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Biomedical subjects

R N Moore

Publications and source records attributed to R N Moore.

At least 73 records · Page 4Linked to original sources
PubMed1985

Changes in leukocyte populations in pulmonary lavage fluids of calves after inhalation of Pasteurella haemolytica.

The distribution of leukocytes in bovine bronchoalveolar lavage fluids was determined in 15 calves at various times after aerosol exposure to Pasteurella haemolytica. For comparison, 10 calves were exposed to aerosols of phosphate-buffered saline solution; 15 calves, to Staphylococcus epidermidis; and 10 calves, to Salmonella typhimurium endotoxin. At 10 minutes after inhalation exposure for each group, the predominant cell type was the macrophage. Macrophages remained the predominant cell type throughout each lavage interval for calves exposed to phosphate-buffered saline solution and Staph epidermidis. For calves exposed to P haemolytica, there was a decrease in the percentage of macrophages detectable by 30 minutes after exposure, with a corresponding increase in the percentage of neutrophils. Sixty minutes after the inhalation exposure to P haemolytica, the percentages of macrophages and neutrophils in the lavage fluid were equal. By 240 minutes after exposure to P haemolytica, greater than 90% of the cells in the lavage fluids was neutrophils. The increase in the percentage of neutrophils in lavage fluids from calves exposed to S typhimurium endotoxin was similar to that seen for the calves exposed to P haemolytica.

Animals↗
PubMed1985

Antileukotoxin antibody produced in the bovine lung after aerosol exposure to viable Pasteurella haemolytica.

Experiments were performed to determine the in vivo immunogenicity of Pasteurella haemolytica leukotoxin. Calves were exposed twice to aerosol mists of viable P haemolytica, using a treatment regimen previously shown to induce a resistant state. Pulmonary lavage fluids and serum samples from these calves were assayed for leukotoxin-neutralizing antibodies. Before aerosol exposure, neutralizing antibody titers were routinely found in serum samples, but were not detectable in pulmonary lavage concentrates before exposure. After aerosol exposure, titers of toxin-neutralizing immunoglobulin (Ig)A and IgG antibodies were found in pulmonary lavage concentrates and were accompanied by increased serum toxin neutralization titers.

Aerosols↗
PubMed1984

Endogenous regulation of macrophage proliferative expansion by colony-stimulating factor-induced interferon.

Stimulation of cultures of murine bone-marrow cells with specific macrophage growth factor (colony-stimulating factor I) resulted in the production of type I interferon. Neutralization of this endogenous interferon by antiserum directed against interferons alpha and beta resulted in a significant enhancement of mononuclear phagocyte proliferation from committed marrow precursors. The effect of the antiserum was lost in cultures depleted of adherent cells, an indication that an adherent regulatory cell (or cells) in the marrow limits mononuclear phagocyte proliferation by producing antiproliferative interferon in response to high levels of specific growth factor.

Animals↗
PubMed1984

Role of T-lymphocyte subsets in recovery from herpes simplex virus infection.

Our investigations probed the nature of different T-lymphocyte subsets effecting clearance of herpes simplex virus after infection of the pinna. Cell populations from animals recently infected subcutaneously or intraperitoneally (acute population) or from animals infected 6 weeks previously (primed population) or the latter cells reimmunized in vitro with virus (memory population) were studied. Viral clearance was a function of the Lyt 1+2- subset in the acute population, but with the memory population both Lyt 1+ and Lyt 2+ cells affected clearance. In primed populations, viral clearance was effected only by the Lyt 2+ subset. The ability of the various cell populations to adoptively transfer delayed-type hypersensitivity was also studied. Only acute population cells from animals infected subcutaneously and memory population cells transferred delayed-type hypersensitivity. In both cases, the cell subtype was Lyt 1+2-. Our results demonstrated that the delayed-type hypersensitivity response does not always correlate with immunity to herpes simplex virus. Multiple subsets of T cells participate in viral clearance, and their respective importances vary according to the stage of the virus-host interaction.

Animals↗
PubMed1984

Reallocation in academic dentistry: a legal and administrative perspective.

Like other elements in higher education, academic dentistry is experiencing financial austerity and must be able to reallocate its resources in order to provide the optimal level of service within a given budget. Continuous, across-the-board budget cuts will only reduce the quality of strong departments to the level of weak ones. Dental college faculty, with guidance and support from administrators, will need to develop procedures and criteria for program restructuring that will increase educational flexibility and link budgeting with planning. Seniority and tenure may be used as criteria for personnel action, but faculty must be aware that tenure is a method to achieve academic freedom and is not a guarantee of perpetual employment. The courts will not substitute their judgment for that of the university authorities in academic or personnel matters unless the institution's action is arbitrary, capricious, or discriminatory.

Budgets↗
PubMed1983

Enhanced responsiveness of committed macrophage precursors to macrophage-type colony-stimulating factor (CSF-1) induced in vitro by interferons alpha + beta 1.

Contrasting effects of interferon alpha + beta (IFN) on colony-stimulating factor- (CSF) induced macrophage stem cell proliferation resulted when nucleated murine femoral marrow cells were exposed to IFN either before addition of CSF or simultaneously with CSF. Responsiveness to macrophage type L cell CSF was measured by two different assays: by determination of [3H]thymidine (3H-TdR) incorporation and by enumeration of colonies formed in response to CSF. Incubation of nucleated marrow cells concurrently with CSF and IFN resulted in depressed proliferation that was dependent on the dose of IFN. Preincubation of marrow cells with IFN, however, produced a dose-dependent enhancement of CSF responsiveness in comparison to preincubation of marrow cells in the absence of IFN. The enhancing effect of IFN was observed only when preincubated cells were stimulated with suboptimal concentrations of CSF. At optimal CSF concentrations, differences were not observed in either 3H-TdR incorporation or in colony formation. On the basis of data accumulated by both assays for CSF responsiveness, IFN pretreatment was hypothesized not to increase the total population of existing progenitor cells, but to influence the capacity of pre-existing progenitor cells to respond to suboptimal doses of the growth factor.

Animals↗
PubMed1982

Regulation of murine macrophage Ia antigen expression by a lymphokine with immune interferon activity.

A culture supernatant of concanavalin A-activated spleen cells (Con A supernatant) induced murine macrophages to express Ia antigens in vitro. Biochemical characterization of the Con A supernatant indicated that the macrophage Ia antigen regulatory activity shares molecular weight, pI, and hydrophobic and affinity characteristics with immune interferon (IFN-gamma). Antiserum to mouse IFN-gamma neutralized both the macrophage Ia antigen regulatory and IFN-gamma bioactivities of the Con A supernatant. Furthermore, both partially purified murine IFN-gamma (10(7) U/mg protein sp act) and IFN-containing culture supernatants of the murine BFS T cell line-induced macrophage Ia antigen expression in vitro. Culture supernatants containing colony-stimulating factor, interleukin 1, interleukin 2, macrophage migration inhibitory factor, and a macrophage-activating activity that were distinct from IFN-gamma did not induce macrophage Ia antigen expression. Taken together, the data indicate that the in vitro expression of Ia antigens on macrophages is regulated by an activity that has the characteristics of interferon.

Animals↗
PubMed1982

Regulation of macrophage accessory functions by interactions involving lymphokines and endotoxin.

It is important to reemphasize the observation that two distinct regulatory molecules, colony-stimulating factor (CSF) and interferon, can directly influence macrophage accessory functions. CSF stimulates macrophages to secrete interleukin 1 (IL 1) whereas interferon induces a conversion to Ia antigen expression. Either directly or indirectly these functions can also be influenced by a combination of lymphokines and bacterial lipopolysaccharides (LPS). As is the case with effector functions, it is apparent that specific regulatory molecules exist which function to amplify the influence of microbial products on macrophage accessory activities.

Animals↗
PubMed1982

Correction of defective macrophage differentiation in C3H/HeJ mice by an interferon-like molecule.

C3H/HeJ mice possess macrophages that lose the capacity to bind and phagocytose opsonized sheep erythrocytes (EA) when cultured. This defect in Fc receptor capacity is completely overcome by treatment of macrophage monolayers with extremely low concentrations of a lymphokine-rich, Con A-stimulated spleen cells supernatant. In this study we have pursued a biochemical and functional analysis of the lymphokine-rich supernatant to determine the nature of the specific factor responsible for the restoration of Fc receptor function. The chromatographic behavior and physical properties, its co-elution with anti-viral activity through a sequential purification scheme, the parallel activity of purified beta-interferon in enhancing both the binding and phagocytosis of EA, and the abrogation of factor-induced Fc-mediated phagocytosis with anti-Type II interferon antiserum, strongly support the hypothesis that the active factor is gamma- (Type II or immune) interferon (IFN). These studies suggest gamma-IFN may act as a differentiative signal to the macrophage by facilitating enhanced expression of macrophage surface membrane components.

Animals↗
PubMed1981

Functional regulator therapy for cleft palate patients.

Nine cleft lip and palate children exhibiting collapse of maxillary segments and cross-bite were treated orthodontically with the functional regulator (FR) for periods ranging from 6 to 18 months. The purpose of this investigation was to evaluate quantitatively treatment of cleft palate patients with the functional regulator and to evaluate the effect of the appliance on their speech. Cleft palate patients typically have speech, nose, and lip defects which make patient cooperation and appliance acceptance more difficult. However, patient cooperation was considered good with an average mean of 12.7 hours per day of appliance wear and a range of 5.6 to 18.2 hours. Change in interimplant dimension was measured on frontal radiographs, and dental changes were measured of serial dental casts. The resulting data indicated no significant change in maxillary width or cross-bite relationship. The functional regulator was not clinically useful in this sample when the treatment objective was primary expansion of collapsed maxillary segments in the cleft palate patient. Good speech-production skills prior to treatment will minimize the adverse effect that the FR has on speech intelligibility. A significant amount of accommodation to the appliance occurs within 1 week after insertion, but maximum improvement in speech intelligibility occurs with full-time wear of the appliance for as many hours per day as possible.

Activator Appliances↗
PubMed1981

Biologic properties of chromatographically separated murine thymoma-derived Interleukin 2 and colony-stimulating factor.

Two growth factors, interleukin 2 (T cell growth factor) and colony-stimulating factor, are produced concomitantly by a murine EL-4 thymoma cell line after stimulation by phorbol myristate acetate. As shown elsewhere, these thymoma-derived factors appear to be biochemically and functionally indistinguishable from the interleukin 2 and colony-stimulating factor produced by mitogen-stimulated mouse spleen cells. Both factors co-elute during gel filtration with apparent m.w. in the range of 30,000, and both exhibit overlapping isoelectric point profiles between pH 4 and pH 5. Because we were unable to separate these 2 factors by methods based on either m.w. or charge, we have used phenyl-Sepharose chromatography, a method based on hydrophobic interactions, to completely separate murine interleukin 2 and colony-stimulating factor. In contrast with published reports, each of the separated factors exhibits unique biologic activities on lymphocytes and macrophages. Interleukin 2 provides help for antibody synthesis in the nude mouse, but neither enhances interferon production by macrophages nor stimulates macrophage growth. Colony-stimulating factor does not enhance antibody synthesis in the nude mouse but does enhance interferon production by macrophages and stimulate macrophage growth.

Animals↗
PubMed1981

Academic dismissal for clinical reasons: implications of the Horowitz case.

Dismissal of a student from the educational program of a school of dentistry has immeasurable impact on the student and results in considerable emotional trauma to the faculty and administration. The legalistic emphasis of today's society has resulted in an increasing amount of litigation subsequent to student dismissals. The U.S. Supreme Court's recent decision in the case of Ms. Charlotte Horowitz has provided helpful guidance regarding what is fair when considering student dismissal for clinical or academic reasons, or both. Inferences from this and related cases are drawn that can assist dental education administrators in developing sound dismissal procedures for the institutions they manage.

Clinical Competence↗
PubMed1980

Regulation of murine macrophage Ia-antigen expression by products of activated spleen cells.

This investigation examined the effects of mediators derived form activated spleen cells on macrophage Ia-antigen expression and function. Incubation of adherent thioglycollate-induced murine peritoneal macrophages(> 90% Ia-) with concanavalin A (Con A)-stimulated spleen cell supernate (Con A sup) resulted in a dose-dependent increase in the percentage of Ia-containing (Ia+) phagocytic cells, as detected by antiserum-and-complement-mediated cytotoxicity. The Ia-antigen expression of macrophages incubated with unstimulated spleen cell supernate supplemented with Con A (Control sup) declined. Pretreatment of the macrophages with anti-Ia and complement before addition of the Con A sup did not inhibit subsequent Ia-antigen expression, suggesting that Ia- macropohages were converted to Ia+ cells. These findings were not a result of adsorption of soluble Ia-antigen from the Con A sup, because Ia-antigen expression was detected by an antiserum specific for the haplotype of the macrophages but not that of the allogeneic spleen cells from which the supernate was prepared. Con A sup-cultured macrophages also stimulated the proliferation of allogeneic spleen cells significantly better than Control sup-cultured macrophages in the mixed leukocyte reaction (MLR). Pretreatment of Con A sup-cultured macrophages with anti-Ia and complement before addition of splenic responder cells abrogated their stimulatory capacity, indicating the Ia dependence of the MLR. We hypothesize that regulatory lymphokine(s) can induce both the expression of the Ia+ phenotype by macrophages and the functional capability to stimulate the MLR, and that macrophages lose these capabilities in the absence of such mediator(s).

Animals↗