Search PubMed⌕ Search

Biomedical subjects

A Ribet

Publications and source records attributed to A Ribet.

At least 19 recordsLinked to original sources
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

Postprandial cholecystokinin secretion in elderly with protein-energy undernutrition.

OBJECTIVE: Malnutrition is currently observed in aged people, and cholecystokinin is an important peripheral satiety signal. The aim of this study was to examine the effect of aging and protein-energy malnutrition on postprandial cholecystokinin (CCK) release. DESIGN: Non-randomized, cross-sectional comparison by age group. SETTING: Gastroenterology section of a teaching hospital. PARTICIPANTS: Twenty-one human volunteers divided into three groups: young healthy subjects (Group 1: mean 29 years, n = 7), aged healthy subjects (Group 2, mean 80 years, n = 7), and aged subjects with an important degree of malnutrition (Group 3, mean 84.6 years, n = 7). INTERVENTION: Each subject ingested a standardized liquid meal after an overnight fast. MAIN OUTCOME MEASURES: Plasma cholecystokinin was measured using a sensitive bioassay before and after the ingestion of the liquid meal. RESULTS: Basal cholecystokinin levels were similar (0.9 to 1 pM equivalent CCK-8) in the three groups. Postprandial levels were significantly increased over basal (P less than 0.05). The maximal cholecystokinin value was lower in Group 1 (3.5 +/- 0.8 pM equivalent CCK-8) and Group 2 (3.3 +/- 0.77 pM equivalent CCK-8) than in Group 3 (8.3 +/- 2 pM equivalent CCK-8) (P less than 0.05). Integrated plasma cholecystokinin was also similar in Group 1 (171 +/- 38 pM.60 min), (P less than 0.05). CONCLUSION: The increase of postprandial maximal levels of cholecystokinin is more related to malnutrition than to aging.

Adult↗
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

[Effects of biliary lithogenesis in acromegalic patients with long-term octreotide (SMS 201-995) treatment].

This study was performed to evaluate the risk of gallstone formation during long-term treatment with the long-acting somatostatin analog octreotide (SMS 201-995). Twelve patients (8 men, 4 women--mean age 43 years) treated with continuous subcutaneous octreotide infusion for acromegaly (mean duration 26.5 months, mean dose 541 micrograms/day) were included. Bile collection by duodenal intubation was performed before, during, and 45 days after octreotide treatment in 3, 12, and 8 patients, respectively. Abdominal ultrasonography and/or oral cholecystrography were also performed before (n = 9 patients), during (n = 12), and after treatment (n = 10). Bile examination was normal in the 3 patients controlled before treatment but showed that 58.3 percent of the treated patients had cholesterol monohydrate crystals. After discontinuation of octreotide only 25 percent of patients had cholesterol crystals. In 3 patients (25 percent) treated longer than 6 months, cholesterol crystals occurred prior to the occurrence of small radiolucent gallstones: one patient underwent cholecystectomy because of biliary colic, while in the two others, complete dissolution of stones was obtained after 10 months of treatment with ursodeoxycholic acid given in association with octreotide. None of the 9 other acromegalic patients (including 7 treated more than 20 months) developed stones. Cholesterol gallstone formation seems to be increased in acromegalic patients during long-term octreotide treatment but the exact incidence remains to be determined in larger series of patients.

Acromegaly↗
PubMed1990

Gastric lipase in alcoholic pancreatitis. Comparison of secretive profiles following pentagastrin stimulation in normal adults and patients with pancreatic insufficiency.

The aims of this study were to evaluate the amount of gastric lipase secreted by the stomach in normal adults and to elucidate a possible adaptative secretion of this enzyme in response to pancreatic insufficiency secondary to alcoholic chronic pancreatitis. Forty-one subjects underwent a gastric intubation. Pentagastrin (6 micrograms.kg-1.h-1 IV) significantly increased gastric lipase concentration and output. Stimulated gastric lipase output in seven normal subjects was 12,598 +/- 2036 U/h (by using tributyrin as substrate). Outputs where higher (P less than 0.02) in 17 patients with pancreatic insufficiency who were not drinking alcohol, but were not significantly different in nine patients who continued to drink (20,413 +/- 1778 U/h and 21,953 +/- 4973 U/h, respectively). On the other hand, high gastric lipase outputs were found in eight patients with duodenal ulcers and no evidence of pancreatic dysfunction (23,180 +/- 262 U/h). The time required to reach maximal lipase output (peak output) following pentagastrin stimulation was the same in all groups (approximately 38 minutes) except for the group of patients with pancreatic insufficiency who did not drink alcohol, in whom it was significantly reduced (approximately 26.5 minutes). Secretory patterns of gastric lipase and pepsin were closely comparable. Gastric lipase secretion could be increased in several clinical conditions and particularly in patients with pancreatic insufficiency caused by alcoholic chronic pancreatitis who have been abstinent for a long time.

Adult↗
PubMed1990

Protective effect of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced acute pancreatitis in rats.

This study was performed to assess the effects of misoprostol, a synthetic prostaglandin E1 analog, on cerulein-induced pancreatitis. Per group of 10 each, male Wistar rats received either cerulein (2.5 micrograms/kg/h subcutaneously), cerulein and misoprostol (500 micrograms/kg intraperitoneally at 0 and 4 h), or saline. Rats were killed 6 h after the first injection. Misoprostol treatment significantly reduced interstitial edema and acinar cell lesions induced by hyperstimulation. Pancreatic amylase and chymotrypsin contents were increased by cerulein and returned towards control levels in the misoprostol-treated group. The lysosomal volume density and the pancreatic beta-D-glucuronidase activity were significantly increased after hyperstimulation. The two parameters were significantly reduced by misoprostol. A protective effect of misoprostol against lesions induced by cerulein hyperstimulation would be a consequence of a lysosomal stabilizating effect.

Acid Phosphatase↗
PubMed1990

Amiloride and analogues inhibit Na(+)-H+ exchange and cell proliferation in AR42J pancreatic cell line.

To study the relation between activation of the Na(+)-H+ antiporter and gastrointestinal cell proliferation, we characterized this antiporter in a pancreatic cell line (AR42J) and studied the effects of mitogenic and nonmitogenic agents as well as those of Na(+)-H+ exchange blocking agents on DNA synthesis. Characteristics of amiloride-sensitive Na+ uptake were those of the Na(+)-H+ exchanger: 1) Na+ uptake was increased by intracellular acidification and depended on external [Na+] and pH; 2) concentrations for half-maximal inhibition (IC50) of Na+ uptake (3 mM [Na+] in medium) were 40 nM 5-(N,N-hexamethylene)amiloride (HA) less than 0.1 microM 5-(N-ethyl-N-isopropyl)amiloride (EIPA) less than 1 microM 5-(N,N-dimethyl)-amiloride (DMA) less than 40 microM amiloride; 3) IC50 for amiloride and analogues to inhibit Na+ uptake depended on [Na+] in medium (in 25 mM Na+ medium, the IC50 values were higher than in 3 mM and were 1 microM EIPA less than 10 microM DMA less than 0.3 mM amiloride). Growth factors for AR42J cells (dialyzed fetal calf serum and epidermal growth factor) activated Na+ uptake in a dose-dependent manner. Bombesin, which is nonmitogenic for AR42J cells, also increased Na+ uptake, indicating that activation of the antiporter is not sufficient to initiate cell proliferation in the AR42J cell line. The effects of Na(+)-H+ exchange blocking agents were tested on serum-stimulated cell proliferation. Decreasing external Na+ dramatically decreased AR42J cell proliferation. Amiloride and analogues inhibited [3H]thymidine incorporation in the same range of concentrations as that with which they inhibited Na(+)-H+ exchange.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1990

Na+/H+ exchange in AR4-2J cells: stimulation by growth factors and pancreatic secretagogues.

To study the relationships between activation of the Na+/H+ antiporter and gastrointestinal cell proliferation, we characterized this antiporter in a pancreatic cell line (AR4-2J). In the present study, the effects of mitogenic and non-mitogenic agents and of Na+/H+ exchange blocking agents on DNA synthesis are reported. Dialyzed fetal calf serum (FCS) (0-10%) increased amiloride-sensitive 22Na+ uptake in a concentration-dependent manner. There was a linear relationship between the increase in 22Na uptake and cell number when FCS was added in the 2-10% concentration range. Amiloride and analogs inhibited 3H-thymidine incorporation in the same concentration range as that with which they inhibited the Na+/H+ exchange. IC50 values were 1 microM for 5-(N-ethy-N-isopropyl)-amiloride (EIPA), 10 microM for 5-(N,N-dimethyl)-amiloride (DMA) and 0.1 mM for amiloride, respectively, indicating that activation of the Na+/H+ antiporter is necessary to initiate cell proliferation in AR4-2J cells. Maximal CCK9-induced 22Na uptake was 3.65 times the basal rate and was obtained at 0.1 nM. Maximal 22Na uptake triggered by unsulfated gastrin 17 was 2.51 times the basal rate and was obtained at 0.1 nM. The EC50s of CCK9 and gastrin in stimulating the 22Na uptake were similar at 1 pM. Maximal carbamylcholine-induced stimulation was observed at 0.1 mM and was 2.37 times greater than the basal rate. EC50 was 1 microM. In AR4-2J cells, the activity of the Na+/H+ exchanger seems to be directly involved in the control of cell proliferation. However, stimulation of this exchanger by stimulating factors that are not growth factors suggests that intracytoplasmic alkalinization could regulate other important metabolic processes which, as yet, are unknown.

Amiloride↗
PubMed1989

Protective effect of misoprostol, a synthetic prostaglandin E1 analog, on experimental pancreatitis induced by pancreatic duct ligation in rat.

This study was performed to assess the effects of misoprostol (M), a synthetic prostaglandin E1 analog, on experimental pancreatitis in rat. Pancreatitis was induced by ligation of the main pancreatic duct of 3-month-old male Wistar rats. Pancreatic lesions were observed at 6, 12, 24, 48, and 96 h after pancreatic duct ligation (PDL). A time of 48 h was chosen to evaluate M treatment. M was injected intraperitoneally (500 micrograms/kg every 4 h) between time 0 and 48 h after PDL. Stereological analysis was performed on light and electron microscopy. Total pancreatic amylase and chymotrypsin concentrations were determined. Four groups of five rats were studied: sham operated (SO), M without PDL (PG), duct ligation without M (DL), and duct ligation with M (DLPG). Edema, dedifferentiation of pancreatic acinar cells, and heterogeneous distribution of zymogen granule diameters observed after PDL were significantly decreased by M in the DLPG group. Enzyme concentrations were also decreased by M in the DLPG group. Enzyme concentrations were also decreased by M both in normal (PG) and duct ligated rats (DL). M has protective effects against pancreatic lesions induced by PDL. In this model, the protective effect of M may be due to a blockade of the autodigestive secretions of the pancreatic acinar cells.

Alprostadil↗
PubMed1989

Effect of long-term intraluminal perfusion of pentagastrin on rat small-intestinal mucosa.

Mucosal changes occurring during long-term intraluminal perfusion of pentagastrin in the duodenum of conscious adult rats (100 micrograms/24 h/kg, 6 days) were studied. Significant increases of labelling and of mitotic indices were noted in the whole small intestine, with an enlargement of the crypt epithelial proliferative compartment. Differential kinetic variations were observed between upper and lower parts of the small intestine when labelling indices were measured in accordance with the cell position in the crypts. Kinetic variations were correlated to the increases of villous and microvillous area. Alkaline phosphatase and leucine-aminopeptidase-specific activities were significantly increased, suggesting modifications of synthesis and/or maturation of these enzymes. The ileal Paneth cell number was also significantly increased in the ileum. Pharmacologic doses of pentagastrin intraluminally perfused have a trophic effect at all levels of the small-intestinal mucosa.

Alkaline Phosphatase↗
PubMed1989

[Comparative efficacy of famotidine and ranitidine in the treatment of acute-phase duodenal ulcer. A French comparative therapeutic trial].

This multicentric, double-blind and prospective study, which involved 41 French Gastroenterology Units, was designed to evaluate the efficacy and safety of famotidine, 40 mg at bedtime, compared to single dose ranitidine, 300 mg, in promoting the healing of duodenal ulcer. Two hundred and ninety-six patients with endoscopically proven duodenal ulcer were randomly allocated to 2 treatment groups: 148 were treated with famotidine, and 148 with ranitidine. Patients were treated during 4 weeks and then controlled by endoscopy. Unhealed patients at 4 weeks were treated again by the same drug for 2 weeks and then endoscopically controlled. One hundred and nine patients were evaluable in the famotidine group and 111 in the ranitidine group. Groups were well-matched for age, sex, alcohol and smoking habits, and duration of ulcer disease. At 4 weeks of treatment, 86 of the 109 patients treated with famotidine had healed (79 percent) and 74 of the 111 patients treated with ranitidine healed (67 percent). At 6 weeks of treatment, 104 patients had healed in the famotidine group (95 percent) and 101 in the ranitidine group (91 percent). Results were significantly different between the 2 groups at 4 weeks of treatment only (p = 0.039). Among smoking patients, no statistical difference was observed between the 2 groups at 4 and 6 weeks of treatment. By contrast, in non smoking patients, famotidine appeared more effective (83 percent healed) than ranitidine (67 percent) (p = 0.014) at 4 weeks. Both treatments were well tolerated and severe adverse effects were scarcely observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1988

[Aging of the pancreas. Its implication in malnutrition states in elderly persons].

The influence of ageing on exocrine pancreatic function was investigated in rats and in men. Young rats (3-months old, 150-200 g) and old rats (24-month old, 400-500 g) were killed after fasting overnight. Small pancreatic fragments were removed and kept for stereological analysis both in light and electron microscopy; in addition, levels of tritium-labelled leucine uptake and protein synthesis were measured by quantitative histoautoradiography on isolated acini in vitro. The human study was conducted retrospectively in 27 adults (mean age 36 +/- 1.5 years) and in 28 elderly subjects (mean age 72 +/- 0.6 years) with no clinical or radiological evidence of pancreatitis. Duodenal aspirates were taken over a 90 min period under secretin (0.5 U/kg.h) and cerulein (75 U/kg.h) infusion for comparisons of bicarbonate, lipase, chymotrypsin and amylase concentrations and outputs in the two groups. Elderly people were found to have significant and parallel decreases in bicarbonate, lipase and amylase output as compared to younger subjects (-40 per cent, P less than 0.001). The pancreatic deficiency was confirmed in rats by a significant decrease in zymogen volume density and zymogen diameter and a defect of protein synthesis with significant slowing down (-70 per cent, P less than 0.001) of newly synthesized protein transfer to the Golgian zone of acinar cells. Signs of exocrine parenchyma dystrophy (pancreatitis?) were also observed.

Adult↗
PubMed1988

The pharmacokinetics of bendazac-lysine and 5-hydroxybendazac, its main metabolite, in patients with hepatic cirrhosis.

We have studied the pharmacokinetics of bendazac and its major metabolite, 5-hydroxybendazac, in 11 patients with hepatic cirrhosis after the oral administration of a single 500 mg tablet of bendazac-lysine, and compared them with those obtained from 10 healthy adults. The rate of absorption of bendazac, as assessed by tmax and Cmax, is similar in patients and in healthy subjects. The drug is eliminated mostly by metabolism in healthy adults, more than 60% of the dose being excreted in the urine as 5-hydroxybendazac and its glucuronide. Hepatic insufficiency impairs this metabolism, a two-fold decrease in apparent plasma clearance (CL/f) being observed in the patients. Although the plasma unbound fraction of bendazac is increased in patients (the drug is highly bound to plasma albumin), the apparent volume of distribution (V/f) is unchanged. In consequence, the half-life of bendazac is increased two-fold in the patients. Impairment of metabolism decreases the formation of 5-hydroxybendazac, but metabolism remains the main route of its elimination. Renal excretion of bendazac accounts for about 10% of the dose in both patients with cirrhosis and healthy subjects. We conclude that in patients with severe hepatic insufficiency the daily dose of bendazac-lysine should be halved.

Adult↗