Blood
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Hemorrhagic shock suppresses the ability of Kupffer cells (KC) to present antigen and express the major histocompatibility complex class II (Ia) antigen. These alterations are concomitant with an enhanced release of cytokines (tumor necrosis factor [TNF], interleukin-1 [IL-1], IL-6) and prostaglandin E2 (PGE2) by KC after hemorrhagic shock. The aim of this study was to determine whether chloroquine (CQ) administration in vivo before or after hemorrhage affects the altered cytokine and PGE2 release by KC as well as the capacity of KC to present antigen and express Ia. ⋯ Furthermore, the data suggest that the suppression of KC functions occurs during or after resuscitation, because posttreatment with CQ was as effective as pretreatment. Additional studies indicated that the survival of animals after hemorrhage and sepsis was significantly increased by posttreatment of hemorrhaged mice with CQ. Thus, CQ, because of its unique ability to selectively inhibit the release of inflammatory cytokines and prostaglandins, represents a potent immunomodulating agent in the treatment of conditions associated with increased cytokine release and for decreasing the mortality from sepsis after hemorrhage.
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Platelet von Willebrand factor (vWF) has been suggested to play an important role in the hemostatic process. Clinical and experimental data indicate that bleeding time (BT) and platelet-vessel wall interaction cannot be normalized unless the defect of platelet vWF is also corrected. We have examined the effect of normal platelet concentrate transfusion 1 hour after cryoprecipitate infusion in five type III von Willebrand disease (vWD) patients. ⋯ In the perfusion study, cryoprecipitate infusion only resulted in a slight increase in platelet deposition (surface coverage range: 2.4% to 11.3%), whereas the platelet concentrate transfusion elicited a more marked improvement (range: 8.2% to 26.4%; P less than .02 v post-cryoprecipitate). These results suggest an important in vivo role of the platelet vWF in supporting platelet-vessel wall interaction. They also give support to the occasional addition of normal platelet transfusion to the cryoprecipitate infusion for the control of serious bleeding episodes resistant to cryoprecipitate in severe vWD patients.
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In disseminated intravascular coagulation (DIC) with acute promyelocytic leukemia (APL) in the absence of severe infection, marked fibrinolysis was noted in comparison with normal levels of antithrombin III, which is a major inhibitor of the coagulation system. Increased plasminogen activator inhibitor-1 (PAI-1) antigen levels in plasma from patients with septicemia decreased the ratio of the plasma clot lysis rate induced by an anti-alpha 2-plasmin inhibitor monoclonal antibody to the tissue-type plasminogen activator (t-PA) concentration. This decrease was not as prominent in plasma from patients with DIC, especially those with APL. ⋯ The specific activity of PAI-1 decreased in patients with DIC (43.7% +/- 30.6%) and in DIC cases with APL (10.3% +/- 6.0%) in comparison to patients with septicemia (83.7% +/- 20.2%) or normal controls (85.8% +/- 27.3%). In DIC associated with APL, degraded forms of PAI-1 were detected in plasma by immunoblotting. These results suggest that a decrease in the specific activity of PAI-1 and an increase in secondary fibrinolysis result in a hyperfibrinolytic state in DIC patients with APL.
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Randomized Controlled Trial Clinical Trial
Comparison of the hemostatic effects of fresh whole blood, stored whole blood, and components after open heart surgery in children.
In a double-blind study, we compared the postoperative (post-op) blood loss in 161 children undergoing open heart surgery with cardiopulmonary bypass whose immediate post-op transfusion requirements were met with either very fresh whole blood (VFWB), 24- to 48-hour-old whole blood or reconstituted whole blood (packed red blood cells, fresh frozen plasma [FFP], and platelets). Assignment to treatment groups was not strictly random but dependent, in part, on the ability of families to provide directed donors for fresh blood. The three patient groups were comparable with respect to patient age, pre-op coagulation profiles (bleeding time, prothrombin time, activated partial thromboplastin time, platelet count, fibrin split products, fibrinogen, and platelet aggregation tests) difficulty of operative procedures and time spent on CPB. ⋯ Comparison of other post-op coagulation tests could not explain the increased blood loss in the reconstituted group. We conclude that the transfusion of less than 48 hours old whole blood is associated with significantly less post-op blood loss than the transfusion of packed red blood cells, FFP, and platelets in children under 2 years old who underwent complex cardiac surgery. The blood losses associated with the transfusion of VFWB and 24- to 48-hour-old blood are comparable and may be, in part, due to better functioning platelets.
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In washed platelet systems, thrombin has been demonstrated to downregulate the platelet surface expression of glycoprotein (GP) Ib and GPIX. In the present study, we addressed the question as to whether, in the more physiologic milieu of whole blood, downregulation of platelet surface GPIb and GPIX can be induced by thrombin, adenosine diphosphate (ADP), and/or by an in vivo wound. Thrombin-induced downregulation of GPIb and GPIX on the surface of individual platelets in whole blood was demonstrated by the use of flow cytometry, a panel of monoclonal antibodies (MoAbs) and, to inhibit fibrin polymerization, the peptide glycyl-L-prolyl-L-arginyl-L-proline. ⋯ However, degranulation was not a prerequisite because ADP downregulated platelet surface GPIb-IX without exposing GMP-140 on the platelet surface. Inhibitory effects of cytochalasins demonstrated that the activation-induced downregulation of both GPIX and GPIb are dependent on actin polymerization. In summary, downregulation of the platelet surface GPIb-IX complex occurs in whole blood stimulated by thrombin, ADP, or an in vivo wound, and is independent of alpha granule secretion.