Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 14 de 14
Filtre
1.
International Journal of Stem Cells ; : 279-286, 2020.
Article | WPRIM | ID: wpr-834295

Résumé

A human cell-based liver model capable of long-term expansion and mature hepatic function is a fundamental requirement for pre-clinical drug development. We previously established self-renewing and functionally mature human pluripotent stem cell-derived liver organoids as an alternate to primary human hepatocytes. In this study, we tested long-term prolonged culture of organoids to increase their maturity. Organoid growing at the edge of Matrigel started to deteriorate two weeks after culturing, and the expression levels of the functional mature hepatocyte marker ALB were decreased at four weeks of culture. Replating the organoids weekly at a 1:2 ratio in fresh Matrigel, resulted in healthier morphology with a thicker layer compared to organoids maintained on the same Matrigel and significantly increased ALB expression until three weeks, although, it decreased sharply at four weeks. The levels of the fetal hepatocyte marker AFP were considerably increased in long-term cultures of organoids. Therefore, we performed serial passaging of organoids, whereby they were mechanically split weekly at a 1:3∼1:5 ratio in fresh Matrigel. The organoids expanded so far over passage 55, or 1 year, without growth retardation and maintained a normal karyotype after long-term cryopreservation. Differentiation potentials were maintained or increased after long-term passaging, while AFP expression considerably decreased after passaging. Therefore, these data demonstrate that organoids can be exponentially expanded by serial passaging, while maintaining long-term functional maturation potential. Thus, hepatic organoids can be a practical and renewable cell source for human cell-based and personalized 3D liver models.

2.
Experimental & Molecular Medicine ; : e344-2017.
Article Dans Anglais | WPRIM | ID: wpr-161486

Résumé

Emerging evidence has emphasized the importance of cancer therapies targeting an abnormal metabolic state of tumor-initiating cells (TICs) in which they retain stem cell-like phenotypes and nicotinamide adenine dinucleotide (NAD⁺) metabolism. However, the functional role of NAD⁺ metabolism in regulating the characteristics of TICs is not known. In this study, we provide evidence that the mitochondrial NAD⁺ levels affect the characteristics of glioma-driven SSEA1⁺ TICs, including clonogenic growth potential. An increase in the mitochondrial NAD⁺ levels by the overexpression of the mitochondrial enzyme nicotinamide nucleotide transhydrogenase (NNT) significantly suppressed the sphere-forming ability and induced differentiation of TICs, suggesting a loss of the characteristics of TICs. In addition, increased SIRT3 activity and reduced lactate production, which are mainly observed in healthy and young cells, appeared following NNT-overexpressed TICs. Moreover, in vivo tumorigenic potential was substantially abolished by NNT overexpression. Conversely, the short interfering RNA-mediated knockdown of NNT facilitated the maintenance of TIC characteristics, as evidenced by the increased numbers of large tumor spheres and in vivo tumorigenic potential. Our results demonstrated that targeting the maintenance of healthy mitochondria with increased mitochondrial NAD⁺ levels and SIRT3 activity could be a promising strategy for abolishing the development of TICs as a new therapeutic approach to treating aging-associated tumors.


Sujets)
Glioblastome , Acide lactique , Métabolisme , Mitochondries , NAD , NADP transhydrogenases , Phénotype , Tics , Régulation positive
3.
Journal of Korean Medical Science ; : 590-597, 2016.
Article Dans Anglais | WPRIM | ID: wpr-58422

Résumé

We assessed empathy in medical residents, including factors modifying empathy and the relationship between empathy and burnout. Participants (n = 317 residents, response rate = 42%) from 4 university hospitals completed a socio-demographic questionnaire, the Jefferson Scale of Empathy (Health Professional version, Korean edition), and the Maslach Burnout Inventory (MBI). Participants were classified by medical specialty: “people-oriented specialty” (POS group) or “technology-oriented specialty” (TOS group), with more women in the POS than in the TOS group, χ2 = 14.12, P < 0.001. Being female, married, and having children were factors related to higher empathy (gender, t = -2.129, P = 0.034; marriage, t = -2.078, P = 0.038; children, t = 2.86, P = 0.005). Within specialty group, POS residents showed higher empathy scores in the fourth as compared to the first year, F = 3.166, P = 0.026. Comparing POS and TOS groups by year, fourth year POS residents had significantly higher scores than did fourth year TOS residents, t = 3.349, P = 0.002. There were negative correlations between empathy scores and 2 MBI subscales, emotional exhaustion (EE) and depersonalization (DP). Additionally, first year POS residents had higher DP scores than did first year TOS residents, t = 2.183, P = 0.031. We suggest that factors important for empathy are type of medical specialty, marriage, siblings, and children. Burnout state may be related to decreasing empathy.


Sujets)
Adulte , Enfant , Femelle , Humains , Mâle , Épuisement professionnel , Éducation de l'enfant , Démographie , Dépersonnalisation , Empathie , Hôpitaux universitaires , Internat et résidence , Mariage , Médecins/psychologie , Facteurs sexuels , Enquêtes et questionnaires
4.
Journal of the Korean Society of Biological Psychiatry ; : 46-54, 2013.
Article Dans Coréen | WPRIM | ID: wpr-725239

Résumé

OBJECTIVES: Non-major depression with fewer symptoms than required for a Diagnostic and Statistical Manual of Mental Disorders-4th edition diagnosis of major depressive disorder (MDD) has consistently been found to be associated with functional impairment. In this study, we aim to estimate the cognitive impairment and the quality of life in elderly patients with subsyndromal depression (SSD) compared with non-depressive elderly (NDE). METHODS: The Korean version of Mini International Neuropsychiatric Interview was administered to 194 outpatients with depression and 108 normal controls. SSD is defined as having five or more current depressive symptoms with core depressive symptoms (depressive mood or loss of interest or pleasure) during more than half a day and more than seven days over two weeks. Depression was evaluated by the Korean form of Geriatric Depression Scale of a 15-item short version. Global cognition was assessed by Mini-Mental State Examination in the Korean version of CERAD assessment packet (MMSE-KC). Subjective cognitive impairment was assessed by the Subjective Memory Complaint Questionnaire. Quality of life was evaluated by the Korean Version of Short-Form 36-Item Health Survey. RESULTS: The mean score of the MMSE-KC in the SSD group was lower than that in the NDE group with adjustment for age, gender, and education [F = 4.270, p = 0.04, analysis of covariance (ANCOVA)]. If we defined those having Z-score of MMSE-KC < -1.5 as a high risk group of cognitive impairment, the odds ratio for the high risk group of cognitive impairment was 1.86 [95% confidence intervals (CI) 1.04-3.34] in SSD and 7.57 (95% CI 3.50-16.40) in MDD compared to NDE. The scores of physical component summary (F = 9.274, p = 0.003, ANCOVA) and mental component summary (F = 53.166, p < 0.001, ANCOVA) in the SSD group were lower than those in the NDE group with adjustment for age, gender, and education. CONCLUSIONS: The subjects with SSD, as well as those with MDD, showed impairment of global cognition and also experienced low quality of life in both physical and mental aspects, compared to the NDE group.


Sujets)
Sujet âgé , Humains , Cognition , Dépression , Trouble dépressif majeur , Mémoire , Odds ratio , Patients en consultation externe , Qualité de vie , Sulfadiazine d'argent , Enquêtes et questionnaires
5.
Anesthesia and Pain Medicine ; : 13-15, 2013.
Article Dans Coréen | WPRIM | ID: wpr-119330

Résumé

Complex regional pain syndrome (CRPS) is a chronic painful condition that may arise in the site of an earlier injury or operation to a limb. Like all chronic painful condition, it is associated with depressed mood. Electroconvulsive therapy (ECT) is a procedure when traditional management with systemic medications, nerve blocks, and behavioral pain management were unsuccessful. ECT has been used in the treatment of chronic pain for over 50 years. CRPS and comorbid depression have also been treated successfully with ECT. However, not much has been done to clarify the ECT target in patients, whether the pain or the depression. We report a case of intractable chronic regional pain syndrome with secondary depression in which both of that were treated successfully with an initial ECT course.


Sujets)
Humains , Douleur chronique , Dépression , Électroconvulsivothérapie , Membres , Bloc nerveux , Gestion de la douleur
6.
Journal of the Korean Academy of Child and Adolescent Psychiatry ; : 13-20, 2013.
Article Dans Coréen | WPRIM | ID: wpr-61536

Résumé

Neuroleptic malignant syndrome (NMS) is a severe iatrogenic complication of treatment with antipsychotic medication. The aim of this review is to provide the clinical characteristics and treatments of children and adolescents with NMS. Searches were conducted in Medline, Korean studies Information Service System (KISS), and Research Information Service System (RISS). Sixteen case reports and two review articles were selected in Medline, and two Korean cases reported in department of emergency medicine and pediatrics were selected from RISS. Heterogeneous and atypical presentations of NMS were observed in children and adolescents. Some noticeable differences were observed between adult patients and child patients with NMS. In addition, symptom presentations related to atypical antipsychotic agents differed from those of typical ones. In treatment, bromocriptine and benzodiazepine were recommended for management of symptoms. In particular, electroconvulsive therapy (ECT) was a useful treatment option. For prevention and early detection of NMS in children and adolescents, evaluation of risk factors and understanding of diagnostic features of NMS are very important.


Sujets)
Adolescent , Adulte , Enfant , Humains , Neuroleptiques , Benzodiazépines , Bromocriptine , Électroconvulsivothérapie , Médecine d'urgence , Services d'information , Syndrome malin des neuroleptiques , Pédiatrie , Facteurs de risque
7.
The Korean Journal of Pain ; : 142-147, 2013.
Article Dans Anglais | WPRIM | ID: wpr-31287

Résumé

BACKGROUND: Medical doctors who perform C-arm fluoroscopy-guided procedures are exposed to X-ray radiation. Therefore, radiation-protective shields are recommended to protect these doctors from radiation. For the past several years, these protective shields have sometimes been used without regular inspection. The aim of this study was to investigate the degree of damage to radiation-protective shields in the operating room. METHODS: This study investigated 98 radiation-protective shields in the operation rooms of Konkuk University Medical Center and Jeju National University Hospital. We examined whether these shields were damaged or not with the unaided eye and by fluoroscopy. RESULTS: There were seventy-one aprons and twenty-seven thyroid protectors in the two university hospitals. Fourteen aprons (19.7%) were damaged, whereas no thyroid protectors (0%) were. Of the twenty-six aprons, which have been used since 2005, eleven (42.3%) were damaged. Of the ten aprons, which have been used since 2008, none (0%) was damaged. Of the twenty-three aprons that have been used since 2009, two (8.7%) of them were damaged. Of the eight aprons used since 2010, one (12.3%) was damaged. Of the four aprons used since 2011, none (0%) of them were damaged. The most common site of damage to the radiation-protective shields was at the waist of the aprons (51%). CONCLUSIONS: As a result, aprons that have been used for a long period of time can have a higher risk of damage. Radiation-protective shields should be inspected regularly and exchanged for new products for the safety of medical workers.


Sujets)
Centres hospitaliers universitaires , Oeil , Radioscopie , Hôpitaux universitaires , Glande thyroide
8.
The Korean Journal of Pain ; : 148-153, 2013.
Article Dans Anglais | WPRIM | ID: wpr-31286

Résumé

BACKGROUND: C-arm fluoroscope has been widely used to promote more effective pain management; however, unwanted radiation exposure for operators is inevitable. We prospectively investigated the differences in radiation exposure related to collimation in Medial Branch Block (MBB). METHODS: This study was a randomized controlled trial of 62 MBBs at L3, 4 and 5. After the patient was laid in the prone position on the operating table, MBB was conducted and only AP projections of the fluoroscope were used. Based on a concealed random number table, MBB was performed with (collimation group) and without (control group) collimation. The data on the patient's age, height, gender, laterality (right/left), radiation absorbed dose (RAD), exposure time, distance from the center of the field to the operator, and effective dose (ED) at the side of the table and at the operator's chest were collected. The brightness of the fluoroscopic image was evaluated with histogram in Photoshop. RESULTS: There were no significant differences in age, height, weight, male to female ratio, laterality, time, distance and brightness of fluoroscopic image. The area of the fluoroscopic image with collimation was 67% of the conventional image. The RAD (29.9 +/- 13.0, P = 0.001) and the ED at the left chest of the operators (0.53 +/- 0.71, P = 0.042) and beside the table (5.69 +/- 4.6, P = 0.025) in collimation group were lower than that of the control group (44.6 +/- 19.0, 0.97 +/- 0.92, and 9.53 +/- 8.16), resepectively. CONCLUSIONS: Collimation reduced radiation exposure and maintained the image quality. Therefore, the proper use of collimation will be beneficial to both patients and operators.


Sujets)
Femelle , Humains , Mâle , Tables d'opération , Décubitus ventral , Études prospectives , Thorax
9.
The Korean Journal of Pain ; : 51-56, 2013.
Article Dans Anglais | WPRIM | ID: wpr-40589

Résumé

BACKGROUND: The C-arm fluoroscope is an essential tool for the intervention of pain. The aim of this study was to investigate the radiation exposure experienced by the hand and chest of pain physicians during C-arm fluoroscopy-guided procedures. METHODS: This is a prospective study about radiation exposure to physicians during transforaminal epidural steroid injection (TFESI) and medial branch block (MBB). Four pain physicians were involved in this study. Data about effective dose (ED) at each physician's right hand and left side of the chest, exposure time, radiation absorbed dose (RAD), and the distance from the center of the X-ray field to the physician during X-ray scanning were collected. RESULTS: Three hundred and fifteen cases were included for this study. Demographic data showed no significant differences among the physicians in the TFESIs and MBBs. In the TFESI group, there was a significant difference between the ED at the hand and chest in all the physicians. In physician A, B and C, the ED at the chest was more than the ED at the hand. The distance from the center of the X-ray field to physician A was more than that of the other physicians, and for the exposure time, the ED and RAD in physician A was less than that of the other physicians. In the MBB group, there was no difference in the ED at the hand and chest, except for physician D. The distance from the center of the X-ray field to physician A was more than that of the other physicians and the exposure time in physician A was less than that of the other physicians. CONCLUSIONS: In conclusion, the distance from the radiation source, position of the hand, experience and technique can correlate with the radiation dose.


Sujets)
Main , Études prospectives , Radioprotection , Thorax
10.
Laboratory Animal Research ; : 255-263, 2012.
Article Dans Anglais | WPRIM | ID: wpr-192523

Résumé

Gangliosides are ubiquitous components of the membranes of mammalian cells that are thought to play important roles in various cell functions such as cell-cell interaction, cell adhesion, cell differentiation, growth control, and signaling. However, the role that gangliosides play in the immune rejection response after xenotransplantation is not yet clearly understood. In this study, the regulatory effects of human leukocytes on ganglioside expression in primary cultured micro-pig aortic endothelial cells (PAECs) were investigated. To determine the impact of human leukocytes on the expression of gangliosides in PAECs, we performed high-performance thin layer chromatography (HPTLC) in PAECs incubated with FBS, FBS containing human leukocytes, human serum containing human leukocytes, and FBS containing TNF-alpha. Both HPTLC and immunohistochemistry analyses revealed that PAECs incubated with FBS predominantly express the gangliosides GM3, GM1, and GD3. However, the expression of GM1 significantly decreased in PAECs incubated for 5 h with TNF-alpha (10 ng/mL), 10% human serum containing human leukocytes, and 10% FBS containing human leukocytes. Taken together, these results suggest that human leukocytes induced changes in the expression profile of ganglioside GM1 similar to those seen upon treatment of PAECs with TNF-alpha. This finding may be relevant for designing future therapeutic strategies intended to prolong xenograft survival.


Sujets)
Humains , Adhérence cellulaire , Communication cellulaire , Chromatographie sur couche mince , Cellules endothéliales , Gangliosides , Immunohistochimie , Leucocytes , Membranes , , Transplantation hétérologue , Facteur de nécrose tumorale alpha
11.
Experimental & Molecular Medicine ; : 68-68, 2012.
Article Dans Anglais | WPRIM | ID: wpr-211716

Résumé

No abstract available.

12.
Psychiatry Investigation ; : 134-142, 2012.
Article Dans Anglais | WPRIM | ID: wpr-120920

Résumé

OBJECTIVE: To investigate the prevalence of dementia and its correlates among people with poor socioeconomic status, poor social support systems, and poor performance on the Korean version of the Mini-Mental Status Exam (MMSE-KC). METHODS: We used 2006-2009 data of the National Early Dementia Detection Program (NEDDP) conducted on Jeju Island. This program included all residents >65 years old who were receiving financial assistance. We examined those who performed poorly (standard deviation from the norm of <-1.5) on the MMSE-KC administered as part of the NEDDP, using age-, gender-, and education-adjusted norms for Korean elders. A total of 1708 people were included in this category. RESULTS: The prevalence of dementia in this group was 20.5%. Multivariate logistic regression analysis revealed that the following factors were statistically significantly associated with dementia: age of 80 or older, no education, nursing home residence, and depression. CONCLUSION: The prevalence of dementia is very high among those with lower MMSE-KC scores, and significant correlates include older age, no education, living in a nursing home, and depression. Enhancing lifetime education to improve individuals' cognitive reserves by providing intellectually challenging activities, encouraging living at home rather than in a nursing home, and preventing and treating depression in its early phase could reduce the prevalence of dementia in this population.


Sujets)
Réserve cognitive , Démence , Dépression , Enseignement infirmier , Modèles logistiques , Maisons de repos , Prévalence , Classe sociale
13.
Korean Journal of Anesthesiology ; : 175-178, 2012.
Article Dans Anglais | WPRIM | ID: wpr-83300

Résumé

Intracardiac thrombus during cardiopulmonary bypass (CPB) with full heparinization is very rare but fatal. A 60-year-old woman was scheduled for aortic and mitral valve repairs with a maze procedure for mixed aortic and mitral valvular heart disease with atrial fibrillation. Preoperative transthoracic echocardiography and cardiac computed tomography showed moderate aortic regurgitation and moderate mitral stenosis with regurgitation. There was no intracardiac thrombus. Aortic and mitral valve repairs with the maze procedure were successfully performed without unexpected events. During CPB weaning, a mobile hyper-echogenic mass in the left atrium was detected on transesophageal echocardiography. After cardiac arrest, it was surgically removed. On completion of the operation, weaning from CPB was accomplished uneventfully. The patient fully recovered and was discharged from the intensive care unit on her third postoperative day.


Sujets)
Femelle , Humains , Adulte d'âge moyen , Insuffisance aortique , Fibrillation auriculaire , Pontage cardiopulmonaire , Échocardiographie , Échocardiographie transoesophagienne , Arrêt cardiaque , Atrium du coeur , Valvulopathies , Héparine , Unités de soins intensifs , Valve atrioventriculaire gauche , Sténose mitrale , Thrombose , Sevrage
14.
Experimental & Molecular Medicine ; : 693-701, 2011.
Article Dans Anglais | WPRIM | ID: wpr-190965

Résumé

The human colorectal carcinoma-associated GA733 antigen epithelial cell adhesion molecule (EpCAM) was initially described as a cell surface protein selectively expressed in some myeloid cancers. Gangliosides are sialic acid-containing glycosphingolipids involved in inflammation and oncogenesis. We have demonstrated that treatment with anti-EpCAM mAb and RAW264.7 cells significant inhibited the cell growth in SW620 cancer cells, but neither anti-EpCAM mAb nor RAW264.7 cells alone induced cytotoxicity. The relationship between ganglioside expression and the anti-cancer effects of anti-EpCAM mAb and RAW264.7 was investigated by high-performance thin-layer chromatography. The results demonstrated that expression of GM1 and GD1a significantly increased in the ability of anti-EpCAM to inhibit cell growth in SW620 cells. Anti-EpCAM mAb treatment increased the expression of anti-apoptotic proteins such as Bcl-2, but the expression of pro-apoptotic proteins Bax, TNF-alpha, caspase-3, cleaved caspase-3, and cleaved caspase-8 were unaltered. We observed that anti-EpCAM mAb significantly inhibited the growth of colon tumors, as determined by a decrease in tumor volume and weight. The expression of anti-apoptotic protein was inhibited by treatment with anti-EpCAM mAb, whereas the expression of pro-apoptotic proteins was increased. These results suggest that GD1a and GM1 were closely related to anticancer effects of anti-EpCAM mAb. In light of these results, further clinical investigation should be conducted on anti-EpCAM mAb to determine its possible chemopreventive and/or therapeutic efficacy against human colon cancer.


Sujets)
Animaux , Humains , Mâle , Souris , Anticorps monoclonaux/immunologie , Antigènes néoplasiques/immunologie , Apoptose/effets des médicaments et des substances chimiques , Molécules d'adhérence cellulaire/immunologie , Lignée cellulaire , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Côlon/effets des médicaments et des substances chimiques , Tumeurs du côlon/traitement médicamenteux , Gangliosides/génétique , Régulation de l'expression des gènes tumoraux/effets des médicaments et des substances chimiques , Souris de lignée BALB C
SÉLECTION CITATIONS
Détails de la recherche