| 1. |
- Bailey, D. L., et al.
(författare)
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Combined PET/MRI : Global Warming-Summary Report of the 6th International Workshop on PET/MRI, March 27-29, 2017, Tubingen, Germany
- 2018
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Ingår i: Molecular Imaging and Biology. - : SPRINGER. - 1536-1632 .- 1860-2002. ; 20:1, s. 4-20
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Forskningsöversikt (refereegranskat)abstract
- The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tubingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how best to characterise the tumour microenvironment, optimise the complementary information available from PET and MRI, and how advanced data mining and bioinformatics, as well as information from liquid biomarkers (circulating tumour cells and nucleic acids) and pathology, can be integrated to give a more complete characterisation of disease phenotype. Some issues that have dominated previous meetings, such as the accuracy of MR-based attenuation correction (AC) of the PET scan, were finally put to rest as having been adequately addressed for the majority of clinical situations. Likewise, the ability to standardise PET systems for use in multicentre trials was confirmed, thus removing a perceived barrier to larger clinical imaging trials. The meeting openly questioned whether PET/MRI should, in all cases, be used as a whole-body imaging modality or whether in many circumstances it would best be employed to give an in-depth study of previously identified disease in a single organ or region. The meeting concluded that there is still much work to be done in the integration of data from different fields and in developing a common language for all stakeholders involved. In addition, the participants advocated joint training and education for individuals who engage in routine PET/MRI. It was agreed that PET/MRI can enhance our understanding of normal and disrupted biology, and we are in a position to describe the in vivo nature of disease processes, metabolism, evolution of cancer and the monitoring of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.
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| 2. |
- Eekers, Danielle B. P., et al.
(författare)
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The EPTN consensus-based atlas for CT- and MR-based contouring in neuro-oncology
- 2018
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Ingår i: Radiotherapy and Oncology. - : ELSEVIER IRELAND LTD. - 0167-8140 .- 1879-0887. ; 128:1, s. 37-43
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To create a digital, online atlas for organs at risk (OAR) delineation in neuro-oncology based on high-quality computed tomography (Cr) and magnetic resonance (MR) imaging. Methods: CT and 3 Tesla (3T) MR images (slice thickness 1 mm with intravenous contrast agent) were obtained from the same patient and subsequently fused. In addition, a 7T MR without intravenous contrast agent was obtained from a healthy volunteer. Based on discussion between experienced radiation oncologists, the clinically relevant organs at risk (OARs) to be included in the atlas for neuro-oncology were determined, excluding typical head and neck OARs previously published. The draft atlas was delineated by a senior radiation oncologist, 2 residents in radiation oncology, and a senior neuro-radiologist incorporating relevant available literature. The proposed atlas was then critically reviewed and discussed by European radiation oncologists until consensus was reached. Results: The online atlas includes one CT-scan at two different window settings and one MR scan (3T) showing the OARs in axial, coronal and sagittal view. This manuscript presents the three-dimensional descriptions of the fifteen consensus OARs for neuro-oncology. Among these is a new OAR relevant for neuro-cognition, the posterior cerebellum (illustrated on 7T MR images). Conclusion: In order to decrease inter- and intra-observer variability in delineating OARs relevant for neuro-oncology and thus derive consistent dosimetric data, we propose this atlas to be used in photon and particle therapy. The atlas is available online at w.cancerdata.c and will be updated whenever required.
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| 3. |
- Hamer, H. M., et al.
(författare)
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Analyses of human colonic mucus obtained by an in vivo sampling technique
- 2009
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Ingår i: Digestive and Liver Disease. - Amsterdam : W.B. Saunders Co. Ltd.. - 1590-8658 .- 1878-3562. ; 41:8, s. 559-564
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The mucus layer is an important dynamic component of the epithelial barrier. It contains mucin glycoproteins and other compounds secreted by the intestinal epithelium, such as secretory IgA. However, a standardized in vivo sampling technique of mucus in humans is not yet available.AIM: To assess the validity and feasibility of mucin and protein determinations in human colonic mucus collected under physiological conditions.SUBJECTS AND METHODS: Triplicate colonic mucus samples were collected in 11 healthy volunteers using cytology brushes during sigmoidoscopy. As an indication of the quantity of collected mucus, total protein and mucin concentrations were determined by measuring oligosaccharide equivalents and monosaccharides. Also secretory IgA and sialic acid concentrations were determined and proteomic analysis was performed using surface enhanced laser desorption/ionization-time of flight-mass spectrometry.RESULTS: Mean values of secretory IgA and sialic acid corrected for the amount of mucus ranged from 0.16 to 1.81g secretory IgA/mmol oligosaccharide equivalents and from 12.6 to 48.6g sialic acid/mmol oligosaccharide equivalents. Proteomic analysis of mucus is feasible and cluster analysis showed subject specific profiles. CONCLUSION: Using cytology brushes, human colonic mucus can be sampled and under physiological conditions. These samples could give information on the composition and quality of the mucus layer.
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| 4. |
- Hamer, Henrike M., et al.
(författare)
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Butyrate enemas do not affect human colonic MUC2 and TFF3 expression
- 2010
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Ingår i: European Journal of Gastroenterology and Hepathology. - 0954-691X .- 1473-5687. ; 22:9, s. 1134-1140
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The colonic mucus layer plays an important role in the protection of the intestinal epithelium and mainly consists of mucin glycoproteins (primarily MUC2 in the colon) trefoil factor 3 (TFF3) and secretory IgA. Butyrate is a major end product of fermentation of dietary fibres and is associated with beneficial effects on colonic health. Earlier in-vitro and animal studies showed that butyrate modulates MUC2 and TFF3 expression and mucin secretion, although data from human studies are not yet available. Methods Sixteen healthy volunteers and 35 ulcerative colitis (UC) patients in clinical remission self-administered a 60 ml rectal enema containing 100 mmol/l butyrate or placebo once daily for 2 and 3 weeks, respectively. After each treatment, biopsies were taken from the distal sigmoid for quantitative RT-PCR and immunohistochemical analysis of MUC2 and TFF3. In addition, mucosal sections were stained with high iron diamine-alcian blue to distinguish between sialomucins and sulphomucins. To analyse total mucin secretion and secretory IgA concentrations, 24 h faeces were collected during the day before the endoscopic examination. Results The butyrate intervention did not significantly modulate the expression of MUC2 ( fold change: 1.04 and 1.05 in healthy volunteers and ulcerative colitis patients, respectively) or TFF3 (fold change: 0.91 and 0.94 in healthy volunteers and UC patients, respectively). Furthermore, the percentage of sialomucins, mucus secretion and secretory IgA concentrations were not affected by the butyrate intervention in both the groups. Conclusion Butyrate exposure in healthy volunteers and UC patients in remission did not affect the measured parameters of the colonic mucus layer. Eur J Gastroenterol Hepatol 22: 1134-1140 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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| 5. |
- Hamer, Henrike M., et al.
(författare)
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Butyrate modulates oxidative stress in the colonic mucosa of healthy humans
- 2009
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Ingår i: Clinical Nutrition. - Amsterdam : Churchill Livingstone. - 0261-5614 .- 1532-1983. ; 28:1, s. 88-93
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Butyrate, a short-chain fatty acid produced by colonic microbial fermentation of undigested carbohydrates, has been implicated in the maintenance of colonic health. This study evaluates whether butyrate plays a role in oxidative stress in the healthy colonic mucosa. METHODS: A randomized, double blind, cross-over study with 16 healthy volunteers was performed. Treatments consisted of daily rectal administration of a 60 ml enema containing 100 mM sodium butyrate or saline for 2 weeks. After each treatment, a blood sample was taken and mucosal biopsies were obtained from the sigmoid colon. In biopsies, the trolox equivalent antioxidant capacity, activity of glutathione-S-transferase, concentration of uric acid, glutathione (GSH), glutathione disulfide and malondialdehyde, and expression of genes involved in GSH and uric acid metabolism was determined. Secondary outcome parameters were CRP, calprotectin and intestinal fatty acid binding protein in plasma and histological inflammatory scores. RESULTS: Butyrate treatment resulted in significantly higher GSH (p<0.05) and lower uric acid (p<0.01) concentrations compared to placebo. Changes in GSH and uric acid were accompanied by increased and decreased expression, respectively, of their rate limiting enzymes determined by RT-PCR. No significant differences were found in other parameters. CONCLUSIONS: This study demonstrated that butyrate is able to beneficially affect oxidative stress in the healthy human colon.
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| 6. |
- Hamer, Henrike M., et al.
(författare)
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Effect of butyrate enemas on inflammation and antioxidant status in the colonic mucosa of patients with ulcerative colitis in remission
- 2010
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Ingår i: Clinical Nutrition. - Amsterdam, Netherlands : Elsevier. - 0261-5614 .- 1532-1983. ; 29:6, s. 738-744
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Butyrate, produced by colonic fermentation of dietary fibers is often hypothesized to beneficially affect colonic health. This study aims to assess the effects of butyrate on inflammation and oxidative stress in subjects with chronically mildly elevated parameters of inflammation and oxidative stress.Methods: Thirty-five patients with ulcerative colitis in clinical remission daily administered 60 ml rectal enemas containing WO mM sodium butyrate (n = 17) or saline (n = 18) during 20 days (NCT00696098). Before and after the intervention feces, blood and colonic mucosal biopsies were obtained. Parameters of antioxidant defense and oxidative damage, myeloperoxidase, several cytokines, fecal calprotectin and CRP were determined.Results: Butyrate enemas induced minor effects on colonic inflammation and oxidative stress. Only a significant increase of the colonic IL-10/IL-12 ratio was found within butyrate-treated patients (p = 0.02), and colonic concentrations of CCL5 were increased after butyrate compared to placebo treatment (p = 0.03). Although in general butyrate did not affect colonic glutathione levels, the effects of butyrate enemas on total colonic glutathione appeared to be dependent on the level of inflammation.Conclusion: Although UC patients in remission were characterized by low-grade oxidative stress and inflammation, rectal butyrate enemas showed only minor effects on inflammatory and oxidative stress parameters.
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| 7. |
- Unkelbach, Jan, et al.
(författare)
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The role of computational methods for automating and improving clinical target volume definition
- 2020
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 153, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- Treatment planning in radiotherapy distinguishes three target volume concepts: the gross tumor volume(GTV), the clinical target volume (CTV), and the planning target volume (PTV). Over time, GTV definitionand PTV margins have improved through the development of novel imaging techniques and better imageguidance, respectively. CTV definition is sometimes considered the weakest element in the planning pro-cess. CTV definition is particularly complex since the extension of microscopic disease cannot be seenusing currently available in-vivo imaging techniques. Instead, CTV definition has to incorporate knowl-edge of the patterns of tumor progression. While CTV delineation has largely been considered the domainof radiation oncologists, this paper, arising from a 2019 ESTRO Physics research workshop, discusses thecontributions that medical physics and computer science can make by developing computational meth-ods to support CTV definition. First, we overview the role of image segmentation algorithms, which mayin part automate CTV delineation through segmentation of lymph node stations or normal tissues repre-senting anatomical boundaries of microscopic tumor progression. The recent success of deep convolu-tional neural networks has also enabled learning entire CTV delineations from examples. Second, wediscuss the use of mathematical models of tumor progression for CTV definition, using as example theapplication of glioma growth models to facilitate GTV-to-CTV expansion for glioblastoma that is consis-tent with neuroanatomy. We further consider statistical machine learning models to quantify lymphaticmetastatic progression of tumors, which may eventually improve elective CTV definition. Lastly, we dis-cuss approaches to incorporate uncertainty in CTV definition into treatment plan optimization as well asgeneral limitations of the CTV concept in the case of infiltrating tumors without natural boundaries.
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| 8. |
- van Baarlen, Peter, et al.
(författare)
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Differential NF-κB pathways induction by Lactobacillus plantarum in the duodenum of healthy humans correlating with immune tolerance
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - Washington, DC : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:7, s. 2371-2376
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Tidskriftsartikel (refereegranskat)abstract
- How do we acquire immune tolerance against food microorganisms and commensal bacteria that constitute the intestinal microbiota? We investigated this by stimulating the immune system of adults with commensal Lactobacillus plantarum bacteria. We studied the in vivo human responses to L. plantarum in a randomized double-blind placebo-controlled cross-over study. Healthy adults ingested preparations of living and heat-killed L. plantarum bacteria. Biopsies were taken from the intestinal duodenal mucosa and altered expression profiles were analyzed using whole-genome microarrays and by biological pathway reconstructions. Expression profiles of human mucosa displayed striking differences in modulation of NF-kappaB-dependent pathways, notably after consumption of living L. plantarum bacteria in different growth phases. Our in vivo study identified mucosal gene expression patterns and cellular pathways that correlated with the establishment of immune tolerance in healthy adults.
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| 9. |
- van Dessel, L., et al.
(författare)
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Pulmonary Hemodynamics and Outcome in a Large Cohort of Patients with Sinus Venosus Septal Defect
- 2020
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Ingår i: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X. ; 15:2, s. 69-78
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Tidskriftsartikel (refereegranskat)abstract
- Background: Left-to-right shunt in sinus venosus septal defect (SVSD) may affect resistive (pulmonary vascular resistance-PVR) and elastic (pulmonary artery compliance-PAC) pulmonary artery properties. This study aimed at evaluating (1) impact of age, (2) pulmonary hemodynamics, and (3) outcome in a large cohort of SVSD patients. Methods: This study included 136 patients with SVSD (median age at diagnosis 14 (IQR 5-48) years, 47% male) of which 87 underwent catheterization. Pressures were measured and cardiac output was evaluated using the Fick principle at diagnosis. PVR, PAC and their product (RC time) were calculated. Results: Surgical repair was performed in 128 (94%) at a median age of 13 (IQR 5- 43) years. During a median follow-up time of 31 (IQR 17-55) years, 12 (9%) patients died, 13 (10%) developed heart failure, 4 (3%) Eisenmenger syndrome, 19 (14%) atrial arrhythmia, 6 (4%) sick sinus syndrome and 7 (5%) required pacemaker implantation In those who underwent catheterization, median shunt ratio was 2.5 (IQR 2.0-2.9). Thirty (34%) had mean PA pressure >= 25 mmHg. PVR indexed, PAC indexed, and RC time was 3.5 (IQR 2.4-7.5) WU.m(2) , 1.8 (IQR 1.3-2.5) mL/mmHg.m(2) and 0.39 (0.26-0.53) sec with an inverse hyperbolic relationship between PVR and PAC. Mean PA pressure (P < 0.0001); wedge pressure (P = 0.001), PVR indexed (P = 0.002) and PAC indexed (P = 0.002) changed significantly with age at diagnosis, but shunt ratio did not. Conclusion: SVSD has good long-term outcome, albeit with late morbidities. Thirty-four percent has mean PA pressure >= 25 mmHg, but Eisenmenger syndrome is rare (3%). PVR and PAC are inversely related and change significantly with older age.
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| 10. |
- van Gorp, Charlotte, et al.
(författare)
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Antenatal Ureaplasma Infection Causes Colonic Mucus Barrier Defects: Implications for Intestinal Pathologies
- 2024
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Ingår i: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - 1661-6596 .- 1422-0067. ; 25:7
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Tidskriftsartikel (refereegranskat)abstract
- Chorioamnionitis is a risk factor for necrotizing enterocolitis (NEC). Ureaplasma parvum (UP) is clinically the most isolated microorganism in chorioamnionitis, but its pathogenicity remains debated. Chorioamnionitis is associated with ileal barrier changes, but colonic barrier alterations, including those of the mucus barrier, remain under-investigated, despite their importance in NEC pathophysiology. Therefore, in this study, the hypothesis that antenatal UP exposure disturbs colonic mucus barrier integrity, thereby potentially contributing to NEC pathogenesis, was investigated. In an established ovine chorioamnionitis model, lambs were intra-amniotically exposed to UP or saline for 7 d from 122 to 129 d gestational age. Thereafter, colonic mucus layer thickness and functional integrity, underlying mechanisms, including endoplasmic reticulum (ER) stress and redox status, and cellular morphology by transmission electron microscopy were studied. The clinical significance of the experimental findings was verified by examining colon samples from NEC patients and controls. UP-exposed lambs have a thicker but dysfunctional colonic mucus layer in which bacteria-sized beads reach the intestinal epithelium, indicating undesired bacterial contact with the epithelium. This is paralleled by disturbed goblet cell MUC2 folding, pro-apoptotic ER stress and signs of mitochondrial dysfunction in the colonic epithelium. Importantly, the colonic epithelium from human NEC patients showed comparable mitochondrial aberrations, indicating that NEC-associated intestinal barrier injury already occurs during chorioamnionitis. This study underlines the pathogenic potential of UP during pregnancy; it demonstrates that antenatal UP infection leads to severe colonic mucus barrier deficits, providing a mechanistic link between antenatal infections and postnatal NEC development.
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