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At least 379 records · Page 21Linked to original sources
PubMed1987

Intrinsic connective tissue abnormalities in the heart muscle of cardiomyopathic Syrian hamsters.

Significant connective tissue abnormalities occurring in hearts of cardiomyopathic Syrian hamsters are reported. These abnormalities include a pronounced loss of the intrinsic connective tissue skeletal framework around foci of myocytolytic necrosis within the non-necrotic myocardium. These changes were demonstrated by a silver impregnation technique, and they were confirmed by scanning electron microscopy. Quantitation demonstrated more than a twofold increase in the area of ventricular wall affected by pathologic changes, when the connective tissue alterations were included with the myocardial necrosis. In addition, the authors also observed focal, thick "tethering" connective tissue fibers at the termini of necrotic lesions, seemingly connecting them to normal muscle. These connective tissue abnormalities may contribute to the progressive loss of ventricular function that occurs in this model of cardiomyopathy. They may permit greater wall thinning than would occur with focal necrosis alone, and they may increase focal mural stiffness in the tethered regions. Further investigation of the pathogenesis of these changes and their mechanical significance is indicated.

Animals↗
PubMed1999

Epidemiology of organic solvents and connective tissue disease.

Case reports suggest that solvents are associated with various connective tissue diseases (systemic sclerosis, scleroderma, undifferentiated connective tissue disease, systemic lupus erythematosis, and rheumatoid arthritis), particularly systemic sclerosis. A small number of epidemiological studies have shown statistically significant but weak associations between solvent exposure, systemic sclerosis, and undifferentiated connective tissue disease. However, the interpretation of these positive findings is tempered by a lack of replication, an inability to specify which solvents convey risk, and an absence of increasing risk with increasing exposure. Existing studies, on aggregate, do not show conclusively that solvents (either as a group of chemicals or individual chemicals) are causally associated with any connective tissue disease. Further investigations should be carried out to replicate the positive existing findings and to specify the solvents and circumstances of exposure that carry risk.

Connective Tissue Diseases↗
PubMed2000

Meta-analyses of the relation between silicone breast implants and the risk of connective-tissue diseases.

BACKGROUND: The postulated relation between silicone breast implants and the risk of connective-tissue and autoimmune diseases has generated intense medical and legal interest during the past decade. The salience of the issue persists, despite the fact that a great deal of research has been conducted on this subject. To provide a stronger quantitative basis for addressing the postulated relation, we applied several techniques of meta-analysis that combine, compare, and summarize the results of existing relevant studies. METHODS: We searched data bases and reviewed citations in relevant articles to identify studies that met prestated inclusion criteria. Nine cohort studies, nine case-control studies, and two cross-sectional studies were included in our meta-analyses. We conducted meta-analyses of the results of these studies, both with and without adjustment for confounding factors, and a separate analysis restricted to studies of silicone-gel-filled breast implants. Finally, we estimated the annual number of new cases of connective-tissue disease that could be attributed to breast implants. RESULTS: There was no evidence that breast implants were associated with a significant increase in the summary adjusted relative risk of individual connective-tissue diseases (rheumatoid arthritis, 1.04 [95 percent confidence interval, 0.72 to 1.51]; systemic lupus erythematosus, 0.65 [95 percent confidence interval, 0.35 to 1.23]; scleroderma or systemic sclerosis, 1.01 [95 percent confidence interval, 0.59 to 1.73]; and Sjögren's syndrome, 1.42 [95 percent confidence interval, 0.65 to 3.11]); all definite connective-tissue diseases combined (0.80; 95 percent confidence interval, 0.62 to 1.04); or other autoimmune or rheumatic conditions (0.96; 95 percent confidence interval, 0.74 to 1.25). Nor was there evidence of significantly increased risk in the unadjusted analyses or in the analysis restricted to silicone-gel-filled implants. CONCLUSIONS: On the basis of our meta-analyses, there was no evidence of an association between breast implants in general, or silicone-gel-filled breast implants specifically, and any of the individual connective-tissue diseases, all definite connective-tissue diseases combined, or other autoimmune or rheumatic conditions. From a public health perspective, breast implants appear to have a minimal effect on the number of women in whom connective-tissue diseases develop, and the elimination of implants would not be likely to reduce the incidence of connective-tissue diseases.

Autoimmune Diseases↗
PubMed1977

Immunopathology of skeletal muscle. The value of direct immunofluorescence in the diagnosis of connective tissue disease.

Whitaker and Engel in 1972 first described immunoglobulin deposition in muscle biopsy specimens in connective tissue disorders. In order to confirm and extend their observations and in the hope of identifying features that may differentiate skeletal muscle involvement in connective tissue diseases from other neuromuscular diseases, a series of 80 muscle biopsy specimens were examined using direct immunofluorescence. Three distinctive direct immunofluorescence patterns consisting of vascular, sarcolemma-basement membrane, and fiber staining were identified in skeletal muscle biopsy specimens from 35 patients, 31 of whom had a connective tissue disease. A vascular staining pattern showing a granular deposition of immunoglobulin or complement was seen in 15 patients, all of whom had a connective tissue disease. Routine stains generally did not reveal vessel abnormalities. A sarcolemma-basement membrane staining pattern was demonstrated around the sarcoplasmic membrane in 29 cases. Twenty-six of these patients had a connective tissue disease. There was no correlation with inflammation, fiber necrosis, or degree of connective tissue replacement. Fibers staining for immunoglobulin or complement, seen in 14 cases, generally occurred in morphologically normal fibers. Thirteen of these patients had a connective tissue disease. Since the pathologic change in muscle in the collagen vascular diseases often consists of the nonspecific findings of focal fiber necrosis frequently without inflammatory infiltrates, direct immunofluorescence may be useful in the diagnosis and classification of muscle diseases in the collagen vascular disorders. Furthermore, the findings of immunoglobulin deposition either within vessels or within individual muscle fibers suggest that immunological mechanisms may be responsible for muscular abnormalities in the connective tissue diseases.

Basement Membrane↗
PubMed1987

Idiopathic retroperitoneal and mediastinal fibrosis mimicking connective tissue disease.

Combined retroperitoneal and mediastinal fibrosis is a rare manifestation of an idiopathic systemic sclerosing disease. This report describes a multisystem illness that clinically could best be described as polyserositis and progressive renal failure. Pathologically, it was characterized by diffuse infiltration of retroperitoneal and mediastinal tissues with plaquelike fibrofatty connective tissue encasing the kidneys, ureters, adrenal glands, and parietal pericardium. These features are diagnostic of a systemic sclerosing disease. It is important to recognize this unusual disorder to avoid confusion with other systemic connective tissue diseases such as systemic lupus erythematosus.

Aged↗
PubMed1999

Connective tissue in female urinary incontinence.

An effective closure of the female urethra in stress situations is dependent on an integrated action of various anatomical structures connected to the organ. The most important of these structures - from a functional aspect - are the suburethral vaginal wall, the pubourethral ligaments, the pubococcygeus muscles and the paraurethral connective tissues. In all these structures connective tissue is an essential ingredient. Hence, defects in the actual connective tissue - in particular the paraurethral connective tissue that connects the aforementioned structures to each other and to the urethra - will bring about an ineffective urethral closure. Female urinary incontinence may then be caused by defective connective tissue per se and/or by a disconnection of the aforementioned structures, whereby the urethra cannot be 'kinked' - that is, closed off in stress situations.

Collagen↗
PubMed1988

Isolation of noncollagenous proteins from gingival connective tissue.

Noncollagenous proteins form an integral part of gingiva and other connective tissues. We have performed studies aimed at purification and partial characterization of the gingival noncollagenous proteins. Healthy gingival tissues from mongrel dogs were extracted in neutral buffers, acetic acid, and 6 mol/L urea. Immunoblots using anti-keratin antibodies and CNBr peptide patterns revealed that the majority of the proteins present in these extracts were keratins. To exclude keratins, gingival connective tissue was separated from the epithelium and then extracted. Acid extracts of the connective tissue contained very little protein, whereas urea extracts contained collagen and other noncollagenous proteins. The noncollagenous proteins present in the urea extract were partially purified by DEAE-cellulose chromatography and separated by affinity chromatography through a Sepharose 4B-type I collagen column. At least eight proteins, which ranged in molecular size from 15 to 75 kilodaltons, were obtained by this procedure. We conclude that keratins are major components of whole gingiva extracts and that epithelium must first be removed in order for connective tissue proteins to be obtained. The gingival connective tissue appears to contain several collagen-binding proteins, and these proteins may play an important role in the structure and function of the gingival matrix.

Animals↗
PubMed1993

Bronchiolitis in association with connective tissue disorders.

In general, lung involvement in connective tissue disorders has not been as well defined as has isolated interstitial lung disease; this applies particularly to bronchiolitis, which occurs infrequently. The low prevalence of bronchiolitis may reflect difficulties in making the diagnosis in mild to moderate disease; at present, most reported disease is severe. This is likely to account for the lack of therapeutic success in obliterative bronchiolitis and in many patients with follicular bronchiolitis. There is a need for earlier intervention if treatment is to be effective, and thus there is a need to refine the noninvasive diagnosis of bronchiolitis. This goal is unlikely to be achieved without the systematic noninvasive evaluation and surveillance of large groups of patients with connective tissue diseases. The role of the pulmonary function laboratory in identifying early bronchiolitis remains entirely uncertain; whether silent "small airways disease," defined physiologically, predicts the eventual development of bronchiolitis is unclear. The reversibility of this asymptomatic lesion with inhaled steroid therapy and the role of inhaled treatment in bronchiolitis, in general, have not been evaluated. More work needs to be done to determine the predictive value of CT appearances and BAL findings, to try to identify a subgroup of patients at greater risk of developing severe bronchiolitis. Further histocompatibility studies may serve as a basis for the selection of patients with an increased likelihood of developing airways disease. The role of open lung biopsy requires further clarification. Better noninvasive evaluation should reduce the need for this invasive procedure; in some patients, however, including those with concomitant interstitial lung disease, histologic assessment will remain an essential component of management. In recent years, in contrast to early reports, it has become apparent that organizing pneumonia has a better prognosis than fibrosing alveolitis in the connective tissue diseases; overall, stability or regression of disease, usually with corticosteroid therapy, was documented in 28 of 39 reported cases. In these patients, a tissue diagnosis serves to identify the need for aggressive therapeutic intervention. Finally, the compilation of larger clinical series would improve our understanding of severe bronchiolitis. This is likely to require multicenter collaboration, which often is impracticable; without this approach, however, the description of bronchiolitis will remain anecdotal.

Arthritis, Rheumatoid↗
PubMed2026

Soft Tissue Volume Augmentation at Single Implant Sites Applying Collagen Matrices or Connective Tissue Grafts: 10-Year Follow-Up of a Randomized Controlled Trial.

AIM: To compare up to 10 years clinical, profilometric and patient-reported outcomes of implant sites previously augmented using a volume-stable collagen matrix (VCMX) or connective tissue graft (SCTG) in the aesthetic zone. METHODS: The original non-inferiority randomized controlled trial (RCT) enrolled 20 patients who received soft tissue volume augmentation with VCMX or SCTG at single implant sites. Clinical assessments and standardized measurements were performed at baseline after crown insertion and at 6 months, 1, 3, 5, 7.5, and 10 years. The primary outcome was mucosal thickness. Secondary outcomes included marginal bone levels (MBL), probing depth (PD), bleeding on probing (BOP), plaque control record, Pink Aesthetic Score (PES), OHIP-14 and buccal profilometric changes. Group comparisons were performed using mixed-effects and generalized estimating equation (GEE) models, which account for within-patient correlations due to repeated measurements and allow inclusion of all available data without requiring imputation for missing observations. RESULTS: Of the 20 originally enrolled patients, 10 (5 in the SCTG group and 5 in the VCMX group) were available for re-examination at 10 years. The adjusted between-group difference in mucosal thickness was -0.02 mm (95% CI -0.99 to 0.96). As the lower bound of the confidence interval remained above the prespecified non-inferiority margin of -1 mm, non-inferiority of VCMX was shown. Buccal contour changes were comparable during the early follow-up, while a trend toward a greater long-term contour decrease was observed in group VCMX (-0.31 mm [95% CI, -0.65 to 0.03]; p = 0.07). Mean PES values were 10.6 in the SCTG group and 9.6 in the VCMX group, with no significant between-group differences (p = 0.45). Both groups revealed high levels of oral health-related quality of life, with low median OHIP-14 scores (SCTG, 0.0; VCMX, 1.0; p = 0.26). CONCLUSION: These preliminary long-term findings showed no clinically relevant differences between SCTG and VCMX in terms of clinical, profilometric and patient-reported outcomes. While SCTG remains the reference standard, VCMX represents a less invasive alternative but with a slight tendency toward greater long-term contour reduction. CLINICAL SIGNIFICANCE: Volume-stable collagen matrices serve as a viable alternative to autogenous connective tissue grafts for peri-implant soft tissue volume augmentation, particularly in patients seeking a reduced morbidity, without compromising long-term clinical or aesthetic outcomes. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00017484.

Humans↗
PubMed1980

Short and longterm experience with plasmapheresis in connective tissue diseases.

Plasmapheresis has been performed in eleven cases with connective tissue diseases, three with systemic lupus erythematosus, three with mixed connective tissue disease and five with rheumatoid arthritis. Plasmapheresis was in all cases instituted as an additional therapy during disease activity which was not under control with conventional modes of therapy. The best results were obtained in systemic lupus erythematosus and rheumatoid arthritis complicated with vasculitis. In mixed connective tissue disease with severe Raynaud's phenomenon, no striking and lasting results were obtained. Plasmapheresis seems to be a valuable adjunct in the management of acute exacerbation of connective tissue disease, especially when it is associated with drugs which can block antibody rebound.

Adrenal Cortex Hormones↗
PubMed1996

A critical assessment of the relationship between silicone breast implants and connective tissue diseases.

Concerns regarding the possible role of breast implants (particularly silicone breast implants) in the development of connective tissue diseases were raised by case reports of connective tissue diseases in women with breast implants. Case reports, however, are not appropriate for causation assessment. Within the past few years, epidemiologic studies have begun to appear. Based on a comprehensive literature search, 15 epidemiologic studies on breast implants and connective tissue diseases, which satisfied certain basic epidemiologic requirements, were included in the critical assessment. These studies utilized either the case-control or the cohort study design. Although each individual study was relatively small, and the statistical power to detect a modest risk increase in specific categories of connective tissue diseases was limited, the results of these studies, however, were strikingly consistent, particularly those reported in case-control studies. To increase statistical power and to take the consistency of results into consideration, meta-analyses were used to summarize results from individual studies quantitatively. Based on data from case-control studies, meta-analyses of rheumatoid arthritis, systemic sclerosis (scleroderma), and systemic lupus erythematosus were performed. These case-control studies represented a combined database of approximately 4000 cases of connective tissue diseases, and the power was sufficient to detect a relatively small increase in risk. Based on the meta-analyses, the relative risks (95% confidence intervals) were 0.85 (0.48-1.51) for rheumatoid arthritis, 0.82 (0. 50-1.35) for systemic sclerosis, and 0.33 (0.06-2.03) for systemic lupus erythematosus, indicating that there was no increased risk of connective tissue diseases associated with breast implants. The findings derived from the meta-analyses of case-control studies were supported by results from cohort or prospective studies. It was concluded that epidemiologic data did not provide any evidence for a causal relationship between silicone breast implants and connective tissue diseases.

Arthritis, Rheumatoid↗
PubMed1994

Cardiac tamponade and pericardial disorders in connective tissue diseases: case report and literature review.

Pericardial disorders occurring in connective tissue diseases are not uncommon and may present as acute or chronic pericarditis with or without an effusion. In many instances, a diagnosis of pericardial involvement is not found until autopsy. Echocardiography and other currently employed radiographic techniques have enhanced the ability to make a diagnosis. Approximate frequencies of common connective tissue disorders with pericardial involvement include scleroderma (59%), systemic lupus erythematosus (44%), mixed connective tissue disease (30%), rheumatoid arthritis (24%), and polymyositis/dermatomyositis (11%). Cardiac tamponade or constriction is rare. This article describes a patient with clinical features consistent with mixed connective tissue disease that presented with a pericardial effusion and cardiac tamponade. In addition, a review of pericardial involvement in connective tissue diseases and the occurrence of cardiac tamponade or constriction is included.

Adult↗
PubMed2004

Flexibility of type I collagen and mechanical property of connective tissue.

The hierarchical organization of the connective tissue, more specifically, the musculoskeletal soft tissue, has been extensively studied. With advancements in experimental methodology, investigation of the structure-function relationship has provided more insight into how the mechanical integrity of the tissue is created. Such information is essential in the linking the macroscopic loading environment of the tissue to the microscopic level of the tissue to be experienced by the cell. The flexibility and elastic modulus of gross connective tissue, the fascicle, the fiber and then the collagen molecule are compared based on the data available in the literature.

Adaptation, Physiological↗
PubMed1975

The composition of connective tissue macromolecules from bovine respiratory system.

Connective tissue macromolecules, glycosaminoglycans, glycoproteins, collagen, and elastin were isolated from different parts of the respiratory system and characterized. The materials included bronchiolar tissue, gas-exchange tissue, lung pleura, and tracheal mucosa. The similarity of the macromolecular composition of lung pleura and tracheal mucosa suggests a common cellular component in these structures. The high concentration of GAG and collagen in bronchiolar tissue is consistent with the cartilagenous nature of this tissue. Particularly interesting is the high content of heparin in all pulmonary structures, a relatively greater content of hyaluronic acid in gas-exchange tissue, and a high content of heparan sulfate and dermatan sulfate in vascular tissues. Elastin also occurs as a major fibrous structure. Although the biologic role of these connective tissue macromolecules has not been established, certain functional relationships are inferred.

Animals↗
PubMed1977

Ultrastructure of dermal connective tissue in fibrodysplasia ossificians progressiva.

The ultrastructure of dermal connective tissue in two patients suffering from fibrodysplasia ossificans progressiva (syn myositis o.p.) was studied. The disorder starts with soft tissue swelling which subsequently ossify. The connective tissue of various organs may be affected. No defects in calcium metabolism have been discovered. It was intended to study the primary event which initiates the ossification. The present ultrastructural study demonstrates an accumulation of proteoglycan microfibrils as well as glycoprotein material in dermal connective tissue. Both substances are prerequisites of calcification resulting from the binding of calcium and phosphorus ions. A subsequent release of proteolytic enzymes in the tissues may be set free the bound iones and, thus, initiate mineralization.

Calcium↗
PubMed1976

[Study of antibodies to heterologous connective tissue, isolated from sera of patients with rheumatism].

Antibodies against connective tissue elements of various bovine organs were isolated from the sera of rheumatic fever patients with the aid of immunosorbents (bovine connective tissue extract and erythrocyte stroma). The antibody preparations obtained were not identical and contained antibodies against different antigens of bovine connective tissue. The antibody preparations failed to react with human connective tissue components.

Antibodies↗
PubMed1996

A novel hypothesis to explain the hemorrhagic and connective tissue manifestations of Ebola virus infection.

The hemorrhagic and connective tissue complications of infection with Ebola virus are poorly understood. While searching for homologies and motifs of the aortic aneurysm-associated autoantigenic protein 40 kDa (AAAP-40), we have noted some short sequences (possibly shared epitopes) that occur in the envelope glycoprotein (40 kDa) of the Ebola virus. As a first step toward determining whether molecular mimicry of human matrix proteins by the Ebola virus protein might explain some of the severe connective tissue manifestations of infection, we have tested whether immunoglobulin (IgG) purified from the sera of patients with abdominal aortic aneurysm (AAA) are immunoreactive with the 40-kDa protein of the Ebola virus. Immunoblots of soluble Ebola proteins (strain Mayinga/Zaire) were probed with IgG's purified from the sera of eight patients with AAA and two healthy young control volunteers. The proteins were also probed with IgG extracted from the walls of two surgical aneurysm specimens. Serum IgG from eight consecutively studied AAA patients was immunoreactive with an Ebola virus protein of 40 kDa, consistent with the envelope glycoprotein. IgG's extracted from the walls of two AAAs were also reactive. The control sera were not reactive. In addition to the Ebola sequences in AAAP-40, an Ebola sequence also occurs in the microfibril-associated glycoprotein-4 (MAGP-4), which is distributed ubiquitously throughout connective tissue with elastin. We hypothesize that the catastrophic hemorrhagic and connective tissue complications of Ebola virus infection may be the result of these shared epitopes.

Aged↗