应用高频超声评价小鼠缺血性心肌病左室重塑的实验研究

目的应用15MHz线阵超声探头评价小鼠缺血性心肌病左室重塑的发生规律，探讨缺血性心肌病左室形态功能障碍的发生机制。 方法60只昆明小鼠随机分为两组，其中一组45只小鼠行开胸左冠状动脉高位结扎术为手术组，另一组15只仅开胸不结扎左冠状动脉为假手术组。两组应用15MHz高频线阵探头分别于术前、术后1、2、4、6周行经胸心脏超声检查。并于术后6周时行微导管血流动力学及病理学检查。 结果超声观察到缺血性心肌病左室重塑开始于模型制作成功后第1周，并于第6周最为显著，表现为：早期梗死区的过度伸展，左室舒、缩末内径，左室舒张末外径，左室质量显著增加（P均〈0．05），左室前壁厚度、左心室短轴缩短率和血流动力学指标的显著降低（P均〈0．05）。 结论高频超声是一种可靠无创的连续评价手段，小鼠心肌缺血后梗死区的早期伸展是左室发生心肌病样重塑的主要原因。     

Are there gender differences in left ventricular remodeling after myocardial infarction in rats?

Objective

An unclear issue is whether gender may influence at cardiac remodeling after myocardial infarction (MI). We evaluated left ventricle remodeling in female and male rats post-MI.

Methods

Rats were submitted to anterior descending coronary occlusion. Echocardiographic evaluations were performed on the first and sixth week post-occlusion to determine myocardial infarction size and left ventricle systolic function (FAC, fractional area change). Pulsed Doppler was applied to analyze left ventricle diastolic function using the following parameters: E wave, A wave, E/A ratio. Two-way ANOVA was applied for comparisons, complemented by the Bonferroni test. A P≤=0.05 was considered significant.

Results

There were no significant differences between genders for morphometric parameters on first (MI [Female (FE): 44.0±5.0 vs. Male (MA): 42.0±3.0%]; diastolic [FE: 0.04±0.003 vs. MA: 0.037±0.005, mm/g] and systolic [FE: 0.03±0.0004 vs. MA: 0.028±0.005, mm/g] diameters of left ventricle) and sixth (MI [FE: 44.0±5.0 vs. MA: 42.0±3.0, %]; diastolic [FE: 0.043±0.01 vs. MA: 0.034±0.005, mm/g] and systolic [FE: 0.035±0.01 vs. MA: 0.027±0.005, mm/g] of LV) week. Similar findings were reported for left ventricle functional parameters on first (FAC [FE: 34.0±6.0 vs. MA: 32.0±4.0, %]; wave E [FE: 70.0±18.0 vs. MA: 73.0±14.0, cm/s]; wave A [FE: 20.0±12.0 vs. MA: 28.0±13.0, cm/s]; E/A [FE: 4.9±3.4 vs. MA: 3.3±1.8]) and sixth (FAC [FE: 29.0±7.0 vs. MA: 31.0±7.0, %]; wave E [FE: 85.0±18.0 vs. MA: 87.0±20.0, cm/s]; wave A [FE: 20.0±11.0 vs. MA: 28.0±17.0, cm/s]; E/A [FE: 6.2±4.0 vs. MA: 4.6±3.4]) week.

Conclusion

Gender does not influence left ventricle remodeling post-MI in rats.     

Closed vs open reduction in developmental dysplasia of the hip: The short-term effect on acetabular remodeling

BackgroundThis study aims to assess acetabular remodeling following closed vs, open hip reduction in children younger than 2 years of age.MethodsRecords of children with DDH, who underwent closed or open reduction, were reviewed. Acetabular index (AI) was measured on radiographs taken prior to reduction and on outcome radiographs taken at age 4 years. Radiographic outcomes were analyzed and residual dysplasia (outcome AI ≥ 30) degrees recorded.Results42 hips had closed reduction; and 26 hips had open reduction. A higher percentage of hips treated with successful closed reduction, had outcome AI ≥ 30° (29% vs. 19% p = 0.387). Residual dysplasia was more common in IHDI-IV hips than IHDI-III hips for both groups. A higher incidence of AVN was seen in the open reduction group (13% vs. 7%; p = 0.43).ConclusionIn children with DDH under the age of two, open reduction with capsulorrhaphy may benefit acetabular remodeling more so than closed reduction despite maintenance of reduction. Although AVN remains a risk, higher remodeling might be expected with open reduction.     

Application of adjusted subpixel method (ASM) in HRCT measurements of the bronchi in bronchial asthma patients and healthy individuals

Background

Recently, we described a model system which included corrections of high-resolution computed tomography (HRCT) bronchial measurements based on the adjusted subpixel method (ASM).

Objective

To verify the clinical application of ASM by comparing bronchial measurements obtained by means of the traditional eye-driven method, subpixel method alone and ASM in a group comprised of bronchial asthma patients and healthy individuals.

Methods

The study included 30 bronchial asthma patients and the control group comprised of 20 volunteers with no symptoms of asthma. The lowest internal and external diameters of the bronchial cross-sections (ID and ED) and their derivative parameters were determined in HRCT scans using: (1) traditional eye-driven method, (2) subpixel technique, and (3) ASM.

Results

In the case of the eye-driven method, lower ID values along with lower bronchial lumen area and its percentage ratio to total bronchial area were basic parameters that differed between asthma patients and healthy controls. In the case of the subpixel method and ASM, both groups were not significantly different in terms of ID. Significant differences were observed in values of ED and total bronchial area with both parameters being significantly higher in asthma patients. Compared to ASM, the eye-driven method overstated the values of ID and ED by about 30% and 10% respectively, while understating bronchial wall thickness by about 18%.

Conclusions

Results obtained in this study suggest that the traditional eye-driven method of HRCT-based measurement of bronchial tree components probably overstates the degree of bronchial patency in asthma patients.     

干细胞修补缺血性心肌

在适当的细胞培养条件下,干细胞有分化为心肌细胞和内皮细胞的能力,如果在体内能繁殖出同样的结果,那么对于急、慢性心肌损伤病人,利用干细胞阻断心力衰竭进行性恶化,甚至恢复心功能成为可能,现综述干细胞治疗理论基础的基本观点,并回顾支持其潜在价值的当前实验室证据,同时描述干细胞治疗心肌损伤的临床选择和可能的不足,这些还需要随机化临床试验进一步评价。     

Ionic Remodeling and Direct Effects of Valsartan on Ionic Currentsin Human Atrial Myocytes with Atrial Fibrillation

Objectives Previous studies demonstrated that angiotensin receptor antagonists had effects on some potassium channels in guinea pig myocytes and cloned channels that expressed in human cardiac myocytes. This study determined the direct effects of Valsartan on I caL, INa, IKur, IK1 and Ito1 in isolated human atrial myocytes. Methods and Results Specimens of right atrial appendage tissue were obtained from 39 patients with coronary artery and valvular heart diseases during cardiopulmonary bypass procedure. Pre- operation cardiac rhythm was sinus (SR)in 19 patients and was atrial fibrillation (AF) in the others. Single atrial myocyte was isolated by enzymatic dissociation with the chunk method. The ionic currents were recorded using the whole cell coffiguration of the voltage clamp technique. ICaL and Ito1 densities in AF patients were significantly lower than those in SR patients by 74% and 60%, respectively, while IK1density was significantly higher by 34% at command potential of - 120 mV. With 10 μmol/L Valsartan, INa density was significantly decreased by 59% in SR patients and by 66% in AF patients. IKur and IKl density were significantly decreased in only AF patients by 31% and23%, respectively. Conclusions Conclusions Decreased IcaL and Itol and increased IKl at hyperpolarizing potentials in AF patients‘ atrial myocytes may result from the electrophysiological remodeling by AF. Valsartan significantly decreases INa, IK1 and IKur current densities in AF patients‘ myocyte, but decreases only INa in SR patients‘ myocyte, suggesting that Valsartan may be beneficial to the recovering of remolded atria.     

心区交感神经阻滞对扩张型心肌病左室重塑的影响

目的　探讨心区交感神经阻滞对扩张型心肌病 (dilatedcardiomyopathy,DCM)左室重塑的影响 ,以寻求DCM治疗新法。方法　 2 0 0 0年 5月至 2 0 0 2年 5月临床诊断为DCM患者 6 0例 (符合WHO标准 ) ,随机分成治疗组和对照组。治疗组实施上胸段硬膜外阻滞 ,4周一疗程 ,适当辅以常规药物。对照组仅给予常规药物治疗。应用彩色多普勒超声诊断仪常规方法测量左室重塑指标。结果　治疗组症状体征缓解迅速 ,而对照组缓解较慢 ,有的患者无效甚至加重。治疗组收缩功能提高 ,左室重塑指标得以改善[LVEDD (71 7± 9 3)mmvs (6 6 2± 8 8)mm ,EF (31 1± 17 0 ) %vs (36 6± 12 0 ) % ,FS (12 0± 1 0 ) %vs(15 0± 3 0 ) % ,LVEDV (393 3± 14 4 8)mlvs (343 2± 137 1)ml,LVESV (2 82 5± 12 1 1)mlvs (2 2 7 3±10 8 6 )ml,LVmass (394 3± 10 0 7)gvs (372 1± 93 2 )g,P <0 0 5 ],而对照组无改善。结论　心区交感神经阻滞治疗DCM能中止并逆转DCM左室重塑。     

Aortoiliac remodeling and 5-year outcome of an ultralow-profile endograft

BackgroundRemodeling of the aortoiliac anatomy is a challenge to the long-term performance of stent grafts for endovascular aneurysm repair. Changes in vessel diameter and length can result in loss of seal at attachment sites, limb disunion, or kinking, with the development of high-pressure endoleaks, migration, or limb occlusion. The aim of this study was to assess the durability and conformability of the ultralow-profile INCRAFT AAA endograft (Cordis Corporation, Milpitas, Calif) during 5-year follow-up.MethodsFrom 2010 to 2011, there were 60 patients (median age, 74 years; range, 60-94 years) with intact abdominal aortic aneurysms who were enrolled in the INNOVATION trial to evaluate the safety, effectiveness, and durability of the INCRAFT AAA device. Clinical and technical success was assessed with protocol-specified, monitored follow-up clinic visits and core laboratory-assessed computed tomography (CT) at 1 month, 6 months, and 12 months after implantation and annually through 5 years thereafter. Diameter and angulation changes at the proximal aortic neck and diameter changes at the iliac attachment zones were measured in addition to the standard CT assessments.ResultsSignificant aortoiliac remodeling was observed throughout long-term follow-up after endovascular aneurysm repair. Proximal aortic neck diameter 15 mm below the lowest main renal artery increased from 23.5 ± 2.5 mm at 1 month to 27.3 ± 2.8 mm at 5 years (P = .002). Neck dilation >5 mm was observed in 8 of 38 patients with 5-year CT studies (21%). The aortic neck straightened, with angulation decreasing from 34 ± 14 degrees preoperatively to 31 ± 11 degrees at 1 month (P < .001) and to 20 ± 12 degrees at 5 years (P = .018). Straightening of the neck was most prominent in patients who presented with a high degree of preoperative angulation (r = 0.61; P < .001). Between 1 month and 5 years, iliac attachment zone diameter increased from 13.5 ± 1.9 mm to 15.0 ± 2.4 mm on the right (P = .002) and from 13.9 ± 2.3 mm to 16.8 ± 2.7 mm on the left (P < .001). During 5 years, 9 of 72 (13%) iliac arteries enlarged >5 mm. There was a significant relationship between main body oversizing and aortic neck enlargement (r = 0.42; P = .009). No similar association was observed between iliac limb oversizing and iliac dilation over time (r = 0.10 and P = .549, right side; r = 0.14 and P = .400, left side). There were no aneurysm-related deaths in the series. There were two type IA endoleaks, both of which were present on the 1-month CT scan and associated with challenging aortic neck anatomy. No patient experienced endograft migration or rupture through 5 years. Type IB endoleaks occurred in two patients, both accompanied by iliac artery dilation and loss of seal. Stent fracture occurred in two struts of the bare transrenal stent of one patient, without loss of fixation or seal. One patient experienced graft limb occlusion and was observed without intervention. There were three patients (5%) with aneurysm sac enlargement (>5 mm) through 5 years, each of whom had type II endoleak.ConclusionsSignificant aortoiliac remodeling occurs after endograft implantation, including proximal aortic neck dilation, straightening of the neck, and iliac artery enlargement. The ultralow-profile INCRAFT device adapted well to these changes, with acceptably low 5-year rates of device-related endoleaks, endograft migration, and limb occlusion.