Chemical degeneration of intestinal nerves

1990 ◽  
Vol 258 (6) ◽  
pp. G848-G855 ◽  
Author(s):  
C. T. Frantzides ◽  
J. C. Garancis ◽  
B. T. Doumas ◽  
R. E. Condon
Keyword(s):  
Substance P ◽  
Cobalt Chloride ◽  
Ganglion Cells ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Mucosal Cells ◽  
Cobalt Solution ◽  
Small Intestinal ◽  
Immunohistochemical Studies

In 15 dogs, cobalt chloride solutions were infused close intra-arterially to perfuse a short segment of the jejunum. In an additional four dogs, the jejunum was perfused with the aqueous vehicle (perfusion control). All animals were killed after 1 mo and tissue samples from cobalt-treated and from nonperfused intestine (tissue comparison control) were obtained for electron microscopic and immunohistochemical studies. Segments infused with 0.25 g/dl cobalt solution showed minimal changes; the most striking feature was an increase of vasoactive intestinal polypeptide (VIP)- and substance P-containing neurosecretory granules. Cobalt chloride at higher concentrations (0.75-1.5 g/dl) induced degeneration of ganglion cells and axons in both the myenteric and submucosal plexi. In contrast, the smooth muscle and the mucosal cells of the cobalt-perfused intestine showed no histological abnormalities. Immunohistochemical staining of tissues treated with 0.75-1.5 g/dl cobalt solutions revealed absence of substance P, Met-enkephalin, and VIP immunoreactivity in all section studied; control segments showed the presence of all three peptides. Cobalt chloride in concentrations of 0.75-1.5 g/dl causes degeneration of intestinal intramural nerves and provides an experimental model suitable for studying the role of these nerves in small intestinal function.

Modeling the Inflation Response of C57BL/6 Mouse Sclera

2011 ◽  
Author(s):  
Kristin M. Myers ◽  
Thao D. Nguyen
Keyword(s):  
Material Properties ◽  
Soft Tissues ◽  
Ganglion Cells ◽  
The United States ◽  
Small Rodent ◽  
Tissue Samples ◽  
Tissue Microstructure ◽  
Material Parameters ◽  
Meaningful Material

Small rodent models have become increasingly useful to investigate how the mechanical properties of soft tissues may influence disease development. These animal models allow access to aged, diseased, or genetically-altered tissue samples, and through comparisons with wild-type or normal tissue it can be explored how each of these variables influence tissue function. The challenges to deriving meaningful material parameters for these small tissue samples include designing physiologically-relevant mechanical testing protocols and interpreting the experimental load-displacement data in an appropriate constitutive framework to quantify material parameters. This study was motivated by determining the possible role of scleral material properties in the development of glaucomatous damage to the retinal ganglion cells (RGC). Glaucoma is one of the leading causes of blindness in the United States and in the world with an estimate of 60 million people affected by this year [1]. Through exploring mouse models, the overall goal of our work is to determine the role of scleral material properties and scleral tissue microstructure in the pathogenesis of glaucoma.

Role of Reactive Oxygen Species and NFKB p65 in the Lupus Kidney

2000 ◽  
Vol 6 (S2) ◽  
pp. 486-487
Author(s):  
M. Nishikawa ◽  
R. Igarashi ◽  
T. Nakazawa ◽  
E. Aikawa
Keyword(s):  
Reactive Oxygen Species ◽  
Lupus Nephritis ◽  
Reactive Oxygen ◽  
Renal Tissue ◽  
Oxygen Species ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Cacodylate Buffer ◽  
Cytochemical Reaction

Reactive oxygen species (ROS) play an important role in lupus nephritis. It has been known that nuclear factor kB(NFkB) is activated by ROS, and binds to KB element in nucleus. Afterwards, inflammatory cytokines are translated and produced in lymphocytes, macrophages and glomerular cells in the kidney. In this study, we investigated the role of ROS and NFkB p65 in the pathogenesis of lupus nephritis (MRL lpr/lpr mice) by the histochemical and immuno-electron microscopic methods.A modified Brigg’s method was used to determine the generation of H2O2 in the renal tissue of lupus mice. Tissue samples were incubate in 0.1 MTris maleate buffer (pH 7.4) with 7% sucrose, 1mM CeCl3 and 10 mM aminotriazole at 37 °C for 30 min. After completion of the cytochemical reaction, tissues were fixed in 2% w/v glutaraldehyde in 0.1 M cacodylate buffer (pH 7.4) at 4 °C for 60 min.

Stannous fluoride treatment of acid-etched caries-like lesions of enamel: A scanning electron microscopic study

1984 ◽  
Vol 42 ◽  
pp. 720-721
Author(s):  
M. John Hicks ◽  
Leon M. Silverstone ◽  
David G. Gantt ◽  
Catherine M. Flaitz
Keyword(s):  
Acid Etching ◽  
Surface Zone ◽  
Electron Microscopic ◽  
Fluoride Treatment ◽  
Stannous Fluoride ◽  
Scanning Electron Microscopic Study ◽  
Demineralized Enamel ◽  
Intact Surface ◽  
Topical Fluoride

Although fluoride levels become elevated in sound enamel following a topical fluoride treatment, the caries-preventive effect of fluoride is thought to be due primarily to the role of fluoride in remineralization of clinically undetectable enamel lesions and hypomineralized enamel. During lesion formation, redistribution of fluoride from the enamel surface to the subsurface demineralized enamel occurs. This results in a surface zone with a relatively low fluoride content. In order to maintain an intact surface zone over a carious lesion, it may be necessary to replenish the fluoride levels with an exogenous fluoride source. By acid-etching the lesion surface, a more reactive surface is made available for fluoride interaction. In addition, porosities and etching patterns may be created, allowing for bonding of a caries-resistant resin material to the lesion surface. The purpose of this study was to determine the integrity of the caries-like lesion surface following acid-etching and subsequent stannous fluoride treatment (SnF2).

An Electron Microscopic Study of the Acute Effects of Hypothalamic Releasing Factors on the Anterior Pituitary Gland

1968 ◽  
Vol 26 ◽  
pp. 232-233
Author(s):  
P.W. Coates ◽  
E.A. Ashby ◽  
L. Krulich ◽  
A. Dhariwal ◽  
S. McCann
Keyword(s):  
Anterior Pituitary ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Thin Sections ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Releasing Factors

The morphologic effects on somatotrophs of crude sheep hypothalamic extract prepared from stalk-median eminence were studied by electron microscopy in conjunction with concurrently run bioassays performed on the same tissue samples taken from young adult male Sherman rats.Groups were divided into uninjected controls and injected experimentals sacrificed at 5', 15', and 30' after injection. Half of each anterior pituitary was prepared for electron microscopic investigation, the other half for bioassay. Fixation using collidine buffered osmium tetroxide was followed by dehydration and embedment in Maraglas. Uranyl acetate and lead citrate were used as stains. Thin sections were examined in a Philips EM 200.Somatotrophs from uninjected controls appeared as described in the literature (Fig. 1). In addition to other components, these cells contained moderate numbers of spherical, electron-dense, membrane-bound granules approximately 350 millicrons in diameter.

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

High-voltage electron microscopic studies of inflammatory cell attachment during blood-brain barrier inflammation

1990 ◽  
Vol 48 (3) ◽  
pp. 276-277
Author(s):  
A.S. Lossinsky ◽  
M.J. Song
Keyword(s):  
High Voltage ◽  
Inflammatory Cell ◽  
Cell Attachment ◽  
Electron Microscopic ◽  
Vascular Perfusion ◽  
Tissue Samples ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron

Previous studies have suggested the usefulness of high-voltage electron microscopy (HVEM) for investigating blood-bram barrier (BBB) injury and the mechanism of inflammatory-cell (IC) attachment. These studies indicated that, in evaluating standard conventional thin sections, one might miss cellular attachment sites of ICs in their process of attaching to the luminal endothelial cell (EC) surface of cerebral blood vessels. Our current studies in animals subjected to autoimmune disease suggest that HVEM may be useful in localizing precise receptor sites involved in early IC attachment.Experimental autoimmune encephalomyelitis (EAE) was induced in mice and rats according to standard procedures. Tissue samples from cerebellum, thalamus or spinal cords were embedded in plastic following vascular perfusion with buffered aldehyde. Thick (0.5-0.7 μm) sections were cut on glass knives and collected on Formvar-coated slot grids stained with uranylacetate and lead citrate and examined with the AEI EM7 1.2 MV HVEM in Albany, NY at 1000 kV.

Role of stat6 in hypercontractility of murine small intestinal smooth muscle induced by nematode infection

2001 ◽  
Vol 120 (5) ◽  
pp. A534-A534
Author(s):  
A ZHAO ◽  
D MULLOY ◽  
J URBANJR ◽  
W GAUSE ◽  
T SHEADONOHUE
Keyword(s):  
Smooth Muscle ◽  
Nematode Infection ◽  
Intestinal Smooth Muscle ◽  
Small Intestinal

scholarly journals Possible Role of IRS-4 in the Origin of Multifocal Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2560
Author(s):  
Luis G. Guijarro ◽  
Patricia Sanmartin-Salinas ◽  
Eva Pérez-Cuevas ◽  
M. Val Toledo-Lobo ◽  
Jorge Monserrat ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Cancer ◽  
Hepg2 Cells ◽  
Cellular Polarity ◽  
Ki 67 ◽  
Tissue Samples ◽  
Vitro Analysis ◽  
Tumoral Cells

New evidence suggests that insulin receptor substrate 4 (IRS-4) may play an important role in the promotion of tumoral growth. In this investigation, we have evaluated the role of IRS-4 in a pilot study performed on patients with liver cancer. We used immunohistochemistry to examine IRS-4 expression in biopsies of tumoral tissue from a cohort of 31 patient suffering of hepatocellular carcinoma (HCC). We simultaneously analyzed the expression of the cancer biomarkers PCNA, Ki-67, and pH3 in the same tissue samples. The in vitro analysis was conducted by studying the behavior of HepG2 cells following IRS-4 overexpression/silencing. IRS-4 was expressed mainly in the nuclei of tumoral cells from HCC patients. In contrast, in healthy cells involved in portal triads, canaliculi, and parenchymal tissue, IRS-4 was observed in the cytosol and the membrane. Nuclear IRS-4 in the tumoral region was found in 69.9 ± 3.2%, whereas in the surrounding healthy hepatocytes, nuclear IRS-4 was rarely observed. The percentage of tumoral cells that exhibited nuclear PCNA and Ki-67 were 52.1 ± 7%, 6.1 ± 1.1% and 1.3 ± 0.2%, respectively. Furthermore, we observed a significant positive linear correlation between nuclear IRS-4 and PCNA (r = 0.989; p < 0.001). However, when we correlated the nuclear expression of IRS-4 and Ki-67, we observed a significant positive curvilinear correlation (r = 0.758; p < 0.010). This allowed us to define two populations, (IRS-4 + Ki-67 ≤ 69%) and (IRS-4 + Ki-67 > 70%). The population with lower levels of IRS-4 and Ki-67 had a higher risk of suffering from multifocal liver cancer (OR = 16.66; CI = 1.68–164.8 (95%); p < 0.05). Immunoblot analyses showed that IRS-4 in normal human liver biopsies was lower than in HepG2, Huh7, and Chang cells. Treatment of HepG2 with IGF-1 and EGF induced IRS-4 translocation to the nucleus. Regulation of IRS-4 levels via HepG2 transfection experiments revealed the protein’s role in proliferation, cell migration, and cell-collagen adhesion. Nuclear IRS-4 is increased in the tumoral region of HCC. IRS-4 and Ki-67 levels are significantly correlated with the presence of multifocal HCC. Moreover, upregulation of IRS-4 in HepG2 cells induced proliferation by a β-catenin/Rb/cyclin D mechanism, whereas downregulation of IRS-4 caused a loss in cellular polarity and in its adherence to collagen as well as a gain in migratory and invasive capacities, probably via an integrin α2 and focal adhesion cascade (FAK) mechanism.

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