Microbicides 2004 Microbicides 200428-31 March 2004, Hilton London MetropoleThe conference42 million men, women and children worldwide were living with HIV by the end of December 2002 (source: UNAIDS), including five million newly-infected during that year alone. Another 45 million people will become infected between 2002 and 2010, unless the current transmission rates can be vastly reduced. Of the 42 million, 29.4 million live in sub-Saharan Africa and 58% of them are women. Not only are women more susceptible to HIV infection, many are powerless to insist on the use of condoms or other methods of protecting themselves. In this context, and with the knowledge that an effective HIV vaccine is unlikely to be available for several years, the need for an effective topical microbicide grows ever more urgent. 2004 should prove to be a landmark year in the field of microbicide development as the first Phase III trials of novel products are due to start – the next step along the road to making a microbicide available to the millions worldwide in desperate need of protection.The aims of the Microbicides 2004 conference are to:Report novel or innovative work in the microbicides fieldProvide updates on recent microbicides research, divided into three tracks: basic science, clinical science, and behavioural science (including public health and the microbicide marketplace)Provide a forum for the discussion of new developments in microbicide research including ethical, clinical, behavioural and methodological issuesPresent opportunities for knowledge-sharing between microbicide researchers, public-health workers and advocacy organisations.There will be an opening ceremony on the evening of Sunday 28 March at which politicians, policy makers and the international media are expected. The conference will run for a full three days, each of which will contain:Scientific overviews and presentations with plenary sessions, invited lecturers and presentations of original researchWorkshops to review issues unique to microbicides such as trial design and outcome measures, and ethical issues in the clinical trials of microbicidesPoster sessions. Focus on LondonFollowing the successful Microbicides conferences in Washington in 2000 and Antwerp in 2002, March 2004 sees the focus move to London.The venue is the Hilton Metropole Hotel, two minutes by taxi from Paddington station and the Heathrow Express, with a journey time from the airport of 15 minutes. The hotel is in walking distance of Hyde Park and London’s main shopping streets, and close to Imperial College. Accommodation will be available at the venue and other hotels in the vicinity.London in March offers a variety of diversions for out-of-conference relaxation, including sight-seeing and shopping; the arts and the theatre; and pubs, clubs and restaurants to suit every taste. Conference staff will be on hand to help delegates plan their spare time.To book your place or find out more information, e-mail info@microbicides2004.org.uk or telephone the Event Office on +44 (0) 20 7720 4411
Oral: invited speaker Oral: Track A Oral: Track B Oral: Track C Poster: Track A Poster: Track B Poster: Track C Abstract only Authors

02685 IMAGING THE DISTRIBUTION OF A RECTAL MICROBICIDE GEL AND SEMEN SURROGATE IN THE LOWER GI TRACT

Hendrix, Craig W.*
Fuchs E*, Macura K*, Guidos A*, Leal J*, Wahl R*
The Johns Hopkins University School of Medicine

Background: Understanding distribution of microbicide gel and HIV-infected semen within the rectum and lower gastrointestinal (GI) tract is critical to furthering the development of effective microbicides for rectal use. No data are available to describe this distribution, especially in the setting of coital behaviors that might notify distribution.

Objective: To evaluate the feasibility of imaging the distribution of a microbicide or semen surrogate using Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Magnetic Resonance Imaging (MRI) at baseline and 4 hours post-administration.

Study Design: A KY-Jelly-based microbicide surrogate or viscosity-matched semen surrogate, labelled with Gadolinium-DTPA (MRI contrast) and 500?Ci Technetium sulphur colloid (SPECT contrast), was administered to 3 subjects using 4 different experimental conditions. SPECT/CT and MR images were obtained immediately after simulated intercourse, and repeated 4 hours later.

Main Outcome Measure: Lower GI distribution of microbicide or semen surrogate over time.

Results: MR and SPECT/CT images of gel distribution initially localized to the rectum and sigmoid colon. 4 hours post–administration, the signal had migrated cephalad in 12/12 studies, with the most distant migration distributing to the splenic flexure (top of the descending colon).

Conclusion: SPECT/CT and MRI can be used to successfully determine the distribution of a microbicide or semen surrogate in the lower GI tract. Using the parameters for simulated coitus in our study, gel distribution was seen as far as the splenic flexure. MRI and SPECT/CT may be useful tools to study distribution and clearance of rectal microbicides and of HIV-infected semen to facilitate rational development of microbicides for rectal use.

Craig W. Hendrix, MD
Harvey 502, The Johns Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore, MD 21287-5554 USA
(Telephone) (410) 955-9707 (Fax) (410) 955-9708 (E-mail) chendrix@jhmi.edu