乳果糖氢呼吸试验测定口-盲肠传递时间

目的测定功能性消化不良（ＦＤ）和肠易激综合征（ＩＢＳ）患者口－盲肠传递时间（ＯＣＴＴ）．方法应用乳果糖氢呼吸试验（ＬＨＢＴ）测定了正常人１３例，ＦＤ２０例和ＩＢＳ（其中１５例主诉腹泻，１６例主诉便秘）３１例患者的ＯＣＴＴ．结果正常人ＯＣＴＴ为９５４±１９６ｍｉｎ，ＦＤ患者（９９２±２４５ｍｉｎ）与正常人比较无显著性差异（Ｐ＞００５），但其中５例动力障碍型ＦＤ的ＯＣＴＴ则显著延长（１２９０±１２０ｍｉｎ，Ｐ＜００１），以便秘为主的ＩＢＳ患者ＯＣＴＴ显著延长（１５４４±５５７ｍｉｎ，Ｐ＜００１），以腹泻为主的ＩＢＳ患者ＯＣＴＴ显著缩短（７３１±２２２ｍｉｎ，Ｐ＜００５）．结论ＦＤ和ＩＢＳ患者存在小肠动力学异常，ＬＨＢＴ可作为辅助检查小肠动力学异常的手段之一．     

Small bowel transit time measured by hydrogen breath test in patients with anorexia nervosa

The gastrocecal transit time was measured in 10 patients suffering from anorexia nervosa,using a lactulose hydrogen breath test, and was compared with the orocecal transit time in 11 healthy controls. One of the 10 patients and one of the 11 controls were excluded from this study because of no discernible increase in hydrogen excretion. The transit time was significantly prolonged in patients with anorexia nervosa compared with controls (117 min ±31 sd vs 81 min + 33 SD, P <0.02). In addition to delayed gastric emptying, which has hitherto been well known, the small bowel transit time was considered to be prolonged in patients with anorexia nervosa. Both these abnormalities seem to contribute to the development of various gastrointestinal symptoms in patients with anorexia nervosa.     

山梨醇氢呼气试验测定口─盲肠通过时间及西沙比利对其影响的研究

目的对山梨醇氢呼气试验测定口─盲肠通过时间进行方法学研究，并观察西沙比利对健康人及患者口─盲肠通过时间的影响。方法以不同剂量的山梨醇作为试验糖并与泛影葡胺放射学方法进行对照。结果１５ｇ山梨醇的产氢率较高，副作用较少。山梨醇呼气氢试验测得的口─盲肠通过时间与泛影葡胺放射学方法的结果之间有显著的相关性（ｒ＝０．９１９）。十二指肠球部溃疡、慢性胃窦炎、肝硬化及糖尿病患者口─盲肠通过时间与正常对照组比较，差异有非常显著性（Ｐ均＜０．００１），服用西沙比利（１０ｍｇ，三次／日×３天），正常对照者、十二指肠球部溃疡、肝硬化及糖尿病患者口─盲肠通过时间显著缩短（Ｐ均＜０．００１）。结论（１）山梨醇呼气氢试验是简易、可靠、重复性好及非创伤性的测定口─盲肠通过时间的方法；（２）西沙比利可以显著缩短十二指肠球部溃疡、肝硬化及糖尿病患者的口─盲肠通过时间，其作用可能与加速胃排空，缩短小肠通过时间有关。     

Effect of loperamide and naloxone on mouth-to-caecum transit time evaluated by lactulose hydrogen breath test.

The effect of loperamide and naloxone on mouth-to-caecum transit time was evaluated by the lactulose hydrogen breath test in four men and four women. Each subject underwent tests during the administration of placebo, loperamide (12-16 mg po), naloxone (40 micrograms/kg/h by a three-hour intravenous infusion), and loperamide plus naloxone, carried out at intervals of one or two weeks. The transit time was significantly longer after loperamide, and this effect was antagonised by the concomitant administration of naloxone whereas naloxone administered alone had no effect on mean transit time. No clinically important side effects were reported.     

Reproducible lactulose hydrogen breath test as a measure of mouth-to-cecum transit time

Breath hydrogen monitoring after oral lactulose syrup is a conventional measure of mouth-to-cecum transit time (MCTT), but its reproducibility has been questioned. We compared the reproducibility of five measurements of MCTT after a conventional breakfast (380 kcal) taken with tea containing 20 g lactulose to five measurements of MCTT after 20 g lactulose in water in eight normal volunteers. Individual mean breakfast transit time was not significantly different from lactulose transit time in each of the seven subjects, but one had a breakfast transit time of 151±15 min and a lactulose transit time of 86±22 minutes (¯X ±sd, P<0.001). The coefficient of variation of breakfast transit time (11.6±5.3%, range: 6.9–24.2%) was less than that of lactulose transit time (30.7±7.8%, range: 22.1–50.0%, P<0.001). In a second set of experiments, the liquid phase marker ( ^99m Technetiumdiethylene triamine pentaacetic acid) emptied from the stomach more rapidly after the lactulose solution (T1/2 16.3±5.4) than after the breakfast (33.9±10.9 min, P<0.01) and MCTT was shorter after lactulose (77±32 vs 104±40 min, trespectively, P<0.05). There was no correlation between MCTT of lactulose and breakfast and between half-time gastric emptying and MCTT of either lactulose or breakfast. We conclude that the ingestion of inert lactulose induces an abnormally rapid MCTT and that breakfast MCTT is a much more reproducible investigation and should be employed in studies requiring serial measurements.     

Lactulose hydrogen breath test in orocecal transit assessment

Orocecal transit time can be studied easily using the hydrogen breath test with lactulose, but the method has some important limitations. The orocecal transit time of 10 patients suffering from irritable bowel syndrome was measured twice, at a one-week interval, by breath test and scintigraphy simultaneously using an aqueous solution of 20 g lactulose containing 74 MBq of [^99mTc]DTPA. Abdominal radioactivity and alveolar hydrogen values obtained every 5 min were noted and used to obtain the following: orocecal transit time by the two methods; ileocecal lactulose flow; total and per gram of lactulose hydrogen production; mean hydrogen concentration during the right colon filling; and measurement error of the breath test with respect to the scintigraphy. In the case of the breath test, the orocecal transit time intrapatient reproducibility was better (coefficient of variation =13.5%) when a hydrogen threshold increment of 5 ppm was used; the best correlation with the scintigraphic measurement was observed at this threshold (r=0.90,P<0.001). The breath test overestimated orocecal transit time with the error correlating negatively and significantly with the total hydrogen production and, particularly, the mean hydrogen concentration (r=0.79,P<0.01): for a mean hydrogen concentration of more than 15 ppm, the error was negligible, while within this value there was a noticeable overestimation. To conclude, the lactulose hydrogen breath test is capable of giving an accurate measurement of orocecal transit time if a hydrogen threshold increment of 5 ppm is chosen and if the mean hydrogen concentration in the first 30 min of the right colon filling is taken into account.     

Small bowel transit time measured with native lactulose breath hydrogen test]

Native lactulose was used in breath hydrogen test (BHT) to detect small bowel transit time (SBTT) in normal persons (34 cases) and patients with functional diarrhea (24 cases) and functional constipation (12 cases). The mean SBTT was 80.6 +/- 28.3 min, 58.4 +/- 42.2 min and 104.2 +/- 21.0 min respectively. When the mean SBTT in the patient groups was compared with that in the normal group, there was statistically significant difference (P less than 0.05 and 0.01 respectively). The results showed that native lactulose produces hydrogen successfully (94.3%). Few side-effects were found, if a dose of 10g was used.     

Comparison of orocaecal transit times assessed by the lactulose/breath hydrogen and the sulphasalazine/sulphapyridine methods.

The lactulose/breath hydrogen and the sulphasalazine/sulphapyridine methods of assessing orocaecal transit time have been compared. In a two part crossover study in healthy normal subjects the median orocaecal transit time by the SLZ/SP method was 4.84 hours but only 2.92 hours by the lactulose/breath hydrogen method. Coadministration of lactulose and sulphazalazine to nine subjects with assessment of orocaecal transit time by hydrogen breath determination and plasma sulphapyridine assay gave orocaecal transit times of 2.33 and 2.25 hours respectively suggesting that the lactulose reduces transit time and that the lactulose/breath hydrogen method, which is so convenient to use, gives artificially low transit times. A third experiment was undertaken to compare the orocaecal transit times after 1.5 and 3.0 g sulphazalazine. The orocaecal transit times after the two doses were not statistically different.     

Breath hydrogen as a test for gastrointestinal transit

Intestinal transit is an important indicator of small-bowel function. This study served to investigate oro-cecal and duodeno-cecal transit times of different carbohydrate test meals and to evaluate intra- and interindividual variability of the breath hydrogen test. Breath hydrogen was analysed by an electrochemical cell in 25 healthy volunteers. Oro-cecal transit time of lactulose was much shorter than that of a standardized normal test meal. Duodeno-cecal transit was approximately one hour shorter than oro-cecal transit. Considerable intra- and interindividual differences were observed. It is concluded that results of lactulose test meals do not permit conclusions as to the physiological situation. Large intra- and interindividual variability of transit times must be taken into account in any study using the breath hydrogen test.     

Reproducibility of orocecal transit time and hydrogen production measured by breath tests]

The hydrogen breath test after a lactulose oral load in the fasting period is currently used to measure mouth to cecum transit time (MCTT). However, the reproducibility of this test is poor, and normal values are very scattered. The aim of the study was to determine the reproducibility of hydrogen breath test for MCTT measurement and hydrogen production after administration of 2 disaccharides: lactulose and lactitol ingested in the fasting state and postprandial period. Twelve healthy volunteers (6 men and 6 women; mean age = 34.6 +/- 9.6 years) were studied eight times in a random order, each disaccharide being studied twice in the fasting state and twice in the postprandial period. In the later, lactulose or lactitol was ingested 30 min after a liquid meal completely absorbed (400 kcal; glucide: 55 p. 100, lipid: 30 p. 100, protein: 15 p. 100; 400 ml of Inkopeptide). The MCTT was significantly increased with both disaccharides in the postprandial period as compared with the fasting state (P less than 0.0001). There was nos significant correlation between the 2 measurements of the MCTT in the fasting state, in contrast, the 2 measurements of the MCTT were closely related in the fed state (r = 0.62, P less than 0.05, et r = 0.79, P less than 0.003 for lactulose and lactitol respectively). During both periods no significant difference was found in the MCTT between lactulose and lactitol. As well, hydrogen production did not differ between the 2 disaccharides, but was significantly increased in the postprandial period, and in non methane producers.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of L-tryptophan on fasting intestinal motility and intestinal transit time in the human

Since previous experiments in dogs suggested L-tryptophan to disturb the migrating motor complex (MMC) we set out to study its effects in man. In six healthy volunteers intraduodenal instillation of 50 mmol L-tryptophan did not disrupt the interdigestive motility pattern. In comparison to saline L-tryptophan caused a brief and local increase of motor activity in the upper small bowel. There was no change in small bowel transit time. The oral intake of 560 kcal liquid formula diet produced a typical digestive pattern for 160-209 min. The increase and the maximum of serum gastrin levels did not correspond to the changes of motor activity.     

Scintigraphic determination of gastrointestinal transit times. A comparison with breath hydrogen and radiologic methods.

A scintigraphic method for determination of gastrointestinal transit times was compared with the breath hydrogen test and a multiple-bolus, single-radiograph technique. A close temporal association was found between the caecal appearance of radioactivity and the onset of breath hydrogen excretion in eight healthy subjects. Neither mean small-intestinal nor mean orocaecal transit times of the radiolabelled marker were correlated with the magnitude of hydrogen peak, hydrogen peak time, or the area under hydrogen curve. No correlation was noted between whole-gut transit time of the radiolabelled marker and mean whole-gut transit time calculated from a 6-day administration of the radiopaque marker in 16 healthy subjects. The stool weight was inversely correlated with the mean colonic (r = -0.46, p = 0.009) and the mean whole-gut (r = -0.45, p = 0.011) transit times of the radiolabelled marker. In conclusion, inadequate delineation of the caecal region seems to be an unimportant drawback of the scintigraphic measurements, whereas day-to-day variation in gastrointestinal transit rates may influence the reliability of the assessments. Probably, quantitative transit data cannot be obtained from the breath hydrogen concentration profiles.     

The effect of gastric secretion on orocoecal transit time measured with the hydrogen (H2) breath test

Orocoecal transit time was studied by means of a hydrogen (H2) breath test after a standard meal in patients with peptic disease before and during treatment with ranitidine, in patients with gastric achlorhydria, and in healthy acid-secreting volunteers. Treatment with ranitidine prolonged the orocoecal transit time in patients with peptic disease from 201.9 +/- 18.3 (SEM) to 242.3 +/- 18.3 min (p less than 0.05). Also in patients with achlorhydria, the orocoecal transit time was prolonged (276.2 +/- 20.3 min), compared to the control group of healthy acid-secreting volunteers (213.5 +/- 15.7 min), (p less than 0.05). The orocoecal transit time did not correlate with gastric bacterial concentrations in the groups investigated, nor with the subjects' age. It was not correlated to the pH in the gastric juice of acid-secreting individuals, either with or without treatment. As gastric emptying was not evaluated in this study, it is impossible to state whether gastric stasis or inhibited small bowel motility, or both, cause the delayed transit in achlorhydria and during treatment with ranitidine. We suggest that the reduction of gastric juice volume could be the cause.     

Effect of dietary fiber on gastrointestinal motility and jejunal transit time in dogs

Strain gauge recordings of the motility of the antrum, duodenum, and jejunum were made in 10 dogs receiving a daily meal of canned food. Addition of 30 g of either wheat bran, cellulose, or guar gum increased the duration of the postprandial pattern of motility by 41-54% in the duodenum. Only cellulose and gum caused increases in the duration of the postprandial pattern of motility in the jejunum. The normal postprandial pattern of duodenojejunal contractions consisted of bursts of 4-10 rhythmic contractions. When bran or cellulose were added, the bursts were prolonged (12-15 contractions per burst) with 4-15 min intervals between bursts. In contrast, when gum was added, contractions occurred continuously at a rate of 7-8/min, but their amplitude was one-half that seen with the other fibers. The increased number of low amplitude contractions when gum was added caused the postprandial motility index to double. There was no change in the motility index when cellulose was added. Guar gum also increased the frequency of antral contractions by 129%, while bran and cellulose had no effect. Jejunal transit time and flow of digesta were measured in four dogs 2 h after the meal. Addition of bran or gum increased the transit time by 28% and 51%, respectively, but cellulose caused a 900% increase in transit time associated with a 50% reduction in the flow of digesta. Addition of different fibers causes different alterations in postprandial motility. Jejunal transit of digesta appears unrelated to the pattern of contractions.     

Statistical analysis of the lactulose/breath hydrogen test in the measurement of orocaecal transit: its variability and predictive value in assessing drug action.

The variability in the orocaecal transit time as measured by the lactulose/breath hydrogen method has been studied for three conditions: lactulose given with a meal, subjects sitting; lactulose given with a meal, subjects semirecumbent; lactulose given in aqueous solution, subjects semirecumbent. Thirty three healthy subjects attended on up to 12 occasions. It was found that administration of the lactulose with a meal significantly reduced the variability (p less than 0.05) and that adoption of the semirecumbent position further reduced variability. A power analysis was used to predict the number of subjects who would be required to show a given percentage change in orocaecal transit time at specified probabilities and powers. A graph and a table for use in the prediction of subject numbers at a probability of 5% and for powers of 50-99% is presented. A dose response curve for metoclopramide using the lactulose/breath hydrogen method is given for doses of 10, 15, and 20 mg.     

Scintigraphic determination of small intestinal transit time: comparison with the hydrogen breath technique

The hydrogen breath test was used as a standard against which a scintigraphic method for determination of small intestinal transit time was evaluated and compared. A total of 19 male volunteers ranging in age from 23 to 28 yr participated in the study. The subjects ingested an isosmotic lactulose solution containing 99mtechnetium-diethylenetriaminepentaacetic acid (Sn) and then remained supine under a large field of view gamma-camera that interfaced with a computer system. Data were visually analyzed and then quantified to determine gastric emptying and small intestinal transit time. The small intestinal transit time ranged from 31 to 139 min with the scintigraphic method and 30 to 190 min with the hydrogen breath test (r = 0.77). The mean small intestinal transit time for 20 individual determinations with the scintigraphic method, 73.0 +/- 6.5 min (mean +/- SEM), was similar to the results from the hydrogen breath test technique, 75.1 +/- 8.3 min. Thirteen volunteers underwent two studies with the scintigraphic method separated by intervals ranging from 2 days to 8 wk. Individual variations in small intestinal transit time were significantly correlated with individual variations in gastric emptying (p less than 0.05). We conclude that the scintigraphic method allows accurate determination of gastrocecal time and is a noninvasive technique which may be a useful clinical test for small intestinal transit time as well as for providing information on the pathophysiology and pharmacology of intestinal motility.     

Repeatability of lactulose hydrogen breath test in subjects with normal or prolonged orocecal transit

The within-subject repeatability of orocecal transit assessed with lactulose hydrogen breath test was evaluated in 15 healthy volunteers and 16 constipated or obese patients. The test was repeated twice in each subject. Mean (SD) transit time was 105 (63) and 103 (60) min in the first and second series of tests, respectively, showing that the first measurement did not affect the second. The within-subject repeatability of the test was related to the length of transit, the scatter of the differences between the first and second test being greater with the increase of the mean gastrointestinal transit time. The 95% coefficient of repeatability was 84 min for all measurements and 30 and 118 min, respectively, for transit times under and over 100 min. The lowest reproducibility of the test was found in constipated patients with prolonged orocecal transit.     

Effect of iron succinyl-protein complexes on gastrointestinal motility in the fasting dog.

Studying the gastrointestinal motor effects of iron compounds may help to elucidate the mechanism originating the gastrointestinal side effects of frequently reported during martial therapy. The aims of the present study were: (1) to examine the gastrointestinal motor effects of ferrous sulfate (reference compound) and (2) to compare its effects with those of two iron succinyl-protein complexes (ITF 1096 and ITF 282, an iron-albumin and iron-casein complex, respectively). In 6 fasting, conscious dogs, fitted with 8 bipolar electrodes and 3 strain-gauge force transducers along the gastrointestinal tract, gastrointestinal motor activity was recorded. Ferrous sulfate and iron succinyl-protein complexes were administered by an orogastric tube at two dose levels: the lower and higher dose levels were approximately equivalent to 10 and 30 mg/kg as Fe, respectively. In control experiments, 154 mM NaCl, ITF 211 (succinylated albumin) and ITF 297 (succinylated casein) were used. Administration of 154 mM NaCl did not affect gastrointestinal motility nor did it disrupt migrating motor complex (MMC) cycling. ITF 1096 and ITF 282, only at the higher dose, lengthened the MMC period and increased intestinal, but not gastric spike activity. The effects of ITF 211 and ITF 297 were similar to those of ITF 1096 and ITF 282. Ferrous sulfate, at the lower dose, lengthened the MMC period; the higher dose disrupted MMC cycling and induced intense, irregular spike bursts in the stomach and in the small bowel, accompanied, in 3 out of 6 dogs, by a prolonged tonic contraction of the upper small bowel. Four out of 6 dogs vomited after the higher dose of ferrous sulfate. No vomiting was observed with any of the other treatments. We conclude that ITF 1096 and ITF 282 have a markedly better gastrointestinal tolerability than ferrous sulfate.     

The hydrogen (H2) breath test. Sampling methods and the influence of dietary fibre on fasting level

Three end-expiratory breath hydrogen (H2) sampling methods were compared in a patient group (n = 12) and a laboratory staff group (n = 12) on two separate occasions. H2 samples obtained with each method showed significantly different concentrations (p less than 0.001) but no significant differences in coefficient of variation when individual triplicate samples were evaluated. There was a high correlation between the breath H2 concentrations obtained by the three methods (r = 0.93-0.96). Fasting breath H2 values after an overnight fast and an unrestricted diet the day before the investigation were compared with values obtained after an overnight fast and a low-fibre diet the day before the test in two patient groups (n = 39 and 39) with a comparable distribution of diagnoses and in one group of healthy volunteers (n = 17). Fasting breath H2 concentrations were significantly lower after a low-fibre diet in the patient groups (p less than 0.005) and in healthy volunteers (p less than 0.02). We conclude that each of the three end-expiratory sampling methods can be chosen for use in H2 breath tests depending on suitability and convenience and that a low-fibre diet the day before the H2 breath test lowers fasting breath H2 concentration.