Biomedical subjects

A Missanelli

Publications and source records attributed to A Missanelli.

5 recordsLinked to original sources

PubMed2006

Meal induced rectosigmoid tone modification: a low caloric meal accurately separates functional and organic gastrointestinal disease patients.

BACKGROUND AND AIMS: Diagnosis of irritable bowel syndrome (IBS) is based on arbitrary criteria due to the lack of an accurate diagnostic test. The aim of this study was to evaluate whether rectosigmoid tone modification after a meal represents an accurate diagnostic approach. METHODS: In a secondary care setting, 32 constipation predominant and 24 diarrhoea predominant IBS patients, 10 functional diarrhoea and 10 functional constipation patients, 29 organic gastrointestinal disease patients, and 10 healthy volunteers underwent a rectal barostat test to measure fasting and postprandial rectosigmoid tone. Rectosigmoid response was assessed following three meals containing different amounts of calories: 200 kcal, 400 kcal and 1000 kcal. RESULTS: After 200 kcal, healthy volunteers and patients with organic diseases showed a reduction in rectosigmoid volume of at least 28% of fasting volume, indicating a meal induced increase in muscle tone. In contrast, patients with diarrhoea predominant IBS showed dilation of the rectosigmoid colon, indicative of reduced tone, and patients with constipation predominant IBS showed a mild volume reduction or no modification. Functional diarrhoea and constipation patients showed rectosigmoid tone modification resembling that of the corresponding IBS subtype. A 400 kcal meal normalised rectosigmoid tone in more than half of the constipation predominant IBS patients but none of the diarrhoea predominant IBS patients. In contrast, a 1000 kcal meal normalised tone response in all IBS patients. Sensitivity of the test was 100%, specificity 93%, positive predictive value 96%, and negative predictive value 100%. CONCLUSION: A postprandial reduction in rectosigmoid tone of at least 28% of fasting value after a low caloric meal accurately separates organic and functional gastrointestinal disease patients. This parameter may therefore be used in the positive diagnosis of IBS.

Adult↗

PubMed2005

Absorbable vs. non-absorbable antibiotics in the treatment of small intestine bacterial overgrowth in patients with blind-loop syndrome.

BACKGROUND: Small intestine bacterial overgrowth is associated with the presence of predisposing conditions, acting through different mechanisms. Therefore, the failure to define a standardized therapy may be due to a methodological bias: to treat a condition characterized by different pathophysiological mechanisms with the same pharmacological approach. Non-absorbable antibiotics could have a lower efficacy than absorbable drugs in patients with blind loops which exclude a portion of the intestine from the transit. AIM: To evaluate the efficacy of absorbable vs. non-absorbable antibiotics in this subgroup of patients. METHODS: A group of small intestine bacterial overgrowth patients with total gastrectomy or gastrojejunostomy and blind loop underwent a therapeutic trial comparing rifaximin to metronidazole. Seven patients underwent a course of rifaximin followed by a course of metronidazole on recurrence of symptoms. To compare the effect of the drugs, another two groups of patients underwent two consecutive courses of rifaximin or metronidazole. Hydrogen breath test after glucose administration and symptom severity measurement were performed. RESULTS: Both drugs reduced breath H(2) excretion but a much better improvement was achieved after metronidazole. Symptom improvement was higher after metronidazole. CONCLUSION: Metronidazole is more effective than rifaximin for the treatment of small intestine bacterial overgrowth associated with the presence of a blind loop.

Anti-Bacterial Agents↗

PubMed2004

Probiotics and functional abdominal bloating.

Functional abdominal bloating is a condition dominated by a feeling of abdominal fullness or bloating and without sufficient criteria for another functional gastrointestinal disorder. The currently used therapeutic approaches aim to reduce the volume of intestinal gas, thus increasing intestinal gas elimination or reducing its production. Some promising results have been obtained by the use of prokinetics, such as tegaserod and Prostigmine, and by the use of nonabsorbable antibiotics, such as rifaximin. Another therapeutic approach is represented by the administration of probiotics to modify the composition of colonic flora and thus the production of intestinal gas. The authors recently studied the effect of LGG, which proved to be more effective than placebo in reducing the severity of symptoms.

Abdomen↗

PubMed1999

Biochemical and electrophysiological studies on (S)-(+)-2-(3'-carboxybicyclo(1.1.1)pentyl)-glycine (CBPG), a novel mGlu5 receptor agonist endowed with mGlu1 receptor antagonist activity.

The pharmacological profile of (S)-(+)-2-(3'-carboxybicyclo[1.1.1]pentyl)-glycine (CBPG) and of other group 1 metabotropic glutamate (mGlu) receptor agents were studied in BHK cells transfected with mGlu receptor subtypes or in native receptors in brain slices by measuring second messenger responses. The mGlu receptor-mediated changes in the electrophysiological properties of CA1 pyramidal cells of the hippocampus were also evaluated. In mGlu5a receptor transfected cells, CBPG behaved as a partial agonist, while in mGlu1alpha receptor transfected cells, it behaved as a glutamate antagonist. No effect was found on cAMP formation in cells transfected with mGlu2 receptors or mGlu4 receptors. In brain slices, CBPG neither affected phospholipase D-coupled glutamate receptors nor did it modify the responses to ionotropic receptor stimulation (at concentrations up to 1 mM). When tested in CA1 pyramidal cells of the hippocampus, CBPG (50-100 microM) caused depolarization, increased cell input resistance, and decreased action potential frequency adaptation and afterhyperpolarization. DHPG (3-100 microM), an agonist of both mGlu1 and mGlu5 receptors, and CHPG (1000 microM), a low affinity mGlu5 agonist, produced qualitatively similar effects. The actions of CBPG or CHPG were not modified by AIDA (300 microM), a selective mGlu1 receptor antagonist. Our results suggest that CBPG could be a useful tool for discriminating between mGlu1 receptor and mGlu5 receptor effects and that mGlu5 receptors are the receptors which are mainly responsible for the direct excitatory effects of mGlu receptor agonists on CA1 pyramidal cells.

Animals↗

PubMedDate not supplied

Treatment of small intestine bacterial overgrowth.

Removal of the predisposing condition, appropriate nutritional support to reintegrate both caloric and vitamin requirements and suppression of the contaminating bacterial flora represent the main of goals of the treatment of small intestine bacterial overgrowth. Generally, the polymicrobic nature of contaminating flora requires the administration of wide-spectrum antibiotics, but as yet we don't know which is the best pharmacological approach, in terms of drug, dosage and duration of therapy. There is no conclusive information regarding the most effective therapy that should be used. This paper reviews the efficacy of the different therapeutic approaches used.

Anti-Bacterial Agents↗