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Biomedical subjects

J C Jensenius

Publications and source records attributed to J C Jensenius.

At least 127 records · Page 7Linked to original sources
PubMed1984

Semi-automatic analysis of proteins and protein complexes by automated enzyme immunoassay after separation by high-performance gel-permeation chromatography. Size distribution of C3-IgG complexes.

Enzyme immunoassay (ELISA) was applied in the establishment of an immunological method for the characterization of column effluents. Serum samples, containing aggregated immunoglobulin (IgG), were separated by high-performance gel-permeation chromatography on a TSK column and fractions were collected directly in 96-well ELISA microplates. IgG was determined on anti-IgG-coated plates, followed by development with biotin-labelled anti-IgG and enzyme-labelled avidin. Complement factor C3 was determined on anti-C3-coated plates, developed with biotin-labelled anti-C3 and enzyme-labelled avidin. Complexes between IgG and complement factor C3 were determined on anti-IgG-coated plates, developed with biotin labelled anti-C3 antibody and enzyme-labelled avidin. Complex formation between C3 and IgG after incubation of serum with aggregated IgG was demonstrated. The methodology described is generally applicable to the analysis of biological components and is uniquely useful for the analysis of complexes between different components.

Animals↗
PubMed1984

Association of circulating immune complexes with glomerular proteinuria in patients with transitional cell carcinoma of the urinary bladder.

The presence of circulating immune complexes and the correlation between the amount of immune complexes and glomerular proteinuria was studied in 20 patients with urothelial bladder tumors followed by cystoscopies for 6-18 months. Circulating immune complexes, measured by the PEG-CC, PICRIA and C1q-ELISA assays, occurred more frequently in cases with residual or recurrent tumors than without tumors, and most frequently in cases with large tumors and a high grade of malignancy. Glomerular proteinuria, defined as the increased relative clearance of albumin, transferrin and haptoglobin, occurred in almost all cases with increased immune complex concentrations. Both glomerular proteinuria and the severity of proteinuria was significantly related to the immune complex concentration.

Adult↗
PubMed1984

Immune complex formation analysed by high-performance size exclusion chromatography (HPLC-SEC) using either 125I-labelled antigen or enzyme-linked immunosorbent assay (ELISA) for detection.

A physical/immunochemical method has been developed for the analysis of soluble immune complexes. Human serum with high amount of antibody against bovine serum albumin (BSA) was incubated at 37 degrees with a wide range of 125I-labelled BSA and separated according to size by high-performance size exclusion chromatography (HPLC-SEC) on a TSK G 6000 PW column. Fractions were collected onto microplates and analysed either by gamma counting or by an enzyme-linked immunosorbent assay (ELISA) technique detecting anti-BSA antibody. The size of the immune complexes were the same when analysed by the two methods. The heaviest immune complexes were seen in moderate antibody excess where the majority of the complexes were eluted in a broad peak around Mr of 7 X 10(6). In large antibody excess the immune complexes eluted at around 3 X 10(6). Around equilibrium two peaks were seen corresponding to 3 X 10(6) and 5 X 10(5). In antigen excess the peak at 3 X 10(6) is diminished and free antigen appears. No changes in the distribution of the complexes were observed when the serum was made 20 mM in EDTA before incubation with BSA.

Adult↗
PubMed1983

Quantification of human immunoglobulins by semiautomatic polyethylene glycol precipitation radioimmunoassays. Estimation of circulating immune complexes and immunoglobulin synthesized in vitro.

Simple, reliable semiautomatic radioimmunoassays have been developed for the measurement of human immunoglobulins (IgG, IgA, IgM, IgK and Ig lambda). The assays are based on the separation of free from antibody-bound radiolabelled fragments of immunoglobulin by precipitation with 13% polyethylene glycol. The precipitate is harvested and washed on glass fibre filters by means of a commercial cell harvester. Radiolabelled lambda chain from Bence Jones urine was used for lambda chain assay and Fab' gamma from pooled IgG for the kappa assay. Labelled Fab or Fc fragments of IgG, IgA and IgM were used for the class specific assays. Selected commercial antisera were used throughout. The sensitivity limits of the assays performed according to the standard procedure were about 20 ng Ig per ml. The assays have been used for the quantification of circulating immune complexes and both cellular and secreted immunoglobulin produced in cell cultures. The results demonstrate the importance of the simultaneous quantification by L chain and H chain specific assays.

Animals↗
PubMed1983

Partial characterization of physiologically generated C3 components expressing C3d but not C3c epitopes.

Techniques for the quantification of C3d are shown to estimate the sum of 4 different plasma protein components possessing C3d but not C3c epitopes. All 4 components were C3-derived polypeptides as shown by activating serum containing 125I-labelled C3, isolating the anti-C3d reactive material in 14% PEG supernatant, followed by analysis on SDS-PAGE and autoradiography. Identical results were obtained by radiolabelling 14% PEG plasma supernatants followed by analysis of the anti-C3d reactive material. The components are referred to as d1, d1', d2 and d3 based on their relative electrophoretic mobilities (alpha 1, alpha 1, alpha 2 and alpha 2 respectively) judged by crossed immunoelectrophoresis. Their apparent molecular weights by SDS-PAGE were 129K (d1), 110K (d1'), 46K (d3) and 45K (d2). The possibility that one or more of the C3d containing components represented a complex of a C3 fragment with another plasma protein was investigated. The role of these components in the scheme of the physiological breakdown of C3 and the importance of the individual C3d components as indicators of complement activation in clinical materials is discussed. It is proposed that the 45K d2 component represents a final physiological breakdown product of C3 in human serum.

Antigen-Antibody Reactions↗
PubMed1983

Estimation of immune complexes by a microplate-adapted C1q-Protein A enzyme-linked-immunosorbent-assay (C1q-PA-ELISA).

A microplate-adapted enzyme linked immunosorbent assay (ELISA) for detection of C1q-binding immune complexes (IC) and aggregated IgG (delta IgG) is described. Purified human C1q was adsorbed to the wells of flat-bottomed microtiter plates and EDTA-treated serum samples were subsequently introduced. Bound IC was measured by use of alkaline phosphatase-labelled Protein A followed by the substrate para-nitro-phenyl-phosphate. A dose response was found for both delta IgG and BSA anti-BSA complexes, while variations in the concentration of monomer IgG did not affect the optical density. Elevated levels of IC were found in the majority of sera from patients with rheumatoid arthritis and SLE. The described C1q-PA-ELISA is a simple and inexpensive method for detection of C1q-binding immune complexes. The reproducibility is acceptable and the sensitivity is higher than for most IC-methods based on C1q-binding.

Adolescent↗
PubMed1983

Reduced complement-mediated immune complex solubilizing capacity and the presence of incompletely solubilized immune complexes in SLE sera.

Reduced complement-mediated solubilization (CMS) of pre-formed immune complexes (IC) was demonstrated in sera from 11 out of 12 SLE patients. The presence of incompletely solubilized endogeneous IC in SLE sera was indicated by the following findings: (1) When IC positive SLE sera with reduced CMS capacity were mixed with normal donor sera they inhibited the CMS of the latter sera. (2) Resuspended PEG (2.75%) precipitates obtained from SLE sera inhibited the CMS of normal donor sera. (3) Non-solubilized or incompletely complement solubilized IC in SLE sera give a strong response in the PEG-CC assay for IC. The IC activity of SLE sera was clearly reduced in this assay when the endogeneous IC were solubilized prior to testing. In contrast, sera of 14 rheumatoid arthritis (RA) patients exhibited normal CMS. IC which could be further solubilized by complement were not demonstrable although all RA sera were IC positive.

Adult↗
PubMed1982

Specificities of anti-rabbit VH antibodies in mammalian and fowl antisera.

Antibodies against rabbit VH-determinants were produced by immunizing mammals and birds with rabbit IgG, IgA or VH. Most of the anti-VH produced in mammals was specific for allotype VH-determinants, but small amounts of antibody against non-allotype VH-determinants were also produced. By contrast the immunization of chickens led to the production of predominantly non-allotype VH antibody. Further analysis of the antibody specificity revealed the production of antibody against VH-determinants available in the intact immunoglobulin (H- + L-chain) as well as antibody reacting with determinants only accessible in the absence of L-chain. Antibody of the latter specificity prevailed after immunization with VH. The purified VH was not deficient in antigen determinants when compared with VH in the intact immunoglobulin (IgA). Unexpectedly, none of our chicken anti-rabbit VH antisera showed crossreactivity with VH from other mammalian species.

Animals↗
PubMed1982

Influence of mesonephros on foetal and neonatal rabbit gonads. I. Sex-steroid release by the testis in vitro.

The experiments were performed to study the influence of mesonephros on gonadal sex hormone release. Foetal and neonatal rabbit testes were cultured for 5 days, with and without their mesonephric tissue. The culture media were harvested every day and analyzed by RIA for the content of testosterone, progesterone and oestradiol. The development of the tissues were evaluated microscopically after culturing. The results show that between day 20 pc and day 1 pp the mesonephric tissue lowered the amounts of testosterone in co-cultures with testis. This effect disappears when the mesonephric derived cells develop the capacity to synthesize a meiosis inducing substance (MIS). A relationship between decrease of testosterone and secretion of MIS is discussed. It is concluded that the steroid producing cells of the testis, the Leydig cells, originate or are heavily influenced by mesonephros during early testicular organogenesis.

Animals↗
PubMed1982

Mitogen-stimulated immunoglobulin production by chronic lymphocytic leukaemic lymphocytes.

The capacity of B cells from patients with chronic lymphocytic leukaemia (CLL) to produce and secrete immunoglobulin following mitogen stimulation was investigated using sensitive radioimmunoassays for mu, gamma, alpha, kappa, and lambda immunoglobulin chains. Lymphocytes from seven of the 11 patients studied secreted immunoglobulin in response to pokeweed mitogen (PWM). IgM was always the major immunoglobulin and in five of the seven responders it was the only class detected; only one type of light chain was observed in most cases. This was in contrast to normal lymphocytes which secreted all classes of immunoglobulin (IgM was invariably the lowest) containing both types of light chain. Lipopolysaccharide induced immunoglobulin secretion in only one of four CLL cases. This was again IgM with only one type of light chain. The assays are therefore most probably measuring a response by the leukaemic cells. In most CLL cases, immunoglobulin secretion by the residual normal cells, which proliferate in response to mitogen, was not observed. This inability of the normal lymphocytes to differentiate fully into immunoglobulin secreting cells and the block in switching from IgM production to other classes in the leukaemic cells may both be attributable to a defect in the regulatory system of the immune response in CLL patients.

Aged↗
PubMed1981

Eggs: conveniently packaged antibodies. Methods for purification of yolk IgG.

Eggs from immunized chickens may provide a convenient and inexpensive source of antibodies. We describe two simple and efficient methods for purification of IgG from yolk. The antibody is rendered useful for most currently employed immunological techniques. Amounts of antibody corresponding to almost half a litre of antiserum may be recovered from a chicken in one month.

Animals↗