26 research outputs found
Catalytic Asymmetric Spirocyclizing DielsâAlder Reactions of Enones: Stereoselective Total and Formal Syntheses of α-Chamigrene, ÎČ-Chamigrene, Laurencenone C, Colletoic Acid, and Omphalic Acid
We disclose a general catalytic enantioselective DielsâAlder reaction of exo-enones with dienes to give spirocyclanes. The obtained products feature highly congested quaternary stereogenic spirocenters and are used in concise total and formal syntheses of several sesquiterpenes, including of α-chamigrene, ÎČ-chamigrene, laurencenone C, colletoic acid, and omphalic acid. The stereo- and regioselectivities of our spirocyclizing cycloaddition are effectively controlled by strongly acidic and confined imidodiphosphorimidate catalysts. Computational studies shed light on the origin of reactivity and selectivity
Anterior cingulate gamma-aminobutyric acid concentrations and electroconvulsive therapy
Objective
The anticonvulsant hypothesis posits that ECTâs mechanism of action is related to enhancement of endogenous anticonvulsant brain mechanisms. Results of prior studies investigating the role of the inhibitory neurotransmitter gammaâaminobutyric acid (âGABA+â, GABA and coedited macromolecules) in the pathophysiology and treatment of depression remain inconclusive. The aim of our study was to investigate treatmentâresponsive changes of GABA+ in subjects with a depressive episode receiving electroconvulsive therapy (ECT).
Methods
In total, 41 depressed subjects (DEP) and 35 healthy controls (HC) were recruited at two independent sites in Norway and the USA. MEGAâPRESS was used for investigation of GABA+ in the anterior cingulate cortex. We assessed longitudinal and crossâsectional differences between DEP and HC, as well as the relationship between GABA+ change and change in depression severity and number of ECTs. We also assessed longitudinal differences in cognitive performance and GABA+ levels.
Results
Depressive episode did not show a difference in GABA+ relative to HC (t71 = â0.36, p = .72) or in longitudinal analysis (t36 = 0.97, p = .34). Remitters and nonremitters did not show longitudinal (t36 = 1.12, p = .27) or crossâsectional differences in GABA+. GABA+ levels were not related to changes in antidepressant response (t35 = 1.12, p = .27) or treatment number (t36 = 0.05, p = .96). An association between cognitive performance and GABA+ levels was found in DEP that completed cognitive effortful testing (t18 = 2.4, p = .03).
Conclusion
Our results failed to support GABA as a marker for depression and abnormal mood state and provide no support for the anticonvulsant hypothesis of ECT. ECTâinduced change in GABA concentrations may be related to change in cognitive function.publishedVersio
Analysis of lipase activity in duodenal juice. Comparison of an automated spectrophotometric assay to a fluorometric microplate assay, and factors affecting sample stability
Fire Performance of Timber Connections, Part 1: Fire Resistance Tests on Bolted Wood-Steel-Wood and Steel-Wood-Steel Connections
Telemonitoring of vital signs has a minor impact on clinical decision making but well-being improves in patients with chronic heart failure.
Anterior cingulate gamma-aminobutyric acid concentrations and electroconvulsive therapy
Objective
The anticonvulsant hypothesis posits that ECTâs mechanism of action is related to enhancement of endogenous anticonvulsant brain mechanisms. Results of prior studies investigating the role of the inhibitory neurotransmitter gammaâaminobutyric acid (âGABA+â, GABA and coedited macromolecules) in the pathophysiology and treatment of depression remain inconclusive. The aim of our study was to investigate treatmentâresponsive changes of GABA+ in subjects with a depressive episode receiving electroconvulsive therapy (ECT).
Methods
In total, 41 depressed subjects (DEP) and 35 healthy controls (HC) were recruited at two independent sites in Norway and the USA. MEGAâPRESS was used for investigation of GABA+ in the anterior cingulate cortex. We assessed longitudinal and crossâsectional differences between DEP and HC, as well as the relationship between GABA+ change and change in depression severity and number of ECTs. We also assessed longitudinal differences in cognitive performance and GABA+ levels.
Results
Depressive episode did not show a difference in GABA+ relative to HC (t71 = â0.36, p = .72) or in longitudinal analysis (t36 = 0.97, p = .34). Remitters and nonremitters did not show longitudinal (t36 = 1.12, p = .27) or crossâsectional differences in GABA+. GABA+ levels were not related to changes in antidepressant response (t35 = 1.12, p = .27) or treatment number (t36 = 0.05, p = .96). An association between cognitive performance and GABA+ levels was found in DEP that completed cognitive effortful testing (t18 = 2.4, p = .03).
Conclusion
Our results failed to support GABA as a marker for depression and abnormal mood state and provide no support for the anticonvulsant hypothesis of ECT. ECTâinduced change in GABA concentrations may be related to change in cognitive function