Keratoacanthoma: two cases with intravascular spread

We report two patients with keratoacanthoma, simple in one and multiple in the other, displaying typical histological features except for intravascular spread. Although this spread points to malignancy, it did not allow to rule out the diagnosis of keratoacanthoma. These aggressive histological features, as well as perineural invasion, are not linked to malignant clinical course, according to the literature. Intravascular spread suggests that keratoancanthoma could be considered as a peculiar form of well differentiated squamous cell carcinoma. Comparison between clinical and pathological observations should lead to more specific diagnosis.     

Perceived functions predict intensity of use and problems in young polysubstance users

Aims To model consumption patterns and problems associated with alcohol, cannabis, ecstasy, amphetamine and cocaine hydrochloride use in a non‐treatment sample of young polysubstance users. Design A cross‐sectional survey of 364 16–22‐year‐old (56.3% male) polysubstance users recruited and interviewed by peer interviewers. Measurements Structured questionnaires were used to gather identical datasets on the five target psychoactive substances, recording patterns of substance use; adverse consequences from use; negative effects; functions for substance use; and perceived peer use. Findings Functions for substance use strongly predicted intensity of use in all five substances when peer use, age of first use and demographics were controlled, explaining an additional 11–19% of the variance in scores. Functions also explained an average of 22% of the variance in problem scores over and above the effects of background variables and current intensity of use. In particular, functions concerned with relief from negative mood states were strong predictors of problem scores in alcohol, cannabis and cocaine. Conclusions The potential implications of using a functional approach to explaining and responding to substance use are considerable. This could help to enhance our understanding of how experimental substance use becomes regular and how regular use becomes problematic, and could thus inform prevention, education and intervention efforts.     

A systematic and critical review of the process of translation and adaptation of generic health-related quality of life measures in Africa,Asia, Eastern Europe,the Middle East,South America

In recent years there has been a worldwide increase in demand for subjective measures of health-related quality of life (HRQL). Researchers have the choice of whether to develop a new measure or whether to adapt an existing measure in another language. This review evaluates the processes used in translating and adapting nine generic HRQL instruments (15D, Dartmouth COOP/WONCA Charts, EuroQol, HUI, NHP, SIP, SF-36, QWB, WHOQOL) for use in Africa, Asia, Eastern Europe, the Middle East, and South America. The review adopts a universalist model of equivalence, outlined by Herdman, Fox-Rushby, and Badia (Qual. Life Res. 7 (1998) 323), to judge the 58 papers reviewed. Research spans 23 countries and is dominated by research in the East Asia and Pacific region and the SF-36. Results are reported for conceptual, item, semantic, operational, measurement and functional equivalence. It is argued that currently there is a misguided pre-occupation with scales rather than the concepts being scaled and too much reliance on unsubstantiated claims of conceptual equivalence. However, researchers using the WHOQOL approach are more likely to establish reliable conclusions concerning the equivalence of their instrument across countries. It is a key conclusion of this review that research practice and translation guidelines still need to change to facilitate more effective and less biased assessments of equivalence of HRQL measures across countries.     

The relationship between test methodology and elastic behavior of composites

Comparisons were made of the Young's moduli obtained with tests that impose static, low-frequency, or high-frequency elastic deformations on dental composite systems. The frequency of the imposed stress was reflected in the absolute value of Young's modulus. However, the values obtained at different test frequencies could be compared and understood by taking into account this frequency dependence. It was thus found that the composite structure largely determined the type of reaction to the imposed stress. The fundamental period test permitted the greatest differentiation in the elastic behavior of the investigated composites.