贝凡洛尔治疗原发性高血压的疗效和安全性评价

目的随机、开放、平行对照的比较评价两种选择性β1受体阻断剂(贝凡洛尔/美托洛尔)治疗原发性高血压的疗效和安全性.方法选择原发性高血压患者136例,随机分为两组服用贝凡洛尔100 mg～200 mg/d或美托洛尔100 mg～150 mg/d,每日分二次治疗共8周,根据需要4周末调整剂量.分别比较两组药前、后第2、4、6、8周末坐位血压和心率的变化.结果口服盐酸贝凡洛尔(100～200 mg/d,分两次)治疗原发性高血压,药后2、4、6、8周平均SeDBP降低值分别为8.9±6.4 mmHg、7.9±7.1 mmHg、10.0±8.2 mmHg、11.00±8.2 mmHg;平均SeSBP降低值分别为8.8±11.4 mmHg、10.6±12.0 mmHg、8.6±14.2 mmHg、10.3±14.8 mmHg.美托洛尔组(100～150 mg/d,分两次).药后2、4、6、8周平均SeDBP降低值分别为8.1±9.2 mmHg、7.7±8.6 mmHg、10.4±7.9 mmHg、10.7±8.4 mmHg;平均SeSBP降低值分别为7.1±13.9 mmHg、7.5±13.3 mmHg、10.9±13.2 mmHg、11.3±13.9 mmHg.服药前后降压值两组内比较均P=0.00,组间比较无统计学差异.贝凡洛尔单药治疗原发性高血压病患者70.97%需要服用200 mg/d.两组治疗后心率均较基线下降,贝凡洛尔组于治疗4周后心率下降幅度有统计学差异,美托洛尔组于治疗2周后心率下降幅度有统计学差异 .两组药后24小时内平均心率变化趋向降低.两药治疗4、8周后心电图窦性心率与QT、RR和PP等相关的指标在临床允许范围有变化.对血脂、血糖的代谢影响与其它β受体阻滞剂相似.贝凡洛尔组不良反应发生率10.29% (7/68例),美托洛尔组不良反应发生率23.53% (16/68例),两组不良反应发生率有显著性差异(P=0.04).美托洛尔组出现窦性心动过缓5例,窦性停搏1例,2例因窦性心动过缓退出研究.贝凡洛尔组无心律失常的发生.两药均未发现对房室传导的影响.结论贝凡洛尔治疗原发性高血压的疗效肯定,耐受性较好.     

动态血压监测比较两种β1受体阻滞剂的降压疗效

目的 :用动态血压监测 (ABPM )的方法比较两种 β1受体阻滞剂———贝凡洛尔 (bevantolol)与美托洛尔 (metoprolol)治疗原发性高血压的疗效。方法 :选择原发性高血压患者 5 0例 ,随机分为贝凡洛尔组 2 4例 ,美托洛尔组 2 6例。分别观察服药前和服药后 8周末的 2 4h、白昼、夜间及各时点的动态血压变化。结果 :贝凡洛尔组和美托洛尔组服药前、服药后 8周末的 2 4h、白昼和夜间的平均收缩压、舒张压明显下降 ,有显著性差异(P <0 0 5或P <0 0 1)。贝凡洛尔组服药后 8周末各时点收缩压和舒张压均较服药前下降 ,有显著性差异 (P <0 0 5 )。美托洛尔组服药后 8周末各时点的收缩压和舒张压较服药前下降 ,但服药后的第 2 3～ 2 4h血压下降不明显 (P >0 0 5 )。结论 :贝凡洛尔 ( 10 0～ 2 0 0mg/d ,分两次口服 )可维持 2 4h平稳降压 ;美托洛尔 ( 10 0～ 15 0mg/d ,分两次口服 )仅能维持 2 2h内血压下降。     

伊贝沙坦治疗原发性高血压的疗效和安全性评价

目的评价伊贝沙坦(irbesartan)治疗轻、中度原发性高血压的疗效和安全性.方法选取137例坐位舒张压(SeDBP)95～115mmHg(1mmHg＝0.133kPa)[根据1993年<新药(西药)临床研究指导原则>治疗前舒张压水平分成轻(95～104mmHg)、中(105～114mmHg)和重(＞115mmHg)三类]的轻、中度原发性高血压患者,随机分为伊贝沙坦组(150mg每日1次)和贝那普利(benazepril)组(10mg每日1次).于4周末SeDBP≥90mmHg者剂量分别加倍,继续服用4周.于安慰剂期末及治疗2、4、6、8周测诊室血压、心率并记录症状、体征;试验前后行实验室检查.结果有效率伊贝沙坦组81.2%,贝那普利组70.5%,两组比较无显著性差异(P＞0.05).8周伊贝沙坦组及贝那普利组SeSBP/SeDBP均下降,其中2、4、6、8周伊贝沙坦组SeDBP的下降幅度大于贝那普利组,两组有显著性差异(4周P＜0.05,2、6、8周P均＜0.01).贝那普利组咳嗽5例,发生率8%.结论伊贝沙坦150～300mg/d治疗轻、中度原发性高血压的有效率近似于贝那普利10～20mg/d,但耐受性好于贝那普利.     

贝风洛尔与美托洛尔治疗I、Ⅱ级原发性高血压病的比较

目的：观察新药贝凡洛尔的降压疗效并与美托洛尔作对照。方法：选择I、Ⅱ级高血压病病人43例，经2周安慰剂清洗后，采用随机、单盲、平行对照方法，其中贝凡洛尔组23例，口服贝凡洛尔50－100mg,bid；美托洛尔组20例，口服美托洛尔50－75mg,bid。疗程均为8周，同时观察两组的血压、心率、血糖、血脂、肝肾功能。结果：（1）贝凡洛尔与美托洛尔比较，两组各自降压幅度差别均有非常显著性意义（P＜0．01）但疗效比较无显著性意义（P＞0．05）；（2）用药后两组心率均减慢（P＜0．01），但贝凡洛尔减慢较少（P＜0．01）；（3）两组各项血生化指标治疗前后判别均无显著性意义（P＞0．05），不良反应均较轻且可耐受。结论：贝凡洛尔是治疗I、Ⅱ级高血压病的有效和安全的药物，贝凡洛尔对心率的变化的影响略优于美托洛尔。     

比索洛尔与美托洛尔治疗高血压病疗效的对比研究

目的　对比观察比索洛尔和美托洛尔治疗轻、中度高血压患者的临床疗效与安全性。方法　采用随机、开放、平行对照方法 ,观察比索洛尔 (n =1 1 5)每日 2 5～ 7 5mg或加双氢克尿噻 1 2 5mg,美托洛尔 (n =1 0 5)每日 50～ 1 50mg或加双氢克尿噻 1 2 5mg治疗 6周和 8周的有效率。 结果　两组治疗第 2周开始平均收缩压 (SBP)、舒张压(DBP)和心率 (HR)较治疗前均明显降低 (P <0 0 1 ) ;在整个治疗期间血压和HR持续平稳下降 ,治疗后 2～ 8周血压下降值比索洛尔组为 1 1 0 / 8 6～ 2 1 6/ 1 6 2mmHg ,美托洛尔组为 1 1 0 / 8 8～ 1 6 7/ 1 4 9mmHg ;HR下降值前组为5 1～ 8 9次 /分 ,后组为 4 8～ 7 3次 /分 ;服药第 8周比索洛尔组降低SBP优于美托洛尔组 (P <0 0 1 ) ,其它两组间比较无明显差异 (P均 >0 0 5)。比索洛尔和美托洛尔治疗 6周降低血压的总有效率分别为 84 3 %和 79 0 % (P >0 0 5) ;8周加双氢克尿噻总有效率分别为 91 3 %和 81 0 % (P <0 0 5) ,比索洛尔加利尿剂可组提高降压疗效 7%。动态血压监测 (ABPM)显示比索洛尔降低夜间SBP优于美托洛尔 (P <0 0 1 ) ;比索洛尔T/P比值 >50 %。结论　比索洛尔是一种有效、高选择性 β1 受体阻滞的长效降压药 ,副作用轻微 ,耐受性好。联合应用小     

贝凡洛尔与美托洛尔治疗Ⅰ、Ⅱ级原发性高血压病的比较

目的:观察新药贝凡洛尔的降压疗效并与美托洛尔作对照。方法:选择Ⅰ、Ⅱ级高血压病病人43例,经2周安慰剂清洗后,采用随机、单盲、平行对照方法,其中贝凡洛尔组23例,口服贝凡洛尔50～100mg,bid;美托洛尔组20例,口服美托洛尔50～75mg,bid。疗程均为8周,同时观察两组的血压、心率、血糖、血脂、肝肾功能。结果:(1)贝凡洛尔与美托洛尔比较,两组各自降压幅度差别均有非常显著性意义(P<0.01)但疗效比较无显著性意义(P>0.05);(2)用药后两组心率均减慢(P<0.01),但贝凡洛尔减慢较少(P<0.01);(3)两组各项血生化指标治疗前后差别均无显著性意义(P>0.05),不良反应均较轻且可耐受。结论:贝凡洛尔是治疗Ⅰ、Ⅱ级高血压病的有效和安全的药物,贝凡洛尔对心率的变化的影响略优于美托洛尔。     

贝凡洛尔与美托洛尔治疗Ⅰ、Ⅱ级原发性高血压病的比较

目的观察新药贝凡洛尔的降压疗效并与美托洛尔作对照.方法选择Ⅰ、Ⅱ级高血压病痛人43例,经2周安慰剂清洗后,采用随机、单盲、平行对照方法,其中贝凡洛尔组23例,口服贝凡洛尔50～100mg,bid;美托洛尔组20例,口服美托洛尔50～75mg,bid.疗程均为8周,同时观察两组的血压、心率、血糖、血脂、肝肾功能.结果(1)贝凡洛尔与美托洛尔比较,两组各自降压幅度差别均有非常显著性意义(P＜0.01)但疗效比较无显著性意义(P＞0.05);(2)用药后两组心率均减慢(P＜0.01),但贝凡洛尔减慢较少(P＜0.01);(3)两组各项血生化指标治疗前后差别均无显著性意义(P＞0.05),不良反应均较轻且可耐受.结论贝凡洛尔是治疗Ⅰ、Ⅱ级高血压病的有效和安全的药物,贝凡洛尔对心率的变化的影响略优于美托洛尔.     

动态血压监测评价贝尼地平治疗原发性高血压的疗效观察

目的　应用动态血压监测 (ABPM )的方法评价贝尼地平治疗原发性高血压的降压疗效、谷 /峰比值及不良反应。方法　采用开放的方法 ,2 0例研究对象经 2周洗脱期 ,服用贝尼地平 4mg/d一次 ,2周末坐位舒张压 (SeDBP)≥ 90mmHg者加量至贝尼地平 8mg/d一次 ,继续服用 6周。于洗脱期末及治疗 8周末各行ABPM和实验室检查一次。结果　ABPM显示 8周末 2 4h、日间、夜间收缩压 (SBP/DBP)较洗脱期末分别下降 (9.4± 5 .4 / 6 .2± 4 .1)mmHg、(10 7± 6 .7/ 6 8± 3 8)mmHg、(6 9± 9 0 / 5 1± 7 7)mmHg。降压T/P值SBP为 5 8% ,DBP为 5 9%。无严重不良反应。 结论　贝尼地平 4～ 8mg/d一次为疗效确切的降压药物。     

比索洛尔与美托洛尔治疗高血压病疗效的对比研究

目的对比观察比索洛尔和美托洛尔治疗轻、中度高血压患者的临床疗效与安全性.方法采用随机、开放、平行对照方法,观察比索洛尔(n=115)每日2.5～7.5 mg或加双氢克尿噻12.5 mg,美托洛尔(n=105)每日50～150 mg或加双氢克尿噻12.5 mg治疗6周和8周的有效率.结果两组治疗第2周开始平均收缩压(SBP)、舒张压(DBP)和心率 (HR) 较治疗前均明显降低(P<0.01);在整个治疗期间血压和HR持续平稳下降,治疗后2～8周血压下降值比索洛尔组为11.0/8.6～21.6/16.2 mmHg,美托洛尔组为11.0/8.8～16.7/14.9 mmHg;HR下降值前组为5.1～8.9次/分,后组为4.8～7.3次/分;服药第8周比索洛尔组降低SBP优于美托洛尔组(P<0.01),其它两组间比较无明显差异(P均>0.05).比索洛尔和美托洛尔治疗6周降低血压的总有效率分别为84.3%和79.0%(P>0.05);8周加双氢克尿噻总有效率分别为91.3%和81.0%(P<0.05),比索洛尔加利尿剂可组提高降压疗效7%.动态血压监测(ABPM)显示比索洛尔降低夜间SBP优于美托洛尔(P<0.01);比索洛尔T/P比值>50%.结论比索洛尔是一种有效、高选择性β1受体阻滞的长效降压药,副作用轻微,耐受性好.联合应用小剂量利尿剂可提高疗效.     

贝凡洛尔和美托洛尔对原发性高血压患者心率变异性的影响

目的:研究贝凡洛尔和美托洛尔对原发性高血压患者心率变异性的影响。方法:53例原发性高血压患者洗脱2周后,随机口服贝凡洛尔(n=26,贝凡洛尔组)100～200 mg/日,分两次口服,或美托洛尔(n=27,美托洛尔组)100～150 mg/日,分两次口服,治疗8周。服药前后行24小时动态心电图检查各1次,分析24小时时域和5分钟频域指标。结果:服药后贝凡洛尔组24小时长程时域指标:相邻RR间期之差的均方根(rMSSD),全部RR间期中相邻RR间期之差大于50 ms的心搏数除总的RR间期个数乘以100(PNN_(50))均较用药前增加,有显著性差异(P<0.05～0.01);5分钟短程频域指标:高频(HF)增加,低频(LF)/HF下降,与用药前比较有显著性差异(P<0.05)。而美托洛尔组24小时长程时域指标:rMSSD较用药前增加,有显著性差异(P<0.05),5分钟短程频域指标:HF较用药前增加,LF/AF则降低,均有显著性差异(P<0.05),组间比较无统计学差异。结论:与美托洛尔相比,具轻度α_1受体阻滞作用的高选择性β_1受体阻滞剂贝凡洛尔,同样改善原发性高血压患者的心率变异性。     

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.