Biomaterial Database

In vitro DNA synthesis by bone marrow cells and PHA-stimulated lymphocytes. Suppression by nonradioactive thymidine of the incorporation of 3H-deoxyuridine into DNA: enhancement of incorporation when inadequate vitamin B12 or folate is corrected. 1980

K C Das, and C Manusselis, and V Herbert

Previous studies demonstrated that excess deoxyuridine (dU) added to short-term bone marrow and PHA-stimulated lymphocyte cultures, blocks the incorporation of radioactive thymidine into DNA via the salvage pathway. In the current study, we investigated the effects of added thymidine (TdR) in varying concentrations (10(-6) to 1 mumol) on the incorporation of 3H-dU into thymine-DNA, i.e. we executed 'thymidine suppression tests.' Increasing concentrations of exogenous TdR caused progressive inhibition of 3H-dU incorporation into DNA, and decreasing 3H-dU incorporation was parallelled by increasing incorporation of added 14C-TdR. These findings demonstrate reciprocity of the salvage and the de novo pathways of thymine-DNA synthesis, presumably mediated by thymidine-triphosphate (dTTP), the common end product of both pathways, via feedback inhibition. In patients with folate and/or vitamin B12 deficiency, the addition of appropriate vitamins to marrow and lymphocyte cultures enhanced the incorporation of 3H-dU into DNA. As predicted, this was not observed in normal subjects. The enhancing effect of these vitamins on in vitro incorporation of 3H-dU into DNA by deficient cell systems was similar to their correcting effect on abnormal dU suppression. These findings support the theoretical concept that the dU suppression test defines biochemical megaloblastosis due to deficiency of folate and vitamin B12.

UI	MeSH Term	Description	Entries
D008214	Lymphocytes	White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.	Lymphoid Cells,Cell, Lymphoid,Cells, Lymphoid,Lymphocyte,Lymphoid Cell
D010835	Phytohemagglutinins	Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.	Kidney Bean Lectin,Kidney Bean Lectins,Lectins, Kidney Bean,Phaseolus vulgaris Lectin,Phaseolus vulgaris Lectins,Phytohemagglutinin,Hemagglutinins, Plant,Lectin, Kidney Bean,Lectin, Phaseolus vulgaris,Lectins, Phaseolus vulgaris,Plant Hemagglutinins
D001853	Bone Marrow	The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.	Marrow,Red Marrow,Yellow Marrow,Marrow, Bone,Marrow, Red,Marrow, Yellow
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D003857	Deoxyuridine	2'-Deoxyuridine. An antimetabolite that is converted to deoxyuridine triphosphate during DNA synthesis. Laboratory suppression of deoxyuridine is used to diagnose megaloblastic anemias due to vitamin B12 and folate deficiencies.	(beta 1-(2-Deoxyribopyranosyl))thymidine
D004247	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, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005492	Folic Acid	A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.	Pteroylglutamic Acid,Vitamin M,Folacin,Folate,Folic Acid, (D)-Isomer,Folic Acid, (DL)-Isomer,Folic Acid, Calcium Salt (1:1),Folic Acid, Monopotassium Salt,Folic Acid, Monosodium Salt,Folic Acid, Potassium Salt,Folic Acid, Sodium Salt,Folvite,Vitamin B9,B9, Vitamin
D005494	Folic Acid Deficiency	A nutritional condition produced by a deficiency of FOLIC ACID in the diet. Many plant and animal tissues contain folic acid, abundant in green leafy vegetables, yeast, liver, and mushrooms but destroyed by long-term cooking. Alcohol interferes with its intermediate metabolism and absorption. Folic acid deficiency may develop in long-term anticonvulsant therapy or with use of oral contraceptives. This deficiency causes anemia, macrocytic anemia, and megaloblastic anemia. It is indistinguishable from vitamin B 12 deficiency in peripheral blood and bone marrow findings, but the neurologic lesions seen in B 12 deficiency do not occur. (Merck Manual, 16th ed)	Deficiency, Folic Acid,Acid Deficiencies, Folic,Acid Deficiency, Folic,Deficiencies, Folic Acid,Folic Acid Deficiencies
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013936	Thymidine	A nucleoside in which THYMINE is linked to DEOXYRIBOSE.	2'-Deoxythymidine,Deoxythymidine,2' Deoxythymidine