| 1. |
- Paulsson, Kajsa M, et al.
(författare)
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Assembly of tapasin-associated MHC class I in the absence of the transporter associated with antigen processing (TAP)
- 2001
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 0953-8178 .- 1460-2377. ; 13:1, s. 9-23
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Tidskriftsartikel (refereegranskat)abstract
- The assembly of MHC class I molecules is regulated by a multi-protein complex in the endoplasmic reticules (ER) termed the loading complex. Tapasin is suggested to be one of the molecules forming this complex on the basis of its interaction with both the transporter associated with antigen processing (TAP) and MHC class I molecules. To address whether TAP is indispensable for the processing of the assembly of tapasin-associated MHC class I molecules, we studied the association of MHC class I molecules with tapasin, the assembly of tapasin-associated MHC class I with peptides and the peptide-mediated dissociation of MHC class I from tapasin in TAP-mutant T2 cells. In the absence of TAP, MHC class I heavy chain and beta(2)-microglobulin dimers were found to be properly associated with tapasin. The stable MHC class I dimer was required for its association with tapasin in the ER. In the absence of TAP, tapasin retained MHC class I molecules much longer in the ER than in the presence of TAP. This low off-rate of MHC class I from tapasin was due to the absence of high-affinity peptides in the ER of TAP-mutant cells but not to the absence of TAP per se. The introduction of peptides into permeabilized microsomes of TAP-mutant cells led to effective loading of the peptides onto tapasin-associated MHC class I and to the subsequent dissociation of MHC class I from tapasin. These results demonstrate that regulation of the assembly of tapasin-associated MHC class I is independent of the interaction of tapasin with TAP, but is dependent upon the peptides transported by TAP.
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| 2. |
- Sjögren, P., et al.
(författare)
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Medline search validity for randomised controlled trials in different areas of dental research
- 2002
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Ingår i: British Dental Journal. - 0007-0610 .- 1476-5373. ; 192:2, s. 97-99
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the validity of Medline searches for randomised controlled trials in dental research (RCT-Ds), using the medical subject headings (MeSH-terms). DESIGN: The Medline database was searched for randomised controlled trials in dental research (RCT-Ds) published in 1999 and with MeSH-terms corresponding to different areas of dental research. All RCT-Ds were manually examined for relevance to the different areas of dental research and cross-tabulated against the Medline search results. The sensitivity, specificity, positive (precision) and negative predictive values, as well as the accuracy of the search results were calculated. RESULTS: The highest validity in the Medline searches for RCT-Ds was seen for endodontics, followed by orthodontics, whereas the lowest validity was seen for pediatric dentistry and public health dentistry. For pediatric dentistry the MeSH-term searches had too low a sensitivity for adequate location of RCT-Ds. CONCLUSIONS: MeSH-term searches on Medline are a useful tool for rapid location of RCT-Ds in most areas of dental research. However, there is a vast variation in the search validity. More refined search strategies are required to locate RCT-Ds in areas of dental research with low search validity.
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| 3. |
- Sjögren, P., et al.
(författare)
-
Quality of reporting randomised clinical trials in dental and medical research
- 2002
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Ingår i: British Dental Journal. - 0007-0610 .- 1476-5373. ; 192:2, s. 100-103
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess 1) the quality of reporting randomised clinical trials in dental (RCT-Ds) and medical research (RCT-Ms), 2) the quality of RCT reports in relation to the journal impact factor, 3) the source of funding, and 4) the quality of RCT-Ds in different areas of dental research. DESIGN RANDOM: samples of 100 RCT-Ds and 100 RCT-Ms published in 1999 were evaluated for quality of reporting under blinded conditions with the Jadad quality assessment scale. In addition, correlation between the quality scores and journal impact factor or source of funding, as well as area of dental research were analysed. RESULTS: The quality of RCT-Ds and RCT-Ms published in 1999 was generally inadequate. The quality was largely equivalent in RCT-Ds and RCT-Ms. There was no correlation between the quality scores and the journal impact factor or the source of funding. Some differences were found in the quality scores between different areas of dental research. CONCLUSIONS: The results from these RCT-Ds and RCT-Ms show that most of them were imperfect in the reporting of methodology and trial conduct. There is a clear need to improve the quality of trial reporting in dental and medical research.
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| 4. |
- Wang, P, et al.
(författare)
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Inhibition of the transcription factors AP-1 and NF-kappaB in CD4 T cells by peroxisome proliferator-activated receptor gamma ligands
- 2001
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Ingår i: International Immunopharmacology. - 1567-5769. ; 1:4, s. 12-803
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Tidskriftsartikel (refereegranskat)abstract
- The peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear hormone receptor superfamily, is essential for adipocyte differentiation and glucose homeostasis. PPARgamma has been found recently to regulate macrophage activation in response to mitogens and inflammation. Our study shows PPARgamma to be preferentially expressed in the nuclei of resting T cells and to increase upon activation of T cells by either anti-CD3 and anti-CD28 or phorbol myristyl acetate (PMA). We also found the PPARgamma ligand ciglitizone to attenuate the activation of T cells by inhibiting cytokine gene expression and anti-CD3 and anti-CD28 or PMA-induced proliferative responses. Inhibition of both the proliferative response and inflammatory cytokine expression in CD4 T cells was correlated with suppression of the activated transcription factors AP1 and NF-kappaB. PPARgamma ligands also strongly inhibited SEA-induced Vbeta3 T cell activation in vivo. These results, together with previous findings of the inhibitory effect of PPARgamma ligands on activated macrophages, provide clear evidence for PPARgamma as a negative regulator of the inflammatory activation of both macrophage and T cells. PPARgamma may thus be a potential therapeutic target for the treatment of autoimmunity.
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| 5. |
- C Johansson, Anna, et al.
(författare)
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Computerized image analysis as a tool to quantify infiltrating leukocytes : a comparison between high- and low-magnification images
- 2001
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Ingår i: Journal of Histochemistry and Cytochemistry. - 0022-1554. ; 49:9, s. 79-1073
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present study was to establish a rapid and reproducible method for quantification of tissue-infiltrating leukocytes using computerized image analysis. To achieve this, the staining procedure, the image acquisition, and the image analysis method were optimized. Because of the adaptive features of the human eye, computerized image analysis is more sensitive to variations in staining compared with manual image analysis. To minimize variations in staining, an automated immunostainer was used. With a digital scanner camera, low-magnification images could be sampled at high resolution, thus making it possible to analyze larger tissue sections. Image analysis was performed by color thresholding of the digital images based on values of hue, saturation, and intensity color mode, which we consider superior to the red, green, and blue color mode for analysis of most histological stains. To evaluate the method, we compared computerized analysis of images with a x100 or a x12.5 magnification to assess leukocytes infiltrating rat brain tumors after peripheral immunizations with tumor cells genetically modified to express rat interferon-gamma (IFN-gamma) or medium controls. The results generated by both methods correlated well and did not show any significant differences. The method allows efficient and reproducible processing of large tissue sections that is less time-consuming than conventional methods and can be performed with standard equipment and software.(J Histochem Cytochem 49:1073-1079, 2001)
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| 6. |
- Chen, S, et al.
(författare)
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Functional association of cytokine-induced SH2 protein and protein kinase C in activated T cells
- 2003
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Ingår i: International Immunology. - : Oxford University Press (OUP). - 1460-2377. ; 15:3, s. 403-409
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Tidskriftsartikel (refereegranskat)abstract
- TCR signaling is mediated by intracellular signaling molecules and nuclear transcription factors, which are tightly regulated by interaction with regulatory proteins such as Grb2 and SLAP. We reported recently that TCR stimulation induces the expression of cytokine-induced SH2 protein (CIS). The expression of CIS promotes TCR-mediated activation. We have now found specific interactions between CIS and activated protein kinase C (PKC) alpha, beta and theta in TCR-stimulated T cells. CIS was shown by in vitro kinase assay to associate with activated PKC. In CIS-expressing T cells isolated from CIS-transgenic mice, the amount of activated PKC associated with CIS was found to increase following TCR stimulation. By immunohistochemical analysis, CIS was also found to co-localize with PKCtheta at the plasma membrane of activated T cells. In addition to the interaction and intracellular co-localization of the CIS and PKC, an increase in the activation of AP-1 and NF-kappaB was noted in CIS-expressing T cells, after stimulation by either anti-CD3/CD28 or phorbol myristate acetate + ionomycin. These results suggest that CIS regulates PKC activation, and that this may be important for the activation of both the AP-1 and NF-kappaB pathways in TCR signaling.
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| 7. |
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| 8. |
- Fu, Michael, 1963, et al.
(författare)
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Autoantibodies against the angiotensin receptor (AT1) in patients with hypertension.
- 2000
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Ingår i: Journal of hypertension. - 0263-6352. ; 18:7, s. 945-53
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Tidskriftsartikel (refereegranskat)abstract
- Sera from patients with malignant essential hypertension (n = 14), malignant secondary hypertension mainly attributable to renovascular diseases (n = 12) and renovascular diseases without malignant hypertension (n = 11) and from normotensive healthy blood donors (n = 35) were studied for the presence of autoantibodies against G-protein-coupled cardiovascular receptors. Autoantibodies against the angiotensin II receptor (AT1) were detected in 14, 33, 18 and 14% of patients with malignant essential hypertension, malignant secondary hypertension, renovascular diseases and control patients, respectively. Sensitivity of the enzyme immunoassay was assessed as 5 microg/ml IgG. Patients did not show antibodies against bradykinin (B2) or angiotensin II subtype 2 (AT2) receptors. Autoantibodies affinity-purified from positive patients localized AT receptors in Chinese hamster ovary transfected cells, and displayed a positive chronotropic effect on cultured neonatal rat cardiomyocytes. These results demonstrate the existence of autoantibodies against a functional extracellular domain of human AT1 receptors in patients with malignant hypertension, and suggest that these autoantibodies might be involved in the pathogenesis of malignant hypertension.
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| 9. |
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| 10. |
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| 11. |
- Larsson, Jörgen, et al.
(författare)
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Picosecond X-ray diffraction studies of laser-excited acoustic phonons in InSb
- 2002
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Ingår i: Applied Physics A: Materials Science & Processing. - : Springer Science and Business Media LLC. - 1432-0630 .- 0947-8396. ; 75:4, s. 467-478
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Tidskriftsartikel (refereegranskat)abstract
- We have employed time-resolved X-ray diffraction with picosecond temporal resolution to measure the time-dependent rocking curves of laser-irradiated asymmetrically cut single InSb crystals. Coherent acoustic phonons were excited in the crystals by irradiation with 800-nm, 100-fs laser pulses at irradiances between 0.25 and 12 mJ/cm(2). The induced time-dependent strain profiles (corresponding to the coherent phonons) were monitored by diffracting collimated, monochromatic pulses Of X-rays from the irradiated crystals. Recording of the diffracted radiation with a fast low-jitter X-ray streak camera resulted in an overall temporal resolution of better than 2 ps. The strain associated with the coherent phonons modifies the rocking curve of the crystal in a time-dependent manner, and the rocking curve is recorded by keeping the angle of incidence of the X-rays upon the crystal fixed, but varying the energy of the incident X-rays around a central energy of 8.453 keV (corresponding to the peak of the rocking curve of the unperturbed crystal). The observed time-dependent diffraction from the irradiated crystals is in reasonable agreement with simulations over a wide range of energies from the unperturbed rocking-curve peak.
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| 12. |
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| 13. |
- Sjögren, M, et al.
(författare)
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CSF levels of tau, beta-amyloid and GAP-43 in frontotemporal 1-42 dementia, other types of dementia and normal aging
- 2000
-
Ingår i: Journal of neural transmission. - 0300-9564 .- 1435-1463. ; 107:5, s. 563-579
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) levels of tau, ▀-amyloid1-42 and growth-associated protein 43 (GAP-43) were studied in patients with frontotemporal dementia (FTD, n = 17), Alzheimer's disease (AD, n = 60), subcortical white-matter dementia (SWD, n = 24), Parkinson's disease (PD, n = 23) and dysthymia (n = 19) and in age-matched controls (n = 32). CSF-tau was significantly increased only in AD, and CSF-▀-amyloid1-42 was significantly decreased in AD and SWD as compared to controls, and in AD compared to FTD. CSF-GAP-43 was significantly decreased only in PD. The GAP-43/tau ratio was decreased in all the patient groups except the dysthymia group compared to controls. A positive correlation was found between CSF-GAP-43 and CSF-tau in all groups. The results suggest normal levels of CSF-tau and CSF-▀-amyloid1-42 in FTD, which will aid in the clinical separation of FTD from AD. In SWD, decreased levels of CSF-▀-amyloid1-42 suggest concomitant involvement of vascular and amyloid protein mechanisms.
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| 14. |
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| 15. |
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| 16. |
- Sjögren, P., et al.
(författare)
-
Medline search validity for randomised controlled trials in different areas of dental research
- 2002
-
Ingår i: British Dental Journal. - : Nature Publishing Group. - 0007-0610 .- 1476-5373. ; 192:2, s. 97-99
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the validity of Medline searches for randomised controlled trials in dental research (RCT-Ds), using the medical subject headings (MeSH-terms). DESIGN: The Medline database was searched for randomised controlled trials in dental research (RCT-Ds) published in 1999 and with MeSH-terms corresponding to different areas of dental research. All RCT-Ds were manually examined for relevance to the different areas of dental research and cross-tabulated against the Medline search results. The sensitivity, specificity, positive (precision) and negative predictive values, as well as the accuracy of the search results were calculated. RESULTS: The highest validity in the Medline searches for RCT-Ds was seen for endodontics, followed by orthodontics, whereas the lowest validity was seen for pediatric dentistry and public health dentistry. For pediatric dentistry the MeSH-term searches had too low a sensitivity for adequate location of RCT-Ds. CONCLUSIONS: MeSH-term searches on Medline are a useful tool for rapid location of RCT-Ds in most areas of dental research. However, there is a vast variation in the search validity. More refined search strategies are required to locate RCT-Ds in areas of dental research with low search validity.
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| 17. |
- Sjögren, P., et al.
(författare)
-
Quality of reporting randomised clinical trials in dental and medical research
- 2002
-
Ingår i: British Dental Journal. - : Nature Publishing Group. - 0007-0610 .- 1476-5373. ; 192:2, s. 100-103
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess 1) the quality of reporting randomised clinical trials in dental (RCT-Ds) and medical research (RCT-Ms), 2) the quality of RCT reports in relation to the journal impact factor, 3) the source of funding, and 4) the quality of RCT-Ds in different areas of dental research. DESIGN RANDOM: samples of 100 RCT-Ds and 100 RCT-Ms published in 1999 were evaluated for quality of reporting under blinded conditions with the Jadad quality assessment scale. In addition, correlation between the quality scores and journal impact factor or source of funding, as well as area of dental research were analysed. RESULTS: The quality of RCT-Ds and RCT-Ms published in 1999 was generally inadequate. The quality was largely equivalent in RCT-Ds and RCT-Ms. There was no correlation between the quality scores and the journal impact factor or the source of funding. Some differences were found in the quality scores between different areas of dental research. CONCLUSIONS: The results from these RCT-Ds and RCT-Ms show that most of them were imperfect in the reporting of methodology and trial conduct. There is a clear need to improve the quality of trial reporting in dental and medical research.
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| 18. |
- Sjögren, Torsten, et al.
(författare)
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High Performance Piston Rings for Two-Stroke Marine Diesel Engines
- 2004
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Ingår i: Proceedings // 24th CIMAC World Congress on Combustion Engine Technology.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The piston ring is a key component in a marine combustion engine. High mechanical loads, relatively high temperatures and corrosive gases and liquids influence its performance in terms of sealing capacity, wear of cylinder liner and the ring itself. Base material of the ring, coating technology and ring geometry design are discussed in the article.When tailoring cast iron materials suitable as piston ring base material two parameters are of importance; the morphology of the graphite and the constituents of the matrix. To optimize the properties of the cast iron a compromise is needed to achieve a satisfactory performance of the piston rings.Daros Piston Rings AB is currently developing a second generation of chromium-ceramic coating the so called Z-chrome. The objective of this project has been to increase the maximum operating temperature of the coating and leave the other characteristics of the coating unaffected. The difference between the commercial Daros coating Tritor® and the Z-chrome is the ceramic component included in the coated layer.Insufficient conformability of piston ring and liner geometry may produce a large local cylinder wall pressure which will destroy the oil film leading to uncontrolled wear and scuffing. Lack of conformability can also produce leakage paths for the combustion gases. Therefore a correct ring shape is of utmost importance. A new design philosophy designated OPCORE® has been developed and is presented here.
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| 19. |
- Tallheden, Tommi, 1972, et al.
(författare)
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Phenotypic plasticity of human articular chondrocytes.
- 2003
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Ingår i: The Journal of bone and joint surgery. American volume. - 0021-9355. ; 85-A Suppl 2, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- Progenitor cells in mesenchymal tissues are important in the maintenance of tissue homeostasis and regeneration capacity. Articular cartilage is a tissue with a very low capacity for repair. One explanation could be the lack of chondrogenic progenitor cells within the adult tissue. As a test of chondrogenic differentiation potential, we examined the ability of isolated chondrocytes to take on several phenotypic identities within the mesenchymal lineage by applying culture techniques and markers used in the study of the phenotypic plasticity of marrow-derived mesenchymal stem cells (MSCs).
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| 20. |
- Tranberg, Karl-Göran, et al.
(författare)
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Interstitial laser hyperthermia of a rat liver adenocarcinoma
- 2002
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Ingår i: Journal of X-Ray Science and Technology. - 0895-3996. ; 10:3-4, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was implanted into the left lateral lobe of the rat liver, and treatment was performed 8 days later. Rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46°C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection, with no difference in local control. Using inoculation of tumour cell suspensions into the lateral and the median lobes of the liver simultaneously and treating the lateral lobe tumour only, we found that laser thermotherapy reduced take and growth of the untreated tumour in the median lobe indicating that laser thermotherapy may induce immunologic effects. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour as compared to resection. It is suggested that this can be at least partly explained by a laser-induced immunologic effect.
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| 21. |
- Tranberg, K G, et al.
(författare)
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Interstitial laser thermotherapy of a rat liver adenocarcinoma
- 2002
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Ingår i: Journal of X-Ray Science and Technology. - 0895-3996. ; 10:3, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to compare interstitial laser thermotherapy with excision of a liver tumour. A dimethylhydrazine-induced adenocarcinoma was implanted into the left lateral lobe of the rat liver, and treatment was performed 8 days later. Rats were treated with resection of the tumour-bearing lobe or underwent interstitial laser thermotherapy, which was performed at a steady-state temperature of 46°C for 30 min, 3 mm from the tumour margin. The incidence and extent of intraperitoneal spread was smaller after laser thermotherapy than after resection, with no difference in local control. Using inoculation of tumour cell suspensions into the lateral and the median lobes of the liver simultaneously and treating the lateral lobe tumour only, we found that laser thermotherapy reduced take and growth of the untreated tumour in the median lobe indicating that laser thermotherapy may induce immunologic effects. It is concluded that interstitial laser thermotherapy reduces spread of liver tumour as compared to resection. It is suggested that this can be at least partly explained by a laser-induced immunologic effect.
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| 22. |
- Visse, E, et al.
(författare)
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Immunohistochemical analysis of glioma-infiltrating leucocytes after peripheral therapeutic immunization with interferon-gamma-transfected glioma cells
- 2000
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Ingår i: Cancer Immunology and Immunotherapy. - : Springer Science and Business Media LLC. - 1432-0851 .- 0340-7004. ; 49:3, s. 142-151
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Tidskriftsartikel (refereegranskat)abstract
- We have shown previously that rejection of preinduced rat brain tumours is possible following therapeutic immunizations with interferon-gamma (IFN gamma)-transfected glioma cells (N32-IFN gamma). In the present study we have used the same model to evaluate whether quantitative differences in tumour-infiltrating lymphocytes can be detected between animals receiving therapeutic immunizations with either IFN gamma-transfected glioma cells, wild-type glioma cells or no treatment. Since leucocyte transpedesis into the tumour can be anticipated to depend on the state of vascularization, we have mapped the development of microvessels in the tumour in parallel with the leucocyte infiltration. Our results show that microvessels start to form at day 7 and then gradually increase in number and size, indicating the establishment of an extensive vascularization by day 24. Leucocyte infiltration displays a biphasic pattern after tumour grafting. We have therefore studied the infiltration kinetics after an early immunization (1 day after intracerebral isografting) and compared the effects with those of a late immunization (10 days after intracerebral isografting) with N32-IFN gamma or wild-type N32. Our results show (1) an early infiltration of granulocytes 3 days after isografting; (2) a T-cell-receptor-positive (TCR+) T-cell infiltration starting on day 10; (3) a macrophage infiltration starting on day 13; (4) a CD8+ cell infiltration starting on day 13. The proportions of TCR+ T cells, CD8+ cells and natural killer cells differs significantly between animals immunized with N32-IFN gamma and those receiving wild-type N32, when analysed 14 days after immunization at day 10. This difference can only be detected when animals are immunized at later stages of tumour growth. We propose that this could depend on an early-immunization-independent leucocyte infiltration during tumour establishment. This has to be considered when evaluating studies of leucocyte infiltration in experimental tumours.
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