11 results on '"D.C. Hooper"'
Search Results
2. The role of uric acid in protection against peroxynitrite-mediated pathology
- Author
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D.C. Hooper and G.S. Scott
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Purine ,Nitrates ,Superoxide ,Urate oxidase ,Vascular permeability ,Inflammation ,General Medicine ,Biology ,Pharmacology ,Monocytes ,Nitric oxide ,Uric Acid ,chemistry.chemical_compound ,Mice ,chemistry ,Immunology ,medicine ,Uric acid ,Animals ,Humans ,medicine.symptom ,Peroxynitrite - Abstract
Peroxynitrite, the product of the free radicals nitric oxide and superoxide, has been implicated in the pathogenesis of inflammatory CNS disorders. Uric acid, an effective scavenger of peroxynitrite, is a purine metabolite present at high levels in the serum of hominoids relative to lower-order animals due to the functional deletion of urate oxidase. Raising the normally low levels of uric acid in mice is therapeutic for experimental allergic encephalomyelitis, an animal model of multiple sclerosis. This therapeutic activity of uric acid is associated with the inhibition of peroxynitrite-induced tissue damage, blood-CNS barrier permeability changes, and CNS inflammation. Based on these findings we have concluded that peroxynitrite has an important role in promoting enhanced vascular permeability and inflammatory cell extravasation. We hypothesize that higher uric acid levels in hominoids evolved to protect against this process. more...
- Published
- 2001
Catalog
3. Borna Disease Virus and its Role in Neurobehavioral Diseases
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D.C Hooper and J Richt
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Cancer Research ,Infectious Diseases ,biology ,Virology ,Immunology ,Borna disease virus ,biology.organism_classification - Published
- 2004
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4. In vitro activation of bone marrow-derived T- and non-T-cell subsets by α-fetoprotein
- Author
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D.W. Hoskin, D.C. Hooper, Robert A. Murgita, and S. Hamel
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Male ,T-Lymphocytes ,T cell ,Immunology ,Population ,Receptors, Antigen, B-Cell ,Bone Marrow Cells ,Cell Separation ,Biology ,Lymphocyte Activation ,Mice ,Lectins ,medicine ,Animals ,Cytotoxic T cell ,Soybean agglutinin ,Receptor ,education ,education.field_of_study ,Embryonic stem cell ,Molecular biology ,digestive system diseases ,In vitro ,Phenotype ,medicine.anatomical_structure ,Antigens, Surface ,Mice, Inbred CBA ,Soybean Proteins ,Female ,alpha-Fetoproteins ,Bone marrow ,Plant Lectins - Abstract
α-Fetoprotein (AFP) is a major serum glycoprotein during embryonic and early postnatal life. A number of diverse biologic functions have been attributed to AFP, including osmotic and carrier function and immunosuppressive activity. In this study we demonstrate that AFP selectively stimulates in vitro proliferation of two distinct subsets of adult murine bone marrow cells. One population of AFP-reactive bone marrow cells expresses surface receptors for soybean agglutinin (SBA) lectin. SBA+ bone marrow cells are resistant to cytotoxic pretreatment with T-cell-specific antisera and are not retained on Ig-anti-Ig affinity columns. The absence of conventional T- and B-cell markers, coupled with the presence of SBA receptors, suggests that AFP-activated non-T bone marrow cells may belong to an immature set of B lymphocytes. A second population of AFP-responsive bone marrow cells expresses the Thy-1+ Lyt1+2− phenotype characteristic of conventional mature adult T helper cells. The potential physiological relevance of the mitogenic effects of AFP on bone marrow cells with respect to immunoregulatory processes in the fetal/newborn environments is discussed. more...
- Published
- 1985
- Full Text
- View/download PDF
5. Murine pregnancy-associated modulations in lymphocyte reactivity to mitogens: Identification of the cell populations affected
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W.D. Billington, D.C. Hooper, and D.H. Chantry
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Lipopolysaccharides ,medicine.medical_specialty ,Time Factors ,Lymphocyte ,T cell ,Immunology ,Mice, Inbred Strains ,Spleen ,Thymus Gland ,Lymphocyte Activation ,Mice ,Pregnancy ,Internal medicine ,Concanavalin A ,medicine ,Animals ,Antigens, Ly ,Immunology and Allergy ,Lymphocytes ,Phytohemagglutinins ,Lymph node ,biology ,Obstetrics and Gynecology ,T lymphocyte ,Lymphatic system ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Cell culture ,biology.protein ,Pregnancy, Animal ,Female ,Lymph Nodes - Abstract
Lymphocytes from the thymus, spleen and inguinal lymph nodes of syngeneically pregnant and non-pregnant mice were compared in their responsiveness to polyclonal stimulation by mitogen. Pregnancy-associated changes in mitogen reactivity were detected, on a cell-per-cell basis, in thymocytes (increased) and spleen cells (decreased) but not in lymph node cells. The hyperreactivity of thymocytes during pregnancy correlated with physiological involution of the thymus occurring through the selective loss of relatively immature, non-mitogen-reactive, Lyt 1+2+ cells. The remaining cells were found largely to be mature Lyt 1+2- T cells with the capacity to respond to mitogenic stimulation. It is most likely the relative increase in the proportion of these Lyt 1+2- cells that causes the hyper-responsiveness of thymocytes to mitogens observed during pregnancy. On the other hand, while spleen cells from pregnant animals gave lower responses to mitogens than those from control virgin females, isolated splenic T cells from the two groups proved equally reactive to T cell mitogens. This supports the contention that at least some aspects of immunity during pregnancy are down-regulated by inhibitory cells within the non-T cell compartment. The results demonstrate the importance of identifying the reactive cell population in studies on changes in lymphocyte responsiveness in pregnancy. more...
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- 1987
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6. Temperature effects on evoked potentials of hippocampal slices from euthermic chipmunks, hamsters and rats
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S.M. Martin, D.C. Hooper, and John M. Horowitz
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medicine.medical_specialty ,Physiology ,Central nervous system ,Hamster ,Rhinencephalon ,Hippocampal formation ,Hippocampus ,Biochemistry ,Cricetinae ,Hibernation ,biology.animal ,Internal medicine ,medicine ,Animals ,Hippocampus (mythology) ,Evoked potential ,Evoked Potentials ,Mesocricetus ,biology ,Pyramidal Cells ,Temperature ,Sciuridae ,Population spike ,Anatomy ,Rats ,Chipmunk ,Cold Temperature ,Muridae ,Endocrinology ,medicine.anatomical_structure ,Nerve Net ,General Agricultural and Biological Sciences ,Developmental Biology - Abstract
1. Neural activity was recorded in hippocampal slices from euthermic chipmunks, hamsters and rats. 2. While recording the evoked potentials, the temperature of the Ringer's solution bathing the slice was varied by controlling the temperature of an outer chamber jacketing the recording chamber. 3. The temperature just below that at which a population spike could be evoked, Tt, was 10.4 +/- 0.3 degrees C (mean +/- SEM) for chipmunk slices, 14.1 +/- 0.4 degrees C for rat slices and 14.8 +/- 0.4 degrees C for hamster slices. Tt was significantly lower in the chipmunk slices (P more...
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- 1985
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7. Case 27-1985
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Richard C. Cabot, Robert E. Scully, Eugene J. Mark, Betty U. McNeely, J.H. Maguire, and D.C. Hooper
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medicine.medical_specialty ,business.industry ,General surgery ,education ,medicine ,General Medicine ,Presentation (obstetrics) ,medicine.symptom ,Intensive care medicine ,business ,Rash ,humanities ,Summer vacation - Abstract
Presentation of Case A 38-year-old man was admitted to the hospital because of a rash and fever. He was in excellent health until three days earlier, when he began his summer vacation in a lakeside... more...
- Published
- 1985
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8. Regulation on murine T cell responses to autologous antigens by alpha-fetoprotein
- Author
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D.C. Hooper and Robert A. Murgita
- Subjects
Male ,Ontogeny ,Lymphocyte ,T cell ,T-Lymphocytes ,Immunology ,Dose-Response Relationship, Immunologic ,Spleen ,Endogeny ,Biology ,Mitomycins ,Mice ,medicine ,Animals ,Antigens ,Fetus ,Mice, Inbred BALB C ,In vitro ,Thymocyte ,Kinetics ,medicine.anatomical_structure ,Mice, Inbred CBA ,Female ,Rabbits ,alpha-Fetoproteins ,Lymphocyte Culture Test, Mixed - Abstract
Murine α-fetoprotein (AFP), a major component of fetal and newborn sera, was shown to exert potent immunosuppressive effects on autologous mixed lymphocyte reactions (AMLR) in vitro . Thus, the relatively vigorous proliferative response of newborn CBA/J thymocytes reacting in mixed cultures against adult syngeneic spleen cells was almost totally abrogated by 200 and 100 μg/ml AFP over the 6-day time course studied, with significant suppression still evident in the presence of 10 μg/ml AFP. In contrast, the maximum achievable suppression of parellel allogeneic MLRs was only 40 to 60%. The newborn thymocyte anti-adult syngeneic spleen AMLR was shown to be mediated by an Lyt 1 + 23 − T-cell subset reacting against Ia + adult non-T stimulator cells. Newborn and adult AMLRs resulting from autochthonous T responder/non-T stimulator cell mixtures from individual animals were also found to be highly sensitive to AFP-mediated suppression. The fact that fetal-derived AFP could be shown to efficiently inhibit neonatal thymocyte responses to autologous antigens when tested in vitro in amounts 20 to 50 times lower than the levels present in fetal and newborn sera suggests a potentially important role for endogenous AFP in the regulation of autosensitization during ontogeny. more...
- Published
- 1981
9. Murine T cells reactive against autologous erythrocytes: evidence for in vitro and in vivo priming with mouse and rat red blood cells
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R. B. Taylor, J.L. Young, Christopher J. Elson, and D.C. Hooper
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Male ,Erythrocytes ,T-Lymphocytes ,Immunology ,In Vitro Techniques ,Lymphocyte Activation ,Autoantigens ,Clonal deletion ,Interleukin 21 ,Mice ,Immune Tolerance ,Cytotoxic T cell ,Animals ,IL-2 receptor ,Interleukin 3 ,Autoantibodies ,CD40 ,biology ,hemic and immune systems ,Natural killer T cell ,Molecular biology ,Rats ,biology.protein ,Interleukin 12 ,Mice, Inbred CBA ,Female ,Immunization - Abstract
Normal mice are shown to harbor T cells that can be sensitized to proliferate against autologous red blood cells (RBC). These autoreactive cells were primed in vitro and in vivo with mouse as well as heterologous rat RBC, the in vivo administration of which has been previously shown to trigger the production of auto-RBC antibodies. Two broad classes of specificity are detected following priming: T cells cross-reactive for similar determinants coexpressed by mouse and rat RBC, and T cells specific for antigens restricted to self-RBC. These findings indicate that clonal deletion of self-RBC-reactive T cells is far from complete. The comparison of different in vitro and in vivo immunization protocols revealed the possible existence of several levels of immunoregulatory control which may prevent the expression of autoimmunity by these T cells. more...
- Published
- 1987
10. Altered immune response patterns in murine syngeneic pregnancy: presence of natural null suppressor cells in maternal spleen identifiable by monoclonal antibodies
- Author
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B.D. Reilly, K.-O. Gronvik, D.W. Hoskin, D.C. Hooper, and Robert A. Murgita
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medicine.drug_class ,T cell ,Immunology ,Spleen ,Receptors, Fc ,Biology ,Monoclonal antibody ,Lymphocyte Activation ,T-Lymphocytes, Regulatory ,Mice ,Immune system ,Antigen ,Pregnancy ,medicine ,Cytotoxic T cell ,Animals ,Cells, Cultured ,Mice, Inbred BALB C ,Cell growth ,Macrophages ,Antibodies, Monoclonal ,Molecular biology ,Receptors, Complement ,medicine.anatomical_structure ,Cell culture ,Receptors, Mitogen ,Mice, Inbred CBA ,Pregnancy, Animal ,Female ,Lymphocyte Culture Test, Mixed - Abstract
Expression of certain autologous lymphocyte-activating antigenic determinants on the developing embryo is known to provide a stimulus for maternal anti-fetal autoproliferative responses. If left unregulated these responses could exert negative influences on the reproductive process by converting to autoaggressive forms of immune reactivity. In normal circumstances, immunological reactions of this nature are therefore likely to be under the control of pregnancy-associated immunoregulatory elements found within the maternal/fetal environment. In the present investigation we describe a naturally occurring splenic inhibitory cell type devoid of conventional T, B, and macrophage surface markers associated with syngeneic murine pregnancy that is capable of exerting potent immunosuppressive effects on an in vitro expression of fetal/newborn T cell autoreactivity, namely the autologous mixed lymphocyte reaction (AMLR). Maternal spleen cells inhibitory for AMLR were found to be highly resistant to cytotoxic pretreatment with a panel of conventional antisera directed against T cell-specific antigenic determinants. The non-T nature of the natural splenic suppressor cell was further indicated by experiments showing that purified spleen T cells had no inhibitory activity. Pregnancy spleen cell populations that were effectively depleted of macrophages retained full ability to inhibit AMLR. Maternal suppressor activity could be localized to the spleen cell population bearing receptors for the B cell-specific lectin, soybean agglutinin (SBA). A panel of monoclonal antibodies prepared against enriched populations of suppressor cells was screened and selected for specific reactivity using an ELISA against glutaraldehyde-fixed SBA+ spleen cell subpopulations from pregnant versus virgin animals. Several of the monoclonals developed against suppressor-enriched spleen cell populations from isopregnant as well as allopregnant animals were effective in reducing or eliminating suppressor cell activity following cytotoxic pretreatment in the presence of complement. The novel set of anti-suppressor monoclonal antibodies described here should prove useful in furthering the isolation and characterization of pregnancy-associated suppressor cells and in determining their relationship to natural suppressor cell populations described in other systems. more...
- Published
- 1989
11. Murine neonatal spleen contains natural T and non-T suppressor cells capable of inhibiting adult alloreactive and newborn autoreactive T-cell proliferation
- Author
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K.-O. Gronvik, D.W. Hoskin, Robert A. Murgita, and D.C. Hooper
- Subjects
T cell ,T-Lymphocytes ,Immunology ,Biology ,Lymphocyte Activation ,T-Lymphocytes, Regulatory ,Mice ,Immune system ,Antigen ,Lectins ,medicine ,Cytotoxic T cell ,Animals ,IL-2 receptor ,Mice, Inbred BALB C ,Macrophages ,T lymphocyte ,Cell biology ,medicine.anatomical_structure ,Animals, Newborn ,biology.protein ,Myeloid-derived Suppressor Cell ,Mice, Inbred CBA ,Soybean Proteins ,Antibody ,Lymphocyte Culture Test, Mixed ,Plant Lectins ,Spleen - Abstract
The spleen of neonatal mice is known to be a rich source of cells capable of suppressing a variety of immune functions of adult lymphocytes in vitro. From such observations has emerged the concept that the gradual development in ability to express immune functions after birth is due in part to the parallel normal physiological decay of naturally occurring regulatory suppressor cells. There is, however, some confusion in the literature as to the exact nature of the newborn of the newborn inhibitory cell type(s). In contrast to most previous reports which detect only a single type of neonatal suppressor cell, usually a T cell, we show here that newborn spleen harbors both T and non-T inhibitory cells. Both types of suppressor cells could be shown to suppress the proliferative response of adult spleen to alloantigens as well as newborn T cells reacting against self-Ia antigen in the autologous mixed lymphocyte reaction (AMLR). Newborn suppressor T cells were characterized as being non-adherent to Ig-anti-Ig affinity columns, soybean agglutinin receptor negative (SBA-), and susceptible to lysis by anti-T-cell specific antiserum plus complement. Non-T suppressor cells were identified as non-phagocytic, SBA receptor positive (SBA+), and resistant to cytotoxic treatment with anti-T-cell antibodies and complement. The apparent controversy surrounding previous reports as to the T versus non-T nature of newborn suppressor cells can be reconciled by the present observation that both types of inhibitory cells coexist in the spleen. Furthermore, the demonstration that newborn suppressor cells can effectively regulate T-cell proliferative activity mediated by other newborn cells provides more direct support for the contention that such inhibitory cells play a physiological role in controlling immune responsiveness during early ontogeny. more...
- Published
- 1986
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