RESUMO
A high-resolution x-ray imaging crystal spectrometer, whose concept was tested on NSTX and Alcator C-Mod, is being designed for the large helical device (LHD). This instrument will record spatially resolved spectra of helium-like Ar(16+) and will provide ion temperature profiles with spatial and temporal resolutions of <2 cm and ≥10 ms, respectively. The spectrometer layout and instrumental features are largely determined by the magnetic field structure of LHD. The stellarator equilibrium reconstruction codes, STELLOPT and PIES, will be used for the tomographic inversion of the spectral data.
RESUMO
OBJECTIVES: To determine the cytotoxicity of valproic acid (VPA) and its metabolite, 4-ene-valproic acid (4-ene-VPA) in human hepatoblastoma cells (Hep G2), and to study the modulatory effect of cytochrome P450 2E1 induction in this model. METHODS: Cells were exposed to VPA or 4-ene-VPA in the presence of either ethanol (EtOH), or EtOH combined with disulphiram (DS). Some cells were exposed to alpha-fluoro-VPA or to alpha-fluoro-4-ene-VPA in the absence of CYP2E1 inducers. Apoptosis and necrosis were measured by analyzing 6000 cells per sample using transmission electron microscopy, while cytokine release and apoptosis were quantitated by ELISA. RESULTS: VPA + EtOH increased VPA cytotoxicity. 4-ene-VPA + EtOH significantly increased toxicity, while DS + EtOH significantly reduced this toxicity. Alpha-fluorinated analogues reduced cytotoxicity compared to the corresponding VPA compounds. Neither VPA nor alpha-fluorinated VPA increased the release of IL-6 or TNF-alpha in media. A significant increase in the release of TNF-alpha was observed in cells exposed to 4-ene-VPA that further increased with EtOH exposure. CONCLUSIONS: Cells exposed to 4-ene-VPA experience greater cytotoxicity than those treated with VPA. Cytochrome P450 2E1 inducers enhance toxicity in VPA-exposed cells, while alpha-fluorination of VPA diminishes cytotoxicity by directly interfering with the beta-oxidation of the 4-ene-VPA metabolite.
Assuntos
Anticonvulsivantes/toxicidade , Citocromo P-450 CYP2E1/metabolismo , Fígado/efeitos dos fármacos , Ácido Valproico/toxicidade , Apoptose , Sobrevivência Celular/efeitos dos fármacos , Citocromo P-450 CYP2E1/biossíntese , Indução Enzimática , Humanos , Interleucina-6/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Fígado/ultraestrutura , Microscopia Eletrônica , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Sixty-two of 95 units within the vestibular nuclei of 24 hooded, Long-Evans rats were found to respond to both linear accelerations on a parallel swing and to linear movements of the visual field. The addition of visual clues during periods of linear accelerations produced a phase shift in the majority of the units towards the maximal acceleration of the animal, and an increase in the peak activity during the periods of maximal acceleration. Conflicting visual-vestibular stimulation resulted in reduced directional sensitivity and lower rates of firing in visually sensitive units.
Assuntos
Cinestesia/fisiologia , Percepção de Movimento/fisiologia , Núcleos Vestibulares/fisiologia , Percepção Visual/fisiologia , Animais , Mapeamento Encefálico , Eletrofisiologia , Ratos , Vestíbulo do Labirinto/fisiologia , Vias Visuais/fisiologiaRESUMO
The haematological indices in 50 patients with homozygous sickle cell (SS) disease and avascular necrosis of the femoral head and in 180 patients with SS disease without this complication have been compared. Avascular necrosis of the femoral head was significantly associated with high total haemoglobin levels and with low fetal haemoglobin levels. Low fetal haemoglobin levels are associated with increased intravascular sickling. These results suggest that both intravascular sickling and the increased viscosity associated with high haemoglobin levels are related to the development of avascular necrosis of the femoral head in SS disease.
Assuntos
Anemia Falciforme/sangue , Necrose da Cabeça do Fêmur/sangue , Adulto , Anemia Falciforme/complicações , Contagem de Eritrócitos , Índices de Eritrócitos , Feminino , Necrose da Cabeça do Fêmur/complicações , Hemoglobina Fetal/análise , Hemoglobina A2/análise , Humanos , MasculinoRESUMO
The haematological indices in 50 patients with homozygous sickle cell (SS) disease and avascular necrosis of the femoral head and in 180 patients with SS disease without this complication have been compared. Avascular necrosis of the femoral head was significantly associated with high total levels and with low fetal haemoglobin levels. Low fetal haemoglobin levels are associated with increased intravascular sickling. These results suggest that both intravascular sickling and the increased viscosity associated with high haemoglobin levels are related to the development of avascular necrosis of the femoral head in SS disease. (AU)
