Megaloblastic anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types is a subset of macrocytic anemias that arises because of impaired nucleic acid synthesis Synthesis Polymerase Chain Reaction (PCR) in erythroid precursors. This impairment leads to ineffective RBC production and intramedullary hemolysis that is characterized by large cells with arrested nuclear maturation. The most common causes are vitamin B12 and folic acid deficiencies, which can be due to low dietary intake, underlying malabsorptive conditions, and medications. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor includes anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types and GI symptoms, with neurologic manifestations more commonly seen in B12 deficiency. Laboratory tests show macrocytic anemia Macrocytic anemia Anemia characterized by larger than normal erythrocytes, increased mean corpuscular volume (MCV) and increased mean corpuscular hemoglobin (mMCH). Anemia: Overview and Types (elevated mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion corpuscular volume) and low B12 and folate Folate Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects. Folate and Vitamin B12 levels. Confirmatory tests can be performed if levels are borderline. Treatment focuses on identifying the cause of the deficiency and replacing the deficient vitamin either orally or parenterally.
Last updated: 23 Apr, 2021
Megaloblastic anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types is a subset of macrocytic anemias characterized by increased RBC size and an arrest in nuclear maturation arising from abnormal cell division Cell Division A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. Cell Cycle in erythroid precursors.
Role of
vitamin B12
Vitamin B12
A cobalt-containing coordination compound produced by intestinal microorganisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. Intrinsic factor is important for the assimilation of vitamin B 12.
Folate and Vitamin B12 and folic acid in
DNA
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
DNA Types and Structure
synthesis
Synthesis
Polymerase Chain Reaction (PCR):
From the bottom:
Dietary
folate
Folate
Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects.
Folate and Vitamin B12 is absorbed in the intestine in the form of 5-methyl-tetrahydrofolate (THF).
Vitamin B12
Vitamin B12
A cobalt-containing coordination compound produced by intestinal microorganisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. Intrinsic factor is important for the assimilation of vitamin B 12.
Folate and Vitamin B12–dependent methionine synthetase converts 5-methyl-THF to THF. The same process generates methionine from homocysteine and methionine converts to S-adenosylmethionine or
SAM
SAM
Anterior displacement of the mitral valve during systole.
Hypertrophic Cardiomyopathy (also necessary for
DNA
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
DNA Types and Structure
methylation
Methylation
Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. .
Glucocorticoids).
The THF produced is converted to 5, 10-methylene-THF.
A methyl group is donated from methylene-THF to the 5-carbon of uridylate to form thymidylate.
As a consequence of donating the methyl group, methylene-THF becomes dihydrofolate.
Dihydrofolate is reduced by reductase to re-generate
tetrahydrofolate
Tetrahydrofolate
Sulfonamides and Trimethoprim.
Rapidly dividing cells in the body are most sensitive to impaired DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure synthesis Synthesis Polymerase Chain Reaction (PCR) due to B12 and folate Folate Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects. Folate and Vitamin B12 deficiency.
Hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi in a patient with vitamin B12 deficiency
Image: “Peculiar cutaneous hyperpigmentation Hyperpigmentation Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance. Malassezia Fungi from cases with megaloblastic anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types” by Department of Pathology, Pondicherry Institute of Medical Sciences, Puducherry, India. License: CC BY 2.0Peripheral-blood smear with hypersegmented neutrophil
Image: “Hyperlobated neutrophil” by Ed Uthman. License: CC BY 2.0Peripheral-blood smear showing macrocytosis with anisopoikilocytosis and one hypersegmented neutrophil
Image: “Peripheral smear of case 2 demonstrated macrocytosis” by Department of Geriatric Medicine, Ohio University College of Osteopathic Medicine, Athens, OH, USA. License: CC BY 2.0
Bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types marrow
biopsy
Biopsy
Removal and pathologic examination of specimens from the living body.
Ewing Sarcoma:
A:
Bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types marrow aspirate
B: Hypercellularity and megaloblasts (arrow)
C: Giant abnormally shaped stab forms (arrow)