Technical note: Development of a feed matrix as inoculum in Salmonella infection studies in piglets.

Current methods used for oral administration of pathogens to piglets are stressful for the animals because of fixation and use of inoculation methods such as oral gavage. In the present study an alternative way to challenge piglets with Typhimurium (ST) is investigated. The strategy was to incorporate the in a feed matrix, which is fed to the piglets and eaten voluntary. Different types of feed matrices were tested for their absorption capacity, handling properties, and palatability to piglets. Furthermore, the viability of ST in feed matrices was studied. The ST could be incorporated in ladyfinger biscuits; a 2-cm piece absorbs 1 mL of culture media. The ladyfinger biscuits were very well accepted by the piglets. After a short training period, the piglets consumed the -incorporated biscuits out of the feeding trough. In this way the animals were infected in a more natural way and without stress. The safety of farm workers was also increased because the incorporated ST results in less spoilage and spreading of ST during the infections. Results indicated that the ST cell count was reduced by only 0.2 log unit to 8.7 log cfu per inoculum after 24 h at 4°C incorporation of ST into the biscuits, which is sufficient for an infection study and indicates excellent viability of the . The viability was also indicated by increased fecal shedding of ST. Thus, it is concluded that ladyfinger biscuits are a suitable matrix to challenge piglets with ST.

Human papillomavirus typing by single tube multiplex amplification in real time (SMART): the PapillomaFinder® SMART 20 assay.

BACKGROUND: High-risk (hr) human papillomavirus (HPV) infections play a causal role in the development of cervical cancer. The detection of hrHPV is, therefore, advocated in cervical cancer screening programs. OBJECTIVES: The aim of this study was to determine the performance of a novel HPV typing assay, PapillomaFinder® SMART 20. This is a one-tube-per-sample method, to be performed on standard real-time PCR platforms, using melting curve analysis to distinguish targets. The assay detects all 14 hrHPV types, of which 16, 18, 31, 33, 35, 39, 45, 52, 56 and 58 individually. HrHPV types 51, 59, 66 and 68 are detected in an hrHPV pool, and low-risk (lr) HPV types 6, 11, 40, 42, 43 and 44 in an lrHPV pool. STUDY DESIGN: The method was tested on HPV plasmid models, WHO and QCMD proficiency panels and a series of clinical cytological samples (n=45), the latter in comparison with a clinically validated real-time quantitative PCR. RESULTS: Type-specificity of the test was 100% using plasmids, the WHO and QCMD panels. Sensitivity for hrHPV in single infections was 100% using the WHO and QCMD panels and cytological samples, with an analytical sensitivity of 10-25 copies per reaction for all HPV types tested. Of the 34 HPV types present in the 8 multiple infections in the WHO panel, 30 were detected. In all cytological samples at least one hrHPV type was found, in concordance with the clinically validated method. Only when the viral load of the dominant HPV types in multiple infections greatly exceeded that of the other types in the infection, those other types were not always detected. CONCLUSIONS: PapillomaFinder® SMART 20 is a rapid, easy to perform, single tube HPV typing assay. The assay detects the 14 hrHPV types, and the 6 most important lrHPV types with a high sensitivity and type-specificity.

Stereoselective transformations on D-glucose-derived eight-membered ring carbocycles.

[structure: see text]. The cyclooctenol derivative 1 can be transformed into the nine-membered ring lactone 3, as well as the amino-containing carbocycles 4 and 5. The corresponding ketone 2 gives access to the conformationally locked azasugar 6.

Some comments on the paper by Edward S. Fry on the visible and near-ultraviolet absorption spectrum of liquid water.

It is contended that the most comprehensive collection of data on the visible and near-ultraviolet spectrum of pure liquid water can still be found [Appl. Opt. 38, 1216 (1999)]. The data produced [Appl. Opt. 36, 8710 (1997)] from the integrated light loss in a light-scattering cavity containing water produces a useful set of data, although the error bars presented are underestimated. Furthermore, an oxidative purification step was not incorporated into the water purification procedure to remove residual traces of light-absorbing organic impurities.

Visible and near-ultraviolet absorption spectrum of liquid water.

The optical absorption of pure liquid water in the 300-700-nm region has been measured by use of a long (1.5-m) path-length cell. The absorption spectrum coincides well with the edge of previous data in the 200-320-nm region and provides reliable data in the 320-420-nm region that has until now been a region of considerable unreliability. The data obtained for the 420-700-nm region agree quite well with the means of the existing literature in that well-studied region. The absorptions in the 550-700-nm region show evidence for the overtones and combination tones of the well-known OH stretching frequency at 3500 cm(-1).