RESUMEN
Tendons and ligaments are mainly composed of type I collagen fibers surrounded by a mesh of loose connective tissue. The whole tendon transmits forces from muscle to bone. However, it also shows viscoelastic behavior such as creep or stress relaxation. Tendons respond dynamically to physical activity. Release of neurotransmitters and growth factors, as well as cell communication between tenocytes by gap junctions, initiate a cascade of transcriptions and metabolic alterations leading to enhanced activity of synthetic and degrading enzymes to ensure optimal functional adaptation of extracellular tissue. Tendons and ligaments vary greatly in shape, length, and composition. Especially where they are subject to compression, they are fibrocartilaginous. Loss of vasculature may explain the high incidence of pathological alterations in these areas. The aging tendon is characterized by a reduced ability to adapt to force transmission. Inactivity markedly decreases collagen turnover soon leading to reduced stress resistance. Counteracting these phenomena requires a full understanding of the physiological processes during mechanical loading.
Asunto(s)
Envejecimiento/fisiología , Ligamentos/anatomía & histología , Ligamentos/fisiología , Mecanotransducción Celular/fisiología , Tendones/anatomía & histología , Tendones/fisiología , Animales , Elasticidad , Humanos , Estrés Mecánico , ViscosidadRESUMEN
The objective of this study was the evaluation of the relation between the N-acetyl-neuraminic acid-binding endogenous lectin sarcolectin and the cytokine macrophage migration inhibitory factor (MIF) during development of rheumatoid nodules (RN) in seropositive rheumatoid arthritis (RA). Sarcolectin was purified and biotinylated. The binding patterns of this probe were analyzed in RN from patients with RA (n = 23) and compared with the distribution of antibodies with specificity for MIF, fibrin, fibronectin. In early RN, all areas of the inflammatory tissue displayed presence of receptors for sarcolectin. Macrophages were especially positive. In mature rheumatoid nodules binding of sarcolectin was restricted to the periphery of necrotic areas, to endothelial cells and perivascular connective tissue of marginal zones. Distribution patterns of MIF were similar but not identical. The histological staining characteristics demonstrate sarcolectin-binding receptors in RN that are altered upon disease progression. The finding suggests that specific interactions between this endogenous lectin and MIF may be involved in the course of RA.
Asunto(s)
Artritis Reumatoide/metabolismo , Lectinas/metabolismo , Factores Inhibidores de la Migración de Macrófagos/metabolismo , Nódulo Reumatoide/metabolismo , Adulto , Anciano , Animales , Artritis Reumatoide/patología , Artritis Reumatoide/fisiopatología , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Conejos , Nódulo Reumatoide/patología , Nódulo Reumatoide/fisiopatología , OvinosRESUMEN
Experimental evidence suggests that carbohydrates and their corresponding receptors (endogenous lectins) decode biological information. Therefore, the expression of complex oligosaccharides--the potential ligand part of this recognition system--during chondrogenesis and osteogenesis was determined in the viscerocranium of fetal rats by mapping the staining patterns of exogenous lectins. Results were compared with the expression of bone- and/or cartilage-specific core proteins and the binding profiles of neoglycoconjugates. These synthetic tools make possible the localization of sugar-ligand-binding sites. The spatial and temporal distribution patterns of glycoconjugates were highly dynamic and demonstrated a clear correlation with characteristic morphological modifications. The glycobiological characterization of precartilage mesenchymal cells revealed distinct differences compared to prospective bone anlagen. Especially the binding of the exogenous lectin from Griffonia simplicifolia II, that selectively visualized prechondral aggregations, reveals that regulation of early chondral growth is at least phenomenologically correlated with a relatively atypical oligosaccharide composition terminating with N-acetylglucosamine.
Asunto(s)
Cartílago Articular/embriología , Desarrollo Embrionario y Fetal , Glicoconjugados/biosíntesis , Lectinas/biosíntesis , Osteogénesis , Lectinas de Plantas , Cráneo/embriología , Animales , Cartílago Articular/citología , Cartílago Articular/metabolismo , Femenino , Edad Gestacional , Glicoconjugados/análisis , Lectinas/análisis , Macrófagos/citología , Mesodermo/citología , Mesodermo/fisiología , Oligosacáridos/análisis , Oligosacáridos/biosíntesis , Embarazo , Ratas , Ratas Sprague-Dawley , Cráneo/citología , Cráneo/metabolismoRESUMEN
Advanced glycation endproducts (AGE) are supposed to increase endothelial expression of adhesion molecules like vascular cell adhesion molecule-1 (VCAM-1) by inducing an intracellular stress with subsequent activation of nuclear transcription factor NF-kappa-B. Quantitative analysis of VCAM-1-transcription has not been demonstrated concerning this topic. Thus, the aim of this study was to establish quantitative reverse transcription polymerase chain reaction (RT-PCR) assays using a spacer gene in order to measure the amounts of specific mRNA for VCAM-1 in human umbilical vein endothelial cells (HUVEC) which were stimulated with AGE-albumin (AGE-BSA). A recombinant RNA-standard was synthesized and used as internal RT-PCR standard. The amount of VCAM-1-mRNA in unstimulated HUVEC was found to be 2.2 +/- 2.7 copies per cell. After stimulation with AGE-BSA, mRNA-levels were elevated to 38.9 +/- 10.9 copies per cell. Positive controls (stimulated with lipopolysaccharide) revealed mRNA-levels of 78.7 +/- 27.5 copies per cell. We conclude that quantitative RT-PCR using the spacer gene technique is a valid and reliable method for the measurement of small amounts of specific
Asunto(s)
Productos Finales de Glicación Avanzada/química , Albúmina Sérica Bovina/química , Molécula 1 de Adhesión Celular Vascular/análisis , Células Cultivadas , Células Endoteliales/química , Endotelio Vascular/citología , Humanos , ARN Mensajero/análisis , Reproducibilidad de los Resultados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Molécula 1 de Adhesión Celular Vascular/genéticaRESUMEN
Only few detailed investigations have focused on the glycobiology of cranial development. The functional elements in most inductive and morphogenetic processes are not individual cells, but rather collectives of interacting populations and extracellular matrix components that give rise to specific tissues and organs. Experimental evidence strongly suggests that sugar chains not only confer morphological characteristics. Complex carbohydrate molecules and their corresponding receptors are involved in recognition processes decoding biological information during cranial morphogenesis. The distribution patterns of glycoconjugates are highly dynamic and show a clear correlation with characteristic structural modifications. However, due to the intricate interactions in vivo the definitive physiological impact of these observations has to be established in further studies. In this review, the spatial and temporal patterns of lectin-reactive epitopes and selected receptor types are presented and discussed with regard to their potential importance to physiological craniogenesis.
Asunto(s)
Cartílago/química , Cartílago/embriología , Glicoconjugados/análisis , Cráneo/química , Animales , Diferenciación Celular/fisiología , Histocitoquímica , Humanos , Lectinas/análisis , Cráneo/crecimiento & desarrolloRESUMEN
Advanced glycation endproducts (AGEs) possibly play a dominant role in the pathogenesis of macrovascular disease in diabetes. Recent studies could demonstrate that glycated albumin (AGE-BSA) was able to stimulate vascular cell adhesion molecule-1 (VCAM.1) on endothelial cells. The aim of this study was to find out if AGE-BSA was not only able to enhance the expression of vascular cell adhesion molecule-1, but also of intercellular adhesion molecule-1 (ICAM-1) and E-Selectin on human endothelial cells. Stimulation of endothelial cells with AGE-BSA for six hours predominantly increased the expression of VCAM-1, but ICAM-1 and E-Selectin were also upregulated as shown by immunoilluminometric assay (ILMA).
Asunto(s)
Productos Finales de Glicación Avanzada/farmacología , Molécula 1 de Adhesión Celular Vascular/efectos de los fármacos , Albúminas/administración & dosificación , Albúminas/farmacología , Relación Dosis-Respuesta a Droga , Selectina E/efectos de los fármacos , Selectina E/metabolismo , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Expresión Génica/efectos de los fármacos , Expresión Génica/genética , Productos Finales de Glicación Avanzada/administración & dosificación , Humanos , Inmunohistoquímica , Molécula 1 de Adhesión Intercelular/efectos de los fármacos , Molécula 1 de Adhesión Intercelular/genética , Mediciones Luminiscentes , Reacción en Cadena de la Polimerasa , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Molécula 1 de Adhesión Celular Vascular/genéticaRESUMEN
The aim of this study was to determine the influence of sustained marginal vitamin A deficiency on the morphology of glycoconjugate expression in the tracheobronchial epithelium of guinea pigs. The distribution of oligosaccharide chains was investigated by applying a panel of 24 lectins. Glycosaminoglycans were detected by histochemical techniques. Number as well as morphology of ciliated cells showed no significant alterations in hypovitaminosis A. In contrast, the quantity of goblet cells was constantly decreased. A considerable reduction of secretory granules was also observed in these cells. Cytomembranes of ciliated cells (especially in the area of ciliar extensions) showed constant alterations in the patterns of lectin binding in vitamin A-depleted guinea pigs. Our results demonstrate a significant augmentation of accessibility of fucosyl molecules in proximal domains of glycoconjugates of ciliary membranes, whereas the presence of mannose structures seemed unchanged. In distal bronchioli, terminal N-acetylgalactosamine molecules were expressed. During marginal vitamin A deficiency, ciliary cells were specially labelled by GSA I(B), indicating presentation of terminal galactose molecules in alpha-position. Additionally, the cytoplasm of epithelial cells demonstrated enhanced concentrations of polyantennary oligosaccharide core structures. Staining of epithelial cells by VVA was restricted to control specimens. Abundance of N-acetylglucosamine residues on the non-reducing terminus of oligosaccharides was significantly enhanced in the connective tissue of depleted animals as demonstrated by the binding patterns of GSA II. We suggest that altered oligosaccharide patterns may contribute to enhanced predisposition to tracheobronchial infection in marginal vitamin A deficiency.
Asunto(s)
Bronquios/metabolismo , Glicoconjugados/metabolismo , Tráquea/metabolismo , Deficiencia de Vitamina A/metabolismo , Animales , Epitelio/metabolismo , Cobayas , Inmunohistoquímica , Lectinas/metabolismo , Ratones , Ratas , Especificidad de la EspecieRESUMEN
Different cell culture and organ systems are used to evaluate the physiological responses of the airways to the effects of carcinogenic [e.g., benzo(a)pyrene] and anticarcinogenic (e.g., retinoids) compounds on cellular growth and differentiation. However, in contrast to in vivo conditions dissociated epithelial cells or tracheal ring cultures are covered with medium. Therefore, we developed an ex vivo perfusion model enabling evaluation of morphology and metabolism of different compounds under near-physiological conditions. The trachea was surrounded with culture medium and perfused with air by means of a small animal respirator. To test the viability of the system under various experimental conditions tracheal probes were incubated with either retinoids (retinol 10(-5) mol/l; retinyl palmitate 10(-5) mol/l) or benzo(a)pyrene (10(-7) mol/l) for up to 7 days. At the end of the incubation period metabolites in the trachea and in the medium were measured by means of high-performance liquid chromatography. Samples were examined by light microscopy, and by scanning and transmission electron microscopy for cell morphology. Glycoconjugate expression was assessed by lectin histochemistry. Specimens incubated in a retinoid-supplemented medium revealed no alterations in the distribution of cell types and characteristics of the epithelial layer compared with tracheal biopsies assessed immediately after removal from the animals. Glycoconjugate patterns especially remained intact. Histological changes after incubation with benzo(a)pyrene resembled in vivo morphology of vitamin A-deficient rats. An important advantage of this in vitro model compared with common cell or organ cultures is the preservation of the original phenotype and environment of the tracheobronchial surface. In addition, carcinogenic substances, such as benzo(a)pyrene, can easily be applied by airway or through the medium.
Asunto(s)
Tráquea/metabolismo , Xenobióticos/toxicidad , Animales , Benzopirenos/farmacología , Diterpenos , Lectinas/química , Lectinas/metabolismo , Microscopía Electrónica , Oligosacáridos/química , Técnicas de Cultivo de Órganos/instrumentación , Técnicas de Cultivo de Órganos/métodos , Unión Proteica , Ratas , Ratas Wistar , Ésteres de Retinilo , Vitamina A/análogos & derivados , Vitamina A/análisis , Vitamina A/metabolismo , Deficiencia de Vitamina ARESUMEN
Alterations in the expression of glycoconjugate structures during cartilage development in the chondrocranium, nasal skeleton, Meckel's cartilage, limb buds, vertebral bodies and ribs were investigated comparatively in 13 to 21-d-old rat embryos. The binding patterns of 24 biotinylated lectins were analysed in serial sections and compared with results obtained using histochemical methods. Proteoglycan distribution, assessed by conventional staining procedures, was not associated with lectin binding sites. During early fetal development, hyaluronate concentrations were enhanced in areas of prospective chondrogenesis. With few exceptions, the lectins showed a general increase in intensity of binding to mesenchymal structures. Con A (Canavalia ensiformis), DSL (Datura stramonium), and WGA (Triticum vulgare) displayed a ubiquitous distribution of binding sites. After incubation with LCA (Lens culinaris), PSA (Pisum sativum), STL (Solanum tuberosum), and VAA (Viscum album), characteristic differences in binding intensity between focal areas of developing mesenchyme were seen. DBA (Dolichus biflorus), ECL (Erythrina cristagalli), GSL I (Griffonia simplicifolia), LTA (Lotus tetragonobolus), SJA (Saphora japonica), UEA I (Ulex europaeus) and VVL (Vicia villosa) consistently failed to bind. During chondrogenesis a general reduction of lectin staining was detected. In early stages of development GSL II (Griffonia simplicifolia) was a specific marker of the prechondral blastema in the viscerocranium. PNA (Arachis hypogaea) selectively labelled the prevertebral blastema. In contrast, condensing mesenchyme of limb buds and viscerocranium was not stained. Using RCA (Ricinus communis), it was possible to distinguish chondroblasts from mature cells. All chondrocytes were stained by PSA, PHA-E, PHA-L (Phaseolus vulgaris E and L), and WGA, whereas Con A, LCA, and GSL II detected distinct differences between cartilage with different localisations. Cartilage matrix was constantly negative. Applying GSL II it was possible to distinguish specific segments of the perichondrium. From our results we conclude that especially high mannose oligosaccharides are amplified during development. Terminal sialic acid molecules, branched intralaminar glucose and/or mannose, respectively, internal galactose-(beta 1,4)-N-acetylglucosamine sequences as well as galactose-(beta 1,3)-N-acetylgalactosamine sequences in a preterminal position are diffusely distributed in mesenchymal tissue. In contrast, no evidence for the presence of terminal GlcNAc(beta 1,4)GlcNAc sequences and terminal alpha-fucosyl residues in (1,2) or (1,3)-linkage was obtained. Chondrogenesis appears to be correlated with a general reduction in the extent of expression of oligosaccharide structures. No proof of terminal N-acetylgalactosamine and alpha-galactose moieties was found, whereas our staining results document the expression of terminal beta-galactose structures in restricted areas of the developing mesenchyme.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Cartílago/embriología , Glicoconjugados/metabolismo , Mesodermo/metabolismo , Acetilglucosamina/análisis , Animales , Sitios de Unión , Cartílago/metabolismo , Tejido Conectivo/embriología , Tejido Conectivo/metabolismo , Matriz Extracelular/química , Histocitoquímica , Ácido Hialurónico/análisis , Inmunohistoquímica , Lectinas , Morfogénesis , Proteoglicanos/análisis , Ratas , Ratas Sprague-DawleyRESUMEN
The staining patterns of 24 biotinylated lectins were analyzed in serial sections of the mandible of 13- to 21-day-old rat embryos by means of the avidin-biotin-peroxidase method. A ubiquitous distribution of binding sites was demonstrated after incubation with Con A (Canavalia ensiformis), DSL (Datura stramonium; except bone matrix), and WGA (Triticum vulgare). ECL (Erythrina cristagalli), GSL I (Griffonia simplicifolia), SJA (Saphora japonica), VVL (Vicia villosa), DBA (Dolichus biflorus), UEA I (Ulex europeus), and LTA (Lotus tetragonobolus) were constantly negative. In early stages of development, GSL II (Griffonia simplicifolia II) was a selective marker of prechondral blastema. In contrast, PNA (Arachis hypogaea) did not stain condensing mesenchyme. During chondrogenesis of Meckels's cartilage a general decrease of lectin binding was observed. Mature cartilage matrix was constantly negative. Chondrocytes were marked by the lectins PSA (Pisum sativum), WGA, PHA-E, and PHA-L (Phaseolus vulgaris E and L). A strong GSL II binding was restricted to the mesial-superior region of the perichondrium. In later stages, several lectins revealed significant differences between preskeletal ("central") areas and the remaining ("peripheral") mesenchyme. A clear binding reaction was noted in central regions by applying LEA (Lycopersicon esculentum) and STL (Solanum tuberosum), while the peripheral tissue was only faintly stained. Developing bone was specifically marked by succinylated WGA (sWGA). The lectins LCA (Lens culinaris) and RCA (Ricinus communis) bound to fibers and extracellular matrix of the connective tissue. Jacalin (Artocarpus integrifolia) and SBA (Glycine max) binding sites were found in macrophages. Affinity of VAA (Viscum album) increased parallel with maturation of endothelial cells. Specific lectin-binding patterns revealed no correlation with the distribution of glycosaminoglycans. The results demonstrate a general reduction of oligosaccharide structures during development of Meckel's cartilage. From our observations we conclude that intralaminar glucose and/or mannose sequences as well as terminal sialic acid molecules are ubiquitously distributed, while terminal alpha-fucose was constantly negative. Lectin-binding patterns of macrophages may reflect the presence of specifically linked terminal galactose. Our findings indicate that oligosaccharides terminating in N-acetylglucosamine are bone-specific. The significance of the restricted staining of the perichondrium by GSL II remains to be elucidated.
Asunto(s)
Cartílago/embriología , Glicoconjugados/metabolismo , Animales , Proteínas Portadoras/metabolismo , Cartílago/citología , Cartílago/metabolismo , Femenino , Lectinas/metabolismo , Embarazo , Ratas , Ratas Sprague-DawleyRESUMEN
The distribution of endogenous lectins, visualized by labelled neoglycoproteins, and of defined oligosaccharide structures, reactive with plant lectins, during fetal development of the fingers was analyzed in sections of human 3- to 8-month-old fetal specimens. Chondrogenesis as well as ossification were correlated with characteristic modulations in the expression of both glycoligand-binding molecules and characteristic carbohydrate structures. Occurrence of xylose-specific receptors was judged to be an early sign of cartilage development. Similarly, alpha-mannosyl residues that had been attached to labelled carrier proteins were strongly bound by the extracellular matrix already during early stages of finger maturation. Staining intensity for heparin gradually increased during chondrogenesis, whereas affinity for mannose showed a stage-related decline. Binding of mannose-6-phosphate was confined to hypertrophied cartilage of primary ossification centers. Accessible binding sites for terminal N-acetylneuraminic acid and N-acetylgalactosamine moieties were detected only in osteoid. In addition to monitoring the sugar-binding capacity, presence and developmental regulation of distinct carbohydrate structures were also assessed. PSA and SBA enabled the demonstration of an abrupt loss of staining affinity in the zone of maturing hypertrophic cartilage. Succinylated WGA proved to be an apparently useful marker of evolving bone tissue. GSL-II binding was restricted to chondroclasts and osteoclasts. The findings of this investigation are consistent with the supposed role of glycoconjugate-lectin interactions in cartilage and bone development.
Asunto(s)
Desarrollo Óseo , Cartílago/metabolismo , Dedos/embriología , Glicoproteínas/metabolismo , Lectinas/análisis , Sitios de Unión , Cartílago/embriología , Femenino , Glicoconjugados/análisis , Glicoconjugados/metabolismo , Histocitoquímica , Humanos , Lectinas/metabolismo , EmbarazoRESUMEN
The distribution of complex carbohydrate structures during the embryonic development of the rat palate was analysed by examining lectin-binding patterns in serial paraffin and cryostat sections. With few exceptions, the binding patterns showed a general increase in lectin receptors in the more developed stages of palatogenesis. High mannose oligosaccharides were especially amplified during development. Terminal fucose molecules were not expressed. In contrast, terminal sialic acid molecules were ubiquitously distributed in epithelial and mesenchymal tissues. Non-sialylated terminal N-acetylglucosamine was specifically restricted to evolving bone matrix. Before palatal fusion, quantitative but not qualitative differences were detected between oral, nasal, and medial-edge epithelial surfaces. The only exception was LCA, which specifically marked epithelial cells at the tip of palatal shelves. A very selective affinity for Jacalin was demonstrated in the oral epithelium of the palate after day 16, suggesting the presence of sialylated terminal galactose-(beta-1,3)-N-acetylgalactosamine. PNA specifically marked the basal lamina of the oral side of palatal processes. The binding patterns of DBA, GSL IA, SBA, and VVA indicated that the epithelium of the tongue is characterized by terminal alpha- and beta-galactose residues, whereas palatine cells possess only molecules with beta-anomery. During palatogenesis, glycosaminoglycans patterns were significantly modified. Our data suggest that alteration of complex carbohydrate structures may play a central role in modulating cell-cell and cell-matrix interactions. The significance of these findings, however, remains to be elucidated.
Asunto(s)
Glicoconjugados/fisiología , Hueso Paladar/embriología , Hueso Paladar/crecimiento & desarrollo , Acetilglucosamina/análisis , Animales , Secuencia de Carbohidratos , Matriz Extracelular/fisiología , Femenino , Fucosa/análisis , Galactosa/análisis , Glucosa/análisis , Glicoconjugados/análisis , Inmunohistoquímica , Lectinas , Masculino , Manosa/análisis , Datos de Secuencia Molecular , Oligosacáridos/análisis , Hueso Paladar/química , Adhesión en Parafina , Embarazo , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
The correlation between arthroscopic observations and histologic changes in rheumatoid arthritis is still controversial. Synovial samples of 21 knee joints in rheumatoid arthritis patients were comparatively investigated by endoscopy and histology. Biopsies were scored by an endoscopist and subsequently dissected. Different histochemical and immunocytochemical staining techniques were used to define inflammatory activity. Arthroscopic and histological values were compared by rating scales and variance analysis. Our study indicates that synovial biopsy is of diagnostic value in rheumatoid arthritis. However, its usefulness depends on the histochemical methods used. The results revealed highly significant correlations of endoscopic features with the number of neutrophilic granulocytes, intravascular leukocytes, and peroxidase-positive macrophages. However, no relationship was found between the detection of lymphocytes or resident macrophages and inflammatory scores. The close correlation between endoscopic and histological findings suggests that arthroscopic evaluation allows a valuable classification of the inflammatory activity in rheumatoid synovitis.
Asunto(s)
Artritis Reumatoide/patología , Artroscopía , Articulación de la Rodilla/patología , Granulocitos/patología , Humanos , Hiperplasia/patología , Inmunohistoquímica , Linfocitos/patología , Macrófagos/patología , Membrana Sinovial/patologíaRESUMEN
Cells of rheumatoid synovial tissue were bred in dispersion culture. In order to investigate the influence of three different culture media on the maturation and vitality of synovio-macrophages, Ham F10 (+fetal calf serum) and RPMI 1640 (+pooled AB Rh+ human serum) were compared with the serum- and cytokin-free solution AIM V. Combining light microscopic, transmission electron, and scanning electron microscopic methods (backscatter-mode), the enzyme and antibody features of synoviocytes were detected. The ratio of macrophages were determined in the light microscope by marking with CD 14. The functional maturation was shown by the amboceptor test. This study demonstrates that RPMI 1640 (+AB Rh+ human serum) is favorable for cultivating human synoviomacrophages. Under serum-free conditions AIM V is especially appropriate.
Asunto(s)
Artritis Reumatoide/inmunología , Medios de Cultivo , Macrófagos/inmunología , Membrana Sinovial/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales , Formación de Anticuerpos/inmunología , Antígenos CD/análisis , Antígenos de Diferenciación Mielomonocítica/análisis , Supervivencia Celular/fisiología , Femenino , Humanos , Receptores de Lipopolisacáridos , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Peroxidasa/metabolismo , Fagocitosis/inmunologíaRESUMEN
The aim of the present study was to compare the collagenous fibre systems of the anterior (ACL) with the posterior cruciate ligament (PCL). 22 cruciate ligaments were examined by the combined use of light-, transmission- and scanning electron microscopy. Characteristic interligamental differences were established. ACL: more anchoring type VI collagen, thinner but more branched fibrils, complex collagen networks, much more elastic elements. PCL: more type IV collagen, many intrinsic vessels, thicker fibrils, parallel fibre arrangement. The results indicate that the ACL is exposed at the first line to rotational forces, the PCL probably more to tensional forces. The collagen fibre arrangement of the cruciate ligaments is to take into consideration by the surgeon.
Asunto(s)
Ligamento Cruzado Anterior/ultraestructura , Colágeno/ultraestructura , Tejido Elástico/ultraestructura , Ligamento Cruzado Posterior/ultraestructura , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Persona de Mediana EdadRESUMEN
We have recently shown that synoviocytes and extracellular matrices exhibit distinct patterns of carbohydrate expression. Their biological relevance is however not known. The purpose of the present study was to find out whether human synovial tissue would also show a specific receptor pattern for complex sugar molecules. Endogenous lectins were displayed by means of biotinylated neoglycoproteins and sulfated polysaccharides in paraffin-embedded material or cryosections. In addition to certain carbohydrate components that are known to be constituents of the carbohydrate part of cellular glycoconjugates, our panel included heparin and fucoidan, a sulfated fucose. Binding sites were shown using the avidin-peroxidase technique for light microscopy. The results were compared with immunohistochemical methods and enzyme histochemistry. Our study demonstrates that human synovial tissue contains a complex pattern of endogenous lectins depending on the different types of synovitis. The staining method we used in the investigation allows for precise localization of saccharide binding receptors and is therefore believed to be a reliable technique for further phenotypic characterization of synovial cells.
Asunto(s)
Lectinas/metabolismo , Membrana Sinovial/metabolismo , Anticuerpos Monoclonales , Artritis Reumatoide/metabolismo , Artritis Reumatoide/patología , Biopsia , Metabolismo de los Hidratos de Carbono , Histocitoquímica/métodos , Humanos , Osteoartritis/metabolismo , Osteoartritis/patología , Receptores de Superficie Celular/metabolismo , Valores de Referencia , Coloración y Etiquetado , Membrana Sinovial/patologíaRESUMEN
Light-microscopical lectin-binding studies were carried out in healthy and pathologically altered synovial tissue (osteoarthrosis, rheumatoid arthritis (RA)). Seven lectins were studied: Con A, DBA, PNA, RCA, SBA, UEA-I, and WGA. Con A and WGA mark all lining cells and the majority of subintimal synovial cells. RCA and SBA stain only a portion of lining cells, regardless of the basic pathology. The lectin PNA reacts only with RA and arthrotic material, and is thus suitable for the diagnosis of inflammatory changes in synovial tissue. UEA-1 is a consistent marker for capillary endothelium and large vessels.
Asunto(s)
Lectinas/metabolismo , Membrana Sinovial/metabolismo , Artritis Reumatoide/metabolismo , Artritis Reumatoide/patología , Biomarcadores , Humanos , Osteoartritis/metabolismo , Osteoartritis/patología , Membrana Sinovial/patologíaRESUMEN
The lectin binding sites of the synovium of patients with rheumatoid arthritis and osteoarthritis were investigated. It was shown that Ulex europaeus agglutinin is a constant marker of the vascular endothelium and is not induced during the course of inflammatory process in rheumatoid arthritis.
Asunto(s)
Endotelio Vascular/metabolismo , Lectinas/metabolismo , Lectinas de Plantas , Receptores de Superficie Celular , Receptores Mitogénicos/metabolismo , Membrana Sinovial/irrigación sanguínea , Artritis Reumatoide/patología , Biopsia , Humanos , Técnicas para Inmunoenzimas , Articulación de la Rodilla/patologíaRESUMEN
A 41-year-old woman with seronegative rheumatoid arthritis is presented. Three metatarsal heads showed a nearly selective destruction of the calcified zone of cartilage while other zones remained intact. The mechanisms underlying joint destruction are discussed.
Asunto(s)
Artritis Reumatoide/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Adulto , Artritis Reumatoide/patología , Calcinosis/patología , Cartílago Articular/diagnóstico por imagen , Cartílago Articular/patología , Femenino , Tejido de Granulación/diagnóstico por imagen , Tejido de Granulación/patología , Humanos , RadiografíaRESUMEN
Biopsy material of synovial tissue was taken from 36 patients (with arthrosis, rheumatoid arthritis, traumatic and unaffected joints). Cell and tissue cultures, as well as cells dissociated by enzymes, were investigated by light microscopy (LM), immunohistochemistry, and electron microscopy. Synovial A-cells were endowed with all morphological characteristics of phagocytic capacity but lacking the peroxidase reaction. In contrast to the monocytes, they were not immunostained by OKM-1 antibodies. The A-cells could be observed in subsequent in vitro growth for up to 2 weeks. In addition to B-cells, a third cell type was identified. This cell type had the morphological characteristics of a dendritic cell and was glass and plastic adherent. It can be referred to also as a stellate cell. We assume that these stellate cells represent modified synovial fibroblasts.