Functional study of lipids of PNH red cell membranes: susceptibility of liposomes to reactive lysis

Lipids extracted with chloroform-methanol from red blood cell membranes of 7 PNH and 13 control subjects were used for the preparation of liposomes, which were then examined with the reactive lysis test. PNH liposomes lysed to a higher extent than control liposomes as indicated by the higher dilution of the limiting complement reagent that was necessary to lyse 50% of the PNH liposomes. A similar finding was also observed with liposomes made of lipids from AET-treated red cells. The enhanced reactive lysis can be attributed to the polar lipid fraction, as indicated by the increased lysis of hybrid liposomes prepared from this polar lipids extracted from PNH erythrocyte membrane and lipids extracted from normal erythrocyte membrane. The increased susceptibility to reactive lysis does not seem to be specific of PNH liposomes, since it was also observed with liposomes prepared from lipids of red cells from beta-thalassemia major and autoimmune hemolytic disease.     

Medical action for global security (MEDACT): Founding statement

Two principles should underpin the provision of primary health care to refugees: (a) that refugees should have the same access to quality primary care services as the local population, and (b) any specialist service should have the goal of full integration of the refugee into normal general practice. The various ways in which medical care can be provided to refugees and the knowledge, skills and attitudes important to such provision are described. One way in which such a service was provided in east Kent is reported. The term ‘refugee’ encompasses newly arrived refugees who are awaiting a decision from the Home Office, as well as those who have been given permission to stay, either as recognized Refugees under the provisions of the 1951 United Nations Convention, or with Exceptional or Indefinite Leave to Remain.     

Combination protocols of cytokine therapy with interleukin-3 and granulocyte-macrophage colony-stimulating factor in a primate model of radiation-induced marrow aplasia

Single cytokine therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) has been shown to be effective in decreasing the respective periods of neutropenia and thrombocytopenia following radiation- or drug-induced marrow aplasia. The combined administration of IL-3 and GM-CSF in normal primates suggested that a sequential protocol of IL-3 followed by GM-CSF would be more effective than that of GM-CSF alone in producing neutrophils (PMN). We investigated the therapeutic efficacy of two combination protocols, the sequential and coadministration of recombinant human IL- 3 and GM-CSF relative to respective single cytokine therapy, and delayed GM-CSF administration in sublethally irradiated rhesus monkeys. Monkeys irradiated with 450 cGy (mixed fission neutron:gamma radiation) received either IL-3, GM-CSF, human serum albumin (HSA), or IL-3 coadministered with GM-CSF for days 1 through 21 consecutively postexposure, or IL-3 or HSA for days 1 through 7 followed by GM-CSF for days 7 through 21. All cytokines and HSA were injected subcutaneously at a total dose of 25 micrograms/kg/d, divided twice daily. Complete blood counts (CBC) and platelet (PLT) counts were monitored over 60 days postirradiation. The respiratory burst activity of the PMN was assessed flow cytometrically, by measuring hydrogen peroxide (H2O2) production. Coadministration of IL-3 and GM-CSF reduced the average 16-day period of neutropenia and antibiotic support in the control animals to 6 days (P = .006). Similarly, the average 10-day period of severe thrombocytopenia, which necessitated PLT transfusion in the control animals, was reduced to 3 days when IL-3 and GM-CSF were coadministered (P = .004). The sequential administration of IL-3 followed by GM-CSF had no greater effect on PMN production than GM-CSF alone and was less effective than IL-3 alone in reducing thrombocytopenia. PMN function was enhanced in all cytokine-treated animals.