TEM analysis of adenovirus-exposed mgR/mgR aortas displayed disruption of the basement membrane and basolateral space.

Conclusions

Murine Marfan aortic grafts developed severe inflammation after adenoviral contact. We demonstrated that fibrillin-1 deficiency is associated with relevant dysfunction of the endothelial barrier that enables adenovirus to induce vessel-harming inflammation. Endothelial dysfunction may play a pivotal role in the development of the vascular phenotype of Marfan syndrome.

Preoperative dietary restriction reduces intimal hyperplasia and protects from ischemia-reperfusion injury

OBJECTIVE

Whereas chronic overnutrition is a risk factor for surgical complications, long-term dietary restriction (reduced food intake without malnutrition) protects in preclinical models of surgical stress. Building on the emerging concept that acute preoperative dietary perturbations can affect the body's response to surgical stress, we hypothesized that short-term high-fat diet (HFD) feeding before surgery is detrimental, whereas short-term nutrient/energy restriction before surgery can reverse negative outcomes. We tested this hypothesis in two distinct murine models of vascular surgical injury, ischemia-reperfusion (IR) and intimal hyperplasia (IH).

METHODS

Short-term overnutrition was achieved by feeding mice a HFD consisting of 60% calories from fat for 2 weeks. Short-term dietary restriction consisted of either 1 week of restricted access to a protein-free diet (protein/energy restriction) or 3 days of water-only fasting immediately before surgery; after surgery, all mice were given ad libitum access to a complete diet. To assess the impact of preoperative nutrition on surgical outcome, mice were challenged in one of two fundamentally distinct surgical injury models: IR injury to either kidney or liver, or a carotid focal stenosis model of IH.

RESULTS

Three days of fasting or 1 week of preoperative protein/energy restriction attenuated IH development measured 28 days after focal carotid stenosis. One week of preoperative protein/energy restriction also reduced plasma urea, creatinine, and damage to the corticomedullary junction after renal IR and decreased aspartate transaminase, alanine transaminase, and hemorrhagic necrosis after hepatic IR. However, exposure to a HFD for 2 weeks before surgery had no significant impact on kidney or hepatic function after IR or IH after focal carotid stenosis.

CONCLUSIONS

Short-term dietary restriction immediately before surgery significantly attenuated the vascular wall hyperplastic response and improved IR outcome. The findings suggest plasticity in the body's response to these vascular surgical injuries that can be manipulated by novel yet practical preoperative dietary interventions.

Carotid thin fluttering bands: A new element of arterial wall remodelling? An ultrasound study

Carotid artery ultrasound is a non-invasive and reproducible technique used for early atherosclerotic assessment. Intimal flap has been described in the presence of dissection or mobile plaque rupture, however presence of carotid thin fluttering bands (TFBs) have not been described yet. To investigate frequency, characteristics and impact of TFBs in carotid lumen of patients who underwent carotid ultrasound scan (CUS). 3341 patients were admitted from January 2009 to January 2014. Patients with history of cerebral ischemia (CI) were excluded. In the cases in which TFBs were observed, a 3-months clinical and CUS follow-up (FU) was performed. TFBs were found in 71 patients (2.1%). The mean age was 63.41 ± 11.20 years (range 42-89). All patients showed a mean increase in intima-media thickness. We identified two subgroups: in 22 patients the TFB was related to a carotid plaque while in 49 no carotid plaque was found. TFB mostly originated in the carotid bulb (88.7%) and was similarly located in carotid arteries (49.3% left-side and 50.7% right-side). CUS and clinical FU were available for all patients (mean duration 25.34 months, median 19). CI occurred in none of the patients. TFB disappeared in 13 patients (18.3%) with no sign or symptoms of CI. In 3 of 49 patients without carotid plaque (6.1%), progressive thickening beneath TFB was observed. TFB is a rare finding. Longer FU is needed to evaluate its prognosis. To date, the pathophysiology is unknown, however it could be related to vascular remodeling.

Hiperplasia em túnicas de artérias coronárias de beijupirás criados em sistema offshore

As lesões coronarianas já foram relatadas em espécies de peixes anádromos, com características semelhantes às observadas em aterosclerose humana, mas não em peixes cultivados sem interferência de padrões reprodutivos. Objetivou-se descrever lesões coronarianas em beijupirá (Rachycentron canadum) criado em sistema offshore, em 54 exemplares coletados ao longo do cultivo de oito meses. Amostras de tecido cardíaco de alevinos e juvenis foram submetidas à análise histopatológica e à microscopia eletrônica de transmissão (MET), para visualização de lesões coronarianas, sendo as lâminas histológicas coradas pela técnica de hematoxilina-eosina, ácido periódico de Schiff, alcian blue e reticulina de Gomori. Exames realizados pela fotomicroscopia de luz evidenciaram lesões arteriais caracterizadas por hiperplasia das túnicas íntima e média de artérias coronárias em, respectivamente, 29,63% e 79,63% dos animais, com redução do lúmen arterial. Na MET, foram observadas alterações na estrutura das coronárias com espessamento do endotélio e membrana basal, proliferação de fibroblastos e fibras colágenas, com acúmulo de material lipídico subendotelial, resíduos celulares aderidos à membrana basal e vesículas pinocitóticas com presença de lisossomos isolados. Constatou-se que os peixes da espécie Rachycentron canadum criados em cativeiro desenvolvem lesão arterial do tipo crônica degenerativa inflamatória.