Liquid scintillation counting techniques in lymphocyte transformation in vitro measured by tritiated thymidine uptake

1972 ◽  
Vol 1 (3) ◽  
pp. 263-272 ◽  
Author(s):  
E.A. Caspray ◽  
D. Hughes
1980 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Paolo Perocco ◽  
Angela Fini

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.


1974 ◽  
Vol 140 (4) ◽  
pp. 977-994 ◽  
Author(s):  
Peter Lonai ◽  
Hugh O. McDevitt

In vitro antigen-induced tritiated thymidine uptake has been used to study the response of sensitized lymphocytes to (T,G)-A--L, (H,G)-A--L, and (Phe,G)-A--L in responder and nonresponder strains of mice. The reaction is T-cell and macrophage dependent. Highly purified T cells (91% Thy 1.2 positive) are also responsive, suggesting that this in vitro lymphocyte transformation system is not B-cell dependent. Lymphocytes from high and low responder mice stimulated in vitro react as responders and nonresponders in a pattern identical to that seen with in vivo immunization. Stimulation occurs only if soluble antigen is added at physiological temperatures; antigen exposure at 4°C followed by washing and incubation at 37°C fails to induce lymphocyte transformation. Stimulation is specific for the immunizing antigen and does not exhibit the serologic cross-reactivity which is characteristic of these three antigens and their respective antisera. The reaction can be inhibited by anti-H-2 sera but not by anti-immunoglobulin sera. The anti-immunoglobulin sera did, however, inhibit lipopolysaccharide or pokeweed mitogen stimulation. These results suggest that the Ir-1A gene(s) are expressed in T cells, and that there are fundamental physiologic differences between T- and B-cell antigen recognition.


1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 225-230
Author(s):  
Roland Arnould ◽  
Jacque Dubois ◽  
Fokri Abikhalil ◽  
Anita Libert ◽  
Ghanem Ghanem ◽  
...  

The sensitivity and the selectivity of two murine lymphoid cell lines (P388 and P388D1) to five chemotherapeutic drugs were investigated in vitro. The cytotoxicities of melphalan, daunorubicin, hexamethylmelamine (HMM), hydroxymethylpentamethylmelamine and dihydroxymethyltetramethylmelamine, two HMM derivatives, were measured in the two cell lines using two different techniques: reduction of a tetrazolium derivative (MTT) and tritiated thymidine uptake into DNA. Cytotoxicity was expressed by the 50% inhibitory concentration (IC50) after one hour and after exposure of cells to each drug for two days. The IC50 results indicate that the P388 cells were generally more sensitive to melphalan, daunorubicin, hydroxymethylpentamethylmelamine and dihydroxymethyltetramethylmelamine than the P388D1 cell line. HMM was found to be inactive in both cell lines. Despite the lower sensitivity of the P388D1 cell line compared with the P388 cell line, because of its greater homogeneity, it could replace the P388 line for the in vitro assays, bearing in mind that the P388D1 cell line sensitivity is 1.21 - 24.63 times lower than that of the P388 cell line, at least as far as the drugs tested are concerned. Moreover, our results emphasise that variations of sensitivity could occur with repeated passage in vitro.


1971 ◽  
Vol 49 (9) ◽  
pp. 1541-1549 ◽  
Author(s):  
Antoine Simard

Since previous investigations had suggested that kinetin, like auxin, may initiate DNA synthesis in tobacco pith cells, a study was undertaken to learn whether the observed incorporation of tritiated thymidine into nuclear DNA in the presence of kinetin could be explained by different experimental factors.Pith tissues were isolated and allowed to rest a few days after excision and they were then placed on White's basic medium or on that medium supplemented with either one or both of the growth regulators in the presence of tritiated thymidine.The results of those studies, obtained by radioautographic and liquid scintillation counting methods, showed no statistically significant differences between pith tissues kept on the control medium and those on kinetin-containing medium. Similar tissues placed on an auxin or auxin- and kinetin-containing medium showed, as expected, a significant incorporation of tritiated thymidine into the DNA of pith cell nuclei.


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