Nuclear receptors mediate allosteric communications where ligand binding initiates a cascade of signal transduction. The interaction of vitamin D with vitamin D receptor (VDR) was investigated by ¹⁹F NMR spectroscopy of the complexes of three fluorinated vitamin D derivatives with the full-length rat VDR-LBD. In the 19F NMR spectra of the VDR-ligand complexes, the A-ring of 4,4-difluoro-1,25(OH)₂D₃ was revealed to adopt β-conformation in the VDR in solution, and the spectra were shown to be dependent on the dissociation constant. While the complex of 4,4-difluoro-1,25(OH)₂D₃ with VDR exhibited a clear distinguishable ¹⁹F NMR spectrum, those of 19F-1,25(OH)₂D₃ stereoisomers, which have 10-fold higher VDR affinity than 4,4-difluoro-1,25(OH)₂D₃, did not. The solid-phase NMR technique was useful for ¹⁹F-1,25(OH)₂D₃ stereoisomers. The fluorinated vitamin D derivatives showed marked changes in the chemical shift (Δ4−19.7 ppm) upon VDRcomplex formation, and the ab initio MO method suggested that van der Waals interactions play a major role in the complex formation

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This study was conducted to characterize the distribution of epithelial regeneration in lungs with diffuse alveolar damage (DAD) and to ascertain whether epithelial regeneration is associated with the underlying disease and/or DAD stage. Methods: Lung specimens obtained at autopsy from 18 patients were studied using p63, PE-10 and Ki-67 immunostaining. The patients were categorized into two groups: patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF; IPF group) and patients without IPF (non-IPF group). Results: p63-positive cells were mostly observed in the alveolar ducts. No significant difference in the appearance of the p63-positive cells was observed between the IPF and non-IPF groups or between the exudative and the proliferative stages. PE-10- positive cells were observed in the alveoli. The number of PE-10-positive cells was significantly higher during the proliferative stage than during the exudative stage. However, p63-positive cells and PE-10-positive cells appeared at day 6 in the earliest case during the exudative stage and Ki- 67-positive cells were observed during the exudative stage. Conclusion: Epithelial regeneration was not associated with the underlying disease. This study revealed that regenerative epithelial cells appeared at day 6 during the exudative stage and that the number of type Ⅱ pneumocytes increased significantly during the proliferative stage.

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Introduction: Endobronchial ultrasound-guided tranbronchial needle aspiration (EBUS-TBNA) can be applied to not only the determination of the clinical stages of lung cancer, but also the diagnosis of lymphadenopathies such as lymphoma and sarcoidosis. Case Report: We report the successful diagnosis of a combined thymic epithelial tumor in a 68-yearold female by EBUS-TBNA. The patient presented with a 6-month history of dysesthesia in bilateral legs. Chest computed tomography revealed a 5.5 cm-tumor with heterogeneous enhancement in the superior and anterior mediastinum. The serum levels of ProGRP and NSE were elevated and anti- Hu antibody was positive at the time of diagnosis. A biopsy by EBUS-TBNA revealed histological evidence of a combined thymic epithelial tumor consisting of small cell neuroendocrine carcinoma and thymic carcinoma. Chemo-radiotherapy reduced the tumor remarkably in size, but the patient’s neurologic symptoms remained. Conclusion: This case suggests that EBUS-TBNA is a safe and useful technique for the diagnosis of paratracheal mediastinal tumors.

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