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1.
Strahlenther Onkol ; 199(11): 973-981, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37268767

RESUMO

PURPOSE: The aim of this study was to evaluate interobserver agreement (IOA) on target volume definition for pancreatic cancer (PACA) within the Radiosurgery and Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (DEGRO) and to identify the influence of imaging modalities on the definition of the target volumes. METHODS: Two cases of locally advanced PACA and one local recurrence were selected from a large SBRT database. Delineation was based on either a planning 4D CT with or without (w/wo) IV contrast, w/wo PET/CT, and w/wo diagnostic MRI. Novel compared to other studies, a combination of four metrics was used to integrate several aspects of target volume segmentation: the Dice coefficient (DSC), the Hausdorff distance (HD), the probabilistic distance (PBD), and the volumetric similarity (VS). RESULTS: For all three GTVs, the median DSC was 0.75 (range 0.17-0.95), the median HD 15 (range 3.22-67.11) mm, the median PBD 0.33 (range 0.06-4.86), and the median VS was 0.88 (range 0.31-1). For ITVs and PTVs the results were similar. When comparing the imaging modalities for delineation, the best agreement for the GTV was achieved using PET/CT, and for the ITV and PTV using 4D PET/CT, in treatment position with abdominal compression. CONCLUSION: Overall, there was good GTV agreement (DSC). Combined metrics appeared to allow a more valid detection of interobserver variation. For SBRT, either 4D PET/CT or 3D PET/CT in treatment position with abdominal compression leads to better agreement and should be considered as a very useful imaging modality for the definition of treatment volumes in pancreatic SBRT. Contouring does not appear to be the weakest link in the treatment planning chain of SBRT for PACA.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , Neoplasias Pancreáticas , Radiocirurgia , Humanos , Radiocirurgia/métodos , Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/radioterapia , Adenocarcinoma/cirurgia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Variações Dependentes do Observador , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/radioterapia , Neoplasias Pancreáticas/cirurgia , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Pulmonares/radioterapia , Neoplasias Pancreáticas
2.
Phys Rev Lett ; 125(6): 069901, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32845694

RESUMO

This corrects the article DOI: 10.1103/PhysRevLett.120.223602.

3.
Radiat Oncol ; 13(1): 185, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30241556

RESUMO

BACKGROUND: Prostate cancer (PCA) is the most-prevalent non-skin cancer in men worldwide. Nevertheless, the treatment of oligometastatic, especially lymph-node (ln) recurrent, PCA remains elusive. The aim of our study was to provide insights in radiotherapy (RT)-treatment of recurrent PCA exhibiting ln- or osseous (oss)-oligometastases. METHODS: Between April 2012 and April 2017, 27 oligometastatic PCA patients (19 ln and 8 single oss) were treated with RT at our institution. RESULTS: The metastasis-free survival (MFS) was 24.8 m (22.0-36.0 m) and 25.4 m (23.9-28.1 m) for the ln- and oss-subgroup resulting in 1-year MFS of 75.4 and 100% and 2-year MFS of 58.7 and 83.3% for ln- and oss-metastatic patients, respectively. Of notice, none of the recurrences for ln-patients was in the RT-field, constituting a local control of 100%. Within the ln-group, pre-RT median-PSA was 2.6 ng/ml, median post-RT PSA was 0.3 ng/ml, which was significant (p = 0.003). Median biochemical-free survival (bfS) was 12.2 m. PCA that was initially confined to the prostate had a better bfS (p < 0.001) and MFS (p = 0.013). The oss-group had a median PSA of 4.9 ng/ml pre-treatment which dropped to a median value of 0.14 ng/ml (p = 0.004). Toxicities were moderate, with only 1 case of III° toxicity. There were no deaths in the ln-group, thus overall survial was 100% here. CONCLUSION: Our study points out the feasibility of RT as a treatment option in recurrent PCA and demonstrates an excellent local control with a low-toxicity profile.


Assuntos
Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/secundário , Recidiva Local de Neoplasia/radioterapia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Idoso , Estudos de Viabilidade , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/cirurgia , Terapia de Salvação/métodos , Resultado do Tratamento
4.
Phys Rev Lett ; 120(22): 223602, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29906155

RESUMO

We observe cavity mediated spin-dependent interactions in an off-resonantly driven multilevel atomic Bose-Einstein condensate that is strongly coupled to an optical cavity. Applying a driving field with adjustable polarization, we identify the roles of the scalar and the vectorial components of the atomic polarizability tensor for single and multicomponent condensates. Beyond a critical strength of the vectorial coupling, we infer the formation of a spin texture in a condensate of two internal states from the analysis of the cavity output field. Our work provides perspectives for global dynamical gauge fields and self-consistently spin-orbit coupled gases.

5.
Zentralbl Chir ; 140(5): 486-92, 2015 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-25401371

RESUMO

BACKGROUND: The significance of endovascular therapy for mesenteric ischaemia (MI) is being debated. Despite initially lower mortality and morbidity, inconsistent early and late results led to questions concerning indications and technical applications of the procedure. METHODS: 91 patients with MI underwent endovascular treatment in a period of 11 years. In 78 (85.7 %) patients a stent was deployed and in 13 (14.3 %) an angioplasty was performed, principally of the superior mesenteric artery (n = 81/91, 89 %). Follow-up consisted of a clinical and an ultrasound examination in all cases. Mean follow-up was 4.2 years. Our results were compared to those in the literature. RESULTS: Endovascular treatment of the intestinal arteries accounted for 0.6 % of all vascular procedures. Seven of 91 patients (7.7 %) died after an initial PTA/stenting. The overall peri-interventional morbidity was 6.6 % (n = 6/91). Medium- to long-term complications were encountered in 20 patients (22 %), primarily during the first year (85 %). Six of 91 patients developed an in-stent stenosis (6.6 %) and 14/91 patients (15.4 %) stent occlusion. Additionally 2 dislocated stents (2.2 %) and an arterial perforation with bleeding into the mesentery (1.1 %) were seen. Although 3 of these 20 patients were successfully treated with an additional PTA or stenting (15.0 %; n = 3/91, 3.3 %), surgical conversion was necessary in 9 (n = 9/20, 45 %; n = 9/91, 9.9 %). The postoperative mortality was respectively 22.2 % (n = 2/9; n = 2/91, 2.2 %). In the case of acute MI, endovascular procedures are only indicated for patients without peritonitis. In chronic MI, the indication for endovascular treatment depends on the type of occlusion and the vascular anatomy. Despite favourable early results, the outcome of endovascular treatment deteriorates with time reaching a 1-year patency rate of 63 % in a multicentre analysis. This leads to secondary procedures in 30 %. A surgical conversion carries a high mortality. CONCLUSION: The endovascular treatment of intestinal artery disease cannot be considered the treatment of choice, it is rather an alternative method in patients with functional or local contraindications to surgery. Life-long follow-up is necessary to prevent stent complications with fatal consequences. A prospective randomised study concerning the evaluation of the advantages and disadvantages of surgical and endovascular therapy of intestinal artery occlusive disease is required.


Assuntos
Procedimentos Endovasculares/métodos , Isquemia Mesentérica/cirurgia , Oclusão Vascular Mesentérica/cirurgia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia , Criança , Doença Crônica , Conversão para Cirurgia Aberta/estatística & dados numéricos , Feminino , Seguimentos , Humanos , Imageamento Tridimensional , Incidência , Masculino , Artérias Mesentéricas/cirurgia , Isquemia Mesentérica/mortalidade , Oclusão Vascular Mesentérica/mortalidade , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/mortalidade , Análise de Sobrevida , Tomografia Computadorizada por Raios X , Adulto Jovem
6.
Zentralbl Chir ; 139(5): 487-90, 2014 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-25313887

RESUMO

In the future vascular medicine will still have a great impact on health of people. It should be noted that the aging of the population does not lead to a dramatic increase in patient numbers, but will be associated with a changing spectrum of co-morbidities. In addition, vascular medical research has to include the intensive care special features of vascular patients, the involvement of vascular medicine in a holistic concept of fast-track surgery, a geriatric-oriented intensive monitoring and early geriatric rehabilitation. For the future acceptance of vascular medicine as a separate subject area under delimitation of cardiology and radiology is important. On the other hand, the subject is so complex and will become more complex in future specialisations that mixing of surgery and angiology is desirable, with the aim to preserve the vascular surgical knowledge and skills on par with the medical and interventional measures and further develop them. Only large, interdisciplinary guided vascular centres will be able to provide timely diagnosis and therapy, to deal with the growing multi-morbidity of the patient, to perform complex therapies even in an acute emergency and due to sufficient number of cases to present with well-trained and experienced teams. These requirements are mandatory to decrease patients' mortality step by step.


Assuntos
Cardiologia/tendências , Idoso , Comorbidade , Comportamento Cooperativo , Estudos Transversais , Previsões , Alemanha , Necessidades e Demandas de Serviços de Saúde/tendências , Humanos , Comunicação Interdisciplinar , Dinâmica Populacional , Doenças Vasculares/mortalidade , Doenças Vasculares/terapia , Procedimentos Cirúrgicos Vasculares/tendências
7.
Clin Pharmacol Ther ; 88(2): 204-13, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20164833

RESUMO

Glioblastoma multiforme (GBM) is the most common and most aggressive primary brain tumor in humans. Systemic immunity against gene therapy vectors has been shown to hamper therapeutic efficacy; however, helper-dependent high-capacity adenovirus (HC-Ad) vectors elicit sustained transgene expression, even in the presence of systemic anti-adenoviral immunity. We engineered HC-Ads encoding the conditional cytotoxic herpes simplex type 1 thymidine kinase (TK) and the immunostimulatory cytokine fms-like tyrosine kinase ligand 3 (Flt3L). Flt3L expression is under the control of the regulatable Tet-ON system. In anticipation of a phase I clinical trial for GBM, we assessed the therapeutic efficacy, biodistribution, and clinical and neurotoxicity with escalating doses of HC-Ad-TetOn-Flt3L + HC-Ad-TK in rats. Intratumoral administration of these therapeutic HC-Ads in rats bearing large intracranial GBMs led to long-term survival in approximately 70% of the animals and development of antiglioma immunological memory without signs of neuropathology or systemic toxicity. Systemic anti-adenoviral immunity did not affect therapeutic efficacy. These data support the idea that it would be useful to develop HC-Ad vectors further as a therapeutic gene-delivery platform to implement GBM phase I clinical trials.


Assuntos
Adenoviridae/genética , Neoplasias Encefálicas/terapia , Vetores Genéticos/farmacocinética , Vetores Genéticos/uso terapêutico , Glioblastoma/terapia , Adenoviridae/imunologia , Adjuvantes Imunológicos/uso terapêutico , Animais , Comportamento Animal , Neoplasias Encefálicas/psicologia , Ensaios Clínicos Fase I como Assunto , Relação Dose-Resposta Imunológica , Dosagem de Genes , Terapia Genética , Vetores Genéticos/efeitos adversos , Glioblastoma/psicologia , Humanos , Imuno-Histoquímica , Injeções , Transplante de Neoplasias , Ratos , Análise de Sobrevida , Distribuição Tecidual , Transgenes/genética
8.
J Virol ; 83(4): 2004-10, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19073729

RESUMO

Increased transgene expression per vector genome is an important goal in the optimization of viral vectors for gene therapy. Herein we demonstrate that herpes simplex virus type 1 (HSV1) thymidine kinase (TK) gene sequences (1,131 bp) fused to the 3' end of lacZ increase transgene expression from high-capacity adenoviral vectors (HCAd), but not from first-generation (Ad) vectors. The woodchuck hepatitis virus posttranscriptional regulatory element (WPRE), in contrast, increased transgene expression levels from Ad but not HCAd vectors. The differential activity of the HSV1 TK gene and WPRE sequences was detected both in vitro and in vivo and suggests potentially different mechanisms of action or the interaction of these elements with vector genomic sequences.


Assuntos
Adenoviridae/genética , Vetores Genéticos , Herpesvirus Humano 1/enzimologia , Timidina Quinase/genética , Timidina Quinase/metabolismo , beta-Galactosidase/genética , beta-Galactosidase/metabolismo , Expressão Gênica , Vírus da Hepatite B da Marmota/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
9.
Clin Res Cardiol ; 97(1): 43-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17874036

RESUMO

BACKGROUND: Vascular closure devices (VCD) are well established to facilitate hemostasis after cardiac catheterization procedures. However, impairment of flow due to the reduction of femoral artery diameter remains a major concern. The present study aims to evaluate leg perfusion before and after application of collagen- and suture-based vascular closure devices. METHODS: A total of 366 patients (age: 64.3 years+/-10.7, male: 71.3%) were randomized to receive femoral access site closure with either a collagen-based closure device (group A) (n=214) or a suture-mediated device (group B) (n=152), immediately following coronary catheterization procedures. In all patients, the ankle-brachial-index (ABI) was measured before and the day after closure device application. RESULTS: In group A, mean ABI at baseline was 1.09+/-0.2, in group B 1.11+/-0.2. In both groups, there was a significant, albeit clinically not relevant, reduction in post-procedural ABI (group A: 1.04+/-0.2, p<0.01 vs baseline, group B: 1.06+/-0.2, p<0.01 vs baseline). DeltaABI was not different between both VCD groups (p=0.55). In patients with peripheral vascular disease (PVD), neither the Angioseal device (mean ABI at baseline 0.76+/-0.1) nor the Perclose-device (mean ABI at baseline 0.79+/-0.1) induced a remarkable impairment of leg perfusion (Angioseal: 0.77+/-0.1, p=0.9 vs baseline, Perclose: 0.78+/-0.1, p=1.0 vs baseline). Clinically, no aggravation of claudication was observed in the PVD patient group. CONCLUSION: Both vascular closure devices are not associated with clinically relevant reduction in ABI. There was no difference between the two groups with respect to the level of flow impairment. Both devices may be safely used in patients with reduced ABI.


Assuntos
Cateterismo Cardíaco , Colágeno , Complicações Pós-Operatórias/etiologia , Técnicas de Sutura , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Velocidade do Fluxo Sanguíneo , Feminino , Artéria Femoral/cirurgia , Hemostasia , Humanos , Claudicação Intermitente/cirurgia , Perna (Membro)/irrigação sanguínea , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/cirurgia , Estudos Prospectivos
11.
Hum Gene Ther ; 17(5): 531-44, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16716110

RESUMO

First-generation adenoviral (Ad) and high-capacity adenoviral (HC-Ad) vectors are efficient delivery vehicles for transferring therapeutic transgenes in vivo into tissues/organs. The initial successes reported with adenoviral vectors in preclinical trials have been limited by immune-related adverse side effects. This has been, in part, attributed to the use of poorly characterized preparations of adenoviral vectors and also to the untoward immune adverse side effects elicited when high doses of these vectors were used. HC-Ads have several advantages over Ads, including the lack of viral coding sequences, which after infection and uncoating, makes them invisible to the host's immune system. Another advantage is their large cloning capacity (up to approximately 35 kb). However, accurate characterization of HC-Ad vectors, and of contaminating replication-competent adenovirus (RCA) or helper virus, is necessary before these preparations can be used safely in clinical trials. Consequently, the development of accurate, simple, and reproducible methods to standardize and validate adenoviral preparations for the presence of contaminant genomes is required. By using a molecular method that allows accurate, reproducible, and simultaneous determination of HC-Ad, contaminating helper virus, and RCA genome copy numbers based on real-time quantitative PCR, we demonstrate accurate detection of these three genomic entities, within CsCl-purified vector stocks, total DNA isolated from cells transduced in vitro, and from brain tissue infected in vivo. This approach will allow accurate assessment of the levels and biodistribution of HC-Ad and improve the safety and efficacy of clinical trials.


Assuntos
Adenoviridae/genética , Vetores Genéticos/normas , Genoma Viral , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/normas , Adenoviridae/isolamento & purificação , Animais , Sequência de Bases , Bioensaio , Encéfalo/virologia , Linhagem Celular , DNA Viral/metabolismo , Feminino , Vetores Genéticos/efeitos adversos , Vírus Auxiliares/genética , Vírus Auxiliares/isolamento & purificação , Camundongos
12.
Int Angiol ; 23(1): 29-34, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15156127

RESUMO

AIM: To determine the prevalence of varicose veins in the German population and specify possible risk factors the data of the Duesseldorf/Essen civil servants study were analysed. METHODS: From December 1989 to July 1993 a total of 9 935 employees were recruited. All volunteers filled out a questionnaire regarding family history and risk factors and were clinically examined. Venous findings were classified and adapted to the CEAP-classification. For the analysis of risk factors only volunteers classified as CEAP-class 0 or as CEAP-class II were considered: 4 250 men, 10% belonged to CEAP-class II and 2 380 women including 16% CEAP-class II. RESULTS: In general, age and gender were the most relevant risk factors for varicose veins. Odds ratio age: male: 3.4 (95%-CI: 2.6-4.4), age female 6.5 (95%-CI: 5.0-8.5), gender 2.3 (95%-CI 1.9-2.7). In addition in females the most frequent risk factors were oral contraception and in both genders a predominately sitting posture at work. Regarding the family history, varicose veins by the mother was most frequent compared to varicose veins by the father or both. After adjusting for age and gender heridity became the most important risk factor with an odds ratio of 5.2 (95%-CI:3.7-7.3-4.50) in case of varicose veins present in both parents, followed by a standing posture at work 2.2 (95%-CI: 1.2-3.9). In contrast, smoking also reached a significant level, but with a decreased odds ratio of 0.66 (95%-CI: 0.57-0.77) indicating a protective effect. CONCLUSION: In addition to age and gender a family history of varicose veins is the most important risk factor in the total population. Despite significant influence of other risk factors their relevance for varicose veins in the investigated population is low either due to low frequencies or low odds ratios.


Assuntos
Varizes/epidemiologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Varizes/etiologia
13.
J Fam Pract ; 50(12): 1040-6, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11742605

RESUMO

OBJECTIVE: We compared fluid-based cytologies (FBC) with conventional Papanicolaou (Pap) tests (CT) to determine if either is superior. STUDY DESIGN: This was a systematic review of original research reports evaluating both CT and FBC with respect to specimen adequacy, comparison with a reference standard, or both. Two reviewers independently reviewed the titles, abstracts, and full articles to determine inclusion status, with differences resolved by consensus with a third author. Risk differences (RD) between occurrence rates for FBC and CT were used for the specimen adequacy data. Sensitivity and specificity were pooled independently and weighted by the inverse of the variance using a random effects model. DATA SOURCES: Studies published between 1985 and November 1999 were identified from MEDLINE, Best Evidence, EMBASE, Biological Abstracts/RRM, and The Cochrane Library. OUTCOMES MEASURED: Sensitivity, specificity, area under the receiver operating characteristic curve (AuROC), and the proportion of satisfactory, unsatisfactory, and "satisfactory but limited by" test results were measured. RESULTS: There was no significant difference in AuROC (P = .37). FBC specimens were more likely to be satisfactory (RD=0.06; 95% confidence interval [CI], 0.03-0.09) or to have absent endocervical cells (RD=0.06; 95% CI, 0.02-0.10) but had 10% fewer "satisfactory but limited by - other" reports (RD = -0.10; 95% CI, -0.14 to -0.06). There was no difference in unsatisfactory Pap test results. CONCLUSIONS: For most women there is no reason to replace CT with FBC. For women at high risk of cervical cancer or who are screened infrequently, the possible increase in FBC sensitivity may outweigh the potential harms from additional false positives.


Assuntos
Técnicas Histológicas/métodos , Teste de Papanicolaou , Neoplasias do Colo do Útero/patologia , Esfregaço Vaginal/métodos , Intervalos de Confiança , Medicina Baseada em Evidências , Feminino , Humanos , Programas de Rastreamento/métodos , Probabilidade , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/diagnóstico
14.
J Biol Chem ; 275(24): 18432-40, 2000 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-10748079

RESUMO

Glucocorticoid drugs suppress tumor necrosis factor-alpha (TNF-alpha) synthesis by activated monocyte/macrophages, contributing to an anti-inflammatory action in vivo. In lipopolysaccharide (LPS)-activated human monocytic THP-1 cells, glucocorticoids acted primarily on the TNF-alpha promoter to suppress a burst of transcriptional activity that occurred between 90 min and 3 h after LPS exposure. LPS increased nuclear c-Jun/ATF-2, NF-kappaB(1)/Rel-A, and Rel-A/C-Rel transcription factor complexes, which bound specifically to oligonucleotide sequences from the -106 to -88 base pair (bp) region of the promoter. The glucocorticoid, dexamethasone, suppressed nuclear binding activity of these complexes prior to and during the critical phase of TNF-alpha transcription. Site-directed mutagenesis in TNF-alpha promoter-luciferase reporter constructs showed that the adjacent c-Jun/ATF-2 (-106 to -99 bp) and NF-kappaB (-97 to -88 bp) binding sites each contributed to the LPS-stimulated expression. Mutating both sites largely prevented dexamethasone from suppressing TNF-alpha promoter-luciferase reporters. LPS exposure also increased nuclear Egr-1 and PU.1 abundance. The Egr-1/Sp1 (-172 to -161 bp) binding sites and the PU.1-binding Ets site (-116 to -110 bp) each contributed to the LPS-stimulated expression but not to glucocorticoid response. Dexamethasone suppressed the abundance of the c-Fos/c-Jun complex in THP-1 cell nuclei, but there was no direct evidence for c-Fos/c-Jun transactivation through sites in the -172 to -52 bp region. Small contributions to glucocorticoid response were attributable to promoter sequences outside the -172 to -88 bp region and to sequences in the TNF-alpha 3'-untranslated region. We conclude that glucocorticoids suppress LPS-stimulated secretion of TNF-alpha from human monocytic cells largely through antagonizing transactivation by c-Jun/ATF-2 and NF-kappaB complexes at binding sites in the -106 to -88 bp region of the TNF-alpha promoter.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Glucocorticoides/farmacologia , Monócitos/metabolismo , NF-kappa B/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional , Fator de Necrose Tumoral alfa/biossíntese , Fator 2 Ativador da Transcrição , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Humanos , Lipopolissacarídeos/farmacologia , Luciferases/metabolismo , Camundongos , Dados de Sequência Molecular , Ativação Transcricional/efeitos dos fármacos , Transfecção , Fator de Necrose Tumoral alfa/genética
15.
Cytokine ; 12(2): 110-9, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10671295

RESUMO

The authors have previously demonstrated that the tumour necrosis factor (TNF) -308 G/A polymorphism affects the binding of transcription factors. In transient transfection assays in PMA stimulated U937 monocytes and Jurkat T cells, the A-containing TNF2 promoter has a 2-3-fold greater transcriptional activity than the TNF1 promoter in the presence of the TNF 3'UTR. In this study it was found that a difference in TNF1 and TNF2 promoter activities was only observed in U937 and Jurkat cells, and not in Raji (B cell line), HeLa (epithelial carcinoma cell line), HepG2 (hepatoma cell line) or THP-1 (monocyte), suggesting cell-type specific transcription factors or modifications may be involved in the formation of the -308 protein/DNA complex. Physiological stimulators, TNF and interferon gamma (IFN-gamma) did not cause differential promoter activity between TNF1 and TNF2, but LPS did with only the TNF2 promoter/3'UTR construct being significantly responsive to lipopolysaccharide (LPS) in U937 cells. In U937 cells, the -308 polymorphism affected transcription following differentiation by phorbol myristate acetate (PMA), retinoic acid, PMA plus LPS and PMA plus retinoic acid with an increase in nuclear factor binding to both TNF1 and TNF2 in the -323 to -285 region being observed. The greatest difference between TNF2 and TNF1 promoter activities (5-fold) was observed following PMA plus retinoic acid treatment of transfected U937 cells for 48h. During this time, U937 differentiated into cells with a macrophage-like morphology. An understanding of the cell type and stimuli specific requirements for differential expression of the -308 polymorphism may help elucidate the role the TNF -308 polymorphism plays in diseases where elevated TNF levels are thought to be important.


Assuntos
Polimorfismo Genético , Regiões Promotoras Genéticas , Fator de Necrose Tumoral alfa/genética , Regiões 3' não Traduzidas , Sequência de Bases , Sítios de Ligação/genética , Diferenciação Celular , Linhagem Celular , DNA/genética , DNA/metabolismo , Expressão Gênica , Células HeLa , Humanos , Células Jurkat , Proteínas Nucleares/metabolismo , Transfecção , Células U937
16.
J Leukoc Biol ; 66(4): 562-6, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10534109

RESUMO

A biallelic G (TNF1 allele) to A (TNF2 allele) polymorphism 308 nucleotides upstream from the transcription initiation site in the tumor necrosis factor (TNF) promoter is associated with elevated TNF levels and disease susceptibilities observed in human subjects. The TNF2 allele is strongly associated with the high-TNF-producing autoimmune MHC haplotype HLA-A1, B8, DR3, with elevated serum TNF levels and a more severe outcome in infectious diseases, such as cerebral malaria. A number of groups have set out to determine whether the -308 polymorphism could affect transcription factor binding and hence influence TNF transcription and expression levels. Although some studies have failed to show any functional difference between the two allelic forms, others have shown that the -308 polymorphism effected transcription factor binding to the region encompassing -308, with the region in the TNF2 allele showing altered binding characteristics. The -308 polymorphism also has been found by some groups to be functionally significant in reporter gene assays in Raji B cells, Jurkat T cells, and U937 pre-monocytic cells. Up to fivefold differences can be measured between TNF1 and TNF2 allelic constructs when the TNF 3'UTR is present, indicating a role in the expression of the polymorphism. Although controversial, the majority of the data support a direct role for the TNF2 -308 allele in the elevated TNF levels observed in TNF2 homozygotes and HLA-A1, B8, DR3 individuals. Elevated TNF levels due to the -308 polymorphism may alter the immune response such that it confers susceptibility to certain autoimmune and infectious diseases.


Assuntos
Regulação da Expressão Gênica , Polimorfismo Genético , Regiões Promotoras Genéticas , Fator de Necrose Tumoral alfa/genética , Animais , Humanos , Imunidade , Fatores de Transcrição/metabolismo , Transcrição Gênica , Fator de Necrose Tumoral alfa/imunologia
17.
Mol Immunol ; 34(5): 391-9, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9293772

RESUMO

Since the tumor necrosis factor alpha (TNF-alpha) gene was found to be located in the central major histocompatibility complex (MHC) there has been much speculation concerning a genetic association between particular TNF alleles and disease susceptibility. A relationship between the MHC haplotype A1, B8, DR3, TNF-alpha expression levels and susceptibility to autoimmune disease has been suggested by several groups. The identification of the -308 polymorphism and its association with the HLA A1, B8, DR3 haplotype have led to speculation that the polymorphism may play a role in the altered expression of TNF-alpha. We have demonstrated that the region (-323 to -285) encompassing -308 in the TNF2 allele binds nuclear factors differently to the same region in the promoter of the more common TNF1 allele. The G/A -308 polymorphism affected the affinity of factor binding and resulted in a factor binding to TNF2 but not TNF1. The observed differential binding was shown to be functional, with the 38bp region from TNF2 causing a two-fold greater activity of a heterologous promoter over that due to the same region in TNF1. To further substantiate the functional consequences of the TNF-alpha -308 polymorphism, we analysed both allelic forms of the TNF-alpha promoter region (-993 to +110) in a transient transfection assay, using luciferase as a reporter gene. The results showed that when present with the 3'UTR the -308A allelic form gave a two-fold greater level of transcription than the 308G form in PMA-stimulated Jurkat and U937 cells. This suggests that the -308 G/A polymorphism may play a role in the altered TNF-alpha gene expression observed in individuals with the HLA A1, B8, DR3 haplotype.


Assuntos
Polimorfismo Genético , Regiões Promotoras Genéticas/imunologia , Transcrição Gênica/imunologia , Fator de Necrose Tumoral alfa/genética , Sequência de Bases , Carcinoma Hepatocelular , Linhagem Celular Transformada , Proteínas de Ligação a DNA/metabolismo , Células HeLa , Humanos , Células Jurkat , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/metabolismo
18.
Biochem Mol Biol Int ; 40(1): 43-51, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8886268

RESUMO

We have identified a region of the human TNF-alpha promoter between nucleotides -323 and -285, capable of influencing transcriptional activity. This region encompasses the -308 polymorphism and contains a 10 bp sequence homologous to the consensus binding site of activator protein-2 (AP-2). Protein complexes derived from U937 and Jurkat cells were found to bind to this element. Competitive EMSA using a consensus AP-2 oligonucleotide indicated that AP-2 may be involved. Functional assays demonstrate that this region can repress activity of a heterologous promoter in the Jurkat T-cell line, but act as an inducible enhancer of transcription in U937 cells.


Assuntos
Proteínas de Ligação a DNA/química , Fatores de Transcrição/química , Fator de Necrose Tumoral alfa/genética , Eletroforese em Gel de Poliacrilamida , Regulação da Expressão Gênica , Humanos , Células Jurkat , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição AP-2 , Transfecção
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