Browsing by Author "Rolovic, Z. (7006321033)"

[No abstract available]

Five instances of inhibitor to factor XII-XI have been reported so far. These have arisen in two women suffering from systemic lupus erythematosus and in three patients with Waldenstrom macroglobulinaemia. None of these patients had a bleeding tendency. The authors believe that it is of interest to report a 45-year-old female with an 18 years history of a bleeding tendency, who developed life-threatening vaginal bleeding following total hysterectomy for rupture of an ovarian cyst. Coagulation studies revealed a prolonged whole blood clotting time of 19 min and an activated partial thromboplastin time of 199 s (control 40 s). Further experiments showed that the patient's plasma at the dilution of 1:32 inhibited a contact product preparation thus indicating an inhibitor to factor XII-XI. The patient was treated with a variety of blood products without success but the administration of FEIBA 60 units/kg/d for 4 d was followed by the arrest of bleeding. The patient recovered completely. She had no evidence of an associated systemic disease but the inhibitor is still present in the plasma.

It was recently proposed that prolonged hypoxia produces hypomegakaryocytic thrombocytopenia by reducing the pool of committed megakaryocyte progenitor cells at the expense of a greatly expanded erythroid progenitor pool. In order to test this hypothesis we have studied the relationship between megakaryocytopoiesis, erythropoiesis, and granulopoiesis at the level of progenitor cells (megakaryocyte colony-forming units, CFU-Mk; erythroid CFU, CFU-E; erythroid burst-forming units; BFU-E; and granulocyte-macrophage CFU, CFU-GM) in the marrow of rats exposed for 4 weeks to normobaric hypoxia. We have found that hypomegakaryocytic thrombocytopenia was accompanied by decreased CFU-Mk, increased CFU-E, and a normal number of BFU-E and CFU-GM. These results support the hypothesis that prolonged hypoxia reduces the precursor cell commitment to differentiate into the megakaryocyte series by enhancing demand for differentiation into the erythroid cell line. However, the underlying mechanism needs further investigation.

It was recently proposed that prolonged hypoxia produces hypomegakaryocytic thrombocytopenia by reducing the pool of committed megakaryocyte progenitor cells at the expense of a greatly expanded erythroid progenitor pool. In order to test this hypothesis we have studied the relationship between megakaryocytopoiesis, erythropoiesis, and granulopoiesis at the level of progenitor cells (megakaryocyte colony-forming units, CFU-Mk; erythroid CFU, CFU-E; erythroid burst-forming units; BFU-E; and granulocyte-macrophage CFU, CFU-GM) in the marrow of rats exposed for 4 weeks to normobaric hypoxia. We have found that hypomegakaryocytic thrombocytopenia was accompanied by decreased CFU-Mk, increased CFU-E, and a normal number of BFU-E and CFU-GM. These results support the hypothesis that prolonged hypoxia reduces the precursor cell commitment to differentiate into the megakaryocyte series by enhancing demand for differentiation into the erythroid cell line. However, the underlying mechanism needs further investigation.

[No abstract available]

[No abstract available]