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Drug-induced (secondary) sclerosing cholangitis has recently been observed with a number of agents (1). Ketamine is a remarkably safe anesthetic, providing sedation and analgesia as adjunct to or substitute for more traditional sedative medications. Although prior reports of recreational ketamine abuse have been associated with findings of secondary sclerosing cholangitis (SSC; 2,3), we report here a novel presentation of the syndrome in association with prolonged ketamine use in the intensive care unit.The cathepsin K (CatK) enzyme is abundantly expressed in osteoclasts, and CatK inhibitors have been developed for the treatment of osteoporosis. In our effort to support discovery and clinical evaluations of a CatK inhibitor, we sought to discover a radioligand to determine target engagement of the enzyme by therapeutic candidates using positron emission tomography (PET). click here L-235, a potent and selective CatK inhibitor, was labeled with carbon-11. PET imaging studies recording baseline distribution of [11 C]L-235, and chase and blocking studies using the selective CatK inhibitor MK-0674 were performed in juvenile and adult nonhuman primates (NHP) and ovariectomized rabbits. Retention of the PET tracer in regions expected to be osteoclast-rich compared with osteoclast-poor regions was examined. Increased retention of the radioligand was observed in osteoclast-rich regions of juvenile rabbits and NHP but not in the adult monkey or adult ovariectomized rabbit. Target engagement of CatK was observed in blocking studies with MK-0674, and the radioligand retention was shown to be sensitive to the level of MK-0674 exposure. [11 C]L-235 can assess target engagement of CatK in bone only in juvenile animals. [11 C]L-235 may be a useful tool for guiding the discovery of CatK inhibitors.Liquid chromatography, coupled with tandem mass spectrometry, presents a powerful tool for the quantification of the sex steroid hormones 17-β estradiol, progesterone and testosterone from biological matrices. The importance of accurate quantification with these hormones, even at endogenous levels, has evolved with our understanding of the role these regulators play in human development, fertility and disease risk and manifestation. Routine monitoring of these analytes can be accomplished by immunoassay techniques, which face limitations on specificity and sensitivity, or using gas chromatography-mass spectrometry. LC-MS/MS is growing in capability and acceptance for clinically relevant quantification of sex steroid hormones in biological matrices and is able to overcome many of the limitations of immunoassays. Analyte specificity has improved through the use of novel derivatizing agents, and sensitivity has been refined through the use of high-resolution chromatography and mass spectrometric technology. This review highlights these innovations, among others, in LC-MS/MS steroid hormone analysis captured in the literature over the last decade.
The authenticity of honey is of high importance since it affects its commercial value. The discrimination of the origin of honey is of prime importance to reinforce consumer trust. In this study, four chemometric models were developed based on the physicochemical parameters according to European and Greek legislation and one using Raman spectroscopy to discriminate Greek honey samples from three commercial monofloral botanical sources.
The results of physicochemical (glucose, fructose, electrical activity) parameters chemometric models showed that the percentage of correct recognition fluctuated from 92.2% to 93.8% with cross-validation 90.6-92.2%, and the placement of test set was 79.0-84.3% successful. The addition of maltose content in the previous discrimination models did not significantly improve the discrimination. The corresponding percentages of the Raman chemometric model were 95.3%, 90.6%, and 84.3%.
The five chemometric models developed presented similar and very satisfactory results. Given that the recording of Raman spectra is simple, fast, a minimal amount of sample is needed for the analysis, no solvent (environmentally friendly) is used, and no specialized personnel are required, we conclude that the chemometric model based on Raman spectroscopy is an efficient tool to discriminate the botanical origin of fir, pine, and thyme honey varieties. © 2020 Society of Chemical Industry.
The five chemometric models developed presented similar and very satisfactory results. Given that the recording of Raman spectra is simple, fast, a minimal amount of sample is needed for the analysis, no solvent (environmentally friendly) is used, and no specialized personnel are required, we conclude that the chemometric model based on Raman spectroscopy is an efficient tool to discriminate the botanical origin of fir, pine, and thyme honey varieties. © 2020 Society of Chemical Industry.Chromosome number is a central feature of eukaryote genomes. Deciphering patterns of chromosome-number change along a phylogeny is central to the inference of whole genome duplications and ancestral chromosome numbers. ChromEvol is a probabilistic inference tool that allows the evaluation of several models of chromosome-number evolution and their fit to the data. However, fitting a model does not necessarily mean that the model describes the empirical data adequately. This vulnerability may lead to incorrect conclusions when model assumptions are not met by real data. Here, we present a model adequacy test for likelihood models of chromosome-number evolution. The procedure allows us to determine whether the model can generate data with similar characteristics as those found in the observed ones. We demonstrate that using inadequate models can lead to inflated errors in several inference tasks. Applying the developed method to 200 angiosperm genera, we find that in many of these, the best-fitting model provides poor fit to the data. The inadequacy rate increases in large clades or in those in which hybridizations are present. The developed model adequacy test can help researchers to identify phylogenies whose underlying evolutionary patterns deviate substantially from current modelling assumptions and should guide future methods development.