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1.
Phys Rev Lett ; 122(18): 181102, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31144869

RESUMO

In this paper, we present the analysis and results of a direct measurement of the cosmic-ray proton spectrum with the CALET instrument onboard the International Space Station, including the detailed assessment of systematic uncertainties. The observation period used in this analysis is from October 13, 2015 to August 31, 2018 (1054 days). We have achieved the very wide energy range necessary to carry out measurements of the spectrum from 50 GeV to 10 TeV covering, for the first time in space, with a single instrument the whole energy interval previously investigated in most cases in separate subranges by magnetic spectrometers (BESS-TeV, PAMELA, and AMS-02) and calorimetric instruments (ATIC, CREAM, and NUCLEON). The observed spectrum is consistent with AMS-02 but extends to nearly an order of magnitude higher energy, showing a very smooth transition of the power-law spectral index from -2.81±0.03 (50-500 GeV) neglecting solar modulation effects (or -2.87±0.06 including solar modulation effects in the lower energy region) to -2.56±0.04 (1-10 TeV), thereby confirming the existence of spectral hardening and providing evidence of a deviation from a single power law by more than 3σ.

2.
Phys Rev Lett ; 120(26): 261102, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004739

RESUMO

Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X_{0} at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below 1 TeV shows good agreement with Alpha Magnetic Spectrometer (AMS-02) data. In the energy region below ∼300 GeV, CALET's spectral index is found to be consistent with the AMS-02, Fermi Large Area Telescope (Fermi-LAT), and Dark Matter Particle Explorer (DAMPE), while from 300 to 600 GeV the spectrum is significantly softer than the spectra from the latter two experiments. The absolute flux of CALET is consistent with other experiments at around a few tens of GeV. However, it is lower than those of DAMPE and Fermi-LAT with the difference increasing up to several hundred GeV. The observed energy spectrum above ∼1 TeV suggests a flux suppression consistent within the errors with the results of DAMPE, while CALET does not observe any significant evidence for a narrow spectral feature in the energy region around 1.4 TeV. Our measured all-electron flux, including statistical errors and a detailed breakdown of the systematic errors, is tabulated in the Supplemental Material in order to allow more refined spectral analyses based on our data.

3.
Phys Rev Lett ; 119(18): 181101, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29219544

RESUMO

First results of a cosmic-ray electron and positron spectrum from 10 GeV to 3 TeV is presented based upon observations with the CALET instrument on the International Space Station starting in October, 2015. Nearly a half million electron and positron events are included in the analysis. CALET is an all-calorimetric instrument with total vertical thickness of 30 X_{0} and a fine imaging capability designed to achieve a large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum over 30 GeV can be fit with a single power law with a spectral index of -3.152±0.016 (stat+syst). Possible structure observed above 100 GeV requires further investigation with increased statistics and refined data analysis.

4.
Sarcoidosis Vasc Diffuse Lung Dis ; 30(1): 36-42, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24003533

RESUMO

Several susceptibility genes for sarcoidosis have been identified, but their relationship to the clinical state and prognosis remains to be elucidated. The aim of this study was to elucidate the relationship between sarcoidosis and five single nucleotide polymorphisms (SNPs) of three cytokines expected to play an important role in the inflammatory response. A case-control study was performed with 208 unrelated patients who met the diagnostic criteria for sarcoidosis used in Japan since 2006, and 328 control subjects. Five SNPs were analyzed: interleukin (IL)-10-819T/C (rs1800871), IL-10-592A/C(rs1800872), IL-6-634C/G (rs1800796), tumor necrosis factor-alpha (TNF-alpha)-857C/T (rs1799724), and TNF-alpha -1031T/C (rs1799964). No significant differences in SNPs were observed between the total sarcoidosis and control groups. However, the prevalence of rs1800871 and rs1800872 polymorphisms differed significantly in the sarcoidosis with eye involvement group compared with the control group [rs1800871 TT (vs. TC + CC): OR = 1.67, P = 0.034; rs1800872 AA (vs. AC + CC): OR = 1.66, P = 0.036]. Analyzing the cardiac involvement group, the prevalence of the rs1799724 polymorphism was significantly different from that of the control group [rs1799724 TT (vs. CC + CT): OR = 6.01. P = 0.006]. We concluded that the rs1799724 C/T polymorphism may affect susceptibility to cardiac sarcoidosis, while the rs1800871 T/C and rs1800872A/C polymorphisms may affect susceptibility to sarcoidosis with eye involvement.


Assuntos
Cardiomiopatias/genética , Citocinas/genética , Sarcoidose/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Suscetibilidade a Doenças , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genética , Adulto Jovem
5.
Redox Rep ; 12(4): 189-94, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17705989

RESUMO

Reactions of 3-methyl-1-phenyl-2-pyrazoline-5-one (MCI-186) with hypochlorous acid and superoxide were analysed by spectrophotometry and mass spectrometry. The results were applied to the neutrophil system to evaluate the scavenging activity of neutrophil-derived active oxygen species by MCI-186. MCI-186 reacted rapidly with hypochlorous acid (1 x 10(6) M(-1)s(-1)) to form a chlorinated intermediate, followed by a slow conversion to a new spectrum. MCI-186 consumed 3 moles of hypochlorous acid and did not react with superoxide. The newly synthesized fluorescence probes, 2-[6-(4'-amino)-phenoxy-3H-xanthen-3-on-9-yl]benzoic acid (APF) and 2-[6-(4'-hydroxy)phenoxy-3H-anthen-3-on-9-yl]benzoic acid (HPF) successfully detected neutrophil-derived active oxygens (Setsukinai K, Urano Y, Kakinuma K, Majima HJ, Nagano T. Development of novel fluorescence probes that can reliably detect reactive oxygen species and distinguish specific species. J Biol Chem 2003; 278: 3170-3175). The rate constants for the reaction of hypochlorous acid with MCI-186 and fluorescence probes was in the order of MCI-186 > APF > HPF. Fluorescence due to the oxidation of APF and HPF was observed with the stimulated neutrophils. The result that the intensity from APF oxidation was higher than that from HPF oxidation is compatible with reports that APF selectively reacts with hypochlorous acid. Fluorescence due to oxidation of both APF and HPF decreased when the reactions were carried out in the presence of a fluorescence probe and MCI-186 in a dose-dependent manner. These results indicate that MCI-186 effectively scavenges neutrophil-derived hypochlorous acid and other active oxygens.


Assuntos
Antipirina/análogos & derivados , Ácido Hipocloroso/química , Neutrófilos/química , Espécies Reativas de Oxigênio/química , Antipirina/química , Antipirina/farmacologia , Edaravone , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Ácido Hipocloroso/metabolismo , Medições Luminescentes/métodos , Luminol/química , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espectrofotometria/métodos , Superóxidos/química , Fatores de Tempo
8.
J Cardiol ; 38(1): 13-20, 2001 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-11496431

RESUMO

OBJECTIVES: This clinical study investigated the prevalence of cervical and cerebral atherosclerosis and silent brain infarction in patients with coronary artery disease. METHODS: Cervical and cerebral magnetic resonance angiography(MRA) was performed in 133 patients (98 males, 35 females, mean age 65.3 years) with suspected coronary artery disease, who were divided into a zero- and one-vessel disease group(n = 71) and a two- and three-vessel disease group(n = 62) depending on the number of major coronary branches with 75% or more stenosis. The MRA lesion was defined as more than 50% stenosis. Magnetic resonance imaging(MRI) of the brain was performed within 1 week of MRA in 78 patients without symptomatic stroke and atrial fibrillation. Silent brain infarction on MRI was defined as a focal high intensity area on T2-weighted images larger than 3 mm. RESULTS: The prevalence of MRA lesions was significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(53% vs 14%, p < 0.01). The prevalence of MRI lesion was significantly higher in the two- and three-vessel group than in the zero- and one-vessel group(77% vs 36%, p < 0.01). The size and number of the MRI lesions were also significantly greater in the two- and three-vessel group than in the zero- and one-vessel group(p < 0.01). Neither age nor percentage of male gender was different between the groups. Diabetes mellitus was the common risk factor for coronary artery disease, MRA lesion and MRI lesion. CONCLUSIONS: Cervical and cerebral atherosclerosis and silent brain infarction are frequently observed in patients with multivessel coronary artery disease.


Assuntos
Arteriosclerose/complicações , Doenças das Artérias Carótidas/complicações , Infarto Cerebral/complicações , Doença das Coronárias/complicações , Arteriosclerose Intracraniana/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prevalência
9.
Circulation ; 104(4): 455-60, 2001 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-11468209

RESUMO

BACKGROUND: Cytokines induce apoptosis in vascular disease lesions through enhancement of inducible nitric oxide (NO) synthase (iNOS) activation. The thiazolidinediones, novel insulin-sensitizing agents, have been demonstrated to modulate cytokine-induced NO production. We have investigated the role of pioglitazone in the apoptosis of vascular smooth muscle cells (VSMCs) in vitro and developed intimal hyperplasia in vivo. METHODS AND RESULTS: Pioglitazone (0.1 to 10 micromol/L) significantly enhanced cytokine-induced expression of iNOS and NO production in a dose-dependent manner in rat VSMCs, but 15-deoxy-Delta(12,14)-prostaglandin J2 (up to 10 micromol/L), a native peroxisome proliferator-activated receptor-gamma ligand, showed no effect. Pioglitazone also significantly enhanced reduction of cell viability, as evidenced by the increase in the number of TUNEL-positive cells. All of these effects of pioglitazone were blocked by treatment with N-monomethyl-L-arginine, an NO synthesis inhibitor. In an in vivo study with a balloon-injured rat carotid artery, neointimal thickness had reached maximum levels at 2 weeks after injury. Then, rats were fed with or without pioglitazone (3 mg. kg(-1). d(-1)) for an additional week. The ratio of intima to media area of carotid artery was significantly decreased by 30%, and the ratio of apoptotic cells in neointima was significantly increased in pioglitazone-treated rats compared with vehicle-treated control rats. CONCLUSIONS: Pioglitazone enhanced apoptosis in an NO-dependent manner in cytokine-activated VSMCs and induced significant regression of intimal hyperplasia in balloon-injured rat carotid artery. It appears that pioglitazone is a potent apoptosis inducer in vascular lesions, providing a novel pharmacological strategy to prevent restenosis after vascular intervention.


Assuntos
Apoptose/efeitos dos fármacos , Citocinas/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Tiazóis/farmacologia , Tiazolidinedionas , Túnica Íntima/efeitos dos fármacos , Animais , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/patologia , Lesões das Artérias Carótidas/etiologia , Lesões das Artérias Carótidas/patologia , Lesões das Artérias Carótidas/prevenção & controle , Cateterismo/efeitos adversos , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Hiperplasia/prevenção & controle , Marcação In Situ das Extremidades Cortadas , Interferon gama/farmacologia , Interleucina-1/farmacologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/efeitos dos fármacos , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Pioglitazona , Ratos , Ratos Sprague-Dawley , Túnica Íntima/patologia , ômega-N-Metilarginina/farmacologia
10.
J Nucl Med ; 42(7): 1017-24, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11438621

RESUMO

UNLABELLED: The objective of this study was to clarify the relationship between cardiac sympathetic nervous function (CSNF) and left ventricular (LV) function and perfusion in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). METHODS: Thirty-eight cases (32 males, 6 females; mean age, 56 +/- 15 y), consisting of 5 healthy control subjects, 15 patients with DCM, and 18 patients with HCM, were studied with (123)I-metaiodobenzylguanidine (MIBG) and (99m)Tc-tetrofosmin SPECT. CSNF was evaluated from cardiac uptake and washout of MIBG, whereas LV perfusion and function were evaluated from tetrofosmin uptake and wall thickening on electrocardiographically gated SPECT. As quantitative parameters of global cardiac MIBG uptake and washout, the heart-to-mediastinum ratio (H/M) and percentage washout were calculated from early and delayed planar images. As quantitative regional parameters, the regional uptake and percentage washout of MIBG were calculated from SPECT images dividing the left ventricle into 12 segments. In the tetrofosmin study, the H/M and LV ejection fraction were calculated as the parameters of global LV perfusion and function. As quantitative regional parameters, the regional uptake and wall thickening were also calculated for the 12 myocardial segments using the quantitative gated SPECT software. Multiple linear regression analysis was performed to investigate the correlations between the parameters from the 2 studies. RESULTS: In DCM and HCM, multiple linear regression analysis of the regional parameters showed significant correlations between LV function and CSNF (P < 0.0001) and between LV perfusion and CSNF (P < 0.0001). According to the partial correlation coefficients, washout and early uptake of MIBG were the most significant factors for predicting LV function and LV perfusion, respectively. CONCLUSION: In cardiomyopathies, CSNF was closely related to LV function. The quantitative parameters of MIBG washout could reflect cardiac functional impairment. Early MIBG uptake might be determined by myocardial perfusion in cardiomyopathies.


Assuntos
3-Iodobenzilguanidina , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Hipertrófica/fisiopatologia , Circulação Coronária , Coração/inervação , Radioisótopos do Iodo , Compostos Organofosforados , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Sistema Nervoso Simpático/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular Esquerda , Adolescente , Adulto , Idoso , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Nihon Rinsho ; 59(5): 949-54, 2001 May.
Artigo em Japonês | MEDLINE | ID: mdl-11391997

RESUMO

The management of hypertensive patients with coronary artery disease (CAD) should be started with lifestyle modification for reduction of coronary risk factors. As the principle of drug therapy, rapid decrease in blood pressure below the limits of coronary auto-regulation must be avoided. Clinical trials showed J-curved relationship between diastolic pressure and mortality was not found above 75 mmHg. The current desired goal of blood pressure in patients with CAD might be suggested as 125-140/85-75 mmHg. Pulse pressure should be recognized as a strong predictor for CAD as well as systolic and diastolic blood pressure, especially in elderly patients. The choice of drug therapy have to be based on efficiency in clinical trials, side effects, and also particular condition of each patient.


Assuntos
Anti-Hipertensivos/administração & dosagem , Doença das Coronárias/complicações , Hipertensão/terapia , Pressão Sanguínea , Doença das Coronárias/fisiopatologia , Doença das Coronárias/terapia , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia
12.
Am J Physiol Heart Circ Physiol ; 280(3): H1361-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179085

RESUMO

On the hypothesis that coronary sinus occlusion (CSO) may reduce myocardial ischemia, we examined the effects of CSO on coronary collateral blood flow and on the distribution of regional myocardial blood flow (RMBF) in dogs. Thirty-eight anesthetized dogs underwent occlusion of the left anterior descending coronary artery with or without CSO and intact vasomotor tone. We measured RMBF and intramyocardial pressure (IMP) in the subendocardium (Endo) and subepicardium (Epi) separately. With intact vasomotor tone, CSO during ischemia significantly increased RMBF in the ischemic region (IR), particularly in Endo from 0.17 +/- 0.03 to 0.33 +/- 0.05 ml x min(-1) x g(-1) (P < 0.05), and increased the Endo/Epi from 0.59 +/- 0.10 to 1.15 +/- 0.15 (P < 0.01). These effects of CSO were partially abolished by adenosine. However, the Endo/Epi was still increased from 0.90 +/- 0.13 to 2.09 +/- 0.30 (P < 0.01). The changes in RMBF in IR were significantly correlated with the peak CS pressure during CSO. The Endo/Epi of IMP in IR was significantly decreased during CSO. In conclusion, CSO potentially enhances coronary collateral flow, and preserves the ischemic myocardium, especially in Endo.


Assuntos
Circulação Colateral/fisiologia , Circulação Coronária/fisiologia , Doença das Coronárias/fisiopatologia , Endocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Adenosina/farmacologia , Anestesia , Animais , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Cães , Frequência Cardíaca/fisiologia , Hiperemia/fisiopatologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/farmacologia , Pressão Ventricular/fisiologia
13.
Atherosclerosis ; 155(1): 171-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11223439

RESUMO

A high incidence of acute myocardial infarction (AMI) has been reported between 06:00 and 12:00 h. This may be related to an abnormality in hemostasis. An association has been founded between the serum lipid level and coronary atherosclerosis, as well as the serum lipid level and a hemostatic abnormality. We investigated the association between the time of AMI, the level of serum lipid, and of hemostatic factor. Of the 42 subjects evaluated retrospectively, 20 had experienced an AMI between 06:00 and 12:00 h (group A), while 22 had developed an AMI during some other period (group B). All patients received emergency coronary angiography, which identified a total occlusion of coronary artery in the proximal portion of the left antecedent branch. The serum level of several lipid factors and of hemostatic factors were compared between the two groups. Characteristics of patients were similar in both groups. The serum levels of lipoprotein(a) (Lp(a)) and of thrombin-antithrombin III complex (TAT) were higher in group A than in group B, respectively. The level of other factors were similar in both groups. Group A showed a significant correlation between the level of Lp(a) and TAT, with a tendency (not statistically significant), toward a positive correlation between Lp(a) and PAI-1, and a negative correlation between Lp(a) and t-PA. In a subgroup that experienced AMI in the early morning, a higher level of Lp(a) was associated with an elevation of TAT, a marker for thrombin generation, and with the level of fibrinolytic factor. This suggests that Lp(a) is closely related to the increase in the early morning incidence of AMI via a change in the prothrombotic state.


Assuntos
Ritmo Circadiano , Lipoproteína(a)/sangue , Infarto do Miocárdio/sangue , Peptídeo Hidrolases/sangue , Antitrombina III , Angiografia Coronária , Feminino , Hemostasia , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Inibidor 1 de Ativador de Plasminogênio/sangue , Estudos Retrospectivos , Ativador de Plasminogênio Tecidual/sangue
14.
J Cardiovasc Pharmacol ; 38 Suppl 1: S63-7, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11811362

RESUMO

We examined whether angiotensin converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor blockers (ARB) prevent isoproterenol (ISO)-induced left ventricular (LV) dysfunction in dogs. The effects of a large dose of ISO, 1 microg/kg/min, 3 h infusion, were investigated in three groups with simultaneous infusion of an ACE inhibitor (quinaprilat), ARB (candesartan) or saline. ISO infusion significantly decreased LV dP/dt, LV ejection fraction and LV fractional shortening, and significantly increased tau, the time constant of isovolume relaxation of LV, and LV end diastolic pressure. All of these changes were significantly attenuated in both the ACE inhibitor and ARB groups, especially in the ARB group. Serum levels of creatinin kinase isoform MB, lactate dehydrogenase and lipid peroxide were significantly increased by ISO. However, the increases in these markers of myocardial damage were significantly diminished by simultaneous infusion of an ACE inhibitor or ARB, especially by ARB. In conclusion, an ACE inhibitor and ARB prevent LV systolic and diastolic dysfunction as well as myocardial damage induced by excess beta-adrenergic stimulation.


Assuntos
Angiotensina II/metabolismo , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Cardiopatias/induzido quimicamente , Cardiopatias/prevenção & controle , Isoproterenol/administração & dosagem , Disfunção Ventricular Esquerda/prevenção & controle , Agonistas Adrenérgicos beta/administração & dosagem , Angiotensina II/sangue , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Creatina Quinase/sangue , Creatina Quinase Forma MB , Cães , Feminino , Cardiopatias/tratamento farmacológico , Hemodinâmica/efeitos dos fármacos , Isoenzimas/sangue , L-Lactato Desidrogenase/sangue , Peróxidos Lipídicos/sangue , Masculino , Receptor Tipo 1 de Angiotensina , Disfunção Ventricular Esquerda/induzido quimicamente , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/fisiopatologia
15.
Hypertens Res ; 23(6): 607-12, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11131273

RESUMO

The present study was designed to evaluate the effects of an ACE inhibitor, lisinopril, and a calcium antagonist, nitrendipine, on urinary albumin excretion (UAE) and renal function in mild to moderate essential hypertensive patients with microalbuminuria. After the 4-week drug-free period, 17 patients were randomly divided into two groups. The first group (group 1: n=8) received lisinopril 10-20 mg daily for 8 weeks followed by nitrendipine 5-10 mg daily for another 8 weeks. The second group (group 2: n=9) received nitrendipine 5-10 mg daily for 8 weeks followed by lisinopril 10-20 mg daily for another 8 weeks. The mean blood pressure (MBP) significantly decreased in a similar manner in both groups. UAE significantly decreased after 8 weeks of treatment with lisinopril in group 1 and after 8 weeks of subsequent treatment with lisinopril in group 2. On the other hand, UAE was not altered by treatment with nitrendipine. The changes in UAE were significantly correlated with changes in MBP after 8 weeks of treatment with nitrendipine, but not after 8 weeks of treatment with lisinopril. No significant changes in creatinine clearance, urinary excretion of sodium or urinary N-acetyl-beta-D-glucosaminide were observed by any treatment in either group. These results suggest that lisinopril, not nitrendipine, reduces UAE in essential hypertensive patients with microalbuminuria independently of its effective antihypertensive properties.


Assuntos
Albuminúria/urina , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Hipertensão/fisiopatologia , Hipertensão/urina , Rim/fisiopatologia , Lisinopril/uso terapêutico , Nitrendipino/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Feminino , Humanos , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
16.
J Hypertens ; 18(10): 1457-64, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11057434

RESUMO

BACKGROUND: Abnormalities in the vascular function of insulin are observed in insulin resistance, and hyperglycaemia is one of the important factors inducing insulin resistance. OBJECTIVE: To investigate the role of glucose in the interaction of insulin and beta-adrenergic signalling systems in vascular smooth muscle cells (VSMC). METHODS: After cells were treated with D-glucose (525 mmol/l) and insulin (100 nmol/l), adenylyl cyclase activity was measured in the presence of isoproterenol, forskolin, and cholera toxin. Assays for insulin-induced activities of insulin receptor substrate (IRS)-1, phosphoinositide 3-kinase (PI3-K) and mitogen-activated protein kinase (MAPK) were performed. RESULTS: In the presence of low glucose concentrations (5 mmol/l), insulin enhanced isoproterenol-, forskolin- and cholera toxin-stimulated adenylyl cyclase activities. This stimulatory effect was abolished by PI3-K inhibitors, wortmannin, or LY294002. In contrast, in the presence of high glucose concentrations (25 mmol/l), insulin attenuated isoproterenol-stimulated activity but not cholera toxin- or forskolin-stimulated activity. Insulin-stimulated activities of IRS-1 and PI3-K, but not MAPK activity, were also attenuated in the presence of high concentrations of glucose. The MAPK kinase inhibitor, PD98059, abolished the inhibitory effect of insulin on the beta-adrenergic signalling system. Troglitazone and pioglitazone prevented this inhibitory effect of insulin by restoring IRS-1 and PI3-K activities. CONCLUSIONS: In the presence of low glucose concentrations, insulin stimulates the beta-adrenergic signalling system through the IRS-1/PI3-K pathway. However, in the presence of high glucose concentrations, the effect of insulin is switched to an inhibitory one, through the MAPK pathway. Our finding suggests that high glucose concentrations modify the cross-talk between insulin and the beta-adrenergic signalling systems in VSMC.


Assuntos
Glucose/farmacologia , Insulina/farmacologia , Músculo Liso Vascular/metabolismo , Receptores Adrenérgicos beta/fisiologia , Tiazolidinedionas , Animais , Células Cultivadas , Cromanos/farmacologia , Proteínas Substratos do Receptor de Insulina , Resistência à Insulina , Isoproterenol/farmacologia , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Músculo Liso Vascular/citologia , Fosfatidilinositol 3-Quinases/fisiologia , Fosfoproteínas/fisiologia , Ratos , Ratos Sprague-Dawley , Tiazóis/farmacologia , Troglitazona
18.
Biochim Biophys Acta ; 1497(2): 244-52, 2000 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-10903429

RESUMO

The mechanisms for the effect of hyperglycemia on insulin-induced mitogenesis were investigated using rat vascular smooth muscle cells (VSMC). VSMC were preincubated in serum-free medium with low (5 mM) glucose (LG condition) or high (25 mM) glucose (HG condition), and examined for DNA synthesis using bromodeoxyuridine (BrdUrd) incorporation. Mitogen-activated protein kinase (MAPK) activity and MAPK phosphatase (MKP-1) protein expression were detected by Western blot analysis. Phosphatidylinositol 3-kinase (PI-3K) activity was detected by thin layer chromatography. Insulin induced a dose-dependent increase in BrdUrd incorporation (123.3+/-2.6% over basal level with 1 microM insulin) in the LG group and this effect was significantly enhanced (161.6+/-10.4% over basal level) in the HG group. In the LG group, MAPK activity was transient with a peak activation (137.4+/-11.2% over basal level) after 10 min exposure to 100 nM insulin. In the HG group, the MAPK activity was significantly potentiated (two-fold compared to the LG group) and was sustained even after 60 min. Insulin also induced PI-3K activity and MKP-1 expression, both of which were blocked by the PI-3K inhibitor wortmannin. In the HG group, insulin-induced PI-3K and MKP-1 expression was almost abolished. In conclusion, high glucose enhances insulin-induced mitogenesis associated with the potentiation of insulin-stimulated MAPK activity in VSMC. These effects of glucose might in part be due to the attenuation of MKP-1 expression through the blockage of the insulin-PI-3K signal pathway.


Assuntos
Proteínas de Ciclo Celular , Glucose/farmacologia , Proteínas Imediatamente Precoces/biossíntese , Músculo Liso Vascular/efeitos dos fármacos , Fosfoproteínas Fosfatases , Proteínas Tirosina Fosfatases/biossíntese , Animais , Células Cultivadas , DNA/biossíntese , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Fosfatase 1 de Especificidade Dupla , Insulina , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Fosfatase 1 , Ratos , Transdução de Sinais
19.
Intern Med ; 39(3): 256-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10772132

RESUMO

We report the case of a 62-year-old man with nephrotic syndrome associated with stage B chronic lymphocytic leukemia (CLL). Kappa Bence Jones proteinuria and the glomerular deposition of kappa-light chain were observed. Although treatment with cyclophosphamide and prednisolone tended to reduce the level of proteinuria, the administration of angiotensin-converting enzyme inhibitor, enalapril, resulted in complete remission of nephrotic syndrome.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Imunossupressores/uso terapêutico , Leucemia Linfocítica Crônica de Células B/complicações , Síndrome Nefrótica/tratamento farmacológico , Biópsia , Ciclofosfamida/uso terapêutico , Quimioterapia Combinada , Enalapril/uso terapêutico , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/etiologia , Síndrome Nefrótica/patologia , Prednisolona/uso terapêutico , Indução de Remissão
20.
J Cardiovasc Pharmacol ; 36 Suppl 2: S55-60, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11206722

RESUMO

We examined the dose responses to continuous infusion of isoproterenol (ISO) and norepinephrine (NE) in normal (control) and procainamide-induced heart failure dogs with or without inhalation of 70 ppm nitric oxide (NO). Inhaled NO affected neither left ventricular (LV) function nor hemodynamics at baseline in both control and heart failure dogs. There were no significant differences in the responses to ISO and NE with or without inhaled NO in the control. The responses of LV dP/dt to ISO and NE were significantly enhanced in heart failure; however, they were not affected by inhaled NO. In contrast, LV pressure and dimension at end diastole were significantly increased, and pulmonary vascular resistance (PVR) was significantly decreased by inhaled NO during infusion of both ISO and NE in heart failure. In conclusion, the positive inotropic response to cathecholamine is not affected by inhaled NO even in heart failure. Inhaled NO decreases PVR, but potentially increases LV preload in the presence of additional stress of cathecholamine in heart failure.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Isoproterenol/farmacologia , Óxido Nítrico/farmacologia , Norepinefrina/farmacologia , Administração por Inalação , Animais , Cães , Óxido Nítrico/administração & dosagem , Função Ventricular Esquerda/efeitos dos fármacos
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