luminal diameter
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2022 ◽  
Vol 8 ◽  
Author(s):  
Elizabeth Andraska ◽  
Nolan Skirtich ◽  
Dylan McCreary ◽  
Rohan Kulkarni ◽  
Edith Tzeng ◽  
...  

Background: During arteriogenesis, outward remodeling of the arterial wall expands luminal diameter to produce increased conductance in developing collaterals. We have previously shown that diameter expansion without loss of internal elastic lamina (IEL) integrity requires both degradation of elastic fibers and LOX-mediated repair. The aim of this study was to investigate the expression of genes involved in remodeling of the extracellular matrix (ECM) using a model of arteriogenesis.Methods: Sprague-Dawley rats underwent femoral artery ligation with distal arteriovenous fistula (FAL + AVF) placement. Profunda femoral arteries (PFA) were harvested for analysis at various time points. Serum desmosine, an amino acid found exclusively in elastin, was evaluated with enzyme-linked immunosorbent assay (ELISA) as a marker of tissue elastolysis. Tissue mRNA isolated from FAL + AVF exposed PFAs was compared to the contralateral sham-operated using qPCR. HCAECs were cultured under low shear stress (8 dyn·s/cm2) for 24 h and then exposed to high shear stress (40 dyn·s/cm2) for 2–6 h. Primers used included FBN-1, FBN-2, Timp-2, LOX-1, Trop-E, Cath-K, Cath-S, MMP-2, MMP-9, FBLN-4, and FBLN-5 and were normalized to GAPDH. mRNA fold changes were quantified using the 2-ΔΔCq method. Comparisons between time points were made with non-parametric ANOVA analysis with Bonferroni adjustment.Results: PFAs showed IEL reorganization during arteriogenesis. Serum desmosine levels are significantly elevated at 2 days and one week, with a return to baseline thereafter (p < 0.01). Expression of ECM structural proteins (FBN-1, FBN-2, FBLN-4, FBLN-5, Tropoelastin, TIMP-2, LOX-1) and elastolytic proteins (MMP-2, MMP-9, Cathepsin S, Cathepsin K) exhibited an early peak (p < 0.05) relative to sham PFAs. After two weeks, expression returned to baseline. HCAECs demonstrated upregulation of FBN-2, FBLN-5, LOX-1 and Trop-E at 4 h of high shear stress, as well as elastolytic protein MMP-2.Conclusions: Elastin degradation begins early in arteriogenesis and is mediated by local upregulation of elastolytic genes. Elastolysis appears to be simultaneously balanced by production of elastic fiber components which may facilitate stabilization of the IEL. Endothelial cells are central to initiation of arteriogenesis and begin ECM remodeling in response to altered shear stress.


2022 ◽  
Vol 2022 ◽  
pp. 1-7
Author(s):  
Hengdao Liu ◽  
Hailong Tao ◽  
Xufei Han ◽  
Yang Lu ◽  
Xiaofei Xue ◽  
...  

Background. Drug-eluting stent (DES) plus drug-coated balloon (DCB) is a safe and effective treatment strategy for coronary artery bifurcation lesions, but there is no report about this strategy being used for left main (LM) bifurcation lesions. We aim to explore the efficacy and safety of DES plus DCB in the treatment of LM bifurcation lesions. Methods. A total of 100 patients diagnosed with LM bifurcation lesions by coronary angiography were retrospectively enrolled at our center from January 2018 to December 2019. They received either a two-stent strategy or a main branch (MB) stenting plus side branch (SB) DCB strategy and were accordingly divided into the 2-DES group and the DES + DCB group. Patients treated with DES + DCB were compared with a cohort of matched patients treated with a 2-DES strategy. Clinical data was collected and quantitative coronary analysis was performed. Results. For immediate postoperative angiography, though the two groups had no differences in the minimal luminal diameter (MLD) and luminal stenosis of MB, the DES + DCB group had significantly lower SB ostial MLD and a higher degree of residual lumen stenosis than the 2-DES group ( P < 0.05 ). At the time of follow-up, the SB ostial MLD of the DES + DCB group was higher than that of the 2-DES group, but lumen stenosis, late lumen loss (LLL), and LLL at the distal end of the left MB were all smaller than those of the 2-DES group ( P s < 0.05 ). Furthermore, the incidence of lumen restenosis and MACE between the two groups had no significance. Conclusion. The combination of DES and DCB is relatively safe and effective for the treatment of LM bifurcation lesions, and this strategy seems to have advantages in reducing LLL at the SB ostium.


2021 ◽  
Vol 12 (1) ◽  
pp. 346
Author(s):  
Jeon Min Kang ◽  
Dongwook Oh ◽  
Song Hee Kim ◽  
Dae Sung Ryu ◽  
Yubeen Park ◽  
...  

This study investigated whether interwoven self-expandable metallic stent (I-SEMS) placement suppresses stent-induced tissue hyperplasia compared with conventional knitted self-expandable metallic stent (K-SEMS) placement in a rat esophageal model. Twelve rats were randomly assigned to the I-SEMS (n = 6) and K-SEMS (n = 6) groups. All rats were sacrificed 4 weeks after the stent placement. The degree of stent-induced tissue hyperplasia on esophagography and histologic examination was compared between the groups. Stent placement was technically successful in all rats. Esophagography revealed significantly greater mean luminal diameter of the stented esophagus in the I-SEMS group than in the K-SEMS group (p < 0.001). Histologic examination revealed a significantly lower percentage of tissue hyperplasia area and a significantly thinner submucosal fibrosis in the I-SEMS group than in the K-SEMS group (all p < 0.001). There were no significant differences in the thickness of the epithelial layers (p = 0.290) and degree of inflammatory cell infiltration (p = 0.506). Formation of stent-induced tissue hyperplasia was evident with both I-SEMS and K-SEMS. Placement of I-SEMSs with a small cell size and high flexibility seems to be effective in suppressing stent-induced tissue hyperplasia compared with placement of K-SEMSs in rat esophageal models.


Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Ryan M. McEnaney ◽  
Dylan D. McCreary ◽  
Nolan O. Skirtich ◽  
Elizabeth A. Andraska ◽  
Ulka Sachdev ◽  
...  

When a large artery becomes occluded, hemodynamic changes stimulate remodeling of arterial networks to form collateral arteries in a process termed arteriogenesis. However, the structural changes necessary for collateral remodeling have not been defined. We hypothesize that deconstruction of the extracellular matrix is essential to remodel smaller arteries into effective collaterals. Using multiphoton microscopy, we analyzed collagen and elastin structure in maturing collateral arteries isolated from ischemic rat hindlimbs. Collateral arteries harvested at different timepoints showed progressive diameter expansion associated with striking rearrangement of internal elastic lamina (IEL) into a loose fibrous mesh, a pattern persisting at 8 weeks. Despite a 2.5-fold increase in luminal diameter, total elastin content remained unchanged in collaterals compared with control arteries. Among the collateral midzones, baseline elastic fiber content was low. Outward remodeling of these vessels with a 10–20 fold diameter increase was associated with fractures of the elastic fibers and evidence of increased wall tension, as demonstrated by the straightening of the adventitial collagen. Inhibition of lysyl oxidase (LOX) function with β-aminopropionitrile resulted in severe fragmentation or complete loss of continuity of the IEL in developing collaterals. Collateral artery development is associated with permanent redistribution of existing elastic fibers to accommodate diameter growth. We found no evidence of new elastic fiber formation. Stabilization of the arterial wall during outward remodeling is necessary and dependent on LOX activity.


2021 ◽  
Author(s):  
Chenhui Wang ◽  
Allan C. Spradling

AbstractDrosophila renal stem cells (RSCs) contradict the common expectation that stem cells maintain tissue homeostasis. RSCs are abundant, quiescent and confined to the peri-ureter region of the kidney-like Malpighian tubules (MTs). Although derived during pupation like intestinal stem cells, RSCs initially remodel the larval MTs only near the intestinal junction. However, following adult injury to the ureter by xanthine stones, RSCs remodel the damaged region in a similar manner. Thus, RSCs represent stem cells encoding a developmental redesign. The remodeled tubules have a larger luminal diameter and shorter brush border, changes linked to enhanced stone resistance. However, RSC-mediated modifications also raise salt sensitivity and reduce fecundity. Our results suggest that RSCs arose by arresting developmental progenitors to preserve larval physiology until a time in adulthood when it becomes advantageous to complete development by RSC activation.One-Sentence SummaryActivated Drosophila renal stem cells rebuild the adult Malphigian tubules using a less efficient but more stone-resistant design.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Ivan Dudurych ◽  
Antonio Garcia-Uceda ◽  
Zaigham Saghir ◽  
Harm A. W. M. Tiddens ◽  
Rozemarijn Vliegenthart ◽  
...  

AbstractAirways segmentation is important for research about pulmonary disease but require a large amount of time by trained specialists. We used an openly available software to improve airways segmentations obtained from an artificial intelligence (AI) tool and retrained the tool to get a better performance. Fifteen initial airway segmentations from low-dose chest computed tomography scans were obtained with a 3D-Unet AI tool previously trained on Danish Lung Cancer Screening Trial and Erasmus-MC Sophia datasets. Segmentations were manually corrected in 3D Slicer. The corrected airway segmentations were used to retrain the 3D-Unet. Airway measurements were automatically obtained and included count, airway length and luminal diameter per generation from the segmentations. Correcting segmentations required 2–4 h per scan. Manually corrected segmentations had more branches (p < 0.001), longer airways (p < 0.001) and smaller luminal diameters (p = 0.004) than initial segmentations. Segmentations from retrained 3D-Unets trended towards more branches and longer airways compared to the initial segmentations. The largest changes were seen in airways from 6th generation onwards. Manual correction results in significantly improved segmentations and is potentially a useful and time-efficient method to improve the AI tool performance on a specific hospital or research dataset.


Author(s):  
Ryan M McEnaney ◽  
Dylan D McCreary ◽  
Nolan Skirtich ◽  
Elizabeth Andraska ◽  
Ulka Sachdev ◽  
...  

When a large artery becomes occluded, hemodynamic changes stimulate remodeling of arterial networks to form collateral arteries in a process termed arteriogenesis. However, the structural changes necessary for collateral remodeling have not been defined. We hypothesize that decon-struction of the extracellular matrix is essential to the remodeling of smaller arteries into effective collaterals. Using multiphoton microscopy, we analyzed collagen and elastin structure in maturing collateral arteries isolated from ischemic rat hindlimbs. Collateral arteries harvested at different timepoints showed progressive diameter expansion associated with striking rearrangement of in-ternal elastic lamina (IEL) into a loose fibrous mesh, a pattern persisting at 8 weeks. Despite a 2.5-fold increase in luminal diameter, total elastin content remained unchanged in collaterals compared with control arteries. Among the collateral midzones, baseline elastic fiber content is low. Outward remodeling of these vessels with a 10-20 fold diameter increase was associated with fractures of the elastic fibers and evidence of increased wall tension as demonstrated by straight-ening of the adventitial collagen. Inhibition of lysyl oxidase (LOX) function with &beta;-aminopropionitrile resulted in severe fragmentation or complete loss of continuity of the IEL in developing collaterals. Collateral artery development is associated with permanent redistribution of existing elastic fibers to accommodate diameter growth. We found no evidence of new elastic fiber formation. Stabilization of the arterial wall during outward remodeling is necessary and dependent on LOX activity.


2021 ◽  
Vol 5 ◽  
pp. 75-80
Author(s):  
Samson Omini Paulinus ◽  
Benjamin Effiong Udoh ◽  
Samuel A. Efanga ◽  
Gabriel Udo Udo-Affah ◽  
Eru Mba Eru ◽  
...  

Objectives: Stroke or cerebrovascular accident is associated with defects in the circle of Willis; the vascular network that supplies the brain. There is currently lack of literature on the involvement of the circle of Willis in patients with stroke or its association with impending stroke. The objective of the study was to evaluate luminal diameter of arteries that constitute the circle of Willis in patients with stroke using computed tomography angiography (CTA) and magnetic resonance imaging (MRI) scans. Material and Methods: Angiograms of 340 male and female patients aged 15–>75 (40.18 ± 1.1 and 43.68 ± 1.18) years with suspected stroke, referred for either brain CTA or MRI in selected hospitals/diagnostic centers in Nigeria were evaluated using RadiAnt and the MicroDicom viewer software applications. A retrospective descriptive research design was adopted with approval from the federal health research ethics committee. Direct measurement of luminal diameter of major arteries of the circle of Willis was done using SPSS version 25 at P < 0.05. Results: From the 340 images assessed, 256 (75.29%) patients had ischemic stroke with luminal diameter of arteries of the circle of Willis ranged from 1 mm to >3 mm while 84 (24.71%) patients were without stroke with luminal diameter ranged from 1 mm to 2.11 mm (P < 0.05). Conclusion: Patients with stroke have larger luminal diameter of arteries that form the circle of Willis when compared to patients without stroke. The study has established for the 1st time, luminal diameter of circle of Willis that may be an index in the sampled Nigerian population.


Author(s):  
Takahisa Mori ◽  
Kazuhiro Yoshioka ◽  
Yuhei Tanno ◽  
Shigen Kasakura ◽  
Yuichi Miyazaki

Abstract Objectives Angiographic “slow flow” in the middle cerebral artery (MCA), caused by carotid stenosis, may be associated with high oxygen extraction fraction (OEF). If the MCA slow flow is associated with a reduced relative signal intensity (rSI) of the MCA on MR angiography, the reduced rSI may be associated with a high OEF. We investigated whether the MCA slow flow ipsilateral to carotid stenosis was associated with a high OEF and aimed to create a practical index to estimate the high OEF. Methods We included patients who underwent digital subtraction angiography (DSA) and MRA between 2015 and 2019 to evaluate carotid stenosis. MCA slow flow by image count using DSA, MCA rSI, minimal luminal diameter (MLD) of the carotid artery, carotid artery stenosis rate (CASr), and whole-brain OEF (wb-OEF) was evaluated. When MCA slow flow was associated with a high wb-OEF, the determinants of MCA slow flow were identified, and their association with high wb-OEF was evaluated. Results One hundred and twenty-seven patients met our inclusion criteria. Angiographic MCA slow flow was associated with high wb-OEF. We identified MCA rSI and MLD as determinants of angiographic MCA slow flow. The upper limits of MCA rSI and MLD for angiographic MCA slow flow were 0.89 and 1.06 mm, respectively. The wb-OEF was higher in patients with an MCA rSI ≤ 0.89 and ipsilateral MLD ≤ 1.06 mm than patients without this combination. Conclusions The combination of reduced MCA rSI and ipsilateral narrow MLD is a straightforward index of high wb-OEF. Key Points • The whole-brain OEF in patients with angiographic slow flow in the MCA ipsilateral to high-grade carotid stenosis was higher than in patients without it. • Independent determinants of MCA slow flow were MCA relative signal intensity (rSI) on MRA or minimal luminal diameter (MLD) of the carotid stenosis. • The wb-OEF was higher in patients with an MCA rSI ≤ 0.89 and ipsilateral MLD ≤ 1.06 mm than patients without this combination.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Wiessman ◽  
Y Aviv ◽  
G Shafir ◽  
R Kornowski ◽  
A Hamdan

Abstract Introduction A lower prevalence of coronary artery disease (CAD) was previously reported among bicuspid aortic valve (BAV) patients compared with tricuspid aortic valve (TAV) patients undergoing surgical aortic valve replacement. Unknown is the prevalence of CAD among BAV patients undergoing transcatheter aortic valve implantation (TAVI). Methods Consecutive BAV patients undergoing cardiac computed tomography angiography (CCTA) before TAVI were included. Studies with insufficient imaging quality were excluded. Forty-nine patients with history of prior percutaneous coronary intervention or coronary artery bypass graft surgery were also excluded. Coronary artery stenosis was categorized as ≤50% or &gt;50% luminal diameter stenosis. Results One hundred and fourteen consecutive BAV patients were enrolled (age 72±10.4 years, 64% males). BAV type 1A was the most common type (62%), followed by BAV type 0 (18%) and type 1C (10%). Cardiovascular risk factors were frequent: 23% (26) had history of diabetes mellitus, 45% (51) had dyslipidemia, 56% (64) had hypertension, and 25% (29) were current or past smokers. No correlation was found between calcium scoring of the aortic valve (3664.49±1671.01 Agatston Units) and calcium scoring of the coronary arteries (410.51±546.59 Agatston Units), correlation coefficient 0.43 (p=0.68). Obstructive coronary artery stenosis (&gt;50% luminal diameter stenosis) was observed among the minority (16%) of BAV patients. A single vessel disease was found in 7% of BAV patients, two vessels disease in 5% and triple vessels disease in 4%. Three BAV patients had a single vessel chronic total occlusion. Conclusion Among patients with BAV referred for TAVI, CCTA showed a low prevalence of obstructive coronary artery disease. The absence of correlation between aortic valve and coronary artery calcium scoring suggests the possibility of two heterogeneous aspects of the complex BAV disease. FUNDunding Acknowledgement Type of funding sources: None.


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