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1.
Artigo em Inglês | MEDLINE | ID: mdl-25571189

RESUMO

Robotic technologies provide objective, highly reliable tools for assessment of brain function following stroke. KINARM is an exoskeleton device that quantifies sensorimotor brain function using a visually guided reaching task among many other behavioral tasks. As further tasks are developed to more broadly assess different aspects of behavior using the robot, techniques and approaches are required to reduce the time it takes to complete each task. The present study investigates how the value of robot-measured parameters changes under alternative schemes that significantly reduce assessment time compared to the current assessment protocol for the visually guided reaching task. Results of the study are validated by addressing an important diagnostic question using an SVM classifier, showing that the alternative schemes provide nearly identical performance in terms of classification sensitivity, specificity and accuracy.


Assuntos
Robótica , Acidente Vascular Cerebral/fisiopatologia , Humanos , Córtex Sensório-Motor/fisiologia , Máquina de Vetores de Suporte
2.
Cancer Biol Ther ; 7(5): 786-93, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18756624

RESUMO

Malignant glioma continues to be a major target for gene therapy and virotherapy due to its aggressive growth and the current lack of effective treatment. However, these approaches have been hampered by inefficient infection of glioma cells by viral vectors,particularly vectors derived from serotype 5 adenoviruses (Ad5). This results from limited cell surface expression of the primary adenovirus receptor, coxsackie-adenovirus-receptor (CAR), on tumor cells. To circumvent this problem, Ad fiber pseudotyping,the genetic replacement of either the entire fiber or fiber knob domain with its structural counterpart from another human Ad serotype that recognizes a cellular receptor other than CAR, has been shown to enhance Ad infectivity in a variety of tumor types,including human glioma. Here, we have extended the paradigm of genetic pseudotyping to include fiber domains from non-human or"xenotype" Ads for infectivity enhancement of human glioma cell populations. In this study, we evaluated the gene transfer efficiency of a panel of Ad vectors which express one of five different "xenotype"fiber knob domains, including those derived from murine,ovine, porcine and canine species, in both human glioma cell lines as well as primary glioma tumor cells from patients. Adenovirus vectors displaying either canine Ad or porcine Ad fiber elements had the highest gene transfer to both glioma cell lines and primary tumor cells. The correlation between the viral infectivity of modified adenovirus vectors and expression of human CAR and CD46(an adenovirus type B receptor) on the surfaces of tumor cells was also analyzed. Taken together, human adenovirus vectors modified with "xenotype" fiber elements could be excellent candidates to target human glioma.


Assuntos
Adenoviridae/metabolismo , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Animais , Linhagem Celular Tumoral , Receptor Constitutivo de Androstano , Citomegalovirus/metabolismo , Técnicas de Transferência de Genes , Terapia Genética/métodos , Vetores Genéticos , Humanos , Proteína Cofatora de Membrana/metabolismo , Camundongos , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Vírus/metabolismo
3.
Qual Saf Health Care ; 17(4): 244-8, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18678719

RESUMO

OBJECTIVE: Studies suggest that there is a need to improve the way we deliver care at the end of life. Based on recommendations from end-of-life experts, metrics were identified to measure the quality of dying in Dunedin Hospital. DESIGN: A retrospective observational study was performed to assess the care provided to patients who died in the hospital in 2003. SETTING: Dunedin Hospital is a 350-bed tertiary care teaching hospital located in the South Island of New Zealand. SUBJECTS AND METHOD: Medical records of 200 consecutive decedents were reviewed to evaluate communication, interventions, and symptom control during their terminal hospitalisation. RESULTS: Mean hospital length-of-stay was 8 days; 38 patients (19%) died following an ICU admission. There was documentation of end-of-life discussion with either the patient or the family in 164 patients (82%). 74% had a DNR order. Pain status was documented in 140 patients (70%); 134 of these patients were pain-free. CONCLUSION: Overall, the results suggest that the ideals in end-of-life care pertaining to pain control, communication and avoidance of unnecessary interventions were achieved in a majority of the decedents during the study period. The socialised healthcare system, the availability of resources, societal expectations and a lack of a litigious environment are theorised to positively influence end-of-life care delivery in New Zealand.


Assuntos
Hospitais de Ensino/normas , Qualidade da Assistência à Saúde/normas , Assistência Terminal/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Feminino , Relações Hospital-Paciente , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Observação , Estudos Retrospectivos
4.
Ulster Med J ; 75(1): 65-71, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16457407

RESUMO

In recent years, many babies who die of Sudden Unexpected Death in Infancy (SUDI) in Northern Ireland are found dead in bed--i.e. co-sleeping--with an adult. In order to assess its frequency autopsy reports between April 1996 and August 2001 were reviewed and linked to temporal factors. The day and month of death, and the place where the baby was found were compared to a reference population of infant deaths between one week of age and the second birthday. Although the rate of SUDI was lower than the UK average, 43 cases of SUDI were identified, and two additional deaths with virtually identical autopsy findings that were attributed to asphyxia caused by suffocation due to overlaying. Thirty-two of the 45 (71%) were less than four months of age. In 30 of the 45 cases (67%) the history stated that the baby was bed sharing with others; 19 died sleeping in an adult bed, and 11 on a sofa or armchair. In 16 of the 30 (53%) there were at least two other people sharing the sleeping surface, and in one case, three. SUDI was twice as frequent at weekends (found dead Saturday-Monday mornings) compared to weekdays (p<0.02), and significantly more common compared to reference deaths (p<0.002). Co-sleeping deaths were also more frequent at weekends. Almost half of all SUDI (49%) occurred in the summer months--more than twice the frequency of reference deaths. While sharing a place of sleep per se may not increase the risk of death, our findings may be linked to factors such as habitual smoking, consumption of alcohol or illicit drugs as reported in case-control studies. In advising parents on safer childcare practices, health professionals must be knowledgeable of current research and when, for example, giving advice on co-sleeping this needs to be person-specific cognisant of the risks within a household. New and better means of targeting such information needs to be researched if those with higher risk life-styles are to be positively influenced.


Assuntos
Morte Súbita do Lactente/epidemiologia , Leitos , Feminino , Humanos , Lactente , Irlanda/epidemiologia , Masculino , Estações do Ano , Sono , Fatores de Tempo
5.
Cancer Gene Ther ; 13(9): 830-44, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16439993

RESUMO

Cancer gene therapy approaches will derive considerable benefit from adenovirus (Ad) vectors capable of self-directed localization to neoplastic disease or immunomodulatory targets in vivo. The ablation of native Ad tropism coupled with active targeting modalities has demonstrated that innate gene delivery efficiency may be retained while circumventing Ad dependence on its primary cellular receptor, the coxsackie and Ad receptor. Herein, we describe advances in Ad targeting that are predicated on a fundamental understanding of vector/cell interplay. Further, we propose strategies by which existing paradigms, such as nanotechnology, may be combined with Ad vectors to form advanced delivery vehicles with multiple functions.


Assuntos
Adenoviridae/genética , Marcação de Genes/métodos , Terapia Genética/métodos , Vetores Genéticos/genética , Neoplasias/terapia , Transdução Genética/métodos , Humanos , Nanotecnologia/tendências , Neoplasias/genética , Receptores Virais/metabolismo
6.
Gene Ther ; 13(1): 88-94, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16107860

RESUMO

Adenovirus (Ad) vectors are of utility for many therapeutic applications. Strategies have been developed to alter adenoviral tropism to achieve a cell-specific gene delivery capacity employing fiber modifications allowing genetic incorporation of targeting motifs. In this regard, single chain antibodies (scFv) represent potentially useful agents to achieve targeted gene transfer. However, the distinct biosynthetic pathways that scFv and Ad capsid proteins are normally routed through have thus far been problematic with respect to scFv incorporation into the Ad capsid. Utilization of stable scFv, which also maintain correct folding and thus functionality under intracellular reducing conditions, could overcome this restriction. We genetically incorporated a stable scFv into a de-knobbed, fibritin-foldon trimerized Ad fiber and demonstrated selective targeting to the cognate epitope expressed on the membrane surface of cells. We have shown that the scFv employed in this study retains functionality and that stabilizing the targeting molecule, per se, is critical to allow retention of antigen recognition in the adenovirus capsid-incorporated context.


Assuntos
Adenoviridae/genética , Proteínas Precoces de Adenovirus/genética , DNA de Cadeia Simples/administração & dosagem , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Região Variável de Imunoglobulina/genética , Adenoviridae/imunologia , Proteínas Precoces de Adenovirus/imunologia , Reações Antígeno-Anticorpo , Linhagem Celular , Epitopos , Expressão Gênica , Marcação de Genes , Engenharia Genética , Vetores Genéticos/genética , Humanos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Transdução Genética/métodos
7.
Gene Ther ; 13(5): 389-99, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16292351

RESUMO

The full realization of conditionally replicative adenoviruses (CRAds) for cancer therapy has been hampered by the limited knowledge of CRAd function in vivo and particularly in an immunocompetent host. To address this issue, we previously proposed a canine adenovirus type 2 (CAV2)-based CRAd for clinical evaluation in canine patients with osteosarcoma (OS). In this study, we evaluated infectivity-enhancement strategies to establish the foundation for designing a potent CAV2 CRAd with effective transduction capacity in dog osteosarcoma cells. The results indicate that the native CAV2 fiber-knob can mediate increased binding, and consequently gene transfer, in both canine osteosarcoma immortalized and primary cell lines relative to previously reported Ad5 infectivity-enhancement strategies. Gene delivery was further enhanced by incorporating a polylysine polypeptide onto the carboxy terminus of the CAV2 knob. This vector demonstrated improved gene delivery in osteosarcoma xenograft tumors. These data provide the rationale for generation of infectivity-enhanced syngeneic CAV2 CRAds for clinical evaluation in a dog osteosarcoma model.


Assuntos
Doenças do Cão/terapia , Terapia Genética/métodos , Terapia Viral Oncolítica/métodos , Osteossarcoma/terapia , Transdução Genética/métodos , Adenoviridae/genética , Infecções por Adenoviridae/virologia , Animais , Caveolina 2/genética , Linhagem Celular Tumoral , Doenças do Cão/virologia , Cães , Citometria de Fluxo , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Humanos , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Modelos Animais , Transplante de Neoplasias , Osteossarcoma/veterinária , Osteossarcoma/virologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Transplante Heterólogo , Replicação Viral
8.
Gene Ther ; 12(23): 1696-706, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16034451

RESUMO

The development of novel therapeutic strategies is imperative for the treatment of advanced cancers like ovarian cancer and glioma, which are resistant to most traditional treatment modalities. In this regard, adenoviral (Ad) cancer gene therapy is a promising approach. However, the gene delivery efficiency of human serotype 5 recombinant adenoviruses (Ad5) in cancer gene therapy clinical trials to date has been limited, mainly due to the paucity of the primary Ad5 receptor, the coxsackie and adenovirus receptor (CAR), on human cancer cells. To circumvent CAR deficiency, Ad5 vectors have been retargeted by creating chimeric fibers possessing the knob domains of alternate human Ad serotypes. Recently, more radical modifications based on 'xenotype' knob switching with non-human adenovirus have been exploited. Herein, we present the characterization of a novel vector derived from a recombinant Ad5 vector containing the canine adenovirus serotype 1 (CAV-1) knob (Ad5Luc1-CK1), the tropism of which has not been previously described. We compared the function of this vector with our other chimeric viruses displaying the CAV-2 knob (Ad5Luc1-CK2) and Ad3 knob (Ad5/3Luc1). Our data demonstrate that the CAV-1 knob can alter Ad5 tropism through the use of a CAR-independent entry pathway distinct from that of both Ad5Luc1-CK2 and Ad5/3-Luc1. In fact, the gene transfer efficiency of this novel vector in ovarian cancer cell lines, and more importantly in patient ovarian cancer primary tissue slice samples, was superior relative to all other vectors applied in this study. Thus, CAV-1 knob xenotype gene transfer represents a viable means to achieve enhanced transduction of low-CAR tumors.


Assuntos
Adenovirus Caninos/genética , Proteínas do Capsídeo/genética , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Neoplasias/terapia , Ligação Competitiva , Linhagem Celular Tumoral , DNA Viral , Feminino , Expressão Gênica , Engenharia Genética , Vetores Genéticos/genética , Humanos , Fígado/metabolismo , Fígado/virologia , Neoplasias Ovarianas/terapia , Transdução Genética/métodos
9.
Ulster Med J ; 74(1): 22-8, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-16022129

RESUMO

Injuries in childhood represent a major public health concern. North and West Belfast is an area in which a high rate of emergency department attendance due to injury has been observed, and in which social deprivation is widespread. We carried out a cross sectional survey of 479 injuries in children aged 0-12 years presenting to four emergency departments serving North and West Belfast. Injury rates were compared between the most deprived and least deprived areas, selected on the basis of Noble Economic Deprivation scores. A significant correlation between economic deprivation and injury rate was demonstrated (r = 2.14, p < or = 0.001). Children living within the most deprived areas were particularly likely to be involved in road traffic accidents (relative risk RR = 3.25, p = 0.002). We conclude that children living within the most deprived areas of North and West Belfast are at greater risk of injury than those in less deprived areas. Specific causes of injury, for example burns and scalds, high falls, and motor vehicle accidents are particularly associated with deprivation. Targeting should be taken into account when injury prevention strategies are being developed.


Assuntos
Carência Psicossocial , Ferimentos e Lesões/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Serviço Hospitalar de Emergência , Humanos , Lactente , Recém-Nascido , Irlanda/epidemiologia , Meio Social , Fatores Socioeconômicos
10.
Gene Ther ; 12(13): 1042-8, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15789059

RESUMO

Targeted therapies directed to tumor-associated antigens are being investigated for the treatment of cancer. However, there are few suitable animal models for testing the ability to target these tumor markers. Therefore, we have exploited mice transgenic for the human coxsackie and adenovirus receptor (hCAR) to establish a new model for transient expression of human tumor-associated antigens in the pulmonary vasculature. Systemic administration of Ad in hCAR mice resulted in an increase in transgene expression in the lungs compared to wild-type mice, as determined using a luciferase reporter gene. To reduce transgene expression in the liver, the predominant organ of ectopic Ad localization and transgene expression following systemic administration, we utilized the endothelial-specific flt-1 promoter, which resulted in a further increased lung-to-liver ratio of luciferase expression. Administration of an adenoviral vector encoding the tumor-associated antigen carcinoembryonic antigen (CEA) under transcriptional control of the flt-1 promoter resulted in selective expression of this antigen in the pulmonary vasculature of hCAR mice. Feasibility of targeting to expressed CEA was subsequently demonstrated using adenoviral vectors preincubated with a bifunctional adapter molecule recognizing this tumor-associated antigen, thus demonstrating utility of this transient transgenic animal model.


Assuntos
Adenoviridae/genética , Antígeno Carcinoembrionário/genética , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Circulação Pulmonar/fisiologia , Animais , Proteínas da Matriz Extracelular , Expressão Gênica , Marcação de Genes/métodos , Vetores Genéticos/genética , Imuno-Histoquímica/métodos , Fígado/metabolismo , Luciferases/genética , Camundongos , Camundongos Transgênicos , Cadeias Pesadas de Miosina , Miosina não Muscular Tipo IIB , Regiões Promotoras Genéticas , Proteínas/genética , Receptores Virais/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular
11.
Gene Ther ; 12(2): 187-93, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15526007

RESUMO

Adenoviruses (Ads) are efficient gene transfer vehicles, but Ad-mediated gene therapy for ovarian cancer remains limited in vivo by inefficient and nonspecific gene transfer. Mesothelin (MSLN), a cell surface glycoprotein, is overexpressed in ovarian cancer but not in normal tissues except mesothelial cells. Therefore, MSLN is an attractive candidate for transcriptional and transductional targeting in the context of ovarian cancer gene therapy. We evaluated the expression of MSLN mRNA and MSLN surface protein in ovarian cancer cells. Ads containing the MSLN promoter driving reporter gene expression were created and tested in ovarian cancer cell lines and purified ovarian cancer cells isolated from patients. To evaluate transductional targeting, we used an Ad vector containing an Fc-binding domain within the fiber protein, which served as a docking domain for binding with anti-MSLN immunoglobulins. Both RT-PCR and flow cytometry revealed high MSLN gene and protein expression in ovarian cancer cells. The MSLN promoter was activated in ovarian cancer cells, but showed significantly reduced activity in normal control cells. Transductional targeting of Ads via anti-MSLN antibody increased transgene expression in ovarian cancer cells. This report describes the use of MSLN for transcriptional as well as transductional targeting strategies for ovarian cancer gene therapy.


Assuntos
Terapia Genética/métodos , Glicoproteínas de Membrana/genética , Neoplasias Ovarianas/terapia , Regiões Promotoras Genéticas , Adenoviridae/genética , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Proteínas Ligadas por GPI , Expressão Gênica , Marcação de Genes , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Humanos , Glicoproteínas de Membrana/análise , Mesotelina , RNA Mensageiro/análise , Transdução Genética/métodos , Células Tumorais Cultivadas
12.
Curr Gene Ther ; 4(1): 1-14, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15032610

RESUMO

Adenovirus (Ad) targeting is a novel approach for the design and administration of therapeutic agents wherein the agent is rationally designed to localize and restrict transgene expression to the site of disease in a self-directed manner, usually via exploitation of unique biophysical and genetic properties specific to the diseased tissue. The ablation of promiscuous native Ad tropism coupled with active targeting modalities has demonstrated that innate gene delivery efficiency may be retained while circumventing Ad dependence on its primary cellular receptor, the coxsackie and adenovirus receptor (CAR), to achieve CAR-independent vector tropism. Herein, we describe advances in Ad targeting that are predicated not only on fundamental understanding of vector/cell interplay, but also on the specific transcriptional profiles of target tissues. Further, targeting is discussed in the context of improving the safety and efficacy of clinical approaches utilizing adenoviral vectors and replication competent oncolytic agents. In summary, existing results suggest a critical linkage between targeted agents and increases in therapeutic utility.


Assuntos
Adenoviridae/genética , Terapia Genética/métodos , Vetores Genéticos , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Proteínas de Ligação a DNA/genética , Proteína 1 de Resposta de Crescimento Precoce , Vetores Genéticos/genética , Humanos , Proteínas Imediatamente Precoces/genética , Neoplasias/terapia , Regiões Promotoras Genéticas , Receptores Virais/genética , Fatores de Transcrição/genética , Transcrição Gênica , Transdução Genética
13.
Bioinformatics ; 18 Suppl 1: S111-9, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12169538

RESUMO

MOTIVATION: With the increasing number of gene expression databases, the need for more powerful analysis and visualization tools is growing. Many techniques have successfully been applied to unravel latent similarities among genes and/or experiments. Most of the current systems for microarray data analysis use statistical methods, hierarchical clustering, self-organizing maps, support vector machines, or k-means clustering to organize genes or experiments into 'meaningful' groups. Without prior explicit bias almost all of these clustering methods applied to gene expression data not only produce different results, but may also produce clusters with little or no biological relevance. Of these methods, agglomerative hierarchical clustering has been the most widely applied, although many limitations have been identified. RESULTS: Starting with a systematic comparison of the underlying theories behind clustering approaches, we have devised a technique that combines tree-structured vector quantization and partitive k-means clustering (BTSVQ). This hybrid technique has revealed clinically relevant clusters in three large publicly available data sets. In contrast to existing systems, our approach is less sensitive to data preprocessing and data normalization. In addition, the clustering results produced by the technique have strong similarities to those of self-organizing maps (SOMs). We discuss the advantages and the mathematical reasoning behind our approach.


Assuntos
Algoritmos , Análise por Conglomerados , Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Software , Interface Usuário-Computador , Carcinoma Pulmonar de Células não Pequenas/genética , Gráficos por Computador , Humanos , Neoplasias Pulmonares/genética , Modelos Genéticos , Modelos Estatísticos
15.
Int J Clin Pract ; 56(1): 21-5, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11833551

RESUMO

We describe the development of an innovative, nurse-led chronic pain clinic in primary care. Benefit of the structured intervention was seen in terms of overall patient pain (as measured by the short form McGill-Melzack pain scale) with no overall impact on drug costs. A significant proportion (54%) of patients taking non-steroidal anti-inflammatory drugs were deemed to be at risk of gastropathy and in need of gastroprotection as defined by the clinic protocol. Areas worthy of further study are discussed.


Assuntos
Enfermeiros Administradores , Clínicas de Dor/organização & administração , Dor/enfermagem , Atenção Primária à Saúde/organização & administração , Desenvolvimento de Programas/métodos , Atitude do Pessoal de Saúde , Humanos , Irlanda do Norte , Satisfação do Paciente , Projetos Piloto
17.
Neurochem Res ; 26(6): 647-59, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11519724

RESUMO

Signal transduction pathways that mediate neuronal commitment to apoptosis involve the nuclear factor kappa B (NF-kappaB) transcription factor. The bcl-x gene is a member of the bcl-2 family of genes that regulate apoptosis, and gives rise to two proteins, Bcl-XL and Bcl-XS, via alternative mRNA splicing. BCl-XL protein, like Bcl-2, is a dominant inhibitor of apoptotic cell death, whereas Bcl-XS promotes apoptosis. While there is high expression of Bcl-XL in the developing and adult brain, few transcriptional control elements have been identified in the bcl-x promoter. There are two functional nuclear factor-kappa B (NF-kappaB) DNA binding sites clustered upstream of the brain-specific transcription start site in the upstream promoter region of murine bcl-x. Recombinant NF-kappaB proteins bind to these sites. Also NF-kappaB overexpression, coupled with bcl-x promoter/reporter assays using a series of murine bcl-x promoter and deletion mutants, has identified the downstream 1.1kb of the bcl-x promoter as necessary for basal promoter activity and induction by NF-kappaB in support of the hypothesis that NF-kappaB can act to enhance BCl-XL expression via highly selective interactions with the bcl-x promoter, where NF-kappaB binding and promoter activation are dependent on specific DNA binding site sequences and NF-kappaB protein dimer composition. Hypoxia induces apoptosis in the hippocampus where the NF-kappaB dimers c-Rel/p50 and p50/pS0 bind to the bcl-x promoter NF-kappaB site.


Assuntos
Encéfalo/fisiopatologia , Hipóxia/genética , Hipóxia/fisiopatologia , NF-kappa B/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transcrição Gênica/fisiologia , Animais , Proteína bcl-X
19.
J Neurosci Res ; 64(3): 223-34, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11319766

RESUMO

Cell death often occurs after hypoxic/ischemic injury to the central nervous system. Changes in levels of the anti-apoptotic Bcl-X(L) protein may be a determining factor in hypoxia-induced neuronal apoptosis. The transcription factor NF-kappa B regulates bcl-x gene expression. In this study, we examined the role of NF-kappa B in the regulation of bcl-x in hypoxia-induced cell death. Rat hippocampus and basal forebrain tissues were collected at different time points after hypoxia (7%O(2), 93% N(2) for 10 or 20 min). We found that 1) hypoxia induced apoptosis in the hippocampus and basal forebrain; 2) the NF-kappa B dimers c-Rel/p50 and p50/p50 bound to the bcl-x promoter NF-kappa B sequence (CS4) in the hippocampus, but only p50/p50 bound to the CS4 sequence in the basal forebrain and hypoxia-induced differential binding patterns of c-Rel/p50 and p50/p50 correlated with the bcl-x expression pattern in the hippocampus; 3) the hypoxia-induced patterns of binding of c-Rel/p50 to the bcl-x promoter CS4 sequence were different from those to the IgG-kappa B enhancer sequence, whereas those of p50/p50 were similar to both sequences; 4) nuclear protein levels of c-Rel, but not p50, correlated with the c-Rel/p50 DNA binding patterns to the bcl-x CS4 site; and 5) there were differential responses to hypoxia among the different NF-kappa B protein subunits. These results suggest that there is a tissue-specific regulation of bcl-x gene expression by NF-kappa B in hypoxia-induced cell death in the hippocampus. The absence of these regulating features in the basal forebrain may account for the early appearance of apoptosis in response to hypoxia as compared with that in hippocampus.


Assuntos
Hipocampo/metabolismo , Hipóxia Encefálica/metabolismo , NF-kappa B/metabolismo , Prosencéfalo/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Animais , Apoptose/fisiologia , Masculino , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Transcrição Gênica/fisiologia , Proteína bcl-X
20.
Neurochem Res ; 25(9-10): 1373-83, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11059808

RESUMO

Both acute and chronic insults to the nervous system can result in changes in homeostasis that result in cell death or recovery processes that alter function. The signaling mechanisms for this broad spectrum of events that impair neurological function span the gamut from abrupt injury to the slow onset of neurodegenerative diseases in extreme aging. A common element in all of these events is the triggering of signal cascades that determine cellular commitment to apoptosis as a ameliorative alternative to inflammatory necrosis. Key in these cascades is the activation of the caspase and Bcl-family of proteins by the NF-kappaB transcription factor. Here we consider aspects of specificity of activation as a result of the differential expression of NF-kappaB proteins and their regulation of selective genes as a result of binding to select DNA consensus sequences out of the 64 different combinations that constitute the NF-kappaB DNA binding consensus sequence.


Assuntos
Apoptose , Encéfalo/fisiologia , Morte Celular , Sistema Nervoso Central/fisiologia , Doenças Neurodegenerativas/fisiopatologia , Transcrição Gênica , Envelhecimento , Animais , Encéfalo/patologia , Encéfalo/fisiopatologia , Sistema Nervoso Central/citologia , Regulação da Expressão Gênica , Homeostase , Humanos , NF-kappa B/metabolismo , Doenças Neurodegenerativas/patologia , Transdução de Sinais
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