102,819 research outputs found
Clinical manifestations of Deletion 22q11.2 syndrome (DiGeorge/Velo-CardioFacial syndrome)
No full textDeletion 22q11.2 syndrome (Del22) (DiGeorge/Velo-Cardio-Facial syndrome) is
characterized by congenital heart defect (CHD), palatal anomalies, facial
dysmorphisms, neonatal hypocalcemia, immune deficit, speech and learning
disabilities. CHD is present in 75% of patients with Del22. The most frequently seen
cardiac malformations are “conotruncal” defects, including tetralogy of Fallot (TF),
pulmonary atresia with ventricular septal defect (PA-VSD), truncus arteriosus (TA),
interrupted aortic arch (IAA), and ventricular septal defect (VSD). The study of the
specific “cardiac phenotype” in patients with Del22 shows that a particular cardiac
anatomy can be identied in these subjects. In addition to CHD, various organ
systems can be involved, so that a multidisciplinary approach is needed in the
evaluation of patients with Del22.peer-reviewe
Solid-State Strategy for the S-Conjugation of Peptides Catalyzed by Zeolites and Promoted by Microwave Radiation: A Green Approach
No full textA green synthetic protocol to add a chemical function to a fully deprotected peptide to obtain a bioactive and/or fluorescent-labeled conjugate is reported. A range of S-conjugation reactions promoted by the commercially available LTA zeolite to introduce different substituents on peptide cysteine residues has been shown to take place in the solid state or in the presence of minimal amounts of organic solvent, with yields that are comparable to those of standard solution methods. The additional advantage of the procedure consists of easing the work up, for which green solvents, such as aqueous systems, can be employed. The protocol is implemented with microwave irradiation to shorten the reaction time as dielectric heating increases the diffusion rates of the mechanically milled reactants
Modulation of the antioxidant activity of HO scavengers by albumin binding: a 19F-NMR study
No full textThe interaction between different HOradical dot radical scavengers in a three-component antioxidant system has been investigated by means of 19F-NMR spectroscopy. This system is composed of bovine serum albumin (BSA), trolox, and N-(4-hydroxyphenyl)-trifluoroacetamide (CF3PAF). The antioxidant capacity of BSA and trolox has been assessed by measuring the amount of trifluoroacetamide (TFAM) arising from the radical mediated decomposition of CF3PAF. When assayed separately, both trolox and BSA behaved as antioxidants, as they were effective to protect CF3PAF from HOradical dot radical-mediated decomposition. By contrast, trolox enhanced the production of TFAM in the presence of BSA, thus behaving as a pro-oxidant. Urate, carnosine, glucose, and propylgallate showed antioxidant properties both with or without BSA. CF3PAF and trolox were found to bind to BSA with association constants in the order of 5 × 103 M−1 and to compete for the same binding sites. These results have been discussed in terms of BSA-catalysed cross-reactions between trolox-derived secondary radicals and CF3PAF.The interaction between different HO. radical scavengers in a three-component antioxidant system has been investigated by means of 19F-NMR spectroscopy. This system is composed of bovine serum albumin (BSA), trolox, and N-(4-hydroxyphenyl)-trifluoroacetamide (CF3PAF). The antioxidant capacity of BSA and trolox has been assessed by measuring the amount of trifluoroacetamide (TFAM) arising from the radical mediated decomposition of CF3PAF. When assayed separately, both trolox and BSA behaved as antioxidants, as they were effective to protect CF3PAF from HO. radical-mediated decomposition. By contrast, trolox enhanced the production of TFAM in the presence of BSA, thus behaving as a pro-oxidant. Urate, carnosine, glucose, and propylgallate showed antioxidant properties both with or without BSA. CF3PAF and trolox were found to bind to BSA with association constants in the order of 5×103M-1 and to compete for the same binding sites. These results have been discussed in terms of BSA-catalysed cross-reactions between trolox-derived secondary radicals and CF3PAF. © 2003 Elsevier Inc. All rights reserved
Bonemarrow transplantation and thymopoietin pentapeptide treatment in two infantswith immunodeficiency with predominant T-cell defects
No full textA cyclic CCK8 analogue selective for the cholecystokinin type A receptor: Design, synthesis, NMR structure and binding measurements
No full textA cyclic CCK8 analogue, cyclo29,34[Dpr29,Lys34]-CCK8 (DprL-2,3-diaminopropionic acid), has been designed on the basis of the NMR structure of the bimolecular complex between the N-terminal
fragment of the CCKA receptor and itsnatural ligand CCK8. The conformational featuresof cyclo29,34[Dpr29,Lys34]-CCK8 have been determined by NMR spectroscopy in aqueous solution and in water
containing DPC-d38 micelles(DPC dodecylphosphocholine). The structure of the cyclic peptide in aqueous solution is found to be in a relaxed conformation, with the backbone and Dpr29 side chain
atomsmakin g a planar ring and the N-terminal tripeptide extending approximately along the plane of thisring. In DPC/water, the cyclic peptide adoptsa TMboat-shaped∫ conformation, which ismore compact than that found in aqueouss olution. The cyclic constraint between the Dpr29 side chain and the CCK8 carboxyl terminus (Lys34) introduces a restriction in the backbone conformational freedom. However, the interaction of cyclo29,34-[Dpr29,Lys34]-CCK8 with the micelless till playsan important role in the stabilisation of the bioactive conformation. A careful comparison of the NMR structure of the cyclic peptide in a DPC micelle aqueous solution with the structure of the rationally designed model underlinesthat the turn-like conformation in the Trp30 - Met31 region is preserved, such that the Trp30 and Met31 side chains can adopt the proper spatial orientation to interact with the CCKA receptor. The binding propertiesof cyclo29,34[Dpr29,Lys34]-CCK8 to the N-terminal receptor fragment have been investigated by fluorescence spectroscopy in a micellar environment. Estimates of the apparent dissociation constant, Kd, were in the range of 70-150 nM, with a mean value of 120±27 nM. Preliminary nuclear medicine studies on cell lines transfected with the CCKA receptor indicate that the sulfated-Tyr derivative of cyclo29,34[Dpr29,Lys34]-CCK8 displaces the natural ligand with an IC50 value of 15 microM
Disturbo Pervasivo dello Sviluppo - Non altrimenti Specificato: Percorsi Possibili e Prospettive per il Futuro
No full textI Disturbi Pervasivi dello Sviluppo di tipo Non Altrimenti Specificato (DPS-NAS) rappresentano una categoria diagnostica in cui i sintomi, costituiti da deficit nell’area dell’interazione sociale e da disturbi nell’area della comunicazione e degli interessi, non raggiungono, per gravità o quantità, quelli che sono i criteri stabiliti per la diagnosi di autismo o di altri DPS. I sintomi presentati da questi pazienti sono definiti “sottosoglia”: possono essere non sufficienti sia dal punto di vista qualitativo (la sintomatologia appare più lieve), che dal punto di vista quantitativo (non si raggiunge un numero adeguato di sintomi per fare diagnosi di autismo o di altro DPS). Data l’aspecificità del quadro sintomatologico e quindi la mancanza di precisi criteri diagnostici, lo scopo del presente lavoro è quello di scattare un’istantanea delle caratteristiche cliniche di un campione di bambini con diagnosi di DPS-NAS. Dall’analisi dei risultati è emerso come sia chiara la difficoltà di categorizzare rigidamente un disturbo dai confini non ben distinti, eterogeneo nelle sue manifestazioni cliniche ma che al tempo stesso sembra mostrare, al suo interno, la presenza di caratteristiche comuni ben delineate, quali l'insorgenza precoce dei sintomi e la presenza di deficit nell’interazione sociale. Con la nuova classificazione prevista nel DSM-5 e la comparsa della nuova categoria diagnostica denominata “Social Communication Disorder”, si tracceranno nuovi confini nosografici, con il tentativo di fornire punti di riferimento più stabili e chiari per la progettazione di interventi terapeutici mirati.Pervasive Developmental Disorders Not Otherwise Specified (PDD-NOS) represents a diagnostic category in which the symptoms, comprising impairments in social interaction,communication and interest areas,do not reach,in quantity or seriousness,the established criteria for autism or another specific PDD.The symptomatology displayed by these patients can be defined as “subthreshold”: the symptoms can be insufficient not only on a quality level (the symptomatology appears less serious), but also quantitatively (the number of symptoms does not allow to diagnose autism or another specific PDD).Due to the lack of specificity of the symptom profile and therefore of precise diagnostic criteria, the objective of this paper has been to give a picture of the clinical features of a sample of children with PDD-NOS diagnosis.Results show the complexity of categorising rigidly a disorder with non-specific borders. With DSM-5 new nosographic borders will be traced
Microwave heating promotes the S-alkylation of aziridine catalyzed by molecular sieves: A post-synthetic approach to lanthionine-containing peptides
No full textAziridine derivatives involved in nucleophilic ring-opening reactions have attracted great interest, since they allow the preparation of biologically active molecules. A chemoselective and mild procedure to convert a peptide cysteine residue into lanthionine via S-alkylation on aziridine substrates is presented in this paper. The procedure relies on a post-synthetic protocol promoted by molecular sieves to prepare lanthionine-containing peptides and is assisted by microwave irradiation. In addition, it represents a valuable alternative to the stepwise approach, in which the lanthionine precursor is incorporated into peptides as a building block
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