Sepideh Mahinrousta, Heidar Sharafi, Seyed Moayed Alavian, Bita Behnava, Ali Pouryasin,
Volume 15, Issue 7 (December 2012)
Abstract
Background: Nucleos(t)ide analogues, such as lamivudine and adefovir, are effective drugs for treatment of hepatitis B patients. However, long-term treatment with these drugs leads to the emergence of the nucleos(t)ide analogue resistant strains. The impact of nucleos(t)ide analogues on the emergence of HBsAg escape mutations is not clarified. Hence, the aim of this study was to determine HBsAg escape mutations in chronic hepatitis B patients treated with nucleos(t)ide analogues. Materials and Methods:A cross-sectional study was performed on 50 patients with chronic hepatitis B under treatment with nucleos(t)ide analogues (lamivudine and/or adefovir) and 50 naive chronic hepatitis B patients. HBV DNA was extracted from plasma and S gene of virus was amplified by Nested-PCR followed by direct sequencing. HBsAg gene sequence of the samples was evaluated for detection of HBsAg escape mutations. Results: Among the 100 patients, the following HBsAg escape mutations were identified: sQ101H, sG119R, sP120S, sP127S, sA128V, sG130N, sG130R, sT131I, sM133I, and sY134N. The frequency of HBsAg escape mutations in patients under treatment of nucleos(t)ide analogues was 16% and in naïve patients was 6% (p=0.2, OR=2.98). Conclusion:According to the obtained results, there seems to be no association between using nucleos(t)ide analogues and emergence of HBsAg escape mutations.
Firoozeh Alavian, Sohrab Hajizadeh, Mohammad Javan, Roham Mazloom,
Volume 20, Issue 6 (9-2017)
Abstract
Abstract
Background: Recent studies indicate that hyperoxia has a significant therapeutic effect in the acute ischemic injury. The role of intracellular kinases, including ERK, has been posed in the phenomenon of ischemic tolerance. In the present study, the effect of intermittent normobaric hyperoxia on the activity of ERK in the stroke model was studied
Material and Methods: This is an experimental study. Animals include 4 groups (sham, hyperoxia–sham, stroke and hyperoxia–stroke); each group consisted of 6 male Wistar rats in the weight range of 250 to 350 grams. Hyperoxia groups were exposed to 95% inspired oxygen for 4 h/day and 6 consecutive days. Oxygen concentration in the control groups was 21% (normoxia, room air). After 24h, the stroke group animals were subjected to 60 min of right middle cerebral artery occlusion (MCAO). After 24h reperfusion, neurological deficit scores (NDS) and ERK activity were assessed.
Results: 5 hours after MCAO, stroke groups showed a significant increase in ERK activity in the cortex (p <0.01) and subcortex (p <0.001). At the same time, hyperoxia significantly increased the activity of ERK in cortex compared to the normoxia group (p<0.05). In subcortex, hyperoxia had no significant effect on ERK activity. Twenty-four hours after MCAO, stroke groups showed a significant reduction in ERK activity in the cortex (p <0.001) and subcortex (p <0.05). 24hr after MCAO, The activity of ERK in the hyperoxia groups; in both cortex and subcortex areas was significantly higher than that of the normoxia groups (p<0.05). Also, hyperoxia caused a significant decrease in NDS (p=0.0220).
Conclusion: Increased levels of ERK activity in the hyperoxia groups can be used to protect the nervous system, but the presence of other malicious factors may have been more effective in some cases, so that hyperoxia alone hasn’t been able to prevent stroke progression.
