Methylation of Guanine in vivo by the Organophosphorus Insecticide Methamidophos*

1987 ◽  
Vol 42 (1-2) ◽  
pp. 17-20 ◽  
Author(s):  
Salah M . A . D . Zayed ◽  
Fathya M. Mahdi
Keyword(s):  
Nucleic Acids ◽  
Mouse Liver ◽  
Organophosphorus Insecticide ◽  
Appreciable Amount ◽  
Dna And Rna ◽  
Applied Dose

Abstract The methylating capability of methamidophos, assayed by the formation of [7-14C]methylguanine in mouse liver, was investigated using a 14C-insecticide labelled at the O -CH3 group. Following i.p. administration of the toxicant, [7-14C]methylguanine could be isolated from liver nucleic acids of treated mice. The amount of 14C-label reached its maximum 6 h follow ing administration of the insecticide. At maximum 14C-labelling, the amount of 7-methylguanine calculated as fraction of applied dose, was 20-22 × 10-4 and 98 -104 x-4, for DNA and RNA , respectively. The results obtained indicate also, that an appreciable amount of I4C-activity is incorporated via the C-1 pool.

The reaction of urethane with mouse liver nucleic acids in vivo

Pathology ◽  
1971 ◽  
Vol 3 (3) ◽  
pp. 223-225 ◽  
Author(s):  
T.A. Lawson ◽  
A.W. Pound
Keyword(s):  
Nucleic Acids ◽  
Mouse Liver

The Reaction of Urethane with Mouse Liver Nucleic Acids in Vivo

Pathology ◽  
1971 ◽  
Vol 3 (3) ◽  
pp. 223-225 ◽  
Author(s):  
T. A. Lawson ◽  
A. W. Pound
Keyword(s):  
Nucleic Acids ◽  
Mouse Liver

THE SYNTHESIS OF DNA AND RNA IN NORMAL HUMAN ENDOMETRIUM IN SHORT-TERM INCUBATION IN VITRO AND ITS RESPONSE TO OESTRADIOL AND PROGESTERONE

1970 ◽  
Vol 48 (1) ◽  
pp. 17-28 ◽  
Author(s):  
S. NORDQVIST
Keyword(s):  
Nucleic Acids ◽  
Dna Synthesis ◽  
Acid Synthesis ◽  
Short Term ◽  
Normal Endometrium ◽  
Dna And Rna ◽  
Progesterone Synthesis ◽  
Normal Human

SUMMARY A method is described for short-term incubations in vitro of normal endometrium for the study of nucleic acid synthesis. Tissue suspensions of specimens obtained at curettage were incubated with and without hormones in a medium consisting of Parker's 199 medium and 20% adult human serum; [3H]thymidine and [14C]uridine were added. The isotope uptake into the nucleic acids was determined and related to the total amount of DNA in each sample. Marked variation in DNA synthesis was noted in endometria obtained at different phases of the menstrual cycle. RNA synthesis varied less. After the addition of progesterone, synthesis of both nucleic acids was reduced. The magnitude of this response varied in different endometria. Thus DNA synthesis in endometria already under strong progesterone influence in vivo (midsecretory phase) was least affected when progesterone was added in vitro.

scholarly journals A world beyond double-helical nucleic acids: the structural diversity of tetra-stranded G-quadruplexes

ChemTexts ◽  
2021 ◽  
Vol 7 (4) ◽  
Author(s):  
Klaus Weisz
Keyword(s):  
Hydrogen Bond ◽  
Nucleic Acids ◽  
Genetic Information ◽  
Structural Diversity ◽  
Base Pairing ◽  
Rna Sequences ◽  
Dna And Rna ◽  
Regulatory Functions ◽  
Insight Into

AbstractNucleic acids can adopt various secondary structures including double-, triple-, and tetra-stranded helices that differ by the specific hydrogen bond mediated pairing pattern between their nucleobase constituents. Whereas double-helical DNA relies on Watson–Crick base pairing to play a prominent role in storing genetic information, G-quadruplexes are tetra-stranded structures that are formed by the association of guanine bases from G-rich DNA and RNA sequences. During the last few decades, G-quadruplexes have attracted considerable interest after the realization that they form and exert regulatory functions in vivo. In addition, quadruplex architectures have also been recognized as versatile and powerful tools in a growing number of technological applications. To appreciate the astonishing structural diversity of these tetra-stranded structures and to give some insight into basic interactions that govern their folding, this article gives an overview of quadruplex structures and rules associated with the formation of different topologies. A brief discussion will also focus on nonconventional quadruplexes as well as on general principles when targeting quadruplexes with ligands. Graphic abstract

scholarly journals RAGE is a nucleic acid receptor that promotes inflammatory responses to DNA

2013 ◽  
Vol 210 (11) ◽  
pp. 2447-2463 ◽  
Author(s):  
Cherilyn M. Sirois ◽  
Tengchuan Jin ◽  
Allison L. Miller ◽  
Damien Bertheloot ◽  
Hirotaka Nakamura ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Inflammatory Responses ◽  
Immune Recognition ◽  
Dna Uptake ◽  
Rna Molecules ◽  
Receptor Complexes ◽  
Dna And Rna ◽  
Signaling Receptors ◽  
Mammalian Immune System

Recognition of DNA and RNA molecules derived from pathogens or self-antigen is one way the mammalian immune system senses infection and tissue damage. Activation of immune signaling receptors by nucleic acids is controlled by limiting the access of DNA and RNA to intracellular receptors, but the mechanisms by which endosome-resident receptors encounter nucleic acids from the extracellular space are largely undefined. In this study, we show that the receptor for advanced glycation end-products (RAGE) promoted DNA uptake into endosomes and lowered the immune recognition threshold for the activation of Toll-like receptor 9, the principal DNA-recognizing transmembrane signaling receptor. Structural analysis of RAGE–DNA complexes indicated that DNA interacted with dimers of the outermost RAGE extracellular domains, and could induce formation of higher-order receptor complexes. Furthermore, mice deficient in RAGE were unable to mount a typical inflammatory response to DNA in the lung, indicating that RAGE is important for the detection of nucleic acids in vivo.

Exosome as a Natural Gene Delivery Vector for Cancer Treatment

2020 ◽  
Vol 20 (11) ◽  
pp. 821-830
Author(s):  
Prasad Pofali ◽  
Adrita Mondal ◽  
Vaishali Londhe
Keyword(s):  
Gene Therapy ◽  
Gene Delivery ◽  
Nucleic Acids ◽  
Cancer Treatment ◽  
Intestinal Barrier ◽  
Gene Carrier ◽  
Gene Delivery Vector ◽  
Delivery Vector

Background: Current gene therapy vectors such as viral, non-viral, and bacterial vectors, which are used for cancer treatment, but there are certain safety concerns and stability issues of these conventional vectors. Exosomes are the vesicles of size 40-100 nm secreted from multivesicular bodies into the extracellular environment by most of the cell types in-vivo and in-vitro. As a natural nanocarrier, exosomes are immunologically inert, biocompatible, and can cross biological barriers like the blood-brain barrier, intestinal barrier, and placental barrier. Objective: This review focusses on the role of exosome as a carrier to efficiently deliver a gene for cancer treatment and diagnosis. The methods for loading of nucleic acids onto the exosomes, advantages of exosomes as a smart intercellular shuttle for gene delivery and therapeutic applications as a gene delivery vector for siRNA, miRNA and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and also the limitations of exosomes as a gene carrier are all reviewed in this article. Methods: Mostly, electroporation and chemical transfection are used to prepare gene loaded exosomes. Results: Exosome-mediated delivery is highly promising and advantageous in comparison to the current delivery methods for systemic gene therapy. Targeted exosomes, loaded with therapeutic nucleic acids, can efficiently promote the reduction of tumor proliferation without any adverse effects. Conclusion: In the near future, exosomes can become an efficient gene carrier for delivery and a biomarker for the diagnosis and treatment of cancer.

scholarly journals Graphene Oxide: A Smart (Starting) Material for Natural Methylxanthines Adsorption and Detection

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4247 ◽  
Author(s):  
Rita Petrucci ◽  
Isabella Chiarotto ◽  
Leonardo Mattiello ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Nucleic Acids ◽  
Reduced Graphene Oxide ◽  
Electrochemical Sensors ◽  
Enzymatic Digestion ◽  
Biologically Active ◽  
Polar Solvents ◽  
Dna And Rna ◽  
Reduced Graphene

Natural methylxanthines, caffeine, theophylline and theobromine, are widespread biologically active alkaloids in human nutrition, found mainly in beverages (coffee, tea, cocoa, energy drinks, etc.). Their detection is thus of extreme importance, and many studies are devoted to this topic. During the last decade, graphene oxide (GO) and reduced graphene oxide (RGO) gained popularity as constituents of sensors (chemical, electrochemical and biosensors) for methylxanthines. The main advantages of GO and RGO with respect to graphene are the easiness and cheapness of synthesis, the notable higher solubility in polar solvents (water, among others), and the higher reactivity towards these targets (mainly due to – interactions); one of the main disadvantages is the lower electrical conductivity, especially when using them in electrochemical sensors. Nonetheless, their use in sensors is becoming more and more common, with the obtainment of very good results in terms of selectivity and sensitivity (up to 5.4 × 10−10 mol L−1 and 1.8 × 10−9 mol L−1 for caffeine and theophylline, respectively). Moreover, the ability of GO to protect DNA and RNA from enzymatic digestion renders it one of the best candidates for biosensors based on these nucleic acids. This is an up-to-date review of the use of GO and RGO in sensors.

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