替加色罗治疗糖尿病胃轻瘫的临床观察

目的探讨替加色罗治疗糖尿病胃轻瘫（13（3）的临床价值。方法将67例确诊为13（3的病人随机分为两组，即替加色罗组和吗丁啉组。替加色罗治疗组36例，与吗丁啉治疗组31例进行比较，并采用实时B超测定胃半排空时间（EGt1／2）。结果替加色罗治疗13（3总有效率及对便秘的疗效均高于吗丁啉组（P〈0．05或0．01），两组治疗后EGt1／2均明显缩短（P〈0．001），但替加色罗组对胃排空障碍的疗效显著优于吗丁啉（P〈0．001）。结论替加色罗是治疗DG尤其是伴有便秘者的较好药物。     

马来酸曲美布汀治疗功能性消化不良与腹泻型肠易激综合征重叠的随机对照研究

目的 观察马来酸曲美布汀片（曲美布汀）治疗功能性消化不良（FD）与腹泻型肠易激综合征（IBS—D）重叠的疗效和不良反应。方法 采用随机、病例对照的前瞻性研究,129例患者随机分为A组（曲美布汀和地衣芽孢杆菌）、B组（曲美布汀）和C组（地衣芽孢杆菌）。各症状采用分级记分进行描述,疗效评价参照症状积分的变化。结果 A、B组治疗前后的评分,分别为腹胀[A组（4．55±0．85）分,（1．26±0．52）分;B组（4．36±0．66）分,（1．48±0．61）分]、早饱[A组（4．05±0．96）分,（1．01±0．51）分;B组（3．89±0．81）分,（1．25±0．76）分]、腹痛[A组（9．26±0．68）分,（0．68±0．43）分;B组（9．57±1．60）分,（0．76±0．54）分],症状总积分[A组（20．00±1．25）分,（3．06±0．91）分;B组（19．05±2．28）分,（3．89±2．12）分],治疗后较治疗前均有显著下降（P〈0．05）,而C组治疗前后差异无统计学意义（P〉0．05）;3组治疗前后的腹泻评分[A组（4．78±0．76）,（0．65±0．53）;B组（4．13±0．65）,（1．25±0．62）;C组（4．65±0．88）,（1．45±0．70）]均有显著性下降（P〈0．05）。治疗4周后,腹胀、早饱、腹痛的评分和症状总积分,A、B组与C组比较,差异有统计学意义（P〈0．05）。A、B组的各症状的疗效和总疗效均优于C组（P〈0．05）。3组的费用一效果比（C／E）分别为4．07、1．19、6．65,以B组最佳。A、B组的不良反应发生率分别为22．9％和23．7％,主要为轻度的口干和便秘。结论 曲美布汀治疗FD与IBS—D重叠的患者,具有疗效高,价廉,不良反应少的特点。     

小剂量替加色罗治疗功能性消化不良临床研究

目的探讨小剂量替加色罗治疗功能性消化不良的疗效。方法选择功能性消化不良病人92例，随机分为治疗组和对照组。治疗组给予马来酸替加色罗3mg，2次／d；对照组给予枸檬酸莫沙必利5mg，3次／d，餐前0．5h口服。两组均4周为l疗程。在用药前及每周随访1次记录症状，以治疗前与治疗后第4周的症状变化判断药物的临床疗效。结果两组病人功能性消化不良症状均能显著缓解，但组上腹不适、餐后饱胀的改善分别达到89.13％和94．65％，明显优干对照组(P＜0.05)。结论小剂量替加色罗治疗功能性消化不良既取得良效，又避免了以常规剂量治疗可能引起的腹泻副作用，效果确切，无明显副作用，值得在临床进行更大规模的研究，其远期疗效也有待进一步观察。     

剔除过敏食物治疗肠易激综合征的疗效观察

目的探讨依据食物特异性抗体IgG（SIgG）,剔除过敏食物治疗肠易激综合征（IBS）的疗效,进一步证实食物过敏在IBS发病中的作用。方法取腹泻型IBS（D—IBS）患者55例、便秘型IBS（C—IBS）患者32例和健康对照18例的静脉血,应用酶联免疫方法检测14种SIgG。对35例SIgG抗体升高的IBS患者,剔除过敏食物治疗2个月,观察治疗前后患者症状频率和程度的变化以及IBS专用生活质量量表（IBS QOL）积分的改变。结果D—IBS患者SIgG抗体的阳性率为63．6％（35／55）,C—IBS患者SIgG抗体的阳性率为43．8％（14／32）,二者均高于对照组。依据SIgG抗体剔除过敏食物治疗2个月,31．4％的患者症状完全缓解,34．3％的患者症状明显缓解。剔除过敏食物4周后,IBS患者的症状频率、严重程度积分分别由（3．79±1．58）次／周降至（1．67±0．70）次／周,3．18±1．46降至1．52±0．67;8周后,分别由（3．79±1．58）次／周降至（1．53±0．69）次／周,3．18±1．46降至1．45±0．66,差异均有统计学意义（P〈0．05）。IBS QOL 8个维度积分除挑食外其他积分和总体健康积分均比治疗前显著升高。结论IBS患者存在食物特异性IgG抗体介导的免疫异常反应,根据SIgG水平剔除过敏食物治疗IBS是有意义的。     

中国医生胃食管反流病诊治状况的调查研究

的了解中国不同地区医生胃食管反流病（GERD）的发病和诊治情况。方法中国医师协会消化医师分会采用随机抽样问卷方式，于2006年2月-6月在全国不同地区医院中对患有GERD的医生的发病和诊治情况进行调查。结果1010例患有GERD的医生接受调查，男性567例、女性419例，男女性别比为1．35：1，平均年龄为（41．1±10．3）岁，其中患病年龄以30～40岁最为多见。在胃食管反流症状中烧心502例（49．7％），胸骨后痛325例（32．2％），暖气319例（31．6％），上腹痛313例（31．1％），咽部吞咽异物感88例（8．7％）。在被调查对象中467例（46．2％）曾行胃镜检查，食管黏膜正常者339例，占76．0％；反流性食管炎102例，占21．8％；Barrett食管10例，占2．2％。89．3％的被调查者曾服用质子泵抑制剂（PPI）治疗，平均起效时间为（13．2±36．5）h，服用药物的满意度为91．0％。相关分析显示年龄及性别与胃镜检查结果无相关性，临床症状及其严重程度与胃镜检查结果亦无相关性。回归分析显示症状缓解时间（P=0．0065）及服药方式（P=0．0003）与服用药物满意度存在负相关。结论患有GERD的中国医生临床症状主要表现为烧心、胸骨后痛、暖气和上腹痛，胃镜检查是诊断反流性食管炎的重要依据，多数被调查者胃镜下表现为食管黏膜正常，选择服用PPI治疗疗效的满意度高。     

替加色罗治疗便秘型肠易激综合征的多中心临床研究

目的　通过患者对肠易激综合征 (IBS)症状的总体评估和对每个IBS症状的个别评估以及不良反应观察 ,评估替加色罗 6mg每日 2次治疗便秘型肠易激综合征 (C IBS)的疗效与安全性。方法　本研究是一项多中心、随机、双盲、平行、安慰剂对照临床研究。入选 51 0例符合罗马Ⅱ标准的C IBS患者 ,试验为期 8周 ,包括 2周基线期 ,4周替加色罗 6mg每日 2次或安慰剂 (替加色罗∶安慰剂=1∶1 )随机、双盲治疗期及 2周停药随访期。评估标准 :对患者全部IBS症状进行总体评估 ,对患者每个IBS参数 (包括便秘严重程度 )以及安全性进行评估。结果　替加色罗组患者总体IBS症状的主要疗效参数从第 1周开始至整个治疗期均有显著改善。替加色罗组其他IBS疗效参数 (如便秘、腹痛、腹部不适、腹胀 )评分从第 1周开始至整个治疗期仍均优于安慰剂组。说明替加色罗疗效更明显。在停药随访期 ,替加色罗组和安慰剂组各疗效参数评分虽有所降低 ,但相对于基线期仍均有所改善 ,但前者疗效明显优于后者 ,提示替加色罗的疗效至少可持续到停药后 2周。替加色罗组和安慰剂组发生不良事件的比例分别为 1 0 %和 6 %。替加色罗组最常见的不良事件为腹泻、腹痛和头晕 ,但发生率均较低 (<3 % )。实验室检查未发现异常。结论　替加色罗 6mg每日 2次能     

替加色罗对便秘型肠易激综合征大鼠模型肠道功能和中枢c-fos表达的影响

目的研究替加色罗对便秘型肠易激综合征（C-IBS）大鼠模型排便、肠道敏感性和中枢神经c-fos表达的影响。方法应用冰水灌胃方法建立C-IBS大鼠模型20只，随机分为替加色罗药物组（A组）和对照组（B组）。A组给予室温20％替加色罗溶液（2mL／只，1次／日）灌胃7d；B组给予等量室温生理盐水灌胃7d。观察灌胃期间两组大鼠灌胃后3h内和3～24h间的大便粒数及含水量变化，停止灌胃后继续观察7d内大便粒数及含水量变化。第14d实验结束后所有大鼠给予直肠内球囊扩张，检测球囊扩张引起腹部收缩反射的最小容量阈值及球囊不同容量扩张时腹部收缩反射的次数，以评价替加色罗对肠道敏感性的影响。脊髓、下丘脑及前扣带回c-los表达应用免疫组织化学染色及计算机图像分析系统半定量分析。结果两组大鼠灌胃后3h内大便粒数及含水量无明显差异（P〉0．05）；A组灌胃后3～24h间的大便粒数及含水量均较B组明显增加（P〈0.05）。直肠内球囊扩张时，A组引起腹部收缩的最小容量阈值略低于B组，无明显统计学差异（P〉0．05）。直肠球囊扩张体积1．0mL时A组腹部收缩反射次数高于B组（P〈0．05）；体积1.5mL、2．0mL高容量扩张时两组无明显差异（P〉0．05）。A组腰骶段脊髓背角、下丘脑和前扣带回的C-fos阳性神经元细胞的面积及OD值均明显低于B组（P〈0．05）。结论替加色罗能改善便秘型肠易激综合征大鼠模型的便秘和肠道敏感性，并减少脊髓、下丘脑及前扣带回c-fos的表达。     

非糜烂性胃食管反流病食管酸暴露和雷贝拉唑对其诊断价值研究

目的 研究非糜烂性胃食管反流病（NERD）各亚型食管酸暴露特点,探讨雷贝拉唑对其诊断价值。方法 32例NERD患者分成3组,异常酸反流组14例,食管对酸高敏组11例,功能性烧心组7例,并以雷贝拉唑10mg,2次／d治疗2周。结果 （1）各组酸暴露：异常酸反流组酸反流总次数、长反流次数、pH〈4时间及其百分比较其他两组明显增加;食管对酸高敏组症状指数显著高于功能性烧心组[（81．0±22．5）％比（8．6±14．8）％,P〈0．01]。（2）症状比较：各组间治疗前典型症状积分和总积分相比差异均无统计学意义;食管对酸高敏组患者食管外症状积分显著高于异常酸反流组患者（4．0±3．8比0．9±2．2,P〈0．05）。（3）疗效：异常酸反流组、食管对酸高敏组患者在雷贝拉唑治疗1、2周后均有食管外症状积分、总积分的显著下降;而功能性烧心组患者仅有下降趋势,与治疗前比较差异无统计学意义;异常酸反流组与其他两组治疗后2周比较,症状积分差异有统计学意义。（4）雷贝拉唑对NERD患者1、2周治疗后总体有效率分别为56．3％、68．8％;雷贝拉唑诊断试验对异常酸反流和食管酸高敏的敏感性和特异性,在1周时分别为64．0％、71．4％,在2周时分别为80．0％、71．4％。结论 （1）异常酸反流组酸暴露主要表现在酸反流的总次数、长反流次数增多,pH〈4时间延长。（2）食管对酸高敏患者可能更易发生食管外症状。（3）雷贝拉唑诊断试验对NERD有较好的诊断和分型价值。     

甲磺酸伊马替尼对大鼠肝纤维化及转化生长因子-β1表达的影响

目的研究甲磺酸伊马替尼在四氯化碳＋橄榄油肝纤维化模型中的抗纤维化作用及其对转化生长因子（TGF）-β1表达的影响。方法甲磺酸伊马替尼对照组大鼠（n=8）每周2次腹腔内注射橄榄油，每日予甲磺酸伊马替尼20mg／kg灌胃；正常对照组（n=8）每周2次腹腔内注射橄榄油，每日予生理盐水灌胃；肝纤维化模型组（n=12）每周2次腹腔内注射四氯化碳和橄榄油混合物，每日予生理盐水灌胃；甲磺酸伊马替尼干预组（n=12）每周2次腹腔内注射四氯化碳和橄榄油混合物，每日予甲磺酸伊马替尼20mg／kg灌胃。第8周末取动物肝中叶，Masson染色后测定胶原面积，a-SMA免疫组化染色后定量活化肝星状细胞（HSC）。反转录（RT）-PCR法测定TGF-β1、c-Ab1和金属蛋白酶组织抑制因子（TIMP）-1mRNA表达，Western印迹检测肝组织磷酸化血小板衍化生长因子（PDGF）β受体和TGF-β1蛋白表达，免疫组化检测TGF-β1、c-Ab1表达。测定肝羟脯氨酸含量。结果与肝纤维化模型组比较，甲磺酸伊马替尼干预组肝组织胶原面积和活化HSC数分别减少35％和20％[分别为（25．61±0．92）％比（16．23±1．01）％和13．10±1．21比10．52±1．33，P值均〈0．05]；TGF-β1、c-Ab1和TIMP-1的表达均较肝纤维化模型组有明显下降（0．54±0．08比0．93±0．12，0．33±0．06比0．87±0．11，0．59±0．09比0．87±0．12，P值均〈0．05）；肝组织羟脯氨酸含量（0．26±0．10）mg／g较肝纤维化模型组（0．39±0．08）mg／g有显著下降（P〈0．01）。结论甲磺酸伊马替尼可通过抑制HSC增殖和细胞外基质沉积缓解肝纤维化，并抑制TGF-β1的表达和促纤维化活性。     

基因多态性与肠易激综合征的关系及其对药效的影响

目的探讨5-羟色胺转运体（SERT）基因启动子区域（5-HTTLPR）与第2内含子可变数目串联重复序列（VNTRs）多态性在正常人及肠易激综合征（IBS）患者的分布及对替加色罗治疗便秘型IBS（C-IBS）疗效的影响。方法用PCR检测87例IBS和96例对照者外周血2个基因的多态性;给予41例C-IBS患者4周替加色罗6mg,2次／d,治疗前后评估临床症状及便秘程度。结果IBS组5-HTTLPR基因型频率是S／S：52．9％,S／L：31．0％,L／L：16．1％;对照组分别为57．3％,35．4％及7．3％;IBS组VNTRs基因型频率是STin2．10／10：2．3％,STin2．12／10：17．2％,STin2．12／12：80．5％;对照组分别为2．1％,11．4％及86．5％;两组差异无统计学意义（P〉0．05）,但C-IBS组的I／L频率比对照组显著高（25.0％比7.3％,P〈0．05）。治疗后症状缓解率S／S型为85.0％,S／L型为70．0％,均显著优于L／L型的36．4％（P〈0．05）;主体症状评分和单个症状（排便次数、粪便性状、便后排空感等）改善在S／S和L／S型均优于L／L型（P〈0．05）。结论SERT基因多态性总体与IBS发病无关,但L／L型更易患C-IBS。替加色罗对C—IBS的疗效受基因型影响,L／L型疗效较差。     

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.