This report describes our initial attempt to regenerate salivary glands using induced pluripotent stem (iPS) cells in vivo and in vitro. Glandular tissues that were similar to the adult submandibular glands (SMGs) and sublingual glands could be partially produced by the transplantation of iPS cells into mouse salivary glands. However, the tumorigenicity of iPS cells has not been resolved yet. It is well known that stem cells affect their microenvironment, known as a stem cell niche. We focused on the niche and the interaction between iPS cells and salivary gland cells in our study on salivary gland regeneration. Coculture of embryonic SMG cells and iPS cells have better-developed epithelial structures and fewer undifferentiated specific markers than monoculture of embryonic SMG cells in vitro. These results suggest that iPS cells have a potential ability to accelerate differentiation for salivary gland development and regeneration.

Background Aspiration pneumonia is a major complication that occurs in patients with severe cerebral palsy and is associated with their survival prognosis, necessitating appropriate assessment and response. We focused on swallowing frequency as an index of daily swallowing function due to the difficulty in evaluating the risk of pneumonia. The swallowing motion protects the airway by safely directing the food, saliva, and secretions accumulated in the pharynx into the esophagus to prevent aspiration and entry into the trachea. Thus, swallowing frequency may be correlated with the incidence of pneumonia. In this study, we aimed to investigate the relationship between swallowing frequency and history of pneumonia in patients with severe cerebral palsy. Methods Fifty-seven patients with cerebral palsy were included in this study. Swallowing frequency was measured three times for each patient on separate days, and the reproducibility was examined by calculating the intraclass correlation coefficient. Further, the relationship between swallowing frequency and history of pneumonia was investigated using multivariate logistic regression analysis. Results While swallowing frequency differed between participants, it was constant within individuals (intraclass correlation coefficient: 0.941). Furthermore, the swallowing frequencies per hour were 12.2 ± 12.2 and 27.0 ± 20.4 in the patient groups with and without a history of pneumonia, respectively (P < 0.001). Swallowing frequency (odds ratio: 10.489, 95% confidence interval: 2.706–40.663, P = 0.001) was significantly associated with the incidence of pneumonia in the previous year. Conclusions Swallowing frequency could be used as an index for assessing the risk of dysphagia and pneumonia in patients with severe cerebral palsy.

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Background: Patients with cerebral palsy are known to have reduced swallowing function because of various causes. Aspiration pneumonia resulting from decreased swallowing function is a major complication in patients with severe cerebral palsy and is directly associated with their survival prognosis. This necessitates an appropriate assessment and response to the aforementioned risk. Previous reports on cerebral palsy patients have mentioned large differences in the prevalence of aspiration, when assessed with standard swallowing function tests. Moreover, there is a weak association between aspiration detected by swallowing function tests, such as video endoscopy and video fluoroscopy, and the incidence of pneumonia. Considering the difficulty in evaluating the risk of pneumonia, we focused on swallowing frequency as an index of daily swallowing function. Swallowing motion protects the airway by safely directing the food, saliva, and secretions accumulated in the pharynx into the esophagus to prevent aspiration and entry into the trachea. Thus, swallowing frequency during daily life can be considered an index for evaluating the risk of regular aspiration and pneumonia. In this retrospective study, we investigated the relationship between swallowing frequency and pneumonia in patients with severe cerebral palsy. Methods: Fifty seven cerebral palsy patients were included in this study. The swallowing frequency was measured three times for each patient on separate days, and the reproducibility was examined by calculating the intraclass correlation coefficient. Further, the relationship between swallowing frequency and history of pneumonia was investigated by multivariate logistic regression analysis.Results: While the swallowing frequency differed between participants, it was constant within individuals (intraclass correlation coefficient: 0.941). Furthermore, the swallowing frequencies per hour were 12.2 ± 12.2 and 27.0 ± 20.4 in the patient groups with and without a history of pneumonia, respectively (P<0.001). Swallowing frequency (odds ratio: 10.489, 95% confidence interval: 2.706–40.663, P=0.001) was significantly associated with the incidence of pneumonia in the previous year.Conclusions: Swallowing frequency could be used as an index for assessing the risk of dysphagia and pneumonia in patients with severe cerebral palsy.