| 71. |
- Klintman, Daniel, et al.
(författare)
-
Leukocyte recruitment in hepatic injury: selectin-mediated leukocyte rolling is a prerequisite for CD18-dependent firm adhesion.
- 2002
-
Ingår i: Journal of Hepatology. - 0168-8278. ; 36:1, s. 53-59
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: This study was designed to examine the role of selectins and CD18 in leukocyte recruitment in hepatic injury induced by tumor necrosis factor-alpha (TNF-alpha) and galactosamine (Gal) in vivo.Methods: Intravital fluorescence microscopy of the hepatic microcirculation was used to quantify leukocyte-endothelium interactions provoked by 24 h of systemic TNF-alpha/Gal challenge in rats. Hepatic injury was evaluated with liver enzymes.Results: When administered after 24 h of TNF-alpha/Gal challenge, fucoidan, a selectin-function inhibitor, reduced leukocyte rolling by 69%, whereas firm adhesion was unaltered. In contrast, passive immunization against CD18 decreased leukocyte adhesion by 60%, whereas rolling remained unchanged. Notably, when administered prior to TNF-alpha/Gal, fucoidan attenuated both leukocyte rolling and adhesion, by 57 and 69%, respectively. Pretreatment with an anti-CD18 antibody decreased TNF-alpha/Gal-induced rolling and firm adhesion by 25 and 90%, respectively. Moreover, pretreatment with fucoidan and the anti-CD18 antibody both protected against TNF-alpha/Gal-induced increases in liver enzymes. For example, the pretreatments reduced alanine aminotransferase by 59 and 87%, respectively.Conclusions: Our data suggest that TNF-alpha/Gal-induced leukocyte rolling is selectin-mediated and a precondition for CD18-dependent firm adhesion in hepatic venules. Thus, reducing leukocyte recruitment by inhibition of selectins or CD18 may be useful to control TNF-alpha-induced liver injury.
|
|
| 72. |
|
|
| 73. |
- Klintman, Daniel, et al.
(författare)
-
Protective effect of Linomide on TNF-alpha-induced hepatic injury.
- 2002
-
Ingår i: Journal of Hepatology. - 0168-8278. ; 36:2, s. 226-232
-
Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Linomide is an immunomodulator that ameliorates several autoimmune and inflammatory diseases. We assessed the effect of Linomide on microvascular perfusion failure, leukocyte recruitment and hepatocellular injury induced by tumor necrosis factor alpha (TNF-alpha) and D-Galactosamine (Gal).Methods: After 3 days of Linomide pretreatment (1, 10 and 100mg/kg/day), rats were challenged with TNF-alpha/Gal for 24h. Microvascular perfusion, leukocyte--endothelium interactions in hepatic postsinusoidal venules and leukocyte sequestration in sinusoids were evaluated using intravital microscopy. Liver enzymes were measured spectrophotometrically.Results: Challenge with TNF-alpha/Gal significantly reduced sinusoidal perfusion, and increased leukocyte rolling, adhesion and liver enzymes. Interestingly, pretreatment with Linomide (10 and 100mg/kg/day) significantly reduced TNF-alpha/Gal-induced leukocyte rolling by 65 and 63%, and leukocyte adhesion by 87 and 84%, respectively. Moreover, Linomide (10 and 100mg/kg/day) decreased sinusoidal sequestration of leukocytes by 71 and 51%, and markedly improved sinusoidal perfusion. Moreover, Linomide reduced aspartate aminotransferase by 87--97%, and alanine aminotransferase by 79--96%. However, Linomide had no protective effect when administered concomitantly with TNF-alpha/Gal.Conclusions: These data demonstrate a dose-dependent inhibitory effect of Linomide on perfusion failure, leukocyte recruitment and hepatocellular injury provoked by TNF-alpha. Indeed, these findings suggest that Linomide may be an effective substance for protection of the liver in sepsis.
|
|
| 74. |
|
|
| 75. |
- Koulaouzidis, Anastasios, et al.
(författare)
-
Association Between Fecal Calprotectin Levels and Small-bowel Inflammation Score in Capsule Endoscopy : A Multicenter Retrospective Study
- 2016
-
Ingår i: Digestive Diseases and Sciences. - : Springer Science and Business Media LLC. - 1573-2568 .- 0163-2116. ; 61:7, s. 2033-2040
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Accurate inflammation reporting in capsule endoscopy (CE) is important for diagnosis and monitoring of treatment of inflammatory bowel disease (IBD). Fecal calprotectin (FC) is a highly specific biomarker of gut inflammation. Lewis score (LS) was developed to standardize quantification of inflammation in small-bowel (SB) CE images.GOALS: Multicenter retrospective study aiming to investigate correlation between LS and FC in a large group of patients undergoing CE for suspected or known small-bowel IBD, and to develop a model for prediction of CE results (LS) based on FC levels.STUDY: Five academic centers and a district general hospital offering CE in UK, Finland, Sweden, Canada, and Israel. In total, 333 patients were recruited. They had small-bowel CE and FC done within 3 months.RESULTS: Overall, correlation between FC and LS was weak (r s: 0.232, P < 0.001). When two clinically significant FC thresholds (100 and 250 μg/g) were examined, the r s between FC and LS was 0.247 (weak) and 0.337 (moderate), respectively (P = 0.307). For clinically significant (LS ≥ 135) or negative (LS < 135) for SB inflammation, ROC curves gave an optimum cutoff point of FC 76 μg/g with sensitivity 0.59 and specificity 0.41.LIMITATIONS: Retrospective design.CONCLUSIONS: LS appears to show low correlation with FC as well as other serology markers of inflammation. FC does not appear to be a reliable biomarker for significant small-bowel inflammation. Nevertheless, FC level ≥ 76 μg/g may be associated with appreciable visual inflammation on small-bowel CE in patients with negative prior diagnostic workup.
|
|
| 76. |
- Koulaouzidis, Anastasios, et al.
(författare)
-
KID Project : an internet-based digital video atlas of capsule endoscopy for research purposes
- 2017
-
Ingår i: Endoscopy International Open. - : Georg Thieme Verlag KG. - 2364-3722 .- 2196-9736. ; 5:6, s. 477-483
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Capsule endoscopy (CE) has revolutionized small-bowel (SB) investigation. Computational methods can enhance diagnostic yield (DY); however, incorporating machine learning algorithms (MLAs) into CE reading is difficult as large amounts of image annotations are required for training. Current databases lack graphic annotations of pathologies and cannot be used. A novel database, KID, aims to provide a reference for research and development of medical decision support systems (MDSS) for CE.METHODS: Open-source software was used for the KID database. Clinicians contribute anonymized, annotated CE images and videos. Graphic annotations are supported by an open-access annotation tool (Ratsnake). We detail an experiment based on the KID database, examining differences in SB lesion measurement between human readers and a MLA. The Jaccard Index (JI) was used to evaluate similarity between annotations by the MLA and human readers.RESULTS: The MLA performed best in measuring lymphangiectasias with a JI of 81 ± 6 %. The other lesion types were: angioectasias (JI 64 ± 11 %), aphthae (JI 64 ± 8 %), chylous cysts (JI 70 ± 14 %), polypoid lesions (JI 75 ± 21 %), and ulcers (JI 56 ± 9 %).CONCLUSION: MLA can perform as well as human readers in the measurement of SB angioectasias in white light (WL). Automated lesion measurement is therefore feasible. KID is currently the only open-source CE database developed specifically to aid development of MDSS. Our experiment demonstrates this potential.
|
|
| 77. |
- Koulaouzidis, Anastasios, et al.
(författare)
-
Novel experimental and software methods for image reconstruction and localization in capsule endoscopy
- 2018
-
Ingår i: Endoscopy International Open. - : Georg Thieme Verlag KG. - 2364-3722 .- 2196-9736. ; 6:2, s. 205-210
-
Tidskriftsartikel (refereegranskat)abstract
- Background and study aims : Capsule endoscopy (CE) is invaluable for minimally invasive endoscopy of the gastrointestinal tract; however, several technological limitations remain including lack of reliable lesion localization. We present an approach to 3D reconstruction and localization using visual information from 2D CE images.Patients and methods : Colored thumbtacks were secured in rows to the internal wall of a LifeLike bowel model. A PillCam SB3 was calibrated and navigated linearly through the lumen by a high-precision robotic arm. The motion estimation algorithm used data (light falling on the object, fraction of reflected light and surface geometry) from 2D CE images in the video sequence to achieve 3D reconstruction of the bowel model at various frames. The ORB-SLAM technique was used for 3D reconstruction and CE localization within the reconstructed model. This algorithm compared pairs of points between images for reconstruction and localization.Results: As the capsule moved through the model bowel 42 to 66 video frames were obtained per pass. Mean absolute error in the estimated distance travelled by the CE was 4.1 ± 3.9 cm. Our algorithm was able to reconstruct the cylindrical shape of the model bowel with details of the attached thumbtacks. ORB-SLAM successfully reconstructed the bowel wall from simultaneous frames of the CE video. The "track" in the reconstruction corresponded well with the linear forwards-backwards movement of the capsule through the model lumen.Conclusion: The reconstruction methods, detailed above, were able to achieve good quality reconstruction of the bowel model and localization of the capsule trajectory using information from the CE video and images alone.
|
|
| 78. |
- Laschke, MW, et al.
(författare)
-
New experimental approach to study host tissue response to surgical mesh materials in vivo
- 2005
-
Ingår i: Journal of Biomedical Materials Research. Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 74A:4, s. 696-704
-
Tidskriftsartikel (refereegranskat)abstract
- Implantation of surgical meshes is a common procedure to increase abdominal wall stability in hernia repair. To improve biocompatibility of the implants, sophisticated in vivo animal models are needed to study inflammation and incorporation of biomaterials. Herein, we have established a new model that allows for the quantitative analysis of host tissue response and vascular ingrowth into surgical mesh materials in vivo. Ultrapro meshes were implanted into dorsal skinfold chambers of Syrian golden hamsters. Angiogenesis, microhemodynamics, microvascular permeability, and leukocyte-endothelial cell interaction of the host tissue were analyzed in response to material implantation over a 2-week period using intravital fluorescence microscopy. Mesh implantation resulted in a short-term activation of leukocytes, reflected by leukocyte accumulation and adherence in postcapillary venules. This cellular inflammatory response was accompanied by an increase of mac-romolecular leakage, indicating loss of integrity of venular endothelial cells. Angiogenesis started at day 3 after implantation by protrusion of capillary sprouts, originating from the host microvasculature. Until day 10, these sprouts interconnected with each other to form a new microvascular network. At day 14, the inflammatory response had disappeared and the vascular ingrowth was completed. Histology confirmed the formation of granulation tissue with adequate incorporation of the mesh filaments within the host tissue. We conclude that this novel model of surgical mesh implantation is a useful experimental approach to analyze host tissue response and vascular ingrowth of newly devised materials for hernia repair.
|
|
| 79. |
- Laschke, MW, et al.
(författare)
-
Platelet-dependent accumulation of leukocytes in sinusoids mediates hepatocellular damage in bile duct ligation-induced cholestasis
- 2008
-
Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 153:1, s. 148-156
-
Tidskriftsartikel (refereegranskat)abstract
- Background:Although it is well known that extrahepatic cholestasis induces liver damage, the mechanisms are still not completely understood. The aim of the present study was to evaluate the role of platelets and P-selectin in cholestasis-induced liver injury.Experimental approach:C57BL/6 mice underwent bile duct ligation (BDL) and pretreatment with an anti-GP1balpha antibody, which depletes platelets, an anti-P-selectin antibody or a control antibody. Hepatic platelet and leukocyte recruitment as well as microvascular perfusion were determined by intravital fluorescence microscopy.Key results:BDL caused significant liver damage and sinusoidal perfusion failure. BDL further induced hepatic platelet accumulation with widespread intravascular platelet aggregates, increased platelet adhesion in postsinusoidal venules and massive platelet accumulation in liver sinusoids. Administration of the anti-GP1balpha antibody reduced systemic platelet count by 90%. Depletion of platelets in BDL mice not only abolished accumulation and adhesion of platelets in sinusoids and venules but also restored sinusoidal perfusion and reduced liver enzymes by more than 83%. Platelet depletion further reduced BDL-associated sinusoidal leukocyte accumulation by 48% although leukocyte-endothelium interactions in venules were not affected. Immunoneutralization of P-selectin also inhibited hepatic microvascular accumulation of platelets and leukocytes, and protected against cholestasis-provoked hepatocellular damage.Conclusions and implications:Platelets play an important role in BDL-induced liver injury by promoting leukocyte recruitment and deteriorating microvascular perfusion. Moreover, our findings demonstrate that cholestasis-induced accumulation of platelets is mediated by P-selectin. Thus, targeting platelet accumulation may be a useful strategy against liver damage associated with obstructive jaundice.British Journal of Pharmacology advance online publication, 19 November 2007; doi:10.1038/sj.bjp.0707578.
|
|
| 80. |
- Laschke, Matthias, et al.
(författare)
-
Rho-Kinase Inhibitor Attenuates Cholestasis-Induced CXC Chemokine Formation, Leukocyte Recruitment, and Hepatocellular Damage in the Liver.
- 2010
-
Ingår i: The Journal of surgical research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 159, s. 666-673
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In the present experimental study, we analyzed the role of Rho-kinase during obstructive cholestasis by studying the effect of the Rho-kinase inhibitor Y-27632 on hepatic CXC chemokine formation, leukocyte recruitment and hepatocellular damage. MATERIALS AND METHODS: C57BL/6 mice underwent bile duct ligation (BDL) to induce obstructive cholestasis. Mice were pretreated with Y-27632 (1 and 10mg/kg) or the vehicle PBS. Sham-operated animals served as controls. After 12h, hepatic accumulation of leukocytes and sinusoidal perfusion were determined using intravital fluorescence microscopy. Hepatocellular damage was monitored by measuring serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). CXC chemokines in the liver were analyzed by ELISA. RESULTS: Administration of 10mg/kg of Y-27632 protected against cholestasis-induced hepatocellular damage indicated by a more than 87% reduction of ALT and AST in BDL mice. Moreover, this Rho-kinase inhibitor significantly decreased BDL-induced production of CXC chemokines by 44-83% and leukocyte recruitment by 60%. Finally, treatment with Y-27632 restored sinusoidal perfusion in cholestatic animals. CONCLUSIONS: Our findings indicate that the Rho-kinase signaling pathway plays a key role in the pathophysiology of cholestatic liver injury. Thus, targeting Rho-kinase activity may represent a new therapeutic approach in the treatment of inflammation and liver injury in cholestatic liver diseases.
|
|
