一种简易牵引装置在结肠内镜黏膜下剥离术中的临床应用（含视频）

评估在结肠内镜黏膜下剥离术（endoscopic submucosal dissection,ESD）中,金属夹联合丝线和橡皮圈作为简易内牵引装置的临床应用价值。以2021年1月至2022年7月间,在南通大学附属江阴医院进行ESD治疗的56例早期结肠癌和癌前病变患者为研究对象,采用计算机软件随机分配,分为常规ESD治疗的对照组（n=28）和金属夹联合丝线及橡皮圈牵引的牵引组（n=28）。对两组患者的ESD手术总时间、黏膜剥离时间、黏膜下注射次数、完整切除病灶率、手术并发症等情况进行综合比较。结果牵引组手术总时间较对照组短［（74.64±33.25）min比（117.18±35.75）min,t=4.61,P<0.001］;牵引组黏膜剥离时间较对照组短［（51.61±24.87）min比（99.11±32.73）min,t=6.11,P<0.001］;牵引组黏膜下注射次数较对照组少［（1.68±1.16）次比（4.96±1.41）次,t=9.57,P<0.001］;两组患者在手术面积和完整切除率及手术并发症方面差异无统计学意义（P>0.05）。可见,金属夹联合丝线及橡皮圈的作为牵引辅助装置,可以降低结肠ESD的技术难度,缩短手术时间。     

牙线牵引辅助内镜黏膜下剥离术治疗胃角黏膜病变的疗效（含视频）

目的 探讨牙线牵引辅助内镜黏膜下剥离术（endoscopic submucosal dissection, ESD）治疗胃角黏膜病变的疗效。方法 回顾性分析2015年1月—2018年12月厦门大学附属第一医院内镜中心收治的127例胃角黏膜病变患者病例资料。根据术中手术方法,将患者分为牙线牵引辅助ESD组（牵引组,n=51）和传统ESD组（传统组,n=76）,同时把41例胃角纤维化病例也分为牵引组(n=23)和传统组(n=18)。对比分析手术时间、整块切除率、治愈性切除率及出血、肌层损伤、穿孔等不良事件发生率等指标。结果 牵引组与传统组病例年龄、性别、病变大小及病变形态差异无统计学意义（P＞0.05）。牵引组手术时间较传统组明显缩短[（65.4±36.5） min比(103.5±43.2) min,P=0.012],病变整块切除率[100.00%(51/51)比90.79%(69/76),P=0.026]及治愈性切除率均更高[94.12%(48/51)比81.58%(62/76),P=0.042],且剥离过程中肌层损伤[5.88%(3/51)比25.00%（19/76）,P=0.010]及术中出血更少[47.06%（24/51）比82.89%（63/76）,P=0.010]。传统组2例(2.63%)纤维化病例穿孔,牵引组无穿孔病例,穿孔发生率差异无统计学意义（P=0.243）。在胃角纤维化病例中,牵引组手术时间较传统组明显缩短[（81.4±29.3） min比(119.3±37.6） min,P=0.010],病变整块切除率[100.00%（23/23）比72.22%(13/18）,P=0.007]及治愈性切除率均更高[95.65%(22/23)比72.22%(13/18),P=0.035],且剥离过程中肌层损伤[8.70%(2/23)比72.22%(13/18）,P=0.001]及术中出血更少[78.26%(18/23)比100.00%(18/18),P=0.035]。结论 牙线牵引辅助ESD治疗胃角黏膜病变及有纤维化的胃角病变安全有效,与传统ESD相比,手术时间更短,治愈率更高,不良事件发生率更低。     

带线钛夹在胃异位胰腺内镜黏膜下剥离术中的应用价值

目的评价带线钛夹辅助牵引技术在胃异位胰腺内镜黏膜下剥离术（ESD）治疗中的使用效果和安全性。方法2013年5月至2016年2月,在第三军医大学新桥医院消化内科行ESD治疗,且术后病理确诊的62例胃异位胰腺（均为单发黏膜下来源）患者的病例资料纳入回顾性分析,对比分析使用带线钛夹辅助牵引技术组（观察组,n=36）和传统ESD组（对照组,n=26）的剥离时间、剥离过程中黏膜下层的暴露情况、并发症发生情况及随访结果。结果62例均成功施行ESD治疗。剥离时间观察组明显短于对照组［（19.35±10.34）min比（27.02±14.27）min,t′=2.333,P=0.023］,并且剥离过程中黏膜下层的暴露效果观察组优于对照组。出血发生率观察组为55.6％（20／36）,对照组为61.5％（16／26）,组间差异无统计学意义（χ2=0.222,P=0.638）。观察组无一例发生穿孔,对照组发生1例（3.8％,1／26）,组间差异无统计学意义（P=0.419）。随访期间,62例均无复发。结论ESD治疗胃异位胰腺安全有效,剥离过程中使用带线钛夹辅助牵引技术可有效缩短手术时间,并且有利于减少手术相关并发症的发生。     

新型牵引装置在结直肠侧向发育型肿瘤内镜黏膜下剥离术中的有效性研究

目的 研究新型牵引装置在结直肠侧向发育型肿瘤（laterally spreading tumor,LST）内镜黏膜下剥离术（endoscopic submucosal dissection,ESD）中的有效性。 方法 收集2018年8月—2020年4月首都医科大学附属北京朝阳医院内镜中心经ESD治疗的结直肠LST患者资料,根据手术过程中是否使用牵引,分为传统ESD组（不使用牵引）及牵引辅助ESD组（利用3个夹子和1个橡皮圈组成弹性三角形牵引装置进行牵引）。分析两组总切除时间、黏膜下剥离时间、黏膜下剥离速率以及安全性等相关指标。 结果 共纳入54例结直肠LST患者,其中29例为传统ESD组,25例为牵引辅助ESD组。两组年龄、性别构成、病变位置比较差异均无统计学意义（P>0.05）。牵引辅助ESD组的病变面积为13.30（7.55,15.91）cm2,较传统ESD组的6.90（5.50,13.50）cm2大,差异有统计学意义（U=503.50,P=0.014）。传统ESD组与牵引辅助ESD组总切除时间[48.00（35.50,58.00）min比34.00（29.00,35.00）min,U=109.00,P<0.001]和黏膜下剥离时间[（39.52±12.37） min比（25.68±7.37）min,t=4.89,P<0.001]比较差异有统计学意义。牵引辅助ESD组黏膜下剥离速率快于传统ESD组[0.17（0.13,0.30）cm2/min比0.52（0.30,0.62）cm2/min,U=604.00,P<0.001]。传统ESD组有2例（6.9%）穿孔,牵引辅助ESD无穿孔发生,但穿孔发生率比较差异无统计学意义（P=0.493）。 结论 利用夹子及橡皮圈进行牵引辅助的ESD相对于传统ESD治疗结直肠LST更加安全、有效。     

内镜黏膜下隧道法剥离术治疗胃角巨大黏膜病变的多中心回顾性研究

目的 评估内镜黏膜下隧道法剥离术（ESTD）在治疗胃角巨大黏膜病变中的应用价值。 方法 回顾性分析2014年7月至2016年7月在6家中心接受ESTD或内镜黏膜下剥离术（ESD）治疗的87例胃角大面积黏膜病变患者资料,其中ESTD组32例,ESD组55例。比较2组剥离时间、剥离速度、整块切除率、治愈性切除率、并发症及复发情况。 结果 ESTD组剥离时间较ESD组短［（87.3±32.6）min比（136.7±64.5）min,P＜0.01］,剥离速度明显快于ESD组［（0.18±0.07）cm2／min比（0.08±0.05）cm2／min,P＜0.01］,ESTD组较ESD组整块切除率［100％（32／32）比87.3％（48／55）,P=0.035］及治愈性切除率［100％（32／32）比85.5％（47／55）,P=0.024］高。ESD组术中均有出血发生,有8例出现肌层损伤;而ESTD组术中出血率仅59.4％（19／32）,且无肌层损伤发生（P均＜0.05）。2组复发率比较差异无统计学意义［0（0／32）比1.9％（1／54）,P=0.443］。 结论 ESTD在治疗胃角巨大黏膜病变时具有更高的剥除效率,同时可有效降低手术风险,减少并发症的出现,值得临床推广。     

经口牵引辅助下内镜黏膜下剥离术治疗早期胃癌及癌前病变的临床研究（含视频）

目的评估经口牵引辅助下内镜黏膜下剥离术（ESD）治疗早前胃癌及癌前病变的疗效和价值。方法2013年7月至2014年8月经胃镜及超声胃镜检查判断局限于黏膜层、未侵及固有肌层的早期胃癌及癌前病变患者44例,其中22例采用经口牵引辅助下ESD治疗（牵引组）,22例采用常规ESD治疗（对照组）,评估2组在病灶开始标记至完整剥离时间、黏膜暴露至完整剥离时间、单位时间切除率、操作困难部位切除时间、一次性整块切除率、一次性完整切除率、出血发生率、穿孔发生率等情况。结果牵引组较对照组,病灶开始标记至完整剥离时间[（48．13±14．65）min比（65．07±29．07）min,P〈0．05]、黏膜暴露至完整剥离时间[（37．47±14．17）min比（54．93±28．16）min,P〈0．05]、操作困难部位切除时间[（33．17±10．65）min比（54．53±46．92）min,P〈0．05]均明显缩短,单位时间切除率[（23．60±14．73）mm。／min比（13．62±8．11）mm。／min,P〈0．05]明显提高。2组一次性整块切除率、一次性完整切除率、出血发生率、穿孔发生率及容易操作部位切除时间相似（P〉0．05）,随访均未见局部复发。结论经口牵引辅助下ESD治疗早期胃癌及癌前病变可提高切除效率,对治疗早期胃癌及癌前病变具有较好的应用价值。     

新型磁力锚导引系统在内镜黏膜下剥离术中的应用:动物预实验

目的 评估新型磁力锚导引系统在猪模型内镜黏膜下剥离术（ESD）中的应用价值及安全性。方法 2名熟练ESD操作者在2只实验猪直肠进行磁力锚牵引辅助下ESD,记录分析操作时间、切除效率、完整切除率、并发症等。结果 共完成ESD操作5例,病灶开始标记至完整剥离平均时间为26.6 min,单位时间切除率（0.38±0.1）cm2/min。病灶均完整切除且无穿孔和迟发性出血发生。结论 磁力锚牵引辅助ESD能有效暴露黏膜下层,提供直视下切除,是一项安全有效的辅助技术。     

长节段早期食管癌及癌前病变内镜治疗的有效性及安全性评价

目的 分析病灶长度超过5 cm的早期食管癌及癌前病变行内镜黏膜下剥离术(ESD)与内镜分片黏膜切除术(EPMR)的疗效及安全性。方法 回顾性分析2012年1月至2017 年7月在福建省食管癌早诊早治促进联盟治疗的85例病灶长度超过5 cm的早期食管癌及癌前病变患者临床资料。根据术式不同,分为ESD组（52例）及EPMR组（33例）,对比两组疗效、并发症及随访情况。结果 ESD组与EPMR组的完整切除率相比差异无统计学意义[86.5%（45/52）比87.9%（29/33）,P>0.05],ESD组的手术时间[（58.53±30.50）min比（32.06±9.12）min]、术后禁食时间[（4.18±1.30）d比（3.67±0.96）d]、住院时间[（7.45±2.44）d比（6.54±1.73）d]及抗生素使用时间[（3.48±2.33）d比（1.96±2.20）d]明显长于EPMR组（P均<0.05）。ESD组与EPMR组的术中并发症发生率比较差异无统计学意义（P>0.05）;发热、胸痛、术后出血等近期术后并发症发生率对比差异亦无统计学意义（P>0.05）。ESD组术后狭窄发生率较EPMR组高[23.1%（12/52）比6.1%（2/33）,P<0.05]。术后随访3~63个月,ESD组复发5例,EPMR组1例,两者对比差异无统计学意义（P>0.05）。结论 EPMR与ESD治疗病灶长度超过5 cm的早期食管癌及癌前病变具有相同的有效性及安全性,而EPMR操作时间短,术后狭窄并发症少,且术式相对简单,易于掌握。     

内镜黏膜下隧道法剥离术治疗早期食管癌伴黏膜下层纤维化的临床观察

目的评价内镜黏膜下隧道法剥离术（endoscopic submucosal tunnel dissection,ESTD）治疗早期食管癌伴黏膜下层纤维化的效果和安全性。方法2015年6月—2018年2月间,在江苏省苏北人民医院消化内科采用ESTD或内镜黏膜下剥离术（endoscopic submucosal dissection,ESD）治疗,术后病理证实病灶＜1/3食管管周,且伴有黏膜下层纤维化的早期食管癌病例87例纳入回顾性分析,按纤维化程度分成轻度纤维化60例（ESTD 31例、ESD 29例）和重度纤维化27例（ESTD 16例、ESD 11例）,比较同一纤维化程度时两种手术方式的剥离速度、整块切除率、完全切除率,以及出血、肌层损伤、穿孔、颈部皮下气肿和术后狭窄的发生率。结果对于伴有轻度黏膜下层纤维化的早期食管癌患者,ESTD的整块切除率[96.8%（30/31）比82.8%（24/29）,P＜0.05]和完全切除率[96.8%（30/31）比75.9%（22/29）,P＜0.05]明显高于ESD,固有肌层损伤发生率明显低于ESD[6.5%（2/31）比17.2%（5/29）,P＜0.05],剥离速度、术中出血发生率、穿孔发生率、术后狭窄发生率与ESD比较差异均无统计学意义（P均＞0.05）,两种手术方式均无术后迟发性出血和颈部皮下气肿发生。对于伴有重度黏膜下层纤维化的早期食管癌患者,ESTD的剥离速度快于ESD[（12.3±2.8）mm2/min比（7.1±3.2）mm2/min],整块切除率、完全切除率、术后狭窄发生率与ESD相近,术中出血发生率[12.5%（2/16）比54.5%（6/11）]、固有肌层损伤发生率[18.8%（3/16）比54.5%（6/11）]、穿孔发生率[6.3%（1/16）比27.3%（3/11）]、颈部皮下气肿发生率[6.3%（1/16）比27.3%（3/11）]低于ESD,两种手术方式均无术后迟发性出血发生。术后12个月2例行ESD和1例行ESTD患者局部复发,术后24个月1例行ESTD患者发生异时癌。结论ESTD能安全、有效切除伴有黏膜下层纤维化的早期食管癌。对于伴有轻度黏膜下层纤维化者,ESTD的优势主要体现在治疗效果方面;对于伴有重度黏膜下层纤维化者,ESTD的优势主要体现在治疗安全性方面。     

内镜黏膜下剥离术中8字环辅助牵引的效果及安全性初探

为了评价内镜黏膜下剥离术（endoscopic submucosal dissection，ESD）中使用8字环辅助牵引的效果及安全性，2021年7月至2022年1月间，因胃部病变在南京大学医学院附属鼓楼医院行8字环辅助牵引下ESD治疗的总共13例病例（共15处病灶）纳入回顾性分析，结果显示13例均成功完成8字环辅助牵引下ESD，中位手术时间56 min，单位时间切除面积（0.20±0.02）cm2/min，病灶整块切除率93.3%（14/15），完全切除率80.0%（12/15），治愈性切除率80.0%（12/15），无术中及术后穿孔，无迟发性出血，无其他严重并发症及死亡病例。初步结果提示，8字环辅助牵引作为一种新型内牵引技术，操作简便，能够有效提高剥离效率，减少并发症发生，值得临床进一步研究和推广。     

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.