Post by Max on Oct 21, 2005 3:10:14 GMT -5
Significantly elevated 8-OHdG in human subjects exposed to (Ro)accutane - highly likely one of the relevant markers for (Ro)accutane induced oxidative DNA damage
High serum levels of 8-OHdG in acne-subjects exposed to isotretinoine may be due to a direct effect on liver, muscle and skin epidermal cells. Regular evaluation of 8-OHdG in sera of patients, especially of exposed women of reproductive age, could be a sensitive follow-up biomarker of DNA oxidation [1]. In the rat-brain, elevated 8-OHdG is a suggested marker for oxidative stress and correlated with degenerative changes [2].
Human subjects with CA (n=18) were evaluated before and 45 days after Iso (0.5mg/kg per day) exposure and non-diseased controls (n=22) were tested only once. Plasma TAS levels and 8-OHdG were measured spectrophotometrically and with an immunoassay, respectively. Liver biochemical parameters and muscle enzymes were measured on a blood chemistry analyzer. Results: TAS levels were significantly (p<0.0001) lower in patients before treatment (921+/-124 mumol/L) compared with those after treatment (1335+/-93 mumol/L) and in controls (1536+/-126 mumol/L). In contrast, 8-OHdG serum levels were two-fold higher in patients after exposure (0.21+/-0.03 ng/mL) than before exposure (0.11+/-0.02 ng/mL) and three-fold higher than in controls (0.07+/-0.01 ng/mL; p<0.0001). Negative correlations were found between TAS and 8-OHdG (r=-0.754, p<0.0001) in patients before therapy and positive correlations were found between creatine kinase (CK) and 8-OHdG (r=0.488, p<0.001) and liver enzymes after isotretinoine exposure [1].
Significantly elevated 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative stress in the brain of rats exposed to arsenic
To clarify the association between oxidative DNA damage and the neurotoxicity of arsenic, the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative DNA damage in the brain was examined in mice fed with drinking water containing 1 or 2 ppm arsenic, using an HPLC-electrochemical detector and immunohistochemical method. 8-OHdG levels were significantly increased in the brain of mice given arsenic and its immunoreactivity was distributed in the cerebral and cerebellar cortexes. Cerebral cortex neurons and Purkinje cells in the cerebellar cortex showed degenerative changes in accordance with the distribution of 8-OHdG immunoreactivity. The levels of arsenic in this study were lower than those reported in epidemiological studies. Thus, it is concluded that environmentally relevant levels of arsenic induce pathological changes through oxidative DNA damage in the brain tissues in vivo and that cerebral and cerebellar cortex neurons seem to be the major targets of arsenic neurotoxicity [2].
High serum levels of 8-OHdG in acne-subjects exposed to isotretinoine may be due to a direct effect on liver, muscle and skin epidermal cells. Regular evaluation of 8-OHdG in sera of patients, especially of exposed women of reproductive age, could be a sensitive follow-up biomarker of DNA oxidation [1]. In the rat-brain, elevated 8-OHdG is a suggested marker for oxidative stress and correlated with degenerative changes [2].
Human subjects with CA (n=18) were evaluated before and 45 days after Iso (0.5mg/kg per day) exposure and non-diseased controls (n=22) were tested only once. Plasma TAS levels and 8-OHdG were measured spectrophotometrically and with an immunoassay, respectively. Liver biochemical parameters and muscle enzymes were measured on a blood chemistry analyzer. Results: TAS levels were significantly (p<0.0001) lower in patients before treatment (921+/-124 mumol/L) compared with those after treatment (1335+/-93 mumol/L) and in controls (1536+/-126 mumol/L). In contrast, 8-OHdG serum levels were two-fold higher in patients after exposure (0.21+/-0.03 ng/mL) than before exposure (0.11+/-0.02 ng/mL) and three-fold higher than in controls (0.07+/-0.01 ng/mL; p<0.0001). Negative correlations were found between TAS and 8-OHdG (r=-0.754, p<0.0001) in patients before therapy and positive correlations were found between creatine kinase (CK) and 8-OHdG (r=0.488, p<0.001) and liver enzymes after isotretinoine exposure [1].
Significantly elevated 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative stress in the brain of rats exposed to arsenic
To clarify the association between oxidative DNA damage and the neurotoxicity of arsenic, the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative DNA damage in the brain was examined in mice fed with drinking water containing 1 or 2 ppm arsenic, using an HPLC-electrochemical detector and immunohistochemical method. 8-OHdG levels were significantly increased in the brain of mice given arsenic and its immunoreactivity was distributed in the cerebral and cerebellar cortexes. Cerebral cortex neurons and Purkinje cells in the cerebellar cortex showed degenerative changes in accordance with the distribution of 8-OHdG immunoreactivity. The levels of arsenic in this study were lower than those reported in epidemiological studies. Thus, it is concluded that environmentally relevant levels of arsenic induce pathological changes through oxidative DNA damage in the brain tissues in vivo and that cerebral and cerebellar cortex neurons seem to be the major targets of arsenic neurotoxicity [2].