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Biomedical subjects

N Epstein

Publications and source records attributed to N Epstein.

At least 19 recordsLinked to original sources
PubMed1992

Self-concept dimensions of clinically depressed and anxious outpatients.

Principal components analyses of the Beck Self-Concept Test (BST) were conducted independently for 288 women with primary mood disorders, 230 women with anxiety disorders, 236 men with mood disorders, and 161 men with anxiety disorders. Four self-concept dimensions that reflected (1) Intellectual Ability; (2) Work Efficacy; (3) Physical Attractiveness; and (4) Virtues/Vices occurred within the four samples. For 5-item subscales that represent these four dimensions, a two-way MANOVA found significant effects for sex and type of disorder. Women described themselves as having less intellectual ability than men did. Outpatients with mood disorders considered their physical appearance, work efficacy, and virtues/vices to be less acceptable than did those with anxiety disorders. Findings were discussed with respect to the cognitive content-specificity theory of psychopathology.

Adult↗
PubMed1991

Targeted integration of adeno-associated virus (AAV) into human chromosome 19.

A key feature in adeno-associated virus (AAV) replication is efficient integration of the viral genome into host cell DNA to establish latency when helper virus is absent. The steps involved in this process remain largely uncharacterized, even though AAV integration was first documented 20 years ago. Using a protein--DNA binding method we isolated AAV--cellular junction DNA sequences. The cellular component hybridized to a single restriction fragment in the virus-free parental cell line, and also co-migrated with AAV-specific sequences in numerous latently infected cell lines. Analysis of somatic cell hybrids indicated that this cellular sequence maps to the distal portion of the q arm of human chromosome 19. In situ hybridization of AAV DNA to chromosomes from latently infected cells confirms the physical location of AAV integrations to be q13.4-ter of chromosome 19. Sequence analysis of several independent integration sites shows breakpoints occurring within a 100 bp cellular region. This non-pathogenic parvovirus thus appears to establish viral latency by integrating its DNA specifically into one chromosomal region. Such specific integration is so far unique among the eukaryotic DNA viruses. The incorporation of site-specific integration into AAV vector schemes should make this vector system attractive for human gene therapy approaches.

Base Sequence↗
PubMed1991

Oral colon lavage solutions containing polyethylene glycol may interfere with ELISA detection of tumor-associated antigens in colonic effluent.

Immunologic methods for detection of colorectal neoplasia based on examination of stool or colonic effluent are being developed. Most current oral lavage preparations contain polyethylene glycol (PEG), and if PEG adversely interferes with immunologic testing these tests may become less useful. We describe a decrease in sensitivity of ELISA for tumor-associated antigens (TAA) when effluent samples are diluted in PEG-electrolyte lavage solution, equivalent to a commonly used oral lavage solution based on PEG. Radioisotope-labeled antigen binding to plastic plates was decreased by dilution in the PEG lavage solution. Antigen binding, present in colonic effluent collected by the laxative purge method, was absent in effluent collected by PEG oral lavage from the same patient. We conclude that PEG and PEG-containing lavage solutions interfere with ELISA detection of TAA in colonic effluents. We speculate that the in vitro, and possibly the in vivo, effect occurs at the level of antigen binding to the plate either by a steric effect or alteration of charge by the nonpolar properties of PEG.

Absorption↗
PubMed1990

The "warm" sacroiliac joint. A finding in pelvic abscess.

Two patients with pain referable to the low back and sacroiliac regions had bone scans with similar findings. In each, one sacroiliac joint was "warm" (uptake on that side was slightly greater than that in the contralateral area). Ga-67 imaging also demonstrated increased uptake in the same locale. Subsequent CT scanning revealed pelvic abscesses adjacent to the affected joints. Asymmetric uptake of bone imaging agent may have been related to hyperemia and "heating" of the sacroiliac joint. Rapid defervescence with antibiotics and drainage (and no CT evidence of bone involvement) suggested that osteomyelitis was not involved in these cases.

Abscess↗
PubMed1989

Common variable immunodeficiency: a family study and therapeutic trial with cimetidine.

Various immunologic parameters were tested in a family of two patients with common variable immunodeficiency. Both patients had low serum immunoglobulin levels, low peripheral B cell and T4 subclass of lymphocytes, and reversed T4/T8 ratio. One of the patients had excessive suppressor activity. Two of the asymptomatic members of the family (the father and one brother) had also low T4/T8 ratio that was not associated with excessive suppressor activity. No linkage between the disease inheritance to HLA could be observed. A study of the T cell helper activity to an antigen, the response to which is regulated by an HLA-linked gene, suggested a defect in the immune response of the two patients and their asymptomatic brother with immunologic disorders. Treatment with cimetidine of the patient with excessive suppressor activity led to an improvement in his clinical state, reduction in suppressor activity, temporary effect on his proliferative response capacity to mitogens, and an increase in the antigen-specific helper activity.

Adult↗
PubMed1989

The role of cognitions in marital relationships: definitional, methodological, and conceptual issues.

Although there have recently been numerous investigations exploring the role of couples' cognitions in an attempt to understand marital distress, at present there is little cohesion and direction in the study of how couples think about their relationships. The current article asserts that this lack of direction results from at least three factors: (a) a lack of delineation of the important cognitive variables to be considered in marital functioning, (b) conceptual and methodological difficulties that arise in attempts to operationalize cognitive variables, and (c) a dearth of models of marital functioning that incorporate cognitions in a detailed manner. These three factors are discussed, along with a review of empirical investigations supporting the importance of cognitions in intimate relationships.

Adaptation, Psychological↗
PubMed1988

The human genes for GM-CSF and IL 3 are closely linked in tandem on chromosome 5.

As demonstrated by long-range mapping of restriction endonuclease recognition sequences and genomic cloning, we found that the human genes encoding interleukin 3 (IL 3) and granulocyte/macrophage colony-stimulating factor (GM-CSF) are tandemly arrayed on the long arm of chromosome 5, separated by 9 kilobases (kb) of DNA. This close physical linkage of genes with similar structure and biologic function suggests that these cytokines may have evolved from a common ancestral gene. This linkage in evolution of two relatively divergent genes further implies that some of the other lymphokine and cytokine genes that appear to share as much or more sequence similarity than do IL 3 and GM-CSF may be distantly related members of a cytokine gene family.

Chromosome Mapping↗
PubMed1987

Development of monoclonal antibodies directed against different epitopes of human chorionic gonadotropin.

Human chorionic gonadotropin (HCG) is a 40,000 dalton glycoprotein composed of two non-identical alpha- and beta-subunits. HCG and other related pituitary hormones, such as human luteinizing hormones (HLH), human follicle stimulating hormone (HFSH), and human thyroid stimulating hormone (HTSH), consist of nearly identical alpha-chains. However, their beta-chains show a variable degree of amino acid sequence homology. Detection and subsequent quantitative determination of HCG in human biological fluids is useful in early diagnosis of pregnancy and in monitoring of tumor patients. For these applications monoclonal antibodies (McAbs) with defined specificity are required. Several hybridomas secreting McAbs to HCG have been isolated. The hybridoma cells have been developed by fusion of NS1 myeloma cells with spleen cells of Balb/C mice immunized with HCG. With the aid of an enzyme linked immunosorbent assay, six McAbs were characterized. McAbs A-73, A-76 and A-112 recognize an epitope present on the alpha-HCG subunit. McAbs B-68, B-69 and B-106 recognize an antigenic determinant associated with the beta-HCG subunit. Two of these McAbs: B-68 and B-69 are directed against an epitope on the B subunit specific to the HCG molecule and B-106 McAb towards an epitope common to HCG, TSH, LH and FSH molecule. In a hemagglutination test, only the A-73 McAb is capable of inducing agglutination of sheep red blood cells coated with HCG, thus suggesting that this McAb recognizes a repeating epitope on the alpha-HCG molecule.

Animals↗
PubMed1987

Human cell lines secreting lymphokines. I. Establishment of T-T hybridomas.

Lymphokines (Lks) are conventionally produced by mitogen stimulation of T lymphocytes. However, this procedure results in a mixture of factors, some of which may have antagonistic effects. An alternative method of producing Lks is the construction of monoclonal T-T hybridomas which secrete distinct Lks. By adapting the hybridoma technology for T cells, one can select distinct T hybridomas which may serve as constant sources for the production of uniform and well defined Lks. Since the compatibility of a certain cell line to serve as a fusion partner is unpredictable, several lines were tried in the hybridization procedure. An obligatory requirement of such a mutant line is its sensitivity to a selective medium, in which only the hybrid cell would survive. For this purpose three 8-azaguanine (8AG) resistant mutant lines (Jurkat/12 CEM/14 and Molt-4/10) were established from the respective T leukemic cell lines. This was achieved by culturing the cells in the presence of 200 microM 8AG. The surviving resistant cells were sensitive to aminopterin and azaserine inhibitors. Depending on the cell line and the inhibitor, death of these mutants was complete in 7 to 14 days. Non-adherent peripheral blood lymphocytes (PBL) stimulated for 48 hours with 1 microgram/ml phytohemagglutinin (PHA), were fused with the CEM/14 line. Fifteen hybridomas secreted a substance with B cell growth factor (BCGF) activity, nineteen hybridomas secreted T cell growth factor (IL-2), and eight hybridomas secreted gamma-interferon (gamma-IFN). The six lines which exhibited BCGF activity only, were expanded and cloned. The BCGF activity in the supernatant of a positive clone, designated TH-5, was found to be 3-fold more potent than a preparation of BCGF obtained by stimulation of PBL with PHA.

Cells, Cultured↗
PubMed1987

Human cell lines secreting lymphokines. II. BCGF production by a T hybridoma and B cell lines.

B cell growth factor (BCGF) is a lymphokine (LK) primarily produced and secreted by activated T cells. This LK induces proliferation of B cells in culture and can maintain continuous growth of human B cells. One of the putative uses of this factor might be the establishment of monoclonal B cell lines which secrete specific antibodies. These antibodies could be used for passive immunization or in vivo immunodiagnostics. As conventional mitogen activation of T cells induces the secretion of many factors, some of them with opposite effects, the approach taken by us and others was to establish monoclonal hybridomas which produce constitutively a single factor. Such a human T-T cell hybridoma (TH-5), has been established and is growing and secreting constitutively BCGF for the tested 18 months. This BCGF induces proliferation of human B-cells without the requirement of B cell preactivation. No secretion of interleukin-2 or gamma-interferon by this hybridoma was detected. Furthermore, no influence of this factor was detected on T cells. Under optimal growth conditions, the generation time of this hybridoma is 16 hours and it reaches a maximum concentration of 3 X 10(6) cells/ml. The hybridoma cells could grow in serum-free-media and secrete BCGF for a limited time. The produced BCGF was found to be stable for the four tested months at -20 degrees C, at least one week at 4 degrees C and several hours at 37 degrees C. Its activity was destroyed at pH 2.(ABSTRACT TRUNCATED AT 250 WORDS)

B-Lymphocytes↗
PubMed1987

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. II. Use of monoclonal antibodies to carcinoembryonic antigen for antigen purification and characterization.

Monoclonal antibodies (McAbs) were prepared against carcinoembryonic antigen (CEA), derived from human metastases to the liver of primary colon adenocarcinoma. A stable clone, secreting monoclonal anti-CEA antibody (Ab), was selected. The hybridoma cells were grown in BALB/C mice, forming ascites fluids containing 2-5 mg/ml of the relevant McAbs. Ascites fluids were purified using a DEAE-Sephacel column. The purified immunoglobulin fraction was characterized as IgG2b, having a dissociation constant of 2 X 10(-9)M. The potential use of these McAbs for CEA diagnosis and purification was evaluated: the IgG2b fraction, when bound to Sepharose 4B, facilitated the purification of CEA from spent media of a human colon adenocarcinoma cell line, resulting in iodination grade CEA; the anti-CEA McAbs demonstrated differential histochemical staining of various sections, both fresh and fixed; the McAbs were also found to be suitable as tagging Abs in a CEA RIA.

Adenocarcinoma↗
PubMed1987

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. I. Large-scale cultivation of carcinoembryonic antigen-producing cells on cylindric cellulose-based microcarriers.

A continuous cell line from a human colon carcinoma, designated HuCC1-14, was successfully grown on cyclindrical cellulose microcarriers (MC) charged by DEAE. The cells grow on these carriers as large cell-MC aggregates and maintain high cell densities in submerged conditions for extended periods. HuCC1-14 cells secrete into the culture medium significant amounts of carcinoembryonic antigen (CEA). Maximum efficiency in CEA secretion occurred after the cells switched from logarithmic growth to stationary phase. At this state, high CEA levels could be obtained with low-serum medium which greatly facilitates subsequent product purification. The described method provides a system which can be scaled-up and produce this tumor-associated antigen in essentially unlimited amounts and reproducible quality for detection and monitoring of cancer patients.

Adenocarcinoma↗
PubMed1986

Long-term culture of infant leukemia cells: dependence upon stromal cells from the bone marrow and bilineage differentiation.

Infant leukemia cells with 46XY,t(11; 17)(q23; p13) karyotype and a hybrid pre B myeloid phenotype (HLA-DR, (Ia), B4 and My7-positive and CALLA and T11-negative) and immunoglobulin heavy chain gene rearrangement were maintained in long-term culture for over 10 months. The in-vitro survival and growth of the leukemia cells were strictly dependent upon the presence of their autologous marrow stromal cells. The latter could be replaced by the 14F1.1 clone of preadipocytes derived from mouse bone marrow. Neither heterologous human marrow or foreskin fibroblasts nor fibroblast or endothelial like cell lines from mouse stroma could mimic the effect of autologous stroma or 14F1.1 adipocytes. The leukemia cells maintained their original phenotype throughout the 10-month culture period with either their autologous stroma or the 14F1.1 adipocytes. They could be induced to differentiate in two distinct directions. Phorbol myristate acetate induced adherence of the leukemia cells and development of macrophage properties. In contrast, conditioned medium from a hybridoma producing B-cell growth factor caused aggregation of the leukemia cells and expression of CALLA antigen and surface IgM. This bipotency of the leukemia cells and their dependence upon marrow stroma are properties in common with stem cells.

Bone Marrow Cells↗