RESUMO
La1.5Sr0.5CoMn0.5Fe0.5O6 (LSCMFO) compound was prepared by solid state reaction and its structural, electronic and magnetic properties were investigated. The material forms in rhombohedral [Formula: see text] structure, and the presence of distinct magnetic interactions leads to the formation of a Griffiths phase above its FM transition temperature (150 K), possibly related to the nucleation of small short-ranged ferromagnetic clusters. At low temperatures, a spin glass-like phase emerges and the system exhibits both the conventional and the spontaneous exchange bias (EB) effects. These results resemble those reported for La1.5Sr0.5CoMnO6 but are discrepant to those found when Fe partially substitutes Co in La1.5Sr0.5(Co1-x Fe x )MnO6, for which the EB effect is observed in a much broader temperature range. The unidirectional anisotropy observed for LSCMFO is discussed and compared with those of resembling double-perovskite compounds, being plausibly explained in terms of its structural and electronic properties.
Assuntos
Glutationa Transferase/genética , Mieloma Múltiplo , Polimorfismo de Nucleotídeo Único , Transplante de Células-Tronco , Talidomida/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Autoenxertos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Mieloma Múltiplo/genética , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/terapia , Taxa de SobrevidaRESUMO
The re-composition of deforested environments requires the prior acclimation of seedlings to full sun in nurseries. Seedlings can overcome excess light either through the acclimation of pre-existing fully expanded leaves or through the development of new leaves that are acclimated to the new light environment. Here, we compared the acclimation capacity of mature (MatL, fully expanded at the time of transfer) and newly expanded (NewL, expanded after the light shift) leaves of Guazuma ulmifolia Lam. (Malvaceae) seedlings to high light. The seedlings were initially grown under shade and then transferred to full sunlight. MatL and NewL were used for chlorophyll fluorescence and gas exchange analyses, pigment extraction and morpho-anatomical measurements. After the transfer of seedlings to full sun, the MatL persisted and acclimated to some extent to the new light condition, since they underwent alterations in some morpho-physiological traits and maintained a functional electron transport chain and positive net photosynthesis rate. However, long-term exposure to high light led to chronic photoinhibition in MatL, which could be related to the limited plasticity of leaf morpho-anatomical attributes. However, the NewL showed a high capacity to use the absorbed energy in photochemistry and dissipate excess energy harmlessly, attributes that were favoured by the high structural plasticity exhibited by these leaves. Both the maintenance of mature, photosynthetically active leaves and the production of new leaves with a high capacity to cope with excess energy were important for acclimation of G. ulmifolia seedlings.
Assuntos
Aclimatação/fisiologia , Luz , Malvaceae/crescimento & desenvolvimento , Clorofila/metabolismo , Malvaceae/metabolismo , Malvaceae/efeitos da radiação , Fotossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Floresta ÚmidaAssuntos
Glutationa S-Transferase pi/genética , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/mortalidade , Mutação de Sentido Incorreto , Polimorfismo Genético , Substituição de Aminoácidos , Anticorpos Monoclonais Murinos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Feminino , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Masculino , Prednisona/administração & dosagem , Estudos Prospectivos , Rituximab , Taxa de Sobrevida , Pesquisa Translacional Biomédica , Vincristina/administração & dosagemRESUMO
TsTX is an á-type sodium channel toxin that stimulates the discharge of neurotransmitters from neurons. In the present study we investigated which neurotransmitters are released in the hippocampus after TsTX injection and if they are responsible for electrographic or histopathological effects. Microdialysis revealed that the toxin increased glutamate extracellular levels in the hippocampus; however, levels of gamma-aminobutyric acid (GABA), glycine, 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were not significantly altered. Neurodegeneration in pyramidal cells of hippocampus and electroencephalographic alterations caused by the toxin were blocked by pretreatment with riluzole, a glutamate release inhibitor. The present results suggest a specific activity of TsTX in the hippocampus which affects only glutamate release.
Assuntos
Humanos , Animais , Ratos , Hipocampo , Neurotransmissores , Venenos de Escorpião/toxicidadeRESUMO
Haloperidol is a receptor D2 antagonist frequently used in the treatment of schizophrenic patients. Haloperidol increased prolactin release from anterior pituitary gland, and prolactin modulates immune system activity. Groups of six male and female rats received an acute 2 mg/kg haloperidol treatment (E1), or a long-term (E2) haloperidol treatments (2 mg/kg/day for 21 days); control rats were treated similarly, but with control solution (groups C1 and C2, respectively). In this work long-term haloperidol treatment (E2) increased macrophage spreading, phagocytosis and NO release in male and female rats. However, acute haloperidol treatment (E1) did not change macrophage activity. Corticosterone and prolactin serum levels were increased after acute (E1) and long-term (E2) haloperidol treatments in male and female rats, being this increment higher in female. Macrophage of male and female rats presented the same pattern of alterations after acute and long-term haloperidol treatments. Haloperidol-induced macrophage activation was discussed in the light of a possible indirect effect through prolactin increments in rats, or, alternatively, as a consequence of a direct action of macrophage dopamine receptor.
Assuntos
Antipsicóticos/farmacologia , Corticosterona/sangue , Haloperidol/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Prolactina/sangue , Animais , Feminino , Peróxido de Hidrogênio/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Óxido Nítrico/metabolismo , Fagocitose/efeitos dos fármacos , Ratos , Ratos Wistar , Explosão Respiratória/efeitos dos fármacos , Caracteres Sexuais , Estimulação Química , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Haloperidol is a receptor D2 antagonist frequently used in the treatment of schizophrenic patients. Haloperidol increased prolactin release from anterior pituitary gland, and prolactin modulates immune system activity. Groups of six male and female rats received an acute 2 mg/kg haloperidol treatment (E1), or a long-term (E2) haloperidol treatments (2 mg/kg/day for 21 days); control rats were treated similarly, but with control solution (groups C1 and C2, respectively). In this work long-term haloperidol treatment (E2) increased macrophage spreading, phagocytosis and NO release in male and female rats. However, acute haloperidol treatment (E1) did not change macrophage activity. Corticosterone and prolactin serum levels were increased after acute (E1) and long-term (E2) haloperidol treatments in male and female rats, being this increment higher in female. Macrophage of male and female rats presented the same pattern of alterations after acute and long-term haloperidol treatments. Haloperidol-induced macrophage activation was discussed in the light of a possible indirect effect through prolactin increments in rats, or, alternatively, as a consequence of a direct action of macrophage dopamine receptor.