Biomedical subjects

L Marzio

Publications and source records attributed to L Marzio.

At least 73 records · Page 4Linked to original sources

PubMed1991

Influence of physical activity on gastric emptying of liquids in normal human subjects.

Liquid gastric emptying has been evaluated in 17 normal human subjects during basal conditions, after mild physical stress at 50% of the maximum predictable heart rate, and after maximal physical stress at 70% maximum heart rate. Each subject exercised on a treadmill for 30 min, its speed and inclination varied in order to obtain the desired heart rate. Immediately after the exercise, 400 ml of mineral water were drunk by each subject. Gastric emptying was evaluated by real-time ultrasonography (11 subjects) and scintigraphy (six subjects) through previously described methods. The results show similar data with both techniques. Gastric emptying of the water, considered either as reduction in gastric measurements at ultrasonography or decay in radioactivity in the region of interest corresponding to the stomach at scintigraphy, follows a linear relationship under basal conditions and during physical stress. Compared with basal conditions, gastric emptying of water after maximal stress was prolonged; after mild stress, gastric emptying of the water was accelerated. These findings may support the common belief that mild physical activity favors the digestive process.

Adult↗

PubMed1990

Effects of cimetropium bromide on gallbladder contraction in response to oral and intraduodenal olive oil.

To evaluate the influence of the stomach and the cholinergic system on gallbladder contraction induced by physiological stimuli, the reduction in gallbladder volume in 7 healthy volunteers has been studied by real-time ultrasonography after the oral and intraduodenal administration of olive oil, preceded by pretreatment with cimetropium bromide or placebo. After an overnight fast, each subject swallowed 50 ml olive oil or it was administered through a naso-duodenal tube in the proximal duodenum. Cimetropium bromide 5 mg or placebo was given intravenously under double-blind control. After the placebo pretreatment, gallbladder contraction was greater and faster after intraduodenal oil than after oral oil. Cimetropium bromide decreased the extent, velocity and duration of gallbladder contraction induced by intraduodenal olive oil but it only reduced the velocity of the contraction induced by oil given orally. It is concluded that in normal human subjects the stomach modulates the extent and velocity of postprandial gallbladder contraction and that anticholinergic agents antagonize the gastric and duodenal phases of the response of the gallbladder to a meal.

Administration, Oral↗

PubMed1990

Dopamine interrupts gastrointestinal fed motility pattern in humans. Effect on motilin and somatostatin blood levels.

The aim of this study was to investigate the hypothesis that during the postprandial period in humans, dopamine interrupts the gastrointestinal motility pattern through a mechanism that is peptide-mediated. Fourteen normal human subjects were studied by means of intestinal manometry. After recording two consecutive migrating motor complexes a 900-kcal solid-liquid meal was given. In eight subjects 30 min after the meal, placebo or dopamine (5 micrograms/kg/min) was infused for 15 min and then the recording continued for 120 min. In the remaining six subjects dopamine was administered twice with a 90-min interval in between. In three subjects the first dopamine infusion after the meal was preceded by treatment with placebo, the second by domperidone (20 mg intravenous as bolus), in the other three subjects domperidone was given before the first dopamine infusion. Blood samples for the determination of somatostatin and motilin were drawn basally, during, and immediately after dopamine in seven subjects. The results show that dopamine interrupts the fed motility pattern, inhibiting the high antral waves, and activates a duodenal phase III of migrating motor complexes. The pretreatment with domperidone completely prevented the dopamine effect. Plasma levels of motilin increased significantly during dopamine, while somatostatin blood levels did not change. These findings support the hypothesis that a dopaminergic mechanism may modulate the cycling of duodenal motor complex in humans.

Adult↗

PubMed1990

Effect of somatostatin on gallbladder volume and small intestinal motor activity in humans.

The effects of different doses of somatostatin (36, 180, 360 pmol/kg/h) on the motor patterns of the duodenum and on gallbladder volume in the postprandial period were evaluated. Gallbladder volume and small intestinal motor activity were monitored simultaneously in 9 normal subjects. Gallbladder volume was measured every 5 min throughout the study by real-time ultrasonography while intestinal motility was recorded manometrically by means of a low-compliance pneumohydraulic system. On day 1, the response of the gallbladder to a 972-kcal test meal was evaluated ultrasonographically to assure a normal response. On day 2, at least 2 consecutive phase III complexes of the interdigestive motor cycle were recorded. Gallbladder volume varied cyclically during the interdigestive motor cycle, with the minimum value late in phase II and the maximum early in phase I (p less than 0.01); the test meal was then administered. Following the induction of a typical pattern of postprandial motility, somatostatin infusion was started and continued for 150 min. Somatostatin, at the 180- and 360-pmol/kg/h doses, interrupted the fed pattern and induced consecutive bursts of propagated clustered activity. The characteristics of these somatostatin-induced motor patterns were similar to the spontaneous phase III of the interdigestive motor cycle. An initial reduction in gallbladder volume cycle. An initial reduction in gallbladder volume followed the ingestion of the meal; during somatostatin infusion, gallbladder volume increased to values greater than fasting values and varied cyclically with minimum values before the second episode of propagated clustered activity. These results show that somatostatin interrupts the fed pattern and elicits consecutive clusters of propagated motor activity in the duodenum that are coordinated with cyclic fluctuations in gallbladder volume.

Adult↗

PubMed1990

Glutathione peroxidase, glutathione reductase and glutathione transferase activities in the human artery, vein and heart.

The continuous exposure to blood components, including prooxidants, makes the blood vessel wall susceptible to oxidative stress and free radical mediated reactions (Henning and Chow, 1988; Stamm et al., 1989; Halliwell and Gutteridge, 1984). Free radicals can be produced extracellularly via the respiratory bursts of activated neutrophils, or intracellularly, via oxidation of hypoxanthine by xanthine oxidase (Henning and Chow, 1988; Stamm et al., 1989; Rubanyi, 1988). Microsomal enzymes such as lipoxygenase and cyclooxygenase may also be a source of reactive species of oxygen (Henning and Chow, 1988; Stamm et al., 1989; Rubanyi, 1988; Mason et al., 1980). It has been proposed that free radicals are involved in the initiation and progression of various cardiovascular diseases including arteriosclerosis (Henning and Chow, 1988; Stamm et al., 1989; Yagi, 1988; Jürgens et al., 1987). Thus the adequacy of the defence systems against free radicals is critical for the susceptibility of blood vessel wall to oxidative damage. Among the enzymatic systems capable of protecting the cell against oxidative injury, selenium dependent glutathione peroxidase (Se-GSH-px), glutatione reductase (GSSG-rx) and glutathione transferase (GST) play a crucial role (Flohe' et al., 1976; Mannervik and Danielson, 1988). Using glutathione (GSH) as a cofactor, Se-GSH-px reduces H2O2 to water and organic hydroperoxides to the corresponding alcohols (Flohe' et al., 1976). This reaction leads to conversion of GSH into its oxidized form (GSSG). In the presence of NADPH, GSSG-rx is able to reduce the oxidized glutathione.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Sodium cromoglycate in the treatment of eosinophilic gastroenteritis.

Two patients suffering from eosinophilic gastroenteritis (EG) were treated with sodium cromoglycate (SCG). Before treatment they showed enteric and cutaneous symptoms, such as abdominal pain, nausea, vomiting, diarrhoea and recurrent urticaria and angioedema. The histological findings were a notable amount of eosinophilic infiltration in the lamina propria and gastric glands, a villous shortening and thickening and weak eosinophilic inflammation in the duodenum. The patients were treated with 300 mg SCG, 4 times daily, for 4/5 months. During treatment, the clinical symptoms disappeared and at the end of treatment a reduced inflammation with an almost complete decrease of eosinophilic infiltration was observed. The results provide evidence of SCG efficacy in the treatment of EG and suggest its employment as an alternative to the steroids commonly used in EG.

Adult↗

PubMed1990

Altered smooth muscle function in worm-free gut regions of Trichinella-infected rats.

We have extended a recent study demonstrating increased contractility of jejunal smooth muscle of rats infected with the nematode parasite Trichinella spiralis, the primary habitat of which is the jejunum. In this study, muscle from the worm-free ileum of infected rats showed decreased contractility compared with control, illustrating regional differences in muscle responses to the infection. However, in jejunal muscle from worm-free segments that had been excluded from the rest of the gut before the infection, we observed increased tension generation, suggesting a systemic mechanism. To evaluate whether the changes in jejunal muscle were due to the host's inflammatory reaction, the effect of beta-methasone was examined. In a dose of 3.0 mg/kg sc daily, the steroid abolished the increase in myeloperoxidase activity associated with the infection and attenuated the increased tension generation in jejunal muscle from Trichinella-infected rats. These results support the hypothesis that alterations in intestinal smooth muscle function in this model do not require the presence of the parasite in the lumen and are mediated by the host's inflammatory reaction.

Animals↗

PubMed1989

Comparative study of the effects of cimetropium bromide and atropine on human esophageal motor functions.

The effects of atropine and cimetropium bromide, a new antimuscarinic compound with strong spasmolytic properties, were studied on human esophageal motility. Twenty healthy subjects underwent esophageal manometry with continuous monitoring of lower esophageal sphincter pressure (LESP), and of amplitude, duration and velocity of contractions of the esophageal body. After a 30-min basal period, atropine (12 micrograms/kg) or cimetropium (5 mg) were administered as an intravenous bolus in a cross-over random manner and the recording was continued for another 60 min. Twenty minutes after injection, atropine and cimetropium decreased maximally, in a similar extent, both the amplitude of contractions of the esophageal body (-65% of the basal values) and the LESP (-30% of the basal values). The duration and propagation velocity of the esophageal contractions did not change significantly after both drugs. Sixty minutes after injection of cimetropium, the amplitude of contractions of the esophageal body and LESP returned to basal values while atropine still reduced both variables. These findings indicate that cimetropium bromide has an inhibitory effect on LESP and on the amplitude of contractions of the esophageal body similar to atropine, but its action lasts less time.

Adult↗

PubMed1989

Mouth-to-cecum transit time in patients affected by chronic constipation: effect of glucomannan.

Mouth-to-cecum transit time was studied in 13 patients affected by chronic idiopathic constipation and 18 control subjects matched with the constipation group for age, sex, and dietary habits. In a preliminary investigation, all patients showed a prolonged whole gut (oroanal) transit time as measured with radiopaque markers. Mouth-to-cecum transit time was studied through the serial determination of breath H2 after administration of 12 g lactulose diluted in 120 ml water. Breath H2 was measured with a gas analyzer and was determined in parts per million (ppm). Breath H2 after lactulose was also determined in the group with constipation after a 10-day diet that included either glucomannan (1 g tid orally) or placebo administered in a double-blind manner. The results show a statistically significant increase in mouth-to-cecum transit time in the group with constipation, compared with controls, and a return to within the normal range after the 10-day treatment with glucomannan. With placebo, no difference in transit time was noted. We therefore suggest that chronic idiopathic constipation is a disease that involves the whole gut.

Breath Tests↗

PubMed1989

Evaluation of the use of ultrasonography in the study of liquid gastric emptying.

Gastric emptying of two different test liquid meals (500 ml isotonic saline and 500 ml skimmed milk, 1.8% fat) has been measured in 10 (saline) and in 19 (milk) normal volunteers by means of real-time ultrasonography (RUS) and scintigraphy, employed simultaneously. In each subject, saline and milk contained 37 MBq of diethylenetriaminopentacetic acid (DPTA) marked with 99mTc. Determinations were made thereafter every 5 min up to 45 min with saline and every 30 min up to a maximum of 220 min with milk. The determination of gastric emptying by RUS was obtained indirectly through the measurement of gastric dimensions, with a single scan performed at the epigastrium, while the subject was kept in a standing position. At each observation, the percent decrease of gastric measurements and the decay in radioactivity over the gastric region were calculated, blind, by two independent examiners. Linear regression and correlation coefficient were subsequently computed for gastric measurements and decay in radioactivity. The results show that the values obtained with RUS do not differ grossly from the ones obtained with scintigraphy. This suggests that the ultrasonographic determination of gastric dimensions with a single section of the stomach may be a valuable method for use in the evaluation of gastric emptying of liquids.

Adult↗

PubMed1988

Effect of ischemia and reperfusion on antioxidant enzymes and mitochondrial inner membrane proteins in perfused rat heart.

Experiments were performed to investigate the effects of 60 min severe global ischemia followed by 30 min reperfusion on the antioxidant enzymatic system in the isolated perfused rat heart. Ischemia induced a significant increase of cytoplasmic and mitochondrial selenium-dependent glutathione peroxidase (EC 1.11.1.9) activity. In reperfused hearts, only the mitochondrial form showed a further significant increase. Glutathione reductase (EC 1.6.4.2) was increased in ischemic hearts, whilst the reperfused hearts showed a decrease towards the level found in aerobic hearts. Mitochondrial superoxide dismutase (EC 1.15.1.1) activity was depressed in ischemic as well as in reperfused hearts, though the cytoplasmic form was unmodified. Catalase (EC 1.11.1.6), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and glutathione transferase (EC 2.5.1.18) activities were unchanged throughout the experiment. Ischemia and reperfusion induced a significant fall in tissue-reduced glutathione content concomitant with an increase of its oxidized form. We have also studied the mitochondrial inner membrane proteins for both molecular weight, with Coomassie blue, and thiol status, with monobromobimane stain, using a sodium dodecyl sulfate polyacrylamide gel electrophoresis technique. Neither ischemia nor reperfusion effected any relevant modification of the molecular weight of the mitochondrial inner-membrane proteins either in the presence or absence of a reducing agent. However, two of these proteins with an apparent molecular weight of 52,0000 and 12,000 showed a decrease in the monobromobimane stain, probably due to the oxidation of their thiol groups.

Animals↗

PubMed1988

Gallbladder kinetics in obese patients. Effect of a regular meal and low-calorie meal.

Gallbladder contractility has been studied in 21 obese patients (greater than 130% ideal weight) and 30 nonobese subjects before and at regular intervals after the administration of a regular solid-liquid meal, and after a low-calorie, low-fat meal used conventionally for weight-loss purposes (Modifast). Gallbladder volume was determined by means of real-time ultrasonography, using a linear array scanner with a 3.5 MHZ probe. In seven of the obese patients, gallbladder contractility was also evaluated after a 10-day regimen with Modifast. The obese group showed a statistically significant greater gallbladder fasting volume and blunted contractility than controls both after the ordinary and the low-calorie meal. The 10-day low-calorie regimen was associated with a statistically significant increment in fasting gallbladder volume, while the percent volume reduction after Modifast did not change. It is suggested that, in addition to metabolic factors, gallbladder hypocontractility in the obese may contribute to the high incidence of cholesterol gallstones noted in these patients. A low-calorie, low-fat diet augmenting gallbladder volume may favor bile stasis and therefore the likelihood of developing gallstones.

Adult↗

PubMed1988

Effect of ketanserin, a selective antiserotoninergic drug, on human anal canal pressure.

The effect of Ketanserin, a new antiserotoninergic drug, on human anal pressure in vivo was investigated. Anal pressure was recorded continuously in 14 normal subjects by a low-compliance water perfused probe with two recording points at the sphincter level. After a 30-min basal tracing Ketanserin (10 mg IV as bolus) or placebo was administered in a double blind manner, and the recording continued for 1 h. The results show that Ketanserin induced a 30% fall in anal pressure soon after its administration which was statistically significant when compared with the placebo (p less than 0.01). This effect lasted up to 40 min of recording and was followed by a return to control values within 1 h.

Adult↗

PubMed1988

Gallbladder contraction and its relationship to interdigestive duodenal motor activity in normal human subjects.

Gallbladder volume and interdigestive gastric and duodenal motor activity were evaluated simultaneously in 12 normal subjects. After overnight fasting, gallbladder volume was monitored every 4 min in each subject by means of real-time ultrasonography, and gastroduodenal motor activity was measured by means of a probe consisting of three polyvinyl catheters with one side opening for each catheter, placed 15 cm apart and constantly perfused with deionized water. Real-time ultrasonography and intestinal manometry were performed by different investigators and continued until at least two consecutive spontaneous phase III activities of migrating motor complexes were observed. The results show a cyclic variation of gallbladder volume, which reached its minimum value before the end of phase II in the proximal duodenum and its maximum in early phase II, 25 min after the beginning of phase III. These results suggest that there is a relationship between the cyclic gallbladder volume changes, which occur during fasting in humans, and with the various phases of duodenal migrating motor complex.

Digestion↗

PubMed1988

Cisapride versus placebo in reflux esophagitis. A multicenter double-blind trial.

In a 6 to 12-week double-blind trial, the effect of cisapride (10 mg q.i.d.) was compared with that of placebo in 63 patients with esophagitis confirmed by endoscopy and/or biopsy. In only one patient (3%) in the cisapride group but in 43% of the placebo patients (p = 0.001), symptoms had not improved after 6 weeks. Forty patients continued treatment until week 12. At that time, control endoscopy showed a significantly (p = 0.005) higher rate of healing (no erosions, ulcers, or bleeding mucosa) in the cisapride patients (63%) than in the placebo patients (12%). At week 12, only three of the 21 cisapride patients still had moderate reflux symptoms, whereas eight of the 19 placebo patients had moderate or severe symptoms (p less than 0.05). Cisapride patients also took significantly (p less than 0.001) less antacids during the trial. These results show that cisapride, 10 mg q.i.d., heals esophagitis lesions and greatly reduces associated symptoms. The treatment was well tolerated.

Adult↗

PubMed1988

Gallbladder emptying in duodenal ulcer patients having undergone Billroth II gastrectomy.

There is an increased incidence of gallstones in patients who have undergone Billroth II (BII) gastrectomy for duodenal ulcer. To explore the mechanisms underlying this, we examined changes in gallbladder volume induced by a meal and by intravenous administration of cerulein, in 13 BII patients and in 13 normal subjects. Gallbladder volume was measured by real-time ultrasonography. In the fasting state, gallbladder volumes were significantly larger in BII patients than in controls. The percent decrease in gallbladder volume after the meal was significantly less and maximum volume reduction observed throughout the study occurred sooner in BII patients than in controls. In contrast, the kinetics and magnitude of the reduction in gallbladder volume induced by cerulein were similar in the two groups. These findings suggest that the altered gallbladder response to a meal is due to impaired postprandial stimulation of gallbladder following BII gastrojejunostomy.

Adult↗

PubMed1987

Mechanism of isoproterenol-induced angina pectoris in patients with obstructive hypertrophic cardiomyopathy and normal coronary arteries.

In 14 patients with obstructive hypertrophic cardiomyopathy and angiographically normal coronary arteries, 8 with angina (group B) and 6 without (group A), the effects of intravenous isoproterenol, 2 to 4 micrograms/min, followed by intravenous propranolol, 0.2 mg/kg, were studied. An intraventricular systolic gradient less than 50 mm Hg, high-quality echocardiograms and cineangiograms and high-fidelity pressure tracings were selection criteria. Hemodynamic and metabolic variables were assessed during basal conditions, after 5 minutes of isoproterenol infusion or at angina and ST-segment depression, and 5 and 10 minutes after intravenous propranolol infusion. Isoproterenol increased the intraventricular systolic gradient more significantly in group B than in group A (102.4 +/- 8.3 vs 52.2 +/- 8.2, p less than 0.0001). Group B also had higher left ventricular end-diastolic pressure (32.5 +/- 3.9 vs 20.2 +/- 5.7), lower mean arterial pressure (69.7 +/- 3.5 vs 84.7 +/- 4.8) and a smaller increase in coronary sinus flow (176.1 +/- 9.2 vs 261.5 +/- 33.9, all p less than 0.0001), concomitant with lactate release and ST-segment depression. Propranolol promptly reversed hemodynamic and metabolic changes caused by isoproterenol, except for a further coronary sinus flow increase (from 176.1 +/- 9.2 to 219 +/- 14.2 ml/min, p less than 0.001), and heart rate decrease below basal values (57.8 +/- 7.5 vs 79.9 +/- 9.8 beats/min, p less than 0.001) in group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

PubMed1987

Effect of cholinergic agonists and antagonists on gallbladder volume in fasting man.

The effect of direct cholinergic stimulation and blockade on gallbladder volume, determined by real-time ultrasonography (RUS), was evaluated in twenty normal, fasting subjects. Eleven subjects received atropine sulphate or placebo and 9 subjects a series of 3 injection of prostigmine, bethanechol or placebo, randomly assigned, at intervals of 24 h. RUS was performed under basal conditions after fasting for 12 h and every 5 min after drug injection up to 45 min in the atropine study and up to 60 min after prostigmine and bethanechol. There was no significant variation from fasting gallbladder volume after placebo in either group. After atropine sulphate gallbladder volume at first decreased and then significantly increased. With bethanechol and prostigmine, the volume fell significantly to a trough after 30 to 35 min, and then it returned to the basal value within 60 min. It is suggested that cholinergic mediation is involved in maintaining fasting tone in the gallbladder and that cholinergic stimulation causes contraction of the gallbladder by a direct effect.

Adult↗