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Collagen Fibres (collagen + fibre)
Selected AbstractsSelected pathological, immunohistochemical and ultrastructural changes associated with an infection by Diphyllobothrium dendriticum (Nitzsch, 1824) (Cestoda) plerocercoids in Coregonus lavaretus (L.) (Coregonidae)JOURNAL OF FISH DISEASES, Issue 8 2007B S Dezfuli Abstract The pathological changes induced by an infection of Diphyllobothrium dendriticum (Nitzsch, 1824) plerocercoids in powan, Coregonus lavaretus (L.), from Loch Lomond, Scotland, were assessed using immunohistochemical and ultrastructural techniques. In a sample of 26 powan, the occurrence of encysted plerocercoids of D. dendriticum on the outer surface of the stomach was 38.5% (n = 10) with the number of cysts ranging from 4 to 15 and measuring 4.2 ± 1.0 mm × 3.4 ± 0.9 mm (mean ± SD). Histological examination of intestinal samples also revealed plerocercoids (2,21) encapsulated within a proliferation of mesenteric fibrous tissues of the gastric wall and, occasionally, by the gut lamina propria-submucosa and lamina muscularis. In section, cysts were tri-layered and were formed from a series of concentric whorls of fibroblast and collagen fibre-based connective elements. The extent of necrosis within each muscle layer and the serosa of the stomach differed, notably within the latter that was marked by a chronic inflammatory reaction and fibrosis. Within the cyst and around it, a large number of degranulating mast cell/eosinophilic granule cells were seen, in addition to melano-macrophage centres. Immunohistochemical staining of sections of infected stomach revealed a high density of elements, in close proximity to plerocercoids, staining positive for serotonin, bombesin, substance P and galanin. Uninfected material did not present the same levels of activity. Sections through both infected and uninfected tissue were also tested for elements containing vasoactive intestinal peptide, met-enkephalin, calcitonin gene-related peptide, neuropeptide Y and nitric oxide synthase, but these were absent. [source] A double three-step theory of brain metastasis in mice: the role of the pia mater and matrix metalloproteinasesNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 3 2007N. Saito The brain is frequently affected by the spread of lung cancer, and haematogenous metastasis is a common route to brain metastasis. We therefore developed an isogenic brain metastasis model of lung cancer to use the Lewis lung carcinoma cell line and analysed dynamics of neoplastic cells after extravasation. Histological analysis revealed two characteristic patterns: metastatic foci exhibiting an angiocentric pattern were designated ,perivascular proliferations'; neoplastic cells infiltrating the brain parenchyma were designated ,invasive proliferations'. Electron microscopic observation of perivascular proliferations showed that neoplastic cells were confined to the perivascular space. In invasive proliferations, however, fragments of collagen fibre were observed in the gaps between neoplastic cells, indicating that the neoplastic cells had disintegrated the pia-glial membrane. We analysed the expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 by using both immunohistochemical analysis and real-time polymerase chain reaction analysis. MMP-2 expression was significantly higher in invasive proliferations. MMP-9 expression was significantly higher in day 7, but there was no significant difference in day 11. The pia-glial membrane and perivascular space are the barriers that neoplastic cells must overcome to infiltrate the brain. In conclusion, our findings suggest that brain metastasis requires two distinct processes. [source] Anisotropy of spin relaxation of water protons in cartilage and tendonNMR IN BIOMEDICINE, Issue 3 2010Konstantin I. Momot Abstract Transverse spin relaxation rates of water protons in articular cartilage and tendon depend on the orientation of the tissue relative to the applied static magnetic field. This complicates the interpretation of magnetic resonance images of these tissues. At the same time, relaxation data can provide information about their organisation and microstructure. We present a theoretical analysis of the anisotropy of spin relaxation of water protons observed in fully hydrated cartilage. We demonstrate that the anisotropy of transverse relaxation is due almost entirely to intramolecular dipolar coupling modulated by a specific mode of slow molecular motion: the diffusion of water molecules in the hydration shell of a collagen fibre around the fibre, such that the molecular director remains perpendicular to the fibre. The theoretical anisotropy arising from this mechanism follows the ,magic-angle' dependence observed in magnetic-resonance measurements of cartilage and tendon and is in good agreement with the available experimental results. We discuss the implications of the theoretical findings for MRI of ordered collagenous tissues. Copyright © 2009 John Wiley & Sons, Ltd. [source] A discourse on cancer cell chemotaxis: Where to from here?IUBMB LIFE, Issue 2 2007Lilian L. Soon Abstract The study of cancer cell chemotaxis on two-dimensional surfaces in vitro has relevance to the diverse migratory behaviours exhibited in vivo that involve a directed path. These may include translocation along collagen fibres, invasion into the basement membrane and across stroma, intravasation and extravasation to arrive at a secondary destination designated for cancer cell colonization. Chemotaxis invariably denotes the ability of cells to sense gradients, polarize, adhere and deadhere to substrate, and translocate in the right direction. Amongst these, the sensing function is perhaps the unifying aspect of different migration styles, permitting the cells to resolve its orientation and path. This review examines the decision-making processes that take place during chemotaxis and illustrates that a universal mechanism is involved. In various cell types from Dictyostelium to neutrophils, there are some unifying principles that dictate sensing and how the putative leading edge and trailing end of cells are determined. Some of these principles have recently been applied in the study of cancer cell chemotaxis albeit different pathways are substituted. In amoeboid-like cancer cells, local excitation of the EGFR/PLC,/cofilin pathway and parallel, global inhibition of cofilin by LIMK occur to promote the asymmetric distribution and amplification of these internal signals in response to an external EGF gradient. IUBMB Life, 59: 60-67, 2007 [source] Ultrastructural study of the temporomandibular joint after unilateral meniscectomy in Wistar ratsJOURNAL OF ORAL REHABILITATION, Issue 10 2006D. T. MARTINI summary, Meniscectomy of the temporomandibular joint (TMJ) was frequently performed until a few years ago but now is seldom employed. This procedure induces important articular modifications but the complete extent of ultrastructural changes is still unknown. Twenty-one Wistar rats were submitted to unilateral meniscectomy. Animals were randomly divided into three groups and followed for 15, 35 or 60 days. After killing both meniscectomized and contralateral TMJ specimens were sectioned sagittally and prepared for light and scanning electron microscopy studies. Normal TMJs are characterized by glenoid fossa and condylar process with distinct conjunctive layers in which regularly arranged type 1 collagen fibres predominate. Meniscectomized animals initially exhibit a different tissue covering the eroded articular surface of the condyle with the prevalence of type 3 collagen fibres but type 1 fibres predominate in the late postoperative period. Subchondral cysts are clearly visible. A complex remodelling process of the TMJ after meniscectomy is evident with important ultrastructural modifications that may correlate to unsatisfactory clinical results. The dynamic nature of this process is also observed when specimens from different postoperative periods are compared. Surgeons should always bear in mind these alterations when indicating this procedure. [source] Ligament creep recruits fibres at low stresses and can lead to modulus-reducing fibre damage at higher creep stresses: a study in rabbit medial collateral ligament modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2002G. M. Thornton Ligaments are subjected to a range of loads during different activities in vivo, suggesting that they must resist creep at various stresses. Cyclic and static creep tests of rabbit medial collateral ligament were used as a model to examine creep over a range of stresses in the toe- and linear-regions of the stress,strain curve: 4.1 MPa (n =7), 7.1 MPa (n = 6), 14 MPa (n = 9) and 28 MPa (n = 6). We quantified ligament creep behaviour to determine if, at low stresses, modulus would increase in a cyclic creep test and collagen fibres would be recruited in a static creep test. At higher creep stresses, a decrease in measured modulus was expected to be a potential marker of damage. The increase in modulus during cyclic creep and the increase in strain during static creep were similar between the three toe-region stresses (4.1, 7.1, 14 MPa). However, at the linear-region stress (28 MPa), both these parameters increased significantly compared to the increases at the three toe-region stresses. A concurrent crimp analysis revealed that collagen fibres were recruited during creep, evidenced by decreased area of crimped fibres at the end of the static creep test. Interestingly, a predominance of straightened fibres was observed at the end of the 28 MPa creep test, suggesting a limited potential for fibre recruitment at higher, linear-region stresses. An additional 28 MPa (n = 6) group had mechanically detectable discontinuities in their stress,strain curves during creep that were related to reductions in modulus and suggested fibre damage. These data support the concept that collagen fibre recruitment is a mechanism by which ligaments resist creep at low stresses. At a higher creep stress, which was still only about a third of the failure capacity, damage to some ligaments occurred and was marked by a sudden reduction in modulus. In the cyclic tests, with continued cycling, the modulus increased back to original values obtained before the discontinuity suggesting that other fibres were being recruited to bear load. These results have important implications for our understanding of how fibre recruitment and stress redistribution act in normal ligament to minimize creep and restore modulus after fibre damage. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Linear atrophoderma of Moulin together with leuconychia: a case reportJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2006M Atasoy Abstract Linear atrophoderma of Moulin has a distinctive disease pattern characterized by hyperpigmented atrophoderma and was described originally in 1992. It follows the line of Blaschko, and occurs without preceding inflammation, subsequent induration or scleroderma. The lesions usually develop during childhood or adolescence, and the prognosis is good. The diagnosis is made clinically and histopathologically. In our 18-year-old male patient, there were atrophic plaques unilaterally located on the trunk and arm, and white discoloration on all finger nails. Histopathological examination revealed epidermal atrophy together with disruption of collagen fibres. [source] Wound healing response is a major contributor to the severity of cutaneous leishmaniasis in the ear model of infectionPARASITE IMMUNOLOGY, Issue 10 2007T. BALDWIN SUMMARY In the conventional mouse model for cutaneous leishmaniasis involving infection with stationary phase Leishmania major promastigotes at the base of the tail, mice congenic for leishmaniasis resistance loci designated lmr1,2,3 cured their lesions more rapidly and laid down more ordered collagen fibres than the susceptible parental BALB/c mice, while the opposite was the case for the congenic mice carrying the susceptibility loci on the resistant C57BL/6 background. In that model, we showed that wound healing and not T cell responses played a major role in determining the resolution of skin infection. Here, we show a similar disease phenotype in the mouse model that mimics more closely the situation in humans, that is, strictly intradermal infection in the ear pinna with small numbers of metacyclic promastigotes. The data show that at the site of infection the innate and adaptive immune responses act in concert to clear parasites, and induce tissue repair and wound healing. Importantly, the data show that the host responses controlled by the lmr loci, which act locally to control infection in the skin, are distinct from the host responses operating systemically in the draining lymph node. [source] Histological Studies of Growing and Mature Antlers of Red Deer Stags (Cervus elaphus)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009M. Cegielski Summary This study aims at presenting histology of growing and mature antlers in red deer stag (Cervus elaphus). Growing antlers constitute a model organ for examining regeneration processes of tissues because they are the only mammalian appendages capable of regeneration. Histological study revealed that the tip of a growing antler consists of hairy skin, perichondrium, mesenchyme and chondroprogenitors area. By performing immunochistochemistry, we found that cell expressing Ki-67 and PCNA antigens were localized in basal layer of epidermis, skin glands and beneath their secretory sections, mesenchyme as well as within and in the vicinity of central blood vessels. Ultrastructurally, cells from chondroprogenitors zone have chondroblast-like morphology and take part in producing of collagen fibres followed by the process of cartilage mineralization. However, mature antlers also consist of lamellar osseous tissue. [source] Ankyloglossia in Dogs: A Morphological and Immunohistochemical StudyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009S. Karahan Summary Ankyloglossia is a congenital anomaly of the tongue that is usually characterized by a short and thick lingual frenulum. The genetic mutations such as in TBox genes and other foetal mechanism have still been under investigation as possible causes of ankyloglossia. This study describes morphology of anklyoglossia phenotype found in members of two closely bred Kangal dog families. Morphology of ankyloglossia and immunohistochemical localization of ,B-crystallin, an anti-apoptotic protein, in the frenulum tissue collected during frenectomy was described. Grossly, the lingual frenulum was observed as it extended up to the tip or near the tip of the tongue. The tip of the tongue was often notched and appeared in ,W' shape. No other craniofacial anomalies were associated with ankyloglossia. Histologically, the frenulum tissue was covered by stratified squamous epithelia of variable thickness. Skeletal muscle fibres were often scattered in the vicinity of collagen fibres of the lamina propria. ,B-crystallin was immunolocalized exclusively in skeletal muscle fibres. In conclusion, ankyloglossia in the dog generally occurs as a sole anomaly. The presence of ,B-crystallin immunoreactivity exclusively in skeletal muscle fibres suggests that there may be a connection between occurrences of ankyloglossia in the dog and a delay or interference with apoptosis of the skeletal fibres in the frenulum tissue. [source] Characteristics of Filiform, Fungiform and Vallate Papillae and Surface of Interface Epithelium-Connective Tissue of the Maned Sloth Tongue Mucosa (Bradypus torquatus, Iliger, 1811): Light and Scanning Electron Microscopy StudyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2009E. J. Benetti Summary The study of lingual surfaces and the surface of interface epithelium-connective tissue of the tongue of Bradypus torquatus was performed by employing the light and scanning electron microscopy (SEM) techniques. The results revealed that the rostral part of the tongue presents a round apex and covered by filiform and fungiform lingual papillae and a ventral smooth surface. It was observed that the epithelial layer of the dorsal surface possesses the basal, spinosum, granular and cornified epithelial cells. The lamina propria is characterized by a dense connective tissue forming the long, short and round papillae. Numerous typical filiform papillae are located especially in the rostral part intermingled for few fungiform papillae, which were revealed in three-dimensional SEM images. Usually, the fungiform papillae are located in the border of rostral apex of the tongue exhibiting the rounded form. They are covered by keratinized epithelial cells. In the fungiform papillae, several taste pores were observed on the surface. The vallate papillae presented numerous taste buds in the wall of epithelial cells, being that the major number of taste buds is located on the superior half of vallate papilla. The taste pores are surrounded by several laminae of keratinized epithelial cells. The samples treated with NaOH solution and examined by SEM revealed, after removal of the epithelial layer, the dense connective core in original disposition, presenting different sizes and shapes. The specimens stained with Picrosirius and examined by polarized light microscopy revealed the connective tissue, indicating the collagen fibres type I and type III. [source] l -Arginine Inhibits Isoproterenol-Induced Cardiac Hypertrophy through Nitric Oxide and Polyamine PathwaysBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2008Yan Lin Nitric oxide exhibits antihypertrophic functions and inhibits cardiac remodelling. However, the metabolism of polyamines and the potential interactions with nitric oxide in cardiac hypertrophy remain unclear. We randomly divided Wistar rats into four treatment groups: controls, isoproterenol (ISO), ISO and l -arginine, and l -arginine. Isoproterenol (5 mg/kg/day, subcutaneously) and/or l -arginine (800 mg/kg/day, intraperitoneally) was administered once daily for 7 days. The expression of atrial natriuretic peptide mRNA was determined by reverse transcription,polymerase chain reaction, and fibrogenesis of heart was assessed by Van Gieson staining. Polyamines were measured with high-performance liquid chromatography, and plasma nitric oxide content and lactate dehydrogenase (LDH) activity were determined with a spectrophotometer. The expression levels of ornithine decarboxylase, spermidine/spermine N1-acetyltransferase (SSAT), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) were analysed by Western blot. Heart-to-body weight ratio, left ventricle-to-body weight ratio, atrial natriuretic peptide mRNA expression, collagen fibres and LDH activity were elevated, both ornithine decarboxylase and SSAT proteins were up-regulated, and total polyamines were increased in the group treated with ISO. Additionally, the expression of iNOS was up-regulated, eNOS was down-regulated, and nitric oxide levels were low. Notably, cotreatment with l -arginine reversed most of these changes except for SSAT expression, which was further up-regulated. We propose that increased polyamines and decreased nitric oxide are involved in cardiac hypertrophy induced by ISO and suggest that l -arginine pre-treatment can attenuate cardiac hypertrophy through the regulation of key enzymes of the polyamine and nitric oxide pathways. [source] The ultrastructure of the capillaries in the gingiva of alloxan-induced diabetic ratsCELL BIOCHEMISTRY AND FUNCTION, Issue 4 2003Nursel Gül Abstract The diabetic effects of alloxan (type I diabetes mellitus) were investigated in 40 Wistar albino rats (18 controls and 22 diabetics). Alloxan in sterile physiological saline was injected into animals intravenously. After the induction of diabetes with alloxan, the ultrastructure of the capillaries in the gingiva was examined by transmission electron microscopy. The thickness of the basement membranes was observed closely adherent to the endothelial cells of the capillary alloxan-diabetic rats. It was greatly thickened owing to the increase in its amorphous, granular and filamentous material with occasional scattered collagen fibres. In some sections, the capillary lumens of the diabetics were closed by epithelial cells. Loss of cytoplasmic material and hyalinization were seen in some smooth muscle cells. In addition, the mitochondrial cristae of smooth muscle cell and epithelial cells disappeared. There was endothelial integrity throughout the smooth muscle cells. Copyright © 2003 John Wiley & Sons, Ltd. [source] Central corneal thickness in children with growth hormone deficiencyACTA OPHTHALMOLOGICA, Issue 6 2010Fulvio Parentin Acta Ophthalmol. 2010: 88: 692,694 Abstract. Purpose:, To evaluate central corneal thickness (CCT), intraocular pressure (IOP) and eye refraction in patients with congenital growth hormone (GH) deficiency. Methods:, Retrospective case series. Forty-five patients with growth defect treated with recombinant GH and 45 healthy children underwent ophthalmological examination, including CCT measurements, applanation tonometry and cycloplaegic refraction. Results:, The average CCT in the GH deficiency group was 570.6 ,m [standard deviation (SD) 37.4]. In the control group, it was 546.0 (SD 24.9). The average IOP in the GH deficiency group was 18.2 mmHg (SD 3.4). In the control group, it was 14.6 (SD 2.0). The mean refractive error (spherical equivalent) in the GH deficiency group was 0.59 D (SD 1.9). In the control group, it was 0.11 (SD 2.1). Conclusion:, GH and insulin-like growth factor 1 are involved in ocular growth by influencing the synthesis of the extracellular matrix of the sclera. Children with congenital GH deficiency or insensitivity have a mean hyperopic defect related to a shorter axial length. A number of studies have demonstrated that CCT in newborns is significantly greater than in adults; a decrease in CCT is closely correlated with an increase in corneal diameter. This finding suggests that the growth of the eye, with possible remodelling and stretching of collagen fibres, may play an important role in the reduction of corneal thickness in the first years of life. Therefore, we conclude that a greater CCT can represent a sign of a delayed growth of the eye in patients with GH deficiency. Finally, our study confirms the influence of corneal thickness on IOP measures, and the prevalence of hyperopia among children with growth defect. [source] Guttate morphoea in human T-cell lymphoma/lymphotrophic virus type-1 (HTLV-1) infectionCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 4 2003N. Oiso Summary A 62-year-old Japanese man presented with multiple small atrophic macules on the trunk and extremities. The lesions were discrete, oval in shape and enclosed by lilac ring. They were distributed in a Christmas tree distribution, reminiscent of pityriasis rosea. Skin biopsy showed increased collagen fibres in the dermis and invading subcutaneous tissue. The clinico-pathological features were consistent with guttate morphoea, a rare variant of localized scleroderma. Serological tests revealed a positive reaction to human T-cell lymphoma/lymphotropic virus type-1 infection. [source] | |||||||||||||