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1.
J Electr Bioimpedance ; 11(1): 19-25, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33584899

RESUMO

There is a strong need for a non-invasive measurement technique that is capable of accurately identifying the physiological condition change or heterogeneity of subcutaneous adipose tissue (SAT) by localizing the abnormalities within the compartment. This paper aims to investigate the feasibility of Electrical Impedance Tomography (EIT) to assess the interstitial fluid in subcutaneous adipose tissue as an enhancement method of bioelectrical impedance spectroscopy (BIS). Here, we demonstrate the preliminary result of EIT with a wearable 16 electrodes sensor. The image-based reference EIT with fat weighted threshold method is proposed. In order to evaluate the performance of our novel method, a physiological swelling experiment is conducted, and Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is also applied as a comparison with EIT results. The experimental results showed that the proposed method was able to distinguish the physiological swelling condition and effectively to remove the unexpected background noise. Furthermore, the conductivity variation in the subcutaneous layer had a good correlation with extracellular water volume change from MFBIA data; the correlation coefficient R2 = 0.927. It is concluded that the proposed method provides a significant prospect for SAT assessment.

2.
Nanotechnology ; 28(16): 165302, 2017 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-28273045

RESUMO

We have formed tunnel barriers in individual multi-wall carbon nanotubes using the Ga focused ion beam irradiation. The barrier height was estimated by the temperature dependence of the current (Arrhenius plot) and the current-voltage curves (Fowler-Nordheim plot). It is shown that the barrier height has a strong correlation with the barrier resistance that is controlled by the dose. Possible origins for the variation in observed barrier characteristics are discussed. Finally, the single electron transistor with two barriers is demonstrated.

3.
Chem Commun (Camb) ; 53(17): 2630-2633, 2017 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-28195292

RESUMO

We report the synthesis and characterisation of palladium complexes bearing an N-heterocyclic carbene-phosphine oxide bidentate ligand and their use as catalysts for ethylene polymerisation and ethylene/polar monomer copolymerisation.

4.
Eur J Surg Oncol ; 42(4): 481-8, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26852107

RESUMO

BACKGROUND: The critical issue related to breast-conserving therapy (BCT) is that cosmetic outcomes deteriorate with long-term follow-up. There is little research for breast density as a predictor of cosmetic outcomes at the late stage after BCT. To improve the long-term quality of life after BCT of breast cancer patients, the correlation of volumetric breast density (VBD) and cosmetic outcome at the late stage after BCT was evaluated. STUDY DESIGN: Breast volume, fibroglandular tissue volume, adipose tissue volume, and VBD were calculated on mammography using image analysis software (Volpara(®)) in 151 patients with BCT. Furthermore, the correlation of breast density and the change of breast volume over time was analyzed on mammography in 99 patients who were followed-up long-term after BCT. RESULTS: On multivariate analysis, VBD was a predictor of cosmetic outcome after BCT with percent breast volume excised (PBVE). Decreased adipose tissue volume and increased fibrosis were more common in patients with VBD < 15%. Furthermore, remnant breast volume continued to decrease over time in low breast density patients during long-term follow-up. 93% of patients with VBD ≥ 15% and PBVE < 10% had a better cosmetic outcome, while 60% of patients with VBD < 15% and PBVE ≥ 10% had a worse cosmetic outcome after BCT. CONCLUSIONS: While PBVE was involved in cosmetic outcome at the early stage after BCT, VBD was associated with cosmetic outcome at the late stage after BCT. Thus, a combination of VBD and PBVE could predict cosmetic outcome after BCT and contribute to the selection for the appropriate BCT.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia Segmentar/métodos , Qualidade de Vida , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/psicologia , Feminino , Seguimentos , Humanos , Mamografia , Mastectomia Segmentar/psicologia , Pessoa de Meia-Idade , Tamanho do Órgão , Período Pós-Operatório , Prognóstico , Curva ROC , Estudos Retrospectivos , Fatores de Tempo
5.
Leukemia ; 29(11): 2274, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26531889

RESUMO

Correction to: Leukemia (2000); 14: 1260­1265; doi: 10.1038/sj.leu.2401828. Since the publication of the above article the authors have identified an error in Figure 1. Figure 1 shows the modulation of telomerase activity by herbimycin A in K562 cells: (a) cell cycle and (b) telomerase activity, mRNA expressions of hTERT, hTERC, TEP-1, c-myc, cyclin D1 and b-actin, and c-Myc protein. The authors however wish to inform the readers that Figure 1b incorrectly shows hTERT mRNA, which is the result of herbimycin A treatment of cyclin-D1-transfected K562 cells (Figure 3b, hTERT mRNA). While preparing Figure 1, the authors mistakenly submitted a figure that used the incorrect photo data following confusion regarding file names. The correct figure can be found below: The authors wish to apologise for any inconvenience caused and confirm that the conclusions drawn from this research are not affected by this error.

6.
Radiat Prot Dosimetry ; 151(4): 656-60, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22914335

RESUMO

Effective therapy for chronic radiation injuries, such as ulcers, is prone to infection. Stiffness is expected since the therapeutic radiation often involves wider and deeper tissues and often requires extensive debridement and reconstruction, which are not sometimes appropriate for elderly and compromised hosts. Autologous adipose-derived regenerative cells (ADRCs) are highly yielding, forming relatively elderly aged consecutive 10 cases, 63.6±14.9 y (52-89 y), with mean radiation dose of 75.0±35.4 Gy (50-120 Gy) were included with at least 10-month follow-up. Minimal debridement and ADRC injection in the wound bed and margin along with the injection of mixture of fat and ADRCs in the periphery were tested for efficacy and regenerated tissue quality by clinically as well as imaging by computed tomography and magnetic resonance imaging. Uncultured ADRCs of 1.6±1.3×10(7) cells were obtained. All cases healed uneventfully after 6.6±3.2 weeks (2-10 weeks) post-operatively. The done site morbidity was negligible and without major complications, such as paralysis or massive haematoma. The regenerated tissue quality was significantly superior to the pre-operative one and the mixture of fat and ADRCs connected to the intact tissue was very soft and pliable. Mean follow-up at 1.9±0.8 y (0.9-2.9 y) revealed no recurrence or new ulceration after treatment. Thus, the ADRCs treatment for decades-long radiation injuries is effective, safe and improves the quality of wounds.


Assuntos
Tecido Adiposo , Lesões por Radiação , Humanos
7.
Transfus Med ; 20(2): 95-103, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19883399

RESUMO

To evaluate the specific reactivity of HLA Class I antibodies (HLA-I Abs) in acute non-hemolytic transfusion reactions (ANHTRs) using solid phase assays (SPAs) and conventional complement-dependent lymphocyte cytotoxicity test (LCT). ANHTRs are major issues in transfusion medicine. Anti-leukocyte antibodies have been implicated as one of the causative agents of transfusion-related acute lung injury (TRALI) and febrile reaction. Antibodies to HLA Class I and/or Class II (HLA Abs) have been intensively studied using SPAs for TRALI, but not for febrile reaction. About 107 patients and 186 donors associated with ANHTRs were screened for HLA Abs by SPAs such as enzyme-linked immunosorbent assay (ELISA) and the Luminex method. When HLA-I Ab was detected, its specific reactivity was evaluated by comparing its specificity identified by the Luminex method using recombinant HLA molecules and cognate HLA antigens (Ags), as well as LCT with or without anti-human globulin (AHG). The incidences of HLA Abs were as high as 32.7% of patients' serum samples and 16% of donors' serum samples. The incidence of HLA-I Abs did not differ significantly between cases of febrile and allergic reactions. However, HLA-I Abs associated with febrile reaction showed a significantly higher rate of possessing specific reactivity to cognate HLA Ags than those associated with allergic reactions. In addition, the Luminex method enabled the detection of HLA-I Abs much earlier than AHG-LCT in serum samples from a patient with febrile reaction and platelet transfusion refractoriness (PTR). SPAs seem more useful than AHG-LCT for evaluating reactivity of antibodies in ANHTR cases.


Assuntos
Lesão Pulmonar Aguda/etiologia , Anafilaxia/etiologia , Febre/etiologia , Antígenos HLA/imunologia , Teste de Histocompatibilidade/métodos , Isoanticorpos/sangue , Reação Transfusional , Urticária/etiologia , Doença Aguda , Lesão Pulmonar Aguda/imunologia , Adulto , Idoso , Anafilaxia/imunologia , Especificidade de Anticorpos , Reações Antígeno-Anticorpo , Criança , Testes Imunológicos de Citotoxicidade , Ensaio de Imunoadsorção Enzimática , Feminino , Febre/imunologia , Fluorometria , Seguimentos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Neoplasias/terapia , Urticária/imunologia
8.
J Bone Joint Surg Br ; 88(5): 637-41, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16645111

RESUMO

A total of 11 patients with combined traumatic injuries of the brachial plexus and spinal cord were reviewed retrospectively. Brachial plexus paralysis in such dual injuries tends to be diagnosed and treated late and the prognosis is usually poor. The associated injuries, which were all on the same side as the plexus lesion, were to the head (nine cases), shoulder girdle (five), thorax (nine) and upper limb (seven). These other injuries were responsible for the delayed diagnosis of brachial plexus paralysis and the poor prognosis was probably because of the delay in starting treatment and the severity of the associated injuries. When such injuries are detected in patients with spinal cord trauma, it is important to consider the possibility of involvement of the brachial plexus.


Assuntos
Plexo Braquial/lesões , Traumatismo Múltiplo/cirurgia , Traumatismos da Medula Espinal/cirurgia , Acidentes , Adulto , Idoso , Plexo Braquial/diagnóstico por imagem , Plexo Braquial/cirurgia , Plexo Cervical/diagnóstico por imagem , Plexo Cervical/lesões , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/lesões , Humanos , Masculino , Traumatismo Múltiplo/diagnóstico por imagem , Paralisia/etiologia , Paralisia/cirurgia , Radiografia , Estudos Retrospectivos , Traumatismos da Medula Espinal/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/lesões , Resultado do Tratamento
9.
Br J Dermatol ; 153(1): 29-36, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16029323

RESUMO

BACKGROUND: Large or deteriorated skin defects are sometimes life threatening. There is increasing evidence that adult stem cells are useful for tissue regeneration. Human mesenchymal stem cells (hMSCs) are self-renewing and are potent in differentiating into multiple cells and tissues. OBJECTIVES: To investigate the effects of hMSCs in cutaneous wound healing. METHODS: Wound healing was studied in an hMSC-populated porcine skin substitute, using a nude rat model to minimize immune reactions. Full-thickness skin and soft tissue defects of 1.5 x 1.5 cm in size, including the panniculus carnosus, were excised and covered with hMSCs and basic fibroblast growth factor (bFGF)-soaked skin substitutes and an evaluation was made of wound size, histology and protein expression at 3, 7 and 42 days after injury. RESULTS: The wound size was significantly smaller in the hMSC-treated groups (P < 0.01) and any dose of bFGF (1, 10, 100 microg) enhanced the healing (P < 0.01). The re-epithelialization markers integrin alpha3 and skin-derived antileucoproteinase were remarkably increased with the presence of bFGF in a dose-dependent manner, while the mesenchymal cell surface markers CD29 and CD44 were downregulated in a time-dependent manner. Human pancytokeratin, which does not cross-react with rat antigens, was observed by Western blotting at 38 kDa and 42 kDa from the hMSC-treated tissues on day 7. The expression levels were elevated by 10 microg bFGF (P < 0.01). The immunohistochemical expression of human pancytokeratin was only observed in the hMSC-treated groups. CONCLUSIONS: These data suggest that hMSCs together with bFGF in a skin defect model accelerate cutaneous wound healing as the hMSCs transdifferentiate into the epithelium.


Assuntos
Transplante de Células-Tronco Mesenquimais , Pele Artificial , Pele/lesões , Cicatrização , Animais , Western Blotting/métodos , Procedimentos Cirúrgicos Dermatológicos , Relação Dose-Resposta a Droga , Fator 2 de Crescimento de Fibroblastos/uso terapêutico , Humanos , Receptores de Hialuronatos/metabolismo , Integrina alfa3/metabolismo , Integrina beta1/metabolismo , Masculino , Proteínas Secretadas Inibidoras de Proteinases , Proteínas/metabolismo , Ratos , Ratos Endogâmicos F344 , Ratos Nus , Pele/patologia , Suínos , Cicatrização/efeitos dos fármacos
10.
Chemosphere ; 59(8): 1105-11, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15833484

RESUMO

Study has been performed on the investigation of metal leaching behavior for fly and bottom ashes from automobile tire wastes using acid and alkaline solutions from both viewpoints of environmental protection and resource utilization. The two ashes were found to contain substantial amounts of zinc and iron along with small quantities of cobalt, manganese, magnesium, copper, titanium and aluminum. The fly ash contained a much larger amount of zinc than the bottom ash, and seems to be a promising secondary source for the metal. Effects of such experimental parameters as temperature, time and solid-liquid ratio on the leaching behavior were investigated. Using three mineral acids and citric acid, selective leaching of zinc was successfully attained; the concentration of zinc in the leach liquors from the fly ash reached as high as 20 g l(-1) while the iron leaching was much suppressed. Selective separation of zinc was also attained in the leaching with alkaline solutions, though the percent leaching was lower than that in the acid leaching. Moreover, solvent extraction and precipitation were applied to the metal-loaded leach liquors as downstream processing to evaluate the feasibility of zinc recovery.


Assuntos
Carbono , Incineração , Eliminação de Resíduos , Zinco/análise , Zinco/isolamento & purificação , Ácidos/química , Automóveis , Ácido Cítrico/química , Cinza de Carvão , Material Particulado , Difração de Raios X
11.
Eur J Echocardiogr ; 3(1): 52-8, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12067535

RESUMO

AIMS: To evaluate the effect of considerably high left ventricular filling pressure with mitral regurgitation on mitral annular velocity during early diastole. SUBJECTS: Two hundred and forty-three patients who underwent cardiac catheterization for evaluation of chest pain. METHODS: Mitral annular velocity during early diastole was measured by colour M-mode tissue Doppler imaging. Patients were divided into the following three groups according to the cardiac catheterization data. Group A (n=147): patients having left ventricular relaxation time constant tau<46 ms and left ventricular end-systolic volume index <38 ml m(-2); group B (n=88): patients having tau>or=46 ms and/or end-systolic volume index >or=38 ml m(-2); group C (n=8): patients having mean pulmonary capillary wedge pressure >or=16 mmHg in addition to tau>or=46 ms and end-systolic volume index >or=38 ml m(-2). RESULTS: Mitral annular velocity during early diastole was significantly less in group B (4.8+/-1.4 cm s(-1)) than in group A (7.7+/-1.9 cm s(-1)). However, there was no significant difference between groups A and C (8.3+/-0.8 cm s(-1)). A transmitral E/A >1.0 was observed in 12/147 patients of group A, 10/88 of group B, and 8/8 of group C. The incidence of >or=Sellers' grade II mitral regurgitation was higher in group C than the others. CONCLUSIONS: A paradoxically faster mitral annular velocity during early diastole is found in patients having left ventricular dysfunction with moderate to severe mitral regurgitation and considerably high left ventricular filling pressure. Attention should be paid to an interpretation of mitral annular velocity during early diastole regarding left ventricular early diastolic performance in patients having mitral regurgitation with an E/A >1.0 in their transmitral flow.


Assuntos
Velocidade do Fluxo Sanguíneo , Ecocardiografia , Insuficiência da Valva Mitral/fisiopatologia , Valva Mitral/diagnóstico por imagem , Função Ventricular Esquerda , Pressão Ventricular , Cateterismo Cardíaco , Diástole , Ecocardiografia Doppler em Cores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/diagnóstico por imagem , Pressão Propulsora Pulmonar , Volume Sistólico
12.
J Chromatogr A ; 932(1-2): 159-63, 2001 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-11695862

RESUMO

A new surfactant-mediated separation method was developed for concentrating traces of gold ion in water. The methodology is based on the combination of selective complexation of gold(III) with polyoxyethylene(10)-p-isononylphenyl ether, PONPE-10, and strong binding of surfactant complex to hydrophobic polystyrene resins embedded in a PTFE fiber disk (Empore disk). A 400-fold concentration of gold(III) was achieved by 400 ml load of the sample containing 0.01% (w/v) PONPE-10 and 0.10 M nitric acid and by the subsequent elution with 1.0 ml of aqueous buffer solution of 0.01 M N-(dithiocarboxyl)sarcosine diammonium. Traces of gold (0.40 ng/l) in river water samples were successfully determined with inductively coupled plasma MS.


Assuntos
Éteres/química , Ouro/química , Polietilenoglicóis/química , Poliestirenos/química , Água/química , Espectrometria de Massas
13.
J Am Soc Echocardiogr ; 14(11): 1070-4, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11696830

RESUMO

Propagation velocity of left ventricular (LV) early diastolic filling flow (PVE) has been acknowledged as a useful parameter for LV early diastolic performance; however, the effect of LV systolic performance on PVE is not fully understood. Thus the purpose of this study was to investigate such an effect. Propagation of LV early diastolic filling flow was visualized by M-mode color Doppler imaging, and the slopes of the peak velocity tracings were measured as PVE in 150 patients who underwent coronary angiography. In cardiac catheterization, mean pulmonary capillary wedge pressure, time constant tau of LV pressure decay, LV end-systolic volume index, and LV ejection fraction were obtained. In univariate regression analysis, PVE significantly correlated with LV end-systolic volume index (r = -0.68, P <.001), LV ejection fraction (r = 0.66, P <.001), and time constant tau (r = -0.52, P <.001). In multivariate regression analysis, PVE was regressed by the LV end-systolic volume index, tau, and mean pulmonary capillary wedge pressure. The contribution of each parameter to the variance of the PVE was 46%, 3%, and 2%, respectively. A break-point linear regression analysis showed that the relation between the LV end-systolic volume index and PVE was much better characterized by a broken line than a straight line. The broken line had a steeper slope in patients with LV end-systolic volume index < or =41 mL/m(2) than in those with >41 mL/m(2). These findings suggest that PVE is determined mainly by LV systolic performance and partly by both LV relaxation and LV filling pressure. Left ventricular systolic performance may play a key role in generating a much faster PVE, especially in patients with relatively better LV systolic performance.


Assuntos
Doença da Artéria Coronariana/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Idoso , Velocidade do Fluxo Sanguíneo , Cateterismo Cardíaco , Doença da Artéria Coronariana/diagnóstico por imagem , Diástole/fisiologia , Ecocardiografia Doppler em Cores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Análise de Regressão , Sístole/fisiologia , Pressão Ventricular
14.
Genes Genet Syst ; 76(2): 89-97, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11434463

RESUMO

We investigated the expressions of genes for alternative oxidase (AOX1a, AOX1b, AOX1c and AOX2) and genes for cytochrome c oxidase (COX5b and COX6b) during germination of Arabidopsis thaliana, and examined oxygen uptakes of the alternative respiration and the cytochrome respiration in imbibed Arabidopsis seeds. A Northern blot analysis showed that AOX2 mRNA has already accumulated in dry seeds and subsequently decreased, whereas accumulation ofAOX1a mRNA was less abundant from 0 hours to 48 hours after imbibition and then increased. The increase of the capacity of the alternative pathway appeared to be dependent on the expressions of both AOX2 and AOX1a. On the other hand, steady-state mRNA levels of COX5b and COX6b were gradually increased during germination, and the capacity of the cytochrome pathway was correlated with the increase of expressions of the COX genes. Antimycin A, the respiratory inhibitor, strongly increased the expression of AOX1a but had no effect on the expression of AOX2. A 5'RACE analysis showed that AOX2 consists of five exons, which is different from the case of most AOX genes identified so far. Analysis of subcellular localization of AOX2 using green fluorescent protein indicated that the AOX2 protein is imported into the mitochondria.


Assuntos
Arabidopsis/enzimologia , Arabidopsis/genética , Oxirredutases/genética , Sequência de Aminoácidos , Antimicina A/farmacologia , Northern Blotting , Clonagem Molecular , Éxons , Proteínas de Fluorescência Verde , Íntrons , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Proteínas Mitocondriais , Modelos Genéticos , Dados de Sequência Molecular , Oxigênio/metabolismo , Proteínas de Plantas , RNA Mensageiro/metabolismo , Fatores de Tempo
15.
Anticancer Res ; 21(1A): 167-71, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11299730

RESUMO

BACKGROUND: TNF-alpha is one of the key inflammatory cytokines and it modulates various events through several pathways. U937 myelomonocytic leukemia cells are sensitive to TNF-alpha and about 20% of these cells undergo apoptosis within 6 hours after treatment. Co-treatment of these cells with actinomycin D or cycloheximide enhances TNF-alpha induced apoptosis, suggesting that some TNF-alpha-derived signals can augment apoptosis. We investigated whether mitosis-activating protein kinases (MAPKs) had an influence on TNF-alpha induced apoptosis. MATERIALS AND METHODS: U937 cells were treated by TNF-alpha with or without MEK or p38MAPK inhibitors. Apoptosis was assessed morphologically by fluorescence microscopy and caspase-3 was studied by immunoblotting. Expression of apoptosis-inhibitory proteins was studied by RT-PCR whilst the activation of JNKs was investigated by detecting their phosphorylation. RESULTS: TNF-alpha treatment induced apoptosis in about 23% of the cells, while pretreatment with a MEK inhibitor (PD98059) caused 69% of the cells to undergo apoptosis. The inhibition of p38MAPK by SB203580 scarcely enhanced apoptosis, although another p38MAPK inhibitor (PD169316) induced apoptosis in 37% of the cells. Simultaneous pretreatment of cells with PD98059 and PD169316 resulted in the highest level of TNF-alpha induced apoptosis and 90% of the cells underwent apoptosis after 6 hours. In cells pretreated with PD98059 plus PD169316, caspase-3 was completely cleaved at 6 hours and early induction of c-IAP2/HIAP 1 mRNA was not observed. JNKs showed rapid and extensive phosphorylation in these cells. CONCLUSION: TNF-alpha induced apoptosis was potentiated by the inhibition of either MEK alone, or MEK plus p38MAPK, suggesting that the MAPK pathway may be a promising target for cancer therapy.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologia , Caspase 3 , Caspases/metabolismo , Sinergismo Farmacológico , Precursores Enzimáticos/metabolismo , Flavonoides/farmacologia , Humanos , Imidazóis/farmacologia , Proteínas Inibidoras de Apoptose , Proteínas Quinases JNK Ativadas por Mitógeno , MAP Quinase Quinase 1 , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas/metabolismo , Piridinas/farmacologia , Células U937 , Proteínas Quinases p38 Ativadas por Mitógeno
16.
J Biol Chem ; 276(27): 24690-6, 2001 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-11325965

RESUMO

In this report, we demonstrate an interaction between subtilisin NAT (formerly designated BSP, or nattokinase), a profibrinolytic serine proteinase from Bacillus subtilis, and plasminogen activator inhibitor 1 (PAI-1). Subtilisin NAT was purified to homogeneity (molecular mass, 27.7 kDa) from a saline extract of B. subtilis (natto). Subtilisin NAT appeared to cleave active recombinant prokaryotic PAI-1 (rpPAI-1) into low molecular weight fragments. Matrix-assisted laser desorption/ionization in combination with time-of-flight mass spectroscopy and peptide sequence analysis revealed that rpPAI-1 was cleaved at its reactive site (P1-P1': Arg(346)-Met(347)). rpPAI-1 lost its specific activity after subtilisin NAT treatment in a dose-dependent manner (0.02-1.0 nm; half-maximal effect at approximately 0.1 nm). Subtilisin NAT dose dependently (0.06-1 nm) enhanced tissue-type plasminogen activator-induced fibrin clot lysis both in the absence of rpPAI-1 (48 +/- 1.4% at 1 nm) and especially in the presence of rpPAI-1 (78 +/- 2.0% at 1 nm). The enhancement observed in the absence of PAI-1 seems to be induced through direct fibrin dissolution by subtilisin NAT. The stronger enhancement by subtilisin NAT of rpPAI-1-enriched fibrin clot lysis seems to involve the cleavage and inactivation of active rpPAI-1. This mechanism is suggested to be important for subtilisin NAT to potentiate fibrinolysis.


Assuntos
Inibidor 1 de Ativador de Plasminogênio/metabolismo , Subtilisinas/metabolismo , Bacillus subtilis/enzimologia , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Fibrina/metabolismo , Fibrinogênio/metabolismo , Fibrinólise/efeitos dos fármacos , Humanos , Peso Molecular , Mapeamento de Peptídeos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Subtilisinas/isolamento & purificação
17.
Eur J Gastroenterol Hepatol ; 13(2): 127-36, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11246611

RESUMO

BACKGROUND AND AIMS: E-cadherin, which is a [Ca2+]-dependent, homotypic cell-cell adhesion molecule, is expressed in gastrointestinal epithelial cells. Much has been learned about the down-regulation of E-cadherin expression in gastrointestinal tumours, Barrett's oesophageal dysplasia, and Crohn's disease, but the functions of this molecule in normal gastrointestinal mucosa are less known. METHODS: In this study, we investigated the relationship between E-cadherin expression and permeability using rat cultured gastric and intestinal epithelial cells following a 30-min exposure to various pH solutions. We also investigated the participation of [Ca2+] in these events. RESULTS: E-cadherin expression increased under acid (pH 4) but not alkali (pH 10 or 11) exposure only for gastric epithelial cells. Gastric epithelial permeability was maintained only against acid exposure while intestinal permeability increased under both conditions. Transient influx of [Ca2+] was only observed for gastric epithelial cells just after acid exposure. CONCLUSIONS: These findings suggest that E-cadherin expression on gastric epithelium stabilizes the epithelial barrier against acid, probably through influx of [Ca2+]. This event is thought to be one of the protective mechanisms in gastric mucosa against acid back-diffusion, which is one of the causes of peptic ulcer formation.


Assuntos
Caderinas/biossíntese , Cálcio/metabolismo , Mucosa Gástrica/metabolismo , Ácidos , Álcalis , Animais , Western Blotting , Caderinas/análise , Permeabilidade da Membrana Celular , Sobrevivência Celular , Células Cultivadas , Células Epiteliais , Mucosa Gástrica/citologia , Concentração de Íons de Hidrogênio , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
J Electron Microsc (Tokyo) ; 49(3): 415-21, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11108029

RESUMO

Among many scanning probe microscopies, atomic force microscopy (AFM) is a useful technique to analyse the structure of biological materials because of its applicability to non-conductors in physiological conditions with high resolution. However, the resolution has been limited to an inherent property of the technique; tip effect associated with a large radius of the scanning probe. To overcome this problem, we developed a carbon nanotube probe by attaching a carbon nanotube to a conventional scanning probe under a well-controlled process. Because of the constant and small radius of the tip (2.5-10 nm) and the high aspect ratio (1:100) of the carbon nanotube, the lateral resolution has been much improved judging from the apparent widths of DNA and nucleosomes. The carbon nanotube probes also possessed a higher durability than the conventional probes. We further evaluated the quality of carbon nanotube probes by three parameters to find out the best condition for AFM imaging: the angle to the tip axis; the length; and the tight fixation to the conventional tip. These carbon nanotube probes, with high vertical resolution, enabled us to clearly visualize the subunit organization of multi-subunit proteins and to propose structural models for proliferating cell nuclear antigen and replication factor C. This success in the application of carbon nanotube probes provides the current AFM technology with an additional power for the analyses of the detailed structure of biological materials and the relationship between the structure and function of proteins.


Assuntos
Proteínas de Ligação a DNA/ultraestrutura , Proteínas de Homeodomínio , Microscopia de Força Atômica/instrumentação , Nucleossomos/ultraestrutura , Antígeno Nuclear de Célula em Proliferação/ultraestrutura , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Carbono , Antígenos de Histocompatibilidade Menor , Modelos Moleculares , Proteína de Replicação C
19.
J Electron Microsc (Tokyo) ; 49(3): 453-8, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11108034

RESUMO

We describe the first cell biological application of carbon nanotube (CN) probes for atomic force microscopy studies. Topographic and phase images were collected from Plasmodium falciparum malaria-infected erythrocytes using both TappingMode Etched Silicon Probes (TESP probe) and CN probes. We estimate that the lateral resolution of a CN probe-generated topographic image is at least four-fold higher than that of the TESP probe. Carbon nanotube probe-generated phase images of P. falciparum-induced knobs on the surface of erythrocytes also show a markedly higher lateral resolution than comparable TESP probe-generate phase images of the same area. We conclude that CN probes are useful for cell biological atomic force microscopy studies and should play an increasingly important role in the future of this evolving discipline.


Assuntos
Eritrócitos/parasitologia , Eritrócitos/ultraestrutura , Microscopia de Força Atômica/instrumentação , Plasmodium falciparum , Animais , Membrana Eritrocítica/ultraestrutura
20.
Planta ; 211(4): 467-73, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11030545

RESUMO

Rice is the only cereal in which germination and coleoptile elongation occur in hypoxia or anoxia. Little is known of the molecular basis directly underlying coleoptile cell extension. In this paper, we describe the expression of alpha-expansin genes in embryos during seed development and young seedlings grown under various oxygen concentrations. The genes Os-EXP2 and Os-EXP1 were predominantly expressed in the developing seeds, mainly in newly developed leaves, coleoptiles, and seminal roots. These expansins expressed in the developing seeds may give cells the potential to expand after seed imbibition begins. In coleoptiles, Os-EXP4 and Os-EXP2 mRNAs were greatly induced by submergence, while they were weakly detected in aerobic or anoxic conditions. Under submerged soil conditions, the signals hybridized with probes Os-EXP4 and Os-EXP2 in coleoptiles were strongest when coleoptiles elongated in the water layer. These data show that expansin gene expression is highly correlated with coleoptile elongation in response to oxygen concentrations. The Os-EXP4 gene was also expressed in leaves, mesocotyls, and coleorhizas of young seedlings. The growth of these tissues was also correlated with the presence of expansins. Therefore, the evidence derived from this study clearly demonstrates that expansins are indispensable for the growing tissues of rice seedlings.


Assuntos
Oryza/genética , Proteínas de Plantas/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Oryza/crescimento & desenvolvimento
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