Browsing by Subject "Imaging"

Now showing 1 - 4 of 4
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    Open Access
    Assessment of murine brain tissue shrinkage caused by different histological fixatives using magnetic resonance and computed tomography imaging
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Wehrl, Hans F.; Bezrukov, Ilja; Wiehr, Stefan; Lehnhoff, Mareike; Fuchs, Kerstin; Mannheim, Julia G.; Quintanilla-Martine, Leticia; Kohlhofer, Ursula; Kneilling, Manfred; Pichler, Bernd J.; Sauter, Alexander W.
    Especially for neuroscience and the development of new biomarkers, a direct correlation between in vivo imaging and histology is essential. However, this comparison is hampered by deformation and shrinkage of tissue samples caused by fixation, dehydration and paraffin embedding. We used magnetic resonance (MR) imaging and computed tomography (CT) imaging to analyze the degree of shrinkage on murine brains for various fixatives. After in vivo imaging using 7 T MRI, animals were sacrificed and the brains were dissected and immediately placed in different fixatives, respectively: zinc-based fixative, neutral buffered formalin (NBF), paraformaldehyde (PFA), Bouin-Holland fixative and paraformaldehyde-lysine-periodate (PLP). The degree of shrinkage based on mouse brain volumes, radiodensity in Hounsfield units (HU), as well as non-linear deformations were obtained. The highest degree of shrinkage was observed for PLP (68.1%, P<0.001), followed by PFA (60.2%, P<0.001) and NBF (58.6%, P<0.001). The zinc-based fixative revealed a low shrinkage with only 33.5% (P<0.001). Compared to NBF, the zinc-based fixative shows a slightly higher degree of deformations, but is still more homogenous than PFA. Tissue shrinkage can be monitored non-invasively with CT and MR. Zinc-based fixative causes the smallest degree of brain shrinkage and only small deformations and is therefore recommended for in vivo ex vivo comparison studies.
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    Open Access
    Comparison of clinical outcomes of immediate versus delayed placement of dental implants: A systematic review and meta- analysis
    (Wiley, 2021) Dopico, Jose; Kalemaj, Zamira; Buti, Jacopo; Ruben Garcia-Sanchez; Mardas, Nikos; Pardo Zamora, Guillermo; Dermatología, Estomatología, Radiología y Medicina Física; Facultades de la UMU
    Objective: Two focused questions were addressed: Focused question (Q1) 1) Are there any differences between immediate and delayed placement in terms of (i) sur- vival rate, (ii) success rate, (iii) radiographic marginal bone levels, (iv) height/(v)thick- ness of buccal wall, (vi) peri-implant mucosal margin position, (vii) aesthetics outcomes and (viii) patient reported outcomes? Focused question 2 (Q2) What is the estimated effect size of immediate implant placement for all parameters included in Q1? Materials and methods: An electronic search (MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials and OpenGray) and hand search were conducted up to November 2019. Randomised controlled trials (RCT) with delayed implant place- ment as controls were eligible in the analysis for Q1. Immediate dental implant arms RCTs, controlled clinical trials (CCTs) and prospective case series of immediate implant placement were eligible in the analysis for Q2. Results: Six papers (RCTs) were included in the analysis for Q1 and 53 papers (22 RCTs, 11 CCTs and 20 case series) for Q2. Q1: Meta-analyses did not show any signifi- cant difference in implant survival, but it did for bone levels and PES scores at 1 year post-loading, favouring the immediate group. Q2: Meta-analyses showed that imme- diate implants had a high survival rate (97%) and presented high PES scores (range 10.36 to 11.25). Information regarding marginal bone loss and gingival/papillary re- cession varied among all included studies. Conclusion: Similar survival rate was found between immediate and delayed implants. Immediate implants presented threefold early complications and twofold delayed complications. Success criteria should be reported more consistently, and the inci- dence/type of complications associated with immediate implants should be further explored.
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    Growth pattern of experimental glioblastoma
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Ahlstedt, Jonatan; Förnvik, Karolina; Helms, Gunther; Salford, Leif G.; Ceberg, Crister; Skagerberg, Gunnar; Redebrandt, Henrietta Nittby
    Glioblastoma multiforme (GBM) is an aggressive primary brain malignancy with a very poor prognosis. Researchers employ animal models to develop potential therapies. It is important that these models have clinical relevance. This means that old models, propagated for decades in cultures, should be questioned. Parameters to be evaluated include whether animals are immune competent or not, the infiltrative growth pattern of the tumor, tumor volume resulting in symptoms and growth rate. We here describe the growth pattern of an experimental glioblastoma model in detail with GFP positive glioblastoma cells in fully immune competent animals and study tumor growth rate and tumor mass as a function of time from inoculation. We were able to correlate findings made with classical immunohistochemistry and MR findings. The tumor growth rate was fitted by a Gompertz function. The model predicted the time until onset of symptoms for 5000 inoculated cells to 18.7±0.4 days, and the tumor mass at days 10 and 14, which are commonly used as the start of treatment in therapeutic studies, were 5.97±0.62 mg and 29.1±3.0 mg, respectively. We want to raise the question regarding the clinical relevance of the outline of glioblastoma experiments, where treatment is often initiated at a very early stage. The approach presented here could potentially be modified to gain information also from other tumor models.
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    Single-cell spatial proteomics
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Liyanage, Senal; Guo, Jia; Biología Celular e Histología
    Recent advancements in single-cell spatial proteomics have revolutionized our ability to elucidate cellular signaling networks and their implications in health and disease. This review examines these cutting-edge technologies, focusing on mass spectrometry (MS) imaging and multiplexed immunofluorescence (mIF). Such approaches allow high-resolution protein profiling at the single-cell level, revealing intricate cellular heterogeneity, spatial organization, and protein functions within their native cellular contexts. MS imaging techniques offer unprecedented high-dimensional resolution and provide detailed insights into their subcellular protein localization and abundance. mIF enables rapid and high-throughput protein profiling, enhancing its accessibility for diverse research and clinical applications. This review assesses the current challenges associated with these methodologies and also discusses the potential solutions to overcome these obstacles. The integration of spatial proteomics with other systems biology approaches holds great promise for enhancing our understanding of complex biological systems. It could also lead to significant advancements in molecular diagnostics and personalized treatment strategies.