PubMed Health⌕ Search

Biomedical subjects

R D Jurd

Publications and source records attributed to R D Jurd.

9 recordsLinked to original sources
PubMed1978

Effect of temperature on transplantation immunity in Ambystoma mexicanum.

Juvenile and mature neotenous Ambystoma mexicanum received allogeneic and xenogeneic skin transplants. Rejection times for 1st-set, and 3rd-set grafts were noted at 21 degrees C, and for axolotls placed in a cold-room at 7 degrees C 7 h post-grafting, 1 week post-grafting and 2 weeks post-grafting respectively. In all cases graft-rejection was chronic; 2nd and 3rd-set grafts were rejected progressively more rapidly than 1st-set grafts. An important temperature-sensitive event occurs during the 1st week post-grafting.

Aging↗
PubMed1978

A natural heterohaemagglutinin in Xenopus laevis serum.

In most adult Xenopus laevis the serum contains a 'natural' factor capable of lysing the erythrocytes from a wide variety of amniote species. The factor has no effect on the erythrocytes of another amphibian, Ambystoma mexicanum, nor will serum from one animal lyse red cells from another Xenopus individual. No lysing factor was present in the serum of larval (tadpole) Xenopus. Heating of Xenopus serum to 56 degrees for 30 min, absorption of the serum with zymosan or inulin, or removal of calcium and magnesium ions results in loss of lytic activity, although haemagglutinating activity remains, suggesting that the factor can fix complement. The factor elutes from a gel chromatography column in the 19S peak, and is inactivated by thiol reduction and subsequent alkylation. These findings, coupled with immunoabsorption studies suggest that the haemagglutinin is an immunoglobulin of the IgM class. The significance of this suggestion is discussed in the light of previous reports of 'natural' heterohaemagglutinins in other species.

Agglutinins↗
PubMed1977

Antibody-dependent cellular cytotoxicity in poikilotherms.

51Cr-chromate labelled chicken red blood cells, treated with rabbit (anti-chicken red blood cell) serum, are lysed in vitro, in the absence of complement, by spleen cells from Xenopus laevis, Ambystoma mexicanum or Lacerta viridis. Optimal conditions for lysis by Xenopus spleen cells were determined. The phenomenon seems homologous with antibody-dependent cellular cytotoxicity (ADCC) mediated by mammalian or avian K cells. The phylogenetic significance of the finding is discussed.

Ambystoma↗
PubMed1975

Surface immunoglobulin of guinea-pig leukaemic lymphocytes.

The surface immunoglobulin of the transplantable L2C leukaemia of strain 2 guinea-pigs has been investigated. The immunoglobulin is seen to be synthesized when the cells are maintained in culture, indicating its intrinsic origin. Immunolabelling of the cell surface and immunochemical study of the Fab released by limited surface proteolysis indicate the presence of immunoglobulin of class IgM. IgG and free light chains were not detected, and there is unlikely to be an appreciable amount of immunoglobulin of any other class. The amount of immunoglobulin present, in terms of 4-chain monomers, is approximately 100,000 molecules per cell. Its half-life, calculated from the rate of reappearance in vitro of surface Fab after proteolytic clearing, is approximately 5 hours. Immunoglobulin secreted into the environment appears to arise predominantly or entirely from the cell surface: there is no evidence of an appreciable export of immunoglobulin which does not have a surface phase. Papain at 0.06 mg/ml rapidly removes the surface Fab. Residual Fcmu can then be detected by immunofluorescence, suggesting that papain cleaves surface IgM at a hinge region with the molecule in situ on the membrane. The released Fab is only moderately susceptible to degradation by papain at the enzyme: substrate ratio prevailing. It has been possible to isolate it from the papain digest by immuno-adsorption, with a notional yield of 75 mug per 10-10 cells, and then to prepare antisera against it.

Animals↗