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Objective:To compare the characteristics of corneal stromal demarcation line after different surgical methods of riboflavin/ultraviolet A corneal collagen cross-linking (CXL) in early keratoconus, and analyze the influence of the demarcation line on the cross-linking effect.Methods:A non-randomized controlled clinical study was conducted.Sixty-nine eyes of 69 patients treated with riboflavin/ultraviolet A CXL in the Eye Hospital of Shandong First Medical University from May 2019 to February 2021 were included.According to the cross-linking methods, the patients were divided into epithelium-on treatment group (21 eyes) and epithelium-off treatment group (48 eyes). There were 25 eyes in 5.4 J energy group and 44 eyes in 7.2 J energy group.The morphology and changes of corneal stromal cross-linking reaction (corneal stromal demarcation line) were observed at 2 weeks, 1, 3 and 4 months after operation.Changes in the thinnest corneal thickness (TCT), uncorrected visual acuity (UCVA, LogMAR), best corrected visual acuity (BCVA, LogMAR) and corneal maximum curvature (Kmax) were recorded.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Eye Hospital of Shandong First Medical University (No.2019.05). Written informed consent was obtained from each subject.Results:Of the 69 eyes after operation, 44 eyes (63.77%) had demarcation lines, and 25 eyes (36.23%) had no demarcation lines.The occurrence rate of demarcation lines in the epithelium-on treatment group was 79.17%(38/48), which was significantly higher than 28.57%(6/21) in the epithelium-off treatment group ( χ2=16.186, P<0.01). The occurrence rate of demarcation line in 5.4 J energy group was 72.00%(18/25), and the 7.2 J energy group was 56.80%(25/44), with no significant difference ( χ2=1.565, P=0.302). Slit lamp microscopy and anterior segment-optical coherence tomography showed that the demarcation line appeared at 1-2 weeks after operation, gradually converged and strengthened after 1 month, turned diffuse, blurred and faded by degrees after 2-3 months, and basically disappeared after 4 months.The depth of the demarcation line reached 141-423 μm, with an average depth of (263.44±84.22)μm.Scanning laser confocal microscopy showed that corneal stromal cells were activated and light reflection was enhanced after CXL.Collagen fibers extended vertically and horizontally, crisscrossed, and were in a reticular arrangement.The TCT decreased from preoperative (458.69±38.28)μm to (443.86±36.54)μm at 4 months after operation, showing a statistically significant difference ( t=6.705, P<0.001). There was no significant difference in the TCT reduction between groups with and without demarcation lines ( t=1.684, P=0.100). At 4 months postoperatively, the UCVA of all eyes increased from preoperative 0.74±0.37 to 0.69±0.38, and the difference was statistically significant ( t=2.109, P=0.039). There was no significant difference in BCVA between before and after operation ( t=1.006, P=0.319). There was no significant difference in change of UCVA and BCVA between groups with and without demarcation lines ( t=0.065, P=0.949; t=0.346, P=0.730). There was no significant difference in Kmax in all patients between before and after operation ( t=0.050, P=0.950). There was no significant difference in the Kmax change between groups with and without demarcation lines ( t=-0.739, P=0.464). The change in TCT in the epithelium-off treatment group was significantly greater than that in the epithelium-on treatment group ( t=2.815, P=0.008). There was no significant difference in UCVA, BCVA and Kmax changes between epithelium-on and epithelium-off treatment groups (all at P>0.05). There was no obvious corneal scarring, infectious keratitis, corneal endothelial decompensation or other complications. Conclusions:The demarcation line after CXL may be a sign of the depth of cross-linking reaction, which is more prone to occur after the epithelium-off operation method.Both the epithelium-on and epithelium-off operation methods have similar therapeutic effects.Demarcation line after different cross-linking methods has no significant influence on the cross-linking effect in keratoconus.
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Objective To investigate the structural distribution features and mechanism of elastic fibers and collagen fibers in ventricular interstitium of aged rats. Methods Five young SD rats (24 weeks) and five old SD rats (104 weeks) were used,and their cardiac function was examined by echocardiography. Modified Weigert elastic fiber staining, immunohistochemistry, immunofluorescence and Western blotting techniques were used to detect the expression changes of type I and IH collagen fibers and their proteins, elastic fibers and their proteins, matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 2 (TIMP-2), respectively. Results The type I and type IH collagen in the ventricular interstitium of aged rats was very sufficient and wrapped around the cardiomyocytes. Compared with the young rats, the content of collagen protein in the ventricular interstitium of the aged rats significantly increased (P<0. 05). Elastic fibers in the ventricular interstitium of the aged rats were and widely distributed. Compared with the young rats, the number of elastic fibers and the level of elastin in the ventricular interstitium of the aged rats significantly decreased (P<0. 05), and the expression levels of MMP-2 and MMP-9 in ventricular muscle of aged rats increased, and the)' were correlated with the level of elastin. The level of TIMP-2 in ventricular muscle of aged rats decreased with age. Conclusion The number of collagen fibers and elastic fibers in ventricular interstitium of aged rats is fluctuated with each other. With the increase of age, the contents of TIMP-2 and elastic fibers in the ventricular interstitium gradually decreased, and the ratio of collagen fibers to elastic fibers is out of balance.
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Objective:To investigate the antagonistic and therapeutic effects of Ginkgo biloba on arsenic-induced lung injury in rats and its mechanism.Methods:A total of 42 healthy clean grade Wistar rats, half male and half female, weighing 120 - 130 g, were randomly divided into 7 groups with 6 rats in each group. Two intervention models of Ginkgo biloba antagonism and treatment were established, respectively. The specific treatments were as follows: (1) Experimental study on the antagonism of Ginkgo biloba (4 groups): the control A group was given deionized water; the Ginkgo biloba control (GBE) group was given Ginkgo biloba solution (50 mg·kg -1·bw); the arsenic-treated (As) group was given sodium arsenite solution (10 mg·kg -1·bw); the Ginkgo biloba antagonistic (As + GBE) group was treated with sodium arsenite solution (10 mg·kg -1·bw) and Ginkgo biloba solution (50 mg·kg -1·bw), and the above administration was by gavage for 6 days/week, for 4 months. (2) Experimental study on the treatment of Ginkgo biloba (3 groups): the control B group was given deionized water for 5.5 months; in the arsenism natural recovery (recovery) group, sodium arsenite solution (10 mg·kg -1·bw) was administered by gavage for 4.0 months and deionized water for 1.5 months; the Ginkgo biloba treatment (treatment) group was given sodium arsenite solution (10 mg·kg -1·bw) by gavage for 4.0 months and Ginkgo biloba solution (50 mg·kg -1·bw) for 1.5 months, and the above administration was for 6 days/week. Masson staining was used to evaluate collagen fiber deposition in lung tissue. Western blotting was used to detect the expression level of related proteins in lung tissue homogenates, including inflammatory cytokines matrix metalloproteinase-9 (MMP-9), interleukin (IL)-1β, IL-18; high mobility group box 1 (HMGB1) and receptor for advanced glycation end-products (RAGE) of the HMGB1/RAGE pathway; phosphatidylinositol-4, 5-bisphosphate 3-kinase (PI3K), protein kinase B (AKT), phosphorylated AKT (p-AKT) of the PI3K/AKT pathway; transforming growth factor (TGF)-β1, SMAD2, p-SMAD2, SMAD3, p-SMAD3 and SMAD4 of the TGF-β1/SMAD pathway. Results:(1) Antagonistic effect of Ginkgo biloba: compared with the control A group, there was no significant change in protein expression and collagen fiber deposition in the lung tissue of GBE group ( P > 0.05); the levels of MMP-9, IL-1β and IL-18 protein expression and collagen fiber deposition in the lung tissue of As group were significantly increased ( P < 0.05); and the levels of HMGB1, RAGE, PI3K, p-AKT, TGF-β1, p-SMAD2, p-SMAD3 and SMAD4 protein expression were significantly increased ( P < 0.05). Compared with As group, the levels of MMP-9, IL-1β and IL-18 protein expression and collagen fiber deposition were significantly decreased in As + GBE group ( P < 0.05); and levels of HMGB1, RAGE, PI3K, p-AKT, TGF-β1, p-SMAD2, and p-SMAD3 protein expression were significantly decreased ( P < 0.05). (2) Therapeutic effect of Ginkgo biloba: compared with control B group, the levels of MMP-9, IL-1β, IL-18 protein expression and collagen fiber deposition were significantly increased in recovery group ( P < 0.05); and the levels of HMGB1, RAGE, PI3K, p-AKT, TGF-β1, p-SMAD2, p-SMAD3 and SMAD4 protein expression were significantly increased ( P < 0.05). Compared with recovery group, the levels of MMP-9, IL-1β, IL-18, HMGB1, RAGE, PI3K and p-AKT protein expression were significantly decreased in treatment group ( P < 0.05); and there was no significant change in collagen fiber deposition and TGF-β1, p-SMAD2, p-SMAD3 and SMAD4 protein expression levels in lung tissue ( P > 0.05). In both experiments, there was no significant difference in the protein expression levels of AKT, SMAD2 and SMAD3 between the groups ( P > 0.05). Conclusion:Ginkgo biloba intervention has ameliorated inflammatory injury and collagen fiber deposition in lung tissue of arsenic-treated rats possibly by inhibiting the expression levels of HMGB1/RAGE pathway-related proteins.
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Objective To study the effect of storage duration on compressive mechanical properties of rabbit patellar, so as to provide references for in vitro ligament storage.Methods The compressive mechanical properties of rabbit patellar ligament storaged at -20 ℃ at different storage durations (in 36 d) were tested with the universal tensile test machine. The microscopic morphology of collagen fibers was observed under the scanning electron microscopy (SEM). The enthalpy and denaturation temperature of collagen fibers were measured with differential scanning calorimetry (DSC).Results With the increase of storage duration, the compressive stress of the patellar ligament at 40% strain increased from 19 kPa to 112 kPa and then decreased to 57 kPa. SEM observation showed that the cross-linking of collagen fibers was initially strengthened and then weakened. DSC results showed that the enthalpy increased from 59.47 J/g to 67.10 J/g and then decreased to 54.43 J/g. The denaturation temperature increased from 67.62 ℃ to 77.28 ℃ and then decreased to 64.10 ℃.Conclusions When rabbit patellar ligament is stored at -20 ℃, with the increase of storage duration, the compressive stress of rabbit patellar ligament at 40% strain increases at first and then decreases. This change may be due to the variation of cross-linking level of collagen fibers. The stronger the cross-linking of collagen fibers, the stronger the compressive mechanical properties will be.
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Objective:To explore the therapeutic effect of adipose-derived stem cells (ADSC) on long-wave UV damage in mouse skin in order to provide ideas for the treatment of skin photodamage.Methods:The inguinal and perirenal adipose tissues of C57BL/6 mice were extracted and processed to obtain mouse ADSCs, and the surface markers, adipogenic and osteogenic differentiation capabilities were identified. The mouse photoaging model was irradiated with the SS-03AB UV illuminator, the total UVB dose was 9.45 J/cm 2, and the total UVA dose was 94.5 J/cm 2. Experimental mice (72 in total) were divided into normal group, model group, DMEM (medium) group and ADSC group, each with 18 mice. In the normal group and model group, the materials were taken two weeks after the end of irradiation. After irradiation, the ADSC group was given a subcutaneous injection of 200 μl ADSC suspension, and the DMEM group was given 200 μl of serum-free medium for treatment, and the materials were taken for pathological staining after 2 weeks. The experimental data was processed by analysis of variance. This study was carried out from August 2018 to July 2019 in the First Affiliated Hospital of Zhengzhou University. Results:The extracted cells were identified as adipose-derived stem cells. HE staining showed that the inflammatory cell infiltration in the ADSC group was significantly reduced compared with the DMEM group ( t=20.649, P<0.001) and the normal group ( t=16.147, P<0.001), and the thickness of the dermis layer was significantly increased. Masson staining showed collagen fibers were arranged neatly and the density increased significantly after ADSC treatment. Conclusions:Subcutaneous injection of ADSC can reduce inflammation, promote collagen tissue proliferation, increase the thickness of the dermis, effectively resist inflammatory damage and collagen breakdown caused by UVB.
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Objective To investigate the effects of persistent Echinococcus multilocularis infections on hepatic fibrosis in mice, so as to provide insights into the understanding of liver fibrogenesis induced by E. multilocularis infections and the treatment of alveolar echinococcosis. Methods Hepatic stellate HSC-T6 and LX-2 cells were exposed to the sera (25, 50 and 100 μL) from Meriones unguiculatus infected with E. multilocularis, and E. multilocularis, germinal layer cells (GCs) and protoscoleces (PSCs) for 48 hours, respectively. The cell proliferation was measured using a CCK-8 assay, and the levels of collagen 1 (Col1) and α-smooth muscle actin (α-SMA) were measured in the culture supernatant of HSC-T6 cells using ELISA. In addition, the serum and liver samples were collected 1, 2, 4, 6, 8 months post-infection with E. multilocularis, respectively. The serum Col1 and α-SMA concentrations were measured using enzyme-linked immunosorbent assay (ELISA), and the deposition of collagen fibers was examined in mice livers using Sirius red staining. Results The sera of E. multilocularis-infected gerbils promoted the proliferation of HSC-T6 and LX-2 cells in vitro, and there were significant differences seen in the proliferative rate of HSC-T6 (FHSC-T6 = 126.50, P < 0.05) and LX-2 cells (FLX-2 = 201.50, P < 0.05) among different serum groups, with the highest proliferative rate of HSC-T6 (573.36% ± 206.34%) and LX-2 cells (940.38% ± 61.65%) found following exposure to 100 μL mouse sera. Exposure to serum from E. multilocularis-infected gerbils resulted in an increase in the Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, with the greatest Col1 (20.99 ng/mL ± 2.01 ng/mL) and α-SMA levels (305.52 pg/mL ± 16.67 pg/mL) measured following exposure to 100 μL sera. The metacestodes (142.65% ± 9.17% and 189.99% ± 7.75%), GCs (118.55% ± 8.96% and 122.54% ± 0.21%) and PSCs of E. multilocularis (156.34% ± 17.45% and 160.59% ± 31.41%) all promoted the proliferation of HSC-T6 and LX-2 cells in vitro, and there were significant differences in the proliferative rates of HSC-T6 (FHSC-T6 = 11.24, P < 0.05) and LX-2 cells among groups (FLX-2 = 47.72, P < 0.05). Exposure to E. multilocularis resulted in an increase in Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, and the highest Col1 (4.43 ng/mL ± 2.23 ng/mL) and α-SMA levels (285.20 pg/mL ± 90.67 pg/mL) were detected following treatment with E. multilocularis metacestodes. In addition, a persistent increase was seen in the deposition of collagen fibers in mice livers 1 to 8 months post-infection with E. multilocularis, with the greatest Col1 level (280.26 ng/mL ± 23.04 ng/mL) seen 6 months post-infection and the highest α-SMA level (33.68 ng/mL ± 4.45 ng/mL) detected 8 months post-infection, respectively. Conclusions Persistent E. multilocularis infections promote hepatic stellate cell proliferation, induce an increase in mouse serum Col1 and α-SMA levels, and cause elevated deposition of collagen fibers in mice livers. The infective stage of E. multilocularis is a critical period for inducing hepatic fibrosis of alveolar echinococcosis.
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Objective@#The purpose of this study was to investigate the effect of different concentrations of exosomes (Exos) secreted from dental folic cells (DFCs) preconditioned with lipopolysaccharide (LPS) on the osteogenic differentiation ability of periodontal cells in periodontitis (p-PDLCs) in patients to provide a basis for the prevention and treatment of periodontal disease.@*Method @#Tissue block and enzyme digestion methods were used to culture DFCs and p-PDLCs. Exosomes were isolated from 250 ng/mL LPS-preconditioned DFCs 24 h later. The characteristics of exosomes were detected by transmission electron microscopy, particle size analysis and Western blotting. The effects of 10 μg/mL and 100 μg/mL exosomes on the osteogenic differentiation of p-PDLCs were detected by RT-PCR and Alizarin red staining.@*Results @# LPS-pretreated DFC-derived exosomes (L-Exos) are vesicle-like structures with a size between 30-100 nm that positively express CD63 and Alix. Compared with the control group, exosomes significantly upregulated Periostin, Col Ⅰ, and Col Ⅲ expression at 100 μg/mL (P < 0.05), while TGF- β1 was significantly upregulated at 10 μg/mL (P < 0.01). At 7 days after osteogenic induction, mineralized nodules were significantly more abundant in the exosome group than in the control group (P < 0.01), and the results were better at a concentration of 100 μg/mL (P < 0.01). @*Conclusion@# 100 μg/mL L-Exos are better than 10 μg/mL L-Exos in enhancing the osteogenic differentiation ability of p-PDLCs.
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Introducción: Las plaquetas contribuyen a la hemostasia y la interrupción heredada o adquirida; en sus procesos bioquímicos pueden alterar la función plaquetaria. Estos trastornos de agregación se han asociado a enfermedades genéticas con afectación del tejido conectivo como el síndrome Ehlers-Danlos, cuyo diagnóstico diferencial con el espectro de hipermovilidad articular resulta difícil clínica y molecularmente. Estas entidades con afectación en las fibras colágenas y diferente repercusión clínica precisan diferenciales en su diagnóstico clínico. Métodos: Se revisaron 353 historias clínicas de pacientes atendidos en el Servicio de Genética del Hospital Pediátrico William Soler desde septiembre del 2009 al 2012, con diagnóstico de hipermovilidad articular por criterios de Beighton y de Ehlers-Danlos según Villefranche (1997). Se incluyó a los pacientes de 5-18 años con resultados documentados del estudio de agregación plaquetaria, valorados por especialistas en hematología. Resultados: Se encontraron trastornos de agregación plaquetaria en 79 de 86 pacientes (92 por ciento). En 7 casos con hipermovilidad de 65 con este diagnóstico (10 por ciento), los resultados fueron negativos. Los 21 con síndrome Ehlers-Danlos tuvieron afectaciones con los fosfolípidos plaquetarios. La hipermovilidad articular estuvo asociada a la combinación difosfato de adenosina (ADP)-epinefrina y el Ehlers-Danlos a la combinación ADP-epinefrina-colágeno-fosfolípidos. Conclusiones: Los pacientes con hipermovilidad articular mostraron asociación a defectos de liberación de gránulos con agonistas como el ADP-epinefrina y los Ehlers-Danlos con la disponibilidad de los fosfolípidos, relacionados con el cambio de forma plaquetaria. Este resultado puede ser una herramienta para conocer el endofenotipo funcional plaquetario como elemento diferencial en los trastornos de la fibra colágena(AU)
Introduction: Platelets contribute to hemostasis and inherited or acquired interruption; in its biochemical processes it can alter platelet function. These aggregation disorders have been associated with genetic diseases with connective tissue involvement such as Ehlers-Danlos syndrome, whose differential diagnosis with the spectrum of joint hypermobility is clinically and molecularly difficult. These entities with involvement of the collagen fibers and different clinical repercussions require differentials in their clinical diagnosis. Methods: 353 medical records of patients attended in the Genetics service of the William Soler Pediatric Hospital from September 2009 to 2012, with a diagnosis of joint hypermobility by Beighton and Ehlers-Danlos criteria according to Villefranche (1997) were reviewed. Patients aged 5-18 years were included with documented results of the platelet aggregation study, assessed by specialists in hematology. Results: Platelet aggregation disorders were found in 79 of 86 patients (92 percent). In 7 cases with hypermobility of 65 with this diagnosis (10 percent), the results were negative. The 21 with Ehlers-Danlos syndrome had affectations with platelet phospholipids. Joint hypermobility was associated with the combination adenosine diphosphate (ADP) -epinephrine and the Ehlers-Danlos with the combination ADP-epinephrine-collagen-phospholipids. Conclusions: Patients with joint hypermobility showed an association to granule release defects with agonists such as ADP-epinephrine and Ehlers-Danlos with the availability of phospholipids, related to platelet shape change. This result can be a tool to know the platelet functional endophenotype as a differential element in collagen fiber disorders(AU)
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Humans , Platelet Aggregation/physiology , Ehlers-Danlos Syndrome/diagnosis , Endophenotypes/analysis , Genetic Diseases, InbornABSTRACT
Objective@#To investigate the effect of low level laser on osteoclast and collagen fiber remodeling during the process of tooth retention after tooth movement in rats and to provide the experimental basis for clinical application.@*Methods @# In total, 20 eight-week-old Wistar rats were selected to establish a mesial movement model of the maxillary first molar and then randomly divided into four groups after the appliance was removed. In total, 5 rats were included in each group, including baseline group (without force as blank control), control group (without any intervention after removing the force appliance), retention group (teeth were wrapped with orthodontic ligature wires that were screwed into hemp flower as fixed retention to maintain the space between the first molar and incisor after appliances were removed) and retention and low energy laser irradiation group (teeth were wrapped with the orthodontic ligature wires that were screwed into hemp flower as fixed retention and low energy laser irradiation was applied on days 0, 3, 6, 9 and 12 after appliance removal). Two weeks later, all the rats were sacrificed and the first molar tissue blocks of each group were collected. The distribution of osteoclasts and collagen fiber were studied by HE staining, TRAP staining and Masson staining to illustrate the process of alveolar bone and collagen fiber remodeling.@*Results @# Two weeks after appliances were removed, collagen fibers were deposited on both sides of the root in the baseline group, but no osteoclasts were observed in the distal side of the root. In the control group, collagen fibers on the two sides of the root were not obvious and osteoclasts were active on the distal side. In the retention group, collagen fibers were obvious on the two sides of the root and the osteoclasts on the distal side were less active than the control group. Regarding the retention and low energy laser irradiation group, collagen fibers were significantly obvious and osteoclasts were not seen. The difference was statistically significant between the retention and low energy laser irradiation group and the other three groups (P＜0.05). @*Conclusion@#These results suggest that fixed retention with simultaneous low level laser can effectively promote the synthesis of collagen fibers and inhibit the activity of osteoclasts during the process of tooth retention after movement, thus reducing the possibility of molar recurrence.
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Tumor invasion and metastasis are the main factors leading to poor prognosis of cancer patients.In recent years, studies have found that collagen fiber remodeling in extracellular matrix(ECM) can promote tumor invasion and metastasis . Lysine hydroxylase 2(PLOD2) is the only lysine hydroxylase that changes the pattern of collagen fiber cross-linking and remodeling. It is highly expressed in many tumors and is closely related to tumor invasion and metastasis,Therefore, in-depth study of the role and mechanism of PLOD2 in tumor metastasis is of great scientific value for judging tumor prognosis and preventing tumor invasion and metastasis.This article reviews the recent advances in the role and potential mechanisms of PLOD2 in tumor invasion and metastasis.
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The mechanical properties of the aorta tissue is not only important for maintaining the cardiovascular health, but also is closely related to the development of cardiovascular diseases. There are obvious differences between the ventral and dorsal tissues of the descending aorta. However, the cause of the difference is still unclear. In this study, a biaxial tensile approach was used to determine the parameters of porcine descending aorta by analyzing the stress-strain curves. The strain energy functions Gasser-Ogden-Holzapfel was adopted to characterize the orthotropic parameters of mechanical properties. Elastic Van Gieson (EVG) and Sirius red stain were used to observe the microarchitecture of elastic and collagen fibers, respectively. Our results showed that the tissue of descending aorta had more orthotropic and higher elastic modulus in the dorsal region compared to the ventral region in the circumferential direction. No significant difference was found in hyperelastic constitutive parameters between the dorsal and ventral regions, but the angle of collagen fiber was smaller than 0.785 rad (45°) in both dorsal and ventral regions. The arrangement of fiber was inclined to be circumferential. EVG and Sirius red stain showed that in outer-middle membrane of the descending aorta, the density of elastic fibrous layer of the ventral region was higher than that of the dorsal region; the amount of collagen fibers in dorsal region was more than that of the ventral region. The results suggested that the difference of mechanical properties between the dorsal and ventral tissues in the descending aorta was related to the microstructure of the outer membrane of the aorta. In the relatively small strain range, the difference in mechanical properties between the ventral and dorsal tissues of the descending aorta can be ignored; when the strain is higher, it needs to be treated differently. The results of this study provide data for the etiology of arterial disease (such as arterial dissection) and the design of artificial blood vessel.
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Animals , Aorta, Thoracic , Physiology , Biomechanical Phenomena , Collagen , Elastic Modulus , Stress, Mechanical , SwineABSTRACT
Objective To study the mechanical properties of porcine descending aorta. Methods The porcine descending aortas were divided into 5 groups by the distance from the heart, and tissues in each group were subdivided into ventral-quadrant part and lateral-quadrant part. Stress-stretch curves were obtained by using uniaxial tension test. The moduli of elastic and collagen fiber and collagen fiber recruitment parameter of tissues in 5 groups (Position 1-5) were first analyzed by a classical mathematical model. Then the mechanical differences between tissues of ventral quadrant and lateral quadrant were compared. Results The modulus of circumferential collagen fibers increased gradually away from the heart. The modulus of circumferential elastic fibers had the same trend except for tissues at Position 5 (the most distal one). The elastic fibers modulus of tissues decreased at Position 5. At the most distal position, the circumferential and axial elastic fiber modulus of the lateral quadrant was lower than that of ventral quadrant by 19% and 33%, respectively. The axial and the elastic fiber modulus of the ventral quadrant was similar with that of tissues at Position 4 and 5. For the whole descending aorta, the circumferential collagen fiber modulus of the lateral quadrant was higher than that of ventral quadrant by 26% and the circumferential elastic fiber modulus of the lateral quadrant was higher than that of ventral quadrant by 16% at the proximal 4 positions. Conclusions The circumferential mechanical properties of porcine descending aorta were related with regions. The ventral quadrant of the most distal aorta showed abnormally soft trend. The research findings can be used to better understand the mechanism of aorta and improve the spatial accuracy of computer models.
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The goal of this study was to determine the characteristics of the horizontal cervical wrinkle and to investigate histological feature, especially with respect to elastin and collagen fiber. Histologic sample were harvested from two fresh adult cadavers where the cervical wrinkle is in the neck. The tissue sections were stained with hematoxylin and eosin (HE) or Masson's Trichrome. In sections of neck skin, keratinization was observed in the epidermis, and many collagen fibers were observed in the dermis layer as in other skin. Specifically, a lot of short and curly elastic fiber were observed between the collagen fibers in the dermis. These elastic fibers were not stained with eosin and observed in gray. This long ligament-like structures were observed in the dermis. The ligament-like structures were stained with dark red by trichrome. These results indicate that these ligament-like structures are neither typical ligament nor typical smooth muscles. The results obtained from present study showed a ligamentous structure originating from the fascial layer (platysma muscle or investing layer). The results may help to understand the reasons about the formation of horizontal cervical wrinkle.
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Adult , Humans , Aging , Cadaver , Collagen , Dermis , Elastic Tissue , Elastin , Eosine Yellowish-(YS) , Epidermis , Hematoxylin , Ligaments , Muscle, Smooth , Neck , SkinABSTRACT
Objective:To study the effects of Ti-TiO2 nanotubes with different diameters on the proliferation,stretching and collagen secretion of fibroblasts.Methods:TiO2 nanotubes formed at 1,5,10 and 20 V potentials served as the experimental samples and polished pure titanium served as the control.Fibroblasts was cultivated on the surface of the various samples.MTT assay was used to examine the cell proliferation.The surface morphology of the cells was observed with SEM.Collagen secrection was tested by sirius red/bitter acid staining.Results:The nanotubes prepared by 1,5,10 and 20 V were with the diameter of 15,30,50 and 100 nm respectively.At day 1,3 and 5,the cell proliferation on polished pure titanium surface was more than that on the nanotubes surfaces at the same time;at day 5,cell proliferation on 100 nm nanotubes was significantly more than that on the other nanotube surfaces (P ＜ 0.01).At day 3,fibroblasts at polished pure titanium surface stretched as typical long spindle form,while with obvious pseudopodium at nanotube surfaces.The collagen secretion of fibroblasts was highest at 100 nm nanotubes (P ＜ 0.01).Conclusion:100 nm nanotubes may have minimal negative effect on fibroblast proliferation and the greatest positive effect on the collagen secretion.
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“Tendon gel” secreted from a parent tendon is regenerated for tendon repair by applying tension. However, the details of the tensile stimulus have not been clarified. This study aimed to evaluate an appropriate tensile stimulus mode and the optimal timing of applying tension to promote tendon gel regeneration. Tendon gel was prepared using a film model method in mice and was preserved in vivo for 3, 5, and 10 days. Unlike tendon gel on day 3 or day 5, a fibrous structure developed in the tendon gel on day 10 when tension was applied. Infrared spectroscopy revealed that characteristic peaks appearing for the tendon gel on days 3 and 5 disappeared on day 10. Disappearance of the peaks indicated maturity of the tendon gel, and it showed the optimal timing for tension application to the tendon gel. The effect of tensile load on tendon gel preserved for 10 days was investigated using a tensile test, a creep test, or a cycle test. In the tensile test, tendon gel was elongated into a thin cord of collagen fibers with an increase in stress, and the maximum diameter of the collagen fiber was approximately 50 times larger than that in the normal Achilles tendon of mice. The results suggest that the diameter of the oriented collagen fiber is controllable by adjusting the applied load and the time in mature tendon gel.
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Animals , Humans , Mice , Achilles Tendon , Collagen , Methods , Parents , Regeneration , Spectrum Analysis , TendonsABSTRACT
BACKGROUND: Papular elastorrhexis (PE), eruptive collagenoma (EC), and nevus anelasticus (NA) are described as multiple small papules with decrease, fragmentation, or lack of dermal elastic fibers. These diseases are suggested to be the same entity. The change of collagen fibers in the conditions has not been addressed to date. OBJECTIVE: We compared the clinical features of the 3 diseases and investigated changes in the collagen fibers involved. METHODS: Twenty-four cases of PE, 12 cases of EC, and 2 cases of NA found in PubMed and the Korean database were reviewed. Changes in dermal collagen fibers in 10 cases with histological figures were investigated. RESULTS: There were significant similarities between the 3 entities in terms of their clinical features. Four patients with PE and 2 with EC with fine, dense collagen fibers were women who had multiple white to hypopigmented, slightly indurated to firm, millimeter-size papules on the trunk and/or extremities that progressed gradually after developing in the patients' first to third decades. CONCLUSION: The 3 conditions are the same clinical entity in our opinion; such cases with fine, dense collagen manifest typical features.
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Female , Humans , Collagen , Elastic Tissue , Extremities , NevusABSTRACT
BACKGROUND: Papular elastorrhexis (PE), eruptive collagenoma (EC), and nevus anelasticus (NA) are described as multiple small papules with decrease, fragmentation, or lack of dermal elastic fibers. These diseases are suggested to be the same entity. The change of collagen fibers in the conditions has not been addressed to date. OBJECTIVE: We compared the clinical features of the 3 diseases and investigated changes in the collagen fibers involved. METHODS: Twenty-four cases of PE, 12 cases of EC, and 2 cases of NA found in PubMed and the Korean database were reviewed. Changes in dermal collagen fibers in 10 cases with histological figures were investigated. RESULTS: There were significant similarities between the 3 entities in terms of their clinical features. Four patients with PE and 2 with EC with fine, dense collagen fibers were women who had multiple white to hypopigmented, slightly indurated to firm, millimeter-size papules on the trunk and/or extremities that progressed gradually after developing in the patients' first to third decades. CONCLUSION: The 3 conditions are the same clinical entity in our opinion; such cases with fine, dense collagen manifest typical features.
Subject(s)
Female , Humans , Collagen , Elastic Tissue , Extremities , NevusABSTRACT
Objective: To observe the sequential changes of collagen fibers in rats with diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC), so as to provide a reference for pathogenesis research of HCC. Methods: Fifty male Wistar rats, weighing 100-120 g, were randomly divided into normal group and HCC model group. The model group was intraperitoneally administered with 50 mg/kg DEN (0.1 mL), twice a week for 4 weeks, then once a week for another 10 weeks. The control group was given normal saline (0.1 mL) in the same manner. Finally the rats were sacrificed; the normal and diseased liver tissues were observed by H-E, Masson and argyrophilic fiber staining. The expression of collagen type I and type III mRNA was detected by fluorogenic quantitative PCR; the expression of matrix metalloproteinase (MMP) was examined by gelatinases spectrometry. Results: Cirrhosiswas found in rats 5 weeks after treatment with DEN and HCC was induced 14 weeks after DEN treatment; collagen deposition in liver tissues increased in a progressive manner, and the collagen contents in the HCC tissues was greatly less than that in the adjacent tissues, showing a decreasing trend. The contents of MMP-2 and MMP-9 in the HCC and adjacent tissues had opposite changes compared with collagen. Conclusion: Collagen deposition in cirrhosis liver tissue is increased during the process of DEN-induced HCC, but it is decreased in HCC tissues in a progressive manner, which indicates that collagen might be degraded during the progression from cirrhosis to HCC.
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Background Fungal corneal ulcer is a visual-threatening eye disease,and drug therapy has a limiting efficacy.Corneal transplantation or eye enucleation sometimes is necessary to the severe patients.Corneal collagen cross-linking (CXL) is an effective method for some corneal diseases,but the study on CXL for fungal corneal ulcer is lack.Objective This study was to evaluate the clinical effectiveness and safety CXL for fungal corneal ulcer.Methods Fifteen 8-week-old healthy New Zealand white rabbits were used in this study and other 5 rabbits served as normal controls.Fungal corneal ulcer models were established in the right eyes of other 10 rabbits by infecting sickle bacteria liquid after corneal scratching and removing corneal epithelium,then decellularized ostrich corneal patch covered the defected cornea.The models were randomly divided into the non-treatment group and the CXL treatment group.Corneal lesions were examined under the slit lamp microscope every day,and cornea was pictured by laser scanning confocal microscope on the 3rd,7th,14th,21st and 28th day individually after CXL.All rabbits were sacrificed and corneal tissues were obtained 4 weeks after treatment,and the collagen fiber diameter and fibrocytes were observed under the scanning electron microscope.Results Fungal corneal ulcer models were successfully established by corneal scratching and decellularized ostrich cornea covering.The gray ulcer lesions and hypbae like bean pod were seen by slit lamp microscope and laser scanning confocal microscope 3 days after modeling.Corneal ulcer deepened and expanded 1 week later,and there were a large number of spore and hyphae criss-crossing as short rod in shallow stroma.Inflammatory cells were observed in corneal endothelial cells and ocular anterior chamber.In the CXL treatment group,the range of corneal epithelial deficiency was less than that in the nontreatment group on the 3rd,7th,14th,and 21st (all at P＜ 0.05).The diameters of collagen fibers were (24.6± 1.8) nm,(24.9 ± 1.9) nm and (43.0 ± 7.4) nm in the normal control group,non-treatment group and CXL treatment group,showing a significant difference among the 3 groups (F =27.05,P =0.00),and the collagen diameters were thicker in the CXL treatment group than those in the normal control group and non-treatment group (t =5.40,-5.30,both at P＜0.05),and fibrocytes were seen among the collagen fibers.No significant difference was found in the collagen diameters between the non-treatment group and normal control group,and the fibrocytes were less in the non-treatment group.Conclusions CXL therapy can treat fungal corneal ulcer by enhancing collagen,promoting fibrocytes proliferation,suppressing fungus and inflammatory response and accelerating tissue repair.
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Objective To explore a simple and suitable method for stretch preparation of subcutaneous loose connective tissue in rabbits . Methods Three rabbits were continuously performed with 10-12ml of trypan blue saline solution(10g /L) by intraperitoneal injection once a day .The subcutaneous loose connective tissue was collected for stretch prepararation on the fourth day and fixed with a formalin-alcohol salution for 6 hours.The tissue was put into aldehyde fuchsin, nuclear fast red and eosin for staining .Washing with tap water was taken after every step .Finally, conventional dehydration , clearing and mounting were applied .Results Macrophages were irregular in sharp and distributed among fibers.Many engulfed blue granules were observed within the cytoplasms .The nuclei were stained in red .The color of elastic fibers showed purple or blue-violet at the time point of aldehyde fuchsin staining between 30-40 minutes.The color of collagen fibers was light red .Conclusion The present method is simple , stable and reliable for stretch preparation of subcutaneous loose connective tissue in rabbits .