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Biomedical subjects

R Laugier

Publications and source records attributed to R Laugier.

At least 55 records · Page 3Linked to original sources
PubMed1993

Purification of human gastric lipase by immunoaffinity and quantification of this enzyme in the duodenal contents using a new ELISA procedure.

Human gastric lipase (HGL) is the first lipolytic enzyme involved in the digestion of dietary lipids along the gastrointestinal tract. We describe an improved procedure for isolating the enzyme using immunoaffinity chromatography in combination with ion-exchange chromatography. The purified enzyme, showing a single band on SDS-PAGE, expressed a specific activity of 1000 U/mg using tributyrin as the substrate. We also describe a specific enzyme-linked immunosorbent assay (ELISA) procedure for measuring duodenal HGL levels. The ELISA was performed using an anti-HGL polyclonal antibody (pAb) as the captor antibody and a biotinylated monoclonal antibody (mAb) as the detector antibody. With the double sandwich ELISA technique, HGL in the range of 1-60 ng/ml was measured in less than 5 h. Identical HGL concentrations were obtained using the above ELISA procedure when compared to those based on the enzymatic activity using the potentiometric method (correlation coefficient: r = 0.95). No significant interference from other duodenal components was observed, as proved by the quantitative HGL determinations performed on intestinal samples.

Chromatography, Affinity↗
PubMed1993

[Therapeutic ultrasonography in case of chronic pancreatic cysts].

Since 1975, it has become possible to drain cysts associated with chronic pancreatitis percutaneously under sonographic guidance. Thirty-seven cysts in 35 patients have been punctured by this method. After a 23-month follow-up, 24% of the patients were considered completely healed while 35% did not present with pain again. Failure of the treatment was observed in 41% of the patients (relapse ranging from 2 days to 10 months). We observed no mortality and a 14% morbidity rate. Repetition of puncture did improve the clinical result; this latter cannot be predicted by the existence or not of a communication with the ductal system. Large cysts located in the head of the pancreas and hemorrhagic cysts relapsed systematically and must be considered a contraindication for this treatment. By contrast, primary or secondary infection of the cystic content did not appear to be predictive failure factors. This method should be used, in a first approach, for small cysts in the head of the pancreas or for cysts in the body of the tail that do not bulge into the digestive tract.

Adult↗
PubMed1993

Secretion and contribution to lipolysis of gastric and pancreatic lipases during a test meal in humans.

BACKGROUND: The aim of this study was to quantitatively evaluate the relative contributions to in vivo lipolysis of gastric and pancreatic lipases. METHODS: Gastric and pancreatic lipase secretions were measured, and their respective levels were determined in duodenal fluid during the digestion of a liquid test meal in healthy volunteers. Gastric lipase activity was clearly distinguished from that of pancreatic lipase by using both a specific enzymatic assay and an enzyme-linked immunosorbent assay. Lipolysis products were monitored throughout the digestion period. RESULTS: On a weight basis, the ratio of pancreatic lipase to gastric lipase total secretory outputs was found to be around four after 3 hours of digestion. The level of gastric hydrolysis was calculated to be 10% +/- 1% of the acyl chains released from the meal triglycerides. Gastric lipase remained active in the duodenum where it might still hydrolyze 7.5% of the triglyceride acyl chains. CONCLUSIONS: Globally during the whole digestion period, gastric lipase might hydrolyze 17.5% of the triglyceride acyl chains. In other words, gastric lipase might hydrolyze 1 acyl chain of 4, which need to be hydrolyzed for a complete intestinal absorption of monoglycerides and free fatty acids resulting from the degradation of two triglyceride molecules.

Adult↗
PubMed1993

Is bile salt-dependent lipase concentration in serum of any help in pancreatic cancer diagnosis?

The diagnostic value of bile salt-dependent lipase for pancreatic diseases was tested in sera of 187 patients. Of these patients, 76 suffered from pancreatic carcinoma, 43 from nonmalignant liver diseases (cirrhosis and chronic hepatitis), 18 from acute pancreatitis, and 20 from chronic pancreatitis. The remaining subjects were controls without pancreatic pathology. Bile salt-dependent lipase was determined by a sandwich enzyme-linked immunosorbent assay using polyclonal antibodies. Amylase and CA 19-9 antigen were also determined. In sera from control patients, the mean level of bile salt-dependent lipase was 1.5 micrograms/L. This level is quite similar to that of patients with benign liver diseases (1.1 micrograms/L) and with chronic pancreatitis (1.4 micrograms/L), but it was raised to 3.5 micrograms/L in patients with acute pancreatitis and decreased to 0.5 microgram/L in subjects with pancreatic adenocarcinoma. Thirty percent of control subjects and 73% of cancer patients had a bile salt-dependent lipase serum level below the cutoff value of 0.5 microgram/L. In acute pancreatitis, 11 of 16 subjects had levels above 1.5 micrograms/L. Amylase level largely increased in acute pancreatitis but was normal in all other groups. Concerning CA 19-9 antigen, 65% of control patients and > 80% of patients with nonmalignant pancreatic or liver diseases had normal levels. In sera from cancer patients, 80% presented with high levels. Accordingly, 36 of 38 patients with pancreatic cancer had either low serum levels of bile salt-dependent lipase (< 0.5 microgram/L) or high values of CA 19-9 antigen (> 37 U/ml; sensitivity 95%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Exocrine pancreatic secretion in normal controls and chronic calcifying pancreatitis patients from Burundi: possible dietary influences.

Pure pancreatic juice composition was studied, after secretin and cerulein stimulation in 29 people from Burundi (Central Africa): 17 controls and 12 alcoholic chronic pancreatitis (CP) patients. Results were compared to similar data in France. African controls had a similar pancreatic response to hormones apart from a much lower lipase secretion than French controls. In the early non-calcified stage of African CP water and bicarbonate secretion were markedly diminished while protein and lipase concentrations were enhanced. In the late stage, secretion was exhausted except that of calcium. Nutritional data were obtained under the same conditions in 40 African controls and in 34 CP patients (including all patients tested for secretion). African controls had a very low fat intake (35.2 +/- 2.6 g/day), and patients had a higher protein and fat intake (144.7 +/- 5.9 and 66.2 +/- 4.8 g/day, respectively) than local controls: as in other countries, CP was associated with a diet enriched in alcohol, fat and protein.

Adult↗
PubMed1993

Gastric and pancreatic lipase levels during a test meal in dogs.

The levels of gastric and pancreatic lipases in the duodenum and the jejunum were measured during the digestion of a test meal in dogs. Using both a specific enzymatic titration and an enzyme-linked immunosorbent assay, it is shown for the first time that gastric lipase remains active in the duodenal and jejunal contents. An experimental device was set up for measuring the secretions and the intestinal flows of lipases during the digestion of a liquid test meal. In a dog equipped with gastric and duodenal cannulae, the secretion of gastric lipase was stimulated by food ingestion, reaching 3.0 +/- 0.3 mg/h (three times the basal secretion rate) during the 1st h of digestion. The total secretory outputs of gastric and pancreatic lipases recorded over a 3-h period of digestion were 7.2 +/- 1.2 mg and 18.7 +/- 1.2 mg, respectively.

Animals↗
PubMed1993

[Hereditary protein lithiasis and calcium lithiasis: two different forms of hereditary pancreatitis].

We previously reported that the most frequent cases of chronic pancreatitis were the consequence of pancreatic lithiasis and that there were different forms of pancreatic lithiasis with different etiologies and composition of calculi. The most frequent form is the calcic lithiasis, generally due to nutritional disorders. The second most frequent form is proteic lithiasis. In this paper, we report 1.) Ten hereditary cases on a total of 36 patients presenting with proteic lithiasis (age at clinical onset 15 +/- 12 years); 2.) one hereditary case on a total of 150 patients with proteic lithiasis. In these two different maladies, the transmission seems to be dominant, autosomal with incomplete penetrance. Hereditary pancreatitis is therefore a group of at least two different diseases, hereditary protein lithiasis, the most frequent one and hereditary calcic lithiasis exceptional.

Adolescent↗
PubMed1992

Dog gastric lipase: stimulation of its secretion in vivo and cytolocalization in mucous pit cells.

Dog gastric lipase (DGL) secretion is stimulated in vivo by urecholine, pentagastrin, histamine, 16,16-dimethyl prostaglandin E2, and secretin. Under fasting conditions, DGL is irreversibly inactivated by gastric acid below pH 1.5; consequently, DGL output can be underestimated. This problem has been resolved by buffering the acid or by using an antisecretory drug such as omeprazole during stimulation. There is a clear parallelism between the secretion of DGL and of gastric mucus. This observation led to the present investigation of the cellular localization of DGL using immunofluorescence techniques. Results showed that DGL is cytolocalized in mucous pit cells of gastric glands. Pepsinogen is found in chief cells. To the authors' knowledge, this is the first description of an enzyme (gastric lipase) secreted by mucous-type gastric cells. In contrast to other species, gastric lipase of the dog is located in cardiac, fundic, and antral mucosae.

Animals↗
PubMed1991

Purification and biochemical characterization of dog gastric lipase.

A lipase was found to be present in dog stomach which appeared to be more abundant in the fundic than in the pyloric mucosa. Dog gastric lipase was extracted by soaking the gastric tissue and further purified after cation exchange, anion exchange and gel-filtration using fast protein liquid chromatography. The amino-acid composition, N-terminal amino-acid sequence, substrate specificity, interfacial and kinetic behavior and inactivation by sulfhydryl reagents were determined and compared with those of human and rabbit gastric lipases. We report for the first time that a gastric lipase is 13 times more active on long-chain than on short-chain triacylglycerols at pH 4.0, reaching a maximal specific activity of 950 U/mg on Intralipide emulsion.

Amino Acid Sequence↗
PubMed1991

CCK and PYY do not participate in the delayed inhibition of pancreatic secretion, after stimulation by duodenal oleic acid infusion.

The role played by CCK in the stimulation of pancreatic secretion by duodenal infusion of oleic acid in conscious rats was studied using a potent and specific CCK receptor antagonist. CR-1409 did not alter basal secretion, which does not require CCK. The three doses of CR-1409 that were used (2, 4 and 8 mg/kg/h) suppressed the protein response to duodenal infusion of oleic acid and significantly enhanced the delayed inhibition normally observed in control rats (-81%, -87% and -88% vs. -51% of basal in controls). CR-1409 dose-dependently reduced the volume of pancreatic secretion after duodenal infusion of oleic acid (0.40 +/- 0.02, 0.36 +/- 0.02, 0.34 +/- 0.03 vs. 0.48 +/- 0.04 ml/30 min for 2, 4, 8 mg/kg/h and controls, respectively) and revealed a delayed inhibition of volume and a slight reduction of bicarbonate secretion. CCK appears to be directly responsible for the protein and also water response to duodenal infusion of oleic acid, and to be indirectly involved in bicarbonate stimulation. PYY antiserum significantly augmented protein output after duodenal infusion of oleic acid (10.75 +/- 1.40, 14.10 +/- 1.60 vs. 8.60 +/- 1.20 mg/30 min, 1 microliter, 2 microliters and controls), but failed to modify the delayed inhibition: PYY modulates the response to duodenal infusion of oleic acid and is not involved in the delayed inhibition, which was shown to be also present for volume, but which is normally masked by the action of CCK.

Animals↗
PubMed1991

Effects of zinc and copper deficiency associated with protein or lipid deficiency on rat exocrine pancreatic secretion.

Copper and zinc are both secreted by the pancreas but are necessary for pancreatic secretion. We have studied the effects of a 4- or 8-week zinc or copper-deficient diet associated with or without lipid or protein deficiency on rat pancreatic secretion after stimulation by secretin, cerulein, or intraduodenal oleic acid. Twenty animals were in the control group; 40 rats were fed a copper-deficient diet (20 copper-deficient only and 20 copper- plus lipid-deficient). Ninety rats were deprived of zinc (30 of zinc-deficient only, 30 zinc-plus protein-deficient, 30 of zinc- plus lipid-deficient). Only the zinc- plus lipid-deficient diet for 8 weeks decreased basal bicarbonate and basal protein secretion (-42 and -70%, respectively, of the control values). Stimulated secretion was not markedly altered by copper deficiency while zinc deficiency, zinc plus protein deficiencies, and zinc plus lipid deficiencies suppressed almost responses to hormonal stimulation: After 8 weeks, the maximal protein response to oleic acid was reduced to 19.00 +/- 3.40, 18.58 +/- 3.00, and 12.04 +/- 2.91 microgram/30 min/g body weight in zinc- zinc and protein-; and zinc- and lipid-deficient diet, respectively, versus 39.87 +/- 6.33 microgram/30 min/g body weight (p less than 0.05) in controls. In all types of stimulation, lipid deficiency potentiated the deleterious effect of zinc deficiency on pancreatic secretion. This might be paralled with an extremely low level of lipid in the diet of people living in countries in which nutritional pancreatitis is observed and with the relative risk of developing an alcoholic chronic pancreatitis being increased by a low fat diet.

Animals↗
PubMed1991

Changes in pancreatic exocrine secretion with age: pancreatic exocrine secretion does decrease in the elderly.

Pancreatic exocrine secretion was estimated in 180 normal control patients, free of abdominal and pancreatic disease, aged from 16 to 83 years. Duodenal juice was collected in two 15-min fractions after a single intravenous injection of 1 U/kg secretin + 3 U/kg CCK. Volume, maximal concentration and output of bicarbonate, lipase, phospholipase and chymotrypsin were estimated as well as minimal concentration and output of chloride and calcium. Each parameter was plotted against age, either individually or after separation into two age groups. Volume linearly increased up to the 3rd decade, and thereafter linearly decreased. Bicarbonate secretion paralleled fluid secretion and also decreased after the 3rd decade. The changes in chloride and calcium concentrations were different: concentrations linearly increased after the 3rd decade. Calcium concentration linearly increased with age (p less than 0.02) while chloride output was unchanged. The three enzymes that were studied linearly decreased in concentration as well as in output with age from the 3rd decade (p less than 0.02). Protein secretion decreased before water and bicarbonate secretion. One can conclude that pancreatic secretion changes in humans with age. Aging alters pancreatic secretion, through a decrease in flow rate, bicarbonate and enzyme secretion while calcium concentration is enhanced. Although not requiring substitutive therapy in the whole population, individual cases of pancreatic exocrine insufficiency might be explained by aging, without malnutrition.

Adult↗
PubMed1989

Immunocytolocalization of human gastric lipase in chief cells of the fundic mucosa.

The presence in human gastric juice of a lipase secreted by the gastric mucosae has been reported previously, but its exact cellular origin has not yet been established. Polyclonal antibodies specific to human gastric lipase (HGL) were prepared, and used by an immunofluorescence technique to label cells producing HGL. This immunocytolocalization was correlated with that of pepsin (chief cells) and parietal cells using specific polyclonal or monoclonal antibodies. Our results clearly establish that HGL is exclusively located in the chief cells of fundic mucosa; furthermore, it was found to be always co-located with pepsin. No HGL was observed in the parietal or mucus cells. HGL was always detected intracellularly, either in secretory granules of the apical region of the chief cells, or revealed by more diffuse cytoplasmic labelling.

Antibodies↗
PubMed1988

Human preduodenal lipase is entirely of gastric fundic origin.

Lipase activity was measured in supernatant homogenates from various anatomic regions in the upper part of the human digestive tract of two organ donors. It is shown unambiguously that lipase activity occurs only in the fundic mucosa of the stomach, whereas no significant activity takes place in the antral, pharyngeal, or lingual areas, including the circumvallate papillae. In adults, the potential activity of human gastric lipase, as measured using tributyrin as substrate, amounts to 20% of its pancreatic counterpart. Lipase activity was also determined on human gastric biopsy samples taken during gastrofibroscopy tests on healthy adults. These results confirmed the finding that a lipolytic activity of gastric origin occurs uniformly and only in the fundic mucosa. Triacylglycerol hydrolysis is associated with a genuine gastric lipase activity that is clearly distinct from the classical esterase observed using p-nitrophenyl acetate as substrate. Lipase activity decreases significantly with age: it ranges on average from 4700 U/g of fresh mucosa in subjects aged up to 50 yr to 700 U/g of fresh mucosa in persons over 60 yr of age.

Adult↗
PubMed1988

Chronic obstructive pancreatitis due to tiny (0.6 to 8 mm) benign tumors obstructing pancreatic ducts: report of three cases.

Three cases of obstructive pancreatitis are described in nonalcoholic women aged 56 to 58 years with a 2-month to 5-year history of recurrent attacks of pancreatic pain associated with intermittent raised serum pancreatic enzymes. The diagnosis was made by sonography showing an enlarged hyperechogenic tail of the pancreas, with a dilated duct, the rest of the pancreas being normal, and by ERCP showing a partial stenosis of the main pancreatic duct with regular dilatation of collateral branches distally to it. Surgical resection of the pancreatic tail cured all three patients. In the obstructed part of the pancreas, the lesions are typical of obstructive pancreatitis with perilobular and sometimes intralobular fibrosis of the same degree in the different lobules of the diseased area and not patchy as in chronic calcifying pancreatitis. The changes in collateral ducts are not marked, and there is an absence of intraductal plugs. Fat necrosis and pseudocysts may be found. Tumors responsible for the obstruction were the smallest islet cell tumors (0.6 and 8 mm) and serous cystadenoma (5 mm) responsible for symptoms ever published. Cephalad to the stricture, the pancreas was normal. When the etiology of chronic pancreatitis is atypical, especially when it occurs in nonalcoholic women aged greater than 50 years, a careful sonography (or computed tomographic scan) and ERCP must be done. Serial sections of the resected pancreas at the level of the obstruction and distal to it are often necessary to demonstrate the tumor.

Adenoma, Islet Cell↗