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1.
J Phys Chem A ; 128(7): 1241-1249, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38324399

RESUMO

The recent implementation of attosecond and few-femtosecond X-ray pump/X-ray probe schemes in large-scale free-electron laser facilities has opened the way to visualize fast nuclear dynamics in molecules with unprecedented temporal and spatial resolution. Here, we present the results of theoretical calculations showing how polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) can be used to visualize the dynamics of hydrogen migration in methanol, ethanol, propanol, and isopropyl alcohol dications generated by X-ray irradiation of the corresponding neutral species. We show that changes in the PA-MFPADs with the pump-probe delay as a result of intramolecular photoelectron diffraction carry information on the dynamics of hydrogen migration in real space. Although visualization of this dynamics is more straightforward in the smaller systems, methanol and ethanol, one can still recognize the signature of that motion in propanol and isopropyl alcohol and assign a tentative path to it. A possible pathway for a corresponding experiment requires an angularly resolved detection of photoelectrons in coincidence with molecular fragment ions used to define a molecular frame of reference. Such studies have become, in principle, possible since the first XFELs with sufficiently high repetition rates have emerged. To further support our findings, we provide experimental evidence of H migration in ethanol-OD from ion-ion coincidence measurements performed with synchrotron radiation.

3.
Gene Ther ; 24(11): 706-716, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28820502

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with a median survival of 3-4 years after diagnosis. It is the most frequent form of a group of interstitial pneumonias of unknown etiology. Current available therapies prevent deterioration of lung function but no therapy has shown to improve survival. Periostin is a matricellular protein of the fasciclin 1 family. There is increased deposition of periostin in lung fibrotic tissues. Here we evaluated whether small interfering RNA or antisense oligonucleotide against periostin inhibits lung fibrosis by direct administration into the lung by intranasal route. Pulmonary fibrosis was induced with bleomycin and RNA therapeutics was administered during both acute and chronic phases of the disease. The levels of periostin and transforming growth factor-ß1 in airway fluid and lung tissue, the deposition of collagen in lung tissue and the lung fibrosis score were significantly reduced in mice treated with siRNA and antisense against periostin compared to control mice. These findings suggest that direct administration of siRNA or antisense oligonucleotides against periostin into the lungs is a promising alternative therapeutic approach for the management of pulmonary fibrosis.


Assuntos
Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/fisiologia , Fibrose Pulmonar/terapia , Administração Intranasal/métodos , Animais , Bleomicina/farmacologia , Colágeno/análise , Feminino , Fibroblastos/metabolismo , Fibrose , Fibrose Pulmonar Idiopática/genética , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/terapia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Oligonucleotídeos , Oligonucleotídeos Antissenso/metabolismo , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/farmacologia , Fator de Crescimento Transformador beta/análise
4.
J Periodontal Res ; 51(5): 613-21, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26667496

RESUMO

BACKGROUND AND OBJECTIVE: Previous studies have shown that cigarette smoke (CS) and periodontal pathogens could alter wound healing responses of gingival epithelial cells. To elucidate molecular mechanisms leading to these epithelial changes, we studied the signaling pathway involved in the modulation of cell migration by CS condensate (CSC) and the infection by a prominent periodontal pathogen, Porphyromonas gingivalis. MATERIAL AND METHODS: Human gingival epithelial cells (Ca9-22) were treated with CSC or vehicle control for 24 h. Activation of mitogen-activated protein kinases (MAPK) in cells with or without infection by P. gingivalis was assessed by polymerase chain reaction array and immunoblotting using phospho-specific antibodies. Cell migration was assessed using in vitro wound closure model, and specific pharmacologic inhibitors of MAPK pathways were used to characterize further the extent of involvement of the MAPK pathways. RESULTS: Polymerase chain reaction array showed that gene expression of several members of the MAPK, particularly p38 and JNK, was upregulated more than twofold in Ca9-22 cells stimulated with 10 µg/mL CSC. Coincubation with P. gingivalis induced a different pattern of gene expression for MAPK pathways, but it did not suppress the MAPK-related genes upregulated by CSC. A significant phosphorylation of ERK1/2 and p38 was observed in cells stimulated with 10 µg/mL CSC (p < 0.05), whereas coincubation with a higher concentration of CSC (250 µg/mL) evoked no such activation. P. gingivalis infection resulted in a tendency to reduce the phosphorylation of ERK1/2 and p38, which had been enhanced by stimulation with 10 µg/mL CSC. Incubation with ERK1/2 and p38 inhibitors significantly reduced the wound closure of CSC-stimulated cells, by approximately 43% and 46%, respectively (p < 0.05). CONCLUSION: CSC exerts effects on the migration of human gingival epithelial cells through the activation of the MAPK ERK1/2 and p38 signaling pathways. P. gingivalis infection attenuates the CSC-induced migration at least partly by suppressing the phosphorylation of ERK1/2 and p38, but other pathways are likely to be involved in this modulatory process.


Assuntos
Movimento Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Gengiva/citologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Nicotiana , Porphyromonas gingivalis/fisiologia , Fumaça , Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Células Epiteliais/microbiologia , Células Epiteliais/fisiologia , Regulação da Expressão Gênica , Gengiva/efeitos dos fármacos , Gengiva/microbiologia , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/farmacologia , Nicotina/efeitos adversos , Fosforilação , Porphyromonas gingivalis/patogenicidade , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima , Cicatrização , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
J Chem Phys ; 144(8): 084904, 2016 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-26931723

RESUMO

Differential Scanning Calorimetry (DSC) and optical polarization microscopy of a mixture of the liquid crystalline material (N-(4-methoxybenzylidene)-4-butylaniline, MBBA) and a Fe-based room temperature ionic liquid 1-ethyl-3-methylimidazolium tetrachloroferrate ([Emim](+) [FeCl4](-), EMIF) indicate a decrease in the nematic-isotropic (N-I) phase transition temperature (T(NI)) with an increase in EMIF concentration, explained by a proposed model of Coulomb "screening" of MBBA quadrupoles by the EMIF ions along with ionic "self screening." DSC studies of EMIF-MBBA and pure EMIF and comparison with pure MBBA results show that the major transitions in pure EMIF have Arrhenius behaviour, but more importantly the previously found convex Arrhenius behaviour of the pristine MBBA [K. Dan et al., Europhys. Lett. 108, 36007 (2014)] becomes Arrhenius in the mixture, indicating a conversion of the entropic N-I activation barrier to an enthalpic one. In presence of EMIF, a drastic decrease in the intensity of out-of-plane distortions of benzene rings in MBBA is found from Fourier transform infrared spectroscopy, consistent with significant reduction in the conformational states of MBBA. This suppression of large amplitude motion is again consistent with a Coulomb screening and gives a molecular basis for the entropic-to-enthalpic conversion of the N-I activation barrier.

6.
Gene Ther ; 22(2): 127-37, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25503692

RESUMO

Age-related macular degeneration (AMD) is a vision-threatening disease characterized by choroidal fibrovascular membrane (FVM) formation, choroidal neovascularization (CNV) and choroidal fibrosis. No safe and effective therapeutic method has been developed for the choroidal fibrosis, although anti-vascular endothelial growth factor therapy can partially shrink the CNV. We recently reported that periostin (POSTN), which is produced by retinal pigment epithelial cells, has an important role in the formation of preretinal FVMs, but its role in choroidal FVMs has not been determined. In this study, we used Postn knockout mice to investigate the role played by POSTN in choroidal FVM formation. In addition, we used a new class of RNA interference (RNAi) agent (NK0144) that targets POSTN and determined its effect on choroidal FVM development. Genetic ablation of Postn had an inhibitory effect not only on CNV formation but also on choroidal fibrosis in a mouse CNV model. NK0144 also had a greater inhibitory effect on both the CNV and choroidal fibrosis than control RNAi with no apparent adverse effects. These findings suggest a causal relationship between POSTN and choroidal FVM formation, and also a potential therapeutic role of intravitreal NK0144 for AMD.


Assuntos
Moléculas de Adesão Celular/genética , Neovascularização de Coroide/terapia , Degeneração Macular/terapia , Interferência de RNA , Animais , Sequência de Bases , Adesão Celular , Moléculas de Adesão Celular/metabolismo , Movimento Celular , Proliferação de Células , Células Cultivadas , Corioide/irrigação sanguínea , Corioide/patologia , Técnicas de Silenciamento de Genes , Terapia Genética , Humanos , Injeções Intravítreas , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Epitélio Pigmentado da Retina/patologia , Epitélio Pigmentado da Retina/fisiologia , Receptor 3 Toll-Like/metabolismo
7.
Br J Cancer ; 111(4): 799-806, 2014 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-25032734

RESUMO

BACKGROUND: Cisplatin and other anticancer drugs are important in the treatment of head and neck squamous cell carcinoma; however, some tumours develop drug resistance. If chemoresistance could be determined before treatment, unnecessary drug administration would be avoided. Here, we investigated chemoresistance factors by comprehensive analyses at the protein level. METHODS: Four human carcinoma cell lines were used: cisplatin-sensitive UM-SCC-23, UM-SCC-23-CDDPR with acquired cisplatin resistance, naturally cisplatin-resistant UM-SCC-81B, and UM-SCC-23/WR with acquired 5-fluorouracil resistance. Extracted proteins were labelled with iTRAQ and analysed by tandem mass spectrometry to identify resistance. Protein expression was confirmed by western blotting and functional analysis was carried out using siRNA. RESULTS: Thirteen multiple-drug resistance proteins were identified, as well as seven proteins with specific resistance to cisplatin, including α-enolase. Differential expression of these proteins in cisplatin-resistant and -sensitive cell lines was confirmed by western blotting. Functional analysis for α-enolase by siRNA showed that cisplatin sensitivity significantly was increased in UM-SCC-81B and slightly in UM-SCC-23-CDDPR but not in UM-SCC-23/WR cells. CONCLUSIONS: We identified proteins thought to mediate anticancer drug resistance using recent proteome technology and identified α-enolase as a true cisplatin chemoresistance factor. Such proteins could be used as biomarkers for anticancer agent resistance and as targets of cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/metabolismo , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Fluoruracila/farmacologia , Neoplasias de Cabeça e Pescoço/metabolismo , Proteoma/metabolismo , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Fosfopiruvato Hidratase/genética , Fosfopiruvato Hidratase/metabolismo , RNA Interferente Pequeno/genética , Receptor Notch1/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço , Coloração e Rotulagem , Espectrometria de Massas em Tandem
8.
Eur J Neurol ; 21(6): 867-73, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24602238

RESUMO

BACKGROUND AND PURPOSE: Several studies have reported moyamoya syndrome associated with thyroid disease, and the mechanism involved in this relationship is unknown. This study aimed to clarify the involvement of thyroid antibodies and thyroid function in intracranial arterial stenosis. METHODS: The study included 30 patients <65 years of age with intracranial arterial steno-occlusion. Patients with definitive moyamoya disease were excluded. Thyroid function and thyroid antibody levels were evaluated. The steno-occlusive site and the presence of moyamoya vessels were evaluated using digital subtraction angiography. The characteristics of intracranial arterial lesions were compared between patients with and without elevated thyroid antibody levels, and between patients with increased thyroid function and those with normal thyroid function. RESULTS: Five patients had increased thyroid function and seven had elevated thyroid antibody levels. Four were diagnosed with Graves' disease, 13 with atherosclerotic intracranial stenosis, two with intracranial arterial dissection, one with vasculitis syndrome and 10 with intracranial stenosis of unknown cause. All patients with Graves' disease and patients with elevated antithyroid peroxidase antibody levels had steno-occlusion in the terminal portion of the internal carotid arteries, whereas most of the patients with normal thyroid function or without elevated thyroid antibody levels had stenosis in the middle cerebral arteries. CONCLUSIONS: In young and middle-aged patients, a lesion in the terminal portion of the internal carotid artery was associated with elevated thyroid antibody levels and increased thyroid function. Stenoses found in the terminal portion of the internal carotid artery and immune-mediated thyroid diseases may share a common background.


Assuntos
Autoanticorpos/sangue , Artéria Carótida Interna/patologia , Estenose das Carótidas/imunologia , Doença de Moyamoya/imunologia , Doenças da Glândula Tireoide/imunologia , Adulto , Estenose das Carótidas/sangue , Estenose das Carótidas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/sangue , Doença de Moyamoya/patologia , Doenças da Glândula Tireoide/sangue , Doenças da Glândula Tireoide/patologia
9.
Infection ; 42(4): 639-47, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24567233

RESUMO

INTRODUCTION: Micafungin (MCFG) is used for the prophylaxis of invasive fungal disease (IFD) after allogeneic hematopoietic stem cell transplantation (HSCT). However, the safety, efficacy, or optimal dosage/blood levels as prophylaxis is uncertain in pediatric HSCT-patients. METHODS: We prophylactically administered MCFG at 2 mg/kg once daily to 38 children and adolescents undergoing allogeneic HSCT. RESULTS: During MCFG prophylaxis, infusion reactions or adverse events (grades 2-5) related to MCFG use were not found in all the patients. Thus, MCFG prophylaxis was not discontinued and other antifungal agents were not added except for 2 patients in whom probable or possible IFDs developed (completion rate, 94.7 %). To elucidate the influence of HSCT-related complications/drugs on blood concentration of MCFG, we determined the plasma trough and peak levels in 13 and 10 among 38 patients, respectively. The mean trough and peak levels were 3.04 ± 1.21 µg/mL (569 samples) and 9.63 ± 3.62 µg/mL (44 samples), respectively. The peak levels were moderately correlated to the trough levels (R (2) = 0.466). In a patient, the trough level of MCFG transiently increased up to 10.21 µg/mL during hepatic dysfunction due to acute graft-versus-host disease. The MCFG trough levels strongly correlated with T-Bil value (R (2) = 0.894). There was no relationship between the trough levels of MCFG and the circulating concentrations of tacrolimus (R (2) = 0.040). Additionally, MCFG levels were not influenced by treatment with cyclophosphamide or corticosteroids. CONCLUSIONS: Prophylaxis with MCFG at 2 mg/kg once daily may be safe, tolerable, and feasible in pediatric HSCT-patients.


Assuntos
Antifúngicos/administração & dosagem , Quimioprevenção/métodos , Equinocandinas/administração & dosagem , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Lipopeptídeos/administração & dosagem , Micoses/prevenção & controle , Adolescente , Antifúngicos/efeitos adversos , Antifúngicos/farmacocinética , Quimioprevenção/efeitos adversos , Criança , Pré-Escolar , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Equinocandinas/efeitos adversos , Equinocandinas/farmacocinética , Feminino , Humanos , Lactente , Lipopeptídeos/efeitos adversos , Lipopeptídeos/farmacocinética , Masculino , Micafungina , Plasma/química
10.
Tech Coloproctol ; 18(7): 647-52, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24500723

RESUMO

BACKGROUND: We evaluated the efficacy and safety of superselective embolization with assistance of colonoscopy for acute colonic hemorrhage. METHODS: Of 92 cases of acute colonic hemorrhage requiring colonoscopic intervention, 11 (12 %) could not be successfully treated. Of these, 10 patients (9 men, mean age 65.5 years, range 39-75 years) underwent superselective embolization. Hemorrhage was caused by diverticular disease (n = 8), polypectomy (n = 1), and vascular malformation (n = 1). In all 10 cases, the radiopaque clips were placed at the bleeding point via colonoscopy. Microcatheters were used in all procedures, and embolization was performed at the level of the vasa recta leading to or near the clips with Gelfoam particles, microcoils, or both. RESULTS: Immediate hemostasis was achieved in all patients. In 6 of 10 patients (60 %), selective angiograms showed no active extravasation at the time of the procedure and the embolization was performed using clips as a landmark. In the remaining four patients, selective angiograms showed active extravasation from the vasa recta leading to the clips. The mean number of embolized vessels with no active extravasation and with active extravasation was 1.83 (range 1-3) and 1.25 (range 1-2), respectively. The mean duration of clinical follow-up was 11.6 months (range 1-29 months). One patient (10 %) bled from a different site than the treated site a month after embolization, but the bleeding ceased after endoscopic intervention. All the patients (100 %) were evaluated for objective evidence of ischemia by colonoscopy. Four of the 10 patients (40 %) were found endoscopically to have small areas of ischemia involving only the mucosa, but they remained asymptomatic. There was no bowel infarction or stricture. CONCLUSIONS: Colonoscopy-assisted superselective embolization may be a safe and useful procedure for acute colonic hemorrhage without active extravasation on angiogram.


Assuntos
Doenças do Colo/terapia , Colonoscopia/métodos , Embolização Terapêutica/métodos , Hemorragia Gastrointestinal/terapia , Doença Aguda , Adulto , Angiografia/métodos , Estudos de Coortes , Colectomia/métodos , Doenças do Colo/diagnóstico por imagem , Doenças do Colo/mortalidade , Feminino , Seguimentos , Hemorragia Gastrointestinal/diagnóstico por imagem , Hemorragia Gastrointestinal/mortalidade , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Recidiva , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
11.
Infection ; 41(1): 219-23, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22971937

RESUMO

BACKGROUND: There have been no reports of human herpesvirus-6 (HHV-6) encephalitis treatment based on both HHV-6 DNA load and the antiviral agent's concentration in the cerebrospinal fluid (CSF). PATIENT: A 20-year-old male with a hematological malignancy developed HHV-6 encephalitis 15 days after unrelated cord blood transplantation (UCBT). He had fever, chest pain, memory impairment, and insomnia. His CSF showed no increased cell counts, but the amount of HHV-6 DNA was elevated to 2.0 × 10(6) copies/ìgDNA. Magnetic resonance imaging (MRI) of the head revealed abnormal high-intensity signals in the left limbic system on T2-weighted and diffusion-weighted images. Intravenous administration of ganciclovir (GCV) was initiated at 5 mg/kg every 12 h on day 18, and was continued until day 137. The amount of HHV-6 DNA in the plasma became undetectable on day 25. The HHV-6 load in the CSF decreased to 1.5 × 10(3) copies/ìgDNA on day 32, and reached undetectable levels on day 53. The mean concentration of GCV 1 h after an infusion of 5 mg/kg was 4.12 mg/mL in plasma and 0.7 mg/mL in CSF. The chest pain and insomnia disappeared on days 35 and 47, respectively. Memory defects recovered up to day 85. CONCLUSION: Serial quantification of HHV-6 DNA in CSF may be useful for successful treatment with GCV in post-transplant HHV-6 encephalitis.


Assuntos
Antivirais/uso terapêutico , Encefalite Viral/tratamento farmacológico , Ganciclovir/uso terapêutico , Herpesvirus Humano 6/isolamento & purificação , Infecções por Roseolovirus/tratamento farmacológico , Adulto , Encéfalo/patologia , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , DNA Viral/líquido cefalorraquidiano , Encefalite Viral/diagnóstico , Encefalite Viral/virologia , Ganciclovir/farmacocinética , Humanos , Imageamento por Ressonância Magnética , Masculino , Infecções por Roseolovirus/diagnóstico , Infecções por Roseolovirus/virologia , Carga Viral , Adulto Jovem
12.
J Chem Phys ; 139(24): 244901, 2013 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-24387390

RESUMO

In general, bio-macromolecules are composed of hydrophilic and hydrophobic moieties and are confined within small cavities, such as cell membranes and intracellular organelles. Here, we studied the self-organization of macromolecules having groups with different affinities to solvents under spherical nano-scale confinement by means of computer modeling. It is shown that depending on the interaction parameters of monomer units composed of side- and main-chain monomer groups along a single linear macromolecule and on cavity size, such amphiphilic polymers undergo the conformational transitions between hollow nanospheres, rod-like and folded cylindrical structures, and a necklace conformation with and without a particular ordering of beads. The diagram of the conformations in the variables the incompatibility parameter of monomer units and the cavity radius is constructed.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Substâncias Macromoleculares/química , Nanopartículas/química , Modelos Moleculares , Conformação Molecular , Termodinâmica
13.
Eur Phys J E Soft Matter ; 34(4): 38, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21509663

RESUMO

In this article, we describe the instability of a contact line under nonequilibrium conditions mainly based on the results of our recent studies. Two experimental examples are presented: the self-propelled motion of a liquid droplet and spontaneous dynamic pattern formation. For the self-propelled motion of a droplet, we introduce an experiment in which a droplet of aniline sitting on an aqueous layer moves spontaneously at an air-water interface. The spontaneous symmetry breaking of Marangoni-driven spreading causes regular motion. In a circular Petri dish, the droplet exhibits either beeline motion or circular motion. On the other hand, we show the emergence of a dynamic labyrinthine pattern caused by dewetting of a metastable thin film from the air-water interface. The contact line between the organic phase and the aqueous phase forms a unique spatio-temporal pattern characterized as a dynamic labyrinth. Motion of the contact line is controlled by diffusion processes. We propose a theoretical model to interpret essential aspects of the observed dynamic behavior.


Assuntos
Água/química , Ar , Compostos de Anilina/química , Biofísica/métodos , Difusão , Cinética , Teste de Materiais , Movimento (Física) , Movimento , Propriedades de Superfície , Tensão Superficial , Tensoativos , Temperatura , Fatores de Tempo
14.
J Exp Med ; 184(3): 893-902, 1996 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9064349

RESUMO

Phagocyte NADPH oxidase, dormant in resting cells, is activated upon cell stimulation to produce superoxide anion, a precursor of microbicidal oxidants. Active NADPH oxidase is found on the membrane as an enzyme complex, composed of membrane-integrated cytochrome b558 (gp91phox and p22phox subunits) and two cytosolic factors (p47phox and p67phox), each of the latter containing two src homology 3 (SH3) domains. Recently, we radioactively identified a third cytosolic factor, p40phox, as a molecule that associates with p67phox in human neutrophils. Although it has been found that this p40phox protein is defective in patients with chronic granulomatous disease (CGD) who lack p67phox, evidence to functionally relate it to the NADPH oxidase system has hitherto been lacking. In this study, we raised separate antibodies against both the COOH- and NH2-terminal polypeptides of p40phox as well as against the COOH-terminal polypeptide of p67phox to examine the mode of interaction between p40phox and p67phox in a complex. The antibody against the COOH terminus of p67phox was able to communoprecipitate p40phox in conjunction with p67phox itself as was expected. Very interestingly, however, the antibody against the COOH terminus of p40phox completely dissociated the p67phox molecule from the p40phox-p67phox complex unit without any detectable coimmunoprecipitation of p67phox, despite their tight association, whereas that against the NH2 terminus of p40phox had absolutely no dissociation effect. Similar results were found regarding their effects on the O2-generating ability of cytosol in a cell-free activation system, i.e., inhibition was noted with the COOH terminus antibody but not with that for the NH2 terminus of p40phox. However, this dissociation did not affect the translocation of the cytosolic components including p47phox to the membrane. Once the NADPH oxidase was activated, the antibody for the COOH terminus did not show any inhibitory effect on catalysis by the activated enzyme. The stimulators of NADPH oxidase, MA and SDS, did not dissociate the p40phox-p67phox complex. These results provide the first demonstration that p40phox is practically involved in the activation of NADPH oxidase through the association of its COOH-terminal, but not its NH2-terminal, with p67phox.


Assuntos
NADH Desidrogenase/metabolismo , NADPH Oxidases/metabolismo , Fagócitos/enzimologia , Fosfoproteínas/metabolismo , Citosol/química , Citosol/metabolismo , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Guanosina Trifosfato/análogos & derivados , Guanosina Trifosfato/metabolismo , Humanos , Imunoglobulina G/metabolismo , Modelos Biológicos , Ácido Mirístico , Ácidos Mirísticos/metabolismo , Neutrófilos/enzimologia , Neutrófilos/metabolismo , Relação Estrutura-Atividade , Superóxidos/metabolismo
15.
Phys Rev Lett ; 105(12): 128302, 2010 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-20867679

RESUMO

We studied the conformational properties of DNA in a salt solution of the strongly charged protein bovine serum albumin. DNA is compacted when a suitable amount of bovine serum albumin is added to the solution due to a crowding effect and strong electrostatic repulsion between DNA and bovine serum albumin, both of which carry negative charges. However, DNA undergoes an unfolding transition with an increase in the salt concentration. This observation contradicts the current understanding of polymer- and salt-induced condensation, ψ condensation. We propose a simple theoretical model by taking into account the competition between the translational entropy of ions and electrostatic interaction.


Assuntos
DNA/química , Soroalbumina Bovina/química , Cloreto de Sódio/química , Entropia , Íons , Microscopia de Fluorescência , Modelos Químicos , Desdobramento de Proteína/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Soluções/química
16.
Clin Nephrol ; 73(1): 76-80, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20040357

RESUMO

The incidence of leptospirosis, or Weil's disease, in developed countries, particularly in temperate regions, has been dramatically decreasing due to recent improvements in the hygienic environment. In these areas, physicians rarely face this disease and inclusion as a differential diagnosis of acute renal failure seems increasingly uncommon. However, we encountered two cases of severe leptospirosis requiring hemodialysis in central Tokyo. Both cases showed hyperbilirubinemia, thrombocytopenia and mental disturbance in addition to acute renal failure. Severe leptospirosis remains associated with high mortality rates, and early clinical suspicion and laboratory confirmation of the disease are crucial. Detailed history-taking suggested that leptospirosis was caused by transmission from rats in both cases. Rodents inhabit most land areas, implying that the disease can occur all over the world, even in huge metropoles such as Tokyo. These two cases indicate the need for awareness of leptospirosis among physicians working even in urban areas of developed countries.


Assuntos
Injúria Renal Aguda/terapia , Diálise Renal , Doença de Weil/diagnóstico , Doença de Weil/terapia , Injúria Renal Aguda/etiologia , Idoso , Animais , Antibacterianos/uso terapêutico , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Tóquio , Resultado do Tratamento , Doença de Weil/complicações , Doença de Weil/transmissão
17.
Minim Invasive Neurosurg ; 53(2): 86-90, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20533142

RESUMO

INTRODUCTION: A new technique using a navigation system to minimize the influence of brain shift and to perform precise resection of brain tumors is demonstrated. To determine the resection plane, one to six tubes were inserted around the tumor under the guidance of a navigation system before dural incision. RESULTS: This technique termed the "navigation-guided fence-post tube" (NGFP) procedure was used to treat 34 patients with intraaxial brain tumors including gliomas (23 cases), malignant lymphomas (4 cases) and metastatic tumors (7 cases). Tumors were removed totally in 23 cases (67.6%), subtotally (95% or more removal) in 6 cases (17.6%) and partially (less than 95% removal) in 5 cases (14.7%). The cases with subtotal or partial resection contained tumors that were close to or involved the eloquent area, or disseminated lesions. No complications due to tube insertion occurred. CONCLUSION: NGFP is a useful and safe technique for brain tumor surgery with no influence of brain shift during tumor resection.


Assuntos
Neoplasias Encefálicas/cirurgia , Glioma/cirurgia , Neuronavegação/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Science ; 368(6486): 67-71, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32193363

RESUMO

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

19.
Science ; 155(3768): 1405-7, 1967 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-6018504

RESUMO

Daily fluctuations of the number of single fallout particles and activity of zirconium-95 in the groundlevel air were measured at Fayetteville (94 degrees W, 36 degrees N), Arkansas, for a period of about 3 months after the Chinese nuclear explosion of 9 May 1966. We found a cyclic pattern of variations for both zirconium-95 and fallout particles; this indicated that they were airborne for a long period and traveled far. Apparently, some of the particles circled the world more than once.


Assuntos
Cinza Radioativa , Zircônio , China , Explosões
20.
Science ; 153(3736): 633-5, 1966 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-17757237

RESUMO

Twenty single particles separated from a 20-liter sample of rain collected in Osaka, Japan, shortly after the 14 May 1965 test explosion of the Chinese nuclear device, were analyzed radiochemically. The abundance pattern of the fission products in these particles resembled the shape of the mass-yield curve for the thermal neutron-induced fission of uranium-235, except for the facts that cesium-hl37 and strontium-90 were markedly depleted and the yields near the symmetric fission region appeared to be somewhat enhanced.

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