Centromeric instability of chromosome 1 resulting in multibranched chromosomes, telomeric fusions, and "jumping translocations" of 1q in a human immunodeficiency virus-related non-Hodgkin's lymphoma.

BACKGROUND: Acquired immunodeficiency syndrome-related non-Hodgkin's lymphomas are associated with the B-cell chromosomal translocation t(8;14)(q24; q32). The most common secondary chromosome aberrations in these patients involve 1q and are believed to be associated with tumor progression. A mechanism for the origin of these 1q aberrations has not been demonstrated. To their knowledge, the authors report the first human immunodeficiency virus (HIV)-positive patient to have centromeric decondensation and multibranched chromosome aberrations of chromosomes 1 and 16 resulting in telomeric associations and "jumping translocations" of 1q. METHODS: Tumor cells from peritoneal fluid of an HIV-positive patient were cultured for 24, 48, and 72 hours and analyzed by both conventional G-banding and fluorescence in situ hybridization. RESULTS: G-band analysis showed a stemline with t(8;14)(q24;q32), but also showed the progression from centromeric decondensation to multibranched chromosome configurations of chromosomes 1 and 16. The interchange and duplications of chromosome arms resulted in the gain of extra copies of 1q material on a number of different chromosomes, but also the loss of 16q in at least one sideline and the formation of micronuclei. Fluorescence in situ hybridization analysis demonstrated that micronuclei predominantly involved chromosome 1 and, to a lesser extent, chromosome 16. CONCLUSIONS: The cytogenetic findings in this unique case suggest that immunodeficiency may be a factor involved in centromeric instability, multibranching, and the progression to the subsequent formation of telomeric fusions and multiple unbalanced translocations of 1q (jumping translocations). The striking similarity of the centromeric instability in this patient to those with ICF syndrome (variable immunodeficiency, centromeric heterochromatin instability, and facial anomalies) suggests hypomethylation as the etiologic mechanism for the chromosome instability.

Status of bovine tuberculosis in North America.

The eradication of bovine tuberculosis from North America is in the advanced stages as Canada and the United States struggle to remove the last vestiges of the disease from the domestic livestock population. Canada realistically anticipates total eradication from the national cattle herd within the next few years. The United States must yet effectively deal with the increased tuberculosis exposure potential from imported steers and from bovine tuberculosis newly discovered in its captive cervid industry. This paper reviews the history and development of tuberculosis eradication programs in North America. The basic evolution is described from area testing to slaughter surveillance with follow-up epidemiological investigations as the program foundation. The current status of both countries is described and recognized deterrents to final eradication are discussed.

Porcine rabies in a closed feeder barn.

Rabies was diagnosed in a 40 kg pig from a closed feeder barn in which recently unexplained deaths of eight to ten pigs had occurred. A stray cat, probably crawling through a ventilation duct into the barn, was the suspected vector. Over a four and one-quarter year period a disproportionate 53 cases of animal rabies had been diagnosed within a 5 km radius of the farm (13% of the cases in the county in 3% of the county area). Histological lesions, mostly lymphocytic cuffing of blood vessels in the brain with lymphocytic meningitis, patchy to focal gliosis and satellitosis with neuronal necrosis were nonspecific and Negri bodies were rare. Fluorescent antibody technique examination of the brain for rabies virus antigen was positive.