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M Isaksson

Publications and source records attributed to M Isaksson.

At least 19 recordsLinked to original sources
PubMed2006

Vertical migration studies of 137Cs from nuclear weapons fallout and the Chernobyl accident.

The vertical migration of (137)Cs originating from nuclear weapons fallout (NWF) and the Chernobyl accident has been studied at 33 sampling sites in western Sweden. An attempt to describe the present depth distribution with a solution to the convection-diffusion equation (CDE) with a pulse-like fallout event as the initial condition was made. A sum of two CDEs describing the NWF and Chernobyl debris was fitted to the actual depth profiles measured by soil sampling. The fitted depth profiles were used to correct in situ measurements for the actual depth distribution, showing good agreement with the accumulated activities in soil samples. As expected, the vertical migration was very slow and most caesium was still present in the upper soil layers. The ranges of the apparent convection velocity, v, and apparent diffusion coefficient, D, were between 0 and 0.35 cm/year and 0.06 and 2.63 cm(2)/year, respectively.

Cesium Radioisotopes↗
PubMed2006

SYBR Green real-time reverse transcription-polymerase chain reaction assay for the generic detection of coronaviruses.

Coronaviruses are etiologic agents of respiratory and enteric diseases in humans and in animals. In this study, a one-step real-time reverse transcription-polymerase chain reaction (RT-PCR) assay based on SYBR Green chemistry and degenerate primers was developed for the generic detection of coronaviruses. The primers, designed in the open reading frame 1b, enabled the detection of 32 animal coronaviruses including strains of canine coronavirus, feline coronavirus, transmissible gastroenteritis virus (TGEV), bovine coronavirus (BCoV), murine hepatitis virus (MHV) and infectious bronchitis virus (IBV). A specific amplification was also observed with the human coronaviruses (HCoV) HCoV-NL63, HCoV-OC43, HCoV-229E and severe acute respiratory syndrome coronavirus (SARS-CoV). The real-time RT-PCR detected down to 10 cRNA copies from TGEV, BCoV, SARS-CoV and IBV. In addition, the assay exhibited a high sensitivity and specificity on clinical samples from different animal species. The developed assay represents a potential tool for laboratory diagnostics and for detecting still uncharacterized coronaviruses.

Animals↗
PubMed2006

Contact allergy to textile dyes in southern Sweden.

Contact allergy to disperse dyes in textiles is documented in prevalence studies from southern Europe. To evaluate the prevalence of allergic patch test reactions to different textile dyes in southern Sweden, and to look at the sites of dermatitis in individuals hypersensitive to textile dyes, we retrospectively investigated 3325 consecutively patch-tested patients. They had all been patch tested with the standard test series supplemented with a textile dye mix (TDM) consisting of 8 disperse dyes, i.e. Disperse (D) Blue 35, 106 and 124, D Yellow 3, D Orange 1 and 3 and D Red 1 and 17. All but 3 of the TDM-positive patients were additionally tested with the separate dyes included in the mix. The frequency of contact allergy to TDM was 1.5%, which is comparable with studies from southern Europe. The most common dye allergen was D Orange 1. The high prevalence of allergic reactions to D Orange 1 was unexpected, whereas test reactions to D Blue 106 and 124 were lower than expected from other studies. Compared to all tested patients, the TDM-positive patients more often had dermatitis on their arms, face, neck and axillary folds, and women also had a higher frequency of hand dermatitis.

Adolescent↗
PubMed2006

GABA-site antagonism and pentobarbital actions do not depend on the alpha-subunit type in the recombinant rat GABA receptor.

AIM: The roles of alpha-subunits on the gamma-aminobutyric acid (GABA)-site antagonism and pentobarbital actions were examined in rat recombinant GABA(A) receptors in Xenopus oocytes. METHODS: Experiments were performed with binary and ternary GABA(A) receptors containing alpha1-, alpha4- or alpha5-subunit by the two-electrode voltage-clamp technique. RESULTS: The potency of GABA was significantly higher in the alpha1beta2, alpha4beta2 and alpha5beta2 receptors compared with the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. However, the alpha5beta2 receptor possessed significantly lower GABA efficacy compared with the alpha5beta2gamma2L receptor. While the gamma2-subunit was essential to the potency of GABA, its influence on the apparent GABA-site antagonism was less profound. The antagonist affinity constants (K(B)) of bicuculline inhibition and slopes of Schild plots were similar between all types of ternary and binary receptors except alpha5beta2 receptor which was not tested. The pK(B)s and IC(50)s of the GABA-site antagonism were not significantly different between the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. Bicuculline blocked pentobarbital-activated currents in a reversible and non-competitive manner with the alpha1beta2gamma2L, alpha4beta2gamma2L, and alpha5beta2gamma2L receptors, indicating an allosteric inhibition of the GABA-site. No significant difference of bicuculline potencies in inhibiting GABA- and pentobarbital-activated currents was found between the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. CONCLUSION: The GABA-site antagonism does not depend on the subtype of alpha-subunits. Similarly, pentobarbital activates ternary receptors composed of different alpha-subunits in a bicuculline-sensitive manner. The potencies of bicuculline to inhibit pentobarbital-activated currents are identical with receptors containing alpha1, alpha4 or alpha5-subunit. The alpha1beta2 and alpha4beta2 receptors possess higher GABA potencies compared with the alpha1beta2gamma2L and alpha4beta2gamma2L receptors.

Animals↗
PubMed2005

Risk of contact allergy and dermatitis at a wind turbine plant using epoxy resin-based plastics.

AIMS: To identify workplace and individual risk factors for occupational contact allergy and dermatitis. METHODS: A cross-sectional study was carried out at an international company producing wind turbine systems in Denmark. A cohort of 724 production workers at four facilities was highly exposed to epoxy resin as well as other chemicals. A screening questionnaire (participation rate 84.7%) was followed by an interview by an occupational physician and a dermatological examination, including patch testing, for a comprehensive list of potential workplace sensitizers. RESULTS: Clinically diagnosed dermatitis was found among 214 workers (35.8%) and contact allergy to materials used in the workplace was found in 66 workers (10.9% of the total population and 20.3% of those who underwent patch testing). Of the 66 workers with a work-related allergy, 40 (60.6%) were allergic to epoxy compounds, 25 (37.9%) to hardeners and ten (15.2%) to other workplace materials, where one person showed an allergy only to these materials. Experiencing contact allergy was related to older age and longer employment in the workplace-however, neither of these risk factors was significant. The main risk factor for current dermatitis was contact allergy to materials used in the workplace, determined by patch testing, OR=5.4 (95% CI 3.9-9.9). Fewer days of absence from work was also related to current dermatitis, OR=2.0 (95% CI 1.2-3.5). CONCLUSIONS: In a cohort of workers with extensive exposure to chemicals related to epoxy-resin systems, contact dermatitis and allergy was prevalent. Older age and longer duration of employment at the workplace were individual risk factors for allergy to workplace materials, whilst work-related allergies and longer duration of employment at the workplace were significant risk factors for current dermatitis.

Adolescent↗
PubMed2004

Persistent itching nodules after the fourth dose of diphtheria-tetanus toxoid vaccines without evidence of delayed hypersensitivity to aluminium.

Studies in Gothenburg, Sweden, reported an exceptionally high rate of persistent itching nodules at the site of injection of aluminium containing vaccines, usually with positive epicutaneous tests to aluminium. When a new booster diphtheria-tetanus vaccine was introduced we performed a prospective cluster randomised active surveillance in 25,232 10-year-olds. Parental reports 6 months after vaccination with Duplex or diTeBooster were collected for 22,365 (88%) pupils in 851 schools. We identified 3-6 children per 10,000 with a local itching nodule persisting for at least 2 months. There were no significant differences between the vaccine groups. Contact allergy to aluminium was not detected. The findings support the use of the vaccine presently available in the Swedish vaccination program. Continued surveillance of persistent itching nodules and aluminium contact allergy is, however, warranted for vaccines containing pertussis toxoid and aluminium.

Adjuvants, Immunologic↗
PubMed2004

Epoxy-based production of wind turbine rotor blades: occupational dermatoses.

Occupational dermatoses were investigated in a factory producing rotor blades for wind turbines by an epoxy-based process. In a blinded study design, 603 workers were first interviewed and thereafter clinically examined. Based on a history of work-related skin disease, clinical findings of dermatitis, or both, 325 (53.9%) of the workers were patch tested with a specially profiled occupational patch-test series and the European standard patch-test series. Calculated on all investigated workers, 17.1% of the workers were diagnosed with occupational dermatoses caused by work. Occupational allergic contact dermatitis was found in 10.9% of the workers. The estimated frequency of irritant contact dermatitis caused by work was 6.1%. Dermatitis on the hands was associated with contact allergy to epoxy resin (P = 0.017). The number of days on leave before the clinical examination was negatively associated with the presence of dermatitis (P = 0.001). Among workers employed 7-12 months, the frequency of occupational contact allergy was higher than that among workers employed for </=6 months (P = 0.004). Females both washed their hands more often (P < 0.001) and used more moisturizers/protection creams at work (P < 0.001) than males. No sex differences were found concerning dermatitis on the hands.

Adolescent↗
PubMed2004

Retained heterodisomy for chromosome 12 in atypical lipomatous tumors: implications for ring chromosome formation.

Atypical lipomatous tumor (ALT) is an intermediate malignant mesenchymal tumor that is characterized by supernumerary ring chromosomes and/or giant rod-shaped marker chromosomes (RGMC). Fluorescence in situ hybridization (FISH) and molecular genetic analyses have disclosed that the RGMCs always contain amplified sequences from the long arm of chromosome 12. Typically, RGMCs are the sole clonal changes and so far no deletions or other morphologic aberrations of the two normal-appearing chromosomes 12 that invariably are present have been detected. The mechanisms behind the formation of the RGMCs are unknown, but it could be hypothesized that RGMC formation is preceded by trisomy 12 or, alternatively, that ring formation of one chromosome 12 is followed by duplication of the remaining homolog. The latter scenario would always result in isodisomy for the two normal-appearing chromosomes 12, whereas the former would yield isodisomy in one-third of the cases. In order to investigate these possible mechanisms behind ring formation, we studied polymorphic loci on chromosome 12 in 14 cases of ALT showing one or more supernumerary ring chromosomes and few or no other clonal aberrations at cytogenetic analysis. The molecular genetic analyses showed that the tumor cells always retained both parental copies of chromosome 12, thus refuting the trisomy 12 and duplication hypotheses.

Adult↗
PubMed2003

X-ray fluorescence analysis in medical sciences: a review.

Some elements have toxic effects on the human body and there is thus a need to control their levels in human organs and tissues. Moreover, it is important to increase our knowledge of relationships between observable toxic effects and element concentrations in man and his environment. Monitoring and basic occupational and environmental research rely on measurements directly in humans as well as samples from humans and the environment. This paper reviews recent advances in in vivo X-ray fluorescence methods and their applications.

Disease↗
PubMed2003

Determination of potassium in the skeletal muscles by whole-body counting.

Changes in muscular function are related to nutritional status, disease and physical activity. To study these relationships, it is desirable to be able to determine the whole body potassium content, which is characteristic to the muscular tissue. This can be achieved by measurements in a whole-body counter, identifying contributions from the upper and lower parts of the body. In a whole-body counter with large plastic scintillators, a special measuring methodology is required. Such a method of measuring (40)K in the leg muscles, extracting the part of the detector signal originating from the lower part of the body, has been developed and tested by independent phantom measurements. The results suggest that it is suited to perform regional measurements of body potassium but validation and implementation into clinical research are still necessary.

Humans↗
PubMed2003

Hydrothermal treatment and malting of barley improved zinc absorption but not calcium absorption in humans.

OBJECTIVE: To study whether hydrothermal treatment or malting of barley (cv. Blenheim) improves zinc and calcium absorption in humans. DESIGN: : Two groups of 10 and 12 healthy subjects, respectively, were in a period of 2 months in a fasting state, served two single meals each containing porridge or breakfast cereals prepared from processed or unprocessed (control) barley (60 g). The meals included 200 g of milk, extrinsically labelled with (65)Zn and (47)Ca. Whole-body retention of both minerals was measured. SETTING: The study was carried out at the Department of Radiation Physics, Sahlgrenska University Hospital, Göteborg. SUBJECTS: The subjects were recruited among students at the Göteborg University. None dropped out. INTERVENTIONS: The activities of (65)Zn and (47)Ca were measured by whole-body counting four to five times over a 4-week period after each meal. RESULTS: Zinc absorption from hydrothermally treated barley porridge, containing 28 mg P as inositol tri- to hexaphosphates (InsP(3)-InsP(6)), was significantly higher (P<0.001) than from control porridge containing 111 mg P as InsP(3)-InsP(6), 25.2+/-6.9 vs 11.0+/-2.5% (n=12). Calcium absorption did not differ (P>0.05), 21.1+/-6.8 vs 19.5+/-4.7% (n=12). Zinc absorption from breakfast cereals of malted barley with phytase activity and containing 70 mg P as InsP(3)-InsP(6,) was significantly higher (P<0.05) than from flakes of barley, containing 108 mg P as InsP(3)- InsP(6) and no phytase activity, 22.9+/-5.8 vs 14.8+/-4.6% (n=10). The calcium absorption was 21.3+/-6.5 vs 18.5+/-4.3% (n=10) and did not differ significantly (P>0.05). CONCLUSION: Improvements of zinc absorption in breakfast meals can be achieved by optimised hydrothermal treatment or malting of barley. Calcium absorption was not influenced in the meals in this study. SPONSORSHIP: Supported by Semper AB, Sweden, Oy Lahden Polttimo, Finland, the SL-Foundation, Sweden, Swedish National Board for Industrial and Technical Development (NUTEK), the Nordic Industrial Foundation, Swedish Council for Forestry and Agricultural Research (SJFR, project no 50.0306/97).

Adolescent↗
PubMed2003

Effects of sex steroids on survival and receptor expression in ovarian epithelial tumour cells.

The factors that govern the genesis and progression of ovarian cancer remain unclear. It is thought that ovarian tumours are endocrine related and hormone dependent. We therefore investigated the effects of the sex steroids progesterone, testosterone and 17 beta-estradiol on tumour cell survival and the expression of estrogen receptors (ER) and progesterone receptors (PR) in tumour cells. The study was performed on primary cell cultures derived from patients suffering from epithelial ovarian cancer. The majority of the cells isolated expressed ER and PR to some degree, the combination ER+/PR+ was the most common. Both ER and PR expression decreased after 72-h culture, revealing an unexpectedly dynamic system. The survival rates of cells cultured in progesterone seemed to be inversely related to their PR expression. Lowering levels of 17 beta-estradiol and testosterone in cell cultures reduced cell survival, but it appears that this observation depends on factors other than ER.

Adult↗