Bundles Of Elastic Fibers Research Articles

Histological observations of age-related changes in the epiglottis associated with decreased deglutition function in older adults.

Although the epiglottis plays a vital role in deglutition, histological studies of the epiglottis and surrounding ligaments associated with swallowing dysfunction are limited. Therefore, we performed histological observations to clarify age-related changes in the morphological characteristics of the epiglottis and surrounding structures. Tissue samples comprising the epiglottis and surrounding structures were collected from corpses that were both orally fed and tube-fed during their lifetimes. Following hematoxylin and eosin, Elastica Van Gieson, and immunohistochemical staining procedures, the chondrocytes, connective tissue, and glandular tissue were observed under the epiglottis epithelium, and intervening adipose tissue was observed in the surrounding area. Fatty degeneration of acinar cells was also observed in the glandular tissue, possibly because of aging. Bundles of elastic fibers were present around the vascular wall in the peri-epiglottic ligament, but some were reduced. Furthermore, large amounts of collagen fibers ran toward and through the cartilage, whereas the mesh-like elastic fibers stopped in front of the cartilage. Microfibrils considered to be oxytalan fibers, which are thinner and shorter than elastic fibers, were observed around the vascular wall and in the fiber bundles. Age-related changes included connective tissue fibrosis shown by the large amount of collagen fibers, atrophy of salivary glands, and an accompanying increase in adipose tissue. Regarding stretchability and elasticity, the elastic fibers may have an auxiliary function for laryngeal elevation during deglutition. This suggests that disuse atrophy of the laryngeal organs with or without oral intake might reduce the amount of elastic fiber in older adults.

THE HISTOTOPOGRAPHIC FEATURES OF FORMATION OF KELOID SCARS OF MAXILLOFACIAL LOCALIZATION

The aim: Study of the influence of local oxygen deficiency on the features of the formation of keloid scars of the head and neck. Materials and methods: The research material was 17 incisional biopsy specimens of keloid scars, which were the highest age categories of patients from 19 to 63 years. Results: It was revealed that at coloring according to Mallory's technique, sections of fibrinoid swelling of collagen fibers were noted near central homogeneous hyaline masses. The lateral areas of the dermis that adjacent to keloid scar tissue, at coloring by the Hart method, in our modification, were characterized by the separation of the hyalinosis zone from the undamaged dermis by coarse bundles of elastic fibers that are colored in dark purple. The undifferentiated dysplasia of the connective tissue has caused the replacement and obstruction of single vascular components, which has complicated the local oxygen deficiency of keloid-altered tissues. Conclusions: Thus, plasmaragia and the accumulation of protein deposits in the perivascular space determine the inhibition of local hemodynamics, which explains the decrease in oxygen transport to tissues. Decreased oxygenation and increased permeability of the vascular wall causes local hemocirculatory hypoxia.

The Distribution of Collagen and Elastic Fibres in the Lactating Bovine Mammary Gland

Abstract Collagen and elastic fibres are generally present in organs whose normal function requires great resistance and elasticity. The aim of this study was to localize the collagen and elastic fibres in the stroma of the bovine lactating mammary gland and to determine their role in the process of milk ejection. For this purpose, the histochemical staining for collagen and the immunohistochemical method for the detection of elastin were used. The accumulation of scattered collagen fibres was observed between and inside the lobules where they formed distinct septa. Between secretory alveoli, the collagen fibres were found to be concentrated into two incomplete layers surrounding the blood capillaries. Bundles of elastic fibres in high density were located in the interlobular spaces. A dense network of elastic fibres was located between adjacent alveoli. Elastic membranes were located beneath the secretory epithelium. The high concentration of the collagen and elastic fibres indicated, that both types of fibres play a significant role in the resistance during the secretory stage and in the recoil of the mammary gland after milk ejection.

Cricothyroid Articulation in Elderly Japanese With Special Reference to Morphology of the Synovial and Capsular Tissues

The present study aimed to clarify individual variations in the cricothyroid joint (CT joint). Using 30 specimens of the CT joint obtained from elderly donated cadavers, we examined the composite fibers of the capsular ligament as well as the morphology of the synovial tissue. The capsular ligament consistently contained abundant thick elastic fiber bundles on the anterior side of the joint (anterior band) and an elastic fiber-made mesh on the posterior side (posterior mesh). The synovial membrane, lined by synovial macrophages, was usually restricted to the recesses in the medial or inferior end of the joint cavity. Without the synovial lining, elastic fibers of the capsular ligament were subsequently detached, dispersed, and exposed to the joint cavity. We also observed a folded and thickened synovial membrane and a hypertrophic protrusion of the capsular ligament. In six specimens, the joint cavity was obliterated by debris of synovial folds and elastic fiber-rich tissues continuous with the usual capsular ligament. Notably, with the exception of two specimens, we did not find lymphocyte infiltration in the degenerative synovial tissue. We considered the CT joint degeneration to be a specific, silent form of osteoarthritis from the absence of lymphocyte infiltration. For high-pitched phonation, the elderly CT joint seemed to maintain its anterior gliding and rotation with the aid of elastic fiber-rich tissues compensating for the loss of congruity between the joint cartilage surfaces. Conversely, however, high-pitched phonation may accelerate obliteration of the joint.

Histology and immunohistochemistry of the developing juxta-oral organ in mice

The juxta-oral organ is a persistent bilateral organ in the mammalian bucca. It consists of epithelial parenchyma and surrounding mesenchymal sheath with connective tissue rich in nerve fibers and sensory receptors between them. The organ develops from the embryonic oral epithelium and is separated from the oral mucosa. The morphology of this organ is very different in mice compared to humans. Although several reports have described the histology of the juxta-oral organ in rodents, its developmental changes have rarely been reported. In the present study, histological development and ultrastructure of the juxta-oral organ, with special attention to its epithelial parenchyma and mesenchymal sheath, were investigated in mice during several developmental stages. Immunohistochemical staining for pan-cytokeratin (CK) on serial paraffin sections of the head allowed easier detection of this organ. The juxta-oral organ was innervated by the buccal nerve from an early stage of organogenesis at E13.5. The organ was located adjacent to the fascia of the masticatory muscles during all developmental stages examined. The parenchymal cells were immunohistochemically positive for p63 and CK14 in both newborn and adult mice, suggesting that these epithelial cells possess characteristics of the basal cells of the stratified epithelium. Furthermore, the parenchyma was ensheathed by layers of mesenchymal cells with perineurial characteristics as shown by immunohistochemical staining and electron microscopy. Unique sensory endings and bundles of elastic fibers were observed between the epithelial parenchyma and mesenchymal sheath.The present findings concerning the structure of mouse juxta-oral organ, especially that of epithelial parenchyma and mesenchymal sheath provide baseline knowledge for the further understanding of the unique morphological features, developmental changes and functional details of this organ.

Macroscopic and histological investigation of guanaco footpads (Lama guanicoe, Müller 1776).

The surface of guanaco footpads is characterized by hairless skin with up to 4-mm-thick stratum corneum that protects from abrasion. The horny layer is pliable and elastic, and ensures firm contact with irregular ground. It is padded with a particular structure of the subcutaneous layer, the digital cushion. The flat cushions of each of the two digits are of elongated ovate shape, each about 45-mm long, up to 20-mm wide, and 8-mm thick. The cushions are lined by a 1-2-mm-thick capsule that resembles a tunica albuginea. The capsule consists of coarse collagen fibers, with elastic fibers absent. The cushion capsule and dermis approach each other, and fuse along a line that runs parallel to the longitudinal axes of cushion and digit. Loose connective tissue rich in elastic fibers and acidic glycosaminoglycans separates dermis and cushion capsule lateral to the narrow interconnecting zone. The cushion capsule encloses cloudy yellowish, gelatinous material. Microscopy shows bundles of elastic fibers in abundant mucinous matrix. Tightly gathered elastic bundles adjoin the inner surface of the capsule. Rough cords of elastic fibers branch out from there and traverse to the opposite side. The cushion is pressed flat, and elastic fibers are stretched when bearing weight. With relief of load, elastic fibers contract and reset the cushion's shape. Contractile cells are absent. A resistant capsule and easily malleable mucinous contents establish the functioning as a gel pad. Mucinous connective tissue between elastic fiber bundles contains abundant basophilic matrix. Hyaluronan, chondroitin sulfate, and dermatan sulfate are main matrix constituents. Spindle-shaped or stellate fibroblasts contain vimentin, S100 protein, and neuron specific enolase. Moprhology, staining characteristics and synthesis activities of these cells meet the criteria to be classified as myxoid cells. The connective tissue in guanaco digital cushions represents myxoid tissue.

Architectural changes of the extracellular matrix in compensatory lung growth (540.2)

Compensatory growth of the remaining lung after murine pneumonectomy (PNX) involves the structural remodeling of the peripheral acini. Although the role of stem cells and local cellular proliferation is an area of active investigation, very little is known about the corresponding changes in the lung extracellular matrix (ECM). Post‐PNX adaptation of the elastin network, in particular, is essential for maintaining the mechanical and functional properties of the lung. Elastic fiber bundles concentrate particularly in the end bulbs of free septal alveolar edges shown in trans‐electron‐microscopic imaging and Verhoeff‐van‐Gieson staining. The elastic fibers form a continuous helical cable element, interconnecting alveolar entrance rings, spanning several levels of alveolar ducts. High‐resolution synchrotron radiation microscopy revealed this cord element running on the inside of alveolar ducts of infant murine lungs in the alveolar phase of lung development. The continuity of the elastic helix in adult c57bl/6 mice was visualized by scanning electron microscopy and by confocal microscopy of decellularized murine lung slices. Stereological estimates show an increased number of elastin‐containing septal edges during compensatory growth. The architectural changes in the murine ECM suggest active remodeling of the elastin network after PNX. The orientation of elastin in the septal tips of remodeling alveoli suggest the active participation of the elastin network in neoalveolarization. Consistent with these observations, the elastin cord element may be involved in the long‐range signaling essential for functional acinar remodeling.Grant Funding Source: NIH

Histological Characteristics of Altered Human Lingual Frenulum

Aim: The aim of this study was to describe the histological characteristics of altered human lingual frenulum. Materials and Methods: Between March and July, 2011, 50 children between 6 months and 4 years of age were assessed by a Speech Language Pathologist in a Public Health Care Service in Brotas – Sao Paulo, Brazil. The lingual frenulum evaluation protocol proposed by Marchesan (2010, 2012) was administered to the 50 children – 26 male and 24 female. Of the 50, 8 children had lingual frenulum alterations. The 8 children with lingual frenulum alteration underwent lingual frenectomy. The materials for analyses were taken from 7-micrometer-thick tissues sections. Staining was employed using haematoxylin paired with eosin (H&E), Masson’s trichrome and picrosirius red. Results: The assessment of the lingual frenulum indicated that 8 children had lingual frenulum alteration. Surgery was performed and the material collected was submitted to analyses. The histological analyses demonstrated that the lingual frenulum of children with ankyloglossia or with short frenulum had bundles of striated skeletal muscle fibers, high frequency of type I collagen in the deep layers and compact bundles of elastic fibers positioned near the epithelial lining. Bundles of muscle fibers were not observed in anterior frenulum and short frenulum with anterior fixation. Type I collagen and bundles of elastic fibers sparse and far from the epithelial lining were observed in those types of frenulum. Conclusion: The analysis of the histological sections demonstrated the characteristics of altered human lingual frenulum.

Ossification process involving the human thoracic ligamentum flavum: role of transcription factors

IntroductionOssification of the ligamentum flavum (OLF) of the spine is associated with serious neurologic compromise, but the pathomechanism of this process remains unclear. The objective of this study was to investigate the pathomechanism of the ossification process, including the roles of various transcriptional factors in the ossification of human thoracic ligamentum flavum.MethodsSections of the thoracic ligamentum flavum were obtained from 31 patients with OLF who underwent posterior thoracic decompression, and from six control patients free of OLF. Cultured ligamentum flavum cells (n = 6, each) were examined with real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis for Sry-type high-mobility group box 9 (Sox9), runt-related transcription factor 2 (Runx2), muscle segment homeobox 2 (Msx2), Osterix, distal-less homeobox 5 (Dlx5), and AP-1. The harvested sections were examined with hematoxylin-eosin, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, and immunohistochemistry for the transcriptional factors.ResultsCompared with the control, the OLF showed disorganization of the elastic fiber bundles and abundant hypertrophic chondrocytes in the ossification front. TUNEL-positive chondrocytes were found near the ossified plaques. The mRNA expression levels of Sox9, Runx2, Msx2, and AP-1 in cultured cells from the ligamentum flavum of OLF patients were significantly different from those of the control. OLF samples were strongly immunoreactive to Sox9, Runx2, and Msx2 at proliferating chondrocytes in the fibrocartilage area. Hypertrophic chondrocytes were positive for Runx2, Osterix, Dlx5, and AP-1.ConclusionsThe ossification process in OLF seems to involve chondrocyte differentiation under the unique expression of transcriptional factors. Accumulation of hypertrophic chondrocytes was evident around the calcified area at the ossification front, and we suggest that the differentiation of these cells seems to be concerned with the ossification process.

Failure processes in elastic fiber bundles

The fiber bundle model describes a collection of elastic fibers under load. the fibers fail successively and for each failure, the load distribution among the surviving fibers change. Even though very simple, the model captures the essentials of failure processes in a large number of materials and settings. We present here a review of fiber bundle model with different load redistribution mechanism from the point of view of statistics and statistical physics rather than materials science, with a focus on concepts such as criticality, universality and fluctuations. We discuss the fiber bundle model as a tool for understanding phenomena such as creep, and fatigue, how it is used to describe the behavior of fiber reinforced composites as well as modelling e.g. network failure, traffic jams and earthquake dynamics.

Presence of perivenular elastic fibers in nonalcoholic steatohepatitis Fibrosis Stage III.

Elastic fibers appear in extensive old fibrotic foci in general. We examined an association between hepatic fibrosis stage and the presence of perivenular elastic fibers in nonalcoholic steatohepatitis (NASH). A total of 48 liver needle biopsy specimens were used, taken from 48 cases with NASH. Fibrosis Stage (Brunt E, et al. Am. J. Gastroenterol. 1999) of the cases was as follows; six Fibrosis Stage I, twenty-two Fibrosis Stage II, and twenty Fibrosis Stage III. We examined Orcein stain sections in all of the liver needle biopsy specimens. In all twenty Fibrosis Stage III cases, perivenular elastic fiber bundles were observed. In contrast, perivenular elastic fibers were detected only in one of the six Fibrosis Stage I and two of the twenty-two Fibrosis Stage II cases. In liver needle biopsy specimens of NASH, detection of perivenular elastic fibers is useful in deciding Fibrosis Stage III.

Calcium pyrophosphate crystal deposition in the ligamentum flavum of degenerated lumbar spine: histopathological and immunohistological findings

We investigated the histological and immunohistochemical features of degenerative changes in the ligamentum flavum of the lumbar spine with calcium crystal deposition. We investigated degenerative changes in 270 ligamentum flavum specimens harvested from 198 patients who underwent decompressive surgeries for lumbar spinal canal stenosis. En bloc sections of the ligamentum flavum were examined histologically. We also examined immunoreactivity for transforming growth factor (TGF)-beta, vascular endothelial growth factor (VEGF), CD34, and CD68; immunoblot analysis for VEGF; and terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling (TUNEL) method. The ligamentum flavum showed fragmented and disorganized elastic fiber bundles with increased collagen fibrils in the matrix. Calcium deposition, which was identified as calcium pyrophosphate dihydrate crystals, was evident in 72 of 198 patients and in 99 of 270 samples, and was associated with appearance of hypertrophic chondrocytes and new blood vessel formation. Areas of calcium deposits were surrounded by abundant hypertrophic chondrocytes (with marked immunoreactivity to TGF-beta and VEGF) and a significant number of TUNEL-positive chondrocytes. Calcium crystal deposition in the lumbar ligamentum flavum progresses with reduction in elastic fibers and accumulation of collagen fibrils in the matrix as well as expansion of chondrometaplastic areas.

Light and Scanning Electron Microscopic Study of the Tongue in the Cormorant Phalacrocorax carbo (Phalacrocoracidae, Aves)

The tongue of the cormorant Phalacrocorax carbo is a small, immobile structure with a length of 1.4 cm, situated in the middle part of the elongated lower bill. The uniquely shaped tongue resembles a mushroom, with a short base and an elongated dorsal part with sharpened anterior and posterior tips. A median crest can be observed on the surface of the tongue. Examination by light and scanning electron microscopy revealed that the whole tongue is formed by a dense connective tissue with many bundles of elastic fibers. The lingual mucosa is covered by a multilayered keratinized epithelium. The thickest, horny layer of the lingual epithelium was observed on the surface of the median crest and on the posterior tip of the tongue. Lingual glands are absent in cormorants. The framework of the tongue is composed of a hyoid cartilage incorporated into the base. The localization and structure of the tongue in the cormorant show that it is a rudimentary organ and that the lingual body, usually well-developed in birds, is conserved.

ラット顎関節の発生に関する組織学的研究

The early development of the mandibular condyle, the temporal bone, and the articular disc in the temporomandibular joint was investigated histologically in the rat from prenatal day 14 through postnatal day 6. Serial sagittal sections of each of these areas were prepared, and aldehyde fuchsin (AF) staining was used for the most part to determine the elastic fiber content of the sections.Semilunar areas, densely stained with AF, were identified on the posterior aspect of the mandibular condyle anlage on prenatal day 16. This region increased with time and developed into elastic fiber bundles of the retrodiscal tissue on postnatal day (P) O. The superior articular cavity developed on prenatal day 20, and the inferior articular cavity appeared on PO. Thus, the articular disc was discernible on PO. The articular disc contained abundant elastic fibers throughout: in the anterior band, the intermediate zone, and the posterior band. The posterior band of the articular disc contained abundant elastic fibers in the inferior region of the sagittal section, and fewer elastic fibers in the superior region. In the retrodiscal tissue a bundle of elastic fibers extended from the inferior region of the disc to the posteroinferior region, where the bundle divided into two branches. One proceeded inferiorly into the perichondrium of the mandibular condyle, and the other coursed superiorly in the posterior region and entered the adventitia of an adjacent large vein.

Linear focal elastosis: A review of three cases in young Japanese men

Linear focal elastosis in three young Japanese men is described. The lesions are asymptomatic palpable yellow strialike bands extending horizontally across the middle and lower parts of the back. They are histologically composed of many fine wavy bundles of elastic fibers separating the dermal collagen bundles. Electron microscopy demonstrates numerous elongated and fragmented elastic fibers.

A morphological study of the fibrous capsule of the human lumbar facet joint.

Macroscopic and microscopic investigations of the human lumbar facet joint capsule were undertaken. To describe the morphologic characteristics of the fibrous capsule of the lumbar facet joints. Previous biomechanical and neurophysiologic studies by the authors have shown that the lumbar facet joint capsule may be a source of low back pain. Macroscopic investigation was performed on the facet joint capsules dissected from five fresh adult cadavers. For microscopic studies, facet joint capsules obtained from cadaver dissection and spinal surgeries were stained by the hematoxylin and eosin method and the Elastica-Van Gieson method. The outer layer of the fibrous capsule is a dense regular connective tissue that is composed of parallel bundles of collagenous fibers. The inner layer of the fibrous capsule consists of bundles of elastic fibers, similar to the ligamentum flavum. In the superior and middle part of the joint, the fibers run in the medial to lateral direction, crossing over the joint gap. In the inferior part of the joint, the fibers are relatively long and run in a superior-medial to inferior-lateral direction, covering the inferior articular recess. They are thicker than the layer in the superior and middle parts of the joint. Anatomical and histologic features of the lumbar facet joint capsule are different between its outer layer and inner layer. This complex of morphologic factors can affect the biomechanics and neurophysiology of the lumbar facet joint.

Linear Focal Elastosis

Figure 1. Semithin (1-μm) section demonstrated increased amount of thin and fragmented elastic fibers (toluidine blue stain, ×240). Figure 2. Electron microscopy shows irregular fragmented and degenerating elastic fibers (original magnification ×9000). fibers characterized by thin, wavy, elongated as well as fragmented elastic fiber bundles. von Kossa's stain for calcium deposition was negative. Electron microscopy revealed numerous elongated thin, irregular, and fragmented elastic fibers ( Figure 2 ). Some fragments demonstrated central electron-lucent homogenous material with focal densities. Others showed irregularly shaped swollen fibers with degenerative changes. In addition, many elastic fibers were observed in close association and sometimes in contact with fibroblasts. Finely granular electron-dense material was observed in the matrix surrounding these elastic fibers. Fine cytoplasmic microfibrils were noted in the rare fibroblasts with associated elastic fibers. Comment. Burket et al 1 coined the term linear focal elastosis and proposed the synonym elastotic striae . At first glance, the lesions resemble

Ultrastructure of the Rat Papillary Muscle-Chorda Tendineae Junction

The papillary muscle and chordae tendineae of the rat tricuspid valve were treated with tannic acid-glutaraldehyde fixative and examined with an electron microscope. In the junctional region, the papillary muscle cell tapered abruptly and separated into many processes. One end of bundles of elastic fibers approached these processes or lateral sides of the muscle cell and the other end extended in a longitudinal direction toward the chordae tendineae. Fine networks of elastic fibers were observed in the subendothelial layer of the junctional region.

Structure and mechanical properties of the human aortic valve

1. The individual elements of the aortic valve have significantly different architectures. 2. The differences in the mechanical properties of the aortic valve elements are the result of features of the orientation of the collagen and elastic fibers, their interrelationship and quantitative ratio. There is an interrelationship between the collagen and elastic fiber bundles. 3. The arrangement and orientation of the fibrous structures and their packing in the elements of the aortic valve are functions of the load acting on the element. Thus, the architectural features of the individual elements, which provide for the required functioning of the valve, should be the basis for the development of new types of artificial aortic valves.

Elastic behavior of the lungs in healthy children determined by means of an exponential function

In order to evaluate the elastic properties of the lungs in children, a new exponential sigmoid curve fitting model was developed with the function V l = Vm + ( V m /1 + b · e −K · Pst) , where V l is the lung volume, Pst the static recoil presure, V m and Vm the upper and the lower asymptotes (limits of lung volume) and K and b are specific constants. Pressure-volune (PV) data obtained from tidal breathing cycles at different inflation and deflation levels from function residual capacity (FRC) up to approximately 90% total lung capacity (TLC) in 16 healthy have been evaluated by this model. K in relation to age, calculated by the least square nonlinear regression analysis decreased during childhood, whereas 1n b increased. It seems that K (a volume-independent index of compliance and laveolar distensibility) is influenced by the increasing numbe of elastic fiber bundles, changes in the surface/volume ration and finally by changes in the composition of the surfactant. It can be seen that this model is not only restricted to higher lung volumes, the lower limb of the S-shaped curve is also represented.