早期生长反应因子1特异脱氧核酶对大鼠颈动脉损伤后纤溶酶原激活物抑制剂1表达的影响

目的观察早期生长反应因子1(Egr-1)的脱氧核酶(ED5)对大鼠颈动脉损伤后纤溶酶原激活物抑制剂1(PAI-1)水平的影响,初步探讨ED5防治血管内膜增生的机制。方法制备大鼠颈动脉球囊损伤模型,96只大鼠随机分为4组:假手术组、MgCl2组、FuGENE6组和ED5组,每组24只。用微量注射器将各种转染液注入损伤的血管壁,每组按实验终点(术后3、7、14和21天)再分4个亚组,每组6只大鼠。于术后各实验终点,取损伤段血管及血浆样本用于病理学检查、免疫荧光观察、免疫组织化学染色检查、ELISA检测。结果正常动脉早期生长反应因子1表达微弱,动脉损伤后3、7、14至21天,呈持续高表达,经ED5作用后,早期生长反应因子1的表达下降,与同一时间点的MgCl2组和FuGENE6组比较差异有显著性(P<0.01)。与MgCl2组和FuGENE6组比较,术后各时间点ED5组血管管腔狭窄率显著减小(P<0.01)。术后21天时,ED5组血管管腔的狭窄率比MgCl2组和Fu-GENE6组分别降低了58.90%和60.37%。术后各时间点,ED5组PAI-1表达量明显低于MgCl2组和FuGENE6组(P<0.01)。两对照组之间相比较,以上数据差异无显著性(P>0.05)。结论血管内膜损伤后PAI-1表达增加,ED5通过抑制早期生长反应因子1,下调PAI-1的表达,从而减轻血管损伤后早期血栓形成及内膜的增生。     

L-精氨酸对低氧性肺动脉高压大鼠肺动脉平滑肌细胞凋亡的影响

目的 探讨L-精氨酸(L-Arg)对低氧性肺动脉高压大鼠不同节段肺动脉平滑肌细胞凋亡的影响。方法 将Wistar大鼠(n=19)随机分为对照组(n=7)、低氧组(n=6)及低氧 L-Arg组(n=6)。经右心导管法测定各组大鼠肺动脉压力和右室(RV)/左室 室间隔(LV S)比值,以分光光度法间接测定血浆一氧化氮(NO)含量,通过TUNEL法检测各组大鼠不同节段的肺动脉平滑肌细胞凋亡数目,并计算肺动脉平滑肌细胞凋亡数目与肺动脉平滑肌细胞数目比值。结果 低氧组大鼠肺动脉平均压(PAMP)显著高于对照组[(2.71±0.29)kPa vs(2.05±0.14)kPa,P<0.01],低氧 L-Arg组大鼠的PAMP显著低于低氧组[(2.23±0.18)kPa vs(2.71±0.29)kPa,P<0.05];低氧组大鼠RV/(LV S)比值显著高于对照组[(0.42±0.03)kPa vs(0.30±0.05)kPa,P<0.01],低氧 L-Arg组大鼠RV/(LV S)比值显著低于低氧组[(0.36±0.02)kPa vs(0.42±0.03)kPa,P<0.01];低氧组大鼠血浆NO含量明显低于对照组[(3.54±0.47)μmol/L vs(4.79±0.17)μmol/L,P<0.05],低氧 L-Arg组大鼠血浆NO含量显著高于低氧组[(5.21±0.26)μmol/L vs(3.54±0.47)μmol/L,P<0.01];低氧组大鼠与终末细支气管伴行的肺动脉和与呼吸细支气管伴行的肺动脉平滑肌细胞凋亡数目与平滑肌细胞数目比值明显低于对照组[(0.051±0.016     

心绞痛患者血管内皮功能与冠状动脉病变的关系及临床意义

目的探讨血管内皮功能损伤在冠状动脉(冠脉)粥样硬化发生发展中的作用及相关的临床意义.方法不稳定型心绞痛组患者68例,稳定型心绞痛组58例.冠状动脉造影前检测一氧化氮、内皮素含量和高敏C反应蛋白,并检测肱动脉内皮舒张功能.根据造影结果将冠状动脉病变分为复杂狭窄和光滑狭窄.结果不稳定型心绞痛患者一氧化氮浓度低于稳定型心绞痛组(49.92μmol/L±10.46μmol/L比75.19μmol/L±5.21μmol/L,P=0.036),高敏C反应蛋白则高于稳定型心绞痛患者(4.21 mg/L±0.003 mg/L比0.50 mg/L±0.015 mg/L,P=0.004),两组内皮素浓度无明显差别;两组中有复杂狭窄者同无复杂狭窄者相比内皮素、一氧化氮浓度有明显差异,不稳定心绞痛组中有复杂狭窄者的内皮素明显高于稳定型心绞痛组中无复杂狭窄者(216.52pg/ml±33.63pg/ml比173.35 pg/ml±36.12 pg/ml,P＜0.001);两组肱动脉内皮功能检测无明显差异,但不稳定心绞痛组中有复杂病变者的肱动脉血流介导的血管扩张反应显著降低.结论不稳定心绞痛患者血管内皮功能损伤较稳定型心绞痛患者为重.冠脉造影所见的冠脉病变结合相关血管内皮功能检测,有助于更确切地评估冠脉病变进而评估斑块的稳定性.     

自发性高血压大鼠恐惧情绪与内皮舒张功能障碍的相关性

目的探讨恐志因素与自发性高血压大鼠(SHR)血管内皮舒张功能之间的关系。方法选取20只SHR按简单随机抽样方法分为SHR对照组和SHR恐志组,每组各10只;另设WKY大鼠10只为正常对照组。参照Takashi方法,通过测定3组大鼠血浆一氧化氮(NO)、内皮素(ET)、血清可溶性细胞间黏附分子1(sICAM-1)、血管内皮细胞黏附分子1(VCAM-1)水平及观察胸主动脉壁内皮细胞的形态学变化,探讨恐志对SHR血管内皮舒张功能的影响。结果 SHR恐志组大鼠的冻结时间较SHR对照组明显延长[(10.93±1.38)s比(3.95±0.58)s,P<0.01];与SHR对照组比较,WKY组大鼠的ET、VCAM-1和sICAM-1水平较低[(54.700±4.607)ng/L比(66.213±5.420)ng/L;(780.190±96.015)ng/L比(942.742±123.127)ng/L;(0.340±0.138)μg/L比(0.794±0.243)μg/L],NO水平较高[(44.200±1.733)μmol/L比(35.450±1.435)μmol/L],均为P<0.01;与SHR对照组比较,SHR恐志组ET[(71.348±4.764)ng/L]和NO[(37.020±1.280)μmol/L]水平升高(均为P<0.05),VCAM-1[(1040.746±140.803)ng/L]和sICAM-1[(0.847±0.192)μg/L]水平略高(均为P>0.05);与WKY组比较,SHR恐志组ET、VCAM-1和sICAM-1水平升高,NO水平降低(均为P<0.01)。扫描电镜显示,3组大鼠胸主动脉内皮细胞的形态均不相同:WKY组为正常大鼠胸主动脉壁内皮细胞形态;SHR对照组轻者内皮细胞基本上仍呈梭形,细胞膜呈条状撕脱,重者细胞皱缩变小,细胞膜损伤明显,并可见内皮下层的裸露区,无沉积物;SHR恐志组大鼠内皮细胞排列极度紊乱,细胞损伤严重,脱落较彻底,内皮层表面沉积物较多,被粗细不等、交错成网的纤维状物质包裹。结论恐志可以影响SHR的血管内皮舒张功能。     

局部应用没食子儿茶素-3-没食子酸抑制移植静脉内膜增生

目的探讨局部应用没食子儿茶素-3-没食子酸对移植静脉内膜增生的抑制作用及其发生机制。方法应用异硫氰酸荧光素荧光标记技术和高效液相色谱法体外定性和定量测定血管对没食子儿茶素-3-没食子酸的吸收情况。日本大耳白兔20只,随机分为没食子儿茶素-3-没食子酸处理组和对照组(n=10)。建立兔颈外静脉与颈内动脉间置移植模型,移植前没食子儿茶素-3-没食子酸处理组血管在0.1 g/L没食子儿茶素-3-没食子酸中常温保存1 h,而对照组血管保存在生理盐水中。组织学方法测定移植三周后移植静脉血管新生内膜厚度、内膜中膜厚度比,原位DNA断裂位点的3′-羟基末端标记、Ki67免疫组织化学染色测定新生内膜阳性细胞百分比。结果0.1g/L没食子儿茶素-3-没食子酸中保存1 h2、h4、h,静脉血管的吸收量分别为2.9±0.9 mg/g、5.8±2.1 mg/g和8.0±2.3 mg/g,分布在血管壁全层。两组移植血管术后3周的通畅率均为90%(9/10)。移植术后3周没食子儿茶素-3-没食子酸处理组较对照组内膜厚度(41.1±13.6μm比89.9±48.3μm,P<0.01)及内膜/中膜厚度比(0.40±0.18比0.77±0.31,P<0.05)均显著降低,新生内膜Ki67阳性染色平滑肌细胞百分比也显著下降(22.4%±8.6%比8.8%±2.4%,P<0.05),而凋亡细胞百分比(0.40%±0.55%比0.60%±0.89%,P>0.05)无明显变化。结论局部应用没食子儿茶素-3-没食子酸能够抑制移植静脉内膜增生,可能与其抑制内膜平滑肌细胞增殖有关。     

粒细胞-巨噬细胞集落刺激因子对损伤血管内膜增生及凝血纤溶功能的影响

目的:建立兔髂动脉球囊损伤模型,观察粒细胞-巨噬细胞集落刺激因子(granulocyte-macrophagecolony-stimulatingfactor,GM-CSF)对血管损伤后内膜增生及机体凝血纤溶功能的影响。方法:健康新西兰雄性大白兔24只,随机分为GM-CSF组和对照组。GM-CSF组皮下注射GM-CSF10μg·kg-1·d-1,对照组皮下注射同等量生理盐水。7d后球囊扩张损伤一侧髂动脉。术后4周处死动物,采集标本,观察内膜增生情况;分别于术前、术后1周,2周,4周耳缘静脉采血检测一氧化氮(NO)浓度、组织型纤溶酶原激活剂(tissue-typeplasminogenactivator,t-PA)活性和纤溶酶原激活物抑制剂-1(plasminogenactivatorinhibitor-1,PAI-1)活性。结果:术后4周病理组织学见GM-CSF组内膜增生程度较对照组明显减轻,新生内膜中血管平滑肌细胞和纤维组织较对照组明显减少,内皮较完整、光滑,管腔狭窄程度较轻。GM-CSF组术后2周,4周NO浓度明显高于对照组[(91·9±11·6)μmol/Lvs(81·7±12·2)μmol/L];[(97·7±10·1)μmol/Lvs(83·2±12·6)μmol/L];术后1周,2周,4周t-PA活性2组均高于术前,但2组间差异无统计学意义;2组术前、术后PAI-1活性差异无显著性,2组间亦差异无显著性。结论:GM-CSF能促进损伤内膜修复,恢复正常内皮功能,且并未诱导球囊损伤动物机体的高凝状态。     

普伐他汀早期应用对急性冠状动脉综合征血管炎症反应及内皮功能的影响

目的观察普伐他汀在急性冠状动脉综合征患者早期(发病48h以内)应用对患者血浆一氧化氮、内皮素及C反应蛋白的影响。方法60例急性冠状动脉综合征患者随机分为两组。普伐他汀组30例,常规治疗组(未服用他汀类调脂药物)30例,疗程2周,分别于治疗前后测定血浆一氧化氮、内皮素及C反应蛋白水平。结果普伐他汀组血浆C反应蛋白(32.7±10.8μg/L)及内皮素(50.3±17.2μg/L)水平明显下降、血浆一氧化氮(50.3±10.2μmol/L)水平明显上升,与常规治疗组血浆C反应蛋白(44.3±9.7μg/L)、内皮素(72.4±16.4μg/L)及血浆一氧化氮(42.8±8.7μmol/L)水平比较有显著性差异(P<0.01)。结论普伐他汀在急性冠状动脉综合征患者中早期应用能够抑制血管内皮的炎症反应,稳定粥样斑块,改善血管内皮功能,解除冠状动脉痉挛。     

多沙唑嗪对高血压患者动态血管平滑肌细胞NO产生的影响

采用高血压患者的肠系膜动脉进行分离培养,检测细胞培养液中的NO含量.结果多沙唑嗪治疗组的NO含量高于对照组(74.56±4.56μmol/L,42.77±6.76μmol/L,P<0.05).认为多沙唑嗪增加了高血压患者动脉血管平滑肌细胞NO的产生.     

缺氧性肺动脉高压大鼠尾加压素Ⅱ、一氧化氮和C型利钠肽的表达及意义

目的检测缺氧性肺动脉高压(HPH)大鼠血浆和肺匀浆中尾加压素(U-Ⅱ)、一氧化氮(NO)和C型利钠肽(CNP)的变化,探讨氧疗及这些因子在HPH中的作用。方法雄性W istar大鼠30只均分为对照组、缺氧组、氧疗组。测定各组平均体动脉压(mSAP)、肺动脉平均压(mPAP)、右室肥厚指数(RVH I),血浆U-Ⅱ、NO、CNP水平,肺匀浆U-Ⅱ、CNP水平,光镜观察肺动脉结构改变,扫描电镜观察肺小动脉超微结构。结果缺氧组大鼠mPAP、RVH I[(34.1±2.8)mm Hg、0.43±0.11]显著高于对照组[(18.9±2.0)mm Hg、0.28±0.04,P均<0.01],血浆U-Ⅱ、NO、CNP[(4.4±0.9)pg/m l、(20.8±7.0)μmol/L、(6.6±1.2)pg/m l]均显著高于对照组[(0.9±0.4)pg/m l、(13.2±2.0)μmol/L、(4.0±0.6)pg/m l,P均<0.01],肺匀浆U-Ⅱ、CNP[(6.3±0.5)、(1.89±0.43)pg/m l]亦显著高于对照组[(2.6±0.5)、(0.69±0.21)pg/m l,P均<0.01]。氧疗组大鼠mPAP,血浆U-Ⅱ、NO、CNP,肺匀浆U-Ⅱ、CNP分别为(31.4±2.0)mm Hg,(2.1±0.7)pg/m l、(14.8±1.7)μmol/L、(4.4±0.7)pg/m l,(3.5±0.8)pg/m l、(0.74±0.17)pg/m l;与缺氧组比较差异均有统计学意义(P均<0.01),而RVH I差异无统计学意义(P>0.05)。光镜和电镜下,氧疗组肺血管形态学改变较缺氧组轻。结论缺氧导致HPH形成,U-Ⅱ、NO和CNP参与HPH的病理生理过程,这些因子之间比值失衡可能是导致HPH发生发展的因素之一。     

卡维地洛对冠状动脉成形术后患者外周血内皮素及一氧化氮的影响

为探讨卡维地洛对冠心病患者经皮腔内冠状动脉成形术后血中内皮素及一氧化氮的影响 ,本文选择经冠状动脉造影证实有一支或二支以上≥ 70 %狭窄需行经皮腔内冠状动脉成形术的患者 5 1例 ,随机分成卡维地洛组2 8例和常规治疗组 2 3例 ,测定经皮腔内冠状动脉成形术前后及用药前后外周血内皮素及一氧化氮含量。结果发现 ,经皮腔内冠状动脉成形术后血中内皮素 (卡维地洛组为 84 .9± 14 .7μg/L、常规治疗组为 85 .6± 15 .4 μg/L)较术前 (卡维地洛组为 70 .6± 12 .8μg/L、常规治疗组为 71.5± 13.3μg/L)增高 ;一氧化氮 (卡维地洛组为 5 0 .3± 13.4μmol/L、常规治疗组为 5 0 .9± 12 .6 μmol/L)较术前 (卡维地洛组为 6 2 .9± 14 .2 μmol/L、常规治疗组为 6 3.5± 13.1μmol/L)降低 (P <0 .0 5 ) ;卡维地洛组内皮素为 74 .6± 15 .6 μg/L ,较用药前 (84 .4± 14 .9μg/L)降低 ;一氧化氮为 6 2 .7± 12 .8μmol/L ,较用药前 (5 1.6± 12 .5 μmol/L)增高 (P <0 .0 5 ) ,常规治疗组内皮素和一氧化氮观察两周均无显著变化 (P >0 .0 5 )。提示卡维地洛具有改善冠状动脉成形术后血管内皮功能的作用     

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.     

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.