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Biomedical subjects

J Gordon

Publications and source records attributed to J Gordon.

At least 37 records · Page 2Linked to original sources
PubMed1979

Chronic myelomonocytic leukemia with paraproteinemia but no detectable plasmacytosis: a detailed cytological and immunological study.

A patient with chronic myelomonocytic leukemia with IgG K paraproteinemia, but no detectable plasmacytosis, is described. The patient was entering a blastic phase at the time of the most detailed studies. Cytological, cytochemical, and ultrastructural studies revealed a mixed myeloid proliferation with granulocytic forms predominating over monocytic elements. A variety of ultrastructural abnormalities, including defective granulation, was observed but no cells with highly developed rough endoplasmic reticulum were observed. Immunological marker studies showed that the mature myeloid cells possessed receptors for the Fc of IgG and weakly expressed the Ia-like P29/34 antigen. The mature myeloid cells also expressed both surface and intracytoplasmic Ig restricted to IgG K, and this IgG K persisted after 4 weeks in culture. A reverse plaque assay showed that the myeloid cells were capable of releasing IgG K in vitro, but studies involving the incorporation of radio-labeled amino acids showed no detectable Ig production by the myeloid cells. The possible interpretations of these data are discussed in some detail in relation to previous reports of paraproteinemia in myeloid proliferative disorders.

Aged↗
PubMed1979

Cell separation with staphylococcal protein A immunoadsorbent surfaces.

An 'indirect" cell separation technique was developed using protein A, in which each specific antiserum was first reacted with the cells to be processed. Separation was then achieved on antibody/protein A immunoadsorbent surfaces, where the final antibody coupled to the protein A was one which was directed against the specific antisera previously reacted with the cells. Only small volumes of specific antisera were required to effect separation either on a small or large scale with excellent specificity, cell viability and total cell recoveries. Theoretically, the technique would function with any Ig class of specific antisera from any species and would not be restricted to mammalian protein A binding IgG specific antisera, allowing considerable expansion in the number of antisera able to be utilized.

Antibodies↗
PubMed1979

The B lymphocyte-deprived mouse as a tool in immunobiology.

The purpose of this article is to demonstrate that mice subjected to continuous injections with anti-IgM antibodies, initiated within one day of birth, or in adulthood, lose all their B lymphocyte functions, but retain T lymphocyte reactivity. The B lymphocyte status of these mice was analyzed by histology, radioautography, serum immunoglobulin levels, the antibody response and reactivity to LPS in vitro. T lymphocyte functions were evaluated in vivo by tumor allograft rejection, contact sensitization, and in vitro by reactivity to mitogens and allogeneic cells. On the basis of the results described, it is suggested that the anti-IgM-treated mouse may be considered as a balid and useful experimental model of the "T mouse".

Aging↗
PubMed1979

Multiple phosphorylation of ribosomal protein S6 during transition of quiescent 3T3 cells into early G1, and cellular compartmentalization of the phosphate donor.

At 5 min after quiescent cells are induced to enter G1 there is a large increase in the amount of 32P incorporated into 40S ribosomal protein S6. Here we show that changes in the specific activities of 32Pi and [gamma-32P]ATP in stimulated as compared to quiescent cultures do not account for this large increase. Instead, we demonstrate by decreased electrophoretic mobility on two-dimensional polyacrylamide gels that this increase is due to a quantitative increase in the total amount of phosphate incorporated into S6. Furthermore, pulse-chase experiments show that the phosphate that is incorporated into S6 is metabolically stable during at least the first 60 min of induction and that the incorporation of 32P into S6 responds immediately to the replacement of 32Pi by Pi in the medium, in contrast to [gamma-32P]ATP which changes very slowly. Thus, the S6 phosphate donor must be a compartment separate from that of the total cellular ATP.

Adenosine Triphosphate↗
PubMed1979

Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications.

A method has been devised for the electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets. The method results in quantitative transfer of ribosomal proteins from gels containing urea. For sodium dodecyl sulfate gels, the original band pattern was obtained with no loss of resolution, but the transfer was not quantitative. The method allows detection of proteins by autoradiography and is simpler than conventional procedures. The immobilized proteins were detectable by immunological procedures. All additional binding capacity on the nitrocellulose was blocked with excess protein; then a specific antibody was bound and, finally, a second antibody directed against the first antibody. The second antibody was either radioactively labeled or conjugated to fluorescein or to peroxidase. The specific protein was then detected by either autoradiography, under UV light, or by the peroxidase reaction product, respectively. In the latter case, as little as 100 pg of protein was clearly detectable. It is anticipated that the procedure will be applicable to analysis of a wide variety of proteins with specific reactions or ligands.

Animals↗
PubMed1979

Backstimulation by blastogenic factor in the primed LD typing test: possible role in anomalous responses.

The anomalous false-positive results often found in the primed lymphocyte typing (PLT) test seem to be partially due to the release of blastogenic factor (BF) from the stimulating cell, resulting in back stimulation of the primed lymphocyte. These anomalous responses can be greatly reduced by treating the stimulator cell with high doses of irradiation or with puromycin.

Cell Division↗
PubMed1979

A new purification scheme for elongation factor 1 from rabbit reticulocytes and investigation of the homology of the subunits with those of initiation factor 2.

The aim of this work was to compare the subunits of the elongation factor EF-1 and the initiation factor eIF-2 from rabbit reticulocytes. We devised a simple procedure for the purification of EF-1: stepwise chromatography on heparin-Sepharose, separation of the heavy form by sucrose gradient centrifugation, and a final step of stepwise chromatography on RNA-Sepharose. The heparin-Sepharose column also clearly separated EF-1 and EF-2 within one chromatographic step. The EF-1 was 350-fold puried and the yield was 10%. This preparation showed after electrophoresis on polyacylamide gels in the presence of sodium dodecyl sulfate three bands corresponding to those described by others as the subunits, with Mr of 54000, 49000 and 29200. An additional band of Mr 34000 was present but no others. The 49000-Mr and 34000-Mr bands corresponded exactly in molecular weight to two of three subunits of eIF-2. A more detailed comparison was therefore made of all subunits of EF-1 and eIF-2. This was done by examination of chymotryptic fingerprints on polyacrylamide gel electrophoresis. No evidence for homology between EF-1 and eIF-2 was found. However, the two larger subunits of eIF-2 had a majority of chymotryptic fragments in common, thus indicating some homology between these polypeptides.

Animals↗
PubMed1979

B-cell acute lymphatic leukaemia: immunoglobulin synthesis, morphology and clinical features.

A detailed case study of a B cell acute lymphocytic leukaemia (ALL) is described. Ultrastructurally the neoplastic cells resembled other cases of ALL studied. The majority of the neoplastic cells had detectable surface IgGlambda and receptors for Fcgamma while a majority of the cells had receptors for the C3 component of complement. Neoplastic cell preparations were able to synthesize IgGlambda with a surplus of free lambda chains. This case did not respond to treatment, and death ensued within 36 h of presentation. The clinical and laboratory findings are discussed with respect to other cases of ALL.

Adult↗
PubMed1979

Biosynthesis and characterisation of IgMlambda in a case of chronic lymphocytic leukaemia with intracellular immunoglobulin inclusions.

Lymphocytes from a patient with chronic lymphocytic leukaemia were found to contain crystalline inclusions in the cytoplasm. These crystals were characterised as IgMlambda immunoglobulin. The cells did not have detectable surface immunoglobulin. No paraprotein was detected in the serum and no excess of immunoglobulin was detected in the urine. The cells incorporated radioactive leucine into mu and lambda chains during an 18-hour culture. Studies of labelled lysate immunoglobulin revealed a molar excess of heavy chain over light chain while in contrast free light chain was the only detectable secreted immunoglobulin product during the culture period. These findings are discussed in relation to immunoglobulin synthesis by normal and other neoplastic lymphocyte preparations.

Aged↗
PubMed1978

N4-Acetylcytidine. A previously unidentified labile component of the small subunit of eukaryotic ribosomes.

The nucleoside content of 18 S rRNA from rat liver is determined under conditions known to prevent the destruction of chemically labile modified nucleosides. Two base-modified nucleosides, not completely identified before, are shown to be N6-methyladenosine and 7-methylguanosine. The results further demonstrate the presence of a hitherto unidentified component of 18 S rRNA whose spectra and chromatographic properties are identical with that of N4-acetylcytidine. In addition, this compound is not detectable in 28 S rRNA nor in 16 S rRNA derived from the small ribosomal subunit of Escherichia coli. However, it appears to be conserved in the small ribosomal subunit of eukaryotes, since it is also present in yeast 17 S rRNA and chicken liver 18 S rRNA.

Animals↗