scholarly journals A case in which increasing the outer diameter of the venous needle was found to be effective at treating intimal hyperplasia and stenosis

2021 ◽  
Vol 54 (7) ◽  
pp. 369-374
Author(s):  
Yoshiaki Ito ◽  
Akihiro Fujiwara ◽  
Toshiyuki Tanaka ◽  
Atsuo Adachi
Keyword(s):  
Intimal Hyperplasia ◽  
Outer Diameter

Abstract 214: Protein Restriction Attenuates Intimal Hyperplasia and Alters Blood Lipid Profiles

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Christine R Mauro ◽  
Ming Tao ◽  
Peng Yu ◽  
Chengwei Liu ◽  
James Mitchell ◽  
...  
Keyword(s):  
Intimal Hyperplasia ◽  
Surgical Stress ◽  
Blood Lipid ◽  
Outer Diameter ◽  
Internal Elastic Lamina ◽  
Subsequent Removal ◽  
Short Term ◽  
Complete Diet ◽  
Protein Free Diet ◽  
Elastic Lamina

Introduction Dietary restriction (DR: reduced enteral intake without malnutrition) diminishes the acute phase response to surgical stress in preclinical models. We hypothesized that short-term preoperative protein-free DR would attenuate the vascular response to injury (intimal hyperplasia: IH) while perturbing systemic circulating lipids. Methods After 2 weeks of 60% fat kcal diet, 8 week old B6D2F1/J mice had ad lib access to a complete 10% fat kcal diet (n=10) or a reduced calorie, protein-free diet (DR group, n=10) 1 week before induction of IH, then an ad lib complete diet. IH was induced via a validated model placing a nylon suture tie around the distal carotid artery and external 35g needle mandrel (outer diameter=0.14mm). Subsequent removal of the mandrel created a focal area of stenosis (~78% lumen diameter/~85% flow reduction). 4 weeks later, tissues were harvested for morphology and immunohistochemistry for CD45. Separately, serum was collected from mice fed a complete or DR diet for 1 week absent any surgical stress (n=20/group) for mass spectrometry-based lipidomics. Results DR mice showed less intimal area (p = 0.032) vs controls with statistically equivalent intimal leukocyte infiltration. DR mice also had significantly larger internal elastic lamina length (p = 0.003), a remodeling measure. DR serum exhibited significant decreases in certain classes of circulating lipids, including a collapse of multiple triglyceride types. Conclusions One week of protein-free DR dramatically decreased circulating lipids and attenuated arterial IH. Preoperative dietary manipulations may offer a practical means of extending durability of vascular interventions.

Abstract 481: Disturbed Flow Arterial Intimal Hyperplasia Model in the Mouse Carotid Artery Induced by a Focal Stenosis

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Christine R Mauro ◽  
Ming Tao ◽  
Binh Nguyen ◽  
Peng Yu ◽  
C K Ozaki
Keyword(s):  
Carotid Artery ◽  
Intimal Hyperplasia ◽  
Outer Diameter ◽  
High Grade ◽  
Murine Models ◽  
Molecular Dissection ◽  
Disturbed Flow ◽  
Diet Induced Obesity ◽  
Normal Chow ◽  
Focal Stenosis

Objective: Murine models offer a power tool for the molecular dissection of remodeling and intimal hyperplasia mechanisms, though technical challenges limit their utility. While simple, complete carotid ligation lacks direct clinical relevance, and branch outflow ligations require advanced microsurgical skills. We thus developed a simple and clinically relevant mouse model based on the hypothesis that locally disturbed flow caused by a focal high grade stenosis would yield arterial intimal hyperplasia thickening, and that the standardized diet induced obesity (DIO) model would accentuate this response. Methods: A focal stenosis in 8 week old C57BL/6J mice (normal chow (NC, 10 kcal% fat) or DIO chow (60 kcal% fat) throughout study) was created by placing 9-0 nylon suture around the distal common carotid artery and an external 35-gauge needle (outer diameter=0.14mm), and then removing the needle to restore blood flow (∼78% reduction of lumen diameter; n=20). Tissues were perfusion fixed for morphology 4 weeks later. Results: Both NC and DIO groups developed intimal hyperplasia proximal to the stenosis, with approximately three-times more in the DIO animals (Figure 1). Conclusions: In the mouse, a surgically created focal stenosis yields an intimal hyperplastic wall response. DIO accentuates this response. This model offers a tool for investigating mechanisms of hemodynamically driven mechanisms governing intimal hyperplasia formation.

Structure of rattlesnake venom lectin determined by single particle high-resolution electron microscopy

1996 ◽  
Vol 54 ◽  
pp. 62-63
Author(s):  
Peter D. Moisiuk ◽  
Daniel R. Beniac ◽  
Ross A. Ridsdale ◽  
Martin Young ◽  
Bhushan Nagar ◽  
...  
Keyword(s):  
High Resolution Electron Microscopy ◽  
Lipid Monolayer ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
Single Particles ◽  
Crotalus Atrox ◽  
3D Reconstructions ◽  
X Ray ◽  
Rattlesnake Venom ◽  
Covalently Linked

Venom from the rattlesnake Crotalus atrox contains a mixture of enzymes that induce a localized effect leading to hemorrhaging, necrosis and edema. As a member of the crotalid family of snake venoms, Crotalus atrox venom contains a C-type lectin that will agglutinate blood cells in a Ca2+-dependent fashion. The lectin is a hydrophilic protein, consisting of two covalently linked, 135 amino acid residues, identical subunits that are rich in aspartic acid, glutamic acid and lysine. Sequence homology with known carbohydrate recognition domains (CRDs) indicates that rattlesnake venom lectin (RSLV) contains a CRD motif that is not linked to accessory domains. Preliminary X-ray diffraction and sedimentation analysis has indicated that lectin from Crotalus atrox forms decamers composed of two five-fold symmetric pentamers. Single particles of RSVL imaged at – 171°C displayed two distinct orientations on the specimen support (Figure a) following incubation in a crystallization Teflon well, coated with a lipid monolayer consisting of phosphatidylcholine and monosialoganglioside. When lying in an end-on orientation, the lectin exhibited a “pentagonal ring” with an outer diameter of 6.7 nm and an inner hollow core of 1.7 nm. A side orientation was also seen, whereby a thickness of 5.8 nm was measured for the lectin. Image processing of 2280 single particles placed in 100 classes (Figure b) led to 3D reconstructions of RSVL (Figure c). Density limited 3D reconstructions showed the lectin to be made of two five-fold symmetrical rings covalently linked between the five subunits that constitute each ring of this homodimer. These results are consistent with sedimentation and preliminary X-ray diffraction analysis on the shape of RSVL and provide the framework for structural verification by 2D electron crystallography.

TOXICITY OF SPHERICAL AND NEEDLE-SHAPED CALCIUM PHOSPHATE BIONS TO INJURED INTIMA OF THE RAT ABDOMINAL AORTA

2019 ◽  
pp. 80-88
Author(s):  
А.Г. Кутихин ◽  
Д.К. Шишкова ◽  
Е.А. Великанова ◽  
А.В. Миронов ◽  
Е.О. Кривкина ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Calcium Phosphate ◽  
Systemic Inflammation ◽  
Intravenous Administration ◽  
Intimal Hyperplasia ◽  
Mesenchymal Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cytotoxic Action ◽  
Alizarin Red ◽  
Synthetic Phenotype

Цель исследования - оценка токсического действия сферических кальций-фосфатных бионов и игольчатых кальций-фосфатных бионов на предварительно поврежденную интиму аорты крыс. Методика. Токсическое действие сферических кальций-фосфатных бионов и игольчатых кальций-фосфатных бионов на поврежденную интиму брюшной аорты крыс линии Wistar (n = 10 на группу) оценивали путем их однократного внутривенного введения после баллонной ангиопластики с эксплантацией поврежденного участка аорты через 5 нед. Биоптаты анализировали: 1) классическими гистологическими методами (окрашивание гематоксилин-эозином, ализариновым красным, по Вейгерту-ван Гизону и по Расселлу-Мовату); 2) иммунофлюоресцентным окрашиванием криосрезов (сочетанное окрашивание на CD31 и CD34, на CD31 и α-гладкомышечный актин (α-ГМА), на виментин и α-ГМА, на коллаген IV типа и α-ГМА). Для оценки влияния системного воспаления на КФБ-индуцированную эндотелиотоксичность определяли содержание моноцитарного хемоаттрактантного белка (МСР-1/CCL2) и церулоплазмина в сыворотке крови прооперированных крыс посредством иммуноферментного анализа. Результаты. Сферические кальций-фосфатные бионы и игольчатые кальций-фосфатные бионы вызывали выраженную гипертрофию интимы брюшной аорты в 90% (9 из 10 крыс) и 80% случаев (8 из 10 крыс) соответственно, в то время как частота гипертрофии в группе контрольных крыс составила лишь 10% (1 из 10 крыс). Неоинтима при экспозиции интимы брюшной аорты обоим типам бионов характеризовалась переходом фенотипа клеток мезенхимального ряда с контрактильного (α-ГМА-положительные и виментин-отрицательные гладкомышечные клетки) и неактивного (α-ГМА-отрицательные и виментин-положительные фибробласты) на активный синтетический (α-ГМА- и виментин-положительные клетки), что приводило к формированию значительных количеств экстрацеллюлярного матрикса. Внутривенное введение сферических кальций-фосфатных бионов и игольчатых кальций-фосфатных бионов не приводило к изменению уровней МСР-1/CCL2 и церулоплазмина в сыворотке крови, что свидетельствовало об отсутствии их возможного влияния на развитие системного воспалительного ответа. Заключение. Внутривенное введение кальций-фосфатных бионов после повреждения интимы брюшной аорты крыс путем баллонной ангиопластики вызывает развитие гипертрофии интимы, частота и выраженность которой не зависит от формы кальций-фосфатных бионов и которая характеризуется переходом фенотипа клеток мезенхимального ряда из контрактильного/неактивного на активный синтетический. При этом эндотелиотоксическое действие кальций-фосфатных бионов обусловлено их непосредственным воздействием на эндотелий, а не развитием системного воспаления. Purpose. To compare toxicity of spherical calcium phosphate bions (SCPB) and needle-shaped calcium phosphate bions (NCPB) to injured intima of rat aortas. Methods. Toxicity of SCPB and NCPB to injured abdominal aortas of Wistar rats (n = 10 per group) was evaluated using intravenous administration of the bions after balloon angioplasty. Rats were sacrificed five weeks postoperation, and an injured aortic segment was excised. Tissue preparations were stained with hematoxylin and eosin, alizarin red S, Weigert-van Gieson, and Movat’s pentachrome stains. Selected tissue samples were then examined using combined immunofluorescence staining (CD31/CD34, CD31/α-smooth muscle actin (α-SMA), α-SMA/vimentin, and α-SMA/collagen IV). Possible influence of systemic inflammation on CPB-induced endothelial toxicity was assessed by measuring monocyte chemoattractant protein-1 and ceruloplasmin in rat serum using the enzyme-linked immunosorbent assay. Results. Intravenous administration of SCPB or NCPB provoked intimal hyperplasia in 90% (9 of 10) and 80% (8 of 10) of rats vs. 10% (1 of 10) in the control group. The neointima was characterized by a phenotypic switch of mesenchymal cells, i.e. transition of a contractile (α-SMA-positive, vimentin-negative vascular smooth muscle cells) and quiescent (α-SMA-negative vimentin-positive fibroblasts) to an active synthetic phenotype (double-positive cells), which resulted in deposition of the extracellular matrix. Neither SCPB nor NCPB changed serum levels of pro-inflammatory molecules, МСР-1/CCL2, and ceruloplasmin. Conclusions. Intravenous administration of CPB upon balloon-induced vascular injury caused intimal hyperplasia regardless of the CPB shape. Hyperplasia foci were characterized by a switch of mesenchymal cells from a contractile/quiescent to an active synthetic phenotype. Endothelial toxicity of CPBs was defined by their direct cytotoxic action rather than induction of systemic inflammation.

Improvement Of Free Convection From Three horizontal Finned Cylinders Fixed Between Two Walls

2018 ◽  
Vol 6 (2) ◽  
pp. 98-114 ◽  
Author(s):  
Hassan K. Abdullah ◽  
Haneen H. Rahman
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Prandtl Number ◽  
Convection Heat Transfer ◽  
Constant Heat Flux ◽  
Heat Fluxes ◽  
Head Orientation ◽  
Outer Diameter ◽  
Gravitational Acceleration ◽  
Convection Heat

Improvement of  free convection heat transfer from three finned cylinders arranged at a triangle shape fixed between two walls has been investigated in this study. Three mild steel finned cylinders fixed between two walls from Pyrex glass have been used as a test rig. It has been changed the spacing between the cylinders (X/D=1,2,3 & S/D=2,4,6) and the head orientation of a triangle to the top under constant heat flux values (38, 254, 660, 1268) W/m2 and compare with case of three finned cylinders arranged in vertical array in line fixed between two wall. The experiments are carried for Rayleigh number (Ra) from (15x103 to 14 x104 ) and Prandtl  number from (0.706-0.714 ). The results indicated an increase in Nu with increasing Ra for all cylinders. Furthermore,hx and Nu increased proportionally with the increasing of cylinder spacings for all heat fluxes. Also the experimental results show the case of triangle arrangement is improvement the heat transfer more than case of vertical arrangement. Heat transfer dimensionless correlating equation is also proposed.              Nomeclature: Ax: surface area(m2), T∞: surrounding temperature(k), D: the outer diameter of fin (m), Kf: the thermal conductivity for air at film temperature(W/m.k), hx: Local convection heat transfer(W/m2.k),  Gravitational acceleration(m/s2), I: Electric current (Amp), Nu: Nusselt number, Pr: Prandtl number

Study of effect of deforming element acting surfaces angle on characteristics of power dynamics of combined hole mandrelling method

2020 ◽  
pp. 212-216
Author(s):  
A.V. Shchedrin ◽  
V.F. Aleshin ◽  
I.Yu. Ignatkin ◽  
N.Yu. Chikhacheva
Keyword(s):  
Power Dynamics ◽  
Outer Diameter ◽  
Force Dynamics ◽  
Steel 12Khn3a

The effect of the deforming element acting surfaces angle on the characteristics of the force dynamics of the combined deforming cutting mandrelling method of holes in the workpieces of various height and outer diameter from steel 12KhN3A is studied.

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