PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Connective Tissue Cells”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed1994

Identification of a 70 kD protein with sequence homology to squid neurofilament protein in glial cells of the leech CNS.

A monoclonal antibody G39, generated against a protein extract of leech central nervous system, labels specific cell types in adult, embryonic, and regenerating preparations. The antibody stained glial cells, microglial cells, and connective tissue cells, but not neurons or muscle on cryosections. The staining pattern resembled that of an intracellular network. Affinity purification of the antigen revealed a 70 kD protein. Peptide sequencing showed significant homology of a stretch of 15 amino acids to squid neural filament protein. The same mAb G39 delineated glial cells as they formed during development of the CNS and showed that the giant neuropil glial cells appear before those in the packets. The antigen recognized by mAb G39 represents a nonneuronal intermediate filament of the leech Hirudo medicinalis found in various cell-types such as glia, microglia, and some cells of the connective tissue.

Amino Acid Sequence↗
PubMed1997

Quantitative morphology of mast cells in skeletal muscle of normal and genetically dystrophic mice.

BACKGROUND: Mast cells are indigenous connective tissue cells that function in the process of inflammation and edema. Their numbers were studied in a quantitative morphological study of the soleus muscles from 32-week-old and 56-week-old normal and genetically dystrophic dy2J and mdx mice to determine the incidence of mast cells in muscle to increasing age and to normal and myopathic conditions. METHODS: Soleus muscles from normal C57B1/J and from dystrophic C57B1/SnJ (dy2J/dy2J) and C57BL/10ScSn mdx mice were processed for examination by light and electron microscopy. Quantitation of mast cells was performed on semi-thick sections and expressed as an average of cells per millimeter squared of muscle tissue. RESULTS: Mast cells were observed in the connective tissue interstitium that normally separates skeletal muscle into fascicles. Their cytoplasmic granules stained metachromatically with toluidine blue and often obscured the single, centrally placed nucleus. They occurred singly or in small groups and were most frequently seen adjacent to neurovascular elements within the muscle, and in many cases were closely associated with the outer capsular regions of muscle spindles. Between the 32- and 56-week-old groups in each strain, an age-related increase in mast cell numbers was observed. In the dystrophic conditions, the dy2J and mdx skeletal muscles exhibited a two- to four-fold increase in mast cells when compared to normals in both age groups. Extensive connective tissue proliferation and sites of necrotic and regenerating muscle were common features in both myopathies. CONCLUSIONS: Results of this study indicate that a significantly higher number of mast cells which exist in dy2J and mdx murine skeletal muscles may be related to the high amount of connective tissue infiltration and extensive muscle fiber remodelling in these conditions. Moreover, the close proximity of mast cells to muscle spindles and nerve fascicles suggests that these cells may play a role in modulating their activities.

Age Factors↗
PubMed2002

Analysis of connective tissue progenitor cell behavior on polydimethylsiloxane smooth and channel micro-textures.

Growth of human connective tissue progenitor cells (CTPs) was characterized on smooth and microtextured polydimethylsiloxane (PDMS) surfaces. Human bone marrow derived cells were cultured for nine days under conditions promoting osteoblastic differentiation on Smooth PDMS and PDMS Channel microtextures (11 microm high, 45 microm wide channels, and separated by 5 microm wide ridges). Glass tissue culture dish surfaces were used as controls. Cell numbers per colony, cell density within colonies, alignment of cells, area of colonies, and colony shapes were determined as a function of substrate surface topography. An alkaline phosphatase stain was used as a marker for osteoblastic phenotype. CTPs attached, proliferated, and differentiated on all surfaces with cell process lengths of up to 80 microm. Cells on the Smooth PDMS and control surfaces spread and proliferated as colonies in proximity to other cells and migrated in random directions creating colonies that covered significantly larger areas (0.96 and 1.05 mm(2), respectively) than colonies formed on PDMS Channel textures (0.64 mm(2)). In contrast, cells on PDMS Channel textures spread, proliferated, aligned along the channel axis, and created colonies that were more dense, and with lengths of longest colony axes that were significantly longer (3252 microm) than those on the Smooth PDMS (1265 microm) and control surfaces (1319 microm). Cells on PDMS Channel textures were aligned at an angle of 14.44 degrees relative to the channel axis, and the resulting colonies exhibited a significantly higher aspect ratio (13.72) compared to Smooth PDMS (1.57) and control surfaces (1.51).

Journal Article↗
PubMed1997

Immunolocalization of bFGF in pterygia: association with mast cells.

PURPOSE: To examine the expression of basic fibroblast growth factor in pterygia and determine whether mast cells contain basic fibroblast growth factor (bFGF) in this disease process. METHODS: Formalin-fixed paraffin-embedded tissue samples of pterygia (n = 14) were used to study the expression of bFGF with immunohistochemistry. Seven samples were also double labeled with specific antibodies to bFGF and tryptase (a specific mast cell marker). RESULTS: In all tissue samples examined, bFGF was specifically localized in blood vessels, epithelium, and a subset of connective tissue cells. The majority of bFGF-positive connective tissue cells were also tryptase positive (90.4 +/- 3.6%). Nearly all the tryptase-positive cells (mast cells) in the pterygia tissues coexpressed bFGF (98 +/- 1.5%). CONCLUSIONS: These findings suggest that bFGF may have biologic effects on the epithelium and blood vessels in pterygia, with epithelial and endothelial cells as a possible source. In addition, mast cells contain bFGF in the pterygia tissues examined in this study. The mast cells may serve as an additional source of bFGF, possibly modulating a variety of cell types as well as the extracellular matrix in pterygia.

Adult↗
PubMed1985

Chemoattractants in fibrotic disorders.

Fibrosis represents an excessive deposition of connective tissue which impedes the normal functions of an organ or tissue. The mechanisms leading to this increased deposition of connective tissue may be similar to those occurring in normal wound repair. We have previously shown that the repair process involves the migration of connective tissue cells to the site of injury and their subsequent proliferation. One of the principal factors controlling these events appears to be the platelet-derived growth factor (PDGF). PDGF acts as a potent chemoattractant and mitogen for connective tissue cells but not other cell types. In addition to PDGF, factors produced by monocytes and tissue macrophages also act as chemoattractants for connective tissue cells. These observations suggest that such activities may be abundant in areas of inflammation. In normal repair these factors would be present for a relatively short period of time, whereas in fibrosis the chronic inflammatory response could maintain a constant or repeated release of such factors. This would recruit additional connective tissue cells to the area of inflammation, changing the cellular composition of the affected organ or tissue, resulting in an expansive and permanent nodule of connective tissue.

Animals↗
PubMed1975

Changes in numbers of acidophilic and basophilic connective tissue granulated cells in the intestine of the rat during the estrous cycle.

Changes in physiological reproductive states of female Long-Evans hooded rats were directly correlated with changes in the concentration of acidophilic and basophilic connective tissue granulated cells in the lamina propria of the duodenum. Acidophilic granulated cell numbers were significantly higher at estrus and metestrus than at other stages of the estrous cycle or in the immature state. apcidophilic granulated cell numbers during pregnancy were not significantly different from cell numbers quantified during metestrus, diestrus, or proestrus, but were significantly lower than cell numbers during estrus. Late lactation (21-25 days) was associated with significant decreases in the numbers of acidophilic granulated cells from numbers observed during the estrous cycle and during pregnancy. Basophilic granulated cell numbers did not differ significantly during the estrous cycle, although the highest numbers were observed during proestrus. Basophilic granulated cell numbers were significantly higher during pregnancy than during the estrous cycle. Basophilic granulated cell counts in late lactation were comparable to numbers quantified in estrus, metestrus, and diestrus, but were significantly lower than during proestrus and pregnancy.

Animals↗
PubMed1984

Development of human connective tissue mast cells from purified blood monocytes.

Highly purified subfractions of human peripheral blood monocytes, when cultured in the presence of 30% L cell supernatant and 30% horse serum, assumed all the characteristics that define human connective tissue mast cells. After three weeks of culture, 75% of the cells developed metachromasia and granular chloroacetate esterase staining, and their intracellular histamine levels increased from 0.0 to 50.5 ng/10(6) cells. On electron microscopy, the cells developed intracytoplasmic granules with all the features typical for mature and immature mast cells. Cultured cells bound 55 pg 125I-IgE/10(6) cells, while labelling was negligible with cells prior to culture and with heat-denatured 125I-IgE. Fluorescent staining with anti-IgE increased slightly as well, while staining with monoclonal anti-monocyte and anti-HLA-Dr markers decreased. Purified lymphocytes did not assume mast cell characteristics, and lymphokines did not induce or enhance in vitro mast cell development or IgE binding. The data therefore further support the concept that connective tissue mast cells arise from the monocytoid lineage.

Binding Sites, Antibody↗
PubMed1987

The embryonic origin of connective tissue mast cells.

To find out whether mast cells are derived from the neural crest or from mesoderm, explants of avian blastoderm, from which the neural crest was excluded, were grown on the chorio-allantoic membrane of chick hosts. The grafts were fixed in aldehyde fixatives and stained to demonstrate metachromatic connective tissue mast cells. In grafts of chick endoderm and mesoderm, mast cells were present despite the absence of neural crest derivatives. To ascertain whether these mast cells were perhaps of host origin, in a second experiment quail embryos were used as donors; explants included all three germ layers and were delimited so as to exclude neural crest cells. The proportion of the mast cells present that showed very large nucleoli such as are characteristic of quail cells was far in excess of that observed in mast cells of a young chick and much closer to that seen in these cells in a young quail. The same was true for grafts in which quail mesoderm had been combined with chick endoderm. Taken together, the results show that connective tissue mast cells are mesodermal rather than neural crest in origin.

Animals↗
PubMedDate not supplied

Enzyme-histochemical detection of a chymase-like proteinase within bovine mucosal and connective tissue mast cells.

The presence of chymase-like proteinase in bovine mast cells was investigated by an enzyme-histochemical technique (naphthol-AS-D-chloroacetate as substrate) in normal skin, primary bronchus, lung and duodenum. The counts and distribution of chymase-positive and toluidine blue-positive mast cells were compared by means of successive staining. Mast cells with chymase-like activity were detected in all areas, but their proportion was greater in connective than mucosal tissues, with the exception of the skin. These results contrast with those obtained in rodents, in which chymase-like proteinases are detected in all tissues and also in all mast cells. Bovine mast cells are closer to those of human beings, in which chymase-containing mast cells predominate in connective tissues, including skin. The results suggest that more than one chymase subset is present, at least in duodenum. The possible occurrence of dual-specific chymase mast cells, as in other ruminants, is discussed.

Animals↗
PubMed1975

Uptake of colloidal thorium dioxide by the mouse connective tissue mast cell.

The ability of the mouse mast cell to phagocytize colloidal thorium dioxide, Thorotrast, was investigated employing the mouse connective tissue air pouch. The connective tissue mast cell of mouse was found to have limited capability to ingest the particulate Thorotrast in comparison to the rat peritoneal mast cell which ingested this material readily. Fibroblasts and macrophages in the connective tissue removed injected Thorotrast very rapidly in contrast to mast cells that demonstrated limited phagocytic capabilities. The tissue mast cell of the mouse, therefore, should not be considered a part of the reticuloendothelial system.

Animals↗
PubMed1983

Fibroblast prostaglandin E2 synthesis. Persistence of an abnormal phenotype after short-term exposure to mononuclear cell products.

Acquired abnormalities of connective tissue metabolism in inflammatory diseases often persist when lesional tissue is maintained in in vitro culture. Although connective tissue cells are exposed to inflammatory cell-derived mediators in vivo and such mediators have been shown to alter connective tissue cell behavior, it is unclear whether the persistence of metabolic defects in vitro could result from remote in vivo exposure to these mediators. An in vitro model was used to test whether transient exposure of normal fibroblasts to inflammatory mediators could lead to metabolic alterations that persist during in vitro culture. Short-term exposure of human foreskin fibroblasts in vitro to supernates of mitogen-activated peripheral blood mononuclear cells led to persistent abnormalities of prostaglandin E2 (PGE2) metabolism. Fibroblasts previously exposed to mononuclear cell products synthesized more than twice as much PGE2 when stimulated compared with similarly stimulated but previously unexposed control fibroblasts of the same strain. The enhanced PGE2 synthesis persisted for as long as 20 wk and 19 cell generations after the original exposure to mononuclear cell products. Exposure of fibroblast populations to mononuclear cell products may, thus, lead to metabolite alterations that are still evident after multiple cell generations.

Cell Division↗
PubMed1992

Glucocorticoid effects on rabbit fetal lung maturation in vivo: an ultrastructural morphometric study.

Maternal administration of glucocorticoids is known to stimulate fetal lung maturation. In the present study, we used microscopy and stereology to evaluate the morphological effects of maternal glucocorticoid treatment on rabbit fetal lung tissue. Betamethasone was administered to pregnant rabbits on days 25 and 26 of gestation at a dose of 0.2 mg/kg body weight. The animals were sacrificed on day 27 of gestation. Glucocorticoid treatment significantly increased the presumptive airspace in the fetal lung tissue but did not alter the relative proportion of epithelium, connective tissue, or vasculature in the tissue. In addition, glucocorticoid treatment significantly increased the proportion of type II cells in the prealveolar epithelium, increased the rate of phosphatidylcholine synthesis, and increased the content of the major surfactant-associated protein, SP-A, in the fetal lung tissue. We could detect no effect of betamethasone on lamellar body cross-sectional area, numerical density, or volume density within fetal lung type II cells. Glucocorticoid treatment of the pregnant doe caused a decrease in the volume density of intracellular glycogen and an increase in the volume density of mitochondria in fetal lung type II cells. Betamethasone treatment did not alter the distance between fetal lung epithelial cells and subadjacent connective tissue cells. However, glucocorticoid treatment increased the number of connective tissue foot processes that pierced the epithelial basal lamina. Thus, glucocorticoid treatment of the pregnant doe results in structural changes in the fetal lung tissue, an acceleration of some aspects of type II cell differentiation, and a concomitant increase in epithelial-mesenchymal interactions.

Animals↗
PubMed1995

Ultrastructural findings in the vestibular end-organs of AIDS cases.

Neurotologic manifestations are apparent in human immunodeficiency virus (HIV) infection, but are poorly understood. Symptoms related to the vestibular system include episodes of vertigo, imbalance, ataxia, and nausea. Although patients present more often with hearing impairment, vestibular complaints are described and electrophysiologic studies indicate vestibular dysfunction in HIV-infected patients. Whether the disease involvement includes the central, or the peripheral nervous system has not been established. Ultrastructural analysis of vestibular end-organs obtained from HIV autopsy cases revealed pathologic changes in the labyrinth wall, the epithelial lining, and the receptor maculae and cristae. Cytologic changes in hair cells included inclusion bodies, viral-like particles, and hair bundle malformations. Epithelial lining cells, supporting cells, and connective tissue cells had inclusions and viral-like particles. These findings are consistent with those of a previous cochlear study demonstrating intracellular viral-like particles with the morphologic characteristics of HIV. Further cytologic evaluation of decalcified temporal bones and immunohistochemical analysis of freshly harvested HIV-infected temporal bones may provide further insight into the pathogenesis of viral-induced hearing loss and vestibular impairment.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Characterization of whole-cell currents in mucosal and connective tissue rat mast cells using amphotericin-B-perforated patches and temperature control.

Rat mucosal type mast cells are thought to possess only a K+-selective inwardly rectifying (IRK) current in the resting state. We used rat-bone-marrow-derived mast cells (BMMCs) as a model of mucosal mast cells and recorded whole-cell membrane currents from cells perforated with amphotericin B. Under these conditions, both inwardly rectifying (IR) and outwardly rectifying (OR) currents were observed. The reversal potential and conductance of the IR current depended on the extracellular K+ concentration, indicating that the channel was K+ selective. The OR current was not affected by changes in extracellular K+ concentration, but lowering extracellular Cl- concentration reduced the conductance and shifted the reversal potential in a positive direction. The OR current was not affected by K+ channel blockers, but was reversibly blocked by the chloride channel blocker 4,4'-diisothiocyanato-2,2'-stilbenedisulphonate (DIDS), again indicating a Cl- conductance. The IRK current was also detected in the majority of cells using the conventional whole-cell recording configuration at room temperature. In contrast, the ORCl current was only observed in 7% of recordings made at room temperature with the conventional whole-cell voltage-clamp mode, but was detected in 66% of cells if the bath temperature was increased and the integrity of the cell's cytoplasm was preserved by using the perforated-patch technique. Under similar conditions, the ORCl current was also present in rat peritoneal mast cells, a connective tissue phenotype previously thought to have no whole-cell currents in the resting state. The role of this current and factors affecting its activation are discussed.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1989

Observation of production of immunoactive prolactin by normal human connective tissue in cell culture.

Data from our in vitro studies indicate a new source of prolactin (PRL)-like activity, normal human connective tissue. Fascial cells from primary culture and subsequent passages produced an extracellular antigen which specifically reacted in a radioimmunoassay RIA developed to detect human pituitary PRL. An initial peak or first surge of fascial PRL-like activity occurred between 4 and 15 d in primary culture. Ibuprofen, cytotoxic levels of 0.01% azide, or 7.5 mM EDTA and medium lacking serum [fetal bovine serum (FBS)] significantly (P less than or equal to 0.05) reduced PRL-like activity levels, whereas female steroids, 257 to 342 milliosmolarity, 1 to 3.6 mg/ml glucose, 2 to 20% FBS, and dialyzed FBS (MWCO approximately 1 kDa) were without effect. Optimum production of PRL-like activity occurred at pH 7.3. A second surge began after 18 d and continued until passage indicating that perhaps two populations of cells produced PRL-like activity in primary culture. Production of PRL-like activity by cells from early passages (1 and 2) became detectable at confluence, was serum-dependent, showed two patterns (tonic, rising to plateau), and averaged 3.2 fg.cell-1.3 d-1 feed interval. Cells from late passages showed morphologic damage from repetitive trypsinization, aging, and reduced production of PRL-like activity with aberrant production pattern. Production of PRL-like activity was maintained in an unusual long-term culture. These in vitro studies demonstrate the most recently recognized and ubiquitous source of human extrapituitary PRL or PRL-like activity, normal connective tissue (fascia).

Abdominal Muscles↗
PubMed2006

Hypoxic regulation of stability of connective tissue growth factor/CCN2 mRNA by 3'-untranslated region interacting with a cellular protein in human chondrosarcoma cells.

Connective tissue growth factor (CTGF/CCN2) can be induced by various forms of stress such as exposure to high glucose, mechanical load, or hypoxia. Here, we investigated the molecular mechanism involved in the induction of ctgf/ccn2 by hypoxia in a human chondrosarcoma cell line, HCS-2/8. Hypoxia increased the ctgf/ccn2 mRNA level by altering the 3'-untranslated region (UTR)-mediated mRNA stability without requiring de novo protein synthesis. After a series of extensive analyses, we eventually found that the cis-repressive element of 84 bases within the 3'-UTR specifically bound to a cytoplasmic/nuclear protein. By conducting a UV crosslinking assay, we found the cytoplasmic/nuclear protein to be a 35 kDa molecule that bound to the cis-element in a hypoxia-inducible manner. These results suggest that a cis-element in the 3'-UTR of ctgf/ccn2 mRNA and trans-factor counterpart(s) play an important role in the post-transcriptional regulation by determining the stability of ctgf/ccn2 mRNA.

3' Untranslated Regions↗