| 1. |
|
|
| 2. |
- de-Wahl Granelli, Anne, 1970, et al.
(author)
-
Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns.
- 2009
-
In: BMJ (Clinical research ed.). - 1468-5833. ; 338
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: To evaluate the use of pulse oximetry to screen for early detection of life threatening congenital heart disease. DESIGN: Prospective screening study with a new generation pulse oximeter before discharge from well baby nurseries in West Götaland. Cohort study comparing the detection rate of duct dependent circulation in West Götaland with that in other regions not using pulse oximetry screening. Deaths at home with undetected duct dependent circulation were included. SETTING: All 5 maternity units in West Götaland and the supraregional referral centre for neonatal cardiac surgery. PARTICIPANTS: 39,821 screened babies born between 1 July 2004 and 31 March 2007. Total duct dependent circulation cohorts: West Götaland n=60, other referring regions n=100. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values, and likelihood ratio for pulse oximetry screening and for neonatal physical examination alone. RESULTS: In West Götaland 29 babies in well baby nurseries had duct dependent circulation undetected before neonatal discharge examination. In 13 cases, pulse oximetry showed oxygen saturations
|
|
| 3. |
|
|
| 4. |
- Haros, Monica, et al.
(author)
-
Phytate degradation by human gut isolated Bifidobacterium pseudocatenulatum ATCC27919 and its probiotic potential
- 2009
-
In: International Journal of Food Microbiology. - : Elsevier BV. - 1879-3460 .- 0168-1605. ; 135:1, s. 7-14
-
Journal article (peer-reviewed)abstract
- The growing awareness of the relationship between diet and health has led to an increasing demand for food products that support health above and beyond providing basic nutrition. Probiotics are live organisms present in foods, which yield health benefits related to their interactions with the gastrointestinal tract. Phytases are a subgroup of phosphatases that catalyse the desphosphorylation of phytate, which reduces its negative impact on mineral bioavailability, and generates lower inositol phosphates. The aims of this investigation were to (i) study the ability of the probiotic candidate Bifidobacterium pseudocatenulatum to degrade phytate in synthetic medium, to (ii) identify the lower inositol phosphates generated, to (iii) study its survival under conditions mimicking gastrointestinal passage and finally to (iv) assess adhesion of the bacteria to Caco-2 cells. The first steps of InsP(6) degradation by B. pseudocatenulatum phytate-degrading enzyme/s were preferentially initiated at the DL-6-position and 5-position of the myo-inositol ring. It suggests that the main InsP(6) degradation pathway by B. pseudocatenulatum by sequential removal of phosphate groups was D/L-Ins(1,2,3,4,5)P(5) or D/L-Ins(1,2,3,4,6)P(5); D/L-Ins(1,2,3,4)P(4); to finally Ins(1,2,3)P(3) and D/L-Ins(1,2,4)P(3)/D/L-Ins(1,3,4)P(3). This human strain also showed a notable tolerance to bile as well as a selective adhesion capacity (adhesion to control surfaces was zero), to human intestinal Caco-2 cells comparable to the commercial probiotic B. lactis. The phytate-degrading activity constitutes a novel metabolic trait which could contribute to the improvement of mineral absorption in the intestine as a nutritional probiotic feature with potential trophic effect in human gut.
|
|
| 5. |
- Johansson, Åsa, et al.
(author)
-
Endothelial cell signalling supports pancreatic beta cellfunction in the rat
- 2009
-
In: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 52:11, s. 2385-2394
-
Journal article (peer-reviewed)abstract
- Aims/hypothesis The proximity of endothelial cells andbeta cells in islets by necessity means that they are exposedto each other’s products. Whereas islet endothelial cellsrequire signals from beta cells to function properly,endothelin-1, thrombospondin-1 and laminins, amongothers, have been identified as endothelial-derived molecules,although their full effects on beta cells have not beenexplored. We tested the hypothesis that islet endothelialderivedproducts affect beta cell function.Methods Endothelial cells from rat islets were proliferatedand purified. Endothelium-conditioned culture medium(ECCM) was obtained by maintaining the endothelial cellsin culture medium. Islet function was evaluated followingexposure of cultured islets to standard culture medium orECCM. Changes in mRNA levels for key beta cellmetabolic enzymes were also measured in islets afterECCM exposure.Results Glucose-stimulated insulin release and islet insulincontent were markedly enhanced by exposure to ECCM.This was at least partly explained by improved mitochondrialfunction, as assessed by glucose oxidation and anupregulation of the mitochondrial gene for glycerol-3-phosphate dehydrogenase (mGpdh [also known as Gpd2]),combined with upregulation of the rate-limiting enzyme inthe glycolysis, glucokinase, in the islets. The intracellulardegradation of insulin was also decreased in the islets. Isletendothelial cells produced laminins, and the positive effectsof islet endothelial cells were prevented by addition of aneutralising antibody to the β1-chain of laminin. Additionof exogenous laminin stimulated islet function.Conclusions/interpretation This study provides proof ofprinciple that endothelial cells can affect the function of betacells in their vicinity and that this is at least partially mediatedby laminins.
|
|
| 6. |
- Olerud, Johan, et al.
(author)
-
Neural crest stem cells increase beta cell proliferation and improve islet function in co-transplanted murine pancreatic islets
- 2009
-
In: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 52:12, s. 2594-2601
-
Journal article (peer-reviewed)abstract
- AIMS/HYPOTHESIS: Long-term graft survival after islet transplantation to patientswith type 1 diabetes is insufficient, necessitating the development of newstrategies to enhance transplant viability. Here we investigated whetherco-transplantation of neural crest stem cells (NCSCs) with islets improves islet survival and function in normoglycaemic and diabetic mice. METHODS: Islets alone or together with NCSCs were transplanted under the kidney capsule tonormoglycaemic or alloxan-induced diabetic mice. Grafts were analysed for size,proliferation, apoptosis and insulin release. In diabetic recipients bloodglucose levels were examined before and after graft removal. RESULTS: In mixedtransplants NCSCs actively migrated and extensively associated withco-transplanted pancreatic islets. Proliferation of beta cells was markedlyincreased and transplants displayed improved insulin release in normoglycaemicmice compared with those receiving islet-alone transplants. Mixed grafts survivedsuccessfully and partially restored normoglycaemia in alloxan-induced diabeticmice. CONCLUSIONS/INTERPRETATION: Co-grafting of NCSCs with pancreatic isletsimproved insulin release in mixed transplants and enhanced beta cellproliferation, resulting in increased beta cell mass. This co-transplantationmodel offers an opportunity to restore neural-islet interactions and improveislet functions after transplantation.
|
|
| 7. |
- Sandberg, Monica, et al.
(author)
-
Intracellular degradation of insulin and crinophagy are maintained by nitric oxide and cyclooxygenase 2 activity in isolated pancreatic islets
- 2006
-
In: Biology of the Cell. ; 98:5, s. 307-315
-
Journal article (peer-reviewed)abstract
- BACKGROUND INFORMATION: Pancreatic beta-cells require an optimal insulin content to allow instantaneous secretion of insulin. This is maintained by insulin biosynthesis and intracellular degradation of insulin. Degradation may be effected by crinophagy, i.e. the fusion of secretory granules with lysosomes. IL-1beta (interleukin 1beta) induces distinct changes of beta-cell lysosomes. To study the mechanisms for intracellular insulin degradation and crinophagy, isolated mouse pancreatic islets were exposed to IL-1beta and known pathways for IL-1beta actions were blocked. Intracellular insulin degradation was determined by following the fate of radioactively labelled insulin. Crinophagy was studied by ultrastructural analysis. The effects of blocking pathways for IL-1beta were monitored by measurements of nitrite and PGE(2) (prostaglandin E(2)). RESULTS: IL-1beta caused an enhancement of islet intracellular insulin degradation and an increase in the lysosomal incorporation of beta-cell secretory granules. The effects of IL-1beta were abolished by aminoguanidine, a selective inhibitor of inducible NOS (nitric oxide synthase), or by rofecoxib, a specific inhibitor of COX-2 (cyclo-oxygenase 2). In the absence of IL-1beta, nitroarginine, which is a selective inhibitor of constitutive NOS, caused a decrease in intracellular degradation of insulin in parallel with a decreased production of NO and PGE(2) by the islets. CONCLUSIONS: The correlation between the enhanced intracellular insulin degradation and lysosomal changes caused by IL-1beta suggests that insulin degradation may be effected by crinophagy. Under physiological conditions, significant beta-cell degradation of insulin may depend on the activity of COX-2, possibly stimulated by endogenous NO.
|
|
| 8. |
|
|
| 9. |
- Sandberg, Monica, 1964-
(author)
-
Intracellular Degradation of Insulin in Pancreatic Islets
- 2007
-
Doctoral thesis (other academic/artistic)abstract
- There is a substantial intracellular degradation of insulin in pancreatic islets. This may be a physiological process, which, in correspondence with biosynthesis and secretion of insulin, would optimize the secretory granule content of the pancreatic β-cell. Insulin degradation may be effected by crinophagy, a process where secretory granules fuse with lysosomes. The general aim of this thesis was to investigate possible control mechanisms for intracellular degradation of insulin and crinophagy in isolated pancreatic islets. In islets incubated at low glucose concentrations there was an insulin degradation and this correlated well with the ultrastructural findings, where a lot of secondary lysosomes containing secretory granules were found. In islets incubated at a high glucose concentration there was no insulin degradation and the ultrastructure revealed only a few insulin granules and mostly primary lysosomes, indicating that there was no crinophagic activity. With interleukin-1β the islet insulin degradation, nitric oxide production and prostaglandin E2 production were increased. The effects were abolished either by inhibition of inducible nitric oxide synthetase by aminoguanidine, or by the specific cyclooxygenase-2 inhibitor rofecoxib. These findings indicate that there is a connection between the intracellular degradation of insulin, production of nitric oxide and cyclooxygenase-2 activation. The nitric oxide donor DETA/NO enhanced the intracellular degradation of insulin and cyclooxygenase-2 activation with subsequent production of prostaglandin E2, suggesting that the link between nitric oxide and insulin degradation may be a cyclooxygenase-2 activation and subsequent prostaglandin E2 production. With corticosterone added to islet incubations the insulin degradation decreased, which paralleled with a diminished crinophagy and formation of prostaglandin E2. With progesterone there was instead an increase in insulin degradation and crinophagy and an increased formation of prostaglandin E2. These effects were abolished by mifepristone, an inhibitor of intracellular corticosterone and progesterone receptors. This suggests that the effects from these steroids are exerted via a change in islet gene expression and cyclooxygenase-2 activation. It was also concluded that phospholipase A2 is involved in insulin degradation and that the isoform secretory phospholipase A2 may be involved in triggering this process. This suggests that cyclooxygenase-2 activation with a subsequent production of prostaglandin E2 may provide a control mechanism for intracellular degradation of insulin and crinophagy in pancreatic islets.
|
|
| 10. |
- Sandberg, Monica, et al.
(author)
-
Steroid effects on intracellular degradation of insulin and crinophagy in isolated pancreatic islets
- 2007
-
In: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207 .- 1872-8057. ; 277:1-2, s. 35-41
-
Journal article (peer-reviewed)abstract
- Under physiological conditions substantial amounts of hormone may be degraded within endocrine cells by a crinophagic process comprising fusions of secretory granules with lysosomes. Glucocorticoids may stabilise and progesterone destabilise lysosomal membranes. The effects of corticosterone and progesterone on intracellular degradation of insulin and crinophagy were determined in pancreatic β-cells, and possible pathways mediating these effects were evaluated. Pancreatic islets were isolated from mice, intracellular degradation of insulin was measured by a pulse-chase method, and crinophagy was studied by electron microscopy. The islets were exposed to 3.3, 5.5 or 28 mM glucose with or without corticosterone, progesterone or the receptor ligands A-224817.0 and WAY-161358. Mifepristone was used to block steroid receptors and indomethacin to inhibit prostaglandin synthesis. Corticosterone caused a concentration-dependent decrease of insulin degradation at the lower glucose concentrations. Progesterone effected a concentration-dependent stimulation of insulin degradation. These results were paralleled with changes of the crinophagic activity in the β-cells. Corticosterone decreased and progesterone increased islet production of prostaglandin E2. Mifepristone abolished the steroid actions on insulin degradation and prostaglandin production. The effects of corticosterone were mimicked by the selective glucocorticoid receptor modulator A-224817.0, but in contrast to progesterone, the selective progesterone receptor agonist WAY-161358 had no effect on insulin degradation or prostaglandin production. Inhibition of cyclooxygenase blocked insulin degradation. The findings indicate that both corticosterone and progesterone could affect intracellular insulin degradation and crinophagy solely via the glucocorticoid receptor, and that prostaglandins may have a regulatory role in intracellular turnover of secretory material in pancreatic islet β-cells.
|
|
