Image compression impact on quantitative angiogenesis analysis of ovarian epithelial neoplasms.

OBJECTIVE: This study aims to investigate the impact of digital image compression on manual and semiautomatic quantification of angiogenesis in ovarian epithelial neoplasms (including benign, borderline, and malignant specimens). DESIGN: We examined 405 digital images (obtained from a previously validated computer-assisted analysis system), which were equally divided into 5 groups: images captured in Tagged Image File Format (TIFF), low and high compression Joint Photographic Experts Group (JPEG) formats, and low and high compression JPEG images converted from the TIFF files. MEASUREMENTS: Microvessel density counts and CD34 endothelial areas manually and semiautomatically determined from TIFF images were compared with those from the other 4 groups. RESULTS: Mostly, the correlations between TIFF and JPEG images were very high (intraclass correlation coefficients >0.8), especially for low compression JPEG images obtained by capture, regardless of the variable considered. The only exception consisted in the use of high compression JPEG files for semiautomatic microvessel density counts, which resulted in intraclass correlation coefficients of <0.7. Nonetheless, even then, interconversion between TIFF and JPEG values could be successfully achieved using prediction models established by linear regression. CONCLUSION: Image compression does not seem to significantly compromise the accuracy of angiogenesis quantitation in the ovarian epithelial tumors, although low compression JPEG images should always be preferred over high compression ones.

[Use of psychotropics drugs among students: prevalence and associated social factors]. / Uso de drogas psicotrópicas por estudantes: prevalência e fatores sociais associados.

OBJECTIVE: To determine the prevalence of the heavy use of drugs among elementary and high school students in a sample of public and private schools, and to identify associated demographic, psychological, cultural and social factors. METHODS: This report describes a cross-sectional study using an intention-type sampling technique that compared public schools in central and peripheral areas and private schools. An anonymous self-administered questionnaire was applied. The sample consisted of 2,287 elementary and high school students in the city of Campinas in 1998. Heavy use of drugs was defined as the use of drugs on 20 or more days during the 30 days preceding the survey (WHO, 1981). For the statistical analysis, polytomic logistic regression analysis (logit model) was utilized to identify factors that influenced this manner of using drugs. RESULTS: Heavy use of legal and illegal drugs was found as follows: alcohol (11.9%), tobacco (11.7%), marijuana (4.4%), solvents (1.8%), cocaine (1.4%), medications (1.1%) and ecstasy (0.7%). The heavy use of drugs was greatest among students at the city-center public school who had daytime jobs and studied in the evenings. These students were in the A and B socioeconomic classes and had had little religious education during childhood. CONCLUSIONS: Greater availability of cash and specific socialization patterns were identified as factors associated with the heavy use of drugs among students.

Uso de drogas psicotrópicas por estudantes: prevalência e fatores sociais associados / Use of psychotropics drugs among students: prevalence and associated social factors

OBJETIVO: Determinar a prevalência do uso pesado de drogas por estudantes de primeiro e segundo graus em uma amostra de escolas públicas e particulares, e identificar fatores demográficos, psicológicos e socioculturais associados. MÉTODOS: Trata-se de um estudo transversal com uma técnica de amostragem do tipo intencional comparando-se escolas públicas de áreas periféricas e centrais e escolas particulares. Foi utilizado um questionário anônimo de autopreenchimento. A amostra foi constituída por 2.287 estudantes de primeiro e segundo graus da cidade de Campinas, SP, no ano de 1998. Considerou-se uso pesado, o uso de drogas em 20 dias ou mais nos 30 dias que antecederam a pesquisa. Para análise estatística, utilizou-se a análise de regressão logística politômica - modelo logito, visando identificar fatores que influenciem este modo de usar drogas. RESULTADOS: O uso pesado de drogas lícitas e ilícitas foi de: álcool (11,9 por cento), tabaco (11,7 por cento), maconha (4,4 por cento), solventes (1,8 por cento), cocaína (1,4 por cento), medicamentos (1,1 por cento), ecstasy (0,7 por cento). O uso pesado foi maior entre os estudantes da escola pública central, do período noturno, que trabalhavam, pertencentes aos níveis socioeconômicos A e B, e cuja educação religiosa na infância foi pouco intensa. CONCLUSÕES: Maior disponibilidade de dinheiro e padrões específicos de socialização foram identificados como fatores associados ao uso pesado de drogas em estudantes.