Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 1078821

Letter: Decrease in sensitivity of cells after split-dose recovery: evidence for the involvement of protein synthesis.

P E Bryant
View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

Cell SurvivalChlamydomonasChloramphenicolCycloheximideDose-Response Relationship, RadiationLeucinePlant ProteinsRadiation EffectsTritiumX-RaysJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P E Bryant. 1975. Letter: Decrease in sensitivity of cells after split-dose recovery: evidence for the involvement of protein synthesis.. https://doi.org/10.1080/09553007514550091

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2018

Chromatin architecture changes and DNA replication fork collapse are critical features in cryopreserved cells that are differentially controlled by cryoprotectants.

In this work, we shed new light on the highly debated issue of chromatin fragmentation in cryopreserved cells. Moreover, for the first time, we describe replicating cell-specific DNA damage and higher-order chromatin alterations after freezing and thawing. We identified DNA structural changes associated with the freeze-thaw process and correlated them with the viability of frozen and thawed cells. We simultaneously evaluated DNA defects and the higher-order chromatin structure of frozen and thawed cells with and without cryoprotectant treatment. We found that in replicating (S phase) cells, DNA was preferentially damaged by replication fork collapse, potentially leading to DNA double strand breaks (DSBs), which represent an important source of both genome instability and defects in epigenome maintenance. This induction of DNA defects by the freeze-thaw process was not prevented by any cryoprotectant studied. Both in replicating and non-replicating cells, freezing and thawing altered the chromatin structure in a cryoprotectant-dependent manner. Interestingly, cells with condensed chromatin, which was strongly stimulated by dimethyl sulfoxide (DMSO) prior to freezing had the highest rate of survival after thawing. Our results will facilitate the design of compounds and procedures to decrease injury to cryopreserved cells.

Cell Survival↗
PubMed2002

Efficient rejoining of radiation-induced DNA double-strand breaks in centromeric DNA of human cells.

Although major efforts in elucidating different DNA double-strand break (DSB) repair pathways and their contribution to accurate repair or misrepair have been made, little is known about the influence of chromatin structure on the fidelity of DSB repair. Here, the repair of ionizing radiation-induced DSBs was investigated in heterochromatic centromeric regions of human cells in comparison with other genomic locations. A hybridization assay was applied that allows the quantification of correct DSB rejoining events in specific genomic regions by measuring reconstitution of large restriction fragments. We show for two primary fibroblast lines (MRC-5 and 180BR) and an epithelial tumor cell line that restriction fragment reconstitution is considerably more efficient in the centromere than in average genomic locations. Importantly, however, DNA ligase IV-deficient 180BR cells show, compared with repair-proficient MRC-5 cells, impaired restriction fragment reconstitution both in average DNA and in the centromere. Thus, the efficient repair of DSBs in centromeric DNA is dependent on functional non-homologous end joining. It is proposed that the condensed chromatin state in the centromere limits the mobility of break ends and leads to enhanced restriction fragment reconstitution by increasing the probability for rejoining correct break ends.

Cell Survival↗
PubMed2002

Prosthetic metals have a variable necrotic threshold in human fibroblasts: an in vitro study.

The generation of metal particles from prosthetic joints has been an evolving problem in orthopedics. Numerous factors have been involved including cells, metals, and responding cytokines, but determining roles of these factors or cascades of factors has been elusive. This laboratory has published threshold levels for commercially pure titanium (CpTi), which led to cell necrosis, but noted that cell viability differed among donor patients. To compliment the previous work we examined two other metals, Tantalum (Ta) and cobalt-chrome (CoCr), while making comparative measurements in these different donor patients. Retrieved human fibroblasts (superior medial plica) were cultured in a standard manner and exposed to various dosages of the three metals. Cell counts and interleukin (IL) 6 were used as dependent variables within a three-way analysis of variance. The data show that fibroblast necrosis was significantly affected by both type and mass of metal, with each metal having a distinct threshold (CpTi most necrotic, followed by Ta and CoCr). The cell counts and IL-6 at control levels varied significantly among all three donors. However, the response to the metals and dosages did not differ among tissue donors. Thus, although each patient had a different starting value for cell counts and IL-6, they responded to the metal particles in the same proportionate manner.

Cell Survival↗