Publications by authors named "Ji Il Kim"

Article Synopsis
  • Researchers studied neural circuits in the brain important for sensorimotor processing and their links to neuropsychiatric disorders using advanced methods involving human pluripotent stem cells.
  • They created specialized four-part "loop assembloids" that mimic key brain regions, allowing for the observation of synchronized neuronal activity and connectivity.
  • This platform is valuable for investigating genetic influences on disorders like autism and Tourette syndrome, revealing unique patterns of neuronal behavior associated with these conditions.
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Neurodevelopment involves the migration, projection, and integration of various cell types across different regions of the nervous system. Assembloids are self-organizing systems formed by the integration of multiple organoids or cell types. Here, we outline the generation and application of assembloids.

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Article Synopsis
  • Abnormal thalamocortical communication can result in neuropsychiatric disorders, with specific genetic variants in the CACNA1G gene linked to conditions like absence seizures, intellectual disability, and schizophrenia.
  • Researchers created a human assembloid model to study the effects of CACNA1G variants on thalamocortical pathways, discovering that a specific variant (M1531V) altered calcium currents in thalamic neurons and increased activity in both thalamic and cortical neurons.
  • Conversely, the loss of CACNA1G was found to disrupt thalamocortical connectivity, leading to heightened spontaneous activity in thalamic neurons and abnormal axon projections, highlighting the importance of multi-cellular models in understanding
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In May-Thurner syndrome (MTS), the left iliac vein is compressed by the right iliac artery, leading to restricted blood flow from the leg to the heart. MTS commonly manifests in young females; however, its occurrence in older adults necessitates verifying the possibility of malignancy. A 77-year-old female experienced leg swelling and discomfort for 1 week.

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Article Synopsis
  • The study focuses on creating human ascending somatosensory assembloids (hASA) from pluripotent stem cells to model the human spinothalamic pathway, which is crucial for transmitting pain and sensory information to the brain.
  • Researchers confirmed the presence of important cell types in the hASA using transcriptomic profiling and demonstrated connections between sensory neurons and thalamic neurons through rabies tracing and calcium imaging.
  • Experiments showed that chemical stimulation led to coordinated neuronal responses, and the disruption of the sodium channel SCN9A, associated with pain insensitivity, affected the synchrony of the network, highlighting the potential of this model for understanding sensory pathways and developing pain therapies
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As basic units of neural networks, ensembles of synapses underlie cognitive functions such as learning and memory. These synaptic engrams show elevated synaptic density among engram cells following contextual fear memory formation. Subsequent analysis of the CA3-CA1 engram synapse revealed larger spine sizes, as the synaptic connectivity correlated with the memory strength.

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Social animals expend considerable energy to maintain social bonds throughout their life. Male and female mice show sexually dimorphic behaviors, yet the underlying neural mechanisms of sociability and their dysregulation during social disconnection remain unknown. Dopaminergic neurons in dorsal raphe nucleus (DRN) is known to contribute to a loneliness-like state and modulate sociability.

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Article Synopsis
  • * This study focused on the mollusk Aplysia, where researchers microinjected a neuropeptide receptor (apATRPR) into neurons that previously did not have the receptor.
  • * The experiments showed that the injected receptor successfully increased neuronal excitability when activated by its ligand, apATRP, confirming the receptor's physiological role in mollusks.
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Chronic kidney disease affects hemostasis in complex ways, producing both thrombotic and hemorrhagic diatheses. These changes may impact patient morbidity and mortality pre-transplantation, as well as allograft survival after kidney transplantation (KT). This study was conducted to analyze changes in hemostatic factors in the early post-KT period.

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Background: Cytomegalovirus (CMV) infection is an important complication after kidney transplantation (KT). Antithymocyte globulin (ATG) increases the risk for CMV infection, and universal prophylaxis is recommended during the first 3 to 6 months after ATG induction in CMV-seropositive recipients. However, following this recommendation is not easy because the cost is high.

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Transplant renal artery stenosis (TRAS) is the most common (1%-23%) vascular complication following kidney transplantation. The aim of this study was to review our experience with an endovascular approach to treat TRAS.We retrospectively reviewed kidney transplant recipients who underwent percutaneous transluminal angioplasty (PTA) due to TRAS in our institute from January 2009 to December 2015.

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Successful adaptation to the environment requires an accurate response to external threats by recalling specific memories. Memory formation and recall require engram cell activity and synaptic strengthening among activated neuronal ensembles. However, elucidation of the underlying neural substrates of associative fear memory has remained limited without a direct interrogation of extinction-induced changes of specific synapses that encode a specific auditory fear memory.

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Article Synopsis
  • Long-term potentiation (LTP) at hippocampal CA1 synapses can be caused by either an increase in the number of AMPA receptors or the conductance of individual channels.
  • Different stimulation methods produce distinct types of LTP: compressed theta burst stimulation increases receptor numbers, while spaced TBS and activated PKA raise single channel conductance.
  • The study highlights that activation of CaMKII is essential for achieving LTP, with PKA also playing a role in certain forms of LTP at these synapses.
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CCCTC-binding factor (CTCF) is a genome organizer that regulates gene expression through transcription and chromatin structure regulation. CTCF also plays an important role during the developmental and adult stages. Cell-specific CTCF deletion studies have shown that a reduction in CTCF expression leads to the development of distinct clinical features and cognitive disorders.

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Purpose: Ultrasound-guided thoracic paravertebral block (TPVB) is an established means for providing postoperative analgesia in thoracic surgery. However, there are conflicting results regarding the efficacy of post-thoracotomy pain management of ultrasound-guided TPVB when compared with that using traditional landmark approach. We therefore conducted a comparative study to evaluate the analgesic efficacy of TPVB when pressure measurement during needle advancement is combined with an ultrasound-guided approach.

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Neur1 and Neur2, mouse homologs of the Drosophila neur gene, consist of two neuralized homology repeat domains and a RING domain. Both Neur1 and Neur2 are expressed in the whole adult brain and encode E3 ubiquitin ligases, which play a crucial role in the Notch signaling pathways. A previous study reported that overexpression of Neur1 enhances hippocampus-dependent memory, whereas the role of Neur2 remains largely unknown.

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Purpose: Isolated distal deep vein thrombosis (IDDVT) is a localized lesion; nonetheless, the risk of proximal vein propagation makes it difficult to decide on the treatment protocol-that is, whether immediate anticoagulation after diagnosis or surveillance via serial imaging should be employed. This study aimed to investigate the appropriate treatment protocol for IDDVT in kidney transplant recipient (KTR).

Methods: Surveillance for venous thromboembolism (VTE) was performed using duplex ultrasonography (DUS) before transplant surgery and at 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year after transplant surgery.

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Background: Bedside insertion of peripherally inserted central catheters (PICCs) has higher rates of malposition than fluoroscopic-guided PICC placement. This study evaluated the success rate of bedside PICC placement, variations in tip location, and risk factors for malposition.

Methods: This retrospective study included patients who underwent bedside PICC placement from January 2013 to September 2014 in a single institution.

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Article Synopsis
  • * A total of 71 ITx procedures were performed, revealing an overall patient survival rate of around 70% after five years, with many patients no longer needing total parenteral nutrition.
  • * The authors call for a multinational registry for ITx recipients, improved referral systems, and a coordinated treatment approach to enhance patient care and outcomes in East Asia.
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Parkinson's disease (PD) is a neurodegenerative disorder that affects the extrapyramidal system, and respiratory dysfunction has also been noted in patients with PD. However, acute upper airway obstruction due to bilateral vocal cord paralysis is a very rare finding in PD. Here, we describe a rare life-threatening respiratory failure caused by bilateral vocal cord paralysis in an elderly woman with PD during emergence from general anesthesia.

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Background: A cancer patient slated for abdominal surgery is considered to be at moderate to high risk for developing venous thromboembolism (VTE), but the incidence is quite low in Korean patients. Most risk assessment models and recommendations for VTE management are from Western reports, however they possibly overestimate the risk of VTE in the Korean population.

Methods: We retrospectively reviewed the medical records of 1966 patients who were diagnosed with abdominal organ cancer and required surgical treatment.

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Background: This study aims to analyze the entire registry of kidney transplant over the past 50 years and understand the clinical significance.

Methods: From the data on 3012 kidney transplants performed at our center between March 1969 and September 2018, we analyzed retrospectively clinical variables.

Results: Until September 2018, there have been 3012 kidney transplants performed.

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Purpose: Renal dysfunction more frequently occurs after intestinal transplantation (ITx) than after heart, lung, or liver transplantation. We provide a clinical analysis of renal function after adult ITx.

Methods: We retrospectively analyzed 8 adult ITx patients who survived for at least 6 months between 2004 and 2018.

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Calcium/Calmodulin-dependent protein kinase II (CaMKII) plays a key role in the molecular mechanism of memory formation. CaMKII is known to be activated specifically in the activated spines during memory formation. However, it is unclear whether the specific activation of CaMKII is necessary for encoding information.

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