Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Methods: Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells. Results: FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells. Conclusion This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.

Purpose: We investigated the results of endoscopic fenestration for deeply located intracranial cysts (DLICs), risk factors for reoperation, and symptom improvement. Materials and Methods: We included 51 patients with DLICs who underwent endoscopic fenestration between November 2006 and October 2022. The median age was 5±20 years (6 days–67 years), and 36 (70.6%) patients were aged <20 years. The male-tofemale ratio was 1.3:1. The ventriculoscope was used to fenestrate the cysts, which had diameters under 4.5 mm. The volume of DLICs was measured separately on serial magnetic resonance imaging, and the patients were followed up for 32±40 months. Results: The mean preoperative volume of DLICs was 63.5±87.4 cm, 3 , which decreased to 23.7±56.2 cm 3postoperatively, with a 45.4%±32.1% decrease rate in 32 months. All DLICs were approached appropriately, avoiding the eloquent areas. Overall, 39 (76.5%) patients showed symptom improvement after a single operation, which was preserved without recurrence, whereas 12 (23.5%) underwent a second operation [shunting (17.6%) or repeating the endoscopic fenestration (5.9%)] owing to symptom aggravation and recurrent cysts. Patients aged <12 months showed 7.4 times more re-operation rate (p>0.046) and 7.4 times less symptom improvement (p=0.038) compared to those with older age. Females showed 6.5 times more re-operation rate (p=0.037) and 7.1 times less symptom improvement (p=0.027) than males. No patients experienced complications such as cerebrospinal fluid leakage, postoperative hemorrhage, or infection. Conclusion Endoscopic surgery is feasible for the treatment of DLICs. Female sex and age <12 months are risk factors for re-operation and less symptom improvement.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Methods: Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells. Results: FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells. Conclusion This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.

Purpose: We investigated the results of endoscopic fenestration for deeply located intracranial cysts (DLICs), risk factors for reoperation, and symptom improvement. Materials and Methods: We included 51 patients with DLICs who underwent endoscopic fenestration between November 2006 and October 2022. The median age was 5±20 years (6 days–67 years), and 36 (70.6%) patients were aged <20 years. The male-tofemale ratio was 1.3:1. The ventriculoscope was used to fenestrate the cysts, which had diameters under 4.5 mm. The volume of DLICs was measured separately on serial magnetic resonance imaging, and the patients were followed up for 32±40 months. Results: The mean preoperative volume of DLICs was 63.5±87.4 cm, 3 , which decreased to 23.7±56.2 cm 3postoperatively, with a 45.4%±32.1% decrease rate in 32 months. All DLICs were approached appropriately, avoiding the eloquent areas. Overall, 39 (76.5%) patients showed symptom improvement after a single operation, which was preserved without recurrence, whereas 12 (23.5%) underwent a second operation [shunting (17.6%) or repeating the endoscopic fenestration (5.9%)] owing to symptom aggravation and recurrent cysts. Patients aged <12 months showed 7.4 times more re-operation rate (p>0.046) and 7.4 times less symptom improvement (p=0.038) compared to those with older age. Females showed 6.5 times more re-operation rate (p=0.037) and 7.1 times less symptom improvement (p=0.027) than males. No patients experienced complications such as cerebrospinal fluid leakage, postoperative hemorrhage, or infection. Conclusion Endoscopic surgery is feasible for the treatment of DLICs. Female sex and age <12 months are risk factors for re-operation and less symptom improvement.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Methods: Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells. Results: FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells. Conclusion This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.

Purpose: We investigated the results of endoscopic fenestration for deeply located intracranial cysts (DLICs), risk factors for reoperation, and symptom improvement. Materials and Methods: We included 51 patients with DLICs who underwent endoscopic fenestration between November 2006 and October 2022. The median age was 5±20 years (6 days–67 years), and 36 (70.6%) patients were aged <20 years. The male-tofemale ratio was 1.3:1. The ventriculoscope was used to fenestrate the cysts, which had diameters under 4.5 mm. The volume of DLICs was measured separately on serial magnetic resonance imaging, and the patients were followed up for 32±40 months. Results: The mean preoperative volume of DLICs was 63.5±87.4 cm, 3 , which decreased to 23.7±56.2 cm 3postoperatively, with a 45.4%±32.1% decrease rate in 32 months. All DLICs were approached appropriately, avoiding the eloquent areas. Overall, 39 (76.5%) patients showed symptom improvement after a single operation, which was preserved without recurrence, whereas 12 (23.5%) underwent a second operation [shunting (17.6%) or repeating the endoscopic fenestration (5.9%)] owing to symptom aggravation and recurrent cysts. Patients aged <12 months showed 7.4 times more re-operation rate (p>0.046) and 7.4 times less symptom improvement (p=0.038) compared to those with older age. Females showed 6.5 times more re-operation rate (p=0.037) and 7.1 times less symptom improvement (p=0.027) than males. No patients experienced complications such as cerebrospinal fluid leakage, postoperative hemorrhage, or infection. Conclusion Endoscopic surgery is feasible for the treatment of DLICs. Female sex and age <12 months are risk factors for re-operation and less symptom improvement.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: Infantile hemangioma (IH) is a common benign vascular tumor that occurs during infancy. Oral propranolol is used as a first-line treatment. However, standardized guidelines for evaluating treatment efficacy, particularly the appropriate timing and parameters for Doppler ultrasound (US), have not been established. This study reports on the evaluation of therapeutic efficacy of oral propranolol solution in IH patients using Doppler US, and aims to propose the appropriate timing and parameters for using Doppler US based on this experience. Methods: A retrospective analysis was conducted on 120 patients with IH who were treated with oral propranolol solution and maintained for over 6 months from May 2017 to April 2023. Doppler US evaluation of IH was performed at diagnosis, 1-2 and 6-12 months after treatment initiation, and 6 months post-therapy cessation. A complete response (CR) was identified as a reduction in vascularity along with a decrease in longest diameter (LD) or thickness of 50% or more. Recurrence was evaluated based on increased vascularity or size 6 months after treatment discontinuation. Results: Of 120 patients with IH, 82 females and 38 males were analyzed. IH was first detected at a median age of 12 days (range, 1-240 days), and treatment began at 76 days (range, 27-570 days), continuing for an average of 10.4 months (range, 5-24 months). Initial Doppler US measurements showed an LD of 2.65±1.52 cm and a thickness of 0.79±0.55 cm, with prominent vascularity. After 1-2 months of treatment, LD and thickness decreased by 12.9% and 25.9%, respectively. By 6-12 months, reductions reached 37.2% and 53.6%. CR occurred in 77 patients (64.2%) after 6-12 months of treatment. Eleven patients (9.2%) experienced a recurrence. Conclusion Doppler US is a valuable modality for evaluating the characteristics, treatment response, and recurrence of IH treated with oral propranolol.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Methods: Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells. Results: FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells. Conclusion This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.