Moira Harrison

Growth factor protection against cytokine-induced apoptosis in neonatal rat islets of Langerhans: role of Fas

Treatment of neonatal rat islets of Langerhans with combined cytokines (interleukin‐1β 10−10 M, tumour necrosis factor‐α 10−10 M, interferon‐γ 5 U/ml) led to extensive cell death, which was potentiated by Fas activation with the anti‐Fas cytolytic antibody JO2. Pre‐treatment with insulin (25 ng/ml) or insulin‐like growth factor‐1 (10−8 M) gave only partial protection against cell killing, but prevented the Fas‐mediated component. In the absence of cytokine treatment, Fas‐mediated killing was not observed.

Pseudoislets as primary islet replacements for research : report on a symposium at King's College London, London UK

Laboratory-based research aimed at understanding processes regulating insulin secretion and mechanisms underlying β-cell dysfunction and loss in diabetes often makes use of rodents, as these processes are in many respects similar between rats/mice and humans. Indeed, a rough calculation suggests that islets have been isolated from as many as 150,000 rodents to generate the data contained within papers published in 2009 and the first four months of 2010. Rodent use for islet isolation has been mitigated, to a certain extent, by the availability of a variety of insulin-secreting cell lines that are used by researchers world-wide. However, when maintained as monolayers the cell lines do not replicate the robust, sustained secretory responses of primary islets which limits their usefulness as islet surrogates. On the other hand, there have been several reports that configuration of MIN6 β-cells, derived from a mouse insulinoma, as three-dimensional cell clusters termed ‘pseudoislets’ largely recapitulates the function of primary islet β-cells. The Diabetes Research Group at King’s College London has been using the MIN6 pseudoislet model for over a decade and they hosted a symposium on “Pseudoislets as primary islet replacements for research”, which was funded by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), in London on 15th and 16th April 2010. This small, focused meeting was conceived as an opportunity to consolidate information on experiences of working with pseudoislets between different UK labs, and to introduce the theory and practice of pseudoislet culture to laboratories working with islets and/or β-cell lines but who do not currently use pseudoislets. This short review summarizes the background to the development of the cell line-derived pseudoislet model, the key messages arising from the symposium and emerging themes for future pseudoislet research.

Opacification of SC60B-OUV lens implant following routine phacoemulsification surgery: case report and EM study

In 1949, Sir Harold Ridley implanted the first artificial intraocular lens (IOL) to reduce refractive error following cataract extraction.1 Numerous designs of IOL implants have followed and a variety of materials have been used in their manufacture, including poly(methyl methacrylate) (PMMA), silicone, acrylic, and hydrogel based materials. Important requirements of IOL implant material are to not excite an inflammatory response and the ability to remain transparent within the eye for an extended period of time. In recent years, there have been reports of opacification of IOL implants such as calcification on the optical surface of the Hydroview lens2; “glistenings” of fluid filled vacuoles in the optic of the AcrySof IOL3,4; and “snowflake” crystalline opacification of three piece rigid PMMA lenses.5 In particular, late postoperative opacification of a particular hydrophilic acrylic IOL, the SC60B-OUV, has been reported6 and analysis of these explanted IOLs have shown the presence of granular deposits within the optic.7 We report examination, using electron microscopy, of a similar explanted IOL removed following late postoperative opacification, which appears to have different surface morphology from those reported previously. An 82 year old female patient with Fuchs’ endothelial dystrophy underwent uneventful phacoemulsification and foldable lens implantation into the capsular bag of the left eye. Two weeks later, the best corrected …