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The metabolic functionality of the gut microbiota contributes to the metabolism and well-being of its host, although detailed insight in the microbiota's metabolism is lacking. Omics technologies could facilitate unraveling metabolism by the gut microbiota. In this study, we performed metabolite profiling of different matrices of the gut, after antibiotic treatment of rats in order to evaluate metabolite changes observed at different dose levels and in different sexes, and to identify the best tissue matrix for further investigations regarding an assessment of metabolic effects of new compounds with antibiotic activity. Three different antibiotics (vancomycin, streptomycin and roxithromycin) were administered orally to rats for 28 days according to the OECD 407 guideline with a subsequent metabolic profiling in feces, cecum content and gut tissue (jejunum, ileum, cecum, colon and rectum). The data were analyzed in the MetaMap®Tox database. Treatment-related effects could be observed in the metabolite profile of feces and cecum content, but not of the different gut tissues. The metabolite profile showed compound specific effects on the microbiome. In line with the activity spectra of the antibiotics tested, vancomycin showed the largest effects, followed by roxithromycin and then by streptomycin for which changes were modest. In general, for all antibiotics the largest changes were observed for the classes of lipids (increase up to 94-fold), bile acids (increase up to 33-fold), amino acids (increase up to 200-fold) and amino acid related (increase up to 348-fold). The most relevant changes in metabolite values were similar in feces and cecum content and among sexes. The results of this targeted analysis indicate that the metabolic profiles of male and female animals in the gut microbiome are comparable. Concluding, taking other samples than feces does not add any extra information. Thus, as a non-invasive sampling method, feces provide a suitable matrix for studies on metabolism by the gut microbiota. [ABSTRACT FROM AUTHOR]

New technologies, such as metabolomics, can address chemical grouping and read across from a biological perspective. In a virtual case study, we selected MCPP as target substance and MCPA and 2,4-DP as source substances with the goal to waive a 90-day study with MCPP. In order to develop a convincing case to show how biological data can substantiate read across, we used metabolomics on blood samples from the 28-day studies to show the qualitative and quantitative similarity of the substances. The 28-day metabolome evaluation of source substances and the target substance indicate liver and kidneys as target organs. 2,4-DP was identified as the best source substance. Using the information of the 90-day 2,4-DP study, we predicted MCPP's toxicity profile at 2500 ppm: reduced food consumption and body weight gain, liver and kidney weight increases with clinical-pathology changes and a moderate red blood cell parameter reduction. NOEL prediction for MCPP was below that of 2,4-DP (<500 ppm), and similar to that of MCPA (≥150 ppm). Qualitatively, these predictions are comparable to the results of the real MCPP 90-day study in rats (reduced food consumption and body weight gain, weight increases and clinical-pathology changes in liver and kidneys, reduced red blood cells values). Quantitatively, the predicted NOAEL (150 ppm) is similar to the actual study (NOEL = 75 ppm, NOAEL ≤ 500 ppm). Thus, the 90-day rat toxicity study of MCPP could have been waived and substituted by the 90-day results of 2,4-DP by using metabolome data of 28 day studies. [ABSTRACT FROM AUTHOR]

Objective: To determine whether naproxen, a propionic acid inhibitor of cyclooxygenase, alters the course of experimental rhinovirus colds.Design: A randomized, double-blind, controlled trial.Setting: Rhinovirus challenge model in volunteers cloistered in individual hotel rooms.Volunteers: Eighty-seven healthy young adults with serum neutralizing antibody titers of less than or equal to 1:2 to the challenge virus; 79 were evaluable.Intervention: Thirty-nine participants received naproxen (loading dose, 400 mg or 500 mg followed by 200 mg or 500 mg three times daily for 5 days). Forty participants received placebo. Treatment was started 6 hours after viral challenge.Measurements: Daily measurement of viral titers, symptoms, nasal mucus production, and nasal tissue use; incidence of infection and illness; and measurement of homotypic serum neutralizing antibody responses.Results: Viral titers and serum homotypic antibody responses were similar in the naproxen and placebo groups. Significant reductions in headache, malaise, myalgia, and cough occurred in the naproxen group. A 29% reduction was noted in the total (5-day) symptom score in the naproxen group (95% CI, 16% to 42%).Conclusion: Naproxen treatment did not alter virus shedding or serum neutralizing antibody responses in participants with experimental rhinovirus colds, but it had a beneficial effect on the symptoms of headache, malaise, myalgia, and cough. Prostaglandins may be among the inflammatory mediators that play a role in the pathogenesis of rhinovirus colds. [ABSTRACT FROM AUTHOR]

Background In 2009, the General Medical Council (GMC) updated its guidance on consent, introducing a new statement that employees should be offered the opportunity to view reports, before the reports are sent to the employer. Aims To investigate the effects of this change on the perceptions and practice of occupational physicians. Methods A cross-sectional survey of UK occupational physicians via the Society of Occupational Medicine e-newsletter, seeking their opinions of the anticipated and actual effects of the guidance on employers, employees, occupational physicians and occupational health services. Results Two hundred and ninety-five completed questionnaires were returned (estimated response rate 30%). Respondents included 25% of accredited UK specialists. Some reported improved standards and greater transparency, however the change was generally perceived as unfavourable, with employee and employer losses: 50% reported delay providing timely advice to employers and 35% reported delays in employees returning to work. Significant variation in practice and increased costs were reported, with variable effects on different services. Difficulties in areas such as pensions and health surveillance were reported. Some occupational physicians had moved to instant reporting; others had moved away from this to allow more care with wording of reports. Conclusions We found significant variations in practice between occupational physicians and concerns of employee and employer losses as a result of changes to the GMC consent guidance. Clearer guidance on practical implementation was desired. The background ethical reasoning should be stated so that the parameters of the guidance are delineated and its reach should be clarified. [ABSTRACT FROM PUBLISHER]

Read-across and grouping is one of the most commonly used alternative approaches for data gap filling in registrations submitted under the REACH Regulation as defined by the European Chemicals Agency (ECHA) in their 'Read-Across Assessment Framework' (RAAF, 2017). At the same time, the application of read-across is rejected by ECHA frequently due to various reasons. As a major reason hereof, applicants fail to reduce the level of 'remaining uncertainty' intrinsical to every read-across approach compared to testing a substance experimentally. Recently, the use of metabolomics to support read-across cases with biological information has been reported in a case study with phenoxy herbicides (Ravenzwaay et al., 2016). In the present case-study a 'weight-of-evidence' read-across approach from 2-aminoethanol (MEA = 'source') to 3-aminopropanol (3AP = 'target') with metabolomics as 'supporting evidence' reducing the remaining uncertainties is reported. We demonstrate the high structural similarity of the two analogous substances based on the available data and we report how metabolome data add confidence concerning mechanistic similarity in this read-across approach. Finally, the herein described read-across case supported by metabolomics is used to cover the data gaps in repeated dose and reproductive toxicity endpoint of 3AP via weight of evidence for the REACH-registration. • A read across from 2-aminoethanol (MEA) to 3-aminopropanol (3AP) is presented. • Metabolomics is used to add biological information to support the read across case. • BASF's MetaMap®Tox database was used to identify the best read across option. [ABSTRACT FROM AUTHOR]

Structure-based grouping of chemicals for targeted testing and read-across is an efficient way to reduce resources and animal usage. For substances of unknown or variable composition, complex reaction products, or biological materials (UVCBs), structure-based grouping is virtually impossible. Biology-based approaches such as metabolomics could provide a solution. Here, 15 steam-cracked distillates, registered in the EU through the Lower Olefins Aromatics Reach Consortium (LOA), as well as six of the major substance constituents, were tested in a 14-day rat oral gavage study, in line with the fundamental elements of the OECD 407 guideline, in combination with plasma metabolomics. Beyond signs of clinical toxicity, reduced body weight (gain), and food consumption, pathological investigations demonstrated the liver, thyroid, kidneys (males only), and hematological system to be the target organs. These targets were confirmed by metabolome pattern recognition, with no additional targets being identified. While classical toxicological parameters did not allow for a clear distinction between the substances, univariate and multivariate statistical analysis of the respective metabolomes allowed for the identification of several subclusters of biologically most similar substances. These groups were partly associated with the dominant (> 50%) constituents of these UVCBs, i.e., indene and dicyclopentadiene. Despite minor differences in clustering results based on the two statistical analyses, a proposal can be made for the grouping of these UVCBs. Both analyses correctly clustered the chemically most similar compounds, increasing the confidence that this biological approach may provide a solution for the grouping of UVCBs. [ABSTRACT FROM AUTHOR]

Highlights • Metabolomics is a useful tool for a mechanism-based identification of rat maternal toxicity. • The metabolome-derived NOEL was more sensitive in detecting maternal toxicity than the maternal NOAEL. • Specific metabolome patterns were established in pregnant rats. Abstract For regulatory purposes prenatal developmental toxicity (OECD No. 414) studies are routinely performed in our laboratories. The suitability of metabolomics as technology to identify maternal toxicity in such studies was investigated. Plasma was sampled from pregnant, non-fasted rats on gestation day 20 before cesarean section. Metabolite profiling was performed by gas- and liquid-chromatography-tandem mass spectrometry techniques. The sensitivity of routinely examined maternal toxicity parameters (OECD No. 414) was compared to those of metabolome analysis. Evaluating 44 studies, the metabolome-derived NOEL was more sensitive in 45% of the cases in detecting maternal toxicity than the maternal NOAEL. Metabolome patterns indicative for liver effects and 4-hydroxyphenylpyruvate dioxygenase (HPPD) enzyme-inhibition were established in pregnant rats based on regulated metabolites using reference compounds. The HPPD inhibition and liver toxicity patterns in pregnant rats were reasonably comparable to the ones established in non-pregnant, fasted rats. Metabolomics is a useful tool for an improved and mechanism-based identification of maternal toxicity in maternal and prenatal toxicity studies. The data suggest that the current classical maternal toxicity parameters may underestimate the extent of effects of compounds on the dams. [ABSTRACT FROM AUTHOR]

Abstract The bile acid-liver-gut microbiota axis plays an important role in the host's health. The gut microbiota has an impact on the bile acid pool, but also the bile acids themselves can influence the gut microbiota composition. In this study, six antibiotics from five different classes (i.e. lincosamides, glycopeptides, macrolides, fluoroquinolones, aminoglycosides) were used to modulate microbial communities of Wistar rats to elucidate changes in the bile acid metabolism and to identify key metabolites in the bile acid pool related to gut microbial changes. 20 primary and secondary bile acids were analyzed in plasma and feces of control and treated animals. Antibiotics treatment induced significant changes in primary and secondary bile acids in both matrices. Taurine-conjugated primary bile acids significantly increased in plasma and feces. Contrary, cholic acid and most of the analyzed secondary bile acids significantly decreased in plasma, and cholic acid accumulated in the feces after treatment with all antibiotics but roxithromycin. Despite the different activity spectra of the antibiotics applied against gut microbes, the overall effect on the bile acid pool tended to be similar in both matrices except for streptomycin. These results show that changes in the gut microbial community affect the bile acid pool in plasma and feces and that changes in the bile acid profile can be indicative of alterations of the gut microbiome. Due to the important role of bile acids for the host, changes in the bile acid pool can have severe consequences for the host. Highlights • Antibiotics induced significant changes in primary and secondary bile acids. • Changes in the gut microbiome affect the bile acid pool in plasma and feces. • Taurine-conjugated primary bile acids significantly increased in plasma and feces. • Cholic acid and most of the analyzed secondary bile acids significantly decreased. [ABSTRACT FROM AUTHOR]

Introduction: Adult patients with ADHD suffer from marriage problems and increased divorce rates significantly more often. There are, however, only a few studies which analyse romantic attachment to a partner or romantic relationships among patients with ADHD in view of attachment theory. Aims: The aim of the present study is to research if ADHD patients show a diminished quality of romantic relationships in comparison to a matched sample of healthy controls. Furthermore, correlations between ADHD specific characteristics and particular variables of partnership perception and psychosomatic discomfort were analysed within the ADHD subgroup. Methods: We recruited 39 patients with ADHD and compared them with a matched sample of healthy controls. Self-estimation measures were used to examine the quality of attachment, dimensions of attachment, love styles, psychosomatic discomfort and ADHD specific symptoms. Results: In comparison to the control sample, adult ADHD patients show a significantly reduced quality of relationships. ADHD patients rank themselves as more scared of attachment and showing more avoidance of interpersonal relationships in general as well as romantic relationships. They also feel less romantic love. ADHD specific characteristics correlate moderately with the attachment dimensions “Fear” and “Avoidance”, the love style “Mania” and psychosomatic discomfort. Conclusions: This study lends further support to the assumption that adult patients with ADHD show an impaired quality of attachment, increased fear and avoidance of relationships as well as less romantic love. The results strongly underline the necessity to account for individual attachment styles in psychotherapy of ADHD. [ABSTRACT FROM AUTHOR]

Dehydroepiandrostreone (DHEA) is a neuroactive steroid produced by the inner layer of the adrenal cortex close to the adrenomedullary cells. Chromaffin cell growth and proliferation are under the control of insulin-like growth factor II (IGF-II) and basic fibroblast growth factor (bFGF). The aim of the present study was to examine the role of DHEA on chromaffin cell proliferation induced by IGF-II and bFGF. In our model, DHEA significantly decreased IGF-II-induced proliferation by 48.7%, whereas it did not affect the proliferation induced by bFGF. These data suggest that DHEA exerts a paracrine function in the control of chromaffin cell growth. [ABSTRACT FROM AUTHOR]