Oesophageal sensitivity to acid in patients with non-cardiac chest pain: is the oesophagus hypersensitive?

During the past decade, gastro-oesophageal reflux disease has been shown to be the most common identifiable cause of non-cardiac chest pain of oesophageal origin. The development of combined pH-pressures recording systems has also contributed to a better understanding of the underlying mechanisms of pain perception. Beside typical gastro-oesophageal reflux disease, many patients with non-cardiac chest pain appear to have an hypersensitivity to acid or mechanical stimuli, or both. Despite new insights into the pathophysiology of gastro-oesophageal reflux disease, therapy is limited to the suppression of noxious stimuli by antisecretory drugs or surgery. New therapeutic approaches using drugs affecting visceral perception, and well-controlled placebo trials are urgently needed.

Multicentre prospective controlled study of Barrett's oesophagus and colorectal adenomas. Groupe d'Etude de l'Oesophage de Barrett

Previous studies have suggested that patients with Barrett's oesophagus may be at increased risk of colorectal neoplasia, though the association is disputed. In a multicentre prospective study we compared the prevalence of colorectal adenomas in patients with Barrett's oesophagus and controls. Barrett's oesophagus patients (n = 104) had histological confirmation of columnar epithelium extending more than 3 cm above the gastro-oesophageal junction. The 537 controls were patients with symptoms suggesting irritable bowel syndrome. No participant had a personal history of colonic neoplasm. Each patient underwent colonoscopy. Histologically proven adenomas were found in 26 Barrett's patients (25%) and 75 controls (14%). Three colorectal cancers were discovered in each group. The prevalence of adenomas was greater in the Barrett's oesophagus group than in the control group (p < 0.01) but the relation became non-significant after adjustment for age and sex and control for other known risk factors by a logistic regression model (odds ratio 1.4 [0.7-2.7]). The relative risk of adenoma was significantly higher in patients older than 59 than in younger patients (2.2 [1.3-3.5]) and in men than in women (3.4 [2.0-5.7]). Other factors contributing significantly to the risk of adenoma were a family history of colorectal cancer (2.3 [1.1-4.8]), rectal bleeding (2.1 [1.1-3.9]), previous colonic investigation (0.3 [0.1-0.7]), and complete as opposed to partial colonoscopy (6.4 [0.8-48.3]). We conclude that Barrett's oesophagus is not an independent risk factor for colorectal neoplasia and, therefore, is not, in itself an indication for colorectal screening.

Gastric relaxation in response to a soup meal in healthy subjects. A study using a barostat in the proximal stomach

BACKGROUND

Meal-induced relaxation of the proximal stomach can be investigated by means of a barostat. Using a standard liquid meat soup that elicits symptoms and a wide antrum in patients with functional dyspepsia, we aimed at finding the best meal size and fat load for studying gastric relaxation.

METHODS

In the first trial 200 ml and 500 ml meat soup (1 g fat/200 ml) was given to six healthy individuals. In the second trial a constant volume of soup (200 ml) containing graded amounts of fat (1, 10, and 20 g/200 ml) was given to seven healthy individuals. Gastric relaxation was investigated for 1 h after consumption of the soup. A sagittal cross-sectional antral was assessed ultrasonographically every 10 min, and abdominal discomfort was scored.

RESULTS

Overall, a positive response (volume increase of 30 ml or more within 5 min after consumption of the meal) was found in 26 of 30 (87%) investigations. Individual maximal responses ranged from 38 to 482 ml (mean, 180 ml +/- 128). Area under the time-volume curve (AUC) was similar after 200 and 500 ml soup (mean, 100 ml/30 min and 107 ml/30 min, respectively). AUC increased with increasing fat content, with a significant difference between the low-fat and high-fat meal (p < 0.05). The barostat bag induced fed-state antral contractions in most individuals (p < 0.001). There was a negative correlation between AUC and postprandial abdominal discomfort (p = 0.04).

CONCLUSIONS

The barostat is a sensitive technique for detecting gastric relaxation, also in response to our standard meat soup meal. The postprandial relaxation response in healthy individuals in dependent on the fat content of the meal. The barostat bag may alter gastric motor activity. Abdominal discomfort after soup ingestion may be related to poor gastric relaxation.

Peptide YY release after intraduodenal, intraileal, and intracolonic administration of nutrients in rats

Peptide YY (PYY) release was studied by measuring radioimmunoassayable PYY in the arterial plasma of anaesthetized rats receiving into the duodenum, ileum or colon either a complete semi-liquid meal (3ml, 21kJ) or elemental nutrients as isocaloric or isoosmolar solutions. PYY release induced by the intraduodenal meal peaked at 60min and lasted more than 120min. The integrated response of PYY over 120min was larger when the meal was administered into the duodenum than into the ileum. The undigested meal induced no release of PYY over a 120-min period when administered into the colon. When injected into the duodenum in isocaloric amounts to the meal, glucose and amino acids led to the release of as much PYY as did the meal, whereas oleic acid led to the release of less PYY. Part of these responses were due to osmolarity, since administration of intraduodenal hyperosmolar saline led to the release of about half as much PYY as did hyperosmolar glucose. In moderate amounts, and injected as a solution isoosmolar to plasma, oleic acid was a major PYY releaser; the amounts released were at least two times larger when oleic acid was administered into the duodenum than into the ileum and colon. Isoosmolar glucose and amino acids led to the release of no PYY when injected into the duodenum, but were nearly as active as oleic acid in the colon. Short-chain fatty acids induced the release of PYY when injected into the colon, but not into the ileum. Hexamethonium suppressed PYY release induced by the intraduodenal meal, but did not change PYY release induced by glucose or oleic acid in the colon. Urethane anaesthesia did not reduce PYY release induced by the intraduodenal meal. These results suggest that two mechanisms at least contribute to PYY release in the rat. An indirect, neural mechanism, involving nicotinic synapses, is prominent in the proximal small intestine; the stimulation is transmitted to ileal and colonic L-cells by undetermined pathways, but contact of nutrients with L-cells is not needed. Another mechanism, probably direct and quantitatively smaller, occurs in the distal intestine when nutrients come into contact with the mucosa containing L-cells. Glucose, fatty acids and amino acids stimulate differentially the proximal and distal mechanisms.

A new technique for continuous measurement and recording of gastric potential difference in the rat: evaluation of NSAID-induced gastric mucosal damage

Disruption of the gastric mucosal barrier by the so-called "barrier breakers" such as ethanol, aspirin, and bile is associated with an increase in gastric potential difference (GPD), that is, a decrease in its negativity. Because a good correlation between the degree of histological damage and changes in GPD has been observed, this parameter has been used increasingly as an index of mucosal integrity. However, the current methodology for measuring GPD is laborious due to the preparation and checking of KCl-agarose bridges prior to each experiment, and calculations--usually handmade--are time-consuming and inaccurate. In this paper, a new method allowing simultaneous measurement and recording of GPD in the rat is described. The method allows a simultaneous recording of intragastric pH and an automatic data analysis. The new technique has been validated by studying mucosal damage induced by aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) (namely indomethacin and droxicam) as well as the mucosal protective activity of an antacid and sucralfate. The similarity between the results obtained in this rat model and those derived from human experiments clearly show that the developed methodology yields results that are predictive for human pharmacology.

Reflux related symptoms in patients with normal oesophageal exposure to acid

Several studies, using pH monitoring with event markers, have identified patients with normal oesophageal exposure to acid despite an apparent relation between symptoms and reflux episodes. In this series of 771 consecutive patients referred for 24 hour oesophageal pH monitoring, a probability calculation was used to evaluate the relation between symptoms and reflux episodes. Oesophageal exposure to acid was normal in 462 of 771 recordings (59.9%); despite this, 70.8% (327 of 462) of these patients used at least once the event marker. In 96 patients (12.5% of total patients) with normal oesophageal exposure to acid, there was a statistically significant association between symptoms and reflux episodes. The symptom cluster of such patients was similar to that usually seen in patients with gastro-oesophageal reflux disease, but symptoms like belching, bloating, and nausea were common thus overlapping with the symptom pattern of functional dyspepsia. In these patients both the duration and the minimum pH of reflux episodes (either symptom related or asymptomatic) were significantly shorter and higher, respectively, when compared with those of patients with gastro-oesophageal reflux disease. These results are consistent with the idea that oesophageal hypersensitivity to acid is the underlying pathophysiological feature of this syndrome.

[Expression of the gene of cholecystokinin. Demonstration from duodenal biopsies in man]

Cholecystokinin (CCK) is a peptide released after feeding. Until now, CCK gene expression has been studied only on sacrified animals on mucosa scrapped off the duodenum. OBJECTIVE--The aim of this study was to assess CCK-mRNA detection on duodenal biopsy specimens in subjects undergoing gastrointestinal endoscopy. METHODS--Six biopsy specimens were taken from 6 healthy subjects, a) after a 12-h overnight fast and b) 6 or 12 h after a fat meal, and inducing a CCK release. CCK-mRNA was analyzed by Northern blot. RESULTS--Plasma CCK levels increased from basal levels of 0.5 +/- 0.1 pmole/L to 8.2 +/- 1.5 pmole/L 10 min after the meal. The fasting CCK-mRNA levels were 44.0 +/- 0.6% and the post-prandial levels increased to 74.0 +/- 6.0% at 6 h and decreased to 47.5 +/- 0.5% at 12 h. CONCLUSIONS--Detection of CCK gene expression in human duodenal biopsy specimens is feasible. Stimulation of CCK release after a meal is followed by an increase in CCK-mRNA in the duodenal mucosa.

Erythromycin enhances fasting and postprandial proximal gastric tone in humans

BACKGROUND & AIMS

Low doses of erythromycin induce antral contractions and accelerate gastric emptying. However, the effect of erythromycin on the proximal stomach remains unknown. The aim of this study was to assess the effect and mechanism(s) of action of erythromycin on proximal gastric tone in humans.

METHODS

Gastric tone was measured using an electronic barostat in two groups of 6 subjects both in the fasting state and after a 200-kcal meal. On different occasions, subjects received saline, atropine alone (6 micrograms.kg-1.h-1 for 30 minutes), erythromycin alone (1.5 mg/kg in the fasting state and 1.5 and 3.0 mg/kg in the postprandial state), and erythromycin plus atropine.

RESULTS

Low-dose (1.5 mg/kg) erythromycin enhanced fasting gastric tone, but only the 3.0-mg/kg dose reduced the duration of meal-induced relaxation (37 +/- 14 vs. 105 +/- 20 minutes; P < 0.01). Atropine did not change the fasting or postprandial gastric tone as well as the erythromycin-induced responses. Plasma motilin levels were unaffected by erythromycin infusion. No correlation was observed between gastric tone and plasma motilin or erythromycin levels.

CONCLUSIONS

Erythromycin enhances fasting and postprandial proximal gastric tone in humans by a mechanism that does not seem to involve endogenous motilin release or a cholinergic pathway.

Transmucosal potential difference as an index of esophageal mucosal integrity

All the epithelia lining the gastrointestinal (GI) tract, including that of the esophagus, exhibit a transmucosal electrical potential difference (PD). The luminal surface of the GI mucosa is indeed electrically negative when compared with the serosal one. Although it was initially felt that the body of the esophagus exhibits a PD near 0 or slightly positive, recent studies, using parenteral reference electrodes, have shown a negative PD of around -15 mV. Measurement of esophageal PD has been mainly used to locate both the lower and the upper esophageal sphincters but very rarely to evaluate esophageal mucosal integrity in clinical settings, most probably due to the difficulties encountered during measurement of mucosal PD. Reliable techniques to measure esophageal PD simultaneously with esophageal pressure or mucosal pH are now available. Application of these recently developed methodologies showed that measurement of esophageal PD during either manometry or endoscopy provides meaningful information about mucosal integrity. Indeed, tissue injury, either neoplastic of inflammatory, usually results in a less negative PD. In contrast, an abnormally high negative PD is very often observed in patients with columnar-lined lower esophagus. In patients with microscopic reflux esophagitis, PD exhibits less negative values which are significantly correlated with the degree of the mucosal damage. Normalization of the altered PD after either medical or surgical treatment makes it an additional parameter to evaluate the effect of a given therapy.

The pathophysiology of gastro-oesophageal reflux disease: an overview

Gastro-oesophageal reflux disease (GORD) is a multifactorial disease. Although it is primarily a motility disorder, several other disturbances can interfere and contribute to determine the severity of symptoms and the degree of lesions. In normal subjects, as in patients with pathological reflux, nearly all the episodes of reflux obey one of the following three mechanisms: (a) a transient complete relaxation of the lower oesophageal sphincter (TLOSR), (b) a transient increase in intra-abdominal pressure which overcomes the resistance of the antireflux barrier ('stress reflux') and, (c) a spontaneous reflux through a permanently hypotonic sphincter. Gastric distension is the major factor that can induce TLOSRs. Whereas, at rest, the diaphragm probably plays little role in cardial competence, diaphragmatic contraction may help prevent reflux in conditions resulting in increased abdominal pressure such as during physical activity and abdominal staining. The presence of a hiatal hernia increases susceptibility to reflux. A delayed gastric emptying may also facilitate reflux and represents a factor of resistance to antireflux therapy. Most studies in humans have shown that motor abnormalities remain unchanged after healing of oesophagitis. Acid and pepsin are the most noxious agents of the upper gastrointestinal secretions that can participate in the pathogenesis of oesophagitis. However, there is no evidence that patients with reflux have greater acid secretion than subjects without reflux. The clearance function is a two-stage phenomenon requiring first a reduction in volume by peristalsis and then chemical neutralization by saliva. Primary peristalsis is mainly responsible for the clearance of acid in both the upright and the supine positions. It takes longer to clear acid in patients with non-reducing hiatal hernia. The layer of mucus which carpets the mucosa comes from the saliva and also from the submucosal glands of the oesophagus. The paracellular pathway is the major route by which mucosal HCl enters and then damages the oesophageal epithelium. Only a minority of acid reflux episodes are accompanied by symptoms. The acid exposure during the time period that precedes a reflux episode (i.e. the acid burden) is a key factor determining whether that reflux episode will be symptomatic or asymptomatic.

Digestion of raw banana starch in the small intestine of healthy humans: structural features of resistant starch

The digestion of freeze-dried green banana flour in the upper gut was studied by an intubation technique in six healthy subjects over a 14 h period. Of alpha-glucans ingested, 83.7% reached the terminal ileum but were almost totally fermented in the colon. Structural study of the resistant fraction showed that a small part of the alpha-glucans which escaped digestion in the small intestine was composed of oligosaccharides from starch hydrolysis, whereas the rest was insoluble starch in granule form with physical characteristics similar to those of raw banana starch. Passage through the small intestine altered granule structure by increasing susceptibility to further alpha-amylase hydrolysis. Compared with resistant starch values in vivo, those obtained with the in vitro methods tested were inadequate to estimate the whole fraction of starch reaching the terminal ileum.

An interleukin 2/sodium butyrate combination as immunotherapy for rat colon cancer peritoneal carcinomatosis

BACKGROUND/AIMS

Immunotherapy using interleukin 2 has had disappointing results in the treatment of colon cancer. Overcoming escape mechanisms, such as lack of antigen presentation and absence of accessory adhesion molecules on cancer cells, may increase its efficiency. We tried to do so by modifying the phenotype of the weakly immunogenic rat colon cancer PROb cells with sodium butyrate.

METHODS

After in vitro treatment with butyrate, PROb cells were tested for lymphokine-activated killer cell sensitivity and, using cytofluorometry, expression of adhesion molecules. We then treated established PROb peritoneal carcinomatoses with intraperitoneal injections of interleukin 2 and butyrate. Tumors were studied histologically and immunohistochemically. We tested the specificity of the immune protection by subsequent subcutaneous challenges with either PROb or glioma cells and by Winn's assay.

RESULTS

Butyrate increased lymphokine-activated killer cell sensitivity and expression of major histocompatibility complex class I and intercellular adhesion molecule 1 in vitro. Interleukin 2/butyrate combination resulted in cases of complete cure of carcinomatosis with specific protection against PROb cells. We noticed a complex stroma reaction with numerous functional antigen presenting cells close to PROb cells.

CONCLUSIONS

The complete regression of tumor masses may be attributed, at least in part, to a butyrate-induced increase in immunogenicity of the cancer cells. This new combined immunotherapy may be of interest in the treatment of colon cancer.

Alosetron does not affect the visceral perception of gastric distension in healthy subjects

BACKGROUND

The effect of alosetron, a new specific 5-HT3 receptor antagonist, on the visceral perception in response to gastric distension was assessed in 12 healthy male subjects in a randomized, double-blind, placebo controlled crossover trial.

METHODS

Each subject was given orally either alosetron 1 mg b.d. or placebo b.d. for 6 days (wash-out period 7-28 days). At the end of each dosing period, both isobarometric and isovolumetric gastric distensions were performed using an electronic barostat.

RESULTS

Alosetron did not modify the gastric wall compliance (pressure-volume relationship). Alosetron had an effect similar to placebo on the visceral perception scores in both isobarometric and isovolumetric distensions. The mean (+/- SEM) thresholds for abdominal discomfort were, respectively, 16.8 +/- 0.7 mmHg and 825 +/- 61 mL with alosetron, 16.7 +/- 0.6 mmHg and 883 +/- 45 mL with Placebo (P = NS).

CONCLUSIONS

5-HT3 receptors do not appear to be involved in the visceral perception of gastric distension in healthy subjects.

Comparison of lansoprazole with omeprazole on 24-hour intragastric pH, acid secretion and serum gastrin in healthy volunteers

BACKGROUND

Lansoprazole and omeprazole are proton pump inhibitors which both strongly inhibit acid secretion, resulting in a significant increase in serum gastrin levels. However, no direct comparison of recommended doses (20 mg for omeprazole and 30 mg for lansoprazole) has been reported so far. Our aims were to compare the effects of omeprazole 20 mg/day and lansoprazole 30 mg/day on intragastric acidity and serum gastrin concentration in 12 healthy volunteers.

METHODS

The study was double-blind, randomized and placebo-controlled with a cross-over design. On the seventh day of each period, 24-hour intragastric pH was measured using a combined glass electrode placed in the proximal stomach. The last morning dose of each regimen was taken at the end of 24-hour pH monitoring; acid output and serum gastrin concentrations were then studied in the fasting state and after stimulation with pentagastrin (maximal acid output) and a meal (post-prandial gastrin response).

RESULTS

Compared to placebo, both drug regimens induced a sustained increase of 24-hour intragastric pH and significantly decreased basal and pentagastrin-stimulated acid secretion. Lansoprazole 30 mg was slightly more effective than omeprazole 20 mg in terms of time spent above pH 3 (P < 0.05). Accordingly postprandial gastrin concentrations rose slightly more after lansoprazole than after omeprazole. All other differences were insignificant.

CONCLUSIONS

Both lansoprazole 30 mg and omeprazole 20 mg induce potent and long-lasting acid inhibition, with few minor differences when the two proton pump inhibitors are used at standard doses.

Involvement of small intestinal motility in blood glucose response to dietary fibre in man

Three dietary fibres with different physicochemical properties were studied in healthy humans for their effects on small intestinal motility and postprandial hyperglycaemia. Duodeno-jejunal motor activity was evaluated electromyographically for 180 min in six subjects who had ingested a test meal composed of glucose alone or glucose with 15 g of wheat bran (WB), sugar beet (SB) or ispaghula (I) fibres. Glucose and insulin concentrations were determined during the same period. Each subject received each of the four test meals randomly during a 4 d period. Addition of SB or I to the glucose meal altered duodeno-jejunal motility. Both of these fibres inhibited stationary contractile activity and increased the propagation length and velocity of propagated activity, whereas addition of WB had no effect. These results could reflect the high water-holding capacity of SB and I. Blood glycaemic response to the glucose meal was reduced by SB and I but remained unchanged with WB. Postprandial blood glucose levels were significantly correlated with the total motility index (r 0.82) and stationary activity (r 0.79). Taken together, these observations suggest that the contractile activity induced by dietary fibre in the small intestine probably plays a major role in delayed glucose absorption.

Role of viscous guar gums in lowering the glycemic response after a solid meal

The aim of the present study was to investigate how guar gum viscosity acts on starch digestion and glucose absorption in humans. Six healthy subjects received a mixed diet composed of 60.4% carbohydrate in the form of maize glucose or pregelatinized starch, to which was added 5.6% low- or high-viscosity guar gums. Meals were ingested or instilled in the duodenum and postprandial insulin and glucose responses were monitored for 3 h. Infusion of meals containing glucose showed that the delay in the diffusion rate to the duodenal mucosa due to bolus viscosity was not significant. Infusion of meals containing starch showed that a decrease in the digestion rate of starch in the upper small intestine accounted for part of the effect of viscosity on glycemic response, whereas the main effect of guar gum was apparently to slow gastric emptying.

Symptoms and disease severity in gastro-oesophageal reflux disease

The definition of criteria relevant to disease severity assessments should be considered in parallel with the long-term aims of treatment in gastro-oesophageal reflux disease (GORD). There is no doubt that the resolution of symptoms is the major management aim. Heartburn and regurgitation are specific for GORD when they are the predominant symptoms, but prove to be insensitive when the diagnosis of GORD is based on the measurement of oesophageal acid exposure. A relationship between the frequency of heartburn and the degree of acid exposure has been reported in GORD patients both with and without oesophagitis. GORD may also, however, cause a wide spectrum of atypical symptoms (e.g. non-cardiac chest pain or respiratory symptoms). To the extent that a causal relationship between these symptoms and reflux episodes has been established, evaluation of symptom severity should also encompass these atypical presentations. The role of symptoms in the prediction of relapse of oesophagitis is controversial, but in several studies the presence of residual symptoms of GORD at the time of healing has indicated a greater probability of relapse. Endoscopy is a useful technique for the evaluation of disease severity. Indeed, even typical symptoms may not predict the presence and severity of oesophagitis in an individual patient. Despite the fact that the interpretation of therapeutic trials is often impeded by differences in the grading systems used, healing rates of oesophageal lesions are inversely proportional to the initial severity of oesophagitis when drugs such as H2-receptor antagonists are used. Differences are less evident with highly effective drugs such as omeprazole.(ABSTRACT TRUNCATED AT 250 WORDS)

Inter- and intrasubject variability of solid and liquid gastric emptying parameters. A scintigraphic study in healthy subjects and diabetic patients

This study was performed to assess: (1) the inter- and intrasubject variability of gastric emptying measurements by a scintigraphic method in 12 healthy subjects and 14 diabetic patients, and (2) the reproducibility of diagnosis of either the presence or absence of gastroparesis. To address this issue, radiolabeled solid-liquid meals were ingested by all subjects on two separate days. High intersubject variability of gastric emptying measurements was shown in both populations. Intrasubject variability was higher in diabetic patients than in healthy subjects. However, there was no significant difference between the means of any parameters obtained on two separate days. The reproducibility of the diagnosis of gastroparesis was excellent for all parameters; the solid half emptying time was the most reproducible parameter (92% in healthy subjects and 93% in diabetic patients). The means +/- SD of the difference between the two separate days' half emptying time results were -10.6 +/- 41.3 min for solids and -4.8 +/- 36.6 min for liquids and were not statistically different from zero. Only one difference between the half emptying time results on two separate days was not in the 95% confidence interval for both solids and liquids; however, this result came from a diabetic patient with obvious gastroparesis on both days. Thus: (1) in spite of high inter- and intrasubject variability, the scintigraphic method of measuring gastric emptying is highly reproducible for the diagnosis of gastroparesis; (2) reproducibility is better in healthy subjects than in diabetic patients; and (3) the knowledge of intrasubject variability allows assessment of the required sample sizes for pharmacological studies using prokinetic medications.

[Maintenance treatment of Crohn's disease using orally administered mesalazine (Pentasa). A controlled multicenter study. The Study Groups on the Treatment of Inflammatory Digestive Disorders]

BACKGROUND

Mesalamine provides a new therapeutic approach in treating Crohn's disease.

METHODS

To assess the efficacy and safety of slow-release mesalamine (Pentasa) in maintaining remission in Crohn's disease, 161 patients with inactive disease were randomized to receive either Pentasa (2 g/day) or placebo in a 2-year double-blind, multicenter trial. Two strata were defined according to the duration of their remission: < 3 months (n = 64) or 3-24 months (n = 97), presumed to be high and low relapse risk strata, respectively.

RESULTS

The probability of relapse was higher in the short-remission placebo group than in the three other groups (p < 0.003), showing there was a significant benefit from Pentasa in the high relapse risk stratum. In this stratum, the 2-year on-going remission rate was of 29% +/- 9% and 45% +/- 11% (mean +/- SD) in the placebo and Pentasa groups, respectively. The incidences of side effects were similar in both groups.

CONCLUSION

Pentasa (2 g/day for 2 years) is a safe and effective maintenance treatment for Crohn's disease when given within 3 months of achieving remission.

Simultaneous assessment of liquid emptying and proximal gastric tone in humans

BACKGROUND

Barostat is the only technique that allows assessment of gastric tone in humans. Our aim was to simultaneously assess gastric emptying and relaxation in response to a liquid meal.

METHODS

Gastric tone was monitored using an electronic barostat in six healthy subjects after three liquid meals (200 mL, 400 mL, 600 mL, 1 kcal/mL). Scintigraphic imaging was obtained by using double isotopic labeling (technetium 99m for liquid of the 200 mL meal and xenon 133 for air into the barostat).

RESULTS

Profound gastric relaxation was detected in every subject. The duration of proximal gastric relaxation increased with meal size. The proximal stomach remained relaxed through the duration of gastric emptying. Gastric tone returned to the fasting values simultaneously with completion of liquid emptying. Repeated measures after the 200-mL meal showed that amplitude (i.e., maximal volume change) and duration of relaxations were reproducible. However, the presence of the bag slightly accelerated gastric emptying and modified the intragastric distribution of the meal.

CONCLUSIONS

The barostat is a sensitive and reproducible technique to measure gastric relaxation following liquid meals in humans. The results also suggest that the role of gastric tone as the driving force of gastric emptying of liquids has been overestimated.

[Treatment with butyrate/IL-2 combination in peritoneal carcinomatosis of colonic origin]

Two therapeutic assays associating sodium butyrate (NaB) and interleukin-2 (IL-2) were applied on rats after intraperitoneal (i.p.) injection of colon carcinoma cells. The first assay began at day 1 after cell injection, and the second one at day 10 after injection, i.e. when carcinomatosis was established. IL-2 was given i.p. three times per day and NaB one time per day, for five and seven days respectively. The survival median of IL-2 treated rats significantly increased versus those of untreated ones, and was much higher with NaB in supplement. Moreover, using this associative treatment, we observed some cases of complete curacy, even in rats bearing established carcinomatosis.

Structural features of resistant starch at the end of the human small intestine

Structural features of in vivo resistant starch were assessed using the ileal contents of four humans. Two of the latter were collected by ileostomy after ingestion of bean flakes or potato flakes and the other two were collected by an intubation technique after ingestion of retrograded high-amylose maize starch or complexed high-amylose maize starch. The degree of polymerizations (DP), solubility and crystallinity were assessed. For all samples, starch fractions which escaped digestion in the small intestine were composed of three populations of alpha-glucans with proportions differing according to the substrate. Small quantities of oligosaccharides made up the first population, illustrating a limitation of absorption in the small intestine. The second population, the main resistant fraction, was comprised of retrograded amylose of mean DPn of about 35 glucose units with a melting temperature at 150 degrees C and exhibiting a B-type pattern. Finally high molecular weight semi-crystalline alpha-glucans were attributed to fragments of starch. This study showed that some potentially digestible starch could reach the colon and crystalline fractions constituted only part of the starch that escaped digestion in the human small intestine.