168 research outputs found
The influence of the preparation methods on the inclusion of model drugs in a β-cyclodextrin cavity
NOTICE: this is the author’s version of a work that was accepted for publication in European Journal of Pharmaceutics and Biopharmaceutics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Eur J Pharm Biopharm. 2009 Feb;71(2):377-386. Epub 2008 Oct 17.The work aims to prove the complexation of two model drugs (ibuprofen, IB and indomethacin, IN) by bcyclodextrin
(bCD), and the effect of water in such a process, and makes a comparison of their complexation
yields. Two methods were considered: kneading of a binary mixture of the drug, bCD, and inclusion
of either IB or IN in aqueous solutions of bCD. In the latter method water was removed by air stream,
spray-drying and freeze-drying. To prove the formation of complexes in final products, optical microscopy,
UV spectroscopy, IR spectroscopy, DSC, X-ray and NMR were considered. Each powder was added
to an acidic solution (pH = 2) to quantify the concentration of the drug inside bCD cavity. Other media
(pH = 5 and 7) were used to prove the existence of drug not complexed in each powder, as the drugs solubility
increases with the pH. It was observed that complexation occurred in all powders, and that the
fraction of drug inside the bCD did not depend neither on the method of complexation nor on the
processes of drying considered
Bactrial osteomyelitis and arthritis in Icelandic children 1996-2005
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn Skoða/Opna(view/open)Objective: The main objective was to determine the incidence and causative pathogens of osteomyelitis and septic arthritis in Icelandic children, as well as presenting symptoms and diagnosis. Methods: A nationwide retrospective review was done of all children <18 year old, 1996-2005. Subjects were divided into three equal age groups, 0-5, 6-11 and 12-17 years old. Cultures were reviewed and postive and negative cases compared. Results: Over the study period 220 cases were identified, 161 osteomyelitis and 59 septic arthritis cases. The incidence increased significantly over the period (p=0.019), mostly in the youngest age group (p<0.001) with osteomyelitis. Incidence of cases with a pathogen identified was unchanged over the period while culture negative cases increased significantly (p<0.001). Median age for osteomyelitis (6,1 years) was higher than in cases of septic arthitis (1,8 years) (p=0.003). A pathogen was identified in 59% of cases with osteomyelitis and 44% with septic arthritis. S. aureus was most common (65% and 27%, respectively) and K. kingae was second most common pathogen (7% and 11%, respectively). Methicillin resistant S. aureus was not identified. The tibia and knee were the predominant sites for osteomyelitis and septic arthritis respectively. Conclusions: An increased incidence was found in the youngest age group with osteomyelitis, especially in cases without a pathogen identified. The most commonly cultured pathogen was S. aureus, followed by K. kingae. A more sensitive technique to identify pathogens might be indicated in culture negative cases.Tilgangur: Markmið rannsóknarinnar var að kanna nýgengi, sýkingarvalda, einkenni og greiningaraðferðir beina- og liðasýkinga í börnum á Íslandi. Efniviður og aðferðir: Rannsóknin var afturskyggn og náði til barna yngri en 18 ára sem lögðust inn vegna sýkinganna á tímabilinu 1996-2005. Upplýsingum var safnað úr sjúkraskrám. Tilfellum var skipt í þrjá jafna aldurshópa, 0-5 ára, 6-11 ára og 12-17 ára. Niðurstöður ræktana voru metnar og einnig breytingar á nýgengi á tímabilinu. Niðurstöður: Á tímabilinu greindust 220 tilfelli, 161 með beinasýkingu og 59 með liðasýkingu. Nýgengi jókst marktækt á tímabilinu (p=0,019). Nýgengisaukningin var nær eingöngu bundin við beinasýkingar hjá yngsta aldurshópnum. Nýgengi þar sem ræktun var jákvæð breyttist ekki en nýgengi með neikvæða ræktun jókst marktækt (p<0,001). Miðgildi aldurs sjúklinga með beinasýkingar (6,1 ára) var hærri en þeirra með liðasýkingar (1,8 ára) (p=0,003). Í 59% beinasýkinga og 44% liðasýkinga greindist baktería, S. aureus var algengust (65% beinasýkinga og 27% liðasýkinga), því næst K. kingae (7% beinasýkinga og 11% liðasýkinga). Methicillin- ónæmir S. aureus greindust ekki. Sköflungur (20%) og hnéliður (47%) voru algengustu staðir sýkinganna. Ályktanir: Rannsóknin varpar ljósi á mikilvæga þætti beina- og liðasýkinga á Íslandi. Nýgengið vex í yngsta aldurshópnum, einkum þar sem ræktun er neikvæð. Algengasti orsakavaldur er S. aureus,svo K. kingae. Meðalaldur, kynjahlutfall og staðsetning sýkinga er sambærilegt við erlendar rannsóknir. Þörf er á næmari sýklafræðilegum greiningaraðferðum hjá þeim sem eru með neikvæðar ræktanir
Whole genome characterization of sequence diversity of 15,220 Icelanders
Understanding of sequence diversity is the cornerstone of analysis of genetic disorders, population genetics, and evolutionary biology. Here, we present an update of our sequencing set to 15,220 Icelanders who we sequenced to an average genome-wide coverage of 34X. We identified 39,020,168 autosomal variants passing GATK filters: 31,079,378 SNPs and 7,940,790 indels. Calling de novo mutations (DNMs) is a formidable challenge given the high false positive rate in sequencing datasets relative to the mutation rate. Here we addressed this issue by using segregation of alleles in three-generation families. Using this transmission assay, we controlled the false positive rate and identified 108,778 high quality DNMs. Furthermore, we used our extended family structure and read pair tracing of DNMs to a panel of phased SNPs, to determine the parent of origin of 42,961 DNMs.Peer Reviewe
COPA syndrome in an Icelandic family caused by a recurrent missense mutation in COPA
Background: Rare missense mutations in the gene encoding coatomer subunit alpha (COPA) have recently been
shown to cause autoimmune interstitial lung, joint and kidney disease, also known as COPA syndrome, under a
dominant mode of inheritance.
Case presentation: Here we describe an Icelandic family with three affected individuals over two generations with
a rare clinical presentation of lung and joint disease and a histological diagnosis of follicular bronchiolitis. We performed
whole-genome sequencing (WGS) of the three affected as well as three unaffected members of the family, and searched
for rare genotypes associated with disease using 30,067 sequenced Icelanders as a reference population. We assessed all
coding and splicing variants, prioritizing variants in genes known to cause interstitial lung disease. We detected a
heterozygous missense mutation, p.Glu241Lys, in the COPA gene, private to the affected family members. The
mutation occurred de novo in the paternal germline of the index case and was absent from 30,067 Icelandic
genomes and 141,353 individuals from the genome Aggregation Database (gnomAD). The mutation occurs
within the conserved and functionally important WD40 domain of the COPA protein.
Conclusions: This is the second report of the p.Glu241Lys mutation in COPA, indicating the recurrent nature of the
mutation. The mutation was reported to co-segregate with COPA syndrome in a large family from the USA with five
affected members, and classified as pathogenic. The two separate occurrences of the p.Glu241Lys mutation in cases and
its absence from a large number of sequenced genomes confirms its role in the pathogenesis of the COPA syndrome.
Keywords: COPA syndrome, Lung disease, Arthritis, Immune dysregulation, Case reportPeer Reviewe
Chitosan-hydroxycinnamic acid conjugates: Optimization of the synthesis and investigation of the structure activity relationship
A new synthesis method was developed and optimized by a full factorial design for conjugating hydroxycinnamic
acids (HCA-s) to chitosan. Cinnamic acid and tert-butyldimethylsilyl protected HCA-s were converted to their
corresponding acyl chlorides and reacted with 3,6-di-O-tert-butyldimethylsilyl-chitosan to selectively form amide
linkages, resulting in water-soluble conjugates after deprotection. Nineteen conjugates were obtained with
various degrees of substitution (DS) ranging from 3% to 60%. The conjugates were found to be bactericidal
against Staphylococcus aureus and Escherichia coli, with their activities equal to chitosan at low DS but an increase
in the DS correlated with reduced activity. DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay was performed to determine the EC50 values. Chitosan only exhibited low antioxidant activity, whereas the HCAchitosan conjugates exhibited higher antioxidant activities correlating with the DS. One caffeic acid conjugate
(21%) was 4000 times more active than chitosan and more active than free caffeic acid.The research work was funded by the Icelandic Research Fund
(Rannis Grant No. 185188-053) and by a doctoral grant from the University of Iceland research fund.Pre-print (óritrýnt handrit
Fourteen sequence variants that associate with multiple sclerosis discovered by meta-analysis informed by genetic correlations
A meta-analysis of publicly available summary statistics on multiple sclerosis combined with three Nordic multiple sclerosis cohorts (21,079 cases, 371,198 controls) revealed seven sequence variants associating with multiple sclerosis, not reported previously. Using polygenic risk scores based on public summary statistics of variants outside the major histocompatibility complex region we quantified genetic overlap between common autoimmune diseases in Icelanders and identified disease clusters characterized by autoantibody presence/absence. As multiple sclerosis-polygenic risk scores captures the risk of primary biliary cirrhosis and vice versa (P = 1.6 x 10(-7), 4.3 x 10(-9)) we used primary biliary cirrhosis as a proxy-phenotype for multiple sclerosis, the idea being that variants conferring risk of primary biliary cirrhosis have a prior probability of conferring risk of multiple sclerosis. We tested 255 variants forming the primary biliary cirrhosis-polygenic risk score and found seven multiple sclerosis-associating variants not correlated with any previously established multiple sclerosis variants. Most of the variants discovered are close to or within immune-related genes. One is a low-frequency missense variant in TYK2, another is a missense variant in MTHFR that reduces the function of the encoded enzyme affecting methionine metabolism, reported to be dysregulated in multiple sclerosis brain.publishedVersio
A homozygous loss-of-function mutation leading to CYBC1 deficiency causes chronic granulomatous disease
Publisher's version (útgefin grein)
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.Mutations in genes encoding subunits of the phagocyte NADPH oxidase complex are
recognized to cause chronic granulomatous disease (CGD), a severe primary immunodeficiency. Here we describe how deficiency of CYBC1, a previously uncharacterized protein in
humans (C17orf62), leads to reduced expression of NADPH oxidase’s main subunit (gp91phox)
and results in CGD. Analyzing two brothers diagnosed with CGD we identify a homozygous
loss-of-function mutation, p.Tyr2Ter, in CYBC1. Imputation of p.Tyr2Ter into 155K chipgenotyped Icelanders reveals six additional homozygotes, all with signs of CGD, manifesting
as colitis, rare infections, or a severely impaired PMA-induced neutrophil oxidative burst.
Homozygosity for p.Tyr2Ter consequently associates with inflammatory bowel disease (IBD)
in Iceland (P = 8.3 × 10−8; OR = 67.6), as well as reduced height (P = 3.3 × 10−4; −8.5 cm).
Overall, we find that CYBC1 deficiency results in CGD characterized by colitis and a distinct
profile of infections indicative of macrophage dysfunction.We wish to thank the family of the two probands, as well as all the other individuals who
participated in the study and whose contribution made this work possible.Peer Reviewe
Eighty-eight variants highlight the role of T cell regulation and airway remodeling in asthma pathogenesis
Publisher's version (útgefin grein)Asthma is one of the most common chronic diseases affecting both children and adults. We report a genome-wide association meta-analysis of 69,189 cases and 702,199 controls from Iceland and UK biobank. We find 88 asthma risk variants at 56 loci, 19 previously unreported, and evaluate their effect on other asthma and allergic phenotypes. Of special interest are two low frequency variants associated with protection against asthma; a missense variant in TNFRSF8 and 3‘ UTR variant in TGFBR1. Functional studies show that the TNFRSF8 variant reduces TNFRSF8 expression both on cell surface and in soluble form, acting as loss of function. eQTL analysis suggests that the TGFBR1 variant acts through gain of function and together with an intronic variant in a downstream gene, SMAD3, points to defective TGFβR1 signaling as one of the biological perturbations increasing asthma risk. Our results increase the number of asthma variants and implicate genes with known role in T cell regulation, inflammation and airway remodeling in asthma pathogenesis.We thank the individuals who participated in this study and the staff at the Icelandic Patient Recruitment Center and the deCODE genetics core facilities. Further to all our colleagues who contributed to the data collection and phenotypic characterization of clinical samples as well as to the genotyping and analysis of the whole-genome association data. This research has been conducted using the UK biobank Resource under Application Number ‘24711’.Peer Reviewe
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