Occlusion versus shunting during MIDCAB: effects on left ventricular function and quality of anastomosis

BACKGROUND: Minimally invasive direct coronary artery bypass is an established clinical procedure for revascularization of the left anterior descending coronary artery. Mechanical stabilization and temporary occlusion is currently used to perform the anastomosis of the internal thoracic artery to the left anterior descending coronary artery. However, critical reduction of cardiac function can occur as a result of temporary ischemia. The purpose of this study was to evaluate whether ischemic sequelae can be avoided by using temporary intraluminal shunts and whether this alters early outcome. METHODS: Thirty-five patients underwent minimally invasive direct coronary artery bypass revascularization using a mechanical stabilizer. In group A (n = 20), the anastomotic site was temporarily occluded by tourniquets. In group B (n = 15), temporary intraluminal shunts were inserted into the anastomotic site without any occlusion of the left anterior descending coronary artery. Anastomosis of the internal thoracic artery to the left anterior descending coronary artery was performed in an identical fashion. A Swan-Ganz catheter was inserted, and transesophageal echocardiographic measurements were obtained for analysis of left ventricular (LV) function. Regional wall motion, cardiac index, stroke volume index, systolic and diastolic LV diameters, and fractional area change were measured during four periods: at the start of the operation (baseline), placement of the stabilizer (stabilization), left anterior descending coronary artery occlusion (occlusion) or insertion of temporary intraluminal shunts (shunt), and 30 minutes after reperfusion (reperfusion). Angiograms were obtained 4 to 6 days postoperatively. RESULTS: In group A, LV performance, cardiac index, stroke volume index, and fractional area change decreased during occlusion whereas systolic diameters increased. Almost two myocardial segments per patient developed severe hypokinesia in the perfusion area. These changes disappeared after 30 minutes of reperfusion, with increased LV function. In group B, LV function remained stable whereas hypokinetic wall motion was only detected in 2 patients. Early angiograms revealed 90% of the grafts were patent in group A versus 100% in group B. The need for percutaneous intervention during the first 6 months was 20% in group A versus 6.7% in group B. CONCLUSIONS: The use of temporary intraluminal shunts resulted in reduced acute ischemia and revealed wall motion abnormalities and maintained LV function. Furthermore, this technique suggests an improvement of early graft patency and a lower reintervention rate within the first 6 postoperative months. Thus, use of temporary intraluminal shunts appears to be superior to the occlusion technique early after minimally invasive direct coronary artery bypass procedures.     

Advances in sensitivity encoding with arbitrary k-space trajectories.

New, efficient reconstruction procedures are proposed for sensitivity encoding (SENSE) with arbitrary k-space trajectories. The presented methods combine gridding principles with so-called conjugate-gradient iteration. In this fashion, the bulk of the work of reconstruction can be performed by fast Fourier transform (FFT), reducing the complexity of data processing to the same order of magnitude as in conventional gridding reconstruction. Using the proposed method, SENSE becomes practical with nonstandard k-space trajectories, enabling considerable scan time reduction with respect to mere gradient encoding. This is illustrated by imaging simulations with spiral, radial, and random k-space patterns. Simulations were also used for investigating the convergence behavior of the proposed algorithm and its dependence on the factor by which gradient encoding is reduced. The in vivo feasibility of non-Cartesian SENSE imaging with iterative reconstruction is demonstrated by examples of brain and cardiac imaging using spiral trajectories. In brain imaging with six receiver coils, the number of spiral interleaves was reduced by factors ranging from 2 to 6. In cardiac real-time imaging with four coils, spiral SENSE permitted reducing the scan time per image from 112 ms to 56 ms, thus doubling the frame-rate.     

Off-pump coronary artery bypass grafting for elderly patients

Background. The use of off-pump coronary artery bypass grafting (CABG) has recently become widespread, and it has been proven to be less invasive and to facilitate early recovery. In this study, we investigated the efficacy of off-pump CABG for patients aged 75 years or more.

Methods. A retrospective chart review was carried out for patients who underwent isolated off-pump and on-pump CABG at Shin-Tokyo Hospital between January 1997 and December 2000. The patients’ demographic, operative data, and postoperative results were collected.

Results. The off-pump group consisted of 60 men and 44 women with a mean age of 78.8 years, and the on-pump group consisted of 54 men and 20 women with a mean age of 77.6 years. Distal anastomoses were significantly fewer in the off-pump group (2.4 in off-pump group versus 3.7 in on-pump group), but total arterial bypass was more frequently achieved in off-pump group (82.7% versus 25.7%). Intubation time (8.4 versus 18.4 hours), intensive care unit stay (2.2 versus 3.5 days), and postoperative stay (13.8 versus 20.0 days) were significantly shorter in the off-pump group than in the on-pump group (p < 0.05). The frequency of the occurrence of major complications was significantly lower in the off-pump group than the on-pump group, especially in regard to postoperative stroke and respiratory failure (p < 0.05). Multivariate analysis showed that off-pump CABG significantly reduced patient recovery period and the incidence of postoperative complications. Early follow-up results, cardiac event-free and survival rates, did not significantly differ between the two groups.

Conclusions. Off-pump CABG is safe for the elderly patient. Off-pump CABG successfully facilitates early recovery and reduces the incidence of postoperative complications among elderly patients.     

Concomitant off-pump myocardial revascularization and pheochromocytoma resection

Surgical management of patients with coexisting ischemic heart disease and pheochromocytoma remains challenging. We present one such case in which hybrid myocardial revascularization (angioplasty with stenting and off-pump coronary artery bypass grafting) and resection of pheochromocytoma were undertaken. Unusual features included simultaneous coronary artery surgery and tumor resection and, in particular, coronary artery surgery being performed without cardiopulmonary bypass.     

慢性乙型病毒性肝炎患者外周血T淋巴细胞亚群CD27和CD28的表达

目的分析慢性乙型病毒性肝炎患者外周血T淋巴细胞亚群CD27和CD28的表达,初步探讨其分化表型。方法采集分离健康人和慢性乙型病毒性肝炎患者外周血单个核细胞(PBMC),利用多种荧光标记抗体标记细胞表面分子,再用流式细胞仪检测CD8 和CD4 T淋巴细胞表面CD27和CD28分子的表达。结果31例慢性乙型病毒性肝炎患者CD8 CD27 CD28 T细胞占CD8 T细胞(41.13±24.89)%,低于28例健康对照组的(71.93±14.47)%(P<0.05)。而CD8 CD27-CD28-T细胞占CD8 T细胞(42.16±10.98)%,显著高于健康对照组的(9.16±5.24)%(P<0.01)。慢性乙型病毒性肝炎患者CD4 CD27 CD28 T细胞(80.89±7.93)%和健康对照组(83.17±8.31)%比较,差异无统计学意义。结论健康人外周血T淋巴细胞以CD27 CD28 早期分化表型为主。而慢性乙型病毒性肝炎患者外周血中不同的亚群分化特征又有所不同,CD4 T淋巴细胞的分化表型仍然以CD27 CD28 早期分化表型为主,而CD8 T淋巴细胞中早期分化表型明显减少,晚期分化表型(CD27-CD28-)显著增加。     

氯喹通过上调泛素-蛋白酶体相关分子表达抑制LPS活化巨噬细胞的实验研究

目的 观察氯喹(chloroquine,CQ)对脂多糖/内毒素(lipopolysaccharide/endotoxin,LPS)刺激的巨噬细胞中泛素-蛋白酶体系统(ubiquitin-proteasome system,UPS)相关分子A20、TRIM33和USP28表达的影响.方法 应用LPS刺激小鼠Raw264.7细胞,荧光定量PCR检测酸化抑制剂CQ对LPS诱导锌指蛋白A20、泛素连接酶TRIM33和泛素特异性蛋白酶USP28的mRNA表达,Western blot检测CQ对LPS诱导A20和TRIM33的蛋白表达.应用siRNA转染技术沉默A20,荧光定量PCR检测CQ对LPS诱导炎性细胞因子TNF的mRNA表达.结果 与LPS对照组比较,经CQ预处理的Raw264.7细胞中,A20、TRIM33、USP28的mRNA表达均显著上调[(3.197 ±0.013) vs (1.292 ±0.009),(1.627±0.113)vs(0.797±0.083),(1.387±0.144)vs(0.742±0.061),P＜0.05],A20和TRIM33的蛋白表达也同样上调.采用siRNA干扰A20基因表达,则CQ预处理组细胞中LPS诱导的TNF-α mRNA表达显著上调[(7.650 ±0.113) vs (4.145±0.120),P＜0.01].结论 CQ可显著上调LPS活化的巨噬细胞中泛素化相关分子A20、TRIM33和USP28的表达,而干扰A20基因表达可显著上调LPS活化Raw264.7细胞中TNF-α的mRNA表达,提示泛素-蛋白酶体系统及其相关分子参与CQ抑制LPS-TLR4信号通路的活化.     

p28GANK蛋白在肝细胞性肝癌组织中的表达及其临床意义

目的：探讨p28GANK蛋白在肝细胞性肝癌（HCC）组织中的表达及其临床意义。方法收集HCC组织及其相应癌旁组织60例（其中32例伴有肝硬化组织）、正常肝组织30例,采用免疫组化法检测HCC、癌旁组织、肝硬化组织、正常肝组织组织中p28GANK蛋白的表达,分析p28GANK蛋白表达水平与HCC患者临床病理特征关系。结果 p28GANK蛋白在HCC、癌旁肝组织、肝硬化组织性、正常肝组织阳性表达率分别为71．7％、10．0％、12．5％、6．7％,HCC中p28GANK蛋白的阳性表达率高于其他组织（P＜0．05）。 HCC患者中,低分化（Ⅲ～Ⅳ级）、淋巴结和（或）远处转移及TNM分期Ⅲ＋Ⅳ者p28GANK蛋白表达阳性率分别高于高分化（Ⅰ～Ⅱ级）、无淋巴结和（或）远处转移、TNM分期Ⅰ＋Ⅱ者（P＜0．05）。结论 p28GANK蛋白表达可能与HCC的发生发展有关,p28GANK可作为HCC诊断的分子标志物。     

褪黑激素对增生性瘢痕成纤维细胞增殖的影响及机制研究

目的：探讨褪黑激素对人增生性瘢痕成纤维细胞增殖的影响及作用机制。方法收集人皮肤增生性瘢痕标本,原代培养人皮肤增生性瘢痕成纤维细胞(HSFBs)。将HSFBs细胞根据不同的处理方法分为空白对照组、低浓度褪黑激素组、中浓度褪黑激素组、高浓度褪黑激素组、NVP-BEZ235处理组、NVP-BEZ235+褪黑激素组、褪黑激素+siRNA-PTEN组、褪黑激素+siRNA-scramble组。MTT法检测各组细胞的增殖情况,qRT-PCR和Western blot检测各组细胞中磷酸酶与张力蛋白同源物(PTEN)、CyclinD1和Caspase-3的表达以及PI3k/AKt/mTOR通路相关蛋白p-Akt和p-mTOR的蛋白水平。结果与空白对照组比较,从低到高浓度褪黑激素均能够减少HSFBs细胞同一时间点OD值,上调PTEN和Caspase-3表达量,同时抑制CyclinD1、p-Akt和p-mTOR表达水平,组间差异具有统计学意义(P<0.05)。同时与高浓度褪黑激素组比较,NVP-BEZ235+褪黑激素组中细胞增殖显著被抑制,差异具有统计学意义(P<0.05);沉默PTEN后拮抗褪黑激素对HSFBs细胞增殖和PI3K/Akt/mTOR信号通路有抑制作用,差异具有统计学意义(P<0.05)。结论褪黑激素通过上调PTEN表达,抑制PI3K/Akt/mTOR信号通路活化从而抑制HSFBs细胞增殖。     

早发型重度子痫前期分娩前后CD28/CTLA-4的相关研究

目的:探讨白细胞分化抗原28/细胞毒性T淋巴细胞相关抗原4(CD28/CTLA-4)与早发型重度子痫前期发病的关系。方法:采用流式细胞技术分别测定30例早发型重度子痫前期患者分娩前后的CD28、CTLA-4、CD28/CTLA-4表达水平,同时测量各组受试者血压及肝肾功能。结果:早发型重度子痫前期患者分娩前CD3+CD4+CTLA-4+、CD3+CD8+CTLA-4+高于分娩后,CD3+CD4+CD28+/CD3+CD4+CTLA-4+、CD3+CD8+CD28+/CD3+CD8+CTLA-4+低于分娩后,差异有统计学意义(均P0.05)。CD3+CD4+CD28+/CD3+CD4+CTLA-4+、CD3+CD8+CD28/CD3+CD8+CTLA-4+两者无直线相关性(r=-0.037,P=0.844)。结论:早发型重度子痫前期患者分娩后较分娩前CTLA-4的表达下降,CD28/CTLA-4上升,可能提示CD28/CTLA-4免疫偏移与子痫前期的发生有关。