The effect of 19-gauge endobronchial ultrasound-guided transbronchial needle aspiration biopsies on characterisation of malignant and benign disease. The Bristol experience.

EBUS-TBNA is a recent mediastinal staging and diagnostic technique. We have previously reported superior characterisation with 21G biopsies over 22G biopsies for benign and malignant mediastinal nodes. A new 19G needle now exists but there are limited studies. We hypothesised 19G biopsies would improve both benign and malignant characterisation due to larger samples. We retrospectively analysed sequential patients referred for EBUS-TBNA with unexplained mediastinal adenopathy performed with 19G, 21G and 22G needles respectively (100 patients each). Contingency table analysis was performed.  There were no complications. Sensitivity for malignancy was highest in the 19G group (95.7% versus 94.7% and 87.5%, respectively). The 19G group had higher mean lymph node size (19.4mm versus 18.6mm and 13.5mm, respectively), the highest proportion of lymphoma (9% versus 5% and 0%, respectively), the lowest proportion of NSCLC-NOS (2% versus 12% and 5%, respectively), the highest proportion of subcharacterised benign disease (89.6% versus 69.8% and 37.9%, respectively). This large single centre retrospective UK study suggests the 19G needle appears safe with the suggestion of better sensitivity for malignancy subcharacterisation of benign disease but this requires further study in adequately powered comparative controlled studies with univariate and multivariate analysis.

The scope of ambiphilic acetate-assisted cyclometallation with half-sandwich complexes of iridium, rhodium and ruthenium.

C−−H activation by acetate-assisted cyclometallation of a phenyl group with half-sandwich complexes [{MCl(2)Cp*}(2)] (M=Ir, Rh) and [{RuCl(2)-(p-cymene)}(2)] can be directed by a wide range of nitrogen donor ligands including pyrazole, oxazoline, oxime, imidazole and triazole, and X-ray structures of a number of complexes are reported. All the ligands tested cyclometallated at iridium, however ruthenium and rhodium fail to cause cyclometallation in some cases. As a result, the nitrogen donors have been categorised based on their reactivity with the three metals used. The relevance of these cyclometallation reactions to catalytic synthesis of carbocycles and heterocycles is discussed.

Alkyne insertion into cyclometallated pyrazole and imine complexes of iridium, rhodium and ruthenium; relevance to catalytic formation of carbo- and heterocycles.

The cyclometallated complexes [MCl(C^N)(ring)] (HC^N = 2-phenylpyrazole, M = Ir, Rh ring = Cp*; M = Ru, ring = p-cymene) readily undergo insertion reactions with RC≡CR (R = CO(2)Me, Ph) to give mono insertion products, the rhodium complex also reacts with PhC≡CH regiospecifically to give an analogous product. The products of the reactions of the cyclometallated imine complexes [MCl(C^N)Cp*] (HC^N = PhCH=NR, R = Ph, CH(2)CH(2)OMe, Me; M = Ir, Rh) with PhC≡CPh depend on the substituent R; when R = CH(2)CH(2)OMe a monoinsertion is observed, however for R = Me the initial insertion product is unstable, undergoing reductive elimination with loss of the organic fragment, and for R = Ph no metal-containing product is isolated. With PhC≡CH the cyclometallated imine complexes can give mono or di-insertion products. The implications for catalytic synthesis of carbo- and heterocycles by a tandem C-H activation, alkyne insertion mechanism are discussed.