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。     

细胞调亡与动脉粥样硬化

平滑肌细胞、内皮细胞和巨噬细胞与动脉粥样硬化的发生发展密切相关。在动脉粥样硬化斑块中，巨噬细胞、平滑肌细胞与内皮细胞都经历着凋亡与坏死，调亡占主导地位，参与了粥样硬化的形成过程。氧自由基、某些生长因子、一氧化氮、内毒素以及氧化型低密度脂蛋白等可诱导细胞调亡。细胞调亡具有复杂的分子调控机制，多种基因参与了凋亡的发生。     

细胞调亡与动脉粥样硬化

平滑肌细胞、内皮细胞和巨噬细胞与动脉粥样硬化的发生发展密切相关。在动脉粥样硬化斑块中，巨噬细胞、平滑肌细胞与内皮细胞都经历着凋亡与坏死，凋亡占主导地位，参与了粥样硬化的形成过程。氧自由基基、某些生长因子、一氧化氮、内毒素以及氧化型低密度脂蛋白等可诱导细胞凋亡。细胞凋亡具有复杂的分子调探机制，多种基因参与了凋亡的发生。     

巨噬细胞、血管平滑肌细胞与冠状动脉粥样硬化易损斑块的相关性研究

冠状动脉动脉粥样硬化是冠心病的病理基础,以血管壁斑块形成为特征.易损斑块定义为易于导致血栓形成或能迅速发展为罪犯病变的所有斑块,其最常见的组织学亚型具有薄纤维帽(厚度＜65μm)、大脂核(脂质池体积＞40％)、大量巨噬细胞浸润(显微镜下＞25个/0.3mm直径)以及血管正性重构等特点.研究表明,65％～70％的血栓南薄纤维帽粥样硬化斑块引起[1],它的破裂是急性冠脉综合征的发病基础.冠状动脉动脉粥样硬化的各种发病机制均与巨噬细胞和血管平滑肌细胞有紧密关系.在易损斑块中,这两种细胞成分明显有别于稳定斑块以及正常血管,主要表现为:(1)较多巨噬细胞浸润;(2)纤维帽中的血管平滑肌细胞及其分泌的细胞外基质(包括胶原纤维和蛋白多糖等)均明显减少[2].冠状动脉粥样硬化斑块的易损性与这两种细胞密切相关,故深入研究有助于认识易损斑块的发生机制并积极进行预防干预.我们就巨噬细胞和血管平滑肌细胞与冠状动脉粥样硬化易损斑块的相关性进行简要综述.     

同型半胱氨酸致动脉粥样硬化的机制

同型半胱氨酸血浓度的升高是致动脉粥样硬化的一个独立的危险因子。研究发现，同型半胱氨酸可在金属离子介导下自身氧化生成过氧化物及氧自由基，损伤内皮细胞的结构和功能，降低了内皮依赖性舒张因子──一氧化氮的生物活性，并提高血液的凝固性，从而启动了粥样硬化斑块的形成。同型半胱氨酸通过影响平滑肌细胞基因的表达，促进平滑肌细胞增殖分化及表型变化，伴脂质代谢紊乱，而导致泡沫细胞的生成，促进了粥样硬化斑块的发展。     

基质金属蛋白酶在动脉粥样硬化中的作用研究进展

动脉粥样硬化是引起冠状动脉粥样硬化性心脏病的众多因素中最重要的一种,严重威胁到人类的健康和生命。其发生源于各种原因导致的内皮细胞损伤,血管内皮的屏障功能遭受破坏,血液中的单核巨噬细胞、脂质、淋巴细胞及中性多形核白细胞广泛入侵到被剥脱的内皮下组织,发展为粥样斑块,引起血管重构,进一步导致斑块破裂,出血,继发血栓形成等。本文着重从几方面机制阐述基质金属蛋白酶削弱血管内皮细胞屏障功能,促进中层血管平滑肌细胞迁移和增殖,加重血管的结构改变,进一步促进循环炎性细胞浸润,斑块破裂,从而促进动脉粥样硬化疾病的发生、发展。     

胰岛素抵抗综合征防治进展——胰岛素抵抗与冠心病

流行病学研究证明 ,空腹血浆胰岛素水平升高是冠心病的一个独立预测指标 ,且在非糖尿病个体中尤甚。胰岛素抵抗 (IR)及其代偿性的高胰岛素血症 ,可明显增加个体冠心病的危险性 ,这是因为IR与内皮细胞损伤、平滑肌细胞增殖有密切关系。正常情况下 ,胰岛素作用于血管内皮细胞 ,产生一氧化氮 ,并刺激前列腺素释放 ,抑制内皮素释放 ,使血管扩张。IR时患者内皮细胞功能障碍 ,凝血系统激活 ,纤溶系统受抑制 ,可致脂质沉积、血栓形成和血管平滑肌增殖。巨噬细胞和纤维组织在血管内膜下形成脂肪纹 ,进一步发展为粥样硬化斑块 ,致血管壁增厚 ,管腔…     

可溶性CD40L(sCD40L)可作为预测急性冠脉综合症危险性的一项新指标

CD40L是肿瘤坏死因子超基因家族的一种,它是各种免疫与炎症调节的重要通路,包括调节动脉粥样硬化的演变.已有研究证实在动脉粥样硬化斑块内、血管内皮细胞、血管平滑肌细胞、巨噬细胞,循环中的血小板中可出现CD40L的表达.循环中出现的可溶性CD40L可能主要来源于血小板及T淋巴细胞.CD40L在急性冠脉综合征的作用与其产生的生物学效应有关.有研究发现CD40L可刺激血管内皮细胞、巨噬细胞及血管平滑肌细胞产生与动脉粥样硬化有关的生物活性因子,如E选择素、血管粘附分子、细胞因子等.CD40L还可通过调节粥样斑块的金属蛋白酶表达影响斑块的稳定性.越来越多的研究显示炎症与免疫在动脉粥样硬化的发生、发展中起着重要的作用,并且提示动脉粥样硬化可能是一种慢性炎症性疾病,炎症反应的激活可导致斑块的不稳定,从而引起急性冠脉综合征的发生.     

MMP-8在冠状动脉粥样硬化中的研究进展

正2001年前的研究都忽略了中性粒细胞胶原酶(MMP-8)在动脉粥样硬化中的作用,认为MMP-8在粥样硬化中不易表达。Herman MP等~([1])研究发现动脉粥样硬化损害中内皮细胞和巨噬细胞均表达MMP-8。2011年Sorsa T等~([2])发现MMP-8与平滑肌细胞、浆细胞及巨噬细胞中CD40、肿瘤坏死因子及脂多糖相关。MMP-8是MMP家族中的一员并且在动脉粥样硬化斑块     

基于单细胞转录组鉴定动脉粥样硬化自身免疫表征

[目的]基于单细胞转录组生物信息学方法探讨动脉粥样硬化免疫微环境特征,挖掘免疫炎症与动脉粥样硬化之间潜在的联系。[方法]从GEO数据库中提取单细胞转录组数据集GSE159677,可视化分析颈动脉粥样硬化斑块区及其近心端毗邻非斑块区细胞组成成分,利用CellChat整合细胞间通讯网络,分析细胞间交互作用差异,识别动脉粥样硬化斑块免疫炎症信号通路差异,探索动脉粥样硬化免疫微环境中细胞间受体-配体特异性变化通路。[结果]本研究从单细胞测序的视角分析了动脉粥样硬化斑块内的细胞构成和细胞通讯。研究发现,在动脉粥样硬化斑块的细胞构成中内皮细胞和平滑肌细胞减少,而T细胞、单核细胞、巨噬细胞及软骨细胞明显增加。通过细胞通讯分析,发现树突状细胞、单核细胞、巨噬细胞、自然杀伤细胞与内皮细胞间的通讯作用及部分细胞与单核细胞间的通讯作用均有显著的改变,相关信号通路包括CXCL家族与ACRK1、CCL家族与ACRK1、MIF与CD74等配体-受体互作。MIF、ANXA1、YNF、RETN、LGASL9等对单核细胞以及NAMPT、CCL2、TNFSF12对内皮细胞的通讯改变在免疫炎症反应调控动脉粥样硬化机制中起着...     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.