Effect-directed analysis to explore the polar bear exposome: identification of thyroid hormone disrupting compounds in plasma

Compounds with transthyretin (TTR)-binding potency in the blood plasma of polar bear cubs were identified with effect-directed analysis (EDA). This approach contributes to the understanding of the thyroid disrupting exposome of polar bears. The selection of these samples for in-depth EDA was based on the difference between the observed TTR-binding potency on the one hand and the calculated potency (based on known concentrations of TTR-binding compounds and their relative potencies) on the other. A library-based identification was applied to the liquid chromatography-time-of-flight-mass spectrometry (LC-ToF-MS) data by screening for matches between compound lists and the LC-ToF-MS data regarding accurate mass and isotope pattern. Then, isotope cluster analysis (ICA) was applied to the LC-ToF-MS data allowing specific screening for halogen isotope patterns. The presence of linear and branched nonylphenol (NP) was observed for the first time in polar bears. Furthermore, the presence of one di- and two monohydroxylated octachlorinated biphenyls (octaCBs) was revealed in the extracts. Linear and branched NP, 4'-OH-CB201 and 4,4'-OH-CB202 could be successfully confirmed with respect to their retention time in the analytical system. In addition, branched NP, mono- and dihydroxylated-octaCBs showed TTR-binding potencies and could explain another 32 ± 2% of the total measured activities in the extracts.

Effects of complex organohalogen contaminant mixtures on thyroid homeostasis in hooded seal (Cystophora cristata) mother-pup pairs

Many lipid-soluble and phenolic compounds present in the complex mixture of orgaohalogen contaminants (OHCs) that arctic wildlife is exposed to have the ability to interfere with the thyroid hormone (TH) system. The aim of this study was to identify compounds that might interfere with thyroid homeostasis in 14 nursing hooded seal (Cystophora cristata) mothers and their pups (1-4d old) sampled in the West Ice in March 2008. Multivariate modelling was used to assess the potential effects of measured plasma levels of OHCs on circulating TH levels of the measured free (F) and total (T) levels of triidothyrine (T3) and thyroxine (T4). Biological factors were important in all models (e.g. age and sex). In both mothers and pups, TT3:FT3 ratios were associated with α- and β-hexachlorocyclohexane (HCH), ortho-PCBs, chlordanes and DDTs. The similarities between the modelled TT3:FT3 responses to OHC levels in hooded seal mothers and pups most probably reflects similar exposure patterns, but could also indicate interconnected TH responses. There were some differences in the modelled TH responses of mothers and pups. Most importantly, the negative relationships between many OH-PCBs (particularly 3'-OH-CB138) and TT3:FT3 ratio and the positive relationships between TT4:FT4 ratios and polybrominated diphenyl ether [PBDE]-99, -100 and 4-OH-CB107 in pups, which was not found in mothers. Although statistical associations are not evidence per se of biological cause-effect relationships, the results suggest that thyroid homeostasis is affected in hooded seals, and that the inclusion of the fullest possible OHC mixture is important when assessing TH related effects in wildlife.

Transthyretin-binding activity of contaminants in blood from polar bear (Ursus maritimus) cubs

We determined the transthyretin (TTR)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (Ursus maritimus) cubs from Svalbard sampled in 1998 and 2008. The TTR-binding activity was measured as thyroxine (T4)-like equivalents (T4-EQMeas). Our findings show that the TTR-binding activity related to contaminant levels was significantly lower (45%) in 2008 than in 1998 (mean ± standard error of mean: 1998, 2265 ± 231 nM; 2008, 1258 ± 170 nM). Although we cannot exclude a potential influence of between-year differences in capture location and cub body mass, our findings most likely reflect reductions of TTR-binding contaminants or their precursors in the arctic environment (e.g., polychlorinated biphenyls [PCBs]). The measured TTR-binding activity correlated positively with the cubs' plasma levels of hydroxylated PCBs (OH-PCBs). No such association was found between TTR-binding activity and the plasma levels of perfluoroalkyl substances (PFASs). The OH-PCBs explained 60 ± 7% and 54 ± 4% of the TTR-binding activity in 1998 and 2008, respectively, and PFASs explained ≤1.2% both years. Still, almost half the TTR-binding activity could not be explained by the contaminants we examined. The considerable levels of TTR-binding contaminants warrant further effect directed analysis (EDA) to identify the contaminants responsible for the unexplained part of the observed TTR-binding activity.

Should modern imaging be part of remission criteria in rheumatoid arthritis?

With recent improvements in the treatment of rheumatoid arthritis (RA), remission has become an achievable goal for a large proportion of RA patients, and remission is now a defined target in current RA guidelines. However, studies have shown that progression of radiographic joint damage may occur in clinical remission, regardless of the choice of remission definition. Sub-clinical inflammation detected by modern imaging techniques such as ultrasonography and magnetic resonance imaging is present in the majority of patients in clinical remission, and is associated with progressive joint damage and disease activity flare in these patients. This chapter aims to assess the importance of imaging findings in RA patients in clinical remission and to discuss the possible role of modern imaging in future remission criteria.

High prevalence of infections and pathological changes in burbot (Lota lota) from a polluted lake (Lake Mjøsa, Norway)

The aim of the present study was to investigate whether exposure to high levels of persistent organic pollutants (POPs) affected a fish population in Lake Mjøsa. Lake Mjøsa is known to be contaminated by polybrominated diphenyl ethers (PBDEs), a subgroup of brominated flame retardants from local industrial activities. Fish from Lake Losna, a less contaminated lake located close to Lake Mjøsa, was used as reference (control). The sampling of burbot (Lota lota) was carried out between 2005 and 2008. Hepatic levels of POPs were analysed in burbot from the two lakes, and the fish were examined for bacterial- and parasite infection and histopathological changes. The levels of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), and PBDEs were about 10, 15 and 300 times higher in fish from Lake Mjøsa compared to fish from Lake Losna. Mycobacterium salmoniphilum was present in 7% and 35% of the fish from Lake Losna and Lake Mjøsa respectively. Significantly higher number of external and visceral macroscopic lesions, histopathological diffuse changes and granulomas were seen in fish from Lake Mjøsa compared to Lake Losna. Furthermore the parasite infection was higher and the hepatic lipid content was significantly lower in burbot from Lake Mjøsa. The results of the present study suggest that the high level of contamination in Lake Mjøsa could have a negative impact on the health status of wild fish inhabiting the lake.

Construct and criterion validity of several proposed DAS28-based rheumatoid arthritis flare criteria: an OMERACT cohort validation study

BACKGROUND

To describe rheumatoid arthritis (RA) worsening that leads to change or re-initiation of treatment, several Disease Activity Score 28 (DAS28)-based flare criteria have been described, but none validated.

METHODS

Six previously published DAS28-based flare criteria ((1) increase in DAS28 >1.2, or >0.6 if DAS28 >5.1; (2) increase in DAS28 >1.2, or >0.6 if DAS28 ≥3.2; (3) increase >0.6 or DAS28 >3.2; (4) increase in DAS28 >1.2; (5) DAS28 >3.2; (6) DAS28 >2.6) were tested against five hypotheses concerning criterion and construct validity: (1+2) Sensitivity and specificity >70% compared with patient's/physician's judgment; (3) difference in proportion with disease modifying anti-rheumatic drug/corticosteroid initiation/increase >0.2; (4) mean difference in C-reactive protein (CRP) >10 mg/l; and (5) no statistical difference in Short Form-36 Mental Health subscale change. Three different RA patient databases in which flare might occur were used. Sensitivity/specificity, χ(2) and two-sample student t test analyses were done.

RESULTS

The analyses included 51, 147 and 744 RA patients, from the three databases. Criterion 2 fulfilled most hypotheses: 4 out of 5. Sensitivity and specificity varied between 63%-78% and 84%-92%. Construct validity was demonstrated with 23% more treatment change, higher mean CRP (11.4 mg/l) and depression scale change of -5. Criteria 3, 5 and 6 were more sensitive, criteria 1, 2 and 4 more specific.

CONCLUSIONS

An increase in DAS28 >1.2 or >0.6 if DAS28 ≥3.2 appears most discriminating and valid by our predefined validation criteria. Considering the other criteria, sensitivity and specificity shown here might facilitate use in different settings.

Perfluoroalkyl substances in polar bear mother-cub pairs: a comparative study based on plasma levels from 1998 and 2008

Perfluoroalkyl substances (PFASs) are protein-binding blood-accumulating contaminants that may have detrimental toxicological effects on the early phases of mammalian development. To enable an evaluation of the potential health risks of PFAS exposure for polar bears (Ursus maritimus), an exposure assessment was made by examining plasma levels of PFASs in polar bear mothers in relation to their suckling cubs-of-the-year (~4 months old). Samples were collected at Svalbard in 1998 and 2008, and we investigated the between-year differences in levels of PFASs. Seven perfluorinated carboxylic acids (∑₇PFCAs: PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA) and two perfluorinated sulfonic acids (∑₂PFSAs: PFHxS and PFOS) were detected in the majority of the mothers and cubs from both years. In mothers and cubs, most PFCAs were detected in higher concentrations in 2008 than in 1998. On the contrary, levels of PFOS were lower in 2008 than in 1998, while levels of PFHxS did not differ between the two sampling years. PFOS was the dominating compound in mothers and cubs both in 1998 and in 2008. Concentration of PFHpA did not differ between mothers and cubs, while concentrations of PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFHxS, and PFOS were higher in mothers than in their cubs. Except from PFHpA, all compounds correlated significantly between mothers and their cubs. The mean cub to mother ratios ranged from 0.15 for PFNA to 1.69 for PFHpA. On average (mean±standard error of mean), the levels of ∑₇PFCAs and ∑₂PFSAs in cubs were 0.24±0.01 and 0.22±0.01 times the levels in their mothers, respectively. Although maternal transfer appears to be a substantial source of exposure for the cubs, the low cub to mother ratios indicate that maternal transfer of PFASs in polar bears is relatively low in comparison with hydrophobic contaminants (e.g. PCBs). Because the level of several PFASs in mothers and cubs from both sampling years exceeded the levels associated with health effects in humans, our findings raise concern on the potential health effects of PFASs in polar bears from Svalbard. Effort should be made to examine the potential health effects of PFASs in polar bears.

Mercury in molar excess of selenium interferes with thyroid hormone function in free-ranging freshwater fish

Thyroid hormones (THs) are essential for cellular metabolism, somatic growth and development, and reproduction. Mercury (Hg) entering aquatic systems and accumulated as highly toxic methylmercury (MeHg) represents a threat to wildlife and human health. Selenium (Se) is an essential element critical for TH activation and regulation. In organisms, binding of Hg in a Se-Hg complex results in a detoxification of Hg. However, formation of Se-Hg complexes also affects Se bioavailability, disrupting functions of Se-dependent enzymes, such as TH deiodinases, which convert thyroxine (T4) to the physiologically active TH, triiodothyronine (T3). The main aim of the present study was to investigate how tissue Se:Hg molar ratios, tissue levels of Se and Hg, and other potential TH disruptive contaminants (metals and organic chemical compounds) affect plasma TH levels in free-ranging brown trout, Salmo trutta , from Lake Mjøsa (a Se-deprived lake) and Lake Losna (a reference lake), Norway. Among the wide range of potential TH disruptive pollutants investigated, tissue Se:Hg molar ratios in muscle and liver were the most significant predictors of plasma TH levels in the trout. Moreover, lower plasma levels of the biological active hormone, T3, in the Lake Mjøsa trout co-occurred with their low Se:Hg molar ratios. This suggests that Se availability is impaired by Hg and results in altered selenoenzyme activities and loss of optimal control of TH balance in free-ranging freshwater fish.

Multinational evidence-based recommendations for pain management by pharmacotherapy in inflammatory arthritis: integrating systematic literature research and expert opinion of a broad panel of rheumatologists in the 3e Initiative

OBJECTIVE

To develop evidence-based recommendations for pain management by pharmacotherapy in patients with inflammatory arthritis (IA).

METHODS

A total of 453 rheumatologists from 17 countries participated in the 2010 3e (Evidence, Expertise, Exchange) Initiative. Using a formal voting process, 89 rheumatologists representing all 17 countries selected 10 clinical questions regarding the use of pain medications in IA. Bibliographic fellows undertook a systematic literature review for each question, using MEDLINE, EMBASE, Cochrane CENTRAL and 2008-09 European League Against Rheumatism (EULAR)/ACR abstracts. Relevant studies were retrieved for data extraction and quality assessment. Rheumatologists from each country used this evidence to develop a set of national recommendations. Multinational recommendations were then formulated and assessed for agreement and the potential impact on clinical practice.

RESULTS

A total of 49,242 references were identified, from which 167 studies were included in the systematic reviews. One clinical question regarding different comorbidities was divided into two separate reviews, resulting in 11 recommendations in total. Oxford levels of evidence were applied to each recommendation. The recommendations related to the efficacy and safety of various analgesic medications, pain measurement scales and pain management in the pre-conception period, pregnancy and lactation. Finally, an algorithm for the pharmacological management of pain in IA was developed. Twenty per cent of rheumatologists reported that the algorithm would change their practice, and 75% felt the algorithm was in accordance with their current practice.

CONCLUSIONS

Eleven evidence-based recommendations on the management of pain by pharmacotherapy in IA were developed. They are supported by a large panel of rheumatologists from 17 countries, thus enhancing their utility in clinical practice.

Eggshell thinning and decreased concentrations of vitamin E are associated with contaminants in eggs of ivory gulls

The ivory gull is a high Arctic seabird species threatened by climate change and contaminant exposure. High levels of contaminants have been reported in ivory gull Pagophila eburnea eggs from Svalbard and the Russian Arctic. The present study investigated associations between high levels of contaminants (organochlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), brominated flame retardants (BFRs), perfluorinated alkyl substances (PFASs) and mercury (Hg)) and three response variables: eggshell thickness, retinol (vitamin A) and α-tocopherol (vitamin E). Negative associations were found between levels of OCPs, PCBs and BFRs and eggshell thickness (p<0.021) and α-tocopherol (p<0.023), but not with retinol (p>0.1). There were no associations between PFASs and mercury and the three response variables. Furthermore, the eggshell thickness was 7-17% thinner in the present study than in archived ivory gull eggs (≤1930). In general, a thinning above 16 to 20% has been associated with a decline in bird populations, suggesting that contaminant-induced eggshell thinning may constitute a serious threat to ivory gull populations globally.

Latitudinal distribution of persistent organic pollutants in pelagic and demersal marine fish on the Norwegian Coast

The latitudinal distribution of persistent organic pollutants (POPs: legacy organochlorines [OCs], polybrominated diphenyl ethers [PBDEs,] and hexabromocyclododecane [HBCD]) was examined in livers of two species of marine fish, the pelagic saithe (Pollachius virens,n = 40) and the demersal cod (Gadus morhua,n = 40), along a south-north gradient (59°-70°N) on the Norwegian Coast. Cod had in general two to three times higher concentrations of POPs than saithe, probably because of higher exposure in the benthic food chain. The concentrations of heavy halogenated compounds were higher in the southernmost region than further north. Moreover, the POP pattern showed a gradual shift in the compositions from south to north, especially for OCs in cod: i.e. the relative importance of low-chlorinated polychlorinated biphenyl (PCB) congeners and some OC-pesticides (e.g., hexachlorobenzen [HCB]) in the contaminant burdens increased with latitude. The latitudinal fractionation signal was weaker in saithe, possibly due to its pelagic and nomadic behavior. Hence, this study shows not only a strong latitudinal fractionation in the compositional patterns of POPs in marine fish but also the effects of habitat use and fish behavior.

PCBs and OH-PCBs in polar bear mother-cub pairs: a comparative study based on plasma levels in 1998 and 2008

The aim of this study was to examine the plasma concentrations and prevalence of polychlorinated biphenyls (PCBs) and hydroxylated PCB-metabolites (OH-PCBs) in polar bear (Ursus maritimus) mothers (n=26) and their 4 months old cubs-of-the-year (n=38) from Svalbard to gain insight into the mother-cub transfer, biotransformation and to evaluate the health risk associated with the exposure to these contaminants. As samplings were performed in 1997/1998 and 2008, we further investigated the differences in levels and pattern of PCBs between the two sampling years. The plasma concentrations of Σ(21)PCBs (1997/1998: 5710 ± 3090 ng/g lipid weight [lw], 2008: 2560 ± 1500 ng/g lw) and Σ(6)OH-PCBs (1997/1998: 228 ± 60 ng/g wet weight [ww], 2008: 80 ± 38 ng/g ww) in mothers were significantly lower in 2008 compared to in 1997/1998. In cubs, the plasma concentrations of Σ(21)PCBs (1997/1998: 14680 ± 5350 ng/g lw, 2008: 6070 ± 2590 ng/g lw) and Σ(6)OH-PCBs (1997/1998: 98 ± 23 ng/g ww, 2008: 49 ± 21 ng/g ww) were also significantly lower in 2008 than in 1997/1998. Σ(21)PCBs in cubs was 2.7 ± 0.7 times higher than in their mothers. This is due to a significant maternal transfer of these contaminants. In contrast, Σ(6)OH-PCBs in cubs were approximately 0.53 ± 0.16 times the concentration in their mothers. This indicates a lower maternal transfer of OH-PCBs compared to PCBs. The majority of the metabolite/precursor-ratios were lower in cubs compared to mothers. This may indicate that cubs have a lower endogenous capacity to biotransform PCBs to OH-PCBs than polar bear mothers. Exposure to PCBs and OH-PCBs is a potential health risk for polar bears, and the levels of PCBs and OH-PCBs in cubs from 2008 were still above levels associated with health effects in humans and wildlife.

Effectiveness of sulfasalazine and methotrexate in 1102 DMARD-naive patients with early RA

OBJECTIVE

To compare baseline characteristics, responses and drug survival in patients with early RA starting SSZ or MTX in a real-life setting.

METHODS

The analyses included DMARD-naïve patients with RA (disease duration ≤ 1 year) starting SSZ or MTX. Three- and 6-month effectiveness was compared by unadjusted analysis and with adjustment for propensity score quintile. In addition, effectiveness in SSZ- and MTX-treated patients matched for RF status and baseline DAS-28 was compared.

RESULTS

SSZ-treated patients (n = 175) had lower baseline disease activity than patients treated with MTX (n = 927) [mean 28-joint DAS (DAS-28) 4.4 vs 5.0, P < 0.001], and were less often RF positive (50 vs 61%, P = 0.006). Six-month mean ΔDAS-28 was smaller with SSZ than MTX (-1.0 vs -1.5, P = 0.003); the difference was not significant after adjustment for propensity score quintile (P = 0.36). For SSZ/MTX, 3-month ACR50 and European League Against Rheumatism (EULAR) good responses were 9/23% (P < 0.001) and 24/31% (P = 0.14), respectively. Three-year drug survival was superior for MTX (P < 0.001) and estimated 1-year survival rates were 42/75% for SSZ/MTX. In patients matched for baseline DAS-28 and RF, mean ΔDAS-28 (MTX -1.2, P = 0.55 vs SSZ) and EULAR good responses (39 vs 37%, P = 0.74) were similar at 6 months; drug survival was superior for MTX (P < 0.001).

CONCLUSION

Patients treated with SSZ as first DMARD were more often RF negative and had lower baseline disease activity. Drug survival was superior for MTX, and effectiveness was greater with MTX than with SSZ although the difference was reduced when adjusting for differences in baseline characteristics.

Effectiveness of disease-modifying antirheumatic drug co-therapy with methotrexate and leflunomide in rituximab-treated rheumatoid arthritis patients: results of a 1-year follow-up study from the CERERRA collaboration

OBJECTIVES

To compare the effectiveness and safety of rituximab alone or in combination with either methotrexate or leflunomide.

METHODS

10 European registries submitted anonymised datasets with baseline, 3, 6, 9 and 12-month clinical data from patients who started rituximab.

RESULTS

1195 patients were treated with rituximab plus methotrexate, 177 with rituximab plus leflunomide and 505 with rituximab alone. Significantly more patients achieved a European League Against Rheumatism good response at 6 months when treated with rituximab plus leflunomide (29.1%) compared with rituximab plus methotrexate (21.1%) and rituximab alone (19.3%; p=0.02 and p=0.01, respectively). Similar results were observed at 12 months. Adverse events occurred in 10.2%, 13.2% and 13.9% of patients on rituximab plus leflunomide, rituximab plus methotrexate and rituximab alone, respectively.

CONCLUSIONS

Leflunomide is an effective and safe alternative to methotrexate as concomitant treatment with rituximab. Slightly better results were obtained by the combination of rituximab and leflunomide than rituximab and methotrexate, raising the possibility of a synergistic effect of leflunomide and rituximab.

Levels and patterns of hydroxylated polychlorinated biphenyls (OH-PCBs) and their associations with thyroid hormones in hooded seal (Cystophora cristata) mother-pup pairs

Blood (plasma/serum) samples from 14 adult female and their pups (1-4 days old) captured in the West Ice, east of Greenland were analysed for concentrations of total and free thyroxine and triiodothyronine (TT4, FT4, TT3, FT3), and hydroxylated polychlorinated biphenyls (OH-PCBs). The levels of all thyroid hormones (THs) were significantly higher in pups than in mothers. Sum OH-PCB levels (ΣOH-PCBs: 4-OH-CB107, 3'-OH-CB138, 4-OH-CB146, 4'-OH-CB172, 4-OH-CB187) were significantly higher in mothers (3.98 ± 1.55 pmol/g; 1.40 ± 0.54 ng/g wet weight) as compared to pups (1.95 ± 0.78 pmol/g; 0.68 ± 0.28 ng/g wet weight). Plasma levels of TT4 and FT4 in mothers increased as a function of pup age, as did levels of individual OH-PCBs in both mothers and pups. The pattern of OH-PCBs in the pups was similar to their mothers. We suggest that OH-PCBs found in pups are transferred from their mothers during gestation and that the transfer also continues after parturition via milk. Principal component analysis (PCA) showed that in pups, 4-OH-CB107 and 3'-OH-CB138 were negatively associated with FT4:FT3 and TT3:FT3 ratios, respectively. These relationships were confirmed by partial correlation analysis correcting for pup age. PCA suggested that 4'-OH-CB172 and 4-OH-CB187 were negatively associated with TT3 in mothers. However, this was not confirmed by correlation tests. Although statistical relationships should be interpreted with caution, the study indicates that young developing seals are more sensitive compared to adults with respect to TH-related effects of OH-PCBs.

Trophic level determines levels of brominated flame-retardants in coastal herring gulls

Liver concentrations of eight polybrominated diphenyl ethers (ΣPBDEs: sum of brominated diphenyl ethers [BDE]-28, -47, -99, -100, -153, -154, -183, and -209) ranged from 135 to 985 ngg(-1) lipid weight (lw) in coastal herring gulls (Larus argentatus) from the marine Hvaler Archipelago (The Glomma River Estuary), Norway. Hexabromocyclododecane (HBCD) concentrations ranged from 10 to 698 ngg(-1)lw. High range in δ(13)C indicates that gulls were subject to a diversity of carbon sources, likely reflecting their mixed feeding on terrestrial and marine organisms, or diversity of autochthonous and allochthonous (watershed) energy sources at the bases of their marine/estuarial food chains. Inverse relationships of HBCD, and to somewhat lesser extent of BDE-209, with δ(13)C values suggest higher abundance of these compounds in the land-derived energy-sources of the gulls. Inverse relationships of BDE-99, BDE-183 and BDE-209 with δ(15)N suggest that trophic relationships affect bioaccumulation of these compounds in the herring gulls, with greater bioaccumulation from lower trophic level prey species. This may be because these PBDE congeners are subject of debromination in higher trophic levels prey species of the gulls (e.g., teleost fish). Levels of BDE-209 (up to 95 ng/g lipid) of these herring gulls from 1998 were in the higher range reported in European birds, and not matched by other reports in North Sea seabirds. The present study suggests that the currently used brominated flame-retardants (BFRs), BDE-209 and HBCD relate to changing nutrient allocation in the herring gulls, and represent a risk to seabirds exploiting near-shore and estuary ecosystems.

Blood plasma sample preparation method for the assessment of thyroid hormone-disrupting potency in effect-directed analysis

A sample preparation method combining solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was developed to be used in Effect-Directed Analysis (EDA) of blood plasma. Until now such a method was not available. It can be used for extraction of a broad range of thyroid hormone (TH)-disruptors from plasma with high recoveries. Validation of the method using spiked cow plasma showed good recoveries for hydroxylated polybrominated diphenyl ethers (OH-PBDEs; 93.8 ± 19.5%), hydroxylated polychlorinated biphenyls (OH-PCBs; 93.8 ± 15.5%), other halogenated phenols (OHPs; 107 ± 8.1%), and for short-chain (<8 C-atoms) perfluoroalkyl substances (PFASs; 85.2 ± 24.6%). In the same extracts, the potency of the compound classes spiked to the cow plasma to competitively bind to transthyretin (TTR) was recovered by 84.9 ± 8.8%. Furthermore, the SPE-LLE method efficiently removed endogenous THs from the extracts, thereby eliminating their possible contribution to the binding assay response. The SPE-LLE method was applied to polar bear plasma samples to investigate its applicability in future EDA studies focusing on TH-disrupting compounds in this top predator species that is exposed to relatively high levels of bioaccumulating pollutants. A first screening revealed TTR-binding potency in the polar bear plasma extracts, which could be explained for 60-85% by the presence of OH-PCBs.

Disruptive effects of persistent organohalogen contaminants on thyroid function in white whales (Delphinapterus leucas) from Svalbard

We analysed levels of 56 organohalogen contaminants (OHCs) including brominated flame retardants, polychlorinated biphenyls (PCBs), and organochlorine pesticides in the blubber of white (beluga) whales (Delphinapterus leucas) from Svalbard, Norway (N=12; 6 adults [5 males and 1 female] and 6 subadults [4 males and 2 females]) collected in 1996-2001. We also measured circulating levels of thyroid hormones (THs) and thyroid stimulating hormone (TSH) in the whales. The results confirm that OHC levels in these white whales are among the highest levels recorded in wildlife from Svalbard, and at the high end of the range when compared to white whales from the North American Arctic. A projection to latent structure (PLS) model (subadults and adult males grouped together) revealed that known or suspected thyroid disruptive contaminants (polybrominated diphenylether [PBDE]-28, -47, -99, -100, and -154, hexachlorobenzene [HCB], and PCB-105) were negatively correlated with circulating levels of total thyroxin (TT4), free T4 (FT4) and free triiodothyronine (FT3). Most of these negative relationships were also confirmed using partial correlations controlling for length (and thus age) of the whales. The positive correlations of TT4, FT4 and FT3 with hexabromocyclododecane (HBCD), α-hexachlorocyclohexane (α-HCH), chlorinated bornanes CHB-40 and CHB-62 revealed by the PLS model were not confirmed by partial correlations. TH levels in the present study appeared to be somewhat lower than levels measured in beluga whales from the Canadian Arctic. However, we were not able to determine if this was caused by different levels of OHCs, or differences in biological factors (e.g. age, sex, moulting status, and season) and analytical methods between the studies. Although the sample sizes were low and statistical models cannot depict the biological cause-effect relationships, this study suggests negative influences of specific OHCs, particularly PBDEs, on thyroid hormone levels in white whales. The impact this might have on individual and population health is unknown.

Highest clinical effectiveness of rituximab in autoantibody-positive patients with rheumatoid arthritis and in those for whom no more than one previous TNF antagonist has failed: pooled data from 10 European registries

OBJECTIVE

To assess the 6-month effectiveness of the first rituximab (RTX) course in rheumatoid arthritis (RA) and to identify possible predictors of response.

METHOD

10 European registries submitted anonymised datasets (baseline, 3- and 6-month follow-up) from patients with RA who had started RTX, and datasets were pooled and analysed. Heterogeneity between countries was analysed by analysis of variance. Predictors of response were identified by logistic regression.

RESULTS

2019 patients were included (mean age/disease duration 53.8/12.1 years, 80.3% female, 85.6% rheumatoid factor (RF) positive and 76.8% (456/594 patients) anti-cyclic citrullinated peptide antibodies (anti-CCP) positive). For these patients an average of 2.7 disease-modifying antirheumatic drugs (DMARDs) (range 0-10) had failed, and RTX was given as the first biological agent in 36.6% of patients. There was significant heterogeneity between countries for several baseline characteristics, including the number of previous biological agents. Disease Activity Score based on 28 joint counts (DAS28) decreased from 5.8±1.4 at baseline to 4.2±1.4 at 6 months (p<0.0001) and 22.2%/42.5% achieved European League Against Rheumatism (EULAR) good/moderate response. Larger 6-month improvement in DAS28 was observed in RF-positive and anti-CCP-positive versus seronegative patients. The following predictors of EULAR good response at 6 months were identified in a multivariate analysis: anti-CCP positivity (OR=2.86, p=0.003), number of previous DMARDs (OR=0.84, p=0.06), ≤1 previous biological agents (OR=1.89, p=0.04), baseline DAS28 level (OR=0.74, p=0.003).

CONCLUSION

In this large observational cohort of patients with RA treated with RTX, seropositive patients achieved significantly greater reductions in DAS28 at 6 months than seronegative patients. Effectiveness was best when RTX was used as the first biological agent or after failure of no more than one anti-tumour necrosis factor agent.

Accumulation and effects of natural mixtures of persistent organic pollutants (POP) in Zebrafish after two generations of exposure

Effects of exposure to environmentally realistic mixtures of persistent organic pollutants (POP) harvested from aquatic ecosystems in Norway were studied in an in vivo zebrafish model. POP were extracted from burbot (Lota lota) liver from two separate lakes, Lake Losna and Lake Mjøsa, and exposed to zebrafish through the diet in a two-generation study. Effects on survival, growth, sex ratio, and timing of puberty were investigated. In addition, the biomarkers 7-ethoxyresorufin O-deethylase (EROD) and vitellogenin (Vtg) were measured. The ratios of contaminant levels in extracts collected from Lake Mjøsa:Lake Losna were 6, 10, and 270 for polychlorinated biphenyls (PCB), dichlorodiphenyltrichloroethanes (DDT), and polybrominated diphenyl ethers (PBDE), respectively. The concentration range of POP measured in zebrafish was lower than in burbot originating from Lake Mjøsa, but comparable to concentrations previously reported in humans and wildlife. The results showed that exposure to environmentally realistic mixtures of POP exerted a negative effect on survival of fish in both generations. The marked drop in survival during 9-20 days post fertilization (dpf) suggested that this period may be a critical window for development. In both generations an earlier onset of puberty was observed and a higher proportion of males than females was noted in exposed fish compared to controls. Suprising effects of exposure were found on body weight. In the first generation (F(0)), body weight was significantly higher in both exposure groups compared to controls, while in the next generation (F(1)) the same exposures were associated with a decrease in body weight. Zebrafish exposed to relatively low quantities of POP showed a significant induction of biomarkers (EROD and Vtg), while fish exposed to higher exposure doses did not demonstrate induction.

Salmon farms as a source of organohalogenated contaminants in wild fish

Organohalogenated contaminants (OHCs), including organochlorines (OCs; PCB, and OC-pesticides), brominated flame retardants (BFRs; polybrominated diphenyl ethers [PBDE], hexabromocyclododecane [HBCD]) and perfluorooctane sulfonate (PFOS), were measured in livers of Atlantic cod (Gadus morhua) and saithe (Pollachius virens) caught in the vicinity of salmon farms (n = 75) and control sites (n = 80) in three regions (59°-70°N) in Norway. Forty-five percent of the farm-associated (FA) fish (60% of the saithe and 30% of the cod) and none of the control fish had salmon feed (aquaculture food pellets) in their digestive tracts. Concentrations of OCs and BFRs were about 50% higher and dominated more by persistent compounds in Atlantic cod compared to saithe. After controlling for a set of confounding variables (location, sex, size, weight, gonads size, hepatosomatic index, and % lipids in the liver), the concentrations of ∑OC and ∑BDE were 50% higher in FA cod compared to control fish, whereas they were 20% higher in FA saithe than control fish. Hence, salmon farms are a source of lipid-soluble OHCs to wild marine fish, but variation in life-history and habitat use seems to affect the levels of OHCs in the different fish species. In contrast to the lipid-soluble OHCs, control fish had 67% higher PFOS levels than FA fish, which suggests that natural food contains higher loads of this compound than the commercial feed used in salmon farms. Some OHCs are known to act as endocrine disruptors, thus further work is required to determine if OHCs negatively affect reproductive processes of wild fish associated with salmon farms.

Ankylosing Spondylitis Disease Activity Score (ASDAS): defining cut-off values for disease activity states and improvement scores

BACKGROUND

The Ankylosing Spondylitis Disease Activity Score (ASDAS) is a new composite index to assess disease activity in ankylosing spondylitis (AS). It fulfils important aspects of truth, feasibility and discrimination. Criteria for disease activity states and improvement scores are important for use in clinical practice, observational studies and clinical trials and so far have not been developed for the ASDAS.

OBJECTIVE

To determine clinically relevant cut-off values for disease activity states and improvement scores using the ASDAS.

METHODS

For the selection of cut-offs data from the Norwegian disease modifying antirheumatic drug (NOR-DMARD) registry, a cohort of patients with AS starting conventional or biological DMARDs, were used. Receiver operating characteristic analysis against several external criteria was performed and several approaches to determine the optimal cut-offs used. The final choice was made on clinical and statistical grounds, after debate and voting by Assessment of SpondyloArthritis international Society members. Crossvalidation was performed in NOR-DMARD and in Ankylosing Spondylitis Study for the Evaluation of Recombinant Infliximab Therapy, a database of patients with AS participating in a randomised placebo-controlled trial with a tumour necrosis factor blocker.

RESULTS

Four disease activity states were chosen by consensus: inactive disease, moderate, high and very high disease activity. The three cut-offs selected to separate these states were: 1.3, 2.1 and 3.5 units. Selected cut-offs for improvement were: change ≥1.1 units for clinically important improvement and change ≥2.0 units for major improvement. Results of the crossvalidation strongly supported the cut-offs.

CONCLUSIONS

Cut-off values for disease activity states and improvement using the ASDAS have been developed. They proved to have external validity and a good performance compared to existing criteria.

Distribution of PCB 118 and PCB 153 and hydroxylated PCB metabolites (OH-CBs) in maternal, fetal and lamb tissues of sheep exposed during gestation and lactation

The main objective of the present study was to gain knowledge about the disposition of the PCB congeners 118 and 153 in a sheep model where ewes were given oral doses of PCB in two consecutive gestations. The study aimed to investigate how maternal exposure with PCBs affected tissue concentrations in lambs and fetuses and to carry out time trend studies in ewes between gestations, as well as to increase the knowledge on metabolic processes by studying OH-metabolites. The results showed that the fetuses accumulated PCBs in levels and composition comparable to the ewes. The mean fetus/mother ratios of adipose tissue levels ranged from 0.71 to 0.82 for both PCB 118 and PCB 153 in the two exposure groups. Furthermore, the fetal brain/fat ratios ranged from 0.15 to 0.20 for both congeners. Body burden calculations (BB) showed that 16% and 43% of the total PCB 118 and PCB 153, respectively, still remained in ewes, lambs and fetuses after exposure during two gestations. The different accumulation of the two congeners is assumed to be a result of differences in metabolism. The present study demonstrate that high levels of PCB 118 and PCB 153 cross the placenta and accumulate in the fetal adipose tissue and brain thus exposing the fetus during vulnerable periods of extensive development.

In vitro assay shows that PCB metabolites completely saturate thyroid hormone transport capacity in blood of wild polar bears (Ursus maritimus)

Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (PCBs) are the most concentrated pollutant class in polar bears (Ursus maritimus). Metabolism of PCB and polybrominated biphenyl ether (PBDE) flame-retardants alter their toxicological properties and these metabolites are known to interfere with the binding of thyroid hormone (TH) to transthyretin (TTR) in rodents and humans. In polar bear plasma samples no binding of [125I]-T(4) to TTR was observed after incubation and PAGE separation. Incubation of the plasma samples with [14C]-4-OH-CB107, a compound with a higher binding affinity to TTR than the endogenous ligand T(4) resulted in competitive binding as proven by the appearance of a radio labeled TTR peak in the gel. Plasma incubation with T(4) up to 1 mM, a concentration that is not physiologically relevant anymore did not result in any visible competition. These results give evidence that the binding sites on TTR for T(4) in wild living polar bears are completely saturated. Such saturation of binding sites can explain observed lowered levels of THs and could lead to contaminant transport into the developing fetus.

Identification of cutpoints for acceptable health status and important improvement in patient-reported outcomes, in rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis

OBJECTIVE

To identify cutpoints reflecting Patient Acceptable Symptom State (PASS) and Minimal Clinically Important Improvement (MCII) in patient-reported multi-attribute health status classification systems and health status measurements among patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA).

METHODS

We identified patients with RA, AS, and PsA from the Norwegian disease-modifying antirheumatic drug (DMARD) register (NOR-DMARD). The patients (n = 4225) had started with DMARD and responded to the PASS and MCII anchoring questions at the 3-month followup examination. Receiver operating characteristics (ROC) curves with 80% specificity and the 75th percentile approach were used to identify PASS and MCII cutpoints in the EuroQol-5 Dimensions (EQ-5D) and the Short-Form-6 Dimensions (SF-6D) indexes, but also in other patient-reported outcomes (joint pain and patient global visual analog scale and Modified Health Assessment Questionnaire).

RESULTS

The PASS cutpoints estimated with 80% specificity were around 0.70 in EQ-5D in all diseases and around 0.65 in SF-6D. The cutpoints were around 0.65 and 0.60, respectively, when the 75th percentile approach was used. The MCII cutpoints assessed by 80% specificity varied from 0.10 to 0.19 in EQ-5D and from 0.07 to 0.10 in SF-6D.

CONCLUSION

The cutpoints for PASS in EQ-5D and SF-6D indicate that PASS corresponds to a health-related quality of life that is far from perfect health. Somewhat different cutpoints were identified for both PASS and MCII with 80% specificity versus the 75th percentile method.

Brominated flame retardants in aquatic organisms from the North Sea in comparison with biota from the high Arctic marine environment

The extent of trophic transfer of brominated flame retardants (BFRs), including hexabromocyclododecane (HBCD) and seven polybrominated diphenyl ethers (PBDEs), were examined in pelagic and benthic aquatic animals (invertebrates and fish) in a near-shore estuary environment of the southeastern North Sea (Norway; 59 degrees N). Whole-body burdens of HBCD and several of the most abundant PBDEs biomagnified with increasing trophic position in the food web. Biomagnification of HBCD was particularly strong, resulting in whole-body burdens of this compound comparable to those of total PBDEs in the higher-trophic-level species. Body burdens of PBDEs were higher in pelagic than in benthic aquatic organisms. This was particularly evident for the lesser-brominated and volatile PBDE congeners. Atmospheric gas-water-phytoplankton exchange of these volatile compounds over the water surface may account for this observation. The PBDE burdens in pelagic zooplankton from the North Sea were more than 60-fold greater than those in corresponding pelagic zooplankton from the colder high Arctic latitudes (>78 degrees N) of Norway (Svalbard). This great difference may relate to reduced chemical gas-water exchange over open waters at the colder Arctic latitudes. However, previously measured whole-body burdens of BFRs in other aquatic marine organisms from the high Arctic were comparable or even exceeded those in the North Sea samples of the present study. These include sympagic (sea ice-associated) invertebrates and fish accumulating high burdens of particle-associated BFRs. The present study provides new insight regarding the distribution of BFRs in ecologically different compartments of marine ecosystems, essential information for understanding the food-web transfer and geographical dispersal of these compounds.

Balsa raft crossing the Pacific finds low contaminant levels

During the Norwegian Tangaroa balsa raft expedition crossing the Pacific in 2006, surface water samples were collected by passive semipermeable membrane device (SPMD) sampling, active surface microlayer collection, and fish bile collection. The samples were analyzed for water contamination including a range of persistent organochlorine contaminants, pesticides, polycyclic aromatic hydrocarbons, as well as modern widespread chemicals such as brominated flame retardants, UV-filters, and perfluorinated compounds, using a network of expert laboratories and advanced instrumentation. Only trace to undetectable levels of all compounds were observed in both SPMDs and microlayer samples. The data from SPMDs were used to estimate surface water concentrations by back-calculation using sampling rates published in the literature. Conservative factors indicate that the levels in the surface waters are in the pg/L to subpg/L range for organochlorines, BFRs, and PFCs, indicating the central Pacific Ocean still represents a pristine environment for oceanic life.

Levels and temporal trends (1983-2003) of polybrominated diphenyl ethers and hexabromocyclododecanes in seabird eggs from north Norway

The present study assessed temporal trends (1983-2003) of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in eggs of herring gulls (Larus argentatus), Atlantic puffins (Fratercula arctica), and black-legged kittiwakes (Rissa tridactyla) in North Norway. Generally, PBDE concentrations increased between 1983 and 1993 and then leveled out, although species-specific trends were reported. Levels of alpha-HBCD increased in all species throughout the 20-year period. Levels of nona-BDEs and BDE 209 ranged from nondetectable to parts per billion. Nevertheless, highly variable procedural blanks were reported for the nona-BDEs and BDE 209, which clearly illustrates the importance of including blanks repeatedly during determination of these compounds.

ASDAS, a highly discriminatory ASAS-endorsed disease activity score in patients with ankylosing spondylitis

OBJECTIVES

To evaluate various validity aspects of four disease activity scores (ASDAS) for ankylosing spondylitis (AS) in comparison with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), its individual components and physician and patient global assessment of disease activity.

METHODS

The analyses were performed in two cohorts of patients with AS: (1) the NOR-DMARD database which includes patients starting on a disease-modifying antirheumatic drug or tumour necrosis factor (TNF) blocker and (2) patients participating in double-blind placebo controlled randomised clinical trials with TNF blockers in four centres. Discrimination between patients with low versus high disease activity according to various definitions and between various levels of change were analysed as the standardised mean difference (difference in the group means divided by the pooled SD of the group means) and t score.

RESULTS

The four ASDAS versions were highly discriminatory in differentiating patients with different levels of disease activity and patients with different levels of change. The ASDAS scores outperformed the BASDAI and its single components in all settings: patient- or physician-based, reflecting status or change, with normal or raised C-reactive protein (CRP), in the presence or absence of peripheral arthritis. There were no major differences between the four ASDAS scores. Based on feasibility, the ASAS membership selected the ASDAS version which included back pain, duration of morning stiffness, patient global assessment, peripheral joint complaints and CRP as the preferred version.

CONCLUSIONS

The ASDAS is a validated, highly discriminatory instrument for assessing disease activity in AS, including patient-reported outcomes and CRP levels.

Levels and temporal trends (1983-2003) of persistent organic pollutants (POPs) and mercury (Hg) in seabird eggs from Northern Norway

The main objective of this study was to investigate possible temporal trends of persistent organic pollutants (POPs) and mercury in eggs of herring gulls (Larus argentatus), black-legged kittiwakes (Rissa tridactyla), common guillemots (Uria aalge) and Atlantic puffins (Fratercula arctica) in Northern Norway. Eggs were collected in 1983, 1993 and 2003. Egg concentrations of POPs (PCB congeners IUPAC numbers: CB-28, 74, 66, 101, 99, 110, 149, 118, 153, 105, 141, 138, 187, 128, 156, 157, 180, 170, 194, 206, HCB, alpha-HCH, beta-HCH, gamma-HCH, oxychlordane, trans-chlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT) and mercury were quantified. Generally, POP levels decreased between 1983 and 2003 in all species. No significant temporal trend in mercury levels was found between 1983 and 2003.

A pilot randomized controlled trial of coblation tonsillectomy versus dissection tonsillectomy with bipolar diathermy haemostasis

OBJECTIVES

To compare postoperative recovery in children between 4 and 12 years undergoing tonsillectomy, using either coblation tonsillectomy or dissection tonsillectomy with bipolar diathermy haemostasis.

DESIGN

A prospective, single blind, randomised controlled trial.

SETTING

ENT clinic, University Teaching Hospital.

PARTICIPANTS

Forty paediatric patients, aged between 4 and 12 years and between 16 and 60 kg in weight with standard indication for tonsillectomy.

METHODS

Patients were randomly allocated to either coblation tonsillectomy or dissection tonsillectomy groups. Patients, parents, and nurses were blinded for operation method. Parents were asked to fill out a postoperative diary from 1 to 10 days.

MAIN OUTCOME MEASURES

Primary outcomes were scored for postoperative pain, nutrition, activity, and use of analgetics for each of the 10 postoperative days. Secondary outcomes were estimated from the nurses' postoperative data and 10-day follow-up statistics regarding crossing of the two-score limit.

RESULTS

The groups were statistically comparable by age, weight and operation type. There was no significant difference in operation time in two groups. Intra-operative bleeding was significantly less in the coblation group. Statistically significant differences between dissection tonsillectomy and coblation tonsillectomy were found in the day when a score of two of five was passed in pain scores (9.6 versus 6.2), nutrition scores (8.9 versus 6.6), activity score (8.4 versus 6.6) and medicine intake (9.4 versus 6.4), We found parallelism, between regression lines, that indicates better postoperative life quality for the coblation tonsillectomy group and approximately 2 days' shorter recovery time.

CONCLUSION

In our pilot study, patients undergoing coblation tonsillectomy reported less pain, quicker return to normal diet, quicker return to normal activity, and less use of analgetics over a 10-day period than patients undergoing dissection tonsillectomy. Our results indicate that the recovery period for coblation tonsillectomy was approximately 2 days shorter and demonstrated less morbidity.