| 1. |
- Gossas, Thomas, et al.
(författare)
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The advantage of biosensor analysis over enzyme inhibition studies for slow dissociating inhibitors : characterization of hydroxamate-based matrix metalloproteinase-12 inhibitors
- 2013
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Ingår i: MedChemComm. - : Royal Society of Chemistry (RSC). - 2040-2503 .- 2040-2511. ; 4:2, s. 432-442
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Tidskriftsartikel (refereegranskat)abstract
- The kinetic characteristics of hydroxamate-based inhibitors of matrix metalloproteinase (MMP)-12 were explored using an SPR biosensor-based assay and enzyme inhibition analysis. These high-affinity inhibitors were shown to dissociate very slowly from the enzyme-inhibitor complex while a carboxylate analogue had a much faster dissociation rate, verifying the importance of the hydroxamate group for the slow dissociation. Progress curve enzyme inhibition analysis confirmed that the hydroxamate compounds but not the carboxylate compound acted as time-dependent inhibitors. The slow dissociation excluded steady-state estimation of IC50-values and K-i values but also made K-i values from progress curve analysis unreliable. Although a full characterization of the inhibitors using biosensor analysis was limited by slow dissociation, it provided kinetic and mechanistic information of relevance for MMP drug discovery and avoided some pitfalls of conventional enzyme inhibition assays.
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| 2. |
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| 3. |
- Nordström, Helena, et al.
(författare)
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Identification of MMP-12 Inhibitors by Using Biosensor-Based Screening of a Fragment Library
- 2008
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 51:12, s. 3449-3459
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Tidskriftsartikel (refereegranskat)abstract
- Small inhibitors of matrix metalloproteinase 12 (MMP-12) have been identified with a biosensor-based screening strategy and a specifically designed fragment library. The interaction between fragments and three variants of the target and a reference protein with an active-site zinc ion was measured continuously by surface plasmon resonance. The developed experimental design overcame the inherent instability of MMP-12 and allowed the identification of fragments that interacted specifically with the active-site of MMP-12 but not with the reference protein. The interaction with MMP-12 for selected compounds were analyzed for concentration dependence and saturability. Compounds interacting distinctly with the target were further evaluated by an activity-based assay, verifying MMP-12 inhibition. Two effective inhibitors were identified, and the compound with highest affinity was confirmed to be a competitive inhibitor with an IC50 of 290 nM and a ligand efficiency of 0.7 kcal/mol heavy atom. This procedure integrates selectivity and binding site identification into the screening procedure and does not require structure determination.
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| 4. |
- Bengtsson, Karin, et al.
(författare)
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Cardiac conduction disturbances in patients with ankylosing spondylitis : results from a 5-year follow-up cohort study
- 2019
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Ingår i: RMD Open. - : BMJ Publishing Group Ltd. - 2056-5933. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To describe electrocardiographic (ECG) development in patients with ankylosing spondylitis (AS) and identify associations between baseline characteristics and cardiac conduction disturbances (CCD) at 5-year follow-up.Methods: In a longitudinal cohort study, 172 patients (54% men, mean age (SD) of 50 (13) years at baseline) with AS underwent ECG, physical examination, questionnaires and laboratory testing at baseline and at 5-year follow-up. Descriptive statistics and univariate and age- and sex-adjusted logistic regression analyses were used. CCD included both atrioventricular and intraventricular blocks.Results: Twenty-three of the 172 patients (13.4%) had a CCD at follow-up. Eight patients had developed a new CCD and eight had normalised their ECG. In the age- and sex-adjusted analyses, CCD at baseline (OR 24.8, 95% CI 7.3 to 84.5), male sex (OR 6.4, 95% CI 2.0 to 20.8), history of anterior uveitis (OR 4.4, 95% CI 1.3 to 14.5), higher ASDAS-CRP (OR 2.3, 95% CI 1.3 to 4.0), greater waist circumference (OR 1.3, 95% CI 1.1 to 1.6, per 5 cm), and medication with antiplatelets (OR 7.0, 95% CI 1.5 to 31.8) and beta-blockers (OR 3.4, 95% CI 1.0 to 11.5) were associated with a CCD at follow-up. Higher age and longer symptom duration were highly correlated and were both associated with a CCD at follow-up.Conclusions: The presence of CCD in AS is in part dynamic and associated with both AS and non-AS characteristics. Our results suggest that patients especially prone to present with CCDs are older men with a previous CCD, longer symptom duration, higher AS disease activity, a history of anterior uveitis and medication reflecting cardiovascular disease.
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| 5. |
- Cheng, Qing, et al.
(författare)
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Preclinical PET imaging of EGFR levels : pairing a targeting with a non-targeting Sel-tagged Affibody-based tracer to estimate the specific uptake
- 2016
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Ingår i: EJNMMI Research. - : Springer. - 2191-219X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Though overexpression of epidermal growth factor receptor (EGFR) in several forms of cancer is considered to be an important prognostic biomarker related to poor prognosis, clear correlations between biomarker assays and patient management have been difficult to establish. Here, we utilize a targeting directly followed by a non-targeting tracer-based positron emission tomography (PET) method to examine some of the aspects of determining specific EGFR binding in tumors. Methods: The EGFR-binding Affibody molecule Z(EGFR:2377) and its size-matched non-binding control Z(Taq:3638) were recombinantly fused with a C-terminal selenocysteine-containing Sel-tag (Z(EGFR:2377)-ST and Z(Taq:3638)-ST). The proteins were site-specifically labeled with DyLight488 for flow cytometry and ex vivo tissue analyses or with C-11 for in vivo PET studies. Kinetic scans with the C-11-labeled proteins were performed in healthy mice and in mice bearing xenografts from human FaDu (squamous cell carcinoma) and A431 (epidermoid carcinoma) cell lines. Changes in tracer uptake in A431 xenografts over time were also monitored, followed by ex vivo proximity ligation assays (PLA) of EGFR expressions. Results: Flow cytometry and ex vivo tissue analyses confirmed EGFR targeting by ZE(GFR:2377)-ST-DyLight488. [Methyl-C-11]-labeled Z(EGFR:2377)-ST-CH3 and Z(Taq:3638)-ST-CH3 showed similar distributions in vivo, except for notably higher concentrations of the former in particularly the liver and the blood. [Methyl-C-11]-Z(EGFR:2377)-ST-CH3 successfully visualized FaDu and A431 xenografts with moderate and high EGFR expression levels, respectively. However, in FaDu tumors, the non-specific uptake was large and sometimes equally large, illustrating the importance of proper controls. In the A431 group observed longitudinally, non-specific uptake remained at same level over the observation period. Specific uptake increased with tumor size, but changes varied widely over time in individual tumors. Total (membranous and cytoplasmic) EGFR in excised sections increased with tumor growth. There was no positive correlation between total EGFR and specific tracer uptake, which, since Z(EGFR:2377) binds extracellularly and is slowly internalized, indicates a discordance between available membranous and total EGFR expression levels. Conclusions: Same-day in vivo dual tracer imaging enabled by the Sel-tag technology and C-11-labeling provides a method to non-invasively monitor membrane-localized EGFR as well as factors affecting non-specific uptake of the PET ligand.
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| 6. |
- Forsblad-d'Elia, Helena, et al.
(författare)
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Cardiac conduction system abnormalities in ankylosing spondylitis : a cross-sectional study.
- 2013
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 14, s. 237-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiac conduction disturbances are common in spondyloarthropathies such as ankylosing spondylitis (AS). Whether their occurrence can be linked to signs and symptoms of rheumatic disease activity is an unsettled issue addressed in this study.METHODS: In this cross-sectional study patients with AS according to modified New York criteria but without psoriasis, inflammatory bowel disease, dementia, pregnancy, other severe diseases such as malignancy and difficulties in answering questionnaires were invited; and 210 participated (120 men), mean age 49 years (SD 13; range: 16-77). Questionnaires, physical examination, ECG, and laboratory tests were performed at the same visit.RESULTS: Cardiac conduction disturbances were common and diagnosed in 10-33%, depending on if conservative or less conservative predefined criteria were applied. They consisted mostly of 1st degree atrio-ventricular block and prolonged QRS duration, but one patient had a pacemaker and 7 more had complete bundle branch blocks. Conduction abnormalities were associated mainly with age, male gender and body weight, and not with laboratory measures of inflammation or with Bath Ankylosing Spondylitis Disease Activity Index. Neither were they associated with the presence of HLA B27, which was found in 87% of all patients; the subtype B270502 dominated in all patients.CONCLUSIONS: Cardiac conduction abnormalities are common in AS, but not associated with markers of disease activity or specific B27 subtypes. Even relatively mild conduction system abnormalities might, however, indirectly affect morbidity and mortality.
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| 7. |
- Hultcrantz, Elisabeth, et al.
(författare)
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Long-term effects of radiofrequency ablation of the soft palate on snoring.
- 2010
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Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - : Springer Science and Business Media LLC. - 1434-4726. ; 267:1, s. 137-142
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate short- and long-term effects of radiofrequency treatment of the soft palate on snoring. Twenty-nine patients with habitual snoring were studied prospectively and treated up to four times at 4-6 week intervals with an Ellman Surgitrone((R)). Electromyography (EMG) of m. palatoglossus was performed in ten patients. Patients and partners evaluated snoring, sleep quality and daytime sleepiness 1 week preoperatively, 6 months and 3-4 years postoperatively. Snoring was reduced postoperatively (P < 0.0001). Sleep time increased, daytime sleepiness was reduced, and the partners slept better after 6 months. However, 3-4 years postoperatively only 25% of patients were satisfied. Another 25% had received additional treatment. EMG was normal in 6/10 patients preoperatively. They all continued to snore postoperatively. Four patients had pathological EMGs; three were responders. In conclusion, radiofrequency treatment for snoring may lead to long-term improvement in one out of four cases. Pre-evaluation with EMG may predict the outcome.
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| 8. |
- Jonsson, Andreas, et al.
(författare)
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Generation of tumour-necrosis-factor-alpha-specific affibody molecules capable of blocking receptor binding in vitro
- 2009
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Ingår i: Biotechnology and applied biochemistry. - 0885-4513 .- 1470-8744. ; 54, s. 93-103
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Tidskriftsartikel (refereegranskat)abstract
- Affibody molecules specific for human TNF-alpha (tumour necrosis factor-alpha) were selected by phage-display technology from a library based on the 58-residue Protein A-derived Z domain. TNF-alpha is a proinflammatory cytokine involved in several inflammatory diseases and, to this day, four TNF-alpha-blocking protein pharmaceuticals have been approved for clinical use. The phage selection generated 18 unique cysteine-free affibody sequences of which 12 were chosen, after sequence cluster analysis, for characterization as proteins. Biosensor binding studies of the 12 Escherichia coli-produced and IMAC (immobilized-metal-ion affinity chromatography)-purified affibody molecules revealed three variants that demonstrated the strongest binding to human TNF-alpha. These three affibody molecules were subjected to kinetic binding analysis and also tested for their binding to mouse, rat and pig TNF-alpha. For Z(TNF alpha:185), subnanomolar affinity (K-D = 0.1-0.5 nM) for human TNF-alpha was demonstrated, as well as significant binding to TNF-alpha from the other species. Furthermore, the binding site was found to overlap with the binding site for the TNF-alpha receptor, since this interaction could be efficiently blocked by the Z(TNF-alpha:185) affibody. When investigating six dimeric affibody constructs with different linker lengths, and one trimeric construct, it was found that the inhibition of the TNF-alpha binding to its receptor could be further improved by using dinners with extended linkers and/or a trimeric affibody construct. The potential implication of the results for the future design of affibody-based reagents for the diagnosis of inflammation is discussed.
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| 9. |
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| 10. |
- Rodriguez-Wallberg, Kenny A., et al.
(författare)
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Ovarian tissue cryopreservation and transplantation among alternatives for fertility preservation in the Nordic countries - compilation of 20 years of multicenter experience
- 2016
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : WILEY-BLACKWELL. - 0001-6349 .- 1600-0412. ; 95:9, s. 1015-1026
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. The aim of this study is to report the current status of ovarian tissue cryopreservation among alternatives for fertility preservation in the Nordic countries. Material and methods. A questionnaire was sent to 14 Nordic academic reproductive centers with established fertility preservation programs. It covered fertility preservation cases performed up to December 2014, standard procedures for ovarian tissue cryopreservation and oocyte cryopreservation and reproductive outcomes following ovarian tissue transplantation. Results. Among the Nordic countries, Denmark and Norway practice ovarian tissue cryopreservation as a clinical treatment (822 and 164 cases, respectively) and their programs are centralized. In Sweden (457 cases), ovarian tissue cryopreservation is practiced at five of six centers and in Finland at all five centers (145 cases). Nearly all considered ovarian tissue cryopreservation to be experimental. In Iceland, embryo cryopreservation is the only option for fertility preservation. Most centers use slow-freezing methods for ovarian tissue cryopreservation. Most patients selected for ovarian tissue cryopreservation were newly diagnosed with cancer and the tissue was predominantly retrieved laparoscopically by unilateral oophorectomy. Only minor complications were reported. In total, 46 women have undergone ovarian tissue transplantation aiming at recovering fertility, 17 healthy children have been born and several additional pregnancies are currently ongoing. Whenever patients' clinical condition is permissive, oocyte cryopreservation after hormonal stimulation is preferred for fertility preservation. Between 2012 and 2014, a smaller proportion of females have undergone fertility preservation in the Nordic centers, in comparison to males (1: 3). Conclusions. Overall, ovarian tissue cryopreservation was reported to be safe. Slow freezing methods are still preferred. Promising results of recovery of fertility have been reported in Nordic countries that have initiated ovarian tissue transplantation procedures.
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