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Biomedical subjects

W Padovan

Publications and source records attributed to W Padovan.

12 recordsLinked to original sources
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↗
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↗
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

Faecal methylamine in normal and uraemic subjects.

1. A ninhydrin-reacting substance seen during ion-exchange chromatography of faecal dialysate obtained in vivo from normal and uraemic subjects has been isolated and identified as methylamine. 2. Faecal dialysate concentrations of methylamine were higher in uraemic subjects and were related to the degree of renal impairment (P less than 0.05). 3. Methylamine concentrations in faecal dialysate and centrifugate were not significantly different.

Centrifugation↗
PubMed1977

Gastric secretory and motility studies in chronic chagasic patients.

In Chagas' disease, the degeneration of the nerve cells of the intramural parasympathetic ganglia of the stomach causes a wide range of motor and secretory disturbances of the organ. To assess and to correlate the alterations of these two gastric functions, electromanometric and secretory studies were performed in 22 chagasic patients and in 12 control individuals. The gastric antrum electromanometric records were carried out in basal conditions and under the stimulation of methacholine chloride (Mecholyl). Gastric secretory studies were carried out in two sessions with a Kay's test: in the first, with the test alone; in the second, associated with bethanechol chloride (Urecholine). The chagasic patients were divided into two groups according to their gastric motor response to methacholine. It was concluded that the parasympathetic denervation in Chagas' disease changes both acid and pepsin secretions in the same direction but that as the disease worsens, the responsiveness of pepsin secretion to cholinergic action tends to disappear earlier than that of acid secretion.

Adult↗
PubMed1976

Limitations of ultracentrifugation and in vivo dialysis as methods of stool analysis.

Extracellular stool fluid has been sampled by in vivo dialysis, in vitro dialysis, and high speed centrifugation. Detailed comparisons of amino acids and electrolytes have been made between each fluid; normal values and significant differences are summarized. Evidence is provided which suggests that there is release of intracellular contents during normal handling of stool in the laboratory. The amino acids which display the greatest differences between centrifugate and dialysate from given stool specimens are those which are liberated by ultrasonication or aerobic incubation of stool. Factors affecting the chemical stability of stool are discussed. In most circumstances in vivo dialysis would seem to provide the closest approximation to extracellular fluid, providing the faeces remain in the descending colon or rectum for at least two hours.

Air↗
PubMed1975

Quantitative method for estimating fecal amino acids.

We describe a method for quantitatively estimating 24 ninhydrin-reacting substances, including the commoner amino acids, in fecal dialysate prepared from ingested dialysis bags retrieved from fresh stool. It is accurate to 2 mumol of alpha-amino nitrogen per liter of fecal dialysate, and for most substances recovery of added standards is 100%. It involves dilution, ultrafiltration, and automated ion-exchange column chromatography of the dialysate. Some normal values are provided.

Adult↗
PubMedDate not supplied

Gastric emptying of lactose and glucose-galactose in patients with low intestinal lactase activity.

To test the hypothesis that in subjects with low intestinal lactase activity (LLA) lactose solutions leaves the stomach at an abnormally fast rate, we have measured the gastric emptying rate of solutions of lactose and glucose-galactose in patients with LLA (n = 9) and in control subjects with high intestinal lactase levels (n = 7) as proved by the assay of disaccharidases in specimens of intestinal mucosa. The volume of the test meals was 300 ml. Lactose solutions contain 50 g of disaccharide and glucose-galactose solutions contain 25 g of each monosaccharide. The volumes remaining in the stomach at different times after the intragastric instillation of the test meals were estimated by the double sampling test meal. In the control group, minor differences between lactose and glucose-galactose gastric emptying rates was found. By contrast, in LLA patients, the lactose meal left the stomach at a significantly faster rate than the glucose-galactose test meal. These findings support previous evidence obtained in patients with putatively low intestinal lactase activity and are consistent with the view that duodenal osmoreceptors, whose excitation results in inhibition of gastric emptying, lie deeper than the disaccharidases in intestinal mucosa. Thus, incomplete hydrolysis of lactose results in a faster than normal gastric emptying rate of the sugar and this may contribute to the symptoms found in LLA patients after milk ingestion.

Adult↗
PubMedDate not supplied

[Lactose malabsorption in adult patients at the Hospital das Clínicas de Ribeirão Preto].

A standard oral lactose tolerance test (LTT) was performed in 32 white and 18 non-white hospitalized Brazilian adults. A flat LTT was found in 22 (68,75%) white and in 17 (97,45%) non-white patients indicating a 78% overall rate of lactose malabsorption, Both lactose absorbers and malabsorbers showed a modal milk ingestion of less than a 1 glass/day. Symptoms related to milk consumption or lactose administration were more common among lactose malabsorbers. Estimations of disaccharidase activity in intestinal mucosa specimens obtained by peroral biopsy in 28 patients confirmed a high prevalence of lactose deficiency, and disclosed only one false result, in the patient with a flat LTT and high intestinal lactase levels.

Adolescent↗
PubMedDate not supplied

[Hydrochloric acid and pepsin secretion and the structure of the stomach in experimental protein malnutrition].

In adult male rats submitted during 12 weeks to a diet containing 2,5% protein the amount of hydrochloric acid and of pepsin was determined and the macro and microscopic morphology of the stomach was studied. A group fed a diet containing 20% protein was used as control. The statistical analysis of the data obtained showed that the apparent differences in the secretion of acid as well as pepsin could be attributed to the different body weights of the two groups. The morphological examination showed papillomas, frequently ulcerated occurring in the forestomach of the undernourished rats. In these areas, histological examination revealed hyperkeratosis and acanthosis. The glandular epithelium showed neither macroscopic nor microscopic alterations.

Animals↗