RESUMEN
We report a case of symptomatic massive liver echinococcosis due to Echinococcus granulosus, unexpectedly found in a 34 year old woman living in Apulia, Italy. Based on size (max diameter 18 cm), clinical presentation, geographical area, and natural history of echinococcosis, we estimate that the initial infection should have occurred 9-20 yrs before. Presenting symptoms were those of typical mass effect with RUQ pain, pruritus, malaise, and recent weight loss. Abdominal ultrasound diagnosis of probable echinococcal cyst was subsequentely confirmed by positive serology and further detailed by radiological imaging. The cyst was massively occupying subdiaphragmatic liver segments and extending to the omentum and the stomach. The characteristics of the lesion were compatible with the WHO 2003 classification type CE2l, indicating a large active fertile cyst with daughter cysts. The cyst was successfully treated with medical therapy followed by surgery. The prevalence, diagnostic workup, management, and costs of echinococcosis are discussed in this case presentation.
Asunto(s)
Equinococosis Hepática/diagnóstico , Hígado , Adulto , Equinococosis Hepática/parasitología , Equinococosis Hepática/patología , Equinococosis Hepática/terapia , Femenino , Interacciones Huésped-Parásitos , Humanos , Hígado/parasitología , Hígado/patología , Hígado/cirugía , Imagen por Resonancia Magnética , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
In summary, a variety of gastrointestinal processes may occur in the chronically critically ill patient population, usually as consequence of the primary systemic process. The clinical presentation is frequently nonclassic and there often is a substantial delay in diagnosis, resulting in increased morbidity and mortality.
Asunto(s)
Cuidados Críticos , Enfermedades Gastrointestinales/etiología , Enfermedades Pulmonares Obstructivas/terapia , Enfermedades Gastrointestinales/terapia , Humanos , Factores de Riesgo , Estrés Fisiológico/complicacionesRESUMEN
Saccharomyces boulardii is a nonpathogenic yeast that protects against antibiotic-associated diarrhea and recurrent Clostridium difficile colitis. The administration of C. difficile toxoid A by gavage to S. boulardii-fed BALB/c mice caused a 1.8-fold increase in total small intestinal immunoglobulin A levels (P = 0.003) and a 4.4-fold increase in specific intestinal anti-toxin A levels (P < 0.001). Enhancing host intestinal immune responses may be an important mechanism for S. boulardii-mediated protection against diarrheal illnesses.
Asunto(s)
Antitoxinas/biosíntesis , Toxinas Bacterianas/inmunología , Enterotoxinas/inmunología , Inmunoglobulina A Secretora/biosíntesis , Mucosa Intestinal/inmunología , Saccharomyces/fisiología , Animales , Diarrea/prevención & control , Inmunización , Ratones , Ratones Endogámicos BALB CRESUMEN
Clostridium difficile, the major etiologic factor of antibiotic-associated diarrhea and colitis, mediates its effects by releasing two large protein exotoxins, toxins A and B. A major toxin effect is related to the disassembly of actin microfilaments, leading to impairment of tight junctions in human colonocytes. The mechanism of actin disaggregation involves monoglucosylation of the signaling proteins Rho A, Rac, and Cdc 42, which control stress fiber formation directly by toxins A and B. An important aspect of C. difficile infection is the acute necroinflammatory changes seen in patients with pseudomembranous colitis. The early mechanism of toxin-mediated inflammation involves toxin effects on cellular mitochondria, release of reactive oxygen species, and activation of mitogen-activated protein kinases and the transcription factor nuclear factor-kappaB. Injection of toxin A into animal intestine triggers secretion of fluid and intestinal inflammation characterized by epithelial cell destruction and neutrophil activation. A critical feature of C. difficile enterotoxicity is communication between enterocytes and lamina propria nerves, macrophages, and mast cells mediated via release of neuropeptides and proinflammatory cytokines.
Asunto(s)
Toxinas Bacterianas/farmacología , Clostridioides difficile , Intestinos/efectos de los fármacos , Proteínas de Fase Aguda/metabolismo , Animales , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Citoesqueleto/efectos de los fármacos , Enterotoxinas/farmacología , Glicosilación , Humanos , Mediadores de Inflamación/farmacología , Receptores de Superficie Celular/metabolismoAsunto(s)
Jugo Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Moco/fisiología , Animales , PermeabilidadAsunto(s)
Proteínas Bacterianas , Clostridioides difficile/patogenicidad , Infecciones por Clostridium/microbiología , Colitis/etiología , Diarrea/etiología , Adulto , Toxinas Bacterianas/efectos adversos , Portador Sano/microbiología , Niño , Preescolar , Clostridioides difficile/aislamiento & purificación , Clostridioides difficile/fisiología , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/patología , Colitis/microbiología , Colitis/patología , Colon/microbiología , Colon/patología , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Diarrea/microbiología , Diarrea/patología , Susceptibilidad a Enfermedades , Enterocolitis Seudomembranosa/etiología , Enterocolitis Seudomembranosa/microbiología , Enterocolitis Seudomembranosa/patología , Enterotoxinas/efectos adversos , Humanos , Lactante , Recién Nacido , Enfermedades Inflamatorias del Intestino/complicaciones , Perforación Intestinal/etiología , Recurrencia , Factores de Riesgo , Úlcera , Virulencia , Proteínas de Unión al GTP rho/antagonistas & inhibidores , Proteínas de Unión al GTP rho/fisiologíaRESUMEN
BACKGROUND & AIMS: The mechanism by which Clostridium difficile toxin A causes actin depolymerization and cell rounding involves toxin internalization and subsequent monoglucosylation of the Rho family of proteins. This study explored toxin internalization and effects on mitochondrial function before cell rounding. METHODS: Chinese hamster ovary (CHO) cells were exposed to toxin A, and mitochondrial localization was assayed by confocal microscopy. Mitochondrial function was measured by adenosine triphosphate (ATP) concentration, mitochondrial permeability, and leakage of cytochrome c. RESULTS: Confocal microscopy showed toxin A colocalization with the mitochondrial protein GRP 75 at 5 minutes after toxin exposure. Between 5 and 15 minutes, toxin A caused an 80% diminution in cellular ATP levels; cell rounding and Rho glucosylation commenced between 15 and 30 minutes. Toxin A also resulted in reduction of mitochondrial membrane potential and a 2-3-fold increase in reactive oxygen radicals. Preincubation of CHO cells with the antioxidants butylated hydroxyanisole or butylated hydroxytoluene blocked the toxin A-induced increase in oxygen radicals and diminished cell rounding. Western blot analysis of toxin A-exposed isolated mitochondria showed a direct effect of toxin A on leakage of cytochrome c. CONCLUSIONS: The results show that extensive mitochondrial damage occurs within 15 minutes in CHO cells exposed to toxin A. Diminished ATP concentrations and increased oxygen radicals are likely to contribute to cytotoxicity from this bacterial toxin.
Asunto(s)
Toxinas Bacterianas/farmacología , Enterotoxinas/farmacología , Mitocondrias/efectos de los fármacos , Adenosina Trifosfato/antagonistas & inhibidores , Animales , Toxinas Bacterianas/metabolismo , Células CHO , Membrana Celular/metabolismo , Cricetinae , Grupo Citocromo c/metabolismo , Enterotoxinas/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Microscopía Electrónica , Mitocondrias/metabolismo , Mitocondrias/fisiología , Mitocondrias/ultraestructura , Especies Reactivas de Oxígeno/metabolismo , Distribución TisularAsunto(s)
Enfermedades Gastrointestinales/tratamiento farmacológico , Infecciones/tratamiento farmacológico , Animales , Infecciones Bacterianas/tratamiento farmacológico , Esofagitis/tratamiento farmacológico , Esofagitis/microbiología , Esofagitis/parasitología , Esofagitis/virología , Humanos , Enfermedades Parasitarias/tratamiento farmacológico , Virosis/tratamiento farmacológicoRESUMEN
Clostridium difficile toxin A causes acute neutrophil infiltration and intestinal mucosal injury. In cultured cells, toxin A inactivates Rho proteins by monoglucosylation. In monocytes, toxin A induces IL-8 production and necrosis by unknown mechanisms. We investigated the role of mitogen-activated protein (MAP) kinases in these events. In THP-1 monocytic cells, toxin A activated the 3 main MAP kinase cascades within 1 to 2 minutes. Activation of p38 was sustained, whereas stimulation of extracellular signal-regulated kinases and c-Jun NH(2)-terminal kinase was transient. Rho glucosylation became evident after 15 minutes. IL-8 gene expression was reduced by 70% by the MEK inhibitor PD98059 and abrogated by the p38 inhibitor SB203580 or by overexpression of dominant-negative mutants of the p38-activating kinases MKK3 and MKK6. SB203580 also blocked monocyte necrosis and IL-1beta release caused by toxin A but not by other toxins. Finally, in mouse ileum, SB203580 prevented toxin A-induced neutrophil recruitment by 92% and villous destruction by 90%. Thus, in monocytes exposed to toxin A, MAP kinase activation appears to precede Rho glucosylation and is required for IL-8 transcription and cell necrosis. p38 MAP kinase also mediates intestinal inflammation and mucosal damage induced by toxin A.
Asunto(s)
Toxinas Bacterianas/farmacología , Clostridioides difficile/inmunología , Enteritis/inmunología , Enterotoxinas/farmacología , Interleucina-8/biosíntesis , Sistema de Señalización de MAP Quinasas , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Monocitos/inmunología , Animales , Toxinas Bacterianas/metabolismo , Línea Celular , Clostridioides difficile/metabolismo , Enteritis/enzimología , Enteritis/microbiología , Enterocolitis Seudomembranosa/enzimología , Enterocolitis Seudomembranosa/inmunología , Enterocolitis Seudomembranosa/microbiología , Enterotoxinas/metabolismo , Activación Enzimática , Regulación de la Expresión Génica/efectos de los fármacos , Glicosilación , Interleucina-8/genética , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos , Proteína Quinasa 8 Activada por Mitógenos , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/inmunología , Monocitos/metabolismo , Monocitos/patología , Infiltración Neutrófila/inmunología , Neutrófilos/inmunología , Proteínas Quinasas p38 Activadas por Mitógenos , Proteínas de Unión al GTP rho/inmunología , Proteínas de Unión al GTP rho/metabolismoAsunto(s)
Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico , Procesamiento de Imagen Asistido por Computador , Tamizaje Masivo/métodos , Tomografía Computarizada por Rayos X/métodos , Colonoscopía/economía , Colonoscopía/normas , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/economía , Masculino , Tamizaje Masivo/economía , Tamizaje Masivo/normas , Persona de Mediana Edad , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/economíaRESUMEN
In order to sequence the cysteine-rich regions of pig gastric mucin (PGM), we used our previously identified pig gastric mucin clone PGM-2A to screen a pig stomach cDNA library and perform rapid amplification of cDNA ends to obtain two cysteine-rich clones, PGM-2X and PGM-Z13. PGM-2X has 1071 base pairs (bp) encoding 357 amino acids containing five serine-threonine-rich 16 amino acid tandem repeats, downstream from a cysteine-rich region similar to human and mouse MUC5AC. PGM-Z13 encodes the complete 3'-terminus of PGM and is composed of 3336 bp with a 2964 bp open reading frame encoding 988 amino acids with four serine-threonine-rich tandem repeats upstream from a cysteine-rich region similar to the carboxyl terminal regions of human and rat MUC5AC and human MUC5B. This region is homologous to von Willebrand factor C and D domains involved in acid induced polymerization, and to the carboxyl terminal cystine-knot domain of various mucins, TGF-beta, vWF and norrin, which is involved in dimerization. These newly sequenced cysteine-rich regions of pig gastric mucin may be critical for its gelation and for its observed increased viscosity induced by low pH.
Asunto(s)
Cisteína/análisis , Cistina/análisis , Mucinas Gástricas/química , Factor de von Willebrand/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cistina/genética , ADN Complementario/química , Epitelio/química , Mucosa Gástrica/química , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Alineación de Secuencia , Serina/análisis , Porcinos , Secuencias Repetidas en Tándem , Treonina/análisis , Factor de von Willebrand/genéticaRESUMEN
BACKGROUND: Strains of Bacteroides fragilis producing a 20 kDa protein toxin (B fragilis toxin (BFT) or fragilysin) are associated with diarrhoea in animals and humans. Although in vitro results indicate that BFT damages intestinal epithelial cells in culture, the effects of BFT on native human colon are not known. AIMS: To examine the electrophysiological and morphological effects of purified BFT-2 on human colonic mucosa in vitro. METHODS: For resistance (R) measurements, colonic mucosa mounted in Ussing chambers was exposed to luminal or serosal BFT-2 (1.25-10 nM) and after four hours morphological damage was measured on haematoxylin and eosin stained sections using morphometry. F actin distribution was assessed using confocal microscopy. RESULTS: Serosal BFT-2 for four hours was four-, two-, seven-, and threefold more potent than luminal BFT-2 in decreasing resistance, increasing epithelial 3H-mannitol permeability, and damaging crypt and surface colonocytes, respectively (p<0.05). Confocal microscopy showed reduced colonocyte F actin staining intensity after exposure to BFT-2. CONCLUSIONS: BFT-2 increases human colonic permeability and damages human colonic epithelial cells in vitro. These effects may be important in the development of diarrhoea and intestinal inflammation caused by B fragilis in vivo.
Asunto(s)
Toxinas Bacterianas/farmacología , Bacteroides fragilis , Colon/efectos de los fármacos , Mucosa Intestinal/efectos de los fármacos , Actinas/metabolismo , Colon/patología , Colon/fisiopatología , Técnicas de Cultivo , Electrofisiología , Humanos , Mucosa Intestinal/patología , Mucosa Intestinal/fisiopatología , Manitol/farmacocinética , Microscopía Confocal , Microscopía Fluorescente , PermeabilidadRESUMEN
We present dynamic light scattering (DLS) and hydrophobic dye-binding data in an effort to elucidate a molecular mechanism for the ability of gastric mucin to form a gel at low pH, which is crucial to the barrier function of gastric mucus. DLS measurements of dilute mucin solutions were not indicative of intermolecular association, yet there was a steady fall in the measured diffusion coefficient with decreasing pH, suggesting an apparent increase in size. Taken together with the observed rise in depolarized scattering ratio with decreasing pH, these results suggest that gastric mucin undergoes a conformational change from a random coil at pH >/= 4 to an anisotropic, extended conformation at pH < 4. The increased binding of mucin to hydrophobic fluorescent with decreasing pH indicates that the change to an extended conformation is accompanied by exposure of hydrophobic binding sites. In concentrated mucin solutions, the structure factor S(q, t) derived from DLS measurements changed from a stretched exponential decay at pH 7 to a power-law decay at pH 2, which is characteristic of a sol-gel transition. We propose that the conformational change facilitates cross-links among mucin macromolecules through hydrophobic interactions at low pH, which in turn leads to a sol-gel transition when the mucin solution is sufficiently concentrated.
Asunto(s)
Mucinas Gástricas/química , Animales , Sitios de Unión , Fenómenos Biofísicos , Biofisica , Bovinos , Difusión , Colorantes Fluorescentes , Vesícula Biliar/química , Geles , Concentración de Iones de Hidrógeno , Luz , Sustancias Macromoleculares , Modelos Moleculares , Mucinas/química , Conformación Proteica , Dispersión de Radiación , Soluciones , Electricidad Estática , PorcinosRESUMEN
Reactive oxygen metabolites (ROMs) contribute to the pathophysiology of intestinal inflammation. Our aim was to ascertain the involvement of ROMs in experimental ileitis in rats produced by toxin A of Clostridium difficile. Intraluminal toxin A caused a significant increase in hydroxyl radical and hydrogen peroxide production by ileal microsomes starting 1 h following toxin exposure and peaking at 2-3 h, and this was inhibited by pretreatment with DMSO, a ROM scavenger, or superoxide dismutase (SOD), which inactivates ROMs. In contrast, mucosal xanthine oxidase increased only slightly after toxin A exposure, and allopurinol, an inhibitor of xanthine oxidase, had no effect on toxin A-associated intestinal responses. Induction of neutropenia resulted in reduction of toxin-mediated free radical formation, fluid secretion, and permeability. The enterotoxic effects of C. difficile toxin A were associated with increased ROM release in ileal tissues, and the ROM inhibitors DMSO and SOD inhibited these effects. This suggests that ROMs released during toxin A enteritis are released primarily from neutrophils invading the inflamed bowel segment.
Asunto(s)
Toxinas Bacterianas , Enteritis/inducido químicamente , Enterotoxinas , Especies Reactivas de Oxígeno/fisiología , Animales , Dimetilsulfóxido/farmacología , Enterotoxinas/antagonistas & inhibidores , Depuradores de Radicales Libres/farmacología , Íleon/efectos de los fármacos , Íleon/enzimología , Técnicas In Vitro , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/enzimología , Masculino , Neutrófilos/fisiología , Peroxidasa/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/farmacología , Xantina Oxidasa/metabolismoRESUMEN
BACKGROUND: Bovine immunoglobulin concentrate (BIC)-Clostridium difficile is prepared from the colostrum of cows immunised against C difficile toxins and contains high concentrations of neutralising IgG antitoxin. AIMS: To determine the proportion of BIC-C difficile which survives passage through the human stomach and small intestine. METHODS: Six volunteers with an end ileostomy took 5 g of BIC-C difficile containing 2.1 g of bovine IgG on four occasions: alone, with an antacid, during treatment with omeprazole, and within enteric coated capsules. RESULTS: When BIC-C difficile was taken alone, a mean (SEM) of 1033 (232) mg of bovine IgG was recovered in the ileal fluid representing 49% of the total ingested dose. Bovine IgG recovery was not significantly increased by antacid (636 (129) mg) or omeprazole (1052 (268) mg). The enteric capsules frequently remained intact or only partially opened in the ileal effluent and free bovine IgG levels were low in this treatment group (89 (101) mg). Bovine IgG recovery was higher in volunteers with shorter (less than two hours) mouth to ileum transit times (68% versus 36%, p<0. 05). Specific bovine IgG against C difficile toxin A was detected in ileal fluid following oral BIC. Toxin neutralising activity was also present and correlated closely with bovine IgG levels (r=0.95, p<0. 001). CONCLUSION: BIC-C difficile resists digestion in the human upper gastrointestinal tract and specific anti-C difficile toxin A binding and neutralising activity was retained. Passive oral immunotherapy with anti-C difficile BIC may be a useful non-antibiotic approach to the prevention and treatment of C difficile antibiotic associated diarrhoea and colitis.
Asunto(s)
Anticuerpos Antibacterianos/metabolismo , Antitoxinas/metabolismo , Clostridioides difficile/inmunología , Sistema Digestivo/metabolismo , Inmunoglobulina G/metabolismo , Administración Oral , Adulto , Anciano , Animales , Toxinas Bacterianas/inmunología , Toxinas Bacterianas/metabolismo , Bovinos , Calostro/inmunología , Enterotoxinas/inmunología , Enterotoxinas/metabolismo , Femenino , Mucosa Gástrica/metabolismo , Tránsito Gastrointestinal , Humanos , Íleon/metabolismo , Masculino , Persona de Mediana EdadRESUMEN
Saccharomyces boulardii is a nonpathogenic yeast used in the treatment of Clostridium difficile diarrhea and colitis. We have reported that S. boulardii inhibits C. difficile toxin A enteritis in rats by releasing a 54-kDa protease which digests the toxin A molecule and its brush border membrane (BBM) receptor (I. Castagliuolo, J. T. LaMont, S. T. Nikulasson, and C. Pothoulakis, Infect. Immun. 64:5225-5232, 1996). The aim of this study was to further evaluate the role of S. boulardii protease in preventing C. difficile toxin A enteritis in rat ileum and determine whether it protects human colonic mucosa from C. difficile toxins. A polyclonal rabbit antiserum raised against purified S. boulardii serine protease inhibited by 73% the proteolytic activity present in S. boulardii conditioned medium in vitro. The anti-protease immunoglobulin G (IgG) prevented the action of S. boulardii on toxin A-induced intestinal secretion and mucosal permeability to [3H]mannitol in rat ileal loops, while control rabbit IgG had no effect. The anti-protease IgG also prevented the effects of S. boulardii protease on digestion of toxins A and B and on binding of [3H]toxin A and [3H]toxin B to purified human colonic BBM. Purified S. boulardii protease reversed toxin A- and toxin B-induced inhibition of protein synthesis in human colonic (HT-29) cells. Furthermore, toxin A- and B-induced drops in transepithelial resistance in human colonic mucosa mounted in Ussing chambers were reversed by 60 and 68%, respectively, by preexposing the toxins to S. boulardii protease. We conclude that the protective effects of S. boulardii on C. difficile-induced inflammatory diarrhea in humans are due, at least in part, to proteolytic digestion of toxin A and B molecules by a secreted protease.
Asunto(s)
Proteínas Bacterianas , Toxinas Bacterianas/toxicidad , Clostridioides difficile/inmunología , Colon/microbiología , Enterotoxinas/toxicidad , Mucosa Intestinal/microbiología , Metaloendopeptidasas/farmacología , Saccharomyces/enzimología , Animales , Antitoxinas/farmacología , Toxinas Bacterianas/metabolismo , Sitios de Unión/inmunología , Colon/enzimología , Colon/inmunología , Medios de Cultivo Condicionados , Citotoxinas/metabolismo , Citotoxinas/toxicidad , Enterocolitis Seudomembranosa/inmunología , Enterocolitis Seudomembranosa/microbiología , Enterocolitis Seudomembranosa/prevención & control , Enterotoxinas/metabolismo , Células HT29 , Humanos , Hidrólisis , Inmunoglobulina G/farmacología , Mucosa Intestinal/enzimología , Mucosa Intestinal/inmunología , Masculino , Metaloendopeptidasas/inmunología , Microvellosidades/enzimología , Microvellosidades/inmunología , Microvellosidades/metabolismo , Inhibidores de la Síntesis de la Proteína/inmunología , Ratas , Ratas Wistar , Saccharomyces/inmunologíaRESUMEN
Clostridium difficile infection has become in recent years an important nosocomial threat. Prevention of the spread of C. difficile infection among long term hospitalized patients is a major challenge since C. difficile spores can persist indefinitely in the hospital environment. Following antibiotic therapy that disrupts the normal bacterial flora of the colon, C. difficile can colonize the large intestine. The bacteria releases two large protein toxins that bind to colonocytes and mediate an acute inflammatory diarrhea characterized by an abundant exudate rich in neutrophils and proteins that in some cases can form the typical "pseudomembrane". C. difficile infection shows a spectrum of severity from asymptomatic carrier to fulminant acute pseudomembraneous colitis. The gold standard for the laboratory diagnosis of C. difficile infection is the stool-cytotoxin test, however recently developed immunoassays represent a good alternative. The treatment of C. difficile infection is based on the severity of the clinical picture. In patients with mild diarrhea discontinuation of the causing antibiotic can be an adequate therapeutic approach, whereas patients with more severe symptoms require antibiotic therapy or, in the most severe infections, even colectomy.