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Biomedical subjects

R Mertelsmann

Publications and source records attributed to R Mertelsmann.

At least 289 records · Page 16Linked to original sources

Relationship of Auer rods and chromosome findings to outcome in eighty-nine adults with acute nonlymphoblastic leukemia.

We performed cytogenetic analyses using banding techniques on 89 adults with acute nonlymphoblastic leukemia prior to receiving protocol chemotherapy. The relationships of cytogenetic findings both to outcome and to other pretreatment variables (particularly the presence or absence of Auer rods) were analyzed. Patients were followed up to 90+ months. When patients were grouped according to cytogenetic findings (NN: all normal metaphases; AA: all abnormal metaphases; AN: both normal and abnormal metaphases; F: no evaluable metaphases; I: insufficient (less than three) metaphases) no significant differences were noted with regard to age, sex, terminal transferase positivity, complete remission rate, remission duration or survival. The marrow aspirates of patients with only normal (69%) metaphases or no evaluable metaphases (64%) were more likely to display Auer rods than specimens from individuals with only abnormal (26%) or a mixture of normal and abnormal (42%) metaphases (p = 0.03). The presence of Auer rods in the pretreatment marrow aspirate was associated with an increased complete remission rate (71% vs 41%, p = 0.004), median remission duration (12 months vs 9 months, p = 0.02), and median survival (13 months vs 4 months, p = 0.01). Using multivariable analyses, the presence or absence of Auer rods was the pretreatment factor that most significantly predicted response and survival in this group of patients. The presence of a normal karyotype in the initial cytogenetic preparation is associated with the presence of Auer rods. The finding of Auer rods in the initial bone marrow predicts greater response and longer survival in acute nonlymphoblastic leukemia.

Acute Disease↗

Purification and biochemical characterization of human pluripotent hematopoietic colony-stimulating factor.

Pluripotent hematopoietic colony-stimulating factor (pluripotent CSF), a protein that is constitutively produced by the human bladder carcinoma cell line 5637, has been purified from low serum (0.2% fetal calf serum)-containing conditioned medium. The purification involved sequential ammonium sulfate precipitation, ion-exchange chromatography, gel filtration, and reversed-phase high-performance liquid chromatography. The purified protein has a molecular weight of 18,000 in NaDodSO4/polyacrylamide gel electrophoresis, both by the silver staining technique and by elution of biological activity from a corresponding gel slice, and has an isoelectric point of 5.5. Pluripotent CSF supports the growth of human mixed colonies, granulocyte-macrophage colonies, and early erythroid colonies and induces differentiation of the human promyelocytic leukemic cell line HL-60 and the murine myelomonocytic leukemic cell line WEHI-3B (D+). The specific activity of the purified pluripotent CSF in the granulocyte-macrophage colony assay is 1.5 X 10(8) units/mg of protein.

Biological Assay↗

Production of and in vitro response to interleukin 2 in the acquired immunodeficiency syndrome.

To test the hypothesis that deficient interleukin 2 (IL-2) secretion may underlie the impaired capacity of T cells from patients with Acquired Immunodeficiency Syndrome (AIDS) and the AIDS-related complex (ARC) to generate the macrophage-activating lymphokine, gamma interferon (IFN-gamma), we used five specific microbial antigens to examine IL-2 production. Mononuclear cells from only one of 32 (3%) AIDS patients secreted normal levels of IL-2, and 21 (66%) failed to produce any detectable IL-2. For 36 ARC patients, IL-2 generation was normal in nine (25%) and absent in 11 (31%). Given these results, recombinant (r) IL-2 was tested for its capacity to stimulate or enhance IFN-gamma production. rIL-2 (10 U/ml) alone stimulated cells from controls, ARC, and AIDS patients to secrete 93 +/- 25, 99 +/- 33, and 7 +/- 3 U/ml of IFN-gamma, respectively. rIL 2 (10 U/ml) plus antigen induced no change in mean IFN-gamma levels for controls, a 4.4-fold increase for 17 AIDS patients (16 +/- 16 vs. 71 +/- 21 U/ml), and a 7.2-fold increase (18 +/- 5 vs. 130 +/- 27 U/ml) for 19 ARC patients with abnormal IFN-gamma generation to antigen alone. Individual responses indicated that six of the 17 (35%) AIDS patients with opportunistic infections and 12 of the 19 (63%) with ARC were apparent responders to 10-100 U/ml of rIL-2. These results (a) document profound impairment in antigen-induced IL-2 secretion by AIDS and ARC T cells, (b) indicate that, in vitro, mononuclear cells from certain patients can respond to rIL-2 with enhanced IFN-gamma production, and thus (c) suggest that in selected patients rIL-2 might have a potentially beneficial therapeutic (AIDS) or prophylactic (ARC) effect against opportunistic infections.

Acquired Immunodeficiency Syndrome↗

13-cis-Retinoic acid does not increase the true remission rate and the duration of true remission (induced by cytotoxic chemotherapy) in patients with chronic phase chronic myelogenous leukemia.

Treatment of chronic phase chronic myelogenous leukemia with hydroxyurea or busulfan rarely induces cytogenetic (true) remissions. Intensive chemotherapy induces brief true remissions in approximately 50% of patients. We added 13-cis-retinoic acid to daunorubicin, cytosine arabinoside, and thioguanine to determine if it could increase the incidence and duration of remission induced by cytotoxic chemotherapy. Of the 17 evaluable patients, one patient (6%) achieved complete remission, and seven patients (41%) achieved partial remissions. The median duration of remission was 1.6 months. We conclude that 13-cis-retinoic acid does not increase the incidence and duration of remission in chronic phase chronic myelogenous leukemia.

Adolescent↗

Regulatory role of a monomorphic determinant of HLA Class I antigens in T cell proliferation.

The role of HLA Class I antigens in T cell proliferation was investigated by using the anti-HLA Class I monoclonal antibodies (MoAb) CR10-215, CR10-325, and CR11-115. MoAb CR10-215 and CR11-115 recognize the same (or spatially close) monomorphic determinant, which is distinct and spatially distant from that reacting with MoAb CR10-325. Addition of MoAb CR10-215 and CR11-115 to cultures of peripheral blood mononuclear cells stimulated with MoAb OKT3, MoAb Pan T2, PHA, or PPD inhibited cell proliferation. The blocking is specific in that the anti-HLA Class I MoAb CR10-325 and the Pan T MoAb Pan T1 had no effect on the proliferation. The inhibitory activity of MoAb CR10-215 and CR11-115 does not reflect i) toxic effects, ii) induction of suppressor cells and factors, iii) blocking of the binding of mitogens to lymphocytes, iv) inhibition of the production of interleukin 1 (IL 1) and interleukin 2 (IL 2), or v) function of IL 2 receptor. Anti-HLA Class I MoAb were able to inhibit the proliferation of purified, Tac-, T cells. The inhibited cells did not express Tac antigen, as assayed by direct immunofluorescence, with MoAb anti-Tac, but released a normal amount of IL 2 in culture medium. These results indicate that monomorphic determinants of the HLA Class I complex are involved in the regulation of T cell proliferation. The effect appears to occur at the level of IL 2 receptor expression.

Antibodies, Monoclonal↗

Prostaglandin E2 acts at two distinct pathways of T lymphocyte activation: inhibition of interleukin 2 production and down-regulation of transferrin receptor expression.

The mechanism by which prostaglandin E2 (PGE2) inhibits human T lymphocyte activation and proliferation was studied. We analyzed the effect of physiologic concentrations of PGE2 on interleukin 2 (IL 2) production, expression of IL 2 receptor (Tac antigen), and expression of the transferrin receptor after in vitro activation with phytohemagglutinin. PGE2 inhibited T lymphocyte proliferation by 80 to 90% of control values. This was associated with a similar degree of inhibition of IL 2 production while the expression of IL 2 receptor was not affected. This was in marked contrast to the expression of the transferrin receptor, which was inhibited 65% after 72 hr of in vitro activation. The addition of exogenous, purified IL 2 reconstituted lymphocyte proliferation to 50% of control values, but had no effect on transferrin receptor expression. Because PGE2 is known to increase the intracellular concentration of 3',5' cyclic adenosine monophosphate (cAMP), we investigated the effect of another adenylate cyclase activator, i.e., isoproterenol, as well as the effect of extracellular administration of the cAMP derivative dibutyryl cAMP (dBcAMP) on IL 2 production, Tac antigen expression, and transferrin receptor expression. It was demonstrated that isoproterenol, as well as dBcAMP, inhibited transferrin receptor expression on PHA-activated T lymphocytes to the same extent as PGE2, and exogenous IL 2 could not counteract the down-regulation of the receptor expression. In contrast, neither isoproterenol nor dBcAMP had any significant effect on IL 2 receptor expression. Prostaglandin F2 alpha (PGF2 alpha), which has been reported to elevate intracellular cyclic GMP levels, had no effect on lymphocyte activation and proliferation, and did not counteract the PGE2-induced depression in IL 2 production. In contrast to its effect on peripheral blood lymphocytes, PGE2 had no effect on transferrin receptor expression or cell proliferation by IL 2-dependent T cell clones and IL 2-independent T cell lines. These studies demonstrate that PGE2 exerts its inhibitory effects on T cell activation and proliferation via two distinct pathways: inhibition of IL 2 production and inhibition of transferrin receptor expression. The transferrin receptor inhibition is mediated via the cAMP pathway and is IL 2-independent.

Antigens, Surface↗

Interleukin 2: a review.

Interleukin 2 (IL 2) is a central mediator of the growth and functional activity of B- and T-cells, and cytotoxic cells, including Natural Killer and Lymphokine Activated Killer cells. Significant defects in the production of, and response to, IL 2 have been described in a variety of congenital and acquired immunodeficiency states. IL 2 has demonstrated major anti-tumor activity in animal models. The biochemistry and molecular biology of IL 2 and its gene are reviewed, along with data regarding the IL 2 receptor, normal T-cell activation, abnormalities in IL 2 production and response in immunodeficiency states and leukemia, and initial explorations of IL 2 in the treatment of human cancer.

Acquired Immunodeficiency Syndrome↗

Phase I and II clinical and pharmacological study of 4-demethoxydaunorubicin (idarubicin) in adult patients with acute leukemia.

Fifty-two adults treated previously with either acute leukemia (43 patients) or blastic-phase chronic myelogenous leukemia (nine patients) received 4-demethoxydaunorubicin (20 to 45 mg/sq m) i.v. over 2 to 3 days. Three of the ten patients with acute lymphocytic leukemia achieved a complete remission (CR) lasting 5 to 7 weeks. Five of the 28 patients with acute nonlymphocytic leukemia achieved a CR lasting 5 to 80 weeks. All remissions were induced with one course of treatment with a median time to CR of 28 days (range, 22 to 40 days). None of the patients with blastic chronic myelogenous leukemia or secondary leukemia achieved a CR. The drug was well tolerated; mucositis (36%), nausea and vomiting (35%), and hepatic dysfunction (26%) were the most common side effects. Pharmacokinetic observations on five patients demonstrated multiphasic clearance of 4-demethoxydaunorubicin and extensive formation and prolonged retention of 4-demethoxy-13-hydroxydaunorubicin; that metabolite accumulated in plasma on repeated daily dosing. 4-Demethoxydaunorubicin has sufficient antileukemic activity in both acute lymphocytic leukemia and acute nonlymphocytic leukemia to warrant a prospective comparison, in combination regimens, against the conventional anthracyclines, daunorubicin and/or doxorubicin.

Acute Disease↗

Lymphokine-activated killer cells are generated before classical cytotoxic T lymphocytes after bone marrow transplantation in mice.

Lymphokine-activated killer (LAK) cells are demonstrable within 2 wk after syngeneic or allogeneic (H-2-compatible) bone marrow transplantation in mice. Classical cytotoxic T lymphocytes (CTL) are not active until at least 4 wk after transplant. Both LAK cells and CTL bear the Thy-1 marker and do not possess the murine natural killer cell marker asialo GM.

Animals↗

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↗

Treatment of advanced Hodgkin's disease with chemotherapy and irradiation. Controlled trial of two versus three alternating, potentially non-cross-resistant drug combinations.

From January 1979 to June 1983, 71 evaluable, previously untreated patients with advanced Hodgkin's disease completed a randomized trial of two or three potentially non-cross-resistant drug combinations and low-dose radiotherapy to initially involved nodal regions (2,000 to 3,000 rads). All patients received nine cycles of alternating chemotherapy regimens and radiotherapy between cycles 6 and 7. Thirty-four patients received three combinations: lomustine, melphalan, vindesine (CAD), MOPP, and doxorubicin, bleomycin, vinblastine (ABV). The complete remission rate was 82 percent, partial remission rate 12 percent, and progression rate 6 percent. There were two relapses from complete remission and three deaths. Thirty-seven patients received MOPP and ABV plus dacarbazine (D). The complete remission rate was 78 percent, partial remission rate 16 percent, and progression rate 6 percent, with three relapses from complete remission and five deaths. Myelosuppression was more frequent with CAD/MOPP/ABV/radiotherapy, and nausea and vomiting with MOPP/ABVD/radiotherapy. The results for both are among the best reported, and CAD/MOPP/ABV/radiotherapy was more acceptable to patients.

Adolescent↗

Generation of nonspecific murine cytotoxic T cells in vitro by purified human interleukin 2.

Murine spleen cells developed into nonspecific cytotoxic cells within 72 hr of culture in the presence of highly purified sources of human interleukin 2. In whole spleen cell cultures, human interleukin 2 generated effector cells which were Thy 1.2+, Lyt 2.2+, resistant to gamma irradiation (1000 R), and capable of lysing both H-2 compatible and incompatible targets. The effector cells generated in this manner were not restricted to classical natural killer cell-sensitive targets. If thymus-derived cells (T cells) were depleted from the spleen cell population before culture with human interleukin 2, the effector cells generated were enriched in effectors capable of lysing natural killer cell-sensitive targets. Interferon was not produced in interleukin 2-stimulated spleen cell cultures. In addition, heterologous antibody to murine gamma-interferon did not abrogate the generation of cytotoxic cells by human interleukin 2. These and additional data suggest that human interleukin 2 is capable of stimulating gamma-irradiation-sensitive Thy 1.2+ cell(s) capable of lysing a variety of target cells regardless of inherent sensitivities to classical natural killer cells. Thy 1.2- cells were also stimulated by human interleukin 2 and lysed only natural killer cell-sensitive targets. Human interleukin 2 caused some Thy 1.2- cells to become susceptible to lysis by anti-Thy 1.2 serum and complement.

Animals↗

Autologous and allogeneic mixed-lymphocyte responses following thermal injury in man: the immunomodulatory effects of interleukin 1, interleukin 2, and a prostaglandin inhibitor, WY-18251.

A group of 30 burn patients with 36-87% total body surface area (TBSA) burns was studied at 24-48 hr postburn. These included studies of (1) autologous and allogeneic mixed-lymphocyte reactions (MLR); (2) the immunoregulatory influence of mitomycin C-treated T cells, non-T cells, and unfractionated peripheral blood lymphocytes (PBL) on allogeneic MLR; and (3) correlation between the proportions of T-cell subsets defined with monoclonal antibodies (OKT4 and OKT8) and autologous MLR. Studies concerning adherent cell production of thromboxane, prostaglandin E2, and prostaglandin F2a and the immunomodulatory effects of Interleukin 1 (IL-1), Interleukin 2 (IL-2), and a prostaglandin inhibitor, WY-18251, on autologous MLR are presented. The autologous mixed-lymphocyte reaction was depressed in 60% of the burn patients tested. This depressed response correlated closely to the extent of third-degree injury (P less than 0.025) and to TBSA injury greater than 60% (P less than 0.025). A linear correlation was observed between the depression in autologous MLR and a decrease in both the percentage of OKT4+ T cells and the OKT4+/OKT8+ ratio. The response of T cells from burn patients in allogeneic MLR was normal. Age, sex, TBSA of the burn, and size of second-degree burn did not correlate with the abnormalities observed in MLR. Mitomycin C-treated mononuclear cells, purified T cells, or non-T cells from burned patients did not demonstrate any suppressive influence on MLR in normals. Monocyte number and arachidonic acid metabolism were investigated. In addition to increased numbers of monocytes following thermal injury, adherent cells produced increased quantities of thromboxane, prostaglandin E2, and prostaglandin F2a. The effects of Interleukin 1, Interleukin 2, and a prostaglandin inhibitor, WY-18251, were studied in autologous MLR (AMLR) of burned and normal patients. Interleukin 1 and WY-18251 did not induce any significant changes in proliferation in burned patients or normal controls. When compared to cultures without exogenous IL-2, an increase in AMLR was observed following the addition of IL-2 to burn patient cultures at Day 6 and Day 7 of culture. Although the addition of IL-2 did increase proliferation in AMLR of normal controls at Day 6 and Day 7, the enhancement observed for the burn patient cultures represented a restoration to the level of normal control cultures without IL-2. A dose-dependent increase in AMLR was observed in T cells isolated from normal and burned patients in the presence of purified Interleukin 2.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗