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- Schive, Simen W., et al.
(författare)
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Human Adipose-Derived Mesenchymal Stem Cells Respond to Short-Term Hypoxia by Secreting Factors Beneficial for Human Islets In Vitro and Potentiate Antidiabetic Effect In Vivo
- 2017
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Ingår i: Cell Medicine. - 2155-1790. ; 9:3, s. 103-116
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Tidskriftsartikel (refereegranskat)abstract
- Adipose-derived mesenchymal stem cells (ASCs) release factors beneficial for islets in vitro and protect against hyperglycemia in rodent models of diabetes. Oxygen tension has been shown to induce metabolic changes and alter ASCs' release of soluble factors. The effects of hypoxia on the antidiabetic properties of ASCs have not been explored. To investigate this, we incubated human ASCs for 48 h in 21% (normoxia) or 1% O-2 (hypoxia) and compared viability, cell growth, surface markers, differentiation capability, and soluble factors in the conditioned media (CM). Human islets were exposed to CM from ASCs incubated in either normoxia or hypoxia, and islet function and apoptosis after culture with or without proinflammatory cytokines were measured. To test hypoxic preconditioned ASCs' islet protective effects in vivo, ASCs were incubated for 48 h in normoxia or hypoxia before being injected into Balb/c Rag 1(-/-) immunodeficient mice with streptozotocin-induced insulitis. Progression of diabetes and insulin content of pancreas were measured. We found that incubation in hypoxia was well tolerated by ASCs and that levels of VEGF-A, FGF-2, and bNGF were elevated in CM from ASCs incubated in hypoxia compared to normoxia. while levels of HGF, IL-8, and CXCL1 were reduced. CM from ASCs incubated in hypoxia significantly improved human islet function and reduced apoptosis after culture, and reduced cytokine-induced apoptosis. In our mouse model, pancreas insulin content was higher in both groups receiving ASCs compared to control, but the mice receiving preconditioned ASCs had lower random and fasting blood glucose, as well as improved oral glucose tolerance compared to untreated mice. In conclusion, our in vitro results indicate that the islet protective potential of ASCs improves in hypoxia, and we give insight into factors involved in this. Finally we show that hypoxic preconditioning potentiates ASCs' anti-diabetic effect in vivo.
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| 2. |
- Utjés, Deborah, et al.
(författare)
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2-cm versus 4-cm surgical excision margins for primary cutaneous melanoma thicker than 2 mm : long-term follow-up of a multicentre, randomised trial
- 2019
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Ingår i: The Lancet. - 0140-6736. ; 394:10197, s. 471-477
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Tidskriftsartikel (refereegranskat)abstract
- Background: The optimal surgical excision margins are uncertain for patients with thick (>2 mm) localised cutaneous melanomas. In our previous report of this multicentre, randomised controlled trial, with a median follow-up of 6·7 years, we showed that a narrow excision margin (2 cm vs 4 cm) did not affect melanoma-specific nor overall survival. Here, we present extended follow-up of this cohort. Methods: In this open-label, multicentre randomised controlled trial, we recruited patients from 53 hospitals in Sweden, Denmark, Estonia, and Norway. We enrolled clinically staged patients aged 75 years or younger diagnosed with localised cutaneous melanoma thicker than 2 mm, and with primary site on the trunk or upper or lower extremities. Patients were randomly allocated (1:1) to treatment either with a 2-cm or a 4-cm excision margin. A physician enrolled the patients after histological confirmation of a cutaneous melanoma thicker than 2 mm. Some patients were enrolled by a physician acting as responsible for clinical care and as a trial investigator (follow-up, data collection, and manuscript writing). In other cases physicians not involved in running the trial enrolled patients. Randomisation was done by telephone call to a randomisation office, by sealed envelope, or by computer generated lists using permuted blocks. Patients were stratified according to geographical region. No part of the trial was masked. The primary outcome in this extended follow-up study was overall survival and the co-primary outcome was melanoma-specific survival. All analyses were done on an intention-to-treat basis. The study is registered with ClinicalTrials.gov, number NCT03638492. Findings: Between Jan 22, 1992, and May 19, 2004, 936 clinically staged patients were recruited and randomly assigned to a 4-cm excision margin (n=465) or a 2-cm excision margin (n=471). At a median overall follow-up of 19·6 years (235 months, IQR 200–260), 621 deaths were reported—304 (49%) in the 2-cm group and 317 (51%) in the 4-cm group (unadjusted HR 0·98, 95% CI 0·83–1·14; p=0·75). 397 deaths were attributed to cutaneous melanoma—192 (48%) in the 2-cm excision margin group and 205 (52%) in the 4-cm excision margin group (unadjusted HR 0·95, 95% CI 0·78–1·16, p=0·61). Interpretation: A 2-cm excision margin was safe for patients with thick (>2 mm) localised cutaneous melanoma at a follow-up of median 19·6 years. These findings support the use of 2-cm excision margins in current clinical practice. Funding: The Swedish Cancer Society, Stockholm Cancer Society, the Swedish Society for Medical Research, Radiumhemmet Research funds, Stockholm County Council, Wallström funds.
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