RESUMO
The analysis of patterns of X-chromosome inactivation is becoming increasingly utilized as a marker of clonal composition of tissues from women. To date, however, no analogous system has been found for the study of clonality in tissue from men. In the current study, the methylation patterns for portions of the amelogenin genes are tested, which are encoded on both the X- and Y-chromosome (AMGX and AMGY). The polymerase chain reaction (PCR) was used to amplify portions of AMGX and AMGY from genomic DNA of carcinomas of the colon, lung, liver and kidney, as well as from matched normal somatic tissues. The amplification target included Alu I methylation sensitive restriction endonuclease sites as well as a 189 bp sequence which is present in AMGX but is absent in AMGY. Polymerase chain reaction amplification of AMGX and AMGY was successful using genomic DNA from both tumour and normal control tissue in 24 of the 26 cases. Pretreatment of genomic DNA with Alu I blocked amplification of AMGX in all cases from both normal tissue and tumour. This indicates that AMGX and AMGY undergo a non-random pattern of methylation in both normal tissues and in tumours, precluding their use as a marker of clonality. Methylation of Alu I sites in AMGY suggests that the amelogenin genes undergo dosage compensation, which raises the possibility that the expression of amelogenin is not restricted to the development of the tooth bud but may also play some other role in various tissues of the body.
Assuntos
Neoplasias do Colo/genética , Proteínas do Esmalte Dentário/genética , Mecanismo Genético de Compensação de Dose , Neoplasias Renais/genética , Neoplasias Hepáticas/genética , Neoplasias Pulmonares/genética , Adenocarcinoma/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Amelogenina , Biomarcadores , Carcinoma Hepatocelular/genética , Carcinoma de Células Renais/genética , Carcinoma de Células Pequenas/genética , Células Clonais/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores SexuaisRESUMO
After undergoing high-dose chemotherapy and autologous bone marrow transplantation, a patient developed fatal disseminated infection due to varicella-zoster virus (VZV) with no coincident skin lesions. This article describes this unusual case and briefly reviews the English-language literature on the abdominal presentation of VZV infection as well as that on VZV infection after bone marrow transplantation. In the severely immunocompromised host, visceral infection with VZV may uncommonly occur in the absence of skin lesions. The possibility of such infection should be considered when immunocompromised patients develop unusual symptoms or other evidence of visceral disease (e.g., cholecystitis).