Publications by authors named "R Vasumathy"

2 Publications

  • Page 1 of 1

Dosimetry and radiobiological studies of automated alpha-particle irradiator.

J Environ Pathol Toxicol Oncol 2013 ;32(3):263-73

Mechanical Design and Prototype Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.

Understanding the effect of alpha radiation on biological systems is an important component of radiation risk assessment and associated health consequences. However, due to the short path length of alpha radiation in the atmosphere, in vitro radiobiological experiments cannot be performed with accuracy in terms of dose and specified exposure time. The present paper describes the design and dosimetry of an automated alpha-particle irradiator named 'BARC BioAlpha', which is suitable for in vitro radiobiological studies. Compared to alpha irradiators developed in other laboratories, BARC BioAlpha has integrated computer-controlled movement of the alpha-particle source, collimator, and electronic shutter. The diaphragm blades of the electronic shutter can control the area (diameter) of irradiation without any additional shielding, which is suitable for radiobiological bystander studies. To avoid irradiation with incorrect parameters, a software interlock is provided to prevent shutter opening, unless the user-specified speed of the source and collimator are achieved. The dosimetry of the alpha irradiator using CR-39 and silicon surface barrier detectors showed that ~4 MeV energy of the alpha particle reached the cells on the irradiation dish. The alpha irradiation was also demonstrated by the evaluation of DNA double-strand breaks in human cells. In conclusion, 'BARC BioAlpha' provides a user-friendly alpha irradiation system for radiobiological experiments with a novel automation mechanism for better accuracy of dose and exposure time.
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http://dx.doi.org/10.1615/jenvironpatholtoxicoloncol.2013009650DOI Listing
January 2014

Oxidative stress-mediated apoptotic death in human peripheral blood lymphocytes treated with plasma from gamma-irradiated blood.

J Environ Pathol Toxicol Oncol 2012 ;31(1):1-6

Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India.

The present study is aimed to investigate the effect of plasma from irradiated human blood on the induction of apoptotic death in human peripheral blood lymphocytes. Our results showed that plasma obtained from γ-irradiated human blood showed a significant decrease in viability and an increase in apoptotic death in unirradiated lymphocytes, which is correlated with increase in intracellular reactive oxygen species level. Moreover, a decrease in the activity of superoxide dismutase in lymphocytes further seems to be associated with oxidative stress-mediated apoptotic death. The diffusible factors from irradiated blood were found to be generated from the cellular components of blood. Based on our results, we suggest induction of oxidative stress-mediated apoptotic death in unirradiated lymphocytes by diffusible factors from irradiated blood.
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http://dx.doi.org/10.1615/jenvironpatholtoxicoloncol.v31.i1.10DOI Listing
July 2012