38 research outputs found
Ketamine as an Alternative Anesthetic for Augmenting Seizure Durations During Electroconvulsive Therapy : A Retrospective Observational Study
Objective:
Electroconvulsive therapy (ECT) is highly effective for severe psychiatric disorders; however, short seizure durations may lead to ineffective therapy. This retrospective study aimed to examine the risks and benefits of switching to ketamine anesthesia to augment seizure durations during an acute course of ECT.
Methods:
We included 33 patients who underwent ketamine anesthesia due to suboptimal seizures during an acute course of ECT. We assessed seizure duration, stimulus dose, hemodynamic variability, and post-seizure complications before and after switching to ketamine.
Results:
Age was significantly associated with suboptimal seizures during ECT (p = 0.040). After switching to ketamine, 32 patients (97%) experienced prolonged seizure duration. Ketamine significantly prolonged both electroencephalogram and motor seizure durations with a mean difference of 34.6 s (95% CI, 26.4 to 42.7; p < 0.001) and 26.6 s (95% CI, 19.6 to 33.6; p < 0.001), respectively. It also significantly reduced stimulus dose (mean difference: −209.5 mC [95% CI, −244.9 to −174.1], p < 0.001). Additionally, maximum changes in systolic blood pressure and heart rate during ECT sessions significantly increased with ketamine (mean difference: 27.2 mmHg [95% CI, 12.0 to 42.4; p = 0.001]; 25.7 bpm [95% CI, 14.5 to 36.8; p < 0.001], respectively). Patients reported more headaches with ketamine (p = 0.041).
Conclusions:
Our results provide evidence that ketamine as an alternative anesthetic can augment seizure durations in specific patients experiencing suboptimal seizures during an acute course of ECT. However, its use requires greater attention to circulatory management and post-seizure complications
Fluorescence modulation by fast photochromism of a [2.2]paracyclophane-bridged imidazole dimer possessing a perylene bisimide moiety
© 2018 The Royal Society of Chemistry. The development of single-molecule imaging and super-resolution microscopy techniques has promoted the study of fluorescence switchable molecules that have been important for the in-depth understanding of the activities of organelles and the geometries of materials in the nano- and microscale. The utilization of photochromic compounds as the photo-switching trigger is an efficient strategy to reversibly control the fluorescent "ON" and "OFF" states. In this study, we demonstrated the red-color fluorescence switching of a perylene bisimide (PBI) derivative by using a fast photochromic [2.2]paracyclophane-bridged imidazole dimer. The transient colored biradical species as the fluorescence quencher is generated upon UV light irradiation. Because the biradical species has broad absorption bands in the whole visible light and the near-infrared regions (500-900 nm), the fluorescence of PBI could be efficiently quenched by Förster resonance energy transfer (FRET). The fluorescence intensity was switched by means of fast photochromic cycles within a few tens of milliseconds. The potential capability of the transient biradical species to switch the fluorescence in the visible and NIR regions will open up new possibilities in multicolor fluorescence imaging.status: publishe
Rapid Fluorescence Switching by Using a Fast Photochromic [2.2]Paracyclophane-Bridged Imidazole Dimer
Recently, we have developed a series
of fast photochromic imidazole
dimers with a [2.2]Âparacyclophane ([2.2]ÂPC) moiety that bridge diphenylimidazole
units and succeeded the acceleration of the thermal decoloration rate.
The colorless [2.2]ÂPC-bridged imidazole dimers show a photoinduced
homolytic bond cleavage of the C–N bond between the imidazole
rings to give a pair of colored imidazolyl radicals upon UV light
irradiation, followed by the radical–radical coupling reaction
to form the initial C–N bond between the imidazole rings. The
decoloration reaction to give the initial imidazole dimer proceeds
only thermally. The high quantum yield close to unity of the photochromic
reaction and the large extinction coefficient of the radical achieve
both high optical density at the photostationary state and rapid switching
speed. The application to rapid fluorescence switching has been investigated
to develop a new type of photochromic fluorescence switching molecule
applicable to super-resolution microscopy. The widespread absorption
of the colored radical lying between 500 and 900 nm enables the efficient
quenching of the excited electronic state of the fluorophores by Förster
resonance energy transfer (FRET) from the fluorophores to the radical
moiety. We successfully developed a [2.2]ÂPC-bridged imidazole dimer
possessing a fluorescein
moiety as a fluorescence unit. This photochromic dye shows fast photochromism
to give a pair of imidazolyl radicals that quench the fluorescence
from the fluorescent unit by the FRET mechanism. The fluorescence
intensity can be switched rapidly with the fast photochromism
Rapid Fluorescence Switching by Using a Fast Photochromic [2.2]Paracyclophane-Bridged Imidazole Dimer
Recently, we have developed a series
of fast photochromic imidazole
dimers with a [2.2]Âparacyclophane ([2.2]ÂPC) moiety that bridge diphenylimidazole
units and succeeded the acceleration of the thermal decoloration rate.
The colorless [2.2]ÂPC-bridged imidazole dimers show a photoinduced
homolytic bond cleavage of the C–N bond between the imidazole
rings to give a pair of colored imidazolyl radicals upon UV light
irradiation, followed by the radical–radical coupling reaction
to form the initial C–N bond between the imidazole rings. The
decoloration reaction to give the initial imidazole dimer proceeds
only thermally. The high quantum yield close to unity of the photochromic
reaction and the large extinction coefficient of the radical achieve
both high optical density at the photostationary state and rapid switching
speed. The application to rapid fluorescence switching has been investigated
to develop a new type of photochromic fluorescence switching molecule
applicable to super-resolution microscopy. The widespread absorption
of the colored radical lying between 500 and 900 nm enables the efficient
quenching of the excited electronic state of the fluorophores by Förster
resonance energy transfer (FRET) from the fluorophores to the radical
moiety. We successfully developed a [2.2]ÂPC-bridged imidazole dimer
possessing a fluorescein
moiety as a fluorescence unit. This photochromic dye shows fast photochromism
to give a pair of imidazolyl radicals that quench the fluorescence
from the fluorescent unit by the FRET mechanism. The fluorescence
intensity can be switched rapidly with the fast photochromism
The Safety and Strategies for Reinitiating Electroconvulsive Therapy (ECT) After ECT-Induced Takotsubo Cardiomyopathy : A Case Report and Systematic Review
Objectives:
Takotsubo cardiomyopathy (TCM) is a life-threatening complication of electroconvulsive therapy (ECT). We report the case of a 66-year-old woman who was re-challenged with ECT after ECT-induced TCM. Moreover, we have made a systematic review to assess the safety of and strategies for re-initiating ECT after TCM.
Methods:
We searched for published reports on ECT-induced TCM since 1990 in MEDLINE (PubMed), Scopus, Cochrane Library, ICHUSHI, and CiNii Research.
Results:
A total of 24 ECT-induced TCM cases were identified. Patients who developed ECT-induced TCM were predominantly middle-aged and older women. There was no specific trend in anesthetic agents used. Seventeen (70.8%) cases developed TCM by the third session in the acute ECT course. Eight (33.3%) cases developed ECT-induced TCM despite the use of β-blockers. Ten (41.7%) cases developed cardiogenic shock or abnormal vital signs related to cardiogenic shock. All cases recovered from TCM. Eight (33.3%) cases tried to receive ECT retrial. The duration until ECT retrial was between 3 weeks and 9 months. The most common preventive measures during ECT retrial were related to β-blockers; however, the type, dose, and route of administration of β-blockers varied. In all cases, ECT could be re-performed without TCM recurrence.
Conclusions:
ECT-induced TCM is more likely to cause cardiogenic shock than non-perioperative cases; nevertheless, it has good prognosis. Cautious re-initiation of ECT after TCM recovery is possible. Further studies are required to determine preventive measures for ECT-induced TCM
Fast Photochromism Involving Thermally-Activated Valence Isomerization of Phenoxyl-Imidazolyl Radical Complex Derivatives
Open-shell
biradicals have received considerable attention in material
science because of their high two-photon absorption cross sections
and broad and high absorptive features over the visible region. However,
the instability of the biradical caused by the open-shell nature was
one of the drawbacks; therefore, novel radical compounds which can
suppress unwanted reactions by tuning the open-shell features are
desired to expand the versatility of the radical compounds. Here,
we report a novel radical-dissociation-type photochromic compound
whose photochromic reaction involves a valence isomerization from
the open-shell biradical to closed-shell quinoidal forms by using
a phenoxyl-imidazolyl radical complex framework. The valence isomerization
from the biradical to quinoid forms effectively tunes the open-shell
feature in time and drastically changes the spectral features, which
were revealed by time-resolved Fourier transform infrared spectroscopy.
This novel fast photochromic property not only is important for fundamental
spin chemistry but also expands the versatility of the radical compounds
for novel advanced photofunctional materials
Electrochemistry of Photochromic [2.2]Paracyclophane-Bridged Imidazole Dimers: Rational Understanding of the Electronic Structures
[2.2]ÂParacyclophane-bridged
imidazole dimers, which show unique
fast photochromism, have various practical applications in industry.
To put them to practical use, it is necessary to prepare various types
of the imidazole dimers which have different color, reaction rate,
sensitivity, etc. One of the simple methods for modulating the optical
properties is to add substituents and sensitizers. However, it is
difficult to estimate the highest occupied molecular orbital (HOMO)
and lowest unoccupied molecular orbital (LUMO) levels of the imidazole
dimers by optical spectroscopy because the LUMO of the imidazole dimers
are optically inactive. In the present study, we applied electrochemistry
and density functional theory to reveal the effect of substituents
on the electronic states of the imidazole dimers. We revealed that
the HOMO and LUMO of the imidazole dimers are localized over only
one of the imidazole rings of the imidazole dimer. By comparing the
measured LUMO energies of the imidazole dimers and calculated LUMO
energies of several visible sensitizers, we found which visible sensitizers
work in the imidazole dimer systems. These fundamental insights provide
useful information for understanding the electronic structures of
the imidazole dimers and give a strategy for designing novel fast
photochromic molecules whose photochromism is triggered by visible
light
Fast Photochromism Involving Thermally-Activated Valence Isomerization of Phenoxyl-Imidazolyl Radical Complex Derivatives
Open-shell
biradicals have received considerable attention in material
science because of their high two-photon absorption cross sections
and broad and high absorptive features over the visible region. However,
the instability of the biradical caused by the open-shell nature was
one of the drawbacks; therefore, novel radical compounds which can
suppress unwanted reactions by tuning the open-shell features are
desired to expand the versatility of the radical compounds. Here,
we report a novel radical-dissociation-type photochromic compound
whose photochromic reaction involves a valence isomerization from
the open-shell biradical to closed-shell quinoidal forms by using
a phenoxyl-imidazolyl radical complex framework. The valence isomerization
from the biradical to quinoid forms effectively tunes the open-shell
feature in time and drastically changes the spectral features, which
were revealed by time-resolved Fourier transform infrared spectroscopy.
This novel fast photochromic property not only is important for fundamental
spin chemistry but also expands the versatility of the radical compounds
for novel advanced photofunctional materials
Fast Photochromism Involving Thermally-Activated Valence Isomerization of Phenoxyl-Imidazolyl Radical Complex Derivatives
Open-shell
biradicals have received considerable attention in material
science because of their high two-photon absorption cross sections
and broad and high absorptive features over the visible region. However,
the instability of the biradical caused by the open-shell nature was
one of the drawbacks; therefore, novel radical compounds which can
suppress unwanted reactions by tuning the open-shell features are
desired to expand the versatility of the radical compounds. Here,
we report a novel radical-dissociation-type photochromic compound
whose photochromic reaction involves a valence isomerization from
the open-shell biradical to closed-shell quinoidal forms by using
a phenoxyl-imidazolyl radical complex framework. The valence isomerization
from the biradical to quinoid forms effectively tunes the open-shell
feature in time and drastically changes the spectral features, which
were revealed by time-resolved Fourier transform infrared spectroscopy.
This novel fast photochromic property not only is important for fundamental
spin chemistry but also expands the versatility of the radical compounds
for novel advanced photofunctional materials