Microbicide delivery: formulation technologies and strategies

Purpose of review: The aim of this article is to summarize the latest information on microbicide formulations for prevention of sexual transmission of HIV infection in women. Recent findings: Although early microbicide formulations were conventionally coitally dependent gel products, new technologies are being developed for vaginal delivery of anti-HIV agents. Intravaginal rings for delivery of microbicides, for example, are being developed and evaluated clinically. Safety and acceptability data are available for many microbicide gels and for one microbicide intravaginal ring. Other microbicide formulations in development for once daily or other vaginal administration strategies include films, tablets, and ovules. Various microbicide formulations for rectal administration are also in development. Summary: New microbicide formulations in development are addressing many of the issues with the original gels such as coital dependency, frequency of use, acceptability, compliance, cost, and adaptability to large-scale production. All of these dosage forms are promising options for safe, effective, and acceptable microbicide products.

Detection of synthetic glucocorticoid residues in cattle tissue and hair samples after a single dose administration using LC-MS/MS

A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the detection of several synthetic glucocorticoids in kidney, muscle and hair samples of cattle after a single intramuscular injection is described. After a dichloromethane wash of the hair samples, analytes were released from the hair matrix by enzymatic digestion. Muscle samples were also digested enzymatically using proteinase, while kidney samples were deconjugated by Helix pomatia juice. These preliminary steps were followed by a methanol extraction and a solid phase extraction (SPE) clean up step for all matrices. Chromatographic separation was achieved on a Hypersil Hypercarb column and MS/MS data were obtained in the multiple reaction monitoring mode using negative electrospray ionization. The developed protocols were evaluated by assessing residue concentrations in muscle, kidney and hair samples of thirteen calves, treated with a particular intramuscular injection of glucocorticoid. The lowest residue levels were found in muscle samples (approximately 5% of the residue levels in kidney), while high residue levels were obtained in hair samples. Hair is an interesting matrix since the sampling is non-invasive and the drugs may stay incorporated for a longer period of time. (C) 2004 Elsevier B.V. All rights reserved.

Characterisation of antibodies to chloramphenicol, produced in different species by enzyme-linked immunosorbent assay and biosensor technologies

Six polyclonal antisera to chloramphenicol (CAP) were successfully raised in camels, donkeys and goats. As a comparison of sensitivity, IC50 values ranged from 0.3 ng mL(-1) to 5.5 ng mL(-1) by enzyme-linked immunosorbent assay (ELISA) and from 0.7 ng mL(-1) to 1.7 ng mL(-1) by biosensor assay. The introduction of bovine milk extract improved the sensitivity of four of the antisera by ELISA and two by biosensor assay; a reduction in sensitivity of the remaining antisera ranged by a factor of 1.1-2.6. Porcine kidney extract reduced the sensitivity of all the antisera by a factor ranging from 1.1 to 7 by ELISA and a factor of 1.5 to 4 by biosensor. A low cross-reactivity with thiamphenicol (TAP) and florfenicol (FF) was displayed by antiserurn G2 (1.2% and 18%, respectively) when a homologous ELISA assay format was employed. No cross-reactivity was displayed by any of the antisera when a homologous biosensor assay format was employed. Switching to a heterologous ELISA format prompted three of the antisera to display more significant cross-reactivity with TAP and FF (53% and 82%, respectively, using Dl). The heterologous biosensor assay also increased the cross-reactivity of D1 for TAP and FF (56% and 129%, respectively) and of one other antiserum (Gl) to a lesser degree. However, unlike the ELISA, the heterologous biosensor assay produced a substantial reduction in sensitivity (by a factor of 6 for D1). (C) 2007 Elsevier B.V. All rights reserved.

Comparison of Image Transform-Based Features for Visual Speech Recognition in Clean and Corrupted Videos

We present results of a study into the performance of a variety of different image transform-based feature types for speaker-independent visual speech recognition of isolated digits. This includes the first reported use of features extracted using a discrete curvelet transform. The study will show a comparison of some methods for selecting features of each feature type and show the relative benefits of both static and dynamic visual features. The performance of the features will be tested on both clean video data and also video data corrupted in a variety of ways to assess each feature type's robustness to potential real-world conditions. One of the test conditions involves a novel form of video corruption we call jitter which simulates camera and/or head movement during recording.