Iliac artery endofibrosis: diagnostic dilemna and treatment options.

BACKGROUND: External iliac artery endofibrosis (EIAE) is an uncommon pathology, predominantly occurring in cyclists, caused by thickening of the external iliac artery intima. Symptoms are exercise-dependent and typically consist of pain, muscle cramps and loss of strength in the affected limb at (sub)maximal effort. As other musculo-skeletal as well as conditional problems might cause similar complaints diagnosis is not always easy or straightforward. CASE SUMMARY AND DISCUSSION: We reviewed four cases of (semi-)professional cyclists referred to our department in 2021 because of suspicion of EIAE. In all symptoms only occurred at (sub)maximal effort. All had lowering of ABI on the affected side at a dynamic stress test on the bike. Imaging using CTA, MRA or dynamic angiogram was abnormal in all patients, showing signs suspicious for endofibrosis but of different kind and at different locations. Open surgical repair was performed in all cases by a procedure tailored to the type of lesion. Two patients were treated by a saphenous vein patch angioplasty, in one patient a shortening of the vessel and end-to-end anastomosis was performed and in the fourth patient a spiral saphenous vein graft bypass was placed. Postoperative course was uneventful and exercise was resumed after four weeks in all patients. CONCLUSION: Correct diagnosis is essential in the treatment of EIAE. A complete and multidisciplinary pathway should be followed to distinguish vascular from non-vascular causes. Correct lesion localization is crucial and besides CTA or MRA, more sophisticated techniques such as dynamic angiography or intravascular ultrasound might be needed.

Assessing the receptor-mediated activity of PAHs using AhR-, ERα- and PPARγ- CALUX bioassays.

Polycyclic aromatic hydrocarbons (PAH) are a complex group of organic compounds, consisting of at least three fused aromatic rings, which are formed during combustion of organic matter. While some PAHs have been reported to have carcinogenic and/or mutagenic properties, another possible negative health impact is their endocrine disrupting potential. Therefore, the aim of this study was to determine both the agonistic and antagonistic endocrine activity of 9 environmentally relevant PAHs using three different CALUX bioassays: The AhR-CALUX, The ERα-CALUX and PPARγ-CALUX. For the PPARγ-CALUX anthracene, fluoranthene, pyrene and fluorene showed weak agonistic activity, whilst benzo(a)pyrene (B(a)P) was the only one exhibiting weak antagonistic activity. For the AhR-CALUX, chrysene was the only PAH that showed relatively strong agonist activity (except for B(a)P which was used as a standard). Pyrene, anthracene and fluoranthene showed weak AhR agonist activity. In the ERα-CALUX bioassay, fluoranthene had agonistic activity whilst B(a)P exhibited both agonistic and antagonistic activity (lowering E2 activity by 30%). Phenanthrene and anthracene had weak ERα agonist activities. These results indicate that certain PAHs have multiple modes of action and can activate/inhibit multiple receptor signaling pathways known to play critical roles in mediating endocrine disruption.

Endocrine activity in an urban river system and the biodegradation of estrogen-like endocrine disrupting chemicals through a bio-analytical approach using DRE- and ERE-CALUX bioassays.

The Zenne River, crossing the Brussels region (Belgium) is an extremely urbanized river impacted by both domestic and industrial effluents. The objective of this study was to monitor the occurrence and activity of Endocrine Active Substances (EAS) in river water and sediments in the framework of the Environmental Quality Standards Directive (2008/105/EC and 2013/39/EU). Activities were determined using Estrogen and Dioxin Responsive Elements (ERE and DRE) Chemical Activated Luciferase Gene Expression (CALUX) bioassays. A potential contamination source of estrogen active compounds was identified in the river at an industrial area downstream from Brussels with a peak value of 938 pg E2 eq./L water (above the EQS of 0.4 ng/L) and 195 pg E2 eq./g sediment. Estrogens are more abundantly present in the sediments than in the dissolved phase. Principal Component Analysis (PCA) showed high correlations between Suspended Particulate Matter (SPM), Particulate (POC) and Dissolved Organic Carbon (DOC) and estrogenic EAS. The dioxin fractions comply with previous data and all were above the United States Environmental Protection Agency (US EPA) low-level risk, with one (42 pg TCDD eq./g sediment) exceeding the high-level risk value for mammals. The self-purifying ability of the Zenne River regarding estrogens was examined with an in vitro biodegradation experiment using the bacterial community naturally present in the river. Hill coefficient and EC50 values (Effective Concentration at 50%) revealed a process of biodegradation in particulate and dissolved phase. The estrogenic activity was decreased by 80%, demonstrating the ability of self-purification of estrogenic compounds in the Zenne River.

Characterisation and implementation of the ERE-CALUX bioassay on indoor dust samples of kindergartens to assess estrogenic potencies.

Estrogen-like endocrine disrupting chemicals (EEDCs) can be found abundantly in the environment. Due to their low-dose effects and the large amount of unknown EEDCs, it is difficult to assess and manage possible human health risks. For young children, who are particularly vulnerable to endocrine disruption due to their development rate, indoor dust is one of the main routes of exposure. In this study, an estrogen responsive elements chemically activated luciferase gene expression (ERE-CALUX) bioassay was characterized and implemented for the analysis of 12 dust samples from kindergartens in Flanders and Brussels (Belgium). The human ovarian carcinoma BG 1CALUX cell line showed reproducible results and a low limit of detection (LOD). The effective concentration at 50% of the maximum response (EC50) yielded 497 fg/well, while the LOD was 16 fg/well. For all dust samples, full dose-response curves and their corresponding EC50 values could be calculated. All samples yielded bio-analytical equivalent concentrations (BEQs) that were significantly higher than the procedural blank level and ranged from 426 to 8710 pg E2 equivalents/g dust. A clear relationship was observed between a semi-quantitative interior score and the ERE-CALUX response of the samples. In addition, the concentration of phthalates, a major group of EEDCs used as plasticizers in plastics, was determined in the samples by GC-MS. Diisoheptyl phthalate (DiHP) and di(2-ethylhexyl) phthalate (DEHP) were present in every dust sample. A good correlation was found between ERE-CALUX activities and phthalate concentrations, when all phthalates except diisononyl phthalate (DiNP) and diisodecyl phthalate (DiDP), which do not bind to the estrogen receptor, were taken into account. This shows that the ERE-CALUX can provide relevant results concerning exposure to EEDCs from indoor dust. This article is part of a Special Issue entitled 'Endocrine disruptors & steroids'.

Dioxin levels in fertilizers from Belgium: determination and evaluation of the potential impact on soil contamination.

Dioxins are harmful persistent organic pollutants (POPs) to which humans are exposed mostly via the consumption of animal products. They can enter the food chain at any stage, including crop fertilization. Fertilizers belong to several categories: synthetic chemicals providing the essential elements (mostly N, P and K) that are required by the crops but also organic fertilizers or amendments, liming materials, etc. Ninety-seven samples of fertilizers were taken in Belgium during the year 2011 and analyzed after a soft extraction procedure for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) using GC-IDHRMS. Only small qualitative differences could be observed between the main fertilizer categories since the PCDD:PCDF:DL-PCB average ratio obtained with the results expressed in TEQ was often close to 30:30:40 (typically for sewage sludge) or 40:30:30 (typically for compost). The median dioxin levels determined were generally lower than recorded previously and were the highest for sewage sludge and compost (5.6 and 5.5 ng TEQ/kg dry weight (dw), respectively). The levels in other fertilizers were lower including manure for which the median value was only 0.2 ng TEQ/kg dw. Several fertilization scenarios relying on the use of those fertilizers were assessed taking into consideration the application conditions prevailing in Belgium. From this assessment it could be concluded that the contribution of fertilizers to the overall soil contamination will be low by comparison of other sources of contamination such as atmospheric depositions. At the field scale, intensive use of compost and sewage sludge will increase dramatically the dioxin inputs compared with other fertilization practices but this kind of emission to the soil will still be relatively low compared to the dioxin atmospheric depositions.

Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: correlation between the CALUX bioassay and GC-HRMS.

Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast, sensitive and inexpensive tool for the analysis of a high number of samples, the use of this technique in routine analysis of atmospheric deposition samples may be a valuable alternative for GC-HRMS. In this study, a validated CALUX method was used for the analysis of PCDD/Fs and dioxin-like PCBs in more than 90 atmospheric deposition samples for different locations in Flanders. The samples were taken in residential and agricultural areas, where a threshold limit of 21pgWHO-TEQm(-2)d(-1) for the sum of PCDD/Fs and dioxin-like PCBs was set, and in industrial zones and natural reserves, where no official threshold limit is available. The results from the Flemish measurement program showed correlation between CALUX and GC-HRMS for all the samples, originating from the different areas (R(2) of 0.81, 0.53 and 0.64 for dl-PCBs, PCDD/Fs and sum of both fractions, respectively). Median CALUX/GC-HRMS ratios of 2.0, 0.9 and 1.3 were reported for the PCDD/Fs, dioxin-like PCBs and the sum of both fractions, respectively. The results show that the CALUX bioassay is a valuable alternative tool for the classic GC-HRMS analysis of atmospheric deposition samples in the Flemish measurement network.

Quantification of PCDD/Fs and dioxin-like PCBs in small amounts of human serum using the sensitive H1L7.5c1 mouse hepatoma cell line: optimization and analysis of human serum samples from adolescents of the Flemish human biomonitoring program FLEHS II.

Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast and inexpensive tool for the throughput analysis of dioxin-like compounds in a large number of samples and requires only small sample volumes, the use of this technique in human biomonitoring programs provides a good alternative to GC-HRMS. In this study, a method for the separate analysis of PCDD/Fs and dioxin-like PCBs (dl-PCBs) in human serum with the new sensitive H1L7.5c1 mouse hepatoma cell line was optimized. Sample dilution factors of 5 and 2.4 were selected for routine analysis of respectively the PCDD/Fs and dl-PCBs. The validation studies showed that repeatability and within-lab reproducibility for the quality control (QC) standard were within the in-house criteria. A long-term within-lab reproducibility of 25% for the PCDD/F fraction and 41% for the dl-PCB fraction for the analysis of pooled serum samples, expressed as pg BEQ/g fat, was determined. CALUX recoveries of the spiked procedural blanks were within the acceptable in-house limits of 80-120% for both fractions and the LOQ was 30.3 pg BEQ/g fat for the PCDD/Fs and 14.5 pg BEQ/g fat for the dl-PCBs. The GC-HRMS recovery of a C13-spiked pooled serum sample was between 60 and 90% for all PCDD/F congeners and between 67 and 82% for the non-ortho PCBs. An adequate separation between both fractions was found. The CALUX/GC-HRMS ratio for a pooled serum sample was respectively 2.0 and 1.4 for the PCDD/Fs and the dl-PCBs, indicating the presence of additional AhR active compounds. As expected, a correlation was found between human serum samples analyzed with both the new H1L7.5c1 cell line and the more established H1L6.1c3 cell line. The geometric mean CALUX-BEQ values, reported for the adolescents of the second Flemish Environment and Health Study (FLEHS II) recruited in 2009-2010, were 108 (95% CI: 101-114) pg CALUX-BEQ/g fat for the PCDD/Fs and 32.1 (30.1-34.2) pg CALUX-BEQ/g fat for the dioxin-like PCBs.

Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: Optimization and validation of a new CALUX bioassay method.

Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast, sensitive and inexpensive tool for the analysis of a high number of samples, validation of new methods is urgently needed. In this study, a new method for the analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples with the CALUX bioassay was developed, optimized and validated. The method consists of 4 steps: filtration, extraction, clean up and bioassay analysis. To avoid the use of large amounts of toxic solvents, new techniques were used for filtration and extraction: a C18 filter was used instead of a liquid/liquid extraction and an Accelerated Solvent Extractor (ASE) was used instead of the traditional soxhlet extraction. After pre-oxidation of the sample extract, clean up was done using a multi-layer silica gel column coupled to a carbon column. The PCDD/F and PCB fractions were finally analyzed with the H1L7.5c1 and/or the H1L6.1c3 mouse hepatoma cell lines. The limit of quantification was 1.4pg CALUX-BEQm(-2)d(-1) for the PCBs and 5.6pgCALUX-BEQm(-2)d(-1) for the PCDD/Fs, when using the new sensitive H1L7.5c1 cell line. The GC-HRMS recovery for all PCDD/F congeners was between 55% and 112%, with a mean recovery of 90%. CALUX recoveries of spiked procedural blanks were between the accepted ranges of 80-120%. Repeatability and reproducibility were satisfactory and no interferences from metals were detected. The first results from the Flemish measurement program showed good correlation between CALUX and GC-HRMS.