FORMATION OF CELL COLONIES IN X-IRRADIATED REGENERATING LIVERS OF RATS

1965 ◽  
Vol 43 (6) ◽  
pp. 817-828 ◽  
Author(s):  
M. Maini Webber ◽  
H. F. Stich
Keyword(s):  
Partial Hepatectomy ◽  
Cell Population ◽  
Selection Pressure ◽  
Precancerous Lesion ◽  
Abnormal Chromosome ◽  
Cell Populations ◽  
Chemical Carcinogen ◽  
Normal Cells ◽  
Heterogeneous Cell Population ◽  
High Incidence

A high incidence of mitotic irregularities was observed when X-irradiated livers were induced to regenerate after a partial hepatectomy. Mitotic irregularities resulted in the formation of a heterogeneous cell population. As regeneration proceeded, the liver was found to be composed of two different cell populations: (i) one consisting of polyploid and aneuploid cells and incapable of giving rise to many descendants, and (ii) another consisting of apparently normal cells and capable of extensive proliferation which resulted in the formation of cell colonies. The regeneration of liver is mainly attributed to the cell colonies. No tumors appeared in the liver. These results demonstrate that a heterogeneous cell population of a "precancerous lesion" does not necessarily lead to the formation of a neoplasm. A selection pressure can be considered as necessary to favor the multiplication of cells with abnormal chromosome complements over that of cells with normal complements, as is seen in the livers of rats fed a chemical carcinogen. However, in the case of X-irradiated livers, normal cells seem to be favored.

COMBINED EFFECTS OF X-IRRADIATION AND 3′-METHYL-4-DIMETHYLAMINOAZOBENZENE ON LIVER CELL POPULATION

1965 ◽  
Vol 43 (6) ◽  
pp. 811-815 ◽  
Author(s):  
M. Maini Webber ◽  
H. F. Stich
Keyword(s):  
Partial Hepatectomy ◽  
Cell Population ◽  
Liver Cell ◽  
The Other ◽  
Cell Populations ◽  
Combined Effects ◽  
Normal Cells ◽  
Abnormal Cells ◽  
X Irradiation ◽  
Liver Cell Population

Livers of rats were exposed to 950 rads of X-irradiation. The liver cells were then induced to proliferate by the stimulus of partial hepatectomy. The regenerating livers consisted of two cell populations, one of colonies of ceils having normal amounts of DNA and the other having abnormal polyploid and aneuploid cells. Regeneration of the liver is attributed to the colonies with normal cells. When 3′-Me-DAB was fed to the X-irradiated animals, the behavior of these cell populations was reversed. The multiplication of abnormal cells was favored in the presence of the carcinogen. Changes in the percentage of mitotic irregularities, the mitotic rates, and the proportion of various stages of mitosis that resulted in the altered behavior of cell populations are discussed.

scholarly journals Satellite Cells: Regenerative Mechanisms and Applicability in Muscular Dystrophy

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Gustavo Torres de Souza ◽  
Rafaella de Souza Salomão Zanette ◽  
Danielle Luciana Aurora Soares do Amaral ◽  
Francisco Carlos da Guia ◽  
Claudinéia Pereira Maranduba ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Cell Population ◽  
Satellite Cells ◽  
Specific Pattern ◽  
Cell Populations ◽  
Heterogeneous Cell Population ◽  
Factor Expression ◽  
Transcription Factor Expression ◽  
Severe Tissue

The satellite cells are long regarded as heterogeneous cell population, which is intimately linked to the processes of muscular recovery. The heterogeneous cell population may be classified by specific markers. In spite of the significant amount of variation amongst the satellite cell populations, it seems that their activity is tightly bound to the paired box 7 transcription factor expression, which is, therefore, used as a canonical marker for these cells. Muscular dystrophic diseases, such as Duchenne muscular dystrophy, elicit severe tissue injuries leading those patients to display a very specific pattern of muscular recovery abnormalities. There have been works on the application of precursors cells as a therapeutic alternative for Duchenne muscular dystrophy and initial attempts have proven the cells inefficient; however later endeavours have proposed solutions for the experiments improving significantly the results. The presence of a range of satellite cells populations indicates the existence of specific cells with enhanced capability of muscular recovery in afflicted muscles.

Ultrastructural Changes in the Mammary Epithelial Cell Population During Neoplastic Development Induced by A Chemical Carcinogen.

1976 ◽  
Vol 34 ◽  
pp. 250-251 ◽  
Author(s):  
J. Russo ◽  
W. Isenberg ◽  
M. Ireland ◽  
I.H. Russo
Keyword(s):  
Mammary Gland ◽  
Cell Population ◽  
Virgin Female ◽  
Histological Change ◽  
Mammary Epithelial ◽  
Female Rats ◽  
Ultrastructural Changes ◽  
Post Inoculation ◽  
Chemical Carcinogen ◽  
Sprague Dawley

The induction of rat mammary carcinoma by the chemical carcinogen DMBA is used as a model for the study of the human disease (1). We previously described the histochemical changes that occur in the mammary gland of DMBA treated animals before the earliest manifested histological change, the intraductal proliferation (IDP), was observed (2). In the present work, we demonstrate that a change in the stable cell population found in the resting mammary gland occurs after carcinogen administration.Fifty-five day old Sprague-Dawley virgin female rats were inoculated intragastrically with 20mg of 7,12-dimethylbenz(a)anthracene (DMBA) in 1ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from control and inoculated rats were removed weekly from the time of inoculation until 60 days post-inoculation. For electron microscopy, the glands were immersed in Karnovsky's fixative, post-fixed in 1% OsO4, dehydrated, and embedded in an Epon-Araldite mixture. Thick (lμ) sections were stained with 1% toluidine blue and were used for selecting areas for ultrastructural study.

scholarly journals Discrete and continuum phenotype-structured models for the evolution of cancer cell populations under chemotherapy

2020 ◽  
Vol 15 ◽  
pp. 14 ◽  
Author(s):  
Rebecca E.A. Stace ◽  
Thomas Stiehl ◽  
Mark A.J. Chaplain ◽  
Anna Marciniak-Czochra ◽  
Tommaso Lorenzi
Keyword(s):  
Cancer Cell ◽  
Cell Population ◽  
Evolutionary Dynamics ◽  
Analytical Description ◽  
Chemotherapeutic Agents ◽  
Cell Populations ◽  
Theoretical Ground ◽  
Individual Based Model ◽  
Nonlocal Parabolic Equation ◽  
Epigenetic Drug

We present a stochastic individual-based model for the phenotypic evolution of cancer cell populations under chemotherapy. In particular, we consider the case of combination cancer therapy whereby a chemotherapeutic agent is administered as the primary treatment and an epigenetic drug is used as an adjuvant treatment. The cell population is structured by the expression level of a gene that controls cell proliferation and chemoresistance. In order to obtain an analytical description of evolutionary dynamics, we formally derive a deterministic continuum counterpart of this discrete model, which is given by a nonlocal parabolic equation for the cell population density function. Integrating computational simulations of the individual-based model with analysis of the corresponding continuum model, we perform a complete exploration of the model parameter space. We show that harsher environmental conditions and higher probabilities of spontaneous epimutation can lead to more effective chemotherapy, and we demonstrate the existence of an inverse relationship between the efficacy of the epigenetic drug and the probability of spontaneous epimutation. Taken together, the outcomes of the model provide theoretical ground for the development of anticancer protocols that use lower concentrations of chemotherapeutic agents in combination with epigenetic drugs capable of promoting the re-expression of epigenetically regulated genes.

Inactivation of Surface-adherent Listeria monocytogenes Hypochlorite and Heat

1991 ◽  
Vol 54 (1) ◽  
pp. 4-6 ◽  
Author(s):  
SHIN-HO LEE ◽  
JOSEPH F. FRANK
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Cell Population ◽  
Incubation Time ◽  
Cell Populations ◽  
Adherent Cell ◽  
Adherent Cells ◽  
D Cells

Inactivation by hypochlorite of Listeria monocytogenes cells adherent to stainless steel was determined. Adherent cell populations were prepared by incubating stainless steel slides with a 24 h culture of L. monocytogenes for 4 h at 21°C. Adherent microcolonies were prepared by growing L. monocytogenes on stainless steel slides submerged in a 1:15 dilution of tryptic soy broth at 21°C. The slides were then rinsed and transferred to fresh sterile broth every 2 d with a total incubation time of 8 d. Although the 4 h and 8 d adherent populations were at similar levels, 8 d adherent cells were over 100 times more resistant than the 4 h adherent cell population when exposed to 200 ppm hypochlorite for 30 s. When stainless steel slides containing adherent cells were heated at 72°C both adherent cell populations were inactivated after 1 min. Detectable numbers of L. monocytogenes remained on stainless steel slides after treatment at 65°C for 3 min when adherent 8 d cells were tested but not when adherent 4 h cells were used.

Chemical carcinogen alteration of SV40 virus induced transformation of normal human cell populations in vitro

1978 ◽  
Vol 22 (2-3) ◽  
pp. 185-197 ◽  
Author(s):  
George E. Milo ◽  
James R. Blakeslee ◽  
Ronald Hart ◽  
David S. Yohn
Keyword(s):  
Human Cell ◽  
Cell Populations ◽  
Chemical Carcinogen ◽  
Sv40 Virus ◽  
Normal Human Cell ◽  
Normal Human

High incidence of ultraviolet-B-or chemical-carcinogen-induced skin tumours in mice lacking the xeroderma pigmentosum group A gene

Nature ◽  
1995 ◽  
Vol 377 (6545) ◽  
pp. 165-168 ◽  
Author(s):  
Hironobu Nakane ◽  
Seiji Takeuchi ◽  
Shunsuke Yuba ◽  
Masafumi Saijo ◽  
Yoshimichi Nakatsu ◽  
...  
Keyword(s):  
Xeroderma Pigmentosum ◽  
Ultraviolet B ◽  
Chemical Carcinogen ◽  
Skin Tumours ◽  
High Incidence ◽  
Group A ◽  
Xeroderma Pigmentosum Group A

scholarly journals Kinetics of influenza A virus infections in a heterogeneous cell population

2021 ◽  
Author(s):  
Marc J. Baron
Keyword(s):  
Influenza A Virus ◽  
Cell Population ◽  
Influenza A ◽  
Virus Infections ◽  
Heterogeneous Cell Population ◽  
Kinetics Of

Kinetics of influenza A virus infections in a heterogeneous cell population

scholarly journals CyTOF workflow: differential discovery in high-throughput high-dimensional cytometry datasets

F1000Research ◽  
2019 ◽  
Vol 6 ◽  
pp. 748 ◽  
Author(s):  
Malgorzata Nowicka ◽  
Carsten Krieg ◽  
Helena L. Crowell ◽  
Lukas M. Weber ◽  
Felix J. Hartmann ◽  
...  
Keyword(s):  
Cell Population ◽  
High Throughput ◽  
Mixed Models ◽  
Exploratory Data Analysis ◽  
Linear Mixed Models ◽  
High Dimensional ◽  
Cell Populations ◽  
Dimensional Scaling ◽  
Exploratory Data

High-dimensional mass and flow cytometry (HDCyto) experiments have become a method of choice for high-throughput interrogation and characterization of cell populations. Here, we present an updated R-based pipeline for differential analyses of HDCyto data, largely based on Bioconductor packages. We computationally define cell populations using FlowSOM clustering, and facilitate an optional but reproducible strategy for manual merging of algorithm-generated clusters. Our workflow offers different analysis paths, including association of cell type abundance with a phenotype or changes in signalling markers within specific subpopulations, or differential analyses of aggregated signals. Importantly, the differential analyses we show are based on regression frameworks where the HDCyto data is the response; thus, we are able to model arbitrary experimental designs, such as those with batch effects, paired designs and so on. In particular, we apply generalized linear mixed models or linear mixed models to analyses of cell population abundance or cell-population-specific analyses of signaling markers, allowing overdispersion in cell count or aggregated signals across samples to be appropriately modeled. To support the formal statistical analyses, we encourage exploratory data analysis at every step, including quality control (e.g., multi-dimensional scaling plots), reporting of clustering results (dimensionality reduction, heatmaps with dendrograms) and differential analyses (e.g., plots of aggregated signals).

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