A Radiosensitive Insect. Median Lethal Dose for Whole-body Irradiation with Cobalt 60 Gamma Rays ofLocusta migratoria migratorioides R. et F.

1967 ◽  
Vol 40 (477) ◽  
pp. 711-712 ◽  
Author(s):  
Shirley A. Austin
Keyword(s):  
Gamma Rays ◽  
Lethal Dose ◽  
Whole Body ◽  
Median Lethal Dose

scholarly journals Gene Expression in Parp1 Deficient Mice Exposed to a Median Lethal Dose of Gamma Rays

2018 ◽  
Vol 190 (1) ◽  
pp. 53 ◽  
Author(s):  
M. A. Suresh Kumar ◽  
Evagelia C. Laiakis ◽  
Shanaz A. Ghandhi ◽  
Shad R. Morton ◽  
Albert J. Fornace, Jr. ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gamma Rays ◽  
Lethal Dose ◽  
Median Lethal Dose ◽  
Deficient Mice

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

ROBUST ESTIMATION OF THE MEDIAN LETHAL DOSE

2002 ◽  
Vol 12 (2) ◽  
pp. 137-147 ◽  
Author(s):  
G. E. Kelly ◽  
J. K. Lindsey
Keyword(s):  
Robust Estimation ◽  
Lethal Dose ◽  
Median Lethal Dose

scholarly journals Sensitivity of The Stripe-Faced Dunnart, Sminthopsis Macroura (Gould 1845), To The Phenyl Pyrazole Insecticide, Fipronil, Toxicological Signs And Implications For Pesticide Risk Assessments In Australia

2021 ◽  
Author(s):  
Paul Story ◽  
Lyn A Hinds ◽  
Steve Henry ◽  
Andrew C. Warden ◽  
Greg Dojchinov
Keyword(s):  
Lethal Dose ◽  
Risk Assessments ◽  
Eutherian Mammal ◽  
Oral Toxicity ◽  
Median Lethal Dose ◽  
Agricultural Pesticides ◽  
Sminthopsis Macroura ◽  
The Difference ◽  
Ld50 Value ◽  
Female Responses

Abstract A lack of toxicity data quantifying responses of Australian native mammals to agricultural pesticides prompted an investigation into the sensitivity of the stripe-faced dunnart, Sminthopsis macroura (Gould 1845) to the insecticide, fipronil (5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulfinyl pyrazole, CAS No. 120068-37-3). Using the Up-And-Down method for determining acute oral toxicity in mammals, derived by the Organisation for Economic Cooperation and Development (OECD), median lethal dose estimates of 990 mg kg− 1 (95% confidence interval (CI) = 580.7–4770.0 mg kg− 1) and 270.4 mg kg− 1 (95% CI = 0.0 - >20000.0 mg kg− 1) were resolved for male and female S. macroura respectively. The difference between median lethal dose estimates for males and females may have been influenced by the increased age of two female dunnarts. Further modelling of female responses to fipronil doses used the following assumptions: (a) death at 2000 mg kg− 1, (b) survival at 500 mg kg− 1 and (c) a differential response (both survival and death) at 990 mg kg− 1. This modelling revealed median lethal dose estimates for female S. macroura of 669.1 mg kg− 1 (95% CI = 550–990 mg kg− 1; assuming death at 990 mg kg− 1) and 990 mg kg− 1 (95% CI = 544.7–1470 mg kg− 1; assuming survival at 990 mg kg− 1). These median lethal dose estimates are 3–10-fold higher than the only available LD50 value for a similarly sized eutherian mammal, Mus musculus (L. 1758; 94 mg kg− 1) and that available for Rattus norvegicus (Birkenhout 1769; 97 mg kg− 1). Implications for pesticide risk assessments in Australia are discussed.

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.

Tissue–air ratios for whole body irradiation with cobalt 60 gamma rays

1978 ◽  
Vol 51 (606) ◽  
pp. 460-462 ◽  
Author(s):  
E. Hochhäauser ◽  
O. A. Balk
Keyword(s):  
Gamma Rays ◽  
Whole Body

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.

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