Gilbertlausen1990

[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.Conifers are considered to prefer to take up ammonium (NH4+ ) over nitrate (NO3- ). However, this conclusion is mainly based on hydroponic experiments that separate roots from soils. It remains unclear to what extent mature conifers can use nitrate compared to ammonium under field conditions where both roots and soil microbes compete for nitrogen (N). We conducted an in situ whole mature tree nitrogen-15 (15 N) labeling experiment (15 NH4+ vs 15 NO3- ) over 15 d to quantify ammonium and nitrate uptake and assimilation rates in four 40-yr-old monoculture coniferous plantations (Pinus koraiensis, Pinus sylvestris, Picea koraiensis and Larix olgensis, respectively). For the whole tree, 15 NO3- contributed 39% to 90% to total 15 N tracer uptake among four plantations during the study period. At day 3, the 15 NO3- accounted for 77%, 64%, 62% and 59% by Larix olgensis, Pinus koraiensis, Pinus sylvestris and Picea koraiensis, respectively. Our study indicates that mature coniferous trees assimilated nitrate as efficiently as ammonium from soils even at low soil nitrate concentration, in contrast to the results from hydroponic experiments showing that ammonium uptake dominated over nitrate. This implies that mature conifers can adapt to increasing availability of nitrate in soil, for example, under the context of globalization of N deposition and global warming.The influence of experimental conditions on chromatographic behaviour of promising oligodeoxynucleotide double-labelled molecular probes containing an azaphthalocyanine macrocycle as a perspective dark quencher was studied. A recently introduced new stationary phase based on styrene-divinylbenzene copolymer was tested. The planar and hydrophobic structure of the azaphthalocyanine is considerably different from those of currently used fluorophores and quenchers. Thus, the most challenging issue was the separation of the double-labelled probe from its main impurity represented by a mono-labelled probe, containing only the azaphthalocyanine macrocycle. The absorbance measurement cannot simply determine this impurity, and its presence fundamentally compromises the biological assay. The commonly used gradient elution was not suitable and isocratic conditions seemed to be more appropriate. The azaphthalocyanine moiety influences the properties of the modified oligodeoxynucleotides substantially, and thus their chromatographic behaviour was determined predominantly by this quencher. Acetonitrile was the preferred organic solvent for the analysis of probes containing the azaphthalocyanine quencher and the effect of ion-pairing reagents was dependent on the probe structure. The temperature seemed to be an effective parameter for fine-tuning of the separation and mass transfer improvement. Generally, our findings could be helpful in method development for purity evaluation of double-labelled oligodeoxynucleotide probes and semipreparative methods.

When used proactively, drug-tolerant anti-tumour necrosis factor (TNF) antibody assays provide early opportunity to suppress immunogenicity.

To validate positivity thresholds of IDKmonitor drug-tolerant anti-infliximab and -adalimumab antibody assays.

We applied positivity thresholds, defined by testing sera from 498 anti-TNF naive healthy adults, from the Exeter Ten Thousand study to data from our therapeutic drug monitoring (TDM) service and Personalised Anti-TNF Therapy in Crohn's disease (PANTS) cohort to explore associations with drug level and treatment outcomes.

The 80% one-sided lower confidence interval of the 99th centile concentration for anti-infliximab and -adalimumab antibodies were lower than the manufacturers threshold of 10 arbitrary units (AU)/mL; 9 and 6AU/mL, respectively. Using these new thresholds in the TDM cohort, more adalimumab- than infliximab- (11.2% [814/7272] vs 3.1% [390/12683] P<0.0001) treated patients were reclassified as antibody-positive. Adalimumab drug concentrnt failure.

Laboratories should derive antibody positivity thresholds for assays they use. For adalimumab, low-concentration anti-drug antibodies were associated with lower drug levels and treatment failure.A facile supercritical fluid chromatography method is proposed to analyse 15 co-formulated binary anti-hypertensive drug combinations using a customized elution procedure. The effect of mobile phase composition, column back pressure and temperature was suitably optimized for adequate retention, analyte response and resolution. The chromatographic separation of the different drug combinations was performed on a DCPak poly(4-vinylpyridine) column (250 × 4.6 mm, 5 μm) at 125-bar pressure and 40°C using a photodiode array detector. A linear gradient of CO2 and 0.1% formic acid in methanol provided the best elution conditions for all drug combinations. Baseline separation of the drugs was possible with resolution factor Rs ranging from 1.42 to 12.58. The method was validated for specificity, sensitivity, accuracy and precision, recovery and robustness. The limit of detection and limit of quantitation for aliskiren, amlodipine, atenolol, candesartan, hydrochlorothiazide, lisinopril, losartan, metoprolol, olmesartan, telmisartan and valsartan were in the range of 0.26-2.56 and 0.77-7.75 μg/mL, respectively. The thermodynamic study revealed that interactions of the drugs with the stationary phase were spontaneous as evident from the negative free energy values, and the separation process was enthalpy driven. The developed method was successfully employed to analyse these drugs in their co-formulated tablet formulations.Ischemia/reperfusion (I/R) is one of the common reasons for acute kidney injury (AKI) and we need to develop effective therapies for treating AKI. We investigated the role of fenofibrate against I/R-induced AKI and associated hepatic dysfunction in rats. In male wistar albino rats, renal pedicle occlusion for 40 min and 24 h reperfusion resulted in AKI. I/R-induced AKI was demonstrated by measuring serum creatinine, creatinine clearance, urea, uric acid, potassium, fractional excretion of sodium and urinary microproteins. Oxidative stress in rat kidneys was quantified by assaying superoxide anion generation, thiobarbituric acid reactive substances, and reduced glutathione levels. AKI-induced hepatic damage was quantified by assaying serum aminotransferases, alkaline phosphatase and bilirubin levels. Moreover, serum cholesterol, high density lipoprotein and triglycerides were quantified. Hematoxylin-eosin staining of renal and hepatic tissues was done and the kidney and liver injury scores were determined. Immunohistology of endothelial nitric oxide synthase (eNOS) was done in rat kidneys. Fenofibrate was administered for 1 week before subjecting rats to AKI. In separate group, the nitric oxide synthase inhibitor, L-nitroarginine methyl ester (L-NAME) was administered prior to fenofibrate treatment. In I/R group, significant alteration in the serum/urine parameters indicated AKI and hepatic dysfunction along with marked increase in kidney and liver injury scores. Treatment with fenofibrate attenuated AKI and associated hepatic dysfunction. Moreover, I/R-induced decrease in renal eNOS expression was abrogated by fenofibrate. Pre-treatment with L-NAME abolished fenofibrate mediated reno- and hepato-protective effects. In conclusion, fenofibrate attenuates I/R-induced AKI and associated hepatic dysfunction putatively through modulation of eNOS expression.