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Query: UMLS:C0012739 (
disseminated intravascular coagulation
)
8,673
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We examined red cell fragmentation syndrome (RCFS) induced by mitomycin C (MMC) (13 patients), by thrombotic thrombocytopenic purpura (TTP) (17 patients), and by
disseminated intravascular coagulation
(
DIC
) (15 patients). Plasma cytokine levels were increased in the TTP and
DIC
patients, but not in those whose RCFS was induced by MMC, suggesting that the activation of the immune system plays an important role in the pathogenesis of RCFS due to TTP and
DIC
but did not in RCFS due to MMC. Plasma thrombomodulin, tissue type plasminogen activator, and plasminogen activator inhibitor-I levels were increased in all RCFS patients, suggesting that RCFS, whether MMC induced, or due to TTP or
DIC
, might be associated with vascular endothelial cell injury. In TTP,
von Willebrand factor
(
vWF
) antigen and high molecular weight
vWF
multimer levels were reduced, possibly as a result of microthrombus consumption. The hemostatic data in this study showed that the TTP patients were in a hypercoagulable state without hyperfibrinolysis, and that
DIC
patients were in both a hypercoagulable and a hyperfibrinolytic state, whereas hemostatic abnormalities were slight in patients with MMC induced RCFS. These findings suggest that vascular endothelial cell injuries might be associated with RCFS, and that those injuries in MMC-induced RCFS might not be related to microthrombi or an activated immune system.
...
PMID:Hemostatic abnormalities and increased vascular endothelial cell markers in patients with red cell fragmentation syndrome induced by mitomycin C. 748 97
Healthy endothelium is a metabolically active interface between the blood and extravascular tissues. Its intimal surface is anticoagulant and antithrombotic, and it secretes a variety of molecules involved in regulating platelet function and blood coagulation. The rapid interactions between platelets, their secreted components, or thrombin and endothelial cells at sites of vessel damage ensure the local secretion of mediators such as prostacyclin and nitric oxide that limit the intravascular growth of the haemostatic plug. There is considerable evidence that a decreased ability of endothelial cells to synthesize NO contributes to the pathogenesis of arterial disease. Local deficiency of PGI2 synthesis has also been implicated in the thrombotic problems in haemolytic uraemic syndrome. Endothelium is also the source of circulating
von Willebrand factor
, important for efficient platelet adhesion. Chronically elevated plasma levels of vWF in a series of diseases where there is vascular pathology apparently reflect endothelial cell damage or activation, and may contribute to the prothrombotic tendency they exhibit. They may be compounded by decreased levels of the surface anticoagulant thrombomodulin, if the increased concentrations of the soluble forms of thrombomodulin detected in the circulation under similar conditions are a reflection of loss from the endothelium. Further alterations of function in a procoagulant/prothrombotic direction take place when endothelial cells are exposed to certain cytokines or lipopolysaccharide. Tissue factor synthesis is induced, thrombomodulin expression is decreased, and there is enhanced sensitivity of vWF secretion. In addition, the balance of tissue-type plasminogen activator and plasminogen activator inhibitor type I secretion is changed in favour of the latter. These processes are each likely to contribute to the occurrence of
disseminated intravascular coagulation
which can accompany septic shock.
...
PMID:Endothelial cell function and thrombosis. 784 94
We examined various markers in 17 patients with thrombotic thrombocytopenic purpura (TTP), 13 with red cell fragmentation syndrome (RCFS) induced by mitomycin C, and 36 with RCFS caused by
disseminated intravascular coagulation
(
DIC
). A platelet activating factor and decrease of
von Willebrand factor
were frequently observed in patients with TTP, but were not in those with RCFS due to either mitomycin C or
DIC
. Since increased vascular endothelial cell markers and decreased MTT assay were observed in patients with TTP, it is considered that vascular endothelial cell injury is associated with patients with TTP. The increased plasma cytokines and the hypercoagulable and hypofibrinolytic state indicates that the vascular endothelial cell injury might be caused by microthrombus or activated immune system. Although patients with TTP were treated with plasma exchange, anti-platelet therapy, and high dose steroid therapy, the mortality was still high.
...
PMID:[Plasma level of various markers in patients with thrombotic thrombocytopenic purpura]. 802 79
We found that patients with thrombotic thrombocytopenic purpura (TTP) have significantly elevated plasma thrombin antithrombin III complex (TAT) and FDP-D-dimer levels, while the plasmin-alpha 2 plasmin inhibitor complex (PIC) level was only slightly increased. The tissue-type plasminogen activator (t-PA) level was increased, but it was well correlated with the plasminogen activator inhibitor-I (PAI-I) level. These findings suggest that hypercoagulable and hypofibrinolytic states coexist in these patients, in contrast to patients with
disseminated intravascular coagulation
, who exhibit coexisting hypercoagulable and hyperfibrinolytic states. Levels of vascular endothelial cell markers, such as PAI-I, thrombomodulin (TM), and t-PA, were increased at the onset of TTP, but the level of
von Willebrand factor
(
vWF
) antigen was not increased. The outcome in TTP patients was correlated with plasma t-PA and TM levels but not with TAT or PIC. These results suggest that vascular endothelial cell markers, such as TM and t-PA, are released from injured or stimulated endothelial cells, reflecting the degree of vascular endothelial damage, and that the main factor in the pathogenesis of TTP is vascular endothelial cell injury.
...
PMID:Increased levels of vascular endothelial cell markers in thrombotic thrombocytopenic purpura. 826 13
We examined vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-I (PAI-I), tissue plasminogen activator (t-PA), and
von Willebrand factor
, in 80 patients with
disseminated intravascular coagulation
(
DIC
). The levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and FDP-D-dimer were significantly increased both before and after the onset of
DIC
, but were not correlated with organ failure or prognosis. However, the PIC/TAT ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without. Plasma TM, PAI-I, and t-PA levels were increased in
DIC
patients with organ failure or poor outcome, but were not significantly increased before the onset of
DIC
. We consider that the prognosis of patients with
DIC
might be related to organ failure or endothelial cell damage and that plasma levels of TM, PAI-I, and t-PA might be useful in the detection of these disorders and in assessing prognosis. A hypofibrinolytic state might enhance organ failure in patients with
DIC
.
...
PMID:Increased vascular endothelial cell markers in patients with disseminated intravascular coagulation. 826 24
The bleeding diathesis in patients with acute promyelocytic leukemia (APL) is generally attributed to
disseminated intravascular coagulation
(
DIC
), initiated by the release of procoagulant activity from leukemic cells. Primary fibrinogenolysis, mediated by the release of leukocyte proteases, may also contribute to this disorder. We analyzed coagulation parameters in 15 non-septic APL patients. Before treatment, there was evidence of thrombin activation with
DIC
: increased levels of circulating thrombin-antithrombin III complexes, prothrombin fragments 1 + 2 and D-Dimer complexes. This
DIC syndrome
was probably limited, since no prothrombin time decrease, no significant factor V consumption, and normal levels of coagulation inhibitors (antithrombin III and protein C) were observed in APL patients when compared to normal controls. In this context, marked hypofibrinogenemia suggested primary fibrinogenolysis as the predominant etiology. Despite normal or high tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI-1) antigen levels, the plasma PAI-1 activity and the formation of tPA/PAI-1 complexes were lower in APL patients than in normal controls, suggesting a proteolytic degradation of PAI-1, not able to complex tPA. Two other fibrinolytic inhibitor molecules (alpha-2 plasmin inhibitor antigen and histidine-rich glycoprotein antigen) were also significantly reduced, as well as the two subunits of fibrin stability factor XIII, although only subunit A is known to be susceptible to thrombin action. Evidence of degraded forms of
von Willebrand factor
in the plasma suggested an extended proteolytic activity. Four patients treated with all-trans-retinoic acid (ATRA) as a single differentiating agent were studied serially. A dissociation between these two syndromes--
DIC
and fibrinogenolysis/proteolysis--was observed. The rapid correction of the lysis markers contrasted with a more prolonged persistence of the procoagulant activity. We observed persistently high elastase/alpha 1-proteinase inhibitor complex levels during ATRA therapy, despite progressive correction of all lysis markers. Thus, the release of elastase from promyelocytic leukemic cells is probably not the only determinant of the fibrinogenolytic/proteolytic syndrome. In summary, the present findings provide new arguments for the association of
DIC
and proteolysis syndromes in APL-associated coagulation disorders. Further prospective studies are needed in order to confirm the persistence of thrombin activation in course of ATRA therapy.
...
PMID:Coagulation disorders associated with acute promyelocytic leukemia: corrective effect of all-trans retinoic acid treatment. 841 75
After clinical assessment, pertinent history, and family history, the clinician often has a good idea concerning the cause of a patient's bleeding. The most appropriate laboratory tests can then be ordered. Routine screening tests include a complete blood cell count, platelet count, and evaluation of a peripheral blood sample, a prothrombin time, and an activated partial thromboplastin time. Thrombocytopenia may result from idiopathic thrombocytopenic purpura,
disseminated intravascular coagulation
, or, less commonly, acute leukemia, aplastic anemia, thrombotic thrombocytopenic purpura, or a particular drug that a patient is taking. Again, the patient's history, physical findings, and evaluation of a well-prepared peripheral blood smear will be helpful in determining the cause of the patient's thrombocytopenia. An isolated prolongation of the activated partial thromboplastin time may result from low levels of factors VIII, IX, or XI. A slightly prolonged activated partial thromboplastin time and a moderate decrease in factor VIII may reflect von Willebrand disease or the "carrier" state for hemophilia A. In women a greatly prolonged activated partial thromboplastin time and very low levels of factor VIII (< 3%) most often result from an acquired factor VIII inhibitor (autoantibody against factor VIII) or from severe (type III) von Willebrand disease. If von Willebrand disease is suspected (because of menorrhagia with or without other mucous membrane bleeding, a positive family history, and a prolonged activated partial thromboplastin time), more specific laboratory tests for this disease should be done. These include assays of factor VIII,
von Willebrand factor
antigen,
von Willebrand factor
activity (measured by the ristocetin cofactor assay), and template bleeding time. In von Willebrand disease the defect is in
von Willebrand factor
. The affected individual may have subnormal levels of structurally and functionally normal
von Willebrand factor
(this is called "classic" or type I von Willebrand disease) or may produce
von Willebrand factor
that is structurally and functionally abnormal (von Willebrand disease type 2). Individuals who inherit a gene for von Willebrand disease from both parents have severe (type 3) von Willebrand disease and will have extremely low levels (< 3%) of
von Willebrand factor
and factor VIII and will have a very prolonged bleeding time. In most populations type I disease is the most common form, whereas type 3 is the least commonly encountered form. It should be noted that levels of
von Willebrand factor
can be influenced by the patient's blood type (persons who have blood type AB have 60% to 70% higher levels than do persons who have blood type O) and can be elevated during pregnancy, stress, and hyperthyroidism. The two major functions of
von Willebrand factor
are to serve as a "bridge" between platelets and injury sites in blood vessel walls and to protect circulating factor VIII from rapid proteolytic degradation. Thus, if a patient has either too little or functionally abnormal
von Willebrand factor
, the bleeding time will be prolonged and factor VIII will be decreased (because it is not being protected by
von Willebrand factor
). It should be determined which type of von Willebrand disease a particular patient has because treatment depends on type. Multimeric analysis of
von Willebrand factor
can be done with use of sodium dodecyl sulfate gels, radiolabeled antibody to von Willebrand's factor, and autoradiography. This will allow visualization of the multimeric structure of
von Willebrand factor
. In type I disease all bands are present, whereas in the type 2 variants 2A and 2B no high-molecular-weight multimers are seen. Desmopressin acetate (which is available in parenteral form for intravenous use and in a highly concentrated intranasal spray formulation) is the treatment of choice for classic type I disease. The drug effects a rapid release of
von Willebrand factor
from endothelial cell stor
...
PMID:Screening and diagnosis of coagulation disorders. 882 61
Coagulation activation and fibrinolysis parameters were studied in eleven cases of thrombotic microangiopathy concerning eight adult patients. In addition to routine coagulation tests, antithrombin III,
von Willebrand factor
(
vWF
), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), D-dimer (DD), and plasminogen activator inhibitor type 1 (PAI-1) were measured in the plasma at the time of diagnosis and as soon as remission was achieved after therapy with plasma exchange and Iloprost. In the acute phase all patients showed normal aPTT, normal or slightly prolonged prothrombin time, normal or enhanced plasma levels of fibrinogen and antithrombin III, at variance with results in patients affected by
disseminated intravascular coagulation
. Mean F1+2, TAT, DD,
vWF
and PAI-1 were elevated in the acute phase, but decreased significantly in the early phase of remission. Our data provide evidence of increased thrombin generation rate which takes place in the acute phase of the disease and does not result in
consumption coagulopathy
, due to appropriate inhibition by antithrombin III; blood coagulation activation promptly decreased as soon as remission was achieved. Cross-linked fibrin deposition together with PAI-1 may consolidate the platelet plug, eventually resulting in microvascular occlusion and ischemia.
...
PMID:Plasmatic parameters of coagulation activation in thrombotic microangiopathy. 895 55
Elevated plasma concentrations of
von Willebrand factor
(vWf) are increasingly recognized as a cardiovascular risk factor, and are used as a marker of endothelial activation. However, the factors which determine the rate of vWf release from the endothelium in vivo have not been defined clearly. In addition, vWf plasma levels may also be influenced by adhesion of vWf to the vascular wall or to platelets, and by its rate of degradation. The propeptide of vWf (also called vWf:AgII) is stored and released in equimolar amounts with vWf. In the present study we attempted to determine whether this propeptide could be a more reliable marker of endothelial secretion than vWf itself. To accomplish this we developed an ELISA based on monoclonal antibodies. The propeptide levels in normal plasma were found to be 0.7 microgram/ml, more than 10 times lower than vWf itself. Administration of desmopressin (DDAVP) induced a rapid relative increase in propeptide (from 106 to 879%) and in vWf (from 112 to 272%). However, the increases in vWf and propeptide were equivalent when expressed in molar units. A time course study indicated a half-life of the propeptide of 3 h or less. In a baboon model of
disseminated intravascular coagulation
(
DIC
) induced by FXa, vWf increased by less than 100%, whereas the propeptide concentrations increased by up to 450%. In view of the massive thrombin generation (as assessed by fibrinogen depletion), the increases in vWf are small, compared to the strong secretory response to thrombin and fibrin previously observed in vitro. Our results suggest that due to its rapid turnover, the propeptide could provide a sensitive plasma marker of acute endothelial secretion.
...
PMID:Acute von Willebrand factor secretion from the endothelium in vivo: assessment through plasma propeptide (vWf:AgII) Levels. 915 1
Important mechanisms underlying immediate xenograft loss by hyperacute rejection (HAR), in the pig-to-primate combination, have been recently delineated. There are now several proposed therapies that deal with the problem of complement activation and xenoreactive natural antibody (XNA) binding to the vasculature that have been shown to prevent HAR. However, vascularized xenografts are still lost, typically within days, by delayed xenograft rejection (DXR), alternatively known as acute vascular rejection (AVR). This process is characterized by endothelial cell (EC) perturbation, localization of XNA within the graft vasculature, host NK cell and monocyte activation with platelet sequestration and vascular thrombosis. Alternative immunosuppressive strategies, additive anti-complement therapies with the control of any resulting EC activation processes and induction of protective responses have been proposed to ameliorate this pathological process. In addition, several potentially important molecular incompatibilities between activated human coagulation factors and the natural anticoagulants expressed on porcine EC have been noted. Such incompatibilities may be analogous to cross-species alterations in the function of complement regulatory proteins important in HAR. Disordered thromboregulation is potentially relevant to the progression of inflammatory events in DXR and the
disseminated intravascular coagulation
seen in primate recipients of porcine renal xenografts. We have recently demonstrated the inability of porcine tissue factor pathway inhibitor (TFPI) to adequately neutralize human factor Xa (FXa), the aberrant activation of both human prothrombin and FXa by porcine EC and the failure of the porcine natural anticoagulant, thrombomodulin to bind human thrombin and hence activate human protein C. The enhanced potential of porcine
von Willebrand factor
to associate with human platelet GPIb has been demonstrated to be dependent upon the isolated A1 domain of
von Willebrand factor
. In addition, the loss of TFPI and vascular ATPDase/CD39 activity following EC activation responses would potentiate any procoagulant changes within the xenograft. These developments could exacerbate vascular damage from whatever cause and enhance the activation of platelets and coagulation pathways within xenografts resulting in graft infarction and loss. Analysis of these and the other putative factors underlying DXR should lead to the development and testing of genetic approaches that, in conjunction with selected pharmacological means, may further prolong xenograft survival to a clinically relevant extent.
...
PMID:Factors in xenograft rejection. 1041 73
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