Biomedical subjects

C Persson

Publications and source records attributed to C Persson.

At least 19 recordsLinked to original sources

PubMed2006

Incidence and remission of self-reported allergic rhinitis symptoms in adults.

BACKGROUND: A few studies have examined the incidence and remission of allergic rhinitis (AR) in the same general population. METHODS: A questionnaire focused on respiratory symptoms and airway diseases was mailed out in 1992 and in 2000 to the same subjects. Of 4933 subjects, in 1992 aged 20-59 years, 4280 (86.8%) answered at both occasions. AR was defined on self-reported AR and a simultaneous report of nasal symptoms provoked by exposure either to tree-, grass-pollen, furred animals or house dust. Multiple logistic regression adjusted for age and gender was used to analyze potential predictors, reported in 1992, for incidence and remission of AR. RESULTS: The prevalence of AR increased from 12.4% in 1992 to 15.0% in 2000. The incidence of AR from 1992 to 2000 was 4.8%, while 23.1% of the cases with AR in 1992 stated no AR symptoms in 2000 indicating remission. The highest incidence was seen in the youngest age group (20-29 years), whereas remission was highest in the oldest age group (50-59 years). Asthma symptoms during the last year (as reported in 1992) predicted increased incidence of AR and less chance for remission, 1.89 (95%CI 1.08-3.31) and 0.52 (0.31-0.87), respectively. Family histories of AR or asthma predicted increased incidence of AR 1.99 (1.42-2.80) and 1.62 (1.10-2.37), respectively, but were not associated with chance for remission, OR = 1.23 (0.81-1.87) and 0.94 (0.60-1.48). CONCLUSION: This study showed that AR became more common between 1992 and 2000, but also indicated remission in about 20% of the cases within the 8-year period, particularly in older ages. Asthma seems to be associated with higher risk for AR as well as less chance for remission, while heredity of asthma (or AR) may only be associated with the risk for the development and not remission of AR.

Adult↗

PubMed2006

High-performance liquid chromatography analysis of rubber allergens in protective gloves used in health care.

A high-performance liquid chromatography (HPLC) method developed for analysis of zinc dithiocarbamates was validated and used to perform a survey of disposable medical gloves used in southern Sweden. The gloves were extracted with acetone at room temperature for 10 min by shaking. The extracts were injected into a polyether ether ketone lined HPLC column, and peaks were analysed by a diode-array detector. The survey shows that of 19 gloves analysed, 10 contained zinc diethyldithiocarbamate (0.070-3.5 mg/g), 3 contained zinc pentamethylenedithiocarbamate (1.0-4.3 mg/g), 4 contained zinc dibutyldithiocarbamate (0.9-1.1 mg/g), and 2 contained 2-mercaptobenzothiazole (0.005-0.008 mg/g). None of them contained thiurams.

Allergens↗

PubMed2006

Radiopacity of tantalum-loaded acrylic bone cement.

Radiopacifying agents are commonly added to bone cements to enhance the visibility of the cement in radiography. The radiopacifiers usually employed may, however, have undesired effects on the mechanical properties of the cement. A potentially new radiopacifier is tantalum, which in the present work was evaluated in terms of radiopacity. Bone cements containing different percentages of tantalum were compared with plain bone cement as well as with formulations containing different percentages of the commonly used radiopacifier barium sulphate. The radiopacity was assessed quantitatively and qualitatively, by measuring with a digital densitometer the optical density of the cement on X-ray films, and consulting the expertise of ten orthopaedic surgeons. It was found that tantalum does present radiopacity, but not as high as barium sulphate under the specific conditions applied to this study.

Absorptiometry, Photon↗

PubMed2005

Extraction of haptens from solid products and their delivery to the skin, exemplified by dithiocarbamates from rubber gloves.

Allergic contact dermatitis is often caused by solid products such as rubber gloves. Patch testing with the product as is often gives negative results. Extraction of the haptens into an organic solvent is commonly performed to achieve a more correct investigation. The technique used for extraction of haptens from solid materials is only sporadically described. In this study, we investigated and optimized the yields of dithiocarbamates obtained by extraction from rubber gloves. The influence of solvent, extraction time and the procedures for extraction are evaluated. The delivery of zinc dibutyldithiocarbamate from the patch test preparation to the skin is determined.

Chromatography, High Pressure Liquid↗

PubMed2004

Can the confidence in long range atmospheric transport models be increased? The pan-european experience of ensemble.

Is atmospheric dispersion forecasting an important asset of the early-phase nuclear emergency response management? Is there a 'perfect atmospheric dispersion model'? Is there a way to make the results of dispersion models more reliable and trustworthy? While seeking to answer these questions the multi-model ensemble dispersion forecast system ENSEMBLE will be presented.

Air Movements↗

PubMed2004

Topical treatment with aqueous solutions of rofleponide palmitate and budesonide in a pollen-season model of allergic rhinitis.

BACKGROUND: Rofleponide palmitate is an esterified glucocorticosteroid pro-drug with a promising pre-clinical profile designed to deliver topical airway treatment for allergic rhinitis and asthma in a novel manner. Thus, the rofleponide palmitate pro-drug is designed to provide topical exposure of the mucosa to the inactive lipophilic drug, which would be locally metabolized to the more hydrophilic and readily cleared drug rofleponide. OBJECTIVE: To examine whether rofleponide palmitate affects nasal symptoms and peak inspiratory flow (PIF) in a pollen-season model of allergic rhinitis and to compare any such effects with those of another glucocorticosteroid (i.e., budesonide). METHODS: During the pollen-free season, 40 patients with strictly seasonal allergic rhinitis received topical nasal spray treatment with an aqueous solution of rofleponide palmitate 400 microg and an aqueous solution of budesonide 128 microg once daily for 10 days in a double-blind, placebo-controlled, and crossover study. After 3 days of drug treatment, individualized allergen challenges were given once daily for 7 days while the treatment continued. The washout periods between each of the challenge series were 2 weeks. Nasal symptoms and PIF were recorded in the morning and evening, as well as 10 and 20 min after each allergen challenge. The mean recordings obtained during the last 3 days of the allergen-challenge series, when symptoms were established and when the treatment had lasted for 8-10 days, were used in the analysis. RESULTS: Both active treatments reduced nasal symptoms and improved nasal PIF compared with placebo (P<0.01-0.001). There was no overall difference in efficacy between rofleponide palmitate 400 microg and budesonide 128 microg. CONCLUSIONS: Topical treatment with aqueous solutions of rofleponide palmitate attenuates nasal symptoms and improves nasal PIF in allergic rhinitis. The overall efficacy of 400 microg of rofleponide palmitate is similar to that of 128 microg of budesonide in the pollen-season model used in this study.

Administration, Intranasal↗

PubMed2001

Correlation induced paramagnetic ground state in FeAl.

Experimentally the intermetallic compound FeAl is known to be nonmagnetic, whereas conventional density functional theory calculations within the local density approximation always yield a ferromagnetic ground state with a magnetic moment at the Fe site of about 0.7 mu(B). We show that a correlation correction within the LDA+U scheme yields a nonmagnetic ground state for U>or=3.7 eV using two different implementations. The disappearance of the magnetic ground state occurs since Fe-t(2g) and Fe-e(g) manifolds are affected differently by a common U. For large values of U a magnetic solution reappears as expected for strong correlation.

Journal Article↗

PubMed2001

Ligand stimulation reduces platelet-derived growth factor beta-receptor susceptibility to tyrosine dephosphorylation.

Ligand binding to the platelet-derived growth factor (PDGF) beta-receptor leads to increased receptor tyrosine phosphorylation as a consequence of dimerization-induced activation of the intrinsic receptor tyrosine kinase activity. In this study we asked whether ligand-stimulated PDGF beta-receptor tyrosine phosphorylation, to some extent, also involved reduced susceptibility to tyrosine dephosphorylation. To investigate this possibility we compared the sensitivity of ligand-stimulated and non-stimulated forms of tyrosine-phosphorylated PDGF beta-receptors to dephosphorylation using various preparations containing protein-tyrosine phosphatase activity. Ligand-stimulated or unstimulated tyrosine-phosphorylated receptors were obtained after incubation of cells with pervanadate only or pervanadate, together with PDGF-BB, respectively. Dephosphorylation of receptors immobilized on wheat germ agglutinin-Sepharose, as well as of receptors in intact cell membranes, was investigated under conditions when rephosphorylation did not occur. As compared with unstimulated receptors the ligand-stimulated PDGF beta-receptors showed about 10-fold reduced sensitivity to dephosphorylation by cell membranes, a recombinant form of the catalytic domain of density-enhanced phosphatase-1, or recombinant protein-tyrosine phosphatase 1B. We conclude that ligand-stimulated forms of the PDGF beta-receptor display a reduced susceptibility to dephosphorylation. Our findings suggest a novel mechanism whereby ligand stimulation of PDGF beta-receptor, and possibly other tyrosine kinase receptors, leads to a net increase in receptor tyrosine phosphorylation.

Agglutinins↗

PubMed2001

Transcription factor AP-4 is a ligand for immunoglobulin-kappa promoter E-box elements.

Immunoglobulin (Ig)-kappa promoters from humans and mice share conserved sequences. The octamer element is common to all Ig promoters and pivotal for their function. However, other conserved sequence motifs, that differ between Ig variable gene families, are required for normal promoter function. These conserved motifs do not stimulate transcription in the absence of an octamer. One example is an E-box of the E47/E12 type (5'-CAGCTG-3'), which is found in all promoters of the human and murine Ig-kappa gene subgroups/families, with the exception of subgroups II and VI and their related murine families. In the present study we show that the ubiquitously expressed transcription factor AP-4, and not E47, interacts specifically with the kappa promoter E-boxes when tested in electrophoretic mobility-shift assays using nuclear extracts derived from human and murine B-cell lines. Furthermore, AP-4, unlike E47, did not act as a transactivator, which is in agreement with previous studies on intact kappa promoters, showing that transcription is absent when the octamer element has been mutated. Based on these data, and the conservation of the 5'-CAGCTG-3' motif among human and murine kappa promoters, we propose that AP-4 is the major ligand for Ig-kappa promoter E-boxes.

Animals↗

PubMed2001

PEBP2 and c-myb sites crucial for lambda5 core enhancer activity in pre-B cells.

The lambda5 gene is expressed exclusively in precursor (pre-) B cells where its gene product, as part of the pre-B cell receptor, is crucial for the proliferation of these cells. Several DNA regions regulate the activity and expression pattern of the lambda5 gene. Amongst these is an enhancer, B(lambda5), located 5' of the gene. Here we analyze the lambda5 enhancer core, b(lambda5), which in earlier experiments was demonstrated to retain 50% of the enhancer activity, and show that this activity is restricted to pre-B cells. We identify a DNA element within b(lambda5), PEBP2(lambda5), which is essential for enhancer activity: mutation within this site dramatically reduces core enhancer activity in pre-B cells. The PEBP2(lambda5) site binds bacterially produced polyoma enhancer binding proteins (PEBP) (Runx/AML/CBFA). Furthermore, PEBP2 proteins present in nuclear extracts from murine pre-B cells bind to the PEBP2(lambda5) element. PEBP2 proteins in mature B cells also bind to the PEBP2(lambda5 )element, implying that if PEBP2 proteins are responsible for the stage-specific expression, they have to be non-activating or inhibiting in mature B cells. We also demonstrate that a described partner of PEBP2, c-myb, binds to a sequence termed myb(lambda5) located just upstream of the PEBP2(lambda5) site in the core enhancer. The myb(lambda5) element is also crucial for enhancer activity, since mutating the myb site reduces core enhancer activity to the same extent as mutating the PEBP2 site. Earlier reports have shown that c-myb is expressed at high levels in pre-B cell lines whereas its expression is down-regulated in more mature B cell lines. Thus, c-myb may be involved in determining the stage-specific expression of the lambda5 gene.

Animals↗

PubMed2001

Reduced utilisation of specialist care among elderly cancer patients: a randomised study of a primary healthcare intervention.

The aim of this study was to evaluate the effect of an individual support (IS) intervention including intensified primary healthcare on the utilisation of specialist care among cancer patients, and to investigate if such an effect was modified by the patient's age (less than 70 years or 70 years and more). Newly diagnosed cancer patients (n=416) were randomised between the intervention and a control condition, and data were collected on the utilisation of specialist care within 3 months from inclusion. Intensified primary healthcare comprised extended information from the specialist clinics, and education and supervision in cancer care for general practitioners (GPs) and home-care nurses. The support given also included interventions designed to diminish problems of weight loss and psychological distress. The intervention reduced the number of admissions (NoA) and the days of hospitalisation (DoH) after adjustment for weight loss and psychological distress, but only for older patients. Older patients randomised to the intervention (n=82) experienced 393 fewer DoH than the older control patients (n=79). In addition, the proportion of older patients in the IS group who utilised acute specialist care was smaller compared with older control patients group. The conclusion is that older cancer patients' utilisation of specialist care may be reduced by intensified primary healthcare services.

Age Factors↗

PubMed2001

Dual symptomatic and exudative nasal responses are not characteristics of perennial allergic rhinitis.

Acute and late phase (dual) symptomatic responses after allergen challenge commonly occur in allergic asthma. The aim of the present study was to explore the occurrence of allergen challenge-induced biphasic responses in patients with chronic perennial allergic rhinitis living in an area with high house dust mite (HDM) exposure. Fifteen patients with perennial rhinitis and evident allergy to HDM participated. Nasal challenges with HDM and sham were performed on separate days in a crossover design. Nasal symptoms, forced expiratory volume in 1 s (FEV1) and orally exhaled nitric oxide were recorded every hour for up to 8 h after each challenge. Alpha2-macroglobulin and eosinophil cationic protein (ECP) were analysed in hourly nasal lavages, and nasal histamine provocations were carried out after 8 h. HDM, but not sham, caused an immediate increase in nasal symptoms which gradually abated over the 8-h period. No reoccurrence of nasal late phase symptoms was seen. HDM, but not sham, induced an early increase in alpha2-macroglobulin and ECP levels: both indices remained elevated for up to 3 h after challenge. HDM challenge evoked hyper-responsiveness to histamine expressed as increased nasal symptoms (p < 0.05; HDM vs sham). No differences in exhaled nitric oxide or FEV1 were demonstrated at any one time point between the HDM- and sham-challenged days. It is concluded that nasal symptomatic and exudative late phase responses may not be a general feature, even in subjects with perennial rhinitis challenged with high, symptom-provoking, doses of HDM allergen.

Adolescent↗

PubMed2001

Long-term experience with citalopram in the treatment of adolescent OCD.

OBJECTIVE: The primary purpose of the study was to describe tolerability and effectiveness of citalopram in the treatment of adolescent obsessive-compulsive disorder (OCD). METHOD: Thirty nondepressed patients (15 females, 15 males) with a mean age of 13.7 years (range 13-18 years) were treated for their OCD with citalopram in an open-label, flexible-dose study (range of dose 20-70 mg; mean dose 46.5 mg). All patients were referred to Aarhus University Hospital. The patients were monitored for 1 to 2 years. The mean total score on the Yale-Brown Obsessive Compulsive Scale (child or adult version) was 28.7 at base-line, 23.3 after 10 weeks of treatment, 20.0 after 6 months, 18.4 after 1 year, and 17.9 after 2 years (from baseline to 2 years of treatment: t = 11.65; p < .001). RESULTS: Seventy percent showed a decrease in total Yale-Brown Obsessive Compulsive Scale score in excess of 35% from baseline to 1 year of treatment. Twenty percent still had a score of greater than 20 after 1 year of treatment, indicating that clinically they still had OCD. Side effects were similar to those reported from the use of other selective serotonin reuptake inhibitors (SSRIs). No patient was excluded because of serious side effects during the 1 year of observation. CONCLUSIONS: The clinical effectiveness and tolerability of citalopram in the long-term treatment seem to be comparable with the observations of other SSRIs in childhood and adolescent OCD. A further, statistically significant reduction is provided by an extended treatment period of up to 1 year.

Adolescent↗

PubMed2000

Site-selective dephosphorylation of the platelet-derived growth factor beta-receptor by the receptor-like protein-tyrosine phosphatase DEP-1.

Ligand stimulation of PDGF beta-receptors leads to autophosphorylation of the regulatory tyrosine 857 and of tyrosine residues that in their phosphorylated form serve as docking sites for Src homology 2 domain-containing proteins. Regulation of the PDGF beta-receptor by protein-tyrosine phosphatases is poorly understood. We have investigated PDGF beta-receptor dephosphorylation by receptor-like protein-tyrosine phosphatase DEP-1 using a cell line with inducible DEP-1 expression and by characterizing in vitro dephosphorylation of the PDGF beta-receptor and of receptor-derived phosphopeptides by DEP-1. After DEP-1 induction PDGF beta-receptor.DEP-1 complexes and reduced receptor tyrosine phosphorylation were observed. Phosphopeptide analysis of the PDGF beta-receptors from DEP-1-expressing cells and of the receptors dephosphorylated in vitro by DEP-1 demonstrated that dephosphorylation of autophosphorylation sites of the receptor differed and revealed that the regulatory Tyr(P)(857) was not a preferred site for DEP-1 dephosphorylation. When dephosphorylation of synthetic receptor-derived peptides was analyzed, the selectivity was reproduced, indicating that amino acid sequence surrounding the phosphorylation sites is the major determinant of selectivity. This notion is supported by the observation that the poorly dephosphorylated Tyr(P)(562) and Tyr(P)(857), in contrast to other analyzed phosphorylation sites, are surrounded by basic amino acid residues at positions -4 and +3 relative to the tyrosine residue. Our study demonstrates that DEP-1 dephosphorylation of the PDGF beta-receptor is site-selective and may lead to modulation, rather than general attenuation, of signaling.

Amino Acid Sequence↗

PubMed2000

Growth of Arthrobotrys superba from a birch wood resource base into soil determined by radioactive tracing.

The ability of a nematode-trapping fungus to establish in field soil is an important characteristic when considering its use as a biological control agent. The outgrowth of the nematode-trapping fungus Arthrobotrys superba from wood was recorded by labelling the fungus with [(14)C]3-O-methylglucose and [(32)P]orthophosphoric acid and by using the soil sprinkling method. The fungus reached a distance of 7-8 cm during 25 days in heat-treated (60 degrees C) soil, detected by either radioactive tracing or the soil sprinkling technique. The two labelled compounds were co-distributed at all sampling times (r(2)=0.946) which indicates that the glucose pool (as methylglucose) and phosphorus content were correlated throughout the mycelium. In natural, non-heat-treated soil the fungus reached a distance of 1.5 cm from one disc of birch wood after 30 days, while it reached 3.2 cm during the same period when the food base was a pile of five inoculated discs. The experiments showed, for the first time, that a nematophagous fungus, A. superba, can grow out into soil from a piece of wood and supported by nutrients translocated from the resource base to the edge of the mycelium.

Journal Article↗

PubMed2000

Dose-dependent effects of budesonide aqueous nasal spray on symptoms in a daily nasal allergen challenge model.

BACKGROUND: It has been difficult to demonstrate dose-dependent clinical effects of anti-allergic glucocorticosteroid drugs in allergic rhinitis. OBJECTIVE: To determine dose-dependent effects on rhinitis symptoms of clinical doses of the glucocorticosteroid budesonide in a standardized daily allergen challenge model. METHODS: Twenty-five patients with seasonal allergic rhinitis were examined outside the pollen season. The highest 256 microg once daily and lowest 64 microg once daily clinically recommended doses of budesonide aqueous nasal spray and placebo were given in a double-blind, placebo-controlled, randomized, and crossover design with 4 weeks' washout between treatments. After 1 week's treatment, the patients received individually titrated nasal allergen challenges once every morning for 8 days while treatment continued. Nasal symptoms were scored in diary cards. Nasal symptoms from the 6th to the 8th challenge days were used in the analysis. RESULTS: The provocation model produced clinically relevant, and around the clock well tolerable rhinitis symptoms, suggesting that after several days of repeated allergen challenges, a season-like, transient allergic disease condition had been established. Both 64 microg and 256 microg of budesonide aqueous nasal spray reduced nasal symptoms. Budesonide 64 microg reduced total nasal symptoms scores from 5.19 +/- 0.5 to 4.23 +/- 0.53 (P < .05), and budesonide 256 microg reduced total nasal symptoms scores to 3.41 +/- 0.51 (P < .001). A significant difference in nasal symptoms after challenge between budesonide aqueous nasal spray 64 microg and 256 microg (P = .03), indicated a dose-dependent effect. CONCLUSIONS: A dose-dependent, symptom-reducing effect of once-daily treatment with topical aqueous nasal sprays of budesonide for two weeks was demonstrated, suggesting that this model is relevant for assessments of dose-dependent effects of anti-inflammatory drugs.

Administration, Intranasal↗

PubMed2000

Antibodies against thrombospondin-related anonymous protein do not inhibit Plasmodium sporozoite infectivity in vivo.

Thrombospondin-related anonymous protein (TRAP), a candidate malaria vaccine antigen, is required for Plasmodium sporozoite gliding motility and cell invasion. For the first time, the ability of antibodies against TRAP to inhibit sporozoite infectivity in vivo is evaluated in detail. TRAP contains an A-domain, a well-characterized adhesive motif found in integrins. We modeled here a three-dimensional structure of the TRAP A-domain of Plasmodium yoelii and located regions surrounding the MIDAS (metal ion-dependent adhesion site), the presumed business end of the domain. Mice were immunized with constructs containing these A-domain regions but were not protected from sporozoite challenge. Furthermore, monoclonal and rabbit polyclonal antibodies against the A-domain, the conserved N terminus, and the repeat region of TRAP had no effect on the gliding motility or sporozoite infectivity to mice. TRAP is located in micronemes, secretory organelles of apicomplexan parasites. Accordingly, the antibodies tested here stained cytoplasmic TRAP brightly by immunofluorescence. However, very little TRAP could be detected on the surface of sporozoites. In contrast, a dramatic relocalization of TRAP onto the parasite surface occurred when sporozoites were treated with calcium ionophore. This likely mimics the release of TRAP from micronemes when a sporozoite contacts its target cell in vivo. Contact with hepatoma cells in culture also appeared to induce the release of TRAP onto the surface of sporozoites. If large amounts of TRAP are released in close proximity to its cellular receptor(s), effective competitive inhibition by antibodies may be difficult to achieve.

Amino Acid Sequence↗

PubMed2000

Phylogeny of the Neotropical Alibertia group (Rubiaceae), with emphasis on the genus Alibertia, inferred from ITS and 5S ribosomal DNA sequences.

Phylogenetic relationships of 38 species of the Alibertia group (Rubiaceae) and two outgroup species were investigated using the nuclear ribosomal 5S nontranscribed spacer (5S-NTS) and the internal transcribed spacers (ITS). Analysis of the data sets separately and in combination resulted in several well-supported and congruent groupings. However, the three analyses yielded different results as to the branching order of the basal clades. With the exception of Alibertia hispida, the species in the genus Alibertia appear in one weakly to moderately supported clade. This clade is in turn composed of two strongly supported subclades. One comprises several Alibertia species, including the type (A. edulis), three Borojoa species, and Randia tessmannii. The other subclade consists of Alibertia species only. This division is also generally supported morphologically by fruit size, corolla size, number of corolla lobes, and pollen aperture (porate vs. colporate). The sister group to the Alibertia clade comprises Duroia with Amaioua species internested. The close relationship of Ibetralia and Kutchubaea is corroborated. In addition, Alibertia hispida is a member of this strongly supported clade. Likewise, the two "Genipa" species are supported as a monophyletic group in 100% of the bootstrap replicates. It is concluded that the 5S spacer is superior to the commonly used ITS region in terms of resolution and robustness among closely related taxa.

Journal Article↗