Abdominal twitches due to ICD lead dislodgement; A case report.

Malfunctions of implantable cardiac devices have the potential to be catastrophic. A 63-year-old patient was admitted to our emergency department with new-onset abdominal pain and sensation of twitching on his abdominal wall. One month ago, an implantable cardioverter-defibrillator (ICD) was implanted in him to prevent malignant ventricular arrhythmias.

Targeting Using Arylboronate/Nopoldiol Click Conjugation.

Bioorthogonal click reactions yielding stable and irreversible adducts are in high demand for applications, including in biomolecular labeling, diagnostic imaging, and drug delivery. Previously, we reported a novel bioorthogonal "click" reaction based on the coupling of ortho-acetyl arylboronates and thiosemicarbazide-functionalized nopoldiol. We now report that a detailed structural analysis of the arylboronate/nopoldiol adduct by X-ray crystallography and B NMR reveals that the bioorthogonal reactants form, unexpectedly, a tetracyclic adduct through the cyclization of the distal nitrogen into the semithiocarbazone leading to a strong B-N dative bond and two new 5-membered rings.

Boronic Acids as Bioorthogonal Probes for Site-Selective Labeling of Proteins.

Over the past two decades, bioorthogonal chemistry has become a preferred tool to achieve site-selective modifications of proteins. However, there are only a handful of commonly applied bioorthogonal reactions and they display some limitations, such as slow rates, use of unstable or cytotoxic reagents, and side reactions. Hence, there is significant interest in expanding the bioorthogonal chemistry toolbox.

Synergic "Click" Boronate/Thiosemicarbazone System for Fast and Irreversible Bioorthogonal Conjugation in Live Cells.

Fast, high-yielding, and selective bioorthogonal "click" reactions employing nontoxic reagents are in high demand for their great utility in the conjugation of biomolecules in live cells. Although a number of click reactions were developed for this purpose, many are associated with drawbacks and limitations that justify the development of alternative systems for both single- or dual-labeling applications. Recent reports have highlighted the potential of boronic ester formation as a bioorthogonal click reaction between abiotic boronic acids and diols.

Fast and Tight Boronate Formation for Click Bioorthogonal Conjugation.

A new click bioorthogonal reaction system was devised to enable the fast ligation (k(ON) ≈340 m(-1)  s(-1)) of conjugatable derivatives of a rigid cyclic diol (nopoldiol) and a carefully optimized boronic acid partner, 2-methyl-5-carboxymethylphenylboronic acid. Using NMR and fluorescence spectroscopy studies, the corresponding boronates were found to form reversibly within minutes at low micromolar concentration in water, providing submicromolar equilibrium constant (K(eq) ≈10(5) -10(6) m(-1)). Efficient protein conjugation under physiological conditions was demonstrated with model proteins thioredoxin and albumin, and characterized by mass spectrometry and gel electrophoresis.