Search PubMed⌕ Search

Biomedical subjects

C N Frantz

Publications and source records attributed to C N Frantz.

At least 37 records · Page 2Linked to original sources
PubMed1988

Macrophage colony-stimulating factor in nerve growth factor preparations.

Following a report that nerve growth factor preparations have granulocyte-colony-stimulating activity, we investigated the presence of colony-stimulating factors in 7s mouse submaxillary nerve growth factor and its subunits. Macrophage colonies were formed in mouse bone marrow cultures after exposure to preparations of 7s nerve growth factor, the gamma subunit, and, to a small extent, the alpha subunit; the beta subunit, which is responsible for the nerve growth function, did not stimulate colony growth. Furthermore, the esteropeptidase activity of the gamma subunit was not detected in preparations of macrophage colony-stimulating factor purified from the giant cell tumor (GCT) cell line. Immunoprecipitation of radiolabeled gamma subunit with a polyclonal antibody to L-cell macrophage colony-stimulating factor showed a protein band that could represent the gamma subunit of nerve growth factor. Separation of the macrophage activity from the esteropeptidase activity of the gamma subunit was accomplished on the basis of molecular size. Thus, macrophage colony-stimulating factor was a contaminant of nerve growth factor produced by the mouse submaxillary gland and copurified with the gamma subunit.

Animals↗
PubMed1986

A monoclonal anti-neuroblastoma antibody that discriminates between human nonhematopoietic and hematopoietic cell types.

A murine IgG2a monoclonal antibody, termed 6-19, was characterized in terms of its ability to bind to human cell lines and tissues. The hybridoma was selected for antibody binding to multiple human neuroblastoma cultured cell lines but not to peripheral blood mononuclear cells. 6-19 binds to the cell surface of all cultured human nonhematopoietic tumor cell lines tested, to cultured human fibroblasts and endothelial cells, and to nonhematopoietic tumors of many types. It does not bind detectably to any hematopoietic cells, leukemia cells, or lymphomas. In the presence of complement, 6-19 is very cytotoxic to cultured human neuroblastoma cells but not to bone marrow granulocyte-macrophage colony-forming cells. The 6-19 monoclonal antibody may prove useful in the identification or destruction of tumor and stromal cells in bone marrow.

Animals↗
PubMed1986

Variables affecting the killing of cultured human neuroblastoma cells with monoclonal antibody and complement.

To determine incubation conditions that result in optimal in vitro killing of human tumor cells with monoclonal antibody and complement, variables affecting the killing of cultured human neuroblastoma cells with monoclonal antibody 6-19 and baby rabbit complement were studied. Neuroblastoma target cells were stained with the fluorescent dye Hoechst 33342, which enables rapid, sensitive detection of surviving cells in conjunction with trypan blue exclusion. Maximal cell lysis was obtained at an antibody concentration of 5-10 micrograms/ml. Greater than 5 logs of cell kill were obtained with appropriate treatment conditions. No antigenic modulation was detected. Complement activity was found to be the factor which limited the extent of cell kill. Specific cell lysis increased with increasing concentration of complement. As the reaction with antibody coated cells proceeded, complement activity was depleted. This resulted in the greatest cell kill occurring during the first 10-20 min of treatment. Generation of factor(s) inhibitory to complement activity was also found. However, the effect of inhibition on limiting the extent of cell kill was much less significant than the effect of complement depletion. When compared to a single incubation of the same total duration, the reduction in complement activity with duration of incubation resulted in greater killing by multiple brief incubations with fresh complement. The depletion of complement was found to increase at a greater cell concentration. This resulted in greater proportional survival as neuroblastoma cell concentration increased. Depletion of complement activity by aggregated monoclonal antibody was found to decrease cytotoxicity. This evaluation may provide a framework for optimization of target cell destruction using complement and other monoclonal antibodies and target cells.

Antibodies, Monoclonal↗
PubMed1986

Phosphorylation of a 75,000 molecular weight cytosol protein induced by platelet derived growth factor and tumor promoter in BALB/c-3T3 cells.

In order to identify common mechanisms of action by which both the platelet-derived growth factor (PDGF) and the tumor promoter tetradecanoyl phorbol acetate (TPA) initiate cell growth, the effects of PDGF and TPA on phosphorylation of cellular proteins were examined in density-inhibited Balb/c-3T3 cells. Cultures were incubated with 32Pi and growth factor, and 32P-labeled cellular proteins were examined after separation by SDS-polyacrylamide gel electrophoresis and autoradiography. TPA and PDGF each induced phosphorylation of a major cytosol protein of approximately 75,000 molecular weight (pp75). Phosphorylation of this protein was not induced by either epidermal growth factor or insulin, neither of which initiate 3T3 cell growth but enhance growth later in the 3T3 cell cycle. pp75 was a single band under reduced and non-reduced conditions, and a single spot was seen on two-dimensional gels. Phosphorylation did not occur at 4 degrees C. Phosphorylation of the protein was observed within 3 min and reached a maximum in 10-30 min. Submitogenic doses of TPA and PDGF induced submaximal phosphorylation. The phosphoprotein was labeled only on serine. Cell free phosphorylation of pp75 occurred at 4 degrees C in the presence of Mg++ and Ca2+. Homogenates from cultures pretreated with TPA phosphorylated pp75 in the presence or absence of Ca2+. Phosphorylation of this protein may possibly be related to activation of the Ca2+-dependent, phospholipid sensitive protein kinase C.

Animals↗
PubMed1986

Lysis of human fibroblast colony-forming cells and endothelial cells by monoclonal antibody (6-19) and complement.

The murine IgG2a monoclonal antibody 6-19 binds to a wide variety of nonhematopoietic cells including human marrow-derived stromal cells but does not bind to marrow or peripheral blood cells. We studied the effects of this antibody and rabbit complement on marrow cells. Fibroblast colonies were eliminated from light density marrow cells by a single incubation with monoclonal antibody 6-19 and complement. The growth and composition of granulocytic and erythroid colonies were unaffected. Specific complement mediated cytotoxicity of the antibody was confirmed on passaged human fibroblasts derived from marrow (more than 99.6% of fibroblasts are killed by a single treatment). Similar results were obtained with human umbilical cord endothelial cells. In addition, such treatment abolished the initiation of Dexter culture stroma. Incubation of bone marrow cell suspensions with this antibody and complement will allow the study of stroma-free marrow cells in long-term liquid cultures.

Antibodies, Monoclonal↗
PubMed1985

A sensitive assay of cytotoxicity applicable to mixed cell populations.

The fluorescent vital dye, Hoechst 33342, was used to stain cultured cells prior to assay of antibody dependent complement mediated cytotoxicity. The fluorescence of nonviable dye stained cells is quenched by cellular uptake of trypan blue, but trypan blue excluding cells remain intensely fluorescent. Detection by fluorescence microscopy of one viable prestained cell per 10(5) unstained cells was accurate and reliable. The technique was found to have sensitivity equal to a clonogenic assay for measuring cytotoxicity. The dye stained cell assay may be used to measure depletion of a selected cell type, when those cells are stained prior to mixing with another cell population. This technique may prove useful to study model systems for depletion of tumor cells or T-cells from bone marrow.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1985

Stage IV-N: a favorable subset of children with metastatic neuroblastoma.

Among children over 1 year of age with Evans Stage IV neuroblastoma, there appears to be a small group with a relatively favorable prognosis. These patients have extensive lymph node metastases (cervical/axillary/thoracic/abdominal/pelvic), but no extranodal metastases. Three of six such patients (50%) are long-term disease-free survivors, compared with none of 40 patients with extranodal metastatic disease (p less than 0.0002). Patients with only lymph node metastases (Stage "IV-N") may have a biologically more favorable tumor that is curable with conventional, intensive multimodality therapy.

Abdominal Neoplasms↗
PubMed1985

Effects of platelet-derived growth factor on Ca2+ in 3T3 cells.

The effect of platelet-derived growth factor (PDGF) on cellular Ca2+ was examined in BALB/c-3T3 cells. PDGF induced: A decrease in cell 45Ca2+ content. An apparent increased rate of efflux of preloaded 45Ca2+. A decrease in residual intracellular 45Ca2+ remaining after rapid efflux. When added after the rapid phase of efflux of 45Ca2+ had occurred, an immediate decrease in post-efflux residual intracellular 45Ca2+. All of the observed changes in 45Ca2+ induced by PDGF are consistent with a rapid release of Ca2+ from an intracellular Ca2+ pool that has the slowest efflux and is relatively inaccessible to extracellular EDTA. When incubated with chlortetracycline (CTC), a fluorescent Ca2+ probe, 3T3 cell mitochondria became intensely fluorescent. Addition of PDGF resulted in a rapid decrease in CTC fluorescence intensity in both adherent and suspended 3T3 cells. The effects of PDGF on 3T3 cell Ca2+ stores and CTC fluorescence intensity were identical with the effects of the Ca2+ ionophore A23187 and of the proton ionophore carbonyl cyanide m-chlorophenyl hydrazone. Serum, which contains PDGF, also altered intracellular Ca2+ stores, but platelet-poor plasma, which does not contain PDGF, had no effect. EGF, insulin, and tetradecanoyl phorbol acetate (TPA), other factors which stimulate 3T3 cell growth, did not alter 3T3 cell Ca2+ stores. Release of Ca2+ from intracellular sequestration sites may be a mechanism by which PDGF stimulates cell growth.

Animals↗
PubMed1985

Anti-neuroblastoma monoclonal antibodies which do not bind to bone marrow cells.

Three previously unreported mouse monoclonal antibodies are described. All three bind to cultured human neuroblastoma cells from six of six cell lines, but do not detectably bind to human bone marrow cells. The two IgG2a monoclonal antibodies bind to greater than 98% of the cultured cells from each cell line, bind to six of six human neuroblastoma tumors by immunoperoxidase histochemistry, and are cytotoxic with complement to cultured human neuroblastoma cells but not to human bone marrow granulocyte-macrophage colony-forming cells.

Animals↗
PubMed1984

Ganglioneuroma presenting with differentiated skeletal metastases. Report of a case.

The authors report the case of a child with retroperitoneal ganglioneuroma and cytodifferentiated skeletal metastases. The primary tumor was surgically resected, and the child is alive and well 2 years later without additional therapy. This rarely documented phenomenon can be explained by spontaneous cytomaturation within both primary and metastatic tumor.

Bone Neoplasms↗
PubMed1984

Influence of local-regional lymph node metastases on prognosis in neuroblastoma.

Data relative to the prognostic and therapeutic significance of lymph node metastases in regionally confined neuroblastoma (Evans stages II-III) are scant. We have analyzed lymph node status in order to assess the significance of nodal involvement. Disease-free survival (minimum follow-up of 2 years) was 84% (21/25) among node-positive patients compared with 95% (18/19) for node-negative patients (P greater than 0.1, two-tailed test). These results contrast with the results from two other centers in which lymph node involvement was a significant adverse prognostic indicator. The use of intensive multimodal therapy including surgical resection of the primary tumor, wide-field radiation therapy to the tumor bed and regional lymph nodes, and chemotherapy may have accounted for the better survival in our node-positive patients.

Combined Modality Therapy↗
PubMed1984

Improved survival in neuroblastoma using multimodality therapy.

One hundred and thirty-six patients with neuroblastoma have been treated at our center from 1970 to 1982, using various combinations of surgery, radiation therapy, and chemotherapy. Choice of therapy was individualized but depended primarily on age and stage. The overall disease-free survival was 60% (minimum follow-up of one year). Patients with stage I disease and younger patients with stage II disease usually received less intensive therapy and fared extremely well (100% survival). Patients with stage III disease and older patients with stage II disease also did extremely well (survival of 85% and 90%, respectively). These patients may have benefited from intensive treatment with all three modalities. Patients under one year of age with stage IV neuroblastoma were treated with surgery and multiagent chemotherapy, and 92% (11/12) survived free of disease. Patients over one year old with stage IV disease represented the only group for which therapy was unsuccessful (10% survival). With combination approaches and with more effective multiagent chemotherapeutic regimens, a real impact on the survival of older stage II patients, stage III patients, and younger stage IV patients appears to have been made. However, older stage IV patients are rarely cured with conventional therapy, and better approaches will be needed for this group.

Adolescent↗
PubMed1984

Neuroblastoma: the Joint Center for Radiation Therapy/Dana-Farber Cancer Institute/Children's Hospital experience.

The treatment results for 118 patients with neuroblastoma seen at the Joint Center for Radiation Therapy/Dana-Farber Cancer Institute/Children's Hospital from 1970 to 1980 were analyzed. Patients were treated with a combination of surgery, radiation therapy, and chemotherapy depending on stage and age. Disease-free survival was excellent in all patient groups except those over one year of age with stage IV disease, a group for which currently available therapy cures only a small proportion of patients. Patients with stage III disease and older patients with stage II disease did extremely well (survival of 81% and 89%, respectively) and may have benefited from intensive treatment with all three modalities. Survival for infants (under one year) with stage IV neuroblastoma (90%) has clearly improved with intensive combination chemotherapy. With combination approaches and newer, more effective systemic regimens, a real impact on survival appears to have been made in the last decade. Better approaches will be necessary to cure more than an occasional older patient with stage IV disease.

Abdominal Neoplasms↗
PubMed1984

Improved prognosis for infants with stage IV neuroblastoma.

From 1970 to 1982 11 infants with Evans stage IV neuroblastoma who were 11 months of age or less at diagnosis were treated. All but one were treated with intensive multiagent chemotherapy; eight had attempted surgical resection; only one received radiotherapy to the primary tumor. Ten of the 11 infants remain free of disease from 2 1/2 to 13 years (median, four years). Multiagent chemotherapy has clearly improved the outcome for infants with stage IV neuroblastoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1981

Intracellular univalent cations and the regulation of the BALB/c-3T3 cell cycle.

Addition of serum to density-arrested BALB/c-3T3 cells causes a rapid increase in uptake of Na+ and K+, followed 12 h later by the onset of DNA synthesis. We explored the role of intracellular univalent cation concentrations in the regulation of BALB/c-3T3 cell growth by serum growth factors. As cells grew to confluence, intracellular Na+ and K+ concentrations ([Na+]i and [K+]i) fell from 40 and 180 to 15 and 90 mmol/liter, respectively. Stimulation of growth of density-inhibited cells by the addition of serum growth factors increased [Na]i by 30% and [K+]i by 13-25% in early G0/G1, resulting in an increase in total univalent cation concentration. Addition of ouabain to stimulated cells resulted in a concentration-dependent steady decrease in [K+]i and increase in [Na+]i. Ouabain (100 microM) decreased [K+]i to approximately 60 mmol/liter by 12 h, and also prevented the serum-stimulated increase in 86Rb+ uptake. However, 100 microM ouabain did not inhibit DNA synthesis. A time-course experiment was done to determine the effect of 100 microM ouabain on [K+]i throughout G0/G1 and S phase. The addition of serum growth factors to density-inhibited cells stimulated equal rates of entry into the S phase in the presence or absence of 100 microM ouabain. However, in the presence of ouabain, there was a decrease in [K+]i. Therefore, an increase in [K+]i is not required for entry into S phase; serum growth factors do not regulate cell growth by altering [K+]i. The significance of increased total univalent cation concentration is discussed.

Animals↗
PubMed1980

Effect of ouabain on growth regulation by serum components in Balb/c-3T3 cells: inhibition of entry into S phase by decreased protein synthesis.

The effect of inhibition of the cell membrane Na+-K+ pump on the Balb/c-3T3 cell growth cycle was studied. Inhibition of the Na+-K+ pump resulted in a dose-dependent reduction of intracellular K+ concentration ((K+)i). However, inhibition of protein synthesis in Go/G1 and of subsequent entry into S phase occurred only after (K+)i fell below a critical threshold (50-60 mmoles/liter). Thus, when the (K+)i falls below a critical threshold, protein synthesis is inhibited, preventing cells from entering the S phase. The platelet-derived growth factor (PDGF) induces cells to become "competent" to traverse the cell cycle; the platelet-poor plasma component of serum allows competent cells to progress through G0/G1 and enter S phase. Inhibition of the Na+-K+ pump did not prevent the induction of competence by PDGF, but it did reversibly inhibit plasma-mediated events in early G0/G1. Similarly, cycloheximide inhibited plasma-mediated events but did not prevent PDGF-induced competence. Thus, protein synthesis may not be required for induction of competence; alternatively, the induction of the competent state may occur in these cells after removal of PDGF and protein synthesis inhibitor. Protein synthesis is required for subsequent plasma-mediated events in G0/G1.

Amino Acids↗