Publications by authors named "Giovanna Guiso"

Juveniles (50 days post hatch) of a native cyprinid fish (Barbus plebejus) were exposed for 7 months to sediments from the River Lambro, a polluted tributary impairing the quality of the River Po for tens of kilometers from their confluence. Sediments were collected upstream of the city of Milan and downstream at the closure of the drainage basin of the River Lambro. Chemical analyses revealed the presence of a complex mixture of bioavailable endocrine-active chemicals, with higher exposure levels in the downstream section of the tributary.

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Tetrahydrohyperforin (IDN-5706) is a semisynthetic derivative of hyperforin, one of the main active components of Hypericum perforatum extracts. It showed remarkable positive effects on memory and cognitive performances in wild-type mice and in a transgenic mouse model of Alzheimer's disease, but little was known about the concentrations it can reach in the brain. The investigations reported herein show that repeated treatment of mice with tetrahydrohyperforin (20 mg/kg intraperitoneally, twice daily for 4 days and once on the fifth day) results in measurable concentrations in the brain, up to 367 ng/g brain (∼700 nM) 6 h after the last dose; these concentrations have significant effects on synaptic function in hippocampal slices.

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Background: The kynurenine pathway (KP) is the major route of tryptophan (TRP) catabolism and is activated by inflammation and after cardiac arrest in animals. We hypothesized that the KP activation level correlates with severity of post-cardiac arrest shock, early death, and long-term outcome.

Methods And Results: Plasma was obtained from 245 patients enrolled in a prospective multicenter observational study in 21 intensive care units in Finland.

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Memory loss is one of the key features of cognitive impairment in either aging, Mild Cognitive Impairment (MCI) or dementia. Pharmacological treatments for memory loss are today focused on addressing symptomatology. One of these approved compounds is memantine, a partial NMDA receptor antagonist that has proved its beneficial effects in cognition.

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Oxidative stress and mitochondrial impairment are the main pathogenic mechanisms of Amyotrophic Lateral Sclerosis (ALS), a severe neurodegenerative disease still lacking of effective therapy. Recently, the coenzyme-Q (CoQ) complex, a key component of mitochondrial function and redox-state modulator, has raised interest for ALS treatment. However, while the oxidized form ubiquinone10 was ineffective in ALS patients and modestly effective in mouse models of ALS, no evidence was reported on the effect of the reduced form ubiquinol10, which has better bioavailability and antioxidant properties.

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Abstract Doxycycline inhibits amyloid formation in vitro and its therapeutic efficacy is under evaluation in clinical trials for different protein conformational diseases, including prion diseases, Alzheimer's disease and transthyretin amyloidosis. In patients on chronic hemodialysis, a persistently high concentration of β2-microglobulin causes a form of amyloidosis (dialysis-related amyloidosis, DRA) localized in bones and ligaments. Since doxycycline inhibits β2-microglobulin fibrillogenesis in vitro and accumulates in bones, DRA represents an ideal form of amyloidosis where doxycycline may reach a therapeutic concentration at the site of amyloid deposition.

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Dyes like CR are able to inhibit the aggregation of Aβ fibrils. Thus, a screening of a series of dyes including ABBB (1) was performed. Its main component 2 tested in an in vitro assay (i.

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Despite recent progress in the fight against malaria, the emergence and spread of drug-resistant parasites remains a serious obstacle to the treatment of infections. We recently reported the development of a novel antimalarial drug that combines the 4-aminoquinoline pharmacophore of chloroquine with that of clotrimazole-based antimalarials. Here we describe the optimization of this class of hybrid drug through in-depth structure-activity relationship studies.

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Antimalarial agents structurally based on novel pharmacophores, synthesized by low-cost synthetic procedures and characterized by low potential for developing resistance are urgently needed. Recently, we developed an innovative class of antimalarials based on a polyaromatic pharmacophore. Hybridizing the 4-aminoquinoline or the 9-aminoacridine system of known antimalarials with the clotrimazole-like pharmacophore, characterized by a polyarylmethyl group, we describe herein the development of a unique class (4a-l and 5a-c) of antimalarials selectively interacting with free heme and interfering with Plasmodium falciparum (Pf) heme metabolism.

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We examined the blood-brain barrier (BBB) function in methylazoxymethanol acetate (MAM)-treated rats, a model of human developmental brain malformations. We found aberrant vessels morphology and serum albumin leakage in the heterotopic (malformed) hippocampus; these changes were associated with a significant increase in endothelial P-glycoprotein (P-gp) expression. Seizures exacerbated BBB leakage and greatly augmented P-gp expression in vessels and additionally in perivascular/parenchymal astrocytes.

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Previous structure-activity relationship studies in the search for a potent, noncompetitive alpha-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor antagonist led to 2,3-dimethyl-6-phenyl-12H-[1,3]dioxolo[4,5-h]imidazo[1,2-c][2,3]benzodiazepine (ZK 187638). However, the first synthesis had some drawbacks regarding reagents, processes, and overall yield, which furthermore decreased when the synthesis was scaled up. Therefore, we now report a new synthetic route for this compound which requires fewer steps and is suited for large-scale production.

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Pharmacoresistance in epileptic patients may be ascribed to at least two, not mutually exclusive, mechanisms: a pharmacokinetic mechanism and a decreased sensitivity or availability of targets to antiepileptic drugs (AEDs; i.e., carbamazepine and phenytoin (CBZ, PHT)).

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Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder involving the selective degeneration of motor neurons. In a small proportion of patients, ALS is caused by mutations in copper/zinc superoxide dismutase (SOD1), and mice overexpressing SOD1(G93A) mutant develop a syndrome that closely resembles the human disease. Excitotoxicity mediated by glutamate AMPA receptors has been suggested to be implicated in the selective susceptibility of motor neurons occurring in ALS.

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Purpose: We measured the brain-to-plasma partition of 10,11-dihydro-10-hydroxy-5H-dibenzo(b,f)azepine-5-carboxamide (10-OHCBZ) in epilepsy patients undergoing surgery to alleviate drug-resistant seizures and administered with different oral doses of oxcarbazepine (OXC). We addressed the possible contribution of the multidrug transporter P-glycoprotein (P-gp or MDR1) in determining 10-OHCBZ brain levels by measuring whether this active metabolite is a substrate of P-gp and the relation between the level of expression of MDR1 and the drug concentration in the same brain tissue specimens.

Methods: Steady-state plasma and brain concentrations (C(ss)) of 10-OHCBZ were determined intraoperatively in 11 patients by high-performance liquid chromatography (HPLC) with UV detection.

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Hyperforin is one of the possible active principles mediating the antidepressant activity of Hypericum perforatum L. extracts. The ester derivative IDN 5491 (hyperforin-trimethoxybenzoate) showed antidepressant-like properties in the forced swimming test (FST) in rats, with no effect on open-field activity, when given as three intraperitoneal injections in 24 h at 3.

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Rationale: Hyperforin has been identified as an active constituent of Hypericum perforatum but its importance in the antidepressant effect of this plant's extracts is not really known.

Objective: To evaluate the antidepressant-like activity of two extracts in relation to the content of hyperforin and its plasma and whole brain concentrations, compared with a stable salt of hyperforin (dicyclohexylammonium; DCHA).

Methods: The effects of the extracts and hyperforin were evaluated in the rat forced swimming test.

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The causes and mechanisms underlying multidrug resistance (MDR) in epilepsy are still elusive and may depend on inadequate drug concentration in crucial brain areas. We studied whether limbic seizures or anticonvulsant drug treatments in rodents enhance the brain expression of the MDR gene (mdr) encoding a permeability glycoprotein (P-gp) involved in MDR to various cancer chemotherapeutic agents. We also investigated whether changes in P-gp levels affect anticonvulsant drug concentrations in the brain.

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The multiple-dose pharmacokinetics and safety of a new potential antidementia compound, CL 275,838, were examined in two randomized, double-blind, parallel-group, placebo-controlled studies. The Alzheimer Disease Assessment Scale (ADAS) was employed to preliminarily assess the patients' cognitive and the behavioral profiles. In the first study, nine patients with Alzheimer type or vascular dementia were treated for 2 weeks with daily doses of 50 mg.

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