Arrangement of the collagen and elastic fibers in the upper human duodenum

Os autores estudaram a disposicao das fibras elasticas e colagenas na porcao superior do duodeno. Estas fibras dispoe-se paralelamente as fibras musculares. Na submucosa, ambos os tipos de fibras formam uma rede pantografica com seus angulos de cruzamento aumentando em direcao oral-aboral. As fibras colagenas e elasticas apresentam uma orientacao polar entre as fibras musculares.

Connective-tissue macromolecules in Golgi chicken tendon organs and at their interface with muscle fibers and adjoining tendinous structures.

Tendon organs from leg and forearm muscles of white leghorn chickens were examined with a library of monoclonal antibodies to determine the composition of their connective-tissue framework and the types of connective-tissue macromolecules that occur at the sites where muscle fibers attach to the receptors. The capsules of the tendon organs were positive for connective-tissue macromolecules typical of basal lamina (collagen type IV, laminin, and heparin sulfate proteoglycan) and for tenascin, collagen types III and VI, and fibronectin. Connective-tissue bundles in the lumen of a receptor reacted primarily with antibodies against collagen type I and 4-chondroitin sulfate. The narrow partitions that divide each lumen into compartments stained for collagen type III. Toward its tendinous end, a receptor made few contacts with muscle fibers. Instead, the capsule and the collagenous bundles blended gradually with the intermuscular portions of tendons. At the muscular end, the connections were more complex. Muscle fibers that attached in series to tendon organs split to produce basal lamina-covered, finger-like extensions, which were separated from each other by fissures. Tongues of connective tissue containing tenascin, collagen types I and VI, and fibronectin extended into the fissures. Distally the tongues were continuous with the tenascin in the capsule and just internal to the capsule, fibronectin and basal lamina macromolecules in the capsule, and collagen type I in the collagenous bundles. The uninterrupted presence of these macromolecules around terminating muscle fibers and in the capsule and/or the intraluminal collagen bundles suggests that muscle fibers that attach in series at the muscular end exert a force during muscular contraction on the intraluminal collagen bundles and on the receptor capsule.

"Corpúsculos colagénicos" deciduales: estudio en casos humanos y experimentales / Crepusde collagenics desiduals: study in cases human and experimental

En el presente trabajo nos ocupamos de las características de los "Corpusculos Colagénicos", (CC) descritos por Hamperl en 1958, como "Inclusiones Colagénicas", en células deciduales humanas. El estudio de material decidual humano procedente de embarazos uteriores a término, nos permitió, en una primera fase, comprobar la existencia de los CC en estas células deciduales; estudios posteriores en colaboración con S. García y M. Pinto, nos llevaron a constatar la presencia de los CC en células deciduales humanas de diferentes formas de embarazos: uterinos a término, abortos de los primeros meses, ectópicos (decidua tubárica), molas hidatiformes. Pudimos comprobar lo indicado por Hamperl respecto a afinidades tintoriales y características morfológicas esenciales en el estudio de un abundante material: predominio de forma redondeada, de situación excéntrica y tamaño entre 5 y 14 micras. No había diferencia apreciable entre los CC de células deciduales de diferentes formas de embarazo. Análisis de material de microscopia electrónica, en colaboración con O. Castejon, permitió: a) constatar la naturaleza colagénica de los CC; b) corroborar lo establecido por Wessel y confirmado por Castejon, de que los CC corresponden a invaginaciones de la membrana celular y del instersticio hacia el interior de la célula decidual. En el microscopio de luz, pudimos observar imágenes correspondientes a este mecanismo de invaginación y pudimos, además, confirmar la existencia de un espesamiento fibrilar pericelular. Este espesamiento puede ser difuso o nodular

In vivo biocompatibility of collagen-poly(hydroxyethyl methacrylate) hydrogels.

Collagen-p(HEMA) hydrogels were subcutaneously implanted in rats for up to 6 month and the immediate short- and long-term tissue response to these implants was studied. Histopathological data indicated that the tissue reaction at the implant site progressed from an initial acute inflammatory response characterized by the presence of eosinophils and polymorphs to a chronic response marked by few macrophages, foreign body giant cells and fibroblasts. After one month a very thin fibrous capsule (approximately 11 microns thick) was observed around the implant. Even 6 month post-implantation, the capsule thickness was maintained at about 11-12 microns. No necrosis, calcification, tumorigenesis or infection was observed at the implant site up to 6 month. Fibrous capsule analysis showed that the collagen content and the capsule thickness were well within the threshold limits. The collagen-p(HEMA) hydrogels were found to be well-tolerated, non-toxic and highly biocompatible.

Distribution of factor XIIIa-containing cells and collagenous components in radicular cysts: histochemic and immunohistochemic studies.

The distribution of subunit A of Factor XIII (FXIIIa) and of collagenous components was investigated by the avidin-biotin-peroxidase complex (ABC) method for FXIIIa and by the Sirius red F3BA method, respectively, in 43 cases of radicular cysts. Besides the covering epithelial layer, the radicular cyst wall was composed of the following three layers: an inner granulomatous layer, an outer fibrous connective tissue layer, and an intermediate layer. In each layer, a positive reaction for FXIIIa was observed in certain connective tissue cells. These FXIIIa-containing cells were few in number in the inner layer where collagenous components were also sparse. In the slightly to moderately fibrous intermediate layer, these cells markedly increased in number and were dendritic or stellate in shape. In the outer densely fibrous connective tissue layer, they decreased slightly in number and were slender and spindle-shaped. The results obtained in the present study indicate the close relationship between the distribution of FXIIIa-containing cells and of collagenous components. Such a relationship suggests that these cells play an important role in the process of fibrosis occurring in the radicular cyst wall.

Hydrogen/fluorine retuning tomography. Applications to 1H image-guided volume-selective 19F spectroscopy and relaxometry of perfluorocarbon emulsions in tissue.

A hardware modification which permits the record of 19F images, spectra, and relaxation times with a 1H tomography bird-cager resonator is described. Changing the spectrometer frequency from 1H to 19F resonance and vice versa is possible without removing the object to be investigated. This hydrogen/fluorine retuning tomography (HYFY) technique permits studies of identical slices or volume elements with 1H as well as with 19F resonance. In particular, it is possible to localize volume elements on the basis of multislice proton images and then to investigate these volume elements with fluorine magnetic resonance by the aid of volume selection methods. For this purpose, pulse sequences for the localized and spectroscopically resolved determination of spin-lattice and transverse relaxation times have been developed. The applicability of the techniques has been demonstrated by the aid of phantom samples as well as with excised porcine organs which have been perfused with perfluorocarbon emulsions.

Globular hyaline masses in the stroma of ameloblastoma: histopathologic and histochemical study.

A microscopical study of 15 intraosseous ameloblastomas revealed the presence of globular hyaline masses in only one of them (6.6%). These masses were confined to the stroma of plexiform areas and especially in regions undergoing cystic degeneration. They were periodic acid-Schiff positive and showed an affinity for acid dyes such as phloxine, acid fuchsin, orange G and picric acid. Regarding their pathogenesis, they are probably formed from extravasation of plasma glycoproteins, condensing and taking up a spheroidal shape in the liquid micro-environment of stromal degeneration under the influence of capillary phenomena.

Analysis of ecdysteroids in Onchocerca gibsoni, O. volvulus and nodule tissues.

Free ecdysteroids were detected in Onchocerca gibsoni, in tissues constituting O. volvulus and O. gibsoni nodules and in unrelated bovine tissues. Ecdysone and 20-hydroxyecdysone were identified by HPLC-RIA and GC/MS(SIM). The concentration of free ecdysteroids in the nodule tissue immediately surrounding the parasites was at least an order of magnitude higher than that detected in the worms themselves, or in adjacent nodular tissues or other bovine tissues.

Human salivary gland glycoconjugates: a lectin histochemical study.

The glycoconjugate content of normal salivary glands has been extensively investigated in humans by biochemical means and in non-human mammals by histochemical methods. However, there have been few histochemical studies of human tissues. This paper describes the findings obtained in parotid, submandibular and minor salivary glands by applying a panel of 13 biotinylated lectins, directed against a range of N-linked, fucosylated and galactosylated sequences, using an avidin-peroxidase technique, with appropriate enzymatic and inhibitory sugar controls. The results were generally in accord with those observed in biochemical assays but the use of lectin histochemistry permitted the localization in situ of small amounts of oligosaccharide and, therefore, allowed the recognition of subtle tissue differences. This study expands the current knowledge on the glycoconjugate composition of salivary glands and their lectin histochemistry and serves as a baseline for further studies, particularly in the field of neoplasia.

Distribution of elastin and collagen in canine lung alveolar parenchyma.

We have quantified the fibrous collagen (predominantly type I) and elastin in four locations of perceived mechanical importance: one quasi-planar feature, the alveolar septum or wall (W), and three linear features, the junction (J) of three septa, the free edges (E) of septa, and the line along which two septa join at a distinct angle or bend (B). The frequencies of these four features on light micrographs and the areas of transections through collagen and elastin seen on electron micrographs were combined to give the volumes of collagen and elastin within each feature. We find that E and B have similar compositions and contain most (4/5) of the parenchymal elastin in their relatively heavy cables. The E and B are interconnected and similar in location and composition, and they may constitute a functional entity in which elastin provides tension over a range of lung volumes, opposing septal tensions. In J and W, elastin is typically sparse and fine. Calculations, however, suggest it contributes the dominant portion of septal tension at lower lung volumes. Elastin may be essential to stabilizing septal configuration. Collagen, on the other hand, is distributed relatively evenly throughout E, B, J, and W, consistent with the role of protecting all components against rupture.

Changes in the connective tissue of corpus and cervix uteri during ripening and labour in term pregnancy.

The composition of the connective tissue of human cervix and corpus uteri was studied in tissue specimens from seven nonpregnant women and 14 pregnant women, delivered at term by section, to examine spontaneous cervical ripening and labour-induced changes in both the uterine and the cervical connective tissue. The main finding in both the cervix and the corpus was a large (40-60%) decrease of the collagen concentration. The collagen extractability, obtained by pepsin digestion, was increased twofold, suggesting a change of the organization of the collagen fibrils. This reorganization process could also be demonstrated by a large increase of the collagenolytic activity demonstrated with an artificial DNP-peptide substrate. The concentrations of sulphated glycosaminoglycans was lower in pregnant women than in non-pregnant women. The results show that both the cervix and the corpus uteri contain substantial amounts of connective tissue components (collagen, sulphated glycosaminoglycans and hyaluronic acid) and that during ripening, reconstruction of the connective tissue components occurs in both sites. This indicates that the cervical state reflects that of the myometrium.

Simultaneous determination of the reducible and nonreducible cross-links of connective tissue. Analysis of mineralized and nonmineralized bone collagen.

Secondary amine cross-links occur in collagen and elastin from a number of tissue sources. Quantification of these cross-links by amino acid analysis is complicated by the problem of separating cross-links, which are often minor components, from the more common amino acids and also because relatively large amounts of a cross-link are required to determine a color factor. A specific radioactive labeling method has been developed and used to quantify cross-links in bone collagen. Primary amines such as lysine and hydroxylysine are first guanidinated with 3,5-dimethylpyrazole-1-carboxamidine nitrate (DMPC). Secondary amines, which are unreactive with DMPC, are then quantitatively cyanoethylated with [14C]acrylonitrile. This procedure can be used to detect any secondary amine cross-link, with higher sensitivity than ninhydrin analysis, in peptide form as well as in acid hydrolysates. It is applied here in conjunction with [3H]NaBH4 reduction to simultaneously quantify Schiff base cross-links and amounts of in vivo reduction of Schiff bases in mineralized versus nonmineralized bovine bone.

Immunohistochemical localization of chondroitin sulfate and dermatan sulfate proteoglycan in human gingival connective tissue.

This study investigated the immunohistochemical localization of chondroitin sulfate (chondroitin, 4-sulfate and 6-sulfate) and dermatan sulfate proteoglycan (PG) in human gingival connective tissue, using monoclonal antibodies. Dermatan sulfate was found to be widespread in connective tissue, with an especially strong response shown in collagen fiber bundles under the epithelial basement membrane. Chondroitin 4-sulfate occurred widely in connective tissue but showed only a weak response. Chondroitin 6-sulfate was located in peripheral blood vessels. Chondroitin was not detected in gingival connective tissue.

Factor XIIIa-containing cells and fibrosis in oral and maxillofacial lesions: an immunohistochemical study.

The distribution of subunit A of blood coagulation factor XIII (FXIIIa) was investigated by the avidin-biotin-peroxidase complex (ABC) method in various oral and maxillofacial tissues. These tissues were from normal tongue, gingiva, lip, and submandibular gland, and from Dilantin gingival hyperplasia (one case), pyogenic granuloma (three cases), peripheral fibroma (four cases), squamous cell carcinoma (seven cases), chronic sclerosing submandibular adenitis (two cases), and fibrous dysplasia of the mandibular bone (one case). The distribution of collagenous components was examined in the same tissues by means of the Sirius red F3BA method. By means of the ABC method, FXIIIa was detected in the cytoplasm of certain connective tissue cells in each of the tissues examined. These FXIIIa-containing cells were sparse in the normal tissues but evidently abundant in the fibrous connective tissue of inflammatory and neoplastic lesions. In the present study, the close relationship between the distribution of FXIIIa-containing cells and that of collagenous components is demonstrated. The role that FXIIIa-containing cells play in the process of fibrosis is discussed.

Induction of connective tissue by various alloplastic materials: an experimental study in rats.

The capacity of three alloplastic implant materials to induce connective tissue was tested on the backs of 19 rats. A standardized viscous sponge served as control material. The commercial implant materials studied were carbon fibre and polypropylene ligament prostheses and a sponge composite of polytetrafluorethylene polymer and graphite fibre. Quantitative biochemical analyses (DNA, RNA, hydroxyproline and hexosamines) were done at 3 and 10 d, and 3, 6 and 9 wk post-operatively. Histological studies were done at 3, 6 and 9 wk. During the follow-up all the materials, when implanted subcutaneously, showed some capacity to induce ingrowth of granulation tissue. However, according to both quantitative chemical analyses and histological studies, the inductive capacity was greatest in the control sponge and in the polypropylene ligament prosthesis. In contrast, chemical analyses showed that the amount of granulation tissue developing during the follow-up was least in the rats with carbon fibre ligament implants.

Microprobe analysis of element distribution in bovine extracellular matrices and muscle.

The concentrations of some essential elements, Na, K, P, S and Cl were determined by microprobe analysis in bovine extracellular matrices of cartilage, tendon and elastic tissue (ligamentum nuchae) and in muscle cells. The values for the different tissues were compared and related to the blood electrolyte concentrations. Among the connective tissues the highest Na and lowest Cl values were found for cartilage which bears a high negative charge. The lowest concentrations of these elements occurred in elastic tissue which is relatively non-polar. In the three extracellular matrices sodium levels exceeded potassium. In myofibers potassium was the major cation at 30 times the blood value and about 3 times the concentration of sodium. Chlorine values were around 0.4 that of blood. Sulfur and phosphorus are components of the tissue macromolecules. The negative charge on the extracellular matrices is a function of carboxyl and sulfate radicals. In the myofiber this property is largely attributable to carboxyl and phosphate groups. Differences in potassium-sodium distribution in cells and extracellular matrices are attributed partly to the microtrabecular lattice and to the ordered state of cell water. In general the element concentrations and selective distribution can be related to the chemical composition and organization of the tissue, the net immobile charge, the nature of the dispersion medium (water) and changes in its dielectric constant, and to the physico-chemical properties of the individual ions.

Connective tissue-associated proteins in crevicular fluid: potential markers for periodontal diseases.

Tests for periodontal disease that are able to detect both ongoing and future loss of clinical attachment would be valuable assets in determining the diagnosis and treatment of periodontal diseases. We hypothesized that connective tissue-associated proteins could be detected in crevicular fluid and would reflect the biochemical activity of the periodontium in health and disease. To test this hypothesis, crevicular fluid samples obtained from patients with various states of periodontal disease were analyzed for the presence of several connective tissue-associated proteins using a dot blot assay. Two such proteins, osteonectin and N-propeptide alpha I type I collagen, were detected in crevicular fluid samples of patients with periodontal disease. Furthermore, the amount of these proteins detected in crevicular fluid appeared to increase with increased probing depth at the sampled site. These studies indicate that measurements of connective tissue-associated proteins in crevicular fluid may prove to be a valuable tool for diagnosing periodontal diseases.

Collagen processing, crosslinking, and fibril bundle assembly in matrix produced by fibroblasts in long-term cultures supplemented with ascorbic acid.

Human foreskin fibroblasts were cultured for up to 6 weeks in medium supplemented with ascorbic acid. During this time, the cells produced an extensive new connective tissue matrix in which the accumulated collagen (mostly type I) amounted to about 0.25 mg/10(6) cells. The matrix was highly differentiated as shown by complete processing of procollagen to collagen alpha-chains and covalent crosslinking of the collagen. Alignment of collagen fibrils occurred as the fibrils were deposited between cells, and binding of adjacent fibrils to the cell surface appeared to hold the fibrils in register. Groups of aligned fibrils were subdivided into bundles by cell-surface folds. If beta-aminopropionitrile was added to the medium, collagen crosslinking was inhibited, but not collagen synthesis or fibril bundle organization. If ascorbic acid was omitted from the culture medium, the extensive new connective tissue matrix was not produced. Our results indicate that fibroblasts in long-term cultures supplemented with ascorbic acid produce a connective tissue matrix with many in vivo-like properties including supermolecular organization of collagen.

Coexpression of keratin and vimentin in salivary pleomorphic adenomas.

The coexpression of keratin and vimentin is described in 45 pleomorphic adenomas using an immunoperoxidase MAb method. Histopathologically, the outer layer of tubuloductal structures and peripheral tumor cells in solid masses, including modified or neoplastic myoepithelial cells, showed positive staining with monoclonal keratin antibody K8.12 and vimentin. This staining was found in the ratio of 10/26 (38.5%) in tubuloductal structures, 2/7 (28.6%) in peripheral tumor cells and 8/12 (66.7%) in modified myoepithelial cells. Concomitant staining of other keratin antibodies (PKK1, KL1) and vimentin did not exist. In addition, the ductal basal cells of normal salivary glands showed positive K8.12 labelling. The histogenesis of pleomorphic adenoma is discussed in relation to the differentiation of either ductal basal cells or ductal luminal cells from a single stem cell origin or the direct transformation of ductal basal cells to outer tumor cells and/or modified myoepithelial cells, both coexpressing K8.12 and vimentin.

Mast cell heterogeneity in the small intestine of normal, gnotobiotic and parasitized pigs.

A formalin fixative and a formalin-free fixative were used to study mast cells in the small intestine of conventional, gnotobiotic and parasitized pigs. Many more mast cells were identified after basic lead acetate fixation ('mucosal mast cells', MMC) than after routine formalin fixation ('connective tissue mast cells'). The MMC were preferentially localized in the lamina propria. There were no differences between conventional and gnotobiotic pigs. However, in parasitized animals, the number of mast cells was several times higher, mainly because there were more MMC. The heterogeneity of intestinal mast cells in the pig indicates that this might be an interesting model for functional studies on mast cell subsets.