| 1. |
- Badawy, Mona, et al.
(författare)
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Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases
- 2017
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Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu? nicompartmental knee arthroplasty in the Nordic countries. Methods: 14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI). Results: The implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups. Conclusion: Low volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.
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| 2. |
- Bengtsson, Magnus W., et al.
(författare)
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Food-induced expression of orexin receptors in rat duodenal mucosa regulates the bicarbonate secretory response to orexin-A
- 2007
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Ingår i: American Journal of Physiology - Gastrointestinal and Liver Physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 293:2, s. G501-G509
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Tidskriftsartikel (refereegranskat)abstract
- Presence of appetite-regulating peptides orexin-A and orexin-B in mucosal endocrine cells suggests a role in physiological control of the intestine. Our aim was to characterize orexin-induced stimulation of duodenal bicarbonate secretion and modulation of secretory responses and mucosal orexin receptors by overnight food deprivation. Lewis x Dark Agouti rats were anesthetized and proximal duodenum cannulated in situ. Mucosal bicarbonate secretion (pH stat) and mean arterial blood pressure were continuously recorded. Orexin-A was administered intra-arterially close to the duodenum, intraluminally, or into the brain ventricles. Total RNA was extracted from mucosal specimens, reverse transcribed to cDNA and expression of orexin receptors 1 and 2 (OX1 and OX2) measured by quantitative real-time PCR. OX1 protein was measured by Western blot. Intra-arterial orexin-A (60–600 nmol·h–1·kg–1) increased (P < 0.01) the duodenal secretion in fed but not in fasted animals. The OX1 receptor antagonist SB-334867, which was also found to have a partial agonist action, abolished the orexin-induced secretory response but did not affect secretion induced by the muscarinic agonist bethanechol. Atropine, in contrast, inhibited bethanechol but not orexin-induced secretion. Orexin-A infused into the brain ventricles (2–20 nmol·kg–1·h–1) or added to luminal perfusate (1.0–100 nM) did not affect secretion, indicating that orexin-A acts peripherally and at basolateral receptors. Overnight fasting decreased mucosal OX1 and OX2 mRNA expression (P < 0.01) as well as OX1 protein expression (P < 0.05). We conclude that stimulation of secretion by orexin-A may involve both receptor types and is independent of cholinergic pathways. Intestinal OX receptors and secretory responses are markedly related to food intake.
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| 3. |
- Bengtsson, Magnus W., et al.
(författare)
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Short food deprivation inhibits orexin receptor 1 expression and orexin-A induced intracellular calcium signaling in acutely isolated duodenal enterocytes
- 2009
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Ingår i: American Journal of Physiology - Gastrointestinal and Liver Physiology. - : American Physiological Society. - 0193-1857 .- 1522-1547. ; 296:3, s. G651-G658
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Tidskriftsartikel (refereegranskat)abstract
- Bengtsson MW, Makela K, Herzig KH, Flemstrom G. Short food deprivation inhibits orexin receptor 1 expression and orexin-A induced intracellular calcium signaling in acutely isolated duodenal enterocytes. Am J Physiol Gastrointest Liver Physiol 296: G651-G658, 2009. First published December 31, 2008; doi:10.1152/ajpgi.90387.2008.-Close intra-arterial infusion of the appetite regulating peptide orexin-A stimulates bicarbonate secretion from the duodenal mucosa. The aim of the present study was to elucidate the ability of orexin-A to induce intracellular calcium signaling in acutely isolated duodenal enterocytes. Freshly isolated clusters of enterocytes, obtained from rat duodenal mucosa or human duodenal biopsies, were loaded with fura 2-AM and mounted in a perfusion chamber. Cryptlike enterocytes were selected (caged), and changes in intracellular calcium concentration ([Ca2+](i)) were evaluated by fluorescence imaging. Total RNA was extracted from pellets of enterocytes and reverse transcribed to cDNA, and expression of orexin receptors 1 and 2 (OX1R and OX2R) was measured by quantitative real-time PCR. Orexin-A at all concentrations tested (1-100 nM) increased [Ca2+](i) in enterocytes isolated from continuously fed rats, and the OX1R-antagonist SB-334867 (10 nM) attenuated the response. The primary [Ca2+](i) response was a slow increase to a sustained plateau persisting after orexin-A removal, and a similar response was observed in enterocytes from human biopsies. In contrast to orexin-A, the OX2R agonist (Ala(11), D-Leu(15))orexin-B (1-10 nM) did not induce calcium signaling. There were no significant [Ca2+](i) responses in enterocytes from animals food deprived overnight, and overnight fasting decreased (P < 0.01) enterocyte OX1R as well as OX2R mRNA. Induction of intracellular calcium signaling in isolated duodenal enterocytes is thus mediated primarily by OX1R receptors. Short (overnight) food deprivation markedly depresses receptor expression and inhibits orexin-A induced increases in [Ca2+](i). Studies of enterocyte signaling and intestinal secretion requires particular evaluation regarding feeding status.
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| 4. |
- Bomström, Henri, et al.
(författare)
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Digital Twins About Humans—Design Objectives From Three Projects
- 2022
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Ingår i: Journal of Computing and Information Science in Engineering. - : The American Society of Mechanical Engineers. - 1530-9827 .- 1944-7078. ; 22:5
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Tidskriftsartikel (refereegranskat)abstract
- Digital twin (DT) emerges as a key concept of the Industry 4.0 paradigm and beyond. However, the current literature lacks focus on humans and human activities as a part of complex system DTs. Acknowledging human aspects in DTs can enhance work performance, well-being, motivation, and personal development of professionals. This study examines emerging requirements for human digital twins (HDTs) in three use cases of industry–academia collaboration on complex systems. The results draw together the overall design problem and four design objectives for HDTs. We propose to combine the machine and human-related aspects of DTs and highlight the need for virtual-to-virtual interoperability between HDTs and machines alike. Furthermore, we outline differences between humans and machines regarding digital twinning by addressing human activities and knowledge-based behavior on systems. Design of HDTs requires understanding of individual professional characteristics, such as skills and information preferences, together with twinning between the physical and digital machine entities and interactions between the human and machine DTs. As the field moves toward including humans as a part of the DT concept, incorporating HDTs in complex systems emerges as an increasingly significant issue.
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| 5. |
- Broström, Markus, et al.
(författare)
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Condensation in the KCl–NaCl system
- 2013
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Ingår i: Fuel processing technology. - Amsterdam : Elsevier. - 0378-3820 .- 1873-7188. ; 105, s. 142-148
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Tidskriftsartikel (refereegranskat)abstract
- Condensation of gaseous KCl and NaCl is known to participate in deposit formation and high temperature corrosion processes in heat and power plants. Little is known about interaction between the two salts, which is of interest for the overall understanding of deposit and corrosion problems. Within this study, condensation at different material surface temperatures and salt mixtures was investigated.Salt vapors were prepared by temperature controlled evaporation. A cooled condensation probe with a temperature gradient was inserted in the hot gas. After exposure, the probe surface was visually inspected and analyzed with SEM/EDS and XRD for elemental and phase composition. TGA/DTA was used to provide complementary information on vaporization and sintering.The results indicated that a mixture of KCl and NaCl probably condenses as separate phases at concentrations and temperatures below the melting points of the salts. Condensation was possibly followed by a secondary sintering process. It was verified by TGA/DTA that a mixture of solid KCl and NaCl particles sinters and melts rapidly at temperatures above the melting temperature of a corresponding solution. It was also seen that sintering took place at lower temperatures with slow solid-gas interactions, possibly with the formation of solid solutions.
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| 6. |
- Enestam, Sonja, et al.
(författare)
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Occurrence of Zinc and Lead in Aerosols and Deposits in the Fluidized-Bed Combustion of Recovered Waste Wood. Part 2: Thermodynamic Considerations
- 2011
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Ingår i: Energy & Fuels. - : ACS publications. - 0887-0624 .- 1520-5029. ; 25:4, s. 1970-1977
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, which is the second part in a series of two, multi-phase, multi-component equilibrium calculations were used to study the chemistry and deposition behavior of lead and zinc in the combustion of recovered waste wood (RWW). Particular attention was paid to the deposition behavior in different parts of the boiler under varying flue gas and material temperature conditions. In addition, the influence of fuel composition was considered by studying three different fuel compositions. The results from the calculations were compared to experimental results from two measurement campaigns, whose goal was to experimentally determine the distribution and speciation of zinc and lead compounds in aerosol particles and deposits in the fluidized-bed combustion of RWW. The results from the experimental work are presented in part 1 (10.1021/ef101478n) of this work.
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| 7. |
- Flemström, Gunnar, 1941-, et al.
(författare)
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Apelin stimulation of duodenal bicarbonate secretion : feeding-dependent and mediated via apelin-induced release of enteric cholecystokinin
- 2011
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Ingår i: Acta Physiologica. - Oxford : Wiley-Blackwell. - 1748-1708 .- 1748-1716. ; 201:1, s. 141-150
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Apelin peptides is the endogenous ligand of the G protein-coupled receptor APJ. Proposed actions include involvement in control of cardiovascular functions, appetite and body metabolism. We have investigated effects of apelin peptides on duodenal bicarbonate secretion in vivo and the release of cholecystokinin (CCK) from acutely isolated mucosal cells and the neuroendocrine cell line STC-1. Methods: Lewis x Dark Agouti rats had free access to water and, unless fasted overnight, free access to food. A segment of proximal duodenum was cannulated in situ in anesthetized animals. Mucosal bicarbonate secretion was titrated (pH stat) and apelin was administered to the duodenum by close intra-arterial infusion. Total RNA was extracted from mucosal specimens, reverse transcripted to cDNA and expression of the APJ receptor measured by quantitative real-time PCR. Apelin-induced release of CCK was measured using (i) cells prepared from proximal small intestine, and (ii) STC-1 cells. Results: Even the lowest dose of apelin-13 (6 pmol kg-1 h-1) caused a significant rise in bicarbonate secretion. Stimulation occurred only in continuously fed animals and even a 100-fold greater dose (600 pmol kg-1 h-1) of apelin was without effect in overnight food deprived animals. Fasting also induced a 8-fold decrease in the expression of APJ receptor mRNA. Apelin induced significant release of CCK from both mucosal and STC-1 cells, and the CCKA receptor antagonist devazepide abolished bicarbonate secretory responses to apelin. Conclusions: Apelin-induced stimulation of duodenal electrolyte secretion is feeding dependent and mediated by local mucosal release of CCK
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| 8. |
- Flemström, Gunnar, 1941-, et al.
(författare)
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Effects of short-term food deprivation on orexin-A-induced intestinal bicarbonate secretion in comparison with related secretagogues
- 2010
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Ingår i: Acta Physiologica. - Oxford : Wiley-Blackwell. - 1748-1708 .- 1748-1716. ; 198:3, s. 373-380
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Forskningsöversikt (refereegranskat)abstract
- Studies of gastrointestinal physiology in humans and intact animals are usually conducted after overnight fast. We have compared effects of orexin-A, vasoactive intestinal polypeptide (VIP), melatonin, serotonin, uroguanylin, ghrelin and prostaglandin E2 (PGE2) on duodenal bicarbonate secretion in fed and overnight fasted animals. This review is a summary of our findings. Secretagogues were administered by intra-arterial infusion or luminally (PGE2) Enterocyte intracellular calcium ([Ca2+]i) signaling was studied by fluorescence imaging. Total RNA was extracted, reverse transcripted to cDNA and expression of orexin receptors measured by quantitative real-time PCR. Orexin-A stimulates the duodenal secretion in continuously fed animals but not in food deprived animals. Similarly, short fasting causes a 100-fold decrease of the amount of the muscarinic agonist bethanechol required for stimulation of secretion. In contrast, fasting does not affect secretory responses to intra-arterial VIP, melatonin, serotonin, uroguanylin and ghrelin, or that to luminal PGE2. Orexin-A induces [Ca2+]i signaling in enterocytes from fed rats but no significant [Ca2+]i responses occurs in enterocytes from fasted animals. In addition, overnight fasting decreases the expression of mucosal and enterocyte orexin receptors. Short food deprivation thus decreases duodenal expression of orexin receptors and abolishes the secretory response to orexin-A as well as orexin-A induced [Ca2+]i signaling. Fasting, furthermore, decreases mucosal sensitivity to bethanechol. The absence of declines in secretory responses to other secretagogues tested is strong evidence that short fasting does affect not the secretory capacity of the duodenal mucosa in general. Studies of intestinal secretion require particular evaluation with respect to feeding status.
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| 9. |
- Laine, Saara, et al.
(författare)
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Effects of Different Exercise Training Protocols on Gene Expression of Rac1 and PAK1 in Healthy Rat Fast- and Slow-Type Muscles.
- 2020
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Rac1 and its downstream target PAK1 are novel regulators of insulin and exercise-induced glucose uptake in skeletal muscle. However, it is not yet understood how different training intensities affect the expression of these proteins. Therefore, we studied the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on Rac1 and PAK1 expression in fast-type (gastrocnemius, GC) and slow-type (soleus, SOL) muscles in rats after HIIT and MICT swimming exercises.Methods: The mRNA expression was determined using qPCR and protein expression levels with reverse-phase protein microarray (RPPA).Results: HIIT significantly decreased Rac1 mRNA expression in GC compared to MICT (p = 0.003) and to the control group (CON) (p = 0.001). At the protein level Rac1 was increased in GC in both training groups, but only the difference between HIIT and CON was significant (p = 0.02). HIIT caused significant decrease of PAK1 mRNA expression in GC compared to MICT (p = 0.007) and to CON (p = 0.001). At the protein level, HIIT increased PAK1 expression in GC compared to MICT and CON (by ∼17%), but the difference was not statistically significant (p = 0.3, p = 0.2, respectively). There were no significant differences in the Rac1 or PAK1 expression in SOL between the groups.Conclusion: Our results indicate that HIIT, but not MICT, decreases Rac1 and PAK1 mRNA expression and increases the protein expression of especially Rac1 but only in fast-type muscle. These exercise training findings may reveal new therapeutic targets to treat patients with metabolic diseases.
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| 10. |
- Mäkelä, Kari
(författare)
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Effekter av kallstarter och kallkörning
- 1995
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Ingår i: VTI:s och KFB:s forskardagar. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 41-48
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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