不稳定性心绞痛病人白细胞变形能力、粘附功能和白细胞CD18表达的变化

目的：探讨白细胞流变性、粘附性与急性心肌缺血的关系，为不稳定性心绞痛（ＵＡ）的治疗提供理论参考。方法：４７例不稳定性心绞痛病人，其中男２９例，女１８例。自发型心绞痛１６例，心肌梗死后心绞痛２２例，初发劳力型心绞痛９例。采用红细胞变形能力测定仪、血栓血小板粘附两用仪和酶联免疫吸附法（ＥＬＩＳＡ）分别检测了４０例健康人和４７例不稳定性心绞痛病人心绞痛发作期和缓解后２４小时的白细胞滤过指数（ＩＦ）、白细胞粘附率（ＬＡＲ）和白细胞不同组别第１８（ＣＤ１８）表达。结果：不稳定性心绞痛病人白细胞变形能力（ＬＤ）明显降低，白细胞粘附功能（ＬＡＦ）和白细胞ＣＤ１８表达明显增加（Ｐ＜０．００１，Ｐ＜０．０１），心绞痛发作时，ＬＤ降低和白细胞粘附功能、白细胞ＣＤ１８表达增高较心绞痛缓解后２４小时更明显（Ｐ＜０．００１），且白细胞滤过指数、白细胞粘附率和白细胞ＣＤ１８表达之间均呈正相关（Ｐ＜０．０１）。心绞痛发作时和缓解后２４小时，自发型心绞痛白细胞滤过指数、白细胞粘附功能和白细胞ＣＤ１８表达较心肌梗死后和劳力型心绞痛变化更明显（Ｐ＜０．０１）。结论：心肌缺血与白细胞流变性和粘附性改变有一定关系     

急性心肌梗塞病人血清sIL—2R水平,mIL—2R和T淋巴细胞亚群的变化

目的探讨急性心肌梗塞发病中免疫指标的变化。方法应用单克隆与多克隆双抗体夹心法检测６６例急性心肌梗塞（ＡＭＩ）病人发病后第１周内血清可溶性白细胞介素－２受体（ｓＩＬ－２Ｒ）的变化，同时检测外周血淋巴细胞膜白细胞介素－２受体（ｍＩＬ－２Ｒ）表达及Ｔ淋巴细胞亚群的变化。结果ＡＭＩ病人血清ｓＩＬ－２Ｒ明显增高，ｍＩＬ－２Ｒ表达明显降低，与对照组比较差异有极显著性意义（Ｐ＜０．００１）。发病后第１ｄ至第７ｄ，ｓＩＬ－２Ｒ增高和ｍＩＬ－２Ｒ表达降低一直比较明显。ＡＭＩ病人ＣＤ４、ＣＤ８和ＣＤ４／ＣＤ８明显低于对照组（Ｐ＜０．００１），以第１ｄ降低最明显，以后逐渐升高，ＣＤ８于第７ｄ恢复正常。４ｄ内死亡者和伴有室性心律失常（ＶＡ）者上述指标变化更明显。结论血清ｓＩＬ－２Ｒ水平、ｍＩＬ－２Ｒ表达和Ｔ淋巴细胞亚群变化与ＡＭＩ病情和预后有密切关系。     

糖尿病性血管病变与白细胞粘附功能和变形能力关系的研究

采用ＷＹＪ－Ⅲ型体外血栓血小板粘附两用仪和ＤＸＣ－３００型红细胞变形能力测定仪，测定了７７例ＮＩＤＤＭ病人白细胞粘附功能（ＬＡＦ）和白细胞变形能力（ＬＤ）的变化，以探讨其与糖尿病性血管病变发生的关系。结果显示，ＮＩＤＤＭ病人白细胞粘附率（ＬＡＲ）和白细胞滤过指数（ＩＦ）明显增高，与对照组相比差异有显著性（Ｐ〈０．００１），且有血管病变者变化比无血管病变者更明显。提示ＬＡＦ增高和ＬＤ降低可能参与了糖     

冠心病患者白细胞变形能力和粘附功能的动态变化

目的探讨白细胞变形能力（ＬＤ）和白细胞粘附功能（ＬＡＦ）与冠心病（ＣＨＤ）发病的关系。方法采用红细胞变形能力测定仪和血栓血小板粘附两用仪，检测４２例健康老年人和９２例老年ＣＨＤ患者白细胞滤过指数（ＩＦ）和白细胞粘附率（ＬＡＲ）早晚动态变化。结果两组中，ＩＦ和ＬＡＲ早晨较下午高（Ｐ＜００５及００１）；ＣＨＤ患者ＩＦ和ＬＡＲ较对照组明显增高（Ｐ＜００１），且以急性心肌梗死（ＡＭＩ）患者变化最明显。结论ＣＨＤ发病早晨高发现象与ＬＤ和ＬＡＦ动态变化有密切关系。     

哮喘气道炎症粘附机制的实验研究

目的评价细胞间粘附分子１（ＩＣＡＭ１）、Ｐ选择素在哮喘气道炎症粘附机制中的作用,进一步阐明哮喘的发病机理。方法用酶联免疫吸附试验、肺组织免疫组化检查和呼吸生理学方法系统观察正常组和哮喘组豚鼠各项指标。结果（１）哮喘组豚鼠肺潮气量、动态肺顺应性（Ｃｄｙｎ）和肺气道阻力与对照组比较差异有显著性（Ｐ＜０．０１及Ｐ＜０．０５）。（２）哮喘组豚鼠血浆和肺泡灌洗液（ＢＡＬＦ）可溶性ＩＣＡＭ１（ｓＩＣＡＭ１）、可溶性Ｐ选择素、血清和ＢＡＬＦ嗜酸粒细胞阳离子蛋白（ＥＣＰ）与对照组比较,差异有显著性（Ｐ＜０．０１）;ＢＡＬＦ中白细胞介素８（ＩＬ８）与对照组比较差异也有显著性（Ｐ＜０．０１）。（３）哮喘组豚鼠肺组织（气道上皮和血管内皮）ＩＣＡＭ１和ＩＬ８表达与对照组比较,差异有显著性（Ｐ＜０．０１）。结论ＩＣＡＭ１、Ｐ选择素、ＩＬ８、ＥＣＰ参与介导了哮喘气道炎症的粘附过程     

干扰素对人甲状腺细胞表面抗原表达的影响

目的研究干扰素（ＩＦＮα、ＩＦＮγ）及激素对人正常甲状腺细胞表面抗原表达的影响,以探讨ＩＦＮα导致自身免疫性甲状腺病（ＡＩＴＤ）的可能机制。方法应用ＩＦＮα、ＩＦＮγ、促甲状腺激素（ＴＳＨ）及催乳素（ＰＲＬ）,刺激体外培养的来自６名正常人的甲状腺细胞,通过免疫荧光染色及流式细胞仪测定其表面抗原—ＨＬＡＤＲ、细胞间粘附分子１（ＩＣＡＭ１）、Ｂ７．１和甲状腺过氧化物酶（ＴＰＯ）的表达。结果（１）ＩＦＮα明显诱导甲状腺细胞表达ＩＣＡＭ１、Ｂ７．１和ＴＰＯ（分别为Ｐ＜０．０１、Ｐ＜０．０１、Ｐ＜０．０５）;（２）ＩＦＮγ明显诱导甲状腺细胞表达ＨＬＡＤＲ、ＩＣＡＭ１,但对Ｂ７．１的表达无促进作用（Ｐ＜０．０１、Ｐ＜０．０１、Ｐ＞０．０５）;（３）ＰＲＬ显著诱导甲状腺细胞表达ＩＣＡＭ１、Ｂ７．１和ＴＰＯ（Ｐ＜０．０５、Ｐ＜０．０１、Ｐ＜０．０１）。结论协同刺激信号对ＡＩＴＤ的发生起着关键作用。ＩＦＮα显著诱导甲状腺细胞表达协同刺激信号（Ｂ７．１）和自身抗原ＴＰＯ,可能是临床应用ＩＦＮα诱致ＡＩＴＤ的致病原因之一。ＰＲＬ在产后甲状腺炎发病和发展中的作用应予以关注     

急性心肌梗塞后左室重构变化的研究

应用二维多普勒超声心动图对６８例急性心肌梗塞（ＡＭＩ）患者的左室重构（ＬＶＲ）变化进行了观察。结果显示，心肌梗塞后ＬＶＲ早期（３～６周）左室舒张末内径（ＬＶＤｄ）、左室舒张末容积（ＥＤＶ）、左室收缩末容积（ＥＳＶ）、左室收缩期最大室壁应力（Ｅｄｂ）、左室收缩末期室壁应力（Ｅｓｂ）、平均室壁应力（ｍｅａｎｂ）、二尖瓣舒张晚期血流速度峰值（ＰＶＡ）、左房张力（ＬＡＴ）、左房射血力（ＬＡＦ）及峰值充盈速度（ＰＦＲ）显著增大（Ｐ＜０．０１－０．００１），射血分数（ＥＦ）、心输出量（ＣＯ）、左室收缩期圆周指数（ＬＶＳＣＩ）、平均周边纤维缩短速率（ＭＶＣＦ）、二尖瓣舒张早期血流速度峰值（ＰＶＥ）及ＰＶＡ／ＰＶＥ显著降低（Ｐ＜０．０１－０．００１）。ＬＶＲ晚期（６－１２个月），ＥＤＶ、ＥＳＶ增加，ＥＦ、ＣＯ及ＬＶＳＣＩ降低（Ｐ＜０．００１）；与ＬＶＲ早期比较，ＰＶＥ、ＰＶＡ及ＬＡＦ无显著性差异（Ｐ＞０．０５）。提示ＡＭＩ后ＬＶＲ的主要病因是梗塞区膨展、左室扩张、容量负荷及室壁应力增加，从而导致心肌梗塞并发症；ＥＳＶ、ＥＤＶ及ＥＦ可作为了解远期ＡＭＩ患者预后的最佳指标。     

急性心肌梗塞后左室重构的超声心动图随访研究

目的：应用超声心动图对９２例急性心肌梗塞（ＡＭＩ）患者的左室重构（ＬＶＲ）进行随访研究,以探讨ＬＶＲ衍变规律。方法：分别于ＬＶＲ早期（３～６周）及后期（６～１２个月）应用彩色多普勒血流显像仪测定左室舒张末内径（ＬＶＤｄ）、左室收缩期圆周指数（ＬＶＳＣＩ）、左室舒张末及收缩末容积（ＥＤＶ,ＥＳＶ）、射血分数（ＥＦ）、心输出量（ＣＯ）、室壁应力指数（Ｅｄｂ,Ｅｓｂ,ｍｅａｎ服ｂ）、平均周边纤维缩短速率（ＭＶＣＦ）、二尖瓣舒张早期及晚期血流速度峰值（ＰＶＥ,ＰＶＡ）、左房张力（ＬＡＴ）、左房射血为（ＬＡＦ）及峰值充盈速度（ＰＦＲ）进行分析。结果：ＡＭＩ后ＬＶＲ早期可出现ＬＶＤｄ、ＥＤＶ、ＥＳＶ、Ｅｄｂ、Ｅｓｂ、ｍｅａｎｂ、ＰＶＡ、ＰＶＡ／ＰＶＥ、ＬＡＴ、ＬＡＦ显著增大（Ｐ＜０．０１－０．００１）,ＰＦＲ、ＥＦ、ＣＯ、ＬＶＳＣＩ、ＭＶＣＦ、ＰＶＥ显著降低（Ｐ＜０．０１—０．００１）;后期上述在室功能指标进一步减退,左房增力泵失代偿,左室畸形增加。结论：ＡＭＩ后ＬＶＲ的主要原因是梗塞区膨展、左室扩张、容量负荷及室壁应力增加,从而导致二尖瓣返流等并发症的出现。ＥＳＶ、ＥＤＶ及ＥＦ可作为了解远期预后的最佳指标。     

急性心肌梗死患者红细胞的变形能力与其三磷酸腺苷酶活性关系的研究

本文观察了５４例急性心肌梗死（ＡＭＩ）患者发病３天内红细胞变形能力（ＥＤ）和红细胞三磷酸腺苷酶（ＡＴＰａｓｅ）活性及红细胞内离子浓度的变化，并分析其相互关系。结果显示，ＡＭＩ患者红细胞滤过指数（ＩＦ）校对照组明显增高（Ｐ＜０．００１）。红细胞Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ、Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ活性和红细胞Ｋ＋、Ｍｇ２＋浓度明显降低，而红细胞Ｎａ＋、Ｃａ２＋浓度明显增高，与对照组相比差异有显著性意义（Ｐ＜０．００１）。ＡＭＩ患者红细胞ＩＦ与红细胞Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ、Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ活性、红细胞Ｋ＋、Ｍｇ２＋浓度呈负相关（Ｐ＜０．００１），与红细胞Ｎａ＋、Ｃａ２＋浓度呈正相关（Ｐ＜０．００１）。这提示ＡＭＩ患者ＥＤ降低与红细胞ＡＴＰａｓｅ活性和Ｋ＋、Ｍｇ２＋浓度降低及Ｃａ２＋、Ｎａ＋浓度增高有关。     

系统性红斑狼疮患者淋巴细胞粘附分子表达的观察

用流式细胞术及免疫双荧光染色法，分析了３５例系统性红斑狼疮（ＳＬＥ）患者外周血淋巴细胞粘附分子表型（ＣＤ＿（１１ａ）／ＬＦＡ－ｌα、ＣＤ＿（１８）／ＬＦＡ－１β、ＣＤ＿（５４）／ＩＣＡＭ－１）。结合淋巴细胞变化对ＳＬＥ作进一步探讨。结果发现ＳＬＥ活动期ＣＤ＿（１１ａ）、ＣＤ＿（１８）表达随ＣＤ＿４细胞减少而降低、ＣＤ＿８细胞增多而增高，ＣＤ＿（５４）在ＣＤ＿（２０）细胞上亦增高。此外，ＣＤ＿８细胞的ＣＤ＿（１８）增高与ＣＤ＿４ＣＤ＿（４５）ＲＡ￣＋细胞降低呈负相关（Ｐ＜０．０５），而与ＣＤ＿（２０）细胞的ＣＤ＿（５４）增高呈正相关（Ｐ＜０．０１）。提示粘附分子可能在ＳＬＥ发病机理中具有重要意义。     

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.