Search PubMed⌕ Search

Biomedical subjects

M A Moore

Publications and source records attributed to M A Moore.

At least 343 records · Page 19Linked to original sources
PubMed1985

Effects of in vitro purging with 4-hydroperoxycyclophosphamide on the hematopoietic and microenvironmental elements of human bone marrow.

UNLABELLED: We describe the effects of 4-hydroperoxycyclophosphamide (4-HC) on the hematopoietic and stromal elements of human bone marrow. Marrow cells were exposed to 4-HC and then assayed for mixed (CFU-Mix), erythroid (BFU-E), granulomonocytic (CFU-GM), and marrow fibroblast (CFU-F) colony-forming cells and studied in the long-term marrow culture (LTMC) system. The inhibition of colony formation by 4-HC was dose and cell-concentration dependent. The cell most sensitive to 4-HC was CFU-Mix (ID50 31 mumol/L) followed by BFU-E (ID50 41 mumol/L), CFU-GM (ID50 89 mumol/L), and CFU-F (ID50 235 mumol/L). In LTMC, a dose-related inhibition of CFU-GM production was noted. Marrows treated with 300 mumol/L 4-HC were completely depleted of CFU-GM but were able to generate these progenitors in LTMC. Marrow stromal progenitors giving rise to stromal layers in LTMC, although less sensitive to 4-HC cytotoxicity, were damaged by 4-HC also in a dose-related manner. Marrows treated with 4-HC up to 300 mumol/L, gave rise to stromal layers composed of fibroblasts, endothelial cells, adipocytes, and macrophages. Cocultivation experiments with freshly isolated autologous hematopoietic cells showed that stromal layers derived from 4-HC-treated marrows were capable of sustaining the long-term production of CFU-GM as well as controls. IN CONCLUSION: (1) Hematopoietic progenitors cells, CFU-Mix, BFU-E, and CFU-GM, are highly sensitive to 4-HC, whereas marrow stromal progenitor cells are relatively resistant. (2) Marrows treated with 300 mumol/L 4-HC that are depleted of CFU-Mix, BFU-E, and CFU-GM can generate CFU-GM in LTMC, suggesting that most primitive hematopoietic stem cells (not represented by CFU-Mix) are spared by 4-HC up to this dose. (3) Consequently, the above colony assays are not suitable tools for predicting pluripotent stem cell survival after 4-HC treatment in vitro.

Bone Marrow↗
PubMed1984

Interleukin 2 regulates the expression of Tac antigen on peripheral blood T lymphocytes.

We investigated the effect of OKT3 antibody and interleukin 2 (IL-2) on Tac antigen expression and the proliferation of human peripheral blood mononuclear leukocytes. OKT3 monoclonal antibody at low, nonmitogenic concentrations (25 pg/ml) or IL-2 alone at optimal concentrations (20 U/ml) did not induce IL-2 receptor expression, as measured by Tac antibody or by T cell proliferation. However, costimulation with these concentrations of OKT3 antibody and IL-2 led to Tac antigen expression and T cell proliferation. These data suggest that the T cells are activated in two steps: OKT3 antibody at 25 pg/ml does not induce Tac antigen expression, but preactivates T cells to become responsive to IL-2. The addition of exogenous IL-2 then leads to expression of the IL-2 receptor, as recognized by Tac antibody, and to subsequent proliferation.

Antibodies, Monoclonal↗
PubMed1984

Isolation of the covalent binary complex of 5-fluorodeoxyuridylate and thymidylate synthetase by trichloroacetic acid precipitation.

Strong chemical evidence for the existence of a covalent binary complex between 5-fluorodeoxyuridylate and thymidylate synthetase was provided by the isolation of the complex by trichloroacetic acid precipitation. This result together with that of a control experiment with N-ethymaleimide inactivated thymidylate synthetase demonstrated that only nucleotide covalently bound to the protein survived repeated washings of the precipitate. Under the conditions used, a maximum binding stoichiometry of about 0.9 was obtained for the covalent binary complex, Kd = 1.1 X 10(-5) M. Also, a binding ratio of 1.7 was obtained for the methylenetetrahydrofolate-5-fluorodeoxyuridylate-thymidylate synthetase ternary complex.

Deoxyuracil Nucleotides↗
PubMed1984

Interleukin-2 correction of defective in vitro T-cell mitogenesis in patients with common varied immunodeficiency.

We studied the ability of phytohemagglutinin (PHA) and two anti-T-cell monoclonal antibodies, OKT3 and Pan T2, to induce interleukin-2 (IL2) production and proliferation in peripheral blood lymphocytes (PBL) from 14 patients with combined varied immunodeficiency (CVI). The median values of endogenous IL2 produced by mitogen-stimulated PBL was significantly lower in patients than controls irrespective of the mitogen used. The patients, taken as a group, had a significantly decreased in vitro PBL response to mitogen stimulation when compared to controls. With the addition of a highly purified human IL2 preparation, the proliferative response in the majority of patients was significantly improved with all mitogens. Three patient groups could be distinguished: Group A (3/14) had full restoration of proliferative response with the addition of IL2, Group B (5/14) had partial restoration, and Group C (6/14) had no significant response. The monoclonal antibody, Pan T2, recognized a T-cell proliferative defect in 5 of 14 patients which neither PHA nor OKT3 recognized. This was not significantly corrected by the addition of IL2. This T-cell proliferative defect correlated with the lack of B-cell proliferation and immunoglobulin production in response to B-cell mitogens in three-fourths of the patients assayed. These data show that CVI patients are a heterogeneous group but have in common a decreased in vitro production of IL2 resulting in a proliferative defect which is correctable at least in part, in vitro, in the majority by the addition of purified IL2.

Adolescent↗
PubMed1984

Enhancement of phenotypic instability by alpha-difluoromethylornithine and butylated hydroxyanisole in rapidly induced rat liver lesions.

The effects of alpha-difluoromethylornithine (DFMO), butylated hydroxyanisole (BHA), sodium phenobarbital (PB) and 2-acetylaminofluorene (AAF) administration on the further development of rat liver nodular lesions induced in a short-term system were investigated. The results clearly demonstrated an association between DFMO and BHA treatment with reduction in numbers of persisting nodules as assayed histopathologically and by analysis of gamma-glutamyltranspeptidase (gamma GT) and glucose-6-phosphate dehydrogenase (G6PDH) positive populations. PB and to a lesser extent AAF, on the other hand, appeared to exert an opposite effect, apparently enhancing the phenotypic stability of the nodular putative preneoplastic lesions.

2-Acetylaminofluorene↗
PubMed1984

Modification of the development of N-nitrosomorpholine-induced hepatic lesions by 2-acetylaminofluorene, phenobarbital and 4,4'-diaminodiphenylmethane: a sequential histological and histochemical analysis.

The effects of 2-acetylaminofluorene (2-AAF), sodium phenobarbital (PB) and 4,4'-diaminodiphenylmethane (DDPM) on the developmental sequence of N-nitrosomorpholine (NNM) induced changes in the rat liver was investigated using a histological, histochemical and morphometric approach. Male Sprague-Dawley rats were treated with NNM for 3 weeks, maintained on basal diet for 1 week and then fed on diets containing either 0.005% 2-AAF, 0.05% PB, 0.08% DDPM or, as carcinogen controls, no addition (basal diet, BD) for a further 48 weeks. Control and experimental groups were sacrificed at weeks 4, 16, 28, 40 and 52 of the investigation. The incidence of the hepatocellular carcinomas observed at weeks 40 and 52 was markedly enhanced by 2-AAF treatment and slightly increased after PB administration. 2-AAF also exerted a positive influence on the development of angiosarcomas, benign hemangioendotheliomas and cystic cholangiomas. DDPM did not show clear effects on the development of liver cell carcinoma but enhanced the induction of cholangiofibromas, cholangiofibrosis and, very markedly, spongiosis hepatis. No neoplastic lesions were observed in animals treated with 2-AAF, PB or DDPM without prior application of NNM. Morphometric analysis of enzyme-altered foci revealed contrasting effects of 2-AAF, PB and DDPM, not only on number and size of lesion but also on their histochemical phenotype. Thus whilst 2-AAF administration was primarily linked with increase in number of lesions, PB appeared to stabilise their phenotypic cellular changes and increased the activity of G6PDH. DDPM did not significantly influence the number of focal lesions but seemed to effect a decrease in phenotypic alteration within foci. The results suggest that changes in the nature of enzyme-altered foci may be correlated with enhancement or inhibition of tumorigenesis.

2-Acetylaminofluorene↗
PubMed1984

Human interleukin 2 gene is located on chromosome 4.

The interleukin-2 (IL2) gene is assigned to human chromosome 4. A synthetic oligonucleotide representing bases 285 to 324 of the IL2 cDNA clone described by Taniguchi et al. [Nature (London) 302:305-310, 1983] was used as hybridization probe in Southern blots. Eco RI digests of DNA derived from 11 somatic mouse-human cell hybrid clones were used. The IL2 gene was localized to human chromosome 4 based on the observed combinations of segregating chromosomes and bands. Under the conditions of stringency utilized, a single 3.6 kilobase Eco RI fragment hybridized to the oligonucleotide. Molecular weight standards were provided by rehybridizing the blots with an actin cDNA clone, pAct 1, which identified actin gene Eco RI fragments of defined size.

Animals↗
PubMed1984

Modifying potential of thirty-one chemicals on the short-term development of gamma-glutamyl transpeptidase-positive foci in diethylnitrosamine-initiated rat liver.

The modifying potential of 31 different compounds on the development of gamma-glutamyl transpeptidase-positive (gamma-GT+) liver cell lesions was compared in an in vivo short-term assay system. Rats were initially given a single dose (200 mg/kg) of diethylnitrosamine intraperitoneally and 2 weeks later were treated with test compounds for 6 weeks and then sacrificed, all rats being subjected to partial hepatectomy at week 3. Modifying potential was scored by comparing the number and area (mm2)/cm2 of induced gamma-GT+ foci with those of the corresponding control group given DEN alone. 2-Acetylaminofluorene, 3'-methyl-4-dimethylaminoazobenzene, dimethylnitrosamine, phenobarbital, barbital, dipyrone and deoxycholic acid caused a significant enhancement of both the number and area of foci. 4-Acetylaminofluorene, ethionine, benzo[alpha]pyrene, disulfiram and cholic acid had a moderate enhancing effect, whereas slight, but not unequivocal, increases in gamma-GT+ foci were observed after captafol, glutathione, sodium ascorbate and taurine administration. In contrast, acetaminophen, ethoxyquin, butylated hydroxyanisole, butylated hydroxytoluene, and ethyl alcohol showed clear inhibitory effects. It is concluded that the present short-term in vivo system has practical application for the screening of modifying agents for liver tumorigenesis including hepatocarcinogens.

Animals↗
PubMed1984

Treatment of immunodeficiency with interleukin-2: initial exploration.

Fifteen patients with acquired immunodeficiency syndrome (AIDS), lymphoma and immunodeficiency, or severe combined immunodeficiency were treated with highly purified interleukin-2 (IL-2) prepared from human lymphocytes. All patients showed a defect in mitogen-induced T cell proliferation which was partially corrected when IL-2 was added in vitro. IL-2 was administered subcutaneously by daily injection or continuous infusion. The maximum daily dose was 20,000 U/m2, the maximum total dose 855,000 U/m2, and the maximum period of treatment 77 days. An increase in the platelet count was seen in one patient with AIDS, a decrease in the serum level of a monoclonal immunoglobulin in another patient with AIDS, and a minor tumor response in a patient with diffuse histiocytic lymphoma. As no toxicity was observed, further study of IL-2 in the treatment of human immunodeficiency is indicated.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Defective interleukin 2 production in patients after bone marrow transplantation and in vitro restoration of defective T lymphocyte proliferation by highly purified interleukin 2.

Using OKT3 monoclonal antibody as a mitogen, we have studied interleukin 2 (IL2) production and proliferation in peripheral blood mononuclear cells (PBMC) of 23 patients receiving bone marrow transplants. Twenty patients were recipients of allogeneic bone marrow for treatment of hematologic malignancies, aplastic anemias (AA), or severe combined immunodeficiencies (SCID). Three patients with Hodgkin's disease or neuroblastoma received autologous bone marrow. Endogenous IL2 production was not detectable (less than 0.2 U/mL) in PBMC of 18 patients and was very low in PBMC from five patients (0.5 to 1.5 U/mL), as compared to normal controls (median 3.5 U/mL) or pretransplant patients (median 1.5 U/mL). The low IL2 production was associated with defective OKT3-induced proliferation of PBMC in 19 of 23 patients studied. In the first 6 months after BMT, 14 of 15 patients (93%) showed defective proliferation of PBMC as compared to five of eight patients (63%) tested between 7 and 18 months after BMT (P less than .1). In all but three patients, addition of highly purified human lymphocyte IL2 (hpIL2) restored OKT3-induced proliferation of PBMC to within the normal range. This study demonstrates that PBMC in patients after BMT have a defect of IL2 production but are able to express IL2 receptors in response to OKT3 antibody and to proliferate normally upon addition of hpIL2. PBMC of all patients showed similar functional defects, whether or not they received additional therapy, including various conditioning regimens prior to BMT and immunosuppressive therapy after BMT. These observations suggest that T cell defects after BMT are most likely secondary to quantitative or qualitative defects of transplanted T lymphocytes or their precursors.

Anemia, Aplastic↗
PubMed1984

Human B cell-inducing factor(s) for production of IgM, IgG and IgA: independence from IL 2.

Human peripheral blood B cells are stimulated into proliferation by killed Staphylococcus aureus bacteria strain Cowan I (Sac). T lymphocytes in the presence of a T cell mitogen induce high numbers of immunoglobulin-secreting cells (ISC) in these Sac-stimulated B cells. The T cells can be largely replaced by a lymphokine factor. We describe here the 11000-fold purification of this B cell-inducing factor (BIF). BIF preparations that are free of IL 2 do not require IL 2 for optimal induction of ISC. This was shown by the lack of effect of IL 2 alone or with suboptimal or optimal concentrations of BIF on the induction of ISC and by the absence of IL 2 production in the purified B cell population which, with other controls, excludes significant T cell contamination. BIF, purified through four fractionation steps and free of IL 2, induces IgM, IgG, and IgA-ISC in approximately the same ratio as unfractionated lymphokine. Because we have not yet attained a pure BIF preparation, the possibility of separate factors for the production of each immunoglobulin isotype cannot be ruled out.

Adult↗
PubMed1983

Lymphokine factors inducing IgG production in human B-cell line ARH-77 and stimulatory effects of phorbol ester tumor promoter.

Regulation of immunoglobulin-secreting cells (ISC) was studied in human IgG B-cell line ARH-77, as assayed by reverse plaque formation. Numbers of ISC were stimulated by both lymphokine (stimulation index = 1.5-8.7) and phorbol myristic acetate (PMA) (stimulation index = 2.7-42). Incubation of ARH-77 with the two agents together caused additive or super-additive numbers of ISC, suggesting that they acted on this B cell via different mechanisms. B-cell-inducing factors stimulating IgG ISC in ARH-77 line were found at 20,000 and 40-60,000 molecular mass. The 20-KDa factor could be distinguished from IL-2 by affinity chromatography on blue agarose. Stimulated cells maintained their immunoglobulin class, and no evidence for isotype switching to IgM or IgA was detected using lymphokine or PMA. The cell line is a model for normal B lymphocytes which have been activated, for example, by Staphylococcus bacteria, to respond to T-cell factors.

Antibody-Producing Cells↗
PubMed1983

Suppression of natural killer activity in human blood and bone marrow cultures by bone marrow-adherent OKM1-positive cells.

Maintenance and regulation of natural killer (NK) cell activity in human bone marrow cultures were studied using K562 leukemia cells as targets. Culture of bone marrow cells in medium supporting long-term generation of myeloid cells resulted in a rapid loss of NK activity in 1-3 days. In contrast, antibody-dependent cytotoxicity to an NK-resistant tumor was maintained for more than 7 weeks. Horse serum, a component of the myelopoietic culture medium, was found to diminish NK cytotoxicity of blood and bone marrow cultures whereas hydrocortisone supplement did not. In addition, an adherent cell is present in bone marrow which greatly inhibits NK activity. Nonadherent bone marrow cells exhibited higher cytotoxicity than unfractionated cells at all days of culture; adherent cells were not cytotoxic to K562. Purified adherent marrow cells inhibited the cytotoxic capacity of nonadherent blood or marrow mononuclear cells during coculture. Indomethacin, an inhibitor of protaglandin synthesis, augmented levels of NK activity in cultures of bone marrow cells, indicating that macrophages may be suppressing this effector function via prostaglandins. Further identification of the adherent suppressor cells came from experiments in which suppression was prevented by treatment of the adherent cells with monoclonal OKM1 antibody plus complement. This study shows that bone marrow-adherent OKM1-positive cells, presumably macrophages, negatively regulate NK activity, and it defines conditions for analysis of the generation and/or positive regulation of NK cells in human bone marrow.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1983

Defective T-cell response to PHA and mitogenic monoclonal antibodies in male homosexuals with acquired immunodeficiency syndrome and its in vitro correction by interleukin 2.

We studied the ability of phytohemagglutinin (PHA) and two anti-T-cell monoclonal antibodies OKT3 and Pan T2, to induce proliferation and interleukin 2 (IL2) production in peripheral blood lymphocytes (PBL) from 21 homosexual patients: 12 with Kaposi's sarcoma (KS), 4 with reactive lymphadenopathy, and 5 with opportunistic infections. All patients with KS and opportunistic infections had significantly lower mitogen-stimulated DNA synthesis, as compared to the controls, irrespective of the mitogen used (P less than 0.01). The patients with lymphadenopathy exhibited significantly lower responses only in the OKT3 assay as compared to normals (P = 0.009). The production of endogenous IL2 was significantly lower in PBL cultures from patients with KS and with opportunistic infections, irrespective of the mitogen used, as compared to healthy male controls, and also significantly lower in the Pan T2-stimulated cultures from patients with lymphadenopathy. The addition of highly purified IL2 was able to restore partially lymphocyte proliferation in vitro in the presence of these mitogens in all patients. Our studies demonstrate (1) that male homosexuals even without clinical manifestations of immunodeficiency frequently exhibit a proliferative T-cell defect when anti-T-cell monoclonal antibodies rather than PHA are used as mitogens, (2) that this proliferative defect is associated with defective IL2 production, and (3) that this defect is at least in part correctable in vitro by highly purified IL2.

Acquired Immunodeficiency Syndrome↗