scholarly journals Morphological Alternations of Intraepithelial and Stromal Telocytes in Response to Salinity Challenges

2017 ◽  
Author(s):  
Soha Mohamed Abdel-latief Soliman ◽  
Walaa Fathy Ali Emeish
Keyword(s):  
Salinity Stress ◽  
Direct Contact ◽  
Experimental Studies ◽  
Chloride Cells ◽  
Target Cells ◽  
Secretory Vesicles ◽  
Skeletal Myoblast ◽  
Pavement Cells ◽  
Summary Statement ◽  
Rodlet Cells

Summary statementThe article represent an experimental study in which we investigated the effect of the ssalinty on the communicating cells (telocytes) and their target cells including chloride, stem, Rodlet cells, myoblastsAbstractTelocyte is a communicating cell established relations to various types of cells. Few experimental studies are performed on telocytes. The current study investigated responce of telocytes to salinity stress in relations to osmoregualtory, immune and stem cells. We exposed Common carp to salinity level 0.2, 6, 10, 14 ppt. Gill samples were fixed and processed for microscopic and TEM. Two types of telocytes were identified: intraepithelial and stromal telocytes. Intraepithelial telocytes comprised the cellular lining of the lymph spaces where they shed the secretory vesicles. Stromal telocytes shed their secretory vesicles in the secondary circulatory vessels. Telocyte enlarged and exhibited high secretory activities. They exert their effect either by direct contact or by paracrine mode. In sanity treated samples, chloride cells enlarged and the mitochondria became cigar-shaped. pavement cells enlarged and micro-ridges elongated. Stromal telocytes established contact with stem cell and skeletal myoblast. Macrophages and Rodlet cells increased in number. In conclusion, intraepithelial and stromal responded to salinity stress by activation of cellular signaling. They play a major role in osmoregulation, immunity, and regeneration.

scholarly journals EXPERIMENTAL STUDIES ON HETEROPLASTIC BONE FORMATION

1920 ◽  
Vol 32 (6) ◽  
pp. 745-766 ◽  
Author(s):  
Goichi Asami ◽  
William Dock
Keyword(s):  
Connective Tissue ◽  
Bone Formation ◽  
Direct Contact ◽  
Endochondral Ossification ◽  
Experimental Studies ◽  
Rabbit Kidney ◽  
Transitional Epithelium ◽  
Ear Cartilage ◽  
Calcium Deposits ◽  
New Formation

1. Bone formation in the rabbit kidney with ligated vessels takes place (a) through the activity of young fibroblasts which accumulate to form a membrane-like structure; (b) subsequently by direct ossification of hyaline connective tissue in continuity with preformed bone; and (c) through erosion of lime placques by granulating tissue and laying down of lamellar bone by cells derived from fibroblasts. 2. Bone formation in the rabbit kidney begins not in direct contact with calcium deposits, but in the loose vascular connective tissue close under the transitional epithelium of the calices. 3. With autotransplanted ear cartilage of the rabbit there is an active new formation of cartilage in the connective tissue which surrounds the transplants, and the bone is formed by the fibroblasts from the perichondrium which erode and invade the calcified areas in this new cartilage. 4. The process of bone formation in the kidney is similar to that found in normal membranous ossification, while with the transplanted ear cartilage the process is identical with endochondral ossification.

Transport properties of cultured branchial epithelia from freshwater rainbow trout: a novel preparation with mitochondria-rich cells

2000 ◽  
Vol 203 (10) ◽  
pp. 1523-1537 ◽  
Author(s):  
M. Fletcher ◽  
S.P. Kelly ◽  
P. Part ◽  
M.J. O'Donnell ◽  
C.M. Wood
Keyword(s):  
Rainbow Trout ◽  
Flux Ratio ◽  
Culture Conditions ◽  
Chloride Cells ◽  
Pavement Cells ◽  
Ratio Criterion ◽  
Peg 4000 ◽  
Tight Epithelia ◽  
Gill Filaments

A new double-seeded insert (DSI) technique is described for culture of branchial epithelial preparations from freshwater rainbow trout on filter supports. DSI epithelia contain both pavement cells and mitochondria-rich (MR) cells (15.7+/−2.5 % of total cell numbers). MR cells occur singly or in clusters, are voluminous, open apically to the ‘external environment’ and exhibit ultrastructural characteristics similar to those found in the ‘chloride cells’ of freshwater fish gills. After 6–9 days in culture with Leibovitz's L-15 medium on both surfaces (symmetrical conditions), transepithelial resistance (TER) stabilized at values as high as 34 k capomega cm(2), indicative of electrically ‘tight’ epithelia. The density of MR cells, the surface area of their clusters and transepithelial potential (TEP; up to +8 mV basolateral positive, mean +1.9+/−0.2 mV) were all positively correlated with TER. In contrast, preparations cultured using an earlier single-seeded insert (SSI) technique contained only pavement cells and exhibited a negligible TEP under symmetrical conditions. Na(+)/K(+)-ATPase activities of DSI preparations were comparable with those in gill filaments, but did not differ from those of SSI epithelia. Replacement of the apical medium with fresh water to mimic the in vivo situation (asymmetrical conditions) induced a negative TEP (−6 to −15 mV) and increased permeability to the paracellular marker PEG-4000. Under symmetrical conditions, unidirectional Na(+) and Cl(−) fluxes were in balance, and there was no active transport by the Ussing flux ratio criterion. Under asymmetrical conditions, there were large effluxes, small influxes and evidence for active Cl(−) uptake and Na(+) extrusion. Unidirectional Ca(2+) fluxes were only 0.5-1.0 % of Na(+) and Cl(−) fluxes; active net Ca(2+) uptake occurred under symmetrical conditions and active net extrusion under asymmetrical conditions. Thus, DSI epithelia exhibit some of the features of the intact gill, but improvements in culture conditions are needed before the MR cells will function as true freshwater ‘chloride cells’.

Characterization of branchial transepithelial calcium fluxes in freshwater trout, Salmo gairdneri

1988 ◽  
Vol 254 (3) ◽  
pp. R491-R498 ◽  
Author(s):  
S. F. Perry ◽  
G. Flik
Keyword(s):  
Active Transport ◽  
Calcium Uptake ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Apical Surface ◽  
Electrochemical Gradient ◽  
Plasma Membrane Vesicles ◽  
Pavement Cells ◽  
Calcium Fluxes

Experiments were performed to determine whether gill transepithelial calcium fluxes in the freshwater trout (Salmo gairdneri) are passive or require active transport and to characterize the mechanisms involved. A comparison of the in vivo unidirectional flux ratios with the flux ratios calculated according to the transepithelial electrochemical gradients revealed that calcium uptake from the water requires active transport of Ca2+. The inhibition of calcium uptake by external lanthanum, the specific deposition of lanthanum on the apical surface of chloride cells, and the favorable electrochemical gradient for calcium across the apical membrane suggest that the initial step in branchial calcium uptake is the passive entry of calcium into the cytosol of chloride cells through apical channels that are permeable to calcium. The study of gill basolateral plasma membrane vesicles demonstrated the existence of a high-affinity calmodulin-dependent calcium-transporting system [half-maximal Ca2+ concentration (K0.5) = 160 nM, Vmax = 1.86 nmol.min-1.mg protein-1]. This system actively transports calcium from the cytosol of chloride cells into the plasma against a sizeable electrochemical gradient, thereby completing the transepithelial uptake of calcium. Calcium efflux occurs passively through paracellular pathways between chloride cells and adjacent pavement cells or between neighboring pavement cells.

Validation of Finite Element Lower Extremity Model Using Drop Tower Testing

2013 ◽  
Author(s):  
Robbin Bertucci ◽  
R. Prabhu ◽  
M. F. Horstemeyer ◽  
James Sheng ◽  
Jun Liao ◽  
...  
Keyword(s):  
Finite Element ◽  
Shock Waves ◽  
Lower Extremity ◽  
Cause Of Death ◽  
Direct Contact ◽  
Computational Analysis ◽  
Experimental Studies ◽  
Lower Extremities ◽  
Drop Tower ◽  
Made In

Explosions are the leading cause of death on the battlefield [1]. These explosives, such as bombs and mines, generate shock waves which stimulate large accelerations and deformations. The resulting loads pose serious threats to military and civilians if not sufficiently evaluated and protected. The use of anti-vehicle landmines has become extremely common. Due to lower extremities being in direct contact with the floor of vehicles, the lower extremities are commonly injured during explosions [2]. These injuries can be seriously fatal. Although experimental studies have been performed to advance these understandings [2], limited progress has been made in computational analysis of shock waves on the lower extremity.

scholarly journals Human Monocytes and Neutrophils Store Transforming Growth Factor-α in a Subpopulation of Cytoplasmic Granules

Blood ◽  
1997 ◽  
Vol 90 (3) ◽  
pp. 1255-1266 ◽  
Author(s):  
Jero Calafat ◽  
Hans Janssen ◽  
Mona Stå hle-Bäckdahl ◽  
Astrid E.M. Zuurbier ◽  
Edward F. Knol ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Large Population ◽  
Target Cells ◽  
Secretory Vesicles ◽  
Inflammatory Reactions ◽  
Effector Cells ◽  
Cytoplasmic Granules ◽  
Transforming Growth Factor Α ◽  
Factor Α

Abstract Transforming growth factor-α (TGF-α) exerts several effects on target cells, such as neovascularization promotion and mitogenic signalling. Using immunoelectron microscopy, we show that monocytes and neutrophils, store TGF-α in cytoplasmic granules. In monocytes, TGF-α did not colocalize with components of peroxidase-positive granules or with albumin of secretory vesicles. Furthermore, no colocalization of TGF-α with components of azurophilic or specific granules or secretory vesicles was observed in neutrophils. Activated monocytes and tissue-macrophages contained much less TGF-α–positive granules, suggesting TGF-α release. Western blot analysis showed a protein of 10 kD in lysates of monocytes. TGF-α mRNA was detected in monocytoid cells from the bone marrow by in situ hybridization. This study shows for the first time that monocytes and neutrophils contain TGF-α in all stages of maturation and that TGF-α in monocytes is stored in a large population of peroxidase-negative granules suggesting a function for these granules. Monocytes and neutrophils are important effector cells in inflammatory reactions. The present finding that these cells contain TGF-α might explain complications such as fibrosis and neoplastic transformation, caused by chronic inflammation.

scholarly journals Fish telocytes and their relation to rodlet cells in ruby-red-fin shark (rainbow shark) Epalzeorhynchos frenatum (Teleostei: Cyprinidae)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hanan H. Abd-Elhafeez ◽  
Walied Abdo ◽  
Basma Mohamed Kamal ◽  
Soha A. Soliman
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Direct Contact ◽  
Cell Function ◽  
Cell Contact ◽  
Migration Ability ◽  
Thin Sections ◽  
3D Network ◽  
And Migration ◽  
Rodlet Cells

Abstract Telocytes comprise the major constituents of the supportive interstitial framework within the various organs. They form a 3D network between different types of stromal and non-stromal cells, which makes them distinctively vital. We have previously explored the origin of the peculiar rodlet cells, especially on their differential stages in aquatic species. The current study aimed at highlighting the relation of telocytes with different rodlet stages. Samples of fish, olfactory organs, and gills were processed for semi thin sections, transmission electron microscopy, and immunohistochemistry. It was evident in the study that telocytes formed a 3D interstitial network, entrapping stem cells and differentiating rodlet cells, to establish direct contact with stem cells. Differentiated stem cells and rodlet progenitor cells, practically in the granular and transitional stages, also formed ultrastructure junctional modifications, by which nanostructures are formed to establish cell contact with telocytes. Telocytes in turn also connected with macrophage progenitor cells. Telocytes (TCs) expressed CD34, CD117, VEGF, and MMP-9. In conclusion, telocytes established direct contact with the stem and rodlet cells in various differential stages. Telocytes may vitally influence stem/progenitor cell differentiation, regulate rodlet cell function, and express MPP-9 that may regulate immune cells functions especially, including movement and migration ability.

Shortening of Branchial Tight Junction Acid-Exposed Rainbow Trout (Oncorhynchus mykiss)

1991 ◽  
Vol 48 (10) ◽  
pp. 2028-2033 ◽  
Author(s):  
J. Freda ◽  
D. A. Sanchez ◽  
H. L. Bergman
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Tight Junctions ◽  
Relative Magnitude ◽  
Chloride Cells ◽  
Pavement Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Plasma Electrolytes ◽  
Gill Structure ◽  
Electrolyte Loss

The objective of this study was to investigate possible sites for Na+ loss in fish exposed to low environmental pH. In rainbow trout (Oncorhynchus mykiss) exposed to pH 4.0 for 1 h, a net loss of Na+ was stimulated, and changes in gill structure occurred. In addition to epithelial lifting and necrosis in the gills of acid-exposed fish, tight junctions between pavement epithelial cells and chloride cells decreased in length by 25% whereas tight junctions between adjacent pavement cells did not significantly change. In a second experiment where fish were moved from pH 4.0 or 3.5 water to pH 6.5 water, we observed that Na+ loss declined immediately and approached control levels. The reversible nature of the stimulation of Na+ loss indicates that the site of Na+ loss in the fish gill can be reversibly opened and closed, which is consistent with the known properties of tight junctions. We hypothesize that the opening of tight junctions contributes to the loss of plasma electrolytes at low environmental pH. However, the relative magnitude of electrolyte loss through the tight junctions remains unknown.

The effect of highly alkaline water (pH 9.5) on the morphology and morphometry of chloride cells and pavement cells in the gills of the freshwater rainbow trout: relationship to ionic transport and ammonia excretion

2000 ◽  
Vol 78 (2) ◽  
pp. 307-319 ◽  
Author(s):  
Pierre Laurent ◽  
Michael P Wilkie ◽  
Claudine Chevalier ◽  
Chris M Wood
Keyword(s):  
Rainbow Trout ◽  
Surface Area ◽  
Ammonia Excretion ◽  
Chloride Cells ◽  
Apical Surface ◽  
Influx Rate ◽  
Pavement Cells ◽  
Alkaline Water ◽  
Partial Restoration ◽  
Water Ph

Exposure of rainbow trout (Oncorhynchus mykiss) to alkaline water (pH 9.5) impairs ammonia excretion (JAmm) and gill-mediated ion-exchange processes, as characterized by decreased Cl- (JC1in) and Na+ influx (JNain) across the gill. Scanning electron microscopy suggested that the depression of JC1in was concomitant with an early decrease in the population of the most active chloride cells (CCs), partly compensated for by an increasing number of immature CCs. However, within 72 h after the onset of exposure to alkaline water, there was a 2-fold increase in the fractional apical surface area of CCs that paralleled complete recovery of the maximal Cl- influx rate (JC1max). These results suggest that recovery of JC1max was associated with greater CC surface area, resulting in more transport sites on the gill epithelium. Morphometric analysis of the outermost layer of pavement cells on the lamellar epithelium showed a greater density of microvilli during exposure to alkaline water, which may have contributed to partial restoration of the number of Na+ transport sites (JNamax). Finally, the blood-to-water gill-diffusion distance decreased by 27% after 72 h at pH 9.5, and likely contributed to progressive restoration of ammonia excretion in alkaline water.

Development of a Lower Extremity Model for Finite Element Analysis at Blast Condition

2011 ◽  
Author(s):  
Robbin Bertucci ◽  
Jun Liao ◽  
Lakiesha Williams
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shock Waves ◽  
Lower Extremity ◽  
Direct Contact ◽  
Computational Analysis ◽  
Experimental Studies ◽  
Lower Extremities ◽  
Element Analysis ◽  
Made In

Explosions are the leading cause of death on the battlefield [1]. These explosives generate shock waves which stimulate large accelerations and deformations. The resulting loads pose serious threats to military and civilians. Since lower extremities are in direct contact with the ground, the lower extremities are commonly injured during explosions [2]. These injuries could be seriously fatal. Although experimental studies have been performed to advance these understandings [2], limited progress has been made in computational analysis of shock waves on the lower extremity.

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