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Biomedical subjects

I E Addison

Publications and source records attributed to I E Addison.

35 records · Page 2Linked to original sources
PubMed1981

Buffy coat and cell separator granulocyte concentrates. Comparison of cell content and in vitro granulocyte function.

Buffy coat granulocyte concentrates were prepared manually from single fresh whole blood donations after centrifugation. The erythrocyte, granulocyte and platelet numbers in these concentrates were compared to cell numbers in concentrates obtained by mechanical leukapheresis using intermittent flow centrifugation. Buffy coats contained approximately half the number of granulocytes and three times the number of erythrocytes per unit volume than cell separator concentrates. There was no difference in platelet numbers. Thus to give a therapeutic dose of granulocytes equivalent to that obtained by cell separation, 2-3 times greater volume of buffy coat concentrates would be required. In vitro granulocyte function, as measured by migration, phagocytosis, and Candida killing was also compared in buffy coat and cell separator concentrates. The only difference found was reduced Candida killing in the buffy coat granulocytes. The possible clinical use of buffy coat concentrates, as a source of granulocytes, is discussed.

Blood Cell Count↗
PubMed1981

Use of whole blood in the measurement of neutrophil migration.

A whole-blood method was used for measuring neutrophil migration in micropore membrane. The method is reproducible (coefficient of variation (CV) 10.3% and 9.8% in two normal individuals tested repeatedly) and can be performed on an 0.25 ml lithium heparin blood sample. Migration is independent of leucocyte and erythrocyte counts and is comparable with that obtained for separated cells. As in separated cell techniques, cytochalasin and casein respectively inhibit and stimulate neutrophil migration. The technique is of value when testing large numbers of samples and when only small volumes of blood can be obtained, for example, in neonates.

Anticoagulants↗
PubMed1981

Defective neutrophil function in low-birth-weight, premature infants.

A whole-blood technique was used to measure simultaneously neutrophil migration, uptake, and killing of candida in 27 premature infants of low birth weight (less than 1500 g). Neutrophil migration was consistently reduced, especially in the first two weeks of life. Phagocytosis was also reduced, particularly in the first week of life and in sick patients. Killing was usually normal, except in sick patients. The three functions were not altered when the test was performed in normal adult, rather than autologous, plasma, and the reduced migration and uptake are therefore the result of an intrinsic defect of the cell. The results clarify the previous controversy concerning neutrophil function in premature infants and provide an explanation for their increased susceptibility to infection.

Adult↗
PubMed1981

Thymus-dependent and thymus-independent antibody responses: contrasting patterns of immunosuppression.

The effects of mitoclomine, an anti-tumour agent, and of cortisone acetate on the antibody response of mice to thymus-dependent and thymus-independent antigens were compared. Both agents yielded patterns of immunosuppression which differed from that seen after X-rays, an agent which is likely to be active equally against T and B cells. Mitoclomine, at low doses, depressed thymus-independent responses the most; this effect can be explained if the drug is more active against B than T cells. Cortisone acetate at low doses, while depressing thymus-dependent responses, increased thymus-independent responses; this can be explained if the drug is more active against T than B cells. Thus three different patterns of immunosuppression (for X-rays, mitoclomine and cortisone acetate) can be interpreted in terms of effects simply on T or B cells.

1-Naphthylamine↗
PubMed1979

Subcutaneous Corynebacterium parvum in bladder cancer: a controlled study of its immunological effects.

Fourteen out of 26 patients with invasive bladder cancer were randomly assigned to receive weekly subcutaneous injections of Corynebacterium parvum (CP) in addition to standard treatment. Peripheral blood T lymphocyte percentage, K cell activity, mitogen responsiveness, and monocyte and polymorph leucotaxis were measured at intervals over a period of 1 to 2 years. The only consistent difference between the CP-treatment patients and the controls was a slightly higher level of K cell activity in the former, who, however, fared rather worse than the controls in terms of survival.

Cell Survival↗
PubMed1976

A raft technique for chemotaxis: a versatile method suitable for clinical studies.

We describe a raft technique for the study of chemotaxis which possesses a number of advantages over the use of chambers. Membranes are laid on pads soaked in chemotactic agent and cells are contained in plastic cups, which are inverted on to the membrane. This method gives results which are similar to those obtained in conventional vessels. It would seem well suited to comparative measurements of chemotaxis in clinical series, for it avoids the use of special chambers, minimises the number of membranes and their handling and more than one cell suspension can be placed on a membrane. In addition, the method is experimentally versatile: simple manipulations allow work with cells adherent to other surfaces, studies of the effect of substituting a new agent or of reversing the gradient during an experiment, migration against gravity, and of the effect of non-adherent cells on migrating cells.

Animals↗
PubMed1976

Intercellular immunological controls and modulation of cyclic AMP levels. Some doubts.

We have re-examined two sets of observations put forward to support the hypothesis that rises in cAMP levels induced by vasoactive amines and prostaglandins are involved in the intercellular control of immunological and inflammatory processes. (1) This hypothesis is said to be supported by the fact that cholera toxin, which raises cAMP levels in lymphoid tissue in vivo, is immunosuppressive. However, we found that cholera toxin inhibited antibody production only if given in doses causing gross destruction of lymphoid tissue. This sort of evidence, therefore, cannot be used to support a hypothesis about homoeostasis under physiological conditions. (2) The hypothesis is also said to be supported by the claim that vasoactive amines, prostaglandins, cholera toxin and methyl xanthines, which raise cAMP levels in cells in vitro, also inhibit the formation of haemolytic plaques by spleen cells from mice immunized with sheep red cells. However, we were unable to confirm this claim, except when the experimental conditions were such that cells were killed or other artefacts operated.

Animals↗
PubMed1975

Increased antibody production following depression of hepatic phagocytosis.

The influence of Kupffer cell blockade on the humoral immune response to suboptimal doses of intravenous sheep red blood cells has been measured in mice. Hepatic phagocytosis was suppressed using dextran sulphate. Direct (IgM) and indirect (IgG) plaque-forming cells were measured in spleens from treated and untreated mice at varying times after the antigen. The results show that after Kupffer cell blockade both IgM and IgG responses correspond to the responses seen after a 10-fold greater dose of cells in control animals. The implications of this are discussed.

Animals↗
PubMed1971

The effect of cysteine on the immunosuppressive activity of busulphan, cyclophosphamide and nitrogen mustard.

The effect of cysteine on the immunosuppressive activity of three alkylating agents was tested. Cysteine strongly inhibited the ability of cyclophosphamide and nitrogen mustard to depress the direct plaque-forming cell response of mice to sheep red cells. In contrast, the activity of busulphan was usually potentiated by administration of cysteine. This throws doubt on the hypothesis that busulphan exerts its cytotoxic effects by alkylating thiol groups.

Alkylation↗