bluuebunny/crossref_metadata_2025 huggingface dataset:
Biogenic structures in soils under a primary Atlantic Rain Forest in SE-Brazil
Authors: Diogo Filho Geraldo José , Queiroz Neto José Pereira de
Published: July 2021

As minhocas desempenham papeis importantes na formação do solo, contudo pouca atenção é dada à bioturbação pelos pedólogos. A descrição morfológica tradicional, assim como os procedimentos de caracterização física e química do solo, não contemplam as estruturas biogênicas, que nem mesmo são consideradas pelo Sistema Brasileiro de Classificação de Solos. O objetivo deste trabalho foi caracterizar as feições biogênicas como canais, câmaras e dejeções, produzidas pela atividade de minhocas no solo da Estação Biológica de Boracéia, em São Paulo. As bioestruturas foram coletadas, medidas, fotografadas e organizadas por tipo (cilíndricos e blocos irregulares) e tamanho (muito pequeno, pequeno, médio, grande e muito grande). Foram realizadas análises físicas e químicas destes materiais e do solo: granulometria, carbono orgânico, bases trocáveis (Ca2+, Mg2+, K+, P). Alguns canais biogênicos encontravam-se preenchidos por solo revolvido (as crotovinas) e outros não. As características redoximórficas são muito comuns nas paredes dos canais, porque esses dutos biogênicos contribuem para a difusão de O2 do solo e a remoção de CO2 no perfil. As dejeções têm textura arenosa, o conteúdo de carbono orgânico nelas é três vezes superior comparado ao da matriz do solo, indicando a eficiência de certos grupos ecológicos de anelídeos na incorporação de matéria orgânica em subsuperfície. Os coprólitos também apresentaram maiores quantidades de fósforo, cálcio e magnésio do que o solo. As minhocas cumprem funções fundamentais no solo, como aeração, agregação, incorporação de matéria orgânica e aumento de sua fertilidade. Portanto, os agregados biogênicos influenciam fortemente na pedogênese, especialmente na zona tropical.
Quantificação da geodiversidade e suas implicações para a geoconservação da Estrada Real – porção centro-norte do Caminho dos Diamantes
Authors: Pizani Fernanda Mara Coelho , Ruchkys Ursula
Published: July 2021

O Caminho dos Diamantes está localizado no Estado de Minas Gerais e pertence à Estrada Real, importante rota turística do país. Especificamente a porção centro-norte do Caminho dos Diamantes, com área de 20.977,23 km2, possui relevantes valores culturais e naturais com grande potencial para uso turístico. Neste trabalho apresenta-se um mapeamento quantitativo da geodiversidade desta porção da Estrada Real por meio da análise de dados espaciais digitais processados em sistemas de informação geográfica. Para o cálculo do índice de geodiversidade utilizou-se as seguintes variáveis: geologia, relevo, solo, cavidades naturais e hidrografia. O resultado final é um mapa síntese com os índices classificados em cinco categorias: muito baixo (0,8%), baixo (35,8%), médio (31,6%), alto (30,9%) e muito alto (0,9%). Cerca de 1/3 da área de estudo é composta por áreas de alta e muito alta geodiversidade. Apesar das áreas de muito alta geodiversidade se apresentarem com baixo valor relativo, estas estão situadas, sobretudo, no entorno da rota principal da Estrada Real e apenas uma mínima parte desta está amparada e protegida por uma Unidade de Conservação – Área de Proteção Ambiental Morro da Pedreira. Os resultados podem auxiliar o poder público na identificação de áreas (alta e muito alta geodiversidade) que devem ser prioritárias para ações de conservação e aproveitamento turístico.
Predição de absenteísmo docente na rede pública com machine learning
Authors: Fernandes Fernando Timoteo , Chiavegatto Filho Alexandre Dias Porto
Published: July 2021

OBJETIVO Predizer o risco de ausência laboral decorrente de morbidades dos docentes que atuam na educação infantil na rede pública municipal, com o uso de algoritmos de machine learning. MÉTODOS Trata-se de um estudo transversal utilizando dados secundários, públicos e anônimos da Relação Anual de Informações Sociais, selecionando professores da educação infantil que atuaram na rede pública municipal do estado de São Paulo entre 2014 e 2018 (n = 174.294). Foram também vinculados dados da média de alunos por turma e número de habitantes no município. Os dados foram separados em treinamento e teste, utilizando os registros de 2014 a 2016 (n = 103.357) para treinar cinco modelos preditivos e os dados de 2017 a 2018 (n = 70.937) para testar seus desempenhos em dados novos. A performance preditiva dos algoritmos foi avaliada por meio do valor da área abaixo da curva ROC (AUROC). RESULTADOS Todos os cinco algoritmos testados apresentaram área abaixo da curva acima de 0,76. O algoritmo com melhor performance preditiva (redes neurais artificiais) obteve 0,79 de área abaixo da curva, com acurácia de 71,52%, sensibilidade de 72,86%, especificidade de 70,52% e kappa de 0,427 nos dados de teste. CONCLUSÃO É possível predizer casos de afastamentos por morbidade em docentes da rede pública com machine learning usando dados públicos. O melhor algoritmo apresentou melhor resultado da área abaixo da curva quando comparado ao modelo de referência (regressão logística). Os algoritmos podem contribuir para predições mais assertivas na área da saúde pública e da saúde do trabalhador, permitindo acompanhar e ajudar a prevenir afastamentos por morbidade desses trabalhadores.
Abstract 123: Ischemia Mediates Myogenic Progenitor Cell Dysfunction
Authors: Fincher Matthew , Abraham David , Baker Daryll , Tsui Janice
Published: July 2021

Introduction
Treatment options for critical limb ischaemia (CLI) are limited. Recent evidence has suggested that even with successful revascularisation, patients often show little functional improvement. This has been attributed to a musculopathy that occurs in CLI. Myogenic progenitor satellite cells (SCs) provide skeletal muscle with an intrinsic ability to regenerate. It has been shown that there is an increase in SCs in ischaemic muscle, however their function in ischaemia is poorly understood and we hypothesize that ischaemia has a detrimental effect on SC function.

Methods
Gastrocnemius muscle biopsies were taken from CLI patients and compared with non ischaemic control biopsies. The phenotypical changes and frequency of satellite cells were investigated using PAX 7 immunohistochemistry and western blot. C2C12 myoblasts were used in vitro, to investigate the effect of ischaemia on muscle progenitor cell function. Myoblasts were exposed to simulated ischaemia for 24, 48 and 72hrs. Proliferation rates were assessed using an MTT assay. Differentiation and apoptosis were assessed by MYOD and cleaved caspase 3 western blotting respectively.

Results
There is an increased expression of PAX 7 in CLI muscle biopsies, shown by both immunostaining and western blot analysis, suggesting an increased number of SCs in ischaemic human skeletal muscle (p<0.05). Myoblasts cultured in ischaemic conditions demonstrated decreased cell proliferation, reduced myogenic differentiation (decreased MYOD expression), and increased apoptosis (increased cleaved caspase 3 expression).

Conclusion
Despite an upregulation of SCs in ischaemic tissue, their function is suppressed in ischaemic conditions and this may be contributing to the poor functional recovery of patients post revascularisation. Enhancement of muscle regeneration in ischaemia may be a useful therapeutic adjunct in the treatment of CLI.
Abstract 149: Regulation of Pathogen-Associated Molecular Pattern Recognition by the Apo A-I Mimetic Peptide 4F
Authors: Datta Geeta , Crossman David K , Smythies Lesley E , Palgunachari M N , Chaddha Manjula , Anantharamaiah G M , White C R
Published: July 2021

The apolipoprotein A-I (apoA-I) mimetic peptide 4F displays prominent anti-inflammatory properties, including the ability to reduce vascular macrophage content. Macrophages are a heterogenous group of cells that are represented by two principal phenotypes, the classically-activated M1 macrophage and an alternatively-activated M2 phenotype. We previously reported that apoA-I and 4F favor the differentiation of human monocytes to an anti-inflammatory phenotype similar to that displayed by M2 macrophages. Further, 4F treatment attenuated LPS-induced inflammatory responses in monocyte-derived macrophages (MDMs). In the current study, we investigated effects of 4F and vehicle on LPS-induced gene expression in human MDMs by microarray analysis. RNA isolation, labeling and hybridization were performed, and the transcriptional profile was examined using the Human Gene ST 1.0 Affymetrix chip. Analysis of MDM gene expression profiles revealed that 4F modulated mRNA expression for 1099 genes (± 2-fold change, p<0.05), of which 149 genes regulated inflammatory responses. LPS treatment of MDMs significantly up-regulated genes encoding Toll-like receptors (TLR1, 2, 4, 6, and 8) compared to vehicle treatment. These responses were attenuated by 4F treatment. MyD88, CD14, IRAK4, TRAF6, TRAF3, MALT1 and IKBKB, genes that modulate NF-κB activation and subsequent cytokine synthesis, were also reduced by 4F. Corroborating this, FACS analyses showed that pre-treatment of MDMs with 4F reduced the LPS-dependent phosphorylation of NF-κB by 70% compared to vehicle treatment. These 4F-induced responses were also associated with a reduction in TNF-α and IL-6 secretion. These data suggest that an important anti-inflammatory mechanism of 4F action may be to down-regulate genes involved in the TLR signaling pathway, thus attenuating the responsiveness of macrophages to LPS and other pathogen-associated molecular patterns (PAMPs).
Abstract 171: Impact of the Mediterranean Diet on Apolipoprotein AI Kinetic in Men with Metabolic Syndrome
Authors: Richard Caroline , Couture Patrick , Desroches Sophie , Lamarche Benoît
Published: July 2021

The impact of the Mediterranean diet (MedDiet) on HDL metabolism has not been extensively studied to date. The objective of the study was to investigate the effect of the MedDiet consumed under controlled isoenergetic feeding conditions on HDL as well as on apolipoprotein (apo) AI kinetic in men with metabolic syndrome (MetS). The diet of 26 men aged between 24 to 62 years with the MetS (NCEP-ATP III) was first standardized to a North American control diet, which was consumed for 5 weeks. MedDiet was then consumed over a subsequent period of 5 weeks. Both diets were consumed under isoenergetic feeding conditions with all foods, including red wine, provided to participants. During the last week of each diet, participants received a single bolus of [5,5,5-
2
H
3
]
L
-leucine and fasting blood samples were collected at predetermined time points over a period of 96 hours. Kinetic parameters were derived using multicompartmental modeling of the enrichment data over time. Although no change in plasma HDL-C concentrations was observed, consumption of the MedDiet led to a significant reduction in plasma apoAI concentration and pool size (both
P
<0.05) compared with the control diet. The MedDiet was also associated with a trend towards a reduction in apoAI production rate (PR,
P
=0.07) but had no impact on apoAI fractional catabolic rate (FCR,
P
=0.64). However, only variations in apoAI FCR correlated with diet-induced variations in plasma HDL-C and in apoAI concentrations (
r
= -0.50 and
r
= -0.49 respectively,
P
<0.02). Based on the individual HDL-C response to MedDiet, responders and non-responders were identified. Participants among whom HDL-C concentrations were increased with MedDiet (mean ΔHDL-C: +9.9 ± 3.2 %) showed significantly greater reductions in apoAI FCR and in apoB and VLDL-TG concentrations (all
P
<0.04) than those among whom HDL-C levels were reduced after the MedDiet (mean ΔHDL-C: -11.1 ± 4.5 %). Data from this controlled feeding study suggest that the heterogeneous response of HDL-C and apoAI to MedDiet is primarily determined by variations in apoAI FCR, which in turn may be due to concurrent changes in plasma TG concentrations.
Abstract 175: Performance of a Multilocus Genetic Risk Score Derived from Top Signals in the Cardiogram+C4d Consortium in Predicting Incident Coronary Disease in the Atherosclerosis Risk in Communities Study
Authors: Assimes Themistocles L , Goldstein Benjamin ,   for the Cardiogram+C4D Consortium
Published: July 2021

Genome wide association studies (GWAS) to date have identified 30 CAD susceptibility loci but the ability to use this information to improve risk prediction remains limited. A meta-analysis of the GWAS and Cardio Metabochip data produced by the CARDIoGRAM+C4D consortium representing 63,253 cases and 126,820 controls has identified 1885 SNPs passing a False Discovery Rate (FDR) threshold of 0.5%. We hypothesized that an expanded multi locus genetic risk score (GRS) incorporating genotype information at all loci below an FDR of 0.5% would perform better than a GRS restricted to 42 loci reaching genome wide significance and tested this hypothesis in subjects of European ancestry participating in the Atherosclerosis Risk in the Community (ARIC) study. Models testing the GRS were either minimally (age and sex) or fully adjusted for traditional risk factors (TRFs). The Figure shows the hazard ratio (HZ) and 95% CI for incident events comparing each quintile of GRS to the middle quintile. The GRS including genotype information at all loci with an FDR of 0.5% noticeably improves risk prediction over the GRS restricted to genome wide significant loci in both the minimally and fully adjusted models based on several metrics including i) HR per GRS quintile, ii) the HR per SD of the GRS, and iii) the logistic regression pseudo R2, and iv) the c statistic. The HR per GRS quintile and per SD of GRS were all lower in the fully adjusted models compared to the respective minimally adjusted models but the reduction of the HR was more striking for the models that tested the more expansive GRS. These findings suggest that a larger proportion of novel GWAS CAD loci are mediating their effects through TRFs. While these findings demonstrate some progress in risk prediction using GWAS loci, both the limited and the expanded GRS continues to explain a relatively small proportion of the overall variance compared to TRF. Thus, the clinical utility of a CAD GRS remains to be determined.
Abstract 195: Peripheral Blood S100A8 and S100A12 Gene Expression Correlate with Coronary Calcium Score and Percent Diameter Stenosis in Patients by CT-Angiography
Authors: Wingrove James A , Elashoff Michael R , Voros Szilard , Thomas Gregory S , Rosenberg Steven
Published: July 2021

Background—
Coronary artery disease (CAD) can vary by coronary artery calcification (CAC) and extent of stenosis. A previously described peripheral blood 23-gene expression score (GES) was validated for discrimination of obstructive CAD and shown to correlate with maximum % diameter stenosis (%DS), however, its relation to CAC has not been analyzed in detail. S100A12, a component of the score, has been correlated with calcification in a transgenic mouse model.

Methods—
A total of 398 patients from the COMPASS trial (
NCT01117506
) had both core-lab analyzed CT-angiography (CTA) and GES. CAC was determined as whole-heart Agatston score and per-patient maximum %DS by CTA. GES was measured by RT-PCR according to Corus CAD protocols (CardioDx, Palo Alto, CA). Individual gene expression levels were analyzed for significance relative to CAC and %DS by age and sex-adjusted logistic regression.

Results—
Patients were 50% male; 50/398 had obstructive CAD (≥50% stenosis by core-lab CTA). Both CAC and %DS were highly correlated with overall GES (p< 10-16). Genes significantly associated with %DS were expressed predominantly in either lymphocyte or myeloid cells (circles and squares in figure respectively, bottom quadrants) whereas no lymphocyte genes and a larger set of myeloid-specific genes were associated with CAC (squares in figure, left quadrants); S100A8 and S100A12 showed the strongest associations with CAC (p = 0.006).

Conclusion—
Gene expression significance for %DS appears to reflect increased neutrophil to lymphocyte ratio whereas neutrophil gene up-regulation appears correlated with CAC, the strongest association being seen with S100A8 and S100A12.
Abstract 212: Thrombin Stimulation Induces de novo SDF-1a Synthesis and Alters MicroRNA Profile in Human Platelets
Authors: Huang Zhangsen , Rahman Mohammed Ferdous-Ur , Jiang Lei , Xie Hong , Caramuta Stefano , Lui Weng-Onn , Li Nailin
Published: July 2021

Platelets are anucleated cells, but still retain certain capacity of protein synthesis. Platelets are also known to contain microRNAs (miRNAs), which can negatively regulate mRNA translation/protein synthesis. We asked if platelet activation can initiate de novo protein synthesis of angiogenic regulators and if platelet activation induces changes of platelet miRNA expression. Platelet rich plasma was prepared from citrated blood of 12 healthy subjects. Platelets were purified by a second centrifugation and using leukocyte-depleting CD45-Dynabeads, and then treated without or with thrombin (0.1 U/ml, 30 min, 37°C). Platelet lysates were prepared immediately after treatments or after 16 h-culture for Western blottings of stromal cell derived factor-1a (SDF1a) and angiostatin. Total platelet RNA was isolated with a mirVana miRNA isolation kit, and platelet miRNA expression profiling was performed using an Agilent’s miRNA microarray system. Thrombin stimulation reduced platelet immunoblotting intensities/protein contents of SDF-1a and angiostatin as compared to unstimulated platelets, suggesting release of the angiogenic regulators upon platelet activation. SDF-1a, but not angiostatin, content was partially recovered after 16 h culture, indicating de novo protein synthesis. Using mature mRNA-specific primers, SDF-1a, but not angiostatin, mRNA was detected in thrombin-activated but not in unstimulated platelets. Furthermore, miRNA array analysis demonstrated that thrombin stimulation down-regulated a panel of platelet miRNA expression (e.g., miR-23a, miR-23b, miR-24, miR-106b, and miR-107) but also up-regulated a group of miRNA expression (e.g., miR-96, miR-212, miR-449a, and miR-629). In conclusion, thrombin stimulation induces mRNA splicing and protein synthesis of SDF-1a in platelets. Thrombin activation also alters platelet miRNA profile that may have a major impact on de novo protein synthesis in activated platelets.
Abstract 229: Shear-Induced Mac-1 Cleavage Influences Neutrophil-Platelet Adhesion
Authors: Zhang Xiaoyan , Zhan Dongying , Shin Hainsworth Y
Published: July 2021

INTRODUCTION.
Under physiologic (i.e., non-inflamed) conditions, fluid flow-derived shear stresses serve to minimize the activity of neutrophils in the blood to ensure their efficient transit through the microcirculation. In addition to preventing pseudopod formation, shear exposure has also been shown to cleave CD18 integrins on neutrophils. In fact, CD18 integrins, particularly LFA-1 and Mac-1, play a dominant role in neutrophil adhesion to other cells such as platelets in the vascular flow field. We, therefore, tested the hypothesis that shear-induced CD18 cleavage impacts neutrophil-platelet binding.

METHODS.
Mixed populations of leukocytes were exposed to constant shear fields of 2.5, 5, and 10 dyn/cm2 in a cone-plate viscometer for up to 10 min to characterize CD18 cleavage based on integrin subtypes. We also examined the role of CD18 cleavage in leukocyte-platelet binding using E64, a protease inhibitor previously shown to block CD18 proteolysis by shear.

RESULTS.
Shear-induced CD18 cleavage was leukocyte-specific and, beyond threshold levels, was independent of flow exposure time and magnitude. Furthermore, for neutrophils and monocytes that express LFA-1 and Mac-1 on their surfaces, shear stress elicited cleavage of Mac-1, but not LFA-1. In contrast, shear cleaved LFA-1 on lymphocytes, cells that do not exhibit detectable surface levels of Mac-1. Moreover, neutrophils, but neither monocytes nor lymphocytes, pretreated with E64 and exposed to shear exhibited significantly (p < 0.05) increased platelet binding and CD18 surface levels, compared to untreated cells.

DISCUSSION.
Shear-induced cleavage of CD18 is thus a complex process related to the differential expression of CD18 subtypes by different leukocyte subsets. Future work is needed to elucidate the underlying mechanism(s) involved. However, results of the present study further support that fluid shear stress mechanotransduction serves to negatively regulate the activation of neutrophils, the gatekeepers of the acute inflammatory processes. In light of the negative effects of leukocyte-platelet interactions on microvascular function, the results establish neutrophil responses to shear stress as critical mediators of blood homeostasis under physiologic conditions.
Abstract 241: Piggyback and Horseshoe Balloon Catheter Models for Simultaneous Thrombolysis and Venous Angioplasty in Acute Ileofemoral Venous Thrombosis After IVC Filter Insertion
Authors: Arokiaraj Mark , Guerrero Luis , Levine Robert , Palacios Igor
Published: July 2021

Background:
To investigate the potential role of balloon mediated thrombolysis and venous angioplasty in acute ileofemoral thrombosis and to develop novel balloon catheter models for the same purpose.

Methods:

2 patients and 1 patient on followup with extensive acute ileofemoral and popliteal vein thrombosis and partially extending into the inferior venacava (IVC) with diffuse swelling of lower limb and gluteal region were studied. The second patient stopped anticoagulation and presented with ileofemoral thrombosis in contralateral limb on followup. In both patients Gunther Tulip (Cook) IVC filter was placed. A 5F Multipurpose catheter with sideholes was placed in common iliac vein bifurcation and thrombolysis was done for 18 hours with streptokinase at 5000U/hr. Post thrombolysis IVC angiogram showed mild recanalisation of left common iliac veins leaving a stump. On the next day, the left common iliac vein was cannulated through a 5F Torcon catheter and a Terumo 035 J tipped wire was advanced through the clots. A 5cm x 4mm peripheral balloon was advanced and balloon directed 24 hour thrombolysis with streptokinase was done at 5000U/hr. The balloon was pulled back and multiple serial dilatations were done in femoral, internal iliac and common iliac veins. In both patients thrombolysis was started on the third day after the onset of symptoms.

Results:
Post procedure the venous channels were opened and were draining adequately. Limb edema subsided and there was no bleeding or embolic complications. Both patients are on oral anticoagulation and now on follow-up for 8 months being asymptomatic at present. Based on these interventions two novel balloon models to thrombolyse and to perform venous angioplasty simultaneously in a single procedure was developed. The first is a piggyback model which has a side port attached to the shaft of the balloon (5cm length and 4mm breath). The other model is a horse shoe balloon catheter which has a 14cm long and 4mm wide compliant balloon with 0.75mm diameter side port for thrombolysis till the balloon tip and on cross section gives a horse shoe appearance.

Conclusion:
Balloon mediated thrombolysis and venous angioplasty after IVC filter insertion is useful and novel balloon catheter models may be used in ileofemoral venous thrombosis.
Abstract 249: Stationary Signal and Flow Velocity Assessment by MRI of a New Nitinol Nanocomposite Polymer Stent-Graft
Authors: Desai Mital , Clough Rachel E , Gaddum Nicholas R , Rhode Kawal , Zhou Xiang , You Zhong , Seifalian Alexander M , Hamilton George
Published: July 2021

Objective:
To assess MRI compatibility and suitability of a new sutureless stent-graft made from Nitinol bonded to nanocomposite polymer (NP).

Methods:

1. Using MRI and Magnevist contrast, isotropic 3D T1-weighted FFE images of NP stent-graft were acquired to observe artefacts and stationary signal attenuation. Average signal magnitude was calculated. Medtronic ValiantTM was used as control.

2. In second stage, steady flow phantom was setup for flow-encoded MRI signal assessment of both stent-grafts. Baseline values were obtained by velocity measurements without stent-graft using identical settings. 2D through-plane phase contrast images were acquired and average velocity and amount of flow (flux) were calculated.

Results:
On static assessment of NP and ValiantTM stent-grafts no significant image artefacts were seen. The signal inside and outside the ValiantTM stent-graft was 644.2(SD 36.2) and 659.6(SD 85.8) respectively. The signal attenuation for this device was 2.39%. The signal inside and outside the NP stent graft was 1561.7(SD 31.2) and 1595.5(SD 40.8) respectively with comparable signal attenuation of 2.16%. In MRI velocity attenuation study, steady flow phantom was set at mean volume of 105.3 ml and mean velocity of 79.5 cm/sec. Flux measured in ValiantTM stent-graft was 102±2.27 ml/sec with no significant difference to baseline (104±1.98 ml/sec; P=0.892). Similarly flux for NP stent-graft at mean stroke volume 104.4 ml and mean velocity of 92.3 cm/sec showed no difference to baseline (99.8±2.4 vs. 104±0.96 ml/sec; P=0.176). There was no significant difference in flux between Medtronic and NP stent-grafts (102±2.27 vs. 99.8±2.4 ml/sec; P=0.328).

Conclusion:
NP stent-graft does not display any material-induced artefacts on MRI. On flow assessment, signal attenuation is comparable with the commercial device. These properties are important in developing this stent-graft, compliant, durable, visco-elastic, biocompatible and anti-thrombogenic, for future clinical use.
Abstract 25: Inhibition of VLDL Assembly by Apolipoprotein B Antisense Oligonucleotides Stimulates Autophagy
Authors: Conlon Donna M , Thomas Tiffany , Hernandez-Ono Antonio , Ruggles Kelly V , Ginsberg Henry
Published: July 2021

In order to investigate the effects of reduced VLDL secretion on hepatic lipid metabolism, we examined the effects of knockdown of either apolipoproteinB (apoB) or microsomal triglyceride transfer protein (MTP) using antisense oligonucleotides (ASO) for 6 weeks in apobec-1 knockout mice that only synthesize apoB100. Despite a similar decrease VLDL secretion in mice treated with apoB ASO as compared with MTP ASO, there was an increase in liver triglyceride (TG) content only in the MTP ASO-treated mice. There were no differences in either fatty acid (FA) uptake or secretion, or lipid synthesis from de novo lipogenesis, between the two groups to explain the difference in liver TG mass. In primary hepatocytes isolated from mice treated with apoB ASO, FA oxidation measured after a 16 hr steady state label with
14
C oleic acid showed a 3 fold increase in FA oxidation versus cells from control ASO-treated mice. A labeled time course study showed that the increase in FA oxidation was delayed, indicating compartmentalization of lipid in the apoB ASO-treated hepatocytes. Electron microsopy (EM) showed swollen endoplasmic reticulum (ER) and increased autophagosomes in the apoB ASO hepatocytes. The latter was confirmed by an increase in immunofluoresent staining for the autophagy marker LC3b. The LC3b protein was perinuclear suggesting that it was present on mature autophagolysosomes. Treatment with lysosomal inhibitors showed that the accumulation of LC3b was not due to a defect in autophagic flux in these hepatocytes. Autophagosomes in the EMs contained large double membrane structures suggestive of ER. In primary hepatocytes from apoB ASO-treated mice, labeling with ER Tracker showed abnormal aggregates of ER. In addition, immunofluorescent staining studies showed that these abnormal ER aggregates, as represented by calnexin staining, co-localized with the LC3b protein. We propose that autophagy of lipid-filled ER, with subsequent lipolysis of TG in the autophagolysosome and later oxidation of released FA, prevent hepatic steatosis in mice treated with apoB ASO.
Abstract 253: Abdominal Aortic Aneurysms: Protein Targets for Autoimmunity
Authors: Ghosh Abhijit , Pechota Angela , Futchko John S , Sadiq Omar , Henke Peter K , Upchurch Gilbert R , Eliason Jonathan L
Published: July 2021

Objectives:
The vast majority of Abdominal Aortic Aneurysm (AAA) patients have a history of smoking. The current hypothesis is that smoking induces post-translational protein modifications within the abdominal aorta resulting in site-specific antigenic targets for humoral immunity, and leads to a complex inflammatory milieu that ultimately gives rise to mature AAAs.

Methods:
Plasma samples from patients with AAAs were separated by smoking status (Non-smoker = NS [n = 5]; Smoker = S [n = 15]; Prior Smoker = PS [n = 36]). Aortic wall was harvested from AAA (n = 5) and healthy control aorta (n = 5). Membrane proteins were extracted from AAA aortas by phase separation and bound to affinity columns. Plasma from NS, S, and PS groups was passed through these columns to isolate immunoglobulins (eluted IgGs). Duplicate samples of pooled control aortic tissue proteins underwent electrophoresis for Western blotting and Coomassie staining. Western blots were developed with eluted IgGs from the NS, S, and PS groups as well as IgGs from healthy volunteers as negative control. The Western blots were analyzed for differences in banding patterns between NS and S or PS groups and the corresponding proteins from Coomassie stained gels were excised for Mass Spectrometry (LC-MS/MS analysis).

Results:
Western blot experiments revealed a ∼38 kD band in NS but no correlating band in S and PS groups, as well as ∼22 kD and ∼33 kD bands present in S and PS but no correlating bands in the NS group. LC-MS/MS analysis of these 3 bands identified the encompassed proteins as having sequence homologies with TROPOMYOSIN 1, TROPOMYOSIN 2, TRANSGELIN, INTEGRIN BETA-1, VERSICAN, PEROXIREDOXIN 2 and OSTEOGLYCIN (Mimecan), and that these proteins differed in relative abundance between the three groups.

Conclusions:
We identified putative proteins in normal human aortas that could represent autoimmune targets leading to AAA development. The discrepancy between the molecular weights of putative targets and the bands used for LC-MS/MS analysis possibly reflects post-translational processing of the larger parent protein resulting in auto-antigenicity.
Abstract 255: Induction of microRNA-21 Inhibits Abdominal Aortic Aneurysm Development and Nicotine-Augmented Expansion
Authors: Maegdefessel Lars , Azuma Junya , Toh Ryuji , Deng Alicia , Merk Denis , Raiesdana Azad , Leeper Nicholas J , Raaz Uwe , Schoelmerich Anke M , McConnell Michael V , Dalman Ronald L , Spin Joshua M , Tsao Philip S
Published: July 2021

Identification and treatment of abdominal aortic aneurysm (AAA) remain among the most prominent challenges in vascular medicine. MicroRNAs (miRs) are crucial regulators of cardiovascular pathology, and represent possible targets for the inhibition of AAA expansion. We identified miR-21 as a key modulator of proliferation and apoptosis in developing AAA in two established murine models: porcine-pancreatic-elastase, and angiotensin II-infusion. In both models, miR-21 increased with AAA development. Lentiviral overexpression of miR-21 (pre-21) induced cell proliferation and decreased apoptosis in the aortic wall, with protective effects on aneurysm expansion (as shown in Picrosirius Red stained images in the attached Figure below). miR-21 overexpression substantially decreased phosphatase and tensin homolog (PTEN), leading to increased levels of p-AKT, a known pro-proliferative and anti-apoptotic pathway. Systemic injection of a locked-nucleic-acid-modified antagomiR targeting miR-21 (anti-21) diminished the pro-proliferative impact of down-regulated PTEN, leading to significantly increased AAA size as compared to scrambled-control-miR (scr-miR). Importantly, similar results were seen in nicotine-augmented murine AAAs, while parallel findings were observed in human aortic tissue samples from patients undergoing surgical AAA repair (with more pronounced effects in smokers). In vitro studies using human aortic smooth muscle cells, fibroblasts as well as endothelial cells identified NFκB signaling pathways as the key regulator of miR-21 induction. Modulation of miR-21 expression shows great potential as a novel and powerful therapeutic option to limit AAA disease progression.
Abstract 257: Apolipoprotein M Is Not Present in Prebeta-1 HDL Particles
Authors: Freeman Lita A , Shamburek Robert , Aponte Angel , Kato Gregory J , Remaley Alan T
Published: July 2021

BACKGROUND:
Apolipoprotein M (apoM) is a 25 kD plasma protein present mainly in HDL. It has a hydrophobic pocket for carrying ligands variously reported as retinol, all-
trans
-retinoic acid, 9-
cis
-retinoic acid, sphingosine-1-phosphate (S1P) and oxidized phospholipids. In addition to mediating the effects of S1P and modulating oxidative stress, apoM has been reported to enhance cholesterol efflux and to increase plasma levels of small, preβ1 HDL, a particle that efficiently accepts cholesterol effluxed from cholesterol-loaded cells and plays a key role in reverse cholesterol transport. ApoM is present in α-migrating HDL particles but whether it is also present in small preβ1 HDL particles is disputed. Establishing the absence or presence of apoM in preβ1 HDL particles is essential for understanding its role in reverse cholesterol transport.

METHODS:
We performed native-native 2D gel electrophoresis on healthy volunteer plasma to separate native HDL particles by size and charge. Particles were blotted onto a membrane and probed with antibodies to apoM or apoA-I to identify specific HDL particles associated with apoM. Similar experiments were performed with plasma from patients with apoE-deficiency or from patients with low plasma levels of apoA-I and HDL. We also performed native 1D electrophoresis to visualize lipoprotein particles containing apoM. Finally, native-native 2D gels of purified HDL were used for proteomics of preβ1 particles.

RESULTS:
apoM was present in two large α-migrating HDL particles and in LDL-sized particles, as well as in one small particle that did not contain apoA-I. apoA-I but not apoE was required for formation of the large apoM-containing HDL particles. The small apoM particle was unaffected in apoA-I- and apoE-deficient patients. apoM was not present in preβ1 particles.

CONCLUSION:
apoM is not a stable component of small preβ1 apoA-I-containing HDL particles but instead resides mainly in two large HDL molecules and in LDL-sized particles, as well as a small particle that does not contain apoA-I. The role of apoM in cholesterol efflux requires further evaluation.
Abstract 263: Isotopic Labeling and Chemical Cross-Linking Reveals Intermolecular Contacts and Dynamics of Apolipoprotein A-I Structure in Reconstituted HDL Particles
Authors: Morris Jamie , Jones Martin K , Ren Gang , Segrest Jere , Davidson W Sean
Published: July 2021

Apolipoprotein (apo)A-I has been proposed to adopt a number of different, but related, structures when in contact with lipid. The technique of chemical cross-linking has recently been used to determine the spatial relationships between two molecules of apoA-I in reconstituted high density lipoprotein (rHDL) particles. However, this technique is limited in that it cannot unequivocally distinguish between intramolecular and intermolecular contacts. To address this issue, we have produced two forms of recombinant apoA-I that contain the naturally occurring isotope of nitrogen (N14) or a stable isotope (N15). These forms were mixed 1:1 and then used to produce reconstituted HDL particles with synthetic lipids. The resulting mass shifts (readily detectable in the mass spectrometer) were exploited to unambiguously distinguish between intramolecular (N14 to N14 or N15 to N15) and intermolecular (N14 to N15) cross-linked peptides. An additional benefit of this approach was the ability to identify cross-links with high certainty without the need for peptide fragmentation, allowing for dramatic increases in method sensitivity. We studied highly homogeneous rHDL particles made with the fully saturated phospholipid palmitoyl steroyl phosphatidylcholine (PSPC) to minimize apoA-I conformational dynamics. These particles were 98Å in diameter, contained two molecules of apoA-I, approximately 155 molecules of PC, and were discoidal in shape by cryo EM. We identified 30 cross-links (17 intramolecular, 13 intermolecular) that were overall consistent with the double belt model in which both apoA-I molecules wrap around a bilayer of lipids in an antiparallel orientation. Unambiguous intramolecular linkages between the N- and C-terminal regions of apoA-I were inconsistent with the ‘double super helix’ variant of the belt model. We identified several low abundance cross-links that suggest that the N-terminus may be conformationally dynamic and may spend some time folded back across the molecule as proposed for the ‘belt and buckle’ belt model.
Abstract 271: Mechanisms for the Generation of Potently Proteolytic Microvesicles from Human Macrophages After Tobacco Smoke Exposure: A Potential Role in Plaque Destabilization
Authors: Li Chunjun , Liu Yu , Yu Demin , Williams Kevin J , Liu Minglin
Published: July 2021

BACKGROUND—
Cigarette smoking greatly increases the risk of atherosclerotic plaque rupture and subsequent intravascular thrombosis, but the underlying mechanisms remain poorly understood. We recently reported that tobacco smoke induces human monocytes and macrophages to generate tissue factor-positive, procoagulant microvesicles (MVs, also known as microparticles).

AIMS—
We now sought to determine whether exposure of human macrophages to tobacco smoke induces the release of MVs with proteolytic activity, what the nature of the major proteases on smoke-induced MVs might be, and what cellular mechanisms might be responsible for their production and release.

METHODS/RESULTS—
We found that MVs released from human macrophages after exposure to tobacco smoke extract (TSE) carry substantial gelatinolytic and collagenolytic activities that, surprisingly, can be attributed to a single, dominant, transmembrane protease of the matrix metalloproteinase (MMP) superfamily - namely, MMP14 (also known as membrane type 1-MMP). Flow cytometric counts revealed that exposure of human macrophages to TSE for 20h more than quadrupled their production of MMP14-positive MVs (control: 1112±231, TSE-induced: 5823±2192 MMP14-positive MVs per μl of conditioned medium, mean±SEM, n=6, P<0.01). Based on our biochemical and confocal studies, the production of these MVs relies on a series of dynamic, regulated steps that include activation of the JNK and p38 MAP kinases, MAPK-dependent induction of cellular MMP14, cleavage of pro-MMP14 into its active mature form, a remarkable trafficking of MMP14 into nascent plasma membrane blebs, and finally caspase- and MAPK-dependent apoptosis and apoptotic blebbing.

CONCLUSION—
The ability of tobacco smoke to induce expression of MMP14 by human macrophages, and then the activation and export of these molecules on MVs, may be novel contributors to increased risk of atherosclerotic plaque destabilization. Proteolytically active MVs induced by tobacco smoke may be novel mediators of matrix destruction in a variety of locations, including the fibrous cap of atheromata.
Abstract 275: Angioscore Balloon in the Treatment of Collagen Plug Occlusion and Acute Limb Ischemia: Case Report
Authors: Swamy Pooja M , Berry Abeer , Elder Mahir D
Published: July 2021

BACKGROUND:
Complications of the vascular access-site (VAS) are not uncommon. With the evolution of hemostatic techniques used in the access site closure, in the last two decades, the rate of VAS related complications has significantly reduced from 6% to 2%. However, they still remain to be an important cause of morbidity following catheterization procedures. The most common complications encountered with closure of VAS are hematoma formation, arterio-venous fistula, dissection, pseudo -aneurysm and limb ischemia. According to two meta-analyses, the incidences of these complications were very low. The incidence of collagen plug from an Angioseal(™) device causing acute leg ischemia is low and upon occurrence, the use of an Angioscore(™) balloon in successful revascularization has never been reported.

CASE PRESENTATION:
A 62-year-old male with known severe peripheral artery disease, diabetes mellitus, hypertension and hypercholesterolemia had a successful angioplasty of a 100% chronically occluded right superficial femoral artery (SFA) via the left common femoral artery. An Angioseal (™) closure device was used to achieve hemostasis. The patient was discharged home after an uneventful post procedural course. Two days later, he presented to the ER with a cold and numb left lower extremity. On exam, the left lower extremity had no palpable pulse from below right femoral artery, confirmed by Doppler. The extremity was cold to touch with decreased sensory perception. Patient was found to have critical left lower extremity ischemia. He was emergently taken for a selective left lower extremity angiogram using the right common femoral artery for access. Fragments of the closure device and a collagen plug causing a total occlusion of the left common femoral artery were found. After a pre-dilatation with a 4.0x 40 balloon under prolonged inflations, a lesion reduction from 100 % to 30% with a TIMI 0 to TIMI 3 flow was achieved using an Angioscore (™) 5.0x 40 balloon inflated at 10 atmospheres. Subsequently, using laser 2.0 atherectomy of the left common femoral artery was performed. Flow in the dorsalis pedis artery was confirmed with Doppler.

DISCUSSION:
The Angio-Seal(™) device has a polylactide and polyglycolide polymer anchor, a collagen plug and a suture contained within a carrier system. Hemostasis is achieved by compressing the arterial puncture site between the anchor and the collagen plug. With newer studies, it appears that the occurrence of critical limb ischemia from collagen plug is under recognized. We therefore, with this case report urge the physicians to be aware of this serious though rare complication of closure devise and also highlight the successful use of Angioscore (™) balloon in the emergent treatment of non-athermatous vascular occlusion causing critical limb ischemia.
Abstract 276: Tissue Engineering a Small Diameter Vascular Graft
Authors: Tatterton Mark R , Wilshaw Stacy-Paul , Ingham Eileen , Homer-Vanniasinkam Shervanthi
Published: July 2021

Introduction
The patency rate of synthetic small diameter grafts for coronary and peripheral arterial bypass remains poor. The aim of this study was to engineer an acellular, biocompatible conduit with biomechanical properties similar to native artery and investigate the regenerative capacity of the conduit using ovine vascular cells.

Methods
Porcine carotid arteries were harvested and decellularized using an established protocol. In short, arteries were treated sequentially with EDTA, hypotonic buffer, 0.1% (w/v) sodium dodecyl sulphate (SDS), DNase and RNase, hypertonic buffer and sterilised using 0.1% (v/v) peracetic acid. In order to determine the biomechanical properties of the acellular arteries, suture retention strength, ultimate tensile strength and burst pressure measurements were performed in comparison to native tissue.

Ovine endothelial cells were harvested from the femoral arteries of sheep following digestion with collagenase. Ovine smooth muscle cells were isolated from ovine arterial explant cultures. The phenotype of the cells was confirmed using antibodies to ovine vascular cell markers (myosin, α-actin, VWF, CD62) by indirect immunofluorescence..

Biocompatability of the scaffolds was assessed using contact and extract cytotoxicity tests with two cell lines (BHK and 3T3) and primary ovine vascular cells (endothelial and smooth muscle cells). The capacity of the acellular arteries to support vascular cell adhesion was determined by seeding cells onto the scaffolds and evaluation using scanning electron microscopy (SEM)..

Results
Histiological characterization and DNA quantification confirmed successful decellularization of porcine carotid arteries. Decellularized vessels were shown to retain the biomechanical strength and properties of native vessels. Decellularized arteries displayed no evidence of cytotoxicity to cell lines or primary vascular cells. Initial cell adhesion studies confirmed successful adherence of ovine vascular cells to decellularized arteries.

Conclusion
The study resulted in an acellular, biocompatible scaffold that retained the biomechanical properties of the native artery. Initial re-cellularization studies with ovine vascular cells was successful.
Abstract 277: The Relationship Between Aortic And PA Diameter Among Individuals With Genetic Conditions Of The Thoracic Aorta: A Report From The NIH Gentac Registry
Authors: Tantawy Emad M , Asch Federico M , Weissman Gaby , Weigold Wm Guy , LeMaire Scott A , Devereux Richard , Pyeritz Reed , Eagle Kim , Kroner Barbara , Taylor Allen J
Published: July 2021

Background
The aorta and pulmonary artery (PA) share structural similarities, and thus genetic conditions affecting the thoracic aorta may also affect the PA. We evaluated the relationship between aortic and pulmonary artery dimensions on chest CT among a subset of participants in the Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions Registry (GenTAC).

Methods
Data Adults in GenTAC without a history of aortic surgery or aortic dissection (N = 144) and with computed tomography of the chest were included. Standardized double oblique measurements of the pulmonary artery, and thoracic aortic dimensions at 8 sites (sinus of Valsalva through the suprarenal aorta) were measured in a core laboratory. The relationship between the PA and aortic dimensions were analyzed using bivariate correlations, and multivariable linear regression controlling for age and body size.

Results
Mean age was 45±13 years. The mean maximum ascending aortic dimension was 3.8±0.9 cm (range 2.4-7.9 cm); mean PA dimension was 3.1±0.5 cm (1.8-4.8 cm). Using a cutoff of 2.8 cm defining the 90
th
percentile value for PA diameter, 65% of the study population had dilated PA. Correlations between the aortic and pulmonary artery diameter were higher for the descending aorta than the ascending aorta. The highest observed correlation between PA and aortic diameter was observed for the thoracoabdominal aorta at the level of the diaphragm (r = 0.40; P <0.001). In a linear regression model evaluating relationships between PA diameter and various aortic segments, after controlling for age and body size, the PA and descending thoracic aorta were independently related (partial correlation r = 0.28; P<0.001). Similar relationships were not observed for the ascending aorta.

Conclusions
A dilated PA is common among individuals with genetically-associate thoracic aortic dilatation. The diameter of the PA relates modestly to aortic dimensions, most strongly with the descending thoracic aorta.