741 research outputs found
Effect of isoflurane and sevoflurane on the magnitude and time course of neuromuscular block produced by vecuronium, pancuronium and atracurium
Cyclodextrins and the emergence of sugammadex
Summary Residual paralysis, with its subsequent postoperative pulmonary sequelae, is one of the major complications of anaesthesia, and was recognised shortly after the introduction of neuromuscular blocking drugs into routine clinical practice. Although its incidence decreased with the introduction of intermediate duration drugs, and further diminished with routine neuromuscular monitoring and reversal with cholinesterase inhibitors, residual paralysis still remained a problem. In the search for alternatives to stop the effect of neuromuscular blocking drugs and to match their duration of action to clinical need, chelation of the non-depolarising neuromuscular blocking drugs was considered. It was recognised that cyclodextrins could encapsulate steroidal molecules and thereby inactivate the aminosteroidal neuromuscular blocking drugs. In order to improve the binding of rocuronium to the cyclodextrin and to increase the compound's water solubility
Activation of sp3-CH Bonds in a Mono(pentamethylcyclopentadienyl)yttrium Complex. X-ray Crystal Structures and Dynamic Behavior of Cp*Y(o-C6H4CH2NMe2)2 and Cp*Y[o-C6H4CH2NMe(CH2-μ)][μ-o-C6H4CH2NMe(CH2-μ)]YCp*[THF]
Reaction of Y(o-C6H4CH2NMe2)3 (1) with Cp*H gives Cp*Y(o-C6H4CH2NMe2)2 (2), which crystallizes in the monoclinic space group P21/n (No. 14) with a = 18.607 (4) Å, b = 15.633 (3) Å, c = 8.861 (3) Å, β = 102.73 (3)°, and Z = 4. Least-squares refinement with 3006 independent reflections (F > 4.0σ(F)) led to a final RF (wR) of 0.053 (0.068). The molecular structure consists of monomeric Cp*Y(o-C6H4CH2NMe2)2 units with a regularly bonded Cp* ligand (Y-Ct = 2.367 (3) Å), equal Y-C(aryl) distances (2.479 (6) and 2.471 (6) Å), and both nitrogen atoms coordinated to yttrium (Y-N distances = 2.568 (5) and 2.506 (6) Å). Short intramolecular Y···H distances (Y···H(181) = 3.00 (6) Å, Y···H(183) = 3.13 (9) Å) indicate agostic interactions. The long N(2)-C(18) bond (1.55 (1) Å) and the short Y···C(18) distance (3.202 (8) Å) indicate an Y···C-N agostic interaction. Thermolysis of 2 in THF gives Cp*Y[o-C6H4CH2NMe(CH2-μ)][μ-o-C6H4CH2NMe(CH2-μ)]YCp*[THF] (3) and N,N-dimethylbenzylamine. Compound 3 crystallizes in the monoclinic space group P21/c (No. 14) with a = 17.004 (1) Å, b = 13.962 (1) Å, c = 20.129 (3) Å, β = 92.94 (1)°, and Z = 4. Least-squares refinement with 4578 independent reflections (F > 5.0σ(F)) led to a final RF (wR) of 0.065 (0.070). The molecule consists of two Cp*Y fragments (Y(1)-Ct(1) = 2.420 (6) Å, Y(2)-Ct(2) = 2.414 (5) Å), bridged by two methylene carbon atoms (Y(1)-C(9) = 2.591 (10) Å, Y(2)-C(9) = 2.527 (9) Å, Y(1)-C(18) = 2.622 (10) Å, Y(2)-C(18) = 2.532 (10) Å) and one aryl carbon atom (Y(1)-C(1) = 2.702 (8) Å, Y(2)-C(1) = 2.547 (9) Å). The remaining aryl group is not bridging (Y(1)-C(10) = 2.441 (8) Å). Asymmetry in 3 is caused by THF coordination (Y(2)-O = 2.446 (5) Å). Thermolysis of 2 can be explained by dissociation of an Y-N dative bond followed by activation of an agostic C-H bond
Dose-dependent effects of the selective serotonin reuptake inhibitor citalopram:A combined SPECT and phMRI study
AMPT-induced monoamine depletion in humans: evaluation of two alternative [123I]IBZM SPECT procedures
Purpose
Acute monoamine depletion paradigms using alpha-methyl-para-tyrosine (AMPT) combined with single photon emission computed tomography (SPECT) have been used successfully to evaluate disturbances in central dopaminergic neurotransmission. However, severe side effects due to relatively high doses (4,500 to 8,000 mg) of AMPT have been reasons for study withdrawal. Thus, we assessed the effectiveness and tolerability of two alternative procedures, using lower doses of AMPT.
Methods
Six healthy subjects underwent three measurements of striatal dopamine D2 receptor (D2R)-binding potential (BPND) with SPECT and the selective radiolabeled D2R antagonist [123I]IBZM. All subjects were scanned in the absence of pharmacological intervention (baseline) and after two different depletion procedures. In the first depletion session, over 6 h, subjects were administered 1,500 mg of AMPT before scanning. In the second depletion session, over 25 h, subjects were administered 40 mg AMPT/kg body weight. We also administered the Subjective Well-being Under Neuroleptic Treatment Scale, a self-report instrument designed to measure the subjective experience of patients on neuroleptic medication.
Results
We found no change of mean D2R BPND after the first and short AMPT challenge compared to the baseline. However, we found a significant increase in striatal D2R BPND binding after the AMPT challenge adjusted for bodyweight compared to both other regimen. Although subjective well-being worsened after the prolonged AMPT challenge, no severe side effects were reported.
Conclusions
Our results imply a low-dosage, suitable alternative to the common AMPT procedure. The probability of side effects and study withdrawal can be reduced by this procedure
Affective regulation of cognitive-control adjustments in remitted depressive patients after acute tryptophan depletion
Negative affect in healthy populations regulates the appraisal of demanding situations, which tunes subsequent effort mobilization and adjustments in cognitive control. In the present study, we hypothesized that dysphoria in depressed individuals similarly modulates this adaptation, possibly through a neural mechanism involving serotonergic regulation. We tested the effect of dysphoria induced by acute tryptophan depletion (ATD) in remitted depressed patients on conflict adaptation in a Simon task. ATD temporarily lowers the availability of the serotonin precursor L-Tryptophan and is known to increase depressive symptoms in approximately half of remitted depressed participants. We found that depressive symptoms induced by ATD were associated with increased conflict adaptation. Our finding extends recent observations implying an important role of affect in regulating conflict-driven cognitive control
The Neuroscience of Sadness: A Multidisciplinary Synthesis and Collaborative Review for the Human Affectome Project
Sadness is typically characterized by raised inner eyebrows, lowered corners of the mouth, reduced walking speed, and slumped posture. Ancient subcortical circuitry provides a neuroanatomical foundation, extending from dorsal periaqueductal grey to subgenual anterior cingulate, the latter of which is now a treatment target in disorders of sadness. Electrophysiological studies further emphasize a role for reduced left relative to right frontal asymmetry in sadness, underpinning interest in the transcranial stimulation of left dorsolateral prefrontal cortex as an antidepressant target. Neuroimaging studies – including meta-analyses – indicate that sadness is associated with reduced cortical activation, which may contribute to reduced parasympathetic inhibitory control over medullary cardioacceleratory circuits. Reduced cardiac control may – in part – contribute to epidemiological reports of reduced life expectancy in affective disorders, effects equivalent to heavy smoking. We suggest that the field may be moving toward a theoretical consensus, in which different models relating to basic emotion theory and psychological constructionism may be considered as complementary, working at different levels of the phylogenetic hierarchy
Rapid Eye Movement Sleep Behavior Disorder:Abnormal Cardiac Image and Progressive Abnormal Metabolic Brain Pattern
BACKGROUND: Isolated rapid eye movement sleep behavior disorder (iRBD) is prodromal for α-synucleinopathies. OBJECTIVE: The aim of this study was to determine whether pathological cardiac [123 I]meta-iodobenzylguanidine scintigraphy ([123 I]MIBG) is associated with progression of [18 F]fluorodeoxyglucose-positron emission tomography-based Parkinson's disease (PD)-related brain pattern (PDRP) expression in iRBD. METHODS: Seventeen subjects with iRBD underwent [18 F]fluorodeoxyglucose-positron emission tomography brain imaging twice ~3.6 years apart. In addition, [123 I]MIBG and [123 I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane single-photon emission computed tomography ([123 I]FP-CIT-SPECT) at baseline were performed. Olfactory, cognitive, and motor functions were tested annually. RESULTS: Twelve of 17 subjects had pathological [123 I]MIBG. At baseline, 6 of 12 of these expressed the PDRP (suprathreshold PDRP z score). At follow-up, 12 of 17 subjects had suprathreshold PDRP z scores, associated with pathological [123 I]MIBG in 92% and with pathological [123 I]FP-CIT-SPECT in 75%. Subjects with pathological [123 I]MIBG had higher PDRP z score change per year (P = 0.027). Three subjects phenoconverted to PD; all had pathological [123 I]MIBG and [123 I]FP-CIT-SPECT, suprathreshold baseline PDRP z scores, and hyposmia. CONCLUSIONS: Pathological [123 I]MIBG was associated with progressive and suprathreshold PDRP z scores at follow-up. Abnormal [123 I]MIBG likely identifies iRBD as prodromal PD earlier than pathological [123 I]FP-CIT-SPECT. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
Personalized versus standard cognitive behavioral therapy for fear of cancer recurrence, depressive symptoms or cancer-related fatigue in cancer survivors:Study protocol of a randomized controlled trial (MAtCH-study)
© 2021, The Author(s).Background: Fear of cancer recurrence, depressive symptoms, and cancer-related fatigue are prevalent symptoms among cancer survivors, adversely affecting patients’ quality of life and daily functioning. Effect sizes of interventions targeting these symptoms are mostly small to medium. Personalizing treatment is assumed to improve efficacy. However, thus far the empirical support for this approach is lacking. The aim of this study is to investigate if systematically personalized cognitive behavioral therapy is more efficacious than standard cognitive behavioral therapy in cancer survivors with moderate to severe fear of cancer recurrence, depressive symptoms, and/or cancer-related fatigue. Methods: The study is designed as a non-blinded, multicenter randomized controlled trial with two treatment arms (ratio 1:1): (a) systematically personalized cognitive behavioral therapy and (b) standard cognitive behavioral therapy. In the standard treatment arm, patients receive an evidence-based diagnosis-specific treatment protocol for fear of cancer recurrence, depressive symptoms, or cancer-related fatigue. In the second arm, treatment is personalized on four dimensions: (a) the allocation of treatment modules based on ecological momentary assessments, (b) treatment delivery, (c) patients’ needs regarding the symptom for which they want to receive treatment, and (d) treatment duration. In total, 190 cancer survivors who experience one or more of the targeted symptoms and ended their medical treatment with curative intent at least 6 months to a maximum of 5 years ago will be included. Primary outcome is limitations in daily functioning. Secondary outcomes are level of fear of cancer recurrence, depressive symptoms, fatigue severity, quality of life, goal attainment, therapist time, and drop-out rates. Participants are assessed at baseline (T0), and after 6 months (T1) and 12 months (T2). Discussion: To our knowledge, this is the first randomized controlled trial comparing the efficacy of personalized cognitive behavioral therapy to standard cognitive behavioral therapy in cancer survivors. The study has several innovative characteristics, among which is the personalization of interventions on several dimensions. If proven effective, the results of this study provide a first step in developing an evidence-based framework for personalizing therapies in a systematic and replicable way. Trial registration: The Dutch Trial Register (NTR) NL7481 (NTR7723). Registered on 24 January 2019
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