生物分析および生物医学ジャーナル

Exposure to reactive oxygen species can result in formation of oxidized nucleotides which increase the frequency of mutations, DNA damage, and cell death. MutT Homolog 1 (MTH1) is an enzyme that catalyzes removal of pyrophosphate from the highly mutagenic oxidized nucleoside triphosphate 8-oxo-2'-deoxyguanosine-5'-triphosphate (8-oxo-dGTP). Interest in MTH1 as a potential new target for cancer therapy surged due to reports of MTH1 inhibitors causing DNA damage and inducing cell death in cancer cells. However, questions have been raised about MTH1 target validation. One critical piece of information that is currently lacking is a quantitative understanding of the levels of 8-oxo-dGTP in cancer cells and the effect of MTH1 inhibition on them. In this study, we developed a sensitive and selective method to simultaneously measure the intracellular concentrations of 8-oxo guanosine nucleotides and their unmodified counterparts using liquid chromatography coupled to tandem mass spectrometry (LC-MS/ MS). An ion-pairing reversed phase liquid chromatography method using dimethylhexylamine was employed to quantify the highly polar analytes. The method was validated fit for purpose using a combination of authentic standards and cell samples. The intracellular oxo-nucleotide concentrations in human bone osteosarcoma cell line U2OS were determined using the method. We observed very low levels of 8-oxo nucleotides in untreated and hydrogen peroxide treated cells and MTH1 knockdown in these cells had minimal if any effect on 8-oxo nucleotide levels. This method will allow for a more comprehensive understanding of oxidized nucleotide detoxification pathways and MTH1 as a target for cancer therapy.

Epilepsy, once thought to be a disease of evil spirit, is now believed by many as a common neurologic condition that can be effectively treated by optimal use of anti seizure drugs. Despite the availability of multiple and cost effective medications, people with epilepsy could experience episodes of seizures. Aim of the present study was to assess the treatment outcome and associated factors among adult epileptic patients at Hawassa University Specialized Hospital (HUSH), Ethiopia. A cross sectional study was conducted on randomly selected adult epileptic patients. Univariable and multivariable logistic regression analyses were performed to identify factors associated with treatment outcome. Total of 255 patients were included. of whom, 38% had a poorly controlled seizures. Having no formal education [Adjusted Odds Ratio [(AOR): 2.71, 95% Confidence Interval (CI):1.35 -5.46], spending only a year on Anti Seizure Drugs (ASDs) [Adjusted Odds Ratio [(AOR): 4.90, 95% Confidence Interval (CI):1.37-17.50] and low adherence to ASDs [Adjusted Odds Ratio [(AOR): 2.04, 95% Confidence Interval (CI):1.04-4.04] were associated with uncontrolled seizure. Significantly higher epileptic patients had uncontrolled seizure. Epileptic patients with no formal education, who spent a short time on medication and those who have a low medication adherence, were more likely to have uncontrolled seizure. Therefore, more emphasis should be given to these patients.