Effects of erythropoietin on cell populations and macromolecular syntheses in foetal mouse erythroid cells

Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 453-472
Author(s):  
John Paul ◽  
David Conkie ◽  
Hugo Burgos
Keyword(s):  
Dna Synthesis ◽  
Mouse Liver ◽  
Rna Synthesis ◽  
Normal Development ◽  
Cell Populations ◽  
Erythroid Cells ◽  
Short Term ◽  
Cell Compartments ◽  
Normal Series

The effects of erythropoietin on maturation of erythroid cells were studied in short-term cultures of foetal mouse liver. Erythropoietin-treated cultures had about 50% more cells than untreated cultures after 24 h. The increase occurred in basophilic, polychromatic and orthochromatic erythroblasts as well as in reticulocytes. A striking feature of erythropoietin-treated cultures was the formation of macro-erythroblasts and macrocytes. Autoradiographic studies indicated that a maturation division was omitted in the formation of these cells and that macrocytes might be derived directly from polychromatic erythroblasts or earlier stages. These studies also indicated that there might be no more than three divisions during the normal development of orthochromatic erythroblasts from proerythroblasts in vitro. The mitotic index of proerythroblasts was raised in erythropoietin-treated cultures within 1–2 h. Moreover, erythropoietin caused a marked elevation of DNA synthesis in proerythroblasts within the first hour of culture but effects on DNA synthesis in other cell compartments were not pronounced. In contrast, an increase in RNA synthesis was noted in proerythroblasts and basophilic and polychromatic erythroblasts; it was greatest in the two former compartments. The stimulation was noticeable, especially in the basophilic compartment, within 2 h but increased progressively throughout the first 5–6 h. Erythropoietin did not induce an increase in total protein synthesis in cells of the normal series but macro-erythroblasts exhibited proportionately more grains.

Effect of Daunorubicin and Adriamycin on Nucleic ACID Synthesis of Serum Stimulated Mouse Embryo Fibroblasts

1977 ◽  
Vol 63 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Rosanna Supino ◽  
Anna M. Casazza ◽  
Aurelio Di Marco
Keyword(s):  
Dna Synthesis ◽  
Mouse Embryo ◽  
Rna Synthesis ◽  
Calf Serum ◽  
Acid Synthesis ◽  
Anthracycline Antibiotics ◽  
Simple Method ◽  
Mouse Embryo Fibroblasts ◽  
Embryo Fibroblasts

This paper reports the effects of daunorubicin and adriamycin on DNA and RNA synthesis of in vitro cultured mouse embryo fibroblasts (MEF) stimulated by fetal calf serum (FCS). The addition of FCS to quiescent MEF cultures brings about a wave of RNA synthesis, followed by DNA synthesis which starts between 8 and 12 h after change of medium and proceed for up to 24 h. These cells are therefore partially synchronized. The level of DNA synthesis depends on the amount of FCS added. Daunorubicin and adriamycin are almost equally effective in inhibiting DNA synthesis, as well as cell proliferation, which takes place later. Adriamycin is more active than daunorubicin on RNA synthesis. In cultures treated for an 8 h period starting at different times after FCS addition, the highest DNA synthesis inhibition is achieved by treatment during the first 8 h, when DNA synthesis has not yet started. The cellular uptake of daunorubicin is constantly higher than that of adriamycin, in any experimental condition tested. The results show that FCS-stimulated MEF can provide a simple method for studying the effects of anthracycline antibiotics on partially synchronized cells.

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

1970 ◽  
Vol 48 (1) ◽  
pp. 29-38 ◽  
Author(s):  
S. NORDQVIST
Keyword(s):  
Nucleic Acids ◽  
Dna Synthesis ◽  
High Concentration ◽  
Short Term ◽  
Younger Women ◽  
Dna And Rna ◽  
Poorly Differentiated ◽  
Endometrial Carcinomas ◽  
Dose Dependent

SUMMARY Twenty-five endometrial carcinomas and three non-endometrial carcinomas were studied for the influence of various steroid hormones on the synthesis of DNA and RNA in short-term incubations in vitro. Endometrial carcinomas showed a dose-dependent sensitivity to progesterone in vitro, the response in both nucleic acids sometimes exceeding that of normal endometria. The mean reduction in DNA synthesis was to 46% and in RNA synthesis to 39% of the control values. Poorly differentiated carcinomas showed higher values of DNA synthesis than highly differentiated ones, as did carcinomas from younger women compared with those from older women. The response in vitro to progesterone was not correlated with these factors. Pregnenolone and a synthetic progestogen were less effective in vitro than progesterone. Oestradiol at a high concentration (20 μg/ml) in some cases significantly reduced the synthesis of both nucleic acids, possibly because of a specific 'toxic' action on the cells. No hormonal effects were observed in non-endometrial carcinomas.

Damage by Dichlorvos of Human Lymphocyte DNA

1980 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Paolo Perocco ◽  
Angela Fini
Keyword(s):  
Dna Synthesis ◽  
Human Lymphocyte ◽  
Tritiated Thymidine ◽  
Human Lymphocytes ◽  
Ultraviolet Rays ◽  
Thymidine Uptake ◽  
Short Term ◽  
In Vitro System ◽  
Tritiated Thymidine Uptake

The action of dichlorvos (2.2-dichlorovinyldimethyl phosphate) was studied with a short-term in vitro system which utilizes human lymphocytes. The parameters studied were the action exerted by the pesticide on scheduled (semiconservative) and unscheduled (reparative) DNA synthesis measured as tritiated thymidine uptake. The results obtained show that dichlorvos affects semiconservative DNA synthesis, damages human lymphocyte DNA inducing low reparative synthesis, and interferes with DNA repair processes after damage exerted by ultraviolet rays.

scholarly journals SPHEROIDAL AND RING NUCLEOLI IN AMPHIBIAN OOCYTES

1967 ◽  
Vol 35 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Nancy J. Lane
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Morphological Changes ◽  
Ambystoma Mexicanum ◽  
Entire Length ◽  
Short Term ◽  
Asymmetrical Pattern ◽  
Fibrillar Component

In maturing oocytes of the newt Triturus viridescens, the nucleoli undergo a series of morphological changes that are very similar to those described by Callan for the axolotl, Ambystoma mexicanum. The nucleoli first assume the form of spheroids which then become extended into ring or necklace shapes that are DNase-sensitive; in mature oocytes the nucleoli revert to a spheroidal form. Short term in vitro incorporation studies with uridine-3H on both species show that RNA synthesis occurs in a restricted, eccentric portion of the spheroidal nucleoli, thereby producing an asymmetrical pattern of labeling. In the ring forms, however, the localization of the radioactivity suggests that synthesis takes place symmetrically throughout their entire length. The changes in nucleolar morphology apparently reflect the fact that the component DNA has undergone a redistribution from a localized region in the spheroidal nucleoli to an extended circle in the rings; the patterns of uridine-3H incorporation, therefore, parallel the distribution of DNA in both the spheroidal and the ring nucleoli. Ultrastructurally, the nucleoli contain a fibrillar component that corresponds in position to that of the DNA. The typical spheroidal nucleolus consists of a fibrillar core situated eccentrically and surrounded by a hull of granular, ribonucleoprotein material. The ring nucleoli are composed of a central fibrous region that is ensheathed all around its circumference by a layer of similar granular material. This granular substance is thicker at intervals along the length of the rings, representing the "beads" of the necklaces.

DNA synthesis in the developing rat brain

1969 ◽  
Vol 47 (1) ◽  
pp. 47-50 ◽  
Author(s):  
Shan-Ching Sung
Keyword(s):  
Dna Synthesis ◽  
Rat Brain ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Rapid Rate ◽  
In Vitro Synthesis ◽  
Infant Rat ◽  
Developing Rat

The in vitro synthesis of DNA as measured by the incorporation of thymidine-2-14C into DNA has been studied for various regions of the infant rat brain. Both intact cerebellum and cell-free extracts of cerebellum from newborn and infant rat brain showed a very rapid rate of DNA synthesis which was highest around 6 days after birth and decreased rapidly thereafter up to 18 days. This DNA synthesis in developing rat brain was strongly inhibited by hydroxyurea but was much less sensitive than was RNA synthesis to inhibition by actinomycin D.

scholarly journals The effect of sinefungin on the macromolecular biosynthesis of Leishmania species

2018 ◽  
Vol 49 (2) ◽  
pp. 137
Author(s):  
A. TZORA (Α. ΤΖΩΡΑ) ◽  
F. LAWRENCE ◽  
M. ROBERT-GERO
Keyword(s):  
Dna Synthesis ◽  
Mode Of Action ◽  
Rna Synthesis ◽  
In Vitro Study ◽  
Leishmania Species ◽  
Sensitive Strain ◽  
Vitro Study ◽  
No Inhibition ◽  
Main Target

The aim of the work presented here was the in vitro study of the action of the antibiotic sinefungin on the macromolecules DNA, RNA and the proteins of different isolates of Leismannia spp. in relation to the resistance or to the sensitivity of the strains examined. The mode of action of sinefungin of the Leishmania strains was detected by incorporating radiolabeled thymidine, uridine and leucine into promastigote forms, to study the synthesis of DNA, RNA and proteins respectively. In the sensitive strain L. tropica a statistically significant reduction of the rate of incorporation of thymidine to the DNA of the parasite, resulted to a 64% inhibition of leishmanial DNA synthesis by sinefungin at a concentration of 2.6 mM, when the time of action of the drug was 24 hours. In the sensitive strain L. tropica the reduction of the rate of incorporation of thymidine was depended on the concentration and the time of action of the drug. No inhibition of leishmanial RNA synthesis was observed. Our research showed that the action of the antibiotic sinefungin to the macromolecular biosynthesis of the protozoan Leishmania is independent of the strain and is strongly related with the expression of the sensitivity and the resistance of the strain. The main target of the antibiotic examined was the DNA of the Leishmania strains sensitive to the drug.

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.

OBSERVATIONS ON THE EFFECTS OF METHANOL AND FORMALDEHYDE ON ESTABLISHED CELL LINES CULTIVATED IN VITRO

1963 ◽  
Vol 41 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Alice Elliott ◽  
Donald M. Pace
Keyword(s):  
Cell Lines ◽  
Mouse Liver ◽  
Human Lung ◽  
Liver Cells ◽  
Short Term ◽  
Skin Cells ◽  
Established Cell Lines ◽  
Established Cell ◽  
High Concentrations

Short-term experiments were used to investigate the effects of various concentrations of methanol and formaldehyde upon cells grown in vitro. Mouse liver epithelial, HeLa, human lung, and skin cells were exposed to several concentrations of methanol. The same cell lines, except HeLa, were subjected to different concentrations of formaldehyde.Relatively high concentrations of methanol were required to produce rapid toxic effects. Not all cell lines responded alike to methanol. Concentrations of 15 mg/ml were decidedly inhibitory in case of human skin, lung, and HeLa cells. This concentration, however, appeared to enhance growth in liver cells. At higher concentrations the methanol was toxic to liver cells as well as to the others.Concentrations of formaldehyde greater than 0.035 mg/ml were toxic to mouse liver, human lung and skin cells. A concentration of 0.01 mg/ml of formaldehyde inhibited proliferation of these same cells. These three cell lines did not appear to differ significantly in respect to their sensitivity to formaldehyde. Of the substances investigated to date, formaldehyde appears to be the most toxic.

scholarly journals EFFECT OF GROWTH HORMONE ON THE METABOLISM OF THYMUS AND ON THE IMMUNE RESPONSE AGAINST SHEEP ERYTHROCYTES

1971 ◽  
Vol 134 (5) ◽  
pp. 1095-1113 ◽  
Author(s):  
M. R. Pandian ◽  
G. P. Talwar
Keyword(s):  
Growth Hormone ◽  
Immune Response ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Calf Serum ◽  
Lymphoid Organs ◽  
Stimulatory Action ◽  
Early Action ◽  
Stimulation Of

The effect of pituitary growth hormone on the biosynthesis of DNA in the thymus and other lymphoid organs, as well as the ability of the rat to respond immunologically to sheep red blood cells, has been evaluated. There is a marked reduction in plaque-forming cells, hemagglutination titers, and DNA synthesis in animals when examined at 15 wk after hypophysectomy. Administration of bovine growth hormone (BGH) leads to the enhancement of DNA synthesis in lymphoid organs and recovery of the immune response. Similar effects of the hormone are observed in plateaued rats. Injection of rabbit anti-BGH globulins, in contrast to normal rabbit globulins, over 5 days causes a drop in the weight of the thymus and in the rate of DNA synthesis in this organ. The thymus is also the organ in which stimulation of DNA synthesis is observed at a time period earlier than the spleen and lymph nodes after a single injection of BGH. The hormone stimulates not only the incorporation of thymidine-3H into DNA in the cortical cells, but also the incorporation of sodium sulfate-35S into TCA-insoluble biopolymers reported to be elaborated in the medullary area of the thymus. An in vitro system for the action of BGH on the thymus has been described. There is an obligatory requirement for calcium, but not for fetal calf serum in the medium for the hormone effect. An early action of the hormone is the enhanced incorporation of uridine-G-3H into RNA in thymocytes which is followed by a stimulation of the synthesis of proteins and DNA. The stimulatory action of growth hormone on RNA synthesis is not because of a facilitated uptake of the radioactive uridine by the cells under hormonal influence, a mechanism by which insulin is observed to increase RNA synthesis in thymocytes in vitro. The action of growth hormone on thymocytes is specific, since thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and heat-inactivated growth hormone are not effective. BGH has also a beneficial action on the regeneration of the thymus and spleen in starved rats.

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