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Biomedical subjects

R C Briggs

Publications and source records attributed to R C Briggs.

At least 73 records · Page 4Linked to original sources
PubMed1981

Cross-linking of chromosomal non-histone proteins to DNA by UV radiation and some antitumor drugs.

Antibodies reacting specifically with HeLa cell chromatin can be elicited by immunization with dehistonized HeLa chromatin preparations. The nature of these chromatin-associated antigens was investigated by cross-linking with UV irradiation or by in vitro exposure of chromatin to 1-methyl-1-nitrosourea (MNU) or 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU). With the exception of 1-methyl-1-nitrosourea the described treatment of chromatin (native or dehistonized) significantly increased its immunological reactivity. Dissociation of the chromosomal proteins from DNA by concentrated salt-urea solutions essentially abolished the immunological reactivity of the residual chromatin pellets. The immunological activity was found in the supernatant protein fraction after its reconstitution with purified human placenta DNA. UV irradiation or alkylation of chromatin cross-linked the active proteins to DNA and prevented their dissociation. It is concluded that the immunologically cell-specific antigens in HeLa chromatin exist as closely associated complexes of chromosomal protein(s) with DNA.

Antigen-Antibody Complex↗
PubMed1981

Sequential liver-spleen scanning for documentation of wandering spleen.

An additional case of wandering spleen is reported. A brief review of the etiology of this entity, as well as various findings obtained with nuclear imaging of the spleen, is presented. The authors discuss the relevance of repeated spleen scans to the clinical decision making process. Particular significance is paid to preservation of the spleen to maintain immunologic competence.

Child, Preschool↗
PubMed1981

Lactoferrin: nuclear localization in the human neutrophilic granulocyte?

Conditions were established whereby nuclear or cytoplasmic immunocytochemical localization of lactoferrin was observed in the human peripheral blood granulocyte. A positive nuclear staining reaction was obtained when cells were either not fixed or treated with most fixatives. However, treatment of blood smears with formaldehydeacetone prior to the immunocytochemical localization gave a cytoplasmic staining reaction. A method was developed that allowed us to examine proteins obtained from granulocyte nuclei isolated from fixed cells. Only a trace amount of lactoferrin was detected in the electrophoretically separated nuclear proteins obtained from granulocytes treated for 1 min with formaldehyde-acetone. However, lactoferrin was major protein component in nuclei isolated from untreated cells, cells treated with other fixatives, or cells preincubated in buffered saline prior to formaldehyde-acetone fixation. formaldehyde-acetone treatment of nuclear materials containing lactoferrin did not extract lactoferrin or mask it from detection, thus indicating that lactoferrin found in the mature neutrophilic granulocyte nucleus is most likely acquired from other cellular organelles during tissue processing.

Cell Fractionation↗
PubMed1980

Immunologically specific complexes of chromosomal nonhistone proteins with deoxyribonucleic acid in chicken erythroid nuclei.

Erythroid cell-specific antisera capable of detecting chromosomal nonhistone protein-DNA complexes were obtained by injecting rabbits with dehistonized chicken reticulocyte chromatin. The specific antigenic nonhistone protein-DNA complexes were relatively inaccessible to the antiserum in isolated erythrocyte chromatin. However, isolation of chromatin from cells at earlier stages of erythropoiesis or treatment of isolated erythrocyte chromatin with polyanions or phenylhydrazine provided materials with significantly increased immunological reactivity. The altered activity was caused by changes in conformation occurring at two levels: a specific one, determined by chromosomal nonhistone proteins, and a more general one, determined by histones. Immunological examination of fractionated products obtained from limited nuclease digestion revealed the localization of the antigenic complexes in the nuclease-resistant, large fragments of erythroid chromatin. The nuclease-resistant DNA isolated from the immunologically reactive fragments migrated in gel electrophoresis as a diffuse band of between 1000 and 2000 base pairs. No preferential accumulation of globin-specifying DNA sequences could be found in this nuclease-resistant DNA. The protein fraction containing the immunologically cell-specific complexes in chicken erythrocyte chromatin was glycosylated and moderately acidic (by amino acid anaysis) with an electrophoretically determined Mr of approximately 90000.

Animals↗
PubMed1980

DNA-binding specificity of a chromatin non-histone protein fraction of HeLa cells.

The DNA-binding site of a previously characterized non-histone chromosomal protein antigen(s) from HeLa cells was investigated for its species specificity. Treatment with large amounts of micrococcal nuclease abolishes immunoactivity, which can then be recovered by the subsequent addition of human or HeLa DNA to reconstitute the immune complex. Neither rat nor calif DNA exhibits this property, but DNA from monkey cells gives considerable activity. The antigen is not, however, detectable in monkey chromatin.

Animals↗
PubMed1980

Human granulocyte-specific nuclear antigen(s). II. Detection of antigens in human proliferative syndromes.

Antisera raised to dehistonized chromatin from isolated normal human granulocytes revealed the presence of chromatin-associated antigens specific for the human neutrophils that appear during late stages of myeloid cellular differentiation. Immunological specificity was demonstrated by C fixation, immunodiffusion, and immunocytochemical reactions. Chromatin prepared from both normal granulocytes and specimens of myeloid leukemia showed immunologic reactivity. Although the normal antigens were detected in a specimen of CML, the position of immunodiffusion precipitin lines was different from that obtained with normal granulocyte chromatin. In addition, chromatin prepared from the myeloid leukemic cell line HL-60 expressed only one of the three precipitin bands normally found in immunodiffusion. The immunocytochemical staining reaction was confined to the nucleus of mature neutrophils in normal peripheral blood smears. Greater than 90% of cells in peripheral blood specimens of CML showed positive immunocytochemical nuclear staining. In other types of leukaemia, the normal mature granulocyte reacted with antiserum, but the nonmyeloid leukemic cells in these specimens did not. The specificity of immunologic reactions described here suggests the usefulness of nuclear antigens as cell markers.

Animals↗
PubMed1979

Cell-specific antigens in chicken erythroid nuclei: species specificity.

Antisera raised to dehistonized chicken reticulocyte chromatin were tested for their cell and species specificity. Quantitative microcomplement fixation and immunohistochemical localization revealed the presence in chromatin of erythroid cell-specific nonhistone protein antigen(s). The antigenic specificity was shown to depend on the association of the antigenic protein(s) with deoxyribonucleic acid (DNA). Although the antisera were exceptionally cell specific, they cross-reacted with erythroid cells of other avian species. The extent of cross-reactivity was found to approximate the phylogenetic distances of the tested avian species. Erythroid cells from fish and amphibians were not reactive. Reconstitution experiments of partially purified chicken reticulocyte chromosomal nonhistone protein antigens with DNAs isolated from several vertebrate species showed that the species specificity of the antigenic complexes is determined principally by the species origin of the nonhistone proteins. Our results show that a cell-specific chromosomal nonhistone protein(s) has undergone evolutionary change and the relative immunological differences are consistent with the accepted phylogenetic distances of the species examined.

Animals↗
PubMed1979

Cell specific antiserum to chromosome scaffold proteins.

Antiserum has been raised to a chromosomal protein fraction specific for Hela cells. The immunoactivity is located in the transcriptionally inactive regions of log phase chromatin. Digestion of metaphase chromosomes results in the purification of the immunoactivity in the scaffold region of the chromosomes. Extensive nuclease digestion of the scaffolds results in loss of activity. The data suggest that some of the proteins in the scaffold area are both tight binding and cell specific and may therefore play a sophisticated role in gene expression.

Cell Cycle↗
PubMed1979

Specificity of DNA-associated nuclear antigens in HeLa cells and distribution during the cell cycle.

Chromosomal nonhistone protein:DNA complexes prepared from synchronized HeLa cells were used to immunize white rabbits. The antisera reacted specifically in complement fixation tests with chromatins isolated from HeLa cells and not with those from a number of other human and animal tissues. Specificity to this cell type was also demonstrated by immunocytochemical reaction. Both immunochemical tests revealed that the specific antigens are continuously present throughout the cell cycle. The immunological activity was dependent upon chromosomal nonhistone protein(s) being bound to DNA. Our findings are consistent with these chromatin antigens being stable nuclear components [complexes of chromosomal non-histone protein(s) with DNA] characteristic of cellular differentiation.

Antigens↗
PubMed1978

Human granulocyte specific nuclear antigen(s). I: Production of antisera and determination of specificity.

Non-histone protein-DNA complexes isolated from human lung tissue were used to immunize New Zealand rabbits. Quantitative microcomplement fixation and immunocytochemistry revealed a specific chromatin antigen(s) in the human granulocyte nucleus. The study demonstrates the feasibility of employing antisera against chromosomal non-histone protein-DNA complexes for the immunochemical identification of cell types.

Animals↗