| 1. |
- Budde, U, et al.
(författare)
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Detailed von Willebrand factor multimer analysis in patients with von Willebrand disease in the European study, molecular and clinical markers for the diagnosis and management of type 1 von Willebrand disease (MCMDM-1VWD)
- 2008
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 6:5, s. 762-771
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Tidskriftsartikel (refereegranskat)abstract
- Background: Type 1 von Willebrand disease (VWD) is a congenital bleeding disorder characterized by a partial quantitative deficiency of plasma von Willebrand factor (VWF) in the absence of structural and/or functional VWF defects. Accurate assessment of the quantity and quality of plasma VWF is difficult but is a prerequisite for correct classification. Objective: To evaluate the proportion of misclassification of patients historically diagnosed with type 1 VWD using detailed analysis of the VWF multimer structure. Patients and methods: Previously diagnosed type 1 VWD families and healthy controls were recruited by 12 expert centers in nine European countries. Phenotypic characterization comprised plasma VWF parameters and multimer analysis using low- and intermediate-resolution gels combined with an optimized visualization system. VWF genotyping was performed in all index cases (ICs). Results: Abnormal multimers were present in 57 out of 150 ICs; however, only 29 out of these 57 (51%) had VWF ristocetin cofactor to antigen ratio below 0.7. In most cases multimer abnormalities were subtle, and only two cases had a significant loss of the largest multimers. Conclusions: Of the cases previously diagnosed as type 1 VWD, 38% showed abnormal multimers. Depending on the classification criteria used, 22 out of these 57 cases (15% of the total cohort) may be reclassified as type 2, emphasizing the requirement for multimer analysis compared with a mere ratio of VWF functional parameters and VWF:Ag. This is further supported by the finding that even slightly aberrant multimers are highly predictive for the presence of VWF mutations.
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| 2. |
- Eikenboom, J, et al.
(författare)
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Linkage analysis in families diagnosed with type 1 von Willebrand disease in the European study, molecular and clinical markers for the diagnosis and management of type 1 VWD
- 2006
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 4:4, s. 774-782
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Tidskriftsartikel (refereegranskat)abstract
- Background: von Willebrand disease (VWD) type 1 is a congenital bleeding disorder caused by genetic defects in the von Willebrand factor (VWF) gene and characterized by a reduction of structurally normal VWF. The diagnosis of type 1 VWD is difficult because of clinical and laboratory variability. Furthermore, inconsistency of linkage between type 1 VWD and the VWF locus has been reported. Objectives: To estimate the proportion of type 1 VWD that is linked to the VWF gene. Patients and methods: Type 1 VWD families and healthy control individuals were recruited. An extensive questionnaire on bleeding symptoms was completed and phenotypic tests were performed. Linkage between VWF gene haplotypes and the diagnosis of type 1 VWD, the plasma levels of VWF and the severity of bleeding symptoms was analyzed. Results: Segregation analysis in 143 families diagnosed with type 1 VWD fitted a model of autosomal dominant inheritance. Linkage analysis under heterogeneity resulted in a summed lod score of 23.2 with an estimated proportion of linkage of 0.70. After exclusion of families with abnormal multimer patterns the linkage proportion was 0.46. LOD scores and linkage proportions were higher in families with more severe phenotypes and with phenotypes suggestive of qualitative VWF defects. About 40% of the total variation of VWF antigen could be attributed to the VWF gene. Conclusions: We conclude that the diagnosis of type 1 VWD is linked to the VWF gene in about 70% of families, however after exclusion of qualitative defects this is about 50%.
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| 3. |
- Sadler, J. E., et al.
(författare)
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Update on the pathophysiology and classification of von Willebrand disease: a report of the Subcommittee on von Willebrand Factor
- 2006
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 4:10, s. 2103-2114
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Forskningsöversikt (refereegranskat)abstract
- von Willebrand disease (VWD) is a bleeding disorder caused by inherited defects in the concentration, structure, or function of von Willebrand factor (VWF). VWD is classified into three primary categories. Type 1 includes partial quantitative deficiency, type 2 includes qualitative defects, and type 3 includes virtually complete deficiency of VWF. VWD type 2 is divided into four secondary categories. Type 2A includes variants with decreased platelet adhesion caused by selective deficiency of high-molecular-weight VWF multimers. Type 2B includes variants with increased affinity for platelet glycoprotein Ib. Type 2M includes variants with markedly defective platelet adhesion despite a relatively normal size distribution of VWF multimers. Type 2N includes variants with markedly decreased affinity for factor VIII. These six categories of VWD correlate with important clinical features and therapeutic requirements. Some VWF gene mutations, alone or in combination, have complex effects and give rise to mixed VWD phenotypes. Certain VWD types, especially type 1 and type 2A, encompass several pathophysiologic mechanisms that sometimes can be distinguished by appropriate laboratory studies. The clinical significance of this heterogeneity is under investigation, which may support further subdivision of VWD type 1 or type 2A in the future.
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| 4. |
- Tosetto, A, et al.
(författare)
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A quantitative analysis of bleeding symptoms in type 1 von Willebrand disease: results from a multicenter European study (MCMDM-1 VWD)
- 2006
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 4:4, s. 766-773
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Tidskriftsartikel (refereegranskat)abstract
- Background: A quantitative description of bleeding symptoms in type 1 von Willebrand disease (VWD) has never been reported. Objectives: The aim was to quantitatively evaluate the severity of bleeding symptoms in type 1 VWD and its correlation with clinical and laboratory features. Patients and methods: Bleeding symptoms were retrospectively recorded in a European cohort of VWD type 1 families, and for each subject a quantitative bleeding score (BS) was obtained together with phenotypic tests. Results: A total of 712 subjects belonging to 144 families and 195 controls were available for analysis. The BS was higher in index cases than in affected family members (BS 9 vs. 5, P < 0.0001) and in unaffected family members than in controls (BS 0 vs. -1, P < 0.0001). There was no effect of ABO blood group. BS showed a strong significant inverse relation with either von Willebrand ristocetin cofactor (VWF:RCo), von Willebrand antigen (VWF:Ag) or factor VIII procoagulant activity (FVIII:C) measured at time of enrollment, even after adjustment for age, sex and blood group (P < 0.001 for all the four upper quintiles of BS vs. the first quintile, for either VWF:RCo, VWF:Ag or FVIII:C). Higher BS was related with increasing likelihood of VWD, and a mucocutaneous BS (computed from spontaneous, mucocutaneous symptoms) was strongly associated with bleeding after surgery or tooth extraction. Conclusions: Quantitative analysis of bleeding symptoms is potentially useful for a more accurate diagnosis of type 1 VWD and to develop guidelines for its optimal treatment.
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| 5. |
- Tosetto, A., et al.
(författare)
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Impact of plasma von Willebrand factor levels in the diagnosis of type 1 von Willebrand disease: results from a multicenter European study (MCMDM-1VWD)
- 2007
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 5:4, s. 715-721
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Tidskriftsartikel (refereegranskat)abstract
- Background: Presence of bleeding symptoms, inheritance and reduced von Willebrand factor (VWF) contribute to the diagnosis of type 1 von Willebrand disease (VWD). However, quantitative analysis of the importance of VWF antigen (VWF:Ag) and ristocetin cofactor activity (VWF:RCo) levels in the diagnosis is lacking. Objectives: To evaluate the relative contribution of VWF measurement to the diagnosis of VWD. Patients and methods: From the MCMDM-1VWD study cohort, 204 subjects (considered as affected by VWD based on the enrolling Center diagnoses and the presence of linkage with the VWF locus) were compared with 1155 normal individuals. Sensitivity, specificity and diagnostic positive likelihood ratios (LR) of VWF:Ag and VWF:RCo were computed. Results: ABO blood group was the variable most influencing VWF levels, but adjustment of the lower reference limit for the ABO group did not improve sensitivity and specificity of VWF:Ag or VWF:RCo. The lower reference limit (2.5th percentile) was 47 IU dL(-1) for both VWF:Ag and VWF:RCo and showed similar diagnostic performance [receiver-operator curve area: 0.962 and 0.961 for VWF:Ag and VWF:RCo, respectively; P = 0.81]. The probability of VWD was markedly increased only for values below 40 IU dL(-1) (positive LR: 95.1 for VWF:Ag), whereas intermediate values (40 to 60 IU dL(-1)) of VWF only marginally indicated the probability of VWD. Conclusions: Although the conventional 2.5 lower percentile has good sensitivity and specificity, only VWF:Ag or VWF:RCo values below 40 IU dL(-1) appear to significantly indicate the likelihood of type 1 VWD. The LR profile of VWF level could be used in a diagnostic algorithm.
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| 6. |
- Vincenti, F., et al.
(författare)
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Results of an international, randomized trial comparing glucose metabolism disorders and outcome with cyclosporine versus tacrolimus
- 2007
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Ingår i: American journal of transplantation. - : Elsevier BV. - 1600-6135. ; 7:6, s. 1506-14
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Tidskriftsartikel (refereegranskat)abstract
- DIRECT (Diabetes Incidence after Renal Transplantation: Neoral C(2) Monitoring Versus Tacrolimus) was a 6-month, open-label, randomized, multicenter study which used American Diabetes Association/World Health Organization criteria to define glucose abnormalities. De novo renal transplant patients were randomized to cyclosporine microemulsion (CsA-ME, using C(2) monitoring) or tacrolimus, with mycophenolic acid, steroids and basiliximab. The intent-to-treat population comprised 682 patients (336 CsA-ME, 346 tacrolimus): 567 were nondiabetic at baseline. Demographics, diabetes risk factors and steroid doses were similar between treatment groups. The primary safety endpoint, new-onset diabetes after transplant (NODAT) or impaired fasting glucose (IFG) at 6 months, occurred in 73 CsA-ME patients (26.0%) and 96 tacrolimus patients (33.6%, p = 0.046). The primary efficacy endpoint, biopsy-proven acute rejection, graft loss or death at 6 months, occurred in 43 CsA-ME patients (12.8%) and 34 tacrolimus patients (9.8%, p = 0.211). Mean glomerular filtration rate (Cockcroft-Gault) was 63.6 +/- 20.7 mL/min/1.73 m(2) in the CsA-ME cohort and 65.9 +/- 23.1 mL/min/1.73 m(2) with tacrolimus (p = 0.285); mean serum creatinine was 139 +/- 58 and 133 +/- 57 mumol/L, respectively (p = 0.005). Blood pressure was similar between treatment groups at month 6, but total cholesterol, LDL-cholesterol and triglyceride levels were significantly higher with CsA than with tacrolimus (total cholesterol:HDL remained unchanged). The profile and incidence of adverse events were similar between treatments. The incidence of NODAT or IFG at 6 months post-transplant is significantly lower with CsA-ME than with tacrolimus without a significant difference in short-term outcome.
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| 7. |
- Granville, S, et al.
(författare)
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Optical conductivity and x-ray absorption and emission study of the band structure of MnN films
- 2005
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 72:20, s. 205127-
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Tidskriftsartikel (refereegranskat)abstract
- The band structure of MnN films prepared by ion assisted deposition has been investigated by optical conductivity and x-ray absorption and emission spectroscopies. X-ray diffraction and extended x-ray absorption fine structure show the films to be nanocrystalline but phase pure and exhibiting the known antiferromagnetic distorted rocksalt phase. X-ray emission spectroscopy of the N K-edge and x-ray absorption near edge spectroscopy of both the N K- and Mn L-edges are used to probe the occupied and empty densities of states, which compare well with the N(2p) and Mn(3d) partial densities of states calculated using the linearized muffin-tin orbital band structure method. A similar comparison is made between the measured optical conductivity and the calculated contribution from interband transitions. It is possible to associate the main features in the measured spectrum with corresponding ones in the calculated optical function. The major differences between calculated and measured spectra can be understood on the basis of a limited electron mean-free-path in these nanocrystalline films, which broadens the features in the joint density of states and relaxes the momentum conservation requirement. The calculated optical functions are analyzed in detail in terms of their dominant band-to-band contributions and in addition the polarization dependence is predicted. Temperature dependent conductivity measurements are also reported and show a clear metallic behavior and a weak Kondo-like low temperature anomaly.
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| 8. |
- Schneppenheim, Reinhard, et al.
(författare)
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A common origin of the 4143insA ADAMTS13 mutation
- 2006
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Ingår i: Thrombosis and Haemostasis. - 0340-6245. ; 96:1, s. 3-6
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Tidskriftsartikel (refereegranskat)abstract
- Severely deficient activity of the von Willebrand Factor (VWF) cleaving metalloprotease,ADAMTS 13, is associated with thrombotic thrombocytopenic purpura (TTP). The mutation spectrum ofADAMTS 13 is rather heterogeneous, and numerous mutations spread across the gene have been described in association with congenital TTP. The 4143insA mutation is unusual with respect to its geographic concentration. Following the initial report from Germany in which the 4143insA mutation was detected in four apparently unrelated families, we have now identified this mutation in a further eleven patients from Norway, Sweden, Poland, Germany, the Czech Republic and Australia. Confirmation that the Australian patient is of German ancestry, together with the Northern and Central European origin of most of the other patients, suggests that the 4143insA mutation has a common genetic background.We established ADAMTS 13 haplotypes by analyzing 17 polymorphic intragenic markers.The haplotypes linked to 4143insA were identical in all informative families. Three novel candidate mutations, C347S, P67IL and RI060W, as well as the known mutation R507Q, were also identified during the course of the study.We conclude that 4143insA has a common genetic background and is frequent among patients with hereditary ADAMTS 13 deficiency in Northern and Central European countries.
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| 9. |
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| 10. |
- Weltzien, Hans Ulrich, et al.
(författare)
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Safe cosmetics without animal testing? Contributions of the EU Project Sens-it-iv
- 2009
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Ingår i: Journal für Verbraucherschütz und Lebensmittelsicherheit. - : Springer Science and Business Media LLC. - 1661-5867 .- 1661-5751. ; 4:suppl. 2, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- The 7th Ammendment to the Cosmetics Directive of the European Commission (Directive 76/768/EEC2) bans the marketing of cosmetics containing animal-tested ingredients since March 2009. Excepted are only tests for repeated dose toxicity, for which the animal ban will come into effect by 2013. One major concern for cosmetics, i.e. the risk of containing skin (contact) sensitizers, has in the past been addressed almost exclusively by animal testing. It is this problem attracting the central interest of the integrated research project Sens-it-iv (Novel Testing Strategies for in vitro Assessment of Allergens, http://www.sens-it-iv.eu ), funded by the EC within framework 6 since October 2005. Here, the 28 Sens-it-iv partners from 10 European States present the 5 most promising types of in vitro assays selected for further refinement. These are: (1) a human epidermal equivalent (EE) model to rank contact allergens according to their sensitizing potency, (2) identification of contact sensitizers, including pro-haptens, through intracellular production of IL-18 by the human keratinocyte cell line NCTC 2544, (3) determination of activation markers such as CD86, CD54 and most prominently CXCL8 (IL-8) on/in dendritic cell lines, (4) contact sensitizer-specific migration of MUTZ Langerhans cells towards the chemokine CXCL12, and (5) the allergen-specific activation and proliferation of na < ve human T cells. Ongoing genomic and proteomic experiments are in the process of identifying larger sensitizer-specific biological marker signatures to be integrated into the above assays. We hope to supply the European control agencies with a basis for further validation of in vitro assays by the end of 2010.
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