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Biomedical subjects

R Levy

Publications and source records attributed to R Levy.

At least 775 records · Page 43Linked to original sources
PubMed1978

Antibody against megakaryocytes in idiopathic thrombocytopenic purpura.

Purified human IgG from both serum and the culture of human splenic cells was radiolabeled with 125I. Incubation of radiolabeled IgG from patients with idiopathic thrombocytopenic purpura (ITP) with normal homologous platelets or bone marrow cells resulted in significant (P less than .001) binding when compared with control IgG. Radioautographs showed that the radioactivity was associated with the platelets or megakaryocytes. The antiplatelet antibody in ITP has specificity for antigens associated with both platelets and megakaryocytes and suggests that thrombopolesis may also be affected in this disease.

Animals↗
PubMed1978

[The rheumatoid rosette test in bacterial endocarditis. A non-specific test for inflammation (author's transl)].

The rheumatoid rosette test was performed in 33 patients with febrile valvular cardiopathy. In 19 cases bacterial endocarditis was proved by blood culture or by histological examination. The test was positive in 3 cases out of 5 during the first ten days of the fever (group A1), in 6 cases out of 6 after the tenth day (group A2), and in 4 out of the 8 already treated patients (group A3). In 3 positive cases, successive measurements, before and during treatment, showed a rapid fall in rosette levels. In controls patients, the test was positive 8 out of 9 cases with febrile valvular cardiopathy without endocarditis (group B) and in 5 out of 5 cases in which bacterial endocarditis was probable but not proved (group C). The increase in rheumatoid rosette levels seems therefore to be non specific of bacterial endocarditis. Nevertheless it could be a good test for biological activity of the disease in treated patients. The origin and signification of the rheumatoid rosette forming cells are discussed.

Endocarditis, Bacterial↗
PubMed1978

Immunopathology of follicular lymphomas. A model of B-lymphocyte homing.

To investigate whether follicular lymphoma has a monoclonal origin, we stained frozen tissue sections from 22 afflicted patients for kappa and lambda light chains with an immunofluorescence technic. F(ab')2 antibody fragments were used to avoid binding by Fc receptors. In 20 cases the lymphoma nodules comprised a monoclonal population of immunoglobulin-producing cells. The nodules were usually surrounded by a normal, polyclonal population of B lymphocytes. Reactive lymphoid follicles were easily differentiated from lymphoma nodules on the basis of clonality. Eight cases contained multiple immunoglobulin heavy chains. All the lymphoma nodules in the same tissue or in multiple tissues in the same patient showed identical light-chain and heavy-chain staining even if different histologic subtypes were identified. Follicular lymphoma is the outgrowth of a single clone of immunoglobulin-bearing cells that retain the tissue-homing characteristics of B lymphocytes.

B-Lymphocytes↗
PubMed1978

Inhibition of conjugation in Tetrahymena pyriformis by cerulenin. Possible requirement for de novo lipid synthesis.

Conjugation in Tetrahymena pyriformis is induced by the mixing of two starved complementary mating types. Addition of the antibiotic cerulenin, a specific inhibitor of de novo lipid synthesis, upon mixing of the mating types inhibited the conjugation process. The inhibition of conjugation was found to be reversible upon washing the cells. Cerulenin inhibited [14C]acetate incorporation into the lipid fraction of the cells, while it did not affect the incorporation of [3H]leucine into proteins. Analysis of the fatty acid composition of the whole cells revealed that during conjugation the ratio of saturated to unsaturated fatty acids is markedly changed. While the ratio of saturated:unsaturated fatty acids is 0.30 in unconjugated cells, it reached a value of 0.45 in conjugated cells.

Animals↗
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↗
PubMed1978

The lymphoid system. Its normal architecture and the potential for understanding the system through the study of lymphoproliferative diseases.

This article presents a view of lymphoid tissue architecture as defined by the traffic of defined lymphoid cell classes. The compartmentalization of lymphocytes is discussed in reference to specific cell-cell interactions that occur in antigen-driven immune responses. Finally, the distribution of normal and neoplastic lymphocytes in humans is defined and compared with animal model systems.

Animals↗
PubMed1978

Evaluation of cardiac arrests managed by paramedics.

The effectiveness of cardiac resuscitations by Cincinnati paramedics was monitored for one year. The outcome of every arrest was assigned to one of four categories: dead on arrival, died in the emergency department, died in the hospital or discharged alive, and each patient was followed until death or discharge from a hospital. Of the 147 people in the study group, 22 left the hospital alive, a long-term success rate of 15%, and another 26 died during hospitalization, 18% of the study population. This data is comparable to success rates reported by other prehospital care systems. Furthermore, this data indicates approximately 15% of people who have cardiac arrests outside of a hospital can survive through prompt intervention by trained personnel.

Adolescent↗
PubMed1978

Psychological test performance and sedation thresholds of elderly dements, depressives and depressives with incipient brain change.

As expected, dements, depressives and patients with a mixed psychopathology were differentiated from one another on the sedation threshold measure and on a number of psychological tests. In depressives responding to treatment significant changes in physiological and psychological measures, which had been reported in an earlier study could not be replicated except for an increase of psychomotor speed. In the present sample of patients there were significant correlations between various psychological measures and between them and the levels of the sedation threshold, suggesting that sedation thresholds and psychological tests measured related cerebral functions. Evidence obtained from the earlier investigations to the effect that cerebral age changes short of those occurring in dementia may facilitate the occurrence of depression in late life was only weakly confirmed by the replication study.

Aged↗
PubMed1978

Rescue of immunoglobulin secretion from human neoplastic lymphoid cells by somatic cell hybridization.

B leukemia cells from four different patients were hybridized with a mouse myeloma cell line with polyethylene glycol as a fusing agent. The original leukemia cells all expressed immunoglobulin on their surface, but failed to secrete it. Over 200 different human-mouse somatic cell hybrids were obtained; 57% of them secreted human immunoglobulin in large amounts. Human immunoglobulin secretion can be a stable property of these hybrid cells over months of continuous culture. In each case the human immunoglobulin secreted was restricted to the light chain type expressed by the parental B leukemia cell. In addition, these hybrid cells secreted the original mouse myeloma protein and a variety of mixed human-mouse immunoglobulin molecules.

Animals↗
PubMed1978

Measuring client gains from staff-implemented programs.

Confidence in the adequacy with which staff implement training programs requires an analysis of the impact on the client. In two experiments, measures, were devised to reflect this impact. In the first, a measure of the consistency with which clients participated in a toilet-training program revealed their participation to be erratic. Consistent participation occurred after a public display of the consistency of participation was introduced. In Experiment II, detailed measures were devised to reflect the client's performance during the implementation of two physical-therapy programs: range-of-motion and ambulation. Additionally, standardized measures of the benefits that accrued from their participation in these programs were devised. Improvements in both measures were slight and unstable during a condition of immediate feedback (supervisor praise) to staff but substantial improvements were obtained with the addition of a public display of the client's performance.

Achievement↗
PubMed1978

A study of lymphoproliferative diseases comparing immunofluorescence with immunohistochemistry.

Sections of lymph nodes from patients with lymphoproliferative disorders were stained by immunofluorescence and immunoperoxidase methods. Staining with anti-kappa and anti-lambda antibodies employed F(ab')2 fragments of purified antibodies to avoid binding via Fc receptors. Frozen-section immunofluorescence revealed that B-cell lymphomas were composed of monoclonal populations of Ig-bearing cells. With immunohistochemical technics, however, a significant number of B-cell lymphomas either did not stain for Ig or showed spurious staining. The possible reasons for lack of staining in some cases and spurious staining in others are discussed. As currently applied to lymphoproliferative disorders, immunofluorescence appears to be more senitive and more speific than immunohistochemistry.

Cell Transformation, Neoplastic↗
PubMed1977

[Malignant lymphopathy in a patient suffering from acute disseminated lupus erythematosus (author's transl)].

The authors report a case of acute disseminated lupus erythematosus in a 55 years old patient, receiving small doses of corticosteroids, progressing over three years. During an acute exacerbation of the disease, the development of a cervical adenopathy led to a biopsy. Histological examination revealed a lymphocytic type malignant proliferation (centro-follicular lymphoma). This case is compared with findings reported in the literature and leads to a discussion of the relationship between ADLE and malignant disorders due to a disturbance of immune control mechanisms and the possible role of immune-depressant therapy in their onset.

Chlorambucil↗