Biomedical subjects

G Basilisco

Publications and source records attributed to G Basilisco.

At least 19 recordsLinked to original sources

PubMed2001

Effect of continuous rectal distention on anal resting pressure.

PURPOSE: Intermittent distention of the rectum induces internal anal sphincter relaxation, but whether continuous rectal distention might affect the resting pressure of the anal canal and the frequency of internal anal sphincter relaxations has not yet been investigated. The aim of this study was to record anal pressure under resting conditions and at two levels of continuous rectal distention. METHODS: Anal pressure was recorded by means of water-perfused catheters under resting conditions and at two levels of rectal distention controlled by an electronic barostat in eight healthy subjects. RESULTS: Continuous rectal distention did not significantly change mean anal resting pressure, but it did significantly decrease the amplitude of ultraslow waves (from 29 +/- 9 mmHg under resting conditions to 23 +/- 6 and 21 +/- 3 mmHg during lesser and greater rectal distention; P = 0.017 and P = 0.012, respectively) and increase the frequency of internal anal sphincter relaxations (from 1.3 +/- 1.3/hour under resting conditions to 8.8 +/- 4.3/hour and 11.0 +/- 4.8/hour during lesser and greater distention; P = 0.012 in both comparisons). CONCLUSIONS: The resting pressure of the anal canal is maintained during continuous rectal distention. The decreased amplitude of ultraslow waves and increased frequency of the internal anal sphincter relaxations induced by rectal distention reveal a complex functional relationship between the rectum and the anal canal.

Adult↗

PubMed2000

Autonomic control of heart period in duodenal ulcer patients insights from spectral analysis of heart rate variability.

Beyond the fundamental pathogenetic importance of Helicobacter Pylori a possible additional role of vagal innervation in favouring or modulating the clinical history of duodenal ulcer (DU) has been suggested by old studies employing invasive methodologies. Aim of this study was to assess whether vagal prevalence in autonomic modulation was present in healed DU patients (n=20) as compared to controls,(n=50), using a validated non-invasive methodology, based on spectral analysis of cardiovascular variability. This approach provides markers of the sympathetic and vagal modulations of the SA node, respectively by way of the normalized low frequency (LF(RR)) and high frequency (HF(RR)) components of RR interval variability; LF/HF ratio furnishes a marker of sympatho-vagal balance. In addition, sham feeding (SF) provided a means to assess, in DU patients, neurally mediated acid secretion, as the SF acid output (SAO) to basal acid output (BAO) ratio (SAO/BAO). Results showed that LF(RR) was smaller in DU patients than in controls (40.3+/-3.9 vs. 52.3+/-2.3 normalized units, nu; P<0.05). On the contrary, HF(RR) was greater (52.1+/-3.7 vs. 35.7+/-2.3 nu; P<0.05). Conversely the LF component of SAP variability, a marker of sympathetic vasomotor modulations, and the index alpha, a measure of baroreflex control of the SA node, as well as respiratory patterns, were similar in the two groups. SAO/BAO ratio was significantly correlated with markers of autonomic control of the SA node (r = -0.67, P<0.0083 with HF(RR)). In conclusion results suggest an enhanced vagal modulation of heart period in DU patients at rest, that appears linked to indices of neurally mediated gastric acid secretion response.

Adult↗

PubMed2000

Sensations induced by medium and long chain triglycerides: role of gastric tone and hormones.

BACKGROUND: The relative roles of gastric relaxation and the neuroendocrine signals released by the small intestine in the perception of nutrient induced sensations are controversial. The different effects of long chain (LCT) and medium chain (MCT) triglyceride ingestion on perception, gastric relaxation, and hormonal release may help to elucidate the mechanisms underlying nutrient induced sensations. AIMS: To compare the effects of intraduodenal LCT and MCT infusions on perception, gastric tone, and plasma gut hormone levels in healthy subjects. SUBJECTS: Nine fasting healthy volunteers. METHODS: The subjects received duodenal infusions of saline followed by LCTs and MCTs in a randomised order on two different days. The sensations were rated on a visual analogue scale. Gastric tone was measured using a barostat, and plasma gut hormone levels by radioimmunoassay. RESULTS: LCT infusion increased satiation scores, reduced gastric tone, and increased the levels of plasma cholecystokinin, gastric inhibitory polypeptide, neurotensin, and pancreatic polypeptide. MCT infusion reduced gastric tone but did not significantly affect perception or plasma gut hormone levels. LCTs produced greater gastric relaxation than MCTs. CONCLUSIONS: The satiation induced by intraduodenal LCT infusion seems to involve changes in gastric tone and plasma gut hormone levels. The gastric relaxation induced by MCT infusion, together with the absence of any significant change in satiation scores and plasma hormone levels, suggests that, at least up to a certain level, gastric relaxation is not sufficient to induce satiation and that nutrient induced gastric relaxation may occur through cholecystokinin independent mechanisms.

Adult↗

PubMed1999

Intraesophageal pH monitoring during acid infusion in patients with systemic sclerosis.

Incidental clinical observations suggest that buffering substances may accumulate in the distal esophagus of patients with systemic sclerosis. The aim of our study was to assess if the buffering capacity of the intraesophageal milieu is increased in patients with systemic sclerosis and if this effect can be correlated to some pathophysiological aspects of the disease. We recorded intraesophageal pH before and during a 10-min intraesophageal infusion of acid (HCl 0.01 N, 1 ml/min), as well as esophageal motility and clearance function, in 16 patients with systemic sclerosis and 10 healthy subjects. Esophageal buffering capacity expressed as the area under the curve of intraesophageal pH during acid infusion was significantly higher in the patients than in the controls, and this variable was directly correlated with esophageal clearing time. In conclusion, esophageal buffering capacity is increased in patients with systemic sclerosis and is possibly the consequence of the accumulation of buffering substances in the distal esophagus.

Acids↗

PubMed1999

Postprandial gut peptide plasma levels in women with idiopathic slow-transit constipation.

BACKGROUND: As abnormalities of circulating gut regulatory peptides may have pathogenetic relevance in chronic idiopathic slow-transit constipation, we measured fasting and postprandial levels of plasma pancreatic polypeptide, motilin, cholecystokinin, neurotensin, and somatostatin in women with the disease. Results were compared with those of women with normal bowel habits. METHODS: Eight women with slow-transit constipation and 10 healthy women were studied. Blood samples were taken at regular intervals in fasting conditions and for 3 h after a standard solid-liquid meal (550 kcal). Gut peptide plasma levels were measured with a radioimmunoassay. RESULTS: Fasting gut peptide levels and postprandial pancreatic polypeptide responses were normal in constipated patients, in whom, however, motilin levels did not increase after the meal, and postprandial concentration-time curves of cholecystokinin, neurotensin, and somatostatin were delayed. Mean +/- standard error of the mean peak times in patients and in controls were, respectively, 99 +/- 14.7 and 46 +/- 4.1 min (P < 0.01, Mann-Whitney test) for cholecystokinin, 135 +/- 9.8 and 60 +/- 3.9 min (P < 0.01) for neurotensin, and 111 +/- 17.7 and 51 +/- 6.0 min (P < 0.05) for somatostatin. CONCLUSIONS: Patients with slow-transit constipation have abnormal postprandial patterns of motilin, cholecystokinin, neurotensin, and somatostatin.

Adult↗

PubMed1999

Local regulation of postprandial motor responses in ileal pouches.

BACKGROUND: Local mechanisms are involved in the postprandial regulation of ileal tone in healthy subjects, but whether these mechanisms affect the postprandial tonic response of ileal pouches has not yet been investigated. AIMS: To study the effect of a meal on pouch tone and phasic motor activity in patients with gut continuity or ileostomy and, in the latter group, the effect of a pouch perfusion with chyme or saline. PATIENTS: Twenty patients with ileal pouches: 10 with gut continuity and 10 with ileostomy. METHODS: Pouch tone and the frequency of phasic volume events were recorded with a barostat under fasting and postprandial conditions and after perfusion of the isolated pouch with chyme or saline. RESULTS: The meal increased pouch tone and the frequency of phasic volume events in the patients with gut continuity, but not in those with ileostomy. Pouch perfusion with chyme induced a greater increase in pouch tone than saline. CONCLUSIONS: The meal stimulated pouch tone and phasic motor activity. These effects were at least partially related to local pouch stimulation by intraluminal contents.

Adolescent↗

PubMed1999

Loss of interstitial cells and a fibromuscular layer on the luminal side of the colonic circular muscle presenting as megacolon in an adult patient.

BACKGROUND: Animal studies have shown that the neuromuscular structures on the luminal side of the colonic circular muscle coordinate circular muscle activity. These structures have been identified by electron microscopy in the normal human colon, but have never been thoroughly studied in patients with acquired intestinal hypoganglionosis. AIMS: To perform histological, immunocytochemical, and electron microscopic examinations of the colon of a patient with acquired intestinal hypoganglionosis presenting as megacolon. PATIENT: A 32 year old man with a one year history of constipation and abdominal distention, a massively dilated ascending and transverse colon, and a normal calibre rectum and descending and sigmoid colon. He had a high titre of circulating serum anti-neuronal nuclear antibodies. METHODS: Histology, immunocytochemistry (for neurofilaments, neurone specific enolase, synaptophysin, glial fibrillar acidic protein, S100 protein, and smooth muscle alpha-actin), and electron microscopic examinations on the resected colon. RESULTS: The number of ganglion cells and nerve trunks was decreased throughout the colon. Disruption of the neural network and a loss of interstitial cells of Cajal were observed on the luminal side of the circular muscle; in their place, the non-dilated colon contained a hypertrophic fibromuscular layer. CONCLUSIONS: Striking architectural alterations occurred at the site regarded as the source of the coordination of colonic circular muscle activity in an adult patient with acquired intestinal hypoganglionosis presenting as megacolon.

Adult↗

PubMed1999

Mistaken diagnosis of eosinophilic colitis.

A 69-year-old male chronic alcohol abuser suffering from diarrhoea and with a number of discrete pruriginous and erythematous lesions of the trunk was referred to our Unit with a diagnosis of idiopathic eosinophilic colitis in order that we might determine corticosteroid treatment. Diagnosis was based on the presence of marked peripheral eosinophilia and massive eosinophilic infiltration at colonic biopsy, and the exclusion of parasitic infection by means of two different microscopic stool examinations of five samples. However, repeated stool examinations of ten samples collected on separate days and evidence of impaired cell-mediated immunity allowed a definite diagnosis of Strongyloides stercoralis autoinfection or hyperinfection. Due to the poor sensitivity of stool examination in the diagnosis of Strongyloides stercoralis infection, a careful search for this parasite should be made in all patients with comparable clinical findings before formulating a diagnosis of idiopathic eosinophilic colitis, because consequent steroid treatment may have a fatal outcome by inducing widespread dissemination of the parasite.

Aged↗

PubMed1998

Plasma somatostatin-like immunoreactivity and somatostatin-28 levels in obese men.

Somatostatin (SS) impairs nutrient absorption. It has been suggested that hyposomatostatinaemia may be involved in the pathogenesis of obesity. However, data on postprandial SS-like immunoreactivity (SLI) levels in obese subjects are controversial and the levels of SS-28, the main molecular form of circulating SLI in healthy subjects, have not been determined. To characterise the fasting and postprandial plasma pattern of SLI and SS-28 in obese men, we studied eight obese men (age 24-32 yr, BMI 33-42 kg/m2), with normal glucose tolerance test and normal gastric emptying of solids, and eight healthy men (age 24-39 yr, BMI 21-24 kg/m2). Blood samples were taken at regular intervals in fasting conditions and for 2 h after a standard solid-liquid meal (2.3 MJ). Plasma SLI and SS-28 were measured by RIA. Our results showed that fasting and postprandial plasma SLI and SS-28 levels were not significantly different in healthy and obese subjects. In conclusion SS-28 is the predominant form of circulating SLI in obese subjects. The normal pattern of fasting and postprandial plasma SLI and SS-28 levels in such subjects suggests that somatostatin does not have a pathogenetic role in obesity.

Adult↗

PubMed1997

Oesophageal manometry in the evaluation of megacolon with onset in adult life.

BACKGROUND: Oesophageal motility is often impaired in patients with megaduodenum and other forms of intestinal pseudo-obstruction in which a visceral myopathy or neuropathy may be present. Idiopathic longstanding megacolon with onset in adult life is still a poorly defined entity, which may also be part of a more widespread motility disorder but in which oesophageal motility has not been yet systematically studied. AIMS: To assess oesophageal motility in patients with longstanding idiopathic megacolon with onset in adult life. PATIENTS: 14 consecutive subjects with idiopathic megacolon whose symptoms began after the age of 10 and a clinical history of 2-22 years. METHODS: Standard barium enema, water perfused oesophageal manometry, and also anorectal manometry. RESULTS: Oesophageal motility was impaired in five patients (36%; 95% confidence intervals 16 to 61%). Normal peristalsis was substituted by low amplitude multiple peaked simultaneous contractions in four subjects and by undetectable contractions in one. In three of them the lower oesophageal sphincter did not relax after swallows; in the same patients anal relaxation after rectal distension was also undetectable. All five patients with impaired oesophageal motility had a colonic dilatation sparing the rectum. Three of them reported constipation and a history of pesudo-obstruction and the other two only abdominal distension. CONCLUSIONS: Oesophageal manometry should be performed in patients with longstanding idiopathic megacolon with onset in adult life, in particular if the rectum is not dilated and even in absence of pseudo-obstruction. This simple test may disclose a more widespread visceral neuropathy or myopathy. Such a diagnosis helps to better understand the cause of the colonic dilatation and may be clinically relevant for treatment of the patients.

Adolescent↗

PubMed1997

Hereditary megaduodenum.

Hereditary megaduodenum is a rare disease with autosomal dominant transmission characterized by visceral myopathy that involves the digestive and urinary tracts, and usually presents as intestinal pseudo-obstruction. Recently, a high rate of spontaneous chromosomal damage was found in blood lymphocytes of patients with hereditary megaduodenum, predictive of an increased cancer risk. Clinical manifestations of the disease vary, ranging from severe pseudo-obstruction to asymptomatic family members; recurrent urinary tract infections are common. Histology reveals vacuolar degeneration and fibrosis of the longitudinal layer of gastrointestinal muscle. This disease should be suspected in patients with an enlarged duodenum but no mechanical obstruction. Treatment is symptomatic and based on diet and control of bacterial overgrowth. Enteral or parenteral nutrition may be needed. Laterolateral duodenojejunostomy and gastrojejunostomy may sometimes be helpful to relieve obstructive symptoms. The risk of cancer in patients with hereditary megaduodenum is still unknown. This paper describes a family with hereditary megaduodenum in which one of the three affected members died of esophageal carcinoma and reviews the literature on the disease with particular attention to reports of cancer.

Adult↗

PubMed1997

Plasma somatostatin levels in patients with chronic idiopathic intestinal pseudo-obstruction.

OBJECTIVES: Somatostatin participates in the control of gut motility. Recently, somatostatin analogs have been proposed as therapeutic agents for chronic intestinal pseudo-obstruction, although the endogenous somatostatin pattern has never been assessed in this syndrome. We aimed to evaluate fasting and postprandial plasma somatostatin levels in patients with chronic idiopathic intestinal pseudo-obstruction (CIIP). METHODS: We studied eight patients with CIIP and 10 healthy volunteers. Blood samples were taken at regular intervals while patients and subjects fasted and during the 3 h after a standard solid/liquid meal (550 kcal) had been eaten. Somatostatin was measured by radioimmunoassay. RESULTS: Fasting somatostatin levels were normal, whereas postprandial peptide responses were markedly impaired or even absent in patients with CIIP. CONCLUSIONS: An impaired postprandial somatostatin response in patients with CIIP seems to be characteristic of this heterogenous disorder. Whether the lack of somatostatin response to a meal identifies patients with severe gut dysmotility for whom treatment with somatostatin analogs would be useful remains to be verified.

Adult↗

PubMed1996

Oesophageal acid clearance in patients with systemic sclerosis: effect of body position.

OBJECTIVE: To test the effect of body position on oesophageal acid clearance time in patients with systemic sclerosis. DESIGN AND METHODS: Fifteen consecutive patients with systemic sclerosis and six healthy subjects underwent oesophageal manometry and an acid clearance test in three body positions (supine, recumbent at 30 degrees and seated at 90 degrees) in randomized order. RESULTS: In healthy subjects the body position did not affect acid clearance time, whereas in patients the oesophagus cleared mainly by gravity. In patients the acid clearance time was significantly longer in the supine than in the seated position (P < 0.05). Nine patients did not have a detectable peristaltic wave in the distal oesophagus. In the other six oesophageal peristalsis was still detectable but contractions had reduced amplitude and often had double and triple peaks; also in this subgroup the acid clearance time recorded in the supine position was prolonged. CONCLUSIONS: In systemic sclerosis gravity plays a major role in oesophageal acid clearance time. The finding of delayed acid clearance in a supine patient may suggest initial oesophageal involvement in the disease.

Adolescent↗

PubMed1995

High spontaneous chromosomal damage in lymphocytes from patients with hereditary megaduodenum.

Chromosomal aberration and micronucleus assays were used to investigate the extent of cytogenetic damage in peripheral blood lymphocytes from four patients in two unrelated families with hereditary megaduodenum. The frequencies of total chromosomal aberrations, which significantly correlated with those of micronuclei, were higher in the patients than in sex- and age-matched controls, with no overlapping between the two groups. The considerable chromosomal fragility in patients with hereditary megaduodenum may be a genotypic marker for preclinical diagnosis predictive of increased cancer risk.

Adult↗

PubMed1995

Tonic responses of canine proximal colon: effects of eating, nutrients, and simulated diarrhea.

Our hypothesis was that the proximal colon relaxes to accommodate flow from the ileum. Therefore, we recorded tonic responses of the canine proximal colon to flow through the ileum and colon stimulated by 1) an 840-kcal meal, 2) nutrients perfused into the ileum and colon, or 3) rapid infusion of saline into the ileum with overflow into the colon. Saline infusion was considered to be a model of diarrhea, and the effects of an antidiarrheal (morphine sulfate) were therefore assessed. Proximal colonic tone was measured with a barostat. Tone increased before and after the arrival of chyme in the ileocolonic region. Perfusion of nutrients into the ileum and colon also significantly increased (P < 0.05) colonic tone compared with equal volumes of saline. Rapid perfusion of the ileocolonic segment with saline increased colonic tone; this increase was significantly greater (P < 0.01) when preceded by morphine. In contrast to our hypothesis, tone of the canine proximal colon increased in response to ileal flow. The increase in colonic tone during the late response to food was at least partly attributable to stimulation by intraluminal contents.

Animal Nutritional Physiological Phenomena↗

PubMed1994

Manometric patterns of rat colonic motor activity and defecation. Effect of selective 5HT1A agonist 8-OH-DPAT.

We investigated in conscious and unrestrained rats, the major patterns of colonic pressure waves, as related to defecation. A manometric low compliance perfusion system, which was set at a very low flow rate (0.03 ml/min), permitted simultaneous recordings of intraluminal pressure in the proximal, transverse, and distal colon. Pressure waves in control rats reflected two types of motor activity: short-duration waves (< 15 sec), that were frequent throughout the colon (about 40-90/hr with aborally decreasing frequency), and propulsive, long-duration, high-amplitude waves (> 15 sec, > 15 mm Hg) that occurred only occasionally (1/hr or less) in the transverse and distal, but not in the proximal colon; these waves appeared to migrate aborally and were associated with defecation. The serotonin 5HT1A agonist 8-OH-DPAT dramatically and dose-dependently increased the frequency of long-duration, high-amplitude waves in the transverse and distal colon, and concurrently promoted defecation; these effects were prevented by the putative 5HT1A antagonist pindolol. We conclude that 5HT1A agonists such as 8-OH-DPAT may promote defecation and occurrence of propulsive waves through the same serotoninergic mechanism.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1994

Ileal distention relaxes the canine colon: a model of megacolon?

BACKGROUND/AIMS: Reflex relaxation is a mechanism whereby the colon can show short-term dilatation in the absence of mechanical obstruction. This study investigated the tonic response of the canine colon to ileal distention and its pharmacological control. METHODS: In four dogs, the tone of the proximal colon was recorded by a barostat during distention of the terminal ileum. RESULTS: Ileal distention inhibited ileal motility and relaxed the colon. Adrenergic blockade by propranolol plus phentolamine, nicotinic blockade by hexamethonium, and the nitric oxide synthase inhibitor N omega-nitro-L-arginine methylester significantly increased resting tone of the colon but did not inhibit relaxation induced by ileal distention. Muscarinic blockade by atropine completely relaxed the colon, and no further decrease in tone was observed after ileal distention. The neurokinin 2 antagonist SR48968 did not alter colonic tone. CONCLUSIONS: The barostat was able to monitor resting tone of the canine colon, which was shown to be under inhibitory control by adrenergic, cholinergic-nicotinic, and nitric oxide-like transmitters. Inhibition of colonic tone by ileal distention was not mediated solely by adrenergic, cholinergic-nicotinic, or nitric oxide mechanisms. Reflex relaxation, possibly predisposing to acute colonic dilatation, may be activated by multiple mechanisms that may differ from those controlling resting tone.

Animals↗

PubMed1994

A selective NK-2 antagonist blocks the increase of canine colonic tone and ileal contractions induced by the NK-2 selective receptor agonist, [beta Ala8] neurokinin A-(4-10).

BACKGROUND: The regulatory roles of tachykinins in intestinal motor function may be clarified by use of novel, stable and selective antagonists of neurokinin receptors. We studied the effects of the non-peptide NK-2 receptor antagonist SR48968 on canine colonic tone under resting conditions and after stimulation by the selective NK-2 receptor agonist [beta Ala8] neurokinin A-(4-10). METHODS: Experiments were performed in three conscious female dogs. Proximal colonic tone was recorded by a barostat and intraluminal pressures were recorded in the terminal ileum. 10, 15 and 20 cm orad to the ileocaecal junction. In separate experiments, and in a random sequence, dogs received an i.v. injection of the NK-2 antagonist SR48968, 10, 100, 1000 micrograms/kg, followed after 30 min by 2 micrograms/kg of the agonist [beta Ala8] neurokinin A-(4-10). Experiments were replicated twice in each dog. RESULTS: The NK-2 agonist increased colonic tone, and SR48968 antagonized these effects in a dose-dependent fashion (Spearman's rank, r = 0.86; P < 0.01); antagonism was complete at the highest dose. SR48968 alone had no effect on colonic tone and ileal motility. When given during phase I or II of the interdigestive motor complex, [beta Ala8] neurokinin A-(4-10) increased ileal contractions: pre-treatment with SR48968 blocked this increase in ileal motility. When given during phase III, [beta Ala8] neurokinin A-(4-10) interrupted the motility front; this effect was not antagonized by SR48968. CONCLUSIONS: SR48968 antagonizes the increase in canine colonic tone and ileal motility induced by activation of NK-2 receptors. However, SR48968 by itself had no effect on the control of colonic tone and ileal motility under unstimulated conditions. SR48968 may be useful for investigating the physiological role of tachykinins on the gastrointestinal tract.

Animals↗