CELL DIVISION RATES OF EUCARYOTIC ALGAE MEASURED BY TRITIATED THYMIDINE INCORPORATION INTO DNA: COINCIDENT MEASUREMENTS OF PHOTOSYNTHESIS AND CELL DIVISION OF INDIVIDUAL SPECIES OF PHYTOPLANKTON ISOLATED FROM NATURAL POPULATIONS

1986 ◽  
Vol 22 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Richard B. Rivkin ◽  
Mary A. Voytek
Keyword(s):  
Cell Division ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Natural Populations ◽  
Individual Species

A STUDY OF BLASTOCYSTS DURING DELAY AND SUBSEQUENT IMPLANTATION IN LACTATING MICE

1968 ◽  
Vol 42 (3) ◽  
pp. 453-463 ◽  
Author(s):  
ANNE McLAREN
Keyword(s):  
Dna Synthesis ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Uterine Horn ◽  
Uterine Epithelium ◽  
Serial Sections ◽  
Uterine Lumen ◽  
Fresh State

SUMMARY Blastocysts were studied on the 5th and 8th day of pregnancy in lactating mice, in the fresh state, flushed from the uterus, in squash preparations and in serial sections. At the earlier period some mitosis was observed. Tritiated thymidine incorporation studies gave some evidence of DNA synthesis on the 5th and 6th days of pregnancy. By the 8th day the blastocysts were longer, contained more cells, and mitosis had ceased. They were located at the anti-mesometrial end of the uterine lumen, closely apposed to the uterine epithelium, and with their long axes parallel to the long axis of the uterine horn. Implantation could be induced, either by the removal of the litter, or by the injection of an appropriate dose of oestrogen on the 5th or 7th (but not the 4th) day of pregnancy. Both treatments were followed by the appearance of W-bodies in the neighbourhood of the blastocysts, the disappearance of the shed zonae, and the appearance of Pontamine Blue reactivity, oedema of the uterine stroma and formation of the primary decidual zone, in that order.

Cell division and cell allocation in early mouse development

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 37-51
Author(s):  
S. J. Kelly ◽  
J. G. Mulnard ◽  
C. F. Graham
Keyword(s):  
Cell Division ◽  
Tritiated Thymidine ◽  
Mouse Embryos ◽  
Mouse Development ◽  
Stages Of Development ◽  
Cell Stage ◽  
Cell Cycles ◽  
Short Cell ◽  
Early Mouse

Cell division was observed in intact and dissociated mouse embryos between the 2-cell stage and the blastocyst in embryos developing in culture. Division to the 4-cell stage was usually asynchronous. The first cell to divide to the 4-cell stage produced descendants which tended to divide ahead of those cells produced by its slow partner at all subsequent stages of development up to the blastocyte stage. The descendants of the first cell to divide to the 4-cell stage did not subsequently have short cell cycles. The first cell or last cell to divide from the 4-cell stage was labelled with tritiated thymidine. The embryo was reassembled, and it was found that the first pair of cells to reach the 8-cell stage contributed disproportionately more descendants to the ICM when compared with the last cell to divide to the 8-cell stage.

Interleukin 6 stimulates growth of vascular smooth muscle cells in a PDGF-dependent manner

1991 ◽  
Vol 260 (5) ◽  
pp. H1713-H1717 ◽  
Author(s):  
U. Ikeda ◽  
M. Ikeda ◽  
T. Oohara ◽  
A. Oguchi ◽  
T. Kamitani ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Interleukin 6 ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Muscle Cells ◽  
Thymidine Uptake ◽  
Dependent Manner

We have investigated the effect of interleukin 6 (IL-6) on the growth of vascular smooth muscle cells (VSMC) isolated from rat aortas. Murine recombinant IL-6 significantly increased the number of VSMC and stimulated tritiated thymidine incorporation into VSMC in a dose-dependent manner. The IL-6-induced thymidine incorporation into VSMC was totally inhibited by the Ca2+ channel blocker verapamil; however, IL-6 showed no effects on the intracellular Ca2+ level ([Ca2+]i) in VSMC. Antibody against platelet-derived growth factor (PDGF) also totally inhibited the IL-6-induced thymidine uptake. PDGF caused a significant increase in the [Ca2+]i, which was totally inhibited by verapamil. IL-6 mRNA was not detected in unstimulated “quiescent” VSMC, but its expression was stimulated by exposure of VSMC to 10% fetal bovine serum. Immunohistochemical study using anti-PDGF antibody showed that IL-6 stimulated PDGF production in VSMC. These results support the premise that IL-6 is released by VSMC in an autocrine manner and promotes the growth of VSMC via induction of endogenous PDGF production.

scholarly journals Temporal patterns of cell division in natural populations of endosymbiotic algae

1983 ◽  
Vol 28 (5) ◽  
pp. 1009-1014 ◽  
Author(s):  
F. P. Wilkerson ◽  
G. Muller ◽  
Parker L. Muscatine
Keyword(s):  
Cell Division ◽  
Natural Populations ◽  
Temporal Patterns ◽  
Endosymbiotic Algae

Duration of Availability of Tritiated Thymidine Following Intraperitoneal Injection

1968 ◽  
Vol 3 (1) ◽  
pp. 89-93
Author(s):  
W. K. BLENKINSOPP
Keyword(s):  
Cell Division ◽  
Intraperitoneal Injection ◽  
Deoxyribonucleic Acid ◽  
Direct Evidence ◽  
Tritiated Thymidine ◽  
Indirect Evidence ◽  
Acid Synthesis ◽  
Single Intraperitoneal Injection ◽  
Deoxyribonucleic Acid Synthesis

Much indirect evidence supports the assumption that tritiated thymidine does not label cells which enter the deoxyribonucleic acid synthesis phase (S) more than 1 h after injection. Direct evidence confirming this assumption was obtained by counting labelled epithelial nuclei in mice killed 1, 4 or 6 h after a single intraperitoneal injection of [3H]thymidine; colchicine was used to prevent the increase in number of labelled nuclei which would otherwise have occurred because of cell division. The proportion of cells labelled was the same at 1 h as at 4 or 6 h after injection of [3H]thymidine. Nuclei were regarded as labelled if they were overlaid by 4 grains or more; comparison of nuclear and background labelling indicated that nuclei overlaid by 3 grains or less represented background labelling.

Timing of nucleolar DNA replication in Amoeba proteus

1976 ◽  
Vol 22 (3) ◽  
pp. 521-530
Author(s):  
I. Minassian ◽  
L.G. Bell
Keyword(s):  
Electron Microscope ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Central Region ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
G2 Phase

Light- and electron-microscope autoradiography have been used to follow the incorporation of [3H]thymidine at different stages during the interphase of synchronously growing populations of Amoeba proteus. Two main patterns were found for tritiated thymidine incorporation, i.e. DNA synthesis. The major incorporation was in the central region of the nucleus, but a lesser degree of incorporation occurred in the nucleolar region. The bulk of this nucleolar DNA was found to be late replicating, i.e. it replicated during the G2 phase.

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.

Sign in / Sign up

Export Citation Format

Share Document