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 541 records · Page 30Linked to original sources
PubMed1989

Comparative studies on the stereo architecture of the connective tissue papillae in some mammalian tongues.

The epithelial cell layer was removed from the underlying connective tissue papillae by the method of long term hydrochloric acid treatment and the connective tissue surface was observed by scanning electron microscopy. Tongues of insectivora (Suncus murinus), rodentia (mouse, rat, guinea pig), carnivores (dog, cat) and primates (man) were studied. Each animal species had proper architecture of connective tissue papillae as to four types of lingual papillae. There was a tendency for the stereo structure of connective tissue papillae of these lingual papillae to become more complicated from insectivora to primates.

Animals↗
PubMed1987

Circulating hyaluronate. A potential marker of altered metabolism of the connective tissue in uremia.

Hyaluronate, a glycosaminoglycan of connective tissue matrix, was measured in serum by radioassay in patients with renal insufficiency (n = 22) and with end-stage renal failure (n = 40). The serum hyaluronate levels were significantly increased in both groups compared with the levels measured in age- and sex-matched healthy controls. Significant correlations were found between serum hyaluronate and degree of impaired renal function. None of the patients had laboratory signs indicating affection of the liver, the major elimination route for circulating hyaluronate. No significant alteration of hyaluronate levels was seen during hemodialysis. Renal transplants, previously on dialysis treatment, had normal serum hyaluronate values. Data obtained indicate either an essential role of the kidneys for the elimination of circulating hyaluronate or an increased outflow of hyaluronate to the circulation in uremia or a combination of these two possibilities. The altered metabolism of hyaluronate in uremia was not only related to the azothemic state but also to the age of the patients. The mechanism may be qualitively similar to that underlying the age-dependent increase of serum hyaluronate seen in health. The hypothesis that elevated serum hyaluronate in uremia may reflect an accelerated ageing of the connective tissue is highly speculative, but has some support by the finding that cardiovascular and other clinical symptoms were linked to particularly high serum levels of hyaluronate.

Adult↗
PubMed1988

Implications for connective tissue and bone alterations resulting from resistance exercise training.

Few studies have addressed the effects of resistance training on connective tissue. Inferences from studies investigating the effects of endurance training or "loaded" exercise training can be made. The available data suggest that 1) physical activity can increase connective tissue strength and mass, 2) activation of the antigravity muscles must be accomplished to adequately stimulate connective tissue, and 3) the volume, intensity, and load-bearing nature of the exercise training are important factors in causing connective tissue adaptations. Based on the above factors, a speculative model of training for increased maximum strength of connective tissue has been developed.

Adaptation, Physiological↗
PubMedDate not supplied

Denaturing HPLC-identified novel FBN1 mutations, polymorphisms, and sequence variants in Marfan syndrome and related connective tissue disorders.

Marfan syndrome (MFS), a common connective tissue disorder, is caused by fibrillin-1 (FBN1) mutations that are scattered throughout the gene and are largely unique to individual families. Mutation detection in this large gene of 65 exons is a considerable technical challenge. To develop an efficient method capable of identifying all possible mutations in this gene, we have explored the use of a novel denaturing high-performance liquid chromatography (DHPLC) system. This technique compares two or more chromosomes as a mixture of denatured and reannealed PCR amplicons. Under partially denaturing conditions, heteroduplexes can be separated from homoduplexes. A panel of 94 DNA samples from individuals with MFS or related connective tissue disorders was screened exon-by-exon by this method. A total of 66 unique heteroduplex profiles was identified. Sequencing of the amplicons detected 37 novel and two previously reported mutations, as well as 15 novel and 10 known polymorphisms or unique sequence variants that are probably of no clinical significance. Of the 34 mutations found in definitive MFS cases, 16 were identified in the 21 samples that had not been screened before (76% detection rate) and 17/40 (43%) were in samples previously screened by other mutation detection methods. In 32 individuals with MFS-related phenotypes, five FBN1 mutations were identified (16%). Our results demonstrate the power of the DHPLC method to detect FBN1 mutations. It should be applicable for mutation screening in any gene in a large population.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Cardiac conduction disturbances in mixed connective tissue disease.

BACKGROUND: Myocardial involvement occurs in about 20% of patients with mixed connective tissue disease. The purpose of this study was to determine the prevalence of conduction disturbances, their association with other manifestations of the disease. OBJECTIVE: Determine the prevalence of cardiac conduction disturbances in patients with mixed connective tissue disease attended in an institute in Mexico City and their relation with other manifestations of the disease. METHODS: One hundred thirteen patients admitted to the Institute with a diagnosis of mixed connective tissue disease were divided into those with conduction disturbances (n = 23) and those without (n = 90). Over a mean follow-up of 10.2 +/- 7.8 years, clinical course, treatment, duration of the disease, types of conduction disturbances and systemic alterations were examined. RESULTS: There was an overwhelming predominance of women in both groups. Conduction disturbances occurred in about 20% of the patients with mixed connective tissue disease and that was not possible to find significant differences in the outcome of them. As could be expected a significant difference between the two groups was QRS axis, related to anterior hemiblock, the most common conduction alteration observed. During the follow-up one patient death in-group A, but none in group B. CONCLUSION: Conduction disturbances were present in 20%; in agree with other authors in the literature. However, did not participate in the outcome of the disease.

Adult↗
PubMed1978

Isolation and characterization of epithelial and connective tissue cells from rat palate.

Epithelial and connective tissue cells were isolated from rat palate by sequential enzymatic digestion. Differences between the two populations were noted with respect to proline uptake and incorporation, % collagen synthesized, effects of parathyroid hormone and metabolism of D-valine. From these studies it can be concluded that the cell populations are viable and distinct with respect to the biochemical parameters examined.

Animals↗
PubMed1985

Localization of fibronectin in gingival connective tissue of the beagle dog. Immunofluorescent light microscopic findings.

Affinity purified antibodies to plasma fibronectin were used to localize fibronectin in the connective tissues of inflamed and noninflamed beagle gingiva. In noninfiltrated gingival connective tissue, fibronectin was demonstrated in the basement membrane beneath gingival epithelium and around blood vessels as a uniform and intensely stained band about 3 to 10 micron thick. Fibronectin was also distributed throughout the connective tissue in association with collagen fibrils as a more diffuse, less intensely stained pattern. The inflamed gingiva included in this study was characterized by proliferation of epithelial pegs, heavy infiltration of plasma cells and loss of collagen within the subepithelial connective tissue. In these sites, fibronectin was present as an intensely stained band around blood vessels and at the crest of connective tissue papillae nearest the sulcular space. The fibronectin in the basement membrane beneath the epithelium appeared diminished and less uniformly distributed. A delicate network of fibronectin was present around plasma cells and the remaining collagen fibers.

Animals↗
PubMed2003

Evaluation of human recession defects treated with coronally advanced flaps and either enamel matrix derivative or connective tissue. Part 1: Comparison of clinical parameters.

BACKGROUND: Recession defects around teeth have been treated with a variety of surgical techniques. Most of the literature suggests that the subepithelial connective tissue graft has the highest percentage of mean root coverage with the least variability. Previous studies have demonstrated that enamel matrix derivative (EMD) has the ability to improve clinical parameters. The purpose of this study was to compare the clinical efficacy of enamel matrix derivative placed under a coronally advanced flap to subepithelial connective tissue placed under a coronally advanced flap in patients with recession type defects. METHODS: Twenty patients with incisors or premolars presenting with a facial recession of > or = 4 mm in contralateral quadrants of the same jaw were treated; 17 patients completed the study. One tooth in each patient was randomized to receive either a coronally advanced flap with a subepithelial connective tissue graft (control) or a coronally advanced flap with EMD (test). Clinical parameters measured at baseline and at 6, 9, and 12 months included amount of recession; width at the coronal extent of the gingival defect; width of keratinized tissue; probing depth; clinical attachment level; inflammation score; plaque score; plaque index; alveolar bone level; tissue texture and color; and patient perception of pain, bleeding, swelling, and sensitivity. RESULTS: Results for both the test and control groups were similar for all measured clinical parameters with the exception of early healing, self-reported discomfort, and the amount of keratinized tissue obtained. The coronally advanced flap with EMD was superior to the subepithelial connective tissue graft with regard to early healing and patient-reported discomfort, whereas the subepithelial connective tissue graft demonstrated greater amount of keratinized tissue during the 12-month evaluation period. However, both the test and control showed a significant increase in the amount of keratinized tissue at 9 and 12 months compared to baseline. No significant difference in the amount of root coverage was found between the test and control groups (n = 19; P = 0.82). On average, a gain of 4.5 mm (range 4 to 8 mm) tissue covering the previously exposed root surfaces was achieved with both treatment groups. The average percentages of root coverage for control and test groups were 93.8% and 95.1%, respectively. One hundred percent root coverage was obtained 89.5% of the time with the coronally advanced flap with EMD and 79% of the time with the subepithelial connective tissue graft. CONCLUSION: Based on the results of this investigation, the addition of EMD to the coronally advanced flap resulted in root coverage similar to the subepithelial connective tissue graft but without the morbidity and potential clinical difficulties associated with the donor site surgery.

Adult↗
PubMed2004

Fixed prosthetics with a connective tissue and alloplastic bone graft ridge augmentation: a case report.

Augmentation of the partially edentulous ridge can significantly improve the final prosthodontic rehabilitation. For enhancing soft tissue contours in the anterior region, the subepithelial connective tissue graft is the treatment of choice. The combination of connective tissue grafts with alloplastic bone graft material can optimize the ridge augmentation and reduce post extraction defects. The aim of this clinical report is to describe the use of subepithelial connective tissue in conjunction with an alloplastic bone graft for augmentation of a maxillary anterior ridge prior to prosthetic rehabilitation.

Adult↗
PubMedDate not supplied

Interaction of human liver connective tissue cells, skin fibroblasts and smooth muscle cells with collagen gels.

Interactions of liver connective tissue cells, skin fibroblasts and smooth muscle cells with collagen gels in vitro were studied and compared. Liver connective tissue cells showed the lowest rate of migration into the gel and the highest speed of gel contraction, reflecting their high adhesiveness to the substrate as compared to the other cell lines studied. The analysis of their ultrastructural morphology showed that liver connective tissue cells and smooth muscle cells developed cytoskeletal and cytoplasmic organelle polarities, in response to the contact with gel surface. This polarity was lost when cells were embedded in the gel. Skin fibroblasts did not show this characteristic, neither on top nor in the gel. Although liver connective tissue cells have been recognized as analogous to smooth muscle cells, they represent a defined cell population, present in fibrotic livers, with specific behavior and with particular relationship to the extracellular matrix.

Cell Line↗
PubMed1991

Pathologic fibrosis and matrix connective tissue in the subaortic myocardium of patients with hypertrophic cardiomyopathy.

To evaluate scar-type and matrix connective tissue and to assess their role in the diastolic dysfunction of hypertrophic cardiomyopathy, surgically resected subaortic myectomy specimens and several autopsy hearts from patients with hypertrophic cardiomyopathy were studied. Eighteen specimens were differentially stained by a newly developed method that precisely determines relative collagen content; these tissues were compared with postmortem hypertrophied and normal control subaortic specimens. Quantitation revealed a 72% higher level (36.5 vs. 22.1 micrograms collagen/mg protein) of stainable collagen in the hearts with hypertrophic cardiomyopathy than in hypertrophied control hearts. The endocardial plaque was quantitated morphometrically, and it constituted only 4.6 +/- 1.7% of the total increased collagen content in the cardiomyopathy specimens. For the matrix studies, the cardiomyopathy specimens were stained by a silver impregnation technique that identifies connective tissue elements not normally visible with routine histologic methods. There was a marked increase in content of all matrix components, both in areas of pathologic scarring and in "normal" zones. Whorls of matrix connective tissue were noted in regions of myocyte whorls, as well as independent of them. Thus, these studies revealed a striking increase of both scar-type and matrix connective tissue in hypertrophic cardiomyopathy. The extensive scarring and the pronounced interstitial and intercellular matrix connective tissue may contribute to the increased ventricular chamber stiffness and impaired relaxation in this disease.

Cardiomyopathy, Hypertrophic↗
PubMed1977

The villous stroma of the human placenta. I. The ultrastructure of fixed connective tissue cells.

In human placental villi the connective tissue is constructed by mesenchymal cells, small and large reticulum cells and fibroblasts. During early pregnancy mesenchymal cells dominate; starting with the third month of gestation the reticulum cells are in the majority within the terminal villi, the fibroblasts within the stem villi. Ultrastructurally intermediary types of cells can be differentiated. Together with reticular and collagenous fibres the reticulum cells form the basic architecture of the villous stroma during the first 2/3 of gestation: the "reticular type of stroma". This consists of a network of cells and fibres with fetal vessels fitted in between. The remaining interspaces form a fluid system of compartments in which Hofbauer cells are suspended. They are called stromal channels. During the last trimester these channels and the Hofbauer cells as well are progressively replaced either by voluminous masses of fibres ("fibrous type of stroma", mainly in the stem villi) or by sinusoidal enlargements of fetal capillaries ("sinusoidal type of stroma", mainly in the terminal villi).

Cell Differentiation↗
PubMed1978

Antibodies against microfibrils of developing connective tissue in patients with inflammatory conditions.

Sera from patients with chronic inflammatory disease were tested for the presence of connective tissue antibodies. Fetal human skin was used as a substrate in an indirect immunofluorescence assay. Histological staining for connective tissue fibres, antibodies to connective tissue components and immunoelectron microscopy were used to identify the antigenic structures. Some antigenic fibrils were associated with elastin. By immunoelectron microscopy antigenic extracellular microfibrillar structures were identified. Antibodies against these microfibrils were detected in higher titres only in chronic inflammation (14%). Our results suggest that antibodies against connective tissues microfibrils may occur in human sera.

Antibodies↗
PubMed1998

Characterization of human orbital fat and connective tissue.

This study was designed to evaluate the characteristics of human orbital fat and connective tissue. Two exenteration specimens were studied by light microscopy with special stains. Four distinct regions were identified on the basis of their connective tissue septa, which contained blood vessels and were composed of elastin and collagen types I, III, and IV. Transmission electron microscopy was performed on the opposite orbits. The fibroblasts and adipocytes appeared metabolically inactive and showed no regional differences. The fat was phase extracted from the connective tissue and subjected to biochemical analysis. No regional differences were found in the content of fatty acids and protein. The fatty acids included palmitic acid (22-24.6%), oleic acid (45-51.5%), and linoleic acid (15-18.6%). Despite demarcation of the orbital fat into distinct regions by the connective tissue septa, ultrastructural and biochemical analysis revealed no regional variations in the fat. The diagnostic and therapeutic implications of these findings are discussed.

Adipose Tissue↗
PubMed1989

Retinoid-mediated induction of the fat-storing phenotype in a liver connective tissue cell line (GRX).

The GRX cell line is derived from murine liver connective tissue cells. It has myofibroblastic characteristics and can be induced to display a phenotype analogous to fat-storing (Ito) cells. Retinol-mediated induction of the fat-storing phenotype was studied in vitro. Based on the incorporation of radiolabelled acetate into cell lipids, cholesterol synthesis increased and phospholipid synthesis was modified shortly after the beginning of the induction, indicating an activation of pre-existing metabolic pathways. Triacylglycerol synthesis was increased only after a delay of 4 d, indicating the de novo induction of enzymes necessary for triacylglycerol metabolism. Retinol incorporation and conversion into retinyl esters were also considerably increased by previous incubation with retinoids. Retinoid-induced changes in GRX cells provide a model for studying in vitro the interconversion of liver connective tissue cells between the myofibroblastic and fat-storing phenotypes. This interconversion is considered to be one of the major control points of normal homeostasis and of pathological modifications of liver connective tissue.

Acetates↗
PubMed1990

Gastrointestinal manifestations of mixed connective tissue disease.

We examined the gastrointestinal tract abnormalities in 61 patients with mixed connective tissue disease. The first 34 were part of a prospective longitudinal study that included manometric and radiographic evaluation of the esophagus. Heartburn (48%) and dysphagia (38%) were by far the most common gastrointestinal symptoms. Seventeen percent of patients undergoing manometry had distal esophageal aperistalsis, and 43% low-amplitude peristalsis (less than 30 mmHg). Studies in 10 patients before and after treatment suggested that esophageal dysfunction in mixed connective tissue disease may be responsive to corticosteroids. Upper esophageal sphincter hypotension was also common. One patient had marked upper esophageal sphincter hypotension and recurrent aspiration, which resolved with corticosteroid therapy. Findings on radiographic studies of the stomach and small bowel in 54 patients and barium enemas in 16 patients were reviewed. Our series included one case each of malabsorption, colonic and small bowel perforations due to vasculitis, chronic active hepatitis, and acute pancreatitis. In conclusion, any area of the gastrointestinal tract may be affected by mixed connective tissue disease, although the esophagus is the most common location. The gastrointestinal aspects of mixed connective tissue disease overlap with those of progressive systemic sclerosis, polymyositis, and systemic lupus erythematosus.

Adolescent↗
PubMed1990

Characterization of the tissue macrophage and the interstitial dendritic cell as distinct leukocytes normally resident in the connective tissue of rat heart.

Immunohistological studies with a mouse anti-rat macrophage mAb (BMAC-5) demonstrated the presence of numerous positive cells in the interstitial connective tissues of many organs. The pattern resembled that seen with anti-MHC class II antibodies, with the striking exception that BMAC-5+ cells were rare or absent in the portal triad, the islets of Langerhans, and the kidney. Double-labeling fluorescence studies were therefore performed in rat heart using the BMAC-5 mAb in combination with rabbit antisera to pure rat class II MHC antigens and pure rat leukocyte common (CD45) antigens. The tissue macrophages in heart were identified as BMAC-5+, MHC class II-negative, leukocyte common antigen-positive cells. They could be distinguished from the BMAC-5-, MHC class II-positive, leukocyte common antigen-positive interstitial dendritic cells. Moreover, 7 d after lethal irradiation, the class II-positive interstitial dendritic cells had completely disappeared from heart, whereas the BMAC-5+ macrophages were present in undiminished numbers. These studies strongly suggest that the interstitial dendritic cell and the tissue macrophage represent two distinct populations of leukocytes within the connective tissues of antigenically secluded organs such as the heart. They have potentially important implications for the physiology of the immune system, as well as for autoimmunity and transplantation.

Animals↗