颈动脉粥样硬化斑块易损性的临床评估手段

<正>颈动脉不稳定性斑块具有薄纤维帽及脂质核心,有炎性细胞浸润、斑块内出血、表面溃疡以及斑块内存在新生血管等特征[1],较稳定性斑块容易破裂、脱落,导致原位血栓形成或产生微栓子,后者随着血流流向动脉远端,导致动脉-动脉栓塞性脑梗死。不稳定性斑块破裂是颈动脉粥样硬化性卒中发生的一个重要机制[2]。对动脉粥样硬化的病理研究是最直观、准确地获得斑块稳定性情况的手段,尸检或颈动脉内膜切除术后对患者颈动脉粥样硬化斑块     

老年患者股动脉和颈动脉及冠状动脉粥样硬化斑块稳定性的比较

目的　探讨股动脉、颈动脉、冠状动脉粥样硬化斑块的稳定性。方法　收集我院老年尸体解剖病例 15例 ,将所有病例的两侧股动脉、两侧颈动脉、左冠状动脉前降支进行连续取材 ,常规病理检查 ,部分节段行α 平滑肌肌动蛋白、CD6 8、bax染色。结果　股动脉粥样硬化斑块中的平滑肌细胞、巨噬细胞数量与颈动脉相近。与冠状动脉比较 ,股动脉粥样硬化斑块中的平滑肌细胞相对多 ,巨噬细胞相对少 ;bax在巨噬细胞的表达多 ,在平滑肌细胞的表达少。结论　平滑肌细胞、巨噬细胞数量的不同导致了 3种动脉粥样硬化斑块不同的稳定性。股动脉中的粥样硬化斑块较冠状动脉更稳定。     

乙酰肝素酶及新生血管在人颈动脉粥样硬化斑块中的表达

目的探讨乙酰肝素酶(Hpa)及新生血管在人颈动脉粥样硬化斑块中的表达特点。方法回顾性连续纳入2014年12月至2017年12月首都医科大学附属复兴医院神经外科接受颈动脉内膜切除术治疗的颈内动脉系统粥样硬化性狭窄患者55例(动脉粥样硬化组),经血管超声、CT血管成像和(或) DSA等影像学方法证实。根据美国心脏学会动脉粥样硬化组织病理学分型方法,筛选出结构清楚的晚期动脉粥样硬化斑块(Ⅳ～Ⅵ型)作为颈动脉粥样硬化斑块标本(共73个)。根据形态学分型标准,将73个颈动脉粥样硬化斑块标本分为易损斑块(42个)和移形斑块(31个)。选择同期于北京大学医学部病理学系行尸体解剖,并明确无动脉粥样硬化病变者15例为无动脉粥样硬化组(正常动脉段标本15个)。采用免疫组织化学、免疫荧光染色检测方法,分析颈动脉粥样硬化斑块内Hpa及新生血管的表达特点。结果 (1)正常颈动脉组织中无Hpa表达;颈动脉粥样硬化斑块内,Hpa阳性表达率为64. 4%(47/73)。(2)与移形斑块相比,易损斑块内Hpa阳性表达率增高[92. 9%(39/42)比25. 8%(8/31),χ~2=34. 968,P 0. 01]。(3)新生血管在颈动脉粥样硬化斑块内呈阳性表达,与移行斑块相比,易损斑块内新生血管阳性表达率更高[95. 2%(40/42)比22. 6%(7/31),χ~2=41. 060,P 0. 01]。(4)颈动脉粥样硬化斑块内,Hpa与新生血管表达主要位于斑块的纤维帽及肩部。结论 Hpa在颈动脉粥样硬化晚期病变进展过程中具有一定的作用,颈动脉粥样硬化斑块内Hpa与新生血管表达具有共区域性。     

CTA和MRA对颈动脉粥样硬化的诊断价值

我国老年患者颈动脉粥样硬化的发生率较高,约70%～80%[1],而颈动脉粥样硬化是导致缺血性脑卒中的一个重要因素.颈动脉粥样硬化所致脑血管病与颈动脉狭窄的严重性以及粥样硬化斑块的性质有密切关系.颈内动脉狭窄越显著,发生脑卒中的危险性越高,重度狭窄患者缺血性脑血管事件发生率为70%～90%[1-2].粥样斑块的性质、状态和动脉内膜表面的情况与缺血性脑血管事件密切相关. 通常认为当纤维帽很薄、不完整,有溃疡或炎性细胞浸润,坏死脂核较大或有斑块内血肿时,病灶易发生碎裂,是引起脑梗死的主要原因[3].因此对颈动脉粥样硬化的评价除管腔狭窄外,还应关注粥样硬化斑块的性质.影像学,尤其是近年来CT和MRI技术的进展在颈动脉粥样硬化斑块的评价中起着非常重要的作用.本文讲述CT血管成像(CT angiography,CTA)和MR血管成像(MR angiography,MRA)在颈动脉粥样硬化病变诊断中的价值.     

有症状颈动脉粥样硬化斑块的病理学研究现状

斑块的比较组织学研究证明,不稳定斑块的组织学特征是斑块表面溃疡形成。破裂、纤维帽变薄以及纤维帽被大量巨噬细胞和Ｔ细胞浸润。体外研究表明,巨噬细胞和Ｔ细胞释放的细胞因子和蛋白酶能破坏纤维帽胶原并使平滑肌细胞凋亡,从而促使斑块破裂。因此,颈动脉斑块表面的炎症细胞浸润可能是促使斑块破裂的关键因素,进而发生栓塞或颈动脉闭塞、进一步了解颈动脉粥样硬化中的细胞募集行为,有利于发现不稳定斑块并找到使斑块稳定的治疗方法。     

有症状颈动脉粥样硬化斑块的病理学研究现状

斑块的比较组织学研究证明，不稳定斑块的组织学特征是斑块表面溃疡形成、破裂、纤维帽变薄以及纤维帽被大量巨噬细胞和T细胞浸润。体外研究表明，巨噬细胞和T细胞释放的细胞因子和蛋白酶能破坏纤维帽胶原并使平滑肌细胞凋亡，从而促使斑块破裂。因此，颈动脉斑块表面的炎症细胞浸润可能是促使斑块破裂的关键因素，进而发生栓塞或颈动脉闭塞。进一步了解颈动脉粥样硬化中的细胞募集行为，有利于发现不稳定斑块并找到使斑块稳定的治疗方法。     

联合应用无创影像学技术预警颈动脉不稳定斑块的相关研究

目的应用高分辨率动态对比增强磁共振成像(DCE-MRI),正电子发射断层显像(PET)技术检测患者颈动脉粥样硬化斑块,比较不同斑块成分之间的炎性程度,为早期预警颈动脉粥样硬化提供临床依据。方法选取颈动脉超声下斑块厚度>2mm的患者41例,分别行DCE-MRI和PET检查。以DCE-MRI图像分析结果,依照粥样硬化斑块表面纤维帽(无纤维帽、厚纤维帽、薄纤维帽、纤维帽破裂)或斑块内血管成分(钙化、胶原、脂质、出血),分析不同斑块性质影像学区别。以DCE-MRI为向导标记PET斑块位置,计算局部放射性活度标准化靶-本底比值(TBR),将DCE-MRI及PET对比研究,比较不同成分斑块间炎性反应程度,以鉴别不稳定斑块。结果不同斑块表面纤维帽中:纤维帽破裂TBRmax值最高,无纤维帽TBRmax值最低,两者比较差异有统计学意义(P<0.01);不同斑块成分中TBRmax值由大到小排列为:斑块出血、富含脂质坏死核、斑块胶原、斑块钙化,除斑块胶原与斑块钙化比较无显著差异外,其他斑块血管成分间差异均有统计学意义(P<0.01)。结论 DCE-MRI和PET无创检查技术联合应用,可以用于颈动脉粥样硬化的早期诊断与评估。     

小檗碱在预防家兔颈动脉粥样硬化中对血管紧张素Ⅱ1型受体的影响

目的探讨小檗碱在预防家兔颈动脉粥样硬化中对血管紧张素Ⅱ1型受体的影响。方法32只雄性新西兰大白兔随机分成正常组、颈动脉粥样硬化组(模型组)、生理盐水组(对照组)、小檗碱预防组(小檗碱组)。除正常组外,其余各组建立颈动脉粥样硬化模型,术前1周分别给予对照组和小檗碱组肌注生理盐水和小檗碱,术后4周内继续进行上述干预。第5周麻醉处死后取右侧颈动脉,行HE染色和血管紧张素Ⅱ1型受体免疫组织化学染色。结果HE染色发现模型组颈动脉血管病变以泡沫细胞为主,形成动脉粥样斑块;对照组病理改变与模型组类似;小檗碱组血管内膜轻度增厚。颈动脉血管紧张素Ⅱ1型受体免疫组织化学染色发现,模型组和对照组颈动脉粥样硬化组织中平滑肌细胞和泡沫细胞胞膜血管紧张素Ⅱ1型受体表达丰富,阳性细胞数密度较正常组明显增高;小檗碱组血管中膜平滑肌细胞仅有少量血管紧张素Ⅱ1型受体表达,血管紧张素Ⅱ1型受体阳性细胞数密度明显低于对照组(P<0.05)。结论小檗碱预防颈动脉粥样硬化的形成可能与其对颈动脉组织中血管紧张素Ⅱ1型受体表达的调节有关。     

超声造影对颈动脉粥样硬化斑块稳定性评估的研究进展

脑缺血性疾病患者中约20%有颈动脉粥样硬化斑块。大量证据表明,斑块的稳定性而非血管腔狭窄程度在脑血管疾病的发病中发挥关键作用。约25%～50%的缺血性脑卒中与易损斑块脱落有关,而斑块内新生血管形成是斑块不稳定的重要标志之一。近年来,超声造影技术通过对斑块内新生血管的诊断,被广泛应用于颈动脉粥样硬化斑块的稳定性评估。     

老年脑梗死患者血浆MMP-9、CD105和TIMP-1的表达水平及其与颈动脉粥样硬化斑块稳定性的相关性

目的探讨老年脑梗死患者血浆中基质金属蛋白酶(MMP)-9、CD105及基质金属蛋白酶组织抑制剂(TIMP)-1的表达及其与颈动脉粥样硬化斑块稳定性的相关性。方法选择60例老年脑梗死患者为研究组,同期60例健康体检者为对照组,采用酶联免疫吸附法测定血浆MMP-9、CD105及TIMP-1的表达水平,颈动脉彩色多普勒超声检查患者颈动脉粥样硬化斑块稳定性,并行相关性分析。结果研究组患者的颈动脉粥样硬化斑块检出率86.67%明显高于对照组28.33%(c~2=41.773,P=0.000)。研究组患者的血浆MMP-9表达水平明显高于对照组,而CD105、TIMP-1表达水平明显低于对照组(P<0.01)。不稳定斑块组患者的血浆MMP-9表达水平明显高于对照组,而CD105、TIMP-1表达水平明显低于稳定斑块组(P<0.01)。相关性分析显示血浆MMP-9表达水平与颈动脉粥样硬化斑块稳定性呈正相关(r=0.305,P<0.05),CD105、TIMP-1表达水平与颈动脉粥样硬化斑块稳定性呈负相关(r=-0.336、-0.371,P<0.05),老年脑梗死患者血浆MMP-9、CD105及TIMP-1的表达与颈动脉粥样硬化斑块稳定性密切相关(P<0.05)。结论老年脑梗死患者颈动脉粥样硬化斑块发生率增高,血浆MMP-9水平升高,与颈动脉粥样硬化斑块稳定性正相关,CD105和TIMP-1降低与颈动脉粥样硬化斑块稳定性负相关。     

Cement and Concrete Nanoscience and Nanotechnology

Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements.     

Medical and Psychology Students' Knowledge and Attitudes Regarding Aging and Sexuality

The current study surveys medical and doctoral psychology students (N = 100) from an urban northeastern university regarding knowledge and attitudes toward elderly sexuality and aging using the Facts on Aging Quiz, the Aging Sexuality Knowledge and Attitudes Scale, and measures of interest in gerontology, academic/clinical exposure to aging and sexuality, and contact with elders. The current study found that psychology students demonstrated greater aging knowledge than medical students; however, both groups showed gaps in knowledge about sexuality. Married students had greater academic/clinical exposure and greater knowledge about aging but less permissive attitudes toward elderly sexuality. Generally, knowledge about aging was the strongest correlate of knowledge about sexuality. Level of knowledge about sexuality was not associated with attitudes. Attitudes toward sexuality and aging may be more strongly tied to demographic variables reflective of religious beliefs or adherence to sociocultural norms.     

Leptin and cellular and innate immunity in abstinent alcoholics and controls

BACKGROUND: Basic studies indicate that in vitro and in vivo doses of leptin modulate cellular immune responses. Given evidence that concentrations of leptin are altered in alcoholics who also show immune abnormalities, this study examined the relationships between circulating levels of leptin and markers of cellular and innate immunity. METHODS: Circulating levels of leptin, natural killer cell (NK) activity, interleukin-2 (IL-2)-stimulated NK activity, and concanavalin A-stimulated production of IL-2, IL-6, IL-10, and IL-12 were compared between abstinent DSM-IV alcohol-dependent men (n = 27) and age- and gender-matched controls (n = 34). RESULTS: As compared with controls, alcoholics showed lower NK activity (p < 0.01) and a trend for lower levels of leptin (p = 0.055). In the total sample, leptin predicted NK activity (beta = 0.33; p < 0.05) after controlling for the confounding influence of body mass index, alcohol intake, and smoking. Leptin was not correlated with any of the cytokine measures. To examine whether the effects of leptin were mediated by its direct action on NK, additional studies examined in vitro effects of leptin on NK activity in healthy volunteers (n = 10); leptin doses (0.1, 1, and 10 nM) yielded levels of NK activity comparable to those with media alone. CONCLUSIONS: These data show that circulating levels of leptin are associated with NK activity in humans and suggest that abnormal in vivo concentrations of leptin may contribute to the declines of NK activity in alcoholics who are at risk for infectious diseases.     

慢性饮酒、吸烟与骨质疏松的相关性研究

目的 探讨长期大量慢性饮酒、吸烟等不良生活方式与骨质疏松的关系.方法 以乏力、腰背痛、双下肢酸困为主诉,且有长期大量慢性饮酒史、吸烟史,无其他慢性疾病史的年轻男性患者45例为观察对象,测定其血钙(Ca)、血磷(P)和血肌酐(Cr)、尿素氮(BUN)、血糖(Glu)、天门冬酸氨基转移酶(AST)、丙氨酸基转移酶(ALT)、血清碱性磷酸酶(ALP)、甲状腺功能、全段甲状旁腺激素(iPTH)、1,25-二羟维生素D3[1,25-(OH) 2D3]、双能X线骨密度仪测定腰椎L1-4及左侧股骨近段(包括颈、股骨颈上部、大粗隆)骨密度(BMD),分析饮酒、吸烟对骨量的影响.以感冒发热就诊、年龄相当、无饮酒、吸烟史及慢性疾病史的45例男性为对照组.结果 观察组1,25(OH)2D3水平均降低,血钙水平偏低,血磷正常,碱性磷酸酶呈不同程度地升高,骨密度T值提示观察组27例骨质疏松,12例骨量减少,6例正常骨量;而对照组仅有6例为骨量减少,1例骨质疏松,38例为正常骨量,两组比较差异有统计学意义(P＜0.05).结论 长期慢性大量饮酒吸烟影响骨量,甚至易导致骨质疏松.     

自身免疫与动脉粥样硬化的发生发展

在动脉粥样硬化的发生发展过程中,自身免疫具有重要作用,本文就近年有关动脉粥样硬化的免疫机制的研究进展作一简要综述.     

Neutropenia and agranulocytosis in England and Wales: incidence and risk factors

The objectives of this study were to estimate the incidence of idiosyncratic neutropenia and agranulocytosis in England and Wales and to evaluate their risk factors and outcomes. The study was conducted using data from the General Practice Research Database. All cases of idiosyncratic neutropenia or agranulocytosis were identified and the incidence was estimated. This was followed by a nested case-control study, estimating odds ratios with drug exposure from conditional logistic regression. From 1987 to 1999, 3,224 patients with idiosyncratic neutropenia (50 with agranulocytosis) were identified. The incidences of neutropenia and agranulocytosis were estimated to be 120 and 7 cases per million people per year, respectively. The adjusted odds ratios for neutropenia were 34.7 (95% confidence interval 12.0-99.7) for current users of thyroid inhibitors, 9.5 (4.4-20.8) for users of disease-modifying antirheumatic drugs, and 7.6 (4.9-11.9) for users of aminosalicylates. Other drugs with statistically significantly increased risks of neutropenia included antibacterial drugs, non-opioid analgesics, NSAIDs, antidepressants, ulcer-healing drugs, and anti-epileptics. The increase in risk of neutropenia predominantly occurred during the first months of treatment. For most drugs investigated in this study, there was no relationship to daily dose. The excess 1-year mortality was low among neutropenia and agranulocytosis cases and mostly explained by the underlying disease state. In conclusion, the highest risks of neutropenia were generally found in patients starting treatment. The excess 1-year mortality was low among neutropenia and agranulocytosis cases and can be mostly explained by the underlying disease state.     

中青年超重和肥胖与高血压及高同型半胱氨酸血症的相关性研究

目的探讨中青年超重和肥胖与高血压及高同型半胱氨酸血症的相关性。方法选取2012年1月—2013年10月在我院进行常规健康体检者750例,测量受试者血压、身高、体质量及血清同型半胱氨酸(Hcy)水平。结果男性超重、肥胖检出率分别为36.87%(198/537)和13.97%(75/537),均高于女性的16.43%(35/213)和7.50%(16/213)(P0.05)。超重者和肥胖者高血压和高同型半胱氨酸血症检出率分别为21.03%(49/233)和11.16%(26/233)、46.12%(42/91)和41.76%(38/91),均高于正常者的9.16%(37/404)和2.23%(9/404),肥胖者高于超重者(P0.01)。收缩压(SBP)、舒张压(DBP)及血清Hcy与BMI呈正相关(r值分别为0.639、0.515、0.497,P0.01)。结论中青年尤其是男性超半数存在超重或肥胖,高血压及高同型半胱氨酸血症与BMI呈正相关,超重和肥胖者高血压及高同型半胱氨酸血症的发生率高,应积极防治。