172 research outputs found

    Matrix Metalloproteinase 13 Is Induced in Fibroblasts in Polyomavirus Middle T Antigen-Driven Mammary Carcinoma without Influencing Tumor Progression

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    Matrix metalloproteinase (MMP) 13 (collagenase 3) is an extracellular matrix remodeling enzyme that is induced in myofibroblasts during the earliest invasive stages of human breast carcinoma, suggesting that it is involved in tumor progression. During progression of mammary carcinomas in the polyoma virus middle T oncogene mouse model (MMTV-PyMT), Mmp13 mRNA was strongly upregulated concurrently with the transition to invasive and metastatic carcinomas. As in human tumors, Mmp13 mRNA was found in myofibroblasts of invasive grade II and III carcinomas, but not in benign grade I and II mammary intraepithelial neoplasias. To determine if MMP13 plays a role in tumor progression, we crossed MMTV-PyMT mice with Mmp13 deficient mice. The absence of MMP13 did not influence tumor growth, vascularization, progression to more advanced tumor stages, or metastasis to the lungs, and the absence of MMP13 was not compensated for by expression of other MMPs or tissue inhibitor of metalloproteinases. However, an increased fraction of thin collagen fibrils was identified in MMTV-PyMT;Mmp13−/− compared to MMTV-PyMT;Mmp13+/+ tumors, showing that collagen metabolism was altered in the absence of MMP13. We conclude that the expression pattern of Mmp13 mRNA in myofibroblasts of invasive carcinomas in the MMTV-PyMT breast cancer model recapitulates the expression pattern observed in human breast cancer. Our results suggest that MMP13 is a marker of carcinoma-associated myofibroblasts of invasive carcinoma, even though it does not make a major contribution to tumor progression in the MMTV-PyMT breast cancer model

    Metabolomic phenotyping of a cloned pig model

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    <p>Abstract</p> <p>Background</p> <p>Pigs are widely used as models for human physiological changes in intervention studies, because of the close resemblance between human and porcine physiology and the high degree of experimental control when using an animal model. Cloned animals have, in principle, identical genotypes and possibly also phenotypes and this offer an extra level of experimental control which could possibly make them a desirable tool for intervention studies. Therefore, in the present study, we address how phenotype and phenotypic variation is affected by cloning, through comparison of cloned pigs and normal outbred pigs.</p> <p>Results</p> <p>The metabolic phenotype of cloned pigs (n = 5) was for the first time elucidated by nuclear magnetic resonance (NMR)-based metabolomic analysis of multiple bio-fluids including plasma, bile and urine. The metabolic phenotype of the cloned pigs was compared with normal outbred pigs (n = 6) by multivariate data analysis, which revealed differences in the metabolic phenotypes. Plasma lactate was higher for cloned vs control pigs, while multiple metabolites were altered in the bile. However a lower inter-individual variability for cloned pigs compared with control pigs could not be established.</p> <p>Conclusions</p> <p>From the present study we conclude that cloned and normal outbred pigs are phenotypically different. However, it cannot be concluded that the use of cloned animals will reduce the inter-individual variation in intervention studies, though this is based on a limited number of animals.</p

    Snowpack fluxes of methane and carbon dioxide from high Arctic tundra

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    Measurements of the land-atmosphere exchange of the greenhouse gases methane (CH4) and carbon dioxide (CO2) in high Arctic tundra ecosystems are particularly difficult in the cold season, resulting in large uncertainty on flux magnitudes and their controlling factors during this long, frozen period. We conducted snowpack measurements of these gases at permafrost-underlain wetland sites in Zackenberg Valley (NE Greenland, 74°N) and Adventdalen Valley (Svalbard, 78°N), both of which also feature automatic closed chamber flux measurements during the snow-free period. At Zackenberg, cold season emissions were 1 to 2 orders of magnitude lower than growing season fluxes. Perennially, CH4 fluxes resembled the same spatial pattern, which was largely attributed to differences in soil wetness controlling substrate accumulation and microbial activity. We found no significant gas sinks or sources inside the snowpack but detected a pulse in the δ13C-CH4 stable isotopic signature of the soil's CH4 source during snowmelt, which suggests the release of a CH4 reservoir that was strongly affected by methanotrophic microorganisms. In the polygonal tundra of Adventdalen, the snowpack featured several ice layers, which suppressed the expected gas emissions to the atmosphere, and conversely lead to snowpack gas accumulations of up to 86 ppm CH4 and 3800 ppm CO2 by late winter. CH4 to CO2 ratios indicated distinctly different source characteristics in the rampart of ice-wedge polygons compared to elsewhere on the measured transect, possibly due to geomorphological soil cracks. Collectively, these findings suggest important ties between growing season and cold season greenhouse gas emissions from high Arctic tundra

    Feasibility of a standardized ultrasound examination in patients with rheumatoid arthritis: A quality improvement among rheumatologists cohort.

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    BACKGROUND: Quality improvement is important to facilitate valid patient outcomes. Standardized examination procedures may improve the validity of US. The aim of this study was to investigate the learning progress for rheumatologists during training of US examination of the hand in patients with rheumatoid arthritis (RA). METHODS: Rheumatologists with varying degrees of experience in US were instructed by skilled tutors. The program consisted of two days with hands-on training followed by personal US examinations performed in their individual clinics. Examinations were sent to the tutors for quality control. The US examinations were evaluated according to a scoring sheet containing 144 items. An acceptable examination was defined as > 80% correct scores. RESULTS: Thirteen rheumatologists participated in the study. They included a total of 104 patients with RA. Only few of the initial examinations were scored below 80%, and as experience increased, the scores improved (p = 0.0004). A few participants displayed decreasing scores. The mean time spent performing the standardized examination procedure decreased from 34 min to less than 10 minutes (p = 0.0001). CONCLUSION: With systematic hands-on training, a rheumatologist can achieve a high level of proficiency in the conduction of US examinations of the joints of the hand in patients with RA. With experience, examination time decreases, while the level of correctness is maintained. The results indicate that US may be applied as a valid measurement tool suitable for clinical practice and in both single- and multi-centre trials

    Therapeutic hypothermia for acute ischaemic stroke. Results of a European multicentre, randomised, phase III clinical trial

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    Introduction: We assessed whether modest systemic cooling started within 6 hours of symptom onset improves functional outcome at three months in awake patients with acute ischaemic stroke. Patients and methods: In this European randomised open-label clinical trial with blinded outcome assessment, adult patients with acute ischaemic stroke were randomised to cooling to a target body temperature of 34.0–35.0°C, started within 6 h after stroke onset and maintained for 12 or 24 h, versus standard treatment. The primary outcome was the score on the modified Rankin Scale at 91 days, as analysed with ordinal logistic regression. Results: The trial was stopped after inclusion of 98 of the originally intended 1500 patients because of slow recruitment and cessation of funding. Forty-nine patients were randomised to hypothermia versus 49 to standard treatment. Four patients were lost to follow-up. Of patients randomised to hypothermia, 15 (31%) achieved the predefined cooling targets. The primary outcome did not differ between the groups (odds ratio for good outcome, 1.01; 95% confidence interval, 0.48–2.13; p = 0.97). The number of patients with one or more serious adverse events did not differ between groups (relative risk, 1.22; 95% confidence interval, 0.65–1.94; p = 0.52). Discussion: In this trial, cooling to a target of 34.0–35.0°C and maintaining this for 12 or 24 h was not feasible in the majority of patients. The final sample was underpowered to detect clinically relevant differences in outcomes. Conclusion: Before new trials are launched, the feasibility of cooling needs to be improved

    Improving economic evaluations in stroke : A report from the ESO Health Economics Working Group

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    Introduction Approaches to economic evaluations of stroke therapies are varied and inconsistently described. An objective of the European Stroke Organisation (ESO) Health Economics Working Group is to standardise and improve the economic evaluations of interventions for stroke. Methods The ESO Health Economics Working Group and additional experts were contacted to develop a protocol and a guidance document for data collection for economic evaluations of stroke therapies. A modified Delphi approach, including a survey and consensus processes, was used to agree on content. We also asked the participants about resources that could be shared to improve economic evaluations of interventions for stroke. Results Of 28 experts invited, 16 (57%) completed the initial survey, with representation from universities, government, and industry. More than half of the survey respondents endorsed 13 specific items to include in a standard resource use questionnaire. Preferred functional/quality of life outcome measures to use for economic evaluations were the modified Rankin Scale (14 respondents, 88%) and the EQ-5D instrument (11 respondents, 69%). Of the 12 respondents who had access to data used in economic evaluations, 10 (83%) indicated a willingness to share data. A protocol template and a guidance document for data collection were developed and are presented in this article. Conclusion The protocol template and guidance document for data collection will support a more standardised and transparent approach for economic evaluations of stroke care.Peer reviewe

    Prevention of haematoma progression by tranexamic acid in intracerebral haemorrhage patients with and without spot sign on admission scan: a statistical analysis plan of a pre-specified sub-study of the TICH-2 trial

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    Objective We present the statistical analysis plan of a prespecified Tranexamic Acid for Hyperacute Primary Intracerebral Haemorrhage (TICH)-2 sub-study aiming to investigate, if tranexamic acid has a different effect in intracerebral haemorrhage patients with the spot sign on admission compared to spot sign negative patients. The TICH-2 trial recruited above 2000 participants with intracerebral haemorrhage arriving in hospital within 8 h after symptom onset. They were included irrespective of radiological signs of on-going haematoma expansion. Participants were randomised to tranexamic acid versus matching placebo. In this subgroup analysis, we will include all participants in TICH-2 with a computed tomography angiography on admission allowing adjudication of the participants’ spot sign status. Results Primary outcome will be the ability of tranexamic acid to limit absolute haematoma volume on computed tomography at 24 h (± 12 h) after randomisation among spot sign positive and spot sign negative participants, respectively. Within all outcome measures, the effect of tranexamic acid in spot sign positive/negative participants will be compared using tests of interaction. This sub-study will investigate the important clinical hypothesis that spot sign positive patients might benefit more from administration of tranexamic acid compared to spot sign negative patients
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