Publications by authors named "Hideaki Okuyama"

Tracheal reconstruction is necessary in patients with large tracheal defects. Previously, artificial tracheae made of polypropylene and collagen sponge have been used clinically by our group. As a basic research aimed at promoting epithelialization for infection defense, we transplanted cell sheets of human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (iAECs) with artificial tracheae into tracheal defects of rats and confirmed their engraftment.

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Human vocal folds (VFs), a pair of small, soft tissues in the larynx, have a layered mucosal structure with unique mechanical strength to support high-level tissue deformation by phonation. Severe pathological changes to VF have causes including surgery, trauma, age-related atrophy, and radiation, and lead to partial or complete communication loss and difficulty in breathing and swallowing. VF glottal insufficiency requires injectable VF biomaterials such as hyaluronan, calcium hydroxyapatite, and autologous fat to augment VF functions.

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No radical treatment is available for the regeneration of dysfunction and defects in airway epithelia. Artificial tracheae made of polypropylene and collagen sponge were used in clinical studies to reconstitute tracheae after resection. For early epithelialization of the luminal surface of the artificial trachea, a model was established, that is, an artificial trachea covered with human-induced pluripotent stem cell-derived airway epithelial cells (hiPSC-AECs) was transplanted into a tracheal defect in an immunodeficient rat.

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The airway epithelia (AE) play a role in the clearance of foreign substances through ciliary motility and mucus secreted. We developed an artificial trachea that is made of collagen sponges and polypropylene mesh for the regeneration of the tracheal defect, and it was used for a clinical study. Then, a model in which the luminal surface of an artificial trachea was covered with a human-induced pluripotent stem cell-derived AE (hiPSC-AE) was transplanted into the tracheal defect of nude rats to promote epithelialization.

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Article Synopsis
  • Previous studies confirmed that transplanting human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) can help regenerate cartilage in X-SCID rats, prompting further research on their effectiveness in nude rats.
  • In the study, iMSCs were created from hiPSCs and then implanted into thyroid cartilage defects in nude rats, with analyses conducted 4 or 8 weeks later to assess cell survival and cartilage regeneration.
  • The findings showed that 91.7% of the rats had surviving transplanted iMSCs, and signs of cartilage-like regeneration were evident, indicating that nude rats could be a viable alternative model for future cartilage regeneration studies with fewer complications from infection.
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The 5-year overall survival rate remains approximately 50% for head and neck (H&N) cancer patients, even though new cancer drugs have been approved for clinical use since 2016. Cancer drug studies are now moving toward the use of three-dimensional culture models for better emulating the unique tumor microenvironment (TME) and better predicting response to cancer treatments. Distinctive TME features, such as tumor geometry, heterogenous cellularity, and hypoxic cues, notably affect tissue aggressiveness and drug resistance.

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Congenital nasal pyriform aperture stenosis (CNPAS) is a rare cause of respiratory distress in newborns. This paper reports a case of severe CNPAS that required endotracheal intubation immediately after birth, and eventually, surgical intervention. At birth, the width of the pyriform aperture was only 4 mm, and the patient was completely unable to breathe through his nose.

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Introduction: Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats.

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The nasal mucosa functions as a frontline biological defense against various foreign substances and pathogens. Maintaining homeostasis of the nasal epithelium is necessary to promote good health. Nasal epithelia are constantly replaced under normal conditions.

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The laryngotracheal cartilage is a cardinal framework for the maintenance of the airway for breathing, which occasionally requires reconstruction. Because hyaline cartilage has a poor intrinsic regenerative ability, various regenerative approaches have been attempted to regenerate laryngotracheal cartilage. The use of autologous mesenchymal stem cells (MSCs) for cartilage regeneration has been widely investigated.

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Tracheal resection is often performed for malignant tumours, congenital anomalies, inflammatory lesions, and traumatic injuries. There is no consensus on the best approach for the restoration of tracheal functionality in patients with tracheal defects. Artificial grafts made of polypropylene and collagen sponge have been clinically used by our group.

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Objectives: To evaluate the outcome and to confirm the validity of cochlear implantation for syndromic deafness in patients with mitochondrial disease.

Study Design: Retrospective case review.

Setting: Tertiary referral center.

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There are two techniques for excising a parotid gland tumor. The first technique is the anterograde approach, and the second is the retrograde approach. Although the anterograde approach has generally been adopted, the retrograde approach may be useful depending on the identification and dissection of the facial nerve and the localization of the tumor.

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