Biomedical subjects

Juan-R Malagelada

Publications and source records attributed to Juan-R Malagelada.

At least 19 recordsLinked to original sources

PubMed2007

Fecal excretion of deoxyribonucleic acid in long-term follow-up of patients with inactive ulcerative colitis.

BACKGROUND: We have developed a technique for measuring fecal excretion of human DNA by assuming that luminal desquamation of epithelial and inflammatory cells increases in damaged colonic mucosa. However, the clinical usefulness of this technique in the follow-up of patients with ulcerative colitis has not been established. The aim of this study was to determine the stability of fecal DNA in inactive ulcerative colitis and its potential value as an indicator of relapse. METHODS: The 54 patients with clinically quiescent ulcerative colitis in this prospective study were followed for 12 months or until clinical relapse (clinical activity index > 7). Fecal calprotectin concentration was determined by ELISA, and fecal DNA concentration was determined by quantitative PCR. RESULTS: During the year of follow-up, 23 of the 54 patients relapsed, with a median increase in the colitis activity index from 1.0 to 8.0 (P < 0.01). Median fecal DNA remained unchanged in patients with stable, inactive colitis, ranging from 6.8 copies/microg at inclusion to 1.7 copies/microg at the end of follow-up. Fecal calprotectin level also was unchanged, ranging from 414.0 microg/g at inclusion to 128.9 microg/g at the end of follow-up. In contrast, fecal DNA concentration increased significantly in patients who relapsed (259.0 versus 3.9 copies/microg at entry; P < 0.01). Similar increases in relapsing patients were also observed with fecal calprotectin. ROC curve analysis to assess the accuracy of fecal DNA and calprotectin in detecting relapses during follow-up yielded similar results. CONCLUSIONS: Fecal DNA concentration remained stable in patients with inactive ulcerative colitis but increased significantly with relapses. Determining fecal DNA concentration may be a new objective instrument to use in the follow-up of patients.

Adult↗

PubMed2006

Physical activity and intestinal gas clearance in patients with bloating.

BACKGROUND: Patients complaining of abdominal bloating have impaired tolerance and clearance of intestinal gas loads. Mild exercise enhances intestinal clearance and prevents retention of intestinal gas loads in healthy subjects. Our aim was to evaluate the putative beneficial effects of physical activity in patients with abdominal bloating. METHODS: In eight patients complaining of bloating, seven with irritable bowel syndrome, and one with functional bloating, according to Rome II criteria, a gas mixture was continuously infused (12 mL/min) into the jejunum for 120 min with simultaneous duodenal lipid perfusion (1 kcal/min). Gas evacuation, perception (0-6 scale), and abdominal girth were measured at 15-min intervals. Paired studies were randomly performed in the supine position during intermittent pedaling (5 min with 3-min rest intervals at 40 rpm and 0.15 kp load) versus rest (as control). RESULTS: During rest, a significant proportion of the gas infused was retained in the gut (45 +/- 9%, P < 0.01 vs basal), but retention was significantly lower during exercise (24 +/- 7%, P < 0.05 vs rest). Gas retention during rest was associated with significant abdominal symptoms (3.6 score; P < 0.01 vs basal), and symptoms also improved during exercise (2.8 score, P < 0.05 vs rest). During the test, patients developed abdominal distension, which was related to the volume of gas retained (r = 0.68, P < 0.05). CONCLUSION: Mild physical activity enhances intestinal gas clearance and reduces symptoms in patients complaining of abdominal bloating.

Adult↗

PubMed2006

Impaired small bowel gas propulsion in patients with bloating during intestinal lipid infusion.

OBJECTIVE: In healthy individuals, intraluminal lipids delay intestinal gas clearance, and this reflex is exaggerated in patients with irritable bowel syndrome (IBS). Our aim was to determine the site of action of abnormal lipid-induced reflexes in IBS. METHODS: In six patients with (IBS) predominantly complaining of bloating and in six healthy subjects, a mixture of gas (N2, O2, and CO2 in venous proportions to minimize diffusion) was infused (12 mL/min) either into the jejunum or into the ileum for 2 h, with simultaneous perfusion of lipids (0.5 kcal/min) into the proximal duodenum. Rectal gas evacuation was measured by a barostat. Abdominal perception (by a 0-6 scale) and girth changes were measured at 15-min intervals. The effects of jejunal versus ileal gas infusion were compared by paired tests in random order on separate days. RESULTS: IBS patients exhibited significant gas retention during infusion of gas into the jejunum (398 +/- 90 mL vs-210 +/- 105 mL in health, p < 0.05) but not during ileal infusion (-79 +/- 87 mL vs-79 +/- 78 mL in health, NS; p < 0.05 vs jejunal infusion). Gas retention during jejunal gas infusion in IBS patients was associated with significant abdominal distension (11 +/- 3 mm girth increment vs 0 +/- 1 mm during ileal gas infusion and 1 +/- 1 mm in health, p < 0.05 for both) and abdominal symptoms (3.6 +/- 0.6 score vs 2.6 +/- 0.7 score during ileal gas infusion and 1.6 +/- 0.5 score in health, p < 0.05 for both). CONCLUSIONS: In IBS patients intraluminal lipids impair intestinal gas clearance because of upregulated reflex inhibition of small bowel transit, without appreciable colonic effects.

Adult↗

PubMed2006

Functional gastroduodenal disorders.

A numerically important group of patients with functional gastrointestinal disorders have chronic symptoms that can be attributed to the gastroduodenal region. Based on the consensus opinion of an international panel of clinical investigators who reviewed the available evidence, a classification of the functional gastroduodenal disorders is proposed. Four categories of functional gastroduodenal disorders are distinguished. The first category, functional dyspepsia, groups patients with symptoms thought to originate from the gastroduodenal region, specifically epigastric pain or burning, postprandial fullness, or early satiation. Based on recent evidence and clinical experience, a subgroup classification is proposed for postprandial distress syndrome (early satiation or postprandial fullness) and epigastric pain syndrome (pain or burning in the epigastrium). The second category, belching disorders, comprises aerophagia (troublesome repetitive belching with observed excessive air swallowing) and unspecified belching (no evidence of excessive air swallowing). The third category, nausea and vomiting disorders, comprises chronic idiopathic nausea (frequent bothersome nausea without vomiting), functional vomiting (recurrent vomiting in the absence of self-induced vomiting, or underlying eating disorders, metabolic disorders, drug intake, or psychiatric or central nervous system disorders), and cyclic vomiting syndrome (stereotypical episodes of vomiting with vomiting-free intervals). The rumination syndrome is a fourth category of functional gastroduodenal disorder characterized by effortless regurgitation of recently ingested food into the mouth followed by rechewing and reswallowing or expulsion. The proposed classification requires further research and careful validation but the criteria should be of value for clinical practice; for epidemiological, pathophysiological, and clinical management studies; and for drug development.

Child↗

PubMed2006

Impaired viscerosomatic reflexes and abdominal-wall dystony associated with bloating.

BACKGROUND & AIMS: Abdominal bloating is a frequent complaint in irritable bowel syndrome (IBS), but its underlying mechanism remains uncertain. Our aim was to determine whether the abdominal wall, specifically its adaptation to intra-abdominal volumes, plays a role. METHODS: In 12 patients complaining of abdominal bloating (8 IBS and 4 functional bloating) and in 12 healthy controls, the effect of colonic gas load (24 mL/min rectal gas infusion for 1 hour) on perception (measured by a 0-6 scale), abdominal girth, and muscular activity was tested. With the participants sitting on an ergonomic chair and the trunk erect, multichannel electromyography was measured via bipolar surface electrodes located over the upper and lower rectus abdominis, and the external and internal oblique bilaterally. RESULTS: In healthy controls, colonic gas loads produced subjective symptoms (score, 3.0 +/- 0.3), objective abdominal distention (girth increment, 6 +/- 1 mm), and increased the activity of the abdominal muscles (external oblique activity, 11% +/- 3% in; P < .05 vs basal). At the same infused gas volumes, the patients developed significantly more symptoms (score, 4.5 +/- 0.4) and abdominal distention (11 +/- 1 mm; P < .05 vs healthy for both). These abnormal responses were associated with failed tonic contraction of the abdominal wall (external oblique activity change, -1% +/- 4%; P value not significant vs basal) and paradoxic relaxation of the internal oblique (activity reduction, 26% +/- 7%; P < .01 vs basal). CONCLUSIONS: In patients with bloating, abdominal perception and distention in response to intra-abdominal volume increments are exaggerated markedly and associated with muscular dystony of the abdominal wall.

Abdominal Muscles↗

PubMed2006

Modulation of apoptosis in intestinal lymphocytes by a probiotic bacteria in Crohn's disease.

Apoptosis of active T lymphocytes constitutes a major control mechanism of immune homeostasis and tolerance. In Crohn's disease, abnormal activation of mucosal T lymphocytes against enteric bacteria is the key event triggering intestinal inflammation. Resistance of lymphocytes to apoptosis has been proposed as the pathogenetic defect. We examined the influence of bacteria-mucosa interactions on apoptosis of mucosal T lymphocytes. Ileal specimens were obtained at surgery from 12 patients with Crohn's disease. Mucosal explants from each specimen were cultured with nonpathogenic Escherichia coli ATCC 35345, Lactobacillus casei DN-114 001, or no bacteria. Cytokine release was measured in supernatant, and mononuclear cells were isolated for phenotypic characterization and Bcl-2 family protein expression. Coculture of inflamed tissue with L. casei significantly reduced the release of interleukin (IL)-6 and tumor necrosis factor alpha (P < 0.05). In addition, coculture with L. casei significantly reduced the number of T cells displaying the IL-2 receptor in the lamina propria. Expression of the antiapoptotic protein Bcl-2 in lamina propria lymphocytes was also reduced after coculture with L. casei, and the percentage of deoxyuridine triphosphate nick-end labeling positive lymphocytes increased. The nonpathogenic E. coli strain had no significant effect. In conclusion, L. casei reduces the number of activated T lymphocytes in the lamina propria of Crohn's disease mucosa. A balanced, local microecology may restore immune homeostasis.

Adult↗

PubMed2005

Modulation of gastric accommodation by duodenal nutrients.

AIM: To determine the relative potency and contribution of intestinal nutrients to net gastric accommodative relaxation and conscious perception. METHODS: In 12 healthy subjects, we randomly tested duodenal loads of lipids and carbohydrates (12 mL administered in 4 min) at various caloric concentrations (0.0125-0.8 kcal/mL) separated by 12-24 min wash-out periods of saline infusion. Maximal gastric relaxation was induced at the end of each experiment by i.v glucagon (5 microg/kg), as reference. The reflex gastric response was measured by a barostat, and symptom perception by a 0-6 score questionnaire. RESULTS: Lipids induced a dose-response gastric relaxation with a steep and early rise. Maximal effect (179+/-42 mL relaxation) reached at a relatively low concentration (0.2 kcal/mL), maximal lipid-induced relaxation was 61+/-6% of the glucagon effect. By contrast, duodenal infusion of carbohydrates induced weaker relaxation that became significant only at the high end of the physiological concentration range (65+/-14 mL with 0.8 kcal/mL). Intestinal nutrient loads, either of lipid or carbohydrates, did not induce significant changes in perception (0.6+/-0.4 and 0.1+/-0.4 score increase for the highest concentrations, respectively). CONCLUSION: Chyme entering the small bowel induces nutrient-specific gastric relaxatory reflexes by a physiologically saturable mechanism. Normally, neither the intestinal nutrient load nor the gastric accommodative response is perceived.

Adult↗

PubMed2005

Origin of gas retention and symptoms in patients with bloating.

BACKGROUND & AIMS: Patients reporting abdominal bloating exhibit impaired tolerance to intestinal gas loads. The aim of this study was to identify the gut compartment responsible for gas retention. METHODS: In 30 patients predominantly reporting abdominal bloating (24 with irritable bowel syndrome and 6 with functional bloating) and 22 healthy subjects, gas (nitrogen, carbon dioxide, and oxygen) was infused into the intestine for 2 hours while measuring rectal gas outflow. First, in 12 patients and 10 healthy subjects, gas transit (24 mL/min jejunal infusion labeled with 74 MBq bolus of 133 Xe) was measured by scintigraphy. Second, in groups of patients and healthy subjects, the effects of gas infusion (12 mL/min) in the jejunum versus ileum, jejunum versus cecum, and jejunum versus sham infusion (n=6 each) were compared by paired tests. RESULTS: In patients, total gut transit of gas was delayed (50% clearance time, 33 +/- 4 min vs 23 +/- 4 min in healthy subjects; P <.05) owing to impaired small bowel transit (50% clearance time, 20 +/- 2 min vs 12 +/- 3 min in healthy subjects; P <.05), whereas colonic transit was normal (50% clearance time, 13 +/- 2 min vs 11 +/- 2 min in healthy subjects; not significant). Furthermore, jejunal gas infusion in patients was associated with gas retention (329 +/- 81 mL vs 88 +/- 79 mL in healthy subjects; P <.05), whereas direct ileal or colonic infusion was not (61 +/- 103 mL and -143 +/- 87 mL retention, respectively). CONCLUSIONS: In patients reporting bloating, the small bowel is the gut region responsible for ineffective gas propulsion.

Adult↗

PubMed2005

Abdominal bloating.

Abdominal bloating is a common and significant clinical problem that remains to be scientifically addressed. Bloating is one of the most bothersome complaints in patients with various functional gut disorders. However, in the current standard classification, abdominal bloating is merely regarded as a secondary descriptor, which masks its real clinical effect. Four factors are involved in the pathophysiology of bloating: a subjective sensation of abdominal bloating, objective abdominal distention, volume of intra-abdominal contents, and muscular activity of the abdominal wall. The primer to elicit subjective bloating may be any of the other 3 factors, or the sensation may be related to distorted perception. All of these mechanisms may play an independent role or may be interrelated. Gas transit studies have evidenced that patients with bloating have impaired reflex control of gut handling of contents. Segmental pooling, either of gas or of solid/liquid components, may induce a bloating sensation, particularly in patients with altered gut perception. Furthermore, altered viscerosomatic reflexes may contribute to abdominal wall protrusion and objective distention, even without major intra-abdominal volume increment. Bloating probably is a heterogeneous condition produced by a combination of pathophysiological mechanisms that differ among individual patients and that in most cases are subtle and undetectable by conventional methods. Further advances in the pathophysiology and clinical forms of bloating are warranted to develop mechanistic strategies rather than the current empiric treatment strategies for comprehensive and effective management of this problem.

Abdomen↗

PubMed2005

Responses of anal constipation to biofeedback treatment.

OBJECTIVE: Biofeedback is considered an effective treatment for anal constipation, but a substantial proportion of patients fail to improve. Our aim was to identify the key predictors of outcome using a comprehensive standardized evaluation of anorectal function. MATERIAL AND METHODS: We retrospectively analysed the clinical and physiological data of 148 patients consecutively treated for constipation due to functional outlet obstruction by biofeedback. Clinical evaluation was performed by means of a structured questionnaire. Anorectal evaluation included anal pressure, neural reflexes, defecatory dynamics, rectal compliance, rectal sensitivity and balloon expulsion test. Biofeedback treatment was performed using a manometric technique. The clinical response to biofeedback treatment was evaluated as good (improvement of constipation) or poor (no improvement or worsening). RESULTS: Of the 148 patients included, 112 (86 F, 26 M; age range 8-67 years) were followed-up for between 1 and 44 months, and 66% had a good response to treatment. The response depended on the severity of the defecatory dysfunction. Thus, lack of anal relaxation during straining and inability to evacuate a 1 ml intrarectal balloon were inversely related to physiological variables related to therapeutic success. Among the 49 patients with absent anal relaxation, 51% had a good response to treatment (versus 78% in patients with partial relaxation; p < 0.01), and among the 29 patients with failed balloon expulsion, 48% responded to treatment (versus 74% in patients able to evacuate > or = 1 ml intrarectal balloon; p < 0.05). CONCLUSIONS: Even in the presence of negative predictors, biofeedback is a valuable treatment option in a substantial proportion of constipated patients.

Adolescent↗

PubMed2005

Melatonin as a modulator of the ileal brake mechanism.

OBJECTIVE: The gastrointestinal tract represents the most important extrapineal source of melatonin. Intestinal melatonin release is induced by the ileal passage of nutrients and could play a part in the control of postprandial gut motility. The specific aim of this study was to determine the putative role of melatonin in the "ileal brake" reflex, an important mechanism released by ileal lipids that regulates the gastric emptying of chyme. MATERIAL AND METHODS: Under general anaesthesia rats were fitted with ileal cannula exteriorized at the back of the neck. After a 1-week recovery, experiments were performed in conscious fasted animals. Rats were fed by gavage 1.5 ml casein hydrolyse plus 0.05% phenol red and either saline or Intralipid were continuously infused (2 ml/h) into the ileum. Gastric emptying was measured 50 min after ingestion by gastric lavage and determination of phenol red by spectrophotometry. The effects of melatonin (1 mg/kg) and melatonin antagonist S-22153 (dose-response study 0.2-25 mg/kg) were tested versus vehicle in paired experiments at 1-week intervals. RESULTS: Ileal infusion of lipids delayed gastric emptying. During ileal infusion of lipids, melatonin antagonist S-22153, but not melatonin, potentiated the delay in gastric emptying induced by the ileal brake mechanism. The inhibition of gastric emptying induced by S-22153 was dose related. Neither melatonin nor S-22153 had noticeable effects on gastric emptying during ileal infusion of saline. CONCLUSIONS: Our data suggest that melatonin, released in response to ileal lipids, exerts a modulatory influence that decreases the inhibitory effects of the ileal brake on gastric emptying of nutrients.

Animals↗

PubMed2004

Effects of physical activity on intestinal gas transit and evacuation in healthy subjects.

PURPOSE: To determine the effects of mild physical activity on intestinal gas transit and clearance. METHODS: In 8 healthy adults, a gas mixture was infused continuously into the jejunum (12 mL/min) for 120 minutes with simultaneous duodenal lipid perfusion (1 kcal/min). Gas evacuation, perception of abdominal sensations (on a scale of 0 [none] to 6 [pain]), and abdominal girth were measured at 15-minute intervals during rest and intermittent pedalling, with subjects in a supine position. RESULTS: Mean (+/- SD) intestinal gas retention was lower during exercise than at rest (-84 +/- 303 mL vs. 143 +/- 219 mL, P <0.05). Gas retention during rest was associated with significant abdominal distension (8 +/- 6 mm, P <0.01 vs. basal), which was decreased with exercise (3 +/- 7 mm, P <0.05 vs. rest). The gas challenge test was well tolerated both during exercise and rest (perception score: 0.6 +/- 0.5 vs. 0.9 +/- 0.4, P = 0.25). CONCLUSION: In healthy subjects, gut transit of intraluminal gas is enhanced by mild physical activity.

Adult↗

PubMed2004

Vitamin E attenuates biochemical and morphological features associated with development of chronic pancreatitis.

The objective was to investigate the effects of vitamin E on collagen deposition induced by Cyclosporin A (CsA) administration in rats with caerulein (Cr) pancreatitis. CsA transforms the fully regenerative, self-limited form of Cr pancreatitis into a chroniclike disease in conjunction with increased transforming growth factor (TGF)-beta and myofibroblast proliferation. Vitamin E inhibits TGF-beta release in mesangial cells and reduces CsA cytotoxicity. Wistar rats received CsA daily (20 mg/kg), and CR pancreatitis was induced on days 1 and 8 (Cr + CsA group). In a separate group, vitamin E (600 mg.kg(-1).day(-1)) was administered starting 4 days before CsA. Three other groups received either vehicle, CsA, or Cr alone. Thiobarbituric acid-reactive substance (TBARS), 8-isoprostanes, and hyaluronic acid were measured in plasma obtained on the day the animals were killed (day 15). Pancreases were weighed and processed for light microscopy to assess connective tissue and myofibroblast number. Pancreatic homogenates were also assayed for collagen (hydroxyproline) and TBARS content. TBARS, 8-isoprostane, and TGF-beta were elevated in CsA and Cr + CsA rats. Vitamin E treatment greatly decreased these parameters. Vitamin E also decreased the fall in pancreatic weight observed in Cr + CsA pancreas. Pancreatic hydroxyproline and plasma hyaluronic acid were increased in Cr + CsA rats but were effectively reduced by vitamin E. Morphology showed improvement in fibrosis score and a decreased number of myofibroblasts in vitamin E-treated rats. Vitamin E reduces oxidative stress and collagen deposition during the development of experimental chronic pancreatitis. Adjuvant antioxidants may be of value in the treatment of chronic pancreatitis.

Animals↗

PubMed2003

Reflex control of intestinal gas dynamics and tolerance in humans.

Intestinal transit of gas is normally adapted to the luminal gas load, but in some patients impaired transit may lead to gas retention and symptoms. We hypothesized that intestinal gas transit is regulated by reflex mechanisms released by segmental distension at various gut levels. In 24 healthy subjects, we measured gas evacuation and perception of jejunal gas infusion (12 ml/min) during simultaneous infusion of duodenal lipids mimicking the postprandial caloric load (Intralipid, 1 kcal/min). We evaluated the effects of proximal (duodenal) distension (n = 8), distal (rectal) distension (n = 8), and sham distension, as control (n = 8). Duodenal lipid infusion produced gas retention (366 +/- 106 ml) with low abdominal perception (1.5 +/- 0.8 score). Distension of either the duodenum or rectum during lipid infusion expedited gas transit and prevented retention (-120 +/- 164 and -124 +/- 162 ml retention, respectively; P < 0.05 vs. control). However, the tolerance to the intestinal gas load differed markedly, depending on the site of distension; perception remained low during rectal distension (2.6 +/- 0.7 score; not significant vs. control) but increased during duodenal distension (4.4 +/- 0.7 score; P < 0.05 vs. control). We conclude that focal gut distension, either at proximal or distal sites, accelerates gas transit, but the symptomatic response depends on the site of stimulation.

Abdomen↗

PubMed2003

Gut flora in health and disease.

The human gut is the natural habitat for a large and dynamic bacterial community, but a substantial part of these bacterial populations are still to be described. However, the relevance and effect of resident bacteria on a host's physiology and pathology has been well documented. Major functions of the gut microflora include metabolic activities that result in salvage of energy and absorbable nutrients, important trophic effects on intestinal epithelia and on immune structure and function, and protection of the colonised host against invasion by alien microbes. Gut flora might also be an essential factor in certain pathological disorders, including multisystem organ failure, colon cancer, and inflammatory bowel diseases. Nevertheless, bacteria are also useful in promotion of human health. Probiotics and prebiotics are known to have a role in prevention or treatment of some diseases.

Bacteria, Aerobic↗

PubMed2003

Predictors of response to biofeedback treatment in anal incontinence.

PURPOSE: Biofeedback is considered an effective treatment for anal incontinence, but a substantial proportion of patients fails to improve. The purpose of this study was to identify the key predictors of outcome. METHODS: We retrospectively analyzed the clinical and physiologic data of 145 patients consecutively treated in our unit for anal incontinence by biofeedback. Clinical evaluation was performed by means of a structured questionnaire that included previous history, symptoms of incontinence, and bowel habit. Anorectal evaluation measured anal pressure profiles, neural reflexes, defecatory dynamics, rectal compliance, and rectal sensitivity. Biofeedback treatment was performed by a manometric technique with reinforcement sessions scheduled every three months and daily exercising at home. Six months after the onset of biofeedback treatment the clinical response was evaluated as good (improvement of incontinence) or poor (no improvement or worsening). RESULTS: Of 126 patients (104 female; age range, 17-82 years) with at least six-month follow-up, 84 percent had a good response to treatment. By univariate analysis, several factors, such as age, history of constipation, abnormal defecatory maneuver, and rectal compliance, were significantly related to treatment response, but by multivariate logistic regression only age and defecatory maneuver were independent predictors of the response. The association of both factors provided the best sensitivity and specificity; 48 percent of patients younger than age 55 years and with abnormal defecatory maneuver had negative response to treatment, whereas 96 percent of patients age 55 years or older with normal defecatory maneuver had a positive response. CONCLUSION: In patients with anal incontinence scheduled for biofeedback treatment, potential alterations of defecation should be first searched for and corrected, particularly in younger patients.

Adolescent↗

PubMed2003

Antro-fundic dysfunctions in functional dyspepsia.

BACKGROUND & AIMS: Symptoms in functional dyspepsia have been related to impaired accommodation and hypersensitivity of the proximal stomach. We hypothesized that identification of putative antral dysfunctions provides a more comprehensive pathophysiological interpretation. METHODS: In 30 patients with functional dyspepsia and 22 healthy subjects, 2 consecutive studies were performed. In study I, with the subjects in the upright position, the proximal and distal stomach were selectively distended by bags containing air and water, respectively, while perception and fundic relaxation in response to antral distention were measured. In study II, by using air-filled bags connected to a tensostat, the proximal and the distal stomach were selectively distended by positioning the subjects on the right and left lateral decubitus, respectively, while perception, compliance, and the responses to intestinal nutrient infusion were measured. RESULTS: Patients with dyspepsia showed hypersensitivity of both the proximal stomach (discomfort at 30 +/- 3 g vs. 62 +/- 2 g in controls; P < 0.05) and the antrum (discomfort at 31 +/- 2 g vs. 53 +/- 4 g in controls; P < 0.05). Fundic and antral fasting tone was normal, but reflex fundic relaxation induced either by antral distention (3 +/- 16 mL at 80 mL of distention vs. 38 +/- 10 mL in controls; P < 0.05) or by intestinal nutrients (35 +/- 7 mL vs. 107 +/- 8 mL in controls; P < 0.05) was markedly impaired. CONCLUSIONS: Antral and fundic dysfunctions interact to produce the symptoms of functional dyspepsia, and impaired control of fundic accommodation may lead to overload of a hypersensitive antrum.

Adult↗

PubMed2003

Role of bacteria in experimental colitis.

Epidemiology suggests some relationship between the establishment of the gut flora and the risk of developing inflammatory bowel disease. Unrestrained activation of the immune system against commensal bacteria appears to be responsible for the chronicity of these diseases. In animal models, broad-spectrum antibiotics reduce the bacterial load and militate against intestinal inflammation. Several bacterial species found in of the common microflora, including anaerobes, are able to invade the colonic wall when there is dysfunction of the colonic mucosal barrier. Most aerobes provoke focal areas of acute inflammation, but some anaerobes in the predominant flora induce diffuse a fibrogenic transmural response. Current research aims to identify the probiotics that might act against these bacteria. Colonization with specific probiotic strains, including a bacterium genetically engineered to secrete interleukin-10, prevents spontaneous colitis in susceptible mice. Certain lactobacilli exhibit anti-inflammatory properties naturally, i.e. without previous genetic manipulation. Prebiotics may increase colonization by lactobacilli and can prevent mucosal inflammation. Modulation of the gut flora with probiotics may prove useful in the prevention and control of inflammatory bowel diseases.

Animals↗