In vitro comparison of the accuracy of an occlusal plane transfer method between facebow and POP bow systems in asymmetric ear position

PURPOSE@#. This in vitro study aimed to compare the accuracy of the conventional facebow system and the newly developed POP (PNUD (Pusan National University Dental School) Occlusal Plane) bow system for occlusal plane transfer in asymmetric ear position. @*MATERIALS AND METHODS@#. Two dentists participated in this study, one was categorized as Experimenter 1 and the other as Experimenter 2 based on their clinical experience with the facebow (1F, 2F) and POP bow (1P, 2P) systems. The vertical height difference between the two ears of the phantom model was set to 3 mm. Experimenter 1 and Experimenter 2performed the facebow and POP bow systems on the phantom model 10 times each, and the transfer accuracy was analyzed. The accuracy was evaluated by measuring the angle between the reference virtual plane (RVP) of the phantom model and the experimental virtual plane (EVP) of the upper mounting plate through digital superimposition. All data were statistically analyzed using a paired t-test (P .05). @*CONCLUSION@#. In cases of asymmetric ear position, the POP bow system may transfer occlusal plane information more accurately than the facebow system in the frontal view, regardless of clinical experience.

The Influence of Face Shields on the Quality of Colonoscopy in the Era of the COVID-19 Pandemic

Background/Aims@#The worldwide coronavirus disease 2019 pandemic has led endoscopists to use personal protective equipment (PPE) for infection prevention. This study aimed to investigate whether wearing a face shield as PPE affects the quality of colonoscopy. @*Methods@#We reviewed the medical records and colonoscopy findings of patients who underwent colonoscopies at Asan Medical Center, Korea from March 10 to May 31, 2020. The colonoscopies in this study were performed by five gastroenterology fellows and four expert endoscopists. We compared colonoscopy quality indicators, such as withdrawal time, adenoma detection rate (ADR), mean number of adenomas per colonoscopy (APC), polypectomy time, and polypectomy adverse events, both before and after face shields were added as PPE on April 13, 2020. @*Results@#Of the 1,344 colonoscopies analyzed, 715 and 629 were performed before and after the introduction of face shields, respectively. The median withdrawal time was similar between the face shield and no-face shield groups (8.72 minutes vs 8.68 minutes, p=0.816), as was the ADR (41.5% vs 39.8%, p=0.605) and APC (0.72 vs 0.77, p=0.510). Polypectomy-associated quality indicators, such as polypectomy time and polypectomy adverse events were also not different between the groups. Quality indicators were not different between the face shield and no-face shield groups of gastroenterology fellows, or of expert endoscopists. @*Conclusions@#Colonoscopy performance was not unfavorably affected by the use of a face shield. PPE, including face shields, can be recommended without a concern about colonoscopy quality deterioration.

Full mouth rehabilitation with vertical dimension increase in patient with severely worn out dentition: A case report / 대한치과보철학회지

Excessive teeth wear can lead to reduced chewing efficiency, occlusal plane collapse, and facial changes. Full mouth rehabilitation with a change in vertical dimension may cause pain in the temporomandibular joint, masticatory muscle and teeth, so an accurate diagnosis and treatment plan is required. In this case, a 69-year-old man had excessive teeth wear with a loss of posterior support. We evaluated the degree of adaptation to the increased vertical dimension with the removable occlusal splint and provisional restoration. We report this case because the treatment result has been functionally and aesthetically satisfactory by providing stable anterior guidance, proper posterior teeth disclusion, and even contact of all teeth in centric occlusion.

Full mouth rehabilitation with vertical dimension increase in patient with severely worn out dentition: A case report / 대한치과보철학회지

Excessive teeth wear can lead to reduced chewing efficiency, occlusal plane collapse, and facial changes. Full mouth rehabilitation with a change in vertical dimension may cause pain in the temporomandibular joint, masticatory muscle and teeth, so an accurate diagnosis and treatment plan is required. In this case, a 69-year-old man had excessive teeth wear with a loss of posterior support. We evaluated the degree of adaptation to the increased vertical dimension with the removable occlusal splint and provisional restoration. We report this case because the treatment result has been functionally and aesthetically satisfactory by providing stable anterior guidance, proper posterior teeth disclusion, and even contact of all teeth in centric occlusion.

Cross Mapping of Standardized Nursing Diagnoses and Problems with NANDA-I in 4 Tertiary Hospitals / 임상간호연구

Purpose@#To explore the scope and method of applying standardized nursing terminologies to nursing diagnosis and problems used in nursing practice. @*Methods@#A descriptive study was done with a retrospective analysis of the nursing records of 141,420 patients that were hospitalized in 4 tertiary hospitals. The nursing diagnosis and problems collected from the records were standardized, and the standardized nursing diagnosis and problems cross mapped with NANDA-I, confirmed in a nursing focus group. @*Results@#65 (67.7%) of the 96 standardized nursing diagnosis and problems were equal with NANDA-I and included in the 10 domains of NANDA-I. Among 86 nursing diagnosis and problems excluded from the cross mapping with NANDA-I, the 63 terms (73.3%) related to surgery/procedure were the most common. @*Conclusion@#It is meaningful that multi-tertiary hospital nursing diagnosis and problems were standardized and cross mapping with standard nursing terminologies was performed. As for the method of applying standardized nursing terminologies in nursing practice, it is appropriate to use several standardized nursing terminologies complementarily.

Cross Mapping of Standardized Nursing Diagnoses and Problems with NANDA-I in 4 Tertiary Hospitals / 임상간호연구

Purpose@#To explore the scope and method of applying standardized nursing terminologies to nursing diagnosis and problems used in nursing practice. @*Methods@#A descriptive study was done with a retrospective analysis of the nursing records of 141,420 patients that were hospitalized in 4 tertiary hospitals. The nursing diagnosis and problems collected from the records were standardized, and the standardized nursing diagnosis and problems cross mapped with NANDA-I, confirmed in a nursing focus group. @*Results@#65 (67.7%) of the 96 standardized nursing diagnosis and problems were equal with NANDA-I and included in the 10 domains of NANDA-I. Among 86 nursing diagnosis and problems excluded from the cross mapping with NANDA-I, the 63 terms (73.3%) related to surgery/procedure were the most common. @*Conclusion@#It is meaningful that multi-tertiary hospital nursing diagnosis and problems were standardized and cross mapping with standard nursing terminologies was performed. As for the method of applying standardized nursing terminologies in nursing practice, it is appropriate to use several standardized nursing terminologies complementarily.

The First Korean Family with Hemoglobin-M Milwaukee-2 Leading to Hereditary Methemoglobinemia

Hemoglobin M (HbM) is a group of abnormal hemoglobin variants that form methemoglobin, which leads to cyanosis and hemolytic anemia. HbM-Milwaukee-2 is a rare variant caused by the point mutation CAC>TAC on codon 93 of the hemoglobin subunit beta (HBB) gene, resulting in the replacement of histidine by tyrosine. We here report the first Korean family with HbM-Milwaukee-2, whose diagnosis was confirmed by gene sequencing. A high index of suspicion for this rare Hb variant is necessary in a patient presenting with cyanosis since childhood, along with methemoglobinemia and a family history of cyanosis.

A Comparison of Retinal Thickness Changes According to Initial Optic Disc Edema in Optic Neuritis Patients

Purpose@#To compare early changes in the macular retinal nerve fiber layer (mRNFL) and ganglion cell-inner plexiform layer (mGCIPL) thicknesses according to the severity of initial optic disc edema in optic neuritis patients using swept-source optical coherence tomography (SS-OCT). @*Methods@#We retrospectively reviewed 18 eyes of patients diagnosed with naïve optic neuritis along with optic disc edema who underwent SS-OCT. The central thickness of the optic nerve head and the peripapillary retinal thickness were measured at the initial visit. To quantitate the degree of initial optic disc edema, we calculated the difference of each measurement between the affected eye and the normal fellow eye. The mRNFL and mGCIPL thicknesses were measured at the initial visit and at the 1 month follow-up. The association between changes in mRNFL and mGCIPL thicknesses at the 1 month follow-up and the severity of initial optic disc edema were evaluated. @*Results@#In the affected eye, the mGCIPL thickness was reduced at 1 month. The central thickness of the optic nerve head at the initial visit correlated with the reduction in the temporal mGCIPL at 1 month (R = 0.648, p = 0.045). Furthermore, thicker nasal peripapillary retinal thickness at the initial visit correlated with a reduction in nasal (R = 0.659, p = 0.038) and temporal (R = 0.774, p = 0.009) mGCIPL at 1 month. Thicker temporal peripapillary retinal thickness at the initial visit correlated with reduction in the nasal (R = 0.646, p = 0.044) and temporal (R = 0.760, p = 0.011) mGCIPL at 1 month. @*Conclusions@#In optic neuritis patients with optic disc edema, severe optic disc edema, evaluated by peripapillary retinal thickness and central thickness of the optic nerve at the initial visit was associated with a reduced temporal mGCIPL thickness at 1 month. This study suggested that initially severe optic disc edema in optic neuritis patients can predict a rapid decline in the mGCIPL.

Effects of the Syzygium aromaticum L. Extract on antioxidation and inhibition of matrix metalloproteinase in human dermal fibroblast

Objective: To investigate cosmetic potential of Syzygium aromaticum L. (S. aromaticum L.) and to determine its antioxidant and anti-wrinkling effects. Methods: Using high-performance liquid chromatography, eugenol component was quantitated. The antioxidant activity of S. aromaticum L. was analyzed by 2,2-diphenyl-1-picrylhydrazyl radical scavenging and superoxide dismutase like activities. To determine cell viability, elastase and matrix metalloproteinase-1 (MMP-1) activity, human dermal fibroblasts (HS68) were treated with S. aromaticum L. The inhibitory effect of S. aromaticum L. on tumor necrosis factor alpha induced MMPs expression in HS68 was analyzed by realtime-PCR. Results: The eugenol content was confirmed in S. aromaticum L. S. aromaticum L. was observed to have high 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and superoxide dismutase like activity. S. aromaticum L. had no cytotoxicity against the HS68 and dose-dependently increased elastase inhibition. Moreover, S. aromaticum L. significantly decreased MMP-1 content and inhibited gene levels of MMP-1, MMP-2, MMP-3 and MMP-9. Conclusions: The findings suggest that S. aromaticum L. has great potential as a cosmeceutical ingredient with antioxidant and anti-wrinkling effects.

A Case of Congenital Hepatoblastoma Presented with Hepatic Osteodystrophy Complicated by Multiple Bone Fractures / 임상소아혈액종양

Hepatic osteodystrophy is frequent complication in patients with chronic liver disease, particularly with chronic cholestasis. We report a male infant with congenital hepatoblastoma, who had osteodystrophy complicated by multiple bone fractures despite adequate supplementation of fat-soluble vitamins including vitamin D. He was born by Caesarean section because of a 7 cm–sized abdominal mass detected by prenatal ultrasonography. The pathologic diagnosis was hepatoblastoma, PRETEXT staging III or IV. Whole body bone scan at the time of diagnosis showed no abnormal uptake. Oral vitamin D3 of 2,000 IU/day was administered with other fat-soluble vitamins. Serum direct bilirubin level gradually increased up to 28.9 mg/dL at postnatal 6 days and was above 5 mg/dL until 110 days of age. Bony changes consistent with rickets became apparent in left proximal humerus since 48 days of age, and multiple bone fractures developed thereafter. With resolving cholestasis by chemotherapy, his bony lesions improved gradually after add-on treatment of bisphosphonate and parenteral administration of vitamin D with calcium. High level of suspicion and prevention of osteodystrophy is needed in patients with hepatoblastoma, especially when cholestasis persists.

Chronic Recurrent Methicillin Resistant Staphylococcus Hemolyticus Endophthalmitis after Cataract Surgery

PURPOSE: To report a case of recurrent endophthalmitis due to methicillin resistant Staphylococcus hemolyticus after phacoemulsification and posterior chamber intraocular lens (IOL) implantation. CASE SUMMARY: A 76-year-old female visited our outpatient clinic with decreased vision 40 days after uncomplicated cataract surgery in her right eye. At the visit, anterior chamber inflammation and cloudy fluid between the posterior capsule and IOL were observed. Uveitis due to residual cortex of lens or capsular block syndrome was suspected, so YAG laser capsulotomy and subconjunctival injection of dexamethasone were performed. Two days later, hypopyon and vitreous opacity were seen. The patient underwent an emergency vitrectomy and intravitreal antibiotic injection with suspicion of bacterial endophthalmitis. The culture was negative. Twenty days after the vitrectomy, anterior chamber inflammation and vitreous opacity developed. The recurrence of endophthalmitis was suspected due to infection by bacteria in the surrounding tissue of the IOL, so the patient underwent an IOL and lens capsule removal with intravitreal antibiotic injection. At this time, the culture revealed methicillin resistant staphylococcus hemolyticus. Systemic and topical vancomycin was then administered, resulting in decreased inflammation. Twenty days after the IOL removal, decreased vision, anterior chamber inflammation, and vitreous opacity developed. Endophthalmitis was decreased by intravitreal antibiotic injection and topical antibiotic treatment. CONCLUSIONS: Methicillin resistant staphylococcus hemolyticus should be considered in the differential diagnosis of chronic recurrent endophthalmitis after cataract surgery.

Longevity and Stress Resistant Property of 6-Gingerol from Zingiber officinale Roscoe in Caenorhabditis elegans

In order to discover lifespan-extending compounds made from natural resources, activity-guided fractionation of Zingiber officinale Roscoe (Zingiberaceae) ethanol extract was performed using the Caenorhabditis elegans (C. elegans) model system. The compound 6-gingerol was isolated from the most active ethyl acetate soluble fraction, and showed potent longevity-promoting activity. It also elevated the survival rate of worms against stressful environment including thermal, osmotic, and oxidative conditions. Additionally, 6-gingerol elevated the antioxidant enzyme activities of C. elegans, and showed a dose-depend reduction of intracellular reactive oxygen species (ROS) accumulation in worms. Further studies demonstrated that the increased stress tolerance of 6-gingerol-mediated worms could result from the promotion of stress resistance proteins such as heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). The lipofuscin levels in 6-gingerol treated intestinal worms were decreased in comparison to the control group. No significant 6-gingerol-related changes, including growth, food intake, reproduction, and movement were noted. These results suggest that 6-gingerol exerted longevity-promoting activities independently of these factors and could extend the human lifespan.

Anaphase-Promoting Complex 7 is a Prognostic Factor in Human Colorectal Cancer

PURPOSE: The anaphase-promoting complex (APC) is a multiprotein complex with E3 ubiquitin ligase activity and is required for ubiquitination of securin and cyclin-B. Several APC-targeting molecules are reported to be oncogenes. Dysregulation of APC may be associated with tumorigenesis. This study examines the relationship between APC expression and clinicopathological factors and evaluates the possibility of an aberrant APC function in colorectal carcinomas (CRCs). METHODS: To determine whether the loss of APC7 expression is related to tumorigenesis, we used tissue micro-arrays in 114 resected CRCs to scrutinize the expressions of APC7 and Ki-67 immunohistochemistry and to find relations with clinocopathologic parameters. The expression of APC7 was defined as positive for summed scores of staining intensities from 0 to 3+. RESULTS: Forty-four cases (67.7%) of colon cancer and 38 cases (77.6%) of rectal cancer showed immunopositive reactions to APC. The grade of APC expression was not statistically correlated with tumor location, age, T or TNM stage, or differentiation. However, the expression of APC did correlate with the expression of Ki-67 and to the tumor recurrent. Higher APC expression showed the better 5-year overall survival rate in 74% of grades 2, 3 groups (high expression) than 57% of grades 0, 1 groups (lower expression) respectively (P = 0.042). CONCLUSION: Positive APC expression may be a good prognostic factor for patients with CRC, and the loss of APC expression in tumor tissue may be related with the risk for recurrence and a poor survival rate compared to high APC expression. Further study of APC in controlling the cell cycle as aberrant function in CRC is needed.

Rapid generation of OPC-like cells from human pluripotent stem cells for treating spinal cord injury

Remyelination via the transplantation of oligodendrocyte precursor cells (OPCs) has been considered as a strategy to improve the locomotor deficits caused by traumatic spinal cord injury (SCI). To date, enormous efforts have been made to derive OPCs from human pluripotent stem cells (hPSCs), and significant progress in the transplantation of such cells in SCI animal models has been reported. The current methods generally require a long period of time (>2 months) to obtain transplantable OPCs, which hampers their clinical utility for patients with SCI. Here we demonstrate a rapid and efficient method to differentiate hPSCs into neural progenitors that retain the features of OPCs (referred to as OPC-like cells). We used cell sorting to select A2B5-positive cells from hPSC-derived neural rosettes and cultured the selected cells in the presence of signaling cues, including sonic hedgehog, PDGF and insulin-like growth factor-1. This method robustly generated neural cells positive for platelet-derived growth factor receptor-α (PDGFRα) and NG2 (~90%) after 4 weeks of differentiation. Behavioral tests revealed that the transplantation of the OPC-like cells into the spinal cords of rats with contusive SCI at the thoracic level significantly improved hindlimb locomotor function. Electrophysiological assessment revealed enhanced neural conduction through the injury site. Histological examination showed increased numbers of axon with myelination at the injury site and graft-derived myelin formation with no evidence of tumor formation. Our method provides a cell source from hPSCs that has the potential to recover motor function following SCI.

Chronic hepatitis C healed by peginterferon-α and rivabirin treatment after kidney transplantation / 영남의대학술지

Hepatitis C virus (HCV) infection is present in a high proportion of patients with kidney transplantation. Compared with uninfected kidney transplant recipients, HCV infected kidney recipient have higher prevalence of liver disease and worse allograft survival after transplantation. Interferon monotherapy before transplantation is standard therapy for HCV-infected kidney transplant candidates. If HCV infection is discovered after transplantation, interferon monotherapy is considered due to the limited critical situation. However, in this patient, who was a kidney recipient, HCV infection was treated after kidney transplantation with peginterferon-α and rivabirin. As a result, the patient achieved sustained virologic response.

A 45-Year-Old Man With Recurrent Dyspnea and Hemoptysis during Exercise: Exercise-Induced Pulmonary Hemorrhage/Edema / 결핵및호흡기질환

A 45-year-old man presented with dyspnea and hemoptysis during exercise. A chest computed tomography (CT) revealed multifocal diffuse patchy ground glass opacity and interlobular septal thickening in both the lungs. Permeability pulmonary edema or pulmonary hemorrhage was suspected. Serologic studies for autoimmune disorders and vasculitis were negative. There was no laboratory evidence of coagulopathy, other hematopoietic disease or infectious disease. Considering correlation with exercise, we diagnosed exercise-induced pulmonary hemorrhage (EIPH) or exercise-induced pulmonary edema (EIPE). The patient was managed with antifibrinolytics, antibiotics, and antitussive agent. After a week, follow-up chest CT revealed completely resolved pulmonary hemorrhage. About 2 months after the first event, he visited again with dyspnea and hemoptysis during running. In the present study, we report a case of recurrent pulmonary hemorrhage after exercise.

Effects of health and safety problem recognition on small business facility investment

OBJECTIVES: This study involved a survey of the facility investment experiences, which was designed to recognize the importance of health and safety problems, and industrial accident prevention. Ultimately, we hope that small scale industries will create effective industrial accident prevention programs and facility investments. METHODS: An individual survey of businesses' present physical conditions, recognition of the importance of the health and safety problems, and facility investment experiences for preventing industrial accidents was conducted. The survey involved 1,145 business operators or management workers in small business places with fewer than 50 workers in six industrial complexes. RESULTS: Regarding the importance of occupational health and safety problems (OHS), 54.1% said it was "very important". Received technical and financial support, and industrial accidents that occurred during the past three years were recognized as highly important for OHS. In an investigation regarding facility investment experiences for industrial accident prevention, the largest factors were business size, greater numbers of industrial accidents, greater technical and financial support received, and greater recognition of the importance of the OHS. The related variables that decided facility investment for industry accident prevention in a logistic regression analysis were the experiences of business facilities where industrial accidents occurred during the past three years, received technical and financial support, and recognition of the OHS. Those considered very important were shown to be highly significant. CONCLUSIONS: Recognition of health and safety issues was higher when small businesses had experienced industrial accidents or received financial support. The investment in industrial accidents was greater when health and safety issues were recognized as important. Therefore, the goal of small business health and safety projects is to prioritize health and safety issues in terms of business management and recognition of importance. Therefore, currently various support projects are being conducted. However, there are issues regarding the limitations of the target businesses and inadequacies in maintenance and follow-up. Overall, it is necessary to provide various incentives for onsite participation that can lead to increased recognition of health and safety issues and practical investments, while perfecting maintenance and follow up measures by thoroughly revising existing operating systems.

Tracheal Stenosis after Tracheostomy Treated Successfully with Papillotome Electrocautery / 결핵및호흡기질환

A 39-year-old woman presented with symptoms of dyspnea. Ten years previously, she had received a tracheostomy because of the decision to not continue taking an anticonvulsant drug. Presently, chest computed tomography showed diffuse stenosis and focal web at the cervical trachea. We performed bronchoscopy and found a two-thirds reduction of the upper trachea due to the web-like fibrotic stenosis. Papillotome electrocautery removed the stenotic lesion. Endobronchial electrocautery is a valuable tool with potential for therapy of an endobronchial obstructing airway lesion. We report this case to introduce the successful treatment with papillotome electrocautery.

Disease-specific induced pluripotent stem cells: a platform for human disease modeling and drug discovery

The generation of disease-specific induced pluripotent stem cell (iPSC) lines from patients with incurable diseases is a promising approach for studying disease mechanisms and drug screening. Such innovation enables to obtain autologous cell sources in regenerative medicine. Herein, we report the generation and characterization of iPSCs from fibroblasts of patients with sporadic or familial diseases, including Parkinson's disease (PD), Alzheimer's disease (AD), juvenile-onset, type I diabetes mellitus (JDM), and Duchenne type muscular dystrophy (DMD), as well as from normal human fibroblasts (WT). As an example to modeling disease using disease-specific iPSCs, we also discuss the previously established childhood cerebral adrenoleukodystrophy (CCALD)- and adrenomyeloneuropathy (AMN)-iPSCs by our group. Through DNA fingerprinting analysis, the origins of generated disease-specific iPSC lines were identified. Each iPSC line exhibited an intense alkaline phosphatase activity, expression of pluripotent markers, and the potential to differentiate into all three embryonic germ layers: the ectoderm, endoderm, and mesoderm. Expression of endogenous pluripotent markers and downregulation of retrovirus-delivered transgenes [OCT4 (POU5F1), SOX2, KLF4, and c-MYC] were observed in the generated iPSCs. Collectively, our results demonstrated that disease-specific iPSC lines characteristically resembled hESC lines. Furthermore, we were able to differentiate PD-iPSCs, one of the disease-specific-iPSC lines we generated, into dopaminergic (DA) neurons, the cell type mostly affected by PD. These PD-specific DA neurons along with other examples of cell models derived from disease-specific iPSCs would provide a powerful platform for examining the pathophysiology of relevant diseases at the cellular and molecular levels and for developing new drugs and therapeutic regimens.

Neuron-Like Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells

PURPOSE: Mesenchymal stem cells (MSCs) are multipotent and give rise to distinctly differentiated cells from all three germ layers. Neuronal differentiation of MSC has great potential for cellular therapy. We examined whether the cluster of mechanically made, not neurosphere, could be differentiated into neuron-like cells by growth factors, such as epidermal growth factor (EGF), hepatocyte growth factor (HGF), and vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: BMSCs grown confluent were mechanically separated with cell scrapers and masses of separated cells were cultured to form cluster BMSCs. As described here cluster of BMSCs were differentiated into neuron-like cells by EGF, HGF, and VEGF. Differentiated cells were analyzed by means of phase-contrast inverted microscopy, reverse transcriptase-polymerase chain reaction (RT-PCR), immunofluorescence, and immunocytochemistry to identify the expression of neural specific markers. RESULTS: For the group with growth factors, the shapes of neuron-like cells was observable a week later, and two weeks later, most cells were similar in shape to neuron-like cells. Particularly, in the group with chemical addition, various shapes of filament structures were seen among the cells. These culture conditions induced MSCs to exhibit a neural cell phenotype, expressing several neuro-glial specific markers. CONCLUSION: bone marrow-derived mesenchymal stem cells (BMSCs) could be easily induced to form clusters using mechanical scraping, not neurospheres, which in turn could differentiate further into neuron-like cells and might open an attractive possibility for clinical cell therapy for neurodegenerative diseases. In the future, we consider that neuron-like cells differentiated from clusters of BMSCs are needed to be compared and analyzed on a physiological and molecular biological level with preexisting neuronal cells, and studies on the possibility of their transplantation and differentiation capability in animal models are further required.