New diketopiperazines as vectors for peptide protection and brain delivery: Synthesis and biological evaluation.

New strategies allowing the transfer of molecules, especially peptides, through the blood-brain barriers are a major pharmacological challenge for the treatment of brain diseases. The present study aims at evaluating in vivo the cerebral bioavailability of carrier systems, based on small and functionalizable 2,5-diketopiperazine (DKP) motifs. We studied 2 different cyclo(Lys-Lys) DKP scaffolds alone and a cyclo(Lys-Gly) DKP carrier bearing as peptide model, the tau protein hexapeptide VQIVYK sequence. The different carrier systems were synthesized and radiolabeled using one of the free domains. The stability, biodistribution, and ability to cross blood-brain barrier were investigated in vivo in mice for 99m Tc-DKP scaffolds, 99m Tc-HVQIVYK peptide alone, and 99m Tc-DKP-VQIVYK. 125 I-labelled bovine serum albumin was used as negative control for brain uptake. Both radiolabeled DKPs scaffolds and 99m Tc-DKP-VQIVYK showed a high stability, while peptide 99m Tc-HVQIVYK alone was quickly degraded in vivo. The presence of 99m Tc-DKPs scaffolds and 99m Tc-DKP-VQIVYK was observed in the ventricular and subarachnoid spaces and to a lower extent in the brain parenchyma up to 45 minutes post-injection in mice. This work highlights the potentiality of DKP scaffolds as vectors to transport peptides into the brain by limiting proteolysis and favoring cerebral bioavailability.

'Clickable' 2,5-diketopiperazines as scaffolds for ligation of biomolecules: their use in Aß inhibitor assembly.

The synthesis of 1,3,6-trisubstituted-2,5-diketopiperazine scaffolds bearing up to three 'clickable' sites for further oxime bond or alkyne-azide cycloaddition ligations is described. The orthogonally Boc/Alloc protected DKP precursors prepared from L-lysine residues and an aminohexyl arm are efficiently prepared on a gram scale by sequentially using Fukuyama-Mitsunobu alkylation, dipeptide coupling and diketopiperazine ring formation as key steps. These scaffolds, with their glyoxylyl, aminooxy, alkynyl or azido functions, are "ready-to-use" platforms for biomolecular assembly. Their potentiality in this field was proved through the chemoselective ligation of Aß-binding motifs, the KLVFFA peptide and the curcumin molecule. The inhibitory effect of these conjugates on Aß amyloid fibril formation is reported using thioflavin T fluorescence assays and AFM observation.

Effects of cognitive-behavioural therapy on health-related quality of life in obese subjects with and without binge eating disorder.

OBJECTIVE: To measure the effects of cognitive-behavioural therapy on health-related quality of life (HRQL) in obese patients, in relation to binge eating disorder. DESIGN: Longitudinal, clinical intervention study consisting of structured sessions of cognitive-behavioural therapy, preceded by sessions chaired by a psychologist in subjects with binge eating. SUBJECTS: Two groups of obese patients (92 treated by cognitive-behavioural therapy (77 females); 76 untreated controls (67 female), selected from the waiting list (control group)). Of 92 treated patients, 46 had a binge eating disorder at psychometric testing and structured clinical interview. MEASUREMENTS: Health-related quality of life by means of Short-Form 36 questionnaire at baseline and after 3-5 months. RESULTS: Cognitive-behavioural treatment produced an average weight loss of 9.4+/-7.5 kg, corresponding to a BMI reduction of 3.48+/-2.70 kg/m(2). No changes were observed in the control group. All scales of HRQL improved in treated subjects (by 5-19%). In obese subjects with binge eating weight loss was lower in comparison to non-bingers (7.7+/-8.1 vs 11.1+/-6.6; P=0.034). However, the improvement in HRQL was on average larger, and significantly so for Role Limitation-Physical (P=0.006), Role Limitation-Emotional (P=0.002), Vitality (P=0.003), Mental Health (P=0.032) and Social Functioning (P=0.034). Bodily Pain was the sole scale whose changes paralleled changes in body weight. CONCLUSIONS: The positive effects of cognitive-behavioural therapy, mainly in subjects with binge eating, largely outweigh the effects on body weight, resulting in a significant change in self-perceived health status.

A FTIR spectroscopy evidence of the interactions between wheat germ agglutinin and N-acetylglucosamine residues.

Wheat germ agglutinin (WGA), a lectin binding a N-acetyl-D-neuraminic acid (NeuNAc) and/or N-acetyl-D-glucosamine (GlcNAc) group, was studied by Fourier transform infrared (FTIR) spectroscopy. Deconvolution of the FTIR spectrum of WGA alone indicated the presence of few alpha-helices and beta-sheets, in contrast to many other lectins. These results agree with previous WGA crystal data. The WGA conformational changes, induced by GlcNAc-bearing liposomes or GlcNAc oligomers, were studied by infrared differential spectroscopy. The GlcNAc binding to WGA resulted in a decrease of turns and alpha-helices and a concomitant appearance of beta-sheets, inducing more or less peptidic N-H deuteration.

Extensive atrazine pollution of drinking water in the Lombardia region and related public health aspects.

Introduced in 1957, atrazine is a herbicide used worldwide, mainly in corn cultivation areas for weed control. It is only slightly volatile, is highly soluble in water, and is moderately persistent in topsoil, where it is strongly absorbed to organic carbon. Because of these properties, atrazine can leach to ground water and persist for a long time. This work presents the results obtained so far from an investigation initiated because of an emergency situation in the Lombardia Region of Italy caused by the occurrence of levels of atrazine in drinking water exceeding those established by the European Economic Community and Italian regulations. Water samples from almost 3000 wells were analyzed in different laboratories of the Lombardia Region. Atrazine contamination occurred in a significant number of the wells examined. Examination of the analytical data overall leads to the conclusion that the agricultural use of atrazine in the Lombardia Region is a serious source of ground water contamination. In some areas other factors may be responsible for the contamination of ground water (for instance, industrial activities and/or uncontrolled waste discharges). Geological and hydrological characteristics may play an important role in ground water contamination. Purification systems containing active charcoal seem to be highly efficient in removing atrazine from contaminated water.