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Biomedical subjects

R Levy

Publications and source records attributed to R Levy.

At least 739 records · Page 41Linked to original sources
PubMed1980

Role of Ia-positive cells in induction of secondary human immune responses to haptens in vitro.

We have described techniques for induction of primary and secondary human immune responses in vitro to lymphoid cells modified with trinitrophenyl, dinitrophenyl, and fluorescein isothiocyanate. Optimal secondary proliferative responses required the presentation of hapten on stimulator cells that shared HLA-D region determinants with the responder cell and/or the original stimulator cell. In contrast, hapten-specific cytotoxic responses assessed on modified allogeneic targets with no detected HLA homology with the responder were comparable in magnitude to those detected on modified autologous targets. Furthermore, secondary proliferative, but not cytotoxic, responses required presentation of Ia+ stimulator populations. Modified B cells, surface-immunoglobulin-negative, non T cells (null-cells), and Ia+ activated T cells all induced proliferative responses at least as effectively as equal numbers of hapten-conjugated macrophage/monocytes. Conversely, Ia(-) null cells and macrophages were entirely unable to stimulate. The data thus suggest that for proliferative responses, primed human T cells respond to modified lymphoid cells only when hapten is recognized in the context of Ia molecules.

Cytotoxicity, Immunologic↗
PubMed1980

Eosinophilic granuloma of the temporal bone. Two cases with bilateral involvement.

Bilateral involvement of the temporal bones is a rare manifestation of eosinophilic granuloma, a disease characterized by solitary or multiple foci of osteolytic damage. We report two cases in which the ambiguous and unusual initial symptoms and clinical course constituted a difficult diagnostic problem. In each case, the therapeutic approach used was different: the first was treated with a combination of radiotherapy and corticosteroids and the second with a combination of chemotherapy and corticosteroids. We have reviewed the literature, and the possible symptoms and clinical course are described. We report our views on the diagnostic and therapeutic aspects of the disease.

Child↗
PubMed1980

A sensitive plaque inhibition technique for assay of antibodies to influenza virus: use to detect previous antigenic priming with influenza viruses.

Plaque reduction test performed in MDCK cells was found to be a more sensitive assay than hemagglutination inhibition, for revealing previous immunological experience with influenza A virus in the population. Based on the preimmunization antibody levels, determined by plaque reduction tests, it was possible to distinguish between previously primed and unprimed subjects among vaccinees.

Adolescent↗
PubMed1980

Detection of T and B cell antigens hybridoma monoclonal antibodies: a biotin-avidin-horseradish peroxidase method.

Acetone-fixed frozen sections of reactive lymph node, spleen, three B cell lymphomas, and three T cell lymphomas were studied for the presence of Ia-like antigens and two T cell antigens. Detection of the binding of the hybridoma monoclonal antibodies to these antigens took advantage of the biotin-avidin interaction. The detection method employed a biotin conjugate of goat anti-mouse antibody and an avidin conjugate of horseradish peroxidase. B cell lymphoma cells stained for Ia. The cell lymphomas were shown to be heterogeneous for the expression of the two T cell antigens. these three antigens were generally not detectable after 10% formalin fixation of B-5 fixation. Detection of these antigens and the method employed should prove useful in the immunologic categorization of human lymphomas.

Animals↗
PubMed1980

Computed tomography in the elderly: I. The normal population.

Computed tomographic (CT) and brief psychometric findings on 50 psychiatrically and neurologically healthy community residents over 60 years old are presented. The need for normative CT data is emphasized, and the methodological problems in obtaining them are discussed. Measures of ventricular size were generally found to be greater than those reported by other workers, and variation with age was also found to be less marked than hitherto reported. A reciprocal relationship was found between a global rating of cortical atrophy and a test of memory and orientation. This communication forms the basis for comparison with groups of psychiatric patients to be presented in subsequent articles.

Age Factors↗
PubMed1980

Computed tomography in the elderly. 2. Senile dementia: diagnosis and functional impairment.

Clinical, psychometric and computed tomographic (CT) data are presented on three groups of elderly subjects: 50 normals, 40 patients with senile dementia and 41 suffering from affective disorder. Demented subjects showed significantly more CT evidence of cerebral atrophy than non-demented subjects, but there was considerable overlap. Although patients with a history or clinical signs of cerebral infarction were specifically excluded, such infarcts were found moreoften in CT scans of the dementia subjects than in the others, particularly when the diastolic blood pressure was raised. When correlating cognitive impairment with CT changes, ventricular size emerged as more important in the dementia patients, in contrast to the controls, in whom cortical atrophy was related to lower scores on a cognitive test. Other interesting findings included an inverse relationship between cortical atrophy and paranoid delusions.

Aged↗
PubMed1980

Computed tomography in the elderly. 3. Affective disorder.

Clinical and computed tomographic (CT) data on a consecutive series of 41 elderly patients with affective disorders are presented, and comparisons made with a group of 50 healthy controls. In both groups ventricular size increased with age, but only in the controls was there an age correlation with sulcal widening. Using clinical and radiological criteria, the prevalence of cerebrovascular disease in the patient group was 12 per cent. A sub-group of patients with enlarged ventricles emerged, whose first depression began later in life, and who at the time of this study were older and showed more "endogenous" features than the remainder. It is suggested that this provides further evidence that organic cerebral factors may have aetiological significance in some depressions of old age.

Aged↗
PubMed1980

A new batch method of preparing intravenous piggyback solutions in polyvinylchloride containers.

The centralized preparation of large-volume parenteral and total parenteral nutrition solutions at the University of California Medical Center, San Diego, was expanded to include intermittent therapy admixtures for piggyback administration. Efficient methods were needed to prepare large quantities of admixtures daily. A batch system of preparation was designed and implemented using a new Intravenous Bag Filling Rack (IBFR). Safety and efficiency were maximized while utilizing a polyvinylchloride flexible intravenous bag system.

California↗
PubMed1980

HLA-DR epitope region definition by use of monoclonal antibody probes.

Definition of HLA-DR epitopes has been attempted by utilizing monoclonal antibody probes. Hybridoma antibodies L203 and L227, known to bind different epitopes on human Ia-like molecules, were tested for their ability to block cytotoxicity of monoclonal and allogeneic anti-DR antibodies. Monoclonal cytotoxic antibodies segregated into two groups: those more effectively blocked by L203, and those more effectively blocked by L227. Alloantisera also segregated into two groups, but according to their DR specificity. Anti-DR1, -2, and -3 alloantisera were effectively blocked by both L203 and L227, whereas anti-DR7, -w9, -w10, and MT1 alloantisera were not blocked by either. Blocking was not correlated with immunoglobulin class of the alloantibody and further definition of the mechanism of cytotoxicity blocking remains to be elucidated. Based on these data and prior binding and immunochemical studies with L203 and L227, a model is proposed in which the tertiary structure of each DR molecule, or complex of associated molecules on the cell surface, has two reference epitopes, one defined by L203, and another defined by L227. HLA-DR epitopes defined by the cytotoxic monoclonal or alloantibodies to the L203 or L227 epitope in order to begin epitope mapping or grouping.

Animals↗
PubMed1980

Two populations of Ia-like molecules on a human B cell line.

Evidence is presented for two populations of Ia-like molecules on the human B cell line Raji. Two monoclonal antibodies, L203 and L227, are described. Both recognize nonpolymorphic determinants on B cell antigens. Both immunoprecipitate 34,000- and 28,000-dalton material from 125I-labeled extracts of Raji, but L227 precipitates 25,000-dalton material as well. Immunodepletion experiments confirm that the antibodies react with two different populations of molecules.

Antibodies↗
PubMed1980

Immunoglobulin secretion by mouse X human hybridomas: an approach for the production of anti-idiotype reagents useful in monitoring patients with B cell lymphoma.

Tumor cells were obtained from a patient with nodular lymphoma, a monoclonal B cell malignancy. These non-Ig-secreting lymphoma cells were hybridized to mouse myeloma cells. Hybridomas secreting human Ig were obtained in high frequency. One clone, which was a stable producer of human heavy and light chains, but which had lost production of mouse light chains, was chosen for study. It secreted a human IgM pentamer. The Ig produced by this clone was purified and used as an immunogen for the production of anti-idiotype antibodies. These antibodies recognized the specific cell surface Ig of the lymphoma cells and have been used to detect idiotype-bearing cells in the blood of the original patient, even at times when the disease was in clinical remission. Moreover, free idiotype could be detected in the patient's serum. Both the levels of Id+ cells and free idiotype correlated with disease activity, rising in relapse and falling in remission.

Animals↗