| 1. |
- Andersson, Niklas, 1970, et al.
(författare)
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Drug-induced prevention of gastrectomy- and ovariectomy-induced osteopaenia in the young female rat.
- 2002
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Ingår i: The Journal of endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 175:3, s. 695-703
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Tidskriftsartikel (refereegranskat)abstract
- Both ovariectomy (Ovx) and gastrectomy (Gx) induce osteopaenia in rats and humans. While the effect of Ovx has been ascribed to oestrogen deficiency, the underlying mechanism behind Gx is poorly understood. Alendronate, oestrogen and parathyroid hormone (PTH) are known to prevent the osteopaenia induced by Ovx in rats. The purpose of the present study was to determine whether alendronate, oestrogen or PTH could also prevent Gx-evoked osteopaenia. Rats were Ovx-, Gx-, or were sham-operated (Sham) and were then treated with alendronate (50 micro g/kg/day), oestrogen (10 micro g/kg/day) or PTH(1-84) (75 micro g/kg/day) for eight weeks. At sacrifice, serum PTH was unaffected by surgery (Ovx, 64+/-8 pg/ml; Gx, 75+/-13 pg/ml; Sham, 58+/-11 pg/ml). The bone mineral density (BMD) of the fifth lumbar vertebra (L5) was analysed. Ovx and Gx reduced the BMD (ash weight/Volume) of the L5 by 15+/-4% and 22+/-3% respectively. Trabecular BMD and the cortical bone mineral content (BMC) of the femur were assessed using peripheral computed tomography. Both Ovx and Gx markedly reduced trabecular BMD in the metaphyseal area of the distal femur (Ovx, -37+/-7%; Gx, -49+/-7%). The cortical BMC of the femur was only slightly reduced. Alendronate prevented trabecular bone loss after both Ovx and Gx, while oestrogen and PTH prevented trabecular bone loss after Ovx but not after Gx. In conclusion, the bisphosphonate alendronate prevented both Ovx- and Gx-induced trabecular bone loss. In contrast, PTH and oestrogen prevented Ovx-induced but not Gx-induced trabecular bone loss, suggesting that the mechanism behind the trabecular bone loss in Ovx rats differs from that in Gx rats. The results support the notion that the mechanism of action for the bone-sparing effect of these drugs differs. The ability of alendronate, and probably also other bisphosphonates, to prevent Gx-evoked osteopaenia in the rat might be of potential clinical interest when dealing with post-Gx osteopaenia in humans.
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| 2. |
- Andersson, Niklas, 1970, et al.
(författare)
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Pharmacological treatment of osteopenia induced by gastrectomy or ovariectomy in young female rats.
- 2004
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Ingår i: Acta orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470 .- 1651-1964. ; 75:2, s. 201-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Both gastrectomy (GX) and ovariectomy (OVX) induce osteopenia in man and experimental animals. The present study addresses the question--can alendronate, estrogen or parathyroid hormone (PTH) be used to treat established GX- or OVX -evoked osteopenia? METHODS: Rats were GX-, OVX- or SHAM-operated 8 weeks before starting the treatment with drugs. Each group was then treated for 8 weeks with 50 microg/kg/day alendronate, 10 microg/kg/day estrogen or 75 microg/kg/day PTH(1-84); n = 8 rats/group. Peripheral Quantitative Computed Tomography (pQCT) was used to measure trabecular bone mineral density (BMD) and various cortical bone parameters. RESULTS: At killing, 16 weeks after surgery, GX and OVX rats had a greatly reduced trabecular BMD in the metaphysis of the distal femur (GX -44% and OVX -55%). Alendronate increased the trabecular BMD by 44% in GX rats and by 64% in OVX rats, while PTH increased it by 51% and 115%, respectively. However, estrogen increased the trabecular BMD in GX rats (35%), but not in OVX rats (15%, not significant). Cortical bone parameters were adversely (but moderately) affected by GX, but not by OVX or by treatment with the three drugs. INTERPRETATION: Alendronate, estrogen and PTH restored the trabecular bone loss in rats with an established GX-evoked osteopenia. In contrast, alendronate and PTH, but not estrogen, restored the trabecular bone loss after OVX. Hence, the mechanism underlying GX-evoked bone loss differs from that underlying OVX-evoked bone loss. The ability of alendronate, estrogen and PTH to reverse the GX-evoked osteopenia in the rat may be of clinical interest when dealing with bone loss in humans after GX.
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| 3. |
- Andersson, Niklas, 1970, et al.
(författare)
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Repeated in vivo determinations of bone mineral density during parathyroid hormone treatment in ovariectomized mice.
- 2001
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Ingår i: The Journal of endocrinology. - 0022-0795 .- 1479-6805. ; 170:3, s. 529-37
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Tidskriftsartikel (refereegranskat)abstract
- The recent development of different genetically modified mice with potentially interesting bone phenotypes has increased the demand for effective non-invasive methods to evaluate effects on bone of mice during growth and development, and for drug evaluation. In the present study, the skeleton was analyzed by repeated in vivo scans using dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Ovariectomized (ovx) mice treated with parathyroid hormone (PTH) were used as an animal model to evaluate these two techniques at different times after the onset of treatment. Female mice (6 weeks of age) were allocated randomly to four groups: (1) sham-operated+vehicle; (2) ovx+vehicle; (3) sham-operated+PTH(1-84) 150 microg/kg per day; (4) ovx+PTH. Six weeks after ovariectomy the drug treatment began and was continued for 8 weeks. The total body bone mineral content (BMC) and total body areal bone mineral density (BMD) were measured by DXA. Ovariectomy reduced total body BMC and total body areal BMD by 6.2+/-1.7% and 2.6+/-0.9% respectively. No effect of PTH on total body BMC was seen during the treatment period. The trabecular volumetric BMD was measured by pQCT. Ovariectomy reduced the trabecular volumetric BMD by 52+/-6.7%. The pQCT technique detected a clear effect on trabecular volumetric BMD after 2 weeks of PTH treatment (ovx 94+/-29% and sham-operated 46+/-10% more than vehicle-treated). The cortical bone was measured in a mid-diaphyseal pQCT scan of the tibia. Ovariectomy reduced the cortical BMC by 9+/-2%. PTH treatment for 8 weeks increased cortical BMC in ovx mice. In conclusion, the pQCT technique is more sensitive than the DXA technique in the detection of bone loss after ovariectomy and increased bone mass after PTH treatment in mice. Notably, the pQCT, but not the DXA, technique detected a dramatic effect as early as after 2 weeks of PTH treatment. Dynamic pQCT measurements will be useful for monitoring skeletal changes during growth and development, and for drug evaluation in mice.
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| 7. |
- Morgardt-Ryberg, Kristina, et al.
(författare)
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Is contact allergy to disperse dyes and related substances associated with textile dermatitis?
- 2009
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 1365-2133 .- 0007-0963. ; 160, s. 107-115
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Tidskriftsartikel (refereegranskat)abstract
- Summary Background Disperse dyes (DDs) are the most common sensitizers among textile dyes, but there is little knowledge of the clinical relevance of positive patch test reactions. Objective To investigate if patient-reported textile-related skin problems can be explained by contact allergy to eight different DDs and/or to chemically related substances, by occupation or by atopic constitution, and if the skin problems are influenced by age or sex. Methods A questionnaire on textile-related skin problems was answered by 858 of 982 consecutively patch tested patients in Malmö, Sweden and in Leuven, Belgium. The baseline series used for patch testing was supplemented with a textile dye mix (TDM) consisting of the eight DDs and with the separate dyes. The association between textile-related skin problems and contact allergy to the DDs and other risk factors was investigated using multiple logistic regression analysis. Results Eighteen per cent of the patients suspected textiles as a cause of their skin problems. Atopic constitution and female sex were risk factors for skin reactions. Synthetic materials were the most common textiles to give skin problems. A significant association was found between self-reported textile-related skin problems and contact allergy to para-phenylenediamine (PPD) [adjusted odds ratio (OR) 2.1; 95% confidence interval (CI) 1.0-4.3]. A similar, but more imprecise, adjusted OR was found for TDM (OR 1.9; 95% CI 0.57-5.6). Contact allergy to black rubber mix was too rare to be evaluated. Conclusions Contact allergy to PPD was a more prevalent indicator for skin reactions to textiles than the TDM used in this study.
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| 8. |
- Morgardt-Ryberg, Kristina, et al.
(författare)
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Patch testing with a textile dye mix and its constituents in a baseline series.
- 2010
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Ingår i: Dermatitis. - : Mary Ann Liebert Inc. - 1710-3568. ; 21:1, s. 49-56
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Among the textile dyes, disperse dyes are common sensitizers. OBJECTIVE: To investigate whether patch testing with a textile dye mix consisting of eight disperse dyes would be equivalent to testing with the separate ingredients of the mix at the concentrations used in the mix. METHODS: Researchers tested 1,780 consecutive patients with a mix consisting of Disperse Blue 35, Disperse Yellow 3, Disperse Orange 1, Disperse Orange 31 (mislabeled as Disperse Orange 3), Disperse Red 1 and 17, all at 0.5%, and Disperse Blue 106 and 124, both at 0.1%, and with the ingredients at these concentrations. Testing with the labeled dyes at 1.0% was done on 500 of the patients and additionally on the remaining patients who reacted positively to the mix, any of the ingredients, p-phenylenediamine, or black rubber mix. RESULTS: Thirty-five patients (2%) reacted to the mix, and 34 patients were allergic to at least one ingredient tested at the lower concentration. CONCLUSION: The textile dye mix was as good a detector of contact allergy to the disperse dyes as was testing with any combination of the ingredients at the concentration in the mix. Increasing the concentration of the ingredients of the textile dye mix might increase the sensitivity of the mix.
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| 9. |
- Morgardt-Ryberg, Kristina, et al.
(författare)
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Patch Testing with a Textile Dye Mix in a Baseline Series in Two Countries
- 2011
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 91:4, s. 422-427
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Tidskriftsartikel (refereegranskat)abstract
- Disperse dyes are the most common contact sensitizers among textile dyes. The main aim of this study was to investigate the outcome of patch testing with a textile dye mix 6.6%. A total of 2,049 patients from Sweden and 497 from Belgium were tested with the mix, consisting of Disperse (D) Blue 35, D Yellow 3, D Orange 1 and 3, D Red 1 and 17, 1.0% each, and D Blue 106 and D Blue 124, 0.3% each. Of the total number, 65 patients, 2.6%, tested positively to the mix, 4.2% of the Belgian patients and 2.1% of the Swedish patients. Patch testing with the mix 6.6% revealed significantly more patients with contact allergy compared with testing with a previous mix 3.2% (p<0.01). Contact allergy to the mix was significantly more common in the Belgian than in the Swedish patients.
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| 10. |
- Nyström, Birgitta, et al.
(författare)
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Bemanningsanställd och rättslös - eller?
- 2014
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Ingår i: Festskrift till Catharina Calleman : i rättens utkanter - i rättens utkanter. - 9789176788899
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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