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1.
Phys Chem Chem Phys ; 21(13): 7183-7195, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30888381

RESUMO

Cathode materials with highly reactive surfaces and long-term stability are required to achieve high-performance solid oxide fuel cells (SOFCs). In this study, a promising cathode material, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), was prepared as a nanostructured thin film using pulsed laser deposition (PLD) on gadolinia-doped ceria (GDC)-buffered YSZ single crystal substrates having (100) and (111) orientations. Characterization revealed intrinsic differences among the as-grown LSCF thin films in terms of dominant crystalline orientation and nanostructure depending on GDC preparation as well as the YSZ substrate orientation. Evaluation of the oxygen exchange properties using the isotope exchange depth profile method revealed that LSCF thin films grown on (111) GDC/YSZ exhibited higher values of the apparent surface exchange coefficient compared to LSCF thin films grown on (100) GDC/YSZ. However, when subjected to long-term annealing at high temperatures, the former exhibited a stronger tendency to surface segregation as compared to the latter. These behaviors are correlated with the intrinsic properties of LSCF thin films, including the nanostructure, the possible effects attributed to SrO activity, and the stability of perovskite surfaces which would drive surface segregation. These results have implications for tailoring the performance of cathode thin films by understanding the dependence of oxygen exchange properties and surface segregation on driving forces such as surface chemistry and nanostructure.

2.
Lupus ; 27(2): 225-234, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28659045

RESUMO

The objective of this study is to identify the effects of statins and risk factors for thrombosis in patients with new onset of systemic lupus erythematosus (SLE) with or without antiphospholipid antibodies (aPL). Consecutive patients with SLE without history of thrombotic events were retrospectively enrolled from April 1997 to February 2014. The development of first thrombosis and death caused by thrombosis were defined as the study endpoint. Risk and protective factors for developing thrombosis were analyzed. A total of 152 patients, 80 positive and 72 negative for aPL, were included. In aPL-positive patients, 15 developed arterial ( n = 6) and venous ( n = 9) thrombosis (median follow-up period 69 months). Cox's proportional hazards model showed that older age at SLE onset and IgG-anticardiolipin antibodies (aCL) were statistically significant risks for thrombosis. Statin therapy was identified as a statistically significant protective factor against thrombosis (hazard ratio 0.12, 95% confidence interval 0.01-0.98). In aPL-negative patients (median follow-up period 46 months), seven patients developed thrombosis (five arterial and two venous). No risk factors for thrombosis were found in this group. In aPL-positive patients with SLE, the late disease onset and the presence of IgG-aCL represented additional risk factors for thrombosis. Statin treatment appeared as a protective factor for thrombosis.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lúpus Eritematoso Sistêmico/complicações , Trombose/tratamento farmacológico , Trombose/etiologia , Adulto , Anticorpos Anticardiolipina/imunologia , Anticorpos Antifosfolipídeos/imunologia , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Japão/epidemiologia , Lúpus Eritematoso Sistêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Trombose/diagnóstico por imagem , Trombose/prevenção & controle
3.
Lupus ; 25(12): 1288-98, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26964561

RESUMO

OBJECTIVE: The objective of this paper is to elucidate the not yet known plasma molecule candidates involved in the induction of tissue factor (TF) expression mediated by ß2GPI-dependent anticardiolipin antibody (aCL/ß2GPI) on monocytes. METHODS: Human serum incubated with FLAG-ß2GPI was applied for affinity chromatography with anti- FLAG antibody. Immunopurified proteins were analyzed by a liquid chromatography coupled with mass spectrometry (LC-MS). TF mRNA induced by the identified molecules on monocytes was also analyzed. RESULTS: Apolipoprotein B100 (APOB) was the only identified serum molecule in the MS search. Oxidized LDL, containing APOB as well as ox-Lig1 (a known ligand of ß2GPI), was revealed as a ß2GPI-binding molecule in the immunoprecipitation assay. TF mRNA was markedly induced by oxidized LDL/ß2GPI complexes with either WBCAL-1 (monoclonal aCL/ß2GPI) or purified IgG from APS patients. The activities of lipoprotein-associated phospholipase A2, one of the component molecules of oxidized LDL, were significantly higher in serum from APS patients than in those from controls. CONCLUSION: APOB (or oxidized LDL) was detected as a major ß2GPI binding serum molecule by LC-MS search. Oxidized LDL/aCL/ß2GPI complexes significantly induced TF expressions on monocytes. These data suggest that complexes of oxidized LDL and aCL/ß2GPI may have a crucial role in the pathophysiology of APS.


Assuntos
Anticorpos Anticardiolipina/metabolismo , Síndrome Antifosfolipídica/sangue , Apolipoproteína B-100/sangue , Lipoproteínas LDL/sangue , Tromboplastina/biossíntese , beta 2-Glicoproteína I/imunologia , Animais , Células HEK293 , Humanos , Camundongos , Células RAW 264.7
4.
Lupus ; 23(11): 1124-32, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24860121

RESUMO

The objective of this study was to clarify the long-term outcome in patients with lupus nephritis (LN) according to the International Society of Nephrology and Renal Pathology Society classification. This retrospective analysis comprised 186 Japanese patients given a diagnosis of LN by renal specimen with a mean observation period of 12 years. Primary end point was defined as death or end-stage renal disease, and standardized mortality ratios were calculated. Five patients presented with histopathological class I, 62 with II, 21 with III or III+V, 73 with IV or IV+V and 25 with V. Fourteen deaths occurred, corresponding to an overall standardized mortality ratio of 3.59 (95% confidence interval 2.02-5.81, p < 0.0001). Kaplan-Meier analysis revealed a 10-year overall survival of 95.7%. Nephrotic proteinuria (≥3.5 g/day) at baseline was identified as an independent poor prognostic factor for overall survival in Cox regression analysis. Kaplan-Meier analysis revealed a 10-year renal survival as 94.3%. Male gender and nephrotic proteinuria at baseline were identified as independent poor prognostic factors for renal survival in Cox regression analysis. In conclusion, LN was associated with a 3.59-fold increase in mortality compared with the general population. Male gender and nephrotic proteinuria were predictive for poor renal outcome.


Assuntos
Falência Renal Crônica/epidemiologia , Nefrite Lúpica/fisiopatologia , Proteinúria/epidemiologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Japão , Estimativa de Kaplan-Meier , Falência Renal Crônica/etiologia , Nefrite Lúpica/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Proteinúria/etiologia , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
6.
Lupus ; 22(8): 761-71, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23817509

RESUMO

BACKGROUND: CD36, known as a scavenger receptor, is a transmembrane glycoprotein expressed on monocytes, platelets and endothelial cells, recognizes multiple ligands, including phosphatidylserine, and regulates atherogenesis and thrombosis. The objective of this study is to investigate the possible involvement of CD36 in the pathophysiology of thrombosis in patients with antiphospholipid syndrome (APS). METHODS: First, rs3765187, a missense mutation linked to CD36 deficiency, was investigated by TaqMan polymerase chain reaction (PCR) genotyping method in 819 Japanese, including 132 patients with APS, 265 with systemic lupus erythematosus (SLE) in the absence of APS, and 422 healthy subjects. Then, the involvement of CD36 in antiphospholipid antibody (aPL)-induced tissue factor (TF) expression was examined using CD36-null mice or anti-CD36. Purified IgG from patients with APS and a monoclonal phosphatidylserine-dependent antiprothrombin antibody were used in these experiments. TF expression was tested by real-time PCR and flow cytometry. RESULTS: Minor allele carrier of rs3765187 was less frequent in patients with APS (3.8% p=0.032), but not in patients with SLE in the absence of APS (7.9% p=0.32), compared with healthy subjects (10.2%). The aPL-induced TF expression was significantly suppressed on peritoneal macrophages from CD36-null mice compared to wild type and significantly inhibited by anti-CD36 on human monocytes. CONCLUSIONS: The gene mutation linked to CD36 deficiency was less frequent in patients with APS. The deficient or suppressed CD36 function significantly reduced aPL-induced TF expression in vitro. Taken together, in a susceptible background CD36 scavenger receptor function may be involved in the thrombotic pathophysiology in patients with APS.


Assuntos
Anticorpos Antifosfolipídeos/metabolismo , Síndrome Antifosfolipídica/fisiopatologia , Antígenos CD36/genética , Trombose/fisiopatologia , Adolescente , Adulto , Idoso , Animais , Síndrome Antifosfolipídica/genética , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Genótipo , Humanos , Japão , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/fisiopatologia , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Monócitos/metabolismo , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real , Tromboplastina/genética , Adulto Jovem
8.
Lupus ; 21(14): 1506-14, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22936124

RESUMO

OBJECTIVE: To study the clinical and immunological manifestations of antiphospholipid syndrome (APS) in the Japanese population by a single-centre registration. METHODS: In this retrospective cohort study, 141 consecutive patients with APS, fulfilling the Sydney revised Sapporo criteria for definite APS, who visited our autoimmune clinic from 1988 to 2010, were recruited and followed up. All the patients were interviewed and underwent a general physical examination by qualified rheumatologists on the day of blood sampling. RESULTS: The population comprised 119 woman and 22 men with a mean age at diagnosis of 44 years (range 9-79 years). Seventy patients (49.6%) had primary APS, and 71 (50.4%) had systemic lupus erythematosus. The prevalence of thrombosis was 85.8 per cent, arterial thrombosis was found in 93 patients (66.0%) and venous thrombosis was found in 46 patients (32.6%). The most common thrombosis was cerebral infarction [86/141 (61.0%)] followed by deep vein thrombosis [33/141 (23.4%)]. Among 70 pregnant women, 45 (64.3%) had obstetric complications. Lupus anticoagulant was detected in 116 patients (82.3%), anticardiolipin antibodies in 83 (58.9%), anti-ß2 glycoprotein I antibodies in 73 (51.8%) and phosphatidylserine-dependent antiprothrombin antibodies in 98 (69.5%). CONCLUSION: High prevalence of arterial thrombosis was noted in Japanese patients with APS. The profile of heterogeneous and complex clinical manifestations was substantiated in Japanese patients with APS.


Assuntos
Anticorpos Antifosfolipídeos/imunologia , Síndrome Antifosfolipídica/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Trombose/epidemiologia , Adolescente , Adulto , Idoso , Síndrome Antifosfolipídica/complicações , Criança , Estudos de Coortes , Feminino , Seguimentos , Humanos , Japão , Lúpus Eritematoso Sistêmico/complicações , Masculino , Pessoa de Meia-Idade , Gravidez , Complicações na Gravidez/imunologia , Prevalência , Estudos Retrospectivos , Trombose/etiologia , Trombose/patologia , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Trombose Venosa/patologia , Adulto Jovem
9.
Lupus ; 20(10): 1047-56, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21676917

RESUMO

Pulmonary arterial hypertension (PAH) is a life-threatening complication in connective tissue diseases (CTD). It remains controversial whether immunosuppressive therapy is useful for PAH associated with CTD (PAH-CTD). The Dana Point algorithm does not refer such treatments in patients with PAH-CTD due to the lack of evidence. However, some case reports have shown the potential efficacy of immunosuppression for PAH-CTD. Here we report five cases of PAH-CTD treated with corticosteroids and discuss the current management of PAH-CTD with immunosuppressive agents. Our cases consisted of three active systemic lupus erythematosus (SLE), a quiescent SLE and an active polymyositis. WHO functional classes at baseline were class III in three cases and class II in two. Median follow-up period was 44 (28-92) weeks. PAH was diagnosed by right heart catheterization in all cases (median pulmonary arterial pressure was 45 (29-49) mmHg). All patients received 1 mg/kg of prednisolone (PSL) for 2-4 weeks, followed by appropriate dose reduction. Methylprednisolone pulse therapy was performed in patients resistant to the high dosage of PSL. Four patients received vasodilators in combination. The therapy as above improved WHO functional class 4 weeks after the initiation of PSL in all the patients. Two patients required dose increase or additional administration of vasodilators due to the dose reduction of PSL. Corticosteroid therapy may be effective for PAH-CTD at least in the short term, even in low general activity of CTD or moderate PAH. Our experience suggests that corticosteroid therapy, by itself or in conjunction with standard vasodilators, is effective for PAH-CTD patients.


Assuntos
Corticosteroides/uso terapêutico , Doenças do Tecido Conjuntivo/complicações , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/etiologia , Corticosteroides/administração & dosagem , Adulto , Algoritmos , Doenças do Tecido Conjuntivo/tratamento farmacológico , Doenças do Tecido Conjuntivo/fisiopatologia , Medicina Baseada em Evidências , Feminino , Humanos , Hipertensão Pulmonar/fisiopatologia , Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Masculino , Prednisolona/administração & dosagem , Prednisolona/uso terapêutico , Vasodilatadores/administração & dosagem
11.
Ann Rheum Dis ; 68(6): 1030-5, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18625630

RESUMO

OBJECTIVE: To investigate the significance of complement activation in patients with primary antiphospholipid syndrome (APS). METHODS: Thirty-six patients with primary APS, 42 control patients with non-systemic lupus erythematosus (SLE) connective tissue diseases, and 36 healthy volunteers were analysed retrospectively. Serum complement levels (C3, C4, CH(50)) and anaphylatoxins (C3a, C4a, C5a) were examined in all subjects, and serum complement regulatory factors (factor H and factor I) were measured in patients with primary APS. Plasma anticoagulant activity was determined in a mixing test using the activated partial thromboplastin time. RESULTS: Serum complement levels were significantly lower in patients with primary APS than in patients with non-SLE connective tissue diseases (mean (SD) C3: 81.07 (17.86) vs 109.80 (22.76) mg/dl, p<0.001; C4: 13.04 (8.49) vs 21.70 (6.96) mg/dl, p<0.001; CH(50): 31.32 (8.76) vs 41.40 (7.70) U/ml, p<0.001) or healthy volunteers. Only two healthy subjects with low serum C4 levels showed hypocomplementaemia, whereas most patients with primary APS showed raised serum C3a and C4a. No subjects showed raised C5a. Patients with primary APS with low serum C3 or C4 had significantly higher levels of C3a or C4a than healthy controls. No patients had low serum complement regulatory factors. Among patients with primary APS, hypocomplementaemia was significantly more common in those with high anticoagulant activity than in those with low or normal activity. CONCLUSION: Hypocomplementaemia is common in patients with primary APS, reflecting complement activation and consumption, and was correlated with anticoagulant activity, suggesting that antiphospholipid antibodies may activate monocytes and macrophages via anaphylatoxins produced in complement activation.


Assuntos
Síndrome Antifosfolipídica/imunologia , Ativação do Complemento/imunologia , Adolescente , Adulto , Idoso , Complexo Antígeno-Anticorpo/análise , Síndrome Antifosfolipídica/sangue , Coagulação Sanguínea , Estudos de Casos e Controles , Complemento C3/análise , Complemento C3a/análise , Complemento C4/análise , Complemento C4a/análise , Doenças do Tecido Conjuntivo/imunologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
12.
Rheumatology (Oxford) ; 47(11): 1686-91, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18782855

RESUMO

OBJECTIVES: Haemophagocytic syndrome (HPS) is known as a relatively rare complication in autoimmune diseases. Here we analysed the clinical features of HPS in patients with systemic autoimmune diseases. METHODS: One thousand and fourteen patients with systemic autoimmune diseases admitted to Hokkaido University Hospital from 1997 to 2007 were recruited [350 SLE, 136 RA, 98 polymyositis/dermatomyositis (PM/DM), 88 SSc, 91 vasculitis syndrome, 37 primary SS, 26 adult onset Still's disease (AOSD) and 188 other diseases]. Clinical features and treatment outcomes were retrospectively analysed. RESULTS: Thirty cases (3.0%) fulfilled HPS criteria (progressive cytopenia in two or more lineages and haemophagocytosis in reticuloendothelial systems). Underlying diseases were SLE (18), RA (2), PM/DM (2), SSc (2), vasculitis (1), SS (2) and AOSD (3). Nineteen patients were diagnosed as having autoimmune-associated HPS, eight infection-associated, one drug-induced and one developed HPS after haematopoietic stem cell transplantation. For the treatment of HPS, high-dose corticosteroid monotherapy was given in 26 cases, being effective in 12 (46%). Ten out of 15 patients with corticosteroid-resistant autoimmune-associated HPS were treated with CsA, cyclophosphamide or tacrolimus, leading to the remission in 80%. The overall mortality rate was 20%. Multivariate analysis showed that the presence of infections and CRP level >50 mg/l on HPS related with poor prognosis. CONCLUSIONS: The prevalence of HPS among in-hospital patients with systemic autoimmunity is not ignorable. Administration of immunosuppressants was effective in cases with autoimmune-associated HPS, whereas prognosis was poor in infection-associated HPS.


Assuntos
Doenças Autoimunes/complicações , Linfo-Histiocitose Hemofagocítica/complicações , Adulto , Idoso , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/mortalidade , Infecções Bacterianas/complicações , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/mortalidade , Ciclofosfamida/uso terapêutico , Ciclosporina/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Linfo-Histiocitose Hemofagocítica/mortalidade , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Tacrolimo/uso terapêutico , Viroses/complicações , Viroses/tratamento farmacológico , Viroses/mortalidade , Adulto Jovem
13.
Clin Exp Rheumatol ; 26(1): 129-32, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18328160

RESUMO

Thrombotic microangiopathy (TMA) is a rare disorder characterized by microvascular thrombosis. TMA has been reported in patients with antiphospholipid antibodies and/or antiphospholipid syndrome but its pathogenesis is not clarified. We present two patients with TMA associated with IgG phosphatidylserine dependent antiprothrombin antibodies (aPS/PT). CASE 1: A 44-year-old Japanese female with systemic lupus erythematosus (SLE) and positive lupus anticoagulant (LA) was started on ticlopidine after having stroke. Four weeks later she developed TMA. IgG/M/A anticardiolipin antibodies (aCL) were negative, but strong positive IgG aPS/PT were detected. CASE 2: A 32-year-old Russian female with SLE was admitted because of hypertension, renal insufficiency and proteinuria at 14 weeks of pregnancy. She developed TMA after surgical abortion. IgG aPS/PT and LA were strongly positive but IgG/M/A aCL were negative. Neither case had von Willebrand factor cleaving protease (ADAMTS-13), suggesting that TMA in those patients was associated with thrombophilia rather than insufficient ADAMTS-13. Both patients were successfully treated with a series of plasma exchange.


Assuntos
Síndrome Antifosfolipídica/complicações , Autoanticorpos/sangue , Fosfatidilserinas/fisiologia , Trombose/complicações , Doenças Vasculares/complicações , Adulto , Síndrome Antifosfolipídica/imunologia , Síndrome Antifosfolipídica/terapia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/complicações , Troca Plasmática , Gravidez , Complicações na Gravidez , Trombose/imunologia , Trombose/terapia , Doenças Vasculares/imunologia , Doenças Vasculares/terapia
14.
Atherosclerosis ; 152(2): 337-46, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10998461

RESUMO

beta(2)-glycoprotein I (beta(2)-GPI=apolipoprotein H) is an important autoantigen in patients with the antiphospholipid syndrome. It also plays a role in lipoprotein metabolism, such as anti-atherogenic property, triglyceride removal, and enhancement of lipoprotein lipase. Serum beta(2)-GPI concentration of 812 apparently healthy Japanese individuals was measured by sandwich EIA. Two families with complete beta(2)-GPI deficiency were identified. In one family, all affected had increased serum LDL-cholesterol levels or smaller particle sizes of LDL, while the other had no apparent abnormality in lipid metabolism. Individuals investigated had no history of thrombosis or overt abnormalities in hemostatic tests. A thymine corresponding to position 379 of the beta(2)-GPI cDNA was deleted in every beta(2)-GPI deficient individual. The incidence of this heterozygous deficiency determined by RFLP was 6. 3% in Japanese and none in Caucasians. Heterozygotes had significantly lower concentrations of serum beta(2)-GPI than did those without the mutation, yet no significantly different lipid profiles, such as total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, apoA-I, apoB and Lp(a), were observed. A low concentration of beta(2)-GPI seemed not to be associated with apparent abnormality in lipoprotein metabolism.


Assuntos
Apolipoproteínas/deficiência , Glicoproteínas/deficiência , Hemostasia , Lipoproteínas/sangue , Adulto , Idoso , Apolipoproteínas/genética , Feminino , Glicoproteínas/sangue , Glicoproteínas/genética , Heterozigoto , Humanos , Técnicas Imunoenzimáticas , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , beta 2-Glicoproteína I
16.
Biochem Pharmacol ; 54(5): 613-7, 1997 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9337078

RESUMO

The effects of denbufylline, a xanthine derivative with selective inhibitory activity on the phosphodiesterase (PDE) 4 isoenzyme, on bone loss in Walker 256/S-bearing rats and on mineralized nodule formation and osteoclastlike cell formation in bone marrow culture systems were examined. Serial oral administrations of denbufylline inhibited the decrease in the bone mineral density of femurs from Walker 256/S-bearing rats, without influence on the healthy rats. Denbufylline restored the bone mass and the number of osteoclasts and osteoblasts per trabecular surface in the femur metaphysis. Among PDE inhibitors, only PDE4-selective inhibitors increased the number of mineralized nodules and decreased the number of osteoclastlike cells in the in vitro bone marrow culture systems, and dibutyryl cyclic AMP mimicked these effects in the in vitro systems. These results suggest that the PDE4 isoenzyme may play an important role in bone turnover through cyclic AMP and that its inhibitors are candidates for therapeutic drugs for the bone loss diseases.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases , Reabsorção Óssea/prevenção & controle , Carcinoma 256 de Walker/fisiopatologia , Osteoclastos/citologia , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases/metabolismo , Xantinas/farmacologia , 1-Metil-3-Isobutilxantina/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Reabsorção Óssea/etiologia , Reabsorção Óssea/patologia , Bucladesina/farmacologia , Calcificação Fisiológica/efeitos dos fármacos , Calcificação Fisiológica/fisiologia , Carcinoma 256 de Walker/complicações , Carcinoma 256 de Walker/patologia , Células Cultivadas , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Feminino , Camundongos , Milrinona , Osteoclastos/efeitos dos fármacos , Purinonas/farmacologia , Piridonas/farmacologia , Ratos , Ratos Wistar
18.
Med Sci Sports Exerc ; 23(9): 1068-72, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1943628

RESUMO

The purpose of the present study was to compare the body configurations and the joint function during standing long jump in 6-yr-old children and adult males. Twelve healthy adult males and eight (one male and seven females) 6-yr-old kindergartners participated in this study. Subjects performed standing long jump on a force platform with full effort. Body segment and joint angles were analyzed by high speed videography (100 frames.s-1). Using kinetic and kinematic data, joint moments, power, and work done were calculated through a free body diagram. Average standing long jump performances were +1.5 SD above Japanese norm in both adults and children. A wide range of motion of the lower limb segments during flight phase was found in the adults. In the crouch prior to take off, joint muscle power peaks appeared in the same order, and joint contribution to the total work done showed almost the same values in both adults and children. It is suggested that gross motor pattern before take off is almost accomplished by the 6-yr-old. Judging by hip joint work, adult performance was much better than that of children, since the adults exerted relatively higher negative work from the onset of preparatory movement to the point of lowest center of gravity during crouch. It was concluded that skilled 6-yr-old children have not fully developed either hip negative work during preparatory movement or body configuration in the flight phase, although gross motor pattern before take off phase was accomplished to skilled adult level.


Assuntos
Articulações/fisiologia , Movimento/fisiologia , Postura , Esportes , Adulto , Fenômenos Biomecânicos , Criança , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Músculos/fisiologia , Amplitude de Movimento Articular/fisiologia
19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 64(3 Pt 1): 031908, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11580368

RESUMO

The array-enhanced stochastic resonance (AESR) in the diffusively coupled FitzHugh-Nagumo equation is investigated. The two properties of AESR, namely, the scaling of the optimal noise intensity and the enhancement of the maximum value of the correlation coefficient as a function of the coupling strength, are analyzed theoretically. By transforming the dynamics of N elements into that of the mean and the deviation from it, it is found that AESR is caused by the correlation between them. A low-dimensional model that reproduces the above properties is constructed.


Assuntos
Rede Nervosa , Neurônios/fisiologia , Animais , Encéfalo/patologia , Humanos , Modelos Neurológicos , Modelos Estatísticos , Modelos Teóricos , Análise Multivariada , Processos Estocásticos
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