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Biomedical subjects

G Spira

Publications and source records attributed to G Spira.

At least 55 records · Page 3Linked to original sources
PubMed1983

Lymphocyte subpopulations in benign monoclonal gammopathy.

Peripheral blood samples from normal individuals and from patients with benign monoclonal gammopathy or multiple myeloma were separated and assayed by immunofluorescence and rosette formation for T, B, TG and TM subpopulations. When compared with normal individuals and multiple myeloma patients, the benign monoclonal gammopathy patients could be divided into 2 groups. The 1st group demonstrated a T/B ratio similar to normal individuals, whereas in the 2nd group the ratio resembled that of the myeloma patients, with a decrease in the fraction of T lymphocytes, accompanied by an increased number of B lymphocytes. An analysis of the monoclonal Ig fraction levels indicated that the 2 groups differ in this respect as well. In the 1st group, the level of the monoclonal immunoglobulin was stable, with small fluctuations. The 2nd group demonstrated a general increasing M-component, especially in the 4-6 months preceding the study. The 2 benign monoclonal gammopathy groups exhibited a trend to a lower TM/TG ratio compared to normals; this change is more prominent in the 2nd group. Analysis of the T lymphocyte subpopulations indicated an overall decrease in the fraction of TM multiple myeloma. The above-mentioned parameters might thus aid in discriminating among BMG patients with regard to their tendency towards a malignant transformation.

B-Lymphocytes↗
PubMed1982

A sensitive method for detecting cells coated with antibodies with human monoclonal rheumatoid factor produced in vitro.

A human monoclonal rheumatoid factor (RF) produced in vitro by an Epstein-Barr virus immortalized cell line has been used to detect and quantitate antibodies specifically bound to cells. The RF is purified from cell culture supernatant by a simple procedure and then radiolabeled. In this assay, the binding of 125I-labeled RF to cells coated with specific antibodies is determined. This RF method detects very low titers of antibodies directed against specific cellular antigens and also minorities of antibody coated tumor cells in mixtures with identical non-coated cells. The advantages of this unique human monoclonal antibody are discussed.

Animals↗
PubMed1982

Truncated mu chain in a Burkitt lymphoma line (P3HR-1) and its fate in various hemapoietic somatic cell hybrids.

Hybrids obtained by the fusion of PUT, an ouabain and TG-resistant subline of the Burkitt lymphoma(BL)-derived P3HR-1 line, with hemopoietic cells of various differentiation types were tested for their membrane and intracellular immunoglobulin expression. PUT cells carry no membrane immunoglobulin, but contained intracellular 61K mu chain and kappa chain. The PUTKO-1 hybrid, derived from the fusion of PUT with the erythroleukemia line K562 contains no detectable immunoglobulin. NAMPUT, a hybrid between PUT and the IgM-lambda-producing BL line Namalwa, synthetizes cellular mu, lambda and kappa chains, but its surface-Ig is exclusively mu-lambda. Two different mu chains could be detected, both precipitated by either anti-mu or anti-lambda sera. Immunoprecipitation with anti-kappa precipitated neither kappa nor mu. PUTRAL was derived by fusing PUT with Rael, an unusual surface-IgG-lambda-carrying BL line. In this hybrid, the ability to synthesize gamma and lambda chains has been eclipsed, but two mu chains are present: one corresponding to the truncated 61K chain of PUT, and a normal-sized 74K. Between 20 and 30% of the cells stain for surface IgM.

Autoradiography↗
PubMed1981

Membrane-bound and cellular immunoglobulins in human B-lymphoma lines and derived hybrids.

Hybrids derived from the fusion of cell lines representing different maturation stages were studied for their membrane and cellular immunoglobulin expression. The hybrids can be subdivided into 3 groups, with one common parental line in each group. In the first group, Raji cells represent the common parent: it contains small amounts of membrane and cytoplasmic mu (mu) and kappa (kappa) chains. In the second group, PUT is the common parent, an ouabain and TG-resistant subline of the BL-derived P3HR-1 line. PUT contains a truncated intracellular mu chain. The third group consists of hybrids between K562, an EBV-negative human erythroleukemia line and 2 different BL lines. Membrane-immunoglobulin expression was intermediate between the parental lines in the first two groups derived from the fusion of 2 BL lines. In the third group, hybridization with the K562 cell suppressed the membrane-Ig expression of the B-cell partner. Total cellular immunoglobulin determinations showed that some cells synthesized light chains in excess of heavy chains, others contained an excess of heavy chains, while still others had equal amounts of heavy and light chains. The hybrids showed a variety of patterns, including amplification of the parental phenotypes, appearance of new phenotypic combinations, and eclipse of one or both parental phenotypes. A comparison of the total and the membrane-associated immunoglobulin patterns suggests independent handling of intracellular and membrane immunoglobulin synthesis.

B-Lymphocytes↗
PubMed1981

Spontaneous immunoglobulin changes in human plasma-cell dyscrasia.

A series of spontaneous changes affecting the nature of the immunoglobulin secretion of plasma cels is described in a patient initially diagnosed as IgG lambda benign monoclonal gammopathy. After several years a slight increase in the amount of serum monoclonal immunoglobulin occurred; shortly thereafter an aggressive form of multiple myeloma was diagnosed. Unexpectedly a rapid spontaneous decrease of the monoclonal immunoglobulin, accompanied by the appearance in the serum of increasing quantities of a complex containing intact lambda light chains, then occurred. Concomitantly a fragment of the corresponding free light chain was was detected in the urine. A parallel is drawn between the facts observed in this patient and in an animal model recently proposed to explain the different types of structural immunoglobulin abnormalities in multiple myeloma.

Female↗
PubMed1981

Cell-surface immunoglobulin and insulin receptor expression in an EBV-negative lymphoma cell line and its EBV-converted sublines.

Membrane Ig and insulin receptors were assayed in the EBV-negative Ramos lymphoma line and its EBV-converted sublines by surface fluorescence. 125I-protein A-binding assay, immunoprecipitation, and insulin receptor assay. The original Ramos line expressed surface IgM but not IgD and had a low concentration of insulin receptors. Ten of 10 converted lines expressed IgD and a variable but usually high insulin-binding capacity. Molecular weight analysis of immunoprecipitated Ig showed the presence of 2 mu-chains and 2 delta-chains. One of each heavy chain type could be characterized as membrane Ig, whereas the other was cytoplasmic. Antisera against the lambda-chain precipitated mu and delta heavy chains as well, indicating that the delta-chain expressed on the membrane of the EBV-converted Ramos lines is bound to the lambda light chain. The results show that the differentiation of a Burkitt lymphoma line is not completely "frozen" and can be induced to change in a more "activated" direction by EBV conversion.

Binding Sites↗
PubMed1980

A calcium binding IgG myeloma protein.

A calcium binding IgG was isolated and purified by column chromatography from serum of a myeloma patient with asymptomatic hypercalcaemia. The myeloma IgG, characterized as an IgG kappa, revealed a normal sized heavy chain (56 000 dalton), and a light chain of 31 000 dalton. Another population of IgG separated and purified from the same patient's serum did not bind calcium and had a normal 26 000 dalton light chain. Calcium binding activity in vitro is optimal at pH 8.0, and reaches its maximum after 3 h of 45Ca myeloma IgG incubation. Cleavage of the purified IgG by trypsin yielded peptides which were further isolated by column chromatography and characterized as Fab and Fc fragments. Light and heavy chains were obtained by reacting the immunoglobulin with dithiothreitol and iodoacetamide followed by Sephadex G-100 chromatography. Calcium binding activity was proved to be associated with Fab IgG fragment. Preparates containing Fc, heavy or light chains did not bind calcium in vitro.

Calcium↗
PubMed1979

Immunoreactive somatomedin B in acromegaly and in Turner's syndrome.

Serum somatomedin B was measured by radioimmunoassay in forty-seven normal subjects, twenty-nine patients with acromegaly before and twenty-four after treatment, and eighteen patients with Turner's syndrome. Somatomedin B levels were significantly elevated in untreated acromegaly and in Turner's syndrome compared with the control group; they decreased following treatment of acromegaly. Because of the overlap between the groups, little information could be obtained from single somatomedin B estimations, which could, therefore, not replace dynamic tests of growth hormone secretion. No correlation between growth hormone and somatomedin B in acromegaly was detected; however, somatomedin B appeared to be related to the insulin response during the oral glucose tolerance test. In Turner's syndrome, no relationship between somatomedin B and insulin production, urinary oestrogen excretion, growth hormone secretion, gonadotrophin levels, age or height was found. The reason for the raised somatomedin B levels in Turner's syndrome remains at present unknown.

Acromegaly↗
PubMed1978

Simultaneous production of mouse endogenous virus and Rous sarcoma virus by Schmidt-Ruppin virus infected mouse cells.

Schmidt-Ruppin Rous sarcoma virus infected chick cells injected into newborn C3H/f mice gave rise to tumours at the site of inoculation. These tumours were transplantable in adult C3H/f mice and were able to induce tumours in the wing of adult Leghorn chickens. Tumour cells from the 18th passage in mice were used to establish a cell line in tissue culture (C3HSR). These cells released C-type virus particles that produced foci and were able to propagate in chick cells. Cloning of the C3HSR cells demonstrated that the same cell expressed both avian and murine antigens. Mouse cells infected with virus released by C3HSR cells produced murine leukaemia virus-like particles as revealed by the reverse XC syncytial test and by immunofluorescence tests.

Animals↗
PubMed1976

Radioimmunossay for detection of antigen and antibodies to Newcastle disease virus.

When Newcastle disease virus (NDV) is treated with NP-40 and ether a membrane fraction of 150,000 m.w. is obtained. This fraction which is composed of two polypeptides with m.w. of 56,000 and 76,000 was used in a radioimmunoassay (RIA). The assay was developed for both antigen and antibody and was found to be reproducible, specific, and highly sensitive. Titers of 1:51,200 were determined by RIA as compared to 1:4 by agar gel diffusion and 1:200 by hemaglutination inhibition (HI). As little as 5 ng of viral protein were detected by RIA inhibition technique. Labeled antigen could be stored in the presence of serum, KCI and Triton X-100 at -20 degrees C for as long as 6 weeks and retained similar reactivity as fresh reagent.

Animals↗
PubMed1975

Radioimmunoassay of human serum antibody specific for adenovirus type 5-purified fiber.

A radioimmunoassay (RIA), utilizing a second antibody to separate immune complexes, was developed to provide a sensitive and specific measure of serum antibody to adenovirus type 5 (Ad 5) fiber. Purity of fiber antigen was ascertained by sodium dodecyl sulfate urea-polyacrylamide gel electrophoresis and isoelectric focusing in ampholyte pH gradients. After labeling with 125I to high specific activity, the iodinated fiber did not exhibit loss of antigenic reactivity and remained stable for 3 weeks when stored at minus 20 degrees C with supplemental protein. Rabbit anti-Ad 5 serum with a neutralization titer of 1:320 precipitated 50% of the labeled fiber at a serum dilution of 1:50,000 when tested by the RIA. In competition assays as little as 0.5 ng of unlabeled fiber per millimeter was sufficient to inhibit the 125I fiber-antibody reaction. Serum specimens from 20 volunteers, obtained before and after vaccination with purified Ad 5 fiber or hexon subunit vaccine, were tested by RIA, hemagglutination-inhibition (HI), and neutralization tests. A comparison of mean antibody titers of post-inoculation sera showed that the RIA was 300 and 1000 times more sensitive than the HI and neutralization tests, respectively. Moreover, 19 of the men who were negative by the standard serologic tests before vaccination were shown to have anti-fiber antibody, with a mean RIA titer of 1:1028. Specificity of the RIA was demonstrated by the lack of an increase in antibody to Ad 5 fiber among those individuals vaccinated with the hexon subunit. Thus, the development of a highly sensitive and reproducible RIA allows for the detection of antibody specific for the Ad 5 fiber in serum which contains antibodies to the different virion antigenic determinants associated with Ad 5.

Adenoviridae↗