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1.
J Cancer Educ ; 27(2): 353-61, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22210191

RESUMO

Many breast cancer survivors may be at increased risk for physical and psychological complications from cancer treatments. Research has shown that regular exercise can help ameliorate some of the lingering side effects of breast cancer treatments and improve health-related quality of life (HRQOL). Additionally, certain stress management techniques have helped increase HRQOL in breast cancer survivors. Few educational programs exist which address both the promotion of physical activity and use of mindfulness-based strategies to improve the health of breast cancer survivors. Community-based wellness workshops were designed to promote regular exercise and use of mindfulness-based techniques. There was an increase in physical activity and improvements on several HRQOL domains 1 month following the exercise workshops; although the results were not significant, they are encouraging.


Assuntos
Neoplasias da Mama/psicologia , Neoplasias da Mama/reabilitação , Exercício Físico , Nível de Saúde , Qualidade de Vida , Sobreviventes/psicologia , Mulheres/educação , Adulto , Idoso , Atitude Frente a Saúde , Neoplasias da Mama/terapia , Aconselhamento , Educação , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Pessoa de Meia-Idade , Saúde da Mulher
2.
Int J Clin Pract Suppl ; (166): 53-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20377665

RESUMO

Obesity has reached epidemic proportions and is continuing to grow into one of the leading healthcare issues worldwide. With this development, bariatric surgery has emerged as an acceptable treatment for morbid obesity, generally achieving meaningful and sustained weight loss. In a surprising turn of events, bariatric surgery was also found to be the most effective therapy for type 2 diabetes mellitus (T2DM). This observation has sparked a great deal of research that has improved our understanding of T2DM pathophysiology; it has facilitated the development of medical treatment and is expanding the indications for bariatric surgery. It was traditionally accepted that bariatric surgery causes weight loss by restriction of gastric volume, intestinal malabsorption, or a combination of the two. Laparoscopic adjustable gastric banding (LAGB) is considered a purely restrictive procedure that involves the placement of an adjustable band around the cardia of the stomach, creating a 15 ml pouch. Laparoscopic sleeve gastrectomy (LSG) is the resection of the fundus all along the greater curvature of the stomach. LSG was once considered a restrictive procedure, but this presumption has recently come under scrutiny. Bilio-pancreatic diversion (BPD) is an example of a procedure that was considered predominantly malabsorptive. In this operation, the ingested nutrients are diverted from the stomach to the ileum, bypassing a large segment of proximal bowel. Roux-en-Y gastric bypass (RYGB) traditionally combines both mechanisms, partitioning a small pouch from the proximal stomach and diverting the ingested nutrients to the jejunum with a roux-en-Y gastro-jejunostomy. However, recent investigation suggests additional mechanisms of action including hormonal. Today, RYGB is the procedure of choice for morbidly obese patients. The effect of bariatric surgery on T2DM was initially described in 1995 by Pories et al., who reported that there was an overall T2DM resolution after RYGB of 82.9% (1). A resolution rate of approximately 80% has been demonstrated repeatedly (2,3). The initial assumption was that the mechanism causing this effect was through weight loss. It is becoming evident that the anti-diabetic effect is not entirely weight loss as there is a consistent observation that the improvement of glucose and insulin levels occurs within days after RYGB, clearly too soon to be due to the weight loss (1,4). The ensuing body of literature has generated two leading theories attempting to explain this weight-independent anti-diabetic effect after RYGB. The 'hindgut' proposes that rapid delivery of partially digested nutrients to the distal bowel up-regulates the secretion of incretins such as glucagon-like peptide-1 (GLP-1). The result of the increased incretin secretion is an enhanced glucose-dependent insulin secretion, as well as a number of other changes causing improved glucose tolerance (4). In the second theory, 'the foregut hypothesis', the exclusion of the duodenum results in the inhibition of a 'putative' signal that is responsible for insulin resistance (IR) and/or abnormal glycaemic control. In a non-obese diabetic rat model, surgical diversion of the proximal bowel caused rapid improvement of diabetes without reduction of food intake or change in weight (5). Many aspects regarding surgical treatment of T2DM are still questionable and unexplained. Emerging data are starting to clarify the mechanisms participating in the anti-diabetic effect, and also challenging long-held theories.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2/cirurgia , Animais , Diabetes Mellitus Tipo 2/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Humanos , Incretinas/metabolismo , Obesidade/metabolismo
3.
Artigo em Inglês | MEDLINE | ID: mdl-21209387

RESUMO

The influence of histone amino-terminal covalent modifications on gene regulation has drawn intense research efforts in recent years. It is now clear that activating and inactivating modifications have a key role in determining the gene-expression profile of an individual cell or cell lineage. Thus, differences in these modifications have a pivotal role in determining and maintaining cell fate during development. The interplay of histone methyltransferases (HMTs) and demethylases confers the plasticity necessary for changes in the gene-expression profile of a cell during differentiation or changes following environmental cues. The histone H3 lysine 27 (H3K27) demethylases Jmjd3 and UTX remove the gene-inactivating H3K27 dimethyl and trimethyl marks and are involved in inducing and/or maintaining gene expression. In this chapter, we highlight the role of the H3K27 demethylases Jmjd3 and UTX in gene expression.


Assuntos
Regulação da Expressão Gênica , Histona Desmetilases/metabolismo , Histonas/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Lisina/metabolismo , Proteínas Nucleares/metabolismo , Transcrição Gênica , Diferenciação Celular/genética , Senescência Celular/genética , Genoma Humano/genética , Histona Desmetilases/química , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/química , Neoplasias/enzimologia , Neoplasias/genética , Proteínas Nucleares/química
4.
Int J Colorectal Dis ; 24(10): 1181-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19488766

RESUMO

PURPOSE: The purpose of this study was to investigate the oncological and clinical outcome of ulcerative colitis (UC) patients with coexisting colorectal cancer/dysplasia following stapled ileal pouch-anal anastomosis (IPAA). MATERIALS AND METHODS: One hundred eighty-five UC patients who underwent stapled IPAA were followed prospectively in a comprehensive pouch clinic. They were divided into three groups: colorectal cancer, dysplasia, and no cancer/dysplasia. Demographic parameters, clinical data, and oncological and functional outcome of the three groups were compared. RESULTS: Sixteen patients had cancer and 14 had dysplasia. Two of the three cancer patients who developed metastatic disease died. One patient who had rectal cancer was found to have cancer cells in the rectal cuff 10 years after IPAA. All other cancer/dysplasia patients were disease-free at 62 months (median). The 5-year survival rate was 87.5% for the cancer group and 100% for the others (p < 0.0001). Chemotherapy (nine patients) did not affect pouch function. Two rectal cancer patients who received radiotherapy did not maintain a functioning pouch. Overall pouch failure rates were 19%, 7%, and 6% for cancer, dysplasia, and no-cancer/dysplasia patients, respectively (p = 0.13). The mean frequency of bowel movements in 24 h was similar between the groups. CONCLUSIONS: Stapled IPAA is a reasonable option for UC patients with cancer/dysplasia. Chemotherapy is safe, but the effect of radiation on pouch outcome is worrisome. Close long-term follow-up for UC patients with cancer/dysplasia is recommended for early detection of possible recurrence.


Assuntos
Colite Ulcerativa/complicações , Colite Ulcerativa/cirurgia , Bolsas Cólicas , Neoplasias Colorretais/complicações , Neoplasias Colorretais/cirurgia , Grampeamento Cirúrgico , Adulto , Anastomose Cirúrgica , Neoplasias Colorretais/patologia , Demografia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias
5.
Curr Top Microbiol Immunol ; 325: 243-62, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18637510

RESUMO

Human cytomegalovirus (HCMV) has evolved numerous strategies to commandeer the host cell for producing viral progeny. The virus manipulates host cell cycle pathways from the early stages of infection to stimulate viral DNA replication at the expense of cellular DNA synthesis. At the same time, cell cycle checkpoints are by-passed, preventing apoptosis and allowing sufficient time for the assembly of infectious virus.


Assuntos
Ciclo Celular , Citomegalovirus/fisiologia , Replicação Viral , Humanos
6.
J Vet Intern Med ; 22(4): 839-43, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18482276

RESUMO

BACKGROUND: Early diagnosis and treatment are associated with an improved prognosis in blastomycosis. The diagnosis of blastomycosis may be missed by cytology, histopathology, culture, or serology. An enzyme immunoassay (EIA) for detection of Blastomyces dermatitidis galactomannan antigen in body fluids has been used for rapid diagnosis of blastomycosis in humans. HYPOTHESIS: Measurement of Blastomyces antigen in urine or serum by the MVista Blastomyces antigen EIA is more sensitive than measurement of anti-Blastomyces antibodies for diagnosis of blastomycosis in dogs. METHODS: Serum and urine samples from 46 dogs with confirmed blastomycosis were tested for Blastomyces antigen and serum was tested for anti-Blastomyces antibodies. RESULTS: The sensitivity for the detection of antigen in urine was 93.5% and it was 87.0% in serum. The sensitivity of antibody detection by agar gel immunodiffusion (AGID) was 17.4% and it was 76.1% by EIA. Antigen and antibody decreased during itraconazole treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Antigen detection is a more sensitive test for diagnosis of blastomycosis than antibody testing by AGID, the only commercially available method. Antigen concentrations decreased with treatment.


Assuntos
Anticorpos Antifúngicos/imunologia , Antígenos de Fungos/imunologia , Blastomicose/veterinária , Doenças do Cão/imunologia , Técnicas Imunoenzimáticas/veterinária , Animais , Anticorpos Antifúngicos/urina , Antifúngicos/uso terapêutico , Antígenos de Fungos/urina , Blastomyces/imunologia , Blastomicose/diagnóstico , Blastomicose/tratamento farmacológico , Blastomicose/imunologia , Doenças do Cão/tratamento farmacológico , Doenças do Cão/urina , Cães , Itraconazol/uso terapêutico , Sensibilidade e Especificidade , Fatores de Tempo
7.
Cell ; 107(6): 727-38, 2001 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-11747809

RESUMO

Coating of the X chromosome by Xist RNA is an essential trigger for X inactivation. However, little is known about the early chromatin remodeling events that transform this signal into transcriptional silencing. Here we report that methylation of histone H3 lysine 9 on the inactive X chromosome occurs immediately after Xist RNA coating and before transcriptional inactivation of X-linked genes. X-chromosomal H3 Lys-9 methylation occurs during the same window of time as H3 Lys-9 hypoacetylation and H3 Lys-4 hypomethylation. Histone H3 modifications thus represent the earliest known chromatin changes during X inactivation. We also identify a unique "hotspot" of H3 Lys-9 methylation 5' to Xist, and we propose that this acts as a nucleation center for Xist RNA-dependent spread of inactivation along the X chromosome via H3 Lys-9 methylation.


Assuntos
Diferenciação Celular/fisiologia , Cromatina/metabolismo , Proteínas Cromossômicas não Histona , Mecanismo Genético de Compensação de Dose , Histonas/metabolismo , Proteínas Proto-Oncogênicas , Proteínas Repressoras , Cromossomo X/metabolismo , Proteínas de Ancoragem à Quinase A , Acetilação , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p27 , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Inibidores Enzimáticos/metabolismo , Feminino , Fibroblastos/fisiologia , Inativação Gênica , Hibridização in Situ Fluorescente , Masculino , Proteína 2 de Ligação a Metil-CpG , Metilação , Camundongos , Antígenos de Histocompatibilidade Menor , Modelos Biológicos , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , RNA/metabolismo , RNA Longo não Codificante , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Células-Tronco/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
9.
Virology ; 284(2): 297-307, 2001 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-11384228

RESUMO

The isolation of viruses with mutations in essential genes requires that they be propagated in cells expressing the wild-type proteins. This has been a particularly challenging problem for studying mutations in the human cytomegalovirus (HCMV) immediate early (IE) gene, IE2 86. In the past, we tried a number of approaches to derive human fibroblasts expressing wild-type IE2 86, but were unable to maintain expression of a fully functional protein. To overcome this obstacle, we developed a strategy whereby recombinant baculoviruses were used as vectors for the expression of HCMV IE proteins in primary human fibroblasts (FFs). The IE2 86 and IE1 72 cDNAs, as well as the genomic fragment of the UL122-123 region under the control of a chicken actin promoter, were introduced into the baculovirus genome by site-specific transposition in Escherichia coli. Recombinant "bacmid" DNAs were then transfected into Sf9 cells to generate recombinant baculoviruses. FFs infected at high m.o.i. with these baculoviruses expressed high levels of the HCMV protein for at least 1 week, as determined by immunofluorescence assays and Western blots. Moreover, the IE2 86 protein was found to be fully functional with respect to its ability to activate the HCMV UL112-113 early promoter. Recombinant baculoviruses expressing IE1 72 were also able to efficiently complement HCMV ie1 mutants. These data demonstrate the potential of using recombinant baculoviruses as vectors for the expression of toxic viral genes in human cells and for subsequent isolation of mutant HCMV lacking these essential genes.


Assuntos
Baculoviridae/genética , Citomegalovirus/química , Fibroblastos/metabolismo , Fibroblastos/virologia , Vetores Genéticos , Proteínas Imediatamente Precoces/genética , Animais , Western Blotting , Células Cultivadas , Escherichia coli/genética , Imunofluorescência , Regulação da Expressão Gênica , Técnicas de Transferência de Genes , Genoma Viral , Humanos , Proteínas Imediatamente Precoces/análise , Proteínas Imediatamente Precoces/metabolismo , Mutação , Regiões Promotoras Genéticas , Transfecção
10.
Atherosclerosis ; 155(1): 1-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11223420

RESUMO

Mitral annulus calcification (MAC) is a chronic, non-inflammatory, degenerative process of the fibrous support structure of the mitral valve. It occurs more often in women and the elderly. MAC is associated with known atherosclerotic risk factors such as diabetes mellitus, hypertension and hypercholesterolemia. It is also known that patient with MAC have higher prevalence of left atrial and left ventricular enlargement, hypertrophic cardiomyopathy, atrial fibrillation, aortic valve calcification and stenosis, various cardiac conduction defects, bacterial endocarditis, cardiovascular events and stroke, though the etiological basis is unknown. Pathological studies from the 80s present a theory that MAC is a form of atherosclerosis. In order to test this theory we conducted during the last years a few clinical studies to examine the association of MAC and known atherosclerotic phenomena. We found higher prevalence of aortic atheroma in patients with MAC and atheroma thickness. We also found in MAC patients higher prevalence of carotid artery stenosis, coronary artery stenosis, peripheral artery stenosis and higher levels of beta2-Glycoprotein I antibodies in patients with MAC thickness equal or greater than 5 mm. These studies support the theory that MAC is a form of atherosclerosis and define a group of patients with higher prevalence of atherosclerotic disease in multiple blood vessels. The purpose of this review is to summarize the data concerning MAC and atherosclerotic processes, emphasizing that MAC in itself may be an atherosclerotic process.


Assuntos
Arteriosclerose/complicações , Calcinose/complicações , Valva Mitral , Arteriosclerose/diagnóstico , Arteriosclerose/patologia , Calcinose/patologia , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico , Transtornos Cerebrovasculares/patologia , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/patologia , Humanos , Valva Mitral/patologia , Fatores de Risco
11.
J Biol Chem ; 276(11): 8469-74, 2001 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-11078740

RESUMO

Cadmium is very toxic at low concentrations, but the basis for its toxicity is not clearly understood. We analyzed the proteomic response of yeast cells to acute cadmium stress and identified 54 induced and 43 repressed proteins. A striking result is the strong induction of 9 enzymes of the sulfur amino acid biosynthetic pathway. Accordingly, we observed that glutathione synthesis is strongly increased in response to cadmium treatment. Several proteins with antioxidant properties were also induced. The induction of nine proteins is dependent upon the transactivator Yap1p, consistent with the cadmium hypersensitive phenotype of the YAP1-disrupted strain. Most of these proteins are also overexpressed in a strain overexpressing Yap1p, a result that correlates with the cadmium hyper-resistant phenotype of this strain. Two of these Yap1p-dependent proteins, thioredoxin and thioredoxin reductase, play an important role in cadmium tolerance because strains lacking the corresponding genes are hypersensitive to this metal. Altogether, our data indicate that the two cellular thiol redox systems, glutathione and thioredoxin, are essential for cellular defense against cadmium.


Assuntos
Cádmio/toxicidade , Proteoma , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/efeitos dos fármacos , Cisteína/biossíntese , Proteínas de Ligação a DNA/fisiologia , Glutationa/biossíntese , Glutationa/genética , Estresse Oxidativo , Saccharomyces cerevisiae/genética , Tiorredoxina Redutase 1 , Tiorredoxina Dissulfeto Redutase/fisiologia , Fatores de Transcrição/fisiologia
12.
J Biol Chem ; 276(10): 7011-6, 2001 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-11084050

RESUMO

In an attempt to elucidate the essential function of glutathione in Saccharomyces cerevisiae, we searched for suppressors of the GSH auxotrophy of Deltagsh1, a strain lacking the rate-limiting enzyme of glutathione biosynthesis. We found that specific mutations of PRO2, the second enzyme in proline biosynthesis, permitted the growth of Deltagsh1 in the absence of exogenous GSH. The suppression mechanism by alleles of PRO2 involved the biosynthesis of a trace amount of glutathione. Deletion of PRO1, the first enzyme of the proline biosynthesis pathway, or PRO2 eliminated the suppression, suggesting that gamma-glutamyl phosphate, the product of Pro1 and the physiological substrate of Pro2, is required as an obligate substrate of suppressor alleles of PRO2 for glutathione synthesis. A mutagenesis of a Deltagsh1 strain also lacking the proline pathway failed to generate any suppressor mutants under either aerobic or anaerobic conditions, confirming that glutathione is essential in yeast. This essential function is not related to DNA synthesis based on the terminal phenotype of glutathione-depleted cells or to toxic accumulation of non-native protein disulfides. Analysis of the suppressor strain demonstrates that normal glutathione levels are required for the tolerance to oxidants under acute, but not chronic stress conditions.


Assuntos
Glutamina/análogos & derivados , Glutationa/genética , Glutationa/fisiologia , Mutação , Prolina/biossíntese , Saccharomyces cerevisiae/genética , Alelos , Cromatografia em Camada Fina , Relação Dose-Resposta a Droga , Metanossulfonato de Etila , Deleção de Genes , Biblioteca Gênica , Glutamina/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/farmacologia , Mutagênicos , Estresse Oxidativo , Fenótipo , Saccharomyces cerevisiae/metabolismo , Supressão Genética
13.
J Appl Physiol (1985) ; 88(5): 1690-7, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10797131

RESUMO

Acute exercise increases vascular endothelial growth factor (VEGF), transforming growth factor-beta(1) (TGF-beta(1)), and basic fibroblast growth factor (bFGF) mRNA levels in skeletal muscle, with the greatest increase in VEGF mRNA. VEGF functions via binding to the VEGF receptors Flk-1 and Flt-1. Captopril, an angiotensin-converting enzyme inhibitor, has been suggested to reduce the microvasculature in resting and exercising skeletal muscle. However, the molecular mechanisms responsible for this reduction have not been investigated. We hypothesized that this might occur via reduced VEGF, TGF-beta(1), bFGF, Flk-1, and Flt-1 gene expression at rest and after exercise. To investigate this, 10-wk-old female Wistar rats were placed into four groups (n = 6 each): 1) saline + rest; 2) saline + exercise; 3) 100 mg/kg ip captopril + rest; and 4) 100 mg/kg ip captopril + exercise. Exercise consisted of 1 h of running at 20 m/min on a 10 degrees incline. VEGF, TGF-beta(1), bFGF, Flk-1, and Flt-1 mRNA were analyzed from the left gastrocnemius by quantitative Northern blot. Exercise increased VEGF mRNA 4.8-fold, TGF-beta(1) mRNA 1.6-fold, and Flt-1 mRNA 1.7-fold but did not alter bFGF or Flk-1 mRNA measured 1 h after exercise. Captopril did not affect the rest or exercise levels of VEGF, TGF-beta(1), bFGF, and Flt-1 mRNA. Captopril did reduce Flk-1 mRNA 30-40%, independently of exercise. This is partially consistent with the suggestion that captopril may inhibit capillary growth.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Captopril/farmacologia , Substâncias de Crescimento/metabolismo , Atividade Motora/fisiologia , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica/fisiologia , Animais , Fatores de Crescimento Endotelial/genética , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Linfocinas/genética , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores Proteína Tirosina Quinases/genética , Receptores de Fatores de Crescimento/genética , Receptores de Fatores de Crescimento do Endotélio Vascular , Fator de Crescimento Transformador beta/genética , Fator A de Crescimento do Endotélio Vascular , Receptor 1 de Fatores de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
14.
J Struct Biol ; 129(2-3): 241-51, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10806074

RESUMO

In the mammalian cell nucleus pre-mRNA splicing factors are organized in a speckled pattern. The fluorescence signal within speckles appears homogeneous when cells are immunolabeled with antibodies directed against pre-mRNA splicing factors and examined by fluorescence microscopy. We have reexamined the speckled domains using serial dilutions of antibodies against SR proteins, snRNPs, and a 3' end processing protein by immunofluorescence and confocal laser scanning microscopy. Using higher antibody dilutions, the speckled domains consist of numerous subdomains that are spherical and heterogeneous in size ranging from 0.2 to 0.5 micrometer in diameter. We refer to these subdomains as "subspeckles." Each speckle is composed of 5 to 50 subspeckles and in some cases in actively transcribing cells, strings and loops of subspeckles were observed to extend from the speckled domains. Upon inhibition of RNA polymerase II transcription, the strings and loops of subspeckles were no longer observed. Subspeckles were also not observed in coiled bodies. Using fluorescence in situ hybridization we found subspeckles to be colocalized with transiently expressed beta-tropomyosin RNA transcripts. The compartmentalization into subspeckles may represent an efficient way of organizing these factors for their subsequent transport to transcription/RNA processing sites.


Assuntos
Núcleo Celular/genética , Núcleo Celular/ultraestrutura , Precursores de RNA/genética , Splicing de RNA , Transcrição Gênica , Animais , Linhagem Celular , Cricetinae , Células HeLa , Humanos , RNA Polimerase II/análise , RNA Nuclear Pequeno/análise , Proteínas de Ligação a RNA/análise , Ribonucleoproteínas Nucleares Pequenas/análise , Tropomiosina/genética
15.
J Appl Physiol (1985) ; 88(4): 1192-8, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10749807

RESUMO

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-beta(1) (TGF-beta(1)) mRNA increase in rat skeletal muscle in response to a single acute exercise bout. Nitric oxide (NO) is released locally by muscle vascular endothelium and muscle fibers during exercise, contributes to the blood flow response to exercise, and regulates mitochondrial respiration. We hypothesized that a reduction in NO production, via NO synthase inhibition, would demonstrate a link between NO and the VEGF, bFGF, and TGF-beta(1) gene responses to exercise. To investigate this hypothesis, 9-wk-old female Wistar rats were divided into eight treatment groups (n = 6 each): 1) saline + rest, 2) saline + exercise, 3) 30 mg/kg N(omega)-nitro-L-arginine methyl ester (L-NAME, a known NOS inhibitor) + rest, 4) 30 mg/kg L-NAME + exercise, 5) 300 mg/kg L-NAME + rest, 6) 300 mg/kg L-NAME + exercise, 7) 300 mg/kg N(omega)-nitro-D-arginine methyl ester (D-NAME, inactive enantiomer of L-NAME) + rest, and 8) 300 mg/kg D-NAME + exercise. Exercise consisted of 1 h of running at 20 m/min on a 10 degrees incline. VEGF, TGF-beta(1), and bFGF mRNA from left gastrocnemius were analyzed by quantitative Northern blot. Submaximal exercise for 1 h increased VEGF mRNA 4.2-fold and TGF-beta(1) mRNA 1.5-fold in untreated rats but did not increase bFGF mRNA. The exercise-induced increase in VEGF mRNA was attenuated approximately 50% by 30 and 300 mg/kg L-NAME; the TGF-beta(1) mRNA increase was unaffected by 300 mg/kg L-NAME. In addition, 300 mg/kg D-NAME had no effect on the exercise-induced increase in VEGF mRNA. Administration of 300 mg/kg L-NAME had no effect on bFGF mRNA. These findings suggest that NO is important in the regulation of the VEGF gene response to exercise through increases in VEGF transcription or by increases in the VEGF mRNA half-life.


Assuntos
Fatores de Crescimento Endotelial/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Linfocinas/genética , Músculo Esquelético/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Esforço Físico/fisiologia , Transcrição Gênica/efeitos dos fármacos , Animais , Inibidores Enzimáticos/farmacologia , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Músculo Esquelético/enzimologia , Condicionamento Físico Animal , RNA Mensageiro/genética , Ratos , Ratos Wistar , Descanso , Estereoisomerismo , Fator de Crescimento Transformador beta/genética , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
16.
J Virol ; 74(8): 3696-708, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10729145

RESUMO

The cytotoxic T-lymphocyte (CTL) response against the murine cytomegalovirus (MCMV) immediate-early gene 1 (IE1) 89-kDa phosphoprotein pp89 plays a major role in protecting BALB/c mice against the lethal effects of the viral infection. CTL populations specific to MCMV early-phase and structural antigens are also generated during infection, but the identities of these antigens and their relative contributions to overall immunity against MCMV are not known. We previously demonstrated that DNA vaccination with a pp89-expressing plasmid effectively generated a CTL response and conferred protection against infection (J. C. Gonzalez Armas, C. S. Morello, L. D. Cranmer, and D. H. Spector, J. Virol. 70:7921-7928, 1996). In this report, we have sought (i) to identify other viral antigens that contribute to immunity against MCMV and (ii) to determine whether the protective response is haplotype specific. DNA immunization was used to test the protective efficacies of plasmids encoding MCMV homologs of human cytomegalovirus (HCMV) tegument (M32, M48, M56, M82, M83, M69, and M99), capsid (M85 and M86), and nonstructural antigens (IE1-pp89 and M84). BALB/c (H-2(d)) and C3H/HeN (H-2(k)) mice were immunized by intradermal injection of either single plasmids or cocktails of up to four expression plasmids and then challenged with sublethal doses of virulent MCMV administered intraperitoneally. In this way, we identified a new viral gene product, M84, that conferred protection against viral replication in the spleens of BALB/c mice. M84 is expressed early in the infection and encodes a nonstructural protein that shares significant amino acid homology with the HCMV UL83-pp65 tegument protein, a major target of protective CTLs in humans. Specificity of the immune response to the M84 protein was confirmed by showing that immunization with pp89 DNA, but not M84 DNA, protected mice against subsequent infection with an MCMV deletion mutant lacking the M84 gene. The other MCMV genes tested did not generate a protective response even when mice were immunized with vaccinia viruses expressing the viral proteins. However, the M84 plasmid was protective when injected in combination with nonprotective plasmids, and coimmunization of BALB/c mice with pp89 and M84 provided a synergistic level of protection in the spleen. Viral titers in the salivary glands were also reduced, but not to the same extent as observed in the spleen, and the decrease was seen only when the BALB/c mice were immunized with pp89 plus M84 or with pp89 alone. The experiments with the C3H/HeN mice showed that the immunity conferred by DNA vaccination was haplotype dependent. In this strain of mice, only pp89 elicited a protective response as measured by a reduction in spleen titer. These results suggest that DNA immunization with the appropriate combination of CMV genes may provide a strategy for improving vaccine efficacy.


Assuntos
Infecções por Herpesviridae/prevenção & controle , Muromegalovirus/imunologia , Muromegalovirus/fisiologia , Vacinas de DNA/imunologia , Proteínas não Estruturais Virais/genética , Vacinas Virais/imunologia , Animais , Modelos Animais de Doenças , Feminino , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/virologia , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/imunologia , Proteínas Imediatamente Precoces/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Fosfoproteínas/metabolismo , Plasmídeos/genética , Vacinação , Vacinas de DNA/administração & dosagem , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/imunologia , Proteínas da Matriz Viral/metabolismo , Proteínas não Estruturais Virais/imunologia , Vacinas Virais/administração & dosagem , Replicação Viral
17.
Trends Microbiol ; 8(3): 111-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10707064

RESUMO

Human cytomegalovirus is a ubiquitous human pathogen that is the leading viral cause of birth defects. It also causes significant morbidity and mortality in both chemically and virally immunosuppressed individuals. Recent studies have begun to elucidate the interplay between this virus and its host cell on a molecular level. The interactions begin upon contact with the cell membrane, involve multiple processes including cell signaling, cell-cycle control and immune response mechanisms, and culminate in a productive infection.


Assuntos
Citomegalovirus/fisiologia , Transdução de Sinais/fisiologia , Ciclo Celular/fisiologia , Citomegalovirus/genética , Citomegalovirus/patogenicidade , Humanos , Interferons/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo
19.
Proc Natl Acad Sci U S A ; 97(2): 853-8, 2000 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-10639169

RESUMO

Human cytomegalovirus (HCMV) is the major viral cause of birth defects and a serious problem for immunocompromised individuals. Here we show that infection of cells with HCMV during the S-phase of the cell cycle results in two specific chromosome 1 breaks at positions 1q42 and 1q21. We demonstrate that purified virions, and not infected cell supernatant alone, are responsible for the damage. In addition, we show that the specific breaks occur when different sources of fibroblasts and strains of HCMV are used. Incubation of the virus with neutralizing antibody prevents the induction of breaks. However, UV-inactivated virus is as efficient as untreated virus in inducing specific damage to chromosome 1. Thus, there is a requirement for viral adsorption/penetration, but not new viral gene expression. This HCMV-mediated induction of site-specific damage in actively dividing cells may provide clues for the development of neurological defects in the congenitally infected infant.


Assuntos
Quebra Cromossômica/genética , Cromossomos Humanos Par 1/genética , Infecções por Citomegalovirus/virologia , Animais , Células Cultivadas , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/genética , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/virologia , Expressão Gênica/efeitos da radiação , Regulação Viral da Expressão Gênica , Humanos , Masculino , Camundongos , Fase S , Especificidade da Espécie , Proteínas Virais/genética , Vírion/metabolismo , Vírion/fisiologia
20.
Nat Cell Biol ; 2(12): 871-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11146650

RESUMO

Chromatin structure is thought to play a critical role in gene expression. Using the lac operator/repressor system and two colour variants of green fluorescent protein (GFP), we developed a system to visualize a gene and its protein product directly in living cells, allowing us to examine the spatial organization and timing of gene expression in vivo. Dynamic morphological changes in chromatin structure, from a condensed to an open structure, were observed upon gene activation, and targeting of the gene product, cyan fluorescent protein (CFP) reporter to peroxisomes was visualized directly in living cells. We found that the integrated gene locus was surrounded by a promyelocytic leukaemia (PML) nuclear body. The association was transcription independent but was dependent upon the direct in vivo binding of specific proteins (EYFP/lac repressor, tetracycline receptor/VP16 transactivator) to the locus. The ability to visualize gene expression directly in living cells provides a powerful system with which to study the dynamics of nuclear events such as transcription, RNA processing and DNA repair.


Assuntos
Expressão Gênica , Animais , Sequência de Bases , Núcleo Celular/genética , Cromatina/genética , Células Clonais , Cricetinae , Primers do DNA/genética , Regulação da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde , Humanos , Óperon Lac , Leucemia Promielocítica Aguda/genética , Proteínas Luminescentes/genética , Proteínas Recombinantes/genética , Proteínas Repressoras/genética , Ativação Transcricional
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