综合治理后燃煤污染型地方性氟中毒病区人群心电图观察

目的 观察综合治理后燃煤污染型地方性氟中毒(简称地氟病)病区人群心电图改变情况.方法 2011年,选择贵州省毕节市燃煤污染型地氟病病区人群,按病情轻重和综合治理时间长短分为4个组:轻病区+治理短组(沙地村52人)、轻病区+治理长组(下坝村58人)、重病区+治理短组(毛栗平村52人)、重病区+治理长组(中屯村60人),以贵阳市人群为非病区对照组(沙文新寨57人),采用同步导联心电图机测定观察人群心电图.结果 与非病区对照组[47.4％(27/57)]比较,重病区+治理短组[71.2％(37/52)]、重病区+治理长组[66.7％(40/60)]心电图异常率明显升高(x2值分别为6.346、4.448,P均＜0.05),而轻病区+治理短组[61.5％(32/52)]和轻病区+治理长组[56.9％(33/58)]未见明显改变(x2值分别为2.199、1.046,P均＞0.05);相同病区不同治理时间的人群心电图异常率比较,差异无统计学意义(轻、重病区x2值分别为0.244、0.261,P均＞0.05).结论 地氟病重病区人群心电图异常发生率较高,通过一定时间综合治理后地氟病病区人群心电图异常率降低不明显.     

血清骨钙素和骨保护素在燃煤型氟骨症患者中的表达

目的 观察血清骨钙素(BGP)、骨保护素(OPG)在燃煤型地方性氟中毒(简称地氟病)人群中的表达,为深入认识氟骨症发病机制以及评价和监测除氟效果提供基础依据.方法 选择贵州省6个燃煤型地氟病病区村居民作为观察对象,进行临床氟骨症检查,按病情分度分为正常、轻度、中度、重度4种,按不同分型分为正常、硬化型、疏松型、混合型4种,并根据氟骨症病情分度情况,将观察病区村分为轻、中、重病区村.分别用放射免疫法和酶联免疫法检测观察对象血清BGP、OPG.结果 重度氟骨症患者血清BGP[(6.78±4.43)μg/L]与正常[(3.58±1.53)μg/L],轻、中度患者[(3.44±2.66)、(3.41±2.20)μg/L]比较均明显增高(P<0.05);轻、中、重度患者血清OPG[(1251.55±998.31)、(1265.94±931.77)、(1560.55±858.07)ng/L]与正常[(520.81±385.05)ng/L]比较明显增高(P<0.05).混合型氟骨症患者血清BGP[(6.09±2.62)μg/L]与正常,硬化、疏松型患者[(3.97±1.53)、(3.20±2.12)μg/L]比较均明显增高(P<0.05);硬化、疏松、混合型氟骨症患者血清OPG[(1321.63±1017.00)、(1205.42±852.22)、(1529.01±402.83)ng/L]与正常比较明显增高(P<0.05).轻病区村人群血清OPG[(452.06±338.10)ng/L]与中、重病区村[(1266.30±899.14)、(1851.80±956.08)ng/L]比较明显降低(P<0.05),重病区村与中病区村比较则明显增高(P<0.05).结论 血清OPG可作为燃煤型氟中毒骨病变的一个早期生物学指标.重度氟骨症患者的骨代谢(骨再建)处于活跃状态,并随着氟中毒的严重程度加重而加重.     

氟伐他汀对颈动脉内膜增厚的治疗效果

目的:观察氟伐他汀预防颈动脉内膜中层厚度(CIMT)增厚的效果。方法:选择年龄45岁以上、低冠心病危险、CIMT增厚(1.2～3.5mm)、低密度脂蛋白胆固醇(LDL-C)浓度升高的540例患者,随机均分为安慰剂对照组和氟伐他汀组。观察两组治疗前后血脂水平变化以及最大CIMT变化率、CIMT进展情况等。结果:治疗两年后,与安慰剂对照组比较,氟伐他汀组总胆固醇[(6.18±0.13)mmol/L比(5.03±0.81)mmol/L]、甘油三酯[(2.45±0.72)mmol/L比(1.97±0.56)mmol/L]、LDL-C[(4.09±1.81)mmol/L比(2.95±1.10)mmol/L]水平均明显降低(P<0.05或<0.01),高密度脂蛋白胆固醇[(1.04±0.32)mmol/L比(1.25±0.30)mmol/L]水平明显升高,P<0.05;CIMT[(0.989±0.373)mm比(0.748±0.220)mm],CIMT进展率(0.0131mm/年比0.0014mm/年)明显减小(P<0.05,P<0.001)。结论:对于具有动脉硬化证据的中老年人,氟伐他汀能够显著降低低密度脂蛋白胆固醇水平,颈动脉内膜中层厚度及其进展率。     

肝X受体α、胆固醇调节元件结合蛋白1c介导脂质代谢紊乱在子痫前期中的作用及机制

目的研究子痫前期患者血清和胎盘中肝X受体α(LXRα)及其靶基因胆固醇调节元件结合蛋白1c(SREBP-1c)的表达与脂质代谢紊乱的关系及机制。方法入选子痫前期患者32例(轻度子痫前期15例和重度子痫前期17例)、正常妊娠30例和正常未孕30例。测定各组血脂水平,计算动脉硬化指数[动脉硬化指数=(总胆固醇-高密度脂蛋白胆固醇)/高密度脂蛋白胆固醇];酶联免疫吸附试验(ELISA)测定各组血清中LXRα及SREBP-1c蛋白水平;逆转录-聚合酶链反应(RT-PCR)及免疫组化技术(IHC)检测胎盘中氧化型低密度脂蛋白(oxLDL)、LXRα及SREBP-1c的mRNA和(或)蛋白表达水平。结果子痫前期组与正常妊娠组比较,总胆固醇[(6.78±1.56)比(5.20±0.96)mmol/L]、三酰甘油[(3.92±1.35)比(2.48±0.78)mmol/L]、极低密度脂蛋白胆固醇[(1.85±0.53)比(1.12±0.35)mmol/L]、低密度脂蛋白胆固醇[(4.31±1.23)比(3.01±0.55)mmol/L]、动脉硬化指数(3.10±1.22比1.88±0.74)增高,高密度脂蛋白胆固醇降低(P0.01或P0.05);正常妊娠组,轻、重度子痫前期组血清及胎盘中oxLDL、LXRα、SREBP-1c的mRNA和(或)蛋白的表达逐步升高(P0.01或P0.05)。相关分析显示,血清LXRα蛋白与血清SREBP-1c蛋白、总胆固醇、三酰甘油、动脉硬化指数呈正相关,与高密度脂蛋白胆固醇呈负相关。结论子痫前期患者血清及胎盘LXRα表达明显增强,促进其靶基因SREBP-1c的转录和翻译,介导母体及胎盘的脂质代谢紊乱。     

老年冠心病患者血浆非高密度脂蛋白胆固醇水平的差异

目的探讨在老年冠心病患者的血清非高密度脂蛋白胆固醇的差异。方法选择120例行冠状动脉造影检查的老年患者,冠状动脉造影前空腹采静脉血,分析冠状动脉造影阳性组和对照组之间非高密度脂蛋白胆固醇与其它血脂数据(总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白)差异的显著性及非高密度脂蛋白胆固醇对冠状动脉病变程度的相关性。结果冠状动脉造影阳性组非高密度脂蛋白胆固醇水平显著高于阴性组2.99±1.08mmol/L,一支病变组为3.41±0.59mmol/L,两支病变组为3.70±1.30mmol/L,三支病变组为3.77±1.10mmol/L,(P<0.001)并且非高密度脂蛋白的水平随冠状动脉病变支数逐渐增高,与冠状动脉狭窄分数相关(r=0.36,P<0.001);而两组间甘油三酯,高密度脂蛋白水平无统计学差异(P>0.05)。结论血清非高密度脂蛋白胆固醇对于老年人是一项简便实用的冠心病风险评估指标。     

冠心病与血脂异常的相关性(英文)

目的:研究冠心病与血脂异常的相关性。方法:选择冠脉造影检查确诊的冠心病患者302例(CHD组),门诊体检无心脑血管疾病的健康人群218例(健康对照组),收集所有研究对象相关资料,测定其血甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白-胆固醇(LDL)、高密度脂蛋白-胆固醇(HDL-C)含量,并进行对比分析。结果:与健康对照组比较,CHD组血TC[(4.03±0.97)mmol/L比(4.62±1.06)mmol/L]、LDL-C[(2.51±0.86)mmol/L比(3.76±1.07)mmol/L]水平明显升高(P均﹤0.01)。多因素Logistic回归分析显示,LDL-C水平升高是冠心病发生的独立危险因素(OR=2.608,95%CI=1.268-5.366;P=0.009)。结论:本研究人群冠心病患者TC、LDL-C水平显著高于健康对照组,LDL-C水平升高可能是发生冠心病的一个独立危险因素。     

高脂血症人群血清胆固醇酯转运蛋白的水平

目的分析不同高脂血症人群血清胆固醇酯转运蛋白水平及其对血浆各脂蛋白间脂质转运的调节作用。方法脂蛋白电泳结合酶显色法分别检测血清各脂蛋白中的甘油三酯含量;酶联免疫吸附试验测定血清胆固醇酯转运蛋白和氧化型低密度脂蛋白水平;分析胆固醇酯转运蛋白与脂质水平间的相关性。结果高甘油三酯组、高胆固醇组、混合组和对照组中胆固醇酯转运蛋白水平分别为1.89±1.32、2.37±1.30、2.33±1.73和1.58±1.00 mg/L,与对照组比较,高甘油三酯组变化无显著性(P>0.05),高胆固醇组(P<0.01)和混合组均升高(P<0.05)。高脂血症人群高密度脂蛋白中胆固醇/甘油三酯比值降低;高甘油三酯组和混合组低密度脂蛋白中甘油三酯/胆固醇比值升高,高胆固醇组无差别,其中高甘油三酯组变化程度最大,混合组次之,高胆固醇组最小;且胆固醇酯转运蛋白水平与上述比值相关。高脂血症人群血清氧化型低密度脂蛋白水平升高,与低密度脂蛋白中甘油三酯/胆固醇比值高度呈正相关。结论高脂血症人群胆固醇酯转运蛋白水平升高,促进了脂蛋白间脂质转运,使高密度脂蛋白和低密度脂蛋白脂质组成发生变化,促进了动脉粥样硬化的发生和发展。     

河北省饮水型地方性氟中毒重病区病情现状调查

目的掌握河北省饮水型地氟病重病区氟中毒流行状况.方法随机选取3个重病区县,采用分层整群抽样方法在每个县的非、轻、中、重病区分别抽取调查点,调查点的数量按被调查病区人口数应占该层病区人口总数10%的比例随机抽取.结果 3县总政水率为57.4%,轻、中、重病区改水率分别为42.9%、68.2%、70.2%.共采集居民饮用水水样165份,水氟均值士标准差为(1.00±1.14)mg/L.轻病区和非病区的水氟均值在正常标准内,中病区和重病区的水氟均值超过正常标准,水氟均值有随病区的严重程度的增加而增高的趋势.隆尧、博野两县的总水氟均值和各病区的水氟均值都在正常范围内,而阳原县的水氟均值超过正常标准,为(1.83±1.59)mg/L,其轻病区和非病区的水氟均值正常,中、重病区的水氟均值超标.共采集并测定8～12岁儿童尿样1 229份,总几何均值为1.57 mg/L,各层儿童尿氟的几何均值相差不大.阳原县8～1 2岁儿童的尿氟均值高于其它2县,其中、重病区的尿氟均值较高.共检查8～12岁儿童4 016名,发现各型氟斑牙患者1 060例,总检出率为19.95%,氟斑牙指数为0.35.非、轻、中、重病区的检出率分别为10.53%、1.613%、22.97%、32.54%,有逐渐升高的趋势.阳原县中、重病区的氟斑牙检出率和氟斑牙指数均较高,分别为53 7%、0.98和63 0%、1.38,为轻微和中等流行.结论我省地氟病重病区县的病情已基本得到控制,总体上已降至非病区的水平,但个别地区地氟病仍在流行,甚至达到中等程度.     

糖尿病人群空腹血糖水平与新发脑梗死事件的相关性研究

目的 探讨糖尿病人群空腹血糖水平与新发脑梗死事件的相关性.方法 采用前瞻性队列研究方法,以空腹血糖≥7.0 mmol/L或＜7.0 mmol/L但已确诊为糖尿病、正在使用降糖药物的8 306例糖尿人群作为观察队列,随访(48.01 ±3.14)个月,随访期间每半年收集一次新发脑梗死事件情况.分析糖尿病人群空腹血糖水平与新发脑梗死事件的相关性.结果 (1)随访结束时,随着基线空腹血糖水平的增高,研究对象的总胆固醇、甘油三酯的水平逐渐增高[总胆固醇:(4.93±1.15,510±1.20,5.15± 1.28,5.33±1.35) mmol/L,甘油三酯:(1.70±1.26,1.83± 1.29,2.18±1.76,2.41±2.08) mmol/L,P＜0.05];低密度脂蛋白胆固醇、收缩压、舒张压、体重指数的水平也增高(P＜0.05).(2) 7.0 mmol/L≤空腹血糖＜9.0mmol/L组累积发生脑梗死事件率最低(2.1％,P＜0.01).校正年龄、性别、收缩压、舒张压、总胆固醇、甘油三酯、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、体重指数、吸烟、糖尿病病程及降糖治疗因素,Cox比例风险回归分析表明,相对于7.0 mmol/L≤空腹血糖＜9.0 mmoL/L组,6.1 mmol/L≤空腹血糖＜7.0mmol/L组和空腹血糖≥9 mmol/L两组发生脑梗死事件的相对危险(RR)各分别增加1.85倍(95％CI 1.09～3.15,P＜0.05)、1.54倍(95％CI 1.16～2.05,P＜0.01).结论 糖尿病人群空腹血糖控制在7.0 ～9.0 mmol/L水平者似新发生脑梗死事件率最低.     

血脂生化检测在糖尿病诊治中的临床价值

目的探讨血脂生化检测在糖尿病诊治中的临床价值。方法随机选取具有可比性的同期到该院就诊的50例糖尿病患者(观察组)和50名健康体检者(对照组)为研究对象,应用同一台全自动生化分析仪,采用COD-PAP法测定血清总胆固醇,采用GPO-PAP法测定甘油三酯,采用表面活性剂清除法测定低密度脂蛋白,采用选择性抑制法测定高密度脂蛋白,具体检验操作步骤严格按照说明书执行,对两组研究对象的检测结果进行比较分析。结果对照组50名健康体检者的血清甘油三酯为(1.42±0.39)mmol/L,血清总胆固醇为(4.20±0.86)mmol/L,低密度脂蛋白为(2.35±0.78)mmol/L,高密度脂蛋白为(1.85±0.71)mmol/L;研究组50例糖尿病患者的血清甘油三酯为(2.44±0.32)mmol/L,血清总胆固醇为(5.81±0.91)mmol/L,低密度脂蛋白为(3.49±0.81)mmol/L,高密度脂蛋白为(0.76±0.64)mmol/L,两组研究对象TG、TC、LDL-C和HDL-C之间的差异均具有统计学意义(P0.05),对照组TG、TC、LDL-C低于观察组,对照组HDL-C高于观察组。结论糖尿病患者的血脂水平会出现明显异常,可作为糖尿病诊断和评价治疗效果的重要参考指标。在有效控制血糖的过程中,还应注意及时纠正血脂异常,使两者均尽快降至正常范围,对糖尿病患者转归和减少并发症产生明显促进作用。     

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.