糖尿病大鼠肾脏局部α3、β1整合素与血管紧张素Ⅱ水平的相关性研究

目的探讨糖尿病大鼠肾脏局部α3、β1整合素与血管紧张素Ⅱ(ATⅡ)的相关性及ATⅡ1型受体(AT1)拮抗剂对其的影响。方法 40只雄性Wistar大鼠随机分为正常对照组(NC)、糖尿病组(DM)、糖尿病肼屈嗪干预组(Hyd)、糖尿病厄贝沙坦干预组(Irb),每组各10只。肼屈嗪及厄贝沙坦干预8周后进行PAS染色,观察肾脏病理变化。免疫组织化学法检测肾小球足细胞密度,ELISA及RTPCR检测肾脏局部ATⅡ水平、UAER、肾脏α3/β1整合素mRNA的表达。结果 (1)与NC组比较,DM组肾小球足细胞密度下降、蛋白尿增加、α3及β1整合素mRNA的表达下降、ATⅡ升高(P0.05)。予肼屈嗪及厄贝沙坦干预后,上述指标改善(P0.05)。(2)除外血压影响,与Hyd组比较,Irb组蛋白尿下降,足细胞密度升高(P0.05);ATⅡ下降(P0.05);α3及β1整合素mRNA的表达进一步改善(P0.05)。(3)肾小球足细胞密度与肾皮质α3、β1整合素mRNA表达呈正相关(rα3=0.883,rβ1=0.853,P0.01);α3及β1整合素mRNA的表达与ATⅡ呈负相关(rα3=-0.527,rβ1=-0.421,P0.01)。结论糖尿病大鼠肾脏局部α3、β1整合素表达变化与ATⅡ水平相关,可能是AT1拮抗剂除降压外,对糖尿病大鼠肾脏的保护机制之一。     

普罗布考、厄贝沙坦对自发性高血压大鼠糖代谢及血清脂联素的影响

目的 探讨抗氧化剂普罗布考、血管紧张素Ⅱ1型受体拮抗剂(AT1 R)厄贝沙坦对自发性高血压大鼠(SHR)胰岛素抵抗及血清脂联素的影响.方法 SHR 40只随机分为4组,对照组(n=10)、普罗布考组[61 mg/(kg·d),n=10]、厄贝沙坦组[50mg/(kg·d),n=10]、联合用药组(普罗布考十厄贝沙坦,n...     

雷公藤多甙联合厄贝沙坦对糖尿病肾病患者尿足细胞排泄影响及机制探讨

目的 观察雷公藤多甙(TwHF)联合厄贝沙坦对糖尿病肾病(DKD)患者尿足细胞的影响,探讨TwHF对DKD患者肾脏保护作用的机制.方法 前瞻性入选45例2型糖尿病肾病患者,分为3组,TwHF治疗组(DT,15例)、厄贝沙坦治疗组(DI,15例)及联合治疗组(DTI,15例).经6周洗脱期后分别给予TwHF(1～2 mg· kg-1·d-1)、厄贝沙坦(150 ～ 300 mg/d)和TwHF联合厄贝沙坦(厄贝沙坦150～300 mg/d加TwHF 1 ～2 mg·kg-1·d-1)干预12周.15例健康志愿者作为正常对照.采用间接免疫荧光法检测单克隆抗体podocalyxin标记的尿足细胞.双抗体夹心酶联免疫吸附法测定尿结缔组织生长因子(CTGF)、骨桥蛋白(OPN)和转化生长因子β1(TGFβ1).结果 2型糖尿病肾病患者尿脱落足细胞较对照组明显增多(P＜0.01),DKD患者尿中脱落的足细胞检出率为86.6％.尿足细胞阳性DKD患者尿CTGF、OPN及TGFβ1表达明显高于阴性尿足细胞者(P ＜0.05或0.01).相关分析表明尿蛋白量与尿足细胞的排泄计数明显相关(r=0.79,P＜0.01);尿足细胞的排泄计数与尿CTGF、OPN及TGFβ1表达水平明显相关(r=0.56、0.41、0.44,P值均＜0.01).应用TwHF、厄贝沙坦及两者联合干预12周后,尿蛋白及尿足细胞排泄较治疗前均明显减少(P值均＜0.01).各治疗组尿CTGF、OPN、TGFβ1表达较治疗前均明显降低(P值均＜0.01),且以联合组变化最明显(P＜0.05).结论 尿脱落足细胞可能是预测DKD进展的有效因子.TwHF对DKD患者尿足细胞有重要的保护作用,其机制可能与抑制CTGF、OPN及TGFβ1表达有关,TwHF联合厄贝沙坦对DKD患者足细胞保护具有协同作用.     

厄贝沙坦治疗2型糖尿病伴白蛋白尿患者有效性和安全性——多中心随机双盲对照研究

目的 评估厄贝沙坦治疗2型糖尿病伴白蛋白尿患者的疗效与安全性.方法 采用随机、双盲、安慰剂对照、多中心临床研究方法,8个医院326例受试者随机分配到厄贝沙坦(300 mg/d)组(160例)或安慰剂组(166例),治疗24周.检测尿白蛋白排泄率(UAER)、收缩压、舒张压、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇(LDL-C)和HhA1C水平.结果 厄贝沙坦组UAER与基线相比显著下降(P＜0.01),安慰剂组无明显变化(P＞0.05),两组差异有统计学意义(P＜0.01).在意向治疗(ITT)人群高血压和非高血压患者的收缩压、舒张压均有不同程度下降(P＜0.01),而在符合方案(PP)人群却无明显下降.治疗24周后,厄贝沙坦组的LDL-C水平明显低于安慰剂组(P＜0.01).治疗期间厄贝沙坦组低血压的发生率高于安慰剂组,个别患者出现血钾升高.结论 厄贝沙坦300 mg/d可以有效降低2型糖尿病伴白蛋白尿患者的UAER,其疗效独立于降血压作用之外,并且具有良好的安全性和耐受性.     

雷公藤多甙联合厄贝沙坦对糖尿病肾病大鼠足细胞nephrin和podocin表达的影响

目的 观察雷公藤多甙联合厄贝沙坦对糖尿病肾病大鼠足细胞nephrin和podocinmRNA和蛋白表达的影响.方法 将体重200 ～ 260 g的50只SD大鼠按随机数字表法分为正常对照组和4个模型组（n=10）,后者分别应用链脲佐菌素造模成功后分为糖尿病肾病组（DN组）、厄贝沙坦组、雷公藤多甙组和雷公藤多甙联合厄贝沙坦组.给予相应干预8周后,检测血尿指标,HE染色观察肾组织病理变化,逆转录-多聚酶链反应（RT-PCR）法检测各组大鼠肾皮质中nephrin和podocinmRNA和蛋白表达.结果 （1）与DN组大鼠比较,雷公藤多甙联合厄贝沙坦组大鼠肾皮质nephrin mRNA （0.507±0.024比0.276 ±0.015,P ＜0.01）和podocin mRNA （0.533±0.024比0.463±0.022,P＜0.01）表达上调.（2）与DN组大鼠比较,雷公藤多甙联合厄贝沙坦组大鼠肾皮质nephrin蛋白（0.738±0.029比0.199±0.012,P＜0.01）和podocin蛋白（0.811 ±0.032比0.227±0.014,P＜0.01）表达上调.（3） HE染色和Masson染色显示,糖尿病组大鼠肾脏肾小球体积增大,系膜基质弥漫增多,系膜细胞明显增多,基底膜弥漫增厚,间质可见灶性淋巴细胞及单核细胞浸润,厄贝沙坦组和雷公藤多甙组病变较糖尿病组减轻,雷公藤多甙联合厄贝沙坦组大鼠肾脏组织病变较厄贝沙坦组和雷公藤多甙组进一步减轻.结论 雷公藤多甙联合厄贝沙坦对糖尿病大鼠的肾脏足细胞具有保护作用,这种保护作用可能是通过上调足细胞nephrin和podocin mRNA和蛋白表达有关.     

糖尿病大鼠肾脏8-羟基脱氧鸟苷和超氧化物歧化酶表达的变化及西格列汀对其影响的研究

目的 探讨西格列汀对糖尿病大鼠肾脏8-羟基脱氧鸟苷(8-OHdG)和血清超氧化物歧化酶(SOD)表达的影响. 方法 复制糖尿病大鼠模型,随机分为西格列汀1 mg/(kg·d)干预组(Sita1,n=15),西格列汀10mg/(kg·d)干预组(Sita2,n=15),糖尿病未干预组(DM,n=16)及正常对照组(NC,n=15).14周末观察各组FPG、FIns、肾功能、SOD 24 hUAlb、尿8-OHdG的变化. 结果 与NC组比较,DM、Sita1和Sita2组FIns及血清SOD活性均下降(P＜0.05),FPG、BUN、血肌酐(Scr)、24 hUAlb及尿8-OHdG均升高(P＜0.05).与DM组比较,Sita1组BUN、Scr、24 hUAlb及尿8-OHdG均降低(P＜0.05),血清SOD活性升高(P＜0.05);与DM组比较,Sita2组FPG、BUN、Scr、24 hUAlb及24h尿8-OHdG降低(P＜0.05),FIns和血清SOD活性升高(P＜0.05). 结论 氧化应激参与糖尿病大鼠肾脏病变的发生发展,西格列汀对糖尿病大鼠肾脏有一定的保护作用.     

解聚复肾宁对糖尿病大鼠肾脏的保护作用

目的 观察中药复方解聚复肾宁(JJFSN)对糖尿病 (DM)大鼠肾脏的保护作用.方法 建立链脲佐菌素(STZ)诱导的DM大鼠模型,将成模大鼠随机分成4组:模型组、JJFSN组、厄贝沙坦组、JJFSN+厄贝沙坦组,并设正常对照组.各组大鼠采用相应的干预措施处理12 w.常规方法检测各组大鼠尿白蛋白排泄率(UAER)等指标,免疫组化法检测肾血管内皮生长因子(VEGF)和骨形成蛋白7(BMP-7)表达,Western印迹检测肾组织血小板衍化生长因子B(PDGF-B)的表达,透射电镜观察肾脏超微结构.结果 模型组大鼠除肾BMP-7表达显著减少外,其余指标均显著增高,肾脏超微结构改变明显;JJFSN组、厄贝沙坦组和JJFSN+厄贝沙坦组除肾BMP-7显著高于模型组(P＜0.05)外,其余指标均显著低于模型组(P＜0.05),肾脏超微结构改变明显改善;JJFSN+厄贝沙坦组各项指标改善明显优于模型组、JJFSN组和厄贝沙坦组(P＜0.05),但未达到正常对照组水平.结论 JJFSN对DM大鼠肾脏有明显保护作用.     

黄芪对高血压大鼠肾脏血管紧张素转换酶2表达的影响

目的 探讨两肾一夹(2K1C)高血压大鼠肾脏血管紧张素转换酶2(ACE2)表达.了解甘肃黄芪对大鼠肾脏ACE2 mRNA表达及血浆血管紧张素Ⅱ(AngⅡ)的影响,观察黄芪的降压效果.方法 50只雄性Wistar大鼠随机分为5组:正常对照组(n=10);2K1C高血压组(n=10);2K1C 缬沙坦组(n=10);2K1C 黄芪20 g/(kg·d)组(n=10);2K1C 黄芪10 g/(kg·d)组(n=10).8周后,用RT-PCR法检测肾脏ACE2 mRNA表达,免疫组化法检测肾脏ACE2表达,放射免疫分析法测定肾脏局部AngⅡ水平.结果 2K1C高血压大鼠肾脏ACE2 mRNA表达较正常大鼠降低(0.282±0.025 vs 0.359±0.017,P＜0.05),高、低剂量黄芪及缬沙坦治疗大鼠ACE2 mmRNA表达(0.398±0.004,0.391±0.006,0.403±0.009)均高于对照组(0.282±0.025)(P＜0.05).高剂量黄芪组降低肾脏局部AngⅡ效果较缬沙坦组明显(P＜0.01).缬沙坦和黄芪治疗都明显降低血压(P＜0.01).结论 2K1C高血压大鼠肾脏组织中ACE2 mRNA表达降低.甘肃黄芪及缬沙坦在降压的同时增加肾脏组织ACE2 mRNA表达.     

药物联合治疗对改善肾血管性高血压大鼠左室重构的对比研究

目的 通过贝那普利分别和比索洛尔、替米沙坦、氨氯地平联合应用治疗肾血管性高血压大鼠,观察并对比各组药物联合治疗的降压效果,并探讨其对左室重构的作用. 方法 两肾一夹法建立高血压大鼠模型,54只SD大鼠随机分为:假手术组(A组,n=10);高血压组(B组,n=11);β受体阻滞剂+血管紧张素转换酶抑制剂(ACEI)组(C组,n=11) 予以比索洛尔 5 mg/(kg·d)及贝那普利 5 mg/(kg·d)灌胃;ACEI+血管紧张素Ⅱ受体拮抗剂(ARB)组 ·d)及替米沙坦 10 mg/(kg·d)灌胃;ACEI+钙通道拮抗剂组(E组,n=11) =11)予以贝那普利 5 mg/(kg(D组,n予以贝那普利 5 mg/(kg·d)及氨氯地平 2.5 mg/(kg·d)灌胃;饲养20周,期间每2周给大鼠测量鼠尾动脉压和超声心动图;20周后采集标本,用免疫组化法检测胶原Ⅲ、胶原Ⅳ及心钠素(ANF). 结果 各用药组降压明显,其中E组与A组血压相近,且比其他用药组血压降低更明显(P＜0.05).与A组比较,C组LVMI 明显上升 (P＜0.05);D组和E组无显著变化,但B组收缩末期左室内径(LVESD) 和舒张末期左室内径(LVEDD)明显扩大,与A组相比具有统计学差异(P＜0.05);且B组舒张末期左室后壁厚度(LVPWD)和收缩末期左室后壁厚度(LVPWS)明显变薄(P＜0.05),相对室壁厚度(RWT)明显下降(P＜0.05);C组LVPWD、LVPWS和RWT明显提高,与A组相比具有统计学差异(P＜0.05).C组胶原Ⅲ、胶原Ⅳ含量较B组降低 (P＜0.05),D组和E组亦显著降低(P＜0.01);与A组比较,B组胶原Ⅲ、胶原Ⅳ和ANF明显升高(P＜0.05);与B组比较, 各药物治疗组ANF显著降低(P＜0.01). 结论 在降压和靶器官保护方面,贝那普利和氨氯地平联用疗效最好.     

缬沙坦与硝苯地平对自发性高血压大鼠左心室肥厚心肌细胞G 蛋白偶联受体激酶2的表达及亚细胞分布的影响

目的 观察缬沙坦及硝苯地平对自发性高血压大鼠(SHR)左心室肥厚心肌细胞G 蛋白偶联受体激酶2(GRK2)的表达及亚细胞分布的影响.方法 选择自发性高血压大鼠(SHR)为研究对象(n=30),随机分为对照组(n=6),低剂量缬沙坦组[L 缬沙坦,10 mg /(kg·d),n=6],高剂量缬沙坦组[H缬沙坦,30 mg /(kg·d),n=6],低剂量硝苯地平组[L 硝苯地平,10 mg /kg,2 次/ d,n=6],高剂量硝苯地平组[H 硝苯地平,30mg /(kg·次),2 次/d,n=6],由6 月龄喂养至8月龄,处死后分离心脏,通过免疫荧光标记、激光共聚焦显微镜及Werstern Blot 等方法,观察左心室心肌细胞GRK2的表达及亚细胞分布的变化.结果 与对照组比较,两药物干预的SHR 左心室心肌细胞膜蛋白GRK2表达及分布减少,高剂量较低剂量又有进一步减少,差异均有统计学意义(均P＜0.05).缬沙坦组左心室心肌细胞膜蛋白GRK2表达及左心室重量较硝苯地平组减少,差异有统计学意义(P＜0.05).相关性分析结果示两药物干预组大鼠左心室心肌细胞膜蛋白GRK2透光密度与左心室重量呈正相关(缬沙坦组r＝0.837,硝苯地平组r＝0.829,均P＜0.01).结论 缬沙坦与硝苯地平改善左心室肥厚可能与抑制SHR 左心室心肌细胞膜蛋白GRK2表达有关,缬沙坦较硝苯地平能更好地改善心肌肥厚可能与其抑制GRK2表达使其进一步减少有关.     

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.