| 1. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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A single early postnatal estradiol injection affects morphology and gene expression of the ovary and parametrial adipose tissue in adult female rats.
- 2010
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 122:1-3, s. 82-90
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Tidskriftsartikel (refereegranskat)abstract
- Events during early life can affect reproductive and metabolic functions in adulthood. We evaluated the programming effects of a single early postnatal estradiol injection (within 3h after birth) in female rats. We assessed ovarian and parametrial adipose tissue morphology, evaluated gene expression related to follicular development and adipose tissue metabolism, and developed a non-invasive volumetric estimation of parametrial adipose tissue by magnetic resonance imaging. Estradiol reduced ovarian weight, increased antral follicle size and number of atretic antral follicles, and decreased theca interna thickness in atretic antral follicles. Adult estradiol-injected rats also had malformed vaginal openings and lacked corpora lutea, confirming anovulation. Estradiol markedly reduced parametrial adipose tissue mass. Adipocyte size was unchanged, suggesting reduced adipocyte number. Parametrial adipose tissue lipoprotein lipase activity was increased. In ovaries, estradiol increased mRNA expression of adiponectin, complement component 3, estrogen receptor alpha, and glucose transporter 3 and 4; in parametrial adipose tissue, expression of complement component 3 was increased, expression of estrogen receptor alpha was decreased, and expression of leptin, lipoprotein lipase, and hormone-sensitive lipase was unaffected. These findings suggest that early postnatal estradiol exposure of female rats result in long-lasting effects on the ovary and parametrial adipose tissue at adult age.
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| 2. |
- Alexanderson, Camilla, 1978, et al.
(författare)
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Influence of having a male twin on body mass index and risk for dyslipidemia in middle-aged and old women.
- 2011
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 35, s. 1466-1469
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Tidskriftsartikel (refereegranskat)abstract
- Background:Animal experiments suggest that exposure to elevated levels of androgens during development by means of so-called hormonal programming causes metabolic aberrations at adulthood. An indirect strategy to address the possible importance of such an influence also in humans would be to study female dizygotic twins, presuming that those with a twin brother-due to diffusion of testosterone-have been exposed to higher androgen levels prenatally.Design:We have compared 8409 women with a male twin with 9166 women with a dizygotic female twin with respect to self-reported indices of anthropometry and metabolic aberrations at age 42 or older.Results:Body mass index (BMI), body weight and rate of dyslipidemia were moderately, but significantly, higher in women from opposite-sexed (OS) twin pairs; splitting for age revealed this difference to be present in those 60 years of age only.Conclusion:The results (i) support the notion that comparisons of women with a twin brother with women from same-sexed twin pairs may be used to shed light on possible long-term effects of interindividual variations in early androgen exposure, and (ii) suggest that the effects of early androgen exposure on metabolism previously observed in animal experiments are of relevance also for humans.International Journal of Obesity advance online publication, 8 March 2011; doi:10.1038/ijo.2011.18.
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| 3. |
- Alvehus, Malin, 1975-
(författare)
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Obesity-associated inflammation in adipose tissue
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Excess body fat, particularly in the visceral depot, is linked to increased mortality and morbidity, including the development of diseases such as type 2 diabetes, cardiovascular disease, and cancer. Chronic low-grade inflammation in adipose tissue may be a key mediator of obesity-associated diseases. Importantly, specific pro-inflammatory cytokines have been shown to influence adipose tissue function and could therefore be a link to metabolic disorders. Circulating cytokine levels may also be increased in obesity and metabolic diseases. However, although fat distribution and inflammation are clearly linked to metabolic disorders, inflammatory gene expression in the different abdominal adipose depots has not been investigated in detail. The menopausal transition is followed by a centralization of body fat and increased adiposity. Notably, inflammatory changes in fat during the menopausal transition have not been characterized. Finally, there is a lack of studies investigating the long-term effects of weight loss on low-grade inflammation. The aim of this thesis was to characterize differences between fat depots and investigate putative changes in low-grade inflammation in adipose tissue and circulation following menopause or weight loss. Materials & Methods: The expression of inflammation-related genes was investigated in abdominal adipose tissue depots obtained from women with varying adiposity, before and after menopause or weight loss induced by surgery or dietary intervention. Circulating cytokine levels were analyzed using immunoassays. Results: Visceral fat displayed a distinct and adverse inflammatory profile compared with subcutaneous adipose tissues, and the higher gene expression in visceral fat was associated with adiposity. Postmenopausal women exhibited a higher expression of pro-inflammatory genes than premenopausal women that associated with central fat accumulation. There was also a menopause-related increase in circulating cytokine levels in postmenopausal women. After surgery-induced weight loss, there was a dramatic reduction in inflammatory gene expression followed by increased insulin sensitivity. We observed no alterations in circulating cytokine levels. Long-term dietary intervention, associated with weight loss, had favorable effects on inflammation in both adipose tissue and serum. Conclusion: Fat accumulation is linked to low-grade inflammation in abdominal adipose tissue. The unique inflammatory pattern of visceral fat suggests a distinct role in adipose tissue inflammation that is aggravated with increasing adiposity. In postmenopausal women, the adverse adipose inflammatory profile was associated with central fat accumulation, while higher circulating cytokine levels correlated with menopausal state/age. Our data from severely obese women undergoing surgery-induced weight loss clearly supports a link between adipose inflammation and insulin resistance. The long-term beneficial effects of weight loss were also demonstrated by the improved inflammatory profile after dietary intervention. In summary, excess body fat is clearly linked to adipose tissue inflammation. Long-term weight loss is accompanied by improved metabolic profile and reduced low-grade inflammation in fat.
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| 4. |
- Andersson, Therése, 1978-
(författare)
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Estrogen and Glucocorticoid Metabolism
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cardiovascular disease (CVD) is the leading cause of death among women in Sweden. The risk of CVD increases rapidly after the menopause. A major contributing factor may be the redistribution of adipose tissue, from the peripheral to central depots, associated with menopause. This change in body composition is commonly attributed to declining estrogen levels but may also be affected by tissue-specific alterations in exposure to other steroid hormones, notably glucocorticoids – mainly cortisol in humans. Indeed, adipose tissue-specific overexpression of the glucocorticoid-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) induces central obesity, insulin resistance and hypertension in mice. Interestingly, estrogen may regulate this enzyme. The aim of this thesis was to investigate putative links between estrogen and glucocorticoid activation by 11βHSD1. Materials and Methods: 11βHSD1 expression and/or activity in adipose tissue and liver, and adipose estrogen receptor α and β (ERα and ERβ) gene expression, were investigated in lean pre- and postmenopausal women and ovariectomized rodents with and without estrogen supplementation. In lean women measures of 11βHSD1 were correlated to risk markers for CVD. The association between adipose 11βHSD1 and ER mRNA expression was investigated in both lean women and rats and in an additional cohort of obese premenopausal women. In vitro experiments with adipocyte cell lines were used to explore possible pathways for estrogen regulation of 11βHSD1. Results: Subcutaneous adipose tissue transcript levels and hepatic activity of 11βHSD1 were higher in postmenopausal vs. premenopausal women. In rodents, estrogen treatment to ovariectomized rats decreased visceral adipose tissue 11βHSD1, resulting in a shift towards higher subcutaneous (vs. visceral) 11βHSD1 mRNA expression/activity. Increased adipose and hepatic 11βHSD1 were associated with increased blood pressure and a disadvantageous blood lipid profile in humans. We found significant positive associations between 11βHSD1 and ERβ transcript levels in adipose tissue. The in vitro experiments showed upregulation of 11βHSD1 mRNA expression and activity with estrogen or ERβ-agonist treatment at low (corresponding to physiological) concentrations. Conclusions: Our studies show for the first time increased local tissue glucocorticoid activation with menopause/age in women. This may contribute to an increased risk of CVD. Estrogen treatment in rodents induces a shift in 11βHSD1 activity towards the subcutaneous adipose tissue depots, which may direct fat accumulation to this metabolically “safer” depot. The in vitro studies suggest that low-dose estrogen treatment upregulates 11βHSD1 via ERβ. In summary, estrogen - glucocorticoid metabolism interactions may be key in the development of menopause-related metabolic dysfunction and in part mediate the beneficial effects of postmenopausal estrogen treatment on body fat distribution.
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| 5. |
- Bosaeus, Marja, et al.
(författare)
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Accuracy of quantitative magnetic resonance and eight-electrode bioelectrical impedance analysis in normal weight and obese women.
- 2014
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Ingår i: Clinical Nutrition. - : Elsevier BV. - 0261-5614. ; 33:3, s. 471-477
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Tidskriftsartikel (refereegranskat)abstract
- Background & aims Quantitative magnetic resonance (QMR) has previously been shown to both overestimate and underestimate average fat mass (FM) in humans. Eight-electrode bioelectrical impedance analysis (BIA) has previously been found biased as well as successfully validated. We report cross-sectional accuracy of QMR and eight-electrode BIA evaluated with air displacement plethysmography (ADP) as reference method. Methods Fat mass and fat free mass (FFM) by QMR and eight-electrode BIA were evaluated against ADP as reference in 38 normal weight and 30 obese women. Total body water estimates by QMR and eight-electrode BIA were compared. Results Fat mass was overestimated by QMR (1 ± 2 kg, p < 0.001) and was underestimated by eight-electrode BIA (1 ± 3 kg, p = 0.03, Bonferroni adjusted p = 0.29) in normal weight women. Fat mass was underestimated by both QMR (2 ± 2 kg, p < 0.001) and eight-electrode BIA (9 ± 3 kg, p < 0.001) in obese women. Fat free mass biases were of similar magnitude but in opposite direction to FM biases. Total body water estimates were larger by eight-electrode BIA compared to QMR (1–10 kg). Conclusions Fat mass and FFM by QMR were both biased but in opposite directions in both normal weight and obese women. Eight-electrode BIA FM and FFM estimates were imprecise and biased in obese women. Thus, QMR is more precise and more accurate than eight-electrode BIA for estimating body composition in women, but is not accurate enough to be used for individual single assessment of body composition.
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| 6. |
- Brackmann, Christian, 1973, et al.
(författare)
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Nonlinear microscopy of lipid storage and fibrosis in muscle and liver tissues of mice fed high-fat diets
- 2010
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Ingår i: Journal of Biomedical Optics. - : SPIE-Intl Soc Optical Eng. - 1083-3668 .- 1560-2281. ; 15:6
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Tidskriftsartikel (refereegranskat)abstract
- Hallmarks of high-fat Western diet intake, such as excessive lipid accumulation in skeletal muscle and liver as well as liver fibrosis, are investigated in tissues from mice using nonlinear microscopy, second harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS), supported by conventional analysis methods. Two aspects are presented; intake of standard chow versus Western diet, and a comparison between two high-fat Western diets of different polyunsaturated lipid content. CARS microscopy images of intramyocellular lipid droplets in muscle tissue show an increased amount for Western diet compared to standard diet samples. Even stronger diet impact is found for liver samples, where combined CARS and SHG microscopy visualize clear differences in lipid content and collagen fiber development, the latter indicating nonalcoholic fatty liver disease (NAFLD) and steatohepatitis induced at a relatively early stage for Western diet. Characteristic for NAFLD, the fibrous tissue-containing lipids accumulate in larger structures. This is also observed in CARS images of liver samples from two Western-type diets of different polyunsaturated lipid contents. In summary, nonlinear microscopy has strong potential (further promoted by technical advances toward clinical use) for detection and characterization of steatohepatitis already in its early stages.
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| 7. |
- Bromander, Sara, et al.
(författare)
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Cerebrospinal fluid insulin during non-neurological surgery.
- 2010
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Ingår i: J Neural Transm (Vienna, Austria:1996). - : Springer Science and Business Media LLC. - 1435-1463 .- 0300-9564. ; 20, s. 328-329
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Tidskriftsartikel (refereegranskat)abstract
- Insulin plays an important metabolic and transmitter role in the central nervous system, but few studies have investigated the relationship between central and peripheral insulin concentrations. 35 patients undergoing knee surgery had cerebrospinal fluid (CSF) samples drawn before, 3 h after, and in the morning following surgery. Serum insulin concentrations increased after surgery and CSF insulin concentrations changed in the same direction with far smaller amplitude. These results indicate that the blood-brain barrier protects the brain from stress-induced peripheral hormonal fluctuations.
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| 9. |
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| 10. |
- Gabrielsson, Britt, 1957, et al.
(författare)
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Dietary herring improves plasma lipid profiles and reduces atherosclerosis in obese low-density lipoprotein receptor-deficient mice
- 2012
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Ingår i: International Journal of Molecular Medicine. - : Spandidos Publications. - 1107-3756 .- 1791-244X. ; 29:3, s. 331-37
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Tidskriftsartikel (refereegranskat)abstract
- Diet is a significant modifiable risk factor for cardiovascular disease and high fish intake has been associated with vascular health in population studies. However, intervention studies have been inconclusive. In this study, male low-density lipoprotein receptor-deficient mice were given 16-week high fat/high sucrose diets, supplemented with either minced herring fillets or minced beef. The diets were matched in total fat and cholesterol content; taurine content and fatty acid composition was analysed. Body weights were recorded throughout the study; plasma lipids were analysed at week 8 and 16. Body composition and adipocyte size were evaluated at study end. Atherosclerosis was evaluated at week 12 (ultrasound) and at termination (en face histology). Herring-fed mice had a higher proportion of long-chain n-3 polyunsaturated fatty acids in the hepatic triacylglycerides (TAG) and phospholipid fractions. The herring-fed mice had increased body weight (P=0.007), and reduced epididymal adipocyte size (P=0.009), despite similar food intake and body composition as the beef-fed mice. The herring-fed mice had lower plasma TAG and very-low-density lipoprotein (VLDL)-cholesterol concentrations throughout the study (TAG; P=0.0012 and 0.004, VLDL-cholesterol; P=0.006 and 0.041, week 8 and 16, respectively). At week 16, the herring-fed had higher plasma concentrations of HDL-cholesterol (P=0.004) and less atherosclerotic lesions in the aortic arch (P=0.007) compared with the beef-fed mice. In conclusion, dietary herring in comparison to beef markedly improved vascular health in this mouse model, suggesting that herring provides an added value beyond its content of macronutrients.
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