雷公藤多甙体外对成骨细胞功能表达的影响

目的 观察雷公藤多藤多甙（ＭＴ）体外对成骨细胞（ＧＢ）功能表达的影响,以进一步探讨雷公藤（ＴＷ）致女性骨质疏松的机制。方法 分离新生ＳＤ大鼠头盖骨ＯＢ进行原代培养,经５～６ｄ至汇合,传代后加入不同浓度ＭＴ,用对硝基苯磷酸法和考马斯亮草稿 法作碱性硝酸酶（ＡＬＰ）比比活性测定,苯素红染色法作钙化结节计数测定ＯＢ矿化能力。结果 培养６ｄ,ＭＴ１μｇ／ｍｌ起显著抑制ＯＢ ＡＬＰ比活性（Ｐ〈０．０５）,培     

雷公藤甲素对小鼠实验性结肠炎Th17／Treg的调节作用

目的探讨雷公藤甲素对三硝基苯磺酸（TNBS）诱导的结肠炎小鼠肠道Th17／Treg平衡的调节作用。方法40只BALB／c小鼠随机分为4组：对照组、模型组、雷公藤甲素低剂量组和高剂量组。模型组、雷公藤甲素低剂量组和高剂量组用TNBS诱导小鼠结肠炎模型,造模后,雷公藤甲素低剂量组和高剂量组分别腹腔注射35肛g·kg^-1·d^-1、70μg·kg^-1·d。雷公藤甲素,模型组每天腹腔注射生理盐水。对照组用50％乙醇溶液灌肠后每天腹腔注射生理盐水。2周后处死各组小鼠,评估各组小鼠结肠组织的大体和组织学评分,实时荧光定量RT-PCR检测结肠组织IL-17、RORC和Foxp3mRNA表达水平。结果雷公藤甲素低剂量和高剂量组小鼠结肠组织大体和组织学评分显著低于模型组（P〈0．05）,结肠组织IL-17、RORCmRNA表达显著低于模型组（P〈0．05）,Foxp3mRNA表达显著高于模型组（P〈0．05）,雷公藤甲素低剂量、高剂量组与对照组比较,差异无统计学意义（P〉0．05）。结论雷公藤甲素可能通过下调RORC表达抑制Th17细胞分化、IL-17产生,上调Foxp3促进Treg细胞形成,从而调节结肠炎小鼠Th17／Treg平衡,抑制肠道炎症。     

雷公藤内酯醇对人树突状细胞体外发育及免疫学功能的影响

目的：观察雷公藤内酯醇对人树突状细胞（dendritic cells,DC）体外发育及免疫学功能的影响。方法：人DC体外培养时,加入不同剂量（0、0.3、1.0、3.0、10、30、100μg/L）的雷公藤内酯醇处理,观察DC的生成情况,以流式细胞仪分析各处理组生成细胞的免疫表型及抗原内吞能力,体外混合淋巴细胞反应检测各组细胞的抗原呈递功能,TUNEL方法检测细胞凋亡。结果“体外培养7天后,10μg/L及以上剂量雷公藤内酯醇处理组细胞大部分破坏死亡。低剂量（0.3、1.0、3.0μg/L）雷公藤内酯醇处理对生成的DC的形态及数量、共刺激分子的表达、内吞蛋白质抗原OVA－FITC的能力、同种T细胞的免疫刺激活怀均无显著影响;但正常DC与同种T细胞混合培养时,雷公藤内酯醇以剂量依赖性方法抑制T细胞的增生;正常DC以30μg/L雷公藤内酯醇处理24h,有54％的细胞发生凋亡;结论：低剂量（0.3、1.0、3.0μg/L）的雷公藤酯醇处理对DC的体外发育及免疫功能均无显著影响,高剂量则阻止DC发育生成及诱导DC调亡。     

Graves眼病部分免疫抑制剂疗效探讨

目的　对比几种免疫抑制剂对Graves眼病的疗效 ,旨在寻求免疫治疗的有效手段。方法　Graves眼病 75例 ,A组 31例 ,采用泼尼松 (16例 ,其中完成 13例 )或雷公藤多甙 (TW ,15例 )治疗 ;B组 2 3例 ,采用环孢素A(CsA ,11例 )或霉酚酸酯 (MMF ,12例 )治疗 ,疗程 12周 ;对照组 2 1例 ,仅给抗甲状腺药治疗并调节甲状腺功能。疗效判断采用改进的Given Wilson积分指数系统 ,积分下降或上升≥ 3分为好转或恶化 ,<3分为无变化。结果　 12周末 ,泼尼松组 13例中 7例好转 ,6例无效 ;TW组15例中 10例好转 ,5例无变化 ;CsA组 11例中 5例好转 ,6例无效 ;MMF组 12例中 11例好转 ,1例无变化 ;对照组 2 1例中 4例好转 ,5例恶化 ,12例无效。MMF好转率高于CsA(P <0 0 5 ) ;TW与泼尼松比较差异无显著性 (P >0 0 5 )。各治疗组 12周末眼病分值均有下降 (P <0 0 1) ,下降幅度大小依次为MMF、TW、泼尼松和CsA组。结论　MMF用于治疗Graves眼病疗效优于CsA ,且较低剂量应用副作用不多 ;较小剂量的TW治疗Graves眼病疗效与泼尼松相仿 ,但可能副作用较少。     

雷公藤内酯醇对β-淀粉样蛋白诱导的大鼠小胶质细胞IL-1β和PGE2表达的影响

目的 探讨雷公藤内酯醇对β-淀粉样蛋白(Aβ)1-40诱导的大鼠小胶质细胞白细胞介素-1β(IL-1β)及前列腺素E2( PGE2)表达的影响.方法 本实验用Aβ1-40(20μg/ml)诱导体外培养的原代小胶质细胞,建立阿尔茨海默病(AD)细胞模型,并给予不同剂量雷公藤内酯醇(终浓度分别为5、25μg/ml)在不同时程(2h、12 h、24 h)进行干预,提取细胞培养上清,采用放射免疫学方法检测IL-1β和PGE2的含量.结果加药后12h,模型组IL-13和PGE2的含量比对照组明显升高(P ＜0.01);5 μg/ml组和25 μg/ml组IL-1β的含量比模型组明显减少(P＜0.01),5μg/ml组PGE2的含量比模型组明显减少(P＜0.01).结论雷公藤内酯醇对Aβ1-40诱导的小胶质细胞IL-1β和PGE2的表达上调有抑制作用.     

雷公藤内酯醇对大鼠实验性结肠炎的治疗作用

背景:炎症性肠病(IBD)病程迁延,传统的药物治疗效果均不理想,寻找新型而有效的药物一直是该领域研究的热点.目的:观察不同剂量雷公藤内酯醇对大鼠实验性结肠炎的治疗作用和不良反应.方法:60只Sprague-Dawley大鼠随机分为6组:模型组、低剂量(0.1 mg/kg)雷公藤内酯醇组、中剂量(0.2 mg/kg)雷公藤内酯醇组、高剂量(0.4 mg/kg)雷公藤内酯醇组、丙二醇(20%,5 ml/kg)对照组和地塞米松(0.2 mg/kg)对照组.应用三硝基苯磺酸(TNBS)/乙醇溶液诱导产生大鼠结肠炎模型,以相应药物处理2周后处死大鼠.处死大鼠前1天行白细胞计数检查,处死后直接称取胸腺重量.计算结肠溃疡面积和湿干比;测定结肠黏膜超氧化物歧化酶(SOD)和髓过氧化物酶(MP0)活性;采用酶联免疫吸附(ELISA)法测定结肠组织白细胞介素(IL)-1和肿瘤坏死因子(TNF)-α水平.结果:不同剂量雷公藤内酯醇治疗后,能显著减少大鼠结肠黏膜的溃疡面积,降低结肠湿干比;显著升高结肠黏膜SOD活性、降低MP0活性;显著降低IL-1和TNF-α的水平;使大鼠胸腺明显缩小,白细胞计数显著减少.结论:雷公藤内酯醇对TNBS/乙醇溶液诱导的大鼠实验性结肠炎具有显著的治疗作用,同时剂量大时亦有明显的不良反应.     

雷公藤内酯醇对系统性红斑狼疮病人B细胞表达CD86分子的影响

目的 了解系统性红斑狼疮(SLE)患者外周血B细胞表达CD86的情况，以及雷公藤内酯醇(Tripto1ide，TL)对其的影响。方法 用流式细胞仪检测外周血单个核细胞(PBMC)新鲜分离时以及与不同浓度TL在体外培养后的CB86阳性率。结果 SLE B细胞的CD86阳性率在新鲜分离时(P＜0．002)和培养48h后(P＜0．001)均较正常人B细胞高。25ng／m1的TL可明显降低SLE和正常人B细胞的CD86阳性率(P＜0．001)，2．5ng／ml则只对SLE B细胞起作用(P＜0．001)。结论 SLE病人B细胞CD86阳性率高于正常人；TL对SLE或正常人的CD86^ B细胞均有显著的下调作用，在某一浓度下仅抑制SLEB细胞的CD86表达。     

雷公藤多苷联合小剂量激素治疗特发性膜性肾病前瞻性对照研究

目的:特发性膜性肾病(IMN)是成人肾病综合征的常见原因之一,但是膜性肾病的治疗仍是临床上的一个难题.本文前瞻性地观察了单用雷公藤多苷(TW)和TW联合小剂量泼尼松(TW+P)治疗IMN的临床疗效和安全性. 方法:经肾活检并结合临床诊断为IMN患者,尿蛋白>3.5 g/24h.随机分为2组.TW组:TW 120 mg/d口服,至3个月完全缓解者,减量为维持剂量(60mg/d),持续至12个月.3个月时部分缓解或无效者,TW 120 mg/d可延长至6个月,再减量为60mg/d维持至12个月.TW+P组:TW用药同上,同时服用泼尼松30 mg/d,8周后逐渐减量(每2周隔日减5 mg),10mg/隔日维持至12个月. 结果:共84例患者入组,其中TW+P治疗组43例,TW治疗组41例.治疗3个月,TW+P组3例(6.98%)完全缓解,29例(67.4%)部分缓解,有效率为74.4%;TW组无一例完全缓解,21例(51.2%)患者部分缓解.有效率为51.2%.治疗6个月,TW+P组13例(30.2%)完全缓解,21例(48.8%)部分缓解,有效率为79.1%;TW组仍为21例(51.2%)部分缓解,无一例完全缓解,有效率为51.2%.治疗12个月,TW+P组16例(37.2%)完全缓解,17例(39.5%)部分缓解,有效率为76.7%,而TW组2例(4.88%)达到完全缓解,16例(39%)部分缓解,有效率为43.9%.TW+P组有效率和完全缓解率均明显高于TW组.不良反应的发生率两组之间无明显差异.起病年龄轻和小管间质病变较轻的IMN患者对治疗反应较好.治疗过程中两组患者血清肌酐均保持稳定. 结论:TW能有效减少膜型肾病患者蛋白尿.TW+P治疗的疗效明显优于单用TW.患者耐受性好,不良反应少,是治疗IMN的有效方法.     

雷公藤多甙对糖尿病肾病蛋白尿的影响

目的 观察雷公藤多甙对糖尿病肾病患者蛋白尿的作用及安全性.方法 选取天津医科大学代谢病医院2008年4月至12月肾病科住院及门诊的81例2型糖尿病患者为研究对象,24 h尿蛋白定量≥1.0 g,血清肌酐(Scr)<265.2 μmol/L.随机分为4组,对照组(21例)应用常规荆量血管紧张素转换酶抑制剂(ACEI)或血管紧张素受体拮抗剂(ARB),治疗组在应用常规剂量ACEI或ARB基础上,分别给予雷公藤多甙20 mg/d(低剂量组)、30 mg/d(中剂量组)、40 mg/d(高剂量组)(每组各20例),疗程3个月,观察治疗前后24 h尿蛋白定量、肝肾功能及血常规变化.结果 治疗组与对照组24 h尿蛋白定量均减少.雷公藤多甙低剂量、中剂量、高剂量治疗组24 h尿蛋白分别由治疗前(2.7±0.9)g、(2.7±0.9)g、(2.8±0.9)g减少到治疗后(2.2±1.0)g、(2.1±0.9)g、(1.9±1.0)g(P均<0.01),下降率分别为17.8%、22.8%、30.4%;对照组24 h尿蛋白由治疗前(2.4±1.2)g减少为治疗后(2.0±0.9)g(P>0.05),下降率为16.3%.雷公藤多甙治疗前后肝肾功能及外周血象比较差异均无统计学意义(P>0.05).结论 在常规治疗基础上,加用雷公藤多甙可在一定程度上降低糖尿病肾病患者蛋白尿水平,且随雷公藤多甙用药剂量在一定范围内增加,24 h尿蛋白定量下降率增大,趋势检验有统计学意义(P<0.05),对患者的肝、肾功能及外周血象未见明显不良影响.     

杜仲叶提取物对人牙周膜干细胞体外增殖及成骨分化的影响

目的研究杜仲叶提取物对人牙周膜干细胞(hPDLSCs)体外增殖与成骨分化的影响。方法原代培养hPDLSCs,分别将含10~(-4),10~(-5),10~(-6) g/ml杜仲叶提取物的传统矿化诱导培养基与hPDLSCs作用作为实验组,以DMEM完全培养基为空白对照组,以传统矿化诱导培养基为阳性对照组。四甲基偶氮唑盐(MTT)法检测各组细胞的增殖活性、检测碱性磷酸酶(ALP)活性、RT-PCR法检测各组细胞成骨相关基因(Runx2,OPN,OCN)的表达。结果 MTT结果显示,5组细胞分别培养1 d后,OD值均较小,组间无显著差异(P0.05)。各组细胞OD值在3～7 d持续增加,实验组显著高于空白对照组和阳性对照组(P0.05)。浓度为10~(-4),10~(-5),10~(-6) g/ml的杜仲叶提取物均可促进hPDLSCs的增殖,且各实验组OD值随着杜仲叶提取物质量浓度的增加而增加,存在剂量依赖效应。3个实验组和阳性对照组ALP活性均明显增高,且各实验组与阳性对照组差异显著(P0.05)。空白对照组的ALP活性变化不显著。ALP活性变化具有时间依赖性,实验组和阳性对照组从第5天开始显著升高,第7天达到最高值。RT-PCR结果显示,各实验组和阳性对照组的Runx2,OPN,OCN表达均上调,且3个基因的表达量在各实验组均明显高于阳性对照组、空白对照组(P0.05,P0.01)。结论质量浓度为10~(-4),10~(-5),10~(-6) g/ml的杜仲叶提取物可促进hPDLSCs增殖和成骨分化,其中10~(-4) g/ml浓度作用最显著。     

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.