A foreign body is a rare cause of parotid gland obstructive sialadenitis; intra-oral penetration via Stensen's duct is unusual. The relatively recent introduction of interventional sialendoscopy to treat obstructive sialadenitis has allowed surgeons to adopt a gland-sparing approach by means of miniaturised endoscopes and instruments. However, unusual anatomy or pathological conditions can give rise to a risk of intraductal rupture that may lead to a subsequent iatrogenic foreign body.

This paper describes the case of a patient with a 4 mm stone engaged by a broken wire basket stuck in a secondary branch of Stensen's duct.

The iatrogenic foreign body was successfully retrieved by means of sialendoscopy-assisted transfacial surgery.

This is the first reported case of an intraductal rupture of a miniaturised device during interventional sialendoscopy successfully resolved by means of combined endoscopy and external surgery. This proved to be an effective method of rescuing a foreign body stuck in Stensen's duct.

The GluN2B subunit of N-methyl-d-aspartate receptors is crucially involved in the physiology of the prefrontal cortex during working memory (WM). Consistently, genetic variants in the GluN2B coding gene (GRIN2B) have been associated with cognitive phenotypes. However, it is unclear how GRIN2B genetic variation affects gene expression and prefrontal cognitive processing. Using a composite score, we tested the combined effect of GRIN2B variants on prefrontal activity during WM performance in healthy subjects.

We computed a composite score to combine the effects of single nucleotide polymorphisms on post-mortem prefrontal GRIN2B mRNA expression. We then computed the composite score in independent samples of healthy participants in a peripheral blood expression study (n = 46), in a WM behavioural study (n = 116) and in a WM functional magnetic resonance imaging study (n = 122).

Five polymorphisms were associated with GRIN2B expression: rs2160517, rs219931, rs11055792, rs17833967 and rs12814951 (all corrected p < 0.05). The score computed to account for their combined effect reliably indexed gene expression. GRIN2B composite score correlated negatively with intelligence quotient, WM behavioural efficiency and dorsolateral prefrontal cortex activity. Moreover, there was a non-linear association between GRIN2B genetic score and prefrontal activity, i.e. both high and low putative genetic score levels were associated with high blood oxygen level-dependent signals in the prefrontal cortex.

Multiple genetic variants in GRIN2B are jointly associated with gene expression, prefrontal function and behaviour during WM. These results support the role of GRIN2B genetic variants in WM prefrontal activity in human adults.

It has been suggested that bacterial biofilms may be a causative factor in the aetiopathogenesis of chronic tonsillitis. Involvement of exhaled nitric oxide has been previously considered, with conflicting findings.

A pilot study was performed to investigate the relationship between exhaled nitric oxide levels and the presence of tonsillar biofilm-producing bacteria in children with chronic tonsillitis.

Tonsillar biofilm-producing bacteria on bioptic specimens taken during tonsillectomy were assessed by means of spectrophotometry.

Analysis was based on 24 children aged 5–10 years (median, 7.5 years). Biofilm-producing bacteria were found in 40.9 per cent of specimens. The median exhaled nitric oxide level was 11.6 ppb (range, 3.2–22.3 ppb). There was a significant relationship between the presence of biofilm-producing bacteria and increased exhaled nitric oxide levels (p = 0.03). Children with exhaled nitric oxide levels of more than 8 ppb were at three times greater risk of developing tonsillar biofilm-producing bacteria than those with lower levels.

Our findings suggest the possibility of discriminating children with chronic biofilm-sustained tonsillar infections on the basis of exhaled nitric oxide levels.