Adult dental epithelial stem cell-derived organoids deposit hydroxylapatite biomineral / 国际口腔科学杂志·英文版

Ameloblasts are specialized cells derived from the dental epithelium that produce enamel, a hierarchically structured tissue comprised of highly elongated hydroxylapatite (OHAp) crystallites. The unique function of the epithelial cells synthesizing crystallites and assembling them in a mechanically robust structure is not fully elucidated yet, partly due to limitations with in vitro experimental models. Herein, we demonstrate the ability to generate mineralizing dental epithelial organoids (DEOs) from adult dental epithelial stem cells (aDESCs) isolated from mouse incisor tissues. DEOs expressed ameloblast markers, could be maintained for more than five months (11 passages) in vitro in media containing modulators of Wnt, Egf, Bmp, Fgf and Notch signaling pathways, and were amenable to cryostorage. When transplanted underneath murine kidney capsules, organoids produced OHAp crystallites similar in composition, size, and shape to mineralized dental tissues, including some enamel-like elongated crystals. DEOs are thus a powerful in vitro model to study mineralization process by dental epithelium, which can pave the way to understanding amelogenesis and developing regenerative therapy of enamel.

Tuberculosis of the Nasal Cavity and Paranasal Sinuses / 대한이비인후과학회지

After a remarkable decline for several decades, the incidence of tuberculosis as a whole and, in particular, the extrapulmonary type, is on the rise in the world. The resurgence of the tuberculosis was attributed to the emergence of multidrug-resistant organisms and increase of immunodepressed hosts. Although tuberculosis of the nasal cavity and paranasal sinuses is rare, it is important to include it in the differential diagnosis for chronic nasal symptoms. The authors have experienced six cases of sinonasal tuberculosis. We reviewed these cases as representing the characteristics of sinonasal tuberculosis occurring in Korea.

Changes of Nasal Airflow Sensitivity in Patients with Chronic Sinusitis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nasal patency may be considered to have two aspects, the resistance to airflow and the sensation of airflow. Although the sensation of nasal airflow has received little attention from clinicians until now, it is likely to be of great importance in clinical practice. However, there are only a few studies that assess the sensation of nasal airflow in patients complaining of nasal obstruction. The aim of this study is to compare the airflow sensitivity of the nose in chronic sinusitis patients with normal controls and to determine the relationship between the airflow sensitivity and the radiologic staging of sinusitis, the presence of polyps, and the status of turbinate mucosa. MATERIALS AND METHOD: All patients had bilateral chronic sinusitis. We assessed the stages of sinusitis by OMU-CT. We also assessed the presence of polyps and the status of inferior and middle turbinate mucosa by endoscopic examination. We measured threshold velocities at five different sites of each nasal cavity by an apparatus delivering a pulsing jet of air at varying velocities. RESULTS: The threshold velocity of nasal airflow at all test sites were higher in sinusitis patients than in normal subjects. There were no significant differences in nasal airflow sensitivity between radiologic staging groups, whereas there were significant correlation between the airflow sensitivity in nasal mucosa and the presence of polyps or status of turbinate mucosa. CONCLUSION: The results suggest that decreased sensation of nasal airflow may contribute to the sensation of nasal obstruction in patients with chronic sinusitis.

Ectopic Thymus: Presenting as a Lateral Neck Mass / 대한이비인후과학회지

Solid ectopic thymus is an extremely uncommon etiology of neck mass in infants. It occurs in the line of descent of the thymus from the angle of the mandible to the superior mediastinum. This paper presents the case of a young female, who presented a lateral neck mass in the right side of her neck. Surgical excision revealed an ectopic thymus. Ectopic thymus tissue maybe an infrequent finding, but it should be included in the differential diagnosis of cases involving neck mass, especially in children. We report the case with a short review of the relative literature.

Effect of ozone on nasal allergic responses in ovalbumin-sensitized rats / 천식및알레르기

Background and objectives: A large body of evidence suggests that ozone plays an important role in the development of respiratory allergy. However, the mechanisms by which ozone may interact with airway responses to allergen are not clear. The aim of this study was to determine whether ozone enhances the nasal inflammatory responses to allergen challenge in ovalbumin-sensitized rats and whether ozone has an effect on the allergic sensitization process. METHOD: Twenty-seven Wistar rats were divided into five groups : control group (group 1), group exposed to 0.3 ppm ozone for 3 days (6 hr/day) (Group 2), group challenged by allergen in ovalbumin-sensitized rats (group 3), group exposed to ozone followed by allergen challenge in ovalbumin-sensitized rats (group 4), and group exposed to 0.3 ppm ozone for 6 hours at intervals of 3 days during allergen sensitization (group 5). To induce the allergic rhinitis in groups 3, 4, and 5, rats were immunized intraperitoneally with ovalbumin-Al(OH)3 gel solution, followed by intranasal nebulization of 0.1% ovalbumin solution. Nasal lavage fluid (NLF) was obtained immediately after the last exposure and then Evans blue dye was infused via the femoral vein. The concentration of protein and total cell counts in NLF and the amount of extravasated Evans blue dye in nasal mucosa were measured. RESULTS: Ozone exposure significantly increased the concentration of protein and total cell counts in NLF and Evans blue extravasation compared to the control group. Allergen challenge in sensitized rats increased total cell counts in NLF and Evans blue extravasation although the differences between this group and the controls did not reach statistical significance. The combination of ozone exposure and allergen challenge caused significant increase in total cell counts in NLF and Evans blue extravasation compared to groups 2 and 3. However, there were no significant differences in Evans blue extravasation, concentrations of protein and total cell counts in NLF between groups 3 and 5. CONCLUSION: Ozone may enhance the nasal inflammatory responses to allergen in patients with allergic rhinitis.