Upconversion fluorescence resonance energy transfer in a homogeneous immunoassay for estradiol

We recently described a novel homogeneous assay principle based on upconversion fluorescence resonance energy transfer (UC-FRET), where an upconverting phosphor (UCP) is utilized as a donor. The UC-FRET has now been applied to a competitive homogeneous immunoassay for 17beta-estradiol (E2) in serum, using a small-molecular dye as an acceptor. The assay was constructed by employing an UCP coated with an E2-specific recombinant antibody Fab fragment as a donor and an E2-conjugated small-molecular dye, Oyster-556, as an acceptor. Standard curves for the assay were produced both in buffer and in male serum. Sensitized acceptor emission was measured at 600 nm under continuous laser diode excitation at 980 nm. In buffer, the IC50 value of the assay was 1 nM and in serum 3 nM. The lower limits of detection (mean of zero calibrators, 3 SD) were 0.4 and 0.9 nM, respectively. The measurable concentration range extended up to 3 nM in buffer and 9 nM in serum. Equilibrium in the assay was reached in 30 min. The novel principle of UC-FRET has unique advantages compared to present homogeneous luminescence-based methods and can enable an attractive assay system platform for clinical diagnostics and for high-throughput screening approaches.     

Recent Advances in Intracellular and In Vivo ROS Sensing: Focus on Nanoparticle and Nanotube Applications

Reactive oxygen species (ROS) are increasingly being implicated in the regulation of cellular signaling cascades. Intracellular ROS fluxes are associated with cellular function ranging from proliferation to cell death. Moreover, the importance of subtle, spatio-temporal shifts in ROS during localized cellular signaling events is being realized. Understanding the biochemical nature of the ROS involved will enhance our knowledge of redox-signaling. An ideal intracellular sensor should therefore resolve real-time, localized ROS changes, be highly sensitive to physiologically relevant shifts in ROS and provide specificity towards a particular molecule. For in vivo applications issues such as bioavailability of the probe, tissue penetrance of the signal and signal-to-noise ratio also need to be considered. In the past researchers have heavily relied on the use of ROS-sensitive fluorescent probes and, more recently, genetically engineered ROS sensors. However, there is a great need to improve on current methods to address the above issues. Recently, the field of molecular sensing and imaging has begun to take advantage of the unique physico-chemical properties of nanoparticles and nanotubes. Here we discuss the recent advances in the use of these nanostructures as alternative platforms for ROS sensing, with particular emphasis on intracellular and in vivo ROS detection and quantification.     

In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteria

A range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary fibre carbohydrates β‐glucan, xylan, xylo‐oligosaccharides (XOS) and arabinoxylan. β‐Glucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bifidobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bifidobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also efficiently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium difficile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bifidobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C difficile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations. © 2002 Society of Chemical Industry     

Excimer laser photorefractive keratectomy for hyperopia

Sixty consecutive patients with the obstructive sleep apnoea syndrome (53 men and seven women) were analysed by questionnaire, polysomnography, r?ntgenographic cephalometry and the Mueller manoeuvre before and 6 months after uvulopalatopharyngoplasty (UPPP), to assess the surgical outcome and the prognostic value of preoperative evaluation. Seventy-three per cent of patients reported improvement of snoring and 55% reported improvement of excessive daytime sleepiness. Thirty-five per cent showed a decrease of at least 50% in the desaturation index, and 13% had a postoperative desaturation index below 5. Although the improvement of desaturation parameters was marked in some patients, the overall change was not significant. Neither the Body Mass Index (BMI), nor any of the cephalometric variables were significantly correlated to surgical outcome. Increased difference in collapsibility between the soft palate and the base of the tongue showed a close to significant relation with the improvement of desaturation index. High desaturation index, low mean saturation and deep lowest saturation were found to be slightly predictive of improvement in nocturnal desaturation. In a multivariate analysis however no significant predictors could be identified. It is concluded that UPPP is effective in reducing snoring and daytime sleepiness over a 6-month follow-up period, but that the overall improvement in nocturnal desaturation is limited and difficult to predict. Further research is needed to evaluate the long-term efficacy of UPPP.     

Assessing children's competence: Mothers' and teachers' ratings of competent behavior.

The purposes of this study were to test the replicability of the factor structure of the Health Resources Inventory (HRI; E. L. Gesten [see PA, Vol 57:7209]) for teachers, to describe the factor organization of the HRI when used with parents, and to assess the strength of agreement between parents' and teachers' views of children's competence. Parents' ratings were available for 269 children (ages 4 to 12 years), and teachers' ratings were gathered for a subset of 102. Analysis of teachers' responses confirmed a 5-factor structure of the HRI. The factor structure for mothers closely mirrored that of teachers. The similarity of factor structure argues for the usefulness of the HRI in assessing children's competence at home and school. The relatively modest correlation between mothers' and teachers' ratings suggests possible setting differences in children's behavior and/or variance related to rater source. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol beverage drinking, diet and body mass index in a cross-sectional survey

OBJECTIVE: The study was carried out to determine the associations of alcohol beverage drinking with macronutrients, antioxidants, and body mass index. SETTING: Dietary subsample of the 1992 Finmonica cardiovascular risk factor survey in Finland; a cross-sectional study. SUBJECTS: 985 women and 863 men were drawn from the population register in the four monitoring areas. All subjects were 25-64 y of age. METHODS: The mailed questionnaire included questions covering socioeconomic factors, physical activity, smoking, and alcohol consumption. The diet was assessed using a three-day food record. RESULTS: The dietary differences between abstainers and alcohol consumers were more significant than between consumers of different alcoholic beverages. Among drinkers, fat intake as a percentage of energy was higher and carbohydrate intake was lower than among abstainers. Those who preferred wine, however, had the highest vitamin C intake; female wine drinkers also had the highest carotenoid intake. With the exception of those who mainly preferred spirits, alcohol energy was not added to the diet but seemed to substitute food items both in men and women. Despite the similar total daily energy intakes, daily energy expenditure, and physical activity index, male drinkers were leaner than abstainers. In women, the proportion of underreporters of energy intake increased with increasing alcohol consumption, and the association between alcohol and body mass index was similar to that in men after the exclusion of underreporters. CONCLUSIONS: Alcohol consumers were leaner than abstainers, and wine drinkers in particular had more antioxidants in their diet.     

Ontogeny and Environment as Determinants of the Secondary Chemistry of Three Species of White Birch

This study investigates variation in the secondary chemistry of the bark of three closely related, winter-dormant species of white birch (Betula resinifera, B. pendula, and B. platyphylla) at different ontogenetic stages by using different plant parts (top and base). The experimental birches were grown for 4 years in two growing conditions (pot and field) at different nutrient levels. There was considerable species-specific quantitative and qualitative variation in the secondary chemicals in bark, but this was also affected by fertilization and the age of the plant. In general, there was greater chemical diversity in saplings than in seedlings. The study revealed three new components, secoisolariciresinol 9-O-β-glucopyranoside and two of its derivatives, that have not been reported previously for the bark of white birches. Principal component analysis showed that the species studied had a similar chemical composition at the juvenile stage, but as the plants grew, they became more clearly differentiated, which indicates that the species of older plants can be identified by chemotaxonomy. Evidently, the secondary chemistry of birches is under genetic control, but it is affected by properties of growing conditions and ontogeny. Electronic Supplementary Material Supplementary material to this paper is available in electronic form at     

Fluorescence-Based Nanoparticle Tracking Analysis and Flow Cytometry for Characterization of Endothelial Extracellular Vesicle Release

As extracellular vesicles (EVs) have become a prominent topic in life sciences, a growing number of studies are published on a regular basis addressing their biological relevance and possible applications. Nevertheless, the fundamental question of the true vesicular nature as well as possible influences on the EV secretion behavior have often been not adequately addressed. Furthermore, research regarding endothelial cell-derived EVs (EndoEVs) often focused on the large vesicular fractions comprising of microvesicles (MV) and apoptotic bodies. In this study we aimed to further extend the current knowledge of the influence of pre-isolation conditions, such as cell density and conditioning time, on EndoEV release from human umbilical vein endothelial cells (HUVECs). We combined fluorescence nanoparticle tracking analysis (NTA) and the established fluorescence-triggered flow cytometry (FT-FC) protocol to allow vesicle-specific detection and characterization of size and surface markers. We found significant effects of cell density and conditioning time on both abundance and size distribution of EndoEVs. Additionally, we present detailed information regarding the surface marker display on EVs from different fractions and size ranges. Our data provide crucial relevance for future projects aiming to elucidate EV secretion behavior of endothelial cells. Moreover, we show that the influence of different conditioning parameters on the nature of EndoEVs has to be considered.     

MIRAS reference radiometer: a fully polarimetric noise injection radiometer

A prototype reference radiometer for the Microwave Imaging Radiometer Using Aperture Synthesis (MIRAS) instrument of the Soil Moisture and Ocean Salinity satellite has been developed. The reference radiometer is an L-band fully polarimetric noise injection radiometer (NIR). The main purposes of the NIR are: 1) to provide precise measurement of the average fully polarimetric brightness temperature scene for absolute calibration of the MIRAS image map and 2) to measure the noise temperature level of the noise distribution network of the MIRAS for individual receiver calibration. The performance of the NIR is a decisive factor of the MIRAS performance. In this paper we present the operation principles and calibration procedures of the NIR, a measurement technique called blind correlation making measurements of full Stokes vector possible with the noise injection method, and finally experimental results verifying certain aspects of the design.