Evaluating futility of a binary clinical endpoint using early read-outs.

Interim analyses are routinely used to monitor accumulating data in clinical trials. When the objective of the interim analysis is to stop the trial if the trial is deemed futile, it must ideally be conducted as early as possible. In trials where the clinical endpoint of interest is only observed after a long follow-up, many enrolled patients may therefore have no information on the primary endpoint available at the time of the interim analysis. To facilitate earlier decision-making, one may incorporate early response data that are predictive for the primary endpoint (eg, an assessment of the primary endpoint at an earlier time) in the interim analysis. Most attention so far has been given to the development of interim test statistics that include such short-term endpoints, but not to decision procedures. Existing tests moreover perform poorly when the information is scarce, eg, due to rare events, when the cohort of patients with observed primary endpoint data is small, or when the short-term endpoint is a strong but imperfect predictor. In view of this, we develop an interim decision procedure based on the conditional power approach that utilizes the short-term and long-term binary endpoints in a framework that is expected to provide reliable inferences, even when the primary endpoint is only available for a few patients, and has the added advantage that it allows the use of historical information. The operational characteristics of the proposed procedure are evaluated for the phase III clinical trial that motivated this approach, using simulation studies

Transmission study of Salmonella in pigs with 3 intervention strategies

In this study, the effect of 3 different intervention strategies on the transmission of Salmonella in pigs was evaluated: feed supplementation with coated calcium-butyrate salt, vaccination and acidified drinking water. Strategies were evaluated serologically and bacteriologically using an experimental in vivo seeder setup. Significantly higher antibody titers were detected in the groups with acidified drinking water and vaccination

Steel fibre knitted fabric for automotive glass forming: variations of the fabric thickness on the mould and glass optical quality

Extremely fine steel fibres (12 mm diameter) are spun into yarns and then knitted into fabric, which is used, among other applications, as a mould cover in the formation of automotive glass. High requirements of the glass quality (absence of dioptric distortions) ask for a perfect evenness of the mould cover surface, which depends on the local distortions of the fabric created during tensioning of the fabric over the mould. In this paper, compression behaviour of steel knitted fabrics combined with the fabric deformation in biaxial tension and shear is studied. Interaction of the fabric with the formed glass depends on the local changes of the fabric compression behaviour due to local fabric deformations on the mould. The deformation of the fabric is further linked to quality of the glass using quantitative optical distortion system based on moire´ patterns to measure glass dioptric distortions.status: publishe

The role of botulinum toxin A in treating neurogenic bladder

Neurogenic detrusor overactivity (NDO) can result in lower and upper urinary tract complications and eventually even in end-stage kidney failure. Since the driving force of this clinical cascade is high bladder pressure, controlling intravesical pressure in NDO patients improves both quality of life and life-expectancy in these patients. Botulinum toxin A (BTX-A) has proven its efficacy in reducing intravesical pressure and in reducing incontinence episodes. BTX-A also improves quality of life in patients with NDO. Both onabotulinumtoxinA (Botox(®), Allergan, Irvine, USA) and abobotulinumtoxinA (Dysport(®), Ipsen, Paris, France) have a level A recommendation for NDO-treatment. The recommended dose for intradetrusor injections in NDO patients is 200 U of onabotulinumtoxinA or 500 U of abobotulinumtoxinA. The drug is generally administered extratrigonal in the detrusor muscle, via cystoscopic guided injection at 20 sites in 1 mL injections. Intradetrusor BTX-A injections are safe, with mostly local complications such as urinary tract infection and high post-void residual or retention. The effect of the toxin lasts for approximately 9 months. Repeat injections can be performed without loss of efficacy. Different injection techniques, novel ways of BTX-A administration, eliminating the need for injection or new BTX-A types with better/longer response rates could change the field in the future.status: publishe

Analytical profiling of Belgian Kriek beers

Fruit beers, appreciated worldwide, represent a small but rising segment in the Belgian beer export, amounting to a volume which should not be underestimated. This fruit beer ‘kriek’ is a school example of beer mixed drinks and originally kriek is produced by addition of fresh sour cherries to mid-young lambic beer (spontaneous fermentation). The traditional kriek beer is less fruity and more acid. As fresh sour cherries are limited available, and due to a trend towards sweeter beers, commercial kriek beers are nowadays often sweetened and prepared by use of cherry juice and aroma, which can be entirely or partly substituted by colourings and flavourings, resulting in a wide variety of fruit beers. Forced by the international trade and increasing competition with other beers, this study is to aim at a detailed characterisation of a number of kriek beers to bear mutual comparison or comparison with other beverages. Based on the resulting data matrix, great diversification is noticed between the commercial kriek beers investigated in this study. The characterisation of the Belgian kriek beers is performed by analytical flavour profiling, including higher alcohols, ethyl esters, acetate esters and aldehydes, by headspace solid phase microextraction in combination with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and by quantitative determination of the bittering profiles, organic acids and sugars by high pressure liquid chromatography.A clear classification of the beers, resulting in brand recognition, is obtained by application of principal component analysis (PCA) on the complex analytical data matrix.status: publishe

Experimental study of steel and glass knitted fabrics thickness under pre-strain and shear

The thickness of dry fabrics has big influence on the thickness of final composites. During the composite forming the fabrics are pre-strained, sheared and compressed so the thickness is changing. The paper describes an experimental procedure for derivation of the fabric thickness dependence on its deformation, using biaxial tension, shear and compression tests. The compression behaviour after different deformation modes is studied for glass and steel fibre knitted fabrics.status: publishe