室间隔缺损介入治疗后心脏形态的变化及培哚普利对其干预作用

目的:观察介入治疗室间隔缺损(VSD)后心脏形态的变化规律,评价培哚普利对VSD患者封堵后左室形态、功能和肺动脉收缩压的干预影响。方法:入选经胸超声心动图(TTE)测得VSD<15.0 mm或伴有膜部瘤时基底部直径<20 mm的20例VSD患者,分成治疗组和对照组。2组均于介入治疗前1 d开始予肠溶阿司匹林200 mg/d×1个月,然后100 mg/d×5个月,治疗组加服培哚普利2 mg/d×6个月。术前,术后24 h、3个月、6个月行TTE和心电图检查,心室容积和左室射血分数采用面积长度法测定,连续多普勒根据三尖瓣反流估测肺动脉收缩压。结果:与术前相比,术后24 h左室高动力循环状态改善,左室射血分数降低(P<0.05),以后维持正常水平而保持正常左室功能。术后肺动脉收缩压虽降低,但与术前比差异均无统计学意义(P>0.05)。左房室内径、容积术后较术前差异无统计学意义(P>0.05)。治疗组经培哚普利口服6个月后,左房内径、左室内径和容积、肺动脉收缩压、左室射血分数和左室短轴缩短率与对照组相比均差异无统计学意义(P>0.05)。结论:由于膜部VSD一般均较小,术后24 h左室高动力循环状态减轻,培哚普利对左心和肺动脉压力及右心功能无影响。     

超声心动图与左心室造影评价室间隔缺损封堵术后左心室功能变化的相关性研究

目的通过左心室造影和超声心动图同步评价室间隔缺损(VSD)封堵术前后左心室功能变化,对两种方法测量的相关性进行探讨。方法对我院28例成功采用新型Amplatzer封堵器治疗的VSD患者进行研究。所有患者术前24h、术后24h行经胸超声心动图(TTE)检查,封堵前及封堵后行左心室造影检查,同时进行左心室容积和径线的测量,将超声和造影的测量结果进行直线相关及回归分析。结果两种方法均提示VSD封堵术后左心室舒张末容积(LVEDV)、左心室收缩末容积(LVESV)、左心室每博量(LVSV)减小,左心室射血分数(LVEF)无明显改变。两种方法在LVEDV、LVESV、LVSV和LVEF等左心室容积指标测量方面,相关系数分别为0.81、0.63、0.69和0.82;在左心室长径L和左心室短径D等径线指标测量方面,相关系数分别为0.84和0.86。结论超声心动图和左心室造影在评价VSD封堵术前后左心室功能变化方面有着良好相关性,超声心动图检查可作为长期的随访手段。     

培哚普利与氯沙坦治疗心力衰竭对心室重构的影响

目的　观察培哚普利与氯沙坦联合治疗老年性慢性心力衰竭 (CHF)对心室重构与血脑利钠肽 (BNP)水平的影响。方法　心衰患者随机分为培哚普利组与培哚普利加氯沙坦组。在治疗前及治疗后 3个月测定心功能与左室内径等指标 ,并测定血浆BNP含量的变化。结果　BNP与NYHA分级、LVEDD、LVESD呈正相关 ;与LVEF增加呈负相关。培哚普利加氯沙坦组LVEDD、LVESD下降显著 ,LVEF增加明显 ,与培哚普利组比较有显著差异性 (P <0 .0 5)。结论　培哚普利加氯沙坦治疗老年CHF较单独应用培哚普利治疗能更好地改善心衰 ,预防左室重构、降低血浆BNP水平。     

国产封堵器介入治疗房间隔缺损后心功能变化的研究

目的探讨国产封堵器介入治疗房间隔缺损(ASD)后心脏形态和功能的变化规律。方法全组60例,年龄5～35(16.10±10.71)岁,体重17～7(243.91±13.21)kg,经胸超声心动图(TTE)示ASD最大径7～3(618.3±7.2)mm,选用封堵器型号为10～4(026±3)mm。术后3d、3个月、6个月和12个月行TTE追踪测量。采用心尖四腔切面面积-长度法计算左右心室容积及射血分数。结果术后3d,右心房上下径、左右径,右心室舒张末期前后径、左右径均逐渐减小(与术前比较,P<0.05);右室舒张末期容积(RVEDV),右室收缩末期容积(RVESV),及右室射血分数(RVEF)均逐渐减小(与术前比较,P<0.05)。3～6个月随访,右心功能进一步改善。至12个月随访时,右心房、右心室大小及右心功能恢复正常(与术前比较,P<0.01)。术后3d,左室舒张末期前后径(LVEDD),左室舒张末期容积(LVEDV)均逐渐增大(与术前比较,P<0.05);左室收缩末期容积(LVESV),左室每搏量(LVSV)及左室射血分数(LVEF)均逐渐增大(与术前比较,P<0.05)。3～6个月随访,左心功能进一步改善。至12个月随访时,左心房、左心室大小及左心室功能恢复正常(与术前比较,P<0.01)。结论国产封堵器介入封堵ASD,既阻断了异常分流,又改善了左心室及右心系统功能及其几何构型。     

美托洛尔缓释片对血流储备分数>0.80冠心病患者心功能的影响

目的探讨美托洛尔缓释片对血流储备分数(FFR)0.80冠心病患者心功能的影响。方法选取孙逸仙心血管医院2012—2015年收治的FFR0.80的冠心病患者81例,随机分为对照组39例和观察组42例。在常规治疗基础上,对照组患者给予安慰剂,观察组患者给予美托洛尔缓释片;两组患者均连续治疗3个月。比较两组患者治疗后心率、血压(收缩压、舒张压)、心功能分级,治疗前及治疗后1、2、3个月心功能指标〔左心房内径(LAD)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左房室瓣-室间隔间距(EPSS)、左心室短轴缩短率(LVFS)、左心室质量(LVM)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)和左心室射血分数(LVEF)〕,随访3个月期间再入院情况。结果观察组患者治疗后心率、收缩压、舒张压低于对照组,心功能分级优于对照组(P0.05)。时间与方法在LVEDD、LVESD、LVFS、LVEDV、LVESV、LVEF上存在交互作用(P0.05),在LAD、EPSS、LVM上无交互作用(P0.05);时间在LAD、LVEDD、LVESD、EPSS、LVFS、LVM、LVEDV、LVESV、LVEF上主效应显著(P0.05);方法在LAD、LVEDD、LVESD、EPSS、LVFS、LVM、LVEDV、LVESV、LVEF上主效应显著(P0.05);治疗后1个月观察组患者LVESD低于对照组(P0.05);治疗后2个月观察组患者LAD、LVEDD、LVESD、LVEDV低于对照组,LVFS、LVEF高于对照组(P0.05);治疗后3个月观察组患者LAD、LVEDD、LVESD、EPSS、LVM、LVEDV、LVESV低于对照组,LVFS、LVEF高于对照组(P0.05)。观察组患者随访期间再入院率低于对照组(P0.05)。结论美托洛尔缓释片可有效降低FFR0.80冠心病患者心肌耗氧量,抑制患者心室重构并改善患者心功能。     

伴重度肺动脉高压的动脉导管未闭封堵器疗效观察

目的应用封堵器治疗动脉导管未闭(PDA)伴重度肺动脉高压(SPH)患者,并评价其临床疗效。方法回顾性分析22例PDA合并SPH患者,应用国产封堵器封堵PDA,观察封堵前及封堵后肺动脉压力改变,术后24h及1、3、6个月行超声心动图、胸部正侧位片检查随访。结果19例封堵成功,PDA最窄处直径6.3￣11.0(8.2±3.6)mm。术前肺动脉收缩压为81￣128(97±26)mmHg,平均压为69￣102(80±23)mmHg,封堵后30min测肺动脉收缩压为45￣78(55±19)mmHg,平均压为42￣66(49±16)mmHg,较封堵前显著降低(P<0.05),3例PDA伴SPH者术中试封堵证实为阻力性肺动脉高压而未行封堵。封堵后30min降主动脉造影示16例封堵完全,无残余分流,3例存在微量残余分流。术后24h超声心动图示1例仍存在微量残余分流,1个月后所有患者均未见残余分流,术后未见溶血、封堵器脱落、移位及左肺动脉狭窄等并发症。结论应用封堵器治疗一些PDA伴SPH的患者是一种可行的、有效的介入方法。     

动脉导管未闭合并重度肺动脉高压Amplatzer法封堵治疗的临床应用--12例初步报告

目的评价Amplatzer封堵器治疗动脉导管未闭(PDA)合并重度肺动脉高压(SPH)的初步疗效.方法对12例(女9例,男3例)PDA合并SPH患者实施封堵治疗.其中10例采用Amplatzer动脉导管未闭封堵器,2例采用Amplatzer房间隔缺损封堵器.结果全组12例PDA封堵器均放置成功.11例PDA封堵后30分至1小时肺动脉收缩压、肺动脉平均压均明显降低.1例封堵术后即刻肺动脉压无变化.术后36小时彩色多普勒估测肺动脉压明显下降,封堵术后30分降主动脉造影,无残余分流9例,微量残余分流2例,少量残余分流1例.全组术后24～48小时彩色多普勒检查,动脉水平左向右分流均完全消失.无重要并发症发生.随访1～24个月(平均8个月),患者症状改善,11例心脏缩小,无1例发生再通.结论采用Amplatzer法封堵治疗PDA合并SPH,近期疗效满意.     

经食管超声心动图监测动脉导管未闭封堵术的应用价值

目的:探讨经食管超声心动图(TEE)在经胸小切口动脉导管未闭(PDA)封堵术中的应用价值。方法:封堵术前采用经胸超声心动图(TTE)初筛12例PDA患者,均符合封堵条件,仰卧位气管插管全麻后,沿食管将探头缓慢插入。手术前行TEE检查进一步明确PDA降主动脉侧及肺动脉侧内径、动脉导管长度及类型、血流方向,指导选择合适的封堵器。术中在TEE实时监测下行PDA封堵术,引导封堵器的正确放置,术后即刻评估封堵器的位置是否固定,是否有残余分流及并发症,术后3个月再行TTE随访。结果:TEE扫查下12例PDA均得到良好显示,其中7例为管型,5例为漏斗型,均适合封堵条件,在TEE的引导下成功完成封堵器的放置,并取得良好效果,动脉导管水平分流均完全消失,术后即刻及3个月随访均未见残余分流。结论:TEE对监测经胸小切口PDA封堵术中封堵器的放置及术后疗效评估起着重要作用。     

经导管堵闭婴幼儿大型动脉导管未闭(≥4mm)的短中期随访

目的分析经导管封堵婴幼儿大型动脉导管未闭(patent ductus arteriosus,PDA)(≥4 mm)的短中期随访的结果。方法回顾性分析50例大型PDA患儿的疗效、并发症及中期随访结果 ,评价其中期疗效、安全性及影响疗效的因素。结果成功植入封堵器49例(98%),其中46例(92%)应用PDA封堵器,2例(4%)应用肌部室间隔缺损封堵器,1例(2%)应用膜周对称型室间隔缺损封堵器。术后3 d内复查超声心动图:4例(8%)有残余分流;封堵后左心室舒张末内径、左心房内径、左心室射血分数、肺动脉收缩压、三尖瓣反流(tricuspidregurgitation,TR)及二尖瓣反流(mitral regurgitation,MR)均较术前缩小或减轻,差异有统计学意义(P<0.05);封堵后主动脉收缩压及主动脉瓣反流(aortic regurgitation,AR)较术前增加或加重,差异有统计学意义(P<0.01)。出院后完成随访41例,随访率81.6%,中位随访时间6个月(1～57个月)。残余分流率在术后3 d、1个月、6个月分别为8%、4%、2%。术后1～6个月内左心室射血分数较术后3 d有明显改善,差异有统计学意义(P=0.000);术后1年内随访:MR较术前降低,差异有统计学意义(P=0.000);AR及TR与术前比较,差异无统计学意义(P>0.05);术后1年内11例患儿出现左肺动脉血流速度加快(1.5～2.1 m/s),其中9例随访1年以上左肺动脉血流1.5～2.0 m/s,4例随访3～5年左肺动脉血流速度1.5～2 m/s,但左肺动脉至主肺动脉压差均≤20 mm Hg(1 mm Hg=0.133 kPa)。无降主动脉狭窄。结论经导管用封堵器治疗婴幼儿大型PDA(≥4 mm)的短中期疗效确切,安全性好,但对左肺血流速度增快患者需长期随访。     

经皮封堵治疗对先天性动脉导管未闭患者心脏结构的影响

目的评价国产封堵器封堵对先天性动脉导管未闭(PDA)患者近期心脏结构的影响。方法 2007-2009年80例PDA患者(男32例女48例),采用国产封堵器进行介入封堵治疗,比较手术前后肺动脉压力的变化,以及术后3 d、3个月、6个月、12个月后超声心动图参数的变化。结果未闭的动脉导管直径平均为(4.6±2.1)mm,应用封堵器的直径平均为(6.4±3.6)mm,5例患者术后即刻存在少量残余分流,余均封堵完全。肺动脉收缩压由术前(36.6±5.5)mm Hg降至(25.3±3.65)mm Hg(P<0.05),术后3 d超声心动图检查示除3例有微量残余分流外,其余封堵器位置固定良好,左室舒张末径和E/A值分别由术前的(48.6±8.3)mm和96±25/63±16降为(39.6±6.3)mm和78±13/52±10,其中年龄较大者E/A变化较明显,左室缩短分数由术前的38.7%±6.5%降为28.3%±5.9%,术后射血分数平均下降18.6%。72例完成术后12个月随访,封堵器均位置良好、无缺损,无肺动脉狭窄及主动脉缩窄。肺动脉内径、肺动脉血流速度、左房内径和左室收缩末径均有不同程度地下降,其中年龄小者肺动脉内径改变明显。结论国产封堵器用于PDA患者的封堵治疗可对心脏结构和功能产生积极影响,且早期治疗更佳。     

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。     

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。     

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.     

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.