阿托伐他汀对系膜增殖性肾炎大鼠平滑肌肌动蛋白和转化生长因子β1表达的影响

目的观察阿托伐他汀对系膜增殖性肾炎大鼠24h尿蛋白、肾组织平滑肌肌动蛋白(α-SMA)和转化生长因子β1(TGF-β1)表达的影响,探讨其肾脏保护作用的机制。方法采用抗胸腺细胞血清诱发的系膜增殖性肾炎大鼠模型,将SD大鼠随机分为正常对照组、肾炎模型组、小剂量阿托伐他汀治疗组(8mg/kg·d)和大剂量阿托伐他汀治疗组(16mg/kg·d,n=8),每组块大鼠治疗12d后,检测各组大鼠血总胆固醇、甘油三酯、血肌酐(Scr)和24h尿蛋白,以及肾组织α-SMA和TGF-β1的表达。结果阿托伐他治疗组大鼠24h尿蛋白、肾小球α-SMA及肾组织TGF-β1mRNA的表达明显下降,肾组织病理改变明显改善,与模型组相比有显著性差异(P<0·05),且呈剂量依赖关系。其中肾炎模型组尿蛋白(30·34±0·62)mg/d,阿托伐他汀小剂量治疗组(21·17±0·79)mg/d,大剂量治疗组(9·77±0·54)mg/d。同时,各组血脂水平无明显差异(P>0·05)。结论阿托伐他汀可显著改善系膜增殖性肾炎大鼠肾脏病变,抑制系膜细胞的增生,减少系膜基质的蓄积,其机制可能与抑制TGF-β1的表达有关。     

阿托伐他汀对系膜增殖性肾炎大鼠平滑肌肌动蛋白和转化生长因子β1表达的影响

目的观察阿托伐他汀对系膜增殖性肾炎大鼠24 h尿蛋白、肾组织平滑肌肌动蛋白(α-SMA)和转化生长因子β1(TGF-β1)表达的影响,探讨其肾脏保护作用的机制.方法采用抗胸腺细胞血清诱发的系膜增殖性肾炎大鼠模型,将SD大鼠随机分为正常对照组、肾炎模型组、小剂量阿托伐他汀治疗组(8 mg/kg·d)和大剂量阿托伐他汀治疗组(16 mg/kg·d, n=8),每组块大鼠治疗12 d后,检测各组大鼠血总胆固醇、甘油三酯、血肌酐(Scr)和24 h尿蛋白, 以及肾组织α-SMA和TGF-β1的表达.结果阿托伐他治疗组大鼠24 h尿蛋白、肾小球α-SMA及肾组织TGF-β1mRNA的表达明显下降,肾组织病理改变明显改善,与模型组相比有显著性差异(P<0.05),且呈剂量依赖关系.其中肾炎模型组尿蛋白(30.34±0.62)mg/d,阿托伐他汀小剂量治疗组(21.17±0.79)mg/d,大剂量治疗组(9.77±0.54)mg/d.同时,各组血脂水平无明显差异(P>0.05).结论阿托伐他汀可显著改善系膜增殖性肾炎大鼠肾脏病变,抑制系膜细胞的增生,减少系膜基质的蓄积,其机制可能与抑制TGF-β1的表达有关.     

阿托伐他汀对单侧输尿管梗阻大鼠肾组织Wnt4/β-catenin信号通路的干预作用

目的探讨阿托伐他汀对单侧输尿管梗阻(UUO)大鼠肾组织Wnt4/β-catenin信号通路的干预作用。方法 36只SD大鼠,随机分为假手术组、模型组和阿托伐他汀组,各组分别设7 d、14 d两个时间点。HE、Masson、PAS染色法观察肾脏病理改变;免疫组化观察Wnt4和β-catenin蛋白在肾组织的表达;Western印迹检测各组大鼠肾皮质Wnt4、β-catenin、GSK-3β、p-GSK-3β、Ecadherin、α-SMA和CollagenⅠ蛋白的相对表达量。结果与假手术组相比,模型组肾皮质Wnt4和β-catenin、p-GSK-3β、α-SMA蛋白表达显著增多(P<0.05),CollagenⅠ沉积增多(P<0.01),E-cadherin蛋白表达显著减少(P<0.01),GSK-3β在各组大鼠肾组织表达无差异;与模型组相比,阿托伐他汀组肾组织Wnt4、β-catenin、p-GSK-3β和α-SMA蛋白表达减少(P<0.05),CollagenⅠ蛋白沉积显著减少(P<0.05),并伴有E-cadherin蛋白表达显著增多(P<0.05),而GSK-3β蛋白表达无明显变化(P>0.05)。结论 Wnt4/β-catenin信号通路的活化促进了UUO大鼠肾脏纤维化的发生发展,阿托伐他汀能改善肾脏纤维化病变,减轻肾间质细胞外基质的沉积,可能与其抑制Wnt4/β-catenin信号通路的激活和传导有关。     

西罗莫司联用阿托伐他汀对大鼠血管平滑肌细胞氧化应激损伤和一氧化氮合酶的影响

目的探讨西罗莫司和阿托伐他汀联合使用对大鼠血管平滑肌细胞氧化应激损伤和一氧化氮合酶(NOS)的影响。方法取大鼠血管平滑肌细胞进行实验,分为空白组、DMSO组、西罗莫司组(100nmol/L)、阿托伐他汀组(3μmol/L)和联合组(西罗莫司100nmol/L加阿托伐他汀3μmol/L)。实验各组细胞给予相应药物干预2h后,加入三丁基过氧化氢诱导氧化应激损伤,24h后检测各项指标。结果与空白组比较,DMSO组、西罗莫司组、阿托伐他汀组和联合组细胞增殖率明显下降(P<0.01)。与空白组和DMSO组比较,阿托伐他汀组和联合组超氧化物歧化酶水平明显上升和丙二醛水平明显下降(P<0.05,P<0.01)。与空白组、DMSO组、西罗莫司组比较,阿托伐他汀组和联合组诱导型一氧化氮合酶(iNOS)mRNA和蛋白表达明显下降(P<0.01);联合组iNOS mRNA和蛋白表达较阿托伐他汀组明显下降(P<0.05,P<0.01)。结论在氧化应激状态下,西罗莫司和阿托伐他汀均能抑制大鼠血管平滑肌细胞增殖和抗氧化损伤,维持NOS系统平衡,联合应用的效果优于单独应用。     

氟伐他汀对动脉粥样硬化大鼠胸主动脉肾上腺髓质素受体表达的影响

目的探讨肾上腺髓质素受体（ADMR）在动脉粥样硬化（AS）大鼠胸主动脉病变时的变化及氟伐他汀对ADMR表达的影响。方法将SD大鼠随机分为3组:正常对照组、AS模型组和氟伐他汀干预组。采用喂养高脂饲料（正常饲料基础上加入30g/kg胆固醇、5g/kg胆酸钠、2g/kg丙基硫氧嘧啶、50g/kg精制糖、100g/kg猪油）加维生素D3制备AS动物模型,氟伐他汀20mg/（kg·d）灌胃12周。用RT-PCR和Western印记法分别检测各组胸主动脉中ADMR mRNA和蛋白的表达情况。结果氟伐他汀干预组大鼠与AS组比较,体质量差异无统计学意义;与AS组相比,干预组三酰甘油（TG）、总胆固醇（CHOL）显著下降（P<0.01）;与正常对照组相比,模型组TG、CHOL明显升高（P<0.05）;与正常对照组相比,模型组、干预组血钙均明显升高（P<0.05）。氟伐他汀干预组大鼠胸主动脉中ADMR mRNA及蛋白的表达均显著高于AS组（P<0.05）。结论氟伐他汀可上调AS大鼠胸主动脉ADMR基因和蛋白的表达,ADMR可能参与了氟伐他汀抗动脉粥样硬化的作用。     

阿托伐他汀对高血压大鼠心脏血管紧张素转换酶2表达的影响

目的 观察阿托伐他汀对两肾一夹高血压大鼠心脏血管紧张素转换酶2及心肌重构表达的影响,探讨阿托伐他汀改善心肌重构可能的新作用机制.方法 40只雄性Wistar大鼠随机分为5组,每组8只:假手术组、血管紧张素转换酶2高血压组、缬沙坦组、阿托伐他汀10 mg/(kg·d)组和阿托伐他汀30 mg/(kg·d)组.测定药物干预后血压变化及全心重量、左心室重量、左心室重量指数;免疫组织化学法检测心脏血管紧张素转换酶2蛋白表达;放射免疫法测定心肌组织血管紧张素Ⅱ水平;逆转录聚合酶链反应法检测心脏血管紧张素转换酶2 mRNA表达.结果 (1)高剂量阿托伐他汀组较高血压组血压降低显著(P<0.01).(2)药物干预后高剂量阿托伐他汀组全心重量、左心室重量、左心室重量指数低于高血压组(P<0.05).(3)高剂量阿托伐他汀组较高血压组降低心肌组织血管紧张素Ⅱ浓度显著(P<0.01).(4)缬沙坦组、阿托伐他汀组心脏血管紧张素转换酶2蛋白表达较高血压组增强.(5)逆转录聚合酶链反应显示各组大鼠心脏组织中均有血管紧张素转换酶2 mRNA的表达,缬沙坦组,低剂量、高剂量阿托伐他汀组较高血压组不同程度增高(P<0.05).结论 阿托伐他汀在降低血压的同时,具有改善心肌重构作用,其可能是通过降低心肌组织血管紧张素Ⅱ浓度,增加心脏组织血管紧张素转换酶2蛋白表达,增加心脏组织血管紧张素转换酶2 mRNA表达来实现的.     

阿托伐他汀逆转腹主动脉缩窄型高血压大鼠心肌重构的机制

目的 观察阿托伐他汀对腹主动脉缩窄型高血压大鼠血清血管紧张素(1-7)浓度及左心室肥厚心肌组织中p-ERK1/2表达水平的影响,探讨阿托伐他汀逆转心肌重构的可能机制.方法 50只SD雄性大鼠随机分为5组:假手术组、模型组、10 mg/(kg·d)阿托伐他汀组、30 mg/(kg·d)阿托伐他汀组及缬沙坦组,每组10只.术后第1天,将阿托伐他汀研磨成粉,溶于少量蒸馏水中制成悬液,采用灌胃法给药;假手术组和模型组大鼠均用等量生理盐水灌胃.每日上午定时一次,共4周.鼠尾容积法测定药物干预前及干预后2周、4周的血压变化.4周后处死大鼠,测定大鼠体重、左心室重量、左心室重量指数;HE染色检测心肌细胞平均直径;酶联免疫吸附法测定血清血管紧张素(1-7)浓度;免疫印迹法检测心肌p-ERK1/2蛋白表达水平.结果 30 mg/(kg·d)阿托伐他汀组和10 mg/(kg·d)阿托伐他汀组收缩压明显低于模型组(P<0.01),30 mg/(kg·d)阿托伐他汀组收缩压明显低于10mg/(kg·d)阿托伐他汀组(P<0.01),缬沙坦组收缩压明显低于30 mg/(kg·d)阿托伐他汀组和10 ms/(kg·d)阿托伐他汀组(P<0.01);假手术组、30 mg/(kg·d)阿托伐他汀组、10 mg/(kg·d)阿托伐他汀组及缬沙坦组左心室重量指数明显低于模型组(P<0.01),30 mg/(kg·d)阿托伐他汀组左心室重量指数明显低于10 mg/(kg·d)阿托伐他汀组(P<0.05);假手术组、30 mg/(kg·d)阿托伐他汀组及缬沙坦组心肌细胞平均直径明显低于模型组(P<0.01).10 mg(kg·d)阿托伐他汀组与模型组无差异(P>0.05);10 mg/(kg·d)阿托伐他汀组、30 mg/(kg·d)阿托伐他汀组及缬沙坦组血清Ang-(1-7)浓度显著高于模型组(P<0.01),30 mg/(kg·d)阿托伐他汀组及缬沙坦组血清Ang.(1-7)浓度明显高于10 mg/(kg·d)阿托伐他汀组(P<0.05);10 mg/(kg·d)阿托伐他汀组、30mg/(kg·d)阿托伐他汀组及缬沙坦组p-ERK1/2蛋白表达水平显著低于模型组(P<0.01),但高于假手术组.结论 阿托伐他汀对腹主动脉缩窄型高血压大鼠心肌重构具有逆转作用,其机制与降低压力负荷诱导的心肌肥厚组织中p-ERK1/2 蛋白表述水平有关.     

阿托伐他汀对脂多糖诱导的人脐静脉内皮细胞肝X受体α及其靶基因表达的影响

目的研究阿托伐他汀对炎症刺激物脂多糖干预后人脐静脉内皮细胞中肝X受体α及其靶基因腺苷三磷酸结合盒转运体A1、固醇调节元件结合蛋白1表达的影响。方法体外培养人脐静脉内皮细胞,进行以下干预实验:对照组加入2μL磷酸盐缓冲液;脂多糖干预组用终浓度为100μg/L脂多糖溶液干预细胞24 h;(2)对照干预组和阿托伐他汀干预组先用二甲基亚砜或不同浓度(0.1、1.0及10.0μmol/L)的阿托伐他汀预干预2 h,然后加入100μg/L脂多糖溶液共同干预22 h。用实时定量聚合酶链反应测定肝X受体α及其靶基因腺苷三磷酸结合盒转运子A1、固醇调节元件结合蛋白1的mRNA表达量。结果与对照组相比,脂多糖干预组肝X受体α及其靶基因mRNA表达明显受到抑制(P<0.05);与对照干预组相比,阿托伐他汀干预组随给药浓度增加肝X受体α及其靶基因mRNA表达逐步升高(P<0.05)。结论脂多糖可明显抑制人脐静脉内皮细胞中肝X受体α及其靶基因表达;阿托伐他汀在一定范围内可呈剂量依赖性上调肝X受体α及其靶基因表达,提示其抗动脉粥样硬化作用可能部分通过肝X受体信号通路发挥作用。     

阿托伐他汀预处理对脑缺血再灌注大鼠基质金属蛋白酶9表达的影响

目的观察阿托伐他汀对大鼠脑缺血再灌注后基质金属蛋白酶9(MMP-9)表达的影响。方法选择SD大鼠96只,随机分为:假手术组16只,脑缺血再灌注组40只,阿托伐他汀组40只。建立大脑中动脉缺血2h再灌注模型。阿托伐他汀组在建立模型前21d予以阿托伐他汀灌胃。假手术组分为24h和48h,每个时间点8只。缺血再灌注组和阿托伐他汀组根据缺血再灌注时间分为3、12、24、48、96h,每个时间点8只。于各个时间点进行神经行为学测试;TTC染色测定缺血体积;免疫组织化学SABC法测定MMP-9蛋白的表达变化;RT-PCR法对各组脑组织中MMP-9mRNA表达进行分析。结果与缺血再灌注组比较,阿托伐他汀组3、12、24、48、96h神经功能评分明显降低,梗死体积明显减小[(102.37±10.31)mm3 vs(135.26±12.16)mm3,(105.78±9.23)mm3 vs(155.07±14.12)mm3,(110.56±13.45)mm3 vs(162.47±11.41)mm3,(119.71±10.01)mm3 vs(180.27±14.27)mm3,(121.63±11.23)mm3 vs(193.41±11.56)mm3,P<0.05];12、24、48、96h MMP-9蛋白、mRNA表达显著降低,差异有统计学意义(P<0.05)。结论脑卒中前预服用阿托伐他汀可能通过降低MMP-9水平来达到脑保护的效果。     

阿托伐他汀对培养的兔脂肪细胞凝血和纤溶因子的影响及其机制

目的:观察阿托伐他汀对培养的兔脂肪细胞表达组织因子(TF,凝血因子Ⅲ)、I型纤溶酶原激活物抑制剂(PAI1)的影响,并探讨其可能的作用机制。方法:取正常兔(n=4)脂肪组织分离培养脂肪细胞,实验分3组:空白对照组、阿托伐他汀干预组和甲羟戊酸加阿托伐他汀干预组,后两组分别设有不同浓度,以阿托伐他汀或甲羟戊酸孵育兔脂肪细胞24小时后收集细胞。逆转录聚合酶链反应测定脂肪细胞TF和PAI1信使核糖核酸(mRNA)表达。用酶联免疫吸附法测定TF和PAI1蛋白浓度。结果:阿托伐他汀干预组随着阿托伐他汀浓度的增加,TF和PAI1蛋白水平逐渐下降,在阿托伐他汀浓度为10μmol/L时,其抑制作用最大,脂肪细胞TF、PAI1蛋白水平较空白对照组有极显著性差异(P<0.01)。甲羟戊酸加阿托伐他汀干预组加入1μmol/L甲羟戊酸后阿托伐他汀对脂肪细胞TF、PAI1mRNA表达的抑制作用可以被甲羟戊酸逆转,与空白对照组比较,有极显著性差异(P<0.01);加入100μmol/L的甲羟戊酸几乎完全逆转了阿托伐他汀对脂肪细胞TF、PAI1mRNA表达的抑制作用。结论:阿托伐他汀能抑制兔脂肪细胞TF、PAI1mRNA和蛋白表达,其机制可能是通过甲羟戊酸代谢途径实现的。     

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.     

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.     

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.     

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。     

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.     

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.