An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an <em>In Vivo</em> Porcine Lumbar Spine Model

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle ...

University of Seonam College of Medicine, Presbyterian Medical Center

The effect of average pore size of nano-pore silica particles on protein adsorption characteristics was determined experimentally by the dissociation constant and the adsorption capacity determined from the Langmuir equation. As the average pore size was increased from 2.2 to 45 nm, the BSA adsorption capacity increased from 16.8 to 84.3 mg/g-silica so as the equilibrium constant (from 2.6 to 9.4 mg/ml). Using confocal microscopy with fluorescence labeling, we could visualize the protein adsorption in situ and determine the minimum pore size required for efficient intraparticle adsorption. The confocal microscopy analysis revealed that BSA was adsorbed mainly on the surface of the particles with a smaller pore size, but diffused further into the interstitial surface when it was sufficiently large. It was concluded that for BSA whose Stoke's diameter is ca. 3.55 nm the minimum pore size of about 45 nm or larger was required for a sufficient adsorption capacity.

Analysis of protein adsorption characteristics to nano-pore silica particles by using confocal laser scanning microscopy.

In this article we report recovery of mesoporous silica from the waste material (hexafluorosilicic acid) of phosphate fertilizer industry. The process involves the reaction of hexafluorosilicic acid (50 ml, 24 wt% H(2)SiF(6)) and 100ml, 0.297 M Na(2)CO(3) to generate the alkaline aqueous slurry. Silica was separated from the slurry by filtration and the sodium fluoride was extracted from the aqueous solution by evaporation method. The obtained mesoporous silica was characterized by N(2) absorption/desorption (BET), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and EDS. The results confirm that the separation of silica and NaF was successful and the final products have high purity. The silica product was found to have an average pore diameter of 4.14 nm and a high surface area (up to 800 m(2)/g). The process reported in this study may significantly reduce the release of hazardous materials into the environment and it might confer economic benefits to the responsible industries.

Recovery of high surface area mesoporous silica from waste hexafluorosilicic acid (H2SiF6) of fertilizer industry.

Conventional epidermal cysts are generally small, slow-growing, non-tender, dome-shaped lesions. An epidermal cyst is usually asymptomatic until it is infected or enlarged to the extent that it causes damage to adjacent anatomical structures. However, few cases of giant epidermal cysts in the neck have been reported. The present case reports a giant epidermal cyst in the posterior neck, which grew to an extremely large size for >40 years without inflammation or rupture, and was misdiagnosed as a large soft tissue neoplasm. The patient exhibited depression and developed social anxiety due to the negative cosmetic consequences of the large mass. The patient underwent excision of the mass. At the follow-up examination two years postoperatively, there were no local recurrence and the psychiatric symptoms of the patient were completely resolved. To the best of our knowledge, a giant epidermal cyst growing for >40 years has not previously been reported.

Giant epidermal cyst in the posterior neck developing over 40 years: A case report.

Bone morphogenetic proteins (BMPs) are crucial regulators of chondrogenesis. BMPs transduce their signals through three type I receptors: BMPR1A, BMPR1B, and ACVR1/ALK2. Fibrodysplasia ossificans progressiva (FOP), a rare disorder characterized by progressive ossification of connective tissue, is caused by an activating mutation in Acvr1 (the gene that encodes ACVR1/ALK2). However, there are few developmental defects associated with FOP. Thus, the role of ACVR1 in chondrogenesis during development is unknown. Here we report the phenotype of mice lacking ACVR1 in cartilage. Acvr1(CKO) mice are viable but exhibit defects in the development of cranial and axial structures. Mutants exhibit a shortened cranial base, and cervical vertebrae are hypoplastic. Acvr1(CKO) adult mice develop progressive kyphosis. These morphological defects were associated with decreased levels of Smad1/5 and p38 activation, and with reduced rates of chondrocyte proliferation in vertebral cartilage. We also tested whether ACVR1 exerts coordinated functions with BMPR1A and BMPR1B through analysis of double mutants. Acvr1/Bmpr1a and Acvr1/Bmpr1b mutant mice exhibited generalized perinatal lethal chondrodysplasia that was much more severe than in any of the corresponding mutant strains. These findings demonstrate that ACVR1 is required for chondrocyte proliferation and differentiation, particularly in craniofacial and axial elements, but exerts coordinated functions with both BMPR1A and BMPR1B throughout the developing endochondral skeleton.

The type I BMP receptor ACVR1/ALK2 is required for chondrogenesis during development.

Adjacent segment pathology following anterior decompression and fusion using cage and plate for the treatment of degenerative cervical spinal diseases.

Substantial research documents the determinants of entry into the academic career, yet little is known about how these determinants have evolved over time. Using data from a large sample of Korean scholars who received their doctoral degrees between 1980 and 2010, we estimate discrete-time event history models of transitioning to an academic position in any academic field. Results indicate that universalistic characteristics, such as publication record, strongly affect subsequent career success, but so do particularistic factors, including doctoral institution prestige. Since the 1980s, the influence of doctoral degree prestige increased substantially more than the influence of one's publication record on higher education employment, implying that the rising importance of particularistic factors has outpaced growing consideration of universalistic characteristics in Korean academia. However, the importance of gender on academic employment has declined since the early 2000s, suggesting that the implementation of employment quotas for female professors may have stymied gender discrimination.

Trends in Determinants of Entry into the Academic Career: The Case of South Korea, 1980-2010.

Trabecular bone is frequently studied in osteoporosis research because changes in trabecular bone are the most common cause of osteoporotic fractures. Dual energy X-ray absorptiometry (DXA) analysis specific to trabecular bone-rich regions is crucial to longitudinal osteoporosis research. The purpose of this study is to define a novel method for accurately analyzing trabecular bone-rich regions in mice via DXA. This method will be utilized to analyze scans obtained from the International Space Station in an upcoming study of microgravity-induced bone loss. Thirty 12-week-old BALB/c mice were studied. The novel method was developed by preanalyzing trabecular bone-rich sites in the distal femur, proximal tibia, and lumbar vertebrae via high-resolution X-ray imaging followed by DXA and micro-computed tomography (micro-CT) analyses. The key DXA steps described by the novel method were (1) proper mouse positioning, (2) region of interest (ROI) sizing, and (3) ROI positioning. The precision of the new method was assessed by reliability tests and a 14-week longitudinal study. The bone mineral content (BMC) data from DXA was then compared to the BMC data from micro-CT to assess accuracy. Bone mineral density (BMD) intra-class correlation coefficients of the new method ranging from 0.743 to 0.945 and Levene's test showing that there was significantly lower variances of data generated by new method both verified its consistency. By new method, a Bland-Altman plot displayed good agreement between DXA BMC and micro-CT BMC for all sites and they were strongly correlated at the distal femur and proximal tibia (r=0.846, p<0.01; r=0.879, p<0.01, respectively). The results suggest that the novel method for site-specific analysis of trabecular bone-rich regions in mice via DXA yields more precise, accurate, and repeatable BMD measurements than the conventional method.

Guidelines for Dual Energy X-Ray Absorptiometry Analysis of Trabecular Bone-Rich Regions in Mice: Improved Precision, Accuracy, and Sensitivity for Assessing Longitudinal Bone Changes.

Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochondral lesion with subchondral cyst and discuss the mechanism involved in the development of subchondral cyst.

Is retrograde drilling really useful for osteochondral lesion of talus with subchondral cyst?: A case report.

Dislocation of the lunate and proximal pole of the scaphoid with displacement of the fragments proximal to the radiocarpal joint, characterized as a total dislocation, is very rare, with only six cases reported. Dislocated lunate are generally located around the radiocarpal joint or within carpal ligament. However, there have been no reports of dislocated lunate over the carpal ligament. We present a patient with volar dislocation of the lunate that featured extreme migration to approximately 6 cm proximal to flexor digitorum superficialis through the transcarpal ligament.

Jong-Kil Kim

Department of Orthopaedic Surgery

University of Seonam College of Medicine, Presbyterian Medical Center

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Jong-Kil Kim

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Orthopaedic Surgery

University of Seonam College of Medicine, Presbyterian Medical Center

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model

Department of Orthopaedic Surgery