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Biomedical subjects

Mickael Bouin

Publications and source records attributed to Mickael Bouin.

14 recordsLinked to original sources
PubMed2006

Effects of intragastric L-arginine administration on proximal stomach tone under basal conditions and after an intragastric diet.

Nitric oxide (NO) plays an important role as a nonadrenergic, noncholinergic inhibitory neurotransmitter in the GI tract. Our study aims were to investigate the effect of a single intragastric L-arginine (L-Arg) administration, as a source of NO, on proximal stomach tone in basal and postintragastric administration of a polymeric diet in humans and to evaluate concomitantly the effect on antral area as an indirect assessment of gastric emptying. Eight healthy volunteers were studied in a randomized double-blind crossover study after, respectively, 15 g L-Arg, 30 g L-Arg, or placebo administered in the stomach through a gastric tube. The drug administration was followed by a polymeric diet infusion (500 ml/500 kcal) at a rate of 250 ml/hr. Gastric tone variations were recorded with an electronic barostat, gastric emptying was concomitantly estimated by repeated ultrasound measurements of antral area, and symptoms were recorded throughout the experiment.L-Arg administration was associated with significantly higher increases in barostat bag volumes at both dosages, 30 g (117+/-16 ml) and 15 g (67+/-15 ml), compared to placebo (46+/-11 ml; P < 0.05). In response to the polymeric diet the 30-g L-Arg challenge was associated with a smaller increase in intrabag volume, whereas postinfusion final volumes did not differ in the three treatment conditions. Antral areas were not different at any time of measurement among the three challenges. Bloating and diarrhea were observed after 30-g L-Arg administration in five subjects of eight. Short-term L-Arg administration was able to induce proximal stomach relaxation that allowed a secondary response to enteral feeding only at the 15-g dosage. This 15-g dosage was as well tolerated as the placebo and was associated with no significant changes in gastric emptying patterns.

Adult↗
PubMed2006

Concomitant variations of gastric tone and duodenal motility in humans: results of a placebo-controlled study assessing octreotide and sumatriptan.

OBJECTIVE: To describe the concomitant effects of octreotide and sumatriptan on fundic tone and duodenal phase III activity. MATERIAL AND METHODS: A double-blind study was performed in nine volunteers, studied for 2 h after receiving 50 microg octreotide, 6 mg sumatriptan or placebo. Fundic tone variations were assessed by barostat while antroduodenal motility was studied concomitantly using manometry. RESULTS: A rapid increase in intrabag volume was observed in all but one subject after both sumatriptan and octreotide administration, while only two subjects exhibited a volume variation after placebo, p<0.01. A significant decrease in the number of phasic contractions was observed after octreotide, while sumatriptan reduced only wave amplitudes (p<0.05). A total of 13 concomitant duodenal phase III-like activities were observed in the duodenum after octreotide, 3 after sumatriptan and 4 after placebo, all followed by spontaneous fundic relaxation with disappearance of phasic contractions, p<0.05. Spontaneous phase III activities were different from phases III-like activities after octreotide in velocity and duration (p<0.05). CONCLUSIONS: Octreotide induced concomitant fundic relaxation, disappearance of phasic contractions and duodenal phase III-like activity. Sumatriptan relaxed the proximal stomach and reduced the amplitude of fundic phasic contractions without affecting concomitant antroduodenal phase III activity.

Adult↗
PubMed2006

Tolerance to gastric distension in patients with functional dyspepsia: modulation by a cholinergic and nitrergic method.

BACKGROUND: In patients with functional dyspepsia (FD), tolerance to gastric fundus distension is frequently compromised. We tested the contribution of contractile cholinergic or relaxing nitrergic pathways in this disorder. METHODS: Thirty-nine patients (29 women, 10 men) with FD participated in this study. Gastric distension studies where carried out by inflating a fundic balloon until the maximum distension volume (MDV) tolerated by the patient. Gastric distension was first evaluated in basal control conditions before repeating the test after the injection of anticholinergic hyoscine (Buscopan 20 mg intravenous) or following the administration of nitric oxide donor nitroglycerin (Nitrolingual 1.2 mg sublingual). RESULTS: MDVs were significantly (P<0.01) lower in FD patients (495+/-27 ml) than in controls (995+/-59 ml). Intolerance to fundic distension was found in 77% of dyspepsia patients. Hyoscine improved the threshold for discomfort (343+/-21 versus 421+/-43 ml; P<0.05), as well as the MDV (510+/-36 versus 635+/-44 ml; P<0.01). This drug effect was seen in 71% (10/14) of patients. Nitroglycerin failed to modify thresholds. However, improved tolerance was seen in 15% (2/13) of the patients. CONCLUSION: Intolerance to fundic distension is a frequent finding in FD (77% patients). The cholinergic pathway seems to be a predominant factor involved in tolerance to distension in patients with FD. Fundus-relaxing drugs should be considered for the treatment of dyspepsia.

Adult↗
PubMed2005

Gastric tone variations during gastric infusion of fiber-supplemented formulas.

BACKGROUND AND AIM: Despite gastric feeding being a common method of artificial nutritional support, little is known about the effects of enteral nutrition on fundic motor function. The objective of this study was to assess variations of fundic tone and their relation to antroduodenal motility before, during and after nasogastric feeding supplemented or not with fibers. METHOD: Double-blinded studies were performed in random order with the three different diets (2100 kJ) in eight volunteers: fiber free (FF), insoluble fiber (IF) or mixed fiber (MF). Fundic tone was recorded by barostat concomitantly with antroduodenal manometry. RESULTS: Before the infusion, seven spontaneous fundic relaxations occurred during the 24 studies. Concomitantly or less than 2 min before these relaxations, phase III of the migrating motor complex (MMC) with a duodenal onset was recorded. Only the 17 studies without spontaneous fundic relaxation (4 FF, 6 MF, 7 IF) were suitable for the assessment of fundic response to infusion. Disappearance of the volume waves at the beginning and during the whole infusion was observed in 11/17 studies (FF 50%, MF 66% and IF 71%, NS), but a proximal gastric relaxation following the beginning of the infusion occurred in only three individuals, one with the FF and two with IF. When it occurred, fundic relaxation was observed within 2 min and was not different from those observed spontaneously. CONCLUSION: Gastric infusion of a polymeric diet, supplemented or not with fiber, did not promote fundic relaxation in most of the cases but often induced a disappearance of gastric volume waves.

Adult↗
PubMed2004

Changing practices for diagnosis and treatment of colorectal cancer in Calvados: 1990-1999.

AIM: Two consensus conferences on management of colorectal cancer were conducted in France during the last ten Years: one regarding rectal cancers in 1994 and the other regarding colonic cancer in 1998. In the present study, we examined data collected in a local gastrointestinal cancer registry to investigate changes in management practices for colorectal cancer in a well-defined population seen between 1990 and 1999. METHODS: The study population consisted of 3 135 patients with colorectal cancer diagnosed in Calvados (an administrative district in northern France) from 1990 to 1999. Two periods were defined: P1=1990-1994 and P2=1995-1999. Multivariate logistic regression analysis was performed. RESULTS: No trends in stage of disease at diagnosis or rate of surgical resection were observed. For patients with cancer of the rectum, the rate of sphincter preservation increased significantly from 65.6% in P1 to 72.3% in P2, in men and in all patients under the age of 75 Years. For patients with cancer of the colon, the number of resection specimens with at least eight examined lymph nodes increased from 50.7% in P1 to 60.2% in P2. This trend predominated in university centers; for rectal cancer patients it was significant only in university centers. Prescription of adjuvant chemotherapy for stage III colonic cancer increased significantly: 41.4% in P1 and 52.5% in P2. No changes in prescription of adjuvant radiotherapy for rectal cancer were observed, irrespective of the stage at diagnosis. The proportion of patients managed in university centers decreased significantly over time from 30.5% in P1 to 27.6% in P2, with a corresponding increase in private clinics. CONCLUSION: Most of the trends observed during the study period began before the consensus conference guidelines were Issued. The consensus guidelines appear to have influenced management practices mainly in university centers, while the majority of patients are managed in non-university centers.

Age Factors↗
PubMed2004

Increased oro-cecal transit time in grade I or II hepatic encephalopathy.

UNLABELLED: The pathogenic mechanisms of hepatic encephalopathy remain to be elucidated. It has been suggested that a digestive motor disorder could promote the absorption of toxins produced within the lumen and thus enhance hepatic encephalopathy. AIM: To evaluate oro-cecal transit time in cirrhotic patients with and without hepatic encephalopathy. METHODS: Hospitalized patients with alcoholic cirrhosis without encephalopathy and with spontaneous grade I and II encephalopathy were included. Severity of hepatic encephalopathy was assessed clinically and the Child-Pugh score was used to describe cirrhosis severity. Nine healthy volunteers constituted a control group. Oro-cecal transit time was measured with the sulfasalazine test. RESULTS: Twenty-eight patients (mean age 62.5 +/- 8.5 years) were included. Ten had hepatic encephalopathy of unknown cause and 18 were free of hepatic encephalopathy. Oro-cecal transit time was significantly longer in patients with hepatic encephalopathy (641 +/- 350 min) compared to patients without hepatic encephalopathy (298 +/- 96; P<0.05) and to controls (354 +/- 90; P<0.05). Oro-cecal transit time was comparable for each Child-Pugh score and was not different between the two grades of hepatic encephalopathy. CONCLUSION: Oro-cecal transit time is longer in alcoholic cirrhosis patients with hepatic encephalopathy. This digestive motor disorder provides a partial explanation of hepatic encephalopathy of unknown etiology.

Case-Control Studies↗
PubMed2003

Cardiac sources of embolism should be routinely screened in ischemic colitis.

OBJECTIVE: Potential cardiac sources of embolism may promote ischemic colitis. The aim of this study was to evaluate their role in segmental, nongangrenous ischemic colitis and to determine the usefulness of routine cardiac evaluation in patients with this disease. METHODS: Sixty case and 60 control patients matched for age and gender were included and questioned regarding treatment and prior cardiovascular history or risk factors. Potential cardiac sources of embolism, classified as "proven" or " still debated," were screened using an electrocardiogram, rhythmic Holter monitoring over 24 h, and transthoracic echocardiography. RESULTS: Sex ratio (male:female) was 1:2, and mean age was 70 +/- 14 yr. Case and control patients had similar drug use, prior cardiovascular history, and risk factors. A potential cardiac source of embolism was found in 26/60 case (43%), compared with 14/60 control patients (23%) (p = 0.02; OR = 2.5, 95% CI = 1.2-5.5). Excluding the "still debated," 21/60 case (35%), compared with 8/60 control patients (13%), had a "proven" cardiac source of embolism (p < 0.01; OR = 3.5, 95% CI = 1.4-8.4). Electrocardiogram alone misdiagnosed 72% of the "proven" cardiac sources of embolism, whereas the combination electrocardiogram plus Holter monitoring detected 71%, and electrocardiogram plus echocardiography 62%. Twelve of 21 case patients with at least one proven cardiac source of embolism, were previously unknown. Anticoagulant therapy was required in 32% of case patients and antiarrhythmic therapy in 25% of cases. CONCLUSIONS: Potential cardiac sources of embolism were more common in patients with segmental, nongangrenous ischemic colitis than in control patients. Therefore, these patients should undergo a routine electrocardiogram, rhythmic Holter monitoring, and transthoracic echocardiography. Anticoagulant therapy should also be considered for this patient population.

Aged↗
PubMed2003

[Aorto-digestive fistula and aortic prosthesis. Report of four cases].

The diagnosis of gastrointestinal bleeding secondary to aortoduodenal fistula and the decision to proceed to an early diagnostic and/or therapeutic laparotomy are often difficult in practice. We report 4 cases of patients with aortic prostheses who were hospitalized for gastrointestinal bleeding secondary to aortoduodenal fistula. All of them presented initially with lightheadedness before evidence of GI bleeding. Emergency esophagogastroduodenoscopy performed for 3 patients was normal for 2 of them and showed an ulcer with a stitch at its center in the third duodenum for the other. Abdominal CT scan performed for all the patients confirmed the diagnosis for only one case. Of the 3 patients with a normal CT scan, 2 underwent angiography which provided the diagnosis of aortoenteric fistula successfully treated by embolization. The other angiogram was normal. Surgery was required to establish the diagnosis in one patient and diagnosis was post mortem for the last one.

Aged↗
PubMed2002

Group counseling psychotherapy for patients with functional gastrointestinal disorders: development of new measures for symptom severity and quality of life.

Functional gastrointestinal disorders (FGID) can benefit from various psychological interventions. The main objective here was to define the contribution of a new psychotherapeutic intervention, group counseling psychotherapy, for the management of FGID patients. Secondary aims included validation of new measures for gastrointestinal symptoms and quality of life in patients with FGID. Fifty patients seen in a tertiary care center were included in a program of 10 weekly sessions of 2 hr each. Gastrointestinal symptoms, quality of life, and psychological conditions were measured before and after treatment by quantitative indices and by qualitative self-analysis. Gastrointestinal index and quality-of-life index were significantly (P < 0.02) improved at the end of the psychotherapeutic intervention (from 77.5 +/- 4.0 to 63.2 +/- 4.3 and from 67.7 +/- 3.9 to 54.9 +/- 3.9, respectively). In a control group of patients observed for a comparable period of time while waiting for the psychotherapy program, gastrointestinal and quality of life indices remained unchanged. The severity of gastrointestinal symptoms and the quality of life deterioration were highly correlated factors (r = 0.8) at entry into the trial, and their improvement with psychotherapy was also correlated (r = 0.6; P < 0.001). Psychological abnormalities were frequent in these patients (anxiety in 31%, somatization in 29%, depression in 26% of the patients). However, no specific disorder could predict the results of the psychotherapeutic intervention. Over the long term (6-24 months after conclusion of treatment), gastrointestinal status, quality of life, and psychological condition were estimated as improved by 53%, 63%, and 67% of the patients, respectively. The gastrointestinal index and quality of life index we developed were validated to detect the disease and to follow its evolution in response to treatment. In conclusion, group counseling psychotherapy offered a significant contribution for the management, improving gastrointestinal symptoms and quality of life, of FGID patients. New measures for symptom severity and quality of life are available.

Adult↗
PubMed2002

Rectal distention testing in patients with irritable bowel syndrome: sensitivity, specificity, and predictive values of pain sensory thresholds.

BACKGROUND & AIMS: Visceral hypersensitivity was detected in patients with functional gastrointestinal disorders and has been proposed as a biological marker of irritable bowel syndrome (IBS). The purpose of this study was to assess the sensitivity, specificity, and the predictive values of pain thresholds evaluated by rectal distention using an electronic barostat in patients with or without IBS and in control subjects. METHODS: Patients were diagnosed according to Rome II criteria. Rectal sensory thresholds were determined in 164 patients (86 IBS patients, 26 painless constipation, 21 functional dyspepsia, and 31 miscellaneous conditions) and in 25 normal controls. All subjects underwent a series of rectal isobaric distentions using an electronic barostat. The bag was progressively distended from 0 to 48 mm Hg and, in response to distention, subjects reported on discomfort or pain. RESULTS: Pain thresholds were lower in IBS patients (30.4 +/- 6.7 mm Hg) compared with controls (44.5 +/- 5), painless constipated (45.4 +/- 5.3), functional dyspepsia (39.4 +/- 7.8), and miscellaneous patients (43.2 +/- 5.5). At the level of 40 mm Hg, the sensitivity of the rectal barostat to identify IBS patients from normal subjects and non-IBS patients was 95.5% and its specificity was 71.8%. The positive predictive value was 85.4%. The negative predictive value was 90.2%. CONCLUSIONS: Lowered rectal pain threshold is a hallmark of IBS patients. Rectal barostat testing is useful to confirm the diagnosis of IBS and to discriminate IBS from other causes of abdominal pain.

Adult↗
PubMedDate not supplied

Effects of enteral feeding on antroduodenal motility in healthy volunteers with 2 different fiber-supplemented diets: a 24-hour manometric study.

BACKGROUND: Antroduodenal motility during enteral nutrition remains poorly understood. The aim of the study was to evaluate antroduodenal motor activity during intermittent intragastric feeding and between enteral solutions supplemented with new recommended soluble or standard insoluble fibers. METHODS: Two 24-hour antroduodenal manometric studies were performed with a interval of 1 week in 8 healthy volunteers. Two similar enteral diets except for fiber (soluble vs insoluble) were separately assessed in random order at 2 intervals (lunch and dinner) for 2 hours each. Phase III was studied during three 6 hour-periods (after lunch, after dinner, and at night). The other quantitative manometric parameters were studied before (1 hour), during (2 hours), and after (2 hours) lunch and dinner. RESULTS: During the 2-hour postinfusion period, phase III reoccurred in 14 cases during the day and in 16 cases during the night. Phase III was always interrupted during feeding, which reoccurred in 14 cases during the 2-hour postinfusion period and in 16 cases during the after-dinner period. Nocturnal phase III was more frequent, lasted longer, with a lower amplitude than the diurnal phase. Addition of either soluble or insoluble fiber did not appear to have an influence on phase III or on the antroduodenal motor activity. CONCLUSIONS: Intragastric feeding interrupted phase III at the antroduodenal stage during infusion but was correlated with interdigestive motility. Antroduodenal motility did not significantly change either during or after intragastric feeding. The addition of either soluble or insoluble fiber does not seem to have an influence on gastroduodenal motor response to intermittent intragastric feeding.

Adult↗