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Biomedical subjects

F Pellicer

Publications and source records attributed to F Pellicer.

At least 19 recordsLinked to original sources
PubMed2004

Usefulness of capsule endoscopy in patients with suspected small bowel disease.

AIM: To study the usefulness and safety of capsule endoscopy as a diagnostic tool in various small bowel disorders. DESIGN: A retrospective analysis of a series of cases. MATERIAL AND METHODS: Between August 2001 and August 2002, 92 capsule endoscopy procedures were performed in 88 patients (53M/39F, age: 43.87 +/- 16.78). Indications included: chronic diarrhea (n=33); unknown abdominal pain (n=29); occult gastrointestinal bleeding or iron-deficiency anemia (n=13); abdominal discomfort in NSAID takers (n=7); staging of gastrointestinal tumors (n=4), and asymptomatic controls (n=2). Previously performed gastroscopy, colonoscopy, and small-bowel follow-through were not conclusive in all patients. RESULTS: Most frequently relevant findings included: jejuno-ileal aphtas and ulcerations (29 patients), vascular malformations (13 patients), and intestinal neoplasm (6 patients). The groups with a higher rate of findings related to this indication were occult gastrointestinal bleeding (76.92%) and chronic diarrhea (67.85%), with the lowest rate in the abdominal pain group (34.48%). Therapeutic strategy was directly changed in 36 of 88 patients (40.90%) because of capsule-endoscopic findings. The only observed complication was the failed excretion of one of the capsules because of an unknown ulcerated intestinal stricture. CONCLUSIONS: Capsule endoscopy is a safe procedure which can study the entire small bowel, meaning a valuable tool for the management of patients with suggestive signs and symptoms of intestinal disorders.

Adolescent↗
PubMed2003

Capsule endoscopy in patients with suspected Crohn's disease and negative endoscopy.

BACKGROUND AND STUDY AIMS: The aim of the present study was to assess the value of capsule endoscopy in the diagnostic work-up of patients in whom there is a clinical suspicion of small bowel Crohn's disease that cannot be confirmed using traditional techniques. PATIENTS AND METHODS: A total of 21 patients (14 men, seven women; mean age 43 +/- 8 years) with a clinical and biochemical suspicion of Crohn's disease were included in the study. Conventional imaging work-up, including upper and lower endoscopy, as well as a small-bowel follow-through, was carried out in all of the patients. RESULTS: Pathological findings were not observed in 12 of the 21 patients (57 %). In the other nine patients (43 %), lesions supporting the diagnosis of Crohn's disease were seen. The most frequent findings were located in the distal ileum and included aphthae, lineal and serpiginous ulcers, and fissures. Four patients had lesions in the jejunum. One patient showed erosions in the distal duodenum, jejunum, and ileum. No adverse effects of the technique were observed in any of the patients. CONCLUSIONS: Capsule endoscopy is a valuable diagnostic tool in patients with suspected Crohn's disease that has not been confirmed using standard imaging techniques.

Adult↗
PubMed2001

Lesion and electrical stimulation of the ventral tegmental area modify persistent nociceptive behavior in the rat.

The ventral tegmental area (VTA) has been traditionally related with the control of motor responses. However, some studies show that this area is also involved in the processing of nociceptive information. It has been reported that this nucleus participates in the dissociative analgesia phenomenon. In the few works where electrical stimulation and lesion of the VTA have been performed, evaluated with persistent or chronic pain related behaviors, contradictory results have been obtained. Thus, a more detailed analysis of the role of the VTA in persistent pain is needed. Two series of experiments were performed: lesions of this nucleus were done with radiofrequency, (bilaterally at two points per side using a temperature range from 50 to 80 degrees C), and the VTA was electrically stimulated (10 min daily over 5 days, 2 ms rectangular pulses at 100 Hz during 1 s every 5 s) using two different schemes:10 min before the induction of the nociceptive stimulus and 90 min after the induction of the nociceptive stimulus. The latter allowed us to distinguish if the VTA electrical stimulation had a distinctive antinociceptive effect when applied before or after the induction of the nociceptive stimulus on a persistent pain related behavioral response in the rat, the self injury behavior (SIB). Our results showed that VTA lesions enhanced the occurrence of SIB; while activation of this same nucleus by electrical stimulation after the nociceptive stimulus, but not before, facilitates the analgesic process, expressed as a 1 day delay in SIB onset. These results indicate that the VTA is a brain structure that plays a key role in the processing and modulation of persistent pain information. Data are discussed in terms of the relationship of the VTA with the affective component of pain.

Analgesia↗
PubMed2001

Effect of red peppers (Capsicum frutescens) intake during gestation on thermonociceptive response of rat offspring.

Oral administration of aqueous red pepper (Capsicum frutescens, Cf) solution and low capsaicin (8-methyl-N-vanillyl-6-nonenamide) doses during gestation produces an increase in the latency of the thermonociceptive escape response of rat offspring. The present work shows that different amounts of Cf (10%, 25% and 50%) incorporated to normal food of gestating rats modify in a dose-dependent manner the flexion reflex latency (R), as well as the latency of appearance of antialgesic behaviours expressed as paw lick (P) and escape response (E) using the hot plate test (53 degrees C+/-0.5 degrees C). The latency of the same parameters was tested in the same subjects 55 days later to determine the persistence of this effect. Results show an increase in latency of the three parameters R, P and E in all experimental groups with respect to controls. Animals (Cf, 25% group) tested 55 days after the first test exhibited latencies similar to controls, which suggests that the process is reversible.

Animals↗
PubMed2001

Toluene increases acute thermonociception in mice.

Toluene is an abused solvent widely used in several commercial products. Recent evidence indicates that this solvent is a non-competitive inhibitor of NMDA receptors. Since NMDA receptors have been implicated in pain, this paper describes studies of the effects of increasing concentrations of inhaled toluene on nociception. Swiss Webster mice were exposed to toluene (500-8000 ppm) in static exposure chambers for 30 min. After completing the exposure period, animals were tested for nociception using the hot plate test. Toluene dose-dependently increased nociception as reflected by shorter latencies for the reflex, paw-lick and escape responses in toluene-treated mice with respect to their controls (animals exposed to air). In order to determine the possible role of opioids in this response, morphine (1-10 mg/kg) was injected before toluene inhalation. Toluene was not able to block morphine-induced antinocieption, however, it produced a shift of the morphine dose-response curve to lower effects, suggesting a physiological antagonism. No potentiation was seen when toluene was administered in combination with naloxone. Present results suggest that toluene increases nociception via neurotransmitter systems others than the glutamatergic.

Administration, Inhalation↗
PubMed2000

Stimulation of the medical preoptic area facilitates sexual behavior but does not reverse sexual satiation.

The aim of the present study was to establish whether electrical and/or drug stimulation of the medial preoptic area/anterior hypothalamus (mPOA/AH) surmounts the sexual behavior inhibition that results from copulation to exhaustion. Thus, intermittent electrical stimulation of the mPOA/AH (alone or combined with the systemic injection of yohimbine or apomorphine, at doses that were subthreshold for reversing sexual exhaustion) or intrapreoptic treatments to block GABAergic transmission were applied to sexually satiated rats. The results suggest that the mPOA/AH is not responsible for male sexual behavior inhibition or for the pharmacologically induced sexual behavior expression in satiated rats. Data are discussed in terms of the roles ascribed to the mPOA/AH, both in the control of sexual behavior expression and in the regulation of the postejaculatory interval.

Animals↗
PubMed1999

Electric stimulation of the cingulum bundle precipitates onset of autotomy induced by inflammation in rat.

The purpose of this work was to test if electric stimulation of the cingulum bundle in animals subjected to a hindpaw inflammatory process precipitates the onset and enhances autotomy behaviour. Wistar rats were implanted with bipolar parallel electrodes in the boundary of the cingulum bundle. The inflammatory process was induced in all subjects by injection of carrageenan. The groups were: A, sham; B, implanted and stimulated 10 min daily for 7 days; C, implanted and stimulated 2 h daily, for 7 days. Both groups were injected with CAR 2 days after ending the stimulation period; and D, implanted and stimulated 10 min daily for 5 days, the first stimulation being simultaneous to CAR injection. Results show that 100% of the subjects in stimulated groups presented autotomy as compared with 66% in the sham group. A significant shortening of the onset and increased rates in autotomy were observed in experimental groups (B, C and D) as compared to the sham group. We did not find differences between groups B and C, but there was an increment of autotomy in group D when compared with both B and C groups. We conclude that it is possible to facilitate the onset and to increase the intensity of the autotomy triggered by the inflammatory process with cingulum bundle electrical stimulation. The results also suggest that a fundamental condition to the development of the autotomy in this model is the presence of the noxious inflammatory process. Copyright 1999 European Federation of Chapters of the International Association for the Study of Pain.

Journal Article↗
PubMed1998

Self-mutilation in the Lesch-Nyhan syndrome: a corporal consciousness problem?--a new hypothesis.

The Lesch-Nyhan syndrome (LNS) has been extensively studied from the genetic and biochemical point of view. The main characteristic of the syndrome is the self-mutilation feature, which has been poorly studied and understood. We propose a new hypothesis about the self-mutilation physiopathology, which is related to the supersensitivity of the dopaminergic D1 receptors in the neuromatrix found in the cingulum cortex region. The LNS shows an increase of uric acid levels as a result of the deficiency of hypoxanthine phosphoribosyltransferase enzyme. This increase could induce damage to dopaminergic neurons. As a consequence, a decrease in dopamine synthesis during gestation and the early postnatal period could occur, producing a functional dopaminergic denervation of the D1 receptors, located on the prefrontal cortex, specifically in the cingulum bundle projections. This phenomenon could induce a codification disturbance in the 'genetic body' of the neuromatrix, that could be expressed functionally as anosognosia, giving rise to self-mutilation. We suggest that this self-mutilation is a pain consciousness problem.

Brain↗
PubMed1996

Capsaicin or feeding with red peppers during gestation changes the thermonociceptive response of rat offspring.

Capsaicin is responsible for the pungent sensation produced by red peppers on the body's mucous membranes. This substance is found naturally in the gender Capsicum, widely used in the diet of different cultures in America, Asia, and Africa. In this paper we used the hot plate model (53 +/- 0.5 degrees C) to study the effect of acute thermonociceptive stimulus on escape response latency in the offspring of rats that were treated during gestation, either with an aqueous red pepper solution (Capsicum frutescens, approximately 2.75 mg of capsaicin in 1 ml/day, by gavage during the second week), or with capsaicin (0.5 mg/day SC, during the second week). These groups were compared with their respective controls. We found that the difference between the manipulated control group and the one given the aqueous red pepper solution was 41.33%, and between the vehicle control and the one treated with capsaicin was 30.59%. These increments on the escape response latency were statistically significant. Our results show that both treatments, the aqueous red pepper extract and low doses of capsaicin on pregnant rats. produce an increment on escape response latency due to a thermonociceptive stimulus.

Animals↗
PubMed1996

[Self-expanding esophageal metal stents in the palliative treatment of esophageal cancer].

We report our experience of two years (February 1993-February 1995) in the endoscopic treatment with self-expanding prosthesis (Ultraflex) of 21 patients with inoperable malignant oesophageal stenosis. 23 prosthesis were implanted enabling swallowing in less than 24 h. There were no major complications. In two occasions the prosthesis was obstructed by tumoral growth needing replacement. The prosthesis was occluded by solid food in four cases, which were resolved endoscopically.

Adenocarcinoma↗
PubMed1995

Histochemical distribution of NADPH-diaphorase in the cerebral ganglion of the crayfish Cambarellus montezumae.

The presence and localization of NADPH-diaphorase in the cerebral ganglion of the crayfish Cambarellus montezumae was shown. The reactivity of this enzyme was found in the deuterocerebrum, mainly in the commissure, in fibers of olfactory and accessory lobes, and in the laterodorsal group of cells. The presence of this enzyme in these cerebral regions suggests that nitric oxide is involved in primary sensory afferents in the crayfish.

Animals↗
PubMed1995

[Treatment and outcome of infantile cholesteatoma surgery].

Infantile Cholesteatoma has been lately the aim of a large number of papers dealing with its natural history and optimal treatment. The outcome of 26 cases of ear surgery, done between 1990 and 1991, are reviewed. The etiology of Cholesteatoma was congenital in 2 cases, iatrogenic in an other one and unknown for the remainder (88%). Fifteen (15) closed surgical procedures and 11 open were carry out, achieving global removal of lesions in 76 percent of cases. Ninety-one (91%) of open tympanoplasties and 66 percent of closed procedures. Six cases evolved to recidivation (and later reoperatively reconverted in open cases) owing either to the erosion of the ossicular chain or encroachment of the recessus. Reconstructions of the ossicular chain was undertaken in 61.5 percent of cases and the hearing preserved in all instances and improved in 35 percent of reconstructions.

Adolescent↗
PubMed1994

Distribution of NADPH-diaphorase in the perioesophageal ganglia of the snail, Helix aspersa.

In this paper we discuss the anatomical localization of NADPH-diaphorase using Nitroblue tetrazolium in perioesophageal ganglia of Helix aspersa. Our results show that the reaction is present in neurons and fibers of the procerebrum, some positive neurons are found in mesocerebrum, and there were positive fibers in the neuropile of postcerebrum and mesocerebrum; likewise, immunopositive fibers were found in the neuropile of pedal, pleural and parietal ganglia. The presence of NADPH-diaphorase in the interneurons of procerebrum suggests the participation of this enzyme in the production of nitric oxide for the processing of the olfactory information, as has been suggested in mammalian olfactory tissue.

Animals↗
PubMed1991

Naloxone effects on the visual evoked potentials recorded from the main and accessory visual pathways of the cat.

1. The effects produced by repetitive i.v. administration of naloxone (1, 2 or 4 mg/kg) on the visual evoked potentials (VEPs) recorded along the main and accessory visual pathways were investigated in a modified "encéphale isolé" cat preparation. 2. Naloxone provoked a progressive amplitude enhancement and latency reduction of some components, depending on the structure analyzed, the dose used and the number of administrations applied. Electroretinogram (ERG) and N1-P1 VEP components of optic chiasm (OCh), lateral geniculate body (LGB) and visual cortex (VC) did not present significant changes. 3. Late-latency components (more than 200 msec) appeared in the VEPs of LGB and VC, mainly when 4 mg/kg were used. 4. Our results suggest that endogenous opioids have a modulatory role in the processing of sensory information at different levels of the visual system.

Animals↗
PubMed1988

Naloxone facilitates sensory precipitation of focal and generalized seizures: evoked potentials and power spectral analysis in the cat.

To analyze the role of endogenous opioids on epileptogenesis the effect of repeated doses of naloxone alone (NA) (2, 4, and 8 mg/kg every 15 min) or along with intermittent photic stimulation (NPS) (1, 3, and 10 Hz) was tested on acute "Encephale isolé" cats. The electrical activity recordings of sensorimotor cortex (SMC), visual cortex, and right and left amygdalae revealed progressive changes as naloxone was administered: (A) slow spindle activity (4-6 Hz) in SMC, (B) 12 Hz rhythmic activity in both amygdalae, (C) generalized paroxysms, and (D) spontaneous tonic-clonic electrographic seizures. These changes occurred in both experimental groups (NA, NPS), and their onset was dose-related. Photic stimulation precipitated these phenomena. The amplitude of the visual evoked potential components (N1-P1, P1-N2, N2-P2) and power spectral analysis of spontaneous and evoked activity underwent progressive changes. Our results confirm a facilitatory effect of naloxone on epileptogenesis and suggest a possible role of endogenous opioids in this process and on sensory pathways' excitability.

Amygdala↗