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Biomedical subjects

M Camilleri

Publications and source records attributed to M Camilleri.

At least 163 records · Page 9Linked to original sources
PubMed1997

Rapid gastric emptying in patients with functional diarrhea.

OBJECTIVE: To analyze our experience in patients with chronic diarrhea by using a noninvasive transit study that measures gastric emptying as well as small bowel and colonic transit. MATERIAL AND METHODS: Results from 94 consecutive transit tests, for which diarrhea was the main indication, were reviewed and correlated with the final classification of patients as having an organic or nonorganic disorder. RESULTS: Sixty patients were considered to have a nonorganic cause of diarrhea, of whom 15 had previously undergone cholecystectomy. The other 34 patients were considered to have diarrhea on the basis of an organic diagnosis. Gastric emptying was more often rapid in patients with a nonorganic cause (P < 0.05), but not if cholecystectomy had been performed previously. Small bowel transit was fast more often in patients with organic diarrhea than in those with no organic cause of the diarrhea (P < 0.05); colonic transits showed no significant differences among groups. CONCLUSION: The findings implicate a motor abnormality of the upper gut, rapid gastric emptying, as a pathophysiologic mechanism of functional bowel disorders with diarrhea. The results imply that additional prospective observations should be worth-while.

Adult↗
PubMed1997

A pilot study of motility and tone of the left colon in patients with diarrhea due to functional disorders and dysautonomia.

OBJECTIVE: Our aim was to identify qualitative or quantitative colonic motor patterns induced postprandially in a pilot study of patients with diarrhea due to functional disease or dysautonomia to identify objective endpoints for future studies. METHODS: In patients with functional diarrhea (n = 5) or dysautonomia (n = 4) in whom GI transit was documented by scintigraphy, we studied colonic motility by combined manometry and barostat measurements for 1 h fasting and 2 h postprandially (1000-kcal meal). Data were compared with those of healthy control subjects. RESULTS: There were no differences in compliance, overall phasic motility of the left colon, fasting tone, or maximal change in postprandial tone in the diarrhea group as compared with the control group. The diarrhea group showed more high amplitude propagated contractions 4.4 +/- 3.6 (SD)/2 h, p < 0.05) compared with the control group (0.7 +/- 1.4/2 h); the mean postprandial tonic response (12 +/- 14%, p < 0.05) and its duration were reduced in the diarrhea group compared with the control group (27 +/- 17%). Two dysautonomic patients showed a paradoxical relaxation of the colon postprandially. CONCLUSION: Reduced duration of increased colonic tone postprandially and increased number of high amplitude propagated contractions seem to be useful objective endpoints for future studies.

Adult↗
PubMed1997

SDZ HTF 919 stimulates canine colonic motility and transit in vivo.

Effects of the nonbenzamide 5-hydroxytryptamine4 agonist SDZ HTF 919 on gastrointestinal motility are unclear. Our aim was to assess the in vivo effects on gastrointestinal and colonic transit of radiolabeled residue and on colonic phasic contractility. In six female dogs, transit was measured over a period of 2 days by radioscintigraphy and colonic motility was measured by pneumohydraulic perfusion manometry of the proximal and distal colon. SDZ HTF 919 was administered initially by bolus i.v. infusion, followed by s.c. injection 8 and 16 hr later. Doses tested were 0.03, 0.1 and 0.3 mg/kg, and isotonic saline and vehicle served as controls in each dog. Stomach and small bowel transit was not significantly altered by SDZ HTF 919. Overall, i.v. SDZ HTF 919 accelerated colonic transit during the first 1 hr, compared with controls. These effects were significant even with the lowest dose of SDZ HTF 919. Responses to higher infusion doses were more variable. SDZ HTF 919 did not cause significant changes in quantitative pressure indices, such as amplitude or motor index, in the small bowel or colon. Prolonged postprandial colonic contractions, each lasting >30 sec, were noted after each i.v. agent and were significantly more frequent with the 0.03 mg/kg dose than with control (vehicle) treatment. Thus, SDZ HTF 919 accelerates canine colonic transit in vivo during the first 1 hr after i.v. administration. SDZ HTF 919 appears to be a promising agent for stimulation of mammalian colonic transit.

Animals↗
PubMed1997

Colonic motility and tone after spinal cord and cauda equina injury.

AIM: To characterize colonic motility and tone in patients with spinal cord and cauda equina injury. METHODS: Barostat-controlled measurements of tone and manometric measurements of phasic contractions in the left colon in two patients with spinal cord injury. ANALYSIS: Computer based analysis of tone and phasic activity; comparison with data from 11 healthy subjects. RESULTS: Both patients showed normal fasting tone and decreased postprandial tone in the colon; one had markedly decreased phasic contractility in the descending colon, but both had normal sigmoid colon motility. CONCLUSIONS: Impaired postprandial tone and phasic motor function of the descending colon after spinal cord injury with normal sigmoid motility suggests regional differences in the effect of denervation. The effect of the level of injury to the neural axis on colonic motor and sensory function requires further elucidation.

Adult↗
PubMed1997

Simplifying the evaluation of postprandial antral motor function in patients with suspected gastroparesis.

OBJECTIVES: Antral hypomotility is associated with symptoms of gastric stasis[fnc,1. AIMS: To quantitate antral motor function in patients with suspected gastroparesis due to idiopathic or secondary hypomotility; and to determine whether there are simpler indices to assess antral motility. METHODS: Standard eight-lumen antroduodenal manometry was performed in 67 patients for 3-h fasting and 2-h postprandial measurements. Antral motility 1 cm proximal to the pylorus was quantitated for a 2-h fed period as an index: MI = ln[(number contractions x (amplitudes) + 1]. Fifteen healthy volunteers served as controls. RESULTS: Forty-one patients had hypomotility and 26 normal antral motility, defined by a MI > or = 13.67. Patients with antral hypomotility due to a neuropathic (n = 17) or myopathic (n = 3) disorder showed a significantly lower MI (11.6 +/- 0.3 [SEM]; 95% confidence interval 11-12.1) compared with patients with idiopathic hypomotility (n = 21, MI = 12.5 +/- 0.2). There were fewer antral contractions postprandially in patients with secondary hypomotility than in idiopathic hypomotility (66 +/- 6 per 2 h vs 90 +/- 10; p < 0.05), and both were lower than in healthy controls (224 +/- 15). Mean amplitudes of antral contractions were similar for the neuropathic, idiopathic and control groups, but lower in myopathic (33 +/- 6 mm Hg) compared with neuropathic disorders (48 +/- 4 mm Hg; fifth percentile 30.6 mm Hg). CONCLUSIONS: An antral MI < 12.1 should lead to a search for an underlying neuropathic or myopathic process; an average of less than 1 contraction per minute postprandially is a simple estimate of significant hypomotility. Antral contractions with a mean amplitude < 30 mm Hg suggest a myopathic disorder.

Adult↗
PubMed1997

Pharmacological modulation of rectal tone alters perception of distention in humans.

OBJECTIVE: Drugs can alter perception of balloon distention of the GI tract. It has been proposed that the mechanism by which this occurs is through effects on visceral afferent pathways. Our hypothesis was that modulation of rectal tone will also influence the perception of rectal balloon distention. METHODS: Fasting and postprandial rectal tone, compliance, and perception of rectal distention were measured in 25 healthy subjects, using a five-armed, parallel, single-blinded study design. Each subject received either glucagon, nitroglycerin, clonidine, yohimbine, or saline. RESULTS: Rectal tone, but not compliance, influenced perception as measured by balloon distention of the rectum (r = 0.6, p = 0.002). Glucagon, nitroglycerin, and clonidine reduced and yohimbine increased fasting tone compared with saline. Compliance and postprandial tone were similar in all groups. Yohimbine increased rectal perception of distention. CONCLUSIONS: Tone is one of the factors that influences the sensory perception of balloon distention in the human rectum. Alpha2-adrenergic agents, a nitric oxide donor, and glucagon altered fasting rectal tone, but postprandial tone was similar after administration of each agent.

Adult↗
PubMed1997

Colonic transit scintigraphy labeled activated charcoal compared with ion exchange pellets.

UNLABELLED: Scintigraphic measurement of colonic transit is currently performed by delivering 111In ion exchange resin pellets to the colon in a methacrylate-coated capsule. However, use of this method is constrained by the need for an investigational drug permit. We have demonstrated previously optimal adsorption in vitro of commonly used radioisotopes (e.g., 99mTc or 111In) to activated charcoal in milieus that mimicked gastric and small intestinal content. The aim of this study was to compare the transit profiles of radioactive activated charcoal and resin pellets delivered to the colon in the same methacrylate-coated capsule. METHODS: In 10 healthy volunteers, we compared the colonic transit profiles over 32 hr of simultaneously administered resin pellets labeled with 111In and activated charcoal mixed with 99mTc-diethylenetriaminepentaacetic acid. Transit was summarized as the geometric center (weighted average of counts) in the colon at each scanning period. RESULTS: Colonic transit profiles were virtually identical with the two markers, with less than 0.1 geometric center unit differences in the transit profiles over the 32-hr periods. CONCLUSION: Activated charcoal is a suitable alternative to resin pellets when delivered in a methacrylate-coated, delayed-release capsule to the colon for measurement of transit by scintigraphy.

Adult↗
PubMed1997

Octreotide inhibition of flushing and colonic motor dysfunction in carcinoid syndrome.

OBJECTIVES: Previous studies showed increased plasma motilin and substance P concentrations and accelerated motor function in the small bowel and colon in patients with carcinoid diarrhea. Octreotide is beneficial in patients with carcinoid syndrome. Our hypothesis was that octreotide inhibits accelerated motility and gut neuropeptides in carcinoid syndrome. METHODS: In 12 patients with metastatic carcinoid syndrome, we investigated the effect of octreotide 50 microg s.c. t.i.d (n = 6) or placebo (n = 6) on postprandial symptoms, GI transit, colonic motility, and circulating levels of selected circulating peptides and amines. RESULTS: Octreotide reduced postprandial flushing (p = 0.03) but not pain. Octreotide significantly retarded overall colonic transit and proximal colonic emptying (p < 0.05); it tended to prolong small bowel transit time (p = 0.13) and to reduce postprandial colonic tone (p = 0.08) compared with placebo. Octreotide also reduced circulating levels of peptide YY, neurotensin, vasoactive intestinal polypeptide, and substance P but had no effect on plasma motilin, neuropeptide Y, calcitonin gene-related peptide, or histamine after meal ingestion. CONCLUSION: Octreotide ameliorates gut motor dysfunctions that characterize carcinoid diarrhea; the potential role of specific antagonism of serotonin, substance P, and vasoactive intestinal polypeptide alone or in combination with agents that inhibit their release in carcinoid diarrhea deserves further study.

Aged↗
PubMed1996

Antral axial forces postprandially and after erythromycin in organic and functional dysmotilities.

Our aims were to measure antral axial forces in patients with suspected upper gut dysmotilities and to compare the number of antral contractions detected by an axial force catheter and by manometric sensors in the distal antrum and pylorus. Fifteen patients (2 men, 13 women; mean age 42 years) underwent studies for 3 hr fasting, 2 hr postprandially, and up to 60 min after intravenous erythromycin (3mg/kg). Seven patients had gastroparesis or chronic intestinal pseudoobstruction, five functional disease, and three subacute obstruction. Postprandially, the number of peaks detected by the two methods was not significantly different; however, after erythromycin, the axial catheter detected more contractions (P = 0.02). Erythromycin significantly increased the number of postprandial axial forces (from 1.2 +/- 0.3/min to 2.5 +/- 0.3/min, P < or = 0.01) in the whole group and in the organic dysmotility group (P = 0.01). Erythromycin significantly increases the number of axial forces in functional and organic upper gut dysmotilities, but the axial force catheter is not advantageous over manometry for postprandial measurements of antral motility.

Adult↗
PubMed1996

Gastrointestinal problems in diabetes.

Gastrointestinal symptoms are often encountered in patients with diabetes mellitus. Symptoms may arise in any region of the alimentary tract; common symptoms are heartburn, nausea, vomiting, diarrhea, constipation, fecal incontinence, and abdominal pain. This article reviews practical approaches to the identification of the pathophysiologic mechanisms involved in diabetic enteropathies and their complications and briefly outlines strategies to treat these symptoms. Particular emphasis is placed on applied physiologic tests and the choice of pharmacotherapy (e.g., cisapride, erythromycin, or octeotide). The current role of pancreatic transplantations also is briefly reviewed.

Cholelithiasis↗
PubMed1996

Therapeutic strategies for motility disorders. Medications, nutrition, biofeedback, and hypnotherapy.

Gastrointestinal motility is regulated by a complex balance of inhibitory and excitatory neuronal, humoral, and mechanical factors. The goal in the management of motility disorders is to maintain adequate nutrition while decreasing symptoms. This can be accomplished by medications and support of nutrition and biofeedback; the application of these therapeutic strategies to patients with gut motility disorders is reviewed.

Biofeedback, Psychology↗
PubMed1996

Gastrointestinal sensation. Mechanisms and relation to functional gastrointestinal disorders.

This article reviews the basic anatomy and physiology of visceral afferent function and its application to a clearer understanding of visceral pain and symptoms in patients with functional gastrointestinal disorders. Recent investigations have focused on the potential role of visceral tone, different afferent (A delta and C) fibers, dorsal column neurons, and supraspinal modulation in the elicitation of visceral perception of noxious and nonnoxious stimuli arising in the gut. Greater understanding of these pathomechansims and their pharmacologic manipulation offers an opportunity for future therapeutic strategies for these disorders.

Afferent Pathways↗
PubMed1996

Relation between fat malabsorption and transit abnormalities in human carcinoid diarrhea.

BACKGROUND & AIMS: Fat and complex carbohydrates in the distal bowel activate "brakes" inhibiting upper gut motility. The hypothesis of this study was that rapid transit carcinoid diarrhea in association with steatorrhea results in impairment of gastric emptying. METHODS: Fifteen patients with carcinoid diarrhea without prior gastrointestinal resection or whose small bowel resection was limited to < 100 cm of ileum were studied. Gastrointestinal transit was measured scintigraphically with a standardized meal. Percentage of ingested fat excretion was calculated. RESULTS: Mean length of small bowel resected was 33 cm, and mean 24-hour urine 5-hydroxyindoleacetic acid was 120 mg. Fourteen patients had increased daily stool weights, and 10 had increased stool fat excretion (mean, 13%). Transit was accelerated in the small bowel in 14 and in the colon in all patients. The lag time for gastric emptying was prolonged in 2 patients who had no previous resection. Gastric emptying rate was accelerated in 5, normal in 7, and delayed in 3 patients. CONCLUSIONS: Ileal and colonic brakes do not seem to delay gastric emptying in patients with carcinoid diarrhea associated with rapid transit and mild to moderate steatorrhea.

Aged↗
PubMed1996

Hyperventilation alters colonic motor and sensory function: effects and mechanisms in humans.

UNLABELLED: BACKGROUND & AIMS. Hyperventilation-induced hypocapnia affects hemodynamic function and enhances colonic motility. The aims of this study were to determine the effects of hypocapnic hyperventilation on colonic motility and sensation in health and to explore the putative neurohumoral mechanisms. METHODS: In experiment 1, colonic tone, sensation, plasma levels of cortisol, beta-endorphin, selected gut neuropeptides, norepinephrine, epinephrine, and splanchnic blood volume were measured during two sequences of hypocapnic hyperventilation. In experiment 2, colonic tone and sensation were assessed during eucapnic hyperventilation and abdominal compression. RESULTS: Hypocapnic hyperventilation, but not eucapnic hyperventilation or abdominal compression, significantly increased colonic tone and sensitivity to balloon distention (P = 0.017) without altering humoral mediators or splanchnic blood volume. Plasma norepinephrine level increased (P = 0.017) and splanchnic blood volume decreased (P = 0.028) during 5 minutes after hyperventilation, consistent with homeostatic responses. CONCLUSIONS: Increased colonic tone and sensation during hypocapnic hyperventilation are not caused by colonic compression. These effects of hyperventilation are not mediated humorally but may result from direct metabolic effects of hypocapnia on colonic muscle or from changes in central autonomic control of colonic smooth muscle.

Adult↗
PubMed1996

Gastrointestinal dysfunction in neurologic disease.

Gastrointestinal motor dysfunctions result when extrinsic autonomic nerves are diseased and are unable to modulate the motor functions of the digestive tract, which depend on the enteric nervous system and the automaticity of the smooth muscles. Gut motor dysfunction may result from disorders at all anatomic levels of the extrinsic neural control and degenerations of gut smooth muscle. It illustrates the important modulation of gut motor function by the nervous system. Although much emphasis has been placed on dysphagia and constipation in neurologic disorders, more recent studies have highlighted incontinence, vomiting, and abdominal distention in the symptomatology of such patients. Strategies that evaluate the motor functions of the digestive tract and the extrinsic neural control are available; they aid in selection of rational therapies for these patients, which include physical therapy and biofeedback training (for dysphagia or incontinence), prokinetic agents (for neuropathic forms of gastroparesis, chronic intestinal dysmotility, or slow transit colonic disorders), and nutritional support using the enteral or parenteral route. Electrical or magnetic stimulation of lumbosacral roots provides a novel method to alleviate constipation in paraplegics.

Afferent Pathways↗
PubMed1996

Symptomatic improvement with one-year cisapride treatment in neuropathic chronic intestinal dysmotility.

AIM: To assess the efficacy of a prokinetic agent in the long-term treatment of chronic intestinal dysmotility and the influence of extrinsic denervation. METHODS: We assessed symptoms, compliance and untoward effects in an open, 1-year trial of cisapride, 20 mg t.d.s., in 37 patients with neuropathic forms of chronic intestinal dysmotility. Patients' autonomic function had previously been characterized; effects of cisapride at 12 weeks in a placebo-controlled trial were previously reported. RESULTS: Seventeen patients had idiopathic dysmotility, 11 had diabetes mellitus with autonomic dysfunction, five had had previous gastric surgery and four had neurological syndromes. Median medication compliance was 98.9% for the study period completed by each individual. Median duration of follow-up was 9.5 months; 20 patients completed 1 year of treatment, and 27 of 37 at least 6 months of treatment; seven dropped out because of lack of benefit. Mean total symptom score was significantly reduced at the last observation relative to the entry into the trial; this was particularly the case in those patients without abdominal vagal dysfunction. One patient withdrew because of aggravation of abdominal pain. CONCLUSIONS: During an open, long-term trial, cisapride, 20 mg t.d.s., provided continued symptomatic relief to patients with chronic intestinal dysmotility, particularly those without vagal neuropathy.

Adult↗
PubMed1996

Autonomic control of colonic tone and the cold pressore test.

BACKGROUND: Cardiovascular responses to cold stimulation are well characterised. It is unclear, however, whether cold pain stimulates responses in colonic tone in the transverse and sigmoid regions. AIMS: To assess the effects of cold stimulation on tone nd motility in the transverse and sigmoid colon and on cardiovascular autonomic activity. METHODS: Phasic and tonic motility of the transverse and sigmoid colon, pulse rate, and beat to beat pulse variability (which are measures of centrally mediated changes in autonomic function) were measured before, during, and after a standard cold pressor test in 22 healthy volunteers. RESULTS: Cold pain induced a significant increase in colonic tone but not phasic contractility in the transverse and sigmoid regions. Simultaneously, cold pain increased pulse interval variability. CONCLUSION: The findings are consistent with the hypotheses that cold pain produces coactivation of both the sympathetic and parasympathetic limbs of the autonomic nervous system and that cold induced changes in colonic tone are temporally associated with alterations in central autonomic nervous activity.

Adult↗