Neurosyphilis manifesting with rapidly progressive dementia: report of three cases.

Neurosyphilis is rather an unusual cause of dementia characterized by a rapidly progressive course and psychiatric symptoms. Diagnosis of neurosyphilis should be suspected in the presence of a global cognitive impairment consisting in disorientation, amnesia and severe impairment of speech and judgement and psychiatric symptoms such as depression, mania and psychosis, with a subacute onset. More commonly, clinical manifestations of neurosyphilis include general PARESIS (involvement of Personality, Affect, Reflexes, Eye, Sensorium, Intellect and Speech). Upon clinical suspicion, diagnosis of neurosyphilis is confirmed by a reactive cerebrospinal fluid (CSF)-Venereal Disease Research Laboratory. Here we report three Human Immunodeficiency Virus (HIV)-negative male patients presenting with psychiatric symptoms and a rapidly evolving dementia. Although magnetic resonance imaging did not address to diagnosis, CSF examination was mandatory in neurosyphilis diagnosis. Other diagnostic tools such as neuropsychology and single-photon emission computed tomography resulted supportive in the diagnosis. We showed that a prompt antibiotic treatment might stop disease progression. Therefore, neurosyphilis should be always considered even in HIV-negative patients in the presence of unexpected psychiatric symptoms accompanied by a rapidly evolving cognitive decline.

Two-dimensional core-shell donor-acceptor assemblies at metal-organic interfaces promoted by surface-mediated charge transfer.

Organic charge transfer (CT) complexes obtained by combining molecular electron donors and acceptors have attracted much interest due to their potential applications in organic opto-electronic devices. In order to work, these systems must have an electronic matching - the highest occupied molecular orbital (HOMO) of the donor must couple with the lowest unoccupied molecular orbital (LUMO) of the acceptor - and a structural matching, so as to allow direct intermolecular CT. Here it is shown that, when molecules are adsorbed on a metal surface, novel molecular organizations driven by surface-mediated CT can appear that have no counterpart in condensed phase non-covalent assemblies of donor and acceptor molecules. By means of scanning tunneling microscopy and spectroscopy it is demonstrated that the electronic and self-assembly properties of an electron acceptor molecule can change dramatically in the presence of an additional molecular species with marked electron donor character, leading to the formation of unprecedented core-shell assemblies. DFT and classical force-field simulations reveal that this is a consequence of charge transfer from the donor to the acceptor molecules mediated by the metallic substrate.

Cytotoxic and cytostatic activity of copper(II) complexes. Importance of the speciation for the correct interpretation of the in vitro biological results.

The cytotoxicity of some copper(II) compounds against the mouse cancer cell line B16, murine L929, human KB cells, and fibroblasts was investigated. All the copper(II) systems tested were shown to have pronounced toxicity against transformed cells and a cytostatic effect against untransformed cells, i.e., human fibroblasts. A careful speciation of the actual in vitro conditions reveals that copper(II) is essentially present as mixed complexes formed with the amino acids of the culture medium, [Cu(glutamine)(histidine)] being the main species. It was found that the cytotoxic activity is related to the amount of copper(II) contained in the tested compounds.