scholarly journals STIMULATION BY ENDOCYTOSIS OF THE SECRETION OF COLLAGENASE AND NEUTRAL PROTEINASE FROM RABBIT SYNOVIAL FIBROBLASTS

1974 ◽  
Vol 140 (6) ◽  
pp. 1482-1497 ◽  
Author(s):  
Zena Werb ◽  
John J. Reynolds
Keyword(s):  
Culture Medium ◽  
Monolayer Culture ◽  
Synovial Fibroblasts ◽  
Neutral Endopeptidase ◽  
Lysosomal Hydrolases ◽  
Latex Particles ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
And Storage ◽  
Vacuolar System

Rabbit synovial fibroblasts in monolayer culture secrete a specific collagenase and a neutral endopeptidase into their serum-free culture medium. The rate of secretion of these two enzymes is increased after the ingestion and storage of latex particles within the vacuolar system of the cells. The increased rates of secretion of the neutral enzymes are stable for over 2 wk in the absence of a further phagocytic bout. In constrast there is little change in the extracellular levels of two lysosomal hydrolases, cathepsin D and ß-glucuronidase. The increase in the secretory rates for the two neutral enzymes is related to the number of latex particles ingested by the cells, and increases of up to 12-fold over the nonphagocytosing cultures were observed. A variety of other materials including mycostatin particles and dextran sulfate also induced increases in the secretion of collagenase. These results are discussed in relation to the turnover of connective tissue matrix macromolecules.

scholarly journals Evidence that contact with connective tissue matrix is required for normal interaction between Schwann cells and nerve fibers.

1978 ◽  
Vol 78 (3) ◽  
pp. 943-950 ◽  
Author(s):  
R P Bunge ◽  
M B Bunge
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Culture Medium ◽  
Nerve Fibers ◽  
Fetal Rat ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
Dystrophic Mice ◽  
Rat Tail ◽  
Small Nerve

Explants of fetal rat sensory ganglia, cultured under conditions allowing axon and Schwann cell outgrowth in the absence of fibroblasts, occasionally develop nerve fascicles that are partially suspended in culture medium above the collagen substrate. In these suspended regions, fascicles are abnormal in that Schwann cells are decreased in number, are confined to occasional clusters along the fascicle, provide ensheathment for only a few axons at the fascicle periphery, and do not form myelin. When these fascicles are presented with a substrate of reconstituted rat-tail collagen, Schwann cell numbers increase, ensheathment of small nerve fibers occurs normally, and larger axons are myelinated. We conclude that, for normal development, Schwann cells require contact with extracellular matrix as well as axons. The Schwann cell abnormalities in suspended fascicles are similar to those observed in nerve roots of dystrophic mice.

Structural aspects of osmoregulation in porphyra

1978 ◽  
Vol 36 (2) ◽  
pp. 412-413
Author(s):  
C. Wiencke ◽  
A. Lauchli
Keyword(s):  
Culture Medium ◽  
Point Of View ◽  
Chemical Fixation ◽  
Cellular Organization ◽  
Osmotic Adaptation ◽  
Osmotic Balance ◽  
Activity Of Enzymes ◽  
Osmotic Agents ◽  
Vacuolar System ◽  
Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

Long-Term Histologic Effects of Inferior Turbinate Laser Surgery

2001 ◽  
Vol 124 (4) ◽  
pp. 459-463 ◽  
Author(s):  
David B. Wexler ◽  
Gilead Berger ◽  
Ari Derowe ◽  
Dov Ophir
Keyword(s):  
Laser Treatment ◽  
Laser Surgery ◽  
Laser Energy ◽  
Inferior Turbinate ◽  
Surface Epithelium ◽  
Marked Diminution ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
Histologic Changes

OBJECTIVE: In this study we sought to define the histologic changes produced by laser treatment of inferior turbinates. STUDY DESIGN: Eight inferior turbinates with prior laser treatment (mean, 26.8 months) were analyzed by light microscopy after turbinectomy for relief of refractory nasal obstruction. Histologic findings were compared with those of a group of 8 hypertrophic inferior turbinates that had no previous laser surgery. RESULTS: Laser-treated areas of the inferior turbinates demonstrated a histologically bland appearance, with marked diminution of seromucinous glands and relative preponderance of connective tissue matrix. Prominence of venous sinusoids was also significantly reduced in the laser-treated areas. Surface epithelium including goblet cells was reconstituted over the areas of laser application. CONCLUSION: Clinical laser surgery of the inferior turbinate produces striking long-term histologic changes. SIGNIFICANCE: The data suggest a differential response of turbinate histologic components to application of laser energy, with the glandular component being particularly sensitive. Further correlative study is needed to clarify the clinical significance of laser-induced histologic changes in inferior turbinates.

Quantitative analysis of connective tissue matrix structure during myocardial remodeling

BIOPHYSICS ◽  
2014 ◽  
Vol 59 (5) ◽  
pp. 810-813
Author(s):  
L. T. Smoluk ◽  
A. T. Smoluk ◽  
Y. L. Protsenko
Keyword(s):  
Quantitative Analysis ◽  
Connective Tissue ◽  
Myocardial Remodeling ◽  
Matrix Structure ◽  
Connective Tissue Matrix ◽  
Tissue Matrix

Proliferation and agglutinability of primary and transformed human epithelial cells in culture

1976 ◽  
Vol 21 (3) ◽  
pp. 553-561
Author(s):  
M.A. Ricard ◽  
R.J. Hay
Keyword(s):  
Culture Medium ◽  
Monolayer Culture ◽  
Primary Cultures ◽  
Short Term ◽  
Chloromethyl Ketone ◽  
Normal Populations ◽  
Short Term Exposure ◽  
Cell Strains ◽  
Human Placentae

Primary epithelial populations (HAM) were obtained by dissociation of the amniotic membrane stripped from human placentae. Agglutinability of cells from such normal populations and of cells from the transformed epithelial line WISH was then compared using concavanalin A as mediator. Extensive similar studies have previously been reported with cell strains isolated from other species. Freshly dissociated HAM cells from primary cultures agglutinated much less readily than did cells from WISH populations. Furthermore, the former exhibited a drastic decline in agglutinability as a function of time in suspension culture after trypsinization. Short-term exposure (60 h) of HAM cells in monolayer culture to 5-bromodeoxyuridine (BrdU) elicited heightened agglutinability detectable through 22 days in vitro. Addition of the protease inhibitors n-tosyl-L-lysyl-chloromethyl ketone (TLCK) or p-tosyl-L-arginine-methyl ester (TAME) to the culture medium inhibited proliferation of the WISH line by 40–50% while effecting only a 10–15% inhibition of HAM cells. These results also confirm data with other cell species indicating that high proteolytic activity at the surface of transformed cells may be related to the rapid proliferation rate.

scholarly journals CHONDROGENESIS, STUDIED WITH THE ELECTRON MICROSCOPE

1960 ◽  
Vol 8 (3) ◽  
pp. 719-760 ◽  
Author(s):  
Gabriel C. Godman ◽  
Keith R. Porter
Keyword(s):  
Golgi Apparatus ◽  
Ground Substance ◽  
Cell Cortex ◽  
Matrix Space ◽  
Cytoplasmic Inclusions ◽  
Structural Modifications ◽  
Fetal Rat ◽  
The Matrix ◽  
Connective Tissue Matrix ◽  
Tissue Matrix

The role of the cells in the fabrication of a connective tissue matrix, and the structural modifications which accompany cytodifferentiation have been investigated in developing epiphyseal cartilage of fetal rat by means of electron microscopy. Differentiation of the prechondral mesenchymal cells to chondroblasts is marked by the acquisition of an extensive endoplasmic reticulum, enlargement and concentration of the Golgi apparatus, the appearance of membrane-bounded cytoplasmic inclusions, and the formation of specialized foci of increased density in the cell cortex. These modifications are related to the secretion of the cartilage matrix. The matrix of young hyaline cartilage consists of groups of relatively short, straight, banded collagen fibrils of 10 to 20 mµ and a dense granular component embedded in an amorphous ground substance of moderate electron density. It is postulated that the first phase of fibrillogenesis takes place at the cell cortex in dense bands or striae within the ectoplasm subjacent to the cell membrane. These can be resolved into sheaves of "primary" fibrils of about 7 to 10 mµ. They are supposedly shed (by excortication) into the matrix space between the separating chondroblasts, where they may serve as "cores" of the definitive matrix fibrils. The diameter of the fibrils may subsequently increase up to threefold, presumably by incorporation of "soluble" or tropocollagen units from the ground substance. The chondroblast also discharges into the matrix the electrondense amorphous or granular contents of vesicles derived from the Golgi apparatus, and the mixed contents of large vacuoles or blebs bounded by distinctive double membranes. Small vesicles with amorphous homogeneous contents of moderate density are expelled in toto from the chondroblasts. In their subsequent evolution to chondrocytes, both nucleus and cytoplasm of the chondroblasts undergo striking condensation. Those moving toward the osteogenic plate accumulate increasingly large stores of glycogen. In the chondrocyte, the enlarged fused Golgi vesicles with dense contents, massed in the juxtanuclear zone, are the most prominent feature of the cytoplasm. Many of these make their way to the surface to discharge their contents. The hypertrophied chondrocytes of the epiphyseal plate ultimately yield up their entire contents to the matrix.

Effects of streptozotocin-induced diabetes on rough endoplasmic reticulum and lysosomes of rat liver

1992 ◽  
Vol 263 (5) ◽  
pp. E856-E862
Author(s):  
S. E. Lenk ◽  
D. Bhat ◽  
W. Blakeney ◽  
W. A. Dunn
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Serum Proteins ◽  
Serum Insulin ◽  
Normal Serum ◽  
Lysosomal Hydrolases ◽  
Insulin Dependent ◽  
Streptozotocin Induced Diabetes ◽  
Endogenous Proteins ◽  
Vacuolar System

In the absence of amino acids and insulin, ribosome-free regions of the rough endoplasmic reticulum (RER) invaginate to form an autophagosome, which matures into an autolysosome (W. A. Dunn, Jr., J. Cell Biol. 110: 1923-1933, 1990). In this study, biochemical and morphological methods were used to examine the structure and integrity of the RER and the lysosome-vacuolar system in livers of untreated (normal serum insulin) and streptozotocin (STZ)-treated (depressed serum insulin) fed and fasted rats. Degradation of endogenous proteins was increased by 70% in STZ-treated animals. Proteolysis was further enhanced when these animals were deprived of food for 24 h. These alterations in protein turnover were accompanied by increases in the fractional volume of autophagic vacuoles and in the hepatic amounts of three lysosomal hydrolases. These effects of STZ were prevented on administration of insulin. In addition, there was an insulin-dependent 50% loss of RER surface area in livers from STZ-treated rats. This loss of structural RER was accompanied by comparable decreases in the cellular amounts of two RER membrane proteins and one luminal protein, suggesting that the RER was degraded as a unit. Additional losses of RER were observed when STZ-treated rats were fasted. Furthermore, the hepatic amounts of two serum proteins decreased, suggesting the functional capacity of the RER was reduced. Combined, the data suggest that in STZ-induced diabetes the losses in RER are related to enhanced autophagy.

Toward a kinetic theory of connective tissue micromechanics

1993 ◽  
Vol 74 (2) ◽  
pp. 665-681 ◽  
Author(s):  
S. M. Mijailovich ◽  
D. Stamenovic ◽  
J. J. Fredberg
Keyword(s):  
Connective Tissue ◽  
Three Dimensional ◽  
Elastic Fibers ◽  
Tissue Elasticity ◽  
Field Equations ◽  
Fiber Network ◽  
Rate Dependent ◽  
Connective Tissue Matrix ◽  
Tissue Matrix ◽  
And Diffusion

The aim of this study is to develop unifying concepts at the microstructural level to account for macroscopic connective tissue dynamics. We establish the hypothesis that rate-dependent and rate-independent dissipative stresses arise in the interaction among fibers in the connective tissue matrix. A quantitative theoretical analysis is specified in terms of geometry and material properties of connective tissue fibers and surrounding constituents. The analysis leads to the notion of slip and diffusion boundary layers, which become unifying concepts in understanding mechanisms that underlie connective tissue elasticity and energy dissipation during various types of loading. The complex three-dimensional fiber network is simplified to the interaction of two ideally elastic fibers that dissipate energy on slipping interface surfaces. The effects of such interactions are assumed to be expressed in the aggregate matrix. Special solutions of the field equations are obtained analytically, whereas the general solution of the model field equations is obtained numerically. The solutions lead to predictions of tissue behavior that are qualitatively, if not quantitatively, consistent with reports of a variety of dynamic moduli, their dependencies on the rate and amplitude of load application, and some features associated with preconditioning.

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