Stephen E. Bloom

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A simple ammoniacal silver staining procedure, designated Ag-AS, differentially stains the chromosomal locations of ribosomal DNA in certain mammalian species. This was critically demonstrated by Ag-AS staining of the nucleolus organizer regions in karyotypes of the same species and cell lines used for locating the ribosomal cistrons by DNA/RNA in situ(More)
A reliable technique for staining human chromosomal nucleolar organizers (NOR's) with silver solutions is described. The NOR's can be selectively stained dark brown by silver solutions leaving the chromosome arms unstained and available for counterstaining with orcein or Giemsa dyes. Unequivocal identification of chromosome pairs bearing NOR's can be(More)
Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken(More)
A decrease in chondrocyte numbers is one characteristic of osteoarthritic cartilage. This decrease may be the result of apoptosis or other forms of cell death induced by mechanical damage. Furthermore, cell death may contribute to the structural and metabolic changes found in osteoarthritic cartilage. Therefore, we investigated cell viability and the mode(More)
The linkage relationship and chromosomal locations of the major histocompatibility (B) complex and nucleolar organizers (18S + 28S ribosomal RNA genes) were studied in normal and aneuploid chickens. The Balloantigens were defined by hemagglutination, using monospecific alloantisera. A chicken having three B haplotypes was detected and used in test matings(More)
We investigated the expression of an apoptotic cell death program in blastodermal cells prior to gastrulation and the susceptibility of these cells to stress-induced cell death. A low frequency (3.1%) of apoptotic blastodermal cells was observed in Hoechst 33342-vitally stained cytological preparations of complete blastoderms from unincubated eggs. These(More)
Cytological screening of 4182 chick embryos from 10 strains and 5 strain crosses was performed to determine the types and frequencies of chromosome abnormalities. Gross phenotypic effects, such as growth retardation and malformation, were noted. Clues to the etiology of such chromosome aberrations were also sought. The following euploid series was observed:(More)
A panel of human B-lineage lymphoma cell lines differing in cancer drug-resistance status and Bcl-2/Bax expression were used to study the contribution of mitochondrial-based perturbations and regulation in differential induction of apoptosis. Mitochondrial dysfunction was induced in cells by the uncoupler carbonyl cyanide m-chlorophenylhydrazone (mClCCP)(More)
INUCLEATED cells occur in a variety of tissues in plants and animals normally and under varying physiological conditions (e.g., anemia, stress, ageing, regeneration, malignancy and viral infection) (BLOOM 1968). Among animals, naturally occurring binucleated cells have been observed in organisms of the following classes: Protozoa, Nematoda, Crustacea,(More)
Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important Gram-negative mucocutaneous bacterial pathogens. Irrespective of the bacterial species of origin, CDT causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. The active subunit(More)