scholarly journals Peri-prosthetic tissue cells show osteogenic capacity to differentiate into the osteoblastic lineage

2017 ◽  
Vol 35 (8) ◽  
pp. 1732-1742 ◽  
Author(s):  
Monique A.E. Schoeman ◽  
Angela E. Oostlander ◽  
Karien Ede Rooij ◽  
Edward R. Valstar ◽  
Rob G.H.H. Nelissen
Keyword(s):  
Osteoblastic Lineage ◽  
Tissue Cells

HVEM Analysis of Microfilament Patterns in The Margins of Tissue Cells

1980 ◽  
Vol 38 ◽  
pp. 808-811
Author(s):  
Carol Allen
Keyword(s):  
Cell Movement ◽  
Cell Spreading ◽  
Living Cells ◽  
Tissue Cell ◽  
Large Sample Size ◽  
Cell Periphery ◽  
Whole Cell ◽  
Critical Point Drying ◽  
Lamellar Region ◽  
Tissue Cells

When provided with a suitable solid substrate, tissue cells undergo a rapid conversion from the spherical form expressed in suspension culture to a characteristic flattened morphology. As a result of this conversion, called cell spreading, the cell nucleus and organelles come to occupy a central region of “deep cytoplasm” which slopes steeply into a peripheral “lamellar” region less than 1 pm thick at its outer edge and generally free of cell organelles. Cell spreading is accomplished by a continuous outward repositioning of the lamellar margins. Cell translocation on the substrate results when the activity of the lamellae on one side of the cell become dominant. When this occurs, the cell is “polarized” and moves in the direction of the “leading lamellae”. Careful analysis of tissue cell locomotion by time-lapse microphotography (1) has shown that the deformational movements of the leading lamellae occur in a repeating cycle of advance and retreat in the direction of cell movement and that the rate of such deformations are positively correlated with the speed of cell movement. In the present study, the physical basis for these movements of the cell margin has been examined by comparative light microscopy of living cells with whole-mount electron microscopy of fixed cells. Ultrastructural observations were made on tissue cells grown on Formvar-coated grids, fixed with glutaraldehyde, further processed by critical-point drying, and then photographed in the High Voltage Electron Microscope. This processing and imaging system maintains the 3-dimensional organization of the whole cell, the relationship of the cell to the substrate, and affords a large sample size which facilitates quantitative analysis. Comparative analysis of film records of living cells with the whole-cell micrographs revealed that specific patterns of microfilament organization consistently accompany recognizable stages of lamellar formation and movement. The margins of spreading cells and the leading lamellae of locomoting cells showed a similar pattern of MF repositionings (Figs. 1-4). These results will be discussed in terms of a working model for the mechanics of lamellar motility which includes the following major features: (a) lamellar protrusion results when an intracellular force is exerted at a locally weak area of the cell periphery; (b) the association of cortical MFs with one another determines the local resistance to this force; (c) where MF-to-MF association is weak, the cell periphery expands and some cortical MFs are dragged passively forward; (d) contact of the expanded area with the substrate then triggers the lateral association and reorientation of these cortical MFs into MF bundles parallel to the direction of the expansion; and (e) an active interaction between these MF bundles associated with the cortex of the expanded lamellae and the cortical MFs which remained in the sub-lamellar region then pulls the latter MFs forward toward the expanded area. Thus, the advance of the cell periphery on the substrate occurs in two stages: a passive phase in which some cortical MFs are dragged outward by the force acting to expand the cell periphery, and an active phase in which additional cortical MFs are pulled forward by interaction with the first set. Subsequent interactions between peripheral microfilament bundles and filaments in the deeper cytoplasm could then transmit the advance gained by lamellar expansion to the bulk of the cytoplasm.

Increased matrix gene expression by glucose in rat neural connective tissue cells in culture

Diabetes ◽  
1991 ◽  
Vol 40 (5) ◽  
pp. 605-611 ◽  
Author(s):  
P. Muona ◽  
J. Peltonen ◽  
S. Jaakkola ◽  
J. Uitto
Keyword(s):  
Gene Expression ◽  
Connective Tissue ◽  
Cells In Culture ◽  
Matrix Gene ◽  
Tissue Cells

Increased formation and decreased resorption of bone in mice with elevated vitamin D receptor in mature cells of the osteoblastic lineage

2000 ◽  
Vol 14 (13) ◽  
pp. 1908-1916 ◽  
Author(s):  
Edith M. Gardiner ◽  
Paul A. Baldock ◽  
Gethin P. Thomas ◽  
Natalie A. Sims ◽  
N. Kathryn Henderson ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Osteoblastic Lineage

Hierarchical Self-Assembly of Microgel-Modified Biomaterials Surfaces

2014 ◽  
Vol 1622 ◽  
pp. 1-6
Author(s):  
Yong Wu ◽  
Jing Liang ◽  
Qichen Wang ◽  
Matthew Libera
Keyword(s):  
Self Assembly ◽  
Scale Effects ◽  
Control Surface ◽  
Poly Ethylene Glycol ◽  
Hydrogel Particles ◽  
Network Properties ◽  
Tissue Cells ◽  
Poly Ethylene ◽  
Non Line Of Sight

ABSTRACTMicrogels are hydrogel particles with micron and sub-micron diameters. They have beendeveloped, studied, and exploited for a broad range of applications because of their uniquecombination of size, soft mechanical properties, and controllable network properties. We havebeen using microgels to modulate the properties of surfaces to differentially control theirinteractions with tissue cells and bacteria. The long-term goal is to create biomaterials thatpromote healing while simultaneously inhibiting infection. Because poly(ethylene glycol) [PEG]is used in a number of FDA-approved products and has well-known antifouling properties, wework primarily with PEG-based microgels. We render these anionic either by copolymerizationwith monomeric acids or by blending with polyacids. Both methods produce pH-dependentnegative charge. Surfaces, both planar 2-D surfaces as well as topographically complex 3-Dsurfaces, can be modified using a hierarchy of non-line-of-sight electrostatic depositionprocesses that create biomaterials surfaces whose cell adhesiveness is modulated by a submonolayerof microgels. Average inter-microgel spacings of 1-2 microns exploit naturaldifferences between staphylococcal bacteria and tissue cells, which open the opportunity todifferentially control surface interactions with them based on length-scale effects. Afterdeposition, the microgels can be loaded with a variety of small-molecule, cationic antimicrobials.The details of loading depend on the relative sizes of the antimicrobials and the microgelnetwork structure as well as on the amount and spatial distribution of electrostatic charge withinboth the microgel and on the antimicrobial. The exposed surface between microgels can befurther modified by the adsorption of adhesion-promoting proteins such as fibronectin viaelectrostatic interaction. This approach combines a rich interplay of microgel structure andchemistry as a key component in a simple and translatable approach to modulate the surfaceproperties of next-generation biomaterials.

scholarly journals CELL RESPIRATION STUDIES

1927 ◽  
Vol 46 (1) ◽  
pp. 43-51
Author(s):  
Blake C. Wilbur ◽  
Geneva A. Daland ◽  
John Cohen
Keyword(s):  
Oxygen Consumption ◽  
Whole Blood ◽  
Repeated Measurements ◽  
Closed Space ◽  
Cell Respiration ◽  
Chemical Substances ◽  
Normal Individuals ◽  
Tissue Cells

A description is given of a closed space respiration apparatus which can be used to determine the amount of gas used or liberated by living blood or tissue cells, or chemical substances. Continuous observations can be made and repeated measurements recorded without interrupting the vital processes or destroying the cells. Studies of the oxygen consumption by whole blood in normal individuals and in patients with leucocytosis and myelogenous leucemia, as well as by white cells suspended in plasma, will be reported in subsequent papers.

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