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1.
Artigo em Inglês | MEDLINE | ID: mdl-38629579

RESUMO

OBJECTIVE: We aimed to report our experience on fetal aortic valvuloplasty (FAV) for critical aortic stenosis (AS) focusing on the postnatal evolution of the patients. METHODS: This retrospective study was approved by our local Institutional Review Board (n°2002-0128143827). All fetuses with critical AS who underwent FAV in a single center between 01/2011 and 06/2022 were included. FAV were performed under ultrasound guidance. Technical success was based upon balloon inflation across the aortic valve and improvement of the anterograde aortic flow across the aortic valve. At birth, biventricular circulation (BVC) strategy was decided assuming the left ventricle (LV) systolic and diastolic functions would ensure the systemic circulation. RESULTS: Sixty-three FAV were performed on 58 fetuses at 24.6[21.4-32.4] weeks of gestation. The procedure was successful in 52/58(89.6%) fetuses. There were 11/58(19%) in utero demises and 9/58(15.5%) terminations of pregnancy. There were no liveborn patients after the unsuccessful procedures. 38/58(65.5%) infants were delivered at a median gestational age of 38.1[29-40.6] weeks and 21/38(55.3%) of them required prostaglandin. 28/38(73.7%) [28/58(48.3%)] children entered the BVC path at birth. Among them, 20 required an aortic valvuloplasty at birth (11 percutaneous, 9 surgical) and 8 did not require any treatment at birth but of those, 5/8 underwent a surgical valvuloplasty between day 26 and day 1200 of life. 11/28(39.3%) infants with BVC at birth required a second intervention and four of them required a third intervention. Two infants who entered the BVC at birth underwent a conversion to UVC. None of the surviving children with BVC developed pulmonary hypertension. The global survival rate in case of BVC was 22/28(78.6%) at 23.3[8-112] months of life. 10 patients had UVC at birth. Among them, 6 received comfort care from birth and only 4 underwent surgery. 3/10 patients were still alive at the latest assessment (48[22-102] months). CONCLUSION: FAV for critical aortic stenosis led to anterograde aortic flow in 89.6% of the fetuses, with BVC being achieved in 48.3% (73.7% of the live born). Among patients with BVC at birth, the rate of reintervention is high but long-term survival is satisfactory. This article is protected by copyright. All rights reserved.

2.
Methods Cell Biol ; 138: 137-150, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28129841

RESUMO

As cancers develop, transformed cells hijack various host mechanisms and manipulate them to create a dynamic tumor microenvironment, which supports tumor growth. This protumorigenic microenvironment is made up of many different cell types, including transformed cells, fibroblasts, inflammatory cells, and endothelial cells, the interactions of which have been shown to play a role in sustaining tumor growth. Multiple reports implicate the inflammatory cells of the tumor microenvironment as having both pro- and antitumorigenic roles, the balance of which is vital for the progression of the tumor, and while our understanding of established cancers has vastly increased since the turn of the 21st Century, our knowledge of these cellular interactions at the earliest stages of cancer initiation and development remains relatively limited. This is largely due to difficulties in monitoring these processes in vivo and in real time. Since the late nineties, the zebrafish (Danio rerio) has emerged as a vital model organism, allowing studies of previously unattainable stages of tumor initiation in a vertebrate model system. Using genetic and live-imaging approaches, this model system can be used both independently to monitor stages of tumor progression from the earliest initiation stages and incorporated into previously established systems to investigate the interactions between cancer cells and the various cell types of the tumor microenvironment, including inflammatory cells. Here, we describe the use of an inducible KalTA4-ERT2/UAS expression system in zebrafish, which allows spatial and temporal control of preneoplastic cell (PNC) growth and monitoring of innate immune cells in response to the developing PNC microenvironment.


Assuntos
Imunidade Inata , Imagem Molecular/métodos , Neoplasias/imunologia , Microambiente Tumoral/imunologia , Animais , Animais Geneticamente Modificados , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/genética , Neoplasias/patologia , Peixe-Zebra
3.
Ultrasound Obstet Gynecol ; 41(3): 291-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22605531

RESUMO

OBJECTIVES: To report on a series of 10 fetuses with prenatally diagnosed isolated total anomalous pulmonary venous connection (TAPVC), focusing on echocardiographic features leading to diagnosis, assess accuracy of prenatal diagnosis and describe postnatal outcome. METHODS: In this review of our experience of prenatal diagnosis of isolated TAPVC, we analyzed retrospectively medical records and fetal echocardiography findings in all cases with prenatal diagnosis of isolated TAPVC delivered between 1 January 2001 and 1 October 2011 at a tertiary referral center, paying special attention to echocardiographic signs that led to referral. RESULTS: During the study period, 95 infants with isolated TAPVC were seen at the center. Initially, expert fetal echocardiography identified 14 fetuses with isolated TAPVC. Prenatal diagnosis was made at a mean gestational age of 31 (range, 25-37) weeks. Ten true-positive cases of TAPVC were confirmed after birth. The remaining four were considered false-positive cases: two had normal heart with left superior vena cava to coronary sinus, one had partial anomalous venous connection and one was lost to follow-up. Of the 85 diagnosed postnatally with TAPVC, only one had been seen prenatally by an expert cardiac sonographer. Echocardiographic signs leading to referral were related to pulmonary venous connection in half of the cases. Other suspected defects which led to referral were ostium prium atrial defect (n = 3), left-right asymmetry (n = 1), abnormal mitral valve (n = 1) and hepatic vascular malformation (n = 1). All infants with TAPVC underwent surgery. There was one postoperative death and nine survivors, with a mean follow-up of 31 (range, 2-104) months. CONCLUSION: Fetal diagnosis of isolated TAPVC is challenging even for experts. Echocardiographic anomalies may appear late in gestation. New tools should be proposed to identify abnormal venous drainage at the screening level.


Assuntos
Ecocardiografia/métodos , Doenças Fetais/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Síndrome de Cimitarra/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Feminino , Doenças Fetais/cirurgia , Cardiopatias Congênitas/cirurgia , Humanos , Gravidez , Diagnóstico Pré-Natal , Estudos Retrospectivos , Síndrome de Cimitarra/cirurgia , Resultado do Tratamento
4.
Arch Pediatr ; 19(11): 1264-8, 2012 Nov.
Artigo em Francês | MEDLINE | ID: mdl-22921712

RESUMO

Kawasaki disease (KD) is an acute systemic vasculitis syndrome occurring mostly in children younger than 5 years of age. Especially young infants (<1 year) have an increased risk of coronary artery lesions (CAL). Whereas the etiology of KD is still unknown, progress in treatment during its acute phase has decreased the incidence of CAL from 25-30% to 3-5%. In "atypical KD", the clinical picture is dominated by an unusual symptom as seizure, bloody diarrhea, compressive cervical adenopathy, nephrotic syndrome or hyponatremia. To make a diagnosis in case of "incomplete KD", the supplementary criteria (clinical and biological) suggested by the American Heart Association can be helpful. Once the diagnosis established, the treatment of choice is the intravenous administration of immunoglobulin associated to aspirin at anti-inflammatory dose. However, some patients remain feverish within 36 hours following the end of immunoglobulin administration. This treatment resistance seems increasing in some regions of the globe and can touch up 20% of patients. The unsatisfactory answer to the initial treatment is associated to a higher risk of CAL. Predictive criteria of resistance have been identified and allow to strengthen the medical treatment with a second administration of immunoglobulins. Moreover, methylprednisolone pulse therapy and tumor necrosis factor-alpha blockade (infliximab) appear to be interesting therapeutic options in the future. At last, other treatments have not been the object of controlled studies yet but are alternatives in refractory forms e.g. cytotoxic agents (cyclosporine A, cyclophosphamide, methotrexate), plasmapheresis, plasma exchange or abciximab, especially in patients with aneurysms. Sclerotic vascular changes are often observed in post-Kawasaki disease patients, including those without coronary lesions during the acute phase. Indeed, endothelial dysfunction and risk factors for the development of atherosclerosis, such as dyslipidemia, decreased vascular elasticity, increased C-reactive protein, oxidative stress, and inflammatory cytokines, are known to be present in the late phase of KD. However, it is not clearly established that the survivors of KD carry a higher risk of coronary disease. The epidemiological studies of the next decade should give clearer answers as far as these patients henceforth achieved the age of the atherosclerosis. In conclusion, the diagnosis of KD imposes a strict supervision by a pediatric cardiologist initially. The follow-up is organized according to the existence or non-existence of coronary artery lesions. Late complications as stenosis or coronary thrombosis can occur but remain rare. Thus, it is necessary to be reassuring with the parents, especially for those whose children had no or regressive CAL, while recommending a prevention of the cardiovascular risk factors in the adulthood.


Assuntos
Síndrome de Linfonodos Mucocutâneos/diagnóstico , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Aspirina/uso terapêutico , Pré-Escolar , Terapia Combinada , Ensaios Clínicos Controlados como Assunto , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/tratamento farmacológico , Diagnóstico Diferencial , Humanos , Imunoglobulinas/uso terapêutico , Lactente , Infliximab , Metilprednisolona/uso terapêutico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Prognóstico , Pulsoterapia , Fator de Necrose Tumoral alfa/antagonistas & inibidores
5.
Arch Pediatr ; 18(10): 1087-9, 2011 Oct.
Artigo em Francês | MEDLINE | ID: mdl-21885263

RESUMO

Costello syndrome is a rare association of symptoms caused by de novo germline mutations of the HRAS oncogene interfering in the RAS/mitogen-activated protein kinase (MAPK) signal transduction pathway. Mutations in this pathway are also responsible for Noonan syndrome and the related cardiofaciocutaneous syndrome (CFC) as well as LEOPARD syndrome. The 4 syndromes share phenotypic resemblances concerning patients' morphology but also regarding associated cardiac disease, namely hypertrophic cardiomyopathy, pulmonary stenosis, and atrial septal defect. The electrocardiogram often shows an upper deviation of the QRS axis. Arrhythmias are rare but, if present, are particularly typical of CS. We describe herein two newborn infants with Costello syndrome revealed by atrial tachycardia associated with characteristic morphological and cardiac features of syndromes related to mutations in the RAS/MAPK pathway.


Assuntos
Anormalidades Múltiplas/diagnóstico , Síndrome de Costello/diagnóstico , Taquicardia Paroxística/diagnóstico , Anormalidades Múltiplas/genética , Biomarcadores/sangue , Síndrome de Costello/complicações , Síndrome de Costello/genética , Diagnóstico Diferencial , Feminino , Humanos , Recém-Nascido , Proteínas Quinases Ativadas por Mitógeno/genética , Mutação , Fenótipo , Transdução de Sinais , Taquicardia Paroxística/etiologia , Taquicardia Paroxística/genética , Proteínas ras/genética
6.
J Antimicrob Chemother ; 46(3): 377-84, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10980163

RESUMO

Pseudomonas aeruginosa PAO1 became considerably more sensitive to the action of ampicillin when grown in the presence of certain phospholipids. Only phospholipids capable of forming lipid bilayers or micelles proved to be capable of enhancing ampicillin activity. Of the phospholipids tested, 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphate, also called monopalmitoylphosphatidic acid (MPPA), was the best enhancer. In the absence of MPPA, the MIC and MBC of ampicillin for P. aeruginosa PAO1 were 1 and 2 g/L, respectively. In the presence of MPPA, the MIC and MBC were 20 and 40 mg/L, respectively. MPPA was shown to enhance ampicillin activity by binding both Ca(2+) and Mg(2+), suggesting that the mechanism of enhancement is similar to that previously reported for Ca(2+) and Mg(2+) chelators. Surprisingly, MPPA by itself slowed the growth of four mucoid multiply antibiotic-resistant strains of P. aeruginosa recently isolated from the sputum of cystic fibrosis patients, and enhanced their sensitivity to piperacillin. It also increased the sensitivity of two ceftazidime-resistant P. aeruginosa cystic fibrosis strains to ceftazidime.


Assuntos
Ampicilina/farmacologia , Penicilinas/farmacologia , Fosfolipídeos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Ampicilina/metabolismo , Antibacterianos/farmacologia , Cálcio/metabolismo , Meios de Cultura , Fibrose Cística/microbiologia , Detergentes/farmacologia , Microbiologia Ambiental , Ácidos Graxos/metabolismo , Ácidos Graxos/farmacologia , Humanos , Magnésio/metabolismo , Testes de Sensibilidade Microbiana , Penicilinas/metabolismo , Fosfatidilserinas/metabolismo , Fosfatidilserinas/farmacologia , Fosfolipídeos/metabolismo , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/crescimento & desenvolvimento
7.
Clin Cancer Res ; 6(4): 1432-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10778974

RESUMO

CpG island hypermethylation is a frequent epigenetic event in cancer. We have recently developed an array-based method, called differential methylation hybridization (DMH), allowing for a genome-wide screening of CpG island hypermethylation in breast cancer cell lines (T. H-M. Huang et al., Hum. Mol. Genet., 8: 459-470, 1999). In the present study, DMH was applied to screen 28 paired primary breast tumor and normal samples and to determine whether patterns of specific epigenetic alterations correlate with pathological parameters in the patients analyzed. Amplicons, representing a pool of methylated CpG DNA derived from these samples, were used as hybridization probes in an array panel containing 1104 CpG island tags. Close to 9% of these tags exhibited extensive hypermethylation in the majority of breast tumors relative to their normal controls, whereas others had little or no detectable changes. Pattern analysis in a subset of CpG island tags revealed that CpG island hypermethylation is associated with histological grades of breast tumors. Poorly differentiated tumors appeared to exhibit more hypermethylated CpG islands than their moderately or well-differentiated counterparts (P = 0.041). This early finding lays the groundwork for a population-based DMH study and demonstrates the need to develop a database for examining large-scale methylation data and for associating specific epigenetic signatures with clinical parameters in breast cancer.


Assuntos
Neoplasias da Mama/genética , Ilhas de CpG/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Metilação de DNA , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade
8.
Br J Cancer ; 82(3): 514-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10682657

RESUMO

We examined the methylation status of the transcribed domain of ribosomal DNA (rDNA) in 58 patients with breast cancer. The mean percent of methylation was significantly higher in breast tumours than that of normal control samples (P < 0.0001). This increased rDNA methylation was associated with oestrogen receptor non-expression (P < 0.0273) and with moderately or poorly differentiated tumours as compared to well differentiated tumours (P < 0.0475). Our results suggest that rDNA can be a useful marker for monitoring aberrant methylation during breast tumour progression.


Assuntos
Neoplasias da Mama/metabolismo , Metilação de DNA , DNA Ribossômico/metabolismo , Adulto , Idoso , Southern Blotting , Humanos , Pessoa de Meia-Idade
9.
Breast Cancer Res Treat ; 56(1): 35-43, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10517341

RESUMO

CpG island hypermethylation is known to be associated with transcriptional silencing of tumor suppressor genes in neoplasia. We have previously detected aberrantly methylated sites in the first intron of the Wilms' tumor suppressor (WT1) gene in breast cancer. In the present study, we extended the investigation to a CpG island located in the promoter and first exon regions of WT1. Methylation of this CpG island was found to be extensive in MCF-7 and MDA-MB-231 breast cancer cells, as well as in 25% (five of 20 patients) of primary breast tumors. While levels of the known 3.0-kb WT1 mRNAs were decreased or not detected in these cell lines, the expression could be partially restored following treatment with a demethylation agent, 5-aza-2'-deoxycytidine. Surprisingly, a novel 2.5-kb WT1 transcript was expressed at high levels in both untreated and treated MDA-MB-231 cells. This novel transcript was likely a WT1 variant missing the first exon, and therefore escaped the methylation control present in the normal transcript. Our study implicates the future need to investigate the significance of this aberrant transcript as well as the role of WT1 CpG island hypermethylation in breast neoplasia.


Assuntos
Neoplasias da Mama/genética , Ilhas de CpG/genética , Genes do Tumor de Wilms/genética , Neoplasias da Mama/fisiopatologia , Éxons , Feminino , Humanos , Metilação , Regiões Promotoras Genéticas , Células Tumorais Cultivadas
10.
Hum Mol Genet ; 8(3): 459-70, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9949205

RESUMO

CpG island hypermethylation is known to be associated with gene silencing in cancer. This epigenetic event is generally accepted as a stochastic process in tumor cells resulting from aberrant DNA methyltransferase (DNA-MTase) activities. Specific patterns of CpG island methylation could result from clonal selection of cells having growth advantages due to silencing of associated tumor suppressor genes. Alternatively, methylation patterns may be determined by other, as yet unidentified factors. To explore further the underlying mechanisms, we developed a novel array-based method, called differential methylation hybridization (DMH), which allows a genome-wide screening of hypermethylated CpG islands in tumor cells. DMH was used to determine the methylation status of >276 CpG island loci in a group of breast cancer cell lines. Between 5 and 14% of these loci were hypermethylated extensively in these cells relative to a normal control. Pattern analysis of 30 positive loci by Southern hybridization indicated that CpG islands might differ in their susceptibility to hypermethylation. Loci exhibiting pre-existing methylation in normal controls were more susceptible to de novo methylation in these cancer cells than loci without this condition. In addition, these cell lines exhibited different intrinsic abilities to methylate CpG islands not directly associated with methyltransferase activities. Our study provides evidence that, aside from random DNA-MTase action, additional cellular factors exist that govern aberrant methylation in breast cancer cells.


Assuntos
Neoplasias da Mama/genética , Ilhas de CpG , Metilação de DNA , Sequência de Bases , Southern Blotting/métodos , Neoplasias da Mama/metabolismo , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/genética , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Primers do DNA/genética , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Feminino , Expressão Gênica , Humanos , Hibridização de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase , Células Tumorais Cultivadas
11.
Cancer Res ; 57(6): 1030-4, 1997 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9067264

RESUMO

We have developed a PCR-based method, called methylation-sensitive restriction fingerprinting (MSRF), to screen changes in DNA methylation in breast carcinomas. Two hypermethylation-containing fragments, HBC-1 (for "hypermethylation in breast cancer") and HBC-2, were identified in the amplified breast tumor DNA relative to the amplified normal breast DNA of a patient. Nucleotide sequence analysis revealed no significant matches between the sequence of HBC-1 and the known sequences in the GenBank database, whereas the sequence of HBC-2 matched the upstream region of an antisense WT1 (Wilms' tumor suppressor gene) promoter. The methylation status in the breast tumor DNA from this patient was confirmed by Southern hybridization using HBC-1 and HBC-2 as probes, respectively. Further analysis showed that HBC-1 was methylated aberrantly in 90% (17 of 19 patients) of the primary breast carcinomas examined. This study demonstrates that MSRF provides a useful means for screening aberrant changes in DNA methylation during tumorigenesis. The commonly methylated fragments identified by MSRF could potentially supplement pathological markers currently used for cancers and additionally lead to the discovery of novel methylated tumor suppressor genes.


Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Ilhas de CpG , Impressões Digitais de DNA , Metilação de DNA , DNA de Neoplasias/química , Mapeamento por Restrição , Sequência de Bases , Neoplasias da Mama/química , Carcinoma Ductal de Mama/química , DNA de Neoplasias/genética , DNA de Neoplasias/isolamento & purificação , Marcadores Genéticos , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
12.
FEBS Lett ; 354(3): 320-4, 1994 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-7957948

RESUMO

The association of glutathione (GSH) with putative external chemoreceptors elicits feeding behavior in Hydra. In the present study, solubilized membrane proteins were chromatographed on an affinity column of immobilized GSH in order to isolate GSH-binding proteins that may represent the Hydra GSH chemoreceptor. The most abundant of the affinity-purified proteins was a triplet of peptides ranging in molecular weight from 24.5-26 kDa. Antiserum generated against the 24.5-26 kDa triplet peptides inhibited GSH-stimulated feeding behavior by 47%, implicating a role for one or more of these peptides in Hydra chemoreception.


Assuntos
Proteínas de Transporte/isolamento & purificação , Células Quimiorreceptoras/metabolismo , Glutationa/metabolismo , Hydra/química , Animais , Membrana Celular/química , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Comportamento Alimentar/efeitos dos fármacos , Glutationa/farmacologia , Immunoblotting
13.
Dev Comp Immunol ; 9(4): 627-39, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3936734

RESUMO

Lymphoid preparations from nonimmune rainbow and brook trout were found to lyse murine tumor cells (EL-4 & P815Y) in vitro in an 18 hr 51Cr-release assay conducted at 16-18 degrees C. Lysis was proportional to the effector: target cell ratio, required direct cell to cell contact, and was not depleted by the removal of nylon wool adherent cells. Lymphoid populations from peripheral blood, the thymus, and the anterior kidney, but not the spleen, were active in the cytotoxicity assay. Individual fish varied considerably in their ability to lyse one or both target cells. These data and the results of unlabelled target cell inhibition studies suggest that the reaction is selective if not specific. The addition of PHA to the reaction mixture resulted in markedly enhanced cytotoxic reactivity. In the presence of PHA lysis was readily detectable at 4 hr. The data demonstrate that nonimmune Salmonids possess a cytolytic effector cell population which has considerable cytotoxic potential and may represent a heterogeneous "natural killer cell" population.


Assuntos
Citotoxicidade Imunológica , Linfócitos/imunologia , Salmonidae/imunologia , Truta/imunologia , Animais , Adesão Celular , Técnicas In Vitro , Células Matadoras Naturais/imunologia , Lectinas/imunologia , Leucemia Experimental/imunologia , Sarcoma de Mastócitos/imunologia , Camundongos
14.
J Natl Cancer Inst ; 72(3): 667-72, 1984 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6583449

RESUMO

Spleen cells from syngeneic tumor-bearing mice were examined for direct cell-mediated cytotoxicity (DCMC) and lectin-dependent cell-mediated cytotoxicity (LDCC). In the DCMC assay specific cytotoxicity against the homologous tumor cell was assessed. In the LDCC assay cytotoxicity was nonspecifically assessed against EL-4 cells in the presence of concanavalin A or phytohemagglutinin. Most tumor lines tested (19/22) produced no cytotoxic reactivity in either the DCMC or LDCC assays. In the case of the remaining tumor lines (EL-4, BW5147-3, and P815 Y-3), significant LDCC, but not DCMC, was detected, which indicated that although cytotoxic effector cells had been activated, the reactivity was not directed toward the homologous tumor cell or could not be expressed in the DCMC assay. The EL-4 and BW5147-3 cell lines proved to be sporadic in terms of their ability to induce LDCC, whereas the P815 Y-3 cell line produced consistent LDCC. Reactivity induced by P815 Y-3 cells appeared to be due to the constitutive production and release of a soluble component which could activate cytotoxic T-cells in vivo.


Assuntos
Concanavalina A , Citotoxicidade Imunológica , Neoplasias Experimentais/imunologia , Fito-Hemaglutininas , Animais , Linhagem Celular , Feminino , Leucemia Experimental/imunologia , Ativação Linfocitária , Linfócitos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Transplante de Neoplasias , Especificidade da Espécie , Transplante Isogênico
16.
Immunol Commun ; 11(5): 387-400, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6818136

RESUMO

Cell-mediated cytotoxic reactivity resulting from the in vitro incubation of normal lymphocytes was assessed using nonspecific lectin-dependent cell-mediated cytotoxicity (LDCC) as a measure of overall reactivity. Spleen cells from non-immune C57BL/6 mice were incubated in vitro in RPM1-1640 supplemented with 10% fetal calf serum and 2-mercaptoethanol (2ME). Cytotoxicity was assayed against syngeneic Cr51-labeled EL-4 cells in the presence of Con A or PHA. Optimal LDCC was observed after 8 days of culture in the presence of 5 X 10(-5) M 2ME. Cytotoxicity was mediated by an activated T-lymphocyte population whose development did not appear to require macrophages. Usually LDCC in the presence of PHA was significantly greater than that obtained in the presence of Con A. The presence of 2ME during the initial phase of culture was crucial for the development of cytotoxicity, since early removal of 2ME after 1 or 3 days of culture did not alter the subsequent development of cytotoxicity, whereas delayed addition of 2ME on day 1 or 3 failed to produce cytotoxic reactivity. This rapid conversion from a 2ME sensitive state to a 2ME insensitive state may be related to a rapid loss of accessory cell viability during the early phase of culture. Together the results indicate that this system may provide a useful model for the investigation of the events leading to the development of CTL in vitro.


Assuntos
Citotoxicidade Imunológica/efeitos dos fármacos , Lectinas/farmacologia , Linfócitos/efeitos dos fármacos , Mercaptoetanol/farmacologia , Animais , Técnicas In Vitro , Linfócitos/imunologia , Sarcoma de Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Sarcoma Experimental/imunologia , Baço/imunologia
20.
Immunol Commun ; 9(6): 559-68, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-6776030

RESUMO

Mice were challenged with high (10(8)) or low (10(4)) numbers of allogenic tumor cells and assessed for cellular immunity. The responses obtained indicated that high dose challenge produced both delayed-type hypersensitivity (DTH) and cell-mediated cytotoxic reactivity (DCMC), while low dose challenge produced DTH, an apparent suppressive effect, and little or no DCMC. Pretreatment with 100 mg/kg of cyclophosphamide (CTX) 3 d before antigen failed to alter this pattern, but treatment 3 d after antigen administration abrogated both DTH and DCMC. Animals given a combined modulating protocol consisting of an initial low dose challenge followed on day 3 by CTX treatment and day 6 by a high dose challenge developed DCMC in the presence of a greatly reduced or absent DTH response. These results demonstrate the differential effects of allogeneic challenge dose on the development of cellular immunity; the differential effects of CTX treatment given prior to or following alloimmunization, and demonstrate how these effects can be combined to modulate the immune response by selectively activating subpopulations of T-lymphocytes.


Assuntos
Ciclofosfamida/farmacologia , Citotoxicidade Imunológica , Hipersensibilidade Tardia/imunologia , Animais , Relação Dose-Resposta Imunológica , Imunidade Celular , Sarcoma de Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL
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