| 1. |
- Berntson, Björn K., et al.
(author)
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Elliptic soliton solutions of the spin non-chiral intermediate long-wave equation
- 2023
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In: Letters in Mathematical Physics. - : Springer Nature. - 0377-9017 .- 1573-0530. ; 113:3
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Journal article (peer-reviewed)abstract
- We construct elliptic multi-soliton solutions of the spin non-chiral intermediate long-wave (sncILW) equation with periodic boundary conditions. These solutions are obtained by a spin-pole ansatz including a dynamical background term; we show that this ansatz solves the periodic sncILW equation provided the spins and poles satisfy the elliptic A-type spin Calogero-Moser (sCM) system with certain constraints on the initial conditions. The key to this result is a Backlund transformation for the elliptic sCM system which includes a non-trivial dynamical background term. We also present solutions of the sncILW equation on the real line and of the spin Benjamin-Ono equation which generalize previously obtained solutions by allowing for a non-trivial background term.
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| 2. |
- Berntson, Björn K., et al.
(author)
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Spin generalizations of the Benjamin-Ono equation
- 2022
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In: Letters in Mathematical Physics. - : Springer Nature. - 0377-9017 .- 1573-0530. ; 112:3
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Journal article (peer-reviewed)abstract
- We present new soliton equations related to the A-type spin Calogero-Moser (CM) systems introduced by Gibbons and Hermsen. These equations are spin generalizations of the Benjamin-Ono (BO) equation and the recently introduced non-chiral intermediate long-wave (ncILW) equation. We obtain multi-soliton solutions of these spin generalizations of the BO equation and the ncILW equation via a spin-pole ansatz where the spin-pole dynamics is governed by the spin CM system in the rational and hyperbolic cases, respectively. We also propose physics applications of the new equations, and we introduce a spin generalization of the standard intermediate long-wave equation which interpolates between the matrix Korteweg-de Vries equation, the Heisenberg ferromagnet equation, and the spin BO equation.
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| 3. |
- Di Fabio, Francesco, et al.
(author)
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The impact of laparoscopic versus open colorectal cancer surgery on subsequent laparoscopic resection of liver metastases : A multicenter study.
- 2015
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In: Surgery. - : Elsevier BV. - 0039-6060 .- 1532-7361. ; 157:6, s. 1046-54
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Journal article (peer-reviewed)abstract
- BACKGROUND: Laparoscopic liver surgery is expanding. Most laparoscopic liver resections for colorectal carcinoma metastases are performed subsequent to the resection of the colorectal primary, raising concerns about the feasibility and safety of advanced laparoscopic liver surgery in the context of an abdomen with possible postoperative adhesions. The aim was to compare the outcome of laparoscopic hepatectomy for colorectal metastases after open versus laparoscopic colorectal surgery.METHODS: This observational, multicenter study reviewed 394 patients undergoing laparoscopic minor and major liver resection for colorectal carcinoma metastases. Main outcome measures were intraoperative unfavorable incidents and short-term results in patients who had previous open versus laparoscopic colorectal cancer surgery.RESULTS: Three hundred six patients (78%) had prior open and 88 (22%) had prior laparoscopic colorectal resection. Laparoscopic major hepatectomies were undertaken in 63 (16%). Intraoperative unfavorable incidents during laparoscopic liver surgery were significantly higher among patients who had prior open colorectal surgery (26%) compared with the laparoscopic group (14%; P = .017). Positive resection margins and postoperative complications were not associated with the approach adopted for the resection of the primary cancer. On multivariate logistic regression analysis, intraoperative unfavorable incidents were associated significantly only with prior open colorectal surgery (odds ratio, 2.8; P = .006) and laparoscopic major hepatectomy (odds ratio, 2.4; P = .009).CONCLUSION: Laparoscopic minor hepatectomy can be performed safely in patients who have undergone previous open colorectal surgery. Laparoscopic major hepatectomy after open colorectal surgery may be challenging. Careful risk assessment in the decision-making process is required not to compromise patient safety and to guarantee the expected benefits from the minimally invasive approach.
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| 4. |
- Edwin, Aaron, 1983-, et al.
(author)
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Calcium binding by the PKD1 domain regulates interdomain flexibility in Vibrio cholerae metalloprotease PrtV
- 2013
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In: FEBS Open Bio. - : Elsevier. - 2211-5463. ; 3, s. 263-270
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Journal article (peer-reviewed)abstract
- Vibrio cholerae, the causative agent of cholera, releases several virulence factors including secreted proteases when it infects its host. These factors attack host cell proteins and break down tissue barriers and cellular matrix components such as collagen, laminin, fibronectin, keratin, elastin, and they induce necrotic tissue damage. The secreted protease PrtV constitutes one virulence factors of V. cholerae. It is a metalloprotease belonging to the M6 peptidase family. The protein is expressed as an inactive, multidomain, 102 kDa pre-pro-protein that undergoes several N- and C-terminal modifications after which it is secreted as an intermediate variant of 81 kDa. After secretion from the bacteria, additional proteolytic steps occur to produce the 55 kDa active M6 metalloprotease. The domain arrangement of PrtV is likely to play an important role in these maturation steps, which are known to be regulated by calcium. However, the molecular mechanism by which calcium controls proteolysis is unknown. In this study, we report the atomic resolution crystal structure of the PKD1 domain from V. cholera PrtV (residues 755–838) determined at 1.1 Å. The structure reveals a previously uncharacterized Ca2+-binding site located near linker regions between domains. Conformational changes in the Ca2+-free and Ca2+-bound forms suggest that Ca2+-binding at the PKD1 domain controls domain linker flexibility, and plays an important structural role, providing stability to the PrtV protein.
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| 5. |
- Eiriksson, Kristinn, 1967-
(author)
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Technical Aspects of Laparoscopic Liver Resection. An Experimental Study
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Various techniques are used to transect the liver. With increase in laparoscopic liver resections (LLR), it is of even more interest to develop surgical techniques to minimize bleeding and the risk for gas embolism during transection. Instrument like argon enhanced coagulator provides good hemostasis but increases the danger of gas embolism. The CO2 pneumoperitoneum that is routinely used in most types of laparoscopic surgery can be modified by the use of different gas pressure. It can be assumed that different pressure influences bleeding but also the risk for gas embolism.In presented porcine studies, three instrumental combinations have been studied. In study I sixteen piglets were randomized to LLR with either the cavitron ultrasonic aspirator (CUSA™) in combination with vessels sealing system (Ligasure™) or with CUSA™ and ultrascision scissors (Autosonix™), with the endpoints of intra-operative bleeding and gas embolism. In study IV sixteen piglets were randomized to LLR either with staple device (Endo-GIA™) or the Ligasure™ - CUSA™ combination with same primary endpoints and additionally secondary endpoints of effect on gas-exchange, systemic- and pulmonary hemodynamic.Focusing on intra-abdominal pressure (IAP) in study II, sixteen piglets were randomized to LLR with an IAP of either 8 or 16 mmHg. Primary endpoints were bleeding and gas embolism and secondary endpoints, effect on gas-exchange, systemic- and pulmonary hemodynamic.In study III effect of argon gas was tested during LLR. Sixteen piglets were randomized to either argon pneumoperitoneum or CO2 pneumoperitoneum. Primary endpoints were effect on gas-exchange, systemic- and pulmonary hemodynamic.In presented studies, we tested efficacy and safety of different techniques for LLR. CUSA™ can be used in combination with either Ligasure™ or Autosonix™. However, Ligasure™ reduces the amount of bleeding. The recent introduction of staplers seems promising with a further reduction in bleeding, gas embolism, and operating time. The IAP influences both the amount of bleeding as well as gas embolism. It seems reasonable to use a higher IAP to decrease bleeding with caution and with close monitoring for gas embolism. Argon gas embolism gives more extensive effect on gas-exchange and hemodynamic and should probably be avoided in this type of surgery.
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| 6. |
- Høye, Eirik, et al.
(author)
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A comprehensive framework for analysis of microRNA sequencing data in metastatic colorectal cancer
- 2022
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In: NAR Cancer. - : Oxford University Press (OUP). - 2632-8674. ; 4:1
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Journal article (peer-reviewed)abstract
- Although microRNAs (miRNAs) contribute to all hallmarks of cancer, miRNA dysregulation in metastasis remains poorly understood. The aim of this work was to reliably identify miRNAs associated with metastatic progression of colorectal cancer (CRC) using novel and previously published next-generation sequencing (NGS) datasets generated from 268 samples of primary (pCRC) and metastatic CRC (mCRC; liver, lung and peritoneal metastases) and tumor adjacent tissues. Differential expression analysis was performed using a meticulous bioinformatics pipeline, including only bona fide miRNAs, and utilizing miRNA-tailored quality control and processing. Five miRNAs were identified as up-regulated at multiple metastatic sites Mir-210_3p, Mir-191_5p, Mir-8-P1b_3p [mir-141–3p], Mir-1307_5p and Mir-155_5p. Several have previously been implicated in metastasis through involvement in epithelial-to-mesenchymal transition and hypoxia, while other identified miRNAs represent novel findings. The use of a publicly available pipeline facilitates reproducibility and allows new datasets to be added as they become available. The set of miRNAs identified here provides a reliable starting-point for further research into the role of miRNAs in metastatic progression.
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| 7. |
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| 8. |
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| 9. |
- Johansson, Martin L, et al.
(author)
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Achieving stomal continence with an ileal pouch and a percutaneous implant.
- 2022
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In: Journal of materials science. Materials in medicine. - : Springer Science and Business Media LLC. - 1573-4838 .- 0957-4530. ; 33:1
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Journal article (peer-reviewed)abstract
- In this study, a soft-tissue-anchored, percutaneous port used as a mechanical continence-preserving valve in reservoir ileo- and urostomies was functionally and morphologically evaluated in eight dogs. During follow-up, the skin failed to attach to the implant, but the intestine inside the stoma port appeared to be attached to the mesh. After reaching adequate reservoir volume, the urostomies were rendered continent by attaching a lid to the implant. The experiments were ended at different time intervals due to implant-related adverse events. In only one case did the histological evaluation reveal integration at both the implant-intestine and implant-skin interfaces, with a low degree of inflammation and the absence of bacterial colonisation. In the remaining cases, integration was not obtained and instead mucosal downgrowth and biofilm formation were observed. The skin-implant junction was characterised by the absence of direct contact between the epidermis and the implant. Varying degrees of epidermal downgrowth, granulation tissue formation, inflammatory cell infiltration and bacterial growth and biofilm formation were prominent findings. In contrast, the subcutaneously located anchor part of the titanium port was well integrated and encapsulated by fibrous tissue. These results demonstrate the opportunity to achieve integration between a soft-tissue-anchored titanium port, skin and intestine. However, predictable long-term function could not be achieved in these animal models due to implant- and non-implant-related adverse events. Unless barriers at both the implant-skin and implant-intestine junctions are created, epidermal and mucosal downward migration and biofilm formation will jeopardise implant performance.
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| 10. |
- Johansson, Martin L, et al.
(author)
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Integration between a percutaneous implant and the porcine small bowel.
- 2011
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In: Journal of biomedical materials research. Part B, Applied biomaterials. - : Wiley. - 1552-4981 .- 1552-4973. ; 98:1, s. 101-9
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Journal article (peer-reviewed)abstract
- Inflammatory bowel diseases, cancer or trauma may require removal of all or part of the intestines, leaving the patient with a need to wear external stoma appliances for collection of bowel contents. By connecting the small bowel to a percutaneous port, equipped with a sealing lid, a fully continent and leak proof stoma can be created without a need for permanently wearing stoma appliance. The prerequisites for a connection between a permanent, transabdominal implant and a visceral organ are largely unexplored. Stoma ports made of titanium were implanted in the abdominal wall of domestic pigs and a branch of distal ileum was inserted through the ports. After being followed for 1-3 weeks, the ports were removed and subjected to histological evaluation to study the influence of their shape, structure, and position on the tissue response. Particular focus was attended to the attachment of the ileal serosal surface to the implants inner structure consisting of a titanium mesh. Macroscopic examination revealed fistulas and formation of abscesses in 4 of 11 the retrieved implants. Histological examination revealed regenerated and well-vascularized collagenous tissue around the mesh structure inside the implant. The integration was complete or partial for 10 of 11 ports. Despite various degrees of inflammation and tissue ingrowth, it was demonstrated for the first time that the serosal surface of ileum was firmly attached to the internal structure of the implant. These experiments provide a basis for optimization of the implant and surgical procedure before long-term functional animal experiments.
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