Influence of Angiotensin II on α1-Adrenergic Receptors Function in Rat Aorta and Expression in Vascular Smooth Muscle Cells

Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT1 and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α1-adrenergic receptors (α1-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10−5 M), and in some experiments, 5-Methylurapidil (α1A-AR antagonist), AH11110A (α1B-AR antagonist), or BMY-7378 (α1D-AR antagonist), were used to identify the α1-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α1D-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α1-ARs proteins were evaluated. α1D-AR increased at 30 and 60 min post Ang II exposure, the α1A-AR diminished from 1 to 4 h, while α1B-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α1D-AR at short times, and BMY-7378 protected α1D-AR from desensitization.

Endogenous Norepinephrine Desensitizes α1D-Adrenoceptors in Cultured Rat Aorta

Desensitization is a process characterized by the loss of cellular response to an agonist when this is present for a long time. α1D-adrenergic receptor (α1D-AR) desensitization is important since this receptor is involved in the contraction of large caliber arteries, such as the aorta. The aim of this research was to evaluate the desensitization of α1D-AR due to the endogenous release of norepinephrine in cultured rat aorta. Wistar rat aorta was incubated for 2 h or 24 h in DMEM at 37°C, and then subjected to isometric tension and the action of added norepinephrine, in concentration-response curve (CRC). In some experiments, BMY-7378 (α1D-AR antagonist) or 5-methylurapidil (α1A-AR antagonist) was used to identify the α1-AR involved in the response, or BMY-7378 to protect the α1D-AR from desensitization. Results showed that α1D-AR was desensitized when the aorta was incubated for 24 h, since the CRC to exogenous norepinephrine showed lower maximal contraction and the curve was displaced to the right, indicating that the receptor involved in contraction was not the α1D-AR, as compared to the aorta incubated 2 h. The receptor stimulated by norepinephrine at 24 h was neither the α1A-AR, as shown by the lack of displacement of the curve by 5-methylurapidil, but rather it seems that α1B-AR is inducing contraction. When the aorta was incubated with BMY-7378 for 24 h, the α1D-AR antagonist protected the receptor from desensitization. Endogenous norepinephrine desensitizes α1D-AR in the cultured aorta, and the α1D-AR is protected by BMY-7378.

Direct visualization of postoperative aortobronchial fistula on computed tomography

BACKGROUND Postoperative aortobronchial fistula(ABF)is a rare complication that can occur in 0.3%-5.0%of patients over an extended period of time after thoracic aortic surgery.Direct visualization of the fistula via imaging is rare.AIM To investigate the relationship between computed tomography(CT)findings and the clinical signs/symptoms of ABF after thoracic aortic surgery.METHODS Six patients(mean age 71 years,including 4 men and 2 women)with suspected ABF on CT(air around the graft)at our hospital were included in this retrospective study between January 2004 and September 2022.Chest CT findings included direct confirmation of ABF,peri-graft fluid,ring enhancement,dirty fat sign,atelectasis,pulmonary hemorrhage,and bronchodilation,and the clinical course were retrospectively reviewed.The proportion of each type of CT finding was calculated.RESULTS ABF detection after surgery was found to have a mean and median of 14 and 13 years,respectively.Initial signs and symptoms were asymptomatic in 4 patients,bloody sputum was found in 1 patient,and fever was present in 1 patient.The complications of ABF included graft infection in 2 patients and graft infection with hemoptysis in 2 patients.Of the 6 patients,3 survived,2 died,and 1 was lost to follow-up.The locations of the ABFs were as follows:1 in the ascending aorta;1 in the aortic arch;2 in the aortic arch leading to the descending aorta;and 2 in the descending aorta.ABFs were directly confirmed by CT in 4/6(67%)patients.Peri-graft dirty fat(4/6,67%)and peri-graft ring enhancement(3/6,50%)were associated with graft infection,endoleaks and pseudoaneurysms were associated with hemoptysis(2/6,33%).CONCLUSION Asymptomatic ABF after thoracic aortic surgery can be confirmed on chest CT.CT is useful for the diagnosis of ABF and its complications.

Expression of p-PPARγ in the aging thoracic aorta of spontaneously hypertensive rat and inhibitory effect of rosiglitazone

Objective:To investigate the expression of phosphorylated peroxisome proliferators-activated receptor y(p-PPARY) in the aging thoracic aorta of spontaneously hypertensive rat(SHR) and the inhibitory effect of rosiglitazone on the phosphorylation of PPART.Methods:16,32 and 64 week-old Wistar-Kyoto rats(WKY) and SHR were randomly and respectively divided into WKY,SHR and SHR+rosiglitazone group(9 in each group).The rats in SHR+rosiglitazone group were treated with rosiglitazone(5 mg/kg,intragastrically) for 56 d,whereas normal saline was applied in WKY and SHR groups.Systolic blood pressure(SBP)of rats was measured by tail cuff method.Histopathological damage of thoracic aorta was analyzed using Hematoxylin-Eosin(HE) staining.Immunohistochemical staining and western blot were performed to test the level of p-PPARY protein in the thoracic aorta arising from each group.Results:The SBP in 16,32 and 64 week-old SHR were significantly higher as compared with those in matched WKY rats(P【0.05,respectively).HE staining showed increased content of smooth muscle cell,wrinkled lining endothelium and increased thickness of internal elastic lamina in the thoracic aorta of SHR.Immunohistochemical staining and western blot indicated that the levels of p-PPARY in the thoracic aorta arising from SHR were obviously higher than those in the thoracic aorta arising from WKY rats(P【0.05,respectively).Importantly,the high SBP,histopathological abnormalities of the thoracic aorta and elevated p-PPARY expression were prominently abrogated by rosiglitazone treatment in SHR(P【0.05,respectively).Furthermore,the SBP,histopathological abnormalities of the thoracic aorta and p-PPARY expression were positively correlated with age in SHR(P【0.05,respectively).Conclusions:The PPARY phosphorylation was observed in the thoracic aorta of SHR and its expression was increased by the increase of age.Furthermore,rosiglitazone inhibited the PPARY phosphorylation and suppressed vascular aging in SHR.

The Effect of the LysoPC-induced Endothelial Cell Conditioned Medium on Proliferating Cell Nuclear Antigen Expression of the Calf Thoracic Aorta Smooth Muscle Cells

In order to study the effect of and mechanism of lysophosphatidylcholine (LysoPC) on proliferation of the calf thoracic aorta smooth muscle cells (ASMCs), the ASMCs were used to observe the effects of LysoPC induced endothelial cell conditioned medium on the DNA content and proliferating cell nuclear antigen (PCNA) expression in the calf thoracic ASMCs by flow cytometry and Western Blot technique. It was found that LysoPC induced endothelial cell conditioned medium could significantly promote PCNA expression of the calf ASMCs, induce the converting of ASMCs from G 0 /G 1 phase to S phase of DNA synthesis, and increase the tyrosine phosphorylation protein expression. Tyrosine protein kinase inhibitor (TPKi) RG50864 could obviously inhibit proliferation of LysoPC induced ASMCs in a dose dependence manner. The results indicated that the effect of LysoPC promoting the proliferation of ASMCs is partly evoked by endothelial cell derived growth factors such as PDGF and so on.

Effect of bFGF on expression of MMPs mRNA on the rat thoracic aorta after ballon injury and cultured VSMCS

Background:Extracellular matrix (ECM) plays a very important role in the development ofrestenosis after PTCA The MMPs,enymes specialized in degradation of ECM,probably partciptesin extracelular matrix remodeling after balloon injury,but the factors that regulates MMPs activity arenot completely understood Basic fibroblast growth factor (bFGF),as a mitogen for a variety of cellstypes,influences metabolism of ECM.However,if effects on MMPs are not known.Methodsand Results:24 male Wistar rats were divided randomly into control group,balloon-injuried group andbFGF-treated group.The rats of control group were not treated.The rats in balloon-injuried group weredamaged by balloon and the thoracic aortas were harvested after two weeks.In the bFGF-treated grorp,balloon injury and the injuried vessels were collected after two weeks.The northern blot was used toinvestigate the MMP1,MMP2 and MMP9 mRNA expression of vesss.At the same time,the effectsof differet dose bFGF (0ng/ml,40ng/ml,80ng/ml and 120ng/ml) on the MMPs expression of culturedVSMCs were examined The results showed the bFGF can selectively increase the expression ofMMP1 and MMP9 mRNA without effect on the MMP2 on the injuried rat thoracic aorta,and dosedependently increase the MMP1 mRNA expression of cultured VSMCs without MMP2 and MMP9expression Conclusion:bFGF selectively increased MMPs mRNA expression on both injuried ratthoracic aorta and cultured VSMCs.This effect may be related to the degradation of ECM,remodelingof vessel after injuty.

Clonidine Inhibits Phenylephrine-Induced Contraction of Rat Thoracic Aortae by Competitive Antagonism of α₁-Adrenoceptors Independent of α₂-Adrenoceptor Stimulation

Clonidine is a classically categorized α2-adrenoceptor (α2-AR) agonist that produces vascular contractions by stimulating arterial smooth muscle α2-ARs. However, clonidine inhibits α1-AR-mediated arterial contractions. Recently, it was suggested that repeated stimulation with clonidine induces desensitization of α2-ARs, thus inhibiting noradrenaline-induced smooth muscle contractions. In the present study, we examined whether clonidine-mediated inhibition of α1-AR contractions involves interactions with α2-ARs in rat thoracic aortae. 1) Clonidine and guanfacine inhibited electrical field stimulation-induced contractions in a concentration-dependent, yohimbine-sensitive manner in isolated rat vas deferens preparations. 2) Clonidine almost completely suppressed phenylephrine-induced sustained contractions of rat thoracic aortae. 3) Clonidine competitively inhibited phenylephrine-induced contractions with a pA2 value of 6.77 at concentrations between 10-7 and 10-6 M. At 10-5 M, clonidine inhibited phenylephrine-induced contractions and dramatically reduced maximum contractions. 4) In contrast, clonidine did not inhibit contractions produced by high KCl or prostaglandin F2α. 5) Inhibition of phenylephrine-induced sustained contractions by clonidine was also produced in the presence of yohimbine. However, guanfacine did not inhibit phenylephrine-induced sustained contractions. These findings suggest that clonidine inhibits phenylephrine-induced contraction of rat thoracic aortae by competitive antagonism of α1-ARs, which is mediated through a mechanism independent of α2-AR stimulation.

The life-saving emergency thoracic endovascular aorta repair management on suspected aortoesophageal foreign body injury

BACKGROUND:Fatal aortic rupture caused by esophageal foreign body(EFB),is associated with a high mortality,but can be prevented by thoracic endovascular aorta repair(TEVAR)that performed increasingly as technology improves.This study aims to investigate the cause,management and prognosis of suspected penetrating aortoesophageal foreign body injury.METHODS:Twelve cases who met the criteria were enrolled in this study.The demographic and clinical data were reviewed for evaluating the characteristics of EFB.RESULTS:Among 12 cases enrolled,7 were males and 5 were females,with an age 27–86 years.The distance of EFB from aorta(DFA)of 7 cases were less than or equal to 0 mm,5 cases were 0–2 mm.Eleven cases were managed with TEVAR,only one case was with open surgery standby but finally treated by flexible endoscopy(FE)successfully,without TEVAR.In group with TEVAR,EFB of 7 cases were successfully removed by rigid endoscopy(RE),and one of them was failed at the first RE treatment.EFB of 2 cases were successfully removed by open surgery with TEVAR,and other 9 cases were managed by endoscopies with TEVAR.The mean length of stay of hospitalization(LOS)and length of ICU stay of patients treated by open surgery with TEVAR(18.50±2.12 days and 5.50±0.71 days)was significantly longer than those of patients treated by endoscopy with TEVAR(7.00±2.74 days and 1.33±1.12 days,P<0.001 and P=0.001,respectively).Five cases had severe complications.CONCLUSION:Rational application of TEVAR can be a life-saving management for aortoesophageal foreign body injury,and jointed with endoscopy is safe and effective with a shorter length of ICU or total hospital stay.

Correlation between thoracic aorta 18F-natrium fluoride uptake and cardiovascular risk

AIM: To investigating the relationship between thoracic and cardiac 18F-Natrium-Fluoride (18F-NaF) uptake, as a marker of ongoing calcification and cardiovascular risk factors.METHODS: Seventy-eight patients (44 females, mean age 63, range 44-83) underwent whole body 18F-NaF positron emission tomography/computed tomography. Cardiovascular risk (CVR) was used to divide these patients in three categories: Low (LR), medium (MR) and high risk (HR). 18F-NaF uptake was measured by manually drawing volumes of interest on the ascending aorta, on the aortic arch, on the descending aorta and on the myocardium; average standardized uptake value was normalized for blood-pool, to obtain target-to-background ratio (TBR). Values from the three aortic segments were then averaged to obtain an index of the whole thoracic aorta.RESULTS: A significant difference in whole thoracic aorta TBR was detected between HR and LR (1.84 ± 0.76 vs 1.07 ± 0.3, P < 0.001), but also between MR and HR-LR (1.4 ± 0.4, P < 0.02 and P < 0.01, respectively). Significance of this TBR stratification strongly varied among thoracic aorta subsegments and the lowest P values were reached in the descending aorta (P < 0.01). Myocardial uptake provided an effective CVR classes stratification (P < 0.001).Correlation between TBR and CVR was appreciable when the whole thoracic aorta was considered (R = 0.67), but it peaked when correlating the descending thoracic segment (R = 0.75), in comparison with the aortic arch and the ascending segment (R = 0.55 and 0.53, respectively).CONCLUSION: Fluoride uptake within the thoracic aorta wall effectively depicts patients’ risk class and correlates with cardiovascular risk. Descending aorta is the most effective in CVR determination.

Acute Type A Aortic Dissection—Replacement of Ascending Aorta, Aortic Arch and Antegrade Stenting of the Descending Thoracic Aorta Using the Thoraflex™Hybrid Plexus Device (Terumo Aortic)—“Frozen Elephant Trunk”: The Plymouth Way!

Objectives: To describe our technique for the implantation of the Thoraflex Hybrid prosthesis for replacement of the aortic arch in a safe and reproducible way. Materials: Thoraflex™ Hybrid Plexus Device (Terumo Aortic). Design: Drawing on our own experience over the past 4 years in the management of acute type A aortic dissection, we have distilled the essentials of our “Frozen Elephant Trunk” technique which have led us through our own learning curve to the improved management of this taxing condition. Method/ Results: Small extension of the median sternotomy incision along the medial border of sternocleidomastoid muscle. End to side graft anastomosis near the origin of the left subclavian artery during cooling on bypass towards 20 degrees. Attention to cardiac protection and maintenance of cerebral perfusion during the shortened corporeal arrest period. Excellent results in 24 consecutive AAAD patients with just one hospital mortality. Conclusions: We believe we are entering a new phase in the treatment of AAAD, facilitated by the availability of a hybrid prosthesis which combines expanding stent technology with familiar surgical graft material. Our particular management of the left subclavian artery and of the cerebral circulation during implantation has contributed to an expeditious and reproducible method of treating dissection within the arch of the aorta and beyond.

A SD rat model of thoracic aortic aneurysms

Backgroud Thoracic aortic aneurysm (TAA) disease is a serious condition with both high mortality and morbidity rates associated with surgical therapy. Further understanding of the formation and progression of TAAs may provide novel, less invasive therapeutic strategies in patients with this devastating disease. Aneurysm formation is a complicated, dynamic process involving both cellular and extracellular processes. The mechanisms of TAA formation are poorly understood, mainly due to the lack of a useful and reproducible model. In 2003, Ikonomidis in South Carolina developed a murine model of TAA.The mouse model was less satisfactory because the small size of the murine aorta. The rat model has the advantage of larger aorta and the ability to do more research. Proper animal models are useful to understand the aetiology and evolution and they can be used to evaluate the efficacy of new treatments.Objective The goal of this study was to test the hypothesis that abluminal calcium chloride application could creat TAAs in the SD rats.MethOds Eight-week-old male Sprague-Dawley(SD) rats(n=60) were divided into two groups equally. All rats were anesthetized. An angiocath was then advanced through the mouth into the trachea under direct vision and connected to a rodent ventilator set at a respiratory rate of 180 breaths per minute. And their thoracic aortas were exposed via left thoracotomy. In the experiment group,a sponge soaked in 0.5 mol/L CaCl2 was placed on the distal half of the exposed descending thoracic aorta under direct vision. As control group, 0.5 mol/L CaCl2 was instead of 0.9% NaCl. After 15 min, the sponge was removed. Then the chest was closed. At 4,8,12 weeks, all animals undergoing fixation and aortic harvest were reanesthetized and the thorax was then opened beneath the xiphoid process. Potassium chloride was injected into the left ventricle under direct vision to arrest the heart. Then it was perfusion program and the entire animal was immersed in formalin. Seven days after fixation, the animal was removed from formalin, and the aorta was carefully harvested from its root to the renal arteries. The aorta was then immersed in an individually labeled jar containing a mixture of 80% methanol and 20% dimethyl sulfoxide (Dent’s solution).Diameter measurements were made using Axioplan 2 imaging system. Hematoxylin and eosin staining and Van Gieson and Verhoeff staining showed the elastic architecture and collagen structure. Immunohistochemical staining was performed to evaluate the presence of lymphocytes and macrophages. Results 12 weeks of CaCl2 treatment resulted in visually obvious dilation of the exposed distal descending thoracic aortic segment.The distal descending thoracic aortic diameter at 4,8,12 weeks was (0.82±0.13), (1.12±0.43), (1.65±0.58)μm respectively. The control group at 4,8,12 weeks was (0.81±0.04) , (0.94±0.12), (1.09±0.03)μm respectively. The diameter of the ascending aorta (used as an internal control) were not significantly different between groups. Hematoxylin and eosin stained slides showed disruption of the normal elastic lamellar architecture of the CaCl2-exposed aortic wall compared to the contralateral wall or untreated control. Van Gieson-stained sections showed decreased collagen content in the exposed region of aortic wall. Immunohistochemical study indicated significantly more CD3+cells and CD68+ cells in the aortas of CaCl2 treated groups than in control aortas. CD3+ cells were located in the media and surrounding the vasa vasorum in the adventitia. Conclusion We conclude that abluminal application of CaCl2 to the thoracic aorta reliably produces dilation, wall-thinning, and disruption of mural architecture, the hallmark signs of aneurysm formation. These results suggest that the rat is a useful and technically feasible model for the study of TAAs. To our knowledge, these findings describe for the first time the generation of a reproducible model of isolated TAA formation in SD rat.

Comparative study of the mechanical behavior of the superior thoracic artery and abdominal arteries using the finite elements method

The human body has been the subject of thorough researches—not only from medical perspective but from a technical one as well—are very rich, amongst them we find blood circulation system comprising: the heart, the arteries and the veins. The overriding role of these researches is to explain some cardiovascular pathology and provide an aid tool for the endoprothesis positioning in blood vessels while treating them. In this study we have developed a digital pattern using the common (engineering technique of the) finite element method (FEM) to simulate the mechanical behavior of the thoracic aorta and the abdominal aorta below the kidney under blood pressure effect. This pattern calculates the displacements, the stresses (constraints) and the deformations of the two arteries’ walls enabling us to know their experimentally determined mechanical and geometric properties. This pattern could be applied to detect the aneurysm and dissection phenomena.

Effect of swirling flow on LDL and ox-LDL uptake in rabbit thoracic aorta

Object To elucidate the physiological significance of the spiral flow in the arterial system from the viewpoint of atherogenic lipid transport,an ex vivo experimental comparative

天麻素可能通过抑制自噬信号改善大鼠肾性高血压

目的 探讨天麻素改善大鼠肾性高血压作用机制。方法 75只SD雄性大鼠随机分为5组(n=15):假手术组、肾性高血压模型组、模型+雷米普利(1 mg·kg^(-1))组和模型+天麻素(100和200 mg·kg^(-1))组。通过结扎肾动脉构建肾性高血压大鼠模型,以尾动脉收缩压>18.12 kPa为造模成功。造模成功后,给药组大鼠分别ig给予相应剂量的雷米普利或天麻素,连续4周。采用比色法检测大鼠血清超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量,采用ELISA检测血清血管紧张素2(Ang-2)和醛固酮(ALD)含量及血清和胸主动脉组织白细胞介素1β(IL-1β)、IL-6和肿瘤坏死因子α(TNF-α)含量,HE染色观察大鼠主动脉病理结构的改变。Western印迹法检测大鼠主动脉组织自噬蛋白微管相关蛋白轻链3Ⅱ(LC3-Ⅱ)与LC3-Ⅰ的比值(LC3-Ⅱ/LC3-Ⅰ)。结果 与假手术组比较,模型组大鼠血清Ang-2含量显著升高(P<0.01),ALD显著降低(P<0.01);血清和主动脉组织SOD活性显著降低(P<0.01),MDA含量显著升高(P<0.01),IL-1β,IL-6和TNF-α含量均显著升高(P<0.01);胸主动脉壁增厚且炎症细胞浸润,自噬蛋白LC3-Ⅱ/LC3-Ⅰ比值显著升高(P<0.01)。与模型组比较,模型+天麻素(100和200 mg·kg^(-1))组大鼠尾动脉收缩压显著降低(P<0.01);血清Ang-2含量显著降低(P<0.01),ALD含量升高(P<0.01),血清SOD活性增加(P<0.01);血清和主动脉组织MDA,IL-1β,IL-6和TNF-α含量降低(P<0.01);大鼠主动脉组织病理改变改善,同时LC3-Ⅱ/LC3-Ⅰ降低(P<0.01)。结论 天麻素可改善肾性高血压模型大鼠血压,其机制可能与降低LC3-Ⅱ/LC3-Ⅰ比值有关。

CT胸椎骨定量与冠脉及胸主动脉钙化相关研究

目的探讨常规CT中胸椎椎体骨质定量与冠脉及胸主动脉钙化相关性。方法收集217例患者一般资料、生化指标及冠脉CTA。测量冠脉、胸主动脉钙化积分,分为钙化组与非钙化组。测量T6~11椎体松质骨及皮质骨密度,椎体骨赘积分。进行组间比较、相关分析及回归分析。结果冠脉与胸主动脉钙化组年龄、收缩压、血糖及骨赘积分均高于非钙化组,松质骨密度低于非钙化组(P<0.05)。冠脉钙化积分与年龄、收缩压、血糖、皮质骨密度及骨赘积分正相关,与松质骨密度负相关(P<0.05)。胸主动脉钙化积分与年龄、收缩压及骨赘积分正相关,与松质骨密度负相关(P<0.05)。回归分析示年龄、收缩压、血糖及骨赘积分是冠脉钙化的独立风险因素,年龄、收缩压及骨赘积分是胸主动脉钙化的独立风险因素(P<0.05)。ROC曲线示联合应用各独立风险因素能提高对冠脉及胸主动脉钙化风险的预测价值。结论椎体骨赘积分增高和松质骨密度减低与冠脉及胸主动脉钙化显著相关。

SIRT1激动剂促进老化内皮细胞增殖和成血管能力

目的探讨沉默信息调节因子2相关酶1(silent mating type information regulation 2 homolog-1,SIRT1)抑制剂EX-527与激动剂SRT1720对老化内皮细胞成血管能力的影响。方法采用体外培养大鼠原代主动脉内皮细胞衰老技术,通过培养细胞的自然倍增建立大鼠主动脉内皮细胞(rat aorta endothelial cell,RAEC)衰老的细胞模型。内皮细胞的衰老用SA-β-Gal染色进行鉴定。衰老细胞模型建立后,对衰老的RAEC分别给予SIRT1抑制剂EX527和SIRT1激动剂SRT1720干预。运用Ki-67免疫荧光染色检测内皮细胞增殖,采用基质胶内皮管形成实验检测内皮细胞内皮管形成,应用蛋白印迹技术检测内皮细胞eNOS表达。结果SIRT1激动剂抑制老化RAEC增殖能力、内皮管形成能力和eNOS表达的降低,而SIRT1抑制剂使老化RAEC的增殖能力、内皮管形成能力和eNOS表达降低。结论SIRT1促进RAEC的增殖和内皮管形成,并增强RAEC中eNOS的表达;SIRT1改善衰老内皮细胞受损的成血管能力可能与其抑制衰老RAEC eNOS表达的下调有关。

益气养阴方对动脉粥样硬化大鼠免疫炎症因子和胸主动脉内、中膜厚度的影响

目的:观察益气养阴方对动脉粥样硬化大鼠治疗前后免疫炎症因子的表达水平及对胸主动脉内、中膜厚度变化的影响。方法:46只4周龄SPF级Wistar雄性大鼠,随机选出10只为空白组,只给予基础饲料,其余36只采用主动脉内膜球囊拉伤术加高脂饲料喂养完成动脉粥样硬化大鼠模型。造模成功后的30只随机分为模型组、益气养阴方组(中药组)和瑞舒伐他汀组(西药组),每组10只。空白组予以基础饲料喂养,中药组给予益气养阴方,西药组给予瑞舒伐他汀钙片。给药6周后胸主动脉剪取粥样斑块留作标本,检测超敏C反应蛋白(hypersensitive C-reactive protein,hs-CRP)、转化生长因子β_(1)(transforming growth factor β_(1),TGF-β_(1))、白细胞介素8(interleukin-8,IL-8)、基质金属蛋白酶9(matrix metalloproteinase-9,MMP-9)的表达水平及胸主动脉内、中膜厚度及病理变化。结果:用SNK法两两比较,与模型组比较,中药组、西药组在hs-CRP、TGF-β_(1)、IL-8、MMP-9的表达水平方面均明显降低(P<0.05),胸主动脉内、中膜厚度的变化差异有统计学差异(P<0.05)。益气养阴方组大鼠胸、腹主动脉各层细胞结构的组织修复方面优于模型组,病变明显减轻。结论:益气养阴方对动脉粥样硬化大鼠治疗前后hs-CRP、TGF-β_(1)、IL-8、MMP-9的表达水平及颈动脉内中膜厚度方面均有明显改善作用,为临床对动脉粥样硬化的干预治疗提供一个研究方向。

红细胞分布宽度对不同透析方式患者胸主动脉钙化的预测价值

目的分析维持性透析患者胸主动脉钙化(thoracic aortic calcification,TAC)的危险因素,探讨红细胞分布宽度(red cell distribution width,RDW)在血液透析和腹膜透析患者中对TAC的预测价值。方法共收集190例于2022年1月至2022年6月在昆明医科大学第二附属医院长期维持性透析患者的资料,根据胸部X线检查结果是否合并TAC分为钙化组(n=48)和非钙化组(n=142)进行组间比较,采用二元Logistic回归分析患者发生TAC的危险因素,并应用ROC曲线分析RDW对不同透析方式患者发生TAC的预测价值。结果本组TAC发生率为25.3%。钙化组RDW比非钙化组高(P<0.01),多因素二元Logistic回归分析显示RDW[OR=1.541,95%CI(1.145,2.074),P=0.004]、年龄[OR=1.041,95%CI(1.008,1.075),P=0.014]、透析龄[OR=1.016,95%CI(1.002,1.031),P=0.025]、血磷[OR=2.172,95%CI(1.109,4.253),P=0.024]是透析患者发生TAC的独立危险因素。RDW预测血液透析患者TAC发生的ROC曲线下面积(AUC=0.719)比腹膜透析患者曲线下面积(AUC=0.661)更大。结论RDW是透析患者发生TAC的独立危险因素,RDW对血液透析患者发生TAC的预测价值比腹膜透析更好。

Stanford B型主动脉夹层行TEVAR干预时机分析

目的探索胸主动脉腔内修复术(thoracic endovascular aortic repair,TEVAR)不同干预时机治疗Stanford B型主动脉夹层后的疗效。方法回顾性分析2018年1月至2023年4月于我院就诊的126例Stanford B型主动脉夹层患者,根据发病时间至手术时间分为A组(<24 h)、B组(2~7 d)和C组(8~14 d)。比较三组围手术期不良事件(内漏、脑梗死、死亡、主动脉破裂及总并发症等)发生情况,并根据随访情况进行生存分析。结果本研究共计纳入126例Stanford B型主动脉夹层患者,其中A组50例,B组43例,C组33例。三组在一般情况方面无统计学差异(P>0.05);三组在围手术期急性脑梗死、内漏、感染及死亡发生率方面无统计学差异(P>0.05),在总并发症发生率方面存在统计学差异(P<0.05);应用Log-rank检验比较三组生存曲线,A组5年累计无主动脉夹层复发及生存率低于B组、C组,差异有统计学意义(P<0.05)。结论本研究认为在症状出现后24 h内行TEVAR治疗B型主动脉夹层不良事件发生率及近中期疗效不佳,而在症状出现2~14 d行TEVAR可获得较好的围手术期及近中期结果。

主动脉弓部手术围手术期的脑保护

体外循环和停循环下维持最佳脑灌注是主动脉弓部手术中脑保护的基础。脑保护策略包括低温、脑灌注、药物治疗和血气管理,已应用于临床,但最佳策略仍难确定。主动脉弓部手术中脑保护的临床结局在很大程度上取决于脑温、停循环时间和脑灌注类型,最佳的脑保护策略应是在全面脑监测的基础上进行个体化治疗,有效减少脑损伤。本文总结体外循环下主动脉弓部手术脑监测与管理方法或指标以及围手术期脑保护策略,以指导主动脉弓部手术中脑保护的临床实践。