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Biomedical subjects

U G Meneghelli

Publications and source records attributed to U G Meneghelli.

At least 37 records · Page 2Linked to original sources
PubMed1985

Dysphagia lusoria and segmental aperistalsis in the upper third of the esophagus.

An aperistaltic zone located in the upper third of the esophagus was present in a young woman with dysphagia, who had undergone surgical treatment for dysphagia lusoria 3 months before. The segmental absence of contraction in the upper third of the esophagus was the most probable cause for the persistence of dysphagia, and could have resulted from damage related to compression or to surgical intervention in the area.

Adult↗
PubMed1985

Chagas' disease: a model of denervation in the study of digestive tract motility.

The enteric nervous system (ENS) is an important neural network that integrates, modulates and coordinates various motor functions of the digestive tract. Chagas' disease, to a variable extent and in a nonsystematic way, causes destruction of ENS neurons throughout the digestive tract. The studies carried out on the pathophysiology of the digestive form of this disease have provided, as a corollary, a better understanding of the participation of the ENS in the regulation of the normal motor activities of the digestive tract and have led to the conclusion that the disease is a true model of intrinsic denervation of the human digestive tract. Among the motor alterations caused by impairment of the digestive tract in Chagas' disease are: absence of peristalsis in the esophagus, achalasia of the cardia, loss of the accommodation reflex in the proximal stomach, gastric emptying disorders, changes in the migrating motor complex (MMC), disappearance of postprandial motor phenomena in the colon and rectum, lack of relaxation of the internal sphincter of the anus, and anomalous responses of the gall bladder to cholekinetic stimuli.

Biliary Tract↗
PubMed1985

Plasma gastrin and gastric acid responses to insulin hypoglycemia in Chagas' disease.

Plasma gastrin and gastric acid responses to intravenous injection of insulin (0.2 IU/kg) were measured in 8 patients with Chagas' disease, which is known to be associated with extensive reduction of the intramural neurons of the digestive tract, and in 6 control subjects. All subjects developed hunger, sweating and tachycardia, and exhibited less than 50 mg/dl venous blood glucose. Plasma gastrin responses in Chagas' disease patients (median: 3.60 nmol L-1 min-1; range: 1:12 to 10.60 nmol L-1 min-1) were significantly higher than for control subjects (median: 0.52 nmol L-1 min-1; range: 0.25 to 1.09 nmol L-1 min-1). Gastric acid output was significantly lower in Chagas' disease patients (median: 3.5 mmol/h; range: 2.1 to 13.6 mmol/h) than in controls (median: 30.3 mmol/h; range: 7.3 to 38.2 mmol/h). These data show that chagasic patients have abnormally high gastrin release and low gastric acid secretion in response to insulin, and thus indicate that loss of intrinsic innervation of the stomach does not abolish the gastrin response to insulin hypoglycemia.

Adult↗
PubMed1984

The effect of a segmental gastrectomy with proximal gastric vagotomy on gastric secretion and gastric emptying.

Gastric acid secretory responses to graded doses of pentagastrin were measured in duodenal ulcer patients before and after either proximal gastric vagotomy (17 patients) or proximal gastric vagotomy associated with a segmental gastrectomy (11 patients). Calculated maximal output of acid and responsiveness of the acid-secreting cells to pentagastrin were reduced by both operations; after surgery, maximal acid output was lower in the proximal gastric vagotomy plus segmental gastrectomy group than in the proximal gastric vagotomy group. Gastric emptying of a liquid meal was assessed before and after either proximal vagotomy (13 patients) or proximal gastric vagotomy plus segmental gastrectomy (9 patients). The early phase of emptying was equally accelerated by both operations, and at later stages the emptying was only slightly, but not significantly, faster following proximal gastric vagotomy associated with segmental gastrectomy.

Adolescent↗
PubMed1984

Fasting and food-stimulated plasma gastrin levels in chronic Chagas' disease.

Chagas' disease is known to be associated with extensive lesions of the intramural neurons of the digestive tract. In order to evaluate the contribution of the intramural plexuses to the control of plasma gastrin levels in man, we performed the following measurements: (a) fasting plasma gastrin in 18 chagasic patients and 16 control subjects; (b) integrated gastrin response to food in 9 chagasic patients and 10 controls, (c) basal acid secretion and gastric acid responses to graded doses of pentagastrin in 14 chagasic and 13 controls. Fasting plasma gastrin levels and integrated gastrin response were significantly higher in chagasics than in controls. Basal and maximal acid secretion and responsiveness of acid-secreting gastric cells were lower in chagasics. These results indicate that the intramural plexuses play a role in the control of gastrin release in man.

Adult↗
PubMed1984

Gastric accommodation to distension and early gastric emptying in diabetics with neuropathy.

Gastric accommodation to distension and gastric emptying were assessed in diabetics with neuropathy and in control subjects. Gastric accommodation was measured by recording intragastric pressures during the air insufflation of the stomach and gastric emptying was measured by the double sample test meal after intragastric instillation of 500 ml of saline into the empty stomach. Maximal intragastric pressures during air insufflation were significantly higher in diabetics (N = 6) than in control subjects (N = 15), 16.2 +/- 4.5 vs 10.8 +/- 2.6. The liquid volumes in the stomach five minutes after the instillation of the test meal was significantly smaller in diabetics (N = 10) than in control subjects (N = 17), 208 +/- 90 vs 294 +/- 48 ml, but no differences in volume were detected thereafter. We conclude that diabetics with neuropathy have an impaired gastric accommodation to distension and, probably as a consequence, a rapid early phase of liquid meal gastric emptying.

Adult↗
PubMed1983

Abnormalities of interdigestive motility of the small intestine in patients with Chagas' disease.

The fasting motor activity of the upper small intestine was studied in 36 patients with chronic Chagas' disease, which is known to be associated with extensive lesions of the myenteric plexuses, and the results compared with those obtained in 15 control subjects. The migrating motor complex (MMC) was detected as frequently in the Chagas' disease group as in the control group, and the frequency of contractions during the activity front was virtually the same in the two groups. In the Chagas' group the propagation of the activity fronts was slower, their duration was longer in the jejunum, but not in the duodenum, and the calculated length was shorter than normal. Chagas' disease patients without clinical manifestation or x-ray pathology of the digestive tract had no abnormalities of the MMC. These findings suggest that the intramural nervous system of the gut plays a role in the normal migration of the MMCs along the small intestine.

Adolescent↗
PubMed1983

Effect of pentagastrin on the motor activity of the dilated and nondilated sigmoid and rectum in Chagas' disease.

In order to evaluate the effect of pentagastrin on the motor activity of the sigmoid and rectum in patients with Chagas' disease, manometric studies were performed on 22 chagasic patients, 11 without and 11 with megacolon, and 11 control subjects. Pentagastrin had a stimulating effect on the sigmoid and rectum in control subjects as well as in chagasic patients without megacolon. In chagasic patients with megacolon, pentagastrin had no effect on sigmoid or rectum motility, probably as a result of the intrinsic denervation known to occur in this disease. The findings suggest that the motor effect of pentagastrin on the human sigmoid and rectum depends on the myenteric nervous pathways.

Adolescent↗
PubMed1982

Acid and pepsin secretion in chronic Chagas' disease patients in response to graded doses of pentagastrin and pentagastrin plus bethanecol.

Gastric acid and pepsin secretory responses to graded doses of pentagastrin were measured in 12 Chagas' disease patients and 18 control subjects, and in 7 Chagas' disease patients and 6 controls the study was repeated with an infusion of bethanecol. Calculated maximal outputs of acid and pepsin (Vmax) and responsiveness (D50) of the acid- and pepsin-secreting cells to pentagastrin were lower in the chagasics. Bethanecol had no significant effect on pentagastrin-stimulated gastric secretions in controls. The impairment of responsiveness of the gastric secretory cells in Chagas' disease patients was fully corrected by bethanecol.

Adolescent↗
PubMed1981

Severe strongyloidiasis associated with hypogammaglobulinaemia.

The association of severe strongyloidiasis and hypogammaglobulinaemia in one patient is described. Severe strongyloidiasis was observed twice (March 1971 and June 1974), and the Strongyloides stercoralis infestation probably lasted for at least 58 months (from March 1971 to December 1975), in spite of successive thiabendazole courses of treatment. Immunological studies performed disclosed severe, steady hypogammaglobulinaemia but no abnormality in cell-mediated immunity. The respiratory infections also seen during the follow-up were ascribable more to humoral immunity impairment than to cell-mediated immunity impairment. This is the first report of the association of hypogammaglobulinaemia and severe strongyloidiasis, and it suggests that humoral immunity plays a relevant role in the human defences against S. stercoralis infestation.

Adolescent↗
PubMed1980

Impaired gastric accommodation to distension and rapid gastric emptying in patients with Chagas' disease.

In order to evaluate the contribution of the myenteric plexuses to the control of gastric accommodation to distension and to the rate of gastric emptying of a saline solution in man, we have evaluated these functions in patients with Chagas' disease, which is known to be associated with extensive lesions of the myenteric plexuses. Intragastric pressure was significantly higher (P < 0.05) in Chagas patients (N = 15) than in normal controls (N = 15) for air distension volumes of 100-700 ml. In the range 300-700 ml, the difference between the groups was approximately twofold (P < 0.001). The gastric emptying rate of 500 ml 154 mM NaCl in a second group of Chagas' disease patients (N = 13) was significantly faster than that of the control group (N = 17) at 5 min (P < 0.005) and at 15 min (P < 0.005) after the test meal, but at 25 min the volumes remaining in the stomach were not statistically significant for the two groups (P > 0.10). The impairment of gastric accommodation to distension and consequent rapid gastric emptying demonstrated for chagasic patients emphasizes the role of the myenteric plexuses in gastric reservoir function in man and complements previous evidence obtained in animal studies.

Adolescent↗
PubMed1980

Lower oesophageal sphincter response to pentagastrin in chagasic patients with megaoesophagus and megacolon.

Intraluminal manometric studies were performed in 14 chagasic patients with megaoesophagus, 10 chagasic patients with megacolon, and 15 control subjects. Basal lower oesophageal sphincter pressure was 20.27+/-1.16 mmHg (mean+/-SEM) in controls as compared wtih 15.16+/-1.53 mmHg in chagasics with megaoesophagus and 14.38+/-1.50 mmHg in chagasics with megacolon. Dose-response studies to intravenous pentagastrin showed that the chagasic patients exhibited a lower sensitivity to the stimulant than did the controls, as demonstrated by shifting of the dose-response curve to the right and higher individual values of the dose for half maximal contraction (D50). No difference was noted between the calculated maximal contraction (Vmax) of oesophageal sphincter of controls and chagasics. These data are compatible with the hypothesis of an interaction between pentagastrin and cholinergic nervous excitation on oesophageal sphincteric smooth muscle.

Adolescent↗
PubMed1979

The effect of the anticonvulsants phenobarbital and diphenylhydantoin on intestinal absorption of calcium.

The effect of anticonvulsant drugs (phenobarbital and diphenylhydantoin) on the metabolic balance of calcium and on its intestinal absorption, as measured by an in situ intraluminal perfusion method, was studied in rats. The administration of these drugs produced: (a) an increase of the fecal excretion of calcium,. (b) a decrease of the intestinal absorption of calcium (45Ca). Both effects were more intense in rats treated with phenobarbital. There is evidence to suggest that the anticonvulsant drugs affect the intestinal mechanism of active transport of calcium.

Animals↗