BACKGROUND: Blood transfusions are associated with numerous clinical phenomena attributable to reduced posttransfusion immunocompetency. The exact mechanism by which blood transfusions induce a state of reduced immune responsiveness remains unclear. STUDY DESIGN AND METHODS: The effect of a large-volume blood transfusion on the frequency and responsiveness of immune cells in lymphoid compartments was examined in normovolemic rats. The effects of syngeneic and allogeneic blood transfusions were compared. RESULTS: The results in normovolemic rats were compared to those in nontransfused and saline-infused animals. In the normovolemic rats, there was a significant decrease in cells of erythroid lineage in bone marrow, with a slight increase in the percentage of cells in the bone marrow myeloid and lymphoid lineages; a significant increase in the percentage of the OX7+ Thy1+ cell population in bone marrow cells (stem cells are contained in this population) and blood cells; a decrease in the bone marrow OX6+ cell population (HLA class II-positive cells); a decrease in the responsiveness of blood, spleen, lymph node, and bone marrow cell populations to mitogens; and a downregulating effect of both syngeneic and allogeneic blood transfusions on hematopoiesis and cell responsiveness. CONCLUSION: Massive whole blood transfusion, either syngeneic or allogeneic, constitutes a strong downregulating signal for hematopoiesis, affecting the erythroid, myeloid, and lymphoid cell lineages. It leads also to an attenuation of the responsiveness of hematopoietic tissues to mitogenic stimuli.

Animals↗

PubMedDate not supplied

Influence of whole-body hyperthermia on natural cytotoxicity of liver blood-borne sinusoidal cells.

Rat liver sinusoidal cytotoxic cells were examined after exposure to in vivo and in vitro hyperthermia at 40-41 degrees C. Whole-body hyperthermia lasting for 4 h caused a decrease in the cytotoxic activity of liver sinusoidal washout cells against YAC-1 and K562 cells. Surprisingly, the percentage of washout cells with morphology of LGL (large granular lymphocyte) increased both in the liver washout and in portal blood compared to control normothermic animals. The proportions of phenotypically characterized cell subpopulations isolated from liver sinusoids did not change. Elimination of i.v. injected 125I-labelled K562 cells was decreased during hyperthermia. In vitro incubation of liver sinusoidal cytotoxic cells for 3 h at 41 degrees C decreased their cytotoxic activity by affecting the process of effector-target cell binding. However, once the effector-target cell conjugates were formed, the cytotoxic process proceeded as in normothermic conditions. These data suggest that inhibition of liver sinusoidal cytotoxic cell activity after hyperthermia may be a result of deficient target cell recognition by the effector cell.

Animals↗

PubMedDate not supplied

The treatment of lymphedema of the extremities with microsurgical lympho-venous anastomoses.

Personal 20-years clinical experience in diagnosis and treatment of various types of lymphedema of the lower limbs with microsurgical lymph node-vein and lymph vessel-vein anastomoses is presented. Optimizing of diagnostic method, improvements in operation technique and results of the follow-up have, during that period of time, modified indications for surgical therapy of lymphedema toward a more conservative approach and applying microsurgical methods to a carefully selected group. At present, lympho-venous shunts are performed in patients with local, segmental obstruction of proximal lymphatics. Peripheral lymph vessels should be patent and have their contractility at least partly preserved. Long-term penicillin therapy is indispensable prior to surgery in cases with a history of lymphangitis. The diagnostic procedures necessary for proper evaluation of the degree of lymph stasis, including the technique of lymph pressure and flow measurements are described. The details of operation of lymphovenous shunts based on personal experience are presented.

Anastomosis, Surgical↗