IL-22BP在活动期炎症性肠病患者肠黏膜中的表达及其意义

背景:白细胞介素-22结合蛋白(IL-22BP)是IL-22的内源性抑制剂,可抑制IL-22的肠道保护作用,在活动期炎症性肠病(IBD)患者肠黏膜中的表达及其意义尚未明确。目的:探讨IL-22BP在活动期IBD患者肠黏膜中的表达及其意义。方法:纳入2017年1月—2018年1月上海交通大学附属第一人民医院的25例活动期克罗恩病(CD)、36例溃疡性结肠炎(UC)患者,并以30例结肠息肉患者作为对照。评估CD、UC患者的疾病活动度,采用实时荧光定量PCR和免疫组化法分别检测黏膜中IL-22BP mRNA和蛋白表达,并分析IL-22BP蛋白表达与CD、UC疾病活动度的相关性。结果:与相应对照组相比,CD组、UC组肠黏膜中IL-22BP mRNA表达显著升高(CD:3.59±0.83对1.08±0.45,P0.001;UC:2.19±0.52对1.05±0.34,P0.001),IL-22BP蛋白表达亦显著升高(CD:6.12±2.30对1.83±1.86,P0.001;UC:5.58±2.27对2.23±1.77,P0.001)。CD、UC患者肠黏膜中IL-22BP蛋白表达与疾病活动度均呈显著正相关(r=0.649,P0.001;r=0.732,P0.001)。结论:IL-22BP mRNA和蛋白表达在活动期IBD患者肠黏膜中升高,且IL-22BP蛋白表达与IBD疾病活动度呈正相关。     

白细胞介素-25在炎症性肠病患者中的表达及临床意义

目的 通过检测白细胞介素(IL)-25在炎症性肠病(IBD)患者肠黏膜及血清中的表达水平,探讨其在IBD发病过程中的作用及意义.方法 收集12例溃疡性结肠炎(UC)患者、16例克罗恩病(CD)患者及13例对照者的内镜肠黏膜活检标本,采用荧光定量PCR技术检测肠黏膜内IL-25 mRNA的表达情况,免疫组化技术分析IL-25在肠黏膜中的原位表达;同期收集20例UC、24例CD患者及20名健康对照者血清标本,采用酶联免疫吸附测定(ELISA)检测血清中IL-25水平.结果 与健康对照组相比,UC及CD患者肠黏膜组织内IL-25 mRNA表达显著降低(P＜0.05),UC及CD组间的表达量差异无统计学意义(P＞0.05).免疫组化分析显示IL-25阳性细胞在正常肠黏膜固有层内有较多表达,同时黏膜内的肠上皮细胞也存在IL-25低表达,UC及CD患者肠黏膜IL-25蛋白表达量显著降低(P＜0.05),UC及CD组间的表达量差异无统计学意义(P＞0.05).ELISA显示UC及CD患者血清中IL-25表达量显著低于健康对照组(P＜0.05).结论 IL-25在IBD患者肠黏膜及血清中表达显著降低,提示IL-25表达缺陷与IBD的发生发展密切相关,IL-25有可能成为IBD治疗的新靶点.     

CXC趋化因子受体2和白细胞介素-8在炎症性肠病患者中的表达及其意义

背景:CXC趋化因子受体2(CXCR2)为G蛋白耦联受体超家族成员,主要参与肿瘤生长、血管形成以及炎症性疾病的发病,有研究显示其参与炎症性肠病(IBD)发病,但相关作用仍未明确。研究表明白细胞介素-8(IL-8)与CXCR1和CXCR2的相互作用在IBD发病中发挥重要作用。目的:探讨CXCR2和IL-8在IBD患者中的表达及其意义。方法:纳入武汉大学中南医院2013年10月—2014年12月收治的活动期IBD患者121例,分为克罗恩病(CD)组和溃疡性结肠炎(UC)组,选取70例同期健康体检者作为正常对照(HC)组。采用real-time PCR检测外周血和肠黏膜组织IL-8和CXCR2 mRNA表达;采用蛋白质印迹法检测肠黏膜组织CXCR2蛋白表达。结果:UC组外周血IL-8 mRNA表达水平显著高于HC组(P=0.017);CD组、UC组和HC组外周血CXCR2 mRNA表达水平无明显差异(P=0.285)。CD组、UC组和HC组肠黏膜组织IL-8 mRNA表达水平无明显差异(P=0.206);CD组和UC组肠黏膜组织CXCR2 mRNA表达水平显著高于HC组(P=0.002;P0.001),且UC组显著高于CD组(P=0.005)。UC组和CD组肠黏膜组织CXCR2蛋白表达水平高于HC组(P=0.049;P=0.080)。结论:IBD患者肠黏膜组织CXCR2 mRNA和蛋白表达均显著上调,且以UC患者为著,下调肠黏膜CXCR2表达可为治疗UC提供新靶点。IL-8主要在UC患者外周血中高表达,提示IL-8主要与UC发病相关。     

PGC-1α在炎症性肠病肠黏膜组织中的表达及临床意义

目的:检测过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)在炎症性肠病(inflammatory bowel disease,IBD)患者肠黏膜的表达水平,探讨其在IBD患者肠黏膜组织中的作用.方法:收集15例溃疡性结肠炎(Ulcerative colitis,UC)患者、17例克罗恩病(Crohn’s disease,CD)患者炎性肠黏膜活检标本及14例正常对照者内镜肠黏膜标本,采用免疫组织化学染色技术分析PGC-1α蛋白在肠黏膜中的原位表达,荧光定量PCR技术检测肠黏膜内PGC-1αmRNA的表达水平.结果:免疫组织化学分析显示:PGC-1α蛋白在正常肠黏膜上皮细胞内表达较多,黏膜固有层细胞内表达较少.与正常对照组相比,PGC-1α蛋白在UC患者肠黏膜上皮细胞内表达量明显减少,而肠黏膜固有层细胞内表达增加,PGC-1α蛋白在CD患者肠黏膜组织内表达量无明显差异.荧光定量PCR分析显示:UC患者炎症肠黏膜组织内PGC-1αmRNA表达水平显著低于正常对照组(0.48±0.15vs1.59±0.38,P<0.05),CD患者炎症肠黏膜组织内PGC-1αmRNA表达水平与正常对照组相比差异无统计学意义(1.55±0.47vs1.59±0.38,P>0.05).结论:与正常对照组相比,PGC-1α在UC炎症肠黏膜组织内表达水平降低,而在CD炎症肠黏膜中表达无明显差异,提示PGC-1α可能参与了UC发生发展过程.     

白细胞介素-23在炎症性肠病的表达升高并诱导促炎细胞因子分泌

目的 通过分析白细胞介素(IL)-23p19及其受体(IL-23R)在炎症性肠病(IBD)患者中的表达,研究IL-23对IBD患者外周血T细胞激活和效应应答的影响,探讨其在疾病发生过程中的免疫病理作用.方法 收集12例克罗恩病(CD)患者、25例溃疡性结肠炎(UC)患者和20名健康者外周血和肠黏膜组织活检标本,使用免疫组化染色和逆转录(RT)-PCR分析IL-23p19表达,分离外周血单个核细胞(PBMC)和肠黏膜固有层内单个核细胞(LPMC),利用流式细胞仪检测IL-23R在CD4+、CD8+T细胞和自然杀伤(NK)细胞表面表达.体外培养PBMC,使用IL-23和抗CD3单抗体外刺激,使用酶联免疫吸附试验检测肿瘤坏死因子(TNF)-α、干扰素(IFN)-γ和白细胞介素(IL)-2分泌.结果 IBD患者炎症肠黏膜组织内IL-23p19蛋白和mRNA表达水平比健康对照者显著升高(P<0.05).IL-23R在IBD患者外周血和肠黏膜固有层组织内CD4+、CD8+T细胞和NK细胞表达水平也比健康者显著升高(P<0.05).体外培养PBMC,使用IL-23刺激,发现IL-23可显著诱导IBD患者,尤其是CD患者PBMC激活,分泌高水平TNF-α、IFN-γ和IL-2(P<0.05).结论 IL-23及其受体在IBD患者炎症肠黏膜组织中表达升高,IL-23可诱导IBD患者淋巴细胞分泌高水平的炎性介质,提示IL-23参与了肠黏膜炎症损伤,阻断IL-23生物学效应可能治疗IBD.     

炎症性肠病患者肠黏膜炎症和非炎症组织CD27的激活表达

目的比较炎症性肠病患者肠黏膜炎症组织、非炎症组织及正常对照者肠黏膜CD27激活表达的差异,探讨CD27激活表达在炎症性肠病发病中的意义。方法共纳入32例克罗恩病患者、41例溃疡性结肠炎患者及40例正常对照者。分别应用West-ern blot试验和SYBR-green real time PCR方法分析炎症性肠病患者肠黏膜炎症组织、非炎症组织及正常对照者肠黏膜CD27蛋白及其mRNA的表达。数据处理使用GraphPad Prism 5软件。结果克罗恩病和溃疡性结肠炎患者肠黏膜炎症组织CD27蛋白及其mRNA表达均显著高于非炎症组织及正常对照组织(P均0.01);克罗恩病患者肠黏膜非炎症组织CD27蛋白及其mRNA表达显著高于正常对照组织(P=0.000);溃疡性结肠炎患者肠黏膜非炎症组织CD27蛋白表达显著高于正常对照组织(P=0.000)。结论炎症性肠病患者肠黏膜组织中存在CD27的激活表达,这种激活效应不仅出现在内镜表现为炎症性肠病的炎症组织中,甚至出现在炎症性肠病患者内镜表现为正常的肠黏膜中,CD27的激活表达是炎症性肠病发病的早期事件。     

感染后肠易激综合征与溃疡性结肠炎缓解期患者肠黏膜细胞因子表达的相关性

目的:探讨感染后肠易激综合征(PI-IBS)与溃疡性结肠炎(UC)缓解期患者结肠黏膜细胞因子表达的相关性.方法:PI-IBS组26例,UC组45例及对照组30例,结肠镜下活检降结肠和直肠黏膜标本,采用免疫组化SABC法检测其肠黏膜P物质(SP)与IL-2,IFN-γ的表达情况.结果:PI-IBS组降结肠和直肠黏膜IFN-γ和IL-2阳性率表达、SP强度均值和面积高于对照组(IFN-γ:χ2=13.781,14.012,P＜0.01;IL-2:χ2=13.890,13.931,P＜0.01;SP强度:t=3.623,3.722,P＜0.01;SP面积:t=3.454,3.561,P＜0.01),但与UC组患者无显著差异.降结肠、直肠黏膜IFN-γ,IL-2阳性表达的PI-IBS患者,SP强度均值(t=2.202,2.220,P＜0.05)、面积高于对照组(t=2.301,2.252,P＜0.05),与UC组患者也无显著差异.结论:PI-IBS和UC缓解期患者细胞因子表达无显著差异.从神经-免疫机制上分析认为IBS与炎症性肠病(IBD)之间存在某种相关性,IBS可能是轻微的IBD.     

炎症性肠病患者CD27-CD70共刺激途径的激活研究

目的 探讨CD27-CD70共刺激途径在炎症性肠病患者外周循环和肠黏膜中的表达,比较炎症性肠病患者CD27-CD70表达与正常对照者间的差异.方法 共纳入62例克罗恩病(CD)、64例溃疡性结肠炎(UC)患者和56名正常对照者.应用酶联免疫吸附试验分析炎症性肠病患者和正常对照者血浆中CD27-CD70蛋白的表达;SYBR-green实时PCR法分析炎症性肠病患者和正常对照者外周血单个核细胞中CD27-CD70 mRNA的表达;免疫组化法分析炎症性肠病患者和正常对照者肠黏膜组织CD27-CD70蛋白的表达.结果 CD和UC患者血浆中CD27-CD70的表达均显著高于正常对照者(P值均<0.05).ROC曲线的分析表明,CD27-CD70对区分CD患者和正常对照者以及区分UC患者和正常对照者具有显著的诊断价值(P值均<0.05).CD患者血浆中CD27和CD70水平与内镜下疾病活动性(EDAI)无关(r值分别=0.055和0.024,P值分别为0.673和0.852),且UC患者血浆中CD27和CD70水平与EDAI无关(r值分别=0.077和0.021,P值分别为0.547和0.869).CD患者和UC患者外周血单个核细胞CD27和CD70 mRNA表达均显著高于正常对照者外周血单个核细胞中mRNA的表达(P值均=0.000).免疫组化实验表明CD患者和UC患者肠黏膜组织CD27和CD70的表达均显著高于正常对照者(P值均=0.000).结论 炎症性肠病患者血浆、外周血单个核细胞和肠黏膜中均存在CD27-CD70途径的激活,但血浆中CD27-CD70的水平不能反映内镜下疾病活动程度.选择性干预CD27-CD70共刺激通路可能成为缓解或减轻炎症性肠病进程的有益尝试.     

炎症性肠病肠上皮细胞基质金属蛋白激酶对NAP-2的影响

目的:探讨肠上皮细胞基质金属蛋白激酶(MMPs)对中性白细胞化学趋化物NAP-2的影响及其与炎症性肠病炎症发生的关系．方法:培养Caco-2高分化人结肠癌上皮细胞和CCD-18细胞,分别加入人重组MMP-3、IL-1β、MMP抑制剂强力霉素、CT1399、CT1487和抗人NAP-2中性白细胞mAb,Caco-2和CCD-18细胞于37℃含50 mL／LCO2条件下培养24 h,进行化学趋化性试验．取克罗恩病(CD)和溃疡性结肠炎(UC)的肠黏膜切除标本作实验组．用RT-PCR方法检测Caco-2细胞和CD和UC的肠黏膜组织的PBP mRNA和MMPs mRNA:用ELISA和Western blot法分别检测Caco-2细胞和CD和UC的肠黏膜组织的NAP-2蛋白．结果:MMP-3明显增加IL-1β刺激的Caco-2细胞吸引外周中性白细胞的能力(U=24．60,P= 0．005;U=37．22,P=0．002);50μmol强力霉素和0．1μmol CT1847能显著抑制Caco-2细胞对中性白细胞的趋化性(U=15．18,P=0．01;U= 34．73,P=0．002);1 mg／L抗人NAP-2中性白细胞mAb能显著抑制Caco-2细胞对中性白细胞的化学趋化性(U=156．04,P=0．000)．RT-PCR分柝表明,MMP-1 mRNA,MMP-2 mRNA, MMP-3 mRNA和MMP-10 mRNARCCD-18细胞表达:PBP mRNA被Caco-2细胞和UC患者的肠黏膜表达．ELISA和Western blot法分析表明,NAP-2蛋白在活动性UC患者的肠黏膜明显增高,与CD的结果比较有显著性差异(U= 28．57,P=0．005)．结论:MMP能激发肠上皮细胞对中性白细胞的趋化反应,MMP通过激活中性白细胞化学趋化物NAP-2产生的免疫调节机制引起炎症性肠病肠上皮细胞炎症发生．     

炎症性肠病患者可溶性髓系细胞表达触发受体-1与环氧化酶-2的表达及其意义

目的研究炎症性肠病(IBD)患者肠黏膜可溶性髓系细胞表达触发受体(sTREM)-1与环氧化酶(COX)-2的表达,以及两者与溃疡性结肠炎患者病情严重程度和内镜分级程度的关系。方法分别采用流式细胞技术和免疫组化方法对50例IBD患者和20例对照组肠黏膜中sTREM-1和COX-2的表达进行测定。结果 50例IBD患者中,包括42例溃疡性结肠炎(UC)和8例克罗恩病(CD)患者。UC患者结肠黏膜中sTREM-1和COX-2的表达较对照组显著增高(P<0.05),且sTREM-1和COX-2在UC不同的病情分级及不同内镜分级中表达中有显著差异(F=19.055,P<0.05;F=34.119,P<0.05.F=54.617,P<0.05;F=58.608,P<0.05)。IBD患者结肠黏膜中sTREM-1和COX-2的表达呈正相关(r=0.642,P<0.05);UC患者结肠黏膜中sTREM-1的表达水平与患者病情程度及内镜分级呈正相关(r=0.945,P<0.05;r=0.944,P<0.05),COX-2的表达水平与患者病情程度及内镜分级亦呈正相关(r=0.944,P<0.05;r=0.944,P<0.05)。IBD患者肠黏膜中sTREM-1和COX-2的表达与对照组比较差异有统计学意义(P<0.05)。结论 sTREM-1和COX-2参与了IBD的发病过程,并且可以反映UC的炎症活动情况。     

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。     

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。     

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.     

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.