Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
Nat Commun ; 13(1): 5219, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-36064947

RESUMO

The development dynamics and self-organization of glandular branched epithelia is of utmost importance for our understanding of diverse processes ranging from normal tissue growth to the growth of cancerous tissues. Using single primary murine pancreatic ductal adenocarcinoma (PDAC) cells embedded in a collagen matrix and adapted media supplementation, we generate organoids that self-organize into highly branched structures displaying a seamless lumen connecting terminal end buds, replicating in vivo PDAC architecture. We identify distinct morphogenesis phases, each characterized by a unique pattern of cell invasion, matrix deformation, protein expression, and respective molecular dependencies. We propose a minimal theoretical model of a branching and proliferating tissue, capturing the dynamics of the first phases. Observing the interaction of morphogenesis, mechanical environment and gene expression in vitro sets a benchmark for the understanding of self-organization processes governing complex organoid structure formation processes and branching morphogenesis.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Carcinoma Ductal Pancreático/patologia , Camundongos , Morfogênese , Organoides/metabolismo , Pâncreas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas
2.
J Clin Pharmacol ; 57(11): 1432-1443, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28703316

RESUMO

Ertugliflozin is a highly selective and potent inhibitor of the sodium-glucose cotransporter 2 in development for the treatment of type 2 diabetes mellitus. The glycemic efficacy of sodium-glucose cotransporter 2 inhibitors such as ertugliflozin depends on glucose filtration through the kidney. This phase 1, open-label study evaluated the effect of renal impairment on the pharmacokinetics, pharmacodynamics, and tolerability of ertugliflozin (15 mg) in type 2 diabetes mellitus and healthy subjects with normal renal function (estimated glomerular filtration rate not normalized for body surface area ≥90 mL/min) and type 2 diabetes mellitus subjects with mild (60-89 mL/min), moderate (30-59 mL/min), or severe (<30 mL/min) renal impairment (n = 36). Blood and urine samples were collected predose and over 96 hours postdose for pharmacokinetic evaluation and measurement of urinary glucose excretion over 24 hours. Log-linear regression analyses indicated predicted mean area under the concentration-time curve values for mild, moderate, and severe renal function groups that were ≤70% higher relative to subjects with normal renal function. Generally consistent results were obtained with categorical analysis based on analysis of variance. The increase in ertugliflozin exposure in subjects with renal impairment is not expected to be clinically meaningful. Regression analysis of change from baseline in urinary glucose excretion over 24 hours vs estimated glomerular filtration rate showed a decrease in urinary glucose excretion with declining renal function. A single 15-mg dose of ertugliflozin was well tolerated in all groups.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insuficiência Renal/metabolismo , Idoso , Glicemia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Taxa de Filtração Glomerular/fisiologia , Glucose/metabolismo , Glucosídeos/metabolismo , Humanos , Rim/metabolismo , Masculino , Pessoa de Meia-Idade , Transportador 2 de Glucose-Sódio/metabolismo
4.
Nervenarzt ; 88(8): 866-873, 2017 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-28597028

RESUMO

Language processing requires the coordinated interaction of local and distant neural populations within distributed networks of the temporal, frontal and parietal brain regions. Poststroke aphasia is the consequence of both local as well as remote dysfunction within language-specific and domain-general networks. Language recovery, in turn, rests on reorganization processes within these networks. These comprise the resolution of an acute network failure (i. e. diaschisis), the subacute activation of right hemisphere homologous regions and the gradual reintegration of left hemisphere remote and perilesional areas. The application of unifocal noninvasive brain stimulation over these regions provides a means of modulating neural plasticity in order to enhance the reorganization processes underlying language recovery. The lack of knowledge as to the optimal stimulation site, the appropriate stimulation protocol and the proper timing of interventions might explain the only marginal effects of brain stimulation adjunct to speech and language therapy. In addition, individually different contributions of left and right hemisphere regions to recovery due to heterogeneous lesion sites among patients limit the possibility to identify general principles for brain stimulation. The assumption that aphasia is not only the consequence of the focal effect of a brain lesion but arises from remote dysfunctions within associated functional networks ignites the concept for individualized, potentially multifocal therapeutic network modulation.


Assuntos
Afasia/fisiopatologia , Encéfalo/fisiopatologia , Rede Nervosa/fisiopatologia , Afasia/diagnóstico , Afasia/reabilitação , Mapeamento Encefálico , Dominância Cerebral/fisiologia , Neuroimagem Funcional , Humanos , Terapia da Linguagem , Regeneração Nervosa/fisiologia , Testes Neuropsicológicos , Prognóstico , Fonoterapia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Reabilitação do Acidente Vascular Cerebral , Estimulação Transcraniana por Corrente Contínua , Estimulação Magnética Transcraniana
5.
Artigo em Inglês | MEDLINE | ID: mdl-27781339

RESUMO

BACKGROUND: Delayed gastric emptying in diabetic mice and humans is associated with changes in macrophage phenotype and loss of interstitial cells of Cajal (ICC) in the gastric muscle layers. In diabetic mice, classically activated M1 macrophages are associated with delayed gastric emptying, whereas alternatively activated M2 macrophages are associated with normal gastric emptying. This study aimed to determine if secreted factors from M1 macrophages could injure mouse ICC in primary culture. METHODS: Cultures of gastric ICC were treated with conditioned medium (CM) from activated bone marrow-derived macrophages (BMDMs) and the effect of CM was quantified by counting ICC per high-powered field. KEY RESULTS: Bone marrow-derived macrophages were activated to a M1 or M2 phenotype confirmed by qRT-PCR. Conditioned medium from M1 macrophages reduced ICC numbers by 41.1%, whereas M2-CM had no effect as compared to unconditioned, control media. Immunoblot analysis of 40 chemokines/cytokines found 12 that were significantly increased in M1-CM, including tumor necrosis factor alpha (TNF-α). ELISA detected 0.697±0.03 ng mL-1 TNF-α in M1-CM. Recombinant mouse TNF-α reduced Kit expression and ICC numbers in a concentration-dependent manner (EC50 = 0.817 ng mL-1 ). Blocking M1-CM TNF-α with a neutralizing antibody preserved ICC numbers. The caspase inhibitor Z-VAD.fmk partly preserved ICC numbers (cells/field; 6.63±1.04, 9.82±1.80 w/Z-VAD.fmk, n=6, P<.05). CONCLUSIONS & INFERENCES: This work demonstrates that TNF-α secreted from M1 macrophages can result in Kit loss and directly injure ICC in vitro partly through caspase-dependent apoptosis and may play an important role in ICC depletion in diabetic gastroparesis.


Assuntos
Células Intersticiais de Cajal/metabolismo , Macrófagos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Contagem de Células/métodos , Células Cultivadas , Relação Dose-Resposta a Droga , Técnicas de Introdução de Genes , Células Intersticiais de Cajal/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Fator de Necrose Tumoral alfa/farmacologia
6.
Oncogene ; 36(13): 1804-1815, 2017 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-27721407

RESUMO

Mutation of p53 is a frequent genetic lesion in pancreatic cancer being an unmet clinical challenge. Mutants of p53 have lost the tumour-suppressive functions of wild type p53. In addition, p53 mutants exert tumour-promoting functions, qualifying them as important therapeutic targets. Here, we show that the class I histone deacetylases HDAC1 and HDAC2 contribute to maintain the expression of p53 mutants in human and genetically defined murine pancreatic cancer cells. Our data reveal that the inhibition of these HDACs with small molecule HDAC inhibitors (HDACi), as well as the specific genetic elimination of HDAC1 and HDAC2, reduce the expression of mutant p53 mRNA and protein levels. We further show that HDAC1, HDAC2 and MYC directly bind to the TP53 gene and that MYC recruitment drops upon HDAC inhibitor treatment. Therefore, our results illustrate a previously unrecognized class I HDAC-dependent control of the TP53 gene and provide evidence for a contribution of MYC. A combined approach targeting HDAC1/HDAC2 and MYC may present a novel and molecularly defined strategy to target mutant p53 in pancreatic cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Genes p53 , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Animais , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 2/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Humanos , Camundongos , Camundongos Knockout , Mutação , Neoplasias Pancreáticas/patologia , Regiões Promotoras Genéticas , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Mensageiro/genética
7.
Oncogenesis ; 5: e210, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26974205

RESUMO

We previously produced pigs with a latent oncogenic TP53 mutation. Humans with TP53 germline mutations are predisposed to a wide spectrum of early-onset cancers, predominantly breast, brain, adrenal gland cancer, soft tissue sarcomas and osteosarcomas. Loss of p53 function has been observed in >50% of human cancers. Here we demonstrate that porcine mesenchymal stem cells (MSCs) convert to a transformed phenotype after activation of latent oncogenic TP53(R167H) and KRAS(G12D), and overexpression of MYC promotes tumorigenesis. The process mimics key molecular aspects of human sarcomagenesis. Transformed porcine MSCs exhibit genomic instability, with complex karyotypes, and develop into sarcomas on transplantation into immune-deficient mice. In pigs, heterozygous knockout of TP53 was sufficient for spontaneous osteosarcoma development in older animals, whereas homozygous TP53 knockout resulted in multiple large osteosarcomas in 7-8-month-old animals. This is the first report that engineered mutation of an endogenous tumour-suppressor gene leads to invasive cancer in pigs. Unlike in Trp53 mutant mice, osteosarcoma developed in the long bones and skull, closely recapitulating the human disease. These animals thus promise a model for juvenile osteosarcoma, a relatively uncommon but devastating disease.

8.
Oncogene ; 35(29): 3880-6, 2016 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-26592448

RESUMO

Epidermal growth factor receptor (EGFR) signaling has a critical role in oncogenic Kras-driven pancreatic carcinogenesis. However, the downstream targets of this signaling network are largely unknown. We developed a novel model system utilizing murine primary pancreatic ductal epithelial cells (PDECs), genetically engineered to allow time-specific expression of oncogenic Kras(G12D) from the endogenous promoter. We show that primary PDECs are susceptible to Kras(G12D)-driven transformation and form pancreatic ductal adenocarcinomas in vivo after Cdkn2a inactivation. In addition, we demonstrate that activation of Kras(G12D) induces an EGFR signaling loop to drive proliferation. Interestingly, pharmacological inhibition of EGFR fails to decrease Kras(G12D)-activated ERK or PI3K signaling. Instead our data provide novel evidence that EGFR signaling is needed to activate the oncogenic and pro-proliferative transcription factor c-MYC. EGFR and c-MYC have been shown to be essential for pancreatic carcinogenesis. Importantly, our data link both pathways and thereby explain the crucial role of EGFR for Kras(G12D)-driven carcinogenesis in the pancreas.


Assuntos
Células Epiteliais/metabolismo , Receptores ErbB/metabolismo , Ductos Pancreáticos/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células Cultivadas , Células Epiteliais/transplante , Receptores ErbB/genética , Perfilação da Expressão Gênica/métodos , Immunoblotting , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Camundongos Transgênicos , Mutação , Ductos Pancreáticos/citologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética
9.
J Mol Med (Berl) ; 93(12): 1297-309, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26330151

RESUMO

UNLABELLED: Recent studies implicate TRPV4 receptors in visceral pain signaling and intestinal inflammation. Our aim was to evaluate the role of TRPV4 in the control of gastrointestinal (GI) motility and to establish the underlying mechanisms. We used immunohistochemistry and PCR to study TRPV4 expression in the GI tract. The effect of TRPV4 activation on GI motility was characterized using in vitro and in vivo motility assays. Calcium and nitric oxide (NO) imaging were performed to study the intracellular signaling pathways. Finally, TRPV4 expression was examined in the colon of healthy human subjects. We demonstrated that TRPV4 can be found on myenteric neurons of the colon and is co-localized with NO synthase (NOS-1). In vitro, the TRPV4 agonist GSK1016790A reduced colonic contractility and increased inhibitory neurotransmission. In vivo, TRPV4 activation slowed GI motility and reduced stool production in mouse models mimicking pathophysiological conditions. We also showed that TRPV4 activation inhibited GI motility by reducing NO-dependent Ca(2+) release from enteric neurons. In conclusion, TRPV4 is involved in the regulation of GI motility in health and disease. KEY MESSAGES: • Recent studies implicate TRPV4 in pain signaling and intestinal inflammation. • Our aim was to characterize the role of TRPV4 in the control of GI motility. • We found that TRPV4 activation reduced colonic contractility. • Our studies also showed altered TRPV4 mRNA expression in IBS-C patients. • TRPV4 may be a novel pharmacological target in functional GI diseases.


Assuntos
Colo/fisiologia , Motilidade Gastrointestinal/genética , Óxido Nítrico/metabolismo , Transmissão Sináptica/genética , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Colo/efeitos dos fármacos , Colo/fisiopatologia , Modelos Animais de Doenças , Feminino , Motilidade Gastrointestinal/efeitos dos fármacos , Expressão Gênica , Guanilato Ciclase/metabolismo , Humanos , Síndrome do Intestino Irritável/tratamento farmacológico , Síndrome do Intestino Irritável/genética , Síndrome do Intestino Irritável/metabolismo , Síndrome do Intestino Irritável/fisiopatologia , Leucina/análogos & derivados , Leucina/farmacologia , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Modelos Biológicos , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/metabolismo , Plexo Mientérico/metabolismo , Óxido Nítrico Sintase/metabolismo , Sulfonamidas/farmacologia , Canais de Cátion TRPV/antagonistas & inibidores
10.
Ultraschall Med ; 36(5): 487-93, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25607630

RESUMO

PURPOSE: The aim of this study was to evaluate a new method of three-dimensional ultrasound (3D-US) angiography of carotid vessels including 3D-US quantification of internal carotid artery (ICA) stenosis (ICAS). MATERIALS AND METHODS: Two neurologists performed native ultrasound scans of the brain-supplying carotid arteries in 73 probands (including 22 patients with 25 cases of ICAS) using a Toshiba Aplio 500 ultrasound machine equipped with the 3 D application of Curefab CS. Additionally, 25 probands underwent contrast-enhanced magnetic resonance angiography (CE-MRA) of the neck vessels. RESULTS: The mean length of the proximal ICA was 32.1 mm ±â€Š9.8 mm & 31.3 mm ±â€Š9.0 mm (each n = 97). The interrater reliability (intraclass correlation, ICC) was 0.75 ±â€Š0.23 for the common carotid artery (CCA, n = 90) and 0.78 ±â€Š0.21 (n = 92) for the ICA. The intermethod agreement between 3D-US angiography and CE-MRA was 0.67 ±â€Š0.19 (n = 45) & 0.66 ±â€Š0.19 (n = 44) for the CCA and 0.79 ±â€Š0.17 (n = 47) & 0.75 ±â€Š0.19 (n = 46) for the ICA. Quantification of ICAS applying 3D-US in comparison to 2D color-coded duplexsonography (2D-CDS) showed a moderate to good intermethod agreement both by the Bland and Altman analysis and by ICC (0.8 & 0.72; with each p < 0.001). The interrater reliability for quantification of ICAS was 0.79; p < 0.001. CONCLUSION: Native 3D-US angiography of carotid vessels shows good interrater and intermethod agreement in comparison to CE-MRA. Together with a moderate to good intermethod and interrater agreement in the quantification of ICAS, when compared to 2D-CDS, 3D-US angiography is thus a promising complementary imaging technique for carotid artery disease.


Assuntos
Aterosclerose , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Angiografia Cerebral/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Dissecação da Artéria Carótida Interna/diagnóstico por imagem , Espessura Intima-Media Carotídea , Meios de Contraste , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valores de Referência , Reprodutibilidade dos Testes , Adulto Jovem
11.
Br J Cancer ; 111(5): 817-22, 2014 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-24755884

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is almost universally fatal. The annual number of deaths equals the number of newly diagnosed cases, despite maximal treatment. The overall 5-year survival rate of <5% has remained stubbornly unchanged over the last 30 years, despite tremendous efforts in preclinical and clinical science. There is unquestionably an urgent need to further improve our understanding of pancreatic cancer biology, treatment response and relapse, and to identify novel therapeutic targets. Rigorous research in the field has uncovered genetic aberrations that occur during PDAC development and progression. In most cases, PDAC is initiated by oncogenic mutant KRAS, which has been shown to drive pancreatic neoplasia. However, all attempts to target KRAS directly have failed in the clinic and KRAS is widely assumed to be undruggable. This has led to intense efforts to identify druggable critical downstream targets and nodes orchestrated by mutationally activated KRAS. This includes context-specific KRAS effector pathways, synthetic lethal interaction partners and KRAS-driven metabolic changes. Here, we review recent advances in oncogenic KRAS signalling and discuss how these might benefit PDAC treatment in the future.


Assuntos
Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/genética , Proteínas ras/genética , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Humanos
12.
Neurogastroenterol Motil ; 26(4): 470-81, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24460851

RESUMO

BACKGROUND: The endogenous cannabinoid system (ECS) plays a crucial role in multiple physiological processes in the central nervous system and in the periphery. The discovery that selective cannabinoid (CB) receptor agonists exert a potent inhibitory action on gastrointestinal (GI) motility and pain has placed the ECS in the center of attention as a possible target for the treatment of functional GI diseases. However, side effects of CB agonists prompted the search for novel therapeutic targets. Here, the effect of PF-3845, a potent and selective fatty acid amide hydrolase (FAAH) inhibitor in the GI tract was investigated. METHODS: The effect of PF-3845 on GI motility was characterized in vitro and in vivo, using mouse models that mimic physiological and pathophysiological conditions. The antinociceptive action of PF-3845 was evaluated on the basis of behavioral pain models. Endocannabinoid degradation product levels after inhibition of FAAH were quantified using HPLC-MS/MS. KEY RESULTS: PF-3845 significantly inhibited mouse colonic motility in vitro and in vivo. Selective inhibition of FAAH reversed hypermotility and reduced pain in mouse models mimicking functional GI disorders. The effects of PF-3845 were mediated by endogenous CBs and non-CB lipophilic compounds via classical (CB1) and atypical CB receptors. CONCLUSIONS & INFERENCES: These data expand our understanding of the ECS function and provide a novel framework for the development of future potential treatments of functional GI disorders.


Assuntos
Amidoidrolases/antagonistas & inibidores , Analgésicos/farmacologia , Antidiarreicos/farmacologia , Endocanabinoides/metabolismo , Motilidade Gastrointestinal/efeitos dos fármacos , Receptor CB1 de Canabinoide/metabolismo , Amidoidrolases/metabolismo , Animais , Colo/metabolismo , Motilidade Gastrointestinal/fisiologia , Íleo/metabolismo , Masculino , Camundongos , Piperidinas/farmacologia , Piridinas/farmacologia
13.
Brain Res ; 1490: 153-60, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23123705

RESUMO

This study applied an auditory distraction paradigm to investigate involuntary attention effects of unexpected deviations in speech and non-speech sounds on behavior (increase in response time and error rate) and event-related brain potentials (ΔN1/MMN and P3a). Our aim was to systematically compare identical speech sounds with physical vs. linguistic deviations and identical deviations (pitch) with speech vs. non-speech sounds in the same set of healthy volunteers. Sine tones and bi-syllabic pseudo-words were presented in a 2-alternative forced-choice paradigm with occasional phoneme deviants in pseudo-words, pitch deviants in pseudo-words, or pitch deviants in tones. Deviance-related ERP components were elicited in all conditions. Deviance-related negativities (ΔN1/MMN) differed in scalp distribution between phoneme and pitch deviants within phonemes, indicating that auditory deviance-detection partly operates in a deviance-specific manner. P3a as an indicator of attentional orienting was similar in all conditions, and was accompanied by behavioral indicators of distraction. Yet smaller behavioral effects and prolonged relative MMN-P3a latency were observed for pitch deviants within phonemes relative to the other two conditions. This suggests that the similarity and separability of task-relevant and task-irrelevant information is essential for the extent of attentional capture and distraction.


Assuntos
Atenção/fisiologia , Percepção Auditiva/fisiologia , Potenciais Evocados/fisiologia , Percepção da Fala/fisiologia , Estimulação Acústica , Adulto , Análise de Variância , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Luminosa , Discriminação da Altura Tonal , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Fala , Adulto Jovem
14.
Endoscopy ; 44(3): 258-64, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22261747

RESUMO

INTRODUCTION: Bispectral index (BIS) monitoring provides a non-invasive measure of the level of sedation. The purpose of this randomized, single-blind clinical trial was to evaluate whether BIS monitoring of sedation would lead to improved oxygenation and a reduced rate of cardiopulmonary complications during endoscopy. PATIENTS AND METHODS: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) under procedural sedation with a combination of low dose midazolam and propofol were randomly assigned to either standard monitoring of sedation only (BIS-blinded arm) or an open arm in which additional BIS monitoring was available (BIS-open arm). In the BIS-open arm, propofol administration was to be withheld if BIS values were <55. The primary study end point was the mean oxygen saturation per patient. Secondary end points were the rates of cardiopulmonary complications, propofol dose, quality of sedation (patient cooperation as rated by the endoscopist and patient satisfaction), and recovery. RESULTS: A total of 144 patients were enrolled and included in the intention-to-treat analysis. Mean oxygen saturation per patient was 97.7% in the BIS-open arm and 97.6% in the BIS-blinded arm (P=0.71). Total rates of cardiopulmonary complications, single numbers of hypoxemic, bradycardic, and hypotensive events, mean propofol doses, and quality of sedation also showed no statistically significant differences between the groups. However, BIS monitoring did result in faster recovery of patients as reflected by shorter times to eye opening (P=0.001), first verbal response (P=0.02), and leaving the procedure room (P<0.001). CONCLUSIONS: The use of additional BIS monitoring did not lead to improved oxygenation or a reduced rate of cardiopulmonary complications. Recovery times after the procedure were shorter than with standard monitoring alone, but the clinical benefit for daily practice may be limited.


Assuntos
Sedação Consciente , Monitores de Consciência , Hipnóticos e Sedativos/administração & dosagem , Midazolam/administração & dosagem , Oxigênio/sangue , Propofol/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Período de Recuperação da Anestesia , Bradicardia/etiologia , Colangiopancreatografia Retrógrada Endoscópica , Sedação Consciente/efeitos adversos , Humanos , Hipotensão/etiologia , Hipóxia/etiologia , Análise de Intenção de Tratamento , Masculino , Midazolam/farmacologia , Pessoa de Meia-Idade , Cooperação do Paciente , Satisfação do Paciente , Propofol/farmacologia , Método Simples-Cego , Fatores de Tempo
15.
Nervenarzt ; 81(12): 1429-37, 2010 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-21079909

RESUMO

Language is organized in a left-lateralized temporo-frontal network. This network organization enables the brain to reorganize language functions to compensate the deficit after focal brain damage, e.g. ischemic stroke. Clinically, we often observe a high functional dynamic in language performance within the first few days after stroke with a slower improvement in the further course. This suggests that distinct neuronal mechanisms contribute to the functional improvement during the different phases. This article describes how structural and functional MRI methods contribute to understanding loss and recovery of language functions after stroke. In addition, the method of pattern recognition techniques is introduced to demonstrate how language recovery can be predicted from early language fMRI data.


Assuntos
Afasia/diagnóstico , Afasia/fisiopatologia , Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Reconhecimento Automatizado de Padrão/métodos , Algoritmos , Inteligência Artificial , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Oncogene ; 29(19): 2795-806, 2010 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-20190799

RESUMO

Nuclear factor-kappaB (NF-kappaB) and p53 critically determine cancer development and progression. Defining the cross talk between these transcription factors can expand our knowledge on molecular mechanisms of tumorigenesis. Here, we show that induction of replicational stress activates NF-kappaB p65 and triggers its interaction with p53 in the nucleus. Experiments with knockout cells show that p65 and p53 are both required for enhanced NF-kappaB activity during S-phase checkpoint activation involving ataxia-telangiectasia mutated and checkpoint kinase-1. Accordingly, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) also triggers formation of a transcriptionally active complex containing nuclear p65 and p53 on kappaB response elements. Gene expression analyses revealed that, independent of NF-kappaB activation in the cytosol, TNF-induced NF-kappaB-directed gene expression relies on p53. Hence, p53 is unexpectedly necessary for NF-kappaB-mediated gene expression induced by atypical and classical stimuli. Remarkably, data from gain- and loss-of function approaches argue that anti-apoptotic NF-kappaB p65 activity is constitutively evoked by a p53 hot-spot mutant frequently found in tumors. Our observations suggest explanations for the outstanding question why p53 mutations rather than p53 deletions arise in tumors of various origins.


Assuntos
Fator de Transcrição RelA/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem , DNA/genética , DNA/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Hidroxiureia/farmacologia , Camundongos , Mutação , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Fase S/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/genética , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/metabolismo
17.
Gut ; 58(10): 1399-409, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19528037

RESUMO

BACKGROUND: Although histone deacetylase inhibitors (HDACi) are promising cancer therapeutics regulating proliferation, differentiation and apoptosis, molecular pathways engaged by specific HDAC isoenzymes in cancer are ill defined. RESULTS: In this study we demonstrate that HDAC2 is highly expressed in pancreatic ductal adenocarcinoma (PDAC), especially in undifferentiated tumours. We show that HDAC2, but not HDAC1, confers resistance towards the topoisomerase II inhibitor etoposide in PDAC cells. Correspondingly, the class I selective HDACi valproic acid (VPA) synergises with etoposide to induce apoptosis of PDAC cells. Transcriptome profiling of HDAC2-depleted PDAC cells revealed upregulation of the BH3-only protein NOXA. We show that the epigenetically silenced NOXA gene locus is opened after HDAC2 depletion and that NOXA upregulation is sufficient to sensitise PDAC cells towards etoposide-induced apoptosis. CONCLUSIONS: In summary, our data characterise a novel molecular mechanism that links the epigenetic regulator HDAC2 to the regulation of the pro-apoptotic BH3-only protein NOXA in PDAC. Targeting HDAC2 will therefore be a promising strategy to overcome therapeutic resistance of PDAC against chemotherapeutics that induce DNA damage.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Histona Desacetilases/fisiologia , Proteínas de Neoplasias/fisiologia , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Repressoras/fisiologia , Antineoplásicos Fitogênicos/farmacologia , Carcinoma Ductal Pancreático/genética , Linhagem Celular Tumoral , Dano ao DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores Enzimáticos/farmacologia , Etoposídeo/farmacologia , Perfilação da Expressão Gênica , Inativação Gênica/fisiologia , Histona Desacetilase 2 , Histona Desacetilases/genética , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Repressoras/genética , Ácido Valproico/farmacologia
18.
Cancer Gene Ther ; 16(10): 753-63, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19363467

RESUMO

We have earlier described the oncolytic adenovirus vector dl520 that was rendered cancer-specific by deletion of the transactivation domain CR3 of the adenoviral E1A13S protein; this deletion causes antitumor activity in drug-resistant cells displaying nuclear YB-1 expression. We hypothesized that the anticancer activity of dl520 could be further improved by introducing the RGD motif in the fiber knob and by deletion of the adenoviral E1B19K protein (Ad-Delo3-RGD). In this study, the in vitro and in vivo antitumor activity of Ad-Delo3-RGD was investigated focussing on two pancreatic cancer cell lines MiaPaCa-2 and BxPC3 alone and in combination with cytotoxic drugs. Furthermore, luciferin-based bioluminescence imaging was established to study the therapeutic response in vivo. In addition, to confirm the specificity of Ad-Delo3-RGD for YB-1 a tetracycline-inducible anti-YB-1 shRNA-expressing cell variant EPG85-257RDB/tetR/YB-1 was used. This TetON regulatable expression system allows us to measure adenoviral replication by real-time PCR in the absence of YB-1 expression. The results confirmed the YB-1 dependency of Ad-Delo3-RGD and showed that Ad-Delo3-RGD has potent activity against human pancreatic cancer cells in vitro and in vivo, which was augmented by the addition of paclitaxel. However, although high replication capacity was measured in vitro and in vivo, complete tumor regression was not achieved, indicating the need for further improvements to treat pancreatic cancer effectively.


Assuntos
Adenoviridae/fisiologia , Proteínas de Ligação a DNA/biossíntese , Proteínas Nucleares/biossíntese , Terapia Viral Oncolítica/métodos , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/virologia , Adenoviridae/genética , Adenoviridae/metabolismo , Animais , Linhagem Celular Tumoral , Terapia Combinada , Proteínas de Ligação a DNA/genética , Vetores Genéticos/genética , Células HeLa , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Nucleares/genética , Paclitaxel/farmacologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Regiões Promotoras Genéticas , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Replicação Viral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína 1 de Ligação a Y-Box
19.
Neuroimage ; 46(3): 642-51, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19285561

RESUMO

The purpose of this study is the classification of high angular resolution diffusion imaging (HARDI) in vivo data using a model-free approach. This is achieved by using a Support Vector Machine (SVM) algorithm taken from the field of supervised statistical learning. Six classes of image components are determined: grey matter, parallel neuronal fibre bundles in white matter, crossing neuronal fibre bundles in white matter, partial volume between white and grey matter, background noise and cerebrospinal fluid. The SVM requires properties derived from the data as input, the so called feature vector, which should be rotation invariant. For our application we derive such a description from the spherical harmonic decomposition of the HARDI signal. With this information the SVM is trained in order to find the function for separating the classes. The SVM is systematically tested with simulated data and then applied to six in vivo data sets. This new approach is data-driven and enables fully automatic HARDI data segmentation without employing a T1 MPRAGE scan and subjective expert intervention. This was demonstrated on five test in vivo data sets giving robust results. The segmentation results could be used as a priori knowledge for increasing the performance of fibre tracking as well as for other clinical and diagnostic applications of diffusion weighted imaging (DWI).


Assuntos
Algoritmos , Inteligência Artificial , Encéfalo/anatomia & histologia , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Armazenamento e Recuperação da Informação/métodos , Fibras Nervosas Mielinizadas/ultraestrutura , Neurônios/citologia , Reconhecimento Automatizado de Padrão/métodos , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Proc Natl Acad Sci U S A ; 106(9): 3354-9, 2009 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-19208810

RESUMO

Obesity is associated with increased risk for developing pancreatic cancer, and it is suggested that insulin resistance provides the missing link. Here we demonstrate that under the context of genetic susceptibility, a high fat diet (HFD) predisposes mice with oncogenic K-ras activation to accelerated pancreatic intraepithelial neoplasm (PanIN) development. Tumor promotion is closely associated with increased inflammation and abrogation of TNFR1 signaling significantly blocks this process underlining a central role for TNFalpha in obesity-mediated enhancement of PanIN lesions. Interestingly, however, despite increased TNFalpha levels, mice remain insulin sensitive. We show that, while aggravating tumor promotion, a HFD exerts dramatic changes in energy metabolism through enhancement of pancreatic exocrine insufficiency, metabolic rates, and expression of genes involved in mitochondrial fatty acid (FA) beta-oxidation that collectively contribute to improved glucose tolerance in these mice. While on one hand these findings provide significant evidence that obesity is linked to tumor promotion in the pancreas, on the other it suggests alterations in inflammatory responses and bioenergetic pathways as the potential underlying cause.


Assuntos
Ácidos Graxos/metabolismo , Mitocôndrias/metabolismo , Obesidade/metabolismo , Neoplasias Pancreáticas/metabolismo , Ração Animal , Animais , Progressão da Doença , Insuficiência Pancreática Exócrina/induzido quimicamente , Insuficiência Pancreática Exócrina/metabolismo , Insuficiência Pancreática Exócrina/patologia , Ácidos Graxos/farmacologia , Inflamação/genética , Inflamação/metabolismo , Resistência à Insulina , Camundongos , Mitocôndrias/efeitos dos fármacos , Oxirredução , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fatores de Tempo , Proteínas ras/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...