| 1. |
- Juhasz, Balazs, et al.
(författare)
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Peripheral quantitative computed tomography in the assessment of bone mineral density in anti-TNF-treated rheumatoid arthritis and ankylosing spondylitis patients
- 2021
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Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central (BMC). - 1471-2474. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) are associated with osteoporosis. There have not been many peripheral quantitative computed tomography (QCT) studies in patients receiving biologics. We assessed volumetric and areal bone mineral density (BMD) by forearm QCT and dual-energy X-ray absorptiometry (DXA), respectively in addition to laboratory biomarkers in these arthritides. Methods Forty RA and AS patients treated with either etanercept (ETN) or certolizumab pegol (CZP) were undergoing follow-ups for one year. Volumetric and areal BMD, as well as parathyroid hormone (PTH), osteocalcin, RANKL, 25-hydroxyvitamin D (VITD), P1NP, CTX, sclerostin (SOST), Dickkopf 1 (DKK-1) and cathepsin K (CATHK) were determined. Results We did not observe any further bone loss during the 12-month treatment period. Volumetric and areal BMD showed significant correlations with each other (p<0.017 after Bonferroni's correction). Trabecular QCT BMD at baseline (p=0.015) and cortical QCT BMD after 12 months (p=0.005) were inversely determined by disease activity at baseline in the full cohort. Trabecular QCT BMD at baseline also correlated with CTX (p=0.011). In RA, CRP negatively (p=0.014), while SOST positively (p=0.013) correlated with different QCT parameters. In AS, RANKL at baseline (p=0.014) and after 12 months (p=0.007) correlated with cortical QCT BMD. In the full cohort, 12-month change in QTRABBMD was related to TNF inhibition together with elevated VITD-0 levels (p=0.031). Treatment and lower CATHK correlated with QCORTBMD changes (p=0.006). In RA, TNF inhibition together with VITD-0 (p<0.01) or CATHK-0 (p=0.002), while in AS, treatment and RANKL-0 (p<0.05) determined one-year changes in QCT BMD. Conclusions BMD as determined by QCT did not change over one year of anti-TNF treatment. Disease activity, CATHK, RANKL and VITD may be associated with the effects of anti-TNF treatment on QCT BMD changes. RA and AS may differ in this respect.
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| 2. |
- Bagoly, Zsolt, et al.
(författare)
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Principal Component Analysis of Gamma-Ray Bursts' Spectra
- 2005
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Ingår i: Nuovo Cimento C. ; 28:3, s. 295-298
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Tidskriftsartikel (refereegranskat)abstract
- The origin of dark bursts--i.e. that have no observed afterglows in X-ray, optical/NIR and radio ranges--is unclear yet. Different possibilities--instrumental biases, very high redshifts, extinction in the host galaxies--are discussed and shown to be important. On the other hand, the dark bursts should not form a new subgroup of long gamma-ray bursts themselves.
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| 3. |
- Gulyas, Katalin, et al.
(författare)
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Effects of 1-year anti-TNF-α therapies on bone mineral density and bone biomarkers in rheumatoid arthritis and ankylosing spondylitis
- 2020
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Ingår i: Clinical Rheumatology. - : Springer Science and Business Media LLC. - 0770-3198 .- 1434-9949. ; 39:1, s. 167-175
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesRheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss. We conducted a comprehensive study using imaging (dual-energy X-ray absorptiometry, DXA) and laboratory biomarkers in order to determine bone health and to study the effects of anti-tumor necrosis factor (TNF) biologics in RA and AS.Patients and methodsThirty-six RA and 17 AS patients undergoing 1-year etanercept (ETN) or certolizumab-pegol (CZP) therapy were studied. Bone density was assessed by DXA at baseline and after 12 months. Serum C-reactive protein (CRP), calcium, phosphate, parathyroid hormone (PTH), vitamin D3, osteocalcin, procollagen type I N-propeptide (P1NP), C-terminal telopeptide (βCTX), osteoprotegerin, sclerostin (SOST), Dickkopf-1 (DKK-1), soluble receptor activator nuclear kappa B ligand (sRANKL), and cathepsin K (cathK) levels were determined at baseline and after 6 and 12 months.ResultsTNF-α inhibition was clinically effective. Anti-TNF-α halted further bone loss over 1 year. In general, anti-TNF therapy significantly increased P1NP, SOST levels, and the P1NP/βCTX ratios, while decreased DKK-1 and CathK production at different time points in most patient subsets. In the full cohort and in RA, baseline and/or 12-month bone mineral density (BMD) at multiple sites exerted inverse relationships with CRP and βCTX, and positive correlation with SOST. In AS, L2-4 BMD after 1-year biologic therapy inversely correlated with baseline βCTX, while femoral neck BMD rather showed inverse correlations with CRP.ConclusionsAnti-TNF therapy slowed down generalized bone loss, in association with clinical improvements, in both diseases. TNF blockade may enhance bone formation and suppress joint destruction. Anti-TNF therapy may act inversely on DKK-1 and SOST. Independent predictors of BMD were SOST and βCTX in RA, whilst CRP in AS.
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| 4. |
- Horváth, Attila, et al.
(författare)
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Histological evaluation of human intrabony periodontal defects treated with an unsintered nanocrystalline hydroxyapatite paste
- 2013
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Ingår i: Clinical Oral Investigations. - : Springer. - 1432-6981 .- 1436-3771. ; 17:2, s. 423-430
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The aim of the study was to clinically and histologically evaluate the healing of human intrabony defects treated with open flap surgery (OFD) and application of a new, resorbable, fully synthetic, unsintered, nanocrystalline, phase-pure hydroxyapatite (nano-HA). MATERIALS AND METHODS: Six patients, each of them displaying very advanced intrabony defects around teeth scheduled for extraction due to advanced chronic periodontitis and further prosthodontic considerations, were included in the study. Following local anaesthesia, mucoperiosteal flaps were reflected; the granulation tissue was removed, and the roots were meticulously debrided by hand and ultrasonic instruments. A notch was placed at the most apical extent of the calculus present on the root surface or at the most apical part of the defect (if no calculus was present) in order to serve as a reference for the histological evaluation. Following defect fill with nano-HA, the flaps were sutured by means of mattress sutures to allow primary intention healing. At 7 months after regenerative surgery, the teeth were extracted together with some of their surrounding soft and hard tissues and processed for histological analysis. RESULTS: The postoperative healing was uneventful in all cases. At 7 months following surgery, mean PPD reduction and mean CAL gain measured 4.0 ± 0.8 and 2.5 ± 0.8 mm, respectively. The histological analysis revealed a healing predominantly characterized by epithelial downgrowth. Limited formation of new cementum with inserting connective tissue fibers and bone regeneration occurred in three out of the six biopsies (i.e. 0-0.86 and 0-1.33 mm, respectively). Complete resorption of the nano-HA was found in four out of the six biopsies. A few remnants of the graft particles (either surrounded by newly formed mineralized tissue or encapsulated in connective tissue) were found in two out of the six biopsies. CONCLUSION: Within their limits, the present results indicate that nano-HA has limited potential to promote periodontal regeneration in human intrabony defects. CLINICAL RELEVANCE: The clinical outcomes obtained following surgery with OFD + nano-HA may not reflect true periodontal regeneration.
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| 5. |
- Horváth, Attila, et al.
(författare)
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Histologisk evaluering af humane intraossøse parodontale defekter behandlet med en usintret nanokrystallinsk hydroxyapatit pasta
- 2013
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Ingår i: Tandlægebladet. - : Dansk Tandlægeforening. - 0039-9353. ; 117:1, s. 12-13
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Formål Formålet med undersøgelsen var at evaluere den kliniske og histologiske heling af humane intraossøse defekter behandlet med konventionel flapkirurgi (OFD) og anvendelse af en ny, resorberbar, fuldsyntetisk, usintret, nanokrystallinsk, hydroxyapatit (nano-HA ). Materialer og metoder Seks patienter, som hver viste en meget avanceret intraossøs defekt omkring en tand planlagt til ekstraktion på grund af svær kronisk marginal parodontitis og yderligere restaurerende overvejelser, blev inkluderet i undersøgelsen. Efter lokalbedøvelse, mucoperiosteal lapløft, granulationsvævs fjernelse og omhyggelig roddepuration og afglatning med hånd- og ultralydsinstrumenter blev der på roden placeret et mindre boremærke ved den mest apikale tilstedeværelse af tandsten eller ved bunden af defekten (hvis ikke tandsten var til stede); boremærket tjente som reference ved den histologiske evaluering. Efter defektudfyldelse med nano-HA blev lapperne syet ved hjælp af madras-suturer mhp. primær heling. Syv måneder efter regenerativ kirurgi blev tænderne ekstraheret sammen med en mindre del af de omgivende bløde og hårde væv og præpareret til histologisk undersøgelse. Resultater Postoperativ heling var komplikationsfri i alle tilfælde. Syv måneder efter operationen sås der betydelig pochedybdereduktion og klinisk fæstegevinst på 4,0 mm ± 0,8 mm og 2,5 mm ± 0,8 mm, henholdsvis. Den histologiske analyse viste, at helingen hovedsageligt kendetegnede sig ved et lang epitelialt fæste. Begrænset dannelse af ny cement med indlejrede kollagenfibre og knogleregeneration sås hos tre ud af de seks biopsier på op til henholdsvis 0,86 mm og 1,33 mm. Komplet resorption af nano-HA-partikler blev fundet i fire ud af de seks biopsier. Nogle få rester af de implanterede partikler (enten omgivet af nydannet mineraliseret væv eller indkapslet i bindevæv) blev fundet i to ud af de seks biopsier. Konklusion De foreliggende resultater viser, at nano-HA har begrænset mulighed for at fremme parodontal regeneration i humane intraossøse defekter. Klinisk relevans: De kliniske resultater opnået efter kirurgi med OFD + nano-HA afspejler måske ikke ægte parodontal regeneration. Horváth A, Stavropoulos A, Windisch P et al. Histological evaluation of human intrabony periodontal defects treated with an unsintered nanocrystalline hydroxyapatite paste. Clin Oral Investig 2012.
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| 6. |
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| 7. |
- Horváth, Attila, et al.
(författare)
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Mild and Efficient Palladium(II)-Catalyzed Racemization of Allenes
- 2004
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Ingår i: Chemical Communications. - : Royal Society of Chemistry. - 1359-7345 .- 1364-548X. ; :8, s. 964-965
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Tidskriftsartikel (refereegranskat)abstract
- Allenes undergo racemization in the presence of catalytic amounts of Pd(OAc)2/LiBr under mild conditions; the reaction proceeds via a bromopalladation–debromopalladation sequence and tolerates various functional groups.
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| 8. |
- Horváth, Attila, 1975-
(författare)
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Palladium(II)-Catalyzed Reactions of Allenes with Lithium Bromide and Cyclization of α-Amino Allenes to Pyrrolines
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is based on three novel palladium(II)-catalyzed reactions of allenes with lithium bromide and a bromonium ion induced cyclization of allenyl amides to pyrrolines. In Paper I a 1,2-functionalization of allenes is presented where bromide adds as a first nucleophile followed by intramolecular attack by an oxygen or nitrogen nucleophile. Chapter 2 deals with the extension of this reaction to different nitrogen nucleophiles such as urea, carbamate, and N-tosyl carbamate providing access to substituted pyrrolidines and oxazolidines in good yields under mild reaction conditions.Paper II deals with a stereoconvergent, palladium(II)-catalyzed SN2’ reaction of α-acetoxy allenes with bromide as nucleophile. In this reaction substituted (Z,E)-2-bromo-1,3-dienes are produced in good yields with excellent diastereo-selectivity.Paper III describes a mild racemization reaction of chiral allenes. The effect of the functional group present in the molecule on the reaction rate is examined. All these reactions published in Papers I-III proceed through a common intermediate: a 2-bromo-(π-allyl)palladium complex.The fourth paper describes a simple, efficient, and enantiocontrolled cyclization of N-protected α-allenyl amines with N-bromosuccinimide (NBS) to afford 3-bromo-pyrrolines. The synthesis of optically active 2,5-dehydroprolinol derivative is also described. The mechanism, scope, and limitations of all four reactions are discussed in this thesis.
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| 9. |
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| 10. |
- Horváth, Attila, et al.
(författare)
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Simple, Enantiocontrolled Synthesis of 3-Pyrrolines from α-Amino Allenes
- 2004
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Ingår i: European Journal of Organic Chemistry. - : wiley. - 1434-193X .- 1099-0690. ; 2004:15, s. 3240-3243
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Tidskriftsartikel (refereegranskat)abstract
- Cyclization of -amino allenes in the presence of N-bromosuccinimide afforded pyrrolines in good yields. The products were obtained with high enantiomeric excesses when optically active allenes were used as substrates. The synthesis of a 2,5-dehydroprolinol derivative is also presented.
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