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M Muñoz-Navas

Publications and source records attributed to M Muñoz-Navas.

14 recordsLinked to original sources
PubMed2002

Distribution of the long leptin receptor isoform in brush border, basolateral membrane, and cytoplasm of enterocytes.

BACKGROUND AND AIM: Leptin, a hormone mainly produced by fat cells, acts primarily on the hypothalamus regulating energy expenditure and food intake. Leptin receptors are expressed in several tissues and the possible physiological role of leptin is being extensively investigated, with the result that important peripheral actions of the hormone in the organism are being discovered. Recent studies have demonstrated leptin and leptin receptor expression in gastric epithelial cells. In the present study, we report the presence of the long leptin receptor isoform (OB-Rb) in human, rat, and mouse small intestine, supporting the hypothesis of leptin as a hormone involved in gastrointestinal function. METHODS: The presence of the leptin receptor was determined by immunocytochemical methods using antibodies against the peptide corresponding to the carboxy terminus of the long isoform of the leptin receptor. Human duodenal biopsies from normal individuals undergoing gastrointestinal endoscopy, and intestinal fragments of Wistar rats and Swiss mice were processed for the study. RESULTS: Immunoreactivity for the long leptin receptor isoform was observed in the three studied species. Staining was located throughout the cytoplasm of the enterocytes, of both villi and crypts, and in the basolateral plasma membrane. Immunolabelling for OB-Rb protein was also found in the brush border of human enterocytes of formol and paraformaldehyde fixed samples. CONCLUSION: This report demonstrates the presence of the long leptin receptor isoform in the absorptive cells of rat, mouse, and human small intestine, suggesting that leptin could have a physiological role in the regulation of nutrient absorption.

Animals↗
PubMed1997

Continuous intragastric pH monitoring in the evaluation of ebrotidine, cimetidine and placebo on gastric acidity in healthy volunteers.

This study was conducted to determine the efficacy and tolerance of ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4-thiazolyl) methyl]thio]ethyl]amino]methylene]-4-bromo-benzenesulfonamide, CAS 100981-43.9, FI-3542), a new H2-receptor antagonist, on reducing gastric acidity after a single 800 mg dose, compared with cimetidine 800 mg once daily and placebo by means of a continuous intragastric pH monitoring. A total of 30 healthy volunteers were allocated to receive in a double blind, parallel design the study medication. Clinical observations, physical examinations and visual analogue scales (VAS) were performed during the study to assess the tolerability of the three treatments. Ebrotidine and cimetidine caused a greater and longer-lasting gastric acid inhibition than placebo. With ebrotidine, significantly (p < 0.05) higher median pH values (and interquartile range, IQR) were reached in the post-administration (2.61, IQR 2.02-3.93), postprandial (3.38, IQR 2.82-3.91) and nocturnal (2.83, IQR 1.69-3.77) periods than with placebo: 1.82 (IQR, 1.66-2.09), 2.81 (IQR, 2.02-3.28), and 1.89 (IQR, 1.44-2.13), respectively. Cimetidine showed significant differences compared to placebo in the post-administration (2.36, IQR 1.89-3.46) and nocturnal (2.46, IQR 1.88-4.33) periods. No statistical differences were observed between the active treatments. Ebrotidine caused a significantly higher percentage of time above pH 2.0 in the post-administration and nocturnal periods compared to placebo (p < 0.05), and above pH 3.0 in the post-administration, postprandial and nocturnal periods. No serious adverse effects, or disturbances in the VAS or in the vital signs were reported, and all medications were well tolerated. It is concluded that a single dose of ebrotidine 800 mg is as effective as cimetidine 800 mg in reducing total and nocturnal intragastric acidity. The study also confirms the excellent safety profile of the new drug.

Adult↗
PubMedDate not supplied

[Utility of endoscopy in digestive hemorrhage due to vasculitis].

Vasculitides constitute a heterogeneous group of diseases characterized by inflammation of blood vessels. The skin is mainly affected, although the gastrointestinal tract mucosa can also be involved. The contribution of endoscopy in these cases has not been clearly determined. We report three cases of systemic vasculitis (polyarteritis nodosa, Schonlein-Henoch purpura and Behcet's disease) presenting with acute digestive bleeding. Endoscopy was an effective technique for completing the diagnosis and in establishing an effective nonsurgical therapeutic approach in these potentially lethal cases of gastrointestinal hemorrhage.

Adult↗
PubMedDate not supplied

[Barrett's esophagus].

Barrett's esophagus (BE), a complication of gastroesophageal reflux disease, is the replacement of squamous tissue with specialized intestinal metaplasia. Other noxious factor, as biliary acids, may contribute to the induction of BE. It is a premalignant condition, and adenocarcinoma arises in some cases. An endoscopic surveillance with multiple biopsies is mandatory to detect different grades of dysplasia or intramucosal cancer and allow effective therapy. Since its prevalence is high, current surveillance protocols become expensive and patient's compliance is difficult. The main medical goals are: 1) To stratify individuals without dysplasia as either lower or higher risk, to screen less often those at lower risk. 2) To obtain complete remission or eliminate the risk of cancer and the need for surveillance. Current treatments have not demonstrate complete regression of metaplasia. Recently, new endoscopic approaches to therapy have been developed. Although they remain experimental and larger series are required, initial results are encouraging.

Adenocarcinoma↗