Sung-Chan Shin

Effects of donor age, long-term passage culture, and cryopreservation on tonsil-derived mesenchymal stem cells.

Objectives: Human mesenchymal stem cells (MSCs) are efficacious in various cellular therapeutic applications and have been isolated from several tissues. Recent studies have reported that human tonsil tissue contains a new source of progenitor cells, potentially applicable for cell-based therapies. Information about the effects of donor age, long-term passage and cryopreservation are essential for clinical applications and cell-based therapies. Therefore, the authors investigated how the morphology, cell-surface markers, proliferation potential and differentiation capacity of tonsil-derived MSCs (T-MSCs) were affected by donor age, long-term passage, and cryopreservation. Materials and Methods: T-MSCs were isolated from tonsillar tissue of 20 patients undergoing tonsillectomy. Authors evaluated the effects of donor-age, long-term passage, and cryopreservation on the morphology, surface markers, proliferation potential and differentiation capacities of T-MSCs. Results: T-MSCs exhibited a fibroblast-like, spindle-shaped appearance. There were no significant morphological differences according to donor age, long-term passage or cryopreservation. T-MSCs isolated from donors of various ages were positive for markers CD90, CD44, and CD73, but negative for CD45, CD31, and HLA-DR. There were no significant differences in the expression of positive and negative surface markers as a function of donor age, long-term passage and cryopreservation. T-MSCs from different donor age groups showed similar proliferation potentials after passage 2. After long-term passage and cryopreservation, there were no significant morphological differences. Cryopreservation did not affect the proliferation potential of T-MSCs, but there was a significant decrease in the proliferation potential in long-term passage T-MSCs (passage 15). The effect of donor age, long-term passage and cryopreservation on the in vitro adipogenic, osteogenic, and chondrogenic differentiation potential of T-MSCs was not significant. Conclusion: The effect of donor age, long-term passage culture, and cryopreservation on T-MSC properties are negligible, except for the proliferation capacity of long-term cultured T-MSCs. Therefore, T-MSCs are considered to be promising MSCs that can be used as future alternative sources for autologous or allogenic MSCs.

Tumor location–dependent skip lateral cervical lymph node metastasis in papillary thyroid cancer

Lateral cervical lymph node metastasis without central lymph node (CLN) metastasis is not infrequent in papillary thyroid cancer (PTC). This study was designed to investigate the frequency and pattern of skip metastasis in PTC.

Isolation and Localization of Mesenchymal Stem Cells in Human Palatine Tonsil by W5C5 (SUSD2)

Background/Aims: Although tonsil-mesenchymal stem cells (T-MSCs) have been studied as a new autologous or homologous source of MSCs, research on specific markers of MSCs and localization for purified T-MSC isolation has not yet been reported. This study investigates the expression of W5C5 (SUSD2) in tonsil stromal cells and the colony-forming ability and differentiation potential of W5C5+ cells to determine the usefulness of W5C5+ MSCs as a marker that can be used for the purification of T-MSCs. In addition, the location of W5C5+ cells expressed in the tonsil tissues is examined. Methods: T-MSCs were isolated from the tonsillar tissues of 12 patients undergoing tonsillectomy. The colony-forming ability, surface markers, proliferation potential, and differentiation capacities of purified W5C5+ MSCs, W5C5- MSCs, and unselected T-MSCs were evaluated. The location of the W5C5+ cells in the tonsillar tissues was also investigated by immunohistochemistry. Results: W5C5 was expressed in 2.5±0.4% of fresh human tonsil stromal cells. W5C5+ cells formed many colonies, but W5C5- cells did not form any colonies. The colony-forming number of W5C5+ cells (74.4 ± 9.8) was significantly higher than that of unselected tonsil stromal cells (23.6 ± 3.7). However, the differences in proliferation potential, surface marker expression, and differentiation potential between W5C5+ T-MSCs and unselected T-MSCs were not significant. W5C5+ cells were identified in the perivascular area around the blood vessels. Conclusion: W5C5+ T-MSCs possessed typical MSC properties with high colony-forming efficiency, and niches of W5C5+ T-MSCs were located in the perivascular area of tonsil tissues. These findings suggest that W5C5 is a useful single marker for the isolation of purified T-MSCs.

Predictive factors of right paraesophageal lymph node metastasis in papillary thyroid carcinoma: Single center experience and meta-analysis

Background We performed this retrospective study to identify predictors of right paraesophageal lymph node metastasis, and reviewed previous studies related to this topic. Methods Between June 2005 and March 2015, 1107 patients were diagnosed with papillary thyroid carcinoma and underwent surgery at Pusan National University Hospital. Results Right paraesophageal lymph node metastasis was observed in 171 (15.4%) patients. Multivariate analyses showed that the risk of right paraesophageal metastasis was significantly associated with tumor size, location, a higher number of metastatic central lymph nodes, and lateral lymph node metastasis. In a meta-analysis of the eligible studies, tumor size, number of metastatic central lymph nodes, and lateral lymph node metastasis showed significant relationships with the risk of right paraesophageal metastasis. Conclusions In patients with risk factors such as those identified in our study, the possibility of right paraesophageal metastasis should be kept in mind, and careful inspection and dissection are required.

Development of an Attachable Endoscopic Nerve Stimulator for Intraoperative Neuromonitoring during Endoscopic or Robotic Thyroidectomy

We developed a simple attachable endoscopic nerve stimulator that can be connected to monopolar cauterization surgical instruments. This study on porcine models aimed to investigate the feasibility and efficacy of an attachable endoscopic nerve stimulator for intraoperative neuromonitoring (IONM) before application in humans. We evaluated the electromyography (EMG) amplitudes of 8 recurrent laryngeal nerves in 4 pigs with a conventional nerve probe and the attachable endoscopic nerve stimulator. The attachable endoscopic nerve stimulator was feasible and safe in all cases. There was no significant difference in the EMG amplitude of the recurrent laryngeal nerve among instruments (P = .429). The application of stimulating dissection with an attachable endoscopic nerve stimulator during endoscopic or robotic thyroidectomy with IONM is simple, convenient, and effective. It provides surgeons with real-time feedback of the EMG response during intermittent IONM. We believe that this novel device could be an essential guide and functional navigator for most surgeons, especially for less experienced ones.

TSH-independent release of thyroid hormones through cold exposure in aging rats

Thyroid function decreases and cold exposure response becomes impaired with increasing age. We investigated the age-related changes in thyroid structure and function and cold-induced changes in the thyroid activity of aging rats. Thirty-two male Sprague–Dawley rats were randomly divided into four groups (8 rats per group): young (7 months) and old (22 months) groups exposed to room temperature and cold stress. The active follicle ratio and serum free T3, T4 and TSH, and TSH receptor (TSHR) concentrations in the thyroid tissues of the rats from each group were compared. At room temperature, old rats had significantly lower active follicle ratio and free T3 and T4 concentrations than young rats. Furthermore, old rats displayed higher TSH level than young. Exposure to cold temperature led to significantly increased active colloid ratio and free T3 and T4 concentrations among old rats, but no significant differences were found among young rats. Additionally, no significant changes in the TSH and TSHR levels were observed after cold exposure in both young and old rats. Old rats have lower thyroid function than young rats under normal temperature. Aging rats are more susceptible to cold stress than young rats, and cold-induced thyroid activation occurs independently of TSH. We investigated the age-related changes in the thyroid structure and function and cold-induced changes in the thyroid activity of aging rats. Aging rats have structurally less active thyroid follicles and functionally lower thyroid hormone levels than young rats. Furthermore, old rats are more susceptible to cold stress than young rats, and cold-induced thyroid activation occurs independently of TSH.

Decellularization of Human Nasal Septal Cartilage for the Novel Filler Material of Vocal Fold Augmentation.

OBJECTIVES The clinical application of allogenic and/or xenogenic cartilage for vocal fold augmentation requires to remove the antigenic cellular component. The objective of this study was to assess the effect of cartilage decellularization and determine the change in immunogenicity after detergent treatment in human nasal septal cartilage flakes made by the freezing and grinding method. METHODS Human nasal septal cartilages were obtained from surgical cases. The harvested cartilages were treated by the freezing and grinding technique. The obtained cartilage flakes were treated with 1% Triton X-100 or 2% sodium dodecyl sulfate (SDS) for decellularization of the cartilage flakes. Hematoxylin and eosin stain (H&E stain), surface electric microscopy, immunohistochemical stain for major histocompatibility complex I and II, and ELISA for DNA contents were performed to assess the effect of cartilage decellularization after detergent treatment. RESULTS A total of 10 nasal septal cartilages were obtained from surgical cases. After detergent treatment, the average size of the cartilage flakes was significantly decreased. With H&E staining, the cell nuclei of decellularized cartilage flakes were not observed. The expression of major histocompatibility complex (MHC)-I and II antigens was not identified in the decellularized cartilage flakes after treatment with detergent. DNA content was removed almost entirely from the decellularized cartilage flakes. CONCLUSION Treatment with 2% SDS or 1% Triton X-100 for 1 hour appears to be a promising method for decellularization of human nasal septal cartilage for vocal fold augmentation.

Orbital metastasis as the primary presentation of nasopharyngeal carcinoma

Metastasis to the orbit, which is uncommon due to the character of the orbital volume with relative stenosis, is estimated to account for 1--13% of all orbital tumors.1 Orbital metastasis is believed to occur in approximately 2--3% of patients with systemic cancer.2 The incidence of metastatic orbital tumors varies widely, according to geographical area and race; the most common primary cancers that metastasize to the orbit are breast, prostate, liver, and lung cancer.1,2 Although nasopharyngeal carcinoma (NPC) involves the orbits through direct extension to the orbital apex, metastasis of NPC to the orbit has rarely been reported. This report describes two cases of intraorbital, extrabulbar metastases from NPC.

Evaluation of decellularized xenogenic porcine auricular cartilage as a novel biocompatible filler: EVALUATION OF DECELLULARIZED XENOGENIC PORCINE AURICULAR CARTILAGE

Fillers are products that fill the space in soft tissues of the human body and actively used in the various medical fields. Unfortunately, most of the cost-effective commercially available fillers are synthetic and have limitations in terms of their biocompatibility. Here, we evaluated the possible application of decellularized xenogenic cartilage as a long-lasting material for soft tissue augmentation and compared it with two commercially available fillers Artesense (polymethylmethacrylate microspheres) and Radiesse (calcium hydroxyapatite [CaHa]). To do so, porcine auricular cartilage was harvested, followed by freezing and grinding of the tissue into flakes. Then, we used 1% Triton X-100 to decellularize the flakes. We then, respectively, injected 0.1 cc of each material (decellularized xenogenic cartilage, Radiesse, and Artesense) into the subcutaneous layer at three different sites per subject in 12 Sprague-Dawley rats, and evaluated the inflammatory cell infiltration and foreign body reactions of each. Our data indicate that the infiltration of giant cells in the injection area was significantly lower in the decellularized xenogenic cartilage injection group than that in the Radiesse and Artesense injection groups. Further, we observed some neutrophil infiltration in the xenogenic cartilage and Artesense injection groups at 1 month, but these levels were much lower at 3 months (comparable to the Radiesse injection group). Thus, decellularized xenogenic cartilage may have a distinct advantage in terms of biocompatibility compared with other commercial injectable long-lasting fillers, making it one of the most feasible, natural, and cost effective materials in the market.

Prognostic implication of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with recurrent papillary thyroid cancer

Fluorine‐18 fluorodeoxyglucose positron emission tomography/CT (18F‐FDG PET/CT) has been widely accepted as an effective method for detecting recurrent papillary thyroid cancer (PTC) in patients with increased serum thyroglobulin (Tg) or Tg antibody (TgAb) levels and negative whole‐body scintigraphy (WBS) results. The role of WBS as a diagnostic tool in detecting recurrence has relatively decreased recently. However, only a few studies have examined the usefulness of 18F‐FDG PET/CT for evaluating patients with recurrent PTC, regardless of the WBS results. The purpose of this analysis was to evaluate the diagnostic value and prognostic role of 18F‐FDG PET/CT for patients with recurrent PTC, irrespective of their WBS results.