RESUMO
OBJECTIVE: Early mobilisation is in integral component of postoperative recovery following complex surgical procedures such as oesophageal cancer resections, however evidence to guide early mobilisation protocols in critical care settings is limited. Furthermore, little is known about actual mobilisation levels postoperatively. This study quantified postoperative mobilisation post- oesophagectomy and investigated barriers to mobility. DESIGN: Prospective observational study. SETTING: Postoperative critical care setting in a tertiary care referral centre for oesophagectomy. PARTICIPANTS: Thirty participants (mean age 65 (SD 7) years, n=19 males) scheduled for oesophagectomy. MAIN OUTCOME MEASURES: The primary outcome, postoperative physical activity, was measured objectively using the Actigraph GT3X+. Medical records were examined for a range of outcomes including medical status, pain scores and physiotherapy comments to identify factors which may have influenced mobility. RESULTS: During postoperative day (POD) 1-5, participants spent the majority of time (>96%) sedentary. Participation in light intensity activity was low but did increase daily from a median of 12 (IQR 19) minutes/day on POD1 to a median of 53 (IQR 73.25) minutes/day on POD5 p<0.001), with a corresponding increase in daily step count. Haemodynamic instability was the most common reason reported by physiotherapists for either not attempting mobility or limiting postoperative mobilisation levels. CONCLUSIONS: These data demonstrate that despite daily physiotherapy, there are multiple challenges to postoperative mobilisation. Haemodynamic instability, likely related to thoracic epidurals, was the key limitation to early mobilisation. Goal-directed mobilisation in collaboration with the multidisciplinary team may play a considerable role in overcoming modifiable barriers to postoperative mobilisation.
Assuntos
Deambulação Precoce/métodos , Neoplasias Esofágicas/cirurgia , Esofagectomia/reabilitação , Modalidades de Fisioterapia , Actigrafia , Idoso , Exercício Físico , Feminino , Humanos , Tempo de Internação , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Fatores de RiscoRESUMO
We tested whether the T helper (Th) type 2 (Th2) cell agonist and allergenic ligand IL-33 was associated with eosinophilic esophagitis (EoE) development in a pediatric cohort and whether IL-33 protein could induce disease symptoms in mice. Biopsies from EoE patients or controls were used to measure IL-33 mRNA and protein expression. Increased expression of IL-33 mRNA was found in the esophageal mucosa in EoE. IL-33 protein was detected in cells negative for CD45, mast cells, and epithelial cell markers near blood vessels. Circulating levels of IL-33 were not increased. The time course for IL-33 gene expression was quantified in an established Aspergillus fumigatus allergen mouse model of EoE. Because IL-33 induction was transient in this model and chronicity of IL-33 expression has been demonstrated in humans, naive mice were treated with recombinant IL-33 for 1 wk and esophageal pathology was evaluated. IL-33 application produced changes consistent with phenotypically early EoE, including transmural eosinophilia, mucosal hyperproliferation, and upregulation of eosinophilic genes and chemokines. Th2 cytokines, including IL-13, along with innate lymphoid cell group 2, Th1/17, and M2 macrophage marker genes, were increased after IL-33 application. IL-33-induced eosinophilia was ablated in IL-13 null mice. In addition, IL-33 induced a profound inhibition of the regulatory T cell gene signature. We conclude that IL-33 gene expression is associated with pediatric EoE development and that application of recombinant protein in mice phenocopies the early clinical phase of the human disease in an IL-13-dependent manner. IL-33 inhibition of esophageal regulatory T cell function may induce loss of antigenic tolerance, thereby providing a mechanistic rationale for EoE development.
Assuntos
Esofagite Eosinofílica/induzido quimicamente , Esofagite Eosinofílica/metabolismo , Esôfago/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-33/metabolismo , Imunidade Adaptativa , Adolescente , Animais , Aspergillus fumigatus/patogenicidade , Biópsia , Estudos de Casos e Controles , Proliferação de Células , Quimiocina CCL26 , Quimiocinas CC/metabolismo , Criança , Pré-Escolar , Modelos Animais de Doenças , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Esofagite Eosinofílica/genética , Esofagite Eosinofílica/imunologia , Esofagite Eosinofílica/microbiologia , Esofagite Eosinofílica/patologia , Esôfago/imunologia , Esôfago/microbiologia , Esôfago/patologia , Humanos , Tolerância Imunológica , Imunidade Inata , Interleucina-13/deficiência , Interleucina-13/genética , Interleucina-33/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Knockout , Fenótipo , RNA Mensageiro/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fatores de Tempo , Regulação para CimaRESUMO
Between March 2010 and November 2013 eight laboratory-confirmed cases of serogroup B, invasive meningococcal disease (IMD) were identified in an extended Irish Traveller family across three Health Service Executive (HSE) areas of Ireland. Cases were aged between 5 and 46 months, and were either a cousin or sibling of another case. All eight cases survived. Chemoprophylaxis was given to relevant nuclear family members and close contacts on each occasion, but failed to prevent further cases. Neisseria meningitidis isolates from six cases were highly related, belonging to the ST-41/44 clonal complex, and shared the porA designation 72,4. In November 2013, the outbreak control team recommended that directly observed ciprofloxacin chemoprophylaxis be administered simultaneously to the extended family, and that the four component meningococcal B (4CMenB) vaccine be administered to family members aged 2 months to 23 years inclusive and relevant close contacts of the eighth case. Subsequently these recommendations were implemented at three regional clinics. Additionally pharyngeal swabs (n=112) were collected to assess carriage rates of N. meningitidis in this extended family. Pharyngeal carriage of N. meningitidis was detected in 15 (13%) family members. From the epidemiological investigation and carriage study overcrowding was the most likely risk factor identified in this outbreak. To date, the combination of directly observed ciprofloxacin chemoprophylaxis and use of 4CMenB vaccine have controlled the outbreak with no further cases diagnosed.
Assuntos
Área Programática de Saúde , Ciprofloxacina/administração & dosagem , Surtos de Doenças/prevenção & controle , Família , Infecções Meningocócicas/epidemiologia , Neisseria meningitidis Sorogrupo B/isolamento & purificação , Viagem , Adolescente , Adulto , Quimioprevenção , Criança , Pré-Escolar , Busca de Comunicante , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lactente , Recém-Nascido , Irlanda/epidemiologia , Masculino , Infecções Meningocócicas/tratamento farmacológico , Testes de Sensibilidade Microbiana , Neisseria meningitidis Sorogrupo B/efeitos dos fármacos , Neisseria meningitidis Sorogrupo B/genética , Reação em Cadeia da Polimerase , Vigilância da População , Fatores de Risco , Resultado do Tratamento , Adulto JovemRESUMO
Converging evidence suggests bioenergetic abnormalities in bipolar disorder (BD). In the brain, phosphocreatine (PCr) acts a reservoir of high-energy phosphate (HEP) bonds, and creatine kinases (CK) catalyze the transfer of HEP from adenosine triphosphate (ATP) to PCr and from PCr back to ATP, at times of increased need. This study examined the activity of this mechanism in BD by measuring the levels of HEP molecules during a stimulus paradigm that increased local energy demand. Twenty-three patients diagnosed with BD-I and 22 healthy controls (HC) were included. Levels of phosphorus metabolites were measured at baseline and during visual stimulation in the occipital lobe using (31)P magnetic resonance spectroscopy at 4T. Changes in metabolite levels showed different patterns between the groups. During stimulation, HC had significant reductions in PCr but not in ATP, as expected. In contrast, BD patients had significant reductions in ATP but not in PCr. In addition, PCr/ATP ratio was lower at baseline in patients, and there was a higher change in this measure during stimulation. This pattern suggests a disease-related failure to replenish ATP from PCr through CK enzyme catalysis during tissue activation. Further studies measuring the CK flux in BD are required to confirm and extend this finding.
Assuntos
Trifosfato de Adenosina/metabolismo , Transtorno Bipolar/metabolismo , Encéfalo/metabolismo , Creatina Quinase/metabolismo , Fosfocreatina/metabolismo , Adulto , Estudos de Casos e Controles , Metabolismo Energético , Feminino , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Estimulação LuminosaRESUMO
Use of the cre transgene in in vivo mouse models to delete a specific 'floxed' allele is a well-accepted method for studying the effects of spatially or temporarily regulated genes. During the course of our investigation into the effect of cyclic adenosine 3',5'-monophosphate-dependent protein kinase A (PKA) expression on cell death, we found that cre expression either in cultured cell lines or in transgenic mice results in global changes in PKA target phosphorylation. This consequently alters gene expression profile and changes in cytokine secretion such as IL-6. These effects are dependent on its recombinase activity and can be attributed to the upregulation of specific inhibitors of PKA (PKI). These results may explain the cytotoxicity often associated with cre expression in many transgenic animals and may also explain many of the phenotypes observed in the context of Cre-mediated gene deletion. Our results may therefore influence the interpretation of data generated using the conventional cre transgenic system.
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Integrases/metabolismo , Animais , Apoptose , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Regulação para Baixo , Deleção de Genes , Integrases/genética , Interleucina-6/metabolismo , Camundongos , Camundongos Transgênicos , Fosforilação , Transdução de Sinais , Transgenes , Regulação para CimaRESUMO
BACKGROUND: Imatinib is a direct and potent inhibitor of the constitutively active tyrosine kinase, breakpoint cluster region-Abelson (Bcr-Abl), which is central to the pathogenesis of chronic myeloid leukaemia (CML) patients. As such, imatinib has become the front-line treatment for CML patients. However, the recent emergence of imatinib resistance, commonly associated with point mutations within the kinase domain, has led to the search for alternative drug treatments and combination therapies for CML. METHODS: In this report, we analyse the effects of representative members of the novel pro-apoptotic microtubule depolymerising pyrrolo-1,5-benzoxazepines or PBOX compounds on chemotherapy-refractory CML cells using a series of Bcr-Abl mutant cell lines, clinical ex vivo patient samples and an in vivo mouse model. RESULTS: The PBOX compounds potently reduce cell viability in cells expressing the E225K and H396P mutants as well as the highly resistant T315I mutant. The PBOX compounds also induce apoptosis in primary CML samples including those resistant to imatinib. We also show for the first time, the in vivo efficacy of the pro-apoptotic PBOX compound, PBOX-6, in a CML mouse model of the T315I Bcr-Abl mutant. CONCLUSION: Results from this study highlight the potential of these novel series of PBOX compounds as an effective therapy against CML.
Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Oxazepinas/farmacologia , Pirróis/farmacologia , Adulto , Idoso , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Separação Celular , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Citometria de Fluxo , Genes abl/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , MutaçãoAssuntos
Antineoplásicos/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Quimeras de Transplante , Benzamidas , Resistencia a Medicamentos Antineoplásicos/genética , Transplante de Células-Tronco Hematopoéticas , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Transfusão de Linfócitos , Masculino , Pessoa de Meia-Idade , Transplante HomólogoRESUMO
To determine the proangiogenesis effect of series of saccharides and a synthetic oligosaccharide and potential mechanisms, an in vitro 3-dimensional endothelial cell sprouting (3D-ECS) assay and the chick chorioallantoic membrane (CAM) model were used. We demonstrated that a sulfated oligosaccharide significantly promotes the endothelial capillary network initiated by vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF). Furthermore, although the capillary network initiated by VEGF and b-FGF lasts no more than 7 days, addition of a sulfated oligosaccharide significantly amplifies angiogenesis and stabilizes the capillary network of new blood vessels. In the CAM model, sulfated oligosaccharide also stimulated angiogenesis. In both the CAM and the 3D-ECS assay, structure-function studies reveal that increased saccharide chain length up to the hexa- to decasaccharide show optimal proangiogenesis efficacy. In addition, the sulfation and molecular shape (branched vs linear) of oligosaccharide are important for sustained proangiogenesis efficacy. Data indicate that chemically defined synthetic oligosaccharides can play an important role in regulation of capillary structure and stability, which may contribute to future advances in therapeutic angiogenesis. The proangiogenesis efficacy of an oligosaccharide is mediated via integrin alphavbeta3 and involves mitogen-activated protein kinase signaling mechanisms.
Assuntos
Neovascularização Fisiológica/efeitos dos fármacos , Oligossacarídeos/farmacologia , Animais , Embrião de Galinha , Membrana Corioalantoide/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Heparina/farmacologia , Relação Estrutura-Atividade , Fator A de Crescimento do Endotélio Vascular/farmacologiaRESUMO
BACKGROUND: In minor clean procedures, such as inguinal hernia repair and varicocelectomy, the efficacy of systemic perioperative antibiotic prophylaxis is not well established. To determine the efficacy of topical antibiotic prophylaxis alone in preventing postoperative wound infection in a minor urologic clean procedure, we retrospectively reviewed the medical records of 1,654 patients who had undergone microsurgical varicocelectomy. STUDY DESIGN: From September 1985 until December 2000, 1,654 men underwent 2,554 microsurgical varicocelectomies (900 bilateral) by a single surgeon (MG). The skin was shaved and then prepped with standard Betadine gel (Purdue Frederick) that was wiped away with 70% ethanol. No systemic antibiotics were used. The wound was irrigated with 1% neomycin at the moment the incision was made, and then every few minutes until the completion of the procedure, which averaged 45 minutes per side. No postoperative antibiotics were used. RESULTS: No wound infections occurred. No patient developed an adverse reaction to topical application of neomycin. One can conclude that the infection rate in this study is no higher than 0.2% with 95% confidence. CONCLUSIONS: Our review of a large series of consecutive clean urologic procedures indicates that by combining a skin preparation of Betadine gel and 70% ethanol with perioperative topical neomycin irrigation at the moment of skin incision, the risk of postoperative wound infection when performing microsurgical varicocelectomy can be effectively reduced to less than 0.2%.
Assuntos
Antibacterianos/uso terapêutico , Anti-Infecciosos Locais/uso terapêutico , Antibioticoprofilaxia , Quimioterapia Combinada/uso terapêutico , Neomicina/uso terapêutico , Povidona-Iodo/uso terapêutico , Infecção da Ferida Cirúrgica/prevenção & controle , Administração Tópica , Antibacterianos/administração & dosagem , Anti-Infecciosos Locais/administração & dosagem , Quimioterapia Combinada/administração & dosagem , Humanos , Masculino , Microcirurgia , Neomicina/administração & dosagem , Povidona-Iodo/administração & dosagem , Estudos Retrospectivos , Irrigação Terapêutica , Varicocele/cirurgiaAssuntos
Neoplasias da Mama/tratamento farmacológico , Revisão de Uso de Medicamentos , Antagonistas de Estrogênios/uso terapêutico , Osteoporose/tratamento farmacológico , Padrões de Prática Médica , Cloridrato de Raloxifeno/uso terapêutico , Idoso , Climatério/efeitos dos fármacos , Aprovação de Drogas , Rotulagem de Medicamentos , Feminino , Humanos , Medicina/estatística & dados numéricos , Menopausa/efeitos dos fármacos , Pessoa de Meia-Idade , Especialização , Estados UnidosRESUMO
Emphysematous cystitis is a somewhat uncommon entity in which early diagnosis and treatment play a key role in avoiding potentially high morbidity and mortality. An elderly woman with emphysematous cystitis and no comorbid factors, except advanced age, is presented. This case illustrates the key features in the radiographic diagnosis of this unusual disease. Discussion of the cause, diagnosis, and treatment of emphysematous cystitis emphasizes prompt recognition, drainage of the bladder and use of appropriate broad spectrum antibiotic therapy.
Assuntos
Cistite/diagnóstico , Enfisema/diagnóstico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Cistite/diagnóstico por imagem , Cistite/terapia , Drenagem , Enfisema/diagnóstico por imagem , Enfisema/terapia , Feminino , Seguimentos , Humanos , Radiografia , Fatores de TempoRESUMO
Mucopolysaccharidosis type VII (MPS VII) is a lysosomal storage disease caused by the lack of beta-glucuronidase (GUSB) activity. GUSB deficiency leads to the progressive accumulation of undegraded glycosaminoglycans (GAGs) in cells of most tissues, including the brain, and is associated with mental retardation. Reduction of lysosomal storage in the central nervous system and prevention of cognitive dysfunction may require intracranial delivery of a therapeutic agent during the newborn period that provides a continuous source of GUSB. Therefore, we injected recombinant adeno-associated virus encoding human GUSB into both the anterior cortex and the hippocampus of newborn MPS VII mice. Total GUSB activity in the brain approached normal levels by 18 weeks. Although GUSB activity was concentrated near the injection sites, lysosomal distension was reduced in most areas of the brain. In addition to histopathologic evidence of GAG reduction, the previously undescribed accumulation of GM2 and GM3 gangliosides in the brain was also prevented. Furthermore, GUSB expression and reduced lysosomal distension correlated with improvements in cognitive function as measured in the Morris Water Maze test. These findings indicate that localized overexpression of GUSB has positive effects on the pathology and cognitive function and does not have overt toxicity.
Assuntos
Dependovirus/genética , Terapia Genética , Vetores Genéticos , Glucuronidase/genética , Mucopolissacaridose VII/terapia , Animais , Animais Recém-Nascidos , Córtex Cerebral , Expressão Gênica , Técnicas de Transferência de Genes , Glucuronidase/deficiência , Glucuronidase/uso terapêutico , Hipocampo , Injeções , Camundongos , Modelos Animais , Mucopolissacaridose VII/fisiopatologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoAssuntos
Modelos Animais de Doenças , Hiperplasia Prostática/complicações , Coelhos/fisiologia , Obstrução do Colo da Bexiga Urinária/fisiopatologia , Adaptação Fisiológica , Animais , Betanecol/farmacologia , Sinalização do Cálcio , ATPases Transportadoras de Cálcio/análise , Carbacol/farmacologia , Colina O-Acetiltransferase/análise , Tecido Conjuntivo/patologia , Retículo Endoplasmático/enzimologia , Glicólise , Humanos , Ligadura , Masculino , Microscopia Eletrônica , Mitocôndrias Musculares/metabolismo , Modelos Animais , Agonistas Muscarínicos/farmacologia , Contração Muscular/efeitos dos fármacos , Proteínas Musculares/análise , Músculo Liso/efeitos dos fármacos , Músculo Liso/enzimologia , Músculo Liso/ultraestrutura , Tamanho do Órgão , Fosforilação Oxidativa , Parassimpatectomia , Receptores Muscarínicos/efeitos dos fármacos , Retículo Sarcoplasmático/enzimologia , Especificidade da Espécie , Obstrução do Colo da Bexiga Urinária/etiologiaRESUMO
Apoptosis, a physiological process for killing cells, is critical for the normal development and function of multicellular organisms. Abnormalities in cell death control can contribute to a variety of diseases, including cancer, autoimmunity, and degenerative disorders. Signaling for apoptosis occurs through multiple independent pathways that are initiated either from triggering events within the cell or from outside the cell, for instance, by ligation of death receptors. All apoptosis signaling pathways converge on a common machinery of cell destruction that is activated by a family of cysteine proteases (caspases) that cleave proteins at aspartate residues. Dismantling and removal of doomed cells is accomplished by proteolysis of vital cellular constituents, DNA degradation, and phagocytosis by neighboring cells. This article reviews current knowledge of apoptosis signaling, lists several pressing questions, and presents a novel model to explain the biochemical and functional interactions between components of the cell death regulatory machinery.
Assuntos
Apoptose/fisiologia , Transdução de Sinais/fisiologia , Animais , Caspases/fisiologia , Humanos , Modelos Biológicos , Neoplasias/patologia , Neoplasias/fisiopatologia , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Receptores do Fator de Necrose Tumoral/fisiologiaRESUMO
Histone deacetylases play key roles in the regulation of gene transcription. Studies have shown that expression of interleukins IL-2 and IL-8, and insulin-like growth factor 2 (IGF2) are affected by treatment with histone deacetylase inhibitors. We have previously shown that the gene for histone deacetylase 1 (HDAC1) is upregulated following treatment with TSA. The murine homologue of this gene has been reported to be inducible by IL-2. In this study, we have examined the effects IL-2, IGF-II and TSA have on HDAC1 expression in the human hepatocellular carcinoma derived cell line Hep3B. Our results indicate that in contrast to the mouse, HDAC1 is not inducible by IL-2. However, in TSA treated cells, IL-2 and IGF-II were found to act synergistically to reduce TSA induced HDAC1 mRNA levels almost to normal.
Assuntos
Inibidores Enzimáticos/farmacologia , Inibidores de Histona Desacetilases , Histona Desacetilases/biossíntese , Ácidos Hidroxâmicos/farmacologia , Fator de Crescimento Insulin-Like II/farmacologia , Interleucina-2/farmacologia , Acetilação , Animais , Sinergismo Farmacológico , Citometria de Fluxo/métodos , Histona Desacetilase 1 , Histonas/metabolismo , Humanos , Camundongos , Células Tumorais CultivadasAssuntos
Apoptose , Proteínas de Escherichia coli , Proteínas de Insetos , Proteínas , Animais , Proteínas de Bactérias/metabolismo , Ciclo Celular , Divisão Celular , Coenzima A Ligases/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Humanos , Proteínas Inibidoras de Apoptose , NF-kappa B/metabolismo , Subunidade p50 de NF-kappa B , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Citocinas/metabolismo , Transdução de Sinais , Fator de Transcrição RelA , Fatores de Transcrição/metabolismoRESUMO
The tumor suppressor p53 exerts its antioncogenic effects in cells chiefly by regulating their progression through the cell cycle and by inducing cell death. It has been claimed that p53-transduced apoptosis involves the death receptor CD95 (Fas/APO-1). We report that thymocytes from mice lacking functional Fas ligand (gld) show normal sensitivity to apoptosis transduced by p53, and that hepatocytes fromp53-/- mice have normal sensitivity to apoptosis triggered through ligation of CD95. p53 and CD95, therefore, function in independent pathways to cell death in these diverse cell types.
Assuntos
Apoptose/genética , Genes p53 , Transdução de Sinais/genética , Receptor fas/genética , Animais , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos , Especificidade da Espécie , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Receptor fas/metabolismoRESUMO
Damage to DNA produces cell cycle arrest, apoptosis, or both. The response in cells with p53 tumor suppressor function involves transcriptional changes, but whether that holds for cells lacking active p53, as in most tumors, is not known. Better characterization of the DNA damage response in tumors lacking p53 function is relevant to cytotoxic therapy. We have explored whether gamma-irradiated p53-null mouse T lymphoma cells undergo marked changes in transcription. Their arrest in G2/M prior to apoptosis required transcription. Transcripts whose abundance altered on irradiation were sought by subtractive hybridization, and 1010 candidate clones from two oppositely enriched cDNA populations were sequenced. Hybridization revealed small (<3-fold) increases or decreases in the transcripts of more than 15 genes, including some implicated in cell cycle control (e.g., BTG, Bap1) or apoptosis (e.g., STAT1, calpain), but no marked changes like those associated with other forms of T-cell death. Moreover, the expression of some critical apoptosis regulators, such as Bcl-2 family members, did not change. Hence, the G2/M arrest and apoptosis in the irradiated p53-null lymphoma appears to involve modest expression changes for many genes, but post-transcriptional alterations may be more critical.
Assuntos
Apoptose/fisiologia , Genes p53/fisiologia , Linfócitos T/citologia , Animais , Apoptose/genética , Apoptose/efeitos da radiação , Northern Blotting , Divisão Celular/fisiologia , Divisão Celular/efeitos da radiação , Dactinomicina/farmacologia , Raios gama , Genes p53/genética , Linfoma de Células T , Camundongos , Inibidores da Síntese de Ácido Nucleico/farmacologia , Linfócitos T/efeitos da radiação , Transcrição Gênica , Células Tumorais CultivadasRESUMO
OBJECTIVE: To compare directly the biochemistry and contractile responses of rat and rabbit bladder to different stimuli. Materials and methods Sexually mature male New Zealand White rabbits and Sprague Dawley rats were compared. Each bladder was excised while the animal was anaesthetized; longitudinal bladder strips were cut and then mounted in an organ bath. Tension (2 g) was placed on all strips and each underwent field stimulation (FS) for a total of 20 s at 1-32 Hz, 1 ms and 80 V and was exposed to carbachol (100 micromol/L), ATP (2 mmol/L) and KCl (120 mmol/L). The tension was monitored continually using a polygraph and data stored digitally in a computer. The responses to each stimulus were determined as the maximum tension generated, maximum rate of tension generation and duration to a maximum response. The Ca2+- ATPase activity of the rat and rabbit bladder was determined. Bladder pressures were then predicted from the strip data using Laplace's law and compared with published values. RESULTS: Contractile responses (per unit tissue mass) of rat bladder strips were significantly greater than those of rabbit bladder strips at all frequencies of FS and to carbachol, KCl and ATP. The rate of contractile force generated by rat bladder strips in response to all stimuli were significantly greater than that generated by rabbit strips. Rabbit bladder strips took significantly longer to generate maximum tension than did rat bladder strips in response to pharmacological stimuli. In response to FS, rat strips took significantly longer than rabbit strips to generate maximum tension. Although the predicted rat bladder pressures were significantly greater than those for rabbit, the predicted pressures for both the rat and rabbit were significantly lower than the pressure responses of the isolated whole bladder model. The contractile data correlated well with the Ca2+-ATPase activity data; rat bladder had seven times the enzyme activity of rabbit bladder. CONCLUSION: Per unit mass, rat bladder is capable of generating more than five times the tension of rabbit bladder. Similarly, the rate of tension generation by rat bladder is three to five times greater than that by rabbit bladder. The duration to maximum tension generated in response to FS compared with pharmacological stimuli was affected by the inherent difference in the rate of contractile response to electrical activation compared with agents which diffuse through tissue, and by the difference in size between rat and rabbit bladder smooth muscle cells.
Assuntos
Bexiga Urinária/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Carbacol/farmacologia , Estimulação Elétrica , Masculino , Contração Muscular , Músculo Liso/fisiologia , Cloreto de Potássio/farmacologia , Coelhos , Ratos , Ratos Sprague-Dawley , Especificidade da EspécieRESUMO
Apoptosis, an evolutionarily conserved process for killing unwanted cells in multicellular organisms, is essential for normal development, tissue homeostasis and as a defense against pathogens. The control of apoptosis is of considerable importance for clinical medicine, as its deregulation can lead to cancer, autoimmunity or degenerative diseases. We have disrupted the Bim gene in the mouse and demonstrated that it plays a major and non-redundant role in embryogenesis, in the control of hematopoietic cell death, and as a barrier against autoimmunity.