scholarly journals The effect of gamma irradiation on cell division in tissue culture in vitro .—Part II

1929 ◽  
Vol 105 (734) ◽  
pp. 93-98 ◽  
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Gamma Irradiation ◽  
Gamma Rays ◽  
X Rays ◽  
Tissue Cultures ◽  
Long Period ◽  
Silk Worm ◽  
Number Of Cells

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.

scholarly journals The effect of gamma irradiation on cell division in tissue culture in vitro

1927 ◽  
Vol 102 (714) ◽  
pp. 92-101 ◽  
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
X Rays ◽  
Tissue Cultures ◽  
Culture In Vitro ◽  
Form Part ◽  
Number Of Cells

The experiments described in the following paper were carried out in order to study the quantitative effects of gamma radiation upon mitosis in tissue cultures in vitro . They form part of a larger investigation into the causes of the disappearance of certain types of new growth as a result of irradiation. Strangeways and Oakley carried out qualitative experiments with X-rays on tissue cultures in vitro . They showed that there was a diminution in the number of cells undergoing mitosis. This has subsequently been shown in the case of radium by Canti and Donaldson.

Tests by Tissue Culture Methods on the Nature of Immunity Transplanted Skin

1948 ◽  
Vol s3-89 (7) ◽  
pp. 239-252
Author(s):  
P. B. MEDAWAR
Keyword(s):  
Tissue Culture ◽  
Cell Division ◽  
Epidermal Cell ◽  
Cell Suspensions ◽  
Acquired Immunity ◽  
Culture Methods ◽  
Division Frequency

The transplantation of skin from one rabbit to another elicits a reaction that conforms in main outline with that of an actively acquired immunity. The experiments described in this paper were designed to test the hypothesis that the regression of such grafts is secured by the action of antibodies demonstrable in vitro. Skin from adult rabbits has therefore been cultivated in the presence of serum and growing mesenchymal tissues derived solely from rabbits heavily and specifically immunized against it. Immune sera and tissues are without effect on the survival, cell-division frequency and migratory activities of explanted skin, and agglutinins for epidermal cell suspensions are not demonstrable in immune sera. With certain stated qualifications, it has therefore been concluded that the occurrence of free antibodies is not a sufficient explanation of the regression of skin homografts in vivo.

Bone Mineral (Apatite) Assay by Photon Scattering - A Survey of Sources and Experimental Evaluation

1974 ◽  
Vol 18 ◽  
pp. 545-556 ◽  
Author(s):  
Luther E. Preuss ◽  
Dennis G. Piper ◽  
Claudius Bugenis
Keyword(s):  
Bone Mineral Content ◽  
Bone Mineral ◽  
Gamma Rays ◽  
Experimental Evaluation ◽  
Mineral Content ◽  
Low Energy ◽  
X Rays ◽  
Photon Scattering ◽  
Energy Gamma

AbstractCurrent methods of measuring bone mineral content In vitro are either inaccurate or measure density in non-intuitive units. A recently developed system overcomes these difficulties by utilizing the Compton scattering of photons from bone. Two sources of monoenergetic photons with related properties are required. The range includes energetic x-rays and low energy gamma rays. This study analyzes a number of the possible nuclide source combinations, and reports experimental results accomplished with a 153Gd-170-Tm combination. In vitro measurement of the density of ox bones by this method agreed with Archimedean measurements within three percent.

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
Keyword(s):  
Radiation Dose ◽  
Gamma Irradiation ◽  
Gamma Rays ◽  
Cytological Study ◽  
Jerusalem Artichoke ◽  
Dna And Rna ◽  
Jerusalem Artichoke Tuber ◽  
Outer Area

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.

Immune responses to hapten conjugates in vitro

1975 ◽  
Vol 8 (4) ◽  
pp. 507-522
Author(s):  
Sirkka Kontiainen ◽  
O. Mäkelä ◽  
M. Hurme
Keyword(s):  
Tissue Culture ◽  
Immune Responses ◽  
Cell Types ◽  
Antibody Responses ◽  
Tissue Cultures ◽  
Cell Type ◽  
Animal Body ◽  
Do So

Several functions of the animal body can take place in cell or tissue cultures with almost unreduced efficiency and precision. Functions, where only one cell type is involved, often do so, but also some differentiation steps where interactions between two or more cell types are clearly needed can take place in tissue culture (Saxén et al. 1968).Most immune responses require collaboration between two or more cell types (Claman, Chaperon & Triplett, 1966; Miller & Mitchell, 1968; Feldmann & Nossal 1972c). Some of them can be easily induced in vitro but others cannot. Even when antibody responses can be induced in vitro their intensity varies a great deal. With some antigens and under some circumstances a response in vitro can be nearly as strong as one in vivo. A crude comparison can be derived from responses in vitro and in vivo to the same antigen, conjugate of hapten NIP and pneumococcal polysaccharide type III (NIP-SIll, Nakamura, Ray & Mäkelä, 1973).

scholarly journals Plant tissue culture environment as a switch-key of (epi)genetic changes

2019 ◽  
Vol 140 (2) ◽  
pp. 245-257 ◽  
Author(s):  
Piotr Tomasz Bednarek ◽  
Renata Orłowska
Keyword(s):  
Tissue Culture ◽  
Plant Tissue ◽  
Basic Research ◽  
Current Status ◽  
Epigenetic Changes ◽  
Tissue Cultures ◽  
Genetic Changes ◽  
Culture Stage ◽  
Commercial Applications

Abstract The in vitro tissue cultures are, beyond all difficulties, an essential tool in basic research as well as in commercial applications. Numerous works devoted to plant tissue cultures proved how important this part of the plant science is. Despite half a century of research on the issue of obtaining plants in in vitro cultures, many aspects remain unknown. The path associated with the reprogramming of explants in the fully functioning regenerants includes a series of processes that may result in the appearance of morphological, physiological, biochemical or, finally, genetic and epigenetic changes. All these changes occurring at the tissue culture stage and appearing in regenerants as tissue culture-induced variation and then inherited by generative progeny as somaclonal variation may be the result of oxidative stress, which works at the step of explant preparation, and in tissue culture as a result of nutrient components and environmental factors. In this review, we describe the current status of understanding the genetic and epigenetic changes that occur during tissue culture.

The action of the Cu2+, Ag+ and time inducing the in vitro anther culture-derived barley regenerants

2020 ◽  
Author(s):  
Piotr Tomasz Bednarek ◽  
Renata Orłowska
Keyword(s):  
Dna Methylation ◽  
Tissue Culture ◽  
De Novo ◽  
Culture Conditions ◽  
Ion Concentration ◽  
Tissue Cultures ◽  
Regeneration Medium ◽  
Green Plants ◽  
Anther Cultures

Abstract BackgroundPlant regeneration via anther cultures is a world-wide approach as it allows for the regeneration of uniform and homozygous double haploids. Recent studies have shown that in vitro cultures are the origin of the so-called tissue culture-induced variation (TCIV) that may lead to off-type regenerants. Moreover, the regeneration of green plants may be limited by the presence of albinos. It was demonstrated that the presence of Cu2+ and Ag+ ions in the regeneration medium might increase the number of green plants.ResultsDArTseqMet markers were evaluated based on regenerants and donor plants derived via in vitro anther cultures of barley. The regenerants were obtained under varying Cu2+ and Ag+ ion concentration in the regeneration medium during distinct time conditions of the tissue cultures. The DArTseqMet markers were quantified using a semi-quantitative MSAP approach delivering data on CG and CHG sequence contexts de novo methylation and demethylation. Under each tissue culture conditions, the number of regenerated green plants per 100 anthers was evaluated. Conditional moderation analysis was applied to test for the role of Cu2+ and Ag+ ions in the medium. Moreover, the importance of the time of in vitro anther cultures were analyzed.ConclusionsOur data demonstrate that DNA de novo methylation and demethylation affecting CG and CXG DNA sequence contexts is moderated by the presence of Cu2+ and Ag+ ions in the medium conditional on the time of in vitro tissue cultures. The level of de novo methylation and demethylation and the difference between the two is essential for the understanding of moderation. Moreover, Cu2+ and Ag+ play in concert moderating DNA methylation changes. For the in vitro tissue culture purposes, the lower the delta value equal to de novo methylation less demethylation and the higher the value of the (Cu+Ag) predictor conditional on time, the higher the number of green plants should be evaluated. Moreover, evaluation of GPs is even more probable under positive delta and higher (Cu+Ag) values. Our data are congruent with the putative function of these ions in the ethylene and DNA methylation pathways.

Oestrogen synthesis by bovine foetal placenta at normal parturition

1981 ◽  
Vol 98 (1) ◽  
pp. 112-118 ◽  
Author(s):  
K. Larsson ◽  
W. C. Wagner ◽  
M. Sachs
Keyword(s):  
Tissue Culture ◽  
Conversion Rate ◽  
Tissue Cultures ◽  
Peripheral Plasma ◽  
Conversion Rates ◽  
Phenolic Extraction ◽  
Percentage Conversion ◽  
Very High ◽  
Culture Conversion

Abstract. In vitro conversion of C19-[3H]androstenedione and C21-[3H]pregnenolone steroids to oestrogens was studied in tissue cultures prepared from bovine cotyledons collected 10–240 min after natural parturition. A total of 17 cows was used, 15 had normal parturitions and 2 cows required assistance due to weak and prolonged labour. At collection of tissues, blood samples were drawn from the cows and peripheral plasma oestrogen levels were determined by radioimmunoassay. Percentage conversion to unconjugated and conjugated oestrogens was estimated for each cow from 6 tissue culture replicates for each precursor. The steroids were extracted with toluene and separated by phenolic extraction and column chromatography. The repeatability of conversion rate was very high. Incubation with androstenedione yielded consistently higher conversion rates than incubation with pregnenolone. Independent of precursor the conversion rates, within cows, ranked unconjugated Oe1 > conjugated Oe1 > unconjugated Oe2 > conjugated Oe2. The conversion rates decreased significantly with increasing intervals from parturition to collection of material. Lower conversion rates were found for cultures of tissues from the 2 cows with weak labour when compared to cultures from normally calving cows. The sire of the foetus had an influence on conversion rate in the tissue cultures. The plasma oestrogen concentrations of the cows decreased significantly with an increased interval from parturition to blood-sampling. With the exception of one cow, the tissue culture conversion rates and the plasma oestrogen levels of the cows were significantly correlated.

scholarly journals The delayed lethal effect of radium on tissue cultures in vitro

1930 ◽  
Vol 106 (741) ◽  
pp. 44-49 ◽  
Keyword(s):  
Medical Research ◽  
Gamma Rays ◽  
Research Council ◽  
Medical Research Council ◽  
Lethal Effect ◽  
Tissue Cultures ◽  
Extensive Investigation ◽  
Made In

The following experiments were made in order to study the delayed lethal effect of gamma rays on tissue cultures vitro, using two different quantities of radium sulphate as the source of irradiation. The work forms part of a more extensive investigation into the causes of the destruction of certain types of new growth by means of radiotherapy. The expenses in connection with this study were met by a grant from the Medical Research Council, and my thanks are also due to the Radium Beige and Messrs. Watson & Sons for the loan of the radium employed.

scholarly journals MULTIPLICATION OF TUBERCLE BACILLI WITHIN MONONUCLEAR PHAGOCYTES IN TISSUE CULTURES DERIVED FROM NORMAL ANIMALS AND ANIMALS VACCINATED WITH BCG

1953 ◽  
Vol 97 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Emanuel Suter
Keyword(s):  
Tissue Culture ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Culture Medium ◽  
Normal Animal ◽  
Mononuclear Phagocytes ◽  
Tissue Cultures ◽  
Inhibition Of Growth ◽  
Intracellular Multiplication

When monocytes derived from normal guinea pigs or rabbits were infected with tubercle bacilli and cultivated in vitro, the bacilli multiplied abundantly within the cytoplasm of these cells. By contrast, intracellular multiplication of the bacilli was retarded or completely inhibited within the monocytes of rabbits or guinea pigs vaccinated with BCG. This inhibition of growth was observed with both virulent or attenuated strains of tubercle bacilli. Under the conditions used in the present study, the ability of monocytes to inhibit bacillary proliferation was the same whether serum from a normal animal or from vaccinated animals was used in the tissue culture medium. Moreover, the serum of vaccinated animals did not inhibit multiplication of tubercle bacilli within monocytes derived from a normal animal. The ability of guinea pig monocytes to interfere with intracellular bacillary proliferation was first perceptible 8 days after vaccination.

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