Semantic loss without surface dyslexia

Abstract

Recent models of reading, including some computational models, suggest that error-free performance in reading aloud may be reliant, at least in part, on support from the semantic system. Such models predict that, following semantic impairment, a pattern of acquired dyslexia known as ‘surface dyslexia’ will be an inevitable consequence. We present data from a patient with dementia of Alzhelmer type who shows a severe semantic impairment but near error-free performance on reading aloud real words (including low-frequency, irregular, abstract words) and non-words. The data are discussed in light of various models of reading and in relation to previously reported cases.     

The Trichotillomania Impact Project in Young Children (TIP-YC): Clinical Characteristics,Comorbidity, Functional Impairment and Treatment Utilization

The aim was to investigate clinical characteristics of young children with a hair pulling problem. Parents/caregivers of young children (0–10 years old) with a hair pulling problem (N = 110) completed an online survey. The majority reported that their child experienced mild to moderate impairment/distress due to hair pulling, and overall clinical characteristics were similar to adult samples, although some differences were noted (e.g., less awareness of pulling). We also compared preschool-aged and school-aged children within the sample. Symptom severity, pleasure during pulling and gender ratio remained stable across the age groups. The preschool-aged children demonstrated less impairment/distress, comorbidity, and treatment seeking; pulled from fewer body areas; and were less likely to be aware of the act or experience tension prior to pulling. In conclusion, clinical characteristics of childhood hair pulling are largely similar to adult/adolescent hair pulling problems, but there are some notable differences, particularly among pre-school aged children.     

Effect of a one‐step self‐etch adhesive on endogenous dentin matrix metalloproteinases

Degradation of the hybrid layer created in dentin by dentin adhesives is caused by enzyme activities present within the dentin matrix that destroy unprotected collagen fibrils. The aim of the present study was to evaluate the effect of a one‐step self‐etch adhesive system on dentinal matrix metalloproteinases 2 and 4 (MMP‐2 and MMP‐9, respectively) using in situ zymography and an enzymatic activity assay. The null hypothesis tested was that there are no differences in the activities of dentinal MMPs before and after treatment with a one‐step adhesive system. The MMP‐2 and MMP‐9 activities in dentin treated with the one‐step adhesive, Adper Easy Bond, were quantified using an enzymatic activity assay system. The MMP activities within the hybrid layer created by the one‐step adhesive tested were also evaluated using in situ zymography. The enzymatic assay revealed an increase in MMP‐2 and MMP‐9 activities after treatment with adhesive. In situ zymography indicated that gelatinolytic activity is present within the hybrid layer created with the one‐step self‐etch adhesive. The host‐derived gelatinases were localized within the hybrid layer and remained active after the bonding procedure. It is concluded that the one‐step self‐etch adhesive investigated activates endogenous MMP‐2 and MMP‐9 with the dentin matrix, which may cause collagen degradation over time.