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2.
Gastrointest Endosc Clin N Am ; 11(2): 387-408, viii, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11319069

RESUMEN

Achalasia in children bears many similarities to the disorder in adults, both in terms of clinical features and in terms of the approach to therapy. Pharmacologic management is of limited temporary benefit until more definitive therapy is undertaken. Intrasphincteric injections of botulinum toxin provides safe but short-term relief from symptoms. Based on our review of the safety and effectiveness of pneumatic dilation, we advocate this procedure as the primary form of definitive therapy for achalasia in children. In patients who do not achieve satisfactory results from a series of graduated pneumatic dilations, Heller myotomy provides safe and effective surgical treatment.


Asunto(s)
Acalasia del Esófago/etiología , Acalasia del Esófago/terapia , Adolescente , Factores de Edad , Toxinas Botulínicas Tipo A/uso terapéutico , Niño , Preescolar , Diagnóstico Diferencial , Dilatación , Acalasia del Esófago/diagnóstico , Acalasia del Esófago/epidemiología , Femenino , Humanos , Lactante , Masculino , Músculo Liso/cirugía , Fármacos Neuromusculares/uso terapéutico , Selección de Paciente , Pediatría/métodos , Seguridad , Resultado del Tratamiento
3.
J Pharmacol Exp Ther ; 282(3): 1373-8, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9316849

RESUMEN

Previous electrophysiological studies have shown that tachykinin-mediated excitatory junction potentials are enhanced in a ricin model of inflammatory bowel disease. The present study extends these findings by investigating the contractile response to stimulation of noncholinergic nerves and tachykinin agonists. According to rank order potencies, the rabbit ileal circular muscle was neurokinin (NK)1 preferring, and the response to these agonists was down-regulated by acetylcholine and up-regulated by nitric oxide. In ricin-treated tissue, cholinergic and nitridergic modulation was lost; in the presence of atropine and N-nitro-L-arginine methyl ester, or tetrodotoxin, the response to NK1 and NK2 agonists was enhanced. The noncholinergic response to nerve stimulation was predominantly mediated by NK1 receptors, and the enhanced response of ricin-treated tissue to NK1 agonists probably contributes to the increased response to electrical field stimulation observed under these conditions. Increased tachykinin response and loss of control of this response by acetylcholine and nitric oxide are likely to have profound effects on intestinal motility and could contribute to some of the symptomology of inflammatory bowel disease.


Asunto(s)
Ileítis/fisiopatología , Transmisión Sináptica , Taquicininas/farmacología , Acetilcolina/farmacología , Animales , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Masculino , Contracción Muscular/efectos de los fármacos , Conejos , Ricina/farmacología
4.
Am J Physiol ; 273(2 Pt 1): G447-55, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9277424

RESUMEN

The role of sensory afferents in inflammation-induced alterations in myoelectric activity in vivo was investigated in the rabbit small intestine. Isolated ileal loops were implanted with serosal electrodes and exposed to ricin or vehicle after pretreatment with 125 mg/kg of subcutaneous (125 mg over 3 days) or intraluminal (640 microM) capsaicin. After 5 h of myoelectric recording, the loops were prepared for histology and for ex vivo generation of eicosanoids. Capsaicin exacerbated mucosal damage after exposure to ricin but did not alter neutrophil infiltration. Subcutaneous capsaicin alone elevated slow-wave frequency and spike events and transiently suppressed the myoelectric response to ricin. In contrast, intraluminal capsaicin alone did not alter myoelectric activity but produced a sustained inhibition of the response to ricin. Eicosanoid production was unchanged by capsaicin alone. Intraluminal capsaicin blocked increases in leukotriene C4 and prostaglandin E2 during inflammation, an effect that paralleled its inhibition of myoelectric activity. Thus the contribution of sensory afferents to altered motility during acute ileitis involves the release of mucosal inflammatory mediators that influence neural control of smooth muscle.


Asunto(s)
Ileítis/fisiopatología , Íleon/fisiopatología , Músculo Liso/fisiopatología , Neuronas Aferentes/fisiología , Enfermedad Aguda , Animales , Capsaicina/farmacología , Eicosanoides/biosíntesis , Electrofisiología , Ileítis/inducido químicamente , Ileítis/metabolismo , Íleon/metabolismo , Íleon/patología , Técnicas In Vitro , Masculino , Músculo Liso/metabolismo , Músculo Liso/patología , Conejos , Ricina
7.
Am J Physiol ; 260(2 Pt 1): G232-9, 1991 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1996644

RESUMEN

The myenteric plexus consists of several subpopulations of morphologically and chemically distinct neurons known to contain a variety of peptides and amines, one of which is serotonin (5-hydroxytryptamine). These neurons are considered essential for nerve-to-nerve transmission. In the present study, we investigated the effect of 5,6- and 5,7-dihydroxytryptamine (5,6-DHT; 5,7-DHT), indoleamine neurotoxins that selectively and irreversibly injure the serotonergic neurons of the myenteric plexus. Treatment with 5,6-, or 5,7-DHT caused marked disruption of the activity front of the migrating myoelectric complex (MMC), increased its duration, and decreased its propagation velocity. At higher doses, 5,7-DHT also reduced the slow-wave frequency. Immunohistochemical techniques showed that tissue from rats treated with 5,7-DHT was depleted of serotonin-like immunoreactivity within the myenteric plexus neurons. Reserpine also caused motility and immunohistochemical changes similar to those induced by the two neurotoxins. Therefore, destruction of enteric serotonergic neurons disrupts the MMC. These studies support the cellular concepts that serotonergic neurons function as interneurons in the myenteric plexus, modulating and processing the neural stimuli, and that serotonin is an important neurotransmitter in the small intestine.


Asunto(s)
Motilidad Gastrointestinal , Yeyuno/inervación , Músculo Liso/inervación , Plexo Mientérico/fisiología , Complejo Mioeléctrico Migratorio/fisiología , Neuronas/fisiología , Serotonina/fisiología , 5,6-Dihidroxitriptamina/toxicidad , 5,7-Dihidroxitriptamina/toxicidad , Potenciales de Acción/efectos de los fármacos , Animales , Yeyuno/fisiología , Masculino , Músculo Liso/fisiología , Plexo Mientérico/efectos de los fármacos , Plexo Mientérico/patología , Complejo Mioeléctrico Migratorio/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/patología , Neurotoxinas , Ratas , Ratas Endogámicas , Serotonina/análisis , Factores de Tiempo
8.
Am J Dis Child ; 143(12): 1424-7, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2686400

RESUMEN

Review of our experience from 1975 to 1986 and a literature survey disclosed 109 children with pyogenic liver abscess. During this time, newer imaging techniques, especially ultrasonography and computed tomography, facilitated the prompt diagnosis of cystic lesions within the liver parenchyma. The incidence of pyogenic liver abscess at our institution (25 per 100,000 pediatric hospital admissions) was higher than previously reported. Since the majority of abscesses were located in the right lobe of the liver, patients were most effectively treated with percutaneous drainage of the abscess cavity. Staphylococcus aureus was the most common bacterial agent responsible for pyogenic liver abscess; however, anaerobic organisms were noted as a major group of pathogens and represented 27% of our patients. Furthermore, one patient was discovered to have multiple microabscesses of the liver associated with cat-scratch disease; pleomorphic gram-negative bacilli were not cultured. Among the 109 patients, the overall mortality of 15% was considerably better than that for children with PLA before 1975. The improved survival may be related to more prompt diagnosis of pyogenic liver abscess followed by evacuation of the liver abscess and antibiotic therapy.


Asunto(s)
Absceso Hepático/epidemiología , Infecciones Estafilocócicas/epidemiología , Adolescente , Antibacterianos/uso terapéutico , Niño , Preescolar , Drenaje , Femenino , Fiebre/tratamiento farmacológico , Humanos , Lactante , Absceso Hepático/diagnóstico , Absceso Hepático/etiología , Absceso Hepático/mortalidad , Absceso Hepático/terapia , Masculino , Morbilidad , Estudios Retrospectivos , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/etiología , Infecciones Estafilocócicas/mortalidad , Infecciones Estafilocócicas/terapia , Ultrasonografía
9.
Am J Physiol ; 256(3 Pt 1): G598-603, 1989 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2923216

RESUMEN

The migrating myoelectric complex (MMC) is demonstrated in four avian species: three gallinaceous birds (Gallus, Phasianus, Coturnix) and an owl (Strix). The complex in birds is strikingly similar to the MMC that is known in mammalian species. It has the same basic pattern of quiescence, followed by a period of irregular spike activity, then a period of intense regular spike activity, and finally a return to quiescence. The frequency and duration of avian MMCs are similar to those of mammals, but the propagation velocity and slow-wave frequency are slower. Granivorous birds (Gallus, Phasianus) and carnivores (Strix) exhibit the same basic motility patterns whether in the fed or fasted states. Interspecific differences occur, however, in the details of frequency, propagation velocity, duration, and slow-wave frequency. The closely related galliforms (chickens, pheasants) are more similar to each other in MMC characteristics than either is to the more distantly related owls.


Asunto(s)
Aves/fisiología , Íleon/inervación , Plexo Mientérico/fisiología , Potenciales de Acción , Animales , Coturnix/fisiología , Conductividad Eléctrica , Masculino
10.
J Pediatr ; 113(5): 820-5, 1988 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3183834

RESUMEN

To determine whether motor activity of the stomach and proximal small intestine is a factor in recurrent abdominal pain in adolescents, we prospectively investigated eight patients with recurrent abdominal pain and compared them with seven normal adolescents. All patients underwent a detailed examination to exclude other known organic causes of the pain. The gastroduodenal motor activity during fasting was studied with a semiconductor recording probe. The recordings were analyzed for periodicity, duration, and propagation velocity of the activity front of the migrating motor complex. The amplitude of the antral and duodenal contractions was also determined. The patients with recurrent abdominal pain had more frequent migrating motor complexes, but these were shorter in duration and moved more slowly down the intestine (slower propagation velocities). The patients also had high-pressure duodenal contractions that were associated with abdominal pain during the study period. These studies suggest that altered intestinal motility may be the underlying mechanism of recurrent abdominal pain in some children.


Asunto(s)
Abdomen , Motilidad Gastrointestinal , Dolor/etiología , Adolescente , Niño , Duodeno/fisiopatología , Femenino , Humanos , Masculino , Estudios Prospectivos , Antro Pilórico/fisiopatología , Recurrencia
11.
J Pediatr ; 110(2): 187-9, 1987 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3806288

RESUMEN

The efficacy of thickened feedings for the treatment of gastroesophageal reflux in infancy was evaluated. Fifty-two infants were examined with prolonged pH monitoring of the distal esophagus after feedings of apple juice or apple juice thickened with rice cereal. All infants had a minimum of three feedings of both thickened and unthickened juice. The recordings of distal esophageal pH were analyzed for the percent of time the pH was less than 4 in the first 2 hours after each feeding. The infants were maintained in the following positions after feeding: prone (n = 29), prone-board with the head elevated 30 degrees from horizontal (n = 29), supine (n = 7), and unrestricted (n = 21). We found no significant difference in the percent of time with reflux with thickened versus unthickened feedings except in those infants maintained in the 30-degree prone position. In the first 2 hours after eating thickened juice, infants maintained in this position had increased esophageal reflux time (P less than 0.006). Further analysis revealed that 33% of the infants had a greater than 30% increase in esophageal reflux time after thickened feedings. Our study suggests that the immediate effect of thickened feedings on gastroesophageal reflux in infants is unpredictable.


Asunto(s)
Reflujo Gastroesofágico/dietoterapia , Alimentos Infantiles , Humanos , Lactante , Recién Nacido , Estudios Prospectivos
12.
Am J Physiol ; 249(3 Pt 1): G416-21, 1985 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3929621

RESUMEN

We have previously described the myoelectric characteristics of a single moving ring contraction, the migrating action potential complex (MAPC), in rabbit ileal loops exposed to certain bacteria or their enterotoxins. The MAPC is thought to act as a defense mechanism of the host, clearing unwanted substances from the lumen. In the present study, 6-hydroxydopamine, a substance that selectively destroys adrenergic varicosities containing the neurotransmitter norepinephrine, unmasked the MAPC from the activity front of the migrating motor complex in an unanesthetized rat model. The animals developed diarrhea and lost weight. The study suggests that the MAPC may also be a physiological complex and under the modulation of the enteric nervous system. The MAPC may not be seen under normal control conditions because the complex migrates with the activity front and is under inhibitory control. Destroying the inhibitory mechanisms unmasked the MAPC from the activity front of the migrating motor complex and allowed neural transmission of the ring contraction.


Asunto(s)
Motilidad Gastrointestinal/efectos de los fármacos , Hidroxidopaminas/farmacología , Intestino Delgado/fisiología , Contracción Muscular/efectos de los fármacos , Músculo Liso/fisiología , Potenciales de Acción/efectos de los fármacos , Animales , Técnicas In Vitro , Masculino , Oxidopamina , Ratas , Ratas Endogámicas
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