Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Mol Cell Biochem ; 194(1-2): 185-91, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10391139

RESUMEN

The ability of the gastrointestinal (GI) tract, as well as other tissues, to cope with reactive oxygen species (ROS) efflux in pathological events is determined partly by epithelial antioxidant levels. These levels are comprised of tissue antioxidant enzymes and low molecular weight antioxidants (LMWA). While glutathione levels and the activity of enzymatic antioxidants along the GI tract have been studied, the contribution of the overall LMWA to the total antioxidant capacity has not yet been determined. In this study the overall antioxidant activity in the mucosa/submucosa and muscularis/serosa of various sections along the small intestine and colon of the rat was evaluated by determining the reducing power, which reflects the total antioxidant activity derived from LMWA, using cyclic voltammetry. The activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase was also measured. The reducing power (total antioxidant activity) was higher in the mucosa/submucosa of the small intestine as compared to the mucosa/submucosa of the colon. Similarly, catalase and SOD activity in the mucosa/submucosa of the small intestine was significantly higher than in the mucosa/submucosa of the colon. Differences were also observed in the reducing power and SOD activity in the muscularis/serosa of the rat small intestine as compared to the colon. The low antioxidant capacity in the colon may facilitate reactive oxygen species (ROS)-mediated injury and lead to inflammatory diseases such as ulcerative colitis, specifically in the colon.


Asunto(s)
Antioxidantes/metabolismo , Colon/metabolismo , Sistema Digestivo/metabolismo , Animales , Catalasa/metabolismo , Colon/enzimología , Sistema Digestivo/enzimología , Electroquímica , Peróxido de Hidrógeno/metabolismo , Mucosa Intestinal/enzimología , Mucosa Intestinal/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Superóxido Dismutasa/metabolismo
2.
Am J Physiol ; 273(4): G785-94, 1997 10.
Artículo en Inglés | MEDLINE | ID: mdl-9357819

RESUMEN

The aim of this study was to investigate whether the blockade of L-type Ca2+ channels with verapamil suppresses giant migrating contractions (GMCs) and therefore diarrhea during small intestinal inflammation. Small intestinal inflammation was induced by infection with the nematode Trichinella spiralis. T. spiralis infection alone significantly increased the frequency of GMCs and decreased the frequency of phase III activity in the small intestine for 9 days. The increased frequency of GMCs was associated with diarrhea. Immunohistochemical staining with specific antibodies indicated that the number of neutrophils and mast cells increased significantly in the jejunal lamina propria during T. spiralis infection. Only the neutrophils increased significantly in the muscularis externa of the jejunum. Myeloperoxidase (MPO) activity increased significantly in the jejunal and ileal lamina propria. Daily verapamil administration during T. spiralis infection significantly reduced the frequency of GMCs and diarrhea but had no further significant effect on the already reduced frequency of phase III activity. Verapamil administration, however, did not reduce MPO activity or immunocyte infiltration in the jejunum or ileum. We conclude that blockade of L-type Ca2+ channels selectively reduces the frequency of GMCs and therefore diarrhea during small intestinal inflammation. The decreased frequency of GMCs is not secondary to a reduction in the inflammatory response.


Asunto(s)
Bloqueadores de los Canales de Calcio/farmacología , Diarrea/prevención & control , Parasitosis Intestinales/fisiopatología , Intestino Delgado/fisiopatología , Músculo Liso/fisiopatología , Complejo Mioeléctrico Migratorio/efectos de los fármacos , Trichinella spiralis , Triquinelosis/fisiopatología , Verapamilo/farmacología , Animales , Canales de Calcio/fisiología , Canales de Calcio Tipo L , Perros , Inflamación , Intestino Delgado/efectos de los fármacos , Intestino Delgado/fisiología , Mastocitos/fisiología , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Complejo Mioeléctrico Migratorio/fisiología , Neutrófilos/fisiología , Factores de Tiempo
3.
Gut ; 41(3): 375-80, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9378395

RESUMEN

BACKGROUND: The possible role of nitric oxide in the regulation of the sphincter of Oddi is not known in species with a resistor-like sphincter of Oddi such as humans and pigs. METHODS: Sphincter of Oddi perfusion manometry and simultaneous electromyography (EMG) were recorded transduodenally in eight anaesthetised pigs. Acetylcholine (4 micrograms/kg) was given intra-arterially, with or without sodium nitroprusside (10-100 micrograms/kg), an exogenous nitric oxide donor. For in vitro studies the sphincter was removed from the eight pigs and from six patients undergoing pancreaticoduodenectomy, cut into rings, and the amplitude of contraction was measured in an ex vivo bath. Each ring was stimulated with acetylcholine (100 microM) and KCl (125 mM). The stimulation was repeated after incubation with L-NAME (a stereospecific competitive inhibitor of nitric oxide synthase), with L-NAME plus L-arginine (a substrate for nitric oxide synthase), and with sodium nitroprusside. The sphincter rings were then submersed in liquid nitrogen and stored. Immunohistochemical analysis was used to localise nitric oxide synthase in the pig and human sphincter specimens. RESULTS: In vivo EMG revealed 2-3 phasic bursts per minute with the basal pressure variation 6-40 mm Hg. Acetylcholine induced a large electrical burst and the pressure increased by (mean (SE)) 20 (10) mm Hg (p < 0.01) for 17 (4) seconds. After sodium nitroprusside (10 micrograms/kg) acetylcholine did not induce pressure changes and electrical activity was almost abolished. In vitro, L-NAME increased the KCl induced sphincter contraction in both pig and human specimens (p < 0.01). In human, but not in pig, specimens L-NAME increased the amplitude of acetylcholine induced contraction (p < 0.01). L-Arginine partly reversed the effect of L-NAME in both pig and human specimens. Sodium nitroprusside decreased the acetylcholine and KCl induced contractions in both pig and human specimens. Immunohistochemical studies localised nitric oxide synthase to rich plexi of nerve fibres in the mucosa and the muscle in both pig and human sphincter of Oddi. CONCLUSIONS: The sphincter of Oddi in both pigs and humans has endogenous nitric oxide synthase activity and immunoreactivity. Inhibition of endogenous nitric oxide production enhances contractility while exogenous nitric oxide decreases sphincter contractility and electrical activity.


Asunto(s)
Óxido Nítrico/fisiología , Esfínter de la Ampolla Hepatopancreática/fisiología , Acetilcolina/farmacología , Animales , Arginina/farmacología , Electromiografía , Femenino , Humanos , Inmunohistoquímica , Técnicas In Vitro , Manometría , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/análisis , Óxido Nítrico Sintasa/antagonistas & inhibidores , Nitroprusiato/farmacología , Cloruro de Potasio/farmacología , Esfínter de la Ampolla Hepatopancreática/enzimología , Porcinos , Vasodilatadores/farmacología
4.
Neurogastroenterol Motil ; 8(4): 351-61, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8959739

RESUMEN

Benzyldimethyltetradecylammonium chloride (BAC) has previously been used to create amyenteric rat jejunal models. Fifteen opossums (D. virginiana) were injected with 10-15 mL 4 mM BAC or saline in the distal oesophagus and along with controls underwent oesophagoscopy, manometry and barium oesophagrams. Atropine and sodium nitroprusside were studied in six of the BAC-treated and five controls using oesophageal manometry. Histologically several neuronal markers, B-NADPH-diaphorase and acetylcholine esterase histochemical staining were used. NADPH-diaphorase activity was assayed at the lower oesophageal sphincter (LOS) and 3 and 5 cm above LOS in both groups. Oesophagoscopy of the treated animals showed no mucosal inflammation, or strictures. Manometrically, LOS pressures were significantly higher in the BAC-treated group (25.7 +/- 8.6 mmHg) when compared to controls (8.7 +/- 1.8 mmHg). The oesophageal contraction amplitudes were similar in both groups. While sodium nitroprusside (SNP) significantly reduced the LOS pressure, atropine did not alter the resting LOS pressure in the BAC-treated animals. Histologically at the LOS the treated group showed: (i) absence of myenteric neurons, in contrast to prominent NADPH-diaphorase and other neuron and peptide markers in the control and (ii) increase in the number of nerve bundles that were not positive for AchE. No differences were seen in the oesophageal body between the groups. The NADPH-diaphorase assay showed a significant decrease of activity in the BAC-treated LOS, but no differences in the oesophageal body compared to controls. Several of these radiologic, manometric and histological observations resemble features of achalasia and the mechanism of the tonic pressure increase at this early time point appears to be due to a non-cholinergic mechanism.


Asunto(s)
Acalasia del Esófago/fisiopatología , Animales , Modelos Animales de Enfermedad , Femenino , Histocitoquímica , Masculino , NADPH Deshidrogenasa/metabolismo , Zarigüeyas , Ratas
6.
Neuropeptides ; 30(4): 385-90, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8914866

RESUMEN

Colonic mucosal cells are known to contain several neuropeptides. The distribution of various peptide-containing cells in the colon and their possible modulation by aging and diet are unknown. We quantitated various peptide-containing cells from male Lobund-Wistar rat colon at 2, 22, 28, 30 and 33 months of age using indirect immunohistochemical techniques for several peptides including: neuropeptide Y, peptide YY, somatostatin, and chromogranin A. Four diets, varying in total calories and fat content, were examined. Serum gastrin was quantified by RIA at 2 and 33 months. Only NPY-, PYY- and SOM-positive cells were found in the colon. The number per crypt of neuropeptide Y-positive (0.55 +/- 0.04 at 2 months vs 0.80 +/- 0.22 at 33 months, P = 0.015) and peptide YY-positive cells increased with age. Staining for somatostatin and chromogranin, a marker for all enterochromaffin (EC) cells, revealed no change with aging. Diet did not influence the numbers of any peptide-containing cell. Serum gastrin was not different between the groups. A specific increase in NPY- and PYY-positive cells occurs in the aged rat colon. The extent to which this change may be related to age-related colonic dysmotility seen in elderly humans is worthy of exploration.


Asunto(s)
Envejecimiento/metabolismo , Colon/química , Neuropéptido Y/análisis , Péptidos/análisis , Envejecimiento/patología , Animales , Recuento de Células , Cromogranina A , Cromograninas/análisis , Colon/citología , Masculino , Péptido YY , Ratas , Ratas Wistar , Somatostatina/análisis
7.
Dis Colon Rectum ; 39(7): 817-22, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8674377

RESUMEN

PURPOSE: Unlike classic Hirschsprung's disease, short-segment and ultrashort-segment varieties are usually found to be latent and milder. Ultrashort-segment Hirschsprung's disease may present as intractable chronic constipation in children over one year of age, adolescents, and adults. Anorectal myectomy has been shown in many instances to provide effective long-term treatment for certain patients with ultrashort-segment Hirschsprung's disease. Histologically, the affected segment in Hirschsprung's disease has been shown to have increased cholinergic nerves, lack of nitric oxide synthase-containing neuronal elements, and show moderate to severe loss of myenteric neurons. METHODS: Here, we report three cases that showed clinical and manometric evidence of ultrashort-segment Hirschsprung's disease. Two of the three patients responded well to myectomy. RESULTS: Detailed histologic and immunohistochemical evaluation of the internal anal sphincter and a comparison with three normal controls revealed absence of nitric oxide synthase-containing neurons in both cases that responded well to surgery and continued presence of these neurons in the patient who did not respond. A review of the current literature on various treatment modalities is included. CONCLUSIONS: Anorectal myectomy provides long-term relief of this chronic problem in a subgroup of patients with ultrashort-segment Hirschsprung's disease who lack nitrinergic neurons at the internal anal sphincter.


Asunto(s)
Colon/patología , Enfermedad de Hirschsprung/patología , Adolescente , Adulto , Canal Anal/patología , Biopsia , Estreñimiento/patología , Femenino , Humanos , Inmunohistoquímica , Masculino
8.
Cell Immunol ; 171(1): 132-9, 1996 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-8660848

RESUMEN

Murine T cell receptor (TCR) alpha beta intestinal intraepithelial lymphocytes (IEL), which express the CD8 molecule as a homodimer (CD8 alpha alpha), can be divided into two subsets: those which are CD4+ (CD4+CD8+alpha alpha) and those which are CD4- (CD4-CD8+alpha alpha). Here, we demonstrate that most TCR alpha beta CD4+CD8+alpha alpha IEL and TCR alpha beta CD4-CD8+alpha alpha IEL subsets appear to be of thymus origin, as neonatal thymectomy of BALB/c mice on Day 3 nearly eliminated both subsets. To further support this hypothesis, we demonstrate by grafting the thymus of CBF1 (BALB/c x C57BL/6) mice into nude mice that the thymus is capable of generating both TCR alpha beta CD4-CD8+alpha alpha IEL and TCR alpha beta CD4+CD8+alpha alpha IEL. However, which of the two TCR alpha beta IEL subsets is generated depends largely on the age of the thymus. The thymus from fetal up to 2 weeks of age generates predominantly TCR alpha beta CD4-CD8+alpha alpha IEL, but very scant amounts CD4+CD8+alpha alpha IEL. In contrast, the thymus after 2 weeks of age generates very little TCR alpha beta CD4-CD8+alpha alpha IEL, but generates an abundant amount of TCR alpha beta CD4+CD8+alpha alpha IEL. These results are consistent with the observation in euthymic mice that TCR alpha beta CD4-CD8+alpha alpha IEL precede the appearance of TCR alpha beta CD4+CD8+alpha alpha IEL by several weeks, thus further suggesting that the thymus is the major source of both TCR alpha beta IEL subsets.


Asunto(s)
Mucosa Intestinal/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/análisis , Subgrupos de Linfocitos T/citología , Timo/crecimiento & desarrollo , Timo/inmunología , Envejecimiento/inmunología , Animales , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/inmunología , Desarrollo Embrionario y Fetal/inmunología , Células Epiteliales , Epitelio/inmunología , Mucosa Intestinal/citología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Modelos Inmunológicos , Especificidad de la Especie , Subgrupos de Linfocitos T/clasificación , Timo/trasplante
9.
Gastroenterol Clin North Am ; 25(1): 183-201, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8682572

RESUMEN

The gut is abundantly supplied with neurons, extrinsic and intrinsic nerve fibers. Knowledge regarding the structure of the enteric nervous system derives principally from the classic silver-staining methods. Because silver stains do not provide information on the molecular constituents of neurons, these data only facilitate classification and may have diagnostic significance. Studies using histochemistry and immunohistochemistry are now completing the morphologic picture and laying the groundwork for the formulation of therapeutic strategies based upon demonstrable chemical defects in enteric disease.


Asunto(s)
Sistema Nervioso Entérico/patología , Colorantes , Motilidad Gastrointestinal , Histocitoquímica , Humanos , Inmunohistoquímica , Plexo Mientérico/patología , Plata
10.
Am J Physiol ; 269(6 Pt 1): G913-24, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8572223

RESUMEN

Infiltration of specific immunocytes and stimulation of abnormal gastrointestinal motor activity during ileal inflammation induced by mucosal exposure to ethanol and acetic acid were investigated in 17 dogs. Ileal inflammation significantly increased the frequency of giant migrating contractions (GMCs) and decreased the frequency of migrating motor complexes (MMCs). The frequency of retrograde giant contractions (RGCs) increased only on the day of ethanol and acetic acid treatment. Diarrhea, urgency of defecation, and apparent abdominal discomfort were related to the increased frequency of GMCs. Ileal inflammation also prolonged the duration of postprandial MMC disruption. Histological and immunohistochemical findings indicated transmural inflammation with marked increase in polymorphonuclear cells in the lamina propria and muscularis externa layers. Myeloperoxidase activity increased severalfold in both layers. Cells containing interleukin-2 receptor (IL-2R) increased in the lamina propria. Other immunocytes, such as B and T lymphocytes, dendritic cells, and human leukocyte antigen DR-1 (HLADR)-positive cells, did not exhibit a significant increase in the inflamed ileum compared with the normal proximal jejunum. We conclude that stimulation of GMCs may be the major motility marker of intestinal inflammation.


Asunto(s)
Motilidad Gastrointestinal , Ileítis/inmunología , Ileítis/fisiopatología , Sistema Inmunológico/fisiología , Animales , Perros , Femenino , Ileítis/patología , Sistema Inmunológico/patología , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Intestino Delgado/fisiopatología , Intestinos/patología , Masculino , Contracción Muscular , Complejo Mioeléctrico Migratorio , Peroxidasa/metabolismo
11.
J Immunol ; 155(9): 4224-30, 1995 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7594578

RESUMEN

Present evidence suggests that cyclosporin A (CSA) inhibits the development of both alpha beta and gamma delta T cells in the thymus. However, whether CSA can inhibit the development of murine intestinal intraepithelial lymphocytes (i-IEL) is unknown as most i-IEL are clearly derived from a different lineage than the conventional thymus-derived T cells found in the periphery. Using the adult thymectomized, lethally irradiated bone-marrow reconstituted chimera (ATXBM mice) as a model for the development of extrathymically derived i-IEL and the fetal thymus-grafted (FTG) nude mice as a model for the development of thymically derived i-IEL, we demonstrate that CSA nearly completely inhibited the development of extrathymically, and possibly thymically, derived TCR-alpha beta i-IEL. Most of the TCR-alpha beta i-IEL whose development was inhibited by CSA belonged to the CD4-CD8+ alpha alpha subset. In contrast, the development of extrathymically and thymically derived TCR-gamma delta i-IEL was completely resistant to CSA. The phenotype of CSA-resistant TCR-gamma delta i-IEL in these models was not different from those in control mice, and the TCR-gamma delta i-IEL in CSA-treated mice appear to be mature and activated as most were large, granular, and CD69+. Lastly, we demonstrate that CSA does not affect the extrathymic positive selection of V delta 4 i-IEL in C3H hosts. These results suggest that despite their similarity, the intracellular activation cascade involved after TCR stimulation between TCR-alpha beta CD4-CD8+ alpha alpha and TCR-gamma delta CD4-CD8+ alpha alpha i-IEL are markedly different.


Asunto(s)
Ciclosporina/farmacología , Inmunosupresores/farmacología , Mucosa Intestinal/efectos de los fármacos , Receptores de Antígenos de Linfocitos T alfa-beta/efectos de los fármacos , Receptores de Antígenos de Linfocitos T gamma-delta/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Animales , Diferenciación Celular/efectos de los fármacos , Feto , Inmunidad Innata , Mucosa Intestinal/inmunología , Activación de Linfocitos/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Desnudos , Timo/trasplante
12.
Lancet ; 346(8979): 861-4, 1995 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-7564669

RESUMEN

Clinical studies suggest that gut disorders are common in Parkinson's disease, but the morphological basis is unknown. Depletion of dopamine-containing neurons in the central nervous system is a basic defect in Parkinson's disease. We compared colonic tissue from 11 patients with advanced Parkinson's disease, 17 with adenocarcinoma (normal tissue was studied), and five who underwent colectomy for severe constipation. Immunohistochemistry was used to stain myenteric and submucosal neurons for dopamine, tyrosine hydroxylase, and vasoactive intestinal polypeptide (VIP). Each class of neurons was quantified as a percentage of the total neuronal population stained for the marker protein gene product 9.5. Nine of the 11 Parkinson's disease patients had substantially fewer dopaminergic myenteric neurons than the other subjects (mean 0.4 [SE 0.2] vs 6.9 [2.3] in controls and 5.7 [2.0] in constipated subjects). There was very little difference between the groups in numbers of tyrosine-hydroxylase and VIP neurons. Two Parkinson's disease patients had similar distributions of all types of neurons, including dopaminergic myenteric neurons, to the controls. High-performance liquid chromatography showed lower levels of dopamine in the muscularis externa (but not mucosa) in four Parkinson's disease patients than in four controls (7.3 [5.1] vs 24.2 [4.6] nmol per g protein), but levels of dopamine metabolites were similar in the two groups. The identification of this defect of dopaminergic neurons in the enteric nervous system in Parkinson's disease may lead to better treatment of colorectal dysfunction in this disease.


Asunto(s)
Colon/inervación , Estreñimiento/complicaciones , Dopamina/análisis , Sistema Nervioso Entérico/química , Neuronas/química , Enfermedad de Parkinson/complicaciones , Adenocarcinoma/patología , Anciano , Enfermedad Crónica , Colectomía , Colon/química , Colon/patología , Neoplasias del Colon/patología , Estreñimiento/metabolismo , Estreñimiento/patología , Dopamina/metabolismo , Humanos , Persona de Mediana Edad , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Tirosina 3-Monooxigenasa/metabolismo , Tirosina 3-Monooxigenasa/fisiología
13.
Gastroenterology ; 109(3): 789-99, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7657107

RESUMEN

BACKGROUND & AIMS: Achalasia is characterized by loss of myenteric neurons and incomplete relaxation of the lower esophageal sphincter (LES). The aim of this study was to develop an achalasia model in the opossum using the surfactant benzyldimethyltetradecylammonium chloride (BAC). This study further characterizes the achalasia model. METHODS: BAC or saline was injected circumferentially into the LES of 14 adult opossums. Eight months after injection, manometry, isolated muscle bath studies, electrical field stimulation, and histochemical analysis were performed. RESULTS: Manometrically, the LES of BAC-treated opossums showed higher pressures (38.7 +/- 12 mm Hg vs. 17 +/- 3.0 mm Hg) and reduced esophageal body contraction amplitudes (4.2 +/- 3 mm Hg vs. 27.4 +/- 12 mm Hg). Isolated muscle strips challenged with carbachol and sodium nitroprusside contracted and relaxed similarly to controls. Electrical field stimulation failed to induce relaxation in BAC-treated tissue but did induce contraction. Contractile responses were markedly reduced by tetrodotoxin and atropine in BAC-treated animals and controls. An altered nitric oxide system was shown by the lack of response to L-arginine and N omega-nitro-L-arginine. Histology showed loss of myenteric neurons and increased cholinergic nerve bundles. CONCLUSIONS: Loss of NO inhibitory myenteric neurons markedly reduces the relaxation of the LES, and histology and pharmacological responses suggest a proliferation of cholinergic nerves into the LES contributing to the static elevated pressures of the amyenteric LES.


Asunto(s)
Unión Esofagogástrica/fisiopatología , Análisis de Varianza , Animales , Arginina/farmacología , Atropina/farmacología , Compuestos de Benzalconio , Fibras Colinérgicas/efectos de los fármacos , Desnervación , Modelos Animales de Enfermedad , Estimulación Eléctrica , Electrofisiología , Acalasia del Esófago/inducido químicamente , Acalasia del Esófago/metabolismo , Acalasia del Esófago/fisiopatología , Unión Esofagogástrica/efectos de los fármacos , Unión Esofagogástrica/inervación , Femenino , Técnicas In Vitro , Masculino , Manometría , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Plexo Mientérico/efectos de los fármacos , Plexo Mientérico/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Óxido Nítrico/metabolismo , Zarigüeyas , Presión , Tetrodotoxina/farmacología
14.
Am J Gastroenterol ; 90(9): 1508-10, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7661179

RESUMEN

Diversion colitis is an inflammatory condition that develops in the excluded segment of colon after surgical diversion. Inflammatory changes include aphthous-type ulcerations, crypt abscesses, and mucosal friability. These features may be seen in other inflammatory diseases of the colon, making diagnosis difficult. Even though symptoms such as cramping pain, bleeding, and mucous discharge have been described with diversion colitis, most cases are asymptomatic. In this article we report a patient who presented with sepsis secondary to severe diversion colitis with several large (2-4 cm in diameter), deep ulcerations and air in the colonic wall, requiring colectomy.


Asunto(s)
Colitis/etiología , Colostomía/efectos adversos , Colectomía , Colitis/patología , Colon/patología , Femenino , Humanos , Persona de Mediana Edad , Sepsis/etiología , Úlcera/etiología , Úlcera/patología
15.
Gastroenterology ; 109(1): 275-81, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7541000

RESUMEN

Congenital esophageal stenosis (CES) is a rare disorder with narrowed esophageal lumen that presents as dysphagia from childhood and that is often associated with tracheobronchial remnants or webs. The pathogenesis of CES is unknown. The aim of this study was to examine the histological and immunohistochemical features of CES. Esophagi from 2 young adults with CES and 3 controls with no motility disorders underwent routine H&E staining, trichrome staining for collagen, and detailed immunocytochemical studies for general neuronal markers (protein gene product 9.5, neuron-specific enolase, and S-100) and neurotransmitters (vasoactive intestinal polypeptide, substance P, and galanin) and nitric oxide synthase by beta-nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase and a specific NO synthase antibody. Quantitative experiments compared the numbers of myenteric neurons and amounts of fibers at the circular muscle. CES esophagi showed infiltration of neutrophils in the myenteric plane, without any increase in collagen. NADPH-diaphorase histochemistry showed a significant reduction of myenteric nitrinergic neurons (7 +/- 3.4 vs. 2.7 +/- 1.8 neurons per high-power field) and fibers at the circular muscle. Other peptidergic neurons studied were not significantly reduced in CES. The specific total lack of NO inhibitory innervation may be an important mechanism in the pathogenesis of stenosis and aperistalsis of the esophagus in this disorder.


Asunto(s)
Estenosis Esofágica/congénito , Esófago/inervación , Neuropéptidos/metabolismo , Óxido Nítrico/metabolismo , Adulto , Aminoácido Oxidorreductasas/metabolismo , Estenosis Esofágica/patología , Esófago/patología , Humanos , Inmunohistoquímica , Masculino , Plexo Mientérico/metabolismo , Neuronas/metabolismo , Neutrófilos/patología , Óxido Nítrico Sintasa
16.
Neuropeptides ; 29(1): 1-9, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7566507

RESUMEN

The distribution and colocalization of nitrinergic and peptidergic nerves were examined in six human colons. The tissues were fixed, cryosectioned, and standard immunohistochemistry was performed for several known neuropeptides. The same sections were stained for NADPH-diaphorase to denote nitric oxide synthase. NADPH-diaphorase-positive myenteric neurons were counted and colocalization noted for each peptide, as well as for peptide terminations. Galanin was the only neuropeptide that colocalized to a significant extent (23.0 +/- 7.21%) with NADPH-diaphorase-positive myenteric neurons. Many neuropeptide-containing nerve fibers had extensive terminations onto NADPH-diaphorase-positive neurons. Vasoactive intestinal peptide was the only neuropeptide that colocalized with NADPH-diaphorase to any extent in nerve fibers within circular muscle (59.5 +/- 9.3%). Fiber distribution in the longitudinal muscles showed a similar, but less dense pattern. These observations provide morphological evidence for the presence of nitric oxide, a candidate nonadrenergic noncholinergic neurotransmitter in the human colon.


Asunto(s)
Colon/inervación , NADPH Deshidrogenasa/análisis , Neuropéptidos/metabolismo , Óxido Nítrico/metabolismo , Anciano , Colon/enzimología , Humanos , Mucosa Intestinal/metabolismo , Persona de Mediana Edad , Plexo Mientérico/química , Plexo Mientérico/citología , Fibras Nerviosas/enzimología , Unión Neuromuscular/fisiología , Neuronas/química
17.
Am J Gastroenterol ; 90(1): 146-7, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7801918

RESUMEN

Complications of colonoscopic polypectomy include perforation, infection, and bleeding. The incidence of bleeding after polypectomy is reported to range from one to seven per 1000 polypectomies. This complication usually occurs within a few days after the standard procedure using bipolar electrocautery. The longest time interval between polypectomy and significant bleeding thus far reported is 14 days. Most cases of postpolypectomy bleeding are easily recognizable and can be effectively treated by colonoscopic electrocauterization. We report here a patient who underwent colonoscopic removal of a flat adenomatous polyp at the cecum and presented 29 days postprocedure with acute onset of severe bleeding from the polypectomy site. A repeat colonoscopy identified this lesion, and cauterization successfully stopped this bleeding.


Asunto(s)
Poliposis Adenomatosa del Colon/cirugía , Colonoscopía/efectos adversos , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/cirugía , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Factores de Tiempo
18.
Gut ; 35(12): 1690-6, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7530228

RESUMEN

The distribution, colocalisation, and interconnections of nitrinergic and peptidergic neurons and nerves in the human oesophagus were examined. Cryosections of surgically resected tissues from eight subjects were studied with indirect immunofluorescence for the presence of 11 neuropeptides and neuron specific enolase. After immunohistochemistry, nitric oxide synthase was shown on the same sections with the beta nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemical reaction. The histochemical findings were verified immunohistochemically on other sections with an antiserum against nitric oxide synthase. Most myenteric neurons (55%) were nitrinergic. Most (96%) received terminations positive for vasoactive intestinal polypeptide (VIP), calcitonin gene related peptide (CGRP) (80%), and galanin (59%). The neuronal somata of 14% also contained VIP, while 10% had galanin. Of the NADPH-diaphorase containing fibers seen in the muscle layers, many had closely associated VIP and galanin, but only rarely CGRP and substance P. Thus, despite abundant representation of both peptidergic and nitrinergic systems in oesophageal smooth muscle, only VIP and galanin colocalised to any significant extent with the nitrinergic elements. These findings provide morphological support for the role of nitric oxide as the non-adrenergic non-cholinergic inhibitory mediator in the human oesophagus and for its possible interactive role with the peptidergic system.


Asunto(s)
Aminoácido Oxidorreductasas/análisis , Esófago/inervación , Neuronas/enzimología , Adulto , Anciano , Péptido Relacionado con Gen de Calcitonina/análisis , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Músculo Liso/inervación , Plexo Mientérico/enzimología , NADPH Deshidrogenasa/análisis , Fibras Nerviosas/enzimología , Óxido Nítrico Sintasa , Fosfopiruvato Hidratasa/análisis , Péptido Intestinal Vasoactivo/análisis
19.
J Clin Gastroenterol ; 19(3): 242-7, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7806838

RESUMEN

The use of herbal and other "natural" health products by healthy and ill people is more common than is appreciated by many health care providers. Since most of these substances are not categorized as medicines, they are exempt from U.S. Government approval processes, and are essentially uncontrolled. In this article we describe a patient who developed painless jaundice, fatigue, and pruritus after taking chaparral tablets, 160 mg/day, for approximately 2 months. Serial liver biopsies and serum chemistries documented severe cholestasis and hepatocellular injury, i.e., a severe cholangiolitic hepatitis. Serum enzyme levels were markedly elevated: alk. phos. to four-fold, alanine aminotransferase and aspartate aminotransferase to 25-fold, total bilirubin to 30-fold, and gamma-glutamyl transpeptidase to 35-fold. Endoscopic retrograde cholangiopancreatography showed smooth, but severely narrowed biliary ducts without sclerosing cholangitis, distal obstruction, tumor, or stenosis. The diagnosis remained in doubt until the publication of two cases of chaparral hepatotoxicity. Because of the similarity of our patient's illness to those cases we concluded that chaparral was almost certainly the cause. Chaparral, also known as creosote or greasewood, is used by some practitioners to treat a diverse group of ailments including ethanol withdrawal. This report should heighten the awareness by primary care physicians and gastroenterologists that any chaparral herbal preparation is a potential hepatotoxin that can lead to serious illness.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Alcoholismo/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Colestasis/inducido químicamente , Creosota/efectos adversos , Biopsia , Enfermedad Hepática Inducida por Sustancias y Drogas/complicaciones , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Colangiopancreatografia Retrógrada Endoscópica , Colestasis/complicaciones , Colestasis/patología , Creosota/administración & dosificación , Femenino , Humanos , Persona de Mediana Edad
20.
Am J Gastroenterol ; 89(10): 1874-9, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7524310

RESUMEN

Achalasia is a disease of the esophagus characterized by incomplete relaxation of the lower esophageal sphincter, resulting in obstruction. Aperistalsis and dilation of the esophageal body occurs later, contributing to the esophageal dysfunction. Gastrointestinal bleeding in achalasia is an infrequent complication usually caused by stasis ulcer, esophageal varices, carcinoma, or pneumatic dilation of the sphincter. We describe here a patient with longstanding achalasia who bled vigorously from a proximal esophageal site that can be identified as arterial bleeding by endoscopy. Subsequent esophageal resection allowed detailed histological and immunohistochemical examination, which revealed a vascular ectasia. This lesion was associated with an unusually rich network of nerve fibers containing calcitonin gene-related peptide. Neuropeptide Y- and substance P-containing fibers were found to be decreased in this lesion as compared with controls. On the other hand vasoactive intestinal peptide- and nitric oxide synthase-containing fibers appeared quantitatively similar to those of controls. Calcitonin gene-related peptide is known to be involved in angiogenesis and may have played a causative role in the development of this lesion. Vascular ectasia may represent a hitherto unreported complication of achalasia.


Asunto(s)
Acalasia del Esófago/patología , Esófago/irrigación sanguínea , Fibras Nerviosas/química , Vasos Sanguíneos/inervación , Vasos Sanguíneos/patología , Péptido Relacionado con Gen de Calcitonina/análisis , Dilatación Patológica , Acalasia del Esófago/complicaciones , Acalasia del Esófago/fisiopatología , Femenino , Técnica del Anticuerpo Fluorescente , Hemorragia Gastrointestinal/etiología , Humanos , Persona de Mediana Edad , Membrana Mucosa/irrigación sanguínea , Neuropéptido Y/análisis , Neuropéptidos/análisis , Sustancia P/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...