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Biomedical subjects

P Furmanski

Publications and source records attributed to P Furmanski.

At least 55 records · Page 3Linked to original sources
PubMed1989

Multiple molecular forms of human lactoferrin. Identification of a class of lactoferrins that possess ribonuclease activity and lack iron-binding capacity.

Lactoferrin (Lf), the major iron-binding component of milk, also a major constituent of the specific granules of neutrophils involved in antimicrobial activity and a glycoprotein thought to play a role in regulatory functions in the hematopoietic system as well as other physiologic activities, is shown to occur in three isoforms. One, Lf-alpha, binds iron; the other two, Lf-beta and Lf-gamma, express potent RNase activity, but do not bind iron. The three isoforms are very similar or identical in Mr, pI, partial proteolytic peptide patterns, NH2-terminal amino acid sequence, and reactivity with mAbs and polyclonal antisera against the RNase and Lf, respectively. The finding of structurally similar but enzymatically distinct forms of Lf may be related to the diverse functions of the molecule.

Antibodies, Monoclonal↗
PubMed1989

In vivo hematopoietic effects of recombinant interleukin-1 alpha in mice: stimulation of granulocytic, monocytic, megakaryocytic, and early erythroid progenitors, suppression of late-stage erythropoiesis, and reversal of erythroid suppression with erythropoietin.

Interleukin-1 alpha (IL-1 alpha) is a macrophage-derived, multifunctional cytokine that broadly potentiates myelopoiesis and induces the synthesis of hematopoietic colony-stimulating factors (CSF) in vitro and in vivo. To evaluate the possibility for use of IL-1 alpha in ameliorating in vivo bone marrow suppression induced by drugs or radiation, we examined the in vivo effects of the cytokine on erythropoietic and other hematopoietic progenitor cells. Normal mice were treated with a single intraperitoneal (IP) injection of recombinant human IL-1 alpha at varying doses and were assayed at various times post-treatment. By six hours postinjection, a significant suppression of mature erythroid progenitors (CFU-E) was observed in animals treated with IL-1 alpha (0.5 micrograms/mouse), with maximum suppression of CFU-E and peripheral blood reticulocyte counts occurring at 24 hours. Decreases in peripheral blood hematocrit did not occur after a single IL-1 alpha injection but were observed after multiple injections of the cytokine. The suppressive effects of IL-1 alpha on late-stage erythropoiesis were abrogated by simultaneous administration of erythropoietin (EPO). At 48 hours post-treatment, a marked stimulation was observed in the numbers of spleen and marrow immature erythroid (BFU-E), macrophage (CFU-M), granulocyte (CFU-G), granulocyte-macrophage (CFU-GM), and megakaryocyte (CFU-meg) progenitor cells. These results demonstrate the potential use of IL-1 alpha as a generalized stimulator of hematopoiesis and show that the cytokine-induced suppression of late-stage erythropoiesis can be prevented by EPO.

Animals↗
PubMed1989

Effects of inhibitors and activators of protein kinase C on late erythroid progenitor (CFU-e) colony formation in vitro.

Protein kinase C (PKC) plays a central role in external signal transduction for many cell types. To examine the involvement of PKC in the control of erythropoiesis, we tested the effects of PKC inhibitors on in vitro colony formation by late erythroid progenitors (CFU-e) from normal and Friend virus-infected mice. Inhibitors of PKC and other kinases (H-7 and H-8) inhibited CFU-e at concentrations which inhibit PKC. HA1004, an inhibitor of the cyclic nucleotide-dependent kinases and a weak inhibitor of PKC, had little effect on CFU-e. In the absence of erythropoietin, a combination of phorbol ester and Ca++ ionophore significantly increased normal CFU-e. These results suggest PKC plays a role in the transduction of regulatory signals for the growth of CFU-e.

Animals↗
PubMed1989

Lymphokine-activated killer cell plus recombinant interleukin-2 therapy of erythroleukemia in mice.

The antileukemic effects of lymphokine-activated killer (LAK) cells plus recombinant interleukin-2 (rIL-2) therapy were assessed in mice with Friend virus (FV)-induced erythroleukemia. LAK cells were generated by incubating normal spleen cells for 72 hr in the presence of rIL-2 (1000 units/ml). At the time of injection, the LAK cells were cytotoxic in vitro against FV-infected fibroblasts and NK-sensitive and -resistant tumor targets but not normal controls. To determine in vivo activity, fully leukemic mice (spleen weight greater than 0.75 g) were injected with either PBS or LAK cells (10(8) cells/mouse IV at 14 and 17 days post virus) and rIL-2 (10,000 units/mouse IP every 8 hr on days 14 through 18 post virus). More than 70% of the progressively leukemic mice experienced permanent leukemia regressions (disease-free for greater than 100 days) following LAK cell plus rIL-2 therapy. Regressions were characterized by return of spleen and liver weights to normal and elimination of virus-infected erythroid (CFU-E) and macrophage (CFU-C) progenitor cells from spleen and marrow. Leukemic animals treated with either LAK cells alone or IL-2 alone experienced only transient leukemia regressions. These results demonstrate that LAK cell plus rIL-2 treatment can induce permanent regressions in progressively leukemic mice and provide a responsive and manipulable model system to elucidate the mechanisms involved in this form of immunotherapy.

Animals↗
PubMed1988

Antitumor effects of recombinant human interleukin 1 alpha in RIF-1 and Panc02 solid tumors.

The antitumor effects of recombinant human interleukin 1 alpha (IL-1) were determined in RIF-1 and Panc02 murine solid tumors. Acute tumor hemorrhage was observed in both models as early as 3 h after a single 25 micrograms/kg IL-1 treatment and was quantitated by the intratumor accumulation of 59Fe-labeled erythrocytes (RBC). The IL-1-mediated hemorrhagic response was maximal 6-12 h after treatment and greater in Panc02 tumors than in RIF-1 tumors. Hemorrhagic responses to RIF-1 tumors growing in athymic nude mice were similar to those seen for RIF-1 tumors in C3H/HeJ mice. This acute vascular injury was accompanied by progressive edema in tumors but not in skin or muscle. In RIF-1 tumors, the extracell water volume at 12 h after IL-1 (395 microI/g) was nearly twice that in untreated controls (215 microI/g). IL-1 also produced marked reductions in tumor blood flow as early as 1 h after treatment. Maximal blood flow restriction was seen at 6 h after IL-1. Although restricted blood flow was observed in tumors for up to 48 h, IL-1 effects on muscle, liver, and skin blood flow were transient with recovery by 12 h after treatment. IL-1 (up to 0.4 ng/ml for 72 h) was not toxic to RIF-1 tissue culture cells in vitro, but 0.2 ng/ml IL-1, for 20 h, reduced the clonogenicity of RIF-1 cells in primary explant cultures by approximately 50%. In vivo, the clonogenic cellularity of RIF-1 tumors was reduced by 70%, 24 h after a single 25 micrograms/kg treatment. Increased clonogenic cell proliferation was observed at 24 h, and rapid repopulation of the clonogenic cell population was seen by 48 h. Although IL-1 transiently slowed the growth of RIF-1 tumors, no significant regrowth delay was observed. In Panc02 tumors, cell proliferation was also inhibited after IL-1. Recovery, however, was delayed and occurred more slowly than in RIF-1 tumors. Significant growth inhibition and regrowth delay (5 days) was observed in Panc02 tumors after a single IL-1 treatment. The results of these studies show that IL-1 has significant effects on the pathophysiology of both RIF-1 and Panc02 tumors in vivo. Further, our results indicate that these effects may be mediated through the activation of a non T-cell, adherent cell population residing in the tumor at the time of IL-1 treatment.

Animals↗
PubMed1988

Metalloporphyrin enhancement of magnetic resonance imaging of human tumor xenografts in nude mice.

Paramagnetic metalloporphyrins were examined for their in vivo bio-distribution and their ability to enhance nuclear magnetic resonance imaging of human tumor xenografts in nude mice. The metalloporphyrins tested were: manganese tetrasodium-meso-tetra(4-sulfonatophenyl)-porphine (MnTPPS); manganese meso-tetra-4-pyridylporphine; and gadolinium meso-tetra-4-pyridylporphine. All exhibited high molar relaxivities in aqueous solution. In vivo, at a dose of 2 mg/mouse, MnTPPS depressed the longitudinal relaxation time, T1, significantly in the kidney and less in lung and blood. Manganese meso-tetra-4-pyridylporphine depressed T1 in the kidney, lung and liver, while gadolinium meso-tetra-4-pyridylporphine caused large T1 depressions in the blood, liver, brain and tumor, probably due to dissociation of the metalloporphyrin and binding of Gd to plasma or tissue proteins. At a dose of 10 mg/mouse, MnTPPS caused marked T1 depressions of all tissues tested within 5 min of inoculation, but 48-72 h later, T1 values of normal tissues had returned to near normal, while those of the tumors remained significantly depressed. MnTPPS was able to significantly enhance the intensity of nuclear magnetic resonance images of MX-1 and ZR-75 human breast tumors and CX-1 and LS174T human colon tumor xenografts in nude mice. The results demonstrate that paramagnetic metalloporphyrins, because of their high relaxivities and retention in tumors, have the potential for use as tumor-selective contrast agents for nuclear magnetic resonance imaging.

Animals↗
PubMed1988

In vivo hematopoietic effects of tumor necrosis factor-alpha in normal and erythroleukemic mice: characterization and therapeutic applications.

The effects of recombinant, macrophage-derived, murine tumor necrosis factor-alpha (TNF-alpha) on hematopoiesis in vivo has been examined in normal mice and in Friend virus (FV)-induced erythroleukemic mice. Intravenous (IV) administration of a single dose of recombinant murine TNF-alpha (10(5) U per mouse) significantly suppressed normal and leukemic late-stage erythropoiesis as measured by numbers of mature erythroid colony forming cells (CFU-E) in the bone marrow and spleen and by peripheral blood reticulocyte counts. In normal animals, the immature erythroid (BFU-E), macrophage (CFU-M), and granulocyte-macrophage (CFU-GM) compartments were significantly stimulated by TNF-alpha in both the bone marrow and the spleen. In the bone marrow of leukemic mice, the BFU-E, CFU-GM, and CFU-M progenitor cell compartments were also stimulated by treatment with the monokine. In the spleens of leukemic mice (the primary site of FV leukemia cell accumulation), relative numbers of BFU-E and CFU-GM were increased by TNF-alpha, while those of CFU-M were suppressed. TNF-alpha caused a rapid decrease in the markedly elevated spleen weights of progressively leukemic mice, and in multiple doses it caused complete clinical disease regression in a significant percentage of leukemic animals. The combination of TNF-alpha with interferon-gamma (IFN-gamma) increased the incidence of leukemia regression, compared with TNF-alpha alone. These results show that TNF-alpha exerts a suppressive influence on late-stage erythropoiesis in vivo and suggest that this effect might be exploited in the treatment of acute erythroleukemia, erythroid hyperplasias, and related diseases.

Animals↗
PubMed1987

A rapid and efficient method for testing immunohistochemical reactivity of monoclonal antibodies against multiple tissue samples simultaneously.

A flexible, efficient and rapid method was developed whereby a small volume of monoclonal antibody could be used to immunohistochemically stain many different tissues, simultaneously, on one standard glass slide. This method is based on the preparation of 'cores' of paraffin-embedded tissue from standard histology blocks. The paraffin cores are straightened, inserted into a casing cut from an ordinary drinking straw, mounted in a paraffin block and sectioned. Over 120 individual tissue samples can be organized on a slide and stained for screening or characterization with 0.25 ml of diluted primary antibody. Advantages of this paraffin core method include: great economies in time, reagents, tissue specimens and antibodies; ease of producing multiple, regular, stable, easily handled tissue core samples; direct identification of intratissue regions of interest for inclusion; efficient use of rare tissue samples; versatility for rapid construction of multiple tissue slides containing any combination of relevant tissues from a 'library' of tissue cores; and, no need for deparaffinization and reembedding of tissues.

Animals↗
PubMed1986

High-level conjugation of chelating agents onto immunoglobulins: use of an intermediary poly(L-lysine)-diethylenetriaminepentaacetic acid carrier.

Diethylenetriaminepentaacetic acid (DTPA), a strong chelating agent, was covalently linked to murine monoclonal anti-HLA IgG1 antibody (H-1) with the use of poly(L-lysine) (Mr 14,000) as a multivalent, intermediary carrier, via thiol-disulfide exchange reaction. The conjugates contained up to 42.5 mol DTPA per mol antibody, and retained over 90% of their antibody activity in vitro. The conjugates incorporated gadolinium (Gd) through an exchange reaction with Gd-EDTA, used to prevent colloid formation and nonspecific binding of the free metal. The IgG-poly(L-lysine)-DTPA-Gd had a greater effect per mol on proton relaxation rates than DTPA-Gd itself. Use of poly(L-lysine) as an intermediary carrier for attachment of chelating agents to IgG thus offers great potential for achieving high-specific-activity conjugates, particularly for use as biologically specific contrast agents in nuclear magnetic resonance imaging.

Antibodies, Monoclonal↗
PubMed1986

The measurement of extracellular water volumes in tissues by gadolinium modification of 1H-NMR spin lattice (T1) relaxation.

The present studies were conducted in RIF-1, M5076 and Panc02 murine tumor models to compare extracellular water measurements made by 51Cr-EDTA dilution techniques and a new method which exploits the concentration dependent modification of 1H-NMR proton relaxation by Gadolinium-DTPA-dimethyl glucamine (Gd-DTPA-dimeg) in plasma and tissues. The time dependent changes in T1 modification in tissue and plasma were determined at various intervals after i.v. injection of 0.1 ml of 100 mM Gd-DTPA-dimeg and Gd concentrations determined from standard curves of Gd concentration dependent T1 modification of mouse plasma. Comparison of tissue and plasma Gd concentrations permitted the calculation of Gd-DTPA-dimeg distribution volumes. In unperturbed RIF-1, M5076 and Panc02 tumors, Gd-DTPA-dimeg distribution volumes determined by the T1 modification technique were similar to extracellular water spaces determined by 51Cr-EDTA dilution assays. In mouse liver, the 51Cr-EDTA assay resulted in artifactually high extracellular water space estimates due to internalization of the probe; Gd-DTPA-dimeg distribution volumes determined in liver with both the 153Gd-DTPA-dimeg and by the T1 modification method were approximately 150 ul/gram. The Gd-DTPA-dimeg T1 modification method also provided good approximations of changes in extracellular water volumes in RIF-1 tumors after dexamethasone and cyclophosphamide treatments. These results indicate that Gd-DTPA-dimeg modification of proton relaxation may be extremely useful for monitoring changes in tumor water dynamics during cancer therapy.

Animals↗
PubMed1986

1H-NMR relaxation times and water compartmentalization in experimental tumor models.

The present studies were conducted with RIF-1, M5076 and Panc02 subcutaneous tumor models to assess the relationship between tissue-free water compartmentalization and observed tissue T1 and T2 changes at 10 MHz. Observed T1 was shown to correlate directly with total extracellular water and interstitial water volumes. T1 and T2 were also inversely related to intracellular water volumes. T1 and T2 decreases after dexamethasone treatment were, however, most closely correlated with changes in tumor extracellular water and not changes in cell or total water volumes. Studies to assess Gd-DTPA-dimeg dose dependent T1 and T2 modification in model serum protein solutions indicated that although the Gd concentration that reduced T2 by 50% was about 2.5 fold greater than that required to reduce T1 equally, the of the concentration dependent T1 and T2 modifications were similar. In studies with tumor models, the injected dose of Gd-DTPA-dimeg that reduced T1 by 50% was inversely correlated with tumor extracellular water volumes. The slopes for dose dependent T1 modification in all tumors were similar and similar to that observed for model protein solutions. Gd-DTPA-dimeg had a different effect on observed T2 values for the 3 tumor models. Exponential slopes were about twice that observed for T2 modification of serum protein solutions, and Gd-DTPA-dimeg doses that reduced observed tumor T2 ranged from 9 to 50 times that necessary to similarly reduce T1. The results from these studies indicate that the observed T1, for these tumors, was dominated by relaxation of water protons in interstitial water but that the observed T2 was most strongly influenced by proton relaxation in water compartments that were unavailable to the Gd labeled probe.

Animals↗
PubMed1986

Infection of haematopoietic stem cells in mice with Friend virus induced erythroleukaemia.

Animals infected with conventional anaemia (FVA) or polycythemia-inducing (FVP) strains of the Friend virus develop lethal erythroleukaemia. A variant strain, RFV, induces an initially identical disease except that it spontaneously regresses in 50% of infected mice. To determine whether pluripotent stem cells as measured by spleen colony forming units (CFU-s) in leukaemic mice are productively infected with virus and whether their infection influences the outcome of the disease, we tested CFU-s from leukaemic mice for susceptibility to cytotoxicity by monospecific antiviral gp70 antiserum. Spleen CFU-s from progressively leukaemic (FVP, FVA and RFV) mice were productively infected with virus. CFU-s in RFV progressors became infected by 40 days post-virus inoculation. FVA and FVP progressors became infected between 15 and 21 days post virus. Infection of CFU-s was accompanied by an increase in the proportion of replicating (S phase) CFU-s in these populations. Spleen CFU-s from fully regressed RFV regressor mice were uninfected and remained so throughout the course of their disease. Bone marrow CFU-s in both regressors and progressors remained uninfected and were not induced to increased cell cycling.

Animals↗
PubMed1986

Induction of leukemia regression in mice by immunotherapeutic transfer of T-lymphocytes.

The erythroleukemia induced in susceptible mice by Friend virus (FV) is a progressive, lethal disease. A variant strain of Friend virus (regressing FV) produces a histopathologically identical leukemia except that the disease spontaneously regresses in 50% of leukemic mice. Normal T-cell and macrophage function are required for regression to occur and in animals that are going to regress, specifically reactive T-cells are found in the spleen. Passive transfer of sensitized T-cells from regressing FV immunized or regressed mice caused regression of the conventional lethal leukemia induced by FV. To expand the effector cell populations, characterize them and improve their therapeutic efficacy, sensitized T-cells were cultured in vitro. The T-cells, isolated from regressed or immunized mice, were grown and expanded in vitro with interleukin 2 and antigen (mitomycin C treated regressing FV-infected cell lines). The T-cells demonstrated high levels of in vitro cytotoxicity against FV antigens but exhibited no blastogenic response to the same antigens. When fully FV-induced leukemic mice (14 days post virus inoculation; spleen weight, greater than 0.75 g) were given one injection of 5 X 10(6) in vitro cultured T-cells and no other treatment the mice experienced permanent regressions of their disease. From T-cell cultures depleted of specific cell populations with monoclonal antisera, helper Lyt-1+ cells were shown to be responsible for permanent regressions (cures), whereas cytotoxic Lyt-2+ cells caused temporary leukemia remissions. This model thus provides an experimental system of highly effective passive cellular immunotherapy against an autochthonous, fully developed leukemia, requiring no adjunctive treatment for activity.

Animals↗
PubMed1986

Mechanism of macrophage reversal of Friend erythroleukemia: macrophage regulation of normal and leukemic erythropoiesis.

The acute erythroleukemia induced in mice by the anemia-inducing strain of the Friend virus complex is caused to regress by normal macrophages. We examined the possibility that reversal of leukemia is related to a macrophage regulatory function in erythropoiesis. We found that the ability of macrophages to induce leukemia regression correlates with nonimmunological, in vivo suppression of normal and susceptible leukemic erythroid progenitors. The macrophage effect on erythropoiesis appears to be due to changes in a humoral regulator, related to but independent of erythropoietin. The results suggest a novel regulatory system for erythropoiesis, operative in vivo, and involving macrophages as accessory or suppressor cells. This regulation appears to be disrupted in erythroleukemic mice, but can be restored, and the disease can be made to regress by treatment with normal macrophages.

Animals↗
PubMed1984

Inhibition of CFU-E colony formation by resident peritoneal macrophages from hybrids of BALB/c mice.

In previous studies, macrophages have been shown to influence in vitro colony formation by erythroid progenitors (CFU-E). To determine whether the origin of the macrophages influences their effects on in vitro erythropoiesis, plasma clot cultures of CFU-E were grown over adherent monolayers of macrophages from various strains of mice. Macrophages were separated from the plasma clot cultures by an intermediary layer of agar. Normal resident macrophages from BALB/c mice and several other inbred strains had no effect on CFU-E colony formation. In contrast, macrophages from a strain of mice termed BWF, which were originally identified as BALB/c but subsequently shown to be a hybrid of BALB/c and outbred CFW mice, strongly inhibited erythroid colony formation. Resident macrophages from the parental outbred CFW mice inhibited CFU-E in 50% of the animals tested. Inhibition was obtained in both homologous and autologous macrophage-CFU-E combinations and was therefore not due to histoincompatibility effects, nor was inhibition related to prostaglandin production by the macrophages or to effects on erythropoietin levels in the assay system. The results demonstrate that normal resident macrophages influence in vitro erythropoiesis and that the effects observed are dependent on the genotype of the mice from which the cells are derived.

Animals↗
PubMed1984

Stimulation of normal erythropoiesis in vitro by macrophages from erythroleukemic mice.

The erythroleukemia induced in mice by the Friend virus complex is caused to regress by macrophages. To determine whether the effect of macrophages on leukemia is due to their role in the regulation of erythropoiesis, investigators examined the influence of macrophages from normal and leukemic mice on in vitro colony formation by erythroid progenitor cells [colony-forming units of erythroid progenitor cells (CFU-E)]. Plasma clot cultures of CFU-E were grown over monolayers of macrophages separated from the CFU-E cultures by a layer of agar. Macrophages from progressors (those leukemic mice that will not undergo leukemia regression) significantly stimulated CFU-E, whereas macrophages from regressors (those that will undergo leukemia regression) had no effect on colony formation. Monolayers of normal resident macrophages did not affect in vitro erythropoiesis, while less mature macrophages (peripheral blood mononuclear cells) or nonspecifically activated macrophages (exudate induced) in monolayer stimulated CFU-E. Stimulation by macrophages from leukemic mice was dependent on the presence of virus-producing cells. CFU-E from erythroleukemic mice were resistant to stimulation by leukemic macrophages. These results demonstrated that macrophages from progressively leukemic mice influenced normal colony formation of CFU-E in vitro and that these effects could be related to the ability of macrophages to cause leukemia regression.

Animals↗