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Biomedical subjects

G B Price

Publications and source records attributed to G B Price.

At least 19 recordsLinked to original sources
PubMed1992

Cellular heterogeneity in human transitional cell carcinoma: an analysis of optical properties and lectin binding.

Flow cytometry was used to measure the binding of a panel of ten fluorescein isothiocyanate(FITC)-conjugated lectins to fifteen samples of normal and neoplastic human urothelium. Concurrent measurement of light scattering and fluorescence permitted the quantification of lectin binding to cellular subpopulations defined by their light-scattering properties. In normal urothelium, we previously demonstrated levels of lectin binding to the cellular subpopulations derived from the superficial and intermediate cell layers which were higher than levels which bound to the subpopulation derived from the basal cell layer (Ward et al., 1987). This difference was most marked with Maclura pomifera agglutinin (MPA), Ricinus communis agglutinin (RCA) and Ulex europeus agglutinin (UEA). We now report a similar correlation between the degree of differentiation of a cellular subpopulation and the level of lectin binding in human transitional cell carcinomas (TCCs). Morphological differentiation in human TCCs is accompanied by alterations in cell-surface carbohydrates which are similar to those which accompany cellular differentiation in the corresponding normal tissue. No systematic difference in lectin binding was observed between the corresponding subpopulations of normal and neoplastic urothelial cells.

Carbohydrate Metabolism↗
PubMed1992

ORS12, a mammalian autonomously replicating DNA sequence, is present at the centromere of CV-1 cell chromosomes.

ors12, an 812-bp-long sequence, previously isolated by extrusion of nascent DNA from replication bubbles active at the onset of S phase (G. Kaufmann, M. Zannis-Hadzopoulus, and R. G. Martin Mol. Cell. Biol. 5, 721-727, 1985), has been shown to function as an origin of DNA replication in autonomously replicating plasmids (L. Frappier and M. Zannis-Hadjopoulos Proc. Natl. Acad. Sci. USA 84, 6668-6672, 1987) and in a cell-free system (C. E. Pearson, L. Frappier, and M. Zannis-Hadzopoulos Biochim. Biophys. Acta 1090, 156-166, 1991). A portion of ors12 (nucleotides 1-168) consists of the highly reiterated alpha-satellite sequence (B. S. Rao et al. Gene 87, 233-242, 1990). We have estimated the copy number of the non-alpha-satellite portion of ors12 in CV-1 cells to be < 9 copies per haploid genome and have used it as a probe to generate a genomic map of ors12 on CV-1 DNA. In situ hybridization of CV-1 metaphase chromosomes, using a biotinylated probe of the entire ors12 sequence, positively identified the centromeres of all chromosomes. However, when the non-alpha-satellite portion of ors12 was used as a probe, it positively identified the centromeric region of only six chromosomes, namely, B4, C11, D14, D24, E25, and E27, as well as that of a marker chromosome. The results suggest that ors12 represents a centromeric putative replication origin that is present on a subset of CV-1 chromosomes and is activated at the onset of S phase.

Animals↗
PubMed1992

Human antiglioma monoclonal antibodies from patients with astrocytic tumors.

The current management of malignant gliomas is unsatisfactory compared to that of other solid tumors; the expected median survival period is less than 1 year with the patient undergoing conventional surgery, radiotherapy, and chemotherapy treatment. Immunological reagents could be a useful adjunct. Human monoclonal antibodies derived from patients with astrocytic tumors might recognize subtle antigenic specificities that would differ from those recognized by xenogeneic (murine) systems. Five hybridomas, designated as BT27/1A2, BT27/2A3, BT32/A6, BT34/A5, and BT54/B8, were produced from the fusion of peripheral blood lymphocytes of four patients with astrocytic tumors to the human myeloma-like cell line TM-H2-SP2. This cell line has a 46, XX karyotype and is negative for hypoxanthine guanine phosphoribosyltransferase. All five human monoclonal antibodies produced 2.4 to 44 micrograms/ml of immunoglobulin M, had a similar but not identical pattern of reactivity against a panel of human tumor cell lines, and failed to react with normal human astrocytes. Labeling of four neuroectodermal tumor explant cultures by BT27/2A3 was demonstrated by flow cytometry. Karyotyping of three of the five hybridomas demonstrated that two were pseudodiploid (2-3n) and one hypodiploid (less than 2n). The monoclonality of the hybridomas was evaluated by Southern blot analysis of JH gene rearrangements, revealing two types of rearrangements for each hybridoma, both consistent with monoclonality. Preliminary antigen characterization indicated that at least four of the five human monoclonal antibodies were directed to cell-surface glycolipids.

Adolescent↗
PubMed1979

Characterization of stem cells and progenitors of hemopoiesis by cell sorting.

Cell sorting has been used as a method for characterizing hemopoietic stem cells and progenitors. Fluorescent antibody-surface labels and changes in fluorescence polarization induced by in vitro stimulation with potential hemopoietic regulators were used. As detected by significant enrichment of CFU-S (pluripotent stem cells) in fluorescence-activated cell sorting, some CFU-S bear 'unique antigens' recognized by rabbit anti-human brain sera, human anti-human sperm sera, and 129 anti-F9 serum, but not A . TH anti-A . TL (Ia) ascites. Significant changes in fluorescence polarization induced by in vitro stimulation of mouse bone marrow with potential hemopoietic regulators were also observed; further, progenitors of human T-lymphocyte colonies were observed to exhibit a significantly decreased mean polarization value after short-term stimulation with PHA-LCM (phytohemagglutinin-stimulated leukocyte conditioned medium).

Animals↗
PubMed1979

The role of macrophages in stimulation of immune induction and myelopoiesis. I: Comparison of activity of macrophage-derived factors in granulopoiesis and immunostimulation.

Hemopoietic growth and immunological inductive factors from human peripheral leukocyte conditioned medium and mouse macrophage culture supernatant fluids were compared. Factors derived from human peripheral leukocyte conditioned medium were found to substitute for those of mouse macrophage derivation in immunological assays, namely, induction of a cytotoxic T-lymphocyte response in macrophage-depleted mouse spleen cultures. Association of macrophage-derived factors with B2-microglobulin (B2m) antigen determinants was observed by inhibition with great antihuman B2m, affinity chromatography, and direct replacement of mouse macrophage-derived factors with human urinary B2m.

Animals↗
PubMed1979

The role of macrophages in stimulation of immune induction and myelopoiesis: II: analysis of genetic restriction involved in the stimulation of granulocyte colony precursors or mature lymphocytes using factors prepared from different recombinant inbred strains of mice.

The genetic restriction involved in the reconstitution of immune responses in macrophage-depleted mouse spleen cultures, or the induction of colony formation in bone marrow cultures, by different molecular-weight species of lymphostimulatory molecules derived from mouse peritoneal cell suspensions is reported. The data suggest little evidence for genetic restriction in the ability of any of the factors to stimulate bone marrow colony formation in vitro. However, when immunological stimulation was investigated, a restriction coded for by genes in the K/D end of the MHC (70-90K factor) or in the I region of the MHC (30-45K factor) was observed. A third species of lymphostimulatory molecule (15K) showed no such restriction. Further evidence is presented to suggest that the active moiety in the 70-90K molecule(s) is a 15K-like species (nonrestricted in its ability to reconstitute cells from different strains of mice.

Animals↗
PubMed1979

Hemopoietic stem cells bear sperm-associated antigens.

A fluorescence-activated cell sorter has been used to sort out enriched populations of murine hemopoietic stem cells from mouse bone marrow, based on fluorescence of cells labeled with various antisera. Significant positive enrichment for stem cells was obtained with rabbit anti-human brain, human anti-human sperm and mouse anti-mouse F9 sera but not with mouse anti-mouse Ia serum. These results support the hypothesis that the hemopoietic stem cell exhibits 'unique' surface antigens cross-reactive with sperm, brain and embryonic antigens.

Animals↗
PubMed1978

Structure analysis of small proteins by electron microscopy: valinomycin, bacitracin and low molecular weight cell growth stimulators.

Dark field electron microscopy was combined with optical filtering to study at high resolution the structure of the cyclopeptide antibiotics, bacitracin and valinomycin, and two proteins of unknown structure, LMW-CSA N and B, low molecular weight granulocyte colony stimulating activity isolated from medium conditioned with normal or leukemic leukocytes. For bacitracin and valinomycin the images faithfully represented the known structural features at a resolution of 0.5 nm or better, depicting a two-ring structure for bacitracin, as well as the position of the potassium ion in valinomycin. Both proteins of unknown structrue had at least one cyclic peptide portion. LMW-CSA N had a size of 2.0 nm, LMW-CSA B of 2.4 nm. A potential site of the calcium ionophoric activity in the latter protein was found to be in the larger of the two ring portions constituting the molecule.

Bacitracin↗
PubMed1978

The production of hemopoietic growth factors by PHA-stimulated leukocytes.

Conditioned medium from cultures of phytohemagglutinin-stimulated leukocytes has been assessed for its content of factors able to stimulate either colony formation by human granulopoietic progenitor cells, or 3H-thymidine incorporation by peripheral leukocytes from leukemic patients. The cell concentration, concentration of phytohemagglutinin and time required for optimal production of factors were investigated. Production of both classes of factors was found to be insensitive to inhibitors of cell proliferation and DNA synthesis, but sensitive to inhibition of protein synthesis by cycloheximide. The production of colony stimulating activity showed a markedly greater sensitivity to cycloheximide than did production of thymidine-incorporating activity. For cycloheximide and most of the other inhibitors studied, factor production by leukemic cell populations was affected to a somewhat greater extent than production by normal leukocytes. Separation by velocity sedimentation of the cells responsible for production provided no evidence for distinct classes of cells producing these two classes of factors.

Cell Division↗
PubMed1977

Measurement of cytoplasmic fluorescence depolarization of single cells in a flow system.

We have built a flow system in which we can analyze and sort individual viable cells on the basis of their cytoplasmic microviscosity. The average cytoplasmic microviscosity (or cytoplasmic structuredness) of a cell can be quantitated by exciting fluorescein molecules in the cytoplasm of the cell with a polarized light source and measuring the extent of depolarization of the fluorescent signal. Changes in the state of a cell (e.g., the reception of a signal inducing the cell to differentiate) often appear to be associated with changes in cytoplasmic microviscosity, these changes being detectable within hours of the inducing signal. An example of one such change is presented.

Bone Marrow↗
PubMed1977

Chronic myeloid leukemia: physical and functional similarities to acute leukemia.

Blast crisis, closely resembling acute leukemia, is the usual terminal event in chronic myeloid leukemia. Using physical ("fingerprint") and cultural (colony-forming) methods, we have demonstrated distinctive patterns in the stable phase of chronic myeloid leukemia and in blast crisis. An unusual fingerprint alteration preceding the onset of the terminal phase is noted, and cell culture perturbation is evident at different stages of the disease. Our findings indicate that the application of these methods to the study of hemopoietic disorders is valid, and suggest that the use of such techniques may allow a better understanding of the complex cellular events occurring in the course of chronic myeloid leukemia.

Acute Disease↗
PubMed1977

Serologic identification of hemopoietic progenitor cell antigens common to mouse and man.

An immunologic approach to the identification of human hemopoietic stem cell antigens has yielded two types of antisera. Both recognize antigens on hemopoietic progenitors which are identical or cross-reactive with determinants on sperm, brain, and, across the species barrier, with murine hemopoietic stem cells (CFU-S). The first antiserum was the result of an autoimmune reaction in a post-vasectomy patient. The second was produced in rabbits after injection of human brain cells.

Animals↗