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Biomedical subjects

A Morelli

Publications and source records attributed to A Morelli.

At least 199 records · Page 11Linked to original sources
PubMed1991

A comparison of nizatidine and ranitidine in the maintenance treatment of duodenal ulcer. A randomized, double blind, multicentre, 2-year study.

UNLABELLED: One hundred and eight patients with an endoscopically documented healed duodenal ulcer (DU) participated to a multicentre, randomized, double-blind, long-term study. The study was planned with the aim to compare the efficacy of nizatidine 150 mg with ranitidine 150 mg in preventing relapse during the 2 years following the DU healing. Fifty four patients were assigned to each treatment. Endoscopic examinations were scheduled at 6, 12 and 24 months. Clinical evaluations were performed every two months. Routine laboratory tests were investigated at the beginning of the study and at each of the scheduled endoscopies. STATISTICS: chi-squared test with Yate's correction, Student's t test for unpaired data, Wilcoxon Rank Sum test and Logrank test. Twenty five patients dropped-out: 15 in the nizatidine and 10 in the ranitidine group. The cumulative relapse rate was 18% for nizatidine and 21% for ranitidine treatment (p:ns). Both drugs resulted safe, as only minor side effects were registered. IN CONCLUSION: nizatidine is as effective and safe as ranitidine in the long-term (2 year) treatment of DU.

Adult↗
PubMed1991

Prolonged manometric investigation of the colon in research on chronic constipation.

We studied the whole colonic motility for 24 hours in controls and in constipated patients. In the patient group we found a significant reduction in the colonic mass movements (6.1 +/- 0.9 vs 2.6 +/- 0.7 controls vs patients, respectively). The constipated patients showed a reduction of the colonic motor activity after the ingestion of a standard meal. Moreover, they showed, compared with controls, a significant reduction of postprandial mass movements. On the other hand we were not able to find the so-called rectal motor complex described by others. In conclusion, we believe that prolonged colonic manometry would become an important step when evaluating the pathophysiology of constipated patients, particularly of those not responding to standard treatment.

Colon↗
PubMed1991

[Parathyroid adenoma and carcinoma. A comparative morphologic study].

A variety of gross, histological and cytological features were analyzed in a comparative study between adenomas and carcinomas of the parathyroid gland. The histological findings more valuable in the differential diagnosis of parathyroid carcinoma were the presence of a thick and irregular capsule infiltrated by the tumor (Fig. 1), broad and irregular intratumoral fibrous septa, and capsular or intratumoral vascular invasion (Table 1). Cytologically, the carcinomas were composed only by chief cells, with a mitotic activity higher than in adenomas, showing the presence of abnormal mitosis (Table 2, Fig 4). Characteristically all carcinomas were composed by a cellular population significantly of greater size than the one observed in adenomas.

Adenoma↗
PubMed1990

Calcium ion-regulated phospholipase C activity in bovine rod outer segments.

Bovine retinal rod outer segment membranes are enriched in a phosphoinositide-specific phosphodiesterase (phospholipase C) activity strictly modulated by free calcium ion concentration. The enzyme(s) was highly active on phosphatidylinositol 4,5-bisphosphate: maximal hydrolysis rate was attained at 10(-5)M Ca2+ and accounted for 91 +/- 4 nmoles hydrolyzed/min/mg of protein. The results support the notion that in vivo the enzyme(s) is regulated so as to conform to the phototransduction events.

Animals↗
PubMed1990

Detection of novel guanine nucleotide binding proteins in bovine retinal rod outer segments.

In the rod outer segment membranes of the bovine retina at least two members of the small molecular weight guanine nucleotide binding proteins were identified by means of the technique of binding radiolabeled GTP to nitrocellulose Western blots of proteins separated by sodium dodecyl sulphate gel electrophoresis. Such proteins, of 23 and 25 kDa, are able to specifically bind guanine nucleotides after denaturing treatments, and are not labeled by pertussis or cholera toxin-catalyzed ADP-ribosylation. The binding site is specific for GTP.

Adenosine Diphosphate Ribose↗
PubMed1990

Manometric evaluation of jejunal limb after total gastrectomy and Roux-Orr anastomosis for gastric cancer.

Total gastrectomy with Roux-Orr anastomosis is frequently performed for gastric cancer. Since intestinal motility of the Roux limb has never been evaluated after this operation, pressure activity was investigated in the Roux limb of ten patients (aged 51-77 years) who had undergone total gastrectomy and Roux-Orr reconstruction. Investigations were carried out during a 6-h fast and 3 h after a 605 kcal mixed meal. During fasting only two patients had activity fronts and these were abnormal. All ten patients displayed non-propagating bursts of contractions and three had discrete clustered contractions and high amplitude jejunal contractions. The fed state was characterized by a severely reduced motor activity pattern and other abnormalities. Total gastrectomy with Roux-Orr anastomoses provokes a relatively severe disturbance in intestinal activity.

Aged↗
PubMed1990

Neurohumoral control of gallbladder motility in healthy subjects and diabetic patients with or without autonomic neuropathy.

Patients affected by diabetes mellitus are reported to have an increased incidence of gallbladder abnormalities. The pathophysiologic mechanisms for this phenomenon are unclear. In the present study ultrasonography was used to determine gallbladder emptying in response to a meal or separate cephalic or hormonal stimulation in 21 diabetic patients and 10 healthy subjects. Gallbladder emptying and refilling after a meal were similar in diabetic patients and healthy subjects. When diabetics were divided according to the presence or absence of cardiac autonomic neuropathy (AN), a significant reduction of gallbladder emptying in response to cephalic stimulation was found in diabetics with AN (P less than 0.01 in comparison with diabetics without AN or healthy subjects). A dose-response curve of gallbladder emptying in response cerulein, a cholecystokinin analog, at concentrations of 0.25, 1, and 4 micrograms/kg/min was evaluated. No differences of gallbladder emptying were found in the three groups of subjects, indicating that gallbladder sensitivity to hormonal stimulation is not changed in diabetic patients with or without AN. Diabetic patients with AN have a significant reduction of gastric acid output and pancreatic polypeptide (PP) secretion in response to cephalic stimulation (P less than 0.05 in comparison with diabetic patients without AN or healthy subjects). Cerulein-induced PP secretion was similar in all three groups of subjects (P greater than 0.05). This study indicates that in diabetic patients with AN, gallbladder emptying as well as gastric acid and PP secretions induced by neural stimulation are markedly reduced in comparison to diabetics without AN.

Adult↗
PubMed1990

Duodenal osmolality drives gallbladder emptying in humans.

The effect of duodenal osmoreceptor stimulation on gallbladder motility was evaluated in 18 normal subjects during intraduodenal infusion of 280, 560 and 840 mosm/liters NaCl solutions. Gallbladder emptying was found to be dose-dependent between 560 and 840 mosm/liter (P less than 0.01 vs basal volume). The effect of duodenal infusion of hypertonic saline on gallbladder emptying was prevented by atropine and partially antagonized by naloxone, indicating that cholinergic and endorphinergic pathways may be involved in regulating this reflex. Since proglumide, a cholecystokinin (CCK) antagonist, did not affect gallbladder emptying induced by hypertonic saline, it seems likely that CCK is not released by increasing duodenal osmolality. A significant reduction in gallbladder volume was obtained when hyperosmolar saline was delivered into the duodenum, whereas no emptying was seen when infused into the gastric antrum or the jejunum, suggesting that osmoreceptors that activate gallbladder emptying are located only in the duodenum. Additionally, all subjects manifested central symptoms (nausea or vomiting) during duodenal infusion of hypertonic saline, suggesting that central mechanisms might be activated by a change in duodenal osmolality. Our data indicate that the osmolality of duodenal contents might regulate gallbladder motility by neural atropine- and naloxone-sensitive pathways.

Adult↗
PubMed1990

Clinical and manometric aspects of diffuse esophageal spasm in a cohort of subjects evaluated for dysphagia and/or chest pain.

Manometric criteria for diffuse esophageal spasm have recently been restated. In this study, a cohort of 358 subjects was evaluated in a gastrointestinal motility laboratory for dysphagia and/or chest pain. Applying the recently proposed criteria of Richter and Castell, 18 subjects (5%) were diagnosed as having DES. Dysphagia was the major complaint (89%), while 44% of patients complained of chest pain and 33% of both symptoms. All patients shared more than 30% simultaneous contractions after wet swallows interspersed with normal peristaltic sequences. Associated manometric findings were repetitive (greater than 3 peaks) contractions (67%), high-amplitude contractions (33%), spontaneous activity (22%), prolonged duration (11%), and lower esophageal sphincter abnormalities (5%). Radiology disclosed significant abnormalities in only 27% of DES patients.

Adult↗
PubMed1990

Duodenojejunal motor activity in patients with chronic dyspeptic symptoms.

We used a low-compliance manometric system to study duodenal and jejunal motility in 33 patients with chronic dyspeptic symptoms and previous negative conventional findings. Nine healthy controls were studied in the same way. Manometric recordings disclosed activity front abnormalities (retrograde or simultaneous propagation) in 45% of patients and an absence of activity fronts in 6%. Moreover, intestinal motor response to a 600-kcal test meal was significantly impaired in the patient group (61.1 +/- 8.1 versus 113.2 +/- 4.2 min, p less than 0.05). We conclude that manometric techniques may be important for investigating patients with chronic dyspepsia and negative findings at previous conventional examinations.

Adult↗
PubMed1990

[Migration].

Explore the source record for details and available documents.

Americas↗
PubMed1990

Effect of omeprazole and high doses of ranitidine on gastric acidity and gastroesophageal reflux in patients with moderate-severe esophagitis.

Thirty to fifty percent of patients with reflux esophagitis fail to heal after treatment with conventional doses of H2-receptor antagonists, whereas omeprazole administration induces more than 90% healing. To investigate the effect of omeprazole and higher-than-presently-recommended doses of H2-blockers, we evaluated gastric acidity and gastroesophageal reflux in 17 patients with severe-moderate esophagitis before and after treatment with 300 mg ranitidine twice daily or 20 mg omeprazole once daily. Three pH-metric studies were performed, in a cross-over design, before and after 8 days of treatment with omeprazole or ranitidine. Both drugs significantly reduced intragastric acidity (p less than 0.001) during both night and day hours. Median hourly 24-h intragastric pH was 1.8 in the basal study, 2.9 after ranitidine, and 3.4 after omeprazole. Intragastric acidity fell from 84.0 mmol/L in the basal study to 14.2 mmol/L (79% inhibition) with ranitidine and 9.3 mmol/L (84% inhibition) with omeprazole. Patients with esophagitis were significantly more exposed to acid than healthy subjects, in both the supine and upright position (p less than 0.01). The time with esophageal pH less than 4 dropped from 23.9% in the basal study to 8.5% with ranitidine and to 7.2% with omeprazole (p less than 0.001). Both drugs significantly reduced esophageal exposure to acid in both the supine and upright positions (p less than 0.001), whereas neither had any effect on esophageal acid clearance.

Adult↗
PubMed1989

Proteins of rod outer segments of toad retina: binding with calmodulin and with GTP.

Proteins of purified rod outer segments from toad retina were analysed by electrophoresis on polyacrylamide gel containing sodium dodecyl sulfate. The binding of proteins with calmodulin and with guanosine triphosphate was studied by electroblotting the proteins resolved by electrophoresis onto nitrocellulose sheets and by incubating the blots with labelled ligands. The results indicate that rod outer segments from toad retina contain nine proteins which bind to calmodulin and one protein, different from transducin, that binds to guanosine triphosphate.

Animals↗
PubMed1989

Modulation of erythrocyte Ca2+-ATPase by selective calpain cleavage of the calmodulin-binding domain.

The activity of the membrane-bound and the purified erythrocyte Ca2+-ATPase in the absence of calmodulin was stimulated by calpain digestion but could be further increased to maximal levels by calmodulin (CaM). Thus, CaM sensitivity was retained by the digested ATPase, at least at short times of incubation. In membranes digested at higher temperatures and in the purified ATPase digested at higher calpain/ATPase ratios, the ATPase became fully activated. The membrane-bound and the purified 138-kDa ATPase were converted by calpain to a fragment of approximately 124 kDa which still bound CaM and could be isolated on CaM columns when proteolysis occurred slowly but not when it occurred rapidly. Carboxypeptidase digestion of the purified enzyme and of its fragment of about 124 kDa has shown that calpain attacked the CaM-binding domain near the C terminus of the ATPase. This has also been supported by digestion of the purified enzyme and of its fragment of about 124 kDa. A first cut occurred in the middle of the domain producing a fragment of about 14 kDa and a (CaM-binding) fragment of about 124 kDa. A second cut closer to the N terminus of the domain also produced a fragment of about 124 kDa and accounted for the loss of CaM binding at prolonged times of incubation of the ATPase with calpain.

Amino Acid Sequence↗
PubMed1989

"In situ" characterization of guanine nucleotide-binding properties of erythrocyte membranes.

Unsealed membranes from human erythrocytes bind GTP and GTP analogs according to first order kinetics, a single rate constant being observed. With [35S]GTP gamma S this is 0.15 +/- 0.2 min-1. Treatment of the membranes with detergents decreases binding considerably. Scatchard plots reveal uncomplicated patterns of ligand association, with Kd values of 10.2 +/- 2.3 nM [35S]GTP gamma S, of 18.2 +/- 4.3 nM [alpha-32P]GTP and of 28.6 +/- 3.5 nM [alpha-32P]GDP, respectively. The stoichiometry with the three ligands is strictly comparable, i.e. 65 +/- 7 picomoles/mg of membrane protein. Binding of each labeled nucleotide is competitively inhibited by the other two unlabeled ligands, the inhibition constants being very close to the corresponding Kd values. Metabolic depletion and subsequent repletion of intact erythrocytes result in membrane preparations still active in guanine nucleotide binding, with unmodified Kd values. However, the stoichiometry falls to 35 picomoles/mg protein with the "depleted" erythrocyte membranes and regains higher values (50 picomoles/mg protein) with the "repleted" cell membranes. Accordingly, the "in situ" characterization of guanine nucleotide-binding properties of erythrocyte membranes seems to represent a new tool for monitoring the metabolic state of intact erythrocytes.

Binding, Competitive↗