Modelling lower-limb peripheral arterial disease using clinically available datasets: impact of inflow boundary conditions on hemodynamic indices for restenosis prediction.

BACKGROUND AND OBJECTIVES: The integration of hemodynamic markers as risk factors in restenosis prediction models for lower-limb peripheral arteries is hindered by fragmented clinical datasets. Computed tomography (CT) scans enable vessel geometry reconstruction and can be obtained at different times than the Doppler ultrasound (DUS) images, which provide information on blood flow velocity. Computational fluid dynamics (CFD) simulations allow the computation of near-wall hemodynamic indices, whose accuracy depends on the prescribed inlet boundary condition (BC), derived from the DUS images. This study aims to: (i) investigate the impact of different DUS-derived velocity waveforms on CFD results; (ii) test whether the same vessel areas, subjected to altered hemodynamics, can be detected independently of the applied inlet BC; (iii) suggest suitable DUS images to obtain reliable CFD results. METHODS: CFD simulations were conducted on three patients treated with bypass surgery, using patient-specific DUS-derived inlet BCs recorded at either the same or different time points than the CT scan. The impact of the chosen inflow condition on bypass hemodynamics was assessed in terms of wall shear stress (WSS)-derived quantities. Patient-specific critical thresholds for the hemodynamic indices were applied to identify critical luminal areas and compare the results with a reference obtained with a DUS image acquired in close temporal proximity to the CT scan. RESULTS: The main findings indicate that: (i) DUS-derived inlet velocity waveforms acquired at different time points than the CT scan led to statistically significantly different CFD results (p<0.001); (ii) the same luminal surface areas, exposed to low time-averaged WSS, could be identified independently of the applied inlet BCs; (iii) similar outcomes were observed for the other hemodynamic indices if the prescribed inlet velocity waveform had the same shape and comparable systolic acceleration time to the one recorded in close temporal proximity to the CT scan. CONCLUSIONS: Despite a lack of standardised data collection for diseased lower-limb peripheral arteries, an accurate estimation of luminal areas subjected to altered near-wall hemodynamics is possible independently of the applied inlet BC. This holds if the applied inlet waveform shares some characteristics - derivable from the DUS report - as one matching the acquisition time of the CT scan.

ASAP─Automated Sonication-Free Acid-Assisted Proteomes─from Cells and FFPE Tissues.

Formalin-fixed, paraffin-embedded (FFPE) tissues are an invaluable resource for retrospective studies, but protein extraction and subsequent sample processing steps have been shown to be challenging for mass spectrometry (MS) analysis. Streamlined high-throughput sample preparation workflows are essential for efficient peptide extraction from complex clinical specimens such as fresh frozen tissues or FFPE. Overall, proteome analysis has gained significant improvements in the instrumentation, acquisition methods, sample preparation workflows, and analysis pipelines, yet even the most recent FFPE workflows remain complex and are not readily scalable. Here, we present an optimized workflow for automated sonication-free acid-assisted proteome (ASAP) extraction from FFPE sections. ASAP enables efficient protein extraction from FFPE specimens, achieving similar proteome coverage as established methods using expensive sonicators, resulting in reduced sample processing time. The broad applicability of ASAP on archived pediatric tumor FFPE specimens resulted in high-quality data with increased proteome coverage and quantitative reproducibility. Our study demonstrates the practicality and superiority of the ASAP workflow as a streamlined, time- and cost-effective pipeline for high-throughput FFPE proteomics of clinical specimens.

Efficacy and safety of foam sclerotherapy with sodium tetradecyl sulfate as preferred sclerosant of venous malformations based on experience from a single specialist center.

OBJECTIVE: We have assessed the efficacy and safety of interventional therapy for venous malformations (VMs), with foam sclerotherapy as the treatment of choice according to our experience at a single specialist center. METHODS: All the patients with VMs who had undergone interventional therapy (ie, embolo-sclerotherapy and/or open surgery) from January 1, 2015 to December 31, 2019 were identified through a prospective database. The VM types were classified according to the Puig classification. The outcome measures assessed included the efficacy and complications. The former was divided into four groups: no response, mild response, moderate response, and complete response. The complications were defined as any tissue or functional damage, distal embolization, or tissue reaction. The continuous variables were compared using the analysis of variance F test, and discrete variables were analyzed using the χ2 tests. P values < .05 were considered statistically significant. RESULTS: A total of 207 patients were included. Puig type I lesions were significantly less likely to have received foam sclerotherapy using sodium tetradecyl sulfate (STS) 3% (P ≤ .001) and more likely to have been surgically excised (P ≤ .001). At the patient's first procedure during the study period, the volumes of foam STS 3% were significantly different across all types of VM (P ≤ .001). The patients with type I VMs had received a lower volume of STS 3% compared with those with type II and III VMs. The efficacy outcome categories were significantly different across all types of VMs (P ≤ .001). Overall, only 14 patients (6.8%) had reported no improvement in efficacy, and 38 patients (18%) had not attended follow-up. Therefore, 154 patients (74.8%) had experienced some form of efficacious outcome. Ten patients (4.8%) had developed complications such as hematoma, thrombophlebitis, and ulceration. The incidence of complications differed significantly across the categories (P = .030), with more complications reported for those with type I VMs. CONCLUSIONS: We found that intervention with foam sclerotherapy using STS 3% is clinically effective and safe for patients with VMs and was most successful for those with Puig type I and II VMs.

Multi-omic profiling of the leukemic microenvironment shows bone marrow interstitial fluid is distinct from peripheral blood plasma.

BACKGROUND: The bone marrow is the place of hematopoiesis with a microenvironment that supports lifelong maintenance of stem cells and high proliferation. It is not surprising that this environment is also favourable for malignant cells emerging in the bone marrow or metastasizing to it. While the cellular composition of the bone marrow microenvironment has been extensively studied, the extracellular matrix and interstitial fluid components have received little attention. Since the sinusoids connect the bone marrow interstitial fluid to the circulation, it is often considered to have the same composition as peripheral blood plasma. Stark differences in the cellular composition of the bone marrow and peripheral blood with different secretory capacities would however suggest profound differences. METHODS: In this study we set out to better define if and how the bone marrow interstitial fluid (BMIF) compares to the peripheral blood plasma (PBP) and how both are remodeled during chemotherapy. We applied a multi-omic strategy to quantify the metabolite, lipid and protein components as well as the proteolytic modification of proteins to gain a comprehensive understanding of the two compartments. RESULTS: We found that the bone marrow interstitial fluid is clearly distinct from peripheral blood plasma, both during active pediatric acute lymphoblastic leukemia and following induction chemotherapy. Either compartment was shaped differently by active leukemia, with the bone marrow interstitial fluid being rich in extracellular vesicle components and showing protease dysregulation while the peripheral blood plasma showed elevation of immune regulatory proteins. Following chemotherapy, the BMIF showed signs of cellular remodeling and impaired innate immune activation while the peripheral blood plasma was characterized by restored lipid homeostasis. CONCLUSION: This study provides a comprehensive examination of the fluid portion of the acute lymphoblastic leukemia microenvironment and finds the contribution of either microenvironment to tumourigenesis.

The Impact of Same Gender Speed-Mentoring on Women's Perceptions of a Career in Surgery - A Prospective Cohort Study.

BACKGROUND: Mentoring is critically important for the personal and professional development of a surgeon. Early career stage mentoring by same-gender role models may help ameliorate the gender imbalance in surgery based on our understanding of barriers for women pursuing surgical careers. A novel method of establishing these relationships is speed mentoring. This study aims to examine the impact of a one-day speed-mentoring session with same gender mentors on a cohort's perceptions of a career in surgery. DESIGN: This prospective pre-post study compared attitudes and perceptions of a career in surgery before and after a speed-mentoring session with female surgeons. Mentees were assigned into groups of 1 or 2 and were paired with a female surgeon for 8 minutes. Each mentee group then rotated to another mentor for the same amount of time and this process continued for a total of twelve sessions. Mentees completed a 19-point questionnaire before and after the speed mentoring intervention. SETTING: This multicenter study included participants from across the United Kingdom. PARTICIPANTS: Inclusion criteria were female gender and medical student or foundation year doctor (internship year 1 or 2) status. Three hundred and forty participants participated in the intervention, 191 were included in the analysis. RESULTS: Following intervention, the percentage of participants who agreed that having a family would negatively impact a woman's surgical career progression significantly decreased from 46.6% to 23.0%. The percentage of participants who agreed that an "old boys' club" attitude exists in surgery also significantly decreased (73.8%-58.1%). The percentage of participants who agreed it was more difficult for a woman to succeed in her surgical career than a man significantly decreased (73.8%-64.9%). One hundred and eighty-three (96%) participants agreed that mentorship is important for career progression and 153 (71.2%) participants stated that they did not have someone who they considered a mentor. CONCLUSIONS: Conducting a speed mentoring program with same-gender role models significantly changed female medical students' and junior doctors' perceptions of women in surgery. The results suggest that such programs may be effective tools for facilitating mentor-mentee relationships and could be employed by surgical organizations to encourage a diverse uptake into surgery.

A patient-specific multi-modality abdominal aortic aneurysm imaging phantom.

PURPOSE: Multimodality imaging of the vascular system is a rapidly growing area of innovation and research, which is increasing with awareness of the dangers of ionizing radiation. Phantom models that are applicable across multiple imaging modalities facilitate testing and comparisons in pre-clinical studies of new devices. Additionally, phantom models are of benefit to surgical trainees for gaining experience with new techniques. We propose a temperature-stable, high-fidelity method for creating complex abdominal aortic aneurysm phantoms that are compatible with both radiation-based, and ultrasound-based imaging modalities, using low cost materials. METHODS: Volumetric CT data of an abdominal aortic aneurysm were acquired. Regions of interest were segmented to form a model compatible with 3D printing. The novel phantom fabrication method comprised a hybrid approach of using 3D printing of water-soluble materials to create wall-less, patient-derived vascular structures embedded within tailored tissue-mimicking materials to create realistic surrounding tissues. A non-soluble 3-D printed spine was included to provide a radiological landmark. RESULTS: The phantom was found to provide realistic appearances with intravascular ultrasound, computed tomography and transcutaneous ultrasound. Furthermore, the utility of this phantom as a training model was demonstrated during a simulated endovascular aneurysm repair procedure with image fusion. CONCLUSION: With the hybrid fabrication method demonstrated here, complex multimodality imaging patient-derived vascular phantoms can be successfully fabricated. These have potential roles in the benchtop development of emerging imaging technologies, refinement of novel minimally invasive surgical techniques and as clinical training tools.

Quality of life and mental health of patients with vascular malformations in a single specialist center in the United Kingdom.

OBJECTIVE: Patients with vascular malformations suffer from chronic debilitating symptoms that have been shown to contribute negatively to their quality of life (QoL) and mental health. Despite this, the current literature evaluating the QoL and mental health of patients with vascular malformations remains scarce. Our aim was to evaluate the QoL and mental health of patients with vascular malformations. METHODS: We prospectively analyzed the validated health-related QoL (HRQoL) questionnaires: the RAND Health Care 36-Item Short Form Survey (SF-36), Hospital Anxiety and Depression Scale (HADS), and visual analogue score for pain reported by 253 patients with vascular malformations in a specialist center of vascular anomalies in the UK over 2 years. RESULTS: Patients with vascular malformations reported significantly poorer SF-36 scores in all domains compared with the UK general population. Patients with low-flow vascular malformations and arteriovenous malformations reported little variations in SF-36, HADS, and visual analogue score for pain scores. No significant association was found between age and any of the health-related QoL scores, other than the physical functioning in SF-36. Female patients reported significantly lower physical and social functioning of SF-36 and worse HADS-Depression than their male counterparts. Patients with syndromic vascular malformations reported significantly lower SF-36 scores in role-physical, role-emotional and bodily pain than nonsyndromic vascular malformations. CONCLUSIONS: This study concluded that patients with vascular malformations reported worse QoL than the UK general population. Therefore, the assessment and management of QoL and mental health should be incorporated into the overall treatment strategies of patients with vascular malformations.

Computer assisted Doppler waveform analysis and ultrasound derived turbulence intensity ratios can predict early hyperplasia development in newly created vascular access fistula: Pilot study, methodology and analysis.

OBJECTIVES: Following surgical creation of arterio-venous fistulae (AVF), the desired outward remodeling is often accompanied by the development of neointimal hyperplasia (NIH), which can stymie maturation and may lead to thrombosis and access failure. The aim of this study was to investigate the feasibility of using a non-invasive test, to detect and quantify the turbulent flow patterns believed to be associated with NIH development. DESIGN: This was a prospective, observational study. Ultrasound derived turbulence intensity ratios (USTIR) were calculated from spectral Doppler waveforms, recorded from newly formed AVF, and were compared with haemodynamic and structural changes observed during the initial maturation period. SETTING: Measurements were obtained by accredited Clinical Vascular Scientists, at the Royal Free Hospital, London. PARTICIPANTS: Patients with newly created AVF were invited to participate in the study. A total of 30 patients were initially recruited with 19 participants completing the 10 week study protocol. OUTCOME MEASURES: The primary outcome measure was the development of NIH resulting in a haemodynamically significant lesion.The secondary outcome was successful maturation of the AVF at 10 weeks. RESULTS: Elevated USTIR in the efferent vein 2 weeks post surgery corresponded to the development of NIH formation (P = 0.02). A cut off of 6.39% predicted NIH development with a sensitivity of 87.5% and a specificity of 80%. CONCLUSION: Analysis of Doppler waveforms can successfully identify deleterious flow patterns and predict inward luminal remodelling in maturing AVF. We propose a longitudinal follow up study to assess the viability of this technique as a surveillance tool.

Single Center Experience of Sirolimus Therapy in Head and Neck Low-flow Vascular Malformations.

OBJECTIVE: Recently, studies have shown that sirolimus is clinically efficacious in the treatment of some low-flow vascular malformations (LFVM). This study aimed to assess the efficacy and safety of sirolimus in treating complex head and neck (H&N) LFVM that were challenging and/or refractory to standard treatment. METHODS: Each patient had baseline and 6-months assessments consisting of clinical history and examination, quality of life (QoL) questionnaires, laboratory investigations, MRI and medical photography. Patients were followed up 1-week and then 1-monthly for 6-months. Wilcoxon signed-rank test was used to compare pre-and 6-months treatment in all 8 domains of RAND 36-Item Short Form Health Survey (SF-36), hospital anxiety and depression scale (HADS), and visual analog score for pain (VAS-P). P < 0.05 was considered significant. RESULTS: Seven patients (median age 43 years, range 23-65 years) were recruited. Six patients completed the six-months course of therapy with 1 patient withdrawing due to intolerable side effects. All six patients reported reduction of swelling with and without other symptom improvement related to the vascular malformations while on treatment. However, at 1-month review after discontinuation of sirolimus, 5 patients reported return of initial symptoms. Overall, patients demonstrated an improvement in QoL six-months treatment but there was no statistical significance (P > 0.05) in all 8 domains of SF-36, HADS and VAS-P. Five patients demonstrated a minimum 10% decrease in lesion size six-months treatment (median 21%, range 13-40%). A Wilcoxon signed-rank test showed that sirolimus treatment did elicit a statistically significant change in lesion size in either direction (Z = -1.992, P = 0.046). The most common side effects found were dyslipidaemia (n-4) and mouth ulcers (n = 2). CONCLUSION: In our preliminary experience, sirolimus is effective and safe in treating patients with complex H&N LFVM. This provides an alternative treatment where standard treatment is challenging and/or refractory.

PDX models reflect the proteome landscape of pediatric acute lymphoblastic leukemia but divert in select pathways.

BACKGROUND: Murine xenografts of pediatric leukemia accurately recapitulate genomic aberrations. How this translates to the functional capacity of cells remains unclear. Here, we studied global protein abundance, phosphorylation, and protein maturation by proteolytic processing in 11 pediatric B- and T- cell ALL patients and 19 corresponding xenografts. METHODS: Xenograft models were generated for each pediatric patient leukemia. Mass spectrometry-based methods were used to investigate global protein abundance, protein phosphorylation, and limited proteolysis in paired patient and xenografted pediatric acute B- and T- cell lymphocytic leukemia, as well as in pediatric leukemia cell lines. Targeted next-generation sequencing was utilized to examine genetic abnormalities in patients and in corresponding xenografts. Bioinformatic and statistical analysis were performed to identify functional mechanisms associated with proteins and protein post-translational modifications. RESULTS: Overall, we found xenograft proteomes to be most equivalent with their patient of origin. Protein level differences that stratified disease subtypes at diagnostic and relapse stages were largely recapitulated in xenografts. As expected, PDXs lacked multiple human leukocyte antigens and complement proteins. We found increased expression of cell cycle proteins indicating a high proliferative capacity of xenografted cells. Structural genomic changes and mutations were reflected at the protein level in patients. In contrast, the post-translational modification landscape was shaped by leukemia type and host and only to a limited degree by the patient of origin. Of 201 known pediatric oncogenic drivers and drug-targetable proteins, the KMT2 protein family showed consistently high variability between patient and corresponding xenografts. Comprehensive N terminomics revealed deregulated proteolytic processing in leukemic cells, in particular from caspase-driven cleavages found in patient cells. CONCLUSION: Genomic and host factors shape protein and post-translational modification landscapes differently. This study highlights select areas of diverging biology while confirming murine patient-derived xenografts as a generally accurate model system.

Patient radiation exposure from embolo-sclerotherapy of peripheral vascular malformations.

OBJECTIVE: Embolo-sclerotherapy (EST) is the mainstay therapy for peripheral vascular malformations that involves the exposure of patients to ionizing radiation. We analyzed the radiation exposure to patients from EST of peripheral vascular malformations during a 5-year period in a single specialist center. METHODS: All patients who had undergone EST at a single specialist center for peripheral vascular malformations from January 1, 2013 to January 8, 2018 were identified from a prospectively collected database. Data collection included basic demographics, procedure date, anatomic site, type of vascular malformations, and procedural details. Radiation exposure, measured as the dose-area product (DAP) and fluoroscopy time, of all patients who had undergone EST during the study period were retrospectively reviewed. Statistical analysis was performed using the Mann-Whitney U and Kruskal-Wallis tests for comparison between subgroups. P < .05 was considered statistically significant. RESULTS: A total of 237 patients (median age, 30 years; range, 1-73 years) had undergone 419 EST sessions during the study period. Of the 237 patients, 61 (25.7%) had had arteriovenous malformations (AVMs) and had undergone 140 EST sessions (33.4%) and 176 (74.3%) had had venous and lymphatic malformations and had undergone 279 EST sessions (66.6%). Patients with AVMs had undergone a median of 2 procedures (range, 1-13) compared with a median of 1 (range, 1-6) for venous and lymphatic malformations within the study period. The median DAP for the single and cumulative EST for peripheral vascular malformations was 1.26 Gycm2 (range, 0.00-698.36 Gycm2) and 1.91 Gycm2 (range, 0.00-1300.24 Gycm2), respectively. The median fluoroscopy time for single and cumulative EST was 19 seconds (range, 1-3846 seconds) and 30 seconds (range, 1-5843 seconds), respectively. Significantly greater patient radiation exposure, in DAP and fluoroscopy time, was measured for single and cumulative EST for AVMs compared with venous and lymphatic malformations (P < .01 for both; Mann-Whitney U test). A significant difference in DAP but not fluoroscopy time was found when the anatomic areas of vascular malformations were compared. CONCLUSIONS: Patient radiation exposure for EST for peripheral vascular malformations, measured in DAP and fluoroscopy time, appeared to be generally less than that reported for endovascular arterial and deep venous interventions. However, some patients with peripheral vascular malformations received relatively high radiation doses. Further studies to investigate the risk factors and long-term side effects of radiation exposure in these patients and strategies to reduce these are required.

Emerging importance of molecular pathogenesis of vascular malformations in clinical practice and classifications.

Vascular malformations occur during early vascular development resulting in abnormally formed vessels that can manifest as arterial, venous, capillary or lymphatic lesions, or in combination, and include local tissue overdevelopment. Vascular malformations are largely caused by sporadic somatic gene mutations. This article aims to review and discuss current molecular signaling pathways and therapeutic targets for vascular malformations and to classify vascular malformations according to the molecular pathways involved. A literature review was performed using Embase and Medline. Different MeSH terms were combined for the search strategy, with the aim of encompassing all studies describing the classification, pathogenesis, and treatment of vascular malformations. Major pathways involved in the pathogenesis of vascular malformations are vascular endothelial growth factor (VEGF), Ras/Raf/MEK/ERK, angiopoietin-TIE2, transforming growth factor beta (TGF-ß), and PI3K/AKT/mTOR. These pathways are involved in controlling cellular growth, apoptosis, differentiation, and proliferation, and play a central role in endothelial cell signaling and angiogenesis. Many vascular malformations share similar aberrant molecular signaling pathways with cancers and inflammatory disorders. Therefore, selective anticancer agents and immunosuppressants may be beneficial in treating vascular malformations of specific mutations. The current classification systems of vascular malformations, including the International Society of the Study of Vascular Anomalies (ISSVA) classification, are primarily observational and clinical, and are not based on the molecular pathways involved in the pathogenesis of the condition. Several molecular pathways with potential therapeutic targets have been demonstrated to contribute to the development of various vascular anomalies. Classifying vascular malformations based on their molecular pathogenesis may improve treatment by determining the underlying nature of the condition and their potential therapeutic target.

Hyperglycaemia and Ischaemia Impair Wound Healing via Toll-like Receptor 4 Pathway Activation in vitro and in an Experimental Murine Model.

OBJECTIVE: Diabetes mellitus has reached epidemic proportions. Foot ulceration is a multifactorial complication of diabetes associated with marked morbidity and mortality. Innate immune Toll-like receptor 4 (TLR4) mediated inflammation has been implicated in the systemic pathogenesis of diabetes and may contribute to impairment of wound healing. This study investigates the effect of high glucose and hypoxic conditions on TLR4 activation and signalling in vitro and in vivo. METHODS: Fibroblasts cultured at physiological glucose concentration (5.5 mM) were exposed to glucose concentrations from 0 mM to 25 mM, with duplicates placed in a hypoxic chamber. TLR4 inhibition was assessed in the 25 mM glucose groups. Diabetes was induced in wild type (WT) and TLR4 knockout (KO) C57BL/6 mice by intraperitoneal injection of low dose streptozocin (STZ). Hindlimb ischaemia was induced by femoral artery ligation four weeks post streptozocin, and a full thickness 4 mm skin wound inflicted below the knee. Wound healing was assessed via digital planimetry on days 3, 7, and 14 post surgery. RESULTS: Hypoxic and high glucose (25 mM) conditions led to an increase in TLR4 protein expression, apoptosis, and interleukin (IL)-6 release. Inhibition with a TLR4 neutralising antibody and specific TLR4 antagonist ameliorated the effects of high glucose and ischaemia (p < .05). In vivo, wound healing was significantly impaired in the diabetic ischaemic group at day 14 (p < .05). Diabetic ischaemic wounds in TLR4 KO mice exhibited significantly improved healing rates compared with those in WT mice at all time points. CONCLUSION: Hypoxia stimulates upregulation of TLR4 protein expression and this effect is exaggerated by hyperglycaemia. In TLR4 KO mice, there is a significant improvement in the healing of diabetic ischaemic wounds compared with WT. It is suggested that a synergistic effect between hypoxia and hyperglycaemia impairing wound healing exists, through TLR4 mediated inflammation.

Sensitive Determination of Proteolytic Proteoforms in Limited Microscale Proteome Samples.

Protein N termini unambiguously identify truncated, alternatively translated or modified proteoforms with distinct functions and reveal perturbations in disease. Selective enrichment of N-terminal peptides is necessary to achieve proteome-wide coverage for unbiased identification of site-specific regulatory proteolytic processing and protease substrates. However, many proteolytic processes are strictly confined in time and space and therefore can only be analyzed in minute samples that provide insufficient starting material for current enrichment protocols. Here we present High-efficiency Undecanal-based N Termini EnRichment (HUNTER), a robust, sensitive and scalable method for the analysis of previously inaccessible microscale samples. HUNTER achieved identification of >1000 N termini from as little as 2 µg raw HeLa cell lysate. Broad applicability is demonstrated by the first N-terminome analysis of sorted human primary immune cells and enriched mitochondrial fractions from pediatric cancer patients, as well as protease substrate identification from individual Arabidopsis thaliana wild type and Vacuolar Processing Enzyme-deficient mutant seedlings. We further implemented the workflow on a liquid handling system and demonstrate the feasibility of clinical degradomics by automated processing of liquid biopsies from pediatric cancer patients.

Successful Repair of a Vasculopathic Aneurysmal Brachial Artery in a Patient with Type 1 Neurofibromatosis.

Vasculopathy is a well-recognized abnormality associated with neurofibromatosis type 1(NF1) and may cause stenoses, aneurysms, and arteriovenous malformations. We report a challenging case of a woman with NF1, who presented with spontaneous rupture of a brachial aneurysm around her right elbow, on a background of previous debulking and soft tissue reconstructive surgery in the same arm. She underwent successful delayed reconstruction of the brachial artery using an autologous great saphenous vein graft.

Toll-like receptors 2 and 6 mediate apoptosis and inflammation in ischemic skeletal myotubes.

Critical limb ischemia (CLI) is associated with skeletal muscle damage. However, the pathophysiology of the muscle damage is poorly understood. Toll-like receptors (TLR) have been attributed to play a role in ischemia-induced tissue damage but their role in skeletal muscle damage in CLI is unknown. TLR2 and TLR6 expression was found to be upregulated in skeletal muscle of patients with CLI. In vitro, ischemia led to upregulation of TLR2 and TLR6 by myotubes, and activation of the downstream TLR signaling pathway. Ischemia-induced activation of the TLR signaling pathway led to secretion of the pro-inflammatory cytokine interleukin-6 and muscle apoptosis, which were abrogated by neutralising TLR2 and TLR6 antibodies. Our study demonstrates that TLR2 and TLR6 are upregulated in ischemic muscle and play a role in ischemia-induced muscle damage. Thus, manipulating the TLR pathway locally may be of potential therapeutic benefit.

Current Treatment Strategies for Intracranial Aneurysms: An Overview.

Intracranial aneurysm is a leading cause of stroke. Its treatment has evolved over the past 2 decades. This review summarizes the treatment strategies for intracranial aneurysms from 3 different perspectives: open surgery approach, transluminal treatment approach, and new technologies being used or trialed. We introduce most of the available treatment techniques in detail, including contralateral clipping, wrapping and clipping, double catheters assisting coiling and waffle-cone technique, and so on. Data from major trials such as Analysis of Treatment by Endovascular approach of Non-ruptured Aneurysms (ATENA), Internal Subarachnoid Trial (ISAT), Clinical and Anatomical Results in the Treatment of Ruptured Intracranial Aneurysms (CLARITY), and Barrow Ruptured Aneurysm Trial (BRAT) as well as information from other clinical reports and local experience are reviewed to suggest a clinical pathway for treating different types of intracranial aneurysms. It will be a valuable supplement to the current existing guidelines. We hope it could help assisting real-time decision-making in clinical practices and also encourage advancements in managing the disease.

Future research directions to improve fistula maturation and reduce access failure.

With the increasing prevalence of end-stage renal disease, there is a growing need for hemodialysis. Arteriovenous fistulae (AVF) are the preferred type of vascular access for hemodialysis, but maturation and failure continue to present significant barriers to successful fistula use. AVF maturation integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes in the setting of uremia, systemic inflammation, oxidative stress, and pre-existent vascular pathology. AVF can fail due to both failure to mature adequately to support hemodialysis and development of neointimal hyperplasia that narrows the AVF lumen, typically near the fistula anastomosis. Failure due to neointimal hyperplasia involves vascular cell activation and migration and extracellular matrix remodeling with complex interactions of growth factors, adhesion molecules, inflammatory mediators, and chemokines, all of which result in maladaptive remodeling. Different strategies have been proposed to prevent and treat AVF failure based on current understanding of the modes and pathology of access failure; these approaches range from appropriate patient selection and use of alternative surgical strategies for fistula creation, to the use of novel interventional techniques or drugs to treat failing fistulae. Effective treatments to prevent or treat AVF failure require a multidisciplinary approach involving nephrologists, vascular surgeons, and interventional radiologists, careful patient selection, and the use of tailored systemic or localized interventions to improve patient-specific outcomes. This review provides contemporary information on the underlying mechanisms of AVF maturation and failure and discusses the broad spectrum of options that can be tailored for specific therapy.

Potential role of erythropoietin receptors and ligands in attenuating apoptosis and inflammation in critical limb ischemia.

OBJECTIVE: Managing critical limb ischemia (CLI) is challenging. Furthermore, ischemic myopathy prevents good functional outcome after revascularization. Hence, we have focused on limiting the tissue damage rather than angiogenesis, which has traditionally been the motivation to develop nonsurgical treatments for CLI. Erythropoietin (EPO) protects ischemic tissue, and this property may also benefit CLI. The objective of this study was to examine the expression of the tissue-protective EPO receptor complex (EPOR-CD131 [ß-chain of interleukin (IL)-3/IL-5/granulocyte macrophage colony-stimulating factor receptor]) in skeletal muscle obtained from humans with CLI. Because native EPO is thrombogenic, the antiapoptotic and anti-inflammatory effects of a nonhematopoietic helix-B peptide of EPO (ARA 290) were investigated on ischemic myotubes in vitro. METHODS: Tissue was obtained from gastrocnemius muscle of 12 patients undergoing amputation for CLI and from 12 patients without limb ischemia. The expression of EPOR and CD131 was demonstrated by immunohistochemistry and Western blot. A validated in vitro model of myotube ischemia was used in which mature C2C12 myotubes were cultured 6 to 12 hours in a depleted media and gas mixture (20% CO2 and 80% N2). The myotubes were pretreated with EPO or ARA 290 before exposure to simulated ischemia. Apoptosis and cell death were determined by cleaved caspase-3 assay and lactate dehydrogenase release assay. Enzyme-linked immunosorbent assay measured the inflammatory cytokines. RESULTS: EPOR and CD131 were expressed and significantly upregulated in CLI (average optical density [OD] in Western blot [control vs CLI] EPOR, 0.05 U vs 0.1 U; CD131, 0.10 U vs 0.22 U; P < .01). There was colocalization of EPOR and CD131 in the sarcolemma (cell membrane) of the skeletal myofiber. There was no difference in the distribution of colocalization between the CLI and the normal muscle. The ischemic myotubes treated by ARA 290 in vitro had a significantly decreased number of apoptotic cells (ischemia vs ischemia plus ARA 290: 71.1% vs 55.1%; P < .01), cleaved caspase-3 (OD of ischemia vs ischemia plus ARA 290: 0.15 U vs 0.02 U; P < .01), lactate dehydrogenase release (ischemia vs ischemia plus ARA 290: 32.5 U/L vs 21.3 U/L; P < .01), and IL-6 release (OD at 450 nm, ischemia vs ischemia plus ARA 290: 0.18 vs 0.13; P < .01). CONCLUSIONS: This study demonstrates the expression and the upregulation of EPOR and CD131 in CLI and also shows that EPOR and CDI are colocalized in the cell membrane of both ischemic and control muscle fiber. The in vitro experiments demonstrate that ARA 290 decreases inflammation and apoptosis of ischemic myotubes. ARA 290 may potentially be used as adjunctive treatment for CLI.