Stereotyped behaviours as precursors of self-injurious behaviours: a longitudinal study with infants and toddlers at risk for developmental delay

BACKGROUND

The notion that stereotypic behaviours may be precursors of self-injurious behaviour (SIB) has been considered in the past, but the available empirical evidence is still inconsistent and ambiguous.

METHOD

In a longitudinal study, we collected data on stereotypic behaviour and SIB from 160 infants and toddlers who were at-risk for developmental delay. Interviews were conducted with parents at three time points during a one-year span using the Behaviour Problems Inventory-01 which contains subscales for SIB and stereotyped behaviour. We used growth modelling to estimate linear trends in several models. Model fit was evaluated according to a combination of fit statistics as is recommended in structural equation or latent variable modelling approaches such as latent growth modelling.

RESULTS

In examining the relationship between stereotyped behaviours and SIB across time, the model that represented earlier stereotyped behaviour as predicting later SIB fit the data better than the other models.

CONCLUSIONS

The findings corroborate the notion that stereotyped behaviour can be a precursor of SIB. If replicated by other studies, it makes a case for considering early intervening with stereotyped behaviour as a SIB prevention strategy.

Functional properties of behaviour problems depending on level of intellectual disability

BACKGROUND

Behaviour problems are common among individuals with intellectual disabilities (ID) especially in those with more severe forms. The determination of the functional profile of a targeted behaviour has important implications for the design of customised behavioural interventions.

METHOD

We investigated the relationship between the level of ID and the functional profile of aggression, stereotypy and self-injurious behaviour (SIB) using the Questions about Behavioural Function (QABF). Two staff members at two time points completed the QABF for each of 115 adults with varying levels of ID participating in a day training and habilitation programme.

RESULTS AND CONCLUSIONS

Our results suggest that there is a differential relationship between the functions of behaviour problems and level of ID. While SIB is more often seen by raters to be maintained by escape of social demands and by attaining access to tangible items with the decline of the intellectual level, aggressive and stereotypic behaviours were identified more often as serving multiple functions equally across functioning level.

Pentoxifylline/Chitosan Films on Wound Healing: In Vitro/In Vivo Evaluation

This study aimed to develop films of chitosan (CSF) associated with pentoxifylline (PTX) for healing cutaneous wounds. These films were prepared at two concentrations, F1 (2.0 mg/mL) and F2 (4.0 mg/mL), and the interactions between the materials, structural characteristics, in vitro release, and morphometric aspects of skin wounds in vivo were evaluated. The formation of the CSF film with acetic acid modifies the polymeric structure, and the PTX demonstrates interaction with the CSF, in a semi-crystalline structure, for all concentrations. The release for all films was proportional to the concentration, with two phases: a fast one of ≤2 h and a slow one of >2 h, releasing 82.72 and 88.46% of the drug after 72 h, being governed by the Fickian diffusion mechanism. The wounds of the mice demonstrate a reduction of up to 60% in the area on day 2 for F2 when compared to CSF, F1, and positive control, and this characteristic of faster healing speed for F2 continues until the ninth day with wound reduction of 85%, 82%, and 90% for CSF, F1, and F2, respectively. Therefore, the combination of CSF and PTX is effective in their formation and incorporation, demonstrating that a higher concentration of PTX accelerates skin-wound reduction.

Effectiveness In Vivo and In Vitro of Polymeric Nanoparticles as a Drug Release System in the Treatment of Leishmaniasis

Leishmaniasis is a neglected disease caused by the parasite of the genus Leishmania. Current treatment regimens are obsolete and cause several side effects, promoting poor patient compliance, in addition to the vast majority already having the potential for resistance. Therefore, polymeric nanoparticles emerge as one of the viable alternatives to overcome existing limitations, through passive or active vectorization. This review aims to summarize the latest studies of polymeric nanoparticles as an alternative treatment for leishmaniasis. In the first section, the main pharmacokinetic and pharmacodynamic challenges of current drugs are reported. The second section details how nanoparticles with and without functionalization are efficient in the treatment of leishmaniasis, discussing the characteristics of the polymer in the formulation. In this way, polymeric nanoparticles can improve the physicochemical properties of leishmanicidal drugs, improving solubility and stability, as well as improve the release of these drugs, directly or indirectly reaching monocytes/macrophages. 64.28% drugs were focused on the treatment of visceral leishmaniasis, and 28.57% on cutaneous leishmaniasis. The most chosen polymers in the literature are chitosan (35.71%) and PLGA (35.71%), the others represented 14.30% drugs, with all able to manage the drug release and increase the in vitro and/or in vivo efficacy of the original molecule. However, there are several barriers for these nanoformulations to cross laboratory research and is necessary more in-depth studies about the metabolites and degradation pathways of the polymers used in the formulations and plasma proteomics studies.