Three-dimensional(3D)bioprinting,an effective technique for building cell-laden structures providing native extracellular matrix environments,presents challenges,including inadequate cellular interactions.To address t...Three-dimensional(3D)bioprinting,an effective technique for building cell-laden structures providing native extracellular matrix environments,presents challenges,including inadequate cellular interactions.To address these issues,cell spheroids offer a promising solution for improving their biological functions.Particularly,minispheroids with 50-100μm diameters exhibit enhanced cellular maturation.We propose a one-step minispheroid-forming bioprinting process incorporating electrical stimulation(E-MS-printing).By stimulating the cells,minispheroids with controlled diameters were generated by manipulating the bioink viscosity and stimulation intensity.To validate its feasibility,E-MS-printing process was applied to fabricate an engineered liver model designed to mimic the hepatic lobule unit.E-MS-printing was employed to print the hepatocyte region,followed by bioprinting the central vein using a core-shell nozzle.The resulting constructs displayed native liver-mimetic structures containing minispheroids,which facilitated improved hepatic cell maturation,functional attributes,and vessel formation.Our results demonstrate a new potential 3D liver model that can replicate native liver tissues.展开更多
Mirror neuron system can be activated by observation and execution of an action.It has an important function of action understanding.We investigated brain activations in humans by observing the strength of a hand gras...Mirror neuron system can be activated by observation and execution of an action.It has an important function of action understanding.We investigated brain activations in humans by observing the strength of a hand grasp using functional magnetic resonance imaging.Twenty right-handed healthy individuals,consisting of 10 males and 10 females,aged 22.40 ± 2.04 years,were recruited into this study from September to November 2017 via posters.Light hand grasp task video showed a hand lightly grasping and releasing a ball repeatedly.Powerful hand grasp task video showed a hand tightly grasping and releasing a ball repeatedly.Functional magnetic resonance imaging block design paradigm comprised five stimulation blocks alternating with five baseline blocks.Stimulation blocks were presented with two stimulus tasks,consisting of a light grasp and a powerful grasp.Region of interest was defined around the inferior parietal lobule,inferior frontal gyrus,and superior temporal sulcus which have been called mirror neuron system.The inferior parietal lobule,fusiform,postcentral,occipital,temporal,and frontal gyri were activated during light and powerful grasp tasks.The BOLD signal response of a powerful grasp was stronger than that of a light grasp.These results suggest that brain activation of the inferior parietal lobule,which is the core brain region of the mirror neuron system,was stronger in the powerful grasp task than in the light grasp task.We believe that our results might be helpful for instructing rehabilitation of brain injury.This study was approved by the Institutional Review Board of Daegu Oriental Hospital of Daegu Haany University on September 8,2017 (approval No.DHUMC-D-17020-PRO-01).展开更多
Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and phy...Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and physiological viewpoints. Model A of Weibel in which dichotomously branching airways are incorporated should be used for analyzing gas mixing in conducting and acinar airways. Acinus of Loeschcke is taken as an anatomical gas-exchange unit.Although it is difficult to define functional gas-exchange unit in a way entirely consistent with anatomical structures, acinus of Aschoff may serve as a functional gas-exchange unit in a first approximation. Based on anatomical and physiological perspectives, the multiple inert-gas elimination technique is thought to be highly effective for predicting ventilation-perfusion heterogeneity between acini of Aschoff under steady-state condition. Changes in effective alveolar P_(O2), the most important parameter in classical gas-exchange theory, are coherent with those in mixed alveolar P_(O2) decided from the multiple inert-gas elimination technique. Therefore, effective alveolar-arterial P_(O2) difference is considered useful for assessing gas-exchange abnormalities in lung periphery.However, one should be aware that although alveolar-arterial P_(O2) difference sensitively detects moderately low ventilation-perfusion regions causing hypoxemia, it is insensitive to abnormal gas exchange evoked by very low and high ventilation-perfusion regions. Pulmonary diffusing capacity for CO (D_(LCO))and the value corrected for alveolar volume (V_(AV)), i.e., D_(LCO)/V_(AV) (K_(CO)), are thought to be crucial for diagnosing alveolar-wall damages. D_(LCO)-related parameters have higher sensitivity to detecting abnormalities in pulmonary microcirculation than those in the alveolocapillary membrane. We would like to recommend four categories derived from combining behaviors of D_(LCO) with those of K_(CO) for differential diagnosis on anatomically morbid states in alveolar walls:type-1a展开更多
Epidermoid cysts are benign, developmental, superficial cysts found commonly on the face, trunk and neck. Its presence on the ear lobe is very rare. We shall describe the occurrence of an epidermoid cyst on the auricl...Epidermoid cysts are benign, developmental, superficial cysts found commonly on the face, trunk and neck. Its presence on the ear lobe is very rare. We shall describe the occurrence of an epidermoid cyst on the auricle along with the presence of a dermoid cyst over the occipital scalp and elaborate on the patient presentation, diagnosis, management along with the post-operative follow up.展开更多
Classic respiratory mechanics is a branch of vectorial mechanics, which aims to recognize all forces acting on the respiratory system. Another branch of mechanics, analytical mechanics, has been used for analyzing the...Classic respiratory mechanics is a branch of vectorial mechanics, which aims to recognize all forces acting on the respiratory system. Another branch of mechanics, analytical mechanics, has been used for analyzing the motions of complicated systems with constraints through equilibrium among scalar quantities such as kinetic energy and potential energy. However, until now, there have not been any studies concerning about analytical respiratory mechanics. In this paper, the author has obtained two types of motion equations (linear and nonlinear) for the airflow limitation from formulation of the analytical respiratory mechanics. Reconstructed flow-volume trajectories of the linear equation revealed a new relationship among the slope of the linear portion of trajectory, the coefficient of the dissipation function and the coefficient of the potential function. Reconstructed trajectories of the nonlinear equation suggested that a curved flow-volume trajectory would be caused by the emergence of regional hypoventilated clusters with airtrapped lobules. In conclusion, analytical respiratory mechanics will provide the basis for analyzing the mechanical properties of the respiratory system con cerning pulmonary functional images made by newly developed technologies.展开更多
AIM To clarify the histological changes associated with liver atrophy after percutaneous transhepatic portalembolization(PTPE) in pigs and humans. METHODS As a preliminary study, we performed pathological examinations...AIM To clarify the histological changes associated with liver atrophy after percutaneous transhepatic portalembolization(PTPE) in pigs and humans. METHODS As a preliminary study, we performed pathological examinations of liver specimens from five pigs that had undergone PTPE in a time-dependent model of liver atrophy. In specimens from embolized lobes(EMB) and nonembolized lobes(controls), we measured the portal vein to central vein distance(PV-CV), the area and number of hepatocytes per lobule, and apoptotic activity using the terminal deoxynucleotidyl transferase dU TP nickend labeling assay. Immunohistochemical reactivities were evaluated for light chain 3(LC3) and lysosomal-associated membrane protein 2(LAMP2) as autophagy markers and for glutamine synthetase and cytochrome P450 2 E1(CYP2 E1) as metabolic zonation markers. Samples from ten human livers taken 20-36 d after PTPE were similarly examined. RESULTS PV-CVs and lobule areas did not differ between EMB and controls at day 0, but were lower in EMB than in controls at weeks 2, 4, and 6(P ≤ 0.001). Hepatocyte numbers were not significantly reduced in EMB at day 0 and week 2 but were reduced at weeks 4 and 6(P ≤ 0.05). Apoptotic activity was higher in EMB than in controls at day 0 and week 4. LC3 and LAMP2 staining peaked in EMB at week 2, with no significant difference between EMB and controls at weeks 4 and 6. Glutamine synthetase and CYP2 E1 zonation in EMB at weeks 2, 4, and 6 were narrower than those in controls. Human results were consistent with those of porcine specimens. CONCLUSION The mechanism of liver atrophy after PTPE has two histological phases: Hepatocellular atrophy is likely caused by autophagy in the first 2 wk and apoptosis thereafter.展开更多
目的应用静息态功能磁共振(resting state function magnetic resonance imaging,rs-fMRI)观察高压氧治疗(hyperbaric oxygen therapy,HBOT)对改善创伤性颅脑损伤(traumatic brain injury,TBI)患者执行功能(executive function,EF)的作...目的应用静息态功能磁共振(resting state function magnetic resonance imaging,rs-fMRI)观察高压氧治疗(hyperbaric oxygen therapy,HBOT)对改善创伤性颅脑损伤(traumatic brain injury,TBI)患者执行功能(executive function,EF)的作用。方法选取50例TBI后EF障碍患者,按照数字表法随机分为HBO组(n=25)和对照组(n=25),对照组接受常规基础治疗及EF康复训练,HBO组在对照组治疗的基础上加用HBO治疗,HBOT压力0.2 MPa,105 min/次,1次/d,5 d/周,共20次。所有受试者在治疗前后均应用画钟测验、中文版Stroop色词测验、韦氏成人智力量表相似性评分测验EF,同时采用rs-fMRI技术结合ReHo、ALFF分析方法,观察HBOT对TBI患者的大脑各区域代谢活动的强度、局部脑区神经元细胞同步性以及协调性改变情况,分析影像学数据与神经心理学量表评估结果的相关性。结果干预后2组间比较,HBO组Stroop-A耗时、Stroop-C耗时与正确阅读数及干扰效应评分改善程度明显优于对照组,差异有统计学意义(P<0.05)。不同干预后,2组TBI患者共同脑区在顶上小叶ALFF值差异有统计学意义(P<0.05)。相关性分析发现,HBO组差异脑区顶上小叶与干扰时间呈正相关(P<0.05)。HBO组差异脑区额中回与卡片A的正确阅读数呈正相关(P<0.05)。结论EF康复训练、HBO联合EF康复训练均能不同程度地改善TBI患者的EF;HBO联合EF康复训练对改善TBI患者的EF效果更好;HBOT改善TBI患者EF可能是通过调节额中回、顶上小叶脑区的自发活动及局部一致性而实现的。展开更多
基金supported by a grant from the Ministry of Trade,Industry&Energy(MOTIE,Korea)under Industrial Technology Innovation Program(20009652:Technology on commercialization and materials of Bioabsorbable Hydroxyapatite less than 1μm in size)supported by the“Korea National Institute of Health”research project(2022ER130501).
文摘Three-dimensional(3D)bioprinting,an effective technique for building cell-laden structures providing native extracellular matrix environments,presents challenges,including inadequate cellular interactions.To address these issues,cell spheroids offer a promising solution for improving their biological functions.Particularly,minispheroids with 50-100μm diameters exhibit enhanced cellular maturation.We propose a one-step minispheroid-forming bioprinting process incorporating electrical stimulation(E-MS-printing).By stimulating the cells,minispheroids with controlled diameters were generated by manipulating the bioink viscosity and stimulation intensity.To validate its feasibility,E-MS-printing process was applied to fabricate an engineered liver model designed to mimic the hepatic lobule unit.E-MS-printing was employed to print the hepatocyte region,followed by bioprinting the central vein using a core-shell nozzle.The resulting constructs displayed native liver-mimetic structures containing minispheroids,which facilitated improved hepatic cell maturation,functional attributes,and vessel formation.Our results demonstrate a new potential 3D liver model that can replicate native liver tissues.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(No.2017R1D1A1B03033985to MYL)+1 种基金the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(No.2018R1A5A2025272to MYL)
文摘Mirror neuron system can be activated by observation and execution of an action.It has an important function of action understanding.We investigated brain activations in humans by observing the strength of a hand grasp using functional magnetic resonance imaging.Twenty right-handed healthy individuals,consisting of 10 males and 10 females,aged 22.40 ± 2.04 years,were recruited into this study from September to November 2017 via posters.Light hand grasp task video showed a hand lightly grasping and releasing a ball repeatedly.Powerful hand grasp task video showed a hand tightly grasping and releasing a ball repeatedly.Functional magnetic resonance imaging block design paradigm comprised five stimulation blocks alternating with five baseline blocks.Stimulation blocks were presented with two stimulus tasks,consisting of a light grasp and a powerful grasp.Region of interest was defined around the inferior parietal lobule,inferior frontal gyrus,and superior temporal sulcus which have been called mirror neuron system.The inferior parietal lobule,fusiform,postcentral,occipital,temporal,and frontal gyri were activated during light and powerful grasp tasks.The BOLD signal response of a powerful grasp was stronger than that of a light grasp.These results suggest that brain activation of the inferior parietal lobule,which is the core brain region of the mirror neuron system,was stronger in the powerful grasp task than in the light grasp task.We believe that our results might be helpful for instructing rehabilitation of brain injury.This study was approved by the Institutional Review Board of Daegu Oriental Hospital of Daegu Haany University on September 8,2017 (approval No.DHUMC-D-17020-PRO-01).
文摘Many problems regarding structure-function relationships have remained unsolved in the field of respiratory physiology. In the present review, we highlighted these uncertain issues from a variety of anatomical and physiological viewpoints. Model A of Weibel in which dichotomously branching airways are incorporated should be used for analyzing gas mixing in conducting and acinar airways. Acinus of Loeschcke is taken as an anatomical gas-exchange unit.Although it is difficult to define functional gas-exchange unit in a way entirely consistent with anatomical structures, acinus of Aschoff may serve as a functional gas-exchange unit in a first approximation. Based on anatomical and physiological perspectives, the multiple inert-gas elimination technique is thought to be highly effective for predicting ventilation-perfusion heterogeneity between acini of Aschoff under steady-state condition. Changes in effective alveolar P_(O2), the most important parameter in classical gas-exchange theory, are coherent with those in mixed alveolar P_(O2) decided from the multiple inert-gas elimination technique. Therefore, effective alveolar-arterial P_(O2) difference is considered useful for assessing gas-exchange abnormalities in lung periphery.However, one should be aware that although alveolar-arterial P_(O2) difference sensitively detects moderately low ventilation-perfusion regions causing hypoxemia, it is insensitive to abnormal gas exchange evoked by very low and high ventilation-perfusion regions. Pulmonary diffusing capacity for CO (D_(LCO))and the value corrected for alveolar volume (V_(AV)), i.e., D_(LCO)/V_(AV) (K_(CO)), are thought to be crucial for diagnosing alveolar-wall damages. D_(LCO)-related parameters have higher sensitivity to detecting abnormalities in pulmonary microcirculation than those in the alveolocapillary membrane. We would like to recommend four categories derived from combining behaviors of D_(LCO) with those of K_(CO) for differential diagnosis on anatomically morbid states in alveolar walls:type-1a
文摘Epidermoid cysts are benign, developmental, superficial cysts found commonly on the face, trunk and neck. Its presence on the ear lobe is very rare. We shall describe the occurrence of an epidermoid cyst on the auricle along with the presence of a dermoid cyst over the occipital scalp and elaborate on the patient presentation, diagnosis, management along with the post-operative follow up.
文摘Classic respiratory mechanics is a branch of vectorial mechanics, which aims to recognize all forces acting on the respiratory system. Another branch of mechanics, analytical mechanics, has been used for analyzing the motions of complicated systems with constraints through equilibrium among scalar quantities such as kinetic energy and potential energy. However, until now, there have not been any studies concerning about analytical respiratory mechanics. In this paper, the author has obtained two types of motion equations (linear and nonlinear) for the airflow limitation from formulation of the analytical respiratory mechanics. Reconstructed flow-volume trajectories of the linear equation revealed a new relationship among the slope of the linear portion of trajectory, the coefficient of the dissipation function and the coefficient of the potential function. Reconstructed trajectories of the nonlinear equation suggested that a curved flow-volume trajectory would be caused by the emergence of regional hypoventilated clusters with airtrapped lobules. In conclusion, analytical respiratory mechanics will provide the basis for analyzing the mechanical properties of the respiratory system con cerning pulmonary functional images made by newly developed technologies.
基金Supported by National Cancer Center Research and Development Fund(23-A-35)
文摘AIM To clarify the histological changes associated with liver atrophy after percutaneous transhepatic portalembolization(PTPE) in pigs and humans. METHODS As a preliminary study, we performed pathological examinations of liver specimens from five pigs that had undergone PTPE in a time-dependent model of liver atrophy. In specimens from embolized lobes(EMB) and nonembolized lobes(controls), we measured the portal vein to central vein distance(PV-CV), the area and number of hepatocytes per lobule, and apoptotic activity using the terminal deoxynucleotidyl transferase dU TP nickend labeling assay. Immunohistochemical reactivities were evaluated for light chain 3(LC3) and lysosomal-associated membrane protein 2(LAMP2) as autophagy markers and for glutamine synthetase and cytochrome P450 2 E1(CYP2 E1) as metabolic zonation markers. Samples from ten human livers taken 20-36 d after PTPE were similarly examined. RESULTS PV-CVs and lobule areas did not differ between EMB and controls at day 0, but were lower in EMB than in controls at weeks 2, 4, and 6(P ≤ 0.001). Hepatocyte numbers were not significantly reduced in EMB at day 0 and week 2 but were reduced at weeks 4 and 6(P ≤ 0.05). Apoptotic activity was higher in EMB than in controls at day 0 and week 4. LC3 and LAMP2 staining peaked in EMB at week 2, with no significant difference between EMB and controls at weeks 4 and 6. Glutamine synthetase and CYP2 E1 zonation in EMB at weeks 2, 4, and 6 were narrower than those in controls. Human results were consistent with those of porcine specimens. CONCLUSION The mechanism of liver atrophy after PTPE has two histological phases: Hepatocellular atrophy is likely caused by autophagy in the first 2 wk and apoptosis thereafter.
文摘目的应用静息态功能磁共振(resting state function magnetic resonance imaging,rs-fMRI)观察高压氧治疗(hyperbaric oxygen therapy,HBOT)对改善创伤性颅脑损伤(traumatic brain injury,TBI)患者执行功能(executive function,EF)的作用。方法选取50例TBI后EF障碍患者,按照数字表法随机分为HBO组(n=25)和对照组(n=25),对照组接受常规基础治疗及EF康复训练,HBO组在对照组治疗的基础上加用HBO治疗,HBOT压力0.2 MPa,105 min/次,1次/d,5 d/周,共20次。所有受试者在治疗前后均应用画钟测验、中文版Stroop色词测验、韦氏成人智力量表相似性评分测验EF,同时采用rs-fMRI技术结合ReHo、ALFF分析方法,观察HBOT对TBI患者的大脑各区域代谢活动的强度、局部脑区神经元细胞同步性以及协调性改变情况,分析影像学数据与神经心理学量表评估结果的相关性。结果干预后2组间比较,HBO组Stroop-A耗时、Stroop-C耗时与正确阅读数及干扰效应评分改善程度明显优于对照组,差异有统计学意义(P<0.05)。不同干预后,2组TBI患者共同脑区在顶上小叶ALFF值差异有统计学意义(P<0.05)。相关性分析发现,HBO组差异脑区顶上小叶与干扰时间呈正相关(P<0.05)。HBO组差异脑区额中回与卡片A的正确阅读数呈正相关(P<0.05)。结论EF康复训练、HBO联合EF康复训练均能不同程度地改善TBI患者的EF;HBO联合EF康复训练对改善TBI患者的EF效果更好;HBOT改善TBI患者EF可能是通过调节额中回、顶上小叶脑区的自发活动及局部一致性而实现的。
