Appearance Of Collagen Fibers Research Articles

Machine learning-enabled cancer diagnostics with widefield polarimetric second-harmonic generation microscopy

The extracellular matrix (ECM) collagen undergoes major remodeling during tumorigenesis. However, alterations to the ECM are not widely considered in cancer diagnostics, due to mostly uniform appearance of collagen fibers in white light images of hematoxylin and eosin-stained (H&E) tissue sections. Polarimetric second-harmonic generation (P-SHG) microscopy enables label-free visualization and ultrastructural investigation of non-centrosymmetric molecules, which, when combined with texture analysis, provides multiparameter characterization of tissue collagen. This paper demonstrates whole slide imaging of breast tissue microarrays using high-throughput widefield P-SHG microscopy. The resulting P-SHG parameters are used in classification to differentiate tumor from normal tissue, resulting in 94.2% for both accuracy and F1-score, and 6.3% false discovery rate. Subsequently, the trained classifier is employed to predict tumor tissue with 91.3% accuracy, 90.7% F1-score, and 13.8% false omission rate. As such, we show that widefield P-SHG microscopy reveals collagen ultrastructure over large tissue regions and can be utilized as a sensitive biomarker for cancer diagnostics and prognostics studies.

Extracorporeal shock waves trigger tenogenic differentiation of human adipose-derived stem cells

ABSTRACTPurposes: Incomplete tendon healing impairs the outcome of tendon ruptures and tendinopathies. Human Adipose-derived Stem Cells (hASCs) are promising for tissue engineering applications. Extracorporeal Shock Waves (ESW) are a leading choice for the treatment of several tendinopathies. In this study, we investigated the effects of ESW treatment and tenogenic medium on the differentiation of hASCs into tenoblast-like cells. Materials and Methods: hASCs were treated with ESW generated by a piezoelectric device and tenogenic medium. Quantitative real-time PCR was used to check the mRNA expression levels of tenogenic transcription factors, extracellular matrix proteins, and integrins. Western blot and immunofluorescence were used to detect collagen 1 and fibronectin. Collagen fibers were evaluated by Masson staining. Calcium deposition was assessed by Alizarin Red staining. Results: The combined treatment improved the expression of the tendon transcription factors scleraxis and eyes absent 2, and of the extracellular matrix proteins fibronectin, collagen I, and tenomodulin. Cells acquired elongated and spindle shaped fibroblastic morphology; Masson staining revealed the appearance of collagen fibers. Finally, the combined treatment induced the expression of alpha 2, alpha 6, and beta 1 integrin subunits, suggesting a possible role in mediating ESW effects. Conclusions: ESW in combination with tenogenic medium improved the differentiation of hASCs toward tenoblast-like cells, providing the basis for ESW and hASCs to be used in tendon tissue engineering.

Differential viral haemorrhagic septicaemia virus genotype IVb infection in fin fibroblast and epithelial cell lines from walleye, Sander vitreus (Mitchill), at cold temperatures.

A cell line, WE-cfin11e, with an epithelial-like morphology was developed from a caudal fin of walleye, Sander vitreus (Mitchill), characterized as distinct from the established walleye caudal fin fibroblast-like cell line, WE-cfin11f, and compared with WE-cfin11f for susceptibility to VHSV IVb. Immunocytochemistry and confocal microscopy were used to localize the intermediate filament protein, vimentin, the tight junction protein, zonula occludens-1 (ZO-1), the extracellular matrix protein, collagen I, and the viral protein, G. Although both cell lines contained vimentin, only WE-cfin11e stained for ZO-1 and only WE-cfin11f stained for collagen I. Ascorbic acid increased the accumulation of collagen I and caused the appearance of collagen fibres only in WE-cfin11f cultures. At 14 °C, both cell lines produced VHSV IVb, but the infection developed more rapidly in WE-cfin11f. At 4 °C, both cell lines became infected with VHSV IVb as judged by the expression of viral proteins, N and G, but only WE-cfin11f produced virus. The results suggest that cold temperatures can modulate viral tropism.

Оценка эффективности комплексного лечения ран мягких тканей с применением окситоцина и аквакомплекса глицеросольвата титана в эксперименте

Purpose of the study is to assess the efficiency use of oxytocin and titanium aquacomplex glycerosol-vate in the treatment of soft tissue wounds. The study was carried out on 72 white mongrel male rats weighing 210 ± 10 g with simulated aseptic wounds. The sampling was carried out for 1, 3, 5 and 7 days from the beginning of the experiment. To assess the course of wound process in the clinical study, planimetric and histological methods were applied. The comparison of obtained results has allowed to reveal the high efficacy of combined use of oxytocin and glycerosolvate titanium. On the basis of clinical and planimetric methods of investigation it was established that reduction of the area of the wound is significantly faster in animals treated with the use of oxytocin and glycerosolvate titanium. This treatment has a stimulating effect on the activity of connective tissue - accelerates the appearance and maturation of granulation tissue, occur earlier replacement of a number of inflammatory cells into cells, which provide proliferation; earlier appearance of collagen fibers and the prevalence among them horizontally. The use of oxytocin and titanium aquacomplex glycerosolvate in laboratory animals with aseptic wounds influences positively on the dynamic of wounded process, allows to accelerate the appearance of granulation tissue and epithelialization.

Structural alterations of the mucosa stroma in the Barrett's esophagus metaplasia‐dysplasia‐adenocarcinoma sequence

Accumulating evidence suggests that the extracellular matrix play important roles in intercellular communications and contribute to the development of a number of diseases, including diseases of the gastrointestinal tract. The present study examined the structural characteristics and alterations of the extracellular matrix of the mucosa stroma in the Barrett's esophagus metaplasia-dysplasia-adenocarcinoma sequence. A total of 41 esophageal tissue specimens (15 esophageal adenocarcinoma, 10 Barrett's esophagus intestinal metaplasia, seven dysplasia and nine normal esophagus) were studied. The present study used transmission electron microscopy and computerized quantitative electron-microscopic analysis in order to investigate the characteristics of the extracellular matrix of the mucosa. The study revealed that marked structural alterations of the mucosa stroma, relating to changes in the distribution and appearance of collagen fibers as well as to changes in numbers of matrix microvesicles, occur in Barrett's esophagus and esophageal adenocarcinoma. It was found that there were 3.1 times more microvesicles in the stroma in Barrett's esophagus than in the stroma of the normal esophagus (P<0.0001) and that there were 5.8 times more microvesicles in esophageal adenocarcinoma than in the normal esophagus (P<0.0001). There were 1.9 times more microvesicles in esophageal adenocarcinoma than in Barrett's esophagus (P=0.0043). The study demonstrates distinctive alterations of the mucosa stroma extracellular matrix in the metaplasia-dysplasia-adenocarcinoma sequence. The findings suggest that the redistribution of collagen fibers and increases in numbers of matrix microvesicles may play roles in the formation of specialized intestinal metaplasia and the development of adenocarcinoma.

The role of protamine zinc insulin in accelerating wound healing in the rat.

Abstract Protamine zinc insulin significantly increases the bursting strength of experimental abdominal wounds in rats. Better healing was also noticed in these wounds when studied histologically. There was an earlier appearance of collagen fibres in the treated wounds, and these fibres became compact, dense, and welloriented sooner than those in the control animals. There was no significant increase in the quantity of collagen fibres in treated animals when studied by the granuloma pouch technique.

Preliminary comparison of the rupture of human and rabbit anterior cruciate ligaments

Objective. This study was aimed at examining ruptures of the human anterior cruciate ligaments by scanning electron microscopy and video imaging and comparing the appearance of the rupture surfaces with those from rabbit anterior cruciate ligaments. Design. The specimens were tested to failure as femur-anterior cruciate ligament–tibia complexes using an Instron 8511 materials testing machine. Background. Rupture of the anterior cruciate ligament is a major clinical problem, leading to instability of the knee joint. Due to the frequency and potential severity of the injuries, a need still exists for information on the biomechanical properties of ligaments under loading conditions, which occur at the time of trauma. Methods. Four human femur-anterior cruciate ligament–tibia complexes were loaded to failure at a displacement rate of 0.008 m/s. Video recordings of the tests were used to study the progress of the ruptures and to compare the modes of failure of the ligaments. Scanning electron microscopy was employed to study the appearance of collagen fibres at the rupture surfaces. Results. The modes of failure of the rabbit anterior cruciate ligament and appearance of the rupture surfaces were similar to those of the human anterior cruciate ligaments. Conclusion. The rabbit anterior cruciate ligament provides a model for investigating failure of the human ligament during trauma. Relevance The results will be of significance since most studies on ligaments are carried out on animal models with the intention of applying the deductions from the results to human ligaments. Examining the appearance of collagen fibres at these surfaces may help us to understand more about what actually happens during and after ligament rupture.

Staining abnormalities of dermal collagen in eosinophil- or neutrophil-rich inflammatory dermatoses of horses and cats as demonstrated with Masson's trichrome stain.

A retrospective study was performed on skin biopsy specimens from horses and cats having eosinophilic granulomas with 'collagen degeneration', eosinophilic skin diseases without 'collagen degeneration' and pyogranulomas without 'collagen degeneration'. Neither the appearance of collagen fibres nor the dominant polymorphonuclear cells, as seen in H & E-stained sections, were predictive of Masson's trichrome findings. Hence, a Masson's trichrome staining abnormality of collagen fibres was no more likely to be present in lesions with 'collagen degeneration' than in those lesions without 'collagen degeneration'. In addition, evaluation of trichrome-stained specimens suggested that there is no collagen degeneration in equine and feline eosinophilic granulomas and that the areas previously referred to as collagen degeneration are more appropriately called flame figures.

Maintaining the line of defense: regeneration of Cuvierian tubules in the sea cucumber Holothuria forskali (Echinodermata, Holothuroidea).

When irritated, individuals of the sea cucumber Holothuria forskali expel a few Cuvierian tubules which lengthen, instantly become sticky, and rapidly immobilize most organisms with which they come into contact. After expulsion, the lost tubules are readily regenerated. When only a few tubules have been expelled, there is often a latent period before the regeneration starts. In contrast, when many tubules have been expelled, the regenerative process starts immediately but proceeds in successive waves of 10 to 30 tubules that begin to regenerate at 10-day intervals. However, in all cases, the complete regeneration of a given tubule takes about 5 weeks and may be divided into three successive phases: an initial repair phase including the overall 48-h post-autotomy period, a true regenerative phase taking about 4 weeks to complete, and a growth phase of about one more week. Initial regeneration events occur by epimorphosis, cell proliferation being essential to the regenerative process, whereas late events occur mainly by morphallaxis, with migration of the newly differentiated cells. The mesothelium is the tissue layer in which cell proliferation is the most precocious and the most important, involving both peritoneocytes and undifferentiated cells (which seem to be dedifferentiated peritoneocytes). As regeneration proceeds, the percentage of undifferentiated cells regularly decreases in parallel with the differentiation of granular (adhesive-secreting) cells and myocytes. The myocytes then separate off from the mesothelium and migrate within the connective tissue layer. Three types of pseudopodial cells follow one another in the tubule connective tissue during regeneration. Type 1 cells have all the characteristics of echinoderm phagocytes and may have a fibroblastic function, cleaning the connective tissue compartment before new collagen synthesis starts. Type 2 cells are rather undifferentiated and divide actively. The presence of type 3 cells is closely associated with the appearance of collagen fibers, and it is suggested that they have a fibroblastic function. In the inner epithelium, cells also divide actively, but only those in which spherules have not yet differentiated in the basal intraconnective processes. It appears, therefore, that in the three tissue layers of the tubules, regeneration proceeds by cell dedifferentiation, then proliferation, and finally by differentiation. Cuvierian tubules thus constitute a very efficient defensive mechanism: their large number, sparing use, and particular regeneration dynamics make them an almost inexhaustible line of defense maintained at limited energy cost.

Appearance of collagen fibers in the cerebral vascular wall following subarachnoid hemorrhage.

Ultrastructural examinations of the cerebral vascular wall following subarachnoid hemorrhage (SAH) demonstrated that collagen fibrils developed in the muscle layer near the adventitia in the early stage of SAH and increased in number and volume with time. These findings suggest that accelerating factors of collagen synthesis in the muscle layer may be released from the adventitial side, and collagen synthesis is induced by extravascular factors. The changes of collagen volume with time suggest collagen to be an important phenomenon of persistent vasospasm after SAH. Histoimmunological studies showed that increased collagen fibers in the tunica media were mainly type III collagen, implying that cerebral vasospasm may be related to chemical inflammation.

Pathology of degenerative osteoarthritis in laying hens.

Degenerative osteoarthritis, similar to that seen in mammals, including man, was observed in the fifth to seventh thoracic vertebral bodies of 58 two-year-old laying hens. Main gross lesions were roughening of the articular surface, narrowing or focal thickening of the articular cartilage, chondrophytes at the margins of the joints, and a decrease in length from the dorsal to ventral edge of the epiphyseal vertebral body. Histopathological changes consisted of degeneration of the matrix with an appearance of collagen fibers, erosion or ulceration, proliferation of chondrocytes, and cleft-like fractures in the articular cartilage, and necrosis and eburnation in the subchondral bone. The degenerative changes with an appearance of collagen fibers in the cartilage matrix were regarded as the initial lesions. The pathogenesis of this disorder was not clarified, however, as in mammals the anatomical characteristics of the thoracic vertebrae, the rearing environments, an anomaly of the chemical constituents of the cartilage with increased age and mechanical stress such as weightiness should be taken into consideration as the important factors.

Effects of parathyroid hormone on osteocytes. Ultrastructural evidence for anisotropic osteolysis and involvement of the cytoskeleton

The effects of acute (24 hours) and chronic (21 days) administration of supraphysiological doses of PTH on the ultrastructure of osteocytes were studied by transmission electron microscopy. After PTH the border of the lacunae was roughened with the appearance of collagen fibers denuded from mineral. The cytoplasmic rim was enlarged, the cell membrane was ruffled and numerous cytoplasmic processes filled the lacunar space. Whithin the cytoplasm an abundance of lysosomes, enlargement of the Golgi apparatus and prominence of the rough endoplasmic reticulum were seen. Occasional autophagosomes were observed. At high doses of PTH extreme abundance of lysosomes and complete dissolution of the plasma membrane were noted. This was accompanied by extensive periosteocytic osteolysis. These findings point to cell death after excessive stimulation of osteocytes by PTH. Numerous microfilaments appeared in the cytoplasm, suggesting involvement of the cytoskeleton in conformational changes of plasma membrane and/or cell motility in response to PTH. Coarse cell processes, densely packed with microfilaments and strikingly reminiscent of lamellae of ameobae, were demonstrable. After acute injection of PTH (12 hours), many microtubules were seen in the cytoplasm, particularly in the Golgi field. These findings document the involvement of the cytoskeleton in the osteocyte response to PTH. There was a striking asymmetry of the periosteocytic osteolysis, i.e. it was more pronounced at the cell pole opposite the nucleus. At the site of increased periosteocytic osteolysis cytoplasmic processes formed cisternae, revealing evidence of active exocytosis. The anisotropic nature of periosteocytic osteolysis may point to spatial orientation of this process and possibly to interaction of osteocytes with bone surface cells.

A Scanning Electron Microscope Study of Intratubular Dentin Fibers

Dentinal tubules have generally been considered to be occupied only by the cytoplasmic processes of odontoblasts. Recently, however, JOHANSEN and PARKS [1] and FRANK [2] found unmineralized collagen fibers along with the odontoblastic process in dentinal tubules. JAMES [3] failed to find odontoblastic processes in the peripheral parts of the dentinal tubules in his histochemical study and this was confirmed by BRANNSTROM and GARBEROGLIO [4]. According to FURSETH and MJOR [5], only an amorphous substance and collagen fibrils were observed in the obturated dentinal tubules in the cortico-steroid covered dentin. Based on these reported studies, there could be a relationship between the appearance of collagen fibers in the dentinal tubule and disappearance of the cytoplasmic process.The present report deals with the intratubular structures observed in the dentinal tubules with a scanning electron microscope.