Biomedical subjects

M Bouchoucha

Publications and source records attributed to M Bouchoucha.

At least 19 recordsLinked to original sources

PubMed2006

Different segmental transit times in patients with irritable bowel syndrome and "normal" colonic transit time: is there a correlation with symptoms?

BACKGROUND: The Rome criteria serve as gold standard for establishing a diagnosis of irritable bowel syndrome (IBS), but only represent a cluster of symptoms. On the other hand, measurement of colonic transit time (CTT) with radiopaque markers is a solid and more objective method to quantify functional abnormalities. The goal of this study was to investigate whether the IBS symptoms, as defined in the Rome II criteria, correspond to objective physiological parameters, i.e. CCTs. METHODS: The study enrolled 148 healthy control subjects and 1385 consecutive IBS patients. Transit times were measured for the whole rectocolon (overall CTT) and for 3 segments (right colon, left colon, rectosigmoid area); segmental distribution of markers and diffusion coefficients were also assessed. In order to analyze homogeneous groups, we restricted analysis to subjects with "normal" CTT (< or =70 hours). RESULTS: Six hundred forty four IBS patients (46%) and 14 control subjects (9%) had CTT >70 h and were eliminated. In subjects with CTT < or =70 h, CTT did not follow a normal (Gaussian) distribution. We identified 3 different CTT clusters in healthy controls and 4 clusters in IBS patients. Even if CTT was not significantly different between clusters, each cluster was characterized by a specific pattern of segmental colonic transit. There was a marked gender difference: women had longer overall CTT values than men, both in control and IBS patient groups (p<0.001). However, female IBS patients had significantly shorter colorectal transit times than female controls (p<0.001), as well as faster transit than in men through the left colon and rectosigmoid area. There were no significant differences in transit time between male IBS patients and male controls with the exception of a faster rectal transit in IBS patients (p<0.01). There was no association between segmental colonic transit values and sign or symptoms comprising the Rome II criteria. CONCLUSIONS: In subjects with CTT < or =70 h, CTT does not follow a normal distribution but is clustered in subgroups that can be distinguished only by measuring segmental colonic transit. Within these subgroups, there is a marked difference in transit times between IBS patients and normal subjects, suggesting that IBS patients with "normal" CTT are not "normal". The Rome II criteria do not reflect differences in segmental transit times in IBS patients with "normal" CTT. We therefore propose to evaluate segmental transit times in IBS patients with "normal" CTT, before and after treatment, in order to correctly interpretate variations in signs and symptoms. These findings have important implications in evaluating the effect of drugs on bowel function and should help define better inclusion criteria for studies evaluating new drugs for the treatment of IBS.

Adolescent↗

PubMed2001

Anal sphincter response to distension.

Resting anal pressure as determined by manometry is unsuited for assessing the competence of a sphincter. To validate a compliance method of sphincter evaluation we investigated the response of the anal canal to distension. In 20 healthy subjects the anal sphincter was distended using a cylindrical balloon probe subjected to continuous inflation. Two speeds of distension were used: 12 and 80 ml/min. Deflation, at the rate of inflation, immediately followed the inflation at 12 ml/min, and at 80 ml/min was performed after a deformation volume of 12 ml was maintained for 2 min. The response of the anal sphincter to 12 ml/min distension was characterized by an initial phase of resistance followed by relaxation of the anal sphincter in all subjects. In contrast, at 80 ml/min no opening was obtained. During the deformation a biomechanical relaxation curve was recorded. We conclude that the anal sphincter acts as a low-pass filter and not only as a pressure barrier. The response of the anal sphincter to distension is a simple test, which provides functional information on the behavior of the anal sphincteric zone.

Adult↗

PubMed2000

Effects of oral pinaverium bromide on colonic response to food in irritable bowel syndrome patients.

We have recently developed a simple method to investigate the colonic response to food (CRF). This study describes the modifications of CRF induced by treatment with oral pinaverium bromide in irritable bowel syndrome (IBS) patients. Thirty healthy subjects and 43 patients suffering from IBS were studied. Colonic transit time (CTT) was measured in fasting conditions and after eating a standard test meal. Colonic response to food was quantified by calculating the variation in number of markers in each zone of interest of the large bowel between the X-ray films of the abdomen taken before and after eating. CRF is characterized by caudal propulsion of colonic contents in the two groups. In controls, there is emptying of the caecum-ascending colon region and filling of the rectosigmoid. In IBS patients, only the left transverse colon and the splenic flexure empty. Pinaverium bromide exerts no effect in controls but reverses the CRF of the right colon in IBS patients by inhibiting right colon emptying. These results suggest that the inhibitory action of pinaverium bromide on CRF may support the clinical efficacy of this calcium channel blocker in the treatment of IBS.

Adult↗

PubMed2000

Error analysis of classic colonic transit time estimates.

Estimates of colonic transit times (CTT) through the three colonic segments, right colon, left colon, and rectosigmoid, are commonly based on radiopaque markers. For a given segment, CTT is usually calculated from just the number of markers visible in that segment on abdominal X-rays. This procedure is only strictly valid for the theoretical, but unrealistic, case of continuous marker ingestion (i. e., not for a single or once-daily ingestion). CTT was analyzed using the usual estimate of the mean CTT of one marker and also using a new, more realistic estimate based on the kinetic coefficients of a three-compartment colonic model. We directly compared our compartmental approach to classic CTT estimates by double-marker studies in six patients. We also retrospectively studied CTT in 148 healthy control subjects (83 males, 65 females) and 1,309 subjects with functional bowel disorders (irritable bowel syndrome or constipation). Compared with the compartmental estimates, the classic approach systematically underestimates CTT in both populations, i.e., in patients and in healthy control subjects. The relative error could easily reach 100% independent of the site of colonic transit delay. The normal values of total CTT are then 44.3+/-29.3 instead of 30.1+/-23.6 h for males and 68.2+/-54.4 instead of 47.1+/-28.2 h for females.

Adolescent↗

PubMed1999

Anal pressure waves in patients with irritable bowel syndrome.

PURPOSE: Many data suggest in irritable bowel syndrome a generalized smooth-muscle disorder, but data are scant concerning anal waves in patients with irritable bowel syndrome. The aim of the present study was first to propose a new method of anal pressure-wave analysis and second to apply this method to patients with irritable bowel syndrome. METHODS: Spectral analysis was used in 20 healthy controls and 60 patients with irritable bowel syndrome to investigate anal pressure waves at rest during a standard anorectal test and during a maintained 12-ml anal distention. RESULTS: Adaptation of the anal canal to maintained distention was similar in the two groups of subjects. Using a cluster analysis, three groups of anal waves were defined (in cycles per minute): ultra slow waves (0.9-3.3), slow waves (3.8-16.4), and simple waves (16.9-23). In the resting state only simple waves were found less prevalent in patients with irritable bowel syndrome. During maintained distention, ultra slow waves increase in both groups, but slow waves increase in patients with irritable bowel syndrome and simple waves decrease in controls. CONCLUSIONS: Characterization of anal pressure waves is a simple procedure that is easy to perform in outpatients. Anal pressure waves of patients with irritable bowel syndrome have altered organization and respond differently to distention as compared with controls.

Adult↗

PubMed1999

Temporal and spatial rhythmicity of jejunal wall motion in rats.

Isolated segments of jejunum of fasted rats exhibit regular rhythmic contractions at the same frequency as slow-waves. The aim of the present study was to search for a possible spatial rhythmicity of this activity. Using a video imaging technique, jejunal segments of 50 rats were studied. Only experiments (n=76) with no propagated contractions at visual inspection were included in the study. After the measurement, a spectral analysis of the diameter variations was performed. The bands were characterized by four parameters: level, main frequency, amplitude and phase. At each level, the phase varied, suggesting that the same rhythmic phenomenon occurred, but with a delay as a function of the spatial position. In 58 measurements, the rhythmic activity had a frequency near 0.50 Hz and in 18, near 0.25 Hz. Phase difference was found in 32 segments (42%). The variation with distance was linear as a function of time and its length was greater for the low-frequency group than for the high-frequency group (25.6 +/- 9.4 vs. 33.3 +/- 5.2 mm, P=0.015). By contrast, the speed of propagation was not significantly different. The wavelength lambda of the spatial rhythmicity was 27.7 +/- 23.2 and 9.8 +/- 4.2 mm (P=NS) in the high- and low-frequency groups, respectively. This corresponds to a speed of propagation of v=lambda*f, where f is the frequency of the wall motion (7.0 +/- 5.2 vs. 5.2 +/- 2.2 mm sec-1, P=NS).

Algorithms↗

PubMed1998

Silent gastroesophageal reflux disease in patients with pharyngolaryngeal cancer: further results.

BACKGROUND: Gastroesophageal reflux disease is associated with various head and neck manifestations. The aim of this retrospective study was to determine the incidence of asymptomatic, or "silent," gastroesophageal reflux disease (GERD) in patients treated for pharyngolaryngeal squamous cell carcinoma. METHODS: Twenty-four-hour pH monitoring was performed in 72 consecutive patients without digestive manifestations (pyrosis, retrosternal heartburn) of GERD treated for pharyngolaryngeal carcinoma. Statistical analysis of the relationship between reflux scores achieved and various patient parameters (age, tobacco and alcohol consumption, gastric ulcers, medications which decrease esophageal sphincter pressure), tumor parameters (staging), and therapeutic parameters (drugs administered during neo-adjuvant chemotherapy) was performed. RESULTS: Incidence of silent GERD varied from 36% to 37% according to the reflux scores. No relationship was found between the reflux scores and the patient or tumor parameters. Among the therapeutic parameters, a statistical relation was noted between the total dose of Cisplatin and the reflux scores (p = .005). CONCLUSIONS: Silent GERD is a common finding in patients treated for squamous cell carcinoma of the pharyngolarynx. Additionally, chemotherapy including Cisplatin may aggravate GERD during the course of therapy.

Adult↗

PubMed1998

Simple clinical assessment of colonic response to food.

The colonic response to food (CRF) is an integrated function of the colon that has been poorly studied in clinical practice. This study describes a new method to measure it, based on the progress of radio-opaque markers, and shows the results in healthy subjects and in patients with irritable bowel syndrome (IBS). Thirty healthy subjects and 43 patients suffering from IBS were studied. Two studies of colonic transit time (CTT), at rest and after eating a standard test meal, were performed. CRF was quantified by calculating the variation in number of markers in each zone of interest of the large bowel using X-ray films of the abdomen taken before and after eating. The results were as follows: (1) CRF is characterised by caudal propulsion of the colonic contents in the two groups. In controls, there is emptying of the cecum-ascending colon region and filling of the distal large bowel. In IBS patients, only emptying of the left transverse colon and the splenic flexure is found. (2) IBS patients have a delayed CTT because of slowing in the right and left colon, and this is both before and after a meal. The determination of the movements of markers after eating is a simple method that is useful in clinical practice to evaluate CRF.

Adult↗

PubMed1997

Diversion-related experimental colitis in rats.

PURPOSE: Diversion-related colitis is an inflammatory process that affects the colon and/or rectum distal to a colostomy. Its mechanisms are unknown, and many hypotheses have been considered. The aim of the present study was to create an experimental model of diversion-related colitis in rats, so in the future it will be possible to test different hypotheses. METHODS: Three groups of ten male Wistar rats were used for the study. Two groups underwent a colostomy and were kept alive for 6 or 17 weeks. One group of rats was killed at the onset of the experiment. Specimens were taken in bypassed segments in the rats who had had a colostomy and in the sigmoid colon for the control group. Histologic analysis using standard coloration, histochemical techniques, and bacterial preparation was used to find histologic or changes of colonic histology or flora. RESULTS: Exclusion was associated with vascular congestion, a decrease in length of glandular crypts (P < 0.01), and an erosion of surface epithelium; inflammation of the mucosa was absent in all control animals and present in all test animals. In contrast, the number of goblet cells was not changed by the procedure. There was also a significant change in distribution and intensity of sulfomucins and sialomucins and quantitative and qualitative changes of the colonic flora. CONCLUSION: This experimental model of diversion colitis is characterized by histologic and bacteriologic modifications comparable with those reported in humans but with different histochemical changes.

Animals↗

PubMed1997

Relationship between acid neutralization capacity of saliva and gastro-oesophageal reflux.

Saliva is an important factor in neutralization of oesophageal acid exposure, clinically manifested as gastrooesophageal reflux (GOR). The aim of this study is to compare the composition and the "capacity in acid neutralization" (CAN) of saliva in controls and patients suffering of GOR. We compared the composition of saliva from 56 patients who had symptoms of GOR with that of saliva from 20 healthy control subjects. After a standardized 24-hour period of pH-monitoring, 39 patients had normal pH reflux scores (normal acid score: NAc-GOR) and 17 had abnormal pH reflux scores (pathological acid score: PAc-GOR). Then, following a 10-h fast, total saliva was collected during ten minutes in all patients and in the healthy control subjects. The composition of the saliva samples was analysed and the titration curve was determined on 200 microliters aliquots by successive addition of 5 microliters volumes of 0.1 N Hcl. The GOR patients had significantly lower salivary concentrations of Na+ and of both free and bound sialic acids and had higher salivary concentrations of inorganic phosphates than the controls. These disorders were more marked in PAc-GOR patients. Initial pH was 7.43 +/- 0.43 in controls, 7.35 +/- 0.45 in NAc-GOR patients, and 6.91 +/- 0.53 in PAc-GOR patients. In the beginning of the titration curve, PAc-GOR patients were significantly different from NAc-GOR patients and from controls. Saliva of both groups of patients presented significant differences in the acidic portion of the titrations curves, at high volumes of added HCl. These data show that the composition of saliva was modified in patients with GOR disease compared to that of normal subjects. A difference in titration curves was also observed with a higher acidic buffering capacity in these GOR patients. The modifications in saliva composition suggest a role for inorganic phosophates in the acid neutralization capacity observed in GOR, perhaps linked with a adaptation to chronic acid exposure.

Adult↗

PubMed1997

In vitro analysis of rat intestinal wall movements at rest and during propagated contraction: a new method.

Intestinal wall motions are not easily studied and are frequently deduced from manometric and electromyographic measurements. This study aimed to establish a method of wall movement analysis based on an automatic technique of image processing. Segments of rat jejunum were fixed in an organ bath under isometric conditions. A real-time edge-detection algorithm was used to find the contours of the intestine using video imaging. After the measurement, a mapping of intestinal wall movements was performed based on diameter variations. In the 260 experiments without stimulation, intestinal wall activity was always detected. Propagated activity was found in 40% of the experiments and periodic wall motion in 60%, with 0.5-Hz activity found more frequently (41%) than 0.24-Hz activity (19%). These cyclic activities, related to intestinal slow waves, had their amplitude decreased by acetylcholine and were modified by vapreotide. Analysis of a propagated wave after cholinergic stimulation showed that it is characterized by an increase of the diameter of the intestine followed by a decrease. Moreover, this methodology allows analysis of the initiation of a propagated wave.

Acetylcholine↗

PubMed1997

Adaptation of the rectal wall to distension in children with constipation.

OBJECTIVE: To determine whether there is significant change in the tension-length relationship of the digestive smooth-muscle mechanical function in constipation in children and to examine a new method of analysis of the mechanical properties of the rectal wall. DESIGN: Case-control study. PARTICIPANTS: Thirty children with constipation and 30 control children who did not have constipation. INTERVENTION: Rapid distension of the rectal wall by inflation of a rectal balloon with air. MAIN OUTCOME MEASURES: The in vivo rectal pressure-volume P[t,V] curve was determined according to the quasilinear viscoelasticity law. The recorded pressure was defined as the product of 2 functions: the elastic response P0[V] and the reduced relaxation function G[t], a normalized function of time such that P[t,V] = P0[V] x G[t]. Analysis of variance with repeated measures and modelling (linear for P0[V] and exponential plus constant term for G[t] were used for data analysis. RESULTS: The quasilinear viscoelastic law can be applied to the in vivo determination of the mechanical properties of the rectal wall in controls and in children with constipation. The elastic response was similar in the 2 groups. The reduced relaxation function was significantly different between the 2 groups, with the absence of an asymptotic value in the group with constipation (p < 0.01). CONCLUSION: Distension of the rectal wall with the use of an air-inflated balloon, with this type of interpretation according to the viscoelastic law, is useful in the analysis of chronic constipation.

Adaptation, Physiological↗

PubMed1996

Methodological factors affecting esophageal clearance.

To define some methodological factors that could affect the measurement of the esophageal clearance, we used three different protocols, on 41 healthy control subjects. In 20 subjects, we studied the influence of a naso-esophageal probe on the frequency of swallowing. We observed a significant (44 +/- 5%) decrease in the frequency of spontaneous swallows after 15 minutes, with stabilization after this 15 minute period of adaptation. In 11 subjects, we studied the influence of the pH of the esophageal content on esophageal clearance. We found an exponential relationship between the esophageal clearance (C) expressed in minutes and the initial pH of the lumen contents: C = 43.3 exp (-0.54 pH) In 10 other subjects, we studied the influence of the volume of the esophageal contents on esophageal clearance. We found no influence for volumes less than 30 ml and a significant increase of clearance for volumes greater than 30 ml. In summary, this study of the effects of methodological factors on esophageal clearance: Gives new information about the "accommodation phase" of the esophagus after distension by a naso-gastric probe; Allows us to propose a new quantitative method for evaluation of esophageal clearance Shows the small importance of the ingested volume.

Adult↗

PubMed1996

[A new approach of functional recto-anal exploration: the compliance of the rectum and the anal canal].

We have developed an original method of determining the rectal and the anal compliance. The rectum must serve as a fecal reservoir. This storage function requires that the rectum must be distensible. The anal canal must become easily looser for defecation. These features are not explored by the usual rectoanal manometric recordings. Very few investigations about the compliance are carried out. In our procedure, exploration balloons are connected via polyethylene tubes to pressure transducers, direct-writing electrical recorder and pump under the command of the computer. The pressure generated is as high as the distensibility is poor, as the compliance is decreased. The pressure/volume curve shows the compliance. The procedure is different for the rectum on the one hand, and for the anal canal on the other. The rectal device consists of a balloon at the end of the tube. It shall be inflated until only 60 ml., and then deflated at the same rythm, which is constant during each test. The first test takes place at the speed of 30 ml. per minute; so the inflation lasts 2 mn and the deflation the same time, afterwards the second test lasts one mn for each one, and finally the third one 40 seconds in the same way. For the anal canal, the balloon, ring shaped around the tube, measuring an inch in length, is inflated at only 12 ml. For the first test the inflation and deflation rate of speed is 3 ml per mn, afterwards 6 ml./mn then 9 ml./mn. and thereafter 12 ml./mn/; these series are done in randomized order. In both procedures, an additional relaxation test at the maximum of inflation takes place for 2 minutes. We have explored ten healthy volunteers and 120 patients suffering from various digestive diseases. The curves show the rectal compliance, and in the case of the anus a relaxation, which seems to be an active opening, occurs for a distension of 5-8 ml, i.e. 19-21 mn in diameter. In pathology, the excess of compliance is observed in patients with incontinence, whereas an inadequate compliance is seen in the dyschesia, descending perineum and prolapse, traumatic or surgical injuries, etc. This exploration will be a useful guide for the choice of the convenient treatment and the follow-up.

Adult↗

PubMed1995

Compartmental analysis of colonic transit reveals abnormalities in constipated patients with normal transit.

1. The aims of this study were to investigate if compartmental analysis can be used to analyse colonic transit measurements and to search for a relationship between transit time and the parameters deduced from this analysis. In addition, an attempt was made to determine if such analysis could reveal a functional abnormality in patients who complain of constipation but have normal colonic transit. 2. The subjects included 11 healthy controls, 10 patients with chronic diarrhoea and 55 constipated patients. Segmental and total colonic transit time were measured using a previously described method. Compartmental analysis was based on a three-compartment system, with k1, k2 and k3 being the coefficients of diffusion out of the right colon, the left colon and the rectosigmoid area respectively. 3. Patients complaining of constipation who had delayed transit time were the only subjects to have lower values of coefficient k1 than controls. k2 was lower than normal in all patients complaining of constipation, but this decrease was more marked in subjects with delayed colonic transit time than in subjects with normal colonic transit time. All patients complaining of constipation had lower values of k3 than control subjects. 4. This study shows that analysis of colonic transit time is feasible using a simple diffusion law, and that the results are correlated to clinical data. Moreover, this analysis permits detection of abnormalities in two groups of subjects: those who complain of constipation but are labelled as having normal colonic transit time and those who have chronic diarrhoea.

Adult↗

PubMed1995

Colonic transit in soccer players.

To evaluate the effects of exercise on colonic function, we measured total and segmental transit times in 11 male soccer players and nine male radiology student technicians. Diet was kept constant in all subjects, who maintained their normal activities. For the soccer players, normal activities included 15 h of training and one match each week. Transit times were measured with radioopaque markers, using the multiple-ingestion, single-radiograph technique. No overall difference in large bowel transit was observed between the two groups. Right colon transit was considerably slower in the soccer players, whereas left colon and rectal transit were slightly accelerated. We conclude that an intensive sport activity only modifies regional differences in large bowel function. This may be of importance in extreme conditions, such as those experienced by marathon runners. Data should be obtained before prescribing exercise to treat constipation.

Adult↗

PubMed1994

Variation of rheological properties of the human rectal wall with distending volume.

Pressure-relaxation curves of in vivo human rectal wall were studied in 30 normal children for 5 volumes of distension, 10-50 ml, to define the conditions of application of the quasi-linear viscoelastic law. Three normalization methods were compared: the use of the maximum pressure of the curve, the use of the first measured point after the rectal distension, and the use of the passive state defined as the inferior envelope of the experimental curve. Analysis of variance with repeated measures was used for data analysis. It was shown that: i) the first relaxation curve, corresponding to a 10-ml distension volume, was significantly different from the other curves (p < 0.0001); ii) the quasi-linear viscoelastic law could be applied to the in vivo determination of the mechanical properties of the rectal wall, when considering the mean level of the measured points; and iii) the shapes of the experimental curves at different level of distension were significantly different (p < 0.0001). We conclude that the hypothesis of quasi-linearity is appropriate, in a first approximation, as a model of rheological properties of the rectal wall.

Adolescent↗

PubMed1992

What is the meaning of colorectal transit time measurement?

This study was done to understand the different available methods used to calculate colorectal transit times. A single abdominal radiograph is taken following six successive daily ingestions of the same number of identical radiopaque markers. This method correlates well (P less than 0.001) with that using a single ingestion of markers with daily x-ray films until total expulsion. In techniques used to measure colorectal transit time with multiple ingestion of markers, the number of days of ingestion depends on the kinetics of marker defecation. This was found to differ markedly in various groups of control subjects and constipated patients (P less than 0.001) and can be used to obtain reliable data, even in subjects with severe constipation. When they ingest 20 markers, constipated patients are found to retain eight or more markers three days after ingestion, and taking a plain film of the abdomen on that day is sufficient to make a diagnosis of constipation. Transit time studies are reproducible from month to month in patients with an irritable bowel syndrome. Control subjects who claim that their bowel habits are not modified by stress have shorter transit times, similar in both sexes, than those who say they are (P less than 0.001). This may explain why a large percentage of constipated patients have been found by most authors to have "normal" colorectal transit times. The choice of control subjects is thus a key element in studies of functional bowel motor disorders. Stool frequency and consistency, in health, correlate only to rectosigmoid transit time.

Adult↗