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- Enerbäck, Sven, 1958
(författare)
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Brown adipose tissue in humans
- 2010
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Ingår i: INTERNATIONAL JOURNAL OF OBESITY. - 0307-0565. ; 34
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Forskningsöversikt (refereegranskat)abstract
- Obesity is endemic in many regions of the world and a forerunner of several serious and sometimes fatal diseases such as ischemic heart disease, stroke, kidney failure and neoplasia. Although we know its origin—it results when energy intake exceeds energy expenditure—at present, the only proven therapy is bariatric surgery. This is a major abdominal procedure that, for reasons that are largely unknown (it cannot be explained solely by a reduction in ventricular volume), significantly reduces energy intake, but because of cost and limited availability, it will most likely be reserved for only a small fraction of those who stand to gain from effective antiobesity treatment. Clearly, alternative ways to treat obesity are needed. Another way to combat excessive accumulation of white adipose tissue would be to increase energy expenditure. Rodents, hibernators and human infants all have a specialized tissue—brown adipose tissue (BAT)—with the unique capacity to regulate energy expenditure by a process called adaptive thermogenesis. This process depends on the expression of uncoupling protein-1 (UCP1), which is a unique marker for BAT. UCP1 is an inner mitochondrial membrane protein that short circuits the mitochondrial proton gradient, so that oxygen consumption is no longer coupled to adenosine triphosphate synthesis. As a consequence, heat is generated. Mice lacking ucp-1 are severely compromised in their ability to maintain normal body temperature when acutely exposed to cold and they are also prone to become obese. We have shown that, in mice, BAT protects against diet-induced obesity, insulin resistance and type 2 diabetes. This is based on prevention of excessive accumulation of triglyceride in non-adipose tissues such as muscle and liver. Ectopic triglyceride storage at these locations is associated with initiation of insulin resistance and, ultimately, development of type 2 diabetes.
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| 2. |
- Enerbäck, Sven, 1958
(författare)
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Human brown adipose tissue.
- 2010
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Ingår i: Cell metabolism. - : Elsevier BV. - 1932-7420 .- 1550-4131. ; 11:4, s. 248-52
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Tidskriftsartikel (refereegranskat)abstract
- The BAT organ is unique in that it has evolved to safely dissipate large amounts of chemical energy--a quality that might be harnessed to help humans deal with a dangerously hypercaloric environment and still remain in good health.
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| 3. |
- Karlsson, Mona, et al.
(författare)
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Pilot Study of Sentinel-Node-Based Adoptive Immunotherapy in Advanced Colorectal Cancer.
- 2010
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Ingår i: Annals of surgical oncology. - : Springer Science and Business Media LLC. - 1534-4681 .- 1068-9265. ; 17:7, s. 1747-1757
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite optimal surgical treatment and modern adjuvant therapies, 50% of patients diagnosed with colorectal cancer die within 5 years. Immunotherapy offers an appealing complement to traditional chemotherapy, with possible long-term protection against tumor recurrences through immunological memory. We have conducted a pilot study of a novel adoptive immunotherapy, using autologous, in vitro expanded lymphocytes isolated from the tumor-draining sentinel lymph node. STUDY DESIGN: Sentinel nodes were recovered from 16 patients with disseminated or locally advanced, high-risk colorectal cancer. Single-cell suspensions of sentinel-node-acquired lymphocytes were clonally expanded in vitro in the presence of autologous tumor extract and returned as a transfusion. Patients were followed with clinical and radiological evaluations. Long-term survival was compared with traditionally treated controls. RESULTS: Sentinel-node-acquired CD4(+) Th1-lymphocytes could be clonally expanded in vitro and safely administered to all 16 patients without side-effects. In four out of nine stage IV patients, complete tumor regression occurred. Median survival time in the stage IV patients (n = 9) was 2.6 years, as compared with 0.8 years in conventionally treated controls. A dose-dependent effect with regards to reduced tumor burden and long-term survival was observed. CONCLUSION: Sentinel-node-based adoptive immunotherapy is feasible; the method has shown no apparent side-effects and appears to convey therapeutic antitumor effects. Further studies are justified to determine its efficacy and precise role in the treatment of colorectal cancer.
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| 4. |
- Lidell, Martin, 1970, et al.
(författare)
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Brown adipose tissue-a new role in humans?
- 2010
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Ingår i: Nature reviews. Endocrinology. - : Springer Science and Business Media LLC. - 1759-5037 .- 1759-5029. ; 6, s. 319-325
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Forskningsöversikt (refereegranskat)abstract
- New targets for pharmacological interventions are of great importance to combat the epidemic of obesity. Brown adipose tissue could potentially represent one such target. Unlike white adipose tissue, brown adipose tissue has the ability to dissipate energy by producing heat rather than storing it as triglycerides. In small mammals, the presence of active brown adipose tissue is pivotal for the maintenance of body temperature and possibly to protect against the detrimental effects of surplus energy intake. Animal studies have shown that expansion and/or activation of brown adipose tissue counteracts diet-induced weight gain and related disorders such as type 2 diabetes mellitus. Several independent studies have now confirmed the presence of functional brown adipose tissue in adult humans, for whom this tissue is probably metabolically beneficial given its association with both low BMI and low total adipose tissue content. Over the past few years, knowledge of the transcriptional control and development of brown adipose tissue has increased substantially. Thus, several possible targets that may be useful for the expansion and/or activation of this tissue by pharmacological means have been identified. Whether or not brown adipose tissue will be useful in the battle against obesity remains to be seen. However, this possibility is certainly well worth exploring.
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| 5. |
- Westergren, Rickard, 1974, et al.
(författare)
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Overexpression of Foxf2 in adipose tissue is associated with lower levels of IRS1 and decreased glucose uptake in vivo.
- 2010
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 298:3
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Tidskriftsartikel (refereegranskat)abstract
- Many members of the forkhead genes family of transcription factors have been implicated as important regulators of metabolism, in particular, glucose homeostasis, e.g., Foxo1, Foxa3, and Foxc2. The purpose of this study was to exploit the possibility that yet unknown members of this gene family play a role in regulating glucose tolerance in adipocytes. We identified Foxf2 in a screen for adipose-expressed forkhead genes. In vivo overexpression of Foxf2 in an adipose tissue-restricted fashion demonstrated that such mice display a significantly induced insulin secretion in response to an intravenous glucose load compared with wild-type littermates. In response to increased Foxf2 expression, insulin receptor substrate 1 (IRS1) mRNA and protein levels are significantly downregulated in adipocytes; however, the ratio of serine vs. tyrosine phosphorylation of IRS1 seems to remain unaffected. Furthermore, adipocytes overexpressing Foxf2 have a significantly lower insulin-mediated glucose uptake compared with wild-type adipocytes. These findings argue that Foxf2 is a previously unrecognized regulator of cellular and systemic whole body glucose tolerance, at least in part, due to lower levels of IRS1. Foxf2 and its downstream target genes can provide new insights with regard to identification of novel therapeutic targets.
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