The comet assay, or single-cell gel electrophoresis (SCGE), is
a sensitive, rapid, relatively simple and inexpensive method for
detecting DNA strand breaks in individual cells. It is used in
a broad variety of applications and as a tool to investigate DNA
damage and repair. The sensitivity and specificity of the assay
are greatly enhanced if the DNA incubated with an enzyme,
which recognizes a specific kind of DNA damage. This damage
induced by oxidative stress plays a pivotal role in many diseases
and in aging. This article is a critical review of the possible
application of the comet assay in some pathological states in
clinical practice. Most of the studies relate to evaluating the
response of an organism to chemotherapy or radiotherapy with
statistically significant evidence of DNA damage in patients. Other
useful applications have been demonstrated for patients with
heart or neurodegenerative diseases. Only a few studies have
been published on the use of this method in critically ill patients,
although its use would be appropriate. There are also other
scenarios where the comet assay could prove to be very useful in
the future, such as in predicting the likelihood of certain
pathological conditions.
Mechanical behavior of biological structures under dynamic loading generally depends on elastic as well as viscous properties of biological materials. The significance of “viscous” parameters in real situations remains to be elucidated. Behavior of rheological models consisting of a combination of inertial body and two Voigt’s bodies were described mathematically with respect to inverse problem solution, and behavior in impulse and harmonic loadings was analyzed. Samples of walls of porcine and human aorta thoracica in transverse direction and samples of human bone (caput femoris, substantia compacta) were measured. Deformation responses of human skin in vivo were also measured. Values of elastic moduli of porcine aorta walls were in the interval from 102 kPa to 103 kPa, values of viscous coefficients were in the interval from 102 Pa.s to 103 Pa.s. The value of shear stress moduli of human caput femoris, substantia compacta range from 52.7 to 161.1 MPa, and viscous coefficients were in the interval from 27.3 to 98.9 kPa.s. The role of viscous coefficients is significant for relatively high loading frequencies - in our materials above 8 Hz in aorta walls and 5 Hz for bones. In bones, the viscosity reduced maximum deformation corresponding to short rectangular stress., M. Kuchařová, S. Ďoubal, P. Klemera, P. Rejchrt, M. Navrátil., and Obsahuje bibliografii