Interruption of long-term treatment with alpha 2-adrenergic receptor agonists may be associated with reversal of their hemodynamic effects, clinical and biochemical evidence of increased peripheral sympathetic activity, and behavioral responses similar to those seen after narcotic or alcohol withdrawal. Reactions are most commonly observed after short-acting imidazoline drugs such as clonidine and tiamenidine. Reactions are less common after longer acting agents such as guanfacine. A new management approach to withdrawal has been evaluated, which uses a combination of alpha 1-blockade (prazosin) and cardioselective beta-blockade (atenolol) together with a benzodiazepine (chlordiazepoxide). Withdrawal reactions were not observed in eight patients in whom clonidine was withdrawn under cover of these agents. The mechanism of the withdrawal reaction may involve agonist-induced down regulation of alpha 2-adrenergic receptor affinity, number, or both. Experimental studies with the irreversible alpha-antagonist phenoxybenzamine on the turnover of alpha 2-receptors suggest that recovery of receptor number may be much slower in the brain than in the periphery.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1161/01.hyp.6.5_pt_2.ii71 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Comparative performance of microscopy, rapid diagnostic tests, and multiplex real-time PCR for detection of malaria parasites among pregnant women in northwest Ethiopia.
Malar J
January 2025
Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
Background: Low malaria parasitaemia is a diagnostic challenge in pregnancy, leading to false negative microscopy and rapid diagnostic test (RDT) results. However, these submicroscopic or subpatent infections could cause adverse pregnancy outcomes. Thus, evaluating the diagnostic performance of microscopy, RDT, and multiplex qPCR in pregnancy is vital for informed decisions.
View Article and Find Full Text PDFLeveraging N- substituents to tune the donor/acceptor properties of mesoionic imines (MIIs).
Dalton Trans
January 2025
Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
In this work, we show two synthetic routes to substitute the N position of mesoionic imines (MIIs). By Buchwald-Hartwig amination, 5-amino-1,2,3-triazoles can be arylated at the said position, showing the versatility of amino-triazoles as building blocks for MIIs. The reaction of MIIs with electrophiles (MeI, fluoro-arenes) highlights the nucleophilic nature of MIIs as even at room temperature aromatic C-F bonds can be activated with MIIs.
View Article and Find Full Text PDFTransformative reactions in nitroarene chemistry: C-N bond cleavage, skeletal editing, and N-O bond utilization.
Org Biomol Chem
January 2025
Department of Applied Chemistry, Waseda University, 513 Wasedatsurumakicho, Shinjuku, Tokyo 162-0041, Japan.
Nitroarenes are highly versatile building blocks in organic synthesis, playing a pivotal role in various reactions. Common transformations involving nitroarenes include nucleophilic aromatic substitution (SAr) reactions, where the nitro group functions both as a potent electron-withdrawing group that activates the aromatic ring and as a leaving group facilitating the substitution. Additionally, the direct transformation of nitro groups, such as reduction-driven syntheses of amines and carboxylic acids, as well as -substitution SAr reactions, have been extensively explored.
View Article and Find Full Text PDFOptimization and DFT study for boosted electooxidation of formic acid at NiOx modified Pt using urea derivatives as blending fuels.
Sci Rep
January 2025
Department of Chemistry, Faculty of Science, Cairo University, Cairo, Egypt.
This paper addresses the enhancement of formic acid electrooxidation (FAO) at Pt and Pt-NiOx nanoparticles based-catalysts assisted with urea derivatives as blending fuels. Blending formic acid with various ratios of urea derivatives showed noticeable enhancements of FAO as demonstrated by a favorable negative shift of its onset potential (E) and increase of its peak current density concurrently with suppression of the amount of CO poisoning reaction intermediate. Among all the used derivatives, phenyl urea (PU) showed superior enhancing effect towards the direct FAO with a minimal CO formation together with a favorable negative shift of E by 150 mV.
View Article and Find Full Text PDFTailoring the surface and interface structures of carbon nitride for enhanced photocatalytic self-Fenton process in pollutant degradation.
J Colloid Interface Sci
January 2025
GuangDong Engineering Technology Research Center of Advanced Polymer Synthesis, Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, College of Chemistry and Chemical Engineering, Shantou University, Guangdong 515063 China. Electronic address:
Fenton technology faces significant challenges due to external HO dependency and inadequate Fe regeneration. Constructing a photocatalytic self-Fenton system is a promising strategy, but it is hindered by slow charge dynamics and low mass transfer of reactant ions. Here, we present a multi-engineering co-modified carbon nitride (OCN) for efficient photocatalytic self-Fenton reactions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!