不透X线标志物法和13C-辛酸呼气试验法检测胃固体排空的评价

目的 比较不透X线标志物法（ROMs）和^13C-辛酸呼气试验法（OBT）检测胃固体排空方法的相关性。方法 对32例胆汁反流性胃炎（BRG）组和27例对照组（HC）同时应用^13C-辛酸呼气试验及不透X线标志物法进行胃排空检测,将所测参数输入计算机,用专用软件分析。结果 不透X线标志物法与^13C-辛酸呼气试验法测定的胃排空结果具有很好的相关性（P〈0．001）,两种检测方法均显示BRG组的固体胃排空较HC组明显延迟（P〈0．05）。结论 不透X线标志物法是一种非侵入性检测胃固体排空的方法,操作简单,与^13C-辛酸呼气试验法比较,具有较好的敏感性、特异性及准确性。BRG患者有明显的胃排空延迟,这可能是其发生病理性胆汁反流的一个重要原因。     

呼气试验在消化内科中的应用

呼气试验的原理是应用核素^13C和^14C标记底物，通过口服进人人体，利用质谱仪或能谱仪检测最终产物^13CO2和^14CO2的变化以了解体内代谢反应及生理过程。近年来呼气试验在消化内科领域被广泛应用于幽门螺杆菌感染检测、胰腺外分泌功能检测、肝脏储备功能检测、胃排空检测、小肠吸收功能检测等，因其非侵入性、简单、方便受到人们的青睐。     

幽门螺杆菌感染的诊断——^13C—尿素呼气试验

应用^13C—尿素呼气试验诊断幽门螺杆菌已经十余年，临床实践征明该试验是一种快速、准确、无痛苦的检测方法，本就^13C-—尿素呼气试验的原理、适应症、与其他几种检到方法的比较及影响因素作一综述。     

两种13C-尿素呼气试验试剂诊断幽门螺杆菌感染临床可靠性比较

^13C-尿素呼气试验快捷、无创伤，敏感性和特异性高。在临床上被广泛应用于幽门螺杆菌(H.pylori)感染的检测。从加拿大进口的^13C-尿素试剂已获得国家食品药品监督管理局许可并应用于临床。目的：与加拿大进口的^13C-尿素试剂进行比较，评估美国Isotec公司生产的^13C-尿素试剂用于诊断H.pylori感染的临床可靠性。方法：114例因上消化道症状接受胃镜检查者随机分为A、B两组。取胃窦活检标本分别作快速尿素酶试验、组织学检查和H．pylori培养．三项中有两项或以上阳性，或H．pylori培养单项阳性判为H．pylori感染，否则判为无H．pylori感染。以此作为诊断H．pylori感染的金标准。A组使用加拿大进口的^13C尿-素试剂，B组使用美国Isotec公司生产的^13C-尿素试剂，分别进行^13C-尿素呼气试验。根据金标准分别计算和比较两组^13C-尿素呼气试验的准确性、敏感性、特异性和阳性预测值、阴性预测值。结果：A组^13C-尿素呼气试验诊断H．pylori感染的准确性为92．8％，敏感性为94．1％，特异性为90．9％，阳性预测值为94．1％，阴性预测值为90．9％；B组准确性为98．3％。敏感性为96．9％，特异性为100％，阳性预测值为100％，阴性预测值为96.3％。两组上述各项指标均无显著差异。结论：A组和B组^13C-尿素呼气试验诊断H．pylori感染的准确性、敏感性、特异性和阳性预测值、阴性预测值均较高．美国Isotec公司生产的^13C-尿素试剂用于临床诊断H．pylori感染结果可靠。     

13C-嘧噻西叮呼气试验对肝脏储备功能的诊断价值

目的探讨^13C-嘧噻西叮呼气试验用于肝脏储备功能检测的临床价值。方法将69例肝硬化患者分为Child A、B、C三组,另设7例为对照组。采集受试者不同时间点的呼气标本并检测^13C丰度,绘制丰度（delta over baseline,DOB）曲线、代谢速率（metabolisation velocity,MV）曲线和累积丰度（cumulated dose,CUM）曲线。结果随着Child—Pugh分级的升高,DOB、MV峰值出现时间延长,峰值降低（P〈0．05）,CUM曲线趋于低平;参数与部分常规肝功能检查呈相关性（P〈0．05）。结论^13C-嘧噻西叮呼气试验能够有效地反映肝细胞损伤情况和肝脏储备功能。     

呼气试验在消化系统疾病中的应用

呼气试验的原理是通过口服同位素碳（13^C或^14C）标记的底物后，根据不同标记底物在体内代谢过程中限速酶作用的位置以及底物代谢的最终产物标记同位素CO2的变化来研究机体内不同的代谢反应和生理过程。不同标记底物的代谢过程不同，可以反映不同的器官功能状态。除大家熟知的尿素呼气试验可检测幽门螺杆菌感染外，呼气试验还可以检测肝细胞功能、胃排空功能、胰腺外分泌功能、脂肪吸收功能、     

^13C-辛酸呼气试验对反流性食管炎患者胃排空功能的检测

[目的]以^13C-辛酸呼气试验对反流性食管炎患者胃排空功能进行检测,探讨其胃动力学变化及其与内镜分级的相关性。[方法]入选确诊为反流性食管炎的患者68例,按内镜Ⅰ、Ⅱ、Ⅲ分级分为Ⅰ级组、Ⅱ级组、Ⅲ级组;同时入选健康志愿者25例作为对照组。在空腹口服^13C-辛酸后,收集检测结果计算患者DOB曲线达峰时间（Tmax）^13CO2代谢速率峰值（MVmax）、240min^13CO2累积呼出丰度（CUM240）、胃半排空时间（T1／2）和延迟相时间（Tlog）。[结果]各患者组Tmax、T1／2和Tlog均显著延长（其中Ⅲ级组最长）,MVmax、CUM240均显著降低（其中Ⅲ级组最低）,与对照组相比差异均有统计学意义。[结论]反流性食管炎胃排空功能与内镜分级呈高度相关性,随着内镜分级的增加,胃排空功能相应延迟。     

13C-辛酸呼气试验评估糖尿病胃固体排空功能的研究

目的探讨老年2型糖尿病患者胃固体排空功能及其与心血管自主神经功能的关系。方法老年2型糖尿病组71例，正常对照组30例，应用^13C-辛酸呼气试验技术检测胃固体排空功能，并行心血管自主神经功能评估。结果（1）糖尿病患者胃半排空时间（GET1／2）、延迟相（Tlag）及120min胃残留率（Ret120min）明显高于正常对照组（P均〈0．01）；（2）糖尿病患者胃排空延迟患病率高于正常对照人群（P〈0．01）；（3）糖尿病合并胃排空延迟者心血管自主神经病变患病率明显高于胃排空正常糖尿病患者（P〈0．05）；（4）糖尿病组GET1/2与心血管自主神经功能积分呈显著正相关（r=0．353，P〈0．01）。结论（1）老年2型糖尿病患者胃动力明显下降，胃固体排空延迟常常与心血管自主神经病变合并存在。（2）^13C-辛酸呼气试验是检测胃排空的理想选择。     

^13C-美沙西定呼气试验定量评估肝硬化病人肝功能及与部分生化指标相关性的研究

目的 探讨^13C-美沙西定呼气试验对肝硬化病人肝功能状况评估及与部分临床生化指标相关性。方法 随机选取肝硬化病人68例，隔夜空腹服用^13C-美沙西定75mg后，通过呼气质谱仪检测10个时间段呼出的^13CO2含量，得出DOB曲线、MV曲线及CUM曲线，MVmax30及CUM30、CUM120值，并与常规肝生化指标及Child—Pugh评分进行相关性分析。结果 MVmax30及CUM30、CUM120在对照组及肝硬化Child A、B、C各组间差异有显著性（P〈0．05），MVmax30及CUM30、CUM120与部分肝功能生化指标及Child—Pugh评分有明显相关性。结论 ^13C-美沙西定呼气试验是一种安全而精确的定量评估肝功能方法。     

13C-美沙西丁呼气试验对亚临床肝性脑病的临床价值分析

目的探讨13C-美沙西丁呼气试验对亚临床肝性脑病(SHE)发病率和预后判断等方面的临床应用价值.方法随机选择72例肝硬化患者和31例正常人作为研究对象,对所有受试者进行数字连接试验和智商(IQ)检测,以明确有无SHE,并同步进行13C-美沙西丁呼气试验、血氨等检测.比较13C-美沙西丁呼气试验的肝功能分级与临床Child Pugh分级的关系;采用多因素相关分析,比较13C-美沙西丁呼气试验的分级指标、血氨指标对并发SHE的关系;随访所有肝硬化患者的13C-美沙西丁呼气试验分级结果与SHE的关系.结果肝硬化患者13C-美沙西丁呼气试验的肝功能分级与临床Child Pugh分级的差别无统计学意义(P＞0.05).13C-美沙西丁呼气试验分级为病理性肝损害、Child Pugh A级的两组肝硬化患者中无SHE,SHE患者均出现在13C-美沙西丁呼气试验分级为Child B级或Child C级且血氨值为(90.56±13.66)μmol/L或更高的患者中.在肝硬化患者13C-美沙西丁呼气试验的肝功能分级中,Child C级中SHE的发病率高于Child B级(P＜0.05).随访发现,13C-美沙西丁呼气试验为Child B级和Child C级患者存在并发SHE的危险.结论13C-美沙西丁呼气试验可作为SHE发病的重要评判因素之一并有助于对肝硬化并发SHE的预后判断.     

13C-breath tests: current state of the art and future directions.

13C-breath tests provide a non-invasive diagnostic method with high patient acceptance. In vivo, human and also bacterial enzyme activities, organ functions and transport processes can be assessed semiquantitatively using breath tests. As the samples can directly be analysed using non-dispersive isotope selective infrared spectrometers or sent to analytical centres by normal mail breath tests can be easily performed also in primary care settings. The 13C-urea breath test which detects a Helicobacter pylori infection of the stomach is the most prominent application of stable isotopes. Determination of gastric emptying using test meals labelled with 13C-octanoic or 13C-acetic acid provide reliable results compared to scintigraphy. The clinical use of 13C-breath tests for the diagnosis of exocrine pancreatic insufficiency is still limited due to expensive substrates and long test periods with many samples. However, the quantification of liver function using hepatically metabolised 13C-substrates is clinically helpful in special indications. The stable isotope technique presents an elegant, non-invasive diagnostic tool promising further options of clinical applications. This review is aimed at providing an overview on the relevant clinical applications of 13C-breath tests.     

Gastric Emptying is Altered with the Presence of Gastritis

Helicobacter pylori infection and gastritis can cause symptoms suggestive of altered gastrointestinal function; however, it is unclear if H. pylori influences gastric motility. This study assessed gastric emptying rates in mouse models of gastritis. Gastritis was induced in C57BL/6 mice via ethanol treatment or via challenge with H. pylori or H. felis. Gastric emptying rates of nutrient and non-nutrient liquids were assessed with the non-invasive ¹³C-breath test, and the results were compared to healthy mice. Gastric emptying of the non-nutrient liquid was unaltered with the presence of gastritis; however, gastric emptying of the nutrient liquid was accelerated after a 4-week infection with H. pylori. H. felis infection and ethanol treatment caused a more severe gastritis and disruptions to the normal gastric emptying. Changes to gastric emptying in mouse models of gastritis are associated with the presence of nutrients. Altered gastric emptying may contribute to symptoms commonly reported in humans with gastritis.     

Clinically relevant breath tests in gastroenterological diagnostics--recommendations of the German Society for Neurogastroenterology and Motility as well as the German Society for Digestive and Metabolic Diseases

H (2)- and (13)C-breath tests are valuable non-invasive diagnostic tools for gastroenterological diseases. H (2)-breath tests are clinically established for the diagnosis of carbohydrate intolerance resulting from malabsorption (H (2)-breath tests with lactose, fructose, saccharose, sorbitol), of bacterial overgrowth (glucose H (2)-breath test) and for measurement of orcoceal transit time (lactulose H (2)-breath test). The (13)C-urea breath test is regarded as the "gold standard" procedure for the diagnosis of Helicobacter pylori infection. Moreover, (13)C-breath tests for measurement of gastric emptying can be considered as clinically established, meanwhile. (13)C-breath tests for the evaluation of pancreatic exocrine function or liver function can also be used clinically; however, they currently offer no substantial advantage over other diagnostic procedures. A major disadvantage of all breath tests is that they lack standardization although modifications of the test meal or solution, of the test performance and of the evaluation of data may markedly influence the results. Thus, this article presents the recommendations of the German Society of Neurogastroenterology and Motility and of the German Society of Digestive and Metabolic Diseases for clinically relevant H (2)- and (13)C-breath tests. Indications for the examinations, the procedures to be followed, the analysis of the obtained data and the conclusions to be drawn are delineated. The literature on which the recommendations are based is reviewed. However, personal experience of the authors is also taken into account since numerous questions regarding optimal test performance are not clarified by adequate studies.     

13C-Bicarbonate Breath Test as a Measure of Gastric Emptying

Radionuclide studies are widely used to estimate the gastric emptying rate of solids and liquids. Unfortunately, these methods carry the risk of radiation exposure and require expensive and complex equipment. Carbon-13, a stable, nonradioactive isotope, has been used successfully as a marker in the gastrointestinal tract for other purposes. A preliminary study using ingested NaH13CO3 and measuring 13CO2 breath excretion suggested that this test might be a simple, noninvasive, and inexpensive method for determining gastric emptying. To determine the efficacy of NaH13CO3 as a noninvasive marker for gastric emptying, the resulting 13CO2 breath excretion was determined simultaneously with standard radiolabeled meal measurements of gastric emptying of liquids and solids in 15 patients. 13CO2 breath excretion did not correlate with the gastric emptying of either solids or liquids, as determined by radionuclide techniques. These results suggest that NaH13CO3 is not a reliable indicator of gastric emptying. Factors other than gastric emptying may affect the rate of 13CO2 absorption and exhalation, rendering it unreliable as a measure of gastric emptying.     

13C-呼气试验评估胰腺外分泌功能的临床应用

三酰甘油、蛋白质和淀粉均可作为13C-呼气试验的底物，用于检测胰腺外分泌功能。目前研究最多的是13C-三酰甘油呼气试验，其中以13C-混合三酰甘油呼气试验（MTG—BT）最具优势。N-苯甲酰-L-酪胺酰-【1-13C】丙氨酸（Bz—Tyr—Ala）呼气试验无需试餐，近年逐渐受到关注。13C-淀粉呼气试验影响因素较多，研究近况不甚理想。本文对各类，13C-呼气试验的底物特点及其评估胰腺外分泌功能的临床应用作一综述。     

Nondispersive infrared spectrometry for 13CO2/12CO2-measurements: a clinically feasible analyzer for stable isotope breath tests in gastroenterology.

BACKGROUND: 13C-urea breath tests have become clinical routine for the diagnosis of Helicobacter pylori infection and other isotope breath tests have been invented e.g. for gastric emptying or quantitative liver function testing. Recently, isotope-selective nondispersive infrared spectrometers (NDIRS) have been developed for the analysis of the 13CO2/12CO2-enrichment in breath. In this study, we prospectively tested the validity of a newly developed NDIRS in comparison to isotope ratio mass spectrometry (IRMS). METHODS: 142 patients with dyspeptic symptoms were tested for Helicobacter pylori infection using the 13C-urea breath test. The isotope ratio analysis of the breath samples was performed in duplicate both using IRMS and NDIRS. RESULTS: The results of the baseline-corrected 13CO2-exhalation values between IRMS and NDIRS were in excellent agreement. The mean difference between both methods was 0.28 +/- 1.93 delta/1000. Evaluating the qualitative urea breath test results in reference to IRMS as the reference the NDIRS had a sensitivity of 97.8% and a specificity of 98.9%. CONCLUSION: The isotope-selective nondispersive infrared spectroscopy is going to become a reliable, but low-cost and easy-to-operate alternative to expensive isotope ratio mass spectrometry in the analysis of 13C-breath tests.     

肝硬化患者血浆胆囊收缩素及胃动素对胃排空的影响

目的本研究旨在探讨肝硬化患者胃排空功能,并探讨其胃排空作用与空腹血浆胆囊收缩素、胃动素的关系,进而为预防和治疗肝硬化提供参考。方法 将30例肝硬化患者作为试验组,30例健康志愿者作为对照组,采用^13C-辛酸呼气试验法测定肝硬化患者以及对照组的胃固体半排空时间（GET1／2）,同时用放射免疫技术测定患者及对照组的空腹血浆胆囊收缩素（CCK）及胃动素（MTL）水平。结果与健康志愿者组相比,肝硬化患者组GET1／2明显延迟（P〈0．05）;空腹血浆CCIK及MTL水平明显升高,组间差异有统计学意义（P〈0．05）;患者GET1／2与空腹血浆CCK及MTL水平各自呈正相关。结论肝硬化患者胃排空延迟可能与血浆CCK及MTL水平的异常增高相关。推测肝硬化时血浆CCK及MTL水平均明显增高,由此引发胃排空延迟,最终导致营养不良,进而加重患者病情。     

Reliability of the [13C]-acetate breath test in the measurement of gastric emptying of ethanol solutions: a methodological study

BACKGROUND: The [13C]-acetate breath test is a clinically well-established test for measuring gastric emptying of liquids and correlates significantly with scintigraphy. However, no studies have been undertaken to examine the relationship between gastric emptying measured by the [13C]-acetate breath test and ultrasonography. Furthermore, it is not known how ethanol may affect gastric emptying as measured by the [13C]-acetate breath test. This is particularly important because of the additional steps of absorption, metabolism and exhalation of the tracer involved in the [13C]-acetate breath test compared to the simple measurement of gastric emptying by ultrasonography. The aim of the present study was to examine the relationship between the gastric half emptying times measured by the [13C]-acetate breath test and by ultrasonography and to determine the effect of ethanol on the comparability between both methods. METHODS: On separate days, 10 healthy, fasted randomly selected subjects received the following solutions by gastric tube: 500 mL water, 4% and 10% (v/v) ethanol, 5.5% and 11.4 % (w/v) glucose. Gastric half emptying times of the test solutions were simultaneously determined using the [13C]-acetate breath test and ultrasonography of the fundus and the antrum. RESULTS: The gastric emptying rates determined by ultrasonography of the fundus correlated significantly with the results obtained using the [13C]-acetate breath test for all test solutions (r = 0.64-0.92, P < 0.05 for all), whereas ultrasonography of the antrum correlated significantly with the breath test only when water (r = 0.94, P = 0.001) was used. The difference between the mean half-emptying times obtained using the [13C]-acetate breath test and ultrasonography of the fundus was 55 +/- 1.8 min. This difference was significantly longer when 4% and 10% (v/v) ethanol solutions were given (61.2 +/- 3.3 and 71.2 +/- 2.9 min) compared to water (P < 0.05). CONCLUSIONS: A good correlation was found between gastric emptying as measured by the [13C]-acetate breath test and ultrasonography of the fundus. Measurements that were obtained using the [13C]-acetate breath test demonstrate a longer gastric half emptying time compared with those obtained using ultrasonography. This difference is even more marked when ethanol solutions are used. Presumably, this is because ethanol affects the absorption and/or the hepatic metabolism of the tracer. The [13C]-acetate breath test is therefore not a reliable gastric emptying test for comparison of different solutions, especially when ethanol-containing liquids are used.     

Gastric emptying: a comparison of three methods

OBJECTIVE: A better understanding of the clinical relevance of delayed gastric emptying (e.g. in diabetes) requires a simple, easily accessible and inexpensive method for measuring it. Two "new" methods for measuring gastric emptying of liquids (the paracetamol absorption test and the 13C-acetate breath test) are compared with the gold standard (gastric emptying scintigraphy (GES)). MATERIAL AND METHODS: The three techniques were used simultaneously in 10 healthy subjects. A gastric emptying time-retention curve was drawn for each technique and the results were compared at the 75%, 50% and 25% retention quartiles. RESULTS: Agreement was found between the paracetamol absorption test and GES (p=0.95; Hotelling's T 2 test). Using the Wagner-Nelson one compartment correction produced a retention curve for the 13C-acetate breath test statistically significantly below GES (p<0.01). CONCLUSION: In healthy subjects, the paracetamol absorption test produced results comparable to those of liquid GES, but not to the results of the 13C-acetate breath test.     

Effects of Helicobacter pylori eradication therapy on gastric emptying measured using the 13C-octanoic acid breath test and the acetaminophen method

BACKGROUND: The relationship between Helicobacter pylori eradication and gastric emptying has been reported; however, the effect of eradication therapy on gastric emptying is still unclear. This study evaluated the relationship between three gastric emptying techniques, the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method, measured simultaneously, and the effect of H. pylori eradication therapy on gastric emptying and abdominal symptoms in patients with functional dyspepsia who were H. pylori positive. METHODS: Fifty-three consecutive patients with positive H. pylori infection were enrolled in this study. In the first 14 patients, gastric emptying was measured using the three gastric emptying techniques. In 42 patients cured of H. pylori infection, the 13C-octanoic acid breath test and the acetaminophen method were performed before and 3 months after eradication. RESULTS: Significant correlations were found between the scintigraphic technique, the 13C-octanoic acid breath test, and the acetaminophen method. Gastric emptying determined by the 13C-octanoic acid breath test and the acetaminophen method was not changed after eradication, on average. In 14 (33.3%) patients a decrease in symptom score after eradication was observed. In four (9.5%) patients, accelerated gastric emptying after eradication may have led to a reduction in the abdominal symptoms. CONCLUSIONS: The 13C-octanoic acid breath test and the acetaminophen method are appropriate for investigating gastric emptying. A causal relationship between improvement of symptoms and accelerated gastric emptying was not found, and the efficacy of H. pylori eradication therapy in patients with functional dyspepsia was minimally exhibited.