Imaging of thoracic aortic dissection

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.     

带股骨大粗隆稳定钢板的动力髋螺钉在不稳定型股骨粗隆间骨折

不稳定型股骨粗隆部骨折采用动力髋螺钉（DHS）固定效果欠佳，术后可出现骨折再移位、内固定松动、并发髋内翻畸形等.自2003年7月-2005年12月，采用DHS加TSP（股骨大粗隆稳定钢板），对32例不稳定型股骨粗隆部骨折进行了手术治疗，临床效果满意，现报告如下。     

Alcohol septal ablation versus surgical septal myectomy: comparison of effects on atrioventricular conduction tissue

OBJECTIVES: This study was designed to evaluate the effect of septal reduction therapies on the conduction system for patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: Heart block is a potential complication of both catheter-based and surgical procedures to relieve left ventricular outflow tract obstruction in HCM, but it is important to understand the different effects of these treatments on the conduction system. METHODS: The electrocardiograms and postoperative course of patients who underwent percutaneous alcohol septal ablation or surgical myectomy at Mayo Clinic between 1999 and 2003 were reviewed. RESULTS: For the 58 patients who underwent alcohol septal ablation, 21 (36%) developed right bundle branch block. Six patients (12%) developed complete heart block requiring permanent pacing, three of whom had left bundle branch block before the procedure. Among the 117 patients who underwent surgical septal myectomy, 47 (40%) developed left bundle branch block. Four patients (3%) developed heart block requiring permanent pacing after the procedure, three of whom had right bundle branch block preoperatively. CONCLUSIONS: Percutaneous septal ablation selectively produces transmural infarction of the basal mid-septum and adjacent right bundle tissue, whereas surgical myectomy affects the endocardial portion of the basal anterior septum and adjacent left bundle tissue. These observations may help identify patients at risk for complete heart block after septal reduction procedures for HCM.     

Molecular mechanisms accounting for fibrinogen deficiency: from large deletions to intracellular retention of misfolded proteins

Summary.  Fibrinogen, the soluble precursor of fibrin, which is the main protein constituent of the blood clot, is synthesized in hepatocytes in the form of a hexamer composed of two sets of three polypeptides (Aα, Bβ, and γ). Each polypeptide is encoded by a distinct gene, FGA, FGB and FGG , all three clustered in a region of 50 kb on 4q32. Congenital afibrinogenemia is characterized by the complete absence of fibrinogen. The first causative mutation for this disease was identified in Geneva in a non-consanguineous Swiss family in 1999: the four patients were homozygous for a large deletion in the fibrinogen cluster, which eliminated almost the entire FGA genomic sequence. Mutations in the fibrinogen genes may lead to deficiency of fibrinogen by several mechanisms: acting at the DNA level, at the RNA level by affecting mRNA splicing or stability, or at the protein level by affecting protein synthesis, assembly or secretion. Recent reviews have provided helpful updates for the rapidly growing number of causative mutations identified in patients with fibrinogen deficiencies, either afibrinogenemia or hypofibrinogenemia. The aim of this review is to highlight specifically the subset of mutations that allow fibrinogen chain synthesis and hexamer assembly but impair secretion. Indeed, functional studies of these mutations have shed light on the specific sequences and structures in the fibrinogen molecule involved in the quality control of fibrinogen secretion.     

AG825对乳腺癌细胞的辐射增敏作用

目的：通过体外实验观察酪氨酸蛋白激酶抑制剂AG825对人类表皮生长因子受体2（ERBB-2）高表达乳腺癌细胞的生长抑制作用和辐射增敏作用，并从DNA双链断裂（Double strand break，DSB）损伤修复的角度初步探讨AG825辐射增敏机制。方法：首先通过MTT比色法观察了不同浓度AG825对ERBB-2高表达乳腺癌细胞系MDA—MB-453生长抑制作用。然后将细胞设为空白对照组，单纯放射组，AG825预处理组。通过克隆形成实验观察AG825预处理组和单纯辐射组乳腺癌细胞辐射后生存分数（Survivial fraction，SF）的差异。并且通过单细胞中性凝胶电泳分析了AG825预处理对辐射诱导的DSB的影响。同时用免疫印记法分析AG825预处理后MDA—MB-453细胞在辐射后不同时间DSB修复的关键激酶DNA依赖蛋白激酶催化亚单位（DNA dependent protein kinase catalytic subunit，DNA—PKcs）蛋白的表达情况。结果：MTT比色法显示AG825对MDA—MB-453生长抑制作用随AG825浓度增高而增加。辐射后单纯放射组MDA—MB-453细胞生存分数较空白对照组明显下降。AG825预处理组辐射后生存分数较单纯放射组进一步下降，同时DSB较单纯放射组增加。免疫印记显示单纯放射组DNA—PKcs蛋白表迭在辐射后较空白对照组增加，而AG825预处理组DNA—PKcs表达较单纯放射组下降。结论：AG825对ERBB2高表达乳腺癌细胞具有生长抑制作用一、并且其对ERBB2高表达乳腺癌细胞具有辐射增敏作用，其辐射增敏机制可能与AG825抑制DNA—PKes蛋白表达而减少辐射后DSB修复有关。但还需进一步的体内实验来评价AG825辐射增敏作用。     

Postoperative radiotherapy in stage I endometrial adenocarcinoma

OBJECTIVE: To evaluate postoperative whole pelvic radiation for high-risk patients with Stage I endometrial adenocarcinoma. METHODS: One hunderd and twenty-two patients with irregular premenopausal or postmenopausal haemorrhage were included into the study. Fractional curettage was performed in all cases. When the pathohistological report confirmed endometrial adenocarcinoma, abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Low-risk patients include women with Stage IA tumours and Stage IB grade 1 or 2 histology. High-risk group include patients with Stage IB grade 3 tumours and Stage IC carcinomas. High-risk patients received whole pelvic radiotherapy between two and four weeks after surgery. RESULTS: Eighty-two patients (67.21%) were low-risk and forty patients (32.79%) were high-risk. In the low-risk group of patients, CA-125 was negative in ten cases and positive in 72 patients with a mean value of 30.12 +/- 12.42 U/ml serum. In the high-risk group of the patients, CA-125 was negative in two cases and positive in 38 patients with a mean value of 60, 48 +/- 20, 14 U/ml serum. Locoregional recurrences were diagnosed in four patients (4.87%) in the surgery group and in two patients (5.00%) assigned to radiotherapy. The incidence of distant metastases was 2.43% in the surgery group and 2.50% in the radiotherapy group. Overall survival at five years was 90.25% in the low-risk group and 87.50% in the high-risk group of patients. CONCLUSION: Five-year overall survival, locoregional and distant metastasis were similar in the low-risk and high-risk groups of patients. That emphasizes the value of whole pelvic radiation in patients with unfavourable prognostic factors in Stage I endometrial cancer.     

Influence of preoperative lipid-lowering therapy on postoperative outcome in patients undergoing coronary artery bypass grafting

Statin therapy has recently been shown to decrease adverse perioperative events in patients undergoing vascular surgery. The potential beneficial effect of lipid-lowering therapy in patients undergoing coronary artery bypass grafting (CABG) is not well known. This was an observational analysis of 4,739 patients who underwent first-time isolated CABG at a single institution from 1995 to 2001. Patients were categorized into 2 groups based on treatment with a lipid-lowering agent within 30 days before surgery. Univariate and multivariate analyses were used to determine the association between lipid-lowering therapy and survival to hospital discharge. Patients in the lipid-lowering group (n = 2,334) tended to be younger (mean age 66 +/- 10 vs 68 +/- 10 years), were more likely to be diabetic (31% vs 28%), and on beta blockers (77% vs 70%) than patients in the nonlipid-lowering group (n = 2,405). In-hospital mortality was significantly lower in the lipid-lowering group than in the nonlipid-lowering therapy group (1.4% vs 2.2%, odds ratio 0.62, 95% confidence interval 0.40 to 0.96, p = 0.03). A multivariable model demonstrated a loss of statistical significance for the effect of lipid-lowering therapy on in-hospital mortality (adjusted odds ratio 0.83, 95% confidence interval 0.5 to 1.37, p = 0.46). In conclusion, preoperative use of lipid-lowering therapy in patients undergoing CABG appears safe and is associated with improved survival to hospital discharge compared with patients not receiving lipid-lowering therapy. However, patient risk factors and other cardioprotective medication use associated with the use of preoperative lipid-lowering therapy appear to explain the association with improved survival.     

Alcohol septal ablation for hypertrophic cardiomyopathy: indications and technique.

Alcohol septal ablation for the treatment of hypertrophic cardiomyopathy has been the subject of great interest, and the number of procedures performed is increasing despite an absence of randomized trial data. Although straightforward in concept, alcohol septal ablation may be considerably more difficult in actual practice. To optimize the results and prevent complications, the anatomy of the septal arcade architecture must be understood and the anatomic relationship between the septal artery and the specific portion of the septum to be ablated must be carefully delineated. For the latter, during the procedure, an echocardiographic contrast medium injection into the septal artery of interest is essential. Selection of the volume and amount of alcohol to be injected varies depending on the size and distribution of the septal artery. Specific complications such as conduction defects, hemodynamic compromise, ventricular arrhythmias, and inadequate gradient reduction can be minimized by specific technical approaches. After ablation, protocols are needed for periprocedural guidelines because some complications may occur late during the next several days. For optimal results, patients need to be selected after catheter assessment and combined echocardiography and angiography, and ablation techniques need to be scientific and rigorous.     

尼可地尔治疗微血管性心绞痛的疗效及其对血管内皮功能的影响

目的探讨尼可地尔治疗微血管性心绞痛的临床疗效及其对血管内皮功能的影响。方法选择100例微血管性心绞痛患者,随机分为研究组和对照组各50例。对照组给予常规抗心绞痛治疗,研究组在对照组用药基础上给予尼可地尔片连续治疗3个月。治疗前后测定血浆内皮索（ET-1）、一氧化氮（NO）及血清高敏C反应蛋白（hs-CRP）水平。结果研究组症状疗效总有效率为94．0％,对照组为76．0％,差异有统计学意义（P〈0．05）。研究组心电图疗效总有效率为90．0％,对照组为72．0％,差异有统计学意义（P〈0．05）。研究组治疗后与治疗前比较NO水平显著升高,ET-1及CRP水平显著减低,差异均有统计学意义（P〈0．01）。结论尼可地尔通过抑制炎症因子、改善血管内皮功能机制改善微血管性心绞痛症状,且疗效显著。