Search results for "Microscopy"

Mesopolysaccharides: The extracellular surface layer of visceral organs

2020

The mesothelium is a dynamic and specialized tissue layer that covers the somatic cavities (pleural, peritoneal, and pericardial) as well as the surface of the visceral organs such as the lung, heart, liver, bowel and tunica vaginalis testis. The potential therapeutic manipulation of visceral organs has been complicated by the carbohydrate surface layer—here, called the mesopolysaccharide (MPS)—that coats the outer layer of the mesothelium. The traditional understanding of MPS structure has relied upon fixation techniques known to degrade carbohydrates. The recent development of carbohydrate-preserving fixation for high resolution imaging techniques has provided an opportunity to re-examine…

Malignant Rhabdoid Tumor in the Gastric Wall of an Aged Orangutan (Pongo pygmaeus)

1994

A 34-year-old female orangutan ( Pongo pygmaeus) developed renal failure and became uremic. At necropsy, large gastric masses were present around the cardia and in the corpus. Abdominal metastases occurred in the liver, pancreas, and right ovary. Light microscopic examination of the tumor revealed polygonal cells with vesicular nuclei and prominent nucleoli. The growth pattern was predominantly solid. Focal areas contained excentric cytoplasmic intermediate filament inclusions, as identified by immunohistochemistry and electron microscopy. Immunohisiochemical procedures demonstrated mainly the vimentin type of intermediate filaments. Except for occasional cytokeratin, other intermediate fil…

A Novel Cervical Spinal Cord Window Preparation Allows for Two-Photon Imaging of T-Cell Interactions with the Cervical Spinal Cord Microvasculature d…

2017

T-cell migration across the blood-brain barrier (BBB) is a crucial step in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple scle rosis (MS). Two-photon intravital microscopy (2P-IVM) has been established as a powerful tool to study cell-cell interactions in inflammatory EAE lesions in living animals. In EAE, central nervous system inflammation is strongly pronounced in the spinal cord, an organ in which 2P-IVM imaging is technically very challenging and has been limited to the lumbar spinal cord. Here, we describe a novel spinal cord window preparation allowing to use 2P-IVM to image immune cell interactions with the cervical spinal cord micro…

A survey of clearing techniques for 3D imaging of tissues with special reference to connective tissue

2016

AbstractFor 3-dimensional (3D) imaging of a tissue, 3 methodological steps are essential and their successful application depends on specific characteristics of the type of tissue. The steps are 1° clearing of the opaque tissue to render it transparent for microscopy, 2° fluorescence labeling of the tissues and 3° 3D imaging. In the past decades, new methodologies were introduced for the clearing steps with their specific advantages and disadvantages. Most clearing techniques have been applied to the central nervous system and other organs that contain relatively low amounts of connective tissue including extracellular matrix. However, tissues that contain large amounts of extracellular mat…

Kupffer Cell and Monocyte-Derived Macrophage Identification by Immunofluorescence on Formalin-Fixed, Paraffin-Embedded (FFPE) Mouse Liver Sections

2020

Kupffer cells are the liver-resident macrophages and represent the first line of defense between the pathogens circulating from the intestines through the portal vein and systemic circulation. Recent works have highlighted the complex heterogeneity of macrophage functions and origins, thus raising awareness on the need for a better characterization of macrophage populations. The immunohistochemistry method here described, allows for a rapid distinction between Kupffer cells and monocyte-derived macrophages present on formalin-fixed, paraffin-embedded mouse liver samples. This protocol has been optimized for its reproducibility, reliability, and simplicity.

2021

Angiotensin II (Ang II) has been implicated in the pathophysiology of various age-dependent ocular diseases. The purpose of this study was to test the hypothesis that Ang II induces endothelial dysfunction in mouse ophthalmic arteries and to identify the underlying mechanisms. Ophthalmic arteries were exposed to Ang II in vivo and in vitro to determine vascular function by video microscopy. Moreover, the formation of reactive oxygen species (ROS) was quantified and the expression of prooxidant redox genes and proteins was determined. The endothelium-dependent artery responses were blunted after both in vivo and in vitro exposure to Ang II. The Ang II type 1 receptor (AT1R) blocker, candesar…

View images with unprecedented resolution in integral microscopy

2018

Integral microscopy is a novel technique that allows the simultaneous capture of multiple perspective images of microscopic samples. This feature is achieved at the cost of a significant reduction of the spatial resolution. In fact, it is assumed that in the best cases the resolution is reduced by a factor that is not smaller than ten, what poses a hard drawback to the utility of the technique. However, to the best of our knowledge, this resolution limitation has never been researched rigorously. For this reason, the aim of this paper is to explore the real limitations in resolution of integral microscopy and to obtain optically, without the need of any image-processing algorithm, perspecti…

Comparative measurement of collagen bundle orientation by Fourier analysis and semiquantitative evaluation: reliability and agreement in Masson's tri…

2017

Summary Measurement of collagen bundle orientation in histopathological samples is a widely used and useful technique in many research and clinical scenarios. Fourier analysis is the preferred method for performing this measurement, but the most appropriate staining and microscopy technique remains unclear. Some authors advocate the use of Haematoxylin-Eosin (H&E) and confocal microscopy, but there are no studies comparing this technique with other classical collagen stainings. In our study, 46 human skin samples were collected, processed for histological analysis and stained with Masson's trichrome, Picrosirius red and H&E. Five microphotographs of the reticular dermis were taken with a 20…

The ascidian Styela plicata hemocytes as a potential biomarker of marine pollution: In vitro effects of seawater and organic mercury.

2017

Toxic metals, such as mercury, contribute substantially to anthropogenic pollution in many estuarine environments. Animals living in those environments, particularly invertebrate filter feeders like tunicates, can be used as bioindicators. In an attempt to identify cellular markers for revealing pollution, this study examined in vitro the effects of different concentrations of methyl mercury on Styela plicata hemocytes. The harvested hemocytes from S. plicata that were exposed to the metal had a significant mortality, cellular count and morphometric alterations. These findings provided evidence of MeHg immunotoxic effects on S. plicata, resulting in hemocyte death and morphological changes …

Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations

2017

Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-p…