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A L Epstein

Publications and source records attributed to A L Epstein.

122 records · Page 7Linked to original sources
PubMed1979

Feeder layer and nutritional requirements for the establishment and cloning of human malignant lymphoma cell lines.

Cell lines were successfully established in continuous suspension culture from 10 patients with a histopathological diagnosis of diffuse histiocytic lymphoma (SU-DHL-1 to SU-DHL-10), two with North American Burkitt's lymphoma (SU-AmB-1 and SU-AmB-2), and one with acute lymphoblastic leukemia (SU-ALL-1). By screening a variety of parameters, including media, sera, effusion fluids, feeder layers, and chemical supplements, the nutritive growth requirements of lymphoma cells obtained from malignant effusions and lymph node biopsies were determined for each tumor. Most of these cell lines initially required human skin fibroblast or epithelial cell feeder layers from which they could be weaned after one to six weeks in culture and maintained in Roswell Park Memorial Institute Tissue Culture Medium 1640 containing 20% fetal calf serum and 10% pooled human serum. Several of these cell lines were successfully cloned on 0.5% Noble agar substrates. In the presence of human serum and selected feeder monolayers, cloning efficiencies increased significantly from less than 1% to 15 to 25%. In addition, the cloning efficiencies of certain cell lines showed a concentration-dependent increase with specific chemical supplements including L-cysteine and dithiothreitol. Placental colony-stimulating factor, nerve growth factor, epithelial growth factor, and fibroblastic growth factor were ineffective in augmenting the cloning efficiencies of the human lymphoma cell lines. After a single passage on agar, cells subpassaged from visible colonies showed markedly increased cloning efficiencies to levels as high as 50%. Such cloning efficiencies, coupled with the use of replica plating, make this technique applicable to genetic and quantitative radiobiological, immunological, and chemotherapeutic studies. Although these methods have thus far been used only with lymphoreticular tumors, they may also be applicable to the cell culture of other human neoplasms and normal tissues.

Burkitt Lymphoma↗
PubMed1978

Biology of the human malignant lymphomas. IV. Functional characterization of ten diffuse histiocytic lymphoma cell lines.

Ten consecutive diffuse histiocytic lymphoma (DHL) cell lines established in our laboratory were studied for the presence of Epstein-Barr virus (EBV) genomes, lysozyme, nonspecific esterase and other cytochemical reactions, phagocytic activity, cytoplasmic immunoglobulin light and heavy chains, and surface receptors to sheep erythrocytes, complement, and the Fc fragment of immunoglobulin. In agreement with previous studies performed on biopsy specimens, our results indicate that the diffuse histiocytic lymphomas, as a histopathologic entity, represent a heterogeneous group of neoplasms, the majority of which are B-lymphocyte in origin. The cell lines appear to fall into three categories based on the following criteria: 1) presence of monoclonal cytoplasmic immunoglobulins (B-lymphocytic type, 6/10 cell lines); 2) presence of non-specific esterase, phagocytic activity, and/or lysozyme (histiocytic type, 2/10 cell lines); and 3) absence of all lymphoid and histiocytic cell characteristics (null cell type, 2/10 cell lines). Despite the fact that many of the lymphoma patients had positive serologies to EBV antigens, all of the DHL cell lines were negative for the presence of EBV genomes. Both of the two B-lymphocytic type and one of the two histiocytic type lines tested were susceptible to infection with EBV, as indicated by synthesis of early antigen and also, in a small proportion of the infected cells, of viral capsid antigen. These prototypic DHL cell lines may permit the development of new criteria for the differential diagnosis and treatment of this highly malignant and diverse group of lymphomas.

Animals↗
PubMed1977

Chromosome 14 translocation in African and North American Burkitt's lymphoma;.

Two established North American Burkitt lymphoma cell lines were studied by chromosomal banding techniques. The SU-AmB-1 line previously shown to be negative for the Epstein-Barr virus (EBV) was found to have, among other changes, a translocation from the long arm (q) of chromosome 8 onto 14q. The SU-AmB-2 line, which contains the EBV genome, also displayed the same 8/14 translocation. These results were compared with data from three EBV-positive tumor cell lines derived from patients with African Burkitt's lymphoma. Our findings indicate that a translocation from 8q onto 14q occurs in both African and North American Burkitt lymphomas, and that this abnormality apparently is not related directly to EBV. This chromosome translocation therefore may be an important event in the development of human lymphocytic malignancy, analogous to the occurrence of the Philadelphia chromosome rearrangement in chronic myelogenous leukemia.

Adolescent↗
PubMed1977

Isolation of a type C RNA virus from an established human histiocytic lymphoma cell line.

A type C RNA virus has been detected in the culture fluids of the SU-DHL-1 human histiocytic lymphoma cell line previously established in this laboratory. In electron micrographs, the virus closely resembled other typical mammalian type C RNA tumor viruses in size and morphology. Viral RNA-dependent DNA polymerase activity has been demonstrated in particles (densities of 1.15 and 1.22 g/ml) in the microsomal cytoplasmic fraction and in pellets of culture fluids. The enzyme is partially inhibited by antibodies to the RNA-dependent DNA polymerases of simian sarcoma virus and RD-114 virus but not by antibody to the polymerase of murine leukemia virus, suggesting some degree of relatedness to type C viruses of subhuman primate origin. Typical syncytial microplaques were induced when SU-DHL-1 cells were cocultivated with rat XC cells. Although no focus formation was noted in similarly cocultivated mouse UC1-B cell cultures, the numbers of foci induced in rat embryo fibroblasts by murine sarcoma virus were significantly increased by coinfection with the virus from SU-DHL-1 cell culture fluids. No other evidence of infectivity, inducibility, or capacity for helper rescue of defective murine sarcoma virus genomes has been detected to date in cocultivation studies with a spectrum of fibroblastic and other nonlymphoid indicator cell lines of human and other species of origin.

Cell Line↗
PubMed1976

Biology of the human malignant lymphomas. III. Intracranial heterotransplantation in the nude, athymic mouse.

Intracranial heterotransplantation in the nude, athymic mouse has been found to be an effective method for the experimental growth of human malignant lymphomas. Transplants of 11 primary lymphomas and six derived cell lines yielded a high take rate (90%) and a low mean latent period (36 days). Relatively small inocula produced extensive intracerebral infiltrates which could be identified as human in origin by immunofluorescence. Although confined to the central nervous system and meninges, the tumors were highly invasive and displayed morphologic features strikingly similar to those of the original primary tumors. Heterotransplantation of the lymphomas to extracranial sites was only rarely successful. Nude mice previously grafted with isologous neonatal thymuses failed to develop intracerebral tumors. Secondary cell cultures successfully established from several of the intracranial heterotransplants were found to be infected with NIH type-C xenotropic virus. The distinctive growth patterns and other neuropathologic features of the heterotransplants are described, and the relevance of these observations to the development of intracerebral lymphomas in immunosuppressed organ transplant recipients is noted. This method of studying human malignant lymphomas in vivo may permit better histopathologic characterization of the tumors, and may serve as a basis for further experimental lines of investigation, including viral, immunologic, and therapeutic studies.

Adolescent↗
PubMed1976

Surface marker characteristics and Epstein-Barr virus studies of two established North American Burkitt's lymphoma cell lines.

Tumor cell lines have been established in continuous culture from two North American Burkitt's lymphomas. The SU-AmB-1 line, derived from a patient with low serum antibody titers to Epstein-Barr virus (EBV), was devoid of EBV genomes by the reaction for EBV-associated nuclear antigen (EBNA), could not be induced to express EBV antigens, and was highly refractory to EBV superinfection. Conversely, the SU-AmB-2 cell line, derived from a patient with "African type" serology, yielded a positive EBNA reaction and was readily inducible and superinfectable. Although both cell lines possessed B (bone-marrow-derived) cell characteristics, they had different surface marker patterns. It is postulated that two different classes of undifferentiated B cell lymphomas exist, one of which is positive for the presence of EBV genomes and occurs endemically in Africa and New Guinea and sporadically in other parts of the world, the other of which is EBV-negative and occurs sporadically throughout the world, including the endemic areas.

Adolescent↗
PubMedDate not supplied

A phase 1a clinical trial of LYM-1 monoclonal antibody serotherapy in patients with refractory B cell malignancies.

Ten patients with refractory B cell lymphomas were treated with weekly intravenous infusions of escalating doses of murine monoclonal antibody (MoAb) LYM-1 over four weeks. LYM-1 is a recently developed IgG2a murine MoAb that recognizes a polymorphic HLA-Dr antigen on surfaces of normal and malignant B cells but does not bind to any other normal tissues. MoAb LYM-1 has several advantages for serotherapy, since the antigen it recognizes is not shed from the cell surface and does not modulate in response to MoAb therapy. Furthermore, in vitro studies have indicated significant anti-tumour activity against lymphoma cell lines. In the current trial, dose-dependent levels of free LYM-1 were detected in the serum of all patients, but penetration of extravascular tumour tissues was poor. No significant toxicity or human anti-mouse antibody responses were observed in any patient. Clinical responses were minor and appeared to correlate with the number of infiltrating T cells seen in the initial lymphoma specimens. LYM-1 appears to be well-tolerated and has demonstrated several potential advantages as a therapeutic agent in patients with lymphoma. The mechanism of anti-tumour effect and plans for further clinical studies are discussed.

Adult↗
PubMedDate not supplied

Treatment of a patient with B cell lymphoma by I-131 LYM-1 monoclonal antibodies.

A patient with Richter's syndrome, a malignant lymphomatous transformation of chronic lymphocytic leukemia, had become moribund with rapidly enlarging masses, granulocytopenia and thrombocytopenia despite the use of conventional chemotherapy and radiotherapy. Greater than ten percent of a test dose of I-131 Lym-1, a murine monoclonal antibody produced against Burkitt's African B cell lymphoma, was accumulated by her tumor. The patient was subsequently treated with a series of injections of I-131 Lym-1 with dramatic clinical response, reduction of tumor volume by x-ray computerized tomography and progression of circulating cellular elements toward normality. Her course over the next ten months was not like that to be expected for Richter's syndrome, which has an average survival of four months. This mode of treatment appears promising.

Aged↗
PubMedDate not supplied

Non-dehalogenation mechanisms for excretion of radioiodine after administration of labeled antibodies.

In patients or mice with cancer the pharmacokinetic behavior of radioiodinated and radiometal chelated antibodies has been observed to be different. Rapid clearance from the tissues and excretion into the urine can occur after injection of radioiodinated antibodies. These observations have been interpreted to reflect in vivo dehalogenation of the antibody. This publication describes a variety of other mechanisms that can underlie these phenomena. These mechanisms include receptor uptake and catabolism of antibody and instability of the labeled antibody due to the labeling conditions. Specifically, the relative masses of chloramine-T and antibody in the iodination reaction mixture, the level of iodination of the antibody, and the amount of antibody administered to the recipient are all factors which can influence the clearance of radioiodinated antibody from the recipient. The final determinant for the different behavior of radioiodinated and In-111 metal chelated antibody relate to the different biologic pathways of indium when compared to iodine.

Animals↗
PubMedDate not supplied

Improving performance in a contracted physician network.

Health care organizations face significant performance challenges. Achieving desired results requires the highest level of partnership with independent physicians. Tufts Health Plan invited medical directors of its affiliated groups to participate in a leadership development process to improve clinical, service, and business performance. The design included performance review, gap analysis, priority setting, improvement work plans, and defining the optimum practice culture. Medical directors practiced core leadership capabilities, including building a shared context, getting physician buy-in, and managing outliers. The peer learning environment has been sustained in redesigned medical directors' meetings. There has been significant performance improvement in several practices and enhanced relations between the health plan and medical directors.

Contract Services↗
PubMedDate not supplied

Application of monoclonal antibodies to tumor diagnosis and therapy.

Monoclonal antibodies prepared by somatic cell hybridization techniques are ideal tools for the discrimination of cellular antigens and are beginning to reveal qualitative and quantitative differences in the antigenic composition of normal and malignant cells. Because these reagents are homogeneous in nature, recognize specific antigenic determinants, and can be mass produced, monoclonal antibodies have important clinical applications in the detection and early diagnosis of cancer, in staging procedures, and in therapeutic trials. In addition, many of these reagents have the capacity to distinguish between different types of human tumors and will be useful in the refinement of histopathologic classification schema. Monoclonal antibodies with varying degrees of specificity have already been produced against a variety of human and animal tumors. In this review, the technical aspects of monoclonal antibody production and the clinical and biologic application of these reagents are highlighted in order to demonstrate the potential of monoclonal antibodies as tools for the immunodiagnosis and therapy of malignant disease.

Animals↗