The utility of lentivirus as a gene delivery vector in the cochlea was evaluated in vitro and in vivo. Lentivirus transduction was assessed through expression analysis of a reporter gene, green fluorescent protein (GFP), integrated within the viral genome. In vitro characterization of lentivirus-GFP was assessed by infection of explants from cochleas of neonatal rat. The lentiviral vector transduced both spiral ganglion neurons (SGNs) and glial cells. In vivo characterization of lentivirus-GFP was assessed by directly infusing the vector into the guinea pig cochlea via an osmotic minipump. Sections of lentivirus-infused cochlea revealed a highly restricted fluorescence pattern limited to the periphery of the perilymphatic space. Transduction of SGNs and glial cells by lentivirus in vitro but not in vivo suggests limited dissemination of the viral vector from the perilymphatic space. The cellular and tissue architecture of the lentivirus-infused cochlea was intact and free of inflammation. Restricted transduction of cell types confined to the periphery of the perilymphatic space by the lentivirus is ideal for stable production of gene products secreted into the perilymph.

No abstract

Keratosis obturans and external ear canal cholesteatomas have been considered as separate entities for the last 20 years, after being regarded as variations of the same disease for at least 87 years. While both disorders are distinct, they do have some overlapping characteristics which may make it difficult to reach a definite diagnosis. This review explores the diagnostic dilemmas which may arise, and discusses the classification, aetiology, pathogenesis and management of these conditions. We concur that external ear canal cholesteatoma and keratosis obturans are different conditions and conclude that the presence of osteonecrosis and focal overlying epithelial loss are the most reliable features favouring the diagnosis of external ear canal cholesteatoma over keratosis obturans. Furthermore, whilst keratosis obturans can be managed successfully by regular aural toilet, external ear canal cholesteatoma may require surgical intervention depending on the extent of the disease.

Textbook descriptions and illustrations of the opening of the sphenopalatine foramen (SPF) into the nasal cavity place it above and behind the posterior end of the middle turbinate (i.e., within the superior meatus). Although true for some skulls, this is not the situation for the majority and may be of importance, because the major blood supply to the nasal cavity enters via this route. Having studied 238 lateral nasal walls, the authors propose a classification of the osteology of the sphenopalatine foramen. In class I (35%) the opening of the SPF is purely into the superior meatus with a notch or foramen in the middle turbinate/ethmoidal crest of the palatine bone. In class II (56%) the SPF spans the ethmoidal crest (i.e., opens into both the superior and middle meati). In class III (9%) there are two separate openings into the superior and middle meati. These findings may explain the route of the artery to the inferior turbinate and indicate the need for care in dealing with the posterior end of the middle turbinate. They may also suggest a potential site for dealing with "difficult" epistaxis via an intranasal route.

Our ongoing evaluation of the results of laser assisted uvulopalatoplasty (LAUP) for snoring is presented. Follow-up between 18 and 24 months post-treatment completion, of patients with a successful result at six months, reveals that 22 per cent of these patients suffer failure of snoring control between these two evaluation points. This equates to an overall success rate at this time of 55 percent.LAUP, like other surgical remedies for snoring, has a continued relapse rate. This must be considered when counselling patients.