George Manolov

Small noncleaved B cell burkitt-like lymphoma with chromosome t(8;14) translocation and epstein-barr virus nuclear-associated antigen in a homosexual man with acquired immune deficiency syndrome

This case report describes new manifestations of the acquired immune deficiency syndrome (AIDS) in a promiscuous homosexual man. Investigation of upper gastrointestinal bleeding in the patient lead to discovery of a high-grade, small, noncleaved cell (Burkitt-like) gastroduodenal lymphoma with visceral and extralymphatic extension. Specific phenotyping of the lymphoma revealed that it was a monoclonal B cell lymphoma of mu kappa isotype. An in vitro cell line was established that was Epstein-Barr virus nuclear-associated antigen-positive. The lymphoma cells displayed a t(8;14) translocation similar to endemic African Burkitt lymphoma. Epstein-Barr virus genomes were identified in the lymphoma and an axillary lymph node biopsy specimen by molecular hybridization. These data strongly suggest that Epstein-Barr virus actively infected this patient. However, he showed normal Epstein-Barr virus-specific serologic responses, indicating an immune defect against the virus.

Alternative involvement of two cytogenetically distinguishable breakpoints on chromosome 8 in burkitt's lymphoma associated translocations

The chromosomes of 16 Burkitts lymphoma (BL) derived cell lines were submitted to high-resolution G-band analysis. They included seven lines with t(8;14), three with t(2;8), and four with t(8;22). The translocation breakpoint in chromosome #14 was located in 14q32.3, in chromosome #2 in 2p11.1, and in chromosome #22 in 22q12.12. In chromosome #8, the translocation breakpoint was located in two cytogenetically distinct subbands: 8q24.1 in cell lines with t(8;14) and t(2;8) and 8q24.22 in cell lines with t(8;22). In the light of recent molecular findings, these results indicate that the distance between the c-myc gene, located in 8q24, and the Ig sequences might be much larger in BL lines with t(8;22) than in those with t(2;8).

Satellite DNA in the three C-bands of an unusual mouse marker chromosome: A model of chromosomal evolution☆

A marker chromosome in the stemline of a new murine cell line is described on the basis of different stainings and in situ hybridization. The marker was characterized originally by three C-bands, one from each centromeric region of the three chromosomes constituting the marker. In the course of stemline evolution, two of the C-bands have been lost and the marker has developed into a monocentric chromosome, phenotypically and functionally normal.

Genetic Diseases, Hamartomas, and Familial Occurrence of Neoplasms

Most malignant neoplasms likely arise from the deleterious effects of environmental carcinogens. In addition, it appears that genetic predisposition or resistance governs responses of individuals to these agents. This interaction between environmental carcinogens and genetic factors has been termed ecogenetics. Ultimately, the final step in the genesis of malignant neoplasms involves molecular and/or cytogenetic alterations that free the cell from internal or external host regulatory control.