1. |
- Bentham, J, et al.
(författare)
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A double-staining technique for detection of growth hormone and insulin-like growth factor-I binding to rat tibial epiphyseal chondrocytes.
- 1993
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 137:3, s. 361-7
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Tidskriftsartikel (refereegranskat)abstract
- In the present study a double-staining technique was developed to investigate simultaneous GH and insulin-like growth factor-I (IGF-I) binding to chondrocytes in a monolayer cell culture. Rat tibial epiphyseal chondrocytes were isolated by enzymatic digestion and cultured in monolayer. GH and IGF-I were labelled with biotin. The affinity of the biotin-labelled ligands was compared with unlabelled ligands in a radioreceptor assay. To study the distribution of GH and IGF-I binding in the monolayer, chondrocytes were incubated with biotinylated ligands with or without an excess of unlabelled ligands, followed by incubation with Vectastain ABC complex, which was then reacted with diaminobenzidine (DAB). Double staining was accomplished by carrying out the first reaction with DAB in the presence of nickel ammonium sulphate to give a black precipitate, followed by incubation with the second ligand, then ABC complex and finally DAB in the absence of nickel ammonium sulphate to give a brown stain. The presence of type-II collagen was demonstrated by immunohistochemistry and used as a marker for differentiated chondrocytes. Biotin-labelled GH and biotin-labelled IGF-I exhibited dose-dependent displacements of 125I-labelled GH and 125I-labelled IGF-I respectively from the chondrocytes in a radioreceptor assay. The displacement curves were identical to those of unlabelled ligands indicating that the affinity was unaltered. Binding of biotinylated GH to cells was seen throughout the culture in regions where there was little or no type-II collagen staining. IGF-I binding was predominantly localized to cells at high density; areas which also showed a high degree of staining for type-II collagen.(ABSTRACT TRUNCATED AT 250 WORDS)
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2. |
- Brittberg, Mats, 1953, et al.
(författare)
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Autolog broskcellstransplantation. Smärtlindring och återställd ledfunktion är målet : Autologous cartilage cell transplantation. The goal is pain relief and restored joint function
- 1995
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Ingår i: Nordisk medicin. - 0029-1420. ; 110:12, s. 330-4
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Tidskriftsartikel (refereegranskat)abstract
- Chondral and osteochondral damage is a common result of trauma to the joints. The capacity of cartilage to heal such damage is poor, and repetitive wear on joint surfaces that do not heal results in impaired joint function, which can culminate in full blown arthrosis. Thus, it is important to improve our knowledge of cartilage regenerative potential, and develop methods to forestall progression to arthrosis by promoting the early healing of cartilage damage. Autologous cartilage cell transplantation may be a mean of healing cartilage damage. A method of cultivating autologous chondrocytes for transplantation in the treatment of isolated damage to articular cartilage of the knee is presented in the article.
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3. |
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4. |
- Brittberg, Mats, 1953, et al.
(författare)
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Cellular aspects on treatment of cartilage injuries.
- 1993
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Ingår i: Agents and actions. Supplements. - 0379-0363. ; 39, s. 237-41
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Tidskriftsartikel (refereegranskat)abstract
- Cellular aspects on articular cartilage growth and development are discussed. Cells with chondrogenic potential are described and current treatment models for cartilage injuries are considered. A rabbit model for treatment of articular cartilage defects with autologous cultured and transplanted chondrocytes for treatment of knee cartilage defects in humans are discussed.
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5. |
- Brittberg, Mats, 1953, et al.
(författare)
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Rabbit articular cartilage defects treated with autologous cultured chondrocytes.
- 1996
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Ingår i: Clinical orthopaedics and related research. - 0009-921X. ; :326, s. 270-83
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Tidskriftsartikel (refereegranskat)abstract
- Adult New Zealand rabbits were used to transplant autologously harvested and in vitro cultured chondrocytes into patellar chondral lesions that had been made previously and were 3 mm in diameter, extending down to the calcified zone. Healing of the defects was assessed by gross examination, light microscope, and histological-histochemical scoring at 8, 12, and 52 weeks. Chondrocyte transplantation significantly increased the amount of newly formed repair tissue compared to the found in control knees in which the lesion was solely covered by a periosteal flap. In another experiment, carbon fiber pads seeded with chondrocytes were used as scaffolds, and repair significantly increased at both 12 and 52 weeks compared to knees in which scaffolds without chondrocytes were implanted. The histologic quality scores of the repair tissue were significantly better in all knees in which defects were treated with chondrocytes compared to knees treated with periosteum alone and better at 52 weeks compared to knees in which defects were treated with carbon scaffolds seeded with chondrocytes. The repair tissue, however, tended to incomplete the bonding to adjacent cartilage. This study shows that isolated autologous articular chondrocytes that have been expanded for 2 weeks in vitro can stimulate the healing phase of chondral lesions. A gradual maturation of the hyalinelike repair with a more pronounced columnarization was noted as late as 1 year after surgery.
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6. |
- Brittberg, Mats, 1953, et al.
(författare)
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Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation.
- 1994
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Ingår i: The New England journal of medicine. - 0028-4793. ; 331:14, s. 889-95
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Full-thickness defects of articular cartilage in the knee have a poor capacity for repair. They may progress to osteoarthritis and require total knee replacement. We performed autologous chondrocyte transplantation in 23 people with deep cartilage defects in the knee. METHODS. The patients ranged in age from 14 to 48 years and had full-thickness cartilage defects that ranged in size from 1.6 to 6.5 cm2. Healthy chondrocytes obtained from an uninvolved area of the injured knee during arthroscopy were isolated and cultured in the laboratory for 14 to 21 days. The cultured chondrocytes were then injected into the area of the defect. The defect was covered with a sutured periosteal flap taken from the proximal medial tibia. Evaluation included clinical examination according to explicit criteria and arthroscopic examination with a biopsy of the transplantation site. RESULTS. Patients were followed for 16 to 66 months (mean, 39). Initially, the transplants eliminated knee locking and reduced pain and swelling in all patients. After three months, arthroscopy showed that the transplants were level with the surrounding tissue and spongy when probed, with visible borders. A second arthroscopic examination showed that in many instances the transplants had the same macroscopic appearance as they had earlier but were firmer when probed and similar in appearance to the surrounding cartilage. Two years after transplantation, 14 of the 16 patients with femoral condylar transplants had good-to-excellent results. Two patients required a second operation because of severe central wear in the transplants, with locking and pain. A mean of 36 months after transplantation, the results were excellent or good in two of the seven patients with patellar transplants, fair in three, and poor in two; two patients required a second operation because of severe chondromalacia. Biopsies showed that 11 of the 15 femoral transplants and 1 of the 7 patellar transplants had the appearance of hyaline cartilage. CONCLUSION. Cultured autologous chondrocytes can be used to repair deep cartilage defects in the femorotibial articular surface of the knee joint.
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7. |
- Isaksson, Olle, 1943, et al.
(författare)
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Regulation of cartilage growth by growth hormone and insulin-like growth factor I.
- 1991
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Ingår i: Pediatric nephrology (Berlin, Germany). - 0931-041X. ; 5:4, s. 451-3
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Tidskriftsartikel (refereegranskat)abstract
- A number of studies have shown that growth hormone (GH) and insulin-like growth factor-I (IGF-I) have important regulatory roles for skeletal growth. However, it has been a matter of controversy whether GH acts directly on cells in the growth plate or if the growth-promoting effects of GH are mediated by liver-derived (endocrine-acting) IGF-I. With the recognition that GH regulates the production of IGF-I in multiple extra-hepatic tissues, autocrine and paracrine functions of IGF-I have been suggested as important components of GH action. This review focuses on recent developments in our understanding of the cellular mechanisms by which GH promotes longitudinal bone growth and the inter-relationship between GH and IGF-I in the growth plate.
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8. |
- Locke, Adam E, et al.
(författare)
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Genetic studies of body mass index yield new insights for obesity biology.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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9. |
- Nilsson, Anders, 1958, et al.
(författare)
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Hormonal regulation of longitudinal bone growth.
- 1994
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Ingår i: European journal of clinical nutrition. - 0954-3007. ; 48 Suppl 1
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Tidskriftsartikel (refereegranskat)abstract
- The regulation of postnatal somatic growth is complex. Genetic, nutritional factors and hormones exert regulatory functions. Hormones that have an established role in the regulation include growth hormone (GH), thyroid hormone and sex steroids. GH promotes mainly the growth of the long bones in terms of final height, while the action of the sex steroids and thyroid hormone is less well known. Longitudinal bone growth is the result of chondrocyte proliferation and subsequent endochondral ossification in the epiphyseal growth-plates. The growth-plate is a cartilaginous template that is located between the epiphysis and the metaphysis of the long bones. GH and insulin-like growth factor-I (IGF-I) have different target cells in the epiphyseal growth-plate. GH stimulates the slowly dividing prechondrocytes in the germinative cell layer while IGF-I promotes the clonal expansion in the proliferative cell layer of a GH primed cell. Thyroid hormone blocks the clonal expansion and stimulates chondrocyte maturation. IGF-I mRNA is primarily regulated by GH, and IGF-I is produced in several tissues such as the liver, muscle, fat and epiphyseal growth plates. However, IGF-I mRNA is also increased during compensatory growth of heart and kidneys and by estrogen in the Fallopian tube in the rat. Nutrition, i.e. energy from fat and carbohydrates and proteins, also influences the final height, but the cellular mechanism of action is not known. The aim of this article is to review hormonal action on longitudinal bone growth.
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10. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Effect of growth hormone and insulin-like growth factor-I on DNA synthesis and matrix production in rat epiphyseal chondrocytes in monolayer culture.
- 1992
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 133:2, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- The influence of various culture conditions was studied on the effect of GH and insulin-like growth factor-I (IGF-I) on DNA and matrix synthesis in epiphyseal rat chondrocytes in monolayer culture. Chondrocytes from enzymatically digested rat tibia epiphyseal growth plates were seeded in 48-well culture plates and precultured for 10 days in Ham's F-12 medium supplemented with 1% (v/v) newborn calf serum and 1% (v/v) of a serum substitute. After preculture, the medium was changed to Ham's F-12 medium supplemented with 1% serum from hypophysectomized rats, and the effect of GH and IGF-I on DNA synthesis ([3H]thymidine incorporation) and matrix production ([35S]sulphate uptake) was studied during an additional 96-h culture period. Isotopes were present during the last 24 h of culture. Both hGH and IGF-I stimulated DNA synthesis in a dose-dependent manner. A maximal effect of GH was seen at a concentration of 25 micrograms/l (60 +/- 11% stimulation over control) and for IGF-I at 10 micrograms/l (162 +/- 12%). The stimulatory effects of the same concentrations of human GH (hGH) and IGF-I on [35S]sulphate uptake were 135 +/- 25 and 320 +/- 42% respectively. In-vitro pulse labelling revealed that GH did not produce a response during the first 3 days of culture (after addition of GH) but was effective during days 4 and 5 of culture. In contrast, IGF-I was effective throughout the culture period. Pretreatment of cells with GH or IGF-I for 2.5 days showed that GH but not IGF-I produced a sustained effect on [3H]thymidine uptake. In order to study the influence of cell density on the effect of GH and IGF-I on DNA synthesis, the effect of added peptides was evaluated after different preculture periods (5-15 days). A maximal stimulatory effect of hGH was seen at a cell density of 150,000-300,000 cells/cm2. GH had no significant effect at a low (less than 100,000 cells/cm2) or a high (greater than 400,000 cells/cm2) cell density. The magnitude of the stimulatory effect of IGF-I was the same at densities between 10,000 and 250,000 cells/cm2, but was reduced at higher cell densities (over 250,000 cells/cm2). Chondrogenic properties of cells that had been cultured for 15 days were verified in vitro by positive alcian blue staining and identification of type II collagen, and in vivo by development of cartilage nodules in nude mice.(ABSTRACT TRUNCATED AT 400 WORDS)
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11. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Effects of tri-iodothyronine and insulin-like growth factor-I (IGF-I) on alkaline phosphatase activity, [3H]thymidine incorporation and IGF-I receptor mRNA in cultured rat epiphyseal chondrocytes.
- 1992
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 135:1, s. 115-23
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Tidskriftsartikel (refereegranskat)abstract
- The effects of tri-iodothyronine (T3) and insulin-like growth factor-I (IGF-I) on [3H]thymidine incorporation, alkaline phosphatase (ALP) activity and IGF-I receptor mRNA levels were studied in rat epiphyseal chondrocytes cultured in monolayer. Chondrocytes from enzymatically digested rat tibia epiphyseal growth plates were seeded in monolayer culture and precultured for 7-14 days in Ham's F-12 medium supplemented with 10% (v/v) newborn calf serum and 1% (v/v) of a serum substitute. After preculture the medium was changed to Ham's F-12 medium containing 1% (v/v) serum from hypophysectomized rats, and the effects of T3 and/or IGF-I on DNA synthesis ([3H]thymidine incorporation), ALP activity (a late marker of differentiated epiphyseal chondrocytes) and IGF-I receptor mRNA levels were studied. ALP activity was increased by T3 in a dose-dependent manner with a maximal response at 10 micrograms T3/l (678 +/- 86% compared with control culture). The increase in ALP activity was accompanied by a concomitant decrease in [3H]thymidine incorporation (52 +/- 14% compared with control culture). Human GH (hGH; 50 micrograms/l) and IGF-I (25 micrograms/l) had no stimulatory effect on ALP activity. However IGF-I (10 micrograms/l) exerted an inhibition on the T3 (10 micrograms/l)-induced increase in ALP activity (64 +/- 9% compared with T3-treated culture). T3 (3 micrograms/l) inhibited the increase in [3H]thymidine incorporation caused by 25 micrograms IGF-I/l (51 +/- 13% compared with IGF-I-treated culture). Furthermore, IGF-I receptor mRNA levels were increased by 10 micrograms T3/l (137 +/- 4.2% compared with control culture) while no effect of hGH (50 micrograms/l) or IGF-I (25 micrograms/l) was demonstrated. Both T3 and IGF-I were shown to interact with epiphyseal chondrocytes and both substances seemed to affect cell proliferation and maturation and therefore longitudinal bone growth. Furthermore, the results indicated that IGF-I is important for proliferation of the cells while T3 initiates the terminal differentiation of epiphyseal chondrocytes.
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12. |
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13. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Establishment of a growth hormone responsive chondrogenic cell line from fetal rat tibia.
- 1993
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Ingår i: Molecular and cellular endocrinology. - 0303-7207. ; 91:1-2, s. 167-75
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Tidskriftsartikel (refereegranskat)abstract
- Reproducible effects of growth hormone (GH) on primary isolated cells in monolayer are highly dependent on the culture conditions and/or the fraction of GH responsive cells. To study the effect of GH at the cellular level, a homogenous cell line with both GH responsiveness and chondrogenic properties was established. Primary isolated cells from 18-day-old fetal rat tibia were subcultured using a strict protocol for passages (every third day and a seeding density of 15,000/cm2). Of six established cell lines, one fetal tibia cell line No. 5 (FTC 5) expressed adipogenic and chondrogenic properties at a low frequency. Cells from FTC 5 were subcultured in soft agar suspension with the addition of bovine GH (100 ng/ml). After 14 days in culture eight monoclonal cell lines were established from individual large colonies. Two subclones, FTC 5:3 and FTC 5:6, expressed a chondrogenic phenotype as demonstrated by chondrocyte foci, alcian blue staining and production of type II collagen. Further characterization of FTC 5:3 revealed specific binding of bovine GH with an affinity of 1.7 x 10(9) M-1, and approximately 7300 receptors/cell. Northern blot analysis of FTC 5:3 with a 32P-labeled RNA probe complementary to an extracellular part of the rat GH receptor, revealed two major labeled bands (4.0 and 1.2 kilobases). Both GH and insulin-like growth factor-I (IGF-I) stimulated 3H-thymidine uptake in FTC 5:3 (194 +/- 28% and 405 +/- 127% over control, respectively), while proteoglycan synthesis, as measured by [35S]sulphate uptake, was stimulated by IGF-I only (101 +/- 18% over control).(ABSTRACT TRUNCATED AT 250 WORDS)
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14. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Growth hormone induces multiplication of the slowly cycling germinal cells of the rat tibial growth plate.
- 1992
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424. ; 89:20, s. 9826-30
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Tidskriftsartikel (refereegranskat)abstract
- To study the effect of locally infused growth hormone (GH) or insulin-like growth factor I(IGF-I) on slowly cycling cells in the germinal cell layer of the tibial growth plate, osmotic minipumps delivering 14.3 microCi of [3H]thymidine per day were implanted s.c. into hypophysectomized rats, and GH (1 microgram) or IGF-I (10 micrograms) was injected daily through a cannula implanted in the proximal tibia. The opposite leg served as a control. After 12 days of treatment, the osmotic minipumps were removed, and three rats in each group were given GH (20 micrograms/day, s.c.) for an additional 14 days to chase the labeled cells out of the proliferative layers. Labeled cells remained in the germinal layer, in the perichondrial ring, and on the surface of the articular cartilage close to the epiphyseal plate. GH administered together with labeled thymidine significantly increased the number of labeled cells in the germinal cell layer compared to that in the control leg (ratio = 1.95 +/- 0.13), whereas IGF-I showed no stimulatory effect (ratio = 0.96 +/- 0.04). Therefore GH but not IGF-I stimulates the multiplication of the slowly cycling (label-retaining) cells in the germinal layer of the epiphyseal plate. IGF-I acts only on the proliferation of the resulting chondrocytes.
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15. |
- Sarwar, Nadeem, et al.
(författare)
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Interleukin-6 receptor pathways in coronary heart disease : a collaborative meta-analysis of 82 studies
- 2012
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Ingår i: The Lancet. - New York, NY, USA : Elsevier. - 0140-6736 .- 1474-547X. ; 379:9822, s. 1205-1213
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Tidskriftsartikel (refereegranskat)abstract
- Background: Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling. Methods: In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125 222 participants. We also compared the frequency of Asp358Ala in 51 441 patients with coronary heart disease and in 136 226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6. Findings: The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele >= 0.04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34.3% (95% CI 30.4-38.2) and of interleukin 6 by 14.6% (10.7-18.4), and mean concentration of C-reactive protein was reduced by 7.5% (5.9-9.1) and of fibrinogen by 1.0% (0.7-1.3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3.4% (1.8-5.0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes. Interpretation: Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease.
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16. |
- Shungin, Dmitry, et al.
(författare)
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New genetic loci link adipose and insulin biology to body fat distribution.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 187-378
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Tidskriftsartikel (refereegranskat)abstract
- Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
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17. |
- Bellman, Jakob, et al.
(författare)
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Loading enhances glucose uptake in muscles, bones, and bone marrow of lower extremities in humans.
- 2024
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Ingår i: The Journal of clinical endocrinology and metabolism. - 1945-7197.
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Tidskriftsartikel (refereegranskat)abstract
- Increased standing time has been associated with improved health, but the underlying mechanism is unclear.We herein investigate if increased weight loading increases energy demand and thereby glucose uptake (GU) locally in bone and/or muscle in the lower extremities.In this single-center clinical trial with randomized crossover design (ClinicalTrials.gov ID, NCT05443620), we enrolled 10 men with body mass index (BMI) between 30 and 35kg/m2. Participants were treated with both high load (standing with weight vest weighing 11% of body weight) and no load (sitting) on the lower extremities. GU was measured using whole-body quantitative positron emission tomography/computed tomography (PET/CT) imaging. The primary endpoint was the change in GU ratio between loaded bones (i.e. femur and tibia) and non-loaded bones (i.e. humerus).High load increased the GU ratio between lower and upper extremities in cortical diaphyseal bone (e.g. femur/humerus ratio increased by 19%, p=0.029), muscles (e.g. m. quadriceps femoris/m. triceps brachii ratio increased by 28%, p=0.014) and in certain bone marrow regions (femur/humerus diaphyseal bone marrow region ratio increased by 17%, p=0.041). Unexpectedly, we observed the highest GU in the bone marrow region of vertebral bodies, but its GU was not affected by high load.Increased weight-bearing loading enhances GU in muscles, cortical bone, and bone marrow of the exposed lower extremities. This could be interpreted as increased local energy demand in bone and muscle caused by increased loading. The physiological importance of the increased local GU by static loading remains to be determined.
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18. |
- Bentmar Holgersson, Magdalena, et al.
(författare)
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Lower prostate cancer risk in Swedish men with the androgen receptor E213 A-allele
- 2017
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Ingår i: Cancer Causes & Control. - : Springer Science and Business Media LLC. - 0957-5243 .- 1573-7225. ; 28:3, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- In a previous population-based study on 3369 European men with self-reported prostate cancer (PCa), it was shown that androgen receptor (AR) haplotype designated H2 was associated with high levels of serum PSA (prostate-specific antigen) concentration, and, at the same time, with low risk for PCa. The aim of this study was to replicate this finding in other cohorts, with registry-based cancer diagnosis. Using data from two population-based cohorts; the Malmo Diet and Cancer Study (MDCS, n = 12,121) and the Swedish Osteoporotic fractures in men study (MrOS, n = 1,120), 628 men with PCa and 1,374 controls were identified and genotyped. PCa data were collected from the Swedish national cancer registry. PCa odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for carriers of the particular AR haplotype, tagged by the rs6624304 T-allele. The 15% of men who were carriers of the AR haplotype H2 had approximately one-third lower risk for PCa diagnosis compared to those with the most common H1 variant (OR 0.65; 95% CI 0.45-0.94; p = 0.021). The same trend, although not statistically significant (OR 0.75; 95% CI 0.47-1.24; p = 0.275), was observed in MrOS Sweden. When both cohorts were merged, an even more significant result was observed (OR 0.68; 95% CI 0.51-0.90; p = 0.008). Swedish men with the variant AR haplotype H2, tagged by rs6624304, have significantly lower risk of PCa compared to those with the more common variant.
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19. |
- Berndt, Sonja I., et al.
(författare)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Tidskriftsartikel (refereegranskat)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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20. |
- Borg, Farhana, Lektor, 1967-, et al.
(författare)
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Eco-certified Preschools and Children's Learning for Sustainability : Researching Holistic Outcomes of Preschool Education for Sustainability (HOPES)
- 2020
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Konferensbidrag (refereegranskat)abstract
- Purpose of the researchAlthough Sweden being an active initiator in the promotion of education for sustainability (EfS), there is a knowledge gap about children’s learning for sustainability and the pedagogical practices of sustainability in preschool education. Moreover, there is an overall lack of generalizable studies in this field. The purpose of this study, funded by the Swedish Research Council 2019-2022 (VR 2018-04445), is to contribute to evidence-informed development of pedagogical practices that facilitate children’s learning for sustainability at preschools. The objectives are:to explore and compare knowledge, attitude and behaviors among children, who attend eco- and non-eco-certified preschools;to identify and compare preschool teachers’ self-reported pedagogical practices of EfS at eco- and non-eco-certified preschools; andto investigate the extent to which eco-certification and preschool teachers’ pedagogical practices in EfS relate to children’s learning for sustainability.In this study, eco-certified preschools refer to those preschools that work explicitly with EfS and have been awarded with the certifications, either Green Flag by the Keep Sweden Tidy or Preschool for Sustainability by Skolverket. The study uses: integrated perspective on sustainability, in which environmental, social, and economic aspects are interconnected; pluralistic teaching methods; and transformative learning.Research design and methodsThe study applies a mixed methods design that combines cross-sectional qualitative and quantitative research approaches. Two-stage cluster random sampling is used to select participating preschools (n=50). A sampling frame consisting of all municipalities in Sweden that have at least two eco-certified preschools and two non-eco-certified preschools is created based on information from municipalities and organizations that award eco-certificates. A randomized sampling is used to select 25 municipalities from all over the country. Preschool children (n=300) and teachers (n=16) are interviewed, a questionnaire study is conducted among preschool teachers (n=300), and video observations of preschools’ (n=4) pedagogical practices of EfS is carried out. Demographical information of 25 eco- and 25 non-eco-certified preschools is collected from preschool principals. Content analyses, as well as descriptive and inferential statistics are applied.The Swedish Ethical Review Authority did not have any ethical objections about this project (EPN 2020-00005). Major resultsCurrently the pilot studies are going on, and so far, children’s (n=12) from 3 preschools, teachers’ (n=3) from 3 preschools as well as video observations of one preschool’s pedagogical practices of EfS were conducted. The analyses of the findings from the pilot studies are expected to be ready and presented at the symposium.ConclusionThis study will provide insights into the role of EfS in preschool education in relation to children’s knowledge, attitudes and behaviors concerning sustainability, preschool teachers’ pedagogical practices, as well as the importance of eco-certification in relation to sustainability education in Sweden. Relevance to sustainable development and Agenda 2030This project is explicitly connected to education for sustainability that addresses issues related to taking actions for saving the planet and living in harmony with people and its surrounding environments. It also addresses goal 4.7 of the 2030 Agenda for sustainability that urges that all learners must acquire the knowledge and skills needed to promote sustainability.
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21. |
- Carlsson, Björn, 1958, et al.
(författare)
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Expression and physiological significance of growth hormone receptors and growth hormone binding proteins in rat and man.
- 1991
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Ingår i: Acta paediatrica Scandinavica. Supplement. - 0300-8843. ; 379
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Tidskriftsartikel (refereegranskat)abstract
- The molecular structure of the GH receptor has recently been characterized and the receptor identified as a member of a new receptor superfamily that includes the prolactin receptor and several cytokine receptors. No obvious signal transducing domain has been identified on any of these related receptors. One possible signalling mechanism involves receptor interaction with other membrane-associated proteins that function as mediators of signal transduction. Whether such a mechanism is involved in signal transduction of the GH receptor is not known. Another common feature of these receptors is the presence of soluble forms such as the GHBP. The functions of these proteins in the circulation and at the level of the target cell remain to be resolved.
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22. |
- Engstrand, Thomas, et al.
(författare)
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A novel biodegradable delivery system for bone morphogenetic protein-2.
- 2008
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Ingår i: Plastic and reconstructive surgery. - 1529-4242. ; 121:6, s. 1920-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The efficacy of recombinant growth factors in vivo is highly dependent on the delivery vehicle. The authors investigated the osteoinductive effects of recombinant human bone morphogenetic proteins (BMP)-2 implanted together with a complex of heparin and chitosan. METHODS: Sixty rats were used. Three different carriers in gel formulation (type I collagen, heparin/type I collagen, and heparin/chitosan) were mixed with either 0, 10, or 50 microg of BMP-2, making the number of groups nine. The gels were injected into the quadriceps muscles of both legs in 45 rats (n = 10 per group). Freeze-dried formulations of the carriers were also tested with the same amounts of BMP-2 using 15 rats (n = 5 per group). Four weeks after implantation, the quality and amount of newly formed bone were assessed. RESULTS: Chitosan was shown to protect the heparinase-mediated degradation of heparin in vitro. The osteoinductive effects of BMP-2 in combination with heparin/chitosan were superior as compared with BMP-2 implanted together with type I collagen. Interestingly, the heparin/chitosan complex induced a small amount of bone also without BMP-2 added. The heparin/chitosan was completely absorbed after 4 weeks as determined by histologic evaluation, and a normal active bone formation was present. The freeze-dried formulations of the carriers demonstrated similar osteoinductive effects as the gels. CONCLUSIONS: An osteoinductive formula for clinical use is needed for general bone reconstruction. Heparin in complex with chitosan has the ability to stabilize or activate the growth factor in vivo and induce the generation of new bone in good yields.
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23. |
- Eriksson, Anna-Lena, 1971, et al.
(författare)
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Association between the low activity genotype of catechol-O-methyltransferase and myocardial infarction in a hypertensive population
- 2004
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Ingår i: Eur Heart J. ; 25:5, s. 386-91
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Estrogens regulate several biological processes involved in the pathogenesis of myocardial infarction. Catechol-O-methyltransferase (COMT) is a key enzyme in the degradation of estrogens. There is a functional polymorphism in the COMT gene (Val158Met), affecting the activity of the enzyme. We investigated if the low activity genotype of COMT is associated with an altered risk of myocardial infarction. METHODS AND RESULTS: In a prospectively followed hypertensive cohort we identified 174 patients who suffered a myocardial infarction during the study and compared them to 348 controls from the same cohort. The COMT polymorphism and serum levels of sex hormones were analysed. Patients homozygous for the low activity COMT genotype had a decreased risk of myocardial infarction compared to those with the high activity genotype, odds ratio 0.65 (95% CI 0.44-0.97, p=0.033 ). The protective effect of the low activity genotype was most evident among older patients (> 58 years of age), odds ratio 0.43 (95% CI 0.23-0.79, p=0.006 ). Serum levels of estradiol were increased ( p=0.006 ) in males with the low activity genotype. CONCLUSIONS: Our findings suggest that the low activity COMT genotype is protective against myocardial infarction. One may speculate that the altered estrogen status could be involved in this effect.
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24. |
- Eriksson, Anna-Lena, 1971, et al.
(författare)
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SHBG gene promoter polymorphisms in men are associated with serum sex hormone-binding globulin, androgen and androgen metabolite levels, and hip bone mineral density.
- 2006
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 91:12, s. 5029-37
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: SHBG regulates free sex steroid levels, which in turn regulate skeletal homeostasis. Twin studies have demonstrated that genetic factors largely account for interindividual variation in SHBG levels. Glucuronidated androgen metabolites have been proposed as markers of androgenic activity. OBJECTIVE: Our objective was to investigate whether polymorphisms in the SHBG gene promoter [(TAAAA)(n) microsatellite and rs1799941 single-nucleotide polymorphism] are associated with serum levels of SHBG, sex steroids, or bone mineral density (BMD) in men. DESIGN AND STUDY SUBJECTS: We conducted a population-based study of two cohorts of Swedish men: elderly men (MrOS Sweden; n congruent with 3000; average age, 75.4 yr) and young adult men (GOOD study; n = 1068; average age, 18.9 yr). MAIN OUTCOME MEASURES: We measured serum levels of SHBG, testosterone, estradiol, dihydrotestosterone, 5alpha-androstane-3alpha,17beta-diol glucuronides, androsterone glucuronide, and BMD determined by dual-energy x-ray absorptiometry. RESULTS: In both cohorts, (TAAAA)(n) and rs1799941 genotypes were associated with serum levels of SHBG (P < 0.001), dihydrotestosterone (P < 0.05), and 5alpha-androstane-3alpha,17beta-diol glucuronides (P < 0.05). In the elderly men, they were also associated with testosterone and BMD at all hip bone sites. The genotype associated with high levels of SHBG was also associated with high BMD. Interestingly, male mice overexpressing human SHBG had increased cortical bone mineral content in the femur, suggesting that elevated SHBG levels may cause increased bone mass. CONCLUSIONS: Our findings demonstrate that polymorphisms in the SHBG promoter predict serum levels of SHBG, androgens, and glucuronidated androgen metabolites, and hip BMD in men.
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25. |
- Franks, P. W., et al.
(författare)
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Technological readiness and implementation of genomic-driven precision medicine for complex diseases
- 2021
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 290:3, s. 602-620
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Forskningsöversikt (refereegranskat)abstract
- The fields of human genetics and genomics have generated considerable knowledge about the mechanistic basis of many diseases. Genomic approaches to diagnosis, prognostication, prevention and treatment - genomic-driven precision medicine (GDPM) - may help optimize medical practice. Here, we provide a comprehensive review of GDPM of complex diseases across major medical specialties. We focus on technological readiness: how rapidly a test can be implemented into health care. Although these areas of medicine are diverse, key similarities exist across almost all areas. Many medical areas have, within their standards of care, at least one GDPM test for a genetic variant of strong effect that aids the identification/diagnosis of a more homogeneous subset within a larger disease group or identifies a subset with different therapeutic requirements. However, for almost all complex diseases, the majority of patients do not carry established single-gene mutations with large effects. Thus, research is underway that seeks to determine the polygenic basis of many complex diseases. Nevertheless, most complex diseases are caused by the interplay of genetic, behavioural and environmental risk factors, which will likely necessitate models for prediction and diagnosis that incorporate genetic and non-genetic data.
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26. |
- Frost, Anders, et al.
(författare)
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Interleukin-13 inhibits cell proliferation and stimulates interleukin-6 formation in isolated human osteoblasts.
- 1998
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Ingår i: The Journal of clinical endocrinology and metabolism. - 0021-972X. ; 83:9, s. 3285-9
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-13 (IL-13) is a recently identified cytokine that is secreted by activated T cells and regulates inflammatory responses. We have investigated the effects of IL-13 on isolated human osteoblast-like cells (hOB). IL-13 dose-dependently (1-100 pmol/L) reduced the incorporation rate of [3H]thymidine in hOB cells by more than 50%. Using a cell metabolic assay as well as direct cell counting, we found that treatment with IL-13 lead to a decrease in hOB cell number. The effect was both time and dose dependent, and after 12 days of culture, treatment with IL-13 (0.1 nmol/L) caused a 70% decrease in the number of cells. Also, IL-13 increased the levels of IL-6 messenger ribonucleic acid in hOBs, as measured by ribonuclease protection assay, and stimulated secretion of IL-6 into culture supernatants. In conclusion, IL-13 inhibits cell proliferation and increases IL-6 formation in human osteoblasts. Our findings suggest that IL-13 may cause bone loss due to impaired osteoblastic growth and IL-6-induced osteoclast recruitment.
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27. |
- Hagberg Thulin, Malin, et al.
(författare)
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Inhibition of STAT3 prevents bone metastatic progression of prostate cancer in vivo
- 2021
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Ingår i: Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 81:8, s. 452-462
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Tidskriftsartikel (refereegranskat)abstract
- Background Prostate cancer (PC) metastasizes to the skeleton forming predominantly sclerotic lesions, and there is currently no cure for bone metastatic disease. The transcription factor signal transducer and activator of transcription 3 (STAT3) is implicated as a metastatic driver, but its potential as therapeutic target in bone metastasis has not been investigated. In this study, we evaluated for the first time a STAT3 inhibitor, Napabucasin, as a therapeutic option for bone metastatic PC. Methods Effects of STAT3 inhibitors, Stattic and Napabucasin, on metastatic potential in PC cells were studied in vitro by assessment of migration capacity, self-renewal potential, and tumorsphere formation. For evaluation of the role of STAT3 in initial skeletal establishment of PC cells as well as in progressed castration-resistant PC (CRPC) in bone, human VCaP prostate cancer cells were inoculated in the tibia of mice which subsequently were treated with the STAT3 inhibitor Napabucasin. Bone specimens were analyzed using computed tomography (CT), immunohistochemistry, and quantitative polymerase chain reaction. Results The small molecule STAT3 inhibitors Stattic and Napabucasin both effectively impaired metastatic potential of PC cells in vitro. Furthermore, treatment with Napabucasin prevented metastatic establishment in tibial bones in vivo and thereby also the tumor-induced sclerotic bone response seen in vehicle-treated VCaP xenografts. In addition, treatment with Napabucasin of established bone CRPC significantly decreased both tumor burden and tumor-induced trabecular bone volume compared with effects seen in vehicle-treated animals. Anti-mitotic effects were confirmed by decreased Ki67 staining in Napabucasin-treated xenografts compared with vehicle-treated xenografts. Alterations of gene expression in the femoral bone marrow (BM) niche toward the maintenance of hematopoietic stem cells and the myeloid lineage were demonstrated by quantitative real-time polymerase chain reaction and were further reflected by a substantial increase in the number of erythrocytes in BM of Napabucasin-treated mice. Furthermore, a unique pattern of STAT3 phosphorylation in osteoblasts/stromal cells surrounding the areas of tumor cells was demonstrated immunohistochemically in bone xenograft models using several different PC cell lines. Conclusion Inhibition of STAT3 activity disrupts the bone metastatic niche and targets both the skeletal establishment of PC and advanced bone metastatic CRPC in mice, suggesting STAT3 as a candidate for molecular targeted therapies of skeletal metastatic disease.
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28. |
- Harvey, Nicholas C., et al.
(författare)
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Falls Predict Fractures Independently of FRAX Probability : A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study
- 2018
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Ingår i: Journal of Bone and Mineral Research. - : WILEY. - 0884-0431 .- 1523-4681. ; 33:3, s. 510-516
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Tidskriftsartikel (refereegranskat)abstract
- Although prior falls are a well-established predictor of future fracture, there is currently limited evidence regarding the specific value of falls history in fracture risk assessment relative to that of other clinical risk factors and bone mineral density (BMD) measurement. We therefore investigated, across the three Osteoporotic Fractures in Men (MrOS) Study cohorts, whether past falls predicted future fracture independently of FRAX and whether these associations varied with age and follow-up time. Elderly men were recruited from MrOS Sweden, Hong Kong, and USA. Baseline data included falls history (over the preceding 12 months), clinical risk factors, BMD at femoral neck, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the associations between falls, FRAX probability, and incident fracture, adjusting for age, time since baseline, and cohort in base models; further models were used to investigate interactions with age and follow-up time. Random-effects meta-analysis was used to synthesize the individual country associations. Information on falls and FRAX probability was available for 4365 men in USA (mean age 73.5 years; mean follow-up 10.8 years), 1823 men in Sweden (mean age 75.4 years; mean follow-up 8.7 years), and 1669 men in Hong Kong (mean age 72.4 years; mean follow-up 9.8 years). Rates of past falls were similar at 20%, 16%, and 15%, respectively. Across all cohorts, past falls predicted incident fracture at any site (hazard ratio [HR]=1.69; 95% confidence interval [CI] 1.49, 1.90), major osteoporotic fracture (MOF) (HR=1.56; 95% CI 1.33, 1.83), and hip fracture (HR=1.61; 95% CI 1.27, 2.05). Relationships between past falls and incident fracture remained robust after adjustment for FRAX probability: adjusted HR (95% CI) any fracture: 1.63 (1.45, 1.83); MOF: 1.51 (1.32, 1.73); and hip: 1.54 (1.21, 1.95). In conclusion, past falls predicted incident fracture independently of FRAX probability, confirming the potential value of falls history in fracture risk assessment.
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29. |
- Harvey, N. C., et al.
(författare)
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FRAX predicts incident falls in elderly men : findings from MrOs Sweden
- 2016
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 27:1, s. 267-274
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Tidskriftsartikel (refereegranskat)abstract
- A Summary Falls and fractures share several common risk factors. Although past falls is not included as an input variable in the FRAX calculator, we demonstrate that FRAX probability predicts risk of incident falls in the MrOs Sweden cohort. Introduction Although not included in the FRAXA (R) algorithm, it is possible that increased falls risk is partly dependent on other risk factors that are incorporated into FRAX. The aim of the present study was to determine whether fracture probability generated by FRAX might also predict risk of incident falls and the extent that a falls history would add value to FRAX. Methods We studied the relationship between FRAX probabilities and risk of falls in 1836 elderly men recruited to the MrOS study, a population-based prospective cohort of men from Sweden. Baseline data included falls history, clinical risk factors, bone mineral density (BMD) at femoral neck, and calculated FRAX probabilities. Incident falls were captured during an average of 1.8 years of follow-up. An extension of Poisson regression was used to investigate the relationship between FRAX, other risk variables, and the time-to-event hazard function of falls. All associations were adjusted for age and time since baseline. Results At enrolment, 15.5 % of the men had fallen during the preceding 12 months (past falls) and 39 % experienced one or more falls during follow-up (incident falls). The risk of incident falls increased with increasing FRAX probabilities at baseline (hazard ratio (HR) per standard deviation (SD), 1.16; 95 % confidence interval (95%CI), 1.06 to 1.26). The association between incident falls and FRAX probability remained after adjustment for past falls (HR per SD, 1.12; 95%CI, 1.03 to 1.22). High compared with low baseline FRAX score (>15 vs <15 % probability of major osteoporotic fracture) was strongly predictive of increased falls risk (HR, 1.64; 95%CI, 1.36 to 1.97) and remained stable with time. Whereas past falls were a significant predictor of incident falls (HR, 2.75; 95%CI, 2.32 to 3.25), even after adjustment for FRAX, the hazard ratio decreased markedly with increasing follow-up time. Conclusions Although falls are not included as an input variable, FRAX captures a component of risk for future falls and outperforms falls history with an extended follow-up time.
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30. |
- Harvey, Nicholas C., et al.
(författare)
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Measures of Physical Performance and Muscle Strength as Predictors of Fracture Risk Independent of FRAX, Falls, and aBMD : A Meta-Analysis Of The Osteoporotic Fractures In Men (MrOS) Study
- 2018
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 33:12, s. 2150-2157
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Tidskriftsartikel (refereegranskat)abstract
- Measures of muscle mass, strength, and function predict risk of incident fractures, but it is not known whether this risk information is additive to that from FRAX (fracture risk assessment tool) probability. In the Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, Hong Kong, United States), we investigated whether measures of physical performance/appendicular lean mass (ALM) by DXA predicted incident fractures in older men, independently of FRAX probability. Baseline information included falls history, clinical risk factors for falls and fractures, femoral neck aBMD, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the relationship between time for five chair stands, walking speed over a 6 m distance, grip strength, ALM adjusted for body size (ALM/height(2)), FRAX probability (major osteoporotic fracture [MOF]) with or without femoral neck aBMD, available in a subset of n = 7531), and incident MOF (hip, clinical vertebral, wrist, or proximal humerus). Associations were adjusted for age and time since baseline, and are reported as hazard ratios (HRs) for first incident fracture per SD increment in predictor using meta-analysis. 5660 men in the United States (mean age 73.5 years), 2764 men in Sweden (75.4 years), and 1987 men in Hong Kong (72.4 years) were studied. Mean follow-up time was 8.7 to 10.9 years. Greater time for five chair stands was associated with greater risk of MOF (HR 1.26; 95% CI, 1.19 to 1.34), whereas greater walking speed (HR 0.85; 95% CI, 0.79 to 0.90), grip strength (HR 0.77; 95% CI, 0.72 to 0.82), and ALM/height(2) (HR 0.85; 95% CI, 0.80 to 0.90) were associated with lower risk of incident MOF. Associations remained largely similar after adjustment for FRAX, but associations between ALM/height(2) and MOF were weakened (HR 0.92; 95% CI, 0.85 to 0.99). Inclusion of femoral neck aBMD markedly attenuated the association between ALM/height(2) and MOF (HR 1.02; 95% CI, 0.96 to 1.10). Measures of physical performance predicted incident fractures independently of FRAX probability. Whilst the predictive value of ALM/height(2) was substantially reduced by inclusion of aBMD requires further study, these findings support the consideration of physical performance in fracture risk assessment.
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31. |
- Heid, Iris M, et al.
(författare)
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Meta-analysis identifies 13 new loci associated with waist-hip ratio and reveals sexual dimorphism in the genetic basis of fat distribution
- 2010
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 42:11, s. 949-960
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Tidskriftsartikel (refereegranskat)abstract
- Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻¹³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.
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32. |
- Hägg, Daniel, 1974, et al.
(författare)
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Osteoblast-lineage cells regulate metabolism and fat mass
- 2023
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Ingår i: Current Opinion in Endocrine and Metabolic Research. - 2451-9650. ; 31
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Forskningsöversikt (refereegranskat)abstract
- As energy depots in many circumstances have been limited during evolution, it is necessary to prioritize how to manage energy resources. In this review we summarize data from the last 15 years indicating that osteoblast-lineage cells are regulators of whole-body energy metabolism and fat mass. We focus mainly on three factors, osteocalcin, lipocalin-2 and sclerostin, that are released by osteoblast-lineage cells and proposed to exert endocrine effects on metabolism. In addition, we present a hypothesis on why osteoblast-lineage cells during evolution have developed a function to regulate metabolism and fat mass. We propose that osteoblast-lineage cells through the osteocyte network in bone are sensors of gravitational forces induced by body mass and gravity on land-living species. By sensing the body weight, the osteoblastlineage cells may then feed-back this information on the whole-body nutritional status via osteoblast-derived endocrine factors or via the nervous system to regulate energy metabolism and fat mass.
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33. |
- Jakobsson, J, et al.
(författare)
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A novel polymorphism in the 17beta-hydroxysteroid dehydrogenase type 5 (aldo-keto reductase 1C3) gene is associated with lower serum testosterone levels in caucasian men.
- 2007
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Ingår i: The pharmacogenomics journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 7:4, s. 282-9
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variation in the androgen metabolizing enzymes is important to identify and feature as they may influence the risk of prostate cancer and help clarify the etiology of the disease. Human 17beta-hydroxysteroid dehydrogenase type 5 (AKR1C3) is highly expressed in the prostate gland and plays a major role in the formation and metabolism of androgens. We identified five novel polymorphisms in the AKR1C3 gene. One of those an A>G substitution in exon 2 that confers a Glu77Gly change occurred in 4.8% in Caucasians but was completely absent in Orientals. Interestingly, the testosterone level in serum was significantly lower in subjects with the Gly77 allele. A promoter A>G polymorphism was associated with significantly altered promoter activity in reporter constructs, but was not associated with any change in testosterone levels. In conclusion, the Glu77Gly polymorphism is associated with lower testosterone levels in serum.
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34. |
- Jakobsson, Jenny, et al.
(författare)
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Large differences in testosterone excretion in Korean and Swedish men are strongly associated with a UDP-glucuronosyl transferase 2B17 polymorphism.
- 2006
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 91:2, s. 687-93
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: The reproductive endocrinology in Asians and Caucasians is of great interest in view of large differences in prostate cancer rate and sensitivity to pharmacological male contraception. In addition, interpretation of certain antidoping tests is confounded by interethnic variation in androgen disposition. Uridine diphosphoglucuronosyl transferases have a key role in the homeostasis and metabolism of androgens. Recently a deletion polymorphism was detected in the UGT2B17 gene. OBJECTIVE: The objective of the study was to evaluate the contribution of the UGT2B17 deletion polymorphism to the interindividual and interethnic variation of androgen metabolism and excretion. METHODS AND RESULTS: Urine from 122 Swedish and 74 Korean healthy men was analyzed for several androgen glucuronides including testosterone. The distribution of the natural logarithms of urinary testosterone concentrations showed a distinct bimodal pattern in both groups, suggesting a monogenic inheritance. When the UGT2B17 genotypes were compared with urinary testosterone levels, all of the individuals of the UGT2B17 homozygous deletion/deletion genotype had no or negligible amounts of urinary testosterone. The deletion/deletion genotype was seven times more common in the Korean (66.7%) than the Swedish population (9.3%). In addition, the Swedes had significantly higher levels of serum testosterone, compared with the Koreans. CONCLUSIONS: Our results show that the UGT2B17 polymorphism is strongly associated with the bimodal distribution of the testosterone excretion and also with the large differences in testosterone excretion between Koreans and Swedes.
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35. |
- Jansson, John-Olov, 1954, et al.
(författare)
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A Body Weight Sensor Regulates Prepubertal Growth via the Somatotropic Axis in Male Rats
- 2021
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 162:6
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Tidskriftsartikel (refereegranskat)abstract
- In healthy conditions, prepubertal growth follows an individual specific growth channel. Growth hormone (GH) is undoubtedly the major regulator of growth. However, the homeostatic regulation to maintain the individual specific growth channel during growth is unclear. We recently hypothesized a body weight sensing homeostatic regulation of body weight during adulthood, the gravitostat. We now investigated if sensing of body weight also contributes to the strict homeostatic regulation to maintain the individual specific growth channel during prepubertal growth. To evaluate the effect of increased artificial loading on prepubertal growth, we implanted heavy (20% of body weight) or light (2% of the body weight) capsules into the abdomen of 26-day-old male rats. The body growth, as determined by change in biological body weight and growth of the long bones and the axial skeleton, was reduced in rats bearing a heavy load compared with light load. Removal of the increased load resulted in a catch-up growth and a normalization of body weight. Loading decreased hypothalamic growth hormone releasing hormone mRNA, liver insulin-like growth factor (IGF)-1 mRNA, and serum IGF-1, suggesting that the reduced body growth was caused by a negative feedback regulation on the somatotropic axis and this notion was supported by the fact that increased loading did not reduce body growth in GH-treated rats. Based on these data, we propose the gravitostat hypothesis for the regulation of prepubertal growth. This states that there is a homeostatic regulation to maintain the individual specific growth channel via body weight sensing, regulating the somatotropic axis and explaining catch-up growth.
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36. |
- Jansson, John-Olov, 1954, et al.
(författare)
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The dual hypothesis of homeostatic body weight regulation, including gravity-dependent and leptin-dependent actions.
- 2023
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Ingår i: Philosophical transactions of the Royal Society of London. Series B, Biological sciences. - 1471-2970. ; 378:1888
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Forskningsöversikt (refereegranskat)abstract
- Body weight is tightly regulated when outside the normal range. It has been proposed that there are individual-specific lower and upper intervention points for when the homeostatic regulation of body weight is initiated. The nature of the homeostatic mechanisms regulating body weight at the lower and upper ends of the body weight spectrum might differ. Previous studies demonstrate that leptin is the main regulator of body weight at the lower end of the body weight spectrum. We have proposed that land-living animals use gravity to regulate their body weight. We named this homeostatic system the gravitostat and proposed that there are two components of the gravitostat. First, an obvious mechanism involves increased energy consumption in relation to body weight when working against gravity on land. In addition, we propose that there exists a component, involving sensing of the body weight by osteocytes in the weight-bearing bones, resulting in a feedback regulation of energy metabolism and body weight. The gravity-dependent homeostatic regulation is mainly active in obese mice. We, herein, propose the dual hypothesis of body weight regulation, including gravity-dependent actions (= gravitostat) at the upper end and leptin-dependent actions at the lower end of the body weight spectrum. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
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37. |
- Jansson, Per-Anders, 1961, et al.
(författare)
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Probiotic treatment using a mix of three Lactobacillus strains for lumbar spine bone loss in postmenopausal women: a randomised, double-blind, placebo-controlled, multicentre trial
- 2019
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Ingår i: Lancet Rheumatology. - : Elsevier BV. - 2665-9913. ; 1:3
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Tidskriftsartikel (refereegranskat)abstract
- Background Postmenopausal bone loss in the spine is associated with an increased risk of vertebral fractures. Certain probiotic treatment protects rodents from ovariectomy-induced bone loss. The aim of the present study was to determine if treatment with a combination of three bacterial strains protects against the rapid spine bone loss occurring in healthy early postmenopausal women. Methods This randomised, double-blind, placebo-controlled, multicentre trial was done at four study centres in Sweden. Early postmenopausal women were randomly assigned in a 1:1 ratio to receive probiotic treatment consisting of three Lactobacillus strains (Lactobacillus paracasei DSM 13434, Lactobacillus plantarum DSM 15312, and Lactobacillus plantarum DSM 15313; 1 x 10(10 )colony-forming units per capsule) or placebo once daily for 12 months. The primary outcome was the percentage change from baseline in lumbar spine bone mineral density (LS-BMD) at 12 months. The primary analysis was done in all participants with BMD measurements available both at baseline and at 12 months. Analyses of adverse events and safety included all participants who had taken at least one capsule of placebo or Lactobacillus. This trial is registered with ClinicalTrials.gov, NCT02722980, and is completed. Findings Between April 18 and Nov 11,2016,249 participants were randomly assigned to receive probiotic product or placebo, and 234 (94%) completed the analyses required for the primary outcome. Lactobacillus treatment reduced the LS-BMD loss compared with placebo (mean difference 0.71%, 95% CI 0.06 to 1.35). The LS-BMD loss was significant in the placebo group (-0.72%, -1.22 to -0.22), whereas no bone loss was observed in the Lactobacillus-treated group (-0.01%, -0.50 to 0.48). The adverse events were similar between the two groups. Interpretation Probiotic treatment using a mix of three Lactobacillus strains protects against lumbar spine bone loss in healthy postmenopausal women. Copyright (C) 2019 Elsevier Ltd. All rights reserved.
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38. |
- Jedel, Elizabeth, 1962, et al.
(författare)
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Impact of electroacupuncture and exercise on hyperandrogenism and oligo/amenorrhoea in women with polycystic ovary syndrome: A randomized controlled trial.
- 2011
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Ingår i: American Journal of Physiology - Endocrinology and Metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 300:1, s. E37-45
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Tidskriftsartikel (refereegranskat)abstract
- Background: Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age, is characterized by hyperandrogenism, oligo/amenorrhea, and polycystic ovaries. We aimed to determine whether low-frequency electro-acupuncture (EA) decreases hyperandrogenism and improves oligo/amenorrhea more effectively than physical exercise or no intervention. Methods: We randomized 84 women with PCOS, aged 18-37 years, to 16 weeks of low-frequency EA, physical exercise, or no intervention. The primary outcome measure-changes in the concentration of total testosterone (T) at week 16 determined by gas and liquid chromatography/mass spectrometry-was analyzed by intention-to treat. Secondary outcome measures were changes in menstrual frequency; concentrations of androgens, estrogens, androgen precursors, glucuronidated androgen metabolites; and acne and hirsutism. Outcomes were assessed at baseline, after 16 weeks of intervention, and after a 16-week follow-up. Results: After 16 weeks of intervention, circulating T decreased by -25%, androsterone glucuronide by -30%, and androstane-3α, 17β-diol-3glucuronide by -28% in the EA group (P=0.038, 0.030, and 0.047, respectively vs. exercise); menstrual frequency increased to 0.69/month from 0.28 at baseline in the EA group (P=0.018 vs. exercise). After the 16-week follow-up, the acne score decreased by -32% in the EA group (P=0.006 vs. exercise). Both EA and exercise improved menstrual frequency and decreased the levels of several sex steroids at week 16 and at the 16-week follow-up, compared to no intervention. Conclusion/Significance: Low-frequency EA and physical exercise improved hyperandrogenism and menstrual frequency more effectively than no intervention in women with PCOS. Low-frequency EA was superior to physical exercise and may be useful for treating hyperandrogenism and oligo/amenorrhea.
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39. |
- Johansson, Helena, 1981, et al.
(författare)
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High serum adiponectin predicts incident fractures in elderly men: Osteoporotic fractures in men (MrOS) Sweden
- 2012
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 1523-4681 .- 0884-0431. ; 27:6, s. 1390-1396
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Tidskriftsartikel (refereegranskat)abstract
- Adipocytes and osteoblasts share a common progenitor, and there is, therefore, potential for both autocrine and endocrine effects of adiponectin on skeletal metabolism. The aim of the present study was to determine whether high serum adiponectin was associated with an increased risk of fracture in elderly men. We studied the relationship between serum adiponectin and the risk of fracture in 999 elderly men drawn from the general population and recruited to the Osteoporotic Fractures in Men (MrOS) study in Gothenburg, Sweden. Baseline data included general health questionnaires, lifestyle questionnaires, body mass index (BMI), bone mineral density (BMD), serum adiponectin, osteocalcin, and leptin. Men were followed for up to 7.4 years (average, 5.2 years). Poisson regression was used to investigate the relationship between serum adiponectin, other risk variables and the time-to-event hazard function of fracture. Median levels of serum adiponectin at baseline were 10.4 mu g/mL (interquartile range, 7.714.3). During follow-up, 150 men sustained one or more fractures. The risk of fracture increased in parallel with increasing serum adiponectin (hazard ratio [HR]/SD, 1.46; 95% confidence interval [CI], 1.231.72) and persisted after multivariate-adjusted analysis (HR/SD, 1.30; 95% CI, 1.091.55). Serum adiponectin shows graded stepwise association with a significant excess risk of fracture in elderly men that was independent of several other risk factors for fracture. Its measurement holds promise as a risk factor for fracture in men. (C) 2012 American Society for Bone and Mineral Research.
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40. |
- Johansson, Helena, 1981, et al.
(författare)
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Low bone mineral density is associated with increased mortality in elderly men : MrOS Sweden
- 2011
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 22:5, s. 1411-1418
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Tidskriftsartikel (refereegranskat)abstract
- We studied the nature of the relationship between bone mineral density (BMD) and the risk of death among elderly men. BMD was associated with mortality risk and was independent of adjustments for other co-morbidities. A piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD was associated with a substantial excess risk of death, whilst a higher than average BMD had little impact on mortality. Previous studies have demonstrated an association between low BMD and an increased risk of death among men and women. The aim of the present study was to examine the pattern of the risk in men and its relation to co-morbidities. We studied the nature of the relationship between BMD and death among 3,014 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health questionnaires, life style questionnaires and BMD measured using DXA. Men were followed for up to 6.5 years (average 4.5 years). Poisson regression was used to investigate the relationship between BMD, co-morbidities and the hazard function of death. During follow-up, 382 men died (all-cause mortality). Low BMD at all measured skeletal sites was associated with increased mortality. In multivariate analyses, the relationship between BMD and mortality was non-linear, and a piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD is associated with a substantial excess risk of death compared to an average BMD, whereas a higher than average BMD has a more modest effect on mortality. These findings, if confirmed elsewhere, have implications for the constructing of probability-based fracture risk assessment tools.
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41. |
- Johansson, Helena, 1981, et al.
(författare)
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Low serum vitamin D is associated with increased mortality in elderly men: MrOS Sweden
- 2012
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 23:3, s. 991-999
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Tidskriftsartikel (refereegranskat)abstract
- In elderly man, low serum 25-hydroxyvitamin D (25(OH)D) was associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuated with time. The aim of the present study was to determine whether poor vitamin D status was associated with an increase in the risk of death in elderly men. We studied the relationship between serum 25(OH)D and the risk of death in 2,878 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health and lifestyle measures and serum 25(OH)D measured by competitive RIA. Men were followed for up to 8.2 years (average 6.0 years). Mortality adjusted for comorbidities decreased by 5% for each SD increase in 25(OH)D overall (gradient of risk 1.05; 95% confidence interval 0.96-1.14). The predictive value of 25(OH)D for death was greatest below a threshold value of 50-70 nmol/l, was greatest at approximately 3 years after baseline and thereafter decreased with time. Low serum 25(OH)D is associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuates with time. These findings, if causally related, have important implications for intervention in elderly men.
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42. |
- Johansson, Helena, 1981, et al.
(författare)
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Waning predictive value of serum adiponectin for fracture risk in elderly men: MrOS Sweden
- 2014
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 25:7, s. 1831-1836
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Tidskriftsartikel (refereegranskat)abstract
- Serum adiponectin is a risk factor for fracture. The predictive value attenuates with time in elderly men so that its use for the risk assessment in the long term is questionable. The study underlines the importance of testing the long-term stability of potential risk factors. High serum adiponectin is associated with an increased risk of fracture in elderly men. The aim of the present study was to determine the impact of adiponectin on the probability of fracture as a function of time. The probability of osteoporotic fracture was computed in 989 elderly men from the MrOS study in Sweden. Baseline data included clinical risk factors for fracture, femoral neck BMD and serum adiponectin. Men were followed for up to 7.4 years with a mean follow up of 5.3 years (range 0.0-7.4 years). Poisson regression was used to model the hazard function for osteoporotic fracture and death to determine the 10 year probability of fracture. During follow up, 124 men sustained one or more osteoporotic fracture. There was a significant interaction between adiponectin and time since baseline (p = 0.026) such that the longer time since baseline, the lower the gradient of fracture risk. When using this interaction in the calculation of 10-year probability of fracture, the probabilities of osteoporotic fracture varied little over the range of adiponectin values. Serum adiponectin is a risk factor for fracture. Nevertheless, the predictive value attenuates with time so that its use for the risk assessment in the long term is questionable. This study underlines the importance of testing the long-term stability of potential risk factors that might be used in fracture risk assessment.
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43. |
- Johansson, Per, 1966, et al.
(författare)
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Mild dementia is associated with increased adrenal secretion of cortisol and precursor sex steroids in women.
- 2011
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Ingår i: Clinical endocrinology. - : Wiley. - 1365-2265 .- 0300-0664. ; 75:3, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- Context Sex steroid levels decrease with increasing age, but little is known whether this is of importance for the age-related decline in cognitive function. Design and patients A cross-sectional study of 50 (26 men) consecutive patients under primary evaluation of cognitive impairment (D group) and 18 (9 men) matched healthy controls (C group). Measurements Sex steroid and precursor levels were determined in serum and, when measurable, in cerebrospinal fluid (CSF) using gas chromatography/mass spectroscopy (GC-MS) or liquid chromatography/mass spectroscopy (LC-MS). Sex hormone binding globulin (SHBG) and cortisol concentrations were measured using conventional assays. Results Patients in the D group had higher 24-h urine cortisol levels and increased serum levels of dehydroepiandrosterone (DHEA) and its sulphate ester dihydroepiandrosterone sulphate (DHEAS), androsterone (ADT), and oestrone (E1) and its sulphate ester E1S, compared with the controls. When men and women were analysed separately, increased serum concentrations of E1 and E1S were observed in both D men and D women, whereas increased levels of other sex steroids and cortisol were seen only in D women. Conclusions In both D men and women, serum E1 and E1S levels were increased, whereas other changes were gender specific and only seen in D women. Further studies are needed to determine whether these changes are a cause of, or merely a consequence of, cognitive impairment in elderly subjects.
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44. |
- Kilpeläinen, Tuomas O, et al.
(författare)
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Physical activity attenuates the influence of FTO variants on obesity risk: a meta-analysis of 218,166 adults and 19,268 children.
- 2011
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Ingår i: PLoS medicine. - : Public Library of Science (PLoS). - 1549-1676 .- 1549-1277. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n=218,166) and nine studies of children and adolescents (n=19,268). METHODS AND FINDINGS: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction) =0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio =1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio =1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. CONCLUSIONS: The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.
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45. |
- Lango Allen, Hana, et al.
(författare)
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Hundreds of variants clustered in genomic loci and biological pathways affect human height.
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 467:7317, s. 832-8
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Tidskriftsartikel (refereegranskat)abstract
- Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.
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46. |
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47. |
- McCloskey, Eugene V, et al.
(författare)
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A meta-analysis of trabecular bone score in fracture risk prediction and its relationship to FRAX
- 2016
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 31:5, s. 940-948
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Tidskriftsartikel (refereegranskat)abstract
- Trabecular bone score (TBS) is a grey-level textural index of bone microarchitecture derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images. TBS is a BMD-independent predictor of fracture risk. The objective of this meta-analysis was to determine whether TBS predicted fracture risk independently of FRAX probability and to examine their combined performance by adjusting the FRAX probability for TBS. We utilized individual level data from 17,809 men and women in 14 prospective population-based cohorts. Baseline evaluation included TBS and the FRAX risk variables and outcomes during follow up (mean 6.7 years) comprised major osteoporotic fractures. The association between TBS, FRAX probabilities and the risk of fracture was examined using an extension of the Poisson regression model in each cohort and for each sex and expressed as the gradient of risk (GR; hazard ratio per 1SD change in risk variable in direction of increased risk). FRAX probabilities were adjusted for TBS using an adjustment factor derived from an independent cohort (the Manitoba Bone Density Cohort). Overall, the GR of TBS for major osteoporotic fracture was 1.44 (95% CI: 1.35-1.53) when adjusted for age and time since baseline and was similar in men and women (p > 0.10). When additionally adjusted for FRAX 10-year probability of major osteoporotic fracture, TBS remained a significant, independent predictor for fracture (GR 1.32, 95%CI: 1.24-1.41). The adjustment of FRAX probability for TBS resulted in a small increase in the GR (1.76, 95%CI: 1.65, 1.87 vs. 1.70, 95%CI: 1.60-1.81). A smaller change in GR for hip fracture was observed (FRAX hip fracture probability GR 2.25 vs. 2.22). TBS is a significant predictor of fracture risk independently of FRAX. The findings support the use of TBS as a potential adjustment for FRAX probability, though the impact of the adjustment remains to be determined in the context of clinical assessment guidelines.
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48. |
- Mellström, Dan, 1945, et al.
(författare)
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Older men with low serum estradiol and high serum SHBG have an increased risk of fractures.
- 2008
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Ingår i: Journal of bone and mineral research. - 1523-4681. ; 23:10, s. 1552-60
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures constitute a major health concern not only in women but also in men. To study the predictive role of serum sex steroids for fracture risk in men, serum sex steroids were analyzed by the specific gas chromatography-mass spectrometry technique at baseline in older men (n = 2639; mean, 75 yr of age) of the prospective population-based MrOS Sweden cohort. Fractures occurring after baseline were validated (average follow-up of 3.3 yr). The incidence for having at least one validated fracture after baseline was 20.9/1000 person-years. Estradiol (E2; hazard ratio [HR] per SD decrease, 1.34; 95% CI, 1.22-1.49), free estradiol (fE2; HR per SD decrease, 1.41; 95% CI, 1.28-1.55), testosterone (T; HR per SD decrease, 1.27; 95% CI, 1.16-1.39), and free testosterone (fT; HR per SD decrease, 1.32; 95% CI, 1.21-1.44) were all inversely, whereas sex hormone-binding globulin (SHBG; HR per SD increase, 1.41; 95% CI, 1.22-1.63) was directly related to fracture risk. Multivariable proportional hazards regression models, adjusted for age, suggested that fE2 and SHBG (p < 0.001), but not fT, were independently associated with fracture risk. Further subanalyses of fracture type showed that fE2 was inversely associated with clinical vertebral fractures (HR per SD decrease, 1.57; 95% CI, 1.36-1.80), nonvertebral osteoporosis fractures (HR per SD decrease, 1.42; 95% CI, 1.23-1.65), and hip fractures (HR per SD decrease, 1.44; 95% CI, 1.18-1.76). The inverse relation between serum E2 and fracture risk was nonlinear with a strong relation <16 pg/ml for E2 and 0.3 pg/ml for fE2. In conclusion, older Swedish men with low serum E2 and high SHBG levels have an increased risk of fractures.
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49. |
- Mellström, Dan, 1945, et al.
(författare)
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Older men with low serum estradiol and high serum SHBG have an increased risk of fractures
- 2008
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Ingår i: J Bone Miner Res. - : Wiley. - 1523-4681 .- 0884-0431. ; 23:10, s. 1552-60
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures constitute a major health concern not only in women but also in men. To study the predictive role of serum sex steroids for fracture risk in men, serum sex steroids were analyzed by the specific gas chromatography-mass spectrometry technique at baseline in older men (n = 2639; mean, 75 yr of age) of the prospective population-based MrOS Sweden cohort. Fractures occurring after baseline were validated (average follow-up of 3.3 yr). The incidence for having at least one validated fracture after baseline was 20.9/1000 person-years. Estradiol (E2; hazard ratio [HR] per SD decrease, 1.34; 95% CI, 1.22-1.49), free estradiol (fE2; HR per SD decrease, 1.41; 95% CI, 1.28-1.55), testosterone (T; HR per SD decrease, 1.27; 95% CI, 1.16-1.39), and free testosterone (fT; HR per SD decrease, 1.32; 95% CI, 1.21-1.44) were all inversely, whereas sex hormone-binding globulin (SHBG; HR per SD increase, 1.41; 95% CI, 1.22-1.63) was directly related to fracture risk. Multivariable proportional hazards regression models, adjusted for age, suggested that fE2 and SHBG (p
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50. |
- Nethander, Maria, 1980, et al.
(författare)
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An atlas of genetic determinants of forearm fracture.
- 2023
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Ingår i: Nature genetics. - : Springer Nature. - 1546-1718 .- 1061-4036. ; 55:11, s. 1820-1830
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporotic fracture is among the most common and costly of diseases. While reasonably heritable, its genetic determinants have remained elusive. Forearm fractures are the most common clinically recognized osteoporotic fractures with a relatively high heritability. To establish an atlas of the genetic determinants of forearm fractures, we performed genome-wide association analyses including 100,026 forearm fracture cases. We identified 43 loci, including 26 new fracture loci. Although most fracture loci associated with bone mineral density, we also identified loci that primarily regulate bone quality parameters. Functional studies of one such locus, at TAC4, revealed that Tac4-/- mice have reduced mechanical bone strength. The strongest forearm fracture signal, at WNT16, displayed remarkable bone-site-specificity with no association with hip fractures. Tall stature and low body mass index were identified as new causal risk factors for fractures. The insights from this atlas may improve fracture prediction and enable therapeutic development to prevent fractures.
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