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| 2. |
- Backmark, Anna, 1979, et al.
(författare)
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Affinity tags can reduce merohedral twinning of membrane protein crystals
- 2008
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Ingår i: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047 .- 0907-4449. ; D64, s. 1183-1186
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Tidskriftsartikel (refereegranskat)abstract
- This work presents a comparison of the crystal packing of three eukaryotic membrane proteins: human aquaporin 1, human aquaporin 5 and a spinach plasma membrane aquaporin. All were purified from expression constructs both with and without affinity tags. With the exception of tagged aquaporin 1, all constructs yielded crystals. Two significant effects of the affinity tags were observed: crystals containing a tag typically diffracted to lower resolution than those from constructs encoding the protein sequence alone and constructs without a tag frequently produced crystals that suffered from merohedral twinning. Twinning is a challenging crystallographic problem that can seriously hinder solution of the structure. Thus, for integral membrane proteins, the addition of an affinity tag may help to disrupt the approximate symmetry of the protein and thereby reduce or avoid merohedral twinning.
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| 3. |
- Arnell, Robert, et al.
(författare)
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Biotechnological Approach to the Synthesis of 9α-Hydroxylated Steroids
- 2007
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Ingår i: Preparative Biochemistry & Biotechnology. - : Informa UK Limited. - 1082-6068 .- 1532-2297. ; 37:4, s. 309-321
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Tidskriftsartikel (refereegranskat)abstract
- The steroid 9α-hydroxylase gene has been cloned from Mycobacterium smegmatis into Escherichia coli BL21. Progesterone added to bioreactors was subjected to in vivo transformation into 9α-hydroxyprogesterone. In 7 days, 43.6 mg9α-hydroxyprogesterone was formed from 53.8 mg/L progesterone. The enzyme also has shown evidence of processing 4-androstene-3,17-dione in vivo. An extensive analytical method development, including LLE, HPLC-DAD, MS, andNMR was performed to verify the product and to enable a quantitative analysis. Protocols for analytical and preparative separation have been developed, using binaphtol as internal standard. Both the growth pattern and the bioconversion ratewere unaffected by the presence of binaphtol in the bioreactor. The enzyme was purified by immobilised metal affinity and ion exchange chromatography, resulting in low in vitro activity.
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| 5. |
- Ersson, Karin, et al.
(författare)
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A longitudinal study of exercise-induced bronchoconstriction and laryngeal obstruction in high school athletes
- 2023
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 33:8, s. 1509-1518
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) are common in elite athletes. Knowledge of which factors are related to incident EIB and EILO is limited. The aim of this study was to explore the course of EIB and EILO in adolescent athletes over a 2 years period and baseline characteristics related to incident EIB.METHODS: Questionnaire data on respiratory symptoms, asthma, and aeroallergy and results of objective EIB and EILO tests were collected from 58 participants (27 tested for EILO) at baseline and after 2 years (follow-up). Associations between incident EIB and baseline asthma-like symptoms, exercise-induced symptoms, fractional exhaled nitric oxide (FeNO), aeroallergy, and sex were assessed using logistic regression models.RESULTS: Ten participants had incident EIB, and eight participants had persistent EIB. Five were EIB positive at baseline but negative at follow-up, while 35 participants were EIB negative at both time points. Having incident EIB was associated with reporting waking up with chest tightness (OR = 4.38; 95% CI: 1.06, 22.09). Reporting an increased number of asthma-like symptoms increased the likelihood of incident EIB (OR = 2.78; 95% CI: 1.16, 6.58). No associations were found between exercise-induced symptoms, FeNO, aeroallergy, or sex and incident EIB. Incident EILO was found in three and persistent EILO in two of the 27 participants tested.CONCLUSION: Two in nine had incident EIB and one eighth had incident EILO, suggesting that recurrent testing for EIB and EILO may be relevant in young athletes. Particularly, EIB-negative athletes reporting multiple asthma-like symptoms could benefit from recurrent EIB testing.
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| 6. |
- Ersson, Karin, et al.
(författare)
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Exercise-induced airway symptoms in young athletes; a follow-up from first to third year in sports high school
- 2020
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Ingår i: European Respiratory Journal. - : European Respiratory Society. ; 56:suppl 64
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Tidskriftsartikel (refereegranskat)abstract
- Adult elite athletes have a higher prevalence of exercise-induced airway symptoms than the general population and it is more common among female athletes than male. Studies on the prevalence of these symptoms in early-career athletes are scarce.We studied the prevalence of exercise-induced wheeze and dyspnoea in high school athletes, over a two year period, by inviting a cohort (n=272) to answer a questionnaire at age 16 and again at age 18.At age 16 the prevalence of wheeze was 20.5% and dyspnoea 30.1%, and at age 18 the corresponding figures were; wheeze 18.2% and dyspnoea 21.8%. In comparison with 18-year-olds from the general population (1), the high school athletes reported more wheeze (18.2% vs 12.4% p=0.02).At age 16, more female athletes reported wheeze and dyspnea compared with males (29.5 vs 12.4% p=0.001 and 43.2 vs 16.8% p<0.001). Two years later, no gender difference was found regarding wheeze, but more females reported dyspnoea, compared with males (28.3 vs 16.5% p=0.02). The prevalence of dyspnoea among females did however decrease with age (43.2 vs 28.3% p=0.005). This was mainly due to less reported dyspnoea, over the two year period, in females with current asthma (86.4 vs 54.5% p=0.008). In male athletes, the prevalence of both symptoms was similar over time.High school athletes have a higher prevalence of exercise-induced wheeze compared with the general population. A larger proportion of female athletes report exercise-induced symptoms compared with their male peers but this difference seems to decrease with age.1. Johansson H, et al. Respir Med. 2019;154:76-81.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 1391.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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| 7. |
- Ersson, Karin, et al.
(författare)
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Exercise-induced bronchoconstriction (EIB) is not associated with exhaled nitric oxide (FeNO) in adolescent athletes
- 2019
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Ingår i: European Respiratory Journal. ; 54:suppl 63
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Tidskriftsartikel (refereegranskat)abstract
- Background: The mechanisms of EIB have been suggested to differ between adult athletes and the general population. In line with this, FeNO has been associated with EIB in the general population, but not in adult athletes. Respiratory resistance measured by forced oscillation technique is suggested to be a more sensitive measurement of airway obstruction than FEV1.Aim: To study the association between baseline FeNO and post-exercise changes in FEV1 and respiratory resistance in adolescents either attending a sports high school or from the general population.Methods: Study group A consisted of 148 adolescents, aged 13-15 years, from the general population. Study group B consisted of 98 adolescents, aged 15-17 years, attending sports high school. The subjects performed FeNO before and FEV1 and respiratory resistance measurements at 5 Hz (R5) before and after a standardised exercise test.Results: A positive EIB test (fall in FEV1 ≥10%) was found in 48 subjects in group A and in 24 subjects in group B. FeNO related to post-exercise fall in FEV1 as well as increase in R5 in group A (rho=-0.17, p=0.04 and rho=0.34, p<0.001, respectively). No such relation was found in group B (p>0.05). Elevated FeNO (>25 ppb) was associated with EIB in group A: odds ratio (OR) 2.6 (CI 95% 1.1, 6.2), but not in group B (OR 1.0, CI 95% 0.3, 3.2). The findings in group A were consistent after adjusting for age, gender and height (aOR 2.6 CI 95% 1.1, 6.6).Conclusion: EIB in adolescent athletes is not associated with FeNO in contrast to adolescents from the general population. This indicates that the mechanisms leading to EIB in adolescent athletes may differ from the general population.FootnotesCite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA4508.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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| 8. |
- Ersson, Karin, et al.
(författare)
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Prevalence of exercise-induced bronchoconstriction and laryngeal obstruction in adolescent athletes
- 2020
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Ingår i: Pediatric Pulmonology. - : Wiley. - 8755-6863 .- 1099-0496. ; 55:12, s. 3509-3516
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To study the prevalence of exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) in adolescent athletes.METHODS: All adolescents (n = 549) attending first year at a sports high school in 2016 and 2017, were invited to answer a questionnaire on respiratory symptoms. The 367 responding participants were divided into two groups based on whether they reported exercise-induced dyspnea (dyspnea group) or not (non-dyspnea group). Randomly selected participants in each group were invited to undergo two standardized exercise tests, an EIB test and a continuous laryngoscopy exercise (CLE) test, to investigate EILO.RESULTS: In total, 98 participants completed an EIB test, 75 of whom also completed a CLE test. Positive EIB tests: eight of 41 in the dyspnea group and 16 of 57 in the non-dyspnea group. Positive CLE tests: five of 34 in the dyspnea group and three of 41 in the non-dyspnea group. The estimated prevalence of EIB was 23.1 % (95 % CI 14.5 - 33.8) and of EILO 8.1 % (95 % CI 2.5 - 18.5) in the whole study population. No differences in prevalence of EIB or EILO were found between the dyspnea and the non-dyspnea groups.CONCLUSION: EIB was highly prevalent in this cohort of adolescent athletes. EILO was less prevalent, but represents an important differential diagnosis to EIB. Self-reported exercise-induced dyspnea is a weak indicator for both EIB and EILO and standardized testing should be provided.
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| 9. |
- Jõgi, Nils Oskar, et al.
(författare)
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Device comparison study to measure nasal nitric oxide in relation to primary ciliary dyskinesia
- 2024
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Ingår i: Journal of Breath Research. - : Institute of Physics Publishing (IOPP). - 1752-7155 .- 1752-7163. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Primary ciliary dyskinesia (PCD) is a genetic respiratory disease characterized by chronic cough, recurrent respiratory infections, and rhinosinusitis. The measurement of nasal nitric oxide (nNO) against resistance has been suggested as a sensitive screening method. However, current recommendations argue for the use of expensive, chemiluminescence devices to measure nNO. This study aimed to compare nNO measurement using three different devices in distinguishing PCD patients from healthy controls and cystic fibrosis (CF) patients and to evaluate their diagnostic precision. The study included 16 controls, 16 PCD patients, and 12 CF patients matched for age and sex. nNO measurements were performed using a chemiluminescence device (Eco Medics CLD 88sp), and two devices based on electrochemical sensors (Medisoft FeNO+ and NIOX Vero) following standardized guidelines. Correlation estimation, Bland-Altman, ROC curve, and one-way ANOVA were used to assess device differences and diagnostic performance. Significantly lower nNO output values were observed in PCD and CF patients compared to controls during exhalation against resistance. The correlation analysis showed high agreement among the three devices. ROC curve analysis demonstrated 100% sensitivity and specificity at different cut-off values for all devices in distinguishing PCD patients from controls (optimal cut-offs: EcoMedics 73, Medisoft 92 and NIOX 87 (nl min-1)). Higher nNO output values were obtained with the Medisoft and NIOX devices as compared to the EcoMedics device, with a bias of-19 nl min-1(95% CI: -73-35) and -21 nl min-1(-73-31) accordingly. These findings indicate that all three tested devices can potentially serve as diagnostic tools for PCD if device specific cut-off values are used. This last-mentioned aspect warrants further studies and consideration in defining optimal cut-offs for individual device.
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