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J Frexinos

Publications and source records attributed to J Frexinos.

At least 19 recordsLinked to original sources
PubMed1992

Differences between jejunal myoelectric activity after a meal and during phase 2 of migrating motor complexes in healthy humans.

Using an intraluminal probe with six pairs of annular electrodes, the myoelectric activity of the proximal jejunum was recorded during 48-hr sessions in 16 healthy volunteers receiving evening and noon meals (1000 kcal) and breakfast (400 kcal). In 10 subjects receiving no drug, the characteristics of the migrating motor complexes (period, duration of each phase, velocity of propagation of phase 3, duration of the postprandial disruption) varied markedly between subjects but were relatively constant from the first to the second day of recording. Single spike bursts propagated at a rate of 2-5 cm/sec, clusters of 3-10 spike bursts propagated at a rate of 0.5-1 cm/sec, and similar clusters recurring repetitively each 1.5-2 min were observed after the meals and very rarely in the fasted state during phase 2 of nocturnal migrating motor complexes. In six subjects, oral administration of codeine (50 mg) 1 hr before a meal induced migrating motor complexes in the postprandial state, with characteristics similar to that observed in the fasted state except a longer duration of phase 2. Single spike bursts and isolated and repetitive clusters of spike bursts were observed during phase 2 of the codeine-induced migrating motor complexes and after meals preceded by placebo, but very rarely during the phase 2 of nocturnal (fasted state) migrating motor complexes. It is concluded that the patterns of jejunal contractions consisting of propagated single spike bursts and isolated or repetitive spike bursts characterize the postprandial state in healthy humans and are dependent upon digesta flow.

Adult↗
PubMed1992

Microscopic examination of bile directly collected during endoscopic cannulation of the papilla. Utility in patients with suspected microlithiasis.

The usefulness of microscopic examination of pure bile directly collected from the biliary tract during endoscopic retrograde cholangiography and without hormonal simulation was prospectively evaluated in 72 patients. According to clinical, biochemical, ultrasonographic, and radiographic data, the patients were separated into two groups: group 1, patients with proven stones (N = 50), and group 2, patients with suspected microlithiasis presenting symptoms suggestive of cholelithiasis but without evidence of macroscopic stones at echography or cholangiography (N = 22). Cholesterol crystals and/or bilirubinate granules were observed (eg, positive examination) in the bile of 41 of the 50 patients of group 1 (82%). Among patients of group 2, seven (32%) had a positive bile examination: cholecystectomy (N = 2) or endoscopic sphincterotomy (N = 5) disclosed minute stones in all cases. In the 15 patients of group 2 with a negative bile examination, cholecystectomy (N = 3), sphincterotomy (N = 2), and clinical (and/or echographic) 20-month follow-up (N = 9) revealed biliary lithiasis in only one patient, in whom recurrent cholangitis led to disclosure of one bile duct stone. According to these results, microscopic examination of bile samples collected during endoscopic retrograde cholangiography exhibited a sensitivity and a specificity for cholelithiasis recognition of 82.7% and 100%, respectively, with a positive predictive value of 88%. We conclude that the accuracy of this method makes it useful to investigate and manage patients with suspected microlithiasis.

Aged↗
PubMed1992

Cholecystokinin and gastrin induce cell contraction in pig ileum by interacting with different receptor subtypes.

The aim of this study was to determine the cholecystokinin (CCK) receptor subtype involved in the direct myogenic effect of CCK on pig ileum. Smooth muscle cells were dispersed from pig ileum circular muscle layer and incubated in the presence of various concentrations of CCK agonists and antagonists. Contraction was assessed by measuring the length of 50 cells and expressed as the percentage decrease in cell length from control. Maximal contraction varied between 19% +/- 3% (gastrin II, 10 nmol/L) and 26% +/- 3% [CCK octapeptide (CCK-8), 10 nmol/L]. EC50 for CCK tetrapeptide (CCK-4) was the same than for pentagastrin (30 pmol/L), which were more potent than CCK-8 (100 pmol/L) and unsulfated gastrin 17 (100 pmol/L), which in turn were more potent than unsulfated CCK heptapeptide (CCK-7; 300 pmol/L) and sulfated gastrin II (300 pmol/L). The maximal contraction induced by synthetic analogs of CCK was 22% +/- 1% for 1 nmol/L JMV 170 and 23% +/- 1% for 10 nmol/L JMV 180. EC50 was 10 pmol/L for JMV 170 and 800 pmol/L for JMV 180. Contraction induced by 10 nmol/L CCK was inhibited as follows: L 365,260 half maximal inhibition (IC50) = 1 nmol/L greater than L 364,718 (IC50 = 90 nmol/L) greater than proglumide (IC50 = 1 mumol/L). Contraction induced by 10 nmol/L unsulfated gastrin 17 was inhibited as follows: L 365,260 (IC50 = 1 pmol/L) greater than L 364,718 (IC50 = 60 nmol/L) greater than proglumide (IC50 = 4 mumol/L). Removal of Ca2+ from the extracellular medium did not alter the contraction induced by CCK-8 (10 nmol/L) but impaired the contraction induced by unsulfated gastrin 17 (10 nmol/L) -56% in Ca(2+)-free medium, -77% in Ca(2+)-free medium plus 2 mmol/L EGTA, and -70% in the presence of 1 mumol/L nifedipine. These results show that the CCK receptor of pig ileum smooth muscle cells is closely similar to the B receptor and is not dependent on an influx of extracellular Ca2+ to induce cell contraction. By contrast, gastrin could act through a specific receptor subtype, the "gastrin receptor," triggering a Ca2+ influx into the cell to induce cell contraction.

Animals↗
PubMed1992

Comparative effects of galanin on isolated smooth muscle cells from ileum in five mammalian species.

Effect of galanin and CCK8 were studied on isolated smooth muscle cells obtained from pig, guinea-pig, rat, rabbit and dog ileum circular muscle layer. Galanin as well as CCK8 induced a concentration-dependent contraction of pig, rat, rabbit and guinea-pig ileum smooth muscle cells. Maximal contraction ranged between 23.7 +/- 1.9% and 26.1 +/- 3.1% decrease in cell length from control in the presence of both peptides. This maximal contraction was obtained at 1 nM galanin in pig, rat, rabbit, 1 nM CCK8 in rat, rabbit, guinea-pig, at 10 nM galanin in guinea-pig and 10 nM CCK8 in pig. Concentrations of galanin inducing a half maximal contraction (EC50) ranged between 8 pM and 80 pM in these species. In dog, CCK8 induced a concentration-dependent contraction of ileum smooth muscle cells, with a maximal contraction (24.5 +/- 2.3%) at 1nM and an EC50 of 50 pM while galanin inhibited cell contraction induced by CCK8. The CCK-induced contraction was abolished at 10 nM galanin and 10 nM VIP. Concentrations of galanin and VIP inducing a half-maximal relaxation of contracted cells were 2 pM and 3 pM respectively. It is concluded that galanin may induce cell contraction of pig, guinea-pig, rat and rabbit ileum circular muscle layer and cell relaxation of dog ileum by a direct myogenic effect.

Animals↗
PubMed1992

Intracellular pathways triggered by galanin to induce contraction of pig ileum smooth muscle cells.

1. In order to determine the intracellular mechanisms by which galanin induces contraction of isolated smooth muscle cells from pig ileum, we examined the effects of external Ca2+, relaxing agents, pertussis toxin and forskolin on the galanin-induced contraction and compared these effects to those observed on the cholecystokinin derivative CCK8-induced contraction. 2. Galanin induced a concentration-dependent cell contraction. The maximal contraction (24.5 +/- 2.1% of the length of resting cells) was observed at 1 nM of galanin. When cells were incubated in the simultaneous presence of concentrations of galanin (10 fM) and CCK8 (1 pM) which were ineffective alone, or galanin (10 fM) and acetylcholine (100 pM), a synergistic action was observed corresponding to a submaximal contraction. 3. Incubation of cells in Ca(2+)-free medium caused a significant decrease in galanin- but not in CCK-induced contraction. Nifedipine, a Ca2+ channel blocker, provoked a concentration-dependent inhibition of galanin-induced contraction while it had no effect on the contraction induced by CCK8. 4. Vasoactive intestinal polypeptide (VIP) and isoprenaline, known to induce cell relaxation through an increase in intracellular cAMP level, inhibited CCK-induced cell contraction at concentrations ranging from 1 pM to 1 microM but failed to inhibit cell contraction induced by galanin. 5. When cells were pre-incubated for 3 h in the presence of 200 ng/ml of pertussis toxin, the contraction induced by galanin was abolished while the CCK-induced contraction remained unchanged. On the contrary, 10 microM forskolin abolished the contraction induced by 10 nM CCK but had no effect on galanin-induced contraction. 6. These results indicate that galanin induces a concentration-dependent contraction of pig ileum smooth muscle by a direct myogenic effect. This effect of galanin involves the activation of a pertussis toxin-sensitive G protein, which results in an influx of Ca2+ into the cell. This intracellular pathway is insensitive to the relaxing effect of cAMP.

Acetylcholine↗
PubMed1992

[Incidence, treatment and prognosis of cancer of the pancreas in Haute-Garonne (1982-1986)].

The characteristics of incident cases of pancreatic carcinoma found in the area of Haute-Garonne (France), as determined by the Digestive Cancer Registry, are reported. Two hundred and forty-six new cases were collected during a 5 year period in a population of 820,000 inhabitants. The annual standardized incidence rate per 100,000 inhabitants was 4.7 for men and 2.6 for women, respectively. This represents a low risk and corresponds to 7 percent of all intestinal tract tumors. The tumors were shown histologically to be adenocarcinoma in 85 percent of cases. The tumor was localized in the head of the gland in 64 percent of cases, while metastases were present at the time of diagnosis in 43 percent of cases. Ultrasonography was the initial investigation (44 percent of cases) and was performed well before endoscopic retrograde wirsungography (12.8 percent) and computed tomography (18 percent). Eighty-six percent of the patients were operated on. Curative surgery, however, was possible in only 12.5 percent of patients. The incidence of carcinoma remained stable during the observation period and no change was noticed with regard to housing conditions. During follow-up, 50 of 215 patients died within one month following the diagnosis (23 percent). Actuarial survival was 36 percent at 6 months, 17.4 percent at one year, and 3.6 percent at 3 years. These data were comparable to those observed in the Côte-d'Or and Calvados areas. These findings suggest that the French Digestive Tumor Registries should develop co-operative studies particularly in the analytic epidemiological fields.

Actuarial Analysis↗
PubMed1991

Galanin induces contraction of isolated cells from circular muscle layer of pig ileum.

The effects of galanin and its interaction with cholecystokinin and acetylcholine on smooth muscle cells were studied in vitro on isolated cells obtained from pig ileum circular muscle layer. Galanin induced a concentration-dependent cell contraction with a maximal contraction (24.5% decrease in cell length from control) obtained at 1 nM. The concentration of galanin inducing a half-maximal contraction was 3 pM. Tetrodotoxin (10 microM) failed to inhibit cell contraction induced by galanin (1 nM), pentagastrin (10 nM) and acetylcholine (1 microM). Atropine abolished the contraction induced by acetylcholine (1 microM), but had no effect on galanin- and pentagastrin-induced contraction. L 364,718 inhibited the contraction induced by CCK8 but not the galanin-induced contraction. At the uneffective concentration of 10 fM, galanin had a synergistic effect with an uneffective concentration of CCK8 (1 pM). These results suggest that (i) galanin contracts smooth muscle cells from pig ileum by acting on a specific receptor; (ii) galanin and either CCK or acetylcholine may act in a synergistic way to induce cell contraction.

Acetylcholine↗
PubMed1991

[Acute recurrent colonic pseudo-obstruction. Report of a case occurring during and following pregnancy and treated by total colectomy].

The authors report a case of multi-recurrent Ogilvie's syndrome during pregnancy, the post-partum period and a long time after deliver. Electromyographic and manometric studies excluded colonic inertia and disseminated gastrointestinal involvement. Total colectomy was performed after the 6th recurrence, resulting in complete cure of the patient.

Acute Disease↗
PubMed1990

Oral prostaglandin E analogues induce intestinal migrating motor complexes after a meal in dogs. Evidence for a central mechanism.

The effects of oral, intravenous, and intracerebroventricular administration of synthetic derivatives of prostaglandins E1 (misoprostol) and E2 (enprostil) on postprandial gastrointestinal motility were investigated in dogs chronically fitted with strain gauge transducers on the antrum and the proximal and middle jejunum. Synthetic prostaglandin E analogues administered orally at a dose of 20-50 micrograms/kg 15 min before the meal did not modify the postprandial pattern of gastric contractions but suppressed the spontaneous postprandial irregular activity on the jejunum and induced a cyclic pattern of migrating motor complexes for 4-6 h after the meal. These postprandial migrating motor complexes induced by prostaglandin E were propagated between the two recording sites and had a period similar to that observed in the fasted state. However, the duration of phase 2 was significantly increased and the amplitude of the phase 3 decreased. This jejunal cyclic motor pattern was reproduced by administration of synthetic prostaglandin E derivatives either intravenously (4-10 micrograms/kg) 15 min before the meal or intracerebroventricularly (50 ng/kg) 1 h after the meal. The intestinal migrating motor complex activity observed after oral administration of synthetic prostaglandin E derivatives was abolished by the previous intracerebroventricular (40 micrograms/kg) but not intravenous (200 micrograms/kg) administration of SC-19220, a receptor antagonist of prostaglandin E. These results suggest that oral administration of synthetic prostaglandin E1 (misoprostol) or prostaglandin E2 (enprostil) analogues before a meal induces postprandial migrating motor complexes on the jejunum in dogs through a mechanism involving central prostaglandin receptors.

Administration, Oral↗
PubMed1990

[Colonic motility in the irritable bowel syndrome].

The importance of colonic motor disorders during the irritable bowel syndrome is recognized, but, paradoxically, their description has yet to be perfected. Among the fundamental questions that remain unanswered, three are of prime importance: a) are there one or more specific disturbances in basal colonic motility? b) can specific motor disorders be induced by certain situations, for instance, during stress? c) is there any real relationship between clinical symptoms and coexisting motor disorders? The answers to these questions are full of ambiguities; this may be explained by the difficulty with which methods of investigation are performed as well as the heterogeneous character of the disorders. Presently, recording colonic myoelectric activity over a 24 hour period or more might prove to be useful in increasing our knowledge on motor disorders. It is not at all certain that a specific basal abnormality exists and the results of the effects of stress vary according to the methods used. Segmental hyperactivity in painful constipation, abnormal colonic response to alimentation in the case of painful bloating, and propulsive hyperactivity with absence or decrease in the "sigmoid brake" during painless diarrhea have been noted on basal motor activity recordings during sleep and after meals. Myoelectric disorders, however, are seen in only two-thirds of patients with intestinal functional disorders. "Sensitivity", personality, or other disorders, and particularly, intestinal disorders, can contribute to explain the pathophysiology of "irritable bowels" in which the role of colonic disorders has yet to be shown.

Action Potentials↗
PubMed1990

[Historical viewpoint on the irritable bowel syndrome].

Contrary to common thought, the conception of the irritable bowel syndrome (IBS) is relatively old, even if the current term dates from as recently as 1944. Long ago, several ancient, and disparate terms, some of them corresponding to currently exceptional clinical pictures, were used. Does that mean that these banal complaints, currently of prime importance among the clinical signs in gastroenterology, were left aside in favor of more severe disease? Surely this is not the case because functional pain has always existed, the only problem is to know whether it was or could be recognized. It was Amboise Paré who first mentioned an ancestor to the IBS when he spoke of "windy colic" (Le Miroir de Beauté et de Santé Corporelle). The glorious kingdom of nervous, chemical, motor, buccal, and intestinal disorders predominated in Gastroenterology at the end of the nineteenth century and the two diseases suggesting functional intestinal problems, i.e. enteroptosis and chronic intestinal stasis, were relegated to second place. Mucomembraneous entercolitis represents one of the most illustrated and widely described offsprings. At the beginning of the twentieth century, progress in roentgenology has allowed to dismember the category of colitis and distinguish between functional and organic diseases. Of the many terms used, "nervous colic" and "irritable intestine" are two which suggest the pathophysiological duality of the disease. Further development of studies on colonic and intestinal motility should allow to identify the authentic motor disorders, even though some etiologies may still go recognized...

Chronic Disease↗
PubMed1989

[Colonic motility and irritable colon].

The importance of colonic motility disorders in the irritable bowel syndrome is now well accepted, but an accurate description of these abnormalities is still wanting. The insufficiency of investigational methods and, mainly, the heterogeneity of the disorders can explain this need. Twenty-four hour recordings of colonic myoelectrical activity can now provide a better knowledge of motor disturbances. No evidence of a specific basic disorder has been presented, and the effects of stress produce contradictory results depending on the method used. In contrast, motility patterns recorded during sleep and after a meal show segmental hyperactivity in painful constipation, abnormalities of the colonic response to feeding in painful abdominal distension, propulsive hyperactivity with absence or reduction of the "sigmoidal brake" in painless diarrhea. However, it appears clearly that myoelectrical activity disturbances can only be observed in two thirds of the patients presenting with functional digestive disorders. "Sensitivity" or personality disorders and disturbances of other organs can explain the physiopathology of "irritable bowels" where no evidence can be found that the colon is involved.

Animals↗
PubMed1989

Effects of sennosides on colonic myoelectrical activity in man.

The effects of sennosides on colonic myoelectrical activity were investigated in man. Spiking activity of the left and sigmoid colons was continuously recorded in seven constipated patients during two sessions from 5:00 PM to 9:00 AM. Each patient received orally at 7:00 PM on two consecutive days 30 mg of sennosides one day (sequence S) and placebo on the other (sequence P) in a random fashion. A significant (P less than 0.05) increase of peristaltic activity (migrating long spike bursts or MLSBs) after sennosides was observed between 1:00 and 7:00 AM, and a corresponding decrease between 7:00 and 9:00 AM. No change was noted in total short spike burst (SSB) activity or in SSBs characteristic of the rectosigmoid area. This study indicates that the main modification of colonic motility induced by sennosides was a stimulation of propulsive activity (MLSBs), which occurred between 6-12 hr after oral administration, the delay required for orocecal transit and metabolism of the drug.

Action Potentials↗
PubMed1989

Rectal potential differences in irritable bowel syndrome and in inflammatory bowel diseases in man.

We have studied rectal potential difference (pd) in 200 subjects: 30 healthy volunteers or control patients, 46 patients with irritable bowel syndrome (IBS) and painless diarrhoea (group I), 60 IBS patients without diarrhoea (group II) and 64 patients with inflammatory bowel disease (IBD) with (group III, n = 41) or without (group IV, n = 23) rectal involvement. Pd measurement used a rectal perfused probe and a subcutaneous needle both connected, via agar-KCl bridges, to calomel electrodes and a millivoltmeter. Statistical analysis used Student's t-test for paired and unpaired data and Mann-Whitney U-test as appropriate. Mean rectal pd values were, respectively -43.5 +/- 8.7 mV in control group, -32.9 +/- 10.2 mV in IBS-group I patients (P less than 0.001), -41.3 +/- 12 mV in IBS-group II patients (NS), -21.4 +/- 14.1 mV in IBD patients with rectal involvement (P less than 0.001), and -45.1 +/- 14.3 mV in IBD-group IV patients (NS). A histological examination was performed in 36 IBS patients; mean rectal pd was significantly decreased in patients showing abnormal patterns (n = 27, pd = -31.8 +/- 9 mV) compared to patients with normal mucosa (n = 9, pd = -41.1 +/- 6.5 mV; P less than 0.01). These results show that: (1) potential difference is significantly decreased in patients with ulcerative and rectal involvement; (2) in patients with Crohn's disease, normal rectal pd values do not assess the appearance of colonic mucosa above; (3) patients with IBS and diarrhoea also present a significant diminution in mean rectal pd. Although the mechanisms involved remain unclear, rectal pd measurement appears to be an objective test for intestinal mucosae weakness in functional or inflammatory diseases of the large intestine and rectum.

Adult↗
PubMed1989

[Efficacy and tolerability of enprostil in the treatment of duodenal ulcer. Comparison with cimetidine].

Enprostil, a synthetic PGE2, has been shown to have an inhibitory effect on gastric acid secretion, a mucoprotective effect and a postprandial lowering effect on gastrin. A double blind randomized study was performed in 80 patients, in order to evaluate the efficacy and safety enprostil (35 mu b.i.d) as compared to cimetidine (400 mg b.i.d) in duodenal ulcer. Healing rates after two, four and six weeks of treatment, as based on endoscopic evaluation, were 35, 72 and 83 p. 100 for enprostil and 45, 73 and 83 p. 100 for cimetidine, respectively. There were no significant differences between treatment groups. The time to relief of nighttime and daytime ulcer pain and antacid consumption were similar in the two groups. The patient's overall subjective assessment was better in the cimetidine group, but this was not confirmed by physicians' opinions. Diarrhea was observed in 7 p. 100 of patients treated by enprostil compared with 5 p. 100 for patients treated by cimetidine. One enprostil treated patient withdrew from the trial prematurely because of abdominal pain. This study demonstrates the efficacy and safety of enprostil in the treatment of active duodenal ulcer at the dosage of 35 micrograms twice daily.

Adult↗
PubMed1989

[Functional study, in man, of congestive gastropathy in cirrhosis by measurement of potential difference].

The morphologic features of the gastric mucosa in patients with cirrhosis have been well investigated. The aim of this study was to evaluate its functional disruption by measuring the gastric potential difference. Forty patients were investigated, 12 control subjects and 28 consecutive cirrhotic patients with endoscopically proved congestive gastropathy. Potential difference was measured the morning, on an empty stomach, at least 3 days after endoscopy; the method used a double channel gastric perfused probe placed under fluoroscopy 10 cm above the cardia, and a subcutaneous reference, both connected to a millivoltimeter via gelose agar-KCl bridges. Potential difference was recorded in each case 20 min before (baseline) and after local instillation of lysine acetylsalicylate (500 mg) as a provocative test. Cirrhotic patients had significantly lower basal potential difference than controls (-28.3 +/- 1.5 mV vs -33.8 +/- 1.3mV, p = 0.007). Potential difference was significantly lower in patients with severe gastropathy than in patients with mild gastropathy (-20.5 +/- 2.1 and -28.9 +/- 1.6 mV, respectively, p less than 0.01). After stimulation with acetylsalicylate, the area under curve and the irritability index were greater in patients with gastropathy (81.4 +/- 12.8 vs 41.2 +/- 8.6 mV.min, p = 0.032 and 0.935 +/- 0.19 vs 0.290 +/- 0.07 mV.mV.min, p = 0.022, respectively). These differences were explained by a higher drop in potential difference (delta DPmax/baseline; 28.1 +/- 3 vs 16.1 +/- 3 p. 100, p = 0.006) whereas basal return time remained unchanged (16.2 +/- 2.1 vs 13.7 +/- 2.2 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗