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Biomedical subjects

A Morelli

Publications and source records attributed to A Morelli.

At least 19 recordsLinked to original sources

Oral bile acid treatment and the patient with Zellweger syndrome.

The cerebrohepatorenal syndrome of Zellweger is a congenital syndrome of multiple manifestations, including hepatomegaly and liver dysfunction. Treatment is generally of a supportive nature, aimed at improving nutrition and growth, controlling the central nervous system symptoms and limiting progression of liver disease. Because the liver disease in Zellweger syndrome may be attributed to an overproduction and accumulation of cholestanoic acids, exacerbated by diminished primary bile acid synthesis, we hypothesized that primary bile acid administration would be beneficial in improving liver function by a mechanism involving down-regulation in the synthesis of these atypical bile acids. We report here the clinical and biochemical responses to primary bile acid administration in a 2-mo-old boy who was seen with the typical signs of Zellweger syndrome. Liver disease was evident from hepatomegaly and elevated serum liver enzymes and bilirubin. The diagnosis was supported by markedly elevated serum very long chain fatty acids and the bile acids dihydroxycholestanoic acid and trihydroxycholestanoic acid. Confirmation of the lack of peroxisomes was established by electron microscopy. When the patient was 6 mo old, the primary bile acids cholic acid and chenodeoxycholic acid, (100 mg each/day) were administered orally. A significant improvement in biochemical indices of liver function occurred with a normalization of the serum bilirubin and liver enzymes and a histological improvement in the extent of inflammation and bile duct proliferation and disappearance of cannalicular plugs. Serum and urinary cholestanoic acids showed a significant decrease within a few days. A striking and sustained increase in growth was observed after therapy, and an improvement in neurological symptoms was noted. In conclusion, this study indicates that primary bile acid therapy improves liver function and growth in the patient with peroxisomal dysfunction and should be considered in the supportive therapies for this condition.

Administration, Oral

Effect of erythromycin on gallbladder emptying in diabetic patients with and without autonomic neuropathy and high levels of motilin.

A reduction of gallbladder emptying in response to neural or hormonal stimulation has been reported in patients with diabetes mellitus. Decreased gallbladder emptying may be a key factor in the pathogenesis of gallbladder stones. Few drugs, if any, are able to stimulate gallbladder emptying. However, in a previous study we demonstrated that erythromycin, a macrolide antibiotic, stimulates gallbladder emptying and motilin release in healthy human subjects by an atropine-sensitive pathway. Therefore, the present study was designed to evaluate the effect of erythromycin on gallbladder emptying and motilin release in diabetic patients with or without cardiac autonomic neuropathy (AN). Thirteen diabetic patients, six with AN, and 10 healthy subjects were enrolled in the study protocol. Gallbladder emptying was determined by sonography after ingestion of a standard meal and during infusion of erythromycin alone or together with 6 micrograms/kg/hr atropine. We found that 100 mg/hr erythromycin caused a significant reduction in gallbladder volume in both healthy subjects and diabetic patients. The ejection fraction (mean +/- SE) of 45.3 +/- 8.2% and 37.3 +/- 5.0% was similar. The presence of AN had no influence on gallbladder emptying induced by erythromycin. Basal motilin plasma levels were 111.5 +/- 14.5 pmol/liter in diabetic patients and 63.3 +/- 6.0 pmol/liter in healthy subjects (P < 0.01). However, patients with AN had higher (130.0 +/- 11.9 pmol/liter) motilin plasma levels than patients without (74.0 +/- 9.4 pmol/liter, P < 0.01). Erythromycin administration caused an approximately twofold increase in plasma motilin concentrations in healthy subject and patients without AN, but did not stimulate motilin release in neuropathic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Erythromycin stimulates gallbladder emptying and motilin release by atropine-sensitive pathways.

The effect of administering different doses of erythromycin on gallbladder emptying and plasma concentrations of immunoreactive motilin was investigated in healthy volunteers. Erythromycin was infused for 30 min at four different doses: 20, 50, 100, and 1000 mg/hr. Gallbladder volume was determined by ultrasound scanning every 10 min for 60 min. All doses, except 20 mg/hr, provoked a significant reduction in gallbladder volume (P < 0.01). The gallbladder emptying peak occurred after 20 min infusion. It was approximately 40-45% of basal volume and 60-70% of the emptying observed after a standard meal. At 100 mg/hr, erythromycin caused a 2.5-fold increase in plasma motilin concentration, which reached a peak after 30 min infusion. Plasma motilin peaked following maximum gallbladder emptying in all subjects. To evaluate whether cholinergic pathways were implicated in the action of erythromycin, 100 mg/hr erythromycin was infused together with 6 micrograms/kg/hr atropine. Atropine inhibited both gallbladder emptying and motilin release (P < 0.001). Infusion of 1 microgram/kg/hr somatostatin had the same inhibitory effects (P < 0.001). Our results suggest that atropine acts by inhibiting an erythromycin-activated cholinergic neural mechanism. Somatostatin could exert its inhibitory effect by blocking the release of acetylcholine from neural terminations.

Adult

Placebo-controlled comparison of piroxicam-beta-cyclodextrin, piroxicam, and indomethacin on gastric potential difference and mucosal injury in humans.

The acute gastroduodenal mucosa injury and gastric potential difference (GPD) drops provoked by 14-day administration of 20 mg/day of a new piroxicam formulation (piroxicam-beta-cyclodextrin), 20 mg/day standard piroxicam and 100 mg/day indomethacin were evaluated and compared in a randomized, double-blind, placebo-controlled study carried out on 64 volunteers. Endoscopic examinations, performed after 14-day treatment, demonstrated that piroxicam-beta-cyclodextrin was less gastrolesive (mean endoscopic score +/- SE = 0.56 +/- 0.2) than either piroxicam (2.06 +/- 0.5) or indomethacin (2.25 +/- 0.5) (p < 0.01). The drop in GPD after a single dose of the assigned drug was considerably greater for piroxicam and indomethacin than for piroxicam-beta-cyclodextrin (p < 0.01), which registered similar values to placebo. Since GPD is an expression of the anatomo-functional integrity of the gastric barrier, the results indicate that piroxicam-beta-cyclodextrin exerts less direct acute damage on the gastric mucosa. Therefore, when administered short-term, piroxicam-beta-cyclodextrin appears to be less gastrolesive than either indomethacin or the standard piroxicam formulation.

Adult

Abnormal rectosigmoid myoelectric response to eating in patients with severe idiopathic constipation (slow-transit type).

Pathophysiologic mechanisms responsible for severe chronic constipation are poorly understood. In particular, most of the published studies have lumped together patients having different subtypes of constipation, with different and often conflicting results. We studied six patients complaining of severe idiopathic constipation and displaying homogeneous clinical and pathophysiologic features (i.e., patients with slow-transit type constipation) to evaluate their myoelectric spiking responses to food ingestion. Ten healthy subjects acted as controls. The constipated patients failed to show the increase in myoelectric spiking activity that was seen in controls immediately following the meals, suggesting the possibility of a neurogenic defect in this condition.

Action Potentials

Esophageal motor disorders in patients evaluated for dysphagia and/or noncardiac chest pain.

During the period January, 1983-October, 1990, 429 subjects were referred for functional evaluation of dysphagia and/or noncardiac chest pain. Of these, 304 (70.8%) were shown to have some kind of esophageal motor abnormality. The most frequent motor abnormality of the esophagus was represented by nonspecific motor disorders (31%), followed by achalasia (13%), whereas the other dysfunctions accounted for a smaller percentage. In particular, diffuse esophageal spasm was shown to be quite rare. It is concluded that esophageal manometry may provide a high diagnostic yield in patients presenting with dysphagia and/or noncardiac chest pain.

Chest Pain

Gastric acidity and gastroesophageal reflux patterns in patients with esophagitis.

Esophageal pH-metry is the test of choice for diagnosing gastroesophageal reflux. However, although it allows acid refluxes to be distinguished, it is of limited value for identifying alkaline or mixed (acid mixed with alkaline material) refluxes. To evaluate the ability of dual pH-metry to identify alkaline or mixed refluxes, the gastric acidity and gastroesophageal reflux pattern were evaluated simultaneously in 64 patients with mild-moderate esophagitis, in 28 patients with severe or complicated esophagitis, and in 20 healthy subjects. A dual esophageal gastric pH-probe allowed three different types of esophageal reflux to be distinguished: (a) acid refluxes, defined as a drop in esophageal pH to values less than 4 together with a gastric pH less than 4; (b) mixed refluxes, defined as a drop in esophageal pH from baseline to values greater than 4 associated with rises in gastric pH to greater than 4 values; (c) alkaline refluxes, defined as a rise in esophageal pH to greater than 7 associated with a simultaneous increase in gastric pH to greater than 4. Gastric acidity was more significantly reduced in patients with severe or complicated esophagitis than it was in healthy subjects (P less than 0.01). The reflux pattern in both mild-moderate and severe esophagitis was characterized by mainly acid refluxes and a marked increase in the time the esophagus mucosa was exposed to acid (P less than 0.001). Pure alkaline refluxes were rare (less than 1%) in both healthy subjects and esophagitis patients. The number of mixed refluxes was considerably higher in severe esophagitis patients than it was in either mild-moderate esophagitis patients or controls (P less than 0.05). The finding of mixed refluxes in severe or complicated esophagitis suggests that biliary acids and/or pancreatic enzymes are involved in the pathogenesis of severe forms of esophagitis.

Esophagitis, Peptic

Intestinal pseudoobstruction secondary to hypothyroidism. Importance of small bowel manometry.

Hypothyroidism may lead to secondary pseudoobstruction. We report a patient with intestinal symptoms from hypothyroidism in which previous conventional examinations were negative. Gastrointestinal manometry disclosed features of pseudoobstruction, and we discuss the importance of performing functional studies in selected cases, in as much as symptoms seemed to resolve on replacement therapy.

Aged

Calcium adenosinetriphosphatase of bovine retinal rod outer segment disks.

A Ca(2+)-pumping ATPase activity is present in bovine retinal rod outer segment purified disks. The ATPase has a high Ca2+ affinity (KM = 25 microM). Low Ca2+ (n-microM) concentrations stimulate an ATP-dependent Ca2+ uptake and the ATP hydrolysis in the absence of exogenous Mg2+. Electrophoretic analysis of disk proteins after treatment with (gamma-32P)ATP shows the existence of the enzyme-phosphate acid-stable, hydroxylamine-sensitive intermediate complex of molecular mass of about 135 kDa. The results would indicate the presence of an inwardly directed Ca(2+)-ATPase pump acting on the disk membrane, that could be involved in the regulation of cytosolic free Ca2+ levels inside ROS.

Adenosine Triphosphate

Impaired colonic motor response to eating in patients with slow-transit constipation.

Because little is known about the pathophysiological mechanisms responsible for chronic idiopathic constipation, we studied colon motor response to eating, one of the most physiological and reproducible stimuli, in a clinically homogeneous group of severely constipated subjects. Fifteen patients (14 women, one man) with slow transit constipation (average duration of symptoms 18 +/- 2 yr) entered the study. After colonoscopic positioning of a manometric probe, 2-h basal and 3-h postprandial (1000 kcal standard mixed meal) recordings were obtained. Comparison of tracings with those of 29 healthy volunteers showed that motor response to eating was decreased in constipated subjects. Patients' response was characterized by a shorter duration of contractile activity in all three colon segments studied, after ingestion of the meal, and significantly less high-amplitude propagated contractions (7% vs. 45%). We conclude that several mechanisms are involved in the pathophysiology of colon contractile motor function of patients with chronic idiopathic constipation.

Adult

Isolated hypertensive lower esophageal sphincter. Clinical and manometric aspects of an uncommon esophageal motor abnormality.

The hypertensive lower esophageal sphincter is an infrequent primary esophageal motor disorder characterized by elevated mean lower esophageal sphincter pressure (greater than or equal to 3 SD from that of controls), sphincter relaxations greater than 75%, and normal peristaltic activity in the esophageal body. This disorder is frequently associated with the nutcracker esophagus. We report our clinical and manometric experience with the isolated hypertensive lower esophageal sphincter (i.e., unassociated with other motor disorders), which constituted 2.7% of all patients who complained of dysphagia or chest pain referred for manometry during the period from October 1982 to February 1991.

Adult

Extensive investigation on colonic motility with pharmacological testing is useful for selecting surgical options in patients with inertia colica.

Three women with idiopathic severe chronic constipation and inertia colica, who failed to respond to medical treatment, were extensively investigated for gut motor function, especially that of the colon. Twenty-four-hour manometric recordings disclosed that motility was severely reduced throughout the entire colon and response to eating was minimal. One of the patients also was tested for esophageal, gastric, and small bowel motor activity, which gave normal results. Edrophonium chloride stimulation (10 mg iv) provoked no increase in colonic contractile activity in any patient. On these grounds, the patients were submitted to surgical intervention (total colectomy with ileorectal anastomosis two, and left hemicolectomy the other) with fairly good results at follow-up. These results indicate the wisdom of carrying out extensive functional investigations in severely constipated patients before surgery is contemplated.

Colon

Effects of parenteral diclofenac sodium on upper gastrointestinal motility after food in man.

In experimental animal models nonsteroidal anti-inflammatory drugs may influence gastrointestinal motility, but as evidence is lacking in man. The effect of diclofenac sodium 75 mg i.m. on the motor response of the upper gastrointestinal tract to food has been studied by manometry in 9 healthy volunteers. Diclofenac had no effect on the motor activity of the stomach, duodenum, or jejunum after a 605 kcal meal.

Adult

Control of gastric pH with ranitidine in critically ill patients. Comparison of two intravenous regimens.

The effects of continuous versus bolus administration of ranitidine on gastric pH were compared in critically ill patients admitted to our intensive care unit. Patients were randomized to receive 0.2 mg/kg/hr ranitidine in continuous infusion or 50 mg in bolus every 4 hr. The pH was monitored throughout a 24-hr period, 2 hr in basal conditions and 22 hr during treatment, with a gastric probe. Basal gastric pH was 2.1 +/- 0.2 in the infused and 2.4 +/- 0.2 in the bolus group (P greater than 0.05). The hydrogen ion concentrations were 25.1 +/- 8 and 20.0 +/- 7 mmol/liter, respectively (P greater than 0.05). After ranitidine administration, mean pH was 6.3 +/- 0.6 in patients treated by infusion and 4.5 +/- 0.5 (P less than 0.001) in those who received the drug in bolus; hydrogen ion concentration was 2.5 +/- 2 and 6.9 +/- 6, respectively, (P less than 0.001). Percent of inhibition of acid secretion was 90% in the infused and 68% in the bolus group. Infusion raised pH to values constantly above 4, whereas bolus administration resulted in wide fluctuations. These data indicate that continuous infusion of ranitidine is superior to bolus administration in controlling gastric acidity in critically ill patients.

Adult

Edrophonium chloride for testing colonic contractile activity in man.

The effects of cholinergic stimulation on the entire human colon are at present relatively unknown. For this reason, we evaluated the influence of a short-lived anticholinesterase agent, edrophonium chloride, on proximal and distal colonic contractile activity in man. Eight healthy volunteers of both sexes were studied with a multi-lumen manometric probe positioned with the aid of a colonoscope. Recordings were then obtained 30 minutes pre- and post-drug administration. Edrophonium chloride (10 mg intravenous) significantly stimulated both proximal and distal colonic contractile activity, and the maximum increase was observed within 10 minutes following injection, although some differences were observed between colonic segments in response to the drug. No important side effects were complained of after edrophonium. Due to the potent stimulatory property on colonic smooth muscle, to its short duration of action, and to the paucity of side effects, it is concluded that edrophonium chloride may be useful as a stimulating substance during manometric investigations of the human colon.

Adult