ultrastructural process of intestinal wound healing

We have developed an intestinal wound model that includes surgical construction of an ileo-cecal patch to study the complex process of intestinal wound healing. This allows approximation of ileal mucosa to the cecal serosa and facilitates regeneration of ileal mucosa onto the serosal surface of the cecum. The regeneration of ileal mucosa can then be evaluated at different times. The wound model also allows us to determine the rate of intestinal regeneration for a known size of intestinal wound and can be compared in different situations (e.g. with and without EGF and Peyer’s patches).At the light microscopic level it appeared that epithelial cells involved in regeneration of ileal mucosa originated from the enlarged crypts adjacent to the intestinal wound and migrated in an orderly fashion onto the serosal surface of the cecum. The migrating epithelial cells later formed crypts and villi by the process of invagination and evagination respectively. There were also signs of proliferation of smooth muscles underneath the migratory epithelial cells.

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Hypoxia-induced changes in Ca2+ mobilization and protein phosphorylation implicated in impaired wound healing

AJP Cell Physiology ◽

10.1152/ajpcell.00110.2013 ◽

2014 ◽

Vol 306 (10) ◽

pp. C972-C985 ◽

Cited By ~ 16

Author(s):

Albert Lee ◽

Kelsey Derricks ◽

Martin Minns ◽

Sophina Ji ◽

Cheryl Chi ◽

...

Keyword(s):

Wound Healing ◽

Epithelial Cells ◽

Wound Repair ◽

Purinergic Receptor ◽

Sorting Algorithm ◽

Impaired Wound Healing ◽

Corneal Epithelial ◽

Extracellular Milieu ◽

Wound Model ◽

Induced Changes

The process of wound healing must be tightly regulated to achieve successful restoration of injured tissue. Previously, we demonstrated that when corneal epithelium is injured, nucleotides and neuronal factors are released to the extracellular milieu, generating a Ca2+ wave from the origin of the wound to neighboring cells. In the present study we sought to determine how the communication between epithelial cells in the presence or absence of neuronal wound media is affected by hypoxia. A signal-sorting algorithm was developed to determine the dynamics of Ca2+ signaling between neuronal and epithelial cells. The cross talk between activated corneal epithelial cells in response to neuronal wound media demonstrated that injury-induced Ca2+ dynamic patterns were altered in response to decreased O2 levels. These alterations were associated with an overall decrease in ATP and changes in purinergic receptor-mediated Ca2+ mobilization and localization of N-methyl-d-aspartate receptors. In addition, we used the cornea in an organ culture wound model to examine how hypoxia impedes reepithelialization after injury. There was a change in the recruitment of paxillin to the cell membrane and deposition of fibronectin along the basal lamina, both factors in cell migration. Our results provide evidence that complex Ca2+-mediated signaling occurs between sensory neurons and epithelial cells after injury and is critical to wound healing. Information revealed by these studies will contribute to an enhanced understanding of wound repair under compromised conditions and provide insight into ways to effectively stimulate proper epithelial repair.

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Localization of ouabain-binding sites in frog gastric mucosa

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1982.243.4.g297 ◽

1982 ◽

Vol 243 (4) ◽

pp. G297-G303

Author(s):

H. F. Helander ◽

R. P. Durbin

Keyword(s):

Gastric Mucosa ◽

Epithelial Cells ◽

Electrical Activity ◽

Acid Secretion ◽

Binding Sites ◽

Microscopic Level ◽

Light Microscopic Level ◽

Ouabain Binding ◽

Oxyntic Cell ◽

Silver Grains

Autoradiography at the light microscopic level was used to localize sites of [3H]ouabain binding in isolated stimulated frog gastric mucosa. Silver grains denoting binding were located near basal and lateral surfaces in both oxyntic and surface epithelial cells. Binding to oxyntic cells occurred well before inhibition of acid secretion, consistent with the view that inhibition by this drug is indirect, and subsequent to inactivation of oxyntic cell Na+-K+-ATPase and the resulting depression of cellular K+. The presence of Na+-K+-ATPase in surface cells, as shown by binding of labeled ouabain, suggests a role for that transport enzyme in electrical activity and secretion of alkali by these cells.

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Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053747 ◽

1982 ◽

Vol 40 ◽

pp. 216-217

Author(s):

D. J. McComb ◽

J. Beri ◽

F. Zak ◽

K. Kovacs

Keyword(s):

Microscopic Study ◽

Pituitary Adenomas ◽

Wistar Rats ◽

Microscopic Level ◽

Sprague Dawley ◽

Prolactin Cells ◽

Light Microscopic Level ◽

Ultrastructural Investigation ◽

Sprague Dawley Rats ◽

Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

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The Fine Structure of Irradiated Mouse Heart

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090907 ◽

1976 ◽

Vol 34 ◽

pp. 184-185

Author(s):

Vivian V. Yang ◽

S. Phyllis Stearner

Keyword(s):

Microscopic Level ◽

Ultrastructural Changes ◽

Mouse Heart ◽

Blood Vessel Wall ◽

Histopathological Changes ◽

Light Microscopic Level ◽

Γ Rays ◽

Fission Neutrons ◽

Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

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Liquid crystalline ordering of paired helical filaments in neurofibrillary tangles of Alzheimer's disease

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143365 ◽

1986 ◽

Vol 44 ◽

pp. 348-349

Author(s):

D.F. Clapin ◽

V.J.A. Montpetit

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurofibrillary Tangles ◽

Liquid Crystalline ◽

Amyloid Fibrils ◽

Geometric Analysis ◽

Paired Helical Filaments ◽

Microscopic Level ◽

Light Microscopic Level ◽

Regular Spacing

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.

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Ultrastorcture of Cerebellar Purkinje Cells in Rats Subjected To Partial Global Cerebral Ischemia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120060 ◽

1985 ◽

Vol 43 ◽

pp. 674-675

Author(s):

R.V.W. Dimlich ◽

M.H. Biros

Keyword(s):

Cerebral Ischemia ◽

Purkinje Cells ◽

Cell Types ◽

Microscopic Level ◽

Global Cerebral Ischemia ◽

Light Microscopic Level ◽

Cerebellar Damage ◽

Cerebellar Injury ◽

Cerebellar Purkinje Cells ◽

Cell Changes

In severe cerebral ischemia, Purkinje cells of the cerebellum are one of the cell types most vulnerable to anoxic damage. In the partial (forebrain) global ischemic (PGI) model of the rat, Paljärvi noted at the light microscopic level that cerebellar damage is inconsistant and when present, milder than in the telencephalon, diencephalon and rostral brain stem. Cerebellar injury was observed in 3 of 4 PGI rats following 5 minutes of reperfusion but in none of the rats after 90 min of reperfusion. To evaluate a time between these two extremes (5 and 90 min), the present investigation used the PGI model to study the effects of ischemia on the ultrastructure of cerebellar Purkinje cells in rats that were sacrificed after 30 min of reperfusion. This time also was chosen because lactic acid that is thought to contribute to ischemic cell changes in PGI is at a maximum after 30 min of reperfusion.

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An ultrastructural study on the shark liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016011x ◽

1990 ◽

Vol 48 (3) ◽

pp. 512-513

Author(s):

Masako Yamada ◽

Yutaka Tanuma

Keyword(s):

Portal Vein ◽

Kupffer Cells ◽

Ultrastructural Study ◽

Lipid Droplets ◽

Microscopic Level ◽

The Other ◽

Fish Stock ◽

Structural Studies ◽

Light Microscopic Level ◽

Perfusion Fixation

Although many fine structural studies on the vertebrate liver have been reported on mammals, avians, reptiles, amphibians, teleosts and cyclostomes, there are no studies on elasmobranchii liver except one by T. Ito etal. (1962) who studied it on light microscopic level. The purpose of the present study was to as certain the ultrastructural details and cytochemical characteristics of normal elasmobranchii liver and was to compare with the other higher vertebrate ones.Seventeen Scyliorhinus torazame, one kind of elasmobranchii, were obtained from the fish stock of the Ueno Zoo aquarium, Ueno, Tokyo. The sharks weighing about 300-600g were anesthetized with MS-222 (Sigma), and the livers were fixed by perfusion fixation via the portal vein according to the procedure of Y. Saito et al. (1980) for 10 min. Then the liver tissues were immersed in the same fixative for 2 hours and postfixed with 1% OsO4-solution in 0.1 Mc acodylate buffer for one hour. In order to make sure a phagocytic activity of Kupffer cells, latex particles (0.8 μm in diameter, 0.05mg/100 g b.w.) were injected through the portal vein for one min before fixation. For preservation of lipid droplets in the cytoplasm, a series of these procedure were performed under ice cold temperature until the end of dehydration.

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Uterine Wound Healing: A Complex Process Mediated by Proteins and Peptides

Current Protein and Peptide Science ◽

10.2174/1389203717666160322145939 ◽

2016 ◽

Vol 18 (2) ◽

pp. 125-128 ◽

Cited By ~ 11

Author(s):

Dario Lofrumento ◽

Maria Nardo ◽

Marianna Falco ◽

Andrea Lieto

Keyword(s):

Wound Healing ◽

Complex Process ◽

Proteins And Peptides

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Composite Ferroelectric Membranes Based on Vinylidene Fluoride-Tetrafluoroethylene Copolymer and Polyvinylpyrrolidone for Wound Healing

Membranes ◽

10.3390/membranes11010021 ◽

2020 ◽

Vol 11 (1) ◽

pp. 21

Author(s):

Tamara S. Tverdokhlebova ◽

Ludmila S. Antipina ◽

Valeriya L. Kudryavtseva ◽

Ksenia S. Stankevich ◽

Ilya M. Kolesnik ◽

...

Keyword(s):

Wound Healing ◽

Vinylidene Fluoride ◽

Ferroelectric Properties ◽

Composite Membranes ◽

Modern Medicine ◽

In Vivo Studies ◽

Cytotoxic Effects ◽

Complex Process ◽

Purulent Wounds

Wound healing is a complex process and an ongoing challenge for modern medicine. Herein, we present the results of study of structure and properties of ferroelectric composite polymer membranes for wound healing. Membranes were fabricated by electrospinning from a solution of vinylidene fluoride/tetrafluoroethylene copolymer (VDF–TeFE) and polyvinylpyrrolidone (PVP) in dimethylformamide (DMF). The effects of the PVP content on the viscosity and conductivity of the spinning solution, DMF concentration, chemical composition, crystal structure, and conformation of VDF–TeFE macromolecules in the fabricated materials were studied. It was found that as PVP amount increased, the viscosity and conductivity of the spinning solutions decreased, resulting in thinner fibers. Using FTIR and XRD methods, it was shown that if the PVP content was lower than 50 wt %, the VDF–TeFE copolymer adopted a flat zigzag conformation (TTT conformation) and crystalline phases with ferroelectric properties were formed. Gas chromatography results indicated that an increase in the PVP concentration led to a higher residual amount of DMF in the material, causing cytotoxic effects on 3T3L1 fibroblasts. In vivo studies demonstrated that compared to classical gauze dressings impregnated with a solution of an antibacterial agent, ferroelectric composite membranes with 15 wt % PVP provided better conditions for the healing of purulent wounds.

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