| 1. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epidermal cell migration : V. Transmission electron microscopic study of tympanic membrane and external auditory canal in mouse
- 1996
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Ingår i: Journal for Oto-Rhino-Laryngology. - 0301-1569 .- 1423-0275. ; 58:5, s. 280-7
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Tidskriftsartikel (refereegranskat)abstract
- The morphology of the tympanic membrane (TM) and external auditory canal (EAC) in mice was examined by transmission electron microscopy, in seven different regions: the handle of the malleus (HM) region, the intermediate and annular regions of the pars tensa (PT), the region of the pars flaccida (PF), the annular and osseous regions of the EAC and the cartilaginous region of the EAC. Each region displayed its own unique findings. In most regions of the TM and EAC-except the intermediate region of the PT-basal layer cells formed cytoplasmic processes (CPs) on their basal surface and adhered to the basement membrane (BM) by means of hemidesmosomes (HDs). This observation may suggest the presence of stem cells. In contrast, basal cells in the intermediate region of the PT did not extend any CPs from the basal surface but attached to the BM by a few characteristic spots of HD-like density but lacking the characteristics of HDs. It is concluded that stem cels are not present there and that basal cells connect loosely with the BM, thus providing the necessary morphological conditions to migrate laterally toward the annular region. The outermost layer of the epidermis in the annular region of the EAC showed numerous cytoplasmic projections (so-called 'finger-like projections'), representing keratinization and desquamation of epidermal cells (keratinocytes). These projections are believed to be the terminal differentiation of epidermal cells originating from the general centre in the HM region of the PT. The epidermis of the PF is an extension of the upper wall of the EAC, but the two regions differ morphologically.
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| 2. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epidermal cell migration : VII. Antigen expression of proliferating cell nuclear antigens, PCNA and Ki-67 in human tympanic membrane and external auditory canal
- 1997
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 117:1, s. 100-8
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Tidskriftsartikel (refereegranskat)abstract
- A location of proliferating cells was investigated in eight human normal tympanic membranes (TMs) and external auditory canals (EACs) by an immunohistochemical method using two different types of antibodies for nuclear antigens in proliferating cells: anti-PCNA monoclonal antibody, and anti-Ki-67 polyclonal antibody. Four specimens prepared for cryostat sections were immunostained by both antibodies. Another four were fixed in 4% formaldehyde solution, embedded in paraffin wax and were reacted only with anti-PCNA antibodies. The expression pattern of Ki-67 was basically the same as of PCNA. In the pars tensa (PT), immunoreactivities were expressed in the nuclei of basal layer cells and cells just overlying the basal layer of epidermis both in the handle of the malleus (HM) and annular regions. In the intermediate region of the PT, no immunoreactivity was found basically, apart from a few labelled cells observed in the upper-third of the superior quadrant. In the pars flaccida (PF) and in both the osseous and cartilaginous regions of the EAC, positive cells were also situated in the basal layer and the deeper aspect of the suprabasal layers without any specific distributing pattern. It was certified that the generation centre of epidermal cells (keratinocytes) in the PT was located in both the HM and annular regions, and that stem cells in the PF and the EAC were uniformly scattered in the basal layer and the deeper aspect of the spinous layer. According to these findings, the migratory patterns of auditory epidermal cells in the human TM and EAC were discussed.
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| 3. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epithelial migration : I. Macroscopic evidence of migration and pathways in the rat
- 1996
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 116:3, s. 435-8
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Tidskriftsartikel (refereegranskat)abstract
- Auditory epithelial migration (AEM) was studied in the rat for up to 42 days following the application of dye on the tympanic membrane (TM) and external auditory canal (EAC). Migratory pathways were similar to those in the human. In the pars tensa (PT), pathways were radially and centrifugally oriented from the handle of the malleus (HM) toward the annulus. However, the pathway along the HM from the umbo to the pars flaccida (PF), as reported in the human, was not observed in the rat; instead, a shallow downward pathway along the HM. In the PF, the radial spread of dye-markings from the proximal part of the HM to the upper wall of the EAC, as found in the human, was also observed in the rat. We conclude that the TM and EAC of the rat constitute an appropriate experimental model with which to study the human type of AEM.
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| 4. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epithelial migration : II: Morphological evidence for auditory epidermal cell migration in rat
- 1996
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 116:6, s. 850-3
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Tidskriftsartikel (refereegranskat)abstract
- Morphology of the tympanic membrane (TM) and external auditory canal (EAC) was studied in healthy, intact rat ears. TM-perforated ears (3 days after making the perforation) and TM-perforation-healed ears (14, 28 and 42 days after making the perforation). In intact ears, the epidermis in the annular region of the EAC displayed a characteristic appearance with cytoplasmic protrusions. We termed these protrusions as "finger-like projections". In contrast to the rat, the annular region of the EAC in the guinea-pig did not show "finger-like projections". Following a perforation in the centre of the anterior or the posterior quadrant of the pars tensa in rats the "finger-like projections" disappeared from the annular region on the perforated side of the EAC, while the projections remained on the malleus side of the perforation edge. In perforation-healed ears analysed 42 days after the perforation, the "finger-like projections" had recurred in the annular region on the perforated side of the EAC. The "finger-like projections" are likely to express maturation (keratinization) and desquamation of epidermal cells in the pars tensa and also could constitute morphological evidence of their migration on the TM.
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| 5. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epithelial migration : III. An immunohistologic study using anti-BrdU antibody on tympanic membrane in mouse
- 1997
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Ingår i: Annals of Otology, Rhinology and Laryngology. - 0003-4894 .- 1943-572X. ; 106:5, s. 414-21
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Tidskriftsartikel (refereegranskat)abstract
- A localization pattern of epidermal cells on the tympanic membrane (TM) and their migratory patterns were studied in mice, by means of immunohistologic technique using an anti-bromodeoxyuridine (BrdU) antibody. The BrdU was instilled intraperitoneally and the animals were painlessly sacrificed between 1 hour and 10 days after the injection. An immunostaining technique using anti-BrdU antibodies was applied on whole mount TM tissues. One hour after injection, BrdU-labeled cells were found in the handle of the malleus (HM) region and in the annular region of the pars tensa of the TM. Some labeled cells were observed in the intermediate region of the upper half of the superior quadrant, but no labeled cells were found in the remaining part of the intermediate region. Labeled cells were also evident in the pars flaccida without any particular pattern of distribution. As time elapsed after the injection, the labeled cells first appearing in the HM region had migrated laterally and inferiorly from the HM toward the annulus, while those in the annular region had considerably decreased in number. Results of the present study are the following: 1) the proliferation center of epidermal cells in the pars tensa is located in two different areas, i.e., the HM region and annular region, 2) newly generated cells in the HM region migrated from the HM region toward the annular region, whereas those in the annular region migrate from the the annular region to the external auditory canal, and 3) no specific generation center is located in the pars flaccida. On the basis of these results, we discuss the relationship between the site of the proliferation center of epidermal cells and their migratory patterns.
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| 6. |
- Kakoi, Hiroyuki, et al.
(författare)
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Auditory epithelial migration : IV. Light and scanning electron microscopic studies of the tympanic membrane and external auditory canal in the mouse
- 1996
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Ingår i: Journal for Oto-Rhino-Laryngology. - 0301-1569 .- 1423-0275. ; 58:3, s. 136-42
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Tidskriftsartikel (refereegranskat)abstract
- The fine structures of the tympanic membrane and external auditory canal (EAC) were observed in the mouse under both the light microscope and scanning electron microscope. According to the differences in morphological features of the epidermis and epidermal cells, they were grossly classified into 8 types of region: (1) the region of the handle of the malleus, (2) the intermediate region of the pars tensa (PT), (3) the annular region of the PT, (4) the region of the pars flaccida, (5) the annular region of the anterior, inferior and posterior walls of the EAC, (6) the osseous region of the anterior, inferior and posterior walls of the EAC, (7) the region of the upper wall of the EAC and (8) the cartilaginous region of the anterior, inferior and posterior walls of the EAC. The specific structure "finger-like projections' was visualized throughout in the annular region of the EAC. The morphology of the region of the upper wall of the EAC was almost identical with that of the cartilaginous region of the anterior, inferior and posterior walls of the EAC.
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| 7. |
- Kakoi, Hiroyuki, et al.
(författare)
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Cytokeratin expression patterns by one- and two-dimensional electrophoresis in pars flaccida cholesteatoma and pars tensa cholesteatoma
- 1995
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 115:6, s. 804-10
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Tidskriftsartikel (refereegranskat)abstract
- Expression patterns of cytokeratins (CKs) in normal skin, in pars flaccida type cholesteatoma (PFTC), and in pars tensa type cholesteatoma (PTTC) were examined by means of one- and two-dimensional electrophoretic techniques. Both CKs 14 and 5 pair (CKs 14/5) and CKs 10/1 were found in all materials. Neither CKs 16/6 nor 19 was found in the skin. CKs 16/6 and 19 were both found in 3 out of 5 PFTCs, only CKs 16/6 in 1 out of 5 and neither CKs 16/6 nor 19 in 1 out of 5. CKs 16/6 and 19 were both found in 1 out of 3 PTTCs, only CKs 16/6 in 1 out of 3 and neither CKs 16/6 nor 19 in 1 out of 3. There was no significant difference in the CKs expression patterns between PFTC and PTTC. The expression of CKs 16/6 and 19 suggested that their matrix epithelia were hyperproliferative. However, not all of the cholesteatomas were always hyperproliferative. Patterns of the terminal differentiation of CKs 1, 5, 10 and 14 in the PFTC or the PTTC were basically the same as those in the skin. In the cholesteatoma, eack CK gradually diminished in molecular weight in the cornified layer and debris. Desmosomal proteins were abundant in skin but not in cholesteatomas.
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| 8. |
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| 9. |
- Kakoi, Hiroyuki, et al.
(författare)
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Morphological changes in rat submandibular gland mucous cells during fixation with 10% formalin
- 1996
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Ingår i: European Archives of Oto-Rhino-Laryngology. - 0937-4477 .- 1434-4726. ; 253:4-5, s. 214-21
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Tidskriftsartikel (refereegranskat)abstract
- The features of mucous cells in 10% formalin (FA)-fixed submandibular glands differ markedly from those fixed in glutaraldehyde (GA). We therefore studied morphological changes in mucous cells during 10% FA fixation. Mucous cells were fixed in either 10% FA, neutral sodium-phosphate-buffered (Na-PBed) 10% FA, ice-cold 10% FA or an ice-cold fixative mixture of 2.0% paraformaldehyde (PA) and 0.5% GA. Two different methods were used: immersion fixation and venous perfusion fixation. The 10% FA-fixed tissues had elliptical or flattened nuclei, a clear cytoplasm and no secretory granules. Tissues fixed with the fixative mixture displayed almost round nuclei, a broad endoplasmic reticulum and abundant secretory granules in the cytoplasm. Tissues immersion-fixed with neutral Na-PBed 10% FA or perfusion-fixed with ice-cold 10% FA had almost the same light microscopic appearance as that of the mixture-fixed tissues. To elucidate the process of morphological changes during 10% FA fixation at room temperature, samples immersed in 10% FA for varying periods of time were postfixed immediately in the fixative mixture and exposed to microwave irradiation. This method produced a variety of findings, even within the same section. There was a significant difference in the findings seen in the center of the section and at the periphery. The initial changes caused by 10% FA were rupture of the secretory granules located in the perinuclear region and destruction of the perinuclear organelles such as Golgi apparatus, mitochondria and endoplasmic reticulum. Absorption of the endoplasmic reticulum progressed so that the perinuclear region became translucent. To obtain a better structure in mucous cells from the fixed submandibular gland tissues, an appropriate fixative such as GA should be used and the fixative should infiltrate into the tissues as quickly as possible.
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