福建省临床分离非结核分枝杆菌菌种分布研究

目的 分析我院临床分离非结核分枝杆菌(NTM)菌株,探讨福建省NTM临床分离率和菌种分布情况。方法 对我院2009-2012年临床分离6 362株分枝杆菌进行结核分枝杆菌复合群(MTBC)与NTM鉴别,对鉴定为NTM菌株应用hsp65-和rpoB- PCR-RFLP进行菌种鉴定。结果 6 362株临床分离分枝杆菌共鉴别出649株NTM。鉴别出的649株NTM菌株,经hsp65-和rpoB-PCR-RFLP鉴定,菌种分布达24个种,其中菌株数量前3位菌种为:胞内分枝杆菌(M.intracellulare)302株(46.5%),鸟分枝杆菌(M. avium)138株(21.3%),脓肿分枝杆菌(M. abscessus)81株(12.5%)。结论 2009-2012 年福建省NTM临床分离率占分枝杆菌培养阳性菌株的10.2%,NTM种类多,以鸟-胞内分枝杆菌复合群(MAC)为福建省NTM的主要流行菌种,占总数的67.8%。     

应用多重PCR方法快速鉴定结核分枝杆菌复合群与非结核分枝杆菌的研究

目的 建立并评估快速鉴定结核分枝杆菌复合群（MTBC）与非结核分枝杆菌（NTM）的多重PCR方法。 方法 应用分别针对MTBC的oxyR-ahpC基因间隔区、MTBC和NTM的rpoB基因可变区的3对分枝杆菌特异性引物进行多重PCR扩增,扩增产物分别为473 bp、235 bp和136 bp。应用该多重PCR方法对6株MTBC标准株、50株NTM标准株、312株MTBC临床分离株和300株NTM临床分离株进行了初步菌种鉴定。 结果 经多重PCR 扩增后进行凝胶电泳,MTBC标准株473 bp和235 bp片段均可见,NTM标准株仅见136 bp片段。312株MTBC临床分离株中,310株扩增出473 bp和235 bp片段,敏感度为99.36%（310/312）,特异度为99.32%（294/296）;300株NTM临床分离株中,294株扩增出136 bp片段,敏感度为98.00%（294/300）,特异度为100.00%（310/310）。 结论 该多重PCR方法可检测并鉴别MTBC及NTM,具有高度的特异度和敏感度,有可能作为鉴别MTBC与NTM的有价值的检测手段。     

2017年绍兴地区106株非结核分枝杆菌菌种鉴定结果分析

目的 分析绍兴地区非结核分枝杆菌(NTM)的流行情况,为NTM诊疗提供科学依据。方法 对绍兴地区2017年临床分离的972株分枝杆菌,采用结核分枝杆菌抗原检测胶体金法进行结核分枝杆菌复合群和NTM的初步菌种鉴定,结果106株为NTM,占分枝杆菌培养阳性菌株的10.91%(106/972),对初步鉴定为NTM的菌株应用 DNA微阵列芯片法进行NTM菌种鉴定。结果 106株NTM菌株经DNA微阵列芯片法鉴定,共有14个菌种,其中菌株数量前3位的菌种为:胞内分枝杆菌[55株(51.89%)]、鸟分枝杆菌[19株(17.92%)]、堪萨斯分枝杆菌[13株(12.26%)]。其余分别为:龟-脓肿分枝杆菌[4株(3.77%)]、瘰疬分枝杆菌[3株(2.83%)]、戈登分枝杆菌[3株(2.83%)]、土分枝杆菌[2株(1.89%)]、其他[7株(6.60%)]。结论 2017 年绍兴地区NTM 临床分离率占分枝杆菌培养阳性菌株的10.91%;NTM种类多,以胞内分枝杆菌、鸟分枝杆菌、堪萨斯分枝杆菌为主要流行菌种。     

大理地区13株疑似非结核分枝杆菌临床分离株的鉴定

目的对云南大理地区13株疑似非结核分枝杆菌(Non-Tuberculous mycobacteria,NTM)进行鉴定,了解其菌种构成。方法大理州疾控中心提供的疑似非结核分枝杆菌13株,经罗氏培养基(L-J)、噻吩-2-羧酸肼(TCH)和对硝基苯甲酸(PNB)鉴别培养基初步鉴别培养确定为NTM后分别通过16S rRNA、hsp65和rpoB基因片段测序进行菌种鉴定。结果 13株疑似NTM临床分离株经16S rRNA、rpoB和hsp65基因DNA测序分析鉴定为NTM 11株(84.62%),束村氏菌1株(7.69%),戈登氏菌1株(7.69%)。11株NTM中鸟分枝杆菌(M.avium)9株,脓肿分支杆菌(M.abcessus)2株。结论经抗酸染色筛查、L-J和PNB/TCH培养基初步鉴定为NTM的临床分离株通过3种不同基因测序分析鉴定为NTM、束村氏菌和戈登氏菌,以NTM中的鸟分枝杆菌占多数。     

非结核分枝杆菌与结核分枝杆菌皆培养阳性病例的分析

非结核分枝杆菌(nontuberculous mycobacteria.NTM)与MTB同属与分枝杆菌属,其主要侵犯脏器也是肺部,因此在临床上NTM肺病易被误诊为肺结核,而肺结核也可同时合并NTM感染[1].据文献报道,我国从MTB分离株中鉴定出NTM菌株的构成比从1979年的4.3％( 29/682)升至2000年的11.1％ (49/441)[2].为加强NTM肺病与肺结核的鉴别诊断,我们对91例经NTM和MTB培养均为阳性病例的临床特点进行了研究.     

43株甘肃临床分离非结核分枝杆菌分类鉴定

目的了解甘肃当前临床流行的非结核分枝杆菌(NTM)的病原谱特点及其主要NTM种类,为指导临床诊疗、有效防治NTM肺病提供参考依据。方法收集2012年~2014年来源于甘肃省不同地区的875株临床分离分枝杆菌菌株,经PNB/TCH方法初步鉴定为疑似NTM菌株,采用16SrRNA基因测序技术进行菌种鉴定。结果 875株分枝杆菌临床分离菌株中分离出疑似NTM菌株46株。经16SrRNA基因序列分析鉴定,43株为NTM,3株为诺卡氏菌。43株NTM菌株分别为胞内分枝杆菌、堪萨斯分枝杆菌、塞内加尔分枝杆菌、鸟分枝杆菌、戈登氏分枝杆菌、楚尔盖分枝杆菌、罕见分枝杆菌、偶然分枝杆菌和脓肿分枝杆菌。其中,胞内分枝杆菌有31株,占总NTM菌株数的72.09%。结论甘肃省非结核分枝杆菌群以胞内分枝杆菌为主,应用16SrRNA基因序列分析鉴定方法能准确鉴定出NTM菌种,为临床诊治提供依据。     

南京地区2017—2020年结核 及非结核分枝杆菌菌株分布及耐药情况分析

[摘要]?目的?了解南京地区2017—2020年分枝杆菌临床分离菌株的分布及对常用抗结核药物的耐药性，为本地区结核病临床治疗提供实验室依据。方法?回顾性分析2017—2020年南京市第二医院检验检测中心分离培养的5018株分枝杆菌，经菌种鉴定和绝对浓度法药物敏感性试验，分析结核分枝杆菌（Mycobacterium tuberculosis, MTB）和非结核分枝杆菌（nontuberculosis mycobacteria, NTM）对9种抗结核药物的耐药性。结果 5018株分枝杆菌经初步菌种鉴定，3898株（77.7%）为MTB，1120株（22.3%）为NTM。其中619株NTM经进一步菌种鉴定判定主要为胞内分枝杆菌（Mycobacterium intracellulare, MIN），龟分枝杆菌脓肿亚种（Mycobacterium abscessus, MAB）和鸟分枝杆菌（Mycobacterium avium, MAV），分别有376株（60.7％），80株（12.9%）和66株（10.7%）。MTB对9种抗结核药物的耐药率，异烟肼最高（20.4%），卷曲霉素最低（2.2%），异烟肼、左氧氟沙星、卷曲霉素、对氨基水杨酸耐药率在2017—2020年均呈上升趋势（P均＜0.05）；4年间所有单耐药结核菌株（mono-resistant tuberculosis, MR-TB）、多耐药结核菌株（poly-drug resistant tuberculosis, PDR-TB）、耐多药结核菌株（multi-drug resistant tuberculosis, MDR-TB）、广泛耐药结核菌株（extensively-drug resistant tuberculosis, XDR-TB）占比分别为9.2％、6.5％、12.7％、2.2％，其中MR-TB、PDR-TB占比在2017—2020年间呈显著下降趋势（P均＜0.05），MDR-TB、XDR-TB占比在2017—2020年间呈显著上升趋势（P均＜0.05）。1120株NTM对纳入研究的9种抗结核药物均有不同程度的耐药。 结论?南京地区分枝杆菌感染以MTB为主，其中MDR-TB、XDR-TB占比呈显著上升趋势；NTM菌种主要是MIN，MAB和MAV，对抗结核药物普遍耐药。临床应加强对分枝杆菌的分离鉴定并密切监测相关菌株的耐药性，为有效控制分枝杆菌感染和进行针对性治疗提供理论依据。     

129株非结核分枝杆菌采用两种分子检测技术行菌种鉴定的结果分析

目的 分析北京地区3个单位非结核分枝杆菌 (NTM)临床分离株采用芯片杂交法(简称“芯片法”)和16S rRNA基因测序(简称“基因测序”)进行菌种鉴定的结果,为临床分枝杆菌病的快速准确诊断提供科学依据。方法 用芯片法和基因测序进行北京地区3个单位129株NTM临床分离株的菌种鉴定,实验操作者之间采用双盲法,对两种鉴定方法的结果进行比较和评价。结果 129株NTM菌株中,有107株进行分枝杆菌基因测序,其中59株为胞内分枝杆菌(55.1%);29株为堪萨斯分枝杆菌(27.1%);5株为龟分枝杆菌/脓肿分枝杆菌(4.7%);3株为鸟分枝杆菌(2.8%);2株为偶发分枝杆菌(1.9%);2株为戈登分枝杆菌(1.9%);1株为蟾蜍分枝杆菌(0.9%);1株为草分枝杆菌(0.9%);1株为瘰疬分枝杆菌(0.9%);4株为其他NTM(3.7%)。有116株进行芯片法分枝杆菌菌种鉴定,且有96株同时进行芯片法和基因测序法检测,两种方法进行菌种鉴定的符合率为88.5%(85/96)。基因测序发现有3株外来菌株,分别为明尼苏达分枝杆菌、熊本分枝杆菌、提门分枝杆菌(M.temen)。结论 北京3家机构NTM菌种以胞内分枝杆菌、堪萨斯分枝杆菌和龟分枝杆菌/脓肿分枝杆菌为主。用芯片法和基因测序对NTM临床分离株进行菌种鉴定的一致率较高。     

广州市非结核分枝杆菌临床分离株菌种鉴定及药物敏感性试验结果分析

目的 对广州市非结核分枝杆菌(NTM)临床分离株进行菌种鉴定与药物敏感性试验(简称“药敏试验”),为临床诊断和治疗NTM病提供依据。方法从2016年广州市胸科医院行分枝杆菌分离培养的1250份标本中搜集培养阳性的717株临床分离株,采用水溶性对硝基苯甲酸(PNB)和噻吩-2-羧酸肼(TCH)对其进行培养,以鉴别MTB与NTM,通过多靶位基因聚合酶链反应 (PCR)测序,对PNB和TCH培养确定为NTM的菌株进一步行菌种鉴定,并采用最低抑菌浓度法(MIC)检测98株NTM对18种抗结核药物的耐药性。结果717株分枝杆菌中,检出106株NTM菌株,检出率为14.4%;其中103株传代成功,传代率为97.2%(103/106)。经NTM菌种鉴定,按照构成比高低依次为脓肿分枝杆菌[34.0%(35/103)]、胞内分枝杆菌[25.2%(26/103)]、马赛分枝杆菌[20.4%(21/103)]、鸟分枝杆菌[9.7%(10/103)]、堪萨斯分枝杆菌[5.8%(6/103)]、偶发分枝杆菌[1.9%(2/103)],以及1株缓黄分枝杆菌、1株猪分枝杆菌和1株阿加普尔分枝杆菌[均占0.9%(1/103)]。98株NTM菌株的药敏试验结果显示,敏感者前3位依次为阿米卡星[93.9%(92/98)]、克拉霉素[91.8%(90/98)]和阿奇霉素[71.4%(70/98)],耐药者前3位依次为利福平[89.8%(88/98)]、左氧氟沙星[83.7%(82/98)]和亚胺培南[77.6%(76/98)]。并且NTM不同菌种对部分药物的耐药性存在种间差异。结论广州市NTM的检出率高于我国其他地区,流行的菌种以脓肿分枝杆菌和胞内分枝杆菌为主;克拉霉素和阿米卡星是临床治疗NTM患者的优选抗生素,应重视对利福平和左氧氟沙星的耐药性。     

四川省46株疑似非结核分枝杆菌临床分离株菌种鉴定结果分析

目的对四川省46株疑似非结核分枝杆菌进行菌种鉴定。方法针对四川省46份临床分离疑似非结核分枝杆菌(Nontuberculous mycobacteria,NTM) 16S rRNA基因和16S-23S rRNA内转录间隔区(ITs)进行基因测序和序列分析。结果 46株菌株中,35株鉴定为NTM (经基因测序,分别为11种菌),10株为戈登氏菌,1株为诺卡氏菌。结论四川省NTM至少有11种,以胞内分枝杆菌、脓肿分枝杆菌和堪萨斯分枝杆菌为主。NTM菌种鉴定对临床鉴别诊断和合理治疗有一定的意义。     

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.     

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.     

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.     

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。     

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.     

Angiographic diagnosis of the degree of serosal invasion of carcinoma of the colon

Angiography using Prostaglandin El^® was performed on 38 patients with carcinoma of the colon in order to diagnose the degree of serosal cancer invasion. The findings at angiography were classified into four groups:1) AG-S3, abnormal change (irregularity and/or encasement) up to marginal vessels; 2) AG-S2, abnormality up to vasa recta; 3) AG-S1, abnormality of penetrating branches of vasa recta within the wall of the colon; and 4) AG-S0, no distinct findings of abovementioned vessels. These angiographic findings were compared with both macroscopic and microscopic serosal cancer invasion. Angiographic diagnosis is in accord with the macroscopic findings in 84.2 percent of cases. Angiographic diagnosis is in accord with the microscopic findings in 32.4 percent of cases. Macroscopic findings confirm the angiographic diagnosis precisely but the conflict with microscopic findings should not be overlooked. This may be the result of inflammatory change, adhesion, and fibrosis around carcinoma of the colon.     

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.