American journal of hematology
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Fas, a member of the tumor necrosis receptor superfamily, is 36 kD surface protein containing a single transmembrane region and induces apoptosis by Fas-Fas ligand binding. Soluble Fas (sFas) is produced as the form lacking 21 amino acid residues containing the transmembrane domain by alternative splicing. We found that the plasma sFas levels of 33 patients with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), 19 patients with disseminated intravascular coagulation (DIC), and 10 non-DIC patients with multiple organ failure (MOF) were significantly higher than those of 21 non-DIC patients without organ failure and those of 25 healthy volunteers. ⋯ The plasma thrombomodulin (TM) levels were increased significantly in the TTP/HUS patients, the DIC patients, and the non-DIC patients with MOF compared with the levels of the non-DIC patients without organ failure and the healthy volunteers. The plasma sFas antigen levels were correlated significantly with the plasma TM levels in all subjects. These findings suggest that the increases of sFas and sFas ligand that cause apoptosis might be related to the vascular endothelial cell injuries in TTP and DIC with organ failure.
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We retrospectively measured various hemostatic markers in 240 patients with disseminated intravascular coagulation (DIC) before the onset of DIC and in 110 non-DIC patients, and examined their usefulness for the diagnosis of pre-DIC. Changes in prothrombin time ratio and fibrinogen levels were not significant before the onset of DIC. The plasma levels of fibrinogen and fibrin degradation products before the onset of DIC were increased and the platelet count was gradually reduced in nonleukemic patients; these changes were already significant in the non-DIC state. ⋯ The positive rate of hemostatic markers for the diagnosis of DIC, TAT, and PPIC were high during the pre-DIC and non-DIC groups. The plasma levels of sFM and D-dimer were low in non-DIC and increased gradually during the pre-DIC state. These findings suggest that hemostatic molecular markers such as sFM, D-dimer, and TAT are useful for the diagnosis of pre-DIC, although their cutoff values were different among various diseases.
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Clinical Trial
Acute promyelocytic leukemia: all-trans retinoic acid (ATRA) along with chemotherapy is superior to ATRA alone.
This study was conducted to compare the results of treatment of acute promyelocytic leukemia (APL) with all-trans retinoic acid alone (ATRA) or a combination therapy of ATRA followed by chemotherapy. Forty-three patients treated between February 1992 and February 1996 were included in this study. Eighteen patients were treated with ATRA alone and 25 patients were treated with ATRA followed by chemotherapy. ⋯ The relapse-free survival is 42% at four years for patients treated with ATRA followed by chemotherapy. This trial is a historical comparison of ATRA alone and ATRA with subsequent combination chemotherapy. Nonetheless, the trial shows a significant improvement in the event free survival of patients receiving chemotherapy as consolidation following ATRA.
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Unexpectedly low hemoglobin oxygen saturation as determined by pulse-oximeter analysis was observed in a patient who underwent an elective surgical procedure. Specific hemoglobin derivatives such as carboxyhemoglobin, methemoglobin, and reduced hemoglobin that have been described to lower pulse-oximetry determination of oxygenation were not detected. Absorbance spectra revealed the patient's hemoglobin to be different than that obtained from two normal volunteers. ⋯ Hemoglobin Hammersmith and another unstable hemoglobin, hemoglobin Köln, have previously been described to have unexpectedly low pulse-oximeter-determined oxyhemoglobin levels. That we find hemoglobin Cheverly to result in a similar phenomenon suggests that pulse-oximeter monitoring of oxygenation status may not be appropriate for the unstable hemoglobins. Low pulse-oximeter oxygenation determinations for these hemoglobins do not appear to predict clinical hypoxemia.
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Disseminated intravascular coagulation (DIC) is a complex acquired coagulopathy resulting from excessive thrombin formation. Abnormal tissue factor (TF) expression is a major mechanism initiating DIC in many disorders, including obstetrical complications, sepsis, cancer, and trauma. ⋯ Treatment of DIC should focus on reversing the underlying disorder initiating the coagulopathy. Novel treatments are being investigated for treating DIC; many of these experimental modalities target the excessive TF activity that characterizes DIC.