Biomedical subjects

Yasushi Takeda

Publications and source records attributed to Yasushi Takeda.

5 recordsLinked to original sources

PubMed2006

Expression of Notch1 and Hes5 in the developing olfactory epithelium.

CONCLUSION: Notch signaling pathway may play an important role in the development of the olfactory epithelium (OE). Objectives. To elucidate whether the Notch signaling pathway mediates the developmental processes in the developing OE. MATERIALS AND METHODS: The expression of Notch1 and Hes5 in the developing OE of mice with ages ranging from embryonic day (E) 11 to postnatal day (PN) 14 was examined. RESULTS: As detected by in situ hybridization, Notch1 was expressed in scattered cells located in the basal portion of the embryonic OE and later in the cell layer adjacent to the basal lamina from E11 to PN14. Hes5 was expressed in scattered cells located in the basal portion of the embryonic OE from E11. However, at the late embryonic stage, the number of Hes5-positive cells decreased and after birth distinct Hes5-positive cells were not observed in the OE.

Animals↗

PubMed2005

The engraftment of transplanted bone marrow-derived cells into the olfactory epithelium.

To investigate whether bone marrow cells migrate and are engrafted into the olfactory epithelium and differentiate into olfactory neurons, bone marrow cells of green fluorescence protein (GFP) mice were transplanted into lethally irradiated recipient mice. Immunohistochemical staining was performed to evaluate the engraftment of donor bone marrow cells into the olfactory epithelium. Immunostaining for GFP was found initially in the olfactory epithelium 2 weeks after bone marrow reconstruction. The percentage of GFP positive cells increased up to 12 months after bone marrow reconstruction. Double staining for GFP and olfactory marker protein showed that a population of the GFP-positive cells had characteristics of olfactory neurons. These results demonstrate that bone marrow cells can be engrafted in the olfactory epithelium and then differentiate into olfactory neuron cells.

Analysis of Variance↗

PubMed2005

Regeneration of rat auditory ossicles using recombinant human BMP-2/collagen composites.

Tympanoplasty operations to improve hearing impairment require a wide middle ear cavity and reconstruction of columellar formations. There is no specific material for use in the reconstruction of columellar formations. Tissue response to BMP has been employed as regenerative material. To our knowledge, however, there are no reports of the reconstruction of columellar formations using recombinant human bone morphogenetic protein-2/bovine collagen composites in the middle ear. The purpose of this study is to investigate whether recombinant human bone morphogenetic protein-2/bovine collagen composites (rhBMP-2 composites) are appropriate for use as regenerative material for tympanoplasty. In the form of pellets, rhBMP-2 composites were implanted as columellae into the tympanic cavity. At 2, 4, 6, 8, and 12 weeks after surgery, the middle ear of the animals (n = 4 at each week) was stained with hematoxylin-eosin for light microscopic observation. All composites were in the process of ossification or had ossified according to their developmental stages and were covered with a single layer of squamous or cuboidal epithelium. The new bone formed in these composites was persistently stable and displayed some columellar conditions assessed by histological examination. This study led to the conclusion that rhBMP-2 composites make excellent regenerative material for auditory ossicles.

Animals↗

PubMed2003

Migration of intracranial hemostatic clip into the lumbar spinal canal causing sacral radiculopathy: a case report.

STUDY DESIGN: A case report. OBJECTIVES: A case of spontaneous migration of intracranial hemostatic clip into the lumbar spinal canal causing a sacral radiculopathy and severe low back pain was presented. SUMMARY OF BACKGROUND DATA: Only five cases have been reported in the literature. The first report was described by Oyesiku in 1986; thereafter, four cases have been reported. This serves as the first report clearly describing the relationship between the migrated site of a foreign body and neurologic symptom, as well as achieving a remission of symptom after surgical extirpation. METHODS: A patient who had received hemostatic clips to the aqueductal stenosis 31 years ago presented with low back pain and sacral radiculopathy. Plain radiography, myelography, and subsequent CT revealed that a metal foreign body was located in the subarachnoid space at L4 level. Laminectomy of L4 and extirpation of the foreign body were performed. RESULTS: The foreign body was a hemostatic clip made of cobalt-based alloy that had been applied during the previous intracranial surgery. The clip irritated the adjoined intrathecal nerve root and possibly caused the adhesive arachnoiditis. All symptoms completely disappeared after the extirpation. CONCLUSIONS: An uncommon case of an intracranial hemostatic clip migrating into the lumbar subarachnoid space as well as causing sacral radiculopathy was reported. The surgical extirpation provided an excellent clinical outcome.

Foreign-Body Migration↗

PubMedDate not supplied

Mastoid obliteration by BMP-2/collagen composites: an experimental study using tissue engineering.

PURPOSE: Several materials have been used in the application of mastoid cavity obliteration during surgery for cholesteatoma; however, nothing has won universal acceptance. Through the advancement of tissue engineering, bone morphogenetic protein-2 (BMP-2)/collagen composites have been elucidated as inducers of heterogenic bone formation. This study was performed to investigate whether these composites are potentially obliteration materials for use in the mastoid cavity by using an animal experimental study. MATERIALS AND METHODS: The composites were implanted in the rat mastoid to investigate whether new bone would be tissue engineered in the mastoid and, if so, whether the newly formed bone was stable. The composites were examined histologically over a 24-week period. RESULTS: The composites implanted in the rat mastoid were able to tissue engineer new bone, and the newly formed bone was stable as assessed histologically, with almost normal bone structure, that was not resorbed during the 24-week period. Adverse immunological reactions were not found during our observation. CONCLUSIONS: Bone that was tissue engineered by the BMP-2/collagen composites was stable as assessed by histological examination and persisted in the rat mastoid. The present study shows that the composites have the potential to become real materials for use in mastoid obliteration.

Animals↗