Cytotoxic activities of new iron(III) and nickel(II) chelates of some S-methyl-thiosemicarbazones on K562 and ECV304 cells

The S-methyl-thiosemicarbazones of the 2- hydroxy-R-benzaldehyde (R= H, 3-OH 3-OCH3 or 4-OCH3) reacted with the corresponding aldehydes in the presence of FeCl3 and NiCl2. New ONNO chelates of iron(III) and nickel (II) with hydroxy- or methoxy-substitued N1,N4-diarylidene-Smethyl- thiosemicarbazones were characterized by means of elemental analysis, conductivity and magnetic measurements, UV-Vis, IR and 1H-NMR spectroscopies. Cytotoxic activities of the compounds were determined using K562 chronic myeloid leukemia and ECV304 human endothelial cell lines by MTT assay. It was determined that monochloro N1-4- methoxysalicylidene-N4-4-methoxysalicylidene-S-methylthiosemicarbazidato- iron(III) complex showed selective anti-leukemic effects in K562 cells while has no effect in ECV304 cells in the 0.53 μg/ml (IC50) concentrations. Also, some methoxy-substitued nickel(II) chelates exhibit high cytotoxic activitiy against both of these cell lines in low concentrations. Cytotoxicity data were evaluated depending on cell lines origin and position of the substituents on aromatic rings

PET Imaging in Altered States of Consciousness: Coma, Sleep, and Hypnosis

peer reviewedPositron emission tomography (PET) allows studies of cerebral metabolism and blood flow and has been widely used to investigate physiological mechanisms underlying altered states of consciousness. Consciousness is characterized by two components: wakefulness and awareness. In this chapter, we review the current literature on brain metabolism during pathological loss of consciousness (vegetative/unresponsive or minimally conscious states), sleep (in healthy subjects and in patients with insomnia), and under hypnosis. By identifying brain areas specifically involved in conscious processing, these studies have contributed to our understanding of the underlying physiology of consciousness. The precuneal and cingulate cortices, for example, seem to be key areas for maintaining conscious awareness. FDG-PET further allowed the identification of the minimal energetic requirement for conscious awareness in this population, which corresponds to 42% of normal cortical activity. Up to now, it is the most accurate neuroimaging tool regarding the diagnosis of patients with disorders of consciousness. In the future, its use as part of multimodal assessment could improve diagnosis and prognosis in this challenging population. In sleep, a greater activity of the precuneus/posterior cingulate cortex and the fronto-parietal areas during non rapid eye movement sleep also seems to play a role in disorders such as insomnia. Other areas such as the hypothalamus, amygdala, or temporo-occipital cortex seem to play a role in different states such as rapid eye movement sleep and hypnosis. PET studies permit a better comprehension of the neural correlates of consciousness and to identify the implication of specific neural areas and networks in altered states of consciousness in post-comatose patients, sleep and induced hypnosis