Sibling interaction of children with autism: development over 12 months

While deficits in social interaction are central to autism, the sibling relationship has been found to provide a key medium for the development of such skills. Naturalistic observations of sibling pairs including children with autism and controls with Down syndrome were made across two time periods, twelve months apart. Consistent with the evidence on typically developing children, the amount and rate of initiations of both prosocial and agonistic interaction increased, but further analysis suggested that these interactions were stage-managed by the typically developing children. Results show social interaction and imitation in children with autism and the special role that sibling interactions can play. Longitudinal research on the acquisition of social skills in children with developmental disabilities is needed.

Interaction of anthocyanins with human serum albumin: influence of pH and chemical structure on binding

The affinity of anthocyanins for human serum albumin (HSA) was determined by a fluorescence quenching method. The effects of pH and structure of anthocyanins on the binding constants were studied. The constants for binding of anthocyanins to HSA ranged from 1.08 x 10^5 M-1 to 13.16 x 10^5 M-1. A hydrophobic effect at acidic pH was shown by the relatively high positive entropy values under the conditions studied. Electrostatic interactions including hydrogen bonding contributed to the binding at pH 7.4. The effect of structure of anthocyanins on the affinity was pH dependent, particularly the effect of additional hydroxyl substituents. Hydroxyl substituents and glycosylation of anthocyanins decreased the affinity for binding to HSA at lower pH (especially pH 4), but increased the strength of binding at pH 7.4. In contrast, methylation of a hydroxyl group enhanced the binding at acidic pH, while this substitution reduced the strength of binding at pH 7.4. This paper has shown that changes in anthocyanin structure or reductions in pH, which may occur in the region of inflammatory sites, have an effect of the binding of anthocyanins to HSA.

Interaction of strangelets with ordinary nuclei

Strangelets (hypothetical stable lumps of strange quarkmatter) of astrophysical origin may be ultimately detected in specific cosmic ray experiments. The initial mass distribution resulting from the possible astrophysical production sites would be subject to reprocessing in the interstellar medium and in the earth`s atmosphere. In order to get a better understanding of the claims for the detection of this still hypothetic state of hadronic matter, we present a study of strangelet-nucleus interactions including several physical processes of interest (abrasion, fusion, fission, excitation and de-excitation of the strangelets), to address the fate of the baryon number along the strangelet path. It is shown that, although fusion may be important for low-energy strangelets in the interstellar medium (thus increasing the initial baryon number A), in the earth`s atmosphere the loss of the baryon number should be the dominant process. The consequences of these findings are briefly addressed.

Influence of Seasonality on the Interaction of Mercury with Aquatic Humic Substances Extracted from the Middle Negro River Basin (Amazon)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural Basis for Interaction of Inhibitors with Cyclin-Dependent Kinase 2

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spectroscopic study of the interaction of Nd3+ with amino acids: Phenomenological 4f-4f intensity parameters

We have studied the bevahior of the phenomenological 4f-4f intensity parameters in compounds of the Nd ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame™ in aqueous solution, as a function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant.

Sugarcane trash management assessed by the interaction of yield with soil properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interaction of Curcumin with Manganese May Compromise Metal and Neurotransmitter Homeostasis in the Hippocampus of Young Mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Open circuit interaction of borohydride with oxidized platinum surfaces

An interesting method to investigate the effect of fuel crossover in low temperature fuel cells consists of studying the open circuit interaction between the reducing fuel and an oxide-covered catalyst. Herein we report the experimental study of the open circuit interaction between borohydride and oxidized platinum surfaces in alkaline media. When compared to the case of hydrogen and other small organic molecules, two remarkable new features were observed. Firstly, the interaction with borohydride resulted in a very-fast reduction process with transient times about two to three orders of magnitude smaller. The second peculiarity was that the decrease of the open circuit potential was found to occur in two-stages and this, previously unseen, feature was correlated with the two-hump profile found in the backward sweep in the cyclic voltammogram The consequences of our findings are discussed in connection with fundamental and applied aspects. (C) 2011 Elsevier B.V All rights reserved.

Interaction of gramicidin with DPPC/DODAB bilayer fragments

The interaction between the antimicrobial peptide gramicidin (Gr) and dipalmitoylphosphatidylcholine (DPPC)/dioctadecyldimethylammonium bromide (DODAB) 1:1 large unilamellar vesicles (LVs) or bilayer fragments (BFs) was evaluated by means of several techniques. The major methods were: 1) Gr intrinsic fluorescence and circular dichroism (CD) spectroscopy; 2) dynamic light scattering for sizing and zeta-potential analysis; 3) determination of the bilayer phase transition from extrinsic fluorescence of bilayer probes; 4) pictures of the dispersions for evaluation of coloidal stability over a range of time and NaCl concentration. For Gr in LVs, the Gr dimeric channel conformation is suggested from: 1) CD and intrinsic fluorescence spectra similar to those in trifluoroethanol (TFE); 2) KCl or glucose permeation through the LVs/Gr bilayer. For Gr in BFs, the intertwined dimeric, non-channel Gr conformation is evidenced by CD and intrinsic fluorescence spectra similar to those in ethanol. Both LVs and BFs shield Gr tryptophans against quenching by acrylamide but the Stern-Volmer quenching constant was slightly higher for Gr in BFs confirming that the peptide is more exposed to the water phase in BFs than in LVs. The DPPC/DODAB/Gr supramolecular assemblies may predict the behavior of other antimicrobial peptides in assemblies with lipids. (C) 2012 Elsevier B.V. All rights reserved.

Interaction of miltefosine with intercellular membranes of stratum corneum and biomimetic lipid vesicles

Miltefosine (MT) is an alkylphospholipid approved for breast cancer metastasis and visceral leishmaniasis treatments, although the respective action mechanisms at the molecular level remain poorly understood. In this work, the interaction of miltefosine with the lipid component of stratum corneum (SC), the uppermost skin layer, was studied by electron paramagnetic resonance (EPR) spectroscopy of several fatty acid spin-labels. In addition, the effect of miltefosine on (i) spherical lipid vesicles of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and (ii) lipids extracted from SC was also investigated, by EPR and time-resolved polarized fluorescence methods. In SC of neonatal Wistar rats, 4% (w/w) miltefosine give rise to a large increase of the fluidity of the intercellular membranes, in the temperature range from 6 to about 50 degrees C. This effect becomes negligible at temperatures higher that ca. 60 degrees C. In large unilamelar vesicles of DPPC no significant changes could be observed with a miltefosine concentration 25% molar, in close analogy with the behavior of biomimetic vesicles prepared with bovine brain ceramide, behenic acid and cholesterol. In these last samples, a 25 mol% molar concentration of miltefosine produced only a modest decrease in the bilayer fluidity. Although miltefosine is not a feasible skin permeation enhancer due to its toxicity, the information provided in this work could be of utility in the development of a MT topical treatment of cutaneous leishmaniasis. Published by Elsevier B.V.

Pharmacological interaction of drugs with immune receptors: the p-i concept

Drug-induced hypersensitivity reactions have been explained by the hapten concept, according to which a small chemical compound is too small to be recognized by the immune system. Only after covalently binding to an endogenous protein the immune system reacts to this so called hapten-carrier complex, as the larger molecule (protein) is modified, and thus immunogenic for B and T cells. Consequently, a B and T cell immune response might develop to the drug with very heterogeneous clinical manifestations. In recent years, however, evidence has become stronger that not all drugs need to bind covalently to the MHC-peptide complex in order to trigger an immune response. Rather, some drugs may bind directly and reversibly to immune receptors like the major histocompatibility complex (MHC) or the T cell receptor (TCR), thereby stimulating the cells similar to a pharmacological activation of other receptors. This concept has been termed pharmacological interaction with immune receptors the (p-i) concept. While the exact mechanism is still a matter of debate, non-covalent drug presentation clearly leads to the activation of drug-specific T cells as documented for various drugs (lidocaine, sulfamethoxazole (SMX), lamotrigine, carbamazepine, p-phenylendiamine, etc.). In some patients with drug hypersensitivity, such a response may occur within hours even upon the first exposure to the drug. Thus, the reaction to the drug may not be due to a classical, primary response, but rather be mediated by stimulating existing, pre-activated, peptide-specific T cells that are cross specific for the drug. In this way, certain drugs may circumvent the checkpoints for immune activation imposed by the classical antigen processing and presentation mechanisms, which may help to explain the peculiar nature of many drug hypersensitivity reactions.