Presence Of Hyaline Cartilage Research Articles

3D Bioprinted Integrated Osteochondral Scaffold-Mediated Repair of Articular Cartilage Defects in the Rabbit Knee

To demonstrate that a 3D-bioprinted integrated osteochondral scaffold can provide improved repair of articular cartilage defects in the rabbit knee compared to that reported for traditional tissue-engineering methods. Bone marrow mesenchymal stem cells were differentiated into osteoblasts and chondrocytes as seed cells and mixed with the corresponding bone and cartilage scaffold materials. An integrated osteochondral biphasic scaffold was fabricated via 3D-bioprinting technology through successive natural overlays of the printed material and used to repair full-thickness articular cartilage defects in the rabbit knee. Histological and biomechanical assessment of repaired tissue at 6 months post-transplantation showed almost complete repair of injured articular surfaces and presence of hyaline cartilage. A boundary existed between the transition and repair zones. The Wakitani histological score was 5.50 ± 2.07 points; maximum load was 183.11 ± 35.20 N. Repaired cartilage was integrated firmly with the subchondral bone and almost assimilated with surrounding cartilage and bone tissues. The 3D bioprinted integrated osteochondral scaffold achieved double bionic effects on the scaffold composition and structure, and it is expected to offer a new strategy for articular cartilage repair and regeneration.

Cartilage Regeneration in Preannealed Silk Elastin-Like Co-Recombinamers Injectable Hydrogel Embedded with Mature Chondrocytes in an Ex Vivo Culture Platform.

Tissue engineering for cartilage repair requires biomaterials that show rapid gelation and adequate mechanical properties. Although the use of hydrogel is the most promising biomaterial, it often lacks in rigidity and anchorage of cells when they are surrounded by synovial fluid while they are subjected to heavy loads. We developed and produced the Silk Elastin-Like co-Recombinamer (SELR), which contains both the physical interaction from elastin motifs and from silk motifs. In the first part of this work, we set up and optimized a preannealing treatment based on the evolution of silk motifs into β-sheet structures in order to fulfill the required mechanical properties of hydrogels for cartilage repair. The new preannealed SELRs (pA(EIS)2-(I5R)6) were characterized with the combination of several experimental techniques (CD, TEM, SEM, and rheology) to provide a deep insight into the material features. Finally, the regeneration properties of the pA(EIS)2-(I5R)6 hydrogel embedded with chondrocytes were evaluated. After 4 weeks of culturing in a standardized and representative ex vivo model, the biochemical and histological analysis revealed the production of glycosaminglycans and collagen. Moreover, the immunohistochemistry showed the absence of fibro-cartilage and the presence of hyaline cartilage. Hence, we conclude that the pA(EIS)2-(I5R)6 hydrogel presents improved mechanical properties while conserving the injectability, which leads to successful regeneration of hyaline cartilage in an ex vivo model.

Comparative efficacy of cartilage repair procedures in the knee: a network meta-analysis.

While numerous randomized controlled trials have compared surgical treatments for cartilage defects of the knee, the comparative efficacy of these treatments is still poorly understood. The goal of this network meta-analysis was to synthesize these randomized data into a comprehensive model allowing pairwise comparisons of all treatment options and treatment rankings based on multiple measures of efficacy. We hypothesized that advanced chondral procedures would have improved outcomes when compared to microfracture. The MEDLINE, COCHRANE and EMBASE databases were searched systematically up to January 2015. The primary outcome was re-operation measured at 2, 5 and 10years. Secondary outcomes included Tegner and Lysholm scores, the presence of hyaline cartilage on post-operative biopsy and graft hypertrophy. A random-effects network meta-analysis was performed, and the results are presented as odds ratios and mean differences with 95% CIs. We ranked the comparative effects of all treatments with surface under the cumulative ranking probabilities. Nineteen RCT from 15 separate cohorts including 855 patients were eligible for inclusion. No differences were seen in re-operation rates at 2years. At 5years osteochondral autografts (OC Auto) had a lower re-operation rate than microfracture (OR 0.03, 95% CI 0.00-0.49), and at 10years OC Auto had a lower re-operation rate than microfracture (OR 0.34, 95% CI 0.12-0.92), but a higher re-operation rate than second-generation ACI (OR 5.81, 95% CI 2.33-14.47). No significant differences in Tegner or Lysholm scores were seen at 2years. Functional outcome data at 5 and 10years were not available. Hyaline repair tissue was more common with OC Auto (OR 16.13, 95% CI 2.80-92.91) and 2nd generation ACI (OR 7.69, 95% CI 1.17-50) than microfracture, though the clinical significance of this is unknown. Second-generation ACI (OR 0.12, 95% CI 0.02-0.59) and MACI (OR 0.13, 95% CI 0.03-0.59) had significantly lower rates of graft hypertrophy than first-generation ACI. Second-generation ACI, OC Auto and MACI were the highest ranked treatments (in order) when all outcome measures were included. Microfracture and advanced cartilage repair techniques have similar re-operation rates and functional outcomes at 2years. However, advanced repair techniques provide higher-quality repair tissue and might afford lower re-operation rates at 5 and 10years. Meta-analysis studies, Level I.

Biometry of the heart of the fowl (Gallus gallus domesticus)

The biometrical observations on the heart of fowl (vencobb-400 strain) revealed that the average weight was 8.91 ± 0.25 g, the mean percentage ratio between the length of rostral and caudal borders was 54:46 and the circumference at the coronary groove was 6.92 ± 0.08 cm. The right and left longitudinal grooves anastomosed with each other 1.05 ± 0.09 cm above the apex of the heart on the right side. The distance between the termination of caudal venacava and the apex of the heart was less (3.38 ± 0.13 cm) than the distance between the latter and origin of pulmonary artery (3.83 ± 0.13 cm). The cardiac skeleton was characterized by the presence of hyaline cartilage. The rostrocaudal diameter of the base of heart was greater (3.12 ± 0.08 cm) than the transverse diameter (2.15 ± 0.09 cm). The cross-sectional area of common aorta (46.00 ± 3.03 mm2) was greater than the area of pulmonary artery (32.4 ± 2.16 mm2). The total area of two anterior aortae (8.47 mm2) was lesser than the area of caudal aorta (10.8 mm2). The moderator bands could not be seen in both the ventricles.

Histological evaluation of calcaneal tuberosity cartilage--A proposed donor site for osteochondral autologous transplant for talar dome osteochondral lesions.

Osteochondral Autologous Transplant (OATs) as a treatment option for Osteochondral lesions (OCLs) of the talar dome frequently uses the distal femur as the donor site which is associated with donor site morbidity in up to 50%. Some studies have described the presence of hyaline cartilage in the posterior superior calcaneal tuberosity. The aim of this study was to evaluate the posterior superior calcaneal tuberosity to determine if it can be a suitable donor site for OATs of the talus In this cadaveric study, we histologically evaluated 12 osteochondral plugs taken from the posterior superior calcaneal tuberosity and compared them to 12 osteochondral plugs taken from the talar dome. In the talar dome group, all samples had evidence of hyaline cartilage with varying degrees of GAG staining. The average hyaline cartilage thickness in the samples was 1.33 mm. There was no evidence of fibrocartilage, fibrous tissue or fatty tissue in this group. In contrast, the Calcaneal tuberosity samples had no evidence of hyaline cartilage. Fibrocartilage was noted in 3 samples only. We believe that the structural differences between the talus and calcanium grafts render the posterior superior clancaneal tuberosity an unsuitable donor site for OATs in the treatment of OCL of the talus.

The use of PLDLA/PCL-T scaffold to repair osteochondral defects in vivo

The physiological repair of osteochondral lesions requires the development of a scaffold that is compatible with the structure of the damaged tissue, cartilage and bone. The aim of this study was to evaluate the biological performance of a PLDLA/PCL-T (90/10) scaffold for repairing osteochondral defects in rabbits. Polymeric scaffolds containing saccharose (75% w/v) were obtained by solvent casting and then implanted in the medial knee condyles of 12 New Zealand rabbits after osteochondral damage with a trephine metallic drill (diameter: 3.3 mm) in both medial femoral condyles. Each rabbit received the same treatment, i.e., the polymeric scaffold was implanted on the right side while no material was implanted on the left side (control). Four and 12 weeks later histological examination revealed bone neoformation in the implant group, with the presence of hyaline cartilage and mesenchymal tissue. In contrast, the control group showed bone neoformation with necrosis, exacerbated superficial fibrosis, inflammation and cracks in the neoformed tissue. These findings indicate that the PLDLA/PCL-T scaffold was biocompatible and protected the condyles by stabilizing the lesion and allowing subchondral bone tissue and hyaline cartilage formation.

Cytological and Histopathology Features of Meibomian Adenocarcinoma in a Dog Terrier Breed

In March 2012, an 8-year-old neutered terrier which was admitted to the Veterinary Surgery Clinics of Faculty of Veterinary Medicine, University of Tehran, Iran. The signalment (i.e. description of appearance of the animals such as sex, breed, age, etc) and anatomical repartition were summarized and focused on pathomorphological explanation. Macroscopically, the mass was gray-reddish and arising from the right lower eyelid with local spread to the upper eyelid and covering the entire globe was observed. Following sedation and local anesthesia, the tumor and globe were expulsed with Cryosurgery. Cytological smears indicated large number of malignant meibomian cells occurring either individually or in clusters also cytology indicated high cellularity and contained small clusters of polygonal to elongated tumor cells. Microscopically, the mass was composed of lobules of various sizes separated with a septum of connective tissue which included with poorly differentiated (grade III), nuclear pleomorphism and polygonal sebaceous cells, also with acinular and sheet-like architecture, the findings are consistent with minimal mitotic activity, extensive invasion, low grade and the presence of hyaline cartilage. Finally, histopathological examination revealed an MAC.

Efficacy of perichondrium and a trabecular demineralized bone matrix for generating cartilage.

A pedicled auricular perichondrial flap wrapped around trabecular demineralized bovine bone matrix can generate an autologous cartilage graft. In earlier experimental studies, it was demonstrated that this graft could be used for nasal and cricoid reconstruction. It was assumed that the vascularization of the perichondrial flap was obligatory, but it was never proven that the flap should be pedicled. Moreover, for clinical use, the dimensions of the auricle would set restrictions to the size of the graft generated. Therefore, the possibility to generate cartilage with a composite graft of a free perichondrial flap wrapped around demineralized bovine bone matrix, by using young New Zealand White rabbits, was studied. This composite graft was implanted at poorly (subcutaneously in the abdominal wall; n = 12), fairly (subcutaneously in the pinna; n = 12), and well-vascularized sites (quadriceps muscle; n = 12). As a control, trabecular demineralized bovine bone matrix was implanted without perichondrial cover. Half of these grafts (n = 6) were harvested after 3 weeks, and the remaining grafts (n = 6) after 6 weeks of implantation. In histologic sections of these grafts, the incidence of cartilage formation was scored. Furthermore, the amount of newly formed cartilage was calculated by computerized histomorphometry. Trabecular demineralized bovine bone matrix without perichondrial cover demonstrated early resorption; no cartilage or bone was formed. In demineralized bovine bone matrix wrapped in perichondrium, early cartilage formed after 3 weeks at well- and fairly vascularized sites. No cartilage could be detected in grafts placed at a poorly vascularized site after 3 weeks; minimal cartilage formed after 6 weeks. In summary, the highest incidence of cartilage formed when trabecular demineralized bovine bone matrix was wrapped either in a pedicled auricular perichondrial flap or in a free perichondrial flap, which was placed at a well-vascularized site. Second, a significantly higher percentage of the total area of the graft was cartilaginized at well-vascularized sites after 3 weeks. The newly generated cartilage contained collagen type II and proteoglycans with hyaluronic acid binding regions, whereas collagen type I was absent, indicating the presence of hyaline cartilage. This study demonstrates that new cartilage suitable for a graft can be generated by free perichondrial flaps, provided that the site of implantation is well vascularized. Consequently, the size of such a graft is no longer limited to the dimensions of the auricle.

A gross and microscopic study of the respiratory anatomy of the Antarctic Weddell seal, Leptonychotes weddelli.

Four species of Phocidae, or true seals, inhabit the waters surrounding the Antarctic continent. These animals are thought to have different diving capabilities. The Weddell seal, Leptonychotes weddelli, is known to be capable of attaining depths up to 600 meters. The respiratiory system of the Weddell seal shows the usual adaptations to an aquatic environment characteristic of other marine. These include lungs that undergo compression acollapse at depths greater than 70 meters; hyaline cartilage in the tracheo-bronchial tree as far as the terminal bronchioles; and large amounts of smooth muscle surrounding the distal-most bronchioles. The collapsible lungs provide a mechanism by which air is forced from the alveoli adjacent to the pulmonary capillary beds thereby preventing the absorption of nitrogen gas into the bloodsteam. The presence of hyaline cartilage throughout most of the tracheo-bronchial tree increases the effective dead air space that accommodates most of the air forced from the collapsed lungs. The smooth muscle surrounding the respiratory bronchioles prevents their collapse while under the pressures of a deep dive. Collapse of the respiratory bronchioles not supported by cartilage would trap air in the lung alveoli during a dive. In addition, large- sac-like "diverticulae" are found in the submucosa throughout the tracheo-bronchial tree. These diverticulae, which open directly into the lumen of the tree, appear to be modified glands whose cells, in most cases, do not appear to be specialized for secretory function. They are most numerous in the more distal bronchi and terminal bronchioles where they are situated on both the luminal and adventitial sides of the hyaline cartilage supporting the walls of the air passages. Diverticulae are not found in the respiratory bronchioles or in the respiratory portion of the lungs.