scholarly journals Characteristic of the active substance of the Saccharomyces cerevisiae preparation having radioprotective properties

2020 ◽  
Vol 24 (6) ◽  
pp. 643-652
Author(s):  
G. S. Ritter ◽  
V. P. Nikolin ◽  
N. A. Popova ◽  
A. S. Proskurina ◽  
P. E. Kisaretova ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Lethal Dose ◽  
Radioprotective Effect ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Radioprotective Action ◽  
Blood Stem Cells ◽  
Time Parameters ◽  
Radioprotective Properties ◽  
Made In

The paper describes some biological features of the radioprotective effect of double-stranded RNA preparation. It was found that yeast RNA preparation has a prolonged radioprotective effect after irradiation by a lethal dose of 9.4 Gy. 100 % of animals survive on the 70th day of observation when irradiated 1 hour or 4 days after 7 mg RNA preparation injection, 60 % animals survive when irradiated on day 8 or 12. Time parameters of repair of double-stranded breaks induced by gamma rays were estimated. It was found that the injection of the RNA preparation at the time of maximum number of double-stranded breaks, 1 hour after irradiation, reduces the efficacy of radioprotective action compared with the injection 1 hour before irradiation and 4 hours after irradiation. A comparison of the radioprotective effect of the standard radioprotector B-190 and the RNA preparation was made in one experiment. It has been established that the total RNA preparation is more efficacious than B-190. Survival on the 40th day after irradiation was 78 % for the group of mice treated with the RNA preparation and 67 % for those treated with B-190. In the course of analytical studies of the total yeast RNA preparation, it was found that the preparation is a mixture of single-stranded and double-stranded RNA. It was shown that only double-stranded RNA has radioprotective properties. Injection of 160 μg double-stranded RNA protects 100 % of the experimental animals from an absolutely lethal dose of gamma radiation, 9.4 Gy. It was established that the radioprotective effect of double-stranded RNA does not depend on sequence, but depends on its double-stranded form and the presence of “open” ends of the molecule. It is supposed that the radioprotective effect of double-stranded RNA is associated with the participation of RNA molecules in the correct repair of radiation-damaged chromatin in blood stem cells. The hematopoietic pluripotent cells that have survived migrate to the periphery, reach the spleen and actively proliferate. The newly formed cell population restores the hematopoietic and immune systems, which determines the survival of lethally irradiated animals.

Lethal Dose (LD50) Fixation and Sensitivity of Fenugreek (Trigonellafoenum-graecumL.) to Gamma Radiation for Induction of Mutation

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
ANURADHA PATEL ◽  
POONAM VERMA ◽  
SHARDA CHOUDHARY ◽  
ARVIND KUMAR VERMA
Keyword(s):  
Genetic Variability ◽  
Gamma Rays ◽  
Growth Parameters ◽  
Seedling Survival ◽  
Lethal Dose ◽  
Germination Percentage ◽  
Mutation Breeding ◽  
Vigour Index ◽  
Small Flower ◽  
Dose Dependent

Fenugreek (Trigonella foenum-graecumL.) is an annual crop, mainly used as a spiceand leafy vegetable crop in many parts of the world. Classical breeding in fenugreek is restricted due to its low genetic variability and small flower size which hamper manual emasculation and pollination. Mutation breeding is an effective way to enrich genetic variability in crop plants. An experiment was conducted to determine the lethal dose of the physical mutagen gamma rays in fenugreek. The dry seeds of fenugreek were exposed to different doses of gamma rays i.e. 150Gy, 200Gy, 250Gy, 300Gy and 350Gy. These irradiated seeds were sown in the Petri plates with non-irradiated seeds (control). As the dose of gamma rays increased, there was a decrease in germination percentage, seedling survival, root length, shoot length and vigour index. Among five doses of gamma rays, the maximum seed germination was observed at lowest dose 150Gy (93%), followed by 200Gy (83%), 250Gy (76%), 300Gy (76%) and 350Gy (64%). The seedling survival was decreased from 90% (in control) to 56% in 350Gy dose of gamma rays. The gamma rays dose of 150Gy gave stimulatory effect on seedlings growth. The growth parameters were dose dependent, as the dose of gamma rays increased from 200Gy to 350Gy. The gamma rays dose of 350Gy showed 64% seeds germination and 56% of seedlings survival. Therefore, it is concluded that the LD50 dose for fenugreek is close to 350Gy. This information would be highly useful for initiating mutation breeding programme in fenugreek

scholarly journals Induction of Promoter DNA Methylation Upon High-Pressure Spraying of Double-Stranded RNA in Plants

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 789
Author(s):  
Athanasios Dalakouras ◽  
Ioannis Ganopoulos
Keyword(s):  
High Pressure ◽  
De Novo ◽  
Epigenetic Changes ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Promoter Sequences ◽  
Promoter Dna Methylation ◽  
Promoter Dna ◽  
First Time ◽  
De Novo Methylation

Exogenous application of RNA molecules is a potent method to trigger RNA interference (RNAi) in plants in a transgene-free manner. So far, all exogenous RNAi (exo-RNAi) applications have aimed to trigger mRNA degradation of a given target. However, the issue of concomitant epigenetic changes was never addressed. Here, we report for the first time that high-pressure spraying of dsRNAs can trigger de novo methylation of promoter sequences in plants.

RNA polymerase activity in virions from Ustilago maydis

1984 ◽  
Vol 4 (1) ◽  
pp. 188-194
Author(s):  
B S Ben-Tzvi ◽  
Y Koltin ◽  
M Mevarech ◽  
A Tamarkin
Keyword(s):  
Rna Polymerase ◽  
Viral Genome ◽  
Ustilago Maydis ◽  
Polymerase Activity ◽  
Reaction Products ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Rna Transcripts ◽  
Rna Polymerase Activity

RNA polymerase activity is associated with the double-stranded RNA virions of Ustilago maydis. The reaction products of the polymerase activity are single-stranded RNA molecules. The RNA molecules synthesized are homologous to the three classes of double-stranded RNA molecules that typify the viral genome. The single-stranded RNA synthesized is released from the virions. The molecular weight of the single-stranded RNA transcripts is about half the size of the double-stranded RNA segments, and thus, it appears that in the in vitro reaction, full-length transcripts can be obtained.

scholarly journals Identification of duration construction of combined foundation

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Iakov Pronozin ◽  
Denis Volosiuk
Keyword(s):  
Labor Costs ◽  
Work Time ◽  
Common Time ◽  
Actual Duration ◽  
Concrete Mix ◽  
Time Standards ◽  
Time Parameters ◽  
Working Out ◽  
Sufficient Precision ◽  
Made In

The method for determining the duration of a combined foundation device, which is constructed in several stages, is considered in the article. The main stages include the construction of structures and the regulation of the stress-strain state of the soil base, which is carried out by pressing it. Pressurization is carried out during the construction of the building. On an example of construction of the linear schedule the mutual coordination of works of each stage during building of a building is resulted. The possibility of varying the time parameters of the network model is presented depending on the parameters of the crimping process. Between the late and early beginnings of work there is a common time reserve, which is part of the technological break. The authors present empirical data on the actual duration of concreting of grillage of combined foundations. The study of time parameters of technological processes was based on such methods of observation as timekeeping, photo-timing and video and photo-fixation. The measurements were carried out during the construction of the residential complex «Neighbors» in Tyumen. The scope of research included the study of labor costs of the team, consisting of seven concrete workers. The investigated technological process of concreting consistently included the reception and direction of the concrete mix, laying, leveling and compacting the mixture, smoothing and smoothing the grillage surface. Based on the data obtained, the dependencies of the average duration of concrete work on the volume of the concrete mix laid in the cells (shells) are revealed. The comparison of work durations on both foundations is made. Actual work is determined and work time standards are established, allowing to organize concrete works with sufficient precision when drawing up calendar plans within the framework of working out of projects for the production of works. This article is made in the framework of the dissertation research by co-author Volosiuk D.V.

scholarly journals Ribozymes of the hepatitis delta virus: recent findings on their structure, mechanism of catalysis and possible applications.

2001 ◽  
Vol 48 (2) ◽  
pp. 409-418 ◽  
Author(s):  
J Ciesiolka ◽  
J Wrzesinski ◽  
M Legiewicz ◽  
B Smólska ◽  
M Dutkiewicz
Keyword(s):  
Hepatitis Delta Virus ◽  
Catalytic Properties ◽  
Rna Degradation ◽  
Base Catalysis ◽  
Rna Catalysis ◽  
X Ray ◽  
Rna Molecules ◽  
Mechanism Of Catalysis ◽  
Made In ◽  
Delta Virus

Although the delta ribozymes have been studied for more than ten years the most important information concerning their structure and mechanism of catalysis were only obtained very recently. The crystal structure of the genomic delta ribozyme turns out to be an excellent example of the extraordinary properties of RNA molecules to fold into uniquely compact structures. Details of the X-ray structure have greatly stimulated further studies on the folding of the ribozymes into functionally active molecules as well as on the mechanism of RNA catalysis. The ability of the delta ribozymes to carry out general acid-base catalysis by nucleotide side chains has been assumed in two proposed mechanisms of self-cleavage. Recently, considerable progress has been also made in characterizing the catalytic properties of trans-acting ribozyme variants that are potentially attractive tools in the strategy of directed RNA degradation.

scholarly journals Physical and Chemical Induced Mutagenesis Study for Identifying Lethality Dose in Chick Pea (Cicer arietinum L.) Var. Co - 4

2015 ◽  
Vol 35 ◽  
pp. 1-5 ◽  
Author(s):  
S. Umavathi ◽  
L. Mullainathan
Keyword(s):  
Seed Germination ◽  
Gamma Rays ◽  
Root Length ◽  
Lethal Dose ◽  
Seedling Height ◽  
Growth Reduction ◽  
Chick Pea ◽  
Induced Mutagenesis ◽  
Mutagenesis Study ◽  
Physical And Chemical

The present study was conducted in order to determine the effect of gamma rays and EMS on seed germination, Seedling height and root length in chick pea to identify the lethal dose (LD50). In this regard, the healthy seeds of chick pea was subjected to different doses/concentrations of gamma rays (20, 30, 40, 50 and 60kR) and EMS (10, 20, 30, 40 and 50mM) for inducing mutation. The effect of gamma rays and EMS was determined by measuring the seed germination, seedling height and root length under the conditions of the M1 generation. The results shows that, the seed germination, seedling height and root length were significantly decreased with increasing doses/concentrations. The LD50 values were observed based on the growth reduction of seedlings after treatments with mutagen. The effective doses/concentrations which caused 50% growth reduction were observed in 40kR in gamma rays and 30mM in EMS.

scholarly journals On a method of increasing the sensitiveness of animal tumours to X-rays

1935 ◽  
Vol 118 (809) ◽  
pp. 316-320 ◽  
Keyword(s):  
Gamma Rays ◽  
Small Area ◽  
Lethal Dose ◽  
Deterrent Effect ◽  
Surrounding Tissue ◽  
Complete Disappearance ◽  
X Rays ◽  
Tumour Implantation ◽  
Actual Size ◽  
Spontaneous Absorption

Any means of increasing the sensitiveness of human tumours to X-rays or gamma rays would certainly change the outlook on the treatment of cancer in many sites, more especially for the types of tumours which are sometimes termed radio-resistant. The experiments recorded here were mainly carried out with a fairly rapidly growing sarcoma of the rat (F. 16), originally given us by the Imperial Cancer Research Fund in 1921. We (1933) have already referred to the modification which it has since undergone, particularly to the extraordinary increase in its rate of growth and cellularity of structure. These changes are probably due to the technique used in its transplantation, and to the use of a strain of rats particularly sensitive to tumour implantation. With Jensen’s rat sarcoma, 100% of progressive tumours is generally obtained from grafts and 90% is looked upon as a rather poor result. Another obvious advantage for experiments of the type described here is that spontaneous absorption of an established tumour of either F. 16 or J. R. S. is extremely rare. In the first experiments established tumours were exposed for varying lengths of time to carefully measured doses of X-rays generated at about 170 kV and filtered by 10 mm of aluminium. The minimum amount of radiation necessary to cause the disappearance of all tumours of each type is referred to here as the “lethal” dose. It is expressed by time—for sarcoma F. 16 it is 200 minutes, approximately equivalent to 1000 r. A dose of X-rays amounting to 30-40% of the lethal dose generally has some deterrent effect on the growth of the tumour; 40% of the lethal dose very rarely causes the disappearance of a well-established tumour. The effect becomes more definite and lasts longer as the dose is increased and the majority of tumours disappear after a dose which is 75% of the lethal dose. Great care has always been taken to expose only the tumour, as it has been observed that the dose of X-rays required to cause complete disappearance is considerably less when even a small area of surrounding tissue is irradiated. The actual size of the tumour at the time of irradiation also influences the final result; quite small, young tumours may disappear with a comparatively small dose of X-rays, while very large ones are sometimes little affected by a much larger dose, in spite of strict attention to the principle of dosage which is measured by the ionization at the lowest level of the tumour. Most of the tumours used for these experiments were between 16 mm and 22 mm in diameter at the time of exposure to X-rays.

scholarly journals Plasmid-Based shRNA Lentiviral Particle Production for RNAi Applications

2014 ◽  
Vol 19 (9) ◽  
pp. 1309-1313 ◽  
Author(s):  
David Shum ◽  
Hakim Djaballah
Keyword(s):  
Particle Production ◽  
High Titer ◽  
Cell Types ◽  
Host Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hairpin Rna ◽  
Double Stranded Rna ◽  
Rna Molecules ◽  
Overall Efficiency

Lentiviral vectors have become mainstream gene transfer vehicles for their ability to deliver and integrate into host cells. In RNA interference (RNAi) applications, lentiviral constructs constitutively express double-stranded RNA molecules, usually as short hairpin RNA (shRNA), enabling long-term gene silencing, and, when pseudotyped with a broad host glycoprotein envelope, allow a multitude of cell types to be transduced. Their successful use ultimately relies on the production of lentiviral particles in high titer and uniformity. Typical methods require the transfection of three or more plasmids in which essential viral elements have been encoded separated so as to remain replication deficient. These transfection procedures are of critical importance; however, methods often vary among laboratories, making it difficult to assess the overall efficiency of lentiviral particle production. In this report, we focus exclusively on this step and compare the overall impact of the commercial transfection reagent FuGENE 6 with FuGENE HD. We found that FuGENE HD resulted in at least 5-fold improvement in viral particle titer as assessed by the p24 standard enzyme-linked immunosorbent assay. We present the complete optimized workflow and demonstrate this utility in which a single modification of this transfection step improved the lentiviral particle production.

INVESTIGATION OF THE RADIOPROTECTIVE EFFECT OF ORTHOVANADATE IN MICE AFTER TOTAL BODY IRRADIATION

2019 ◽  
Vol 186 (2-3) ◽  
pp. 149-154
Author(s):  
Zuzana Šinkorová ◽  
Alžběta Filipová ◽  
Jiřina Vávrová ◽  
Jaroslav Pejchal ◽  
Lenka Andrejsová ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Large Scale ◽  
Lethal Dose ◽  
Response Prediction ◽  
Increasing Risk ◽  
Pre Treatment ◽  
High Doses ◽  
Total Body ◽  
Lymphocyte Populations

Abstract The increasing risk of acute large-scale exposure of ionising irradiation on the population underlines the necessity of developing effective radioprotective and mitigating agents. The aim of this work was to investigate the effect of sodium orthovanadate pre-treatment on mice exposed to high doses of gamma rays (from 5 to 13 Gy). The determination of median lethal dose within 30 days confirmed that orthovanadate applied to total-body-irradiated mice intra-peritoneally has a radioprotective but not a mitigating effect. With orthovanadate pre-treatment, the composition of cellularity in the bone marrow improved substantially and the main lymphocyte populations restored during the first month after irradiation. These findings contribute to ‘gap-filling’ in radioprotective effects and demonstrate the importance of haematological parameters in radiation–response prediction.

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