Broken Tip of a Disposable Saliva Ejector as a Bronchial Foreign Body in a Patient With Severe Physical and Intellectual Disabilities.

Oral care for patients with severe physical and intellectual disabilities is important to prevent the development of systemic diseases and maintain or improve their health. Foreign bodies accidentally aspirated into the respiratory tract can cause critical problems. To our knowledge, this is the first case report of aspiration of a broken tip of a disposable saliva ejector in a patient with severe physical and intellectual disabilities. The patient's strong bite broke off the ejector's tip during oral care. The foreign body was removed by flexible bronchoscopy without any complications. Such cases are sometimes asymptomatic or mildly symptomatic; thus, learning how to appropriately respond is essential for caregivers and family doctors. In addition, this device is widely used in clinical practice, and such risks should be widely known. Moreover, manufacturers should develop more robust equipment for oral care.

Critical response of elastic-plastic SDOF systems with nonlinear viscous damping under simulated earthquake ground motions.

Multi impulse with constant time interval is used as a representative of a long-duration earthquake ground motion. An analytical expression is derived for the elastic-plastic response of a single-degree-of-freedom (SDOF) model with nonlinear viscous damping subjected to the "critical multi impulse" which maximizes the response. The fact that only free vibration appears under such multi impulse enables the smart application of an energy approach in deriving the analytical expression for a complicated elastic-plastic response with nonlinear viscous damping. The nonlinear viscous damping characteristic for deformation is approximated in terms of a quadratic or elliptical function. The critical timing of the impulses is found to correspond to the zero restoring-force timing or the maximum velocity timing depending on the input level. It is shown that the nonlinearity in viscous damping causes a remarkable influence on the earthquake response in some cases. The reliability and accuracy of the proposed theory are investigated through the comparison with the results by the time-history response analysis to the tuned sine wave as a representative of the long-duration earthquake ground motion.

Roles of plasminogen in the alterations in bone marrow hematopoietic stem cells during bone repair.

We previously revealed that stromal cell-derived factor-1 (SDF-1) is involved in the changes in the number of bone marrow stem cells during the bone repair process in mice. Moreover, we reported that plasminogen (Plg) deficiency delays bone repair and the accumulation of macrophages at the site of bone damage in mice. We investigated the roles of Plg in the changes in bone marrow stem cells during bone repair. We analyzed the numbers of hematopoietic stem cells (HSC) and mesenchymal stem cells (MSCs) within bone marrow from Plg-deficient and wild-type mice after a femoral bone injury using flow cytometric analysis. Plg deficiency significantly blunted a decrease in the number of HSCs after bone injury in mice, although it did not affect an increase in the number of MSCs. Plg deficiency significantly blunted the number of SDF-1- and Osterix- or SDF-1- and alkaline phosphatase-double-positive cells in the endosteum around the lesion as well as matrix metalloprotainase-9 (MMP-9) activity and mRNA levels of SDF-1 and transforming growth factor-ß (TGF-ß) elevated by bone injury. TGF-ß signaling inhibition significantly blunted a decrease in the number of HSCs after bone injury. The present study showed that Plg is critical for the changes in bone marrow HSCs through MMP-9, TGF-ß, and SDF-1 at the damaged site during bone repair in mice.