Congenital fusion of cervical vertebrae: a review on embryological etiology

Congenital fusion of cervical vertebrae is a rare anomaly. In this condition, two fused vertebrae appear structurally and functionally as one. This anomaly may be symptomatic or asymptomatic. Myelopathy, limitation in neck movement, muscular atrophy and regional sensory loss are examples of probable morbidity associated with this anomaly. Combination of genetic and environmental factors are involved in pathogenesis of this anomaly. Malformation of notochord, poor performance of retinoids, decreased local blood supply of spine and alteration in genes expression, especially members of Hox and Pax family genes are some of the proposed reasons of congenital fusion of cervical vertebrae. Diagnosis of this congenital anomaly in childhood seems to have an important role in prevention of probable secondary disorders in adulthood. We offer to clinicians that after performing careful physical tests and noticing the presence of signs and symptoms that mentioned in this paper, if a patient suspected to have congenital fusion of cervical vertebrae, genetic tests ought to be performed

Study of carbon nanotubes effects on the chondrogenesis of human adipose derived stem cells in alginate scaffold

Background: Osteoarthritis is one of the most common diseases in middle-aged populations in the World and could become the fourth principal cause of disability by the year 2020. One of the critical properties for cartilage tissue engineering [TE] is the ability of scaffolds to closely mimic the extracellular matrix and bond to the host tissue. Therefore, TE has been presented as a technique to introduce the best combination of cells and biomaterial scaffold and to stimulate growth factors to produce a cartilage tissue resembling natural articular cartilage. The aim of study is to improve differentiation of adipose derived stem cells [ADSCs] into chondrocytes in order to provide a safe and modern treatment for patients suffering from cartilage damages

Methods: After functionalization, dispersions and sterilizing carbon nano-tubes [CNTs], a new type of nanocomposite gel was prepared from water-soluble CNTs and alginate. ADSCs seeded in 1.5% alginate scaffold and cultured in chondrogenic media with and without transforming growth factor-beta1 [TGF-beta1] for 7 and 14 days. The genes expression of sex determining region Y-box 9 [SOX9], types II and X collagens was assessed by real-time polymerase chain reaction and the amount of aggrecan [AGC] and type I collagen was measured by ELISA

Results: Our findings showed that the expression of essential cartilage markers, SOX9, type II collagen and AGC, in differentiated ADSCs at the concentration of 1 microg/ml CNTs in the presence of TGF-beta1 were significantly increased in comparison with the control group [P < 0.001]. Meanwhile, type X collagen expression and also type I collagen production were significantly decreased [P < 0.001]

Conclusions: The results showed that utilized three-dimensional scaffold had a brilliant effect in promoting gene expression of chondrogenesis

Induction of chondrogenic differentiation of human adipose-derived stem cells with TGF-beta3 in pellet culture system

Adult stem cells which are derived from different tissues, with their unique abilities to self-renew and differentiate into various phenotypes have the potential for cell therapy and tissue engineering. Human adipose tissue is an appropriate source of mesenchymal stem cells with wide differentiation potential for tissue engineering research. In this study isolated stem cells from human subcutaneous adipose tissue were investigated for chondrogenic potential of adipose-derived stem cells [ADSCs] in pellet culture system treated with transforming growth factor- beta3 [TGF-beta3]. Human ADSCs were isolated from subcutaneous adipose tissue and digested with collagenase type I. Immunocytochemical method for cell surface antigens was done in order to characterize the cells. The isolated cells were treated with chondrogenic medium, supplemented with TGF-beta3 in pellet culture system and harvested after 21 days. Histological staining was used to evaluate the presence of proteoglycan, with alcian blue. Immunohistochemical method performed for the assessment of cartilage'specific type II collagen and aggrecan. Also, in order to confirm our results, we managed RT-PCR technique. Chondrogenesis of ADSCs in pellet culture, induced by TGF-beta3 growth factor. Histological and immunohistochemical methods showed deposition of typical cartilage extracellular matrix components in pellets. RT-PCR analysis of cartilage matrix genes, such as type II collagen and aggrecan, also, confirmed the induction of the chondrocytic phenotype in high-density culture upon stimulation with TGF-beta3. TGF-beta3 promoted chondrogenesis of ADSC in pellet culture system. We suggest that human subcutaneous adipose stem cells could be excellent candidates for the cartilage tissue engineering

Study of human chondrocyte redifferntiation capacity in three-dimensional hydrogel culture

Articular cartilage tissue defects cannot be repaired by the proliferation of resident chondrocytes. Autologous chondrocyte transplantation [ACT] is a relatively new therapeutic approach to cover full thickness articular cartilage defects by in vitro grown chondrocytes from the joint of a patient. Therefore, we investigated the differentiation capability of human chondrocytes maintained in alginate culture. The cartilage specimens obtained from 50 patients who underwent total knee and hip operations at the teaching hospital of Isfahan University of Medical Sciences, Isfahan Iran. Isolated primary chondrocytes were first grown in monolayer cultures for 1 to 6 passages [each passage lasting about 3 days]. At each passage, monolayer cells seeded in alginate culture and investigated morphologically and immuno-cytologically for expression of cartilage-specific markers [collagen type II and cartilage-specific proteoglycans]. The chondrocytes from monolayer passages PI to P4 introduced in alginate cultures regained a chondrocyte phenotype. Cells were interconnected by typical gap junctions and after few days, they produced a cartilage-specific extracellular matrix [collagen type II and cartilage-specific proteoglycans]. In contrast, cells from monolayer passages P5 and P6 did not redifferentiate to chondrocytes in the alginate cultures. Chondrocyte culture was established for the first time in Iran. The alginate culture conditions promote the redifferentiation of dedifferentiated chondrocytes that have still a chondrogenic potential. This procedure opens up a promising approach to produce sufficient numbers of differentiated chondrocytes for ACT. Indeed, in some patients the harvested cells were used immediately and successfully for transplantation

Access to chondrocyte culture, with alginate, in Iran

In this study, chondrocyte culture was established for the first time in Iran, and calcium alginate was used for longer culture of chondrocyte in vitro. The study was programmed in order to be used for future human chondrocyte transplantation. The cartilage specimen obtained from 50 patients who underwent total knee and hip operations in Isfahan University of Medical Sciences. Cartilage specimens were used for monolayer as well as suspension culture in alginate beads. Approximately 12 +/- 1 millions cells were harvested from the 3[RD] passage. The cells were round with large euchromatic nucleus and several nucleoli and small vacuoles. The cells derived from passages 1 to 4, which were grown up then, in alginate beads, showed higher staining with alcian blue. The harvested cells in some patients were immediately and successfully used for autologus transplantation. This later work will be reported separately