Publications by authors named "Seyama K"

Article Synopsis
  • Tuberous sclerosis complex (TSC) is a genetic disorder difficult to diagnose due to non-specific symptoms, leading to a study investigating the time to diagnosis (TTD) among Japanese patients.
  • The research analyzed data from 2005 to 2020, dividing patients into two cohorts based on age at diagnosis, and assessed the TTD and incidence of TSC-related and unrelated symptoms.
  • Findings showed that those with renal tumors experienced significant delays in diagnosis and that patients attending TSC clinics had quicker diagnoses, with epilepsy being the most common symptom in older patients and cardiac rhabdomyoma in younger patients.
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α-antitrypsin deficiency (AATD) is a hereditary disorder with a global prevalence that differs across regions. AATD is highly prevalent in Europe and North America but rarely found in Asian countries, including Japan, possibly because of the founder effect of the pathogenic SERPINA1 variants PI*Z and PI*S. However, AATD remains underdiagnosed even in high-prevalence and low-prevalence regions, possibly because of lack of awareness.

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A 53-year-old man with chronic dyspnea and bilateral pleural effusion was subsequently diagnosed with idiopathic chylothorax. Lymphatic scintigraphy confirmed lymphatic fluid leakage at the left venous angle, prompting management with lymphaticovenular anastomosis (LVA). Although the left pleural effusion was controlled, the right pleural effusion continued to increase, resulting in bilateral leg lymphedema that was refractory to LVA.

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Lymphangioleiomyomatosis (LAM) is a rare disease involving the proliferation of LAM cells in the lungs and the axial lymphatic system and mechanistic target of rapamycin (mTOR) inhibitors are the only effective medicines for treating it. Patients suffering from LAM, who are allergic to mTOR inhibitors can be treated by desensitizing them to the medicine. A 39-year-old woman presented with dyspnea caused by chylous pleural effusion, ascites, and retroperitoneal lymphangioleiomyomas.

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Background And Objective: Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease associated with the functional tumour suppressor genes TSC1 and TSC2 and causes structural destruction in the lungs, which could potentially increase the risk of lung cancer. However, this relationship remains unclear because of the rarity of the disease.

Methods: We investigated the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan, using data from the Japanese Cancer Registry as the reference population.

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Erdheim-Chester disease (ECD) is a rare inflammatory myeloid neoplasm affecting multiple systems and organs. The patient is a 38-year-old male with ECD complicated with pulmonary and cutaneous manifestations but without bone lesions diagnosed in 2008. Initial treatment with oral and inhaled corticosteroids achieved persistent favorable disease remission.

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The characteristics of the pulmonary cysts on the high-resolution computed tomography (HRCT) chest images are an important diagnostic clue to distinguish among cystic lung diseases. The diagnostic accuracy of HRCT was reported to be as high as 90% by experienced pulmonologists and radiologists. Herein, we report the case of an elderly woman with Birt-Hogg-Dubé syndrome (BHDS) whose HRCT images displayed lymphangioleiomyomatosis-like features of the pulmonary cysts, rendering it difficult for us to diagnose BHDS.

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Extrapleural air is a rare condition that may concurrently develop with pneumomediastinum and pneumothorax, especially in older patients with fragile connective tissues. Physicians should consider extrapleural air to prevent inadvertent harm. Coronal reconstruction computed tomography images help appreciate extrapleural air and recognize the track of extrapulmonary air.

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Objectives: Thoracic endometriosis-related pneumothorax (TERP) frequently recurs even after surgery. Meanwhile, postoperative hormonal therapies (HTx) are believed to be effective for pelvic endometriosis. Therefore, we evaluated the relationship between postoperative TERP recurrence and postoperative HTx in a retrospective observational study.

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Lymphangioleiomyomatosis (LAM) is a tuberous sclerosis complex (TSC)-associated tumor, characterized by the expression of neural crest lineages including neuronal markers. Neural crest cells can differentiate into multiple cell types that contribute to tissues associated with TSC-related tumors, and TSC-related tumors could be specifically associated with distinct neural crest subtypes. This study aimed to clarify the clinicopathological effects of expression of neuronal markers in LAM.

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Background: The clinical pulmonary manifestations and genetic features of Birt-Hogg-Dubé syndrome (BHDS) in Asian patients remained unclear. We aimed to clarify the clinical features of BHDS-associated pneumothorax (PTX) and retrospectively investigate potential contributing factors in the largest Asian cohort to date.

Methods: We reviewed the clinical and genetic data collected in 2006-2017, from the BHDS patients who were Asian and presented with pulmonary cysts with or without a history of PTX.

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Objective: Pregnant patients with lymphangioleiomyomatosis (LAM) and renal angiomyolipomas (AMLs) require care for both renal AMLs and pulmonary dysfunction because AMLs can grow and rupture during pregnancy, potentially causing hemorrhagic shock and fetal death. This study examined whether prophylactic transcatheter arterial embolization (TAE) could prevent the pregnancy-associated growth and rupture of renal AMLs in patients with LAM.

Methods: This retrospective study included five women with 14 renal AMLs (initial diameter, ≥2 cm) first encountered between September 2010 and August 2015 who subsequently became pregnant.

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Background: Electronic cigarettes (e-cigarettes) are used worldwide as a substitute for conventional cigarettes. Although they are primarily intended to support smoking cessation, e-cigarettes have been identified as a gateway to smoking habits for young people. Multiple recent reports have described the health effects of inhaling e-cigarettes.

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Background: Safety and pharmacokinetics (PK) of alpha-proteinase inhibitor, modified process (Alpha-1 MP), was evaluated in a clinical trial of Japanese patients with alpha-antitrypsin deficiency (AATD). The present study aimed to evaluate the long-term safety of weekly intravenous infusions of 60 mg/kg Alpha-1 MP in Japanese patients with AATD.

Methods: This was a multi-center, open-label extension (OLE) study that enrolled adult patients with AATD, who had completed the preceding safety and PK clinical trial.

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Background: General surgery for patients with lymphangioleiomyomatosis (LAM) is infrequent, however, general surgeons also occasionally experience it. Only a few reports have described the specific perioperative management appropriate for patients with LAM. Hence, in this case series, we aimed to investigate the surgical outcomes of LAM patients and their characteristics.

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In 2020, we reported a low seroprevalence of N-specific antibodies in 4147 health care workers (HCWs) at a frontline hospital in Tokyo, Japan. In Japan, a vaccine campaign was launched in early 2021. We re-evaluated seroprevalences of N- and S-specific antibodies in 2202 HCWs who took two doses of the BNT162b2 vaccine.

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The Delta variant has dominated SARS-CoV-2 infections in Tokyo, Japan from June 2021 to date. We conducted a retrospective cohort study to assess BNT162b2 vaccine effectiveness during the surge in Delta among 3,911 healthcare workers (HCWs) at a medical center of Tokyo with a high vaccination rate of 84.1%.

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Article Synopsis
  • Pulmonary emphysema is primarily caused by long-term exposure to cigarette smoke, but newer alternatives like heated tobacco products (HTPs), specifically IQOS, are marketed as safer.
  • A study using 12-week-old male mice showed that exposure to IQOS aerosol for six months resulted in weight loss and increased levels of harmful substances in the body, similar to those seen with traditional cigarette smoke.
  • The findings indicate that chronic use of IQOS can lead to pulmonary emphysema through pathways related to cell death, suggesting that these heated tobacco products are not entirely harmless.
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Lymphangioleiomyomatosis (LAM) is a rare pulmonary neoplasm, clinically associated with dyspnea and respiratory failure. Current therapeutic modalities do not necessarily reach satisfactory outcome and novel therapeutic approaches are currently warranted. Therefore, in this study, we focused on vasohibin-1 (VASH1) and -2 (VASH2); VASH1 terminated and VASH2 promoted angiogenesis.

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Article Synopsis
  • Three-port video-assisted thoracoscopic surgery (VATS) is the standard treatment for primary spontaneous pneumothorax (PSP), but it has a relatively high postoperative recurrence rate.
  • Bullectomy helps reduce recurrences, but additional techniques like pleural covering and chemical pleurodesis are often needed.
  • Newer minimally invasive methods, such as uniportal VATS and needlescopic surgery, offer benefits like less pain and better cosmetic outcomes, and are expected to gain popularity for treating PSP.
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Aim: Depression is a frequent outcome of long-term stress, but no studies have examined depression rates among Japanese healthcare workers fighting the COVID-19 pandemic. Therefore, we conducted a web-based interview of hospital employees to assess depression prevalence and factors.

Methods: This observational cohort study was conducted from July to August, 2020, as part of a mandatory health checkup of Juntendo University Hospital employees (Tokyo, Japan).

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Evidence of BNT126b2 vaccine effectiveness and breakthrough has been primarily demonstrated in populations outside of Asia; studies in the Western Pacific region are limited. Our retrospective cohort study assessed SARS-CoV-2 cases after vaccine rollout starting from mid-March 2021 at a tertiary hospital in Tokyo. Of 8,749 staff members, no fully vaccinated staff demonstrated confirmed infection, versus 19 cases in unvaccinated or partially vaccinated staff, by the end of June.

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As the first authorized COVID-19 vaccine in Japan, the BNT162b2 mRNA COVID-19 vaccine is utilized for mass vaccination. Although efficacy has been proved, real-world evidence on reactogenicity in Japanese personnel is needed to prepare the public. Healthcare workers in a large academic hospital in Japan received two doses of the Pfizer-BioNTech vaccine from March 17 to May 19, 2021.

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Birt-Hogg-Dubé syndrome (BHDS), an autosomal dominant inheritance disease caused by folliculin (FLCN) mutations, is associated with lung cysts and spontaneous pneumothorax. The possibility of FLCN haploinsufficiency in pleural mesothelial cells (PMCs) contributing to development of pneumothorax has not yet been clarified. Electron microscopy revealed exposed intercellular boundaries between PMCs on visceral pleura and decreased electron density around the adherens junctions in BHDS.

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