PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Connective Tissue”

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 577 records · Page 32Linked to original sources
PubMed1993

Pluripotent mesenchymal stem cells reside within avian connective tissue matrices.

Recent studies have noted the presence of putative stem cells derived from the connective tissues associated with skeletal muscle, heart, and dermis. Long-term continuous cultures of these cells from each tissue demonstrated five distinct phenotypes of mesodermal origin, i.e. muscle, fat, cartilage, bone, and connective tissue. Clonal analysis was performed to determine whether these morphologies were the result of a mixed population of lineage-committed stem cells or the differentiation of pluripotent stem cells or both. Putative stem cells from four tissues (skeletal muscle, dermis, atria, and ventricle) were isolated and cloned. Combined, 1158 clones were generated from the initial cloning and two subsequent subclonings. Plating efficiency approximated 5.8%. Approximately 70% of the 1158 clones displayed a pure stellate morphology, while the remaining clones contained a mixture of stellate, chondrogenic- or osteogenic-like morphologies or both. When cultured in the presence of dexamethasone, cells from all clones differentiated in a time- and concentration-dependent manner into muscle, fat, cartilage, and bone. These results suggest that pluripotent mesenchymal stem cells are present within the connective tissues of skeletal muscle, dermis, and heart and may prove useful for studies concerning the regulation of stem cell differentiation, wound healing, and tissue restoration, replacement and repair.

Animals↗
PubMed2006

Intravenous immunoglobulin treatment in vasculitis and connective tissue disorders.

Vasculitis syndromes and connective tissue disorders are heterogeneous and mostly rare multisystem disorders with various autoimmune mechanisms driving tissue inflammation and remodeling, ischemic and hemorrhagic tissue damage. While the nervous system can be affected by most of these diseases, the pathogenesis for neural involvement is often ambiguous and elusive for the clinician. Intravenous immunoglobulins (IVIG) have been used for the treatment of most of these disorders. However, a thorough review of the literature indicates that the role for IVIG has to be discussed for individual entities, has often only anecdotal evidence, and is particularly hard to define with respect to neurological manifestations. This review gathers the available evidence on the efficacy of IVIG in neurologically relevant rheumatic diseases, leading to recommendations for their clinical use.

Connective Tissue Diseases↗
PubMed2000

Mixed connective tissue disease: overlap syndromes.

Since the original description of mixed connective tissue disease (MCTD) as an apparently unique syndrome by Sharp and co-workers, the concept of MCTD has been highly controversial. In this chapter, a quarter of a decade later, we examine the evidence that MCTD is a distinctive entity rather than a haphazard association of clinical and serological features and that the presence of high titres of autoantibodies to UIRNP influences the expression of connective tissue disease in ways that are relevant to prognosis and treatment. Results of longterm clinical studies are presented, which show that the clinical phenotype of MCTD is robust and can be defined by classification criteria that show reasonable sensitivity and specificity. In addition, the chapter addresses the results of immunogenetic and serological studies that demonstrate that MCTD is quite distinctive from systemic lupus erythematosus and systemic sclerosis. Indeed, there is good evidence that the clinical and serological features of MCTD are not just a haphazard association but that these patients represent a distinctive subset of connective tissue disease in which the specific autoimmune response is relevant to clinical expression and to understanding the underlying pathogenesis.

Autoantibodies↗
PubMed1982

Anti-nuclear matrix antibodies in mixed connective tissue disease.

Purified serum antibodies of patients suffering from mixed connective tissue disease were tested for their immunological specificity against nuclear constituents of HeLa S3 cells. In the indirect immunofluorescent staining technique, using cells and nuclei as targets, a typical speckled intranuclear staining pattern was obtained, that persisted after degradation and extraction of all nucleic acids and their associated proteins. This treatment of nuclei with detergents, DNase, RNase and high salt concentrations leave intact only the so-called nuclear matrix which is an intranuclear proteinaceous network. Further proof that nuclear matrix proteins were targets of the autoimmune reaction was obtained after separation of these proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis and electrophoretic transfer to nitrocellulose (blotting). A specific number of blot-transferred matrix proteins reacted with purified serum antibodies of 10 patients with mixed connective tissue disease, whereas this reaction was negative with normal healthy individuals. IgG preparations of 7 patients with systemic lupus erythematosus showed a weak, if any, reaction with matrix constituents. Obviously, in some connective tissue diseases serum antibodies are expressed which are directed to specific nuclear matrix antigens.

Autoantibodies↗
PubMed1982

Cytofilaments and fibroblast junctions in the benign proliferation of connective tissue.

Benign proliferative patterns of connective tissue in the dermatofibroma are investigated. Neoplastic fibroblasts are similar to so-called myofibroblasts. However, filaments are the prevalent filamentous component, while microfilaments and microtubules are present in limited amounts. In addition, no junctions are observed between adjacent cells. Typical mast cells and histiocytes are rarely observed. This report adds evidence of the similarity between the neoplastic and inflammatory patterns of fibroblastic proliferation, and suggests that the proliferation of the active fibroblast of the dermatofibroma (viewed as an intermediate cell between the common fibroblast and the myofibroblast) does not lead to the development of a homodynamic system. It also confirms that this tumor may exist in a stable condition.

Adult↗
PubMed2003

Comparison of prostaglandin F2alpha, bimatoprost (prostamide), and butaprost (EP2 agonist) on Cyr61 and connective tissue growth factor gene expression.

Connective tissue growth factor (CTGF) and Cyr61 (cysteine-rich angiogenic protein 61) are members of the CCN gene family that encode multifunctional, extracellular matrix-associated signaling proteins. Because the mechanism of action of certain anti-glaucoma drugs involves extracellular matrix remodeling of ocular ciliary muscle, with a resultant increase in drainage of aqueous humor from the eye, we compared the effects of three pharmacologically distinct ocular hypotensive agents on Cyr61 and CTGF gene expression. Thus, prostaglandin F2alpha (PGF2alpha) (FP receptor agonist), Butaprost (EP2 receptor agonist), and Bimatoprost (a prostamide) were compared. Using Affymetrix gene chip technology, we first identified that PGF2alpha dramatically up-regulated Cyr61 and CTGF mRNA expression in HEK 293/EBNA cells (hFP-HEK 293/EBNA). Northern blot further confirmed the Cyr61 and CTGF up-regulation is in a dose- and time-dependent manner. PGF2alpha-induced up-regulation of Cyr61 appeared to exclusively involve the Rho pathway, and up-regulation of CTGF was via multiple intracellular pathways. Because prostamide receptors are, to date, defined only at the pharmacological level, Bimatoprost effects on Cyr61 and CTGF were studied in the isolated feline iris sphincter preparation, a tissue highly responsive to prostamides. Both PGF2alpha and Bimatoprost up-regulated Cyr61 mRNA expression in the cat iris tissue. Only PGF2alpha up-regulated CTGF mRNA expression in the cat iris. Therefore, PGF2alpha and Bimatoprost appear to interact with different receptors populations in the cat iris, according to their markedly different effects on CTGF. Activation of prostaglandin EP2 receptors (Gs-coupled) also up-regulated Cyr61 but not CTGF mRNA expression in the isolated cat iris. Similar data were observed in human primary ciliary smooth muscle cells. Thus, despite quite different signal transduction pathways, FP receptor stimulation up-regulates CTGF and Cyr61. The prostamide analog Bimatoprost and an EP2-selective agonist affects only Cyr61.

Alprostadil↗
PubMed1992

Lungs in mixed connective tissue disease.

Patients with mixed connective tissue disease (MCTD) exhibit clinical features of systemic lupus erythematosus (SLE), progressive systemic sclerosis or scleroderma (PSS), and polymyositis-dermatomyositis (PM-DM). In their sera is an unusually high titer of a circulating antinuclear antibody with specificity for a nuclear ribonucleoprotein antigen. Pleuropulmonary manifestations are common in MCTD and the incidence varies from 20% to 85%. The pleuropulmonary complications include pleural effusion, interstitial pulmonary processes, pulmonary arterial hypertension (PAH), pulmonary vasculitis, pulmonary thromboembolic phenomena, aspiration pneumonia, and hypoventilatory failure. Pulmonary vascular pathology with progressive PAH and cor pulmonale is the most serious complication of MCTD. The pleuropulmonary manifestations in MCTD are similar to the respiratory problems well recorded in SLE, PSS, and PM-DM. Even though the pleuropulmonary complications are common in MCTD, they may remain clinically inapparent until fatal complications ensue.

Humans↗
PubMed2000

The lack of compound 48/80-induced contraction in isolated trachea of mast cell-deficient Ws/Ws rats in vitro: the role of connective tissue mast cells.

In the rat trachea, two types of mast cells have been identified, connective tissue mast cells and mucosal mast cells. Their different characteristics may account for their different biological functions. The role of connective tissue mast cells in tracheal contraction as one feature of the immediate reaction of asthma was studied in vitro in isolated trachea, using tissue derived from mast cell-deficient (Ws/Ws) rats, heterozygous (Ws/+) rats and control (+/+) rats, and compound 48/80 as a potent inducer of mast cell degranulation. The contractile response of tracheas from the three types of rats was also studied upon exposure to the following spasmogens: histamine, 5-hydroxytryptamine (5-HT), and carbachol. Histamine content in tissues reflected the differing mast cell numbers in strips from the three rat types. It was found that carbachol and 5-HT elicited tracheal contraction in a similar manner in strips from the three types of rats. Histamine had no contractile effect. Compound 48/80, at a dose of 25 microg/ml, elicited contraction in tracheas from both control (+/+) and heterozygous (Ws/+), but not in trachea from Ws/Ws rats. Compound 48/80-induced contractions in tracheas from +/+ rats were inhibited by 0.1 microM ketanserin and 0.1 microM nedocromil, but not by 0.1 microM mepyramine. Enzyme histochemistry confirmed that the degranulation occurred in connective tissue mast cells, but not in mucosal mast cells. We concluded that connective tissue mast cells play an important role in rat tracheal contraction via 5-HT release induced by compound 48/80. In addition, the specific mast cell-deficient (Ws/Ws) rats provide a good tool for studying the roles of mast cells in airway system.

Animals↗
PubMed1994

Listeriosis in patients with connective tissue diseases.

OBJECTIVE: Patients with connective tissue diseases (CTD) are prone to infections, either from the disease itself or secondary to treatment. The incidence of listeriosis in immunosuppressed patients is increasing. We therefore evaluated the frequency of listeriosis, an otherwise rarely reported infection in the rheumatologic literature, in patients with CTD. METHODS: Retrospective analysis of listeria positive cultures in patients with CTD between 1982 and 1992 at a tertiary care center in Mexico City. RESULTS: We identified 8 patients: 7 with systemic lupus erythematosus and one with dermatomyositis. At the time of the infection, 5 had active disease, 6 were receiving prednisone and/or other immunosuppressive drugs and 2 were receiving hemodialysis. L. monocytogenes was isolated from cerebrospinal fluid (5 patients), from blood (one patient) and from both sites (2 patients). Patients had bacteremia without a known focus of infection or meningitis as the 2 most common clinical forms of listeriosis. In spite of appropriate antibiotic therapy, 4 patients died. CONCLUSION: As in other immunosuppressed individuals, listeriosis is an aggressive infection in patients with CTD. Although rare, listeriosis should be included in the differential diagnosis of meningitis in patients with CTD and appropriate aggressive therapy rapidly instituted. To determine its frequency in rheumatic patients, multicentric prospective studies are required.

Adult↗
PubMed1999

Comparative clinical study of a bioabsorbable membrane and subepithelial connective tissue graft in the treatment of human gingival recession.

BACKGROUND: Connective tissue grafts and guided tissue regeneration (GTR) are the most current procedures in the treatment of gingival recession, but very few clinical comparative studies have been conducted. METHODS: The purpose of this study was to compare 2 types of treatment of gingival recession in the same patients. Fourteen pairs of Miller Class I defects were selected in 14 patients. In each pair, one recession was randomly assigned for treatment by GTR using a bioabsorbable membrane, and the other treated by subepithelial connective tissue graft (CTG). Height of recession (HR), clinical attachment level (CAL), probing sulcus depth (PSD), height of keratinized tissue (HKT), and distance from the cemento-enamel junction to the mucogingival junction (CEJ-MGJ) were recorded before surgery and 6 months postoperatively. RESULTS: The initial width and height of recession were, respectively, 3.73 mm (SD 0.56) and 3.85 mm (SD 1.15) for the CTG group, and 4.04 mm (SD 0.92) and 4.28 mm (SD 1.20) for the GTR group. The differences were not significant. CAL changes were not different. Both in the CTG group and in the GTR group, mean HR reduction was 2.89 mm (SD 1.18), representing a mean root coverage of 76% and 70.2%, respectively. The difference was not significant. HKT mean gain was significantly greater (P = 0.0001) with CTG (2.03 mm, SD 0.92) than with GTR (0.42 mm, SD 0.91). The GTR technique displaced the mucogingival junction significantly (P = 0.007) more coronally (2.35 mm, SD 1.44) than the CTG technique (0.78 mm, SD 1.23). CONCLUSIONS: Within the limits of this study, no difference could be found between subepithelial connective tissue graft and GTR with a bioabsorbable membrane with regard to root coverage, but the GTR technique did not increase the height of keratinized tissue and displaced the mucogingival junction more coronally at 6 months.

Absorption↗
PubMedDate not supplied

The interaction between host-supplied connective tissue and xenografted human tumor cells.

The scope of the present study was to investigate the interaction between human tumor cells heterotransplanted to athymic mice and the connective tissue supplied by the host animals. Thirteen human tumors of different origin and various histological types were analyzed by light and electron microscopy between days 1 and 30 after transplantation. Constant patterns of histological and ultrastructural changes were observed within all tumors investigated which were characterized by different histological type and varying growth velocity. Following an initial dying of most inoculated tumor cells, host-supplied inflammatory cells immigrated into the xenografts and phagocytozed the necrotic and degenerating tumor cells. Fibroblasts which produced vivaciously collagenous material invaded the xenografts and built up solid strands of connective tissue radiating from the periphery into the xenografts. These cords of connective tissue tightly contacted surviving tumor cells and were used as guide-rails for ingrowing capillaries. Immediately after their immigration into the fibrous strands, first mitoses of tumor cells occurred in close proximity to capillary-conducting strands of connective tissue, resulting in a revival of tumor cell proliferation at first near to the fibrous cords and a spreading of newly formed tumor cells along the strands of connective tissue. These results indicate that the host-supplied connective tissue plays an important role in tumor cell proliferation and local tumor expansion.

Animals↗
PubMed1985

Alteration of the connective tissue network of striated muscle in copper deficient rats.

The connective tissue network in striated muscle, consisting principally of collagen is arranged in a three dimensional network and is intimately associated with muscle function. Previous studies have shown that animals maintained on a copper-deficient diet undergo myocardial hypertrophy and exhibit cardiovascular lesions such as ventricular aneurysms that eventually rupture. A deficiency of copper in the diet is known to inhibit lysyl oxidase, a metalloenzyme requiring copper as a cofactor and which is also responsible for collagen and elastin crosslinking. Examination by scanning and transmission electron microscopy of skeletal and cardiac muscle from rats maintained on copper-deficient diets showed both gross and microscopic lesions to the connective tissue network. Immunohistochemical staining by light microscopy with antibodies against lysyl oxidase showed that the enzyme was equally present in both control and experimental animals. Fluorescent staining for antibodies against collagen types I and III showed similar results. From these studies we concluded that the collagen secreted during hypertrophy was not crosslinked by lysyl oxidase due to the absence of the copper cofactor. This resulted in the failure of the connective tissue network to transmit and distribute the increased force associated with myocardial hypertrophy and resulted in myocardial aneurysms.

Animals↗
PubMed1985

Biochemical composition of the connective tissue in keloids and analysis of collagen metabolism in keloid fibroblast cultures.

Keloids are histologically characterized by an abundance of the extracellular matrix of connective tissue. In the present study, we examined the connective tissue composition of keloids, and analyzed the details of collagen metabolism utilizing fibroblast cultures established from keloid tissue. Quantitative connective tissue analyses indicated that collagen was the predominant extracellular matrix component in keloids. The ratio of genetically distinct collagens type I/III was significantly increased, as compared to normal human skin. Collagen biosynthesis was measured in fibroblast cultures by the formation of radioactive hydroxyproline: 5 of 9 keloid cell cultures studied demonstrated increased procollagen production in comparison to age-, sex-, and passage-matched control skin fibroblast lines, while the remaining 4 cell lines were within the control range. Keloid fibroblast cultures which were high collagen producers also demonstrated elevated prolyl hydroxylase activity. The mechanisms of increased procollagen production in fibroblast cultures were first examined by assaying the abundance of type I procollagen-specific mRNA utilizing dot blot hybridizations with a pro alpha 2(I)-chain-specific cDNA. The type I procollagen mRNA levels were significantly increased in 4 keloid fibroblast lines, and a good correlation between the mRNA levels and the rate of procollagen production in the same cultures was noted. These observations suggest regulation of the collagen gene expression on the transcriptional level. The catabolic pathway of collagen metabolism in fibroblast cultures was examined by determining the degradation of newly synthesized procollagen polypeptides through assay of radioactive hydroxyproline in small-molecular-weight peptide fragments. In 3 keloid cell cultures, the degradation of newly synthesized collagen polypeptides was below the range of normal controls. These findings suggest that a reduced degradation of newly synthesized polypeptides might contribute to the accumulation of procollagen in some keloid fibroblast cultures. The results of this study suggest two possible mechanisms for deposition of collagen in keloid lesions in vivo: first, the growth of the lesions may result from a localized loss of control of the extracellular matrix production by fibroblasts; secondly, reduced degradation of the newly synthesized procollagen polypeptides may contribute to collagen deposition in some keloids.

Adult↗
PubMedDate not supplied

[Morphologic study of the microcirculation in connective tissue diseases].

Capillaroscopy is a non-invasive diagnostic test used to study microvascular abnormalities which are present in many disorders, particularly some rheumatic pathologies, such as connective tissue diseases. In systemic sclerosis, capillaroscopy allows detection of pathognomonic microvascular alterations. In other connective tissue diseases, including systemic lupus erythematosus, dermatopolymyositis, undifferentiated connective tissue diseases, and mixed connective tissue disease, the capillaroscopic patterns, although non-specific, can provide a valid support for the diagnosis. In Raynaud's phenomenon, capillaroscopy enables detection of early microvascular abnormalities that are useful for preclinical diagnosis of secondary Raynaud's phenomenon.

Connective Tissue Diseases↗
PubMed2003

The ultrastructure of periductal connective tissue and distinctive populations of collagen fibrils associated with ductal epithelia of exocrine glands.

The ultrastructure of the connective tissue around the intraglandular ducts was observed in rat exocrine glands. Connective tissue with a dense population of collagen fibrils was found either around the ducts and blood vessels (perivasculoductal connective tissue; PVDCT) as in the lacrimal and salivary glands and liver, or solely surrounding the ducts (periductal connective tissue; PDCT) as in the exocrine pancreas, whereas the interlobular and intralobular interstitium of the glands-except for the liver-contained substantially fluid-filled spaces without collagen fibrils. The PVDCT and PDCT of these glands contained two populations of collagen fibrils-fibroblast-associated and epithelium-associated-although the development and density of these fibrils varied considerably in individual glands. Both populations of collagen fibrils were most developed in the lacrimal glands, in which the basal aspects of the ductal epithelium and the basement membrane showed considerable undulation associated with a distinctive peribasement membrane zone with amorphous matter and a small population of the fibrils. In the parotid and submandibular glands, both populations were distinct, though poorly developed. In the exocrine pancreas and hepatic Glisson's sheath, the two populations of collagen fibrils were moderately developed, and the basal aspects of the ductal epithelium were characterized by prominent invaginations in which the multilaminar basement membranes and the epithelium-associated collagen fibrils were frequently engulfed. These observations provide evidence that the two populations of collagen fibrils around the ducts are found universally in exocrine glands, and support the hypothesis of the collagen fibril-synthesizing and -secreting ability of ductal epithelial cells.

Animals↗
PubMed2005

[Interstitial lung disease related to systemic connective tissue diseases].

Interstitial lung disease (ILD) is one of the most frequent and most serious complications of connective tissue diseases such as systemic sclerosis, systemic lupus erythematosus, dermato- and polymyositis, Sjogren's syndrome, or mixed connective tissue disease. Diagnosis of ILD is often delayed in patients with connective tissue diseases because of the systemic character of the primary condition, restricted physical activity of the patient and insufficient awareness of the physycian. The aim of the current review is to present the up-to-date information on ethiopathology, classification, diagnosis and treatment of ILD in patients with connective tissue diseases.

Collagen Diseases↗
PubMedDate not supplied

Mechanisms of TGF-beta action in connective tissue repair of rat mesenteric wounds.

We have recently reported that transforming growth factor-beta stimulates genuine connective tissue repair in the perforated rat mesentery and that this stimulation is not caused by increased macrophage chemotaxis. To further characterize the effect of transforming growth factor-beta(1) on the enhanced rate of wound closure, we performed a series of morphometric analyses with determination of mitotic index, fibroblast labeling index, cellular density, neovascularization, and scar tissue formation. Actin expression close to the wound margin was also evaluated morphologically. Fibroblast cell proliferation was not stimulated by transforming growth factor-beta(1) in either wounded or unwounded tissue. Transforming growth factor-beta(1) did, however, significantly increase the formation of healing tissue postoperative days 5 to 10 (p < 0.05) and angiogenesis was significantly stimulated by transforming growth factor-beta(1) postoperative days 7 and 10 (p < 0.005). The mean cellular density was significantly increased in unperforated, transforming growth factor-beta(1)-treated membranes from days 3 to 10, and increased expression of actin with time was observed close to the wound margin. Transforming growth factor-beta(1) was thus shown to be a potent stimulator of angiogenesis and healing tissue formation in connective tissue repair, but this stimulation mainly occurred after closure of perforations. The increased cellular density in the absence of stimulated proliferation and increased actin expression in wound cells indicate that contraction may be an important mechanism of connective tissue repair in the perforated rat mesentery.

Journal Article↗