[A case of hereditary angioedema defined by gene analysis].

Hereditary angioedema (HAE) is a disease that is characterized by localized edema that can occur anywhere in the body, and is caused by a mutation of the C1-inhibitor gene. In the oto-rhino-laryngological region, it occurs in the mouth, pharynx, larynx, and on the face. Occasionally, laryngopharyngeal edema can in particular sometimes be fatal. We report herein on a case of a 59-year-old female who was admitted to our hospital for further evaluation and treatment of laryngopharyngeal edema. She had a history of subcutaneous edema during pregnancy and ascites of unknown origin without a definitive diagnosis. On admission, there were low C1 inhibitor and complement C4 levels, and normal C1q levels. As the patient had no family history of HAE, we performed gene analysis, which revealed mutation of the C 1-inhibitor gene in Exon7. In cases of HAE without family history, gene analysis is required for accurate diagnosis.

A tissue-engineered trachea derived from a framed collagen scaffold, gingival fibroblasts and adipose-derived stem cells.

In some types of tracheal disease, tracheal resection is required. For patients with tracheal resection, artificial grafts, made from collagen sponge with a spiral polypropylene stent and mesh, have been clinically used by our group. However, epithelial regeneration was confirmed to be slow. In the present study, we investigated the potential of gingival fibroblasts (GFBs) and adipose-derived stem cells (ASCs) as autologous transplanted cells in combination with artificial graft for tracheal epithelial regeneration. In in vitro co-culturing with tracheal epithelial cells, GFBs stimulated epithelial cell differentiation and reconstruction of a pseudostratified epithelium. ASCs stimulated epithelial cell proliferation and reconstruction of a multi-layered epithelium. Subsequently, we prepared three kinds of bioengineered scaffolds from GFBs and/or ASCs and implanted them into rat tracheal defects. The bioengineered scaffolds containing GFBs were covered with tracheal epithelial cells after 1 week, and highly ciliated epithelium was formed after 2 weeks of transplantation. The bioengineered scaffold containing ASCs induced thick epithelium, and then pseudostratified epithelium containing goblet cells was formed. Furthermore, the application of both GFBs and ASCs had synergistic effects on tracheal epithelial regeneration, suggesting that bioengineered scaffolds containing GFBs and ASCs are useful for hastening tracheal epithelial regeneration.

Cochlear implantation in a case of bilateral sensorineural hearing loss due to mumps.

It is well known that unilateral profound sensorineural hearing loss is caused by mumps; however, bilateral deafness is rare. Herein we report a case of bilateral profound hearing loss caused by mumps infection in a four-year-old boy. Labyrinthitis due to the mumps virus was suspected. His verbal understanding was poor, and he completely stopped talking. He was soon fitted with a hearing aid, but it proved insufficient. Thereupon, cochlear implantation was performed on his left ear. Six months after the operation, his speech perception and speech production were improved. In cases of bilateral profound hearing loss due to mumps infection conservative therapy is ineffective; therefore, cochlear implantation is recommended. Vaccine coverage for mumps virus is also strongly recommended in Japan.

Clinical application of in situ tissue engineering using a scaffolding technique for reconstruction of the larynx and trachea.

OBJECTIVES: The objective of the present study was to demonstrate the efficacy of the clinical application of in situ tissue engineering using a scaffolding technique for laryngeal and tracheal tissue. METHODS: We have developed a tissue scaffold made from a Marlex mesh tube covered by collagen sponge. Based on successful animal experimental studies, in situ tissue engineering with a scaffold implant was applied to repair the larynx and trachea in 4 patients. RESULTS: In 1 patient with subglottic stenosis, the thyroid cartilage, cricoid cartilage, and cervical trachea with scarring and granulation were resected and reconstructed by use of the scaffold. In 3 patients with thyroid cancer, the trachea and cricoid cartilage with tumor invasion were resected and the scaffold was implanted into the defect. Postoperative endoscopy during the observation period of 8 to 34 months showed a well-epithelialized airway lumen without any obstruction. CONCLUSIONS: Our current technique of in situ tissue engineering using a scaffold shows great potential for use in the regeneration of airway defects.

Regeneration of the trachea using a bioengineered scaffold with adipose-derived stem cells.

OBJECTIVES: Our group has developed and clinically applied an artificial graft made from a collagen sponge scaffold for the regeneration of tracheal tissue. However, the artificial graft requires about 2 months for epithelial regeneration. The purpose of the present study was to accelerate the regeneration process of the trachea through the effective use of a bioengineered scaffold. Adipose-derived stem cells (ASCs) with multilineage differentiation capability were used. In our study, we implanted a bioengineered scaffold that included autologous ASCs into tracheal defects in rats. METHODS: Collagen gel, including ASCs labeled with monomeric yellow fluorescent protein, was layered onto the surface of the collagen sponge to form a bioengineered scaffold. This scaffold was implanted into the tracheal defects in rats. A control scaffold without ASCs was also implanted. RESULTS: On day 14 after implantation, a pseudostratified columnar epithelium with well-differentiated ciliated and goblet cells and neovascularization was observed in rats that received the implant with the bioengineered scaffold that included ASCs. CONCLUSIONS: These results suggested that implanted ASCs accelerated neovascularization and epithelialization on the regenerated trachea. Thus, our newly developed bioengineered scaffold contributes to tracheal regeneration.

Regeneration of tracheal epithelium utilizing a novel bipotential collagen scaffold.

OBJECTIVES: The purpose of the present study was to evaluate the effectiveness of a novel bipotential collagen scaffold as a bioengineered trachea for the regeneration of the tracheal epithelium. METHODS: The bipotential collagen scaffold was developed by conjugating a collagen vitrigel membrane to a collagen sponge in order to promote both epithelial cell growth and mesenchymal cell infiltration. The bipotential collagen scaffold was transplanted into tracheal defects in rats, and a conventional collagen sponge was implanted as a control model. Histologic examinations were undertaken to evaluate the results. RESULTS: The bioengineered trachea was covered with epithelium in the vitrigel model, but not in the control model, at 7 days after implantation. At 14 days after implantation, the bioengineered trachea was covered with epithelium involving the basal cell layer in the vitrigel model. At 28 days after implantation, a columnar ciliated epithelium was observed only in the vitrigel model. CONCLUSIONS: Our technique for trachea reconstruction using a novel bipotential collagen scaffold affords a feasible approach for accelerating epithelial regeneration on the intraluminal surface of the host tracheal defect.

Potential of heterotopic fibroblasts as autologous transplanted cells for tracheal epithelial regeneration.

The tracheal epithelium maintains the health of the respiratory tract through mucociliary clearance and regulation of ion and water balance. When the trachea is surgically removed, artificial grafts have been clinically used by our group to regenerate the trachea. In such cases, the tracheal epithelium needs 2 months for functional regeneration. Previous study has shown that fibroblasts facilitate tracheal epithelial regeneration. In this study, heterotopic fibroblasts originating from the dermis, nasal, and gingival mucosa were cocultured with tracheal epithelial cells to evaluate their potential as autologous transplanted cells for tracheal epithelial regeneration. The epithelia induced by the heterotopic fibroblasts showed differences in structure, cilia development, mucin secretion, and expression of ion and water channels. These results indicated that nasal fibroblasts could not induce mature tracheal epithelium and that dermal fibroblasts induced epidermis-like epithelium. Only the gingival fibroblasts (GFBs) could induce morphologically and functionally normalized tracheal epithelium comparable to the epithelium induced by tracheal fibroblasts. Epithelial cell proliferation and migration were also upregulated by GFBs. These results indicate that GFBs are useful as autologous transplant cells for tracheal epithelial regeneration.

Effect of fibroblasts on tracheal epithelial regeneration in vitro.

Several artificial grafts for covering deficient trachea have been produced through tissue engineering. Recently, our group clinically used an artificial trachea made from collagen sponge for patients with noncircumferential tracheal resection. However, the slowness of epithelial regeneration on the surface of the artificial trachea was confirmed as one particular problem. In this study, we co-cultured tracheal epithelial cells with fibroblasts and examined effects of fibroblasts on epithelial regeneration in vitro. Fibroblasts activated epithelial cell proliferation and migration. In co-culture with fibroblasts, epithelial cells reconstructed pseudostratified epithelium, which was composed of ciliated, goblet, and basal cells. Furthermore, a basement membrane was reconstructed between epithelial cells and fibroblasts, and integrin beta4 was also observed there. Fibroblasts rapidly increased mucin secretion by epithelial cells. These results indicate that stimulatory effects of fibroblasts on epithelial cell migration, proliferation, and differentiation would reduce the time required for covering of epithelial cells on the defect of luminal surface and hasten regeneration of morphologically and functionally normalized epithelium involving the reconstruction of basement membrane.

Age-dependent degeneration of the stria vascularis in human cochleae.

OBJECTIVE: Aging is a common cause of acquired hearing impairments. This study investigated age-related morphologic changes in human cochleae, with a particular focus on degeneration of the stria vascularis (SV) and the spiral ganglion (SG). STUDY DESIGN: Retrospective case review. METHODS: The study group comprised 91 temporal bones from individuals aged 10 to 85 years who had no history or audiometric findings suggestive of specific causes of cochlear degeneration. We quantified the SV and SG atrophy at each cochlear turn using morphometric measurements. Correlations of the SV and SG atrophy with age, audiometric patterns of hearing loss, and auditory thresholds were statistically investigated. RESULT: The SV and the SG both showed a tendency for progressive atrophy to develop with age. However, statistically significant correlations were observed between aging and SV atrophy only in the apical and basal cochlear turns. These findings were consistent with those reported previously in gerbils. No significant correlations were detected between SV or SG atrophy and audiometric findings. CONCLUSION: SV atrophy appears to be the most prominent anatomic characteristic of aged human cochleae.

Tissue engineering for regeneration of the tracheal epithelium.

OBJECTIVES: The slowness of epithelialization on the artificial trachea that has been successfully used in humans is a problem. The purpose of this study was to develop a way to regenerate the epithelium on the surface of this artificial trachea. METHODS: In an in vitro study, isolated rat tracheal epithelial cells were seeded on a collagenous gel that was stratified on a collagenous sponge. Histologic and immunohistochemical examinations were made. In an in vivo study, we transplanted grafts with green fluorescent protein-positive tracheal epithelial cells onto the tracheal defects of normal rats. At 3, 7, 14, and 30 days after the operation, histologic and immunohistochemical examinations were made. RESULTS: In the in vitro study, the 3 layers--the epithelium, gel, and sponge--could be observed. The epithelium expressed cytokeratin 14, cytokeratin 18, and occludin. In the in vivo study, the artificial trachea was covered with epithelium at 3 days after operation, and then the epithelium differentiated from single- or double-stratified squamous epithelium into columnar ciliated epithelium. Green fluorescent protein-positive cells were found 3 days after operation. CONCLUSIONS: We believe that the method used in our experiment is an effective way to regenerate the epithelium on the surface of an artificial trachea. With further experimentation, this method should be suitable for clinical application.