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Biomedical subjects

A O Grubb

Publications and source records attributed to A O Grubb.

9 recordsLinked to original sources

Quantitation of gamma-trace in human biological fluids: indications for production in the central nervous system.

Gamma-Trace was purified in large amounts from urine and used for the production of a specific rabbit antiserum. An enzyme immunoassay for quantitation of gamma-trace was developed using the pure protein as a primary standard. Its sensitivity was approximately 30 microgram/l. An enzyme amplified single radial immunodiffusion was developed as well. Its sensitivity was approximately 0.3 mg/l. These assays allowed quantitation of gamma-trace in normal human biological fluids. The following results were obtained (mean +/- SD): cerebrospinal fluid: 5.8 +/- 2.2 mg/l, plasma: 1.1 +/- 0.42 mg/l, saliva: 1.8 +/- 0.88 mg/l and urine: 0.095 +/- 0.057 mg/l. Plasma samples from patients with advanced renal failure revealed gamma-trace values up to 13 times the normal mean plasma value. The results indicate a production of gamma-trace in the central nervous system and that the protein is primarily catabolized by the kidney.

Cerebrospinal Fluid Proteins

Many bacterial species bind human IgD.

Forty-four bacterial strains belonging to 19 species were tested for their IgD-binding capacity by incubation with radiolabeled human IgD. A high binding of IgD to Neisseria catarrhalis and Hemophilus influenzae and a moderate binding of IgD to streptococci of the groups A, C, and G were found. Two strains of N. catarrhalis were tested for their ability to bind selectively the IgD in normal pooled serum and in three serum samples with IgD M components and were found to possess this property. Binding studies with radiolabeled IgD Fab and Fc fragments indicated that the binding mainly but not exclusively involves the CH1 region of the IgD molecule.

Bacteria

Quantitation of J chain in human biological fluids by a simple immunochemical procedure.

The molecular form and immunochemical properties of the J chain populations released on reduction and carboxymethylation of normal human plasma, milk, saliva and of plasma containing IgA or IgM M-components were investigated. A procedure was devised to release the entire J chain population from these various sources and to produce immunochemically identical J chain populations containing only J chain monomers. An identical standard J chain population was purified and quantitated by physiochemical means. A specific rabbit anti-J chain antiserum was raised against this pure J chain population. A simple and rapid immunochemical method for J chain quantitation in complex biological fluids as well as in solutions of pure polymeric immunoglobulins was constructed on these grounds. The J chain concentration was found to be (mean +/- S.D.) 1.74 +/- 0.65 micron in normal human plasma, 1.94 +/- 1.21 micron in human milk and 0.48 +/- 0.26 micron in human saliva. The J chain/IgA molar ratio was found to be (mean +/- S.D.) 0.45 +/- 0.07 in human milk and 0.52 +/- 0.09 in human saliva when the IgA concentration was expressed as monomeric units per volume unit. The range of the J chain/IgA molar ratios in plasma samples with highly concentrated IgA M-components was 0-0.64. The J chain/IgM molar ratio in plasma samples with highly concentrated IgM M-components was between 1 and 2 when the IgM concentration was expressed as pentameric units per volume unit.

Amino Acids

Expression of protein HC on the plasma membrane of different human cell types.

The surface expression of a recently described plasma glycoprotein called human complex-forming glycoprotein, hetergeneous in charge (protein HC) on a number of different human cell types was investigated. By means of direct and indirect immunofluorescence, protein HC was shown to be associated with the surface of virtually all cells of the investigated normal cell types including erythrocytes, peripheral blood B and T lymphocytes, and the human fibroblast lines HE 81, HE 31, and WI 38. When transformed and malignant cell populations were studied, it was found that some populations (e.g., the T cell line Molt-4) carried protein HC on the surfaces of very few cells, whereas other cell populations (e.g., chronic lymphocytic leukemia lymphocytes) carried the protein on most cells. Malignant cell populations with intermediary percentages of protein HC-positive cells were also found. Protein HC on the cell surface of normal peripheral blood lymphocytes could be redistributed by incubation of the cells with anti-protein HC-antiserum at 37 degrees C, and this reaction could be inhibited by sodium azide.

Animals

A complex-forming glycoprotein heterogeneous in charge and present in human plasma, urine, and cerebrospinal fluid.

A glycoprotein from the urine of one healthy individual was purified by ultrafiltration, ion-exchange chromatography, gel chromatography and immunosorption. The protein contained only one polypeptide chain with an approximate molecular weight of 31 000 and was associated with a brown colour which did not disappear even after total reduction and alkylation of the protein followed by dialysis in 6 M guanidine hydrochloride. The protein appeared homogeneous on sodium dodecyl sulphate-polyacrylamide electrophoresis and gel chromatography. It had only one N-terminal amino acid sequence, Gly-Pro, and gave only one precipitate with a polyvalent antiserum but was found to be very heterorgeneous on agarose gel electrophoresis and on isoelectric focusing. Desialylation of the protein failed to alter this heterogeneity. An electroimmunoassay system was designed to measure the amount of the protein in normal human plasma, urine, and cerebrospinal fluid where the mean concentrations were found to be about 100, 10 and 0.3 mg/l, respectively. The protein was found to occur in normal plasma and urine as free monomers and dimers and as complexes with IgA and albumin.

Amino Acid Sequence

Immunofluorescent demonstration of the presence of protein HC on the surface of human lymphocytes.

Indirect immunofluorescence was used to demonstrate the presence of protein HC on the surface of a large percentage of normal human peripheral blood lymphocytes. Protein HC is a recently described charge heterogeneous, complex-forming glycoprotein normally present in human plasma, urine and cerebrospinal fluid. The synthesis of protein HC by lymphocytes was indicated by the removal of the glycoprotein from the cell surfaces on trypsinization of the cells followed by the reappearance of the protein on continued cultivation of the cells.

Cell Membrane

Immunochemical evidence for a common variable region in three immunoglobulin classes in the same individual.

One IgG1(kappa), one IgM(kappa), and one IgA1(kappa) monoclonal (M)-component were purified from one human serum. Rabbit antisera were raised against the IgG and IgM M-components and were absorbed until specific for idiotypic determinants on these molecules. All three M-components gave reactions of immunological identity when tested by double radial immunodiffusion with either of the two idiotype-specific antisera. Both heavy and light chains were isolated from each of the three M-components and all preparations inhibited formation of idiotypic precipitates. None of these preparations formed precipitates with idiotype-specific antisera alone. When heavy or light chains of one M-component were hybridized with light or heavy chains from the other M-components the resultant molecules precipitated with anti-idiotypic serum. Hybrids with chains from polyclonal IgG were not precipitable with such antiserum. These results indicate that the variable region of the heavy chains of these M-components of three different immunoglobulin classes are closely similar, if not identical.

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