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1.
Health Educ Res ; 32(2): 153-162, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28334909

RESUMO

Behaviour change, specifically that which decreases cancer risk, is an essential element of cancer control. Little information is available about how awareness of risk factors may be changing over time. This study describes the awareness of cancer risk behaviours among adult New Zealanders in two cross-sectional studies conducted in 2001 and 2014/5.Telephone interviews were conducted in 2001 (n = 436) and 2014/5 (n = 1064). Participants were asked to recall things they can do to reduce their risk of cancer. They were then presented with a list of potential risk behaviours and asked if these could increase or decrease cancer risk.Most New Zealand adults could identify at least one action they could take to reduce their risk of cancer. However, when asked to provide specific examples, less than a third (in the 2014/5 sample) recalled key cancer risk reduction behaviours such as adequate sun protection, physical activity, healthy weight, limiting alcohol and a diet high in fruit. There had been some promising changes since the 2001 survey, however, with significant increases in awareness that adequate sun protection, avoiding sunbeds/solaria, healthy weight, limiting red meat and alcohol, and diets high in fruit and vegetables decrease the risk of developing cancer.


Assuntos
Conscientização , Comportamentos Relacionados com a Saúde , Neoplasias/prevenção & controle , Comportamento de Redução do Risco , Adulto , Idoso , Estudos Transversais , Dieta/estatística & dados numéricos , Exercício Físico , Feminino , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Inquéritos e Questionários , Verduras
2.
Cell Death Differ ; 23(5): 903-11, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26768663

RESUMO

Factor H (FH) binds apoptotic cells to limit the inflammatory potential of complement. Here we report that FH is actively internalized by apoptotic cells to enhance cathepsin L-mediated cleavage of endogenously expressed C3, which results in increased surface opsonization with iC3b. In addition, internalized FH forms complexes with nucleosomes, facilitates their phagocytosis by monocytes and induces an anti-inflammatory biased cytokine profile. A similar cytokine response was noted for apoptotic cells coated with FH, confirming that FH diminishes the immunogenic and inflammatory potential of autoantigens. These findings were supported by in vivo observations from CFH(-/-) MRL-lpr mice, which exhibited higher levels of circulating nucleosomes and necrotic cells than their CFH(+/+) littermates. This unconventional function of FH broadens the established view of apoptotic cell clearance and appears particularly important considering the strong associations with genetic FH alterations and diseases such as systemic lupus erythematosus and age-related macular degeneration.


Assuntos
Apoptose , Ativação do Complemento , Complemento C3/metabolismo , Fator H do Complemento/metabolismo , Inflamação/metabolismo , Nucleossomos/metabolismo , Animais , Fator H do Complemento/deficiência , Humanos , Células Jurkat , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
3.
Lupus ; 19(1): 73-82, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19900981

RESUMO

Complement activation is an important aspect of systemic lupus erythematosus. In this study we investigated the role of C3a/C3a receptor (R) signaling in brains of the lupus model, MRL/lpr mice, by treating the mice with C3aR antagonist (a) from 13 to 19 weeks of age. C3aR mRNA (0.2 +/- 0.027 versus 0.56 +/- 0.19) and protein (0.16 +/- 0.09 versus 0.63 +/- 0.19) expression was increased in MRL/lpr brains compared with MRL+/+ controls. Apoptosis, a key feature in lupus brain, was significantly reduced by C3aRa treatment, as assessed by DNA laddering, TUNEL staining and caspase3 activity (48% of MRL/lpr mice). mRNA expression of proinflammatory molecules that cause apoptosis, TNFalpha (0.33 +/- 0.07 versus 0.15 +/- 0.1), MIP2 (3.8 +/- 1.3 versus 1.7 +/- 0.6), and INFgamma (4.8 +/- 1.0 versus 2.07 +/- 1.28) are reduced in MRL/lpr brains with C3aRa treatment. In line with these results, Western blotting demonstrates the significant increase in phosphorylation of survival molecules Akt and Erk, decrease in PTEN and reduced iNOS expression. INFgamma receptor (R) and AMPA-GluR1 co-localized, and concomitant with reduced INFgammaR expression, AMPAGluR1 expression was also decreased by C3aR antagonist. All of these variables that modulate neuronal excitability and regulate synaptic plasticity are C3aR dependent in the MRL/lpr brains and suggest a potential therapeutic role for C3aR inhibition in CNS lupus.


Assuntos
Lúpus Eritematoso Sistêmico/complicações , Doenças Neurodegenerativas/etiologia , Receptores de Complemento/fisiologia , Animais , Apoptose , Ativação do Complemento , Gliose/prevenção & controle , Interferon gama/fisiologia , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Camundongos , Camundongos Endogâmicos MRL lpr , Doenças Neurodegenerativas/prevenção & controle , Neurônios/patologia , Óxido Nítrico Sintase Tipo II/genética , Receptores de AMPA/fisiologia , Receptores de Complemento/antagonistas & inibidores , Transdução de Sinais
4.
Cell Death Differ ; 17(3): 522-33, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19816511

RESUMO

The cellular FLICE inhibitory protein (c-FLIP) is an endogenous inhibitor of the caspase-8 proapoptotic signaling pathway downstream of death receptors. Recent evidence indicates that the long form of c-FLIP (c-FLIP(L)) is required for proliferation and effector T-cell development. However, the role of c-FLIP(L) in triggering autoimmunity has not been carefully analyzed. We now report that c-FLIP(L) transgenic (Tg) mice develop splenomegaly, lymphadenopathy, multiorgan infiltration, high titers of auto-antibodies, and proliferative glomerulonephritis with immune complex deposition in a strain-dependent manner. The development of autoimmunity requires CD4(+) T cells and may result from impaired thymic selection. At the molecular level, c-FLIP(L) overexpression inhibits the zeta chain-associated protein tyrosine kinase of 70 kDa (ZAP-70) activation, thus impairing the signaling pathway derived from ZAP-70 required for thymic selection. Therefore, we have identified c-FLIP(L) as a susceptibility factor under the influence of epistatic modifiers for the development of autoimmunity.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Camundongos Endogâmicos BALB C/imunologia , Camundongos Endogâmicos C57BL/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Timo/imunologia , Animais , Apoptose/fisiologia , Autoanticorpos/metabolismo , Linfócitos B/imunologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas/imunologia , Humanos , Lúpus Eritematoso Sistêmico/patologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , Fenótipo , Subpopulações de Linfócitos T/citologia , Linfócitos T/citologia , Timo/citologia , Transgenes , Proteína-Tirosina Quinase ZAP-70/metabolismo
5.
Kidney Int ; 73(5): 567-77, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18075502

RESUMO

Apoptosis and inflammation, important contributors to the progression of chronic kidney disease, can be influenced by clusterin (a secreted glycoprotein that regulates apoptosis) and nuclear factor-kappaB (NF-kappaB, a transcription factor modifying the expression of inflammatory genes). We studied proteinuria-induced renal disease and its influence on clusterin-mediated apoptosis. Exposure of cultured mouse proximal tubule epithelial cells to bovine serum albumin (BSA) resulted in activation of NF-kappaB and activator protein-1 (AP-1) within hours followed by a decline in their activation, decreased activation of extracellular signal-regulated kinases (ERK1/2), decreased cell-associated antiapoptotic Bcl-xL protein but increased apoptosis. Clusterin progressively increased in the media over a 3 day period. Clusterin siRNA blocked protein production, increased NF-kappaB activation, and significantly increased cellular Bcl-xL protein, thereby reducing spontaneous and BSA-induced apoptosis. An siRNA to the NF-kappaB inhibitor IkappaBalpha had similar results. BSA-stimulated NF-kappaB activation reciprocally decreased AP-1 activity by preventing ERK1/2 phosphorylation. These in vitro studies suggest that clusterin inhibits NF-kappaB-mediated antiapoptotic effects by the apparent stabilization of IkappaBalpha switching from promoting inflammation to apoptosis during proteinuria.


Assuntos
Apoptose , Clusterina/metabolismo , Nefropatias/patologia , Túbulos Renais/patologia , NF-kappa B/metabolismo , Proteína bcl-X/antagonistas & inibidores , Animais , Doença Crônica , Clusterina/antagonistas & inibidores , Clusterina/genética , Citocromos c/metabolismo , Quinase I-kappa B/metabolismo , Nefropatias/metabolismo , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Camundongos , RNA Interferente Pequeno/farmacologia , Soroalbumina Bovina/toxicidade , Fator de Transcrição AP-1/metabolismo , Fator de Transcrição RelA/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/genética
6.
Kidney Int ; 73(2): 163-71, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17928826

RESUMO

1,25-Dihydroxyvitamin D3 negatively regulates the renin-angiotensin system (RAS), which plays a critical role in the development of diabetic nephropathy. We tested if mice lacking the vitamin D receptor (VDR) are more susceptible to hyperglycemia-induced renal injury. Diabetic VDR knockout mice developed more severe albuminuria and glomerulosclerosis due to increased glomerular basement membrane thickening and podocyte effacement. More fibronectin (FN) and less nephrin were expressed in the VDR knockout mice compared to diabetic wild-type mice. In receptor knockout mice, increased renin, angiotensinogen, transforming growth factor-beta (TGF-beta), and connective tissue growth factor accompanied the more severe renal injury. 1,25-Dihydroxyvitmain D3 inhibited high glucose (HG)-induced FN production in cultured mesangial cells and increased nephrin expression in cultured podocytes. 1,25-Dihydroxyvitmain D3 also suppressed HG-induced activation of the RAS and TGF-beta in mesangial and juxtaglomerular cells. Our study suggests that receptor-mediated vitamin D actions are renoprotective in diabetic nephropathy.


Assuntos
Nefropatias Diabéticas/prevenção & controle , Receptores de Calcitriol/fisiologia , Animais , Calcitriol/farmacologia , Fator de Crescimento do Tecido Conjuntivo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/etiologia , Proteínas Imediatamente Precoces/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/análise , Estreptozocina , Fator de Crescimento Transformador beta/genética , Vitamina D/fisiologia
8.
Kidney Int ; 70(5): 882-91, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16820793

RESUMO

The db/db mouse develops features of type II diabetes mellitus as the result of impaired signaling through its abnormal leptin receptor. In spite of accurate metabolic features of diabetes, renal disease manifestations in these mice are not as severe as in humans suggesting the presence of protective genes. There is a growing body of evidence in humans for the relevance of vitamin D in diabetes. Here we followed a large cohort of db/db mice and their non-diabetic db/+ littermates. Transcriptional profiling revealed significant upregulation of 23 genes involved in Ca2+ homeostasis and vitamin D metabolism in db/db glomeruli relative to db/+ glomeruli. Increased glomerular expression of vitamin D3 1alpha-hydroxylase, vitamin D binding protein, calbindins D9K and D28K, and calcyclin mRNA was confirmed by quantitative reverse transcription-polymerase chain reaction in 20-, 36-, and 52-week-old db/db glomeruli. Although vitamin D3 1alpha-hydroxylase protein was primarily expressed and upregulated in db/db renal tubules, it was also expressed in glomerular podocytes in vivo. Serum 1,25-dihydroxyvitamin D3 and urinary Ca2+ excretion were increased >3-fold in db/db mice compared to db/+ mice. Cultured glomerular podocytes had mRNA for vitamin D3 1alpha-hydroxylase, vitamin D receptor, and calbindin D28K, each of which was increased in high glucose conditions. High glucose also led to enhanced production of fibronectin and collagen IV protein, which was blocked by 1,25-dihydroxyvitamin D3. These results show that vitamin D metabolism is altered in db/db mice leading to metabolic and transcriptional effects. The podocyte is affected by paracrine and potentially autocrine effects of vitamin D, which may explain why db/db mice are resistant to progressive diabetic nephropathy.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/prevenção & controle , Glomérulos Renais/metabolismo , Vitamina D/metabolismo , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Animais , Calbindina 1 , Calbindinas , Calcitriol/sangue , Cálcio/metabolismo , Células Cultivadas , Nefropatias Diabéticas/fisiopatologia , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica/fisiologia , Camundongos , Camundongos Mutantes , Podócitos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Proteína G de Ligação ao Cálcio S100/genética , Proteína G de Ligação ao Cálcio S100/metabolismo , Regulação para Cima , Proteína de Ligação a Vitamina D/genética , Proteína de Ligação a Vitamina D/metabolismo
9.
Clin Exp Immunol ; 136(2): 194-9, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15086380

RESUMO

Complement receptor 1-related gene/protein y (Crry) is a potent murine complement regulator that inhibits C3 convertases. Transgenic mice that overexpress soluble Crry (sCrry), directed systemically by the metallothionein-I promoter, have been used as an animal model for chronic blockade of complement activation. Recently we have found that alternative pathway (AP) activity in Crry transgenic mice was not inhibited as much as expected. To elucidate the mechanism of this effect, we evaluated the AP activities and levels of sCrry and AP complement components in transgenic and non-transgenic mice. In transgenic mice, expression of sCrry was induced by feeding zinc sulphate solution to 70.1 +/- 42.7 micro g/ml mean serum level. Its corresponding level of purified sCrry inhibited 49% of AP activity of normal mice serum; however, the actual AP activities in transgenic mice were not decreased when compared to non-transgenic mice (130.2 +/- 9.0%versus 113.0 +/- 35.4%). Expressed sCrry was functional, as immunoprecipitation and removal of sCrry from transgenic sera with rabbit anti-Crry polyclonal antibody resulted in enhanced AP activity, consistent with initial levels of sCrry. We then compared the changes to C3, factor B, factor H and factor D serum levels in transgenic and non-transgenic mice after induction of sCrry expression. Of these only C3 was increased after zinc feeding in transgenic mice compared to non-transgenic mice (142.8 +/- 14.1%versus 121.4 +/- 15.1%, P = 0.023). These results suggest that the inhibitory effect of chronic exposure to sCrry is compensated by concomitant alteration in C3 levels. This result also suggests the presence of a complement regulatory protein controls the level of serum C3, which has potential importance in the design and interpretation of studies involving chronic use of complement inhibitors.


Assuntos
Complemento C3/metabolismo , Via Alternativa do Complemento , Receptores de Complemento/metabolismo , Animais , Fator B do Complemento/análise , Fator D do Complemento/análise , Fator H do Complemento/análise , Citometria de Fluxo , Expressão Gênica , Camundongos , Camundongos Transgênicos , Receptores de Complemento/análise , Receptores de Complemento/genética , Receptores de Complemento 3b , Zinco/administração & dosagem , Zimosan
10.
Kidney Int ; 60(3): 900-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11532085

RESUMO

BACKGROUND: An injection of anti-Fx1A antibodies in rats leads to passive Heymann nephritis (PHN), a model of membranous nephropathy. Fx1A is a crude extract of renal cortex that contains megalin as a principal component. However, when rats are given anti-megalin antibodies, abnormal proteinuria does not occur. Because of the established complement dependence of PHN, we hypothesized that antibodies neutralizing complement regulatory proteins in the rat glomerulus also were required to induce PHN. Two likely targets are Crry and CD59, proteins abundant on the rat podocyte and contained within Fx1A that inhibit the C3 convertase and C5b-9 assembly, respectively. METHODS: Rats were injected with anti-megalin monoclonal antibodies, followed by anti-Crry and/or anti-CD59 F(ab')(2) antibodies five days later. In a second group of experiments, rats were injected with anti-Fx1A or anti-Fx1A immunodepleted of reactivity against Crry and/or CD59. RESULTS: In the setting of podocyte-associated anti-megalin monoclonal antibodies, simultaneous neutralization of Crry and CD59 function led to the development of significant proteinuria (11.0 +/- 2.1 mg/day, P < 0.001 vs. all other groups). In contrast, animals that had neither or only one of these complement regulators inhibited had normal urinary protein excretion (< or =6 mg/day). In animals given anti-Fx1A depleted of anti-Crry and/or anti-CD59, all groups developed typical PHN, characterized by heavy proteinuria and extensive glomerular deposition of C3 and C5b-9. CONCLUSION: Crry and CD59 play an important role in restraining complement-mediated injury following subepithelial immune complex deposition; however, in PHN, their regulatory capacity is overwhelmed.


Assuntos
Ativação do Complemento , Glomerulonefrite/imunologia , Glomérulos Renais/imunologia , Animais , Antígenos de Superfície , Antígenos CD59/imunologia , Complemento C3b/análise , Complemento C3d/análise , Complemento C5/análise , Complemento C5b , Glomerulonefrite/urina , Complexo Antigênico da Nefrite de Heymann , Imunização Passiva , Imunoglobulina G/análise , Glomérulos Renais/irrigação sanguínea , Glicoproteínas de Membrana/imunologia , Ratos , Receptores de Superfície Celular , Receptores de Complemento/imunologia
11.
Am Heart J ; 142(3): 466-75, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11526360

RESUMO

BACKGROUND: Peak exercise oxygen consumption (peak VO2) is an important discriminator of survival in patients with systolic heart failure and is used to select ambulatory patients for transplantation. The major trials assessing the relationship between peak VO2 and survival have used a variety of low-level exercise protocols. It is unknown how peak VO2 measured in this patient population by the more vigorous Bruce treadmill protocol compares with that obtained on less intense protocols. METHODS: We studied 15 patients (50 +/- 12 years old) with severe heart failure (left ventricular ejection fraction 23.5% +/- 8.6%). Patients randomly performed 3 exercise tests with the Bruce treadmill, modified Naughton treadmill, and modified bicycle protocols within 14 days. To determine the ability of this patient population to perform the Bruce protocol, we also retrospectively analyzed the ability of 84 patients to perform this test on their initial evaluations at our center. RESULTS: All patients reached the anaerobic threshold (AT) on all 3 protocols. The Bruce and modified Naughton treadmill protocols resulted in similar peak VO2 percent predicted peak VO2, and VO2 at AT values (17.7 +/- 3.8 mL/kg/min, 57.2% +/- 21.1% and 15.4 +/- 4.1 mL/kg/min vs 18.0 +/- 4.7 mL/kg/min, 58.1% +/- 22.5% and 15.6 +/- 4.4 mL/kg/min, respectively). Peak VO2 and VO2 at AT on both treadmill protocols were higher than those obtained with bicycle testing (15.3 +/- 3.1 and 11.8 +/- 3.0 mL/kg/min, P <.05). Exercise duration was shorter with the Bruce and bicycle protocols (6.2 +/- 2.2 and 6.7 +/- 2.4 minutes, respectively) compared with the modified Naughton protocol (9.7 +/- 4.3 minutes, both P <.005). In addition, 79 of the 84 patients (94%) evaluated were able to complete the Bruce protocol and reach AT. CONCLUSIONS: The Bruce protocol was more time efficient than the modified Naughton protocol and yielded similar peak VO2, percent predicted peak VO2, and VO2 at AT values. Bicycle exercise may underestimate peak VO2 values. The form of exercise should be considered when assessing peak VO2 criteria for transplant listing.


Assuntos
Exercício Físico/fisiologia , Transplante de Coração , Consumo de Oxigênio , Disfunção Ventricular Esquerda/terapia , Adulto , Idoso , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Estudos Retrospectivos
12.
J Am Coll Cardiol ; 38(1): 84-90, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451301

RESUMO

OBJECTIVES: The aim of this study was to investigate the disparity between the extent of myocardial injury as assessed by thallium and the severity of left ventricular (LV) dysfunction in chronic ischemic heart disease. BACKGROUND: Although it is believed that thallium differentiates between viable and nonviable myocardium, in some patients with chronic ischemic heart disease, viable regions by thallium may fail to improve function after revascularization. METHODS: Thirteen transplant candidates with chronic ischemic heart disease (LV ejection fraction = 14 +/- 6% at rest) were studied prospectively with stress-redistribution-reinjection thallium single-photon emission computed tomography. We examined pretransplantation quantitative thallium uptake and post-transplantation extent and the histological distribution of collagen replacement in infarcted and noninfarcted myocardium and in 13 age-matched control hearts. RESULTS: The volume fraction of collagen varied inversely with wall thickness (r = -0.70, p < 0.001) and was higher in irreversible (30.9 +/- 15.8%) compared with reversible (20.2 +/- 12.6%, p < 0.001) or normal thallium segments (15.0 +/- 8.7%, p < 0.001). The irreversible thallium segments had lower wall thickness and more severe coronary artery narrowing (9.7 +/- 2.8 mm and 95 +/- 8%) compared with reversible (11.7 +/- 2.7 mm and 87 +/- 13%, p < 0.001) and normal thallium segments (12.8 +/- 2.6 mm and 80 +/- 14%, p < 0.001). Mean volume fraction of collagen was significantly lower in noninfarcted than it was in infarcted segments (13 +/- 6% vs. 36 +/- 13%, p < 0.001) but exceeded that in the control hearts (4 +/- 2%, p < 0.001). Noninfarcted segments had predominantly interstitial fibrosis with either microscopic or patchy areas of replacement fibrosis. CONCLUSIONS: In chronic ischemic heart disease with severe LV dysfunction, patterns of normal, reversible and irreversible thallium uptake correlated with the magnitude of collagen replacement, segmental wall thickness and severity of coronary artery narrowing. The finding of scattered areas of replacement fibrosis in noninfarcted myocardium may explain the observed disparity between LV contractile dysfunction and the extent of myocardial injury assessed by thallium.


Assuntos
Isquemia Miocárdica/diagnóstico por imagem , Miocárdio/patologia , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Disfunção Ventricular Esquerda/patologia , Remodelação Ventricular , Adulto , Colágeno/metabolismo , Fibrose , Imagem do Acúmulo Cardíaco de Comporta , Humanos , Pessoa de Meia-Idade , Isquemia Miocárdica/metabolismo , Miocárdio/metabolismo , Estudos Prospectivos , Distribuição Tecidual
13.
J Biol Chem ; 276(34): 32129-35, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11406620

RESUMO

Complement-coated particles interact with specific immune adherence receptors (IAR). In primates, this function is served by complement receptor 1 (CR1) on erythrocytes. In contrast, rodent platelets bear IAR distinct from CR1, the identity of which was studied here. A 150-kDa C3b-binding protein was isolated from rat platelets, which had immunochemical and biochemical identity to plasma factor H. Immunofluorescence microscopy and flow cytometry demonstrated that factor H was present on the surface of rat and mouse platelets, which could be removed by treatment with neuraminidase. Sheep erythrocytes bearing C3b underwent immune adherence with rat and mouse platelets, which was blocked with anti-factor H F(ab')(2) antibodies, but not with antibodies binding to the complement regulator, Crry, on the platelet surface. By reverse transcription-polymerase chain reaction using rat platelet RNA and primers designed from mouse factor H, a 472-base pair product was generated that was identical in sequence to that produced from rat liver RNA. The translated protein product was 85% similar to mouse liver factor H. The 3'-nucleotide sequence from platelets predicted a soluble factor H protein. By Northern analysis, liver and platelets had identically sized factor H mRNA. Thus, rat and mouse platelets have a membrane protein with characteristics of factor H that is linked via sialic acid residues and functions as the IAR. Whether platelet factor H is acquired by passive adsorption from sera and/or is produced by platelets remains to be determined.


Assuntos
Plaquetas/metabolismo , Fator H do Complemento/metabolismo , Receptores Imunológicos/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Fator H do Complemento/fisiologia , Primers do DNA , Camundongos , Dados de Sequência Molecular , Ratos , Homologia de Sequência de Aminoácidos
14.
J Cardiopulm Rehabil ; 21(3): 158-63, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11409226

RESUMO

PURPOSE: Exercise prescription in patients with left ventricular systolic dysfunction (LVSD) is difficult. Exercising beyond ventilatory threshold (VT) can have negative physiologic effects; therefore, exercise prescribed above VT may be detrimental. A majority of cardiac rehabilitation programs use the Karvonen/heart rate reserve (HRR) method, rating of perceived exertion (RPE), and/or a percentage of oxygen consumption to prescribe exercise intensity. The purpose of this study was to determine if these methods correlate with an exercise intensity below VT in LVSD patients. METHODS: The authors studied 52 patients (37 males, 15 females; age 52 +/- 13 years; left ventricular ejection fraction 27% +/- 8%) who underwent a symptom-limited cardiopulmonary exercise test and reached VT to determine functional capacity and exercise prescription. RESULTS: Peak heart rate (HR) as well as HRR derived minimum (60%), midpoint (70%), and maximum (80%) HR were highly correlated (P < 0.001) with HR at VT. Using these three different HR cutoff formulas from HRR, 15% to 62% of patients were prescribed exercise outside the range of VT-HR +/- 10%. The midpoint (70% HRR) best predicted exercise HR in the VT-HR +/- 10% range (73% of patients). Mean oxygen consumption at VT was 83 +/- 9% of peak oxygen consumption. There was no correlation (P < 0.16) between RPE and VT. CONCLUSIONS: The Karvonen/HRR method failed to estimate HR-VT +/- 10% in a large percentage of patients with LVSD. There was no correlation between RPE and VT. Based on these data, exercise training intensity should ideally be prescribed based on the HR identified at VT using cardiopulmonary exercise testing in patients with LVSD.


Assuntos
Terapia por Exercício/métodos , Exercício Físico/fisiologia , Disfunção Ventricular Esquerda/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Teste de Esforço , Terapia por Exercício/normas , Tolerância ao Exercício , Feminino , Frequência Cardíaca/fisiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Disfunção Ventricular Esquerda/fisiopatologia
15.
Echocardiography ; 17(1): 7-16, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10978954

RESUMO

Previously published data have suggested that endurance training does not retard the normative aging impairment of early left ventricular diastolic filling (LVDF). Those studies, suggesting no effect of exercise training, have not examined highly trained endurance athletes or their LVDF responses after exercise. We therefore compared LVDF characteristics in a group of older highly trained endurance athletes (n = 12, mean age 69 years, range 65-75) and a group of sedentary control subjects (n = 12, mean age 69 years, range 65-73) with no cardiovascular disease. For all subjects, M-mode and Doppler echocardiographic data were obtained at rest. After baseline studies, subjects underwent graded, maximal cardiopulmonary treadmill exercise testing using a modified Balke protocol. Breath-by-breath respiratory gas analysis and peak exercise oxygen consumption (VO(2)max) measurements were obtained. Immediately after exercise and at 3-6 minutes into recovery, repeat Doppler echocardiographic data were obtained for determination of LVDF parameters. VO(2)max (44 +/-6.3 vs 27+/-4.2 ml/kg/min, P<0.001), oxygen consumption at anaerobic threshold (35+/-5.4 vs 24+/-3.8 ml/kg/min, P<0.001), exercise duration (24+/-3 vs 12+/-6 minutes, P<0.001), and left ventricular mass index (61+/-13 vs 51+/-7.8 kg/m(2), P<0.05) were greater in endurance athletes than in sedentary control subjects, whereas body mass index was lower (22+/-1.7 vs 26+/-3.4 kg/m(2), P<0.001). No differences in any of the LVDF characteristics were observed between the groups with the exception of a trend toward a lower atrial filling fraction at rest in the endurance athlete group versus the control subjects (P = 0.07). High-intensity endurance exercise training promotes exceptional peak exercise oxygen consumption and cardiovascular stamina but does not appear to alter normative aging effects on left ventricular diastolic function.


Assuntos
Diástole/fisiologia , Ecocardiografia Doppler , Resistência Física/fisiologia , Esportes/fisiologia , Função Ventricular Esquerda/fisiologia , Função Ventricular , Idoso , Envelhecimento/fisiologia , Gasometria , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Consumo de Oxigênio
16.
Kidney Int ; 58(4): 1580-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11012892

RESUMO

BACKGROUND: Acute renal failure (ARF) in sepsis occurs when the release of multiple inflammatory mediators is induced by bacterial endotoxins. C3 mRNA is markedly up-regulated in mouse kidney after exposure to lipopolysaccharide (LPS). We hypothesized that LPS could induce tubular synthesis and secretion of C3, leading to activation of the complement cascade and direct renal tubular injury. METHODS: ARF was induced in mice by intravenous injection of LPS and was confirmed by an acute rise in blood urea nitrogen (BUN) and histologically by acute tubular necrosis. Three separate strategies were used to investigate the role of the complement system in this model of ARF: (1) Crry-Ig, a recombinant protein containing the potent murine complement C3 activation inhibitor Crry was injected at the same time as LPS (N = 8). (2) LPS was injected into transgenic mice overexpressing Crry in glomeruli and tubules (N = 8), and (3) LPS was injected into C3-deficient mice (N = 5). RESULTS: Compared with unmanipulated mice, C3 staining by immunofluorescence (IF) microscopy in mice injected with LPS was greater in renal cortical tubular cells (IF score of 2. 1 +/- 0.1 vs. 1.4 +/- 0.2 in controls, P = 0.013), most prominently at the basolateral surface. LPS injection led to a 16- to 42-fold increase in urinary C3 excretion. Despite reduction or complete elimination of renal C3 with maneuvers suppressing complement activation, BUN values were not statistically different across all groups. In no experiment did BUN values correlate with the extent of C3 staining. CONCLUSION: Although LPS up-regulates renal C3 synthesis, resulting in basolateral tubular C3 deposition, this is not responsible for LPS-induced ARF in mice.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/imunologia , Ativação do Complemento/imunologia , Complemento C3/urina , Receptores de Lipopolissacarídeos/farmacologia , Injúria Renal Aguda/etiologia , Albuminúria , Animais , Ativação do Complemento/efeitos dos fármacos , Complemento C3/genética , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Glomérulos Renais/imunologia , Glomérulos Renais/metabolismo , Camundongos , Camundongos Knockout , Receptores de Complemento/genética , Receptores de Complemento 3b , Proteínas Recombinantes de Fusão/genética , Sepse/complicações
17.
Pacing Clin Electrophysiol ; 23(3): 338-43, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10750134

RESUMO

The Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) is a multicenter randomized trial. Patients will have nonischemic cardiomyopathy (LVEF < or = 35%), a history of symptomatic heart failure and spontaneous arrhythmia (> 10 PVCs/hour or nonsustained ventricular tachycardia defined as 3-15 beats at a rate of > 120 beats/min) on Holter monitor or telemetry within the past 6 months. Patients will be randomized to an implantable cardioverter defibrillator (ICD) versus no ICD. All patients will receive standard oral medical therapy for heart failure including angiotensin converting enzyme inhibitors and beta-blockers (if tolerated). Patients will be followed for 2-3 years. The primary endpoint will be total mortality. Quality-of-life and pharmacoeconomics analyses will also be performed. A registry will track patients who meet basic inclusion criteria but are not randomized. We estimate an annual total mortality of 15% at 2 years in the treatment arm that does not receive an ICD. The ICD is expected to reduce mortality by 50%. Approximately 204 patients will be required in each treatment group. Twenty-five centers will be included in a trial designed to last an estimated 4 years.


Assuntos
Cardiomiopatia Dilatada/terapia , Desfibriladores Implantáveis , Cardiomiopatia Dilatada/etiologia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Taquicardia Ventricular/complicações , Taquicardia Ventricular/tratamento farmacológico
18.
Am Heart J ; 139(1 Pt 1): 15-22, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10618557

RESUMO

BACKGROUND: The optimal management of an acute exacerbation of chronic heart failure (CHF) is uncertain. There is little randomized evidence available to support the various treatment strategies for patients hospitalized with an exacerbation of CHF. Inotropic agents may produce beneficial hemodynamic effects, and although they are currently used in these patients, their effect on clinical response and impact on clinical outcome is unclear. We present a unique and simple study designed to determine whether a treatment strategy for CHF exacerbations that includes an intravenous agent with inotropic properties can reduce hospital length of stay and lead to improved patient outcome. METHODS: The OPTIME CHF (Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations of Chronic Heart Failure) trial is an ongoing multicenter, randomized, placebo-controlled trial of a treatment strategy for patients with acute exacerbations of CHF. The design of this study provides a novel approach to the evaluation of treatment strategies in the care of this population. The OPTIME CHF design uses early initiation of intravenous milrinone as both an adjunct to the best the medical therapy and to facilitate optimal dosing of standard oral therapy for heart failure. Patients with known systolic heart failure requiring hospital admission for a CHF exacerbation are randomly assigned within 48 hours of admission to receive a 48-hour infusion of either intravenous milrinone or placebo. The primary end point of this design is a reduction in the total hospital days for cardiovascular events within 60 days after therapy. Enrollment of 1000 patients began July 7, 1997, at 80 US centers and is projected to conclude in late 1999.


Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Milrinona/administração & dosagem , Inibidores de Fosfodiesterase/administração & dosagem , Adolescente , Análise Custo-Benefício , Feminino , Insuficiência Cardíaca/economia , Insuficiência Cardíaca/mortalidade , Mortalidade Hospitalar , Humanos , Injeções Intravenosas , Tempo de Internação , Masculino , Estudos Prospectivos , Qualidade de Vida , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia
19.
Immunology ; 99(1): 46-53, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10651940

RESUMO

Crry (CR1-related gene/protein) is a rodent complement regulator that inhibits C3 convertases. CD59 is a conserved protein inhibitor active towards C8 and C9. We have previously produced rat Crry as a recombinant soluble (rs) protein in Pichia pastoris. In this study we produced functionally active rat rsCD59 and a chimeric rsCD59-Crry protein in P. pastoris. The GPI anchor addition site of rat CD59 (Asn-79) was replaced either by a stop codon to produce rsCD59, or with the sequence of the first five short consensus repeats of Crry to produce rsCD59-Crry. Proteins were generated by fermentation and purified by affinity chromatography on an anti-CD59 column. In a standard classical pathway haemolysis assay, all three rs proteins had inhibitory activity, with 50% inhibition at 0.5 microM (rsCrry and rsCD59-Crry) and 4.4 microM (rsCD59). In an assay examining inhibition of C5b-9, in which C5b-7 was first formed, followed by purified C8 and C9, rsCD59 and rsCD59-Crry were active with 50% inhibition at 0.8 microM (rsCD59-Crry) and 1.3 microM (rsCD59). The degree of inhibition was independent of whether the C8 and C9 were of rat or human origin. Therefore, we have produced rsCD59 and rsCD59-Crry in P. pastoris. The rsCD59 retains its inhibitory activity towards C5b-9, while rsCD59-Crry appears to have the combined activities of Crry and CD59. In a haemolytic assay, the inclusion of CD59 to Crry is of no additional benefit to Crry, which may illustrate the overall importance of the C3 convertase step. Yet, inclusion of Crry to CD59 increases the potency of CD59 towards C5b-9.


Assuntos
Antígenos CD59/biossíntese , Proteínas Inativadoras do Complemento , Pichia/metabolismo , Receptores de Complemento/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes/biossíntese , Animais , Antígenos de Superfície , Antígenos CD59/análise , Antígenos CD59/imunologia , Fermentação , Hemólise/efeitos dos fármacos , Immunoblotting , Ratos , Receptores de Superfície Celular , Receptores de Complemento/análise , Receptores de Complemento/imunologia
20.
Congest Heart Fail ; 6(4): 202-214, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12147954

RESUMO

Patients with severe systolic heart failure have a decrease in both number and function of cardiac beta receptors, which may result in a poor inotropic response to I.V. beta-adrenergic agonists such as dobutamine. The I.V. use of the phosphodiesterase inhibitor milrinone, which is a combined positive inotrope/vasodilator in this patient population, is a more rational choice, especially if heart failure is chronic. Many of these patients may also be referred for consideration for cardiac transplantation, for which the use of invasive hemodynamic monitoring is typically necessary to determine whether severe hemodynamic compromise and pulmonary hypertension are reversible with therapy. The use of hemodynamically guided I.V. vasodilator therapy has also been extensively described as a tool to optimize oral vasodilator therapy and predict prognosis in patients evaluated for cardiac transplantation. This review summarizes the important studies supporting the rationale for and benefits of using I.V. milrinone under hemodynamic guidance in this patient population. (c)2000 by CHF, Inc.

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