血管紧张素Ⅱ上调血管平滑肌细胞富含半胱氨酸蛋白61的表达

目的探讨血管紧张素Ⅱ对培养鼠血管平滑肌细胞富含半胱氨酸蛋白61的影响及其可能的转导通路。方法组织贴块法培养血管平滑肌细胞,血管紧张素Ⅱ处理平滑肌细胞15min、30min、60min、180min,PD98059在血管紧张素Ⅱ刺激细胞前1h加到培养基中,用逆转录聚合酶链反应和Westernblotting检测分析富含半胱氨酸蛋白61的表达。结果逆转录聚合酶链反应分析显示用1μmol/L血管紧张素Ⅱ刺激细胞培养15min、30min富含半胱氨酸蛋白61的表达与对照组相比明显增加;同时细胞外信号调节激酶1/2活性高于对照组(P<0.01),60min时仍有表达,180min时减弱;细胞外信号调节激酶1/2特异性抑制剂PD98059(20μmol/L)能阻断血管紧张素Ⅱ上调富含半胱氨酸蛋白61的表达并抑制增加的磷酸化细胞外信号调节激酶1/2活性。结论血管紧张素Ⅱ通过细胞外信号调节激酶1/2促进血管平滑肌细胞上调富含半胱氨酸蛋白61表达,这可能是血管紧张素Ⅱ促血管平滑肌细胞增殖的一个重要机制。     

降钙素基因相关肽抑制血管平滑肌细胞能量代谢的AMP激活蛋白激酶信号通路

目的观察降钙素基因相关肽对血管紧张素Ⅱ诱导血管平滑肌细胞增殖过程中能量代谢的影响及机制,探索细胞外信号调节激酶和AMP激活蛋白激酶相关信号蛋白在该作用中的地位。方法组织贴块法体外培养SD大鼠胸主动脉血管平滑肌细胞,取第3～10代用于实验。分别用降钙素基因相关肽或/和血管紧张素Ⅱ处理细胞。MTT法及细胞计数法观察降钙素基因相关肽对血管紧张素Ⅱ诱导大鼠血管平滑肌细胞增殖的影响;詹纳斯绿B染色观察细胞线粒体形态及体积;ATP检测试剂盒检测细胞内ATP水平;Western Blotting检测细胞磷酸化AMP激活蛋白激酶的表达。结果降钙素基因相关肽预处理能降低血管紧张素Ⅱ诱导的大鼠血管平滑肌细胞的增殖(P<0.05),同时拮抗血管紧张素Ⅱ引起细胞内线粒体肿胀、ATP水平升高,在此过程中伴随细胞内磷酸化AMP激活蛋白激酶表达下调(P<0.05);降钙素基因相关肽受体拮抗剂CGRP8-37能拮抗降钙素基因相关肽对血管紧张素Ⅱ促增殖和促代谢的抑制作用(P<0.05);细胞外信号调节激酶抑制剂PD98059能部分拮抗降钙素基因相关肽对磷酸化AMP激活蛋白激酶的抑制作用(P<0.05)。结论降钙素基因相关肽能显著抑制血管紧张素Ⅱ诱导大鼠血管平滑肌细胞增殖过程中的能量代谢,其细胞内信号通路可能涉及到降钙素基因相关肽/降钙素基因相关肽1型受体-丝裂原细胞外激酶/细胞外信号调节激酶-磷酸化AMP激活蛋白激酶信息传递链。     

氧化型低密度脂蛋白对血管平滑肌细胞小凹蛋白1表达的抑制作用及其与信号调节激酶的关系

目的 观察氧化型低密度脂蛋白对血管平滑肌细胞小凹蛋白1表达的抑制作用及其与细胞外信号调节激酶活性的关系.方法 50 mg/L 氧化型低密度脂蛋白处理血管平滑肌细胞不同时间,或同时加入25 μmol/L细胞外信号调节激酶信号通路的特异性阻断剂,Western 印迹检测血管平滑肌细胞小凹蛋白1和细胞外信号调节激酶的变化.结果 50 mg/L氧化型低密度脂蛋白作用细胞24 h后小凹蛋白1的表达明显下降,细胞外信号调节激酶磷酸化活性显著增高,阻断氧化型低密度脂蛋白对细胞外信号调节激酶的激活可显著促进小凹蛋白1的表达.结论 血管平滑肌细胞源性泡沫细胞小凹蛋白1的表达下调与氧化型低密度脂蛋白激活细胞外信号调节激酶及其介导的信号传导密切相关.     

线粒体融合素2基因突变体对大鼠血管平滑肌细胞增殖的影响

目的 研究大鼠线粒体融合素2基因的蛋白激酶A磷酸化位点两种突变体对大鼠血管平滑肌细胞增殖的影响及其相关的信号通路.方法 利用两种携带蛋白激酶A磷酸化位点突变的线粒体融合素2基因重组腺病毒(Adv-Mfn2-alaPKA和Adv-Mfn2-asnPKA)和携带线粒体融合素2基因的重组腺病毒(Adv-Mfn2),感染培养的大鼠血管平滑肌细胞.水溶性四甲基偶氮唑盐法比较各组细胞增殖的变化;流式细胞术比较各组细胞周期的变化;免疫印迹法比较各组线粒体融合素2基因和磷酸化细胞外调节激酶1/2蛋白表达变化.结果 感染重组腺病毒的三组细胞线粒体融合素2基因表达差异无显著性.与对照组相比,Adv-Mfn2-alaPKA和Adv-Mfn2组显著抑制细胞增殖(P<0.01),停滞于G_0/G_1期细胞比例显著增加(P<0.01),磷酸化细胞外调节激酶1/2蛋白表达水平显著降低(P<0.01),且Adv-Mfn2-slaPKA作用更明显(P<0.01),而Adv-Mfn2-asnPKA组较对照组差异无显著性.结论 Mfn2-alaPKA通过细胞外调节激酶1/2信号通路抑制大鼠血管平滑肌细胞增殖的作用较线粒体融合素2基因更明显;而Mfn2-asnPKA对血管平滑肌细胞无抑制增殖的作用,对细胞外调节激酶1/2信号通路也无作用.蛋白激酶A磷酸化位点是调控线粒体融合素2基因抗血管平滑肌细胞增殖的重要功能位点.     

血管紧张素(1-7)阻断细胞外信号调节激酶1/2、核因子κB信号通路影响泡沫细胞内胆固醇含量

目的研究血管紧张素(1-7)对THP-1源性泡沫细胞中细胞外信号调节激酶1/2及核因子κB信号转导通路的影响,以进一步探讨血管紧张素(1-7)促进胆固醇逆转运的调节机制以及细胞外信号调节激酶1/2与核因子κB信号通路之间是否相互影响。方法采用体外培养的THP-1单核细胞构建泡沫细胞模型,用不同的干预方法处理细胞72 h,将细胞分为单核细胞(空白对照)组、泡沫细胞组、分别预先经10-6mol/L血管紧张素(1-7)、10μmol/L核因子κB特异性阻断剂、10μmol/L细胞外信号调节激酶1/2特异性阻断剂、10-6mol/L血管紧张素(1-7)+10μmol/L核因子κB特异性阻断剂、10-6mol/L血管紧张素(1-7)+10μmol/L细胞外信号调节激酶1/2特异性阻断剂干预的泡沫细胞组。油红O染色后显微镜下观察细胞形态;高效液相色谱法检测细胞内胆固醇含量的变化;免疫组化法检测细胞内核因子κB(p65)活性的表达;免疫印迹法检测磷酸化细胞外信号调节激酶1/2蛋白的表达。结果血管紧张素(1-7)显著降低了泡沫细胞内胆固醇的含量,下调了磷酸化细胞外信号调节激酶1/2、核因子κB(p65)活性的表达(P0.05),细胞外信号调节激酶1/2、核因子κB信号通路被特异性阻断后泡沫细胞内胆固醇含量降低(P0.05);血管紧张素(1-7)联用细胞外信号调节激酶1/2、核因子κB信号通路的特异性阻断剂后泡沫细胞内胆固醇含量显著降低(P0.01);核因子κB信号通路被阻断后核因子κB(p65)活性表达显著降低(P0.01),而磷酸化细胞外信号调节激酶1/2活性表达无明显降低(P0.05),细胞外信号调节激酶1/2信号通路被阻断后磷酸化细胞外信号调节激酶1/2和核因子κB(p65)活性表达均降低(P0.05)。结论血管紧张素(1-7)可能通过降低磷酸化细胞外信号调节激酶1/2、核因子κB(p65)的活性,减少细胞内胆固醇的蓄积;细胞外信号调节激酶1/2、核因子κB信号通路被特异性阻断后可减少泡沫细胞内胆固醇的含量;细胞外信号调节激酶可能是核因子κB(p65)信号通路的上游信号。     

高血压病人小动脉中磷酸化细胞外信号调节激酶1/2及ets样基因1的蛋白表达

目的 研究细胞外信号调节激酶系统(ERK)及其下游底物ets样基因1(Elk-1)在原发性高血压中的作用.方法 采用免疫组织化学方法,对比观察高血压和非高血压病人胃肠小动脉血管平滑肌细胞及内皮细胞中细胞外信号调节激酶(ERK1/2)和ets样基因1(Elk-1)的磷酸化情况.结果 高血压组胃肠小动脉血管平滑肌细胞中磷酸化ERK1/2染色阳性率(8.31%)明显高于非高血压组(0.53%),P＜0.05;高血压组内皮细胞中磷酸化ERK1/2的阳性率(4.97%)明显高于非高血压组(P＜0.05).高血压组胃肠小动脉血管平滑肌细胞中磷酸化Elk-1染色阳性率(3.53%)明显高于非高血压组(0.27%),P＜0.05.在血管平滑肌细胞、血管内皮细胞中磷酸化ERK1/2与磷酸化Elk-1的表达均有正相关关系.结论 原发性高血压患者的胃肠细小动脉血管平滑肌细胞以及内皮细胞中细胞外信号调节激酶及其下游底物Elk-1的磷酸化增加.     

沥水调脂胶囊对轻度修饰低密度脂蛋白诱导血管平滑肌细胞丝裂原活化蛋白激酶信号转导的影响

轻度修饰低密度脂蛋白 ;　血管平滑肌细胞[摘　要 ]　为了探讨健脾祛痰化瘀方———沥水调脂胶囊对轻度修饰低密度脂蛋白诱导的血管平滑肌细胞丝裂原活化蛋白激酶信号转导的影响 ,采用血清药理学通法制备含药血清 ,以甲醇除蛋白预处理 ;以Cu2 + 氧化制备轻度修饰低密度脂蛋白 ;用磷酸化抗体以WesternBlot方法分析c junN端激酶 1、细胞外信号调节激酶 1和 2的磷酸化。结果发现 ,2 0 %含药血清可明显降低 0 .5h和 1h轻度修饰低密度脂蛋白诱导的c junN端激酶 1磷酸化 (P <0 .0 5 ) ,而对细胞外信号调节激酶 1和 2无明显影响。结果提示 ,降低c junN端激酶 应激活化蛋白激酶信号可能是沥水调脂胶囊抑制血管平滑肌细胞增殖的机制之一。     

高血压病人小动脉中磷酸化细胞外信号调节激酶1/2及ets样基因1的蛋白表达

目的研究细胞外信号调节激酶系统（ERK）及其下游底物ets样基因1（E1k-1）在原发性高血压中的作用。方法采用免疫组织化学方法，对比观察高血压和非高血压病人胃肠小动脉血管平滑肌细胞及内皮细胞中细胞外信号调节激酶（ERK1／2）和ets样基因1（E1k-1）的磷酸化情况。结果高血压组胃肠小动脉血管平滑肌细胞中磷酸化ERK1／2染色阳性率（8．31％）明显高于非高血压组（0．53％），P〈0．05；高血压组内皮细胞中磷酸化ERK1／2的阳性率（4．97％）明显高于非高血压组（P〈0．05）。高血压组胃肠小动脉血管平滑肌细胞中磷酸化Elk-1染色阳性率（3．53％）明显高于非高血压组（0．27％），P〈0．05。在血管平滑肌细胞、血管内皮细胞中磷酸化ERK1／2与磷酸化E1k-1的表达均有正相关关系。结论原发性高血压患者的胃肠细小动脉血管平滑肌细胞以及内皮细胞中细胞外信号调节激酶及其下游底物Elk-1的磷酸化增加。     

KATP通道与人肺动脉平滑肌细胞外信号调节激酶磷酸化的关系

目的 研究三磷酸腺苷(ATP)敏感性钾(KATP)通道与人肺动脉平滑肌细胞外信号调节激酶1和2(ERK1/2)磷酸化的关系.方法 原代培养人肺动脉平滑肌细胞,用Western-blot方法 检测磷酸化细胞外信号调节激酶1和2(p-ERK1/2).对照组不予干预,实验组分别加入内皮素-1(ET-1)、ET-1+埃他卡林、吡那地尔或格列本脲等孵育.结果 ①在2～30 min,ET-1呈时间依赖性促进人肺动脉平滑肌细胞ERK1/2磷酸化,10 min时最明显.②埃他卡林和吡那地尔可拮抗ET-1对ERK1/2磷酸化的影响.③特异性KATP通道阻断剂格列本脲可逆转埃他卡林和吡那地尔的作用.结论 KATP通道开放剂可能通过激活KATP通道,抑制ET-1诱导的原代培养人肺动脉平滑肌细胞ERK1/2磷酸化,KATP通道可能是研发新型治疗肺动脉高压药物的重要靶分子.     

血管平滑肌细胞分泌氧化应激诱导因子的纯化与确定

活性氧通过促进血管平滑肌细胞 (VSMC)增殖已被认为是动脉粥样硬化和高血压的病因之一。我们以前的实验显示 ,超氧阴离子生成剂LY835 83激活VSMC细胞外信号调节激酶 (ERK1 2 ) ,并呈现出两个效应峰值特征。早期效应出现在LY835 83作用后 10min ,晚期效应出现在LY835 83作用后 2h。LY835 83通过激活ERK1 2诱导VSMC增殖。我们推测 ,LY835 83作用的第一相是其进入细胞后产生超氧阴离子所致 ,因为超氧阴离子产生抑制剂Tiron只取消LY835 83的第一相作用 ;而第二相作用可能是由于LY835 83刺激VSMC释放ERK1 2激活因子所为。我们将这种因子命名为氧化应激诱导因子 (secretedoxida tivestress -inducedfactors,SOXF)。为了证实此一假设 ,我们采用SPSepharose、HeparinSepharose、PhenylSepharose、GelFiltration等一系列亲合层析和凝胶过滤技术 ,以分离获得的成分是否能激活ERK1 2为监测指标 ,从受LY835 83刺激 2h的VSMC条件培养基中分离出SOXF蛋白。然后通过毛细管色谱 (CCG)技术和ElectrosprayIonizationTandemMassSpectrometry技术分析发现热休克蛋白 90 -a (HSP90 -a)和CyclophilinB是主要的SOXF。免疫印迹分析发现 ,VSMC受LY835 83刺激后特异地分泌HSP90-a,而不是HSP90 -b。随后的实验发现 ,条件培养基中的H     

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.     

Angiographic diagnosis of the degree of serosal invasion of carcinoma of the colon

Angiography using Prostaglandin El^® was performed on 38 patients with carcinoma of the colon in order to diagnose the degree of serosal cancer invasion. The findings at angiography were classified into four groups:1) AG-S3, abnormal change (irregularity and/or encasement) up to marginal vessels; 2) AG-S2, abnormality up to vasa recta; 3) AG-S1, abnormality of penetrating branches of vasa recta within the wall of the colon; and 4) AG-S0, no distinct findings of abovementioned vessels. These angiographic findings were compared with both macroscopic and microscopic serosal cancer invasion. Angiographic diagnosis is in accord with the macroscopic findings in 84.2 percent of cases. Angiographic diagnosis is in accord with the microscopic findings in 32.4 percent of cases. Macroscopic findings confirm the angiographic diagnosis precisely but the conflict with microscopic findings should not be overlooked. This may be the result of inflammatory change, adhesion, and fibrosis around carcinoma of the colon.