TNF-alpha promoter gene polymorphisms in Spanish children with persistent oligoarticular and systemic-onset juvenile idiopathic arthritis.

Objective: To explore the possible association/s of the first reported tumour necrosis factor (TNF-alphaTNF-) alpha promoter gene polymorphisms -308, -238, -376 and -163 (G-->A) with systemic (SoJIA) and oligoarticular subtypes of juvenile idiopathic arthritis (JIA); and to test the association between these polymorphisms and the class I/class II HLA alleles in our population.

Methods: The patient group comprised 29 oligoarticular and 26 systemic Caucasian Spanish children with JIA; 68 healthy volunteers from the same ethnic group and geographical region served as controls. HLA alleles were determined using low-resolution polymerase chain reaction (PCR).

Telomerase activity and telomere length in primary and metastatic tumors from pediatric bone cancer patients.

The presence of telomerase activity has been analyzed in almost all tumor types and tumor-derived cell lines. However, there are very few studies that focus on the presence of telomerase activity in bone tumors, and most of them report analysis on very few samples or bone-derived cell lines. The objective of this study was to analyze the telomere length and telomerase activity in primary tumors and metastatic lesions from pediatric osteosarcoma and Ewing's sarcoma patients.

Screening of the human tumor necrosis factor-alpha (TNF-alpha) gene promoter polymorphisms by PCR-DGGE analysis.

We have designed a new PCR-DGGE technique that enables detection of base changes in the TNF-alpha gene promoter. Screening of 130 samples from Spanish children has shown that this technique accurately detects the altered band patterns induced by the presence of the polymorphisms at positions -376, -308, -238 and -163 of the promoter sequence. Although further analysis are needed to fully characterise the alterations detected, we believe that this PCR-DGGE technique is a rapid and sensitive first approach to the genetic characterisation of the TNF-alpha promoter.

p21WAF1 mutation is not a predominant alteration in pediatric bone tumors.

The molecular events leading to the development of pediatric bone tumors are not clear to date, but abnormal cell cycle progression has been reported in a wide variety of human tumors due to the alteration of several tumor suppressor genes. We have analyzed 55 bone sarcoma samples from pediatric patients to test the possibility that they harbor mutations in the p21WAF1 tumor suppressor gene. Mutation analysis was performed through denaturing gradient gel electrophoresis analysis of exon 2 of the gene and consequent cycle sequencing of the altered fragments.