Biomedical subjects
K L Stevenson
Publications and source records attributed to K L Stevenson.
Ammonia and carnitine concentrations in children treated with sodium valproate compared with other anticonvulsant drugs.
Plasma ammonia was measured in 59 children requiring anticonvulsant drugs: 37 children (group 1) on sodium valproate alone or in combination with other drugs and 22 children (group 2) on drugs other than sodium valproate. Plasma ammonia was higher in group 1 children. Total and free carnitine was measured in plasma and erythrocytes of all children and in the urine of 16 children from group 1 and eight from group 2. Plasma and erythrocyte free carnitine was significantly lower in the children on sodium valproate, along with a significant increase in the ratio of acyl (bound) carnitine to free carnitine. No significant correlation was found between plasma ammonia and carnitine concentrations for either group of children. Plasma and erythrocyte concentrations were not related. Urinary free carnitine was reduced in children treated with valproate, with a significant increase in the ratio of bound to free carnitine. Carnitine supplementation is discussed.
Production of a monoclonal allo-antibody to murine natural cytotoxic cells.
A mouse IgG1 monoclonal antibody (1C4), which recognizes a cell surface molecule on murine natural cytotoxic (NC) cells was produced. By flow cytometry, 1C4 preferentially reacted with less than 5% of fresh CBA spleen cells and 20-50% of CBA-interleukin-3 (IL-3) cells, an in vitro derived NC-like cell line. In vitro treatment of spleen cells from a number of inbred mouse strains either with 1C4 alone or 1C4 coupled to dynabeads markedly decreased or abolished NC activity of the cells against 51Cr-labelled WEH1-164 targets. Splenic NC activity of these same mouse strains was also reduced or abolished by in vivo administration of 1C4. The effect was evident within 2 h of treatment and persisted for at least 1 week. In contrast 1C4 had little or no effect on splenic NK activity against 51Cr-labelled YAC-1 targets over the same range of experiments in vitro and in vivo. Results of strain surveys for both in vitro and in vivo reduction of splenic NC activity by 1C4 treatment showed that CBA, C57BL/6, BALB/c and NZB mice were positive and CE and DBA/2 mice were negative, indicating that 1C4 recognizes an allo-antigen on mouse NC cells. This allo-antibody has been designated NC-1.1, and thus 1C4 is an anti-NC-1.1 monoclonal antibody.
Expression of natural killer (NK) cell-specific alloantigens on a mouse NK-like cell line.
As part of the strategy for screening for natural killer (NK) cell-specific monoclonal antibodies (MoAb) we have raised a number of murine NK-like cell lines in media containing interleukin-2 (IL-2). The detection of specific NK cell alloantigens on a C57BL/6 cell line in long-term culture in IL-2 is the subject of this paper. The C57BL/6 cell line has the morphology of large granular lymphocytes (LGL) and exhibits strong cytolytic activity against the archetype NK cell target, YAC-1. Absorption of three anti-NK antiserum, NZB anti-BALB/c (anti-NK-2.1), BALB/c anti-DBA/2 (anti-NK-3.1) and CE anti-CBA (anti-NK-4.1), with the C57BL/6 cell line removed the anti-NK activity from these antisera. Flow cytometric studies of the C57BL/6 cell line demonstrated significant binding of the anti-NK-1.1 MoAb produced by hybridoma PK136. Our results suggest that the C57BL/6 NK-like cell line exhibits some of the properties of naive NK cells and expresses all the known NK cell-specific alloantigens, NK-1.1, NK-2.1, NK-3.1 and NK-4.1 and therefore is potentially useful in selecting NK specific hybridomas and in studying the biology of NK cells.
Analysis of antibodies against mouse spermatozoa using an enzyme-linked immunosorbent assay (ELISA).
Conventional techniques used for the analysis of antisperm antibodies are not suited to the mouse model because of their requirements for relatively large amounts of serum and their inability to handle large numbers of samples. This has inhibited use of the mouse as an experimental model in areas involving antisperm immunity. As the ELISA technique has been successfully applied to analysis of antisperm antibody in human sera, we investigated its use as an assay for screening antisperm antibody in mouse serum. This report describes a simplified version of the ELISA technique that we have found to be successful for this purpose. The assay described can assess levels and classes of antisperm antibody in mouse serum and can also be used as a screening assay for monoclonal antibodies to mouse sperm. It should facilitate use of the mouse in experimental work in areas involving assessment of immunity to sperm.