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.

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.

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

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.

Vasorelaxation Effect of Gastrodin on Isolated Thoracic Aorta Rings of Rats

Objective： To study the effect of gastrodin on isolated thoracic aorta rings of rats and to investigate the potential mechanism. Methods： A perfusion model of isolated thoracic aorta rings of rats was applied. The effect of cumulative gastrodin （5, 50, 100,150, 200, and 250 μ mol/L） on endothelium-intact aorta rings was investigated. The same procedure was applied to observe the effect of gastrodin on endotheliumintact/denuded aorta rings pre-contracted with 10.8 mol/L phenylephrine hydrochloride （PE）. The aorta rings incubated by 200 mmol/L gastrodin in the Ca2＋-free （K-H） solution was contracted by using PE. The effect of 200 mmol/L gastrodin on endothelium-denuded aorta rings pre-contracted with 60 mmol/L KCI was also observed. Results： Compared with the denuded gastrodin group, the intact gastrodin group could significantly relax the PE-contracted aorta rings （P〈0.01）. In Ca2＋-free （K-H） solution KHS, the PE-induced contraction rate of aorta rings pre-incubated by gastrodin was 6.5%± 0.7%, which was significantly less than the control group （11.8% ± 0.9%, P〈0.01）. However, after 3 mmol/L CaCl2 was added, the Ca2＋-induced contraction in the gastrodin group （51.7% ±2.4%） was similar to that in the control group （49.8% ± 2.8%）. The contractile rate of rings in the KCI-contracted gastrodin group （96.3%± 0.6%） was not significantly different from that in the control group （96.8± 1.2%）. Conclusions： Gastrodin has the effect of vasorelaxation on isolated thoracic aorta rings of rats. The mechanism of the vasorelaxation of gastrodin may mainly work through the inhibition of inositol 1,4, 5-trisphosphosphate receptor on the sarcoplasmic reticulum of the arterial smooth muscle, which leads to the reduction of the Ca2. released from the sarcoplasmic reticulum.

Endovascular repair of a tuberculous aneurysm of descending thoracic aorta

Tuberculous aortic aneurysm （TBAA） is an extremely rare clinical event with life-threatening implication. Management for this condition is challenging and its therapeutic option has not been yet established. A few recent reports described endovascular repair rather than open surgery as the method for treatment. Although this remains controversial,endovascular exclusion has been gaining acceptance for some surgeons. We present a case of TBAA who was treated by endovascular stent grafting for a descending thoracic aortic aneurysm with simultaneous anti-tuberculous medication.The outcome was favorable.

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.

Secondary aortoesophageal fistula initially presented with empyema after thoracic aortic stent grafting:A case report

BACKGROUND Massive upper gastrointestinal(GI)bleeding is usually urgent and severe,and is mostly caused by GI diseases.Aortoesophageal fistula(AEF)after thoracic aortic stent grafting is a rare cause of this condition,and has a poor prognosis with a high mortality rate.The clinical symptoms of AEF are usually nonspecific,and the diagnosis is often difficult,especially when upper GI bleeding is absent.Early identification,early diagnosis,and early treatment are very important for improving prognosis.CASE SUMMARY A 74-year-old man was admitted to the infectious disease department with>10-d fever and 10-mo prior history of thoracic aortic stent grafting for thoracic aortic penetrating ulcers.Blood tests revealed elevated inflammatory indicators and anemia.Chest computed tomography(CT)showed postoperative changes of the aorta after endovascular stent graft implantation,pulmonary infection and pleural effusion.Pleural effusion tests showed empyema.After 1 wk of anti-infective treatment,temperature returned to normal and chest CT indicated improvement in pulmonary infection and reduction of pleural effusion.Esophageal endoscopy was performed because of epigastric discomfort,and showed a large ulcer with blood clot in the middle esophagus.However,on day 11,hematemesis and melena developed suddenly.Bleeding stopped temporarily after hemostatic treatment and bedside endoscopic hemostasis.Thoracic and abdominal aortic CT angiography confirmed AEF.Later that day,he suffered massive hemorrhage and hemorrhagic shock.Eventually,his family elected to discontinue treatment.CONCLUSION AEF should be strongly considered in patients with a history of aortic intervention who present with fever,especially with empyema.

Current knowledge and contemporary management of non-A non-B aortic dissections

Non-A non-B aortic dissection(AAD)is an infrequently documented condition,comprising of only a small proportion of all AADs.The unique anatomy of the aortic arch and the failure of the existing classifications to adequately define individuals with non-A non-B AAD,have led to an ongoing controversy around the topic.It seems that the clinical progression of acute non-A non-B AAD diverges from the typical type A and B dissections,frequently leading to serious complications and thus mandating early intervention.Currently,the available treatment methods in the surgical armamentarium are conventional open,endovascular techniques and combined hybrid methods.The optimum approach is tailored in every individual case and may be determined by the dissection’s location,extent,the aortic diameter,the associated complications and the patient’s status.The management of non-A non-B dissections still remains challenging and a unanimous consensus defining the gold standard treatment has yet to be reached.In an attempt to provide further insight into this perplexing entity,we performed a minireview of the literature,aiming to elucidate the epidemiology,clinical course and the optimal treatment modality.

Use of three dimensional-printing in the management of floating aortic thrombus due to occult aortic dissection:A case report

BACKGROUND Floating thrombus within the thoracic aorta is a rare entity but may cause systemic embolism.The pathogenesis of floating aortic thrombi is not yet fully understood.No definitive guidelines are available for the management of floating aortic thrombus.CASE SUMMARY We report a 48-year-old patient,without a history of trauma and infection,who presented with sudden severe back pain.A floating thrombus within the aortic arch was found by computed tomography angiography(CTA).No evidence of coagulopathies was found.However,with the assistance of a three dimensionalprinted model,this floating thrombus was identified to be caused by occult aortic dissection(AD).Subsequently,an emergency thoracic endovascular repair was performed.The patient’s back pain was rapidly alleviated postoperatively.CTA at 1 year showed no filling defect in the stent-graft and aorta.CONCLUSION Occult AD is a potential factor causing floating aortic thrombi,endovascular stent-graft exclusion may be an optimal therapeutic choice with promising results.Moreover,the combination of CTA and three dimensional-printed models can contribute to the diagnosis and treatment of floating aortic thrombi due to occult AD.

PROTECTIVE EFFECTS OF CALCIUM ANTAGONIST ON VASCULAR SYSTEM AGAINST TOXICITY INDUCED BY MERCURIC CHLORIDE

Objective To explore the toxic effects of mercuric chloride (HgCl 2) on vascular smooth muscle as well as its relationship to calcium antagonist. Methods By using isolated vascular tension methods, we studied the effect of HgCl 2 on isolated rabbit aortic rings. Results HgCl 2 (1-100 μmol·L -1) caused a concentration-dependent contraction of rabbit aortic rings, which did not change with phentolamin or without endothelium. In KH solution with Ca 2+ , the maximum contraction amplitude reduced by(61.2±3.3)%. Nifedipine produced a concentration-dependent decrease of the maximum contraction amplitude. Conclusion Calcium antagonist has protective effects on vascular smooth muscle against damage induced by HgCl 2.

Effects of Total Alkaloids in Buxus microphylla Leaves on Aorta Smooth Muscle of Rats and Their Mechanisms

Objective To investigate the effects of total alkaloids in Buxus microphylla leaves(ABML)on isolated rats thoracic aorta rings,and then to explore the possible mechanisms underlying the effects.Methods Thoracic aortas of Wistar rats were isolated,removed,and mounted onto an organ bath.The effects of ABML at different concentration on the contraction of isolated thoracic aorta rings(with and without endothelium)precontracted with KCl or PE were observed with organ bath technique.Dose-effect curves of CaCl2 were recorded by organ bath technique.The concentration of intracellular Ca 2+ ([Ca 2+ ]i)increased by PE,KCI,and caffeine in the presence of ABML was determined using Ca 2+ sensitive fluorescence indicator Fura-2/AM loaded thoracic aorta vascular smooth muscle (VSM)cells of rats.Results In aorta rings precontracted with PE and KCl,ABML produced concentration- dependent relaxation in both intact and denuded endothelium ring groups.There was no difference in the inhibition of contraction between the intact and denuded endothelium ring groups at the same concentration.Exposure of isolated thoracic aorta rings to ABML led to a significant reduction in the contracting response induced by CaCl2,and shifted the cumulative concentration-response curves to right.ABML could significantly inhibit the extracellular Ca 2+ influx induced by PE and KCl under[Ca 2+ ]0 of 1.5 mmol/L,with inhibitory ratios of 40.2%and 49.9%,respectively.In the case of Ca 2+ -free,ABML could significantly inhibit the intracellular Ca 2+ release induced by PE,with inhibitory ratio of 72.4%.Conclusion ABML relaxes thoracic aorta VSM cells by suppressing influx of extracellular Ca 2+ via voltage-dependent Ca 2+ channel and receptor-operated Ca 2+ channel.

Endovascular repair of traumatic thoracic aortic injury:10-year single-center experience

Background Traumatic thoracic aortic injury （TAI） is an uncommon but fatal injury. The purpose of this study was to present our experience and results of thoracic endovascular aortic repair （TEVAR） in patients with TAI in single center. Methods From February 2007 to March 2016, the medical records of 21 patients with TAI admitted to our institution were retrospectively reviewed. Among these patients, 20 patients were treated with TE- VAR and 1 was excluded for posterolateral thoracotomy. The demographics, injury characteristics, procedural de- tails, and clinical outcomes of these patients were evaluated. Results In the 20 patients with TEVAR, 14 pa- tients were man （70.0%） and the mean age was 34.3_＋10.8 years （range, 14-55 years）. The causes of injury were motor vehicle accident （18/20, 90.0%） and fall from height （ 2/20, 10.0%）. All patients had concomitant injuries and a mean ISS was 36.0 ± 15.0 （20-75）. All patients received TEVAR with the aortic injuries located at aortic isthmus （11/20, 55.0%） and the remaining at descending aorta. Nine patients received intentional coverage of LSA during TEVAR. Of which, 6 cases were partial coverage. The primary technical success of TEVAR was 100% and a single stent graft was sufficed for the TAI repair in all cases. The average cover length was 152.3± 20.0 mm （range, 100-200 mm）. No patient died or had serious postoperative complications in hospital. The rate of absorption period of aortic injuries after TEVAR for ≤3 months, 3-6 months, and ≥6 months was 65.0%, 30.0%, and 5.0% respectively. There was no late explanation or device failures identified although 2 patients were detected poor apposition in the 12 months after TEVAR. Conclusions TEVAR can be performed safely with a relatively low mortality and morbidity and should be the preferred treatment for patients with TAI. But the durability of endograft needs long follow-up.

Emergent treatment of patients with traumatic aorta ruptures

Objective ： To discuss our experience on the diagnosis and treatment of thoracic aorta rupture （TAR） that is one of the main common causes of death in the victims under blunt chest trauma. Methods： Between July 2001 and March 2006, 9 patients （6 men and 3 women, aged from 20 to 54 years ） suffering from acute traumatic aorta rupture after motor vehicle accidents received emergent surgical treatments in our hospital. Based on our experience in the rescue of the first TAR patient we introduced a practical procedure on the diagnosis and treatment of TAR in our department. All the other patients generally followed this procedure. Eight patients received contrast material enhanced helical computerized tomography scan before the operation. The leakage of coustrast medium from the aorta isthmus was found, and diagnosis of TAR was confirmed. Seven patients underwent immediate operation within 14 hours after accidents. One patient was treated on the 5th day of the accident because of delayed diagnosis of aortic rupture. All patients received general anesthesia with double lumen endotracheal tube and normothermic femoro-femoral partial cardiopulmonary bypass, with beating heart and aortic clamping. One patient received simple repair, and others received partial replacement of thoracic aorta with artificial vascular graft. Results： Seven TAR patients were successfully salvaged. Three patients combined brain injury as well as extremitiy hemiplegia before operation. After treatments one was fully and two partially recovered without paraplegia. Conclusions： Proper practical protocol is emphasized for the surgical repair of TAR because it will reduce the mortality of severe blunt chest injury.

Feasibility analysis of rapid right ventricular pacing in thoracic endovascular aortic repair under local anesthesia

Background Rapid right ventricular pacing is one of the methods for counteracting the ＂wind sock＂ effect in the thoracic endovascular aortic repair （TEVAR）. Most of the doctors are to complete this operation under general anesthesia. Now, our operation has been performed under local anesthesia. No related reports were found as to whether can the patient tolerate rapid fight ventficular pacing under local anesthesia. Methods From 2009 January to 2010 January, in our hospital all the DeBakey llI aortic dissection patients who underwent TEVAR were randomly divided into general anesthesia group （n = 50） and local anesthesia group （n = 51）. All the data were compared between two groups including the hemodynamic indexes, the graft positioning accuracy, rapid pacing duration, operation time, intraoperative discomfort and postoperative neurological understanding function changes and the complications. Results The success rate were 100% in the two groups. The duration of rapid pacing, operation time, the accuracy of graft localization and the intraoperative discomfort scores of Numerical Pain Rating Scale showed no significant difference between the two groups （P 〉 0.05）. There were no rapid fight ventricular pacing-related complications in the two groups. Conclusion During thoracic endovascular aortic repair procedure, rapid fight ventricular pacing under local anesthesia is safe and feasible. Thus it is worthy to be popularized in clinical practice.

Strategies for managing the insufficiency of the proximal landing zone during endovascular thoracic aortic repair

Background The insufficiency of the proximal landing zone (PLZ) is a frequent factor challenging the applicability and efficacy of endovascular repair (EVR) for thoracic aortic disorders. This study discusses two strategies for conquering this challenge.Methods Ten patients underwent EVR for thoracic aortic diseases during a one-year period ending June 30, 2004. Nine patients had DeBakey type Ⅲ dissecting aortic aneurysm (DAA), and one had descending thoracic aortic aneurysm (DTAA). The PLZ, defined as the distance from the origin of the left subclavian artery (LSA) to the primary entry tear of the dissection or to the proximal aspect of DTAA, was less than 15 mm in all instances. EVR with intentional coverage of the LSA without any supportive bypass was employed in 6 patients with DAA, and the preliminary right-left carotid and left carotid-subclavian bypass combined with EVR in the DTAA and other 3 DAA cases. Results Technical success was achieved in all the patients. The patient with DTAA died from hemispheric cerebral infarction and subsequent multiple system organ failure following an uneventful recovery from the cervical reconstruction performed 1 week previously. In cases receiving the EVR with intentional coverage of the LSA, in two patients dizziness occurred, which noticeably resolved after intravenous administration of mannitol for 4 to 5 days, and a drop in blood pressure of the left arm was noted in all the cases, but remained clinically silent. No neurological deficits or limb ischaemia developed perioperatively or during the followup, ranging from 3 to 12 months, and complete thrombosis of the thoracic aortic false lumen was revealed on CT at 3 months in the 9 patients with DAA.Conclusions Both the intentional bypass absent coverage of the LSA and the adjunctive surgical bypass appear to be feasible and effective in managing the insufficiency of the PLZ during the endovascular thoracic aortic repair.

Vasorelaxant effect of osthole on isolated thoracic aortic rings in rats

OBJECTIVE: To investigate the effect of osthole on isolated thoracic aortic rings, and to determine the potential mechanism of action.METHODS: Thoracic aortas were isolated from Wistar rats, and were suspended in tissue organ chambers for vascular tension measurement. The effect of cumulative osthole(10-9, 10-8, 10-7, 10-6, and 10-5 mol/L) on endothelium-intact and endothelium-denuded thoracic aortic rings pre-contracted with phenylephrine(PE, 10-6 mol/L) or KCl(6 × 10-2 mol/L) was recorded. Histomorphological changes of thoracic aorta were analyzed by hematoxylin-eosin. The effects of different osthole concentrations on endothelium-intact aortic rings, which were pre-inhibited with the non-selective nitric oxide synthase inhibitor L-Arg(NO2)-OMe·HCl(3 × 10-4 mol/L), endothelium-derived nitric oxide synthase inhibitor Nω-nitro-L-arginine(3 × 10-4 mol/L), guanylate cyclase inhibitor 1 H-[1,2,4] oxadiazolo [4,3-α]quinoxaline-1-one(10-5 mol/L), cyclooxygenase inhibitor indometacin(10-5 mol/L), and the Ca2+-activated potassium channel inhibitor tetraethylammonium nitrate(10-5 mol/L), and then contracted with PE, were examined. Aortic rings incubated with osthole(10-5 mol/L), phentolamine(10-5 mol/L), or verapamil(10-5 mol/L) in Ca2+-free Krebs-Henseleit solution(KHS) were stimulated with PE or KCl.RESULTS: There was a dose-dependent increase in vasorelaxation of isolated thoracic aortic rings(both with and without endothelium) with increasing osthole concentration. Hematoxylin-eosin staining showed that osthole significantly improved thoracic aorta ring morphology. Compared with the control group, there were also significant differences after incubation with L-Arg(NO2)-OMe ω-nitro-L-arginine, and 1 H-[1,2,4] oxadiazo·lo HCl,N [4,3-α] quinoxaline-1-one(P < 0.05 for all). The relaxation rate of the rings in the osthole group incubated with indometacin and tetraethylammonium nitrate were similar to controls. In Ca2+-free KHS, the PE-induced contraction was similar between the osthole(4.37% ± 0.41%) and control(4.21% ± 1.33%)groups. However, after cumulative CaCl2(0.5, 1, 1.5,2, 2.5, and 3 mmol/L), the Ca2+-induced contraction was significantly inhibited in the osthole and phentolamine groups compared with controls(P < 0.05).After cumulative CaCl2 was added to Ca2+-free KHS(high K+ concentration), the contraction rate was significantly higher than both of the control and the osthole groups(P < 0.05). The contraction rate in the osthole group was higher than the verapamil group(P < 0.05).CONCLUSION: Osthole has a vasorelaxant effect on isolated rat thoracic aortic rings, via inhibition of both receptor-operated and voltage-dependent Ca2+channels in arterial smooth muscle, leading to decreased Ca2+ influx, and via inhibition of nitric oxide release on arterial endothelial cells.

Effects of TanshinoneⅡA on the Myocardial Hypertrophy Signal Transduction System Protein Kinase B in Rats

Objective： To study the effect of tanshinone ⅡA on the cell signal transduction system protein kinase B （Akt） in rats with hypertrophy of the myocardium induced by partial constriction of the thoracic aorta. Methods： Rat models of myocardial hypertrophy were established by the thoracic aorta partial constriction method. Forty-eight rats were randomly divided into the sham-operative group, the model group, the valsartan treatment group, and the low-, medium-, and high-dose tanshinone treatment groups. The heart mass index （HMI）, left ventricular mass index （LVMI）, ejection fraction （EF）, left ventricular posterior wall （LVPW）, and interventricular septal thickness （IVS） were detected by high-frequency ultrasonography. The myocardial fiber diameter （MFD） was detected by HE staining, and the contents of p-Akt and p-Gsk3β in the myocardium were detected by Western blot. Results： Compared with the sham-operative group, the levels of HMI, LVMI, LVPW, IVS, and MFD were increased respectively in the other groups （P〈0.05）; the contents of p-Akt and p-Gsk3β were also increased in the other groups. Compared with the model group, the levels of HMI, LVMI, LVPW, IVS, and MFD were decreased respectively in all treatment groups （P〈0.05）; the contents of p-Akt and p-Gsk3β were decreased in all treatment groups as well. There was no significant difference, however, among the low-, medium-, and high-dose tanshinone treatment groups and the valsartan treatment group （P〉0.05）. Conclusion： Tanshinone HE A can prevent myocardial hypertrophy by its action on the protein kinase B （Akt） signaling pathway.

Application of transesophageal echocardiography to aortic embolic stroke

OBJECTIVES: To determine the relative value of transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) in exploring the potential embolic source (PES) in heart and aortic arch and to study the clinical significance of aortic arch atherosclerosis (AAA). METHODS: Forty-nine patients with cerebral embolism were included in this study. TEE and TTE were used to evaluate the potential source of emboli in aortic arch, heart and duplex in the carotid artery. An atherosclerotic lesion of the aortic arch was defined as normal, mild plaque, moderate plaque, and protruding plaque or mobile plaque. RESULTS: Of the 49 patients, 31 (63%) patients showed evidence of AAA: 7 (14.1%) patients were mild, 9 (18.4%) were moderate and 15 (30.6%) were severe. In those 15 patients, 11 had neither severe ICAA nor heart disease. Thirty-three patients had internal carotid arterial atherosclerosis (ICAA). The potential sources of embolization of heart and aortic arch is 48.98% by TEE, but only 18.4% by TTE; 9 patients had heart disease. Age and ICAA were significantly correlated with AAA. CONCLUSION: At present, TEE is a better method for exploring atherosclerotic lesions in the thoracic aorta. AAA is an important potential source of cerebral embolic stroke.