SEARCH · PubMed Health
Results for “adenine supplementation”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The introduction of an adenine-supplemented anticoagulant preservative solution into u.s. blood services.
Explore the source record for details and available documents.
Observations on autologous, previously frozen, deglycerolized, agglomerated, resuspended red cells. I. Effect of storage temperatures. II. Effect of adenine supplementation of glycerolized red cells prior to freezing.
Explore the source record for details and available documents.
Growth and exopolysaccharide production by Lactobacillus helveticus ATCC 15807 in an adenine-supplemented chemically defined medium.
AIMS: To analyse the exopolysaccharide (EPS) production by Lactobacillus helveticus ATCC 15807 in a chemically defined medium (CDM) and the effect of nutrients and stress culture conditions on cell growth and EPS formation. METHODS AND RESULTS: Cultures were conducted in CDM: (i) containing essential and nonessential bases and vitamins; (ii) without nonessential bases and vitamins [Simplified CDM (SCDM)]; (iii) SCDM supplemented individually with vitamins and bases. The influence of carbohydrates, pH and osmotic culture conditions on growth and polymer formation was analysed. Adenine and lactose stimulated both growth and EPS production. Constant pH fermentations (4.5 and 6.2) did not improve EPS synthesis while NaCl and glycerol were detrimental for growth and polymer formation. In all media the EPS monomer composition was glucose and galactose (2.5 : 1). CONCLUSIONS: A SCDM containing adenine and lactose was optimal for cell growth and EPS formation by Lact. helveticus ATCC 15807. Controlled pH (6.2 and 4.5) and osmotic stress culture conditions did not improve polymer production. The EPS characteristics were identical in all media. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides a better knowledge on EPS synthesis by Lact. helveticus. A CDM to perform regulation studies on EPS production by Lact. helveticus species is now available.
Studies on citrate-phosphate-dextrose (CPD) blood supplemented with adenine.
The effect of varying adenine concentrations in citrate-phosphate-dextrose (CPD) blood was studied in an attempt to optimize the storage conditions for human erythrocytes with regard to posttransfusion viability and oxygen release function. The maintenance of diphosphoglycerate (DPG) was impaired by adenine supplementation; this effect was closely related to the adenine concentration. A 0.25 mM adenine concentration in CPD blood improved the adenosine triphosphate (ATP) levels and the posttransfusion viability markedly, without appreciably impairing the DPG maintenance. The results suggest that CPD solution supplemented with adenine to give a 0.25 mM concentration in the blood is a better preservative for human erythrocytes than the commonly used acid-citrate-dextrose (ACD), CPD, and ACD-adenine solutions with regard to posttransfusion viability and oxygen release function. Adenine addition to this low concentration is not expected to cause renal damage even after massive transfusion.
Dihydroxyacetone decreases the dATP pool, inducing replication stress and genomic instability in BEAS-2B cells.
Dihydroxyacetone (DHA), found in sunless tanning products and electronic cigarette aerosol, induces cytotoxic and genotoxic effects in cells. Studies across skin and systemic models demonstrated that DHA induces cell cycle arrest and mitochondrial stress, but its impact on replication is unknown. We investigated DHA exposure effects on lung epithelial BEAS-2B cells to determine if it induces replication stress and genomic instability. Acute DHA exposure generated oxidative stress, triggering 53BP1 foci formation 24 and 48 h after exposure. Evaluation of DNA damage response showed increased levels of pChk2 and pP53, demonstrating activation of double-strand break response. Using a DNA fiber assay, we observed decreased replication fork progression, which coincided with increased micronuclei formation. Removal of DHA from cell media partially alleviated the replication stress, similar to the removal of hydroxyurea, suggesting a reversible effect. Given DHA's incorporation into glycolytic pathways and induction of mitochondrial stress, we examined its effects on nucleotide biosynthesis and pool composition. DHA exposure reduced ribonucleotide reductase (RRM1/2) expression and specifically depleted dATP pools after 48 h. We confirmed that dATP depletion drives replication stress by supplementing cells with adenine during DHA exposure, which decreased DNA lesions, reduced damage signaling, and restored replication. Adenine supplementation also partially rescued DHA-induced cytotoxicity and micronuclei formation. These data demonstrate that DHA-induced DNA damage and dATP pool depletion cause replication stress in BEAS-2B cells, providing new information on DHA's genotoxic mechanism. The inability of adenine to completely rescue micronuclei formation also suggests additional mechanisms of action that impact mitosis, requiring further investigation.
Planning for innovation in health care: a breakthrough in blood banking.
A solution for preserving red blood cells (adenine) will make it possible to extend the life of blood from 21 to 35 days. Adenine supplementation may bring dramatic changes in blood outdating and the supply of blood to hospital blood banks. Substantial improvements, however, can be realized only if blood administrators are able to estimate the potential effects of adenine supplementation and set goals based on these projections. Appropriate action could then be taken to reduce blood collection and increase the supply of blood to hospitals. This paper offers a method for blood administrators to estimate the full effects of adenine supplementation and set reasonably attainable goals. Experiences with setting goals for a mid-western U.S. blood region are then discussed.
Mechanism for fatty liver induction in rats fed arginine deficient diets.
Arginine deficiency is known to lead to marked alterations in pyrimidine biosynthesis and the excessive loss of urinary orotic acid. Orotic acid feeding is known to lead to hepatic steatosis. These studies show that arginine deficiency also results in a marked increase in liver lipids in the rat. The majority of the increased liver lipid can be accounted for by triglyceride accumulation. Increased liver lipid infiltration was found to be independent of the sex of the rat. Accompanying this increase was a decrease in serum triglycerides and cholesterol concentrations. Fatty infiltrations induced by arginine deficiency could be reversed by refeeding an arginine enriched diet. Adenine supplementation (0.30%) to the arginine deficient diet also completely prevented the induction of fatty livers. Adenine supplementation resulted in a dramatic increase in urinary orotic acid excretion in the arginine deficient rat. Guanine supplementation (0.5%) to an arginine deficient diet reduced but did not prevent the induction of fatty livers. The similarities of fatty livers induced by arginine deficiency and orotic acid feeding are discussed.
Purine metabolism of erythrocytes preserved in adenine, adenine-inosine, and adenine-guanosine supplemented media.
Four different media for erythrocyte preservation have been compared by studying 16 variables mainly describing the purine metabolism and glycolysis of the erythrocyte. The concentrations of the additives in the erythrocyte suspensions were as follows: adenine, 0.25 mmol/l; adenine, 0.75 mmol/l; adenine, 0.25 and inosine, 0.50 mmol/l; and adenine, 0.25 and guanosine, 0.50 mmol/l. Evaluated from the concentrations of glycerate 2,3-bisphosphate and purine nucleoside triphosphates, the medium with adenine-guanosine was superior to the others. In this medium with adenine-guanosine was superior to the others. In this medium the guanosine was rapidly split to guanine, which was slowly used for nucleotide synthesis or deaminated to xanthine. Differences between ATP and GTP in their reactivity with the two enzymes phosphofructose kinase seems to explain the beneficial effect of guanosine on preservation of erythrocytes.
X-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of Neurospora crassa. XII. Analysis of multiple-locus ad-3 mutations reveals a nonrandom distribution of the separate sites of recessive lethal damage throughout the genome.
Previous studies on X-ray-induced adenine-3 mutations induced in heterokaryon 12 of Neurospora crassa showed that they consisted of gene/point mutations, multilocus deletion mutations, and 3 different genotypic classes of multiple-locus mutations (designated [-3]IR + RLCL, ad-3R + RLCL, and ad-3R + RL). In the present paper, multiple-locus mutations consisting of gene/point mutations at the ad-3A or the ad-3B locus with sites of recessive lethal damage closely linked to the ad-3 region (designated ad-3R + RLCL) or with sites of recessive lethal damage elsewhere in the genome (designated ad-3R + RL) were analyzed to determine whether they resulted from mutations at the same sites or different sites throughout the genome. It was assumed that if the recessive lethal mutations in individual multiple-locus mutations showed complementation on adenine-supplemented medium, they resulted from mutations at different sites. Multiple-locus mutations from both major genotypic classes were combined, as forced heterokaryons, in all possible pairwise combinations and then were plated out on adenine-supplemented medium. These studies indicated that 89.3% (50/56) of the recessive lethal mutations in these 2 classes of multiple-locus mutations complement one another. Thus, they are presumed to have resulted predominantly from genetic damage at different sites throughout the genome. Within the group of 20 multiple-locus mutations that did not complement in various pairwise combinations, 90% (18/20) appear to map in a region, distal to the ad-3 region, defined by a series of overlapping multilocus deletion mutations in 6 mutations of genotype ad-3R + RLCL. The other 10% (2/20) are located elsewhere on Linkage Group I or elsewhere in the genome. The present data base on multiple-locus mutations is unique; such events either can not be detected, or can only be detected with difficulty, in other eukaryotic specific-locus assay systems such as mammalian cells in culture, Drosophila or mice. Our data on X-ray-induced ad-3 specific-locus mutations from the present and previous studies demonstrate the presence of additional sites of genetic damage, both closely linked with the ad-3 region or elsewhere in the genome, in ad-3 specific-locus mutations. Because the frequencies of each class of multiple-locus mutations is dose-dependent, they must be taken into account in genetic risk assessment exercises. Failure to acknowledge the presence of such additional sites of genetic damage in the utilization of specific-locus data could result in underestimation of the risk of human exposure to environmental mutagens.
Infusion of physiological saline supplemented with adenine, pyruvate and phosphate.
After controlled bleeding 20 ml/kg enriched infusion fluid containing 0.005 mol/1 adenine, 0.1 mol/1 pyruvate, 0.1 mol/1dibasic sodium phosphate and 0.15 mol/1 sodium chloride was given to 14 dogs. Three dogs received after bleeding the same infusion fluid without adenine. One dog received only dextran after blood withdrawal and served as control Before and after bleeding and 1, 4, 24, 48 and 72 hours after infusion the levels of 2,3-DPG, ATP and P50 index were determined. After infusion of enriched fluid with and without adenine the level of 2,3-DPG and the value of P50 index increased. No rise in the ATP level was observed.
Response of the wild type and low xanthine dehydrogenase strains of Drosophila melanogaster to adenine resistance selection.
Survival rates of two Drosophila melanogaster strains, the Oregon R Wild Type (WT), and a mutant that was Low Xanthine Dehydrogenase (LXD), grown for six generations in control and in adenine-supplemented media, were determined. Although adenine was toxic to both strains, it was less toxic to the LXD strain. Uric acid levels indicated that WT Drosophila melanogaster was less able to metabolize adenine through the detoxification pathway. Male flies of both strains appeared to be more susceptible to adenine toxicity than were female. The results demonstrate that the adenine resistant strain may possess an enzyme pattern to minimize the toxic effect of adenine.
Control of the expression of the ADE2 gene of the yeast Saccharomyces cerevisiae.
The ADE2 gene encodes AIR-carboxylase which catalyzes the sixth step of the purine biosynthetic pathway in Saccharomyces cerevisiae. We have analyzed the effect of deletions in the promoter region of this gene on the expression of the enzyme using a fusion of the ADE2 gene promoter to the bacterial lacZ gene. Adenine added to the growth medium repressed the expression of the fusion at the level of mRNA. The ADE2-lacZ fusion expression can be slightly activated in response to amino-acid starvation, but only in Gcn4+ strains and in an adenine-supplemented medium. In the absence of adenine in the medium ADE2 gene expression is derepressed, and neither starvation for histidine nor a gcd1 general control regulatory mutation leads to additional derepression. Our experiments indicate that the ADE2 gene of the purine biosynthetic pathway is under both specific adenine control and the general amino-acid control system. The cis-acting promoter elements mediating both modes of regulation overlap each other and are located around the proximal TGACTC sequence.
Role of adenine in pathogenesis of Mycoplasma pneumoniae infections of tracheal epithelium.
Adenine sulfate and several related compounds were evaluated for their ability to retard the cytotoxic effect which normally accompanies M. pneumoniae infections of hamster tracheal explants. Adenine sulfate, at the 0.01 mM level, was found to exert a significant protective effect. Little or no ciliostasis or loss of cell viability was detectable when organ cultures were infected with 10(7) CFU of virulent M. pneumoniae in the presence of the adenine supplement. Mycoplasmas grew in broth and on plastic surfaces in the presence of adenine, and no significant diminution of growth rate or cell yield was detectable. Organisms adhered to the tracheal epithelial surface regardless of the presence or absence of adenine. When explants were incubated in the presence of 14C-(8)-adenine, rinsed, and then infected with M. pneumoniae, the adenine label could be recovered from the mycoplasmas 20 h after the infection. These data are compatible with the known nucleic acid requirement of mycoplasmas and with a model which ascribes a role for purine/pyrimidine competition and/or depletion in the infective process.
Purine requirement of cells cultured from humans affected with Lesch-Nyhan syndrome (hypoxanthine-guanine phosphoribosyltransferase deficiency).
Humans with the Lesch-Nyhan syndrome have an X-chromosomal mutant gene that causes severe neurological and developmental abnormalities. The patients are deficient in hypoxanthine-guanine phosphoribosyltransferase, which converts hypoxanthine to inosinic acid, a major precursor of adenine and guanine nucleotides. Paradoxically, the enzyme defect causes hypernormal de novo synthesis of inosinic acid, which manifests itself as excesses of hypoxanthine, xanthine, and uric acid. The first step in the de novo pathway is thought to be rate-limiting, due to feedback repression by adenine and guanine nucleotides. The derepressed rate of purine production in mutants and their failure to thrive could result from reduction in the amounts of nucleotides derived from inosinic acid to levels that are inadequate for normal feedback control and for nucleic acid synthesis needed in growth. Studies with cultured cells, reported here, support the interpretation that mutants are, in effect, nucleotide-deficient. Skin fibroblasts from patients fail to proliferate in media that do not contain supplementary adenine or folic acid, a participant in two stages of purine biosynthesis. The folic acid requirement of mutant cells is at least 50-fold greater than that of normal cells, which can synthesize all the nucleotides needed for growth without exogenous adenine. Both folic acid and adenine supplements are thought to provide mutant cells with the means of making more inosinic acid available for conversion to adenine and guanine nucleotides. It is not clear why the availability of inosinate or its conversion to other nucleotides is impaired. Therapy with adenine or folic acid begun at the time of birth may avert development of the disease in mutant males.The relevant gene is X-linked and shows clonal, single-allele-expression: phenotypically normal and phenotypically mutant clones have been derived from females heterozygous for the mutant gene. The phenotypically mutant heterozygous clones have the same requirement for adenine or folic acid as cells from hemizygous mutant males, an indication that the normal allele is repressed in these clones. The adenine-folic acid requirement of mutant cells provides a method of direct, clonal selection for rare, phenotypically normal cells in mutant populations, which is applicable to the single-active-X problem and other in vitro genetic studies.
Mitogen response of lymphocytes in platelet concentrates. Effect of storage and adenine.
The mitogen responsiveness of lymphocytes obtained from platelet concentrates under standard platelet storage conditions was measured. Blastogenic response to phytohemaglutinin, concanavalin A, and pokeweed mitogen declined significantly during storage to 19, 51, and 26 percent respectively of original activity. The presence of adenine supplementation in the anticoagulant preservative solution did not significantly effect the mitogen responses.
Growth of Bacillus coagulans in chemically defined media.
A nutritional study was made of five strains of Bacillus coagulans obtained from various culture collections. These five strains were descendants of two original isolates; three had been derived from one parent culture in years past and the other two were transfers from another parent culture. Therefore, the five cultures should have represented two distinct groups of genetically identical cultures. Three of the strains obtained from one culture collection had become methyl red-negative and sorbitol-negative and had gained abilities to hydrolyze gelatin and ferment arabinose. Nutritional requirements of the five cultures, determined at 37, 45, and 55 C, differed considerably among strains; however, thiamine and biotin were required by all cultures at all temperatures. Aspartic acid was stimulatory at 37 C and was required at 45 C; folic acid, basic amino acids, and certain other nutrilites were required at 55 C. Adenine supplementation was necessary for two strains at 55 C to prevent autolysis; this phenomenon is discussed. The response of these organisms to both serine and the basic amino acids at the three growth temperatures seems especially significant. The media devised for the growth of the five strains of B. coagulans used in this study permit excellent growth at three incubation temperatures.
Blood preservation 33. Phosphate enhancement of ribose maintenance of 2,3-DPG and ATP.
Blood storage in CPD-adenine supplemented with 25 mM inosine and 10 mM phosphate gave 2,3-DPG levels as high as 140 per cent of normal for six weeks of blood storage at 4 C. Lower but normal 2,3-DPG levels were maintained throughout six weeks with inosine or inosine plus ribose. Ribose alone provided marginally increased DPG maintenance over the control, but ribose with phosphate maintained 2,3-DPG levels above 70 per cent of normal for five weeks of storage and two weeks longer than the control preservative. ATP levels were maintained at normal or above for six weeks with phosphate plus ribose or inosine. 2,3-DPG maintenance has previously been shown to be impaired by phosphate, unless inosine is also present. The ribose and inosine effects on 2,3-DPG maintenance are not additive. Phosphate also has an enhancement effect on ATP maintenance in the presence of either ribose or inosine.