肝脾调补方对大鼠急性酒精性肝损伤的防护作用研究

目的：观察中药肝脾调补方对大鼠急性酒精性肝损伤的防护作用.方法：采用白酒灌胃法建立大鼠急性酒精性肝损伤模型.通过肝脾调补方高、中、低剂量灌胃,观察肝脾调补方对各组大鼠血清ALT、AST、肿瘤坏死因子（TNF-α）、白细胞介素-6（IL-6）及肝组织匀浆超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、一氧化氮（NO）水平的影响.结果：肝脾调补方可明显降低大鼠血清ALT、AST、TNF-α、IL-6水平;降低肝组织匀浆的NO的含量,提高肝匀浆SOD、GSH-Px活性.结论：肝脾调补方对急性酒精性大鼠肝损伤有防护作用,能改善肝功能,其机制可能与减轻肝脏炎症、抗脂质过氧化有关.     

非酒精性脂肪性肝炎发病机制的实验研究

建立大鼠非酒精性脂肪性肝炎 (NASH)动物模型 ,探讨NASH发病机制。雄性SD大鼠随机分为对照组及模型组 ,检测血清转氨酶、空腹血糖 (FBG)、胰岛素 (FBI)及肿瘤坏死因子α(TNFα)水平 ,肝组织匀浆MDA、SOD水平 ,肝组织学改变。于 9周末模型组大鼠已产生胰岛素抵抗 ,血清TNFα水平明显升高 ,肝细胞出现脂肪变及气球样变 ;14周末血清转氨酶水平及肝组织匀浆MDA水平明显升高 ,SOD水平明显下降 ,肝组织出现炎细胞浸润。胰岛素抵抗与TNFα在肝脏脂肪变的发生中起到重要作用 ,而炎症产生与脂质过氧化的关系更为密切     

柴胡皂苷对酒精性肝病大鼠的治疗作用

目的观察柴胡皂苷酒精性肝病大鼠的治疗作用。方法将60只Wistar雄性大鼠随机分为正常对照组、模型组和柴胡皂苷组,采用白酒灌胃的方法建立酒精性肝病大鼠模型,给予柴胡皂苷治疗。12 w后检测血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)及肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)水平;HE染色观察肝脏的病理变化。结果与模型组比较,柴胡皂苷组血清中ALT、AST含量均低于模型组(P<0.05);柴胡皂苷组肝组织中MDA含量低于模型组(P<0.05),SOD活性高于模型组(P<0.05)。肝组织病理结果提示柴胡皂苷对酒精性肝病大鼠具有保护作用。结论柴胡皂苷能抑制酒精诱导脂质过氧化反应对肝组织的损伤,对酒精性肝损伤有明显保护作用。     

降脂护肝胶囊治疗非酒精性脂肪性肝病的实验研究

目的:探讨降脂护肝胶囊对非酒精性脂肪性肝病(NAFLD)的疗效.方法:采用高胆固醇高脂饮食喂养,复制NAFLD大鼠模型,设降脂护肝胶囊治疗组(Z组)、模型组(M组)及空白对照组(K组),检测各组大鼠血清ALT、AST、TG、TC、TNF-α、IFN-γ水平及肝组织SOD活性、MDA浓度,观察肝脏组织病理学变化.结果:M组大鼠ALT、AST、TG、TC、MDA、TNF-α、IFN-γ水平明显升高,而SOD表达下降,与K组比较,差异有显著性意义(P<0.01或P<0.05);Z组大鼠的8次指标检测结果均得到明显改善,与M组比较,差异有显著性意义(P<0.01或P<0.05).M组大鼠肝脏脂肪变明显,且有散在坏死灶及炎性细胞浸润;Z组大鼠肝脏脂肪变比M组明显减轻,肝窦基本正常,无炎性细胞浸润.结论:降脂护肝胶囊能显著改善非酒精性脂肪肝大鼠的肝功能,降低血脂,提高肝细胞SOD活性,降低MDA含量,抑制炎症反应中细胞因子TNF-α、IFN-γ,改善肝组织学病理情况,对非酒精性脂肪性肝病有较好的治疗效果.     

白芍总苷对大鼠酒精性脂肪肝的保护作用及其机制

目的探讨白芍总苷（TGP）对大鼠酒精性脂肪肝的保护作用及机制。方法 60只大鼠随机分为正常对照组（15只）、模型组（15只）、TGP低剂量组（15只）和高剂量组（15只）。采用高脂饮食联合乙醇灌胃6周建立大鼠酒精性脂肪肝模型。TGP低、高剂量组分别于每天早晨灌胃后2 h左右给予TGP 20、60 mg/kg灌胃6周。采用生化法检测血清谷丙转氨酶（ALT）、谷草转氨酶（AST）、总胆红素（TB）水平和肝匀浆超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）活性,丙二醛（MDA）含量;HE染色观察肝脏病理形态学变化;免疫组化法检测肝脏NF-κB和TNF-α的表达。结果 TGP高剂量组血清ALT、AST及TB明显低于模型组（P〈0.05或〈0.01）;TGP高、低剂量组肝匀浆MDA水平较模型组明显下降（P均〈0.01）,SOD及GPx活性较模型组明显升高（P〈0.05或〈0.01）;光镜下显示TGP高、低剂量组肝脏脂肪变性明显减轻（P均〈0.01）;免疫组化显示,TGP高、低剂量组肝组织NF-κB和TNF-α表达较模型组明显降低（P〈0.05或〈0.01）。结论 TGP对大鼠酒精性脂肪肝具有一定的保护作用,其作用可能与抑制NF-κB的表达、抑制氧化应激、减少炎症因子的释放有关。     

谷氨酰胺对非酒精性脂肪肝炎大鼠肠黏膜屏障的保护作用

目的 探讨谷氨酰胺对非酒精性脂肪肝炎肠黏膜屏障功能的保护作用.方法 32只SD大鼠随机分为正常对照组8只,给予普通饮食喂养;高脂饮食组24只,给予高脂饲料喂养,于8周末从高脂饮食组随机抽取8只大鼠处死作为单纯性脂肪肝组,剩余大鼠随机分为谷氨酰胺组、NASH组,谷氨酰胺治疗组在8周末加用谷氨酰胺灌胃.12周末处死所有大鼠,测定大鼠门静脉血浆中内毒素、腹主动脉血浆中D-木糖以及肠粘液中sXgA的水平,测定小肠组织匀浆中SOD的活性和MDA的含量,并测定大鼠血清中TC、TC、ALT、AST,HE染色观察肝脏病理改变.结果 12周模型组大鼠血清ALT、AST明显升高,肝脏病理表现为脂肪性肝炎,谷氨酰胺治疗组大鼠血清ALT、AST明显下降(P＜0.05),肝组织炎症活动计分也明显下降(3.25±1.49 vs.4.38±1.06,P＜0.05),但仍显著高于8周单纯性脂肪肝组大鼠水平(3.25±1.49 vs.2.00±0.76,P＜0.05).谷氨酰胺治疗组肝细胞脂肪变性程度无显著变化.谷氨酰胺治疗组大鼠门静脉血浆中内毒素、腹主动脉血浆中D-木糖、小肠组织匀浆中MDA含量与模型组相比明显降低(P＜0.05).肠黏液中slgA的水平和小肠组织匀浆中SOD与模型组相比明显升高(P＜0.05).结论 谷氨酰胺可以降低高脂饮食诱发的非酒精性脂肪性肝炎大鼠血清中转氨酶水平和肝组织炎症损伤,降低门静脉血中内毒素水平,但不能完全阻止炎症的进展,提示肠黏膜屏障功能的改变是非酒精性脂肪性肝炎发病的重要机制之一.     

夏枯草硫酸多糖对异烟肼所致小鼠抗结核药物性肝损伤的保护作用及机制

[目的]分析夏枯草硫酸多糖对异烟肼所致小鼠抗结核药物性肝损伤的保护作用,并探究其可能的机制。[方法]将24只SPF级雄性C57 BL/6小鼠随机分为正常对照组、模型组和实验组,每组8只。模型组和实验组每日定时予以异烟肼100 mg/kg灌胃1次。实验组于异烟肼灌胃前予以夏枯草硫酸多糖100 mg/kg灌胃预处理,每4 d灌胃1次,共3次。异烟肼处理2周后处死小鼠,检测血清丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)活性;肝脏匀浆后检测肝组织丙二醛(MDA)、超氧化物歧化酶(SOD)活性;苏木精-伊红染色观察肝脏组织病理形态学的改变;RT-qPCR技术检测肝脏组织白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)mRNA的表达;Western blot技术检测肝脏组织IL-6和TNF-α蛋白的表达。[结果]与正常对照组相比,模型组和实验组小鼠血清AST、ALT活性水平和肝组织MDA含量升高(P0.001),肝组织SOD活性降低(P0.001),IL-6和TNF-αmRNA和蛋白表达明显升高(P0.001),肝组织病理可见不同程度的肝细胞变性坏死及炎细胞浸润。实验组与模型组相比,小鼠血清AST、ALT活性水平和肝组织MDA含量降低,肝组织SOD活性升高(P0.001),IL-6和TNF-αmRNA和蛋白表达明显降低(P0.001),肝组织病理改变明显减轻。[结论]夏枯草硫酸多糖对异烟肼所致小鼠抗结核药物性肝损伤具有保护作用,其作用机制可能与抗氧化应激反应、降低炎症反应有关。     

柴胡皂苷对抑郁症大鼠海马BDNF表达的影响

目的目的观察柴胡皂苷酒精性肝病大鼠的治疗作用研究。方法将60只wistar雄性大鼠随机分为正常对照组、模型组和柴胡皂苷组,采用白酒灌胃的方法建立酒精性肝病大鼠模型,给予柴胡皂苷治疗。12 w后检测血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)及肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)水平;HE染色观察肝脏的病理变化。结果与模型组比较,柴胡皂苷组血清中ALT、AST的含量均低于模型组,差别有统计学意义(P<0.05);柴胡皂苷组肝组织中MDA含量的低于模型组,差别有统计学意义(P<0.05);柴胡皂苷组肝组织中SOD活性高于模型组,差别有统计学意义(P<0.05)。肝组织病理结果提示柴胡皂苷对酒精性肝病大鼠具有保护作用。结论柴胡皂苷能抑制酒精诱导脂质过氧化反应对肝组织的损伤,对酒精性肝损伤有明显保护作用。     

非酒精性脂肪性肝炎大鼠血液流变学的改变

[目的]探讨非酒精性脂肪性肝炎(NASH)大鼠血液流变学的改变。[方法]健康雄性Wistar大鼠16只,随机分为正常组和模型组,分别以标准饲料和高脂饲料喂养,连续12周后处死大鼠,苏木精-伊红染色观察大鼠肝脏组织病理学变化,脂酶法检测肝组织匀浆三酰甘油(TG)、胆固醇(TC)水平,黄嘌呤氧化酶法检测血及肝组织匀浆中超氧化物歧化酶(SOD)水平,硫代巴比妥酸(TBA)法检测血及肝组织丙二醛(MDA)水平,锥板法检测血液流变学指标。[结果]模型组大鼠肝组织重度脂肪变,并伴有肝细胞气球样变,肝细胞碎屑样坏死、炎症细胞浸润和汇管区渗出;肝组织匀浆TG、TC水平较正常组明显升高(P<0.01);血清及肝组织匀浆中MDA水平均较正常组明显增高(P<0.05)、SOD活力均较正常组明显下降(P<0.05);全血黏度(高、中、低切)、全血还原黏度及红细胞聚集性指数明显高于正常组(P<0.01,<0.05),血浆黏度、红细胞刚性和红细胞变形指数2组之间差异无统计学意义(P>0.05)。[结论]高脂饲料诱导的NASH大鼠存在血液流变学指标的异常改变。     

蒙药德都红花-7味散对高脂饮食诱导实验性脂肪肝大鼠血脂四项和SOD、MDA的影响

目的:观察蒙药德都红花-7味散对非酒精性脂肪肝的治疗作用及其机制,为临床用药提供理论依据.方法:取Wister♂大鼠,随机分为空白组8只、空白给药(德都红花-7味散)、模型组、德都红花-7味散低、高剂量组,各组10只.除空白组和空白给药组,按2 m L/100 g脂肪乳剂灌胃,1次/d,共计给脂肪乳剂灌胃4 wk.空白给药组、德都红花-7味散低、高剂量组分别给予蒙药德都红花-7味散0.6、0.6、3.0 g/(kg·d).各给药组均提前7 d给药,给药体积为1 m L/100 g,1次/d,灌胃给药;其他两组灌胃等体积蒸馏水,共计给药5 wk.观察各组大鼠血脂四项,肝功,肝组织匀浆中总胆固醇(cholesterol,CHO)、甘油三酯(triglyceride,TG)、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)含量;HE染色观察肝脏细胞脂肪变程度.结果:与空白组比较,模型组大鼠血清TG、CHO、低密度脂蛋白(low density lipoprotein cholesterol,LDL-C)、肝匀浆TG、CHO、MDA、空白给药组MDA升高,血清高密度脂蛋白(high density lipoprotein cholesterol,HDL-C)、肝匀浆SOD明显降低;德都红花-7味散低、高剂量组大鼠血清CHO、LDL-C升高,有显著性差异(P0.05).与模型组比较,低剂量组血清TG降低,高剂量组血清CHO、LDL-C降低、HDL-C升高,空白给药组肝匀浆TG、CHO、MDA降低,SOD升高;低剂量组肝匀浆TG、CHO、MDA降低,高剂量组肝匀浆TG、MDA降低,SOD升高有显著性差异(P0.05).给药组肝组织脂肪变程度较模型组明显减轻.结论:蒙药德都红花-7味散治疗高质饮食脂肪肝疗效确切,抗脂质过氧化可能是其治疗机制的一部分.     

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.