Biomaterial Database

Reactivation of fetal erythropoiesis during the postnatal period. 1984

M Gahr, and G Herlemann

Using isopycnic gradient centrifugation, blood samples from adults, from umbilical cord, from newborn infants and from infants of different age group up to the age of 8 mo, were separated into seven fractions according to cellular age. We measured the number of erythrocytes and reticulocytes, mean cellular volume, mean cellular hemoglobin concentration, and the concentration of hemoglobin in each of the seven fractions. The distribution of erythrocytes within the gradient during postnatal aging revealed a bimodal distribution between 2-4 mo. Correspondingly, during the age of 2-8 mo the oldest cells did not contain the highest hemoglobin F concentration as was observed in the younger age group. From these data we conclude that the postnatal disappearance of hemoglobin F is not a continuous process.

UI	MeSH Term	Description	Entries
D007223	Infant	A child between 1 and 23 months of age.	Infants
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D002500	Centrifugation, Isopycnic	A technique used to separate particles according to their densities in a continuous density gradient. The sample is usually mixed with a solution of known gradient materials and subjected to centrifugation. Each particle sediments to the position at which the gradient density is equal to its own. The range of the density gradient is usually greater than that of the sample particles. It is used in purifying biological materials such as proteins, nucleic acids, organelles, and cell types.	Isopycnic Centrifugation
D004905	Erythrocyte Aging	The senescence of RED BLOOD CELLS. Lacking the organelles that make protein synthesis possible, the mature erythrocyte is incapable of self-repair, reproduction, and carrying out certain functions performed by other cells. This limits the average life span of an erythrocyte to 120 days.	Erythrocyte Survival,Aging, Erythrocyte,Survival, Erythrocyte
D004906	Erythrocyte Count	The number of RED BLOOD CELLS per unit volume in a sample of venous BLOOD.	Blood Cell Count, Red,Erythrocyte Number,Red Blood Cell Count,Count, Erythrocyte,Counts, Erythrocyte,Erythrocyte Counts,Erythrocyte Numbers
D004909	Erythrocyte Indices	ERYTHROCYTE size and HEMOGLOBIN content or concentration, usually derived from ERYTHROCYTE COUNT; BLOOD hemoglobin concentration; and HEMATOCRIT. The indices include the mean corpuscular volume (MCV), the mean corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC).	Erythrocyte Hemoglobin, Mean Cell,Erythrocyte Size Determination,Erythrocyte Volume, Mean Cell,Hemoglobin, Erythrocyte, Mean Cell,Mean Corpuscular Volume,Red Cell Indices,Erythrocyte Diameter,Erythrocyte Index,Erythrocyte Indexes,Erythrocyte Thickness,Mean Cell Hemoglobin Concentration,Mean Cell Volume,Mean Corpuscular Hemoglobin,Mean Corpuscular Hemoglobulin Concentration,Red Cell Distribution Width,Red Cell Index,Red Cell Indexes,Cell Volumes, Mean,Corpuscular Volumes, Mean,Determination, Erythrocyte Size,Determinations, Erythrocyte Size,Diameter, Erythrocyte,Diameters, Erythrocyte,Erythrocyte Diameters,Erythrocyte Size Determinations,Hemoglobin, Mean Corpuscular,Hemoglobins, Mean Corpuscular,Index, Erythrocyte,Index, Red Cell,Indexes, Erythrocyte,Indexes, Red Cell,Indices, Erythrocyte,Indices, Red Cell,Mean Cell Volumes,Mean Corpuscular Hemoglobins,Mean Corpuscular Volumes,Size Determination, Erythrocyte,Size Determinations, Erythrocyte,Thickness, Erythrocyte,Volume, Mean Cell,Volume, Mean Corpuscular,Volumes, Mean Cell,Volumes, Mean Corpuscular
D004911	Erythrocyte Volume	Volume of circulating ERYTHROCYTES . It is usually measured by RADIOISOTOPE DILUTION TECHNIQUE.	Red Cell Mass,Erythrocyte Volumes,Mass, Red Cell,Masses, Red Cell,Red Cell Masses,Volume, Erythrocyte,Volumes, Erythrocyte
D004912	Erythrocytes	Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.	Blood Cells, Red,Blood Corpuscles, Red,Red Blood Cells,Red Blood Corpuscles,Blood Cell, Red,Blood Corpuscle, Red,Erythrocyte,Red Blood Cell,Red Blood Corpuscle
D004920	Erythropoiesis	The production of red blood cells (ERYTHROCYTES). In humans, erythrocytes are produced by the YOLK SAC in the first trimester; by the liver in the second trimester; by the BONE MARROW in the third trimester and after birth. In normal individuals, the erythrocyte count in the peripheral blood remains relatively constant implying a balance between the rate of erythrocyte production and rate of destruction.	Erythropoieses
D005312	Fetal Blood	Blood of the fetus. Exchange of nutrients and waste between the fetal and maternal blood occurs via the PLACENTA. The cord blood is blood contained in the umbilical vessels (UMBILICAL CORD) at the time of delivery.	Cord Blood,Umbilical Cord Blood,Blood, Cord,Blood, Fetal,Blood, Umbilical Cord,Bloods, Cord,Bloods, Fetal,Bloods, Umbilical Cord,Cord Blood, Umbilical,Cord Bloods,Cord Bloods, Umbilical,Fetal Bloods,Umbilical Cord Bloods