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1.
Z Gastroenterol ; 53(12): 1447-95, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26666283

RESUMEN

Chronic pancreatitis is a disease of the pancreas in which recurrent inflammatory episodes result in replacement of pancreatic parenchyma by fibrous connective tissue. This fibrotic reorganization of the pancreas leads to a progressive exocrine and endocrine pancreatic insufficiency. In addition, characteristic complications arise, such as pseudocysts, pancreatic duct obstructions, duodenal obstruction, vascular complications, obstruction of the bile ducts, malnutrition and pain syndrome. Pain presents as the main symptom of patients with chronic pancreatitis. Chronic pancreatitis is a risk factor for pancreatic carcinoma. Chronic pancreatitis significantly reduces the quality of life and the life expectancy of affected patients. These guidelines were researched and compiled by 74 representatives from 11 learned societies and their intention is to serve evidence-based professional training as well as continuing education. On this basis they shall improve the medical care of affected patients in both the inpatient and outpatient sector. Chronic pancreatitis requires an adequate diagnostic workup and systematic management, given its severity, frequency, chronicity, and negative impact on the quality of life and life expectancy.


Asunto(s)
Endoscopía Gastrointestinal/normas , Pancreatectomía/normas , Pruebas de Función Pancreática/normas , Pancreatitis/diagnóstico , Pancreatitis/terapia , Guías de Práctica Clínica como Asunto , Enfermedad Crónica , Alemania , Humanos , Estados Unidos
2.
Z Gastroenterol ; 53(2): 108-14, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25668712

RESUMEN

BACKGROUND: IgA- and IgG-antibodies against deamidated gliadin peptides (DGP) specifically bind the disease-inducing antigen and might be superior to transglutaminase type 2 (TG2) IgA in monitoring patients on a gluten-free diet (GFD). The aim of this study was to compare the performance of DGP-IgG and DGP-IgA with TG2-IgA of four manufacturers in pediatric celiac patients at diagnosis and during follow-up under a GFD. PATIENTS AND METHODS: In total 411 sera of 91 IgA competent children with biopsy proven celiac disease were analyzed at diagnosis and during follow-up on a GFD. Ninety-eight children with normal duodenal histology served as controls. The tests (TheBindingSite, Euroimmun, Phadia, part of Thermo Fisher Scientific, INOVA) for detection of TG2-IgA, DGP-IgG and DGP-IgA were used according to the manufacturers' instructions. RESULTS: Sensitivity to diagnose CD was high for TG2-IgA (100 %) and DGP-IgG (90 - 100 %), but lower for DGP-IgA (67 - 86 %). Specificity was high for all tests (97 - 100 %). The frequency of TG2-IgA titers > 10â€Š× upper limit of normal at diagnosis ranged from 47 - 90 %. Under a GFD DGP-IgA became negative more rapidly than DGP-IgG and TG2-IgA. Non-adherence to GFD was best indicated by positive TG2-IgA. CONCLUSIONS: Combined testing for TG2-IgA and DGP-IgG does not increase the detection rate of CD in IgA competent children compared to TG2-IgA only. There are significant differences with respect to proportions of celiac children with titers > 10â€Š× ULN between the manufacturers. This calls for harmonization of tests. TG2-IgA showed the highest titer rise with non-adherence to the GFD, independent of the manufacturer.


Asunto(s)
Enfermedad Celíaca/diagnóstico , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Anticuerpos/inmunología , Niño , Preescolar , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
3.
Aliment Pharmacol Ther ; 39(12): 1398-407, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24779671

RESUMEN

BACKGROUND: Exclusive enteral nutrition (EEN) induces remission and mucosal healing in children with active Crohn's disease (CD). AIM: To compare short- and long-term outcomes of the first vs. second courses of EEN, and to identify predictors of sustained remission. METHODS: Retrospective single centre analysis of all patients with CD (6-18 years) treated with EEN over 7.5 years. Patients were excluded if exposed to anti-TNFα or corticosteroids 3 months prior to EEN. Data included disease phenotype, activity, NOD2 genotype, laboratory indices and anthropometrics. Remission and relapse were defined by mathematically weighted Paediatric Crohn's Disease Activity Index (wPCDAI) with 1-year follow-up. RESULTS: Of 94 patients treated with EEN, 52 fulfilled inclusion criteria (31 male, mean age 13.2 years). Azathioprine was started within the first month in 33/52 patients; 26/52 received a second EEN course. First compared to second EEN revealed higher wPCDAI at start (59 vs. 40, P < 0.0001), tended to higher remission rates after 3 months (92% vs. 77%, n.s.), but showed comparable 1-year relapse rates (67% vs. 70%, median time 231 vs. 145 days, n.s.). Disease activity, weight gain and inflammatory markers showed better improvement with first EEN. Faecal calprotectin >200 µg/g during EEN was associated with shorter remission (median time 157 vs. 287 days, n.s.). Certain NOD2 genotypes were related to higher relapse rates (92% R702W or G908R vs. 50% 1007fs vs. 60% wild-type, P < 0.01). CONCLUSIONS: Exclusive enteral nutrition induces remission in active Crohn's disease, but efficacy tends to decrease with the second course. Despite early azathioprine use, 1-year relapse rates are high, but may be related to NOD2 genotype.


Asunto(s)
Enfermedad de Crohn/terapia , Nutrición Enteral , Adolescente , Azatioprina/uso terapéutico , Niño , Enfermedad de Crohn/genética , Femenino , Genotipo , Humanos , Inmunosupresores/uso terapéutico , Masculino , Proteína Adaptadora de Señalización NOD2/genética , Recurrencia , Inducción de Remisión , Estudios Retrospectivos , Resultado del Tratamiento
4.
Z Gastroenterol ; 51(10): 1184-7, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24122380

RESUMEN

Cholesteryl ester storage disease (CESD) is a rare, autosomal recessively inherited disorder resulting from deficient activity of lysosomal acid lipase (LAL). LAL is the key enzyme hydrolyzing cholesteryl esters and triglycerides stored in lysosomes after LDL receptor-mediated endocytosis. Mutations within the LIPA gene locus on chromosome 10q23.2-q23.3 may result either in the always fatal Wolman disease, where no LAL activity is found, or in the more benign disorder CESD with a reduced enzymatic activity, leading to massive accumulation of cholesteryl esters and triglycerides in many body tissues. CESD affects mostly the liver, the spectrum is ranging from isolated hepatomegaly to liver cirrhosis. Chronic diarrhea has been reported in some pediatric cases, while calcifications of the adrenal glands, the hallmark of Wolman disease, are rarely observed. Hypercholesterolemia and premature atherosclerosis are other typical disease manifestations. Hepatomegaly as a key finding has been reported in all 71 pediatric patients and in 134 of 135 adult cases in the literature. We present a 13-year-old boy with mildly elevated liver enzymes in the absence of hepatomegaly, finally diagnosed with CESD. Under pravastatine treatment, the patient has normal laboratory findings and is clinically unremarkable since 5 years of follow-up. To our knowledge, this is the first pediatric case of genetically and biopsy confirmed CESD without hepatomegaly, suggesting that this diagnosis can be easily missed. It further raises the question about the natural course and the therapy required for this oligosymptomatic form.


Asunto(s)
Enfermedad de Acumulación de Colesterol Éster/diagnóstico , Enfermedad de Acumulación de Colesterol Éster/genética , Errores Diagnósticos/prevención & control , Predisposición Genética a la Enfermedad/genética , Esterol Esterasa/genética , Adolescente , Diagnóstico Diferencial , Reacciones Falso Negativas , Humanos , Masculino , Evaluación de Síntomas/métodos
6.
Gut ; 58(11): 1467-72, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19625281

RESUMEN

OBJECTIVE: To systematically evaluate the feasibility and methodology to carry out wireless capsule endoscopy (WCE) in children <8 years to define small intestinal pathology. DESIGN: Prospective European multicentre study with negative prior investigation. PATIENTS AND INTERVENTIONS: 83 children aged 1.5-7.9 years were recruited. Initially, all were offered "swallowing" (Group 1) for capsule introduction. If this failed endoscopic placement (Group 2) was used and the Roth net, Advance or custom-made introducers were compared. OUTCOME MEASURES: Primary endpoint: to determine pathology; secondary endpoint: comparison of capsule introduction methods. RESULTS: Capsule introduction: 20 (24%) children aged 4.0-7.9 years (mean, 6.9 years; 14 male) comprising Group 1 were older (p<0.025) than 63 (76%) aged 1.5-7.9 years (mean, 5.25 years; 30 male) forming Group 2. COMPLICATIONS: Roth net mucosal trauma in 50%; no others occurred. The available recording apparatus was inappropriate for those <3 years. INDICATIONS: gastrointestinal bleeding: n = 30 (16 positive findings: four ulcerative jejunitis, four polyps, two angiodysplasia, two blue rubber blebs, two Meckel's diverticula, one anastomotic ulcer, one reduplication); suspected Crohn's disease: n = 20 (11 had Crohn's disease); abdominal pain: n = 12 (six positive findings: three Crohn's disease, two lymphonodular hyperplasia, one blue rubber bleb); protein loss: n = 9 (four lymphangectasia); malabsorption: n = 12 (seven positive findings: six enteropathy, one ascaris). No abnormalities overall: 45%. CONCLUSION: WCE is feasible and safe down to the age of 1.5 years. 20 children >4 years swallowed the capsule. The Advance introducer proved superior for endoscopic placement. The pathologies encountered showed age specificity and, unlike in adolescents, obscure gastrointestinal bleeding was the commonest indication.


Asunto(s)
Angiodisplasia/diagnóstico , Endoscopía Capsular , Enfermedad de Crohn/diagnóstico , Divertículo Ileal/diagnóstico , Dolor Abdominal/etiología , Endoscopía Capsular/efectos adversos , Endoscopía Capsular/métodos , Niño , Preescolar , Europa (Continente) , Estudios de Factibilidad , Femenino , Hemorragia Gastrointestinal/etiología , Humanos , Lactante , Síndromes de Malabsorción/etiología , Masculino , Enteropatías Perdedoras de Proteínas/diagnóstico , Resultado del Tratamiento
7.
Clin Nephrol ; 61(5): 324-36, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15182127

RESUMEN

BACKGROUND/AIMS: Advanced glycated end products (AGE) are endogenous proteins that have formed covalent complexes with sugars by a nonenzymatic process. Being proinflammatory molecules, AGE are thought to contribute to chronic systemic and local inflammatory processes associated with pathological changes in various diseases. In patients with end-stage renal disease, AGE are believed to play a role in the progression of atherosclerosis and worsening of renal failure. In patients receiving hemodialysis, AGE are thought to contribute to the inflammatory components of the therapy, particularly in diabetic patients. METHODS: In the present study, AGE were produced using 5% human serum albumin (HSA) and 50% glucose, both used for intravenous infusion into humans and both released after strict control for endotoxin content. The presence of AGE formed by HSA and glucose was confirmed using 2 independent assays. The inflammatory properties of these AGE were assessed using synthesis and release of the proinflammatory cytokines interleukin-1 (IL-1), tumor necrosis factor (TNF) and IL-8, a chemokine. RESULTS: Alone, AGE did not induce these cytokines from peripheral blood mononuclear cells (PBMC) obtained from 14 healthy human donors. However, in the presence of 1 or 10 ng/ml of endotoxin, AGE augmented the production of IL-1 and TNF above that induced by endotoxin alone. Although the amount of augmentation of LPS-induced cytokines by AGE varied between the blood donors, the response was consistently observed and reached statistical significance. The augmentation of cytokine production was confirmed using AGE prepared with different lots of HSA and glucose. CONCLUSION: These results demonstrate that in the strict absence ofendotoxins, AGE are formed that do not stimulate cytokine production from PBMC of healthy donors, however, AGE significantly augment the synthesis and release of proinflammatory cytokine in the presence of low concentrations of endotoxins. The data suggest that renal replacement therapies should consider the role of microbial products in potentiating the biological consequences of naturally formed AGE and their potential to contribute to systemic and local inflammation in renal replacement therapies. Therefore, although the formation of AGE is unavoidable, excluding microbial products during renal replacement therapy should reduce the pathological consequences of AGE.


Asunto(s)
Productos Finales de Glicación Avanzada/farmacología , Interleucina-1/biosíntesis , Interleucina-8/biosíntesis , Lipopolisacáridos/farmacología , Factor de Necrosis Tumoral alfa/biosíntesis , Adulto , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad
8.
Eur Respir J ; 19(6): 1015-9, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12108850

RESUMEN

Exhaled nitric oxide (eNO) is elevated in several inflammatory airway diseases and is significantly reduced by anti-inflammatory treatment with inhaled steroids. The aim of this randomized, open clinical trial was to evaluate eNO in relation to conventional lung function parameters at rest and after exercise during sequential changes of inhaled steroids in children with persistent asthma. The study consisted of a 4 week run-in period, a 4 week washout phase and a randomized treatment period during which only one group was treated again with inhaled budesonide. After run-in, eNO was reduced to normal values, and rose again during washout. In the patients randomized to steroid treatment, eNO was again decreased, whereas it remained unchanged in the untreated patients. Forced expiratory volume in one second and forced vital capacity at rest and after exercise improved significantly after run-in, but showed no difference after randomization. However there was a strong correlation of eNO with patient compliance. Exhaled nitric oxide was able to differentiate between children briefly treated with or without steroids, the conventional lung-function variables however could not. In practice exhaled nitric oxide may thus be a valuable parameter to monitor adherence to steroids, but less suitable to describe physiologically relevant impairments of lung function.


Asunto(s)
Antiinflamatorios/administración & dosificación , Asma/tratamiento farmacológico , Asma/metabolismo , Budesonida/administración & dosificación , Óxido Nítrico/metabolismo , Adolescente , Asma/diagnóstico , Biomarcadores , Niño , Ejercicio Físico , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Rendimiento Pulmonar/efectos de los fármacos , Masculino , Descanso , Capacidad Vital/efectos de los fármacos
9.
Pediatr Surg Int ; 17(5-6): 351-5, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11527163

RESUMEN

Within a 3-year period we observed six children, aged 3 months to 4 years, with dumping syndrome (DS) following Nissen fundoplication. Five were neurologically normal and one was slightly mentally retarded. Symptoms included postprandial tachycardia, diaphoresis, lethargy, severe retching, meteorism or gas-bloat syndrome, watery diarrhea, refusal to eat with failure to thrive, and developmental delay. Results of an oral glucose tolerance test did not correlate with the severity of symptoms. In one child severe retching led to recurrent paraesophageal gastric herniation, necessitating two reoperations and a gastrostomy. A lack of meal stimulated pancreatic polypeptide release in this patient indicated vagal damage. Initially five of the six children needed continuous intragastric feeding until bolus application of a carbohydrate-modified diet was tolerated. We conclude that the diagnosis of DS is often delayed in spite of characteristic clinical signs. Intensive postoperative follow-up after antireflux surgery should be mandatory in children.


Asunto(s)
Síndrome de Vaciamiento Rápido , Fundoplicación , Preescolar , Síndrome de Vaciamiento Rápido/complicaciones , Síndrome de Vaciamiento Rápido/diagnóstico , Síndrome de Vaciamiento Rápido/dietoterapia , Síndrome de Vaciamiento Rápido/etiología , Femenino , Humanos , Hipoglucemia/diagnóstico , Hipoglucemia/etiología , Lactante , Masculino , Polipéptido Pancreático/sangre , Cuidados Posoperatorios , Reoperación
10.
Eur J Med Res ; 6(1): 33-8, 2001 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-11313189

RESUMEN

The surfactant proteins SP-D and SP-A are collectins and central components of the innate immune system of the peripheral lungs. They bind to carbohydrates on microorganisms and promote their removal. In the larger airways their role and concentrations are not yet known. Sputum may thus potentially be useful to characterize the collectins in this compartment. Induced sputum was obtained from healthy adults and spontaneous sputum from patients with cystic fibrosis. ELISA and carbohydrate binding assays were used to quantify the amount and functional capacity of the collectins in plugs or sol-fractions, prepared by centrifugation of the plugs. SP-D and SP-A were detectable in only about 50% of the sputum plugs. Varying the salt, detergent and calcium conditions of the assay did not improve the results. In samples with reproducibly detectable SP-D or SP-A, their carbohydrate binding capacity was zero. Sputum sol fraction and LPS inhibited the binding of the collectins to carbohydrate in the presence of calcium. Whereas SP-D and SP-A are abundant in the peripheral lung, their presence in sputum derived from the larger airways is variable and their carbohydrate binding capacity is lost.


Asunto(s)
Fibrosis Quística/metabolismo , Glicoproteínas/análisis , Pulmón/química , Proteolípidos/análisis , Surfactantes Pulmonares/análisis , Esputo/química , Adolescente , Adulto , Metabolismo de los Hidratos de Carbono , Quelantes , Niño , Detergentes , Ácido Edético , Ensayo de Inmunoadsorción Enzimática , Humanos , Lipopolisacáridos , Pulmón/fisiología , Persona de Mediana Edad , Octoxinol , Proteína A Asociada a Surfactante Pulmonar , Proteína D Asociada a Surfactante Pulmonar , Proteínas Asociadas a Surfactante Pulmonar , Solubilidad
11.
Eur Respir J ; 10(9): 1989-94, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9311490

RESUMEN

Cystic fibrosis (CF) is a lethal disorder which results in excessive airway secretions and in chronic inflammation of the airways. In vitro and in vivo studies have shown that a lack of surfactant results in the closure of the small airways. In this pilot study, we aimed to determine whether surfactant administered by aerosol might improve lung function on a short-term basis in patients with CF. In a randomized, crossover double-blind pilot study, 120 mg of a lipid-extracted bovine surfactant (Alveofact) or placebo was aerosolized to five young adult patients with CF over a period of 30 min for five consecutive days. The sample size had the power of 90% to detect an increase in forced expiratory volume in one second (FEV1) of 15% (p < 0.05). Jet nebulization of surfactant produced particles of which more than 75% were the respirable range (< 5 microns). The inhalations were well tolerated. No changes in serum antibody titres against the surfactant proteins-B and -C (SP-B/SP-C) were observed. No differences in FEV1 and forced vital capacity were found before, and 30 or 90 min after, the inhalation. This pilot study shows no acute or short-term benefits of surfactant inhalation in young adults with cystic fibrosis. However, a beneficial effect of exogenous surfactant cannot be excluded before other reasons for a lack of effect, such as insufficient quantity delivered, inhomogeneous distribution or inhibition of the surfactant in the lungs, have been completely ruled out.


Asunto(s)
Fibrosis Quística/terapia , Lípidos/efectos adversos , Fosfolípidos , Surfactantes Pulmonares/efectos adversos , Administración por Inhalación , Adulto , Aerosoles , Estudios Cruzados , Fibrosis Quística/fisiopatología , Método Doble Ciego , Humanos , Masculino , Proyectos Piloto , Mecánica Respiratoria
12.
Eur J Biochem ; 236(2): 457-64, 1996 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-8612616

RESUMEN

The myeloid differentiation antigen CD14 acts as the major receptor for bacterial lipopolysaccharide (LPS). A soluble form of the protein (sCD14) is present in human serum which functions as a soluble LPS receptor. We have compared the isoform patterns of soluble CD14 derived from human serum and of the recombinant proteins produced by CHO cells transfected with either the wild-type CD14 gene or with a cDNA coding for a truncated protein which lacks the C-terminal 21 amino acids [sCD14-(1-335)-peptide]. Using SDS/PAGE, two dominant isoforms (53 and 50 kDa) and two minor forms (46 and 43 kDa) can be detected in serum as well as in the supernatants of both transfectants. sCD14 is a glycoprotein which carries N- and O-linked carbohydrates. The different isoforms of sCD14-(1-335)-peptide are due to differences in the content of N-linked sugars. However after the removal of N- and O-linked carbohydrates from serum- and CHO-derived wild-type proteins, two isoforms are still present. These results indicate that N-linked glycosylation contributes to but does not fully explain the different forms of soluble CD14. We further examined whether the mutation of individual N-linked glycosylation sites influences the expression of membrane-bound and soluble CD14 forms and the ability of the membrane-bound molecule to bind LPS. As with the wild-type proteins, the different isoforms of the soluble mutants are partially due to differences in N-linked glycosylation. A truncated mutant which lacks the two N-terminal glycosylation sites {[Asp18, Asp132]CD14-(1-335)peptide} does not give rise to multiple forms on SDS gels. Like CD14-(1-335)-peptide, this mutant is not expressed on the cell surface suggesting that a smaller isoform present in the wild-type preparations results from proteolytic cleavage of the membrane-bound molecule. N-linked carbohydrates do not seem to be important for the binding of LPS to membrane-bound CD14.


Asunto(s)
Receptores de Lipopolisacáridos/química , Animales , Secuencia de Bases , Células CHO , Compartimento Celular , Membrana Celular/metabolismo , Cricetinae , Cartilla de ADN/química , Glicosilación , Humanos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Proteínas Recombinantes , Solubilidad
13.
J Immunol ; 155(10): 4588-95, 1995 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-7594457

RESUMEN

CD40 is a member of the TNF receptor family that was first characterized as an important T-B cell interaction molecule. This receptor is also expressed on many other cell types, including normal basal epithelium, carcinomas, and transformed cell lines. The functions of CD40 in non-B cells are largely unknown. Our studies demonstrate that CD40 mediates nuclear factor kappa B (NF-kappa B) mobilization and IL-6 production in nonhematopoietic cells. Stimulation of the transformed fibroblast cell line SV80 with CD40 ligand (CD40L) or anti-CD40 Ab resulted in the production of IL-6; this could be increased by IFN-gamma pretreatment, which is known to up-regulate CD40 expression. Studies with transfectants overexpressing CD40 demonstrated that activation of CD40 alone is sufficient to induce IL-6 production. The transcription factor NF-kappa B appears to play a central role in CD40-mediated activation of the IL-6 gene; NF-kappa B mobilization directly preceded CD40-mediated IL-6 production, and suppression of NF-kappa B mobilization with the metabolic inhibitor D609 also suppressed the IL-6 response. A striking similarity to the requirements for TNF-induced IL-6 production, which is mediated by the p55TNF receptor in SV80 cells, was observed. In view of the intracellular homologies between CD40 and the p55TNF receptor, it should be considered that the two receptors share common components in their signaling pathways that lead to IL-6 production.


Asunto(s)
Antígenos CD40/metabolismo , Interleucina-6/biosíntesis , FN-kappa B/metabolismo , Secuencia de Bases , Antígenos CD40/genética , Ligando de CD40 , Línea Celular Transformada , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Fibroblastos/metabolismo , Regulación de la Expresión Génica , Técnicas de Transferencia de Gen , Humanos , Interferón gamma/farmacología , Glicoproteínas de Membrana/farmacología , Datos de Secuencia Molecular
14.
Eur J Immunol ; 25(8): 2183-9, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7664782

RESUMEN

Tumor necrosis factor (TNF) and lymphotoxin alpha (LT alpha) are closely related cytokines which bind with nearly identical affinities to the same pair of cell surface receptors, p55 and p75TNFR. Therefore it is assumed that TNF and LT alpha are redundant cytokines. This study, however, demonstrates that TNF and LT alpha differ significantly with regard to their mitogenic and cytotoxic potentials. LT alpha's superior mitogenic effect could be explained by its formation of a more stable trimer. In contrast to the TNF trimer, which disintegrated under physiological conditions into biologically inactive monomers, the LT alpha trimer remained stable for several days. Accordingly, LT alpha more effectively induced fibroblast growth which demands long-term presence of the cytokine. TNF's superior cytotoxicity, which requires only short-term impact of the cytokine, could be attributed to a distinct interaction with the human p55TNFR. This was demonstrated in NIH 3T3 cells transfected with the human p55TNFR, where cytotoxicity is mediated exclusively by the transfected receptor. Although the p55ATNFR had virtually identical affinities for TNF and LT alpha, as defined by Scatchard analysis, it nevertheless discriminated between binding of each cytokine and showed a 200-fold enhanced cytotoxicity mediated by TNF.


Asunto(s)
Linfotoxina-alfa/metabolismo , Linfotoxina-alfa/fisiología , Receptores del Factor de Necrosis Tumoral/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/fisiología , Células 3T3 , Animales , Unión Competitiva , División Celular/fisiología , Pruebas Inmunológicas de Citotoxicidad , Estabilidad de Medicamentos , Sustancias de Crecimiento/fisiología , Humanos , Células L , Linfotoxina-alfa/química , Ratones , Transfección , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/química
15.
Eur J Immunol ; 25(2): 604-10, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7533093

RESUMEN

The receptor for lipopolysaccharide LPS (CD14) exists in a membrane-associated (mCD14) and a soluble form (sCD14). Previous studies indicate that monocytes produce sCD14 by limited proteolysis of the membrane-bound receptor. In this study we demonstrate that human monocytes also produce sCD14 by a protease-independent mechanism. To investigate the molecular nature of this second pathway we studied sCD14 formation in the monocytic cell line Mono Mac 6 (MM6) and in CD14 transfectants. Both MM6 and the CD14 transfectants constitutively produce sCD14 by a protease-independent mechanism. Structural analysis of sCD14 produced by the CD14 transfectants reconfirmed the presence of the COOH terminus predicted from the cDNA. Since glycosylphosphatidylinositol anchor attachment is associated with the removal of a hydrophobic C-terminal signal peptide, our finding demonstrates that the transfectants secrete sCD14 which escaped this posttranslational modification. Identical results obtained for sCD14 derived from peritoneal dialysis fluid of a patient with kidney dysfunction show the in vivo relevance of this pathway for sCD14 production.


Asunto(s)
Antígenos CD/biosíntesis , Antígenos de Diferenciación Mielomonocítica/biosíntesis , Monocitos/metabolismo , Receptores Inmunológicos/biosíntesis , Secuencia de Aminoácidos , Antígenos CD/química , Antígenos CD/genética , Antígenos de Diferenciación Mielomonocítica/química , Antígenos de Diferenciación Mielomonocítica/genética , Humanos , Receptores de Lipopolisacáridos , Datos de Secuencia Molecular , Acetato de Tetradecanoilforbol/farmacología , Transfección , Células Tumorales Cultivadas
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