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Biomedical subjects

A Grubb

Publications and source records attributed to A Grubb.

At least 163 records · Page 9Linked to original sources
PubMed1985

Human gamma-trace. Structure, function and clinical use of concentration measurements.

The discovery, tissue distribution, concentration in extracellular fluids and structure of human gamma-trace are reported. The use of determinations of the cerebrospinal fluid concentration of gamma-trace in the diagnosis of hereditary cerebral hemorrhage with gamma-trace-amyloidosis is described. The physiological function of gamma-trace as a cysteine proteinase inhibitor is accounted for an it is suggested that the six trivial names used for gamma-trace so far are replaced by the functional designation cystatin C.

Adult↗
PubMed1984

The place of human gamma-trace (cystatin C) amongst the cysteine proteinase inhibitors.

Native gamma-trace, a small basic protein present in high concentration in cerebrospinal fluid, semen and neuroendocrine cells, but of unknown biological function, is shown to be a potent inhibitor of the cysteine proteinases papain, ficin, and human cathepsins B, H and L. It proves to be the tightest -binding protein inhibitor of cathepsin B so far discovered. The name cystatin C is proposed for gamma-trace to reflect the many similarities in activity and structure to chicken egg-white cystatin and mammalian cystatins A and B. The inhibition constants of cystatin C, taken together with its widespread distribution in human tissues and extracellular fluids, suggest that a physiological function could well be the regulation of cysteine proteinase activity.

Cathepsins↗
PubMed1984

Feasibility of extracorporeal on-line large-scale plasma adsorptions on protein A-sepharose columns in cancer patients.

The feasibility of extracorporeal adsorption of 1.5-3 L plasma on protein A-Sepharose was investigated in six patients with advanced cancer. Anticoagulation with heparin was associated with respiratory distress syndrome in two patients, most likely caused by complement activation as indicated by a transient leukopenia during plasma reinfusion and appearance of C3 degradation products in the extracorporeal circulation. Addition of citrate abolished the respiratory symptoms, C3 degradation, and leukopenia, and no adverse reactions were observed. No objective tumor regression was observed in any of the patients. Three patients progressed during therapy. In one of these, multifocal central tumor necrosis was observed as a possible, although unproven, therapeutic effect. Increased natural killer and/or killer cell activities were recorded in three patients and increased complement-dependent serum cytotoxicity in one patient. The level of circulating immune complexes decreased significantly (18-28%) in three patients studied. It is concluded that extracorporeal plasma adsorption on protein A-Sepharose is feasible when citrate is added to the extracorporeal system, but its therapeutic efficacy is uncertain.

Adsorption↗
PubMed1984

Human immunoglobulin class and subclass specificity of Fc receptors induced by herpes simplex virus type 1.

Herpes simplex virus is known to induce an immunoglobulin-binding cell surface receptor in infected cells that utilizes a nonimmune mechanism. In the present paper, we report the immunoglobulin class and subclass specificity of this receptor. Of the human immunoglobulins G(IgG), IgA, IgM, and IgD, as well as the structurally related beta2 microglobulin, only IgG and its Fc portion exhibited an increased binding to herpes simplex virus-infected cells versus uninfected control cells. The IgG subclass specificity of the Fc receptor was studied in 37 radioiodinated IgG myeloma proteins representing all four subclasses. We found that IgG3 myeloma proteins did not bind to herpes simplex virus-infected cells to a greater extent than to uninfected cells. On the contrary, proteins belonging to the other subclasses exhibited an increased binding to herpes simplex virus-infected cells of the following relative magnitude: IgG4 greater than IgG1 greater than or equal to IgG2. This increment of binding could be abolished by addition of a large excess of human IgG Fc fragment. Evidence for the existence of a variable herpes simplex virus-specific binding ability between myeloma proteins belonging to the same IgG subclass was also obtained. Furthermore, we tested two other herpes simplex virus type 1 strains with a limited number of myeloma proteins with very similar results as with the herpes simplex virus type 1 F strain. Several sources of experimental artefacts were controlled, including the state of aggregation of the test proteins, the functional integrity of the Fc portion before and after radioiodination, and the subclass assignments. The implications for the biological role of the Fc receptor of herpes simplex virus are discussed.

Animals↗
PubMed1983

Occurrence of gamma-trace in the calcitonin-producing C-cells of simian thyroid gland and human medullary thyroid carcinoma.

gamma-Trace, a microprotein occurring in neuroendocrine cells, was demonstrated by immunohistochemical technique to be present in the calcitonin-producing C-cells of normal simian thyroid gland and of human medullary thyroid carcinoma. A comparatively high concentration of gamma-trace was demonstrated in tissue extract of neoplastic C-cells. The immunoreactive protein found in the extract had a molecular weight and electrophoretic mobility characteristic for gamma-trace.

Adsorption↗
PubMed1982

Human gamma-trace, a basic microprotein: amino acid sequence and presence in the adenohypophysis.

The amino acid sequence of human gamma-trace, a basic microprotein without known function, was determined by automated Edman degradations of the carboxymethylated polypeptide chain and of fragments obtained by cyanogen bromide treatment and tryptic digestion after blocking of lysine residues. The single polypeptide chain contained 120 residues, and the calculated Mr was 13,260. A proline residue at position 3 was partly hydroxylated. The presence of gamma-trace in a significant proportion of the cells in the anterior lobe of simian and human pituitary glands was demonstrated by immunohistochemical procedures with a rabbit antiserum against human gamma-trace. The tissue localization and amino acid sequence of gamma-trace indicated that this protein is connected with the peptidergic gastroenteropancreatic neuroendocrine system.

Adrenocorticotropic Hormone↗
PubMed1982

Isolation and some properties of an IgG Fc-binding protein from group A streptococci type 15.

An IgG Fc-binding protein was isolated from alkaline extracts of group A streptococci type 15 by ion-exchange chromatography and immunosorption on an IgG column. Ample use of protease inhibitors was necessary to achieve successful isolation. 600 micrograms protein was obtained from 60 g bacteria (wet weight). The protein appeared homogeneous on agarose gel and sodium dodecyl sulfate polyacrylamide gel electrophoresis and had an apparent molecular weight of 29,500. It contained appreciable amounts of the amino acids glutamic acid, alanine, leucine, aspartic acid and lysine, but little or no tyrosine, phenylalanine, proline, glucosamine or galactosamine. It precipitated human monoclonal IgG of all four sub-classes in agarose gels as well as polyclonal IgG, IgG Fc and normal human serum. It did not precipitate IgG Fab, IgA, IgM, IgD or free kappa or lambda chains.

Amino Acids↗
PubMed1982

A simple modification of Greiner electronics selective analyser G300 permitting use of capillary blood samples.

A simple modification of Greiner electronics selective analyser G300 allowing direct transference of serum samples to the process tubes is described. The modified instrument permitted use of pediatric and capillary blood samples. Eight different capillary analyses were tested on the modified instrument and the results agreed with those obtained by the ordinary analytical macroprocedures of the instrument.

Automation↗
PubMed1981

Isolation and partial characterization of a low molecular weight trypsin inhibitor from human urine.

A low molecular weight glycoprotein which completely inhibited trypsin at a 1 : 1 molar ratio was isolated from human urine. It was generated from a precursor molecule which in turn derived from plasma inter-alpha-trypsin inhibitor. It had one polypeptide chain with a molecular weight of about 20 000 and a high content of half-cystine residues. Its amino-terminal amino-acid sequence was Val-Thr-Glu-Val-Thr-X-Leu-Glu-Asp-.

Alpha-Globulins↗
PubMed1980

Demonstration of separate receptors for human IgA and IgG in group A streptococci type 4. Separation of the solubilized receptors from group- and type-specific antigens, lipoteichoic acid and peptidoglycan.

The alkaline extract of group A streptococci type 4 was separated by electrophoresis and diffused against 27 normal human sera. One of the precipitates appeared with 85% of the sear. Addition of purified IgA myeloma protein or sera containing IgA M-components to the extract changed the electrophoretic mobility of the precipitate anodically. Purified IgG Fc-fragments or sera containing IgG M-component did not affect the mobility of the precipitate. It was concluded that this precipitate contained the streptococcal receptor for human IgA. A non-precipitating IgG Fc-receptor, with agglutinating capacity for cells coated with human IgG1 but not IgG3, was localized by preparative electrophoresis to the same electrophoretic region as the IgA receptor. The mobility of the IgG receptor remained unaltered on addition of IgA myeloma protein permitting a separation of the two receptors by preparative electrophoresis. The receptors were distinct from the group specific carbohydrate, peptidoglycan and lipoteicholic acid. No M antigen or opacity factor were demonstrated in the extract.

Antigens, Viral↗
PubMed1980

Bacteria-immunoglobulin-lymphocyte interactions--new aspects.

Of 30 bacterial species tested 18 stimulated DNA synthesis in human blood lymphocytes. The maximum response was after 3-4 days of culture suggesting a mitogenic effect. This was confirmed by the induction of polyclonal antibody production shown by a plaque assay. Most bacterial species increased the DNA synthesis in B-enriched lymphocytes and unseparated lymphocytes but had negligible activity on T-enriched lymphocytes. Among bacteria with a mitogenic effect and ability to induce polyclonal antibody production are Staphylococcus aureus, Haemophilus influenzae, Mycobacterium tuberculosis, Neisseria gonorrhoeae, Streptococcus group A and Streptococcus pneumoniae. In an attempt to define structure (s) on the B-lymphocyte surface responsible for the lymphocyte stimulation the binding of IgD, IgM, and HLA-A, -B and HLA-D antigens to different bacterial species was investigated. A high IgD binding to N. catarrhalis and H. influenzae and a moderate binding of IgD to streptococci was found. Binding studies employing radiolabelled IgD Fab- and Fc-fragments indicated that the binding probably involves the CHl-region of the IgD molecule. Three purified radiolabelled myeloma IgM M-components were all shown to be efficiently bound to many bacteria indicating that a part of the IgM molecule other than the antigen-combining site can be involved in attachment to bacteria. Highly purified detergent-solubilized HLA-A, -B and HLA-D antigens, when separately incorporated into liposomes, were bound efficiently to two strains of N. catarrhalis and to one strain of H. influenzae weakly to one strain of E. coli, but not at all to another strain E. coli. Preliminary experiments indicate that these bacteria-immunoglobulin and bacteria-HLA-antigen interactions lead to lymphocyte stimulation.

Bacteria↗
PubMed1979

Interaction of the Fc part of IgG with Lancefield extracts of hemolytic streptococci. Strain specificity and activity.

Lancefield extracts of 19 types of group A streptococci as well as one group C and one group G strain were examined for agglutination of human red cells coated with various anti-Rh antibodies. Fourteen extracts agglutinated one or more of the coated cell samples, while five did not. The agglutination was inhibited by Fc but not by Fab fragments of human IgG. After mouse passages, three of the non-agglutinating strains acquired agglutinating capacity. At least three different reactivities were distinguished by the action of the extracts on IgG1 and IgG3 coated cells, respectively. Two of the streptococcal extracts, agglutinating the same anti-Rh coated cells, could be further differentiated in hemagglutination inhibition (HAI) experiments using purified IgG3 myeloma proteins. Five selected agglutinating systems were inhibited by purified myeloma proteins of the IgG1, IgG2, and IgG4 subclasses. IgG3 proteins inhibited only two of the five HAI systems.

Antibodies, Bacterial↗
PubMed1979

Demonstration of the non-identity between the Fc receptor for human IgG from group A streptococci type 15 and M protein, peptidoglycan and the group specific carbohydrate.

After electrophoresis of an alkaline extract of type 15 group A streptococci, three main precipitation lines were obtained in diffusion experiments against commercial human polyclonal IgG (lines 1, 2 and 3). Nineteen of 23 sera (83%) from apparently healthy human individuals gave line 3, while 6 of them (26%) gave line 1. The sera giving line 1 did also give line 3. Line 2 was obtained with 2 sera only, also giving lines 1 and 3. Line 3 was caused by a streptococcal Fc-receptor for human IgG, since the line could be displaced by addition of Fc-fragments, but not Fab-fragments of pooled human IgG. Line 1 was shown to be different from line 3, since (1) line 1 was suppressed in contrast to line 3 on absorption of a human serum or commercial polyclonal human IgG with S. aureus; and (2), line 1 was suppressed by Fab-fragments but not Fc-fragments of polyclonal human IgG. Line 2 could be inhibited by addition of peptidoglycan to commercial polyclonal human IgG or a human serum investigated. Another line, 4, obtained in diffusion experiments involving electrophoretically separated alkaline extract of type 15 group A streptococci was type-specific as shown by rabbit antisera to streptococci type M1, M8, M15, and T44, and disappeared on trypsinization of the extract. The component responsible for line 4 in the streptococcal extract, judged to be type-specific M protein, had a mobility different from the component responsible for line 3 in electrophoresis.

Bacterial Proteins↗
PubMed1978

Production of protein HC by human fetal liver explants.

Human fetal lever explants were found to secrete protein HC into the medium in molar amounts comparable to those of albumin, alpha 1-antitrypsin and orosomucoid. Incorporation of a radioactive amino acid from the medium into the secreted protein HC demonstrated de novo synthesis. The secreted protein HC had the same size and electrophoretic mobility as protein HC of plasma and urine and gave a reaction of immunochemical identity with the protein in these biological fluids.

Alpha-Globulins↗