Exposure to flame retardants in European children - Results from the HBM4EU aligned studies

Many legacy and emerging flame retardants (FRs) have adverse human and environmental health effects. This study reports legacy and emerging FRs in children from nine European countries from the HBM4EU aligned studies. Studies from Belgium, Czech Republic, Germany, Denmark, France, Greece, Slovenia, Slovakia, and Norway conducted between 2014 and 2021 provided data on FRs in blood and urine from 2136 children. All samples were collected and analyzed in alignment with the HBM4EU protocols. Ten halogenated FRs were quantified in blood, and four organophosphate flame retardants (OPFR) metabolites quantified in urine. Hexabromocyclododecane (HBCDD) and decabromodiphenyl ethane (DBDPE) were infrequently detected (<16% of samples). BDE-47 was quantified in blood from Greece, France, and Norway, with France (0.36 ng/g lipid) having the highest concentrations. BDE-153 and -209 were detected in <40% of samples. Dechlorane Plus (DP) was quantified in blood from four countries, with notably high median concentrations of 16 ng/g lipid in Slovenian children. OPFR metabolites had a higher detection frequency than other halogenated FRs. Diphenyl phosphate (DPHP) was quantified in 99% of samples across 8 countries at levels ∼5 times higher than other OPFR metabolites (highest median in Slovenia of 2.43 ng/g lipid). FR concentrations were associated with lifestyle factors such as cleaning frequency, employment status of the father of the household, and renovation status of the house, among others. The concentrations of BDE-47 in children from this study were similar to or lower than FRs found in adult matrices in previous studies, suggesting lower recent exposure and effectiveness of PBDE restrictions.

P-067 Correlation between Zn/Cu ratio and Bisphenol A in seminal plasma in men with varicocele

Study question

Is there a relationship between concentration of Bisphenol A (BPA), Zn contents and Zn/Cu ratio in seminal fluid and spermiogram parameters in men with varicocele?

Summary answer

Our results document correlations between BPA, Zn/Cu and sperm motility. We found that the negative effect of BPA can be attenuated by higher Zn/Cu levels.

What is known already

A range of environmental factors including organic endocrine disruptors affects spermatogenesis. Bisphenols are endocrine disruptors often used in production of plastics. BPA is an endocrine disruptor with negative effects on reproduction. Presence of BPA also induces production of reactive oxygen species with negative impact on spermatogenesis. Zinc and copper are trace elements important for human spermatogenesis. Zn and especially the ratio of Zn/Cu are good parameters of the antioxidant potential of seminal plasma. The relationship between BPA levels, Zn concentration and Zn/Cu ratio with human sperm parameters is still unclear.

Study design, size, duration

In this study, we evaluated correlation between BPA concentration, Zn concentration and ratio of Zn/Cu in seminal plasma in relation to sperm concentration, number of spermatozoa, total motility, progressive motility, morphology and DNA fragmentation. A total of 123 nonsmoking patients aged 18 - 45 (average 28) years with varicocele were included in this prospective study from 2019 to 2021.

Participants/materials, setting, methods

All the men signed an informed consent and agreed with analyses. Ethical Committee of University Hospital Brno approved analyses. Seminal plasma was collected after centrifugation. BPA was determined by the LC-MS/MS method (liquid chromatography-tandem mass spectrometry). The concentrations of Zn and Cu were measured by inductively coupled plasma mass spectrometry (Agilent 8900 ICP-MS/MS). Statistical evaluation was performed using Spearmen test (p = 0.05). The relationship between parameters was expressed by Spearman's correlation coefficient (ρ).

Main results and the role of chance

Analytical examination of seminal fluids detected presence of BPA in 89 samples (72.3 % of all samples analysed with average value 0.1627 ng/ml). In 18 samples, the concentration was under the level of detection and in 16 samples under the level of quantification. Zn was detected in all 123 patients with average concentration 139.44 µg/ml. The Zn/Cu ratio was calculated with average value 1.73. Subsequently, individual parameters of spermiogram plus DNA integrity were assessed. In case of BPA, negative correlations were found between BPA concentration and total motility (p = 0.010) and progressive motility (p = 0.012). Similarly, positive significant correlations between Zn/Cu ratio and total motility (p = 0.032) and progressive motility (p = 0.028) were found. For Zn concentration, we found positive non-significant correlation with total motility (p = 0.144) or progressive motility (p = 0.147). There were non-significant correlations between the BPA, Zn/Cu ratio or Zn and other parameters. Similarly, for BPA and Zn/Cu ratio a non-significant positive correlation was found (p = 0.157) and neither significant correlation was found between BPA and Zn (p = 0.452). In several cases we observed normal progressive and total motility in patients with high BPA concentrations together with high Zn/Cu ratio which probably has a protecting effect from the high BPA levels.

Limitations, reasons for caution

A limitation for this study is the final number of patients analysed in this study, which slightly reduced the power of statistical analysis. Currently, more analyses focused on detection of BPA in seminal plasma are being carried out in order to obtain sufficiently larger data set.

Wider implications of the findings

In this study, BPA was detected in 72 % of analysed samples. Our first results indicate a higher sensitivity of spermatozoa to BPA presence in seminal fluid, affecting mainly their motility. Interestingly, a higher Zn/Cu ratio is potent to reduce partially the negative impact of BPA on human spermatozoa.

Trial registration number

Supported by Czech Health Research Council (NV18-01-00544 and NV18-08-00291) and MH CZ – DRO (FNBr, 65269705). Jana Navratilova was supported by the Czech Ministry of Education, Youth and Sports (CZ.02.2.69/0.0/0.0/19_074/0012727). Authors also thanks to Research Infrastructure RECETOX RI (No LM2018121) financed by the Ministry of Education, Youth and Sports, and Operational Programme Research, Development and Innovation - project CETOCOEN EXCELLENCE (No CZ.02.1.01/0.0/0.0/17_043/0009632) for supportive background.

Extended interval dosing of natalizumab in multiple sclerosis

BACKGROUND

Natalizumab (NTZ), a monoclonal antibody to human α4β1/β7 integrin, is an effective therapy for multiple sclerosis (MS), albeit associated with progressive multifocal leukoencephalopathy (PML). Clinicians have been extending the dose of infusions with a hypothesis of reducing PML risk. The aim of the study is to evaluate the clinical consequences of reducing NTZ frequency of infusion up to 8 weeks 5 days.

METHODS

A retrospective chart review in 9 MS centres was performed in order to identify patients treated with extended interval dosing (EID) regimens of NTZ. Patients were stratified into 3 groups based on EID NTZ treatment schedule in individual centres: early extended dosing (EED; n=249) every 4 weeks 3 days to 6 weeks 6 days; late extended dosing (LED; n=274) every 7 weeks to 8 weeks 5 days; variable extended dosing (n=382) alternating between EED and LED. These groups were compared with patients on standard interval dosing (SID; n=1093) every 4 weeks.

RESULTS

17% of patients on SID had new T2 lesions compared with 14% in EID (p=0.02); 7% of patients had enhancing T1 lesions in SID compared with 9% in EID (p=0.08); annualised relapse rate was 0.14 in the SID group, and 0.09 in the EID group. No evidence of clinical or radiographic disease activity was observed in 62% of SID and 61% of EID patients (p=0.83). No cases of PML were observed in EID group compared with 4 cases in SID cohort.

CONCLUSIONS

Dosing intervals up to 8 weeks 5 days did not diminish effectiveness of NTZ therapy. Further monitoring is ongoing to evaluate if the risk of PML is reduced in patients on EID.

SymptoMScreen: A Tool for Rapid Assessment of Symptom Severity in MS Across Multiple Domains

The objective of this study was to describe SymptoMScreen, an in-house developed tool for rapid assessment of MS symptom severity in routine clinical practice, and to validate SymptoMScreen against Performance Scales (PS). MS patients typically experience symptoms in many neurologic domains. A tool that would enable MS patients to efficiently relay their symptom severity across multiple domains to the healthcare providers could lead to improved symptom management. We developed "SymptoMScreen," a battery of 7-point Likert scales for 12 distinct domains commonly affected by MS: mobility, dexterity, body pain, sensation, bladder function, fatigue, vision, dizziness, cognition, depression, and anxiety. We administered SymptoMScreen and PS scales to consecutive MS patients at a specialty MS Care Center. We assessed the criterion and construct validity of SymptoMScreen by calculating Spearmen rank correlations between the SymptoMScreen composite score and PS composite score, and between SymptoMScreen subscale and the respective PS subscale scores, where applicable. A total of 410 patients with MS (age 46.6 ± 12.9 years; 74% female; mean disease duration 12.2 ± 8.7 years) completed the SymptoMScreen and PSs during their clinic visit. Composite SymptoMScreen score correlated strongly with combined PS score (r = 0.88, p < 0.0001). SymptoMScreen sub scores correlated strongly with the criterion measures of the respective PS (r = 0.69-0.87, p < 0.0001). Test-retest reliability of SymptoMScreen and its subscales was excellent (r = 0.71-0.94, p < .0001). SymptoMScreen is a single-page battery of Likert scales that assesses symptom impact in 12 domains commonly affected in MS. It has excellent criterion and construct validity. SymptoMScreen is patient and clinician friendly, takes approximately one minute to complete, and can help better document, understand, and manage patients' symptoms in routine clinical practice. SymptoMScreen is freely available to clinicians and researchers.

Factors Affecting Antioxidant Response in Fish from a Long-term Mercury-Contaminated Reservoir

The objective of this work was to evaluate antioxidant defence and oxidative damage in organs (liver, gills, kidney, and brain) of five fish species (Aspius aspius, Esox lucius, Sander lucioperca, Abramis brama, Rutilus rutilus) from the long-term mercury-contaminated Skalka Reservoir in the Czech Republic. Special emphasis was placed on a comprehensive assessment of the factors that may affect the antioxidant response to mercury in fish. Antioxidant enzymes (glutathione reductase, glutathione peroxidase, and glutathione-S-transferase) did not significantly respond to mercury contamination. Levels of the analysed enzymes and oxidative damage to lipids were predominantly determined by a separate organ factor or species factor, or by the combination of both (p < 0.001). Levels of total glutathione and the reduced/oxidized glutathione ratio were influenced by mercury contamination in combination with their specific organ distribution (p < 0.001). Our results suggest that species and type of organ alone or in combination are more important factors than chronic exposure to mercury contamination with respect to effects on antioxidant defence in fish under field conditions. Our findings suggest that the main antioxidant defensive mechanism in fish from the studied long-term mercury contaminated site was the inter-tissue distribution of glutathione.

The development of antenna complexes of barley (Hordeum vulgare cv. Akcent) under different light conditions as judged from the analysis of 77 K chlorophyll a fluorescence spectra

Using 77 K chlorophyll a (Chl a) fluorescence spectra in vivo, the development was studied of Photosystems II (PS II) and I (PS I) during greening of barley under intermittent light followed by continuous light at low (LI, 50 mumol m(-2) s(-1)) and high (HI, 1000 mumol m(-2) s(-1)) irradiances. The greening at HI intermittent light was accompanied with significantly reduced fluorescence intensity from Chl b excitation for both PS II (F685) and PS I (F743), in comparison with LI plants, indicating that assembly of light-harvesting complexes (LHC) of both photosystems was affected to a similar degree. During greening at continuous HI, a slower increase of emission from Chl b excitation in PS II as compared with PS I was observed, indicating a preferred reduction in the accumulation of LHC II. The following characteristics of 77 K Chl a fluorescence spectra documented the photoprotective function of an elevated content of carotenoids in HI leaves: (1) a pronounced suppression of Soret region of excitation spectra (410-450 nm) in comparison with the red region (670-690 nm) during the early stage of greening indicated a strongly reduced excitation energy transfer from carotenoids to the Chl a fluorescing forms within PS I and PS II; (2) changes in the shape of the excitation band of Chl b and carotenoids (460-490 nm) during greening under continuous light confirmed that the energy transfer from carotenoids to Chl a within PS II remained lower as compared with the LI plants.

First- and second-year aboveground growth and productivity of two Populus hybrids grown at ambient and elevated CO(2)

Two hybrid poplar (Populus) clones (the fast-growing clone Beaupré (P. trichocarpa Torr. and Gray x P. deltoides Bartr. ex Marsh.) and the slow-growing clone Robusta (P. deltoides Bartr. ex Marsh. x P. nigra L.)) were grown from hardwood cuttings for one or two growing seasons (1993-1994) in either ambient or elevated (= ambient + 350 micro mol mol(-1)) CO(2) in open-top chambers at the University of Antwerpen. Both clones responded positively to the elevated CO(2) treatment with increased stem volume and aboveground biomass production; however, the clones exhibited different response strategies to the elevated CO(2) treatment, and the responses varied with cutting age and duration of exposure. Clone Beaupré responded to the elevated CO(2) treatment with increases in leaf area and leaf area index during both the first and second growing seasons, but little increase in height growth. Clone Robusta exhibited increased height growth, leaf biomass and total leaf nitrogen content in response to elevated CO(2), but no increase in leaf area index. The elevated CO(2) treatment increased the total number of branches and total branch biomass in both clones during both growing seasons. At the end of the first growing season, woody stem biomass of the fast- and slow-growing clones was increased by 38 and 55%, respectively. At the end of the second growing season, stem volume was increased by 43% in clone Beaupré and by 58% in clone Robusta. The increase in stem volume was a result of the stimulation of both height and diameter growth in the slow-growing clone, whereas only height growth was stimulated in the fast-growing clone. In the fall of the first growing season, the average date of bud set in clone Robusta was advanced by 4 days in the elevated CO(2) treatment; there were no other significant effects of the elevated CO(2) treatment on bud set. The elevated CO(2) treatment enhanced leaf C/N ratios in both clones in both years.