Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cell adhesion molecule L-selectin is highly expressed on mature bone marrow polymorphonuclear leukocytes (PMN), and the release of these cells from the bone marrow could produce a population of circulating PMN expressing high levels of L-selectin. Because L-selectin initiates the interaction of PMN with activated endothelium, these cells could be important in the pathogenesis of multiorgan failure following sepsis and septic shock. The present study was designed to test the hypothesis that the release of PMN from the bone marrow increases the expression of L-selectin on circulating PMN. Peripheral blood and bone marrow samples were obtained immediately after sternotomy (BM1) and during (BM2) and just before closing the sternum (BM3) in five normothermic and five hypothermic cardiopulmonary bypass (CPB) procedures. L-selectin was measured using both immunocytochemistry and flow cytometry. The results showed that L-selectin expression on bone marrow PMN was greater than on peripheral blood PMN (p < 0.01) in all patients at baseline. Bone marrow release of PMN during normothermic CPB was associated with a rise in peripheral blood band cells (0.18 +/- 0.7 versus 0.56 x 10(9)/L) (p < 0.01) and an increase in the percentage of PMN expressing high levels of L-selectin (9 +/- 3.3 to 36 +/- 6.6%, p < 0.03) and the L-selectin mean fluorescence intensity (MFI) on PMN (p < 0.05). The expression of L-selectin on band cells was higher than on segmented PMN in the circulation (p < 0.01). Hypothermia (27 degrees C) prevented the release of band cells into the circulation and the increased expression of L-selectin on the PMN.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:L-selectin expression increases on peripheral blood polymorphonuclear leukocytes during active marrow release. 753 Oct 98

Children undergoing cardiopulmonary bypass (CPB) surgery for congenital heart defects develop an acute post-operative capillary leak which may be due to endothelial injury inflicted by adherent neutrophils (PMN). Direct immunofluorescence and flow cytometry were used to measure CD11a/CD18, CD11b/CD18 and L-selectin (L-s) expression on circulating PMN in CPB circuits containing human blood and in children undergoing CPB. In vitro, a general rise in CD11b/CD18 expression over 2 h contrasted with complete loss of L-s in a small but progressively increasing proportion of PMN. Marked but inconsistent changes in CD11b/CD18 and L-s were observed in vivo, in conjunction with fluctuations in circulating PMN count. Circulating IL-8 was detected starting at rewarming from hypothermia and reperfusion of the heart and lungs with a simultaneous, closely correlated rise in both PMN count and circulating elastase. IL-1 and TNF were not detected. These studies demonstrate changes in the pathways of PMN-endothelial interaction during and after CPB.
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PMID:Changes in neutrophil CD11b/CD18 and L-selectin expression and release of interleukin 8 and elastase in paediatric cardiopulmonary bypass. 768 23

Previous studies from our laboratory have shown that the expression of L-selectin on polymorphonuclear leukocytes (PMN) is higher in the bone marrow than in peripheral blood. The present study was designed to determine the location of this L-selectin loss as the PMN pass from the hematopoietic tissue into venous sinusoids of the bone marrow. Bone marrow and peripheral blood samples were collected at the beginning, during, and just after five normothermic cardiopulmonary bypass procedures in which there was active marrow release and compared with five hypothermic procedures in which marrow release was suppressed by lowering body temperature to 27 degrees C. L-selectin expression was measured on PMN in the hematopoietic tissue and venous sinusoids in the bone marrow using quantitative histology and immunocytochemistry. At baseline there was more L-selectin on PMN in the bone marrow hematopoietic tissue than in the sinusoids (24.7 +/- 3.5 vs. 10.3 +/- 2.5%, P < 0.004). Bone marrow release during normothermic cardiopulmonary bypass procedure was associated with a rise in peripheral blood band cells (0.18 +/- 0.7 vs. 2.98 +/- 0.56 x 10(9)/l, P < 0.01) and a further reduction of L-selectin expression on PMN in the sinusoids (P < 0.03). Hypothermia (27 degrees C) prevented both the rise in peripheral blood band cells and the reduction in L-selectin on PMN in the sinusoids. In vitro studies showed that lowering the temperature had a similar effect on shedding of L-selectin from PMN. We conclude that PMN shed L-selectin as they move from the hematopoietic compartment into the venous sinusoids of the bone marrow and postulate that this could control the release of PMN from the marrow.
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PMID:A possible role for L-selectin in the release of polymorphonuclear leukocytes from bone marrow. 913 55

A consequence of cardiopulmonary bypass (CPB) in young children is postoperative capillary leak and associated pulmonary dysfunction. Neutrophils sequester in the lungs and may contribute to functional endothelial damage. The endothelial adhesion molecules, E-selectin and intercellular adhesion molecule-1 (ICAM-1), mediate sequential steps in adhesion by binding to leucocyte ligands. Circulating forms of these proteins have been identified. We studied changes in the plasma concentrations of soluble E-selectin and soluble ICAM-1 using fixed phase immunoassays, and associated leucocyte counts in 10 paediatric patients undergoing CPB. Concentrations of soluble L-selectin and soluble ICAM-1 consistently fell during CPB from preoperative levels of 89 +/- 17 ng/ml (mean +/- 2SEM) and 218 + 61 ng/ml, respectively, to 39 +/- 7 ng/ml and 84 +/- 24 ng/ml, respectively at the beginning of maximum hypothermia. The haemodilution that occurred during CPB largely explained this fall, but not the more marked decrease in white cell counts that also occurred over this period (6.7 +/- 1.1 to 1.7 +/- 0.5 x 10(9)/l) which may reflect increased leucocyte sequestration. By 24 h postoperatively, levels of both soluble adhesion molecules approached preoperative concentrations, as did lymphocyte counts. In marked contrast, neutrophil counts rose appreciably towards the end of CPB, and continued to rise to a maximum of 10.9 +/- 3.1 x 10(9)/l during the immediate postoperative period and remained at these elevated levels 24 h later. Major consistent changes in circulating leucocyte numbers which occur early in cardiopulmonary bypass may reflect changes in adhesion to the endothelium and consequent sequestration. Alterations in the levels of soluble adhesion proteins may influence these processes.
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PMID:Changes in leucocyte counts and soluble intercellular adhesion molecule-1 and E-selectin during cardiopulmonary bypass in children. 977 16