| 1. |
- Isaksson, Anders, et al.
(författare)
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High-Throughput LC-MS/MS Method for Determination of the Alcohol Use Biomarker Phosphatidylethanol in Clinical Samples by Use of a Simple Automated Extraction Procedure-Preanalytical and Analytical Conditions
- 2018
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Ingår i: The Journal of Applied Laboratory Medicine. - : Oxford University Press (OUP). - 2576-9456 .- 2475-7241. ; 2:6, s. 880-892
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phosphatidylethanol (PEth) is an alcohol use biomarker with higher clinical sensitivity and specificity than commonly used alcohol markers. Since its introduction as a clinical alcohol-marker in 2006, the number of samples sent to our laboratory for the determination of PEth has shown a strong annual increase. This has prompted the need to develop a cost-effective and reliable analytical procedure with high capacity. METHODS: An LC-MS/MS method for the determination of PEth 16:0/18:1 with a short turnaround time (3 min) has been evaluated with respect to accuracy, sensitivity, and precision. We compared this method with a previously used HPLC method, as well as a manual and a simplified automated method for sample workup, and investigated potential causes of analytic and preanalytic errors. RESULTS: The method shows limits of detection and quantification of 0.0075 μmol/L (5.2 ng/mL) and <0.05 μmol/L (<35 ng/mL), respectively. During a 2.1-year period, the method has shown a total CV < 8% for control samples (n = 2808) in the range of 0.10 (70) to 3.5 μmol/L (2461 ng/mL). The simplified automated method for sample preparation works equally well as the manual one. No specific and clinically significant causes of preanalytic errors were found. CONCLUSIONS: This LC-MS/MS method with automated sample workup is well suited for a clinical laboratory with LC-MS/MS experience and has the capability, proven from several years of use, to produce reliable PEth results in a high-volume laboratory (>50000 clinical samples/year).
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| 2. |
- Isaksson, Marléne, et al.
(författare)
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Exclusion of Disperse Orange 3 is possible from the textile dye mix present in the Swedish baseline patch test series. A study by the Swedish Contact Dermatitis Research Group
- 2022
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 88:1, s. 54-59
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Tidskriftsartikel (refereegranskat)abstract
- Background The textile dye mix (TDM) 6.6% in petrolatum contains Disperse Blue (DB) 35, Disperse Yellow 3, Disperse Orange (DO) 1 and 3, Disperse Red 1 and 17, and DB 106 and 124. The most frequent allergen in TDM-positive patients is DO 3. Around 85% of para-phenylenediamine (PPD)-allergic dermatitis patients have been positive to DO 3. There has been a discussion to exclude DO 3 from TDM 6.6% because of strong simultaneous reactions to TDM and PPD. Objectives To study if DO 3 can be excluded from TDM 6.6%. Methods Patch tests were performed on 1481 dermatitis patients with TDM 6.6%, TDM 7.0% (without DO 3 but the other disperse dyes at 1.0% each), DO 3 1.0%, and PPD 1.0% pet. Results Contact allergy to TDM 6.6% was 3.6% and to TDM 7.0% was 3.0%. All 26 DO 3-positive patients were positive to PPD. The 44 patients positive to TDM 7.0% plus the 13 positive to PPD and TDM 6.6% but negative to TDM 7.0% were 57, outnumbering the 53 positive to TDM 6.6%. Conclusion TDM 7.0% can replace TDM 6.6% in the Swedish baseline series, since TDM 7.0% together with PPD 1.0% will detect patients with textile dye allergy.
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| 3. |
- Linauskiene, Kotryna, et al.
(författare)
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Patch test results to extracts of synthetic garments in textile dye positive patients
- 2022
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 87:4, s. 325-330
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Tidskriftsartikel (refereegranskat)abstract
- Background: Disperse dyes (DDs) are the most prevalent causes of textile-related allergic contact dermatitis and are used for colouring synthetic textile materials based on fibres such as polyester, acrylic, acetate and polyamide. Eight DDs are included in a textile dye mix (TDM) 6.6% petrolatum (pet.) in the European baseline patch test series. Objectives: The aim of this study was to patch test TDM 6.6% pet. positive individuals with the extracts of synthetic fibre clothes that do not contain any of the pure DDs present in the TDM 6.6% to study the reactivity pattern. Methods: Seventy-three TDM-positive former patients tested between 2012 and 2017 at the Department of Occupational and Environmental Dermatology in Malmö, Sweden were invited to join the study, 10 participated. Twenty-four textile items (collected in nine countries in Europe, Asia and North America in 2012) were extracted in dichloromethane. The TDM 6.6% was patch tested simultaneously with the 24 textile item preparations in petrolatum made from the extracts. Prior to patch testing the participants filled the 7-question questionnaire regarding possible symptoms from textile exposure. Results: Ten individuals, agreed to join the study. Eight of them reacted to TDM 6.6%. Nine participants reacted to 20 of 24 extracts. One reacted to 19 extracts, another to 14, 3 to 5 extracts, 1 to 4, 1 to 3 extracts and 2 to 2 extracts. One was negative to all tested preparations including TDM 6.6%. The participants mainly reacted to six textile extracts. All controls tested negatively to tested extracts. Four individuals of the 10 TDM-allergic individuals previously had had problems after wearing clothes. Four out of the 10 participants had had atopic eczema in childhood. All women had dyed their hair with permanent hair dyes but none of the males. Conclusion: TDM-positive patients react to textile extracts made from synthetic garments, even if they do not contain any of the pure DDs present in TDM 6.6%. More studies are needed to pin-point the culprit haptens in these extracts.
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| 4. |
- Stenton, Joanna, et al.
(författare)
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Inter Individual Variation and Factors Regulating the Formation of Phosphatidylethanol
- 2019
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Ingår i: Alcoholism: Clinical and Experimental Research. - : Wiley. - 0145-6008 .- 1530-0277. ; 43:11, s. 2322-2331
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Tidskriftsartikel (refereegranskat)abstract
- Background: Alcohol use disorders are a major but often unrecognized health problem. Alcohol markers can therefore be of great value for diagnosis, follow-up, and treatment evaluation. Phosphatidylethanol in blood (B-PEth) is an alcohol biomarker with higher clinical sensitivity and specificity than commonly used alcohol markers but has shown a considerable interindividual variation in relation to reported consumption. Methods: An in vitro system was used to investigate factors, which may affect the formation rate of PEth or which may give rise to interindividual variation in the rate of formation. In this system, isolated erythrocytes from 31 individuals were incubated in the presence of various concentrations of ethanol (EtOH). The concentration of PEth and phosphatidylcholine (PC), the parent molecule of PEth, was determined by chromatographic methods. Results: Time, EtOH, and PC concentration were major factors determining the amount of PEth formed. The interindividual variation in PEth formation rate, calculated at an EtOH concentration of 50 mmol/l, showed a coefficient of variation (CV) from 23 to 31% for the different PEth forms studied (PEth 16:0/18:2, total PEth and PEth 16:0/18:1). The concentration of PC was found to be an important determinant of this variation. The formation rate for PEth 16:0/18:2 was somewhat higher than for PEth 16:0/18:1. The formation of PEth 16:0/18:1 but not PEth 16:0/18:2 showed a positive correlation to the concentration of PEth at baseline (endogenous PEth). Calculation of enzyme kinetics for the reaction resulting in the formation of PEth 16:0/18:1 or PEth 16:0/18:2 showed an apparent Km (Michaelis constant) of approximately 160 to 170 mmol/l. Conclusions: Interindividual variation in the formation rate of PEth appears to be a significant but relatively modest source of variation in the relation between B-PEth and reported consumption. Correction for interindividual variation in PC concentrations might substantially reduce the interindividual variability in PEth formation and consequently in B-PEth.
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| 5. |
- Stenton, Joanna, et al.
(författare)
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Patch testing with a textile dye mix with and without Disperse Orange 3
- 2020
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 83:5, s. 387-390
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Tidskriftsartikel (refereegranskat)abstract
- Background: The textile dye mix (TDM) 6.6% pet. contains Disperse Blue (DB) 35, Disperse Yellow 3, Disperse Orange (DO) 1 and 3, Disperse Red 1 and 17, and DB 106 and 124. The most frequent allergen in TDM-positive patients is DO 3. Around 85% of p-phenylenediamine (PPD)-allergic dermatitis patients have shown positive patch test reactions to DO 3. There has been a discussion to exclude DO 3 from TDM 6.6% because of frequent, strong reactions to TDM 6.6% and PPD. Objectives: To study if DO 3 can be omitted from a TDM. Methods: Patch tests were performed on 2250 dermatitis patients with TDM 6.6%, TDM 5.6% pet., TDM 7.0% pet., and PPD 1.0% pet.; 122 patients were also patch tested with DO 3 1.0% pet. Results: Among the 2250 patients patch tested, contact allergy prevalence to TDM 6.6% was 2.4%, to TDM 5.6% 1.8%, and to TDM 7.0% 2.0%. Of the 54 TDM 6.6%-positive patients, 55.6% reacted to PPD; as much as 42.2% of PPD-allergic women and 50% of PPD-allergic men reacted to TDM 6.6%. Of the 17 DO 3-positive patients, 94.1% showed a positive reaction to PPD. Conclusion: Results indicate that DO 3 can probably be omitted from TDM, but patch testing with TDM 6.6%, TDM 7.0%, DO 3 1.0%, and PPD 1.0% simultaneously is needed to finally decide whether it is possible or not.
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