Substitutions inSpodoptera exiguatopoisomerase I modulate its relaxation activity and camptothecin sensitivity

2016 ◽  
Vol 73 (6) ◽  
pp. 1179-1186 ◽  
Author(s):  
Pei Zhang ◽  
Lan Zhang ◽  
Yanning Zhang ◽  
Liangang Mao ◽  
Hongyun Jiang
Keyword(s):  
Relaxation Activity

Diphenethylpiperidine alkaloids with tracheal smooth muscle relaxation activity from Hippobroma longiflora (L.) G. Don

2019 ◽  
Vol 30 ◽  
pp. 93-98 ◽  
Author(s):  
Zi-Yang Chan ◽  
Kayatri Govindaraju ◽  
Premanand Krishnan ◽  
Yun-Yee Low ◽  
Kam-Weng Chong ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Relaxation ◽  
Tracheal Smooth Muscle ◽  
Smooth Muscle Relaxation ◽  
Relaxation Activity

Modulation of relaxation activity of human topoisomerases by Pt(II)-based complexes

2020 ◽  
Vol 211 ◽  
pp. 111178
Author(s):  
Odra Pinato ◽  
Anna Benettazzo ◽  
Lisa Dalla Via ◽  
Nicholas P. Farrell ◽  
Claudia Sissi
Keyword(s):  
Relaxation Activity

scholarly journals Biochemical Basis of E. coli Topoisomerase I Relaxation Activity Reduction by Nonenzymatic Lysine Acetylation

2018 ◽  
Vol 19 (5) ◽  
pp. 1439 ◽  
Author(s):  
Qingxuan Zhou ◽  
Mario Gomez Hernandez ◽  
Francisco Fernandez-Lima ◽  
Yuk-Ching Tse-Dinh
Keyword(s):  
Topoisomerase I ◽  
Lysine Acetylation ◽  
Biochemical Basis ◽  
E Coli ◽  
Relaxation Activity

scholarly journals RELAXATION ACTIVITY OF TETANUS (LEEA AEQUATA L.) LEAF ETHANOLIC EXTRACT ON GUINEA PIG ISOLATED TRACHEA

2018 ◽  
Vol 11 (13) ◽  
pp. 24 ◽  
Author(s):  
Nahitma Ginting ◽  
Edy Suwarso ◽  
Daud Vincen Rumapea ◽  
Nerdy Nerdy
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Stable Condition ◽  
Ethanolic Extract ◽  
Relaxation Effect ◽  
Atropine Sulfate ◽  
Relaxation Activity ◽  
Isolated Trachea ◽  
Acetylcholine Concentration

 Objective: The aim of this study is to determine the relaxation activity of the ethanolic extract of tetanus leaf (EETL) against contracting isolated guinea pig trachea induced by acetylcholine.Methods: Isolated trachea was equilibrated for 45 min until a stable condition in the Creb’s solution with a temperature of 37°C aerated with carbogen gas (O2:CO2=95%:5%). Test of the relaxation effect conducted after guinea pig trachea contracted with maximum acetylcholine concentration (EC80: 2.0449×10–3 mol) and then a cumulative with concentration of EETL (0.5 mg/mL–4 mg/mL) and concentration of atropine sulfate (6.95×10-6 mg/mL–2.08×10–2 mg/mL).Results: The results showed that EETL could lower the contraction smooth muscle of guinea pig trachea induced by acetylcholine. EETL at a concentration of 3.5 mg/mL had the ability to relax the muscle. It was not significantly different compared to that of atropine sulfate 6.95×10-3 mg/ mL (p>0.005).Conclusion: EETL has a relaxation effect on smooth muscle of guinea pig isolated trachea.

Searching for Affective and Cognitive Restoration: Examining the Restorative Effects of Casual Video Game Play

2017 ◽  
Vol 59 (7) ◽  
pp. 1096-1107 ◽  
Author(s):  
Michael A. Rupp ◽  
Richard Sweetman ◽  
Alejandra E. Sosa ◽  
Janan A. Smither ◽  
Daniel S. McConnell
Keyword(s):  
Cognitive Performance ◽  
Video Game ◽  
Digit Span ◽  
Leisure Activities ◽  
Vigilance Task ◽  
Future Research ◽  
Relaxation Techniques ◽  
Single Experiment ◽  
Relaxation Activity ◽  
Response To Stress

Objective: We investigated the effects of a passive break, relaxation activity, and casual video game on affect, stress, engagement, and cognitive performance. Background: Reducing stress and improving cognitive performance is critical across many domains. Previous studies investigated taking a break, relaxation techniques, or playing a game; however, these methods have not been compared within a single experiment. Method: Participants completed a baseline affective and cognitive assessment (ACA), which included the Positive and Negative Affect Schedule, shortened version of the Dundee Stress State Questionnaire, and backward digit-span. Next, participants completed a vigilance task, followed by another ACA. Participants were then assigned at random to complete a break or relaxation activity or play a casual video game, followed by a final ACA. Results: Participants who played the casual video game exhibited greater engagement and affective restoration than the relaxation condition. The break condition slightly decreased affect and prevented cognitive restoration. Conclusion: Playing a casual video game even briefly can restore individuals’ affective abilities, making it a suitable activity to restore mood in response to stress. However, future research is needed to find activities capable of cognitive restoration. Application: Many activities in life require sustained cognitive demand, which are stressful and decrease performance, especially for workers in performance-critical domains. Our research suggests some leisure activities are better than others for restoring fatigued affective processes.

scholarly journals Par-4 Binds to Topoisomerase 1 and Attenuates Its DNA Relaxation Activity

2008 ◽  
Vol 68 (15) ◽  
pp. 6190-6198 ◽  
Author(s):  
Anindya Goswami ◽  
Shirley Qiu ◽  
Thomas S. Dexheimer ◽  
Padhma Ranganathan ◽  
Ravshan Burikhanov ◽  
...  
Keyword(s):  
Relaxation Activity ◽  
Dna Relaxation ◽  
Topoisomerase 1

scholarly journals Comparative analysis of topoisomerase IB inhibition and DNA intercalation by flavonoids and similar compounds: structural determinates of activity

2004 ◽  
Vol 384 (3) ◽  
pp. 527-541 ◽  
Author(s):  
Michael R. WEBB ◽  
Susan E. EBELER
Keyword(s):  
Oxidative Degradation ◽  
Polyphenolic Compounds ◽  
Dna Intercalation ◽  
Clear Correlation ◽  
Acid Base ◽  
Relaxation Activity ◽  
Cellular Processes ◽  
Topoisomerase Inhibition ◽  
Topoisomerase Ib

Flavonoids and other polyphenolic compounds have been shown to inhibit human topoisomerase IB (topo I) through both inhibition of relaxation activity and through stabilization of the cleavable complex (poisoning). Some flavonoids have also been shown to intercalate DNA, and an association of topoisomerase inhibition with intercalation has been noted. We surveyed 34 polyphenolic compounds, primarily flavonoid glycones and aglycones, for their ability to inhibit topo I and to intercalate DNA using an in vitro gel electrophoresis method. We show that the most potent topo I poisons are the flavones and flavonols, and that these generally, but not always, are found to be DNA intercalators. There was no clear correlation, however, of topo-I-poisoning activity with the degree of DNA unwinding. Surprisingly, both DNA intercalation and topo I poisoning were shown to occur with some flavone glycones, including the C-glycosylflavone orientin. Inhibition of relaxation activity by flavonoids was found to be difficult to quantify and was most likely to be due to non-specific inhibition through flavonoid aggregation. As part of a structure–activity analysis, we also investigated the acid–base chemistry of flavonoids and determined that many flavonoids show acid–base activity with a pKa in the physiological pH region. For this reason, subtle pH changes can have significant effects on solution activity of flavonoids and their concomitant biological activity. In addition, these effects may be complicated by pH-dependent aggregation and oxidative degradation. Finally, we develop a simple model for the intercalation of flavonoids into DNA and discuss possible consequences of intercalation and topoisomerase inhibition on a number of cellular processes.

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