Practical implementation, characterization and applications of a multi-colour time-gated luminescence microscope

Time-gated luminescence microscopy using long-lifetime molecular probes can effectively eliminate autofluorescence to enable high contrast imaging. Here we investigate a new strategy of time-gated imaging for simultaneous visualisation of multiple species of microorganisms stained with long-lived complexes under low-background conditions. This is realized by imaging two pathogenic organisms (Giardia lamblia stained with a red europium probe and Cryptosporidium parvum with a green terbium probe) at UV wavelengths (320-400 nm) through synchronization of a flash lamp with high repetition rate (1 kHz) to a robust time-gating detection unit. This approach provides four times enhancement in signal-to-background ratio over non-time-gated imaging, while the average signal intensity also increases six-fold compared with that under UV LED excitation. The high sensitivity is further confirmed by imaging the single europium-doped Y2O2S nanocrystals (150 nm). We report technical details regarding the time-gating detection unit and demonstrate its compatibility with commercial epi-fluorescence microscopes, providing a valuable and convenient addition to standard laboratory equipment

Prevalence of inappropriate medication using Beers criteria in Japanese long-term care facilities

BACKGROUND: The prevalence and risk factors of potentially inappropriate medication use among the elderly patients have been studied in various countries, but because of the difficulty of obtaining data on patient characteristics and medications they have not been studied in Japan. METHODS: We conducted a retrospective cross-sectional study in 17 Japanese long-term care (LTC) facilities by collecting data from the comprehensive MDS assessment forms for 1669 patients aged 65 years and over who were assessed between January and July of 2002. Potentially inappropriate medications were identified on the basis of the 2003 Beers criteria. RESULTS: The patients in the sample were similar in terms of demographic characteristics to those in the national survey. Our study revealed that 356 (21.1%) of the patients were treated with potentially inappropriate medication independent of disease or condition. The most commonly inappropriately prescribed medication was ticlopidine, which had been prescribed for 107 patients (6.3%). There were 300 (18.0%) patients treated with at least 1 inappropriate medication dependent on the disease or condition. The highest prevalence of inappropriate medication use dependent on the disease or condition was found in patients with chronic constipation. Multiple logistic regression analysis revealed psychotropic drug use (OR = 1.511), medication cost of per day (OR = 1.173), number of medications (OR = 1.140), and age (OR = 0.981) as factors related to inappropriate medication use independent of disease or condition. Neither patient characteristics nor facility characteristics emerged as predictors of inappropriate prescription. CONCLUSION: The prevalence and predictors of inappropriate medication use in Japanese LTC facilities were similar to those in other countries

Multiple identification of most important waterborne protozoa in surface water used for irrigation purposes by 18S rRNA amplicon-based metagenomics

[EN] Understanding waterborne protozoan parasites (WPPs) diversity has important implications in public health. In this study, we evaluated a NGS-based method as a detection approach to identify simultaneously most important WPPs using 18S rRNA high-throughput sequencing. A set of primers to target the V4 18S rRNA region of WPPs such as Cryptosporidium spp., Giardia sp., Blastocystis sp., Entamoeba spp, Toxoplasma sp. and free-living amoebae (FLA) was designed. In order to optimize PCR conditions before sequencing, both a mock community with a defined composition of representative WPPs and a real water sample inoculated with specific WPPs DNA were prepared. Using the method proposed in this study, we have detected the presence of Giardia intestinalis, Acanthamoeba castellanii, Toxoplasma gondii, Entamoeba histolytica and Blastocystis sp. at species level in real irrigation water samples. Our results showed that untreated surface irrigation water in open fields can provide an important source of WPPs. Therefore, the methodology proposed in this study can establish a basis for an accurate and effective diagnostic of WPPs to provide a better understanding of the risk associated to irrigation water.This work was supported through the project funded by the Spanish Ministry of Economy and Competitiveness (MINECO) in the frame of the collaborative international consortium JPIW2013-095-C03-02 of the Water Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call. R. Perez acknowledges support from MINECO program "Promocion de Empleo Joven e Implantacion de la Garantia Juvenil en I + D + i".Moreno Trigos, MY.; Moreno-Mesonero, L.; Amoros, I.; Pérez-Santonja, R.; Morillo, J.; Alonso Molina, JL. (2018). Multiple identification of most important waterborne protozoa in surface water used for irrigation purposes by 18S rRNA amplicon-based metagenomics. International Journal of Hygiene and Environmental Health. 221(1):102-111. https://doi.org/10.1016/j.ijheh.2017.10.008S102111221

Crossed Clustering Method on Symbolic Data Tables

In this paper a crossed clustering algorithm is proposed to partitioning a set of symbolic objects in a fixed number of classes. This algorithm allows, at the same time, to determine a structure (taxonomy) on the categories of the object descriptors. This procedure is an extension of the classical simultaneous clustering algorithms, proposed on binary and contingency tables. It is based on a dynamical clustering algorithm on symbolic objects. The optimized criterion is the Φ2 distance computed between the objects description, given by modal variables (distributions) and the prototypes of the classes, described by marginal profiles of the objects set partitions. The convergence of the algorithm is guaranteed at a stationary value of the criterion, in correspondence of the best partition of the symbolic objects in r classes and the best partition of the symbolic descriptors in c groups. An application on web log data has allowed to validate the procedure and suggest it as an useful tool in the Web Usage Mining context. Fulltext Previe