PubMed Health⌕ Search

Biomedical subjects

W H Stimson

Publications and source records attributed to W H Stimson.

At least 55 records · Page 3Linked to original sources
PubMed1987

Detection of ochratoxin A in porcine kidneys by a monoclonal antibody-based radioimmunoassay.

By using an indirect enzyme-linked immunosorbent assay, eight monoclonal antibodies (MAbs) were selected. Mice were immunized with ochratoxin A that was conjugated to bovine serum albumin. The hybridoma cell line designated 10G2 was grown in tissue culture and as an ascites tumor. The MAb was characterized to be specific to ochratoxin A and of the immunoglobulin G (IgG) class. Subsequently, the ascites fluid of this hybridoma was used in a competitive solid-phase IgG radioimmunoassay on protein A-Sepharose CL-4B, with [14C]ochratoxin A as tracer. Porcine kidneys were extracted with 0.5% phosphoric acid in chloroform. A two-step cleanup was achieved on a Sep-Pak C18 cartridge and a Sep-Pak silica cartridge. Radioimmunoassay with MAbs coupled to protein A-Sepharose CL-4B allowed the detection of ochratoxin A in porcine kidneys at a concentration as low as 0.2 ng/g.

Animals↗
PubMed1987

Human antibodies to ovarian cancer antigens secreted by lymphoblastoid cell lines.

Human antibodies, showing specificity for ovarian cancer, have been produced following Epstein-Barr virus transformation of lymphocytes from involved lymph nodes. Specificity was assessed initially using established ovarian cancer and other cell lines and then confirmed by histological examination, employing immunofluorescent staining of tumour tissue. The lymphocytes have been in continuous culture for more than 9 months and secrete IgG antibodies at a rate of 0.5-5 micrograms/ml/10(6) cells/5 days.

Antibodies, Neoplasm↗
PubMed1987

The human bladder carcinoma line T-24 secretes a human B-cell differentiation factor.

The effect of a B-cell differentiation factor (BCDF) found in the supernatant of the human bladder carcinoma cell line T-24 (T-24.BCDF) was assessed using the human lymphoblastoid line CESS (Muraguchi et al., 1981) and TPA-stimulated human B-CLL B cells. This T-24.BCDF was shown to cause both these cell types to secrete immunoglobulin, and therefore indicates that culture supernatants from this bladder carcinoma line contain a potent differentiation factor for human B cells.

Cell Line↗
PubMed1987

T-24.B-cell differentiation factor induces immunoglobulin secretion in human B cells without prior cell replication.

Stimulation of B lymphocytes from B-cell chronic lymphocytic leukaemia (B-CLL) with 12-0-tetradecanoylphorbol-13-acetate (TPA) has shown that these cells are capable of differentiation (Totterman, Nilsson & Sundstrom, 1980). Increases in the expression of different class II MHC antigens (Guy et al., 1983, 1986) and responsiveness to growth factors (Kabelitz et al., 1985; Suzuki, Butler & Cooper, 1985) have been studied. Supernatant from the human bladder carcinoma line T-24 contains a B-cell differentiation factor (BCDF) able to induce immunoglobulin secretion from CESS cells. We investigated the induction of proliferation and immunoglobulin secretion in human B cells by studying the effects of this factor on B-CLL cells, in both the presence and absence of TPA. We report here that this material (termed T-24.BCDF) causes immunoglobulin secretion to be initiated in these cells, and that this is not accompanied by detectable DNA synthesis. These observations were extended to normal human B cells and demonstrate that human B cells can secrete immunoglobulin in the absence of clonal expansion.

B-Lymphocytes↗
PubMed1987

A new human trophoblast antigen isolated from immune complexes derived from placental blood and membranes.

Immune complexes were prepared from human trophoblast membranes, placental blood serum, non-pregnant female serum and normal male serum by precipitation, gel filtration and affinity chromatography. The purified complexes were subjected to analysis by SDS-PAGE and one common antigenic species was identified. This antigen (mol. wt. 82.8 +/- 2.4 K) was designated the putative trophoblast antigen (TA) and shown to exhibit discrete antigenic homology with human immunoglobulin and HLA molecules.

Adult↗
PubMed1986

Human T-cell hybrids secreting lymphokines: effect of different parent cell clones of the human T-cell acute lymphoblastoid leukaemia line CCRF-CEM.

We have cloned a number of cell lines from the human T-lymphocyte acute lymphoblastoid leukaemia (ALL) line CCFR-CEM, and attempted to construct functionally active human T-lymphocyte hybrids with them. Functional hybrids were generated using only one particular clone, 3H6. The activities found in the supernatants of two of these hybrids, DB1G7 and DB2D10, are described. Supernatant from DB1G7 was found to suppress strongly the migration of normal human peripheral blood mononuclear cells, while that from DB2D10 was shown to inhibit the proliferative response of human T lymphocytes to both phytohaemagglutinin and concanavalin A. There was no cross-reactivity between the two supernatants, confirming the usefulness of the human T-lymphocyte hybrid technique in dissecting human T-lymphocyte function. The successful use of 3H6 is contrasted with the failure of another clone, 2H2, to permit the production of functional hybrids. Problems relating to the use of CCRF-CEM and its clones as parent cell lines in the production of human T-lymphocyte hybrids are discussed.

Cell Line↗
PubMed1986

A comparison of circulating immune complexes, pregnancy associated beta 1-macroglobulin and galactosyltransferase as tumour markers for ovarian cancer.

Serial blood samples have been obtained from 12 patients with ovarian cancer who were treated by surgery and, generally, chemotherapy or radiotherapy. Some achieved clinical remission, but the majority relapsed after variable time interval. Three potential tumour markers (Circulating Immune Complexes, Pregnancy Associated beta 1-Macroglobulin and Galactosyltransferase) have been studied longitudinally in serum for clinical correlation, predictive value, and biochemical 'lead time' to clinically detectable progression. None of the 3 offered any signal advantage over the others, and each showed an inconsistent relationship to observed disease status, with high levels indicating a poor outlook and the converse not true. Thus, since the 'lead time' is short, and reliability low, none of the compounds can be strongly commended as individual markers for ovarian cancer.

Adenocarcinoma↗
PubMed1986

Effects of dietary supplementation on autoimmunity in the MRL/lpr mouse: a preliminary investigation.

The effects of dietary fatty acid supplementation on various disease parameters in the spontaneously autoimmune MRL-mp-lpr/lpr mouse model of systemic lupus erythematosus before onset of disease were investigated. A fat deficient diet was supplemented with the following oils: olive oil, sunflower oil, evening primrose oil (EPO), fish oil, and a fish oil/EPO mixture. The mice receiving a diet enriched with EPO showed an increase in survival, as did those receiving the fish oil/EPO mixture. These results, taken together with those of the other parameters monitored, suggest that EPO may be of benefit in alleviating the murine form of the disease.

Animals↗
PubMed1986

A rapid enzyme immunoassay for the detection of IgM rheumatoid factor--a comparison of "sero-negative" and "sero-positive" rheumatoid patients.

The ELISA technique for measuring RF is a reliable, low cost, quick method which has adequate specificity and improved sensitivity over other methods. This last property plus its flexible potential for measuring RF in classes other than IgM should make it a particularly useful tool in assessing "sero-negative" patients, while in the long run its routine use should supersede that of the other tests.

Arthritis, Rheumatoid↗
PubMed1985

A role for amniotic epithelium in control of human parturition.

A peroxidase anti-peroxidase staining technique was used to determine the presence of pregnancy-associated prostaglandin synthetase inhibitor (PAPSI) in human amniotic epithelium from 20 pregnant women at 36-40 weeks' gestation. PAPSI was present in amniotic epithelial cells in 12 of 15 women before the onset of labour. No PAPSI was found in amniotic epithelium from 5 women in clinically established labour. These findings indicate that the amnion is a source of this endogenous prostaglandin synthetase inhibitor and suggest a local role for amniotic epithelium in initiating labour at term.

Amniotic Fluid↗
PubMed1985

Pregnancy-associated beta 1-macroglobulin: detection on the surface of ovarian cancer cell lines.

Pregnancy-associated beta 1-macroglobulin (beta 1-PAM) is a serum protein which can be detected at elevated levels in the blood of many ovarian cancer patients. The presence of the antigen was investigated on the surface of 4 human ovarian cancer lines and 32 other human and rodent cell types and lines by means of immunofluorescent staining and anti-beta 1-PAM-enzyme conjugate. The antigen was detected only on the ovarian lines but no secretion of beta 1-PAM into the culture supernatants was observed. The ovarian cancer cells appeared to display the beta 1-PAM constantly during culture, and enzymic treatment of the cells indicated that detection of the cell-bound antigen with antiserum could be, at least partially, eliminated with proteases but not glycosidases or neuraminidase. The results serve to confirm the association of beta 1-PAM with ovarian cancer.

Antigens, Surface↗
PubMed1985

The immortalization of human lymphocytes by spheroplast fusion.

A method for immortalizing animal cells based on the spheroplast fusion technique of Schaffner is being developed. Human lymphocytes have been fused with E. coli spheroplasts containing the plasmid pTSV3, which represents the entire SV40 genome cloned into the EcoRI restriction enzyme site of the plasmid pAT153. The efficiency of transformation was examined using pTSV3 and derivatives which have deletions in parts of the late gene sequences. Although there was a marked increase in the survival time of the lymphocyte cultures after fusion compared with cells which had been mitogen-stimulated but not fused, the cells did not continue to proliferate indefinitely. Attempts are now being made to extend the survival time by culturing the transformed lymphocytes in the presence of feeder cells.

Cell Division↗
PubMed1984

Androgen receptor in the human thymus.

An androgen binding species has been identified in partially purified cytosol from human thymic tissue, resolved from sex steroid binding globulin by gel chromatography. This putative 5 alpha-dihydrotestosterone receptor was characterised by high affinity (Kd 6.7 X 10(-10) M) and low capacity (9 fmol/mg of cytosol protein). High affinity binding was confirmed with methyltrienolone (R1881). Competition studies were carried out with a number of androgenic compounds and 5 alpha-19 nordihydrotestosterone was shown to possess the highest affinity for the androgen receptor.

Adult↗
PubMed1984

Human T-cell hybrids with HLA-restricted proliferative response to Epstein-Barr virus-infected B cells.

Human T-cell hybrids were constructed from an HGPRT-negative mutant of the acute lymphoblastoid leukaemia cell-line CEM and an uncloned population of T cells from donor SW (SW-T; partner cell) known to have a strong specificity for the autologous Epstein-Barr virus (EBV)-transformed B cell, SWEBV. The resulting hybrids, 1A9, 1D12 and 2C8, were shown not to be cytotoxic to SWEBV, nor did they have natural killer-like (NK) activity. However, when presented with the target SWEBV in a mixed lymphocyte reaction (MLR), all of the hybrids rapidly increased their rate of proliferation by up to a factor of seven. Hybrid 1D12 also produced interleukin-2-like material (IL2) under these conditions. The hybrids did not react with the autologous PHA-blasts (SWPHA), nor with various unrelated targets. When tested against a bank of EBV-transformed B-cell targets, it was observed that the human T-cell hybrids 1A9 and 2C8 responded only to those targets bearing the antigen HLA Bw35. This response could be blocked by treating the target with the monoclonal antibody W6/32, specific for a shared determinant of the HLA-A, -B and -C antigens. Similarly, the human T-cell hybrid 1D12 reacted only against those targets bearing the antigen HLA DrW2, and this activity could be blocked by the monoclonal antibody DA6.231, specific for a common region of the HLA-DR and SB antigens. Thus, human T-cell hybrids can be produced which exhibit HLA-restricted responses to antigenic stimulation.

Antigens, Surface↗
PubMed1983

Pregnancy-associated alpha 2-macroglobulin - a new serum protein elevated in normal human pregnancy.

A new pregnancy-associated serum protein has been isolated and characterised - pregnancy-associated alpha 2-macroglobulin (alpha 2-PAM). The native macromolecule has a molecular weight of 2.1 x 10(6) and a sedimentation coefficient of 19.6 S. This is comprised of 28 000 dalton subunits and contains 11% carbohydrate. alpha 2-PAM was found in normal male and female blood at a concentration of 25 micrograms/ml but no significant variation in this value was apparent in individuals followed over a 12 week period. The serum level can rise up to 16-fold during the first trimester of pregnancy and returns to normal levels within 8 weeks after delivery. Concentrations in contraceptive-steroid treated women, cord blood and breast milk were in the same range as normal adult sera while alpha 2-PAM could readily be detected in amniotic fluid at 8 micrograms/ml.

Adolescent↗
PubMed1983

Generation of human T-cell hybrids with the characteristics of human peripheral blood T-lymphocytes.

Using a selection system based on the two irreversible biochemical inhibitors, actinomycin-D and emetine hydrochloride, we have constructed human T-lymphocyte hybrids between the human T-cell line, Molt-4F, and mitogen-activated human lymphocytes. The cells were identified as true hybrids by their karyotype, differences in supernatant activities, responses to mitogen and membrane characteristics. These hybrid cells are stable in culture and express functions found in mature human T-lymphocytes.

Adult↗