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Biomedical subjects

A A Masclee

Publications and source records attributed to A A Masclee.

At least 127 records · Page 7Linked to original sources
PubMed1993

Bombesin reduces food intake in lean man by a cholecystokinin-independent mechanism.

This double blind study was undertaken to determine whether infusion of bombesin (BBS) inhibits the intake of a carbohydrate-rich meal in nine lean healthy subjects and whether inhibition of food intake by BBS is mediated by cholecystokinin (CCK). During infusion of BBS, the amount of food eaten was decreased compared to that after saline infusion (482 +/- 74 vs. 602 +/- 68 g; P < 0.01). Subjective criteria of satiation were also significantly affected by BBS infusion (P < 0.05). Administration of the CCK receptor antagonist loxiglumide (CR1505) to six of the subjects did not prevent the decrease in food intake due to BBS (365 +/- 69 g) or the subjective criteria for satiety. Furthermore, the amount of food eaten during loxiglumide treatment alone (537 +/- 109 g) was not different from that during control saline infusion. In conclusion, infusion of BBS inhibits the intake of a carbohydrate-rich meal by a CCK-independent mechanism.

Adult↗
PubMed1993

Initial experience with laparoscopic fundoplication in The Netherlands and comparison with an established technique (Belsey Mark IV).

Since the introduction of laparoscopic cholecystectomy as an alternative for conventional cholecystectomy, the number of cholecystectomies per year is showing an increased tendency, suggesting that indications for surgery have broadened now that the morbidity of the procedure has decreased so much. For gastro-oesophageal reflux disease (GORD) the current number of operations performed per year in The Netherlands is small compared with the calculated prevalence of complicated GORD. If the data on epidemiology of GORD by Richter are extrapolated to the population of The Netherlands, there must be at least 4,500 potential candidates for antireflux surgery currently available and only 250 operations are performed per year. Laparoscopic Nissen fundoplication is practised with acceptable results. If with this new development the same tendency as for laparoscopic cholecystectomy arises, this may mean either that too many patients will undergo antireflux surgery or that the potential candidates will now get their chance to have an effective operation with the prospect of low procedure-related morbidity. In The Netherlands, 62 laparoscopic Nissen fundoplications have been performed. There have been no deaths and in 5 patients the laparoscopic procedure had to be converted into a laparotomy. Forty-two of these 62 patients were treated according to a protocol and were included in the follow-up. At one month, 38 out of 42 patients were available for follow-up. At one month after surgery, 38 patients felt that their reflux symptoms had improved. Surgery-induced symptoms were present in 19 out of 38 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Gastrointestinal disturbances with obesity.

Steatosis and steatohepatitis are associated with obesity. Despite florid histological changes, patients with non-alcoholic steatohepatitis generally remain asymptomatic, and it usually runs a relatively benign course. An elevated insulin level may be important in the pathogenesis. There is a marked regression of fatty changes after weight reduction. In obese subjects the risk of developing gallstones is increased due to an increased saturation of gallbladder bile with cholesterol and possible gallbladder stasis. During weight reduction with very low calorie diets the incidence in gallstones increases probably because of an increased saturation of bile during the loss of weight. Ursodeoxycholic acid appears to be a promising prophylactic agent. Chenodeoxycholic acid is not useful for these subjects. There is controversy over whether obesity contributes to gastroesophageal reflux and gastric emptying disturbances. There are changes in gastrointestinal peptide plasma levels in obesity but it is not clear if this contributes to its development. The risk for high-risk colorectal adenomas and carcinomas is reported to be increased in obese males. Vertical banded gastroplasty and gastric bypass procedures are nowadays the surgical options for the treatment of obesity. Nutritional deficiencies, particularly of vitamin B12, folate and iron are common after gastric bypass and must be sought and treated. Dumping is another potential complication of this operation. If stenosis and gastric outlet obstruction develop endoscopic dilatation is a good therapeutic option.

Animals↗
PubMed1992

Effect of loxiglumide and atropine on erythromycin-induced reduction in gallbladder volume in human subjects.

This study was undertaken to investigate the effect of erythromycin, a motilin agonist with prokinetic activity, on fasting gallbladder volume. To evaluate the mechanism of action of erythromycin on gallbladder motility, erythromycin (3.5 mg/kg.20 min, intravenously) was infused on three separate occasions: during cholinergic blockage with atropine (0.005 mg/kg.hr), during cholecystokinin receptor blockade with loxiglumide (10 mg/kg.hr) and during saline solution infusion (control). Atropine, loxiglumide and saline solution infusions were started 3 hr before administration of erythromycin and were continued for 3 hr thereafter. Gallbladder volumes (measured by ultrasonography), plasma cholecystokinin levels (radioimmunoassay) and plasma pancreatic polypeptide levels (radioimmunoassay) were determined at regular intervals for 6 hr in six healthy volunteers. During the 3-hr infusion before administration of erythromycin, both loxiglumide and atropine significantly increased gallbladder volumes--from 18 +/- 2 to 37 +/- 3 cm3 (p less than 0.05) and from 17 +/- 3 to 24 +/- 2 cm3 (p less than 0.05), respectively--whereas saline solution did not significantly affect gallbladder volume. During control saline solution infusion, erythromycin induced prolonged gallbladder contraction that was significant (p less than 0.05) between 60 and 180 min and reached a maximum of 45% +/- 8% at 150 min. Plasma cholecystokinin levels were not affected by erythromycin. Erythromycin induced a significant (p less than 0.05) increase in plasma pancreatic polypeptide levels, from 12 +/- 1 pmol/L to 34 +/- 3 pmol/L. Loxiglumide did not prevent the erythromycin-induced reduction in gallbladder volume. Atropine markedly reduced the effect of erythromycin, causing slight but significant (p less than 0.05) gallbladder volume reductions (18% +/- 4%) between 150 and 180 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effect of acute hyperglycemia on esophageal motility and lower esophageal sphincter pressure in humans.

The effect of acute hyperglycemia on esophageal motility and lower esophageal sphincter pressure (LESP) was investigated. Esophageal manometry was performed for 120 minutes in seven healthy volunteers on two separate occasions during euglycemia and during hyperglycemia with blood glucose levels stabilized at 15 mmol/L. At 90 minutes, motility was stimulated with edrophonium chloride (0.08 mg/kg intravenously). Pancreatic polypeptide (PP) secretion was determined as an indirect measure of vagal-cholinergic tone. During hyperglycemia the LESP decreased significantly (P less than 0.05) from 20.1 +/- 1.6 mm Hg to 10.7 +/- 0.6 mm Hg; plasma PP levels were also significantly (P less than 0.05) decreased during hyperglycemia. Edrophonium induced significant (P less than 0.05) increases in LESP and PP levels in both experiments. However, LESP and PP levels after edrophonium stimulation remained significantly (P less than 0.05) reduced during hyperglycemia compared with euglycemia. During hyperglycemia a significant (P less than 0.05) increase in peristaltic wave duration and a decrease in peristaltic velocity were observed in the distal part of the esophagus. It is concluded that blood glucose levels affect esophageal motility, acute hyperglycemia reduces LESP and impairs esophageal motility under both basal and edrophonium-stimulated conditions, and hyperglycemia reduces plasma PP levels, suggesting impaired vagal-cholinergic activity during hyperglycemia.

Acute Disease↗
PubMed1992

Effect of hyperglycemia on gastrointestinal and gallbladder motility.

Gastrointestinal motor abnormalities occur frequently in patients with diabetes mellitus. The gastrointestinal motor dysfunction in these patients has been associated with the presence of autonomic neuropathy. Recently, however, several studies have shown that the gastrointestinal motor responses to various stimuli are impaired during acute hyperglycemia in both healthy subjects and diabetic patients. It has been demonstrated that acute hyperglycemia impairs esophageal peristalsis, reduces the lower esophageal sphincter pressure, delays gastric emptying, slows intestinal transit, and reduces the gallbladder contraction in response to various stimuli in healthy subjects. In diabetic patients gastric emptying and gallbladder contraction have been shown to be impaired during hyperglycemia. With regard to the mechanisms of action, it has been suggested that hyperglycemia may affect gastrointestinal function through vagal-cholinergic inhibition, by alterations in serum osmolality, or perhaps by alterations in gastrointestinal hormone secretion.

Diabetes Mellitus↗
PubMed1992

Gallbladder disease in cystic fibrosis.

Among the various gastrointestinal manifestations observed in patients with cystic fibrosis (CF), gallbladder abnormalities occur frequently. These include a high prevalence of nonfunctioning gallbladders (30%), micro-gallbladders (8-30%), and gallstones (4-30%). The underlying pathophysiology for this increased prevalence in patients with CF is not completely understood, due to contradictory findings. These findings concern: (1) abnormalities in bile acid metabolism resulting in bile that is supersaturated with cholesterol, (2) an impaired nucleation time, and (3) biliary stasis, due to bile duct abnormalities and/or impaired gallbladder motility. The diagnosis of gallbladder disease in CF may be obscured by other common gastrointestinal complications, resulting in a long delay between onset of symptoms and the diagnosis. Cholecystectomy in CF is the treatment of choice, provided they are carefully managed in the pre- and perioperative period. The operative morbidity and mortality, even with intensive management of pulmonary disease, amounted to 10% and 5%, respectively. Therefore, alternative options, like laparoscopic cholecystectomy are of interest and require further investigation, especially for CF patients with severe pulmonary disease.

Cholecystectomy↗
PubMed1991

Intravenous administration of bombesin in man stimulates natural killer cell activity against tumour cells.

Peptides from both the nervous and endocrine system have been shown to influence immune functions. This study describes the stimulatory effect of bombesin on natural killer cell activity of peripheral blood mononuclear cells. The stimulation of cytotoxicity by bombesin in vivo was much higher than found in vitro. In vitro studies with bombesin and gastrin revealed that the stimulatory effect of bombesin in vivo can for a major part be attributed to other stimulatory mediators which are released by BBS. These results indicate that neuropeptide release might rapidly interfere, both directly and indirectly, with natural killer activity of peripheral blood mononuclear cells.

Adult↗
PubMed1991

Gallbladder sensitivity to cholecystokinin in coeliac disease. Correlation of gallbladder contraction with plasma cholecystokinin-like immunoreactivity during infusion of cerulein.

The present study was undertaken to determine whether alterations in the gallbladder sensitivity to cholecystokinin (CCK), apart from a reduced endogenous CCK secretion, contribute to the abnormally decreased postprandial gallbladder contraction in patients with coeliac disease. Gallbladder emptying, measured by cholescintigraphy, and plasma CCK levels, measured by radioimmunoassay, were studied during infusion of graded doses of the CCK analog cerulein in six coeliac patients with subtotal villous atrophy, six coeliac patients on a gluten-free diet with normal villous architecture, and nine control subjects. Both in the patients and in the controls infusion of stepwise increasing doses of cerulein, in the range of 1-16 ng.kg-1.h-1, induced dose-related changes in plasma CCK-like immunoreactivity (CCK-LI) (r = 0.99; p less than 0.001) and gallbladder emptying (r greater than 0.97; p less than 0.01-p less than 0.001). Plasma CCK-LI and gallbladder responses were not significantly different among untreated coeliac patients, treated coeliac patients, and controls. Gallbladder sensitivity to cerulein in untreated and treated coeliac patients was not significantly different from that in controls. It is concluded that the abnormally decreased gallbladder contraction in coeliac patients is the result of a reduced endogenous CCK secretion and not of a lack of end-organ responsiveness to CCK.

Celiac Disease↗
PubMed1990

Effect of truncal vagotomy on cholecystokinin release, gallbladder contraction, and gallbladder sensitivity to cholecystokinin in humans.

The present study was undertaken to investigate the gastric and intestinal phase of stimulation of postprandial gallbladder contraction and endogenous cholecystokinin secretion in patients with truncal vagotomy and pyloroplasty. Gallbladder emptying, measured by cholescintigraphy, and endogenous cholecystokinin secretion, measured by radioimmunoassay, were studied after both intragastric and intraduodenal administration of corn oil. In addition, the gallbladder responsiveness to cholecystokinin was investigated by infusion of stepwise increasing doses of exogenous cholecystokinin. In the 6 patients with truncal vagotomy, plasma CCK and gallbladder responses to intraduodenal fat were significantly delayed compared to normal subjects. In contrast, the onset of the plasma cholecystokinin increase and gallbladder emptying after intragastric fat was significantly earlier in the vagotomized patients compared with the normal subjects. In the normal subjects, plasma cholecystokinin and gallbladder responses to intragastric fat were significantly lower during the first 25 min after stimulation compared with the results after intraduodenal fat, whereas in the patients with truncal vagotomy and pyloroplasty, no differences in plasma cholecystokinin and gallbladder responses were found according to the site of fat stimulation. The gallbladder-emptying response to exogenous cholecystokinin increased significantly in patients who had undergone truncal vagotomy. It is concluded (a) that truncal vagotomy with pyloroplasty influences the timing but not the magnitude of fat-stimulated gallbladder contraction and endogenous cholecystokinin secretion; and (b) that the sensitivity of the gallbladder to endogenous and exogenous cholecystokinin is significantly increased in patients with truncal vagotomy.

Adult↗
PubMed1990

Lack of effect of the specific cholecystokinin receptor antagonist loxiglumide on cholecystokinin clearance from plasma in man.

Saline or loxiglumide (2.5 mg kg-1 in 10 min, followed by 5 mg kg-1 h-1 for 200 min) was administered intravenously in random order to six healthy subjects. After 60 min cholecystokinin (CCK-33) was infused (0.5 i.d.u. kg-1 h-1 for 1 h then 1.0 i.d.u. kg-1 h-1 for 1 h). Loxiglumide did not change basal levels of CCK and did not augment plasma CCK-immunoreactivity during CCK-33 infusion. After cessation of the CCK-infusion, plasma CCK concentrations decreased rapidly to basal values within 12 min, and the elimination half-life during loxiglumide infusion (4.8 +/- 0.8 min) was not significantly different from that during saline infusion (4.2 +/- 1.0 min). These results suggest that loxiglumide does not interfere with the distribution and metabolism of CCK.

Adult↗
PubMed1990

Ambulatory 24-hour pH-metry in the diagnosis of gastroesophageal reflux disease. Determination of criteria and relation to endoscopy.

The results of ambulatory 24-h esophageal pH monitoring in 67 patients with gastroesophageal reflux symptoms (endoscopic esophagitis, n = 44; normal endoscopy, n = 23) were compared with those of 27 normal subjects without reflux symptoms. Patients with reflux symptoms had significantly increased gastroesophageal reflux compared with normal subjects. Acid reflux time was significantly (p less than 0.001) correlated with the severity of endoscopic esophagitis. Linear discriminant analysis was used to differentiate, for each reflux variable, between patients and controls. When the percentage of overall time at pH below 4 was used as a single determinant of gastroesophageal reflux, the sensitivity and specificity were 81% and 85%, respectively, with 4% as upper limit of normal. Pathologic reflux was found in 61% of the patients with negative endoscopy. Long-term ambulatory pH-metry is of clinical value in detecting pathologic reflux in symptomatic patients with negative endoscopy.

Acids↗
PubMed1989

Plasma cholecystokinin and gallbladder responses to intraduodenal fat in gallstone patients.

Impaired gallbladder emptying is one of the various factors suggested to be involved in the pathogenesis of gallstones. The present study was undertaken to determine whether gallbladder emptying, endogenous cholecystokinin (CCK) secretion, or their interrelation is altered in patients with gallstones. After intraduodenal administration of 60 ml corn oil, plasma CCK concentration was measured by a sensitive and specific radioimmunoassay and gallbladder emptying by cholescintigraphy. Patients with gallstones (N = 20) produced significantly less endogenous CCK (105 +/- 17 pmol/liter 60 min; P less than 0.001) than control subjects (191 +/- 11 pmol/liter 60 min, N = 20); gallbladder emptying in the patients was significantly decreased at 5, 10, 40, 45, and 50 min but the reduction in gallbladder emptying did not reach statistical significance at 60 min (patients 44 +/- 8%, control subjects 60 +/- 4%). In addition, the gallbladder responsiveness to intravenous infusion of the synthetic CCK analog cerulein was investigated. Based on the results of gallbladder emptying in response to endogenous and exogenous CCK, four subgroups of gallstone patients were identified: (1) a group (N = 7) with normal gallbladder sensitivity to CCK, (2) a group (N = 6) with significantly increased gallbladder sensitivity to CCK, (3) a group (N = 6) with impaired gallbladder emptying after corn oil due to a significantly reduced endogenous CCK secretion but with normal gallbladder sensitivity to CCK, and (4) one patient whose gallbladder was unresponsive to CCK and was found to have chronic cholecystitis at surgery.

Ceruletide↗
PubMed1989

Role of the gastric phase in fat-induced gallbladder contraction and cholecystokinin secretion in humans.

The present study was undertaken to investigate the role of the gastric phase of fat-induced gallbladder contraction and endogenous cholecystokinin (CCK) secretion in humans. Gallbladder emptying, measured by cholescintigraphy, and endogenous CCK secretion, measured by radioimmunoassay, were studied in healthy subjects after both intragastric and intra-intestinal administration of corn oil. In addition, patients with partial gastrectomy were investigated to study the effect of accelerated gastric emptying. In the healthy subjects, intragastric administration of fat resulted in a significantly (P less than 0.05) later increase in plasma CCK levels (20 +/- 2 min) compared to intraintestinal fat (5 +/- 1 min). Similarly, the onset of gallbladder emptying was significantly (P less than 0.05) delayed after intragastric fat (20 +/- 2 min) compared to intestinal fat (10 +/- 1 min). In the healthy subjects the integrated plasma CCK response to intragastric fat was significantly (P less than 0.005-P less than 0.01) reduced from 10 to 30 min. In the patients with partial gastrectomy the rise in plasma CCK (10 +/- 1 min) and the onset of gallbladder emptying (15 +/- 2 min) were in the same range after intra-intestinal and intragastric fat. No significant differences in plasma CCK levels, integrated CCK response or gallbladder emptying were found in the patients according to the site of fat application. It is concluded that endogenous CCK secretion and gallbladder emptying in response to intragastric fat are significantly delayed in healthy subjects but not in patients with partial gastrectomy, in whom gastric emptying is accelerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Reversible gall bladder dysfunction in severe pancreatic insufficiency.

The present study was undertaken to examine the intestinal phase of cholecystokinin (CCK) secretion and gall bladder contraction in patients with severe pancreatic insufficiency. Plasma CCK concentrations, measured by radioimmunoassay, and gall bladder contraction by cholescintigraphy were studied in response to intraduodenal fat with and without addition of pancreatic enzymes. Fasting plasma CCK concentrations were in the same range in six patients with pancreatic insufficiency with (2.6 (0.2) pmol/l) and without (2.6 (0.3) pmol/l) addition of pancreatic enzymes and in six healthy subjects (2.0 (0.4) pmol/l). The integrated plasma CCK secretion in response to intraduodenal fat was significantly (p less than 0.005) reduced in the patients without addition of enzymes (46 (13) pmol/1.90 min) compared with healthy subjects (199 (22) pmol/1.90 min), but increased significantly (p less than 0.01) by the addition of pancreatic enzymes (174 (25) pmol/1.90 min) to values not significantly different from healthy subjects. Similarly, gall bladder emptying in response to intraduodenal fat was significantly (p less than 0.01) reduced in patients with pancreatic insufficiency without addition of enzymes (at 90 min: 35 (11)%) compared with healthy subjects (at 90 min: 66 (7)%) but significantly (p less than 0.01) increased by addition of pancreatic enzymes (at 90 min: 70 (8)%) to values not significantly different from healthy subjects. These results indicate that patients with severe pancreatic insufficiency have impaired gall bladder emptying after intraduodenal fat, which can be normalised by the addition of pancreatic enzymes. This impaired gall bladder emptying appears to be the result of a reduced plasma CCK response. Thus, intra-intestinal pancreatic enzymes play an important role in the intestinal phase of CCK secretion and gall bladder emptying.

Adult↗
PubMed1989

Simultaneous measurement of gallbladder emptying with cholescintigraphy and US during infusion of physiologic doses of cholecystokinin: a comparison.

Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying.

Adult↗
PubMed1989

Delayed plasma cholecystokinin and gallbladder responses to intestinal fat in patients with Billroth I and II gastrectomy.

This study was undertaken to examine the intestinal phase of cholecystokinin (CCK) secretion and gallbladder contraction in patients who had undergone partial gastrectomy. Plasma CCK concentrations, measured by radioimmunoassay, and gallbladder contraction, measured by cholescintigraphy, were studied after intestinal administration of fat. Fasting plasma CCK concentrations were in the same range in nine patients who had undergone Billroth I gastrectomy (1.0 +/- 0.2 pmol/L), in nine patients who had undergone Billroth II gastrectomy (1.4 +/- 0.2 pmol/L), and in nine normal subjects (1.5 +/- 0.4 pmol/L). The peak increments in plasma CCK after intestinal fat were significantly (p less than 0.05) lower in patients with partial gastrectomy (5.4 +/- 0.6 pmol/L) compared with normal subjects (7.9 +/- 0.8 pmol/L). The integrated plasma CCK secretion was significantly (p less than 0.01 to p less than 0.05) reduced during the first 30 minutes in patients after Billroth I (74 +/- 11 pmol/1.30 min) and Billroth II gastrectomy (51 +/- 11 pmol/1.30 min) compared with normal subjects (122 +/- 18 pmol/1.30 min). Similarly, the start of gallbladder emptying was significantly (p less than 0.05) delayed in patients after partial gastrectomy. After 1 hour, however, the integrated plasma CCK response and gallbladder emptying were in the same range in Billroth I patients (186 +/- 34 pmol/1.60 min, 60% +/- 7%), Billroth II patients (175 +/- 17 pmol/1.60 min, 63% +/- 7%) and normal subjects (190 +/- 18 pmol/1.60 min, 55% +/- 6%). It is concluded that in patients who have undergone partial gastrectomy plasma CCK and gallbladder responses to intestinal fat are significantly delayed but reach normal levels beyond 30 minutes.

Adult↗