Melanosis intestini: case report

The term melanosis in the gastrointestinal tract refers to the accumulation of pigment deposits in the mucosa. Melanosis of the colon is not uncommon and has been associated with certain conditions, however melanosis of the small intestine is extremely rare. Herein, we describe a case in which we observed melanosis not only in the colon, but in the terminal ileum as well, associated with the use of anthraceneline laxatives. The clinical significance of this condition is not clear, however Gastroenterologists and Pathologists should be aware of its existence

Rare mutations predisposing to familial adenomatous polyposis in Greek FAP patients

BACKGROUND: Familial Adenomatous Polyposis (FAP) is caused by germline mutations in the APC (Adenomatous Polyposis Coli) gene. The vast majority of APC mutations are point mutations or small insertions / deletions which lead to truncated protein products. Splicing mutations or gross genomic rearrangements are less common inactivating events of the APC gene. METHODS: In the current study genomic DNA or RNA from ten unrelated FAP suspected patients was examined for germline mutations in the APC gene. Family history and phenotype were used in order to select the patients. Methods used for testing were dHPLC (denaturing High Performance Liquid Chromatography), sequencing, MLPA (Multiplex Ligation – dependent Probe Amplification), Karyotyping, FISH (Fluorescence In Situ Hybridization) and RT-PCR (Reverse Transcription – Polymerase Chain Reaction). RESULTS: A 250 Kbp deletion in the APC gene starting from intron 5 and extending beyond exon 15 was identified in one patient. A substitution of the +5 conserved nucleotide at the splice donor site of intron 9 in the APC gene was shown to produce frameshift and inefficient exon skipping in a second patient. Four frameshift mutations (1577insT, 1973delAG, 3180delAAAA, 3212delA) and a nonsense mutation (C1690T) were identified in the rest of the patients. CONCLUSION: Screening for APC mutations in FAP patients should include testing for splicing defects and gross genomic alterations

Telomerase Activity and Genetic Alterations in Primary Breast Carcinomas

It has been proposed that the structural and numerical chromosome abnormalities recorded in breast cancer could be the result of telomere dysfunction and that telomerase is activated de novo to provide a survival mechanism curtailing further chromosomal aberrations. However, recent in vivo and in vitro data show that the ectopic expression of telomerase promotes tumorigenesis via a telomere length-independent mechanism. In this study, the relation between telomerase expression and the extent of chromosomal aberrations was investigated in 62 primary breast carcinomas. Telomerase activity was measured using a polymerase chain reaction-based telomeric repeat amplification protocol assay and 92% of the tumors were found to express telomerase with a relative activity ranging from 0 to 3839.6. Genetic alterations were determined by G-banding and comparative genomic hybridization analysis and 97% of the tumors exhibited chromosomal aberrations ranging from 0 to 44 (average: 10.98). In the overall series, the relationship between telomerase activity levels and genetic changes could be best described by a quadratic model, whereas in tumors with below-average genetic alteration numbers, a significant positive association was recorded between the two variables (coefficient=0.374, P= .017). The relationship between telomerase activity levels and the extent of genetic alteration may reflect the complex effect of telomerase activation upon tumor progression in breast carcinomas