Superelectrophilic Csp3-H bond fluorination of aliphatic amines in superacid: the striking role of ammonium-carbenium dications.

The superacid-promoted electrophilic Csp3-H bond activation of aliphatic amines generates superelectrophilic species that can be subsequently fluorinated. Demonstrated by low-temperature in situ NMR experiments, the ammonium-carbenium dications, crucial for this reaction, can also react with C-H bonds opening future synthesis perspectives for this mode of activation.

Diagnosis of isolated extensor carpi radialis longus (ECRL) tendon avulsion fracture using ultrasound: a paradigm shift.

Isolated avulsion fracture of the extensor carpi radialis longus (ECRL) tendon is a rare and poorly understood injury. We present a unique case of a 45-year-old male who fell on his flexed right hand. He presented with a subtle but extremely painful mass on the dorsum of his wrist. Ultrasound (U/S) imaging of the mass revealed an avulsed bone fragment attached to the ECRL tendon, confirming the clinical suspicion of an ECRL avulsion injury. Computed tomography and magnetic resonance imaging are well-documented imaging modalities to detect tendon avulsions. As demonstrated by this case report, U/S is an excellent diagnostic tool for ECRL rupture, a cost-effective alternative that provides real-time dynamic examination of hand injuries. To our knowledge, this is the first case of ECRL avulsion diagnosed by U/S. The purpose of this case report is to educate the reader on detection and diagnosis of ECRL tendon avulsion using U/S, a time-efficient and cost-effective imaging modality that is infrequently used for this purpose.

To reverse or not to reverse? A systematic review of autograft polarity on functional outcomes following peripheral nerve repair surgery.

BACKGROUND: The literature describing the best clinical practice for proximal-distal autograft orientation, otherwise known as nerve graft polarity, is inconsistent. With existing disparities in the peripheral nerve literature, the clinical question remains whether reversing nerve autograft polarity bears an advantage for nerve regeneration. METHODS: A comprehensive review of the literature using Embase and PubMed databases (1940-June 2015) was performed to retrieve all original articles on the effects of nerve autograft polarity on nerve regeneration and functional recovery following primary repair of peripheral nerve defects. RESULTS: The initial database search yielded 318 titles. Duplicate exclusion, title review and full text review yielded six articles which directly compared nerve autograft polarity. Histological, morphometric, electrophysiological, and behavioral outcomes were reviewed. All retained articles were animal studies, of which none demonstrated significant differences in outcomes between the normal and reversed polarity groups. A reversed graft may ensure that regenerating nerve fibers are not lost at branching points, however this may not translate into improved function. CONCLUSION: There is insufficient data to suggest that nerve autograft polarity has an impact on nerve regeneration and functional outcomes.

Catching elusive glycosyl cations in a condensed phase with HF/SbF5 superacid.

Glycosyl cations are universally accepted key ionic intermediates in the mechanism of glycosylation, the reaction that covalently links carbohydrates to other molecules. These ions have remained hypothetical species so far because of their extremely short life in organic media as a consequence of their very high reactivity. Here, we report the use of liquid hydrofluoric acid-antimony pentafluoride (HF/SbF5) superacid to generate and stabilize the glycosyl cations derived from peracetylated 2-deoxy and 2-bromoglucopyranose in a condensed phase. Their persistence in this superacid medium allows their three-dimensional structure to be studied by NMR, aided by complementary computations. Their deuteration further confirms the impact of the structure of the glycosyl cation on the stereochemical outcome of its trapping.

Synthetic deoxynojirimycin derivatives bearing a thiolated, fluorinated or unsaturated N-alkyl chain: identification of potent α-glucosidase and trehalase inhibitors as well as F508del-CFTR correctors.

The synthesis of eleven 1-deoxynojirimycin (DNJ) derivatives presenting either a monofluoro, difluoro, thiolated or unsaturated N-alkyl chain of various length is described. Exploiting the unsaturated moiety on the nitrogen, fluorine has been introduced through a HF/SbF5 superacid catalysed hydrofluorination and thiol-ene click chemistry allowed introduction of sulfur. The synthetic derivatives have been tested for their ability to inhibit glycosidases and correct F508del-CFTR. Two of the unsaturated iminosugars exhibited potency similar to Miglustat as F508del-CFTR correctors. The thioalkyl iminosugars as well as the corresponding alkyl iminosugars demonstrated low micromolar α-glucosidases and trehalases inhibition. Introduction of fluorine abolished F508del-CFTR correction and trehalase inhibition.

Open metacarpophalangeal dislocations: literature review and case report.

BACKGROUND: Open dorsal metacarpophalangeal joint dislocations are rare. We report the case of a 62-year-old man who fell from a height of 10 m onto his left outstretched hand and presented to us with four open dorsal metacarpophalangeal joint dislocations. We review the literature and present our case to elucidate the best treatment protocol for open dorsal metacarpophalangeal joint dislocations. METHODS: A systematic review was conducted using MEDLINE, Embase, and PubMed from 1946 to present. Publications were found using key terms and cross-referencing. Detail on patient demographic, presentation, mechanism of injury, injury management, and outcome were collected. RESULTS: A total of 102 articles of metacarpophalangeal joint dislocation (excluding thumb dislocations) were identified. Of these, only four were of open dorsal metacarpophalangeal joint dislocation involving the four long fingers. Open dislocation of the metacarpophalangeal joint in these studies showed no hand predominance, nor association with hand dominance. CONCLUSION: Open dorsal metacarpophalangeal joint dislocations of the four long fingers are unusual. Based on the available case reports and our experience, we suggest addressing this injury intraoperatively with minimal delay. Most cases will be associated with volar plate injury, and we encourage its repair with figure-of-eight stitches. Postoperatively, we suggest a dorsal blocking splint for 2 weeks followed by occupational therapy consisting of passive and active range of motion (ROM) exercises and adjunctive therapies to control edema and optimize scar tissue. Inadequate management of such injuries could be highly detrimental to hand function.

Evaluation of the Bronchorelaxant, Genotoxic, and Antigenotoxic Effects of Cassia alata L.

Aqueous-ethanolic extract of Cassia alata (AECal) and its derived fractions obtained through liquid-liquid fractionation were evaluated for their bronchorelaxant, genotoxic, and antigenotoxic effects. Contractile activity of rats' tracheas in the presence of tested materials, as well as its modifications with different inhibitors and blockers, was isometrically recorded. The antigenotoxic potential of AECal was evaluated on cyclophosphamide- (CP-) induced genotoxicity in the rat. Animals were pretreated with the extract, then liver comet assay was performed. AECal and its chloroformic fractions (CF-AECal) relaxed the contraction induced by Ach, but both were significantly less potent in inhibiting contraction induced by KCl (30 mM; 80 mM). Propranolol, indomethacin, L-NAME, methylene blue, and glibenclamide did not modify the relaxant effect of CF-AECal. TEA altered the response of trachea to CF-AECal. CF-AECal caused a rightward shift without affecting the E max in cumulative concentration-response curves of Ach only at low concentrations. In animals pretreated with the extract, the percentage of CP-induced DNA damage decreased. Our results suggest that (1) muscarinic receptors contribute at least in part to the relaxant effects of CF-AECal; (2) CF-AECal interferes with membrane polarization; and (3) AECal is not genotoxic in vivo and contains chemopreventive phytoconstituents offering protection against CP-induced genotoxicity.