Action des rayons gamma du Cobalt 60 sur la teneur en acides nucléiques et l'histogenèse des tissus de tubercule de topinambour cultivés in vitro

1983 ◽  
Vol 61 (5) ◽  
pp. 1448-1455 ◽  
Author(s):  
Janine Schaeverbeke-Sacré ◽  
Béatrice Matheron

DNA and RNA contents are studied in Jerusalem artichoke tuber explants cultured in vitro after gamma irradiation (0–5 × 105 rads (1 rad = 10 mGy)). The lower part of the explants is stimulated as soon as in contact with the medium. This stimulated area is still able to synthesize DNA and RNA up to 104 rads. An histological and cytological study shows that tissue neoformations can be observed up to 6000 rads in this outer area and that gamma rays seem to keep the cells in a "premitotic" state for a longer or shorter period according to the applied radiation dose.

1982 ◽  
Vol 60 (11) ◽  
pp. 2215-2218
Author(s):  
Janine Schaeverbeke-Sacré ◽  
Béatrice Matheron

Carbohydrate and nitrogen budgets were studied in Jerusalem artichoke tuber explants cultured in vitro after gamma irradiation (0 to 106 rads (1 rad = 10−2 J/kg)). A certain level of reducing sugars is reached and retained in all the explants and, in all cases, an increase of protein nitrogen is observed. The highly irradiated tissues have a very disturbed metabolism that involves in particular, amino acid leaching into the culture medium.


1978 ◽  
Vol 56 (3) ◽  
pp. 167-173
Author(s):  
Joachim Sparkuhl ◽  
George Setterfield

Both nongrowing (water-incubated) and growing (hormonally stimulated) Jerusalem artichoke tuber cells contain membrane-bound (mb) ribosomes. Using a rapid flotation procedure, a membrane fraction was prepared from both types of cells. This fraction was enriched in mb ribosomes, contained NADH cytochrome c reductase activity, had RNA:phospholipid and RNA:protein ratios similar to those reported for rough microsomes from animal tissues, and supported synthesis of preinitiated proteins in vitro. Using puromycin and detergent release, vectorial transport of labelled polypeptides was measured in the in vitro system. Of proteins made by mb ribosomes from nongrowing cells, only 12% remained associated with microsome membranes following chain termination. The comparable figure for proteins from mb ribosomes of growing tissue was 42%. The membrane-associated proteins were preferentially protected from protease digestion. Some possible reasons are suggested for the correlation between cell growth and the association of newly synthesized proteins with microsomes. The role of proteins synthesized by mb ribosomes but not vectorially transported, in both growing and nongrowing cells, is unknown.


In a previous paper (1) the effects of the gamma rays of radium upon the number of cells in mitosis in tissue cultures has been described, the cultures being examined 80 minutes after irradiation. Under the conditions of the experiment it was shown that there was a threshold of intensity below which no diminution in the number of cells in mitosis was apparent, and also a threshold of time for each intensity which must be exceeded before diminution could be observed. Gilman and Baetjer (2) showed that there was an acceleration in the development of the eggs of Amblystoma after irradiation by X-rays. Hastings, Beckton and Wedd (4) showed an increase in the rate of hatching out of silk-worm eggs which had been irradiated by X-rays; and Lazarus-Barlow and Beckton (3) showed that small intensities of beta-rays acting for a long period were followed by a greater rate of cell division in the eggs of Ascaris Megalocephala . In the case of tissue cultures Canti and Donaldson (5) described an experiment in which cessation of mitosis having been caused by exposure to the gamma rays of radium a return of mitosis was observed after removal of the radium. Since the completion of the present experiments it has been shown by Spear (6) that by lowering the temperature of tissue cultures to 0° C. for 4 hours and subsequently incubating for various periods there is a fall in the number of cells in mitosis followed by a return in increased numbers which is compensatory.


1978 ◽  
Vol 52 (4) ◽  
pp. 283-286 ◽  
Author(s):  
Md. Zafrullah Ansari ◽  
Kunwar Suresh Singh

ABSTRACTIrradiation of the infective larvae ofGaigeria pachyscelisRailliet and Henry, 1910 with gamma rays upto 160 Kr had no significant effect on thein vitrosurvival of these larvae for a period of 49 days, maintained either at room temperature (32.2–39.4°C) or at 4°C. However, the behaviour of the irradiated larvae in the lamb host was much changed, as shown by a marked reduction in the worm establishment and the development of stunted and sterile worms from these larvae. As the level of irradiation increased, there was a corresponding decrease in the subsequent worm establishment. It was found that male larvae are more sensitive to the effects of irradiation than female ones, particularly at higher levels.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2535 ◽  
Author(s):  
Maria Casimiro ◽  
Susana Gomes ◽  
Gabriela Rodrigues ◽  
João Leal ◽  
Luís Ferreira

Several studies have shown that chitosan possesses characteristics favorable for promoting dermal regeneration and accelerated wound healing. In this work we have reported the work that has been done on the development and characterization of biocompatible and biodegradable chitosan based matrices to be used as skin scaffolds. Poly(vinylpyrrrolidone) (PVP) was used as copolymer and a two steps methodology of freeze-drying and gamma irradiation was used to obtain the porous matrices. The influence of PVP content, synthesis procedure and absorbed radiation dose on matrices’ physical, chemical and structural properties was evaluated by ATR-FTIR, TGA, SEM, contact angle measurements and degradation behavior. The in vitro cellular viability and proliferation of HFFF2 fibroblast cell line was analyzed as a measure of matrices’ biocompatibility and ability to assist skin regeneration. Results show that over the studied range values, gamma-radiation dose, copolymer concentration and synthesis procedure can be used to tailor the matrices’ morphology in terms of porosity and surface roughness. Early results from biological assays evidence the biocompatibility of the prepared chitosan/PVP matrices since cells adhered to the surface of all matrices (chitosan/PVP (5%) γ-irradiated at 10 kGy presents the higher cellular viability). These features show that the resultant matrices could be a potential suitable scaffold for skin tissue regeneration.


2016 ◽  
Vol 10 (3) ◽  
pp. 355
Author(s):  
Yuyu S Poerba ◽  
MARIA IMELDA ◽  
AIDA WULANSARI ◽  
DIYAH MARTANTI

Amorphophallus muelleri Blume (Araceae) is valued for its glucoman content for use infood industry (heathy diet food), paper industry, pharmacy and cosmetics. The cultivationof A. muelleri is hampered by limited genetic quality of seed. The species is triploid(2n=3x=39), the seed is developed apomictically, and pollen production is low. Thespecies is only propagated vegetatively. This may explain that the species is difficultto breed conventionally and genetic variability in the existing landraces cultivars israther limited. Conservation of this species, therefore, is important for availability of thespecies in the future use of this plant. The objective of present research is to increasegenetic variation by induce mutation using gamma-rays irradiation of shoot culturesof A. muelleri and to identify DNA polymorphism induced by gamma irradiation usingrandom amplified polymorphic DNA (RAPD), so the mutants produced can be used forbreeding purposes and for conservation program. Results of the experiment showedthat gamma irradiation less than 5 gray was effective to induce mutation of A. muelleri.Four RAPD primers generated 35 scorable bands with 100% polymorphic bands. Sizeof the bands varied from 350bp to 2.0kbp. Clustering analysis was performed based onRAPD profiles using the UPGMA method. The range of genetic distance among individualgenotypes was from from 0.00 to 0.72, while genetic variance of the population was0.21 + 0.13. The eighteen genotypes were proof to be mutants. The mutants producedin this experiment could be used as new germplasms for breeding purposes as well asfor use in conservation strategy


2012 ◽  
Vol 7 (2) ◽  
Author(s):  
Ni Nyoman Sri Putu Verawati

Abstrak: Pengaruh radiasi sinar gamma terhadap sifat optik dari poli vinil alkohol (PVA) yang dicampur dengan trichloro acetid acid (TCA) dan pewarna methilen blue (MB) dapat digunakan pada dosimetri dan pengukuran dosis radiasi sinar gamma telah dipelajari dengan menggunakan metode spektrofotometer. dosimeter telah diradiasi sampai dosis 14 kGy dengan menggunakan sinar gamma 60Co. Polimer  film mengalami perubahan warna dari biru keunguan ke kuning akibat radiasi sinar gamma. Perubahan warna ini mengindikasikan terbentuknya asam kuat, dengan kenaikan dosis radiasi banyak ion klorin putus dari rantai karbon TCA dan akibat radiasi menyebabkan ion H+ dan OH- menjadi radikal bebas yang dihasilkan dari proses hidrolisis air dari molekul sampel, kemudian berkombinasi dalam bentuk asam. spektrum serapan telah diukur menggunakan spektrofotometer Uv-Vis pada rentang panjang gelombang 200-700 nm, menghasilkan penurunan serapan pada puncak 360 dan 440 nm dengan peningkatan dosis dan kenaikan serapan optik pada puncak 560 nm dengan kenaikan dosis radiasi.  Kata kunci : Sifat optik, radiasi sinar gamma, polimer film PVA-TCA-MB, spektrum serapan optik. Abstract: The effect of gamma irradiation on optical properties  of methylene-blue dyed poly vinyl alcohol (PVA) blended with trichloroacetid acid (TCA) for use in dosimetry and measurement of radiation dose in gamma rays have been studied using Uv-Visible spectrophotometer method. The dosimeters were irradiated for doses up 14 kGy using 60Co gamma rays source at a constant dose rate. The polymeric films undergo colour change from blue purplish to yellow due to radiation-induced. The changes of this colour indicated strong acid, by the increasing of radiation dose caused more chlorine ions break from carbon of TCA and radiation-induced H+ and OH- free radicals are generated from the hydrolysis of water molecules, they then combined to form acid. The absorption spectra were measured using Uv-Visible spectrophotometer in the wavelength range 200-700 nm, resulting in a decrease of the absorbance at 360 and 440 nm band peak with increasing dose and an increases of the absorbance at 560 nm band peak with increasing dose. Keywords: Optical properties, gamma irradiation, polymer film PVA-TCA-MB, optical absorption spectra.


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