von Willebrand factor D and EGF domains regulate ameloblast differentiation and enamel formation.

Cell- and tissue-specific extracellular matrix (ECM) composition plays an important role in organ development, including teeth, by regulating cell behaviors, such as cell proliferation and differentiation. Here, we demonstrate for the first time that von Willebrand factor D and epidermal growth factor (EGF) domains (Vwde), a previously uncharacterized ECM protein, is specifically expressed in teeth and regulates cell proliferation and differentiation in inner enamel epithelial cells (IEEs) and enamel formation. We identified the Vwde as a novel ECM protein through bioinformatics using the NCBI expressed sequence tag database for mice. Vwde complementary DNA encodes 1773 amino acids containing a signal peptide, a von Willebrand factor type D domain, and tandem calcium-binding EGF-like domains. Real-time polymerase chain reaction demonstrated that Vwde is highly expressed in tooth tissue but not in other tissues including the brain, lung, heart, liver, kidney, and bone. In situ hybridization revealed that the IEEs expressed Vwde messenger RNA in developing teeth. Immunostaining showed that VWDE was localized at the proximal and the distal ends of the pericellular regions of the IEEs. Vwde was induced during the differentiation of mouse dental epithelium-derived M3H1 cells. Vwde-transfected M3H1 cells secreted VWDE protein into the culture medium and inhibited cell proliferation, whereas ameloblastic differentiation was promoted. Furthermore, Vwde increased the phosphorylation of extracellular signal-regulated kinase 1/2 and protein kinase B and strongly induced the expression of the intercellular junction protein, N-cadherin (Ncad). Interestingly, the suppression of endogenous Vwde inhibited the expression of Ncad. Finally, we created Vwde-knockout mice using the CRISPR-Cas9 system. Vwde-null mice showed low mineral density, rough surface, and cracks in the enamel, indicating the enamel hypoplasia phenotype. Our findings suggest that Vwde assembling the matrix underneath the IEEs is essential for Ncad expression and enamel formation.

Effects of Nutritional Treatment on the Frequency of Pneumonia in Bedridden Patients Receiving Oral Care.

Objective Pneumonia develops in bedridden patients, even in those receiving oral care, and malnutrition is associated with the development of pneumonia. We examined the effects of nutritional treatment on the prevention of pneumonia. Patients and Methods We retrospectively examined the effects of nutritional treatment on the prevention of pneumonia by analyzing the records of bedridden patients (n=68; mean age: 68.0 years) who stayed in a hospital for 2 years or longer. Results Among the analyzed patients, pneumonia developed in 52 (76%) patients, and the mean frequency of pneumonia was 1.6 times per year during the first year of stay. In a multivariate analysis, the serum albumin level at admission in the pneumonia group was lower than that in the non-pneumonia group. The frequency of pneumonia during the second year of stay was lower than that during the first year of stay. Serum levels of albumin and total protein (TP) at one year after admission were higher than those at admission in all analyzed patients, and in all patients (n=52) and elderly (≥65 years) patients (n=31) in the pneumonia group. The proportions of patients with hypoalbuminemia (<3.5 g/dL) and hypoproteinemia (<6.5 g/dL) at one year after admission were lower than those at admission. The increases in the proportions of patients presenting a reduced frequency of pneumonia were correlated with increases in the proportions of patients presenting increased levels of albumin and/or TP. Conclusion Nutritional treatment may reduce the frequency of pneumonia by improving malnutrition in bedridden patients receiving oral care.

Thiamylal antagonizes the inhibitory effects of dorsal column stimulation on dorsal horn activities in humans.

In humans, peripheral somatosensory information converges upon dorsal horn neurons in the spinal cord, which can be recorded from the dorsal epidural space as spinal cord potentials (SCPs) following segmental dorsal root stimulation (SS) employing epidural catheter electrodes. Antidromic action potentials and descending inhibition from the dorsolateral funiculus may contribute to SCPs following dorsal column stimulation (DCS). Effects of thiamylal (2.5-7.5 mg/kg, i.v.) on SCPs evoked by independent DCS or SS were compared with those evoked by simultaneous DCS and SS (DCS/SS). DCS- and SS-evoked SCPs recorded from the lumbar enlargement consisted of a sharp negative (N) followed by a slow positive (P) potential. Thiamylal induced dose-dependent increases in amplitude and duration of both N and P potentials evoked by DCS and SS, whether the responses were summed or evoked simultaneously. In awake subjects, N and P potentials produced by simultaneous DCS/SS were significantly smaller than the sum of independent responses. Thiamylal anesthesia antagonized this inhibition; responses to simultaneous DCS/SS were larger than the sum of independent responses. These results suggest that in wakefulness DCS inhibits dorsal horn neuron activity in the lumbar spinal cord, while thiamylal antagonizes DCS-induced inhibition in dose-dependent fashion.