RESUMO
Increasing evidence suggests that brain tumors arise from the transformation of neural stem/precursor/progenitor cells. Much current research on human brain tumors is focused on the stem-like properties of glioblastoma. Here we show that anaplastic lymphoma kinase (ALK) and its ligand pleiotrophin are required for the self-renewal and tumorigenicity of glioblastoma stem cells (GSCs). Furthermore, we demonstrate that pleiotrophin is transactivated directly by SOX2, a transcription factor essential for the maintenance of both neural stem cells and GSCs. We speculate that the pleiotrophin-ALK axis may be a promising target for the therapy of glioblastoma.
Assuntos
Neoplasias Encefálicas/metabolismo , Carcinogênese/metabolismo , Proteínas de Transporte/genética , Citocinas/genética , Glioblastoma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Quinase do Linfoma Anaplásico , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proteínas de Transporte/metabolismo , Proliferação de Células , Citocinas/metabolismo , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/fisiologia , Fatores de Transcrição SOXB1/metabolismo , Ativação Transcricional , Células Tumorais CultivadasRESUMO
The magnetization distribution in Co2FeSi which has the largest moment per formula unit â¼6 µB of all Heusler alloys, has been determined using polarized neutron diffraction. The experimentally determined magnetization has been integrated over spheres centred on the three sites of the L12 structure giving µ Fe = 3.10(3) µB and µ Co = 1.43(2) µB, results which are slightly lower than the moments in atomic spheres of similar radii obtained in recent LDA + U band structure calculations (Li et al 2010 Chin. Phys. B 19 097102). Approximately 50% of the magnetic carriers at the Fe sites were found to be in orbitals with eg symmetry. This was higher, ≃65%, at the Co sites. Both Fe and Co were found to have orbital moments that are larger than those predicted. Comparison with similar results obtained for related alloys suggests that there must be a finite density of states in both spin bands at the Fermi energy indicating that Co2FeSi is not a perfect half-metallic ferromagnet.
RESUMO
AIM: To study the relationship between age-related maculopathy (ARM) and exposure to sunlight using an objective method. METHODS: In a case-control study of Japanese men aged > or = 50 years (67 controls without ophthalmic disease and 148 with ARM), those with ARM were separated into groups of early (n = 75) and late (n = 73) ARM. Facial wrinkle length and area of hyperpigmentation, which are considered to be associated with exposure to sun, were measured using imaging with computer-based image analysis. Skin tone was also measured on the upper inner arm, which is not exposed to sun. Early and late ARM association with skin measurements was then evaluated. RESULTS: Significantly more facial wrinkling (p = 0.047, odds ratio 3.8; 95% CI 1.01 to 13.97) and less facial hyperpigmentation (p = 0.035, odds ratio 0.3; 95% CI 0.08 to 0.92) was present in late ARM cases. The relationship between skin tone and ARM risk was not statistically significant. CONCLUSIONS: This objective method showed that lifetime exposure to sunlight is an important factor in the progression of late ARM. An individual's reaction to sunlight exposure may have a role in ARM progression in addition to total lifetime exposure to sunlight.
Assuntos
Degeneração Macular/etiologia , Envelhecimento da Pele/efeitos da radiação , Pigmentação da Pele/efeitos da radiação , Luz Solar/efeitos adversos , Fatores Etários , Idoso , Estudos de Casos e Controles , Face , Fundo de Olho , Humanos , Hiperpigmentação/etiologia , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fumar/efeitos adversosRESUMO
We have previously shown that an outer membrane protein, SspA, is prominently induced by salt stress in a photosynthetic bacterium, Rhodobacter sphaeroides f. sp. denitrificans IL106 (R. sphaeroides). In this study, we investigated the physiological role of SspA under various stress conditions. Using recombinant SspA expressed in Escherichia coli as an antigen, the polyclonal antiserum of SspA was prepared. Western blot analysis demonstrated that SspA was highly induced by salt stress under both anaerobic and aerobic conditions. SspA was also induced, but to a lesser extent, by osmotic and acid stress. It is reduced under heat and cold compared to non-stressed conditions. While sspA-disrupted R. sphaeroides grew normally under anaerobic conditions in either the presence or absence of stress, it displayed significantly retarded growth under aerobic conditions in the dark, especially when osmotic or salt stress were imposed. In addition, the sspA disruptant, but not the wild type, formed cell aggregates when grown under both anaerobic and aerobic conditions, and this phenotype was significantly enhanced under salt-stressed aerobic conditions. Together, our findings suggest that SspA is critical under salt-stressed, aerobic growth conditions.
Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Membrana/metabolismo , Rhodobacter sphaeroides/fisiologia , Sais , Ácidos , Aerobiose , Proteínas de Bactérias/fisiologia , Deleção de Genes , Proteínas de Choque Térmico/fisiologia , Proteínas de Membrana/fisiologia , Pressão Osmótica , Rhodobacter sphaeroides/genética , Rhodobacter sphaeroides/crescimento & desenvolvimento , Regulação para CimaAssuntos
Proteínas de Ligação a DNA/genética , Comunicação Interatrial/genética , Mutação/genética , Fatores de Transcrição/genética , Adulto , Sequência de Aminoácidos/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 8/genética , Feminino , Fator de Transcrição GATA4 , Ligação Genética/genética , Marcadores Genéticos/genética , Haplótipos/genética , Humanos , Escore Lod , Masculino , Dados de Sequência Molecular , Linhagem , Estenose da Valva Pulmonar/genéticaRESUMO
AIMS: To describe the clinical and histopathological findings in a patient with polypoidal choroidal vasculopathy. METHODS: A 76 year old Japanese man had a discrete, orange-red lesion of 1 disc diameter in the macula, with the fluorescein and indocyanine green angiographic and optical coherence tomographic findings compatible with polypoidal choroidal vasculopathy. He underwent a surgical removal of the macular lesion, followed by light and electron microscopic examinations. RESULTS: The histopathological examination revealed that the specimen consisted of degenerated retinal pigment epithelium-Bruch's membrane-choriocapillaris complex and inner choroid. A tortuous, unusually dilated venule was present adjacent to an arteriole with marked sclerotic changes, appearing to form arteriovenous crossing. These vessels seemed to represent native inner choroidal vessels, and had haemorrhage per diapedesis. Blood cells and fibrin filled the lumina of the vessels and accumulated in the extravascular spaces, indicating vascular stasis. CONCLUSION: Hyperpermeability and haemorrhage due to stasis of a dilated venule and an arteriole involved by sclerosis at the site where they cross in the inner choroid might cause oedema and degeneration of the tissue. Voluminous accumulation of blood cells and fibrin might generate elevation of tissue pressure sufficient to displace the weakened lesion anteriorly. The result suggests that the polypoidal vessels in this case represent abnormality in the inner choroidal vasculature.
Assuntos
Neoplasias da Coroide/patologia , Corioide/irrigação sanguínea , Neovascularização de Coroide/patologia , Pólipos/patologia , Idoso , Corioide/patologia , Corioide/ultraestrutura , Neoplasias da Coroide/ultraestrutura , Angiofluoresceinografia/métodos , Humanos , Macula Lutea/patologia , Degeneração Macular/patologia , Masculino , Microscopia Eletrônica/métodos , Pólipos/ultraestruturaRESUMO
The gene encoding a membrane protein, SspA, induced under salt stress conditions was cloned and sequenced from a photosynthetic bacterium, Rhodobacter sphaeroides f. sp. denitrificans IL106. A single open reading frame consisting of 972 base pairs that encoded a polypeptide composed of a signal peptide of 24 amino acids and a mature protein of 300 amino acids (Mr 33,386) was found. A database search failed to detect any highly homologous sequences, indicating that SspA is a novel protein. The protein was present in the outer membrane as a transmembrane protein and was specifically induced by salt stress, but not by heat shock.
Assuntos
Proteínas de Bactérias , Clonagem Molecular , Proteínas de Choque Térmico/genética , Proteínas de Membrana/genética , Rhodobacter sphaeroides/metabolismo , Análise de Sequência de DNA , Cloreto de Sódio/farmacologia , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Rhodobacter sphaeroides/efeitos dos fármacos , Rhodobacter sphaeroides/genéticaRESUMO
We report two cases of cerebral infarction in which swallowing function improved following swallowing rehabilitation. Patient 1 was an 82-year-old man, who was admitted due to rheumatoid arthritis and multiple cerebral infarction, suffering from aspiration pneumonia. The abnormality of swallowing was assessed by the water swallowing test and videofluorography. It has been reported that videofluorography is useful in the diagnosis of aspiration. Three weeks after the start of swallowing rehabilitation, the serum level of inflammatory markers and the chest X-ray had returned to normal. His score on the water swallowing test had improved. Patient 2 was a 68-year-old [correction of 62] man, who was admitted with severe hemiplegia, dysphagia and dysarthria. One month after the swallowing rehabilitation, videofluorography showed that the magnitude of aspiration into the trachea had decreased and the pooling of barium in the piriform sinus had disappeared. The patient could begin taking a little food by mouth. These results suggest that swallowing rehabilitation will be affect the clinical improvement of swallowing function and help preventing aspiration pneumonia in our hospital.
Assuntos
Infarto Cerebral/reabilitação , Deglutição/fisiologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/prevenção & controle , Humanos , MasculinoRESUMO
Anti-viral activities of Agaricus blazei Murill were investigated. The water extracts of the cultured mycelia and fruiting bodies were fractionated with different concentrations of ethanol. To several viruses which have cytopathic effects (CPE) on VERO cells, inhibition of these effects by the ethanol fractions was tested. Strong inhibition of CPE induced by western equine encephalitis (WEE) virus was observed in the mycelial fractions but not those of fruiting bodies.
Assuntos
Agaricus/química , Antivirais/farmacologia , Vírus da Encefalite Equina do Oeste/efeitos dos fármacos , Vírus da Encefalite Equina do Oeste/patogenicidade , Agaricus/crescimento & desenvolvimento , Animais , Antivirais/isolamento & purificação , Chlorocebus aethiops , Efeito Citopatogênico Viral/efeitos dos fármacos , Células VeroRESUMO
Water extracts of the mycelial culture and fruiting bodies of Agaricus blazei Murill were fractionated by ethanol precipitation using various ethanol concentrations. Original water extracts from mycelia (Fraction A-0) and fruiting bodies (Fraction B-0) induced TNF-alpha secretion by macrophages derived from rat bone marrow. Fractions B-4 and B-5 obtained from ethanol precipitation of fruiting bodies using 44% and 50% ethanol, respectively, and Fraction B-6 obtained from the supernatant at 50% ethanol markedly induced TNF-alpha secretion. Similar effects were observed in IL-8 secretion by macrophages. Regarding nitric oxide (NO), Fraction B-5 induced a significant increase in NO secretion and Fractions B-4 and B-6 induced slightly NO secretion. Northern blot analysis showed that the increases in cytokine- and NO secretion were due to an increase in cytokine mRNAs or NO synthase mRNA. Therefore, it is concluded that Agaricus blazei Murill components which activate macrophages result in the induction of cytokine- and NO secretion in vitro.
Assuntos
Interleucina-8/metabolismo , Macrófagos/imunologia , Óxido Nítrico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Agaricus/imunologia , Animais , Northern Blotting/métodos , Células Cultivadas , Fracionamento Químico , Ativação de Macrófagos/imunologia , Macrófagos/citologia , Macrófagos/microbiologia , Ratos , SoluçõesRESUMO
Heat shock proteins (HSPs) 60 and 10 are stress-inducible mitochondrial matrix proteins that form a chaperonin complex that is important for mitochondrial protein folding and function. The effect of cerebral ischemia on mitochondrial HSPs is unclear. The topographical and chronological patterns of HSP60 and HSP10 messenger ribonucleic acid (mRNA) expression and induction were investigated in the rat focal cerebral ischemia model. Focal cerebral ischemia was produced by transient middle cerebral artery occlusion for 30 or 90 min. Expression of mRNAs was analyzed using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. RT-PCR analysis showed that both HSP60 and HSP10 mRNA levels increased significantly in the ischemic cortex from 4 to 24 h of reperfusion after 30 min of occlusion. In situ hybridization analysis demonstrated significant induction of both mRNAs in the whole ischemic cortex after 30 min of occlusion and in the dorsomedial border (penumbra) of the ischemic cortex and ipsilateral hippocampus after 90 min of occlusion. Expression patterns and the timing of the induction of both HSP60 and HSP10 mRNAs were identical throughout the experiments. Simultaneous induction of the mRNAs for the mitochondrial chaperonins, HSP60 and HSP10, in various regions in focal cerebral ischemia demonstrates that mitochondrial stress conditions persist concomitantly with cytosolic stress conditions in focal cerebral ischemia.
Assuntos
Chaperonina 10/genética , Chaperonina 60/genética , Ataque Isquêmico Transitório/fisiopatologia , Animais , Northern Blotting , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/fisiopatologia , Regulação da Expressão Gênica/fisiologia , Hipocampo/irrigação sanguínea , Hipocampo/fisiopatologia , Hibridização In Situ , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The simultaneous determination of betaines, the key compounds for osmotic regulation in plants, was established by capillary electrophoresis (CE). After four betaines, glycine betaine (GB), beta-alanine betaine (AB), proline betaine (PB), and 2-hydroxyproline betaine (HPB), were esterified with p-bromophenacyl bromide, the esters were electrophoresed in 100 mM sodium phosphate at pH 3.0. A low-pH condition in CE and esterification gave an advantage of resolving each of the ester peaks as well as those of the unreacted reagent and other components. Furthermore, the addition of 4% polyethylene glycol (PEG) gave a better resolution of 4 peaks, resulting in the separation of the overlapped peaks of PB and AB. It was found from the standard addition method being applied to barley leaves that the GB content in plants could be evaluated by using a calibration curve of the GB standard solution. The extraction of GB from plant leaves was also improved by adopting water as the extraction solvent instead of a mixture of organic solvents. The present method was suitably applied to actual plant specimens collected from a saline area of China.
Assuntos
Betaína/análise , Plantas/química , Acetonitrilas/química , Calibragem , China , Eletroforese Capilar , Ésteres/química , Reprodutibilidade dos Testes , SolventesRESUMO
A low pH capillary electrophoresis (CE) was used for the measurement of free choline in plant leaves. Choline in the leaf extract was first converted to the benzoyl ester and put into CE. A well-resolved peak in the electropherogram was easily obtained. Involvement of enzymes in a two-step oxidation of choline to glycine betaine was evaluated in different plant species with the same method developed for glycine betaine and betaine aldehyde.
Assuntos
Colina/análise , Eletroforese Capilar/métodos , Folhas de Planta/química , Colina/metabolismo , Fabaceae/metabolismo , Glicina/metabolismo , Gossypium/metabolismo , Concentração de Íons de HidrogênioRESUMO
The salt-mediated-stress response in Rhodobacter sphaeroides f. sp. denitrificans IL 106 was investigated by culturing cells in the presence and in the absence of NaCl in growth media. Fractionation of cells followed by SDS-PAGE and 2D-PAGE revealed an increase in the levels of membrane proteins of 39 and 50 kDa and a decrease in the level of a membrane protein of 52 kDa with increasing levels of external NaCl. The proteins were isolated and sequenced. The polypeptide of 50 kDa in the inner membrane was assigned to an ATP synthase beta chain and that of 52 kDa in the outer membrane to a flagellar filament protein. As the N terminal of the 39 kDa protein in the outer membrane was blocked, partial proteolysis was carried out and four peptides were sequenced. Each sequence exhibited no significant homology with those available in databases, suggesting that the polypeptide of 39 kDa (named SspA) is a novel salt-stress-induced protein.
RESUMO
Several investigations have postulated evidence of the involvement of apoptosis in delayed neuronal death following brief periods of global cerebral ischemia. Apoptosis may be closely linked to mitochondrial dysfunction. Heat shock protein (HSP) 60 and HSP10 are mitochondrial matrix proteins induced by stress and form the chaperonin complex that is implicated in protein folding and assembly within the mitochondria. This study investigated the induction of these mitochondrial stress protein genes in the hippocampal CA1 region and less vulnerable regions following transient forebrain ischemia. In situ hybridization analysis revealed that the induction pattern of HSP60 mRNA was identical to that of HSP10 mRNA throughout the entire ischemic course. No changes occurred in the expression of both mRNAs after 2 min ischemia. Strong induction of both mRNAs occurred in the CA1 region after 10 min ischemia and persisted until 1 d after reperfusion. In contrast, induction of both mRNAs in the less vulnerable regions was terminated by 1 d after reperfusion. These results demonstrate that mitochondrial stress conditions persist concomitantly with cytosolic stress conditions in regions vulnerable to transient forebrain ischemia.
Assuntos
Isquemia Encefálica/genética , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Mitocôndrias/genética , Prosencéfalo/metabolismo , Prosencéfalo/patologia , Animais , Apoptose , Northern Blotting , Isquemia Encefálica/patologia , Chaperonina 10/genética , Chaperonina 60/genética , Hipocampo/metabolismo , Hipocampo/patologia , Hibridização In Situ , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos WistarRESUMO
PURPOSE: To determine the structural changes in the retinal pigment epithelium (RPE) and neighboring structures induced by intravitreal injection of a lysosomal protease inhibitor. METHODS: Eleven-week-old Sprague-Dawley rats were injected with 5 microliter of a lysosomal protease inhibitor, E-64 (2.22 microM), intravitreally once and killed at 24 hours, 48 hours, or 7 days later. Others received two or three injections at 48-hour intervals or three daily injections, and killed at 1, 4, and 7 days after the last injection. Eyes were enucleated and retinal tissues were processed for light and electron microscopy. RESULTS: A single injection of E-64 caused only a transient accumulation of phagosome-like and phagolysosome-like inclusion bodies in the RPE. By contrast, repeated injection caused progressive accumulation of these inclusions followed by altered RPE cell conformation, and changes in organelles such as loss of smooth endoplasmic reticulum (SER). This was accompanied by shortening and loss of photoreceptor outer segments without prior dysmorphic changes, alteration of choroidal capillaries, and invasion of Bruch's membrane by fibroblasts and pericytes. Intravitreal injection of vehicle as control induced no structural changes. CONCLUSIONS: E-64 treatment induced structural changes in the outer retina. The causal relationship between accumulation of inclusions in RPE and changes in other subcellular organelles and neighboring cells systems is not clear. However, there are possible explanations: physical disturbance of organelles, particularly SER by inclusions; cellular damage by consequent upon accumulation of A2-E; or, shortage of recycled material due to reduced degradation of phagosomes.
Assuntos
Catepsinas/antagonistas & inibidores , Corpos de Inclusão/ultraestrutura , Leucina/análogos & derivados , Epitélio Pigmentado Ocular/ultraestrutura , Animais , Inibidores de Cisteína Proteinase/farmacologia , Granuloma de Corpo Estranho/patologia , Corpos de Inclusão/efeitos dos fármacos , Injeções , Leucina/farmacologia , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , Células Fotorreceptoras de Vertebrados/ultraestrutura , Epitélio Pigmentado Ocular/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
The nitrous oxide reductase from the photodenitrifier, Rhodobacter sphaeroides f. sp. denitrificans IL106, has been purified under anaerobic conditions. The specific activity of the enzyme was 78 micromol nitrous oxide reduced per min per mg protein, which was approximately 80% higher than that of the aerobic form. The enzyme purified anaerobically retained most of its activity after aerobic storage at 4 degrees C for 2 months without any additives. Visible absorption spectra of the Rhodobacter nitrous oxide reductase resembled those of the enzymes from other origins. The enzyme retained its activity after reduction with sodium dithionite, and the enzyme activity could be determined using dithionite-reduced benzyl viologen. Turnover-dependent inactivation of the enzyme was suppressed by complete removal of oxygen from the reaction mixture, and promoted by zinc ions.
Assuntos
Oxirredutases/isolamento & purificação , Rhodobacter sphaeroides/enzimologia , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Peso Molecular , Oxirredutases/química , Oxirredutases/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
PURPOSE: To study the correlations between age, Bruch's membrane (BM) thickness, retinal pigment epithelial (RPE) autofluorescence, and RPE residual body content. METHODS: Eight-millimeter-diameter macular discs from 88 unpaired human eye bank eyes were obtained within 72 hours of death, fixed in 10% neutral buffered formalin, and hemisected horizontally. One portion of the macular disc was embedded in paraffin and stained with periodic acid-Schiff for the measurement of BM thickness. RPE autofluorescence measurements were performed on unstained, deparaffinized sections. A second portion of the macular disc was prepared for electron microscopy to evaluate RPE residual body content. Linear and polynomial regression techniques were used to investigate the correlations between age, BM thickness, RPE autofluorescence, and RPE residual body content. RESULTS: Bruch's membrane thickness increased with age according to the linear model. RPE autofluorescence and RPE residual body content also increased with age, but the correlations were best approximated by a quadratic model. The correlations between RPE autofluorescence and residual body content and between BM thickness and RPE autofluorescence were best approximated by a linear regression model. There was considerable variation in these correlations between specimens and within the same age group. CONCLUSIONS: Although the changes in RPE and Bruch's membrane increased with age and there was a direct correlation between changes in the two tissues, there was considerable variation within each age group and between specimens. This probably reflects the multifactorial nature of the process.
Assuntos
Envelhecimento/fisiologia , Lâmina Basilar da Corioide/anatomia & histologia , Epitélio Pigmentado Ocular/anatomia & histologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lâmina Basilar da Corioide/fisiologia , Criança , Pré-Escolar , Fluorescência , Humanos , Lactente , Melanossomas/ultraestrutura , Pessoa de Meia-Idade , Epitélio Pigmentado Ocular/fisiologiaRESUMO
The anti-lipolysis by ginseng polypeptide and its modified peptides was examined using porcine adipose cells. Ginseng polypeptides modified by amino acid substitution or proteolyzation reduced or lost the inhibiting activity of adrenalin-induced lipolysis. Correlation between the anti-lipolytic activity of ginseng polypeptide and its Mg(2+)- and ribose-binding activities is discussed.