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.
The present study describes the estimation of acetaminophen (AAP) toxicity in cultured rat hepatocytes. We used different concentrations of AAP - 1, 2. 5, 5, 10 and 20 mM, to test influence of AAP on cellular viability, functional capacity and oxidative status at given time intervals. WST-1 test showed decrease of dehydrogenase activity in 5, 10 and 20 mM AAP to 75 % of control values after 1 hour of incubation. At 12 h of treatment, all AAP concentrations decreased WST-1 signal; no enzyme activity was found since 18 h in cells treated with 20 mM AAP according to LDH leakage test performed at 24 h of incubation. Functional capacity was tested by albumin assay where the decrease was strictly related to AAP dose. Intracellular oxidative status was assessed by analysis of GSH/GSSG levels and time course of ROS production and glutathione reductase (GR) activity. Increased ROS prod uction was found already after 3 h of incubation in 2.5, 5, 10 and 20 mM AAP, respectively. The highest ROS production was measured after 12 h treatment. GR activity was decreased already after 3 h of incubation and remained also decreased in cells treated with 2.5, 5, 10 and 20 mM AAP during further incubation., Tomáš Roušar ... [et al.]., and Obsahuje seznam literatury
Perinatal hypoxia is still one of the greatest threats to the
newborn child, even in developed countries. However, there is
a lack of works which summarize up-to-date information about
that huge topic. Our review covers a broader spectrum of recent
results from studies on mechanisms leading to hypoxia-induced
injury. It also resumes possible primary causes and observed
behavioral outcomes of perinatal hypoxia. In this review, we
recognize two types of hypoxia, according to the localization of
its primary cause: environmental and placental. Later we analyze
possible pathways of prenatal hypoxia-induced injury including
gene expression changes, glutaminergic excitatory damage (and
a role of NMDA receptors in it), oxidative stress with ROS and
RNS production, inflammation and apoptosis. Moreover, we focus
on the impact of these pathophysiological changes on the
structure and development of the brain, especially on its regions:
corpus striatum and hippocampus. These brain changes of the
offspring lead to impairments in their postnatal growth and
sensorimotor development, and in their motor functions, activity,
emotionality and learning ability in adulthood. Later we compare
various animal models used to investigate the impact of prenatal
and postnatal injury (hypoxic, ischemic or combinatory) on living
organisms, and show their advantages and limitations.
Fatty liver disease associated with obesity is an important medical problem and the mechanisms for lipid accumulation in hepatocytes are not fully elucidated yet. Recent findings indicate that mitochondria play an importan t role in this process. Our data on hepatocytes in which mitochondria are in contact with other cytosolic structures importan t for their function, extend observations obtained on isolated mitochondria and confirm inhibition of Complex I activity in hepatocytes isolated from rats fed by high fat diet (HFD) compared with controls fed by standard diet (STD). Furthermore we have found that HFD- hepatocytes are more sensitive to the peroxidative stress because under these conditions also Complex II activity is disturbed. Therefore in HFD animals decrease of Complex I activity cannot be compensated by Complex II substrates as in STD hepatocytes. Our data thus indicates that combination of HFD and peroxidative stress potentiates HFD damaging effect of mitochondria because both branches of the respiratory chain (NADH- and flavoprotein-dependent) are disturbed., T. Garnol ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy