Clonal hematopoiesis (CH) is associated with somatic mutations of the hematopoietic stem cells responsible for red blood cell formation. The incidence CH increases age and negative environmental factors. It particularly common in patients on chemotherapy, a greater than 10-fold increased risk hematological malignancy. also cardiovascular disease. Despite recent advances molecular genetic resear...

We examined long bones from 42 human embryos and fetuses whose gestational ages ranged from 6 to 28 weeks. Bone rudiment sections were stained using a panel of monoclonal antibodies directed at antigens expressed by hematopoietic cells, endothelial cells, smooth muscle cells, fibro-blasts, and stromal cells, to describe the events preceding and accompanying the onset of hematopoiesis in the dia...

Extra-medullary hematopoiesis occurring in spinal epidural space with resulting cord compression is rare. We report a case of extra-medullary hematopoiesis causing thoracic spinal cord compression in a patient of myelofibrosis. Because of atypical MRI findings, it posed a significant diagnostic challenge. Therefore, we have discussed MRI features of this rare complication in correlation with re...

Extramedullary hematopoiesis is a common phenomenon in thalassemia. During the disease there are very rare occasions when compensatory hematopoietic tissue is located in the intraspinal epidural space, causing spinal cord compression. This complication requires urgent neurosurgical consideration and decision for further treatment. We present a case of thoracic spinal cord compression secondary ...

Intrathoracic extramedullary hematopoiesis is an unusual but well-described entity. The condition is typically found in patients who have chronic hemolytic anemias, especially thalassemia. We report a case of a 38-year-old man with underlying beta thalassemia/hemoglobin E who developed intrathoracic extramedullary hematopoiesis. The hematopoietic masses spontaneously ruptured, resulting in mass...

Human CD34 (hCD34)-positive cells are used currently as a source for hematopoietic transplantation in humans. However, in steady-state murine hematopoiesis, hematopoietic stem cells (HSCs) with long-term reconstitution activity are found almost exclusively in the murine CD34 (mCD34)-negative to low fraction. To evaluate the possible differences in hCD34 and mCD34 gene expression in hematopoiesi...

Though discovered later than osteoblastic niche, vascular niche has been regarded as an alternative indispensable niche operating regulation on hematopoietic stem cells (HSCs). As significant progresses gained on this type niche, it is gradually clear that the main work of vascular niche is undertaking to support hematopoiesis. However, compared to what have been defined in the mechanisms throu...

The nature of hematopoietic stem cells under normal hematopoiesis remained largely unknown due to the limited assays available to monitor their behavior in situ. Here, we develop a new mouse model to transfer genes specifically into the primitive hematopoietic stem cell compartment through the utilization of a modified Rcas/TVA system. We succeeded in transferring a GFP reporter gene into adult...

The LIM-finger protein Lmo2, which is activated in T cell leukemias by chromosomal translocations, is required for yolk sac erythropoiesis. Because Lmo2 null mutant mice die at embryonic day 9-10, it prevents an assessment of a role in other stages of hematopoiesis. We have now studied the hematopoietic contribution of homozygous mutant Lmo2 -/- mouse embryonic stem cells and found that Lmo2 -/...

Polycythemia vera (PV) treatment with interferon α (IFNα) is frequently limited by dose-related toxicity. PV CD34(+) cells are characterized by overexpression of Bcl-xL, which can be antagonized by ABT-737 leading to apoptosis. We explored the effects of ABT-737 and IFNα on PV hematopoiesis. Both IFNα and ABT-737 alone or in combination had a modest effect on normal hematopoiesis but each indiv...