HAEMOPOIETIC DEVELOPMENT IN THE FOETAL LAMB FROM 85-135 DAYS MEASURED BY (3 H)-THYMIDINE INCORPORATION IN VITRO

1986 ◽  
Vol 64 (4) ◽  
pp. 357-365
Author(s):  
TC Smeaton
Keyword(s):  
Thymidine Incorporation ◽  
Foetal Lamb

Proliferative Effect of Tilapia Fish (Oreochromis niloticus) Lectin on BALB/c Mice Splenocytes

2019 ◽  
Vol 26 (12) ◽  
pp. 887-892
Author(s):  
Cynarha Daysy Cardoso da Silva ◽  
Cristiane Moutinho Lagos de Melo ◽  
Elba Verônica Matoso Maciel Carvalho ◽  
Mércia Andréa Lino da Silva ◽  
Rosiely Félix Bezerra ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Oreochromis Niloticus ◽  
Cytokine Production ◽  
Thymidine Incorporation ◽  
Con A ◽  
Cell Viability Assay ◽  
Proliferative Effect ◽  
Viability Assay ◽  
Apoptosis And Necrosis

Background: Lectins have been studied in recent years due to their immunomodulatory activities. Objective: We purified a lectin named OniL from tilapia fish (Oreochromis niloticus) and here we analyzed the cell proliferation and cytokine production in Balb/c mice splenocytes. Methods: Cells were stimulated in vitro in 24, 48, 72 hours and 6 days with different concentrations of OniL and Con A. Evaluation of cell proliferation was performed through [3H]-thymidine incorporation, cytokines were investigated using ELISA assay and cell viability assay was performed by investigation of damage through signals of apoptosis and necrosis. Results: OniL did not promote significant cell death, induced high mitogenic activity in relation to control and Con A and stimulated the cells to release high IL-2 and IL-6 cytokines. Conclusion: These findings suggest that, like Con A, OniL lectin can be used as a mitogenic agent in immunostimulatory assays.

scholarly journals INHIBITING EFFECT OF THE NEW CYTOTOXIC ANTIBIOTIC DAUNOMYCIN ON NUCLEIC ACIDS AND MITOTIC ACTIVITY OF HELA CELLS

1965 ◽  
Vol 27 (3) ◽  
pp. 545-550 ◽  
Author(s):  
A. Di Marco ◽  
R. Silvestrini ◽  
S. Di Marco ◽  
T. Dasdia
Keyword(s):  
Mitotic Activity ◽  
Rna Synthesis ◽  
Thymidine Incorporation ◽  
Acid Synthesis ◽  
Acetyl Derivative ◽  
Total Inhibition ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Higher Doses

The effect has been studied of Actinomycin D, Daunomycin (Da.), and Da. N acetyl derivative on mitotic activity and on the nucleic acid synthesis of in vitro HeLa cell cultures. The experiments were carried out by means of the radioautographic technique using stripping films. The relative uptake of thymidine-H3 and uridine-H3 was determined by means of the reduced silver grain count present in the nuclei of controls and treated cells. The mitotic activity and thymidine incorporation were noticeably reduced by Daunomycin and Actinomycin, whereas both processes appeared less affected by Da. N acetyl derivative. As regards nuclear RNA synthesis, all three antibiotics at low doses chiefly inhibit nucleolar RNA synthesis. On the other hand, whilst Actinomycin at higher doses causes an almost total inhibition of the synthesis of the whole nuclear RNA, in Daunomycin- and Da. N acetyl derivative-treated cells extranucleolar RNA synthesis is less susceptible to inhibition.

Effect of steroids on cartilage metabolism "in vitro"

1986 ◽  
Vol 113 (4_Suppl) ◽  
pp. S35-S40 ◽  
Author(s):  
Marc V.L. DU CAJU ◽  
Raoul P. ROOMAN
Keyword(s):  
Growth Factor ◽  
Thymidine Incorporation ◽  
Normal Serum ◽  
Synthetic Analogue ◽  
Factor Activity ◽  
Poor Growth ◽  
Cartilage Metabolism ◽  
Glucocorticoid Administration

ABSTRACT Conditions characterized by high levels of glucocorticoids are associated with poor growth. Serum somatomedin or insulin-like growth factor activity measured by cartilage bioassay systems is low, but is generally not accompanied by a fall in somatomedin concentration. Hydrocortisone and a synthetic analogue, dexamethasone, impaired the serum stimulated "in vitro" 35S sulphate and 3H-thymidine incorporation in porcine rib cartilage at physiological concentrations. Hydrocortisone added at a concentration of 0,1 μg/ml decreased the potency of normal serum to 50 % of controls. Dexamethasone was at least 10 times more potent. Removal of "in vitro" or "in vivo" administered hydrocortisone with dextran-coated charcoal restored the sulphate and thymidine activity to normal. We conclude that physiological amounts of glucocorticoids inhibit the "in vitro" porcine cartilage metabolism. Glucocorticoid administration "in vivo" does not abolish the activity of the cartilage stimulating effect of serum but affects cartilage metabolism directly or by the induction of locally produced inhibitors of cartilage metabolism.

scholarly journals Interleukin-6 (IL-6) is an intermediate in IL-1-induced proliferation of leukemic human megakaryoblasts

Blood ◽  
1990 ◽  
Vol 76 (10) ◽  
pp. 1972-1979 ◽  
Author(s):  
MA Brach ◽  
B Lowenberg ◽  
L Mantovani ◽  
U Schwulera ◽  
R Mertelsmann ◽  
...  
Keyword(s):  
Thymidine Incorporation ◽  
Interleukin 1 ◽  
Leukemic Cells ◽  
Megakaryoblastic Leukemia ◽  
Gm Csf ◽  
Endogenous Production ◽  
Neutralizing Monoclonal Antibody ◽  
In Vitro Effects ◽  
Stimulating Factor

Abstract We have examined the in vitro effects of recombinant human (rh) interleukin-1 (IL-1) on the growth of purified megakaryoblasts obtained from patients with acute megakaryoblastic leukemia. We demonstrate that both IL-1 alpha and IL-1 beta treatment of these cells led to stimulation of DNA synthesis (as shown by increase of 3H-thymidine incorporation up to 35-fold) and also resulted in colony formation of leukemic megakaryoblasts. However, the stimulatory effect of IL-1 was dependent on endogenous production of IL-6, because addition of neutralizing monoclonal antibody (MoAb) to IL-6 abrogated the stimulatory activity of IL-1. In contrast, neutralizing MoAbs to granulocyte (G)-colony stimulating factor (CSF), granulocyte-macrophage (GM)-CSF, and macrophage (M)-CSF failed to counteract the growth- enhancing effects of IL-1. Leukemic megakaryoblasts accumulated IL-6 mRNA and released IL-6 protein into their culture supernatant when exposed to rh IL-1 but failed to disclose transcripts for G-, GM-, and M-CSF under these conditions. Analysis of IL-6 receptor (IL-6R) transcript levels demonstrated that megakaryoblasts constitutively expressed IL-6R mRNA and that these transcripts are down-regulated to undetectable levels upon exposure to IL-1 and IL-6. Increase of 3H- thymidine incorporation by megakaryoblasts could be duplicated by exogenous IL-6 that could be blocked by neutralizing MoAb to IL-6. In conclusion, our results suggest that leukemic megakaryoblasts could produce and secrete IL-6, and express IL-6R, and that the growth- enhancing effect of IL-1 on these cells is indirect, via production of IL-6 by leukemic cells.

scholarly journals Reversal of Resistance to Methotrexate in L1210 Murine Leukemia by Uracil

Blood ◽  
1971 ◽  
Vol 38 (5) ◽  
pp. 648-656
Author(s):  
HARRY WALLERSTEIN ◽  
LEWIS M. SLATER ◽  
BEN ENG ◽  
NEIL CALMAN
Keyword(s):  
Survival Time ◽  
Dihydrofolate Reductase ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
L1210 Leukemia ◽  
Time Data ◽  
Multiple Generations ◽  
Methotrexate Resistance ◽  
Survival Time Data

Abstract BDF1 mice bearing L1210 leukemia, when treated with a regimen of uracil and methotrexate, show an increase in survival time greater than when treated with methotrexate alone. The uracil and methotrexate regimen also delays the development of methotrexate resistance as L1210 leukemia is transferred with therapy through multiple generations of mice. When uracil is applied to multiple generations of mice bearing tumor resistant to methotrexate, there is a return to sensitivity to methotrexate. It is also noted that uracil blocks the responsiveness of L1210 leukemia to 6-mercaptopurine. The responsiveness of these tumor lines to the addition of uracil in their regimens was monitored by in vitro tritiated thymidine incorporation into DNA and by dihydrofolate reductase activities. These data, when integrated with survival time data, suggest that in part, the reported results are mediated by a uracil-induced reduction in the availability of dihydrofolate reductase and phosphoribosylpyrophosphate.

Effects of growth hormone in vitro on the glucose metabolism of fetal rat islet β-cells

1996 ◽  
Vol 17 (2) ◽  
pp. 131-138 ◽  
Author(s):  
C Svensson
Keyword(s):  
Growth Hormone ◽  
Fetal Calf Serum ◽  
Thymidine Incorporation ◽  
Protein Biosynthesis ◽  
Calf Serum ◽  
Β Cells ◽  
Fetal Rat ◽  
Glucose Phosphorylation ◽  
Succinate Cytochrome C Reductase

ABSTRACT This study was undertaken to investigate the effects of growth hormone (GH) on the in vitro maturation of the metabolism of fetal rat islets. For this purpose fetal islets were obtained from 21-day-old fetuses by mild collagenase digestion of the pancreas and cultured in RPMI 1640 supplemented with 10% fetal calf serum. After one day the medium was changed and supplemented with 1% fetal calf serum with or without GH (1 μg/ml, human recombinant) and the islets cultured for another two days. Islets were then studied with regard to insulin secretion, (pro)insulin and total protein biosynthesis, glucose utilization and oxidation, thymidine incorporation, insulin and DNA contents and the contents of mRNAs for either insulin, adenine nucleotide translocator or cytochrome b. In addition, the activities of glucose phosphorylating enzymes and succinate-cytochrome c reductase were measured. Islets treated with GH showed increased insulin secretion in response to glucose, increased rates of glucose oxidation and utilization, increased thymidine incorporation and increased activities of succinate cytochrome c reductase and glucose phosphorylation at high glucose concentrations. There were, however, no changes in (pro)insulin and total protein biosynthesis, contents of insulin and DNA or the contents of any of the mRNAs. These combined data show that fetal β-cells are sensitive to growth hormone with respect to glucose metabolism, insulin release and DNA replication. The increased rates of islet glucose phosphorylation may reflect glucokinase activity and explain part of the increased insulin responsiveness to glucose of the fetal rat β-cell. These observations suggest that GH is of physiological significance for the maturation of the fetal β-cell.

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