red blood cell formation occurs in red pulp in adults.
red blood cell formation occurs in red pulp in adults.
where does red blood cell formation occur in adults?
red pulp
most patients with "etv6-acsl6"-related disease present with findings similar to eosinophilia, hypereosinophila, or chronic eosinophilic leukemia; at least 4 cases presented with eosinophilia plus findings of the red blood cell neoplasm, polycythemia vera; three cases resembled acute myelogenous leukemia; and one case presented with findings of a combined myelodysplastic syndrome/myeloproliferative neoplasm. best treatments for "etv6-acsl6"-related disease are unclear. patients with the polycythemia vera form of the disease have been treated by reducing the circulating red blood cell load by phlebotomy or suppressing red blood cell formation using hydroxyurea. individual case studies report that "etv6-acsl6"-associated disease is insensitive to tyrosine kinase inhibitors. best treatment currently available, therefore, may involve chemotherapy and bone marrow transplantion.
clonal hypereosinophilia
ca iv has been identified in pulmonary epithelium of many mammalian species and may be uniquely adaptive for gas exchange necessary for the high metabolic requirements of mammals. a majority of the co2 produced by metabolism is transported as bicarbonate (hco3-). at the tissue capillary, co2 diffuses from tissue to plasma. other forms of carbonic anhydrase enzyme are not present in the plasma, restricting the equilibrium reaction of co2+h2o = h2co3 = h+ hco3-. co2 in the plasma diffuses into the red blood cell. ca is present within the red blood cell, facilitating the conversion of co2 to hco3-. hco3- so produced is transferred by the hco3-/cl- "shuttle" from the interior of the red blood cell to the plasma. hco3- doers not diffuse across cell membranes and, in the absence of ca, stays as hco3- and concentrates in plasma. up to 80% of metabolically produced co2 is transported in plasma in the form of hco3-. blood moves from the tissue capillary to the pulmonary capillary where co2 is exchanged at the lung. in the pulmonary capillary, bicarbonate can not simply diffuse either into the red blood cell or the alvioli. it is traditionally thought that hco3- is returned to the interior of the red blood cell by a reversal of the hco3-/cl- shuttle, where, in the presence of ca, it is returned to a co2 form to diffuse from the interior of the red blood cell, to the plasma and then into the alvioli. membrane bound ca (ca iv) on the luminal side of the pulmonary membrane would have direct contact with plasma hco3- and would enzimatically convert hco3- to co2 in the area immediately proximal to the exchange membrane, greatly increasing the concentration gradient for exchange. in this way, plasma hco3- can be converted to co2 within the plasma compartment and exchanged with the alvioli without the requirement of returning the hco3- to the interior of the red blood cell.
carbonic anhydrase 4