| 1. |
- Birgisson, Hakon, et al.
(författare)
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A new thermostable alpha-L-arabinofuranosidase from a novel thermophilic bacterium
- 2004
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Ingår i: Biotechnology Letters. - 1573-6776. ; 26:17, s. 1347-1351
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Tidskriftsartikel (refereegranskat)abstract
- An alpha-L-arabinofuranosidase gene was identified in a sequenced genome of a novel thermophilic bacterium, which belongs to the recently described phylum of Thermomicrobia. Amino acid sequence comparison of the enzyme (designated AraF) revealed similarity to glycoside hydrolases of family 51. The gene was cloned into Escherichia coli and its recombinant product expressed and purified. The enzyme appeared to be a hexamer. AraF was optimally active at 70degreesC (over 10 min) and pH 6 having 92% residual activity after 1 h at 70degreesC. AraF had a K-m value of 0.6 rum and V-max value of 122 U mg(-1) on p-nitrophenyl-alpha-L-arabinofuranoside. AraF was almost equally active on branched arabinan and debranched arabinan, properties not previously found in alpha-L-arabinofuranosidases in GH family 51.
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| 2. |
- Bloch, K, et al.
(författare)
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Functional activity of insulinoma cells (INS-1E) and pancreatic islets cultured in agarose cryogel sponges
- 2005
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Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 75A:4, s. 802-809
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Tidskriftsartikel (refereegranskat)abstract
- Here, we describe the preparation, structure, and properties of cryogel sponges, which represent a new type of macroporous biomaterial for tissue engineering. Cryogels were produced through freeze-thawing techniques, either from agarose alone or from agarose with grafted gelatin. The aim of this study was to evaluate agarose cryogel sponges as scaffolds for Culturing both isolated pancreatic islets and insulinoma cells (INS-IE). In order to evaluate the effect of cell entrapment in artificial scaffolds, cell function reflected by insulin secretion and content was studied in cells cultivated for a 2-week period either in Culture plastic plates or in cryogel sponge disks. Our results show that tumor-derived INS-1E cells grown either on plastic or on cryogels do not differ in their proliferation, morphology, insulin release, and intracellular insulin content. However, isolated pancreatic islets cultivated on cryogels sponge show 15-fold higher basal insulin secretion at 3.0 mM glucose than islets cultivated on plastic plates and fail to respond to stimulation with 16.7 mM glucose. In addition, these islets have about 2-fold lower insulin content compared to those grown in plastic plates. It is possible that the cell dysfunction noted in these in vitro experiments is due to the effect of the limited oxygen supply to the islets cultivated in cryogel sponge. Further in vivo Studies are needed to clarify the nature of such an observation since according to previous reports, agarose and gelatin induce new vessel formation supporting enhanced oxygen supply. (c) 2005 Wiley Periodicals, Inc.
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| 3. |
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| 4. |
- Språngberg, A, et al.
(författare)
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SBU. Godartad prostataförstoring med avflödeshinder. En systematisk litteraturöversikt : Godartad prostataförstoring med avflödeshinder
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Slutsatser Godartad prostataförstoring (benign prostatahyperplasi, BPH) är ett vanligt tillstånd som med stigande ålder drabbar i princip alla män. En del av dessa män får urineringsproblem och cirka 4 500 opereras varje år för en förstorad prostata. Många med lindrigare besvär behandlas med läkemedel eller behöver ingen behandling alls. Avflödeshinder kan obehandlat ge allvarlig urinretention som skadar njurarna, och en urinstämma kan vara livshotande. För att avgränsa den grupp av män där problemen med urineringen beror på en förstorad prostata används ett tiotal olika diagnostiska metoder. När det gäller behandling finns det flera olika kirurgiska metoder, varav några är väl etablerade och andra av mer experimentell karaktär. Under 1990-talet har också flera läkemedel introducerats. SBU har därför bedömt att det funnits ett behov av att göra en systematisk genomgång av den vetenskapliga grunden för dessa olika metoder. Nedan följer de viktigaste slutsatserna av arbetet.
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| 5. |
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| 6. |
- Anwaar, I., et al.
(författare)
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Increased plasma endothelin-1 and intraplatelet cyclic guanosine monophosphate in men with disturbed glucose metabolism
- 2000
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Ingår i: Diabetes Research and Clinical Practice. - 0168-8227. ; 50:2, s. 127-136
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Tidskriftsartikel (refereegranskat)abstract
- Plasma endothelin-1, the nitric oxide (NO) mediator intraplatelet cyclic guanosine monophosphate (cGMP), the prostacyclin mediator cyclic adenosine monophosphate (cAMP) and the macrophage derived inflammatory mediator plasma neopterin were measured in men with Type 2 diabetes mellitus (n = 91), impaired glucose tolerance (IGT; n = 51), previously abnormal glucose tolerance (PAGT; n = 20), and 34 healthy control men. Plasma endothelin-1 was higher in men with Type 2 diabetes mellitus than in controls [4.1 (1.0-14.3) vs. 2.1 (0.2-8.7) ng/l; P < 0.001). Intraplatelet cGMP was higher in men with PAGT [0.84 (0.57-2.76) pmol/109 platelets; P < 0.05], IGT [0.85 (0.48-3.53); P < 0.001] and Type 2 diabetes mellitus [0.90 (0.47-3.86); P < 0.001] than in controls [0.70 (0.42-1.70]. No differences existed between groups concerning intraplatelet cAMP or plasma neopterin. Plasma endothelin-1 correlated with fasting plasma glucose (r = 0.33; P < 0.001) and HbA1(c) (r = 0.29; P < 0.001). In conclusion, elevated plasma endothelin-1 in Type 2 diabetes mellitus and its relationship to glucose and HbA1(c) suggest a putative role for endothelin-1 in diabetic endothelial cell damage. Increased cGMP indicating enhanced production/activity of NO suggests that factors other than reduced NO activity contribute to enhanced platelet aggregation in diabetes. (C) 2000 Elsevier Science Ireland Ltd.
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| 7. |
- Anwaar, I., et al.
(författare)
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Increasing levels of leukocyte-derived inflammatory mediators in plasma and cAMP in platelets during follow-up after acute cerebral ischemia
- 1998
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Ingår i: Cerebrovascular Diseases. - : S. Karger AG. - 1015-9770 .- 1421-9786. ; 8:6, s. 310-317
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Tidskriftsartikel (refereegranskat)abstract
- Inflammatory mediators secreted by activated leukocytes play a role in the pathogenesis of atherosclerosis. They may also affect the production of vasodilatory and platelet antiaggregatory factors such as nitric oxide (NO) and prostacyclin (PGI2) from the vascular endothelium. Production of NO and PGI2, the effecs of which are mediated by cyclic 3',5'-guanosine monophosphate (cGMP) and cyclic 3',5'-adenosine monophosphate (cAMP), respectively, is disturbed in atherosclerosis, whereas increased NO levels have been found in acute cerebral ischemia. To investigate leukocyte activation and its possible influence upon endothelial function in cerebral ischemia we measured plasma neutrophil gelatinase-associated lipocalin (NGAL) and soluble tumor necrosis factor receptor protein-1 (sTNFR-1) by ELISA, and intraplatelet cAMP and cGMP by radioimmunoassay in 59 patients with acute ischemic stroke or transient ischemic attack (mean age 71 years, 27 males) and after a 1-year follow-up in 57/59 (97%) patients. NGAL (152 ± 58 vs. 126 ± 48 μg/l), sTNFR-1 (3.50 ± 2.2 vs. 2.59 ± 1.31 μg/l), and cAMP(5.12 ± 1.71 vs. 4.06 ± 0.92 pmol/109 platelets) were higher (p < 0.001) after follow-up than in acute cerebral ischemia. At follow-up sTNFR-1 and cGMP partially correlated (r = 0.31; p < 0.05), controlling for age and platelet count. In conclusion, plasma NGAL and sTNFR-1 and intraplatelet AMP increase after acute cerebral ischemia, indicating chronic inflammatory activity and endothelial activation. Plasma sTNFR-1 levels are related to intraplatelet cGMP levels.
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| 8. |
- Bansal, Vibha, et al.
(författare)
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Recovery of urokinase from integrated mammalian cell culture cryogel bioreactor and purification of the enzyme using p-aminobenzamidine affinity chromatography
- 2006
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Ingår i: Journal of Molecular Recognition. - : Wiley. - 1099-1352 .- 0952-3499. ; 19:4, s. 332-339
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Tidskriftsartikel (refereegranskat)abstract
- An integrated product recovery system was developed to separate urokinase from the cell culture broth of human kidney cells HT1080. Supermacroporous monolithic cryogels provided ideal matrices with respect to surface and flow properties for use as cell culture scaffold as well as for affinity chromatographic capture step of the enzyme in the integrated system. The urokinase was produced continuously in the reactor running for 4 weeks with continuous circulation of 500 ml of culture medium. The enzyme activity in the culture medium reached to 280 Plough units (PU)/mg protein. Cu(II)-iminodiacetic acid (IDA)-polyacrylamide (pAAm) cryogel column was used to capture urokinase by integrating with the gelatin-coupled pAAm-cryogel bioreactor for HT1080 cell culture. After removing the urokinase capture column from the integrated system the bound protein was eluted. The metal affinity capture step gave 4.5-fold purification of the enzyme thus achieving a specific activity of 1300 PU/mg protein. The enzyme eluate from Cu(11)-IDA-pAAm cryogel capture column was further purified on benzamidine-Sepharose affinity column. This step finally led to a homogeneous preparation of different forms of urokinase in two different ellution peaks with a best urokinase activity of 13 550 PU/mg of protein. As compared to initial activity in the cell culture broth, about 26.2- and 48.4-fold increase in specific activity was achieved with enzyme yields corresponding to 32% and 35% in two different peak fractions, respectively. Native electrophoresis and SDS-PAGE showed multiple protein bands corresponding to different forms of the urokinase, which were confirmed by Western blotting and zymography. Copyright (c) 2006 John Wiley & Sons, Ltd.
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| 9. |
- Bentzer, Peter, et al.
(författare)
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Infusion of prostacyclin following experimental brain injury in the rat reduces cortical lesion volume
- 2001
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 18:3, s. 275-285
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial-derived prostacyclin is an important regulator of microvascular function, and its main actions are inhibition of platelet/leukocyte aggregation and adhesion, and vasodilation. Disturbances in endothelial integrity following traumatic brain injury (TBI) may result in insufficient prostacyclin production and participate in the pathophysiological sequelae of brain injury. The objective of this study was to evaluate the potential therapeutic effects of a low-dose prostacyclin infusion on cortical lesion volume, CA3 neuron survival and functional outcome following TBI in the rat. Anesthetized animals (sodium pentobarbital, 60 mg/kg, i.p.) were subjected to a lateral fluid percussion brain injury (2.5 atm) or sham injury. Following TBI, animals were randomized to receive a constant infusion of either prostacyclin (1 ng/kg x min(-1) i.v.) or vehicle over 48 h. All sham animals received vehicle (n = 6). Evaluation of neuromotor function, lesion volume, and CA3 neuronal loss was performed blindly. By 7 days postinjury, cortical lesion volume was significantly reduced by 43% in the prostacyclin-treated group as compared to the vehicle treated group (p < 0.01; n = 12 prostacyclin, n = 12 vehicle). No differences were observed in neuromotor function (48 h and 7 days following TBI), or in hippocampal cell loss (7 days following TBI) between the prostacyclin- and vehicle-treated groups. We conclude that prostacyclin in a low dose reduces loss of neocortical neurons following TBI and may be a potential clinical therapeutic agent to reduce neuronal cell death associated with brain trauma.
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| 10. |
- Bernspång, Lars, et al.
(författare)
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Verification of an explicit finite-element code for the simulation of the press forming of rectangular boxes of coated sheet steels
- 1993
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Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136 .- 1873-4774. ; 39:3-4, s. 431-453
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Tidskriftsartikel (refereegranskat)abstract
- The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured. The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
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