Immunological biomarkers in patients with radiographic axial spondyloarthritis, an exploratory longitudinal Swedish study.

Objectives There is a need for more specific biomarkers to diagnose and predict disease course in patients with axial spondyloarthritis (axSpA). This study aimed to study immunological plasma biomarkers, at different time-points in radiographic (r)-axSpA patients overall and stratified by sex and compare these biomarker pattern in r-axSpA patients concerning disease phenotypes and disease activity. Methods Plasma samples were analysed from r-axSpA patients at and prior (Pre-Backbone) inclusion in the Backbone study. Interferon gamma, interleukin-10, -17A, -17F, -22, -23, -6, MCP-1, TNF-α, VEGF-A, MIF, IgA anti-CD74, zonulin, ESR, hsCRP, white blood cell count, and blood lipids were measured. Results Biomarker pattern discriminated significantly between r-axSpA patients in Backbone and Pre-Backbone compared with controls. When stratifying by sex, it was possible to discriminate between male and female r-axSpA patients in Backbone vs controls and between male r-axSpA patients in pre-Backbone and controls. In Backbone, markers with high discriminative capacity were MIF, IgA anti-CD74, and MCP-1. In Pre-Backbone, IL-6, TNF-α, MIF, triglycerides, cholesterol, IL-10, and zonulin displayed high discriminative capacity. Conclusion Based on their temporal pattern and mutual relationship, we suggest studying MIF, IgA anti-CD74, and MCP-1 in depth, at more time points, to further elucidate disease-driving mechanisms in this complex disease.

Increased proportions of inflammatory T cells and their correlations with cytokines and clinical parameters in patients with ankylosing spondylitis from northern Sweden.

Ankylosing spondylitis (AS) is an autoimmune disease affecting parts of the skeletal structure in particular. Previously increased levels of the inflammatory cell types Th17, Th22, Tc17 and Tc22 cells have been shown to be associated with AS. Here, we analysed the levels of inflammatory T cell subsets, related cytokines and clinical characteristics of AS patients vs controls from northern Sweden. Peripheral blood mononuclear cells (PBMCs) obtained from 50 AS patients and 50 matched controls were short term stimulated with PMA/Ionomycin, stained and analysed by flow cytometry. Plasma levels of Interleukin (IL)-17, IL-22, IL-10 as well as clinically relevant markers were determined. Compared to male controls, male AS patients showed 1.5- to 2-fold increases of Th17 (P = .013), Th22 (P = .003) and Tc22 (P = .024) among CD45+ CD3+ lymphocytes. Plasma IL-22 levels correlated with the Tc17 proportion in male patients (Rs  = 0.499, P = .003) and plasma IL-10 levels were inversely correlated with Tc17 among all patients (Rs  = -0.276, P = .05). Male patients with syndesmophytes showed significantly higher Th17 proportions (P = .038). In female AS patients, Tc22 was negatively correlated with C-reactive protein (high sensitivity) (hsCRP) (Rs  = -0.573, P = .016). We confirmed increased proportions of inflammatory T cells and correlations with relevant cytokines from male AS patients. The correlation between Th17 and syndesmophytes supports a role of Th17 in the pathogenic process.

Efficiency of a biodegradable gel containing hyaluronic acid and berberine hydrochloride in endoscopic sinus surgery (ESS): A prospective comparative study.

PURPOSE: To evaluate the efficiency of a biodegradable gel containing hyaluronic acid and berberine hydrochloride in endoscopic sinus surgery. METHODS: Sixty-six chronic rhinosinusitis patients with or without nasal polyps who underwent bilateral endoscopic sinus surgery (ESS) were randomly received a biodegradable gel containing hyaluronic acid and berberine hydrochloride or merocel in both middle meatal spacers at the end procedure of ESS. Lund-Kennedy endoscopic score (LKES) was used to examine status of nasal cavity on preoperative day and postoperative day 1 to 7. The LKES ratio was calculated as the LKES on postoperative day divided into the LKES on preoperative day. Visual analogue score (VAS) was used to assess patient's status from the first postoperative day to the hospital discharge day. The average VAS during hospital stays was calculated by the sum of VAS in each examination day divided into the number of examined day. The LKES ratio, the average of VAS during hospital stays and length of hospitalized day of the patients were used as clinical outcome indices in early stage after surgery. A general linear model adjusted for confounding factors was used for data analysis. RESULTS: Adjusted mean of LKES ratio were lower in group used biodegrable gel of hyaruloic acid and berberin hydrochlode (study group) than those in merocele group in the postoperative day 1 to day 7. However, significant difference was found in the adjusted mean of LKES ratio on the postoperative day 2 to 6. Similarly, the adjusted mean of VAS during hospital stays and length of hospitalized day after surgery in study group were significantly decreased as compared with those in merocele group. CONCLUSIONS: Biodegradable material containing hyaluronic acid and berberine hydrochloride was more effective than merocel in length of hospital stay, post-operative symptoms, and sinus cavity's status in early stage after ESS.

Anti-CD74 IgA autoantibodies in radiographic axial spondyloarthritis: a longitudinal Swedish study.

OBJECTIVES: Antibodies against anti-CD74 are related to axial spondyloarthritis (axSpA). The objectives were (i) to study IgA anti-CD74 in radiographic (r)-axSpA patients in the Backbone cohort and to calculate the sensitivity and specificity of anti-CD74, (ii) to study the fluctuation of IgA anti-CD74 levels in prospectively collected samples, and (iii) to explore the relation between IgA anti-CD74 and radiographic spinal changes. METHODS: IgA anti-CD74 was analysed by ELISA in 155 patients with r-axSpA and age- and sex-matched controls. BASDAI, ASDAS, BASFI and BASMI were assessed and spinal radiographs were scored for r-axSpA-related changes with mSASSS. Previously donated samples, before inclusion in the Backbone study, were identified in the Medical Biobank of Northern Sweden. RESULTS: A total of 155 patients comprising 69% men and 31% women, age [mean (s.d.)] 55.5 (11.4) years and 152 (98.1%) HLA-B27 positive, were included. The plasma level of IgA anti-CD74 was significantly higher in the patients [median (interquartile range), 12.9 (7.9-17.9) U/ml] compared with controls [10.9 (7.2-14.6) U/ml, P = 0.003]. IgA anti-CD74 was above the cut-off level of 20 U/ml in 36/155 (23.2%) patients and in 15/151 (9.9%) controls (P = 0.002). Multivariable logistic regression analyses revealed ≥1 syndesmophyte associated with IgA anti-CD74 (odds ratio 5.64; 95% CI: 1.02, 35.58; P = 0.048) adjusted for hsCRP, smoking, BMI, sex and age. No distinct pattern of IgA anti-CD74 over time was revealed. CONCLUSION: Plasma levels of IgA anti-CD74 were increased in r-axSpA and independently associated with radiographic spinal changes, which suggests that IgA anti-CD74 could play a role in the pathogenies of r-axSpA.

'Hu Hong' (bad thing): parental perceptions of teenagers' sexuality in urban Vietnam.

BACKGROUND: Teenagers under 18 years old in Vietnam are considered as minors who usually lack the autonomy to make decisions. They are also sometimes viewed as contributors to social evils including crime, violence and substance use. Moreover, most Vietnamese teenagers have unsafe sex before marriage. The objective of this study is to explore the parental perceptions relating to their teenagers' sexuality, particularly the social and cultural forces, that may hinder access to sexuality information. METHODS: Guided by a Community Advisory Board (CAB), this qualitative study uses four focus group discussions (FGDs) consisting of 12 mothers and 12 fathers, as well as twelve individual in-depth interviews (IDIs) with a diverse sample of parents of teens in Ho Chi Minh City (HCMC), Vietnam. Content and discourse analysis were conducted, based on Foucauldian concepts. RESULTS: Four themes emerged: 1) Meanings of sexuality and sexuality education, 2) Early sexual intercourse destroys teenagers' future, 3) Teenagers are not hu hong (spoil/bad thing), are innocent and virgin, and 4) Policing and controlling of sexual intercourse among teens. Parents did not view their teenage children as sexual beings; those who are sexual are considered hu hong. Parents believed that teens need to be policed and controlled to prevent them from becoming hu hong, particularly girls. Controlling of sexuality information by parents was therefore common in HCMC, but differed by gender and educational levels of parents. For example, fathers more than mothers were not comfortable teaching their teenage children about sex and sexuality. Parents with higher education police their teenage children's usage of the Internet and social media, while parents with lower education control who can be friends with their teenage children. CONCLUSIONS: Vietnamese parents in general have negative views of sex and sexuality education for their teenage children. Recognizing that many Vietnamese teenagers have unsafe sex before marriage, parents need to change their perceptions and understand the importance of comprehensive sexuality education (CSE), which are included in UNESCO, UNFPA and UNICEF-developed CSE tools.

Is low molecular weight hyaluronan an early indicator of disease in avian systemic sclerosis?

AIM OF THE STUDY: To further elucidate the pathogenesis of systemic sclerosis (SSc) an experimental avian model was used. The University of California at Davis line 200 (UCD-200) chickens spontaneously develop a SSc-like disease that has most features of human SSc with vascular effects, inflammation, autoimmunity, and fibrosis. The first signs of disease in UCD-200 chickens are swelling and ischemic lesions of the comb and the presence of a tissue containing high amounts of glycosaminoglycan hyaluronan (HA). The aim of this study was to evaluate inflammatory and fibrotic processes of the disease with regard to the molecular weight of HA. MATERIAL AND METHODS: Comb biopsies from UCD-200 and healthy White Leghorn (WL) chickens, as controls, at different ages were studied with the histochemical localization of HA, hyaluronidase-1 (Hyal-1), cluster of differentiation 3, immunoglobulin Y, and collagen I and III. The molecular weight distribution of HA was estimated with gas-phase electrophoretic analysis. RESULTS: At 2 days of age, HA was visualized in UCD-200 chickens at the dermal part of the comb with no simultaneous staining of Hyal-1. In adult UCD-200 chickens, the comb skin was almost totally devoid of HA compared to WL chickens of the same age. An increase of low molecular weight (LMW) HA was detected in comb tissue from UCD-200 at the age of 1 day, 1 week, 2 weeks, and 4 weeks, in contrast to adult animals. CONCLUSIONS: An early inflammatory process involving LMW HA was confirmed as a possible profibrotic process. This indicates that HA might be an important participant in the early inflammatory events of SSc in UCD-200 chickens and that the disappearance of HA in skin predisposes to fibrosis.

The seroprevalence of toxocariasis and related risk factors in children in Ho Chi Minh City, Vietnam: results from a school-based cross-sectional study.

BACKGROUND: Children are especially vulnerable to Toxocara infection and its severe complications; however, there have not been any published data on the disease prevalence and treatment effectiveness in the population of Vietnamese children. This study was conducted to determine the prevalence of toxocariasis and explore factors associated with Toxocara infection in children aged 3-15 y in Ho Chi Minh City, Vietnam. METHODS: We conducted a cross-sectional study using a multistage cluster sampling approach in public schools. Blood samples were collected, and toxocariasis cases were confirmed, based on a history of contact with dogs/cats and positive anti-Toxocara antibody detection via ELISA. We calculated the percentage of seropositive children across gender, grade levels, districts and caregiver education. Multiple regression models were employed to identify potential risk factors. RESULTS: Anti-Toxocara antibodies were found in 14.2% of the 986 children studied. Significant variations in seropositivity were observed across grade levels, districts and caregiver education levels. Multivariable analysis identified caregiver education, contact with dogs/cats and improper handling of pet feces as seropositivity risk factors. CONCLUSION: This was the first community-based prevalence study of toxocariasis in a pediatric population in Vietnam. Implementation of preventive measures such as public education, routine fecal examinations and chemotherapeutic treatment of animals is highly recommended.

The Underappreciated Benefits of Interleaving for Category Learning.

The present study examined the effects of study schedule (interleaving vs. blocking) and feature descriptions on category learning and metacognitive predictions of learning. Across three experiments, participants studied exemplars from different rock categories and later had to classify novel exemplars. Rule-based and information-based categorization was also manipulated by selecting rock sub-categories for which the optimal strategy was the one that aligned with the extraction of a simple rule, or the one that required integration of information that may be difficult to describe verbally. We observed consistent benefits of interleaving over blocking on rock classification, which generalized to both rule-based (Experiment 1) and information-integration learning (Experiments 1-3). However, providing feature descriptions enhanced classification accuracy only when the stated features were diagnostic of category membership, indicating that their benefits were limited to rule-based learning (Experiment 1) and did not generalize to information-integration learning (Experiments 1-3). Furthermore, our examination of participants' metacognitive predictions demonstrated that participants were not aware of the benefits of interleaving on category learning. Additionally, providing feature descriptions led to higher predictions of categorization even when no significant benefits on actual performance were exhibited.

Assessing Awareness of Colorectal Cancer Symptoms among Outpatients: A Cross-Sectional Study at a Hospital in Vietnam.

Colorectal cancer (CRC) is a prevalent cancer globally, including in Vietnam where its incidence is rapidly increasing. The aim of this study was to evaluate the awareness of signs, symptoms, and risk factors of colorectal cancer among outpatients at Hoa Hao Medic Company Limited, Ho Chi Minh City, Vietnam. A cross-sectional study was conducted, and a total of 441 people who visited Hoa Hao Medic Company Limited for a general health check-up and voluntarily agreed to participate in this study were recruited through the convenience sampling method. Data were collected through face-to-face structured interviews using the Bowel CAM questionnaire. According to the results, the highest percentage of well-recalled warning signs were "change in bowel habit" (36.7%) followed by abdominal pain (35.4%). Other warning signs such as weight loss and rectal bleeding were reported by 19.0% and 18.1% of participants, respectively. Over 42% of participants stated that they were unaware of any signs or symptoms. The most commonly identified risk factors for CRC were pollution (66.9%), genetics (50.6%), and an unhealthy/poor diet (53.7%) for unprompted questions. The overall awareness score of participants was 3.46/9 (SD ± 2.91) for signs and symptoms of CRC and 5.90/10 (SD ± 1.62) for risk factors. Univariate linear regression identified education level and occupation as predictors of higher CRC awareness. In conclusion, this study highlights that overall awareness of CRC is low among outpatients at Hoa Hao Medic Company Limited. Strategies to increase awareness, knowledge, and education programs are necessary to promote early detection of CRC and reduce its burden in Vietnam.

Biofilms: Formation, drug resistance and alternatives to conventional approaches.

Biofilms are aggregates of bacteria, in most cases, which are resistant usually to broad-spectrum antibiotics in their typical concentrations or even in higher doses. A trend of increasing multi-drug resistance in biofilms, which are responsible for emerging life-threatening nosocomial infections, is becoming a serious problem. Biofilms, however, are at various sensitivity levels to environmental factors and are versatile in infectivity depending on virulence factors. This review presents the fundamental information about biofilms: formation, antibiotic resistance, impacts on public health and alternatives to conventional approaches. Novel developments in micro-biosystems that help reveal the new treatment tools by sensing and characterization of biofilms will also be discussed. Understanding the formation, structure, physiology and properties of biofilms better helps eliminate them by the usage of appropriate antibiotics or their control by novel therapy approaches, such as anti-biofilm molecules, effective gene editing, drug-delivery systems and probiotics.

Social violence among Thai gender role conforming and non-conforming secondary school students: Types, prevalence and correlates.

BACKGROUND: Gender role non-conforming behaviors are a significant risk factor for school-related violence. The objective of this study is to describe the types, prevalence and correlates of social violence among Thai secondary school students, with a focus on gender role non-conformity. METHODS: This article uses secondary data from a national study of 2070 secondary school students aged 13-20 years representing Bangkok and all four regions of Thailand. Students were asked about their gender/sexual identity, self-perception of their masculinity or femininity, and experiences of social violence. Correlates of social violence were examined using multivariable logistic regression models. RESULTS: Prevalence of social violence victimization was high (57%). Most students considered themselves to be as masculine or as feminine as other members of their sex (82.6%), while 9.1% thought that they were less masculine/less feminine, and 8.3% thought they were more masculine/more feminine. Students who considered themselves less masculine or less feminine than others of their sex (AOR = 1.59, 95% CI: 1.13, 2.25) were more likely to experience social violence, compared to students who considered themselves equally masculine/feminine. Students who self-identified as lesbian, gay, bisexual or transgender (LGBT) (AOR = 1.37, 95% CI: 1.01, 1.86) were also more likely to experience social violence, compared to students who did not identify as LGBT. However, students who considered themselves more masculine or feminine than other students of their sex (AOR = 0.62, 95% CI: 0.44, 0.88) were less likely to experience social violence. DISCUSSION: Students who identified as LGBT, or considered themselves to be less masculine or less feminine than other students of their sex, had higher odds of social violence victimization. Anti-bullying campaigns need to emphasize that perpetrating social violence is not tolerated, and gender-based violence needs to be included in comprehensive sexuality education curricula.

Low Molecular Mass Myocardial Hyaluronan in Human Hypertrophic Cardiomyopathy.

During the development of hypertrophic cardiomyopathy, the heart returns to fetal energy metabolism where cells utilize more glucose instead of fatty acids as a source of energy. Metabolism of glucose can increase synthesis of the extracellular glycosaminoglycan hyaluronan, which has been shown to be involved in the development of cardiac hypertrophy and fibrosis. The aim of this study was to investigate hyaluronan metabolism in cardiac tissue from patients with hypertrophic cardiomyopathy in relation to cardiac growth. NMR and qRT-PCR analysis of human cardiac tissue from hypertrophic cardiomyopathy patients and healthy control hearts showed dysregulated glucose and hyaluronan metabolism in the patients. Gas phase electrophoresis revealed a higher amount of low molecular mass hyaluronan and larger cardiomyocytes in cardiac tissue from patients with hypertrophic cardiomyopathy. Histochemistry showed high concentrations of hyaluronan around individual cardiomyocytes in hearts from hypertrophic cardiomyopathy patients. Experimentally, we could also observe accumulation of low molecular mass hyaluronan in cardiac hypertrophy in a rat model. In conclusion, the development of hypertrophic cardiomyopathy with increased glucose metabolism affected both hyaluronan molecular mass and amount. The process of regulating cardiomyocyte size seems to involve fragmentation of hyaluronan.

High Sensitivity Method to Estimate Distribution of Hyaluronan Molecular Sizes in Small Biological Samples Using Gas-Phase Electrophoretic Mobility Molecular Analysis.

Hyaluronan is a negatively charged polydisperse polysaccharide where both its size and tissue concentration play an important role in many physiological and pathological processes. The various functions of hyaluronan depend on its molecular size. Up to now, it has been difficult to study the role of hyaluronan in diseases with pathological changes in the extracellular matrix where availability is low or tissue samples are small. Difficulty to obtain large enough biopsies from human diseased tissue or tissue from animal models has also restricted the study of hyaluronan. In this paper, we demonstrate that gas-phase electrophoretic molecular mobility analyzer (GEMMA) can be used to estimate the distribution of hyaluronan molecular sizes in biological samples with a limited amount of hyaluronan. The low detection level of the GEMMA method allows for estimation of hyaluronan molecular sizes from different parts of small organs. Hence, the GEMMA method opens opportunity to attain a profile over the distribution of hyaluronan molecular sizes and estimate changes caused by disease or experimental conditions that has not been possible to obtain before.

Microcystin uptake and biochemical responses in the freshwater clam Corbicula leana P. exposed to toxic and non-toxic Microcystis aeruginosa: Evidence of tolerance to cyanotoxins.

We investigated the accumulation and adverse effects of toxic and non-toxic Microcystis in the edible clam Corbicula leana. Treated clams were exposed to toxic Microcystis at 100 µg of MC (microcystin)-LReq L-1 for 10 days. The experimental organism was then placed in toxin-free water and fed on non-toxic Microcystis for the following 10 days for depuration. Filtering rates (FRs) by C. leana of toxic and non-toxic Microcystis and of the green alga Chlorella vulgaris as a control were estimated. Adverse effects were evaluated though the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST). Clam accumulated MCs (up to 12.7 ± 2.5 µg g-1 dry weight (DW) of free MC and 4.2 ± 0.6 µg g-1 DW of covalently bound MC). Our results suggest that although both toxic and non-toxic cyanobacteria caused adverse effects by inducing the detoxification and antioxidant defense system, the clam was quite resistant to cyanotoxins. The estimated MC concentration in C. leana was far beyond the World Health Organization's (WHO) provisional tolerable daily intake (0.04 µg kg-1 day-1), suggesting that consuming clams harvested during cyanobacterial blooms carries a high health risk.

Multivariate data analysis to characterize gas chromatography columns for dioxin analysis.

Principal component analysis (PCA) was applied for evaluating the selectivity of 22 GC columns for which complete retention data were available for the 136 tetra- to octa-chlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Because the hepta- and octa-homologues are easy to separate the PCA was focused on the 128 tetra- to hexa-CDD/Fs. The analysis showed that 21 of the 22 GC columns could be subdivided into four groups with different selectivity. Group I consists of columns with non-polar thermally stable phases (Restek 5Sil MS and Dioxin 2, SGE BPX-DXN, Supelco Equity-5, and Agilent DB-1, DB-5, DB-5ms, VF-5ms, VF-Xms and DB-XLB). Group II includes ionic liquid columns (Supelco SLB-IL61, SLB-IL111 and SLB-IL76) with very high polarity. Group III includes columns with high-percentage phenyl and cyanopropyl phases (Agilent DB-17 and DB-225, Quadrex CPS-1, Supelco SP-2331, and Agilent CP-Sil 88), and Group IV columns with shape selectivity (Dionex SB-Smectic and Restek LC-50, Supelco ßDEXcst, Agilent VF-Xms and DB-XLB). Thus, two columns appeared in both Group I and IV (Agilent VF-Xms and DB-XLB). The selectivity of the other column, Agilent DB-210, differs from those of these four groups. Partial least squares (PLS) regression was used to correlate the retention times of the tetra- to hexa-CDD/Fs on the 22 stationary phases with a set of physicochemical and structural descriptors to identify parameters that significantly influence the solute-stationary phase interactions. The most influential physicochemical parameters for the interaction were associated with molecular size (as reflects in the total energy, electron energy, core-core repulsion and standard entropy), solubility (aqueous solubility and n-octanol/water partition coefficient), charge distribution (molecular polarizability and dipolar moment), and reactivity (relative Gibbs free energy); and the most influential structural descriptors were related to these parameters, in particular, size and dipolar moment. Finally, the PCA and PLS analyses were complemented with linear regression analysis to identify the most orthogonal column combinations, which could be used in comprehensive two-dimensional gas chromatography (GC×GC) to enhance PCDD/F separation and congener profiling.

Optimization of selective pressurized liquid extraction for extraction and in-cell clean-up of PCDD/Fs in soils and sediments.

This paper describes the development of methods for selective extraction of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from soils and sediments, using pressurized liquid extraction with in-cell clean-up (SPLE). Two binary solvent mixtures, viz. dichloromethane/n-heptane (DCM/Hp), and diethylether/n-heptane (DEE/Hp), were evaluated. The SPLE extraction conditions were optimized using central composite face (CCF) design. Three factors were investigated: extraction temperature (60-160 °C), number of extraction cycles (1-3) and time per cycle (2-18 min). The results showed that DCM/Hp (1/1, v/v) and DEE/Hp (1/2, v/v) were the best extraction solvent compositions and that the extraction temperature was a critical factor that needed careful optimization to achieve high extraction efficiency without co-extraction of sulfuric acid. Under the optimal conditions, the SPLE methods provided results with good accuracy and precision. For the sandy soil certified reference material (CRM-529) the quantification results ended up in the range 82-110% as compared to the concentrations obtained by a reference method based on Soxhlet extraction and external column clean-up. Furthermore, for a clay soil (CRM-530) and a sediment reference material (WMS-01), the accuracy (trueness) of the TEQ values were +11% (DCM/Hp) and +8% (DEE/Hp) for CRM-530, +8% and -7% for WMS-01, respectively. The individual congener concentrations also agreed well with the certified values. These findings show that SPLE is a promising method for combined extraction and clean-up of PCDD/Fs in soil/sediment samples.

Comprehensive profiling of 136 tetra- to octa-polychlorinated dibenzo-p-dioxins and dibenzofurans using ionic liquid columns and column combinations.

The orders of elution of all 136 tetra- to octa-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined on six gas chromatography (GC) columns. Three of these columns had ionic liquid stationary phases (SLB-IL111, SLB-IL76 and SLB-IL61; Supelco), one a liquid crystal phase (LC-50; Restek), one a chiral phase (ßDEXcst; Restek) and one a low bleed non-polar phase (DB-XLB; J&W/Agilent). According to our results, the high polarity and multiple solvation interactions of the ionic liquid stationary phases offered superior resolving power to that achieved with previously evaluated columns. The SLB-IL61 and SLB-IL111 columns resolved or partially separated 106 and 100 congeners, respectively, of the 136 PCDD/Fs. The SLB-IL61 also resolved 15 and partially separated one of the seventeen 2,3,7,8-substituted PCDD/Fs. Additional congeners can be separated by complementary analyses using additional columns in a dual- or triple-column approach. For example, using a combination of the SLB-IL61 and SLB-IL111 columns all but 8 congeners would be separated, including all 2,3,7,8-substituted PCDD/Fs. Two more congeners would be separated using a combination of SLB-IL76 and a liquid crystal (SB-Smectic) column, but in this case the 2,3,7,8-TeCDF would not be resolved. Three-column combinations would give even better separation: the DB-17/Smectic/SLB-IL76 and DB-225/Smectic/SLB-IL111 combinations would separate all but 1 of the 136 PCDD/F congeners. Unfortunately, the smectic column is no longer in production. If only commercially available columns are considered, combinations of SLB-IL61 and SLB-IL111 with DB-XLB, LC-50, or DB-225 offer the best performance, with 4, 4, and 3 unresolved congeners, respectively. Moreover, in each of these cases, one of the congeners in each unresolved pair is resolved on at least one of the other columns and so a reasonable estimate of the unresolved congeners' concentrations can be obtained by subtraction. The profiling of all 136 PCDD/Fs is thus greatly facilitated by using ionic liquid columns or combinations including such columns. However, there is room for improvement in the technical performance of the evaluated ionic liquid columns: their long-term retention time stability was poor and some highly chlorinated and sterically hindered congeners underwent dehalogenation during separation.