Chromosome breaking activity of A139 in human lymphocytes in vitro

Zusammenfassung 2,5-bis-(methoxyäthoxy)-3,6-bis-äthylenimino-p-benzochinon (Bayer A 139) induziert dosisabhängig Chromatidenaberrationen in menschlichen Lymphozyten in vitro. Die intrachromosomale Aberrationsverteilung ist nicht zufällig.

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I thank Mrs.R. Pieper for her careful technical assistance. I am also grateful to the firm Bayer, Leverkusen, for supplying the A 139.     

Effect of folate and folinate on3H-thymidine incorporation by transforming human lymphocytes in vitro

Summary The incorporation of³H-thymidine by Concanavalin A-stimulated human peripheral blood lymphocytes in vitro is inhibited by the presence of folate or folinate in the culture medium in a concentration-dependent manner.     

Chromosome aberrations in in vitro irradiated lymphocytes from human cord blood

Summary An in vitro dose effect curve of dicentric chromosome aberrations in human cord blood lymphocytes has been obtained for 250-kV X-rays. This is compared with a curve prepared in an identical manner using blood from adults. The comparison shows a marginally higher dicentric yield in blood of newborns at doses above about 250 rads.Acknowledgment. We wish to thank Miss P. Orledge of the John Radcliffe Hospital, Oxford, for samples of cord blood, Mr M.J. Corp of the MRC Radiobiology Unit, Harwell, for irradiating the samples and Mr A.A. Edwards of NRPB, for help with statistics. The work was partly supported by Euratom Contract No. 171-76-1 BIO UK.     

Stimulation of growth by insulin inDrosophila embryonic cells in vitro

Summary For obtaining a better yield of established lines of embryonicDrosophila cells, insulin proved to be a useful substance to be added to the culture medium. 10% of lines became established, showing a predominatly diploid chromosome number.     

The effects of non-thermal radio frequency radiation on human lymphocytes in vitro

Zusammenfassung Hypotonische Streuungen, die in radiobestrahlten Kulturen menschlicher Lymphozyten Chromosomenaberrationen erkennen liessen, traten dort siebenmal häufiger auf als in unbestrahlten Kulturen; offenbar das Ergebnis einer wärmefreien Bestrahlung. Trotz des Fehlens bedeutender Unterschiede in der DNA-Synthese, der Zellvergrösserung und im mitotischen Index zwischen bestrahlten und unbestrahlten Kulturen kam es zu Aberrationen.     

Chromosome aberrations in in vitro irradiated lymphocytes from human cord blood.

An in vitro dose effect curve of dicentric chromosome aberrations in human cord blood lymphocytes has been obtained for 250-kV X-rays. This is compared with a curve prepared in an identical manner using blood from adults. The comparison shows a marginally higher dicentric yield in blood of newborns at doses above about 250 rads.     

alpha-Mercaptopropionyl-glycine influence on the in vitro proliferative response of human lymphocytes.

The effect of alpha-mercaptopropinyl-glycine on the in vitro proliferative response of healthy subjects' lymphocytes was studied. Low doses of the drug enhanced spontaneous lymphocyte blastigenesis but had no effect on the PHA-induced blastic response. With increasing concentrations of alpha-mercaptopropionyl-glycine inhibition of 3H-thymidine incorporation was found in unstimulated as well as in PHA stimulated lymphocytes.     

Stimulation of the in vitro biosynthesis of corticosteroids by angiotensin II

Zusammenfassung In Rindenschnitten frischer Rindernebennieren stimulierte Angiotensin II den Einbau von 1-C¹⁴-Acetat in Mineralo- und Glukocorticosteroide, hatte jedoch keinen Effekt auf die Transformation von 4-C¹⁴-Cholesterin und 4-C¹⁴-Progesteron. Der Angriffspunkt des Angiotensins scheint danach in Synthesebereichen vor der Cholesterinbildung zu liegen.     

Stimulation of peripheral guinea pig blood lymphocytes by autologous epidermal cells]

Using a strictly autologous (and not syngeneic) mixed culture system in the guinea-pig, it was shown that Mitomycin C treated ear epidermal cells (E) were capable of stimulating peripheral blood lymphocytes (L) from the same animal. The proliferative response of the lymphocytes as measured by 3H thymidine incorporation, is optimal on the 5th day of culture, and when the ratio of the concentrations of the two cell populations (L : E) is 1 : 1. The autoreactivity of the lymphocytes varies with the animal.     

Differences in in vitro incorporation of tritiated deoxycytidine and tritiated thymidine into human lymphocytes

Summary Human lymphocytes stimulated in vitro by PHA or PWM incorporate³H-CdR into DNA, but less well than³H-TdR. More³H-CdR is incorporated in populations enriched for T cells. No³H-CdR is used by cells stimulated by lipopolysaccharides under circumstances in which³H-TdR is incorporated. We conclude that human T cells and B cells differ in their ability to use³H-CdR.     

Differences in in vitro incorporation of tritiated deoxycytidine and tritiated thymidine into human lymphocytes.

Human lymphocytes stimulated in vitro by PHA or PWM incorporate 3H-CdR into DNA, but less well than 3H-TdR. More 3H-CdR is incorporated in populations enriched for T cells. No 3H-CdR is used by cells stimulated by lipopolysaccharides under circumstances in which 3H-TdR is incorporated. We conclude that human T cells and B cells differ in their ability to use 3H-CdR.     

Studies on human lymphocytes stimulated in vitro with anti-γ and anti-μ antibodies

Zusammenfassung Es konnte gezeigt werden, dass sich menschliche periphere Lymphozyten, mit Antikörper gegen die H-Ketten des-Globulins behandelt, in Lymphoblasten umwandeln lassen und dass sie in vitro DNA synthetisieren.