Biomedical subjects

R C Briggs

Publications and source records attributed to R C Briggs.

At least 37 records · Page 2Linked to original sources

PubMed1990

Expression of human myeloid cell nuclear differentiation antigen (MNDA) in acute leukemias.

Human myeloid cell nuclear differentiating antigen (MNDA) is a Mr 55,000 non-histone basic nuclear protein expressed in myeloid leukemia cell lines that are at late stages of differentiation (HL-60 and U937) and in normal granulocytes and monocytes, but is not present in lymphoid cells or in other human cells and tissues tested. Affinity purified monospecific polyclonal antibodies and rat monoclonal antibodies have been developed for the immunocytochemical detection of MNDA. Using these antibodies, we surveyed 21 cases of acute leukemia classified by French-American-British (FAB) Group criteria, two cases of biphenotypic acute leukemia and one case of blast crisis of chronic granulocytic leukemia for the presence of MNDA. The most intense staining reactions were present in the nuclei of two cases of acute promyelocytic (FAB M3) leukemia. MNDA was not detected in three of five cases of acute myeloblastic leukemia without maturation (FAB M1). The remaining two cases of the M1 category showed weak to moderate staining. No staining reaction was seen in acute lymphocytic leukemia (ALL), biphenotypic leukemia or the lymphoid blast crisis of chronic granulocytic leukemia. Variable staining reactions were demonstrated in the remaining cases. These data suggest that the presence of MNDA is correlated with myeloid and monocytic differentiation in acute leukemia, being strongly expressed in M3 type, often not detected in M1 leukemia and absent in ALL.

Acute Disease↗

PubMed1989

Intranuclear distribution of the human myeloid cell nuclear differentiation antigen in HL-60 cells.

Based on solubility properties, the human myeloid cell nuclear differentiation antigen exists as at least two distinct populations. Most is easily extracted from isolated nuclei in 0.35 M NaCl, while 20 percent resists such treatment. Compared to undigested nuclei, both the amount of myeloid cell nuclear differentiation antigen (MNDA) released from nuclei after DNase I treatment and the amount resisting further extraction in 0.35 M NaCl increased after DNA was digested with DNase I. Under these conditions, there was a concomitant decrease in the amount of MNDA that was extractable with 0.35 M NaCl. Mixing nuclear protein extracts that contain MNDA with nuclei from cells that do not express this protein demonstrated that the MNDA redistributes from the freely soluble form to the nuclear residual fraction as a consequence of DNase I digestion. These data are consistent with a model in which the amount of MNDA that is tightly bound to salt-washed nuclei is held constant in the presence of an excess of unassociated MNDA in the nucleus, and that the level of MNDA binding to this nuclear fraction increases in proportion to the extent of DNA damage resulting from DNase I digestion.

Cell Differentiation↗

PubMed1989

In vivo crosslinking of nuclear proteins to DNA by cis-diamminedichloroplatinum (II) in differentiating rat myoblasts.

When cells are briefly exposed to cis-diamminedichloroplatinum (II) before lysis in high sodium dodecyl sulfate-urea solutions, the high molecular-weight nucleic acids pelleted by ultracentrifugation contain an increased level of bound proteins when compared to a similar fraction from untreated cells. Subsequent shearing of the pelleted DNA followed by treatment with DNase permits electrophoretic and immunoblot analysis of the crosslinked proteins. In the present study such experiments were carried out with reference to nuclear envelope pore complex proteins in the differentiating L8 rat skeletal muscle cells. The results show that (i) whereas the major lamin proteins crosslinked to DNA in both myoblast and myotubes, lamin B is crosslinked to a greater extent to DNA in myotubes; (ii) a 62-kDa lectin-binding glycoprotein is apparently situated differently with respect to DNA in myotube nuclei; and (iii) the crosslinking pattern of the nuclear matrix proteins to DNA is qualitatively similar in myoblast and myotubes. In addition, lamin C', a modified form of lamin C, not observed in intact nonmuscle cells previously [Glass et al. (1985) J. Biol. Chem. 260, 1895-1900], exists as a native component of the nuclear lamina in rat skeletal myotubes but not in myoblasts. These results point to significant structural alterations in the proteins of the nuclear lamina-pore complex during myogenesis.

Animals↗

PubMed1989

Balance performance among noninstitutionalized elderly women.

Descriptive data were collected regarding static standing balance of 71 noninstitutionalized elderly women as they performed two timed balance tests. All subjects performed the sharpened Romberg test and the one-legged stance test on each foot in four test conditions: 1) eyes open, 2) eyes closed, 3) shoes on, and 4) shoes off. Subjects were grouped and analyzed according to the following age ranges: 1) 60 to 64 years, 2) 65 to 69 years, 3) 70 to 74 years, 4) 75 to 79 years, and 5) 80 to 86 years. The best time of three trials was used for data analysis. The maximum balance time for the sharpened Romberg test was 60 seconds. For the one-legged stance test, a maximum balance time was 30 seconds. No significant difference was found between right and left or dominant and nondominant limbs while performing the one-legged stance test. No significant difference was found in mean balance time between subjects who had fallen versus those who had not fallen, nor between shoes-on and shoes-off test performance. Subjects' performance on the eyes-open test was consistently superior to their eyes-closed test performance (p less than .0001). The one-legged stance test mean balance time decreased significantly as age increased. More subjects reached the maximum balance time on the sharpened Romberg test than on the one-legged stance test. The results of this study indicate that additional research is needed in the area of balance maintenance among the elderly population.

Aged↗

PubMed1988

Characterization of chromium effects on a rat liver epithelial cell line and their relevance to in vitro transformation.

Chronic exposure to low concentrations or brief exposures to high concentrations of hexavalent chromium (K2CrO4) transformed a rat liver epithelial cell line as assessed by anchorage-independent growth. A clone of the transformed cells produced tumors in syngeneic animals, all of which were determined to be high grade carcinomas. The effects of various doses of chromium on cytotoxicity and cell cycle were established and related to ultimate numbers of transformants in the population. Prior to the onset of cytotoxicity, linear rates of uptake were observed at different external concentrations of chromium and the total intracellular level increased with increasing concentration. This may be due to competition for transport. A plateau in level of chromium accumulation after prolonged exposure to a low concentration (10 microM) of chromium observed with the eventual return to normal growth provided evidence for the induction of a protective mechanism. In addition, cells surviving prolonged treatment with low concentrations of chromium became resistant to the cytotoxic effects of high concentrations of the metal, further suggesting that the cells become adapted to the presence of chromium. An increase in the amount of protein associated with extracted nucleic acids was detected at the optimal transforming dose and this did not correlate with cytotoxic effects. The effectiveness of chromium in transforming the adult rat liver epithelial cell line may depend on the intracellular level of accumulation, the rate of chromium uptake, and the ability of the cell to activate a protective mechanism. The initiation of stable nucleic acid-protein complexes observed under the optimal conditions for transformation may be associated with an inability of the cell to activate a protective mechanism rapidly enough to prevent effects on the nucleus at a high concentration (1 mM) of chromium.

Animals↗

PubMed1988

Lectin-binding proteins in nuclear preparations from rat liver and malignant tumors.

Lectin binding [concanavalin A, biotinylated ricinus communis agglutinin, and biotinylated succinylated wheat germ agglutinin (B-SWGA)] was used to detect the glycosylated proteins associated with a residual protein fraction [insoluble in 4% sodium dodecyl sulfate and termed the nuclear residual fraction (NRF)] or with nuclear matrix preparations from normal rat liver, azo dye (3'-MeDAB)-induced rat hepatoma, and Walker 256 transplantable carcinosarcoma. One- and two-dimensional gel electrophoresis were used with lectins, polyclonal antisera, and monoclonal antibody binding to characterize some of the glycoconjugates. Two polypeptide bands with approximate molecular weights of 95,000 and 55,000, shown previously to be present only in the induced tumor cells and the Walker 256 tumor, were reactive with lectins. In addition, a Mr 62,000 protein reacted only with B-SWGA in the nuclear matrix fractions from normal rat liver and the induced hepatoma. A polypeptide band (approximate molecular weight, 213,000) in the Walker 256 NRF reacted with concanavalin A and biotinylated ricinus communis agglutinin. One polypeptide band (approximate molecular weight, 182,000) reacted with concanavalin A in all three tissues, with biotinylated ricinus communis agglutinin and B-SWGA in the Walker NRF, and with B-SWGA in the hepatoma NRF. Another polypeptide band (approximate molecular weight, 138,000), reactive with all three lectins, was present in all three tissues. Our findings are consistent with previous reports of lectin binding proteins in the eukaryotic cell nucleus and indicate that certain glycoproteins isolated in nuclear preparations are found specifically in 3'-MeDAB-induced hepatoma and Walker 256 transplantable carcinosarcoma.

Animals↗

PubMed1988

A nuclear cAMP binding protein in retinoic acid-treated HL-60 cells.

A cAMP binding protein was detected in HL-60 cells using photoaffinity labeling with 8-azido [32P]cAMP. The binding protein was found in a 0.35 M NaCl nuclear protein extract from untreated HL-60 cells and from the HL-60 cells induced to mature with retinoic acid. While the quantity of the cAMP binding protein did not change following the induced differentiation, a second form of the subunit, altered in charge, was present at 3 and 5 days after retinoic acid treatment. The findings indicate that the regulatory subunit of the type II cAMP-dependent protein kinase could be involved in nuclear functions associated with human myeloid cell differentiation.

Azides↗

PubMed1988

Production and use of rat monoclonal antibodies to the human myeloid cell nuclear differentiation antigen.

A dot immunoblot screening assay was used to identify rat monoclonal antibodies to a human myeloid cell differentiation-specific nuclear antigen (MNDA). The selection was based on the positive reaction of hybridoma cell supernatants with a concentrated nuclear protein extract prepared from late stage human myeloid leukemia cells that express MNDA (HL-60) coincident with a negative reaction with the same extract prepared from a non-expressing more immature human myeloid leukemia cell line. The approach provided an efficient method for obtaining monoclonal antibodies to a specific low abundance nuclear antigen that has not been purified. Sixteen wells from three fusions contained antibody displaying a specific reaction with the nuclear protein fraction obtained from the HL-60 cells. Immunoblotting analysis revealed that all of the sixteen specific hybridoma cell lines produced antibody against the same Mr 55,000 nuclear antigen. Selecting hybridoma cells that produce antibody reactive with the native antigen provided antibody suitable for detecting MNDA in immunocytochemical tests. The rat monoclonal antibodies were purified and coupled to CNBr-activated agarose and carbonyldiimidazole-activated agarose. Although both antibody affinity matrices exhibited the same antigen binding capacities, the matrix prepared using carbonyldiimidazole-activated agarose bound the MNDA with a high level of specificity while the matrix prepared from CNBr-activated agarose bound numerous other nuclear proteins.

Animals↗

PubMed1987

In vivo DNA-protein cross-linking by cis- and trans-diamminedichloroplatinum(II).

When Novikoff hepatoma-bearing rats were given injections of a therapeutic dose of cis-diamminedichloroplatinum(II) (cis-DDP) (7 mg/kg), DNA-protein cross-links could be detected by using antisera to dehistonized chromatin, nuclear matrix, or Novikoff hepatoma cytoskeletal preparation. The extent of cross-linking increased in time up to 24 h after the injection, after which time the DNA-protein cross-links were gradually repaired, with no cross-links detectable at 72 h. trans-DDP in equitoxic (40 mg/kg) dose was very efficient in forming DNA-protein cross-links. Although formed more rapidly, these trans-DDP-mediated cross-links were repaired faster, within 48 h after the injection. The repair of cross-links at equimolar trans-DDP dose (7 mg/kg) was even more rapid. The principal proteins cross-linked to the DNA by both cis- or trans-DDP were Novikoff hepatoma cytokeratins (Mr 39,000, 49,000, 56,000, and an additional protein band reacting with the antiserum to Novikoff hepatoma cytoskeletal preparation at Mr approximately 68,000).

Animals↗

PubMed1987

Comparison of chicken erythroid cell nuclear isolation methods using morphological, immunochemical and biochemical criteria.

Chicken erythroid nuclei were prepared using four published methods. Our findings indicate that nuclei prepared by nitrogen cavitation are less likely to be contaminated with plasma membrane fragments than those made by procedures involving cell disruption by hypotonic lysis. However, globin gene sequences were much less sensitive to DNase I digestion in nuclei prepared by nitrogen cavitation. This suggests that the conformation of chromatin was altered by the cavitation procedure. Analysis of the proteins solubilized during limited DNase I digestion of nuclei prepared by both hypotonic lysis and cavitation revealed no appreciable differences in HMG proteins but a notable difference in the RNP-associated proteins and core histones.

Animals↗

PubMed1987

Specificity of non-histone protein antigens in chicken liver nuclei.

1. Chicken liver nuclei were fractionated by disruption with ultrasound and subsequent precipitation with divatent cations. A small, protein-rich fraction (CS), representing less than 5% of the total nuclear DNA reacted strongly with antisera to dehistonized chicken liver chromatin. 2. Further fractionation of the CS by DNA-affinity chromatography yielded two DNA-binding immunoreactive proteins (approximate Mr 35 and 56 kD). 3. We have shown previously (Kiliańska et al., 1981, Kiliańska, 1984) that this DNA-binding component strongly inhibited the in vitro transcription of RNA.

Animals↗

PubMed1987

Colloid shift following blunt trauma.

Thirty-three patients who underwent spleen imaging with [99mTc]sulfur colloid following blunt trauma to the left chest and/or left upper abdominal quadrant were evaluated. Nineteen of these patients were found to have reversed liver-spleen activity ratios (colloid shift). The incidence of this finding was surprising in view of the absence of any predisposing factors in these patients. Colloid shift was seen as early as 2 hr after trauma and was found to persist as long as 188 days after the traumatic event. The explanation for colloid shift in this group of patients is unknown, but the results suggest that it is secondary to reticuloendothelial system stimulation.

Humans↗

PubMed1986

Properties of a nuclear protein marker of human myeloid cell differentiation.

The Mr 55,000 nuclear antigen present in the human promyelocytic cell line HL-60 is a basic protein that is extracted from nuclei or chromatin by 0.35 M NaCl. The antigen is confined to the nucleus of the interphase HL-60 cell as judged by immunocytochemical localization but disperses throughout the cell during mitosis. The antigen was not detected in leukemic cell lines with blast cell properties or in cell lines representing other lineages. Additional cell lines (ML-1, ML-2, and U937) with myeloid cell characteristics similar to those of the HL-60 cells, which also differentiate in vitro, express the antigen. The presence of antigen in normal human myeloid cells in peripheral blood and bone marrow is consistent with its proposed role in nuclear events associated with normal human myeloid cell differentiation.

Antibodies↗

PubMed1985

cis-Diamminedichloroplatinum-mediated crosslinking of nuclear proteins to DNA is cell cycle specific.

Immunochemical analysis was employed to investigate the cell cycle-dependent protein-DNA crosslinking by cis-diamminedichloroplatinum II (cis-DDP), in HeLa-S3 cells. Cells synchronized by double thymidine block or hydroxyurea were released into S phase and incubated at 2-h intervals with cis-DDP as they progressed through S1, G2, M, and then into G1 and S phases of the subsequent cycle. Immunoblots of the DNA-crosslinked antigens reacted with antisera to 0.35 M NaCl extract or residue of HeLa S-phase nuclei revealed that several antigens changed their DNA-crosslinking pattern during the progression of HeLa cells through their reproductive cycle.

Cell Cycle↗

PubMed1985

Enzymatic modification of Novikoff hepatoma lamins A and C.

A significant increase in the molecular weights of lamin A and more so of lamin C was observed when isolated Novikoff hepatoma chromatin was incubated in the presence of Ca2+. This increase did not occur to any significant degree in similar preparations of normal rat liver nuclei. Although detectable in Coomassie Brilliant Blue stained gels, this increase to a higher molecular weight (by approximately 2000 Mr) was much more visible when the electrophoretically separated lamins were transferred to nitrocellulose sheets and stained (using peroxidase-antiperoxidase) with polyclonal antiserum to the three major lamin proteins. This modification could also be induced when whole Novikoff hepatoma cell lysates were incubated in the presence of calcium. Again, this change did not occur in normal rat liver cells treated in the same manner. Further analysis has provided evidence that this modification is most likely mediated by the transaminating activity of an intrinsic nuclear transglutaminase forming a cross-link between the affected lamins and an unknown low molecular weight (approximately equal to 2000 Mr) moiety.

Acyltransferases↗

PubMed1985

Effects of hemin on a lymphoblastoid cell line that expresses the human epsilon- and gamma-globin genes.

Northern blot analysis using probes specific for each of the human embryonic (epsilon), fetal (gamma), and adult (beta) globin genes indicates that the human lymphoblastoid F-265 cells express the embryonic and fetal globin genes. Unlike the erythroid cell line K562, in which globin RNA levels increase during treatment with hemin in culture, globin RNA levels decrease in F-265 cells in the presence of hemin. This effect is reversible after passage of F-265 cells in fresh medium without hemin. Both the rates of globin RNA synthesis and the presence of DNase I-hypersensitive sites in hemin treated and untreated F-265 cells were investigated to identify the levels at which globin gene expression is controlled.

Cell Line↗

PubMed1985

Nuclear antigens in the HeLa cell cycle.

Antisera to 0.35 M NaCl extracts and residues of S phase HeLa nuclei were reacted with electrophoretically separated proteins from the nuclei or nuclear material of HeLa cells synchronized in G1, S, G2 or M phases of the cell cycle. Quantitative evaluation of the peroxidase-antiperoxidase stained nitrocellulose transfers (Western blots) revealed significant changes in the quantities of nuclear non-histone proteins during the cell cycle. Immunochemical staining of electrophoretically separated nuclear antigens permits their selective detection in minute quantities and in the presence of many additional proteins.

Antigens↗

PubMed1984

cis- and trans-Diamminedichloroplatinum(II)-mediated cross-linking of chromosomal non-histone proteins to DNA in HeLa cells.

The cross-linking of chromosomal non-histone proteins to DNA in isolated nuclei or intact HeLa cells exposed to different concentrations of cis- and trans-diamminedichloroplatinum(II) (cis- and trans-DDP) for various time intervals was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunochemical methods. Both the cis- and the trans-DDP cross-linked significant numbers of chromosomal non-histone proteins to the DNA. The quantity and the types of the cross-linked proteins depended on the time of incubation as well as on the concentrations of the drugs. The immunochemical techniques revealed that both the 0.35 M sodium chloride insoluble and soluble chromosomal non-histone proteins were cross-linked to the DNA by both isomers. The action of cis- and trans-DDP was reversed and/or blocked by thiourea or 2-mercaptoethanol. Pretreatment of isolated nuclei or chromatin with iodoacetamide or N-ethylmaleimide did not prevent the DNA-protein cross-linking.

Chromosomal Proteins, Non-Histone↗