Direct Internal Fixation for Unstable Atlas Fractures

Purpose@#To investigate the radiologic and clinical outcomes of direct internal fixation for unstable atlas fractures. @*Materials and Methods@#This retrospective study included 12 patients with unstable atlas fractures surgically treated using C1 lateral mass screws, rods, and transverse connector constructs. Nine lateral mass fractures with transverse atlantal ligament (TAL) avulsion injury and three 4-part fractures with TAL injury (two avulsion injuries, one TAL substance tear) were treated. Radiologic outcomes included the anterior atlantodental interval (AADI) in flexion and extension cervical spine lateral radiographs at 6 months and 1 year after treatment. CT was also performed to visualize bony healing of the atlas at 6 months and 1 year. Visual Analog Scale (VAS) scores for neck pain, Neck Disability Index (NDI) values, and cervical range of motion (flexion, extension, and rotation) were recorded at 6 months after surgery. @*Results@#The mean postoperative extension and flexion AADIs were 3.79±1.56 (mean±SD) and 3.13±1.01 mm, respectively. Then mean AADI was 3.42±1.34 and 3.33±1.24 mm at 6 months and 1 year after surgery, respectively. At 1 year after surgery, 11 patients showed bony healing of the atlas on CT images. Only one patient underwent revision surgery 8 months after primary surgery due to nonunion and instability findings. The mean VAS score for neck pain was 0.92±0.99, and the mean NDI value was 8.08±5.70. @*Conclusion@#C1 motion-preserving direct internal fixation technique results in good reduction and stabilization of unstable atlas fractures. This technique allows for the preservation of craniocervical and atlantoaxial motion.

Effects of three-dimensionally printed polycaprolactone/β-tricalcium phosphate scaffold on osteogenic differentiation of adipose tissue- and bone marrow-derived stem cells

BACKGROUND: Autogenous bone grafts have several limitations including donor-site problems and insufficient bone volume. To address these limitations, research on bone regeneration is being conducted actively. In this study, we investigate the effects of a three-dimensionally (3D) printed polycaprolactone (PCL)/tricalcium phosphate (TCP) scaffold on the osteogenic differentiation potential of adipose tissue-derived stem cells (ADSCs) and bone marrow-derived stem cells (BMSCs). METHODS: We investigated the extent of osteogenic differentiation on the first and tenth day and fourth week after cell culture. Cytotoxicity of the 3D printed PCL/β-TCP scaffold was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, prior to osteogenic differentiation analysis. ADSCs and BMSCs were divided into three groups: C, only cultured cells; M, cells cultured in the 3D printed PCL/β-TCP scaffold; D, cells cultured in the 3D printed PCL/β-TCP scaffold with a bone differentiation medium. Alkaline phosphatase (ALP) activity assay, von Kossa staining, reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting were performed for comparative analysis. RESULTS: ALP assay and von Kossa staining revealed that group M had higher levels of osteogenic differentiation compared to group C. RT-PCR showed that gene expression was higher in group M than in group C, indicating that, compared to group C, osteogenic differentiation was more extensive in group M. Expression levels of proteins involved in ossification were higher in group M, as per the Western blotting results. CONCLUSION: Osteogenic differentiation was increased in mesenchymal stromal cells (MSCs) cultured in the 3D printed PCL/TCP scaffold compared to the control group. Osteogenic differentiation activity of MSCs cultured in the 3D printed PCL/TCP scaffold was lower than that of cells cultured on the scaffold in bone differentiation medium. Collectively, these results indicate that the 3D printed PCL/TCP scaffold promoted osteogenic differentiation of MSCs and may be widely used for bone tissue engineering.

From Bench to Market: Preparing Human Pluripotent Stem Cells Derived Cardiomyocytes for Various Applications

Human cardiomyocytes (CMs) cease to proliferate and remain terminally differentiated thereafter, when humans reach the mid-20s. Thus, any damages sustained by myocardium tissue are irreversible, and they require medical interventions to regain functionality. To date, new surgical procedures and drugs have been developed, albeit with limited success, to treat various heart diseases including myocardial infarction. Hence, there is a pressing need to develop more effective treatment methods to address the increasing mortality rate of the heart diseases. Functional CMs are not only an important in vitro cellular tool to model various types of heart diseases for drug development, but they are also a promising therapeutic agent for cell therapy. However, the limited proliferative capacity entails difficulties in acquiring functional CMs in the scale that is required for pathological studies and cell therapy development. Stem cells, human pluripotent stem cells (hPSCs) in particular, have been considered as an unlimited cellular source for providing functional CMs for various applications. Notable progress has already been made: the first clinical trials of hPSCs derived CMs (hPSC-CMs) for treating myocardial infarction was approved in 2015, and their potential use in disease modeling and drug discovery is being fully explored. This concise review gives an account of current development of differentiation, purification and maturation techniques for hPSC-CMs, and their application in cell therapy development and pharmaceutical industries will be discussed with the latest experimental evidence.

Histological Analysis of In Vitro Co-Culture and In Vivo Mice Co-Transplantation of Stem Cell-Derived Adipocyte and Osteoblast

Many researchers have focused on the role of adipocytes in increasing efficient bone tissue engineering and osteogenic differentiation of stem cells. Previous reports have not reached a definite consensus on whether adipocytes positively influence in vitro osteogenic differentiation and in vivo bone formation. We investigated the adipocyte influence on osteogenic differentiation from adipose-derived stromal cells (ADSCs) and bone formation through histological analysis in vitro and in vivo. Using the direct co-culture system, we analyzed the influence of adipocytes to promote the differentiation fate of ADSCs. Using co-transplantation of ADSC-derived adipocytes and osteoblasts into the dorsal region of mice, the osteogenesis and bone quality were determined by histological morphology, radiography, and the measurement of the Ca²⁺ concentration. The adipocyte negatively affected the osteoblast differentiation of ADSCs in the in vitro system and induced osteogenesis of osteoblasts in the in vivo system through co-transplantation. Interestingly, in the co-transplanted adipocytes and osteoblasts, the bone formation areas decreased in the osteoblast only group compared with the mixed adipocytes and osteoblast group 6 weeks after transplantation. Conversely, co-transplantation and osteoblast transplantation had similar degrees of calcification as observed from radiography analysis and the measurement of the Ca²⁺ concentrations. Our results revealed that adipocytes inhibited osteoblast differentiation in vitro but enhanced the efficacy of osteogenesis in vivo. In addition, the adipocytes controlled the activity of osteoclasts in the newly formed bone tissue. Our approach can be used to reconstruct bone using stem cell-based tissue engineering and to enhance the understanding of the role adipocytes play.

Directing Human Embryonic Stem Cells towards Functional Endothelial Cells Easily and without Purification

Hemangioblasts or blood islands only arise in early development thereby the sources to obtain these bi-potential cells are limited. While previous studies have isolated both lineages in vitro through the hemangioblast, derivation efficiency was rather low due to cellular damage attributed by enzyme usage and fluorescent activated cell sorting (FACS). This study focused on avoiding the use of damaging factors in the derivation of endothelial cells (ECs). Single cell H9-human embryonic stem cells (hESCs) were obtained by using a mild dissociation protocol then human embryoid body (hEB) formation was performed under hemangioblast differentiation conditions. The hEBs were subjected to a two-stage cytokine treatment procedure. Subsequent culture of the adhesive cells in day 4 hEBs gave arise to a seemingly pure population of ECs. The hESC-derived ECs were characterized by identifying signature endothelial gene and protein markers as well as testing for in vitro functionality. Furthermore, in vivo functionality was also confirmed by transplanting the cells in hindlimb ischemic murine models. We demonstrate that the genetic change required for EC derivation precedes blast colony formation. Furthermore, cell damage was prevented by abating enzyme usage and FACS, resulting in a high yield of ECs upon adhesion. Under this method, confluent cultures of ECs were obtainable 4 days after hEB formation which is significantly faster than previous protocols.

Analysis of Single Nucleotide Polymorphism in Adolescent Idiopathic Scoliosis in Korea: For Personalized Treatment

PURPOSE: The incidence of adolescent idiopathic scoliosis (AIS) has rapidly increased, and with it, physician consultations and expenditures (about one and a half times) in the last 5 years. Recent etiological studies reveal that AIS is a complex genetic disorder that results from the interaction of multiple gene loci and the environment. For personalized treatment of AIS, a tool that can accurately measure the progression of Cobb's angle would be of great use. Gene analysis utilizing single nucleotide polymorphism (SNP) has been developed as a diagnostic tool for use in Caucasians but not Koreans. Therefore, we attempted to reveal AIS-related genes and their relevance in Koreans, exploring the potential use of gene analysis as a diagnostic tool for personalized treatment of AIS therein. MATERIALS AND METHODS: A total of 68 Korean AIS and 35 age- and sex-matched, healthy adolescents were enrolled in this study and were examined for 10 candidate scoliosis gene SNPs. RESULTS: This study revealed that the SNPs of rs2449539 in lysosomal-associated transmembrane protein 4 beta (LAPTM4B) and rs5742612 in upstream and insulin-like growth factor 1 (IGF1) were associated with both susceptibility to and curve severity in AIS. The results suggested that both LAPTM4B and IGF1 genes were important in AIS predisposition and progression. CONCLUSION: Thus, on the basis of this study, if more SNPs or candidate genes are studied in a larger population in Korea, personalized treatment of Korean AIS patients might become a possibility.

The Combined Effects of Ginkgo Biloba Extracts and Aspirin on Viability of SK-N-MC, Neuroblastoma Cell Line in Hypoxia and Reperfusion Condition

OBJECTIVE: The purpose of this study is to investigate the combined effects of ginkgo biloba extract, ginkgolide A and B and aspirin on SK-N-MC, human neuroblastoma cell viability and mRNA expression of growth associated protein43 (GAP43), Microtubule-associated protein 2 (MAP2), B-cell lymphoma2 (Bcl2) and protein53 (p53) gene in hypoxia and reperfusion condition. METHODS: SK-N-MC cells were cultured with Dulbecco's Modified Eagle's Medium (DMEM) media in 37degrees C, 5% CO2 incubator. The cells were cultured for 8 hours in non-glucose media and hypoxic condition and for 12 hours in normal media and O2 concentration. Cell survival rate was measured with Cell Counting Kit-8 (CCK-8) reagent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to estimate mRNA levels of GAP43, MAP2, Bcl2, and p53 genes. RESULTS: The ginkgolide A and B increased viable cell number decreased in hypoxic and reperfused condition. The co-treatment of ginkgolide B with aspirin also increased the number of viable cells, however, there was no additive effect. Although there was no increase of mRNA expression of GAP43, MAP2, and Bcl2 in SK-N-MC cells with individual treatment of ginkgolide A, B or aspirin in hypoxic and reperfused condition, the co-treatment of ginkgolide A or B with aspirin significantly increased GAP43 and Bcl2 mRNA levels. In MAP2, only the co-treatment of ginkgolide A and aspirin showed increasing effect. The mRNA expression of p53 had no change in all treating conditions. CONCLUSION: This study suggests that the combined treatments of Ginkgo biloba extracts and aspirin increase the regeneration of neuroblastoma cells injured by hypoxia and reperfusion.

Human Umbilical Cord Blood Mononuclear Cell Transplantation in Rats with Intrinsic Sphincter Deficiency

To evaluate the effectiveness of the human umbilical cord blood (HUCB) transplantation for the treatment of intrinsic sphincter deficiency (ISD), we analyzed the short term effects of HUCB mononuclear cell transplantation in rats with induced-ISD. ISD was induced in rats by electro-cauterization of periurethral soft tissue with HUCB mononuclear cell injection after 1 week. The sphincter function measured by mean leak point pressure was significantly improved in the experimental group compared to the control group at 4 weeks. (91.75+/-18.99 mmHg vs. 65.02+/-22.09 mmHg, P=0.001). Histologically, the sphincter muscle was restored without damage while in the control group it appeared markedly disrupted with atrophic muscle layers and collagen deposit. We identified injected HUCB cells in the tissue sections by Di-I signal and Prussian blue staining. HUCB mononuclear cell injection significantly improved urethral sphincter function, suggesting its potential efficacy in the treatment of ISD.

Characterization of Lentogenic Newcastle Disease Virus Isolated in Jeju, Korea during 2007~2008 Surveillance

To expand the epidemiological understanding of Newcastle disease in Jeju Province, Korea, active surveillance was extensively performed through a virological examination for poultry farms and wild birds in Jeju Province during 2007~2008. Samples (swabs or fresh feces) were collected from a total of 6,485 birds including 6,405 domestic birds (chickens, ducks, pheasants, geese, quails, turkeys, and ostriches) and 80 wild birds. A total of 24 hemagglutinating agents were isolated from domestic birds on fourteen farms including five Korean native chicken, one layer chicken, two broiler chicken, four duck and two pheasant farms. The hemagglutinating agents were all identified as lentogenic NDV based on the reverse transcriptase polymerase chain reaction, sequence analysis of amino acids on the F cleavage site and mean death time in chicken embryos. The F gene-based phylogenetic analysis revealed that the NDV isolates were classified into genotypes 1 or 2 of class II. These lentogenic viruses were closely related to NDV vaccine strains used in Jeju Province. Active surveillance conducted for Newcastle disease indicates no scientific evidence of virulent NDV infection in chickens in Jeju Province, Korea since 2005.

Learning Curve for the Thoracoscopic Correction of Spinal Deformities / 대한척추외과학회지

STUDY DESIGN: Twenty-six consecutive cases were prospectively studied by chart review and radiography. OBJECTIVES: The aim of this study was to find the learning curve of spinal thoracoscopy in spinal deformity surgery. SUMMARY OF LITERATURE REVIEW : Although the efficacy and learning curve of thoracoscopic deformity spinal surgery are well documented in many countries, there is no report in Korea. METHODS: Twenty-six consecutive patients who were underwent VATS were studied. Idiopathic scoliosis was diagnosed in 23 patients (King type II in 15, type III in 5, type IV in 3), neuromuscular scoliosis in 2 and kyphotic deformity in one. In 14 cases of idiopathic scoliosis VATS for anterior release, bonegraft and instrumentation were performed. In the remaining 12 cases of anterior release, bone graft by VATS was done without instrumentation. RESULTS: The average number of discs excised was 5.2+/-0.97. The average time of surgery for the 14 cases was 7.3+/-1.3 hours, which represented 1.37+/-0.25 hours per disc. Excluding the time of instrumentation in the 26 cases, the average time for anterior release and bone grafting was 3.87+/-0.87 hours, which represented 0.76+/-0.18 hours per disc. The average operation time diminished as the series continued. Average blood loss was 748.9+/-254 mL, which represented 152.6+/-65.6 mL per disc. The Cobb's angle was corrected by 62% on average. Complications were found in 11 cases: screw cap breakage in 3, atelectasis in 4, and intercostal nerve injury in 4. There was no serious complication. CONCLUSIONS: VAST for spinal deformity is a safe and effective alternative to thoracotomy, however, the learning curve for this procedure is quite difficult.

Animal Model and Gene Expression Analysis During the Accelerated Fracture Healing in Traumatic Brain Injury / 대한정형외과연구학회지

PURPOSE: This study was performed to create a traumatic brain injury (TBI) animal model of up-regulated bone formation, and to show the possibility of comprehensive analysis of early gene expression from the hard tissue by cDNA microarray technique. MATERIALS AND METHODS: Thirty Sprague-Dawley rats underwent either a severe brain injury operation procedure using the water pump with femur fracture (Group I, N=15), or femur frecture only (group II, N=15). The femur was nailed with a 20-gauge needle and fractured. The rats were euthanized at the day 1, 3, 8, 14, and 28 day. The volume of callus was calculated using GE PACS(R). The total RNA was isolated from the 3rd day's callus and the gene expression was compared using microarray chips. RESULTS: The average time until union was 28 days for control group and 14 days for TBI group, which was significantly shorter. The volume of the callus (27.4+/-8.5 mm2) in the TBI animals was clearly greater than that of the control group (13.0+/-6.3 mm2). The mRNA was successfully extracted from the callus and analysed using the c-DNA microarray, and. 312 genes were significantly increased and 227 genes were decreased in the TBI group. CONCLUSION: This study successfully made a model for a accelerated fracture healing in traumatic brain injury. We showed that cDNA microarray technique can be used to compare the expression of the mRNA in fracture callus. This method will be helpful in analysing the mechanism of accelerated fracture healing after brain injury.

A Case Report of Tuberous Sclerosis

A 13 years old boy who had typical triad of tuberous sclerosis-adenoma cebaceum, mental deficiency, and epileptic seizure-was presented. He also had some white patches on his right buttock and shagreen patches on his right thigh. The finding of histopathologic biopsy was compatible with an angiofibromatosis. The pedigree of his family was investigated and seemed to be a sporadic.