In man the epiglottis is a thin lamella of yellow elastic cartilage. The upper part is free and is known asleaf and lower part participates in the formation of the anterior wall of the vestibule of the larynx. Theipithelial covering extends forwards onto the base of the tongue over the medial glossoepiglottic folds. The sidesof epiglottis are connected with the cartilages of Wrisberg and arytenoid cartilage by the aryepiglottic fold. Inview of these anatomical complexities, the function and physiology of the epiglottis have been debated sinceMagendi(1815), who proposed the theory that the epiglottis acts as a flap valve to prevent food entering thewindpipe, and who found that he could remove the free part of the epiglottis in dog without spoiling the dog.Follwoing the introduction of laryngoscopy(Garcia, 1815; Liston, 1840; Czermark, 1861) and modern cineradiographicequipments in 1950's, the anatomy and physiology of epiglottis has become much clearrer. Age as it is seen on thelateral x-ray of the neck. In the present study we have made an attempt to systematically analyze aging changes ofthe epiglottis in the lateral x-ray of the neck in 245 healthy adults. The age ranged from 16 to 65 years old.Based on our observation the epiglottis was classified into type A, B, and C according to their curvatures. Thus,type A represented those with posterior curvature, type B those with straight epiglottis and type C anteriorcurvature. Type C was sudivided into I, II and III according to the degree of curvature. Thus, type C-I, C-II andC-III represented mild, moderated and marked anterior curvature, respectively. Type A epiglottis was found in thesecond, third and fourth decades and type C-III in the older age group. Type A was least comon and type C mostprevalent. It seems that the epiglottis inclines anteriorly with backward curvature with age (p<0.0001).
Adult ; Aging ; Animals ; Arytenoid Cartilage ; Cartilage ; Dogs ; Elastic Cartilage ; Epiglottis ; Humans ; Larynx ; Neck ; Physiology ; Tongue

Osteogenesis and angiogenesis are two closely correlated processes during bone growth, development, remodelling and repair.Vascular endothelial growth factor (VEGF) is an essential mediator during the process of angiogenesis. Based on an extensive literature search, which was carried out using the PubMed database and the keywords of osteogenesis, VEGF, endochondral ossification and intramembranous ossification, this manuscript reviews the role of VEGF in ossification, with emphasis on its effect in endochondral and intramembranous ossification. Osteogenesis and angiogenesis are closely correlated processes. VEGF acts as an essential mediator during these processes. It not only functions in bone angiogenesis but also in various aspects of bone development.
Animals ; Bone Remodeling ; physiology ; Bone and Bones ; cytology ; physiology ; Calcification, Physiologic ; physiology ; Cartilage ; cytology ; physiology ; Humans ; Neovascularization, Physiologic ; physiology ; Osteoclasts ; physiology ; Osteogenesis ; physiology ; Vascular Endothelial Growth Factor A ; physiology

OBJECTIVEUsing MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage.

METHODSTwenty-four male Beagle dogs were randomly divided into a subchondral bone defect group (n = 12) and a bone cement group (n = 12). Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side. The T2 value for articular cartilage at the medial tibial plateau was measured at postoperative weeks 4, 8, 16, and 24. The articular cartilage specimens were stained with hematoxylin and eosin, and evaluated using the Mankin score.

RESULTSThere was a statistically significant difference (P < 0.05) in Mankin score between the bone defect group and the cement group at postoperative weeks 16 and 24. There was a statistically significant difference in the T2 values between the bone defect group and its sham group (P < 0.05) from week 8, and between the cement group and its sham group (P < 0.05) from week 16. There was significant difference in T2 values between the two experimental groups at postoperative week 24 (P < 0.01). The T2 value for articular cartilage was positively correlated with the Mankin score (ρ = 0.758, P < 0.01).

CONCLUSIONStructural changes in subchondral bone can lead to degeneration of the adjacent articular cartilage. Defects in subchondral bone cause more severe degeneration of cartilage than subchondral bone filled with cement. The T2 value for articular cartilage increases with the extent of degeneration. MR T2-mapping images and the T2 value for articular cartilage can indicate earlycartilage degeneration.

Animals ; Bone Cements ; Bone and Bones ; physiology ; Cartilage, Articular ; physiology ; Dogs ; Male

Culture media supplemented with animal serum e.g. fetal bovine serum; FBS is commonly used for human culture expansion. However, for clinical application, FBS is restricted as its carry a risk of viral or prion transmission. Engineering autologous cartilage with autologous human serum supplementation is seen as a better solution to reduce the risk of transmitting infectious diseases and immune rejection during cartilage transplantation. The purpose of this study is to establish and compare the effects of 10% autologous human serum (AHS) and 10% FBS on the growth of chondrocytes and the formation of tissue engineered human articular cartilage.
Cartilage, Articular/growth & development ; Cartilage, Articular/*transplantation ; Cell Count ; Cell Division/physiology ; Chondrocytes/*cytology ; Culture Media ; *Serum ; *Tissue Engineering

Treatment of articular cartilage lesions remains a clinical challenge. The uses of prosthetic joint replace allograft and/or autograft transplant carry a risk of complications due to infection, loosening of its component, immunological rejection and morbidity at the donor site. There has been an increasing interest in the management of cartilage damages, owing to the introduction of new therapeutic options. Tissue engineering as a method for tissue restoration begins to provide a potential alternative therapy for autologous grafts transplantations. We aimed to evaluate how well a tissue engineered neocartilage implant, consist of human articular chondrocytes cultured with the presence of autologous serum and mixed in a fresh fibrin derived from patient, would perform in subcutaneous implantation in athymic mice.
Biomechanics ; Cartilage, Articular/injuries ; Cartilage, Articular/physiology ; Cartilage, Articular/*transplantation ; Chondrocytes/*cytology ; Culture Media ; Mice, Nude ; *Orthopedic Procedures ; Serum ; *Tissue Engineering

More and more scholars agreed with the viewpoint that osteonecrosis relates with the metabolic activity of chondrocyte. Moreover,the activation of beta-catenin among Wnt/beta-catenin signal pathway can promote differentiation of chondrocyte and can promote differentiated cell death. So it suggests that this signal pathway should have an effect to occurrence and development of osteonecrosis by regulating the metabolic activity of chondrocyte. Through the establishment of conditional beta-catenin knockout mice,it is helpful to understand the pathogenesis of Wnt/beta-catenin signal pathway regulating cartilage metabolism. By the way we can understand the pathogenesis of osteonecrosis and give a targeted treatment to the disease. This article reviewed the relationship of three aspects of Wnt/beta-catenin signal pathway, cartilage metabolism and osteonecrosis.
Animals ; Cartilage ; metabolism ; Humans ; Mice ; Osteonecrosis ; metabolism ; Signal Transduction ; physiology ; Wnt Signaling Pathway ; physiology ; beta Catenin ; physiology

gp130-mediated signaling is involved in both chondrogenesis and osteogenesis, but its direct role in the formation of embryonic Meckel's cartilage and associated mandibular development has not yet been elucidated. In this study, we examined the influence of gp130 ablation on the developing mandibular Meckel's cartilage by evaluating the morphological and histological changes as well as the gene expression patterns in developing embryonic gp130-/- mice. The ablation of the gp130 gene showed no change in region-specific collagen mRNA expression except for a slight delay in its expression but caused shortened embryonic Meckel's cartilage, delayed hypertrophic chondrocyte maturation and subsequent bony replacement with characteristic bending of the intramandibular Meckel's cartilage. The bending of Meckel's cartilage led to a narrow mandibular arch at the rostral area with poor cortical plate formation. These findings indicate that gp130-mediated signaling is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development.
Animals ; Body Patterning ; Cartilage/embryology/metabolism/*physiology ; Collagen ; Cytokine Receptor gp130/genetics/*physiology ; Mandible/embryology/metabolism/*physiology ; Mice ; Mice, Knockout

BACKGROUNDAcute effects of physical exercise on the deformational behavior of knee articular cartilage and changes in cartilage volume are definite. However, conclusive effects of different exercises on the loss of articular cartilage volume have not been proved. In this parallel-group randomized controlled trial, we tested whether 12 weeks of swimming, powerstriding, cycling, and running exercises would decrease the cartilage volume significantly and whether there would be a difference in the loss of cartilage volume after different types of exercises.

METHODSFrom October 2012 to January 2013 we evaluated 120 healthy volunteer students in Biomechanics Laboratory of Tongji University. Body mass index (BMI), right lower limb strength, and right knee cartilage magnetic resonance imaging (MRI) were obtained before exercise. MRI were conducted in East Hospital. The study was approved by Tongji University Ethical Committee, all subjects were randomly assigned to the running, powerstriding, cycling, swimming, and control groups by a drawing of lots. Each group contained 24 samples. At the end of 12 weeks of regular exercises, the same measurement procedures were applied. Cartilage volume was calculated with OSIRIS software based on the quantitative-MRI. Pre- and post-exercise comparisons were carried out using paired t-tests and one-way analysis of variance (ANOVA) was used to compare differences of cartilage volume loss between groups with Student-Newman-Keuls procedure for multiple comparisons.

RESULTSRunning, cycling, and swimming groups resulted in a significant decrease in BMI. The quadriceps peak torque increased significantly in the swimming and cycling groups. Total cartilage volume significantly decreased in the running and cycling groups after 12 weeks of training, without any significant change in the nonimpact swimming, low-impact powerstriding, and control groups. Loss of total cartilage volume in the running and cycling groups were 2.21% (3.03) and 1.50% (0.42).

CONCLUSIONSTwelve weeks of regular physical exercises (i.e., running and cycling) decrease the total knee cartilage volume. Swimming and powerstriding are recommended for the healthy youth. This finding suggests that articular cartilage has the functional adaptation for exercises, and some sports could be the risk factors for the initiation of osteoarthritis (OA) in young healthy adults.

Adolescent ; Adult ; Cartilage, Articular ; metabolism ; physiology ; Exercise ; physiology ; Female ; Humans ; Knee Joint ; metabolism ; physiology ; Male ; Young Adult

After the articular cartilage injury, the metabolic level is increased during the progressive degeneration, the chondrocytes secrete a variety of inflammatory factors, and the original cell phenotype is gradually changed. For a long time, a large number of researchers have done a lot of researches to promote anabolism of chondrocytes and to maintain the stability of chondrocyte phenotype. There are many molecular signaling pathways involved in the process of promoting cartilage repair. This review focuses on the key signaling molecules in articular cartilage repair, such as transforming growth factor-beta and bone morphogenetic protein, and reveals their roles in the process of cartilage injury and repair, so that researchers in related fields can understand the molecular mechanism of cartilage injury and repair widely and deeply. Based on this, they may find promising targets and biological methods for the treatment of cartilage injury.
Bone Morphogenetic Proteins ; physiology ; Cartilage, Articular ; growth & development ; injuries ; Chondrocytes ; physiology ; Humans ; Regeneration ; Signal Transduction ; Transforming Growth Factor beta ; physiology

Three-dimensional cell scaffolds play an important role in tissue engineering. They can modulate cell response and guide the regeneration of tissues. Injectable scaffolds can mimic the chemical and physical environments of natural extracellular matrix, and can be easily applied in clinic with the merits of minor or nonsurgical operations. Hence, special care should be given to the use of this kind of scaffolds in tissue engineering hydrogels, and composites with other fillers have been used as a basic component to construct the injectable scaffolds. Most of these injectable scaffolds are applied to repair bone and cartilage. Experimental results have development of the injectable scaffolds in recent years. The advantages and disadvantages are discussed with the development of the injectable scaffolds in recent years. The advantages and disadvantages are discussed with the suggestions for future development.
Absorbable Implants ; Biocompatible Materials ; Bone and Bones ; physiology ; Cartilage ; physiology ; Guided Tissue Regeneration ; Humans ; Hydrogels ; Tissue Engineering ; methods ; Tissue Scaffolds