BISAP评分对急性胰腺炎严重程度及预后评估的临床价值

目的 通过与传统的急性胰腺炎(AP)病情评分系统比较,了解急性胰腺炎严重程度床边指数(BISAP)评分对AP严重程度及预后评估的临床价值.方法 回顾性分析2005年1月至2010年12月间收治的497例AP患者资料,分别进行BISAP、APACHEⅡ、Ranson及Balthazar CT( CTSI)评分,评估病情严重程度.应用受试者工作曲线下面积(AUC)比较BISAP评分与其他各评分系统对AP严重程度及胰腺坏死、器官功能衰竭、患者病死发生的预测能力.结果 497例患者中重症急性胰腺炎(SAP) 101例,轻症急性胰腺炎(MAP) 396例,MAP组和SAP组患者的年龄、性别、病因分布差异无统计学意义.497例患者的BISAP评分、APACHEⅡ评分、Ranson评分的平均分值分别为(1.08±1.01)、(5.79±4.00)、(1.69±1.59)分,两两相关(r值分别为0.612、0.568、0.577,P值均＜0.001).此外,SAP患者的BISAP评分、APACHEⅡ评分、Ranson评分的分值均显著大于MAP患者(P值均＜0.01).BISAP评分预测SAP的AUC值为0.762( 95％ CI 0.722～0.799),阳性截止(cutoff)值为2分,敏感性、特异性、阳性预测值、阴性预测值分别为63.4％、83.1％、48.1％、89.4％;预测胰腺坏死的AUC值为0.711(95％CI0.612～0.797),cutoff值为2分,敏感性、特异性、阳性预测值、阴性预测值分别为84.6％、46.7％、35.5％、89.7％;预测器官衰竭的AUC值为0.777(95％ CI0.683 ～0.854),cutoff值为2分,敏感性、特异性、阳性预测值、阴性预测值分别为93.1％、51.4％、43.5％、94.9％;预测患者病死的AUC值为0.808(95％ CI 0.718 ～0.880),cutoff值为3分,敏感性、特异性、阳性预测值、阴性预测值分别为83.3％、67.4％、25.6％、96.8％.BISAP评分与其他评分系统预测SAP各预后指标的差异均无统计学意义.结论 BISAP评分对AP严重程度及预后的评估价值与其他传统的评分系统相同,但其只有5项指标,且均可在入院24h内采集,可以早期、简便地预测SAP,值得在临床推广应用.     

急性胰腺炎床旁严重度指数和无害性胰腺炎评分对急性胰腺炎预后的评估价值

目的 评价急性胰腺炎床旁严重度指数(BISAP)与无害性胰腺炎评分(HAPS)评估急性胰腺炎(AP)预后的价值.方法 回顾性分析2003年1月至2010年12月中山大学附属第一医院收治的442例AP患者资料,计算BISAP和HAP评分,绘制受试者工作特征(ROC)曲线并计算曲线下面积(AUC),分析它们对AP严重度、局部并发症、器官功能不全、预后的评估价值,并与传统的Ranson评分进行比较.结果 442例AP患者中,73例(16.5％)为重症急性胰腺炎(SAP).BISAP评分预测SAP、局部并发症、器官功能不全、病死结局的AUC分别是0.90(95％ CI:0.86～ 0.93)、0.82(95％ CI:0.76～0.89)、0.93(95％ CI:0.89 ～0.96)、0.93(95％ CI:0.87 ～0.98).BISAP评分和Ranson评分上述4项指标的AUC差异无统计学意义.HAP评分预测轻症急性胰腺炎(MAP)的特异性为85％,阳性预测值95％,AUC为0.73(95％CI:0.67 ～ 0.79).将BISAP和HAP评分相结合,2种评分均异常的患者发生不良结局的风险逐渐升高.结论 BISAP评分对AP预后的评估价值与Ranson评分相当,但更为简便.HAP评分能简单且准确地预测MAP的预后,BISAP和HAP评分相结合有助于更好地判断AP患者的预后.     

急性胰腺炎不同评分体系在新分类标准中的再评价

目的重新评价BISAP、APACHEⅡ、CTSI等评分体系对急性胰腺炎(acute pancreatitis,AP)新分类内重度急性胰腺炎(severe acute pancreatitis,SAP)的评价价值。方法收集2013年9月至2014年10月北京协和医院收治的136例AP患者临床资料及入院BISAP、CTSI、APACHEⅡ、SIRS、Glasgow、Ranson评分,评估各评分体系与新分类的相关性,用ROC曲线分析各评分预测病情严重程度的准确性,并评价其对预后的判断价值。结果 (1)136例AP患者中,轻度急性胰腺炎组50例(36.8%),中度重症胰腺炎组61例(44.9%),重症胰腺炎组25例(18.4%)。(2)BISAP、APACHEⅡ、CTSI评分与疾病严重程度相关(P0.05)。(3)BISAP、APACHEⅡ和CTSI评分对新分类中SAP预测准确性AUC值分别为0.904、0.942和0.823,最佳预测值分别为3分(敏感度84%,特异度86.5%,阳性似然比6.216,阴性似然比0.185)、10分(敏感度96%,特异度86.5%,阳性似然比7.104,阴性似然比0.046)和4分(敏感度96%,特异度56.8%,阳性似然比2.220,阴性似然比0.070)。(4)BISAP评分与疾病复发相关(P0.05)。结论 BISAP、APACHEⅡ、CTSI评分与新分类相关性较好,其中BISAP、APACHEⅡ评分对SAP的预测最为准确,BISAP≥3分或APACHEⅡ≥10分提示SAP。     

BISAP评分对急性胰腺炎患者病情严重度及预后评估价值的研究

目的研究BISAP评分系统对急性胰腺炎(AP)患者病情严重程度及预后指标包括住院天数、有无局部并发症、全身并发症、器官衰竭及治疗转归等的评估价值,并与既往经典评分Ranson、CTST进行比较。方法采用回顾性临床研究方法,研究2001年2月-2011年11月上海市第一、第十人民医院及松江区中心医院收治的急性胰腺炎病例707例,对所有急性胰腺炎患者进行BISAP、Ranson和CT评分。受试者工作曲线(ROC曲线)分析三种评分系统对急性胰腺炎严重程度及预后的评估价值。结果 707例急性胰腺炎患者中急性轻型胰腺炎613例,急性重型胰腺炎94例。BISAP评分对急性胰腺炎轻重、局部并发症、全身并发症、器官衰竭及死亡的受试者工作曲线下面积(AUC)分别为0.77、0.68、0.83、0.83、0.88。对急性胰腺炎死亡的判断,BISAP及Ranson评分均有较好的独立预测价值,优于CTSI评分。结论 BISAP评分对急性胰腺炎轻重分型、局部并发症、全身并发症和器官衰竭的发生及死亡均有较强的预测价值,与平均住院天数呈正相关;对急性胰腺炎死亡有独立预测价值,且时效性强,可以在急性胰腺炎发病早期发现重症趋势。     

BISAP评分系统对重症急性胰腺炎的评估价值

目的 探讨新型BISAP评分体系(bedside index for severity in AP)对重症急性胰腺炎(SAP)的评估价值。方法 选取临床拟诊为SAP的患者68例,分别进行BISAP、APACHEⅡ、Ranson以及CTSI评分。BISAP评分标准包括患者入院24h内的尿素氮水平、受损精神状态、全身炎症反应综合征、年龄、胸腔积液5项内容。以BISAP≥3分、APACHEⅡ≥8分、Ranson≥3分、CTSI≥3分为SAP的评估标准,分析这几种评分系统评估SAP的正确率。结果 68例患者中,BISAP≥3分者43例,占63.2％;APACHEⅡ≥8分者41例,占60.3％;Ranson≥3分者41例,占60.3％;CTSI≥3分者46例,占67.6％。BISAP评分系统与APACHEⅡ评分系统、Ranson评分系统以及CTSI评分系统比较,评估SAP的正确率均无显著性统计学差异。结论 BISAP评分系统作为一种新型的、简便的评分体系可推广应用于SAP的评估。     

血清脂肪酶联合Ranson或BISAP评分系统诊断急性胰腺炎严重程度的效果分析

目的探讨血清脂肪酶联合Ranson或BISAP评分系统在急性胰腺炎严重程度中的诊断意义。方法选取2012年2月-2015年2月惠东县第二人民医院收治的急性胰腺炎患者314例,分为轻症急性胰腺炎(MAP)组(n=202)和重症急性胰腺炎(SAP)组(n=112)。对所有患者分别进行血清脂肪酶检测、Ranson评分、BISAP评分、脂肪酶联合Ranson或BISAP评分。计量资料组间比较采用t检验,计数资料组间比较采用χ2检验,不同评估方法间曲线下面积(AUC)、约登指数比较采用Z检验。结果 SAP患者的血清脂肪酶水平、Ranson评分值、BISAP评分值均显著高于MAP患者,差异均有统计学意义(t值分别为14.89、11.89、5.12,P值分别为0.003、0.007、0.037)。预测器官功能衰竭、胰腺坏死和病死率的AUC中,脂肪酶联合BISAP评分系统均高于BISAP评分,差异均有统计学意义(Z值分别为7.54、7.11、7.57,P值分别为0.033、0.031、0.030);脂肪酶联合Ranson评分系统均高于Ranson评分,差异均有统计学意义(Z值分别为5.23、5.78、6.18,P值分别为0.037、0.034、0.032);脂肪酶联合BISAP评分系统均高于脂肪酶联合Ranson评分系统,差异均有统计学意义(Z值分别为13.55、8.33、7.66,P值分别为0.005、0.029、0.031)。脂肪酶联合Ranson评分系统预测器官功能衰竭、胰腺坏死和病死率的约登指数均高于Ranson评分,差异均有统计学意义(Z值分别为5.17、6.89、7.35,P值分别为0.038、0.032、0.027);脂肪酶联合BISAP评分系统的约登指数均高于BISAP评分,差异均有统计学意义(Z值分别为7.54、7.22、9.57,P值分别为0.030、0.031、0.025),脂肪酶联合BISAP评分系统的约登指数均高于脂肪酶联合Ranson评分系统,差异均有统计学意义(Z值分别为10.11、10.23、13.24,P值分别为0.020、0.019、0.010)。结论脂肪酶联合Ranson或BISAP评分系统在诊断急性胰腺炎严重程度时较单独采用Ranson评分系统、BISAP评分系统准确性高,其中脂肪酶联合BISAP评分系统敏感性更高,更具有临床诊断价值。     

NLR联合甘油三酯葡萄糖体脂质量指数对急性胰腺炎患者重症的预测价值

目的 探讨中性粒细胞/淋巴细胞比值（NLR）联合甘油三酯葡萄糖体脂质量指数（TyG-BMI）对急性胰腺炎（AP）患者重症的预测价值。方法 AP患者425例，根据是否为重症AP(SAP)将患者分为SAP组25例与非SAP组400例。计算两组NLR与TyG-BMI并进行AP严重程度床边指数（BISAP）评分、Ranson评分、CTSI评分。采用Spearman检验分析SAP组NLR、TyG-BMI与各项临床指标的相关性。采用受试者工作特征曲线下面积（AUC）分析NLR、TyG-BMI及不同AP病情评分系统对SAP的预测效能。结果 SAP组NLR、TyG-BMI、Ranson评分、CTSI评分、BISAP评分均高于非SAP组（P均<0.05）。SAP组NLR与年龄、亚特兰大分类、乳酸脱氢酶、WBC、中性粒细胞计数（NEUT）、ALT、AST、谷氨酰转肽酶、空腹血糖（GLU）、血肌酐（Cr）及高血压病史呈正相关（P均<0.05）;TyG-BMI与亚特兰大分类、吸烟、饮酒、BMI、甘油三酯、WBC、NEUT、GLU、总胆固醇及糖尿病、高脂血症、脂肪肝病史呈正相关，与性别、年龄、高密度...     

细胞因子联合BISAP评分系统早期预测急性胰腺炎严重程度及预后的前瞻性研究

目的分析细胞因子白介素6(IL-6)联合急性胰腺炎严重程度床边指数(BISAP)早期(病程48 h)预测急性胰腺炎预后的临床价值。方法前瞻性选取2013年3月至2014年9月我院收治的确诊为急性胰腺炎(AP)的患者。所有患者入院时即抽取空腹静脉血测定IL-6,采用Ranson评分系统、BISAP评分以及IL-6联合BISAP评分判断胰腺炎患者预后,比较各评分系统的灵敏度以及特异度。结果共84例患者纳入本前瞻性研究,其中SAP 26例,MAP 58例。IL-6联合BISAP评分预测急性胰腺炎患者器官功能衰竭、胰腺坏死优于Ranson评分(P0.05)及BISAP评分;三种评分系统对于预测患者死亡方面无显著差异(P0.05)。结论细胞因子IL-6联合BISAP评分系统对早期预测急性胰腺炎严重程度及预后更有价值。     

不同评分系统对判断急性胰腺炎病情及预后的比较研究

目的比较PANC3、SIRSS、HAPS、Ranson’s、CTSI评分对急性胰腺炎(acute pancreatitis,AP)病情严重程度的评估价值,为AP诊治、改善预后提供临床依据。方法回顾性分析昆明医科大学第二附属医院消化内科2013年1月至2016年12月收治的121例AP患者临床资料,计算PANC3、SIRSS、HAPS、Ranson’s、CTSI评分,绘制受试者工作特征曲线(ROC),比较各评分对SAP、局部并发症、全身并发症、死亡的预测价值。结果 MAP组、MSAP组及SAP组5种评分均数比较,差异均有统计学意义(P均0.05),SAP组分值显著高于MAP组及MSAP组;PANC3、SIRSS、HAPS、Ranson’s、CTSI评分与AP病情严重程度有显著相关性(P0.05),HAPS评分与SAP无相关性(P0.05),HAPS评分预测MAP的准确度为90.5%。对预测SAP方面,PANC3评分AUC值、约登指数、敏感度高于其他评分。在预测AP局部并发症方面,CTSI评分AUC值、约登指数、敏感度和特异度高于其他评分。在预测AP全身并发症和死亡方面,Ranson’s评分AUC值、约登指数均高于其他评分。在评估局部并发症、全身并发症、死亡的发生率方面,PANC3≥2分、SIRSS≥2分、Ranson’s≥3分、CTSI≥4分组所占例数均显著高于PANC32分、SIRSS2分、Ranson’s3分、CTSI4分组。结论 Ranson’s评分对预测AP全身并发症和死亡率的诊断价值及准确度高于其他评分,在预测AP局部并发症中CTSI评分诊断价值有显著优势,PANC3评分对预测SAP诊断价值优于其他评分,HAPS对评价MAP准确度更高。     

急性胰腺炎早期联用BISAP评分及血清CRP、TNF-α评估患者病情及预后的临床价值

目的分析急性胰腺炎(acute pancreatitis,AP)早期联用AP严重程度床边指数(BISAP)评分、血清C反应蛋白(CRP)、肿瘤坏死因子-α(TNF-α)评估患者病情及预后的临床价值。方法选取中国医科大学航空总医院2013年8月-2015年8月收治的117例AP患者,按照病情分为轻症AP(MAP)组(n=61)及重症AP(SAP)组(n=56),并选取同期50名健康体检者纳入对照组。比较AP患者BISAP评分,并检测三组受试者血清CRP、TNF-α,分析上述指标评估AP患者预后的临床价值。结果 MAP组患者BISAP评分低于SAP组患者,差异有统计学意义(P0.05)。SAP组血清CRP水平、TNF-α水平高于MAP组,MAP组高于对照组,差异均有统计学意义(P0.05)。死亡患者BISAP评分高于器官衰竭患者,器官衰竭患者高于胰腺坏死患者,差异均有统计学意义(P0.05)。ROC示,BISAP评分预测SAP患者、死亡患者的AUC分别为0.848、0.891。Pearson相关性分析示,BISAP评分与血清CRP、TNF-α水平均呈正相关,CRP与TNF-α水平呈正相关(P0.05)。结论 BISAP评分可有效评估AP患者病情及预后,联合血清CRP、TNF-α水平可进一步了解病情进展状态,提高评估的准确性。     

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.