Search results for " Microscopy"
showing 10 items of 1617 documents
La mesure directe des forces de liaison entre les hydrates appliquée à la prise de plâtre
1998
Le phenomene de prise est un phenomene general, observable sur tous les liants mineraux, ciments siliceux, alumineux... et le plâtre. S'il existe des lois gouvernant la prise, elles doivent s'appliquer a tous ces liants. Aussi, il peut etre justifie de prendre tel ou tel liant pour modele si cela peut simplifier la premiere approche. Ici, l'objectif est de mesurer les forces entre les grains de silicate de calcium hydrate (phase C-S-H) qui est l'hydrate le plus caracteristique des ciments courants. Ces grains sont extremement petits et il a ete choisi de mettre au point les methodes travaillant sur le plâtre qui s'hydrate sous forme de gypse en formant des cristaux de 10 a 100 fois plus gro…
Human pathology in NCL
2013
AbstractIn childhood the neuronal ceroid lipofuscinoses (NCL) are the most frequent lysosomal diseases and the most frequent neurodegenerative diseases but, in adulthood, they represent a small fraction among the neurodegenerative diseases. Their morphology is marked by: (i) loss of neurons, foremost in the cerebral and cerebellar cortices resulting in cerebral and cerebellar atrophy; (ii) an almost ubiquitous accumulation of lipopigments in nerve cells, but also in extracerebral tissues. Loss of cortical neurons is selective, indiscriminate depletion in early childhood forms occurring only at an advanced stage, whereas loss of neurons in subcortical grey-matter regions has not been quantit…
In vivo confocal laser endomicroscopy of the human liver: a novel method for assessing liver microarchitecture in real time
2008
Background and study aims Confocal endomicroscopy is a unique novel tool for in vivo histology in humans. Due to limitations imposed by the form of the equipment and by sterilization workflows, its use has been limited to the gastrointestinal tract so far. We have developed a rigid miniaturized probe for confocal endomicroscopy of the human liver during laparoscopy. Patients and methods To assess the feasibility and potential clinical value of this new system (diameter 6.3 mm), 25 patients with liver disease were examined during routine minilaparoscopy under conscious sedation. Results Subsurface serial images (from surface to 250 microm) were generated in real time after fluorescein inject…
Post-extraction mesio-distal gap reduction assessment by confocal laser scanning microscopy - a clinical 3-month follow-up study
2017
[EN] AimThe aim of this 3-month follow-up study is to quantify the reduction in the mesio-distal gap dimension (MDGD) that occurs after tooth extraction through image analysis of three-dimensional images obtained with the confocal laser scanning microscopy (CLSM) technique. Materials and MethodsFollowing tooth extraction, impressions of 79 patients 1month and 72 patients 3months after tooth extraction were obtained. Cast models were processed by CLSM, and MDGD changes between time points were measured. ResultsThe mean mesio-distal gap reduction 1month after tooth extraction was 343.4m and 3months after tooth extraction was 672.3m. The daily mean gap reduction rate during the first term (bet…
A custom image-based analysis tool for quantifying elastin and collagen micro-architecture in the wall of the human aorta from multi-photon microscopy
2014
The aorta possesses a micro-architecture that imparts and supports a high degree of compliance and mechanical strength. Alteration of the quantity and/or arrangement of the main load-bearing components of this micro-architecture - the elastin and collagen fibers - leads to mechanical, and hence functional, changes associated with aortic disease and aging. Therefore, in the future, the ability to rigorously characterize the wall fiber micro-architecture could provide insight into the complicated mechanisms of aortic wall remodeling in aging and disease. Elastin and collagen fibers can be observed using state-of-the-art multi-photon microscopy. Image-analysis algorithms have been effective at…
Marine sponge collagen: isolation, characterization and effects on the skin parameters surface-pH, moisture and sebum
2002
A previously described isolation procedure for collagen of the marine sponge Chondrosia reniformis Nardo was modified for scaling-up reasons yielding 30% of collagen (freeze-dried collagen in relation to freeze-dried sponge). Light microscope observations showed fibrous structures. Transmission electron microscopy studies proved the collagenous nature of this material: high magnifications showed the typical periodic banding-pattern of collagen fibres. However, the results of the amino acid analysis differed from most publications, presumably due to impurities that still were present. In agreement with earlier studies, sponge collagen was insoluble in dilute acid mediums and all solvents inv…
Effect of chronic unloading and rehabilitation on human Achilles tendon properties: a velocity-encoded phase-contrast MRI study
2008
The objective of this study was to measure and monitor changes in Achilles tendon mechanical properties and force production capability of triceps surae muscles after 4 wk of limb suspension and 6 wk of physical rehabilitation. Five healthy volunteers underwent unilateral lower limb suspension followed by weekly physiotherapy. A velocity-encoded, phase-contrast magnetic resonance imaging (VE-PC-MRI) technique was used to estimate the tendon strain as a function of force produced during the submaximal isometric contractions. After limb suspension, triceps surae muscle strength decreased to 53.2 ± 15.6% (mean ± SD) of the presuspension level ( P < 0.05). Young's modulus, estimated from the…
Identification of epithelial gaps in human small and large intestine by confocal endomicroscopy.
2007
Background & Aims: Confocal endomicroscopy is an emerging technology that poses the endoscopist with challenges for identifying epithelial structures in the human intestine. We have shown previously that the murine intestinal epithelium is punctuated by gaps caused by cell shedding. The goals of this study were to determine if confocal endomicroscopy could resolve the presence of human epithelial gaps and whether a proinflammatory cytokine could increase cell shedding. Methods: Intestinal mucosa was imaged after staining with acriflavine. Confocal endomicroscopy of 17 patients yielded 6277 images from the human terminal ileum and rectum. Results were validated by parallel studies of anesthe…
Immunohistological and immunoelectron microscopic identification of TNF alpha in normal human and murine epidermis.
1992
The presence, distribution and cellular localization of tumour necrosis factor-alpha (TNF alpha) were investigated in normal human and murine epidermis using immunohistological and immunoelectron microscopic methods with monoclonal and polyclonal antibodies. The immunostaining revealed an intercellular plasma membrane and cytoplasmic labelling of the epidermal keratinocytes, but no labelling of Langerhans cells, melanocytes and Merkel cells. Large amounts of TNF alpha were regularly found in the sebaceous glands. These findings demonstrate that epidermal keratinocytes and especially sebocytes produce and release TNF alpha and that this keratinocyte-derived cytokine may be important for the …
Soleus aponeurosis strain distribution following chronic unloading in humans: an in vivo MR phase-contrast study.
2006
The in vivo strain properties of human skeletal muscle-tendon complexes are poorly understood, particularly following chronic periods of reduced load bearing. We studied eight healthy volunteers who underwent 4 wk of unilateral lower limb suspension (ULLS) to induce chronic unloading. Before and after the ULLS, maximum isometric ankle plantar flexion torque was determined by using a magnetic resonance (MR)-compatible dynamometry. Volumes of the triceps surae muscles and strain distribution of the soleus aponeurosis and the Achilles tendon at a constant submaximal plantar flexion (20% pre-maximal voluntary contraction) were measured by using MRI and velocity-encoded, phase-contrast MRI techn…