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Biomedical subjects

O Olsen

Publications and source records attributed to O Olsen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Cephalic phase of lipolysis is impaired in pancreatic insufficiency: role of gastric lipase.

BACKGROUND: Gastric lipase contributes significantly to overall lipolysis and is regulated by interacting neuro-hormonal mechanisms. Patients with alcoholic chronic pancreatitis (ACP) have low, or even absent, activity of pancreatic lipases. In that state the secretion of gastric lipase could be essential and compensate for the pancreatic defect. However, conflicting studies have not resolved the order of magnitude of gastric lipase secretion in these patients. This could be explained by differences in regulatory mechanisms, gastric mucosal changes, and abdominal vagal tone. METHODS: Nasogastric intubation with modified sham feeding and upper endoscopy including biopsies for histologic classification and Helicobacter pylori infection status were performed in eight ACP patients, and eight healthy volunteers were studied on separate occasions. Vagal nerve function was assessed by calculation of heart rate variability in ACP patients. Gastric lipase was measured in aspirates by means of enzyme-linked immunosorbent assay and an enzyme kinetic assay. Plasma concentrations of gastrin, secretin, cholecystokinin, and pancreatic polypeptide were measured throughout the study. RESULTS: Sham feeding rapidly and significantly increased gastric lipase secretion in healthy volunteers, whereas ACP patients did not respond to sham feeding. Two of eight patients were infected with H. pylori and had mucosal changes accordingly. The lack of lipase response could not be ascribed to dysfunction of the abdominal vagus. CONCLUSIONS: The cephalic phase of gastric lipase secretion is impaired in ACP patients. Although their fundic cells continue to secrete gastric lipase, they are not subject to normal neuro-hormonal regulation.

Adult↗
PubMed2000

The influence of potato fibre on exocrine pancreatic secretions and on plasma levels of insulin, secretin and cholecystokinin in growing pigs.

The effect of a potato fibre preparation on exocrine pancreatic secretions and on gastrointestinal hormone levels in plasma was studied in three 8 weeks old piglets that were surgically fitted with a jugular vein catheter for blood sampling, a pancreatic duct catheter and a T-shaped duodenal cannula for collection of pancreatic juice. The animals were fed for 2 weeks a control diet (experimental period 1), thereafter for 2 weeks the control diet supplemented with 2% potato fibre (experimental period 2) and for another 2 weeks the control diet again (experimental period 3). Additionally, intraduodenal (i.d.) infusions of the experimental diet, the control diet and potato fibre as well as i.v. infusions of a solution containing cholecystokinin (CCK) and secretin were administered. Potato fibre in the diet evoked in tendency an increase in the volume of secretion of pancreatic juice and a significant increase both in the mean values of the total protein content and total activities of lipase, trypsin and alpha-amylase when compared to the control diet. The i.d. infusion of the control diet, experimental diet and fibre infusate as well as the i.v. administration of the hormone infusate led to a spontaneous secretory response of the exocrine pancreas. Besides gastrointestinal hormones, such as CCK, other factors such as short chain fatty acids may be involved in the regulation of the exocrine pancreas.

Animals↗
PubMed1999

Inhibition of human gastric lipase by intraduodenal fat involves glucagon-like peptide-1 and cholecystokinin.

Seven healthy volunteers were intubated with two double lumen nasogastric tubes, one in the stomach, the other in the duodenum. This system allows simultaneous sampling of gastric juice and separate intraduodenal perfusion with a dietary fat (fish oil, 1269 kJ). Gastrin-17 was infused i.v. at a rate of 40 pmol/kg/h throughout the study. Gastric lipase was measured at 15-min intervals as activity (tributyrin) and as immunoreactivity (ELISA). Infusion of gastrin-17 resulted in a stable increase in the plasma concentration from a basal concentration of 8.3 +/- 0.8 pmol/l to 41.4 +/- 4.2 pmol/l. Perfusion with fat reduced gastric lipase activity from 24.2 +/- 5.3 to 7.2 +/- 2.5 kU/l (P < 0.05), and immunoreactivity from 0.7 +/- 0.1 to 0.42 +/- 0.1 mg/l (P < 0.05). After termination of fat perfusion, gastric lipase secretion increased again, though not reaching preinhibitory concentrations. During the intraduodenal perfusion with fat the plasma concentrations of glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) increased from 6.9 +/- 0.5 to 15.1 +/- 1.5 pmol/l (P < 0.05) and from 1.2 +/- 0.4 to 3.8 +/- 0.9 pmol/l (P < 0.05). This study reveals a negative effect of fat in the duodenum on gastric lipase secretion. This effect may be mediated by GLP-1 and/or CCK.

Adult↗
PubMed1999

[Gallstones and pancreatic necrosis in acute pancreatitis].

The purpose of this study was to investigate the occurrence of gallstones and the severity of acute pancreatitis in a Danish population, and in severe cases, the relation between pancreatic necrosis and gallstones. We used Ranson's prognostic scoring system to measure the severity of acute pancreatitis, ultrasonography for detecting biliary stones, and computed tomography or laparotomy for detecting pancreatic necrosis. During a two year period, we registered 101 patients. Approximately 70% were mild cases, and we found 18 patients with and 53 patients without gallstones. Among patients with severe cases, we observed 14 with and 16 without gallstones. There was a significantly higher proportion of gallstones in severe cases. Eight of 30 patients with severe pancreatitis had pancreatic necrosis, but we found no relation between the occurrence of necrosis and gallstones. We conclude that patients with gallstone related pancreatitis have more severe disease than patients without stones, but the complication of pancreatic necrosis is not related to gallstones.

Acute Disease↗
PubMed1999

Fish oil reduces gastric acid secretion.

BACKGROUND: The aim of the present investigation was to study gastric acid secretion and release of gastrin, cholecystokinin (CCK), and secretin during intraduodenal perfusion of either fish oil or trioleate. METHODS: Seven healthy volunteers were stimulated on two separate days in random order with intraduodenal perfusates of either fish oil or trioleate. RESULTS: Intravenous infusion with gastrin-17 was used as a background stimulation in doses mimicking a postprandial situation (39.9 +/- 4.8 pmol/l fish oil and 43.6 +/- 3.8 pmol/l trioleate). Gastric acid secretion increased significantly from a basal level of 0.7 +/- 0.1 meq/15 min to 4.0 +/- 0.6 meq/15 min (P < 0.05) before perfusion of fish oil, which reduced gastric acid secretion to 1.9 +/- 0.4 meq/15 min (P < 0.01). After termination of fish oil perfusion gastric acid secretion increased to preperfusion concentrations (P < 0.01). Perfusion of trioleate did not influence gastric acid secretion. Plasma concentrations of CCK rose significantly during perfusion of fish oil (from 2.8 +/- 0.6 pmol/l to 4.4 +/- 0.7pmol/l, P<0.01), whereas trioleate only tended to increase CCK concentrations. Plasma concentrations of secretin did not change during perfusion of fish oil; however, concentrations were significantly lower during and after perfusion of trioleate (P < 0.01). CONCLUSION: The present study shows that intraduodenal perfusion of fish oil is associated with a significant reduction of the gastric acid secretion stimulated by gastrin in healthy humans.

Adult↗
PubMed1999

Fat and mesenteric blood flow.

BACKGROUND: The introduction of fat to the duodenum leads to an increase in mesenteric blood flow. The exact mechanism, however, is unknown. In this study we investigate the influence of the terminal carboxy group of the oleic acid molecule on superior mesenteric artery blood flow. METHODS: In six healthy male volunteers duplex ultrasound was used to evaluate the effects of duodenal perfusion of 48 mmol oleic acid and 48 mmol oleyl alcohol on superior mesenteric artery blood flow variables and diameter. RESULTS: The blood flow variables time-average velocity and maximal diastolic velocity increased significantly, and the resistance index decreased significantly during perfusion with oleic acid, but during oleyl alcohol perfusion no changes were found. No significant changes in vessel diameter were observed at any time. CONCLUSION: The carboxy group of the oleic acid molecule has an important role in the duodenum in mediating the postprandial increase in superior mesenteric artery blood flow.

Adult↗
PubMed1999

Dentist reliability in classifying disease risk and reason for treatment.

OBJECTIVES: The reliability of practicing dentists' classifications of patients' caries risk and periodontal disease risk and reason for treatment for individual teeth were determined. The risk classification protocols had been in use in a group practice for more than a year, and the reason-for-treatment protocol had been introduced six months previously. METHODS: Eight dentists' classifications for caries (n = 66) and periodontal disease risk (n = 66), and six dentists' classifications for reason for treatment (n = 73) were compared to those of a nominal standard examiner. Reliability was expressed as percent agreement and kappa values. RESULTS: Percent agreement was 76 percent, 83 percent, and 74 percent for caries, periodontal disease, and reason for treatment, respectively, with kappa values of 0.56, 0.70, and 0.69. CONCLUSIONS: Dentists can attain reasonable levels of reliability using simple classification protocols with little formal training, although misclassification may be problematic for specific administrative or research-related purposes.

Decision Making↗
PubMed1999

Effects of maternal education on infant mortality and stillbirths in Denmark.

This study examined inequalities in infant mortality in Denmark in relation to maternal educational level, and compared the inequalities to those observed in a similar study 10 years earlier. It was a register-based study of all singleton births in Denmark 1991-92, a study population of 113,814 births. When adjusted for mother's age, parity, and smoking, the stillbirth rate was independent of mother's educational level, but a clear social gradient in infant mortality was observed. Compared with a similar study in 1982-83, infant mortality has decreased most in the highest educational group and has increased in the lowest educational group. In conclusion, social inequality in infant mortality in Denmark is pronounced and cannot be explained by differences in smoking habits. The social gap between different educational groups has widened during the last decade, but may partly be explained by the decreasing number of women in the lowest educational group.

Adolescent↗
PubMed1998

[Determination of the expected day of delivery--ultrasound has not been shown to be more accurate than the calendar method].

It has been claimed that the expected day of delivery (EDD) determined on the basis of an ultrasound scan is more accurate than using a calendar method. The aim of this paper is to assess the evidence in support of this claim. A critical review of the methodologically best research revealed that among women with regular cycles and know first day of the last menstrual period, Naegele's rule predicted the EDD to be 3.3 days too early, on average, whereas prediction based on ultrasound scans was 2.0 days too late. The standard deviations of the two distributions were the same. After correction for the systematic biases, the two methods of prediction were thus equally precise. It is concluded that the EDD should be calculated by adding 283 days to the date of the last period rather than by adding 280 days. For women with regular cycles and known first day of the last menstrual period, ultrasound dating does not lead to a more precise prediction.

Delivery, Obstetric↗
PubMed1998

Inhibition of human gastric lipase secretion by glucagon-like peptide-1.

Glucagon-like peptide-1 (GLP-1) may be one of the enterogastrone hormones of the ileal brake mechanism. We therefore studied its effects on gastric lipase secretion in healthy volunteers and vagotomized patients during infusion of pentagastrin. The intestinal incretin hormone GLP-1 (glucagon-like peptide-1, 7-36 amide) was investigated because of its inhibitory effects on gastric acid secretion and motility. GLP-1 infused intravenously in amounts corresponding to the postprandial release significantly inhibited pentagastrin-stimulated gastric lipase secretion and lipolytic activity. The inhibitory effect of GLP-1 persisted in vagotomized patients, suggesting that fundic chief cells, from which gastric lipase is released, or neighboring inhibitory cells could be equipped with GLP-1 receptors. Vagotomized patients had significantly higher plasma concentrations of gastrin and secretin. No significant changes of gastrin, secretin, and CCK secretion were seen during GLP-1 infusion in the vagotomized patients, whereas secretin decreased significantly in the healthy volunteers. GLP-1 seems to be a naturally occurring inhibitor of gastric lipase secretion acting via a nonvagal mechanism. Our results indicate that gastric lipase secretion is subject to hormonal stimulatory as well as inhibitory mechanisms.

Aged↗
PubMed1998

Regulation of porcine biliary secretion by secretin.

The importance of physiological plasma levels of secretin in biliary bicarbonate secretion is not known. However, in anaesthetized pigs the substantial hepatic output of bicarbonate into the duodenum in response to low doses of secretin exceeds pancreatic bicarbonate output. The aim was therefore to study the relationship between duodenal acidification, secretin and hepatic biliary bicarbonate output in the conscious pig. Göttingen minipigs (n = 22) were cholecystectomized and the common bile duct catheterized. The biliary bicarbonate secretion in response to intraduodenal HCl, secretin or pentagastrin given intravenously, and to meal was studied. Intraduodenal HCl infusion, secretin and pentagastrin given intravenously augmented hepatic bicarbonate output and plasma secretin concentrations significantly. The secretin response to acidification was sufficient to explain the subsequent increase in biliary bicarbonate secretion. Hepatic bicarbonate secretion and concentrations of CCK and secretin in plasma increased postprandially. Exclusion of bile salts from the duodenum abolished postprandial increase in bile volume and increased release of CCK in fasting and fed pigs whereas secretin release was diminished. The results demonstrate that hepatic bicarbonate secretion is stimulated by endogenous secretin and therefore may have a physiological role in duodenal neutralization.

Animals↗
PubMed1998

Effect of sham feeding and acute suppression of acid secretion on human gastric lipase secretion.

OBJECTIVE: Gastric lipase and gastric acid are secreted simultaneously. The aim of this study was to investigate whether the acid interferes with the lipase secretion. The secretion of human gastric lipase was studied during blockade of gastric acid secretion and modified sham feeding to estimate the impact of these conditions on both gastric lipase enzyme activity and immunoreactivity. METHODS: Eight healthy volunteers were intubated with a nasogastric tube. We examined gastric aspirates for the amount and activity of lipase secretion during basal conditions, after blockade of acid secretion with a proton pump inhibitor (omeprazole iv. infusion), and in response to sham feeding (chewing gum) during the blockade. RESULTS: The amount of secreted gastric lipase was unaffected by blockade of acid secretion and increased significantly after sham feeding (169.9+/-35.7 microg/15 min to 348.1+/-79.2 microg/15 min; p < 0.01). Likewise, the output of enzyme activity increased after sham feeding (0.63+/-0.09 kU/15 min to 1.52+/-0.36 kU/15 min; p < 0.03). The concentration of enzyme activity remained unchanged by blockade of acid secretion, whereas the output of enzyme activity was decreased, probably because of reduced volume secretion or denaturation and conformational changes of the enzyme. Plasma concentrations of gastrin increased in response to blockade of acid secretion (basal 9.6+/-1.4 pmol/L to 13.3+/-2.9 pmol/L; p < 0.02). CONCLUSIONS: Gastric acid secretion is not a prerequisite for gastric lipase secretion. Lipase enzyme activity, though, is sensitive to anacidic conditions.

Adult↗
PubMed1997

Basolateral membrane targeting of a renal-epithelial inwardly rectifying potassium channel from the cortical collecting duct, CCD-IRK3, in MDCK cells.

We recently cloned an inward-rectifying K channel (Kir) cDNA, CCD-IRK3 (mKir 2.3), from a cortical collecting duct (CCD) cell line. Although this recombinant channel shares many functional properties with the "small-conductance" basolateral membrane Kir channel in the CCD, its precise subcellular localization has been difficult to elucidate by conventional immunocytochemistry. To circumvent this problem, we studied the targeting of several different epitope-tagged CCD-IRK3 in a polarized renal epithelial cell line. Either the 11-amino acid span of the vesicular stomatitis virus (VSV) G glycoprotein (P5D4 epitope) or a 6-amino acid epitope of the bovine papilloma virus capsid protein (AU1) was genetically engineered on the extreme N terminus of CCD-IRK3. As determined by patch-clamp and two-microelectrode voltage-clamp analyses in Xenopus oocytes, neither tag affected channel function; no differences in cation selectivity, barium block, single channel conductance, or open probability could be distinguished between the wild-type and the tagged constructs. MDCK cells were transfected with tagged CCD-IRK3, and several stable clonal cell lines were generated by neomycin-resistance selection. Immunoprecipitation studies with anti-P5D4 or anti-AU1 antibodies readily detected the predicted-size 50-kDa protein in the transfected cells lines but not in wild-type or vector-only (PcB6) transfected MDCK cells. As visualized by indirect immunofluorescence and confocal microscopy, both the tagged CCD-IRK3 forms were exclusively detected on the basolateral membrane. To assure that the VSV G tag was not responsible for the targeting, the P5D4 epitope modified by a site-directed mutagenesis (Y2F) to remove a potential basolateral targeting signal contained in this tag. VSV(Y2F) was also detected exclusively on the basolateral membrane, confirming bona fide IRK3 basolateral expression. These observations, with our functional studies, suggest that CCD-IRK3 may encode the small-conductance CCD basolateral K channel.

Amino Acid Sequence↗