高脂血症患者LDL氧化易感性及调脂药物干预的影响

目的观察高脂血症对LDL氧化易感性的影响以及调脂药物干预后的改变.方法应用短程密度梯度超速离心分离血浆LDL,对11例高甘油三酯血症患者口服微粒化非诺贝特200 mg/d、10例高胆固醇血症患者口服普伐他汀10 mg/d治疗4周前后和6例正常人的LDL在体外以CuCl2诱导氧化,测定LDL开始氧化的迟滞期和氧化速率.结果 (1)LDL氧化的迟滞期,在高甘油三酯血症患者和高胆固醇血症患者均较正常组明显缩短(43.8±11.6,40.8±10.7 vs 70.5±14.6 min, P均<0.01).(2)LDL的氧化速率,在高甘油三酯血症患者和高胆固醇血症患者均较正常组明显增快(0.036±0.004,0.031±0.011 vs 0.020±0.011 O.D./min,P均<0.05).(3)高甘油三酯血症患者给微粒化非诺贝特治疗后LDL氧化的迟滞期显著延长(62.4±5.0 min,P<0.01),氧化速率明显减慢(0.031±0.003 O.D./min,P<0.05).(4)高胆固醇血症患者于普伐他汀治疗后LDL氧化的迟滞期明显延长(58.8±6.1 min,P<0.05),氧化速率无显著性变化(0.025±0.009 O.D./min,P>0.05).结论高甘油三酯血症患者和高胆固醇血症患者LDL氧化易感性增高,微粒化非诺贝特和普伐他汀能够降低高甘油三酯血症患者及高胆固醇血症患者LDL的氧化易感性.     

高脂血症患者低密度脂蛋白氧化易感性及调脂药物干预的影响

目的　观察高脂血症对低密度脂蛋白 (LDL)氧化易感性的影响以及调脂药物干预后的改变。方法　应用短程密度梯度超速离心分离血浆LDL ,对 11例高甘油三酯血症患者口服微粒化非诺贝特 2 0 0mg d、10例高胆固醇血症患者口服普伐他汀 10mg d治疗 4周前、后和 6例正常人的LDL在体外以CuCl2 诱导氧化 ,测定LDL开始氧化的迟滞期和氧化速率。结果　 (1)LDL氧化的迟滞期 :在高甘油三酯血症患者 [(43 8± 11 6 )min]和高胆固醇血症患者 [(40 8± 10 7)min]均较正常组 [(70 5±14 6 )min]明显缩短 (P均 <0 0 1)。 (2 )LDL的氧化速率 :在高甘油三酯血症患者 [(0 0 36± 0 0 0 4 )A min]和高胆固醇血症患者 [(0 0 31± 0 0 11)A min]均较正常组 [(0 0 2 0± 0 0 11)A min]明显增快 (P均 <0 0 5 )。 (3)高甘油三酯血症患者于微粒化非诺贝特治疗后LDL氧化的迟滞期 [(6 2 4± 5 0 )min]显著延长 (P <0 0 1) ,氧化速率 [(0 0 31± 0 0 0 3)A min]明显减慢 (P <0 0 5 )。 (4)高胆固醇血症患者于普伐他汀治疗后LDL氧化的迟滞期 [(5 8 8± 6 1)min]明显延长 (P <0 0 5 ) ,氧化速率 [(0 0 2 5± 0 0 0 9)A min]无显著性变化 (P >0 0 5 )。结论　高甘油三酯血症患者和高胆固醇血症患者LDL氧化易感性增     

微粒化非诺贝特对高三酰甘油血症患者血管内皮功能的作用

目的 :探讨微粒化非诺贝特对高三酰甘油血症患者血管内皮功能的作用。方法 :对 30例高三酰甘油血症患者 (口服微粒化非诺贝特 2 0 0mg/d治疗 4周前后 )和 30例正常人采用高分辨超声技术检测血流介导的和硝酸甘油介导的肱动脉舒张功能 ,并测定血浆内皮素 (ET)和血脂。结果 :①高三酰甘油血症组血流介导的肱动脉舒张反应较正常组明显减弱 [(2 .7± 2 .0 ) %∶(15 .0± 8.0 ) % ,P <0 .0 1],而两组对硝酸甘油的血管舒张反应差异无显著性意义 [(15 .0± 5 .0 ) %∶(16 .8± 9.0 ) % ,P >0 .0 5 ]。②高三酰甘油血症患者微粒化非诺贝特治疗后血流介导的肱动脉舒张显著改善 [(11.0± 9.0 ) % ,P <0 .0 1],而硝酸甘油介导的血管舒张较治疗前无明显改变[(16 .2± 6 .0 ) % ,P >0 .0 5 ]。③高三酰甘油血症患者血浆ET水平显著高于正常人 [(10 6 .2± 19.2 ) μg/L∶(72 .4± 14 .1) μg/L ,P <0 .0 1],微粒化非诺贝特治疗后血浆ET水平显著降低 [(82 .7± 15 .5 ) μg/L ,P <0 .0 1],血清三酰甘油明显降低 (P <0 .0 5 )。结论 :微粒化非诺贝特对高三酰甘油血症患者受损的血管内皮依赖性舒张功能有改善作用。改善血管内皮功能亦是微粒化非诺贝特防治冠心病的作用机制之一     

非诺贝特对高胆固醇血症兔体重及脂肪组织过氧化体增殖物激活受体表达的影响

目的 :观察非诺贝特短期干预对高胆固醇血症兔体重和皮下脂肪量的影响 ,并阐明其可能机制。方法 :10只新西兰大白兔给予高胆固醇饲料饲养 8周后 ,随机分为两组 :①高胆固醇组 :继续饲以高胆固醇饲料 4周 ;②治疗组 :在饲以高胆固醇饲料的基础上给予非诺贝特 (30mg·kg-1·d-1) ,共 4周。另选普通饮食 12周兔 (5只 )作为对照组。实验结束后 ,取皮下脂肪组织称量 ,并行前脂肪细胞培养 ,应用半定量逆转录多聚酶链式反应(RT PCR)测定脂肪组织和细胞PPARγ和PPARαmRNA的表达。结果 :高胆固醇组血清总胆固醇、低密度脂蛋白胆固醇水平明显高于对照组 (P <0 .0 1) ,非诺贝特干预 4周未对血脂产生影响 ,但能降低体重及皮下脂肪量(均P <0 .0 5 ) ,RT PCR结果显示高胆固醇组脂肪组织PPARγmRNA表达高于对照组 [(0 .5 75± 0 .14 )∶(0 .4 2 5± 0 .0 8) ,P <0 .0 5 ],非诺贝特能降低高胆固醇饲养兔脂肪组织PPARγmRNA表达 [(0 .4 78± 0 .11)∶(0 .5 75±0 .14 ) ,P >0 .0 5 ],并呈剂量依赖性的降低前脂肪细胞PPARγmRNA表达。 3组兔脂肪组织PPARαmRNA表达差异无统计学意义。结论 :非诺贝特独立于降脂作用外 ,能降低高胆固醇血症兔体重和皮下脂肪量 ,其机制之一可能与下调脂肪细胞PPARγmRNA表达有关。这一作用可     

非诺贝特与普伐他汀联合治疗混合性高脂血症的远期疗效及安全性

目的　探讨非诺贝特和普伐他汀联合治疗混合性高脂血症的远期疗效及安全性。方法　 38例确诊混合性高脂血症患者 ,联合应用非诺贝特和普伐他汀 (微粒化力平脂 2 0 0mg/d ,普拉固 10mg/d) ,进行为期 2年的治疗 ,治疗前后均测定空腹血脂、肌酸磷酸激酶 (CPK)、肝肾功能以及尿酸等指标 ,观察对患者的远期疗效和安全性。结果　联合治疗患者总胆固醇 (TC)显著下降 2 5 %± 6 % ,甘油三酯 (TG)下降 40 %± 5 % ,低密度脂蛋白 (LDL C)下降 2 7%± 3% ,高密度脂蛋白 (HDL C)上升 2 1%± 6 % ;谷丙转氨酶 (ALT)活性上升(3± 2 )U·L-1(无显著意义 ) ,CPK活性下降 (4± 8)U·L-1(无显著意义 ) ,无一例出现严重并发症。结论　非诺贝特联合普伐他汀治疗肝肾功能正常的混合性高脂血症患者是有效而且安全的。     

高甘油三酯血症对血管内皮功能的影响

目的　观察高甘油三酯血症对血管内皮功能的影响。方法　对 30名高甘油三酯血症患者和 30名正常人采用高分辨超声技术检测血流介导和硝酸甘油介导的肱动脉舒张功能 ,并测定血浆内皮素和血脂。结果　 (1)高甘油三酯血症患者血流介导的肱动脉舒张较正常组明显减弱 [分别为(2 7± 2 0 ) %和 (15 0± 8 0 ) % ,P <0 0 0 1],而两组对硝酸甘油的血管舒张反应无显著性差异 [分别为 (15 0± 5 0 ) %和 (16 8± 9 0 ) % ,P >0 0 5 ]。 (2 )高甘油三酯血症患者血浆内皮素水平 [(10 6 2 2± 19 16 ) μg/L]显著高于正常组 [(72 37± 14 0 6 ) μg/L](P <0 0 0 1)。 结论　高甘油三酯血症患者内皮依赖性血管舒张功能明显受损。血管内皮功能失调可能是高甘油三酯血症致动脉粥样硬化的一个重要机制。     

非诺贝特抑制脂肪细胞组织因子表达

为探讨动脉粥样硬化兔脂肪细胞组织因子表达及非诺贝特对其的影响 ,将 15只兔随机分为正常组、动脉粥样硬化组和非诺贝特组 ,非诺贝特组在高胆固醇饮食第 9周起加用非诺贝特 (每天 30mg/kg)干预 4周 ,采用逆转录聚合酶链反应测定脂肪细胞组织因子的表达。结果发现 ,高胆固醇饮食可显著升高血清总胆固醇 (P <0 .0 5 ) ,甘油三酯无明显升高 ;加用非诺贝特治疗 4周 ,总胆固醇和甘油三酯均无明显改变。动脉粥样硬化组脂肪细胞组织因子表达明显高于正常组 (1.0 81± 0 .0 11比 0 .939± 0 .0 18,P <0 .0 1) ,非诺贝特治疗 4周后组织因子表达较动脉粥样硬化组显著降低 (0 .893± 0 .0 2 2比 1.0 81± 0 .0 11,P <0 .0 1)。结果提示 ,动脉粥样硬化组兔脂肪细胞表达组织因子明显增加 ,非诺贝特能抑制其表达 ,提示非诺贝特可能具有抗血栓作用     

微粒化非诺贝特对Ⅳ型高脂血症患者血清低密度脂蛋白亚组份再分布的作用

目的　观察微粒化非诺贝特对Ⅳ型高脂血症患者血清低密度脂蛋白亚组份再分布的作用。方法　口服微粒化非诺贝特2个月( 2 0 0mg ,每晚1粒) ,共治疗患者2 6例,对治疗后出现血清低密度脂蛋白-胆固醇水平升高15 %以上的共12例患者,进一步用超速离心法观察药物对血清低密度脂蛋白亚组份(LDL1 :1.0 2 5kg L～1.0 34kg L ,LDL2 :1.0 34kg L～1.0 44kg L)再分布的作用。结果　微粒化非诺贝特治疗后,血清甘油三酯水平平均下降5 3.4%～6 4.4% (P<0 .0 0 1) ,低密度脂蛋白-胆固醇明显升高37.3%～79.4% (P<0 .0 0 1) ,总胆固醇、高密度脂蛋白-胆固醇水平无明显改变。治疗前患者的低密度脂蛋白亚组份分布以小而密低密度脂蛋白3为主,LDL3 占总低密度脂蛋白的34.7%±8.6 % ,分布曲线呈多峰、不均一态分布;治疗后低密度脂蛋白3比例显著降低35 .0 %±2 7.3 % (P<0 .0 0 1) ,低密度脂蛋白2显著升高46 .9%±2 9.0 % (P<0 .0 1) ,低密度脂蛋白亚组份分布曲线转向单峰、较均一态分布。治疗后低密度脂蛋白颗粒的化学组成构成比( % )发生较大变动,其中甘油三酯的构成比显著降低(P<0 .0 1) ,胆固醇酯的构成比和蛋白质的构成比不同程度增高,游离胆固醇的构成比无明显变化。结论　微粒化非诺贝特能明显的降低Ⅳ型高脂血症患者血浆甘油三酯水平和升高部分患者的低密度脂蛋白-胆固醇水平,有使不正常低密度脂蛋白亚组份分布及组成趋向正常化分布的作用     

他汀类药物对原发性高胆固醇血症患者血管内皮功能的影响

目的　观察辛伐他汀和氟伐他汀对原发性高胆固醇血症患者血管内皮功能的影响。方法　 6 0例原发性高胆固醇血症患者随机分为辛伐他汀组 (5mg/d)或氟伐他汀组 (2 0mg/d) ,每组 30例 ,均治疗 8周 ,2 0例正常对照。采用超声多普勒于治疗前后对其进行血管内皮功能的测定。结果　原发性高胆固醇血症患者肱动脉血流介导的舒张反应较对照组明显减弱 [辛伐他汀组 (3 38±5 48) % ,氟伐他汀组 (1 17± 5 15 ) % ,对照组 (17 5 8± 6 47) % ,P <0 0 0 1],而三组对硝酸甘油的反应差异无显著性 [分别为 (14 6 4± 6 6 8) % ,(14 46± 7 80 ) % ,(18 31± 6 84) % ,P >0 0 5 ]。辛伐他汀或氟伐他汀治疗 8周后均使血清总胆固醇和低密度脂蛋白胆固醇显著降低 ,同时肱动脉内皮依赖性舒张功能较治疗前亦有明显改善 [辛伐他汀组为 (14 6 8± 5 0 5 ) %比 (3 38± 5 48) % ,氟伐他汀组为(13 94± 6 6 8) %比 (1 17± 5 15 ) % ,P值均 <0 0 0 1],而治疗前后肱动脉对硝酸甘油的反应无显著性变化。结论　原发性高胆固醇血症患者血管内皮依赖性舒张功能受损 ,辛伐他汀或氟伐他汀治疗均可显著改善血管内皮依赖性舒张功能 ,二者之间差异无显著性。     

微粒化非诺贝特对Ⅳ型高脂血症患者血清低密度脂蛋白亚组份再分布的作用

目的　观察微粒化非诺贝特对IV型高脂血症患者血清低密度脂蛋白 (LDL)亚组份再分布的作用。方法　口服微粒化非诺贝特 2个月 ( 2 0 0mg ,每晚 1粒 ) ,共治疗患者 2 6例 ,对治疗后出现血清LDL 胆固醇水平升高 15 %以上的共 12例患者 ,进一步用超速离心法观察药物对血清LDL亚组份 (LDL1∶1 0 2 5g/ml～ 1 0 3 4g/ml,LDL2 ∶1 0 3 4g/ml～ 1 0 4 4g/ml和LDL3∶1 0 4 4g/ml～ 1 0 63g/ml)再分布的作用。结果　微粒化非诺贝特治疗后 ,血清甘油三酯 (TG)水平平均下降 5 3 4 %～ 64 4 % (P <0 0 0 1) ,LDL 胆固醇明显升高 3 7 3 %～ 79 4 % (P <0 0 0 1) ,总胆固醇、高密度脂蛋白 胆固醇水平无明显改变。治疗前患者的LDL亚组份分布以小而密LDL3为主 [LDL3占总LDL的 ( 3 4 7± 8 6) % ],分布曲线呈多峰、不均一态分布 ;治疗后LDL3比例显著降低 [降低 ( 3 5 0± 2 7 3 ) % ,P <0 0 0 1]、LDL2 显著升高 [升高 ( 4 6 9± 2 9 0 ) % ,P <0 0 0 1],LDL亚组份分布曲线转向单峰、较均一态分布。治疗后LDL颗粒的化学组成构成比 ( % )发生较大变动 ,其中TG %显著降低 (P <0 0 1) ,胆固醇酯 %和蛋白质 %不同程度增高 ,游离胆固醇 %和磷脂 %无明显变化。结论　微粒化非诺贝特能明显的降低IV型高脂血症患者血浆甘油     

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.