Related Experiment Video

Updated: Jul 3, 2026

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior
10:52

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

Published on: April 13, 2016

Protective bystander effects simulated with the state-vector model

Helmut Schöllnberger1, Peter M Eckl

  • 1Department of Materials Engineering and Physics, Division of Physics and Biophysics, University of Salzburg, Hellbrunnerstrasse 34, Salzburg, Austria. helmut.schoellnberger@sbg.ac.at

Dose-Response : a Publication of International Hormesis Society
|July 24, 2008
PubMed

Insights

Low-dose radiation exposure can trigger protective apoptosis in bystander cells, a mechanism modeled by the State-Vector Model (SVM) to explain reduced cancer transformation frequencies in human cells.

Area of Science:

  • Radiation biology
  • Cellular mechanisms
  • Cancer research

Background:

  • Apoptosis in non-hit bystander cells is a key response to low-dose, low-linear energy transfer (LET) radiation.
  • Understanding this mechanism is crucial for accurate modeling of radiation-induced biological effects.
  • Previous models did not fully incorporate bystander effects.

Purpose of the Study:

  • To implement apoptosis in non-hit bystander cells into a multistage model for in vitro neoplastic transformation.
  • To test the enhanced model, the State-Vector Model (SVM), against experimental data.
  • To analyze the time-dependent nature of radiation-induced protective apoptosis.

Main Methods:

  • Developed a deterministic multistage model (SVM) incorporating bystander apoptosis.
  • Tested the SVM on two datasets of human hybrid cell line CGL1 exposed to gamma radiation.
  • Analyzed data for both immediate and delayed plating conditions.

Main Results:

  • The SVM successfully described transformation frequencies reduced below spontaneous levels after low-dose gamma radiation.
  • Stronger protective effects were observed in delayed plating data compared to immediate plating.
  • The model's time-dependent solutions provided insights into the apoptosis-mediated protective process.

Conclusions:

  • The State-Vector Model (SVM) effectively simulates neoplastic transformation, accounting for radiation-induced bystander apoptosis.
  • The model's findings on protective effects align with experimental observations, particularly concerning plating conditions.
  • This work enhances understanding of low-dose radiation responses and their underlying cellular mechanisms.
Keywords:
LNTU-shapedapoptosisbystander effectlow doseneoplastic transformation

Related Concept Videos

Bystander Effect02:09

Bystander Effect

The discussion of bullying highlights the problem of witnesses not intervening to help a victim. This is a common occurrence, as the following well-publicized event demonstrates. In 1964, in Queens, New York, a 19-year-old woman named Kitty Genovese was attacked by a person with a knife near the back entrance to her apartment building and again in the hallway inside her apartment building. When the attack occurred, she screamed for help numerous times and eventually died from her stab wounds.
Pharmacodynamic Models: Direct Effect Model and Indirect Response Model01:29

Pharmacodynamic Models: Direct Effect Model and Indirect Response Model

Pharmacodynamic models are essential tools in understanding the relationship between drug concentrations and their effects on biological systems. By characterizing the dynamics of drug action, these models guide dose selection, optimize therapeutic efficacy, and inform the development of new drugs. Two major classes of pharmacodynamic models include direct effect and indirect response models.Direct Effect ModelsDirect effect models describe the immediate relationship between drug concentration...
Deindividuation00:57

Deindividuation

Deindividuation is a form of social influence on an individual’s behavior such that the individual engages in unusual or non-normal behavior while in a group setting. Why? Because in these group settings, the individual no longer sees themselves as an individual anymore, disinhibiting their behavior and personal restraint.
Actor-Observer Effect01:23

Actor-Observer Effect

The actor-observer effect, a cognitive bias closely linked to the fundamental attribution error, refers to the tendency for individuals to attribute their behavior to external, situational factors while explaining others’ behavior in terms of internal, dispositional traits. This asymmetry in attribution significantly influences social perception and judgment.Cognitive Mechanisms Behind the EffectTwo primary psychological mechanisms contribute to the actor-observer effect: differences in visual...
Pharmacodynamic Models: Additive and Proportional Drug Effect Model01:09

Pharmacodynamic Models: Additive and Proportional Drug Effect Model

Drug response models describe how pharmacological agents interact with biological systems to produce measurable effects. Baseline responses are inherent physiological activities without a drug significantly influencing the observed pharmacological outcomes. Depending on the drug response model employed, these baseline responses may combine with the drug's effect in either an additive or proportional manner.Additive Drug Response ModelIn the additive model, the drug effect is independent of the...
Mechanistic Models: Compartment Models in Individual and Population Analysis01:23

Mechanistic Models: Compartment Models in Individual and Population Analysis

Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least squares (OLS)...