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Biomedical subjects

A Ertan

Publications and source records attributed to A Ertan.

At least 55 records · Page 3Linked to original sources

Alterations in cholinergic muscarinic and somatostatin binding sites in a patient with idiopathic intestinal pseudo-obstruction.

We present a comparative study of cholinergic muscarinic and somatostatin binding sites on isolated membranes from mucosa and tunica muscularis of normal and dilated parts of the proximal jejunum obtained at surgery from a patient with idiopathic intestinal pseudo-obstruction (IIP) syndrome. We found a statistically significant diminution of cholinergic muscarinic and somatostatin binding sites in mucosa taken from the dilated part of the jejunum, compared with those taken from the normal part. Tunica muscularis of the dilated part of the jejunum contained a significantly higher concentration of peripheral cholinergic muscarinic binding sites (M2) than the normal part did, whereas concentration of M1 cholinergic muscarinic and somatostatin binding sites was similar in both examined parts. These results indicate that IIP-syndrome may be related to alterations in cholinergic muscarinic binding sites in the tunica muscularis of the intestine.

Adult↗

Somatostatin, gastrin, and cholinergic muscarinic binding sites in rat gastric, duodenal, and jejunal mucosa.

Clinical and experimental data indicate that the concentration of gastrin-I and somatostatin binding sites in human and rat gastric and duodenal mucosa may be changed in several pathologic conditions, including human peptic ulcer and cancer diseases. There are no data, however, indicating the distribution of receptor binding sites in the normal upper gastrointestinal tract. We studied the regional distribution of somatostatin-14, gastrin-I, and cholinergic muscarinic binding sites in membrane preparations from rat gastric corporeal and antral mucosa and in mucosa obtained from the duodenum and jejunum. The corporeal mucosa contained the most high-affinity gastrin binding sites (Bmax = 39.1 +/- 6.5 fmol/mg protein; Kd = 1.1 +/- 0.4 nM). The antral mucosa contained the most somatostatin and cholinergic muscarinic binding sites (Bmax = 65.7 +/- 6.6 fmol/mg protein and 460.3 +/- 101.8 fmol/mg protein, respectively). The duodenal and jejunal mucosal membranes contained somatostatin, gastrin, and cholinergic muscarinic binding sites in decreasing concentrations. Concentrations of binding sites are characteristic for particular gut regions and may help in analyzing their abnormalities.

Animals↗

Regulation of somatostatin-14 and gastrin I binding sites in rat gastrointestinal mucosa by ulcerogenic dose of cysteamine.

A single duodenal ulcerogenic dose of cysteamine administered into rats induced time-dependent depletion of immunoreactive somatostatin in the gastric corporeal, antral, and duodenal mucosa with a parallel increase (up-regulation) of somatostatin binding sites. The concentration of somatostatin binding sites returned to the control level in the corporeal mucosa when measured at 24 hrs; however, in the duodenal mucosa there was only a partial return to the control level. Somatostatin binding sites in the antral mucosa did not return to control level even after 24 hrs. Except for the duodenum mucosal immunoreactive gastrin level was unaffected by cysteamine administration, but corporeal mucosal gastrin I binding sites were diminished (down-regulation) after 24 hrs.

Animals↗

Mechanism of release of gastric luminal somatostatin-like immunoreactivity in response to pentagastrin and sham feeding in man.

We studied in five healthy volunteers whether the cholinergic pathway regulated the secretion of gastric intraluminal somatostatin-like immunoreactivity (SLI) in response to stimuli of pentagastrin infusion (0.9 micrograms/kg/h, intravenously) and sham feeding. We measured gastric secretory volume, hydrogen ion output, and SLI at base line, during pentagastrin infusion, after sham feeding, and after applications of atropine (0.0, 0.7, 7.0 micrograms/kg, intramuscularly) given before pentagastrin and sham feeding. The stimuli were given randomly, at separate times on different days. After each stimulus, eight 15-min gastric juice collections were made; samples were adjusted to pH 7, pepstatin-A and aprotinin were added, and samples were extracted with acetone to determine SLI by radioimmunoassay. Pentagastrin and sham feeding significantly increased gastric luminal SLI secretion, which appeared to correlate with the increases in volume and acid output. Atropine at 7 micrograms/kg significantly suppressed gastric volume, acid, and SLI outputs stimulated by sham feeding; however, responses to pentagastrin stimulation remained unchanged. To conclude, the cholinergic mechanism regulates gastric intraluminal SLI response to sham feeding but not to pentagastrin infusion.

Adult↗

Obstructing pseudocyst of the duct of Santorini in pancreas divisum.

Pancreas divisum is a pancreatic duct anomaly that occurs due to failure of fusion of the dorsal and ventral ducts. While recognition of this anomaly is increasing due to more aggressive endoscopic retrograde cholangiopancreatography, its significance remains unclear. A patient with chronic pancreatitis and a history of alcohol abuse was noted to have pancreas divisum. At surgical exploration, intraoperative pancreatography revealed an obstructing pseudocyst of the duct of Santorini. Extended sphincteroplasty and cystduodenostomy as well as Roux-en-Y pancreatojejunostomy were necessary to insure adequate accessory duct drainage. Surgical therapy of pancreas divisum in chronic pancreatitis should be designed to correct existing pancreatic duct obstruction.

Adult↗

Luminal gastric somatostatin-like immunoreactivity in response to various stimuli in man.

This study investigates release of somatostatin-like immunoreactivity (SLI) into the gastric lumen of five healthy human subjects in response to pharmacological stimuli (pentagastrin and secretin) and physiological stimuli (sham feeding and intrajejunal perfusion of elemental diet). Basal and poststimulation gastric juice aspirates were collected at 15-min intervals, extracted with acetone, and SLI determined by radioimmunoassay, with these results: A considerable amount of SLI was secreted during the basal period. Pentagastrin stimulated SLI release quickly and was associated with increased acid secretion. Both secretin and sham feeding increased SLI only slightly. During intrajejunal perfusion of the elemental diet, SLI increased significantly, was associated with decreased acid secretion, and rapidly returned to basal level when elemental diet was replaced by saline. Basal levels of gastric luminal SLI thus showed distinct changes in response to each stimulus. Although the physiological action of luminal SLI remains to be studied, its levels may reflect gastric D-cell activities.

Adult↗

Upper gastrointestinal endoscopy in normal asymptomatic volunteers.

In a prospective study, 355 healthy, asymptomatic, male volunteers, 18 to 45 years of age, were screened by esophagogastroduodenoscopy before admission to clinical trials. One hundred thirty-four volunteers (38%) showed abnormal endoscopic findings. Some volunteers had more than one site of involvement or more than one grade of lesion in each anatomic location. In 49 (14%) of these subjects the esophagus was a site of involvement, while in 86 (24%) the stomach was involved, and in 71 (20%) the duodenum was involved. The point prevalences in these asymptomatic subjects were 8.5% for erosive esophagitis, 12% for erosive gastritis, 10% for erosive duodenitis, 2% for gastric ulcer, and 2% for duodenal ulcer.

Adolescent↗

A new criterion in the assessment of bentiromide as a test of exocrine pancreatic function in alcoholics.

Bentiromide (N-benzoyl-L-tyrosyl-p-aminobenzoic acid; Bz-Tyr-PABA) is a useful agent in the assessment of exocrine pancreatic function. Bz-Tyr-PABA is hydrolyzed by chymotrypsin in the intestine with liberation of PABA and its metabolic products, arylamines. This study was undertaken to determine the normal values for absorption and excretion of arylamines in normal volunteers and in alcoholics without detectable disorders of the pancreas, liver, or small intestine. After an overnight fast, basal blood and urine samples for baseline arylamine levels were collected, followed by oral administration of 500 mg of bentiromide. A 6-h urine collection was instituted, and 90- and 120-min plasma samples were obtained. The results were analyzed comparing normals and alcoholics: The mean concentration of arylamines was significantly higher in alcoholics than nonalcoholic subjects in baseline urine and in plasma at 90 and 120 min; no significant difference was found between alcoholics and nonalcoholics when comparing mean arylamine levels in 6-h urines. In summary, cumulative 6-h urine arylamine levels are more reliable as a criterion than 90- and 120-min plasma levels in the assessment of exocrine pancreatic function in alcoholics.

4-Aminobenzoic Acid↗

Light and electron microscopic studies of diet-induced hepatic changes in mice.

Adult mice were fed a choline-deficient ethionine enriched (CDE) diet for 24, 48 or 72 h. They were then fasted for 24 or 48 h prior to sacrifice. All tissues were studied by light and electron microscopy. Animals fed the CDE diet for 24 h exhibited cells with vacuolated cytoplasm, and the accumulation of lipid in these cells was clearly abnormal. Animals fed the CDE diet for 24 h and subsequently a regular diet for 48 h displayed normal hepatocytes, suggesting that the alterations at 24 h were reversible. Following 48 or 72 h of feeding the CDE diet, abundant lipid-laden cells were observed in the hepatic lobules, and at the electron microscope level these cells were undergoing frank degeneration. Evidence indicated that changes after 48 or 72 h were irreversible.

Animals↗

Pancreatic immunoreactive somatostatin and diabetes mellitus.

Pancreatic secretions were collected during endoscopic retrograde cholangiopancreatography from 15 subjects without pancreatic, biliary, or hepatic diseases, 11 patients with non-insulin-dependent diabetes, and 11 patients with insulin-dependent diabetes. Pancreatic secretion was stimulated by the intravenous administration of one unit of secretin per kilogram of body weight. Immunoreactive somatostatin (IRS) in the pancreatic juice of the nondiabetic subjects ranged from 43 to 97 pg/ml, in non-insulin-dependent diabetics from 5 to 3872, and in the insulin-dependent diabetics from 0 to 2093. IRS in insulin-dependent diabetics under good plasma glucose control ranged from 0 to 281 pg/ml, compared to those under poor control who ranged from 518 to 2093 pg/ml. These results indicate that IRS in pancreatic juice is higher in poorly controlled insulin-dependent diabetics than in well controlled insulin-dependent diabetics and nondiabetics. Whether these changes in IRS are purely secondary phenomena or play some pathogenetic role in the disturbed metabolism of diabetes remains to be proven. The chromatographic profile of IRS in pancreatic juice on both gel filtration and high-performance liquid chromatography has indicated that these IRS moieties represent somatostatin 14 and somatostatin 28.

Adult↗

Effect of potassium chloride supplements on upper gastrointestinal mucosa.

Eight controlled 1- or 2-wk experiments involving 225 healthy male subjects and one study of 18 patients with hypertension, nine of whom were long-term users of a wax-matrix potassium chloride preparation, were conducted to evaluate the upper gastrointestinal safety of oral KCl supplements. All subjects in the short-term studies had normal upper gastrointestinal tracts. Subjects were examined again after at least 7 days of treatment with one of three commonly prescribed wax-matrix KCl tablets, KCl liquid, microencapsulated KCl, a potassium- sparer , or placebo. Some received an anticholinergic drug with treatment to induce delayed gastric motility. Diet and compliance to treatment regimens were controlled. Results indicate that upper mucosal injury, particularly erosions (43%) and ulcerations (11%), were more frequent after wax-matrix tablets. These changes occurred much less frequently after liquid KCl (0%), microencapsulated KCl (10.5% erosions, 1.2% ulcers), and the potassium-sparing drug (0%). More serious and more frequent lesions were associated with slowed motility. No occult bleeding was noted. Symptomatic complaints did not correlate with endoscopic findings. In the long-term study, patients with hypertension were examined endoscopically after 19 to 23 mo on KCl and again after 1 wk. Six of nine of the patients with hypertension treated for nearly 2 yr with a wax-matrix KCl supplement had significant lesions. One had developed ulceration after 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Delayed-Action Preparations↗

Mucosal irritant potential of a potassium-sparing diuretic and of wax-matrix potassium chloride.

To measure their relative upper gastrointestinal irritant potential, either 5 mg amiloride and 50 mg hydrochlorothiazide (twice daily) or 24 mEq wax-matrix potassium chloride (three times a day) were given to 30 normal subjects with no prior endoscopic abnormalities in the esophagus, stomach, or duodenum. All subjects received glycopyrrolate, 2 mg (3 times a day) to slow gastric emptying. Repeat endoscopy after 7 days of treatment with wax-matrix potassium chloride revealed that 10 of 15 (67%) of the subjects developed one or more gradable upper gastrointestinal lesions (esophageal ulcer, gastric ulcer, eight cases of one or more mucosal erosions, and four cases of hyperemia or edema of the esophagus, stomach, or duodenum). Four subjects (27%) taking amiloride/hydrochlorothiazide developed either mild hyperemia or edema, but there were no erosions or ulcers in this group.

Amiloride↗

The mechanism of cholestasis from hepatic hydatid cysts.

Cholestasis is a common complication of hepatic hydatid cyst. We describe the various mechanisms of cholestasis in hepatic hydatid cyst as demonstrated by percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) in 16 patients. In our patients, cholestasis was the result of rupture or mechanical pressure of the cyst on the biliary system. Direct visualization of the bile duct, especially by PTC, provided precise definitions of the pathology, and aided the surgeon in his approach. There were no adverse reactions. All preoperative diagnoses were confirmed at operation.

Adult↗