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Biomedical subjects

K James

Publications and source records attributed to K James.

At least 217 records · Page 12Linked to original sources
PubMed1984

A mouse monoclonal antibody with anti-A,(B) specificity which agglutinates Ax cells.

A hybridoma (ES-15) was obtained by fusing the NS-1 cell line with spleen cells from a mouse immunised with soluble blood group A2 substance. The cloned hybridoma culture supernatant was shown to contain an IgM class antibody which strongly agglutinates group A cells and weakly agglutinates group B cells. The serological specificity of this antibody is described as anti-A,(B) in this report. The abilities of unconcentrated monoclonal anti-A,(B), a commercial human polyclonal anti-A,B (group O serum) and a commercial monoclonal anti-A reagent to detect 15 examples of Ax cells were compared by both slide and tube techniques. Using a slide technique monoclonal anti-A,(B) agglutinated 14 examples of Ax cells, human anti-A,B 2 examples, while monoclonal anti-A failed to detect any of the Ax cells tested. Similar differences in the reactivity of the three antibodies were observed using a tube technique. Data are also presented which show that a 1:1 (v/v) mixture of monoclonal anti-A,(B) with a monoclonal anti-B reagent is an effective replacement for human anti-A,B in ABO grouping procedures.

ABO Blood-Group System↗
PubMed1984

Lymphocyte subsets in renal carcinoma--a sequential study using monoclonal antibodies.

Using monoclonal antibodies in conjunction with flow cytometry, circulating lymphocyte subsets with distinct functions in the regulation of the immune response were enumerated in 32 patients with proven renal carcinoma. Analyses were performed at presentation and sequentially during the clinical course of the patients. Untreated patients with advanced disease had a deficit of T cells with the "helper/inducer" phenotype (Leu-3a+) and this resulted in abnormal T "helper/suppressor" (Leu-3a+/Leu-2a+) ratios. Following nephrectomy, performed in 26 patients, there was a significant increase in the number of T cells with the "helper/inducer" phenotype and a significant increase in T "H/S" ratios. Subsequent follow-up at a minimum of 2 months after nephrectomy showed that the increase in T cells with the "helper/inducer" phenotype was maintained (with the exception of 6 patients with disease progression) and was then accompanied by a significant increase of the T cell subset with the "suppressor/cytotoxic" phenotype (Leu-2a+). Pre-operative renal arterial embolisation resulted in an early transient lymphopenia. The response to embolisation combined with nephrectomy was little different when compared with nephrectomy alone. These observations represent a novel view of the immunosuppressive effects of renal carcinoma and their relation to anaemia and disease progression are discussed.

Adult↗
PubMed1984

Intra-epithelial lymphocytes in the normal epididymis. A mechanism for tolerance to sperm auto-antigens?

Using a monoclonal immunoperoxidase technique on frozen tissue sections of normal testis and epididymis, a distinctive distribution of lymphocytes has been identified. Almost all of the intra-epithelial lymphocytes were T cells and the majority of these belonged to the T8+ ("suppressor/cytotoxic") subset. The distribution contrasted with the predominance of the T4+ ("helper/inducer") subset in the interstitial tissues and in normal peripheral blood. The predominance of the "suppressor/cytotoxic" subset within the epithelium of the epididymis may exist in order to prevent the development of the immune response to auto-antigens on spermatozoa.

Adult↗
PubMed1984

Platelet and coagulation factors in proliferative diabetic retinopathy.

Plasma beta-thromboglobulin, platelet factor 4, fibrinogen, fibrinopeptide A, antithrombin III, factor VIII related antigen, alpha 2-macroglobulin, platelet count, and total glycosylated haemoglobin were measured in three well matched groups of subjects: non-diabetic controls, diabetics without retinopathy, and diabetics with proliferative retinopathy. beta-thromboglobulin and platelet factor 4 concentrations were significantly higher in the diabetics with retinopathy than in the controls and platelet factor 4 was also increased in the diabetics without retinopathy compared with controls. Fibrinogen concentration was raised in diabetics without retinopathy compared with controls, diabetics with retinopathy compared with controls, and diabetics with retinopathy compared with those without. Fibrinopeptide A concentration did not differ significantly between groups. Antithrombin III levels were increased in diabetics with retinopathy compared with controls, and in diabetics with retinopathy compared with those without. Factor VIII related antigen values were higher in both the diabetic groups when compared with the controls. Fibrinopeptide A concentration correlated with both beta-thromboglobulin and platelet factor 4 in each of the three groups. Haemostatic abnormalities in diabetes have been shown, although a hypercoagulable state has not been confirmed. These changes in platelet and coagulation function may be secondary to the development of microvascular disease and their role in the pathogenesis of retinopathy remains uncertain.

Adult↗
PubMed1984

Genetic linkage studies of transferrin, pseudocholinesterase, and chromosome 1 loci.

Genetic linkage analysis of a pedigree with four different alleles for pseudocholinesterase (CHE1) gives a positive lod score of 0.37 at theta = 0.16 for linkage with transferrin (TF), a finding which supports previous reports of linkage between CHE1 and TF. Evaluation of linkage relations of CHE1 and TF using unreported families from our data bank fails to establish linkage with chromosome 1 loci (6-PGD, Rh, PGM1, AMY2 and FY). These results are consistent with recent studies which suggest that TF is on human chromosome 3.

Alleles↗
PubMed1984

A monoclonal antibody-based immunoradiometric assay for h-LH.

An immunoradiometric assay (IRMA) for h-LH based upon an 125I-labelled mouse monoclonal antibody (MAb) to h-LH with an effective equilibrium constant of 5.8 X 10(9) l/mol is described. A total incubation time of 3 h at room temperature was required, separation by means of the sucrose layering procedure took a further 1 h and counting times were 1 min/tube. Using the first IRP for h-LH (prep. 68/40) as standard, the detection limit was 0.1 U/l serum and the within-assay CV for duplicate determinations was less than 10% over the range 1-280 U/l and less than 3% at 10-100 U/l. The epitope, with which the MAb reacted, shared structures, on the alpha- and beta-subunits of LH since the assay responded to the intact hormone, but not to either of the subunits. Specificity was greater than 100 000:1 for h-LH vs. h-FSH and greater than 10 000:1 for h-LH vs. h-TSH. h-CG and h-LH were approximately equipotent. The results on 604 unselected samples were generally very similar to those found by RIA except at levels below 2 U/l for which the IRMA regularly gave lower results suggesting relative freedom from non-specific serum effects. The new assay, based upon potentially limitless supplies of a very stable reagent offers advantages of speed, sensitivity, range, and precision over conventional RIA. The specificity appears to be excellent. Although there are marginally more steps the total staff involvement is less than with conventional methods employing centrifugation.

Animals↗
PubMed1984

The preparation, characterization and application of monoclonal antibodies to human prostatic acid phosphatase (PAP).

Hybridoma cells secreting anti-PAP were produced by fusion of NS-1 myeloma cells with spleen cells from immunized Balb/c mice. Three of 32 hybrids secreted antibodies. Dilution cloning of the two hybrids producing the highest antibody titres showed that each antibody was monoclonal. One clone from each hybrid (clones ES2 and ES8) was selected for further study. The specificity of the antibodies appeared satisfactory, no inhibition of 125I-PAP binding to antibody being seen with extracts of bone, intestine, kidney, leucocytes, liver or lung. The association constants of the antibodies from ES2 and ES8 were 1.7 X 10(8) and 1.7 X 10(9) l/mol respectively, both were of the IgG1 class. For the immunoradiometric (IRMA) assay of serum PAP 125I-labelled monoclonal antibody was incubated with serum and the PAP-labelled antibody complex was separated by addition of solid-coupled polyclonal anti-PAP. The wide working range of the response curve (0.3-400 micrograms/l) and the rapid analysis time (4 h) offer practical advantages over RIA procedures. Clinical evaluation of the assay is in progress. ES8 antibody also appears to have good specificity for immunocytochemical applications. Localisation of micrometastases in bone in prostatic carcinoma was readily achieved.

Acid Phosphatase↗
PubMed1984

Optimization of assay conditions in monoclonal-based immunoradiometric assay.

The production of relatively large amounts of pure monoclonal antibodies (MAb) has facilitated the development of MAb-based immunometric assays for a variety of clinically important analytes. 'Two-site' heterogeneous assays are now available which incorporate a labelled MAb and a second, different MAb coupled to a solid support. These assays possess certain advantages over the corresponding immunoassays including speed, precision, working range and specificity. They are largely dependent on two specific molecular interactions (labelled MAb-antigen; antigen--solid support MAb) and thus one might expect them to be particularly sensitive to assay conditions. With reference to two MAb--based two-site immunoradiometric assays (for human growth hormone and prolactin) which are being developed in this laboratory we wish to report the effect of various conditions including pH, ionic strength, buffer species etc. on assay response in order to emphasize the need for careful optimisation of monoclonal antibody based assays.

Animals↗
PubMed1984

Evaluation of monoclonal antibodies to blood group A.

Balb/c mice were immunized with human blood-group A2 active cyst fluid glycoprotein. Fusion of spleen cells with NS-1 myeloma cell line produced a total of 11 blood group antibody secreting hybridomas of which seven were apparently specific for blood-group A and were subjected to further evaluation. Of these 2 were IgM class and 5 IgG class. Two anti-A supernatants showed a significant decrease in avidity time against A2B cells when ionic strength was increased to 0.25. Tube titres of all anti-A supernatants were unaffected by ionic strength. pH had no effect on the avidity time or tube titre of any of the antibodies tested. The supernatant from one hybrid (ES-9) was selected for further evaluation as a blood grouping reagent. This supernatant had a tube titre of 1:128 and was used without concentration for comparison of its serological reactivity with two examples of commercial monoclonal anti-A and one example of human anti-A. Monoclonal anti-A (ES-9) was found to be a potentially useful red cell grouping reagent.

ABO Blood-Group System↗
PubMed1984

A monoclonal antibody to human blood group B. Performance, evaluation and optimisation.

A monoclonal anti-B antibody (ES-4) was obtained by fusing spleen cells from a mouse immunized with soluble human blood group B substance with mouse myeloma cell line NS-1. The antibody was shown to agglutinate optimally group B cells at pH 7.2 and 0.15 ionic strength. Increasing the ionic strength to 0.24 gave optimal reactivity over a wider pH range. Culture supernatant containing anti-B (ES-4), after pH and ionic strength adjustment could be used in unconcentrated form as a red cell typing reagent. Anti-B (ES-4) agglutinated five examples of cells of the Bweak (Bw) phenotype and one example of acquired B phenotype. In contrast three of the Bw cells and the acquired B phenotype were not agglutinated by a commercial monoclonal anti-B by a tube technique. The data suggested that the equilibrium constant of the monoclonal anti-B (ES-4) was higher than that of the commercial reagent.

ABO Blood-Group System↗
PubMed1984

Experiences in the production of human monoclonal antibodies to tetanus toxoid.

The production of human monoclonal antibodies has been attempted using tetanus toxoid as a model antigen since a human antibody of this specificity could have clinical applications. Both mouse and human myeloma cell lines were used as fusion partners and the effects of in vivo and in vitro antigen boosting were also investigated. A cell line, ES12, which secreted specific tetanus toxoid antibody arose following fusion of lymphocytes from a donor who had been boosted three months earlier. Antibody was secreted by this cell line at a high titre (2.5 I.U/ml); it was of IgG isotype and it protected mice against challenge with tetanus toxin. This is, therefore, a first step in producing a therapeutically useful monoclonal antibody.

Animals↗
PubMed1984

Specific antibody response after in vivo antigenic stimulation in systemic lupus erythematosus.

Several in vitro studies have demonstrated a polyclonal B cell response to antigenic stimulation in patients with systemic lupus erythematosus (SLE). To determine if this polyclonal response occurs in vivo, 18 patients with SLE were antigenically stimulated with the pneumococcal vaccine Pneumovax . Mean antibody response to immunization was the same in SLE and normal control subjects. Although elevated antibody levels to several viruses were present in SLE subjects preimmunization, these levels did not change postimmunization. Total immunoglobulin levels, immune complex levels, and antiblood group B antibody levels did not change in SLE patients after immunization. Antiblood group A titers rose in both SLE patients and normals due to a media contaminant in the Pneumovax . Thus, SLE patients appear to have a specific antibody response to antigenic stimulation with pneumococcal polysaccharide. Polyclonal activation as seen in vitro in SLE may be more restricted in vivo.

Adult↗
PubMed1983

Circadian variation of lymphocyte subpopulations: a study with monoclonal antibodies.

Use of monoclonal antibodies to identify subpopulations of circulating lymphocytes in healthy adults showed pronounced circadian variations in total T cells, the two major T cell subsets, and HLA-DR+ lymphocytes. When the results for the T cell subsets were expressed as a ratio (helper:suppressor) no significant rhythmic variation was observed. Lymphocytes bearing a surface antigen identified by the HNK-1 antibody (a population containing the natural killer and antibody dependent killer activity) did not show significant rhythmic variation. There was an inverse relation between plasma cortisol concentration and numbers of T and B cells. These observations have therapeutic implications and should be considered in the course of immunological monitoring.

Adult↗
PubMed1983

Antibodies to tumour eluates react preferentially with non-lymphoid tumours.

Rabbit antisera raised against eluates from a murine fibrosarcoma were characterised using a 125I-protein A assay and a wide variety of target cells. The sera bound preferentially to rodent tumours of non-lymphoid origin, whereas monkey and human cells did not react. Murine lymphoid cells and macrophages (normal or transformed) and normal liver and kidney cells all bound low amounts of the antibody, while embryonic cells were intermediate in reactivity. Target cell treatments indicated that the surface antigens being detected were sensitive to proteolysis and calcium depletion. In addition actively growing cells bound more antibody than resting cells. Double binding assays with sera specific for plasma membrane components suggested the eluate antigens may play a structural role. Immunofluorescent studies demonstrated that surface antigens detected by the antisera capped and were lost and this was followed by synthesis and surface re-expression. Sera such as these, which can distinguish between normal and malignant cells in the rodent, have obvious applications in many aspects of tumour-related investigations.

Animals↗
PubMed1983

Concanavalin A receptors and capping in control and activated macrophages.

Macrophages activated in vivo with Corynebacterium parvum and asbestos showed an increased sub-population of cells which capped spontaneously on incubation with fluoresceinated Concanavalin A compared to saline-induced control macrophages. This capping was unaffected by colchicine but was inhibited by cytochalasin B. The spontaneous capping of activated macrophages did not appear to be directly related to the total number of Concanavalin A receptors as measured by specific 125I-labelled Concanavalin A binding to activated and control macrophages. Capping also did not appear to be related to the position of Concanavalin A receptors as judged by trypsin accessibility of bound 125I-labelled Concanavalin A.

Animals↗
PubMed1983

A solid phase C1q enzyme assay for circulating immune complexes adapted for routine clinical laboratory testing.

An assay for circulating immune complexes (CIC) that is adaptable to a routine clinical laboratory is described. This solid phase C1q (SP C1q) enzyme immunoassay (EIA) uses commercially available reagents and is reproducible with CV% of less than 20% in the abnormal range. We also demonstrate the specificity of the assay for detecting clinically relevant dsDNA-anti-DNA immune complexes.

Antibodies, Anti-Idiotypic↗