Identification of novel biomarkers with potential for diagnosis and prognosis of gastric cancer: a bioinformatics approach

INTRODUCTION: Gastric cancer (GC) is the fifth most diagnosed neoplasia and the third leading cause of cancer-related deaths. A substantial number of patients exhibit an advanced GC stage once diagnosed. Therefore, the search for biomarkers contributes to the improvement and development of therapies. OBJECTIVE: This study aimed to identify potential GC biomarkers making use of in silico tools. METHODS: Gastric tissue microarray data available in Gene Expression Omnibus and The Cancer Genome Atlas Program was extracted. We applied statistical tests in the search for differentially expressed genes between tumoral and non-tumoral adjacent tissue samples. The selected genes were submitted to an in-house tool for analyses of functional enrichment, survival rate, histological and molecular classifications, and clinical follow-up data. A decision tree analysis was performed to evaluate the predictive power of the potential biomarkers. RESULTS: In total, 39 differentially expressed genes were found, mostly involved in extracellular structure organization, extracellular matrix organization, and angiogenesis. The genes SLC7A8, LY6E, and SIDT2 showed potential as diagnostic biomarkers considering the differential expression results coupled with the high predictive power of the decision tree models. Moreover, GC samples showed lower SLC7A8 and SIDT2 expression, whereas LY6E was higher. SIDT2 demonstrated a potential prognostic role for the diffuse type of GC, given the higher patient survival rate for lower gene expression. CONCLUSION: Our study outlines novel biomarkers for GC that may have a key role in tumor progression. Nevertheless, complementary in vitro analyses are still needed to further support their potential.

Rules extraction from neural networks applied to the prediction and recognition of prokaryotic promoters

Promoters are DNA sequences located upstream of the gene region and play a central role in gene expression. Computational techniques show good accuracy in gene prediction but are less successful in predicting promoters, primarily because of the high number of false positives that reflect characteristics of the promoter sequences. Many machine learning methods have been used to address this issue. Neural Networks (NN) have been successfully used in this field because of their ability to recognize imprecise and incomplete patterns characteristic of promoter sequences. In this paper, NN was used to predict and recognize promoter sequences in two data sets: (i) one based on nucleotide sequence information and (ii) another based on stability sequence information. The accuracy was approximately 80 percent for simulation (i) and 68 percent for simulation (ii). In the rules extracted, biological consensus motifs were important parts of the NN learning process in both simulations.

Hematocérvix espontâneo em paciente pré-menopausada / Spontaneous hematocervix in a premenopausal women

Hematocérvix é uma coleção hemática localizada na cérvix uterina, geralmente associado à malformação uterina. A ocorrência em úteros anatomicamentes normais é uma rara condição ginecológica, estando descritos aproximadamente dez casos. Relatamos um novo caso de hematocérvix espontâneo em uma paciente de 47, pré-menopausada, sem historia de cauterizações cervicais, conização ou uso de terapia hormonal, que procurou atendimento de emergência por dor pélvica intensa e sangramento vaginal. Após exame físico e ecografia pélvica transvaginal foi feito o diagnóstico de hematocérvix.

Alfabetização, operatoriedade e nível de maturidade em crianças do ensino fundamental / Literacy, operativeness and level of maturity in primary school children

Este trabalho teve como objetivo discutir as possíveis relações estabelecidas entre as dificuldades de aprendizagem na escrita, o nível intelectual e maturacional de crianças de segunda série do ensino fundamental. Para tanto, utilizou-se a Escala de Avaliação na Aprendizagem da Escrita (ADAPE), bem como da prova de conservação de comprimento e do teste CAT-H. Os três testes foram aplicados em 60 crianças, de ambos os sexos, de duas escolas da rede pública de ensino. Os coeficientes de correlação por postos de Spearman sugerem que não houve correlações significantes entre os resultados relativos aos três testes e às idades dos sujeitos. Porém, pôde-se encontrar diferença significativa quando comparados os resultados do ADAPE com relação ao sexo feminino ou masculino, encontrando um melhor desempenho dos sujeitos do sexo feminino.

This paper aims to discuss the relationships established among the learning difficulties in writing and the intellectual and maturity level of the children attending at the second grade of primary school. The Escala de Avaliação na Aprendizagem da Escrita (ADAPE) as well as the length conservation task and the CAT-H were applied to 60 children, of both sexes, from two public schools. The Spearman’s rank correlation coefficients suggest that there were not any significant correlation among the data of the three tests and the subjects’ ages. It was possible, however, to find a significant difference when comparing the results of the ADAPE to the male and female sexes, the female subjects showing a better performance.