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Biomedical subjects

G W Löhr

Publications and source records attributed to G W Löhr.

At least 19 recordsLinked to original sources
PubMed1992

Expression of the proliferation-associated Ki-67 antigen of transferrin receptors and of DNA polymerase alpha in human tumour lines: implications for in vitro chemoresistance.

To compare the time course of in vitro expression of various proliferation-associated markers including Ki-67 antigen, transferrin receptors (TfR), and DNA polymerase alpha, six human tumour cell lines of different histological origin were studied under defined conditions. Proliferation markers were demonstrated by peroxidase/anti-peroxidase staining using specific monoclonal antibodies, and their expression was compared to results obtained from [3H]-thymidine incorporation assays and cell counting. Expression of all proliferation markers began to increase during the lag phase, and occurred earlier than elevations of [3H]dT incorporation and cell numbers were recorded. Maximum expression was observed before cell growth reached plateau phase. The time courses of expression of DNA polymerase and Ki-67 were almost identical. The closest correlation of [3H]dT incorporation with time course of expression of proliferation-associated markers was observed, when intranuclear staining of DNA polymerase was analysed. TfR were expressed earlier than the polymerase and Ki-67. Since TfR were also found at remarkable levels in resting cells, they seem less proliferation-specific than Ki-67 and DNA polymerase. While in rapidly growing cell lines more than 95% of the cells expressed Ki-67, TfR, and more than 75% DNA polymerase in cell nuclei, a malignant melanoma and a pleural mesothelioma line displayed fewer than 35% of cells stained for DNA polymerase in cell nuclei during log phase. Determination of growth fractions by monoclonal antibodies may thus contribute to the prediction of chemoresistance by identifying quiescent cells that are not sensitive to S-phase-specific drugs.

Cell Division↗
PubMed1991

Demonstration of estrogen and progesterone receptors as well as Ki-67 and p-145 antigens in single tumor cells from blood and pleural effusions using a slide assay.

We describe a slide assay that allows the demonstration of antigens localized in the nucleus from isolated white blood cells as well as from single tumor cells derived from malignant effusions. With the antibodies Ki-67 and anti-p-145 an increased rate of nuclear and nucleolar staining resulted in cells from highly malignant lymphomas. An almost identical reaction was obtained when tumor cells from malignant effusions were tested. Cells isolated from the blood of patients with leukemic spread of lymphomas of low malignancy yielded a weak staining comparable to that of normal mesothelial cells from non-tumorous cavity fluids. The detection of estrogen and progesterone receptors (ER and PR) localized in the cell nucleus can be achieved by the same assay. The reaction is enhanced by incubation of the tumor cells for 30 min at 37 degrees C prior to fixation. Pleural effusions from 20 patients with breast cancer were tested. ER was positive in 13 and PR was positive in 12 of the 20 samples. In 5 cases there was a divergent reaction with ER and PR antibody. The hormone receptors of the primary tumor were known in 15 (ER) and 14 (PR) patients, respectively. In each cohort there was only one case with a negative reaction of the primary tumor and a positive reaction with the isolated tumor cells from the pleural effusions. These results indicate that the demonstration of hormone receptor proteins in cells from malignant effusions is possible and that there is a correlation with the status of the primary site of cancer.

Breast Neoplasms↗
PubMed1991

A new approach to adoptive immunotherapy of cancer using tumorcytotoxic macrophages grown from peripheral blood monocytes.

Clinical trials to evaluate the potential of adoptive immunotherapy in cancer patients have been restricted to the use of lymphoid effector cells. Of the other probably even more important host defense system against tumor growth, the mono-nuclear phagocyte system, only monocytes (mo) have been reinfused which, however, represent immature precursor cells and acquire full functional competence only upon further maturation. This is a report on 7 patients who received autologous macrophages (MO) grown in vitro from blood mo and activated by interferon-gamma (IFN gamma). Mononuclear cells were isolated from whole blood by cytapheresis and cultured for 7 days with 2% autologous serum on hydrophobic Teflon foils. Eighteen house before cell harvest, recombinant human IFN gamma was added at 200 IU/ml. Mo-derived MO were purified by counter-current elutriation. Starting with 10(8) MO cells, therapy was escalated up to the maximal number of MO obtainable from one single preparation cycle. Currently, 26 therapies have been performed with the maximal dose being 1.7 x 10(9) MO per infusion. Except for low grade fever (less than 38 degrees C), MO autografts were well tolerated, with no side effects observed. Biological response was followed by analyzing the serum levels of beta 2-microglobulin, neopterin, interleukin-6, tumor necrosis factor, and lysozyme. While in 3 out of 7 patients serum neopterin increased in response to MO therapy, other biological response parameters remained at pretreatment levels. Radiolabeled MO were shown to first accumulate in the lungs, then to pool into liver and spleen.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopterins↗
PubMed1990

Adoptive transfer of tumor cytotoxic macrophages generated in vitro from circulating blood monocytes: a new approach to cancer immunotherapy.

Cells of the macrophage lineage are considered to be of special importance in the defense of the host against tumor development and spread. Immunotherapeutic strategies to stimulate macrophage (MAC) tumor cytotoxicity make use of activating compounds such as gamma-interferon which are given systemically. However, there are several lines of evidence that in malignant disease the generation of cytotoxic effector MACs is impaired. Both defective cell maturation and loss of responsiveness to activation are described. Here, a first clinical phase I trial of adoptive immunotherapy in cancer patients using autologous MACs generated in vitro from blood monocytes (MOs) is reported. Mononuclear cells were isolated by cytapheresis and density centrifugation and cultured in hydrophobic Teflon bags for 7 days with 2% autologous serum and recombinant human gamma-interferon being present for the last 18 h. Cytotoxic MO-derived MACs were then purified by countercurrent elutriation and reinfused into the patient. A total of 72 therapies have been performed with patients being treated i.v. (n = 8) and i.p. (n = 7). In vitro generated MACs proved to be mature as judged by the expression of maturation-associated surface molecules (MAX antigens, CD16, CD51, CD71), were cytotoxic to U937 tumor cells, and were efficient secretory cells. Cell dose escalation was performed in the first patients beginning with 10(8) MACs to finally infuse the total number of cells recovered from one single cycle of isolation and culture. MAC yield varied from 1 to 17 x 10(8) representing 13-79% of MOs initially seeded. Adoptive MAc transfer was well tolerated. Side effects observed were low-grade fever (less than 38.5 degrees C), induction of the coagulation cascade, and abdominal discomfort after i.p. application. The procoagulant activity of MAC autografts was cell dose dependent and demonstrated by detection of circulating fibrin monomers and thrombin-antithrombin complexes. Biological responses observed included elevated serum neopterin levels and the appearance of interleukin-6 in sera and ascitic fluids. Indication of a possible therapeutic effect was only observed in i.p.-treated patients and consisted of disappearance of malignant ascites in 2 of 7 patients.

Adult↗
PubMed1990

Surface phenotype analysis of human monocyte to macrophage maturation.

Cells of the mononuclear phagocyte system arise from circulating blood monocytes. Upon emigration from the vasculature, monocytes differentiate into macrophages, a process that monocytes similarly undergo in vitro. We have established primary cultures from elutriated or adherence-purified blood monocytes and analyzed the antigenic modulation during monocyte to macrophage transformation, which could be followed by the expression of specific antigens and which required as yet unknown inducer signals present in the serum. It is shown that in the absence of serum monocytes only survive in vitro when cultured adherent to plastic but rapidly die in suspension culture. Starting at 0.5%, serum induced maturation dose-dependently, with the optimal concentration being 2 to 5%. Of those antigens not present on monocyte, the low-affinity Fc receptor (CD16), the alpha-chain of the vitronectin receptor (CD51), gp65-MAX.1, and gp68-MAX.3 were expressed only upon serum-induced macrophage differentiation, whereas the transferrin receptor (CD71), MAX.26, and to some degree also gp65-MAX.11 appeared to be independent of maturation and were also found on primary cultures of adherent monocytes under serum-free conditions. In addition, the rapid induction of HLA class II antigens (within 24 hr) was similar with and without serum, as was the continued high-density expression in long-term culture. The monocyte-specific CD14 antigen was down-regulated in the absence of serum but kept its level of expression on differentiated macrophages. In comparison, alveolar and peritoneal macrophages, respectively, differed in their antigenic phenotype: Alveolar macrophages expressed high HLA class II antigens but low CD14, whereas for peritoneal macrophages the opposite was found. Both interferon-gamma and -alpha suppressed macrophage maturation in vitro but had contrary effects on HLA class II and CD16 expression: Interferon-gamma up-regulated the two types of antigens, which, in contrast, were down-regulated by interferon-alpha.

Antigens, Surface↗
PubMed1990

Restoration of nonclonal hematopoiesis in chronic myelogenous leukemia with interferon alpha.

Studies have shown that recombinant human alpha interferon (rIFN alpha) inhibits the growth of colonies of multipotential stem cells from human bone marrow. This report demonstrates that rIFN alpha inhibits the growth of such colonies from the bone marrow of patients with chronic myelogenous leukemia (CML) to a greater extent than from bone marrow of healthy individuals. It also shows that T lymphocyte colonies subcloned with interleukin 2 (IL-2) from CML mixed colonies were inhibited more by rIFN alpha than were similar colonies subcultured from normal mixed colonies. The report demonstrates that the Ph' chromosome is present in such T cell colonies subcultured from CML mixed colonies. When mixed colonies were grown from CML bone marrow in the presence of rIFN alpha, Ph' negative colonies were observed, whereas no such Ph' negative mixed colonies grew from a similar number of bone marrow cells incubated without rIFN alpha. These observations confirm that T lymphocytes derived from bone marrow stem cells are from the CML clone, and that the inhibition of growth of Ph' positive colonies, by rIFN alpha permits the growth of residual normal stem cells. The disappearance of the Ph-chromosome in subclones of T lymphocytes supports the notion of nonclonal hematopoiesis in patients with CML.

Hematopoiesis↗
PubMed1989

Defective monocyte-to-macrophage maturation in patients with aplastic anemia.

Macrophages (MAC) are important effector cells of the immune system but also play an essential role as regulatory cells in hematopoiesis. They originate from circulating monocytes (MO) as immature precursor cells that undergo terminal differentiation upon migration from the capillary bed into the various tissues. In the presence of serum, MAC maturation from blood MO is observed in vitro and can be followed by the expression of maturation-associated antigens (MAX.1, .3, .11, and .26; transferrin receptor, 13C2, CD16). We have tested blood MO from 22 patients with aplastic anemia (AA) for their capacity to undergo terminal maturation in vitro. After isolation, blood MO in six patients expressed CD14 molecules at low density when compared to normals. On culture for 7 days, in 15 patients various abnormalities could be shown by phenotype analysis using cell-enzyme-linked immunosorbent assay (ELISA) and an immunoperoxidase staining technique of single cells. Abnormalities ranged from the distinctive failure of mature MAC to express single surface antigens (eg, gp64-MAX.1) to complete inhibition of the development of a MAC maturation-associated phenotype. In three patients the maturational defect was found to persist in complete remission after successful therapy with antileukocyte globulin (ALG). Neither in other immunosuppressed or multiple-transfused patients nor in those with bone marrow hypoplasia secondary to cancer chemotherapy and during hematologic reconstitution following autologous bone marrow transplantation (BMT), defective MO maturation in vitro was seen. Our data provide evidence for the existence of serious disorders within the MO-MAC lineage in patients with AA. This observation may either reflect the stem-cell defect or indicate a MAC involvement in the pathogenesis of the disease.

Anemia, Aplastic↗
PubMed1989

Effects of human bone marrow stroma on the growth of human tumor cells.

As some tumors metastasize frequently to marrow we modified the clonogenic assay for human tumor cell growth by culturing tumor cells in the presence of human bone marrow stromal cells. In a bilayer soft agar assay, human tumor cells which had been passaged in nude mice were plated in the agar overlayer on an underlayer containing a suspension of trypsinized human bone marrow stromal cells. These marrow stromal cells stimulated the growth of tumor cells in a dose-dependent fashion, with a growth peak at a stromal cell density of 5-10 x 10(5)/ml. The maximal stimulation of tumour cell growth was 13-fold. We evaluated clonal growth of six separate tumors of five different histological types (small and large cell bronchogenic carcinoma; mammary carcinoma; malignant melanoma; pleural mesothelioma) and demonstrated that in 9 of 11 experiments tumor cell colonies formed in the absence of stromal cells, but colony growth was markedly stimulated by stromal cells in every case. Stromal stimulation persisted after irradiation of the stromal cells with 10 Gy. Growth of five fresh human tumor samples was similarly stimulated by the presence of human bone marrow stromal cells. Tumor cell colonies were characterized morphologically by Pappenheim stain and immunologically for surface antigens by peroxidase-antiperoxidase immunostaining utilizing monoclonal antibodies (carcinoembryonic antigen 26/3/13 and 26/5/1, EMA, HEA125, Sam 2 and Sam 10) which detected epithelial cell antigens. Colonies consisted of cytologically malignant cells which expressed epithelial cell antigens. Thus, the tumor cell origin of colonies from mammary carcinoma and bronchogenic small cell, large cell, and adenocarcinoma was proven. This tumor stem cell assay permits further analyses of human tumor cell biology and may be useful for testing drug sensitivity.

Adenocarcinoma↗
PubMed1989

CGP 6809--a new nitrosoureido-sugar derivative with activity in human tumor xenografts.

CGP 6809 [ethyl-6-deoxy-3,5-di-O-methyl-6-(3-methyl-3-nitrosoureido)-alpha-D- glucofuranoside] is a new methylnitrosoureido-sugar derivative that has been shown to be active against a broad spectrum of transplantable tumours in mice and rats. We investigated the anti-tumour effect of CGP 6809 in ten selected, human tumour xenograft lines growing s.c. in nude mice. The p.o. administration of 125 mg/kg per day for 10-15 days was less toxic (lethality 12% in tumour-bearing nude mice) than the i.p. injection of 62.5 mg/kg per day (lethality 22%). The anti-tumour effect was similar for both application routes; two large bowel cancers responded to treatment with CGP 6809, rectal cancer CXF 158 showed a remission, and the rapidly growing, undifferentiated colonic cancer CXF 280 exhibited a transient no-change. Furthermore, remissions were observed in the epidermoid lung cancer LXF 322 and in thyroid cancer 117. Tumour progression was found in another epidermoid lung cancer and in three stomach cancers, one melanoma, and one soft tissue sarcoma. CGP 6809 is a promising new agent for clinical trials, especially for large bowel and epidermoid lung cancer.

Animals↗
PubMed1989

Human macrophages can express the Hodgkin's cell-associated antigen Ki-1 (CD30).

The normal precursor of the neoplastic cell in Hodgkin's lymphoma is still unknown. Previous reports on the expression of the Hodgkin's cell-associated antigen Ki-1, CD30, on normal cells have been limited to activated lymphocytes. This study demonstrates, however, that cells of the macrophage lineage also are able to express the Ki-1 antigen. The Ki-1 antigen is absent from normal blood monocytes but expressed on up to 85% of macrophage-type cells developed during subsequent in vitro differentiation on Teflon membranes. Unlike other maturation-associated antigens, Ki-1 is found only at late stages of the macrophage primary cultures. Its expression can be enhanced by human interferon-gamma in a fashion similar to that of HLA-DR molecules. In addition, freshly explanted tumor cells from three patients with histopathologic and clinical features consistent with the diagnosis of true histiocytic lymphoma or malignant histiocytosis as well as the permanent cell line SU-DHL-1 could be demonstrated to express the Ki-1 antigen. The phenotype of histiocytic malignancy was further evaluated to be HLA-DR+MAX.26+CD25+-EMA+OKT9+Ki-1+. The results could indicate either that Hodgkin's lymphoma may arise not only from the lymphocyte but also from the macrophage lineage or may emphasize a macrophage involvement in the pathogenesis of this disease.

Antibodies, Monoclonal↗
PubMed1988

Acute lymphoblastic leukemia in adult identical twins.

The development of acute lymphoblastic leukemia (c-ALL) in identical twins is reported. The first born had ALL in 1982 and bone marrow transplantation was performed in first complete remission (CR) from his healthy twin-brother the same year. The bone marrow donor developed ALL in 1985; he received an autologous bone marrow transplantation in first CR in 1986. Unfortunately, both patients relapsed in 1986. Cytogenetic studies of the first born revealed multiple chromosomal abnormalities and a marker chromosome whereas the second patient had a Philadelphia chromosome. Genetic reasons or exposure to leukemogenic agents may be responsible for the onset of these leukemias.

Adult↗
PubMed1988

Activation of human monocyte-derived macrophages cultured on Teflon: response to interferon-gamma during terminal maturation in vitro.

Macrophages (M phi) are potential antitumor effector cells derived from circulating blood monocytes (mo). Most studies on human mo/M phi biology and function have been performed using immature mo precursor cells. However, the conclusions drawn may be questionable, as mo have to undergo terminal differentiation before they reach relevant tissue sites of inflammation and immune reaction. We have analyzed the ability of mo-derived, teflon-cultured M phi to respond to activating stimuli with an increased tumor cytotoxic effector cell function using recombinant interferon-gamma (IFN-gamma), IFN-alpha 2, granulocyte/macrophage colony stimulating factor (GM-CSF), interleukin(IL) 2, IL 1 alpha, and bacterial lipopolysaccharides (LPS) as mediator molecules. It could be shown that the response of M phi to the most potent activator molecule, IFN-gamma, depends on the terminal differentiation from the mo stage to the mature M phi. Whereas adherent mo could be activated only moderately, M phi increased their cytotoxicity by a factor of up to 400. IFN-gamma activation positively correlated with the effector cell number, the time of incubation and the dosage used. Activation did not depend on the presence of LPS, and was lost within 24 to 48 h. LPS itself activated cells only in the microgram range. IFN-alpha 2 activated M phi only at a two log higher concentration than IFN-gamma; GM-CSF was only slightly effective, whereas M phi incubation with IL 1 alpha or IL 2 did not result in M phi activation. Thus, the ability of human M phi to become activated appears to be a function of cellular maturation and is acquired during the terminal step of M phi differentiation. Teflon-cultured M phi could facilitate studies of the activation of human M phi and may be more suitable cells for adoptive immunotherapy in cancer patients than blood monocytes.

Cell Differentiation↗
PubMed1988

Megakaryocytic colony-stimulating activity in patients receiving a marrow transplant during hematopoietic reconstitution.

Megakaryocytic colony formation is dependent upon growth-stimulating activities present in human serum or plasma. Factors with diverse biological activities including megakaryocytic colony-stimulating activity (Mk-CSA) are provided by the medium of mitogen stimulated peripheral mononuclear cells or subsets of peripheral T cells. In this communication we describe the stimulatory activity of plasma collected from allogeneic and autologous bone marrow transplant recipients on the growth of megakaryocytic colonies. Mk-CSA was found to increase after transplantation as bone marrow regenerated. The stimulatory activities for CFU-M were greater in plasma from allogeneic bone marrow transplant patients receiving T cell-depleted donor marrow than in patients receiving unmodified donor marrow. Growth-promoting activities derived from mitogen-stimulated lymphocytes of T4 phenotype, a potent source of Mk-CSA, did not increase the frequency of CFU-M when cultured in plasma collected from transplant patients receiving a T cell-depleted donor marrow. However, a further increase in the number of CFU-M was observed when exogenous Mk-CSA was added to the cultures supplemented with plasma from patients receiving unmodified donor marrow. Plasma of patients who received autologous marrow displayed similar Mk-CSA activity when compared with the activity of plasma obtained from transplant recipients receiving an unmodified allogeneic donor marrow. Stimulatory activities supporting multilineage colonies (CFU-GEMM), erythroid bursts (BFU-E), and granulocytic colonies (CFU-C) derived from plasma of the three different transplant groups revealed no statistical difference with respect to the frequency of CFU-GEMM, BFU-E, or CFU-C colonies when compared with pretransplant plasma. The results suggest that MK-CSA may play an important role in the regulation of megakaryopoiesis in vivo. Moreover the data suggest the presence of humoral regulators that appear to be different with respect to the processing of the donor marrow.

Antineoplastic Agents↗
PubMed1988

[Effectiveness and side effects of recombinant alpha-2a interferon in patients with metastatic hypernephroma].

Eighteen patients with advanced renal cell carcinoma were treated with recombinant interferon alpha-2a (18 million IU s.c. three times a week). 9 patients had received prior hormonal therapy (tamoxifen). On entering the therapeutic schedule with recombinant interferon alpha-2a, all patients had progressive disease with multiple metastases. Flu-like symptoms occurred in general; they were severe in 9 cases. An impairment of the liver was shown by a rise of SGOT/SGPT and alkaline phosphatase in 2 patients, the gamma-GT was raised in 7 patients. The kidney function worsened in 3 cases. A fall in blood cell counts was seen in 8 cases. Five patients developed a transient stomatitis. Five patients (5/18) showed stable disease with the longest response duration of 17 months. One patient showed a complete remission 5 months after starting therapy for a duration of 7 months until now. Both the limited benefit from this treatment as well as some severe side effects indicate the need for further special evaluation and possible improvements of this therapeutic approach.

Adult↗
PubMed1988

Microculture assay for human macrophage maturation in vitro. Cell-ELISA analysis of differentiation antigen expression.

The terminal differentiation of monocytes (mo) to macrophages (MO) is essential for the complex functioning of the mononuclear phagocyte system. Similar to in vivo MO maturation, blood mo transform to MO when cultured in vitro. This offers a model system for experimental studies of functional defects within this cell lineage. In order to develop a microassay for the evaluation of MO maturation in vitro we monitored the antigenic phenotype of MO during differentiation in vitro. The cells were grown either in suspension on hydrophobic Teflon foils, or as plastic adherent monolayers. Surface antigens were visualized on single cells with the immunoperoxidase slide technique or quantitated with the enzyme-linked immunosorbent assay (ELISA). As MO mature in vitro they increase in cell size, in the amount of beta-2-microglobulin, the myeloid antigen CD14 and HLA-DR antigen expression as measured with cell-ELISA, both in microwell cultures and on single cells. Upon terminal differentiation mo-MO express differentiation-specific antigens (transferrin receptor, surface transferrin and antigens of the Max series) which are indicative of a successful MO maturation. Monocyte cultures in microplates and the subsequent evaluation of differentiation antigen expression could be used as an experimental system to study the modulation of MO differentiation in vitro and may serve as an in vitro parameter of MO function in vivo.

Antigens, Differentiation↗